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c561d110 | 1 | // SPDX-License-Identifier: GPL-2.0 |
69b693f0 MKL |
2 | /* Copyright (c) 2018 Facebook */ |
3 | ||
4 | #include <uapi/linux/btf.h> | |
91cc1a99 AS |
5 | #include <uapi/linux/bpf.h> |
6 | #include <uapi/linux/bpf_perf_event.h> | |
69b693f0 | 7 | #include <uapi/linux/types.h> |
b00b8dae | 8 | #include <linux/seq_file.h> |
69b693f0 | 9 | #include <linux/compiler.h> |
2667a262 | 10 | #include <linux/ctype.h> |
69b693f0 MKL |
11 | #include <linux/errno.h> |
12 | #include <linux/slab.h> | |
f56a653c MKL |
13 | #include <linux/anon_inodes.h> |
14 | #include <linux/file.h> | |
69b693f0 MKL |
15 | #include <linux/uaccess.h> |
16 | #include <linux/kernel.h> | |
78958fca | 17 | #include <linux/idr.h> |
f80442a4 | 18 | #include <linux/sort.h> |
69b693f0 MKL |
19 | #include <linux/bpf_verifier.h> |
20 | #include <linux/btf.h> | |
49f4e672 | 21 | #include <linux/btf_ids.h> |
c0c852dd | 22 | #include <linux/bpf_lsm.h> |
91cc1a99 AS |
23 | #include <linux/skmsg.h> |
24 | #include <linux/perf_event.h> | |
eae2e83e | 25 | #include <linux/bsearch.h> |
36e68442 AN |
26 | #include <linux/kobject.h> |
27 | #include <linux/sysfs.h> | |
fd9c663b FW |
28 | |
29 | #include <net/netfilter/nf_bpf_link.h> | |
30 | ||
91cc1a99 | 31 | #include <net/sock.h> |
680ee045 | 32 | #include <net/xdp.h> |
1e89106d | 33 | #include "../tools/lib/bpf/relo_core.h" |
69b693f0 MKL |
34 | |
35 | /* BTF (BPF Type Format) is the meta data format which describes | |
36 | * the data types of BPF program/map. Hence, it basically focus | |
37 | * on the C programming language which the modern BPF is primary | |
38 | * using. | |
39 | * | |
40 | * ELF Section: | |
41 | * ~~~~~~~~~~~ | |
42 | * The BTF data is stored under the ".BTF" ELF section | |
43 | * | |
44 | * struct btf_type: | |
45 | * ~~~~~~~~~~~~~~~ | |
46 | * Each 'struct btf_type' object describes a C data type. | |
47 | * Depending on the type it is describing, a 'struct btf_type' | |
48 | * object may be followed by more data. F.e. | |
49 | * To describe an array, 'struct btf_type' is followed by | |
50 | * 'struct btf_array'. | |
51 | * | |
52 | * 'struct btf_type' and any extra data following it are | |
53 | * 4 bytes aligned. | |
54 | * | |
55 | * Type section: | |
56 | * ~~~~~~~~~~~~~ | |
57 | * The BTF type section contains a list of 'struct btf_type' objects. | |
58 | * Each one describes a C type. Recall from the above section | |
59 | * that a 'struct btf_type' object could be immediately followed by extra | |
8fb33b60 | 60 | * data in order to describe some particular C types. |
69b693f0 MKL |
61 | * |
62 | * type_id: | |
63 | * ~~~~~~~ | |
64 | * Each btf_type object is identified by a type_id. The type_id | |
65 | * is implicitly implied by the location of the btf_type object in | |
66 | * the BTF type section. The first one has type_id 1. The second | |
67 | * one has type_id 2...etc. Hence, an earlier btf_type has | |
68 | * a smaller type_id. | |
69 | * | |
70 | * A btf_type object may refer to another btf_type object by using | |
71 | * type_id (i.e. the "type" in the "struct btf_type"). | |
72 | * | |
73 | * NOTE that we cannot assume any reference-order. | |
74 | * A btf_type object can refer to an earlier btf_type object | |
75 | * but it can also refer to a later btf_type object. | |
76 | * | |
77 | * For example, to describe "const void *". A btf_type | |
78 | * object describing "const" may refer to another btf_type | |
79 | * object describing "void *". This type-reference is done | |
80 | * by specifying type_id: | |
81 | * | |
82 | * [1] CONST (anon) type_id=2 | |
83 | * [2] PTR (anon) type_id=0 | |
84 | * | |
85 | * The above is the btf_verifier debug log: | |
86 | * - Each line started with "[?]" is a btf_type object | |
87 | * - [?] is the type_id of the btf_type object. | |
88 | * - CONST/PTR is the BTF_KIND_XXX | |
89 | * - "(anon)" is the name of the type. It just | |
90 | * happens that CONST and PTR has no name. | |
91 | * - type_id=XXX is the 'u32 type' in btf_type | |
92 | * | |
93 | * NOTE: "void" has type_id 0 | |
94 | * | |
95 | * String section: | |
96 | * ~~~~~~~~~~~~~~ | |
97 | * The BTF string section contains the names used by the type section. | |
98 | * Each string is referred by an "offset" from the beginning of the | |
99 | * string section. | |
100 | * | |
101 | * Each string is '\0' terminated. | |
102 | * | |
103 | * The first character in the string section must be '\0' | |
104 | * which is used to mean 'anonymous'. Some btf_type may not | |
105 | * have a name. | |
106 | */ | |
107 | ||
108 | /* BTF verification: | |
109 | * | |
110 | * To verify BTF data, two passes are needed. | |
111 | * | |
112 | * Pass #1 | |
113 | * ~~~~~~~ | |
114 | * The first pass is to collect all btf_type objects to | |
115 | * an array: "btf->types". | |
116 | * | |
117 | * Depending on the C type that a btf_type is describing, | |
118 | * a btf_type may be followed by extra data. We don't know | |
119 | * how many btf_type is there, and more importantly we don't | |
120 | * know where each btf_type is located in the type section. | |
121 | * | |
122 | * Without knowing the location of each type_id, most verifications | |
123 | * cannot be done. e.g. an earlier btf_type may refer to a later | |
124 | * btf_type (recall the "const void *" above), so we cannot | |
125 | * check this type-reference in the first pass. | |
126 | * | |
127 | * In the first pass, it still does some verifications (e.g. | |
128 | * checking the name is a valid offset to the string section). | |
eb3f595d MKL |
129 | * |
130 | * Pass #2 | |
131 | * ~~~~~~~ | |
132 | * The main focus is to resolve a btf_type that is referring | |
133 | * to another type. | |
134 | * | |
135 | * We have to ensure the referring type: | |
136 | * 1) does exist in the BTF (i.e. in btf->types[]) | |
137 | * 2) does not cause a loop: | |
138 | * struct A { | |
139 | * struct B b; | |
140 | * }; | |
141 | * | |
142 | * struct B { | |
143 | * struct A a; | |
144 | * }; | |
145 | * | |
146 | * btf_type_needs_resolve() decides if a btf_type needs | |
147 | * to be resolved. | |
148 | * | |
149 | * The needs_resolve type implements the "resolve()" ops which | |
150 | * essentially does a DFS and detects backedge. | |
151 | * | |
152 | * During resolve (or DFS), different C types have different | |
153 | * "RESOLVED" conditions. | |
154 | * | |
155 | * When resolving a BTF_KIND_STRUCT, we need to resolve all its | |
156 | * members because a member is always referring to another | |
157 | * type. A struct's member can be treated as "RESOLVED" if | |
158 | * it is referring to a BTF_KIND_PTR. Otherwise, the | |
159 | * following valid C struct would be rejected: | |
160 | * | |
161 | * struct A { | |
162 | * int m; | |
163 | * struct A *a; | |
164 | * }; | |
165 | * | |
166 | * When resolving a BTF_KIND_PTR, it needs to keep resolving if | |
167 | * it is referring to another BTF_KIND_PTR. Otherwise, we cannot | |
168 | * detect a pointer loop, e.g.: | |
169 | * BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR + | |
170 | * ^ | | |
171 | * +-----------------------------------------+ | |
172 | * | |
69b693f0 MKL |
173 | */ |
174 | ||
b1e8818c | 175 | #define BITS_PER_U128 (sizeof(u64) * BITS_PER_BYTE * 2) |
69b693f0 MKL |
176 | #define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1) |
177 | #define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK) | |
178 | #define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3) | |
179 | #define BITS_ROUNDUP_BYTES(bits) \ | |
180 | (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits)) | |
181 | ||
b1828f0b | 182 | #define BTF_INFO_MASK 0x9f00ffff |
aea2f7b8 MKL |
183 | #define BTF_INT_MASK 0x0fffffff |
184 | #define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE) | |
185 | #define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET) | |
186 | ||
69b693f0 MKL |
187 | /* 16MB for 64k structs and each has 16 members and |
188 | * a few MB spaces for the string section. | |
189 | * The hard limit is S32_MAX. | |
190 | */ | |
191 | #define BTF_MAX_SIZE (16 * 1024 * 1024) | |
69b693f0 | 192 | |
eb3f595d MKL |
193 | #define for_each_member_from(i, from, struct_type, member) \ |
194 | for (i = from, member = btf_type_member(struct_type) + from; \ | |
195 | i < btf_type_vlen(struct_type); \ | |
196 | i++, member++) | |
197 | ||
1dc92851 DB |
198 | #define for_each_vsi_from(i, from, struct_type, member) \ |
199 | for (i = from, member = btf_type_var_secinfo(struct_type) + from; \ | |
200 | i < btf_type_vlen(struct_type); \ | |
201 | i++, member++) | |
202 | ||
1b9ed84e QM |
203 | DEFINE_IDR(btf_idr); |
204 | DEFINE_SPINLOCK(btf_idr_lock); | |
78958fca | 205 | |
dee872e1 | 206 | enum btf_kfunc_hook { |
cfe14564 | 207 | BTF_KFUNC_HOOK_COMMON, |
dee872e1 KKD |
208 | BTF_KFUNC_HOOK_XDP, |
209 | BTF_KFUNC_HOOK_TC, | |
210 | BTF_KFUNC_HOOK_STRUCT_OPS, | |
97949767 BT |
211 | BTF_KFUNC_HOOK_TRACING, |
212 | BTF_KFUNC_HOOK_SYSCALL, | |
5b481aca | 213 | BTF_KFUNC_HOOK_FMODRET, |
b5964b96 JK |
214 | BTF_KFUNC_HOOK_CGROUP_SKB, |
215 | BTF_KFUNC_HOOK_SCHED_ACT, | |
216 | BTF_KFUNC_HOOK_SK_SKB, | |
217 | BTF_KFUNC_HOOK_SOCKET_FILTER, | |
218 | BTF_KFUNC_HOOK_LWT, | |
fd9c663b | 219 | BTF_KFUNC_HOOK_NETFILTER, |
dee872e1 KKD |
220 | BTF_KFUNC_HOOK_MAX, |
221 | }; | |
222 | ||
223 | enum { | |
f9b34818 | 224 | BTF_KFUNC_SET_MAX_CNT = 256, |
5ce937d6 | 225 | BTF_DTOR_KFUNC_MAX_CNT = 256, |
e924e80e AG |
226 | BTF_KFUNC_FILTER_MAX_CNT = 16, |
227 | }; | |
228 | ||
229 | struct btf_kfunc_hook_filter { | |
230 | btf_kfunc_filter_t filters[BTF_KFUNC_FILTER_MAX_CNT]; | |
231 | u32 nr_filters; | |
dee872e1 KKD |
232 | }; |
233 | ||
234 | struct btf_kfunc_set_tab { | |
a4703e31 | 235 | struct btf_id_set8 *sets[BTF_KFUNC_HOOK_MAX]; |
e924e80e | 236 | struct btf_kfunc_hook_filter hook_filters[BTF_KFUNC_HOOK_MAX]; |
dee872e1 KKD |
237 | }; |
238 | ||
5ce937d6 KKD |
239 | struct btf_id_dtor_kfunc_tab { |
240 | u32 cnt; | |
241 | struct btf_id_dtor_kfunc dtors[]; | |
242 | }; | |
243 | ||
69b693f0 | 244 | struct btf { |
f80442a4 | 245 | void *data; |
69b693f0 | 246 | struct btf_type **types; |
eb3f595d MKL |
247 | u32 *resolved_ids; |
248 | u32 *resolved_sizes; | |
69b693f0 MKL |
249 | const char *strings; |
250 | void *nohdr_data; | |
f80442a4 | 251 | struct btf_header hdr; |
951bb646 | 252 | u32 nr_types; /* includes VOID for base BTF */ |
69b693f0 MKL |
253 | u32 types_size; |
254 | u32 data_size; | |
f56a653c | 255 | refcount_t refcnt; |
78958fca MKL |
256 | u32 id; |
257 | struct rcu_head rcu; | |
dee872e1 | 258 | struct btf_kfunc_set_tab *kfunc_set_tab; |
5ce937d6 | 259 | struct btf_id_dtor_kfunc_tab *dtor_kfunc_tab; |
8ffa5cc1 | 260 | struct btf_struct_metas *struct_meta_tab; |
951bb646 AN |
261 | |
262 | /* split BTF support */ | |
263 | struct btf *base_btf; | |
264 | u32 start_id; /* first type ID in this BTF (0 for base BTF) */ | |
265 | u32 start_str_off; /* first string offset (0 for base BTF) */ | |
53297220 AN |
266 | char name[MODULE_NAME_LEN]; |
267 | bool kernel_btf; | |
69b693f0 MKL |
268 | }; |
269 | ||
eb3f595d MKL |
270 | enum verifier_phase { |
271 | CHECK_META, | |
272 | CHECK_TYPE, | |
273 | }; | |
274 | ||
275 | struct resolve_vertex { | |
276 | const struct btf_type *t; | |
277 | u32 type_id; | |
278 | u16 next_member; | |
279 | }; | |
280 | ||
281 | enum visit_state { | |
282 | NOT_VISITED, | |
283 | VISITED, | |
284 | RESOLVED, | |
285 | }; | |
286 | ||
287 | enum resolve_mode { | |
288 | RESOLVE_TBD, /* To Be Determined */ | |
289 | RESOLVE_PTR, /* Resolving for Pointer */ | |
290 | RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union | |
291 | * or array | |
292 | */ | |
293 | }; | |
294 | ||
295 | #define MAX_RESOLVE_DEPTH 32 | |
296 | ||
f80442a4 MKL |
297 | struct btf_sec_info { |
298 | u32 off; | |
299 | u32 len; | |
300 | }; | |
301 | ||
69b693f0 MKL |
302 | struct btf_verifier_env { |
303 | struct btf *btf; | |
eb3f595d MKL |
304 | u8 *visit_states; |
305 | struct resolve_vertex stack[MAX_RESOLVE_DEPTH]; | |
69b693f0 MKL |
306 | struct bpf_verifier_log log; |
307 | u32 log_type_id; | |
eb3f595d MKL |
308 | u32 top_stack; |
309 | enum verifier_phase phase; | |
310 | enum resolve_mode resolve_mode; | |
69b693f0 MKL |
311 | }; |
312 | ||
313 | static const char * const btf_kind_str[NR_BTF_KINDS] = { | |
314 | [BTF_KIND_UNKN] = "UNKNOWN", | |
315 | [BTF_KIND_INT] = "INT", | |
316 | [BTF_KIND_PTR] = "PTR", | |
317 | [BTF_KIND_ARRAY] = "ARRAY", | |
318 | [BTF_KIND_STRUCT] = "STRUCT", | |
319 | [BTF_KIND_UNION] = "UNION", | |
320 | [BTF_KIND_ENUM] = "ENUM", | |
321 | [BTF_KIND_FWD] = "FWD", | |
322 | [BTF_KIND_TYPEDEF] = "TYPEDEF", | |
323 | [BTF_KIND_VOLATILE] = "VOLATILE", | |
324 | [BTF_KIND_CONST] = "CONST", | |
325 | [BTF_KIND_RESTRICT] = "RESTRICT", | |
2667a262 MKL |
326 | [BTF_KIND_FUNC] = "FUNC", |
327 | [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO", | |
1dc92851 DB |
328 | [BTF_KIND_VAR] = "VAR", |
329 | [BTF_KIND_DATASEC] = "DATASEC", | |
b1828f0b | 330 | [BTF_KIND_FLOAT] = "FLOAT", |
223f903e | 331 | [BTF_KIND_DECL_TAG] = "DECL_TAG", |
8c42d2fa | 332 | [BTF_KIND_TYPE_TAG] = "TYPE_TAG", |
6089fb32 | 333 | [BTF_KIND_ENUM64] = "ENUM64", |
69b693f0 MKL |
334 | }; |
335 | ||
e6ac2450 | 336 | const char *btf_type_str(const struct btf_type *t) |
be8704ff AS |
337 | { |
338 | return btf_kind_str[BTF_INFO_KIND(t->info)]; | |
339 | } | |
340 | ||
31d0bc81 AM |
341 | /* Chunk size we use in safe copy of data to be shown. */ |
342 | #define BTF_SHOW_OBJ_SAFE_SIZE 32 | |
343 | ||
344 | /* | |
345 | * This is the maximum size of a base type value (equivalent to a | |
346 | * 128-bit int); if we are at the end of our safe buffer and have | |
347 | * less than 16 bytes space we can't be assured of being able | |
348 | * to copy the next type safely, so in such cases we will initiate | |
349 | * a new copy. | |
350 | */ | |
351 | #define BTF_SHOW_OBJ_BASE_TYPE_SIZE 16 | |
352 | ||
353 | /* Type name size */ | |
354 | #define BTF_SHOW_NAME_SIZE 80 | |
355 | ||
b613d335 DV |
356 | /* |
357 | * The suffix of a type that indicates it cannot alias another type when | |
358 | * comparing BTF IDs for kfunc invocations. | |
359 | */ | |
360 | #define NOCAST_ALIAS_SUFFIX "___init" | |
361 | ||
31d0bc81 AM |
362 | /* |
363 | * Common data to all BTF show operations. Private show functions can add | |
364 | * their own data to a structure containing a struct btf_show and consult it | |
365 | * in the show callback. See btf_type_show() below. | |
366 | * | |
367 | * One challenge with showing nested data is we want to skip 0-valued | |
368 | * data, but in order to figure out whether a nested object is all zeros | |
369 | * we need to walk through it. As a result, we need to make two passes | |
370 | * when handling structs, unions and arrays; the first path simply looks | |
371 | * for nonzero data, while the second actually does the display. The first | |
372 | * pass is signalled by show->state.depth_check being set, and if we | |
373 | * encounter a non-zero value we set show->state.depth_to_show to | |
374 | * the depth at which we encountered it. When we have completed the | |
375 | * first pass, we will know if anything needs to be displayed if | |
376 | * depth_to_show > depth. See btf_[struct,array]_show() for the | |
377 | * implementation of this. | |
378 | * | |
379 | * Another problem is we want to ensure the data for display is safe to | |
380 | * access. To support this, the anonymous "struct {} obj" tracks the data | |
381 | * object and our safe copy of it. We copy portions of the data needed | |
382 | * to the object "copy" buffer, but because its size is limited to | |
383 | * BTF_SHOW_OBJ_COPY_LEN bytes, multiple copies may be required as we | |
384 | * traverse larger objects for display. | |
385 | * | |
386 | * The various data type show functions all start with a call to | |
387 | * btf_show_start_type() which returns a pointer to the safe copy | |
388 | * of the data needed (or if BTF_SHOW_UNSAFE is specified, to the | |
389 | * raw data itself). btf_show_obj_safe() is responsible for | |
390 | * using copy_from_kernel_nofault() to update the safe data if necessary | |
391 | * as we traverse the object's data. skbuff-like semantics are | |
392 | * used: | |
393 | * | |
394 | * - obj.head points to the start of the toplevel object for display | |
395 | * - obj.size is the size of the toplevel object | |
396 | * - obj.data points to the current point in the original data at | |
397 | * which our safe data starts. obj.data will advance as we copy | |
398 | * portions of the data. | |
399 | * | |
400 | * In most cases a single copy will suffice, but larger data structures | |
401 | * such as "struct task_struct" will require many copies. The logic in | |
402 | * btf_show_obj_safe() handles the logic that determines if a new | |
403 | * copy_from_kernel_nofault() is needed. | |
404 | */ | |
405 | struct btf_show { | |
406 | u64 flags; | |
407 | void *target; /* target of show operation (seq file, buffer) */ | |
408 | void (*showfn)(struct btf_show *show, const char *fmt, va_list args); | |
409 | const struct btf *btf; | |
410 | /* below are used during iteration */ | |
411 | struct { | |
412 | u8 depth; | |
413 | u8 depth_to_show; | |
414 | u8 depth_check; | |
415 | u8 array_member:1, | |
416 | array_terminated:1; | |
417 | u16 array_encoding; | |
418 | u32 type_id; | |
419 | int status; /* non-zero for error */ | |
420 | const struct btf_type *type; | |
421 | const struct btf_member *member; | |
422 | char name[BTF_SHOW_NAME_SIZE]; /* space for member name/type */ | |
423 | } state; | |
424 | struct { | |
425 | u32 size; | |
426 | void *head; | |
427 | void *data; | |
428 | u8 safe[BTF_SHOW_OBJ_SAFE_SIZE]; | |
429 | } obj; | |
430 | }; | |
431 | ||
69b693f0 MKL |
432 | struct btf_kind_operations { |
433 | s32 (*check_meta)(struct btf_verifier_env *env, | |
434 | const struct btf_type *t, | |
435 | u32 meta_left); | |
eb3f595d MKL |
436 | int (*resolve)(struct btf_verifier_env *env, |
437 | const struct resolve_vertex *v); | |
179cde8c MKL |
438 | int (*check_member)(struct btf_verifier_env *env, |
439 | const struct btf_type *struct_type, | |
440 | const struct btf_member *member, | |
441 | const struct btf_type *member_type); | |
9d5f9f70 YS |
442 | int (*check_kflag_member)(struct btf_verifier_env *env, |
443 | const struct btf_type *struct_type, | |
444 | const struct btf_member *member, | |
445 | const struct btf_type *member_type); | |
69b693f0 MKL |
446 | void (*log_details)(struct btf_verifier_env *env, |
447 | const struct btf_type *t); | |
31d0bc81 | 448 | void (*show)(const struct btf *btf, const struct btf_type *t, |
b00b8dae | 449 | u32 type_id, void *data, u8 bits_offsets, |
31d0bc81 | 450 | struct btf_show *show); |
69b693f0 MKL |
451 | }; |
452 | ||
453 | static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS]; | |
454 | static struct btf_type btf_void; | |
455 | ||
2667a262 MKL |
456 | static int btf_resolve(struct btf_verifier_env *env, |
457 | const struct btf_type *t, u32 type_id); | |
458 | ||
d7e7b42f YS |
459 | static int btf_func_check(struct btf_verifier_env *env, |
460 | const struct btf_type *t); | |
461 | ||
eb3f595d MKL |
462 | static bool btf_type_is_modifier(const struct btf_type *t) |
463 | { | |
464 | /* Some of them is not strictly a C modifier | |
465 | * but they are grouped into the same bucket | |
466 | * for BTF concern: | |
467 | * A type (t) that refers to another | |
468 | * type through t->type AND its size cannot | |
469 | * be determined without following the t->type. | |
470 | * | |
471 | * ptr does not fall into this bucket | |
472 | * because its size is always sizeof(void *). | |
473 | */ | |
474 | switch (BTF_INFO_KIND(t->info)) { | |
475 | case BTF_KIND_TYPEDEF: | |
476 | case BTF_KIND_VOLATILE: | |
477 | case BTF_KIND_CONST: | |
478 | case BTF_KIND_RESTRICT: | |
8c42d2fa | 479 | case BTF_KIND_TYPE_TAG: |
eb3f595d MKL |
480 | return true; |
481 | } | |
482 | ||
483 | return false; | |
484 | } | |
485 | ||
2824ecb7 | 486 | bool btf_type_is_void(const struct btf_type *t) |
eb3f595d | 487 | { |
b47a0bd2 MKL |
488 | return t == &btf_void; |
489 | } | |
490 | ||
491 | static bool btf_type_is_fwd(const struct btf_type *t) | |
492 | { | |
493 | return BTF_INFO_KIND(t->info) == BTF_KIND_FWD; | |
494 | } | |
495 | ||
e6c2f594 | 496 | static bool btf_type_is_datasec(const struct btf_type *t) |
b47a0bd2 | 497 | { |
e6c2f594 | 498 | return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC; |
eb3f595d MKL |
499 | } |
500 | ||
e6c2f594 | 501 | static bool btf_type_is_decl_tag(const struct btf_type *t) |
eb3f595d | 502 | { |
e6c2f594 | 503 | return BTF_INFO_KIND(t->info) == BTF_KIND_DECL_TAG; |
eb3f595d MKL |
504 | } |
505 | ||
e6c2f594 | 506 | static bool btf_type_nosize(const struct btf_type *t) |
1dc92851 | 507 | { |
e6c2f594 YS |
508 | return btf_type_is_void(t) || btf_type_is_fwd(t) || |
509 | btf_type_is_func(t) || btf_type_is_func_proto(t) || | |
510 | btf_type_is_decl_tag(t); | |
1dc92851 DB |
511 | } |
512 | ||
e6c2f594 | 513 | static bool btf_type_nosize_or_null(const struct btf_type *t) |
b5ea834d | 514 | { |
e6c2f594 | 515 | return !t || btf_type_nosize(t); |
b5ea834d YS |
516 | } |
517 | ||
223f903e | 518 | static bool btf_type_is_decl_tag_target(const struct btf_type *t) |
b5ea834d YS |
519 | { |
520 | return btf_type_is_func(t) || btf_type_is_struct(t) || | |
bd16dee6 | 521 | btf_type_is_var(t) || btf_type_is_typedef(t); |
b5ea834d YS |
522 | } |
523 | ||
541c3bad | 524 | u32 btf_nr_types(const struct btf *btf) |
951bb646 AN |
525 | { |
526 | u32 total = 0; | |
527 | ||
528 | while (btf) { | |
529 | total += btf->nr_types; | |
530 | btf = btf->base_btf; | |
531 | } | |
532 | ||
533 | return total; | |
534 | } | |
535 | ||
27ae7997 MKL |
536 | s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind) |
537 | { | |
538 | const struct btf_type *t; | |
539 | const char *tname; | |
951bb646 | 540 | u32 i, total; |
27ae7997 | 541 | |
541c3bad | 542 | total = btf_nr_types(btf); |
951bb646 AN |
543 | for (i = 1; i < total; i++) { |
544 | t = btf_type_by_id(btf, i); | |
27ae7997 MKL |
545 | if (BTF_INFO_KIND(t->info) != kind) |
546 | continue; | |
547 | ||
548 | tname = btf_name_by_offset(btf, t->name_off); | |
549 | if (!strcmp(tname, name)) | |
550 | return i; | |
551 | } | |
552 | ||
553 | return -ENOENT; | |
554 | } | |
555 | ||
b1d1e904 | 556 | s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p) |
edc3ec09 KKD |
557 | { |
558 | struct btf *btf; | |
559 | s32 ret; | |
560 | int id; | |
561 | ||
562 | btf = bpf_get_btf_vmlinux(); | |
563 | if (IS_ERR(btf)) | |
564 | return PTR_ERR(btf); | |
7ada3787 KKD |
565 | if (!btf) |
566 | return -EINVAL; | |
edc3ec09 KKD |
567 | |
568 | ret = btf_find_by_name_kind(btf, name, kind); | |
569 | /* ret is never zero, since btf_find_by_name_kind returns | |
570 | * positive btf_id or negative error. | |
571 | */ | |
572 | if (ret > 0) { | |
573 | btf_get(btf); | |
574 | *btf_p = btf; | |
575 | return ret; | |
576 | } | |
577 | ||
578 | /* If name is not found in vmlinux's BTF then search in module's BTFs */ | |
579 | spin_lock_bh(&btf_idr_lock); | |
580 | idr_for_each_entry(&btf_idr, btf, id) { | |
581 | if (!btf_is_module(btf)) | |
582 | continue; | |
583 | /* linear search could be slow hence unlock/lock | |
584 | * the IDR to avoiding holding it for too long | |
585 | */ | |
586 | btf_get(btf); | |
587 | spin_unlock_bh(&btf_idr_lock); | |
588 | ret = btf_find_by_name_kind(btf, name, kind); | |
589 | if (ret > 0) { | |
590 | *btf_p = btf; | |
591 | return ret; | |
592 | } | |
edc3ec09 | 593 | btf_put(btf); |
acf1c3d6 | 594 | spin_lock_bh(&btf_idr_lock); |
edc3ec09 KKD |
595 | } |
596 | spin_unlock_bh(&btf_idr_lock); | |
597 | return ret; | |
598 | } | |
599 | ||
27ae7997 MKL |
600 | const struct btf_type *btf_type_skip_modifiers(const struct btf *btf, |
601 | u32 id, u32 *res_id) | |
602 | { | |
603 | const struct btf_type *t = btf_type_by_id(btf, id); | |
604 | ||
605 | while (btf_type_is_modifier(t)) { | |
606 | id = t->type; | |
607 | t = btf_type_by_id(btf, t->type); | |
608 | } | |
609 | ||
610 | if (res_id) | |
611 | *res_id = id; | |
612 | ||
613 | return t; | |
614 | } | |
615 | ||
616 | const struct btf_type *btf_type_resolve_ptr(const struct btf *btf, | |
617 | u32 id, u32 *res_id) | |
618 | { | |
619 | const struct btf_type *t; | |
620 | ||
621 | t = btf_type_skip_modifiers(btf, id, NULL); | |
622 | if (!btf_type_is_ptr(t)) | |
623 | return NULL; | |
624 | ||
625 | return btf_type_skip_modifiers(btf, t->type, res_id); | |
626 | } | |
627 | ||
628 | const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf, | |
629 | u32 id, u32 *res_id) | |
630 | { | |
631 | const struct btf_type *ptype; | |
632 | ||
633 | ptype = btf_type_resolve_ptr(btf, id, res_id); | |
634 | if (ptype && btf_type_is_func_proto(ptype)) | |
635 | return ptype; | |
636 | ||
637 | return NULL; | |
638 | } | |
639 | ||
1dc92851 DB |
640 | /* Types that act only as a source, not sink or intermediate |
641 | * type when resolving. | |
642 | */ | |
643 | static bool btf_type_is_resolve_source_only(const struct btf_type *t) | |
644 | { | |
645 | return btf_type_is_var(t) || | |
223f903e | 646 | btf_type_is_decl_tag(t) || |
1dc92851 DB |
647 | btf_type_is_datasec(t); |
648 | } | |
649 | ||
eb3f595d MKL |
650 | /* What types need to be resolved? |
651 | * | |
652 | * btf_type_is_modifier() is an obvious one. | |
653 | * | |
654 | * btf_type_is_struct() because its member refers to | |
655 | * another type (through member->type). | |
1dc92851 DB |
656 | * |
657 | * btf_type_is_var() because the variable refers to | |
658 | * another type. btf_type_is_datasec() holds multiple | |
659 | * btf_type_is_var() types that need resolving. | |
660 | * | |
eb3f595d MKL |
661 | * btf_type_is_array() because its element (array->type) |
662 | * refers to another type. Array can be thought of a | |
663 | * special case of struct while array just has the same | |
664 | * member-type repeated by array->nelems of times. | |
665 | */ | |
666 | static bool btf_type_needs_resolve(const struct btf_type *t) | |
667 | { | |
668 | return btf_type_is_modifier(t) || | |
1dc92851 DB |
669 | btf_type_is_ptr(t) || |
670 | btf_type_is_struct(t) || | |
671 | btf_type_is_array(t) || | |
672 | btf_type_is_var(t) || | |
d7e7b42f | 673 | btf_type_is_func(t) || |
223f903e | 674 | btf_type_is_decl_tag(t) || |
1dc92851 | 675 | btf_type_is_datasec(t); |
eb3f595d MKL |
676 | } |
677 | ||
678 | /* t->size can be used */ | |
679 | static bool btf_type_has_size(const struct btf_type *t) | |
680 | { | |
681 | switch (BTF_INFO_KIND(t->info)) { | |
682 | case BTF_KIND_INT: | |
683 | case BTF_KIND_STRUCT: | |
684 | case BTF_KIND_UNION: | |
685 | case BTF_KIND_ENUM: | |
1dc92851 | 686 | case BTF_KIND_DATASEC: |
b1828f0b | 687 | case BTF_KIND_FLOAT: |
6089fb32 | 688 | case BTF_KIND_ENUM64: |
eb3f595d MKL |
689 | return true; |
690 | } | |
691 | ||
692 | return false; | |
693 | } | |
694 | ||
69b693f0 MKL |
695 | static const char *btf_int_encoding_str(u8 encoding) |
696 | { | |
697 | if (encoding == 0) | |
698 | return "(none)"; | |
699 | else if (encoding == BTF_INT_SIGNED) | |
700 | return "SIGNED"; | |
701 | else if (encoding == BTF_INT_CHAR) | |
702 | return "CHAR"; | |
703 | else if (encoding == BTF_INT_BOOL) | |
704 | return "BOOL"; | |
69b693f0 MKL |
705 | else |
706 | return "UNKN"; | |
707 | } | |
708 | ||
69b693f0 MKL |
709 | static u32 btf_type_int(const struct btf_type *t) |
710 | { | |
711 | return *(u32 *)(t + 1); | |
712 | } | |
713 | ||
714 | static const struct btf_array *btf_type_array(const struct btf_type *t) | |
715 | { | |
716 | return (const struct btf_array *)(t + 1); | |
717 | } | |
718 | ||
69b693f0 MKL |
719 | static const struct btf_enum *btf_type_enum(const struct btf_type *t) |
720 | { | |
721 | return (const struct btf_enum *)(t + 1); | |
722 | } | |
723 | ||
1dc92851 DB |
724 | static const struct btf_var *btf_type_var(const struct btf_type *t) |
725 | { | |
726 | return (const struct btf_var *)(t + 1); | |
727 | } | |
728 | ||
223f903e | 729 | static const struct btf_decl_tag *btf_type_decl_tag(const struct btf_type *t) |
b5ea834d | 730 | { |
223f903e | 731 | return (const struct btf_decl_tag *)(t + 1); |
b5ea834d YS |
732 | } |
733 | ||
6089fb32 YS |
734 | static const struct btf_enum64 *btf_type_enum64(const struct btf_type *t) |
735 | { | |
736 | return (const struct btf_enum64 *)(t + 1); | |
737 | } | |
738 | ||
69b693f0 MKL |
739 | static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t) |
740 | { | |
741 | return kind_ops[BTF_INFO_KIND(t->info)]; | |
742 | } | |
743 | ||
583c5318 | 744 | static bool btf_name_offset_valid(const struct btf *btf, u32 offset) |
69b693f0 | 745 | { |
951bb646 AN |
746 | if (!BTF_STR_OFFSET_VALID(offset)) |
747 | return false; | |
748 | ||
749 | while (offset < btf->start_str_off) | |
750 | btf = btf->base_btf; | |
751 | ||
752 | offset -= btf->start_str_off; | |
753 | return offset < btf->hdr.str_len; | |
69b693f0 MKL |
754 | } |
755 | ||
9724160b | 756 | static bool __btf_name_char_ok(char c, bool first) |
1dc92851 DB |
757 | { |
758 | if ((first ? !isalpha(c) : | |
759 | !isalnum(c)) && | |
760 | c != '_' && | |
9724160b | 761 | c != '.') |
1dc92851 DB |
762 | return false; |
763 | return true; | |
764 | } | |
765 | ||
951bb646 AN |
766 | static const char *btf_str_by_offset(const struct btf *btf, u32 offset) |
767 | { | |
768 | while (offset < btf->start_str_off) | |
769 | btf = btf->base_btf; | |
770 | ||
771 | offset -= btf->start_str_off; | |
772 | if (offset < btf->hdr.str_len) | |
773 | return &btf->strings[offset]; | |
774 | ||
775 | return NULL; | |
776 | } | |
777 | ||
9724160b | 778 | static bool __btf_name_valid(const struct btf *btf, u32 offset) |
2667a262 MKL |
779 | { |
780 | /* offset must be valid */ | |
951bb646 | 781 | const char *src = btf_str_by_offset(btf, offset); |
2667a262 MKL |
782 | const char *src_limit; |
783 | ||
9724160b | 784 | if (!__btf_name_char_ok(*src, true)) |
2667a262 MKL |
785 | return false; |
786 | ||
787 | /* set a limit on identifier length */ | |
788 | src_limit = src + KSYM_NAME_LEN; | |
789 | src++; | |
790 | while (*src && src < src_limit) { | |
9724160b | 791 | if (!__btf_name_char_ok(*src, false)) |
2667a262 MKL |
792 | return false; |
793 | src++; | |
794 | } | |
795 | ||
796 | return !*src; | |
797 | } | |
798 | ||
1dc92851 DB |
799 | static bool btf_name_valid_identifier(const struct btf *btf, u32 offset) |
800 | { | |
9724160b | 801 | return __btf_name_valid(btf, offset); |
1dc92851 DB |
802 | } |
803 | ||
804 | static bool btf_name_valid_section(const struct btf *btf, u32 offset) | |
805 | { | |
9724160b | 806 | return __btf_name_valid(btf, offset); |
1dc92851 DB |
807 | } |
808 | ||
23127b33 | 809 | static const char *__btf_name_by_offset(const struct btf *btf, u32 offset) |
69b693f0 | 810 | { |
951bb646 AN |
811 | const char *name; |
812 | ||
aea2f7b8 | 813 | if (!offset) |
69b693f0 | 814 | return "(anon)"; |
951bb646 AN |
815 | |
816 | name = btf_str_by_offset(btf, offset); | |
817 | return name ?: "(invalid-name-offset)"; | |
69b693f0 MKL |
818 | } |
819 | ||
23127b33 MKL |
820 | const char *btf_name_by_offset(const struct btf *btf, u32 offset) |
821 | { | |
951bb646 | 822 | return btf_str_by_offset(btf, offset); |
23127b33 MKL |
823 | } |
824 | ||
838e9690 | 825 | const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id) |
eb3f595d | 826 | { |
951bb646 AN |
827 | while (type_id < btf->start_id) |
828 | btf = btf->base_btf; | |
eb3f595d | 829 | |
951bb646 AN |
830 | type_id -= btf->start_id; |
831 | if (type_id >= btf->nr_types) | |
832 | return NULL; | |
eb3f595d MKL |
833 | return btf->types[type_id]; |
834 | } | |
84c6ac41 | 835 | EXPORT_SYMBOL_GPL(btf_type_by_id); |
eb3f595d | 836 | |
4ef5f574 MKL |
837 | /* |
838 | * Regular int is not a bit field and it must be either | |
b1e8818c | 839 | * u8/u16/u32/u64 or __int128. |
4ef5f574 MKL |
840 | */ |
841 | static bool btf_type_int_is_regular(const struct btf_type *t) | |
842 | { | |
36fc3c8c | 843 | u8 nr_bits, nr_bytes; |
4ef5f574 MKL |
844 | u32 int_data; |
845 | ||
846 | int_data = btf_type_int(t); | |
847 | nr_bits = BTF_INT_BITS(int_data); | |
848 | nr_bytes = BITS_ROUNDUP_BYTES(nr_bits); | |
849 | if (BITS_PER_BYTE_MASKED(nr_bits) || | |
850 | BTF_INT_OFFSET(int_data) || | |
851 | (nr_bytes != sizeof(u8) && nr_bytes != sizeof(u16) && | |
b1e8818c YS |
852 | nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64) && |
853 | nr_bytes != (2 * sizeof(u64)))) { | |
4ef5f574 MKL |
854 | return false; |
855 | } | |
856 | ||
857 | return true; | |
858 | } | |
859 | ||
9a1126b6 | 860 | /* |
ffa0c1cf YS |
861 | * Check that given struct member is a regular int with expected |
862 | * offset and size. | |
9a1126b6 | 863 | */ |
ffa0c1cf YS |
864 | bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s, |
865 | const struct btf_member *m, | |
866 | u32 expected_offset, u32 expected_size) | |
9a1126b6 | 867 | { |
ffa0c1cf YS |
868 | const struct btf_type *t; |
869 | u32 id, int_data; | |
870 | u8 nr_bits; | |
9a1126b6 | 871 | |
ffa0c1cf YS |
872 | id = m->type; |
873 | t = btf_type_id_size(btf, &id, NULL); | |
874 | if (!t || !btf_type_is_int(t)) | |
9a1126b6 RG |
875 | return false; |
876 | ||
877 | int_data = btf_type_int(t); | |
878 | nr_bits = BTF_INT_BITS(int_data); | |
ffa0c1cf YS |
879 | if (btf_type_kflag(s)) { |
880 | u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset); | |
881 | u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset); | |
882 | ||
883 | /* if kflag set, int should be a regular int and | |
884 | * bit offset should be at byte boundary. | |
885 | */ | |
886 | return !bitfield_size && | |
887 | BITS_ROUNDUP_BYTES(bit_offset) == expected_offset && | |
888 | BITS_ROUNDUP_BYTES(nr_bits) == expected_size; | |
889 | } | |
890 | ||
891 | if (BTF_INT_OFFSET(int_data) || | |
892 | BITS_PER_BYTE_MASKED(m->offset) || | |
893 | BITS_ROUNDUP_BYTES(m->offset) != expected_offset || | |
894 | BITS_PER_BYTE_MASKED(nr_bits) || | |
895 | BITS_ROUNDUP_BYTES(nr_bits) != expected_size) | |
9a1126b6 RG |
896 | return false; |
897 | ||
898 | return true; | |
899 | } | |
900 | ||
31d0bc81 AM |
901 | /* Similar to btf_type_skip_modifiers() but does not skip typedefs. */ |
902 | static const struct btf_type *btf_type_skip_qualifiers(const struct btf *btf, | |
903 | u32 id) | |
904 | { | |
905 | const struct btf_type *t = btf_type_by_id(btf, id); | |
906 | ||
907 | while (btf_type_is_modifier(t) && | |
908 | BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF) { | |
31d0bc81 AM |
909 | t = btf_type_by_id(btf, t->type); |
910 | } | |
911 | ||
912 | return t; | |
913 | } | |
914 | ||
915 | #define BTF_SHOW_MAX_ITER 10 | |
916 | ||
917 | #define BTF_KIND_BIT(kind) (1ULL << kind) | |
918 | ||
919 | /* | |
920 | * Populate show->state.name with type name information. | |
921 | * Format of type name is | |
922 | * | |
923 | * [.member_name = ] (type_name) | |
924 | */ | |
925 | static const char *btf_show_name(struct btf_show *show) | |
926 | { | |
927 | /* BTF_MAX_ITER array suffixes "[]" */ | |
928 | const char *array_suffixes = "[][][][][][][][][][]"; | |
929 | const char *array_suffix = &array_suffixes[strlen(array_suffixes)]; | |
930 | /* BTF_MAX_ITER pointer suffixes "*" */ | |
931 | const char *ptr_suffixes = "**********"; | |
932 | const char *ptr_suffix = &ptr_suffixes[strlen(ptr_suffixes)]; | |
933 | const char *name = NULL, *prefix = "", *parens = ""; | |
934 | const struct btf_member *m = show->state.member; | |
73b6eae5 | 935 | const struct btf_type *t; |
31d0bc81 AM |
936 | const struct btf_array *array; |
937 | u32 id = show->state.type_id; | |
938 | const char *member = NULL; | |
939 | bool show_member = false; | |
940 | u64 kinds = 0; | |
941 | int i; | |
942 | ||
943 | show->state.name[0] = '\0'; | |
944 | ||
945 | /* | |
946 | * Don't show type name if we're showing an array member; | |
947 | * in that case we show the array type so don't need to repeat | |
948 | * ourselves for each member. | |
949 | */ | |
950 | if (show->state.array_member) | |
951 | return ""; | |
952 | ||
953 | /* Retrieve member name, if any. */ | |
954 | if (m) { | |
955 | member = btf_name_by_offset(show->btf, m->name_off); | |
956 | show_member = strlen(member) > 0; | |
957 | id = m->type; | |
958 | } | |
959 | ||
960 | /* | |
961 | * Start with type_id, as we have resolved the struct btf_type * | |
962 | * via btf_modifier_show() past the parent typedef to the child | |
963 | * struct, int etc it is defined as. In such cases, the type_id | |
964 | * still represents the starting type while the struct btf_type * | |
965 | * in our show->state points at the resolved type of the typedef. | |
966 | */ | |
967 | t = btf_type_by_id(show->btf, id); | |
968 | if (!t) | |
969 | return ""; | |
970 | ||
971 | /* | |
972 | * The goal here is to build up the right number of pointer and | |
973 | * array suffixes while ensuring the type name for a typedef | |
974 | * is represented. Along the way we accumulate a list of | |
975 | * BTF kinds we have encountered, since these will inform later | |
976 | * display; for example, pointer types will not require an | |
977 | * opening "{" for struct, we will just display the pointer value. | |
978 | * | |
979 | * We also want to accumulate the right number of pointer or array | |
980 | * indices in the format string while iterating until we get to | |
981 | * the typedef/pointee/array member target type. | |
982 | * | |
983 | * We start by pointing at the end of pointer and array suffix | |
984 | * strings; as we accumulate pointers and arrays we move the pointer | |
985 | * or array string backwards so it will show the expected number of | |
986 | * '*' or '[]' for the type. BTF_SHOW_MAX_ITER of nesting of pointers | |
987 | * and/or arrays and typedefs are supported as a precaution. | |
988 | * | |
989 | * We also want to get typedef name while proceeding to resolve | |
990 | * type it points to so that we can add parentheses if it is a | |
991 | * "typedef struct" etc. | |
992 | */ | |
993 | for (i = 0; i < BTF_SHOW_MAX_ITER; i++) { | |
994 | ||
995 | switch (BTF_INFO_KIND(t->info)) { | |
996 | case BTF_KIND_TYPEDEF: | |
997 | if (!name) | |
998 | name = btf_name_by_offset(show->btf, | |
999 | t->name_off); | |
1000 | kinds |= BTF_KIND_BIT(BTF_KIND_TYPEDEF); | |
1001 | id = t->type; | |
1002 | break; | |
1003 | case BTF_KIND_ARRAY: | |
1004 | kinds |= BTF_KIND_BIT(BTF_KIND_ARRAY); | |
1005 | parens = "["; | |
1006 | if (!t) | |
1007 | return ""; | |
1008 | array = btf_type_array(t); | |
1009 | if (array_suffix > array_suffixes) | |
1010 | array_suffix -= 2; | |
1011 | id = array->type; | |
1012 | break; | |
1013 | case BTF_KIND_PTR: | |
1014 | kinds |= BTF_KIND_BIT(BTF_KIND_PTR); | |
1015 | if (ptr_suffix > ptr_suffixes) | |
1016 | ptr_suffix -= 1; | |
1017 | id = t->type; | |
1018 | break; | |
1019 | default: | |
1020 | id = 0; | |
1021 | break; | |
1022 | } | |
1023 | if (!id) | |
1024 | break; | |
1025 | t = btf_type_skip_qualifiers(show->btf, id); | |
1026 | } | |
1027 | /* We may not be able to represent this type; bail to be safe */ | |
1028 | if (i == BTF_SHOW_MAX_ITER) | |
1029 | return ""; | |
1030 | ||
1031 | if (!name) | |
1032 | name = btf_name_by_offset(show->btf, t->name_off); | |
1033 | ||
1034 | switch (BTF_INFO_KIND(t->info)) { | |
1035 | case BTF_KIND_STRUCT: | |
1036 | case BTF_KIND_UNION: | |
1037 | prefix = BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT ? | |
1038 | "struct" : "union"; | |
1039 | /* if it's an array of struct/union, parens is already set */ | |
1040 | if (!(kinds & (BTF_KIND_BIT(BTF_KIND_ARRAY)))) | |
1041 | parens = "{"; | |
1042 | break; | |
1043 | case BTF_KIND_ENUM: | |
6089fb32 | 1044 | case BTF_KIND_ENUM64: |
31d0bc81 AM |
1045 | prefix = "enum"; |
1046 | break; | |
1047 | default: | |
1048 | break; | |
1049 | } | |
1050 | ||
1051 | /* pointer does not require parens */ | |
1052 | if (kinds & BTF_KIND_BIT(BTF_KIND_PTR)) | |
1053 | parens = ""; | |
1054 | /* typedef does not require struct/union/enum prefix */ | |
1055 | if (kinds & BTF_KIND_BIT(BTF_KIND_TYPEDEF)) | |
1056 | prefix = ""; | |
1057 | ||
1058 | if (!name) | |
1059 | name = ""; | |
1060 | ||
1061 | /* Even if we don't want type name info, we want parentheses etc */ | |
1062 | if (show->flags & BTF_SHOW_NONAME) | |
1063 | snprintf(show->state.name, sizeof(show->state.name), "%s", | |
1064 | parens); | |
1065 | else | |
1066 | snprintf(show->state.name, sizeof(show->state.name), | |
1067 | "%s%s%s(%s%s%s%s%s%s)%s", | |
1068 | /* first 3 strings comprise ".member = " */ | |
1069 | show_member ? "." : "", | |
1070 | show_member ? member : "", | |
1071 | show_member ? " = " : "", | |
1072 | /* ...next is our prefix (struct, enum, etc) */ | |
1073 | prefix, | |
1074 | strlen(prefix) > 0 && strlen(name) > 0 ? " " : "", | |
1075 | /* ...this is the type name itself */ | |
1076 | name, | |
1077 | /* ...suffixed by the appropriate '*', '[]' suffixes */ | |
1078 | strlen(ptr_suffix) > 0 ? " " : "", ptr_suffix, | |
1079 | array_suffix, parens); | |
1080 | ||
1081 | return show->state.name; | |
1082 | } | |
1083 | ||
1084 | static const char *__btf_show_indent(struct btf_show *show) | |
1085 | { | |
1086 | const char *indents = " "; | |
1087 | const char *indent = &indents[strlen(indents)]; | |
1088 | ||
1089 | if ((indent - show->state.depth) >= indents) | |
1090 | return indent - show->state.depth; | |
1091 | return indents; | |
1092 | } | |
1093 | ||
1094 | static const char *btf_show_indent(struct btf_show *show) | |
1095 | { | |
1096 | return show->flags & BTF_SHOW_COMPACT ? "" : __btf_show_indent(show); | |
1097 | } | |
1098 | ||
1099 | static const char *btf_show_newline(struct btf_show *show) | |
1100 | { | |
1101 | return show->flags & BTF_SHOW_COMPACT ? "" : "\n"; | |
1102 | } | |
1103 | ||
1104 | static const char *btf_show_delim(struct btf_show *show) | |
1105 | { | |
1106 | if (show->state.depth == 0) | |
1107 | return ""; | |
1108 | ||
1109 | if ((show->flags & BTF_SHOW_COMPACT) && show->state.type && | |
1110 | BTF_INFO_KIND(show->state.type->info) == BTF_KIND_UNION) | |
1111 | return "|"; | |
1112 | ||
1113 | return ","; | |
1114 | } | |
1115 | ||
1116 | __printf(2, 3) static void btf_show(struct btf_show *show, const char *fmt, ...) | |
1117 | { | |
1118 | va_list args; | |
1119 | ||
1120 | if (!show->state.depth_check) { | |
1121 | va_start(args, fmt); | |
1122 | show->showfn(show, fmt, args); | |
1123 | va_end(args); | |
1124 | } | |
1125 | } | |
1126 | ||
1127 | /* Macros are used here as btf_show_type_value[s]() prepends and appends | |
1128 | * format specifiers to the format specifier passed in; these do the work of | |
1129 | * adding indentation, delimiters etc while the caller simply has to specify | |
1130 | * the type value(s) in the format specifier + value(s). | |
1131 | */ | |
1132 | #define btf_show_type_value(show, fmt, value) \ | |
1133 | do { \ | |
a2a5580f BD |
1134 | if ((value) != (__typeof__(value))0 || \ |
1135 | (show->flags & BTF_SHOW_ZERO) || \ | |
31d0bc81 AM |
1136 | show->state.depth == 0) { \ |
1137 | btf_show(show, "%s%s" fmt "%s%s", \ | |
1138 | btf_show_indent(show), \ | |
1139 | btf_show_name(show), \ | |
1140 | value, btf_show_delim(show), \ | |
1141 | btf_show_newline(show)); \ | |
1142 | if (show->state.depth > show->state.depth_to_show) \ | |
1143 | show->state.depth_to_show = show->state.depth; \ | |
1144 | } \ | |
1145 | } while (0) | |
1146 | ||
1147 | #define btf_show_type_values(show, fmt, ...) \ | |
1148 | do { \ | |
1149 | btf_show(show, "%s%s" fmt "%s%s", btf_show_indent(show), \ | |
1150 | btf_show_name(show), \ | |
1151 | __VA_ARGS__, btf_show_delim(show), \ | |
1152 | btf_show_newline(show)); \ | |
1153 | if (show->state.depth > show->state.depth_to_show) \ | |
1154 | show->state.depth_to_show = show->state.depth; \ | |
1155 | } while (0) | |
1156 | ||
1157 | /* How much is left to copy to safe buffer after @data? */ | |
1158 | static int btf_show_obj_size_left(struct btf_show *show, void *data) | |
1159 | { | |
1160 | return show->obj.head + show->obj.size - data; | |
1161 | } | |
1162 | ||
1163 | /* Is object pointed to by @data of @size already copied to our safe buffer? */ | |
1164 | static bool btf_show_obj_is_safe(struct btf_show *show, void *data, int size) | |
1165 | { | |
1166 | return data >= show->obj.data && | |
1167 | (data + size) < (show->obj.data + BTF_SHOW_OBJ_SAFE_SIZE); | |
1168 | } | |
1169 | ||
1170 | /* | |
1171 | * If object pointed to by @data of @size falls within our safe buffer, return | |
1172 | * the equivalent pointer to the same safe data. Assumes | |
1173 | * copy_from_kernel_nofault() has already happened and our safe buffer is | |
1174 | * populated. | |
1175 | */ | |
1176 | static void *__btf_show_obj_safe(struct btf_show *show, void *data, int size) | |
1177 | { | |
1178 | if (btf_show_obj_is_safe(show, data, size)) | |
1179 | return show->obj.safe + (data - show->obj.data); | |
1180 | return NULL; | |
1181 | } | |
1182 | ||
1183 | /* | |
1184 | * Return a safe-to-access version of data pointed to by @data. | |
1185 | * We do this by copying the relevant amount of information | |
1186 | * to the struct btf_show obj.safe buffer using copy_from_kernel_nofault(). | |
1187 | * | |
1188 | * If BTF_SHOW_UNSAFE is specified, just return data as-is; no | |
1189 | * safe copy is needed. | |
1190 | * | |
1191 | * Otherwise we need to determine if we have the required amount | |
1192 | * of data (determined by the @data pointer and the size of the | |
1193 | * largest base type we can encounter (represented by | |
1194 | * BTF_SHOW_OBJ_BASE_TYPE_SIZE). Having that much data ensures | |
1195 | * that we will be able to print some of the current object, | |
1196 | * and if more is needed a copy will be triggered. | |
1197 | * Some objects such as structs will not fit into the buffer; | |
1198 | * in such cases additional copies when we iterate over their | |
1199 | * members may be needed. | |
1200 | * | |
1201 | * btf_show_obj_safe() is used to return a safe buffer for | |
1202 | * btf_show_start_type(); this ensures that as we recurse into | |
1203 | * nested types we always have safe data for the given type. | |
1204 | * This approach is somewhat wasteful; it's possible for example | |
1205 | * that when iterating over a large union we'll end up copying the | |
1206 | * same data repeatedly, but the goal is safety not performance. | |
1207 | * We use stack data as opposed to per-CPU buffers because the | |
1208 | * iteration over a type can take some time, and preemption handling | |
1209 | * would greatly complicate use of the safe buffer. | |
1210 | */ | |
1211 | static void *btf_show_obj_safe(struct btf_show *show, | |
1212 | const struct btf_type *t, | |
1213 | void *data) | |
1214 | { | |
1215 | const struct btf_type *rt; | |
1216 | int size_left, size; | |
1217 | void *safe = NULL; | |
1218 | ||
1219 | if (show->flags & BTF_SHOW_UNSAFE) | |
1220 | return data; | |
1221 | ||
1222 | rt = btf_resolve_size(show->btf, t, &size); | |
1223 | if (IS_ERR(rt)) { | |
1224 | show->state.status = PTR_ERR(rt); | |
1225 | return NULL; | |
1226 | } | |
1227 | ||
1228 | /* | |
1229 | * Is this toplevel object? If so, set total object size and | |
1230 | * initialize pointers. Otherwise check if we still fall within | |
1231 | * our safe object data. | |
1232 | */ | |
1233 | if (show->state.depth == 0) { | |
1234 | show->obj.size = size; | |
1235 | show->obj.head = data; | |
1236 | } else { | |
1237 | /* | |
1238 | * If the size of the current object is > our remaining | |
1239 | * safe buffer we _may_ need to do a new copy. However | |
1240 | * consider the case of a nested struct; it's size pushes | |
1241 | * us over the safe buffer limit, but showing any individual | |
1242 | * struct members does not. In such cases, we don't need | |
1243 | * to initiate a fresh copy yet; however we definitely need | |
1244 | * at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes left | |
1245 | * in our buffer, regardless of the current object size. | |
1246 | * The logic here is that as we resolve types we will | |
1247 | * hit a base type at some point, and we need to be sure | |
1248 | * the next chunk of data is safely available to display | |
1249 | * that type info safely. We cannot rely on the size of | |
1250 | * the current object here because it may be much larger | |
1251 | * than our current buffer (e.g. task_struct is 8k). | |
1252 | * All we want to do here is ensure that we can print the | |
1253 | * next basic type, which we can if either | |
1254 | * - the current type size is within the safe buffer; or | |
1255 | * - at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes are left in | |
1256 | * the safe buffer. | |
1257 | */ | |
1258 | safe = __btf_show_obj_safe(show, data, | |
1259 | min(size, | |
1260 | BTF_SHOW_OBJ_BASE_TYPE_SIZE)); | |
1261 | } | |
1262 | ||
1263 | /* | |
1264 | * We need a new copy to our safe object, either because we haven't | |
8fb33b60 | 1265 | * yet copied and are initializing safe data, or because the data |
31d0bc81 AM |
1266 | * we want falls outside the boundaries of the safe object. |
1267 | */ | |
1268 | if (!safe) { | |
1269 | size_left = btf_show_obj_size_left(show, data); | |
1270 | if (size_left > BTF_SHOW_OBJ_SAFE_SIZE) | |
1271 | size_left = BTF_SHOW_OBJ_SAFE_SIZE; | |
1272 | show->state.status = copy_from_kernel_nofault(show->obj.safe, | |
1273 | data, size_left); | |
1274 | if (!show->state.status) { | |
1275 | show->obj.data = data; | |
1276 | safe = show->obj.safe; | |
1277 | } | |
1278 | } | |
1279 | ||
1280 | return safe; | |
1281 | } | |
1282 | ||
1283 | /* | |
1284 | * Set the type we are starting to show and return a safe data pointer | |
1285 | * to be used for showing the associated data. | |
1286 | */ | |
1287 | static void *btf_show_start_type(struct btf_show *show, | |
1288 | const struct btf_type *t, | |
1289 | u32 type_id, void *data) | |
1290 | { | |
1291 | show->state.type = t; | |
1292 | show->state.type_id = type_id; | |
1293 | show->state.name[0] = '\0'; | |
1294 | ||
1295 | return btf_show_obj_safe(show, t, data); | |
1296 | } | |
1297 | ||
1298 | static void btf_show_end_type(struct btf_show *show) | |
1299 | { | |
1300 | show->state.type = NULL; | |
1301 | show->state.type_id = 0; | |
1302 | show->state.name[0] = '\0'; | |
1303 | } | |
1304 | ||
1305 | static void *btf_show_start_aggr_type(struct btf_show *show, | |
1306 | const struct btf_type *t, | |
1307 | u32 type_id, void *data) | |
1308 | { | |
1309 | void *safe_data = btf_show_start_type(show, t, type_id, data); | |
1310 | ||
1311 | if (!safe_data) | |
1312 | return safe_data; | |
1313 | ||
1314 | btf_show(show, "%s%s%s", btf_show_indent(show), | |
1315 | btf_show_name(show), | |
1316 | btf_show_newline(show)); | |
1317 | show->state.depth++; | |
1318 | return safe_data; | |
1319 | } | |
1320 | ||
1321 | static void btf_show_end_aggr_type(struct btf_show *show, | |
1322 | const char *suffix) | |
1323 | { | |
1324 | show->state.depth--; | |
1325 | btf_show(show, "%s%s%s%s", btf_show_indent(show), suffix, | |
1326 | btf_show_delim(show), btf_show_newline(show)); | |
1327 | btf_show_end_type(show); | |
1328 | } | |
1329 | ||
1330 | static void btf_show_start_member(struct btf_show *show, | |
1331 | const struct btf_member *m) | |
1332 | { | |
1333 | show->state.member = m; | |
1334 | } | |
1335 | ||
1336 | static void btf_show_start_array_member(struct btf_show *show) | |
1337 | { | |
1338 | show->state.array_member = 1; | |
1339 | btf_show_start_member(show, NULL); | |
1340 | } | |
1341 | ||
1342 | static void btf_show_end_member(struct btf_show *show) | |
1343 | { | |
1344 | show->state.member = NULL; | |
1345 | } | |
1346 | ||
1347 | static void btf_show_end_array_member(struct btf_show *show) | |
1348 | { | |
1349 | show->state.array_member = 0; | |
1350 | btf_show_end_member(show); | |
1351 | } | |
1352 | ||
1353 | static void *btf_show_start_array_type(struct btf_show *show, | |
1354 | const struct btf_type *t, | |
1355 | u32 type_id, | |
1356 | u16 array_encoding, | |
1357 | void *data) | |
1358 | { | |
1359 | show->state.array_encoding = array_encoding; | |
1360 | show->state.array_terminated = 0; | |
1361 | return btf_show_start_aggr_type(show, t, type_id, data); | |
1362 | } | |
1363 | ||
1364 | static void btf_show_end_array_type(struct btf_show *show) | |
1365 | { | |
1366 | show->state.array_encoding = 0; | |
1367 | show->state.array_terminated = 0; | |
1368 | btf_show_end_aggr_type(show, "]"); | |
1369 | } | |
1370 | ||
1371 | static void *btf_show_start_struct_type(struct btf_show *show, | |
1372 | const struct btf_type *t, | |
1373 | u32 type_id, | |
1374 | void *data) | |
1375 | { | |
1376 | return btf_show_start_aggr_type(show, t, type_id, data); | |
1377 | } | |
1378 | ||
1379 | static void btf_show_end_struct_type(struct btf_show *show) | |
1380 | { | |
1381 | btf_show_end_aggr_type(show, "}"); | |
1382 | } | |
1383 | ||
69b693f0 MKL |
1384 | __printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log, |
1385 | const char *fmt, ...) | |
1386 | { | |
1387 | va_list args; | |
1388 | ||
1389 | va_start(args, fmt); | |
1390 | bpf_verifier_vlog(log, fmt, args); | |
1391 | va_end(args); | |
1392 | } | |
1393 | ||
1394 | __printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env, | |
1395 | const char *fmt, ...) | |
1396 | { | |
1397 | struct bpf_verifier_log *log = &env->log; | |
1398 | va_list args; | |
1399 | ||
1400 | if (!bpf_verifier_log_needed(log)) | |
1401 | return; | |
1402 | ||
1403 | va_start(args, fmt); | |
1404 | bpf_verifier_vlog(log, fmt, args); | |
1405 | va_end(args); | |
1406 | } | |
1407 | ||
1408 | __printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env, | |
1409 | const struct btf_type *t, | |
1410 | bool log_details, | |
1411 | const char *fmt, ...) | |
1412 | { | |
1413 | struct bpf_verifier_log *log = &env->log; | |
69b693f0 MKL |
1414 | struct btf *btf = env->btf; |
1415 | va_list args; | |
1416 | ||
1417 | if (!bpf_verifier_log_needed(log)) | |
1418 | return; | |
1419 | ||
9cb61e50 CB |
1420 | if (log->level == BPF_LOG_KERNEL) { |
1421 | /* btf verifier prints all types it is processing via | |
1422 | * btf_verifier_log_type(..., fmt = NULL). | |
1423 | * Skip those prints for in-kernel BTF verification. | |
1424 | */ | |
1425 | if (!fmt) | |
1426 | return; | |
1427 | ||
1428 | /* Skip logging when loading module BTF with mismatches permitted */ | |
1429 | if (env->btf->base_btf && IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) | |
1430 | return; | |
1431 | } | |
8580ac94 | 1432 | |
69b693f0 MKL |
1433 | __btf_verifier_log(log, "[%u] %s %s%s", |
1434 | env->log_type_id, | |
571f9738 | 1435 | btf_type_str(t), |
23127b33 | 1436 | __btf_name_by_offset(btf, t->name_off), |
69b693f0 MKL |
1437 | log_details ? " " : ""); |
1438 | ||
1439 | if (log_details) | |
1440 | btf_type_ops(t)->log_details(env, t); | |
1441 | ||
1442 | if (fmt && *fmt) { | |
1443 | __btf_verifier_log(log, " "); | |
1444 | va_start(args, fmt); | |
1445 | bpf_verifier_vlog(log, fmt, args); | |
1446 | va_end(args); | |
1447 | } | |
1448 | ||
1449 | __btf_verifier_log(log, "\n"); | |
1450 | } | |
1451 | ||
1452 | #define btf_verifier_log_type(env, t, ...) \ | |
1453 | __btf_verifier_log_type((env), (t), true, __VA_ARGS__) | |
1454 | #define btf_verifier_log_basic(env, t, ...) \ | |
1455 | __btf_verifier_log_type((env), (t), false, __VA_ARGS__) | |
1456 | ||
1457 | __printf(4, 5) | |
1458 | static void btf_verifier_log_member(struct btf_verifier_env *env, | |
1459 | const struct btf_type *struct_type, | |
1460 | const struct btf_member *member, | |
1461 | const char *fmt, ...) | |
1462 | { | |
1463 | struct bpf_verifier_log *log = &env->log; | |
1464 | struct btf *btf = env->btf; | |
1465 | va_list args; | |
1466 | ||
1467 | if (!bpf_verifier_log_needed(log)) | |
1468 | return; | |
1469 | ||
9cb61e50 CB |
1470 | if (log->level == BPF_LOG_KERNEL) { |
1471 | if (!fmt) | |
1472 | return; | |
1473 | ||
1474 | /* Skip logging when loading module BTF with mismatches permitted */ | |
1475 | if (env->btf->base_btf && IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) | |
1476 | return; | |
1477 | } | |
1478 | ||
eb3f595d MKL |
1479 | /* The CHECK_META phase already did a btf dump. |
1480 | * | |
1481 | * If member is logged again, it must hit an error in | |
1482 | * parsing this member. It is useful to print out which | |
1483 | * struct this member belongs to. | |
1484 | */ | |
1485 | if (env->phase != CHECK_META) | |
1486 | btf_verifier_log_type(env, struct_type, NULL); | |
1487 | ||
9d5f9f70 YS |
1488 | if (btf_type_kflag(struct_type)) |
1489 | __btf_verifier_log(log, | |
1490 | "\t%s type_id=%u bitfield_size=%u bits_offset=%u", | |
1491 | __btf_name_by_offset(btf, member->name_off), | |
1492 | member->type, | |
1493 | BTF_MEMBER_BITFIELD_SIZE(member->offset), | |
1494 | BTF_MEMBER_BIT_OFFSET(member->offset)); | |
1495 | else | |
1496 | __btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u", | |
1497 | __btf_name_by_offset(btf, member->name_off), | |
1498 | member->type, member->offset); | |
69b693f0 MKL |
1499 | |
1500 | if (fmt && *fmt) { | |
1501 | __btf_verifier_log(log, " "); | |
1502 | va_start(args, fmt); | |
1503 | bpf_verifier_vlog(log, fmt, args); | |
1504 | va_end(args); | |
1505 | } | |
1506 | ||
1507 | __btf_verifier_log(log, "\n"); | |
1508 | } | |
1509 | ||
1dc92851 DB |
1510 | __printf(4, 5) |
1511 | static void btf_verifier_log_vsi(struct btf_verifier_env *env, | |
1512 | const struct btf_type *datasec_type, | |
1513 | const struct btf_var_secinfo *vsi, | |
1514 | const char *fmt, ...) | |
1515 | { | |
1516 | struct bpf_verifier_log *log = &env->log; | |
1517 | va_list args; | |
1518 | ||
1519 | if (!bpf_verifier_log_needed(log)) | |
1520 | return; | |
8580ac94 AS |
1521 | if (log->level == BPF_LOG_KERNEL && !fmt) |
1522 | return; | |
1dc92851 DB |
1523 | if (env->phase != CHECK_META) |
1524 | btf_verifier_log_type(env, datasec_type, NULL); | |
1525 | ||
1526 | __btf_verifier_log(log, "\t type_id=%u offset=%u size=%u", | |
1527 | vsi->type, vsi->offset, vsi->size); | |
1528 | if (fmt && *fmt) { | |
1529 | __btf_verifier_log(log, " "); | |
1530 | va_start(args, fmt); | |
1531 | bpf_verifier_vlog(log, fmt, args); | |
1532 | va_end(args); | |
1533 | } | |
1534 | ||
1535 | __btf_verifier_log(log, "\n"); | |
1536 | } | |
1537 | ||
f80442a4 MKL |
1538 | static void btf_verifier_log_hdr(struct btf_verifier_env *env, |
1539 | u32 btf_data_size) | |
69b693f0 MKL |
1540 | { |
1541 | struct bpf_verifier_log *log = &env->log; | |
1542 | const struct btf *btf = env->btf; | |
1543 | const struct btf_header *hdr; | |
1544 | ||
1545 | if (!bpf_verifier_log_needed(log)) | |
1546 | return; | |
1547 | ||
8580ac94 AS |
1548 | if (log->level == BPF_LOG_KERNEL) |
1549 | return; | |
f80442a4 | 1550 | hdr = &btf->hdr; |
69b693f0 MKL |
1551 | __btf_verifier_log(log, "magic: 0x%x\n", hdr->magic); |
1552 | __btf_verifier_log(log, "version: %u\n", hdr->version); | |
1553 | __btf_verifier_log(log, "flags: 0x%x\n", hdr->flags); | |
f80442a4 | 1554 | __btf_verifier_log(log, "hdr_len: %u\n", hdr->hdr_len); |
69b693f0 | 1555 | __btf_verifier_log(log, "type_off: %u\n", hdr->type_off); |
f80442a4 | 1556 | __btf_verifier_log(log, "type_len: %u\n", hdr->type_len); |
69b693f0 MKL |
1557 | __btf_verifier_log(log, "str_off: %u\n", hdr->str_off); |
1558 | __btf_verifier_log(log, "str_len: %u\n", hdr->str_len); | |
f80442a4 | 1559 | __btf_verifier_log(log, "btf_total_size: %u\n", btf_data_size); |
69b693f0 MKL |
1560 | } |
1561 | ||
1562 | static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t) | |
1563 | { | |
1564 | struct btf *btf = env->btf; | |
1565 | ||
951bb646 | 1566 | if (btf->types_size == btf->nr_types) { |
69b693f0 MKL |
1567 | /* Expand 'types' array */ |
1568 | ||
1569 | struct btf_type **new_types; | |
1570 | u32 expand_by, new_size; | |
1571 | ||
951bb646 | 1572 | if (btf->start_id + btf->types_size == BTF_MAX_TYPE) { |
69b693f0 MKL |
1573 | btf_verifier_log(env, "Exceeded max num of types"); |
1574 | return -E2BIG; | |
1575 | } | |
1576 | ||
1577 | expand_by = max_t(u32, btf->types_size >> 2, 16); | |
aea2f7b8 | 1578 | new_size = min_t(u32, BTF_MAX_TYPE, |
69b693f0 MKL |
1579 | btf->types_size + expand_by); |
1580 | ||
778e1cdd | 1581 | new_types = kvcalloc(new_size, sizeof(*new_types), |
69b693f0 MKL |
1582 | GFP_KERNEL | __GFP_NOWARN); |
1583 | if (!new_types) | |
1584 | return -ENOMEM; | |
1585 | ||
951bb646 AN |
1586 | if (btf->nr_types == 0) { |
1587 | if (!btf->base_btf) { | |
1588 | /* lazily init VOID type */ | |
1589 | new_types[0] = &btf_void; | |
1590 | btf->nr_types++; | |
1591 | } | |
1592 | } else { | |
69b693f0 | 1593 | memcpy(new_types, btf->types, |
951bb646 AN |
1594 | sizeof(*btf->types) * btf->nr_types); |
1595 | } | |
69b693f0 MKL |
1596 | |
1597 | kvfree(btf->types); | |
1598 | btf->types = new_types; | |
1599 | btf->types_size = new_size; | |
1600 | } | |
1601 | ||
951bb646 | 1602 | btf->types[btf->nr_types++] = t; |
69b693f0 MKL |
1603 | |
1604 | return 0; | |
1605 | } | |
1606 | ||
78958fca MKL |
1607 | static int btf_alloc_id(struct btf *btf) |
1608 | { | |
1609 | int id; | |
1610 | ||
1611 | idr_preload(GFP_KERNEL); | |
1612 | spin_lock_bh(&btf_idr_lock); | |
1613 | id = idr_alloc_cyclic(&btf_idr, btf, 1, INT_MAX, GFP_ATOMIC); | |
1614 | if (id > 0) | |
1615 | btf->id = id; | |
1616 | spin_unlock_bh(&btf_idr_lock); | |
1617 | idr_preload_end(); | |
1618 | ||
1619 | if (WARN_ON_ONCE(!id)) | |
1620 | return -ENOSPC; | |
1621 | ||
1622 | return id > 0 ? 0 : id; | |
1623 | } | |
1624 | ||
1625 | static void btf_free_id(struct btf *btf) | |
1626 | { | |
1627 | unsigned long flags; | |
1628 | ||
1629 | /* | |
1630 | * In map-in-map, calling map_delete_elem() on outer | |
1631 | * map will call bpf_map_put on the inner map. | |
1632 | * It will then eventually call btf_free_id() | |
1633 | * on the inner map. Some of the map_delete_elem() | |
1634 | * implementation may have irq disabled, so | |
1635 | * we need to use the _irqsave() version instead | |
1636 | * of the _bh() version. | |
1637 | */ | |
1638 | spin_lock_irqsave(&btf_idr_lock, flags); | |
1639 | idr_remove(&btf_idr, btf->id); | |
1640 | spin_unlock_irqrestore(&btf_idr_lock, flags); | |
1641 | } | |
1642 | ||
dee872e1 KKD |
1643 | static void btf_free_kfunc_set_tab(struct btf *btf) |
1644 | { | |
1645 | struct btf_kfunc_set_tab *tab = btf->kfunc_set_tab; | |
a4703e31 | 1646 | int hook; |
dee872e1 KKD |
1647 | |
1648 | if (!tab) | |
1649 | return; | |
1650 | /* For module BTF, we directly assign the sets being registered, so | |
1651 | * there is nothing to free except kfunc_set_tab. | |
1652 | */ | |
1653 | if (btf_is_module(btf)) | |
1654 | goto free_tab; | |
a4703e31 KKD |
1655 | for (hook = 0; hook < ARRAY_SIZE(tab->sets); hook++) |
1656 | kfree(tab->sets[hook]); | |
dee872e1 KKD |
1657 | free_tab: |
1658 | kfree(tab); | |
1659 | btf->kfunc_set_tab = NULL; | |
1660 | } | |
1661 | ||
5ce937d6 KKD |
1662 | static void btf_free_dtor_kfunc_tab(struct btf *btf) |
1663 | { | |
1664 | struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab; | |
1665 | ||
1666 | if (!tab) | |
1667 | return; | |
1668 | kfree(tab); | |
1669 | btf->dtor_kfunc_tab = NULL; | |
1670 | } | |
1671 | ||
8ffa5cc1 KKD |
1672 | static void btf_struct_metas_free(struct btf_struct_metas *tab) |
1673 | { | |
1674 | int i; | |
1675 | ||
1676 | if (!tab) | |
1677 | return; | |
cd2a8079 | 1678 | for (i = 0; i < tab->cnt; i++) |
8ffa5cc1 | 1679 | btf_record_free(tab->types[i].record); |
8ffa5cc1 KKD |
1680 | kfree(tab); |
1681 | } | |
1682 | ||
1683 | static void btf_free_struct_meta_tab(struct btf *btf) | |
1684 | { | |
1685 | struct btf_struct_metas *tab = btf->struct_meta_tab; | |
1686 | ||
1687 | btf_struct_metas_free(tab); | |
1688 | btf->struct_meta_tab = NULL; | |
1689 | } | |
1690 | ||
69b693f0 MKL |
1691 | static void btf_free(struct btf *btf) |
1692 | { | |
8ffa5cc1 | 1693 | btf_free_struct_meta_tab(btf); |
5ce937d6 | 1694 | btf_free_dtor_kfunc_tab(btf); |
dee872e1 | 1695 | btf_free_kfunc_set_tab(btf); |
69b693f0 | 1696 | kvfree(btf->types); |
eb3f595d MKL |
1697 | kvfree(btf->resolved_sizes); |
1698 | kvfree(btf->resolved_ids); | |
69b693f0 MKL |
1699 | kvfree(btf->data); |
1700 | kfree(btf); | |
1701 | } | |
1702 | ||
78958fca | 1703 | static void btf_free_rcu(struct rcu_head *rcu) |
f56a653c | 1704 | { |
78958fca MKL |
1705 | struct btf *btf = container_of(rcu, struct btf, rcu); |
1706 | ||
1707 | btf_free(btf); | |
f56a653c MKL |
1708 | } |
1709 | ||
22dc4a0f AN |
1710 | void btf_get(struct btf *btf) |
1711 | { | |
1712 | refcount_inc(&btf->refcnt); | |
1713 | } | |
1714 | ||
f56a653c MKL |
1715 | void btf_put(struct btf *btf) |
1716 | { | |
78958fca MKL |
1717 | if (btf && refcount_dec_and_test(&btf->refcnt)) { |
1718 | btf_free_id(btf); | |
1719 | call_rcu(&btf->rcu, btf_free_rcu); | |
1720 | } | |
f56a653c MKL |
1721 | } |
1722 | ||
eb3f595d MKL |
1723 | static int env_resolve_init(struct btf_verifier_env *env) |
1724 | { | |
1725 | struct btf *btf = env->btf; | |
1726 | u32 nr_types = btf->nr_types; | |
1727 | u32 *resolved_sizes = NULL; | |
1728 | u32 *resolved_ids = NULL; | |
1729 | u8 *visit_states = NULL; | |
1730 | ||
951bb646 | 1731 | resolved_sizes = kvcalloc(nr_types, sizeof(*resolved_sizes), |
eb3f595d MKL |
1732 | GFP_KERNEL | __GFP_NOWARN); |
1733 | if (!resolved_sizes) | |
1734 | goto nomem; | |
1735 | ||
951bb646 | 1736 | resolved_ids = kvcalloc(nr_types, sizeof(*resolved_ids), |
eb3f595d MKL |
1737 | GFP_KERNEL | __GFP_NOWARN); |
1738 | if (!resolved_ids) | |
1739 | goto nomem; | |
1740 | ||
951bb646 | 1741 | visit_states = kvcalloc(nr_types, sizeof(*visit_states), |
eb3f595d MKL |
1742 | GFP_KERNEL | __GFP_NOWARN); |
1743 | if (!visit_states) | |
1744 | goto nomem; | |
1745 | ||
1746 | btf->resolved_sizes = resolved_sizes; | |
1747 | btf->resolved_ids = resolved_ids; | |
1748 | env->visit_states = visit_states; | |
1749 | ||
1750 | return 0; | |
1751 | ||
1752 | nomem: | |
1753 | kvfree(resolved_sizes); | |
1754 | kvfree(resolved_ids); | |
1755 | kvfree(visit_states); | |
1756 | return -ENOMEM; | |
1757 | } | |
1758 | ||
69b693f0 MKL |
1759 | static void btf_verifier_env_free(struct btf_verifier_env *env) |
1760 | { | |
eb3f595d | 1761 | kvfree(env->visit_states); |
69b693f0 MKL |
1762 | kfree(env); |
1763 | } | |
1764 | ||
eb3f595d MKL |
1765 | static bool env_type_is_resolve_sink(const struct btf_verifier_env *env, |
1766 | const struct btf_type *next_type) | |
1767 | { | |
1768 | switch (env->resolve_mode) { | |
1769 | case RESOLVE_TBD: | |
1770 | /* int, enum or void is a sink */ | |
1771 | return !btf_type_needs_resolve(next_type); | |
1772 | case RESOLVE_PTR: | |
2667a262 MKL |
1773 | /* int, enum, void, struct, array, func or func_proto is a sink |
1774 | * for ptr | |
1775 | */ | |
eb3f595d MKL |
1776 | return !btf_type_is_modifier(next_type) && |
1777 | !btf_type_is_ptr(next_type); | |
1778 | case RESOLVE_STRUCT_OR_ARRAY: | |
2667a262 MKL |
1779 | /* int, enum, void, ptr, func or func_proto is a sink |
1780 | * for struct and array | |
1781 | */ | |
eb3f595d MKL |
1782 | return !btf_type_is_modifier(next_type) && |
1783 | !btf_type_is_array(next_type) && | |
1784 | !btf_type_is_struct(next_type); | |
1785 | default: | |
53c8036c | 1786 | BUG(); |
eb3f595d MKL |
1787 | } |
1788 | } | |
1789 | ||
1790 | static bool env_type_is_resolved(const struct btf_verifier_env *env, | |
1791 | u32 type_id) | |
1792 | { | |
951bb646 AN |
1793 | /* base BTF types should be resolved by now */ |
1794 | if (type_id < env->btf->start_id) | |
1795 | return true; | |
1796 | ||
1797 | return env->visit_states[type_id - env->btf->start_id] == RESOLVED; | |
eb3f595d MKL |
1798 | } |
1799 | ||
1800 | static int env_stack_push(struct btf_verifier_env *env, | |
1801 | const struct btf_type *t, u32 type_id) | |
1802 | { | |
951bb646 | 1803 | const struct btf *btf = env->btf; |
eb3f595d MKL |
1804 | struct resolve_vertex *v; |
1805 | ||
1806 | if (env->top_stack == MAX_RESOLVE_DEPTH) | |
1807 | return -E2BIG; | |
1808 | ||
951bb646 AN |
1809 | if (type_id < btf->start_id |
1810 | || env->visit_states[type_id - btf->start_id] != NOT_VISITED) | |
eb3f595d MKL |
1811 | return -EEXIST; |
1812 | ||
951bb646 | 1813 | env->visit_states[type_id - btf->start_id] = VISITED; |
eb3f595d MKL |
1814 | |
1815 | v = &env->stack[env->top_stack++]; | |
1816 | v->t = t; | |
1817 | v->type_id = type_id; | |
1818 | v->next_member = 0; | |
1819 | ||
1820 | if (env->resolve_mode == RESOLVE_TBD) { | |
1821 | if (btf_type_is_ptr(t)) | |
1822 | env->resolve_mode = RESOLVE_PTR; | |
1823 | else if (btf_type_is_struct(t) || btf_type_is_array(t)) | |
1824 | env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY; | |
1825 | } | |
1826 | ||
1827 | return 0; | |
1828 | } | |
1829 | ||
1830 | static void env_stack_set_next_member(struct btf_verifier_env *env, | |
1831 | u16 next_member) | |
1832 | { | |
1833 | env->stack[env->top_stack - 1].next_member = next_member; | |
1834 | } | |
1835 | ||
1836 | static void env_stack_pop_resolved(struct btf_verifier_env *env, | |
1837 | u32 resolved_type_id, | |
1838 | u32 resolved_size) | |
1839 | { | |
1840 | u32 type_id = env->stack[--(env->top_stack)].type_id; | |
1841 | struct btf *btf = env->btf; | |
1842 | ||
951bb646 | 1843 | type_id -= btf->start_id; /* adjust to local type id */ |
eb3f595d MKL |
1844 | btf->resolved_sizes[type_id] = resolved_size; |
1845 | btf->resolved_ids[type_id] = resolved_type_id; | |
1846 | env->visit_states[type_id] = RESOLVED; | |
1847 | } | |
1848 | ||
1849 | static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env) | |
1850 | { | |
1851 | return env->top_stack ? &env->stack[env->top_stack - 1] : NULL; | |
1852 | } | |
1853 | ||
7e3617a7 MKL |
1854 | /* Resolve the size of a passed-in "type" |
1855 | * | |
1856 | * type: is an array (e.g. u32 array[x][y]) | |
1857 | * return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY, | |
1858 | * *type_size: (x * y * sizeof(u32)). Hence, *type_size always | |
1859 | * corresponds to the return type. | |
1860 | * *elem_type: u32 | |
69ff3047 | 1861 | * *elem_id: id of u32 |
7e3617a7 MKL |
1862 | * *total_nelems: (x * y). Hence, individual elem size is |
1863 | * (*type_size / *total_nelems) | |
887c31a3 | 1864 | * *type_id: id of type if it's changed within the function, 0 if not |
7e3617a7 MKL |
1865 | * |
1866 | * type: is not an array (e.g. const struct X) | |
1867 | * return type: type "struct X" | |
1868 | * *type_size: sizeof(struct X) | |
1869 | * *elem_type: same as return type ("struct X") | |
69ff3047 | 1870 | * *elem_id: 0 |
7e3617a7 | 1871 | * *total_nelems: 1 |
887c31a3 | 1872 | * *type_id: id of type if it's changed within the function, 0 if not |
7e3617a7 | 1873 | */ |
6298399b JO |
1874 | static const struct btf_type * |
1875 | __btf_resolve_size(const struct btf *btf, const struct btf_type *type, | |
1876 | u32 *type_size, const struct btf_type **elem_type, | |
887c31a3 | 1877 | u32 *elem_id, u32 *total_nelems, u32 *type_id) |
7e3617a7 MKL |
1878 | { |
1879 | const struct btf_type *array_type = NULL; | |
69ff3047 | 1880 | const struct btf_array *array = NULL; |
887c31a3 | 1881 | u32 i, size, nelems = 1, id = 0; |
7e3617a7 MKL |
1882 | |
1883 | for (i = 0; i < MAX_RESOLVE_DEPTH; i++) { | |
1884 | switch (BTF_INFO_KIND(type->info)) { | |
1885 | /* type->size can be used */ | |
1886 | case BTF_KIND_INT: | |
1887 | case BTF_KIND_STRUCT: | |
1888 | case BTF_KIND_UNION: | |
1889 | case BTF_KIND_ENUM: | |
b1828f0b | 1890 | case BTF_KIND_FLOAT: |
6089fb32 | 1891 | case BTF_KIND_ENUM64: |
7e3617a7 MKL |
1892 | size = type->size; |
1893 | goto resolved; | |
1894 | ||
1895 | case BTF_KIND_PTR: | |
1896 | size = sizeof(void *); | |
1897 | goto resolved; | |
1898 | ||
1899 | /* Modifiers */ | |
1900 | case BTF_KIND_TYPEDEF: | |
1901 | case BTF_KIND_VOLATILE: | |
1902 | case BTF_KIND_CONST: | |
1903 | case BTF_KIND_RESTRICT: | |
8c42d2fa | 1904 | case BTF_KIND_TYPE_TAG: |
887c31a3 | 1905 | id = type->type; |
7e3617a7 MKL |
1906 | type = btf_type_by_id(btf, type->type); |
1907 | break; | |
1908 | ||
1909 | case BTF_KIND_ARRAY: | |
1910 | if (!array_type) | |
1911 | array_type = type; | |
1912 | array = btf_type_array(type); | |
1913 | if (nelems && array->nelems > U32_MAX / nelems) | |
1914 | return ERR_PTR(-EINVAL); | |
1915 | nelems *= array->nelems; | |
1916 | type = btf_type_by_id(btf, array->type); | |
1917 | break; | |
1918 | ||
1919 | /* type without size */ | |
1920 | default: | |
1921 | return ERR_PTR(-EINVAL); | |
1922 | } | |
1923 | } | |
1924 | ||
1925 | return ERR_PTR(-EINVAL); | |
1926 | ||
1927 | resolved: | |
1928 | if (nelems && size > U32_MAX / nelems) | |
1929 | return ERR_PTR(-EINVAL); | |
1930 | ||
1931 | *type_size = nelems * size; | |
85d33df3 MKL |
1932 | if (total_nelems) |
1933 | *total_nelems = nelems; | |
1934 | if (elem_type) | |
1935 | *elem_type = type; | |
69ff3047 JO |
1936 | if (elem_id) |
1937 | *elem_id = array ? array->type : 0; | |
887c31a3 JO |
1938 | if (type_id && id) |
1939 | *type_id = id; | |
7e3617a7 MKL |
1940 | |
1941 | return array_type ? : type; | |
1942 | } | |
1943 | ||
6298399b JO |
1944 | const struct btf_type * |
1945 | btf_resolve_size(const struct btf *btf, const struct btf_type *type, | |
1946 | u32 *type_size) | |
1947 | { | |
887c31a3 | 1948 | return __btf_resolve_size(btf, type, type_size, NULL, NULL, NULL, NULL); |
6298399b JO |
1949 | } |
1950 | ||
951bb646 AN |
1951 | static u32 btf_resolved_type_id(const struct btf *btf, u32 type_id) |
1952 | { | |
1953 | while (type_id < btf->start_id) | |
1954 | btf = btf->base_btf; | |
1955 | ||
1956 | return btf->resolved_ids[type_id - btf->start_id]; | |
1957 | } | |
1958 | ||
eb3f595d MKL |
1959 | /* The input param "type_id" must point to a needs_resolve type */ |
1960 | static const struct btf_type *btf_type_id_resolve(const struct btf *btf, | |
1961 | u32 *type_id) | |
1962 | { | |
951bb646 | 1963 | *type_id = btf_resolved_type_id(btf, *type_id); |
eb3f595d MKL |
1964 | return btf_type_by_id(btf, *type_id); |
1965 | } | |
1966 | ||
951bb646 AN |
1967 | static u32 btf_resolved_type_size(const struct btf *btf, u32 type_id) |
1968 | { | |
1969 | while (type_id < btf->start_id) | |
1970 | btf = btf->base_btf; | |
1971 | ||
1972 | return btf->resolved_sizes[type_id - btf->start_id]; | |
1973 | } | |
1974 | ||
eb3f595d MKL |
1975 | const struct btf_type *btf_type_id_size(const struct btf *btf, |
1976 | u32 *type_id, u32 *ret_size) | |
1977 | { | |
1978 | const struct btf_type *size_type; | |
1979 | u32 size_type_id = *type_id; | |
1980 | u32 size = 0; | |
1981 | ||
1982 | size_type = btf_type_by_id(btf, size_type_id); | |
b47a0bd2 | 1983 | if (btf_type_nosize_or_null(size_type)) |
eb3f595d MKL |
1984 | return NULL; |
1985 | ||
1986 | if (btf_type_has_size(size_type)) { | |
1987 | size = size_type->size; | |
1988 | } else if (btf_type_is_array(size_type)) { | |
951bb646 | 1989 | size = btf_resolved_type_size(btf, size_type_id); |
eb3f595d MKL |
1990 | } else if (btf_type_is_ptr(size_type)) { |
1991 | size = sizeof(void *); | |
1992 | } else { | |
1dc92851 DB |
1993 | if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) && |
1994 | !btf_type_is_var(size_type))) | |
eb3f595d MKL |
1995 | return NULL; |
1996 | ||
951bb646 | 1997 | size_type_id = btf_resolved_type_id(btf, size_type_id); |
eb3f595d | 1998 | size_type = btf_type_by_id(btf, size_type_id); |
b47a0bd2 | 1999 | if (btf_type_nosize_or_null(size_type)) |
eb3f595d | 2000 | return NULL; |
1acc5d5c AN |
2001 | else if (btf_type_has_size(size_type)) |
2002 | size = size_type->size; | |
2003 | else if (btf_type_is_array(size_type)) | |
951bb646 | 2004 | size = btf_resolved_type_size(btf, size_type_id); |
1acc5d5c AN |
2005 | else if (btf_type_is_ptr(size_type)) |
2006 | size = sizeof(void *); | |
2007 | else | |
2008 | return NULL; | |
eb3f595d MKL |
2009 | } |
2010 | ||
2011 | *type_id = size_type_id; | |
2012 | if (ret_size) | |
2013 | *ret_size = size; | |
2014 | ||
2015 | return size_type; | |
2016 | } | |
2017 | ||
179cde8c MKL |
2018 | static int btf_df_check_member(struct btf_verifier_env *env, |
2019 | const struct btf_type *struct_type, | |
2020 | const struct btf_member *member, | |
2021 | const struct btf_type *member_type) | |
2022 | { | |
2023 | btf_verifier_log_basic(env, struct_type, | |
2024 | "Unsupported check_member"); | |
2025 | return -EINVAL; | |
2026 | } | |
2027 | ||
9d5f9f70 YS |
2028 | static int btf_df_check_kflag_member(struct btf_verifier_env *env, |
2029 | const struct btf_type *struct_type, | |
2030 | const struct btf_member *member, | |
2031 | const struct btf_type *member_type) | |
2032 | { | |
2033 | btf_verifier_log_basic(env, struct_type, | |
2034 | "Unsupported check_kflag_member"); | |
2035 | return -EINVAL; | |
2036 | } | |
2037 | ||
b1828f0b | 2038 | /* Used for ptr, array struct/union and float type members. |
9d5f9f70 YS |
2039 | * int, enum and modifier types have their specific callback functions. |
2040 | */ | |
2041 | static int btf_generic_check_kflag_member(struct btf_verifier_env *env, | |
2042 | const struct btf_type *struct_type, | |
2043 | const struct btf_member *member, | |
2044 | const struct btf_type *member_type) | |
2045 | { | |
2046 | if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) { | |
2047 | btf_verifier_log_member(env, struct_type, member, | |
2048 | "Invalid member bitfield_size"); | |
2049 | return -EINVAL; | |
2050 | } | |
2051 | ||
2052 | /* bitfield size is 0, so member->offset represents bit offset only. | |
2053 | * It is safe to call non kflag check_member variants. | |
2054 | */ | |
2055 | return btf_type_ops(member_type)->check_member(env, struct_type, | |
2056 | member, | |
2057 | member_type); | |
2058 | } | |
2059 | ||
eb3f595d MKL |
2060 | static int btf_df_resolve(struct btf_verifier_env *env, |
2061 | const struct resolve_vertex *v) | |
2062 | { | |
2063 | btf_verifier_log_basic(env, v->t, "Unsupported resolve"); | |
2064 | return -EINVAL; | |
2065 | } | |
2066 | ||
31d0bc81 AM |
2067 | static void btf_df_show(const struct btf *btf, const struct btf_type *t, |
2068 | u32 type_id, void *data, u8 bits_offsets, | |
2069 | struct btf_show *show) | |
b00b8dae | 2070 | { |
31d0bc81 | 2071 | btf_show(show, "<unsupported kind:%u>", BTF_INFO_KIND(t->info)); |
b00b8dae MKL |
2072 | } |
2073 | ||
179cde8c MKL |
2074 | static int btf_int_check_member(struct btf_verifier_env *env, |
2075 | const struct btf_type *struct_type, | |
2076 | const struct btf_member *member, | |
2077 | const struct btf_type *member_type) | |
2078 | { | |
2079 | u32 int_data = btf_type_int(member_type); | |
2080 | u32 struct_bits_off = member->offset; | |
2081 | u32 struct_size = struct_type->size; | |
2082 | u32 nr_copy_bits; | |
2083 | u32 bytes_offset; | |
2084 | ||
2085 | if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) { | |
2086 | btf_verifier_log_member(env, struct_type, member, | |
2087 | "bits_offset exceeds U32_MAX"); | |
2088 | return -EINVAL; | |
2089 | } | |
2090 | ||
2091 | struct_bits_off += BTF_INT_OFFSET(int_data); | |
2092 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2093 | nr_copy_bits = BTF_INT_BITS(int_data) + | |
2094 | BITS_PER_BYTE_MASKED(struct_bits_off); | |
2095 | ||
b1e8818c | 2096 | if (nr_copy_bits > BITS_PER_U128) { |
179cde8c | 2097 | btf_verifier_log_member(env, struct_type, member, |
b1e8818c | 2098 | "nr_copy_bits exceeds 128"); |
179cde8c MKL |
2099 | return -EINVAL; |
2100 | } | |
2101 | ||
2102 | if (struct_size < bytes_offset || | |
2103 | struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { | |
2104 | btf_verifier_log_member(env, struct_type, member, | |
2105 | "Member exceeds struct_size"); | |
2106 | return -EINVAL; | |
2107 | } | |
2108 | ||
2109 | return 0; | |
2110 | } | |
2111 | ||
9d5f9f70 YS |
2112 | static int btf_int_check_kflag_member(struct btf_verifier_env *env, |
2113 | const struct btf_type *struct_type, | |
2114 | const struct btf_member *member, | |
2115 | const struct btf_type *member_type) | |
2116 | { | |
2117 | u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset; | |
2118 | u32 int_data = btf_type_int(member_type); | |
2119 | u32 struct_size = struct_type->size; | |
2120 | u32 nr_copy_bits; | |
2121 | ||
2122 | /* a regular int type is required for the kflag int member */ | |
2123 | if (!btf_type_int_is_regular(member_type)) { | |
2124 | btf_verifier_log_member(env, struct_type, member, | |
2125 | "Invalid member base type"); | |
2126 | return -EINVAL; | |
2127 | } | |
2128 | ||
2129 | /* check sanity of bitfield size */ | |
2130 | nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); | |
2131 | struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); | |
2132 | nr_int_data_bits = BTF_INT_BITS(int_data); | |
2133 | if (!nr_bits) { | |
2134 | /* Not a bitfield member, member offset must be at byte | |
2135 | * boundary. | |
2136 | */ | |
2137 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2138 | btf_verifier_log_member(env, struct_type, member, | |
2139 | "Invalid member offset"); | |
2140 | return -EINVAL; | |
2141 | } | |
2142 | ||
2143 | nr_bits = nr_int_data_bits; | |
2144 | } else if (nr_bits > nr_int_data_bits) { | |
2145 | btf_verifier_log_member(env, struct_type, member, | |
2146 | "Invalid member bitfield_size"); | |
2147 | return -EINVAL; | |
2148 | } | |
2149 | ||
2150 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2151 | nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off); | |
b1e8818c | 2152 | if (nr_copy_bits > BITS_PER_U128) { |
9d5f9f70 | 2153 | btf_verifier_log_member(env, struct_type, member, |
b1e8818c | 2154 | "nr_copy_bits exceeds 128"); |
9d5f9f70 YS |
2155 | return -EINVAL; |
2156 | } | |
2157 | ||
2158 | if (struct_size < bytes_offset || | |
2159 | struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { | |
2160 | btf_verifier_log_member(env, struct_type, member, | |
2161 | "Member exceeds struct_size"); | |
2162 | return -EINVAL; | |
2163 | } | |
2164 | ||
2165 | return 0; | |
2166 | } | |
2167 | ||
69b693f0 MKL |
2168 | static s32 btf_int_check_meta(struct btf_verifier_env *env, |
2169 | const struct btf_type *t, | |
2170 | u32 meta_left) | |
2171 | { | |
2172 | u32 int_data, nr_bits, meta_needed = sizeof(int_data); | |
2173 | u16 encoding; | |
2174 | ||
2175 | if (meta_left < meta_needed) { | |
2176 | btf_verifier_log_basic(env, t, | |
2177 | "meta_left:%u meta_needed:%u", | |
2178 | meta_left, meta_needed); | |
2179 | return -EINVAL; | |
2180 | } | |
2181 | ||
2182 | if (btf_type_vlen(t)) { | |
2183 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2184 | return -EINVAL; | |
2185 | } | |
2186 | ||
9d5f9f70 YS |
2187 | if (btf_type_kflag(t)) { |
2188 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2189 | return -EINVAL; | |
2190 | } | |
2191 | ||
69b693f0 | 2192 | int_data = btf_type_int(t); |
aea2f7b8 MKL |
2193 | if (int_data & ~BTF_INT_MASK) { |
2194 | btf_verifier_log_basic(env, t, "Invalid int_data:%x", | |
2195 | int_data); | |
2196 | return -EINVAL; | |
2197 | } | |
2198 | ||
69b693f0 MKL |
2199 | nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data); |
2200 | ||
b1e8818c | 2201 | if (nr_bits > BITS_PER_U128) { |
69b693f0 | 2202 | btf_verifier_log_type(env, t, "nr_bits exceeds %zu", |
b1e8818c | 2203 | BITS_PER_U128); |
69b693f0 MKL |
2204 | return -EINVAL; |
2205 | } | |
2206 | ||
2207 | if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) { | |
2208 | btf_verifier_log_type(env, t, "nr_bits exceeds type_size"); | |
2209 | return -EINVAL; | |
2210 | } | |
2211 | ||
aea2f7b8 MKL |
2212 | /* |
2213 | * Only one of the encoding bits is allowed and it | |
2214 | * should be sufficient for the pretty print purpose (i.e. decoding). | |
2215 | * Multiple bits can be allowed later if it is found | |
2216 | * to be insufficient. | |
2217 | */ | |
69b693f0 MKL |
2218 | encoding = BTF_INT_ENCODING(int_data); |
2219 | if (encoding && | |
2220 | encoding != BTF_INT_SIGNED && | |
2221 | encoding != BTF_INT_CHAR && | |
aea2f7b8 | 2222 | encoding != BTF_INT_BOOL) { |
69b693f0 MKL |
2223 | btf_verifier_log_type(env, t, "Unsupported encoding"); |
2224 | return -ENOTSUPP; | |
2225 | } | |
2226 | ||
2227 | btf_verifier_log_type(env, t, NULL); | |
2228 | ||
2229 | return meta_needed; | |
2230 | } | |
2231 | ||
2232 | static void btf_int_log(struct btf_verifier_env *env, | |
2233 | const struct btf_type *t) | |
2234 | { | |
2235 | int int_data = btf_type_int(t); | |
2236 | ||
2237 | btf_verifier_log(env, | |
2238 | "size=%u bits_offset=%u nr_bits=%u encoding=%s", | |
2239 | t->size, BTF_INT_OFFSET(int_data), | |
2240 | BTF_INT_BITS(int_data), | |
2241 | btf_int_encoding_str(BTF_INT_ENCODING(int_data))); | |
2242 | } | |
2243 | ||
31d0bc81 | 2244 | static void btf_int128_print(struct btf_show *show, void *data) |
b1e8818c YS |
2245 | { |
2246 | /* data points to a __int128 number. | |
2247 | * Suppose | |
2248 | * int128_num = *(__int128 *)data; | |
2249 | * The below formulas shows what upper_num and lower_num represents: | |
2250 | * upper_num = int128_num >> 64; | |
2251 | * lower_num = int128_num & 0xffffffffFFFFFFFFULL; | |
2252 | */ | |
2253 | u64 upper_num, lower_num; | |
2254 | ||
2255 | #ifdef __BIG_ENDIAN_BITFIELD | |
2256 | upper_num = *(u64 *)data; | |
2257 | lower_num = *(u64 *)(data + 8); | |
2258 | #else | |
2259 | upper_num = *(u64 *)(data + 8); | |
2260 | lower_num = *(u64 *)data; | |
2261 | #endif | |
2262 | if (upper_num == 0) | |
31d0bc81 | 2263 | btf_show_type_value(show, "0x%llx", lower_num); |
b1e8818c | 2264 | else |
31d0bc81 AM |
2265 | btf_show_type_values(show, "0x%llx%016llx", upper_num, |
2266 | lower_num); | |
b1e8818c YS |
2267 | } |
2268 | ||
2269 | static void btf_int128_shift(u64 *print_num, u16 left_shift_bits, | |
2270 | u16 right_shift_bits) | |
2271 | { | |
2272 | u64 upper_num, lower_num; | |
2273 | ||
2274 | #ifdef __BIG_ENDIAN_BITFIELD | |
2275 | upper_num = print_num[0]; | |
2276 | lower_num = print_num[1]; | |
2277 | #else | |
2278 | upper_num = print_num[1]; | |
2279 | lower_num = print_num[0]; | |
2280 | #endif | |
2281 | ||
2282 | /* shake out un-needed bits by shift/or operations */ | |
2283 | if (left_shift_bits >= 64) { | |
2284 | upper_num = lower_num << (left_shift_bits - 64); | |
2285 | lower_num = 0; | |
2286 | } else { | |
2287 | upper_num = (upper_num << left_shift_bits) | | |
2288 | (lower_num >> (64 - left_shift_bits)); | |
2289 | lower_num = lower_num << left_shift_bits; | |
2290 | } | |
2291 | ||
2292 | if (right_shift_bits >= 64) { | |
2293 | lower_num = upper_num >> (right_shift_bits - 64); | |
2294 | upper_num = 0; | |
2295 | } else { | |
2296 | lower_num = (lower_num >> right_shift_bits) | | |
2297 | (upper_num << (64 - right_shift_bits)); | |
2298 | upper_num = upper_num >> right_shift_bits; | |
2299 | } | |
2300 | ||
2301 | #ifdef __BIG_ENDIAN_BITFIELD | |
2302 | print_num[0] = upper_num; | |
2303 | print_num[1] = lower_num; | |
2304 | #else | |
2305 | print_num[0] = lower_num; | |
2306 | print_num[1] = upper_num; | |
2307 | #endif | |
2308 | } | |
2309 | ||
31d0bc81 AM |
2310 | static void btf_bitfield_show(void *data, u8 bits_offset, |
2311 | u8 nr_bits, struct btf_show *show) | |
b00b8dae | 2312 | { |
b65f370d | 2313 | u16 left_shift_bits, right_shift_bits; |
36fc3c8c MKL |
2314 | u8 nr_copy_bytes; |
2315 | u8 nr_copy_bits; | |
b1e8818c | 2316 | u64 print_num[2] = {}; |
b00b8dae | 2317 | |
b00b8dae MKL |
2318 | nr_copy_bits = nr_bits + bits_offset; |
2319 | nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits); | |
2320 | ||
b1e8818c | 2321 | memcpy(print_num, data, nr_copy_bytes); |
b00b8dae | 2322 | |
b65f370d OK |
2323 | #ifdef __BIG_ENDIAN_BITFIELD |
2324 | left_shift_bits = bits_offset; | |
2325 | #else | |
b1e8818c | 2326 | left_shift_bits = BITS_PER_U128 - nr_copy_bits; |
b65f370d | 2327 | #endif |
b1e8818c | 2328 | right_shift_bits = BITS_PER_U128 - nr_bits; |
b00b8dae | 2329 | |
b1e8818c | 2330 | btf_int128_shift(print_num, left_shift_bits, right_shift_bits); |
31d0bc81 | 2331 | btf_int128_print(show, print_num); |
b00b8dae MKL |
2332 | } |
2333 | ||
9d5f9f70 | 2334 | |
31d0bc81 AM |
2335 | static void btf_int_bits_show(const struct btf *btf, |
2336 | const struct btf_type *t, | |
2337 | void *data, u8 bits_offset, | |
2338 | struct btf_show *show) | |
f97be3ab YS |
2339 | { |
2340 | u32 int_data = btf_type_int(t); | |
2341 | u8 nr_bits = BTF_INT_BITS(int_data); | |
2342 | u8 total_bits_offset; | |
2343 | ||
2344 | /* | |
2345 | * bits_offset is at most 7. | |
b1e8818c | 2346 | * BTF_INT_OFFSET() cannot exceed 128 bits. |
f97be3ab YS |
2347 | */ |
2348 | total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data); | |
17e3ac81 YS |
2349 | data += BITS_ROUNDDOWN_BYTES(total_bits_offset); |
2350 | bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset); | |
31d0bc81 | 2351 | btf_bitfield_show(data, bits_offset, nr_bits, show); |
f97be3ab YS |
2352 | } |
2353 | ||
31d0bc81 AM |
2354 | static void btf_int_show(const struct btf *btf, const struct btf_type *t, |
2355 | u32 type_id, void *data, u8 bits_offset, | |
2356 | struct btf_show *show) | |
b00b8dae MKL |
2357 | { |
2358 | u32 int_data = btf_type_int(t); | |
2359 | u8 encoding = BTF_INT_ENCODING(int_data); | |
2360 | bool sign = encoding & BTF_INT_SIGNED; | |
36fc3c8c | 2361 | u8 nr_bits = BTF_INT_BITS(int_data); |
31d0bc81 AM |
2362 | void *safe_data; |
2363 | ||
2364 | safe_data = btf_show_start_type(show, t, type_id, data); | |
2365 | if (!safe_data) | |
2366 | return; | |
b00b8dae MKL |
2367 | |
2368 | if (bits_offset || BTF_INT_OFFSET(int_data) || | |
2369 | BITS_PER_BYTE_MASKED(nr_bits)) { | |
31d0bc81 AM |
2370 | btf_int_bits_show(btf, t, safe_data, bits_offset, show); |
2371 | goto out; | |
b00b8dae MKL |
2372 | } |
2373 | ||
2374 | switch (nr_bits) { | |
b1e8818c | 2375 | case 128: |
31d0bc81 | 2376 | btf_int128_print(show, safe_data); |
b1e8818c | 2377 | break; |
b00b8dae MKL |
2378 | case 64: |
2379 | if (sign) | |
31d0bc81 | 2380 | btf_show_type_value(show, "%lld", *(s64 *)safe_data); |
b00b8dae | 2381 | else |
31d0bc81 | 2382 | btf_show_type_value(show, "%llu", *(u64 *)safe_data); |
b00b8dae MKL |
2383 | break; |
2384 | case 32: | |
2385 | if (sign) | |
31d0bc81 | 2386 | btf_show_type_value(show, "%d", *(s32 *)safe_data); |
b00b8dae | 2387 | else |
31d0bc81 | 2388 | btf_show_type_value(show, "%u", *(u32 *)safe_data); |
b00b8dae MKL |
2389 | break; |
2390 | case 16: | |
2391 | if (sign) | |
31d0bc81 | 2392 | btf_show_type_value(show, "%d", *(s16 *)safe_data); |
b00b8dae | 2393 | else |
31d0bc81 | 2394 | btf_show_type_value(show, "%u", *(u16 *)safe_data); |
b00b8dae MKL |
2395 | break; |
2396 | case 8: | |
31d0bc81 AM |
2397 | if (show->state.array_encoding == BTF_INT_CHAR) { |
2398 | /* check for null terminator */ | |
2399 | if (show->state.array_terminated) | |
2400 | break; | |
2401 | if (*(char *)data == '\0') { | |
2402 | show->state.array_terminated = 1; | |
2403 | break; | |
2404 | } | |
2405 | if (isprint(*(char *)data)) { | |
2406 | btf_show_type_value(show, "'%c'", | |
2407 | *(char *)safe_data); | |
2408 | break; | |
2409 | } | |
2410 | } | |
b00b8dae | 2411 | if (sign) |
31d0bc81 | 2412 | btf_show_type_value(show, "%d", *(s8 *)safe_data); |
b00b8dae | 2413 | else |
31d0bc81 | 2414 | btf_show_type_value(show, "%u", *(u8 *)safe_data); |
b00b8dae MKL |
2415 | break; |
2416 | default: | |
31d0bc81 AM |
2417 | btf_int_bits_show(btf, t, safe_data, bits_offset, show); |
2418 | break; | |
b00b8dae | 2419 | } |
31d0bc81 AM |
2420 | out: |
2421 | btf_show_end_type(show); | |
b00b8dae MKL |
2422 | } |
2423 | ||
69b693f0 MKL |
2424 | static const struct btf_kind_operations int_ops = { |
2425 | .check_meta = btf_int_check_meta, | |
eb3f595d | 2426 | .resolve = btf_df_resolve, |
179cde8c | 2427 | .check_member = btf_int_check_member, |
9d5f9f70 | 2428 | .check_kflag_member = btf_int_check_kflag_member, |
69b693f0 | 2429 | .log_details = btf_int_log, |
31d0bc81 | 2430 | .show = btf_int_show, |
69b693f0 MKL |
2431 | }; |
2432 | ||
179cde8c MKL |
2433 | static int btf_modifier_check_member(struct btf_verifier_env *env, |
2434 | const struct btf_type *struct_type, | |
2435 | const struct btf_member *member, | |
2436 | const struct btf_type *member_type) | |
2437 | { | |
2438 | const struct btf_type *resolved_type; | |
2439 | u32 resolved_type_id = member->type; | |
2440 | struct btf_member resolved_member; | |
2441 | struct btf *btf = env->btf; | |
2442 | ||
2443 | resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); | |
2444 | if (!resolved_type) { | |
2445 | btf_verifier_log_member(env, struct_type, member, | |
2446 | "Invalid member"); | |
2447 | return -EINVAL; | |
2448 | } | |
2449 | ||
2450 | resolved_member = *member; | |
2451 | resolved_member.type = resolved_type_id; | |
2452 | ||
2453 | return btf_type_ops(resolved_type)->check_member(env, struct_type, | |
2454 | &resolved_member, | |
2455 | resolved_type); | |
2456 | } | |
2457 | ||
9d5f9f70 YS |
2458 | static int btf_modifier_check_kflag_member(struct btf_verifier_env *env, |
2459 | const struct btf_type *struct_type, | |
2460 | const struct btf_member *member, | |
2461 | const struct btf_type *member_type) | |
2462 | { | |
2463 | const struct btf_type *resolved_type; | |
2464 | u32 resolved_type_id = member->type; | |
2465 | struct btf_member resolved_member; | |
2466 | struct btf *btf = env->btf; | |
2467 | ||
2468 | resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); | |
2469 | if (!resolved_type) { | |
2470 | btf_verifier_log_member(env, struct_type, member, | |
2471 | "Invalid member"); | |
2472 | return -EINVAL; | |
2473 | } | |
2474 | ||
2475 | resolved_member = *member; | |
2476 | resolved_member.type = resolved_type_id; | |
2477 | ||
2478 | return btf_type_ops(resolved_type)->check_kflag_member(env, struct_type, | |
2479 | &resolved_member, | |
2480 | resolved_type); | |
2481 | } | |
2482 | ||
179cde8c MKL |
2483 | static int btf_ptr_check_member(struct btf_verifier_env *env, |
2484 | const struct btf_type *struct_type, | |
2485 | const struct btf_member *member, | |
2486 | const struct btf_type *member_type) | |
2487 | { | |
2488 | u32 struct_size, struct_bits_off, bytes_offset; | |
2489 | ||
2490 | struct_size = struct_type->size; | |
2491 | struct_bits_off = member->offset; | |
2492 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2493 | ||
2494 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2495 | btf_verifier_log_member(env, struct_type, member, | |
2496 | "Member is not byte aligned"); | |
2497 | return -EINVAL; | |
2498 | } | |
2499 | ||
2500 | if (struct_size - bytes_offset < sizeof(void *)) { | |
2501 | btf_verifier_log_member(env, struct_type, member, | |
2502 | "Member exceeds struct_size"); | |
2503 | return -EINVAL; | |
2504 | } | |
2505 | ||
2506 | return 0; | |
2507 | } | |
2508 | ||
69b693f0 MKL |
2509 | static int btf_ref_type_check_meta(struct btf_verifier_env *env, |
2510 | const struct btf_type *t, | |
2511 | u32 meta_left) | |
2512 | { | |
8c42d2fa YS |
2513 | const char *value; |
2514 | ||
69b693f0 MKL |
2515 | if (btf_type_vlen(t)) { |
2516 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2517 | return -EINVAL; | |
2518 | } | |
2519 | ||
9d5f9f70 YS |
2520 | if (btf_type_kflag(t)) { |
2521 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2522 | return -EINVAL; | |
2523 | } | |
2524 | ||
aea2f7b8 | 2525 | if (!BTF_TYPE_ID_VALID(t->type)) { |
69b693f0 MKL |
2526 | btf_verifier_log_type(env, t, "Invalid type_id"); |
2527 | return -EINVAL; | |
2528 | } | |
2529 | ||
8c42d2fa | 2530 | /* typedef/type_tag type must have a valid name, and other ref types, |
eb04bbb6 YS |
2531 | * volatile, const, restrict, should have a null name. |
2532 | */ | |
2533 | if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) { | |
2534 | if (!t->name_off || | |
2535 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
2536 | btf_verifier_log_type(env, t, "Invalid name"); | |
2537 | return -EINVAL; | |
2538 | } | |
8c42d2fa YS |
2539 | } else if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPE_TAG) { |
2540 | value = btf_name_by_offset(env->btf, t->name_off); | |
2541 | if (!value || !value[0]) { | |
2542 | btf_verifier_log_type(env, t, "Invalid name"); | |
2543 | return -EINVAL; | |
2544 | } | |
eb04bbb6 YS |
2545 | } else { |
2546 | if (t->name_off) { | |
2547 | btf_verifier_log_type(env, t, "Invalid name"); | |
2548 | return -EINVAL; | |
2549 | } | |
2550 | } | |
2551 | ||
69b693f0 MKL |
2552 | btf_verifier_log_type(env, t, NULL); |
2553 | ||
2554 | return 0; | |
2555 | } | |
2556 | ||
eb3f595d MKL |
2557 | static int btf_modifier_resolve(struct btf_verifier_env *env, |
2558 | const struct resolve_vertex *v) | |
2559 | { | |
2560 | const struct btf_type *t = v->t; | |
2561 | const struct btf_type *next_type; | |
2562 | u32 next_type_id = t->type; | |
2563 | struct btf *btf = env->btf; | |
eb3f595d MKL |
2564 | |
2565 | next_type = btf_type_by_id(btf, next_type_id); | |
1dc92851 | 2566 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
eb3f595d MKL |
2567 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2568 | return -EINVAL; | |
2569 | } | |
2570 | ||
eb3f595d MKL |
2571 | if (!env_type_is_resolve_sink(env, next_type) && |
2572 | !env_type_is_resolved(env, next_type_id)) | |
2573 | return env_stack_push(env, next_type, next_type_id); | |
2574 | ||
2575 | /* Figure out the resolved next_type_id with size. | |
2576 | * They will be stored in the current modifier's | |
2577 | * resolved_ids and resolved_sizes such that it can | |
2578 | * save us a few type-following when we use it later (e.g. in | |
2579 | * pretty print). | |
2580 | */ | |
1acc5d5c | 2581 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
2667a262 MKL |
2582 | if (env_type_is_resolved(env, next_type_id)) |
2583 | next_type = btf_type_id_resolve(btf, &next_type_id); | |
2584 | ||
2585 | /* "typedef void new_void", "const void"...etc */ | |
2586 | if (!btf_type_is_void(next_type) && | |
81f5c6f5 YS |
2587 | !btf_type_is_fwd(next_type) && |
2588 | !btf_type_is_func_proto(next_type)) { | |
2667a262 MKL |
2589 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2590 | return -EINVAL; | |
2591 | } | |
eb3f595d MKL |
2592 | } |
2593 | ||
1acc5d5c | 2594 | env_stack_pop_resolved(env, next_type_id, 0); |
eb3f595d MKL |
2595 | |
2596 | return 0; | |
2597 | } | |
2598 | ||
1dc92851 DB |
2599 | static int btf_var_resolve(struct btf_verifier_env *env, |
2600 | const struct resolve_vertex *v) | |
2601 | { | |
2602 | const struct btf_type *next_type; | |
2603 | const struct btf_type *t = v->t; | |
2604 | u32 next_type_id = t->type; | |
2605 | struct btf *btf = env->btf; | |
1dc92851 DB |
2606 | |
2607 | next_type = btf_type_by_id(btf, next_type_id); | |
2608 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { | |
2609 | btf_verifier_log_type(env, v->t, "Invalid type_id"); | |
2610 | return -EINVAL; | |
2611 | } | |
2612 | ||
2613 | if (!env_type_is_resolve_sink(env, next_type) && | |
2614 | !env_type_is_resolved(env, next_type_id)) | |
2615 | return env_stack_push(env, next_type, next_type_id); | |
2616 | ||
2617 | if (btf_type_is_modifier(next_type)) { | |
2618 | const struct btf_type *resolved_type; | |
2619 | u32 resolved_type_id; | |
2620 | ||
2621 | resolved_type_id = next_type_id; | |
2622 | resolved_type = btf_type_id_resolve(btf, &resolved_type_id); | |
2623 | ||
2624 | if (btf_type_is_ptr(resolved_type) && | |
2625 | !env_type_is_resolve_sink(env, resolved_type) && | |
2626 | !env_type_is_resolved(env, resolved_type_id)) | |
2627 | return env_stack_push(env, resolved_type, | |
2628 | resolved_type_id); | |
2629 | } | |
2630 | ||
2631 | /* We must resolve to something concrete at this point, no | |
2632 | * forward types or similar that would resolve to size of | |
2633 | * zero is allowed. | |
2634 | */ | |
1acc5d5c | 2635 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
1dc92851 DB |
2636 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2637 | return -EINVAL; | |
2638 | } | |
2639 | ||
1acc5d5c | 2640 | env_stack_pop_resolved(env, next_type_id, 0); |
1dc92851 DB |
2641 | |
2642 | return 0; | |
2643 | } | |
2644 | ||
eb3f595d MKL |
2645 | static int btf_ptr_resolve(struct btf_verifier_env *env, |
2646 | const struct resolve_vertex *v) | |
2647 | { | |
2648 | const struct btf_type *next_type; | |
2649 | const struct btf_type *t = v->t; | |
2650 | u32 next_type_id = t->type; | |
2651 | struct btf *btf = env->btf; | |
eb3f595d MKL |
2652 | |
2653 | next_type = btf_type_by_id(btf, next_type_id); | |
1dc92851 | 2654 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
eb3f595d MKL |
2655 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2656 | return -EINVAL; | |
2657 | } | |
2658 | ||
eb3f595d MKL |
2659 | if (!env_type_is_resolve_sink(env, next_type) && |
2660 | !env_type_is_resolved(env, next_type_id)) | |
2661 | return env_stack_push(env, next_type, next_type_id); | |
2662 | ||
2663 | /* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY, | |
2664 | * the modifier may have stopped resolving when it was resolved | |
2665 | * to a ptr (last-resolved-ptr). | |
2666 | * | |
2667 | * We now need to continue from the last-resolved-ptr to | |
2668 | * ensure the last-resolved-ptr will not referring back to | |
c561d110 | 2669 | * the current ptr (t). |
eb3f595d MKL |
2670 | */ |
2671 | if (btf_type_is_modifier(next_type)) { | |
2672 | const struct btf_type *resolved_type; | |
2673 | u32 resolved_type_id; | |
2674 | ||
2675 | resolved_type_id = next_type_id; | |
2676 | resolved_type = btf_type_id_resolve(btf, &resolved_type_id); | |
2677 | ||
2678 | if (btf_type_is_ptr(resolved_type) && | |
2679 | !env_type_is_resolve_sink(env, resolved_type) && | |
2680 | !env_type_is_resolved(env, resolved_type_id)) | |
2681 | return env_stack_push(env, resolved_type, | |
2682 | resolved_type_id); | |
2683 | } | |
2684 | ||
2667a262 MKL |
2685 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
2686 | if (env_type_is_resolved(env, next_type_id)) | |
2687 | next_type = btf_type_id_resolve(btf, &next_type_id); | |
2688 | ||
2689 | if (!btf_type_is_void(next_type) && | |
2690 | !btf_type_is_fwd(next_type) && | |
2691 | !btf_type_is_func_proto(next_type)) { | |
2692 | btf_verifier_log_type(env, v->t, "Invalid type_id"); | |
2693 | return -EINVAL; | |
2694 | } | |
eb3f595d MKL |
2695 | } |
2696 | ||
eb3f595d MKL |
2697 | env_stack_pop_resolved(env, next_type_id, 0); |
2698 | ||
2699 | return 0; | |
2700 | } | |
2701 | ||
31d0bc81 AM |
2702 | static void btf_modifier_show(const struct btf *btf, |
2703 | const struct btf_type *t, | |
2704 | u32 type_id, void *data, | |
2705 | u8 bits_offset, struct btf_show *show) | |
b00b8dae | 2706 | { |
85d33df3 MKL |
2707 | if (btf->resolved_ids) |
2708 | t = btf_type_id_resolve(btf, &type_id); | |
2709 | else | |
2710 | t = btf_type_skip_modifiers(btf, type_id, NULL); | |
b00b8dae | 2711 | |
31d0bc81 | 2712 | btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show); |
b00b8dae MKL |
2713 | } |
2714 | ||
31d0bc81 AM |
2715 | static void btf_var_show(const struct btf *btf, const struct btf_type *t, |
2716 | u32 type_id, void *data, u8 bits_offset, | |
2717 | struct btf_show *show) | |
1dc92851 DB |
2718 | { |
2719 | t = btf_type_id_resolve(btf, &type_id); | |
2720 | ||
31d0bc81 | 2721 | btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show); |
1dc92851 DB |
2722 | } |
2723 | ||
31d0bc81 AM |
2724 | static void btf_ptr_show(const struct btf *btf, const struct btf_type *t, |
2725 | u32 type_id, void *data, u8 bits_offset, | |
2726 | struct btf_show *show) | |
b00b8dae | 2727 | { |
31d0bc81 AM |
2728 | void *safe_data; |
2729 | ||
2730 | safe_data = btf_show_start_type(show, t, type_id, data); | |
2731 | if (!safe_data) | |
2732 | return; | |
2733 | ||
2734 | /* It is a hashed value unless BTF_SHOW_PTR_RAW is specified */ | |
2735 | if (show->flags & BTF_SHOW_PTR_RAW) | |
2736 | btf_show_type_value(show, "0x%px", *(void **)safe_data); | |
2737 | else | |
2738 | btf_show_type_value(show, "0x%p", *(void **)safe_data); | |
2739 | btf_show_end_type(show); | |
b00b8dae MKL |
2740 | } |
2741 | ||
69b693f0 MKL |
2742 | static void btf_ref_type_log(struct btf_verifier_env *env, |
2743 | const struct btf_type *t) | |
2744 | { | |
2745 | btf_verifier_log(env, "type_id=%u", t->type); | |
2746 | } | |
2747 | ||
2748 | static struct btf_kind_operations modifier_ops = { | |
2749 | .check_meta = btf_ref_type_check_meta, | |
eb3f595d | 2750 | .resolve = btf_modifier_resolve, |
179cde8c | 2751 | .check_member = btf_modifier_check_member, |
9d5f9f70 | 2752 | .check_kflag_member = btf_modifier_check_kflag_member, |
69b693f0 | 2753 | .log_details = btf_ref_type_log, |
31d0bc81 | 2754 | .show = btf_modifier_show, |
69b693f0 MKL |
2755 | }; |
2756 | ||
2757 | static struct btf_kind_operations ptr_ops = { | |
2758 | .check_meta = btf_ref_type_check_meta, | |
eb3f595d | 2759 | .resolve = btf_ptr_resolve, |
179cde8c | 2760 | .check_member = btf_ptr_check_member, |
9d5f9f70 | 2761 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 2762 | .log_details = btf_ref_type_log, |
31d0bc81 | 2763 | .show = btf_ptr_show, |
69b693f0 MKL |
2764 | }; |
2765 | ||
8175383f MKL |
2766 | static s32 btf_fwd_check_meta(struct btf_verifier_env *env, |
2767 | const struct btf_type *t, | |
2768 | u32 meta_left) | |
2769 | { | |
2770 | if (btf_type_vlen(t)) { | |
2771 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2772 | return -EINVAL; | |
2773 | } | |
2774 | ||
2775 | if (t->type) { | |
2776 | btf_verifier_log_type(env, t, "type != 0"); | |
2777 | return -EINVAL; | |
2778 | } | |
2779 | ||
eb04bbb6 YS |
2780 | /* fwd type must have a valid name */ |
2781 | if (!t->name_off || | |
2782 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
2783 | btf_verifier_log_type(env, t, "Invalid name"); | |
2784 | return -EINVAL; | |
2785 | } | |
2786 | ||
8175383f MKL |
2787 | btf_verifier_log_type(env, t, NULL); |
2788 | ||
2789 | return 0; | |
2790 | } | |
2791 | ||
76c43ae8 YS |
2792 | static void btf_fwd_type_log(struct btf_verifier_env *env, |
2793 | const struct btf_type *t) | |
2794 | { | |
2795 | btf_verifier_log(env, "%s", btf_type_kflag(t) ? "union" : "struct"); | |
2796 | } | |
2797 | ||
69b693f0 | 2798 | static struct btf_kind_operations fwd_ops = { |
8175383f | 2799 | .check_meta = btf_fwd_check_meta, |
eb3f595d | 2800 | .resolve = btf_df_resolve, |
179cde8c | 2801 | .check_member = btf_df_check_member, |
9d5f9f70 | 2802 | .check_kflag_member = btf_df_check_kflag_member, |
76c43ae8 | 2803 | .log_details = btf_fwd_type_log, |
31d0bc81 | 2804 | .show = btf_df_show, |
69b693f0 MKL |
2805 | }; |
2806 | ||
179cde8c MKL |
2807 | static int btf_array_check_member(struct btf_verifier_env *env, |
2808 | const struct btf_type *struct_type, | |
2809 | const struct btf_member *member, | |
2810 | const struct btf_type *member_type) | |
2811 | { | |
2812 | u32 struct_bits_off = member->offset; | |
2813 | u32 struct_size, bytes_offset; | |
2814 | u32 array_type_id, array_size; | |
2815 | struct btf *btf = env->btf; | |
2816 | ||
2817 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2818 | btf_verifier_log_member(env, struct_type, member, | |
2819 | "Member is not byte aligned"); | |
2820 | return -EINVAL; | |
2821 | } | |
2822 | ||
2823 | array_type_id = member->type; | |
2824 | btf_type_id_size(btf, &array_type_id, &array_size); | |
2825 | struct_size = struct_type->size; | |
2826 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2827 | if (struct_size - bytes_offset < array_size) { | |
2828 | btf_verifier_log_member(env, struct_type, member, | |
2829 | "Member exceeds struct_size"); | |
2830 | return -EINVAL; | |
2831 | } | |
2832 | ||
2833 | return 0; | |
2834 | } | |
2835 | ||
69b693f0 MKL |
2836 | static s32 btf_array_check_meta(struct btf_verifier_env *env, |
2837 | const struct btf_type *t, | |
2838 | u32 meta_left) | |
2839 | { | |
2840 | const struct btf_array *array = btf_type_array(t); | |
2841 | u32 meta_needed = sizeof(*array); | |
2842 | ||
2843 | if (meta_left < meta_needed) { | |
2844 | btf_verifier_log_basic(env, t, | |
2845 | "meta_left:%u meta_needed:%u", | |
2846 | meta_left, meta_needed); | |
2847 | return -EINVAL; | |
2848 | } | |
2849 | ||
eb04bbb6 YS |
2850 | /* array type should not have a name */ |
2851 | if (t->name_off) { | |
2852 | btf_verifier_log_type(env, t, "Invalid name"); | |
2853 | return -EINVAL; | |
2854 | } | |
2855 | ||
69b693f0 MKL |
2856 | if (btf_type_vlen(t)) { |
2857 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2858 | return -EINVAL; | |
2859 | } | |
2860 | ||
9d5f9f70 YS |
2861 | if (btf_type_kflag(t)) { |
2862 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2863 | return -EINVAL; | |
2864 | } | |
2865 | ||
b9308ae6 MKL |
2866 | if (t->size) { |
2867 | btf_verifier_log_type(env, t, "size != 0"); | |
2868 | return -EINVAL; | |
2869 | } | |
2870 | ||
4ef5f574 MKL |
2871 | /* Array elem type and index type cannot be in type void, |
2872 | * so !array->type and !array->index_type are not allowed. | |
69b693f0 | 2873 | */ |
aea2f7b8 | 2874 | if (!array->type || !BTF_TYPE_ID_VALID(array->type)) { |
4ef5f574 MKL |
2875 | btf_verifier_log_type(env, t, "Invalid elem"); |
2876 | return -EINVAL; | |
2877 | } | |
2878 | ||
aea2f7b8 | 2879 | if (!array->index_type || !BTF_TYPE_ID_VALID(array->index_type)) { |
4ef5f574 | 2880 | btf_verifier_log_type(env, t, "Invalid index"); |
69b693f0 MKL |
2881 | return -EINVAL; |
2882 | } | |
2883 | ||
2884 | btf_verifier_log_type(env, t, NULL); | |
2885 | ||
2886 | return meta_needed; | |
2887 | } | |
2888 | ||
eb3f595d MKL |
2889 | static int btf_array_resolve(struct btf_verifier_env *env, |
2890 | const struct resolve_vertex *v) | |
2891 | { | |
2892 | const struct btf_array *array = btf_type_array(v->t); | |
4ef5f574 MKL |
2893 | const struct btf_type *elem_type, *index_type; |
2894 | u32 elem_type_id, index_type_id; | |
eb3f595d MKL |
2895 | struct btf *btf = env->btf; |
2896 | u32 elem_size; | |
2897 | ||
4ef5f574 MKL |
2898 | /* Check array->index_type */ |
2899 | index_type_id = array->index_type; | |
2900 | index_type = btf_type_by_id(btf, index_type_id); | |
e4f07120 SF |
2901 | if (btf_type_nosize_or_null(index_type) || |
2902 | btf_type_is_resolve_source_only(index_type)) { | |
4ef5f574 MKL |
2903 | btf_verifier_log_type(env, v->t, "Invalid index"); |
2904 | return -EINVAL; | |
2905 | } | |
2906 | ||
2907 | if (!env_type_is_resolve_sink(env, index_type) && | |
2908 | !env_type_is_resolved(env, index_type_id)) | |
2909 | return env_stack_push(env, index_type, index_type_id); | |
2910 | ||
2911 | index_type = btf_type_id_size(btf, &index_type_id, NULL); | |
2912 | if (!index_type || !btf_type_is_int(index_type) || | |
2913 | !btf_type_int_is_regular(index_type)) { | |
2914 | btf_verifier_log_type(env, v->t, "Invalid index"); | |
2915 | return -EINVAL; | |
2916 | } | |
2917 | ||
2918 | /* Check array->type */ | |
2919 | elem_type_id = array->type; | |
eb3f595d | 2920 | elem_type = btf_type_by_id(btf, elem_type_id); |
e4f07120 SF |
2921 | if (btf_type_nosize_or_null(elem_type) || |
2922 | btf_type_is_resolve_source_only(elem_type)) { | |
eb3f595d MKL |
2923 | btf_verifier_log_type(env, v->t, |
2924 | "Invalid elem"); | |
2925 | return -EINVAL; | |
2926 | } | |
2927 | ||
2928 | if (!env_type_is_resolve_sink(env, elem_type) && | |
2929 | !env_type_is_resolved(env, elem_type_id)) | |
2930 | return env_stack_push(env, elem_type, elem_type_id); | |
2931 | ||
2932 | elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); | |
2933 | if (!elem_type) { | |
2934 | btf_verifier_log_type(env, v->t, "Invalid elem"); | |
2935 | return -EINVAL; | |
2936 | } | |
2937 | ||
4ef5f574 MKL |
2938 | if (btf_type_is_int(elem_type) && !btf_type_int_is_regular(elem_type)) { |
2939 | btf_verifier_log_type(env, v->t, "Invalid array of int"); | |
2940 | return -EINVAL; | |
eb3f595d MKL |
2941 | } |
2942 | ||
2943 | if (array->nelems && elem_size > U32_MAX / array->nelems) { | |
2944 | btf_verifier_log_type(env, v->t, | |
2945 | "Array size overflows U32_MAX"); | |
2946 | return -EINVAL; | |
2947 | } | |
2948 | ||
2949 | env_stack_pop_resolved(env, elem_type_id, elem_size * array->nelems); | |
2950 | ||
2951 | return 0; | |
2952 | } | |
2953 | ||
69b693f0 MKL |
2954 | static void btf_array_log(struct btf_verifier_env *env, |
2955 | const struct btf_type *t) | |
2956 | { | |
2957 | const struct btf_array *array = btf_type_array(t); | |
2958 | ||
2959 | btf_verifier_log(env, "type_id=%u index_type_id=%u nr_elems=%u", | |
2960 | array->type, array->index_type, array->nelems); | |
2961 | } | |
2962 | ||
31d0bc81 AM |
2963 | static void __btf_array_show(const struct btf *btf, const struct btf_type *t, |
2964 | u32 type_id, void *data, u8 bits_offset, | |
2965 | struct btf_show *show) | |
b00b8dae MKL |
2966 | { |
2967 | const struct btf_array *array = btf_type_array(t); | |
2968 | const struct btf_kind_operations *elem_ops; | |
2969 | const struct btf_type *elem_type; | |
31d0bc81 AM |
2970 | u32 i, elem_size = 0, elem_type_id; |
2971 | u16 encoding = 0; | |
b00b8dae MKL |
2972 | |
2973 | elem_type_id = array->type; | |
31d0bc81 AM |
2974 | elem_type = btf_type_skip_modifiers(btf, elem_type_id, NULL); |
2975 | if (elem_type && btf_type_has_size(elem_type)) | |
2976 | elem_size = elem_type->size; | |
2977 | ||
2978 | if (elem_type && btf_type_is_int(elem_type)) { | |
2979 | u32 int_type = btf_type_int(elem_type); | |
2980 | ||
2981 | encoding = BTF_INT_ENCODING(int_type); | |
2982 | ||
2983 | /* | |
2984 | * BTF_INT_CHAR encoding never seems to be set for | |
2985 | * char arrays, so if size is 1 and element is | |
2986 | * printable as a char, we'll do that. | |
2987 | */ | |
2988 | if (elem_size == 1) | |
2989 | encoding = BTF_INT_CHAR; | |
2990 | } | |
2991 | ||
2992 | if (!btf_show_start_array_type(show, t, type_id, encoding, data)) | |
2993 | return; | |
2994 | ||
2995 | if (!elem_type) | |
2996 | goto out; | |
b00b8dae | 2997 | elem_ops = btf_type_ops(elem_type); |
31d0bc81 | 2998 | |
b00b8dae | 2999 | for (i = 0; i < array->nelems; i++) { |
b00b8dae | 3000 | |
31d0bc81 AM |
3001 | btf_show_start_array_member(show); |
3002 | ||
3003 | elem_ops->show(btf, elem_type, elem_type_id, data, | |
3004 | bits_offset, show); | |
b00b8dae | 3005 | data += elem_size; |
31d0bc81 AM |
3006 | |
3007 | btf_show_end_array_member(show); | |
3008 | ||
3009 | if (show->state.array_terminated) | |
3010 | break; | |
b00b8dae | 3011 | } |
31d0bc81 AM |
3012 | out: |
3013 | btf_show_end_array_type(show); | |
3014 | } | |
3015 | ||
3016 | static void btf_array_show(const struct btf *btf, const struct btf_type *t, | |
3017 | u32 type_id, void *data, u8 bits_offset, | |
3018 | struct btf_show *show) | |
3019 | { | |
3020 | const struct btf_member *m = show->state.member; | |
3021 | ||
3022 | /* | |
3023 | * First check if any members would be shown (are non-zero). | |
3024 | * See comments above "struct btf_show" definition for more | |
3025 | * details on how this works at a high-level. | |
3026 | */ | |
3027 | if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) { | |
3028 | if (!show->state.depth_check) { | |
3029 | show->state.depth_check = show->state.depth + 1; | |
3030 | show->state.depth_to_show = 0; | |
3031 | } | |
3032 | __btf_array_show(btf, t, type_id, data, bits_offset, show); | |
3033 | show->state.member = m; | |
3034 | ||
3035 | if (show->state.depth_check != show->state.depth + 1) | |
3036 | return; | |
3037 | show->state.depth_check = 0; | |
3038 | ||
3039 | if (show->state.depth_to_show <= show->state.depth) | |
3040 | return; | |
3041 | /* | |
3042 | * Reaching here indicates we have recursed and found | |
3043 | * non-zero array member(s). | |
3044 | */ | |
3045 | } | |
3046 | __btf_array_show(btf, t, type_id, data, bits_offset, show); | |
b00b8dae MKL |
3047 | } |
3048 | ||
69b693f0 MKL |
3049 | static struct btf_kind_operations array_ops = { |
3050 | .check_meta = btf_array_check_meta, | |
eb3f595d | 3051 | .resolve = btf_array_resolve, |
179cde8c | 3052 | .check_member = btf_array_check_member, |
9d5f9f70 | 3053 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 3054 | .log_details = btf_array_log, |
31d0bc81 | 3055 | .show = btf_array_show, |
69b693f0 MKL |
3056 | }; |
3057 | ||
179cde8c MKL |
3058 | static int btf_struct_check_member(struct btf_verifier_env *env, |
3059 | const struct btf_type *struct_type, | |
3060 | const struct btf_member *member, | |
3061 | const struct btf_type *member_type) | |
3062 | { | |
3063 | u32 struct_bits_off = member->offset; | |
3064 | u32 struct_size, bytes_offset; | |
3065 | ||
3066 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
3067 | btf_verifier_log_member(env, struct_type, member, | |
3068 | "Member is not byte aligned"); | |
3069 | return -EINVAL; | |
3070 | } | |
3071 | ||
3072 | struct_size = struct_type->size; | |
3073 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
3074 | if (struct_size - bytes_offset < member_type->size) { | |
3075 | btf_verifier_log_member(env, struct_type, member, | |
3076 | "Member exceeds struct_size"); | |
3077 | return -EINVAL; | |
3078 | } | |
3079 | ||
3080 | return 0; | |
3081 | } | |
3082 | ||
69b693f0 MKL |
3083 | static s32 btf_struct_check_meta(struct btf_verifier_env *env, |
3084 | const struct btf_type *t, | |
3085 | u32 meta_left) | |
3086 | { | |
3087 | bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION; | |
3088 | const struct btf_member *member; | |
6283fa38 | 3089 | u32 meta_needed, last_offset; |
69b693f0 MKL |
3090 | struct btf *btf = env->btf; |
3091 | u32 struct_size = t->size; | |
9d5f9f70 | 3092 | u32 offset; |
69b693f0 MKL |
3093 | u16 i; |
3094 | ||
3095 | meta_needed = btf_type_vlen(t) * sizeof(*member); | |
3096 | if (meta_left < meta_needed) { | |
3097 | btf_verifier_log_basic(env, t, | |
3098 | "meta_left:%u meta_needed:%u", | |
3099 | meta_left, meta_needed); | |
3100 | return -EINVAL; | |
3101 | } | |
3102 | ||
eb04bbb6 YS |
3103 | /* struct type either no name or a valid one */ |
3104 | if (t->name_off && | |
3105 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
3106 | btf_verifier_log_type(env, t, "Invalid name"); | |
3107 | return -EINVAL; | |
3108 | } | |
3109 | ||
69b693f0 MKL |
3110 | btf_verifier_log_type(env, t, NULL); |
3111 | ||
6283fa38 | 3112 | last_offset = 0; |
69b693f0 | 3113 | for_each_member(i, t, member) { |
fbcf93eb | 3114 | if (!btf_name_offset_valid(btf, member->name_off)) { |
69b693f0 MKL |
3115 | btf_verifier_log_member(env, t, member, |
3116 | "Invalid member name_offset:%u", | |
fbcf93eb | 3117 | member->name_off); |
69b693f0 MKL |
3118 | return -EINVAL; |
3119 | } | |
3120 | ||
eb04bbb6 YS |
3121 | /* struct member either no name or a valid one */ |
3122 | if (member->name_off && | |
3123 | !btf_name_valid_identifier(btf, member->name_off)) { | |
3124 | btf_verifier_log_member(env, t, member, "Invalid name"); | |
3125 | return -EINVAL; | |
3126 | } | |
69b693f0 | 3127 | /* A member cannot be in type void */ |
aea2f7b8 | 3128 | if (!member->type || !BTF_TYPE_ID_VALID(member->type)) { |
69b693f0 MKL |
3129 | btf_verifier_log_member(env, t, member, |
3130 | "Invalid type_id"); | |
3131 | return -EINVAL; | |
3132 | } | |
3133 | ||
8293eb99 | 3134 | offset = __btf_member_bit_offset(t, member); |
9d5f9f70 | 3135 | if (is_union && offset) { |
69b693f0 MKL |
3136 | btf_verifier_log_member(env, t, member, |
3137 | "Invalid member bits_offset"); | |
3138 | return -EINVAL; | |
3139 | } | |
3140 | ||
6283fa38 MKL |
3141 | /* |
3142 | * ">" instead of ">=" because the last member could be | |
3143 | * "char a[0];" | |
3144 | */ | |
9d5f9f70 | 3145 | if (last_offset > offset) { |
6283fa38 MKL |
3146 | btf_verifier_log_member(env, t, member, |
3147 | "Invalid member bits_offset"); | |
3148 | return -EINVAL; | |
3149 | } | |
3150 | ||
9d5f9f70 | 3151 | if (BITS_ROUNDUP_BYTES(offset) > struct_size) { |
69b693f0 | 3152 | btf_verifier_log_member(env, t, member, |
311fe1a8 | 3153 | "Member bits_offset exceeds its struct size"); |
69b693f0 MKL |
3154 | return -EINVAL; |
3155 | } | |
3156 | ||
3157 | btf_verifier_log_member(env, t, member, NULL); | |
9d5f9f70 | 3158 | last_offset = offset; |
69b693f0 MKL |
3159 | } |
3160 | ||
3161 | return meta_needed; | |
3162 | } | |
3163 | ||
eb3f595d MKL |
3164 | static int btf_struct_resolve(struct btf_verifier_env *env, |
3165 | const struct resolve_vertex *v) | |
3166 | { | |
3167 | const struct btf_member *member; | |
179cde8c | 3168 | int err; |
eb3f595d MKL |
3169 | u16 i; |
3170 | ||
3171 | /* Before continue resolving the next_member, | |
3172 | * ensure the last member is indeed resolved to a | |
3173 | * type with size info. | |
3174 | */ | |
3175 | if (v->next_member) { | |
179cde8c | 3176 | const struct btf_type *last_member_type; |
eb3f595d | 3177 | const struct btf_member *last_member; |
a37a3258 | 3178 | u32 last_member_type_id; |
eb3f595d MKL |
3179 | |
3180 | last_member = btf_type_member(v->t) + v->next_member - 1; | |
3181 | last_member_type_id = last_member->type; | |
3182 | if (WARN_ON_ONCE(!env_type_is_resolved(env, | |
3183 | last_member_type_id))) | |
3184 | return -EINVAL; | |
179cde8c MKL |
3185 | |
3186 | last_member_type = btf_type_by_id(env->btf, | |
3187 | last_member_type_id); | |
9d5f9f70 YS |
3188 | if (btf_type_kflag(v->t)) |
3189 | err = btf_type_ops(last_member_type)->check_kflag_member(env, v->t, | |
3190 | last_member, | |
3191 | last_member_type); | |
3192 | else | |
3193 | err = btf_type_ops(last_member_type)->check_member(env, v->t, | |
3194 | last_member, | |
3195 | last_member_type); | |
179cde8c MKL |
3196 | if (err) |
3197 | return err; | |
eb3f595d MKL |
3198 | } |
3199 | ||
3200 | for_each_member_from(i, v->next_member, v->t, member) { | |
3201 | u32 member_type_id = member->type; | |
3202 | const struct btf_type *member_type = btf_type_by_id(env->btf, | |
3203 | member_type_id); | |
3204 | ||
e4f07120 SF |
3205 | if (btf_type_nosize_or_null(member_type) || |
3206 | btf_type_is_resolve_source_only(member_type)) { | |
eb3f595d MKL |
3207 | btf_verifier_log_member(env, v->t, member, |
3208 | "Invalid member"); | |
3209 | return -EINVAL; | |
3210 | } | |
3211 | ||
3212 | if (!env_type_is_resolve_sink(env, member_type) && | |
3213 | !env_type_is_resolved(env, member_type_id)) { | |
3214 | env_stack_set_next_member(env, i + 1); | |
3215 | return env_stack_push(env, member_type, member_type_id); | |
3216 | } | |
179cde8c | 3217 | |
9d5f9f70 YS |
3218 | if (btf_type_kflag(v->t)) |
3219 | err = btf_type_ops(member_type)->check_kflag_member(env, v->t, | |
3220 | member, | |
3221 | member_type); | |
3222 | else | |
3223 | err = btf_type_ops(member_type)->check_member(env, v->t, | |
3224 | member, | |
3225 | member_type); | |
179cde8c MKL |
3226 | if (err) |
3227 | return err; | |
eb3f595d MKL |
3228 | } |
3229 | ||
3230 | env_stack_pop_resolved(env, 0, 0); | |
3231 | ||
3232 | return 0; | |
3233 | } | |
3234 | ||
69b693f0 MKL |
3235 | static void btf_struct_log(struct btf_verifier_env *env, |
3236 | const struct btf_type *t) | |
3237 | { | |
3238 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
3239 | } | |
3240 | ||
61df10c7 KKD |
3241 | enum { |
3242 | BTF_FIELD_IGNORE = 0, | |
3243 | BTF_FIELD_FOUND = 1, | |
42ba1308 KKD |
3244 | }; |
3245 | ||
3246 | struct btf_field_info { | |
aa3496ac | 3247 | enum btf_field_type type; |
42ba1308 | 3248 | u32 off; |
f0c5941f KKD |
3249 | union { |
3250 | struct { | |
3251 | u32 type_id; | |
3252 | } kptr; | |
3253 | struct { | |
3254 | const char *node_name; | |
3255 | u32 value_btf_id; | |
30465003 | 3256 | } graph_root; |
f0c5941f | 3257 | }; |
42ba1308 KKD |
3258 | }; |
3259 | ||
3260 | static int btf_find_struct(const struct btf *btf, const struct btf_type *t, | |
db559117 KKD |
3261 | u32 off, int sz, enum btf_field_type field_type, |
3262 | struct btf_field_info *info) | |
42ba1308 KKD |
3263 | { |
3264 | if (!__btf_type_is_struct(t)) | |
61df10c7 | 3265 | return BTF_FIELD_IGNORE; |
42ba1308 | 3266 | if (t->size != sz) |
61df10c7 | 3267 | return BTF_FIELD_IGNORE; |
db559117 | 3268 | info->type = field_type; |
42ba1308 | 3269 | info->off = off; |
61df10c7 KKD |
3270 | return BTF_FIELD_FOUND; |
3271 | } | |
3272 | ||
3273 | static int btf_find_kptr(const struct btf *btf, const struct btf_type *t, | |
3274 | u32 off, int sz, struct btf_field_info *info) | |
3275 | { | |
aa3496ac | 3276 | enum btf_field_type type; |
61df10c7 KKD |
3277 | u32 res_id; |
3278 | ||
23da464d KKD |
3279 | /* Permit modifiers on the pointer itself */ |
3280 | if (btf_type_is_volatile(t)) | |
3281 | t = btf_type_by_id(btf, t->type); | |
61df10c7 KKD |
3282 | /* For PTR, sz is always == 8 */ |
3283 | if (!btf_type_is_ptr(t)) | |
3284 | return BTF_FIELD_IGNORE; | |
3285 | t = btf_type_by_id(btf, t->type); | |
3286 | ||
3287 | if (!btf_type_is_type_tag(t)) | |
3288 | return BTF_FIELD_IGNORE; | |
3289 | /* Reject extra tags */ | |
3290 | if (btf_type_is_type_tag(btf_type_by_id(btf, t->type))) | |
3291 | return -EINVAL; | |
03b77e17 | 3292 | if (!strcmp("kptr_untrusted", __btf_name_by_offset(btf, t->name_off))) |
c0a5a21c | 3293 | type = BPF_KPTR_UNREF; |
03b77e17 | 3294 | else if (!strcmp("kptr", __btf_name_by_offset(btf, t->name_off))) |
c0a5a21c | 3295 | type = BPF_KPTR_REF; |
55db92f4 YS |
3296 | else if (!strcmp("percpu_kptr", __btf_name_by_offset(btf, t->name_off))) |
3297 | type = BPF_KPTR_PERCPU; | |
c0a5a21c | 3298 | else |
61df10c7 KKD |
3299 | return -EINVAL; |
3300 | ||
3301 | /* Get the base type */ | |
3302 | t = btf_type_skip_modifiers(btf, t->type, &res_id); | |
3303 | /* Only pointer to struct is allowed */ | |
3304 | if (!__btf_type_is_struct(t)) | |
3305 | return -EINVAL; | |
3306 | ||
c0a5a21c | 3307 | info->type = type; |
db559117 KKD |
3308 | info->off = off; |
3309 | info->kptr.type_id = res_id; | |
61df10c7 | 3310 | return BTF_FIELD_FOUND; |
42ba1308 KKD |
3311 | } |
3312 | ||
b9ae0c9d KKD |
3313 | const char *btf_find_decl_tag_value(const struct btf *btf, const struct btf_type *pt, |
3314 | int comp_idx, const char *tag_key) | |
f0c5941f | 3315 | { |
b9ae0c9d | 3316 | const char *value = NULL; |
f0c5941f KKD |
3317 | int i; |
3318 | ||
3319 | for (i = 1; i < btf_nr_types(btf); i++) { | |
3320 | const struct btf_type *t = btf_type_by_id(btf, i); | |
3321 | int len = strlen(tag_key); | |
3322 | ||
3323 | if (!btf_type_is_decl_tag(t)) | |
3324 | continue; | |
3325 | if (pt != btf_type_by_id(btf, t->type) || | |
3326 | btf_type_decl_tag(t)->component_idx != comp_idx) | |
3327 | continue; | |
3328 | if (strncmp(__btf_name_by_offset(btf, t->name_off), tag_key, len)) | |
3329 | continue; | |
b9ae0c9d KKD |
3330 | /* Prevent duplicate entries for same type */ |
3331 | if (value) | |
3332 | return ERR_PTR(-EEXIST); | |
3333 | value = __btf_name_by_offset(btf, t->name_off) + len; | |
f0c5941f | 3334 | } |
b9ae0c9d KKD |
3335 | if (!value) |
3336 | return ERR_PTR(-ENOENT); | |
3337 | return value; | |
f0c5941f KKD |
3338 | } |
3339 | ||
9c395c1b DM |
3340 | static int |
3341 | btf_find_graph_root(const struct btf *btf, const struct btf_type *pt, | |
3342 | const struct btf_type *t, int comp_idx, u32 off, | |
3343 | int sz, struct btf_field_info *info, | |
3344 | enum btf_field_type head_type) | |
f0c5941f | 3345 | { |
9c395c1b | 3346 | const char *node_field_name; |
f0c5941f | 3347 | const char *value_type; |
f0c5941f KKD |
3348 | s32 id; |
3349 | ||
3350 | if (!__btf_type_is_struct(t)) | |
3351 | return BTF_FIELD_IGNORE; | |
3352 | if (t->size != sz) | |
3353 | return BTF_FIELD_IGNORE; | |
3354 | value_type = btf_find_decl_tag_value(btf, pt, comp_idx, "contains:"); | |
b9ae0c9d | 3355 | if (IS_ERR(value_type)) |
f0c5941f | 3356 | return -EINVAL; |
9c395c1b DM |
3357 | node_field_name = strstr(value_type, ":"); |
3358 | if (!node_field_name) | |
f0c5941f | 3359 | return -EINVAL; |
9c395c1b | 3360 | value_type = kstrndup(value_type, node_field_name - value_type, GFP_KERNEL | __GFP_NOWARN); |
f0c5941f KKD |
3361 | if (!value_type) |
3362 | return -ENOMEM; | |
3363 | id = btf_find_by_name_kind(btf, value_type, BTF_KIND_STRUCT); | |
3364 | kfree(value_type); | |
3365 | if (id < 0) | |
3366 | return id; | |
9c395c1b DM |
3367 | node_field_name++; |
3368 | if (str_is_empty(node_field_name)) | |
f0c5941f | 3369 | return -EINVAL; |
9c395c1b | 3370 | info->type = head_type; |
f0c5941f | 3371 | info->off = off; |
30465003 | 3372 | info->graph_root.value_btf_id = id; |
9c395c1b | 3373 | info->graph_root.node_name = node_field_name; |
f0c5941f KKD |
3374 | return BTF_FIELD_FOUND; |
3375 | } | |
3376 | ||
9c395c1b DM |
3377 | #define field_mask_test_name(field_type, field_type_str) \ |
3378 | if (field_mask & field_type && !strcmp(name, field_type_str)) { \ | |
3379 | type = field_type; \ | |
3380 | goto end; \ | |
3381 | } | |
3382 | ||
db559117 KKD |
3383 | static int btf_get_field_type(const char *name, u32 field_mask, u32 *seen_mask, |
3384 | int *align, int *sz) | |
3385 | { | |
3386 | int type = 0; | |
3387 | ||
3388 | if (field_mask & BPF_SPIN_LOCK) { | |
3389 | if (!strcmp(name, "bpf_spin_lock")) { | |
3390 | if (*seen_mask & BPF_SPIN_LOCK) | |
3391 | return -E2BIG; | |
3392 | *seen_mask |= BPF_SPIN_LOCK; | |
3393 | type = BPF_SPIN_LOCK; | |
3394 | goto end; | |
3395 | } | |
3396 | } | |
3397 | if (field_mask & BPF_TIMER) { | |
3398 | if (!strcmp(name, "bpf_timer")) { | |
3399 | if (*seen_mask & BPF_TIMER) | |
3400 | return -E2BIG; | |
3401 | *seen_mask |= BPF_TIMER; | |
3402 | type = BPF_TIMER; | |
3403 | goto end; | |
3404 | } | |
3405 | } | |
9c395c1b DM |
3406 | field_mask_test_name(BPF_LIST_HEAD, "bpf_list_head"); |
3407 | field_mask_test_name(BPF_LIST_NODE, "bpf_list_node"); | |
3408 | field_mask_test_name(BPF_RB_ROOT, "bpf_rb_root"); | |
3409 | field_mask_test_name(BPF_RB_NODE, "bpf_rb_node"); | |
d54730b5 | 3410 | field_mask_test_name(BPF_REFCOUNT, "bpf_refcount"); |
9c395c1b | 3411 | |
db559117 KKD |
3412 | /* Only return BPF_KPTR when all other types with matchable names fail */ |
3413 | if (field_mask & BPF_KPTR) { | |
3414 | type = BPF_KPTR_REF; | |
3415 | goto end; | |
3416 | } | |
3417 | return 0; | |
3418 | end: | |
3419 | *sz = btf_field_type_size(type); | |
3420 | *align = btf_field_type_align(type); | |
3421 | return type; | |
3422 | } | |
3423 | ||
9c395c1b DM |
3424 | #undef field_mask_test_name |
3425 | ||
db559117 KKD |
3426 | static int btf_find_struct_field(const struct btf *btf, |
3427 | const struct btf_type *t, u32 field_mask, | |
61df10c7 | 3428 | struct btf_field_info *info, int info_cnt) |
d83525ca | 3429 | { |
db559117 | 3430 | int ret, idx = 0, align, sz, field_type; |
d83525ca | 3431 | const struct btf_member *member; |
61df10c7 | 3432 | struct btf_field_info tmp; |
db559117 | 3433 | u32 i, off, seen_mask = 0; |
d83525ca | 3434 | |
d83525ca AS |
3435 | for_each_member(i, t, member) { |
3436 | const struct btf_type *member_type = btf_type_by_id(btf, | |
3437 | member->type); | |
42ba1308 | 3438 | |
db559117 KKD |
3439 | field_type = btf_get_field_type(__btf_name_by_offset(btf, member_type->name_off), |
3440 | field_mask, &seen_mask, &align, &sz); | |
3441 | if (field_type == 0) | |
d83525ca | 3442 | continue; |
db559117 KKD |
3443 | if (field_type < 0) |
3444 | return field_type; | |
42ba1308 | 3445 | |
8293eb99 | 3446 | off = __btf_member_bit_offset(t, member); |
d83525ca AS |
3447 | if (off % 8) |
3448 | /* valid C code cannot generate such BTF */ | |
3449 | return -EINVAL; | |
3450 | off /= 8; | |
68134668 | 3451 | if (off % align) |
db559117 | 3452 | continue; |
42ba1308 KKD |
3453 | |
3454 | switch (field_type) { | |
db559117 KKD |
3455 | case BPF_SPIN_LOCK: |
3456 | case BPF_TIMER: | |
8ffa5cc1 | 3457 | case BPF_LIST_NODE: |
9c395c1b | 3458 | case BPF_RB_NODE: |
d54730b5 | 3459 | case BPF_REFCOUNT: |
db559117 | 3460 | ret = btf_find_struct(btf, member_type, off, sz, field_type, |
61df10c7 KKD |
3461 | idx < info_cnt ? &info[idx] : &tmp); |
3462 | if (ret < 0) | |
3463 | return ret; | |
3464 | break; | |
db559117 KKD |
3465 | case BPF_KPTR_UNREF: |
3466 | case BPF_KPTR_REF: | |
55db92f4 | 3467 | case BPF_KPTR_PERCPU: |
61df10c7 KKD |
3468 | ret = btf_find_kptr(btf, member_type, off, sz, |
3469 | idx < info_cnt ? &info[idx] : &tmp); | |
3470 | if (ret < 0) | |
3471 | return ret; | |
3472 | break; | |
f0c5941f | 3473 | case BPF_LIST_HEAD: |
9c395c1b DM |
3474 | case BPF_RB_ROOT: |
3475 | ret = btf_find_graph_root(btf, t, member_type, | |
3476 | i, off, sz, | |
3477 | idx < info_cnt ? &info[idx] : &tmp, | |
3478 | field_type); | |
f0c5941f KKD |
3479 | if (ret < 0) |
3480 | return ret; | |
3481 | break; | |
42ba1308 KKD |
3482 | default: |
3483 | return -EFAULT; | |
3484 | } | |
61df10c7 KKD |
3485 | |
3486 | if (ret == BTF_FIELD_IGNORE) | |
3487 | continue; | |
3488 | if (idx >= info_cnt) | |
3489 | return -E2BIG; | |
3490 | ++idx; | |
68134668 | 3491 | } |
61df10c7 | 3492 | return idx; |
68134668 AS |
3493 | } |
3494 | ||
3495 | static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t, | |
db559117 KKD |
3496 | u32 field_mask, struct btf_field_info *info, |
3497 | int info_cnt) | |
68134668 | 3498 | { |
db559117 | 3499 | int ret, idx = 0, align, sz, field_type; |
68134668 | 3500 | const struct btf_var_secinfo *vsi; |
61df10c7 | 3501 | struct btf_field_info tmp; |
db559117 | 3502 | u32 i, off, seen_mask = 0; |
68134668 AS |
3503 | |
3504 | for_each_vsi(i, t, vsi) { | |
3505 | const struct btf_type *var = btf_type_by_id(btf, vsi->type); | |
3506 | const struct btf_type *var_type = btf_type_by_id(btf, var->type); | |
3507 | ||
db559117 KKD |
3508 | field_type = btf_get_field_type(__btf_name_by_offset(btf, var_type->name_off), |
3509 | field_mask, &seen_mask, &align, &sz); | |
3510 | if (field_type == 0) | |
68134668 | 3511 | continue; |
db559117 KKD |
3512 | if (field_type < 0) |
3513 | return field_type; | |
3514 | ||
3515 | off = vsi->offset; | |
68134668 AS |
3516 | if (vsi->size != sz) |
3517 | continue; | |
68134668 | 3518 | if (off % align) |
db559117 | 3519 | continue; |
42ba1308 KKD |
3520 | |
3521 | switch (field_type) { | |
db559117 KKD |
3522 | case BPF_SPIN_LOCK: |
3523 | case BPF_TIMER: | |
8ffa5cc1 | 3524 | case BPF_LIST_NODE: |
9c395c1b | 3525 | case BPF_RB_NODE: |
d54730b5 | 3526 | case BPF_REFCOUNT: |
db559117 | 3527 | ret = btf_find_struct(btf, var_type, off, sz, field_type, |
61df10c7 KKD |
3528 | idx < info_cnt ? &info[idx] : &tmp); |
3529 | if (ret < 0) | |
3530 | return ret; | |
3531 | break; | |
db559117 KKD |
3532 | case BPF_KPTR_UNREF: |
3533 | case BPF_KPTR_REF: | |
55db92f4 | 3534 | case BPF_KPTR_PERCPU: |
61df10c7 KKD |
3535 | ret = btf_find_kptr(btf, var_type, off, sz, |
3536 | idx < info_cnt ? &info[idx] : &tmp); | |
3537 | if (ret < 0) | |
3538 | return ret; | |
3539 | break; | |
f0c5941f | 3540 | case BPF_LIST_HEAD: |
9c395c1b DM |
3541 | case BPF_RB_ROOT: |
3542 | ret = btf_find_graph_root(btf, var, var_type, | |
3543 | -1, off, sz, | |
3544 | idx < info_cnt ? &info[idx] : &tmp, | |
3545 | field_type); | |
f0c5941f KKD |
3546 | if (ret < 0) |
3547 | return ret; | |
3548 | break; | |
42ba1308 KKD |
3549 | default: |
3550 | return -EFAULT; | |
3551 | } | |
61df10c7 KKD |
3552 | |
3553 | if (ret == BTF_FIELD_IGNORE) | |
3554 | continue; | |
3555 | if (idx >= info_cnt) | |
3556 | return -E2BIG; | |
3557 | ++idx; | |
d83525ca | 3558 | } |
61df10c7 | 3559 | return idx; |
d83525ca AS |
3560 | } |
3561 | ||
68134668 | 3562 | static int btf_find_field(const struct btf *btf, const struct btf_type *t, |
db559117 KKD |
3563 | u32 field_mask, struct btf_field_info *info, |
3564 | int info_cnt) | |
68134668 | 3565 | { |
68134668 | 3566 | if (__btf_type_is_struct(t)) |
db559117 | 3567 | return btf_find_struct_field(btf, t, field_mask, info, info_cnt); |
68134668 | 3568 | else if (btf_type_is_datasec(t)) |
db559117 | 3569 | return btf_find_datasec_var(btf, t, field_mask, info, info_cnt); |
68134668 AS |
3570 | return -EINVAL; |
3571 | } | |
3572 | ||
db559117 KKD |
3573 | static int btf_parse_kptr(const struct btf *btf, struct btf_field *field, |
3574 | struct btf_field_info *info) | |
68134668 | 3575 | { |
db559117 KKD |
3576 | struct module *mod = NULL; |
3577 | const struct btf_type *t; | |
c8e18754 DM |
3578 | /* If a matching btf type is found in kernel or module BTFs, kptr_ref |
3579 | * is that BTF, otherwise it's program BTF | |
3580 | */ | |
3581 | struct btf *kptr_btf; | |
42ba1308 | 3582 | int ret; |
db559117 | 3583 | s32 id; |
42ba1308 | 3584 | |
db559117 KKD |
3585 | /* Find type in map BTF, and use it to look up the matching type |
3586 | * in vmlinux or module BTFs, by name and kind. | |
3587 | */ | |
3588 | t = btf_type_by_id(btf, info->kptr.type_id); | |
3589 | id = bpf_find_btf_id(__btf_name_by_offset(btf, t->name_off), BTF_INFO_KIND(t->info), | |
c8e18754 DM |
3590 | &kptr_btf); |
3591 | if (id == -ENOENT) { | |
3592 | /* btf_parse_kptr should only be called w/ btf = program BTF */ | |
3593 | WARN_ON_ONCE(btf_is_kernel(btf)); | |
3594 | ||
3595 | /* Type exists only in program BTF. Assume that it's a MEM_ALLOC | |
3596 | * kptr allocated via bpf_obj_new | |
3597 | */ | |
9e36a204 | 3598 | field->kptr.dtor = NULL; |
c8e18754 DM |
3599 | id = info->kptr.type_id; |
3600 | kptr_btf = (struct btf *)btf; | |
3601 | btf_get(kptr_btf); | |
3602 | goto found_dtor; | |
3603 | } | |
db559117 KKD |
3604 | if (id < 0) |
3605 | return id; | |
3606 | ||
3607 | /* Find and stash the function pointer for the destruction function that | |
3608 | * needs to be eventually invoked from the map free path. | |
3609 | */ | |
3610 | if (info->type == BPF_KPTR_REF) { | |
3611 | const struct btf_type *dtor_func; | |
3612 | const char *dtor_func_name; | |
3613 | unsigned long addr; | |
3614 | s32 dtor_btf_id; | |
3615 | ||
3616 | /* This call also serves as a whitelist of allowed objects that | |
3617 | * can be used as a referenced pointer and be stored in a map at | |
3618 | * the same time. | |
3619 | */ | |
c8e18754 | 3620 | dtor_btf_id = btf_find_dtor_kfunc(kptr_btf, id); |
db559117 KKD |
3621 | if (dtor_btf_id < 0) { |
3622 | ret = dtor_btf_id; | |
3623 | goto end_btf; | |
3624 | } | |
68134668 | 3625 | |
c8e18754 | 3626 | dtor_func = btf_type_by_id(kptr_btf, dtor_btf_id); |
db559117 KKD |
3627 | if (!dtor_func) { |
3628 | ret = -ENOENT; | |
3629 | goto end_btf; | |
3630 | } | |
42ba1308 | 3631 | |
c8e18754 DM |
3632 | if (btf_is_module(kptr_btf)) { |
3633 | mod = btf_try_get_module(kptr_btf); | |
db559117 KKD |
3634 | if (!mod) { |
3635 | ret = -ENXIO; | |
3636 | goto end_btf; | |
3637 | } | |
3638 | } | |
3639 | ||
3640 | /* We already verified dtor_func to be btf_type_is_func | |
3641 | * in register_btf_id_dtor_kfuncs. | |
3642 | */ | |
c8e18754 | 3643 | dtor_func_name = __btf_name_by_offset(kptr_btf, dtor_func->name_off); |
db559117 KKD |
3644 | addr = kallsyms_lookup_name(dtor_func_name); |
3645 | if (!addr) { | |
3646 | ret = -EINVAL; | |
3647 | goto end_mod; | |
3648 | } | |
3649 | field->kptr.dtor = (void *)addr; | |
3650 | } | |
3651 | ||
c8e18754 | 3652 | found_dtor: |
db559117 | 3653 | field->kptr.btf_id = id; |
c8e18754 | 3654 | field->kptr.btf = kptr_btf; |
db559117 KKD |
3655 | field->kptr.module = mod; |
3656 | return 0; | |
3657 | end_mod: | |
3658 | module_put(mod); | |
3659 | end_btf: | |
c8e18754 | 3660 | btf_put(kptr_btf); |
db559117 | 3661 | return ret; |
68134668 AS |
3662 | } |
3663 | ||
9c395c1b DM |
3664 | static int btf_parse_graph_root(const struct btf *btf, |
3665 | struct btf_field *field, | |
3666 | struct btf_field_info *info, | |
3667 | const char *node_type_name, | |
3668 | size_t node_type_align) | |
f0c5941f KKD |
3669 | { |
3670 | const struct btf_type *t, *n = NULL; | |
3671 | const struct btf_member *member; | |
3672 | u32 offset; | |
3673 | int i; | |
3674 | ||
30465003 | 3675 | t = btf_type_by_id(btf, info->graph_root.value_btf_id); |
f0c5941f KKD |
3676 | /* We've already checked that value_btf_id is a struct type. We |
3677 | * just need to figure out the offset of the list_node, and | |
3678 | * verify its type. | |
3679 | */ | |
3680 | for_each_member(i, t, member) { | |
30465003 DM |
3681 | if (strcmp(info->graph_root.node_name, |
3682 | __btf_name_by_offset(btf, member->name_off))) | |
f0c5941f KKD |
3683 | continue; |
3684 | /* Invalid BTF, two members with same name */ | |
3685 | if (n) | |
3686 | return -EINVAL; | |
3687 | n = btf_type_by_id(btf, member->type); | |
3688 | if (!__btf_type_is_struct(n)) | |
3689 | return -EINVAL; | |
9c395c1b | 3690 | if (strcmp(node_type_name, __btf_name_by_offset(btf, n->name_off))) |
f0c5941f KKD |
3691 | return -EINVAL; |
3692 | offset = __btf_member_bit_offset(n, member); | |
3693 | if (offset % 8) | |
3694 | return -EINVAL; | |
3695 | offset /= 8; | |
9c395c1b | 3696 | if (offset % node_type_align) |
f0c5941f KKD |
3697 | return -EINVAL; |
3698 | ||
30465003 DM |
3699 | field->graph_root.btf = (struct btf *)btf; |
3700 | field->graph_root.value_btf_id = info->graph_root.value_btf_id; | |
3701 | field->graph_root.node_offset = offset; | |
f0c5941f KKD |
3702 | } |
3703 | if (!n) | |
3704 | return -ENOENT; | |
3705 | return 0; | |
3706 | } | |
3707 | ||
9c395c1b DM |
3708 | static int btf_parse_list_head(const struct btf *btf, struct btf_field *field, |
3709 | struct btf_field_info *info) | |
3710 | { | |
3711 | return btf_parse_graph_root(btf, field, info, "bpf_list_node", | |
3712 | __alignof__(struct bpf_list_node)); | |
3713 | } | |
3714 | ||
3715 | static int btf_parse_rb_root(const struct btf *btf, struct btf_field *field, | |
3716 | struct btf_field_info *info) | |
3717 | { | |
3718 | return btf_parse_graph_root(btf, field, info, "bpf_rb_node", | |
3719 | __alignof__(struct bpf_rb_node)); | |
3720 | } | |
3721 | ||
cd2a8079 DM |
3722 | static int btf_field_cmp(const void *_a, const void *_b, const void *priv) |
3723 | { | |
3724 | const struct btf_field *a = (const struct btf_field *)_a; | |
3725 | const struct btf_field *b = (const struct btf_field *)_b; | |
3726 | ||
3727 | if (a->offset < b->offset) | |
3728 | return -1; | |
3729 | else if (a->offset > b->offset) | |
3730 | return 1; | |
3731 | return 0; | |
3732 | } | |
3733 | ||
db559117 KKD |
3734 | struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t, |
3735 | u32 field_mask, u32 value_size) | |
61df10c7 | 3736 | { |
aa3496ac | 3737 | struct btf_field_info info_arr[BTF_FIELDS_MAX]; |
cd2a8079 | 3738 | u32 next_off = 0, field_type_size; |
aa3496ac KKD |
3739 | struct btf_record *rec; |
3740 | int ret, i, cnt; | |
61df10c7 | 3741 | |
db559117 | 3742 | ret = btf_find_field(btf, t, field_mask, info_arr, ARRAY_SIZE(info_arr)); |
61df10c7 KKD |
3743 | if (ret < 0) |
3744 | return ERR_PTR(ret); | |
3745 | if (!ret) | |
3746 | return NULL; | |
3747 | ||
aa3496ac | 3748 | cnt = ret; |
c22dfdd2 KKD |
3749 | /* This needs to be kzalloc to zero out padding and unused fields, see |
3750 | * comment in btf_record_equal. | |
3751 | */ | |
aa3496ac KKD |
3752 | rec = kzalloc(offsetof(struct btf_record, fields[cnt]), GFP_KERNEL | __GFP_NOWARN); |
3753 | if (!rec) | |
61df10c7 | 3754 | return ERR_PTR(-ENOMEM); |
61df10c7 | 3755 | |
db559117 KKD |
3756 | rec->spin_lock_off = -EINVAL; |
3757 | rec->timer_off = -EINVAL; | |
d54730b5 | 3758 | rec->refcount_off = -EINVAL; |
db559117 | 3759 | for (i = 0; i < cnt; i++) { |
cd2a8079 DM |
3760 | field_type_size = btf_field_type_size(info_arr[i].type); |
3761 | if (info_arr[i].off + field_type_size > value_size) { | |
db559117 KKD |
3762 | WARN_ONCE(1, "verifier bug off %d size %d", info_arr[i].off, value_size); |
3763 | ret = -EFAULT; | |
61df10c7 KKD |
3764 | goto end; |
3765 | } | |
f0c5941f KKD |
3766 | if (info_arr[i].off < next_off) { |
3767 | ret = -EEXIST; | |
3768 | goto end; | |
3769 | } | |
cd2a8079 | 3770 | next_off = info_arr[i].off + field_type_size; |
61df10c7 | 3771 | |
aa3496ac KKD |
3772 | rec->field_mask |= info_arr[i].type; |
3773 | rec->fields[i].offset = info_arr[i].off; | |
3774 | rec->fields[i].type = info_arr[i].type; | |
cd2a8079 | 3775 | rec->fields[i].size = field_type_size; |
db559117 KKD |
3776 | |
3777 | switch (info_arr[i].type) { | |
3778 | case BPF_SPIN_LOCK: | |
3779 | WARN_ON_ONCE(rec->spin_lock_off >= 0); | |
3780 | /* Cache offset for faster lookup at runtime */ | |
3781 | rec->spin_lock_off = rec->fields[i].offset; | |
3782 | break; | |
3783 | case BPF_TIMER: | |
3784 | WARN_ON_ONCE(rec->timer_off >= 0); | |
3785 | /* Cache offset for faster lookup at runtime */ | |
3786 | rec->timer_off = rec->fields[i].offset; | |
3787 | break; | |
d54730b5 DM |
3788 | case BPF_REFCOUNT: |
3789 | WARN_ON_ONCE(rec->refcount_off >= 0); | |
3790 | /* Cache offset for faster lookup at runtime */ | |
3791 | rec->refcount_off = rec->fields[i].offset; | |
3792 | break; | |
db559117 KKD |
3793 | case BPF_KPTR_UNREF: |
3794 | case BPF_KPTR_REF: | |
55db92f4 | 3795 | case BPF_KPTR_PERCPU: |
db559117 KKD |
3796 | ret = btf_parse_kptr(btf, &rec->fields[i], &info_arr[i]); |
3797 | if (ret < 0) | |
3798 | goto end; | |
3799 | break; | |
f0c5941f KKD |
3800 | case BPF_LIST_HEAD: |
3801 | ret = btf_parse_list_head(btf, &rec->fields[i], &info_arr[i]); | |
3802 | if (ret < 0) | |
3803 | goto end; | |
3804 | break; | |
9c395c1b DM |
3805 | case BPF_RB_ROOT: |
3806 | ret = btf_parse_rb_root(btf, &rec->fields[i], &info_arr[i]); | |
3807 | if (ret < 0) | |
3808 | goto end; | |
3809 | break; | |
8ffa5cc1 | 3810 | case BPF_LIST_NODE: |
9c395c1b | 3811 | case BPF_RB_NODE: |
8ffa5cc1 | 3812 | break; |
db559117 KKD |
3813 | default: |
3814 | ret = -EFAULT; | |
3815 | goto end; | |
3816 | } | |
aa3496ac | 3817 | rec->cnt++; |
61df10c7 | 3818 | } |
f0c5941f | 3819 | |
9c395c1b DM |
3820 | /* bpf_{list_head, rb_node} require bpf_spin_lock */ |
3821 | if ((btf_record_has_field(rec, BPF_LIST_HEAD) || | |
3822 | btf_record_has_field(rec, BPF_RB_ROOT)) && rec->spin_lock_off < 0) { | |
f0c5941f KKD |
3823 | ret = -EINVAL; |
3824 | goto end; | |
3825 | } | |
3826 | ||
404ad75a DM |
3827 | if (rec->refcount_off < 0 && |
3828 | btf_record_has_field(rec, BPF_LIST_NODE) && | |
a40d3632 DM |
3829 | btf_record_has_field(rec, BPF_RB_NODE)) { |
3830 | ret = -EINVAL; | |
3831 | goto end; | |
3832 | } | |
3833 | ||
cd2a8079 DM |
3834 | sort_r(rec->fields, rec->cnt, sizeof(struct btf_field), btf_field_cmp, |
3835 | NULL, rec); | |
3836 | ||
aa3496ac | 3837 | return rec; |
61df10c7 | 3838 | end: |
aa3496ac | 3839 | btf_record_free(rec); |
61df10c7 KKD |
3840 | return ERR_PTR(ret); |
3841 | } | |
3842 | ||
865ce09a KKD |
3843 | int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec) |
3844 | { | |
3845 | int i; | |
3846 | ||
9c395c1b DM |
3847 | /* There are three types that signify ownership of some other type: |
3848 | * kptr_ref, bpf_list_head, bpf_rb_root. | |
3849 | * kptr_ref only supports storing kernel types, which can't store | |
3850 | * references to program allocated local types. | |
3851 | * | |
3852 | * Hence we only need to ensure that bpf_{list_head,rb_root} ownership | |
3853 | * does not form cycles. | |
865ce09a | 3854 | */ |
790ce3cf | 3855 | if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & BPF_GRAPH_ROOT)) |
865ce09a KKD |
3856 | return 0; |
3857 | for (i = 0; i < rec->cnt; i++) { | |
3858 | struct btf_struct_meta *meta; | |
3859 | u32 btf_id; | |
3860 | ||
790ce3cf | 3861 | if (!(rec->fields[i].type & BPF_GRAPH_ROOT)) |
865ce09a | 3862 | continue; |
30465003 | 3863 | btf_id = rec->fields[i].graph_root.value_btf_id; |
865ce09a KKD |
3864 | meta = btf_find_struct_meta(btf, btf_id); |
3865 | if (!meta) | |
3866 | return -EFAULT; | |
30465003 | 3867 | rec->fields[i].graph_root.value_rec = meta->record; |
865ce09a | 3868 | |
9c395c1b DM |
3869 | /* We need to set value_rec for all root types, but no need |
3870 | * to check ownership cycle for a type unless it's also a | |
3871 | * node type. | |
3872 | */ | |
790ce3cf | 3873 | if (!(rec->field_mask & BPF_GRAPH_NODE)) |
865ce09a KKD |
3874 | continue; |
3875 | ||
3876 | /* We need to ensure ownership acyclicity among all types. The | |
3877 | * proper way to do it would be to topologically sort all BTF | |
3878 | * IDs based on the ownership edges, since there can be multiple | |
9c395c1b DM |
3879 | * bpf_{list_head,rb_node} in a type. Instead, we use the |
3880 | * following resaoning: | |
865ce09a KKD |
3881 | * |
3882 | * - A type can only be owned by another type in user BTF if it | |
9c395c1b | 3883 | * has a bpf_{list,rb}_node. Let's call these node types. |
865ce09a | 3884 | * - A type can only _own_ another type in user BTF if it has a |
9c395c1b | 3885 | * bpf_{list_head,rb_root}. Let's call these root types. |
865ce09a | 3886 | * |
9c395c1b DM |
3887 | * We ensure that if a type is both a root and node, its |
3888 | * element types cannot be root types. | |
865ce09a KKD |
3889 | * |
3890 | * To ensure acyclicity: | |
3891 | * | |
9c395c1b DM |
3892 | * When A is an root type but not a node, its ownership |
3893 | * chain can be: | |
865ce09a KKD |
3894 | * A -> B -> C |
3895 | * Where: | |
9c395c1b DM |
3896 | * - A is an root, e.g. has bpf_rb_root. |
3897 | * - B is both a root and node, e.g. has bpf_rb_node and | |
3898 | * bpf_list_head. | |
3899 | * - C is only an root, e.g. has bpf_list_node | |
865ce09a | 3900 | * |
9c395c1b DM |
3901 | * When A is both a root and node, some other type already |
3902 | * owns it in the BTF domain, hence it can not own | |
3903 | * another root type through any of the ownership edges. | |
865ce09a KKD |
3904 | * A -> B |
3905 | * Where: | |
9c395c1b DM |
3906 | * - A is both an root and node. |
3907 | * - B is only an node. | |
865ce09a | 3908 | */ |
790ce3cf | 3909 | if (meta->record->field_mask & BPF_GRAPH_ROOT) |
865ce09a KKD |
3910 | return -ELOOP; |
3911 | } | |
3912 | return 0; | |
3913 | } | |
3914 | ||
31d0bc81 AM |
3915 | static void __btf_struct_show(const struct btf *btf, const struct btf_type *t, |
3916 | u32 type_id, void *data, u8 bits_offset, | |
3917 | struct btf_show *show) | |
b00b8dae | 3918 | { |
b00b8dae | 3919 | const struct btf_member *member; |
31d0bc81 | 3920 | void *safe_data; |
b00b8dae MKL |
3921 | u32 i; |
3922 | ||
31d0bc81 AM |
3923 | safe_data = btf_show_start_struct_type(show, t, type_id, data); |
3924 | if (!safe_data) | |
3925 | return; | |
3926 | ||
b00b8dae MKL |
3927 | for_each_member(i, t, member) { |
3928 | const struct btf_type *member_type = btf_type_by_id(btf, | |
3929 | member->type); | |
b00b8dae | 3930 | const struct btf_kind_operations *ops; |
9d5f9f70 YS |
3931 | u32 member_offset, bitfield_size; |
3932 | u32 bytes_offset; | |
3933 | u8 bits8_offset; | |
b00b8dae | 3934 | |
31d0bc81 | 3935 | btf_show_start_member(show, member); |
b00b8dae | 3936 | |
8293eb99 AS |
3937 | member_offset = __btf_member_bit_offset(t, member); |
3938 | bitfield_size = __btf_member_bitfield_size(t, member); | |
17e3ac81 YS |
3939 | bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset); |
3940 | bits8_offset = BITS_PER_BYTE_MASKED(member_offset); | |
9d5f9f70 | 3941 | if (bitfield_size) { |
31d0bc81 AM |
3942 | safe_data = btf_show_start_type(show, member_type, |
3943 | member->type, | |
3944 | data + bytes_offset); | |
3945 | if (safe_data) | |
3946 | btf_bitfield_show(safe_data, | |
3947 | bits8_offset, | |
3948 | bitfield_size, show); | |
3949 | btf_show_end_type(show); | |
9d5f9f70 | 3950 | } else { |
9d5f9f70 | 3951 | ops = btf_type_ops(member_type); |
31d0bc81 AM |
3952 | ops->show(btf, member_type, member->type, |
3953 | data + bytes_offset, bits8_offset, show); | |
9d5f9f70 | 3954 | } |
31d0bc81 AM |
3955 | |
3956 | btf_show_end_member(show); | |
b00b8dae | 3957 | } |
31d0bc81 AM |
3958 | |
3959 | btf_show_end_struct_type(show); | |
3960 | } | |
3961 | ||
3962 | static void btf_struct_show(const struct btf *btf, const struct btf_type *t, | |
3963 | u32 type_id, void *data, u8 bits_offset, | |
3964 | struct btf_show *show) | |
3965 | { | |
3966 | const struct btf_member *m = show->state.member; | |
3967 | ||
3968 | /* | |
3969 | * First check if any members would be shown (are non-zero). | |
3970 | * See comments above "struct btf_show" definition for more | |
3971 | * details on how this works at a high-level. | |
3972 | */ | |
3973 | if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) { | |
3974 | if (!show->state.depth_check) { | |
3975 | show->state.depth_check = show->state.depth + 1; | |
3976 | show->state.depth_to_show = 0; | |
3977 | } | |
3978 | __btf_struct_show(btf, t, type_id, data, bits_offset, show); | |
3979 | /* Restore saved member data here */ | |
3980 | show->state.member = m; | |
3981 | if (show->state.depth_check != show->state.depth + 1) | |
3982 | return; | |
3983 | show->state.depth_check = 0; | |
3984 | ||
3985 | if (show->state.depth_to_show <= show->state.depth) | |
3986 | return; | |
3987 | /* | |
3988 | * Reaching here indicates we have recursed and found | |
3989 | * non-zero child values. | |
3990 | */ | |
3991 | } | |
3992 | ||
3993 | __btf_struct_show(btf, t, type_id, data, bits_offset, show); | |
b00b8dae MKL |
3994 | } |
3995 | ||
69b693f0 MKL |
3996 | static struct btf_kind_operations struct_ops = { |
3997 | .check_meta = btf_struct_check_meta, | |
eb3f595d | 3998 | .resolve = btf_struct_resolve, |
179cde8c | 3999 | .check_member = btf_struct_check_member, |
9d5f9f70 | 4000 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 4001 | .log_details = btf_struct_log, |
31d0bc81 | 4002 | .show = btf_struct_show, |
69b693f0 MKL |
4003 | }; |
4004 | ||
179cde8c MKL |
4005 | static int btf_enum_check_member(struct btf_verifier_env *env, |
4006 | const struct btf_type *struct_type, | |
4007 | const struct btf_member *member, | |
4008 | const struct btf_type *member_type) | |
4009 | { | |
4010 | u32 struct_bits_off = member->offset; | |
4011 | u32 struct_size, bytes_offset; | |
4012 | ||
4013 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
4014 | btf_verifier_log_member(env, struct_type, member, | |
4015 | "Member is not byte aligned"); | |
4016 | return -EINVAL; | |
4017 | } | |
4018 | ||
4019 | struct_size = struct_type->size; | |
4020 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
da6c7fae | 4021 | if (struct_size - bytes_offset < member_type->size) { |
179cde8c MKL |
4022 | btf_verifier_log_member(env, struct_type, member, |
4023 | "Member exceeds struct_size"); | |
4024 | return -EINVAL; | |
4025 | } | |
4026 | ||
4027 | return 0; | |
4028 | } | |
4029 | ||
9d5f9f70 YS |
4030 | static int btf_enum_check_kflag_member(struct btf_verifier_env *env, |
4031 | const struct btf_type *struct_type, | |
4032 | const struct btf_member *member, | |
4033 | const struct btf_type *member_type) | |
4034 | { | |
4035 | u32 struct_bits_off, nr_bits, bytes_end, struct_size; | |
4036 | u32 int_bitsize = sizeof(int) * BITS_PER_BYTE; | |
4037 | ||
4038 | struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); | |
4039 | nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); | |
4040 | if (!nr_bits) { | |
4041 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
4042 | btf_verifier_log_member(env, struct_type, member, | |
4043 | "Member is not byte aligned"); | |
e3439af4 | 4044 | return -EINVAL; |
9d5f9f70 YS |
4045 | } |
4046 | ||
4047 | nr_bits = int_bitsize; | |
4048 | } else if (nr_bits > int_bitsize) { | |
4049 | btf_verifier_log_member(env, struct_type, member, | |
4050 | "Invalid member bitfield_size"); | |
4051 | return -EINVAL; | |
4052 | } | |
4053 | ||
4054 | struct_size = struct_type->size; | |
4055 | bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits); | |
4056 | if (struct_size < bytes_end) { | |
4057 | btf_verifier_log_member(env, struct_type, member, | |
4058 | "Member exceeds struct_size"); | |
4059 | return -EINVAL; | |
4060 | } | |
4061 | ||
4062 | return 0; | |
4063 | } | |
4064 | ||
69b693f0 MKL |
4065 | static s32 btf_enum_check_meta(struct btf_verifier_env *env, |
4066 | const struct btf_type *t, | |
4067 | u32 meta_left) | |
4068 | { | |
4069 | const struct btf_enum *enums = btf_type_enum(t); | |
4070 | struct btf *btf = env->btf; | |
6089fb32 | 4071 | const char *fmt_str; |
69b693f0 MKL |
4072 | u16 i, nr_enums; |
4073 | u32 meta_needed; | |
4074 | ||
4075 | nr_enums = btf_type_vlen(t); | |
4076 | meta_needed = nr_enums * sizeof(*enums); | |
4077 | ||
4078 | if (meta_left < meta_needed) { | |
4079 | btf_verifier_log_basic(env, t, | |
4080 | "meta_left:%u meta_needed:%u", | |
4081 | meta_left, meta_needed); | |
4082 | return -EINVAL; | |
4083 | } | |
4084 | ||
9eea9849 AS |
4085 | if (t->size > 8 || !is_power_of_2(t->size)) { |
4086 | btf_verifier_log_type(env, t, "Unexpected size"); | |
69b693f0 MKL |
4087 | return -EINVAL; |
4088 | } | |
4089 | ||
eb04bbb6 YS |
4090 | /* enum type either no name or a valid one */ |
4091 | if (t->name_off && | |
4092 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
4093 | btf_verifier_log_type(env, t, "Invalid name"); | |
4094 | return -EINVAL; | |
4095 | } | |
4096 | ||
69b693f0 MKL |
4097 | btf_verifier_log_type(env, t, NULL); |
4098 | ||
4099 | for (i = 0; i < nr_enums; i++) { | |
fbcf93eb | 4100 | if (!btf_name_offset_valid(btf, enums[i].name_off)) { |
69b693f0 | 4101 | btf_verifier_log(env, "\tInvalid name_offset:%u", |
fbcf93eb | 4102 | enums[i].name_off); |
69b693f0 MKL |
4103 | return -EINVAL; |
4104 | } | |
4105 | ||
eb04bbb6 YS |
4106 | /* enum member must have a valid name */ |
4107 | if (!enums[i].name_off || | |
4108 | !btf_name_valid_identifier(btf, enums[i].name_off)) { | |
4109 | btf_verifier_log_type(env, t, "Invalid name"); | |
4110 | return -EINVAL; | |
4111 | } | |
4112 | ||
8580ac94 AS |
4113 | if (env->log.level == BPF_LOG_KERNEL) |
4114 | continue; | |
6089fb32 YS |
4115 | fmt_str = btf_type_kflag(t) ? "\t%s val=%d\n" : "\t%s val=%u\n"; |
4116 | btf_verifier_log(env, fmt_str, | |
23127b33 | 4117 | __btf_name_by_offset(btf, enums[i].name_off), |
69b693f0 MKL |
4118 | enums[i].val); |
4119 | } | |
4120 | ||
4121 | return meta_needed; | |
4122 | } | |
4123 | ||
4124 | static void btf_enum_log(struct btf_verifier_env *env, | |
4125 | const struct btf_type *t) | |
4126 | { | |
4127 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
4128 | } | |
4129 | ||
31d0bc81 AM |
4130 | static void btf_enum_show(const struct btf *btf, const struct btf_type *t, |
4131 | u32 type_id, void *data, u8 bits_offset, | |
4132 | struct btf_show *show) | |
b00b8dae MKL |
4133 | { |
4134 | const struct btf_enum *enums = btf_type_enum(t); | |
4135 | u32 i, nr_enums = btf_type_vlen(t); | |
31d0bc81 AM |
4136 | void *safe_data; |
4137 | int v; | |
4138 | ||
4139 | safe_data = btf_show_start_type(show, t, type_id, data); | |
4140 | if (!safe_data) | |
4141 | return; | |
4142 | ||
4143 | v = *(int *)safe_data; | |
b00b8dae MKL |
4144 | |
4145 | for (i = 0; i < nr_enums; i++) { | |
31d0bc81 AM |
4146 | if (v != enums[i].val) |
4147 | continue; | |
4148 | ||
4149 | btf_show_type_value(show, "%s", | |
4150 | __btf_name_by_offset(btf, | |
4151 | enums[i].name_off)); | |
4152 | ||
4153 | btf_show_end_type(show); | |
4154 | return; | |
b00b8dae MKL |
4155 | } |
4156 | ||
6089fb32 YS |
4157 | if (btf_type_kflag(t)) |
4158 | btf_show_type_value(show, "%d", v); | |
4159 | else | |
4160 | btf_show_type_value(show, "%u", v); | |
31d0bc81 | 4161 | btf_show_end_type(show); |
b00b8dae MKL |
4162 | } |
4163 | ||
69b693f0 MKL |
4164 | static struct btf_kind_operations enum_ops = { |
4165 | .check_meta = btf_enum_check_meta, | |
eb3f595d | 4166 | .resolve = btf_df_resolve, |
179cde8c | 4167 | .check_member = btf_enum_check_member, |
9d5f9f70 | 4168 | .check_kflag_member = btf_enum_check_kflag_member, |
69b693f0 | 4169 | .log_details = btf_enum_log, |
31d0bc81 | 4170 | .show = btf_enum_show, |
69b693f0 MKL |
4171 | }; |
4172 | ||
6089fb32 YS |
4173 | static s32 btf_enum64_check_meta(struct btf_verifier_env *env, |
4174 | const struct btf_type *t, | |
4175 | u32 meta_left) | |
4176 | { | |
4177 | const struct btf_enum64 *enums = btf_type_enum64(t); | |
4178 | struct btf *btf = env->btf; | |
4179 | const char *fmt_str; | |
4180 | u16 i, nr_enums; | |
4181 | u32 meta_needed; | |
4182 | ||
4183 | nr_enums = btf_type_vlen(t); | |
4184 | meta_needed = nr_enums * sizeof(*enums); | |
4185 | ||
4186 | if (meta_left < meta_needed) { | |
4187 | btf_verifier_log_basic(env, t, | |
4188 | "meta_left:%u meta_needed:%u", | |
4189 | meta_left, meta_needed); | |
4190 | return -EINVAL; | |
4191 | } | |
4192 | ||
4193 | if (t->size > 8 || !is_power_of_2(t->size)) { | |
4194 | btf_verifier_log_type(env, t, "Unexpected size"); | |
4195 | return -EINVAL; | |
4196 | } | |
4197 | ||
4198 | /* enum type either no name or a valid one */ | |
4199 | if (t->name_off && | |
4200 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
4201 | btf_verifier_log_type(env, t, "Invalid name"); | |
4202 | return -EINVAL; | |
4203 | } | |
4204 | ||
4205 | btf_verifier_log_type(env, t, NULL); | |
4206 | ||
4207 | for (i = 0; i < nr_enums; i++) { | |
4208 | if (!btf_name_offset_valid(btf, enums[i].name_off)) { | |
4209 | btf_verifier_log(env, "\tInvalid name_offset:%u", | |
4210 | enums[i].name_off); | |
4211 | return -EINVAL; | |
4212 | } | |
4213 | ||
4214 | /* enum member must have a valid name */ | |
4215 | if (!enums[i].name_off || | |
4216 | !btf_name_valid_identifier(btf, enums[i].name_off)) { | |
4217 | btf_verifier_log_type(env, t, "Invalid name"); | |
4218 | return -EINVAL; | |
4219 | } | |
4220 | ||
4221 | if (env->log.level == BPF_LOG_KERNEL) | |
4222 | continue; | |
4223 | ||
4224 | fmt_str = btf_type_kflag(t) ? "\t%s val=%lld\n" : "\t%s val=%llu\n"; | |
4225 | btf_verifier_log(env, fmt_str, | |
4226 | __btf_name_by_offset(btf, enums[i].name_off), | |
4227 | btf_enum64_value(enums + i)); | |
4228 | } | |
4229 | ||
4230 | return meta_needed; | |
4231 | } | |
4232 | ||
4233 | static void btf_enum64_show(const struct btf *btf, const struct btf_type *t, | |
4234 | u32 type_id, void *data, u8 bits_offset, | |
4235 | struct btf_show *show) | |
4236 | { | |
4237 | const struct btf_enum64 *enums = btf_type_enum64(t); | |
4238 | u32 i, nr_enums = btf_type_vlen(t); | |
4239 | void *safe_data; | |
4240 | s64 v; | |
4241 | ||
4242 | safe_data = btf_show_start_type(show, t, type_id, data); | |
4243 | if (!safe_data) | |
4244 | return; | |
4245 | ||
4246 | v = *(u64 *)safe_data; | |
4247 | ||
4248 | for (i = 0; i < nr_enums; i++) { | |
4249 | if (v != btf_enum64_value(enums + i)) | |
4250 | continue; | |
4251 | ||
4252 | btf_show_type_value(show, "%s", | |
4253 | __btf_name_by_offset(btf, | |
4254 | enums[i].name_off)); | |
4255 | ||
4256 | btf_show_end_type(show); | |
4257 | return; | |
4258 | } | |
4259 | ||
4260 | if (btf_type_kflag(t)) | |
4261 | btf_show_type_value(show, "%lld", v); | |
4262 | else | |
4263 | btf_show_type_value(show, "%llu", v); | |
4264 | btf_show_end_type(show); | |
4265 | } | |
4266 | ||
4267 | static struct btf_kind_operations enum64_ops = { | |
4268 | .check_meta = btf_enum64_check_meta, | |
4269 | .resolve = btf_df_resolve, | |
4270 | .check_member = btf_enum_check_member, | |
4271 | .check_kflag_member = btf_enum_check_kflag_member, | |
4272 | .log_details = btf_enum_log, | |
4273 | .show = btf_enum64_show, | |
4274 | }; | |
4275 | ||
2667a262 MKL |
4276 | static s32 btf_func_proto_check_meta(struct btf_verifier_env *env, |
4277 | const struct btf_type *t, | |
4278 | u32 meta_left) | |
4279 | { | |
4280 | u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param); | |
4281 | ||
4282 | if (meta_left < meta_needed) { | |
4283 | btf_verifier_log_basic(env, t, | |
4284 | "meta_left:%u meta_needed:%u", | |
4285 | meta_left, meta_needed); | |
4286 | return -EINVAL; | |
4287 | } | |
4288 | ||
4289 | if (t->name_off) { | |
4290 | btf_verifier_log_type(env, t, "Invalid name"); | |
4291 | return -EINVAL; | |
4292 | } | |
4293 | ||
9d5f9f70 YS |
4294 | if (btf_type_kflag(t)) { |
4295 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4296 | return -EINVAL; | |
4297 | } | |
4298 | ||
2667a262 MKL |
4299 | btf_verifier_log_type(env, t, NULL); |
4300 | ||
4301 | return meta_needed; | |
4302 | } | |
4303 | ||
4304 | static void btf_func_proto_log(struct btf_verifier_env *env, | |
4305 | const struct btf_type *t) | |
4306 | { | |
4307 | const struct btf_param *args = (const struct btf_param *)(t + 1); | |
4308 | u16 nr_args = btf_type_vlen(t), i; | |
4309 | ||
4310 | btf_verifier_log(env, "return=%u args=(", t->type); | |
4311 | if (!nr_args) { | |
4312 | btf_verifier_log(env, "void"); | |
4313 | goto done; | |
4314 | } | |
4315 | ||
4316 | if (nr_args == 1 && !args[0].type) { | |
4317 | /* Only one vararg */ | |
4318 | btf_verifier_log(env, "vararg"); | |
4319 | goto done; | |
4320 | } | |
4321 | ||
4322 | btf_verifier_log(env, "%u %s", args[0].type, | |
23127b33 MKL |
4323 | __btf_name_by_offset(env->btf, |
4324 | args[0].name_off)); | |
2667a262 MKL |
4325 | for (i = 1; i < nr_args - 1; i++) |
4326 | btf_verifier_log(env, ", %u %s", args[i].type, | |
23127b33 MKL |
4327 | __btf_name_by_offset(env->btf, |
4328 | args[i].name_off)); | |
2667a262 MKL |
4329 | |
4330 | if (nr_args > 1) { | |
4331 | const struct btf_param *last_arg = &args[nr_args - 1]; | |
4332 | ||
4333 | if (last_arg->type) | |
4334 | btf_verifier_log(env, ", %u %s", last_arg->type, | |
23127b33 MKL |
4335 | __btf_name_by_offset(env->btf, |
4336 | last_arg->name_off)); | |
2667a262 MKL |
4337 | else |
4338 | btf_verifier_log(env, ", vararg"); | |
4339 | } | |
4340 | ||
4341 | done: | |
4342 | btf_verifier_log(env, ")"); | |
4343 | } | |
4344 | ||
4345 | static struct btf_kind_operations func_proto_ops = { | |
4346 | .check_meta = btf_func_proto_check_meta, | |
4347 | .resolve = btf_df_resolve, | |
4348 | /* | |
4349 | * BTF_KIND_FUNC_PROTO cannot be directly referred by | |
4350 | * a struct's member. | |
4351 | * | |
8fb33b60 | 4352 | * It should be a function pointer instead. |
2667a262 MKL |
4353 | * (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO) |
4354 | * | |
4355 | * Hence, there is no btf_func_check_member(). | |
4356 | */ | |
4357 | .check_member = btf_df_check_member, | |
9d5f9f70 | 4358 | .check_kflag_member = btf_df_check_kflag_member, |
2667a262 | 4359 | .log_details = btf_func_proto_log, |
31d0bc81 | 4360 | .show = btf_df_show, |
2667a262 MKL |
4361 | }; |
4362 | ||
4363 | static s32 btf_func_check_meta(struct btf_verifier_env *env, | |
4364 | const struct btf_type *t, | |
4365 | u32 meta_left) | |
4366 | { | |
4367 | if (!t->name_off || | |
4368 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
4369 | btf_verifier_log_type(env, t, "Invalid name"); | |
4370 | return -EINVAL; | |
4371 | } | |
4372 | ||
51c39bb1 AS |
4373 | if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) { |
4374 | btf_verifier_log_type(env, t, "Invalid func linkage"); | |
2667a262 MKL |
4375 | return -EINVAL; |
4376 | } | |
4377 | ||
9d5f9f70 YS |
4378 | if (btf_type_kflag(t)) { |
4379 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4380 | return -EINVAL; | |
4381 | } | |
4382 | ||
2667a262 MKL |
4383 | btf_verifier_log_type(env, t, NULL); |
4384 | ||
4385 | return 0; | |
4386 | } | |
4387 | ||
d7e7b42f YS |
4388 | static int btf_func_resolve(struct btf_verifier_env *env, |
4389 | const struct resolve_vertex *v) | |
4390 | { | |
4391 | const struct btf_type *t = v->t; | |
4392 | u32 next_type_id = t->type; | |
4393 | int err; | |
4394 | ||
4395 | err = btf_func_check(env, t); | |
4396 | if (err) | |
4397 | return err; | |
4398 | ||
4399 | env_stack_pop_resolved(env, next_type_id, 0); | |
4400 | return 0; | |
4401 | } | |
4402 | ||
2667a262 MKL |
4403 | static struct btf_kind_operations func_ops = { |
4404 | .check_meta = btf_func_check_meta, | |
d7e7b42f | 4405 | .resolve = btf_func_resolve, |
2667a262 | 4406 | .check_member = btf_df_check_member, |
9d5f9f70 | 4407 | .check_kflag_member = btf_df_check_kflag_member, |
2667a262 | 4408 | .log_details = btf_ref_type_log, |
31d0bc81 | 4409 | .show = btf_df_show, |
2667a262 MKL |
4410 | }; |
4411 | ||
1dc92851 DB |
4412 | static s32 btf_var_check_meta(struct btf_verifier_env *env, |
4413 | const struct btf_type *t, | |
4414 | u32 meta_left) | |
4415 | { | |
4416 | const struct btf_var *var; | |
4417 | u32 meta_needed = sizeof(*var); | |
4418 | ||
4419 | if (meta_left < meta_needed) { | |
4420 | btf_verifier_log_basic(env, t, | |
4421 | "meta_left:%u meta_needed:%u", | |
4422 | meta_left, meta_needed); | |
4423 | return -EINVAL; | |
4424 | } | |
4425 | ||
4426 | if (btf_type_vlen(t)) { | |
4427 | btf_verifier_log_type(env, t, "vlen != 0"); | |
4428 | return -EINVAL; | |
4429 | } | |
4430 | ||
4431 | if (btf_type_kflag(t)) { | |
4432 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4433 | return -EINVAL; | |
4434 | } | |
4435 | ||
4436 | if (!t->name_off || | |
9724160b | 4437 | !__btf_name_valid(env->btf, t->name_off)) { |
1dc92851 DB |
4438 | btf_verifier_log_type(env, t, "Invalid name"); |
4439 | return -EINVAL; | |
4440 | } | |
4441 | ||
4442 | /* A var cannot be in type void */ | |
4443 | if (!t->type || !BTF_TYPE_ID_VALID(t->type)) { | |
4444 | btf_verifier_log_type(env, t, "Invalid type_id"); | |
4445 | return -EINVAL; | |
4446 | } | |
4447 | ||
4448 | var = btf_type_var(t); | |
4449 | if (var->linkage != BTF_VAR_STATIC && | |
4450 | var->linkage != BTF_VAR_GLOBAL_ALLOCATED) { | |
4451 | btf_verifier_log_type(env, t, "Linkage not supported"); | |
4452 | return -EINVAL; | |
4453 | } | |
4454 | ||
4455 | btf_verifier_log_type(env, t, NULL); | |
4456 | ||
4457 | return meta_needed; | |
4458 | } | |
4459 | ||
4460 | static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t) | |
4461 | { | |
4462 | const struct btf_var *var = btf_type_var(t); | |
4463 | ||
4464 | btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage); | |
4465 | } | |
4466 | ||
4467 | static const struct btf_kind_operations var_ops = { | |
4468 | .check_meta = btf_var_check_meta, | |
4469 | .resolve = btf_var_resolve, | |
4470 | .check_member = btf_df_check_member, | |
4471 | .check_kflag_member = btf_df_check_kflag_member, | |
4472 | .log_details = btf_var_log, | |
31d0bc81 | 4473 | .show = btf_var_show, |
1dc92851 DB |
4474 | }; |
4475 | ||
4476 | static s32 btf_datasec_check_meta(struct btf_verifier_env *env, | |
4477 | const struct btf_type *t, | |
4478 | u32 meta_left) | |
4479 | { | |
4480 | const struct btf_var_secinfo *vsi; | |
4481 | u64 last_vsi_end_off = 0, sum = 0; | |
4482 | u32 i, meta_needed; | |
4483 | ||
4484 | meta_needed = btf_type_vlen(t) * sizeof(*vsi); | |
4485 | if (meta_left < meta_needed) { | |
4486 | btf_verifier_log_basic(env, t, | |
4487 | "meta_left:%u meta_needed:%u", | |
4488 | meta_left, meta_needed); | |
4489 | return -EINVAL; | |
4490 | } | |
4491 | ||
1dc92851 DB |
4492 | if (!t->size) { |
4493 | btf_verifier_log_type(env, t, "size == 0"); | |
4494 | return -EINVAL; | |
4495 | } | |
4496 | ||
4497 | if (btf_type_kflag(t)) { | |
4498 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4499 | return -EINVAL; | |
4500 | } | |
4501 | ||
4502 | if (!t->name_off || | |
4503 | !btf_name_valid_section(env->btf, t->name_off)) { | |
4504 | btf_verifier_log_type(env, t, "Invalid name"); | |
4505 | return -EINVAL; | |
4506 | } | |
4507 | ||
4508 | btf_verifier_log_type(env, t, NULL); | |
4509 | ||
4510 | for_each_vsi(i, t, vsi) { | |
4511 | /* A var cannot be in type void */ | |
4512 | if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) { | |
4513 | btf_verifier_log_vsi(env, t, vsi, | |
4514 | "Invalid type_id"); | |
4515 | return -EINVAL; | |
4516 | } | |
4517 | ||
4518 | if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) { | |
4519 | btf_verifier_log_vsi(env, t, vsi, | |
4520 | "Invalid offset"); | |
4521 | return -EINVAL; | |
4522 | } | |
4523 | ||
4524 | if (!vsi->size || vsi->size > t->size) { | |
4525 | btf_verifier_log_vsi(env, t, vsi, | |
4526 | "Invalid size"); | |
4527 | return -EINVAL; | |
4528 | } | |
4529 | ||
4530 | last_vsi_end_off = vsi->offset + vsi->size; | |
4531 | if (last_vsi_end_off > t->size) { | |
4532 | btf_verifier_log_vsi(env, t, vsi, | |
4533 | "Invalid offset+size"); | |
4534 | return -EINVAL; | |
4535 | } | |
4536 | ||
4537 | btf_verifier_log_vsi(env, t, vsi, NULL); | |
4538 | sum += vsi->size; | |
4539 | } | |
4540 | ||
4541 | if (t->size < sum) { | |
4542 | btf_verifier_log_type(env, t, "Invalid btf_info size"); | |
4543 | return -EINVAL; | |
4544 | } | |
4545 | ||
4546 | return meta_needed; | |
4547 | } | |
4548 | ||
4549 | static int btf_datasec_resolve(struct btf_verifier_env *env, | |
4550 | const struct resolve_vertex *v) | |
4551 | { | |
4552 | const struct btf_var_secinfo *vsi; | |
4553 | struct btf *btf = env->btf; | |
4554 | u16 i; | |
4555 | ||
9b459804 | 4556 | env->resolve_mode = RESOLVE_TBD; |
1dc92851 DB |
4557 | for_each_vsi_from(i, v->next_member, v->t, vsi) { |
4558 | u32 var_type_id = vsi->type, type_id, type_size = 0; | |
4559 | const struct btf_type *var_type = btf_type_by_id(env->btf, | |
4560 | var_type_id); | |
4561 | if (!var_type || !btf_type_is_var(var_type)) { | |
4562 | btf_verifier_log_vsi(env, v->t, vsi, | |
4563 | "Not a VAR kind member"); | |
4564 | return -EINVAL; | |
4565 | } | |
4566 | ||
4567 | if (!env_type_is_resolve_sink(env, var_type) && | |
4568 | !env_type_is_resolved(env, var_type_id)) { | |
4569 | env_stack_set_next_member(env, i + 1); | |
4570 | return env_stack_push(env, var_type, var_type_id); | |
4571 | } | |
4572 | ||
4573 | type_id = var_type->type; | |
4574 | if (!btf_type_id_size(btf, &type_id, &type_size)) { | |
4575 | btf_verifier_log_vsi(env, v->t, vsi, "Invalid type"); | |
4576 | return -EINVAL; | |
4577 | } | |
4578 | ||
4579 | if (vsi->size < type_size) { | |
4580 | btf_verifier_log_vsi(env, v->t, vsi, "Invalid size"); | |
4581 | return -EINVAL; | |
4582 | } | |
4583 | } | |
4584 | ||
4585 | env_stack_pop_resolved(env, 0, 0); | |
4586 | return 0; | |
4587 | } | |
4588 | ||
4589 | static void btf_datasec_log(struct btf_verifier_env *env, | |
4590 | const struct btf_type *t) | |
4591 | { | |
4592 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
4593 | } | |
4594 | ||
31d0bc81 AM |
4595 | static void btf_datasec_show(const struct btf *btf, |
4596 | const struct btf_type *t, u32 type_id, | |
4597 | void *data, u8 bits_offset, | |
4598 | struct btf_show *show) | |
1dc92851 DB |
4599 | { |
4600 | const struct btf_var_secinfo *vsi; | |
4601 | const struct btf_type *var; | |
4602 | u32 i; | |
4603 | ||
31d0bc81 AM |
4604 | if (!btf_show_start_type(show, t, type_id, data)) |
4605 | return; | |
4606 | ||
4607 | btf_show_type_value(show, "section (\"%s\") = {", | |
4608 | __btf_name_by_offset(btf, t->name_off)); | |
1dc92851 DB |
4609 | for_each_vsi(i, t, vsi) { |
4610 | var = btf_type_by_id(btf, vsi->type); | |
4611 | if (i) | |
31d0bc81 AM |
4612 | btf_show(show, ","); |
4613 | btf_type_ops(var)->show(btf, var, vsi->type, | |
4614 | data + vsi->offset, bits_offset, show); | |
1dc92851 | 4615 | } |
31d0bc81 | 4616 | btf_show_end_type(show); |
1dc92851 DB |
4617 | } |
4618 | ||
4619 | static const struct btf_kind_operations datasec_ops = { | |
4620 | .check_meta = btf_datasec_check_meta, | |
4621 | .resolve = btf_datasec_resolve, | |
4622 | .check_member = btf_df_check_member, | |
4623 | .check_kflag_member = btf_df_check_kflag_member, | |
4624 | .log_details = btf_datasec_log, | |
31d0bc81 | 4625 | .show = btf_datasec_show, |
1dc92851 DB |
4626 | }; |
4627 | ||
b1828f0b IL |
4628 | static s32 btf_float_check_meta(struct btf_verifier_env *env, |
4629 | const struct btf_type *t, | |
4630 | u32 meta_left) | |
4631 | { | |
4632 | if (btf_type_vlen(t)) { | |
4633 | btf_verifier_log_type(env, t, "vlen != 0"); | |
4634 | return -EINVAL; | |
4635 | } | |
4636 | ||
4637 | if (btf_type_kflag(t)) { | |
4638 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4639 | return -EINVAL; | |
4640 | } | |
4641 | ||
4642 | if (t->size != 2 && t->size != 4 && t->size != 8 && t->size != 12 && | |
4643 | t->size != 16) { | |
4644 | btf_verifier_log_type(env, t, "Invalid type_size"); | |
4645 | return -EINVAL; | |
4646 | } | |
4647 | ||
4648 | btf_verifier_log_type(env, t, NULL); | |
4649 | ||
4650 | return 0; | |
4651 | } | |
4652 | ||
4653 | static int btf_float_check_member(struct btf_verifier_env *env, | |
4654 | const struct btf_type *struct_type, | |
4655 | const struct btf_member *member, | |
4656 | const struct btf_type *member_type) | |
4657 | { | |
4658 | u64 start_offset_bytes; | |
4659 | u64 end_offset_bytes; | |
4660 | u64 misalign_bits; | |
4661 | u64 align_bytes; | |
4662 | u64 align_bits; | |
4663 | ||
4664 | /* Different architectures have different alignment requirements, so | |
4665 | * here we check only for the reasonable minimum. This way we ensure | |
4666 | * that types after CO-RE can pass the kernel BTF verifier. | |
4667 | */ | |
4668 | align_bytes = min_t(u64, sizeof(void *), member_type->size); | |
4669 | align_bits = align_bytes * BITS_PER_BYTE; | |
4670 | div64_u64_rem(member->offset, align_bits, &misalign_bits); | |
4671 | if (misalign_bits) { | |
4672 | btf_verifier_log_member(env, struct_type, member, | |
4673 | "Member is not properly aligned"); | |
4674 | return -EINVAL; | |
4675 | } | |
4676 | ||
4677 | start_offset_bytes = member->offset / BITS_PER_BYTE; | |
4678 | end_offset_bytes = start_offset_bytes + member_type->size; | |
4679 | if (end_offset_bytes > struct_type->size) { | |
4680 | btf_verifier_log_member(env, struct_type, member, | |
4681 | "Member exceeds struct_size"); | |
4682 | return -EINVAL; | |
4683 | } | |
4684 | ||
4685 | return 0; | |
4686 | } | |
4687 | ||
4688 | static void btf_float_log(struct btf_verifier_env *env, | |
4689 | const struct btf_type *t) | |
4690 | { | |
4691 | btf_verifier_log(env, "size=%u", t->size); | |
4692 | } | |
4693 | ||
4694 | static const struct btf_kind_operations float_ops = { | |
4695 | .check_meta = btf_float_check_meta, | |
4696 | .resolve = btf_df_resolve, | |
4697 | .check_member = btf_float_check_member, | |
4698 | .check_kflag_member = btf_generic_check_kflag_member, | |
4699 | .log_details = btf_float_log, | |
4700 | .show = btf_df_show, | |
4701 | }; | |
4702 | ||
223f903e | 4703 | static s32 btf_decl_tag_check_meta(struct btf_verifier_env *env, |
b5ea834d YS |
4704 | const struct btf_type *t, |
4705 | u32 meta_left) | |
4706 | { | |
223f903e | 4707 | const struct btf_decl_tag *tag; |
b5ea834d YS |
4708 | u32 meta_needed = sizeof(*tag); |
4709 | s32 component_idx; | |
4710 | const char *value; | |
4711 | ||
4712 | if (meta_left < meta_needed) { | |
4713 | btf_verifier_log_basic(env, t, | |
4714 | "meta_left:%u meta_needed:%u", | |
4715 | meta_left, meta_needed); | |
4716 | return -EINVAL; | |
4717 | } | |
4718 | ||
4719 | value = btf_name_by_offset(env->btf, t->name_off); | |
4720 | if (!value || !value[0]) { | |
4721 | btf_verifier_log_type(env, t, "Invalid value"); | |
4722 | return -EINVAL; | |
4723 | } | |
4724 | ||
4725 | if (btf_type_vlen(t)) { | |
4726 | btf_verifier_log_type(env, t, "vlen != 0"); | |
4727 | return -EINVAL; | |
4728 | } | |
4729 | ||
4730 | if (btf_type_kflag(t)) { | |
4731 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4732 | return -EINVAL; | |
4733 | } | |
4734 | ||
223f903e | 4735 | component_idx = btf_type_decl_tag(t)->component_idx; |
b5ea834d YS |
4736 | if (component_idx < -1) { |
4737 | btf_verifier_log_type(env, t, "Invalid component_idx"); | |
4738 | return -EINVAL; | |
4739 | } | |
4740 | ||
4741 | btf_verifier_log_type(env, t, NULL); | |
4742 | ||
4743 | return meta_needed; | |
4744 | } | |
4745 | ||
223f903e | 4746 | static int btf_decl_tag_resolve(struct btf_verifier_env *env, |
b5ea834d YS |
4747 | const struct resolve_vertex *v) |
4748 | { | |
4749 | const struct btf_type *next_type; | |
4750 | const struct btf_type *t = v->t; | |
4751 | u32 next_type_id = t->type; | |
4752 | struct btf *btf = env->btf; | |
4753 | s32 component_idx; | |
4754 | u32 vlen; | |
4755 | ||
4756 | next_type = btf_type_by_id(btf, next_type_id); | |
223f903e | 4757 | if (!next_type || !btf_type_is_decl_tag_target(next_type)) { |
b5ea834d YS |
4758 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
4759 | return -EINVAL; | |
4760 | } | |
4761 | ||
4762 | if (!env_type_is_resolve_sink(env, next_type) && | |
4763 | !env_type_is_resolved(env, next_type_id)) | |
4764 | return env_stack_push(env, next_type, next_type_id); | |
4765 | ||
223f903e | 4766 | component_idx = btf_type_decl_tag(t)->component_idx; |
b5ea834d | 4767 | if (component_idx != -1) { |
bd16dee6 | 4768 | if (btf_type_is_var(next_type) || btf_type_is_typedef(next_type)) { |
b5ea834d YS |
4769 | btf_verifier_log_type(env, v->t, "Invalid component_idx"); |
4770 | return -EINVAL; | |
4771 | } | |
4772 | ||
4773 | if (btf_type_is_struct(next_type)) { | |
4774 | vlen = btf_type_vlen(next_type); | |
4775 | } else { | |
4776 | /* next_type should be a function */ | |
4777 | next_type = btf_type_by_id(btf, next_type->type); | |
4778 | vlen = btf_type_vlen(next_type); | |
4779 | } | |
4780 | ||
4781 | if ((u32)component_idx >= vlen) { | |
4782 | btf_verifier_log_type(env, v->t, "Invalid component_idx"); | |
4783 | return -EINVAL; | |
4784 | } | |
4785 | } | |
4786 | ||
4787 | env_stack_pop_resolved(env, next_type_id, 0); | |
4788 | ||
4789 | return 0; | |
4790 | } | |
4791 | ||
223f903e | 4792 | static void btf_decl_tag_log(struct btf_verifier_env *env, const struct btf_type *t) |
b5ea834d YS |
4793 | { |
4794 | btf_verifier_log(env, "type=%u component_idx=%d", t->type, | |
223f903e | 4795 | btf_type_decl_tag(t)->component_idx); |
b5ea834d YS |
4796 | } |
4797 | ||
223f903e YS |
4798 | static const struct btf_kind_operations decl_tag_ops = { |
4799 | .check_meta = btf_decl_tag_check_meta, | |
4800 | .resolve = btf_decl_tag_resolve, | |
b5ea834d YS |
4801 | .check_member = btf_df_check_member, |
4802 | .check_kflag_member = btf_df_check_kflag_member, | |
223f903e | 4803 | .log_details = btf_decl_tag_log, |
b5ea834d YS |
4804 | .show = btf_df_show, |
4805 | }; | |
4806 | ||
2667a262 MKL |
4807 | static int btf_func_proto_check(struct btf_verifier_env *env, |
4808 | const struct btf_type *t) | |
4809 | { | |
4810 | const struct btf_type *ret_type; | |
4811 | const struct btf_param *args; | |
4812 | const struct btf *btf; | |
4813 | u16 nr_args, i; | |
4814 | int err; | |
4815 | ||
4816 | btf = env->btf; | |
4817 | args = (const struct btf_param *)(t + 1); | |
4818 | nr_args = btf_type_vlen(t); | |
4819 | ||
4820 | /* Check func return type which could be "void" (t->type == 0) */ | |
4821 | if (t->type) { | |
4822 | u32 ret_type_id = t->type; | |
4823 | ||
4824 | ret_type = btf_type_by_id(btf, ret_type_id); | |
4825 | if (!ret_type) { | |
4826 | btf_verifier_log_type(env, t, "Invalid return type"); | |
4827 | return -EINVAL; | |
4828 | } | |
4829 | ||
ea68376c SF |
4830 | if (btf_type_is_resolve_source_only(ret_type)) { |
4831 | btf_verifier_log_type(env, t, "Invalid return type"); | |
4832 | return -EINVAL; | |
4833 | } | |
4834 | ||
2667a262 MKL |
4835 | if (btf_type_needs_resolve(ret_type) && |
4836 | !env_type_is_resolved(env, ret_type_id)) { | |
4837 | err = btf_resolve(env, ret_type, ret_type_id); | |
4838 | if (err) | |
4839 | return err; | |
4840 | } | |
4841 | ||
4842 | /* Ensure the return type is a type that has a size */ | |
4843 | if (!btf_type_id_size(btf, &ret_type_id, NULL)) { | |
4844 | btf_verifier_log_type(env, t, "Invalid return type"); | |
4845 | return -EINVAL; | |
4846 | } | |
4847 | } | |
4848 | ||
4849 | if (!nr_args) | |
4850 | return 0; | |
4851 | ||
4852 | /* Last func arg type_id could be 0 if it is a vararg */ | |
4853 | if (!args[nr_args - 1].type) { | |
4854 | if (args[nr_args - 1].name_off) { | |
4855 | btf_verifier_log_type(env, t, "Invalid arg#%u", | |
4856 | nr_args); | |
4857 | return -EINVAL; | |
4858 | } | |
4859 | nr_args--; | |
4860 | } | |
4861 | ||
2667a262 MKL |
4862 | for (i = 0; i < nr_args; i++) { |
4863 | const struct btf_type *arg_type; | |
4864 | u32 arg_type_id; | |
4865 | ||
4866 | arg_type_id = args[i].type; | |
4867 | arg_type = btf_type_by_id(btf, arg_type_id); | |
4868 | if (!arg_type) { | |
4869 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
5bad3587 | 4870 | return -EINVAL; |
2667a262 MKL |
4871 | } |
4872 | ||
f17472d4 SF |
4873 | if (btf_type_is_resolve_source_only(arg_type)) { |
4874 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
4875 | return -EINVAL; | |
4876 | } | |
4877 | ||
2667a262 MKL |
4878 | if (args[i].name_off && |
4879 | (!btf_name_offset_valid(btf, args[i].name_off) || | |
4880 | !btf_name_valid_identifier(btf, args[i].name_off))) { | |
4881 | btf_verifier_log_type(env, t, | |
4882 | "Invalid arg#%u", i + 1); | |
5bad3587 | 4883 | return -EINVAL; |
2667a262 MKL |
4884 | } |
4885 | ||
4886 | if (btf_type_needs_resolve(arg_type) && | |
4887 | !env_type_is_resolved(env, arg_type_id)) { | |
4888 | err = btf_resolve(env, arg_type, arg_type_id); | |
4889 | if (err) | |
5bad3587 | 4890 | return err; |
2667a262 MKL |
4891 | } |
4892 | ||
4893 | if (!btf_type_id_size(btf, &arg_type_id, NULL)) { | |
4894 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
5bad3587 | 4895 | return -EINVAL; |
2667a262 MKL |
4896 | } |
4897 | } | |
4898 | ||
5bad3587 | 4899 | return 0; |
2667a262 MKL |
4900 | } |
4901 | ||
4902 | static int btf_func_check(struct btf_verifier_env *env, | |
4903 | const struct btf_type *t) | |
4904 | { | |
4905 | const struct btf_type *proto_type; | |
4906 | const struct btf_param *args; | |
4907 | const struct btf *btf; | |
4908 | u16 nr_args, i; | |
4909 | ||
4910 | btf = env->btf; | |
4911 | proto_type = btf_type_by_id(btf, t->type); | |
4912 | ||
4913 | if (!proto_type || !btf_type_is_func_proto(proto_type)) { | |
4914 | btf_verifier_log_type(env, t, "Invalid type_id"); | |
4915 | return -EINVAL; | |
4916 | } | |
4917 | ||
4918 | args = (const struct btf_param *)(proto_type + 1); | |
4919 | nr_args = btf_type_vlen(proto_type); | |
4920 | for (i = 0; i < nr_args; i++) { | |
4921 | if (!args[i].name_off && args[i].type) { | |
4922 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
4923 | return -EINVAL; | |
4924 | } | |
4925 | } | |
4926 | ||
4927 | return 0; | |
4928 | } | |
4929 | ||
69b693f0 MKL |
4930 | static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = { |
4931 | [BTF_KIND_INT] = &int_ops, | |
4932 | [BTF_KIND_PTR] = &ptr_ops, | |
4933 | [BTF_KIND_ARRAY] = &array_ops, | |
4934 | [BTF_KIND_STRUCT] = &struct_ops, | |
4935 | [BTF_KIND_UNION] = &struct_ops, | |
4936 | [BTF_KIND_ENUM] = &enum_ops, | |
4937 | [BTF_KIND_FWD] = &fwd_ops, | |
4938 | [BTF_KIND_TYPEDEF] = &modifier_ops, | |
4939 | [BTF_KIND_VOLATILE] = &modifier_ops, | |
4940 | [BTF_KIND_CONST] = &modifier_ops, | |
4941 | [BTF_KIND_RESTRICT] = &modifier_ops, | |
2667a262 MKL |
4942 | [BTF_KIND_FUNC] = &func_ops, |
4943 | [BTF_KIND_FUNC_PROTO] = &func_proto_ops, | |
1dc92851 DB |
4944 | [BTF_KIND_VAR] = &var_ops, |
4945 | [BTF_KIND_DATASEC] = &datasec_ops, | |
b1828f0b | 4946 | [BTF_KIND_FLOAT] = &float_ops, |
223f903e | 4947 | [BTF_KIND_DECL_TAG] = &decl_tag_ops, |
8c42d2fa | 4948 | [BTF_KIND_TYPE_TAG] = &modifier_ops, |
6089fb32 | 4949 | [BTF_KIND_ENUM64] = &enum64_ops, |
69b693f0 MKL |
4950 | }; |
4951 | ||
4952 | static s32 btf_check_meta(struct btf_verifier_env *env, | |
4953 | const struct btf_type *t, | |
4954 | u32 meta_left) | |
4955 | { | |
4956 | u32 saved_meta_left = meta_left; | |
4957 | s32 var_meta_size; | |
4958 | ||
4959 | if (meta_left < sizeof(*t)) { | |
4960 | btf_verifier_log(env, "[%u] meta_left:%u meta_needed:%zu", | |
4961 | env->log_type_id, meta_left, sizeof(*t)); | |
4962 | return -EINVAL; | |
4963 | } | |
4964 | meta_left -= sizeof(*t); | |
4965 | ||
aea2f7b8 MKL |
4966 | if (t->info & ~BTF_INFO_MASK) { |
4967 | btf_verifier_log(env, "[%u] Invalid btf_info:%x", | |
4968 | env->log_type_id, t->info); | |
4969 | return -EINVAL; | |
4970 | } | |
4971 | ||
69b693f0 MKL |
4972 | if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX || |
4973 | BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) { | |
4974 | btf_verifier_log(env, "[%u] Invalid kind:%u", | |
4975 | env->log_type_id, BTF_INFO_KIND(t->info)); | |
4976 | return -EINVAL; | |
4977 | } | |
4978 | ||
fbcf93eb | 4979 | if (!btf_name_offset_valid(env->btf, t->name_off)) { |
69b693f0 | 4980 | btf_verifier_log(env, "[%u] Invalid name_offset:%u", |
fbcf93eb | 4981 | env->log_type_id, t->name_off); |
69b693f0 MKL |
4982 | return -EINVAL; |
4983 | } | |
4984 | ||
4985 | var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left); | |
4986 | if (var_meta_size < 0) | |
4987 | return var_meta_size; | |
4988 | ||
4989 | meta_left -= var_meta_size; | |
4990 | ||
4991 | return saved_meta_left - meta_left; | |
4992 | } | |
4993 | ||
4994 | static int btf_check_all_metas(struct btf_verifier_env *env) | |
4995 | { | |
4996 | struct btf *btf = env->btf; | |
4997 | struct btf_header *hdr; | |
4998 | void *cur, *end; | |
4999 | ||
f80442a4 | 5000 | hdr = &btf->hdr; |
69b693f0 | 5001 | cur = btf->nohdr_data + hdr->type_off; |
4b1c5d91 | 5002 | end = cur + hdr->type_len; |
69b693f0 | 5003 | |
951bb646 | 5004 | env->log_type_id = btf->base_btf ? btf->start_id : 1; |
69b693f0 MKL |
5005 | while (cur < end) { |
5006 | struct btf_type *t = cur; | |
5007 | s32 meta_size; | |
5008 | ||
5009 | meta_size = btf_check_meta(env, t, end - cur); | |
5010 | if (meta_size < 0) | |
5011 | return meta_size; | |
5012 | ||
5013 | btf_add_type(env, t); | |
5014 | cur += meta_size; | |
5015 | env->log_type_id++; | |
5016 | } | |
5017 | ||
5018 | return 0; | |
5019 | } | |
5020 | ||
eb3f595d MKL |
5021 | static bool btf_resolve_valid(struct btf_verifier_env *env, |
5022 | const struct btf_type *t, | |
5023 | u32 type_id) | |
5024 | { | |
5025 | struct btf *btf = env->btf; | |
5026 | ||
5027 | if (!env_type_is_resolved(env, type_id)) | |
5028 | return false; | |
5029 | ||
1dc92851 | 5030 | if (btf_type_is_struct(t) || btf_type_is_datasec(t)) |
951bb646 AN |
5031 | return !btf_resolved_type_id(btf, type_id) && |
5032 | !btf_resolved_type_size(btf, type_id); | |
eb3f595d | 5033 | |
d7e7b42f | 5034 | if (btf_type_is_decl_tag(t) || btf_type_is_func(t)) |
b5ea834d YS |
5035 | return btf_resolved_type_id(btf, type_id) && |
5036 | !btf_resolved_type_size(btf, type_id); | |
5037 | ||
1dc92851 DB |
5038 | if (btf_type_is_modifier(t) || btf_type_is_ptr(t) || |
5039 | btf_type_is_var(t)) { | |
eb3f595d | 5040 | t = btf_type_id_resolve(btf, &type_id); |
1dc92851 DB |
5041 | return t && |
5042 | !btf_type_is_modifier(t) && | |
5043 | !btf_type_is_var(t) && | |
5044 | !btf_type_is_datasec(t); | |
eb3f595d MKL |
5045 | } |
5046 | ||
5047 | if (btf_type_is_array(t)) { | |
5048 | const struct btf_array *array = btf_type_array(t); | |
5049 | const struct btf_type *elem_type; | |
5050 | u32 elem_type_id = array->type; | |
5051 | u32 elem_size; | |
5052 | ||
5053 | elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); | |
5054 | return elem_type && !btf_type_is_modifier(elem_type) && | |
5055 | (array->nelems * elem_size == | |
951bb646 | 5056 | btf_resolved_type_size(btf, type_id)); |
eb3f595d MKL |
5057 | } |
5058 | ||
5059 | return false; | |
5060 | } | |
5061 | ||
2667a262 MKL |
5062 | static int btf_resolve(struct btf_verifier_env *env, |
5063 | const struct btf_type *t, u32 type_id) | |
5064 | { | |
5065 | u32 save_log_type_id = env->log_type_id; | |
5066 | const struct resolve_vertex *v; | |
5067 | int err = 0; | |
5068 | ||
5069 | env->resolve_mode = RESOLVE_TBD; | |
5070 | env_stack_push(env, t, type_id); | |
5071 | while (!err && (v = env_stack_peak(env))) { | |
5072 | env->log_type_id = v->type_id; | |
5073 | err = btf_type_ops(v->t)->resolve(env, v); | |
5074 | } | |
5075 | ||
5076 | env->log_type_id = type_id; | |
5077 | if (err == -E2BIG) { | |
5078 | btf_verifier_log_type(env, t, | |
5079 | "Exceeded max resolving depth:%u", | |
5080 | MAX_RESOLVE_DEPTH); | |
5081 | } else if (err == -EEXIST) { | |
5082 | btf_verifier_log_type(env, t, "Loop detected"); | |
5083 | } | |
5084 | ||
5085 | /* Final sanity check */ | |
5086 | if (!err && !btf_resolve_valid(env, t, type_id)) { | |
5087 | btf_verifier_log_type(env, t, "Invalid resolve state"); | |
5088 | err = -EINVAL; | |
5089 | } | |
5090 | ||
5091 | env->log_type_id = save_log_type_id; | |
5092 | return err; | |
5093 | } | |
5094 | ||
eb3f595d MKL |
5095 | static int btf_check_all_types(struct btf_verifier_env *env) |
5096 | { | |
5097 | struct btf *btf = env->btf; | |
951bb646 AN |
5098 | const struct btf_type *t; |
5099 | u32 type_id, i; | |
eb3f595d MKL |
5100 | int err; |
5101 | ||
5102 | err = env_resolve_init(env); | |
5103 | if (err) | |
5104 | return err; | |
5105 | ||
5106 | env->phase++; | |
951bb646 AN |
5107 | for (i = btf->base_btf ? 0 : 1; i < btf->nr_types; i++) { |
5108 | type_id = btf->start_id + i; | |
5109 | t = btf_type_by_id(btf, type_id); | |
eb3f595d MKL |
5110 | |
5111 | env->log_type_id = type_id; | |
5112 | if (btf_type_needs_resolve(t) && | |
5113 | !env_type_is_resolved(env, type_id)) { | |
5114 | err = btf_resolve(env, t, type_id); | |
5115 | if (err) | |
5116 | return err; | |
5117 | } | |
5118 | ||
2667a262 MKL |
5119 | if (btf_type_is_func_proto(t)) { |
5120 | err = btf_func_proto_check(env, t); | |
5121 | if (err) | |
5122 | return err; | |
5123 | } | |
eb3f595d MKL |
5124 | } |
5125 | ||
5126 | return 0; | |
5127 | } | |
5128 | ||
69b693f0 MKL |
5129 | static int btf_parse_type_sec(struct btf_verifier_env *env) |
5130 | { | |
f80442a4 | 5131 | const struct btf_header *hdr = &env->btf->hdr; |
eb3f595d MKL |
5132 | int err; |
5133 | ||
f80442a4 MKL |
5134 | /* Type section must align to 4 bytes */ |
5135 | if (hdr->type_off & (sizeof(u32) - 1)) { | |
5136 | btf_verifier_log(env, "Unaligned type_off"); | |
5137 | return -EINVAL; | |
5138 | } | |
5139 | ||
951bb646 | 5140 | if (!env->btf->base_btf && !hdr->type_len) { |
f80442a4 MKL |
5141 | btf_verifier_log(env, "No type found"); |
5142 | return -EINVAL; | |
5143 | } | |
5144 | ||
eb3f595d MKL |
5145 | err = btf_check_all_metas(env); |
5146 | if (err) | |
5147 | return err; | |
5148 | ||
5149 | return btf_check_all_types(env); | |
69b693f0 MKL |
5150 | } |
5151 | ||
5152 | static int btf_parse_str_sec(struct btf_verifier_env *env) | |
5153 | { | |
5154 | const struct btf_header *hdr; | |
5155 | struct btf *btf = env->btf; | |
5156 | const char *start, *end; | |
5157 | ||
f80442a4 | 5158 | hdr = &btf->hdr; |
69b693f0 MKL |
5159 | start = btf->nohdr_data + hdr->str_off; |
5160 | end = start + hdr->str_len; | |
5161 | ||
f80442a4 MKL |
5162 | if (end != btf->data + btf->data_size) { |
5163 | btf_verifier_log(env, "String section is not at the end"); | |
5164 | return -EINVAL; | |
5165 | } | |
5166 | ||
951bb646 AN |
5167 | btf->strings = start; |
5168 | ||
5169 | if (btf->base_btf && !hdr->str_len) | |
5170 | return 0; | |
5171 | if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET || end[-1]) { | |
5172 | btf_verifier_log(env, "Invalid string section"); | |
5173 | return -EINVAL; | |
5174 | } | |
5175 | if (!btf->base_btf && start[0]) { | |
69b693f0 MKL |
5176 | btf_verifier_log(env, "Invalid string section"); |
5177 | return -EINVAL; | |
5178 | } | |
69b693f0 MKL |
5179 | |
5180 | return 0; | |
5181 | } | |
5182 | ||
f80442a4 MKL |
5183 | static const size_t btf_sec_info_offset[] = { |
5184 | offsetof(struct btf_header, type_off), | |
5185 | offsetof(struct btf_header, str_off), | |
5186 | }; | |
5187 | ||
5188 | static int btf_sec_info_cmp(const void *a, const void *b) | |
69b693f0 | 5189 | { |
f80442a4 MKL |
5190 | const struct btf_sec_info *x = a; |
5191 | const struct btf_sec_info *y = b; | |
5192 | ||
5193 | return (int)(x->off - y->off) ? : (int)(x->len - y->len); | |
5194 | } | |
5195 | ||
5196 | static int btf_check_sec_info(struct btf_verifier_env *env, | |
5197 | u32 btf_data_size) | |
5198 | { | |
a2889a4c | 5199 | struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)]; |
f80442a4 | 5200 | u32 total, expected_total, i; |
69b693f0 | 5201 | const struct btf_header *hdr; |
f80442a4 MKL |
5202 | const struct btf *btf; |
5203 | ||
5204 | btf = env->btf; | |
5205 | hdr = &btf->hdr; | |
5206 | ||
5207 | /* Populate the secs from hdr */ | |
a2889a4c | 5208 | for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) |
f80442a4 MKL |
5209 | secs[i] = *(struct btf_sec_info *)((void *)hdr + |
5210 | btf_sec_info_offset[i]); | |
5211 | ||
a2889a4c MKL |
5212 | sort(secs, ARRAY_SIZE(btf_sec_info_offset), |
5213 | sizeof(struct btf_sec_info), btf_sec_info_cmp, NULL); | |
f80442a4 MKL |
5214 | |
5215 | /* Check for gaps and overlap among sections */ | |
5216 | total = 0; | |
5217 | expected_total = btf_data_size - hdr->hdr_len; | |
a2889a4c | 5218 | for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) { |
f80442a4 MKL |
5219 | if (expected_total < secs[i].off) { |
5220 | btf_verifier_log(env, "Invalid section offset"); | |
5221 | return -EINVAL; | |
5222 | } | |
5223 | if (total < secs[i].off) { | |
5224 | /* gap */ | |
5225 | btf_verifier_log(env, "Unsupported section found"); | |
5226 | return -EINVAL; | |
5227 | } | |
5228 | if (total > secs[i].off) { | |
5229 | btf_verifier_log(env, "Section overlap found"); | |
5230 | return -EINVAL; | |
5231 | } | |
5232 | if (expected_total - total < secs[i].len) { | |
5233 | btf_verifier_log(env, | |
5234 | "Total section length too long"); | |
5235 | return -EINVAL; | |
5236 | } | |
5237 | total += secs[i].len; | |
5238 | } | |
5239 | ||
5240 | /* There is data other than hdr and known sections */ | |
5241 | if (expected_total != total) { | |
5242 | btf_verifier_log(env, "Unsupported section found"); | |
5243 | return -EINVAL; | |
5244 | } | |
5245 | ||
5246 | return 0; | |
5247 | } | |
5248 | ||
4a6998af | 5249 | static int btf_parse_hdr(struct btf_verifier_env *env) |
f80442a4 | 5250 | { |
4a6998af | 5251 | u32 hdr_len, hdr_copy, btf_data_size; |
f80442a4 | 5252 | const struct btf_header *hdr; |
f80442a4 | 5253 | struct btf *btf; |
69b693f0 | 5254 | |
f80442a4 | 5255 | btf = env->btf; |
4a6998af | 5256 | btf_data_size = btf->data_size; |
f80442a4 | 5257 | |
583669ab | 5258 | if (btf_data_size < offsetofend(struct btf_header, hdr_len)) { |
f80442a4 MKL |
5259 | btf_verifier_log(env, "hdr_len not found"); |
5260 | return -EINVAL; | |
5261 | } | |
5262 | ||
4a6998af ML |
5263 | hdr = btf->data; |
5264 | hdr_len = hdr->hdr_len; | |
f80442a4 | 5265 | if (btf_data_size < hdr_len) { |
69b693f0 MKL |
5266 | btf_verifier_log(env, "btf_header not found"); |
5267 | return -EINVAL; | |
5268 | } | |
5269 | ||
4a6998af ML |
5270 | /* Ensure the unsupported header fields are zero */ |
5271 | if (hdr_len > sizeof(btf->hdr)) { | |
5272 | u8 *expected_zero = btf->data + sizeof(btf->hdr); | |
5273 | u8 *end = btf->data + hdr_len; | |
5274 | ||
5275 | for (; expected_zero < end; expected_zero++) { | |
5276 | if (*expected_zero) { | |
5277 | btf_verifier_log(env, "Unsupported btf_header"); | |
5278 | return -E2BIG; | |
5279 | } | |
5280 | } | |
f80442a4 MKL |
5281 | } |
5282 | ||
5283 | hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr)); | |
4a6998af | 5284 | memcpy(&btf->hdr, btf->data, hdr_copy); |
f80442a4 MKL |
5285 | |
5286 | hdr = &btf->hdr; | |
5287 | ||
5288 | btf_verifier_log_hdr(env, btf_data_size); | |
69b693f0 | 5289 | |
69b693f0 MKL |
5290 | if (hdr->magic != BTF_MAGIC) { |
5291 | btf_verifier_log(env, "Invalid magic"); | |
5292 | return -EINVAL; | |
5293 | } | |
5294 | ||
5295 | if (hdr->version != BTF_VERSION) { | |
5296 | btf_verifier_log(env, "Unsupported version"); | |
5297 | return -ENOTSUPP; | |
5298 | } | |
5299 | ||
5300 | if (hdr->flags) { | |
5301 | btf_verifier_log(env, "Unsupported flags"); | |
5302 | return -ENOTSUPP; | |
5303 | } | |
5304 | ||
bcc5e616 | 5305 | if (!btf->base_btf && btf_data_size == hdr->hdr_len) { |
69b693f0 MKL |
5306 | btf_verifier_log(env, "No data"); |
5307 | return -EINVAL; | |
5308 | } | |
5309 | ||
3a74904c | 5310 | return btf_check_sec_info(env, btf_data_size); |
69b693f0 MKL |
5311 | } |
5312 | ||
8ffa5cc1 KKD |
5313 | static const char *alloc_obj_fields[] = { |
5314 | "bpf_spin_lock", | |
5315 | "bpf_list_head", | |
5316 | "bpf_list_node", | |
9c395c1b DM |
5317 | "bpf_rb_root", |
5318 | "bpf_rb_node", | |
d54730b5 | 5319 | "bpf_refcount", |
8ffa5cc1 KKD |
5320 | }; |
5321 | ||
5322 | static struct btf_struct_metas * | |
5323 | btf_parse_struct_metas(struct bpf_verifier_log *log, struct btf *btf) | |
5324 | { | |
5325 | union { | |
5326 | struct btf_id_set set; | |
5327 | struct { | |
5328 | u32 _cnt; | |
5329 | u32 _ids[ARRAY_SIZE(alloc_obj_fields)]; | |
5330 | } _arr; | |
5331 | } aof; | |
5332 | struct btf_struct_metas *tab = NULL; | |
5333 | int i, n, id, ret; | |
5334 | ||
5335 | BUILD_BUG_ON(offsetof(struct btf_id_set, cnt) != 0); | |
5336 | BUILD_BUG_ON(sizeof(struct btf_id_set) != sizeof(u32)); | |
5337 | ||
5338 | memset(&aof, 0, sizeof(aof)); | |
5339 | for (i = 0; i < ARRAY_SIZE(alloc_obj_fields); i++) { | |
5340 | /* Try to find whether this special type exists in user BTF, and | |
5341 | * if so remember its ID so we can easily find it among members | |
5342 | * of structs that we iterate in the next loop. | |
5343 | */ | |
5344 | id = btf_find_by_name_kind(btf, alloc_obj_fields[i], BTF_KIND_STRUCT); | |
5345 | if (id < 0) | |
5346 | continue; | |
5347 | aof.set.ids[aof.set.cnt++] = id; | |
5348 | } | |
5349 | ||
5350 | if (!aof.set.cnt) | |
5351 | return NULL; | |
5352 | sort(&aof.set.ids, aof.set.cnt, sizeof(aof.set.ids[0]), btf_id_cmp_func, NULL); | |
5353 | ||
5354 | n = btf_nr_types(btf); | |
5355 | for (i = 1; i < n; i++) { | |
5356 | struct btf_struct_metas *new_tab; | |
5357 | const struct btf_member *member; | |
8ffa5cc1 KKD |
5358 | struct btf_struct_meta *type; |
5359 | struct btf_record *record; | |
5360 | const struct btf_type *t; | |
5361 | int j, tab_cnt; | |
5362 | ||
5363 | t = btf_type_by_id(btf, i); | |
5364 | if (!t) { | |
5365 | ret = -EINVAL; | |
5366 | goto free; | |
5367 | } | |
5368 | if (!__btf_type_is_struct(t)) | |
5369 | continue; | |
5370 | ||
5371 | cond_resched(); | |
5372 | ||
5373 | for_each_member(j, t, member) { | |
5374 | if (btf_id_set_contains(&aof.set, member->type)) | |
5375 | goto parse; | |
5376 | } | |
5377 | continue; | |
5378 | parse: | |
5379 | tab_cnt = tab ? tab->cnt : 0; | |
5380 | new_tab = krealloc(tab, offsetof(struct btf_struct_metas, types[tab_cnt + 1]), | |
5381 | GFP_KERNEL | __GFP_NOWARN); | |
5382 | if (!new_tab) { | |
5383 | ret = -ENOMEM; | |
5384 | goto free; | |
5385 | } | |
5386 | if (!tab) | |
5387 | new_tab->cnt = 0; | |
5388 | tab = new_tab; | |
5389 | ||
5390 | type = &tab->types[tab->cnt]; | |
5391 | type->btf_id = i; | |
9c395c1b | 5392 | record = btf_parse_fields(btf, t, BPF_SPIN_LOCK | BPF_LIST_HEAD | BPF_LIST_NODE | |
d54730b5 | 5393 | BPF_RB_ROOT | BPF_RB_NODE | BPF_REFCOUNT, t->size); |
8ffa5cc1 KKD |
5394 | /* The record cannot be unset, treat it as an error if so */ |
5395 | if (IS_ERR_OR_NULL(record)) { | |
5396 | ret = PTR_ERR_OR_ZERO(record) ?: -EFAULT; | |
5397 | goto free; | |
5398 | } | |
8ffa5cc1 | 5399 | type->record = record; |
8ffa5cc1 KKD |
5400 | tab->cnt++; |
5401 | } | |
5402 | return tab; | |
5403 | free: | |
5404 | btf_struct_metas_free(tab); | |
5405 | return ERR_PTR(ret); | |
5406 | } | |
5407 | ||
5408 | struct btf_struct_meta *btf_find_struct_meta(const struct btf *btf, u32 btf_id) | |
5409 | { | |
5410 | struct btf_struct_metas *tab; | |
5411 | ||
5412 | BUILD_BUG_ON(offsetof(struct btf_struct_meta, btf_id) != 0); | |
5413 | tab = btf->struct_meta_tab; | |
5414 | if (!tab) | |
5415 | return NULL; | |
5416 | return bsearch(&btf_id, tab->types, tab->cnt, sizeof(tab->types[0]), btf_id_cmp_func); | |
5417 | } | |
5418 | ||
eb596b09 KKD |
5419 | static int btf_check_type_tags(struct btf_verifier_env *env, |
5420 | struct btf *btf, int start_id) | |
5421 | { | |
5422 | int i, n, good_id = start_id - 1; | |
5423 | bool in_tags; | |
5424 | ||
5425 | n = btf_nr_types(btf); | |
5426 | for (i = start_id; i < n; i++) { | |
5427 | const struct btf_type *t; | |
d1a374a1 | 5428 | int chain_limit = 32; |
eb596b09 KKD |
5429 | u32 cur_id = i; |
5430 | ||
5431 | t = btf_type_by_id(btf, i); | |
5432 | if (!t) | |
5433 | return -EINVAL; | |
5434 | if (!btf_type_is_modifier(t)) | |
5435 | continue; | |
5436 | ||
5437 | cond_resched(); | |
5438 | ||
5439 | in_tags = btf_type_is_type_tag(t); | |
5440 | while (btf_type_is_modifier(t)) { | |
d1a374a1 KKD |
5441 | if (!chain_limit--) { |
5442 | btf_verifier_log(env, "Max chain length or cycle detected"); | |
5443 | return -ELOOP; | |
5444 | } | |
eb596b09 KKD |
5445 | if (btf_type_is_type_tag(t)) { |
5446 | if (!in_tags) { | |
5447 | btf_verifier_log(env, "Type tags don't precede modifiers"); | |
5448 | return -EINVAL; | |
5449 | } | |
5450 | } else if (in_tags) { | |
5451 | in_tags = false; | |
5452 | } | |
5453 | if (cur_id <= good_id) | |
5454 | break; | |
5455 | /* Move to next type */ | |
5456 | cur_id = t->type; | |
5457 | t = btf_type_by_id(btf, cur_id); | |
5458 | if (!t) | |
5459 | return -EINVAL; | |
5460 | } | |
5461 | good_id = i; | |
5462 | } | |
5463 | return 0; | |
5464 | } | |
5465 | ||
bdcab414 | 5466 | static int finalize_log(struct bpf_verifier_log *log, bpfptr_t uattr, u32 uattr_size) |
69b693f0 | 5467 | { |
bdcab414 AN |
5468 | u32 log_true_size; |
5469 | int err; | |
5470 | ||
5471 | err = bpf_vlog_finalize(log, &log_true_size); | |
5472 | ||
5473 | if (uattr_size >= offsetofend(union bpf_attr, btf_log_true_size) && | |
5474 | copy_to_bpfptr_offset(uattr, offsetof(union bpf_attr, btf_log_true_size), | |
5475 | &log_true_size, sizeof(log_true_size))) | |
5476 | err = -EFAULT; | |
5477 | ||
5478 | return err; | |
5479 | } | |
5480 | ||
47a71c1f | 5481 | static struct btf *btf_parse(const union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size) |
69b693f0 | 5482 | { |
47a71c1f AN |
5483 | bpfptr_t btf_data = make_bpfptr(attr->btf, uattr.is_kernel); |
5484 | char __user *log_ubuf = u64_to_user_ptr(attr->btf_log_buf); | |
8ffa5cc1 | 5485 | struct btf_struct_metas *struct_meta_tab; |
69b693f0 | 5486 | struct btf_verifier_env *env = NULL; |
69b693f0 MKL |
5487 | struct btf *btf = NULL; |
5488 | u8 *data; | |
bdcab414 | 5489 | int err, ret; |
69b693f0 | 5490 | |
47a71c1f | 5491 | if (attr->btf_size > BTF_MAX_SIZE) |
69b693f0 MKL |
5492 | return ERR_PTR(-E2BIG); |
5493 | ||
5494 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
5495 | if (!env) | |
5496 | return ERR_PTR(-ENOMEM); | |
5497 | ||
bdcab414 AN |
5498 | /* user could have requested verbose verifier output |
5499 | * and supplied buffer to store the verification trace | |
5500 | */ | |
5501 | err = bpf_vlog_init(&env->log, attr->btf_log_level, | |
5502 | log_ubuf, attr->btf_log_size); | |
5503 | if (err) | |
5504 | goto errout_free; | |
69b693f0 MKL |
5505 | |
5506 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
5507 | if (!btf) { | |
5508 | err = -ENOMEM; | |
5509 | goto errout; | |
5510 | } | |
f80442a4 MKL |
5511 | env->btf = btf; |
5512 | ||
47a71c1f | 5513 | data = kvmalloc(attr->btf_size, GFP_KERNEL | __GFP_NOWARN); |
69b693f0 MKL |
5514 | if (!data) { |
5515 | err = -ENOMEM; | |
5516 | goto errout; | |
5517 | } | |
5518 | ||
5519 | btf->data = data; | |
47a71c1f | 5520 | btf->data_size = attr->btf_size; |
69b693f0 | 5521 | |
47a71c1f | 5522 | if (copy_from_bpfptr(data, btf_data, attr->btf_size)) { |
69b693f0 MKL |
5523 | err = -EFAULT; |
5524 | goto errout; | |
5525 | } | |
5526 | ||
4a6998af ML |
5527 | err = btf_parse_hdr(env); |
5528 | if (err) | |
5529 | goto errout; | |
5530 | ||
5531 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
5532 | ||
69b693f0 MKL |
5533 | err = btf_parse_str_sec(env); |
5534 | if (err) | |
5535 | goto errout; | |
5536 | ||
5537 | err = btf_parse_type_sec(env); | |
5538 | if (err) | |
5539 | goto errout; | |
5540 | ||
eb596b09 KKD |
5541 | err = btf_check_type_tags(env, btf, 1); |
5542 | if (err) | |
5543 | goto errout; | |
5544 | ||
bdcab414 | 5545 | struct_meta_tab = btf_parse_struct_metas(&env->log, btf); |
8ffa5cc1 KKD |
5546 | if (IS_ERR(struct_meta_tab)) { |
5547 | err = PTR_ERR(struct_meta_tab); | |
5548 | goto errout; | |
5549 | } | |
5550 | btf->struct_meta_tab = struct_meta_tab; | |
5551 | ||
865ce09a KKD |
5552 | if (struct_meta_tab) { |
5553 | int i; | |
5554 | ||
5555 | for (i = 0; i < struct_meta_tab->cnt; i++) { | |
5556 | err = btf_check_and_fixup_fields(btf, struct_meta_tab->types[i].record); | |
5557 | if (err < 0) | |
5558 | goto errout_meta; | |
5559 | } | |
5560 | } | |
5561 | ||
bdcab414 AN |
5562 | err = finalize_log(&env->log, uattr, uattr_size); |
5563 | if (err) | |
5564 | goto errout_free; | |
69b693f0 | 5565 | |
f80442a4 MKL |
5566 | btf_verifier_env_free(env); |
5567 | refcount_set(&btf->refcnt, 1); | |
5568 | return btf; | |
69b693f0 | 5569 | |
8ffa5cc1 KKD |
5570 | errout_meta: |
5571 | btf_free_struct_meta_tab(btf); | |
69b693f0 | 5572 | errout: |
bdcab414 AN |
5573 | /* overwrite err with -ENOSPC or -EFAULT */ |
5574 | ret = finalize_log(&env->log, uattr, uattr_size); | |
5575 | if (ret) | |
5576 | err = ret; | |
5577 | errout_free: | |
69b693f0 MKL |
5578 | btf_verifier_env_free(env); |
5579 | if (btf) | |
5580 | btf_free(btf); | |
5581 | return ERR_PTR(err); | |
5582 | } | |
b00b8dae | 5583 | |
90ceddcb FS |
5584 | extern char __weak __start_BTF[]; |
5585 | extern char __weak __stop_BTF[]; | |
91cc1a99 AS |
5586 | extern struct btf *btf_vmlinux; |
5587 | ||
5588 | #define BPF_MAP_TYPE(_id, _ops) | |
f2e10bff | 5589 | #define BPF_LINK_TYPE(_id, _name) |
91cc1a99 AS |
5590 | static union { |
5591 | struct bpf_ctx_convert { | |
5592 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
5593 | prog_ctx_type _id##_prog; \ | |
5594 | kern_ctx_type _id##_kern; | |
5595 | #include <linux/bpf_types.h> | |
5596 | #undef BPF_PROG_TYPE | |
5597 | } *__t; | |
5598 | /* 't' is written once under lock. Read many times. */ | |
5599 | const struct btf_type *t; | |
5600 | } bpf_ctx_convert; | |
5601 | enum { | |
5602 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
5603 | __ctx_convert##_id, | |
5604 | #include <linux/bpf_types.h> | |
5605 | #undef BPF_PROG_TYPE | |
ce27709b | 5606 | __ctx_convert_unused, /* to avoid empty enum in extreme .config */ |
91cc1a99 AS |
5607 | }; |
5608 | static u8 bpf_ctx_convert_map[] = { | |
5609 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
5610 | [_id] = __ctx_convert##_id, | |
5611 | #include <linux/bpf_types.h> | |
5612 | #undef BPF_PROG_TYPE | |
4c80c7bc | 5613 | 0, /* avoid empty array */ |
91cc1a99 AS |
5614 | }; |
5615 | #undef BPF_MAP_TYPE | |
f2e10bff | 5616 | #undef BPF_LINK_TYPE |
91cc1a99 | 5617 | |
66967a32 | 5618 | static const struct btf_type *find_canonical_prog_ctx_type(enum bpf_prog_type prog_type) |
91cc1a99 AS |
5619 | { |
5620 | const struct btf_type *conv_struct; | |
91cc1a99 | 5621 | const struct btf_member *ctx_type; |
91cc1a99 AS |
5622 | |
5623 | conv_struct = bpf_ctx_convert.t; | |
66967a32 | 5624 | if (!conv_struct) |
91cc1a99 | 5625 | return NULL; |
66967a32 AN |
5626 | /* prog_type is valid bpf program type. No need for bounds check. */ |
5627 | ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2; | |
5628 | /* ctx_type is a pointer to prog_ctx_type in vmlinux. | |
5629 | * Like 'struct __sk_buff' | |
5630 | */ | |
5631 | return btf_type_by_id(btf_vmlinux, ctx_type->type); | |
5632 | } | |
5633 | ||
5634 | static int find_kern_ctx_type_id(enum bpf_prog_type prog_type) | |
5635 | { | |
5636 | const struct btf_type *conv_struct; | |
5637 | const struct btf_member *ctx_type; | |
5638 | ||
5639 | conv_struct = bpf_ctx_convert.t; | |
5640 | if (!conv_struct) | |
5641 | return -EFAULT; | |
5642 | /* prog_type is valid bpf program type. No need for bounds check. */ | |
5643 | ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2 + 1; | |
5644 | /* ctx_type is a pointer to prog_ctx_type in vmlinux. | |
5645 | * Like 'struct sk_buff' | |
5646 | */ | |
5647 | return ctx_type->type; | |
5648 | } | |
5649 | ||
5650 | const struct btf_type * | |
5651 | btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf, | |
5652 | const struct btf_type *t, enum bpf_prog_type prog_type, | |
5653 | int arg) | |
5654 | { | |
5655 | const struct btf_type *ctx_type; | |
5656 | const char *tname, *ctx_tname; | |
5657 | ||
91cc1a99 AS |
5658 | t = btf_type_by_id(btf, t->type); |
5659 | while (btf_type_is_modifier(t)) | |
5660 | t = btf_type_by_id(btf, t->type); | |
5661 | if (!btf_type_is_struct(t)) { | |
5662 | /* Only pointer to struct is supported for now. | |
5663 | * That means that BPF_PROG_TYPE_TRACEPOINT with BTF | |
5664 | * is not supported yet. | |
5665 | * BPF_PROG_TYPE_RAW_TRACEPOINT is fine. | |
5666 | */ | |
91cc1a99 AS |
5667 | return NULL; |
5668 | } | |
5669 | tname = btf_name_by_offset(btf, t->name_off); | |
5670 | if (!tname) { | |
51c39bb1 | 5671 | bpf_log(log, "arg#%d struct doesn't have a name\n", arg); |
91cc1a99 AS |
5672 | return NULL; |
5673 | } | |
66967a32 AN |
5674 | |
5675 | ctx_type = find_canonical_prog_ctx_type(prog_type); | |
5676 | if (!ctx_type) { | |
5677 | bpf_log(log, "btf_vmlinux is malformed\n"); | |
91cc1a99 AS |
5678 | /* should not happen */ |
5679 | return NULL; | |
66967a32 | 5680 | } |
d384dce2 | 5681 | again: |
66967a32 | 5682 | ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_type->name_off); |
91cc1a99 AS |
5683 | if (!ctx_tname) { |
5684 | /* should not happen */ | |
5685 | bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n"); | |
5686 | return NULL; | |
5687 | } | |
5688 | /* only compare that prog's ctx type name is the same as | |
5689 | * kernel expects. No need to compare field by field. | |
5690 | * It's ok for bpf prog to do: | |
5691 | * struct __sk_buff {}; | |
5692 | * int socket_filter_bpf_prog(struct __sk_buff *skb) | |
5693 | * { // no fields of skb are ever used } | |
5694 | */ | |
2f464393 JK |
5695 | if (strcmp(ctx_tname, "__sk_buff") == 0 && strcmp(tname, "sk_buff") == 0) |
5696 | return ctx_type; | |
5697 | if (strcmp(ctx_tname, "xdp_md") == 0 && strcmp(tname, "xdp_buff") == 0) | |
5698 | return ctx_type; | |
d384dce2 AN |
5699 | if (strcmp(ctx_tname, tname)) { |
5700 | /* bpf_user_pt_regs_t is a typedef, so resolve it to | |
5701 | * underlying struct and check name again | |
5702 | */ | |
66967a32 | 5703 | if (!btf_type_is_modifier(ctx_type)) |
d384dce2 | 5704 | return NULL; |
66967a32 AN |
5705 | while (btf_type_is_modifier(ctx_type)) |
5706 | ctx_type = btf_type_by_id(btf_vmlinux, ctx_type->type); | |
d384dce2 AN |
5707 | goto again; |
5708 | } | |
91cc1a99 AS |
5709 | return ctx_type; |
5710 | } | |
8580ac94 | 5711 | |
0ba97151 AN |
5712 | /* forward declarations for arch-specific underlying types of |
5713 | * bpf_user_pt_regs_t; this avoids the need for arch-specific #ifdef | |
5714 | * compilation guards below for BPF_PROG_TYPE_PERF_EVENT checks, but still | |
5715 | * works correctly with __builtin_types_compatible_p() on respective | |
5716 | * architectures | |
5717 | */ | |
5718 | struct user_regs_struct; | |
5719 | struct user_pt_regs; | |
5720 | ||
5721 | static int btf_validate_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf, | |
5722 | const struct btf_type *t, int arg, | |
5723 | enum bpf_prog_type prog_type, | |
5724 | enum bpf_attach_type attach_type) | |
5725 | { | |
5726 | const struct btf_type *ctx_type; | |
5727 | const char *tname, *ctx_tname; | |
5728 | ||
5729 | if (!btf_is_ptr(t)) { | |
5730 | bpf_log(log, "arg#%d type isn't a pointer\n", arg); | |
5731 | return -EINVAL; | |
5732 | } | |
5733 | t = btf_type_by_id(btf, t->type); | |
5734 | ||
5735 | /* KPROBE and PERF_EVENT programs allow bpf_user_pt_regs_t typedef */ | |
5736 | if (prog_type == BPF_PROG_TYPE_KPROBE || prog_type == BPF_PROG_TYPE_PERF_EVENT) { | |
5737 | while (btf_type_is_modifier(t) && !btf_type_is_typedef(t)) | |
5738 | t = btf_type_by_id(btf, t->type); | |
5739 | ||
5740 | if (btf_type_is_typedef(t)) { | |
5741 | tname = btf_name_by_offset(btf, t->name_off); | |
5742 | if (tname && strcmp(tname, "bpf_user_pt_regs_t") == 0) | |
5743 | return 0; | |
5744 | } | |
5745 | } | |
5746 | ||
5747 | /* all other program types don't use typedefs for context type */ | |
5748 | while (btf_type_is_modifier(t)) | |
5749 | t = btf_type_by_id(btf, t->type); | |
5750 | ||
5751 | /* `void *ctx __arg_ctx` is always valid */ | |
5752 | if (btf_type_is_void(t)) | |
5753 | return 0; | |
5754 | ||
5755 | tname = btf_name_by_offset(btf, t->name_off); | |
5756 | if (str_is_empty(tname)) { | |
5757 | bpf_log(log, "arg#%d type doesn't have a name\n", arg); | |
5758 | return -EINVAL; | |
5759 | } | |
5760 | ||
5761 | /* special cases */ | |
5762 | switch (prog_type) { | |
5763 | case BPF_PROG_TYPE_KPROBE: | |
5764 | if (__btf_type_is_struct(t) && strcmp(tname, "pt_regs") == 0) | |
5765 | return 0; | |
5766 | break; | |
5767 | case BPF_PROG_TYPE_PERF_EVENT: | |
5768 | if (__builtin_types_compatible_p(bpf_user_pt_regs_t, struct pt_regs) && | |
5769 | __btf_type_is_struct(t) && strcmp(tname, "pt_regs") == 0) | |
5770 | return 0; | |
5771 | if (__builtin_types_compatible_p(bpf_user_pt_regs_t, struct user_pt_regs) && | |
5772 | __btf_type_is_struct(t) && strcmp(tname, "user_pt_regs") == 0) | |
5773 | return 0; | |
5774 | if (__builtin_types_compatible_p(bpf_user_pt_regs_t, struct user_regs_struct) && | |
5775 | __btf_type_is_struct(t) && strcmp(tname, "user_regs_struct") == 0) | |
5776 | return 0; | |
5777 | break; | |
5778 | case BPF_PROG_TYPE_RAW_TRACEPOINT: | |
5779 | case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: | |
5780 | /* allow u64* as ctx */ | |
5781 | if (btf_is_int(t) && t->size == 8) | |
5782 | return 0; | |
5783 | break; | |
5784 | case BPF_PROG_TYPE_TRACING: | |
5785 | switch (attach_type) { | |
5786 | case BPF_TRACE_RAW_TP: | |
5787 | /* tp_btf program is TRACING, so need special case here */ | |
5788 | if (__btf_type_is_struct(t) && | |
5789 | strcmp(tname, "bpf_raw_tracepoint_args") == 0) | |
5790 | return 0; | |
5791 | /* allow u64* as ctx */ | |
5792 | if (btf_is_int(t) && t->size == 8) | |
5793 | return 0; | |
5794 | break; | |
5795 | case BPF_TRACE_ITER: | |
5796 | /* allow struct bpf_iter__xxx types only */ | |
5797 | if (__btf_type_is_struct(t) && | |
5798 | strncmp(tname, "bpf_iter__", sizeof("bpf_iter__") - 1) == 0) | |
5799 | return 0; | |
5800 | break; | |
5801 | case BPF_TRACE_FENTRY: | |
5802 | case BPF_TRACE_FEXIT: | |
5803 | case BPF_MODIFY_RETURN: | |
5804 | /* allow u64* as ctx */ | |
5805 | if (btf_is_int(t) && t->size == 8) | |
5806 | return 0; | |
5807 | break; | |
5808 | default: | |
5809 | break; | |
5810 | } | |
5811 | break; | |
5812 | case BPF_PROG_TYPE_LSM: | |
5813 | case BPF_PROG_TYPE_STRUCT_OPS: | |
5814 | /* allow u64* as ctx */ | |
5815 | if (btf_is_int(t) && t->size == 8) | |
5816 | return 0; | |
5817 | break; | |
5818 | case BPF_PROG_TYPE_TRACEPOINT: | |
5819 | case BPF_PROG_TYPE_SYSCALL: | |
5820 | case BPF_PROG_TYPE_EXT: | |
5821 | return 0; /* anything goes */ | |
5822 | default: | |
5823 | break; | |
5824 | } | |
5825 | ||
5826 | ctx_type = find_canonical_prog_ctx_type(prog_type); | |
5827 | if (!ctx_type) { | |
5828 | /* should not happen */ | |
5829 | bpf_log(log, "btf_vmlinux is malformed\n"); | |
5830 | return -EINVAL; | |
5831 | } | |
5832 | ||
5833 | /* resolve typedefs and check that underlying structs are matching as well */ | |
5834 | while (btf_type_is_modifier(ctx_type)) | |
5835 | ctx_type = btf_type_by_id(btf_vmlinux, ctx_type->type); | |
5836 | ||
5837 | /* if program type doesn't have distinctly named struct type for | |
5838 | * context, then __arg_ctx argument can only be `void *`, which we | |
5839 | * already checked above | |
5840 | */ | |
5841 | if (!__btf_type_is_struct(ctx_type)) { | |
5842 | bpf_log(log, "arg#%d should be void pointer\n", arg); | |
5843 | return -EINVAL; | |
5844 | } | |
5845 | ||
5846 | ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_type->name_off); | |
5847 | if (!__btf_type_is_struct(t) || strcmp(ctx_tname, tname) != 0) { | |
5848 | bpf_log(log, "arg#%d should be `struct %s *`\n", arg, ctx_tname); | |
5849 | return -EINVAL; | |
5850 | } | |
5851 | ||
5852 | return 0; | |
5853 | } | |
5854 | ||
5b92a28a AS |
5855 | static int btf_translate_to_vmlinux(struct bpf_verifier_log *log, |
5856 | struct btf *btf, | |
5857 | const struct btf_type *t, | |
51c39bb1 AS |
5858 | enum bpf_prog_type prog_type, |
5859 | int arg) | |
5b92a28a | 5860 | { |
66967a32 | 5861 | if (!btf_get_prog_ctx_type(log, btf, t, prog_type, arg)) |
5b92a28a | 5862 | return -ENOENT; |
66967a32 | 5863 | return find_kern_ctx_type_id(prog_type); |
5b92a28a AS |
5864 | } |
5865 | ||
fd264ca0 YS |
5866 | int get_kern_ctx_btf_id(struct bpf_verifier_log *log, enum bpf_prog_type prog_type) |
5867 | { | |
5868 | const struct btf_member *kctx_member; | |
5869 | const struct btf_type *conv_struct; | |
5870 | const struct btf_type *kctx_type; | |
5871 | u32 kctx_type_id; | |
5872 | ||
5873 | conv_struct = bpf_ctx_convert.t; | |
5874 | /* get member for kernel ctx type */ | |
5875 | kctx_member = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2 + 1; | |
5876 | kctx_type_id = kctx_member->type; | |
5877 | kctx_type = btf_type_by_id(btf_vmlinux, kctx_type_id); | |
5878 | if (!btf_type_is_struct(kctx_type)) { | |
5879 | bpf_log(log, "kern ctx type id %u is not a struct\n", kctx_type_id); | |
5880 | return -EINVAL; | |
5881 | } | |
5882 | ||
5883 | return kctx_type_id; | |
5884 | } | |
5885 | ||
49f4e672 JO |
5886 | BTF_ID_LIST(bpf_ctx_convert_btf_id) |
5887 | BTF_ID(struct, bpf_ctx_convert) | |
5888 | ||
8580ac94 AS |
5889 | struct btf *btf_parse_vmlinux(void) |
5890 | { | |
5891 | struct btf_verifier_env *env = NULL; | |
5892 | struct bpf_verifier_log *log; | |
5893 | struct btf *btf = NULL; | |
49f4e672 | 5894 | int err; |
8580ac94 AS |
5895 | |
5896 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
5897 | if (!env) | |
5898 | return ERR_PTR(-ENOMEM); | |
5899 | ||
5900 | log = &env->log; | |
5901 | log->level = BPF_LOG_KERNEL; | |
5902 | ||
5903 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
5904 | if (!btf) { | |
5905 | err = -ENOMEM; | |
5906 | goto errout; | |
5907 | } | |
5908 | env->btf = btf; | |
5909 | ||
90ceddcb FS |
5910 | btf->data = __start_BTF; |
5911 | btf->data_size = __stop_BTF - __start_BTF; | |
53297220 AN |
5912 | btf->kernel_btf = true; |
5913 | snprintf(btf->name, sizeof(btf->name), "vmlinux"); | |
8580ac94 AS |
5914 | |
5915 | err = btf_parse_hdr(env); | |
5916 | if (err) | |
5917 | goto errout; | |
5918 | ||
5919 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
5920 | ||
5921 | err = btf_parse_str_sec(env); | |
5922 | if (err) | |
5923 | goto errout; | |
5924 | ||
5925 | err = btf_check_all_metas(env); | |
5926 | if (err) | |
5927 | goto errout; | |
5928 | ||
eb596b09 KKD |
5929 | err = btf_check_type_tags(env, btf, 1); |
5930 | if (err) | |
5931 | goto errout; | |
5932 | ||
a2d0d62f | 5933 | /* btf_parse_vmlinux() runs under bpf_verifier_lock */ |
49f4e672 | 5934 | bpf_ctx_convert.t = btf_type_by_id(btf, bpf_ctx_convert_btf_id[0]); |
91cc1a99 | 5935 | |
d3e42bb0 | 5936 | bpf_struct_ops_init(btf, log); |
27ae7997 | 5937 | |
8580ac94 | 5938 | refcount_set(&btf->refcnt, 1); |
53297220 AN |
5939 | |
5940 | err = btf_alloc_id(btf); | |
5941 | if (err) | |
5942 | goto errout; | |
5943 | ||
5944 | btf_verifier_env_free(env); | |
8580ac94 AS |
5945 | return btf; |
5946 | ||
5947 | errout: | |
5948 | btf_verifier_env_free(env); | |
5949 | if (btf) { | |
5950 | kvfree(btf->types); | |
5951 | kfree(btf); | |
5952 | } | |
5953 | return ERR_PTR(err); | |
5954 | } | |
5955 | ||
7112d127 AN |
5956 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
5957 | ||
36e68442 AN |
5958 | static struct btf *btf_parse_module(const char *module_name, const void *data, unsigned int data_size) |
5959 | { | |
5960 | struct btf_verifier_env *env = NULL; | |
5961 | struct bpf_verifier_log *log; | |
5962 | struct btf *btf = NULL, *base_btf; | |
5963 | int err; | |
5964 | ||
5965 | base_btf = bpf_get_btf_vmlinux(); | |
5966 | if (IS_ERR(base_btf)) | |
5967 | return base_btf; | |
5968 | if (!base_btf) | |
5969 | return ERR_PTR(-EINVAL); | |
5970 | ||
5971 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
5972 | if (!env) | |
5973 | return ERR_PTR(-ENOMEM); | |
5974 | ||
5975 | log = &env->log; | |
5976 | log->level = BPF_LOG_KERNEL; | |
5977 | ||
5978 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
5979 | if (!btf) { | |
5980 | err = -ENOMEM; | |
5981 | goto errout; | |
5982 | } | |
5983 | env->btf = btf; | |
5984 | ||
5985 | btf->base_btf = base_btf; | |
5986 | btf->start_id = base_btf->nr_types; | |
5987 | btf->start_str_off = base_btf->hdr.str_len; | |
5988 | btf->kernel_btf = true; | |
5989 | snprintf(btf->name, sizeof(btf->name), "%s", module_name); | |
5990 | ||
5991 | btf->data = kvmalloc(data_size, GFP_KERNEL | __GFP_NOWARN); | |
5992 | if (!btf->data) { | |
5993 | err = -ENOMEM; | |
5994 | goto errout; | |
5995 | } | |
5996 | memcpy(btf->data, data, data_size); | |
5997 | btf->data_size = data_size; | |
5998 | ||
5999 | err = btf_parse_hdr(env); | |
6000 | if (err) | |
6001 | goto errout; | |
6002 | ||
6003 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
6004 | ||
6005 | err = btf_parse_str_sec(env); | |
6006 | if (err) | |
6007 | goto errout; | |
6008 | ||
6009 | err = btf_check_all_metas(env); | |
6010 | if (err) | |
6011 | goto errout; | |
6012 | ||
eb596b09 KKD |
6013 | err = btf_check_type_tags(env, btf, btf_nr_types(base_btf)); |
6014 | if (err) | |
6015 | goto errout; | |
6016 | ||
36e68442 AN |
6017 | btf_verifier_env_free(env); |
6018 | refcount_set(&btf->refcnt, 1); | |
6019 | return btf; | |
6020 | ||
6021 | errout: | |
6022 | btf_verifier_env_free(env); | |
6023 | if (btf) { | |
6024 | kvfree(btf->data); | |
6025 | kvfree(btf->types); | |
6026 | kfree(btf); | |
6027 | } | |
6028 | return ERR_PTR(err); | |
6029 | } | |
6030 | ||
7112d127 AN |
6031 | #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */ |
6032 | ||
5b92a28a AS |
6033 | struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog) |
6034 | { | |
3aac1ead | 6035 | struct bpf_prog *tgt_prog = prog->aux->dst_prog; |
5b92a28a | 6036 | |
22dc4a0f | 6037 | if (tgt_prog) |
5b92a28a | 6038 | return tgt_prog->aux->btf; |
22dc4a0f AN |
6039 | else |
6040 | return prog->aux->attach_btf; | |
5b92a28a AS |
6041 | } |
6042 | ||
bb6728d7 | 6043 | static bool is_int_ptr(struct btf *btf, const struct btf_type *t) |
84ad7a7a | 6044 | { |
91f2dc68 FZ |
6045 | /* skip modifiers */ |
6046 | t = btf_type_skip_modifiers(btf, t->type, NULL); | |
84ad7a7a | 6047 | |
bb6728d7 | 6048 | return btf_type_is_int(t); |
84ad7a7a JO |
6049 | } |
6050 | ||
720e6a43 YS |
6051 | static u32 get_ctx_arg_idx(struct btf *btf, const struct btf_type *func_proto, |
6052 | int off) | |
6053 | { | |
6054 | const struct btf_param *args; | |
6055 | const struct btf_type *t; | |
6056 | u32 offset = 0, nr_args; | |
6057 | int i; | |
6058 | ||
6059 | if (!func_proto) | |
6060 | return off / 8; | |
6061 | ||
6062 | nr_args = btf_type_vlen(func_proto); | |
6063 | args = (const struct btf_param *)(func_proto + 1); | |
6064 | for (i = 0; i < nr_args; i++) { | |
6065 | t = btf_type_skip_modifiers(btf, args[i].type, NULL); | |
6066 | offset += btf_type_is_ptr(t) ? 8 : roundup(t->size, 8); | |
6067 | if (off < offset) | |
6068 | return i; | |
6069 | } | |
6070 | ||
6071 | t = btf_type_skip_modifiers(btf, func_proto->type, NULL); | |
6072 | offset += btf_type_is_ptr(t) ? 8 : roundup(t->size, 8); | |
6073 | if (off < offset) | |
6074 | return nr_args; | |
6075 | ||
6076 | return nr_args + 1; | |
6077 | } | |
6078 | ||
c6b0337f | 6079 | static bool prog_args_trusted(const struct bpf_prog *prog) |
3f00c523 | 6080 | { |
c6b0337f AS |
6081 | enum bpf_attach_type atype = prog->expected_attach_type; |
6082 | ||
6083 | switch (prog->type) { | |
6084 | case BPF_PROG_TYPE_TRACING: | |
6085 | return atype == BPF_TRACE_RAW_TP || atype == BPF_TRACE_ITER; | |
6086 | case BPF_PROG_TYPE_LSM: | |
c0c852dd | 6087 | return bpf_lsm_is_trusted(prog); |
c6b0337f AS |
6088 | case BPF_PROG_TYPE_STRUCT_OPS: |
6089 | return true; | |
6090 | default: | |
6091 | return false; | |
6092 | } | |
3f00c523 DV |
6093 | } |
6094 | ||
9e15db66 AS |
6095 | bool btf_ctx_access(int off, int size, enum bpf_access_type type, |
6096 | const struct bpf_prog *prog, | |
6097 | struct bpf_insn_access_aux *info) | |
6098 | { | |
38207291 | 6099 | const struct btf_type *t = prog->aux->attach_func_proto; |
3aac1ead | 6100 | struct bpf_prog *tgt_prog = prog->aux->dst_prog; |
5b92a28a | 6101 | struct btf *btf = bpf_prog_get_target_btf(prog); |
38207291 | 6102 | const char *tname = prog->aux->attach_func_name; |
9e15db66 | 6103 | struct bpf_verifier_log *log = info->log; |
9e15db66 | 6104 | const struct btf_param *args; |
c6f1bfe8 | 6105 | const char *tag_value; |
9e15db66 | 6106 | u32 nr_args, arg; |
3c32cc1b | 6107 | int i, ret; |
9e15db66 | 6108 | |
9e15db66 | 6109 | if (off % 8) { |
38207291 | 6110 | bpf_log(log, "func '%s' offset %d is not multiple of 8\n", |
9e15db66 AS |
6111 | tname, off); |
6112 | return false; | |
6113 | } | |
720e6a43 | 6114 | arg = get_ctx_arg_idx(btf, t, off); |
9e15db66 | 6115 | args = (const struct btf_param *)(t + 1); |
523a4cf4 DB |
6116 | /* if (t == NULL) Fall back to default BPF prog with |
6117 | * MAX_BPF_FUNC_REG_ARGS u64 arguments. | |
6118 | */ | |
6119 | nr_args = t ? btf_type_vlen(t) : MAX_BPF_FUNC_REG_ARGS; | |
38207291 MKL |
6120 | if (prog->aux->attach_btf_trace) { |
6121 | /* skip first 'void *__data' argument in btf_trace_##name typedef */ | |
6122 | args++; | |
6123 | nr_args--; | |
6124 | } | |
fec56f58 | 6125 | |
f50b49a0 KS |
6126 | if (arg > nr_args) { |
6127 | bpf_log(log, "func '%s' doesn't have %d-th argument\n", | |
6128 | tname, arg + 1); | |
6129 | return false; | |
6130 | } | |
6131 | ||
6ba43b76 | 6132 | if (arg == nr_args) { |
f50b49a0 | 6133 | switch (prog->expected_attach_type) { |
69fd337a | 6134 | case BPF_LSM_CGROUP: |
f50b49a0 KS |
6135 | case BPF_LSM_MAC: |
6136 | case BPF_TRACE_FEXIT: | |
9e4e01df KS |
6137 | /* When LSM programs are attached to void LSM hooks |
6138 | * they use FEXIT trampolines and when attached to | |
6139 | * int LSM hooks, they use MODIFY_RETURN trampolines. | |
6140 | * | |
6141 | * While the LSM programs are BPF_MODIFY_RETURN-like | |
6142 | * the check: | |
6143 | * | |
6144 | * if (ret_type != 'int') | |
6145 | * return -EINVAL; | |
6146 | * | |
6147 | * is _not_ done here. This is still safe as LSM hooks | |
6148 | * have only void and int return types. | |
6149 | */ | |
6ba43b76 KS |
6150 | if (!t) |
6151 | return true; | |
6152 | t = btf_type_by_id(btf, t->type); | |
f50b49a0 KS |
6153 | break; |
6154 | case BPF_MODIFY_RETURN: | |
6ba43b76 KS |
6155 | /* For now the BPF_MODIFY_RETURN can only be attached to |
6156 | * functions that return an int. | |
6157 | */ | |
6158 | if (!t) | |
6159 | return false; | |
6160 | ||
6161 | t = btf_type_skip_modifiers(btf, t->type, NULL); | |
a9b59159 | 6162 | if (!btf_type_is_small_int(t)) { |
6ba43b76 KS |
6163 | bpf_log(log, |
6164 | "ret type %s not allowed for fmod_ret\n", | |
571f9738 | 6165 | btf_type_str(t)); |
6ba43b76 KS |
6166 | return false; |
6167 | } | |
f50b49a0 KS |
6168 | break; |
6169 | default: | |
6170 | bpf_log(log, "func '%s' doesn't have %d-th argument\n", | |
6171 | tname, arg + 1); | |
6172 | return false; | |
6ba43b76 | 6173 | } |
fec56f58 | 6174 | } else { |
5b92a28a | 6175 | if (!t) |
523a4cf4 | 6176 | /* Default prog with MAX_BPF_FUNC_REG_ARGS args */ |
5b92a28a AS |
6177 | return true; |
6178 | t = btf_type_by_id(btf, args[arg].type); | |
9e15db66 | 6179 | } |
f50b49a0 | 6180 | |
9e15db66 AS |
6181 | /* skip modifiers */ |
6182 | while (btf_type_is_modifier(t)) | |
5b92a28a | 6183 | t = btf_type_by_id(btf, t->type); |
720e6a43 | 6184 | if (btf_type_is_small_int(t) || btf_is_any_enum(t) || __btf_type_is_struct(t)) |
9e15db66 AS |
6185 | /* accessing a scalar */ |
6186 | return true; | |
6187 | if (!btf_type_is_ptr(t)) { | |
6188 | bpf_log(log, | |
38207291 | 6189 | "func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n", |
9e15db66 | 6190 | tname, arg, |
5b92a28a | 6191 | __btf_name_by_offset(btf, t->name_off), |
571f9738 | 6192 | btf_type_str(t)); |
9e15db66 AS |
6193 | return false; |
6194 | } | |
afbf21dc YS |
6195 | |
6196 | /* check for PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL */ | |
6197 | for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { | |
6198 | const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; | |
c25b2ae1 | 6199 | u32 type, flag; |
afbf21dc | 6200 | |
c25b2ae1 HL |
6201 | type = base_type(ctx_arg_info->reg_type); |
6202 | flag = type_flag(ctx_arg_info->reg_type); | |
20b2aff4 | 6203 | if (ctx_arg_info->offset == off && type == PTR_TO_BUF && |
c25b2ae1 | 6204 | (flag & PTR_MAYBE_NULL)) { |
afbf21dc YS |
6205 | info->reg_type = ctx_arg_info->reg_type; |
6206 | return true; | |
6207 | } | |
6208 | } | |
6209 | ||
9e15db66 AS |
6210 | if (t->type == 0) |
6211 | /* This is a pointer to void. | |
6212 | * It is the same as scalar from the verifier safety pov. | |
6213 | * No further pointer walking is allowed. | |
6214 | */ | |
6215 | return true; | |
6216 | ||
bb6728d7 | 6217 | if (is_int_ptr(btf, t)) |
84ad7a7a JO |
6218 | return true; |
6219 | ||
9e15db66 | 6220 | /* this is a pointer to another type */ |
3c32cc1b YS |
6221 | for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { |
6222 | const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; | |
6223 | ||
6224 | if (ctx_arg_info->offset == off) { | |
d3621642 YS |
6225 | if (!ctx_arg_info->btf_id) { |
6226 | bpf_log(log,"invalid btf_id for context argument offset %u\n", off); | |
6227 | return false; | |
6228 | } | |
6229 | ||
3c32cc1b | 6230 | info->reg_type = ctx_arg_info->reg_type; |
22dc4a0f | 6231 | info->btf = btf_vmlinux; |
951cf368 YS |
6232 | info->btf_id = ctx_arg_info->btf_id; |
6233 | return true; | |
3c32cc1b YS |
6234 | } |
6235 | } | |
9e15db66 | 6236 | |
951cf368 | 6237 | info->reg_type = PTR_TO_BTF_ID; |
c6b0337f | 6238 | if (prog_args_trusted(prog)) |
3f00c523 DV |
6239 | info->reg_type |= PTR_TRUSTED; |
6240 | ||
5b92a28a | 6241 | if (tgt_prog) { |
43bc2874 THJ |
6242 | enum bpf_prog_type tgt_type; |
6243 | ||
6244 | if (tgt_prog->type == BPF_PROG_TYPE_EXT) | |
6245 | tgt_type = tgt_prog->aux->saved_dst_prog_type; | |
6246 | else | |
6247 | tgt_type = tgt_prog->type; | |
6248 | ||
6249 | ret = btf_translate_to_vmlinux(log, btf, t, tgt_type, arg); | |
5b92a28a | 6250 | if (ret > 0) { |
22dc4a0f | 6251 | info->btf = btf_vmlinux; |
5b92a28a AS |
6252 | info->btf_id = ret; |
6253 | return true; | |
6254 | } else { | |
6255 | return false; | |
6256 | } | |
6257 | } | |
275517ff | 6258 | |
22dc4a0f | 6259 | info->btf = btf; |
275517ff | 6260 | info->btf_id = t->type; |
5b92a28a | 6261 | t = btf_type_by_id(btf, t->type); |
c6f1bfe8 YS |
6262 | |
6263 | if (btf_type_is_type_tag(t)) { | |
6264 | tag_value = __btf_name_by_offset(btf, t->name_off); | |
6265 | if (strcmp(tag_value, "user") == 0) | |
6266 | info->reg_type |= MEM_USER; | |
5844101a HL |
6267 | if (strcmp(tag_value, "percpu") == 0) |
6268 | info->reg_type |= MEM_PERCPU; | |
c6f1bfe8 YS |
6269 | } |
6270 | ||
9e15db66 | 6271 | /* skip modifiers */ |
275517ff MKL |
6272 | while (btf_type_is_modifier(t)) { |
6273 | info->btf_id = t->type; | |
5b92a28a | 6274 | t = btf_type_by_id(btf, t->type); |
275517ff | 6275 | } |
9e15db66 AS |
6276 | if (!btf_type_is_struct(t)) { |
6277 | bpf_log(log, | |
38207291 | 6278 | "func '%s' arg%d type %s is not a struct\n", |
571f9738 | 6279 | tname, arg, btf_type_str(t)); |
9e15db66 AS |
6280 | return false; |
6281 | } | |
38207291 | 6282 | bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n", |
571f9738 | 6283 | tname, arg, info->btf_id, btf_type_str(t), |
5b92a28a | 6284 | __btf_name_by_offset(btf, t->name_off)); |
9e15db66 AS |
6285 | return true; |
6286 | } | |
6287 | ||
1c6d28a6 JO |
6288 | enum bpf_struct_walk_result { |
6289 | /* < 0 error */ | |
6290 | WALK_SCALAR = 0, | |
6291 | WALK_PTR, | |
6292 | WALK_STRUCT, | |
6293 | }; | |
6294 | ||
22dc4a0f | 6295 | static int btf_struct_walk(struct bpf_verifier_log *log, const struct btf *btf, |
1c6d28a6 | 6296 | const struct btf_type *t, int off, int size, |
63260df1 AS |
6297 | u32 *next_btf_id, enum bpf_type_flag *flag, |
6298 | const char **field_name) | |
9e15db66 | 6299 | { |
7e3617a7 MKL |
6300 | u32 i, moff, mtrue_end, msize = 0, total_nelems = 0; |
6301 | const struct btf_type *mtype, *elem_type = NULL; | |
9e15db66 | 6302 | const struct btf_member *member; |
c6f1bfe8 | 6303 | const char *tname, *mname, *tag_value; |
1c6d28a6 | 6304 | u32 vlen, elem_id, mid; |
9e15db66 AS |
6305 | |
6306 | again: | |
819d4342 SF |
6307 | if (btf_type_is_modifier(t)) |
6308 | t = btf_type_skip_modifiers(btf, t->type, NULL); | |
22dc4a0f | 6309 | tname = __btf_name_by_offset(btf, t->name_off); |
9e15db66 | 6310 | if (!btf_type_is_struct(t)) { |
275517ff | 6311 | bpf_log(log, "Type '%s' is not a struct\n", tname); |
9e15db66 AS |
6312 | return -EINVAL; |
6313 | } | |
6314 | ||
9c5f8a10 | 6315 | vlen = btf_type_vlen(t); |
7ce4dc3e YS |
6316 | if (BTF_INFO_KIND(t->info) == BTF_KIND_UNION && vlen != 1 && !(*flag & PTR_UNTRUSTED)) |
6317 | /* | |
6318 | * walking unions yields untrusted pointers | |
6319 | * with exception of __bpf_md_ptr and other | |
6320 | * unions with a single member | |
6321 | */ | |
6322 | *flag |= PTR_UNTRUSTED; | |
6323 | ||
976aba00 | 6324 | if (off + size > t->size) { |
9c5f8a10 YS |
6325 | /* If the last element is a variable size array, we may |
6326 | * need to relax the rule. | |
6327 | */ | |
6328 | struct btf_array *array_elem; | |
6329 | ||
6330 | if (vlen == 0) | |
6331 | goto error; | |
6332 | ||
6333 | member = btf_type_member(t) + vlen - 1; | |
22dc4a0f | 6334 | mtype = btf_type_skip_modifiers(btf, member->type, |
9c5f8a10 YS |
6335 | NULL); |
6336 | if (!btf_type_is_array(mtype)) | |
6337 | goto error; | |
6338 | ||
6339 | array_elem = (struct btf_array *)(mtype + 1); | |
6340 | if (array_elem->nelems != 0) | |
6341 | goto error; | |
6342 | ||
8293eb99 | 6343 | moff = __btf_member_bit_offset(t, member) / 8; |
9c5f8a10 YS |
6344 | if (off < moff) |
6345 | goto error; | |
6346 | ||
2569c7b8 | 6347 | /* allow structure and integer */ |
22dc4a0f | 6348 | t = btf_type_skip_modifiers(btf, array_elem->type, |
dafe58fc | 6349 | NULL); |
2569c7b8 FZ |
6350 | |
6351 | if (btf_type_is_int(t)) | |
6352 | return WALK_SCALAR; | |
6353 | ||
dafe58fc | 6354 | if (!btf_type_is_struct(t)) |
9c5f8a10 YS |
6355 | goto error; |
6356 | ||
dafe58fc JO |
6357 | off = (off - moff) % t->size; |
6358 | goto again; | |
9c5f8a10 YS |
6359 | |
6360 | error: | |
976aba00 MKL |
6361 | bpf_log(log, "access beyond struct %s at off %u size %u\n", |
6362 | tname, off, size); | |
6363 | return -EACCES; | |
6364 | } | |
9e15db66 | 6365 | |
976aba00 | 6366 | for_each_member(i, t, member) { |
7e3617a7 | 6367 | /* offset of the field in bytes */ |
8293eb99 | 6368 | moff = __btf_member_bit_offset(t, member) / 8; |
7e3617a7 | 6369 | if (off + size <= moff) |
9e15db66 AS |
6370 | /* won't find anything, field is already too far */ |
6371 | break; | |
976aba00 | 6372 | |
8293eb99 AS |
6373 | if (__btf_member_bitfield_size(t, member)) { |
6374 | u32 end_bit = __btf_member_bit_offset(t, member) + | |
6375 | __btf_member_bitfield_size(t, member); | |
976aba00 MKL |
6376 | |
6377 | /* off <= moff instead of off == moff because clang | |
6378 | * does not generate a BTF member for anonymous | |
6379 | * bitfield like the ":16" here: | |
6380 | * struct { | |
6381 | * int :16; | |
6382 | * int x:8; | |
6383 | * }; | |
6384 | */ | |
6385 | if (off <= moff && | |
6386 | BITS_ROUNDUP_BYTES(end_bit) <= off + size) | |
1c6d28a6 | 6387 | return WALK_SCALAR; |
976aba00 MKL |
6388 | |
6389 | /* off may be accessing a following member | |
6390 | * | |
6391 | * or | |
6392 | * | |
6393 | * Doing partial access at either end of this | |
6394 | * bitfield. Continue on this case also to | |
6395 | * treat it as not accessing this bitfield | |
6396 | * and eventually error out as field not | |
6397 | * found to keep it simple. | |
6398 | * It could be relaxed if there was a legit | |
6399 | * partial access case later. | |
6400 | */ | |
6401 | continue; | |
6402 | } | |
6403 | ||
7e3617a7 MKL |
6404 | /* In case of "off" is pointing to holes of a struct */ |
6405 | if (off < moff) | |
976aba00 | 6406 | break; |
9e15db66 AS |
6407 | |
6408 | /* type of the field */ | |
1c6d28a6 | 6409 | mid = member->type; |
22dc4a0f AN |
6410 | mtype = btf_type_by_id(btf, member->type); |
6411 | mname = __btf_name_by_offset(btf, member->name_off); | |
9e15db66 | 6412 | |
22dc4a0f | 6413 | mtype = __btf_resolve_size(btf, mtype, &msize, |
1c6d28a6 JO |
6414 | &elem_type, &elem_id, &total_nelems, |
6415 | &mid); | |
7e3617a7 | 6416 | if (IS_ERR(mtype)) { |
9e15db66 AS |
6417 | bpf_log(log, "field %s doesn't have size\n", mname); |
6418 | return -EFAULT; | |
6419 | } | |
7e3617a7 MKL |
6420 | |
6421 | mtrue_end = moff + msize; | |
6422 | if (off >= mtrue_end) | |
9e15db66 AS |
6423 | /* no overlap with member, keep iterating */ |
6424 | continue; | |
7e3617a7 MKL |
6425 | |
6426 | if (btf_type_is_array(mtype)) { | |
6427 | u32 elem_idx; | |
6428 | ||
6298399b | 6429 | /* __btf_resolve_size() above helps to |
7e3617a7 MKL |
6430 | * linearize a multi-dimensional array. |
6431 | * | |
6432 | * The logic here is treating an array | |
6433 | * in a struct as the following way: | |
6434 | * | |
6435 | * struct outer { | |
6436 | * struct inner array[2][2]; | |
6437 | * }; | |
6438 | * | |
6439 | * looks like: | |
6440 | * | |
6441 | * struct outer { | |
6442 | * struct inner array_elem0; | |
6443 | * struct inner array_elem1; | |
6444 | * struct inner array_elem2; | |
6445 | * struct inner array_elem3; | |
6446 | * }; | |
6447 | * | |
6448 | * When accessing outer->array[1][0], it moves | |
6449 | * moff to "array_elem2", set mtype to | |
6450 | * "struct inner", and msize also becomes | |
6451 | * sizeof(struct inner). Then most of the | |
6452 | * remaining logic will fall through without | |
6453 | * caring the current member is an array or | |
6454 | * not. | |
6455 | * | |
6456 | * Unlike mtype/msize/moff, mtrue_end does not | |
6457 | * change. The naming difference ("_true") tells | |
6458 | * that it is not always corresponding to | |
6459 | * the current mtype/msize/moff. | |
6460 | * It is the true end of the current | |
6461 | * member (i.e. array in this case). That | |
6462 | * will allow an int array to be accessed like | |
6463 | * a scratch space, | |
6464 | * i.e. allow access beyond the size of | |
6465 | * the array's element as long as it is | |
6466 | * within the mtrue_end boundary. | |
6467 | */ | |
6468 | ||
6469 | /* skip empty array */ | |
6470 | if (moff == mtrue_end) | |
6471 | continue; | |
6472 | ||
6473 | msize /= total_nelems; | |
6474 | elem_idx = (off - moff) / msize; | |
6475 | moff += elem_idx * msize; | |
6476 | mtype = elem_type; | |
1c6d28a6 | 6477 | mid = elem_id; |
7e3617a7 MKL |
6478 | } |
6479 | ||
9e15db66 AS |
6480 | /* the 'off' we're looking for is either equal to start |
6481 | * of this field or inside of this struct | |
6482 | */ | |
6483 | if (btf_type_is_struct(mtype)) { | |
6484 | /* our field must be inside that union or struct */ | |
6485 | t = mtype; | |
6486 | ||
1c6d28a6 JO |
6487 | /* return if the offset matches the member offset */ |
6488 | if (off == moff) { | |
6489 | *next_btf_id = mid; | |
6490 | return WALK_STRUCT; | |
6491 | } | |
6492 | ||
9e15db66 | 6493 | /* adjust offset we're looking for */ |
7e3617a7 | 6494 | off -= moff; |
9e15db66 AS |
6495 | goto again; |
6496 | } | |
9e15db66 AS |
6497 | |
6498 | if (btf_type_is_ptr(mtype)) { | |
c6f1bfe8 YS |
6499 | const struct btf_type *stype, *t; |
6500 | enum bpf_type_flag tmp_flag = 0; | |
257af63d | 6501 | u32 id; |
9e15db66 | 6502 | |
7e3617a7 MKL |
6503 | if (msize != size || off != moff) { |
6504 | bpf_log(log, | |
6505 | "cannot access ptr member %s with moff %u in struct %s with off %u size %u\n", | |
6506 | mname, moff, tname, off, size); | |
6507 | return -EACCES; | |
6508 | } | |
c6f1bfe8 | 6509 | |
5844101a | 6510 | /* check type tag */ |
c6f1bfe8 YS |
6511 | t = btf_type_by_id(btf, mtype->type); |
6512 | if (btf_type_is_type_tag(t)) { | |
6513 | tag_value = __btf_name_by_offset(btf, t->name_off); | |
5844101a | 6514 | /* check __user tag */ |
c6f1bfe8 YS |
6515 | if (strcmp(tag_value, "user") == 0) |
6516 | tmp_flag = MEM_USER; | |
5844101a HL |
6517 | /* check __percpu tag */ |
6518 | if (strcmp(tag_value, "percpu") == 0) | |
6519 | tmp_flag = MEM_PERCPU; | |
9bb00b28 YS |
6520 | /* check __rcu tag */ |
6521 | if (strcmp(tag_value, "rcu") == 0) | |
6522 | tmp_flag = MEM_RCU; | |
c6f1bfe8 YS |
6523 | } |
6524 | ||
22dc4a0f | 6525 | stype = btf_type_skip_modifiers(btf, mtype->type, &id); |
9e15db66 | 6526 | if (btf_type_is_struct(stype)) { |
257af63d | 6527 | *next_btf_id = id; |
6fcd486b | 6528 | *flag |= tmp_flag; |
63260df1 AS |
6529 | if (field_name) |
6530 | *field_name = mname; | |
1c6d28a6 | 6531 | return WALK_PTR; |
9e15db66 AS |
6532 | } |
6533 | } | |
7e3617a7 MKL |
6534 | |
6535 | /* Allow more flexible access within an int as long as | |
6536 | * it is within mtrue_end. | |
6537 | * Since mtrue_end could be the end of an array, | |
6538 | * that also allows using an array of int as a scratch | |
6539 | * space. e.g. skb->cb[]. | |
6540 | */ | |
33937607 | 6541 | if (off + size > mtrue_end && !(*flag & PTR_UNTRUSTED)) { |
7e3617a7 MKL |
6542 | bpf_log(log, |
6543 | "access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n", | |
6544 | mname, mtrue_end, tname, off, size); | |
6545 | return -EACCES; | |
6546 | } | |
6547 | ||
1c6d28a6 | 6548 | return WALK_SCALAR; |
9e15db66 AS |
6549 | } |
6550 | bpf_log(log, "struct %s doesn't have field at offset %d\n", tname, off); | |
6551 | return -EINVAL; | |
6552 | } | |
6553 | ||
6728aea7 KKD |
6554 | int btf_struct_access(struct bpf_verifier_log *log, |
6555 | const struct bpf_reg_state *reg, | |
6556 | int off, int size, enum bpf_access_type atype __maybe_unused, | |
63260df1 AS |
6557 | u32 *next_btf_id, enum bpf_type_flag *flag, |
6558 | const char **field_name) | |
1c6d28a6 | 6559 | { |
6728aea7 | 6560 | const struct btf *btf = reg->btf; |
c6f1bfe8 | 6561 | enum bpf_type_flag tmp_flag = 0; |
6728aea7 KKD |
6562 | const struct btf_type *t; |
6563 | u32 id = reg->btf_id; | |
1c6d28a6 | 6564 | int err; |
1c6d28a6 | 6565 | |
8ffa5cc1 KKD |
6566 | while (type_is_alloc(reg->type)) { |
6567 | struct btf_struct_meta *meta; | |
6568 | struct btf_record *rec; | |
6569 | int i; | |
6570 | ||
6571 | meta = btf_find_struct_meta(btf, id); | |
6572 | if (!meta) | |
6573 | break; | |
6574 | rec = meta->record; | |
6575 | for (i = 0; i < rec->cnt; i++) { | |
6576 | struct btf_field *field = &rec->fields[i]; | |
6577 | u32 offset = field->offset; | |
6578 | if (off < offset + btf_field_type_size(field->type) && offset < off + size) { | |
6579 | bpf_log(log, | |
6580 | "direct access to %s is disallowed\n", | |
6581 | btf_field_type_name(field->type)); | |
6582 | return -EACCES; | |
6583 | } | |
6584 | } | |
6585 | break; | |
6586 | } | |
6587 | ||
6728aea7 | 6588 | t = btf_type_by_id(btf, id); |
1c6d28a6 | 6589 | do { |
63260df1 | 6590 | err = btf_struct_walk(log, btf, t, off, size, &id, &tmp_flag, field_name); |
1c6d28a6 JO |
6591 | |
6592 | switch (err) { | |
6593 | case WALK_PTR: | |
282de143 KKD |
6594 | /* For local types, the destination register cannot |
6595 | * become a pointer again. | |
6596 | */ | |
6597 | if (type_is_alloc(reg->type)) | |
6598 | return SCALAR_VALUE; | |
1c6d28a6 JO |
6599 | /* If we found the pointer or scalar on t+off, |
6600 | * we're done. | |
6601 | */ | |
6602 | *next_btf_id = id; | |
c6f1bfe8 | 6603 | *flag = tmp_flag; |
1c6d28a6 JO |
6604 | return PTR_TO_BTF_ID; |
6605 | case WALK_SCALAR: | |
6606 | return SCALAR_VALUE; | |
6607 | case WALK_STRUCT: | |
6608 | /* We found nested struct, so continue the search | |
6609 | * by diving in it. At this point the offset is | |
6610 | * aligned with the new type, so set it to 0. | |
6611 | */ | |
22dc4a0f | 6612 | t = btf_type_by_id(btf, id); |
1c6d28a6 JO |
6613 | off = 0; |
6614 | break; | |
6615 | default: | |
6616 | /* It's either error or unknown return value.. | |
6617 | * scream and leave. | |
6618 | */ | |
6619 | if (WARN_ONCE(err > 0, "unknown btf_struct_walk return value")) | |
6620 | return -EINVAL; | |
6621 | return err; | |
6622 | } | |
6623 | } while (t); | |
6624 | ||
6625 | return -EINVAL; | |
6626 | } | |
6627 | ||
22dc4a0f AN |
6628 | /* Check that two BTF types, each specified as an BTF object + id, are exactly |
6629 | * the same. Trivial ID check is not enough due to module BTFs, because we can | |
6630 | * end up with two different module BTFs, but IDs point to the common type in | |
6631 | * vmlinux BTF. | |
6632 | */ | |
00b85860 KKD |
6633 | bool btf_types_are_same(const struct btf *btf1, u32 id1, |
6634 | const struct btf *btf2, u32 id2) | |
22dc4a0f AN |
6635 | { |
6636 | if (id1 != id2) | |
6637 | return false; | |
6638 | if (btf1 == btf2) | |
6639 | return true; | |
6640 | return btf_type_by_id(btf1, id1) == btf_type_by_id(btf2, id2); | |
6641 | } | |
6642 | ||
faaf4a79 | 6643 | bool btf_struct_ids_match(struct bpf_verifier_log *log, |
22dc4a0f | 6644 | const struct btf *btf, u32 id, int off, |
2ab3b380 KKD |
6645 | const struct btf *need_btf, u32 need_type_id, |
6646 | bool strict) | |
faaf4a79 JO |
6647 | { |
6648 | const struct btf_type *type; | |
7ce4dc3e | 6649 | enum bpf_type_flag flag = 0; |
faaf4a79 JO |
6650 | int err; |
6651 | ||
6652 | /* Are we already done? */ | |
22dc4a0f | 6653 | if (off == 0 && btf_types_are_same(btf, id, need_btf, need_type_id)) |
faaf4a79 | 6654 | return true; |
2ab3b380 KKD |
6655 | /* In case of strict type match, we do not walk struct, the top level |
6656 | * type match must succeed. When strict is true, off should have already | |
6657 | * been 0. | |
6658 | */ | |
6659 | if (strict) | |
6660 | return false; | |
faaf4a79 | 6661 | again: |
22dc4a0f | 6662 | type = btf_type_by_id(btf, id); |
faaf4a79 JO |
6663 | if (!type) |
6664 | return false; | |
63260df1 | 6665 | err = btf_struct_walk(log, btf, type, off, 1, &id, &flag, NULL); |
faaf4a79 JO |
6666 | if (err != WALK_STRUCT) |
6667 | return false; | |
6668 | ||
6669 | /* We found nested struct object. If it matches | |
6670 | * the requested ID, we're done. Otherwise let's | |
6671 | * continue the search with offset 0 in the new | |
6672 | * type. | |
6673 | */ | |
22dc4a0f | 6674 | if (!btf_types_are_same(btf, id, need_btf, need_type_id)) { |
faaf4a79 JO |
6675 | off = 0; |
6676 | goto again; | |
6677 | } | |
6678 | ||
6679 | return true; | |
6680 | } | |
6681 | ||
fec56f58 | 6682 | static int __get_type_size(struct btf *btf, u32 btf_id, |
a00ed843 | 6683 | const struct btf_type **ret_type) |
fec56f58 AS |
6684 | { |
6685 | const struct btf_type *t; | |
6686 | ||
a00ed843 | 6687 | *ret_type = btf_type_by_id(btf, 0); |
fec56f58 AS |
6688 | if (!btf_id) |
6689 | /* void */ | |
6690 | return 0; | |
6691 | t = btf_type_by_id(btf, btf_id); | |
6692 | while (t && btf_type_is_modifier(t)) | |
6693 | t = btf_type_by_id(btf, t->type); | |
a00ed843 | 6694 | if (!t) |
fec56f58 | 6695 | return -EINVAL; |
a00ed843 | 6696 | *ret_type = t; |
fec56f58 AS |
6697 | if (btf_type_is_ptr(t)) |
6698 | /* kernel size of pointer. Not BPF's size of pointer*/ | |
6699 | return sizeof(void *); | |
720e6a43 | 6700 | if (btf_type_is_int(t) || btf_is_any_enum(t) || __btf_type_is_struct(t)) |
fec56f58 | 6701 | return t->size; |
fec56f58 AS |
6702 | return -EINVAL; |
6703 | } | |
6704 | ||
49f67f39 IL |
6705 | static u8 __get_type_fmodel_flags(const struct btf_type *t) |
6706 | { | |
6707 | u8 flags = 0; | |
6708 | ||
6709 | if (__btf_type_is_struct(t)) | |
6710 | flags |= BTF_FMODEL_STRUCT_ARG; | |
6711 | if (btf_type_is_signed_int(t)) | |
6712 | flags |= BTF_FMODEL_SIGNED_ARG; | |
6713 | ||
6714 | return flags; | |
6715 | } | |
6716 | ||
fec56f58 AS |
6717 | int btf_distill_func_proto(struct bpf_verifier_log *log, |
6718 | struct btf *btf, | |
6719 | const struct btf_type *func, | |
6720 | const char *tname, | |
6721 | struct btf_func_model *m) | |
6722 | { | |
6723 | const struct btf_param *args; | |
6724 | const struct btf_type *t; | |
6725 | u32 i, nargs; | |
6726 | int ret; | |
6727 | ||
5b92a28a AS |
6728 | if (!func) { |
6729 | /* BTF function prototype doesn't match the verifier types. | |
523a4cf4 | 6730 | * Fall back to MAX_BPF_FUNC_REG_ARGS u64 args. |
5b92a28a | 6731 | */ |
720e6a43 | 6732 | for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++) { |
5b92a28a | 6733 | m->arg_size[i] = 8; |
720e6a43 YS |
6734 | m->arg_flags[i] = 0; |
6735 | } | |
5b92a28a | 6736 | m->ret_size = 8; |
49f67f39 | 6737 | m->ret_flags = 0; |
523a4cf4 | 6738 | m->nr_args = MAX_BPF_FUNC_REG_ARGS; |
5b92a28a AS |
6739 | return 0; |
6740 | } | |
fec56f58 AS |
6741 | args = (const struct btf_param *)(func + 1); |
6742 | nargs = btf_type_vlen(func); | |
c29a4920 | 6743 | if (nargs > MAX_BPF_FUNC_ARGS) { |
fec56f58 AS |
6744 | bpf_log(log, |
6745 | "The function %s has %d arguments. Too many.\n", | |
6746 | tname, nargs); | |
6747 | return -EINVAL; | |
6748 | } | |
6749 | ret = __get_type_size(btf, func->type, &t); | |
720e6a43 | 6750 | if (ret < 0 || __btf_type_is_struct(t)) { |
fec56f58 AS |
6751 | bpf_log(log, |
6752 | "The function %s return type %s is unsupported.\n", | |
571f9738 | 6753 | tname, btf_type_str(t)); |
fec56f58 AS |
6754 | return -EINVAL; |
6755 | } | |
6756 | m->ret_size = ret; | |
49f67f39 | 6757 | m->ret_flags = __get_type_fmodel_flags(t); |
fec56f58 AS |
6758 | |
6759 | for (i = 0; i < nargs; i++) { | |
31379397 JO |
6760 | if (i == nargs - 1 && args[i].type == 0) { |
6761 | bpf_log(log, | |
6762 | "The function %s with variable args is unsupported.\n", | |
6763 | tname); | |
6764 | return -EINVAL; | |
6765 | } | |
fec56f58 | 6766 | ret = __get_type_size(btf, args[i].type, &t); |
720e6a43 YS |
6767 | |
6768 | /* No support of struct argument size greater than 16 bytes */ | |
6769 | if (ret < 0 || ret > 16) { | |
fec56f58 AS |
6770 | bpf_log(log, |
6771 | "The function %s arg%d type %s is unsupported.\n", | |
571f9738 | 6772 | tname, i, btf_type_str(t)); |
fec56f58 AS |
6773 | return -EINVAL; |
6774 | } | |
31379397 JO |
6775 | if (ret == 0) { |
6776 | bpf_log(log, | |
6777 | "The function %s has malformed void argument.\n", | |
6778 | tname); | |
6779 | return -EINVAL; | |
6780 | } | |
fec56f58 | 6781 | m->arg_size[i] = ret; |
49f67f39 | 6782 | m->arg_flags[i] = __get_type_fmodel_flags(t); |
fec56f58 AS |
6783 | } |
6784 | m->nr_args = nargs; | |
6785 | return 0; | |
6786 | } | |
6787 | ||
be8704ff AS |
6788 | /* Compare BTFs of two functions assuming only scalars and pointers to context. |
6789 | * t1 points to BTF_KIND_FUNC in btf1 | |
6790 | * t2 points to BTF_KIND_FUNC in btf2 | |
6791 | * Returns: | |
6792 | * EINVAL - function prototype mismatch | |
6793 | * EFAULT - verifier bug | |
6794 | * 0 - 99% match. The last 1% is validated by the verifier. | |
6795 | */ | |
2bf0eb9b HY |
6796 | static int btf_check_func_type_match(struct bpf_verifier_log *log, |
6797 | struct btf *btf1, const struct btf_type *t1, | |
6798 | struct btf *btf2, const struct btf_type *t2) | |
be8704ff AS |
6799 | { |
6800 | const struct btf_param *args1, *args2; | |
6801 | const char *fn1, *fn2, *s1, *s2; | |
6802 | u32 nargs1, nargs2, i; | |
6803 | ||
6804 | fn1 = btf_name_by_offset(btf1, t1->name_off); | |
6805 | fn2 = btf_name_by_offset(btf2, t2->name_off); | |
6806 | ||
6807 | if (btf_func_linkage(t1) != BTF_FUNC_GLOBAL) { | |
6808 | bpf_log(log, "%s() is not a global function\n", fn1); | |
6809 | return -EINVAL; | |
6810 | } | |
6811 | if (btf_func_linkage(t2) != BTF_FUNC_GLOBAL) { | |
6812 | bpf_log(log, "%s() is not a global function\n", fn2); | |
6813 | return -EINVAL; | |
6814 | } | |
6815 | ||
6816 | t1 = btf_type_by_id(btf1, t1->type); | |
6817 | if (!t1 || !btf_type_is_func_proto(t1)) | |
6818 | return -EFAULT; | |
6819 | t2 = btf_type_by_id(btf2, t2->type); | |
6820 | if (!t2 || !btf_type_is_func_proto(t2)) | |
6821 | return -EFAULT; | |
6822 | ||
6823 | args1 = (const struct btf_param *)(t1 + 1); | |
6824 | nargs1 = btf_type_vlen(t1); | |
6825 | args2 = (const struct btf_param *)(t2 + 1); | |
6826 | nargs2 = btf_type_vlen(t2); | |
6827 | ||
6828 | if (nargs1 != nargs2) { | |
6829 | bpf_log(log, "%s() has %d args while %s() has %d args\n", | |
6830 | fn1, nargs1, fn2, nargs2); | |
6831 | return -EINVAL; | |
6832 | } | |
6833 | ||
6834 | t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); | |
6835 | t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); | |
6836 | if (t1->info != t2->info) { | |
6837 | bpf_log(log, | |
6838 | "Return type %s of %s() doesn't match type %s of %s()\n", | |
6839 | btf_type_str(t1), fn1, | |
6840 | btf_type_str(t2), fn2); | |
6841 | return -EINVAL; | |
6842 | } | |
6843 | ||
6844 | for (i = 0; i < nargs1; i++) { | |
6845 | t1 = btf_type_skip_modifiers(btf1, args1[i].type, NULL); | |
6846 | t2 = btf_type_skip_modifiers(btf2, args2[i].type, NULL); | |
6847 | ||
6848 | if (t1->info != t2->info) { | |
6849 | bpf_log(log, "arg%d in %s() is %s while %s() has %s\n", | |
6850 | i, fn1, btf_type_str(t1), | |
6851 | fn2, btf_type_str(t2)); | |
6852 | return -EINVAL; | |
6853 | } | |
6854 | if (btf_type_has_size(t1) && t1->size != t2->size) { | |
6855 | bpf_log(log, | |
6856 | "arg%d in %s() has size %d while %s() has %d\n", | |
6857 | i, fn1, t1->size, | |
6858 | fn2, t2->size); | |
6859 | return -EINVAL; | |
6860 | } | |
6861 | ||
6862 | /* global functions are validated with scalars and pointers | |
6863 | * to context only. And only global functions can be replaced. | |
6864 | * Hence type check only those types. | |
6865 | */ | |
6089fb32 | 6866 | if (btf_type_is_int(t1) || btf_is_any_enum(t1)) |
be8704ff AS |
6867 | continue; |
6868 | if (!btf_type_is_ptr(t1)) { | |
6869 | bpf_log(log, | |
6870 | "arg%d in %s() has unrecognized type\n", | |
6871 | i, fn1); | |
6872 | return -EINVAL; | |
6873 | } | |
6874 | t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); | |
6875 | t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); | |
6876 | if (!btf_type_is_struct(t1)) { | |
6877 | bpf_log(log, | |
6878 | "arg%d in %s() is not a pointer to context\n", | |
6879 | i, fn1); | |
6880 | return -EINVAL; | |
6881 | } | |
6882 | if (!btf_type_is_struct(t2)) { | |
6883 | bpf_log(log, | |
6884 | "arg%d in %s() is not a pointer to context\n", | |
6885 | i, fn2); | |
6886 | return -EINVAL; | |
6887 | } | |
6888 | /* This is an optional check to make program writing easier. | |
6889 | * Compare names of structs and report an error to the user. | |
6890 | * btf_prepare_func_args() already checked that t2 struct | |
6891 | * is a context type. btf_prepare_func_args() will check | |
6892 | * later that t1 struct is a context type as well. | |
6893 | */ | |
6894 | s1 = btf_name_by_offset(btf1, t1->name_off); | |
6895 | s2 = btf_name_by_offset(btf2, t2->name_off); | |
6896 | if (strcmp(s1, s2)) { | |
6897 | bpf_log(log, | |
6898 | "arg%d %s(struct %s *) doesn't match %s(struct %s *)\n", | |
6899 | i, fn1, s1, fn2, s2); | |
6900 | return -EINVAL; | |
6901 | } | |
6902 | } | |
6903 | return 0; | |
6904 | } | |
6905 | ||
6906 | /* Compare BTFs of given program with BTF of target program */ | |
efc68158 | 6907 | int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog, |
be8704ff AS |
6908 | struct btf *btf2, const struct btf_type *t2) |
6909 | { | |
6910 | struct btf *btf1 = prog->aux->btf; | |
6911 | const struct btf_type *t1; | |
6912 | u32 btf_id = 0; | |
6913 | ||
6914 | if (!prog->aux->func_info) { | |
efc68158 | 6915 | bpf_log(log, "Program extension requires BTF\n"); |
be8704ff AS |
6916 | return -EINVAL; |
6917 | } | |
6918 | ||
6919 | btf_id = prog->aux->func_info[0].type_id; | |
6920 | if (!btf_id) | |
6921 | return -EFAULT; | |
6922 | ||
6923 | t1 = btf_type_by_id(btf1, btf_id); | |
6924 | if (!t1 || !btf_type_is_func(t1)) | |
6925 | return -EFAULT; | |
6926 | ||
efc68158 | 6927 | return btf_check_func_type_match(log, btf1, t1, btf2, t2); |
be8704ff AS |
6928 | } |
6929 | ||
a64bfe61 AN |
6930 | static bool btf_is_dynptr_ptr(const struct btf *btf, const struct btf_type *t) |
6931 | { | |
6932 | const char *name; | |
6933 | ||
6934 | t = btf_type_by_id(btf, t->type); /* skip PTR */ | |
6935 | ||
6936 | while (btf_type_is_modifier(t)) | |
6937 | t = btf_type_by_id(btf, t->type); | |
6938 | ||
6939 | /* allow either struct or struct forward declaration */ | |
6940 | if (btf_type_is_struct(t) || | |
6941 | (btf_type_is_fwd(t) && btf_type_kflag(t) == 0)) { | |
6942 | name = btf_str_by_offset(btf, t->name_off); | |
6943 | return name && strcmp(name, "bpf_dynptr") == 0; | |
6944 | } | |
6945 | ||
6946 | return false; | |
6947 | } | |
6948 | ||
4ba1d0f2 AN |
6949 | /* Process BTF of a function to produce high-level expectation of function |
6950 | * arguments (like ARG_PTR_TO_CTX, or ARG_PTR_TO_MEM, etc). This information | |
6951 | * is cached in subprog info for reuse. | |
51c39bb1 AS |
6952 | * Returns: |
6953 | * EFAULT - there is a verifier bug. Abort verification. | |
6954 | * EINVAL - cannot convert BTF. | |
4ba1d0f2 | 6955 | * 0 - Successfully processed BTF and constructed argument expectations. |
51c39bb1 | 6956 | */ |
4ba1d0f2 | 6957 | int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog) |
51c39bb1 | 6958 | { |
e26080d0 | 6959 | bool is_global = subprog_aux(env, subprog)->linkage == BTF_FUNC_GLOBAL; |
4ba1d0f2 | 6960 | struct bpf_subprog_info *sub = subprog_info(env, subprog); |
51c39bb1 AS |
6961 | struct bpf_verifier_log *log = &env->log; |
6962 | struct bpf_prog *prog = env->prog; | |
be8704ff | 6963 | enum bpf_prog_type prog_type = prog->type; |
51c39bb1 AS |
6964 | struct btf *btf = prog->aux->btf; |
6965 | const struct btf_param *args; | |
94e1c70a | 6966 | const struct btf_type *t, *ref_t, *fn_t; |
51c39bb1 AS |
6967 | u32 i, nargs, btf_id; |
6968 | const char *tname; | |
6969 | ||
4ba1d0f2 AN |
6970 | if (sub->args_cached) |
6971 | return 0; | |
6972 | ||
e26080d0 | 6973 | if (!prog->aux->func_info) { |
51c39bb1 AS |
6974 | bpf_log(log, "Verifier bug\n"); |
6975 | return -EFAULT; | |
6976 | } | |
6977 | ||
6978 | btf_id = prog->aux->func_info[subprog].type_id; | |
6979 | if (!btf_id) { | |
e26080d0 AN |
6980 | if (!is_global) /* not fatal for static funcs */ |
6981 | return -EINVAL; | |
51c39bb1 AS |
6982 | bpf_log(log, "Global functions need valid BTF\n"); |
6983 | return -EFAULT; | |
6984 | } | |
6985 | ||
94e1c70a AN |
6986 | fn_t = btf_type_by_id(btf, btf_id); |
6987 | if (!fn_t || !btf_type_is_func(fn_t)) { | |
51c39bb1 AS |
6988 | /* These checks were already done by the verifier while loading |
6989 | * struct bpf_func_info | |
6990 | */ | |
6991 | bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n", | |
6992 | subprog); | |
6993 | return -EFAULT; | |
6994 | } | |
94e1c70a | 6995 | tname = btf_name_by_offset(btf, fn_t->name_off); |
51c39bb1 | 6996 | |
51c39bb1 AS |
6997 | if (prog->aux->func_info_aux[subprog].unreliable) { |
6998 | bpf_log(log, "Verifier bug in function %s()\n", tname); | |
6999 | return -EFAULT; | |
7000 | } | |
be8704ff | 7001 | if (prog_type == BPF_PROG_TYPE_EXT) |
3aac1ead | 7002 | prog_type = prog->aux->dst_prog->type; |
51c39bb1 | 7003 | |
94e1c70a | 7004 | t = btf_type_by_id(btf, fn_t->type); |
51c39bb1 AS |
7005 | if (!t || !btf_type_is_func_proto(t)) { |
7006 | bpf_log(log, "Invalid type of function %s()\n", tname); | |
7007 | return -EFAULT; | |
7008 | } | |
7009 | args = (const struct btf_param *)(t + 1); | |
7010 | nargs = btf_type_vlen(t); | |
523a4cf4 DB |
7011 | if (nargs > MAX_BPF_FUNC_REG_ARGS) { |
7012 | bpf_log(log, "Global function %s() with %d > %d args. Buggy compiler.\n", | |
7013 | tname, nargs, MAX_BPF_FUNC_REG_ARGS); | |
51c39bb1 AS |
7014 | return -EINVAL; |
7015 | } | |
b9ae0c9d | 7016 | /* check that function returns int, exception cb also requires this */ |
51c39bb1 AS |
7017 | t = btf_type_by_id(btf, t->type); |
7018 | while (btf_type_is_modifier(t)) | |
7019 | t = btf_type_by_id(btf, t->type); | |
6089fb32 | 7020 | if (!btf_type_is_int(t) && !btf_is_any_enum(t)) { |
51c39bb1 AS |
7021 | bpf_log(log, |
7022 | "Global function %s() doesn't return scalar. Only those are supported.\n", | |
7023 | tname); | |
7024 | return -EINVAL; | |
7025 | } | |
7026 | /* Convert BTF function arguments into verifier types. | |
7027 | * Only PTR_TO_CTX and SCALAR are supported atm. | |
7028 | */ | |
7029 | for (i = 0; i < nargs; i++) { | |
94e1c70a AN |
7030 | bool is_nonnull = false; |
7031 | const char *tag; | |
7032 | ||
51c39bb1 | 7033 | t = btf_type_by_id(btf, args[i].type); |
94e1c70a AN |
7034 | |
7035 | tag = btf_find_decl_tag_value(btf, fn_t, i, "arg:"); | |
7036 | if (IS_ERR(tag) && PTR_ERR(tag) == -ENOENT) { | |
7037 | tag = NULL; | |
7038 | } else if (IS_ERR(tag)) { | |
7039 | bpf_log(log, "arg#%d type's tag fetching failure: %ld\n", i, PTR_ERR(tag)); | |
7040 | return PTR_ERR(tag); | |
7041 | } | |
7042 | /* 'arg:<tag>' decl_tag takes precedence over derivation of | |
7043 | * register type from BTF type itself | |
7044 | */ | |
7045 | if (tag) { | |
7046 | /* disallow arg tags in static subprogs */ | |
7047 | if (!is_global) { | |
7048 | bpf_log(log, "arg#%d type tag is not supported in static functions\n", i); | |
7049 | return -EOPNOTSUPP; | |
7050 | } | |
7051 | if (strcmp(tag, "ctx") == 0) { | |
7052 | sub->args[i].arg_type = ARG_PTR_TO_CTX; | |
7053 | continue; | |
7054 | } | |
7055 | if (strcmp(tag, "nonnull") == 0) | |
7056 | is_nonnull = true; | |
7057 | } | |
7058 | ||
51c39bb1 AS |
7059 | while (btf_type_is_modifier(t)) |
7060 | t = btf_type_by_id(btf, t->type); | |
6089fb32 | 7061 | if (btf_type_is_int(t) || btf_is_any_enum(t)) { |
4ba1d0f2 | 7062 | sub->args[i].arg_type = ARG_ANYTHING; |
51c39bb1 AS |
7063 | continue; |
7064 | } | |
e26080d0 AN |
7065 | if (btf_type_is_ptr(t) && btf_get_prog_ctx_type(log, btf, t, prog_type, i)) { |
7066 | sub->args[i].arg_type = ARG_PTR_TO_CTX; | |
7067 | continue; | |
7068 | } | |
a64bfe61 AN |
7069 | if (btf_type_is_ptr(t) && btf_is_dynptr_ptr(btf, t)) { |
7070 | sub->args[i].arg_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY; | |
7071 | continue; | |
7072 | } | |
e26080d0 | 7073 | if (is_global && btf_type_is_ptr(t)) { |
4ba1d0f2 AN |
7074 | u32 mem_size; |
7075 | ||
e5069b9c | 7076 | t = btf_type_skip_modifiers(btf, t->type, NULL); |
4ba1d0f2 | 7077 | ref_t = btf_resolve_size(btf, t, &mem_size); |
e5069b9c DB |
7078 | if (IS_ERR(ref_t)) { |
7079 | bpf_log(log, | |
7080 | "arg#%d reference type('%s %s') size cannot be determined: %ld\n", | |
7081 | i, btf_type_str(t), btf_name_by_offset(btf, t->name_off), | |
7082 | PTR_ERR(ref_t)); | |
7083 | return -EINVAL; | |
7084 | } | |
7085 | ||
94e1c70a | 7086 | sub->args[i].arg_type = is_nonnull ? ARG_PTR_TO_MEM : ARG_PTR_TO_MEM_OR_NULL; |
4ba1d0f2 | 7087 | sub->args[i].mem_size = mem_size; |
51c39bb1 AS |
7088 | continue; |
7089 | } | |
94e1c70a AN |
7090 | if (is_nonnull) { |
7091 | bpf_log(log, "arg#%d marked as non-null, but is not a pointer type\n", i); | |
7092 | return -EINVAL; | |
7093 | } | |
51c39bb1 | 7094 | bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n", |
571f9738 | 7095 | i, btf_type_str(t), tname); |
51c39bb1 AS |
7096 | return -EINVAL; |
7097 | } | |
4ba1d0f2 | 7098 | |
0ba97151 AN |
7099 | for (i = 0; i < nargs; i++) { |
7100 | const char *tag; | |
7101 | ||
7102 | if (sub->args[i].arg_type != ARG_PTR_TO_CTX) | |
7103 | continue; | |
7104 | ||
7105 | /* check if arg has "arg:ctx" tag */ | |
7106 | t = btf_type_by_id(btf, args[i].type); | |
7107 | tag = btf_find_decl_tag_value(btf, fn_t, i, "arg:"); | |
7108 | if (IS_ERR_OR_NULL(tag) || strcmp(tag, "ctx") != 0) | |
7109 | continue; | |
7110 | ||
7111 | if (btf_validate_prog_ctx_type(log, btf, t, i, prog_type, | |
7112 | prog->expected_attach_type)) | |
7113 | return -EINVAL; | |
7114 | } | |
7115 | ||
4ba1d0f2 AN |
7116 | sub->arg_cnt = nargs; |
7117 | sub->args_cached = true; | |
7118 | ||
8c1b6e69 AS |
7119 | return 0; |
7120 | } | |
7121 | ||
31d0bc81 AM |
7122 | static void btf_type_show(const struct btf *btf, u32 type_id, void *obj, |
7123 | struct btf_show *show) | |
7124 | { | |
7125 | const struct btf_type *t = btf_type_by_id(btf, type_id); | |
7126 | ||
7127 | show->btf = btf; | |
7128 | memset(&show->state, 0, sizeof(show->state)); | |
7129 | memset(&show->obj, 0, sizeof(show->obj)); | |
7130 | ||
7131 | btf_type_ops(t)->show(btf, t, type_id, obj, 0, show); | |
7132 | } | |
7133 | ||
7134 | static void btf_seq_show(struct btf_show *show, const char *fmt, | |
7135 | va_list args) | |
7136 | { | |
7137 | seq_vprintf((struct seq_file *)show->target, fmt, args); | |
7138 | } | |
7139 | ||
eb411377 AM |
7140 | int btf_type_seq_show_flags(const struct btf *btf, u32 type_id, |
7141 | void *obj, struct seq_file *m, u64 flags) | |
31d0bc81 AM |
7142 | { |
7143 | struct btf_show sseq; | |
7144 | ||
7145 | sseq.target = m; | |
7146 | sseq.showfn = btf_seq_show; | |
7147 | sseq.flags = flags; | |
7148 | ||
7149 | btf_type_show(btf, type_id, obj, &sseq); | |
7150 | ||
7151 | return sseq.state.status; | |
7152 | } | |
7153 | ||
b00b8dae MKL |
7154 | void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj, |
7155 | struct seq_file *m) | |
7156 | { | |
31d0bc81 AM |
7157 | (void) btf_type_seq_show_flags(btf, type_id, obj, m, |
7158 | BTF_SHOW_NONAME | BTF_SHOW_COMPACT | | |
7159 | BTF_SHOW_ZERO | BTF_SHOW_UNSAFE); | |
7160 | } | |
7161 | ||
7162 | struct btf_show_snprintf { | |
7163 | struct btf_show show; | |
7164 | int len_left; /* space left in string */ | |
7165 | int len; /* length we would have written */ | |
7166 | }; | |
7167 | ||
7168 | static void btf_snprintf_show(struct btf_show *show, const char *fmt, | |
7169 | va_list args) | |
7170 | { | |
7171 | struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show; | |
7172 | int len; | |
7173 | ||
7174 | len = vsnprintf(show->target, ssnprintf->len_left, fmt, args); | |
7175 | ||
7176 | if (len < 0) { | |
7177 | ssnprintf->len_left = 0; | |
7178 | ssnprintf->len = len; | |
58250ae3 | 7179 | } else if (len >= ssnprintf->len_left) { |
31d0bc81 AM |
7180 | /* no space, drive on to get length we would have written */ |
7181 | ssnprintf->len_left = 0; | |
7182 | ssnprintf->len += len; | |
7183 | } else { | |
7184 | ssnprintf->len_left -= len; | |
7185 | ssnprintf->len += len; | |
7186 | show->target += len; | |
7187 | } | |
7188 | } | |
7189 | ||
7190 | int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj, | |
7191 | char *buf, int len, u64 flags) | |
7192 | { | |
7193 | struct btf_show_snprintf ssnprintf; | |
7194 | ||
7195 | ssnprintf.show.target = buf; | |
7196 | ssnprintf.show.flags = flags; | |
7197 | ssnprintf.show.showfn = btf_snprintf_show; | |
7198 | ssnprintf.len_left = len; | |
7199 | ssnprintf.len = 0; | |
7200 | ||
7201 | btf_type_show(btf, type_id, obj, (struct btf_show *)&ssnprintf); | |
7202 | ||
c561d110 | 7203 | /* If we encountered an error, return it. */ |
31d0bc81 AM |
7204 | if (ssnprintf.show.state.status) |
7205 | return ssnprintf.show.state.status; | |
b00b8dae | 7206 | |
31d0bc81 AM |
7207 | /* Otherwise return length we would have written */ |
7208 | return ssnprintf.len; | |
b00b8dae | 7209 | } |
f56a653c | 7210 | |
3481e64b QM |
7211 | #ifdef CONFIG_PROC_FS |
7212 | static void bpf_btf_show_fdinfo(struct seq_file *m, struct file *filp) | |
7213 | { | |
7214 | const struct btf *btf = filp->private_data; | |
7215 | ||
7216 | seq_printf(m, "btf_id:\t%u\n", btf->id); | |
7217 | } | |
7218 | #endif | |
7219 | ||
f56a653c MKL |
7220 | static int btf_release(struct inode *inode, struct file *filp) |
7221 | { | |
7222 | btf_put(filp->private_data); | |
7223 | return 0; | |
7224 | } | |
7225 | ||
60197cfb | 7226 | const struct file_operations btf_fops = { |
3481e64b QM |
7227 | #ifdef CONFIG_PROC_FS |
7228 | .show_fdinfo = bpf_btf_show_fdinfo, | |
7229 | #endif | |
f56a653c MKL |
7230 | .release = btf_release, |
7231 | }; | |
7232 | ||
78958fca MKL |
7233 | static int __btf_new_fd(struct btf *btf) |
7234 | { | |
7235 | return anon_inode_getfd("btf", &btf_fops, btf, O_RDONLY | O_CLOEXEC); | |
7236 | } | |
7237 | ||
47a71c1f | 7238 | int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size) |
f56a653c MKL |
7239 | { |
7240 | struct btf *btf; | |
78958fca | 7241 | int ret; |
f56a653c | 7242 | |
47a71c1f | 7243 | btf = btf_parse(attr, uattr, uattr_size); |
f56a653c MKL |
7244 | if (IS_ERR(btf)) |
7245 | return PTR_ERR(btf); | |
7246 | ||
78958fca MKL |
7247 | ret = btf_alloc_id(btf); |
7248 | if (ret) { | |
7249 | btf_free(btf); | |
7250 | return ret; | |
7251 | } | |
7252 | ||
7253 | /* | |
7254 | * The BTF ID is published to the userspace. | |
7255 | * All BTF free must go through call_rcu() from | |
7256 | * now on (i.e. free by calling btf_put()). | |
7257 | */ | |
7258 | ||
7259 | ret = __btf_new_fd(btf); | |
7260 | if (ret < 0) | |
f56a653c MKL |
7261 | btf_put(btf); |
7262 | ||
78958fca | 7263 | return ret; |
f56a653c MKL |
7264 | } |
7265 | ||
7266 | struct btf *btf_get_by_fd(int fd) | |
7267 | { | |
7268 | struct btf *btf; | |
7269 | struct fd f; | |
7270 | ||
7271 | f = fdget(fd); | |
7272 | ||
7273 | if (!f.file) | |
7274 | return ERR_PTR(-EBADF); | |
7275 | ||
7276 | if (f.file->f_op != &btf_fops) { | |
7277 | fdput(f); | |
7278 | return ERR_PTR(-EINVAL); | |
7279 | } | |
7280 | ||
7281 | btf = f.file->private_data; | |
78958fca | 7282 | refcount_inc(&btf->refcnt); |
f56a653c MKL |
7283 | fdput(f); |
7284 | ||
7285 | return btf; | |
7286 | } | |
60197cfb MKL |
7287 | |
7288 | int btf_get_info_by_fd(const struct btf *btf, | |
7289 | const union bpf_attr *attr, | |
7290 | union bpf_attr __user *uattr) | |
7291 | { | |
62dab84c | 7292 | struct bpf_btf_info __user *uinfo; |
5c6f2588 | 7293 | struct bpf_btf_info info; |
62dab84c MKL |
7294 | u32 info_copy, btf_copy; |
7295 | void __user *ubtf; | |
53297220 AN |
7296 | char __user *uname; |
7297 | u32 uinfo_len, uname_len, name_len; | |
7298 | int ret = 0; | |
60197cfb | 7299 | |
62dab84c MKL |
7300 | uinfo = u64_to_user_ptr(attr->info.info); |
7301 | uinfo_len = attr->info.info_len; | |
7302 | ||
7303 | info_copy = min_t(u32, uinfo_len, sizeof(info)); | |
5c6f2588 | 7304 | memset(&info, 0, sizeof(info)); |
62dab84c MKL |
7305 | if (copy_from_user(&info, uinfo, info_copy)) |
7306 | return -EFAULT; | |
7307 | ||
7308 | info.id = btf->id; | |
7309 | ubtf = u64_to_user_ptr(info.btf); | |
7310 | btf_copy = min_t(u32, btf->data_size, info.btf_size); | |
7311 | if (copy_to_user(ubtf, btf->data, btf_copy)) | |
7312 | return -EFAULT; | |
7313 | info.btf_size = btf->data_size; | |
7314 | ||
53297220 AN |
7315 | info.kernel_btf = btf->kernel_btf; |
7316 | ||
7317 | uname = u64_to_user_ptr(info.name); | |
7318 | uname_len = info.name_len; | |
7319 | if (!uname ^ !uname_len) | |
7320 | return -EINVAL; | |
7321 | ||
7322 | name_len = strlen(btf->name); | |
7323 | info.name_len = name_len; | |
7324 | ||
7325 | if (uname) { | |
7326 | if (uname_len >= name_len + 1) { | |
7327 | if (copy_to_user(uname, btf->name, name_len + 1)) | |
7328 | return -EFAULT; | |
7329 | } else { | |
7330 | char zero = '\0'; | |
7331 | ||
7332 | if (copy_to_user(uname, btf->name, uname_len - 1)) | |
7333 | return -EFAULT; | |
7334 | if (put_user(zero, uname + uname_len - 1)) | |
7335 | return -EFAULT; | |
7336 | /* let user-space know about too short buffer */ | |
7337 | ret = -ENOSPC; | |
7338 | } | |
7339 | } | |
7340 | ||
62dab84c MKL |
7341 | if (copy_to_user(uinfo, &info, info_copy) || |
7342 | put_user(info_copy, &uattr->info.info_len)) | |
60197cfb MKL |
7343 | return -EFAULT; |
7344 | ||
53297220 | 7345 | return ret; |
60197cfb | 7346 | } |
78958fca MKL |
7347 | |
7348 | int btf_get_fd_by_id(u32 id) | |
7349 | { | |
7350 | struct btf *btf; | |
7351 | int fd; | |
7352 | ||
7353 | rcu_read_lock(); | |
7354 | btf = idr_find(&btf_idr, id); | |
7355 | if (!btf || !refcount_inc_not_zero(&btf->refcnt)) | |
7356 | btf = ERR_PTR(-ENOENT); | |
7357 | rcu_read_unlock(); | |
7358 | ||
7359 | if (IS_ERR(btf)) | |
7360 | return PTR_ERR(btf); | |
7361 | ||
7362 | fd = __btf_new_fd(btf); | |
7363 | if (fd < 0) | |
7364 | btf_put(btf); | |
7365 | ||
7366 | return fd; | |
7367 | } | |
7368 | ||
22dc4a0f | 7369 | u32 btf_obj_id(const struct btf *btf) |
78958fca MKL |
7370 | { |
7371 | return btf->id; | |
7372 | } | |
eae2e83e | 7373 | |
290248a5 AN |
7374 | bool btf_is_kernel(const struct btf *btf) |
7375 | { | |
7376 | return btf->kernel_btf; | |
7377 | } | |
7378 | ||
541c3bad AN |
7379 | bool btf_is_module(const struct btf *btf) |
7380 | { | |
7381 | return btf->kernel_btf && strcmp(btf->name, "vmlinux") != 0; | |
7382 | } | |
7383 | ||
18688de2 KKD |
7384 | enum { |
7385 | BTF_MODULE_F_LIVE = (1 << 0), | |
7386 | }; | |
7387 | ||
36e68442 AN |
7388 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
7389 | struct btf_module { | |
7390 | struct list_head list; | |
7391 | struct module *module; | |
7392 | struct btf *btf; | |
7393 | struct bin_attribute *sysfs_attr; | |
18688de2 | 7394 | int flags; |
36e68442 AN |
7395 | }; |
7396 | ||
7397 | static LIST_HEAD(btf_modules); | |
7398 | static DEFINE_MUTEX(btf_module_mutex); | |
7399 | ||
7400 | static ssize_t | |
7401 | btf_module_read(struct file *file, struct kobject *kobj, | |
7402 | struct bin_attribute *bin_attr, | |
7403 | char *buf, loff_t off, size_t len) | |
7404 | { | |
7405 | const struct btf *btf = bin_attr->private; | |
7406 | ||
7407 | memcpy(buf, btf->data + off, len); | |
7408 | return len; | |
7409 | } | |
7410 | ||
1e89106d AS |
7411 | static void purge_cand_cache(struct btf *btf); |
7412 | ||
36e68442 AN |
7413 | static int btf_module_notify(struct notifier_block *nb, unsigned long op, |
7414 | void *module) | |
7415 | { | |
7416 | struct btf_module *btf_mod, *tmp; | |
7417 | struct module *mod = module; | |
7418 | struct btf *btf; | |
7419 | int err = 0; | |
7420 | ||
7421 | if (mod->btf_data_size == 0 || | |
18688de2 KKD |
7422 | (op != MODULE_STATE_COMING && op != MODULE_STATE_LIVE && |
7423 | op != MODULE_STATE_GOING)) | |
36e68442 AN |
7424 | goto out; |
7425 | ||
7426 | switch (op) { | |
7427 | case MODULE_STATE_COMING: | |
7428 | btf_mod = kzalloc(sizeof(*btf_mod), GFP_KERNEL); | |
7429 | if (!btf_mod) { | |
7430 | err = -ENOMEM; | |
7431 | goto out; | |
7432 | } | |
7433 | btf = btf_parse_module(mod->name, mod->btf_data, mod->btf_data_size); | |
7434 | if (IS_ERR(btf)) { | |
36e68442 | 7435 | kfree(btf_mod); |
9cb61e50 CB |
7436 | if (!IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) { |
7437 | pr_warn("failed to validate module [%s] BTF: %ld\n", | |
7438 | mod->name, PTR_ERR(btf)); | |
5e214f2e | 7439 | err = PTR_ERR(btf); |
9cb61e50 CB |
7440 | } else { |
7441 | pr_warn_once("Kernel module BTF mismatch detected, BTF debug info may be unavailable for some modules\n"); | |
7442 | } | |
36e68442 AN |
7443 | goto out; |
7444 | } | |
7445 | err = btf_alloc_id(btf); | |
7446 | if (err) { | |
7447 | btf_free(btf); | |
7448 | kfree(btf_mod); | |
7449 | goto out; | |
7450 | } | |
7451 | ||
1e89106d | 7452 | purge_cand_cache(NULL); |
36e68442 AN |
7453 | mutex_lock(&btf_module_mutex); |
7454 | btf_mod->module = module; | |
7455 | btf_mod->btf = btf; | |
7456 | list_add(&btf_mod->list, &btf_modules); | |
7457 | mutex_unlock(&btf_module_mutex); | |
7458 | ||
7459 | if (IS_ENABLED(CONFIG_SYSFS)) { | |
7460 | struct bin_attribute *attr; | |
7461 | ||
7462 | attr = kzalloc(sizeof(*attr), GFP_KERNEL); | |
7463 | if (!attr) | |
7464 | goto out; | |
7465 | ||
7466 | sysfs_bin_attr_init(attr); | |
7467 | attr->attr.name = btf->name; | |
7468 | attr->attr.mode = 0444; | |
7469 | attr->size = btf->data_size; | |
7470 | attr->private = btf; | |
7471 | attr->read = btf_module_read; | |
7472 | ||
7473 | err = sysfs_create_bin_file(btf_kobj, attr); | |
7474 | if (err) { | |
7475 | pr_warn("failed to register module [%s] BTF in sysfs: %d\n", | |
7476 | mod->name, err); | |
7477 | kfree(attr); | |
7478 | err = 0; | |
7479 | goto out; | |
7480 | } | |
7481 | ||
7482 | btf_mod->sysfs_attr = attr; | |
7483 | } | |
7484 | ||
18688de2 KKD |
7485 | break; |
7486 | case MODULE_STATE_LIVE: | |
7487 | mutex_lock(&btf_module_mutex); | |
7488 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
7489 | if (btf_mod->module != module) | |
7490 | continue; | |
7491 | ||
7492 | btf_mod->flags |= BTF_MODULE_F_LIVE; | |
7493 | break; | |
7494 | } | |
7495 | mutex_unlock(&btf_module_mutex); | |
36e68442 AN |
7496 | break; |
7497 | case MODULE_STATE_GOING: | |
7498 | mutex_lock(&btf_module_mutex); | |
7499 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
7500 | if (btf_mod->module != module) | |
7501 | continue; | |
7502 | ||
7503 | list_del(&btf_mod->list); | |
7504 | if (btf_mod->sysfs_attr) | |
7505 | sysfs_remove_bin_file(btf_kobj, btf_mod->sysfs_attr); | |
1e89106d | 7506 | purge_cand_cache(btf_mod->btf); |
36e68442 AN |
7507 | btf_put(btf_mod->btf); |
7508 | kfree(btf_mod->sysfs_attr); | |
7509 | kfree(btf_mod); | |
7510 | break; | |
7511 | } | |
7512 | mutex_unlock(&btf_module_mutex); | |
7513 | break; | |
7514 | } | |
7515 | out: | |
7516 | return notifier_from_errno(err); | |
7517 | } | |
7518 | ||
7519 | static struct notifier_block btf_module_nb = { | |
7520 | .notifier_call = btf_module_notify, | |
7521 | }; | |
7522 | ||
7523 | static int __init btf_module_init(void) | |
7524 | { | |
7525 | register_module_notifier(&btf_module_nb); | |
7526 | return 0; | |
7527 | } | |
7528 | ||
7529 | fs_initcall(btf_module_init); | |
7530 | #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */ | |
541c3bad AN |
7531 | |
7532 | struct module *btf_try_get_module(const struct btf *btf) | |
7533 | { | |
7534 | struct module *res = NULL; | |
7535 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES | |
7536 | struct btf_module *btf_mod, *tmp; | |
7537 | ||
7538 | mutex_lock(&btf_module_mutex); | |
7539 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
7540 | if (btf_mod->btf != btf) | |
7541 | continue; | |
7542 | ||
18688de2 KKD |
7543 | /* We must only consider module whose __init routine has |
7544 | * finished, hence we must check for BTF_MODULE_F_LIVE flag, | |
7545 | * which is set from the notifier callback for | |
7546 | * MODULE_STATE_LIVE. | |
7547 | */ | |
7548 | if ((btf_mod->flags & BTF_MODULE_F_LIVE) && try_module_get(btf_mod->module)) | |
541c3bad AN |
7549 | res = btf_mod->module; |
7550 | ||
7551 | break; | |
7552 | } | |
7553 | mutex_unlock(&btf_module_mutex); | |
7554 | #endif | |
7555 | ||
7556 | return res; | |
7557 | } | |
3d78417b | 7558 | |
9492450f KKD |
7559 | /* Returns struct btf corresponding to the struct module. |
7560 | * This function can return NULL or ERR_PTR. | |
dee872e1 KKD |
7561 | */ |
7562 | static struct btf *btf_get_module_btf(const struct module *module) | |
7563 | { | |
dee872e1 KKD |
7564 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
7565 | struct btf_module *btf_mod, *tmp; | |
7566 | #endif | |
9492450f KKD |
7567 | struct btf *btf = NULL; |
7568 | ||
7569 | if (!module) { | |
7570 | btf = bpf_get_btf_vmlinux(); | |
7ada3787 | 7571 | if (!IS_ERR_OR_NULL(btf)) |
9492450f KKD |
7572 | btf_get(btf); |
7573 | return btf; | |
7574 | } | |
dee872e1 | 7575 | |
dee872e1 KKD |
7576 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
7577 | mutex_lock(&btf_module_mutex); | |
7578 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
7579 | if (btf_mod->module != module) | |
7580 | continue; | |
7581 | ||
7582 | btf_get(btf_mod->btf); | |
7583 | btf = btf_mod->btf; | |
7584 | break; | |
7585 | } | |
7586 | mutex_unlock(&btf_module_mutex); | |
7587 | #endif | |
7588 | ||
7589 | return btf; | |
7590 | } | |
7591 | ||
3d78417b AS |
7592 | BPF_CALL_4(bpf_btf_find_by_name_kind, char *, name, int, name_sz, u32, kind, int, flags) |
7593 | { | |
edc3ec09 KKD |
7594 | struct btf *btf = NULL; |
7595 | int btf_obj_fd = 0; | |
3d78417b AS |
7596 | long ret; |
7597 | ||
7598 | if (flags) | |
7599 | return -EINVAL; | |
7600 | ||
7601 | if (name_sz <= 1 || name[name_sz - 1]) | |
7602 | return -EINVAL; | |
7603 | ||
edc3ec09 KKD |
7604 | ret = bpf_find_btf_id(name, kind, &btf); |
7605 | if (ret > 0 && btf_is_module(btf)) { | |
7606 | btf_obj_fd = __btf_new_fd(btf); | |
7607 | if (btf_obj_fd < 0) { | |
7608 | btf_put(btf); | |
7609 | return btf_obj_fd; | |
3d78417b | 7610 | } |
edc3ec09 | 7611 | return ret | (((u64)btf_obj_fd) << 32); |
3d78417b | 7612 | } |
edc3ec09 KKD |
7613 | if (ret > 0) |
7614 | btf_put(btf); | |
3d78417b AS |
7615 | return ret; |
7616 | } | |
7617 | ||
7618 | const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = { | |
7619 | .func = bpf_btf_find_by_name_kind, | |
7620 | .gpl_only = false, | |
7621 | .ret_type = RET_INTEGER, | |
216e3cd2 | 7622 | .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
3d78417b AS |
7623 | .arg2_type = ARG_CONST_SIZE, |
7624 | .arg3_type = ARG_ANYTHING, | |
7625 | .arg4_type = ARG_ANYTHING, | |
7626 | }; | |
eb529c5b | 7627 | |
d19ddb47 SL |
7628 | BTF_ID_LIST_GLOBAL(btf_tracing_ids, MAX_BTF_TRACING_TYPE) |
7629 | #define BTF_TRACING_TYPE(name, type) BTF_ID(struct, type) | |
7630 | BTF_TRACING_TYPE_xxx | |
7631 | #undef BTF_TRACING_TYPE | |
14f267d9 | 7632 | |
215bf496 AN |
7633 | static int btf_check_iter_kfuncs(struct btf *btf, const char *func_name, |
7634 | const struct btf_type *func, u32 func_flags) | |
7635 | { | |
7636 | u32 flags = func_flags & (KF_ITER_NEW | KF_ITER_NEXT | KF_ITER_DESTROY); | |
7637 | const char *name, *sfx, *iter_name; | |
7638 | const struct btf_param *arg; | |
7639 | const struct btf_type *t; | |
7640 | char exp_name[128]; | |
7641 | u32 nr_args; | |
7642 | ||
7643 | /* exactly one of KF_ITER_{NEW,NEXT,DESTROY} can be set */ | |
7644 | if (!flags || (flags & (flags - 1))) | |
7645 | return -EINVAL; | |
7646 | ||
7647 | /* any BPF iter kfunc should have `struct bpf_iter_<type> *` first arg */ | |
7648 | nr_args = btf_type_vlen(func); | |
7649 | if (nr_args < 1) | |
7650 | return -EINVAL; | |
7651 | ||
7652 | arg = &btf_params(func)[0]; | |
7653 | t = btf_type_skip_modifiers(btf, arg->type, NULL); | |
7654 | if (!t || !btf_type_is_ptr(t)) | |
7655 | return -EINVAL; | |
7656 | t = btf_type_skip_modifiers(btf, t->type, NULL); | |
7657 | if (!t || !__btf_type_is_struct(t)) | |
7658 | return -EINVAL; | |
7659 | ||
7660 | name = btf_name_by_offset(btf, t->name_off); | |
7661 | if (!name || strncmp(name, ITER_PREFIX, sizeof(ITER_PREFIX) - 1)) | |
7662 | return -EINVAL; | |
7663 | ||
7664 | /* sizeof(struct bpf_iter_<type>) should be a multiple of 8 to | |
7665 | * fit nicely in stack slots | |
7666 | */ | |
7667 | if (t->size == 0 || (t->size % 8)) | |
7668 | return -EINVAL; | |
7669 | ||
7670 | /* validate bpf_iter_<type>_{new,next,destroy}(struct bpf_iter_<type> *) | |
7671 | * naming pattern | |
7672 | */ | |
7673 | iter_name = name + sizeof(ITER_PREFIX) - 1; | |
7674 | if (flags & KF_ITER_NEW) | |
7675 | sfx = "new"; | |
7676 | else if (flags & KF_ITER_NEXT) | |
7677 | sfx = "next"; | |
7678 | else /* (flags & KF_ITER_DESTROY) */ | |
7679 | sfx = "destroy"; | |
7680 | ||
7681 | snprintf(exp_name, sizeof(exp_name), "bpf_iter_%s_%s", iter_name, sfx); | |
7682 | if (strcmp(func_name, exp_name)) | |
7683 | return -EINVAL; | |
7684 | ||
7685 | /* only iter constructor should have extra arguments */ | |
7686 | if (!(flags & KF_ITER_NEW) && nr_args != 1) | |
7687 | return -EINVAL; | |
7688 | ||
7689 | if (flags & KF_ITER_NEXT) { | |
7690 | /* bpf_iter_<type>_next() should return pointer */ | |
7691 | t = btf_type_skip_modifiers(btf, func->type, NULL); | |
7692 | if (!t || !btf_type_is_ptr(t)) | |
7693 | return -EINVAL; | |
7694 | } | |
7695 | ||
7696 | if (flags & KF_ITER_DESTROY) { | |
7697 | /* bpf_iter_<type>_destroy() should return void */ | |
7698 | t = btf_type_by_id(btf, func->type); | |
7699 | if (!t || !btf_type_is_void(t)) | |
7700 | return -EINVAL; | |
7701 | } | |
7702 | ||
7703 | return 0; | |
7704 | } | |
7705 | ||
7706 | static int btf_check_kfunc_protos(struct btf *btf, u32 func_id, u32 func_flags) | |
7707 | { | |
7708 | const struct btf_type *func; | |
7709 | const char *func_name; | |
7710 | int err; | |
7711 | ||
7712 | /* any kfunc should be FUNC -> FUNC_PROTO */ | |
7713 | func = btf_type_by_id(btf, func_id); | |
7714 | if (!func || !btf_type_is_func(func)) | |
7715 | return -EINVAL; | |
7716 | ||
7717 | /* sanity check kfunc name */ | |
7718 | func_name = btf_name_by_offset(btf, func->name_off); | |
7719 | if (!func_name || !func_name[0]) | |
7720 | return -EINVAL; | |
7721 | ||
7722 | func = btf_type_by_id(btf, func->type); | |
7723 | if (!func || !btf_type_is_func_proto(func)) | |
7724 | return -EINVAL; | |
7725 | ||
7726 | if (func_flags & (KF_ITER_NEW | KF_ITER_NEXT | KF_ITER_DESTROY)) { | |
7727 | err = btf_check_iter_kfuncs(btf, func_name, func, func_flags); | |
7728 | if (err) | |
7729 | return err; | |
7730 | } | |
7731 | ||
7732 | return 0; | |
7733 | } | |
7734 | ||
dee872e1 | 7735 | /* Kernel Function (kfunc) BTF ID set registration API */ |
14f267d9 | 7736 | |
a4703e31 | 7737 | static int btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, |
e924e80e | 7738 | const struct btf_kfunc_id_set *kset) |
14f267d9 | 7739 | { |
e924e80e AG |
7740 | struct btf_kfunc_hook_filter *hook_filter; |
7741 | struct btf_id_set8 *add_set = kset->set; | |
a4703e31 | 7742 | bool vmlinux_set = !btf_is_module(btf); |
e924e80e | 7743 | bool add_filter = !!kset->filter; |
dee872e1 | 7744 | struct btf_kfunc_set_tab *tab; |
a4703e31 | 7745 | struct btf_id_set8 *set; |
dee872e1 KKD |
7746 | u32 set_cnt; |
7747 | int ret; | |
7748 | ||
a4703e31 | 7749 | if (hook >= BTF_KFUNC_HOOK_MAX) { |
dee872e1 KKD |
7750 | ret = -EINVAL; |
7751 | goto end; | |
7752 | } | |
7753 | ||
7754 | if (!add_set->cnt) | |
7755 | return 0; | |
7756 | ||
7757 | tab = btf->kfunc_set_tab; | |
e924e80e AG |
7758 | |
7759 | if (tab && add_filter) { | |
7760 | u32 i; | |
7761 | ||
7762 | hook_filter = &tab->hook_filters[hook]; | |
7763 | for (i = 0; i < hook_filter->nr_filters; i++) { | |
7764 | if (hook_filter->filters[i] == kset->filter) { | |
7765 | add_filter = false; | |
7766 | break; | |
7767 | } | |
7768 | } | |
7769 | ||
7770 | if (add_filter && hook_filter->nr_filters == BTF_KFUNC_FILTER_MAX_CNT) { | |
7771 | ret = -E2BIG; | |
7772 | goto end; | |
7773 | } | |
7774 | } | |
7775 | ||
dee872e1 KKD |
7776 | if (!tab) { |
7777 | tab = kzalloc(sizeof(*tab), GFP_KERNEL | __GFP_NOWARN); | |
7778 | if (!tab) | |
7779 | return -ENOMEM; | |
7780 | btf->kfunc_set_tab = tab; | |
7781 | } | |
7782 | ||
a4703e31 | 7783 | set = tab->sets[hook]; |
dee872e1 KKD |
7784 | /* Warn when register_btf_kfunc_id_set is called twice for the same hook |
7785 | * for module sets. | |
7786 | */ | |
7787 | if (WARN_ON_ONCE(set && !vmlinux_set)) { | |
7788 | ret = -EINVAL; | |
7789 | goto end; | |
7790 | } | |
7791 | ||
7792 | /* We don't need to allocate, concatenate, and sort module sets, because | |
7793 | * only one is allowed per hook. Hence, we can directly assign the | |
7794 | * pointer and return. | |
7795 | */ | |
7796 | if (!vmlinux_set) { | |
a4703e31 | 7797 | tab->sets[hook] = add_set; |
e924e80e | 7798 | goto do_add_filter; |
dee872e1 KKD |
7799 | } |
7800 | ||
7801 | /* In case of vmlinux sets, there may be more than one set being | |
7802 | * registered per hook. To create a unified set, we allocate a new set | |
7803 | * and concatenate all individual sets being registered. While each set | |
7804 | * is individually sorted, they may become unsorted when concatenated, | |
7805 | * hence re-sorting the final set again is required to make binary | |
a4703e31 | 7806 | * searching the set using btf_id_set8_contains function work. |
dee872e1 KKD |
7807 | */ |
7808 | set_cnt = set ? set->cnt : 0; | |
7809 | ||
7810 | if (set_cnt > U32_MAX - add_set->cnt) { | |
7811 | ret = -EOVERFLOW; | |
7812 | goto end; | |
7813 | } | |
7814 | ||
7815 | if (set_cnt + add_set->cnt > BTF_KFUNC_SET_MAX_CNT) { | |
7816 | ret = -E2BIG; | |
7817 | goto end; | |
7818 | } | |
7819 | ||
7820 | /* Grow set */ | |
a4703e31 KKD |
7821 | set = krealloc(tab->sets[hook], |
7822 | offsetof(struct btf_id_set8, pairs[set_cnt + add_set->cnt]), | |
dee872e1 KKD |
7823 | GFP_KERNEL | __GFP_NOWARN); |
7824 | if (!set) { | |
7825 | ret = -ENOMEM; | |
7826 | goto end; | |
7827 | } | |
7828 | ||
7829 | /* For newly allocated set, initialize set->cnt to 0 */ | |
a4703e31 | 7830 | if (!tab->sets[hook]) |
dee872e1 | 7831 | set->cnt = 0; |
a4703e31 | 7832 | tab->sets[hook] = set; |
dee872e1 KKD |
7833 | |
7834 | /* Concatenate the two sets */ | |
a4703e31 | 7835 | memcpy(set->pairs + set->cnt, add_set->pairs, add_set->cnt * sizeof(set->pairs[0])); |
dee872e1 KKD |
7836 | set->cnt += add_set->cnt; |
7837 | ||
a4703e31 | 7838 | sort(set->pairs, set->cnt, sizeof(set->pairs[0]), btf_id_cmp_func, NULL); |
dee872e1 | 7839 | |
e924e80e AG |
7840 | do_add_filter: |
7841 | if (add_filter) { | |
7842 | hook_filter = &tab->hook_filters[hook]; | |
7843 | hook_filter->filters[hook_filter->nr_filters++] = kset->filter; | |
7844 | } | |
dee872e1 KKD |
7845 | return 0; |
7846 | end: | |
7847 | btf_free_kfunc_set_tab(btf); | |
7848 | return ret; | |
14f267d9 | 7849 | } |
14f267d9 | 7850 | |
a4703e31 | 7851 | static u32 *__btf_kfunc_id_set_contains(const struct btf *btf, |
dee872e1 | 7852 | enum btf_kfunc_hook hook, |
e924e80e AG |
7853 | u32 kfunc_btf_id, |
7854 | const struct bpf_prog *prog) | |
14f267d9 | 7855 | { |
e924e80e | 7856 | struct btf_kfunc_hook_filter *hook_filter; |
a4703e31 | 7857 | struct btf_id_set8 *set; |
e924e80e | 7858 | u32 *id, i; |
14f267d9 | 7859 | |
a4703e31 KKD |
7860 | if (hook >= BTF_KFUNC_HOOK_MAX) |
7861 | return NULL; | |
dee872e1 | 7862 | if (!btf->kfunc_set_tab) |
a4703e31 | 7863 | return NULL; |
e924e80e AG |
7864 | hook_filter = &btf->kfunc_set_tab->hook_filters[hook]; |
7865 | for (i = 0; i < hook_filter->nr_filters; i++) { | |
7866 | if (hook_filter->filters[i](prog, kfunc_btf_id)) | |
7867 | return NULL; | |
7868 | } | |
a4703e31 | 7869 | set = btf->kfunc_set_tab->sets[hook]; |
dee872e1 | 7870 | if (!set) |
a4703e31 KKD |
7871 | return NULL; |
7872 | id = btf_id_set8_contains(set, kfunc_btf_id); | |
7873 | if (!id) | |
7874 | return NULL; | |
7875 | /* The flags for BTF ID are located next to it */ | |
7876 | return id + 1; | |
dee872e1 KKD |
7877 | } |
7878 | ||
7879 | static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type) | |
7880 | { | |
7881 | switch (prog_type) { | |
cfe14564 YS |
7882 | case BPF_PROG_TYPE_UNSPEC: |
7883 | return BTF_KFUNC_HOOK_COMMON; | |
dee872e1 KKD |
7884 | case BPF_PROG_TYPE_XDP: |
7885 | return BTF_KFUNC_HOOK_XDP; | |
7886 | case BPF_PROG_TYPE_SCHED_CLS: | |
7887 | return BTF_KFUNC_HOOK_TC; | |
7888 | case BPF_PROG_TYPE_STRUCT_OPS: | |
7889 | return BTF_KFUNC_HOOK_STRUCT_OPS; | |
97949767 | 7890 | case BPF_PROG_TYPE_TRACING: |
d15bf150 | 7891 | case BPF_PROG_TYPE_LSM: |
97949767 BT |
7892 | return BTF_KFUNC_HOOK_TRACING; |
7893 | case BPF_PROG_TYPE_SYSCALL: | |
7894 | return BTF_KFUNC_HOOK_SYSCALL; | |
b5964b96 | 7895 | case BPF_PROG_TYPE_CGROUP_SKB: |
53e380d2 | 7896 | case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: |
b5964b96 JK |
7897 | return BTF_KFUNC_HOOK_CGROUP_SKB; |
7898 | case BPF_PROG_TYPE_SCHED_ACT: | |
7899 | return BTF_KFUNC_HOOK_SCHED_ACT; | |
7900 | case BPF_PROG_TYPE_SK_SKB: | |
7901 | return BTF_KFUNC_HOOK_SK_SKB; | |
7902 | case BPF_PROG_TYPE_SOCKET_FILTER: | |
7903 | return BTF_KFUNC_HOOK_SOCKET_FILTER; | |
7904 | case BPF_PROG_TYPE_LWT_OUT: | |
7905 | case BPF_PROG_TYPE_LWT_IN: | |
7906 | case BPF_PROG_TYPE_LWT_XMIT: | |
7907 | case BPF_PROG_TYPE_LWT_SEG6LOCAL: | |
7908 | return BTF_KFUNC_HOOK_LWT; | |
fd9c663b FW |
7909 | case BPF_PROG_TYPE_NETFILTER: |
7910 | return BTF_KFUNC_HOOK_NETFILTER; | |
dee872e1 KKD |
7911 | default: |
7912 | return BTF_KFUNC_HOOK_MAX; | |
14f267d9 | 7913 | } |
14f267d9 KKD |
7914 | } |
7915 | ||
dee872e1 KKD |
7916 | /* Caution: |
7917 | * Reference to the module (obtained using btf_try_get_module) corresponding to | |
7918 | * the struct btf *MUST* be held when calling this function from verifier | |
7919 | * context. This is usually true as we stash references in prog's kfunc_btf_tab; | |
7920 | * keeping the reference for the duration of the call provides the necessary | |
7921 | * protection for looking up a well-formed btf->kfunc_set_tab. | |
7922 | */ | |
a4703e31 | 7923 | u32 *btf_kfunc_id_set_contains(const struct btf *btf, |
e924e80e AG |
7924 | u32 kfunc_btf_id, |
7925 | const struct bpf_prog *prog) | |
dee872e1 | 7926 | { |
e924e80e | 7927 | enum bpf_prog_type prog_type = resolve_prog_type(prog); |
dee872e1 | 7928 | enum btf_kfunc_hook hook; |
cfe14564 YS |
7929 | u32 *kfunc_flags; |
7930 | ||
e924e80e | 7931 | kfunc_flags = __btf_kfunc_id_set_contains(btf, BTF_KFUNC_HOOK_COMMON, kfunc_btf_id, prog); |
cfe14564 YS |
7932 | if (kfunc_flags) |
7933 | return kfunc_flags; | |
0e32dfc8 | 7934 | |
dee872e1 | 7935 | hook = bpf_prog_type_to_kfunc_hook(prog_type); |
e924e80e | 7936 | return __btf_kfunc_id_set_contains(btf, hook, kfunc_btf_id, prog); |
dee872e1 | 7937 | } |
d9847eb8 | 7938 | |
e924e80e AG |
7939 | u32 *btf_kfunc_is_modify_return(const struct btf *btf, u32 kfunc_btf_id, |
7940 | const struct bpf_prog *prog) | |
5b481aca | 7941 | { |
e924e80e | 7942 | return __btf_kfunc_id_set_contains(btf, BTF_KFUNC_HOOK_FMODRET, kfunc_btf_id, prog); |
5b481aca BT |
7943 | } |
7944 | ||
7945 | static int __register_btf_kfunc_id_set(enum btf_kfunc_hook hook, | |
7946 | const struct btf_kfunc_id_set *kset) | |
dee872e1 | 7947 | { |
dee872e1 | 7948 | struct btf *btf; |
215bf496 | 7949 | int ret, i; |
dee872e1 KKD |
7950 | |
7951 | btf = btf_get_module_btf(kset->owner); | |
c446fdac SF |
7952 | if (!btf) { |
7953 | if (!kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) { | |
7954 | pr_err("missing vmlinux BTF, cannot register kfuncs\n"); | |
7955 | return -ENOENT; | |
7956 | } | |
3de4d22c SP |
7957 | if (kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) |
7958 | pr_warn("missing module BTF, cannot register kfuncs\n"); | |
c446fdac SF |
7959 | return 0; |
7960 | } | |
7961 | if (IS_ERR(btf)) | |
7962 | return PTR_ERR(btf); | |
dee872e1 | 7963 | |
215bf496 AN |
7964 | for (i = 0; i < kset->set->cnt; i++) { |
7965 | ret = btf_check_kfunc_protos(btf, kset->set->pairs[i].id, | |
7966 | kset->set->pairs[i].flags); | |
7967 | if (ret) | |
7968 | goto err_out; | |
7969 | } | |
7970 | ||
e924e80e AG |
7971 | ret = btf_populate_kfunc_set(btf, hook, kset); |
7972 | ||
215bf496 | 7973 | err_out: |
9492450f | 7974 | btf_put(btf); |
dee872e1 KKD |
7975 | return ret; |
7976 | } | |
5b481aca BT |
7977 | |
7978 | /* This function must be invoked only from initcalls/module init functions */ | |
7979 | int register_btf_kfunc_id_set(enum bpf_prog_type prog_type, | |
7980 | const struct btf_kfunc_id_set *kset) | |
7981 | { | |
7982 | enum btf_kfunc_hook hook; | |
7983 | ||
7984 | hook = bpf_prog_type_to_kfunc_hook(prog_type); | |
7985 | return __register_btf_kfunc_id_set(hook, kset); | |
7986 | } | |
dee872e1 | 7987 | EXPORT_SYMBOL_GPL(register_btf_kfunc_id_set); |
be315829 | 7988 | |
5b481aca BT |
7989 | /* This function must be invoked only from initcalls/module init functions */ |
7990 | int register_btf_fmodret_id_set(const struct btf_kfunc_id_set *kset) | |
7991 | { | |
7992 | return __register_btf_kfunc_id_set(BTF_KFUNC_HOOK_FMODRET, kset); | |
7993 | } | |
7994 | EXPORT_SYMBOL_GPL(register_btf_fmodret_id_set); | |
7995 | ||
5ce937d6 KKD |
7996 | s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id) |
7997 | { | |
7998 | struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab; | |
7999 | struct btf_id_dtor_kfunc *dtor; | |
8000 | ||
8001 | if (!tab) | |
8002 | return -ENOENT; | |
8003 | /* Even though the size of tab->dtors[0] is > sizeof(u32), we only need | |
8004 | * to compare the first u32 with btf_id, so we can reuse btf_id_cmp_func. | |
8005 | */ | |
8006 | BUILD_BUG_ON(offsetof(struct btf_id_dtor_kfunc, btf_id) != 0); | |
8007 | dtor = bsearch(&btf_id, tab->dtors, tab->cnt, sizeof(tab->dtors[0]), btf_id_cmp_func); | |
8008 | if (!dtor) | |
8009 | return -ENOENT; | |
8010 | return dtor->kfunc_btf_id; | |
8011 | } | |
8012 | ||
14a324f6 KKD |
8013 | static int btf_check_dtor_kfuncs(struct btf *btf, const struct btf_id_dtor_kfunc *dtors, u32 cnt) |
8014 | { | |
8015 | const struct btf_type *dtor_func, *dtor_func_proto, *t; | |
8016 | const struct btf_param *args; | |
8017 | s32 dtor_btf_id; | |
8018 | u32 nr_args, i; | |
8019 | ||
8020 | for (i = 0; i < cnt; i++) { | |
8021 | dtor_btf_id = dtors[i].kfunc_btf_id; | |
8022 | ||
8023 | dtor_func = btf_type_by_id(btf, dtor_btf_id); | |
8024 | if (!dtor_func || !btf_type_is_func(dtor_func)) | |
8025 | return -EINVAL; | |
8026 | ||
8027 | dtor_func_proto = btf_type_by_id(btf, dtor_func->type); | |
8028 | if (!dtor_func_proto || !btf_type_is_func_proto(dtor_func_proto)) | |
8029 | return -EINVAL; | |
8030 | ||
8031 | /* Make sure the prototype of the destructor kfunc is 'void func(type *)' */ | |
8032 | t = btf_type_by_id(btf, dtor_func_proto->type); | |
8033 | if (!t || !btf_type_is_void(t)) | |
8034 | return -EINVAL; | |
8035 | ||
8036 | nr_args = btf_type_vlen(dtor_func_proto); | |
8037 | if (nr_args != 1) | |
8038 | return -EINVAL; | |
8039 | args = btf_params(dtor_func_proto); | |
8040 | t = btf_type_by_id(btf, args[0].type); | |
8041 | /* Allow any pointer type, as width on targets Linux supports | |
8042 | * will be same for all pointer types (i.e. sizeof(void *)) | |
8043 | */ | |
8044 | if (!t || !btf_type_is_ptr(t)) | |
8045 | return -EINVAL; | |
8046 | } | |
8047 | return 0; | |
8048 | } | |
8049 | ||
5ce937d6 KKD |
8050 | /* This function must be invoked only from initcalls/module init functions */ |
8051 | int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_cnt, | |
8052 | struct module *owner) | |
8053 | { | |
8054 | struct btf_id_dtor_kfunc_tab *tab; | |
8055 | struct btf *btf; | |
8056 | u32 tab_cnt; | |
8057 | int ret; | |
8058 | ||
8059 | btf = btf_get_module_btf(owner); | |
8060 | if (!btf) { | |
8061 | if (!owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) { | |
8062 | pr_err("missing vmlinux BTF, cannot register dtor kfuncs\n"); | |
8063 | return -ENOENT; | |
8064 | } | |
8065 | if (owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) { | |
8066 | pr_err("missing module BTF, cannot register dtor kfuncs\n"); | |
8067 | return -ENOENT; | |
8068 | } | |
8069 | return 0; | |
8070 | } | |
8071 | if (IS_ERR(btf)) | |
8072 | return PTR_ERR(btf); | |
8073 | ||
8074 | if (add_cnt >= BTF_DTOR_KFUNC_MAX_CNT) { | |
8075 | pr_err("cannot register more than %d kfunc destructors\n", BTF_DTOR_KFUNC_MAX_CNT); | |
8076 | ret = -E2BIG; | |
8077 | goto end; | |
8078 | } | |
8079 | ||
14a324f6 KKD |
8080 | /* Ensure that the prototype of dtor kfuncs being registered is sane */ |
8081 | ret = btf_check_dtor_kfuncs(btf, dtors, add_cnt); | |
8082 | if (ret < 0) | |
8083 | goto end; | |
8084 | ||
5ce937d6 KKD |
8085 | tab = btf->dtor_kfunc_tab; |
8086 | /* Only one call allowed for modules */ | |
8087 | if (WARN_ON_ONCE(tab && btf_is_module(btf))) { | |
8088 | ret = -EINVAL; | |
8089 | goto end; | |
8090 | } | |
8091 | ||
8092 | tab_cnt = tab ? tab->cnt : 0; | |
8093 | if (tab_cnt > U32_MAX - add_cnt) { | |
8094 | ret = -EOVERFLOW; | |
8095 | goto end; | |
8096 | } | |
8097 | if (tab_cnt + add_cnt >= BTF_DTOR_KFUNC_MAX_CNT) { | |
8098 | pr_err("cannot register more than %d kfunc destructors\n", BTF_DTOR_KFUNC_MAX_CNT); | |
8099 | ret = -E2BIG; | |
8100 | goto end; | |
8101 | } | |
8102 | ||
8103 | tab = krealloc(btf->dtor_kfunc_tab, | |
8104 | offsetof(struct btf_id_dtor_kfunc_tab, dtors[tab_cnt + add_cnt]), | |
8105 | GFP_KERNEL | __GFP_NOWARN); | |
8106 | if (!tab) { | |
8107 | ret = -ENOMEM; | |
8108 | goto end; | |
8109 | } | |
8110 | ||
8111 | if (!btf->dtor_kfunc_tab) | |
8112 | tab->cnt = 0; | |
8113 | btf->dtor_kfunc_tab = tab; | |
8114 | ||
8115 | memcpy(tab->dtors + tab->cnt, dtors, add_cnt * sizeof(tab->dtors[0])); | |
8116 | tab->cnt += add_cnt; | |
8117 | ||
8118 | sort(tab->dtors, tab->cnt, sizeof(tab->dtors[0]), btf_id_cmp_func, NULL); | |
8119 | ||
5ce937d6 | 8120 | end: |
74bc3a5a JO |
8121 | if (ret) |
8122 | btf_free_dtor_kfunc_tab(btf); | |
5ce937d6 KKD |
8123 | btf_put(btf); |
8124 | return ret; | |
8125 | } | |
8126 | EXPORT_SYMBOL_GPL(register_btf_id_dtor_kfuncs); | |
8127 | ||
e70e13e7 MC |
8128 | #define MAX_TYPES_ARE_COMPAT_DEPTH 2 |
8129 | ||
e70e13e7 MC |
8130 | /* Check local and target types for compatibility. This check is used for |
8131 | * type-based CO-RE relocations and follow slightly different rules than | |
8132 | * field-based relocations. This function assumes that root types were already | |
8133 | * checked for name match. Beyond that initial root-level name check, names | |
8134 | * are completely ignored. Compatibility rules are as follows: | |
6089fb32 | 8135 | * - any two STRUCTs/UNIONs/FWDs/ENUMs/INTs/ENUM64s are considered compatible, but |
e70e13e7 MC |
8136 | * kind should match for local and target types (i.e., STRUCT is not |
8137 | * compatible with UNION); | |
6089fb32 | 8138 | * - for ENUMs/ENUM64s, the size is ignored; |
e70e13e7 MC |
8139 | * - for INT, size and signedness are ignored; |
8140 | * - for ARRAY, dimensionality is ignored, element types are checked for | |
8141 | * compatibility recursively; | |
8142 | * - CONST/VOLATILE/RESTRICT modifiers are ignored; | |
8143 | * - TYPEDEFs/PTRs are compatible if types they pointing to are compatible; | |
8144 | * - FUNC_PROTOs are compatible if they have compatible signature: same | |
8145 | * number of input args and compatible return and argument types. | |
8146 | * These rules are not set in stone and probably will be adjusted as we get | |
8147 | * more experience with using BPF CO-RE relocations. | |
8148 | */ | |
29db4bea AS |
8149 | int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, |
8150 | const struct btf *targ_btf, __u32 targ_id) | |
8151 | { | |
fd75733d | 8152 | return __bpf_core_types_are_compat(local_btf, local_id, targ_btf, targ_id, |
e70e13e7 | 8153 | MAX_TYPES_ARE_COMPAT_DEPTH); |
29db4bea AS |
8154 | } |
8155 | ||
ec6209c8 DM |
8156 | #define MAX_TYPES_MATCH_DEPTH 2 |
8157 | ||
8158 | int bpf_core_types_match(const struct btf *local_btf, u32 local_id, | |
8159 | const struct btf *targ_btf, u32 targ_id) | |
8160 | { | |
8161 | return __bpf_core_types_match(local_btf, local_id, targ_btf, targ_id, false, | |
8162 | MAX_TYPES_MATCH_DEPTH); | |
8163 | } | |
8164 | ||
29db4bea AS |
8165 | static bool bpf_core_is_flavor_sep(const char *s) |
8166 | { | |
8167 | /* check X___Y name pattern, where X and Y are not underscores */ | |
8168 | return s[0] != '_' && /* X */ | |
8169 | s[1] == '_' && s[2] == '_' && s[3] == '_' && /* ___ */ | |
8170 | s[4] != '_'; /* Y */ | |
8171 | } | |
8172 | ||
8173 | size_t bpf_core_essential_name_len(const char *name) | |
8174 | { | |
8175 | size_t n = strlen(name); | |
8176 | int i; | |
8177 | ||
8178 | for (i = n - 5; i >= 0; i--) { | |
8179 | if (bpf_core_is_flavor_sep(name + i)) | |
8180 | return i + 1; | |
8181 | } | |
8182 | return n; | |
8183 | } | |
fbd94c7a | 8184 | |
1e89106d AS |
8185 | struct bpf_cand_cache { |
8186 | const char *name; | |
8187 | u32 name_len; | |
8188 | u16 kind; | |
8189 | u16 cnt; | |
8190 | struct { | |
8191 | const struct btf *btf; | |
8192 | u32 id; | |
8193 | } cands[]; | |
8194 | }; | |
8195 | ||
8196 | static void bpf_free_cands(struct bpf_cand_cache *cands) | |
8197 | { | |
8198 | if (!cands->cnt) | |
8199 | /* empty candidate array was allocated on stack */ | |
8200 | return; | |
8201 | kfree(cands); | |
8202 | } | |
8203 | ||
8204 | static void bpf_free_cands_from_cache(struct bpf_cand_cache *cands) | |
8205 | { | |
8206 | kfree(cands->name); | |
8207 | kfree(cands); | |
8208 | } | |
8209 | ||
8210 | #define VMLINUX_CAND_CACHE_SIZE 31 | |
8211 | static struct bpf_cand_cache *vmlinux_cand_cache[VMLINUX_CAND_CACHE_SIZE]; | |
8212 | ||
8213 | #define MODULE_CAND_CACHE_SIZE 31 | |
8214 | static struct bpf_cand_cache *module_cand_cache[MODULE_CAND_CACHE_SIZE]; | |
8215 | ||
8216 | static DEFINE_MUTEX(cand_cache_mutex); | |
8217 | ||
8218 | static void __print_cand_cache(struct bpf_verifier_log *log, | |
8219 | struct bpf_cand_cache **cache, | |
8220 | int cache_size) | |
8221 | { | |
8222 | struct bpf_cand_cache *cc; | |
8223 | int i, j; | |
8224 | ||
8225 | for (i = 0; i < cache_size; i++) { | |
8226 | cc = cache[i]; | |
8227 | if (!cc) | |
8228 | continue; | |
8229 | bpf_log(log, "[%d]%s(", i, cc->name); | |
8230 | for (j = 0; j < cc->cnt; j++) { | |
8231 | bpf_log(log, "%d", cc->cands[j].id); | |
8232 | if (j < cc->cnt - 1) | |
8233 | bpf_log(log, " "); | |
8234 | } | |
8235 | bpf_log(log, "), "); | |
8236 | } | |
8237 | } | |
8238 | ||
8239 | static void print_cand_cache(struct bpf_verifier_log *log) | |
8240 | { | |
8241 | mutex_lock(&cand_cache_mutex); | |
8242 | bpf_log(log, "vmlinux_cand_cache:"); | |
8243 | __print_cand_cache(log, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); | |
8244 | bpf_log(log, "\nmodule_cand_cache:"); | |
8245 | __print_cand_cache(log, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
8246 | bpf_log(log, "\n"); | |
8247 | mutex_unlock(&cand_cache_mutex); | |
8248 | } | |
8249 | ||
8250 | static u32 hash_cands(struct bpf_cand_cache *cands) | |
8251 | { | |
8252 | return jhash(cands->name, cands->name_len, 0); | |
8253 | } | |
8254 | ||
8255 | static struct bpf_cand_cache *check_cand_cache(struct bpf_cand_cache *cands, | |
8256 | struct bpf_cand_cache **cache, | |
8257 | int cache_size) | |
8258 | { | |
8259 | struct bpf_cand_cache *cc = cache[hash_cands(cands) % cache_size]; | |
8260 | ||
8261 | if (cc && cc->name_len == cands->name_len && | |
8262 | !strncmp(cc->name, cands->name, cands->name_len)) | |
8263 | return cc; | |
8264 | return NULL; | |
8265 | } | |
8266 | ||
8267 | static size_t sizeof_cands(int cnt) | |
8268 | { | |
8269 | return offsetof(struct bpf_cand_cache, cands[cnt]); | |
8270 | } | |
8271 | ||
8272 | static struct bpf_cand_cache *populate_cand_cache(struct bpf_cand_cache *cands, | |
8273 | struct bpf_cand_cache **cache, | |
8274 | int cache_size) | |
8275 | { | |
8276 | struct bpf_cand_cache **cc = &cache[hash_cands(cands) % cache_size], *new_cands; | |
8277 | ||
8278 | if (*cc) { | |
8279 | bpf_free_cands_from_cache(*cc); | |
8280 | *cc = NULL; | |
8281 | } | |
4674f210 | 8282 | new_cands = kmemdup(cands, sizeof_cands(cands->cnt), GFP_KERNEL); |
1e89106d AS |
8283 | if (!new_cands) { |
8284 | bpf_free_cands(cands); | |
8285 | return ERR_PTR(-ENOMEM); | |
8286 | } | |
1e89106d AS |
8287 | /* strdup the name, since it will stay in cache. |
8288 | * the cands->name points to strings in prog's BTF and the prog can be unloaded. | |
8289 | */ | |
8290 | new_cands->name = kmemdup_nul(cands->name, cands->name_len, GFP_KERNEL); | |
8291 | bpf_free_cands(cands); | |
8292 | if (!new_cands->name) { | |
8293 | kfree(new_cands); | |
8294 | return ERR_PTR(-ENOMEM); | |
8295 | } | |
8296 | *cc = new_cands; | |
8297 | return new_cands; | |
8298 | } | |
8299 | ||
29f2e5bd | 8300 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
1e89106d AS |
8301 | static void __purge_cand_cache(struct btf *btf, struct bpf_cand_cache **cache, |
8302 | int cache_size) | |
8303 | { | |
8304 | struct bpf_cand_cache *cc; | |
8305 | int i, j; | |
8306 | ||
8307 | for (i = 0; i < cache_size; i++) { | |
8308 | cc = cache[i]; | |
8309 | if (!cc) | |
8310 | continue; | |
8311 | if (!btf) { | |
8312 | /* when new module is loaded purge all of module_cand_cache, | |
8313 | * since new module might have candidates with the name | |
8314 | * that matches cached cands. | |
8315 | */ | |
8316 | bpf_free_cands_from_cache(cc); | |
8317 | cache[i] = NULL; | |
8318 | continue; | |
8319 | } | |
8320 | /* when module is unloaded purge cache entries | |
8321 | * that match module's btf | |
8322 | */ | |
8323 | for (j = 0; j < cc->cnt; j++) | |
8324 | if (cc->cands[j].btf == btf) { | |
8325 | bpf_free_cands_from_cache(cc); | |
8326 | cache[i] = NULL; | |
8327 | break; | |
8328 | } | |
8329 | } | |
8330 | ||
8331 | } | |
8332 | ||
8333 | static void purge_cand_cache(struct btf *btf) | |
8334 | { | |
8335 | mutex_lock(&cand_cache_mutex); | |
8336 | __purge_cand_cache(btf, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
8337 | mutex_unlock(&cand_cache_mutex); | |
8338 | } | |
29f2e5bd | 8339 | #endif |
1e89106d AS |
8340 | |
8341 | static struct bpf_cand_cache * | |
8342 | bpf_core_add_cands(struct bpf_cand_cache *cands, const struct btf *targ_btf, | |
8343 | int targ_start_id) | |
8344 | { | |
8345 | struct bpf_cand_cache *new_cands; | |
8346 | const struct btf_type *t; | |
8347 | const char *targ_name; | |
8348 | size_t targ_essent_len; | |
8349 | int n, i; | |
8350 | ||
8351 | n = btf_nr_types(targ_btf); | |
8352 | for (i = targ_start_id; i < n; i++) { | |
8353 | t = btf_type_by_id(targ_btf, i); | |
8354 | if (btf_kind(t) != cands->kind) | |
8355 | continue; | |
8356 | ||
8357 | targ_name = btf_name_by_offset(targ_btf, t->name_off); | |
8358 | if (!targ_name) | |
8359 | continue; | |
8360 | ||
8361 | /* the resched point is before strncmp to make sure that search | |
8362 | * for non-existing name will have a chance to schedule(). | |
8363 | */ | |
8364 | cond_resched(); | |
8365 | ||
8366 | if (strncmp(cands->name, targ_name, cands->name_len) != 0) | |
8367 | continue; | |
8368 | ||
8369 | targ_essent_len = bpf_core_essential_name_len(targ_name); | |
8370 | if (targ_essent_len != cands->name_len) | |
8371 | continue; | |
8372 | ||
8373 | /* most of the time there is only one candidate for a given kind+name pair */ | |
8374 | new_cands = kmalloc(sizeof_cands(cands->cnt + 1), GFP_KERNEL); | |
8375 | if (!new_cands) { | |
8376 | bpf_free_cands(cands); | |
8377 | return ERR_PTR(-ENOMEM); | |
8378 | } | |
8379 | ||
8380 | memcpy(new_cands, cands, sizeof_cands(cands->cnt)); | |
8381 | bpf_free_cands(cands); | |
8382 | cands = new_cands; | |
8383 | cands->cands[cands->cnt].btf = targ_btf; | |
8384 | cands->cands[cands->cnt].id = i; | |
8385 | cands->cnt++; | |
8386 | } | |
8387 | return cands; | |
8388 | } | |
8389 | ||
8390 | static struct bpf_cand_cache * | |
8391 | bpf_core_find_cands(struct bpf_core_ctx *ctx, u32 local_type_id) | |
8392 | { | |
8393 | struct bpf_cand_cache *cands, *cc, local_cand = {}; | |
8394 | const struct btf *local_btf = ctx->btf; | |
8395 | const struct btf_type *local_type; | |
8396 | const struct btf *main_btf; | |
8397 | size_t local_essent_len; | |
8398 | struct btf *mod_btf; | |
8399 | const char *name; | |
8400 | int id; | |
8401 | ||
8402 | main_btf = bpf_get_btf_vmlinux(); | |
8403 | if (IS_ERR(main_btf)) | |
f18a4997 | 8404 | return ERR_CAST(main_btf); |
7ada3787 KKD |
8405 | if (!main_btf) |
8406 | return ERR_PTR(-EINVAL); | |
1e89106d AS |
8407 | |
8408 | local_type = btf_type_by_id(local_btf, local_type_id); | |
8409 | if (!local_type) | |
8410 | return ERR_PTR(-EINVAL); | |
8411 | ||
8412 | name = btf_name_by_offset(local_btf, local_type->name_off); | |
8413 | if (str_is_empty(name)) | |
8414 | return ERR_PTR(-EINVAL); | |
8415 | local_essent_len = bpf_core_essential_name_len(name); | |
8416 | ||
8417 | cands = &local_cand; | |
8418 | cands->name = name; | |
8419 | cands->kind = btf_kind(local_type); | |
8420 | cands->name_len = local_essent_len; | |
8421 | ||
8422 | cc = check_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); | |
8423 | /* cands is a pointer to stack here */ | |
8424 | if (cc) { | |
8425 | if (cc->cnt) | |
8426 | return cc; | |
8427 | goto check_modules; | |
8428 | } | |
8429 | ||
8430 | /* Attempt to find target candidates in vmlinux BTF first */ | |
8431 | cands = bpf_core_add_cands(cands, main_btf, 1); | |
8432 | if (IS_ERR(cands)) | |
f18a4997 | 8433 | return ERR_CAST(cands); |
1e89106d AS |
8434 | |
8435 | /* cands is a pointer to kmalloced memory here if cands->cnt > 0 */ | |
8436 | ||
8437 | /* populate cache even when cands->cnt == 0 */ | |
8438 | cc = populate_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); | |
8439 | if (IS_ERR(cc)) | |
f18a4997 | 8440 | return ERR_CAST(cc); |
1e89106d AS |
8441 | |
8442 | /* if vmlinux BTF has any candidate, don't go for module BTFs */ | |
8443 | if (cc->cnt) | |
8444 | return cc; | |
8445 | ||
8446 | check_modules: | |
8447 | /* cands is a pointer to stack here and cands->cnt == 0 */ | |
8448 | cc = check_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
8449 | if (cc) | |
8450 | /* if cache has it return it even if cc->cnt == 0 */ | |
8451 | return cc; | |
8452 | ||
8453 | /* If candidate is not found in vmlinux's BTF then search in module's BTFs */ | |
8454 | spin_lock_bh(&btf_idr_lock); | |
8455 | idr_for_each_entry(&btf_idr, mod_btf, id) { | |
8456 | if (!btf_is_module(mod_btf)) | |
8457 | continue; | |
8458 | /* linear search could be slow hence unlock/lock | |
8459 | * the IDR to avoiding holding it for too long | |
8460 | */ | |
8461 | btf_get(mod_btf); | |
8462 | spin_unlock_bh(&btf_idr_lock); | |
8463 | cands = bpf_core_add_cands(cands, mod_btf, btf_nr_types(main_btf)); | |
acf1c3d6 AS |
8464 | btf_put(mod_btf); |
8465 | if (IS_ERR(cands)) | |
f18a4997 | 8466 | return ERR_CAST(cands); |
1e89106d | 8467 | spin_lock_bh(&btf_idr_lock); |
1e89106d AS |
8468 | } |
8469 | spin_unlock_bh(&btf_idr_lock); | |
8470 | /* cands is a pointer to kmalloced memory here if cands->cnt > 0 | |
8471 | * or pointer to stack if cands->cnd == 0. | |
8472 | * Copy it into the cache even when cands->cnt == 0 and | |
8473 | * return the result. | |
8474 | */ | |
8475 | return populate_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
8476 | } | |
8477 | ||
fbd94c7a AS |
8478 | int bpf_core_apply(struct bpf_core_ctx *ctx, const struct bpf_core_relo *relo, |
8479 | int relo_idx, void *insn) | |
8480 | { | |
1e89106d AS |
8481 | bool need_cands = relo->kind != BPF_CORE_TYPE_ID_LOCAL; |
8482 | struct bpf_core_cand_list cands = {}; | |
adb8fa19 | 8483 | struct bpf_core_relo_res targ_res; |
78c1f8d0 | 8484 | struct bpf_core_spec *specs; |
1e89106d AS |
8485 | int err; |
8486 | ||
78c1f8d0 AS |
8487 | /* ~4k of temp memory necessary to convert LLVM spec like "0:1:0:5" |
8488 | * into arrays of btf_ids of struct fields and array indices. | |
8489 | */ | |
8490 | specs = kcalloc(3, sizeof(*specs), GFP_KERNEL); | |
8491 | if (!specs) | |
8492 | return -ENOMEM; | |
8493 | ||
1e89106d AS |
8494 | if (need_cands) { |
8495 | struct bpf_cand_cache *cc; | |
8496 | int i; | |
8497 | ||
8498 | mutex_lock(&cand_cache_mutex); | |
8499 | cc = bpf_core_find_cands(ctx, relo->type_id); | |
8500 | if (IS_ERR(cc)) { | |
8501 | bpf_log(ctx->log, "target candidate search failed for %d\n", | |
8502 | relo->type_id); | |
8503 | err = PTR_ERR(cc); | |
8504 | goto out; | |
8505 | } | |
8506 | if (cc->cnt) { | |
8507 | cands.cands = kcalloc(cc->cnt, sizeof(*cands.cands), GFP_KERNEL); | |
8508 | if (!cands.cands) { | |
8509 | err = -ENOMEM; | |
8510 | goto out; | |
8511 | } | |
8512 | } | |
8513 | for (i = 0; i < cc->cnt; i++) { | |
8514 | bpf_log(ctx->log, | |
8515 | "CO-RE relocating %s %s: found target candidate [%d]\n", | |
8516 | btf_kind_str[cc->kind], cc->name, cc->cands[i].id); | |
8517 | cands.cands[i].btf = cc->cands[i].btf; | |
8518 | cands.cands[i].id = cc->cands[i].id; | |
8519 | } | |
8520 | cands.len = cc->cnt; | |
8521 | /* cand_cache_mutex needs to span the cache lookup and | |
8522 | * copy of btf pointer into bpf_core_cand_list, | |
adb8fa19 | 8523 | * since module can be unloaded while bpf_core_calc_relo_insn |
1e89106d AS |
8524 | * is working with module's btf. |
8525 | */ | |
8526 | } | |
8527 | ||
adb8fa19 MV |
8528 | err = bpf_core_calc_relo_insn((void *)ctx->log, relo, relo_idx, ctx->btf, &cands, specs, |
8529 | &targ_res); | |
8530 | if (err) | |
8531 | goto out; | |
8532 | ||
8533 | err = bpf_core_patch_insn((void *)ctx->log, insn, relo->insn_off / 8, relo, relo_idx, | |
8534 | &targ_res); | |
8535 | ||
1e89106d | 8536 | out: |
78c1f8d0 | 8537 | kfree(specs); |
1e89106d AS |
8538 | if (need_cands) { |
8539 | kfree(cands.cands); | |
8540 | mutex_unlock(&cand_cache_mutex); | |
8541 | if (ctx->log->level & BPF_LOG_LEVEL2) | |
8542 | print_cand_cache(ctx->log); | |
8543 | } | |
8544 | return err; | |
fbd94c7a | 8545 | } |
57539b1c DV |
8546 | |
8547 | bool btf_nested_type_is_trusted(struct bpf_verifier_log *log, | |
8548 | const struct bpf_reg_state *reg, | |
63260df1 | 8549 | const char *field_name, u32 btf_id, const char *suffix) |
57539b1c DV |
8550 | { |
8551 | struct btf *btf = reg->btf; | |
8552 | const struct btf_type *walk_type, *safe_type; | |
8553 | const char *tname; | |
8554 | char safe_tname[64]; | |
8555 | long ret, safe_id; | |
63260df1 | 8556 | const struct btf_member *member; |
57539b1c | 8557 | u32 i; |
57539b1c DV |
8558 | |
8559 | walk_type = btf_type_by_id(btf, reg->btf_id); | |
8560 | if (!walk_type) | |
8561 | return false; | |
8562 | ||
8563 | tname = btf_name_by_offset(btf, walk_type->name_off); | |
8564 | ||
6fcd486b | 8565 | ret = snprintf(safe_tname, sizeof(safe_tname), "%s%s", tname, suffix); |
a8f12572 | 8566 | if (ret >= sizeof(safe_tname)) |
57539b1c DV |
8567 | return false; |
8568 | ||
8569 | safe_id = btf_find_by_name_kind(btf, safe_tname, BTF_INFO_KIND(walk_type->info)); | |
8570 | if (safe_id < 0) | |
8571 | return false; | |
8572 | ||
8573 | safe_type = btf_type_by_id(btf, safe_id); | |
8574 | if (!safe_type) | |
8575 | return false; | |
8576 | ||
57539b1c DV |
8577 | for_each_member(i, safe_type, member) { |
8578 | const char *m_name = __btf_name_by_offset(btf, member->name_off); | |
63260df1 AS |
8579 | const struct btf_type *mtype = btf_type_by_id(btf, member->type); |
8580 | u32 id; | |
8581 | ||
8582 | if (!btf_type_is_ptr(mtype)) | |
8583 | continue; | |
57539b1c | 8584 | |
63260df1 | 8585 | btf_type_skip_modifiers(btf, mtype->type, &id); |
57539b1c | 8586 | /* If we match on both type and name, the field is considered trusted. */ |
63260df1 | 8587 | if (btf_id == id && !strcmp(field_name, m_name)) |
57539b1c DV |
8588 | return true; |
8589 | } | |
8590 | ||
8591 | return false; | |
8592 | } | |
b613d335 DV |
8593 | |
8594 | bool btf_type_ids_nocast_alias(struct bpf_verifier_log *log, | |
8595 | const struct btf *reg_btf, u32 reg_id, | |
8596 | const struct btf *arg_btf, u32 arg_id) | |
8597 | { | |
8598 | const char *reg_name, *arg_name, *search_needle; | |
8599 | const struct btf_type *reg_type, *arg_type; | |
8600 | int reg_len, arg_len, cmp_len; | |
8601 | size_t pattern_len = sizeof(NOCAST_ALIAS_SUFFIX) - sizeof(char); | |
8602 | ||
8603 | reg_type = btf_type_by_id(reg_btf, reg_id); | |
8604 | if (!reg_type) | |
8605 | return false; | |
8606 | ||
8607 | arg_type = btf_type_by_id(arg_btf, arg_id); | |
8608 | if (!arg_type) | |
8609 | return false; | |
8610 | ||
8611 | reg_name = btf_name_by_offset(reg_btf, reg_type->name_off); | |
8612 | arg_name = btf_name_by_offset(arg_btf, arg_type->name_off); | |
8613 | ||
8614 | reg_len = strlen(reg_name); | |
8615 | arg_len = strlen(arg_name); | |
8616 | ||
8617 | /* Exactly one of the two type names may be suffixed with ___init, so | |
8618 | * if the strings are the same size, they can't possibly be no-cast | |
8619 | * aliases of one another. If you have two of the same type names, e.g. | |
8620 | * they're both nf_conn___init, it would be improper to return true | |
8621 | * because they are _not_ no-cast aliases, they are the same type. | |
8622 | */ | |
8623 | if (reg_len == arg_len) | |
8624 | return false; | |
8625 | ||
8626 | /* Either of the two names must be the other name, suffixed with ___init. */ | |
8627 | if ((reg_len != arg_len + pattern_len) && | |
8628 | (arg_len != reg_len + pattern_len)) | |
8629 | return false; | |
8630 | ||
8631 | if (reg_len < arg_len) { | |
8632 | search_needle = strstr(arg_name, NOCAST_ALIAS_SUFFIX); | |
8633 | cmp_len = reg_len; | |
8634 | } else { | |
8635 | search_needle = strstr(reg_name, NOCAST_ALIAS_SUFFIX); | |
8636 | cmp_len = arg_len; | |
8637 | } | |
8638 | ||
8639 | if (!search_needle) | |
8640 | return false; | |
8641 | ||
8642 | /* ___init suffix must come at the end of the name */ | |
8643 | if (*(search_needle + pattern_len) != '\0') | |
8644 | return false; | |
8645 | ||
8646 | return !strncmp(reg_name, arg_name, cmp_len); | |
8647 | } |