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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> |
1e89106d | 32 | #include "../tools/lib/bpf/relo_core.h" |
69b693f0 MKL |
33 | |
34 | /* BTF (BPF Type Format) is the meta data format which describes | |
35 | * the data types of BPF program/map. Hence, it basically focus | |
36 | * on the C programming language which the modern BPF is primary | |
37 | * using. | |
38 | * | |
39 | * ELF Section: | |
40 | * ~~~~~~~~~~~ | |
41 | * The BTF data is stored under the ".BTF" ELF section | |
42 | * | |
43 | * struct btf_type: | |
44 | * ~~~~~~~~~~~~~~~ | |
45 | * Each 'struct btf_type' object describes a C data type. | |
46 | * Depending on the type it is describing, a 'struct btf_type' | |
47 | * object may be followed by more data. F.e. | |
48 | * To describe an array, 'struct btf_type' is followed by | |
49 | * 'struct btf_array'. | |
50 | * | |
51 | * 'struct btf_type' and any extra data following it are | |
52 | * 4 bytes aligned. | |
53 | * | |
54 | * Type section: | |
55 | * ~~~~~~~~~~~~~ | |
56 | * The BTF type section contains a list of 'struct btf_type' objects. | |
57 | * Each one describes a C type. Recall from the above section | |
58 | * that a 'struct btf_type' object could be immediately followed by extra | |
8fb33b60 | 59 | * data in order to describe some particular C types. |
69b693f0 MKL |
60 | * |
61 | * type_id: | |
62 | * ~~~~~~~ | |
63 | * Each btf_type object is identified by a type_id. The type_id | |
64 | * is implicitly implied by the location of the btf_type object in | |
65 | * the BTF type section. The first one has type_id 1. The second | |
66 | * one has type_id 2...etc. Hence, an earlier btf_type has | |
67 | * a smaller type_id. | |
68 | * | |
69 | * A btf_type object may refer to another btf_type object by using | |
70 | * type_id (i.e. the "type" in the "struct btf_type"). | |
71 | * | |
72 | * NOTE that we cannot assume any reference-order. | |
73 | * A btf_type object can refer to an earlier btf_type object | |
74 | * but it can also refer to a later btf_type object. | |
75 | * | |
76 | * For example, to describe "const void *". A btf_type | |
77 | * object describing "const" may refer to another btf_type | |
78 | * object describing "void *". This type-reference is done | |
79 | * by specifying type_id: | |
80 | * | |
81 | * [1] CONST (anon) type_id=2 | |
82 | * [2] PTR (anon) type_id=0 | |
83 | * | |
84 | * The above is the btf_verifier debug log: | |
85 | * - Each line started with "[?]" is a btf_type object | |
86 | * - [?] is the type_id of the btf_type object. | |
87 | * - CONST/PTR is the BTF_KIND_XXX | |
88 | * - "(anon)" is the name of the type. It just | |
89 | * happens that CONST and PTR has no name. | |
90 | * - type_id=XXX is the 'u32 type' in btf_type | |
91 | * | |
92 | * NOTE: "void" has type_id 0 | |
93 | * | |
94 | * String section: | |
95 | * ~~~~~~~~~~~~~~ | |
96 | * The BTF string section contains the names used by the type section. | |
97 | * Each string is referred by an "offset" from the beginning of the | |
98 | * string section. | |
99 | * | |
100 | * Each string is '\0' terminated. | |
101 | * | |
102 | * The first character in the string section must be '\0' | |
103 | * which is used to mean 'anonymous'. Some btf_type may not | |
104 | * have a name. | |
105 | */ | |
106 | ||
107 | /* BTF verification: | |
108 | * | |
109 | * To verify BTF data, two passes are needed. | |
110 | * | |
111 | * Pass #1 | |
112 | * ~~~~~~~ | |
113 | * The first pass is to collect all btf_type objects to | |
114 | * an array: "btf->types". | |
115 | * | |
116 | * Depending on the C type that a btf_type is describing, | |
117 | * a btf_type may be followed by extra data. We don't know | |
118 | * how many btf_type is there, and more importantly we don't | |
119 | * know where each btf_type is located in the type section. | |
120 | * | |
121 | * Without knowing the location of each type_id, most verifications | |
122 | * cannot be done. e.g. an earlier btf_type may refer to a later | |
123 | * btf_type (recall the "const void *" above), so we cannot | |
124 | * check this type-reference in the first pass. | |
125 | * | |
126 | * In the first pass, it still does some verifications (e.g. | |
127 | * checking the name is a valid offset to the string section). | |
eb3f595d MKL |
128 | * |
129 | * Pass #2 | |
130 | * ~~~~~~~ | |
131 | * The main focus is to resolve a btf_type that is referring | |
132 | * to another type. | |
133 | * | |
134 | * We have to ensure the referring type: | |
135 | * 1) does exist in the BTF (i.e. in btf->types[]) | |
136 | * 2) does not cause a loop: | |
137 | * struct A { | |
138 | * struct B b; | |
139 | * }; | |
140 | * | |
141 | * struct B { | |
142 | * struct A a; | |
143 | * }; | |
144 | * | |
145 | * btf_type_needs_resolve() decides if a btf_type needs | |
146 | * to be resolved. | |
147 | * | |
148 | * The needs_resolve type implements the "resolve()" ops which | |
149 | * essentially does a DFS and detects backedge. | |
150 | * | |
151 | * During resolve (or DFS), different C types have different | |
152 | * "RESOLVED" conditions. | |
153 | * | |
154 | * When resolving a BTF_KIND_STRUCT, we need to resolve all its | |
155 | * members because a member is always referring to another | |
156 | * type. A struct's member can be treated as "RESOLVED" if | |
157 | * it is referring to a BTF_KIND_PTR. Otherwise, the | |
158 | * following valid C struct would be rejected: | |
159 | * | |
160 | * struct A { | |
161 | * int m; | |
162 | * struct A *a; | |
163 | * }; | |
164 | * | |
165 | * When resolving a BTF_KIND_PTR, it needs to keep resolving if | |
166 | * it is referring to another BTF_KIND_PTR. Otherwise, we cannot | |
167 | * detect a pointer loop, e.g.: | |
168 | * BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR + | |
169 | * ^ | | |
170 | * +-----------------------------------------+ | |
171 | * | |
69b693f0 MKL |
172 | */ |
173 | ||
b1e8818c | 174 | #define BITS_PER_U128 (sizeof(u64) * BITS_PER_BYTE * 2) |
69b693f0 MKL |
175 | #define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1) |
176 | #define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK) | |
177 | #define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3) | |
178 | #define BITS_ROUNDUP_BYTES(bits) \ | |
179 | (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits)) | |
180 | ||
b1828f0b | 181 | #define BTF_INFO_MASK 0x9f00ffff |
aea2f7b8 MKL |
182 | #define BTF_INT_MASK 0x0fffffff |
183 | #define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE) | |
184 | #define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET) | |
185 | ||
69b693f0 MKL |
186 | /* 16MB for 64k structs and each has 16 members and |
187 | * a few MB spaces for the string section. | |
188 | * The hard limit is S32_MAX. | |
189 | */ | |
190 | #define BTF_MAX_SIZE (16 * 1024 * 1024) | |
69b693f0 | 191 | |
eb3f595d MKL |
192 | #define for_each_member_from(i, from, struct_type, member) \ |
193 | for (i = from, member = btf_type_member(struct_type) + from; \ | |
194 | i < btf_type_vlen(struct_type); \ | |
195 | i++, member++) | |
196 | ||
1dc92851 DB |
197 | #define for_each_vsi_from(i, from, struct_type, member) \ |
198 | for (i = from, member = btf_type_var_secinfo(struct_type) + from; \ | |
199 | i < btf_type_vlen(struct_type); \ | |
200 | i++, member++) | |
201 | ||
1b9ed84e QM |
202 | DEFINE_IDR(btf_idr); |
203 | DEFINE_SPINLOCK(btf_idr_lock); | |
78958fca | 204 | |
dee872e1 | 205 | enum btf_kfunc_hook { |
cfe14564 | 206 | BTF_KFUNC_HOOK_COMMON, |
dee872e1 KKD |
207 | BTF_KFUNC_HOOK_XDP, |
208 | BTF_KFUNC_HOOK_TC, | |
209 | BTF_KFUNC_HOOK_STRUCT_OPS, | |
97949767 BT |
210 | BTF_KFUNC_HOOK_TRACING, |
211 | BTF_KFUNC_HOOK_SYSCALL, | |
5b481aca | 212 | BTF_KFUNC_HOOK_FMODRET, |
b5964b96 JK |
213 | BTF_KFUNC_HOOK_CGROUP_SKB, |
214 | BTF_KFUNC_HOOK_SCHED_ACT, | |
215 | BTF_KFUNC_HOOK_SK_SKB, | |
216 | BTF_KFUNC_HOOK_SOCKET_FILTER, | |
217 | BTF_KFUNC_HOOK_LWT, | |
fd9c663b | 218 | BTF_KFUNC_HOOK_NETFILTER, |
dee872e1 KKD |
219 | BTF_KFUNC_HOOK_MAX, |
220 | }; | |
221 | ||
222 | enum { | |
f9b34818 | 223 | BTF_KFUNC_SET_MAX_CNT = 256, |
5ce937d6 | 224 | BTF_DTOR_KFUNC_MAX_CNT = 256, |
dee872e1 KKD |
225 | }; |
226 | ||
227 | struct btf_kfunc_set_tab { | |
a4703e31 | 228 | struct btf_id_set8 *sets[BTF_KFUNC_HOOK_MAX]; |
dee872e1 KKD |
229 | }; |
230 | ||
5ce937d6 KKD |
231 | struct btf_id_dtor_kfunc_tab { |
232 | u32 cnt; | |
233 | struct btf_id_dtor_kfunc dtors[]; | |
234 | }; | |
235 | ||
69b693f0 | 236 | struct btf { |
f80442a4 | 237 | void *data; |
69b693f0 | 238 | struct btf_type **types; |
eb3f595d MKL |
239 | u32 *resolved_ids; |
240 | u32 *resolved_sizes; | |
69b693f0 MKL |
241 | const char *strings; |
242 | void *nohdr_data; | |
f80442a4 | 243 | struct btf_header hdr; |
951bb646 | 244 | u32 nr_types; /* includes VOID for base BTF */ |
69b693f0 MKL |
245 | u32 types_size; |
246 | u32 data_size; | |
f56a653c | 247 | refcount_t refcnt; |
78958fca MKL |
248 | u32 id; |
249 | struct rcu_head rcu; | |
dee872e1 | 250 | struct btf_kfunc_set_tab *kfunc_set_tab; |
5ce937d6 | 251 | struct btf_id_dtor_kfunc_tab *dtor_kfunc_tab; |
8ffa5cc1 | 252 | struct btf_struct_metas *struct_meta_tab; |
951bb646 AN |
253 | |
254 | /* split BTF support */ | |
255 | struct btf *base_btf; | |
256 | u32 start_id; /* first type ID in this BTF (0 for base BTF) */ | |
257 | u32 start_str_off; /* first string offset (0 for base BTF) */ | |
53297220 AN |
258 | char name[MODULE_NAME_LEN]; |
259 | bool kernel_btf; | |
69b693f0 MKL |
260 | }; |
261 | ||
eb3f595d MKL |
262 | enum verifier_phase { |
263 | CHECK_META, | |
264 | CHECK_TYPE, | |
265 | }; | |
266 | ||
267 | struct resolve_vertex { | |
268 | const struct btf_type *t; | |
269 | u32 type_id; | |
270 | u16 next_member; | |
271 | }; | |
272 | ||
273 | enum visit_state { | |
274 | NOT_VISITED, | |
275 | VISITED, | |
276 | RESOLVED, | |
277 | }; | |
278 | ||
279 | enum resolve_mode { | |
280 | RESOLVE_TBD, /* To Be Determined */ | |
281 | RESOLVE_PTR, /* Resolving for Pointer */ | |
282 | RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union | |
283 | * or array | |
284 | */ | |
285 | }; | |
286 | ||
287 | #define MAX_RESOLVE_DEPTH 32 | |
288 | ||
f80442a4 MKL |
289 | struct btf_sec_info { |
290 | u32 off; | |
291 | u32 len; | |
292 | }; | |
293 | ||
69b693f0 MKL |
294 | struct btf_verifier_env { |
295 | struct btf *btf; | |
eb3f595d MKL |
296 | u8 *visit_states; |
297 | struct resolve_vertex stack[MAX_RESOLVE_DEPTH]; | |
69b693f0 MKL |
298 | struct bpf_verifier_log log; |
299 | u32 log_type_id; | |
eb3f595d MKL |
300 | u32 top_stack; |
301 | enum verifier_phase phase; | |
302 | enum resolve_mode resolve_mode; | |
69b693f0 MKL |
303 | }; |
304 | ||
305 | static const char * const btf_kind_str[NR_BTF_KINDS] = { | |
306 | [BTF_KIND_UNKN] = "UNKNOWN", | |
307 | [BTF_KIND_INT] = "INT", | |
308 | [BTF_KIND_PTR] = "PTR", | |
309 | [BTF_KIND_ARRAY] = "ARRAY", | |
310 | [BTF_KIND_STRUCT] = "STRUCT", | |
311 | [BTF_KIND_UNION] = "UNION", | |
312 | [BTF_KIND_ENUM] = "ENUM", | |
313 | [BTF_KIND_FWD] = "FWD", | |
314 | [BTF_KIND_TYPEDEF] = "TYPEDEF", | |
315 | [BTF_KIND_VOLATILE] = "VOLATILE", | |
316 | [BTF_KIND_CONST] = "CONST", | |
317 | [BTF_KIND_RESTRICT] = "RESTRICT", | |
2667a262 MKL |
318 | [BTF_KIND_FUNC] = "FUNC", |
319 | [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO", | |
1dc92851 DB |
320 | [BTF_KIND_VAR] = "VAR", |
321 | [BTF_KIND_DATASEC] = "DATASEC", | |
b1828f0b | 322 | [BTF_KIND_FLOAT] = "FLOAT", |
223f903e | 323 | [BTF_KIND_DECL_TAG] = "DECL_TAG", |
8c42d2fa | 324 | [BTF_KIND_TYPE_TAG] = "TYPE_TAG", |
6089fb32 | 325 | [BTF_KIND_ENUM64] = "ENUM64", |
69b693f0 MKL |
326 | }; |
327 | ||
e6ac2450 | 328 | const char *btf_type_str(const struct btf_type *t) |
be8704ff AS |
329 | { |
330 | return btf_kind_str[BTF_INFO_KIND(t->info)]; | |
331 | } | |
332 | ||
31d0bc81 AM |
333 | /* Chunk size we use in safe copy of data to be shown. */ |
334 | #define BTF_SHOW_OBJ_SAFE_SIZE 32 | |
335 | ||
336 | /* | |
337 | * This is the maximum size of a base type value (equivalent to a | |
338 | * 128-bit int); if we are at the end of our safe buffer and have | |
339 | * less than 16 bytes space we can't be assured of being able | |
340 | * to copy the next type safely, so in such cases we will initiate | |
341 | * a new copy. | |
342 | */ | |
343 | #define BTF_SHOW_OBJ_BASE_TYPE_SIZE 16 | |
344 | ||
345 | /* Type name size */ | |
346 | #define BTF_SHOW_NAME_SIZE 80 | |
347 | ||
b613d335 DV |
348 | /* |
349 | * The suffix of a type that indicates it cannot alias another type when | |
350 | * comparing BTF IDs for kfunc invocations. | |
351 | */ | |
352 | #define NOCAST_ALIAS_SUFFIX "___init" | |
353 | ||
31d0bc81 AM |
354 | /* |
355 | * Common data to all BTF show operations. Private show functions can add | |
356 | * their own data to a structure containing a struct btf_show and consult it | |
357 | * in the show callback. See btf_type_show() below. | |
358 | * | |
359 | * One challenge with showing nested data is we want to skip 0-valued | |
360 | * data, but in order to figure out whether a nested object is all zeros | |
361 | * we need to walk through it. As a result, we need to make two passes | |
362 | * when handling structs, unions and arrays; the first path simply looks | |
363 | * for nonzero data, while the second actually does the display. The first | |
364 | * pass is signalled by show->state.depth_check being set, and if we | |
365 | * encounter a non-zero value we set show->state.depth_to_show to | |
366 | * the depth at which we encountered it. When we have completed the | |
367 | * first pass, we will know if anything needs to be displayed if | |
368 | * depth_to_show > depth. See btf_[struct,array]_show() for the | |
369 | * implementation of this. | |
370 | * | |
371 | * Another problem is we want to ensure the data for display is safe to | |
372 | * access. To support this, the anonymous "struct {} obj" tracks the data | |
373 | * object and our safe copy of it. We copy portions of the data needed | |
374 | * to the object "copy" buffer, but because its size is limited to | |
375 | * BTF_SHOW_OBJ_COPY_LEN bytes, multiple copies may be required as we | |
376 | * traverse larger objects for display. | |
377 | * | |
378 | * The various data type show functions all start with a call to | |
379 | * btf_show_start_type() which returns a pointer to the safe copy | |
380 | * of the data needed (or if BTF_SHOW_UNSAFE is specified, to the | |
381 | * raw data itself). btf_show_obj_safe() is responsible for | |
382 | * using copy_from_kernel_nofault() to update the safe data if necessary | |
383 | * as we traverse the object's data. skbuff-like semantics are | |
384 | * used: | |
385 | * | |
386 | * - obj.head points to the start of the toplevel object for display | |
387 | * - obj.size is the size of the toplevel object | |
388 | * - obj.data points to the current point in the original data at | |
389 | * which our safe data starts. obj.data will advance as we copy | |
390 | * portions of the data. | |
391 | * | |
392 | * In most cases a single copy will suffice, but larger data structures | |
393 | * such as "struct task_struct" will require many copies. The logic in | |
394 | * btf_show_obj_safe() handles the logic that determines if a new | |
395 | * copy_from_kernel_nofault() is needed. | |
396 | */ | |
397 | struct btf_show { | |
398 | u64 flags; | |
399 | void *target; /* target of show operation (seq file, buffer) */ | |
400 | void (*showfn)(struct btf_show *show, const char *fmt, va_list args); | |
401 | const struct btf *btf; | |
402 | /* below are used during iteration */ | |
403 | struct { | |
404 | u8 depth; | |
405 | u8 depth_to_show; | |
406 | u8 depth_check; | |
407 | u8 array_member:1, | |
408 | array_terminated:1; | |
409 | u16 array_encoding; | |
410 | u32 type_id; | |
411 | int status; /* non-zero for error */ | |
412 | const struct btf_type *type; | |
413 | const struct btf_member *member; | |
414 | char name[BTF_SHOW_NAME_SIZE]; /* space for member name/type */ | |
415 | } state; | |
416 | struct { | |
417 | u32 size; | |
418 | void *head; | |
419 | void *data; | |
420 | u8 safe[BTF_SHOW_OBJ_SAFE_SIZE]; | |
421 | } obj; | |
422 | }; | |
423 | ||
69b693f0 MKL |
424 | struct btf_kind_operations { |
425 | s32 (*check_meta)(struct btf_verifier_env *env, | |
426 | const struct btf_type *t, | |
427 | u32 meta_left); | |
eb3f595d MKL |
428 | int (*resolve)(struct btf_verifier_env *env, |
429 | const struct resolve_vertex *v); | |
179cde8c MKL |
430 | int (*check_member)(struct btf_verifier_env *env, |
431 | const struct btf_type *struct_type, | |
432 | const struct btf_member *member, | |
433 | const struct btf_type *member_type); | |
9d5f9f70 YS |
434 | int (*check_kflag_member)(struct btf_verifier_env *env, |
435 | const struct btf_type *struct_type, | |
436 | const struct btf_member *member, | |
437 | const struct btf_type *member_type); | |
69b693f0 MKL |
438 | void (*log_details)(struct btf_verifier_env *env, |
439 | const struct btf_type *t); | |
31d0bc81 | 440 | void (*show)(const struct btf *btf, const struct btf_type *t, |
b00b8dae | 441 | u32 type_id, void *data, u8 bits_offsets, |
31d0bc81 | 442 | struct btf_show *show); |
69b693f0 MKL |
443 | }; |
444 | ||
445 | static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS]; | |
446 | static struct btf_type btf_void; | |
447 | ||
2667a262 MKL |
448 | static int btf_resolve(struct btf_verifier_env *env, |
449 | const struct btf_type *t, u32 type_id); | |
450 | ||
d7e7b42f YS |
451 | static int btf_func_check(struct btf_verifier_env *env, |
452 | const struct btf_type *t); | |
453 | ||
eb3f595d MKL |
454 | static bool btf_type_is_modifier(const struct btf_type *t) |
455 | { | |
456 | /* Some of them is not strictly a C modifier | |
457 | * but they are grouped into the same bucket | |
458 | * for BTF concern: | |
459 | * A type (t) that refers to another | |
460 | * type through t->type AND its size cannot | |
461 | * be determined without following the t->type. | |
462 | * | |
463 | * ptr does not fall into this bucket | |
464 | * because its size is always sizeof(void *). | |
465 | */ | |
466 | switch (BTF_INFO_KIND(t->info)) { | |
467 | case BTF_KIND_TYPEDEF: | |
468 | case BTF_KIND_VOLATILE: | |
469 | case BTF_KIND_CONST: | |
470 | case BTF_KIND_RESTRICT: | |
8c42d2fa | 471 | case BTF_KIND_TYPE_TAG: |
eb3f595d MKL |
472 | return true; |
473 | } | |
474 | ||
475 | return false; | |
476 | } | |
477 | ||
2824ecb7 | 478 | bool btf_type_is_void(const struct btf_type *t) |
eb3f595d | 479 | { |
b47a0bd2 MKL |
480 | return t == &btf_void; |
481 | } | |
482 | ||
483 | static bool btf_type_is_fwd(const struct btf_type *t) | |
484 | { | |
485 | return BTF_INFO_KIND(t->info) == BTF_KIND_FWD; | |
486 | } | |
487 | ||
488 | static bool btf_type_nosize(const struct btf_type *t) | |
489 | { | |
2667a262 MKL |
490 | return btf_type_is_void(t) || btf_type_is_fwd(t) || |
491 | btf_type_is_func(t) || btf_type_is_func_proto(t); | |
eb3f595d MKL |
492 | } |
493 | ||
b47a0bd2 | 494 | static bool btf_type_nosize_or_null(const struct btf_type *t) |
eb3f595d | 495 | { |
b47a0bd2 | 496 | return !t || btf_type_nosize(t); |
eb3f595d MKL |
497 | } |
498 | ||
1dc92851 DB |
499 | static bool btf_type_is_datasec(const struct btf_type *t) |
500 | { | |
501 | return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC; | |
502 | } | |
503 | ||
223f903e | 504 | static bool btf_type_is_decl_tag(const struct btf_type *t) |
b5ea834d | 505 | { |
223f903e | 506 | return BTF_INFO_KIND(t->info) == BTF_KIND_DECL_TAG; |
b5ea834d YS |
507 | } |
508 | ||
223f903e | 509 | static bool btf_type_is_decl_tag_target(const struct btf_type *t) |
b5ea834d YS |
510 | { |
511 | return btf_type_is_func(t) || btf_type_is_struct(t) || | |
bd16dee6 | 512 | btf_type_is_var(t) || btf_type_is_typedef(t); |
b5ea834d YS |
513 | } |
514 | ||
541c3bad | 515 | u32 btf_nr_types(const struct btf *btf) |
951bb646 AN |
516 | { |
517 | u32 total = 0; | |
518 | ||
519 | while (btf) { | |
520 | total += btf->nr_types; | |
521 | btf = btf->base_btf; | |
522 | } | |
523 | ||
524 | return total; | |
525 | } | |
526 | ||
27ae7997 MKL |
527 | s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind) |
528 | { | |
529 | const struct btf_type *t; | |
530 | const char *tname; | |
951bb646 | 531 | u32 i, total; |
27ae7997 | 532 | |
541c3bad | 533 | total = btf_nr_types(btf); |
951bb646 AN |
534 | for (i = 1; i < total; i++) { |
535 | t = btf_type_by_id(btf, i); | |
27ae7997 MKL |
536 | if (BTF_INFO_KIND(t->info) != kind) |
537 | continue; | |
538 | ||
539 | tname = btf_name_by_offset(btf, t->name_off); | |
540 | if (!strcmp(tname, name)) | |
541 | return i; | |
542 | } | |
543 | ||
544 | return -ENOENT; | |
545 | } | |
546 | ||
edc3ec09 KKD |
547 | static s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p) |
548 | { | |
549 | struct btf *btf; | |
550 | s32 ret; | |
551 | int id; | |
552 | ||
553 | btf = bpf_get_btf_vmlinux(); | |
554 | if (IS_ERR(btf)) | |
555 | return PTR_ERR(btf); | |
7ada3787 KKD |
556 | if (!btf) |
557 | return -EINVAL; | |
edc3ec09 KKD |
558 | |
559 | ret = btf_find_by_name_kind(btf, name, kind); | |
560 | /* ret is never zero, since btf_find_by_name_kind returns | |
561 | * positive btf_id or negative error. | |
562 | */ | |
563 | if (ret > 0) { | |
564 | btf_get(btf); | |
565 | *btf_p = btf; | |
566 | return ret; | |
567 | } | |
568 | ||
569 | /* If name is not found in vmlinux's BTF then search in module's BTFs */ | |
570 | spin_lock_bh(&btf_idr_lock); | |
571 | idr_for_each_entry(&btf_idr, btf, id) { | |
572 | if (!btf_is_module(btf)) | |
573 | continue; | |
574 | /* linear search could be slow hence unlock/lock | |
575 | * the IDR to avoiding holding it for too long | |
576 | */ | |
577 | btf_get(btf); | |
578 | spin_unlock_bh(&btf_idr_lock); | |
579 | ret = btf_find_by_name_kind(btf, name, kind); | |
580 | if (ret > 0) { | |
581 | *btf_p = btf; | |
582 | return ret; | |
583 | } | |
edc3ec09 | 584 | btf_put(btf); |
acf1c3d6 | 585 | spin_lock_bh(&btf_idr_lock); |
edc3ec09 KKD |
586 | } |
587 | spin_unlock_bh(&btf_idr_lock); | |
588 | return ret; | |
589 | } | |
590 | ||
27ae7997 MKL |
591 | const struct btf_type *btf_type_skip_modifiers(const struct btf *btf, |
592 | u32 id, u32 *res_id) | |
593 | { | |
594 | const struct btf_type *t = btf_type_by_id(btf, id); | |
595 | ||
596 | while (btf_type_is_modifier(t)) { | |
597 | id = t->type; | |
598 | t = btf_type_by_id(btf, t->type); | |
599 | } | |
600 | ||
601 | if (res_id) | |
602 | *res_id = id; | |
603 | ||
604 | return t; | |
605 | } | |
606 | ||
607 | const struct btf_type *btf_type_resolve_ptr(const struct btf *btf, | |
608 | u32 id, u32 *res_id) | |
609 | { | |
610 | const struct btf_type *t; | |
611 | ||
612 | t = btf_type_skip_modifiers(btf, id, NULL); | |
613 | if (!btf_type_is_ptr(t)) | |
614 | return NULL; | |
615 | ||
616 | return btf_type_skip_modifiers(btf, t->type, res_id); | |
617 | } | |
618 | ||
619 | const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf, | |
620 | u32 id, u32 *res_id) | |
621 | { | |
622 | const struct btf_type *ptype; | |
623 | ||
624 | ptype = btf_type_resolve_ptr(btf, id, res_id); | |
625 | if (ptype && btf_type_is_func_proto(ptype)) | |
626 | return ptype; | |
627 | ||
628 | return NULL; | |
629 | } | |
630 | ||
1dc92851 DB |
631 | /* Types that act only as a source, not sink or intermediate |
632 | * type when resolving. | |
633 | */ | |
634 | static bool btf_type_is_resolve_source_only(const struct btf_type *t) | |
635 | { | |
636 | return btf_type_is_var(t) || | |
223f903e | 637 | btf_type_is_decl_tag(t) || |
1dc92851 DB |
638 | btf_type_is_datasec(t); |
639 | } | |
640 | ||
eb3f595d MKL |
641 | /* What types need to be resolved? |
642 | * | |
643 | * btf_type_is_modifier() is an obvious one. | |
644 | * | |
645 | * btf_type_is_struct() because its member refers to | |
646 | * another type (through member->type). | |
1dc92851 DB |
647 | * |
648 | * btf_type_is_var() because the variable refers to | |
649 | * another type. btf_type_is_datasec() holds multiple | |
650 | * btf_type_is_var() types that need resolving. | |
651 | * | |
eb3f595d MKL |
652 | * btf_type_is_array() because its element (array->type) |
653 | * refers to another type. Array can be thought of a | |
654 | * special case of struct while array just has the same | |
655 | * member-type repeated by array->nelems of times. | |
656 | */ | |
657 | static bool btf_type_needs_resolve(const struct btf_type *t) | |
658 | { | |
659 | return btf_type_is_modifier(t) || | |
1dc92851 DB |
660 | btf_type_is_ptr(t) || |
661 | btf_type_is_struct(t) || | |
662 | btf_type_is_array(t) || | |
663 | btf_type_is_var(t) || | |
d7e7b42f | 664 | btf_type_is_func(t) || |
223f903e | 665 | btf_type_is_decl_tag(t) || |
1dc92851 | 666 | btf_type_is_datasec(t); |
eb3f595d MKL |
667 | } |
668 | ||
669 | /* t->size can be used */ | |
670 | static bool btf_type_has_size(const struct btf_type *t) | |
671 | { | |
672 | switch (BTF_INFO_KIND(t->info)) { | |
673 | case BTF_KIND_INT: | |
674 | case BTF_KIND_STRUCT: | |
675 | case BTF_KIND_UNION: | |
676 | case BTF_KIND_ENUM: | |
1dc92851 | 677 | case BTF_KIND_DATASEC: |
b1828f0b | 678 | case BTF_KIND_FLOAT: |
6089fb32 | 679 | case BTF_KIND_ENUM64: |
eb3f595d MKL |
680 | return true; |
681 | } | |
682 | ||
683 | return false; | |
684 | } | |
685 | ||
69b693f0 MKL |
686 | static const char *btf_int_encoding_str(u8 encoding) |
687 | { | |
688 | if (encoding == 0) | |
689 | return "(none)"; | |
690 | else if (encoding == BTF_INT_SIGNED) | |
691 | return "SIGNED"; | |
692 | else if (encoding == BTF_INT_CHAR) | |
693 | return "CHAR"; | |
694 | else if (encoding == BTF_INT_BOOL) | |
695 | return "BOOL"; | |
69b693f0 MKL |
696 | else |
697 | return "UNKN"; | |
698 | } | |
699 | ||
69b693f0 MKL |
700 | static u32 btf_type_int(const struct btf_type *t) |
701 | { | |
702 | return *(u32 *)(t + 1); | |
703 | } | |
704 | ||
705 | static const struct btf_array *btf_type_array(const struct btf_type *t) | |
706 | { | |
707 | return (const struct btf_array *)(t + 1); | |
708 | } | |
709 | ||
69b693f0 MKL |
710 | static const struct btf_enum *btf_type_enum(const struct btf_type *t) |
711 | { | |
712 | return (const struct btf_enum *)(t + 1); | |
713 | } | |
714 | ||
1dc92851 DB |
715 | static const struct btf_var *btf_type_var(const struct btf_type *t) |
716 | { | |
717 | return (const struct btf_var *)(t + 1); | |
718 | } | |
719 | ||
223f903e | 720 | static const struct btf_decl_tag *btf_type_decl_tag(const struct btf_type *t) |
b5ea834d | 721 | { |
223f903e | 722 | return (const struct btf_decl_tag *)(t + 1); |
b5ea834d YS |
723 | } |
724 | ||
6089fb32 YS |
725 | static const struct btf_enum64 *btf_type_enum64(const struct btf_type *t) |
726 | { | |
727 | return (const struct btf_enum64 *)(t + 1); | |
728 | } | |
729 | ||
69b693f0 MKL |
730 | static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t) |
731 | { | |
732 | return kind_ops[BTF_INFO_KIND(t->info)]; | |
733 | } | |
734 | ||
583c5318 | 735 | static bool btf_name_offset_valid(const struct btf *btf, u32 offset) |
69b693f0 | 736 | { |
951bb646 AN |
737 | if (!BTF_STR_OFFSET_VALID(offset)) |
738 | return false; | |
739 | ||
740 | while (offset < btf->start_str_off) | |
741 | btf = btf->base_btf; | |
742 | ||
743 | offset -= btf->start_str_off; | |
744 | return offset < btf->hdr.str_len; | |
69b693f0 MKL |
745 | } |
746 | ||
1dc92851 DB |
747 | static bool __btf_name_char_ok(char c, bool first, bool dot_ok) |
748 | { | |
749 | if ((first ? !isalpha(c) : | |
750 | !isalnum(c)) && | |
751 | c != '_' && | |
752 | ((c == '.' && !dot_ok) || | |
753 | c != '.')) | |
754 | return false; | |
755 | return true; | |
756 | } | |
757 | ||
951bb646 AN |
758 | static const char *btf_str_by_offset(const struct btf *btf, u32 offset) |
759 | { | |
760 | while (offset < btf->start_str_off) | |
761 | btf = btf->base_btf; | |
762 | ||
763 | offset -= btf->start_str_off; | |
764 | if (offset < btf->hdr.str_len) | |
765 | return &btf->strings[offset]; | |
766 | ||
767 | return NULL; | |
768 | } | |
769 | ||
1dc92851 | 770 | static bool __btf_name_valid(const struct btf *btf, u32 offset, bool dot_ok) |
2667a262 MKL |
771 | { |
772 | /* offset must be valid */ | |
951bb646 | 773 | const char *src = btf_str_by_offset(btf, offset); |
2667a262 MKL |
774 | const char *src_limit; |
775 | ||
1dc92851 | 776 | if (!__btf_name_char_ok(*src, true, dot_ok)) |
2667a262 MKL |
777 | return false; |
778 | ||
779 | /* set a limit on identifier length */ | |
780 | src_limit = src + KSYM_NAME_LEN; | |
781 | src++; | |
782 | while (*src && src < src_limit) { | |
1dc92851 | 783 | if (!__btf_name_char_ok(*src, false, dot_ok)) |
2667a262 MKL |
784 | return false; |
785 | src++; | |
786 | } | |
787 | ||
788 | return !*src; | |
789 | } | |
790 | ||
1dc92851 DB |
791 | /* Only C-style identifier is permitted. This can be relaxed if |
792 | * necessary. | |
793 | */ | |
794 | static bool btf_name_valid_identifier(const struct btf *btf, u32 offset) | |
795 | { | |
796 | return __btf_name_valid(btf, offset, false); | |
797 | } | |
798 | ||
799 | static bool btf_name_valid_section(const struct btf *btf, u32 offset) | |
800 | { | |
801 | return __btf_name_valid(btf, offset, true); | |
802 | } | |
803 | ||
23127b33 | 804 | static const char *__btf_name_by_offset(const struct btf *btf, u32 offset) |
69b693f0 | 805 | { |
951bb646 AN |
806 | const char *name; |
807 | ||
aea2f7b8 | 808 | if (!offset) |
69b693f0 | 809 | return "(anon)"; |
951bb646 AN |
810 | |
811 | name = btf_str_by_offset(btf, offset); | |
812 | return name ?: "(invalid-name-offset)"; | |
69b693f0 MKL |
813 | } |
814 | ||
23127b33 MKL |
815 | const char *btf_name_by_offset(const struct btf *btf, u32 offset) |
816 | { | |
951bb646 | 817 | return btf_str_by_offset(btf, offset); |
23127b33 MKL |
818 | } |
819 | ||
838e9690 | 820 | const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id) |
eb3f595d | 821 | { |
951bb646 AN |
822 | while (type_id < btf->start_id) |
823 | btf = btf->base_btf; | |
eb3f595d | 824 | |
951bb646 AN |
825 | type_id -= btf->start_id; |
826 | if (type_id >= btf->nr_types) | |
827 | return NULL; | |
eb3f595d MKL |
828 | return btf->types[type_id]; |
829 | } | |
84c6ac41 | 830 | EXPORT_SYMBOL_GPL(btf_type_by_id); |
eb3f595d | 831 | |
4ef5f574 MKL |
832 | /* |
833 | * Regular int is not a bit field and it must be either | |
b1e8818c | 834 | * u8/u16/u32/u64 or __int128. |
4ef5f574 MKL |
835 | */ |
836 | static bool btf_type_int_is_regular(const struct btf_type *t) | |
837 | { | |
36fc3c8c | 838 | u8 nr_bits, nr_bytes; |
4ef5f574 MKL |
839 | u32 int_data; |
840 | ||
841 | int_data = btf_type_int(t); | |
842 | nr_bits = BTF_INT_BITS(int_data); | |
843 | nr_bytes = BITS_ROUNDUP_BYTES(nr_bits); | |
844 | if (BITS_PER_BYTE_MASKED(nr_bits) || | |
845 | BTF_INT_OFFSET(int_data) || | |
846 | (nr_bytes != sizeof(u8) && nr_bytes != sizeof(u16) && | |
b1e8818c YS |
847 | nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64) && |
848 | nr_bytes != (2 * sizeof(u64)))) { | |
4ef5f574 MKL |
849 | return false; |
850 | } | |
851 | ||
852 | return true; | |
853 | } | |
854 | ||
9a1126b6 | 855 | /* |
ffa0c1cf YS |
856 | * Check that given struct member is a regular int with expected |
857 | * offset and size. | |
9a1126b6 | 858 | */ |
ffa0c1cf YS |
859 | bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s, |
860 | const struct btf_member *m, | |
861 | u32 expected_offset, u32 expected_size) | |
9a1126b6 | 862 | { |
ffa0c1cf YS |
863 | const struct btf_type *t; |
864 | u32 id, int_data; | |
865 | u8 nr_bits; | |
9a1126b6 | 866 | |
ffa0c1cf YS |
867 | id = m->type; |
868 | t = btf_type_id_size(btf, &id, NULL); | |
869 | if (!t || !btf_type_is_int(t)) | |
9a1126b6 RG |
870 | return false; |
871 | ||
872 | int_data = btf_type_int(t); | |
873 | nr_bits = BTF_INT_BITS(int_data); | |
ffa0c1cf YS |
874 | if (btf_type_kflag(s)) { |
875 | u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset); | |
876 | u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset); | |
877 | ||
878 | /* if kflag set, int should be a regular int and | |
879 | * bit offset should be at byte boundary. | |
880 | */ | |
881 | return !bitfield_size && | |
882 | BITS_ROUNDUP_BYTES(bit_offset) == expected_offset && | |
883 | BITS_ROUNDUP_BYTES(nr_bits) == expected_size; | |
884 | } | |
885 | ||
886 | if (BTF_INT_OFFSET(int_data) || | |
887 | BITS_PER_BYTE_MASKED(m->offset) || | |
888 | BITS_ROUNDUP_BYTES(m->offset) != expected_offset || | |
889 | BITS_PER_BYTE_MASKED(nr_bits) || | |
890 | BITS_ROUNDUP_BYTES(nr_bits) != expected_size) | |
9a1126b6 RG |
891 | return false; |
892 | ||
893 | return true; | |
894 | } | |
895 | ||
31d0bc81 AM |
896 | /* Similar to btf_type_skip_modifiers() but does not skip typedefs. */ |
897 | static const struct btf_type *btf_type_skip_qualifiers(const struct btf *btf, | |
898 | u32 id) | |
899 | { | |
900 | const struct btf_type *t = btf_type_by_id(btf, id); | |
901 | ||
902 | while (btf_type_is_modifier(t) && | |
903 | BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF) { | |
31d0bc81 AM |
904 | t = btf_type_by_id(btf, t->type); |
905 | } | |
906 | ||
907 | return t; | |
908 | } | |
909 | ||
910 | #define BTF_SHOW_MAX_ITER 10 | |
911 | ||
912 | #define BTF_KIND_BIT(kind) (1ULL << kind) | |
913 | ||
914 | /* | |
915 | * Populate show->state.name with type name information. | |
916 | * Format of type name is | |
917 | * | |
918 | * [.member_name = ] (type_name) | |
919 | */ | |
920 | static const char *btf_show_name(struct btf_show *show) | |
921 | { | |
922 | /* BTF_MAX_ITER array suffixes "[]" */ | |
923 | const char *array_suffixes = "[][][][][][][][][][]"; | |
924 | const char *array_suffix = &array_suffixes[strlen(array_suffixes)]; | |
925 | /* BTF_MAX_ITER pointer suffixes "*" */ | |
926 | const char *ptr_suffixes = "**********"; | |
927 | const char *ptr_suffix = &ptr_suffixes[strlen(ptr_suffixes)]; | |
928 | const char *name = NULL, *prefix = "", *parens = ""; | |
929 | const struct btf_member *m = show->state.member; | |
73b6eae5 | 930 | const struct btf_type *t; |
31d0bc81 AM |
931 | const struct btf_array *array; |
932 | u32 id = show->state.type_id; | |
933 | const char *member = NULL; | |
934 | bool show_member = false; | |
935 | u64 kinds = 0; | |
936 | int i; | |
937 | ||
938 | show->state.name[0] = '\0'; | |
939 | ||
940 | /* | |
941 | * Don't show type name if we're showing an array member; | |
942 | * in that case we show the array type so don't need to repeat | |
943 | * ourselves for each member. | |
944 | */ | |
945 | if (show->state.array_member) | |
946 | return ""; | |
947 | ||
948 | /* Retrieve member name, if any. */ | |
949 | if (m) { | |
950 | member = btf_name_by_offset(show->btf, m->name_off); | |
951 | show_member = strlen(member) > 0; | |
952 | id = m->type; | |
953 | } | |
954 | ||
955 | /* | |
956 | * Start with type_id, as we have resolved the struct btf_type * | |
957 | * via btf_modifier_show() past the parent typedef to the child | |
958 | * struct, int etc it is defined as. In such cases, the type_id | |
959 | * still represents the starting type while the struct btf_type * | |
960 | * in our show->state points at the resolved type of the typedef. | |
961 | */ | |
962 | t = btf_type_by_id(show->btf, id); | |
963 | if (!t) | |
964 | return ""; | |
965 | ||
966 | /* | |
967 | * The goal here is to build up the right number of pointer and | |
968 | * array suffixes while ensuring the type name for a typedef | |
969 | * is represented. Along the way we accumulate a list of | |
970 | * BTF kinds we have encountered, since these will inform later | |
971 | * display; for example, pointer types will not require an | |
972 | * opening "{" for struct, we will just display the pointer value. | |
973 | * | |
974 | * We also want to accumulate the right number of pointer or array | |
975 | * indices in the format string while iterating until we get to | |
976 | * the typedef/pointee/array member target type. | |
977 | * | |
978 | * We start by pointing at the end of pointer and array suffix | |
979 | * strings; as we accumulate pointers and arrays we move the pointer | |
980 | * or array string backwards so it will show the expected number of | |
981 | * '*' or '[]' for the type. BTF_SHOW_MAX_ITER of nesting of pointers | |
982 | * and/or arrays and typedefs are supported as a precaution. | |
983 | * | |
984 | * We also want to get typedef name while proceeding to resolve | |
985 | * type it points to so that we can add parentheses if it is a | |
986 | * "typedef struct" etc. | |
987 | */ | |
988 | for (i = 0; i < BTF_SHOW_MAX_ITER; i++) { | |
989 | ||
990 | switch (BTF_INFO_KIND(t->info)) { | |
991 | case BTF_KIND_TYPEDEF: | |
992 | if (!name) | |
993 | name = btf_name_by_offset(show->btf, | |
994 | t->name_off); | |
995 | kinds |= BTF_KIND_BIT(BTF_KIND_TYPEDEF); | |
996 | id = t->type; | |
997 | break; | |
998 | case BTF_KIND_ARRAY: | |
999 | kinds |= BTF_KIND_BIT(BTF_KIND_ARRAY); | |
1000 | parens = "["; | |
1001 | if (!t) | |
1002 | return ""; | |
1003 | array = btf_type_array(t); | |
1004 | if (array_suffix > array_suffixes) | |
1005 | array_suffix -= 2; | |
1006 | id = array->type; | |
1007 | break; | |
1008 | case BTF_KIND_PTR: | |
1009 | kinds |= BTF_KIND_BIT(BTF_KIND_PTR); | |
1010 | if (ptr_suffix > ptr_suffixes) | |
1011 | ptr_suffix -= 1; | |
1012 | id = t->type; | |
1013 | break; | |
1014 | default: | |
1015 | id = 0; | |
1016 | break; | |
1017 | } | |
1018 | if (!id) | |
1019 | break; | |
1020 | t = btf_type_skip_qualifiers(show->btf, id); | |
1021 | } | |
1022 | /* We may not be able to represent this type; bail to be safe */ | |
1023 | if (i == BTF_SHOW_MAX_ITER) | |
1024 | return ""; | |
1025 | ||
1026 | if (!name) | |
1027 | name = btf_name_by_offset(show->btf, t->name_off); | |
1028 | ||
1029 | switch (BTF_INFO_KIND(t->info)) { | |
1030 | case BTF_KIND_STRUCT: | |
1031 | case BTF_KIND_UNION: | |
1032 | prefix = BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT ? | |
1033 | "struct" : "union"; | |
1034 | /* if it's an array of struct/union, parens is already set */ | |
1035 | if (!(kinds & (BTF_KIND_BIT(BTF_KIND_ARRAY)))) | |
1036 | parens = "{"; | |
1037 | break; | |
1038 | case BTF_KIND_ENUM: | |
6089fb32 | 1039 | case BTF_KIND_ENUM64: |
31d0bc81 AM |
1040 | prefix = "enum"; |
1041 | break; | |
1042 | default: | |
1043 | break; | |
1044 | } | |
1045 | ||
1046 | /* pointer does not require parens */ | |
1047 | if (kinds & BTF_KIND_BIT(BTF_KIND_PTR)) | |
1048 | parens = ""; | |
1049 | /* typedef does not require struct/union/enum prefix */ | |
1050 | if (kinds & BTF_KIND_BIT(BTF_KIND_TYPEDEF)) | |
1051 | prefix = ""; | |
1052 | ||
1053 | if (!name) | |
1054 | name = ""; | |
1055 | ||
1056 | /* Even if we don't want type name info, we want parentheses etc */ | |
1057 | if (show->flags & BTF_SHOW_NONAME) | |
1058 | snprintf(show->state.name, sizeof(show->state.name), "%s", | |
1059 | parens); | |
1060 | else | |
1061 | snprintf(show->state.name, sizeof(show->state.name), | |
1062 | "%s%s%s(%s%s%s%s%s%s)%s", | |
1063 | /* first 3 strings comprise ".member = " */ | |
1064 | show_member ? "." : "", | |
1065 | show_member ? member : "", | |
1066 | show_member ? " = " : "", | |
1067 | /* ...next is our prefix (struct, enum, etc) */ | |
1068 | prefix, | |
1069 | strlen(prefix) > 0 && strlen(name) > 0 ? " " : "", | |
1070 | /* ...this is the type name itself */ | |
1071 | name, | |
1072 | /* ...suffixed by the appropriate '*', '[]' suffixes */ | |
1073 | strlen(ptr_suffix) > 0 ? " " : "", ptr_suffix, | |
1074 | array_suffix, parens); | |
1075 | ||
1076 | return show->state.name; | |
1077 | } | |
1078 | ||
1079 | static const char *__btf_show_indent(struct btf_show *show) | |
1080 | { | |
1081 | const char *indents = " "; | |
1082 | const char *indent = &indents[strlen(indents)]; | |
1083 | ||
1084 | if ((indent - show->state.depth) >= indents) | |
1085 | return indent - show->state.depth; | |
1086 | return indents; | |
1087 | } | |
1088 | ||
1089 | static const char *btf_show_indent(struct btf_show *show) | |
1090 | { | |
1091 | return show->flags & BTF_SHOW_COMPACT ? "" : __btf_show_indent(show); | |
1092 | } | |
1093 | ||
1094 | static const char *btf_show_newline(struct btf_show *show) | |
1095 | { | |
1096 | return show->flags & BTF_SHOW_COMPACT ? "" : "\n"; | |
1097 | } | |
1098 | ||
1099 | static const char *btf_show_delim(struct btf_show *show) | |
1100 | { | |
1101 | if (show->state.depth == 0) | |
1102 | return ""; | |
1103 | ||
1104 | if ((show->flags & BTF_SHOW_COMPACT) && show->state.type && | |
1105 | BTF_INFO_KIND(show->state.type->info) == BTF_KIND_UNION) | |
1106 | return "|"; | |
1107 | ||
1108 | return ","; | |
1109 | } | |
1110 | ||
1111 | __printf(2, 3) static void btf_show(struct btf_show *show, const char *fmt, ...) | |
1112 | { | |
1113 | va_list args; | |
1114 | ||
1115 | if (!show->state.depth_check) { | |
1116 | va_start(args, fmt); | |
1117 | show->showfn(show, fmt, args); | |
1118 | va_end(args); | |
1119 | } | |
1120 | } | |
1121 | ||
1122 | /* Macros are used here as btf_show_type_value[s]() prepends and appends | |
1123 | * format specifiers to the format specifier passed in; these do the work of | |
1124 | * adding indentation, delimiters etc while the caller simply has to specify | |
1125 | * the type value(s) in the format specifier + value(s). | |
1126 | */ | |
1127 | #define btf_show_type_value(show, fmt, value) \ | |
1128 | do { \ | |
a2a5580f BD |
1129 | if ((value) != (__typeof__(value))0 || \ |
1130 | (show->flags & BTF_SHOW_ZERO) || \ | |
31d0bc81 AM |
1131 | show->state.depth == 0) { \ |
1132 | btf_show(show, "%s%s" fmt "%s%s", \ | |
1133 | btf_show_indent(show), \ | |
1134 | btf_show_name(show), \ | |
1135 | value, btf_show_delim(show), \ | |
1136 | btf_show_newline(show)); \ | |
1137 | if (show->state.depth > show->state.depth_to_show) \ | |
1138 | show->state.depth_to_show = show->state.depth; \ | |
1139 | } \ | |
1140 | } while (0) | |
1141 | ||
1142 | #define btf_show_type_values(show, fmt, ...) \ | |
1143 | do { \ | |
1144 | btf_show(show, "%s%s" fmt "%s%s", btf_show_indent(show), \ | |
1145 | btf_show_name(show), \ | |
1146 | __VA_ARGS__, btf_show_delim(show), \ | |
1147 | btf_show_newline(show)); \ | |
1148 | if (show->state.depth > show->state.depth_to_show) \ | |
1149 | show->state.depth_to_show = show->state.depth; \ | |
1150 | } while (0) | |
1151 | ||
1152 | /* How much is left to copy to safe buffer after @data? */ | |
1153 | static int btf_show_obj_size_left(struct btf_show *show, void *data) | |
1154 | { | |
1155 | return show->obj.head + show->obj.size - data; | |
1156 | } | |
1157 | ||
1158 | /* Is object pointed to by @data of @size already copied to our safe buffer? */ | |
1159 | static bool btf_show_obj_is_safe(struct btf_show *show, void *data, int size) | |
1160 | { | |
1161 | return data >= show->obj.data && | |
1162 | (data + size) < (show->obj.data + BTF_SHOW_OBJ_SAFE_SIZE); | |
1163 | } | |
1164 | ||
1165 | /* | |
1166 | * If object pointed to by @data of @size falls within our safe buffer, return | |
1167 | * the equivalent pointer to the same safe data. Assumes | |
1168 | * copy_from_kernel_nofault() has already happened and our safe buffer is | |
1169 | * populated. | |
1170 | */ | |
1171 | static void *__btf_show_obj_safe(struct btf_show *show, void *data, int size) | |
1172 | { | |
1173 | if (btf_show_obj_is_safe(show, data, size)) | |
1174 | return show->obj.safe + (data - show->obj.data); | |
1175 | return NULL; | |
1176 | } | |
1177 | ||
1178 | /* | |
1179 | * Return a safe-to-access version of data pointed to by @data. | |
1180 | * We do this by copying the relevant amount of information | |
1181 | * to the struct btf_show obj.safe buffer using copy_from_kernel_nofault(). | |
1182 | * | |
1183 | * If BTF_SHOW_UNSAFE is specified, just return data as-is; no | |
1184 | * safe copy is needed. | |
1185 | * | |
1186 | * Otherwise we need to determine if we have the required amount | |
1187 | * of data (determined by the @data pointer and the size of the | |
1188 | * largest base type we can encounter (represented by | |
1189 | * BTF_SHOW_OBJ_BASE_TYPE_SIZE). Having that much data ensures | |
1190 | * that we will be able to print some of the current object, | |
1191 | * and if more is needed a copy will be triggered. | |
1192 | * Some objects such as structs will not fit into the buffer; | |
1193 | * in such cases additional copies when we iterate over their | |
1194 | * members may be needed. | |
1195 | * | |
1196 | * btf_show_obj_safe() is used to return a safe buffer for | |
1197 | * btf_show_start_type(); this ensures that as we recurse into | |
1198 | * nested types we always have safe data for the given type. | |
1199 | * This approach is somewhat wasteful; it's possible for example | |
1200 | * that when iterating over a large union we'll end up copying the | |
1201 | * same data repeatedly, but the goal is safety not performance. | |
1202 | * We use stack data as opposed to per-CPU buffers because the | |
1203 | * iteration over a type can take some time, and preemption handling | |
1204 | * would greatly complicate use of the safe buffer. | |
1205 | */ | |
1206 | static void *btf_show_obj_safe(struct btf_show *show, | |
1207 | const struct btf_type *t, | |
1208 | void *data) | |
1209 | { | |
1210 | const struct btf_type *rt; | |
1211 | int size_left, size; | |
1212 | void *safe = NULL; | |
1213 | ||
1214 | if (show->flags & BTF_SHOW_UNSAFE) | |
1215 | return data; | |
1216 | ||
1217 | rt = btf_resolve_size(show->btf, t, &size); | |
1218 | if (IS_ERR(rt)) { | |
1219 | show->state.status = PTR_ERR(rt); | |
1220 | return NULL; | |
1221 | } | |
1222 | ||
1223 | /* | |
1224 | * Is this toplevel object? If so, set total object size and | |
1225 | * initialize pointers. Otherwise check if we still fall within | |
1226 | * our safe object data. | |
1227 | */ | |
1228 | if (show->state.depth == 0) { | |
1229 | show->obj.size = size; | |
1230 | show->obj.head = data; | |
1231 | } else { | |
1232 | /* | |
1233 | * If the size of the current object is > our remaining | |
1234 | * safe buffer we _may_ need to do a new copy. However | |
1235 | * consider the case of a nested struct; it's size pushes | |
1236 | * us over the safe buffer limit, but showing any individual | |
1237 | * struct members does not. In such cases, we don't need | |
1238 | * to initiate a fresh copy yet; however we definitely need | |
1239 | * at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes left | |
1240 | * in our buffer, regardless of the current object size. | |
1241 | * The logic here is that as we resolve types we will | |
1242 | * hit a base type at some point, and we need to be sure | |
1243 | * the next chunk of data is safely available to display | |
1244 | * that type info safely. We cannot rely on the size of | |
1245 | * the current object here because it may be much larger | |
1246 | * than our current buffer (e.g. task_struct is 8k). | |
1247 | * All we want to do here is ensure that we can print the | |
1248 | * next basic type, which we can if either | |
1249 | * - the current type size is within the safe buffer; or | |
1250 | * - at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes are left in | |
1251 | * the safe buffer. | |
1252 | */ | |
1253 | safe = __btf_show_obj_safe(show, data, | |
1254 | min(size, | |
1255 | BTF_SHOW_OBJ_BASE_TYPE_SIZE)); | |
1256 | } | |
1257 | ||
1258 | /* | |
1259 | * We need a new copy to our safe object, either because we haven't | |
8fb33b60 | 1260 | * yet copied and are initializing safe data, or because the data |
31d0bc81 AM |
1261 | * we want falls outside the boundaries of the safe object. |
1262 | */ | |
1263 | if (!safe) { | |
1264 | size_left = btf_show_obj_size_left(show, data); | |
1265 | if (size_left > BTF_SHOW_OBJ_SAFE_SIZE) | |
1266 | size_left = BTF_SHOW_OBJ_SAFE_SIZE; | |
1267 | show->state.status = copy_from_kernel_nofault(show->obj.safe, | |
1268 | data, size_left); | |
1269 | if (!show->state.status) { | |
1270 | show->obj.data = data; | |
1271 | safe = show->obj.safe; | |
1272 | } | |
1273 | } | |
1274 | ||
1275 | return safe; | |
1276 | } | |
1277 | ||
1278 | /* | |
1279 | * Set the type we are starting to show and return a safe data pointer | |
1280 | * to be used for showing the associated data. | |
1281 | */ | |
1282 | static void *btf_show_start_type(struct btf_show *show, | |
1283 | const struct btf_type *t, | |
1284 | u32 type_id, void *data) | |
1285 | { | |
1286 | show->state.type = t; | |
1287 | show->state.type_id = type_id; | |
1288 | show->state.name[0] = '\0'; | |
1289 | ||
1290 | return btf_show_obj_safe(show, t, data); | |
1291 | } | |
1292 | ||
1293 | static void btf_show_end_type(struct btf_show *show) | |
1294 | { | |
1295 | show->state.type = NULL; | |
1296 | show->state.type_id = 0; | |
1297 | show->state.name[0] = '\0'; | |
1298 | } | |
1299 | ||
1300 | static void *btf_show_start_aggr_type(struct btf_show *show, | |
1301 | const struct btf_type *t, | |
1302 | u32 type_id, void *data) | |
1303 | { | |
1304 | void *safe_data = btf_show_start_type(show, t, type_id, data); | |
1305 | ||
1306 | if (!safe_data) | |
1307 | return safe_data; | |
1308 | ||
1309 | btf_show(show, "%s%s%s", btf_show_indent(show), | |
1310 | btf_show_name(show), | |
1311 | btf_show_newline(show)); | |
1312 | show->state.depth++; | |
1313 | return safe_data; | |
1314 | } | |
1315 | ||
1316 | static void btf_show_end_aggr_type(struct btf_show *show, | |
1317 | const char *suffix) | |
1318 | { | |
1319 | show->state.depth--; | |
1320 | btf_show(show, "%s%s%s%s", btf_show_indent(show), suffix, | |
1321 | btf_show_delim(show), btf_show_newline(show)); | |
1322 | btf_show_end_type(show); | |
1323 | } | |
1324 | ||
1325 | static void btf_show_start_member(struct btf_show *show, | |
1326 | const struct btf_member *m) | |
1327 | { | |
1328 | show->state.member = m; | |
1329 | } | |
1330 | ||
1331 | static void btf_show_start_array_member(struct btf_show *show) | |
1332 | { | |
1333 | show->state.array_member = 1; | |
1334 | btf_show_start_member(show, NULL); | |
1335 | } | |
1336 | ||
1337 | static void btf_show_end_member(struct btf_show *show) | |
1338 | { | |
1339 | show->state.member = NULL; | |
1340 | } | |
1341 | ||
1342 | static void btf_show_end_array_member(struct btf_show *show) | |
1343 | { | |
1344 | show->state.array_member = 0; | |
1345 | btf_show_end_member(show); | |
1346 | } | |
1347 | ||
1348 | static void *btf_show_start_array_type(struct btf_show *show, | |
1349 | const struct btf_type *t, | |
1350 | u32 type_id, | |
1351 | u16 array_encoding, | |
1352 | void *data) | |
1353 | { | |
1354 | show->state.array_encoding = array_encoding; | |
1355 | show->state.array_terminated = 0; | |
1356 | return btf_show_start_aggr_type(show, t, type_id, data); | |
1357 | } | |
1358 | ||
1359 | static void btf_show_end_array_type(struct btf_show *show) | |
1360 | { | |
1361 | show->state.array_encoding = 0; | |
1362 | show->state.array_terminated = 0; | |
1363 | btf_show_end_aggr_type(show, "]"); | |
1364 | } | |
1365 | ||
1366 | static void *btf_show_start_struct_type(struct btf_show *show, | |
1367 | const struct btf_type *t, | |
1368 | u32 type_id, | |
1369 | void *data) | |
1370 | { | |
1371 | return btf_show_start_aggr_type(show, t, type_id, data); | |
1372 | } | |
1373 | ||
1374 | static void btf_show_end_struct_type(struct btf_show *show) | |
1375 | { | |
1376 | btf_show_end_aggr_type(show, "}"); | |
1377 | } | |
1378 | ||
69b693f0 MKL |
1379 | __printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log, |
1380 | const char *fmt, ...) | |
1381 | { | |
1382 | va_list args; | |
1383 | ||
1384 | va_start(args, fmt); | |
1385 | bpf_verifier_vlog(log, fmt, args); | |
1386 | va_end(args); | |
1387 | } | |
1388 | ||
1389 | __printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env, | |
1390 | const char *fmt, ...) | |
1391 | { | |
1392 | struct bpf_verifier_log *log = &env->log; | |
1393 | va_list args; | |
1394 | ||
1395 | if (!bpf_verifier_log_needed(log)) | |
1396 | return; | |
1397 | ||
1398 | va_start(args, fmt); | |
1399 | bpf_verifier_vlog(log, fmt, args); | |
1400 | va_end(args); | |
1401 | } | |
1402 | ||
1403 | __printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env, | |
1404 | const struct btf_type *t, | |
1405 | bool log_details, | |
1406 | const char *fmt, ...) | |
1407 | { | |
1408 | struct bpf_verifier_log *log = &env->log; | |
69b693f0 MKL |
1409 | struct btf *btf = env->btf; |
1410 | va_list args; | |
1411 | ||
1412 | if (!bpf_verifier_log_needed(log)) | |
1413 | return; | |
1414 | ||
9cb61e50 CB |
1415 | if (log->level == BPF_LOG_KERNEL) { |
1416 | /* btf verifier prints all types it is processing via | |
1417 | * btf_verifier_log_type(..., fmt = NULL). | |
1418 | * Skip those prints for in-kernel BTF verification. | |
1419 | */ | |
1420 | if (!fmt) | |
1421 | return; | |
1422 | ||
1423 | /* Skip logging when loading module BTF with mismatches permitted */ | |
1424 | if (env->btf->base_btf && IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) | |
1425 | return; | |
1426 | } | |
8580ac94 | 1427 | |
69b693f0 MKL |
1428 | __btf_verifier_log(log, "[%u] %s %s%s", |
1429 | env->log_type_id, | |
571f9738 | 1430 | btf_type_str(t), |
23127b33 | 1431 | __btf_name_by_offset(btf, t->name_off), |
69b693f0 MKL |
1432 | log_details ? " " : ""); |
1433 | ||
1434 | if (log_details) | |
1435 | btf_type_ops(t)->log_details(env, t); | |
1436 | ||
1437 | if (fmt && *fmt) { | |
1438 | __btf_verifier_log(log, " "); | |
1439 | va_start(args, fmt); | |
1440 | bpf_verifier_vlog(log, fmt, args); | |
1441 | va_end(args); | |
1442 | } | |
1443 | ||
1444 | __btf_verifier_log(log, "\n"); | |
1445 | } | |
1446 | ||
1447 | #define btf_verifier_log_type(env, t, ...) \ | |
1448 | __btf_verifier_log_type((env), (t), true, __VA_ARGS__) | |
1449 | #define btf_verifier_log_basic(env, t, ...) \ | |
1450 | __btf_verifier_log_type((env), (t), false, __VA_ARGS__) | |
1451 | ||
1452 | __printf(4, 5) | |
1453 | static void btf_verifier_log_member(struct btf_verifier_env *env, | |
1454 | const struct btf_type *struct_type, | |
1455 | const struct btf_member *member, | |
1456 | const char *fmt, ...) | |
1457 | { | |
1458 | struct bpf_verifier_log *log = &env->log; | |
1459 | struct btf *btf = env->btf; | |
1460 | va_list args; | |
1461 | ||
1462 | if (!bpf_verifier_log_needed(log)) | |
1463 | return; | |
1464 | ||
9cb61e50 CB |
1465 | if (log->level == BPF_LOG_KERNEL) { |
1466 | if (!fmt) | |
1467 | return; | |
1468 | ||
1469 | /* Skip logging when loading module BTF with mismatches permitted */ | |
1470 | if (env->btf->base_btf && IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) | |
1471 | return; | |
1472 | } | |
1473 | ||
eb3f595d MKL |
1474 | /* The CHECK_META phase already did a btf dump. |
1475 | * | |
1476 | * If member is logged again, it must hit an error in | |
1477 | * parsing this member. It is useful to print out which | |
1478 | * struct this member belongs to. | |
1479 | */ | |
1480 | if (env->phase != CHECK_META) | |
1481 | btf_verifier_log_type(env, struct_type, NULL); | |
1482 | ||
9d5f9f70 YS |
1483 | if (btf_type_kflag(struct_type)) |
1484 | __btf_verifier_log(log, | |
1485 | "\t%s type_id=%u bitfield_size=%u bits_offset=%u", | |
1486 | __btf_name_by_offset(btf, member->name_off), | |
1487 | member->type, | |
1488 | BTF_MEMBER_BITFIELD_SIZE(member->offset), | |
1489 | BTF_MEMBER_BIT_OFFSET(member->offset)); | |
1490 | else | |
1491 | __btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u", | |
1492 | __btf_name_by_offset(btf, member->name_off), | |
1493 | member->type, member->offset); | |
69b693f0 MKL |
1494 | |
1495 | if (fmt && *fmt) { | |
1496 | __btf_verifier_log(log, " "); | |
1497 | va_start(args, fmt); | |
1498 | bpf_verifier_vlog(log, fmt, args); | |
1499 | va_end(args); | |
1500 | } | |
1501 | ||
1502 | __btf_verifier_log(log, "\n"); | |
1503 | } | |
1504 | ||
1dc92851 DB |
1505 | __printf(4, 5) |
1506 | static void btf_verifier_log_vsi(struct btf_verifier_env *env, | |
1507 | const struct btf_type *datasec_type, | |
1508 | const struct btf_var_secinfo *vsi, | |
1509 | const char *fmt, ...) | |
1510 | { | |
1511 | struct bpf_verifier_log *log = &env->log; | |
1512 | va_list args; | |
1513 | ||
1514 | if (!bpf_verifier_log_needed(log)) | |
1515 | return; | |
8580ac94 AS |
1516 | if (log->level == BPF_LOG_KERNEL && !fmt) |
1517 | return; | |
1dc92851 DB |
1518 | if (env->phase != CHECK_META) |
1519 | btf_verifier_log_type(env, datasec_type, NULL); | |
1520 | ||
1521 | __btf_verifier_log(log, "\t type_id=%u offset=%u size=%u", | |
1522 | vsi->type, vsi->offset, vsi->size); | |
1523 | if (fmt && *fmt) { | |
1524 | __btf_verifier_log(log, " "); | |
1525 | va_start(args, fmt); | |
1526 | bpf_verifier_vlog(log, fmt, args); | |
1527 | va_end(args); | |
1528 | } | |
1529 | ||
1530 | __btf_verifier_log(log, "\n"); | |
1531 | } | |
1532 | ||
f80442a4 MKL |
1533 | static void btf_verifier_log_hdr(struct btf_verifier_env *env, |
1534 | u32 btf_data_size) | |
69b693f0 MKL |
1535 | { |
1536 | struct bpf_verifier_log *log = &env->log; | |
1537 | const struct btf *btf = env->btf; | |
1538 | const struct btf_header *hdr; | |
1539 | ||
1540 | if (!bpf_verifier_log_needed(log)) | |
1541 | return; | |
1542 | ||
8580ac94 AS |
1543 | if (log->level == BPF_LOG_KERNEL) |
1544 | return; | |
f80442a4 | 1545 | hdr = &btf->hdr; |
69b693f0 MKL |
1546 | __btf_verifier_log(log, "magic: 0x%x\n", hdr->magic); |
1547 | __btf_verifier_log(log, "version: %u\n", hdr->version); | |
1548 | __btf_verifier_log(log, "flags: 0x%x\n", hdr->flags); | |
f80442a4 | 1549 | __btf_verifier_log(log, "hdr_len: %u\n", hdr->hdr_len); |
69b693f0 | 1550 | __btf_verifier_log(log, "type_off: %u\n", hdr->type_off); |
f80442a4 | 1551 | __btf_verifier_log(log, "type_len: %u\n", hdr->type_len); |
69b693f0 MKL |
1552 | __btf_verifier_log(log, "str_off: %u\n", hdr->str_off); |
1553 | __btf_verifier_log(log, "str_len: %u\n", hdr->str_len); | |
f80442a4 | 1554 | __btf_verifier_log(log, "btf_total_size: %u\n", btf_data_size); |
69b693f0 MKL |
1555 | } |
1556 | ||
1557 | static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t) | |
1558 | { | |
1559 | struct btf *btf = env->btf; | |
1560 | ||
951bb646 | 1561 | if (btf->types_size == btf->nr_types) { |
69b693f0 MKL |
1562 | /* Expand 'types' array */ |
1563 | ||
1564 | struct btf_type **new_types; | |
1565 | u32 expand_by, new_size; | |
1566 | ||
951bb646 | 1567 | if (btf->start_id + btf->types_size == BTF_MAX_TYPE) { |
69b693f0 MKL |
1568 | btf_verifier_log(env, "Exceeded max num of types"); |
1569 | return -E2BIG; | |
1570 | } | |
1571 | ||
1572 | expand_by = max_t(u32, btf->types_size >> 2, 16); | |
aea2f7b8 | 1573 | new_size = min_t(u32, BTF_MAX_TYPE, |
69b693f0 MKL |
1574 | btf->types_size + expand_by); |
1575 | ||
778e1cdd | 1576 | new_types = kvcalloc(new_size, sizeof(*new_types), |
69b693f0 MKL |
1577 | GFP_KERNEL | __GFP_NOWARN); |
1578 | if (!new_types) | |
1579 | return -ENOMEM; | |
1580 | ||
951bb646 AN |
1581 | if (btf->nr_types == 0) { |
1582 | if (!btf->base_btf) { | |
1583 | /* lazily init VOID type */ | |
1584 | new_types[0] = &btf_void; | |
1585 | btf->nr_types++; | |
1586 | } | |
1587 | } else { | |
69b693f0 | 1588 | memcpy(new_types, btf->types, |
951bb646 AN |
1589 | sizeof(*btf->types) * btf->nr_types); |
1590 | } | |
69b693f0 MKL |
1591 | |
1592 | kvfree(btf->types); | |
1593 | btf->types = new_types; | |
1594 | btf->types_size = new_size; | |
1595 | } | |
1596 | ||
951bb646 | 1597 | btf->types[btf->nr_types++] = t; |
69b693f0 MKL |
1598 | |
1599 | return 0; | |
1600 | } | |
1601 | ||
78958fca MKL |
1602 | static int btf_alloc_id(struct btf *btf) |
1603 | { | |
1604 | int id; | |
1605 | ||
1606 | idr_preload(GFP_KERNEL); | |
1607 | spin_lock_bh(&btf_idr_lock); | |
1608 | id = idr_alloc_cyclic(&btf_idr, btf, 1, INT_MAX, GFP_ATOMIC); | |
1609 | if (id > 0) | |
1610 | btf->id = id; | |
1611 | spin_unlock_bh(&btf_idr_lock); | |
1612 | idr_preload_end(); | |
1613 | ||
1614 | if (WARN_ON_ONCE(!id)) | |
1615 | return -ENOSPC; | |
1616 | ||
1617 | return id > 0 ? 0 : id; | |
1618 | } | |
1619 | ||
1620 | static void btf_free_id(struct btf *btf) | |
1621 | { | |
1622 | unsigned long flags; | |
1623 | ||
1624 | /* | |
1625 | * In map-in-map, calling map_delete_elem() on outer | |
1626 | * map will call bpf_map_put on the inner map. | |
1627 | * It will then eventually call btf_free_id() | |
1628 | * on the inner map. Some of the map_delete_elem() | |
1629 | * implementation may have irq disabled, so | |
1630 | * we need to use the _irqsave() version instead | |
1631 | * of the _bh() version. | |
1632 | */ | |
1633 | spin_lock_irqsave(&btf_idr_lock, flags); | |
1634 | idr_remove(&btf_idr, btf->id); | |
1635 | spin_unlock_irqrestore(&btf_idr_lock, flags); | |
1636 | } | |
1637 | ||
dee872e1 KKD |
1638 | static void btf_free_kfunc_set_tab(struct btf *btf) |
1639 | { | |
1640 | struct btf_kfunc_set_tab *tab = btf->kfunc_set_tab; | |
a4703e31 | 1641 | int hook; |
dee872e1 KKD |
1642 | |
1643 | if (!tab) | |
1644 | return; | |
1645 | /* For module BTF, we directly assign the sets being registered, so | |
1646 | * there is nothing to free except kfunc_set_tab. | |
1647 | */ | |
1648 | if (btf_is_module(btf)) | |
1649 | goto free_tab; | |
a4703e31 KKD |
1650 | for (hook = 0; hook < ARRAY_SIZE(tab->sets); hook++) |
1651 | kfree(tab->sets[hook]); | |
dee872e1 KKD |
1652 | free_tab: |
1653 | kfree(tab); | |
1654 | btf->kfunc_set_tab = NULL; | |
1655 | } | |
1656 | ||
5ce937d6 KKD |
1657 | static void btf_free_dtor_kfunc_tab(struct btf *btf) |
1658 | { | |
1659 | struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab; | |
1660 | ||
1661 | if (!tab) | |
1662 | return; | |
1663 | kfree(tab); | |
1664 | btf->dtor_kfunc_tab = NULL; | |
1665 | } | |
1666 | ||
8ffa5cc1 KKD |
1667 | static void btf_struct_metas_free(struct btf_struct_metas *tab) |
1668 | { | |
1669 | int i; | |
1670 | ||
1671 | if (!tab) | |
1672 | return; | |
cd2a8079 | 1673 | for (i = 0; i < tab->cnt; i++) |
8ffa5cc1 | 1674 | btf_record_free(tab->types[i].record); |
8ffa5cc1 KKD |
1675 | kfree(tab); |
1676 | } | |
1677 | ||
1678 | static void btf_free_struct_meta_tab(struct btf *btf) | |
1679 | { | |
1680 | struct btf_struct_metas *tab = btf->struct_meta_tab; | |
1681 | ||
1682 | btf_struct_metas_free(tab); | |
1683 | btf->struct_meta_tab = NULL; | |
1684 | } | |
1685 | ||
69b693f0 MKL |
1686 | static void btf_free(struct btf *btf) |
1687 | { | |
8ffa5cc1 | 1688 | btf_free_struct_meta_tab(btf); |
5ce937d6 | 1689 | btf_free_dtor_kfunc_tab(btf); |
dee872e1 | 1690 | btf_free_kfunc_set_tab(btf); |
69b693f0 | 1691 | kvfree(btf->types); |
eb3f595d MKL |
1692 | kvfree(btf->resolved_sizes); |
1693 | kvfree(btf->resolved_ids); | |
69b693f0 MKL |
1694 | kvfree(btf->data); |
1695 | kfree(btf); | |
1696 | } | |
1697 | ||
78958fca | 1698 | static void btf_free_rcu(struct rcu_head *rcu) |
f56a653c | 1699 | { |
78958fca MKL |
1700 | struct btf *btf = container_of(rcu, struct btf, rcu); |
1701 | ||
1702 | btf_free(btf); | |
f56a653c MKL |
1703 | } |
1704 | ||
22dc4a0f AN |
1705 | void btf_get(struct btf *btf) |
1706 | { | |
1707 | refcount_inc(&btf->refcnt); | |
1708 | } | |
1709 | ||
f56a653c MKL |
1710 | void btf_put(struct btf *btf) |
1711 | { | |
78958fca MKL |
1712 | if (btf && refcount_dec_and_test(&btf->refcnt)) { |
1713 | btf_free_id(btf); | |
1714 | call_rcu(&btf->rcu, btf_free_rcu); | |
1715 | } | |
f56a653c MKL |
1716 | } |
1717 | ||
eb3f595d MKL |
1718 | static int env_resolve_init(struct btf_verifier_env *env) |
1719 | { | |
1720 | struct btf *btf = env->btf; | |
1721 | u32 nr_types = btf->nr_types; | |
1722 | u32 *resolved_sizes = NULL; | |
1723 | u32 *resolved_ids = NULL; | |
1724 | u8 *visit_states = NULL; | |
1725 | ||
951bb646 | 1726 | resolved_sizes = kvcalloc(nr_types, sizeof(*resolved_sizes), |
eb3f595d MKL |
1727 | GFP_KERNEL | __GFP_NOWARN); |
1728 | if (!resolved_sizes) | |
1729 | goto nomem; | |
1730 | ||
951bb646 | 1731 | resolved_ids = kvcalloc(nr_types, sizeof(*resolved_ids), |
eb3f595d MKL |
1732 | GFP_KERNEL | __GFP_NOWARN); |
1733 | if (!resolved_ids) | |
1734 | goto nomem; | |
1735 | ||
951bb646 | 1736 | visit_states = kvcalloc(nr_types, sizeof(*visit_states), |
eb3f595d MKL |
1737 | GFP_KERNEL | __GFP_NOWARN); |
1738 | if (!visit_states) | |
1739 | goto nomem; | |
1740 | ||
1741 | btf->resolved_sizes = resolved_sizes; | |
1742 | btf->resolved_ids = resolved_ids; | |
1743 | env->visit_states = visit_states; | |
1744 | ||
1745 | return 0; | |
1746 | ||
1747 | nomem: | |
1748 | kvfree(resolved_sizes); | |
1749 | kvfree(resolved_ids); | |
1750 | kvfree(visit_states); | |
1751 | return -ENOMEM; | |
1752 | } | |
1753 | ||
69b693f0 MKL |
1754 | static void btf_verifier_env_free(struct btf_verifier_env *env) |
1755 | { | |
eb3f595d | 1756 | kvfree(env->visit_states); |
69b693f0 MKL |
1757 | kfree(env); |
1758 | } | |
1759 | ||
eb3f595d MKL |
1760 | static bool env_type_is_resolve_sink(const struct btf_verifier_env *env, |
1761 | const struct btf_type *next_type) | |
1762 | { | |
1763 | switch (env->resolve_mode) { | |
1764 | case RESOLVE_TBD: | |
1765 | /* int, enum or void is a sink */ | |
1766 | return !btf_type_needs_resolve(next_type); | |
1767 | case RESOLVE_PTR: | |
2667a262 MKL |
1768 | /* int, enum, void, struct, array, func or func_proto is a sink |
1769 | * for ptr | |
1770 | */ | |
eb3f595d MKL |
1771 | return !btf_type_is_modifier(next_type) && |
1772 | !btf_type_is_ptr(next_type); | |
1773 | case RESOLVE_STRUCT_OR_ARRAY: | |
2667a262 MKL |
1774 | /* int, enum, void, ptr, func or func_proto is a sink |
1775 | * for struct and array | |
1776 | */ | |
eb3f595d MKL |
1777 | return !btf_type_is_modifier(next_type) && |
1778 | !btf_type_is_array(next_type) && | |
1779 | !btf_type_is_struct(next_type); | |
1780 | default: | |
53c8036c | 1781 | BUG(); |
eb3f595d MKL |
1782 | } |
1783 | } | |
1784 | ||
1785 | static bool env_type_is_resolved(const struct btf_verifier_env *env, | |
1786 | u32 type_id) | |
1787 | { | |
951bb646 AN |
1788 | /* base BTF types should be resolved by now */ |
1789 | if (type_id < env->btf->start_id) | |
1790 | return true; | |
1791 | ||
1792 | return env->visit_states[type_id - env->btf->start_id] == RESOLVED; | |
eb3f595d MKL |
1793 | } |
1794 | ||
1795 | static int env_stack_push(struct btf_verifier_env *env, | |
1796 | const struct btf_type *t, u32 type_id) | |
1797 | { | |
951bb646 | 1798 | const struct btf *btf = env->btf; |
eb3f595d MKL |
1799 | struct resolve_vertex *v; |
1800 | ||
1801 | if (env->top_stack == MAX_RESOLVE_DEPTH) | |
1802 | return -E2BIG; | |
1803 | ||
951bb646 AN |
1804 | if (type_id < btf->start_id |
1805 | || env->visit_states[type_id - btf->start_id] != NOT_VISITED) | |
eb3f595d MKL |
1806 | return -EEXIST; |
1807 | ||
951bb646 | 1808 | env->visit_states[type_id - btf->start_id] = VISITED; |
eb3f595d MKL |
1809 | |
1810 | v = &env->stack[env->top_stack++]; | |
1811 | v->t = t; | |
1812 | v->type_id = type_id; | |
1813 | v->next_member = 0; | |
1814 | ||
1815 | if (env->resolve_mode == RESOLVE_TBD) { | |
1816 | if (btf_type_is_ptr(t)) | |
1817 | env->resolve_mode = RESOLVE_PTR; | |
1818 | else if (btf_type_is_struct(t) || btf_type_is_array(t)) | |
1819 | env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY; | |
1820 | } | |
1821 | ||
1822 | return 0; | |
1823 | } | |
1824 | ||
1825 | static void env_stack_set_next_member(struct btf_verifier_env *env, | |
1826 | u16 next_member) | |
1827 | { | |
1828 | env->stack[env->top_stack - 1].next_member = next_member; | |
1829 | } | |
1830 | ||
1831 | static void env_stack_pop_resolved(struct btf_verifier_env *env, | |
1832 | u32 resolved_type_id, | |
1833 | u32 resolved_size) | |
1834 | { | |
1835 | u32 type_id = env->stack[--(env->top_stack)].type_id; | |
1836 | struct btf *btf = env->btf; | |
1837 | ||
951bb646 | 1838 | type_id -= btf->start_id; /* adjust to local type id */ |
eb3f595d MKL |
1839 | btf->resolved_sizes[type_id] = resolved_size; |
1840 | btf->resolved_ids[type_id] = resolved_type_id; | |
1841 | env->visit_states[type_id] = RESOLVED; | |
1842 | } | |
1843 | ||
1844 | static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env) | |
1845 | { | |
1846 | return env->top_stack ? &env->stack[env->top_stack - 1] : NULL; | |
1847 | } | |
1848 | ||
7e3617a7 MKL |
1849 | /* Resolve the size of a passed-in "type" |
1850 | * | |
1851 | * type: is an array (e.g. u32 array[x][y]) | |
1852 | * return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY, | |
1853 | * *type_size: (x * y * sizeof(u32)). Hence, *type_size always | |
1854 | * corresponds to the return type. | |
1855 | * *elem_type: u32 | |
69ff3047 | 1856 | * *elem_id: id of u32 |
7e3617a7 MKL |
1857 | * *total_nelems: (x * y). Hence, individual elem size is |
1858 | * (*type_size / *total_nelems) | |
887c31a3 | 1859 | * *type_id: id of type if it's changed within the function, 0 if not |
7e3617a7 MKL |
1860 | * |
1861 | * type: is not an array (e.g. const struct X) | |
1862 | * return type: type "struct X" | |
1863 | * *type_size: sizeof(struct X) | |
1864 | * *elem_type: same as return type ("struct X") | |
69ff3047 | 1865 | * *elem_id: 0 |
7e3617a7 | 1866 | * *total_nelems: 1 |
887c31a3 | 1867 | * *type_id: id of type if it's changed within the function, 0 if not |
7e3617a7 | 1868 | */ |
6298399b JO |
1869 | static const struct btf_type * |
1870 | __btf_resolve_size(const struct btf *btf, const struct btf_type *type, | |
1871 | u32 *type_size, const struct btf_type **elem_type, | |
887c31a3 | 1872 | u32 *elem_id, u32 *total_nelems, u32 *type_id) |
7e3617a7 MKL |
1873 | { |
1874 | const struct btf_type *array_type = NULL; | |
69ff3047 | 1875 | const struct btf_array *array = NULL; |
887c31a3 | 1876 | u32 i, size, nelems = 1, id = 0; |
7e3617a7 MKL |
1877 | |
1878 | for (i = 0; i < MAX_RESOLVE_DEPTH; i++) { | |
1879 | switch (BTF_INFO_KIND(type->info)) { | |
1880 | /* type->size can be used */ | |
1881 | case BTF_KIND_INT: | |
1882 | case BTF_KIND_STRUCT: | |
1883 | case BTF_KIND_UNION: | |
1884 | case BTF_KIND_ENUM: | |
b1828f0b | 1885 | case BTF_KIND_FLOAT: |
6089fb32 | 1886 | case BTF_KIND_ENUM64: |
7e3617a7 MKL |
1887 | size = type->size; |
1888 | goto resolved; | |
1889 | ||
1890 | case BTF_KIND_PTR: | |
1891 | size = sizeof(void *); | |
1892 | goto resolved; | |
1893 | ||
1894 | /* Modifiers */ | |
1895 | case BTF_KIND_TYPEDEF: | |
1896 | case BTF_KIND_VOLATILE: | |
1897 | case BTF_KIND_CONST: | |
1898 | case BTF_KIND_RESTRICT: | |
8c42d2fa | 1899 | case BTF_KIND_TYPE_TAG: |
887c31a3 | 1900 | id = type->type; |
7e3617a7 MKL |
1901 | type = btf_type_by_id(btf, type->type); |
1902 | break; | |
1903 | ||
1904 | case BTF_KIND_ARRAY: | |
1905 | if (!array_type) | |
1906 | array_type = type; | |
1907 | array = btf_type_array(type); | |
1908 | if (nelems && array->nelems > U32_MAX / nelems) | |
1909 | return ERR_PTR(-EINVAL); | |
1910 | nelems *= array->nelems; | |
1911 | type = btf_type_by_id(btf, array->type); | |
1912 | break; | |
1913 | ||
1914 | /* type without size */ | |
1915 | default: | |
1916 | return ERR_PTR(-EINVAL); | |
1917 | } | |
1918 | } | |
1919 | ||
1920 | return ERR_PTR(-EINVAL); | |
1921 | ||
1922 | resolved: | |
1923 | if (nelems && size > U32_MAX / nelems) | |
1924 | return ERR_PTR(-EINVAL); | |
1925 | ||
1926 | *type_size = nelems * size; | |
85d33df3 MKL |
1927 | if (total_nelems) |
1928 | *total_nelems = nelems; | |
1929 | if (elem_type) | |
1930 | *elem_type = type; | |
69ff3047 JO |
1931 | if (elem_id) |
1932 | *elem_id = array ? array->type : 0; | |
887c31a3 JO |
1933 | if (type_id && id) |
1934 | *type_id = id; | |
7e3617a7 MKL |
1935 | |
1936 | return array_type ? : type; | |
1937 | } | |
1938 | ||
6298399b JO |
1939 | const struct btf_type * |
1940 | btf_resolve_size(const struct btf *btf, const struct btf_type *type, | |
1941 | u32 *type_size) | |
1942 | { | |
887c31a3 | 1943 | return __btf_resolve_size(btf, type, type_size, NULL, NULL, NULL, NULL); |
6298399b JO |
1944 | } |
1945 | ||
951bb646 AN |
1946 | static u32 btf_resolved_type_id(const struct btf *btf, u32 type_id) |
1947 | { | |
1948 | while (type_id < btf->start_id) | |
1949 | btf = btf->base_btf; | |
1950 | ||
1951 | return btf->resolved_ids[type_id - btf->start_id]; | |
1952 | } | |
1953 | ||
eb3f595d MKL |
1954 | /* The input param "type_id" must point to a needs_resolve type */ |
1955 | static const struct btf_type *btf_type_id_resolve(const struct btf *btf, | |
1956 | u32 *type_id) | |
1957 | { | |
951bb646 | 1958 | *type_id = btf_resolved_type_id(btf, *type_id); |
eb3f595d MKL |
1959 | return btf_type_by_id(btf, *type_id); |
1960 | } | |
1961 | ||
951bb646 AN |
1962 | static u32 btf_resolved_type_size(const struct btf *btf, u32 type_id) |
1963 | { | |
1964 | while (type_id < btf->start_id) | |
1965 | btf = btf->base_btf; | |
1966 | ||
1967 | return btf->resolved_sizes[type_id - btf->start_id]; | |
1968 | } | |
1969 | ||
eb3f595d MKL |
1970 | const struct btf_type *btf_type_id_size(const struct btf *btf, |
1971 | u32 *type_id, u32 *ret_size) | |
1972 | { | |
1973 | const struct btf_type *size_type; | |
1974 | u32 size_type_id = *type_id; | |
1975 | u32 size = 0; | |
1976 | ||
1977 | size_type = btf_type_by_id(btf, size_type_id); | |
b47a0bd2 | 1978 | if (btf_type_nosize_or_null(size_type)) |
eb3f595d MKL |
1979 | return NULL; |
1980 | ||
1981 | if (btf_type_has_size(size_type)) { | |
1982 | size = size_type->size; | |
1983 | } else if (btf_type_is_array(size_type)) { | |
951bb646 | 1984 | size = btf_resolved_type_size(btf, size_type_id); |
eb3f595d MKL |
1985 | } else if (btf_type_is_ptr(size_type)) { |
1986 | size = sizeof(void *); | |
1987 | } else { | |
1dc92851 DB |
1988 | if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) && |
1989 | !btf_type_is_var(size_type))) | |
eb3f595d MKL |
1990 | return NULL; |
1991 | ||
951bb646 | 1992 | size_type_id = btf_resolved_type_id(btf, size_type_id); |
eb3f595d | 1993 | size_type = btf_type_by_id(btf, size_type_id); |
b47a0bd2 | 1994 | if (btf_type_nosize_or_null(size_type)) |
eb3f595d | 1995 | return NULL; |
1acc5d5c AN |
1996 | else if (btf_type_has_size(size_type)) |
1997 | size = size_type->size; | |
1998 | else if (btf_type_is_array(size_type)) | |
951bb646 | 1999 | size = btf_resolved_type_size(btf, size_type_id); |
1acc5d5c AN |
2000 | else if (btf_type_is_ptr(size_type)) |
2001 | size = sizeof(void *); | |
2002 | else | |
2003 | return NULL; | |
eb3f595d MKL |
2004 | } |
2005 | ||
2006 | *type_id = size_type_id; | |
2007 | if (ret_size) | |
2008 | *ret_size = size; | |
2009 | ||
2010 | return size_type; | |
2011 | } | |
2012 | ||
179cde8c MKL |
2013 | static int btf_df_check_member(struct btf_verifier_env *env, |
2014 | const struct btf_type *struct_type, | |
2015 | const struct btf_member *member, | |
2016 | const struct btf_type *member_type) | |
2017 | { | |
2018 | btf_verifier_log_basic(env, struct_type, | |
2019 | "Unsupported check_member"); | |
2020 | return -EINVAL; | |
2021 | } | |
2022 | ||
9d5f9f70 YS |
2023 | static int btf_df_check_kflag_member(struct btf_verifier_env *env, |
2024 | const struct btf_type *struct_type, | |
2025 | const struct btf_member *member, | |
2026 | const struct btf_type *member_type) | |
2027 | { | |
2028 | btf_verifier_log_basic(env, struct_type, | |
2029 | "Unsupported check_kflag_member"); | |
2030 | return -EINVAL; | |
2031 | } | |
2032 | ||
b1828f0b | 2033 | /* Used for ptr, array struct/union and float type members. |
9d5f9f70 YS |
2034 | * int, enum and modifier types have their specific callback functions. |
2035 | */ | |
2036 | static int btf_generic_check_kflag_member(struct btf_verifier_env *env, | |
2037 | const struct btf_type *struct_type, | |
2038 | const struct btf_member *member, | |
2039 | const struct btf_type *member_type) | |
2040 | { | |
2041 | if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) { | |
2042 | btf_verifier_log_member(env, struct_type, member, | |
2043 | "Invalid member bitfield_size"); | |
2044 | return -EINVAL; | |
2045 | } | |
2046 | ||
2047 | /* bitfield size is 0, so member->offset represents bit offset only. | |
2048 | * It is safe to call non kflag check_member variants. | |
2049 | */ | |
2050 | return btf_type_ops(member_type)->check_member(env, struct_type, | |
2051 | member, | |
2052 | member_type); | |
2053 | } | |
2054 | ||
eb3f595d MKL |
2055 | static int btf_df_resolve(struct btf_verifier_env *env, |
2056 | const struct resolve_vertex *v) | |
2057 | { | |
2058 | btf_verifier_log_basic(env, v->t, "Unsupported resolve"); | |
2059 | return -EINVAL; | |
2060 | } | |
2061 | ||
31d0bc81 AM |
2062 | static void btf_df_show(const struct btf *btf, const struct btf_type *t, |
2063 | u32 type_id, void *data, u8 bits_offsets, | |
2064 | struct btf_show *show) | |
b00b8dae | 2065 | { |
31d0bc81 | 2066 | btf_show(show, "<unsupported kind:%u>", BTF_INFO_KIND(t->info)); |
b00b8dae MKL |
2067 | } |
2068 | ||
179cde8c MKL |
2069 | static int btf_int_check_member(struct btf_verifier_env *env, |
2070 | const struct btf_type *struct_type, | |
2071 | const struct btf_member *member, | |
2072 | const struct btf_type *member_type) | |
2073 | { | |
2074 | u32 int_data = btf_type_int(member_type); | |
2075 | u32 struct_bits_off = member->offset; | |
2076 | u32 struct_size = struct_type->size; | |
2077 | u32 nr_copy_bits; | |
2078 | u32 bytes_offset; | |
2079 | ||
2080 | if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) { | |
2081 | btf_verifier_log_member(env, struct_type, member, | |
2082 | "bits_offset exceeds U32_MAX"); | |
2083 | return -EINVAL; | |
2084 | } | |
2085 | ||
2086 | struct_bits_off += BTF_INT_OFFSET(int_data); | |
2087 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2088 | nr_copy_bits = BTF_INT_BITS(int_data) + | |
2089 | BITS_PER_BYTE_MASKED(struct_bits_off); | |
2090 | ||
b1e8818c | 2091 | if (nr_copy_bits > BITS_PER_U128) { |
179cde8c | 2092 | btf_verifier_log_member(env, struct_type, member, |
b1e8818c | 2093 | "nr_copy_bits exceeds 128"); |
179cde8c MKL |
2094 | return -EINVAL; |
2095 | } | |
2096 | ||
2097 | if (struct_size < bytes_offset || | |
2098 | struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { | |
2099 | btf_verifier_log_member(env, struct_type, member, | |
2100 | "Member exceeds struct_size"); | |
2101 | return -EINVAL; | |
2102 | } | |
2103 | ||
2104 | return 0; | |
2105 | } | |
2106 | ||
9d5f9f70 YS |
2107 | static int btf_int_check_kflag_member(struct btf_verifier_env *env, |
2108 | const struct btf_type *struct_type, | |
2109 | const struct btf_member *member, | |
2110 | const struct btf_type *member_type) | |
2111 | { | |
2112 | u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset; | |
2113 | u32 int_data = btf_type_int(member_type); | |
2114 | u32 struct_size = struct_type->size; | |
2115 | u32 nr_copy_bits; | |
2116 | ||
2117 | /* a regular int type is required for the kflag int member */ | |
2118 | if (!btf_type_int_is_regular(member_type)) { | |
2119 | btf_verifier_log_member(env, struct_type, member, | |
2120 | "Invalid member base type"); | |
2121 | return -EINVAL; | |
2122 | } | |
2123 | ||
2124 | /* check sanity of bitfield size */ | |
2125 | nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); | |
2126 | struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); | |
2127 | nr_int_data_bits = BTF_INT_BITS(int_data); | |
2128 | if (!nr_bits) { | |
2129 | /* Not a bitfield member, member offset must be at byte | |
2130 | * boundary. | |
2131 | */ | |
2132 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2133 | btf_verifier_log_member(env, struct_type, member, | |
2134 | "Invalid member offset"); | |
2135 | return -EINVAL; | |
2136 | } | |
2137 | ||
2138 | nr_bits = nr_int_data_bits; | |
2139 | } else if (nr_bits > nr_int_data_bits) { | |
2140 | btf_verifier_log_member(env, struct_type, member, | |
2141 | "Invalid member bitfield_size"); | |
2142 | return -EINVAL; | |
2143 | } | |
2144 | ||
2145 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2146 | nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off); | |
b1e8818c | 2147 | if (nr_copy_bits > BITS_PER_U128) { |
9d5f9f70 | 2148 | btf_verifier_log_member(env, struct_type, member, |
b1e8818c | 2149 | "nr_copy_bits exceeds 128"); |
9d5f9f70 YS |
2150 | return -EINVAL; |
2151 | } | |
2152 | ||
2153 | if (struct_size < bytes_offset || | |
2154 | struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { | |
2155 | btf_verifier_log_member(env, struct_type, member, | |
2156 | "Member exceeds struct_size"); | |
2157 | return -EINVAL; | |
2158 | } | |
2159 | ||
2160 | return 0; | |
2161 | } | |
2162 | ||
69b693f0 MKL |
2163 | static s32 btf_int_check_meta(struct btf_verifier_env *env, |
2164 | const struct btf_type *t, | |
2165 | u32 meta_left) | |
2166 | { | |
2167 | u32 int_data, nr_bits, meta_needed = sizeof(int_data); | |
2168 | u16 encoding; | |
2169 | ||
2170 | if (meta_left < meta_needed) { | |
2171 | btf_verifier_log_basic(env, t, | |
2172 | "meta_left:%u meta_needed:%u", | |
2173 | meta_left, meta_needed); | |
2174 | return -EINVAL; | |
2175 | } | |
2176 | ||
2177 | if (btf_type_vlen(t)) { | |
2178 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2179 | return -EINVAL; | |
2180 | } | |
2181 | ||
9d5f9f70 YS |
2182 | if (btf_type_kflag(t)) { |
2183 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2184 | return -EINVAL; | |
2185 | } | |
2186 | ||
69b693f0 | 2187 | int_data = btf_type_int(t); |
aea2f7b8 MKL |
2188 | if (int_data & ~BTF_INT_MASK) { |
2189 | btf_verifier_log_basic(env, t, "Invalid int_data:%x", | |
2190 | int_data); | |
2191 | return -EINVAL; | |
2192 | } | |
2193 | ||
69b693f0 MKL |
2194 | nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data); |
2195 | ||
b1e8818c | 2196 | if (nr_bits > BITS_PER_U128) { |
69b693f0 | 2197 | btf_verifier_log_type(env, t, "nr_bits exceeds %zu", |
b1e8818c | 2198 | BITS_PER_U128); |
69b693f0 MKL |
2199 | return -EINVAL; |
2200 | } | |
2201 | ||
2202 | if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) { | |
2203 | btf_verifier_log_type(env, t, "nr_bits exceeds type_size"); | |
2204 | return -EINVAL; | |
2205 | } | |
2206 | ||
aea2f7b8 MKL |
2207 | /* |
2208 | * Only one of the encoding bits is allowed and it | |
2209 | * should be sufficient for the pretty print purpose (i.e. decoding). | |
2210 | * Multiple bits can be allowed later if it is found | |
2211 | * to be insufficient. | |
2212 | */ | |
69b693f0 MKL |
2213 | encoding = BTF_INT_ENCODING(int_data); |
2214 | if (encoding && | |
2215 | encoding != BTF_INT_SIGNED && | |
2216 | encoding != BTF_INT_CHAR && | |
aea2f7b8 | 2217 | encoding != BTF_INT_BOOL) { |
69b693f0 MKL |
2218 | btf_verifier_log_type(env, t, "Unsupported encoding"); |
2219 | return -ENOTSUPP; | |
2220 | } | |
2221 | ||
2222 | btf_verifier_log_type(env, t, NULL); | |
2223 | ||
2224 | return meta_needed; | |
2225 | } | |
2226 | ||
2227 | static void btf_int_log(struct btf_verifier_env *env, | |
2228 | const struct btf_type *t) | |
2229 | { | |
2230 | int int_data = btf_type_int(t); | |
2231 | ||
2232 | btf_verifier_log(env, | |
2233 | "size=%u bits_offset=%u nr_bits=%u encoding=%s", | |
2234 | t->size, BTF_INT_OFFSET(int_data), | |
2235 | BTF_INT_BITS(int_data), | |
2236 | btf_int_encoding_str(BTF_INT_ENCODING(int_data))); | |
2237 | } | |
2238 | ||
31d0bc81 | 2239 | static void btf_int128_print(struct btf_show *show, void *data) |
b1e8818c YS |
2240 | { |
2241 | /* data points to a __int128 number. | |
2242 | * Suppose | |
2243 | * int128_num = *(__int128 *)data; | |
2244 | * The below formulas shows what upper_num and lower_num represents: | |
2245 | * upper_num = int128_num >> 64; | |
2246 | * lower_num = int128_num & 0xffffffffFFFFFFFFULL; | |
2247 | */ | |
2248 | u64 upper_num, lower_num; | |
2249 | ||
2250 | #ifdef __BIG_ENDIAN_BITFIELD | |
2251 | upper_num = *(u64 *)data; | |
2252 | lower_num = *(u64 *)(data + 8); | |
2253 | #else | |
2254 | upper_num = *(u64 *)(data + 8); | |
2255 | lower_num = *(u64 *)data; | |
2256 | #endif | |
2257 | if (upper_num == 0) | |
31d0bc81 | 2258 | btf_show_type_value(show, "0x%llx", lower_num); |
b1e8818c | 2259 | else |
31d0bc81 AM |
2260 | btf_show_type_values(show, "0x%llx%016llx", upper_num, |
2261 | lower_num); | |
b1e8818c YS |
2262 | } |
2263 | ||
2264 | static void btf_int128_shift(u64 *print_num, u16 left_shift_bits, | |
2265 | u16 right_shift_bits) | |
2266 | { | |
2267 | u64 upper_num, lower_num; | |
2268 | ||
2269 | #ifdef __BIG_ENDIAN_BITFIELD | |
2270 | upper_num = print_num[0]; | |
2271 | lower_num = print_num[1]; | |
2272 | #else | |
2273 | upper_num = print_num[1]; | |
2274 | lower_num = print_num[0]; | |
2275 | #endif | |
2276 | ||
2277 | /* shake out un-needed bits by shift/or operations */ | |
2278 | if (left_shift_bits >= 64) { | |
2279 | upper_num = lower_num << (left_shift_bits - 64); | |
2280 | lower_num = 0; | |
2281 | } else { | |
2282 | upper_num = (upper_num << left_shift_bits) | | |
2283 | (lower_num >> (64 - left_shift_bits)); | |
2284 | lower_num = lower_num << left_shift_bits; | |
2285 | } | |
2286 | ||
2287 | if (right_shift_bits >= 64) { | |
2288 | lower_num = upper_num >> (right_shift_bits - 64); | |
2289 | upper_num = 0; | |
2290 | } else { | |
2291 | lower_num = (lower_num >> right_shift_bits) | | |
2292 | (upper_num << (64 - right_shift_bits)); | |
2293 | upper_num = upper_num >> right_shift_bits; | |
2294 | } | |
2295 | ||
2296 | #ifdef __BIG_ENDIAN_BITFIELD | |
2297 | print_num[0] = upper_num; | |
2298 | print_num[1] = lower_num; | |
2299 | #else | |
2300 | print_num[0] = lower_num; | |
2301 | print_num[1] = upper_num; | |
2302 | #endif | |
2303 | } | |
2304 | ||
31d0bc81 AM |
2305 | static void btf_bitfield_show(void *data, u8 bits_offset, |
2306 | u8 nr_bits, struct btf_show *show) | |
b00b8dae | 2307 | { |
b65f370d | 2308 | u16 left_shift_bits, right_shift_bits; |
36fc3c8c MKL |
2309 | u8 nr_copy_bytes; |
2310 | u8 nr_copy_bits; | |
b1e8818c | 2311 | u64 print_num[2] = {}; |
b00b8dae | 2312 | |
b00b8dae MKL |
2313 | nr_copy_bits = nr_bits + bits_offset; |
2314 | nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits); | |
2315 | ||
b1e8818c | 2316 | memcpy(print_num, data, nr_copy_bytes); |
b00b8dae | 2317 | |
b65f370d OK |
2318 | #ifdef __BIG_ENDIAN_BITFIELD |
2319 | left_shift_bits = bits_offset; | |
2320 | #else | |
b1e8818c | 2321 | left_shift_bits = BITS_PER_U128 - nr_copy_bits; |
b65f370d | 2322 | #endif |
b1e8818c | 2323 | right_shift_bits = BITS_PER_U128 - nr_bits; |
b00b8dae | 2324 | |
b1e8818c | 2325 | btf_int128_shift(print_num, left_shift_bits, right_shift_bits); |
31d0bc81 | 2326 | btf_int128_print(show, print_num); |
b00b8dae MKL |
2327 | } |
2328 | ||
9d5f9f70 | 2329 | |
31d0bc81 AM |
2330 | static void btf_int_bits_show(const struct btf *btf, |
2331 | const struct btf_type *t, | |
2332 | void *data, u8 bits_offset, | |
2333 | struct btf_show *show) | |
f97be3ab YS |
2334 | { |
2335 | u32 int_data = btf_type_int(t); | |
2336 | u8 nr_bits = BTF_INT_BITS(int_data); | |
2337 | u8 total_bits_offset; | |
2338 | ||
2339 | /* | |
2340 | * bits_offset is at most 7. | |
b1e8818c | 2341 | * BTF_INT_OFFSET() cannot exceed 128 bits. |
f97be3ab YS |
2342 | */ |
2343 | total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data); | |
17e3ac81 YS |
2344 | data += BITS_ROUNDDOWN_BYTES(total_bits_offset); |
2345 | bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset); | |
31d0bc81 | 2346 | btf_bitfield_show(data, bits_offset, nr_bits, show); |
f97be3ab YS |
2347 | } |
2348 | ||
31d0bc81 AM |
2349 | static void btf_int_show(const struct btf *btf, const struct btf_type *t, |
2350 | u32 type_id, void *data, u8 bits_offset, | |
2351 | struct btf_show *show) | |
b00b8dae MKL |
2352 | { |
2353 | u32 int_data = btf_type_int(t); | |
2354 | u8 encoding = BTF_INT_ENCODING(int_data); | |
2355 | bool sign = encoding & BTF_INT_SIGNED; | |
36fc3c8c | 2356 | u8 nr_bits = BTF_INT_BITS(int_data); |
31d0bc81 AM |
2357 | void *safe_data; |
2358 | ||
2359 | safe_data = btf_show_start_type(show, t, type_id, data); | |
2360 | if (!safe_data) | |
2361 | return; | |
b00b8dae MKL |
2362 | |
2363 | if (bits_offset || BTF_INT_OFFSET(int_data) || | |
2364 | BITS_PER_BYTE_MASKED(nr_bits)) { | |
31d0bc81 AM |
2365 | btf_int_bits_show(btf, t, safe_data, bits_offset, show); |
2366 | goto out; | |
b00b8dae MKL |
2367 | } |
2368 | ||
2369 | switch (nr_bits) { | |
b1e8818c | 2370 | case 128: |
31d0bc81 | 2371 | btf_int128_print(show, safe_data); |
b1e8818c | 2372 | break; |
b00b8dae MKL |
2373 | case 64: |
2374 | if (sign) | |
31d0bc81 | 2375 | btf_show_type_value(show, "%lld", *(s64 *)safe_data); |
b00b8dae | 2376 | else |
31d0bc81 | 2377 | btf_show_type_value(show, "%llu", *(u64 *)safe_data); |
b00b8dae MKL |
2378 | break; |
2379 | case 32: | |
2380 | if (sign) | |
31d0bc81 | 2381 | btf_show_type_value(show, "%d", *(s32 *)safe_data); |
b00b8dae | 2382 | else |
31d0bc81 | 2383 | btf_show_type_value(show, "%u", *(u32 *)safe_data); |
b00b8dae MKL |
2384 | break; |
2385 | case 16: | |
2386 | if (sign) | |
31d0bc81 | 2387 | btf_show_type_value(show, "%d", *(s16 *)safe_data); |
b00b8dae | 2388 | else |
31d0bc81 | 2389 | btf_show_type_value(show, "%u", *(u16 *)safe_data); |
b00b8dae MKL |
2390 | break; |
2391 | case 8: | |
31d0bc81 AM |
2392 | if (show->state.array_encoding == BTF_INT_CHAR) { |
2393 | /* check for null terminator */ | |
2394 | if (show->state.array_terminated) | |
2395 | break; | |
2396 | if (*(char *)data == '\0') { | |
2397 | show->state.array_terminated = 1; | |
2398 | break; | |
2399 | } | |
2400 | if (isprint(*(char *)data)) { | |
2401 | btf_show_type_value(show, "'%c'", | |
2402 | *(char *)safe_data); | |
2403 | break; | |
2404 | } | |
2405 | } | |
b00b8dae | 2406 | if (sign) |
31d0bc81 | 2407 | btf_show_type_value(show, "%d", *(s8 *)safe_data); |
b00b8dae | 2408 | else |
31d0bc81 | 2409 | btf_show_type_value(show, "%u", *(u8 *)safe_data); |
b00b8dae MKL |
2410 | break; |
2411 | default: | |
31d0bc81 AM |
2412 | btf_int_bits_show(btf, t, safe_data, bits_offset, show); |
2413 | break; | |
b00b8dae | 2414 | } |
31d0bc81 AM |
2415 | out: |
2416 | btf_show_end_type(show); | |
b00b8dae MKL |
2417 | } |
2418 | ||
69b693f0 MKL |
2419 | static const struct btf_kind_operations int_ops = { |
2420 | .check_meta = btf_int_check_meta, | |
eb3f595d | 2421 | .resolve = btf_df_resolve, |
179cde8c | 2422 | .check_member = btf_int_check_member, |
9d5f9f70 | 2423 | .check_kflag_member = btf_int_check_kflag_member, |
69b693f0 | 2424 | .log_details = btf_int_log, |
31d0bc81 | 2425 | .show = btf_int_show, |
69b693f0 MKL |
2426 | }; |
2427 | ||
179cde8c MKL |
2428 | static int btf_modifier_check_member(struct btf_verifier_env *env, |
2429 | const struct btf_type *struct_type, | |
2430 | const struct btf_member *member, | |
2431 | const struct btf_type *member_type) | |
2432 | { | |
2433 | const struct btf_type *resolved_type; | |
2434 | u32 resolved_type_id = member->type; | |
2435 | struct btf_member resolved_member; | |
2436 | struct btf *btf = env->btf; | |
2437 | ||
2438 | resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); | |
2439 | if (!resolved_type) { | |
2440 | btf_verifier_log_member(env, struct_type, member, | |
2441 | "Invalid member"); | |
2442 | return -EINVAL; | |
2443 | } | |
2444 | ||
2445 | resolved_member = *member; | |
2446 | resolved_member.type = resolved_type_id; | |
2447 | ||
2448 | return btf_type_ops(resolved_type)->check_member(env, struct_type, | |
2449 | &resolved_member, | |
2450 | resolved_type); | |
2451 | } | |
2452 | ||
9d5f9f70 YS |
2453 | static int btf_modifier_check_kflag_member(struct btf_verifier_env *env, |
2454 | const struct btf_type *struct_type, | |
2455 | const struct btf_member *member, | |
2456 | const struct btf_type *member_type) | |
2457 | { | |
2458 | const struct btf_type *resolved_type; | |
2459 | u32 resolved_type_id = member->type; | |
2460 | struct btf_member resolved_member; | |
2461 | struct btf *btf = env->btf; | |
2462 | ||
2463 | resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); | |
2464 | if (!resolved_type) { | |
2465 | btf_verifier_log_member(env, struct_type, member, | |
2466 | "Invalid member"); | |
2467 | return -EINVAL; | |
2468 | } | |
2469 | ||
2470 | resolved_member = *member; | |
2471 | resolved_member.type = resolved_type_id; | |
2472 | ||
2473 | return btf_type_ops(resolved_type)->check_kflag_member(env, struct_type, | |
2474 | &resolved_member, | |
2475 | resolved_type); | |
2476 | } | |
2477 | ||
179cde8c MKL |
2478 | static int btf_ptr_check_member(struct btf_verifier_env *env, |
2479 | const struct btf_type *struct_type, | |
2480 | const struct btf_member *member, | |
2481 | const struct btf_type *member_type) | |
2482 | { | |
2483 | u32 struct_size, struct_bits_off, bytes_offset; | |
2484 | ||
2485 | struct_size = struct_type->size; | |
2486 | struct_bits_off = member->offset; | |
2487 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2488 | ||
2489 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2490 | btf_verifier_log_member(env, struct_type, member, | |
2491 | "Member is not byte aligned"); | |
2492 | return -EINVAL; | |
2493 | } | |
2494 | ||
2495 | if (struct_size - bytes_offset < sizeof(void *)) { | |
2496 | btf_verifier_log_member(env, struct_type, member, | |
2497 | "Member exceeds struct_size"); | |
2498 | return -EINVAL; | |
2499 | } | |
2500 | ||
2501 | return 0; | |
2502 | } | |
2503 | ||
69b693f0 MKL |
2504 | static int btf_ref_type_check_meta(struct btf_verifier_env *env, |
2505 | const struct btf_type *t, | |
2506 | u32 meta_left) | |
2507 | { | |
8c42d2fa YS |
2508 | const char *value; |
2509 | ||
69b693f0 MKL |
2510 | if (btf_type_vlen(t)) { |
2511 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2512 | return -EINVAL; | |
2513 | } | |
2514 | ||
9d5f9f70 YS |
2515 | if (btf_type_kflag(t)) { |
2516 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2517 | return -EINVAL; | |
2518 | } | |
2519 | ||
aea2f7b8 | 2520 | if (!BTF_TYPE_ID_VALID(t->type)) { |
69b693f0 MKL |
2521 | btf_verifier_log_type(env, t, "Invalid type_id"); |
2522 | return -EINVAL; | |
2523 | } | |
2524 | ||
8c42d2fa | 2525 | /* typedef/type_tag type must have a valid name, and other ref types, |
eb04bbb6 YS |
2526 | * volatile, const, restrict, should have a null name. |
2527 | */ | |
2528 | if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) { | |
2529 | if (!t->name_off || | |
2530 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
2531 | btf_verifier_log_type(env, t, "Invalid name"); | |
2532 | return -EINVAL; | |
2533 | } | |
8c42d2fa YS |
2534 | } else if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPE_TAG) { |
2535 | value = btf_name_by_offset(env->btf, t->name_off); | |
2536 | if (!value || !value[0]) { | |
2537 | btf_verifier_log_type(env, t, "Invalid name"); | |
2538 | return -EINVAL; | |
2539 | } | |
eb04bbb6 YS |
2540 | } else { |
2541 | if (t->name_off) { | |
2542 | btf_verifier_log_type(env, t, "Invalid name"); | |
2543 | return -EINVAL; | |
2544 | } | |
2545 | } | |
2546 | ||
69b693f0 MKL |
2547 | btf_verifier_log_type(env, t, NULL); |
2548 | ||
2549 | return 0; | |
2550 | } | |
2551 | ||
eb3f595d MKL |
2552 | static int btf_modifier_resolve(struct btf_verifier_env *env, |
2553 | const struct resolve_vertex *v) | |
2554 | { | |
2555 | const struct btf_type *t = v->t; | |
2556 | const struct btf_type *next_type; | |
2557 | u32 next_type_id = t->type; | |
2558 | struct btf *btf = env->btf; | |
eb3f595d MKL |
2559 | |
2560 | next_type = btf_type_by_id(btf, next_type_id); | |
1dc92851 | 2561 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
eb3f595d MKL |
2562 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2563 | return -EINVAL; | |
2564 | } | |
2565 | ||
eb3f595d MKL |
2566 | if (!env_type_is_resolve_sink(env, next_type) && |
2567 | !env_type_is_resolved(env, next_type_id)) | |
2568 | return env_stack_push(env, next_type, next_type_id); | |
2569 | ||
2570 | /* Figure out the resolved next_type_id with size. | |
2571 | * They will be stored in the current modifier's | |
2572 | * resolved_ids and resolved_sizes such that it can | |
2573 | * save us a few type-following when we use it later (e.g. in | |
2574 | * pretty print). | |
2575 | */ | |
1acc5d5c | 2576 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
2667a262 MKL |
2577 | if (env_type_is_resolved(env, next_type_id)) |
2578 | next_type = btf_type_id_resolve(btf, &next_type_id); | |
2579 | ||
2580 | /* "typedef void new_void", "const void"...etc */ | |
2581 | if (!btf_type_is_void(next_type) && | |
81f5c6f5 YS |
2582 | !btf_type_is_fwd(next_type) && |
2583 | !btf_type_is_func_proto(next_type)) { | |
2667a262 MKL |
2584 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2585 | return -EINVAL; | |
2586 | } | |
eb3f595d MKL |
2587 | } |
2588 | ||
1acc5d5c | 2589 | env_stack_pop_resolved(env, next_type_id, 0); |
eb3f595d MKL |
2590 | |
2591 | return 0; | |
2592 | } | |
2593 | ||
1dc92851 DB |
2594 | static int btf_var_resolve(struct btf_verifier_env *env, |
2595 | const struct resolve_vertex *v) | |
2596 | { | |
2597 | const struct btf_type *next_type; | |
2598 | const struct btf_type *t = v->t; | |
2599 | u32 next_type_id = t->type; | |
2600 | struct btf *btf = env->btf; | |
1dc92851 DB |
2601 | |
2602 | next_type = btf_type_by_id(btf, next_type_id); | |
2603 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { | |
2604 | btf_verifier_log_type(env, v->t, "Invalid type_id"); | |
2605 | return -EINVAL; | |
2606 | } | |
2607 | ||
2608 | if (!env_type_is_resolve_sink(env, next_type) && | |
2609 | !env_type_is_resolved(env, next_type_id)) | |
2610 | return env_stack_push(env, next_type, next_type_id); | |
2611 | ||
2612 | if (btf_type_is_modifier(next_type)) { | |
2613 | const struct btf_type *resolved_type; | |
2614 | u32 resolved_type_id; | |
2615 | ||
2616 | resolved_type_id = next_type_id; | |
2617 | resolved_type = btf_type_id_resolve(btf, &resolved_type_id); | |
2618 | ||
2619 | if (btf_type_is_ptr(resolved_type) && | |
2620 | !env_type_is_resolve_sink(env, resolved_type) && | |
2621 | !env_type_is_resolved(env, resolved_type_id)) | |
2622 | return env_stack_push(env, resolved_type, | |
2623 | resolved_type_id); | |
2624 | } | |
2625 | ||
2626 | /* We must resolve to something concrete at this point, no | |
2627 | * forward types or similar that would resolve to size of | |
2628 | * zero is allowed. | |
2629 | */ | |
1acc5d5c | 2630 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
1dc92851 DB |
2631 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2632 | return -EINVAL; | |
2633 | } | |
2634 | ||
1acc5d5c | 2635 | env_stack_pop_resolved(env, next_type_id, 0); |
1dc92851 DB |
2636 | |
2637 | return 0; | |
2638 | } | |
2639 | ||
eb3f595d MKL |
2640 | static int btf_ptr_resolve(struct btf_verifier_env *env, |
2641 | const struct resolve_vertex *v) | |
2642 | { | |
2643 | const struct btf_type *next_type; | |
2644 | const struct btf_type *t = v->t; | |
2645 | u32 next_type_id = t->type; | |
2646 | struct btf *btf = env->btf; | |
eb3f595d MKL |
2647 | |
2648 | next_type = btf_type_by_id(btf, next_type_id); | |
1dc92851 | 2649 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
eb3f595d MKL |
2650 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2651 | return -EINVAL; | |
2652 | } | |
2653 | ||
eb3f595d MKL |
2654 | if (!env_type_is_resolve_sink(env, next_type) && |
2655 | !env_type_is_resolved(env, next_type_id)) | |
2656 | return env_stack_push(env, next_type, next_type_id); | |
2657 | ||
2658 | /* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY, | |
2659 | * the modifier may have stopped resolving when it was resolved | |
2660 | * to a ptr (last-resolved-ptr). | |
2661 | * | |
2662 | * We now need to continue from the last-resolved-ptr to | |
2663 | * ensure the last-resolved-ptr will not referring back to | |
c561d110 | 2664 | * the current ptr (t). |
eb3f595d MKL |
2665 | */ |
2666 | if (btf_type_is_modifier(next_type)) { | |
2667 | const struct btf_type *resolved_type; | |
2668 | u32 resolved_type_id; | |
2669 | ||
2670 | resolved_type_id = next_type_id; | |
2671 | resolved_type = btf_type_id_resolve(btf, &resolved_type_id); | |
2672 | ||
2673 | if (btf_type_is_ptr(resolved_type) && | |
2674 | !env_type_is_resolve_sink(env, resolved_type) && | |
2675 | !env_type_is_resolved(env, resolved_type_id)) | |
2676 | return env_stack_push(env, resolved_type, | |
2677 | resolved_type_id); | |
2678 | } | |
2679 | ||
2667a262 MKL |
2680 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
2681 | if (env_type_is_resolved(env, next_type_id)) | |
2682 | next_type = btf_type_id_resolve(btf, &next_type_id); | |
2683 | ||
2684 | if (!btf_type_is_void(next_type) && | |
2685 | !btf_type_is_fwd(next_type) && | |
2686 | !btf_type_is_func_proto(next_type)) { | |
2687 | btf_verifier_log_type(env, v->t, "Invalid type_id"); | |
2688 | return -EINVAL; | |
2689 | } | |
eb3f595d MKL |
2690 | } |
2691 | ||
eb3f595d MKL |
2692 | env_stack_pop_resolved(env, next_type_id, 0); |
2693 | ||
2694 | return 0; | |
2695 | } | |
2696 | ||
31d0bc81 AM |
2697 | static void btf_modifier_show(const struct btf *btf, |
2698 | const struct btf_type *t, | |
2699 | u32 type_id, void *data, | |
2700 | u8 bits_offset, struct btf_show *show) | |
b00b8dae | 2701 | { |
85d33df3 MKL |
2702 | if (btf->resolved_ids) |
2703 | t = btf_type_id_resolve(btf, &type_id); | |
2704 | else | |
2705 | t = btf_type_skip_modifiers(btf, type_id, NULL); | |
b00b8dae | 2706 | |
31d0bc81 | 2707 | btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show); |
b00b8dae MKL |
2708 | } |
2709 | ||
31d0bc81 AM |
2710 | static void btf_var_show(const struct btf *btf, const struct btf_type *t, |
2711 | u32 type_id, void *data, u8 bits_offset, | |
2712 | struct btf_show *show) | |
1dc92851 DB |
2713 | { |
2714 | t = btf_type_id_resolve(btf, &type_id); | |
2715 | ||
31d0bc81 | 2716 | btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show); |
1dc92851 DB |
2717 | } |
2718 | ||
31d0bc81 AM |
2719 | static void btf_ptr_show(const struct btf *btf, const struct btf_type *t, |
2720 | u32 type_id, void *data, u8 bits_offset, | |
2721 | struct btf_show *show) | |
b00b8dae | 2722 | { |
31d0bc81 AM |
2723 | void *safe_data; |
2724 | ||
2725 | safe_data = btf_show_start_type(show, t, type_id, data); | |
2726 | if (!safe_data) | |
2727 | return; | |
2728 | ||
2729 | /* It is a hashed value unless BTF_SHOW_PTR_RAW is specified */ | |
2730 | if (show->flags & BTF_SHOW_PTR_RAW) | |
2731 | btf_show_type_value(show, "0x%px", *(void **)safe_data); | |
2732 | else | |
2733 | btf_show_type_value(show, "0x%p", *(void **)safe_data); | |
2734 | btf_show_end_type(show); | |
b00b8dae MKL |
2735 | } |
2736 | ||
69b693f0 MKL |
2737 | static void btf_ref_type_log(struct btf_verifier_env *env, |
2738 | const struct btf_type *t) | |
2739 | { | |
2740 | btf_verifier_log(env, "type_id=%u", t->type); | |
2741 | } | |
2742 | ||
2743 | static struct btf_kind_operations modifier_ops = { | |
2744 | .check_meta = btf_ref_type_check_meta, | |
eb3f595d | 2745 | .resolve = btf_modifier_resolve, |
179cde8c | 2746 | .check_member = btf_modifier_check_member, |
9d5f9f70 | 2747 | .check_kflag_member = btf_modifier_check_kflag_member, |
69b693f0 | 2748 | .log_details = btf_ref_type_log, |
31d0bc81 | 2749 | .show = btf_modifier_show, |
69b693f0 MKL |
2750 | }; |
2751 | ||
2752 | static struct btf_kind_operations ptr_ops = { | |
2753 | .check_meta = btf_ref_type_check_meta, | |
eb3f595d | 2754 | .resolve = btf_ptr_resolve, |
179cde8c | 2755 | .check_member = btf_ptr_check_member, |
9d5f9f70 | 2756 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 2757 | .log_details = btf_ref_type_log, |
31d0bc81 | 2758 | .show = btf_ptr_show, |
69b693f0 MKL |
2759 | }; |
2760 | ||
8175383f MKL |
2761 | static s32 btf_fwd_check_meta(struct btf_verifier_env *env, |
2762 | const struct btf_type *t, | |
2763 | u32 meta_left) | |
2764 | { | |
2765 | if (btf_type_vlen(t)) { | |
2766 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2767 | return -EINVAL; | |
2768 | } | |
2769 | ||
2770 | if (t->type) { | |
2771 | btf_verifier_log_type(env, t, "type != 0"); | |
2772 | return -EINVAL; | |
2773 | } | |
2774 | ||
eb04bbb6 YS |
2775 | /* fwd type must have a valid name */ |
2776 | if (!t->name_off || | |
2777 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
2778 | btf_verifier_log_type(env, t, "Invalid name"); | |
2779 | return -EINVAL; | |
2780 | } | |
2781 | ||
8175383f MKL |
2782 | btf_verifier_log_type(env, t, NULL); |
2783 | ||
2784 | return 0; | |
2785 | } | |
2786 | ||
76c43ae8 YS |
2787 | static void btf_fwd_type_log(struct btf_verifier_env *env, |
2788 | const struct btf_type *t) | |
2789 | { | |
2790 | btf_verifier_log(env, "%s", btf_type_kflag(t) ? "union" : "struct"); | |
2791 | } | |
2792 | ||
69b693f0 | 2793 | static struct btf_kind_operations fwd_ops = { |
8175383f | 2794 | .check_meta = btf_fwd_check_meta, |
eb3f595d | 2795 | .resolve = btf_df_resolve, |
179cde8c | 2796 | .check_member = btf_df_check_member, |
9d5f9f70 | 2797 | .check_kflag_member = btf_df_check_kflag_member, |
76c43ae8 | 2798 | .log_details = btf_fwd_type_log, |
31d0bc81 | 2799 | .show = btf_df_show, |
69b693f0 MKL |
2800 | }; |
2801 | ||
179cde8c MKL |
2802 | static int btf_array_check_member(struct btf_verifier_env *env, |
2803 | const struct btf_type *struct_type, | |
2804 | const struct btf_member *member, | |
2805 | const struct btf_type *member_type) | |
2806 | { | |
2807 | u32 struct_bits_off = member->offset; | |
2808 | u32 struct_size, bytes_offset; | |
2809 | u32 array_type_id, array_size; | |
2810 | struct btf *btf = env->btf; | |
2811 | ||
2812 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2813 | btf_verifier_log_member(env, struct_type, member, | |
2814 | "Member is not byte aligned"); | |
2815 | return -EINVAL; | |
2816 | } | |
2817 | ||
2818 | array_type_id = member->type; | |
2819 | btf_type_id_size(btf, &array_type_id, &array_size); | |
2820 | struct_size = struct_type->size; | |
2821 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2822 | if (struct_size - bytes_offset < array_size) { | |
2823 | btf_verifier_log_member(env, struct_type, member, | |
2824 | "Member exceeds struct_size"); | |
2825 | return -EINVAL; | |
2826 | } | |
2827 | ||
2828 | return 0; | |
2829 | } | |
2830 | ||
69b693f0 MKL |
2831 | static s32 btf_array_check_meta(struct btf_verifier_env *env, |
2832 | const struct btf_type *t, | |
2833 | u32 meta_left) | |
2834 | { | |
2835 | const struct btf_array *array = btf_type_array(t); | |
2836 | u32 meta_needed = sizeof(*array); | |
2837 | ||
2838 | if (meta_left < meta_needed) { | |
2839 | btf_verifier_log_basic(env, t, | |
2840 | "meta_left:%u meta_needed:%u", | |
2841 | meta_left, meta_needed); | |
2842 | return -EINVAL; | |
2843 | } | |
2844 | ||
eb04bbb6 YS |
2845 | /* array type should not have a name */ |
2846 | if (t->name_off) { | |
2847 | btf_verifier_log_type(env, t, "Invalid name"); | |
2848 | return -EINVAL; | |
2849 | } | |
2850 | ||
69b693f0 MKL |
2851 | if (btf_type_vlen(t)) { |
2852 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2853 | return -EINVAL; | |
2854 | } | |
2855 | ||
9d5f9f70 YS |
2856 | if (btf_type_kflag(t)) { |
2857 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2858 | return -EINVAL; | |
2859 | } | |
2860 | ||
b9308ae6 MKL |
2861 | if (t->size) { |
2862 | btf_verifier_log_type(env, t, "size != 0"); | |
2863 | return -EINVAL; | |
2864 | } | |
2865 | ||
4ef5f574 MKL |
2866 | /* Array elem type and index type cannot be in type void, |
2867 | * so !array->type and !array->index_type are not allowed. | |
69b693f0 | 2868 | */ |
aea2f7b8 | 2869 | if (!array->type || !BTF_TYPE_ID_VALID(array->type)) { |
4ef5f574 MKL |
2870 | btf_verifier_log_type(env, t, "Invalid elem"); |
2871 | return -EINVAL; | |
2872 | } | |
2873 | ||
aea2f7b8 | 2874 | if (!array->index_type || !BTF_TYPE_ID_VALID(array->index_type)) { |
4ef5f574 | 2875 | btf_verifier_log_type(env, t, "Invalid index"); |
69b693f0 MKL |
2876 | return -EINVAL; |
2877 | } | |
2878 | ||
2879 | btf_verifier_log_type(env, t, NULL); | |
2880 | ||
2881 | return meta_needed; | |
2882 | } | |
2883 | ||
eb3f595d MKL |
2884 | static int btf_array_resolve(struct btf_verifier_env *env, |
2885 | const struct resolve_vertex *v) | |
2886 | { | |
2887 | const struct btf_array *array = btf_type_array(v->t); | |
4ef5f574 MKL |
2888 | const struct btf_type *elem_type, *index_type; |
2889 | u32 elem_type_id, index_type_id; | |
eb3f595d MKL |
2890 | struct btf *btf = env->btf; |
2891 | u32 elem_size; | |
2892 | ||
4ef5f574 MKL |
2893 | /* Check array->index_type */ |
2894 | index_type_id = array->index_type; | |
2895 | index_type = btf_type_by_id(btf, index_type_id); | |
e4f07120 SF |
2896 | if (btf_type_nosize_or_null(index_type) || |
2897 | btf_type_is_resolve_source_only(index_type)) { | |
4ef5f574 MKL |
2898 | btf_verifier_log_type(env, v->t, "Invalid index"); |
2899 | return -EINVAL; | |
2900 | } | |
2901 | ||
2902 | if (!env_type_is_resolve_sink(env, index_type) && | |
2903 | !env_type_is_resolved(env, index_type_id)) | |
2904 | return env_stack_push(env, index_type, index_type_id); | |
2905 | ||
2906 | index_type = btf_type_id_size(btf, &index_type_id, NULL); | |
2907 | if (!index_type || !btf_type_is_int(index_type) || | |
2908 | !btf_type_int_is_regular(index_type)) { | |
2909 | btf_verifier_log_type(env, v->t, "Invalid index"); | |
2910 | return -EINVAL; | |
2911 | } | |
2912 | ||
2913 | /* Check array->type */ | |
2914 | elem_type_id = array->type; | |
eb3f595d | 2915 | elem_type = btf_type_by_id(btf, elem_type_id); |
e4f07120 SF |
2916 | if (btf_type_nosize_or_null(elem_type) || |
2917 | btf_type_is_resolve_source_only(elem_type)) { | |
eb3f595d MKL |
2918 | btf_verifier_log_type(env, v->t, |
2919 | "Invalid elem"); | |
2920 | return -EINVAL; | |
2921 | } | |
2922 | ||
2923 | if (!env_type_is_resolve_sink(env, elem_type) && | |
2924 | !env_type_is_resolved(env, elem_type_id)) | |
2925 | return env_stack_push(env, elem_type, elem_type_id); | |
2926 | ||
2927 | elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); | |
2928 | if (!elem_type) { | |
2929 | btf_verifier_log_type(env, v->t, "Invalid elem"); | |
2930 | return -EINVAL; | |
2931 | } | |
2932 | ||
4ef5f574 MKL |
2933 | if (btf_type_is_int(elem_type) && !btf_type_int_is_regular(elem_type)) { |
2934 | btf_verifier_log_type(env, v->t, "Invalid array of int"); | |
2935 | return -EINVAL; | |
eb3f595d MKL |
2936 | } |
2937 | ||
2938 | if (array->nelems && elem_size > U32_MAX / array->nelems) { | |
2939 | btf_verifier_log_type(env, v->t, | |
2940 | "Array size overflows U32_MAX"); | |
2941 | return -EINVAL; | |
2942 | } | |
2943 | ||
2944 | env_stack_pop_resolved(env, elem_type_id, elem_size * array->nelems); | |
2945 | ||
2946 | return 0; | |
2947 | } | |
2948 | ||
69b693f0 MKL |
2949 | static void btf_array_log(struct btf_verifier_env *env, |
2950 | const struct btf_type *t) | |
2951 | { | |
2952 | const struct btf_array *array = btf_type_array(t); | |
2953 | ||
2954 | btf_verifier_log(env, "type_id=%u index_type_id=%u nr_elems=%u", | |
2955 | array->type, array->index_type, array->nelems); | |
2956 | } | |
2957 | ||
31d0bc81 AM |
2958 | static void __btf_array_show(const struct btf *btf, const struct btf_type *t, |
2959 | u32 type_id, void *data, u8 bits_offset, | |
2960 | struct btf_show *show) | |
b00b8dae MKL |
2961 | { |
2962 | const struct btf_array *array = btf_type_array(t); | |
2963 | const struct btf_kind_operations *elem_ops; | |
2964 | const struct btf_type *elem_type; | |
31d0bc81 AM |
2965 | u32 i, elem_size = 0, elem_type_id; |
2966 | u16 encoding = 0; | |
b00b8dae MKL |
2967 | |
2968 | elem_type_id = array->type; | |
31d0bc81 AM |
2969 | elem_type = btf_type_skip_modifiers(btf, elem_type_id, NULL); |
2970 | if (elem_type && btf_type_has_size(elem_type)) | |
2971 | elem_size = elem_type->size; | |
2972 | ||
2973 | if (elem_type && btf_type_is_int(elem_type)) { | |
2974 | u32 int_type = btf_type_int(elem_type); | |
2975 | ||
2976 | encoding = BTF_INT_ENCODING(int_type); | |
2977 | ||
2978 | /* | |
2979 | * BTF_INT_CHAR encoding never seems to be set for | |
2980 | * char arrays, so if size is 1 and element is | |
2981 | * printable as a char, we'll do that. | |
2982 | */ | |
2983 | if (elem_size == 1) | |
2984 | encoding = BTF_INT_CHAR; | |
2985 | } | |
2986 | ||
2987 | if (!btf_show_start_array_type(show, t, type_id, encoding, data)) | |
2988 | return; | |
2989 | ||
2990 | if (!elem_type) | |
2991 | goto out; | |
b00b8dae | 2992 | elem_ops = btf_type_ops(elem_type); |
31d0bc81 | 2993 | |
b00b8dae | 2994 | for (i = 0; i < array->nelems; i++) { |
b00b8dae | 2995 | |
31d0bc81 AM |
2996 | btf_show_start_array_member(show); |
2997 | ||
2998 | elem_ops->show(btf, elem_type, elem_type_id, data, | |
2999 | bits_offset, show); | |
b00b8dae | 3000 | data += elem_size; |
31d0bc81 AM |
3001 | |
3002 | btf_show_end_array_member(show); | |
3003 | ||
3004 | if (show->state.array_terminated) | |
3005 | break; | |
b00b8dae | 3006 | } |
31d0bc81 AM |
3007 | out: |
3008 | btf_show_end_array_type(show); | |
3009 | } | |
3010 | ||
3011 | static void btf_array_show(const struct btf *btf, const struct btf_type *t, | |
3012 | u32 type_id, void *data, u8 bits_offset, | |
3013 | struct btf_show *show) | |
3014 | { | |
3015 | const struct btf_member *m = show->state.member; | |
3016 | ||
3017 | /* | |
3018 | * First check if any members would be shown (are non-zero). | |
3019 | * See comments above "struct btf_show" definition for more | |
3020 | * details on how this works at a high-level. | |
3021 | */ | |
3022 | if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) { | |
3023 | if (!show->state.depth_check) { | |
3024 | show->state.depth_check = show->state.depth + 1; | |
3025 | show->state.depth_to_show = 0; | |
3026 | } | |
3027 | __btf_array_show(btf, t, type_id, data, bits_offset, show); | |
3028 | show->state.member = m; | |
3029 | ||
3030 | if (show->state.depth_check != show->state.depth + 1) | |
3031 | return; | |
3032 | show->state.depth_check = 0; | |
3033 | ||
3034 | if (show->state.depth_to_show <= show->state.depth) | |
3035 | return; | |
3036 | /* | |
3037 | * Reaching here indicates we have recursed and found | |
3038 | * non-zero array member(s). | |
3039 | */ | |
3040 | } | |
3041 | __btf_array_show(btf, t, type_id, data, bits_offset, show); | |
b00b8dae MKL |
3042 | } |
3043 | ||
69b693f0 MKL |
3044 | static struct btf_kind_operations array_ops = { |
3045 | .check_meta = btf_array_check_meta, | |
eb3f595d | 3046 | .resolve = btf_array_resolve, |
179cde8c | 3047 | .check_member = btf_array_check_member, |
9d5f9f70 | 3048 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 3049 | .log_details = btf_array_log, |
31d0bc81 | 3050 | .show = btf_array_show, |
69b693f0 MKL |
3051 | }; |
3052 | ||
179cde8c MKL |
3053 | static int btf_struct_check_member(struct btf_verifier_env *env, |
3054 | const struct btf_type *struct_type, | |
3055 | const struct btf_member *member, | |
3056 | const struct btf_type *member_type) | |
3057 | { | |
3058 | u32 struct_bits_off = member->offset; | |
3059 | u32 struct_size, bytes_offset; | |
3060 | ||
3061 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
3062 | btf_verifier_log_member(env, struct_type, member, | |
3063 | "Member is not byte aligned"); | |
3064 | return -EINVAL; | |
3065 | } | |
3066 | ||
3067 | struct_size = struct_type->size; | |
3068 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
3069 | if (struct_size - bytes_offset < member_type->size) { | |
3070 | btf_verifier_log_member(env, struct_type, member, | |
3071 | "Member exceeds struct_size"); | |
3072 | return -EINVAL; | |
3073 | } | |
3074 | ||
3075 | return 0; | |
3076 | } | |
3077 | ||
69b693f0 MKL |
3078 | static s32 btf_struct_check_meta(struct btf_verifier_env *env, |
3079 | const struct btf_type *t, | |
3080 | u32 meta_left) | |
3081 | { | |
3082 | bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION; | |
3083 | const struct btf_member *member; | |
6283fa38 | 3084 | u32 meta_needed, last_offset; |
69b693f0 MKL |
3085 | struct btf *btf = env->btf; |
3086 | u32 struct_size = t->size; | |
9d5f9f70 | 3087 | u32 offset; |
69b693f0 MKL |
3088 | u16 i; |
3089 | ||
3090 | meta_needed = btf_type_vlen(t) * sizeof(*member); | |
3091 | if (meta_left < meta_needed) { | |
3092 | btf_verifier_log_basic(env, t, | |
3093 | "meta_left:%u meta_needed:%u", | |
3094 | meta_left, meta_needed); | |
3095 | return -EINVAL; | |
3096 | } | |
3097 | ||
eb04bbb6 YS |
3098 | /* struct type either no name or a valid one */ |
3099 | if (t->name_off && | |
3100 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
3101 | btf_verifier_log_type(env, t, "Invalid name"); | |
3102 | return -EINVAL; | |
3103 | } | |
3104 | ||
69b693f0 MKL |
3105 | btf_verifier_log_type(env, t, NULL); |
3106 | ||
6283fa38 | 3107 | last_offset = 0; |
69b693f0 | 3108 | for_each_member(i, t, member) { |
fbcf93eb | 3109 | if (!btf_name_offset_valid(btf, member->name_off)) { |
69b693f0 MKL |
3110 | btf_verifier_log_member(env, t, member, |
3111 | "Invalid member name_offset:%u", | |
fbcf93eb | 3112 | member->name_off); |
69b693f0 MKL |
3113 | return -EINVAL; |
3114 | } | |
3115 | ||
eb04bbb6 YS |
3116 | /* struct member either no name or a valid one */ |
3117 | if (member->name_off && | |
3118 | !btf_name_valid_identifier(btf, member->name_off)) { | |
3119 | btf_verifier_log_member(env, t, member, "Invalid name"); | |
3120 | return -EINVAL; | |
3121 | } | |
69b693f0 | 3122 | /* A member cannot be in type void */ |
aea2f7b8 | 3123 | if (!member->type || !BTF_TYPE_ID_VALID(member->type)) { |
69b693f0 MKL |
3124 | btf_verifier_log_member(env, t, member, |
3125 | "Invalid type_id"); | |
3126 | return -EINVAL; | |
3127 | } | |
3128 | ||
8293eb99 | 3129 | offset = __btf_member_bit_offset(t, member); |
9d5f9f70 | 3130 | if (is_union && offset) { |
69b693f0 MKL |
3131 | btf_verifier_log_member(env, t, member, |
3132 | "Invalid member bits_offset"); | |
3133 | return -EINVAL; | |
3134 | } | |
3135 | ||
6283fa38 MKL |
3136 | /* |
3137 | * ">" instead of ">=" because the last member could be | |
3138 | * "char a[0];" | |
3139 | */ | |
9d5f9f70 | 3140 | if (last_offset > offset) { |
6283fa38 MKL |
3141 | btf_verifier_log_member(env, t, member, |
3142 | "Invalid member bits_offset"); | |
3143 | return -EINVAL; | |
3144 | } | |
3145 | ||
9d5f9f70 | 3146 | if (BITS_ROUNDUP_BYTES(offset) > struct_size) { |
69b693f0 | 3147 | btf_verifier_log_member(env, t, member, |
311fe1a8 | 3148 | "Member bits_offset exceeds its struct size"); |
69b693f0 MKL |
3149 | return -EINVAL; |
3150 | } | |
3151 | ||
3152 | btf_verifier_log_member(env, t, member, NULL); | |
9d5f9f70 | 3153 | last_offset = offset; |
69b693f0 MKL |
3154 | } |
3155 | ||
3156 | return meta_needed; | |
3157 | } | |
3158 | ||
eb3f595d MKL |
3159 | static int btf_struct_resolve(struct btf_verifier_env *env, |
3160 | const struct resolve_vertex *v) | |
3161 | { | |
3162 | const struct btf_member *member; | |
179cde8c | 3163 | int err; |
eb3f595d MKL |
3164 | u16 i; |
3165 | ||
3166 | /* Before continue resolving the next_member, | |
3167 | * ensure the last member is indeed resolved to a | |
3168 | * type with size info. | |
3169 | */ | |
3170 | if (v->next_member) { | |
179cde8c | 3171 | const struct btf_type *last_member_type; |
eb3f595d | 3172 | const struct btf_member *last_member; |
a37a3258 | 3173 | u32 last_member_type_id; |
eb3f595d MKL |
3174 | |
3175 | last_member = btf_type_member(v->t) + v->next_member - 1; | |
3176 | last_member_type_id = last_member->type; | |
3177 | if (WARN_ON_ONCE(!env_type_is_resolved(env, | |
3178 | last_member_type_id))) | |
3179 | return -EINVAL; | |
179cde8c MKL |
3180 | |
3181 | last_member_type = btf_type_by_id(env->btf, | |
3182 | last_member_type_id); | |
9d5f9f70 YS |
3183 | if (btf_type_kflag(v->t)) |
3184 | err = btf_type_ops(last_member_type)->check_kflag_member(env, v->t, | |
3185 | last_member, | |
3186 | last_member_type); | |
3187 | else | |
3188 | err = btf_type_ops(last_member_type)->check_member(env, v->t, | |
3189 | last_member, | |
3190 | last_member_type); | |
179cde8c MKL |
3191 | if (err) |
3192 | return err; | |
eb3f595d MKL |
3193 | } |
3194 | ||
3195 | for_each_member_from(i, v->next_member, v->t, member) { | |
3196 | u32 member_type_id = member->type; | |
3197 | const struct btf_type *member_type = btf_type_by_id(env->btf, | |
3198 | member_type_id); | |
3199 | ||
e4f07120 SF |
3200 | if (btf_type_nosize_or_null(member_type) || |
3201 | btf_type_is_resolve_source_only(member_type)) { | |
eb3f595d MKL |
3202 | btf_verifier_log_member(env, v->t, member, |
3203 | "Invalid member"); | |
3204 | return -EINVAL; | |
3205 | } | |
3206 | ||
3207 | if (!env_type_is_resolve_sink(env, member_type) && | |
3208 | !env_type_is_resolved(env, member_type_id)) { | |
3209 | env_stack_set_next_member(env, i + 1); | |
3210 | return env_stack_push(env, member_type, member_type_id); | |
3211 | } | |
179cde8c | 3212 | |
9d5f9f70 YS |
3213 | if (btf_type_kflag(v->t)) |
3214 | err = btf_type_ops(member_type)->check_kflag_member(env, v->t, | |
3215 | member, | |
3216 | member_type); | |
3217 | else | |
3218 | err = btf_type_ops(member_type)->check_member(env, v->t, | |
3219 | member, | |
3220 | member_type); | |
179cde8c MKL |
3221 | if (err) |
3222 | return err; | |
eb3f595d MKL |
3223 | } |
3224 | ||
3225 | env_stack_pop_resolved(env, 0, 0); | |
3226 | ||
3227 | return 0; | |
3228 | } | |
3229 | ||
69b693f0 MKL |
3230 | static void btf_struct_log(struct btf_verifier_env *env, |
3231 | const struct btf_type *t) | |
3232 | { | |
3233 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
3234 | } | |
3235 | ||
61df10c7 KKD |
3236 | enum { |
3237 | BTF_FIELD_IGNORE = 0, | |
3238 | BTF_FIELD_FOUND = 1, | |
42ba1308 KKD |
3239 | }; |
3240 | ||
3241 | struct btf_field_info { | |
aa3496ac | 3242 | enum btf_field_type type; |
42ba1308 | 3243 | u32 off; |
f0c5941f KKD |
3244 | union { |
3245 | struct { | |
3246 | u32 type_id; | |
3247 | } kptr; | |
3248 | struct { | |
3249 | const char *node_name; | |
3250 | u32 value_btf_id; | |
30465003 | 3251 | } graph_root; |
f0c5941f | 3252 | }; |
42ba1308 KKD |
3253 | }; |
3254 | ||
3255 | static int btf_find_struct(const struct btf *btf, const struct btf_type *t, | |
db559117 KKD |
3256 | u32 off, int sz, enum btf_field_type field_type, |
3257 | struct btf_field_info *info) | |
42ba1308 KKD |
3258 | { |
3259 | if (!__btf_type_is_struct(t)) | |
61df10c7 | 3260 | return BTF_FIELD_IGNORE; |
42ba1308 | 3261 | if (t->size != sz) |
61df10c7 | 3262 | return BTF_FIELD_IGNORE; |
db559117 | 3263 | info->type = field_type; |
42ba1308 | 3264 | info->off = off; |
61df10c7 KKD |
3265 | return BTF_FIELD_FOUND; |
3266 | } | |
3267 | ||
3268 | static int btf_find_kptr(const struct btf *btf, const struct btf_type *t, | |
3269 | u32 off, int sz, struct btf_field_info *info) | |
3270 | { | |
aa3496ac | 3271 | enum btf_field_type type; |
61df10c7 KKD |
3272 | u32 res_id; |
3273 | ||
23da464d KKD |
3274 | /* Permit modifiers on the pointer itself */ |
3275 | if (btf_type_is_volatile(t)) | |
3276 | t = btf_type_by_id(btf, t->type); | |
61df10c7 KKD |
3277 | /* For PTR, sz is always == 8 */ |
3278 | if (!btf_type_is_ptr(t)) | |
3279 | return BTF_FIELD_IGNORE; | |
3280 | t = btf_type_by_id(btf, t->type); | |
3281 | ||
3282 | if (!btf_type_is_type_tag(t)) | |
3283 | return BTF_FIELD_IGNORE; | |
3284 | /* Reject extra tags */ | |
3285 | if (btf_type_is_type_tag(btf_type_by_id(btf, t->type))) | |
3286 | return -EINVAL; | |
03b77e17 | 3287 | if (!strcmp("kptr_untrusted", __btf_name_by_offset(btf, t->name_off))) |
c0a5a21c | 3288 | type = BPF_KPTR_UNREF; |
03b77e17 | 3289 | else if (!strcmp("kptr", __btf_name_by_offset(btf, t->name_off))) |
c0a5a21c KKD |
3290 | type = BPF_KPTR_REF; |
3291 | else | |
61df10c7 KKD |
3292 | return -EINVAL; |
3293 | ||
3294 | /* Get the base type */ | |
3295 | t = btf_type_skip_modifiers(btf, t->type, &res_id); | |
3296 | /* Only pointer to struct is allowed */ | |
3297 | if (!__btf_type_is_struct(t)) | |
3298 | return -EINVAL; | |
3299 | ||
c0a5a21c | 3300 | info->type = type; |
db559117 KKD |
3301 | info->off = off; |
3302 | info->kptr.type_id = res_id; | |
61df10c7 | 3303 | return BTF_FIELD_FOUND; |
42ba1308 KKD |
3304 | } |
3305 | ||
f0c5941f KKD |
3306 | static const char *btf_find_decl_tag_value(const struct btf *btf, |
3307 | const struct btf_type *pt, | |
3308 | int comp_idx, const char *tag_key) | |
3309 | { | |
3310 | int i; | |
3311 | ||
3312 | for (i = 1; i < btf_nr_types(btf); i++) { | |
3313 | const struct btf_type *t = btf_type_by_id(btf, i); | |
3314 | int len = strlen(tag_key); | |
3315 | ||
3316 | if (!btf_type_is_decl_tag(t)) | |
3317 | continue; | |
3318 | if (pt != btf_type_by_id(btf, t->type) || | |
3319 | btf_type_decl_tag(t)->component_idx != comp_idx) | |
3320 | continue; | |
3321 | if (strncmp(__btf_name_by_offset(btf, t->name_off), tag_key, len)) | |
3322 | continue; | |
3323 | return __btf_name_by_offset(btf, t->name_off) + len; | |
3324 | } | |
3325 | return NULL; | |
3326 | } | |
3327 | ||
9c395c1b DM |
3328 | static int |
3329 | btf_find_graph_root(const struct btf *btf, const struct btf_type *pt, | |
3330 | const struct btf_type *t, int comp_idx, u32 off, | |
3331 | int sz, struct btf_field_info *info, | |
3332 | enum btf_field_type head_type) | |
f0c5941f | 3333 | { |
9c395c1b | 3334 | const char *node_field_name; |
f0c5941f | 3335 | const char *value_type; |
f0c5941f KKD |
3336 | s32 id; |
3337 | ||
3338 | if (!__btf_type_is_struct(t)) | |
3339 | return BTF_FIELD_IGNORE; | |
3340 | if (t->size != sz) | |
3341 | return BTF_FIELD_IGNORE; | |
3342 | value_type = btf_find_decl_tag_value(btf, pt, comp_idx, "contains:"); | |
3343 | if (!value_type) | |
3344 | return -EINVAL; | |
9c395c1b DM |
3345 | node_field_name = strstr(value_type, ":"); |
3346 | if (!node_field_name) | |
f0c5941f | 3347 | return -EINVAL; |
9c395c1b | 3348 | value_type = kstrndup(value_type, node_field_name - value_type, GFP_KERNEL | __GFP_NOWARN); |
f0c5941f KKD |
3349 | if (!value_type) |
3350 | return -ENOMEM; | |
3351 | id = btf_find_by_name_kind(btf, value_type, BTF_KIND_STRUCT); | |
3352 | kfree(value_type); | |
3353 | if (id < 0) | |
3354 | return id; | |
9c395c1b DM |
3355 | node_field_name++; |
3356 | if (str_is_empty(node_field_name)) | |
f0c5941f | 3357 | return -EINVAL; |
9c395c1b | 3358 | info->type = head_type; |
f0c5941f | 3359 | info->off = off; |
30465003 | 3360 | info->graph_root.value_btf_id = id; |
9c395c1b | 3361 | info->graph_root.node_name = node_field_name; |
f0c5941f KKD |
3362 | return BTF_FIELD_FOUND; |
3363 | } | |
3364 | ||
9c395c1b DM |
3365 | #define field_mask_test_name(field_type, field_type_str) \ |
3366 | if (field_mask & field_type && !strcmp(name, field_type_str)) { \ | |
3367 | type = field_type; \ | |
3368 | goto end; \ | |
3369 | } | |
3370 | ||
db559117 KKD |
3371 | static int btf_get_field_type(const char *name, u32 field_mask, u32 *seen_mask, |
3372 | int *align, int *sz) | |
3373 | { | |
3374 | int type = 0; | |
3375 | ||
3376 | if (field_mask & BPF_SPIN_LOCK) { | |
3377 | if (!strcmp(name, "bpf_spin_lock")) { | |
3378 | if (*seen_mask & BPF_SPIN_LOCK) | |
3379 | return -E2BIG; | |
3380 | *seen_mask |= BPF_SPIN_LOCK; | |
3381 | type = BPF_SPIN_LOCK; | |
3382 | goto end; | |
3383 | } | |
3384 | } | |
3385 | if (field_mask & BPF_TIMER) { | |
3386 | if (!strcmp(name, "bpf_timer")) { | |
3387 | if (*seen_mask & BPF_TIMER) | |
3388 | return -E2BIG; | |
3389 | *seen_mask |= BPF_TIMER; | |
3390 | type = BPF_TIMER; | |
3391 | goto end; | |
3392 | } | |
3393 | } | |
9c395c1b DM |
3394 | field_mask_test_name(BPF_LIST_HEAD, "bpf_list_head"); |
3395 | field_mask_test_name(BPF_LIST_NODE, "bpf_list_node"); | |
3396 | field_mask_test_name(BPF_RB_ROOT, "bpf_rb_root"); | |
3397 | field_mask_test_name(BPF_RB_NODE, "bpf_rb_node"); | |
d54730b5 | 3398 | field_mask_test_name(BPF_REFCOUNT, "bpf_refcount"); |
9c395c1b | 3399 | |
db559117 KKD |
3400 | /* Only return BPF_KPTR when all other types with matchable names fail */ |
3401 | if (field_mask & BPF_KPTR) { | |
3402 | type = BPF_KPTR_REF; | |
3403 | goto end; | |
3404 | } | |
3405 | return 0; | |
3406 | end: | |
3407 | *sz = btf_field_type_size(type); | |
3408 | *align = btf_field_type_align(type); | |
3409 | return type; | |
3410 | } | |
3411 | ||
9c395c1b DM |
3412 | #undef field_mask_test_name |
3413 | ||
db559117 KKD |
3414 | static int btf_find_struct_field(const struct btf *btf, |
3415 | const struct btf_type *t, u32 field_mask, | |
61df10c7 | 3416 | struct btf_field_info *info, int info_cnt) |
d83525ca | 3417 | { |
db559117 | 3418 | int ret, idx = 0, align, sz, field_type; |
d83525ca | 3419 | const struct btf_member *member; |
61df10c7 | 3420 | struct btf_field_info tmp; |
db559117 | 3421 | u32 i, off, seen_mask = 0; |
d83525ca | 3422 | |
d83525ca AS |
3423 | for_each_member(i, t, member) { |
3424 | const struct btf_type *member_type = btf_type_by_id(btf, | |
3425 | member->type); | |
42ba1308 | 3426 | |
db559117 KKD |
3427 | field_type = btf_get_field_type(__btf_name_by_offset(btf, member_type->name_off), |
3428 | field_mask, &seen_mask, &align, &sz); | |
3429 | if (field_type == 0) | |
d83525ca | 3430 | continue; |
db559117 KKD |
3431 | if (field_type < 0) |
3432 | return field_type; | |
42ba1308 | 3433 | |
8293eb99 | 3434 | off = __btf_member_bit_offset(t, member); |
d83525ca AS |
3435 | if (off % 8) |
3436 | /* valid C code cannot generate such BTF */ | |
3437 | return -EINVAL; | |
3438 | off /= 8; | |
68134668 | 3439 | if (off % align) |
db559117 | 3440 | continue; |
42ba1308 KKD |
3441 | |
3442 | switch (field_type) { | |
db559117 KKD |
3443 | case BPF_SPIN_LOCK: |
3444 | case BPF_TIMER: | |
8ffa5cc1 | 3445 | case BPF_LIST_NODE: |
9c395c1b | 3446 | case BPF_RB_NODE: |
d54730b5 | 3447 | case BPF_REFCOUNT: |
db559117 | 3448 | ret = btf_find_struct(btf, member_type, off, sz, field_type, |
61df10c7 KKD |
3449 | idx < info_cnt ? &info[idx] : &tmp); |
3450 | if (ret < 0) | |
3451 | return ret; | |
3452 | break; | |
db559117 KKD |
3453 | case BPF_KPTR_UNREF: |
3454 | case BPF_KPTR_REF: | |
61df10c7 KKD |
3455 | ret = btf_find_kptr(btf, member_type, off, sz, |
3456 | idx < info_cnt ? &info[idx] : &tmp); | |
3457 | if (ret < 0) | |
3458 | return ret; | |
3459 | break; | |
f0c5941f | 3460 | case BPF_LIST_HEAD: |
9c395c1b DM |
3461 | case BPF_RB_ROOT: |
3462 | ret = btf_find_graph_root(btf, t, member_type, | |
3463 | i, off, sz, | |
3464 | idx < info_cnt ? &info[idx] : &tmp, | |
3465 | field_type); | |
f0c5941f KKD |
3466 | if (ret < 0) |
3467 | return ret; | |
3468 | break; | |
42ba1308 KKD |
3469 | default: |
3470 | return -EFAULT; | |
3471 | } | |
61df10c7 KKD |
3472 | |
3473 | if (ret == BTF_FIELD_IGNORE) | |
3474 | continue; | |
3475 | if (idx >= info_cnt) | |
3476 | return -E2BIG; | |
3477 | ++idx; | |
68134668 | 3478 | } |
61df10c7 | 3479 | return idx; |
68134668 AS |
3480 | } |
3481 | ||
3482 | static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t, | |
db559117 KKD |
3483 | u32 field_mask, struct btf_field_info *info, |
3484 | int info_cnt) | |
68134668 | 3485 | { |
db559117 | 3486 | int ret, idx = 0, align, sz, field_type; |
68134668 | 3487 | const struct btf_var_secinfo *vsi; |
61df10c7 | 3488 | struct btf_field_info tmp; |
db559117 | 3489 | u32 i, off, seen_mask = 0; |
68134668 AS |
3490 | |
3491 | for_each_vsi(i, t, vsi) { | |
3492 | const struct btf_type *var = btf_type_by_id(btf, vsi->type); | |
3493 | const struct btf_type *var_type = btf_type_by_id(btf, var->type); | |
3494 | ||
db559117 KKD |
3495 | field_type = btf_get_field_type(__btf_name_by_offset(btf, var_type->name_off), |
3496 | field_mask, &seen_mask, &align, &sz); | |
3497 | if (field_type == 0) | |
68134668 | 3498 | continue; |
db559117 KKD |
3499 | if (field_type < 0) |
3500 | return field_type; | |
3501 | ||
3502 | off = vsi->offset; | |
68134668 AS |
3503 | if (vsi->size != sz) |
3504 | continue; | |
68134668 | 3505 | if (off % align) |
db559117 | 3506 | continue; |
42ba1308 KKD |
3507 | |
3508 | switch (field_type) { | |
db559117 KKD |
3509 | case BPF_SPIN_LOCK: |
3510 | case BPF_TIMER: | |
8ffa5cc1 | 3511 | case BPF_LIST_NODE: |
9c395c1b | 3512 | case BPF_RB_NODE: |
d54730b5 | 3513 | case BPF_REFCOUNT: |
db559117 | 3514 | ret = btf_find_struct(btf, var_type, off, sz, field_type, |
61df10c7 KKD |
3515 | idx < info_cnt ? &info[idx] : &tmp); |
3516 | if (ret < 0) | |
3517 | return ret; | |
3518 | break; | |
db559117 KKD |
3519 | case BPF_KPTR_UNREF: |
3520 | case BPF_KPTR_REF: | |
61df10c7 KKD |
3521 | ret = btf_find_kptr(btf, var_type, off, sz, |
3522 | idx < info_cnt ? &info[idx] : &tmp); | |
3523 | if (ret < 0) | |
3524 | return ret; | |
3525 | break; | |
f0c5941f | 3526 | case BPF_LIST_HEAD: |
9c395c1b DM |
3527 | case BPF_RB_ROOT: |
3528 | ret = btf_find_graph_root(btf, var, var_type, | |
3529 | -1, off, sz, | |
3530 | idx < info_cnt ? &info[idx] : &tmp, | |
3531 | field_type); | |
f0c5941f KKD |
3532 | if (ret < 0) |
3533 | return ret; | |
3534 | break; | |
42ba1308 KKD |
3535 | default: |
3536 | return -EFAULT; | |
3537 | } | |
61df10c7 KKD |
3538 | |
3539 | if (ret == BTF_FIELD_IGNORE) | |
3540 | continue; | |
3541 | if (idx >= info_cnt) | |
3542 | return -E2BIG; | |
3543 | ++idx; | |
d83525ca | 3544 | } |
61df10c7 | 3545 | return idx; |
d83525ca AS |
3546 | } |
3547 | ||
68134668 | 3548 | static int btf_find_field(const struct btf *btf, const struct btf_type *t, |
db559117 KKD |
3549 | u32 field_mask, struct btf_field_info *info, |
3550 | int info_cnt) | |
68134668 | 3551 | { |
68134668 | 3552 | if (__btf_type_is_struct(t)) |
db559117 | 3553 | return btf_find_struct_field(btf, t, field_mask, info, info_cnt); |
68134668 | 3554 | else if (btf_type_is_datasec(t)) |
db559117 | 3555 | return btf_find_datasec_var(btf, t, field_mask, info, info_cnt); |
68134668 AS |
3556 | return -EINVAL; |
3557 | } | |
3558 | ||
db559117 KKD |
3559 | static int btf_parse_kptr(const struct btf *btf, struct btf_field *field, |
3560 | struct btf_field_info *info) | |
68134668 | 3561 | { |
db559117 KKD |
3562 | struct module *mod = NULL; |
3563 | const struct btf_type *t; | |
c8e18754 DM |
3564 | /* If a matching btf type is found in kernel or module BTFs, kptr_ref |
3565 | * is that BTF, otherwise it's program BTF | |
3566 | */ | |
3567 | struct btf *kptr_btf; | |
42ba1308 | 3568 | int ret; |
db559117 | 3569 | s32 id; |
42ba1308 | 3570 | |
db559117 KKD |
3571 | /* Find type in map BTF, and use it to look up the matching type |
3572 | * in vmlinux or module BTFs, by name and kind. | |
3573 | */ | |
3574 | t = btf_type_by_id(btf, info->kptr.type_id); | |
3575 | id = bpf_find_btf_id(__btf_name_by_offset(btf, t->name_off), BTF_INFO_KIND(t->info), | |
c8e18754 DM |
3576 | &kptr_btf); |
3577 | if (id == -ENOENT) { | |
3578 | /* btf_parse_kptr should only be called w/ btf = program BTF */ | |
3579 | WARN_ON_ONCE(btf_is_kernel(btf)); | |
3580 | ||
3581 | /* Type exists only in program BTF. Assume that it's a MEM_ALLOC | |
3582 | * kptr allocated via bpf_obj_new | |
3583 | */ | |
9e36a204 | 3584 | field->kptr.dtor = NULL; |
c8e18754 DM |
3585 | id = info->kptr.type_id; |
3586 | kptr_btf = (struct btf *)btf; | |
3587 | btf_get(kptr_btf); | |
3588 | goto found_dtor; | |
3589 | } | |
db559117 KKD |
3590 | if (id < 0) |
3591 | return id; | |
3592 | ||
3593 | /* Find and stash the function pointer for the destruction function that | |
3594 | * needs to be eventually invoked from the map free path. | |
3595 | */ | |
3596 | if (info->type == BPF_KPTR_REF) { | |
3597 | const struct btf_type *dtor_func; | |
3598 | const char *dtor_func_name; | |
3599 | unsigned long addr; | |
3600 | s32 dtor_btf_id; | |
3601 | ||
3602 | /* This call also serves as a whitelist of allowed objects that | |
3603 | * can be used as a referenced pointer and be stored in a map at | |
3604 | * the same time. | |
3605 | */ | |
c8e18754 | 3606 | dtor_btf_id = btf_find_dtor_kfunc(kptr_btf, id); |
db559117 KKD |
3607 | if (dtor_btf_id < 0) { |
3608 | ret = dtor_btf_id; | |
3609 | goto end_btf; | |
3610 | } | |
68134668 | 3611 | |
c8e18754 | 3612 | dtor_func = btf_type_by_id(kptr_btf, dtor_btf_id); |
db559117 KKD |
3613 | if (!dtor_func) { |
3614 | ret = -ENOENT; | |
3615 | goto end_btf; | |
3616 | } | |
42ba1308 | 3617 | |
c8e18754 DM |
3618 | if (btf_is_module(kptr_btf)) { |
3619 | mod = btf_try_get_module(kptr_btf); | |
db559117 KKD |
3620 | if (!mod) { |
3621 | ret = -ENXIO; | |
3622 | goto end_btf; | |
3623 | } | |
3624 | } | |
3625 | ||
3626 | /* We already verified dtor_func to be btf_type_is_func | |
3627 | * in register_btf_id_dtor_kfuncs. | |
3628 | */ | |
c8e18754 | 3629 | dtor_func_name = __btf_name_by_offset(kptr_btf, dtor_func->name_off); |
db559117 KKD |
3630 | addr = kallsyms_lookup_name(dtor_func_name); |
3631 | if (!addr) { | |
3632 | ret = -EINVAL; | |
3633 | goto end_mod; | |
3634 | } | |
3635 | field->kptr.dtor = (void *)addr; | |
3636 | } | |
3637 | ||
c8e18754 | 3638 | found_dtor: |
db559117 | 3639 | field->kptr.btf_id = id; |
c8e18754 | 3640 | field->kptr.btf = kptr_btf; |
db559117 KKD |
3641 | field->kptr.module = mod; |
3642 | return 0; | |
3643 | end_mod: | |
3644 | module_put(mod); | |
3645 | end_btf: | |
c8e18754 | 3646 | btf_put(kptr_btf); |
db559117 | 3647 | return ret; |
68134668 AS |
3648 | } |
3649 | ||
9c395c1b DM |
3650 | static int btf_parse_graph_root(const struct btf *btf, |
3651 | struct btf_field *field, | |
3652 | struct btf_field_info *info, | |
3653 | const char *node_type_name, | |
3654 | size_t node_type_align) | |
f0c5941f KKD |
3655 | { |
3656 | const struct btf_type *t, *n = NULL; | |
3657 | const struct btf_member *member; | |
3658 | u32 offset; | |
3659 | int i; | |
3660 | ||
30465003 | 3661 | t = btf_type_by_id(btf, info->graph_root.value_btf_id); |
f0c5941f KKD |
3662 | /* We've already checked that value_btf_id is a struct type. We |
3663 | * just need to figure out the offset of the list_node, and | |
3664 | * verify its type. | |
3665 | */ | |
3666 | for_each_member(i, t, member) { | |
30465003 DM |
3667 | if (strcmp(info->graph_root.node_name, |
3668 | __btf_name_by_offset(btf, member->name_off))) | |
f0c5941f KKD |
3669 | continue; |
3670 | /* Invalid BTF, two members with same name */ | |
3671 | if (n) | |
3672 | return -EINVAL; | |
3673 | n = btf_type_by_id(btf, member->type); | |
3674 | if (!__btf_type_is_struct(n)) | |
3675 | return -EINVAL; | |
9c395c1b | 3676 | if (strcmp(node_type_name, __btf_name_by_offset(btf, n->name_off))) |
f0c5941f KKD |
3677 | return -EINVAL; |
3678 | offset = __btf_member_bit_offset(n, member); | |
3679 | if (offset % 8) | |
3680 | return -EINVAL; | |
3681 | offset /= 8; | |
9c395c1b | 3682 | if (offset % node_type_align) |
f0c5941f KKD |
3683 | return -EINVAL; |
3684 | ||
30465003 DM |
3685 | field->graph_root.btf = (struct btf *)btf; |
3686 | field->graph_root.value_btf_id = info->graph_root.value_btf_id; | |
3687 | field->graph_root.node_offset = offset; | |
f0c5941f KKD |
3688 | } |
3689 | if (!n) | |
3690 | return -ENOENT; | |
3691 | return 0; | |
3692 | } | |
3693 | ||
9c395c1b DM |
3694 | static int btf_parse_list_head(const struct btf *btf, struct btf_field *field, |
3695 | struct btf_field_info *info) | |
3696 | { | |
3697 | return btf_parse_graph_root(btf, field, info, "bpf_list_node", | |
3698 | __alignof__(struct bpf_list_node)); | |
3699 | } | |
3700 | ||
3701 | static int btf_parse_rb_root(const struct btf *btf, struct btf_field *field, | |
3702 | struct btf_field_info *info) | |
3703 | { | |
3704 | return btf_parse_graph_root(btf, field, info, "bpf_rb_node", | |
3705 | __alignof__(struct bpf_rb_node)); | |
3706 | } | |
3707 | ||
cd2a8079 DM |
3708 | static int btf_field_cmp(const void *_a, const void *_b, const void *priv) |
3709 | { | |
3710 | const struct btf_field *a = (const struct btf_field *)_a; | |
3711 | const struct btf_field *b = (const struct btf_field *)_b; | |
3712 | ||
3713 | if (a->offset < b->offset) | |
3714 | return -1; | |
3715 | else if (a->offset > b->offset) | |
3716 | return 1; | |
3717 | return 0; | |
3718 | } | |
3719 | ||
db559117 KKD |
3720 | struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t, |
3721 | u32 field_mask, u32 value_size) | |
61df10c7 | 3722 | { |
aa3496ac | 3723 | struct btf_field_info info_arr[BTF_FIELDS_MAX]; |
cd2a8079 | 3724 | u32 next_off = 0, field_type_size; |
aa3496ac KKD |
3725 | struct btf_record *rec; |
3726 | int ret, i, cnt; | |
61df10c7 | 3727 | |
db559117 | 3728 | ret = btf_find_field(btf, t, field_mask, info_arr, ARRAY_SIZE(info_arr)); |
61df10c7 KKD |
3729 | if (ret < 0) |
3730 | return ERR_PTR(ret); | |
3731 | if (!ret) | |
3732 | return NULL; | |
3733 | ||
aa3496ac | 3734 | cnt = ret; |
c22dfdd2 KKD |
3735 | /* This needs to be kzalloc to zero out padding and unused fields, see |
3736 | * comment in btf_record_equal. | |
3737 | */ | |
aa3496ac KKD |
3738 | rec = kzalloc(offsetof(struct btf_record, fields[cnt]), GFP_KERNEL | __GFP_NOWARN); |
3739 | if (!rec) | |
61df10c7 | 3740 | return ERR_PTR(-ENOMEM); |
61df10c7 | 3741 | |
db559117 KKD |
3742 | rec->spin_lock_off = -EINVAL; |
3743 | rec->timer_off = -EINVAL; | |
d54730b5 | 3744 | rec->refcount_off = -EINVAL; |
db559117 | 3745 | for (i = 0; i < cnt; i++) { |
cd2a8079 DM |
3746 | field_type_size = btf_field_type_size(info_arr[i].type); |
3747 | if (info_arr[i].off + field_type_size > value_size) { | |
db559117 KKD |
3748 | WARN_ONCE(1, "verifier bug off %d size %d", info_arr[i].off, value_size); |
3749 | ret = -EFAULT; | |
61df10c7 KKD |
3750 | goto end; |
3751 | } | |
f0c5941f KKD |
3752 | if (info_arr[i].off < next_off) { |
3753 | ret = -EEXIST; | |
3754 | goto end; | |
3755 | } | |
cd2a8079 | 3756 | next_off = info_arr[i].off + field_type_size; |
61df10c7 | 3757 | |
aa3496ac KKD |
3758 | rec->field_mask |= info_arr[i].type; |
3759 | rec->fields[i].offset = info_arr[i].off; | |
3760 | rec->fields[i].type = info_arr[i].type; | |
cd2a8079 | 3761 | rec->fields[i].size = field_type_size; |
db559117 KKD |
3762 | |
3763 | switch (info_arr[i].type) { | |
3764 | case BPF_SPIN_LOCK: | |
3765 | WARN_ON_ONCE(rec->spin_lock_off >= 0); | |
3766 | /* Cache offset for faster lookup at runtime */ | |
3767 | rec->spin_lock_off = rec->fields[i].offset; | |
3768 | break; | |
3769 | case BPF_TIMER: | |
3770 | WARN_ON_ONCE(rec->timer_off >= 0); | |
3771 | /* Cache offset for faster lookup at runtime */ | |
3772 | rec->timer_off = rec->fields[i].offset; | |
3773 | break; | |
d54730b5 DM |
3774 | case BPF_REFCOUNT: |
3775 | WARN_ON_ONCE(rec->refcount_off >= 0); | |
3776 | /* Cache offset for faster lookup at runtime */ | |
3777 | rec->refcount_off = rec->fields[i].offset; | |
3778 | break; | |
db559117 KKD |
3779 | case BPF_KPTR_UNREF: |
3780 | case BPF_KPTR_REF: | |
3781 | ret = btf_parse_kptr(btf, &rec->fields[i], &info_arr[i]); | |
3782 | if (ret < 0) | |
3783 | goto end; | |
3784 | break; | |
f0c5941f KKD |
3785 | case BPF_LIST_HEAD: |
3786 | ret = btf_parse_list_head(btf, &rec->fields[i], &info_arr[i]); | |
3787 | if (ret < 0) | |
3788 | goto end; | |
3789 | break; | |
9c395c1b DM |
3790 | case BPF_RB_ROOT: |
3791 | ret = btf_parse_rb_root(btf, &rec->fields[i], &info_arr[i]); | |
3792 | if (ret < 0) | |
3793 | goto end; | |
3794 | break; | |
8ffa5cc1 | 3795 | case BPF_LIST_NODE: |
9c395c1b | 3796 | case BPF_RB_NODE: |
8ffa5cc1 | 3797 | break; |
db559117 KKD |
3798 | default: |
3799 | ret = -EFAULT; | |
3800 | goto end; | |
3801 | } | |
aa3496ac | 3802 | rec->cnt++; |
61df10c7 | 3803 | } |
f0c5941f | 3804 | |
9c395c1b DM |
3805 | /* bpf_{list_head, rb_node} require bpf_spin_lock */ |
3806 | if ((btf_record_has_field(rec, BPF_LIST_HEAD) || | |
3807 | btf_record_has_field(rec, BPF_RB_ROOT)) && rec->spin_lock_off < 0) { | |
f0c5941f KKD |
3808 | ret = -EINVAL; |
3809 | goto end; | |
3810 | } | |
3811 | ||
404ad75a DM |
3812 | if (rec->refcount_off < 0 && |
3813 | btf_record_has_field(rec, BPF_LIST_NODE) && | |
a40d3632 DM |
3814 | btf_record_has_field(rec, BPF_RB_NODE)) { |
3815 | ret = -EINVAL; | |
3816 | goto end; | |
3817 | } | |
3818 | ||
cd2a8079 DM |
3819 | sort_r(rec->fields, rec->cnt, sizeof(struct btf_field), btf_field_cmp, |
3820 | NULL, rec); | |
3821 | ||
aa3496ac | 3822 | return rec; |
61df10c7 | 3823 | end: |
aa3496ac | 3824 | btf_record_free(rec); |
61df10c7 KKD |
3825 | return ERR_PTR(ret); |
3826 | } | |
3827 | ||
9c395c1b DM |
3828 | #define GRAPH_ROOT_MASK (BPF_LIST_HEAD | BPF_RB_ROOT) |
3829 | #define GRAPH_NODE_MASK (BPF_LIST_NODE | BPF_RB_NODE) | |
3830 | ||
865ce09a KKD |
3831 | int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec) |
3832 | { | |
3833 | int i; | |
3834 | ||
9c395c1b DM |
3835 | /* There are three types that signify ownership of some other type: |
3836 | * kptr_ref, bpf_list_head, bpf_rb_root. | |
3837 | * kptr_ref only supports storing kernel types, which can't store | |
3838 | * references to program allocated local types. | |
3839 | * | |
3840 | * Hence we only need to ensure that bpf_{list_head,rb_root} ownership | |
3841 | * does not form cycles. | |
865ce09a | 3842 | */ |
9c395c1b | 3843 | if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & GRAPH_ROOT_MASK)) |
865ce09a KKD |
3844 | return 0; |
3845 | for (i = 0; i < rec->cnt; i++) { | |
3846 | struct btf_struct_meta *meta; | |
3847 | u32 btf_id; | |
3848 | ||
9c395c1b | 3849 | if (!(rec->fields[i].type & GRAPH_ROOT_MASK)) |
865ce09a | 3850 | continue; |
30465003 | 3851 | btf_id = rec->fields[i].graph_root.value_btf_id; |
865ce09a KKD |
3852 | meta = btf_find_struct_meta(btf, btf_id); |
3853 | if (!meta) | |
3854 | return -EFAULT; | |
30465003 | 3855 | rec->fields[i].graph_root.value_rec = meta->record; |
865ce09a | 3856 | |
9c395c1b DM |
3857 | /* We need to set value_rec for all root types, but no need |
3858 | * to check ownership cycle for a type unless it's also a | |
3859 | * node type. | |
3860 | */ | |
3861 | if (!(rec->field_mask & GRAPH_NODE_MASK)) | |
865ce09a KKD |
3862 | continue; |
3863 | ||
3864 | /* We need to ensure ownership acyclicity among all types. The | |
3865 | * proper way to do it would be to topologically sort all BTF | |
3866 | * IDs based on the ownership edges, since there can be multiple | |
9c395c1b DM |
3867 | * bpf_{list_head,rb_node} in a type. Instead, we use the |
3868 | * following resaoning: | |
865ce09a KKD |
3869 | * |
3870 | * - A type can only be owned by another type in user BTF if it | |
9c395c1b | 3871 | * has a bpf_{list,rb}_node. Let's call these node types. |
865ce09a | 3872 | * - A type can only _own_ another type in user BTF if it has a |
9c395c1b | 3873 | * bpf_{list_head,rb_root}. Let's call these root types. |
865ce09a | 3874 | * |
9c395c1b DM |
3875 | * We ensure that if a type is both a root and node, its |
3876 | * element types cannot be root types. | |
865ce09a KKD |
3877 | * |
3878 | * To ensure acyclicity: | |
3879 | * | |
9c395c1b DM |
3880 | * When A is an root type but not a node, its ownership |
3881 | * chain can be: | |
865ce09a KKD |
3882 | * A -> B -> C |
3883 | * Where: | |
9c395c1b DM |
3884 | * - A is an root, e.g. has bpf_rb_root. |
3885 | * - B is both a root and node, e.g. has bpf_rb_node and | |
3886 | * bpf_list_head. | |
3887 | * - C is only an root, e.g. has bpf_list_node | |
865ce09a | 3888 | * |
9c395c1b DM |
3889 | * When A is both a root and node, some other type already |
3890 | * owns it in the BTF domain, hence it can not own | |
3891 | * another root type through any of the ownership edges. | |
865ce09a KKD |
3892 | * A -> B |
3893 | * Where: | |
9c395c1b DM |
3894 | * - A is both an root and node. |
3895 | * - B is only an node. | |
865ce09a | 3896 | */ |
9c395c1b | 3897 | if (meta->record->field_mask & GRAPH_ROOT_MASK) |
865ce09a KKD |
3898 | return -ELOOP; |
3899 | } | |
3900 | return 0; | |
3901 | } | |
3902 | ||
31d0bc81 AM |
3903 | static void __btf_struct_show(const struct btf *btf, const struct btf_type *t, |
3904 | u32 type_id, void *data, u8 bits_offset, | |
3905 | struct btf_show *show) | |
b00b8dae | 3906 | { |
b00b8dae | 3907 | const struct btf_member *member; |
31d0bc81 | 3908 | void *safe_data; |
b00b8dae MKL |
3909 | u32 i; |
3910 | ||
31d0bc81 AM |
3911 | safe_data = btf_show_start_struct_type(show, t, type_id, data); |
3912 | if (!safe_data) | |
3913 | return; | |
3914 | ||
b00b8dae MKL |
3915 | for_each_member(i, t, member) { |
3916 | const struct btf_type *member_type = btf_type_by_id(btf, | |
3917 | member->type); | |
b00b8dae | 3918 | const struct btf_kind_operations *ops; |
9d5f9f70 YS |
3919 | u32 member_offset, bitfield_size; |
3920 | u32 bytes_offset; | |
3921 | u8 bits8_offset; | |
b00b8dae | 3922 | |
31d0bc81 | 3923 | btf_show_start_member(show, member); |
b00b8dae | 3924 | |
8293eb99 AS |
3925 | member_offset = __btf_member_bit_offset(t, member); |
3926 | bitfield_size = __btf_member_bitfield_size(t, member); | |
17e3ac81 YS |
3927 | bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset); |
3928 | bits8_offset = BITS_PER_BYTE_MASKED(member_offset); | |
9d5f9f70 | 3929 | if (bitfield_size) { |
31d0bc81 AM |
3930 | safe_data = btf_show_start_type(show, member_type, |
3931 | member->type, | |
3932 | data + bytes_offset); | |
3933 | if (safe_data) | |
3934 | btf_bitfield_show(safe_data, | |
3935 | bits8_offset, | |
3936 | bitfield_size, show); | |
3937 | btf_show_end_type(show); | |
9d5f9f70 | 3938 | } else { |
9d5f9f70 | 3939 | ops = btf_type_ops(member_type); |
31d0bc81 AM |
3940 | ops->show(btf, member_type, member->type, |
3941 | data + bytes_offset, bits8_offset, show); | |
9d5f9f70 | 3942 | } |
31d0bc81 AM |
3943 | |
3944 | btf_show_end_member(show); | |
b00b8dae | 3945 | } |
31d0bc81 AM |
3946 | |
3947 | btf_show_end_struct_type(show); | |
3948 | } | |
3949 | ||
3950 | static void btf_struct_show(const struct btf *btf, const struct btf_type *t, | |
3951 | u32 type_id, void *data, u8 bits_offset, | |
3952 | struct btf_show *show) | |
3953 | { | |
3954 | const struct btf_member *m = show->state.member; | |
3955 | ||
3956 | /* | |
3957 | * First check if any members would be shown (are non-zero). | |
3958 | * See comments above "struct btf_show" definition for more | |
3959 | * details on how this works at a high-level. | |
3960 | */ | |
3961 | if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) { | |
3962 | if (!show->state.depth_check) { | |
3963 | show->state.depth_check = show->state.depth + 1; | |
3964 | show->state.depth_to_show = 0; | |
3965 | } | |
3966 | __btf_struct_show(btf, t, type_id, data, bits_offset, show); | |
3967 | /* Restore saved member data here */ | |
3968 | show->state.member = m; | |
3969 | if (show->state.depth_check != show->state.depth + 1) | |
3970 | return; | |
3971 | show->state.depth_check = 0; | |
3972 | ||
3973 | if (show->state.depth_to_show <= show->state.depth) | |
3974 | return; | |
3975 | /* | |
3976 | * Reaching here indicates we have recursed and found | |
3977 | * non-zero child values. | |
3978 | */ | |
3979 | } | |
3980 | ||
3981 | __btf_struct_show(btf, t, type_id, data, bits_offset, show); | |
b00b8dae MKL |
3982 | } |
3983 | ||
69b693f0 MKL |
3984 | static struct btf_kind_operations struct_ops = { |
3985 | .check_meta = btf_struct_check_meta, | |
eb3f595d | 3986 | .resolve = btf_struct_resolve, |
179cde8c | 3987 | .check_member = btf_struct_check_member, |
9d5f9f70 | 3988 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 3989 | .log_details = btf_struct_log, |
31d0bc81 | 3990 | .show = btf_struct_show, |
69b693f0 MKL |
3991 | }; |
3992 | ||
179cde8c MKL |
3993 | static int btf_enum_check_member(struct btf_verifier_env *env, |
3994 | const struct btf_type *struct_type, | |
3995 | const struct btf_member *member, | |
3996 | const struct btf_type *member_type) | |
3997 | { | |
3998 | u32 struct_bits_off = member->offset; | |
3999 | u32 struct_size, bytes_offset; | |
4000 | ||
4001 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
4002 | btf_verifier_log_member(env, struct_type, member, | |
4003 | "Member is not byte aligned"); | |
4004 | return -EINVAL; | |
4005 | } | |
4006 | ||
4007 | struct_size = struct_type->size; | |
4008 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
da6c7fae | 4009 | if (struct_size - bytes_offset < member_type->size) { |
179cde8c MKL |
4010 | btf_verifier_log_member(env, struct_type, member, |
4011 | "Member exceeds struct_size"); | |
4012 | return -EINVAL; | |
4013 | } | |
4014 | ||
4015 | return 0; | |
4016 | } | |
4017 | ||
9d5f9f70 YS |
4018 | static int btf_enum_check_kflag_member(struct btf_verifier_env *env, |
4019 | const struct btf_type *struct_type, | |
4020 | const struct btf_member *member, | |
4021 | const struct btf_type *member_type) | |
4022 | { | |
4023 | u32 struct_bits_off, nr_bits, bytes_end, struct_size; | |
4024 | u32 int_bitsize = sizeof(int) * BITS_PER_BYTE; | |
4025 | ||
4026 | struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); | |
4027 | nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); | |
4028 | if (!nr_bits) { | |
4029 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
4030 | btf_verifier_log_member(env, struct_type, member, | |
4031 | "Member is not byte aligned"); | |
e3439af4 | 4032 | return -EINVAL; |
9d5f9f70 YS |
4033 | } |
4034 | ||
4035 | nr_bits = int_bitsize; | |
4036 | } else if (nr_bits > int_bitsize) { | |
4037 | btf_verifier_log_member(env, struct_type, member, | |
4038 | "Invalid member bitfield_size"); | |
4039 | return -EINVAL; | |
4040 | } | |
4041 | ||
4042 | struct_size = struct_type->size; | |
4043 | bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits); | |
4044 | if (struct_size < bytes_end) { | |
4045 | btf_verifier_log_member(env, struct_type, member, | |
4046 | "Member exceeds struct_size"); | |
4047 | return -EINVAL; | |
4048 | } | |
4049 | ||
4050 | return 0; | |
4051 | } | |
4052 | ||
69b693f0 MKL |
4053 | static s32 btf_enum_check_meta(struct btf_verifier_env *env, |
4054 | const struct btf_type *t, | |
4055 | u32 meta_left) | |
4056 | { | |
4057 | const struct btf_enum *enums = btf_type_enum(t); | |
4058 | struct btf *btf = env->btf; | |
6089fb32 | 4059 | const char *fmt_str; |
69b693f0 MKL |
4060 | u16 i, nr_enums; |
4061 | u32 meta_needed; | |
4062 | ||
4063 | nr_enums = btf_type_vlen(t); | |
4064 | meta_needed = nr_enums * sizeof(*enums); | |
4065 | ||
4066 | if (meta_left < meta_needed) { | |
4067 | btf_verifier_log_basic(env, t, | |
4068 | "meta_left:%u meta_needed:%u", | |
4069 | meta_left, meta_needed); | |
4070 | return -EINVAL; | |
4071 | } | |
4072 | ||
9eea9849 AS |
4073 | if (t->size > 8 || !is_power_of_2(t->size)) { |
4074 | btf_verifier_log_type(env, t, "Unexpected size"); | |
69b693f0 MKL |
4075 | return -EINVAL; |
4076 | } | |
4077 | ||
eb04bbb6 YS |
4078 | /* enum type either no name or a valid one */ |
4079 | if (t->name_off && | |
4080 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
4081 | btf_verifier_log_type(env, t, "Invalid name"); | |
4082 | return -EINVAL; | |
4083 | } | |
4084 | ||
69b693f0 MKL |
4085 | btf_verifier_log_type(env, t, NULL); |
4086 | ||
4087 | for (i = 0; i < nr_enums; i++) { | |
fbcf93eb | 4088 | if (!btf_name_offset_valid(btf, enums[i].name_off)) { |
69b693f0 | 4089 | btf_verifier_log(env, "\tInvalid name_offset:%u", |
fbcf93eb | 4090 | enums[i].name_off); |
69b693f0 MKL |
4091 | return -EINVAL; |
4092 | } | |
4093 | ||
eb04bbb6 YS |
4094 | /* enum member must have a valid name */ |
4095 | if (!enums[i].name_off || | |
4096 | !btf_name_valid_identifier(btf, enums[i].name_off)) { | |
4097 | btf_verifier_log_type(env, t, "Invalid name"); | |
4098 | return -EINVAL; | |
4099 | } | |
4100 | ||
8580ac94 AS |
4101 | if (env->log.level == BPF_LOG_KERNEL) |
4102 | continue; | |
6089fb32 YS |
4103 | fmt_str = btf_type_kflag(t) ? "\t%s val=%d\n" : "\t%s val=%u\n"; |
4104 | btf_verifier_log(env, fmt_str, | |
23127b33 | 4105 | __btf_name_by_offset(btf, enums[i].name_off), |
69b693f0 MKL |
4106 | enums[i].val); |
4107 | } | |
4108 | ||
4109 | return meta_needed; | |
4110 | } | |
4111 | ||
4112 | static void btf_enum_log(struct btf_verifier_env *env, | |
4113 | const struct btf_type *t) | |
4114 | { | |
4115 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
4116 | } | |
4117 | ||
31d0bc81 AM |
4118 | static void btf_enum_show(const struct btf *btf, const struct btf_type *t, |
4119 | u32 type_id, void *data, u8 bits_offset, | |
4120 | struct btf_show *show) | |
b00b8dae MKL |
4121 | { |
4122 | const struct btf_enum *enums = btf_type_enum(t); | |
4123 | u32 i, nr_enums = btf_type_vlen(t); | |
31d0bc81 AM |
4124 | void *safe_data; |
4125 | int v; | |
4126 | ||
4127 | safe_data = btf_show_start_type(show, t, type_id, data); | |
4128 | if (!safe_data) | |
4129 | return; | |
4130 | ||
4131 | v = *(int *)safe_data; | |
b00b8dae MKL |
4132 | |
4133 | for (i = 0; i < nr_enums; i++) { | |
31d0bc81 AM |
4134 | if (v != enums[i].val) |
4135 | continue; | |
4136 | ||
4137 | btf_show_type_value(show, "%s", | |
4138 | __btf_name_by_offset(btf, | |
4139 | enums[i].name_off)); | |
4140 | ||
4141 | btf_show_end_type(show); | |
4142 | return; | |
b00b8dae MKL |
4143 | } |
4144 | ||
6089fb32 YS |
4145 | if (btf_type_kflag(t)) |
4146 | btf_show_type_value(show, "%d", v); | |
4147 | else | |
4148 | btf_show_type_value(show, "%u", v); | |
31d0bc81 | 4149 | btf_show_end_type(show); |
b00b8dae MKL |
4150 | } |
4151 | ||
69b693f0 MKL |
4152 | static struct btf_kind_operations enum_ops = { |
4153 | .check_meta = btf_enum_check_meta, | |
eb3f595d | 4154 | .resolve = btf_df_resolve, |
179cde8c | 4155 | .check_member = btf_enum_check_member, |
9d5f9f70 | 4156 | .check_kflag_member = btf_enum_check_kflag_member, |
69b693f0 | 4157 | .log_details = btf_enum_log, |
31d0bc81 | 4158 | .show = btf_enum_show, |
69b693f0 MKL |
4159 | }; |
4160 | ||
6089fb32 YS |
4161 | static s32 btf_enum64_check_meta(struct btf_verifier_env *env, |
4162 | const struct btf_type *t, | |
4163 | u32 meta_left) | |
4164 | { | |
4165 | const struct btf_enum64 *enums = btf_type_enum64(t); | |
4166 | struct btf *btf = env->btf; | |
4167 | const char *fmt_str; | |
4168 | u16 i, nr_enums; | |
4169 | u32 meta_needed; | |
4170 | ||
4171 | nr_enums = btf_type_vlen(t); | |
4172 | meta_needed = nr_enums * sizeof(*enums); | |
4173 | ||
4174 | if (meta_left < meta_needed) { | |
4175 | btf_verifier_log_basic(env, t, | |
4176 | "meta_left:%u meta_needed:%u", | |
4177 | meta_left, meta_needed); | |
4178 | return -EINVAL; | |
4179 | } | |
4180 | ||
4181 | if (t->size > 8 || !is_power_of_2(t->size)) { | |
4182 | btf_verifier_log_type(env, t, "Unexpected size"); | |
4183 | return -EINVAL; | |
4184 | } | |
4185 | ||
4186 | /* enum type either no name or a valid one */ | |
4187 | if (t->name_off && | |
4188 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
4189 | btf_verifier_log_type(env, t, "Invalid name"); | |
4190 | return -EINVAL; | |
4191 | } | |
4192 | ||
4193 | btf_verifier_log_type(env, t, NULL); | |
4194 | ||
4195 | for (i = 0; i < nr_enums; i++) { | |
4196 | if (!btf_name_offset_valid(btf, enums[i].name_off)) { | |
4197 | btf_verifier_log(env, "\tInvalid name_offset:%u", | |
4198 | enums[i].name_off); | |
4199 | return -EINVAL; | |
4200 | } | |
4201 | ||
4202 | /* enum member must have a valid name */ | |
4203 | if (!enums[i].name_off || | |
4204 | !btf_name_valid_identifier(btf, enums[i].name_off)) { | |
4205 | btf_verifier_log_type(env, t, "Invalid name"); | |
4206 | return -EINVAL; | |
4207 | } | |
4208 | ||
4209 | if (env->log.level == BPF_LOG_KERNEL) | |
4210 | continue; | |
4211 | ||
4212 | fmt_str = btf_type_kflag(t) ? "\t%s val=%lld\n" : "\t%s val=%llu\n"; | |
4213 | btf_verifier_log(env, fmt_str, | |
4214 | __btf_name_by_offset(btf, enums[i].name_off), | |
4215 | btf_enum64_value(enums + i)); | |
4216 | } | |
4217 | ||
4218 | return meta_needed; | |
4219 | } | |
4220 | ||
4221 | static void btf_enum64_show(const struct btf *btf, const struct btf_type *t, | |
4222 | u32 type_id, void *data, u8 bits_offset, | |
4223 | struct btf_show *show) | |
4224 | { | |
4225 | const struct btf_enum64 *enums = btf_type_enum64(t); | |
4226 | u32 i, nr_enums = btf_type_vlen(t); | |
4227 | void *safe_data; | |
4228 | s64 v; | |
4229 | ||
4230 | safe_data = btf_show_start_type(show, t, type_id, data); | |
4231 | if (!safe_data) | |
4232 | return; | |
4233 | ||
4234 | v = *(u64 *)safe_data; | |
4235 | ||
4236 | for (i = 0; i < nr_enums; i++) { | |
4237 | if (v != btf_enum64_value(enums + i)) | |
4238 | continue; | |
4239 | ||
4240 | btf_show_type_value(show, "%s", | |
4241 | __btf_name_by_offset(btf, | |
4242 | enums[i].name_off)); | |
4243 | ||
4244 | btf_show_end_type(show); | |
4245 | return; | |
4246 | } | |
4247 | ||
4248 | if (btf_type_kflag(t)) | |
4249 | btf_show_type_value(show, "%lld", v); | |
4250 | else | |
4251 | btf_show_type_value(show, "%llu", v); | |
4252 | btf_show_end_type(show); | |
4253 | } | |
4254 | ||
4255 | static struct btf_kind_operations enum64_ops = { | |
4256 | .check_meta = btf_enum64_check_meta, | |
4257 | .resolve = btf_df_resolve, | |
4258 | .check_member = btf_enum_check_member, | |
4259 | .check_kflag_member = btf_enum_check_kflag_member, | |
4260 | .log_details = btf_enum_log, | |
4261 | .show = btf_enum64_show, | |
4262 | }; | |
4263 | ||
2667a262 MKL |
4264 | static s32 btf_func_proto_check_meta(struct btf_verifier_env *env, |
4265 | const struct btf_type *t, | |
4266 | u32 meta_left) | |
4267 | { | |
4268 | u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param); | |
4269 | ||
4270 | if (meta_left < meta_needed) { | |
4271 | btf_verifier_log_basic(env, t, | |
4272 | "meta_left:%u meta_needed:%u", | |
4273 | meta_left, meta_needed); | |
4274 | return -EINVAL; | |
4275 | } | |
4276 | ||
4277 | if (t->name_off) { | |
4278 | btf_verifier_log_type(env, t, "Invalid name"); | |
4279 | return -EINVAL; | |
4280 | } | |
4281 | ||
9d5f9f70 YS |
4282 | if (btf_type_kflag(t)) { |
4283 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4284 | return -EINVAL; | |
4285 | } | |
4286 | ||
2667a262 MKL |
4287 | btf_verifier_log_type(env, t, NULL); |
4288 | ||
4289 | return meta_needed; | |
4290 | } | |
4291 | ||
4292 | static void btf_func_proto_log(struct btf_verifier_env *env, | |
4293 | const struct btf_type *t) | |
4294 | { | |
4295 | const struct btf_param *args = (const struct btf_param *)(t + 1); | |
4296 | u16 nr_args = btf_type_vlen(t), i; | |
4297 | ||
4298 | btf_verifier_log(env, "return=%u args=(", t->type); | |
4299 | if (!nr_args) { | |
4300 | btf_verifier_log(env, "void"); | |
4301 | goto done; | |
4302 | } | |
4303 | ||
4304 | if (nr_args == 1 && !args[0].type) { | |
4305 | /* Only one vararg */ | |
4306 | btf_verifier_log(env, "vararg"); | |
4307 | goto done; | |
4308 | } | |
4309 | ||
4310 | btf_verifier_log(env, "%u %s", args[0].type, | |
23127b33 MKL |
4311 | __btf_name_by_offset(env->btf, |
4312 | args[0].name_off)); | |
2667a262 MKL |
4313 | for (i = 1; i < nr_args - 1; i++) |
4314 | btf_verifier_log(env, ", %u %s", args[i].type, | |
23127b33 MKL |
4315 | __btf_name_by_offset(env->btf, |
4316 | args[i].name_off)); | |
2667a262 MKL |
4317 | |
4318 | if (nr_args > 1) { | |
4319 | const struct btf_param *last_arg = &args[nr_args - 1]; | |
4320 | ||
4321 | if (last_arg->type) | |
4322 | btf_verifier_log(env, ", %u %s", last_arg->type, | |
23127b33 MKL |
4323 | __btf_name_by_offset(env->btf, |
4324 | last_arg->name_off)); | |
2667a262 MKL |
4325 | else |
4326 | btf_verifier_log(env, ", vararg"); | |
4327 | } | |
4328 | ||
4329 | done: | |
4330 | btf_verifier_log(env, ")"); | |
4331 | } | |
4332 | ||
4333 | static struct btf_kind_operations func_proto_ops = { | |
4334 | .check_meta = btf_func_proto_check_meta, | |
4335 | .resolve = btf_df_resolve, | |
4336 | /* | |
4337 | * BTF_KIND_FUNC_PROTO cannot be directly referred by | |
4338 | * a struct's member. | |
4339 | * | |
8fb33b60 | 4340 | * It should be a function pointer instead. |
2667a262 MKL |
4341 | * (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO) |
4342 | * | |
4343 | * Hence, there is no btf_func_check_member(). | |
4344 | */ | |
4345 | .check_member = btf_df_check_member, | |
9d5f9f70 | 4346 | .check_kflag_member = btf_df_check_kflag_member, |
2667a262 | 4347 | .log_details = btf_func_proto_log, |
31d0bc81 | 4348 | .show = btf_df_show, |
2667a262 MKL |
4349 | }; |
4350 | ||
4351 | static s32 btf_func_check_meta(struct btf_verifier_env *env, | |
4352 | const struct btf_type *t, | |
4353 | u32 meta_left) | |
4354 | { | |
4355 | if (!t->name_off || | |
4356 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
4357 | btf_verifier_log_type(env, t, "Invalid name"); | |
4358 | return -EINVAL; | |
4359 | } | |
4360 | ||
51c39bb1 AS |
4361 | if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) { |
4362 | btf_verifier_log_type(env, t, "Invalid func linkage"); | |
2667a262 MKL |
4363 | return -EINVAL; |
4364 | } | |
4365 | ||
9d5f9f70 YS |
4366 | if (btf_type_kflag(t)) { |
4367 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4368 | return -EINVAL; | |
4369 | } | |
4370 | ||
2667a262 MKL |
4371 | btf_verifier_log_type(env, t, NULL); |
4372 | ||
4373 | return 0; | |
4374 | } | |
4375 | ||
d7e7b42f YS |
4376 | static int btf_func_resolve(struct btf_verifier_env *env, |
4377 | const struct resolve_vertex *v) | |
4378 | { | |
4379 | const struct btf_type *t = v->t; | |
4380 | u32 next_type_id = t->type; | |
4381 | int err; | |
4382 | ||
4383 | err = btf_func_check(env, t); | |
4384 | if (err) | |
4385 | return err; | |
4386 | ||
4387 | env_stack_pop_resolved(env, next_type_id, 0); | |
4388 | return 0; | |
4389 | } | |
4390 | ||
2667a262 MKL |
4391 | static struct btf_kind_operations func_ops = { |
4392 | .check_meta = btf_func_check_meta, | |
d7e7b42f | 4393 | .resolve = btf_func_resolve, |
2667a262 | 4394 | .check_member = btf_df_check_member, |
9d5f9f70 | 4395 | .check_kflag_member = btf_df_check_kflag_member, |
2667a262 | 4396 | .log_details = btf_ref_type_log, |
31d0bc81 | 4397 | .show = btf_df_show, |
2667a262 MKL |
4398 | }; |
4399 | ||
1dc92851 DB |
4400 | static s32 btf_var_check_meta(struct btf_verifier_env *env, |
4401 | const struct btf_type *t, | |
4402 | u32 meta_left) | |
4403 | { | |
4404 | const struct btf_var *var; | |
4405 | u32 meta_needed = sizeof(*var); | |
4406 | ||
4407 | if (meta_left < meta_needed) { | |
4408 | btf_verifier_log_basic(env, t, | |
4409 | "meta_left:%u meta_needed:%u", | |
4410 | meta_left, meta_needed); | |
4411 | return -EINVAL; | |
4412 | } | |
4413 | ||
4414 | if (btf_type_vlen(t)) { | |
4415 | btf_verifier_log_type(env, t, "vlen != 0"); | |
4416 | return -EINVAL; | |
4417 | } | |
4418 | ||
4419 | if (btf_type_kflag(t)) { | |
4420 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4421 | return -EINVAL; | |
4422 | } | |
4423 | ||
4424 | if (!t->name_off || | |
4425 | !__btf_name_valid(env->btf, t->name_off, true)) { | |
4426 | btf_verifier_log_type(env, t, "Invalid name"); | |
4427 | return -EINVAL; | |
4428 | } | |
4429 | ||
4430 | /* A var cannot be in type void */ | |
4431 | if (!t->type || !BTF_TYPE_ID_VALID(t->type)) { | |
4432 | btf_verifier_log_type(env, t, "Invalid type_id"); | |
4433 | return -EINVAL; | |
4434 | } | |
4435 | ||
4436 | var = btf_type_var(t); | |
4437 | if (var->linkage != BTF_VAR_STATIC && | |
4438 | var->linkage != BTF_VAR_GLOBAL_ALLOCATED) { | |
4439 | btf_verifier_log_type(env, t, "Linkage not supported"); | |
4440 | return -EINVAL; | |
4441 | } | |
4442 | ||
4443 | btf_verifier_log_type(env, t, NULL); | |
4444 | ||
4445 | return meta_needed; | |
4446 | } | |
4447 | ||
4448 | static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t) | |
4449 | { | |
4450 | const struct btf_var *var = btf_type_var(t); | |
4451 | ||
4452 | btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage); | |
4453 | } | |
4454 | ||
4455 | static const struct btf_kind_operations var_ops = { | |
4456 | .check_meta = btf_var_check_meta, | |
4457 | .resolve = btf_var_resolve, | |
4458 | .check_member = btf_df_check_member, | |
4459 | .check_kflag_member = btf_df_check_kflag_member, | |
4460 | .log_details = btf_var_log, | |
31d0bc81 | 4461 | .show = btf_var_show, |
1dc92851 DB |
4462 | }; |
4463 | ||
4464 | static s32 btf_datasec_check_meta(struct btf_verifier_env *env, | |
4465 | const struct btf_type *t, | |
4466 | u32 meta_left) | |
4467 | { | |
4468 | const struct btf_var_secinfo *vsi; | |
4469 | u64 last_vsi_end_off = 0, sum = 0; | |
4470 | u32 i, meta_needed; | |
4471 | ||
4472 | meta_needed = btf_type_vlen(t) * sizeof(*vsi); | |
4473 | if (meta_left < meta_needed) { | |
4474 | btf_verifier_log_basic(env, t, | |
4475 | "meta_left:%u meta_needed:%u", | |
4476 | meta_left, meta_needed); | |
4477 | return -EINVAL; | |
4478 | } | |
4479 | ||
1dc92851 DB |
4480 | if (!t->size) { |
4481 | btf_verifier_log_type(env, t, "size == 0"); | |
4482 | return -EINVAL; | |
4483 | } | |
4484 | ||
4485 | if (btf_type_kflag(t)) { | |
4486 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4487 | return -EINVAL; | |
4488 | } | |
4489 | ||
4490 | if (!t->name_off || | |
4491 | !btf_name_valid_section(env->btf, t->name_off)) { | |
4492 | btf_verifier_log_type(env, t, "Invalid name"); | |
4493 | return -EINVAL; | |
4494 | } | |
4495 | ||
4496 | btf_verifier_log_type(env, t, NULL); | |
4497 | ||
4498 | for_each_vsi(i, t, vsi) { | |
4499 | /* A var cannot be in type void */ | |
4500 | if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) { | |
4501 | btf_verifier_log_vsi(env, t, vsi, | |
4502 | "Invalid type_id"); | |
4503 | return -EINVAL; | |
4504 | } | |
4505 | ||
4506 | if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) { | |
4507 | btf_verifier_log_vsi(env, t, vsi, | |
4508 | "Invalid offset"); | |
4509 | return -EINVAL; | |
4510 | } | |
4511 | ||
4512 | if (!vsi->size || vsi->size > t->size) { | |
4513 | btf_verifier_log_vsi(env, t, vsi, | |
4514 | "Invalid size"); | |
4515 | return -EINVAL; | |
4516 | } | |
4517 | ||
4518 | last_vsi_end_off = vsi->offset + vsi->size; | |
4519 | if (last_vsi_end_off > t->size) { | |
4520 | btf_verifier_log_vsi(env, t, vsi, | |
4521 | "Invalid offset+size"); | |
4522 | return -EINVAL; | |
4523 | } | |
4524 | ||
4525 | btf_verifier_log_vsi(env, t, vsi, NULL); | |
4526 | sum += vsi->size; | |
4527 | } | |
4528 | ||
4529 | if (t->size < sum) { | |
4530 | btf_verifier_log_type(env, t, "Invalid btf_info size"); | |
4531 | return -EINVAL; | |
4532 | } | |
4533 | ||
4534 | return meta_needed; | |
4535 | } | |
4536 | ||
4537 | static int btf_datasec_resolve(struct btf_verifier_env *env, | |
4538 | const struct resolve_vertex *v) | |
4539 | { | |
4540 | const struct btf_var_secinfo *vsi; | |
4541 | struct btf *btf = env->btf; | |
4542 | u16 i; | |
4543 | ||
9b459804 | 4544 | env->resolve_mode = RESOLVE_TBD; |
1dc92851 DB |
4545 | for_each_vsi_from(i, v->next_member, v->t, vsi) { |
4546 | u32 var_type_id = vsi->type, type_id, type_size = 0; | |
4547 | const struct btf_type *var_type = btf_type_by_id(env->btf, | |
4548 | var_type_id); | |
4549 | if (!var_type || !btf_type_is_var(var_type)) { | |
4550 | btf_verifier_log_vsi(env, v->t, vsi, | |
4551 | "Not a VAR kind member"); | |
4552 | return -EINVAL; | |
4553 | } | |
4554 | ||
4555 | if (!env_type_is_resolve_sink(env, var_type) && | |
4556 | !env_type_is_resolved(env, var_type_id)) { | |
4557 | env_stack_set_next_member(env, i + 1); | |
4558 | return env_stack_push(env, var_type, var_type_id); | |
4559 | } | |
4560 | ||
4561 | type_id = var_type->type; | |
4562 | if (!btf_type_id_size(btf, &type_id, &type_size)) { | |
4563 | btf_verifier_log_vsi(env, v->t, vsi, "Invalid type"); | |
4564 | return -EINVAL; | |
4565 | } | |
4566 | ||
4567 | if (vsi->size < type_size) { | |
4568 | btf_verifier_log_vsi(env, v->t, vsi, "Invalid size"); | |
4569 | return -EINVAL; | |
4570 | } | |
4571 | } | |
4572 | ||
4573 | env_stack_pop_resolved(env, 0, 0); | |
4574 | return 0; | |
4575 | } | |
4576 | ||
4577 | static void btf_datasec_log(struct btf_verifier_env *env, | |
4578 | const struct btf_type *t) | |
4579 | { | |
4580 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
4581 | } | |
4582 | ||
31d0bc81 AM |
4583 | static void btf_datasec_show(const struct btf *btf, |
4584 | const struct btf_type *t, u32 type_id, | |
4585 | void *data, u8 bits_offset, | |
4586 | struct btf_show *show) | |
1dc92851 DB |
4587 | { |
4588 | const struct btf_var_secinfo *vsi; | |
4589 | const struct btf_type *var; | |
4590 | u32 i; | |
4591 | ||
31d0bc81 AM |
4592 | if (!btf_show_start_type(show, t, type_id, data)) |
4593 | return; | |
4594 | ||
4595 | btf_show_type_value(show, "section (\"%s\") = {", | |
4596 | __btf_name_by_offset(btf, t->name_off)); | |
1dc92851 DB |
4597 | for_each_vsi(i, t, vsi) { |
4598 | var = btf_type_by_id(btf, vsi->type); | |
4599 | if (i) | |
31d0bc81 AM |
4600 | btf_show(show, ","); |
4601 | btf_type_ops(var)->show(btf, var, vsi->type, | |
4602 | data + vsi->offset, bits_offset, show); | |
1dc92851 | 4603 | } |
31d0bc81 | 4604 | btf_show_end_type(show); |
1dc92851 DB |
4605 | } |
4606 | ||
4607 | static const struct btf_kind_operations datasec_ops = { | |
4608 | .check_meta = btf_datasec_check_meta, | |
4609 | .resolve = btf_datasec_resolve, | |
4610 | .check_member = btf_df_check_member, | |
4611 | .check_kflag_member = btf_df_check_kflag_member, | |
4612 | .log_details = btf_datasec_log, | |
31d0bc81 | 4613 | .show = btf_datasec_show, |
1dc92851 DB |
4614 | }; |
4615 | ||
b1828f0b IL |
4616 | static s32 btf_float_check_meta(struct btf_verifier_env *env, |
4617 | const struct btf_type *t, | |
4618 | u32 meta_left) | |
4619 | { | |
4620 | if (btf_type_vlen(t)) { | |
4621 | btf_verifier_log_type(env, t, "vlen != 0"); | |
4622 | return -EINVAL; | |
4623 | } | |
4624 | ||
4625 | if (btf_type_kflag(t)) { | |
4626 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4627 | return -EINVAL; | |
4628 | } | |
4629 | ||
4630 | if (t->size != 2 && t->size != 4 && t->size != 8 && t->size != 12 && | |
4631 | t->size != 16) { | |
4632 | btf_verifier_log_type(env, t, "Invalid type_size"); | |
4633 | return -EINVAL; | |
4634 | } | |
4635 | ||
4636 | btf_verifier_log_type(env, t, NULL); | |
4637 | ||
4638 | return 0; | |
4639 | } | |
4640 | ||
4641 | static int btf_float_check_member(struct btf_verifier_env *env, | |
4642 | const struct btf_type *struct_type, | |
4643 | const struct btf_member *member, | |
4644 | const struct btf_type *member_type) | |
4645 | { | |
4646 | u64 start_offset_bytes; | |
4647 | u64 end_offset_bytes; | |
4648 | u64 misalign_bits; | |
4649 | u64 align_bytes; | |
4650 | u64 align_bits; | |
4651 | ||
4652 | /* Different architectures have different alignment requirements, so | |
4653 | * here we check only for the reasonable minimum. This way we ensure | |
4654 | * that types after CO-RE can pass the kernel BTF verifier. | |
4655 | */ | |
4656 | align_bytes = min_t(u64, sizeof(void *), member_type->size); | |
4657 | align_bits = align_bytes * BITS_PER_BYTE; | |
4658 | div64_u64_rem(member->offset, align_bits, &misalign_bits); | |
4659 | if (misalign_bits) { | |
4660 | btf_verifier_log_member(env, struct_type, member, | |
4661 | "Member is not properly aligned"); | |
4662 | return -EINVAL; | |
4663 | } | |
4664 | ||
4665 | start_offset_bytes = member->offset / BITS_PER_BYTE; | |
4666 | end_offset_bytes = start_offset_bytes + member_type->size; | |
4667 | if (end_offset_bytes > struct_type->size) { | |
4668 | btf_verifier_log_member(env, struct_type, member, | |
4669 | "Member exceeds struct_size"); | |
4670 | return -EINVAL; | |
4671 | } | |
4672 | ||
4673 | return 0; | |
4674 | } | |
4675 | ||
4676 | static void btf_float_log(struct btf_verifier_env *env, | |
4677 | const struct btf_type *t) | |
4678 | { | |
4679 | btf_verifier_log(env, "size=%u", t->size); | |
4680 | } | |
4681 | ||
4682 | static const struct btf_kind_operations float_ops = { | |
4683 | .check_meta = btf_float_check_meta, | |
4684 | .resolve = btf_df_resolve, | |
4685 | .check_member = btf_float_check_member, | |
4686 | .check_kflag_member = btf_generic_check_kflag_member, | |
4687 | .log_details = btf_float_log, | |
4688 | .show = btf_df_show, | |
4689 | }; | |
4690 | ||
223f903e | 4691 | static s32 btf_decl_tag_check_meta(struct btf_verifier_env *env, |
b5ea834d YS |
4692 | const struct btf_type *t, |
4693 | u32 meta_left) | |
4694 | { | |
223f903e | 4695 | const struct btf_decl_tag *tag; |
b5ea834d YS |
4696 | u32 meta_needed = sizeof(*tag); |
4697 | s32 component_idx; | |
4698 | const char *value; | |
4699 | ||
4700 | if (meta_left < meta_needed) { | |
4701 | btf_verifier_log_basic(env, t, | |
4702 | "meta_left:%u meta_needed:%u", | |
4703 | meta_left, meta_needed); | |
4704 | return -EINVAL; | |
4705 | } | |
4706 | ||
4707 | value = btf_name_by_offset(env->btf, t->name_off); | |
4708 | if (!value || !value[0]) { | |
4709 | btf_verifier_log_type(env, t, "Invalid value"); | |
4710 | return -EINVAL; | |
4711 | } | |
4712 | ||
4713 | if (btf_type_vlen(t)) { | |
4714 | btf_verifier_log_type(env, t, "vlen != 0"); | |
4715 | return -EINVAL; | |
4716 | } | |
4717 | ||
4718 | if (btf_type_kflag(t)) { | |
4719 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4720 | return -EINVAL; | |
4721 | } | |
4722 | ||
223f903e | 4723 | component_idx = btf_type_decl_tag(t)->component_idx; |
b5ea834d YS |
4724 | if (component_idx < -1) { |
4725 | btf_verifier_log_type(env, t, "Invalid component_idx"); | |
4726 | return -EINVAL; | |
4727 | } | |
4728 | ||
4729 | btf_verifier_log_type(env, t, NULL); | |
4730 | ||
4731 | return meta_needed; | |
4732 | } | |
4733 | ||
223f903e | 4734 | static int btf_decl_tag_resolve(struct btf_verifier_env *env, |
b5ea834d YS |
4735 | const struct resolve_vertex *v) |
4736 | { | |
4737 | const struct btf_type *next_type; | |
4738 | const struct btf_type *t = v->t; | |
4739 | u32 next_type_id = t->type; | |
4740 | struct btf *btf = env->btf; | |
4741 | s32 component_idx; | |
4742 | u32 vlen; | |
4743 | ||
4744 | next_type = btf_type_by_id(btf, next_type_id); | |
223f903e | 4745 | if (!next_type || !btf_type_is_decl_tag_target(next_type)) { |
b5ea834d YS |
4746 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
4747 | return -EINVAL; | |
4748 | } | |
4749 | ||
4750 | if (!env_type_is_resolve_sink(env, next_type) && | |
4751 | !env_type_is_resolved(env, next_type_id)) | |
4752 | return env_stack_push(env, next_type, next_type_id); | |
4753 | ||
223f903e | 4754 | component_idx = btf_type_decl_tag(t)->component_idx; |
b5ea834d | 4755 | if (component_idx != -1) { |
bd16dee6 | 4756 | if (btf_type_is_var(next_type) || btf_type_is_typedef(next_type)) { |
b5ea834d YS |
4757 | btf_verifier_log_type(env, v->t, "Invalid component_idx"); |
4758 | return -EINVAL; | |
4759 | } | |
4760 | ||
4761 | if (btf_type_is_struct(next_type)) { | |
4762 | vlen = btf_type_vlen(next_type); | |
4763 | } else { | |
4764 | /* next_type should be a function */ | |
4765 | next_type = btf_type_by_id(btf, next_type->type); | |
4766 | vlen = btf_type_vlen(next_type); | |
4767 | } | |
4768 | ||
4769 | if ((u32)component_idx >= vlen) { | |
4770 | btf_verifier_log_type(env, v->t, "Invalid component_idx"); | |
4771 | return -EINVAL; | |
4772 | } | |
4773 | } | |
4774 | ||
4775 | env_stack_pop_resolved(env, next_type_id, 0); | |
4776 | ||
4777 | return 0; | |
4778 | } | |
4779 | ||
223f903e | 4780 | static void btf_decl_tag_log(struct btf_verifier_env *env, const struct btf_type *t) |
b5ea834d YS |
4781 | { |
4782 | btf_verifier_log(env, "type=%u component_idx=%d", t->type, | |
223f903e | 4783 | btf_type_decl_tag(t)->component_idx); |
b5ea834d YS |
4784 | } |
4785 | ||
223f903e YS |
4786 | static const struct btf_kind_operations decl_tag_ops = { |
4787 | .check_meta = btf_decl_tag_check_meta, | |
4788 | .resolve = btf_decl_tag_resolve, | |
b5ea834d YS |
4789 | .check_member = btf_df_check_member, |
4790 | .check_kflag_member = btf_df_check_kflag_member, | |
223f903e | 4791 | .log_details = btf_decl_tag_log, |
b5ea834d YS |
4792 | .show = btf_df_show, |
4793 | }; | |
4794 | ||
2667a262 MKL |
4795 | static int btf_func_proto_check(struct btf_verifier_env *env, |
4796 | const struct btf_type *t) | |
4797 | { | |
4798 | const struct btf_type *ret_type; | |
4799 | const struct btf_param *args; | |
4800 | const struct btf *btf; | |
4801 | u16 nr_args, i; | |
4802 | int err; | |
4803 | ||
4804 | btf = env->btf; | |
4805 | args = (const struct btf_param *)(t + 1); | |
4806 | nr_args = btf_type_vlen(t); | |
4807 | ||
4808 | /* Check func return type which could be "void" (t->type == 0) */ | |
4809 | if (t->type) { | |
4810 | u32 ret_type_id = t->type; | |
4811 | ||
4812 | ret_type = btf_type_by_id(btf, ret_type_id); | |
4813 | if (!ret_type) { | |
4814 | btf_verifier_log_type(env, t, "Invalid return type"); | |
4815 | return -EINVAL; | |
4816 | } | |
4817 | ||
ea68376c SF |
4818 | if (btf_type_is_resolve_source_only(ret_type)) { |
4819 | btf_verifier_log_type(env, t, "Invalid return type"); | |
4820 | return -EINVAL; | |
4821 | } | |
4822 | ||
2667a262 MKL |
4823 | if (btf_type_needs_resolve(ret_type) && |
4824 | !env_type_is_resolved(env, ret_type_id)) { | |
4825 | err = btf_resolve(env, ret_type, ret_type_id); | |
4826 | if (err) | |
4827 | return err; | |
4828 | } | |
4829 | ||
4830 | /* Ensure the return type is a type that has a size */ | |
4831 | if (!btf_type_id_size(btf, &ret_type_id, NULL)) { | |
4832 | btf_verifier_log_type(env, t, "Invalid return type"); | |
4833 | return -EINVAL; | |
4834 | } | |
4835 | } | |
4836 | ||
4837 | if (!nr_args) | |
4838 | return 0; | |
4839 | ||
4840 | /* Last func arg type_id could be 0 if it is a vararg */ | |
4841 | if (!args[nr_args - 1].type) { | |
4842 | if (args[nr_args - 1].name_off) { | |
4843 | btf_verifier_log_type(env, t, "Invalid arg#%u", | |
4844 | nr_args); | |
4845 | return -EINVAL; | |
4846 | } | |
4847 | nr_args--; | |
4848 | } | |
4849 | ||
2667a262 MKL |
4850 | for (i = 0; i < nr_args; i++) { |
4851 | const struct btf_type *arg_type; | |
4852 | u32 arg_type_id; | |
4853 | ||
4854 | arg_type_id = args[i].type; | |
4855 | arg_type = btf_type_by_id(btf, arg_type_id); | |
4856 | if (!arg_type) { | |
4857 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
5bad3587 | 4858 | return -EINVAL; |
2667a262 MKL |
4859 | } |
4860 | ||
f17472d4 SF |
4861 | if (btf_type_is_resolve_source_only(arg_type)) { |
4862 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
4863 | return -EINVAL; | |
4864 | } | |
4865 | ||
2667a262 MKL |
4866 | if (args[i].name_off && |
4867 | (!btf_name_offset_valid(btf, args[i].name_off) || | |
4868 | !btf_name_valid_identifier(btf, args[i].name_off))) { | |
4869 | btf_verifier_log_type(env, t, | |
4870 | "Invalid arg#%u", i + 1); | |
5bad3587 | 4871 | return -EINVAL; |
2667a262 MKL |
4872 | } |
4873 | ||
4874 | if (btf_type_needs_resolve(arg_type) && | |
4875 | !env_type_is_resolved(env, arg_type_id)) { | |
4876 | err = btf_resolve(env, arg_type, arg_type_id); | |
4877 | if (err) | |
5bad3587 | 4878 | return err; |
2667a262 MKL |
4879 | } |
4880 | ||
4881 | if (!btf_type_id_size(btf, &arg_type_id, NULL)) { | |
4882 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
5bad3587 | 4883 | return -EINVAL; |
2667a262 MKL |
4884 | } |
4885 | } | |
4886 | ||
5bad3587 | 4887 | return 0; |
2667a262 MKL |
4888 | } |
4889 | ||
4890 | static int btf_func_check(struct btf_verifier_env *env, | |
4891 | const struct btf_type *t) | |
4892 | { | |
4893 | const struct btf_type *proto_type; | |
4894 | const struct btf_param *args; | |
4895 | const struct btf *btf; | |
4896 | u16 nr_args, i; | |
4897 | ||
4898 | btf = env->btf; | |
4899 | proto_type = btf_type_by_id(btf, t->type); | |
4900 | ||
4901 | if (!proto_type || !btf_type_is_func_proto(proto_type)) { | |
4902 | btf_verifier_log_type(env, t, "Invalid type_id"); | |
4903 | return -EINVAL; | |
4904 | } | |
4905 | ||
4906 | args = (const struct btf_param *)(proto_type + 1); | |
4907 | nr_args = btf_type_vlen(proto_type); | |
4908 | for (i = 0; i < nr_args; i++) { | |
4909 | if (!args[i].name_off && args[i].type) { | |
4910 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
4911 | return -EINVAL; | |
4912 | } | |
4913 | } | |
4914 | ||
4915 | return 0; | |
4916 | } | |
4917 | ||
69b693f0 MKL |
4918 | static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = { |
4919 | [BTF_KIND_INT] = &int_ops, | |
4920 | [BTF_KIND_PTR] = &ptr_ops, | |
4921 | [BTF_KIND_ARRAY] = &array_ops, | |
4922 | [BTF_KIND_STRUCT] = &struct_ops, | |
4923 | [BTF_KIND_UNION] = &struct_ops, | |
4924 | [BTF_KIND_ENUM] = &enum_ops, | |
4925 | [BTF_KIND_FWD] = &fwd_ops, | |
4926 | [BTF_KIND_TYPEDEF] = &modifier_ops, | |
4927 | [BTF_KIND_VOLATILE] = &modifier_ops, | |
4928 | [BTF_KIND_CONST] = &modifier_ops, | |
4929 | [BTF_KIND_RESTRICT] = &modifier_ops, | |
2667a262 MKL |
4930 | [BTF_KIND_FUNC] = &func_ops, |
4931 | [BTF_KIND_FUNC_PROTO] = &func_proto_ops, | |
1dc92851 DB |
4932 | [BTF_KIND_VAR] = &var_ops, |
4933 | [BTF_KIND_DATASEC] = &datasec_ops, | |
b1828f0b | 4934 | [BTF_KIND_FLOAT] = &float_ops, |
223f903e | 4935 | [BTF_KIND_DECL_TAG] = &decl_tag_ops, |
8c42d2fa | 4936 | [BTF_KIND_TYPE_TAG] = &modifier_ops, |
6089fb32 | 4937 | [BTF_KIND_ENUM64] = &enum64_ops, |
69b693f0 MKL |
4938 | }; |
4939 | ||
4940 | static s32 btf_check_meta(struct btf_verifier_env *env, | |
4941 | const struct btf_type *t, | |
4942 | u32 meta_left) | |
4943 | { | |
4944 | u32 saved_meta_left = meta_left; | |
4945 | s32 var_meta_size; | |
4946 | ||
4947 | if (meta_left < sizeof(*t)) { | |
4948 | btf_verifier_log(env, "[%u] meta_left:%u meta_needed:%zu", | |
4949 | env->log_type_id, meta_left, sizeof(*t)); | |
4950 | return -EINVAL; | |
4951 | } | |
4952 | meta_left -= sizeof(*t); | |
4953 | ||
aea2f7b8 MKL |
4954 | if (t->info & ~BTF_INFO_MASK) { |
4955 | btf_verifier_log(env, "[%u] Invalid btf_info:%x", | |
4956 | env->log_type_id, t->info); | |
4957 | return -EINVAL; | |
4958 | } | |
4959 | ||
69b693f0 MKL |
4960 | if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX || |
4961 | BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) { | |
4962 | btf_verifier_log(env, "[%u] Invalid kind:%u", | |
4963 | env->log_type_id, BTF_INFO_KIND(t->info)); | |
4964 | return -EINVAL; | |
4965 | } | |
4966 | ||
fbcf93eb | 4967 | if (!btf_name_offset_valid(env->btf, t->name_off)) { |
69b693f0 | 4968 | btf_verifier_log(env, "[%u] Invalid name_offset:%u", |
fbcf93eb | 4969 | env->log_type_id, t->name_off); |
69b693f0 MKL |
4970 | return -EINVAL; |
4971 | } | |
4972 | ||
4973 | var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left); | |
4974 | if (var_meta_size < 0) | |
4975 | return var_meta_size; | |
4976 | ||
4977 | meta_left -= var_meta_size; | |
4978 | ||
4979 | return saved_meta_left - meta_left; | |
4980 | } | |
4981 | ||
4982 | static int btf_check_all_metas(struct btf_verifier_env *env) | |
4983 | { | |
4984 | struct btf *btf = env->btf; | |
4985 | struct btf_header *hdr; | |
4986 | void *cur, *end; | |
4987 | ||
f80442a4 | 4988 | hdr = &btf->hdr; |
69b693f0 | 4989 | cur = btf->nohdr_data + hdr->type_off; |
4b1c5d91 | 4990 | end = cur + hdr->type_len; |
69b693f0 | 4991 | |
951bb646 | 4992 | env->log_type_id = btf->base_btf ? btf->start_id : 1; |
69b693f0 MKL |
4993 | while (cur < end) { |
4994 | struct btf_type *t = cur; | |
4995 | s32 meta_size; | |
4996 | ||
4997 | meta_size = btf_check_meta(env, t, end - cur); | |
4998 | if (meta_size < 0) | |
4999 | return meta_size; | |
5000 | ||
5001 | btf_add_type(env, t); | |
5002 | cur += meta_size; | |
5003 | env->log_type_id++; | |
5004 | } | |
5005 | ||
5006 | return 0; | |
5007 | } | |
5008 | ||
eb3f595d MKL |
5009 | static bool btf_resolve_valid(struct btf_verifier_env *env, |
5010 | const struct btf_type *t, | |
5011 | u32 type_id) | |
5012 | { | |
5013 | struct btf *btf = env->btf; | |
5014 | ||
5015 | if (!env_type_is_resolved(env, type_id)) | |
5016 | return false; | |
5017 | ||
1dc92851 | 5018 | if (btf_type_is_struct(t) || btf_type_is_datasec(t)) |
951bb646 AN |
5019 | return !btf_resolved_type_id(btf, type_id) && |
5020 | !btf_resolved_type_size(btf, type_id); | |
eb3f595d | 5021 | |
d7e7b42f | 5022 | if (btf_type_is_decl_tag(t) || btf_type_is_func(t)) |
b5ea834d YS |
5023 | return btf_resolved_type_id(btf, type_id) && |
5024 | !btf_resolved_type_size(btf, type_id); | |
5025 | ||
1dc92851 DB |
5026 | if (btf_type_is_modifier(t) || btf_type_is_ptr(t) || |
5027 | btf_type_is_var(t)) { | |
eb3f595d | 5028 | t = btf_type_id_resolve(btf, &type_id); |
1dc92851 DB |
5029 | return t && |
5030 | !btf_type_is_modifier(t) && | |
5031 | !btf_type_is_var(t) && | |
5032 | !btf_type_is_datasec(t); | |
eb3f595d MKL |
5033 | } |
5034 | ||
5035 | if (btf_type_is_array(t)) { | |
5036 | const struct btf_array *array = btf_type_array(t); | |
5037 | const struct btf_type *elem_type; | |
5038 | u32 elem_type_id = array->type; | |
5039 | u32 elem_size; | |
5040 | ||
5041 | elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); | |
5042 | return elem_type && !btf_type_is_modifier(elem_type) && | |
5043 | (array->nelems * elem_size == | |
951bb646 | 5044 | btf_resolved_type_size(btf, type_id)); |
eb3f595d MKL |
5045 | } |
5046 | ||
5047 | return false; | |
5048 | } | |
5049 | ||
2667a262 MKL |
5050 | static int btf_resolve(struct btf_verifier_env *env, |
5051 | const struct btf_type *t, u32 type_id) | |
5052 | { | |
5053 | u32 save_log_type_id = env->log_type_id; | |
5054 | const struct resolve_vertex *v; | |
5055 | int err = 0; | |
5056 | ||
5057 | env->resolve_mode = RESOLVE_TBD; | |
5058 | env_stack_push(env, t, type_id); | |
5059 | while (!err && (v = env_stack_peak(env))) { | |
5060 | env->log_type_id = v->type_id; | |
5061 | err = btf_type_ops(v->t)->resolve(env, v); | |
5062 | } | |
5063 | ||
5064 | env->log_type_id = type_id; | |
5065 | if (err == -E2BIG) { | |
5066 | btf_verifier_log_type(env, t, | |
5067 | "Exceeded max resolving depth:%u", | |
5068 | MAX_RESOLVE_DEPTH); | |
5069 | } else if (err == -EEXIST) { | |
5070 | btf_verifier_log_type(env, t, "Loop detected"); | |
5071 | } | |
5072 | ||
5073 | /* Final sanity check */ | |
5074 | if (!err && !btf_resolve_valid(env, t, type_id)) { | |
5075 | btf_verifier_log_type(env, t, "Invalid resolve state"); | |
5076 | err = -EINVAL; | |
5077 | } | |
5078 | ||
5079 | env->log_type_id = save_log_type_id; | |
5080 | return err; | |
5081 | } | |
5082 | ||
eb3f595d MKL |
5083 | static int btf_check_all_types(struct btf_verifier_env *env) |
5084 | { | |
5085 | struct btf *btf = env->btf; | |
951bb646 AN |
5086 | const struct btf_type *t; |
5087 | u32 type_id, i; | |
eb3f595d MKL |
5088 | int err; |
5089 | ||
5090 | err = env_resolve_init(env); | |
5091 | if (err) | |
5092 | return err; | |
5093 | ||
5094 | env->phase++; | |
951bb646 AN |
5095 | for (i = btf->base_btf ? 0 : 1; i < btf->nr_types; i++) { |
5096 | type_id = btf->start_id + i; | |
5097 | t = btf_type_by_id(btf, type_id); | |
eb3f595d MKL |
5098 | |
5099 | env->log_type_id = type_id; | |
5100 | if (btf_type_needs_resolve(t) && | |
5101 | !env_type_is_resolved(env, type_id)) { | |
5102 | err = btf_resolve(env, t, type_id); | |
5103 | if (err) | |
5104 | return err; | |
5105 | } | |
5106 | ||
2667a262 MKL |
5107 | if (btf_type_is_func_proto(t)) { |
5108 | err = btf_func_proto_check(env, t); | |
5109 | if (err) | |
5110 | return err; | |
5111 | } | |
eb3f595d MKL |
5112 | } |
5113 | ||
5114 | return 0; | |
5115 | } | |
5116 | ||
69b693f0 MKL |
5117 | static int btf_parse_type_sec(struct btf_verifier_env *env) |
5118 | { | |
f80442a4 | 5119 | const struct btf_header *hdr = &env->btf->hdr; |
eb3f595d MKL |
5120 | int err; |
5121 | ||
f80442a4 MKL |
5122 | /* Type section must align to 4 bytes */ |
5123 | if (hdr->type_off & (sizeof(u32) - 1)) { | |
5124 | btf_verifier_log(env, "Unaligned type_off"); | |
5125 | return -EINVAL; | |
5126 | } | |
5127 | ||
951bb646 | 5128 | if (!env->btf->base_btf && !hdr->type_len) { |
f80442a4 MKL |
5129 | btf_verifier_log(env, "No type found"); |
5130 | return -EINVAL; | |
5131 | } | |
5132 | ||
eb3f595d MKL |
5133 | err = btf_check_all_metas(env); |
5134 | if (err) | |
5135 | return err; | |
5136 | ||
5137 | return btf_check_all_types(env); | |
69b693f0 MKL |
5138 | } |
5139 | ||
5140 | static int btf_parse_str_sec(struct btf_verifier_env *env) | |
5141 | { | |
5142 | const struct btf_header *hdr; | |
5143 | struct btf *btf = env->btf; | |
5144 | const char *start, *end; | |
5145 | ||
f80442a4 | 5146 | hdr = &btf->hdr; |
69b693f0 MKL |
5147 | start = btf->nohdr_data + hdr->str_off; |
5148 | end = start + hdr->str_len; | |
5149 | ||
f80442a4 MKL |
5150 | if (end != btf->data + btf->data_size) { |
5151 | btf_verifier_log(env, "String section is not at the end"); | |
5152 | return -EINVAL; | |
5153 | } | |
5154 | ||
951bb646 AN |
5155 | btf->strings = start; |
5156 | ||
5157 | if (btf->base_btf && !hdr->str_len) | |
5158 | return 0; | |
5159 | if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET || end[-1]) { | |
5160 | btf_verifier_log(env, "Invalid string section"); | |
5161 | return -EINVAL; | |
5162 | } | |
5163 | if (!btf->base_btf && start[0]) { | |
69b693f0 MKL |
5164 | btf_verifier_log(env, "Invalid string section"); |
5165 | return -EINVAL; | |
5166 | } | |
69b693f0 MKL |
5167 | |
5168 | return 0; | |
5169 | } | |
5170 | ||
f80442a4 MKL |
5171 | static const size_t btf_sec_info_offset[] = { |
5172 | offsetof(struct btf_header, type_off), | |
5173 | offsetof(struct btf_header, str_off), | |
5174 | }; | |
5175 | ||
5176 | static int btf_sec_info_cmp(const void *a, const void *b) | |
69b693f0 | 5177 | { |
f80442a4 MKL |
5178 | const struct btf_sec_info *x = a; |
5179 | const struct btf_sec_info *y = b; | |
5180 | ||
5181 | return (int)(x->off - y->off) ? : (int)(x->len - y->len); | |
5182 | } | |
5183 | ||
5184 | static int btf_check_sec_info(struct btf_verifier_env *env, | |
5185 | u32 btf_data_size) | |
5186 | { | |
a2889a4c | 5187 | struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)]; |
f80442a4 | 5188 | u32 total, expected_total, i; |
69b693f0 | 5189 | const struct btf_header *hdr; |
f80442a4 MKL |
5190 | const struct btf *btf; |
5191 | ||
5192 | btf = env->btf; | |
5193 | hdr = &btf->hdr; | |
5194 | ||
5195 | /* Populate the secs from hdr */ | |
a2889a4c | 5196 | for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) |
f80442a4 MKL |
5197 | secs[i] = *(struct btf_sec_info *)((void *)hdr + |
5198 | btf_sec_info_offset[i]); | |
5199 | ||
a2889a4c MKL |
5200 | sort(secs, ARRAY_SIZE(btf_sec_info_offset), |
5201 | sizeof(struct btf_sec_info), btf_sec_info_cmp, NULL); | |
f80442a4 MKL |
5202 | |
5203 | /* Check for gaps and overlap among sections */ | |
5204 | total = 0; | |
5205 | expected_total = btf_data_size - hdr->hdr_len; | |
a2889a4c | 5206 | for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) { |
f80442a4 MKL |
5207 | if (expected_total < secs[i].off) { |
5208 | btf_verifier_log(env, "Invalid section offset"); | |
5209 | return -EINVAL; | |
5210 | } | |
5211 | if (total < secs[i].off) { | |
5212 | /* gap */ | |
5213 | btf_verifier_log(env, "Unsupported section found"); | |
5214 | return -EINVAL; | |
5215 | } | |
5216 | if (total > secs[i].off) { | |
5217 | btf_verifier_log(env, "Section overlap found"); | |
5218 | return -EINVAL; | |
5219 | } | |
5220 | if (expected_total - total < secs[i].len) { | |
5221 | btf_verifier_log(env, | |
5222 | "Total section length too long"); | |
5223 | return -EINVAL; | |
5224 | } | |
5225 | total += secs[i].len; | |
5226 | } | |
5227 | ||
5228 | /* There is data other than hdr and known sections */ | |
5229 | if (expected_total != total) { | |
5230 | btf_verifier_log(env, "Unsupported section found"); | |
5231 | return -EINVAL; | |
5232 | } | |
5233 | ||
5234 | return 0; | |
5235 | } | |
5236 | ||
4a6998af | 5237 | static int btf_parse_hdr(struct btf_verifier_env *env) |
f80442a4 | 5238 | { |
4a6998af | 5239 | u32 hdr_len, hdr_copy, btf_data_size; |
f80442a4 | 5240 | const struct btf_header *hdr; |
f80442a4 | 5241 | struct btf *btf; |
69b693f0 | 5242 | |
f80442a4 | 5243 | btf = env->btf; |
4a6998af | 5244 | btf_data_size = btf->data_size; |
f80442a4 | 5245 | |
583669ab | 5246 | if (btf_data_size < offsetofend(struct btf_header, hdr_len)) { |
f80442a4 MKL |
5247 | btf_verifier_log(env, "hdr_len not found"); |
5248 | return -EINVAL; | |
5249 | } | |
5250 | ||
4a6998af ML |
5251 | hdr = btf->data; |
5252 | hdr_len = hdr->hdr_len; | |
f80442a4 | 5253 | if (btf_data_size < hdr_len) { |
69b693f0 MKL |
5254 | btf_verifier_log(env, "btf_header not found"); |
5255 | return -EINVAL; | |
5256 | } | |
5257 | ||
4a6998af ML |
5258 | /* Ensure the unsupported header fields are zero */ |
5259 | if (hdr_len > sizeof(btf->hdr)) { | |
5260 | u8 *expected_zero = btf->data + sizeof(btf->hdr); | |
5261 | u8 *end = btf->data + hdr_len; | |
5262 | ||
5263 | for (; expected_zero < end; expected_zero++) { | |
5264 | if (*expected_zero) { | |
5265 | btf_verifier_log(env, "Unsupported btf_header"); | |
5266 | return -E2BIG; | |
5267 | } | |
5268 | } | |
f80442a4 MKL |
5269 | } |
5270 | ||
5271 | hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr)); | |
4a6998af | 5272 | memcpy(&btf->hdr, btf->data, hdr_copy); |
f80442a4 MKL |
5273 | |
5274 | hdr = &btf->hdr; | |
5275 | ||
5276 | btf_verifier_log_hdr(env, btf_data_size); | |
69b693f0 | 5277 | |
69b693f0 MKL |
5278 | if (hdr->magic != BTF_MAGIC) { |
5279 | btf_verifier_log(env, "Invalid magic"); | |
5280 | return -EINVAL; | |
5281 | } | |
5282 | ||
5283 | if (hdr->version != BTF_VERSION) { | |
5284 | btf_verifier_log(env, "Unsupported version"); | |
5285 | return -ENOTSUPP; | |
5286 | } | |
5287 | ||
5288 | if (hdr->flags) { | |
5289 | btf_verifier_log(env, "Unsupported flags"); | |
5290 | return -ENOTSUPP; | |
5291 | } | |
5292 | ||
bcc5e616 | 5293 | if (!btf->base_btf && btf_data_size == hdr->hdr_len) { |
69b693f0 MKL |
5294 | btf_verifier_log(env, "No data"); |
5295 | return -EINVAL; | |
5296 | } | |
5297 | ||
3a74904c | 5298 | return btf_check_sec_info(env, btf_data_size); |
69b693f0 MKL |
5299 | } |
5300 | ||
8ffa5cc1 KKD |
5301 | static const char *alloc_obj_fields[] = { |
5302 | "bpf_spin_lock", | |
5303 | "bpf_list_head", | |
5304 | "bpf_list_node", | |
9c395c1b DM |
5305 | "bpf_rb_root", |
5306 | "bpf_rb_node", | |
d54730b5 | 5307 | "bpf_refcount", |
8ffa5cc1 KKD |
5308 | }; |
5309 | ||
5310 | static struct btf_struct_metas * | |
5311 | btf_parse_struct_metas(struct bpf_verifier_log *log, struct btf *btf) | |
5312 | { | |
5313 | union { | |
5314 | struct btf_id_set set; | |
5315 | struct { | |
5316 | u32 _cnt; | |
5317 | u32 _ids[ARRAY_SIZE(alloc_obj_fields)]; | |
5318 | } _arr; | |
5319 | } aof; | |
5320 | struct btf_struct_metas *tab = NULL; | |
5321 | int i, n, id, ret; | |
5322 | ||
5323 | BUILD_BUG_ON(offsetof(struct btf_id_set, cnt) != 0); | |
5324 | BUILD_BUG_ON(sizeof(struct btf_id_set) != sizeof(u32)); | |
5325 | ||
5326 | memset(&aof, 0, sizeof(aof)); | |
5327 | for (i = 0; i < ARRAY_SIZE(alloc_obj_fields); i++) { | |
5328 | /* Try to find whether this special type exists in user BTF, and | |
5329 | * if so remember its ID so we can easily find it among members | |
5330 | * of structs that we iterate in the next loop. | |
5331 | */ | |
5332 | id = btf_find_by_name_kind(btf, alloc_obj_fields[i], BTF_KIND_STRUCT); | |
5333 | if (id < 0) | |
5334 | continue; | |
5335 | aof.set.ids[aof.set.cnt++] = id; | |
5336 | } | |
5337 | ||
5338 | if (!aof.set.cnt) | |
5339 | return NULL; | |
5340 | sort(&aof.set.ids, aof.set.cnt, sizeof(aof.set.ids[0]), btf_id_cmp_func, NULL); | |
5341 | ||
5342 | n = btf_nr_types(btf); | |
5343 | for (i = 1; i < n; i++) { | |
5344 | struct btf_struct_metas *new_tab; | |
5345 | const struct btf_member *member; | |
8ffa5cc1 KKD |
5346 | struct btf_struct_meta *type; |
5347 | struct btf_record *record; | |
5348 | const struct btf_type *t; | |
5349 | int j, tab_cnt; | |
5350 | ||
5351 | t = btf_type_by_id(btf, i); | |
5352 | if (!t) { | |
5353 | ret = -EINVAL; | |
5354 | goto free; | |
5355 | } | |
5356 | if (!__btf_type_is_struct(t)) | |
5357 | continue; | |
5358 | ||
5359 | cond_resched(); | |
5360 | ||
5361 | for_each_member(j, t, member) { | |
5362 | if (btf_id_set_contains(&aof.set, member->type)) | |
5363 | goto parse; | |
5364 | } | |
5365 | continue; | |
5366 | parse: | |
5367 | tab_cnt = tab ? tab->cnt : 0; | |
5368 | new_tab = krealloc(tab, offsetof(struct btf_struct_metas, types[tab_cnt + 1]), | |
5369 | GFP_KERNEL | __GFP_NOWARN); | |
5370 | if (!new_tab) { | |
5371 | ret = -ENOMEM; | |
5372 | goto free; | |
5373 | } | |
5374 | if (!tab) | |
5375 | new_tab->cnt = 0; | |
5376 | tab = new_tab; | |
5377 | ||
5378 | type = &tab->types[tab->cnt]; | |
5379 | type->btf_id = i; | |
9c395c1b | 5380 | record = btf_parse_fields(btf, t, BPF_SPIN_LOCK | BPF_LIST_HEAD | BPF_LIST_NODE | |
d54730b5 | 5381 | BPF_RB_ROOT | BPF_RB_NODE | BPF_REFCOUNT, t->size); |
8ffa5cc1 KKD |
5382 | /* The record cannot be unset, treat it as an error if so */ |
5383 | if (IS_ERR_OR_NULL(record)) { | |
5384 | ret = PTR_ERR_OR_ZERO(record) ?: -EFAULT; | |
5385 | goto free; | |
5386 | } | |
8ffa5cc1 | 5387 | type->record = record; |
8ffa5cc1 KKD |
5388 | tab->cnt++; |
5389 | } | |
5390 | return tab; | |
5391 | free: | |
5392 | btf_struct_metas_free(tab); | |
5393 | return ERR_PTR(ret); | |
5394 | } | |
5395 | ||
5396 | struct btf_struct_meta *btf_find_struct_meta(const struct btf *btf, u32 btf_id) | |
5397 | { | |
5398 | struct btf_struct_metas *tab; | |
5399 | ||
5400 | BUILD_BUG_ON(offsetof(struct btf_struct_meta, btf_id) != 0); | |
5401 | tab = btf->struct_meta_tab; | |
5402 | if (!tab) | |
5403 | return NULL; | |
5404 | return bsearch(&btf_id, tab->types, tab->cnt, sizeof(tab->types[0]), btf_id_cmp_func); | |
5405 | } | |
5406 | ||
eb596b09 KKD |
5407 | static int btf_check_type_tags(struct btf_verifier_env *env, |
5408 | struct btf *btf, int start_id) | |
5409 | { | |
5410 | int i, n, good_id = start_id - 1; | |
5411 | bool in_tags; | |
5412 | ||
5413 | n = btf_nr_types(btf); | |
5414 | for (i = start_id; i < n; i++) { | |
5415 | const struct btf_type *t; | |
d1a374a1 | 5416 | int chain_limit = 32; |
eb596b09 KKD |
5417 | u32 cur_id = i; |
5418 | ||
5419 | t = btf_type_by_id(btf, i); | |
5420 | if (!t) | |
5421 | return -EINVAL; | |
5422 | if (!btf_type_is_modifier(t)) | |
5423 | continue; | |
5424 | ||
5425 | cond_resched(); | |
5426 | ||
5427 | in_tags = btf_type_is_type_tag(t); | |
5428 | while (btf_type_is_modifier(t)) { | |
d1a374a1 KKD |
5429 | if (!chain_limit--) { |
5430 | btf_verifier_log(env, "Max chain length or cycle detected"); | |
5431 | return -ELOOP; | |
5432 | } | |
eb596b09 KKD |
5433 | if (btf_type_is_type_tag(t)) { |
5434 | if (!in_tags) { | |
5435 | btf_verifier_log(env, "Type tags don't precede modifiers"); | |
5436 | return -EINVAL; | |
5437 | } | |
5438 | } else if (in_tags) { | |
5439 | in_tags = false; | |
5440 | } | |
5441 | if (cur_id <= good_id) | |
5442 | break; | |
5443 | /* Move to next type */ | |
5444 | cur_id = t->type; | |
5445 | t = btf_type_by_id(btf, cur_id); | |
5446 | if (!t) | |
5447 | return -EINVAL; | |
5448 | } | |
5449 | good_id = i; | |
5450 | } | |
5451 | return 0; | |
5452 | } | |
5453 | ||
bdcab414 | 5454 | static int finalize_log(struct bpf_verifier_log *log, bpfptr_t uattr, u32 uattr_size) |
69b693f0 | 5455 | { |
bdcab414 AN |
5456 | u32 log_true_size; |
5457 | int err; | |
5458 | ||
5459 | err = bpf_vlog_finalize(log, &log_true_size); | |
5460 | ||
5461 | if (uattr_size >= offsetofend(union bpf_attr, btf_log_true_size) && | |
5462 | copy_to_bpfptr_offset(uattr, offsetof(union bpf_attr, btf_log_true_size), | |
5463 | &log_true_size, sizeof(log_true_size))) | |
5464 | err = -EFAULT; | |
5465 | ||
5466 | return err; | |
5467 | } | |
5468 | ||
47a71c1f | 5469 | static struct btf *btf_parse(const union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size) |
69b693f0 | 5470 | { |
47a71c1f AN |
5471 | bpfptr_t btf_data = make_bpfptr(attr->btf, uattr.is_kernel); |
5472 | char __user *log_ubuf = u64_to_user_ptr(attr->btf_log_buf); | |
8ffa5cc1 | 5473 | struct btf_struct_metas *struct_meta_tab; |
69b693f0 | 5474 | struct btf_verifier_env *env = NULL; |
69b693f0 MKL |
5475 | struct btf *btf = NULL; |
5476 | u8 *data; | |
bdcab414 | 5477 | int err, ret; |
69b693f0 | 5478 | |
47a71c1f | 5479 | if (attr->btf_size > BTF_MAX_SIZE) |
69b693f0 MKL |
5480 | return ERR_PTR(-E2BIG); |
5481 | ||
5482 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
5483 | if (!env) | |
5484 | return ERR_PTR(-ENOMEM); | |
5485 | ||
bdcab414 AN |
5486 | /* user could have requested verbose verifier output |
5487 | * and supplied buffer to store the verification trace | |
5488 | */ | |
5489 | err = bpf_vlog_init(&env->log, attr->btf_log_level, | |
5490 | log_ubuf, attr->btf_log_size); | |
5491 | if (err) | |
5492 | goto errout_free; | |
69b693f0 MKL |
5493 | |
5494 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
5495 | if (!btf) { | |
5496 | err = -ENOMEM; | |
5497 | goto errout; | |
5498 | } | |
f80442a4 MKL |
5499 | env->btf = btf; |
5500 | ||
47a71c1f | 5501 | data = kvmalloc(attr->btf_size, GFP_KERNEL | __GFP_NOWARN); |
69b693f0 MKL |
5502 | if (!data) { |
5503 | err = -ENOMEM; | |
5504 | goto errout; | |
5505 | } | |
5506 | ||
5507 | btf->data = data; | |
47a71c1f | 5508 | btf->data_size = attr->btf_size; |
69b693f0 | 5509 | |
47a71c1f | 5510 | if (copy_from_bpfptr(data, btf_data, attr->btf_size)) { |
69b693f0 MKL |
5511 | err = -EFAULT; |
5512 | goto errout; | |
5513 | } | |
5514 | ||
4a6998af ML |
5515 | err = btf_parse_hdr(env); |
5516 | if (err) | |
5517 | goto errout; | |
5518 | ||
5519 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
5520 | ||
69b693f0 MKL |
5521 | err = btf_parse_str_sec(env); |
5522 | if (err) | |
5523 | goto errout; | |
5524 | ||
5525 | err = btf_parse_type_sec(env); | |
5526 | if (err) | |
5527 | goto errout; | |
5528 | ||
eb596b09 KKD |
5529 | err = btf_check_type_tags(env, btf, 1); |
5530 | if (err) | |
5531 | goto errout; | |
5532 | ||
bdcab414 | 5533 | struct_meta_tab = btf_parse_struct_metas(&env->log, btf); |
8ffa5cc1 KKD |
5534 | if (IS_ERR(struct_meta_tab)) { |
5535 | err = PTR_ERR(struct_meta_tab); | |
5536 | goto errout; | |
5537 | } | |
5538 | btf->struct_meta_tab = struct_meta_tab; | |
5539 | ||
865ce09a KKD |
5540 | if (struct_meta_tab) { |
5541 | int i; | |
5542 | ||
5543 | for (i = 0; i < struct_meta_tab->cnt; i++) { | |
5544 | err = btf_check_and_fixup_fields(btf, struct_meta_tab->types[i].record); | |
5545 | if (err < 0) | |
5546 | goto errout_meta; | |
5547 | } | |
5548 | } | |
5549 | ||
bdcab414 AN |
5550 | err = finalize_log(&env->log, uattr, uattr_size); |
5551 | if (err) | |
5552 | goto errout_free; | |
69b693f0 | 5553 | |
f80442a4 MKL |
5554 | btf_verifier_env_free(env); |
5555 | refcount_set(&btf->refcnt, 1); | |
5556 | return btf; | |
69b693f0 | 5557 | |
8ffa5cc1 KKD |
5558 | errout_meta: |
5559 | btf_free_struct_meta_tab(btf); | |
69b693f0 | 5560 | errout: |
bdcab414 AN |
5561 | /* overwrite err with -ENOSPC or -EFAULT */ |
5562 | ret = finalize_log(&env->log, uattr, uattr_size); | |
5563 | if (ret) | |
5564 | err = ret; | |
5565 | errout_free: | |
69b693f0 MKL |
5566 | btf_verifier_env_free(env); |
5567 | if (btf) | |
5568 | btf_free(btf); | |
5569 | return ERR_PTR(err); | |
5570 | } | |
b00b8dae | 5571 | |
90ceddcb FS |
5572 | extern char __weak __start_BTF[]; |
5573 | extern char __weak __stop_BTF[]; | |
91cc1a99 AS |
5574 | extern struct btf *btf_vmlinux; |
5575 | ||
5576 | #define BPF_MAP_TYPE(_id, _ops) | |
f2e10bff | 5577 | #define BPF_LINK_TYPE(_id, _name) |
91cc1a99 AS |
5578 | static union { |
5579 | struct bpf_ctx_convert { | |
5580 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
5581 | prog_ctx_type _id##_prog; \ | |
5582 | kern_ctx_type _id##_kern; | |
5583 | #include <linux/bpf_types.h> | |
5584 | #undef BPF_PROG_TYPE | |
5585 | } *__t; | |
5586 | /* 't' is written once under lock. Read many times. */ | |
5587 | const struct btf_type *t; | |
5588 | } bpf_ctx_convert; | |
5589 | enum { | |
5590 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
5591 | __ctx_convert##_id, | |
5592 | #include <linux/bpf_types.h> | |
5593 | #undef BPF_PROG_TYPE | |
ce27709b | 5594 | __ctx_convert_unused, /* to avoid empty enum in extreme .config */ |
91cc1a99 AS |
5595 | }; |
5596 | static u8 bpf_ctx_convert_map[] = { | |
5597 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
5598 | [_id] = __ctx_convert##_id, | |
5599 | #include <linux/bpf_types.h> | |
5600 | #undef BPF_PROG_TYPE | |
4c80c7bc | 5601 | 0, /* avoid empty array */ |
91cc1a99 AS |
5602 | }; |
5603 | #undef BPF_MAP_TYPE | |
f2e10bff | 5604 | #undef BPF_LINK_TYPE |
91cc1a99 | 5605 | |
00b85860 | 5606 | const struct btf_member * |
34747c41 | 5607 | btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf, |
51c39bb1 AS |
5608 | const struct btf_type *t, enum bpf_prog_type prog_type, |
5609 | int arg) | |
91cc1a99 AS |
5610 | { |
5611 | const struct btf_type *conv_struct; | |
5612 | const struct btf_type *ctx_struct; | |
5613 | const struct btf_member *ctx_type; | |
5614 | const char *tname, *ctx_tname; | |
5615 | ||
5616 | conv_struct = bpf_ctx_convert.t; | |
5617 | if (!conv_struct) { | |
5618 | bpf_log(log, "btf_vmlinux is malformed\n"); | |
5619 | return NULL; | |
5620 | } | |
5621 | t = btf_type_by_id(btf, t->type); | |
5622 | while (btf_type_is_modifier(t)) | |
5623 | t = btf_type_by_id(btf, t->type); | |
5624 | if (!btf_type_is_struct(t)) { | |
5625 | /* Only pointer to struct is supported for now. | |
5626 | * That means that BPF_PROG_TYPE_TRACEPOINT with BTF | |
5627 | * is not supported yet. | |
5628 | * BPF_PROG_TYPE_RAW_TRACEPOINT is fine. | |
5629 | */ | |
91cc1a99 AS |
5630 | return NULL; |
5631 | } | |
5632 | tname = btf_name_by_offset(btf, t->name_off); | |
5633 | if (!tname) { | |
51c39bb1 | 5634 | bpf_log(log, "arg#%d struct doesn't have a name\n", arg); |
91cc1a99 AS |
5635 | return NULL; |
5636 | } | |
5637 | /* prog_type is valid bpf program type. No need for bounds check. */ | |
5638 | ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2; | |
5639 | /* ctx_struct is a pointer to prog_ctx_type in vmlinux. | |
5640 | * Like 'struct __sk_buff' | |
5641 | */ | |
5642 | ctx_struct = btf_type_by_id(btf_vmlinux, ctx_type->type); | |
5643 | if (!ctx_struct) | |
5644 | /* should not happen */ | |
5645 | return NULL; | |
d384dce2 | 5646 | again: |
91cc1a99 AS |
5647 | ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_struct->name_off); |
5648 | if (!ctx_tname) { | |
5649 | /* should not happen */ | |
5650 | bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n"); | |
5651 | return NULL; | |
5652 | } | |
5653 | /* only compare that prog's ctx type name is the same as | |
5654 | * kernel expects. No need to compare field by field. | |
5655 | * It's ok for bpf prog to do: | |
5656 | * struct __sk_buff {}; | |
5657 | * int socket_filter_bpf_prog(struct __sk_buff *skb) | |
5658 | * { // no fields of skb are ever used } | |
5659 | */ | |
2f464393 JK |
5660 | if (strcmp(ctx_tname, "__sk_buff") == 0 && strcmp(tname, "sk_buff") == 0) |
5661 | return ctx_type; | |
5662 | if (strcmp(ctx_tname, "xdp_md") == 0 && strcmp(tname, "xdp_buff") == 0) | |
5663 | return ctx_type; | |
d384dce2 AN |
5664 | if (strcmp(ctx_tname, tname)) { |
5665 | /* bpf_user_pt_regs_t is a typedef, so resolve it to | |
5666 | * underlying struct and check name again | |
5667 | */ | |
5668 | if (!btf_type_is_modifier(ctx_struct)) | |
5669 | return NULL; | |
5670 | while (btf_type_is_modifier(ctx_struct)) | |
5671 | ctx_struct = btf_type_by_id(btf_vmlinux, ctx_struct->type); | |
5672 | goto again; | |
5673 | } | |
91cc1a99 AS |
5674 | return ctx_type; |
5675 | } | |
8580ac94 | 5676 | |
5b92a28a AS |
5677 | static int btf_translate_to_vmlinux(struct bpf_verifier_log *log, |
5678 | struct btf *btf, | |
5679 | const struct btf_type *t, | |
51c39bb1 AS |
5680 | enum bpf_prog_type prog_type, |
5681 | int arg) | |
5b92a28a AS |
5682 | { |
5683 | const struct btf_member *prog_ctx_type, *kern_ctx_type; | |
5684 | ||
51c39bb1 | 5685 | prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type, arg); |
5b92a28a AS |
5686 | if (!prog_ctx_type) |
5687 | return -ENOENT; | |
5688 | kern_ctx_type = prog_ctx_type + 1; | |
5689 | return kern_ctx_type->type; | |
5690 | } | |
5691 | ||
fd264ca0 YS |
5692 | int get_kern_ctx_btf_id(struct bpf_verifier_log *log, enum bpf_prog_type prog_type) |
5693 | { | |
5694 | const struct btf_member *kctx_member; | |
5695 | const struct btf_type *conv_struct; | |
5696 | const struct btf_type *kctx_type; | |
5697 | u32 kctx_type_id; | |
5698 | ||
5699 | conv_struct = bpf_ctx_convert.t; | |
5700 | /* get member for kernel ctx type */ | |
5701 | kctx_member = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2 + 1; | |
5702 | kctx_type_id = kctx_member->type; | |
5703 | kctx_type = btf_type_by_id(btf_vmlinux, kctx_type_id); | |
5704 | if (!btf_type_is_struct(kctx_type)) { | |
5705 | bpf_log(log, "kern ctx type id %u is not a struct\n", kctx_type_id); | |
5706 | return -EINVAL; | |
5707 | } | |
5708 | ||
5709 | return kctx_type_id; | |
5710 | } | |
5711 | ||
49f4e672 JO |
5712 | BTF_ID_LIST(bpf_ctx_convert_btf_id) |
5713 | BTF_ID(struct, bpf_ctx_convert) | |
5714 | ||
8580ac94 AS |
5715 | struct btf *btf_parse_vmlinux(void) |
5716 | { | |
5717 | struct btf_verifier_env *env = NULL; | |
5718 | struct bpf_verifier_log *log; | |
5719 | struct btf *btf = NULL; | |
49f4e672 | 5720 | int err; |
8580ac94 AS |
5721 | |
5722 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
5723 | if (!env) | |
5724 | return ERR_PTR(-ENOMEM); | |
5725 | ||
5726 | log = &env->log; | |
5727 | log->level = BPF_LOG_KERNEL; | |
5728 | ||
5729 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
5730 | if (!btf) { | |
5731 | err = -ENOMEM; | |
5732 | goto errout; | |
5733 | } | |
5734 | env->btf = btf; | |
5735 | ||
90ceddcb FS |
5736 | btf->data = __start_BTF; |
5737 | btf->data_size = __stop_BTF - __start_BTF; | |
53297220 AN |
5738 | btf->kernel_btf = true; |
5739 | snprintf(btf->name, sizeof(btf->name), "vmlinux"); | |
8580ac94 AS |
5740 | |
5741 | err = btf_parse_hdr(env); | |
5742 | if (err) | |
5743 | goto errout; | |
5744 | ||
5745 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
5746 | ||
5747 | err = btf_parse_str_sec(env); | |
5748 | if (err) | |
5749 | goto errout; | |
5750 | ||
5751 | err = btf_check_all_metas(env); | |
5752 | if (err) | |
5753 | goto errout; | |
5754 | ||
eb596b09 KKD |
5755 | err = btf_check_type_tags(env, btf, 1); |
5756 | if (err) | |
5757 | goto errout; | |
5758 | ||
a2d0d62f | 5759 | /* btf_parse_vmlinux() runs under bpf_verifier_lock */ |
49f4e672 | 5760 | bpf_ctx_convert.t = btf_type_by_id(btf, bpf_ctx_convert_btf_id[0]); |
91cc1a99 | 5761 | |
d3e42bb0 | 5762 | bpf_struct_ops_init(btf, log); |
27ae7997 | 5763 | |
8580ac94 | 5764 | refcount_set(&btf->refcnt, 1); |
53297220 AN |
5765 | |
5766 | err = btf_alloc_id(btf); | |
5767 | if (err) | |
5768 | goto errout; | |
5769 | ||
5770 | btf_verifier_env_free(env); | |
8580ac94 AS |
5771 | return btf; |
5772 | ||
5773 | errout: | |
5774 | btf_verifier_env_free(env); | |
5775 | if (btf) { | |
5776 | kvfree(btf->types); | |
5777 | kfree(btf); | |
5778 | } | |
5779 | return ERR_PTR(err); | |
5780 | } | |
5781 | ||
7112d127 AN |
5782 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
5783 | ||
36e68442 AN |
5784 | static struct btf *btf_parse_module(const char *module_name, const void *data, unsigned int data_size) |
5785 | { | |
5786 | struct btf_verifier_env *env = NULL; | |
5787 | struct bpf_verifier_log *log; | |
5788 | struct btf *btf = NULL, *base_btf; | |
5789 | int err; | |
5790 | ||
5791 | base_btf = bpf_get_btf_vmlinux(); | |
5792 | if (IS_ERR(base_btf)) | |
5793 | return base_btf; | |
5794 | if (!base_btf) | |
5795 | return ERR_PTR(-EINVAL); | |
5796 | ||
5797 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
5798 | if (!env) | |
5799 | return ERR_PTR(-ENOMEM); | |
5800 | ||
5801 | log = &env->log; | |
5802 | log->level = BPF_LOG_KERNEL; | |
5803 | ||
5804 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
5805 | if (!btf) { | |
5806 | err = -ENOMEM; | |
5807 | goto errout; | |
5808 | } | |
5809 | env->btf = btf; | |
5810 | ||
5811 | btf->base_btf = base_btf; | |
5812 | btf->start_id = base_btf->nr_types; | |
5813 | btf->start_str_off = base_btf->hdr.str_len; | |
5814 | btf->kernel_btf = true; | |
5815 | snprintf(btf->name, sizeof(btf->name), "%s", module_name); | |
5816 | ||
5817 | btf->data = kvmalloc(data_size, GFP_KERNEL | __GFP_NOWARN); | |
5818 | if (!btf->data) { | |
5819 | err = -ENOMEM; | |
5820 | goto errout; | |
5821 | } | |
5822 | memcpy(btf->data, data, data_size); | |
5823 | btf->data_size = data_size; | |
5824 | ||
5825 | err = btf_parse_hdr(env); | |
5826 | if (err) | |
5827 | goto errout; | |
5828 | ||
5829 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
5830 | ||
5831 | err = btf_parse_str_sec(env); | |
5832 | if (err) | |
5833 | goto errout; | |
5834 | ||
5835 | err = btf_check_all_metas(env); | |
5836 | if (err) | |
5837 | goto errout; | |
5838 | ||
eb596b09 KKD |
5839 | err = btf_check_type_tags(env, btf, btf_nr_types(base_btf)); |
5840 | if (err) | |
5841 | goto errout; | |
5842 | ||
36e68442 AN |
5843 | btf_verifier_env_free(env); |
5844 | refcount_set(&btf->refcnt, 1); | |
5845 | return btf; | |
5846 | ||
5847 | errout: | |
5848 | btf_verifier_env_free(env); | |
5849 | if (btf) { | |
5850 | kvfree(btf->data); | |
5851 | kvfree(btf->types); | |
5852 | kfree(btf); | |
5853 | } | |
5854 | return ERR_PTR(err); | |
5855 | } | |
5856 | ||
7112d127 AN |
5857 | #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */ |
5858 | ||
5b92a28a AS |
5859 | struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog) |
5860 | { | |
3aac1ead | 5861 | struct bpf_prog *tgt_prog = prog->aux->dst_prog; |
5b92a28a | 5862 | |
22dc4a0f | 5863 | if (tgt_prog) |
5b92a28a | 5864 | return tgt_prog->aux->btf; |
22dc4a0f AN |
5865 | else |
5866 | return prog->aux->attach_btf; | |
5b92a28a AS |
5867 | } |
5868 | ||
bb6728d7 | 5869 | static bool is_int_ptr(struct btf *btf, const struct btf_type *t) |
84ad7a7a | 5870 | { |
91f2dc68 FZ |
5871 | /* skip modifiers */ |
5872 | t = btf_type_skip_modifiers(btf, t->type, NULL); | |
84ad7a7a | 5873 | |
bb6728d7 | 5874 | return btf_type_is_int(t); |
84ad7a7a JO |
5875 | } |
5876 | ||
720e6a43 YS |
5877 | static u32 get_ctx_arg_idx(struct btf *btf, const struct btf_type *func_proto, |
5878 | int off) | |
5879 | { | |
5880 | const struct btf_param *args; | |
5881 | const struct btf_type *t; | |
5882 | u32 offset = 0, nr_args; | |
5883 | int i; | |
5884 | ||
5885 | if (!func_proto) | |
5886 | return off / 8; | |
5887 | ||
5888 | nr_args = btf_type_vlen(func_proto); | |
5889 | args = (const struct btf_param *)(func_proto + 1); | |
5890 | for (i = 0; i < nr_args; i++) { | |
5891 | t = btf_type_skip_modifiers(btf, args[i].type, NULL); | |
5892 | offset += btf_type_is_ptr(t) ? 8 : roundup(t->size, 8); | |
5893 | if (off < offset) | |
5894 | return i; | |
5895 | } | |
5896 | ||
5897 | t = btf_type_skip_modifiers(btf, func_proto->type, NULL); | |
5898 | offset += btf_type_is_ptr(t) ? 8 : roundup(t->size, 8); | |
5899 | if (off < offset) | |
5900 | return nr_args; | |
5901 | ||
5902 | return nr_args + 1; | |
5903 | } | |
5904 | ||
c6b0337f | 5905 | static bool prog_args_trusted(const struct bpf_prog *prog) |
3f00c523 | 5906 | { |
c6b0337f AS |
5907 | enum bpf_attach_type atype = prog->expected_attach_type; |
5908 | ||
5909 | switch (prog->type) { | |
5910 | case BPF_PROG_TYPE_TRACING: | |
5911 | return atype == BPF_TRACE_RAW_TP || atype == BPF_TRACE_ITER; | |
5912 | case BPF_PROG_TYPE_LSM: | |
c0c852dd | 5913 | return bpf_lsm_is_trusted(prog); |
c6b0337f AS |
5914 | case BPF_PROG_TYPE_STRUCT_OPS: |
5915 | return true; | |
5916 | default: | |
5917 | return false; | |
5918 | } | |
3f00c523 DV |
5919 | } |
5920 | ||
9e15db66 AS |
5921 | bool btf_ctx_access(int off, int size, enum bpf_access_type type, |
5922 | const struct bpf_prog *prog, | |
5923 | struct bpf_insn_access_aux *info) | |
5924 | { | |
38207291 | 5925 | const struct btf_type *t = prog->aux->attach_func_proto; |
3aac1ead | 5926 | struct bpf_prog *tgt_prog = prog->aux->dst_prog; |
5b92a28a | 5927 | struct btf *btf = bpf_prog_get_target_btf(prog); |
38207291 | 5928 | const char *tname = prog->aux->attach_func_name; |
9e15db66 | 5929 | struct bpf_verifier_log *log = info->log; |
9e15db66 | 5930 | const struct btf_param *args; |
c6f1bfe8 | 5931 | const char *tag_value; |
9e15db66 | 5932 | u32 nr_args, arg; |
3c32cc1b | 5933 | int i, ret; |
9e15db66 | 5934 | |
9e15db66 | 5935 | if (off % 8) { |
38207291 | 5936 | bpf_log(log, "func '%s' offset %d is not multiple of 8\n", |
9e15db66 AS |
5937 | tname, off); |
5938 | return false; | |
5939 | } | |
720e6a43 | 5940 | arg = get_ctx_arg_idx(btf, t, off); |
9e15db66 | 5941 | args = (const struct btf_param *)(t + 1); |
523a4cf4 DB |
5942 | /* if (t == NULL) Fall back to default BPF prog with |
5943 | * MAX_BPF_FUNC_REG_ARGS u64 arguments. | |
5944 | */ | |
5945 | nr_args = t ? btf_type_vlen(t) : MAX_BPF_FUNC_REG_ARGS; | |
38207291 MKL |
5946 | if (prog->aux->attach_btf_trace) { |
5947 | /* skip first 'void *__data' argument in btf_trace_##name typedef */ | |
5948 | args++; | |
5949 | nr_args--; | |
5950 | } | |
fec56f58 | 5951 | |
f50b49a0 KS |
5952 | if (arg > nr_args) { |
5953 | bpf_log(log, "func '%s' doesn't have %d-th argument\n", | |
5954 | tname, arg + 1); | |
5955 | return false; | |
5956 | } | |
5957 | ||
6ba43b76 | 5958 | if (arg == nr_args) { |
f50b49a0 | 5959 | switch (prog->expected_attach_type) { |
69fd337a | 5960 | case BPF_LSM_CGROUP: |
f50b49a0 KS |
5961 | case BPF_LSM_MAC: |
5962 | case BPF_TRACE_FEXIT: | |
9e4e01df KS |
5963 | /* When LSM programs are attached to void LSM hooks |
5964 | * they use FEXIT trampolines and when attached to | |
5965 | * int LSM hooks, they use MODIFY_RETURN trampolines. | |
5966 | * | |
5967 | * While the LSM programs are BPF_MODIFY_RETURN-like | |
5968 | * the check: | |
5969 | * | |
5970 | * if (ret_type != 'int') | |
5971 | * return -EINVAL; | |
5972 | * | |
5973 | * is _not_ done here. This is still safe as LSM hooks | |
5974 | * have only void and int return types. | |
5975 | */ | |
6ba43b76 KS |
5976 | if (!t) |
5977 | return true; | |
5978 | t = btf_type_by_id(btf, t->type); | |
f50b49a0 KS |
5979 | break; |
5980 | case BPF_MODIFY_RETURN: | |
6ba43b76 KS |
5981 | /* For now the BPF_MODIFY_RETURN can only be attached to |
5982 | * functions that return an int. | |
5983 | */ | |
5984 | if (!t) | |
5985 | return false; | |
5986 | ||
5987 | t = btf_type_skip_modifiers(btf, t->type, NULL); | |
a9b59159 | 5988 | if (!btf_type_is_small_int(t)) { |
6ba43b76 KS |
5989 | bpf_log(log, |
5990 | "ret type %s not allowed for fmod_ret\n", | |
571f9738 | 5991 | btf_type_str(t)); |
6ba43b76 KS |
5992 | return false; |
5993 | } | |
f50b49a0 KS |
5994 | break; |
5995 | default: | |
5996 | bpf_log(log, "func '%s' doesn't have %d-th argument\n", | |
5997 | tname, arg + 1); | |
5998 | return false; | |
6ba43b76 | 5999 | } |
fec56f58 | 6000 | } else { |
5b92a28a | 6001 | if (!t) |
523a4cf4 | 6002 | /* Default prog with MAX_BPF_FUNC_REG_ARGS args */ |
5b92a28a AS |
6003 | return true; |
6004 | t = btf_type_by_id(btf, args[arg].type); | |
9e15db66 | 6005 | } |
f50b49a0 | 6006 | |
9e15db66 AS |
6007 | /* skip modifiers */ |
6008 | while (btf_type_is_modifier(t)) | |
5b92a28a | 6009 | t = btf_type_by_id(btf, t->type); |
720e6a43 | 6010 | if (btf_type_is_small_int(t) || btf_is_any_enum(t) || __btf_type_is_struct(t)) |
9e15db66 AS |
6011 | /* accessing a scalar */ |
6012 | return true; | |
6013 | if (!btf_type_is_ptr(t)) { | |
6014 | bpf_log(log, | |
38207291 | 6015 | "func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n", |
9e15db66 | 6016 | tname, arg, |
5b92a28a | 6017 | __btf_name_by_offset(btf, t->name_off), |
571f9738 | 6018 | btf_type_str(t)); |
9e15db66 AS |
6019 | return false; |
6020 | } | |
afbf21dc YS |
6021 | |
6022 | /* check for PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL */ | |
6023 | for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { | |
6024 | const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; | |
c25b2ae1 | 6025 | u32 type, flag; |
afbf21dc | 6026 | |
c25b2ae1 HL |
6027 | type = base_type(ctx_arg_info->reg_type); |
6028 | flag = type_flag(ctx_arg_info->reg_type); | |
20b2aff4 | 6029 | if (ctx_arg_info->offset == off && type == PTR_TO_BUF && |
c25b2ae1 | 6030 | (flag & PTR_MAYBE_NULL)) { |
afbf21dc YS |
6031 | info->reg_type = ctx_arg_info->reg_type; |
6032 | return true; | |
6033 | } | |
6034 | } | |
6035 | ||
9e15db66 AS |
6036 | if (t->type == 0) |
6037 | /* This is a pointer to void. | |
6038 | * It is the same as scalar from the verifier safety pov. | |
6039 | * No further pointer walking is allowed. | |
6040 | */ | |
6041 | return true; | |
6042 | ||
bb6728d7 | 6043 | if (is_int_ptr(btf, t)) |
84ad7a7a JO |
6044 | return true; |
6045 | ||
9e15db66 | 6046 | /* this is a pointer to another type */ |
3c32cc1b YS |
6047 | for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { |
6048 | const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; | |
6049 | ||
6050 | if (ctx_arg_info->offset == off) { | |
d3621642 YS |
6051 | if (!ctx_arg_info->btf_id) { |
6052 | bpf_log(log,"invalid btf_id for context argument offset %u\n", off); | |
6053 | return false; | |
6054 | } | |
6055 | ||
3c32cc1b | 6056 | info->reg_type = ctx_arg_info->reg_type; |
22dc4a0f | 6057 | info->btf = btf_vmlinux; |
951cf368 YS |
6058 | info->btf_id = ctx_arg_info->btf_id; |
6059 | return true; | |
3c32cc1b YS |
6060 | } |
6061 | } | |
9e15db66 | 6062 | |
951cf368 | 6063 | info->reg_type = PTR_TO_BTF_ID; |
c6b0337f | 6064 | if (prog_args_trusted(prog)) |
3f00c523 DV |
6065 | info->reg_type |= PTR_TRUSTED; |
6066 | ||
5b92a28a | 6067 | if (tgt_prog) { |
43bc2874 THJ |
6068 | enum bpf_prog_type tgt_type; |
6069 | ||
6070 | if (tgt_prog->type == BPF_PROG_TYPE_EXT) | |
6071 | tgt_type = tgt_prog->aux->saved_dst_prog_type; | |
6072 | else | |
6073 | tgt_type = tgt_prog->type; | |
6074 | ||
6075 | ret = btf_translate_to_vmlinux(log, btf, t, tgt_type, arg); | |
5b92a28a | 6076 | if (ret > 0) { |
22dc4a0f | 6077 | info->btf = btf_vmlinux; |
5b92a28a AS |
6078 | info->btf_id = ret; |
6079 | return true; | |
6080 | } else { | |
6081 | return false; | |
6082 | } | |
6083 | } | |
275517ff | 6084 | |
22dc4a0f | 6085 | info->btf = btf; |
275517ff | 6086 | info->btf_id = t->type; |
5b92a28a | 6087 | t = btf_type_by_id(btf, t->type); |
c6f1bfe8 YS |
6088 | |
6089 | if (btf_type_is_type_tag(t)) { | |
6090 | tag_value = __btf_name_by_offset(btf, t->name_off); | |
6091 | if (strcmp(tag_value, "user") == 0) | |
6092 | info->reg_type |= MEM_USER; | |
5844101a HL |
6093 | if (strcmp(tag_value, "percpu") == 0) |
6094 | info->reg_type |= MEM_PERCPU; | |
c6f1bfe8 YS |
6095 | } |
6096 | ||
9e15db66 | 6097 | /* skip modifiers */ |
275517ff MKL |
6098 | while (btf_type_is_modifier(t)) { |
6099 | info->btf_id = t->type; | |
5b92a28a | 6100 | t = btf_type_by_id(btf, t->type); |
275517ff | 6101 | } |
9e15db66 AS |
6102 | if (!btf_type_is_struct(t)) { |
6103 | bpf_log(log, | |
38207291 | 6104 | "func '%s' arg%d type %s is not a struct\n", |
571f9738 | 6105 | tname, arg, btf_type_str(t)); |
9e15db66 AS |
6106 | return false; |
6107 | } | |
38207291 | 6108 | bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n", |
571f9738 | 6109 | tname, arg, info->btf_id, btf_type_str(t), |
5b92a28a | 6110 | __btf_name_by_offset(btf, t->name_off)); |
9e15db66 AS |
6111 | return true; |
6112 | } | |
6113 | ||
1c6d28a6 JO |
6114 | enum bpf_struct_walk_result { |
6115 | /* < 0 error */ | |
6116 | WALK_SCALAR = 0, | |
6117 | WALK_PTR, | |
6118 | WALK_STRUCT, | |
6119 | }; | |
6120 | ||
22dc4a0f | 6121 | static int btf_struct_walk(struct bpf_verifier_log *log, const struct btf *btf, |
1c6d28a6 | 6122 | const struct btf_type *t, int off, int size, |
63260df1 AS |
6123 | u32 *next_btf_id, enum bpf_type_flag *flag, |
6124 | const char **field_name) | |
9e15db66 | 6125 | { |
7e3617a7 MKL |
6126 | u32 i, moff, mtrue_end, msize = 0, total_nelems = 0; |
6127 | const struct btf_type *mtype, *elem_type = NULL; | |
9e15db66 | 6128 | const struct btf_member *member; |
c6f1bfe8 | 6129 | const char *tname, *mname, *tag_value; |
1c6d28a6 | 6130 | u32 vlen, elem_id, mid; |
9e15db66 | 6131 | |
6fcd486b | 6132 | *flag = 0; |
9e15db66 | 6133 | again: |
22dc4a0f | 6134 | tname = __btf_name_by_offset(btf, t->name_off); |
9e15db66 | 6135 | if (!btf_type_is_struct(t)) { |
275517ff | 6136 | bpf_log(log, "Type '%s' is not a struct\n", tname); |
9e15db66 AS |
6137 | return -EINVAL; |
6138 | } | |
6139 | ||
9c5f8a10 | 6140 | vlen = btf_type_vlen(t); |
976aba00 | 6141 | if (off + size > t->size) { |
9c5f8a10 YS |
6142 | /* If the last element is a variable size array, we may |
6143 | * need to relax the rule. | |
6144 | */ | |
6145 | struct btf_array *array_elem; | |
6146 | ||
6147 | if (vlen == 0) | |
6148 | goto error; | |
6149 | ||
6150 | member = btf_type_member(t) + vlen - 1; | |
22dc4a0f | 6151 | mtype = btf_type_skip_modifiers(btf, member->type, |
9c5f8a10 YS |
6152 | NULL); |
6153 | if (!btf_type_is_array(mtype)) | |
6154 | goto error; | |
6155 | ||
6156 | array_elem = (struct btf_array *)(mtype + 1); | |
6157 | if (array_elem->nelems != 0) | |
6158 | goto error; | |
6159 | ||
8293eb99 | 6160 | moff = __btf_member_bit_offset(t, member) / 8; |
9c5f8a10 YS |
6161 | if (off < moff) |
6162 | goto error; | |
6163 | ||
2569c7b8 | 6164 | /* allow structure and integer */ |
22dc4a0f | 6165 | t = btf_type_skip_modifiers(btf, array_elem->type, |
dafe58fc | 6166 | NULL); |
2569c7b8 FZ |
6167 | |
6168 | if (btf_type_is_int(t)) | |
6169 | return WALK_SCALAR; | |
6170 | ||
dafe58fc | 6171 | if (!btf_type_is_struct(t)) |
9c5f8a10 YS |
6172 | goto error; |
6173 | ||
dafe58fc JO |
6174 | off = (off - moff) % t->size; |
6175 | goto again; | |
9c5f8a10 YS |
6176 | |
6177 | error: | |
976aba00 MKL |
6178 | bpf_log(log, "access beyond struct %s at off %u size %u\n", |
6179 | tname, off, size); | |
6180 | return -EACCES; | |
6181 | } | |
9e15db66 | 6182 | |
976aba00 | 6183 | for_each_member(i, t, member) { |
7e3617a7 | 6184 | /* offset of the field in bytes */ |
8293eb99 | 6185 | moff = __btf_member_bit_offset(t, member) / 8; |
7e3617a7 | 6186 | if (off + size <= moff) |
9e15db66 AS |
6187 | /* won't find anything, field is already too far */ |
6188 | break; | |
976aba00 | 6189 | |
8293eb99 AS |
6190 | if (__btf_member_bitfield_size(t, member)) { |
6191 | u32 end_bit = __btf_member_bit_offset(t, member) + | |
6192 | __btf_member_bitfield_size(t, member); | |
976aba00 MKL |
6193 | |
6194 | /* off <= moff instead of off == moff because clang | |
6195 | * does not generate a BTF member for anonymous | |
6196 | * bitfield like the ":16" here: | |
6197 | * struct { | |
6198 | * int :16; | |
6199 | * int x:8; | |
6200 | * }; | |
6201 | */ | |
6202 | if (off <= moff && | |
6203 | BITS_ROUNDUP_BYTES(end_bit) <= off + size) | |
1c6d28a6 | 6204 | return WALK_SCALAR; |
976aba00 MKL |
6205 | |
6206 | /* off may be accessing a following member | |
6207 | * | |
6208 | * or | |
6209 | * | |
6210 | * Doing partial access at either end of this | |
6211 | * bitfield. Continue on this case also to | |
6212 | * treat it as not accessing this bitfield | |
6213 | * and eventually error out as field not | |
6214 | * found to keep it simple. | |
6215 | * It could be relaxed if there was a legit | |
6216 | * partial access case later. | |
6217 | */ | |
6218 | continue; | |
6219 | } | |
6220 | ||
7e3617a7 MKL |
6221 | /* In case of "off" is pointing to holes of a struct */ |
6222 | if (off < moff) | |
976aba00 | 6223 | break; |
9e15db66 AS |
6224 | |
6225 | /* type of the field */ | |
1c6d28a6 | 6226 | mid = member->type; |
22dc4a0f AN |
6227 | mtype = btf_type_by_id(btf, member->type); |
6228 | mname = __btf_name_by_offset(btf, member->name_off); | |
9e15db66 | 6229 | |
22dc4a0f | 6230 | mtype = __btf_resolve_size(btf, mtype, &msize, |
1c6d28a6 JO |
6231 | &elem_type, &elem_id, &total_nelems, |
6232 | &mid); | |
7e3617a7 | 6233 | if (IS_ERR(mtype)) { |
9e15db66 AS |
6234 | bpf_log(log, "field %s doesn't have size\n", mname); |
6235 | return -EFAULT; | |
6236 | } | |
7e3617a7 MKL |
6237 | |
6238 | mtrue_end = moff + msize; | |
6239 | if (off >= mtrue_end) | |
9e15db66 AS |
6240 | /* no overlap with member, keep iterating */ |
6241 | continue; | |
7e3617a7 MKL |
6242 | |
6243 | if (btf_type_is_array(mtype)) { | |
6244 | u32 elem_idx; | |
6245 | ||
6298399b | 6246 | /* __btf_resolve_size() above helps to |
7e3617a7 MKL |
6247 | * linearize a multi-dimensional array. |
6248 | * | |
6249 | * The logic here is treating an array | |
6250 | * in a struct as the following way: | |
6251 | * | |
6252 | * struct outer { | |
6253 | * struct inner array[2][2]; | |
6254 | * }; | |
6255 | * | |
6256 | * looks like: | |
6257 | * | |
6258 | * struct outer { | |
6259 | * struct inner array_elem0; | |
6260 | * struct inner array_elem1; | |
6261 | * struct inner array_elem2; | |
6262 | * struct inner array_elem3; | |
6263 | * }; | |
6264 | * | |
6265 | * When accessing outer->array[1][0], it moves | |
6266 | * moff to "array_elem2", set mtype to | |
6267 | * "struct inner", and msize also becomes | |
6268 | * sizeof(struct inner). Then most of the | |
6269 | * remaining logic will fall through without | |
6270 | * caring the current member is an array or | |
6271 | * not. | |
6272 | * | |
6273 | * Unlike mtype/msize/moff, mtrue_end does not | |
6274 | * change. The naming difference ("_true") tells | |
6275 | * that it is not always corresponding to | |
6276 | * the current mtype/msize/moff. | |
6277 | * It is the true end of the current | |
6278 | * member (i.e. array in this case). That | |
6279 | * will allow an int array to be accessed like | |
6280 | * a scratch space, | |
6281 | * i.e. allow access beyond the size of | |
6282 | * the array's element as long as it is | |
6283 | * within the mtrue_end boundary. | |
6284 | */ | |
6285 | ||
6286 | /* skip empty array */ | |
6287 | if (moff == mtrue_end) | |
6288 | continue; | |
6289 | ||
6290 | msize /= total_nelems; | |
6291 | elem_idx = (off - moff) / msize; | |
6292 | moff += elem_idx * msize; | |
6293 | mtype = elem_type; | |
1c6d28a6 | 6294 | mid = elem_id; |
7e3617a7 MKL |
6295 | } |
6296 | ||
9e15db66 AS |
6297 | /* the 'off' we're looking for is either equal to start |
6298 | * of this field or inside of this struct | |
6299 | */ | |
6300 | if (btf_type_is_struct(mtype)) { | |
6fcd486b AS |
6301 | if (BTF_INFO_KIND(mtype->info) == BTF_KIND_UNION && |
6302 | btf_type_vlen(mtype) != 1) | |
6303 | /* | |
6304 | * walking unions yields untrusted pointers | |
6305 | * with exception of __bpf_md_ptr and other | |
6306 | * unions with a single member | |
6307 | */ | |
6308 | *flag |= PTR_UNTRUSTED; | |
6309 | ||
9e15db66 AS |
6310 | /* our field must be inside that union or struct */ |
6311 | t = mtype; | |
6312 | ||
1c6d28a6 JO |
6313 | /* return if the offset matches the member offset */ |
6314 | if (off == moff) { | |
6315 | *next_btf_id = mid; | |
6316 | return WALK_STRUCT; | |
6317 | } | |
6318 | ||
9e15db66 | 6319 | /* adjust offset we're looking for */ |
7e3617a7 | 6320 | off -= moff; |
9e15db66 AS |
6321 | goto again; |
6322 | } | |
9e15db66 AS |
6323 | |
6324 | if (btf_type_is_ptr(mtype)) { | |
c6f1bfe8 YS |
6325 | const struct btf_type *stype, *t; |
6326 | enum bpf_type_flag tmp_flag = 0; | |
257af63d | 6327 | u32 id; |
9e15db66 | 6328 | |
7e3617a7 MKL |
6329 | if (msize != size || off != moff) { |
6330 | bpf_log(log, | |
6331 | "cannot access ptr member %s with moff %u in struct %s with off %u size %u\n", | |
6332 | mname, moff, tname, off, size); | |
6333 | return -EACCES; | |
6334 | } | |
c6f1bfe8 | 6335 | |
5844101a | 6336 | /* check type tag */ |
c6f1bfe8 YS |
6337 | t = btf_type_by_id(btf, mtype->type); |
6338 | if (btf_type_is_type_tag(t)) { | |
6339 | tag_value = __btf_name_by_offset(btf, t->name_off); | |
5844101a | 6340 | /* check __user tag */ |
c6f1bfe8 YS |
6341 | if (strcmp(tag_value, "user") == 0) |
6342 | tmp_flag = MEM_USER; | |
5844101a HL |
6343 | /* check __percpu tag */ |
6344 | if (strcmp(tag_value, "percpu") == 0) | |
6345 | tmp_flag = MEM_PERCPU; | |
9bb00b28 YS |
6346 | /* check __rcu tag */ |
6347 | if (strcmp(tag_value, "rcu") == 0) | |
6348 | tmp_flag = MEM_RCU; | |
c6f1bfe8 YS |
6349 | } |
6350 | ||
22dc4a0f | 6351 | stype = btf_type_skip_modifiers(btf, mtype->type, &id); |
9e15db66 | 6352 | if (btf_type_is_struct(stype)) { |
257af63d | 6353 | *next_btf_id = id; |
6fcd486b | 6354 | *flag |= tmp_flag; |
63260df1 AS |
6355 | if (field_name) |
6356 | *field_name = mname; | |
1c6d28a6 | 6357 | return WALK_PTR; |
9e15db66 AS |
6358 | } |
6359 | } | |
7e3617a7 MKL |
6360 | |
6361 | /* Allow more flexible access within an int as long as | |
6362 | * it is within mtrue_end. | |
6363 | * Since mtrue_end could be the end of an array, | |
6364 | * that also allows using an array of int as a scratch | |
6365 | * space. e.g. skb->cb[]. | |
6366 | */ | |
6367 | if (off + size > mtrue_end) { | |
6368 | bpf_log(log, | |
6369 | "access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n", | |
6370 | mname, mtrue_end, tname, off, size); | |
6371 | return -EACCES; | |
6372 | } | |
6373 | ||
1c6d28a6 | 6374 | return WALK_SCALAR; |
9e15db66 AS |
6375 | } |
6376 | bpf_log(log, "struct %s doesn't have field at offset %d\n", tname, off); | |
6377 | return -EINVAL; | |
6378 | } | |
6379 | ||
6728aea7 KKD |
6380 | int btf_struct_access(struct bpf_verifier_log *log, |
6381 | const struct bpf_reg_state *reg, | |
6382 | int off, int size, enum bpf_access_type atype __maybe_unused, | |
63260df1 AS |
6383 | u32 *next_btf_id, enum bpf_type_flag *flag, |
6384 | const char **field_name) | |
1c6d28a6 | 6385 | { |
6728aea7 | 6386 | const struct btf *btf = reg->btf; |
c6f1bfe8 | 6387 | enum bpf_type_flag tmp_flag = 0; |
6728aea7 KKD |
6388 | const struct btf_type *t; |
6389 | u32 id = reg->btf_id; | |
1c6d28a6 | 6390 | int err; |
1c6d28a6 | 6391 | |
8ffa5cc1 KKD |
6392 | while (type_is_alloc(reg->type)) { |
6393 | struct btf_struct_meta *meta; | |
6394 | struct btf_record *rec; | |
6395 | int i; | |
6396 | ||
6397 | meta = btf_find_struct_meta(btf, id); | |
6398 | if (!meta) | |
6399 | break; | |
6400 | rec = meta->record; | |
6401 | for (i = 0; i < rec->cnt; i++) { | |
6402 | struct btf_field *field = &rec->fields[i]; | |
6403 | u32 offset = field->offset; | |
6404 | if (off < offset + btf_field_type_size(field->type) && offset < off + size) { | |
6405 | bpf_log(log, | |
6406 | "direct access to %s is disallowed\n", | |
6407 | btf_field_type_name(field->type)); | |
6408 | return -EACCES; | |
6409 | } | |
6410 | } | |
6411 | break; | |
6412 | } | |
6413 | ||
6728aea7 | 6414 | t = btf_type_by_id(btf, id); |
1c6d28a6 | 6415 | do { |
63260df1 | 6416 | err = btf_struct_walk(log, btf, t, off, size, &id, &tmp_flag, field_name); |
1c6d28a6 JO |
6417 | |
6418 | switch (err) { | |
6419 | case WALK_PTR: | |
282de143 KKD |
6420 | /* For local types, the destination register cannot |
6421 | * become a pointer again. | |
6422 | */ | |
6423 | if (type_is_alloc(reg->type)) | |
6424 | return SCALAR_VALUE; | |
1c6d28a6 JO |
6425 | /* If we found the pointer or scalar on t+off, |
6426 | * we're done. | |
6427 | */ | |
6428 | *next_btf_id = id; | |
c6f1bfe8 | 6429 | *flag = tmp_flag; |
1c6d28a6 JO |
6430 | return PTR_TO_BTF_ID; |
6431 | case WALK_SCALAR: | |
6432 | return SCALAR_VALUE; | |
6433 | case WALK_STRUCT: | |
6434 | /* We found nested struct, so continue the search | |
6435 | * by diving in it. At this point the offset is | |
6436 | * aligned with the new type, so set it to 0. | |
6437 | */ | |
22dc4a0f | 6438 | t = btf_type_by_id(btf, id); |
1c6d28a6 JO |
6439 | off = 0; |
6440 | break; | |
6441 | default: | |
6442 | /* It's either error or unknown return value.. | |
6443 | * scream and leave. | |
6444 | */ | |
6445 | if (WARN_ONCE(err > 0, "unknown btf_struct_walk return value")) | |
6446 | return -EINVAL; | |
6447 | return err; | |
6448 | } | |
6449 | } while (t); | |
6450 | ||
6451 | return -EINVAL; | |
6452 | } | |
6453 | ||
22dc4a0f AN |
6454 | /* Check that two BTF types, each specified as an BTF object + id, are exactly |
6455 | * the same. Trivial ID check is not enough due to module BTFs, because we can | |
6456 | * end up with two different module BTFs, but IDs point to the common type in | |
6457 | * vmlinux BTF. | |
6458 | */ | |
00b85860 KKD |
6459 | bool btf_types_are_same(const struct btf *btf1, u32 id1, |
6460 | const struct btf *btf2, u32 id2) | |
22dc4a0f AN |
6461 | { |
6462 | if (id1 != id2) | |
6463 | return false; | |
6464 | if (btf1 == btf2) | |
6465 | return true; | |
6466 | return btf_type_by_id(btf1, id1) == btf_type_by_id(btf2, id2); | |
6467 | } | |
6468 | ||
faaf4a79 | 6469 | bool btf_struct_ids_match(struct bpf_verifier_log *log, |
22dc4a0f | 6470 | const struct btf *btf, u32 id, int off, |
2ab3b380 KKD |
6471 | const struct btf *need_btf, u32 need_type_id, |
6472 | bool strict) | |
faaf4a79 JO |
6473 | { |
6474 | const struct btf_type *type; | |
c6f1bfe8 | 6475 | enum bpf_type_flag flag; |
faaf4a79 JO |
6476 | int err; |
6477 | ||
6478 | /* Are we already done? */ | |
22dc4a0f | 6479 | if (off == 0 && btf_types_are_same(btf, id, need_btf, need_type_id)) |
faaf4a79 | 6480 | return true; |
2ab3b380 KKD |
6481 | /* In case of strict type match, we do not walk struct, the top level |
6482 | * type match must succeed. When strict is true, off should have already | |
6483 | * been 0. | |
6484 | */ | |
6485 | if (strict) | |
6486 | return false; | |
faaf4a79 | 6487 | again: |
22dc4a0f | 6488 | type = btf_type_by_id(btf, id); |
faaf4a79 JO |
6489 | if (!type) |
6490 | return false; | |
63260df1 | 6491 | err = btf_struct_walk(log, btf, type, off, 1, &id, &flag, NULL); |
faaf4a79 JO |
6492 | if (err != WALK_STRUCT) |
6493 | return false; | |
6494 | ||
6495 | /* We found nested struct object. If it matches | |
6496 | * the requested ID, we're done. Otherwise let's | |
6497 | * continue the search with offset 0 in the new | |
6498 | * type. | |
6499 | */ | |
22dc4a0f | 6500 | if (!btf_types_are_same(btf, id, need_btf, need_type_id)) { |
faaf4a79 JO |
6501 | off = 0; |
6502 | goto again; | |
6503 | } | |
6504 | ||
6505 | return true; | |
6506 | } | |
6507 | ||
fec56f58 | 6508 | static int __get_type_size(struct btf *btf, u32 btf_id, |
a00ed843 | 6509 | const struct btf_type **ret_type) |
fec56f58 AS |
6510 | { |
6511 | const struct btf_type *t; | |
6512 | ||
a00ed843 | 6513 | *ret_type = btf_type_by_id(btf, 0); |
fec56f58 AS |
6514 | if (!btf_id) |
6515 | /* void */ | |
6516 | return 0; | |
6517 | t = btf_type_by_id(btf, btf_id); | |
6518 | while (t && btf_type_is_modifier(t)) | |
6519 | t = btf_type_by_id(btf, t->type); | |
a00ed843 | 6520 | if (!t) |
fec56f58 | 6521 | return -EINVAL; |
a00ed843 | 6522 | *ret_type = t; |
fec56f58 AS |
6523 | if (btf_type_is_ptr(t)) |
6524 | /* kernel size of pointer. Not BPF's size of pointer*/ | |
6525 | return sizeof(void *); | |
720e6a43 | 6526 | if (btf_type_is_int(t) || btf_is_any_enum(t) || __btf_type_is_struct(t)) |
fec56f58 | 6527 | return t->size; |
fec56f58 AS |
6528 | return -EINVAL; |
6529 | } | |
6530 | ||
49f67f39 IL |
6531 | static u8 __get_type_fmodel_flags(const struct btf_type *t) |
6532 | { | |
6533 | u8 flags = 0; | |
6534 | ||
6535 | if (__btf_type_is_struct(t)) | |
6536 | flags |= BTF_FMODEL_STRUCT_ARG; | |
6537 | if (btf_type_is_signed_int(t)) | |
6538 | flags |= BTF_FMODEL_SIGNED_ARG; | |
6539 | ||
6540 | return flags; | |
6541 | } | |
6542 | ||
fec56f58 AS |
6543 | int btf_distill_func_proto(struct bpf_verifier_log *log, |
6544 | struct btf *btf, | |
6545 | const struct btf_type *func, | |
6546 | const char *tname, | |
6547 | struct btf_func_model *m) | |
6548 | { | |
6549 | const struct btf_param *args; | |
6550 | const struct btf_type *t; | |
6551 | u32 i, nargs; | |
6552 | int ret; | |
6553 | ||
5b92a28a AS |
6554 | if (!func) { |
6555 | /* BTF function prototype doesn't match the verifier types. | |
523a4cf4 | 6556 | * Fall back to MAX_BPF_FUNC_REG_ARGS u64 args. |
5b92a28a | 6557 | */ |
720e6a43 | 6558 | for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++) { |
5b92a28a | 6559 | m->arg_size[i] = 8; |
720e6a43 YS |
6560 | m->arg_flags[i] = 0; |
6561 | } | |
5b92a28a | 6562 | m->ret_size = 8; |
49f67f39 | 6563 | m->ret_flags = 0; |
523a4cf4 | 6564 | m->nr_args = MAX_BPF_FUNC_REG_ARGS; |
5b92a28a AS |
6565 | return 0; |
6566 | } | |
fec56f58 AS |
6567 | args = (const struct btf_param *)(func + 1); |
6568 | nargs = btf_type_vlen(func); | |
c29a4920 | 6569 | if (nargs > MAX_BPF_FUNC_ARGS) { |
fec56f58 AS |
6570 | bpf_log(log, |
6571 | "The function %s has %d arguments. Too many.\n", | |
6572 | tname, nargs); | |
6573 | return -EINVAL; | |
6574 | } | |
6575 | ret = __get_type_size(btf, func->type, &t); | |
720e6a43 | 6576 | if (ret < 0 || __btf_type_is_struct(t)) { |
fec56f58 AS |
6577 | bpf_log(log, |
6578 | "The function %s return type %s is unsupported.\n", | |
571f9738 | 6579 | tname, btf_type_str(t)); |
fec56f58 AS |
6580 | return -EINVAL; |
6581 | } | |
6582 | m->ret_size = ret; | |
49f67f39 | 6583 | m->ret_flags = __get_type_fmodel_flags(t); |
fec56f58 AS |
6584 | |
6585 | for (i = 0; i < nargs; i++) { | |
31379397 JO |
6586 | if (i == nargs - 1 && args[i].type == 0) { |
6587 | bpf_log(log, | |
6588 | "The function %s with variable args is unsupported.\n", | |
6589 | tname); | |
6590 | return -EINVAL; | |
6591 | } | |
fec56f58 | 6592 | ret = __get_type_size(btf, args[i].type, &t); |
720e6a43 YS |
6593 | |
6594 | /* No support of struct argument size greater than 16 bytes */ | |
6595 | if (ret < 0 || ret > 16) { | |
fec56f58 AS |
6596 | bpf_log(log, |
6597 | "The function %s arg%d type %s is unsupported.\n", | |
571f9738 | 6598 | tname, i, btf_type_str(t)); |
fec56f58 AS |
6599 | return -EINVAL; |
6600 | } | |
31379397 JO |
6601 | if (ret == 0) { |
6602 | bpf_log(log, | |
6603 | "The function %s has malformed void argument.\n", | |
6604 | tname); | |
6605 | return -EINVAL; | |
6606 | } | |
fec56f58 | 6607 | m->arg_size[i] = ret; |
49f67f39 | 6608 | m->arg_flags[i] = __get_type_fmodel_flags(t); |
fec56f58 AS |
6609 | } |
6610 | m->nr_args = nargs; | |
6611 | return 0; | |
6612 | } | |
6613 | ||
be8704ff AS |
6614 | /* Compare BTFs of two functions assuming only scalars and pointers to context. |
6615 | * t1 points to BTF_KIND_FUNC in btf1 | |
6616 | * t2 points to BTF_KIND_FUNC in btf2 | |
6617 | * Returns: | |
6618 | * EINVAL - function prototype mismatch | |
6619 | * EFAULT - verifier bug | |
6620 | * 0 - 99% match. The last 1% is validated by the verifier. | |
6621 | */ | |
2bf0eb9b HY |
6622 | static int btf_check_func_type_match(struct bpf_verifier_log *log, |
6623 | struct btf *btf1, const struct btf_type *t1, | |
6624 | struct btf *btf2, const struct btf_type *t2) | |
be8704ff AS |
6625 | { |
6626 | const struct btf_param *args1, *args2; | |
6627 | const char *fn1, *fn2, *s1, *s2; | |
6628 | u32 nargs1, nargs2, i; | |
6629 | ||
6630 | fn1 = btf_name_by_offset(btf1, t1->name_off); | |
6631 | fn2 = btf_name_by_offset(btf2, t2->name_off); | |
6632 | ||
6633 | if (btf_func_linkage(t1) != BTF_FUNC_GLOBAL) { | |
6634 | bpf_log(log, "%s() is not a global function\n", fn1); | |
6635 | return -EINVAL; | |
6636 | } | |
6637 | if (btf_func_linkage(t2) != BTF_FUNC_GLOBAL) { | |
6638 | bpf_log(log, "%s() is not a global function\n", fn2); | |
6639 | return -EINVAL; | |
6640 | } | |
6641 | ||
6642 | t1 = btf_type_by_id(btf1, t1->type); | |
6643 | if (!t1 || !btf_type_is_func_proto(t1)) | |
6644 | return -EFAULT; | |
6645 | t2 = btf_type_by_id(btf2, t2->type); | |
6646 | if (!t2 || !btf_type_is_func_proto(t2)) | |
6647 | return -EFAULT; | |
6648 | ||
6649 | args1 = (const struct btf_param *)(t1 + 1); | |
6650 | nargs1 = btf_type_vlen(t1); | |
6651 | args2 = (const struct btf_param *)(t2 + 1); | |
6652 | nargs2 = btf_type_vlen(t2); | |
6653 | ||
6654 | if (nargs1 != nargs2) { | |
6655 | bpf_log(log, "%s() has %d args while %s() has %d args\n", | |
6656 | fn1, nargs1, fn2, nargs2); | |
6657 | return -EINVAL; | |
6658 | } | |
6659 | ||
6660 | t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); | |
6661 | t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); | |
6662 | if (t1->info != t2->info) { | |
6663 | bpf_log(log, | |
6664 | "Return type %s of %s() doesn't match type %s of %s()\n", | |
6665 | btf_type_str(t1), fn1, | |
6666 | btf_type_str(t2), fn2); | |
6667 | return -EINVAL; | |
6668 | } | |
6669 | ||
6670 | for (i = 0; i < nargs1; i++) { | |
6671 | t1 = btf_type_skip_modifiers(btf1, args1[i].type, NULL); | |
6672 | t2 = btf_type_skip_modifiers(btf2, args2[i].type, NULL); | |
6673 | ||
6674 | if (t1->info != t2->info) { | |
6675 | bpf_log(log, "arg%d in %s() is %s while %s() has %s\n", | |
6676 | i, fn1, btf_type_str(t1), | |
6677 | fn2, btf_type_str(t2)); | |
6678 | return -EINVAL; | |
6679 | } | |
6680 | if (btf_type_has_size(t1) && t1->size != t2->size) { | |
6681 | bpf_log(log, | |
6682 | "arg%d in %s() has size %d while %s() has %d\n", | |
6683 | i, fn1, t1->size, | |
6684 | fn2, t2->size); | |
6685 | return -EINVAL; | |
6686 | } | |
6687 | ||
6688 | /* global functions are validated with scalars and pointers | |
6689 | * to context only. And only global functions can be replaced. | |
6690 | * Hence type check only those types. | |
6691 | */ | |
6089fb32 | 6692 | if (btf_type_is_int(t1) || btf_is_any_enum(t1)) |
be8704ff AS |
6693 | continue; |
6694 | if (!btf_type_is_ptr(t1)) { | |
6695 | bpf_log(log, | |
6696 | "arg%d in %s() has unrecognized type\n", | |
6697 | i, fn1); | |
6698 | return -EINVAL; | |
6699 | } | |
6700 | t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); | |
6701 | t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); | |
6702 | if (!btf_type_is_struct(t1)) { | |
6703 | bpf_log(log, | |
6704 | "arg%d in %s() is not a pointer to context\n", | |
6705 | i, fn1); | |
6706 | return -EINVAL; | |
6707 | } | |
6708 | if (!btf_type_is_struct(t2)) { | |
6709 | bpf_log(log, | |
6710 | "arg%d in %s() is not a pointer to context\n", | |
6711 | i, fn2); | |
6712 | return -EINVAL; | |
6713 | } | |
6714 | /* This is an optional check to make program writing easier. | |
6715 | * Compare names of structs and report an error to the user. | |
6716 | * btf_prepare_func_args() already checked that t2 struct | |
6717 | * is a context type. btf_prepare_func_args() will check | |
6718 | * later that t1 struct is a context type as well. | |
6719 | */ | |
6720 | s1 = btf_name_by_offset(btf1, t1->name_off); | |
6721 | s2 = btf_name_by_offset(btf2, t2->name_off); | |
6722 | if (strcmp(s1, s2)) { | |
6723 | bpf_log(log, | |
6724 | "arg%d %s(struct %s *) doesn't match %s(struct %s *)\n", | |
6725 | i, fn1, s1, fn2, s2); | |
6726 | return -EINVAL; | |
6727 | } | |
6728 | } | |
6729 | return 0; | |
6730 | } | |
6731 | ||
6732 | /* Compare BTFs of given program with BTF of target program */ | |
efc68158 | 6733 | int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog, |
be8704ff AS |
6734 | struct btf *btf2, const struct btf_type *t2) |
6735 | { | |
6736 | struct btf *btf1 = prog->aux->btf; | |
6737 | const struct btf_type *t1; | |
6738 | u32 btf_id = 0; | |
6739 | ||
6740 | if (!prog->aux->func_info) { | |
efc68158 | 6741 | bpf_log(log, "Program extension requires BTF\n"); |
be8704ff AS |
6742 | return -EINVAL; |
6743 | } | |
6744 | ||
6745 | btf_id = prog->aux->func_info[0].type_id; | |
6746 | if (!btf_id) | |
6747 | return -EFAULT; | |
6748 | ||
6749 | t1 = btf_type_by_id(btf1, btf_id); | |
6750 | if (!t1 || !btf_type_is_func(t1)) | |
6751 | return -EFAULT; | |
6752 | ||
efc68158 | 6753 | return btf_check_func_type_match(log, btf1, t1, btf2, t2); |
be8704ff AS |
6754 | } |
6755 | ||
34747c41 MKL |
6756 | static int btf_check_func_arg_match(struct bpf_verifier_env *env, |
6757 | const struct btf *btf, u32 func_id, | |
6758 | struct bpf_reg_state *regs, | |
a4703e31 | 6759 | bool ptr_to_mem_ok, |
95f2f26f | 6760 | bool processing_call) |
8c1b6e69 | 6761 | { |
f858c2b2 | 6762 | enum bpf_prog_type prog_type = resolve_prog_type(env->prog); |
8c1b6e69 | 6763 | struct bpf_verifier_log *log = &env->log; |
34747c41 | 6764 | const char *func_name, *ref_tname; |
e5069b9c | 6765 | const struct btf_type *t, *ref_t; |
34747c41 | 6766 | const struct btf_param *args; |
00b85860 KKD |
6767 | u32 i, nargs, ref_id; |
6768 | int ret; | |
8c1b6e69 | 6769 | |
34747c41 | 6770 | t = btf_type_by_id(btf, func_id); |
8c1b6e69 | 6771 | if (!t || !btf_type_is_func(t)) { |
51c39bb1 | 6772 | /* These checks were already done by the verifier while loading |
e6ac2450 | 6773 | * struct bpf_func_info or in add_kfunc_call(). |
51c39bb1 | 6774 | */ |
34747c41 MKL |
6775 | bpf_log(log, "BTF of func_id %u doesn't point to KIND_FUNC\n", |
6776 | func_id); | |
51c39bb1 | 6777 | return -EFAULT; |
8c1b6e69 | 6778 | } |
34747c41 | 6779 | func_name = btf_name_by_offset(btf, t->name_off); |
8c1b6e69 AS |
6780 | |
6781 | t = btf_type_by_id(btf, t->type); | |
6782 | if (!t || !btf_type_is_func_proto(t)) { | |
34747c41 | 6783 | bpf_log(log, "Invalid BTF of func %s\n", func_name); |
51c39bb1 | 6784 | return -EFAULT; |
8c1b6e69 AS |
6785 | } |
6786 | args = (const struct btf_param *)(t + 1); | |
6787 | nargs = btf_type_vlen(t); | |
523a4cf4 | 6788 | if (nargs > MAX_BPF_FUNC_REG_ARGS) { |
34747c41 | 6789 | bpf_log(log, "Function %s has %d > %d args\n", func_name, nargs, |
523a4cf4 | 6790 | MAX_BPF_FUNC_REG_ARGS); |
34747c41 | 6791 | return -EINVAL; |
8c1b6e69 | 6792 | } |
e5069b9c | 6793 | |
8c1b6e69 AS |
6794 | /* check that BTF function arguments match actual types that the |
6795 | * verifier sees. | |
6796 | */ | |
6797 | for (i = 0; i < nargs; i++) { | |
8f14852e | 6798 | enum bpf_arg_type arg_type = ARG_DONTCARE; |
34747c41 MKL |
6799 | u32 regno = i + 1; |
6800 | struct bpf_reg_state *reg = ®s[regno]; | |
feb4adfa | 6801 | |
34747c41 MKL |
6802 | t = btf_type_skip_modifiers(btf, args[i].type, NULL); |
6803 | if (btf_type_is_scalar(t)) { | |
feb4adfa | 6804 | if (reg->type == SCALAR_VALUE) |
8c1b6e69 | 6805 | continue; |
34747c41 MKL |
6806 | bpf_log(log, "R%d is not a scalar\n", regno); |
6807 | return -EINVAL; | |
8c1b6e69 | 6808 | } |
34747c41 MKL |
6809 | |
6810 | if (!btf_type_is_ptr(t)) { | |
6811 | bpf_log(log, "Unrecognized arg#%d type %s\n", | |
6812 | i, btf_type_str(t)); | |
6813 | return -EINVAL; | |
6814 | } | |
6815 | ||
e6ac2450 | 6816 | ref_t = btf_type_skip_modifiers(btf, t->type, &ref_id); |
34747c41 | 6817 | ref_tname = btf_name_by_offset(btf, ref_t->name_off); |
655efe50 | 6818 | |
8f14852e | 6819 | ret = check_func_arg_reg_off(env, reg, regno, arg_type); |
655efe50 KKD |
6820 | if (ret < 0) |
6821 | return ret; | |
6822 | ||
00b85860 | 6823 | if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) { |
3363bd0c KKD |
6824 | /* If function expects ctx type in BTF check that caller |
6825 | * is passing PTR_TO_CTX. | |
6826 | */ | |
6827 | if (reg->type != PTR_TO_CTX) { | |
6828 | bpf_log(log, | |
6829 | "arg#%d expected pointer to ctx, but got %s\n", | |
6830 | i, btf_type_str(t)); | |
6831 | return -EINVAL; | |
6832 | } | |
95f2f26f | 6833 | } else if (ptr_to_mem_ok && processing_call) { |
34747c41 MKL |
6834 | const struct btf_type *resolve_ret; |
6835 | u32 type_size; | |
e5069b9c | 6836 | |
34747c41 MKL |
6837 | resolve_ret = btf_resolve_size(btf, ref_t, &type_size); |
6838 | if (IS_ERR(resolve_ret)) { | |
e5069b9c | 6839 | bpf_log(log, |
34747c41 MKL |
6840 | "arg#%d reference type('%s %s') size cannot be determined: %ld\n", |
6841 | i, btf_type_str(ref_t), ref_tname, | |
6842 | PTR_ERR(resolve_ret)); | |
6843 | return -EINVAL; | |
e5069b9c DB |
6844 | } |
6845 | ||
34747c41 MKL |
6846 | if (check_mem_reg(env, reg, regno, type_size)) |
6847 | return -EINVAL; | |
6848 | } else { | |
00b85860 KKD |
6849 | bpf_log(log, "reg type unsupported for arg#%d function %s#%d\n", i, |
6850 | func_name, func_id); | |
34747c41 | 6851 | return -EINVAL; |
8c1b6e69 | 6852 | } |
8c1b6e69 | 6853 | } |
34747c41 | 6854 | |
00b85860 | 6855 | return 0; |
34747c41 MKL |
6856 | } |
6857 | ||
95f2f26f | 6858 | /* Compare BTF of a function declaration with given bpf_reg_state. |
34747c41 MKL |
6859 | * Returns: |
6860 | * EFAULT - there is a verifier bug. Abort verification. | |
6861 | * EINVAL - there is a type mismatch or BTF is not available. | |
6862 | * 0 - BTF matches with what bpf_reg_state expects. | |
6863 | * Only PTR_TO_CTX and SCALAR_VALUE states are recognized. | |
6864 | */ | |
6865 | int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog, | |
6866 | struct bpf_reg_state *regs) | |
6867 | { | |
6868 | struct bpf_prog *prog = env->prog; | |
6869 | struct btf *btf = prog->aux->btf; | |
6870 | bool is_global; | |
6871 | u32 btf_id; | |
6872 | int err; | |
6873 | ||
6874 | if (!prog->aux->func_info) | |
6875 | return -EINVAL; | |
6876 | ||
6877 | btf_id = prog->aux->func_info[subprog].type_id; | |
6878 | if (!btf_id) | |
6879 | return -EFAULT; | |
6880 | ||
6881 | if (prog->aux->func_info_aux[subprog].unreliable) | |
6882 | return -EINVAL; | |
6883 | ||
6884 | is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL; | |
00b85860 | 6885 | err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, false); |
95f2f26f BT |
6886 | |
6887 | /* Compiler optimizations can remove arguments from static functions | |
6888 | * or mismatched type can be passed into a global function. | |
6889 | * In such cases mark the function as unreliable from BTF point of view. | |
6890 | */ | |
6891 | if (err) | |
6892 | prog->aux->func_info_aux[subprog].unreliable = true; | |
6893 | return err; | |
6894 | } | |
6895 | ||
6896 | /* Compare BTF of a function call with given bpf_reg_state. | |
6897 | * Returns: | |
6898 | * EFAULT - there is a verifier bug. Abort verification. | |
6899 | * EINVAL - there is a type mismatch or BTF is not available. | |
6900 | * 0 - BTF matches with what bpf_reg_state expects. | |
6901 | * Only PTR_TO_CTX and SCALAR_VALUE states are recognized. | |
6902 | * | |
6903 | * NOTE: the code is duplicated from btf_check_subprog_arg_match() | |
6904 | * because btf_check_func_arg_match() is still doing both. Once that | |
6905 | * function is split in 2, we can call from here btf_check_subprog_arg_match() | |
6906 | * first, and then treat the calling part in a new code path. | |
6907 | */ | |
6908 | int btf_check_subprog_call(struct bpf_verifier_env *env, int subprog, | |
6909 | struct bpf_reg_state *regs) | |
6910 | { | |
6911 | struct bpf_prog *prog = env->prog; | |
6912 | struct btf *btf = prog->aux->btf; | |
6913 | bool is_global; | |
6914 | u32 btf_id; | |
6915 | int err; | |
6916 | ||
6917 | if (!prog->aux->func_info) | |
6918 | return -EINVAL; | |
6919 | ||
6920 | btf_id = prog->aux->func_info[subprog].type_id; | |
6921 | if (!btf_id) | |
6922 | return -EFAULT; | |
6923 | ||
6924 | if (prog->aux->func_info_aux[subprog].unreliable) | |
6925 | return -EINVAL; | |
6926 | ||
6927 | is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL; | |
00b85860 | 6928 | err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, true); |
34747c41 | 6929 | |
51c39bb1 AS |
6930 | /* Compiler optimizations can remove arguments from static functions |
6931 | * or mismatched type can be passed into a global function. | |
6932 | * In such cases mark the function as unreliable from BTF point of view. | |
6933 | */ | |
34747c41 MKL |
6934 | if (err) |
6935 | prog->aux->func_info_aux[subprog].unreliable = true; | |
6936 | return err; | |
51c39bb1 AS |
6937 | } |
6938 | ||
6939 | /* Convert BTF of a function into bpf_reg_state if possible | |
6940 | * Returns: | |
6941 | * EFAULT - there is a verifier bug. Abort verification. | |
6942 | * EINVAL - cannot convert BTF. | |
6943 | * 0 - Successfully converted BTF into bpf_reg_state | |
6944 | * (either PTR_TO_CTX or SCALAR_VALUE). | |
6945 | */ | |
6946 | int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog, | |
feb4adfa | 6947 | struct bpf_reg_state *regs) |
51c39bb1 AS |
6948 | { |
6949 | struct bpf_verifier_log *log = &env->log; | |
6950 | struct bpf_prog *prog = env->prog; | |
be8704ff | 6951 | enum bpf_prog_type prog_type = prog->type; |
51c39bb1 AS |
6952 | struct btf *btf = prog->aux->btf; |
6953 | const struct btf_param *args; | |
e5069b9c | 6954 | const struct btf_type *t, *ref_t; |
51c39bb1 AS |
6955 | u32 i, nargs, btf_id; |
6956 | const char *tname; | |
6957 | ||
6958 | if (!prog->aux->func_info || | |
6959 | prog->aux->func_info_aux[subprog].linkage != BTF_FUNC_GLOBAL) { | |
6960 | bpf_log(log, "Verifier bug\n"); | |
6961 | return -EFAULT; | |
6962 | } | |
6963 | ||
6964 | btf_id = prog->aux->func_info[subprog].type_id; | |
6965 | if (!btf_id) { | |
6966 | bpf_log(log, "Global functions need valid BTF\n"); | |
6967 | return -EFAULT; | |
6968 | } | |
6969 | ||
6970 | t = btf_type_by_id(btf, btf_id); | |
6971 | if (!t || !btf_type_is_func(t)) { | |
6972 | /* These checks were already done by the verifier while loading | |
6973 | * struct bpf_func_info | |
6974 | */ | |
6975 | bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n", | |
6976 | subprog); | |
6977 | return -EFAULT; | |
6978 | } | |
6979 | tname = btf_name_by_offset(btf, t->name_off); | |
6980 | ||
6981 | if (log->level & BPF_LOG_LEVEL) | |
6982 | bpf_log(log, "Validating %s() func#%d...\n", | |
6983 | tname, subprog); | |
6984 | ||
6985 | if (prog->aux->func_info_aux[subprog].unreliable) { | |
6986 | bpf_log(log, "Verifier bug in function %s()\n", tname); | |
6987 | return -EFAULT; | |
6988 | } | |
be8704ff | 6989 | if (prog_type == BPF_PROG_TYPE_EXT) |
3aac1ead | 6990 | prog_type = prog->aux->dst_prog->type; |
51c39bb1 AS |
6991 | |
6992 | t = btf_type_by_id(btf, t->type); | |
6993 | if (!t || !btf_type_is_func_proto(t)) { | |
6994 | bpf_log(log, "Invalid type of function %s()\n", tname); | |
6995 | return -EFAULT; | |
6996 | } | |
6997 | args = (const struct btf_param *)(t + 1); | |
6998 | nargs = btf_type_vlen(t); | |
523a4cf4 DB |
6999 | if (nargs > MAX_BPF_FUNC_REG_ARGS) { |
7000 | bpf_log(log, "Global function %s() with %d > %d args. Buggy compiler.\n", | |
7001 | tname, nargs, MAX_BPF_FUNC_REG_ARGS); | |
51c39bb1 AS |
7002 | return -EINVAL; |
7003 | } | |
7004 | /* check that function returns int */ | |
7005 | t = btf_type_by_id(btf, t->type); | |
7006 | while (btf_type_is_modifier(t)) | |
7007 | t = btf_type_by_id(btf, t->type); | |
6089fb32 | 7008 | if (!btf_type_is_int(t) && !btf_is_any_enum(t)) { |
51c39bb1 AS |
7009 | bpf_log(log, |
7010 | "Global function %s() doesn't return scalar. Only those are supported.\n", | |
7011 | tname); | |
7012 | return -EINVAL; | |
7013 | } | |
7014 | /* Convert BTF function arguments into verifier types. | |
7015 | * Only PTR_TO_CTX and SCALAR are supported atm. | |
7016 | */ | |
7017 | for (i = 0; i < nargs; i++) { | |
feb4adfa DB |
7018 | struct bpf_reg_state *reg = ®s[i + 1]; |
7019 | ||
51c39bb1 AS |
7020 | t = btf_type_by_id(btf, args[i].type); |
7021 | while (btf_type_is_modifier(t)) | |
7022 | t = btf_type_by_id(btf, t->type); | |
6089fb32 | 7023 | if (btf_type_is_int(t) || btf_is_any_enum(t)) { |
feb4adfa | 7024 | reg->type = SCALAR_VALUE; |
51c39bb1 AS |
7025 | continue; |
7026 | } | |
e5069b9c DB |
7027 | if (btf_type_is_ptr(t)) { |
7028 | if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) { | |
7029 | reg->type = PTR_TO_CTX; | |
7030 | continue; | |
7031 | } | |
7032 | ||
7033 | t = btf_type_skip_modifiers(btf, t->type, NULL); | |
7034 | ||
7035 | ref_t = btf_resolve_size(btf, t, ®->mem_size); | |
7036 | if (IS_ERR(ref_t)) { | |
7037 | bpf_log(log, | |
7038 | "arg#%d reference type('%s %s') size cannot be determined: %ld\n", | |
7039 | i, btf_type_str(t), btf_name_by_offset(btf, t->name_off), | |
7040 | PTR_ERR(ref_t)); | |
7041 | return -EINVAL; | |
7042 | } | |
7043 | ||
cf9f2f8d | 7044 | reg->type = PTR_TO_MEM | PTR_MAYBE_NULL; |
e5069b9c DB |
7045 | reg->id = ++env->id_gen; |
7046 | ||
51c39bb1 AS |
7047 | continue; |
7048 | } | |
7049 | bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n", | |
571f9738 | 7050 | i, btf_type_str(t), tname); |
51c39bb1 AS |
7051 | return -EINVAL; |
7052 | } | |
8c1b6e69 AS |
7053 | return 0; |
7054 | } | |
7055 | ||
31d0bc81 AM |
7056 | static void btf_type_show(const struct btf *btf, u32 type_id, void *obj, |
7057 | struct btf_show *show) | |
7058 | { | |
7059 | const struct btf_type *t = btf_type_by_id(btf, type_id); | |
7060 | ||
7061 | show->btf = btf; | |
7062 | memset(&show->state, 0, sizeof(show->state)); | |
7063 | memset(&show->obj, 0, sizeof(show->obj)); | |
7064 | ||
7065 | btf_type_ops(t)->show(btf, t, type_id, obj, 0, show); | |
7066 | } | |
7067 | ||
7068 | static void btf_seq_show(struct btf_show *show, const char *fmt, | |
7069 | va_list args) | |
7070 | { | |
7071 | seq_vprintf((struct seq_file *)show->target, fmt, args); | |
7072 | } | |
7073 | ||
eb411377 AM |
7074 | int btf_type_seq_show_flags(const struct btf *btf, u32 type_id, |
7075 | void *obj, struct seq_file *m, u64 flags) | |
31d0bc81 AM |
7076 | { |
7077 | struct btf_show sseq; | |
7078 | ||
7079 | sseq.target = m; | |
7080 | sseq.showfn = btf_seq_show; | |
7081 | sseq.flags = flags; | |
7082 | ||
7083 | btf_type_show(btf, type_id, obj, &sseq); | |
7084 | ||
7085 | return sseq.state.status; | |
7086 | } | |
7087 | ||
b00b8dae MKL |
7088 | void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj, |
7089 | struct seq_file *m) | |
7090 | { | |
31d0bc81 AM |
7091 | (void) btf_type_seq_show_flags(btf, type_id, obj, m, |
7092 | BTF_SHOW_NONAME | BTF_SHOW_COMPACT | | |
7093 | BTF_SHOW_ZERO | BTF_SHOW_UNSAFE); | |
7094 | } | |
7095 | ||
7096 | struct btf_show_snprintf { | |
7097 | struct btf_show show; | |
7098 | int len_left; /* space left in string */ | |
7099 | int len; /* length we would have written */ | |
7100 | }; | |
7101 | ||
7102 | static void btf_snprintf_show(struct btf_show *show, const char *fmt, | |
7103 | va_list args) | |
7104 | { | |
7105 | struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show; | |
7106 | int len; | |
7107 | ||
7108 | len = vsnprintf(show->target, ssnprintf->len_left, fmt, args); | |
7109 | ||
7110 | if (len < 0) { | |
7111 | ssnprintf->len_left = 0; | |
7112 | ssnprintf->len = len; | |
58250ae3 | 7113 | } else if (len >= ssnprintf->len_left) { |
31d0bc81 AM |
7114 | /* no space, drive on to get length we would have written */ |
7115 | ssnprintf->len_left = 0; | |
7116 | ssnprintf->len += len; | |
7117 | } else { | |
7118 | ssnprintf->len_left -= len; | |
7119 | ssnprintf->len += len; | |
7120 | show->target += len; | |
7121 | } | |
7122 | } | |
7123 | ||
7124 | int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj, | |
7125 | char *buf, int len, u64 flags) | |
7126 | { | |
7127 | struct btf_show_snprintf ssnprintf; | |
7128 | ||
7129 | ssnprintf.show.target = buf; | |
7130 | ssnprintf.show.flags = flags; | |
7131 | ssnprintf.show.showfn = btf_snprintf_show; | |
7132 | ssnprintf.len_left = len; | |
7133 | ssnprintf.len = 0; | |
7134 | ||
7135 | btf_type_show(btf, type_id, obj, (struct btf_show *)&ssnprintf); | |
7136 | ||
c561d110 | 7137 | /* If we encountered an error, return it. */ |
31d0bc81 AM |
7138 | if (ssnprintf.show.state.status) |
7139 | return ssnprintf.show.state.status; | |
b00b8dae | 7140 | |
31d0bc81 AM |
7141 | /* Otherwise return length we would have written */ |
7142 | return ssnprintf.len; | |
b00b8dae | 7143 | } |
f56a653c | 7144 | |
3481e64b QM |
7145 | #ifdef CONFIG_PROC_FS |
7146 | static void bpf_btf_show_fdinfo(struct seq_file *m, struct file *filp) | |
7147 | { | |
7148 | const struct btf *btf = filp->private_data; | |
7149 | ||
7150 | seq_printf(m, "btf_id:\t%u\n", btf->id); | |
7151 | } | |
7152 | #endif | |
7153 | ||
f56a653c MKL |
7154 | static int btf_release(struct inode *inode, struct file *filp) |
7155 | { | |
7156 | btf_put(filp->private_data); | |
7157 | return 0; | |
7158 | } | |
7159 | ||
60197cfb | 7160 | const struct file_operations btf_fops = { |
3481e64b QM |
7161 | #ifdef CONFIG_PROC_FS |
7162 | .show_fdinfo = bpf_btf_show_fdinfo, | |
7163 | #endif | |
f56a653c MKL |
7164 | .release = btf_release, |
7165 | }; | |
7166 | ||
78958fca MKL |
7167 | static int __btf_new_fd(struct btf *btf) |
7168 | { | |
7169 | return anon_inode_getfd("btf", &btf_fops, btf, O_RDONLY | O_CLOEXEC); | |
7170 | } | |
7171 | ||
47a71c1f | 7172 | int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size) |
f56a653c MKL |
7173 | { |
7174 | struct btf *btf; | |
78958fca | 7175 | int ret; |
f56a653c | 7176 | |
47a71c1f | 7177 | btf = btf_parse(attr, uattr, uattr_size); |
f56a653c MKL |
7178 | if (IS_ERR(btf)) |
7179 | return PTR_ERR(btf); | |
7180 | ||
78958fca MKL |
7181 | ret = btf_alloc_id(btf); |
7182 | if (ret) { | |
7183 | btf_free(btf); | |
7184 | return ret; | |
7185 | } | |
7186 | ||
7187 | /* | |
7188 | * The BTF ID is published to the userspace. | |
7189 | * All BTF free must go through call_rcu() from | |
7190 | * now on (i.e. free by calling btf_put()). | |
7191 | */ | |
7192 | ||
7193 | ret = __btf_new_fd(btf); | |
7194 | if (ret < 0) | |
f56a653c MKL |
7195 | btf_put(btf); |
7196 | ||
78958fca | 7197 | return ret; |
f56a653c MKL |
7198 | } |
7199 | ||
7200 | struct btf *btf_get_by_fd(int fd) | |
7201 | { | |
7202 | struct btf *btf; | |
7203 | struct fd f; | |
7204 | ||
7205 | f = fdget(fd); | |
7206 | ||
7207 | if (!f.file) | |
7208 | return ERR_PTR(-EBADF); | |
7209 | ||
7210 | if (f.file->f_op != &btf_fops) { | |
7211 | fdput(f); | |
7212 | return ERR_PTR(-EINVAL); | |
7213 | } | |
7214 | ||
7215 | btf = f.file->private_data; | |
78958fca | 7216 | refcount_inc(&btf->refcnt); |
f56a653c MKL |
7217 | fdput(f); |
7218 | ||
7219 | return btf; | |
7220 | } | |
60197cfb MKL |
7221 | |
7222 | int btf_get_info_by_fd(const struct btf *btf, | |
7223 | const union bpf_attr *attr, | |
7224 | union bpf_attr __user *uattr) | |
7225 | { | |
62dab84c | 7226 | struct bpf_btf_info __user *uinfo; |
5c6f2588 | 7227 | struct bpf_btf_info info; |
62dab84c MKL |
7228 | u32 info_copy, btf_copy; |
7229 | void __user *ubtf; | |
53297220 AN |
7230 | char __user *uname; |
7231 | u32 uinfo_len, uname_len, name_len; | |
7232 | int ret = 0; | |
60197cfb | 7233 | |
62dab84c MKL |
7234 | uinfo = u64_to_user_ptr(attr->info.info); |
7235 | uinfo_len = attr->info.info_len; | |
7236 | ||
7237 | info_copy = min_t(u32, uinfo_len, sizeof(info)); | |
5c6f2588 | 7238 | memset(&info, 0, sizeof(info)); |
62dab84c MKL |
7239 | if (copy_from_user(&info, uinfo, info_copy)) |
7240 | return -EFAULT; | |
7241 | ||
7242 | info.id = btf->id; | |
7243 | ubtf = u64_to_user_ptr(info.btf); | |
7244 | btf_copy = min_t(u32, btf->data_size, info.btf_size); | |
7245 | if (copy_to_user(ubtf, btf->data, btf_copy)) | |
7246 | return -EFAULT; | |
7247 | info.btf_size = btf->data_size; | |
7248 | ||
53297220 AN |
7249 | info.kernel_btf = btf->kernel_btf; |
7250 | ||
7251 | uname = u64_to_user_ptr(info.name); | |
7252 | uname_len = info.name_len; | |
7253 | if (!uname ^ !uname_len) | |
7254 | return -EINVAL; | |
7255 | ||
7256 | name_len = strlen(btf->name); | |
7257 | info.name_len = name_len; | |
7258 | ||
7259 | if (uname) { | |
7260 | if (uname_len >= name_len + 1) { | |
7261 | if (copy_to_user(uname, btf->name, name_len + 1)) | |
7262 | return -EFAULT; | |
7263 | } else { | |
7264 | char zero = '\0'; | |
7265 | ||
7266 | if (copy_to_user(uname, btf->name, uname_len - 1)) | |
7267 | return -EFAULT; | |
7268 | if (put_user(zero, uname + uname_len - 1)) | |
7269 | return -EFAULT; | |
7270 | /* let user-space know about too short buffer */ | |
7271 | ret = -ENOSPC; | |
7272 | } | |
7273 | } | |
7274 | ||
62dab84c MKL |
7275 | if (copy_to_user(uinfo, &info, info_copy) || |
7276 | put_user(info_copy, &uattr->info.info_len)) | |
60197cfb MKL |
7277 | return -EFAULT; |
7278 | ||
53297220 | 7279 | return ret; |
60197cfb | 7280 | } |
78958fca MKL |
7281 | |
7282 | int btf_get_fd_by_id(u32 id) | |
7283 | { | |
7284 | struct btf *btf; | |
7285 | int fd; | |
7286 | ||
7287 | rcu_read_lock(); | |
7288 | btf = idr_find(&btf_idr, id); | |
7289 | if (!btf || !refcount_inc_not_zero(&btf->refcnt)) | |
7290 | btf = ERR_PTR(-ENOENT); | |
7291 | rcu_read_unlock(); | |
7292 | ||
7293 | if (IS_ERR(btf)) | |
7294 | return PTR_ERR(btf); | |
7295 | ||
7296 | fd = __btf_new_fd(btf); | |
7297 | if (fd < 0) | |
7298 | btf_put(btf); | |
7299 | ||
7300 | return fd; | |
7301 | } | |
7302 | ||
22dc4a0f | 7303 | u32 btf_obj_id(const struct btf *btf) |
78958fca MKL |
7304 | { |
7305 | return btf->id; | |
7306 | } | |
eae2e83e | 7307 | |
290248a5 AN |
7308 | bool btf_is_kernel(const struct btf *btf) |
7309 | { | |
7310 | return btf->kernel_btf; | |
7311 | } | |
7312 | ||
541c3bad AN |
7313 | bool btf_is_module(const struct btf *btf) |
7314 | { | |
7315 | return btf->kernel_btf && strcmp(btf->name, "vmlinux") != 0; | |
7316 | } | |
7317 | ||
18688de2 KKD |
7318 | enum { |
7319 | BTF_MODULE_F_LIVE = (1 << 0), | |
7320 | }; | |
7321 | ||
36e68442 AN |
7322 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
7323 | struct btf_module { | |
7324 | struct list_head list; | |
7325 | struct module *module; | |
7326 | struct btf *btf; | |
7327 | struct bin_attribute *sysfs_attr; | |
18688de2 | 7328 | int flags; |
36e68442 AN |
7329 | }; |
7330 | ||
7331 | static LIST_HEAD(btf_modules); | |
7332 | static DEFINE_MUTEX(btf_module_mutex); | |
7333 | ||
7334 | static ssize_t | |
7335 | btf_module_read(struct file *file, struct kobject *kobj, | |
7336 | struct bin_attribute *bin_attr, | |
7337 | char *buf, loff_t off, size_t len) | |
7338 | { | |
7339 | const struct btf *btf = bin_attr->private; | |
7340 | ||
7341 | memcpy(buf, btf->data + off, len); | |
7342 | return len; | |
7343 | } | |
7344 | ||
1e89106d AS |
7345 | static void purge_cand_cache(struct btf *btf); |
7346 | ||
36e68442 AN |
7347 | static int btf_module_notify(struct notifier_block *nb, unsigned long op, |
7348 | void *module) | |
7349 | { | |
7350 | struct btf_module *btf_mod, *tmp; | |
7351 | struct module *mod = module; | |
7352 | struct btf *btf; | |
7353 | int err = 0; | |
7354 | ||
7355 | if (mod->btf_data_size == 0 || | |
18688de2 KKD |
7356 | (op != MODULE_STATE_COMING && op != MODULE_STATE_LIVE && |
7357 | op != MODULE_STATE_GOING)) | |
36e68442 AN |
7358 | goto out; |
7359 | ||
7360 | switch (op) { | |
7361 | case MODULE_STATE_COMING: | |
7362 | btf_mod = kzalloc(sizeof(*btf_mod), GFP_KERNEL); | |
7363 | if (!btf_mod) { | |
7364 | err = -ENOMEM; | |
7365 | goto out; | |
7366 | } | |
7367 | btf = btf_parse_module(mod->name, mod->btf_data, mod->btf_data_size); | |
7368 | if (IS_ERR(btf)) { | |
36e68442 | 7369 | kfree(btf_mod); |
9cb61e50 CB |
7370 | if (!IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) { |
7371 | pr_warn("failed to validate module [%s] BTF: %ld\n", | |
7372 | mod->name, PTR_ERR(btf)); | |
5e214f2e | 7373 | err = PTR_ERR(btf); |
9cb61e50 CB |
7374 | } else { |
7375 | pr_warn_once("Kernel module BTF mismatch detected, BTF debug info may be unavailable for some modules\n"); | |
7376 | } | |
36e68442 AN |
7377 | goto out; |
7378 | } | |
7379 | err = btf_alloc_id(btf); | |
7380 | if (err) { | |
7381 | btf_free(btf); | |
7382 | kfree(btf_mod); | |
7383 | goto out; | |
7384 | } | |
7385 | ||
1e89106d | 7386 | purge_cand_cache(NULL); |
36e68442 AN |
7387 | mutex_lock(&btf_module_mutex); |
7388 | btf_mod->module = module; | |
7389 | btf_mod->btf = btf; | |
7390 | list_add(&btf_mod->list, &btf_modules); | |
7391 | mutex_unlock(&btf_module_mutex); | |
7392 | ||
7393 | if (IS_ENABLED(CONFIG_SYSFS)) { | |
7394 | struct bin_attribute *attr; | |
7395 | ||
7396 | attr = kzalloc(sizeof(*attr), GFP_KERNEL); | |
7397 | if (!attr) | |
7398 | goto out; | |
7399 | ||
7400 | sysfs_bin_attr_init(attr); | |
7401 | attr->attr.name = btf->name; | |
7402 | attr->attr.mode = 0444; | |
7403 | attr->size = btf->data_size; | |
7404 | attr->private = btf; | |
7405 | attr->read = btf_module_read; | |
7406 | ||
7407 | err = sysfs_create_bin_file(btf_kobj, attr); | |
7408 | if (err) { | |
7409 | pr_warn("failed to register module [%s] BTF in sysfs: %d\n", | |
7410 | mod->name, err); | |
7411 | kfree(attr); | |
7412 | err = 0; | |
7413 | goto out; | |
7414 | } | |
7415 | ||
7416 | btf_mod->sysfs_attr = attr; | |
7417 | } | |
7418 | ||
18688de2 KKD |
7419 | break; |
7420 | case MODULE_STATE_LIVE: | |
7421 | mutex_lock(&btf_module_mutex); | |
7422 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
7423 | if (btf_mod->module != module) | |
7424 | continue; | |
7425 | ||
7426 | btf_mod->flags |= BTF_MODULE_F_LIVE; | |
7427 | break; | |
7428 | } | |
7429 | mutex_unlock(&btf_module_mutex); | |
36e68442 AN |
7430 | break; |
7431 | case MODULE_STATE_GOING: | |
7432 | mutex_lock(&btf_module_mutex); | |
7433 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
7434 | if (btf_mod->module != module) | |
7435 | continue; | |
7436 | ||
7437 | list_del(&btf_mod->list); | |
7438 | if (btf_mod->sysfs_attr) | |
7439 | sysfs_remove_bin_file(btf_kobj, btf_mod->sysfs_attr); | |
1e89106d | 7440 | purge_cand_cache(btf_mod->btf); |
36e68442 AN |
7441 | btf_put(btf_mod->btf); |
7442 | kfree(btf_mod->sysfs_attr); | |
7443 | kfree(btf_mod); | |
7444 | break; | |
7445 | } | |
7446 | mutex_unlock(&btf_module_mutex); | |
7447 | break; | |
7448 | } | |
7449 | out: | |
7450 | return notifier_from_errno(err); | |
7451 | } | |
7452 | ||
7453 | static struct notifier_block btf_module_nb = { | |
7454 | .notifier_call = btf_module_notify, | |
7455 | }; | |
7456 | ||
7457 | static int __init btf_module_init(void) | |
7458 | { | |
7459 | register_module_notifier(&btf_module_nb); | |
7460 | return 0; | |
7461 | } | |
7462 | ||
7463 | fs_initcall(btf_module_init); | |
7464 | #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */ | |
541c3bad AN |
7465 | |
7466 | struct module *btf_try_get_module(const struct btf *btf) | |
7467 | { | |
7468 | struct module *res = NULL; | |
7469 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES | |
7470 | struct btf_module *btf_mod, *tmp; | |
7471 | ||
7472 | mutex_lock(&btf_module_mutex); | |
7473 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
7474 | if (btf_mod->btf != btf) | |
7475 | continue; | |
7476 | ||
18688de2 KKD |
7477 | /* We must only consider module whose __init routine has |
7478 | * finished, hence we must check for BTF_MODULE_F_LIVE flag, | |
7479 | * which is set from the notifier callback for | |
7480 | * MODULE_STATE_LIVE. | |
7481 | */ | |
7482 | if ((btf_mod->flags & BTF_MODULE_F_LIVE) && try_module_get(btf_mod->module)) | |
541c3bad AN |
7483 | res = btf_mod->module; |
7484 | ||
7485 | break; | |
7486 | } | |
7487 | mutex_unlock(&btf_module_mutex); | |
7488 | #endif | |
7489 | ||
7490 | return res; | |
7491 | } | |
3d78417b | 7492 | |
9492450f KKD |
7493 | /* Returns struct btf corresponding to the struct module. |
7494 | * This function can return NULL or ERR_PTR. | |
dee872e1 KKD |
7495 | */ |
7496 | static struct btf *btf_get_module_btf(const struct module *module) | |
7497 | { | |
dee872e1 KKD |
7498 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
7499 | struct btf_module *btf_mod, *tmp; | |
7500 | #endif | |
9492450f KKD |
7501 | struct btf *btf = NULL; |
7502 | ||
7503 | if (!module) { | |
7504 | btf = bpf_get_btf_vmlinux(); | |
7ada3787 | 7505 | if (!IS_ERR_OR_NULL(btf)) |
9492450f KKD |
7506 | btf_get(btf); |
7507 | return btf; | |
7508 | } | |
dee872e1 | 7509 | |
dee872e1 KKD |
7510 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
7511 | mutex_lock(&btf_module_mutex); | |
7512 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
7513 | if (btf_mod->module != module) | |
7514 | continue; | |
7515 | ||
7516 | btf_get(btf_mod->btf); | |
7517 | btf = btf_mod->btf; | |
7518 | break; | |
7519 | } | |
7520 | mutex_unlock(&btf_module_mutex); | |
7521 | #endif | |
7522 | ||
7523 | return btf; | |
7524 | } | |
7525 | ||
3d78417b AS |
7526 | BPF_CALL_4(bpf_btf_find_by_name_kind, char *, name, int, name_sz, u32, kind, int, flags) |
7527 | { | |
edc3ec09 KKD |
7528 | struct btf *btf = NULL; |
7529 | int btf_obj_fd = 0; | |
3d78417b AS |
7530 | long ret; |
7531 | ||
7532 | if (flags) | |
7533 | return -EINVAL; | |
7534 | ||
7535 | if (name_sz <= 1 || name[name_sz - 1]) | |
7536 | return -EINVAL; | |
7537 | ||
edc3ec09 KKD |
7538 | ret = bpf_find_btf_id(name, kind, &btf); |
7539 | if (ret > 0 && btf_is_module(btf)) { | |
7540 | btf_obj_fd = __btf_new_fd(btf); | |
7541 | if (btf_obj_fd < 0) { | |
7542 | btf_put(btf); | |
7543 | return btf_obj_fd; | |
3d78417b | 7544 | } |
edc3ec09 | 7545 | return ret | (((u64)btf_obj_fd) << 32); |
3d78417b | 7546 | } |
edc3ec09 KKD |
7547 | if (ret > 0) |
7548 | btf_put(btf); | |
3d78417b AS |
7549 | return ret; |
7550 | } | |
7551 | ||
7552 | const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = { | |
7553 | .func = bpf_btf_find_by_name_kind, | |
7554 | .gpl_only = false, | |
7555 | .ret_type = RET_INTEGER, | |
216e3cd2 | 7556 | .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
3d78417b AS |
7557 | .arg2_type = ARG_CONST_SIZE, |
7558 | .arg3_type = ARG_ANYTHING, | |
7559 | .arg4_type = ARG_ANYTHING, | |
7560 | }; | |
eb529c5b | 7561 | |
d19ddb47 SL |
7562 | BTF_ID_LIST_GLOBAL(btf_tracing_ids, MAX_BTF_TRACING_TYPE) |
7563 | #define BTF_TRACING_TYPE(name, type) BTF_ID(struct, type) | |
7564 | BTF_TRACING_TYPE_xxx | |
7565 | #undef BTF_TRACING_TYPE | |
14f267d9 | 7566 | |
215bf496 AN |
7567 | static int btf_check_iter_kfuncs(struct btf *btf, const char *func_name, |
7568 | const struct btf_type *func, u32 func_flags) | |
7569 | { | |
7570 | u32 flags = func_flags & (KF_ITER_NEW | KF_ITER_NEXT | KF_ITER_DESTROY); | |
7571 | const char *name, *sfx, *iter_name; | |
7572 | const struct btf_param *arg; | |
7573 | const struct btf_type *t; | |
7574 | char exp_name[128]; | |
7575 | u32 nr_args; | |
7576 | ||
7577 | /* exactly one of KF_ITER_{NEW,NEXT,DESTROY} can be set */ | |
7578 | if (!flags || (flags & (flags - 1))) | |
7579 | return -EINVAL; | |
7580 | ||
7581 | /* any BPF iter kfunc should have `struct bpf_iter_<type> *` first arg */ | |
7582 | nr_args = btf_type_vlen(func); | |
7583 | if (nr_args < 1) | |
7584 | return -EINVAL; | |
7585 | ||
7586 | arg = &btf_params(func)[0]; | |
7587 | t = btf_type_skip_modifiers(btf, arg->type, NULL); | |
7588 | if (!t || !btf_type_is_ptr(t)) | |
7589 | return -EINVAL; | |
7590 | t = btf_type_skip_modifiers(btf, t->type, NULL); | |
7591 | if (!t || !__btf_type_is_struct(t)) | |
7592 | return -EINVAL; | |
7593 | ||
7594 | name = btf_name_by_offset(btf, t->name_off); | |
7595 | if (!name || strncmp(name, ITER_PREFIX, sizeof(ITER_PREFIX) - 1)) | |
7596 | return -EINVAL; | |
7597 | ||
7598 | /* sizeof(struct bpf_iter_<type>) should be a multiple of 8 to | |
7599 | * fit nicely in stack slots | |
7600 | */ | |
7601 | if (t->size == 0 || (t->size % 8)) | |
7602 | return -EINVAL; | |
7603 | ||
7604 | /* validate bpf_iter_<type>_{new,next,destroy}(struct bpf_iter_<type> *) | |
7605 | * naming pattern | |
7606 | */ | |
7607 | iter_name = name + sizeof(ITER_PREFIX) - 1; | |
7608 | if (flags & KF_ITER_NEW) | |
7609 | sfx = "new"; | |
7610 | else if (flags & KF_ITER_NEXT) | |
7611 | sfx = "next"; | |
7612 | else /* (flags & KF_ITER_DESTROY) */ | |
7613 | sfx = "destroy"; | |
7614 | ||
7615 | snprintf(exp_name, sizeof(exp_name), "bpf_iter_%s_%s", iter_name, sfx); | |
7616 | if (strcmp(func_name, exp_name)) | |
7617 | return -EINVAL; | |
7618 | ||
7619 | /* only iter constructor should have extra arguments */ | |
7620 | if (!(flags & KF_ITER_NEW) && nr_args != 1) | |
7621 | return -EINVAL; | |
7622 | ||
7623 | if (flags & KF_ITER_NEXT) { | |
7624 | /* bpf_iter_<type>_next() should return pointer */ | |
7625 | t = btf_type_skip_modifiers(btf, func->type, NULL); | |
7626 | if (!t || !btf_type_is_ptr(t)) | |
7627 | return -EINVAL; | |
7628 | } | |
7629 | ||
7630 | if (flags & KF_ITER_DESTROY) { | |
7631 | /* bpf_iter_<type>_destroy() should return void */ | |
7632 | t = btf_type_by_id(btf, func->type); | |
7633 | if (!t || !btf_type_is_void(t)) | |
7634 | return -EINVAL; | |
7635 | } | |
7636 | ||
7637 | return 0; | |
7638 | } | |
7639 | ||
7640 | static int btf_check_kfunc_protos(struct btf *btf, u32 func_id, u32 func_flags) | |
7641 | { | |
7642 | const struct btf_type *func; | |
7643 | const char *func_name; | |
7644 | int err; | |
7645 | ||
7646 | /* any kfunc should be FUNC -> FUNC_PROTO */ | |
7647 | func = btf_type_by_id(btf, func_id); | |
7648 | if (!func || !btf_type_is_func(func)) | |
7649 | return -EINVAL; | |
7650 | ||
7651 | /* sanity check kfunc name */ | |
7652 | func_name = btf_name_by_offset(btf, func->name_off); | |
7653 | if (!func_name || !func_name[0]) | |
7654 | return -EINVAL; | |
7655 | ||
7656 | func = btf_type_by_id(btf, func->type); | |
7657 | if (!func || !btf_type_is_func_proto(func)) | |
7658 | return -EINVAL; | |
7659 | ||
7660 | if (func_flags & (KF_ITER_NEW | KF_ITER_NEXT | KF_ITER_DESTROY)) { | |
7661 | err = btf_check_iter_kfuncs(btf, func_name, func, func_flags); | |
7662 | if (err) | |
7663 | return err; | |
7664 | } | |
7665 | ||
7666 | return 0; | |
7667 | } | |
7668 | ||
dee872e1 | 7669 | /* Kernel Function (kfunc) BTF ID set registration API */ |
14f267d9 | 7670 | |
a4703e31 KKD |
7671 | static int btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, |
7672 | struct btf_id_set8 *add_set) | |
14f267d9 | 7673 | { |
a4703e31 | 7674 | bool vmlinux_set = !btf_is_module(btf); |
dee872e1 | 7675 | struct btf_kfunc_set_tab *tab; |
a4703e31 | 7676 | struct btf_id_set8 *set; |
dee872e1 KKD |
7677 | u32 set_cnt; |
7678 | int ret; | |
7679 | ||
a4703e31 | 7680 | if (hook >= BTF_KFUNC_HOOK_MAX) { |
dee872e1 KKD |
7681 | ret = -EINVAL; |
7682 | goto end; | |
7683 | } | |
7684 | ||
7685 | if (!add_set->cnt) | |
7686 | return 0; | |
7687 | ||
7688 | tab = btf->kfunc_set_tab; | |
7689 | if (!tab) { | |
7690 | tab = kzalloc(sizeof(*tab), GFP_KERNEL | __GFP_NOWARN); | |
7691 | if (!tab) | |
7692 | return -ENOMEM; | |
7693 | btf->kfunc_set_tab = tab; | |
7694 | } | |
7695 | ||
a4703e31 | 7696 | set = tab->sets[hook]; |
dee872e1 KKD |
7697 | /* Warn when register_btf_kfunc_id_set is called twice for the same hook |
7698 | * for module sets. | |
7699 | */ | |
7700 | if (WARN_ON_ONCE(set && !vmlinux_set)) { | |
7701 | ret = -EINVAL; | |
7702 | goto end; | |
7703 | } | |
7704 | ||
7705 | /* We don't need to allocate, concatenate, and sort module sets, because | |
7706 | * only one is allowed per hook. Hence, we can directly assign the | |
7707 | * pointer and return. | |
7708 | */ | |
7709 | if (!vmlinux_set) { | |
a4703e31 | 7710 | tab->sets[hook] = add_set; |
dee872e1 KKD |
7711 | return 0; |
7712 | } | |
7713 | ||
7714 | /* In case of vmlinux sets, there may be more than one set being | |
7715 | * registered per hook. To create a unified set, we allocate a new set | |
7716 | * and concatenate all individual sets being registered. While each set | |
7717 | * is individually sorted, they may become unsorted when concatenated, | |
7718 | * hence re-sorting the final set again is required to make binary | |
a4703e31 | 7719 | * searching the set using btf_id_set8_contains function work. |
dee872e1 KKD |
7720 | */ |
7721 | set_cnt = set ? set->cnt : 0; | |
7722 | ||
7723 | if (set_cnt > U32_MAX - add_set->cnt) { | |
7724 | ret = -EOVERFLOW; | |
7725 | goto end; | |
7726 | } | |
7727 | ||
7728 | if (set_cnt + add_set->cnt > BTF_KFUNC_SET_MAX_CNT) { | |
7729 | ret = -E2BIG; | |
7730 | goto end; | |
7731 | } | |
7732 | ||
7733 | /* Grow set */ | |
a4703e31 KKD |
7734 | set = krealloc(tab->sets[hook], |
7735 | offsetof(struct btf_id_set8, pairs[set_cnt + add_set->cnt]), | |
dee872e1 KKD |
7736 | GFP_KERNEL | __GFP_NOWARN); |
7737 | if (!set) { | |
7738 | ret = -ENOMEM; | |
7739 | goto end; | |
7740 | } | |
7741 | ||
7742 | /* For newly allocated set, initialize set->cnt to 0 */ | |
a4703e31 | 7743 | if (!tab->sets[hook]) |
dee872e1 | 7744 | set->cnt = 0; |
a4703e31 | 7745 | tab->sets[hook] = set; |
dee872e1 KKD |
7746 | |
7747 | /* Concatenate the two sets */ | |
a4703e31 | 7748 | memcpy(set->pairs + set->cnt, add_set->pairs, add_set->cnt * sizeof(set->pairs[0])); |
dee872e1 KKD |
7749 | set->cnt += add_set->cnt; |
7750 | ||
a4703e31 | 7751 | sort(set->pairs, set->cnt, sizeof(set->pairs[0]), btf_id_cmp_func, NULL); |
dee872e1 KKD |
7752 | |
7753 | return 0; | |
7754 | end: | |
7755 | btf_free_kfunc_set_tab(btf); | |
7756 | return ret; | |
14f267d9 | 7757 | } |
14f267d9 | 7758 | |
a4703e31 | 7759 | static u32 *__btf_kfunc_id_set_contains(const struct btf *btf, |
dee872e1 | 7760 | enum btf_kfunc_hook hook, |
dee872e1 | 7761 | u32 kfunc_btf_id) |
14f267d9 | 7762 | { |
a4703e31 KKD |
7763 | struct btf_id_set8 *set; |
7764 | u32 *id; | |
14f267d9 | 7765 | |
a4703e31 KKD |
7766 | if (hook >= BTF_KFUNC_HOOK_MAX) |
7767 | return NULL; | |
dee872e1 | 7768 | if (!btf->kfunc_set_tab) |
a4703e31 KKD |
7769 | return NULL; |
7770 | set = btf->kfunc_set_tab->sets[hook]; | |
dee872e1 | 7771 | if (!set) |
a4703e31 KKD |
7772 | return NULL; |
7773 | id = btf_id_set8_contains(set, kfunc_btf_id); | |
7774 | if (!id) | |
7775 | return NULL; | |
7776 | /* The flags for BTF ID are located next to it */ | |
7777 | return id + 1; | |
dee872e1 KKD |
7778 | } |
7779 | ||
7780 | static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type) | |
7781 | { | |
7782 | switch (prog_type) { | |
cfe14564 YS |
7783 | case BPF_PROG_TYPE_UNSPEC: |
7784 | return BTF_KFUNC_HOOK_COMMON; | |
dee872e1 KKD |
7785 | case BPF_PROG_TYPE_XDP: |
7786 | return BTF_KFUNC_HOOK_XDP; | |
7787 | case BPF_PROG_TYPE_SCHED_CLS: | |
7788 | return BTF_KFUNC_HOOK_TC; | |
7789 | case BPF_PROG_TYPE_STRUCT_OPS: | |
7790 | return BTF_KFUNC_HOOK_STRUCT_OPS; | |
97949767 | 7791 | case BPF_PROG_TYPE_TRACING: |
d15bf150 | 7792 | case BPF_PROG_TYPE_LSM: |
97949767 BT |
7793 | return BTF_KFUNC_HOOK_TRACING; |
7794 | case BPF_PROG_TYPE_SYSCALL: | |
7795 | return BTF_KFUNC_HOOK_SYSCALL; | |
b5964b96 JK |
7796 | case BPF_PROG_TYPE_CGROUP_SKB: |
7797 | return BTF_KFUNC_HOOK_CGROUP_SKB; | |
7798 | case BPF_PROG_TYPE_SCHED_ACT: | |
7799 | return BTF_KFUNC_HOOK_SCHED_ACT; | |
7800 | case BPF_PROG_TYPE_SK_SKB: | |
7801 | return BTF_KFUNC_HOOK_SK_SKB; | |
7802 | case BPF_PROG_TYPE_SOCKET_FILTER: | |
7803 | return BTF_KFUNC_HOOK_SOCKET_FILTER; | |
7804 | case BPF_PROG_TYPE_LWT_OUT: | |
7805 | case BPF_PROG_TYPE_LWT_IN: | |
7806 | case BPF_PROG_TYPE_LWT_XMIT: | |
7807 | case BPF_PROG_TYPE_LWT_SEG6LOCAL: | |
7808 | return BTF_KFUNC_HOOK_LWT; | |
fd9c663b FW |
7809 | case BPF_PROG_TYPE_NETFILTER: |
7810 | return BTF_KFUNC_HOOK_NETFILTER; | |
dee872e1 KKD |
7811 | default: |
7812 | return BTF_KFUNC_HOOK_MAX; | |
14f267d9 | 7813 | } |
14f267d9 KKD |
7814 | } |
7815 | ||
dee872e1 KKD |
7816 | /* Caution: |
7817 | * Reference to the module (obtained using btf_try_get_module) corresponding to | |
7818 | * the struct btf *MUST* be held when calling this function from verifier | |
7819 | * context. This is usually true as we stash references in prog's kfunc_btf_tab; | |
7820 | * keeping the reference for the duration of the call provides the necessary | |
7821 | * protection for looking up a well-formed btf->kfunc_set_tab. | |
7822 | */ | |
a4703e31 | 7823 | u32 *btf_kfunc_id_set_contains(const struct btf *btf, |
dee872e1 | 7824 | enum bpf_prog_type prog_type, |
a4703e31 | 7825 | u32 kfunc_btf_id) |
dee872e1 KKD |
7826 | { |
7827 | enum btf_kfunc_hook hook; | |
cfe14564 YS |
7828 | u32 *kfunc_flags; |
7829 | ||
7830 | kfunc_flags = __btf_kfunc_id_set_contains(btf, BTF_KFUNC_HOOK_COMMON, kfunc_btf_id); | |
7831 | if (kfunc_flags) | |
7832 | return kfunc_flags; | |
0e32dfc8 | 7833 | |
dee872e1 | 7834 | hook = bpf_prog_type_to_kfunc_hook(prog_type); |
a4703e31 | 7835 | return __btf_kfunc_id_set_contains(btf, hook, kfunc_btf_id); |
dee872e1 | 7836 | } |
d9847eb8 | 7837 | |
5b481aca BT |
7838 | u32 *btf_kfunc_is_modify_return(const struct btf *btf, u32 kfunc_btf_id) |
7839 | { | |
7840 | return __btf_kfunc_id_set_contains(btf, BTF_KFUNC_HOOK_FMODRET, kfunc_btf_id); | |
7841 | } | |
7842 | ||
7843 | static int __register_btf_kfunc_id_set(enum btf_kfunc_hook hook, | |
7844 | const struct btf_kfunc_id_set *kset) | |
dee872e1 | 7845 | { |
dee872e1 | 7846 | struct btf *btf; |
215bf496 | 7847 | int ret, i; |
dee872e1 KKD |
7848 | |
7849 | btf = btf_get_module_btf(kset->owner); | |
c446fdac SF |
7850 | if (!btf) { |
7851 | if (!kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) { | |
7852 | pr_err("missing vmlinux BTF, cannot register kfuncs\n"); | |
7853 | return -ENOENT; | |
7854 | } | |
7855 | if (kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) { | |
7856 | pr_err("missing module BTF, cannot register kfuncs\n"); | |
7857 | return -ENOENT; | |
7858 | } | |
7859 | return 0; | |
7860 | } | |
7861 | if (IS_ERR(btf)) | |
7862 | return PTR_ERR(btf); | |
dee872e1 | 7863 | |
215bf496 AN |
7864 | for (i = 0; i < kset->set->cnt; i++) { |
7865 | ret = btf_check_kfunc_protos(btf, kset->set->pairs[i].id, | |
7866 | kset->set->pairs[i].flags); | |
7867 | if (ret) | |
7868 | goto err_out; | |
7869 | } | |
7870 | ||
a4703e31 | 7871 | ret = btf_populate_kfunc_set(btf, hook, kset->set); |
215bf496 | 7872 | err_out: |
9492450f | 7873 | btf_put(btf); |
dee872e1 KKD |
7874 | return ret; |
7875 | } | |
5b481aca BT |
7876 | |
7877 | /* This function must be invoked only from initcalls/module init functions */ | |
7878 | int register_btf_kfunc_id_set(enum bpf_prog_type prog_type, | |
7879 | const struct btf_kfunc_id_set *kset) | |
7880 | { | |
7881 | enum btf_kfunc_hook hook; | |
7882 | ||
7883 | hook = bpf_prog_type_to_kfunc_hook(prog_type); | |
7884 | return __register_btf_kfunc_id_set(hook, kset); | |
7885 | } | |
dee872e1 | 7886 | EXPORT_SYMBOL_GPL(register_btf_kfunc_id_set); |
be315829 | 7887 | |
5b481aca BT |
7888 | /* This function must be invoked only from initcalls/module init functions */ |
7889 | int register_btf_fmodret_id_set(const struct btf_kfunc_id_set *kset) | |
7890 | { | |
7891 | return __register_btf_kfunc_id_set(BTF_KFUNC_HOOK_FMODRET, kset); | |
7892 | } | |
7893 | EXPORT_SYMBOL_GPL(register_btf_fmodret_id_set); | |
7894 | ||
5ce937d6 KKD |
7895 | s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id) |
7896 | { | |
7897 | struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab; | |
7898 | struct btf_id_dtor_kfunc *dtor; | |
7899 | ||
7900 | if (!tab) | |
7901 | return -ENOENT; | |
7902 | /* Even though the size of tab->dtors[0] is > sizeof(u32), we only need | |
7903 | * to compare the first u32 with btf_id, so we can reuse btf_id_cmp_func. | |
7904 | */ | |
7905 | BUILD_BUG_ON(offsetof(struct btf_id_dtor_kfunc, btf_id) != 0); | |
7906 | dtor = bsearch(&btf_id, tab->dtors, tab->cnt, sizeof(tab->dtors[0]), btf_id_cmp_func); | |
7907 | if (!dtor) | |
7908 | return -ENOENT; | |
7909 | return dtor->kfunc_btf_id; | |
7910 | } | |
7911 | ||
14a324f6 KKD |
7912 | static int btf_check_dtor_kfuncs(struct btf *btf, const struct btf_id_dtor_kfunc *dtors, u32 cnt) |
7913 | { | |
7914 | const struct btf_type *dtor_func, *dtor_func_proto, *t; | |
7915 | const struct btf_param *args; | |
7916 | s32 dtor_btf_id; | |
7917 | u32 nr_args, i; | |
7918 | ||
7919 | for (i = 0; i < cnt; i++) { | |
7920 | dtor_btf_id = dtors[i].kfunc_btf_id; | |
7921 | ||
7922 | dtor_func = btf_type_by_id(btf, dtor_btf_id); | |
7923 | if (!dtor_func || !btf_type_is_func(dtor_func)) | |
7924 | return -EINVAL; | |
7925 | ||
7926 | dtor_func_proto = btf_type_by_id(btf, dtor_func->type); | |
7927 | if (!dtor_func_proto || !btf_type_is_func_proto(dtor_func_proto)) | |
7928 | return -EINVAL; | |
7929 | ||
7930 | /* Make sure the prototype of the destructor kfunc is 'void func(type *)' */ | |
7931 | t = btf_type_by_id(btf, dtor_func_proto->type); | |
7932 | if (!t || !btf_type_is_void(t)) | |
7933 | return -EINVAL; | |
7934 | ||
7935 | nr_args = btf_type_vlen(dtor_func_proto); | |
7936 | if (nr_args != 1) | |
7937 | return -EINVAL; | |
7938 | args = btf_params(dtor_func_proto); | |
7939 | t = btf_type_by_id(btf, args[0].type); | |
7940 | /* Allow any pointer type, as width on targets Linux supports | |
7941 | * will be same for all pointer types (i.e. sizeof(void *)) | |
7942 | */ | |
7943 | if (!t || !btf_type_is_ptr(t)) | |
7944 | return -EINVAL; | |
7945 | } | |
7946 | return 0; | |
7947 | } | |
7948 | ||
5ce937d6 KKD |
7949 | /* This function must be invoked only from initcalls/module init functions */ |
7950 | int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_cnt, | |
7951 | struct module *owner) | |
7952 | { | |
7953 | struct btf_id_dtor_kfunc_tab *tab; | |
7954 | struct btf *btf; | |
7955 | u32 tab_cnt; | |
7956 | int ret; | |
7957 | ||
7958 | btf = btf_get_module_btf(owner); | |
7959 | if (!btf) { | |
7960 | if (!owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) { | |
7961 | pr_err("missing vmlinux BTF, cannot register dtor kfuncs\n"); | |
7962 | return -ENOENT; | |
7963 | } | |
7964 | if (owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) { | |
7965 | pr_err("missing module BTF, cannot register dtor kfuncs\n"); | |
7966 | return -ENOENT; | |
7967 | } | |
7968 | return 0; | |
7969 | } | |
7970 | if (IS_ERR(btf)) | |
7971 | return PTR_ERR(btf); | |
7972 | ||
7973 | if (add_cnt >= BTF_DTOR_KFUNC_MAX_CNT) { | |
7974 | pr_err("cannot register more than %d kfunc destructors\n", BTF_DTOR_KFUNC_MAX_CNT); | |
7975 | ret = -E2BIG; | |
7976 | goto end; | |
7977 | } | |
7978 | ||
14a324f6 KKD |
7979 | /* Ensure that the prototype of dtor kfuncs being registered is sane */ |
7980 | ret = btf_check_dtor_kfuncs(btf, dtors, add_cnt); | |
7981 | if (ret < 0) | |
7982 | goto end; | |
7983 | ||
5ce937d6 KKD |
7984 | tab = btf->dtor_kfunc_tab; |
7985 | /* Only one call allowed for modules */ | |
7986 | if (WARN_ON_ONCE(tab && btf_is_module(btf))) { | |
7987 | ret = -EINVAL; | |
7988 | goto end; | |
7989 | } | |
7990 | ||
7991 | tab_cnt = tab ? tab->cnt : 0; | |
7992 | if (tab_cnt > U32_MAX - add_cnt) { | |
7993 | ret = -EOVERFLOW; | |
7994 | goto end; | |
7995 | } | |
7996 | if (tab_cnt + add_cnt >= BTF_DTOR_KFUNC_MAX_CNT) { | |
7997 | pr_err("cannot register more than %d kfunc destructors\n", BTF_DTOR_KFUNC_MAX_CNT); | |
7998 | ret = -E2BIG; | |
7999 | goto end; | |
8000 | } | |
8001 | ||
8002 | tab = krealloc(btf->dtor_kfunc_tab, | |
8003 | offsetof(struct btf_id_dtor_kfunc_tab, dtors[tab_cnt + add_cnt]), | |
8004 | GFP_KERNEL | __GFP_NOWARN); | |
8005 | if (!tab) { | |
8006 | ret = -ENOMEM; | |
8007 | goto end; | |
8008 | } | |
8009 | ||
8010 | if (!btf->dtor_kfunc_tab) | |
8011 | tab->cnt = 0; | |
8012 | btf->dtor_kfunc_tab = tab; | |
8013 | ||
8014 | memcpy(tab->dtors + tab->cnt, dtors, add_cnt * sizeof(tab->dtors[0])); | |
8015 | tab->cnt += add_cnt; | |
8016 | ||
8017 | sort(tab->dtors, tab->cnt, sizeof(tab->dtors[0]), btf_id_cmp_func, NULL); | |
8018 | ||
5ce937d6 | 8019 | end: |
74bc3a5a JO |
8020 | if (ret) |
8021 | btf_free_dtor_kfunc_tab(btf); | |
5ce937d6 KKD |
8022 | btf_put(btf); |
8023 | return ret; | |
8024 | } | |
8025 | EXPORT_SYMBOL_GPL(register_btf_id_dtor_kfuncs); | |
8026 | ||
e70e13e7 MC |
8027 | #define MAX_TYPES_ARE_COMPAT_DEPTH 2 |
8028 | ||
e70e13e7 MC |
8029 | /* Check local and target types for compatibility. This check is used for |
8030 | * type-based CO-RE relocations and follow slightly different rules than | |
8031 | * field-based relocations. This function assumes that root types were already | |
8032 | * checked for name match. Beyond that initial root-level name check, names | |
8033 | * are completely ignored. Compatibility rules are as follows: | |
6089fb32 | 8034 | * - any two STRUCTs/UNIONs/FWDs/ENUMs/INTs/ENUM64s are considered compatible, but |
e70e13e7 MC |
8035 | * kind should match for local and target types (i.e., STRUCT is not |
8036 | * compatible with UNION); | |
6089fb32 | 8037 | * - for ENUMs/ENUM64s, the size is ignored; |
e70e13e7 MC |
8038 | * - for INT, size and signedness are ignored; |
8039 | * - for ARRAY, dimensionality is ignored, element types are checked for | |
8040 | * compatibility recursively; | |
8041 | * - CONST/VOLATILE/RESTRICT modifiers are ignored; | |
8042 | * - TYPEDEFs/PTRs are compatible if types they pointing to are compatible; | |
8043 | * - FUNC_PROTOs are compatible if they have compatible signature: same | |
8044 | * number of input args and compatible return and argument types. | |
8045 | * These rules are not set in stone and probably will be adjusted as we get | |
8046 | * more experience with using BPF CO-RE relocations. | |
8047 | */ | |
29db4bea AS |
8048 | int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, |
8049 | const struct btf *targ_btf, __u32 targ_id) | |
8050 | { | |
fd75733d | 8051 | return __bpf_core_types_are_compat(local_btf, local_id, targ_btf, targ_id, |
e70e13e7 | 8052 | MAX_TYPES_ARE_COMPAT_DEPTH); |
29db4bea AS |
8053 | } |
8054 | ||
ec6209c8 DM |
8055 | #define MAX_TYPES_MATCH_DEPTH 2 |
8056 | ||
8057 | int bpf_core_types_match(const struct btf *local_btf, u32 local_id, | |
8058 | const struct btf *targ_btf, u32 targ_id) | |
8059 | { | |
8060 | return __bpf_core_types_match(local_btf, local_id, targ_btf, targ_id, false, | |
8061 | MAX_TYPES_MATCH_DEPTH); | |
8062 | } | |
8063 | ||
29db4bea AS |
8064 | static bool bpf_core_is_flavor_sep(const char *s) |
8065 | { | |
8066 | /* check X___Y name pattern, where X and Y are not underscores */ | |
8067 | return s[0] != '_' && /* X */ | |
8068 | s[1] == '_' && s[2] == '_' && s[3] == '_' && /* ___ */ | |
8069 | s[4] != '_'; /* Y */ | |
8070 | } | |
8071 | ||
8072 | size_t bpf_core_essential_name_len(const char *name) | |
8073 | { | |
8074 | size_t n = strlen(name); | |
8075 | int i; | |
8076 | ||
8077 | for (i = n - 5; i >= 0; i--) { | |
8078 | if (bpf_core_is_flavor_sep(name + i)) | |
8079 | return i + 1; | |
8080 | } | |
8081 | return n; | |
8082 | } | |
fbd94c7a | 8083 | |
1e89106d AS |
8084 | struct bpf_cand_cache { |
8085 | const char *name; | |
8086 | u32 name_len; | |
8087 | u16 kind; | |
8088 | u16 cnt; | |
8089 | struct { | |
8090 | const struct btf *btf; | |
8091 | u32 id; | |
8092 | } cands[]; | |
8093 | }; | |
8094 | ||
8095 | static void bpf_free_cands(struct bpf_cand_cache *cands) | |
8096 | { | |
8097 | if (!cands->cnt) | |
8098 | /* empty candidate array was allocated on stack */ | |
8099 | return; | |
8100 | kfree(cands); | |
8101 | } | |
8102 | ||
8103 | static void bpf_free_cands_from_cache(struct bpf_cand_cache *cands) | |
8104 | { | |
8105 | kfree(cands->name); | |
8106 | kfree(cands); | |
8107 | } | |
8108 | ||
8109 | #define VMLINUX_CAND_CACHE_SIZE 31 | |
8110 | static struct bpf_cand_cache *vmlinux_cand_cache[VMLINUX_CAND_CACHE_SIZE]; | |
8111 | ||
8112 | #define MODULE_CAND_CACHE_SIZE 31 | |
8113 | static struct bpf_cand_cache *module_cand_cache[MODULE_CAND_CACHE_SIZE]; | |
8114 | ||
8115 | static DEFINE_MUTEX(cand_cache_mutex); | |
8116 | ||
8117 | static void __print_cand_cache(struct bpf_verifier_log *log, | |
8118 | struct bpf_cand_cache **cache, | |
8119 | int cache_size) | |
8120 | { | |
8121 | struct bpf_cand_cache *cc; | |
8122 | int i, j; | |
8123 | ||
8124 | for (i = 0; i < cache_size; i++) { | |
8125 | cc = cache[i]; | |
8126 | if (!cc) | |
8127 | continue; | |
8128 | bpf_log(log, "[%d]%s(", i, cc->name); | |
8129 | for (j = 0; j < cc->cnt; j++) { | |
8130 | bpf_log(log, "%d", cc->cands[j].id); | |
8131 | if (j < cc->cnt - 1) | |
8132 | bpf_log(log, " "); | |
8133 | } | |
8134 | bpf_log(log, "), "); | |
8135 | } | |
8136 | } | |
8137 | ||
8138 | static void print_cand_cache(struct bpf_verifier_log *log) | |
8139 | { | |
8140 | mutex_lock(&cand_cache_mutex); | |
8141 | bpf_log(log, "vmlinux_cand_cache:"); | |
8142 | __print_cand_cache(log, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); | |
8143 | bpf_log(log, "\nmodule_cand_cache:"); | |
8144 | __print_cand_cache(log, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
8145 | bpf_log(log, "\n"); | |
8146 | mutex_unlock(&cand_cache_mutex); | |
8147 | } | |
8148 | ||
8149 | static u32 hash_cands(struct bpf_cand_cache *cands) | |
8150 | { | |
8151 | return jhash(cands->name, cands->name_len, 0); | |
8152 | } | |
8153 | ||
8154 | static struct bpf_cand_cache *check_cand_cache(struct bpf_cand_cache *cands, | |
8155 | struct bpf_cand_cache **cache, | |
8156 | int cache_size) | |
8157 | { | |
8158 | struct bpf_cand_cache *cc = cache[hash_cands(cands) % cache_size]; | |
8159 | ||
8160 | if (cc && cc->name_len == cands->name_len && | |
8161 | !strncmp(cc->name, cands->name, cands->name_len)) | |
8162 | return cc; | |
8163 | return NULL; | |
8164 | } | |
8165 | ||
8166 | static size_t sizeof_cands(int cnt) | |
8167 | { | |
8168 | return offsetof(struct bpf_cand_cache, cands[cnt]); | |
8169 | } | |
8170 | ||
8171 | static struct bpf_cand_cache *populate_cand_cache(struct bpf_cand_cache *cands, | |
8172 | struct bpf_cand_cache **cache, | |
8173 | int cache_size) | |
8174 | { | |
8175 | struct bpf_cand_cache **cc = &cache[hash_cands(cands) % cache_size], *new_cands; | |
8176 | ||
8177 | if (*cc) { | |
8178 | bpf_free_cands_from_cache(*cc); | |
8179 | *cc = NULL; | |
8180 | } | |
4674f210 | 8181 | new_cands = kmemdup(cands, sizeof_cands(cands->cnt), GFP_KERNEL); |
1e89106d AS |
8182 | if (!new_cands) { |
8183 | bpf_free_cands(cands); | |
8184 | return ERR_PTR(-ENOMEM); | |
8185 | } | |
1e89106d AS |
8186 | /* strdup the name, since it will stay in cache. |
8187 | * the cands->name points to strings in prog's BTF and the prog can be unloaded. | |
8188 | */ | |
8189 | new_cands->name = kmemdup_nul(cands->name, cands->name_len, GFP_KERNEL); | |
8190 | bpf_free_cands(cands); | |
8191 | if (!new_cands->name) { | |
8192 | kfree(new_cands); | |
8193 | return ERR_PTR(-ENOMEM); | |
8194 | } | |
8195 | *cc = new_cands; | |
8196 | return new_cands; | |
8197 | } | |
8198 | ||
29f2e5bd | 8199 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
1e89106d AS |
8200 | static void __purge_cand_cache(struct btf *btf, struct bpf_cand_cache **cache, |
8201 | int cache_size) | |
8202 | { | |
8203 | struct bpf_cand_cache *cc; | |
8204 | int i, j; | |
8205 | ||
8206 | for (i = 0; i < cache_size; i++) { | |
8207 | cc = cache[i]; | |
8208 | if (!cc) | |
8209 | continue; | |
8210 | if (!btf) { | |
8211 | /* when new module is loaded purge all of module_cand_cache, | |
8212 | * since new module might have candidates with the name | |
8213 | * that matches cached cands. | |
8214 | */ | |
8215 | bpf_free_cands_from_cache(cc); | |
8216 | cache[i] = NULL; | |
8217 | continue; | |
8218 | } | |
8219 | /* when module is unloaded purge cache entries | |
8220 | * that match module's btf | |
8221 | */ | |
8222 | for (j = 0; j < cc->cnt; j++) | |
8223 | if (cc->cands[j].btf == btf) { | |
8224 | bpf_free_cands_from_cache(cc); | |
8225 | cache[i] = NULL; | |
8226 | break; | |
8227 | } | |
8228 | } | |
8229 | ||
8230 | } | |
8231 | ||
8232 | static void purge_cand_cache(struct btf *btf) | |
8233 | { | |
8234 | mutex_lock(&cand_cache_mutex); | |
8235 | __purge_cand_cache(btf, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
8236 | mutex_unlock(&cand_cache_mutex); | |
8237 | } | |
29f2e5bd | 8238 | #endif |
1e89106d AS |
8239 | |
8240 | static struct bpf_cand_cache * | |
8241 | bpf_core_add_cands(struct bpf_cand_cache *cands, const struct btf *targ_btf, | |
8242 | int targ_start_id) | |
8243 | { | |
8244 | struct bpf_cand_cache *new_cands; | |
8245 | const struct btf_type *t; | |
8246 | const char *targ_name; | |
8247 | size_t targ_essent_len; | |
8248 | int n, i; | |
8249 | ||
8250 | n = btf_nr_types(targ_btf); | |
8251 | for (i = targ_start_id; i < n; i++) { | |
8252 | t = btf_type_by_id(targ_btf, i); | |
8253 | if (btf_kind(t) != cands->kind) | |
8254 | continue; | |
8255 | ||
8256 | targ_name = btf_name_by_offset(targ_btf, t->name_off); | |
8257 | if (!targ_name) | |
8258 | continue; | |
8259 | ||
8260 | /* the resched point is before strncmp to make sure that search | |
8261 | * for non-existing name will have a chance to schedule(). | |
8262 | */ | |
8263 | cond_resched(); | |
8264 | ||
8265 | if (strncmp(cands->name, targ_name, cands->name_len) != 0) | |
8266 | continue; | |
8267 | ||
8268 | targ_essent_len = bpf_core_essential_name_len(targ_name); | |
8269 | if (targ_essent_len != cands->name_len) | |
8270 | continue; | |
8271 | ||
8272 | /* most of the time there is only one candidate for a given kind+name pair */ | |
8273 | new_cands = kmalloc(sizeof_cands(cands->cnt + 1), GFP_KERNEL); | |
8274 | if (!new_cands) { | |
8275 | bpf_free_cands(cands); | |
8276 | return ERR_PTR(-ENOMEM); | |
8277 | } | |
8278 | ||
8279 | memcpy(new_cands, cands, sizeof_cands(cands->cnt)); | |
8280 | bpf_free_cands(cands); | |
8281 | cands = new_cands; | |
8282 | cands->cands[cands->cnt].btf = targ_btf; | |
8283 | cands->cands[cands->cnt].id = i; | |
8284 | cands->cnt++; | |
8285 | } | |
8286 | return cands; | |
8287 | } | |
8288 | ||
8289 | static struct bpf_cand_cache * | |
8290 | bpf_core_find_cands(struct bpf_core_ctx *ctx, u32 local_type_id) | |
8291 | { | |
8292 | struct bpf_cand_cache *cands, *cc, local_cand = {}; | |
8293 | const struct btf *local_btf = ctx->btf; | |
8294 | const struct btf_type *local_type; | |
8295 | const struct btf *main_btf; | |
8296 | size_t local_essent_len; | |
8297 | struct btf *mod_btf; | |
8298 | const char *name; | |
8299 | int id; | |
8300 | ||
8301 | main_btf = bpf_get_btf_vmlinux(); | |
8302 | if (IS_ERR(main_btf)) | |
f18a4997 | 8303 | return ERR_CAST(main_btf); |
7ada3787 KKD |
8304 | if (!main_btf) |
8305 | return ERR_PTR(-EINVAL); | |
1e89106d AS |
8306 | |
8307 | local_type = btf_type_by_id(local_btf, local_type_id); | |
8308 | if (!local_type) | |
8309 | return ERR_PTR(-EINVAL); | |
8310 | ||
8311 | name = btf_name_by_offset(local_btf, local_type->name_off); | |
8312 | if (str_is_empty(name)) | |
8313 | return ERR_PTR(-EINVAL); | |
8314 | local_essent_len = bpf_core_essential_name_len(name); | |
8315 | ||
8316 | cands = &local_cand; | |
8317 | cands->name = name; | |
8318 | cands->kind = btf_kind(local_type); | |
8319 | cands->name_len = local_essent_len; | |
8320 | ||
8321 | cc = check_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); | |
8322 | /* cands is a pointer to stack here */ | |
8323 | if (cc) { | |
8324 | if (cc->cnt) | |
8325 | return cc; | |
8326 | goto check_modules; | |
8327 | } | |
8328 | ||
8329 | /* Attempt to find target candidates in vmlinux BTF first */ | |
8330 | cands = bpf_core_add_cands(cands, main_btf, 1); | |
8331 | if (IS_ERR(cands)) | |
f18a4997 | 8332 | return ERR_CAST(cands); |
1e89106d AS |
8333 | |
8334 | /* cands is a pointer to kmalloced memory here if cands->cnt > 0 */ | |
8335 | ||
8336 | /* populate cache even when cands->cnt == 0 */ | |
8337 | cc = populate_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); | |
8338 | if (IS_ERR(cc)) | |
f18a4997 | 8339 | return ERR_CAST(cc); |
1e89106d AS |
8340 | |
8341 | /* if vmlinux BTF has any candidate, don't go for module BTFs */ | |
8342 | if (cc->cnt) | |
8343 | return cc; | |
8344 | ||
8345 | check_modules: | |
8346 | /* cands is a pointer to stack here and cands->cnt == 0 */ | |
8347 | cc = check_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
8348 | if (cc) | |
8349 | /* if cache has it return it even if cc->cnt == 0 */ | |
8350 | return cc; | |
8351 | ||
8352 | /* If candidate is not found in vmlinux's BTF then search in module's BTFs */ | |
8353 | spin_lock_bh(&btf_idr_lock); | |
8354 | idr_for_each_entry(&btf_idr, mod_btf, id) { | |
8355 | if (!btf_is_module(mod_btf)) | |
8356 | continue; | |
8357 | /* linear search could be slow hence unlock/lock | |
8358 | * the IDR to avoiding holding it for too long | |
8359 | */ | |
8360 | btf_get(mod_btf); | |
8361 | spin_unlock_bh(&btf_idr_lock); | |
8362 | cands = bpf_core_add_cands(cands, mod_btf, btf_nr_types(main_btf)); | |
acf1c3d6 AS |
8363 | btf_put(mod_btf); |
8364 | if (IS_ERR(cands)) | |
f18a4997 | 8365 | return ERR_CAST(cands); |
1e89106d | 8366 | spin_lock_bh(&btf_idr_lock); |
1e89106d AS |
8367 | } |
8368 | spin_unlock_bh(&btf_idr_lock); | |
8369 | /* cands is a pointer to kmalloced memory here if cands->cnt > 0 | |
8370 | * or pointer to stack if cands->cnd == 0. | |
8371 | * Copy it into the cache even when cands->cnt == 0 and | |
8372 | * return the result. | |
8373 | */ | |
8374 | return populate_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
8375 | } | |
8376 | ||
fbd94c7a AS |
8377 | int bpf_core_apply(struct bpf_core_ctx *ctx, const struct bpf_core_relo *relo, |
8378 | int relo_idx, void *insn) | |
8379 | { | |
1e89106d AS |
8380 | bool need_cands = relo->kind != BPF_CORE_TYPE_ID_LOCAL; |
8381 | struct bpf_core_cand_list cands = {}; | |
adb8fa19 | 8382 | struct bpf_core_relo_res targ_res; |
78c1f8d0 | 8383 | struct bpf_core_spec *specs; |
1e89106d AS |
8384 | int err; |
8385 | ||
78c1f8d0 AS |
8386 | /* ~4k of temp memory necessary to convert LLVM spec like "0:1:0:5" |
8387 | * into arrays of btf_ids of struct fields and array indices. | |
8388 | */ | |
8389 | specs = kcalloc(3, sizeof(*specs), GFP_KERNEL); | |
8390 | if (!specs) | |
8391 | return -ENOMEM; | |
8392 | ||
1e89106d AS |
8393 | if (need_cands) { |
8394 | struct bpf_cand_cache *cc; | |
8395 | int i; | |
8396 | ||
8397 | mutex_lock(&cand_cache_mutex); | |
8398 | cc = bpf_core_find_cands(ctx, relo->type_id); | |
8399 | if (IS_ERR(cc)) { | |
8400 | bpf_log(ctx->log, "target candidate search failed for %d\n", | |
8401 | relo->type_id); | |
8402 | err = PTR_ERR(cc); | |
8403 | goto out; | |
8404 | } | |
8405 | if (cc->cnt) { | |
8406 | cands.cands = kcalloc(cc->cnt, sizeof(*cands.cands), GFP_KERNEL); | |
8407 | if (!cands.cands) { | |
8408 | err = -ENOMEM; | |
8409 | goto out; | |
8410 | } | |
8411 | } | |
8412 | for (i = 0; i < cc->cnt; i++) { | |
8413 | bpf_log(ctx->log, | |
8414 | "CO-RE relocating %s %s: found target candidate [%d]\n", | |
8415 | btf_kind_str[cc->kind], cc->name, cc->cands[i].id); | |
8416 | cands.cands[i].btf = cc->cands[i].btf; | |
8417 | cands.cands[i].id = cc->cands[i].id; | |
8418 | } | |
8419 | cands.len = cc->cnt; | |
8420 | /* cand_cache_mutex needs to span the cache lookup and | |
8421 | * copy of btf pointer into bpf_core_cand_list, | |
adb8fa19 | 8422 | * since module can be unloaded while bpf_core_calc_relo_insn |
1e89106d AS |
8423 | * is working with module's btf. |
8424 | */ | |
8425 | } | |
8426 | ||
adb8fa19 MV |
8427 | err = bpf_core_calc_relo_insn((void *)ctx->log, relo, relo_idx, ctx->btf, &cands, specs, |
8428 | &targ_res); | |
8429 | if (err) | |
8430 | goto out; | |
8431 | ||
8432 | err = bpf_core_patch_insn((void *)ctx->log, insn, relo->insn_off / 8, relo, relo_idx, | |
8433 | &targ_res); | |
8434 | ||
1e89106d | 8435 | out: |
78c1f8d0 | 8436 | kfree(specs); |
1e89106d AS |
8437 | if (need_cands) { |
8438 | kfree(cands.cands); | |
8439 | mutex_unlock(&cand_cache_mutex); | |
8440 | if (ctx->log->level & BPF_LOG_LEVEL2) | |
8441 | print_cand_cache(ctx->log); | |
8442 | } | |
8443 | return err; | |
fbd94c7a | 8444 | } |
57539b1c DV |
8445 | |
8446 | bool btf_nested_type_is_trusted(struct bpf_verifier_log *log, | |
8447 | const struct bpf_reg_state *reg, | |
63260df1 | 8448 | const char *field_name, u32 btf_id, const char *suffix) |
57539b1c DV |
8449 | { |
8450 | struct btf *btf = reg->btf; | |
8451 | const struct btf_type *walk_type, *safe_type; | |
8452 | const char *tname; | |
8453 | char safe_tname[64]; | |
8454 | long ret, safe_id; | |
63260df1 | 8455 | const struct btf_member *member; |
57539b1c | 8456 | u32 i; |
57539b1c DV |
8457 | |
8458 | walk_type = btf_type_by_id(btf, reg->btf_id); | |
8459 | if (!walk_type) | |
8460 | return false; | |
8461 | ||
8462 | tname = btf_name_by_offset(btf, walk_type->name_off); | |
8463 | ||
6fcd486b | 8464 | ret = snprintf(safe_tname, sizeof(safe_tname), "%s%s", tname, suffix); |
57539b1c DV |
8465 | if (ret < 0) |
8466 | return false; | |
8467 | ||
8468 | safe_id = btf_find_by_name_kind(btf, safe_tname, BTF_INFO_KIND(walk_type->info)); | |
8469 | if (safe_id < 0) | |
8470 | return false; | |
8471 | ||
8472 | safe_type = btf_type_by_id(btf, safe_id); | |
8473 | if (!safe_type) | |
8474 | return false; | |
8475 | ||
57539b1c DV |
8476 | for_each_member(i, safe_type, member) { |
8477 | const char *m_name = __btf_name_by_offset(btf, member->name_off); | |
63260df1 AS |
8478 | const struct btf_type *mtype = btf_type_by_id(btf, member->type); |
8479 | u32 id; | |
8480 | ||
8481 | if (!btf_type_is_ptr(mtype)) | |
8482 | continue; | |
57539b1c | 8483 | |
63260df1 | 8484 | btf_type_skip_modifiers(btf, mtype->type, &id); |
57539b1c | 8485 | /* If we match on both type and name, the field is considered trusted. */ |
63260df1 | 8486 | if (btf_id == id && !strcmp(field_name, m_name)) |
57539b1c DV |
8487 | return true; |
8488 | } | |
8489 | ||
8490 | return false; | |
8491 | } | |
b613d335 DV |
8492 | |
8493 | bool btf_type_ids_nocast_alias(struct bpf_verifier_log *log, | |
8494 | const struct btf *reg_btf, u32 reg_id, | |
8495 | const struct btf *arg_btf, u32 arg_id) | |
8496 | { | |
8497 | const char *reg_name, *arg_name, *search_needle; | |
8498 | const struct btf_type *reg_type, *arg_type; | |
8499 | int reg_len, arg_len, cmp_len; | |
8500 | size_t pattern_len = sizeof(NOCAST_ALIAS_SUFFIX) - sizeof(char); | |
8501 | ||
8502 | reg_type = btf_type_by_id(reg_btf, reg_id); | |
8503 | if (!reg_type) | |
8504 | return false; | |
8505 | ||
8506 | arg_type = btf_type_by_id(arg_btf, arg_id); | |
8507 | if (!arg_type) | |
8508 | return false; | |
8509 | ||
8510 | reg_name = btf_name_by_offset(reg_btf, reg_type->name_off); | |
8511 | arg_name = btf_name_by_offset(arg_btf, arg_type->name_off); | |
8512 | ||
8513 | reg_len = strlen(reg_name); | |
8514 | arg_len = strlen(arg_name); | |
8515 | ||
8516 | /* Exactly one of the two type names may be suffixed with ___init, so | |
8517 | * if the strings are the same size, they can't possibly be no-cast | |
8518 | * aliases of one another. If you have two of the same type names, e.g. | |
8519 | * they're both nf_conn___init, it would be improper to return true | |
8520 | * because they are _not_ no-cast aliases, they are the same type. | |
8521 | */ | |
8522 | if (reg_len == arg_len) | |
8523 | return false; | |
8524 | ||
8525 | /* Either of the two names must be the other name, suffixed with ___init. */ | |
8526 | if ((reg_len != arg_len + pattern_len) && | |
8527 | (arg_len != reg_len + pattern_len)) | |
8528 | return false; | |
8529 | ||
8530 | if (reg_len < arg_len) { | |
8531 | search_needle = strstr(arg_name, NOCAST_ALIAS_SUFFIX); | |
8532 | cmp_len = reg_len; | |
8533 | } else { | |
8534 | search_needle = strstr(reg_name, NOCAST_ALIAS_SUFFIX); | |
8535 | cmp_len = arg_len; | |
8536 | } | |
8537 | ||
8538 | if (!search_needle) | |
8539 | return false; | |
8540 | ||
8541 | /* ___init suffix must come at the end of the name */ | |
8542 | if (*(search_needle + pattern_len) != '\0') | |
8543 | return false; | |
8544 | ||
8545 | return !strncmp(reg_name, arg_name, cmp_len); | |
8546 | } |