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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> | |
91cc1a99 | 28 | #include <net/sock.h> |
1e89106d | 29 | #include "../tools/lib/bpf/relo_core.h" |
69b693f0 MKL |
30 | |
31 | /* BTF (BPF Type Format) is the meta data format which describes | |
32 | * the data types of BPF program/map. Hence, it basically focus | |
33 | * on the C programming language which the modern BPF is primary | |
34 | * using. | |
35 | * | |
36 | * ELF Section: | |
37 | * ~~~~~~~~~~~ | |
38 | * The BTF data is stored under the ".BTF" ELF section | |
39 | * | |
40 | * struct btf_type: | |
41 | * ~~~~~~~~~~~~~~~ | |
42 | * Each 'struct btf_type' object describes a C data type. | |
43 | * Depending on the type it is describing, a 'struct btf_type' | |
44 | * object may be followed by more data. F.e. | |
45 | * To describe an array, 'struct btf_type' is followed by | |
46 | * 'struct btf_array'. | |
47 | * | |
48 | * 'struct btf_type' and any extra data following it are | |
49 | * 4 bytes aligned. | |
50 | * | |
51 | * Type section: | |
52 | * ~~~~~~~~~~~~~ | |
53 | * The BTF type section contains a list of 'struct btf_type' objects. | |
54 | * Each one describes a C type. Recall from the above section | |
55 | * that a 'struct btf_type' object could be immediately followed by extra | |
8fb33b60 | 56 | * data in order to describe some particular C types. |
69b693f0 MKL |
57 | * |
58 | * type_id: | |
59 | * ~~~~~~~ | |
60 | * Each btf_type object is identified by a type_id. The type_id | |
61 | * is implicitly implied by the location of the btf_type object in | |
62 | * the BTF type section. The first one has type_id 1. The second | |
63 | * one has type_id 2...etc. Hence, an earlier btf_type has | |
64 | * a smaller type_id. | |
65 | * | |
66 | * A btf_type object may refer to another btf_type object by using | |
67 | * type_id (i.e. the "type" in the "struct btf_type"). | |
68 | * | |
69 | * NOTE that we cannot assume any reference-order. | |
70 | * A btf_type object can refer to an earlier btf_type object | |
71 | * but it can also refer to a later btf_type object. | |
72 | * | |
73 | * For example, to describe "const void *". A btf_type | |
74 | * object describing "const" may refer to another btf_type | |
75 | * object describing "void *". This type-reference is done | |
76 | * by specifying type_id: | |
77 | * | |
78 | * [1] CONST (anon) type_id=2 | |
79 | * [2] PTR (anon) type_id=0 | |
80 | * | |
81 | * The above is the btf_verifier debug log: | |
82 | * - Each line started with "[?]" is a btf_type object | |
83 | * - [?] is the type_id of the btf_type object. | |
84 | * - CONST/PTR is the BTF_KIND_XXX | |
85 | * - "(anon)" is the name of the type. It just | |
86 | * happens that CONST and PTR has no name. | |
87 | * - type_id=XXX is the 'u32 type' in btf_type | |
88 | * | |
89 | * NOTE: "void" has type_id 0 | |
90 | * | |
91 | * String section: | |
92 | * ~~~~~~~~~~~~~~ | |
93 | * The BTF string section contains the names used by the type section. | |
94 | * Each string is referred by an "offset" from the beginning of the | |
95 | * string section. | |
96 | * | |
97 | * Each string is '\0' terminated. | |
98 | * | |
99 | * The first character in the string section must be '\0' | |
100 | * which is used to mean 'anonymous'. Some btf_type may not | |
101 | * have a name. | |
102 | */ | |
103 | ||
104 | /* BTF verification: | |
105 | * | |
106 | * To verify BTF data, two passes are needed. | |
107 | * | |
108 | * Pass #1 | |
109 | * ~~~~~~~ | |
110 | * The first pass is to collect all btf_type objects to | |
111 | * an array: "btf->types". | |
112 | * | |
113 | * Depending on the C type that a btf_type is describing, | |
114 | * a btf_type may be followed by extra data. We don't know | |
115 | * how many btf_type is there, and more importantly we don't | |
116 | * know where each btf_type is located in the type section. | |
117 | * | |
118 | * Without knowing the location of each type_id, most verifications | |
119 | * cannot be done. e.g. an earlier btf_type may refer to a later | |
120 | * btf_type (recall the "const void *" above), so we cannot | |
121 | * check this type-reference in the first pass. | |
122 | * | |
123 | * In the first pass, it still does some verifications (e.g. | |
124 | * checking the name is a valid offset to the string section). | |
eb3f595d MKL |
125 | * |
126 | * Pass #2 | |
127 | * ~~~~~~~ | |
128 | * The main focus is to resolve a btf_type that is referring | |
129 | * to another type. | |
130 | * | |
131 | * We have to ensure the referring type: | |
132 | * 1) does exist in the BTF (i.e. in btf->types[]) | |
133 | * 2) does not cause a loop: | |
134 | * struct A { | |
135 | * struct B b; | |
136 | * }; | |
137 | * | |
138 | * struct B { | |
139 | * struct A a; | |
140 | * }; | |
141 | * | |
142 | * btf_type_needs_resolve() decides if a btf_type needs | |
143 | * to be resolved. | |
144 | * | |
145 | * The needs_resolve type implements the "resolve()" ops which | |
146 | * essentially does a DFS and detects backedge. | |
147 | * | |
148 | * During resolve (or DFS), different C types have different | |
149 | * "RESOLVED" conditions. | |
150 | * | |
151 | * When resolving a BTF_KIND_STRUCT, we need to resolve all its | |
152 | * members because a member is always referring to another | |
153 | * type. A struct's member can be treated as "RESOLVED" if | |
154 | * it is referring to a BTF_KIND_PTR. Otherwise, the | |
155 | * following valid C struct would be rejected: | |
156 | * | |
157 | * struct A { | |
158 | * int m; | |
159 | * struct A *a; | |
160 | * }; | |
161 | * | |
162 | * When resolving a BTF_KIND_PTR, it needs to keep resolving if | |
163 | * it is referring to another BTF_KIND_PTR. Otherwise, we cannot | |
164 | * detect a pointer loop, e.g.: | |
165 | * BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR + | |
166 | * ^ | | |
167 | * +-----------------------------------------+ | |
168 | * | |
69b693f0 MKL |
169 | */ |
170 | ||
b1e8818c | 171 | #define BITS_PER_U128 (sizeof(u64) * BITS_PER_BYTE * 2) |
69b693f0 MKL |
172 | #define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1) |
173 | #define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK) | |
174 | #define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3) | |
175 | #define BITS_ROUNDUP_BYTES(bits) \ | |
176 | (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits)) | |
177 | ||
b1828f0b | 178 | #define BTF_INFO_MASK 0x9f00ffff |
aea2f7b8 MKL |
179 | #define BTF_INT_MASK 0x0fffffff |
180 | #define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE) | |
181 | #define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET) | |
182 | ||
69b693f0 MKL |
183 | /* 16MB for 64k structs and each has 16 members and |
184 | * a few MB spaces for the string section. | |
185 | * The hard limit is S32_MAX. | |
186 | */ | |
187 | #define BTF_MAX_SIZE (16 * 1024 * 1024) | |
69b693f0 | 188 | |
eb3f595d MKL |
189 | #define for_each_member_from(i, from, struct_type, member) \ |
190 | for (i = from, member = btf_type_member(struct_type) + from; \ | |
191 | i < btf_type_vlen(struct_type); \ | |
192 | i++, member++) | |
193 | ||
1dc92851 DB |
194 | #define for_each_vsi_from(i, from, struct_type, member) \ |
195 | for (i = from, member = btf_type_var_secinfo(struct_type) + from; \ | |
196 | i < btf_type_vlen(struct_type); \ | |
197 | i++, member++) | |
198 | ||
1b9ed84e QM |
199 | DEFINE_IDR(btf_idr); |
200 | DEFINE_SPINLOCK(btf_idr_lock); | |
78958fca | 201 | |
dee872e1 | 202 | enum btf_kfunc_hook { |
cfe14564 | 203 | BTF_KFUNC_HOOK_COMMON, |
dee872e1 KKD |
204 | BTF_KFUNC_HOOK_XDP, |
205 | BTF_KFUNC_HOOK_TC, | |
206 | BTF_KFUNC_HOOK_STRUCT_OPS, | |
97949767 BT |
207 | BTF_KFUNC_HOOK_TRACING, |
208 | BTF_KFUNC_HOOK_SYSCALL, | |
5b481aca | 209 | BTF_KFUNC_HOOK_FMODRET, |
dee872e1 KKD |
210 | BTF_KFUNC_HOOK_MAX, |
211 | }; | |
212 | ||
213 | enum { | |
f9b34818 | 214 | BTF_KFUNC_SET_MAX_CNT = 256, |
5ce937d6 | 215 | BTF_DTOR_KFUNC_MAX_CNT = 256, |
dee872e1 KKD |
216 | }; |
217 | ||
218 | struct btf_kfunc_set_tab { | |
a4703e31 | 219 | struct btf_id_set8 *sets[BTF_KFUNC_HOOK_MAX]; |
dee872e1 KKD |
220 | }; |
221 | ||
5ce937d6 KKD |
222 | struct btf_id_dtor_kfunc_tab { |
223 | u32 cnt; | |
224 | struct btf_id_dtor_kfunc dtors[]; | |
225 | }; | |
226 | ||
69b693f0 | 227 | struct btf { |
f80442a4 | 228 | void *data; |
69b693f0 | 229 | struct btf_type **types; |
eb3f595d MKL |
230 | u32 *resolved_ids; |
231 | u32 *resolved_sizes; | |
69b693f0 MKL |
232 | const char *strings; |
233 | void *nohdr_data; | |
f80442a4 | 234 | struct btf_header hdr; |
951bb646 | 235 | u32 nr_types; /* includes VOID for base BTF */ |
69b693f0 MKL |
236 | u32 types_size; |
237 | u32 data_size; | |
f56a653c | 238 | refcount_t refcnt; |
78958fca MKL |
239 | u32 id; |
240 | struct rcu_head rcu; | |
dee872e1 | 241 | struct btf_kfunc_set_tab *kfunc_set_tab; |
5ce937d6 | 242 | struct btf_id_dtor_kfunc_tab *dtor_kfunc_tab; |
8ffa5cc1 | 243 | struct btf_struct_metas *struct_meta_tab; |
951bb646 AN |
244 | |
245 | /* split BTF support */ | |
246 | struct btf *base_btf; | |
247 | u32 start_id; /* first type ID in this BTF (0 for base BTF) */ | |
248 | u32 start_str_off; /* first string offset (0 for base BTF) */ | |
53297220 AN |
249 | char name[MODULE_NAME_LEN]; |
250 | bool kernel_btf; | |
69b693f0 MKL |
251 | }; |
252 | ||
eb3f595d MKL |
253 | enum verifier_phase { |
254 | CHECK_META, | |
255 | CHECK_TYPE, | |
256 | }; | |
257 | ||
258 | struct resolve_vertex { | |
259 | const struct btf_type *t; | |
260 | u32 type_id; | |
261 | u16 next_member; | |
262 | }; | |
263 | ||
264 | enum visit_state { | |
265 | NOT_VISITED, | |
266 | VISITED, | |
267 | RESOLVED, | |
268 | }; | |
269 | ||
270 | enum resolve_mode { | |
271 | RESOLVE_TBD, /* To Be Determined */ | |
272 | RESOLVE_PTR, /* Resolving for Pointer */ | |
273 | RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union | |
274 | * or array | |
275 | */ | |
276 | }; | |
277 | ||
278 | #define MAX_RESOLVE_DEPTH 32 | |
279 | ||
f80442a4 MKL |
280 | struct btf_sec_info { |
281 | u32 off; | |
282 | u32 len; | |
283 | }; | |
284 | ||
69b693f0 MKL |
285 | struct btf_verifier_env { |
286 | struct btf *btf; | |
eb3f595d MKL |
287 | u8 *visit_states; |
288 | struct resolve_vertex stack[MAX_RESOLVE_DEPTH]; | |
69b693f0 MKL |
289 | struct bpf_verifier_log log; |
290 | u32 log_type_id; | |
eb3f595d MKL |
291 | u32 top_stack; |
292 | enum verifier_phase phase; | |
293 | enum resolve_mode resolve_mode; | |
69b693f0 MKL |
294 | }; |
295 | ||
296 | static const char * const btf_kind_str[NR_BTF_KINDS] = { | |
297 | [BTF_KIND_UNKN] = "UNKNOWN", | |
298 | [BTF_KIND_INT] = "INT", | |
299 | [BTF_KIND_PTR] = "PTR", | |
300 | [BTF_KIND_ARRAY] = "ARRAY", | |
301 | [BTF_KIND_STRUCT] = "STRUCT", | |
302 | [BTF_KIND_UNION] = "UNION", | |
303 | [BTF_KIND_ENUM] = "ENUM", | |
304 | [BTF_KIND_FWD] = "FWD", | |
305 | [BTF_KIND_TYPEDEF] = "TYPEDEF", | |
306 | [BTF_KIND_VOLATILE] = "VOLATILE", | |
307 | [BTF_KIND_CONST] = "CONST", | |
308 | [BTF_KIND_RESTRICT] = "RESTRICT", | |
2667a262 MKL |
309 | [BTF_KIND_FUNC] = "FUNC", |
310 | [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO", | |
1dc92851 DB |
311 | [BTF_KIND_VAR] = "VAR", |
312 | [BTF_KIND_DATASEC] = "DATASEC", | |
b1828f0b | 313 | [BTF_KIND_FLOAT] = "FLOAT", |
223f903e | 314 | [BTF_KIND_DECL_TAG] = "DECL_TAG", |
8c42d2fa | 315 | [BTF_KIND_TYPE_TAG] = "TYPE_TAG", |
6089fb32 | 316 | [BTF_KIND_ENUM64] = "ENUM64", |
69b693f0 MKL |
317 | }; |
318 | ||
e6ac2450 | 319 | const char *btf_type_str(const struct btf_type *t) |
be8704ff AS |
320 | { |
321 | return btf_kind_str[BTF_INFO_KIND(t->info)]; | |
322 | } | |
323 | ||
31d0bc81 AM |
324 | /* Chunk size we use in safe copy of data to be shown. */ |
325 | #define BTF_SHOW_OBJ_SAFE_SIZE 32 | |
326 | ||
327 | /* | |
328 | * This is the maximum size of a base type value (equivalent to a | |
329 | * 128-bit int); if we are at the end of our safe buffer and have | |
330 | * less than 16 bytes space we can't be assured of being able | |
331 | * to copy the next type safely, so in such cases we will initiate | |
332 | * a new copy. | |
333 | */ | |
334 | #define BTF_SHOW_OBJ_BASE_TYPE_SIZE 16 | |
335 | ||
336 | /* Type name size */ | |
337 | #define BTF_SHOW_NAME_SIZE 80 | |
338 | ||
339 | /* | |
340 | * Common data to all BTF show operations. Private show functions can add | |
341 | * their own data to a structure containing a struct btf_show and consult it | |
342 | * in the show callback. See btf_type_show() below. | |
343 | * | |
344 | * One challenge with showing nested data is we want to skip 0-valued | |
345 | * data, but in order to figure out whether a nested object is all zeros | |
346 | * we need to walk through it. As a result, we need to make two passes | |
347 | * when handling structs, unions and arrays; the first path simply looks | |
348 | * for nonzero data, while the second actually does the display. The first | |
349 | * pass is signalled by show->state.depth_check being set, and if we | |
350 | * encounter a non-zero value we set show->state.depth_to_show to | |
351 | * the depth at which we encountered it. When we have completed the | |
352 | * first pass, we will know if anything needs to be displayed if | |
353 | * depth_to_show > depth. See btf_[struct,array]_show() for the | |
354 | * implementation of this. | |
355 | * | |
356 | * Another problem is we want to ensure the data for display is safe to | |
357 | * access. To support this, the anonymous "struct {} obj" tracks the data | |
358 | * object and our safe copy of it. We copy portions of the data needed | |
359 | * to the object "copy" buffer, but because its size is limited to | |
360 | * BTF_SHOW_OBJ_COPY_LEN bytes, multiple copies may be required as we | |
361 | * traverse larger objects for display. | |
362 | * | |
363 | * The various data type show functions all start with a call to | |
364 | * btf_show_start_type() which returns a pointer to the safe copy | |
365 | * of the data needed (or if BTF_SHOW_UNSAFE is specified, to the | |
366 | * raw data itself). btf_show_obj_safe() is responsible for | |
367 | * using copy_from_kernel_nofault() to update the safe data if necessary | |
368 | * as we traverse the object's data. skbuff-like semantics are | |
369 | * used: | |
370 | * | |
371 | * - obj.head points to the start of the toplevel object for display | |
372 | * - obj.size is the size of the toplevel object | |
373 | * - obj.data points to the current point in the original data at | |
374 | * which our safe data starts. obj.data will advance as we copy | |
375 | * portions of the data. | |
376 | * | |
377 | * In most cases a single copy will suffice, but larger data structures | |
378 | * such as "struct task_struct" will require many copies. The logic in | |
379 | * btf_show_obj_safe() handles the logic that determines if a new | |
380 | * copy_from_kernel_nofault() is needed. | |
381 | */ | |
382 | struct btf_show { | |
383 | u64 flags; | |
384 | void *target; /* target of show operation (seq file, buffer) */ | |
385 | void (*showfn)(struct btf_show *show, const char *fmt, va_list args); | |
386 | const struct btf *btf; | |
387 | /* below are used during iteration */ | |
388 | struct { | |
389 | u8 depth; | |
390 | u8 depth_to_show; | |
391 | u8 depth_check; | |
392 | u8 array_member:1, | |
393 | array_terminated:1; | |
394 | u16 array_encoding; | |
395 | u32 type_id; | |
396 | int status; /* non-zero for error */ | |
397 | const struct btf_type *type; | |
398 | const struct btf_member *member; | |
399 | char name[BTF_SHOW_NAME_SIZE]; /* space for member name/type */ | |
400 | } state; | |
401 | struct { | |
402 | u32 size; | |
403 | void *head; | |
404 | void *data; | |
405 | u8 safe[BTF_SHOW_OBJ_SAFE_SIZE]; | |
406 | } obj; | |
407 | }; | |
408 | ||
69b693f0 MKL |
409 | struct btf_kind_operations { |
410 | s32 (*check_meta)(struct btf_verifier_env *env, | |
411 | const struct btf_type *t, | |
412 | u32 meta_left); | |
eb3f595d MKL |
413 | int (*resolve)(struct btf_verifier_env *env, |
414 | const struct resolve_vertex *v); | |
179cde8c MKL |
415 | int (*check_member)(struct btf_verifier_env *env, |
416 | const struct btf_type *struct_type, | |
417 | const struct btf_member *member, | |
418 | const struct btf_type *member_type); | |
9d5f9f70 YS |
419 | int (*check_kflag_member)(struct btf_verifier_env *env, |
420 | const struct btf_type *struct_type, | |
421 | const struct btf_member *member, | |
422 | const struct btf_type *member_type); | |
69b693f0 MKL |
423 | void (*log_details)(struct btf_verifier_env *env, |
424 | const struct btf_type *t); | |
31d0bc81 | 425 | void (*show)(const struct btf *btf, const struct btf_type *t, |
b00b8dae | 426 | u32 type_id, void *data, u8 bits_offsets, |
31d0bc81 | 427 | struct btf_show *show); |
69b693f0 MKL |
428 | }; |
429 | ||
430 | static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS]; | |
431 | static struct btf_type btf_void; | |
432 | ||
2667a262 MKL |
433 | static int btf_resolve(struct btf_verifier_env *env, |
434 | const struct btf_type *t, u32 type_id); | |
435 | ||
d7e7b42f YS |
436 | static int btf_func_check(struct btf_verifier_env *env, |
437 | const struct btf_type *t); | |
438 | ||
eb3f595d MKL |
439 | static bool btf_type_is_modifier(const struct btf_type *t) |
440 | { | |
441 | /* Some of them is not strictly a C modifier | |
442 | * but they are grouped into the same bucket | |
443 | * for BTF concern: | |
444 | * A type (t) that refers to another | |
445 | * type through t->type AND its size cannot | |
446 | * be determined without following the t->type. | |
447 | * | |
448 | * ptr does not fall into this bucket | |
449 | * because its size is always sizeof(void *). | |
450 | */ | |
451 | switch (BTF_INFO_KIND(t->info)) { | |
452 | case BTF_KIND_TYPEDEF: | |
453 | case BTF_KIND_VOLATILE: | |
454 | case BTF_KIND_CONST: | |
455 | case BTF_KIND_RESTRICT: | |
8c42d2fa | 456 | case BTF_KIND_TYPE_TAG: |
eb3f595d MKL |
457 | return true; |
458 | } | |
459 | ||
460 | return false; | |
461 | } | |
462 | ||
2824ecb7 | 463 | bool btf_type_is_void(const struct btf_type *t) |
eb3f595d | 464 | { |
b47a0bd2 MKL |
465 | return t == &btf_void; |
466 | } | |
467 | ||
468 | static bool btf_type_is_fwd(const struct btf_type *t) | |
469 | { | |
470 | return BTF_INFO_KIND(t->info) == BTF_KIND_FWD; | |
471 | } | |
472 | ||
473 | static bool btf_type_nosize(const struct btf_type *t) | |
474 | { | |
2667a262 MKL |
475 | return btf_type_is_void(t) || btf_type_is_fwd(t) || |
476 | btf_type_is_func(t) || btf_type_is_func_proto(t); | |
eb3f595d MKL |
477 | } |
478 | ||
b47a0bd2 | 479 | static bool btf_type_nosize_or_null(const struct btf_type *t) |
eb3f595d | 480 | { |
b47a0bd2 | 481 | return !t || btf_type_nosize(t); |
eb3f595d MKL |
482 | } |
483 | ||
1dc92851 DB |
484 | static bool btf_type_is_datasec(const struct btf_type *t) |
485 | { | |
486 | return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC; | |
487 | } | |
488 | ||
223f903e | 489 | static bool btf_type_is_decl_tag(const struct btf_type *t) |
b5ea834d | 490 | { |
223f903e | 491 | return BTF_INFO_KIND(t->info) == BTF_KIND_DECL_TAG; |
b5ea834d YS |
492 | } |
493 | ||
223f903e | 494 | static bool btf_type_is_decl_tag_target(const struct btf_type *t) |
b5ea834d YS |
495 | { |
496 | return btf_type_is_func(t) || btf_type_is_struct(t) || | |
bd16dee6 | 497 | btf_type_is_var(t) || btf_type_is_typedef(t); |
b5ea834d YS |
498 | } |
499 | ||
541c3bad | 500 | u32 btf_nr_types(const struct btf *btf) |
951bb646 AN |
501 | { |
502 | u32 total = 0; | |
503 | ||
504 | while (btf) { | |
505 | total += btf->nr_types; | |
506 | btf = btf->base_btf; | |
507 | } | |
508 | ||
509 | return total; | |
510 | } | |
511 | ||
27ae7997 MKL |
512 | s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind) |
513 | { | |
514 | const struct btf_type *t; | |
515 | const char *tname; | |
951bb646 | 516 | u32 i, total; |
27ae7997 | 517 | |
541c3bad | 518 | total = btf_nr_types(btf); |
951bb646 AN |
519 | for (i = 1; i < total; i++) { |
520 | t = btf_type_by_id(btf, i); | |
27ae7997 MKL |
521 | if (BTF_INFO_KIND(t->info) != kind) |
522 | continue; | |
523 | ||
524 | tname = btf_name_by_offset(btf, t->name_off); | |
525 | if (!strcmp(tname, name)) | |
526 | return i; | |
527 | } | |
528 | ||
529 | return -ENOENT; | |
530 | } | |
531 | ||
edc3ec09 KKD |
532 | static s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p) |
533 | { | |
534 | struct btf *btf; | |
535 | s32 ret; | |
536 | int id; | |
537 | ||
538 | btf = bpf_get_btf_vmlinux(); | |
539 | if (IS_ERR(btf)) | |
540 | return PTR_ERR(btf); | |
7ada3787 KKD |
541 | if (!btf) |
542 | return -EINVAL; | |
edc3ec09 KKD |
543 | |
544 | ret = btf_find_by_name_kind(btf, name, kind); | |
545 | /* ret is never zero, since btf_find_by_name_kind returns | |
546 | * positive btf_id or negative error. | |
547 | */ | |
548 | if (ret > 0) { | |
549 | btf_get(btf); | |
550 | *btf_p = btf; | |
551 | return ret; | |
552 | } | |
553 | ||
554 | /* If name is not found in vmlinux's BTF then search in module's BTFs */ | |
555 | spin_lock_bh(&btf_idr_lock); | |
556 | idr_for_each_entry(&btf_idr, btf, id) { | |
557 | if (!btf_is_module(btf)) | |
558 | continue; | |
559 | /* linear search could be slow hence unlock/lock | |
560 | * the IDR to avoiding holding it for too long | |
561 | */ | |
562 | btf_get(btf); | |
563 | spin_unlock_bh(&btf_idr_lock); | |
564 | ret = btf_find_by_name_kind(btf, name, kind); | |
565 | if (ret > 0) { | |
566 | *btf_p = btf; | |
567 | return ret; | |
568 | } | |
569 | spin_lock_bh(&btf_idr_lock); | |
570 | btf_put(btf); | |
571 | } | |
572 | spin_unlock_bh(&btf_idr_lock); | |
573 | return ret; | |
574 | } | |
575 | ||
27ae7997 MKL |
576 | const struct btf_type *btf_type_skip_modifiers(const struct btf *btf, |
577 | u32 id, u32 *res_id) | |
578 | { | |
579 | const struct btf_type *t = btf_type_by_id(btf, id); | |
580 | ||
581 | while (btf_type_is_modifier(t)) { | |
582 | id = t->type; | |
583 | t = btf_type_by_id(btf, t->type); | |
584 | } | |
585 | ||
586 | if (res_id) | |
587 | *res_id = id; | |
588 | ||
589 | return t; | |
590 | } | |
591 | ||
592 | const struct btf_type *btf_type_resolve_ptr(const struct btf *btf, | |
593 | u32 id, u32 *res_id) | |
594 | { | |
595 | const struct btf_type *t; | |
596 | ||
597 | t = btf_type_skip_modifiers(btf, id, NULL); | |
598 | if (!btf_type_is_ptr(t)) | |
599 | return NULL; | |
600 | ||
601 | return btf_type_skip_modifiers(btf, t->type, res_id); | |
602 | } | |
603 | ||
604 | const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf, | |
605 | u32 id, u32 *res_id) | |
606 | { | |
607 | const struct btf_type *ptype; | |
608 | ||
609 | ptype = btf_type_resolve_ptr(btf, id, res_id); | |
610 | if (ptype && btf_type_is_func_proto(ptype)) | |
611 | return ptype; | |
612 | ||
613 | return NULL; | |
614 | } | |
615 | ||
1dc92851 DB |
616 | /* Types that act only as a source, not sink or intermediate |
617 | * type when resolving. | |
618 | */ | |
619 | static bool btf_type_is_resolve_source_only(const struct btf_type *t) | |
620 | { | |
621 | return btf_type_is_var(t) || | |
223f903e | 622 | btf_type_is_decl_tag(t) || |
1dc92851 DB |
623 | btf_type_is_datasec(t); |
624 | } | |
625 | ||
eb3f595d MKL |
626 | /* What types need to be resolved? |
627 | * | |
628 | * btf_type_is_modifier() is an obvious one. | |
629 | * | |
630 | * btf_type_is_struct() because its member refers to | |
631 | * another type (through member->type). | |
1dc92851 DB |
632 | * |
633 | * btf_type_is_var() because the variable refers to | |
634 | * another type. btf_type_is_datasec() holds multiple | |
635 | * btf_type_is_var() types that need resolving. | |
636 | * | |
eb3f595d MKL |
637 | * btf_type_is_array() because its element (array->type) |
638 | * refers to another type. Array can be thought of a | |
639 | * special case of struct while array just has the same | |
640 | * member-type repeated by array->nelems of times. | |
641 | */ | |
642 | static bool btf_type_needs_resolve(const struct btf_type *t) | |
643 | { | |
644 | return btf_type_is_modifier(t) || | |
1dc92851 DB |
645 | btf_type_is_ptr(t) || |
646 | btf_type_is_struct(t) || | |
647 | btf_type_is_array(t) || | |
648 | btf_type_is_var(t) || | |
d7e7b42f | 649 | btf_type_is_func(t) || |
223f903e | 650 | btf_type_is_decl_tag(t) || |
1dc92851 | 651 | btf_type_is_datasec(t); |
eb3f595d MKL |
652 | } |
653 | ||
654 | /* t->size can be used */ | |
655 | static bool btf_type_has_size(const struct btf_type *t) | |
656 | { | |
657 | switch (BTF_INFO_KIND(t->info)) { | |
658 | case BTF_KIND_INT: | |
659 | case BTF_KIND_STRUCT: | |
660 | case BTF_KIND_UNION: | |
661 | case BTF_KIND_ENUM: | |
1dc92851 | 662 | case BTF_KIND_DATASEC: |
b1828f0b | 663 | case BTF_KIND_FLOAT: |
6089fb32 | 664 | case BTF_KIND_ENUM64: |
eb3f595d MKL |
665 | return true; |
666 | } | |
667 | ||
668 | return false; | |
669 | } | |
670 | ||
69b693f0 MKL |
671 | static const char *btf_int_encoding_str(u8 encoding) |
672 | { | |
673 | if (encoding == 0) | |
674 | return "(none)"; | |
675 | else if (encoding == BTF_INT_SIGNED) | |
676 | return "SIGNED"; | |
677 | else if (encoding == BTF_INT_CHAR) | |
678 | return "CHAR"; | |
679 | else if (encoding == BTF_INT_BOOL) | |
680 | return "BOOL"; | |
69b693f0 MKL |
681 | else |
682 | return "UNKN"; | |
683 | } | |
684 | ||
69b693f0 MKL |
685 | static u32 btf_type_int(const struct btf_type *t) |
686 | { | |
687 | return *(u32 *)(t + 1); | |
688 | } | |
689 | ||
690 | static const struct btf_array *btf_type_array(const struct btf_type *t) | |
691 | { | |
692 | return (const struct btf_array *)(t + 1); | |
693 | } | |
694 | ||
69b693f0 MKL |
695 | static const struct btf_enum *btf_type_enum(const struct btf_type *t) |
696 | { | |
697 | return (const struct btf_enum *)(t + 1); | |
698 | } | |
699 | ||
1dc92851 DB |
700 | static const struct btf_var *btf_type_var(const struct btf_type *t) |
701 | { | |
702 | return (const struct btf_var *)(t + 1); | |
703 | } | |
704 | ||
223f903e | 705 | static const struct btf_decl_tag *btf_type_decl_tag(const struct btf_type *t) |
b5ea834d | 706 | { |
223f903e | 707 | return (const struct btf_decl_tag *)(t + 1); |
b5ea834d YS |
708 | } |
709 | ||
6089fb32 YS |
710 | static const struct btf_enum64 *btf_type_enum64(const struct btf_type *t) |
711 | { | |
712 | return (const struct btf_enum64 *)(t + 1); | |
713 | } | |
714 | ||
69b693f0 MKL |
715 | static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t) |
716 | { | |
717 | return kind_ops[BTF_INFO_KIND(t->info)]; | |
718 | } | |
719 | ||
583c5318 | 720 | static bool btf_name_offset_valid(const struct btf *btf, u32 offset) |
69b693f0 | 721 | { |
951bb646 AN |
722 | if (!BTF_STR_OFFSET_VALID(offset)) |
723 | return false; | |
724 | ||
725 | while (offset < btf->start_str_off) | |
726 | btf = btf->base_btf; | |
727 | ||
728 | offset -= btf->start_str_off; | |
729 | return offset < btf->hdr.str_len; | |
69b693f0 MKL |
730 | } |
731 | ||
1dc92851 DB |
732 | static bool __btf_name_char_ok(char c, bool first, bool dot_ok) |
733 | { | |
734 | if ((first ? !isalpha(c) : | |
735 | !isalnum(c)) && | |
736 | c != '_' && | |
737 | ((c == '.' && !dot_ok) || | |
738 | c != '.')) | |
739 | return false; | |
740 | return true; | |
741 | } | |
742 | ||
951bb646 AN |
743 | static const char *btf_str_by_offset(const struct btf *btf, u32 offset) |
744 | { | |
745 | while (offset < btf->start_str_off) | |
746 | btf = btf->base_btf; | |
747 | ||
748 | offset -= btf->start_str_off; | |
749 | if (offset < btf->hdr.str_len) | |
750 | return &btf->strings[offset]; | |
751 | ||
752 | return NULL; | |
753 | } | |
754 | ||
1dc92851 | 755 | static bool __btf_name_valid(const struct btf *btf, u32 offset, bool dot_ok) |
2667a262 MKL |
756 | { |
757 | /* offset must be valid */ | |
951bb646 | 758 | const char *src = btf_str_by_offset(btf, offset); |
2667a262 MKL |
759 | const char *src_limit; |
760 | ||
1dc92851 | 761 | if (!__btf_name_char_ok(*src, true, dot_ok)) |
2667a262 MKL |
762 | return false; |
763 | ||
764 | /* set a limit on identifier length */ | |
765 | src_limit = src + KSYM_NAME_LEN; | |
766 | src++; | |
767 | while (*src && src < src_limit) { | |
1dc92851 | 768 | if (!__btf_name_char_ok(*src, false, dot_ok)) |
2667a262 MKL |
769 | return false; |
770 | src++; | |
771 | } | |
772 | ||
773 | return !*src; | |
774 | } | |
775 | ||
1dc92851 DB |
776 | /* Only C-style identifier is permitted. This can be relaxed if |
777 | * necessary. | |
778 | */ | |
779 | static bool btf_name_valid_identifier(const struct btf *btf, u32 offset) | |
780 | { | |
781 | return __btf_name_valid(btf, offset, false); | |
782 | } | |
783 | ||
784 | static bool btf_name_valid_section(const struct btf *btf, u32 offset) | |
785 | { | |
786 | return __btf_name_valid(btf, offset, true); | |
787 | } | |
788 | ||
23127b33 | 789 | static const char *__btf_name_by_offset(const struct btf *btf, u32 offset) |
69b693f0 | 790 | { |
951bb646 AN |
791 | const char *name; |
792 | ||
aea2f7b8 | 793 | if (!offset) |
69b693f0 | 794 | return "(anon)"; |
951bb646 AN |
795 | |
796 | name = btf_str_by_offset(btf, offset); | |
797 | return name ?: "(invalid-name-offset)"; | |
69b693f0 MKL |
798 | } |
799 | ||
23127b33 MKL |
800 | const char *btf_name_by_offset(const struct btf *btf, u32 offset) |
801 | { | |
951bb646 | 802 | return btf_str_by_offset(btf, offset); |
23127b33 MKL |
803 | } |
804 | ||
838e9690 | 805 | const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id) |
eb3f595d | 806 | { |
951bb646 AN |
807 | while (type_id < btf->start_id) |
808 | btf = btf->base_btf; | |
eb3f595d | 809 | |
951bb646 AN |
810 | type_id -= btf->start_id; |
811 | if (type_id >= btf->nr_types) | |
812 | return NULL; | |
eb3f595d MKL |
813 | return btf->types[type_id]; |
814 | } | |
84c6ac41 | 815 | EXPORT_SYMBOL_GPL(btf_type_by_id); |
eb3f595d | 816 | |
4ef5f574 MKL |
817 | /* |
818 | * Regular int is not a bit field and it must be either | |
b1e8818c | 819 | * u8/u16/u32/u64 or __int128. |
4ef5f574 MKL |
820 | */ |
821 | static bool btf_type_int_is_regular(const struct btf_type *t) | |
822 | { | |
36fc3c8c | 823 | u8 nr_bits, nr_bytes; |
4ef5f574 MKL |
824 | u32 int_data; |
825 | ||
826 | int_data = btf_type_int(t); | |
827 | nr_bits = BTF_INT_BITS(int_data); | |
828 | nr_bytes = BITS_ROUNDUP_BYTES(nr_bits); | |
829 | if (BITS_PER_BYTE_MASKED(nr_bits) || | |
830 | BTF_INT_OFFSET(int_data) || | |
831 | (nr_bytes != sizeof(u8) && nr_bytes != sizeof(u16) && | |
b1e8818c YS |
832 | nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64) && |
833 | nr_bytes != (2 * sizeof(u64)))) { | |
4ef5f574 MKL |
834 | return false; |
835 | } | |
836 | ||
837 | return true; | |
838 | } | |
839 | ||
9a1126b6 | 840 | /* |
ffa0c1cf YS |
841 | * Check that given struct member is a regular int with expected |
842 | * offset and size. | |
9a1126b6 | 843 | */ |
ffa0c1cf YS |
844 | bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s, |
845 | const struct btf_member *m, | |
846 | u32 expected_offset, u32 expected_size) | |
9a1126b6 | 847 | { |
ffa0c1cf YS |
848 | const struct btf_type *t; |
849 | u32 id, int_data; | |
850 | u8 nr_bits; | |
9a1126b6 | 851 | |
ffa0c1cf YS |
852 | id = m->type; |
853 | t = btf_type_id_size(btf, &id, NULL); | |
854 | if (!t || !btf_type_is_int(t)) | |
9a1126b6 RG |
855 | return false; |
856 | ||
857 | int_data = btf_type_int(t); | |
858 | nr_bits = BTF_INT_BITS(int_data); | |
ffa0c1cf YS |
859 | if (btf_type_kflag(s)) { |
860 | u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset); | |
861 | u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset); | |
862 | ||
863 | /* if kflag set, int should be a regular int and | |
864 | * bit offset should be at byte boundary. | |
865 | */ | |
866 | return !bitfield_size && | |
867 | BITS_ROUNDUP_BYTES(bit_offset) == expected_offset && | |
868 | BITS_ROUNDUP_BYTES(nr_bits) == expected_size; | |
869 | } | |
870 | ||
871 | if (BTF_INT_OFFSET(int_data) || | |
872 | BITS_PER_BYTE_MASKED(m->offset) || | |
873 | BITS_ROUNDUP_BYTES(m->offset) != expected_offset || | |
874 | BITS_PER_BYTE_MASKED(nr_bits) || | |
875 | BITS_ROUNDUP_BYTES(nr_bits) != expected_size) | |
9a1126b6 RG |
876 | return false; |
877 | ||
878 | return true; | |
879 | } | |
880 | ||
31d0bc81 AM |
881 | /* Similar to btf_type_skip_modifiers() but does not skip typedefs. */ |
882 | static const struct btf_type *btf_type_skip_qualifiers(const struct btf *btf, | |
883 | u32 id) | |
884 | { | |
885 | const struct btf_type *t = btf_type_by_id(btf, id); | |
886 | ||
887 | while (btf_type_is_modifier(t) && | |
888 | BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF) { | |
31d0bc81 AM |
889 | t = btf_type_by_id(btf, t->type); |
890 | } | |
891 | ||
892 | return t; | |
893 | } | |
894 | ||
895 | #define BTF_SHOW_MAX_ITER 10 | |
896 | ||
897 | #define BTF_KIND_BIT(kind) (1ULL << kind) | |
898 | ||
899 | /* | |
900 | * Populate show->state.name with type name information. | |
901 | * Format of type name is | |
902 | * | |
903 | * [.member_name = ] (type_name) | |
904 | */ | |
905 | static const char *btf_show_name(struct btf_show *show) | |
906 | { | |
907 | /* BTF_MAX_ITER array suffixes "[]" */ | |
908 | const char *array_suffixes = "[][][][][][][][][][]"; | |
909 | const char *array_suffix = &array_suffixes[strlen(array_suffixes)]; | |
910 | /* BTF_MAX_ITER pointer suffixes "*" */ | |
911 | const char *ptr_suffixes = "**********"; | |
912 | const char *ptr_suffix = &ptr_suffixes[strlen(ptr_suffixes)]; | |
913 | const char *name = NULL, *prefix = "", *parens = ""; | |
914 | const struct btf_member *m = show->state.member; | |
73b6eae5 | 915 | const struct btf_type *t; |
31d0bc81 AM |
916 | const struct btf_array *array; |
917 | u32 id = show->state.type_id; | |
918 | const char *member = NULL; | |
919 | bool show_member = false; | |
920 | u64 kinds = 0; | |
921 | int i; | |
922 | ||
923 | show->state.name[0] = '\0'; | |
924 | ||
925 | /* | |
926 | * Don't show type name if we're showing an array member; | |
927 | * in that case we show the array type so don't need to repeat | |
928 | * ourselves for each member. | |
929 | */ | |
930 | if (show->state.array_member) | |
931 | return ""; | |
932 | ||
933 | /* Retrieve member name, if any. */ | |
934 | if (m) { | |
935 | member = btf_name_by_offset(show->btf, m->name_off); | |
936 | show_member = strlen(member) > 0; | |
937 | id = m->type; | |
938 | } | |
939 | ||
940 | /* | |
941 | * Start with type_id, as we have resolved the struct btf_type * | |
942 | * via btf_modifier_show() past the parent typedef to the child | |
943 | * struct, int etc it is defined as. In such cases, the type_id | |
944 | * still represents the starting type while the struct btf_type * | |
945 | * in our show->state points at the resolved type of the typedef. | |
946 | */ | |
947 | t = btf_type_by_id(show->btf, id); | |
948 | if (!t) | |
949 | return ""; | |
950 | ||
951 | /* | |
952 | * The goal here is to build up the right number of pointer and | |
953 | * array suffixes while ensuring the type name for a typedef | |
954 | * is represented. Along the way we accumulate a list of | |
955 | * BTF kinds we have encountered, since these will inform later | |
956 | * display; for example, pointer types will not require an | |
957 | * opening "{" for struct, we will just display the pointer value. | |
958 | * | |
959 | * We also want to accumulate the right number of pointer or array | |
960 | * indices in the format string while iterating until we get to | |
961 | * the typedef/pointee/array member target type. | |
962 | * | |
963 | * We start by pointing at the end of pointer and array suffix | |
964 | * strings; as we accumulate pointers and arrays we move the pointer | |
965 | * or array string backwards so it will show the expected number of | |
966 | * '*' or '[]' for the type. BTF_SHOW_MAX_ITER of nesting of pointers | |
967 | * and/or arrays and typedefs are supported as a precaution. | |
968 | * | |
969 | * We also want to get typedef name while proceeding to resolve | |
970 | * type it points to so that we can add parentheses if it is a | |
971 | * "typedef struct" etc. | |
972 | */ | |
973 | for (i = 0; i < BTF_SHOW_MAX_ITER; i++) { | |
974 | ||
975 | switch (BTF_INFO_KIND(t->info)) { | |
976 | case BTF_KIND_TYPEDEF: | |
977 | if (!name) | |
978 | name = btf_name_by_offset(show->btf, | |
979 | t->name_off); | |
980 | kinds |= BTF_KIND_BIT(BTF_KIND_TYPEDEF); | |
981 | id = t->type; | |
982 | break; | |
983 | case BTF_KIND_ARRAY: | |
984 | kinds |= BTF_KIND_BIT(BTF_KIND_ARRAY); | |
985 | parens = "["; | |
986 | if (!t) | |
987 | return ""; | |
988 | array = btf_type_array(t); | |
989 | if (array_suffix > array_suffixes) | |
990 | array_suffix -= 2; | |
991 | id = array->type; | |
992 | break; | |
993 | case BTF_KIND_PTR: | |
994 | kinds |= BTF_KIND_BIT(BTF_KIND_PTR); | |
995 | if (ptr_suffix > ptr_suffixes) | |
996 | ptr_suffix -= 1; | |
997 | id = t->type; | |
998 | break; | |
999 | default: | |
1000 | id = 0; | |
1001 | break; | |
1002 | } | |
1003 | if (!id) | |
1004 | break; | |
1005 | t = btf_type_skip_qualifiers(show->btf, id); | |
1006 | } | |
1007 | /* We may not be able to represent this type; bail to be safe */ | |
1008 | if (i == BTF_SHOW_MAX_ITER) | |
1009 | return ""; | |
1010 | ||
1011 | if (!name) | |
1012 | name = btf_name_by_offset(show->btf, t->name_off); | |
1013 | ||
1014 | switch (BTF_INFO_KIND(t->info)) { | |
1015 | case BTF_KIND_STRUCT: | |
1016 | case BTF_KIND_UNION: | |
1017 | prefix = BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT ? | |
1018 | "struct" : "union"; | |
1019 | /* if it's an array of struct/union, parens is already set */ | |
1020 | if (!(kinds & (BTF_KIND_BIT(BTF_KIND_ARRAY)))) | |
1021 | parens = "{"; | |
1022 | break; | |
1023 | case BTF_KIND_ENUM: | |
6089fb32 | 1024 | case BTF_KIND_ENUM64: |
31d0bc81 AM |
1025 | prefix = "enum"; |
1026 | break; | |
1027 | default: | |
1028 | break; | |
1029 | } | |
1030 | ||
1031 | /* pointer does not require parens */ | |
1032 | if (kinds & BTF_KIND_BIT(BTF_KIND_PTR)) | |
1033 | parens = ""; | |
1034 | /* typedef does not require struct/union/enum prefix */ | |
1035 | if (kinds & BTF_KIND_BIT(BTF_KIND_TYPEDEF)) | |
1036 | prefix = ""; | |
1037 | ||
1038 | if (!name) | |
1039 | name = ""; | |
1040 | ||
1041 | /* Even if we don't want type name info, we want parentheses etc */ | |
1042 | if (show->flags & BTF_SHOW_NONAME) | |
1043 | snprintf(show->state.name, sizeof(show->state.name), "%s", | |
1044 | parens); | |
1045 | else | |
1046 | snprintf(show->state.name, sizeof(show->state.name), | |
1047 | "%s%s%s(%s%s%s%s%s%s)%s", | |
1048 | /* first 3 strings comprise ".member = " */ | |
1049 | show_member ? "." : "", | |
1050 | show_member ? member : "", | |
1051 | show_member ? " = " : "", | |
1052 | /* ...next is our prefix (struct, enum, etc) */ | |
1053 | prefix, | |
1054 | strlen(prefix) > 0 && strlen(name) > 0 ? " " : "", | |
1055 | /* ...this is the type name itself */ | |
1056 | name, | |
1057 | /* ...suffixed by the appropriate '*', '[]' suffixes */ | |
1058 | strlen(ptr_suffix) > 0 ? " " : "", ptr_suffix, | |
1059 | array_suffix, parens); | |
1060 | ||
1061 | return show->state.name; | |
1062 | } | |
1063 | ||
1064 | static const char *__btf_show_indent(struct btf_show *show) | |
1065 | { | |
1066 | const char *indents = " "; | |
1067 | const char *indent = &indents[strlen(indents)]; | |
1068 | ||
1069 | if ((indent - show->state.depth) >= indents) | |
1070 | return indent - show->state.depth; | |
1071 | return indents; | |
1072 | } | |
1073 | ||
1074 | static const char *btf_show_indent(struct btf_show *show) | |
1075 | { | |
1076 | return show->flags & BTF_SHOW_COMPACT ? "" : __btf_show_indent(show); | |
1077 | } | |
1078 | ||
1079 | static const char *btf_show_newline(struct btf_show *show) | |
1080 | { | |
1081 | return show->flags & BTF_SHOW_COMPACT ? "" : "\n"; | |
1082 | } | |
1083 | ||
1084 | static const char *btf_show_delim(struct btf_show *show) | |
1085 | { | |
1086 | if (show->state.depth == 0) | |
1087 | return ""; | |
1088 | ||
1089 | if ((show->flags & BTF_SHOW_COMPACT) && show->state.type && | |
1090 | BTF_INFO_KIND(show->state.type->info) == BTF_KIND_UNION) | |
1091 | return "|"; | |
1092 | ||
1093 | return ","; | |
1094 | } | |
1095 | ||
1096 | __printf(2, 3) static void btf_show(struct btf_show *show, const char *fmt, ...) | |
1097 | { | |
1098 | va_list args; | |
1099 | ||
1100 | if (!show->state.depth_check) { | |
1101 | va_start(args, fmt); | |
1102 | show->showfn(show, fmt, args); | |
1103 | va_end(args); | |
1104 | } | |
1105 | } | |
1106 | ||
1107 | /* Macros are used here as btf_show_type_value[s]() prepends and appends | |
1108 | * format specifiers to the format specifier passed in; these do the work of | |
1109 | * adding indentation, delimiters etc while the caller simply has to specify | |
1110 | * the type value(s) in the format specifier + value(s). | |
1111 | */ | |
1112 | #define btf_show_type_value(show, fmt, value) \ | |
1113 | do { \ | |
a2a5580f BD |
1114 | if ((value) != (__typeof__(value))0 || \ |
1115 | (show->flags & BTF_SHOW_ZERO) || \ | |
31d0bc81 AM |
1116 | show->state.depth == 0) { \ |
1117 | btf_show(show, "%s%s" fmt "%s%s", \ | |
1118 | btf_show_indent(show), \ | |
1119 | btf_show_name(show), \ | |
1120 | value, btf_show_delim(show), \ | |
1121 | btf_show_newline(show)); \ | |
1122 | if (show->state.depth > show->state.depth_to_show) \ | |
1123 | show->state.depth_to_show = show->state.depth; \ | |
1124 | } \ | |
1125 | } while (0) | |
1126 | ||
1127 | #define btf_show_type_values(show, fmt, ...) \ | |
1128 | do { \ | |
1129 | btf_show(show, "%s%s" fmt "%s%s", btf_show_indent(show), \ | |
1130 | btf_show_name(show), \ | |
1131 | __VA_ARGS__, btf_show_delim(show), \ | |
1132 | btf_show_newline(show)); \ | |
1133 | if (show->state.depth > show->state.depth_to_show) \ | |
1134 | show->state.depth_to_show = show->state.depth; \ | |
1135 | } while (0) | |
1136 | ||
1137 | /* How much is left to copy to safe buffer after @data? */ | |
1138 | static int btf_show_obj_size_left(struct btf_show *show, void *data) | |
1139 | { | |
1140 | return show->obj.head + show->obj.size - data; | |
1141 | } | |
1142 | ||
1143 | /* Is object pointed to by @data of @size already copied to our safe buffer? */ | |
1144 | static bool btf_show_obj_is_safe(struct btf_show *show, void *data, int size) | |
1145 | { | |
1146 | return data >= show->obj.data && | |
1147 | (data + size) < (show->obj.data + BTF_SHOW_OBJ_SAFE_SIZE); | |
1148 | } | |
1149 | ||
1150 | /* | |
1151 | * If object pointed to by @data of @size falls within our safe buffer, return | |
1152 | * the equivalent pointer to the same safe data. Assumes | |
1153 | * copy_from_kernel_nofault() has already happened and our safe buffer is | |
1154 | * populated. | |
1155 | */ | |
1156 | static void *__btf_show_obj_safe(struct btf_show *show, void *data, int size) | |
1157 | { | |
1158 | if (btf_show_obj_is_safe(show, data, size)) | |
1159 | return show->obj.safe + (data - show->obj.data); | |
1160 | return NULL; | |
1161 | } | |
1162 | ||
1163 | /* | |
1164 | * Return a safe-to-access version of data pointed to by @data. | |
1165 | * We do this by copying the relevant amount of information | |
1166 | * to the struct btf_show obj.safe buffer using copy_from_kernel_nofault(). | |
1167 | * | |
1168 | * If BTF_SHOW_UNSAFE is specified, just return data as-is; no | |
1169 | * safe copy is needed. | |
1170 | * | |
1171 | * Otherwise we need to determine if we have the required amount | |
1172 | * of data (determined by the @data pointer and the size of the | |
1173 | * largest base type we can encounter (represented by | |
1174 | * BTF_SHOW_OBJ_BASE_TYPE_SIZE). Having that much data ensures | |
1175 | * that we will be able to print some of the current object, | |
1176 | * and if more is needed a copy will be triggered. | |
1177 | * Some objects such as structs will not fit into the buffer; | |
1178 | * in such cases additional copies when we iterate over their | |
1179 | * members may be needed. | |
1180 | * | |
1181 | * btf_show_obj_safe() is used to return a safe buffer for | |
1182 | * btf_show_start_type(); this ensures that as we recurse into | |
1183 | * nested types we always have safe data for the given type. | |
1184 | * This approach is somewhat wasteful; it's possible for example | |
1185 | * that when iterating over a large union we'll end up copying the | |
1186 | * same data repeatedly, but the goal is safety not performance. | |
1187 | * We use stack data as opposed to per-CPU buffers because the | |
1188 | * iteration over a type can take some time, and preemption handling | |
1189 | * would greatly complicate use of the safe buffer. | |
1190 | */ | |
1191 | static void *btf_show_obj_safe(struct btf_show *show, | |
1192 | const struct btf_type *t, | |
1193 | void *data) | |
1194 | { | |
1195 | const struct btf_type *rt; | |
1196 | int size_left, size; | |
1197 | void *safe = NULL; | |
1198 | ||
1199 | if (show->flags & BTF_SHOW_UNSAFE) | |
1200 | return data; | |
1201 | ||
1202 | rt = btf_resolve_size(show->btf, t, &size); | |
1203 | if (IS_ERR(rt)) { | |
1204 | show->state.status = PTR_ERR(rt); | |
1205 | return NULL; | |
1206 | } | |
1207 | ||
1208 | /* | |
1209 | * Is this toplevel object? If so, set total object size and | |
1210 | * initialize pointers. Otherwise check if we still fall within | |
1211 | * our safe object data. | |
1212 | */ | |
1213 | if (show->state.depth == 0) { | |
1214 | show->obj.size = size; | |
1215 | show->obj.head = data; | |
1216 | } else { | |
1217 | /* | |
1218 | * If the size of the current object is > our remaining | |
1219 | * safe buffer we _may_ need to do a new copy. However | |
1220 | * consider the case of a nested struct; it's size pushes | |
1221 | * us over the safe buffer limit, but showing any individual | |
1222 | * struct members does not. In such cases, we don't need | |
1223 | * to initiate a fresh copy yet; however we definitely need | |
1224 | * at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes left | |
1225 | * in our buffer, regardless of the current object size. | |
1226 | * The logic here is that as we resolve types we will | |
1227 | * hit a base type at some point, and we need to be sure | |
1228 | * the next chunk of data is safely available to display | |
1229 | * that type info safely. We cannot rely on the size of | |
1230 | * the current object here because it may be much larger | |
1231 | * than our current buffer (e.g. task_struct is 8k). | |
1232 | * All we want to do here is ensure that we can print the | |
1233 | * next basic type, which we can if either | |
1234 | * - the current type size is within the safe buffer; or | |
1235 | * - at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes are left in | |
1236 | * the safe buffer. | |
1237 | */ | |
1238 | safe = __btf_show_obj_safe(show, data, | |
1239 | min(size, | |
1240 | BTF_SHOW_OBJ_BASE_TYPE_SIZE)); | |
1241 | } | |
1242 | ||
1243 | /* | |
1244 | * We need a new copy to our safe object, either because we haven't | |
8fb33b60 | 1245 | * yet copied and are initializing safe data, or because the data |
31d0bc81 AM |
1246 | * we want falls outside the boundaries of the safe object. |
1247 | */ | |
1248 | if (!safe) { | |
1249 | size_left = btf_show_obj_size_left(show, data); | |
1250 | if (size_left > BTF_SHOW_OBJ_SAFE_SIZE) | |
1251 | size_left = BTF_SHOW_OBJ_SAFE_SIZE; | |
1252 | show->state.status = copy_from_kernel_nofault(show->obj.safe, | |
1253 | data, size_left); | |
1254 | if (!show->state.status) { | |
1255 | show->obj.data = data; | |
1256 | safe = show->obj.safe; | |
1257 | } | |
1258 | } | |
1259 | ||
1260 | return safe; | |
1261 | } | |
1262 | ||
1263 | /* | |
1264 | * Set the type we are starting to show and return a safe data pointer | |
1265 | * to be used for showing the associated data. | |
1266 | */ | |
1267 | static void *btf_show_start_type(struct btf_show *show, | |
1268 | const struct btf_type *t, | |
1269 | u32 type_id, void *data) | |
1270 | { | |
1271 | show->state.type = t; | |
1272 | show->state.type_id = type_id; | |
1273 | show->state.name[0] = '\0'; | |
1274 | ||
1275 | return btf_show_obj_safe(show, t, data); | |
1276 | } | |
1277 | ||
1278 | static void btf_show_end_type(struct btf_show *show) | |
1279 | { | |
1280 | show->state.type = NULL; | |
1281 | show->state.type_id = 0; | |
1282 | show->state.name[0] = '\0'; | |
1283 | } | |
1284 | ||
1285 | static void *btf_show_start_aggr_type(struct btf_show *show, | |
1286 | const struct btf_type *t, | |
1287 | u32 type_id, void *data) | |
1288 | { | |
1289 | void *safe_data = btf_show_start_type(show, t, type_id, data); | |
1290 | ||
1291 | if (!safe_data) | |
1292 | return safe_data; | |
1293 | ||
1294 | btf_show(show, "%s%s%s", btf_show_indent(show), | |
1295 | btf_show_name(show), | |
1296 | btf_show_newline(show)); | |
1297 | show->state.depth++; | |
1298 | return safe_data; | |
1299 | } | |
1300 | ||
1301 | static void btf_show_end_aggr_type(struct btf_show *show, | |
1302 | const char *suffix) | |
1303 | { | |
1304 | show->state.depth--; | |
1305 | btf_show(show, "%s%s%s%s", btf_show_indent(show), suffix, | |
1306 | btf_show_delim(show), btf_show_newline(show)); | |
1307 | btf_show_end_type(show); | |
1308 | } | |
1309 | ||
1310 | static void btf_show_start_member(struct btf_show *show, | |
1311 | const struct btf_member *m) | |
1312 | { | |
1313 | show->state.member = m; | |
1314 | } | |
1315 | ||
1316 | static void btf_show_start_array_member(struct btf_show *show) | |
1317 | { | |
1318 | show->state.array_member = 1; | |
1319 | btf_show_start_member(show, NULL); | |
1320 | } | |
1321 | ||
1322 | static void btf_show_end_member(struct btf_show *show) | |
1323 | { | |
1324 | show->state.member = NULL; | |
1325 | } | |
1326 | ||
1327 | static void btf_show_end_array_member(struct btf_show *show) | |
1328 | { | |
1329 | show->state.array_member = 0; | |
1330 | btf_show_end_member(show); | |
1331 | } | |
1332 | ||
1333 | static void *btf_show_start_array_type(struct btf_show *show, | |
1334 | const struct btf_type *t, | |
1335 | u32 type_id, | |
1336 | u16 array_encoding, | |
1337 | void *data) | |
1338 | { | |
1339 | show->state.array_encoding = array_encoding; | |
1340 | show->state.array_terminated = 0; | |
1341 | return btf_show_start_aggr_type(show, t, type_id, data); | |
1342 | } | |
1343 | ||
1344 | static void btf_show_end_array_type(struct btf_show *show) | |
1345 | { | |
1346 | show->state.array_encoding = 0; | |
1347 | show->state.array_terminated = 0; | |
1348 | btf_show_end_aggr_type(show, "]"); | |
1349 | } | |
1350 | ||
1351 | static void *btf_show_start_struct_type(struct btf_show *show, | |
1352 | const struct btf_type *t, | |
1353 | u32 type_id, | |
1354 | void *data) | |
1355 | { | |
1356 | return btf_show_start_aggr_type(show, t, type_id, data); | |
1357 | } | |
1358 | ||
1359 | static void btf_show_end_struct_type(struct btf_show *show) | |
1360 | { | |
1361 | btf_show_end_aggr_type(show, "}"); | |
1362 | } | |
1363 | ||
69b693f0 MKL |
1364 | __printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log, |
1365 | const char *fmt, ...) | |
1366 | { | |
1367 | va_list args; | |
1368 | ||
1369 | va_start(args, fmt); | |
1370 | bpf_verifier_vlog(log, fmt, args); | |
1371 | va_end(args); | |
1372 | } | |
1373 | ||
1374 | __printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env, | |
1375 | const char *fmt, ...) | |
1376 | { | |
1377 | struct bpf_verifier_log *log = &env->log; | |
1378 | va_list args; | |
1379 | ||
1380 | if (!bpf_verifier_log_needed(log)) | |
1381 | return; | |
1382 | ||
1383 | va_start(args, fmt); | |
1384 | bpf_verifier_vlog(log, fmt, args); | |
1385 | va_end(args); | |
1386 | } | |
1387 | ||
1388 | __printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env, | |
1389 | const struct btf_type *t, | |
1390 | bool log_details, | |
1391 | const char *fmt, ...) | |
1392 | { | |
1393 | struct bpf_verifier_log *log = &env->log; | |
69b693f0 MKL |
1394 | struct btf *btf = env->btf; |
1395 | va_list args; | |
1396 | ||
1397 | if (!bpf_verifier_log_needed(log)) | |
1398 | return; | |
1399 | ||
8580ac94 AS |
1400 | /* btf verifier prints all types it is processing via |
1401 | * btf_verifier_log_type(..., fmt = NULL). | |
1402 | * Skip those prints for in-kernel BTF verification. | |
1403 | */ | |
1404 | if (log->level == BPF_LOG_KERNEL && !fmt) | |
1405 | return; | |
1406 | ||
69b693f0 MKL |
1407 | __btf_verifier_log(log, "[%u] %s %s%s", |
1408 | env->log_type_id, | |
571f9738 | 1409 | btf_type_str(t), |
23127b33 | 1410 | __btf_name_by_offset(btf, t->name_off), |
69b693f0 MKL |
1411 | log_details ? " " : ""); |
1412 | ||
1413 | if (log_details) | |
1414 | btf_type_ops(t)->log_details(env, t); | |
1415 | ||
1416 | if (fmt && *fmt) { | |
1417 | __btf_verifier_log(log, " "); | |
1418 | va_start(args, fmt); | |
1419 | bpf_verifier_vlog(log, fmt, args); | |
1420 | va_end(args); | |
1421 | } | |
1422 | ||
1423 | __btf_verifier_log(log, "\n"); | |
1424 | } | |
1425 | ||
1426 | #define btf_verifier_log_type(env, t, ...) \ | |
1427 | __btf_verifier_log_type((env), (t), true, __VA_ARGS__) | |
1428 | #define btf_verifier_log_basic(env, t, ...) \ | |
1429 | __btf_verifier_log_type((env), (t), false, __VA_ARGS__) | |
1430 | ||
1431 | __printf(4, 5) | |
1432 | static void btf_verifier_log_member(struct btf_verifier_env *env, | |
1433 | const struct btf_type *struct_type, | |
1434 | const struct btf_member *member, | |
1435 | const char *fmt, ...) | |
1436 | { | |
1437 | struct bpf_verifier_log *log = &env->log; | |
1438 | struct btf *btf = env->btf; | |
1439 | va_list args; | |
1440 | ||
1441 | if (!bpf_verifier_log_needed(log)) | |
1442 | return; | |
1443 | ||
8580ac94 AS |
1444 | if (log->level == BPF_LOG_KERNEL && !fmt) |
1445 | return; | |
eb3f595d MKL |
1446 | /* The CHECK_META phase already did a btf dump. |
1447 | * | |
1448 | * If member is logged again, it must hit an error in | |
1449 | * parsing this member. It is useful to print out which | |
1450 | * struct this member belongs to. | |
1451 | */ | |
1452 | if (env->phase != CHECK_META) | |
1453 | btf_verifier_log_type(env, struct_type, NULL); | |
1454 | ||
9d5f9f70 YS |
1455 | if (btf_type_kflag(struct_type)) |
1456 | __btf_verifier_log(log, | |
1457 | "\t%s type_id=%u bitfield_size=%u bits_offset=%u", | |
1458 | __btf_name_by_offset(btf, member->name_off), | |
1459 | member->type, | |
1460 | BTF_MEMBER_BITFIELD_SIZE(member->offset), | |
1461 | BTF_MEMBER_BIT_OFFSET(member->offset)); | |
1462 | else | |
1463 | __btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u", | |
1464 | __btf_name_by_offset(btf, member->name_off), | |
1465 | member->type, member->offset); | |
69b693f0 MKL |
1466 | |
1467 | if (fmt && *fmt) { | |
1468 | __btf_verifier_log(log, " "); | |
1469 | va_start(args, fmt); | |
1470 | bpf_verifier_vlog(log, fmt, args); | |
1471 | va_end(args); | |
1472 | } | |
1473 | ||
1474 | __btf_verifier_log(log, "\n"); | |
1475 | } | |
1476 | ||
1dc92851 DB |
1477 | __printf(4, 5) |
1478 | static void btf_verifier_log_vsi(struct btf_verifier_env *env, | |
1479 | const struct btf_type *datasec_type, | |
1480 | const struct btf_var_secinfo *vsi, | |
1481 | const char *fmt, ...) | |
1482 | { | |
1483 | struct bpf_verifier_log *log = &env->log; | |
1484 | va_list args; | |
1485 | ||
1486 | if (!bpf_verifier_log_needed(log)) | |
1487 | return; | |
8580ac94 AS |
1488 | if (log->level == BPF_LOG_KERNEL && !fmt) |
1489 | return; | |
1dc92851 DB |
1490 | if (env->phase != CHECK_META) |
1491 | btf_verifier_log_type(env, datasec_type, NULL); | |
1492 | ||
1493 | __btf_verifier_log(log, "\t type_id=%u offset=%u size=%u", | |
1494 | vsi->type, vsi->offset, vsi->size); | |
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 | ||
f80442a4 MKL |
1505 | static void btf_verifier_log_hdr(struct btf_verifier_env *env, |
1506 | u32 btf_data_size) | |
69b693f0 MKL |
1507 | { |
1508 | struct bpf_verifier_log *log = &env->log; | |
1509 | const struct btf *btf = env->btf; | |
1510 | const struct btf_header *hdr; | |
1511 | ||
1512 | if (!bpf_verifier_log_needed(log)) | |
1513 | return; | |
1514 | ||
8580ac94 AS |
1515 | if (log->level == BPF_LOG_KERNEL) |
1516 | return; | |
f80442a4 | 1517 | hdr = &btf->hdr; |
69b693f0 MKL |
1518 | __btf_verifier_log(log, "magic: 0x%x\n", hdr->magic); |
1519 | __btf_verifier_log(log, "version: %u\n", hdr->version); | |
1520 | __btf_verifier_log(log, "flags: 0x%x\n", hdr->flags); | |
f80442a4 | 1521 | __btf_verifier_log(log, "hdr_len: %u\n", hdr->hdr_len); |
69b693f0 | 1522 | __btf_verifier_log(log, "type_off: %u\n", hdr->type_off); |
f80442a4 | 1523 | __btf_verifier_log(log, "type_len: %u\n", hdr->type_len); |
69b693f0 MKL |
1524 | __btf_verifier_log(log, "str_off: %u\n", hdr->str_off); |
1525 | __btf_verifier_log(log, "str_len: %u\n", hdr->str_len); | |
f80442a4 | 1526 | __btf_verifier_log(log, "btf_total_size: %u\n", btf_data_size); |
69b693f0 MKL |
1527 | } |
1528 | ||
1529 | static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t) | |
1530 | { | |
1531 | struct btf *btf = env->btf; | |
1532 | ||
951bb646 | 1533 | if (btf->types_size == btf->nr_types) { |
69b693f0 MKL |
1534 | /* Expand 'types' array */ |
1535 | ||
1536 | struct btf_type **new_types; | |
1537 | u32 expand_by, new_size; | |
1538 | ||
951bb646 | 1539 | if (btf->start_id + btf->types_size == BTF_MAX_TYPE) { |
69b693f0 MKL |
1540 | btf_verifier_log(env, "Exceeded max num of types"); |
1541 | return -E2BIG; | |
1542 | } | |
1543 | ||
1544 | expand_by = max_t(u32, btf->types_size >> 2, 16); | |
aea2f7b8 | 1545 | new_size = min_t(u32, BTF_MAX_TYPE, |
69b693f0 MKL |
1546 | btf->types_size + expand_by); |
1547 | ||
778e1cdd | 1548 | new_types = kvcalloc(new_size, sizeof(*new_types), |
69b693f0 MKL |
1549 | GFP_KERNEL | __GFP_NOWARN); |
1550 | if (!new_types) | |
1551 | return -ENOMEM; | |
1552 | ||
951bb646 AN |
1553 | if (btf->nr_types == 0) { |
1554 | if (!btf->base_btf) { | |
1555 | /* lazily init VOID type */ | |
1556 | new_types[0] = &btf_void; | |
1557 | btf->nr_types++; | |
1558 | } | |
1559 | } else { | |
69b693f0 | 1560 | memcpy(new_types, btf->types, |
951bb646 AN |
1561 | sizeof(*btf->types) * btf->nr_types); |
1562 | } | |
69b693f0 MKL |
1563 | |
1564 | kvfree(btf->types); | |
1565 | btf->types = new_types; | |
1566 | btf->types_size = new_size; | |
1567 | } | |
1568 | ||
951bb646 | 1569 | btf->types[btf->nr_types++] = t; |
69b693f0 MKL |
1570 | |
1571 | return 0; | |
1572 | } | |
1573 | ||
78958fca MKL |
1574 | static int btf_alloc_id(struct btf *btf) |
1575 | { | |
1576 | int id; | |
1577 | ||
1578 | idr_preload(GFP_KERNEL); | |
1579 | spin_lock_bh(&btf_idr_lock); | |
1580 | id = idr_alloc_cyclic(&btf_idr, btf, 1, INT_MAX, GFP_ATOMIC); | |
1581 | if (id > 0) | |
1582 | btf->id = id; | |
1583 | spin_unlock_bh(&btf_idr_lock); | |
1584 | idr_preload_end(); | |
1585 | ||
1586 | if (WARN_ON_ONCE(!id)) | |
1587 | return -ENOSPC; | |
1588 | ||
1589 | return id > 0 ? 0 : id; | |
1590 | } | |
1591 | ||
1592 | static void btf_free_id(struct btf *btf) | |
1593 | { | |
1594 | unsigned long flags; | |
1595 | ||
1596 | /* | |
1597 | * In map-in-map, calling map_delete_elem() on outer | |
1598 | * map will call bpf_map_put on the inner map. | |
1599 | * It will then eventually call btf_free_id() | |
1600 | * on the inner map. Some of the map_delete_elem() | |
1601 | * implementation may have irq disabled, so | |
1602 | * we need to use the _irqsave() version instead | |
1603 | * of the _bh() version. | |
1604 | */ | |
1605 | spin_lock_irqsave(&btf_idr_lock, flags); | |
1606 | idr_remove(&btf_idr, btf->id); | |
1607 | spin_unlock_irqrestore(&btf_idr_lock, flags); | |
1608 | } | |
1609 | ||
dee872e1 KKD |
1610 | static void btf_free_kfunc_set_tab(struct btf *btf) |
1611 | { | |
1612 | struct btf_kfunc_set_tab *tab = btf->kfunc_set_tab; | |
a4703e31 | 1613 | int hook; |
dee872e1 KKD |
1614 | |
1615 | if (!tab) | |
1616 | return; | |
1617 | /* For module BTF, we directly assign the sets being registered, so | |
1618 | * there is nothing to free except kfunc_set_tab. | |
1619 | */ | |
1620 | if (btf_is_module(btf)) | |
1621 | goto free_tab; | |
a4703e31 KKD |
1622 | for (hook = 0; hook < ARRAY_SIZE(tab->sets); hook++) |
1623 | kfree(tab->sets[hook]); | |
dee872e1 KKD |
1624 | free_tab: |
1625 | kfree(tab); | |
1626 | btf->kfunc_set_tab = NULL; | |
1627 | } | |
1628 | ||
5ce937d6 KKD |
1629 | static void btf_free_dtor_kfunc_tab(struct btf *btf) |
1630 | { | |
1631 | struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab; | |
1632 | ||
1633 | if (!tab) | |
1634 | return; | |
1635 | kfree(tab); | |
1636 | btf->dtor_kfunc_tab = NULL; | |
1637 | } | |
1638 | ||
8ffa5cc1 KKD |
1639 | static void btf_struct_metas_free(struct btf_struct_metas *tab) |
1640 | { | |
1641 | int i; | |
1642 | ||
1643 | if (!tab) | |
1644 | return; | |
1645 | for (i = 0; i < tab->cnt; i++) { | |
1646 | btf_record_free(tab->types[i].record); | |
1647 | kfree(tab->types[i].field_offs); | |
1648 | } | |
1649 | kfree(tab); | |
1650 | } | |
1651 | ||
1652 | static void btf_free_struct_meta_tab(struct btf *btf) | |
1653 | { | |
1654 | struct btf_struct_metas *tab = btf->struct_meta_tab; | |
1655 | ||
1656 | btf_struct_metas_free(tab); | |
1657 | btf->struct_meta_tab = NULL; | |
1658 | } | |
1659 | ||
69b693f0 MKL |
1660 | static void btf_free(struct btf *btf) |
1661 | { | |
8ffa5cc1 | 1662 | btf_free_struct_meta_tab(btf); |
5ce937d6 | 1663 | btf_free_dtor_kfunc_tab(btf); |
dee872e1 | 1664 | btf_free_kfunc_set_tab(btf); |
69b693f0 | 1665 | kvfree(btf->types); |
eb3f595d MKL |
1666 | kvfree(btf->resolved_sizes); |
1667 | kvfree(btf->resolved_ids); | |
69b693f0 MKL |
1668 | kvfree(btf->data); |
1669 | kfree(btf); | |
1670 | } | |
1671 | ||
78958fca | 1672 | static void btf_free_rcu(struct rcu_head *rcu) |
f56a653c | 1673 | { |
78958fca MKL |
1674 | struct btf *btf = container_of(rcu, struct btf, rcu); |
1675 | ||
1676 | btf_free(btf); | |
f56a653c MKL |
1677 | } |
1678 | ||
22dc4a0f AN |
1679 | void btf_get(struct btf *btf) |
1680 | { | |
1681 | refcount_inc(&btf->refcnt); | |
1682 | } | |
1683 | ||
f56a653c MKL |
1684 | void btf_put(struct btf *btf) |
1685 | { | |
78958fca MKL |
1686 | if (btf && refcount_dec_and_test(&btf->refcnt)) { |
1687 | btf_free_id(btf); | |
1688 | call_rcu(&btf->rcu, btf_free_rcu); | |
1689 | } | |
f56a653c MKL |
1690 | } |
1691 | ||
eb3f595d MKL |
1692 | static int env_resolve_init(struct btf_verifier_env *env) |
1693 | { | |
1694 | struct btf *btf = env->btf; | |
1695 | u32 nr_types = btf->nr_types; | |
1696 | u32 *resolved_sizes = NULL; | |
1697 | u32 *resolved_ids = NULL; | |
1698 | u8 *visit_states = NULL; | |
1699 | ||
951bb646 | 1700 | resolved_sizes = kvcalloc(nr_types, sizeof(*resolved_sizes), |
eb3f595d MKL |
1701 | GFP_KERNEL | __GFP_NOWARN); |
1702 | if (!resolved_sizes) | |
1703 | goto nomem; | |
1704 | ||
951bb646 | 1705 | resolved_ids = kvcalloc(nr_types, sizeof(*resolved_ids), |
eb3f595d MKL |
1706 | GFP_KERNEL | __GFP_NOWARN); |
1707 | if (!resolved_ids) | |
1708 | goto nomem; | |
1709 | ||
951bb646 | 1710 | visit_states = kvcalloc(nr_types, sizeof(*visit_states), |
eb3f595d MKL |
1711 | GFP_KERNEL | __GFP_NOWARN); |
1712 | if (!visit_states) | |
1713 | goto nomem; | |
1714 | ||
1715 | btf->resolved_sizes = resolved_sizes; | |
1716 | btf->resolved_ids = resolved_ids; | |
1717 | env->visit_states = visit_states; | |
1718 | ||
1719 | return 0; | |
1720 | ||
1721 | nomem: | |
1722 | kvfree(resolved_sizes); | |
1723 | kvfree(resolved_ids); | |
1724 | kvfree(visit_states); | |
1725 | return -ENOMEM; | |
1726 | } | |
1727 | ||
69b693f0 MKL |
1728 | static void btf_verifier_env_free(struct btf_verifier_env *env) |
1729 | { | |
eb3f595d | 1730 | kvfree(env->visit_states); |
69b693f0 MKL |
1731 | kfree(env); |
1732 | } | |
1733 | ||
eb3f595d MKL |
1734 | static bool env_type_is_resolve_sink(const struct btf_verifier_env *env, |
1735 | const struct btf_type *next_type) | |
1736 | { | |
1737 | switch (env->resolve_mode) { | |
1738 | case RESOLVE_TBD: | |
1739 | /* int, enum or void is a sink */ | |
1740 | return !btf_type_needs_resolve(next_type); | |
1741 | case RESOLVE_PTR: | |
2667a262 MKL |
1742 | /* int, enum, void, struct, array, func or func_proto is a sink |
1743 | * for ptr | |
1744 | */ | |
eb3f595d MKL |
1745 | return !btf_type_is_modifier(next_type) && |
1746 | !btf_type_is_ptr(next_type); | |
1747 | case RESOLVE_STRUCT_OR_ARRAY: | |
2667a262 MKL |
1748 | /* int, enum, void, ptr, func or func_proto is a sink |
1749 | * for struct and array | |
1750 | */ | |
eb3f595d MKL |
1751 | return !btf_type_is_modifier(next_type) && |
1752 | !btf_type_is_array(next_type) && | |
1753 | !btf_type_is_struct(next_type); | |
1754 | default: | |
53c8036c | 1755 | BUG(); |
eb3f595d MKL |
1756 | } |
1757 | } | |
1758 | ||
1759 | static bool env_type_is_resolved(const struct btf_verifier_env *env, | |
1760 | u32 type_id) | |
1761 | { | |
951bb646 AN |
1762 | /* base BTF types should be resolved by now */ |
1763 | if (type_id < env->btf->start_id) | |
1764 | return true; | |
1765 | ||
1766 | return env->visit_states[type_id - env->btf->start_id] == RESOLVED; | |
eb3f595d MKL |
1767 | } |
1768 | ||
1769 | static int env_stack_push(struct btf_verifier_env *env, | |
1770 | const struct btf_type *t, u32 type_id) | |
1771 | { | |
951bb646 | 1772 | const struct btf *btf = env->btf; |
eb3f595d MKL |
1773 | struct resolve_vertex *v; |
1774 | ||
1775 | if (env->top_stack == MAX_RESOLVE_DEPTH) | |
1776 | return -E2BIG; | |
1777 | ||
951bb646 AN |
1778 | if (type_id < btf->start_id |
1779 | || env->visit_states[type_id - btf->start_id] != NOT_VISITED) | |
eb3f595d MKL |
1780 | return -EEXIST; |
1781 | ||
951bb646 | 1782 | env->visit_states[type_id - btf->start_id] = VISITED; |
eb3f595d MKL |
1783 | |
1784 | v = &env->stack[env->top_stack++]; | |
1785 | v->t = t; | |
1786 | v->type_id = type_id; | |
1787 | v->next_member = 0; | |
1788 | ||
1789 | if (env->resolve_mode == RESOLVE_TBD) { | |
1790 | if (btf_type_is_ptr(t)) | |
1791 | env->resolve_mode = RESOLVE_PTR; | |
1792 | else if (btf_type_is_struct(t) || btf_type_is_array(t)) | |
1793 | env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY; | |
1794 | } | |
1795 | ||
1796 | return 0; | |
1797 | } | |
1798 | ||
1799 | static void env_stack_set_next_member(struct btf_verifier_env *env, | |
1800 | u16 next_member) | |
1801 | { | |
1802 | env->stack[env->top_stack - 1].next_member = next_member; | |
1803 | } | |
1804 | ||
1805 | static void env_stack_pop_resolved(struct btf_verifier_env *env, | |
1806 | u32 resolved_type_id, | |
1807 | u32 resolved_size) | |
1808 | { | |
1809 | u32 type_id = env->stack[--(env->top_stack)].type_id; | |
1810 | struct btf *btf = env->btf; | |
1811 | ||
951bb646 | 1812 | type_id -= btf->start_id; /* adjust to local type id */ |
eb3f595d MKL |
1813 | btf->resolved_sizes[type_id] = resolved_size; |
1814 | btf->resolved_ids[type_id] = resolved_type_id; | |
1815 | env->visit_states[type_id] = RESOLVED; | |
1816 | } | |
1817 | ||
1818 | static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env) | |
1819 | { | |
1820 | return env->top_stack ? &env->stack[env->top_stack - 1] : NULL; | |
1821 | } | |
1822 | ||
7e3617a7 MKL |
1823 | /* Resolve the size of a passed-in "type" |
1824 | * | |
1825 | * type: is an array (e.g. u32 array[x][y]) | |
1826 | * return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY, | |
1827 | * *type_size: (x * y * sizeof(u32)). Hence, *type_size always | |
1828 | * corresponds to the return type. | |
1829 | * *elem_type: u32 | |
69ff3047 | 1830 | * *elem_id: id of u32 |
7e3617a7 MKL |
1831 | * *total_nelems: (x * y). Hence, individual elem size is |
1832 | * (*type_size / *total_nelems) | |
887c31a3 | 1833 | * *type_id: id of type if it's changed within the function, 0 if not |
7e3617a7 MKL |
1834 | * |
1835 | * type: is not an array (e.g. const struct X) | |
1836 | * return type: type "struct X" | |
1837 | * *type_size: sizeof(struct X) | |
1838 | * *elem_type: same as return type ("struct X") | |
69ff3047 | 1839 | * *elem_id: 0 |
7e3617a7 | 1840 | * *total_nelems: 1 |
887c31a3 | 1841 | * *type_id: id of type if it's changed within the function, 0 if not |
7e3617a7 | 1842 | */ |
6298399b JO |
1843 | static const struct btf_type * |
1844 | __btf_resolve_size(const struct btf *btf, const struct btf_type *type, | |
1845 | u32 *type_size, const struct btf_type **elem_type, | |
887c31a3 | 1846 | u32 *elem_id, u32 *total_nelems, u32 *type_id) |
7e3617a7 MKL |
1847 | { |
1848 | const struct btf_type *array_type = NULL; | |
69ff3047 | 1849 | const struct btf_array *array = NULL; |
887c31a3 | 1850 | u32 i, size, nelems = 1, id = 0; |
7e3617a7 MKL |
1851 | |
1852 | for (i = 0; i < MAX_RESOLVE_DEPTH; i++) { | |
1853 | switch (BTF_INFO_KIND(type->info)) { | |
1854 | /* type->size can be used */ | |
1855 | case BTF_KIND_INT: | |
1856 | case BTF_KIND_STRUCT: | |
1857 | case BTF_KIND_UNION: | |
1858 | case BTF_KIND_ENUM: | |
b1828f0b | 1859 | case BTF_KIND_FLOAT: |
6089fb32 | 1860 | case BTF_KIND_ENUM64: |
7e3617a7 MKL |
1861 | size = type->size; |
1862 | goto resolved; | |
1863 | ||
1864 | case BTF_KIND_PTR: | |
1865 | size = sizeof(void *); | |
1866 | goto resolved; | |
1867 | ||
1868 | /* Modifiers */ | |
1869 | case BTF_KIND_TYPEDEF: | |
1870 | case BTF_KIND_VOLATILE: | |
1871 | case BTF_KIND_CONST: | |
1872 | case BTF_KIND_RESTRICT: | |
8c42d2fa | 1873 | case BTF_KIND_TYPE_TAG: |
887c31a3 | 1874 | id = type->type; |
7e3617a7 MKL |
1875 | type = btf_type_by_id(btf, type->type); |
1876 | break; | |
1877 | ||
1878 | case BTF_KIND_ARRAY: | |
1879 | if (!array_type) | |
1880 | array_type = type; | |
1881 | array = btf_type_array(type); | |
1882 | if (nelems && array->nelems > U32_MAX / nelems) | |
1883 | return ERR_PTR(-EINVAL); | |
1884 | nelems *= array->nelems; | |
1885 | type = btf_type_by_id(btf, array->type); | |
1886 | break; | |
1887 | ||
1888 | /* type without size */ | |
1889 | default: | |
1890 | return ERR_PTR(-EINVAL); | |
1891 | } | |
1892 | } | |
1893 | ||
1894 | return ERR_PTR(-EINVAL); | |
1895 | ||
1896 | resolved: | |
1897 | if (nelems && size > U32_MAX / nelems) | |
1898 | return ERR_PTR(-EINVAL); | |
1899 | ||
1900 | *type_size = nelems * size; | |
85d33df3 MKL |
1901 | if (total_nelems) |
1902 | *total_nelems = nelems; | |
1903 | if (elem_type) | |
1904 | *elem_type = type; | |
69ff3047 JO |
1905 | if (elem_id) |
1906 | *elem_id = array ? array->type : 0; | |
887c31a3 JO |
1907 | if (type_id && id) |
1908 | *type_id = id; | |
7e3617a7 MKL |
1909 | |
1910 | return array_type ? : type; | |
1911 | } | |
1912 | ||
6298399b JO |
1913 | const struct btf_type * |
1914 | btf_resolve_size(const struct btf *btf, const struct btf_type *type, | |
1915 | u32 *type_size) | |
1916 | { | |
887c31a3 | 1917 | return __btf_resolve_size(btf, type, type_size, NULL, NULL, NULL, NULL); |
6298399b JO |
1918 | } |
1919 | ||
951bb646 AN |
1920 | static u32 btf_resolved_type_id(const struct btf *btf, u32 type_id) |
1921 | { | |
1922 | while (type_id < btf->start_id) | |
1923 | btf = btf->base_btf; | |
1924 | ||
1925 | return btf->resolved_ids[type_id - btf->start_id]; | |
1926 | } | |
1927 | ||
eb3f595d MKL |
1928 | /* The input param "type_id" must point to a needs_resolve type */ |
1929 | static const struct btf_type *btf_type_id_resolve(const struct btf *btf, | |
1930 | u32 *type_id) | |
1931 | { | |
951bb646 | 1932 | *type_id = btf_resolved_type_id(btf, *type_id); |
eb3f595d MKL |
1933 | return btf_type_by_id(btf, *type_id); |
1934 | } | |
1935 | ||
951bb646 AN |
1936 | static u32 btf_resolved_type_size(const struct btf *btf, u32 type_id) |
1937 | { | |
1938 | while (type_id < btf->start_id) | |
1939 | btf = btf->base_btf; | |
1940 | ||
1941 | return btf->resolved_sizes[type_id - btf->start_id]; | |
1942 | } | |
1943 | ||
eb3f595d MKL |
1944 | const struct btf_type *btf_type_id_size(const struct btf *btf, |
1945 | u32 *type_id, u32 *ret_size) | |
1946 | { | |
1947 | const struct btf_type *size_type; | |
1948 | u32 size_type_id = *type_id; | |
1949 | u32 size = 0; | |
1950 | ||
1951 | size_type = btf_type_by_id(btf, size_type_id); | |
b47a0bd2 | 1952 | if (btf_type_nosize_or_null(size_type)) |
eb3f595d MKL |
1953 | return NULL; |
1954 | ||
1955 | if (btf_type_has_size(size_type)) { | |
1956 | size = size_type->size; | |
1957 | } else if (btf_type_is_array(size_type)) { | |
951bb646 | 1958 | size = btf_resolved_type_size(btf, size_type_id); |
eb3f595d MKL |
1959 | } else if (btf_type_is_ptr(size_type)) { |
1960 | size = sizeof(void *); | |
1961 | } else { | |
1dc92851 DB |
1962 | if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) && |
1963 | !btf_type_is_var(size_type))) | |
eb3f595d MKL |
1964 | return NULL; |
1965 | ||
951bb646 | 1966 | size_type_id = btf_resolved_type_id(btf, size_type_id); |
eb3f595d | 1967 | size_type = btf_type_by_id(btf, size_type_id); |
b47a0bd2 | 1968 | if (btf_type_nosize_or_null(size_type)) |
eb3f595d | 1969 | return NULL; |
1acc5d5c AN |
1970 | else if (btf_type_has_size(size_type)) |
1971 | size = size_type->size; | |
1972 | else if (btf_type_is_array(size_type)) | |
951bb646 | 1973 | size = btf_resolved_type_size(btf, size_type_id); |
1acc5d5c AN |
1974 | else if (btf_type_is_ptr(size_type)) |
1975 | size = sizeof(void *); | |
1976 | else | |
1977 | return NULL; | |
eb3f595d MKL |
1978 | } |
1979 | ||
1980 | *type_id = size_type_id; | |
1981 | if (ret_size) | |
1982 | *ret_size = size; | |
1983 | ||
1984 | return size_type; | |
1985 | } | |
1986 | ||
179cde8c MKL |
1987 | static int btf_df_check_member(struct btf_verifier_env *env, |
1988 | const struct btf_type *struct_type, | |
1989 | const struct btf_member *member, | |
1990 | const struct btf_type *member_type) | |
1991 | { | |
1992 | btf_verifier_log_basic(env, struct_type, | |
1993 | "Unsupported check_member"); | |
1994 | return -EINVAL; | |
1995 | } | |
1996 | ||
9d5f9f70 YS |
1997 | static int btf_df_check_kflag_member(struct btf_verifier_env *env, |
1998 | const struct btf_type *struct_type, | |
1999 | const struct btf_member *member, | |
2000 | const struct btf_type *member_type) | |
2001 | { | |
2002 | btf_verifier_log_basic(env, struct_type, | |
2003 | "Unsupported check_kflag_member"); | |
2004 | return -EINVAL; | |
2005 | } | |
2006 | ||
b1828f0b | 2007 | /* Used for ptr, array struct/union and float type members. |
9d5f9f70 YS |
2008 | * int, enum and modifier types have their specific callback functions. |
2009 | */ | |
2010 | static int btf_generic_check_kflag_member(struct btf_verifier_env *env, | |
2011 | const struct btf_type *struct_type, | |
2012 | const struct btf_member *member, | |
2013 | const struct btf_type *member_type) | |
2014 | { | |
2015 | if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) { | |
2016 | btf_verifier_log_member(env, struct_type, member, | |
2017 | "Invalid member bitfield_size"); | |
2018 | return -EINVAL; | |
2019 | } | |
2020 | ||
2021 | /* bitfield size is 0, so member->offset represents bit offset only. | |
2022 | * It is safe to call non kflag check_member variants. | |
2023 | */ | |
2024 | return btf_type_ops(member_type)->check_member(env, struct_type, | |
2025 | member, | |
2026 | member_type); | |
2027 | } | |
2028 | ||
eb3f595d MKL |
2029 | static int btf_df_resolve(struct btf_verifier_env *env, |
2030 | const struct resolve_vertex *v) | |
2031 | { | |
2032 | btf_verifier_log_basic(env, v->t, "Unsupported resolve"); | |
2033 | return -EINVAL; | |
2034 | } | |
2035 | ||
31d0bc81 AM |
2036 | static void btf_df_show(const struct btf *btf, const struct btf_type *t, |
2037 | u32 type_id, void *data, u8 bits_offsets, | |
2038 | struct btf_show *show) | |
b00b8dae | 2039 | { |
31d0bc81 | 2040 | btf_show(show, "<unsupported kind:%u>", BTF_INFO_KIND(t->info)); |
b00b8dae MKL |
2041 | } |
2042 | ||
179cde8c MKL |
2043 | static int btf_int_check_member(struct btf_verifier_env *env, |
2044 | const struct btf_type *struct_type, | |
2045 | const struct btf_member *member, | |
2046 | const struct btf_type *member_type) | |
2047 | { | |
2048 | u32 int_data = btf_type_int(member_type); | |
2049 | u32 struct_bits_off = member->offset; | |
2050 | u32 struct_size = struct_type->size; | |
2051 | u32 nr_copy_bits; | |
2052 | u32 bytes_offset; | |
2053 | ||
2054 | if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) { | |
2055 | btf_verifier_log_member(env, struct_type, member, | |
2056 | "bits_offset exceeds U32_MAX"); | |
2057 | return -EINVAL; | |
2058 | } | |
2059 | ||
2060 | struct_bits_off += BTF_INT_OFFSET(int_data); | |
2061 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2062 | nr_copy_bits = BTF_INT_BITS(int_data) + | |
2063 | BITS_PER_BYTE_MASKED(struct_bits_off); | |
2064 | ||
b1e8818c | 2065 | if (nr_copy_bits > BITS_PER_U128) { |
179cde8c | 2066 | btf_verifier_log_member(env, struct_type, member, |
b1e8818c | 2067 | "nr_copy_bits exceeds 128"); |
179cde8c MKL |
2068 | return -EINVAL; |
2069 | } | |
2070 | ||
2071 | if (struct_size < bytes_offset || | |
2072 | struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { | |
2073 | btf_verifier_log_member(env, struct_type, member, | |
2074 | "Member exceeds struct_size"); | |
2075 | return -EINVAL; | |
2076 | } | |
2077 | ||
2078 | return 0; | |
2079 | } | |
2080 | ||
9d5f9f70 YS |
2081 | static int btf_int_check_kflag_member(struct btf_verifier_env *env, |
2082 | const struct btf_type *struct_type, | |
2083 | const struct btf_member *member, | |
2084 | const struct btf_type *member_type) | |
2085 | { | |
2086 | u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset; | |
2087 | u32 int_data = btf_type_int(member_type); | |
2088 | u32 struct_size = struct_type->size; | |
2089 | u32 nr_copy_bits; | |
2090 | ||
2091 | /* a regular int type is required for the kflag int member */ | |
2092 | if (!btf_type_int_is_regular(member_type)) { | |
2093 | btf_verifier_log_member(env, struct_type, member, | |
2094 | "Invalid member base type"); | |
2095 | return -EINVAL; | |
2096 | } | |
2097 | ||
2098 | /* check sanity of bitfield size */ | |
2099 | nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); | |
2100 | struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); | |
2101 | nr_int_data_bits = BTF_INT_BITS(int_data); | |
2102 | if (!nr_bits) { | |
2103 | /* Not a bitfield member, member offset must be at byte | |
2104 | * boundary. | |
2105 | */ | |
2106 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2107 | btf_verifier_log_member(env, struct_type, member, | |
2108 | "Invalid member offset"); | |
2109 | return -EINVAL; | |
2110 | } | |
2111 | ||
2112 | nr_bits = nr_int_data_bits; | |
2113 | } else if (nr_bits > nr_int_data_bits) { | |
2114 | btf_verifier_log_member(env, struct_type, member, | |
2115 | "Invalid member bitfield_size"); | |
2116 | return -EINVAL; | |
2117 | } | |
2118 | ||
2119 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2120 | nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off); | |
b1e8818c | 2121 | if (nr_copy_bits > BITS_PER_U128) { |
9d5f9f70 | 2122 | btf_verifier_log_member(env, struct_type, member, |
b1e8818c | 2123 | "nr_copy_bits exceeds 128"); |
9d5f9f70 YS |
2124 | return -EINVAL; |
2125 | } | |
2126 | ||
2127 | if (struct_size < bytes_offset || | |
2128 | struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { | |
2129 | btf_verifier_log_member(env, struct_type, member, | |
2130 | "Member exceeds struct_size"); | |
2131 | return -EINVAL; | |
2132 | } | |
2133 | ||
2134 | return 0; | |
2135 | } | |
2136 | ||
69b693f0 MKL |
2137 | static s32 btf_int_check_meta(struct btf_verifier_env *env, |
2138 | const struct btf_type *t, | |
2139 | u32 meta_left) | |
2140 | { | |
2141 | u32 int_data, nr_bits, meta_needed = sizeof(int_data); | |
2142 | u16 encoding; | |
2143 | ||
2144 | if (meta_left < meta_needed) { | |
2145 | btf_verifier_log_basic(env, t, | |
2146 | "meta_left:%u meta_needed:%u", | |
2147 | meta_left, meta_needed); | |
2148 | return -EINVAL; | |
2149 | } | |
2150 | ||
2151 | if (btf_type_vlen(t)) { | |
2152 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2153 | return -EINVAL; | |
2154 | } | |
2155 | ||
9d5f9f70 YS |
2156 | if (btf_type_kflag(t)) { |
2157 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2158 | return -EINVAL; | |
2159 | } | |
2160 | ||
69b693f0 | 2161 | int_data = btf_type_int(t); |
aea2f7b8 MKL |
2162 | if (int_data & ~BTF_INT_MASK) { |
2163 | btf_verifier_log_basic(env, t, "Invalid int_data:%x", | |
2164 | int_data); | |
2165 | return -EINVAL; | |
2166 | } | |
2167 | ||
69b693f0 MKL |
2168 | nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data); |
2169 | ||
b1e8818c | 2170 | if (nr_bits > BITS_PER_U128) { |
69b693f0 | 2171 | btf_verifier_log_type(env, t, "nr_bits exceeds %zu", |
b1e8818c | 2172 | BITS_PER_U128); |
69b693f0 MKL |
2173 | return -EINVAL; |
2174 | } | |
2175 | ||
2176 | if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) { | |
2177 | btf_verifier_log_type(env, t, "nr_bits exceeds type_size"); | |
2178 | return -EINVAL; | |
2179 | } | |
2180 | ||
aea2f7b8 MKL |
2181 | /* |
2182 | * Only one of the encoding bits is allowed and it | |
2183 | * should be sufficient for the pretty print purpose (i.e. decoding). | |
2184 | * Multiple bits can be allowed later if it is found | |
2185 | * to be insufficient. | |
2186 | */ | |
69b693f0 MKL |
2187 | encoding = BTF_INT_ENCODING(int_data); |
2188 | if (encoding && | |
2189 | encoding != BTF_INT_SIGNED && | |
2190 | encoding != BTF_INT_CHAR && | |
aea2f7b8 | 2191 | encoding != BTF_INT_BOOL) { |
69b693f0 MKL |
2192 | btf_verifier_log_type(env, t, "Unsupported encoding"); |
2193 | return -ENOTSUPP; | |
2194 | } | |
2195 | ||
2196 | btf_verifier_log_type(env, t, NULL); | |
2197 | ||
2198 | return meta_needed; | |
2199 | } | |
2200 | ||
2201 | static void btf_int_log(struct btf_verifier_env *env, | |
2202 | const struct btf_type *t) | |
2203 | { | |
2204 | int int_data = btf_type_int(t); | |
2205 | ||
2206 | btf_verifier_log(env, | |
2207 | "size=%u bits_offset=%u nr_bits=%u encoding=%s", | |
2208 | t->size, BTF_INT_OFFSET(int_data), | |
2209 | BTF_INT_BITS(int_data), | |
2210 | btf_int_encoding_str(BTF_INT_ENCODING(int_data))); | |
2211 | } | |
2212 | ||
31d0bc81 | 2213 | static void btf_int128_print(struct btf_show *show, void *data) |
b1e8818c YS |
2214 | { |
2215 | /* data points to a __int128 number. | |
2216 | * Suppose | |
2217 | * int128_num = *(__int128 *)data; | |
2218 | * The below formulas shows what upper_num and lower_num represents: | |
2219 | * upper_num = int128_num >> 64; | |
2220 | * lower_num = int128_num & 0xffffffffFFFFFFFFULL; | |
2221 | */ | |
2222 | u64 upper_num, lower_num; | |
2223 | ||
2224 | #ifdef __BIG_ENDIAN_BITFIELD | |
2225 | upper_num = *(u64 *)data; | |
2226 | lower_num = *(u64 *)(data + 8); | |
2227 | #else | |
2228 | upper_num = *(u64 *)(data + 8); | |
2229 | lower_num = *(u64 *)data; | |
2230 | #endif | |
2231 | if (upper_num == 0) | |
31d0bc81 | 2232 | btf_show_type_value(show, "0x%llx", lower_num); |
b1e8818c | 2233 | else |
31d0bc81 AM |
2234 | btf_show_type_values(show, "0x%llx%016llx", upper_num, |
2235 | lower_num); | |
b1e8818c YS |
2236 | } |
2237 | ||
2238 | static void btf_int128_shift(u64 *print_num, u16 left_shift_bits, | |
2239 | u16 right_shift_bits) | |
2240 | { | |
2241 | u64 upper_num, lower_num; | |
2242 | ||
2243 | #ifdef __BIG_ENDIAN_BITFIELD | |
2244 | upper_num = print_num[0]; | |
2245 | lower_num = print_num[1]; | |
2246 | #else | |
2247 | upper_num = print_num[1]; | |
2248 | lower_num = print_num[0]; | |
2249 | #endif | |
2250 | ||
2251 | /* shake out un-needed bits by shift/or operations */ | |
2252 | if (left_shift_bits >= 64) { | |
2253 | upper_num = lower_num << (left_shift_bits - 64); | |
2254 | lower_num = 0; | |
2255 | } else { | |
2256 | upper_num = (upper_num << left_shift_bits) | | |
2257 | (lower_num >> (64 - left_shift_bits)); | |
2258 | lower_num = lower_num << left_shift_bits; | |
2259 | } | |
2260 | ||
2261 | if (right_shift_bits >= 64) { | |
2262 | lower_num = upper_num >> (right_shift_bits - 64); | |
2263 | upper_num = 0; | |
2264 | } else { | |
2265 | lower_num = (lower_num >> right_shift_bits) | | |
2266 | (upper_num << (64 - right_shift_bits)); | |
2267 | upper_num = upper_num >> right_shift_bits; | |
2268 | } | |
2269 | ||
2270 | #ifdef __BIG_ENDIAN_BITFIELD | |
2271 | print_num[0] = upper_num; | |
2272 | print_num[1] = lower_num; | |
2273 | #else | |
2274 | print_num[0] = lower_num; | |
2275 | print_num[1] = upper_num; | |
2276 | #endif | |
2277 | } | |
2278 | ||
31d0bc81 AM |
2279 | static void btf_bitfield_show(void *data, u8 bits_offset, |
2280 | u8 nr_bits, struct btf_show *show) | |
b00b8dae | 2281 | { |
b65f370d | 2282 | u16 left_shift_bits, right_shift_bits; |
36fc3c8c MKL |
2283 | u8 nr_copy_bytes; |
2284 | u8 nr_copy_bits; | |
b1e8818c | 2285 | u64 print_num[2] = {}; |
b00b8dae | 2286 | |
b00b8dae MKL |
2287 | nr_copy_bits = nr_bits + bits_offset; |
2288 | nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits); | |
2289 | ||
b1e8818c | 2290 | memcpy(print_num, data, nr_copy_bytes); |
b00b8dae | 2291 | |
b65f370d OK |
2292 | #ifdef __BIG_ENDIAN_BITFIELD |
2293 | left_shift_bits = bits_offset; | |
2294 | #else | |
b1e8818c | 2295 | left_shift_bits = BITS_PER_U128 - nr_copy_bits; |
b65f370d | 2296 | #endif |
b1e8818c | 2297 | right_shift_bits = BITS_PER_U128 - nr_bits; |
b00b8dae | 2298 | |
b1e8818c | 2299 | btf_int128_shift(print_num, left_shift_bits, right_shift_bits); |
31d0bc81 | 2300 | btf_int128_print(show, print_num); |
b00b8dae MKL |
2301 | } |
2302 | ||
9d5f9f70 | 2303 | |
31d0bc81 AM |
2304 | static void btf_int_bits_show(const struct btf *btf, |
2305 | const struct btf_type *t, | |
2306 | void *data, u8 bits_offset, | |
2307 | struct btf_show *show) | |
f97be3ab YS |
2308 | { |
2309 | u32 int_data = btf_type_int(t); | |
2310 | u8 nr_bits = BTF_INT_BITS(int_data); | |
2311 | u8 total_bits_offset; | |
2312 | ||
2313 | /* | |
2314 | * bits_offset is at most 7. | |
b1e8818c | 2315 | * BTF_INT_OFFSET() cannot exceed 128 bits. |
f97be3ab YS |
2316 | */ |
2317 | total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data); | |
17e3ac81 YS |
2318 | data += BITS_ROUNDDOWN_BYTES(total_bits_offset); |
2319 | bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset); | |
31d0bc81 | 2320 | btf_bitfield_show(data, bits_offset, nr_bits, show); |
f97be3ab YS |
2321 | } |
2322 | ||
31d0bc81 AM |
2323 | static void btf_int_show(const struct btf *btf, const struct btf_type *t, |
2324 | u32 type_id, void *data, u8 bits_offset, | |
2325 | struct btf_show *show) | |
b00b8dae MKL |
2326 | { |
2327 | u32 int_data = btf_type_int(t); | |
2328 | u8 encoding = BTF_INT_ENCODING(int_data); | |
2329 | bool sign = encoding & BTF_INT_SIGNED; | |
36fc3c8c | 2330 | u8 nr_bits = BTF_INT_BITS(int_data); |
31d0bc81 AM |
2331 | void *safe_data; |
2332 | ||
2333 | safe_data = btf_show_start_type(show, t, type_id, data); | |
2334 | if (!safe_data) | |
2335 | return; | |
b00b8dae MKL |
2336 | |
2337 | if (bits_offset || BTF_INT_OFFSET(int_data) || | |
2338 | BITS_PER_BYTE_MASKED(nr_bits)) { | |
31d0bc81 AM |
2339 | btf_int_bits_show(btf, t, safe_data, bits_offset, show); |
2340 | goto out; | |
b00b8dae MKL |
2341 | } |
2342 | ||
2343 | switch (nr_bits) { | |
b1e8818c | 2344 | case 128: |
31d0bc81 | 2345 | btf_int128_print(show, safe_data); |
b1e8818c | 2346 | break; |
b00b8dae MKL |
2347 | case 64: |
2348 | if (sign) | |
31d0bc81 | 2349 | btf_show_type_value(show, "%lld", *(s64 *)safe_data); |
b00b8dae | 2350 | else |
31d0bc81 | 2351 | btf_show_type_value(show, "%llu", *(u64 *)safe_data); |
b00b8dae MKL |
2352 | break; |
2353 | case 32: | |
2354 | if (sign) | |
31d0bc81 | 2355 | btf_show_type_value(show, "%d", *(s32 *)safe_data); |
b00b8dae | 2356 | else |
31d0bc81 | 2357 | btf_show_type_value(show, "%u", *(u32 *)safe_data); |
b00b8dae MKL |
2358 | break; |
2359 | case 16: | |
2360 | if (sign) | |
31d0bc81 | 2361 | btf_show_type_value(show, "%d", *(s16 *)safe_data); |
b00b8dae | 2362 | else |
31d0bc81 | 2363 | btf_show_type_value(show, "%u", *(u16 *)safe_data); |
b00b8dae MKL |
2364 | break; |
2365 | case 8: | |
31d0bc81 AM |
2366 | if (show->state.array_encoding == BTF_INT_CHAR) { |
2367 | /* check for null terminator */ | |
2368 | if (show->state.array_terminated) | |
2369 | break; | |
2370 | if (*(char *)data == '\0') { | |
2371 | show->state.array_terminated = 1; | |
2372 | break; | |
2373 | } | |
2374 | if (isprint(*(char *)data)) { | |
2375 | btf_show_type_value(show, "'%c'", | |
2376 | *(char *)safe_data); | |
2377 | break; | |
2378 | } | |
2379 | } | |
b00b8dae | 2380 | if (sign) |
31d0bc81 | 2381 | btf_show_type_value(show, "%d", *(s8 *)safe_data); |
b00b8dae | 2382 | else |
31d0bc81 | 2383 | btf_show_type_value(show, "%u", *(u8 *)safe_data); |
b00b8dae MKL |
2384 | break; |
2385 | default: | |
31d0bc81 AM |
2386 | btf_int_bits_show(btf, t, safe_data, bits_offset, show); |
2387 | break; | |
b00b8dae | 2388 | } |
31d0bc81 AM |
2389 | out: |
2390 | btf_show_end_type(show); | |
b00b8dae MKL |
2391 | } |
2392 | ||
69b693f0 MKL |
2393 | static const struct btf_kind_operations int_ops = { |
2394 | .check_meta = btf_int_check_meta, | |
eb3f595d | 2395 | .resolve = btf_df_resolve, |
179cde8c | 2396 | .check_member = btf_int_check_member, |
9d5f9f70 | 2397 | .check_kflag_member = btf_int_check_kflag_member, |
69b693f0 | 2398 | .log_details = btf_int_log, |
31d0bc81 | 2399 | .show = btf_int_show, |
69b693f0 MKL |
2400 | }; |
2401 | ||
179cde8c MKL |
2402 | static int btf_modifier_check_member(struct btf_verifier_env *env, |
2403 | const struct btf_type *struct_type, | |
2404 | const struct btf_member *member, | |
2405 | const struct btf_type *member_type) | |
2406 | { | |
2407 | const struct btf_type *resolved_type; | |
2408 | u32 resolved_type_id = member->type; | |
2409 | struct btf_member resolved_member; | |
2410 | struct btf *btf = env->btf; | |
2411 | ||
2412 | resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); | |
2413 | if (!resolved_type) { | |
2414 | btf_verifier_log_member(env, struct_type, member, | |
2415 | "Invalid member"); | |
2416 | return -EINVAL; | |
2417 | } | |
2418 | ||
2419 | resolved_member = *member; | |
2420 | resolved_member.type = resolved_type_id; | |
2421 | ||
2422 | return btf_type_ops(resolved_type)->check_member(env, struct_type, | |
2423 | &resolved_member, | |
2424 | resolved_type); | |
2425 | } | |
2426 | ||
9d5f9f70 YS |
2427 | static int btf_modifier_check_kflag_member(struct btf_verifier_env *env, |
2428 | const struct btf_type *struct_type, | |
2429 | const struct btf_member *member, | |
2430 | const struct btf_type *member_type) | |
2431 | { | |
2432 | const struct btf_type *resolved_type; | |
2433 | u32 resolved_type_id = member->type; | |
2434 | struct btf_member resolved_member; | |
2435 | struct btf *btf = env->btf; | |
2436 | ||
2437 | resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); | |
2438 | if (!resolved_type) { | |
2439 | btf_verifier_log_member(env, struct_type, member, | |
2440 | "Invalid member"); | |
2441 | return -EINVAL; | |
2442 | } | |
2443 | ||
2444 | resolved_member = *member; | |
2445 | resolved_member.type = resolved_type_id; | |
2446 | ||
2447 | return btf_type_ops(resolved_type)->check_kflag_member(env, struct_type, | |
2448 | &resolved_member, | |
2449 | resolved_type); | |
2450 | } | |
2451 | ||
179cde8c MKL |
2452 | static int btf_ptr_check_member(struct btf_verifier_env *env, |
2453 | const struct btf_type *struct_type, | |
2454 | const struct btf_member *member, | |
2455 | const struct btf_type *member_type) | |
2456 | { | |
2457 | u32 struct_size, struct_bits_off, bytes_offset; | |
2458 | ||
2459 | struct_size = struct_type->size; | |
2460 | struct_bits_off = member->offset; | |
2461 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2462 | ||
2463 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2464 | btf_verifier_log_member(env, struct_type, member, | |
2465 | "Member is not byte aligned"); | |
2466 | return -EINVAL; | |
2467 | } | |
2468 | ||
2469 | if (struct_size - bytes_offset < sizeof(void *)) { | |
2470 | btf_verifier_log_member(env, struct_type, member, | |
2471 | "Member exceeds struct_size"); | |
2472 | return -EINVAL; | |
2473 | } | |
2474 | ||
2475 | return 0; | |
2476 | } | |
2477 | ||
69b693f0 MKL |
2478 | static int btf_ref_type_check_meta(struct btf_verifier_env *env, |
2479 | const struct btf_type *t, | |
2480 | u32 meta_left) | |
2481 | { | |
8c42d2fa YS |
2482 | const char *value; |
2483 | ||
69b693f0 MKL |
2484 | if (btf_type_vlen(t)) { |
2485 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2486 | return -EINVAL; | |
2487 | } | |
2488 | ||
9d5f9f70 YS |
2489 | if (btf_type_kflag(t)) { |
2490 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2491 | return -EINVAL; | |
2492 | } | |
2493 | ||
aea2f7b8 | 2494 | if (!BTF_TYPE_ID_VALID(t->type)) { |
69b693f0 MKL |
2495 | btf_verifier_log_type(env, t, "Invalid type_id"); |
2496 | return -EINVAL; | |
2497 | } | |
2498 | ||
8c42d2fa | 2499 | /* typedef/type_tag type must have a valid name, and other ref types, |
eb04bbb6 YS |
2500 | * volatile, const, restrict, should have a null name. |
2501 | */ | |
2502 | if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) { | |
2503 | if (!t->name_off || | |
2504 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
2505 | btf_verifier_log_type(env, t, "Invalid name"); | |
2506 | return -EINVAL; | |
2507 | } | |
8c42d2fa YS |
2508 | } else if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPE_TAG) { |
2509 | value = btf_name_by_offset(env->btf, t->name_off); | |
2510 | if (!value || !value[0]) { | |
2511 | btf_verifier_log_type(env, t, "Invalid name"); | |
2512 | return -EINVAL; | |
2513 | } | |
eb04bbb6 YS |
2514 | } else { |
2515 | if (t->name_off) { | |
2516 | btf_verifier_log_type(env, t, "Invalid name"); | |
2517 | return -EINVAL; | |
2518 | } | |
2519 | } | |
2520 | ||
69b693f0 MKL |
2521 | btf_verifier_log_type(env, t, NULL); |
2522 | ||
2523 | return 0; | |
2524 | } | |
2525 | ||
eb3f595d MKL |
2526 | static int btf_modifier_resolve(struct btf_verifier_env *env, |
2527 | const struct resolve_vertex *v) | |
2528 | { | |
2529 | const struct btf_type *t = v->t; | |
2530 | const struct btf_type *next_type; | |
2531 | u32 next_type_id = t->type; | |
2532 | struct btf *btf = env->btf; | |
eb3f595d MKL |
2533 | |
2534 | next_type = btf_type_by_id(btf, next_type_id); | |
1dc92851 | 2535 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
eb3f595d MKL |
2536 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2537 | return -EINVAL; | |
2538 | } | |
2539 | ||
eb3f595d MKL |
2540 | if (!env_type_is_resolve_sink(env, next_type) && |
2541 | !env_type_is_resolved(env, next_type_id)) | |
2542 | return env_stack_push(env, next_type, next_type_id); | |
2543 | ||
2544 | /* Figure out the resolved next_type_id with size. | |
2545 | * They will be stored in the current modifier's | |
2546 | * resolved_ids and resolved_sizes such that it can | |
2547 | * save us a few type-following when we use it later (e.g. in | |
2548 | * pretty print). | |
2549 | */ | |
1acc5d5c | 2550 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
2667a262 MKL |
2551 | if (env_type_is_resolved(env, next_type_id)) |
2552 | next_type = btf_type_id_resolve(btf, &next_type_id); | |
2553 | ||
2554 | /* "typedef void new_void", "const void"...etc */ | |
2555 | if (!btf_type_is_void(next_type) && | |
81f5c6f5 YS |
2556 | !btf_type_is_fwd(next_type) && |
2557 | !btf_type_is_func_proto(next_type)) { | |
2667a262 MKL |
2558 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2559 | return -EINVAL; | |
2560 | } | |
eb3f595d MKL |
2561 | } |
2562 | ||
1acc5d5c | 2563 | env_stack_pop_resolved(env, next_type_id, 0); |
eb3f595d MKL |
2564 | |
2565 | return 0; | |
2566 | } | |
2567 | ||
1dc92851 DB |
2568 | static int btf_var_resolve(struct btf_verifier_env *env, |
2569 | const struct resolve_vertex *v) | |
2570 | { | |
2571 | const struct btf_type *next_type; | |
2572 | const struct btf_type *t = v->t; | |
2573 | u32 next_type_id = t->type; | |
2574 | struct btf *btf = env->btf; | |
1dc92851 DB |
2575 | |
2576 | next_type = btf_type_by_id(btf, next_type_id); | |
2577 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { | |
2578 | btf_verifier_log_type(env, v->t, "Invalid type_id"); | |
2579 | return -EINVAL; | |
2580 | } | |
2581 | ||
2582 | if (!env_type_is_resolve_sink(env, next_type) && | |
2583 | !env_type_is_resolved(env, next_type_id)) | |
2584 | return env_stack_push(env, next_type, next_type_id); | |
2585 | ||
2586 | if (btf_type_is_modifier(next_type)) { | |
2587 | const struct btf_type *resolved_type; | |
2588 | u32 resolved_type_id; | |
2589 | ||
2590 | resolved_type_id = next_type_id; | |
2591 | resolved_type = btf_type_id_resolve(btf, &resolved_type_id); | |
2592 | ||
2593 | if (btf_type_is_ptr(resolved_type) && | |
2594 | !env_type_is_resolve_sink(env, resolved_type) && | |
2595 | !env_type_is_resolved(env, resolved_type_id)) | |
2596 | return env_stack_push(env, resolved_type, | |
2597 | resolved_type_id); | |
2598 | } | |
2599 | ||
2600 | /* We must resolve to something concrete at this point, no | |
2601 | * forward types or similar that would resolve to size of | |
2602 | * zero is allowed. | |
2603 | */ | |
1acc5d5c | 2604 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
1dc92851 DB |
2605 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2606 | return -EINVAL; | |
2607 | } | |
2608 | ||
1acc5d5c | 2609 | env_stack_pop_resolved(env, next_type_id, 0); |
1dc92851 DB |
2610 | |
2611 | return 0; | |
2612 | } | |
2613 | ||
eb3f595d MKL |
2614 | static int btf_ptr_resolve(struct btf_verifier_env *env, |
2615 | const struct resolve_vertex *v) | |
2616 | { | |
2617 | const struct btf_type *next_type; | |
2618 | const struct btf_type *t = v->t; | |
2619 | u32 next_type_id = t->type; | |
2620 | struct btf *btf = env->btf; | |
eb3f595d MKL |
2621 | |
2622 | next_type = btf_type_by_id(btf, next_type_id); | |
1dc92851 | 2623 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
eb3f595d MKL |
2624 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2625 | return -EINVAL; | |
2626 | } | |
2627 | ||
eb3f595d MKL |
2628 | if (!env_type_is_resolve_sink(env, next_type) && |
2629 | !env_type_is_resolved(env, next_type_id)) | |
2630 | return env_stack_push(env, next_type, next_type_id); | |
2631 | ||
2632 | /* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY, | |
2633 | * the modifier may have stopped resolving when it was resolved | |
2634 | * to a ptr (last-resolved-ptr). | |
2635 | * | |
2636 | * We now need to continue from the last-resolved-ptr to | |
2637 | * ensure the last-resolved-ptr will not referring back to | |
c561d110 | 2638 | * the current ptr (t). |
eb3f595d MKL |
2639 | */ |
2640 | if (btf_type_is_modifier(next_type)) { | |
2641 | const struct btf_type *resolved_type; | |
2642 | u32 resolved_type_id; | |
2643 | ||
2644 | resolved_type_id = next_type_id; | |
2645 | resolved_type = btf_type_id_resolve(btf, &resolved_type_id); | |
2646 | ||
2647 | if (btf_type_is_ptr(resolved_type) && | |
2648 | !env_type_is_resolve_sink(env, resolved_type) && | |
2649 | !env_type_is_resolved(env, resolved_type_id)) | |
2650 | return env_stack_push(env, resolved_type, | |
2651 | resolved_type_id); | |
2652 | } | |
2653 | ||
2667a262 MKL |
2654 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
2655 | if (env_type_is_resolved(env, next_type_id)) | |
2656 | next_type = btf_type_id_resolve(btf, &next_type_id); | |
2657 | ||
2658 | if (!btf_type_is_void(next_type) && | |
2659 | !btf_type_is_fwd(next_type) && | |
2660 | !btf_type_is_func_proto(next_type)) { | |
2661 | btf_verifier_log_type(env, v->t, "Invalid type_id"); | |
2662 | return -EINVAL; | |
2663 | } | |
eb3f595d MKL |
2664 | } |
2665 | ||
eb3f595d MKL |
2666 | env_stack_pop_resolved(env, next_type_id, 0); |
2667 | ||
2668 | return 0; | |
2669 | } | |
2670 | ||
31d0bc81 AM |
2671 | static void btf_modifier_show(const struct btf *btf, |
2672 | const struct btf_type *t, | |
2673 | u32 type_id, void *data, | |
2674 | u8 bits_offset, struct btf_show *show) | |
b00b8dae | 2675 | { |
85d33df3 MKL |
2676 | if (btf->resolved_ids) |
2677 | t = btf_type_id_resolve(btf, &type_id); | |
2678 | else | |
2679 | t = btf_type_skip_modifiers(btf, type_id, NULL); | |
b00b8dae | 2680 | |
31d0bc81 | 2681 | btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show); |
b00b8dae MKL |
2682 | } |
2683 | ||
31d0bc81 AM |
2684 | static void btf_var_show(const struct btf *btf, const struct btf_type *t, |
2685 | u32 type_id, void *data, u8 bits_offset, | |
2686 | struct btf_show *show) | |
1dc92851 DB |
2687 | { |
2688 | t = btf_type_id_resolve(btf, &type_id); | |
2689 | ||
31d0bc81 | 2690 | btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show); |
1dc92851 DB |
2691 | } |
2692 | ||
31d0bc81 AM |
2693 | static void btf_ptr_show(const struct btf *btf, const struct btf_type *t, |
2694 | u32 type_id, void *data, u8 bits_offset, | |
2695 | struct btf_show *show) | |
b00b8dae | 2696 | { |
31d0bc81 AM |
2697 | void *safe_data; |
2698 | ||
2699 | safe_data = btf_show_start_type(show, t, type_id, data); | |
2700 | if (!safe_data) | |
2701 | return; | |
2702 | ||
2703 | /* It is a hashed value unless BTF_SHOW_PTR_RAW is specified */ | |
2704 | if (show->flags & BTF_SHOW_PTR_RAW) | |
2705 | btf_show_type_value(show, "0x%px", *(void **)safe_data); | |
2706 | else | |
2707 | btf_show_type_value(show, "0x%p", *(void **)safe_data); | |
2708 | btf_show_end_type(show); | |
b00b8dae MKL |
2709 | } |
2710 | ||
69b693f0 MKL |
2711 | static void btf_ref_type_log(struct btf_verifier_env *env, |
2712 | const struct btf_type *t) | |
2713 | { | |
2714 | btf_verifier_log(env, "type_id=%u", t->type); | |
2715 | } | |
2716 | ||
2717 | static struct btf_kind_operations modifier_ops = { | |
2718 | .check_meta = btf_ref_type_check_meta, | |
eb3f595d | 2719 | .resolve = btf_modifier_resolve, |
179cde8c | 2720 | .check_member = btf_modifier_check_member, |
9d5f9f70 | 2721 | .check_kflag_member = btf_modifier_check_kflag_member, |
69b693f0 | 2722 | .log_details = btf_ref_type_log, |
31d0bc81 | 2723 | .show = btf_modifier_show, |
69b693f0 MKL |
2724 | }; |
2725 | ||
2726 | static struct btf_kind_operations ptr_ops = { | |
2727 | .check_meta = btf_ref_type_check_meta, | |
eb3f595d | 2728 | .resolve = btf_ptr_resolve, |
179cde8c | 2729 | .check_member = btf_ptr_check_member, |
9d5f9f70 | 2730 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 2731 | .log_details = btf_ref_type_log, |
31d0bc81 | 2732 | .show = btf_ptr_show, |
69b693f0 MKL |
2733 | }; |
2734 | ||
8175383f MKL |
2735 | static s32 btf_fwd_check_meta(struct btf_verifier_env *env, |
2736 | const struct btf_type *t, | |
2737 | u32 meta_left) | |
2738 | { | |
2739 | if (btf_type_vlen(t)) { | |
2740 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2741 | return -EINVAL; | |
2742 | } | |
2743 | ||
2744 | if (t->type) { | |
2745 | btf_verifier_log_type(env, t, "type != 0"); | |
2746 | return -EINVAL; | |
2747 | } | |
2748 | ||
eb04bbb6 YS |
2749 | /* fwd type must have a valid name */ |
2750 | if (!t->name_off || | |
2751 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
2752 | btf_verifier_log_type(env, t, "Invalid name"); | |
2753 | return -EINVAL; | |
2754 | } | |
2755 | ||
8175383f MKL |
2756 | btf_verifier_log_type(env, t, NULL); |
2757 | ||
2758 | return 0; | |
2759 | } | |
2760 | ||
76c43ae8 YS |
2761 | static void btf_fwd_type_log(struct btf_verifier_env *env, |
2762 | const struct btf_type *t) | |
2763 | { | |
2764 | btf_verifier_log(env, "%s", btf_type_kflag(t) ? "union" : "struct"); | |
2765 | } | |
2766 | ||
69b693f0 | 2767 | static struct btf_kind_operations fwd_ops = { |
8175383f | 2768 | .check_meta = btf_fwd_check_meta, |
eb3f595d | 2769 | .resolve = btf_df_resolve, |
179cde8c | 2770 | .check_member = btf_df_check_member, |
9d5f9f70 | 2771 | .check_kflag_member = btf_df_check_kflag_member, |
76c43ae8 | 2772 | .log_details = btf_fwd_type_log, |
31d0bc81 | 2773 | .show = btf_df_show, |
69b693f0 MKL |
2774 | }; |
2775 | ||
179cde8c MKL |
2776 | static int btf_array_check_member(struct btf_verifier_env *env, |
2777 | const struct btf_type *struct_type, | |
2778 | const struct btf_member *member, | |
2779 | const struct btf_type *member_type) | |
2780 | { | |
2781 | u32 struct_bits_off = member->offset; | |
2782 | u32 struct_size, bytes_offset; | |
2783 | u32 array_type_id, array_size; | |
2784 | struct btf *btf = env->btf; | |
2785 | ||
2786 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2787 | btf_verifier_log_member(env, struct_type, member, | |
2788 | "Member is not byte aligned"); | |
2789 | return -EINVAL; | |
2790 | } | |
2791 | ||
2792 | array_type_id = member->type; | |
2793 | btf_type_id_size(btf, &array_type_id, &array_size); | |
2794 | struct_size = struct_type->size; | |
2795 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2796 | if (struct_size - bytes_offset < array_size) { | |
2797 | btf_verifier_log_member(env, struct_type, member, | |
2798 | "Member exceeds struct_size"); | |
2799 | return -EINVAL; | |
2800 | } | |
2801 | ||
2802 | return 0; | |
2803 | } | |
2804 | ||
69b693f0 MKL |
2805 | static s32 btf_array_check_meta(struct btf_verifier_env *env, |
2806 | const struct btf_type *t, | |
2807 | u32 meta_left) | |
2808 | { | |
2809 | const struct btf_array *array = btf_type_array(t); | |
2810 | u32 meta_needed = sizeof(*array); | |
2811 | ||
2812 | if (meta_left < meta_needed) { | |
2813 | btf_verifier_log_basic(env, t, | |
2814 | "meta_left:%u meta_needed:%u", | |
2815 | meta_left, meta_needed); | |
2816 | return -EINVAL; | |
2817 | } | |
2818 | ||
eb04bbb6 YS |
2819 | /* array type should not have a name */ |
2820 | if (t->name_off) { | |
2821 | btf_verifier_log_type(env, t, "Invalid name"); | |
2822 | return -EINVAL; | |
2823 | } | |
2824 | ||
69b693f0 MKL |
2825 | if (btf_type_vlen(t)) { |
2826 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2827 | return -EINVAL; | |
2828 | } | |
2829 | ||
9d5f9f70 YS |
2830 | if (btf_type_kflag(t)) { |
2831 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2832 | return -EINVAL; | |
2833 | } | |
2834 | ||
b9308ae6 MKL |
2835 | if (t->size) { |
2836 | btf_verifier_log_type(env, t, "size != 0"); | |
2837 | return -EINVAL; | |
2838 | } | |
2839 | ||
4ef5f574 MKL |
2840 | /* Array elem type and index type cannot be in type void, |
2841 | * so !array->type and !array->index_type are not allowed. | |
69b693f0 | 2842 | */ |
aea2f7b8 | 2843 | if (!array->type || !BTF_TYPE_ID_VALID(array->type)) { |
4ef5f574 MKL |
2844 | btf_verifier_log_type(env, t, "Invalid elem"); |
2845 | return -EINVAL; | |
2846 | } | |
2847 | ||
aea2f7b8 | 2848 | if (!array->index_type || !BTF_TYPE_ID_VALID(array->index_type)) { |
4ef5f574 | 2849 | btf_verifier_log_type(env, t, "Invalid index"); |
69b693f0 MKL |
2850 | return -EINVAL; |
2851 | } | |
2852 | ||
2853 | btf_verifier_log_type(env, t, NULL); | |
2854 | ||
2855 | return meta_needed; | |
2856 | } | |
2857 | ||
eb3f595d MKL |
2858 | static int btf_array_resolve(struct btf_verifier_env *env, |
2859 | const struct resolve_vertex *v) | |
2860 | { | |
2861 | const struct btf_array *array = btf_type_array(v->t); | |
4ef5f574 MKL |
2862 | const struct btf_type *elem_type, *index_type; |
2863 | u32 elem_type_id, index_type_id; | |
eb3f595d MKL |
2864 | struct btf *btf = env->btf; |
2865 | u32 elem_size; | |
2866 | ||
4ef5f574 MKL |
2867 | /* Check array->index_type */ |
2868 | index_type_id = array->index_type; | |
2869 | index_type = btf_type_by_id(btf, index_type_id); | |
e4f07120 SF |
2870 | if (btf_type_nosize_or_null(index_type) || |
2871 | btf_type_is_resolve_source_only(index_type)) { | |
4ef5f574 MKL |
2872 | btf_verifier_log_type(env, v->t, "Invalid index"); |
2873 | return -EINVAL; | |
2874 | } | |
2875 | ||
2876 | if (!env_type_is_resolve_sink(env, index_type) && | |
2877 | !env_type_is_resolved(env, index_type_id)) | |
2878 | return env_stack_push(env, index_type, index_type_id); | |
2879 | ||
2880 | index_type = btf_type_id_size(btf, &index_type_id, NULL); | |
2881 | if (!index_type || !btf_type_is_int(index_type) || | |
2882 | !btf_type_int_is_regular(index_type)) { | |
2883 | btf_verifier_log_type(env, v->t, "Invalid index"); | |
2884 | return -EINVAL; | |
2885 | } | |
2886 | ||
2887 | /* Check array->type */ | |
2888 | elem_type_id = array->type; | |
eb3f595d | 2889 | elem_type = btf_type_by_id(btf, elem_type_id); |
e4f07120 SF |
2890 | if (btf_type_nosize_or_null(elem_type) || |
2891 | btf_type_is_resolve_source_only(elem_type)) { | |
eb3f595d MKL |
2892 | btf_verifier_log_type(env, v->t, |
2893 | "Invalid elem"); | |
2894 | return -EINVAL; | |
2895 | } | |
2896 | ||
2897 | if (!env_type_is_resolve_sink(env, elem_type) && | |
2898 | !env_type_is_resolved(env, elem_type_id)) | |
2899 | return env_stack_push(env, elem_type, elem_type_id); | |
2900 | ||
2901 | elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); | |
2902 | if (!elem_type) { | |
2903 | btf_verifier_log_type(env, v->t, "Invalid elem"); | |
2904 | return -EINVAL; | |
2905 | } | |
2906 | ||
4ef5f574 MKL |
2907 | if (btf_type_is_int(elem_type) && !btf_type_int_is_regular(elem_type)) { |
2908 | btf_verifier_log_type(env, v->t, "Invalid array of int"); | |
2909 | return -EINVAL; | |
eb3f595d MKL |
2910 | } |
2911 | ||
2912 | if (array->nelems && elem_size > U32_MAX / array->nelems) { | |
2913 | btf_verifier_log_type(env, v->t, | |
2914 | "Array size overflows U32_MAX"); | |
2915 | return -EINVAL; | |
2916 | } | |
2917 | ||
2918 | env_stack_pop_resolved(env, elem_type_id, elem_size * array->nelems); | |
2919 | ||
2920 | return 0; | |
2921 | } | |
2922 | ||
69b693f0 MKL |
2923 | static void btf_array_log(struct btf_verifier_env *env, |
2924 | const struct btf_type *t) | |
2925 | { | |
2926 | const struct btf_array *array = btf_type_array(t); | |
2927 | ||
2928 | btf_verifier_log(env, "type_id=%u index_type_id=%u nr_elems=%u", | |
2929 | array->type, array->index_type, array->nelems); | |
2930 | } | |
2931 | ||
31d0bc81 AM |
2932 | static void __btf_array_show(const struct btf *btf, const struct btf_type *t, |
2933 | u32 type_id, void *data, u8 bits_offset, | |
2934 | struct btf_show *show) | |
b00b8dae MKL |
2935 | { |
2936 | const struct btf_array *array = btf_type_array(t); | |
2937 | const struct btf_kind_operations *elem_ops; | |
2938 | const struct btf_type *elem_type; | |
31d0bc81 AM |
2939 | u32 i, elem_size = 0, elem_type_id; |
2940 | u16 encoding = 0; | |
b00b8dae MKL |
2941 | |
2942 | elem_type_id = array->type; | |
31d0bc81 AM |
2943 | elem_type = btf_type_skip_modifiers(btf, elem_type_id, NULL); |
2944 | if (elem_type && btf_type_has_size(elem_type)) | |
2945 | elem_size = elem_type->size; | |
2946 | ||
2947 | if (elem_type && btf_type_is_int(elem_type)) { | |
2948 | u32 int_type = btf_type_int(elem_type); | |
2949 | ||
2950 | encoding = BTF_INT_ENCODING(int_type); | |
2951 | ||
2952 | /* | |
2953 | * BTF_INT_CHAR encoding never seems to be set for | |
2954 | * char arrays, so if size is 1 and element is | |
2955 | * printable as a char, we'll do that. | |
2956 | */ | |
2957 | if (elem_size == 1) | |
2958 | encoding = BTF_INT_CHAR; | |
2959 | } | |
2960 | ||
2961 | if (!btf_show_start_array_type(show, t, type_id, encoding, data)) | |
2962 | return; | |
2963 | ||
2964 | if (!elem_type) | |
2965 | goto out; | |
b00b8dae | 2966 | elem_ops = btf_type_ops(elem_type); |
31d0bc81 | 2967 | |
b00b8dae | 2968 | for (i = 0; i < array->nelems; i++) { |
b00b8dae | 2969 | |
31d0bc81 AM |
2970 | btf_show_start_array_member(show); |
2971 | ||
2972 | elem_ops->show(btf, elem_type, elem_type_id, data, | |
2973 | bits_offset, show); | |
b00b8dae | 2974 | data += elem_size; |
31d0bc81 AM |
2975 | |
2976 | btf_show_end_array_member(show); | |
2977 | ||
2978 | if (show->state.array_terminated) | |
2979 | break; | |
b00b8dae | 2980 | } |
31d0bc81 AM |
2981 | out: |
2982 | btf_show_end_array_type(show); | |
2983 | } | |
2984 | ||
2985 | static void btf_array_show(const struct btf *btf, const struct btf_type *t, | |
2986 | u32 type_id, void *data, u8 bits_offset, | |
2987 | struct btf_show *show) | |
2988 | { | |
2989 | const struct btf_member *m = show->state.member; | |
2990 | ||
2991 | /* | |
2992 | * First check if any members would be shown (are non-zero). | |
2993 | * See comments above "struct btf_show" definition for more | |
2994 | * details on how this works at a high-level. | |
2995 | */ | |
2996 | if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) { | |
2997 | if (!show->state.depth_check) { | |
2998 | show->state.depth_check = show->state.depth + 1; | |
2999 | show->state.depth_to_show = 0; | |
3000 | } | |
3001 | __btf_array_show(btf, t, type_id, data, bits_offset, show); | |
3002 | show->state.member = m; | |
3003 | ||
3004 | if (show->state.depth_check != show->state.depth + 1) | |
3005 | return; | |
3006 | show->state.depth_check = 0; | |
3007 | ||
3008 | if (show->state.depth_to_show <= show->state.depth) | |
3009 | return; | |
3010 | /* | |
3011 | * Reaching here indicates we have recursed and found | |
3012 | * non-zero array member(s). | |
3013 | */ | |
3014 | } | |
3015 | __btf_array_show(btf, t, type_id, data, bits_offset, show); | |
b00b8dae MKL |
3016 | } |
3017 | ||
69b693f0 MKL |
3018 | static struct btf_kind_operations array_ops = { |
3019 | .check_meta = btf_array_check_meta, | |
eb3f595d | 3020 | .resolve = btf_array_resolve, |
179cde8c | 3021 | .check_member = btf_array_check_member, |
9d5f9f70 | 3022 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 3023 | .log_details = btf_array_log, |
31d0bc81 | 3024 | .show = btf_array_show, |
69b693f0 MKL |
3025 | }; |
3026 | ||
179cde8c MKL |
3027 | static int btf_struct_check_member(struct btf_verifier_env *env, |
3028 | const struct btf_type *struct_type, | |
3029 | const struct btf_member *member, | |
3030 | const struct btf_type *member_type) | |
3031 | { | |
3032 | u32 struct_bits_off = member->offset; | |
3033 | u32 struct_size, bytes_offset; | |
3034 | ||
3035 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
3036 | btf_verifier_log_member(env, struct_type, member, | |
3037 | "Member is not byte aligned"); | |
3038 | return -EINVAL; | |
3039 | } | |
3040 | ||
3041 | struct_size = struct_type->size; | |
3042 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
3043 | if (struct_size - bytes_offset < member_type->size) { | |
3044 | btf_verifier_log_member(env, struct_type, member, | |
3045 | "Member exceeds struct_size"); | |
3046 | return -EINVAL; | |
3047 | } | |
3048 | ||
3049 | return 0; | |
3050 | } | |
3051 | ||
69b693f0 MKL |
3052 | static s32 btf_struct_check_meta(struct btf_verifier_env *env, |
3053 | const struct btf_type *t, | |
3054 | u32 meta_left) | |
3055 | { | |
3056 | bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION; | |
3057 | const struct btf_member *member; | |
6283fa38 | 3058 | u32 meta_needed, last_offset; |
69b693f0 MKL |
3059 | struct btf *btf = env->btf; |
3060 | u32 struct_size = t->size; | |
9d5f9f70 | 3061 | u32 offset; |
69b693f0 MKL |
3062 | u16 i; |
3063 | ||
3064 | meta_needed = btf_type_vlen(t) * sizeof(*member); | |
3065 | if (meta_left < meta_needed) { | |
3066 | btf_verifier_log_basic(env, t, | |
3067 | "meta_left:%u meta_needed:%u", | |
3068 | meta_left, meta_needed); | |
3069 | return -EINVAL; | |
3070 | } | |
3071 | ||
eb04bbb6 YS |
3072 | /* struct type either no name or a valid one */ |
3073 | if (t->name_off && | |
3074 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
3075 | btf_verifier_log_type(env, t, "Invalid name"); | |
3076 | return -EINVAL; | |
3077 | } | |
3078 | ||
69b693f0 MKL |
3079 | btf_verifier_log_type(env, t, NULL); |
3080 | ||
6283fa38 | 3081 | last_offset = 0; |
69b693f0 | 3082 | for_each_member(i, t, member) { |
fbcf93eb | 3083 | if (!btf_name_offset_valid(btf, member->name_off)) { |
69b693f0 MKL |
3084 | btf_verifier_log_member(env, t, member, |
3085 | "Invalid member name_offset:%u", | |
fbcf93eb | 3086 | member->name_off); |
69b693f0 MKL |
3087 | return -EINVAL; |
3088 | } | |
3089 | ||
eb04bbb6 YS |
3090 | /* struct member either no name or a valid one */ |
3091 | if (member->name_off && | |
3092 | !btf_name_valid_identifier(btf, member->name_off)) { | |
3093 | btf_verifier_log_member(env, t, member, "Invalid name"); | |
3094 | return -EINVAL; | |
3095 | } | |
69b693f0 | 3096 | /* A member cannot be in type void */ |
aea2f7b8 | 3097 | if (!member->type || !BTF_TYPE_ID_VALID(member->type)) { |
69b693f0 MKL |
3098 | btf_verifier_log_member(env, t, member, |
3099 | "Invalid type_id"); | |
3100 | return -EINVAL; | |
3101 | } | |
3102 | ||
8293eb99 | 3103 | offset = __btf_member_bit_offset(t, member); |
9d5f9f70 | 3104 | if (is_union && offset) { |
69b693f0 MKL |
3105 | btf_verifier_log_member(env, t, member, |
3106 | "Invalid member bits_offset"); | |
3107 | return -EINVAL; | |
3108 | } | |
3109 | ||
6283fa38 MKL |
3110 | /* |
3111 | * ">" instead of ">=" because the last member could be | |
3112 | * "char a[0];" | |
3113 | */ | |
9d5f9f70 | 3114 | if (last_offset > offset) { |
6283fa38 MKL |
3115 | btf_verifier_log_member(env, t, member, |
3116 | "Invalid member bits_offset"); | |
3117 | return -EINVAL; | |
3118 | } | |
3119 | ||
9d5f9f70 | 3120 | if (BITS_ROUNDUP_BYTES(offset) > struct_size) { |
69b693f0 | 3121 | btf_verifier_log_member(env, t, member, |
311fe1a8 | 3122 | "Member bits_offset exceeds its struct size"); |
69b693f0 MKL |
3123 | return -EINVAL; |
3124 | } | |
3125 | ||
3126 | btf_verifier_log_member(env, t, member, NULL); | |
9d5f9f70 | 3127 | last_offset = offset; |
69b693f0 MKL |
3128 | } |
3129 | ||
3130 | return meta_needed; | |
3131 | } | |
3132 | ||
eb3f595d MKL |
3133 | static int btf_struct_resolve(struct btf_verifier_env *env, |
3134 | const struct resolve_vertex *v) | |
3135 | { | |
3136 | const struct btf_member *member; | |
179cde8c | 3137 | int err; |
eb3f595d MKL |
3138 | u16 i; |
3139 | ||
3140 | /* Before continue resolving the next_member, | |
3141 | * ensure the last member is indeed resolved to a | |
3142 | * type with size info. | |
3143 | */ | |
3144 | if (v->next_member) { | |
179cde8c | 3145 | const struct btf_type *last_member_type; |
eb3f595d | 3146 | const struct btf_member *last_member; |
a37a3258 | 3147 | u32 last_member_type_id; |
eb3f595d MKL |
3148 | |
3149 | last_member = btf_type_member(v->t) + v->next_member - 1; | |
3150 | last_member_type_id = last_member->type; | |
3151 | if (WARN_ON_ONCE(!env_type_is_resolved(env, | |
3152 | last_member_type_id))) | |
3153 | return -EINVAL; | |
179cde8c MKL |
3154 | |
3155 | last_member_type = btf_type_by_id(env->btf, | |
3156 | last_member_type_id); | |
9d5f9f70 YS |
3157 | if (btf_type_kflag(v->t)) |
3158 | err = btf_type_ops(last_member_type)->check_kflag_member(env, v->t, | |
3159 | last_member, | |
3160 | last_member_type); | |
3161 | else | |
3162 | err = btf_type_ops(last_member_type)->check_member(env, v->t, | |
3163 | last_member, | |
3164 | last_member_type); | |
179cde8c MKL |
3165 | if (err) |
3166 | return err; | |
eb3f595d MKL |
3167 | } |
3168 | ||
3169 | for_each_member_from(i, v->next_member, v->t, member) { | |
3170 | u32 member_type_id = member->type; | |
3171 | const struct btf_type *member_type = btf_type_by_id(env->btf, | |
3172 | member_type_id); | |
3173 | ||
e4f07120 SF |
3174 | if (btf_type_nosize_or_null(member_type) || |
3175 | btf_type_is_resolve_source_only(member_type)) { | |
eb3f595d MKL |
3176 | btf_verifier_log_member(env, v->t, member, |
3177 | "Invalid member"); | |
3178 | return -EINVAL; | |
3179 | } | |
3180 | ||
3181 | if (!env_type_is_resolve_sink(env, member_type) && | |
3182 | !env_type_is_resolved(env, member_type_id)) { | |
3183 | env_stack_set_next_member(env, i + 1); | |
3184 | return env_stack_push(env, member_type, member_type_id); | |
3185 | } | |
179cde8c | 3186 | |
9d5f9f70 YS |
3187 | if (btf_type_kflag(v->t)) |
3188 | err = btf_type_ops(member_type)->check_kflag_member(env, v->t, | |
3189 | member, | |
3190 | member_type); | |
3191 | else | |
3192 | err = btf_type_ops(member_type)->check_member(env, v->t, | |
3193 | member, | |
3194 | member_type); | |
179cde8c MKL |
3195 | if (err) |
3196 | return err; | |
eb3f595d MKL |
3197 | } |
3198 | ||
3199 | env_stack_pop_resolved(env, 0, 0); | |
3200 | ||
3201 | return 0; | |
3202 | } | |
3203 | ||
69b693f0 MKL |
3204 | static void btf_struct_log(struct btf_verifier_env *env, |
3205 | const struct btf_type *t) | |
3206 | { | |
3207 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
3208 | } | |
3209 | ||
aa3496ac | 3210 | enum btf_field_info_type { |
42ba1308 KKD |
3211 | BTF_FIELD_SPIN_LOCK, |
3212 | BTF_FIELD_TIMER, | |
61df10c7 KKD |
3213 | BTF_FIELD_KPTR, |
3214 | }; | |
3215 | ||
3216 | enum { | |
3217 | BTF_FIELD_IGNORE = 0, | |
3218 | BTF_FIELD_FOUND = 1, | |
42ba1308 KKD |
3219 | }; |
3220 | ||
3221 | struct btf_field_info { | |
aa3496ac | 3222 | enum btf_field_type type; |
42ba1308 | 3223 | u32 off; |
f0c5941f KKD |
3224 | union { |
3225 | struct { | |
3226 | u32 type_id; | |
3227 | } kptr; | |
3228 | struct { | |
3229 | const char *node_name; | |
3230 | u32 value_btf_id; | |
3231 | } list_head; | |
3232 | }; | |
42ba1308 KKD |
3233 | }; |
3234 | ||
3235 | static int btf_find_struct(const struct btf *btf, const struct btf_type *t, | |
db559117 KKD |
3236 | u32 off, int sz, enum btf_field_type field_type, |
3237 | struct btf_field_info *info) | |
42ba1308 KKD |
3238 | { |
3239 | if (!__btf_type_is_struct(t)) | |
61df10c7 | 3240 | return BTF_FIELD_IGNORE; |
42ba1308 | 3241 | if (t->size != sz) |
61df10c7 | 3242 | return BTF_FIELD_IGNORE; |
db559117 | 3243 | info->type = field_type; |
42ba1308 | 3244 | info->off = off; |
61df10c7 KKD |
3245 | return BTF_FIELD_FOUND; |
3246 | } | |
3247 | ||
3248 | static int btf_find_kptr(const struct btf *btf, const struct btf_type *t, | |
3249 | u32 off, int sz, struct btf_field_info *info) | |
3250 | { | |
aa3496ac | 3251 | enum btf_field_type type; |
61df10c7 KKD |
3252 | u32 res_id; |
3253 | ||
23da464d KKD |
3254 | /* Permit modifiers on the pointer itself */ |
3255 | if (btf_type_is_volatile(t)) | |
3256 | t = btf_type_by_id(btf, t->type); | |
61df10c7 KKD |
3257 | /* For PTR, sz is always == 8 */ |
3258 | if (!btf_type_is_ptr(t)) | |
3259 | return BTF_FIELD_IGNORE; | |
3260 | t = btf_type_by_id(btf, t->type); | |
3261 | ||
3262 | if (!btf_type_is_type_tag(t)) | |
3263 | return BTF_FIELD_IGNORE; | |
3264 | /* Reject extra tags */ | |
3265 | if (btf_type_is_type_tag(btf_type_by_id(btf, t->type))) | |
3266 | return -EINVAL; | |
c0a5a21c KKD |
3267 | if (!strcmp("kptr", __btf_name_by_offset(btf, t->name_off))) |
3268 | type = BPF_KPTR_UNREF; | |
3269 | else if (!strcmp("kptr_ref", __btf_name_by_offset(btf, t->name_off))) | |
3270 | type = BPF_KPTR_REF; | |
3271 | else | |
61df10c7 KKD |
3272 | return -EINVAL; |
3273 | ||
3274 | /* Get the base type */ | |
3275 | t = btf_type_skip_modifiers(btf, t->type, &res_id); | |
3276 | /* Only pointer to struct is allowed */ | |
3277 | if (!__btf_type_is_struct(t)) | |
3278 | return -EINVAL; | |
3279 | ||
c0a5a21c | 3280 | info->type = type; |
db559117 KKD |
3281 | info->off = off; |
3282 | info->kptr.type_id = res_id; | |
61df10c7 | 3283 | return BTF_FIELD_FOUND; |
42ba1308 KKD |
3284 | } |
3285 | ||
f0c5941f KKD |
3286 | static const char *btf_find_decl_tag_value(const struct btf *btf, |
3287 | const struct btf_type *pt, | |
3288 | int comp_idx, const char *tag_key) | |
3289 | { | |
3290 | int i; | |
3291 | ||
3292 | for (i = 1; i < btf_nr_types(btf); i++) { | |
3293 | const struct btf_type *t = btf_type_by_id(btf, i); | |
3294 | int len = strlen(tag_key); | |
3295 | ||
3296 | if (!btf_type_is_decl_tag(t)) | |
3297 | continue; | |
3298 | if (pt != btf_type_by_id(btf, t->type) || | |
3299 | btf_type_decl_tag(t)->component_idx != comp_idx) | |
3300 | continue; | |
3301 | if (strncmp(__btf_name_by_offset(btf, t->name_off), tag_key, len)) | |
3302 | continue; | |
3303 | return __btf_name_by_offset(btf, t->name_off) + len; | |
3304 | } | |
3305 | return NULL; | |
3306 | } | |
3307 | ||
3308 | static int btf_find_list_head(const struct btf *btf, const struct btf_type *pt, | |
3309 | const struct btf_type *t, int comp_idx, | |
3310 | u32 off, int sz, struct btf_field_info *info) | |
3311 | { | |
3312 | const char *value_type; | |
3313 | const char *list_node; | |
3314 | s32 id; | |
3315 | ||
3316 | if (!__btf_type_is_struct(t)) | |
3317 | return BTF_FIELD_IGNORE; | |
3318 | if (t->size != sz) | |
3319 | return BTF_FIELD_IGNORE; | |
3320 | value_type = btf_find_decl_tag_value(btf, pt, comp_idx, "contains:"); | |
3321 | if (!value_type) | |
3322 | return -EINVAL; | |
3323 | list_node = strstr(value_type, ":"); | |
3324 | if (!list_node) | |
3325 | return -EINVAL; | |
3326 | value_type = kstrndup(value_type, list_node - value_type, GFP_KERNEL | __GFP_NOWARN); | |
3327 | if (!value_type) | |
3328 | return -ENOMEM; | |
3329 | id = btf_find_by_name_kind(btf, value_type, BTF_KIND_STRUCT); | |
3330 | kfree(value_type); | |
3331 | if (id < 0) | |
3332 | return id; | |
3333 | list_node++; | |
3334 | if (str_is_empty(list_node)) | |
3335 | return -EINVAL; | |
3336 | info->type = BPF_LIST_HEAD; | |
3337 | info->off = off; | |
3338 | info->list_head.value_btf_id = id; | |
3339 | info->list_head.node_name = list_node; | |
3340 | return BTF_FIELD_FOUND; | |
3341 | } | |
3342 | ||
db559117 KKD |
3343 | static int btf_get_field_type(const char *name, u32 field_mask, u32 *seen_mask, |
3344 | int *align, int *sz) | |
3345 | { | |
3346 | int type = 0; | |
3347 | ||
3348 | if (field_mask & BPF_SPIN_LOCK) { | |
3349 | if (!strcmp(name, "bpf_spin_lock")) { | |
3350 | if (*seen_mask & BPF_SPIN_LOCK) | |
3351 | return -E2BIG; | |
3352 | *seen_mask |= BPF_SPIN_LOCK; | |
3353 | type = BPF_SPIN_LOCK; | |
3354 | goto end; | |
3355 | } | |
3356 | } | |
3357 | if (field_mask & BPF_TIMER) { | |
3358 | if (!strcmp(name, "bpf_timer")) { | |
3359 | if (*seen_mask & BPF_TIMER) | |
3360 | return -E2BIG; | |
3361 | *seen_mask |= BPF_TIMER; | |
3362 | type = BPF_TIMER; | |
3363 | goto end; | |
3364 | } | |
3365 | } | |
f0c5941f KKD |
3366 | if (field_mask & BPF_LIST_HEAD) { |
3367 | if (!strcmp(name, "bpf_list_head")) { | |
3368 | type = BPF_LIST_HEAD; | |
3369 | goto end; | |
3370 | } | |
3371 | } | |
8ffa5cc1 KKD |
3372 | if (field_mask & BPF_LIST_NODE) { |
3373 | if (!strcmp(name, "bpf_list_node")) { | |
3374 | type = BPF_LIST_NODE; | |
3375 | goto end; | |
3376 | } | |
3377 | } | |
db559117 KKD |
3378 | /* Only return BPF_KPTR when all other types with matchable names fail */ |
3379 | if (field_mask & BPF_KPTR) { | |
3380 | type = BPF_KPTR_REF; | |
3381 | goto end; | |
3382 | } | |
3383 | return 0; | |
3384 | end: | |
3385 | *sz = btf_field_type_size(type); | |
3386 | *align = btf_field_type_align(type); | |
3387 | return type; | |
3388 | } | |
3389 | ||
3390 | static int btf_find_struct_field(const struct btf *btf, | |
3391 | const struct btf_type *t, u32 field_mask, | |
61df10c7 | 3392 | struct btf_field_info *info, int info_cnt) |
d83525ca | 3393 | { |
db559117 | 3394 | int ret, idx = 0, align, sz, field_type; |
d83525ca | 3395 | const struct btf_member *member; |
61df10c7 | 3396 | struct btf_field_info tmp; |
db559117 | 3397 | u32 i, off, seen_mask = 0; |
d83525ca | 3398 | |
d83525ca AS |
3399 | for_each_member(i, t, member) { |
3400 | const struct btf_type *member_type = btf_type_by_id(btf, | |
3401 | member->type); | |
42ba1308 | 3402 | |
db559117 KKD |
3403 | field_type = btf_get_field_type(__btf_name_by_offset(btf, member_type->name_off), |
3404 | field_mask, &seen_mask, &align, &sz); | |
3405 | if (field_type == 0) | |
d83525ca | 3406 | continue; |
db559117 KKD |
3407 | if (field_type < 0) |
3408 | return field_type; | |
42ba1308 | 3409 | |
8293eb99 | 3410 | off = __btf_member_bit_offset(t, member); |
d83525ca AS |
3411 | if (off % 8) |
3412 | /* valid C code cannot generate such BTF */ | |
3413 | return -EINVAL; | |
3414 | off /= 8; | |
68134668 | 3415 | if (off % align) |
db559117 | 3416 | continue; |
42ba1308 KKD |
3417 | |
3418 | switch (field_type) { | |
db559117 KKD |
3419 | case BPF_SPIN_LOCK: |
3420 | case BPF_TIMER: | |
8ffa5cc1 | 3421 | case BPF_LIST_NODE: |
db559117 | 3422 | ret = btf_find_struct(btf, member_type, off, sz, field_type, |
61df10c7 KKD |
3423 | idx < info_cnt ? &info[idx] : &tmp); |
3424 | if (ret < 0) | |
3425 | return ret; | |
3426 | break; | |
db559117 KKD |
3427 | case BPF_KPTR_UNREF: |
3428 | case BPF_KPTR_REF: | |
61df10c7 KKD |
3429 | ret = btf_find_kptr(btf, member_type, off, sz, |
3430 | idx < info_cnt ? &info[idx] : &tmp); | |
3431 | if (ret < 0) | |
3432 | return ret; | |
3433 | break; | |
f0c5941f KKD |
3434 | case BPF_LIST_HEAD: |
3435 | ret = btf_find_list_head(btf, t, member_type, i, off, sz, | |
3436 | idx < info_cnt ? &info[idx] : &tmp); | |
3437 | if (ret < 0) | |
3438 | return ret; | |
3439 | break; | |
42ba1308 KKD |
3440 | default: |
3441 | return -EFAULT; | |
3442 | } | |
61df10c7 KKD |
3443 | |
3444 | if (ret == BTF_FIELD_IGNORE) | |
3445 | continue; | |
3446 | if (idx >= info_cnt) | |
3447 | return -E2BIG; | |
3448 | ++idx; | |
68134668 | 3449 | } |
61df10c7 | 3450 | return idx; |
68134668 AS |
3451 | } |
3452 | ||
3453 | static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t, | |
db559117 KKD |
3454 | u32 field_mask, struct btf_field_info *info, |
3455 | int info_cnt) | |
68134668 | 3456 | { |
db559117 | 3457 | int ret, idx = 0, align, sz, field_type; |
68134668 | 3458 | const struct btf_var_secinfo *vsi; |
61df10c7 | 3459 | struct btf_field_info tmp; |
db559117 | 3460 | u32 i, off, seen_mask = 0; |
68134668 AS |
3461 | |
3462 | for_each_vsi(i, t, vsi) { | |
3463 | const struct btf_type *var = btf_type_by_id(btf, vsi->type); | |
3464 | const struct btf_type *var_type = btf_type_by_id(btf, var->type); | |
3465 | ||
db559117 KKD |
3466 | field_type = btf_get_field_type(__btf_name_by_offset(btf, var_type->name_off), |
3467 | field_mask, &seen_mask, &align, &sz); | |
3468 | if (field_type == 0) | |
68134668 | 3469 | continue; |
db559117 KKD |
3470 | if (field_type < 0) |
3471 | return field_type; | |
3472 | ||
3473 | off = vsi->offset; | |
68134668 AS |
3474 | if (vsi->size != sz) |
3475 | continue; | |
68134668 | 3476 | if (off % align) |
db559117 | 3477 | continue; |
42ba1308 KKD |
3478 | |
3479 | switch (field_type) { | |
db559117 KKD |
3480 | case BPF_SPIN_LOCK: |
3481 | case BPF_TIMER: | |
8ffa5cc1 | 3482 | case BPF_LIST_NODE: |
db559117 | 3483 | ret = btf_find_struct(btf, var_type, off, sz, field_type, |
61df10c7 KKD |
3484 | idx < info_cnt ? &info[idx] : &tmp); |
3485 | if (ret < 0) | |
3486 | return ret; | |
3487 | break; | |
db559117 KKD |
3488 | case BPF_KPTR_UNREF: |
3489 | case BPF_KPTR_REF: | |
61df10c7 KKD |
3490 | ret = btf_find_kptr(btf, var_type, off, sz, |
3491 | idx < info_cnt ? &info[idx] : &tmp); | |
3492 | if (ret < 0) | |
3493 | return ret; | |
3494 | break; | |
f0c5941f KKD |
3495 | case BPF_LIST_HEAD: |
3496 | ret = btf_find_list_head(btf, var, var_type, -1, off, sz, | |
3497 | idx < info_cnt ? &info[idx] : &tmp); | |
3498 | if (ret < 0) | |
3499 | return ret; | |
3500 | break; | |
42ba1308 KKD |
3501 | default: |
3502 | return -EFAULT; | |
3503 | } | |
61df10c7 KKD |
3504 | |
3505 | if (ret == BTF_FIELD_IGNORE) | |
3506 | continue; | |
3507 | if (idx >= info_cnt) | |
3508 | return -E2BIG; | |
3509 | ++idx; | |
d83525ca | 3510 | } |
61df10c7 | 3511 | return idx; |
d83525ca AS |
3512 | } |
3513 | ||
68134668 | 3514 | static int btf_find_field(const struct btf *btf, const struct btf_type *t, |
db559117 KKD |
3515 | u32 field_mask, struct btf_field_info *info, |
3516 | int info_cnt) | |
68134668 | 3517 | { |
68134668 | 3518 | if (__btf_type_is_struct(t)) |
db559117 | 3519 | return btf_find_struct_field(btf, t, field_mask, info, info_cnt); |
68134668 | 3520 | else if (btf_type_is_datasec(t)) |
db559117 | 3521 | return btf_find_datasec_var(btf, t, field_mask, info, info_cnt); |
68134668 AS |
3522 | return -EINVAL; |
3523 | } | |
3524 | ||
db559117 KKD |
3525 | static int btf_parse_kptr(const struct btf *btf, struct btf_field *field, |
3526 | struct btf_field_info *info) | |
68134668 | 3527 | { |
db559117 KKD |
3528 | struct module *mod = NULL; |
3529 | const struct btf_type *t; | |
3530 | struct btf *kernel_btf; | |
42ba1308 | 3531 | int ret; |
db559117 | 3532 | s32 id; |
42ba1308 | 3533 | |
db559117 KKD |
3534 | /* Find type in map BTF, and use it to look up the matching type |
3535 | * in vmlinux or module BTFs, by name and kind. | |
3536 | */ | |
3537 | t = btf_type_by_id(btf, info->kptr.type_id); | |
3538 | id = bpf_find_btf_id(__btf_name_by_offset(btf, t->name_off), BTF_INFO_KIND(t->info), | |
3539 | &kernel_btf); | |
3540 | if (id < 0) | |
3541 | return id; | |
3542 | ||
3543 | /* Find and stash the function pointer for the destruction function that | |
3544 | * needs to be eventually invoked from the map free path. | |
3545 | */ | |
3546 | if (info->type == BPF_KPTR_REF) { | |
3547 | const struct btf_type *dtor_func; | |
3548 | const char *dtor_func_name; | |
3549 | unsigned long addr; | |
3550 | s32 dtor_btf_id; | |
3551 | ||
3552 | /* This call also serves as a whitelist of allowed objects that | |
3553 | * can be used as a referenced pointer and be stored in a map at | |
3554 | * the same time. | |
3555 | */ | |
3556 | dtor_btf_id = btf_find_dtor_kfunc(kernel_btf, id); | |
3557 | if (dtor_btf_id < 0) { | |
3558 | ret = dtor_btf_id; | |
3559 | goto end_btf; | |
3560 | } | |
68134668 | 3561 | |
db559117 KKD |
3562 | dtor_func = btf_type_by_id(kernel_btf, dtor_btf_id); |
3563 | if (!dtor_func) { | |
3564 | ret = -ENOENT; | |
3565 | goto end_btf; | |
3566 | } | |
42ba1308 | 3567 | |
db559117 KKD |
3568 | if (btf_is_module(kernel_btf)) { |
3569 | mod = btf_try_get_module(kernel_btf); | |
3570 | if (!mod) { | |
3571 | ret = -ENXIO; | |
3572 | goto end_btf; | |
3573 | } | |
3574 | } | |
3575 | ||
3576 | /* We already verified dtor_func to be btf_type_is_func | |
3577 | * in register_btf_id_dtor_kfuncs. | |
3578 | */ | |
3579 | dtor_func_name = __btf_name_by_offset(kernel_btf, dtor_func->name_off); | |
3580 | addr = kallsyms_lookup_name(dtor_func_name); | |
3581 | if (!addr) { | |
3582 | ret = -EINVAL; | |
3583 | goto end_mod; | |
3584 | } | |
3585 | field->kptr.dtor = (void *)addr; | |
3586 | } | |
3587 | ||
3588 | field->kptr.btf_id = id; | |
3589 | field->kptr.btf = kernel_btf; | |
3590 | field->kptr.module = mod; | |
3591 | return 0; | |
3592 | end_mod: | |
3593 | module_put(mod); | |
3594 | end_btf: | |
3595 | btf_put(kernel_btf); | |
3596 | return ret; | |
68134668 AS |
3597 | } |
3598 | ||
f0c5941f KKD |
3599 | static int btf_parse_list_head(const struct btf *btf, struct btf_field *field, |
3600 | struct btf_field_info *info) | |
3601 | { | |
3602 | const struct btf_type *t, *n = NULL; | |
3603 | const struct btf_member *member; | |
3604 | u32 offset; | |
3605 | int i; | |
3606 | ||
3607 | t = btf_type_by_id(btf, info->list_head.value_btf_id); | |
3608 | /* We've already checked that value_btf_id is a struct type. We | |
3609 | * just need to figure out the offset of the list_node, and | |
3610 | * verify its type. | |
3611 | */ | |
3612 | for_each_member(i, t, member) { | |
3613 | if (strcmp(info->list_head.node_name, __btf_name_by_offset(btf, member->name_off))) | |
3614 | continue; | |
3615 | /* Invalid BTF, two members with same name */ | |
3616 | if (n) | |
3617 | return -EINVAL; | |
3618 | n = btf_type_by_id(btf, member->type); | |
3619 | if (!__btf_type_is_struct(n)) | |
3620 | return -EINVAL; | |
3621 | if (strcmp("bpf_list_node", __btf_name_by_offset(btf, n->name_off))) | |
3622 | return -EINVAL; | |
3623 | offset = __btf_member_bit_offset(n, member); | |
3624 | if (offset % 8) | |
3625 | return -EINVAL; | |
3626 | offset /= 8; | |
3627 | if (offset % __alignof__(struct bpf_list_node)) | |
3628 | return -EINVAL; | |
3629 | ||
3630 | field->list_head.btf = (struct btf *)btf; | |
3631 | field->list_head.value_btf_id = info->list_head.value_btf_id; | |
3632 | field->list_head.node_offset = offset; | |
3633 | } | |
3634 | if (!n) | |
3635 | return -ENOENT; | |
3636 | return 0; | |
3637 | } | |
3638 | ||
db559117 KKD |
3639 | struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t, |
3640 | u32 field_mask, u32 value_size) | |
61df10c7 | 3641 | { |
aa3496ac | 3642 | struct btf_field_info info_arr[BTF_FIELDS_MAX]; |
aa3496ac | 3643 | struct btf_record *rec; |
f0c5941f | 3644 | u32 next_off = 0; |
aa3496ac | 3645 | int ret, i, cnt; |
61df10c7 | 3646 | |
db559117 | 3647 | ret = btf_find_field(btf, t, field_mask, info_arr, ARRAY_SIZE(info_arr)); |
61df10c7 KKD |
3648 | if (ret < 0) |
3649 | return ERR_PTR(ret); | |
3650 | if (!ret) | |
3651 | return NULL; | |
3652 | ||
aa3496ac | 3653 | cnt = ret; |
c22dfdd2 KKD |
3654 | /* This needs to be kzalloc to zero out padding and unused fields, see |
3655 | * comment in btf_record_equal. | |
3656 | */ | |
aa3496ac KKD |
3657 | rec = kzalloc(offsetof(struct btf_record, fields[cnt]), GFP_KERNEL | __GFP_NOWARN); |
3658 | if (!rec) | |
61df10c7 | 3659 | return ERR_PTR(-ENOMEM); |
61df10c7 | 3660 | |
db559117 KKD |
3661 | rec->spin_lock_off = -EINVAL; |
3662 | rec->timer_off = -EINVAL; | |
3663 | for (i = 0; i < cnt; i++) { | |
3664 | if (info_arr[i].off + btf_field_type_size(info_arr[i].type) > value_size) { | |
3665 | WARN_ONCE(1, "verifier bug off %d size %d", info_arr[i].off, value_size); | |
3666 | ret = -EFAULT; | |
61df10c7 KKD |
3667 | goto end; |
3668 | } | |
f0c5941f KKD |
3669 | if (info_arr[i].off < next_off) { |
3670 | ret = -EEXIST; | |
3671 | goto end; | |
3672 | } | |
3673 | next_off = info_arr[i].off + btf_field_type_size(info_arr[i].type); | |
61df10c7 | 3674 | |
aa3496ac KKD |
3675 | rec->field_mask |= info_arr[i].type; |
3676 | rec->fields[i].offset = info_arr[i].off; | |
3677 | rec->fields[i].type = info_arr[i].type; | |
db559117 KKD |
3678 | |
3679 | switch (info_arr[i].type) { | |
3680 | case BPF_SPIN_LOCK: | |
3681 | WARN_ON_ONCE(rec->spin_lock_off >= 0); | |
3682 | /* Cache offset for faster lookup at runtime */ | |
3683 | rec->spin_lock_off = rec->fields[i].offset; | |
3684 | break; | |
3685 | case BPF_TIMER: | |
3686 | WARN_ON_ONCE(rec->timer_off >= 0); | |
3687 | /* Cache offset for faster lookup at runtime */ | |
3688 | rec->timer_off = rec->fields[i].offset; | |
3689 | break; | |
3690 | case BPF_KPTR_UNREF: | |
3691 | case BPF_KPTR_REF: | |
3692 | ret = btf_parse_kptr(btf, &rec->fields[i], &info_arr[i]); | |
3693 | if (ret < 0) | |
3694 | goto end; | |
3695 | break; | |
f0c5941f KKD |
3696 | case BPF_LIST_HEAD: |
3697 | ret = btf_parse_list_head(btf, &rec->fields[i], &info_arr[i]); | |
3698 | if (ret < 0) | |
3699 | goto end; | |
3700 | break; | |
8ffa5cc1 KKD |
3701 | case BPF_LIST_NODE: |
3702 | break; | |
db559117 KKD |
3703 | default: |
3704 | ret = -EFAULT; | |
3705 | goto end; | |
3706 | } | |
aa3496ac | 3707 | rec->cnt++; |
61df10c7 | 3708 | } |
f0c5941f KKD |
3709 | |
3710 | /* bpf_list_head requires bpf_spin_lock */ | |
3711 | if (btf_record_has_field(rec, BPF_LIST_HEAD) && rec->spin_lock_off < 0) { | |
3712 | ret = -EINVAL; | |
3713 | goto end; | |
3714 | } | |
3715 | ||
aa3496ac | 3716 | return rec; |
61df10c7 | 3717 | end: |
aa3496ac | 3718 | btf_record_free(rec); |
61df10c7 KKD |
3719 | return ERR_PTR(ret); |
3720 | } | |
3721 | ||
865ce09a KKD |
3722 | int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec) |
3723 | { | |
3724 | int i; | |
3725 | ||
3726 | /* There are two owning types, kptr_ref and bpf_list_head. The former | |
3727 | * only supports storing kernel types, which can never store references | |
3728 | * to program allocated local types, atleast not yet. Hence we only need | |
3729 | * to ensure that bpf_list_head ownership does not form cycles. | |
3730 | */ | |
3731 | if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & BPF_LIST_HEAD)) | |
3732 | return 0; | |
3733 | for (i = 0; i < rec->cnt; i++) { | |
3734 | struct btf_struct_meta *meta; | |
3735 | u32 btf_id; | |
3736 | ||
3737 | if (!(rec->fields[i].type & BPF_LIST_HEAD)) | |
3738 | continue; | |
3739 | btf_id = rec->fields[i].list_head.value_btf_id; | |
3740 | meta = btf_find_struct_meta(btf, btf_id); | |
3741 | if (!meta) | |
3742 | return -EFAULT; | |
3743 | rec->fields[i].list_head.value_rec = meta->record; | |
3744 | ||
3745 | if (!(rec->field_mask & BPF_LIST_NODE)) | |
3746 | continue; | |
3747 | ||
3748 | /* We need to ensure ownership acyclicity among all types. The | |
3749 | * proper way to do it would be to topologically sort all BTF | |
3750 | * IDs based on the ownership edges, since there can be multiple | |
3751 | * bpf_list_head in a type. Instead, we use the following | |
3752 | * reasoning: | |
3753 | * | |
3754 | * - A type can only be owned by another type in user BTF if it | |
3755 | * has a bpf_list_node. | |
3756 | * - A type can only _own_ another type in user BTF if it has a | |
3757 | * bpf_list_head. | |
3758 | * | |
3759 | * We ensure that if a type has both bpf_list_head and | |
3760 | * bpf_list_node, its element types cannot be owning types. | |
3761 | * | |
3762 | * To ensure acyclicity: | |
3763 | * | |
3764 | * When A only has bpf_list_head, ownership chain can be: | |
3765 | * A -> B -> C | |
3766 | * Where: | |
3767 | * - B has both bpf_list_head and bpf_list_node. | |
3768 | * - C only has bpf_list_node. | |
3769 | * | |
3770 | * When A has both bpf_list_head and bpf_list_node, some other | |
3771 | * type already owns it in the BTF domain, hence it can not own | |
3772 | * another owning type through any of the bpf_list_head edges. | |
3773 | * A -> B | |
3774 | * Where: | |
3775 | * - B only has bpf_list_node. | |
3776 | */ | |
3777 | if (meta->record->field_mask & BPF_LIST_HEAD) | |
3778 | return -ELOOP; | |
3779 | } | |
3780 | return 0; | |
3781 | } | |
3782 | ||
f71b2f64 KKD |
3783 | static int btf_field_offs_cmp(const void *_a, const void *_b, const void *priv) |
3784 | { | |
3785 | const u32 a = *(const u32 *)_a; | |
3786 | const u32 b = *(const u32 *)_b; | |
3787 | ||
3788 | if (a < b) | |
3789 | return -1; | |
3790 | else if (a > b) | |
3791 | return 1; | |
3792 | return 0; | |
3793 | } | |
3794 | ||
3795 | static void btf_field_offs_swap(void *_a, void *_b, int size, const void *priv) | |
3796 | { | |
3797 | struct btf_field_offs *foffs = (void *)priv; | |
3798 | u32 *off_base = foffs->field_off; | |
3799 | u32 *a = _a, *b = _b; | |
3800 | u8 *sz_a, *sz_b; | |
3801 | ||
3802 | sz_a = foffs->field_sz + (a - off_base); | |
3803 | sz_b = foffs->field_sz + (b - off_base); | |
3804 | ||
3805 | swap(*a, *b); | |
3806 | swap(*sz_a, *sz_b); | |
3807 | } | |
3808 | ||
3809 | struct btf_field_offs *btf_parse_field_offs(struct btf_record *rec) | |
3810 | { | |
3811 | struct btf_field_offs *foffs; | |
3812 | u32 i, *off; | |
3813 | u8 *sz; | |
3814 | ||
3815 | BUILD_BUG_ON(ARRAY_SIZE(foffs->field_off) != ARRAY_SIZE(foffs->field_sz)); | |
2d577252 | 3816 | if (IS_ERR_OR_NULL(rec)) |
f71b2f64 KKD |
3817 | return NULL; |
3818 | ||
3819 | foffs = kzalloc(sizeof(*foffs), GFP_KERNEL | __GFP_NOWARN); | |
3820 | if (!foffs) | |
3821 | return ERR_PTR(-ENOMEM); | |
3822 | ||
3823 | off = foffs->field_off; | |
3824 | sz = foffs->field_sz; | |
3825 | for (i = 0; i < rec->cnt; i++) { | |
3826 | off[i] = rec->fields[i].offset; | |
3827 | sz[i] = btf_field_type_size(rec->fields[i].type); | |
3828 | } | |
3829 | foffs->cnt = rec->cnt; | |
3830 | ||
3831 | if (foffs->cnt == 1) | |
3832 | return foffs; | |
3833 | sort_r(foffs->field_off, foffs->cnt, sizeof(foffs->field_off[0]), | |
3834 | btf_field_offs_cmp, btf_field_offs_swap, foffs); | |
3835 | return foffs; | |
3836 | } | |
3837 | ||
31d0bc81 AM |
3838 | static void __btf_struct_show(const struct btf *btf, const struct btf_type *t, |
3839 | u32 type_id, void *data, u8 bits_offset, | |
3840 | struct btf_show *show) | |
b00b8dae | 3841 | { |
b00b8dae | 3842 | const struct btf_member *member; |
31d0bc81 | 3843 | void *safe_data; |
b00b8dae MKL |
3844 | u32 i; |
3845 | ||
31d0bc81 AM |
3846 | safe_data = btf_show_start_struct_type(show, t, type_id, data); |
3847 | if (!safe_data) | |
3848 | return; | |
3849 | ||
b00b8dae MKL |
3850 | for_each_member(i, t, member) { |
3851 | const struct btf_type *member_type = btf_type_by_id(btf, | |
3852 | member->type); | |
b00b8dae | 3853 | const struct btf_kind_operations *ops; |
9d5f9f70 YS |
3854 | u32 member_offset, bitfield_size; |
3855 | u32 bytes_offset; | |
3856 | u8 bits8_offset; | |
b00b8dae | 3857 | |
31d0bc81 | 3858 | btf_show_start_member(show, member); |
b00b8dae | 3859 | |
8293eb99 AS |
3860 | member_offset = __btf_member_bit_offset(t, member); |
3861 | bitfield_size = __btf_member_bitfield_size(t, member); | |
17e3ac81 YS |
3862 | bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset); |
3863 | bits8_offset = BITS_PER_BYTE_MASKED(member_offset); | |
9d5f9f70 | 3864 | if (bitfield_size) { |
31d0bc81 AM |
3865 | safe_data = btf_show_start_type(show, member_type, |
3866 | member->type, | |
3867 | data + bytes_offset); | |
3868 | if (safe_data) | |
3869 | btf_bitfield_show(safe_data, | |
3870 | bits8_offset, | |
3871 | bitfield_size, show); | |
3872 | btf_show_end_type(show); | |
9d5f9f70 | 3873 | } else { |
9d5f9f70 | 3874 | ops = btf_type_ops(member_type); |
31d0bc81 AM |
3875 | ops->show(btf, member_type, member->type, |
3876 | data + bytes_offset, bits8_offset, show); | |
9d5f9f70 | 3877 | } |
31d0bc81 AM |
3878 | |
3879 | btf_show_end_member(show); | |
b00b8dae | 3880 | } |
31d0bc81 AM |
3881 | |
3882 | btf_show_end_struct_type(show); | |
3883 | } | |
3884 | ||
3885 | static void btf_struct_show(const struct btf *btf, const struct btf_type *t, | |
3886 | u32 type_id, void *data, u8 bits_offset, | |
3887 | struct btf_show *show) | |
3888 | { | |
3889 | const struct btf_member *m = show->state.member; | |
3890 | ||
3891 | /* | |
3892 | * First check if any members would be shown (are non-zero). | |
3893 | * See comments above "struct btf_show" definition for more | |
3894 | * details on how this works at a high-level. | |
3895 | */ | |
3896 | if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) { | |
3897 | if (!show->state.depth_check) { | |
3898 | show->state.depth_check = show->state.depth + 1; | |
3899 | show->state.depth_to_show = 0; | |
3900 | } | |
3901 | __btf_struct_show(btf, t, type_id, data, bits_offset, show); | |
3902 | /* Restore saved member data here */ | |
3903 | show->state.member = m; | |
3904 | if (show->state.depth_check != show->state.depth + 1) | |
3905 | return; | |
3906 | show->state.depth_check = 0; | |
3907 | ||
3908 | if (show->state.depth_to_show <= show->state.depth) | |
3909 | return; | |
3910 | /* | |
3911 | * Reaching here indicates we have recursed and found | |
3912 | * non-zero child values. | |
3913 | */ | |
3914 | } | |
3915 | ||
3916 | __btf_struct_show(btf, t, type_id, data, bits_offset, show); | |
b00b8dae MKL |
3917 | } |
3918 | ||
69b693f0 MKL |
3919 | static struct btf_kind_operations struct_ops = { |
3920 | .check_meta = btf_struct_check_meta, | |
eb3f595d | 3921 | .resolve = btf_struct_resolve, |
179cde8c | 3922 | .check_member = btf_struct_check_member, |
9d5f9f70 | 3923 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 3924 | .log_details = btf_struct_log, |
31d0bc81 | 3925 | .show = btf_struct_show, |
69b693f0 MKL |
3926 | }; |
3927 | ||
179cde8c MKL |
3928 | static int btf_enum_check_member(struct btf_verifier_env *env, |
3929 | const struct btf_type *struct_type, | |
3930 | const struct btf_member *member, | |
3931 | const struct btf_type *member_type) | |
3932 | { | |
3933 | u32 struct_bits_off = member->offset; | |
3934 | u32 struct_size, bytes_offset; | |
3935 | ||
3936 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
3937 | btf_verifier_log_member(env, struct_type, member, | |
3938 | "Member is not byte aligned"); | |
3939 | return -EINVAL; | |
3940 | } | |
3941 | ||
3942 | struct_size = struct_type->size; | |
3943 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
da6c7fae | 3944 | if (struct_size - bytes_offset < member_type->size) { |
179cde8c MKL |
3945 | btf_verifier_log_member(env, struct_type, member, |
3946 | "Member exceeds struct_size"); | |
3947 | return -EINVAL; | |
3948 | } | |
3949 | ||
3950 | return 0; | |
3951 | } | |
3952 | ||
9d5f9f70 YS |
3953 | static int btf_enum_check_kflag_member(struct btf_verifier_env *env, |
3954 | const struct btf_type *struct_type, | |
3955 | const struct btf_member *member, | |
3956 | const struct btf_type *member_type) | |
3957 | { | |
3958 | u32 struct_bits_off, nr_bits, bytes_end, struct_size; | |
3959 | u32 int_bitsize = sizeof(int) * BITS_PER_BYTE; | |
3960 | ||
3961 | struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); | |
3962 | nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); | |
3963 | if (!nr_bits) { | |
3964 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
3965 | btf_verifier_log_member(env, struct_type, member, | |
3966 | "Member is not byte aligned"); | |
e3439af4 | 3967 | return -EINVAL; |
9d5f9f70 YS |
3968 | } |
3969 | ||
3970 | nr_bits = int_bitsize; | |
3971 | } else if (nr_bits > int_bitsize) { | |
3972 | btf_verifier_log_member(env, struct_type, member, | |
3973 | "Invalid member bitfield_size"); | |
3974 | return -EINVAL; | |
3975 | } | |
3976 | ||
3977 | struct_size = struct_type->size; | |
3978 | bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits); | |
3979 | if (struct_size < bytes_end) { | |
3980 | btf_verifier_log_member(env, struct_type, member, | |
3981 | "Member exceeds struct_size"); | |
3982 | return -EINVAL; | |
3983 | } | |
3984 | ||
3985 | return 0; | |
3986 | } | |
3987 | ||
69b693f0 MKL |
3988 | static s32 btf_enum_check_meta(struct btf_verifier_env *env, |
3989 | const struct btf_type *t, | |
3990 | u32 meta_left) | |
3991 | { | |
3992 | const struct btf_enum *enums = btf_type_enum(t); | |
3993 | struct btf *btf = env->btf; | |
6089fb32 | 3994 | const char *fmt_str; |
69b693f0 MKL |
3995 | u16 i, nr_enums; |
3996 | u32 meta_needed; | |
3997 | ||
3998 | nr_enums = btf_type_vlen(t); | |
3999 | meta_needed = nr_enums * sizeof(*enums); | |
4000 | ||
4001 | if (meta_left < meta_needed) { | |
4002 | btf_verifier_log_basic(env, t, | |
4003 | "meta_left:%u meta_needed:%u", | |
4004 | meta_left, meta_needed); | |
4005 | return -EINVAL; | |
4006 | } | |
4007 | ||
9eea9849 AS |
4008 | if (t->size > 8 || !is_power_of_2(t->size)) { |
4009 | btf_verifier_log_type(env, t, "Unexpected size"); | |
69b693f0 MKL |
4010 | return -EINVAL; |
4011 | } | |
4012 | ||
eb04bbb6 YS |
4013 | /* enum type either no name or a valid one */ |
4014 | if (t->name_off && | |
4015 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
4016 | btf_verifier_log_type(env, t, "Invalid name"); | |
4017 | return -EINVAL; | |
4018 | } | |
4019 | ||
69b693f0 MKL |
4020 | btf_verifier_log_type(env, t, NULL); |
4021 | ||
4022 | for (i = 0; i < nr_enums; i++) { | |
fbcf93eb | 4023 | if (!btf_name_offset_valid(btf, enums[i].name_off)) { |
69b693f0 | 4024 | btf_verifier_log(env, "\tInvalid name_offset:%u", |
fbcf93eb | 4025 | enums[i].name_off); |
69b693f0 MKL |
4026 | return -EINVAL; |
4027 | } | |
4028 | ||
eb04bbb6 YS |
4029 | /* enum member must have a valid name */ |
4030 | if (!enums[i].name_off || | |
4031 | !btf_name_valid_identifier(btf, enums[i].name_off)) { | |
4032 | btf_verifier_log_type(env, t, "Invalid name"); | |
4033 | return -EINVAL; | |
4034 | } | |
4035 | ||
8580ac94 AS |
4036 | if (env->log.level == BPF_LOG_KERNEL) |
4037 | continue; | |
6089fb32 YS |
4038 | fmt_str = btf_type_kflag(t) ? "\t%s val=%d\n" : "\t%s val=%u\n"; |
4039 | btf_verifier_log(env, fmt_str, | |
23127b33 | 4040 | __btf_name_by_offset(btf, enums[i].name_off), |
69b693f0 MKL |
4041 | enums[i].val); |
4042 | } | |
4043 | ||
4044 | return meta_needed; | |
4045 | } | |
4046 | ||
4047 | static void btf_enum_log(struct btf_verifier_env *env, | |
4048 | const struct btf_type *t) | |
4049 | { | |
4050 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
4051 | } | |
4052 | ||
31d0bc81 AM |
4053 | static void btf_enum_show(const struct btf *btf, const struct btf_type *t, |
4054 | u32 type_id, void *data, u8 bits_offset, | |
4055 | struct btf_show *show) | |
b00b8dae MKL |
4056 | { |
4057 | const struct btf_enum *enums = btf_type_enum(t); | |
4058 | u32 i, nr_enums = btf_type_vlen(t); | |
31d0bc81 AM |
4059 | void *safe_data; |
4060 | int v; | |
4061 | ||
4062 | safe_data = btf_show_start_type(show, t, type_id, data); | |
4063 | if (!safe_data) | |
4064 | return; | |
4065 | ||
4066 | v = *(int *)safe_data; | |
b00b8dae MKL |
4067 | |
4068 | for (i = 0; i < nr_enums; i++) { | |
31d0bc81 AM |
4069 | if (v != enums[i].val) |
4070 | continue; | |
4071 | ||
4072 | btf_show_type_value(show, "%s", | |
4073 | __btf_name_by_offset(btf, | |
4074 | enums[i].name_off)); | |
4075 | ||
4076 | btf_show_end_type(show); | |
4077 | return; | |
b00b8dae MKL |
4078 | } |
4079 | ||
6089fb32 YS |
4080 | if (btf_type_kflag(t)) |
4081 | btf_show_type_value(show, "%d", v); | |
4082 | else | |
4083 | btf_show_type_value(show, "%u", v); | |
31d0bc81 | 4084 | btf_show_end_type(show); |
b00b8dae MKL |
4085 | } |
4086 | ||
69b693f0 MKL |
4087 | static struct btf_kind_operations enum_ops = { |
4088 | .check_meta = btf_enum_check_meta, | |
eb3f595d | 4089 | .resolve = btf_df_resolve, |
179cde8c | 4090 | .check_member = btf_enum_check_member, |
9d5f9f70 | 4091 | .check_kflag_member = btf_enum_check_kflag_member, |
69b693f0 | 4092 | .log_details = btf_enum_log, |
31d0bc81 | 4093 | .show = btf_enum_show, |
69b693f0 MKL |
4094 | }; |
4095 | ||
6089fb32 YS |
4096 | static s32 btf_enum64_check_meta(struct btf_verifier_env *env, |
4097 | const struct btf_type *t, | |
4098 | u32 meta_left) | |
4099 | { | |
4100 | const struct btf_enum64 *enums = btf_type_enum64(t); | |
4101 | struct btf *btf = env->btf; | |
4102 | const char *fmt_str; | |
4103 | u16 i, nr_enums; | |
4104 | u32 meta_needed; | |
4105 | ||
4106 | nr_enums = btf_type_vlen(t); | |
4107 | meta_needed = nr_enums * sizeof(*enums); | |
4108 | ||
4109 | if (meta_left < meta_needed) { | |
4110 | btf_verifier_log_basic(env, t, | |
4111 | "meta_left:%u meta_needed:%u", | |
4112 | meta_left, meta_needed); | |
4113 | return -EINVAL; | |
4114 | } | |
4115 | ||
4116 | if (t->size > 8 || !is_power_of_2(t->size)) { | |
4117 | btf_verifier_log_type(env, t, "Unexpected size"); | |
4118 | return -EINVAL; | |
4119 | } | |
4120 | ||
4121 | /* enum type either no name or a valid one */ | |
4122 | if (t->name_off && | |
4123 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
4124 | btf_verifier_log_type(env, t, "Invalid name"); | |
4125 | return -EINVAL; | |
4126 | } | |
4127 | ||
4128 | btf_verifier_log_type(env, t, NULL); | |
4129 | ||
4130 | for (i = 0; i < nr_enums; i++) { | |
4131 | if (!btf_name_offset_valid(btf, enums[i].name_off)) { | |
4132 | btf_verifier_log(env, "\tInvalid name_offset:%u", | |
4133 | enums[i].name_off); | |
4134 | return -EINVAL; | |
4135 | } | |
4136 | ||
4137 | /* enum member must have a valid name */ | |
4138 | if (!enums[i].name_off || | |
4139 | !btf_name_valid_identifier(btf, enums[i].name_off)) { | |
4140 | btf_verifier_log_type(env, t, "Invalid name"); | |
4141 | return -EINVAL; | |
4142 | } | |
4143 | ||
4144 | if (env->log.level == BPF_LOG_KERNEL) | |
4145 | continue; | |
4146 | ||
4147 | fmt_str = btf_type_kflag(t) ? "\t%s val=%lld\n" : "\t%s val=%llu\n"; | |
4148 | btf_verifier_log(env, fmt_str, | |
4149 | __btf_name_by_offset(btf, enums[i].name_off), | |
4150 | btf_enum64_value(enums + i)); | |
4151 | } | |
4152 | ||
4153 | return meta_needed; | |
4154 | } | |
4155 | ||
4156 | static void btf_enum64_show(const struct btf *btf, const struct btf_type *t, | |
4157 | u32 type_id, void *data, u8 bits_offset, | |
4158 | struct btf_show *show) | |
4159 | { | |
4160 | const struct btf_enum64 *enums = btf_type_enum64(t); | |
4161 | u32 i, nr_enums = btf_type_vlen(t); | |
4162 | void *safe_data; | |
4163 | s64 v; | |
4164 | ||
4165 | safe_data = btf_show_start_type(show, t, type_id, data); | |
4166 | if (!safe_data) | |
4167 | return; | |
4168 | ||
4169 | v = *(u64 *)safe_data; | |
4170 | ||
4171 | for (i = 0; i < nr_enums; i++) { | |
4172 | if (v != btf_enum64_value(enums + i)) | |
4173 | continue; | |
4174 | ||
4175 | btf_show_type_value(show, "%s", | |
4176 | __btf_name_by_offset(btf, | |
4177 | enums[i].name_off)); | |
4178 | ||
4179 | btf_show_end_type(show); | |
4180 | return; | |
4181 | } | |
4182 | ||
4183 | if (btf_type_kflag(t)) | |
4184 | btf_show_type_value(show, "%lld", v); | |
4185 | else | |
4186 | btf_show_type_value(show, "%llu", v); | |
4187 | btf_show_end_type(show); | |
4188 | } | |
4189 | ||
4190 | static struct btf_kind_operations enum64_ops = { | |
4191 | .check_meta = btf_enum64_check_meta, | |
4192 | .resolve = btf_df_resolve, | |
4193 | .check_member = btf_enum_check_member, | |
4194 | .check_kflag_member = btf_enum_check_kflag_member, | |
4195 | .log_details = btf_enum_log, | |
4196 | .show = btf_enum64_show, | |
4197 | }; | |
4198 | ||
2667a262 MKL |
4199 | static s32 btf_func_proto_check_meta(struct btf_verifier_env *env, |
4200 | const struct btf_type *t, | |
4201 | u32 meta_left) | |
4202 | { | |
4203 | u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param); | |
4204 | ||
4205 | if (meta_left < meta_needed) { | |
4206 | btf_verifier_log_basic(env, t, | |
4207 | "meta_left:%u meta_needed:%u", | |
4208 | meta_left, meta_needed); | |
4209 | return -EINVAL; | |
4210 | } | |
4211 | ||
4212 | if (t->name_off) { | |
4213 | btf_verifier_log_type(env, t, "Invalid name"); | |
4214 | return -EINVAL; | |
4215 | } | |
4216 | ||
9d5f9f70 YS |
4217 | if (btf_type_kflag(t)) { |
4218 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4219 | return -EINVAL; | |
4220 | } | |
4221 | ||
2667a262 MKL |
4222 | btf_verifier_log_type(env, t, NULL); |
4223 | ||
4224 | return meta_needed; | |
4225 | } | |
4226 | ||
4227 | static void btf_func_proto_log(struct btf_verifier_env *env, | |
4228 | const struct btf_type *t) | |
4229 | { | |
4230 | const struct btf_param *args = (const struct btf_param *)(t + 1); | |
4231 | u16 nr_args = btf_type_vlen(t), i; | |
4232 | ||
4233 | btf_verifier_log(env, "return=%u args=(", t->type); | |
4234 | if (!nr_args) { | |
4235 | btf_verifier_log(env, "void"); | |
4236 | goto done; | |
4237 | } | |
4238 | ||
4239 | if (nr_args == 1 && !args[0].type) { | |
4240 | /* Only one vararg */ | |
4241 | btf_verifier_log(env, "vararg"); | |
4242 | goto done; | |
4243 | } | |
4244 | ||
4245 | btf_verifier_log(env, "%u %s", args[0].type, | |
23127b33 MKL |
4246 | __btf_name_by_offset(env->btf, |
4247 | args[0].name_off)); | |
2667a262 MKL |
4248 | for (i = 1; i < nr_args - 1; i++) |
4249 | btf_verifier_log(env, ", %u %s", args[i].type, | |
23127b33 MKL |
4250 | __btf_name_by_offset(env->btf, |
4251 | args[i].name_off)); | |
2667a262 MKL |
4252 | |
4253 | if (nr_args > 1) { | |
4254 | const struct btf_param *last_arg = &args[nr_args - 1]; | |
4255 | ||
4256 | if (last_arg->type) | |
4257 | btf_verifier_log(env, ", %u %s", last_arg->type, | |
23127b33 MKL |
4258 | __btf_name_by_offset(env->btf, |
4259 | last_arg->name_off)); | |
2667a262 MKL |
4260 | else |
4261 | btf_verifier_log(env, ", vararg"); | |
4262 | } | |
4263 | ||
4264 | done: | |
4265 | btf_verifier_log(env, ")"); | |
4266 | } | |
4267 | ||
4268 | static struct btf_kind_operations func_proto_ops = { | |
4269 | .check_meta = btf_func_proto_check_meta, | |
4270 | .resolve = btf_df_resolve, | |
4271 | /* | |
4272 | * BTF_KIND_FUNC_PROTO cannot be directly referred by | |
4273 | * a struct's member. | |
4274 | * | |
8fb33b60 | 4275 | * It should be a function pointer instead. |
2667a262 MKL |
4276 | * (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO) |
4277 | * | |
4278 | * Hence, there is no btf_func_check_member(). | |
4279 | */ | |
4280 | .check_member = btf_df_check_member, | |
9d5f9f70 | 4281 | .check_kflag_member = btf_df_check_kflag_member, |
2667a262 | 4282 | .log_details = btf_func_proto_log, |
31d0bc81 | 4283 | .show = btf_df_show, |
2667a262 MKL |
4284 | }; |
4285 | ||
4286 | static s32 btf_func_check_meta(struct btf_verifier_env *env, | |
4287 | const struct btf_type *t, | |
4288 | u32 meta_left) | |
4289 | { | |
4290 | if (!t->name_off || | |
4291 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
4292 | btf_verifier_log_type(env, t, "Invalid name"); | |
4293 | return -EINVAL; | |
4294 | } | |
4295 | ||
51c39bb1 AS |
4296 | if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) { |
4297 | btf_verifier_log_type(env, t, "Invalid func linkage"); | |
2667a262 MKL |
4298 | return -EINVAL; |
4299 | } | |
4300 | ||
9d5f9f70 YS |
4301 | if (btf_type_kflag(t)) { |
4302 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4303 | return -EINVAL; | |
4304 | } | |
4305 | ||
2667a262 MKL |
4306 | btf_verifier_log_type(env, t, NULL); |
4307 | ||
4308 | return 0; | |
4309 | } | |
4310 | ||
d7e7b42f YS |
4311 | static int btf_func_resolve(struct btf_verifier_env *env, |
4312 | const struct resolve_vertex *v) | |
4313 | { | |
4314 | const struct btf_type *t = v->t; | |
4315 | u32 next_type_id = t->type; | |
4316 | int err; | |
4317 | ||
4318 | err = btf_func_check(env, t); | |
4319 | if (err) | |
4320 | return err; | |
4321 | ||
4322 | env_stack_pop_resolved(env, next_type_id, 0); | |
4323 | return 0; | |
4324 | } | |
4325 | ||
2667a262 MKL |
4326 | static struct btf_kind_operations func_ops = { |
4327 | .check_meta = btf_func_check_meta, | |
d7e7b42f | 4328 | .resolve = btf_func_resolve, |
2667a262 | 4329 | .check_member = btf_df_check_member, |
9d5f9f70 | 4330 | .check_kflag_member = btf_df_check_kflag_member, |
2667a262 | 4331 | .log_details = btf_ref_type_log, |
31d0bc81 | 4332 | .show = btf_df_show, |
2667a262 MKL |
4333 | }; |
4334 | ||
1dc92851 DB |
4335 | static s32 btf_var_check_meta(struct btf_verifier_env *env, |
4336 | const struct btf_type *t, | |
4337 | u32 meta_left) | |
4338 | { | |
4339 | const struct btf_var *var; | |
4340 | u32 meta_needed = sizeof(*var); | |
4341 | ||
4342 | if (meta_left < meta_needed) { | |
4343 | btf_verifier_log_basic(env, t, | |
4344 | "meta_left:%u meta_needed:%u", | |
4345 | meta_left, meta_needed); | |
4346 | return -EINVAL; | |
4347 | } | |
4348 | ||
4349 | if (btf_type_vlen(t)) { | |
4350 | btf_verifier_log_type(env, t, "vlen != 0"); | |
4351 | return -EINVAL; | |
4352 | } | |
4353 | ||
4354 | if (btf_type_kflag(t)) { | |
4355 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4356 | return -EINVAL; | |
4357 | } | |
4358 | ||
4359 | if (!t->name_off || | |
4360 | !__btf_name_valid(env->btf, t->name_off, true)) { | |
4361 | btf_verifier_log_type(env, t, "Invalid name"); | |
4362 | return -EINVAL; | |
4363 | } | |
4364 | ||
4365 | /* A var cannot be in type void */ | |
4366 | if (!t->type || !BTF_TYPE_ID_VALID(t->type)) { | |
4367 | btf_verifier_log_type(env, t, "Invalid type_id"); | |
4368 | return -EINVAL; | |
4369 | } | |
4370 | ||
4371 | var = btf_type_var(t); | |
4372 | if (var->linkage != BTF_VAR_STATIC && | |
4373 | var->linkage != BTF_VAR_GLOBAL_ALLOCATED) { | |
4374 | btf_verifier_log_type(env, t, "Linkage not supported"); | |
4375 | return -EINVAL; | |
4376 | } | |
4377 | ||
4378 | btf_verifier_log_type(env, t, NULL); | |
4379 | ||
4380 | return meta_needed; | |
4381 | } | |
4382 | ||
4383 | static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t) | |
4384 | { | |
4385 | const struct btf_var *var = btf_type_var(t); | |
4386 | ||
4387 | btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage); | |
4388 | } | |
4389 | ||
4390 | static const struct btf_kind_operations var_ops = { | |
4391 | .check_meta = btf_var_check_meta, | |
4392 | .resolve = btf_var_resolve, | |
4393 | .check_member = btf_df_check_member, | |
4394 | .check_kflag_member = btf_df_check_kflag_member, | |
4395 | .log_details = btf_var_log, | |
31d0bc81 | 4396 | .show = btf_var_show, |
1dc92851 DB |
4397 | }; |
4398 | ||
4399 | static s32 btf_datasec_check_meta(struct btf_verifier_env *env, | |
4400 | const struct btf_type *t, | |
4401 | u32 meta_left) | |
4402 | { | |
4403 | const struct btf_var_secinfo *vsi; | |
4404 | u64 last_vsi_end_off = 0, sum = 0; | |
4405 | u32 i, meta_needed; | |
4406 | ||
4407 | meta_needed = btf_type_vlen(t) * sizeof(*vsi); | |
4408 | if (meta_left < meta_needed) { | |
4409 | btf_verifier_log_basic(env, t, | |
4410 | "meta_left:%u meta_needed:%u", | |
4411 | meta_left, meta_needed); | |
4412 | return -EINVAL; | |
4413 | } | |
4414 | ||
1dc92851 DB |
4415 | if (!t->size) { |
4416 | btf_verifier_log_type(env, t, "size == 0"); | |
4417 | return -EINVAL; | |
4418 | } | |
4419 | ||
4420 | if (btf_type_kflag(t)) { | |
4421 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4422 | return -EINVAL; | |
4423 | } | |
4424 | ||
4425 | if (!t->name_off || | |
4426 | !btf_name_valid_section(env->btf, t->name_off)) { | |
4427 | btf_verifier_log_type(env, t, "Invalid name"); | |
4428 | return -EINVAL; | |
4429 | } | |
4430 | ||
4431 | btf_verifier_log_type(env, t, NULL); | |
4432 | ||
4433 | for_each_vsi(i, t, vsi) { | |
4434 | /* A var cannot be in type void */ | |
4435 | if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) { | |
4436 | btf_verifier_log_vsi(env, t, vsi, | |
4437 | "Invalid type_id"); | |
4438 | return -EINVAL; | |
4439 | } | |
4440 | ||
4441 | if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) { | |
4442 | btf_verifier_log_vsi(env, t, vsi, | |
4443 | "Invalid offset"); | |
4444 | return -EINVAL; | |
4445 | } | |
4446 | ||
4447 | if (!vsi->size || vsi->size > t->size) { | |
4448 | btf_verifier_log_vsi(env, t, vsi, | |
4449 | "Invalid size"); | |
4450 | return -EINVAL; | |
4451 | } | |
4452 | ||
4453 | last_vsi_end_off = vsi->offset + vsi->size; | |
4454 | if (last_vsi_end_off > t->size) { | |
4455 | btf_verifier_log_vsi(env, t, vsi, | |
4456 | "Invalid offset+size"); | |
4457 | return -EINVAL; | |
4458 | } | |
4459 | ||
4460 | btf_verifier_log_vsi(env, t, vsi, NULL); | |
4461 | sum += vsi->size; | |
4462 | } | |
4463 | ||
4464 | if (t->size < sum) { | |
4465 | btf_verifier_log_type(env, t, "Invalid btf_info size"); | |
4466 | return -EINVAL; | |
4467 | } | |
4468 | ||
4469 | return meta_needed; | |
4470 | } | |
4471 | ||
4472 | static int btf_datasec_resolve(struct btf_verifier_env *env, | |
4473 | const struct resolve_vertex *v) | |
4474 | { | |
4475 | const struct btf_var_secinfo *vsi; | |
4476 | struct btf *btf = env->btf; | |
4477 | u16 i; | |
4478 | ||
4479 | for_each_vsi_from(i, v->next_member, v->t, vsi) { | |
4480 | u32 var_type_id = vsi->type, type_id, type_size = 0; | |
4481 | const struct btf_type *var_type = btf_type_by_id(env->btf, | |
4482 | var_type_id); | |
4483 | if (!var_type || !btf_type_is_var(var_type)) { | |
4484 | btf_verifier_log_vsi(env, v->t, vsi, | |
4485 | "Not a VAR kind member"); | |
4486 | return -EINVAL; | |
4487 | } | |
4488 | ||
4489 | if (!env_type_is_resolve_sink(env, var_type) && | |
4490 | !env_type_is_resolved(env, var_type_id)) { | |
4491 | env_stack_set_next_member(env, i + 1); | |
4492 | return env_stack_push(env, var_type, var_type_id); | |
4493 | } | |
4494 | ||
4495 | type_id = var_type->type; | |
4496 | if (!btf_type_id_size(btf, &type_id, &type_size)) { | |
4497 | btf_verifier_log_vsi(env, v->t, vsi, "Invalid type"); | |
4498 | return -EINVAL; | |
4499 | } | |
4500 | ||
4501 | if (vsi->size < type_size) { | |
4502 | btf_verifier_log_vsi(env, v->t, vsi, "Invalid size"); | |
4503 | return -EINVAL; | |
4504 | } | |
4505 | } | |
4506 | ||
4507 | env_stack_pop_resolved(env, 0, 0); | |
4508 | return 0; | |
4509 | } | |
4510 | ||
4511 | static void btf_datasec_log(struct btf_verifier_env *env, | |
4512 | const struct btf_type *t) | |
4513 | { | |
4514 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
4515 | } | |
4516 | ||
31d0bc81 AM |
4517 | static void btf_datasec_show(const struct btf *btf, |
4518 | const struct btf_type *t, u32 type_id, | |
4519 | void *data, u8 bits_offset, | |
4520 | struct btf_show *show) | |
1dc92851 DB |
4521 | { |
4522 | const struct btf_var_secinfo *vsi; | |
4523 | const struct btf_type *var; | |
4524 | u32 i; | |
4525 | ||
31d0bc81 AM |
4526 | if (!btf_show_start_type(show, t, type_id, data)) |
4527 | return; | |
4528 | ||
4529 | btf_show_type_value(show, "section (\"%s\") = {", | |
4530 | __btf_name_by_offset(btf, t->name_off)); | |
1dc92851 DB |
4531 | for_each_vsi(i, t, vsi) { |
4532 | var = btf_type_by_id(btf, vsi->type); | |
4533 | if (i) | |
31d0bc81 AM |
4534 | btf_show(show, ","); |
4535 | btf_type_ops(var)->show(btf, var, vsi->type, | |
4536 | data + vsi->offset, bits_offset, show); | |
1dc92851 | 4537 | } |
31d0bc81 | 4538 | btf_show_end_type(show); |
1dc92851 DB |
4539 | } |
4540 | ||
4541 | static const struct btf_kind_operations datasec_ops = { | |
4542 | .check_meta = btf_datasec_check_meta, | |
4543 | .resolve = btf_datasec_resolve, | |
4544 | .check_member = btf_df_check_member, | |
4545 | .check_kflag_member = btf_df_check_kflag_member, | |
4546 | .log_details = btf_datasec_log, | |
31d0bc81 | 4547 | .show = btf_datasec_show, |
1dc92851 DB |
4548 | }; |
4549 | ||
b1828f0b IL |
4550 | static s32 btf_float_check_meta(struct btf_verifier_env *env, |
4551 | const struct btf_type *t, | |
4552 | u32 meta_left) | |
4553 | { | |
4554 | if (btf_type_vlen(t)) { | |
4555 | btf_verifier_log_type(env, t, "vlen != 0"); | |
4556 | return -EINVAL; | |
4557 | } | |
4558 | ||
4559 | if (btf_type_kflag(t)) { | |
4560 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4561 | return -EINVAL; | |
4562 | } | |
4563 | ||
4564 | if (t->size != 2 && t->size != 4 && t->size != 8 && t->size != 12 && | |
4565 | t->size != 16) { | |
4566 | btf_verifier_log_type(env, t, "Invalid type_size"); | |
4567 | return -EINVAL; | |
4568 | } | |
4569 | ||
4570 | btf_verifier_log_type(env, t, NULL); | |
4571 | ||
4572 | return 0; | |
4573 | } | |
4574 | ||
4575 | static int btf_float_check_member(struct btf_verifier_env *env, | |
4576 | const struct btf_type *struct_type, | |
4577 | const struct btf_member *member, | |
4578 | const struct btf_type *member_type) | |
4579 | { | |
4580 | u64 start_offset_bytes; | |
4581 | u64 end_offset_bytes; | |
4582 | u64 misalign_bits; | |
4583 | u64 align_bytes; | |
4584 | u64 align_bits; | |
4585 | ||
4586 | /* Different architectures have different alignment requirements, so | |
4587 | * here we check only for the reasonable minimum. This way we ensure | |
4588 | * that types after CO-RE can pass the kernel BTF verifier. | |
4589 | */ | |
4590 | align_bytes = min_t(u64, sizeof(void *), member_type->size); | |
4591 | align_bits = align_bytes * BITS_PER_BYTE; | |
4592 | div64_u64_rem(member->offset, align_bits, &misalign_bits); | |
4593 | if (misalign_bits) { | |
4594 | btf_verifier_log_member(env, struct_type, member, | |
4595 | "Member is not properly aligned"); | |
4596 | return -EINVAL; | |
4597 | } | |
4598 | ||
4599 | start_offset_bytes = member->offset / BITS_PER_BYTE; | |
4600 | end_offset_bytes = start_offset_bytes + member_type->size; | |
4601 | if (end_offset_bytes > struct_type->size) { | |
4602 | btf_verifier_log_member(env, struct_type, member, | |
4603 | "Member exceeds struct_size"); | |
4604 | return -EINVAL; | |
4605 | } | |
4606 | ||
4607 | return 0; | |
4608 | } | |
4609 | ||
4610 | static void btf_float_log(struct btf_verifier_env *env, | |
4611 | const struct btf_type *t) | |
4612 | { | |
4613 | btf_verifier_log(env, "size=%u", t->size); | |
4614 | } | |
4615 | ||
4616 | static const struct btf_kind_operations float_ops = { | |
4617 | .check_meta = btf_float_check_meta, | |
4618 | .resolve = btf_df_resolve, | |
4619 | .check_member = btf_float_check_member, | |
4620 | .check_kflag_member = btf_generic_check_kflag_member, | |
4621 | .log_details = btf_float_log, | |
4622 | .show = btf_df_show, | |
4623 | }; | |
4624 | ||
223f903e | 4625 | static s32 btf_decl_tag_check_meta(struct btf_verifier_env *env, |
b5ea834d YS |
4626 | const struct btf_type *t, |
4627 | u32 meta_left) | |
4628 | { | |
223f903e | 4629 | const struct btf_decl_tag *tag; |
b5ea834d YS |
4630 | u32 meta_needed = sizeof(*tag); |
4631 | s32 component_idx; | |
4632 | const char *value; | |
4633 | ||
4634 | if (meta_left < meta_needed) { | |
4635 | btf_verifier_log_basic(env, t, | |
4636 | "meta_left:%u meta_needed:%u", | |
4637 | meta_left, meta_needed); | |
4638 | return -EINVAL; | |
4639 | } | |
4640 | ||
4641 | value = btf_name_by_offset(env->btf, t->name_off); | |
4642 | if (!value || !value[0]) { | |
4643 | btf_verifier_log_type(env, t, "Invalid value"); | |
4644 | return -EINVAL; | |
4645 | } | |
4646 | ||
4647 | if (btf_type_vlen(t)) { | |
4648 | btf_verifier_log_type(env, t, "vlen != 0"); | |
4649 | return -EINVAL; | |
4650 | } | |
4651 | ||
4652 | if (btf_type_kflag(t)) { | |
4653 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4654 | return -EINVAL; | |
4655 | } | |
4656 | ||
223f903e | 4657 | component_idx = btf_type_decl_tag(t)->component_idx; |
b5ea834d YS |
4658 | if (component_idx < -1) { |
4659 | btf_verifier_log_type(env, t, "Invalid component_idx"); | |
4660 | return -EINVAL; | |
4661 | } | |
4662 | ||
4663 | btf_verifier_log_type(env, t, NULL); | |
4664 | ||
4665 | return meta_needed; | |
4666 | } | |
4667 | ||
223f903e | 4668 | static int btf_decl_tag_resolve(struct btf_verifier_env *env, |
b5ea834d YS |
4669 | const struct resolve_vertex *v) |
4670 | { | |
4671 | const struct btf_type *next_type; | |
4672 | const struct btf_type *t = v->t; | |
4673 | u32 next_type_id = t->type; | |
4674 | struct btf *btf = env->btf; | |
4675 | s32 component_idx; | |
4676 | u32 vlen; | |
4677 | ||
4678 | next_type = btf_type_by_id(btf, next_type_id); | |
223f903e | 4679 | if (!next_type || !btf_type_is_decl_tag_target(next_type)) { |
b5ea834d YS |
4680 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
4681 | return -EINVAL; | |
4682 | } | |
4683 | ||
4684 | if (!env_type_is_resolve_sink(env, next_type) && | |
4685 | !env_type_is_resolved(env, next_type_id)) | |
4686 | return env_stack_push(env, next_type, next_type_id); | |
4687 | ||
223f903e | 4688 | component_idx = btf_type_decl_tag(t)->component_idx; |
b5ea834d | 4689 | if (component_idx != -1) { |
bd16dee6 | 4690 | if (btf_type_is_var(next_type) || btf_type_is_typedef(next_type)) { |
b5ea834d YS |
4691 | btf_verifier_log_type(env, v->t, "Invalid component_idx"); |
4692 | return -EINVAL; | |
4693 | } | |
4694 | ||
4695 | if (btf_type_is_struct(next_type)) { | |
4696 | vlen = btf_type_vlen(next_type); | |
4697 | } else { | |
4698 | /* next_type should be a function */ | |
4699 | next_type = btf_type_by_id(btf, next_type->type); | |
4700 | vlen = btf_type_vlen(next_type); | |
4701 | } | |
4702 | ||
4703 | if ((u32)component_idx >= vlen) { | |
4704 | btf_verifier_log_type(env, v->t, "Invalid component_idx"); | |
4705 | return -EINVAL; | |
4706 | } | |
4707 | } | |
4708 | ||
4709 | env_stack_pop_resolved(env, next_type_id, 0); | |
4710 | ||
4711 | return 0; | |
4712 | } | |
4713 | ||
223f903e | 4714 | static void btf_decl_tag_log(struct btf_verifier_env *env, const struct btf_type *t) |
b5ea834d YS |
4715 | { |
4716 | btf_verifier_log(env, "type=%u component_idx=%d", t->type, | |
223f903e | 4717 | btf_type_decl_tag(t)->component_idx); |
b5ea834d YS |
4718 | } |
4719 | ||
223f903e YS |
4720 | static const struct btf_kind_operations decl_tag_ops = { |
4721 | .check_meta = btf_decl_tag_check_meta, | |
4722 | .resolve = btf_decl_tag_resolve, | |
b5ea834d YS |
4723 | .check_member = btf_df_check_member, |
4724 | .check_kflag_member = btf_df_check_kflag_member, | |
223f903e | 4725 | .log_details = btf_decl_tag_log, |
b5ea834d YS |
4726 | .show = btf_df_show, |
4727 | }; | |
4728 | ||
2667a262 MKL |
4729 | static int btf_func_proto_check(struct btf_verifier_env *env, |
4730 | const struct btf_type *t) | |
4731 | { | |
4732 | const struct btf_type *ret_type; | |
4733 | const struct btf_param *args; | |
4734 | const struct btf *btf; | |
4735 | u16 nr_args, i; | |
4736 | int err; | |
4737 | ||
4738 | btf = env->btf; | |
4739 | args = (const struct btf_param *)(t + 1); | |
4740 | nr_args = btf_type_vlen(t); | |
4741 | ||
4742 | /* Check func return type which could be "void" (t->type == 0) */ | |
4743 | if (t->type) { | |
4744 | u32 ret_type_id = t->type; | |
4745 | ||
4746 | ret_type = btf_type_by_id(btf, ret_type_id); | |
4747 | if (!ret_type) { | |
4748 | btf_verifier_log_type(env, t, "Invalid return type"); | |
4749 | return -EINVAL; | |
4750 | } | |
4751 | ||
ea68376c SF |
4752 | if (btf_type_is_resolve_source_only(ret_type)) { |
4753 | btf_verifier_log_type(env, t, "Invalid return type"); | |
4754 | return -EINVAL; | |
4755 | } | |
4756 | ||
2667a262 MKL |
4757 | if (btf_type_needs_resolve(ret_type) && |
4758 | !env_type_is_resolved(env, ret_type_id)) { | |
4759 | err = btf_resolve(env, ret_type, ret_type_id); | |
4760 | if (err) | |
4761 | return err; | |
4762 | } | |
4763 | ||
4764 | /* Ensure the return type is a type that has a size */ | |
4765 | if (!btf_type_id_size(btf, &ret_type_id, NULL)) { | |
4766 | btf_verifier_log_type(env, t, "Invalid return type"); | |
4767 | return -EINVAL; | |
4768 | } | |
4769 | } | |
4770 | ||
4771 | if (!nr_args) | |
4772 | return 0; | |
4773 | ||
4774 | /* Last func arg type_id could be 0 if it is a vararg */ | |
4775 | if (!args[nr_args - 1].type) { | |
4776 | if (args[nr_args - 1].name_off) { | |
4777 | btf_verifier_log_type(env, t, "Invalid arg#%u", | |
4778 | nr_args); | |
4779 | return -EINVAL; | |
4780 | } | |
4781 | nr_args--; | |
4782 | } | |
4783 | ||
2667a262 MKL |
4784 | for (i = 0; i < nr_args; i++) { |
4785 | const struct btf_type *arg_type; | |
4786 | u32 arg_type_id; | |
4787 | ||
4788 | arg_type_id = args[i].type; | |
4789 | arg_type = btf_type_by_id(btf, arg_type_id); | |
4790 | if (!arg_type) { | |
4791 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
5bad3587 | 4792 | return -EINVAL; |
2667a262 MKL |
4793 | } |
4794 | ||
f17472d4 SF |
4795 | if (btf_type_is_resolve_source_only(arg_type)) { |
4796 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
4797 | return -EINVAL; | |
4798 | } | |
4799 | ||
2667a262 MKL |
4800 | if (args[i].name_off && |
4801 | (!btf_name_offset_valid(btf, args[i].name_off) || | |
4802 | !btf_name_valid_identifier(btf, args[i].name_off))) { | |
4803 | btf_verifier_log_type(env, t, | |
4804 | "Invalid arg#%u", i + 1); | |
5bad3587 | 4805 | return -EINVAL; |
2667a262 MKL |
4806 | } |
4807 | ||
4808 | if (btf_type_needs_resolve(arg_type) && | |
4809 | !env_type_is_resolved(env, arg_type_id)) { | |
4810 | err = btf_resolve(env, arg_type, arg_type_id); | |
4811 | if (err) | |
5bad3587 | 4812 | return err; |
2667a262 MKL |
4813 | } |
4814 | ||
4815 | if (!btf_type_id_size(btf, &arg_type_id, NULL)) { | |
4816 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
5bad3587 | 4817 | return -EINVAL; |
2667a262 MKL |
4818 | } |
4819 | } | |
4820 | ||
5bad3587 | 4821 | return 0; |
2667a262 MKL |
4822 | } |
4823 | ||
4824 | static int btf_func_check(struct btf_verifier_env *env, | |
4825 | const struct btf_type *t) | |
4826 | { | |
4827 | const struct btf_type *proto_type; | |
4828 | const struct btf_param *args; | |
4829 | const struct btf *btf; | |
4830 | u16 nr_args, i; | |
4831 | ||
4832 | btf = env->btf; | |
4833 | proto_type = btf_type_by_id(btf, t->type); | |
4834 | ||
4835 | if (!proto_type || !btf_type_is_func_proto(proto_type)) { | |
4836 | btf_verifier_log_type(env, t, "Invalid type_id"); | |
4837 | return -EINVAL; | |
4838 | } | |
4839 | ||
4840 | args = (const struct btf_param *)(proto_type + 1); | |
4841 | nr_args = btf_type_vlen(proto_type); | |
4842 | for (i = 0; i < nr_args; i++) { | |
4843 | if (!args[i].name_off && args[i].type) { | |
4844 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
4845 | return -EINVAL; | |
4846 | } | |
4847 | } | |
4848 | ||
4849 | return 0; | |
4850 | } | |
4851 | ||
69b693f0 MKL |
4852 | static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = { |
4853 | [BTF_KIND_INT] = &int_ops, | |
4854 | [BTF_KIND_PTR] = &ptr_ops, | |
4855 | [BTF_KIND_ARRAY] = &array_ops, | |
4856 | [BTF_KIND_STRUCT] = &struct_ops, | |
4857 | [BTF_KIND_UNION] = &struct_ops, | |
4858 | [BTF_KIND_ENUM] = &enum_ops, | |
4859 | [BTF_KIND_FWD] = &fwd_ops, | |
4860 | [BTF_KIND_TYPEDEF] = &modifier_ops, | |
4861 | [BTF_KIND_VOLATILE] = &modifier_ops, | |
4862 | [BTF_KIND_CONST] = &modifier_ops, | |
4863 | [BTF_KIND_RESTRICT] = &modifier_ops, | |
2667a262 MKL |
4864 | [BTF_KIND_FUNC] = &func_ops, |
4865 | [BTF_KIND_FUNC_PROTO] = &func_proto_ops, | |
1dc92851 DB |
4866 | [BTF_KIND_VAR] = &var_ops, |
4867 | [BTF_KIND_DATASEC] = &datasec_ops, | |
b1828f0b | 4868 | [BTF_KIND_FLOAT] = &float_ops, |
223f903e | 4869 | [BTF_KIND_DECL_TAG] = &decl_tag_ops, |
8c42d2fa | 4870 | [BTF_KIND_TYPE_TAG] = &modifier_ops, |
6089fb32 | 4871 | [BTF_KIND_ENUM64] = &enum64_ops, |
69b693f0 MKL |
4872 | }; |
4873 | ||
4874 | static s32 btf_check_meta(struct btf_verifier_env *env, | |
4875 | const struct btf_type *t, | |
4876 | u32 meta_left) | |
4877 | { | |
4878 | u32 saved_meta_left = meta_left; | |
4879 | s32 var_meta_size; | |
4880 | ||
4881 | if (meta_left < sizeof(*t)) { | |
4882 | btf_verifier_log(env, "[%u] meta_left:%u meta_needed:%zu", | |
4883 | env->log_type_id, meta_left, sizeof(*t)); | |
4884 | return -EINVAL; | |
4885 | } | |
4886 | meta_left -= sizeof(*t); | |
4887 | ||
aea2f7b8 MKL |
4888 | if (t->info & ~BTF_INFO_MASK) { |
4889 | btf_verifier_log(env, "[%u] Invalid btf_info:%x", | |
4890 | env->log_type_id, t->info); | |
4891 | return -EINVAL; | |
4892 | } | |
4893 | ||
69b693f0 MKL |
4894 | if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX || |
4895 | BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) { | |
4896 | btf_verifier_log(env, "[%u] Invalid kind:%u", | |
4897 | env->log_type_id, BTF_INFO_KIND(t->info)); | |
4898 | return -EINVAL; | |
4899 | } | |
4900 | ||
fbcf93eb | 4901 | if (!btf_name_offset_valid(env->btf, t->name_off)) { |
69b693f0 | 4902 | btf_verifier_log(env, "[%u] Invalid name_offset:%u", |
fbcf93eb | 4903 | env->log_type_id, t->name_off); |
69b693f0 MKL |
4904 | return -EINVAL; |
4905 | } | |
4906 | ||
4907 | var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left); | |
4908 | if (var_meta_size < 0) | |
4909 | return var_meta_size; | |
4910 | ||
4911 | meta_left -= var_meta_size; | |
4912 | ||
4913 | return saved_meta_left - meta_left; | |
4914 | } | |
4915 | ||
4916 | static int btf_check_all_metas(struct btf_verifier_env *env) | |
4917 | { | |
4918 | struct btf *btf = env->btf; | |
4919 | struct btf_header *hdr; | |
4920 | void *cur, *end; | |
4921 | ||
f80442a4 | 4922 | hdr = &btf->hdr; |
69b693f0 | 4923 | cur = btf->nohdr_data + hdr->type_off; |
4b1c5d91 | 4924 | end = cur + hdr->type_len; |
69b693f0 | 4925 | |
951bb646 | 4926 | env->log_type_id = btf->base_btf ? btf->start_id : 1; |
69b693f0 MKL |
4927 | while (cur < end) { |
4928 | struct btf_type *t = cur; | |
4929 | s32 meta_size; | |
4930 | ||
4931 | meta_size = btf_check_meta(env, t, end - cur); | |
4932 | if (meta_size < 0) | |
4933 | return meta_size; | |
4934 | ||
4935 | btf_add_type(env, t); | |
4936 | cur += meta_size; | |
4937 | env->log_type_id++; | |
4938 | } | |
4939 | ||
4940 | return 0; | |
4941 | } | |
4942 | ||
eb3f595d MKL |
4943 | static bool btf_resolve_valid(struct btf_verifier_env *env, |
4944 | const struct btf_type *t, | |
4945 | u32 type_id) | |
4946 | { | |
4947 | struct btf *btf = env->btf; | |
4948 | ||
4949 | if (!env_type_is_resolved(env, type_id)) | |
4950 | return false; | |
4951 | ||
1dc92851 | 4952 | if (btf_type_is_struct(t) || btf_type_is_datasec(t)) |
951bb646 AN |
4953 | return !btf_resolved_type_id(btf, type_id) && |
4954 | !btf_resolved_type_size(btf, type_id); | |
eb3f595d | 4955 | |
d7e7b42f | 4956 | if (btf_type_is_decl_tag(t) || btf_type_is_func(t)) |
b5ea834d YS |
4957 | return btf_resolved_type_id(btf, type_id) && |
4958 | !btf_resolved_type_size(btf, type_id); | |
4959 | ||
1dc92851 DB |
4960 | if (btf_type_is_modifier(t) || btf_type_is_ptr(t) || |
4961 | btf_type_is_var(t)) { | |
eb3f595d | 4962 | t = btf_type_id_resolve(btf, &type_id); |
1dc92851 DB |
4963 | return t && |
4964 | !btf_type_is_modifier(t) && | |
4965 | !btf_type_is_var(t) && | |
4966 | !btf_type_is_datasec(t); | |
eb3f595d MKL |
4967 | } |
4968 | ||
4969 | if (btf_type_is_array(t)) { | |
4970 | const struct btf_array *array = btf_type_array(t); | |
4971 | const struct btf_type *elem_type; | |
4972 | u32 elem_type_id = array->type; | |
4973 | u32 elem_size; | |
4974 | ||
4975 | elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); | |
4976 | return elem_type && !btf_type_is_modifier(elem_type) && | |
4977 | (array->nelems * elem_size == | |
951bb646 | 4978 | btf_resolved_type_size(btf, type_id)); |
eb3f595d MKL |
4979 | } |
4980 | ||
4981 | return false; | |
4982 | } | |
4983 | ||
2667a262 MKL |
4984 | static int btf_resolve(struct btf_verifier_env *env, |
4985 | const struct btf_type *t, u32 type_id) | |
4986 | { | |
4987 | u32 save_log_type_id = env->log_type_id; | |
4988 | const struct resolve_vertex *v; | |
4989 | int err = 0; | |
4990 | ||
4991 | env->resolve_mode = RESOLVE_TBD; | |
4992 | env_stack_push(env, t, type_id); | |
4993 | while (!err && (v = env_stack_peak(env))) { | |
4994 | env->log_type_id = v->type_id; | |
4995 | err = btf_type_ops(v->t)->resolve(env, v); | |
4996 | } | |
4997 | ||
4998 | env->log_type_id = type_id; | |
4999 | if (err == -E2BIG) { | |
5000 | btf_verifier_log_type(env, t, | |
5001 | "Exceeded max resolving depth:%u", | |
5002 | MAX_RESOLVE_DEPTH); | |
5003 | } else if (err == -EEXIST) { | |
5004 | btf_verifier_log_type(env, t, "Loop detected"); | |
5005 | } | |
5006 | ||
5007 | /* Final sanity check */ | |
5008 | if (!err && !btf_resolve_valid(env, t, type_id)) { | |
5009 | btf_verifier_log_type(env, t, "Invalid resolve state"); | |
5010 | err = -EINVAL; | |
5011 | } | |
5012 | ||
5013 | env->log_type_id = save_log_type_id; | |
5014 | return err; | |
5015 | } | |
5016 | ||
eb3f595d MKL |
5017 | static int btf_check_all_types(struct btf_verifier_env *env) |
5018 | { | |
5019 | struct btf *btf = env->btf; | |
951bb646 AN |
5020 | const struct btf_type *t; |
5021 | u32 type_id, i; | |
eb3f595d MKL |
5022 | int err; |
5023 | ||
5024 | err = env_resolve_init(env); | |
5025 | if (err) | |
5026 | return err; | |
5027 | ||
5028 | env->phase++; | |
951bb646 AN |
5029 | for (i = btf->base_btf ? 0 : 1; i < btf->nr_types; i++) { |
5030 | type_id = btf->start_id + i; | |
5031 | t = btf_type_by_id(btf, type_id); | |
eb3f595d MKL |
5032 | |
5033 | env->log_type_id = type_id; | |
5034 | if (btf_type_needs_resolve(t) && | |
5035 | !env_type_is_resolved(env, type_id)) { | |
5036 | err = btf_resolve(env, t, type_id); | |
5037 | if (err) | |
5038 | return err; | |
5039 | } | |
5040 | ||
2667a262 MKL |
5041 | if (btf_type_is_func_proto(t)) { |
5042 | err = btf_func_proto_check(env, t); | |
5043 | if (err) | |
5044 | return err; | |
5045 | } | |
eb3f595d MKL |
5046 | } |
5047 | ||
5048 | return 0; | |
5049 | } | |
5050 | ||
69b693f0 MKL |
5051 | static int btf_parse_type_sec(struct btf_verifier_env *env) |
5052 | { | |
f80442a4 | 5053 | const struct btf_header *hdr = &env->btf->hdr; |
eb3f595d MKL |
5054 | int err; |
5055 | ||
f80442a4 MKL |
5056 | /* Type section must align to 4 bytes */ |
5057 | if (hdr->type_off & (sizeof(u32) - 1)) { | |
5058 | btf_verifier_log(env, "Unaligned type_off"); | |
5059 | return -EINVAL; | |
5060 | } | |
5061 | ||
951bb646 | 5062 | if (!env->btf->base_btf && !hdr->type_len) { |
f80442a4 MKL |
5063 | btf_verifier_log(env, "No type found"); |
5064 | return -EINVAL; | |
5065 | } | |
5066 | ||
eb3f595d MKL |
5067 | err = btf_check_all_metas(env); |
5068 | if (err) | |
5069 | return err; | |
5070 | ||
5071 | return btf_check_all_types(env); | |
69b693f0 MKL |
5072 | } |
5073 | ||
5074 | static int btf_parse_str_sec(struct btf_verifier_env *env) | |
5075 | { | |
5076 | const struct btf_header *hdr; | |
5077 | struct btf *btf = env->btf; | |
5078 | const char *start, *end; | |
5079 | ||
f80442a4 | 5080 | hdr = &btf->hdr; |
69b693f0 MKL |
5081 | start = btf->nohdr_data + hdr->str_off; |
5082 | end = start + hdr->str_len; | |
5083 | ||
f80442a4 MKL |
5084 | if (end != btf->data + btf->data_size) { |
5085 | btf_verifier_log(env, "String section is not at the end"); | |
5086 | return -EINVAL; | |
5087 | } | |
5088 | ||
951bb646 AN |
5089 | btf->strings = start; |
5090 | ||
5091 | if (btf->base_btf && !hdr->str_len) | |
5092 | return 0; | |
5093 | if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET || end[-1]) { | |
5094 | btf_verifier_log(env, "Invalid string section"); | |
5095 | return -EINVAL; | |
5096 | } | |
5097 | if (!btf->base_btf && start[0]) { | |
69b693f0 MKL |
5098 | btf_verifier_log(env, "Invalid string section"); |
5099 | return -EINVAL; | |
5100 | } | |
69b693f0 MKL |
5101 | |
5102 | return 0; | |
5103 | } | |
5104 | ||
f80442a4 MKL |
5105 | static const size_t btf_sec_info_offset[] = { |
5106 | offsetof(struct btf_header, type_off), | |
5107 | offsetof(struct btf_header, str_off), | |
5108 | }; | |
5109 | ||
5110 | static int btf_sec_info_cmp(const void *a, const void *b) | |
69b693f0 | 5111 | { |
f80442a4 MKL |
5112 | const struct btf_sec_info *x = a; |
5113 | const struct btf_sec_info *y = b; | |
5114 | ||
5115 | return (int)(x->off - y->off) ? : (int)(x->len - y->len); | |
5116 | } | |
5117 | ||
5118 | static int btf_check_sec_info(struct btf_verifier_env *env, | |
5119 | u32 btf_data_size) | |
5120 | { | |
a2889a4c | 5121 | struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)]; |
f80442a4 | 5122 | u32 total, expected_total, i; |
69b693f0 | 5123 | const struct btf_header *hdr; |
f80442a4 MKL |
5124 | const struct btf *btf; |
5125 | ||
5126 | btf = env->btf; | |
5127 | hdr = &btf->hdr; | |
5128 | ||
5129 | /* Populate the secs from hdr */ | |
a2889a4c | 5130 | for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) |
f80442a4 MKL |
5131 | secs[i] = *(struct btf_sec_info *)((void *)hdr + |
5132 | btf_sec_info_offset[i]); | |
5133 | ||
a2889a4c MKL |
5134 | sort(secs, ARRAY_SIZE(btf_sec_info_offset), |
5135 | sizeof(struct btf_sec_info), btf_sec_info_cmp, NULL); | |
f80442a4 MKL |
5136 | |
5137 | /* Check for gaps and overlap among sections */ | |
5138 | total = 0; | |
5139 | expected_total = btf_data_size - hdr->hdr_len; | |
a2889a4c | 5140 | for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) { |
f80442a4 MKL |
5141 | if (expected_total < secs[i].off) { |
5142 | btf_verifier_log(env, "Invalid section offset"); | |
5143 | return -EINVAL; | |
5144 | } | |
5145 | if (total < secs[i].off) { | |
5146 | /* gap */ | |
5147 | btf_verifier_log(env, "Unsupported section found"); | |
5148 | return -EINVAL; | |
5149 | } | |
5150 | if (total > secs[i].off) { | |
5151 | btf_verifier_log(env, "Section overlap found"); | |
5152 | return -EINVAL; | |
5153 | } | |
5154 | if (expected_total - total < secs[i].len) { | |
5155 | btf_verifier_log(env, | |
5156 | "Total section length too long"); | |
5157 | return -EINVAL; | |
5158 | } | |
5159 | total += secs[i].len; | |
5160 | } | |
5161 | ||
5162 | /* There is data other than hdr and known sections */ | |
5163 | if (expected_total != total) { | |
5164 | btf_verifier_log(env, "Unsupported section found"); | |
5165 | return -EINVAL; | |
5166 | } | |
5167 | ||
5168 | return 0; | |
5169 | } | |
5170 | ||
4a6998af | 5171 | static int btf_parse_hdr(struct btf_verifier_env *env) |
f80442a4 | 5172 | { |
4a6998af | 5173 | u32 hdr_len, hdr_copy, btf_data_size; |
f80442a4 | 5174 | const struct btf_header *hdr; |
f80442a4 | 5175 | struct btf *btf; |
69b693f0 | 5176 | |
f80442a4 | 5177 | btf = env->btf; |
4a6998af | 5178 | btf_data_size = btf->data_size; |
f80442a4 | 5179 | |
583669ab | 5180 | if (btf_data_size < offsetofend(struct btf_header, hdr_len)) { |
f80442a4 MKL |
5181 | btf_verifier_log(env, "hdr_len not found"); |
5182 | return -EINVAL; | |
5183 | } | |
5184 | ||
4a6998af ML |
5185 | hdr = btf->data; |
5186 | hdr_len = hdr->hdr_len; | |
f80442a4 | 5187 | if (btf_data_size < hdr_len) { |
69b693f0 MKL |
5188 | btf_verifier_log(env, "btf_header not found"); |
5189 | return -EINVAL; | |
5190 | } | |
5191 | ||
4a6998af ML |
5192 | /* Ensure the unsupported header fields are zero */ |
5193 | if (hdr_len > sizeof(btf->hdr)) { | |
5194 | u8 *expected_zero = btf->data + sizeof(btf->hdr); | |
5195 | u8 *end = btf->data + hdr_len; | |
5196 | ||
5197 | for (; expected_zero < end; expected_zero++) { | |
5198 | if (*expected_zero) { | |
5199 | btf_verifier_log(env, "Unsupported btf_header"); | |
5200 | return -E2BIG; | |
5201 | } | |
5202 | } | |
f80442a4 MKL |
5203 | } |
5204 | ||
5205 | hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr)); | |
4a6998af | 5206 | memcpy(&btf->hdr, btf->data, hdr_copy); |
f80442a4 MKL |
5207 | |
5208 | hdr = &btf->hdr; | |
5209 | ||
5210 | btf_verifier_log_hdr(env, btf_data_size); | |
69b693f0 | 5211 | |
69b693f0 MKL |
5212 | if (hdr->magic != BTF_MAGIC) { |
5213 | btf_verifier_log(env, "Invalid magic"); | |
5214 | return -EINVAL; | |
5215 | } | |
5216 | ||
5217 | if (hdr->version != BTF_VERSION) { | |
5218 | btf_verifier_log(env, "Unsupported version"); | |
5219 | return -ENOTSUPP; | |
5220 | } | |
5221 | ||
5222 | if (hdr->flags) { | |
5223 | btf_verifier_log(env, "Unsupported flags"); | |
5224 | return -ENOTSUPP; | |
5225 | } | |
5226 | ||
bcc5e616 | 5227 | if (!btf->base_btf && btf_data_size == hdr->hdr_len) { |
69b693f0 MKL |
5228 | btf_verifier_log(env, "No data"); |
5229 | return -EINVAL; | |
5230 | } | |
5231 | ||
3a74904c | 5232 | return btf_check_sec_info(env, btf_data_size); |
69b693f0 MKL |
5233 | } |
5234 | ||
8ffa5cc1 KKD |
5235 | static const char *alloc_obj_fields[] = { |
5236 | "bpf_spin_lock", | |
5237 | "bpf_list_head", | |
5238 | "bpf_list_node", | |
5239 | }; | |
5240 | ||
5241 | static struct btf_struct_metas * | |
5242 | btf_parse_struct_metas(struct bpf_verifier_log *log, struct btf *btf) | |
5243 | { | |
5244 | union { | |
5245 | struct btf_id_set set; | |
5246 | struct { | |
5247 | u32 _cnt; | |
5248 | u32 _ids[ARRAY_SIZE(alloc_obj_fields)]; | |
5249 | } _arr; | |
5250 | } aof; | |
5251 | struct btf_struct_metas *tab = NULL; | |
5252 | int i, n, id, ret; | |
5253 | ||
5254 | BUILD_BUG_ON(offsetof(struct btf_id_set, cnt) != 0); | |
5255 | BUILD_BUG_ON(sizeof(struct btf_id_set) != sizeof(u32)); | |
5256 | ||
5257 | memset(&aof, 0, sizeof(aof)); | |
5258 | for (i = 0; i < ARRAY_SIZE(alloc_obj_fields); i++) { | |
5259 | /* Try to find whether this special type exists in user BTF, and | |
5260 | * if so remember its ID so we can easily find it among members | |
5261 | * of structs that we iterate in the next loop. | |
5262 | */ | |
5263 | id = btf_find_by_name_kind(btf, alloc_obj_fields[i], BTF_KIND_STRUCT); | |
5264 | if (id < 0) | |
5265 | continue; | |
5266 | aof.set.ids[aof.set.cnt++] = id; | |
5267 | } | |
5268 | ||
5269 | if (!aof.set.cnt) | |
5270 | return NULL; | |
5271 | sort(&aof.set.ids, aof.set.cnt, sizeof(aof.set.ids[0]), btf_id_cmp_func, NULL); | |
5272 | ||
5273 | n = btf_nr_types(btf); | |
5274 | for (i = 1; i < n; i++) { | |
5275 | struct btf_struct_metas *new_tab; | |
5276 | const struct btf_member *member; | |
5277 | struct btf_field_offs *foffs; | |
5278 | struct btf_struct_meta *type; | |
5279 | struct btf_record *record; | |
5280 | const struct btf_type *t; | |
5281 | int j, tab_cnt; | |
5282 | ||
5283 | t = btf_type_by_id(btf, i); | |
5284 | if (!t) { | |
5285 | ret = -EINVAL; | |
5286 | goto free; | |
5287 | } | |
5288 | if (!__btf_type_is_struct(t)) | |
5289 | continue; | |
5290 | ||
5291 | cond_resched(); | |
5292 | ||
5293 | for_each_member(j, t, member) { | |
5294 | if (btf_id_set_contains(&aof.set, member->type)) | |
5295 | goto parse; | |
5296 | } | |
5297 | continue; | |
5298 | parse: | |
5299 | tab_cnt = tab ? tab->cnt : 0; | |
5300 | new_tab = krealloc(tab, offsetof(struct btf_struct_metas, types[tab_cnt + 1]), | |
5301 | GFP_KERNEL | __GFP_NOWARN); | |
5302 | if (!new_tab) { | |
5303 | ret = -ENOMEM; | |
5304 | goto free; | |
5305 | } | |
5306 | if (!tab) | |
5307 | new_tab->cnt = 0; | |
5308 | tab = new_tab; | |
5309 | ||
5310 | type = &tab->types[tab->cnt]; | |
5311 | type->btf_id = i; | |
5312 | record = btf_parse_fields(btf, t, BPF_SPIN_LOCK | BPF_LIST_HEAD | BPF_LIST_NODE, t->size); | |
5313 | /* The record cannot be unset, treat it as an error if so */ | |
5314 | if (IS_ERR_OR_NULL(record)) { | |
5315 | ret = PTR_ERR_OR_ZERO(record) ?: -EFAULT; | |
5316 | goto free; | |
5317 | } | |
5318 | foffs = btf_parse_field_offs(record); | |
5319 | /* We need the field_offs to be valid for a valid record, | |
5320 | * either both should be set or both should be unset. | |
5321 | */ | |
5322 | if (IS_ERR_OR_NULL(foffs)) { | |
5323 | btf_record_free(record); | |
5324 | ret = -EFAULT; | |
5325 | goto free; | |
5326 | } | |
5327 | type->record = record; | |
5328 | type->field_offs = foffs; | |
5329 | tab->cnt++; | |
5330 | } | |
5331 | return tab; | |
5332 | free: | |
5333 | btf_struct_metas_free(tab); | |
5334 | return ERR_PTR(ret); | |
5335 | } | |
5336 | ||
5337 | struct btf_struct_meta *btf_find_struct_meta(const struct btf *btf, u32 btf_id) | |
5338 | { | |
5339 | struct btf_struct_metas *tab; | |
5340 | ||
5341 | BUILD_BUG_ON(offsetof(struct btf_struct_meta, btf_id) != 0); | |
5342 | tab = btf->struct_meta_tab; | |
5343 | if (!tab) | |
5344 | return NULL; | |
5345 | return bsearch(&btf_id, tab->types, tab->cnt, sizeof(tab->types[0]), btf_id_cmp_func); | |
5346 | } | |
5347 | ||
eb596b09 KKD |
5348 | static int btf_check_type_tags(struct btf_verifier_env *env, |
5349 | struct btf *btf, int start_id) | |
5350 | { | |
5351 | int i, n, good_id = start_id - 1; | |
5352 | bool in_tags; | |
5353 | ||
5354 | n = btf_nr_types(btf); | |
5355 | for (i = start_id; i < n; i++) { | |
5356 | const struct btf_type *t; | |
d1a374a1 | 5357 | int chain_limit = 32; |
eb596b09 KKD |
5358 | u32 cur_id = i; |
5359 | ||
5360 | t = btf_type_by_id(btf, i); | |
5361 | if (!t) | |
5362 | return -EINVAL; | |
5363 | if (!btf_type_is_modifier(t)) | |
5364 | continue; | |
5365 | ||
5366 | cond_resched(); | |
5367 | ||
5368 | in_tags = btf_type_is_type_tag(t); | |
5369 | while (btf_type_is_modifier(t)) { | |
d1a374a1 KKD |
5370 | if (!chain_limit--) { |
5371 | btf_verifier_log(env, "Max chain length or cycle detected"); | |
5372 | return -ELOOP; | |
5373 | } | |
eb596b09 KKD |
5374 | if (btf_type_is_type_tag(t)) { |
5375 | if (!in_tags) { | |
5376 | btf_verifier_log(env, "Type tags don't precede modifiers"); | |
5377 | return -EINVAL; | |
5378 | } | |
5379 | } else if (in_tags) { | |
5380 | in_tags = false; | |
5381 | } | |
5382 | if (cur_id <= good_id) | |
5383 | break; | |
5384 | /* Move to next type */ | |
5385 | cur_id = t->type; | |
5386 | t = btf_type_by_id(btf, cur_id); | |
5387 | if (!t) | |
5388 | return -EINVAL; | |
5389 | } | |
5390 | good_id = i; | |
5391 | } | |
5392 | return 0; | |
5393 | } | |
5394 | ||
c571bd75 | 5395 | static struct btf *btf_parse(bpfptr_t btf_data, u32 btf_data_size, |
69b693f0 MKL |
5396 | u32 log_level, char __user *log_ubuf, u32 log_size) |
5397 | { | |
8ffa5cc1 | 5398 | struct btf_struct_metas *struct_meta_tab; |
69b693f0 MKL |
5399 | struct btf_verifier_env *env = NULL; |
5400 | struct bpf_verifier_log *log; | |
5401 | struct btf *btf = NULL; | |
5402 | u8 *data; | |
5403 | int err; | |
5404 | ||
5405 | if (btf_data_size > BTF_MAX_SIZE) | |
5406 | return ERR_PTR(-E2BIG); | |
5407 | ||
5408 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
5409 | if (!env) | |
5410 | return ERR_PTR(-ENOMEM); | |
5411 | ||
5412 | log = &env->log; | |
5413 | if (log_level || log_ubuf || log_size) { | |
5414 | /* user requested verbose verifier output | |
5415 | * and supplied buffer to store the verification trace | |
5416 | */ | |
5417 | log->level = log_level; | |
5418 | log->ubuf = log_ubuf; | |
5419 | log->len_total = log_size; | |
5420 | ||
5421 | /* log attributes have to be sane */ | |
866de407 | 5422 | if (!bpf_verifier_log_attr_valid(log)) { |
69b693f0 MKL |
5423 | err = -EINVAL; |
5424 | goto errout; | |
5425 | } | |
5426 | } | |
5427 | ||
5428 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
5429 | if (!btf) { | |
5430 | err = -ENOMEM; | |
5431 | goto errout; | |
5432 | } | |
f80442a4 MKL |
5433 | env->btf = btf; |
5434 | ||
69b693f0 MKL |
5435 | data = kvmalloc(btf_data_size, GFP_KERNEL | __GFP_NOWARN); |
5436 | if (!data) { | |
5437 | err = -ENOMEM; | |
5438 | goto errout; | |
5439 | } | |
5440 | ||
5441 | btf->data = data; | |
5442 | btf->data_size = btf_data_size; | |
5443 | ||
c571bd75 | 5444 | if (copy_from_bpfptr(data, btf_data, btf_data_size)) { |
69b693f0 MKL |
5445 | err = -EFAULT; |
5446 | goto errout; | |
5447 | } | |
5448 | ||
4a6998af ML |
5449 | err = btf_parse_hdr(env); |
5450 | if (err) | |
5451 | goto errout; | |
5452 | ||
5453 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
5454 | ||
69b693f0 MKL |
5455 | err = btf_parse_str_sec(env); |
5456 | if (err) | |
5457 | goto errout; | |
5458 | ||
5459 | err = btf_parse_type_sec(env); | |
5460 | if (err) | |
5461 | goto errout; | |
5462 | ||
eb596b09 KKD |
5463 | err = btf_check_type_tags(env, btf, 1); |
5464 | if (err) | |
5465 | goto errout; | |
5466 | ||
8ffa5cc1 KKD |
5467 | struct_meta_tab = btf_parse_struct_metas(log, btf); |
5468 | if (IS_ERR(struct_meta_tab)) { | |
5469 | err = PTR_ERR(struct_meta_tab); | |
5470 | goto errout; | |
5471 | } | |
5472 | btf->struct_meta_tab = struct_meta_tab; | |
5473 | ||
865ce09a KKD |
5474 | if (struct_meta_tab) { |
5475 | int i; | |
5476 | ||
5477 | for (i = 0; i < struct_meta_tab->cnt; i++) { | |
5478 | err = btf_check_and_fixup_fields(btf, struct_meta_tab->types[i].record); | |
5479 | if (err < 0) | |
5480 | goto errout_meta; | |
5481 | } | |
5482 | } | |
5483 | ||
f80442a4 | 5484 | if (log->level && bpf_verifier_log_full(log)) { |
69b693f0 | 5485 | err = -ENOSPC; |
8ffa5cc1 | 5486 | goto errout_meta; |
69b693f0 MKL |
5487 | } |
5488 | ||
f80442a4 MKL |
5489 | btf_verifier_env_free(env); |
5490 | refcount_set(&btf->refcnt, 1); | |
5491 | return btf; | |
69b693f0 | 5492 | |
8ffa5cc1 KKD |
5493 | errout_meta: |
5494 | btf_free_struct_meta_tab(btf); | |
69b693f0 MKL |
5495 | errout: |
5496 | btf_verifier_env_free(env); | |
5497 | if (btf) | |
5498 | btf_free(btf); | |
5499 | return ERR_PTR(err); | |
5500 | } | |
b00b8dae | 5501 | |
90ceddcb FS |
5502 | extern char __weak __start_BTF[]; |
5503 | extern char __weak __stop_BTF[]; | |
91cc1a99 AS |
5504 | extern struct btf *btf_vmlinux; |
5505 | ||
5506 | #define BPF_MAP_TYPE(_id, _ops) | |
f2e10bff | 5507 | #define BPF_LINK_TYPE(_id, _name) |
91cc1a99 AS |
5508 | static union { |
5509 | struct bpf_ctx_convert { | |
5510 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
5511 | prog_ctx_type _id##_prog; \ | |
5512 | kern_ctx_type _id##_kern; | |
5513 | #include <linux/bpf_types.h> | |
5514 | #undef BPF_PROG_TYPE | |
5515 | } *__t; | |
5516 | /* 't' is written once under lock. Read many times. */ | |
5517 | const struct btf_type *t; | |
5518 | } bpf_ctx_convert; | |
5519 | enum { | |
5520 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
5521 | __ctx_convert##_id, | |
5522 | #include <linux/bpf_types.h> | |
5523 | #undef BPF_PROG_TYPE | |
ce27709b | 5524 | __ctx_convert_unused, /* to avoid empty enum in extreme .config */ |
91cc1a99 AS |
5525 | }; |
5526 | static u8 bpf_ctx_convert_map[] = { | |
5527 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
5528 | [_id] = __ctx_convert##_id, | |
5529 | #include <linux/bpf_types.h> | |
5530 | #undef BPF_PROG_TYPE | |
4c80c7bc | 5531 | 0, /* avoid empty array */ |
91cc1a99 AS |
5532 | }; |
5533 | #undef BPF_MAP_TYPE | |
f2e10bff | 5534 | #undef BPF_LINK_TYPE |
91cc1a99 | 5535 | |
00b85860 | 5536 | const struct btf_member * |
34747c41 | 5537 | btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf, |
51c39bb1 AS |
5538 | const struct btf_type *t, enum bpf_prog_type prog_type, |
5539 | int arg) | |
91cc1a99 AS |
5540 | { |
5541 | const struct btf_type *conv_struct; | |
5542 | const struct btf_type *ctx_struct; | |
5543 | const struct btf_member *ctx_type; | |
5544 | const char *tname, *ctx_tname; | |
5545 | ||
5546 | conv_struct = bpf_ctx_convert.t; | |
5547 | if (!conv_struct) { | |
5548 | bpf_log(log, "btf_vmlinux is malformed\n"); | |
5549 | return NULL; | |
5550 | } | |
5551 | t = btf_type_by_id(btf, t->type); | |
5552 | while (btf_type_is_modifier(t)) | |
5553 | t = btf_type_by_id(btf, t->type); | |
5554 | if (!btf_type_is_struct(t)) { | |
5555 | /* Only pointer to struct is supported for now. | |
5556 | * That means that BPF_PROG_TYPE_TRACEPOINT with BTF | |
5557 | * is not supported yet. | |
5558 | * BPF_PROG_TYPE_RAW_TRACEPOINT is fine. | |
5559 | */ | |
91cc1a99 AS |
5560 | return NULL; |
5561 | } | |
5562 | tname = btf_name_by_offset(btf, t->name_off); | |
5563 | if (!tname) { | |
51c39bb1 | 5564 | bpf_log(log, "arg#%d struct doesn't have a name\n", arg); |
91cc1a99 AS |
5565 | return NULL; |
5566 | } | |
5567 | /* prog_type is valid bpf program type. No need for bounds check. */ | |
5568 | ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2; | |
5569 | /* ctx_struct is a pointer to prog_ctx_type in vmlinux. | |
5570 | * Like 'struct __sk_buff' | |
5571 | */ | |
5572 | ctx_struct = btf_type_by_id(btf_vmlinux, ctx_type->type); | |
5573 | if (!ctx_struct) | |
5574 | /* should not happen */ | |
5575 | return NULL; | |
5576 | ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_struct->name_off); | |
5577 | if (!ctx_tname) { | |
5578 | /* should not happen */ | |
5579 | bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n"); | |
5580 | return NULL; | |
5581 | } | |
5582 | /* only compare that prog's ctx type name is the same as | |
5583 | * kernel expects. No need to compare field by field. | |
5584 | * It's ok for bpf prog to do: | |
5585 | * struct __sk_buff {}; | |
5586 | * int socket_filter_bpf_prog(struct __sk_buff *skb) | |
5587 | * { // no fields of skb are ever used } | |
5588 | */ | |
5589 | if (strcmp(ctx_tname, tname)) | |
5590 | return NULL; | |
5591 | return ctx_type; | |
5592 | } | |
8580ac94 | 5593 | |
5b92a28a AS |
5594 | static int btf_translate_to_vmlinux(struct bpf_verifier_log *log, |
5595 | struct btf *btf, | |
5596 | const struct btf_type *t, | |
51c39bb1 AS |
5597 | enum bpf_prog_type prog_type, |
5598 | int arg) | |
5b92a28a AS |
5599 | { |
5600 | const struct btf_member *prog_ctx_type, *kern_ctx_type; | |
5601 | ||
51c39bb1 | 5602 | prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type, arg); |
5b92a28a AS |
5603 | if (!prog_ctx_type) |
5604 | return -ENOENT; | |
5605 | kern_ctx_type = prog_ctx_type + 1; | |
5606 | return kern_ctx_type->type; | |
5607 | } | |
5608 | ||
fd264ca0 YS |
5609 | int get_kern_ctx_btf_id(struct bpf_verifier_log *log, enum bpf_prog_type prog_type) |
5610 | { | |
5611 | const struct btf_member *kctx_member; | |
5612 | const struct btf_type *conv_struct; | |
5613 | const struct btf_type *kctx_type; | |
5614 | u32 kctx_type_id; | |
5615 | ||
5616 | conv_struct = bpf_ctx_convert.t; | |
5617 | /* get member for kernel ctx type */ | |
5618 | kctx_member = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2 + 1; | |
5619 | kctx_type_id = kctx_member->type; | |
5620 | kctx_type = btf_type_by_id(btf_vmlinux, kctx_type_id); | |
5621 | if (!btf_type_is_struct(kctx_type)) { | |
5622 | bpf_log(log, "kern ctx type id %u is not a struct\n", kctx_type_id); | |
5623 | return -EINVAL; | |
5624 | } | |
5625 | ||
5626 | return kctx_type_id; | |
5627 | } | |
5628 | ||
49f4e672 JO |
5629 | BTF_ID_LIST(bpf_ctx_convert_btf_id) |
5630 | BTF_ID(struct, bpf_ctx_convert) | |
5631 | ||
8580ac94 AS |
5632 | struct btf *btf_parse_vmlinux(void) |
5633 | { | |
5634 | struct btf_verifier_env *env = NULL; | |
5635 | struct bpf_verifier_log *log; | |
5636 | struct btf *btf = NULL; | |
49f4e672 | 5637 | int err; |
8580ac94 AS |
5638 | |
5639 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
5640 | if (!env) | |
5641 | return ERR_PTR(-ENOMEM); | |
5642 | ||
5643 | log = &env->log; | |
5644 | log->level = BPF_LOG_KERNEL; | |
5645 | ||
5646 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
5647 | if (!btf) { | |
5648 | err = -ENOMEM; | |
5649 | goto errout; | |
5650 | } | |
5651 | env->btf = btf; | |
5652 | ||
90ceddcb FS |
5653 | btf->data = __start_BTF; |
5654 | btf->data_size = __stop_BTF - __start_BTF; | |
53297220 AN |
5655 | btf->kernel_btf = true; |
5656 | snprintf(btf->name, sizeof(btf->name), "vmlinux"); | |
8580ac94 AS |
5657 | |
5658 | err = btf_parse_hdr(env); | |
5659 | if (err) | |
5660 | goto errout; | |
5661 | ||
5662 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
5663 | ||
5664 | err = btf_parse_str_sec(env); | |
5665 | if (err) | |
5666 | goto errout; | |
5667 | ||
5668 | err = btf_check_all_metas(env); | |
5669 | if (err) | |
5670 | goto errout; | |
5671 | ||
eb596b09 KKD |
5672 | err = btf_check_type_tags(env, btf, 1); |
5673 | if (err) | |
5674 | goto errout; | |
5675 | ||
a2d0d62f | 5676 | /* btf_parse_vmlinux() runs under bpf_verifier_lock */ |
49f4e672 | 5677 | bpf_ctx_convert.t = btf_type_by_id(btf, bpf_ctx_convert_btf_id[0]); |
91cc1a99 | 5678 | |
d3e42bb0 | 5679 | bpf_struct_ops_init(btf, log); |
27ae7997 | 5680 | |
8580ac94 | 5681 | refcount_set(&btf->refcnt, 1); |
53297220 AN |
5682 | |
5683 | err = btf_alloc_id(btf); | |
5684 | if (err) | |
5685 | goto errout; | |
5686 | ||
5687 | btf_verifier_env_free(env); | |
8580ac94 AS |
5688 | return btf; |
5689 | ||
5690 | errout: | |
5691 | btf_verifier_env_free(env); | |
5692 | if (btf) { | |
5693 | kvfree(btf->types); | |
5694 | kfree(btf); | |
5695 | } | |
5696 | return ERR_PTR(err); | |
5697 | } | |
5698 | ||
7112d127 AN |
5699 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
5700 | ||
36e68442 AN |
5701 | static struct btf *btf_parse_module(const char *module_name, const void *data, unsigned int data_size) |
5702 | { | |
5703 | struct btf_verifier_env *env = NULL; | |
5704 | struct bpf_verifier_log *log; | |
5705 | struct btf *btf = NULL, *base_btf; | |
5706 | int err; | |
5707 | ||
5708 | base_btf = bpf_get_btf_vmlinux(); | |
5709 | if (IS_ERR(base_btf)) | |
5710 | return base_btf; | |
5711 | if (!base_btf) | |
5712 | return ERR_PTR(-EINVAL); | |
5713 | ||
5714 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
5715 | if (!env) | |
5716 | return ERR_PTR(-ENOMEM); | |
5717 | ||
5718 | log = &env->log; | |
5719 | log->level = BPF_LOG_KERNEL; | |
5720 | ||
5721 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
5722 | if (!btf) { | |
5723 | err = -ENOMEM; | |
5724 | goto errout; | |
5725 | } | |
5726 | env->btf = btf; | |
5727 | ||
5728 | btf->base_btf = base_btf; | |
5729 | btf->start_id = base_btf->nr_types; | |
5730 | btf->start_str_off = base_btf->hdr.str_len; | |
5731 | btf->kernel_btf = true; | |
5732 | snprintf(btf->name, sizeof(btf->name), "%s", module_name); | |
5733 | ||
5734 | btf->data = kvmalloc(data_size, GFP_KERNEL | __GFP_NOWARN); | |
5735 | if (!btf->data) { | |
5736 | err = -ENOMEM; | |
5737 | goto errout; | |
5738 | } | |
5739 | memcpy(btf->data, data, data_size); | |
5740 | btf->data_size = data_size; | |
5741 | ||
5742 | err = btf_parse_hdr(env); | |
5743 | if (err) | |
5744 | goto errout; | |
5745 | ||
5746 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
5747 | ||
5748 | err = btf_parse_str_sec(env); | |
5749 | if (err) | |
5750 | goto errout; | |
5751 | ||
5752 | err = btf_check_all_metas(env); | |
5753 | if (err) | |
5754 | goto errout; | |
5755 | ||
eb596b09 KKD |
5756 | err = btf_check_type_tags(env, btf, btf_nr_types(base_btf)); |
5757 | if (err) | |
5758 | goto errout; | |
5759 | ||
36e68442 AN |
5760 | btf_verifier_env_free(env); |
5761 | refcount_set(&btf->refcnt, 1); | |
5762 | return btf; | |
5763 | ||
5764 | errout: | |
5765 | btf_verifier_env_free(env); | |
5766 | if (btf) { | |
5767 | kvfree(btf->data); | |
5768 | kvfree(btf->types); | |
5769 | kfree(btf); | |
5770 | } | |
5771 | return ERR_PTR(err); | |
5772 | } | |
5773 | ||
7112d127 AN |
5774 | #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */ |
5775 | ||
5b92a28a AS |
5776 | struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog) |
5777 | { | |
3aac1ead | 5778 | struct bpf_prog *tgt_prog = prog->aux->dst_prog; |
5b92a28a | 5779 | |
22dc4a0f | 5780 | if (tgt_prog) |
5b92a28a | 5781 | return tgt_prog->aux->btf; |
22dc4a0f AN |
5782 | else |
5783 | return prog->aux->attach_btf; | |
5b92a28a AS |
5784 | } |
5785 | ||
bb6728d7 | 5786 | static bool is_int_ptr(struct btf *btf, const struct btf_type *t) |
84ad7a7a JO |
5787 | { |
5788 | /* t comes in already as a pointer */ | |
5789 | t = btf_type_by_id(btf, t->type); | |
5790 | ||
5791 | /* allow const */ | |
5792 | if (BTF_INFO_KIND(t->info) == BTF_KIND_CONST) | |
5793 | t = btf_type_by_id(btf, t->type); | |
5794 | ||
bb6728d7 | 5795 | return btf_type_is_int(t); |
84ad7a7a JO |
5796 | } |
5797 | ||
720e6a43 YS |
5798 | static u32 get_ctx_arg_idx(struct btf *btf, const struct btf_type *func_proto, |
5799 | int off) | |
5800 | { | |
5801 | const struct btf_param *args; | |
5802 | const struct btf_type *t; | |
5803 | u32 offset = 0, nr_args; | |
5804 | int i; | |
5805 | ||
5806 | if (!func_proto) | |
5807 | return off / 8; | |
5808 | ||
5809 | nr_args = btf_type_vlen(func_proto); | |
5810 | args = (const struct btf_param *)(func_proto + 1); | |
5811 | for (i = 0; i < nr_args; i++) { | |
5812 | t = btf_type_skip_modifiers(btf, args[i].type, NULL); | |
5813 | offset += btf_type_is_ptr(t) ? 8 : roundup(t->size, 8); | |
5814 | if (off < offset) | |
5815 | return i; | |
5816 | } | |
5817 | ||
5818 | t = btf_type_skip_modifiers(btf, func_proto->type, NULL); | |
5819 | offset += btf_type_is_ptr(t) ? 8 : roundup(t->size, 8); | |
5820 | if (off < offset) | |
5821 | return nr_args; | |
5822 | ||
5823 | return nr_args + 1; | |
5824 | } | |
5825 | ||
c6b0337f | 5826 | static bool prog_args_trusted(const struct bpf_prog *prog) |
3f00c523 | 5827 | { |
c6b0337f AS |
5828 | enum bpf_attach_type atype = prog->expected_attach_type; |
5829 | ||
5830 | switch (prog->type) { | |
5831 | case BPF_PROG_TYPE_TRACING: | |
5832 | return atype == BPF_TRACE_RAW_TP || atype == BPF_TRACE_ITER; | |
5833 | case BPF_PROG_TYPE_LSM: | |
c0c852dd | 5834 | return bpf_lsm_is_trusted(prog); |
c6b0337f AS |
5835 | case BPF_PROG_TYPE_STRUCT_OPS: |
5836 | return true; | |
5837 | default: | |
5838 | return false; | |
5839 | } | |
3f00c523 DV |
5840 | } |
5841 | ||
9e15db66 AS |
5842 | bool btf_ctx_access(int off, int size, enum bpf_access_type type, |
5843 | const struct bpf_prog *prog, | |
5844 | struct bpf_insn_access_aux *info) | |
5845 | { | |
38207291 | 5846 | const struct btf_type *t = prog->aux->attach_func_proto; |
3aac1ead | 5847 | struct bpf_prog *tgt_prog = prog->aux->dst_prog; |
5b92a28a | 5848 | struct btf *btf = bpf_prog_get_target_btf(prog); |
38207291 | 5849 | const char *tname = prog->aux->attach_func_name; |
9e15db66 | 5850 | struct bpf_verifier_log *log = info->log; |
9e15db66 | 5851 | const struct btf_param *args; |
c6f1bfe8 | 5852 | const char *tag_value; |
9e15db66 | 5853 | u32 nr_args, arg; |
3c32cc1b | 5854 | int i, ret; |
9e15db66 | 5855 | |
9e15db66 | 5856 | if (off % 8) { |
38207291 | 5857 | bpf_log(log, "func '%s' offset %d is not multiple of 8\n", |
9e15db66 AS |
5858 | tname, off); |
5859 | return false; | |
5860 | } | |
720e6a43 | 5861 | arg = get_ctx_arg_idx(btf, t, off); |
9e15db66 | 5862 | args = (const struct btf_param *)(t + 1); |
523a4cf4 DB |
5863 | /* if (t == NULL) Fall back to default BPF prog with |
5864 | * MAX_BPF_FUNC_REG_ARGS u64 arguments. | |
5865 | */ | |
5866 | nr_args = t ? btf_type_vlen(t) : MAX_BPF_FUNC_REG_ARGS; | |
38207291 MKL |
5867 | if (prog->aux->attach_btf_trace) { |
5868 | /* skip first 'void *__data' argument in btf_trace_##name typedef */ | |
5869 | args++; | |
5870 | nr_args--; | |
5871 | } | |
fec56f58 | 5872 | |
f50b49a0 KS |
5873 | if (arg > nr_args) { |
5874 | bpf_log(log, "func '%s' doesn't have %d-th argument\n", | |
5875 | tname, arg + 1); | |
5876 | return false; | |
5877 | } | |
5878 | ||
6ba43b76 | 5879 | if (arg == nr_args) { |
f50b49a0 | 5880 | switch (prog->expected_attach_type) { |
69fd337a | 5881 | case BPF_LSM_CGROUP: |
f50b49a0 KS |
5882 | case BPF_LSM_MAC: |
5883 | case BPF_TRACE_FEXIT: | |
9e4e01df KS |
5884 | /* When LSM programs are attached to void LSM hooks |
5885 | * they use FEXIT trampolines and when attached to | |
5886 | * int LSM hooks, they use MODIFY_RETURN trampolines. | |
5887 | * | |
5888 | * While the LSM programs are BPF_MODIFY_RETURN-like | |
5889 | * the check: | |
5890 | * | |
5891 | * if (ret_type != 'int') | |
5892 | * return -EINVAL; | |
5893 | * | |
5894 | * is _not_ done here. This is still safe as LSM hooks | |
5895 | * have only void and int return types. | |
5896 | */ | |
6ba43b76 KS |
5897 | if (!t) |
5898 | return true; | |
5899 | t = btf_type_by_id(btf, t->type); | |
f50b49a0 KS |
5900 | break; |
5901 | case BPF_MODIFY_RETURN: | |
6ba43b76 KS |
5902 | /* For now the BPF_MODIFY_RETURN can only be attached to |
5903 | * functions that return an int. | |
5904 | */ | |
5905 | if (!t) | |
5906 | return false; | |
5907 | ||
5908 | t = btf_type_skip_modifiers(btf, t->type, NULL); | |
a9b59159 | 5909 | if (!btf_type_is_small_int(t)) { |
6ba43b76 KS |
5910 | bpf_log(log, |
5911 | "ret type %s not allowed for fmod_ret\n", | |
571f9738 | 5912 | btf_type_str(t)); |
6ba43b76 KS |
5913 | return false; |
5914 | } | |
f50b49a0 KS |
5915 | break; |
5916 | default: | |
5917 | bpf_log(log, "func '%s' doesn't have %d-th argument\n", | |
5918 | tname, arg + 1); | |
5919 | return false; | |
6ba43b76 | 5920 | } |
fec56f58 | 5921 | } else { |
5b92a28a | 5922 | if (!t) |
523a4cf4 | 5923 | /* Default prog with MAX_BPF_FUNC_REG_ARGS args */ |
5b92a28a AS |
5924 | return true; |
5925 | t = btf_type_by_id(btf, args[arg].type); | |
9e15db66 | 5926 | } |
f50b49a0 | 5927 | |
9e15db66 AS |
5928 | /* skip modifiers */ |
5929 | while (btf_type_is_modifier(t)) | |
5b92a28a | 5930 | t = btf_type_by_id(btf, t->type); |
720e6a43 | 5931 | if (btf_type_is_small_int(t) || btf_is_any_enum(t) || __btf_type_is_struct(t)) |
9e15db66 AS |
5932 | /* accessing a scalar */ |
5933 | return true; | |
5934 | if (!btf_type_is_ptr(t)) { | |
5935 | bpf_log(log, | |
38207291 | 5936 | "func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n", |
9e15db66 | 5937 | tname, arg, |
5b92a28a | 5938 | __btf_name_by_offset(btf, t->name_off), |
571f9738 | 5939 | btf_type_str(t)); |
9e15db66 AS |
5940 | return false; |
5941 | } | |
afbf21dc YS |
5942 | |
5943 | /* check for PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL */ | |
5944 | for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { | |
5945 | const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; | |
c25b2ae1 | 5946 | u32 type, flag; |
afbf21dc | 5947 | |
c25b2ae1 HL |
5948 | type = base_type(ctx_arg_info->reg_type); |
5949 | flag = type_flag(ctx_arg_info->reg_type); | |
20b2aff4 | 5950 | if (ctx_arg_info->offset == off && type == PTR_TO_BUF && |
c25b2ae1 | 5951 | (flag & PTR_MAYBE_NULL)) { |
afbf21dc YS |
5952 | info->reg_type = ctx_arg_info->reg_type; |
5953 | return true; | |
5954 | } | |
5955 | } | |
5956 | ||
9e15db66 AS |
5957 | if (t->type == 0) |
5958 | /* This is a pointer to void. | |
5959 | * It is the same as scalar from the verifier safety pov. | |
5960 | * No further pointer walking is allowed. | |
5961 | */ | |
5962 | return true; | |
5963 | ||
bb6728d7 | 5964 | if (is_int_ptr(btf, t)) |
84ad7a7a JO |
5965 | return true; |
5966 | ||
9e15db66 | 5967 | /* this is a pointer to another type */ |
3c32cc1b YS |
5968 | for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { |
5969 | const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; | |
5970 | ||
5971 | if (ctx_arg_info->offset == off) { | |
d3621642 YS |
5972 | if (!ctx_arg_info->btf_id) { |
5973 | bpf_log(log,"invalid btf_id for context argument offset %u\n", off); | |
5974 | return false; | |
5975 | } | |
5976 | ||
3c32cc1b | 5977 | info->reg_type = ctx_arg_info->reg_type; |
22dc4a0f | 5978 | info->btf = btf_vmlinux; |
951cf368 YS |
5979 | info->btf_id = ctx_arg_info->btf_id; |
5980 | return true; | |
3c32cc1b YS |
5981 | } |
5982 | } | |
9e15db66 | 5983 | |
951cf368 | 5984 | info->reg_type = PTR_TO_BTF_ID; |
c6b0337f | 5985 | if (prog_args_trusted(prog)) |
3f00c523 DV |
5986 | info->reg_type |= PTR_TRUSTED; |
5987 | ||
5b92a28a | 5988 | if (tgt_prog) { |
43bc2874 THJ |
5989 | enum bpf_prog_type tgt_type; |
5990 | ||
5991 | if (tgt_prog->type == BPF_PROG_TYPE_EXT) | |
5992 | tgt_type = tgt_prog->aux->saved_dst_prog_type; | |
5993 | else | |
5994 | tgt_type = tgt_prog->type; | |
5995 | ||
5996 | ret = btf_translate_to_vmlinux(log, btf, t, tgt_type, arg); | |
5b92a28a | 5997 | if (ret > 0) { |
22dc4a0f | 5998 | info->btf = btf_vmlinux; |
5b92a28a AS |
5999 | info->btf_id = ret; |
6000 | return true; | |
6001 | } else { | |
6002 | return false; | |
6003 | } | |
6004 | } | |
275517ff | 6005 | |
22dc4a0f | 6006 | info->btf = btf; |
275517ff | 6007 | info->btf_id = t->type; |
5b92a28a | 6008 | t = btf_type_by_id(btf, t->type); |
c6f1bfe8 YS |
6009 | |
6010 | if (btf_type_is_type_tag(t)) { | |
6011 | tag_value = __btf_name_by_offset(btf, t->name_off); | |
6012 | if (strcmp(tag_value, "user") == 0) | |
6013 | info->reg_type |= MEM_USER; | |
5844101a HL |
6014 | if (strcmp(tag_value, "percpu") == 0) |
6015 | info->reg_type |= MEM_PERCPU; | |
c6f1bfe8 YS |
6016 | } |
6017 | ||
9e15db66 | 6018 | /* skip modifiers */ |
275517ff MKL |
6019 | while (btf_type_is_modifier(t)) { |
6020 | info->btf_id = t->type; | |
5b92a28a | 6021 | t = btf_type_by_id(btf, t->type); |
275517ff | 6022 | } |
9e15db66 AS |
6023 | if (!btf_type_is_struct(t)) { |
6024 | bpf_log(log, | |
38207291 | 6025 | "func '%s' arg%d type %s is not a struct\n", |
571f9738 | 6026 | tname, arg, btf_type_str(t)); |
9e15db66 AS |
6027 | return false; |
6028 | } | |
38207291 | 6029 | bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n", |
571f9738 | 6030 | tname, arg, info->btf_id, btf_type_str(t), |
5b92a28a | 6031 | __btf_name_by_offset(btf, t->name_off)); |
9e15db66 AS |
6032 | return true; |
6033 | } | |
6034 | ||
1c6d28a6 JO |
6035 | enum bpf_struct_walk_result { |
6036 | /* < 0 error */ | |
6037 | WALK_SCALAR = 0, | |
6038 | WALK_PTR, | |
6039 | WALK_STRUCT, | |
6040 | }; | |
6041 | ||
22dc4a0f | 6042 | static int btf_struct_walk(struct bpf_verifier_log *log, const struct btf *btf, |
1c6d28a6 | 6043 | const struct btf_type *t, int off, int size, |
c6f1bfe8 | 6044 | u32 *next_btf_id, enum bpf_type_flag *flag) |
9e15db66 | 6045 | { |
7e3617a7 MKL |
6046 | u32 i, moff, mtrue_end, msize = 0, total_nelems = 0; |
6047 | const struct btf_type *mtype, *elem_type = NULL; | |
9e15db66 | 6048 | const struct btf_member *member; |
c6f1bfe8 | 6049 | const char *tname, *mname, *tag_value; |
1c6d28a6 | 6050 | u32 vlen, elem_id, mid; |
9e15db66 AS |
6051 | |
6052 | again: | |
22dc4a0f | 6053 | tname = __btf_name_by_offset(btf, t->name_off); |
9e15db66 | 6054 | if (!btf_type_is_struct(t)) { |
275517ff | 6055 | bpf_log(log, "Type '%s' is not a struct\n", tname); |
9e15db66 AS |
6056 | return -EINVAL; |
6057 | } | |
6058 | ||
9c5f8a10 | 6059 | vlen = btf_type_vlen(t); |
976aba00 | 6060 | if (off + size > t->size) { |
9c5f8a10 YS |
6061 | /* If the last element is a variable size array, we may |
6062 | * need to relax the rule. | |
6063 | */ | |
6064 | struct btf_array *array_elem; | |
6065 | ||
6066 | if (vlen == 0) | |
6067 | goto error; | |
6068 | ||
6069 | member = btf_type_member(t) + vlen - 1; | |
22dc4a0f | 6070 | mtype = btf_type_skip_modifiers(btf, member->type, |
9c5f8a10 YS |
6071 | NULL); |
6072 | if (!btf_type_is_array(mtype)) | |
6073 | goto error; | |
6074 | ||
6075 | array_elem = (struct btf_array *)(mtype + 1); | |
6076 | if (array_elem->nelems != 0) | |
6077 | goto error; | |
6078 | ||
8293eb99 | 6079 | moff = __btf_member_bit_offset(t, member) / 8; |
9c5f8a10 YS |
6080 | if (off < moff) |
6081 | goto error; | |
6082 | ||
6083 | /* Only allow structure for now, can be relaxed for | |
6084 | * other types later. | |
6085 | */ | |
22dc4a0f | 6086 | t = btf_type_skip_modifiers(btf, array_elem->type, |
dafe58fc JO |
6087 | NULL); |
6088 | if (!btf_type_is_struct(t)) | |
9c5f8a10 YS |
6089 | goto error; |
6090 | ||
dafe58fc JO |
6091 | off = (off - moff) % t->size; |
6092 | goto again; | |
9c5f8a10 YS |
6093 | |
6094 | error: | |
976aba00 MKL |
6095 | bpf_log(log, "access beyond struct %s at off %u size %u\n", |
6096 | tname, off, size); | |
6097 | return -EACCES; | |
6098 | } | |
9e15db66 | 6099 | |
976aba00 | 6100 | for_each_member(i, t, member) { |
7e3617a7 | 6101 | /* offset of the field in bytes */ |
8293eb99 | 6102 | moff = __btf_member_bit_offset(t, member) / 8; |
7e3617a7 | 6103 | if (off + size <= moff) |
9e15db66 AS |
6104 | /* won't find anything, field is already too far */ |
6105 | break; | |
976aba00 | 6106 | |
8293eb99 AS |
6107 | if (__btf_member_bitfield_size(t, member)) { |
6108 | u32 end_bit = __btf_member_bit_offset(t, member) + | |
6109 | __btf_member_bitfield_size(t, member); | |
976aba00 MKL |
6110 | |
6111 | /* off <= moff instead of off == moff because clang | |
6112 | * does not generate a BTF member for anonymous | |
6113 | * bitfield like the ":16" here: | |
6114 | * struct { | |
6115 | * int :16; | |
6116 | * int x:8; | |
6117 | * }; | |
6118 | */ | |
6119 | if (off <= moff && | |
6120 | BITS_ROUNDUP_BYTES(end_bit) <= off + size) | |
1c6d28a6 | 6121 | return WALK_SCALAR; |
976aba00 MKL |
6122 | |
6123 | /* off may be accessing a following member | |
6124 | * | |
6125 | * or | |
6126 | * | |
6127 | * Doing partial access at either end of this | |
6128 | * bitfield. Continue on this case also to | |
6129 | * treat it as not accessing this bitfield | |
6130 | * and eventually error out as field not | |
6131 | * found to keep it simple. | |
6132 | * It could be relaxed if there was a legit | |
6133 | * partial access case later. | |
6134 | */ | |
6135 | continue; | |
6136 | } | |
6137 | ||
7e3617a7 MKL |
6138 | /* In case of "off" is pointing to holes of a struct */ |
6139 | if (off < moff) | |
976aba00 | 6140 | break; |
9e15db66 AS |
6141 | |
6142 | /* type of the field */ | |
1c6d28a6 | 6143 | mid = member->type; |
22dc4a0f AN |
6144 | mtype = btf_type_by_id(btf, member->type); |
6145 | mname = __btf_name_by_offset(btf, member->name_off); | |
9e15db66 | 6146 | |
22dc4a0f | 6147 | mtype = __btf_resolve_size(btf, mtype, &msize, |
1c6d28a6 JO |
6148 | &elem_type, &elem_id, &total_nelems, |
6149 | &mid); | |
7e3617a7 | 6150 | if (IS_ERR(mtype)) { |
9e15db66 AS |
6151 | bpf_log(log, "field %s doesn't have size\n", mname); |
6152 | return -EFAULT; | |
6153 | } | |
7e3617a7 MKL |
6154 | |
6155 | mtrue_end = moff + msize; | |
6156 | if (off >= mtrue_end) | |
9e15db66 AS |
6157 | /* no overlap with member, keep iterating */ |
6158 | continue; | |
7e3617a7 MKL |
6159 | |
6160 | if (btf_type_is_array(mtype)) { | |
6161 | u32 elem_idx; | |
6162 | ||
6298399b | 6163 | /* __btf_resolve_size() above helps to |
7e3617a7 MKL |
6164 | * linearize a multi-dimensional array. |
6165 | * | |
6166 | * The logic here is treating an array | |
6167 | * in a struct as the following way: | |
6168 | * | |
6169 | * struct outer { | |
6170 | * struct inner array[2][2]; | |
6171 | * }; | |
6172 | * | |
6173 | * looks like: | |
6174 | * | |
6175 | * struct outer { | |
6176 | * struct inner array_elem0; | |
6177 | * struct inner array_elem1; | |
6178 | * struct inner array_elem2; | |
6179 | * struct inner array_elem3; | |
6180 | * }; | |
6181 | * | |
6182 | * When accessing outer->array[1][0], it moves | |
6183 | * moff to "array_elem2", set mtype to | |
6184 | * "struct inner", and msize also becomes | |
6185 | * sizeof(struct inner). Then most of the | |
6186 | * remaining logic will fall through without | |
6187 | * caring the current member is an array or | |
6188 | * not. | |
6189 | * | |
6190 | * Unlike mtype/msize/moff, mtrue_end does not | |
6191 | * change. The naming difference ("_true") tells | |
6192 | * that it is not always corresponding to | |
6193 | * the current mtype/msize/moff. | |
6194 | * It is the true end of the current | |
6195 | * member (i.e. array in this case). That | |
6196 | * will allow an int array to be accessed like | |
6197 | * a scratch space, | |
6198 | * i.e. allow access beyond the size of | |
6199 | * the array's element as long as it is | |
6200 | * within the mtrue_end boundary. | |
6201 | */ | |
6202 | ||
6203 | /* skip empty array */ | |
6204 | if (moff == mtrue_end) | |
6205 | continue; | |
6206 | ||
6207 | msize /= total_nelems; | |
6208 | elem_idx = (off - moff) / msize; | |
6209 | moff += elem_idx * msize; | |
6210 | mtype = elem_type; | |
1c6d28a6 | 6211 | mid = elem_id; |
7e3617a7 MKL |
6212 | } |
6213 | ||
9e15db66 AS |
6214 | /* the 'off' we're looking for is either equal to start |
6215 | * of this field or inside of this struct | |
6216 | */ | |
6217 | if (btf_type_is_struct(mtype)) { | |
6218 | /* our field must be inside that union or struct */ | |
6219 | t = mtype; | |
6220 | ||
1c6d28a6 JO |
6221 | /* return if the offset matches the member offset */ |
6222 | if (off == moff) { | |
6223 | *next_btf_id = mid; | |
6224 | return WALK_STRUCT; | |
6225 | } | |
6226 | ||
9e15db66 | 6227 | /* adjust offset we're looking for */ |
7e3617a7 | 6228 | off -= moff; |
9e15db66 AS |
6229 | goto again; |
6230 | } | |
9e15db66 AS |
6231 | |
6232 | if (btf_type_is_ptr(mtype)) { | |
c6f1bfe8 YS |
6233 | const struct btf_type *stype, *t; |
6234 | enum bpf_type_flag tmp_flag = 0; | |
257af63d | 6235 | u32 id; |
9e15db66 | 6236 | |
7e3617a7 MKL |
6237 | if (msize != size || off != moff) { |
6238 | bpf_log(log, | |
6239 | "cannot access ptr member %s with moff %u in struct %s with off %u size %u\n", | |
6240 | mname, moff, tname, off, size); | |
6241 | return -EACCES; | |
6242 | } | |
c6f1bfe8 | 6243 | |
5844101a | 6244 | /* check type tag */ |
c6f1bfe8 YS |
6245 | t = btf_type_by_id(btf, mtype->type); |
6246 | if (btf_type_is_type_tag(t)) { | |
6247 | tag_value = __btf_name_by_offset(btf, t->name_off); | |
5844101a | 6248 | /* check __user tag */ |
c6f1bfe8 YS |
6249 | if (strcmp(tag_value, "user") == 0) |
6250 | tmp_flag = MEM_USER; | |
5844101a HL |
6251 | /* check __percpu tag */ |
6252 | if (strcmp(tag_value, "percpu") == 0) | |
6253 | tmp_flag = MEM_PERCPU; | |
9bb00b28 YS |
6254 | /* check __rcu tag */ |
6255 | if (strcmp(tag_value, "rcu") == 0) | |
6256 | tmp_flag = MEM_RCU; | |
c6f1bfe8 YS |
6257 | } |
6258 | ||
22dc4a0f | 6259 | stype = btf_type_skip_modifiers(btf, mtype->type, &id); |
9e15db66 | 6260 | if (btf_type_is_struct(stype)) { |
257af63d | 6261 | *next_btf_id = id; |
c6f1bfe8 | 6262 | *flag = tmp_flag; |
1c6d28a6 | 6263 | return WALK_PTR; |
9e15db66 AS |
6264 | } |
6265 | } | |
7e3617a7 MKL |
6266 | |
6267 | /* Allow more flexible access within an int as long as | |
6268 | * it is within mtrue_end. | |
6269 | * Since mtrue_end could be the end of an array, | |
6270 | * that also allows using an array of int as a scratch | |
6271 | * space. e.g. skb->cb[]. | |
6272 | */ | |
6273 | if (off + size > mtrue_end) { | |
6274 | bpf_log(log, | |
6275 | "access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n", | |
6276 | mname, mtrue_end, tname, off, size); | |
6277 | return -EACCES; | |
6278 | } | |
6279 | ||
1c6d28a6 | 6280 | return WALK_SCALAR; |
9e15db66 AS |
6281 | } |
6282 | bpf_log(log, "struct %s doesn't have field at offset %d\n", tname, off); | |
6283 | return -EINVAL; | |
6284 | } | |
6285 | ||
6728aea7 KKD |
6286 | int btf_struct_access(struct bpf_verifier_log *log, |
6287 | const struct bpf_reg_state *reg, | |
6288 | int off, int size, enum bpf_access_type atype __maybe_unused, | |
c6f1bfe8 | 6289 | u32 *next_btf_id, enum bpf_type_flag *flag) |
1c6d28a6 | 6290 | { |
6728aea7 | 6291 | const struct btf *btf = reg->btf; |
c6f1bfe8 | 6292 | enum bpf_type_flag tmp_flag = 0; |
6728aea7 KKD |
6293 | const struct btf_type *t; |
6294 | u32 id = reg->btf_id; | |
1c6d28a6 | 6295 | int err; |
1c6d28a6 | 6296 | |
8ffa5cc1 KKD |
6297 | while (type_is_alloc(reg->type)) { |
6298 | struct btf_struct_meta *meta; | |
6299 | struct btf_record *rec; | |
6300 | int i; | |
6301 | ||
6302 | meta = btf_find_struct_meta(btf, id); | |
6303 | if (!meta) | |
6304 | break; | |
6305 | rec = meta->record; | |
6306 | for (i = 0; i < rec->cnt; i++) { | |
6307 | struct btf_field *field = &rec->fields[i]; | |
6308 | u32 offset = field->offset; | |
6309 | if (off < offset + btf_field_type_size(field->type) && offset < off + size) { | |
6310 | bpf_log(log, | |
6311 | "direct access to %s is disallowed\n", | |
6312 | btf_field_type_name(field->type)); | |
6313 | return -EACCES; | |
6314 | } | |
6315 | } | |
6316 | break; | |
6317 | } | |
6318 | ||
6728aea7 | 6319 | t = btf_type_by_id(btf, id); |
1c6d28a6 | 6320 | do { |
c6f1bfe8 | 6321 | err = btf_struct_walk(log, btf, t, off, size, &id, &tmp_flag); |
1c6d28a6 JO |
6322 | |
6323 | switch (err) { | |
6324 | case WALK_PTR: | |
282de143 KKD |
6325 | /* For local types, the destination register cannot |
6326 | * become a pointer again. | |
6327 | */ | |
6328 | if (type_is_alloc(reg->type)) | |
6329 | return SCALAR_VALUE; | |
1c6d28a6 JO |
6330 | /* If we found the pointer or scalar on t+off, |
6331 | * we're done. | |
6332 | */ | |
6333 | *next_btf_id = id; | |
c6f1bfe8 | 6334 | *flag = tmp_flag; |
1c6d28a6 JO |
6335 | return PTR_TO_BTF_ID; |
6336 | case WALK_SCALAR: | |
6337 | return SCALAR_VALUE; | |
6338 | case WALK_STRUCT: | |
6339 | /* We found nested struct, so continue the search | |
6340 | * by diving in it. At this point the offset is | |
6341 | * aligned with the new type, so set it to 0. | |
6342 | */ | |
22dc4a0f | 6343 | t = btf_type_by_id(btf, id); |
1c6d28a6 JO |
6344 | off = 0; |
6345 | break; | |
6346 | default: | |
6347 | /* It's either error or unknown return value.. | |
6348 | * scream and leave. | |
6349 | */ | |
6350 | if (WARN_ONCE(err > 0, "unknown btf_struct_walk return value")) | |
6351 | return -EINVAL; | |
6352 | return err; | |
6353 | } | |
6354 | } while (t); | |
6355 | ||
6356 | return -EINVAL; | |
6357 | } | |
6358 | ||
22dc4a0f AN |
6359 | /* Check that two BTF types, each specified as an BTF object + id, are exactly |
6360 | * the same. Trivial ID check is not enough due to module BTFs, because we can | |
6361 | * end up with two different module BTFs, but IDs point to the common type in | |
6362 | * vmlinux BTF. | |
6363 | */ | |
00b85860 KKD |
6364 | bool btf_types_are_same(const struct btf *btf1, u32 id1, |
6365 | const struct btf *btf2, u32 id2) | |
22dc4a0f AN |
6366 | { |
6367 | if (id1 != id2) | |
6368 | return false; | |
6369 | if (btf1 == btf2) | |
6370 | return true; | |
6371 | return btf_type_by_id(btf1, id1) == btf_type_by_id(btf2, id2); | |
6372 | } | |
6373 | ||
faaf4a79 | 6374 | bool btf_struct_ids_match(struct bpf_verifier_log *log, |
22dc4a0f | 6375 | const struct btf *btf, u32 id, int off, |
2ab3b380 KKD |
6376 | const struct btf *need_btf, u32 need_type_id, |
6377 | bool strict) | |
faaf4a79 JO |
6378 | { |
6379 | const struct btf_type *type; | |
c6f1bfe8 | 6380 | enum bpf_type_flag flag; |
faaf4a79 JO |
6381 | int err; |
6382 | ||
6383 | /* Are we already done? */ | |
22dc4a0f | 6384 | if (off == 0 && btf_types_are_same(btf, id, need_btf, need_type_id)) |
faaf4a79 | 6385 | return true; |
2ab3b380 KKD |
6386 | /* In case of strict type match, we do not walk struct, the top level |
6387 | * type match must succeed. When strict is true, off should have already | |
6388 | * been 0. | |
6389 | */ | |
6390 | if (strict) | |
6391 | return false; | |
faaf4a79 | 6392 | again: |
22dc4a0f | 6393 | type = btf_type_by_id(btf, id); |
faaf4a79 JO |
6394 | if (!type) |
6395 | return false; | |
c6f1bfe8 | 6396 | err = btf_struct_walk(log, btf, type, off, 1, &id, &flag); |
faaf4a79 JO |
6397 | if (err != WALK_STRUCT) |
6398 | return false; | |
6399 | ||
6400 | /* We found nested struct object. If it matches | |
6401 | * the requested ID, we're done. Otherwise let's | |
6402 | * continue the search with offset 0 in the new | |
6403 | * type. | |
6404 | */ | |
22dc4a0f | 6405 | if (!btf_types_are_same(btf, id, need_btf, need_type_id)) { |
faaf4a79 JO |
6406 | off = 0; |
6407 | goto again; | |
6408 | } | |
6409 | ||
6410 | return true; | |
6411 | } | |
6412 | ||
fec56f58 | 6413 | static int __get_type_size(struct btf *btf, u32 btf_id, |
a00ed843 | 6414 | const struct btf_type **ret_type) |
fec56f58 AS |
6415 | { |
6416 | const struct btf_type *t; | |
6417 | ||
a00ed843 | 6418 | *ret_type = btf_type_by_id(btf, 0); |
fec56f58 AS |
6419 | if (!btf_id) |
6420 | /* void */ | |
6421 | return 0; | |
6422 | t = btf_type_by_id(btf, btf_id); | |
6423 | while (t && btf_type_is_modifier(t)) | |
6424 | t = btf_type_by_id(btf, t->type); | |
a00ed843 | 6425 | if (!t) |
fec56f58 | 6426 | return -EINVAL; |
a00ed843 | 6427 | *ret_type = t; |
fec56f58 AS |
6428 | if (btf_type_is_ptr(t)) |
6429 | /* kernel size of pointer. Not BPF's size of pointer*/ | |
6430 | return sizeof(void *); | |
720e6a43 | 6431 | if (btf_type_is_int(t) || btf_is_any_enum(t) || __btf_type_is_struct(t)) |
fec56f58 | 6432 | return t->size; |
fec56f58 AS |
6433 | return -EINVAL; |
6434 | } | |
6435 | ||
6436 | int btf_distill_func_proto(struct bpf_verifier_log *log, | |
6437 | struct btf *btf, | |
6438 | const struct btf_type *func, | |
6439 | const char *tname, | |
6440 | struct btf_func_model *m) | |
6441 | { | |
6442 | const struct btf_param *args; | |
6443 | const struct btf_type *t; | |
6444 | u32 i, nargs; | |
6445 | int ret; | |
6446 | ||
5b92a28a AS |
6447 | if (!func) { |
6448 | /* BTF function prototype doesn't match the verifier types. | |
523a4cf4 | 6449 | * Fall back to MAX_BPF_FUNC_REG_ARGS u64 args. |
5b92a28a | 6450 | */ |
720e6a43 | 6451 | for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++) { |
5b92a28a | 6452 | m->arg_size[i] = 8; |
720e6a43 YS |
6453 | m->arg_flags[i] = 0; |
6454 | } | |
5b92a28a | 6455 | m->ret_size = 8; |
523a4cf4 | 6456 | m->nr_args = MAX_BPF_FUNC_REG_ARGS; |
5b92a28a AS |
6457 | return 0; |
6458 | } | |
fec56f58 AS |
6459 | args = (const struct btf_param *)(func + 1); |
6460 | nargs = btf_type_vlen(func); | |
c29a4920 | 6461 | if (nargs > MAX_BPF_FUNC_ARGS) { |
fec56f58 AS |
6462 | bpf_log(log, |
6463 | "The function %s has %d arguments. Too many.\n", | |
6464 | tname, nargs); | |
6465 | return -EINVAL; | |
6466 | } | |
6467 | ret = __get_type_size(btf, func->type, &t); | |
720e6a43 | 6468 | if (ret < 0 || __btf_type_is_struct(t)) { |
fec56f58 AS |
6469 | bpf_log(log, |
6470 | "The function %s return type %s is unsupported.\n", | |
571f9738 | 6471 | tname, btf_type_str(t)); |
fec56f58 AS |
6472 | return -EINVAL; |
6473 | } | |
6474 | m->ret_size = ret; | |
6475 | ||
6476 | for (i = 0; i < nargs; i++) { | |
31379397 JO |
6477 | if (i == nargs - 1 && args[i].type == 0) { |
6478 | bpf_log(log, | |
6479 | "The function %s with variable args is unsupported.\n", | |
6480 | tname); | |
6481 | return -EINVAL; | |
6482 | } | |
fec56f58 | 6483 | ret = __get_type_size(btf, args[i].type, &t); |
720e6a43 YS |
6484 | |
6485 | /* No support of struct argument size greater than 16 bytes */ | |
6486 | if (ret < 0 || ret > 16) { | |
fec56f58 AS |
6487 | bpf_log(log, |
6488 | "The function %s arg%d type %s is unsupported.\n", | |
571f9738 | 6489 | tname, i, btf_type_str(t)); |
fec56f58 AS |
6490 | return -EINVAL; |
6491 | } | |
31379397 JO |
6492 | if (ret == 0) { |
6493 | bpf_log(log, | |
6494 | "The function %s has malformed void argument.\n", | |
6495 | tname); | |
6496 | return -EINVAL; | |
6497 | } | |
fec56f58 | 6498 | m->arg_size[i] = ret; |
720e6a43 | 6499 | m->arg_flags[i] = __btf_type_is_struct(t) ? BTF_FMODEL_STRUCT_ARG : 0; |
fec56f58 AS |
6500 | } |
6501 | m->nr_args = nargs; | |
6502 | return 0; | |
6503 | } | |
6504 | ||
be8704ff AS |
6505 | /* Compare BTFs of two functions assuming only scalars and pointers to context. |
6506 | * t1 points to BTF_KIND_FUNC in btf1 | |
6507 | * t2 points to BTF_KIND_FUNC in btf2 | |
6508 | * Returns: | |
6509 | * EINVAL - function prototype mismatch | |
6510 | * EFAULT - verifier bug | |
6511 | * 0 - 99% match. The last 1% is validated by the verifier. | |
6512 | */ | |
2bf0eb9b HY |
6513 | static int btf_check_func_type_match(struct bpf_verifier_log *log, |
6514 | struct btf *btf1, const struct btf_type *t1, | |
6515 | struct btf *btf2, const struct btf_type *t2) | |
be8704ff AS |
6516 | { |
6517 | const struct btf_param *args1, *args2; | |
6518 | const char *fn1, *fn2, *s1, *s2; | |
6519 | u32 nargs1, nargs2, i; | |
6520 | ||
6521 | fn1 = btf_name_by_offset(btf1, t1->name_off); | |
6522 | fn2 = btf_name_by_offset(btf2, t2->name_off); | |
6523 | ||
6524 | if (btf_func_linkage(t1) != BTF_FUNC_GLOBAL) { | |
6525 | bpf_log(log, "%s() is not a global function\n", fn1); | |
6526 | return -EINVAL; | |
6527 | } | |
6528 | if (btf_func_linkage(t2) != BTF_FUNC_GLOBAL) { | |
6529 | bpf_log(log, "%s() is not a global function\n", fn2); | |
6530 | return -EINVAL; | |
6531 | } | |
6532 | ||
6533 | t1 = btf_type_by_id(btf1, t1->type); | |
6534 | if (!t1 || !btf_type_is_func_proto(t1)) | |
6535 | return -EFAULT; | |
6536 | t2 = btf_type_by_id(btf2, t2->type); | |
6537 | if (!t2 || !btf_type_is_func_proto(t2)) | |
6538 | return -EFAULT; | |
6539 | ||
6540 | args1 = (const struct btf_param *)(t1 + 1); | |
6541 | nargs1 = btf_type_vlen(t1); | |
6542 | args2 = (const struct btf_param *)(t2 + 1); | |
6543 | nargs2 = btf_type_vlen(t2); | |
6544 | ||
6545 | if (nargs1 != nargs2) { | |
6546 | bpf_log(log, "%s() has %d args while %s() has %d args\n", | |
6547 | fn1, nargs1, fn2, nargs2); | |
6548 | return -EINVAL; | |
6549 | } | |
6550 | ||
6551 | t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); | |
6552 | t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); | |
6553 | if (t1->info != t2->info) { | |
6554 | bpf_log(log, | |
6555 | "Return type %s of %s() doesn't match type %s of %s()\n", | |
6556 | btf_type_str(t1), fn1, | |
6557 | btf_type_str(t2), fn2); | |
6558 | return -EINVAL; | |
6559 | } | |
6560 | ||
6561 | for (i = 0; i < nargs1; i++) { | |
6562 | t1 = btf_type_skip_modifiers(btf1, args1[i].type, NULL); | |
6563 | t2 = btf_type_skip_modifiers(btf2, args2[i].type, NULL); | |
6564 | ||
6565 | if (t1->info != t2->info) { | |
6566 | bpf_log(log, "arg%d in %s() is %s while %s() has %s\n", | |
6567 | i, fn1, btf_type_str(t1), | |
6568 | fn2, btf_type_str(t2)); | |
6569 | return -EINVAL; | |
6570 | } | |
6571 | if (btf_type_has_size(t1) && t1->size != t2->size) { | |
6572 | bpf_log(log, | |
6573 | "arg%d in %s() has size %d while %s() has %d\n", | |
6574 | i, fn1, t1->size, | |
6575 | fn2, t2->size); | |
6576 | return -EINVAL; | |
6577 | } | |
6578 | ||
6579 | /* global functions are validated with scalars and pointers | |
6580 | * to context only. And only global functions can be replaced. | |
6581 | * Hence type check only those types. | |
6582 | */ | |
6089fb32 | 6583 | if (btf_type_is_int(t1) || btf_is_any_enum(t1)) |
be8704ff AS |
6584 | continue; |
6585 | if (!btf_type_is_ptr(t1)) { | |
6586 | bpf_log(log, | |
6587 | "arg%d in %s() has unrecognized type\n", | |
6588 | i, fn1); | |
6589 | return -EINVAL; | |
6590 | } | |
6591 | t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); | |
6592 | t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); | |
6593 | if (!btf_type_is_struct(t1)) { | |
6594 | bpf_log(log, | |
6595 | "arg%d in %s() is not a pointer to context\n", | |
6596 | i, fn1); | |
6597 | return -EINVAL; | |
6598 | } | |
6599 | if (!btf_type_is_struct(t2)) { | |
6600 | bpf_log(log, | |
6601 | "arg%d in %s() is not a pointer to context\n", | |
6602 | i, fn2); | |
6603 | return -EINVAL; | |
6604 | } | |
6605 | /* This is an optional check to make program writing easier. | |
6606 | * Compare names of structs and report an error to the user. | |
6607 | * btf_prepare_func_args() already checked that t2 struct | |
6608 | * is a context type. btf_prepare_func_args() will check | |
6609 | * later that t1 struct is a context type as well. | |
6610 | */ | |
6611 | s1 = btf_name_by_offset(btf1, t1->name_off); | |
6612 | s2 = btf_name_by_offset(btf2, t2->name_off); | |
6613 | if (strcmp(s1, s2)) { | |
6614 | bpf_log(log, | |
6615 | "arg%d %s(struct %s *) doesn't match %s(struct %s *)\n", | |
6616 | i, fn1, s1, fn2, s2); | |
6617 | return -EINVAL; | |
6618 | } | |
6619 | } | |
6620 | return 0; | |
6621 | } | |
6622 | ||
6623 | /* Compare BTFs of given program with BTF of target program */ | |
efc68158 | 6624 | int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog, |
be8704ff AS |
6625 | struct btf *btf2, const struct btf_type *t2) |
6626 | { | |
6627 | struct btf *btf1 = prog->aux->btf; | |
6628 | const struct btf_type *t1; | |
6629 | u32 btf_id = 0; | |
6630 | ||
6631 | if (!prog->aux->func_info) { | |
efc68158 | 6632 | bpf_log(log, "Program extension requires BTF\n"); |
be8704ff AS |
6633 | return -EINVAL; |
6634 | } | |
6635 | ||
6636 | btf_id = prog->aux->func_info[0].type_id; | |
6637 | if (!btf_id) | |
6638 | return -EFAULT; | |
6639 | ||
6640 | t1 = btf_type_by_id(btf1, btf_id); | |
6641 | if (!t1 || !btf_type_is_func(t1)) | |
6642 | return -EFAULT; | |
6643 | ||
efc68158 | 6644 | return btf_check_func_type_match(log, btf1, t1, btf2, t2); |
be8704ff AS |
6645 | } |
6646 | ||
34747c41 MKL |
6647 | static int btf_check_func_arg_match(struct bpf_verifier_env *env, |
6648 | const struct btf *btf, u32 func_id, | |
6649 | struct bpf_reg_state *regs, | |
a4703e31 | 6650 | bool ptr_to_mem_ok, |
95f2f26f | 6651 | bool processing_call) |
8c1b6e69 | 6652 | { |
f858c2b2 | 6653 | enum bpf_prog_type prog_type = resolve_prog_type(env->prog); |
8c1b6e69 | 6654 | struct bpf_verifier_log *log = &env->log; |
34747c41 | 6655 | const char *func_name, *ref_tname; |
e5069b9c | 6656 | const struct btf_type *t, *ref_t; |
34747c41 | 6657 | const struct btf_param *args; |
00b85860 KKD |
6658 | u32 i, nargs, ref_id; |
6659 | int ret; | |
8c1b6e69 | 6660 | |
34747c41 | 6661 | t = btf_type_by_id(btf, func_id); |
8c1b6e69 | 6662 | if (!t || !btf_type_is_func(t)) { |
51c39bb1 | 6663 | /* These checks were already done by the verifier while loading |
e6ac2450 | 6664 | * struct bpf_func_info or in add_kfunc_call(). |
51c39bb1 | 6665 | */ |
34747c41 MKL |
6666 | bpf_log(log, "BTF of func_id %u doesn't point to KIND_FUNC\n", |
6667 | func_id); | |
51c39bb1 | 6668 | return -EFAULT; |
8c1b6e69 | 6669 | } |
34747c41 | 6670 | func_name = btf_name_by_offset(btf, t->name_off); |
8c1b6e69 AS |
6671 | |
6672 | t = btf_type_by_id(btf, t->type); | |
6673 | if (!t || !btf_type_is_func_proto(t)) { | |
34747c41 | 6674 | bpf_log(log, "Invalid BTF of func %s\n", func_name); |
51c39bb1 | 6675 | return -EFAULT; |
8c1b6e69 AS |
6676 | } |
6677 | args = (const struct btf_param *)(t + 1); | |
6678 | nargs = btf_type_vlen(t); | |
523a4cf4 | 6679 | if (nargs > MAX_BPF_FUNC_REG_ARGS) { |
34747c41 | 6680 | bpf_log(log, "Function %s has %d > %d args\n", func_name, nargs, |
523a4cf4 | 6681 | MAX_BPF_FUNC_REG_ARGS); |
34747c41 | 6682 | return -EINVAL; |
8c1b6e69 | 6683 | } |
e5069b9c | 6684 | |
8c1b6e69 AS |
6685 | /* check that BTF function arguments match actual types that the |
6686 | * verifier sees. | |
6687 | */ | |
6688 | for (i = 0; i < nargs; i++) { | |
8f14852e | 6689 | enum bpf_arg_type arg_type = ARG_DONTCARE; |
34747c41 MKL |
6690 | u32 regno = i + 1; |
6691 | struct bpf_reg_state *reg = ®s[regno]; | |
feb4adfa | 6692 | |
34747c41 MKL |
6693 | t = btf_type_skip_modifiers(btf, args[i].type, NULL); |
6694 | if (btf_type_is_scalar(t)) { | |
feb4adfa | 6695 | if (reg->type == SCALAR_VALUE) |
8c1b6e69 | 6696 | continue; |
34747c41 MKL |
6697 | bpf_log(log, "R%d is not a scalar\n", regno); |
6698 | return -EINVAL; | |
8c1b6e69 | 6699 | } |
34747c41 MKL |
6700 | |
6701 | if (!btf_type_is_ptr(t)) { | |
6702 | bpf_log(log, "Unrecognized arg#%d type %s\n", | |
6703 | i, btf_type_str(t)); | |
6704 | return -EINVAL; | |
6705 | } | |
6706 | ||
e6ac2450 | 6707 | ref_t = btf_type_skip_modifiers(btf, t->type, &ref_id); |
34747c41 | 6708 | ref_tname = btf_name_by_offset(btf, ref_t->name_off); |
655efe50 | 6709 | |
8f14852e | 6710 | ret = check_func_arg_reg_off(env, reg, regno, arg_type); |
655efe50 KKD |
6711 | if (ret < 0) |
6712 | return ret; | |
6713 | ||
00b85860 | 6714 | if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) { |
3363bd0c KKD |
6715 | /* If function expects ctx type in BTF check that caller |
6716 | * is passing PTR_TO_CTX. | |
6717 | */ | |
6718 | if (reg->type != PTR_TO_CTX) { | |
6719 | bpf_log(log, | |
6720 | "arg#%d expected pointer to ctx, but got %s\n", | |
6721 | i, btf_type_str(t)); | |
6722 | return -EINVAL; | |
6723 | } | |
95f2f26f | 6724 | } else if (ptr_to_mem_ok && processing_call) { |
34747c41 MKL |
6725 | const struct btf_type *resolve_ret; |
6726 | u32 type_size; | |
e5069b9c | 6727 | |
34747c41 MKL |
6728 | resolve_ret = btf_resolve_size(btf, ref_t, &type_size); |
6729 | if (IS_ERR(resolve_ret)) { | |
e5069b9c | 6730 | bpf_log(log, |
34747c41 MKL |
6731 | "arg#%d reference type('%s %s') size cannot be determined: %ld\n", |
6732 | i, btf_type_str(ref_t), ref_tname, | |
6733 | PTR_ERR(resolve_ret)); | |
6734 | return -EINVAL; | |
e5069b9c DB |
6735 | } |
6736 | ||
34747c41 MKL |
6737 | if (check_mem_reg(env, reg, regno, type_size)) |
6738 | return -EINVAL; | |
6739 | } else { | |
00b85860 KKD |
6740 | bpf_log(log, "reg type unsupported for arg#%d function %s#%d\n", i, |
6741 | func_name, func_id); | |
34747c41 | 6742 | return -EINVAL; |
8c1b6e69 | 6743 | } |
8c1b6e69 | 6744 | } |
34747c41 | 6745 | |
00b85860 | 6746 | return 0; |
34747c41 MKL |
6747 | } |
6748 | ||
95f2f26f | 6749 | /* Compare BTF of a function declaration with given bpf_reg_state. |
34747c41 MKL |
6750 | * Returns: |
6751 | * EFAULT - there is a verifier bug. Abort verification. | |
6752 | * EINVAL - there is a type mismatch or BTF is not available. | |
6753 | * 0 - BTF matches with what bpf_reg_state expects. | |
6754 | * Only PTR_TO_CTX and SCALAR_VALUE states are recognized. | |
6755 | */ | |
6756 | int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog, | |
6757 | struct bpf_reg_state *regs) | |
6758 | { | |
6759 | struct bpf_prog *prog = env->prog; | |
6760 | struct btf *btf = prog->aux->btf; | |
6761 | bool is_global; | |
6762 | u32 btf_id; | |
6763 | int err; | |
6764 | ||
6765 | if (!prog->aux->func_info) | |
6766 | return -EINVAL; | |
6767 | ||
6768 | btf_id = prog->aux->func_info[subprog].type_id; | |
6769 | if (!btf_id) | |
6770 | return -EFAULT; | |
6771 | ||
6772 | if (prog->aux->func_info_aux[subprog].unreliable) | |
6773 | return -EINVAL; | |
6774 | ||
6775 | is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL; | |
00b85860 | 6776 | err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, false); |
95f2f26f BT |
6777 | |
6778 | /* Compiler optimizations can remove arguments from static functions | |
6779 | * or mismatched type can be passed into a global function. | |
6780 | * In such cases mark the function as unreliable from BTF point of view. | |
6781 | */ | |
6782 | if (err) | |
6783 | prog->aux->func_info_aux[subprog].unreliable = true; | |
6784 | return err; | |
6785 | } | |
6786 | ||
6787 | /* Compare BTF of a function call with given bpf_reg_state. | |
6788 | * Returns: | |
6789 | * EFAULT - there is a verifier bug. Abort verification. | |
6790 | * EINVAL - there is a type mismatch or BTF is not available. | |
6791 | * 0 - BTF matches with what bpf_reg_state expects. | |
6792 | * Only PTR_TO_CTX and SCALAR_VALUE states are recognized. | |
6793 | * | |
6794 | * NOTE: the code is duplicated from btf_check_subprog_arg_match() | |
6795 | * because btf_check_func_arg_match() is still doing both. Once that | |
6796 | * function is split in 2, we can call from here btf_check_subprog_arg_match() | |
6797 | * first, and then treat the calling part in a new code path. | |
6798 | */ | |
6799 | int btf_check_subprog_call(struct bpf_verifier_env *env, int subprog, | |
6800 | struct bpf_reg_state *regs) | |
6801 | { | |
6802 | struct bpf_prog *prog = env->prog; | |
6803 | struct btf *btf = prog->aux->btf; | |
6804 | bool is_global; | |
6805 | u32 btf_id; | |
6806 | int err; | |
6807 | ||
6808 | if (!prog->aux->func_info) | |
6809 | return -EINVAL; | |
6810 | ||
6811 | btf_id = prog->aux->func_info[subprog].type_id; | |
6812 | if (!btf_id) | |
6813 | return -EFAULT; | |
6814 | ||
6815 | if (prog->aux->func_info_aux[subprog].unreliable) | |
6816 | return -EINVAL; | |
6817 | ||
6818 | is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL; | |
00b85860 | 6819 | err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, true); |
34747c41 | 6820 | |
51c39bb1 AS |
6821 | /* Compiler optimizations can remove arguments from static functions |
6822 | * or mismatched type can be passed into a global function. | |
6823 | * In such cases mark the function as unreliable from BTF point of view. | |
6824 | */ | |
34747c41 MKL |
6825 | if (err) |
6826 | prog->aux->func_info_aux[subprog].unreliable = true; | |
6827 | return err; | |
51c39bb1 AS |
6828 | } |
6829 | ||
6830 | /* Convert BTF of a function into bpf_reg_state if possible | |
6831 | * Returns: | |
6832 | * EFAULT - there is a verifier bug. Abort verification. | |
6833 | * EINVAL - cannot convert BTF. | |
6834 | * 0 - Successfully converted BTF into bpf_reg_state | |
6835 | * (either PTR_TO_CTX or SCALAR_VALUE). | |
6836 | */ | |
6837 | int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog, | |
feb4adfa | 6838 | struct bpf_reg_state *regs) |
51c39bb1 AS |
6839 | { |
6840 | struct bpf_verifier_log *log = &env->log; | |
6841 | struct bpf_prog *prog = env->prog; | |
be8704ff | 6842 | enum bpf_prog_type prog_type = prog->type; |
51c39bb1 AS |
6843 | struct btf *btf = prog->aux->btf; |
6844 | const struct btf_param *args; | |
e5069b9c | 6845 | const struct btf_type *t, *ref_t; |
51c39bb1 AS |
6846 | u32 i, nargs, btf_id; |
6847 | const char *tname; | |
6848 | ||
6849 | if (!prog->aux->func_info || | |
6850 | prog->aux->func_info_aux[subprog].linkage != BTF_FUNC_GLOBAL) { | |
6851 | bpf_log(log, "Verifier bug\n"); | |
6852 | return -EFAULT; | |
6853 | } | |
6854 | ||
6855 | btf_id = prog->aux->func_info[subprog].type_id; | |
6856 | if (!btf_id) { | |
6857 | bpf_log(log, "Global functions need valid BTF\n"); | |
6858 | return -EFAULT; | |
6859 | } | |
6860 | ||
6861 | t = btf_type_by_id(btf, btf_id); | |
6862 | if (!t || !btf_type_is_func(t)) { | |
6863 | /* These checks were already done by the verifier while loading | |
6864 | * struct bpf_func_info | |
6865 | */ | |
6866 | bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n", | |
6867 | subprog); | |
6868 | return -EFAULT; | |
6869 | } | |
6870 | tname = btf_name_by_offset(btf, t->name_off); | |
6871 | ||
6872 | if (log->level & BPF_LOG_LEVEL) | |
6873 | bpf_log(log, "Validating %s() func#%d...\n", | |
6874 | tname, subprog); | |
6875 | ||
6876 | if (prog->aux->func_info_aux[subprog].unreliable) { | |
6877 | bpf_log(log, "Verifier bug in function %s()\n", tname); | |
6878 | return -EFAULT; | |
6879 | } | |
be8704ff | 6880 | if (prog_type == BPF_PROG_TYPE_EXT) |
3aac1ead | 6881 | prog_type = prog->aux->dst_prog->type; |
51c39bb1 AS |
6882 | |
6883 | t = btf_type_by_id(btf, t->type); | |
6884 | if (!t || !btf_type_is_func_proto(t)) { | |
6885 | bpf_log(log, "Invalid type of function %s()\n", tname); | |
6886 | return -EFAULT; | |
6887 | } | |
6888 | args = (const struct btf_param *)(t + 1); | |
6889 | nargs = btf_type_vlen(t); | |
523a4cf4 DB |
6890 | if (nargs > MAX_BPF_FUNC_REG_ARGS) { |
6891 | bpf_log(log, "Global function %s() with %d > %d args. Buggy compiler.\n", | |
6892 | tname, nargs, MAX_BPF_FUNC_REG_ARGS); | |
51c39bb1 AS |
6893 | return -EINVAL; |
6894 | } | |
6895 | /* check that function returns int */ | |
6896 | t = btf_type_by_id(btf, t->type); | |
6897 | while (btf_type_is_modifier(t)) | |
6898 | t = btf_type_by_id(btf, t->type); | |
6089fb32 | 6899 | if (!btf_type_is_int(t) && !btf_is_any_enum(t)) { |
51c39bb1 AS |
6900 | bpf_log(log, |
6901 | "Global function %s() doesn't return scalar. Only those are supported.\n", | |
6902 | tname); | |
6903 | return -EINVAL; | |
6904 | } | |
6905 | /* Convert BTF function arguments into verifier types. | |
6906 | * Only PTR_TO_CTX and SCALAR are supported atm. | |
6907 | */ | |
6908 | for (i = 0; i < nargs; i++) { | |
feb4adfa DB |
6909 | struct bpf_reg_state *reg = ®s[i + 1]; |
6910 | ||
51c39bb1 AS |
6911 | t = btf_type_by_id(btf, args[i].type); |
6912 | while (btf_type_is_modifier(t)) | |
6913 | t = btf_type_by_id(btf, t->type); | |
6089fb32 | 6914 | if (btf_type_is_int(t) || btf_is_any_enum(t)) { |
feb4adfa | 6915 | reg->type = SCALAR_VALUE; |
51c39bb1 AS |
6916 | continue; |
6917 | } | |
e5069b9c DB |
6918 | if (btf_type_is_ptr(t)) { |
6919 | if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) { | |
6920 | reg->type = PTR_TO_CTX; | |
6921 | continue; | |
6922 | } | |
6923 | ||
6924 | t = btf_type_skip_modifiers(btf, t->type, NULL); | |
6925 | ||
6926 | ref_t = btf_resolve_size(btf, t, ®->mem_size); | |
6927 | if (IS_ERR(ref_t)) { | |
6928 | bpf_log(log, | |
6929 | "arg#%d reference type('%s %s') size cannot be determined: %ld\n", | |
6930 | i, btf_type_str(t), btf_name_by_offset(btf, t->name_off), | |
6931 | PTR_ERR(ref_t)); | |
6932 | return -EINVAL; | |
6933 | } | |
6934 | ||
cf9f2f8d | 6935 | reg->type = PTR_TO_MEM | PTR_MAYBE_NULL; |
e5069b9c DB |
6936 | reg->id = ++env->id_gen; |
6937 | ||
51c39bb1 AS |
6938 | continue; |
6939 | } | |
6940 | bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n", | |
571f9738 | 6941 | i, btf_type_str(t), tname); |
51c39bb1 AS |
6942 | return -EINVAL; |
6943 | } | |
8c1b6e69 AS |
6944 | return 0; |
6945 | } | |
6946 | ||
31d0bc81 AM |
6947 | static void btf_type_show(const struct btf *btf, u32 type_id, void *obj, |
6948 | struct btf_show *show) | |
6949 | { | |
6950 | const struct btf_type *t = btf_type_by_id(btf, type_id); | |
6951 | ||
6952 | show->btf = btf; | |
6953 | memset(&show->state, 0, sizeof(show->state)); | |
6954 | memset(&show->obj, 0, sizeof(show->obj)); | |
6955 | ||
6956 | btf_type_ops(t)->show(btf, t, type_id, obj, 0, show); | |
6957 | } | |
6958 | ||
6959 | static void btf_seq_show(struct btf_show *show, const char *fmt, | |
6960 | va_list args) | |
6961 | { | |
6962 | seq_vprintf((struct seq_file *)show->target, fmt, args); | |
6963 | } | |
6964 | ||
eb411377 AM |
6965 | int btf_type_seq_show_flags(const struct btf *btf, u32 type_id, |
6966 | void *obj, struct seq_file *m, u64 flags) | |
31d0bc81 AM |
6967 | { |
6968 | struct btf_show sseq; | |
6969 | ||
6970 | sseq.target = m; | |
6971 | sseq.showfn = btf_seq_show; | |
6972 | sseq.flags = flags; | |
6973 | ||
6974 | btf_type_show(btf, type_id, obj, &sseq); | |
6975 | ||
6976 | return sseq.state.status; | |
6977 | } | |
6978 | ||
b00b8dae MKL |
6979 | void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj, |
6980 | struct seq_file *m) | |
6981 | { | |
31d0bc81 AM |
6982 | (void) btf_type_seq_show_flags(btf, type_id, obj, m, |
6983 | BTF_SHOW_NONAME | BTF_SHOW_COMPACT | | |
6984 | BTF_SHOW_ZERO | BTF_SHOW_UNSAFE); | |
6985 | } | |
6986 | ||
6987 | struct btf_show_snprintf { | |
6988 | struct btf_show show; | |
6989 | int len_left; /* space left in string */ | |
6990 | int len; /* length we would have written */ | |
6991 | }; | |
6992 | ||
6993 | static void btf_snprintf_show(struct btf_show *show, const char *fmt, | |
6994 | va_list args) | |
6995 | { | |
6996 | struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show; | |
6997 | int len; | |
6998 | ||
6999 | len = vsnprintf(show->target, ssnprintf->len_left, fmt, args); | |
7000 | ||
7001 | if (len < 0) { | |
7002 | ssnprintf->len_left = 0; | |
7003 | ssnprintf->len = len; | |
58250ae3 | 7004 | } else if (len >= ssnprintf->len_left) { |
31d0bc81 AM |
7005 | /* no space, drive on to get length we would have written */ |
7006 | ssnprintf->len_left = 0; | |
7007 | ssnprintf->len += len; | |
7008 | } else { | |
7009 | ssnprintf->len_left -= len; | |
7010 | ssnprintf->len += len; | |
7011 | show->target += len; | |
7012 | } | |
7013 | } | |
7014 | ||
7015 | int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj, | |
7016 | char *buf, int len, u64 flags) | |
7017 | { | |
7018 | struct btf_show_snprintf ssnprintf; | |
7019 | ||
7020 | ssnprintf.show.target = buf; | |
7021 | ssnprintf.show.flags = flags; | |
7022 | ssnprintf.show.showfn = btf_snprintf_show; | |
7023 | ssnprintf.len_left = len; | |
7024 | ssnprintf.len = 0; | |
7025 | ||
7026 | btf_type_show(btf, type_id, obj, (struct btf_show *)&ssnprintf); | |
7027 | ||
c561d110 | 7028 | /* If we encountered an error, return it. */ |
31d0bc81 AM |
7029 | if (ssnprintf.show.state.status) |
7030 | return ssnprintf.show.state.status; | |
b00b8dae | 7031 | |
31d0bc81 AM |
7032 | /* Otherwise return length we would have written */ |
7033 | return ssnprintf.len; | |
b00b8dae | 7034 | } |
f56a653c | 7035 | |
3481e64b QM |
7036 | #ifdef CONFIG_PROC_FS |
7037 | static void bpf_btf_show_fdinfo(struct seq_file *m, struct file *filp) | |
7038 | { | |
7039 | const struct btf *btf = filp->private_data; | |
7040 | ||
7041 | seq_printf(m, "btf_id:\t%u\n", btf->id); | |
7042 | } | |
7043 | #endif | |
7044 | ||
f56a653c MKL |
7045 | static int btf_release(struct inode *inode, struct file *filp) |
7046 | { | |
7047 | btf_put(filp->private_data); | |
7048 | return 0; | |
7049 | } | |
7050 | ||
60197cfb | 7051 | const struct file_operations btf_fops = { |
3481e64b QM |
7052 | #ifdef CONFIG_PROC_FS |
7053 | .show_fdinfo = bpf_btf_show_fdinfo, | |
7054 | #endif | |
f56a653c MKL |
7055 | .release = btf_release, |
7056 | }; | |
7057 | ||
78958fca MKL |
7058 | static int __btf_new_fd(struct btf *btf) |
7059 | { | |
7060 | return anon_inode_getfd("btf", &btf_fops, btf, O_RDONLY | O_CLOEXEC); | |
7061 | } | |
7062 | ||
c571bd75 | 7063 | int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr) |
f56a653c MKL |
7064 | { |
7065 | struct btf *btf; | |
78958fca | 7066 | int ret; |
f56a653c | 7067 | |
c571bd75 | 7068 | btf = btf_parse(make_bpfptr(attr->btf, uattr.is_kernel), |
f56a653c MKL |
7069 | attr->btf_size, attr->btf_log_level, |
7070 | u64_to_user_ptr(attr->btf_log_buf), | |
7071 | attr->btf_log_size); | |
7072 | if (IS_ERR(btf)) | |
7073 | return PTR_ERR(btf); | |
7074 | ||
78958fca MKL |
7075 | ret = btf_alloc_id(btf); |
7076 | if (ret) { | |
7077 | btf_free(btf); | |
7078 | return ret; | |
7079 | } | |
7080 | ||
7081 | /* | |
7082 | * The BTF ID is published to the userspace. | |
7083 | * All BTF free must go through call_rcu() from | |
7084 | * now on (i.e. free by calling btf_put()). | |
7085 | */ | |
7086 | ||
7087 | ret = __btf_new_fd(btf); | |
7088 | if (ret < 0) | |
f56a653c MKL |
7089 | btf_put(btf); |
7090 | ||
78958fca | 7091 | return ret; |
f56a653c MKL |
7092 | } |
7093 | ||
7094 | struct btf *btf_get_by_fd(int fd) | |
7095 | { | |
7096 | struct btf *btf; | |
7097 | struct fd f; | |
7098 | ||
7099 | f = fdget(fd); | |
7100 | ||
7101 | if (!f.file) | |
7102 | return ERR_PTR(-EBADF); | |
7103 | ||
7104 | if (f.file->f_op != &btf_fops) { | |
7105 | fdput(f); | |
7106 | return ERR_PTR(-EINVAL); | |
7107 | } | |
7108 | ||
7109 | btf = f.file->private_data; | |
78958fca | 7110 | refcount_inc(&btf->refcnt); |
f56a653c MKL |
7111 | fdput(f); |
7112 | ||
7113 | return btf; | |
7114 | } | |
60197cfb MKL |
7115 | |
7116 | int btf_get_info_by_fd(const struct btf *btf, | |
7117 | const union bpf_attr *attr, | |
7118 | union bpf_attr __user *uattr) | |
7119 | { | |
62dab84c | 7120 | struct bpf_btf_info __user *uinfo; |
5c6f2588 | 7121 | struct bpf_btf_info info; |
62dab84c MKL |
7122 | u32 info_copy, btf_copy; |
7123 | void __user *ubtf; | |
53297220 AN |
7124 | char __user *uname; |
7125 | u32 uinfo_len, uname_len, name_len; | |
7126 | int ret = 0; | |
60197cfb | 7127 | |
62dab84c MKL |
7128 | uinfo = u64_to_user_ptr(attr->info.info); |
7129 | uinfo_len = attr->info.info_len; | |
7130 | ||
7131 | info_copy = min_t(u32, uinfo_len, sizeof(info)); | |
5c6f2588 | 7132 | memset(&info, 0, sizeof(info)); |
62dab84c MKL |
7133 | if (copy_from_user(&info, uinfo, info_copy)) |
7134 | return -EFAULT; | |
7135 | ||
7136 | info.id = btf->id; | |
7137 | ubtf = u64_to_user_ptr(info.btf); | |
7138 | btf_copy = min_t(u32, btf->data_size, info.btf_size); | |
7139 | if (copy_to_user(ubtf, btf->data, btf_copy)) | |
7140 | return -EFAULT; | |
7141 | info.btf_size = btf->data_size; | |
7142 | ||
53297220 AN |
7143 | info.kernel_btf = btf->kernel_btf; |
7144 | ||
7145 | uname = u64_to_user_ptr(info.name); | |
7146 | uname_len = info.name_len; | |
7147 | if (!uname ^ !uname_len) | |
7148 | return -EINVAL; | |
7149 | ||
7150 | name_len = strlen(btf->name); | |
7151 | info.name_len = name_len; | |
7152 | ||
7153 | if (uname) { | |
7154 | if (uname_len >= name_len + 1) { | |
7155 | if (copy_to_user(uname, btf->name, name_len + 1)) | |
7156 | return -EFAULT; | |
7157 | } else { | |
7158 | char zero = '\0'; | |
7159 | ||
7160 | if (copy_to_user(uname, btf->name, uname_len - 1)) | |
7161 | return -EFAULT; | |
7162 | if (put_user(zero, uname + uname_len - 1)) | |
7163 | return -EFAULT; | |
7164 | /* let user-space know about too short buffer */ | |
7165 | ret = -ENOSPC; | |
7166 | } | |
7167 | } | |
7168 | ||
62dab84c MKL |
7169 | if (copy_to_user(uinfo, &info, info_copy) || |
7170 | put_user(info_copy, &uattr->info.info_len)) | |
60197cfb MKL |
7171 | return -EFAULT; |
7172 | ||
53297220 | 7173 | return ret; |
60197cfb | 7174 | } |
78958fca MKL |
7175 | |
7176 | int btf_get_fd_by_id(u32 id) | |
7177 | { | |
7178 | struct btf *btf; | |
7179 | int fd; | |
7180 | ||
7181 | rcu_read_lock(); | |
7182 | btf = idr_find(&btf_idr, id); | |
7183 | if (!btf || !refcount_inc_not_zero(&btf->refcnt)) | |
7184 | btf = ERR_PTR(-ENOENT); | |
7185 | rcu_read_unlock(); | |
7186 | ||
7187 | if (IS_ERR(btf)) | |
7188 | return PTR_ERR(btf); | |
7189 | ||
7190 | fd = __btf_new_fd(btf); | |
7191 | if (fd < 0) | |
7192 | btf_put(btf); | |
7193 | ||
7194 | return fd; | |
7195 | } | |
7196 | ||
22dc4a0f | 7197 | u32 btf_obj_id(const struct btf *btf) |
78958fca MKL |
7198 | { |
7199 | return btf->id; | |
7200 | } | |
eae2e83e | 7201 | |
290248a5 AN |
7202 | bool btf_is_kernel(const struct btf *btf) |
7203 | { | |
7204 | return btf->kernel_btf; | |
7205 | } | |
7206 | ||
541c3bad AN |
7207 | bool btf_is_module(const struct btf *btf) |
7208 | { | |
7209 | return btf->kernel_btf && strcmp(btf->name, "vmlinux") != 0; | |
7210 | } | |
7211 | ||
18688de2 KKD |
7212 | enum { |
7213 | BTF_MODULE_F_LIVE = (1 << 0), | |
7214 | }; | |
7215 | ||
36e68442 AN |
7216 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
7217 | struct btf_module { | |
7218 | struct list_head list; | |
7219 | struct module *module; | |
7220 | struct btf *btf; | |
7221 | struct bin_attribute *sysfs_attr; | |
18688de2 | 7222 | int flags; |
36e68442 AN |
7223 | }; |
7224 | ||
7225 | static LIST_HEAD(btf_modules); | |
7226 | static DEFINE_MUTEX(btf_module_mutex); | |
7227 | ||
7228 | static ssize_t | |
7229 | btf_module_read(struct file *file, struct kobject *kobj, | |
7230 | struct bin_attribute *bin_attr, | |
7231 | char *buf, loff_t off, size_t len) | |
7232 | { | |
7233 | const struct btf *btf = bin_attr->private; | |
7234 | ||
7235 | memcpy(buf, btf->data + off, len); | |
7236 | return len; | |
7237 | } | |
7238 | ||
1e89106d AS |
7239 | static void purge_cand_cache(struct btf *btf); |
7240 | ||
36e68442 AN |
7241 | static int btf_module_notify(struct notifier_block *nb, unsigned long op, |
7242 | void *module) | |
7243 | { | |
7244 | struct btf_module *btf_mod, *tmp; | |
7245 | struct module *mod = module; | |
7246 | struct btf *btf; | |
7247 | int err = 0; | |
7248 | ||
7249 | if (mod->btf_data_size == 0 || | |
18688de2 KKD |
7250 | (op != MODULE_STATE_COMING && op != MODULE_STATE_LIVE && |
7251 | op != MODULE_STATE_GOING)) | |
36e68442 AN |
7252 | goto out; |
7253 | ||
7254 | switch (op) { | |
7255 | case MODULE_STATE_COMING: | |
7256 | btf_mod = kzalloc(sizeof(*btf_mod), GFP_KERNEL); | |
7257 | if (!btf_mod) { | |
7258 | err = -ENOMEM; | |
7259 | goto out; | |
7260 | } | |
7261 | btf = btf_parse_module(mod->name, mod->btf_data, mod->btf_data_size); | |
7262 | if (IS_ERR(btf)) { | |
7263 | pr_warn("failed to validate module [%s] BTF: %ld\n", | |
7264 | mod->name, PTR_ERR(btf)); | |
7265 | kfree(btf_mod); | |
5e214f2e CB |
7266 | if (!IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) |
7267 | err = PTR_ERR(btf); | |
36e68442 AN |
7268 | goto out; |
7269 | } | |
7270 | err = btf_alloc_id(btf); | |
7271 | if (err) { | |
7272 | btf_free(btf); | |
7273 | kfree(btf_mod); | |
7274 | goto out; | |
7275 | } | |
7276 | ||
1e89106d | 7277 | purge_cand_cache(NULL); |
36e68442 AN |
7278 | mutex_lock(&btf_module_mutex); |
7279 | btf_mod->module = module; | |
7280 | btf_mod->btf = btf; | |
7281 | list_add(&btf_mod->list, &btf_modules); | |
7282 | mutex_unlock(&btf_module_mutex); | |
7283 | ||
7284 | if (IS_ENABLED(CONFIG_SYSFS)) { | |
7285 | struct bin_attribute *attr; | |
7286 | ||
7287 | attr = kzalloc(sizeof(*attr), GFP_KERNEL); | |
7288 | if (!attr) | |
7289 | goto out; | |
7290 | ||
7291 | sysfs_bin_attr_init(attr); | |
7292 | attr->attr.name = btf->name; | |
7293 | attr->attr.mode = 0444; | |
7294 | attr->size = btf->data_size; | |
7295 | attr->private = btf; | |
7296 | attr->read = btf_module_read; | |
7297 | ||
7298 | err = sysfs_create_bin_file(btf_kobj, attr); | |
7299 | if (err) { | |
7300 | pr_warn("failed to register module [%s] BTF in sysfs: %d\n", | |
7301 | mod->name, err); | |
7302 | kfree(attr); | |
7303 | err = 0; | |
7304 | goto out; | |
7305 | } | |
7306 | ||
7307 | btf_mod->sysfs_attr = attr; | |
7308 | } | |
7309 | ||
18688de2 KKD |
7310 | break; |
7311 | case MODULE_STATE_LIVE: | |
7312 | mutex_lock(&btf_module_mutex); | |
7313 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
7314 | if (btf_mod->module != module) | |
7315 | continue; | |
7316 | ||
7317 | btf_mod->flags |= BTF_MODULE_F_LIVE; | |
7318 | break; | |
7319 | } | |
7320 | mutex_unlock(&btf_module_mutex); | |
36e68442 AN |
7321 | break; |
7322 | case MODULE_STATE_GOING: | |
7323 | mutex_lock(&btf_module_mutex); | |
7324 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
7325 | if (btf_mod->module != module) | |
7326 | continue; | |
7327 | ||
7328 | list_del(&btf_mod->list); | |
7329 | if (btf_mod->sysfs_attr) | |
7330 | sysfs_remove_bin_file(btf_kobj, btf_mod->sysfs_attr); | |
1e89106d | 7331 | purge_cand_cache(btf_mod->btf); |
36e68442 AN |
7332 | btf_put(btf_mod->btf); |
7333 | kfree(btf_mod->sysfs_attr); | |
7334 | kfree(btf_mod); | |
7335 | break; | |
7336 | } | |
7337 | mutex_unlock(&btf_module_mutex); | |
7338 | break; | |
7339 | } | |
7340 | out: | |
7341 | return notifier_from_errno(err); | |
7342 | } | |
7343 | ||
7344 | static struct notifier_block btf_module_nb = { | |
7345 | .notifier_call = btf_module_notify, | |
7346 | }; | |
7347 | ||
7348 | static int __init btf_module_init(void) | |
7349 | { | |
7350 | register_module_notifier(&btf_module_nb); | |
7351 | return 0; | |
7352 | } | |
7353 | ||
7354 | fs_initcall(btf_module_init); | |
7355 | #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */ | |
541c3bad AN |
7356 | |
7357 | struct module *btf_try_get_module(const struct btf *btf) | |
7358 | { | |
7359 | struct module *res = NULL; | |
7360 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES | |
7361 | struct btf_module *btf_mod, *tmp; | |
7362 | ||
7363 | mutex_lock(&btf_module_mutex); | |
7364 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
7365 | if (btf_mod->btf != btf) | |
7366 | continue; | |
7367 | ||
18688de2 KKD |
7368 | /* We must only consider module whose __init routine has |
7369 | * finished, hence we must check for BTF_MODULE_F_LIVE flag, | |
7370 | * which is set from the notifier callback for | |
7371 | * MODULE_STATE_LIVE. | |
7372 | */ | |
7373 | if ((btf_mod->flags & BTF_MODULE_F_LIVE) && try_module_get(btf_mod->module)) | |
541c3bad AN |
7374 | res = btf_mod->module; |
7375 | ||
7376 | break; | |
7377 | } | |
7378 | mutex_unlock(&btf_module_mutex); | |
7379 | #endif | |
7380 | ||
7381 | return res; | |
7382 | } | |
3d78417b | 7383 | |
9492450f KKD |
7384 | /* Returns struct btf corresponding to the struct module. |
7385 | * This function can return NULL or ERR_PTR. | |
dee872e1 KKD |
7386 | */ |
7387 | static struct btf *btf_get_module_btf(const struct module *module) | |
7388 | { | |
dee872e1 KKD |
7389 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
7390 | struct btf_module *btf_mod, *tmp; | |
7391 | #endif | |
9492450f KKD |
7392 | struct btf *btf = NULL; |
7393 | ||
7394 | if (!module) { | |
7395 | btf = bpf_get_btf_vmlinux(); | |
7ada3787 | 7396 | if (!IS_ERR_OR_NULL(btf)) |
9492450f KKD |
7397 | btf_get(btf); |
7398 | return btf; | |
7399 | } | |
dee872e1 | 7400 | |
dee872e1 KKD |
7401 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
7402 | mutex_lock(&btf_module_mutex); | |
7403 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
7404 | if (btf_mod->module != module) | |
7405 | continue; | |
7406 | ||
7407 | btf_get(btf_mod->btf); | |
7408 | btf = btf_mod->btf; | |
7409 | break; | |
7410 | } | |
7411 | mutex_unlock(&btf_module_mutex); | |
7412 | #endif | |
7413 | ||
7414 | return btf; | |
7415 | } | |
7416 | ||
3d78417b AS |
7417 | BPF_CALL_4(bpf_btf_find_by_name_kind, char *, name, int, name_sz, u32, kind, int, flags) |
7418 | { | |
edc3ec09 KKD |
7419 | struct btf *btf = NULL; |
7420 | int btf_obj_fd = 0; | |
3d78417b AS |
7421 | long ret; |
7422 | ||
7423 | if (flags) | |
7424 | return -EINVAL; | |
7425 | ||
7426 | if (name_sz <= 1 || name[name_sz - 1]) | |
7427 | return -EINVAL; | |
7428 | ||
edc3ec09 KKD |
7429 | ret = bpf_find_btf_id(name, kind, &btf); |
7430 | if (ret > 0 && btf_is_module(btf)) { | |
7431 | btf_obj_fd = __btf_new_fd(btf); | |
7432 | if (btf_obj_fd < 0) { | |
7433 | btf_put(btf); | |
7434 | return btf_obj_fd; | |
3d78417b | 7435 | } |
edc3ec09 | 7436 | return ret | (((u64)btf_obj_fd) << 32); |
3d78417b | 7437 | } |
edc3ec09 KKD |
7438 | if (ret > 0) |
7439 | btf_put(btf); | |
3d78417b AS |
7440 | return ret; |
7441 | } | |
7442 | ||
7443 | const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = { | |
7444 | .func = bpf_btf_find_by_name_kind, | |
7445 | .gpl_only = false, | |
7446 | .ret_type = RET_INTEGER, | |
216e3cd2 | 7447 | .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
3d78417b AS |
7448 | .arg2_type = ARG_CONST_SIZE, |
7449 | .arg3_type = ARG_ANYTHING, | |
7450 | .arg4_type = ARG_ANYTHING, | |
7451 | }; | |
eb529c5b | 7452 | |
d19ddb47 SL |
7453 | BTF_ID_LIST_GLOBAL(btf_tracing_ids, MAX_BTF_TRACING_TYPE) |
7454 | #define BTF_TRACING_TYPE(name, type) BTF_ID(struct, type) | |
7455 | BTF_TRACING_TYPE_xxx | |
7456 | #undef BTF_TRACING_TYPE | |
14f267d9 | 7457 | |
dee872e1 | 7458 | /* Kernel Function (kfunc) BTF ID set registration API */ |
14f267d9 | 7459 | |
a4703e31 KKD |
7460 | static int btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, |
7461 | struct btf_id_set8 *add_set) | |
14f267d9 | 7462 | { |
a4703e31 | 7463 | bool vmlinux_set = !btf_is_module(btf); |
dee872e1 | 7464 | struct btf_kfunc_set_tab *tab; |
a4703e31 | 7465 | struct btf_id_set8 *set; |
dee872e1 KKD |
7466 | u32 set_cnt; |
7467 | int ret; | |
7468 | ||
a4703e31 | 7469 | if (hook >= BTF_KFUNC_HOOK_MAX) { |
dee872e1 KKD |
7470 | ret = -EINVAL; |
7471 | goto end; | |
7472 | } | |
7473 | ||
7474 | if (!add_set->cnt) | |
7475 | return 0; | |
7476 | ||
7477 | tab = btf->kfunc_set_tab; | |
7478 | if (!tab) { | |
7479 | tab = kzalloc(sizeof(*tab), GFP_KERNEL | __GFP_NOWARN); | |
7480 | if (!tab) | |
7481 | return -ENOMEM; | |
7482 | btf->kfunc_set_tab = tab; | |
7483 | } | |
7484 | ||
a4703e31 | 7485 | set = tab->sets[hook]; |
dee872e1 KKD |
7486 | /* Warn when register_btf_kfunc_id_set is called twice for the same hook |
7487 | * for module sets. | |
7488 | */ | |
7489 | if (WARN_ON_ONCE(set && !vmlinux_set)) { | |
7490 | ret = -EINVAL; | |
7491 | goto end; | |
7492 | } | |
7493 | ||
7494 | /* We don't need to allocate, concatenate, and sort module sets, because | |
7495 | * only one is allowed per hook. Hence, we can directly assign the | |
7496 | * pointer and return. | |
7497 | */ | |
7498 | if (!vmlinux_set) { | |
a4703e31 | 7499 | tab->sets[hook] = add_set; |
dee872e1 KKD |
7500 | return 0; |
7501 | } | |
7502 | ||
7503 | /* In case of vmlinux sets, there may be more than one set being | |
7504 | * registered per hook. To create a unified set, we allocate a new set | |
7505 | * and concatenate all individual sets being registered. While each set | |
7506 | * is individually sorted, they may become unsorted when concatenated, | |
7507 | * hence re-sorting the final set again is required to make binary | |
a4703e31 | 7508 | * searching the set using btf_id_set8_contains function work. |
dee872e1 KKD |
7509 | */ |
7510 | set_cnt = set ? set->cnt : 0; | |
7511 | ||
7512 | if (set_cnt > U32_MAX - add_set->cnt) { | |
7513 | ret = -EOVERFLOW; | |
7514 | goto end; | |
7515 | } | |
7516 | ||
7517 | if (set_cnt + add_set->cnt > BTF_KFUNC_SET_MAX_CNT) { | |
7518 | ret = -E2BIG; | |
7519 | goto end; | |
7520 | } | |
7521 | ||
7522 | /* Grow set */ | |
a4703e31 KKD |
7523 | set = krealloc(tab->sets[hook], |
7524 | offsetof(struct btf_id_set8, pairs[set_cnt + add_set->cnt]), | |
dee872e1 KKD |
7525 | GFP_KERNEL | __GFP_NOWARN); |
7526 | if (!set) { | |
7527 | ret = -ENOMEM; | |
7528 | goto end; | |
7529 | } | |
7530 | ||
7531 | /* For newly allocated set, initialize set->cnt to 0 */ | |
a4703e31 | 7532 | if (!tab->sets[hook]) |
dee872e1 | 7533 | set->cnt = 0; |
a4703e31 | 7534 | tab->sets[hook] = set; |
dee872e1 KKD |
7535 | |
7536 | /* Concatenate the two sets */ | |
a4703e31 | 7537 | memcpy(set->pairs + set->cnt, add_set->pairs, add_set->cnt * sizeof(set->pairs[0])); |
dee872e1 KKD |
7538 | set->cnt += add_set->cnt; |
7539 | ||
a4703e31 | 7540 | sort(set->pairs, set->cnt, sizeof(set->pairs[0]), btf_id_cmp_func, NULL); |
dee872e1 KKD |
7541 | |
7542 | return 0; | |
7543 | end: | |
7544 | btf_free_kfunc_set_tab(btf); | |
7545 | return ret; | |
14f267d9 | 7546 | } |
14f267d9 | 7547 | |
a4703e31 | 7548 | static u32 *__btf_kfunc_id_set_contains(const struct btf *btf, |
dee872e1 | 7549 | enum btf_kfunc_hook hook, |
dee872e1 | 7550 | u32 kfunc_btf_id) |
14f267d9 | 7551 | { |
a4703e31 KKD |
7552 | struct btf_id_set8 *set; |
7553 | u32 *id; | |
14f267d9 | 7554 | |
a4703e31 KKD |
7555 | if (hook >= BTF_KFUNC_HOOK_MAX) |
7556 | return NULL; | |
dee872e1 | 7557 | if (!btf->kfunc_set_tab) |
a4703e31 KKD |
7558 | return NULL; |
7559 | set = btf->kfunc_set_tab->sets[hook]; | |
dee872e1 | 7560 | if (!set) |
a4703e31 KKD |
7561 | return NULL; |
7562 | id = btf_id_set8_contains(set, kfunc_btf_id); | |
7563 | if (!id) | |
7564 | return NULL; | |
7565 | /* The flags for BTF ID are located next to it */ | |
7566 | return id + 1; | |
dee872e1 KKD |
7567 | } |
7568 | ||
7569 | static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type) | |
7570 | { | |
7571 | switch (prog_type) { | |
cfe14564 YS |
7572 | case BPF_PROG_TYPE_UNSPEC: |
7573 | return BTF_KFUNC_HOOK_COMMON; | |
dee872e1 KKD |
7574 | case BPF_PROG_TYPE_XDP: |
7575 | return BTF_KFUNC_HOOK_XDP; | |
7576 | case BPF_PROG_TYPE_SCHED_CLS: | |
7577 | return BTF_KFUNC_HOOK_TC; | |
7578 | case BPF_PROG_TYPE_STRUCT_OPS: | |
7579 | return BTF_KFUNC_HOOK_STRUCT_OPS; | |
97949767 | 7580 | case BPF_PROG_TYPE_TRACING: |
d15bf150 | 7581 | case BPF_PROG_TYPE_LSM: |
97949767 BT |
7582 | return BTF_KFUNC_HOOK_TRACING; |
7583 | case BPF_PROG_TYPE_SYSCALL: | |
7584 | return BTF_KFUNC_HOOK_SYSCALL; | |
dee872e1 KKD |
7585 | default: |
7586 | return BTF_KFUNC_HOOK_MAX; | |
14f267d9 | 7587 | } |
14f267d9 KKD |
7588 | } |
7589 | ||
dee872e1 KKD |
7590 | /* Caution: |
7591 | * Reference to the module (obtained using btf_try_get_module) corresponding to | |
7592 | * the struct btf *MUST* be held when calling this function from verifier | |
7593 | * context. This is usually true as we stash references in prog's kfunc_btf_tab; | |
7594 | * keeping the reference for the duration of the call provides the necessary | |
7595 | * protection for looking up a well-formed btf->kfunc_set_tab. | |
7596 | */ | |
a4703e31 | 7597 | u32 *btf_kfunc_id_set_contains(const struct btf *btf, |
dee872e1 | 7598 | enum bpf_prog_type prog_type, |
a4703e31 | 7599 | u32 kfunc_btf_id) |
dee872e1 KKD |
7600 | { |
7601 | enum btf_kfunc_hook hook; | |
cfe14564 YS |
7602 | u32 *kfunc_flags; |
7603 | ||
7604 | kfunc_flags = __btf_kfunc_id_set_contains(btf, BTF_KFUNC_HOOK_COMMON, kfunc_btf_id); | |
7605 | if (kfunc_flags) | |
7606 | return kfunc_flags; | |
0e32dfc8 | 7607 | |
dee872e1 | 7608 | hook = bpf_prog_type_to_kfunc_hook(prog_type); |
a4703e31 | 7609 | return __btf_kfunc_id_set_contains(btf, hook, kfunc_btf_id); |
dee872e1 | 7610 | } |
d9847eb8 | 7611 | |
5b481aca BT |
7612 | u32 *btf_kfunc_is_modify_return(const struct btf *btf, u32 kfunc_btf_id) |
7613 | { | |
7614 | return __btf_kfunc_id_set_contains(btf, BTF_KFUNC_HOOK_FMODRET, kfunc_btf_id); | |
7615 | } | |
7616 | ||
7617 | static int __register_btf_kfunc_id_set(enum btf_kfunc_hook hook, | |
7618 | const struct btf_kfunc_id_set *kset) | |
dee872e1 | 7619 | { |
dee872e1 KKD |
7620 | struct btf *btf; |
7621 | int ret; | |
7622 | ||
7623 | btf = btf_get_module_btf(kset->owner); | |
c446fdac SF |
7624 | if (!btf) { |
7625 | if (!kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) { | |
7626 | pr_err("missing vmlinux BTF, cannot register kfuncs\n"); | |
7627 | return -ENOENT; | |
7628 | } | |
7629 | if (kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) { | |
7630 | pr_err("missing module BTF, cannot register kfuncs\n"); | |
7631 | return -ENOENT; | |
7632 | } | |
7633 | return 0; | |
7634 | } | |
7635 | if (IS_ERR(btf)) | |
7636 | return PTR_ERR(btf); | |
dee872e1 | 7637 | |
a4703e31 | 7638 | ret = btf_populate_kfunc_set(btf, hook, kset->set); |
9492450f | 7639 | btf_put(btf); |
dee872e1 KKD |
7640 | return ret; |
7641 | } | |
5b481aca BT |
7642 | |
7643 | /* This function must be invoked only from initcalls/module init functions */ | |
7644 | int register_btf_kfunc_id_set(enum bpf_prog_type prog_type, | |
7645 | const struct btf_kfunc_id_set *kset) | |
7646 | { | |
7647 | enum btf_kfunc_hook hook; | |
7648 | ||
7649 | hook = bpf_prog_type_to_kfunc_hook(prog_type); | |
7650 | return __register_btf_kfunc_id_set(hook, kset); | |
7651 | } | |
dee872e1 | 7652 | EXPORT_SYMBOL_GPL(register_btf_kfunc_id_set); |
be315829 | 7653 | |
5b481aca BT |
7654 | /* This function must be invoked only from initcalls/module init functions */ |
7655 | int register_btf_fmodret_id_set(const struct btf_kfunc_id_set *kset) | |
7656 | { | |
7657 | return __register_btf_kfunc_id_set(BTF_KFUNC_HOOK_FMODRET, kset); | |
7658 | } | |
7659 | EXPORT_SYMBOL_GPL(register_btf_fmodret_id_set); | |
7660 | ||
5ce937d6 KKD |
7661 | s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id) |
7662 | { | |
7663 | struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab; | |
7664 | struct btf_id_dtor_kfunc *dtor; | |
7665 | ||
7666 | if (!tab) | |
7667 | return -ENOENT; | |
7668 | /* Even though the size of tab->dtors[0] is > sizeof(u32), we only need | |
7669 | * to compare the first u32 with btf_id, so we can reuse btf_id_cmp_func. | |
7670 | */ | |
7671 | BUILD_BUG_ON(offsetof(struct btf_id_dtor_kfunc, btf_id) != 0); | |
7672 | dtor = bsearch(&btf_id, tab->dtors, tab->cnt, sizeof(tab->dtors[0]), btf_id_cmp_func); | |
7673 | if (!dtor) | |
7674 | return -ENOENT; | |
7675 | return dtor->kfunc_btf_id; | |
7676 | } | |
7677 | ||
14a324f6 KKD |
7678 | static int btf_check_dtor_kfuncs(struct btf *btf, const struct btf_id_dtor_kfunc *dtors, u32 cnt) |
7679 | { | |
7680 | const struct btf_type *dtor_func, *dtor_func_proto, *t; | |
7681 | const struct btf_param *args; | |
7682 | s32 dtor_btf_id; | |
7683 | u32 nr_args, i; | |
7684 | ||
7685 | for (i = 0; i < cnt; i++) { | |
7686 | dtor_btf_id = dtors[i].kfunc_btf_id; | |
7687 | ||
7688 | dtor_func = btf_type_by_id(btf, dtor_btf_id); | |
7689 | if (!dtor_func || !btf_type_is_func(dtor_func)) | |
7690 | return -EINVAL; | |
7691 | ||
7692 | dtor_func_proto = btf_type_by_id(btf, dtor_func->type); | |
7693 | if (!dtor_func_proto || !btf_type_is_func_proto(dtor_func_proto)) | |
7694 | return -EINVAL; | |
7695 | ||
7696 | /* Make sure the prototype of the destructor kfunc is 'void func(type *)' */ | |
7697 | t = btf_type_by_id(btf, dtor_func_proto->type); | |
7698 | if (!t || !btf_type_is_void(t)) | |
7699 | return -EINVAL; | |
7700 | ||
7701 | nr_args = btf_type_vlen(dtor_func_proto); | |
7702 | if (nr_args != 1) | |
7703 | return -EINVAL; | |
7704 | args = btf_params(dtor_func_proto); | |
7705 | t = btf_type_by_id(btf, args[0].type); | |
7706 | /* Allow any pointer type, as width on targets Linux supports | |
7707 | * will be same for all pointer types (i.e. sizeof(void *)) | |
7708 | */ | |
7709 | if (!t || !btf_type_is_ptr(t)) | |
7710 | return -EINVAL; | |
7711 | } | |
7712 | return 0; | |
7713 | } | |
7714 | ||
5ce937d6 KKD |
7715 | /* This function must be invoked only from initcalls/module init functions */ |
7716 | int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_cnt, | |
7717 | struct module *owner) | |
7718 | { | |
7719 | struct btf_id_dtor_kfunc_tab *tab; | |
7720 | struct btf *btf; | |
7721 | u32 tab_cnt; | |
7722 | int ret; | |
7723 | ||
7724 | btf = btf_get_module_btf(owner); | |
7725 | if (!btf) { | |
7726 | if (!owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) { | |
7727 | pr_err("missing vmlinux BTF, cannot register dtor kfuncs\n"); | |
7728 | return -ENOENT; | |
7729 | } | |
7730 | if (owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) { | |
7731 | pr_err("missing module BTF, cannot register dtor kfuncs\n"); | |
7732 | return -ENOENT; | |
7733 | } | |
7734 | return 0; | |
7735 | } | |
7736 | if (IS_ERR(btf)) | |
7737 | return PTR_ERR(btf); | |
7738 | ||
7739 | if (add_cnt >= BTF_DTOR_KFUNC_MAX_CNT) { | |
7740 | pr_err("cannot register more than %d kfunc destructors\n", BTF_DTOR_KFUNC_MAX_CNT); | |
7741 | ret = -E2BIG; | |
7742 | goto end; | |
7743 | } | |
7744 | ||
14a324f6 KKD |
7745 | /* Ensure that the prototype of dtor kfuncs being registered is sane */ |
7746 | ret = btf_check_dtor_kfuncs(btf, dtors, add_cnt); | |
7747 | if (ret < 0) | |
7748 | goto end; | |
7749 | ||
5ce937d6 KKD |
7750 | tab = btf->dtor_kfunc_tab; |
7751 | /* Only one call allowed for modules */ | |
7752 | if (WARN_ON_ONCE(tab && btf_is_module(btf))) { | |
7753 | ret = -EINVAL; | |
7754 | goto end; | |
7755 | } | |
7756 | ||
7757 | tab_cnt = tab ? tab->cnt : 0; | |
7758 | if (tab_cnt > U32_MAX - add_cnt) { | |
7759 | ret = -EOVERFLOW; | |
7760 | goto end; | |
7761 | } | |
7762 | if (tab_cnt + add_cnt >= BTF_DTOR_KFUNC_MAX_CNT) { | |
7763 | pr_err("cannot register more than %d kfunc destructors\n", BTF_DTOR_KFUNC_MAX_CNT); | |
7764 | ret = -E2BIG; | |
7765 | goto end; | |
7766 | } | |
7767 | ||
7768 | tab = krealloc(btf->dtor_kfunc_tab, | |
7769 | offsetof(struct btf_id_dtor_kfunc_tab, dtors[tab_cnt + add_cnt]), | |
7770 | GFP_KERNEL | __GFP_NOWARN); | |
7771 | if (!tab) { | |
7772 | ret = -ENOMEM; | |
7773 | goto end; | |
7774 | } | |
7775 | ||
7776 | if (!btf->dtor_kfunc_tab) | |
7777 | tab->cnt = 0; | |
7778 | btf->dtor_kfunc_tab = tab; | |
7779 | ||
7780 | memcpy(tab->dtors + tab->cnt, dtors, add_cnt * sizeof(tab->dtors[0])); | |
7781 | tab->cnt += add_cnt; | |
7782 | ||
7783 | sort(tab->dtors, tab->cnt, sizeof(tab->dtors[0]), btf_id_cmp_func, NULL); | |
7784 | ||
7785 | return 0; | |
7786 | end: | |
7787 | btf_free_dtor_kfunc_tab(btf); | |
7788 | btf_put(btf); | |
7789 | return ret; | |
7790 | } | |
7791 | EXPORT_SYMBOL_GPL(register_btf_id_dtor_kfuncs); | |
7792 | ||
e70e13e7 MC |
7793 | #define MAX_TYPES_ARE_COMPAT_DEPTH 2 |
7794 | ||
e70e13e7 MC |
7795 | /* Check local and target types for compatibility. This check is used for |
7796 | * type-based CO-RE relocations and follow slightly different rules than | |
7797 | * field-based relocations. This function assumes that root types were already | |
7798 | * checked for name match. Beyond that initial root-level name check, names | |
7799 | * are completely ignored. Compatibility rules are as follows: | |
6089fb32 | 7800 | * - any two STRUCTs/UNIONs/FWDs/ENUMs/INTs/ENUM64s are considered compatible, but |
e70e13e7 MC |
7801 | * kind should match for local and target types (i.e., STRUCT is not |
7802 | * compatible with UNION); | |
6089fb32 | 7803 | * - for ENUMs/ENUM64s, the size is ignored; |
e70e13e7 MC |
7804 | * - for INT, size and signedness are ignored; |
7805 | * - for ARRAY, dimensionality is ignored, element types are checked for | |
7806 | * compatibility recursively; | |
7807 | * - CONST/VOLATILE/RESTRICT modifiers are ignored; | |
7808 | * - TYPEDEFs/PTRs are compatible if types they pointing to are compatible; | |
7809 | * - FUNC_PROTOs are compatible if they have compatible signature: same | |
7810 | * number of input args and compatible return and argument types. | |
7811 | * These rules are not set in stone and probably will be adjusted as we get | |
7812 | * more experience with using BPF CO-RE relocations. | |
7813 | */ | |
29db4bea AS |
7814 | int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, |
7815 | const struct btf *targ_btf, __u32 targ_id) | |
7816 | { | |
fd75733d | 7817 | return __bpf_core_types_are_compat(local_btf, local_id, targ_btf, targ_id, |
e70e13e7 | 7818 | MAX_TYPES_ARE_COMPAT_DEPTH); |
29db4bea AS |
7819 | } |
7820 | ||
ec6209c8 DM |
7821 | #define MAX_TYPES_MATCH_DEPTH 2 |
7822 | ||
7823 | int bpf_core_types_match(const struct btf *local_btf, u32 local_id, | |
7824 | const struct btf *targ_btf, u32 targ_id) | |
7825 | { | |
7826 | return __bpf_core_types_match(local_btf, local_id, targ_btf, targ_id, false, | |
7827 | MAX_TYPES_MATCH_DEPTH); | |
7828 | } | |
7829 | ||
29db4bea AS |
7830 | static bool bpf_core_is_flavor_sep(const char *s) |
7831 | { | |
7832 | /* check X___Y name pattern, where X and Y are not underscores */ | |
7833 | return s[0] != '_' && /* X */ | |
7834 | s[1] == '_' && s[2] == '_' && s[3] == '_' && /* ___ */ | |
7835 | s[4] != '_'; /* Y */ | |
7836 | } | |
7837 | ||
7838 | size_t bpf_core_essential_name_len(const char *name) | |
7839 | { | |
7840 | size_t n = strlen(name); | |
7841 | int i; | |
7842 | ||
7843 | for (i = n - 5; i >= 0; i--) { | |
7844 | if (bpf_core_is_flavor_sep(name + i)) | |
7845 | return i + 1; | |
7846 | } | |
7847 | return n; | |
7848 | } | |
fbd94c7a | 7849 | |
1e89106d AS |
7850 | struct bpf_cand_cache { |
7851 | const char *name; | |
7852 | u32 name_len; | |
7853 | u16 kind; | |
7854 | u16 cnt; | |
7855 | struct { | |
7856 | const struct btf *btf; | |
7857 | u32 id; | |
7858 | } cands[]; | |
7859 | }; | |
7860 | ||
7861 | static void bpf_free_cands(struct bpf_cand_cache *cands) | |
7862 | { | |
7863 | if (!cands->cnt) | |
7864 | /* empty candidate array was allocated on stack */ | |
7865 | return; | |
7866 | kfree(cands); | |
7867 | } | |
7868 | ||
7869 | static void bpf_free_cands_from_cache(struct bpf_cand_cache *cands) | |
7870 | { | |
7871 | kfree(cands->name); | |
7872 | kfree(cands); | |
7873 | } | |
7874 | ||
7875 | #define VMLINUX_CAND_CACHE_SIZE 31 | |
7876 | static struct bpf_cand_cache *vmlinux_cand_cache[VMLINUX_CAND_CACHE_SIZE]; | |
7877 | ||
7878 | #define MODULE_CAND_CACHE_SIZE 31 | |
7879 | static struct bpf_cand_cache *module_cand_cache[MODULE_CAND_CACHE_SIZE]; | |
7880 | ||
7881 | static DEFINE_MUTEX(cand_cache_mutex); | |
7882 | ||
7883 | static void __print_cand_cache(struct bpf_verifier_log *log, | |
7884 | struct bpf_cand_cache **cache, | |
7885 | int cache_size) | |
7886 | { | |
7887 | struct bpf_cand_cache *cc; | |
7888 | int i, j; | |
7889 | ||
7890 | for (i = 0; i < cache_size; i++) { | |
7891 | cc = cache[i]; | |
7892 | if (!cc) | |
7893 | continue; | |
7894 | bpf_log(log, "[%d]%s(", i, cc->name); | |
7895 | for (j = 0; j < cc->cnt; j++) { | |
7896 | bpf_log(log, "%d", cc->cands[j].id); | |
7897 | if (j < cc->cnt - 1) | |
7898 | bpf_log(log, " "); | |
7899 | } | |
7900 | bpf_log(log, "), "); | |
7901 | } | |
7902 | } | |
7903 | ||
7904 | static void print_cand_cache(struct bpf_verifier_log *log) | |
7905 | { | |
7906 | mutex_lock(&cand_cache_mutex); | |
7907 | bpf_log(log, "vmlinux_cand_cache:"); | |
7908 | __print_cand_cache(log, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); | |
7909 | bpf_log(log, "\nmodule_cand_cache:"); | |
7910 | __print_cand_cache(log, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
7911 | bpf_log(log, "\n"); | |
7912 | mutex_unlock(&cand_cache_mutex); | |
7913 | } | |
7914 | ||
7915 | static u32 hash_cands(struct bpf_cand_cache *cands) | |
7916 | { | |
7917 | return jhash(cands->name, cands->name_len, 0); | |
7918 | } | |
7919 | ||
7920 | static struct bpf_cand_cache *check_cand_cache(struct bpf_cand_cache *cands, | |
7921 | struct bpf_cand_cache **cache, | |
7922 | int cache_size) | |
7923 | { | |
7924 | struct bpf_cand_cache *cc = cache[hash_cands(cands) % cache_size]; | |
7925 | ||
7926 | if (cc && cc->name_len == cands->name_len && | |
7927 | !strncmp(cc->name, cands->name, cands->name_len)) | |
7928 | return cc; | |
7929 | return NULL; | |
7930 | } | |
7931 | ||
7932 | static size_t sizeof_cands(int cnt) | |
7933 | { | |
7934 | return offsetof(struct bpf_cand_cache, cands[cnt]); | |
7935 | } | |
7936 | ||
7937 | static struct bpf_cand_cache *populate_cand_cache(struct bpf_cand_cache *cands, | |
7938 | struct bpf_cand_cache **cache, | |
7939 | int cache_size) | |
7940 | { | |
7941 | struct bpf_cand_cache **cc = &cache[hash_cands(cands) % cache_size], *new_cands; | |
7942 | ||
7943 | if (*cc) { | |
7944 | bpf_free_cands_from_cache(*cc); | |
7945 | *cc = NULL; | |
7946 | } | |
4674f210 | 7947 | new_cands = kmemdup(cands, sizeof_cands(cands->cnt), GFP_KERNEL); |
1e89106d AS |
7948 | if (!new_cands) { |
7949 | bpf_free_cands(cands); | |
7950 | return ERR_PTR(-ENOMEM); | |
7951 | } | |
1e89106d AS |
7952 | /* strdup the name, since it will stay in cache. |
7953 | * the cands->name points to strings in prog's BTF and the prog can be unloaded. | |
7954 | */ | |
7955 | new_cands->name = kmemdup_nul(cands->name, cands->name_len, GFP_KERNEL); | |
7956 | bpf_free_cands(cands); | |
7957 | if (!new_cands->name) { | |
7958 | kfree(new_cands); | |
7959 | return ERR_PTR(-ENOMEM); | |
7960 | } | |
7961 | *cc = new_cands; | |
7962 | return new_cands; | |
7963 | } | |
7964 | ||
29f2e5bd | 7965 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
1e89106d AS |
7966 | static void __purge_cand_cache(struct btf *btf, struct bpf_cand_cache **cache, |
7967 | int cache_size) | |
7968 | { | |
7969 | struct bpf_cand_cache *cc; | |
7970 | int i, j; | |
7971 | ||
7972 | for (i = 0; i < cache_size; i++) { | |
7973 | cc = cache[i]; | |
7974 | if (!cc) | |
7975 | continue; | |
7976 | if (!btf) { | |
7977 | /* when new module is loaded purge all of module_cand_cache, | |
7978 | * since new module might have candidates with the name | |
7979 | * that matches cached cands. | |
7980 | */ | |
7981 | bpf_free_cands_from_cache(cc); | |
7982 | cache[i] = NULL; | |
7983 | continue; | |
7984 | } | |
7985 | /* when module is unloaded purge cache entries | |
7986 | * that match module's btf | |
7987 | */ | |
7988 | for (j = 0; j < cc->cnt; j++) | |
7989 | if (cc->cands[j].btf == btf) { | |
7990 | bpf_free_cands_from_cache(cc); | |
7991 | cache[i] = NULL; | |
7992 | break; | |
7993 | } | |
7994 | } | |
7995 | ||
7996 | } | |
7997 | ||
7998 | static void purge_cand_cache(struct btf *btf) | |
7999 | { | |
8000 | mutex_lock(&cand_cache_mutex); | |
8001 | __purge_cand_cache(btf, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
8002 | mutex_unlock(&cand_cache_mutex); | |
8003 | } | |
29f2e5bd | 8004 | #endif |
1e89106d AS |
8005 | |
8006 | static struct bpf_cand_cache * | |
8007 | bpf_core_add_cands(struct bpf_cand_cache *cands, const struct btf *targ_btf, | |
8008 | int targ_start_id) | |
8009 | { | |
8010 | struct bpf_cand_cache *new_cands; | |
8011 | const struct btf_type *t; | |
8012 | const char *targ_name; | |
8013 | size_t targ_essent_len; | |
8014 | int n, i; | |
8015 | ||
8016 | n = btf_nr_types(targ_btf); | |
8017 | for (i = targ_start_id; i < n; i++) { | |
8018 | t = btf_type_by_id(targ_btf, i); | |
8019 | if (btf_kind(t) != cands->kind) | |
8020 | continue; | |
8021 | ||
8022 | targ_name = btf_name_by_offset(targ_btf, t->name_off); | |
8023 | if (!targ_name) | |
8024 | continue; | |
8025 | ||
8026 | /* the resched point is before strncmp to make sure that search | |
8027 | * for non-existing name will have a chance to schedule(). | |
8028 | */ | |
8029 | cond_resched(); | |
8030 | ||
8031 | if (strncmp(cands->name, targ_name, cands->name_len) != 0) | |
8032 | continue; | |
8033 | ||
8034 | targ_essent_len = bpf_core_essential_name_len(targ_name); | |
8035 | if (targ_essent_len != cands->name_len) | |
8036 | continue; | |
8037 | ||
8038 | /* most of the time there is only one candidate for a given kind+name pair */ | |
8039 | new_cands = kmalloc(sizeof_cands(cands->cnt + 1), GFP_KERNEL); | |
8040 | if (!new_cands) { | |
8041 | bpf_free_cands(cands); | |
8042 | return ERR_PTR(-ENOMEM); | |
8043 | } | |
8044 | ||
8045 | memcpy(new_cands, cands, sizeof_cands(cands->cnt)); | |
8046 | bpf_free_cands(cands); | |
8047 | cands = new_cands; | |
8048 | cands->cands[cands->cnt].btf = targ_btf; | |
8049 | cands->cands[cands->cnt].id = i; | |
8050 | cands->cnt++; | |
8051 | } | |
8052 | return cands; | |
8053 | } | |
8054 | ||
8055 | static struct bpf_cand_cache * | |
8056 | bpf_core_find_cands(struct bpf_core_ctx *ctx, u32 local_type_id) | |
8057 | { | |
8058 | struct bpf_cand_cache *cands, *cc, local_cand = {}; | |
8059 | const struct btf *local_btf = ctx->btf; | |
8060 | const struct btf_type *local_type; | |
8061 | const struct btf *main_btf; | |
8062 | size_t local_essent_len; | |
8063 | struct btf *mod_btf; | |
8064 | const char *name; | |
8065 | int id; | |
8066 | ||
8067 | main_btf = bpf_get_btf_vmlinux(); | |
8068 | if (IS_ERR(main_btf)) | |
f18a4997 | 8069 | return ERR_CAST(main_btf); |
7ada3787 KKD |
8070 | if (!main_btf) |
8071 | return ERR_PTR(-EINVAL); | |
1e89106d AS |
8072 | |
8073 | local_type = btf_type_by_id(local_btf, local_type_id); | |
8074 | if (!local_type) | |
8075 | return ERR_PTR(-EINVAL); | |
8076 | ||
8077 | name = btf_name_by_offset(local_btf, local_type->name_off); | |
8078 | if (str_is_empty(name)) | |
8079 | return ERR_PTR(-EINVAL); | |
8080 | local_essent_len = bpf_core_essential_name_len(name); | |
8081 | ||
8082 | cands = &local_cand; | |
8083 | cands->name = name; | |
8084 | cands->kind = btf_kind(local_type); | |
8085 | cands->name_len = local_essent_len; | |
8086 | ||
8087 | cc = check_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); | |
8088 | /* cands is a pointer to stack here */ | |
8089 | if (cc) { | |
8090 | if (cc->cnt) | |
8091 | return cc; | |
8092 | goto check_modules; | |
8093 | } | |
8094 | ||
8095 | /* Attempt to find target candidates in vmlinux BTF first */ | |
8096 | cands = bpf_core_add_cands(cands, main_btf, 1); | |
8097 | if (IS_ERR(cands)) | |
f18a4997 | 8098 | return ERR_CAST(cands); |
1e89106d AS |
8099 | |
8100 | /* cands is a pointer to kmalloced memory here if cands->cnt > 0 */ | |
8101 | ||
8102 | /* populate cache even when cands->cnt == 0 */ | |
8103 | cc = populate_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); | |
8104 | if (IS_ERR(cc)) | |
f18a4997 | 8105 | return ERR_CAST(cc); |
1e89106d AS |
8106 | |
8107 | /* if vmlinux BTF has any candidate, don't go for module BTFs */ | |
8108 | if (cc->cnt) | |
8109 | return cc; | |
8110 | ||
8111 | check_modules: | |
8112 | /* cands is a pointer to stack here and cands->cnt == 0 */ | |
8113 | cc = check_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
8114 | if (cc) | |
8115 | /* if cache has it return it even if cc->cnt == 0 */ | |
8116 | return cc; | |
8117 | ||
8118 | /* If candidate is not found in vmlinux's BTF then search in module's BTFs */ | |
8119 | spin_lock_bh(&btf_idr_lock); | |
8120 | idr_for_each_entry(&btf_idr, mod_btf, id) { | |
8121 | if (!btf_is_module(mod_btf)) | |
8122 | continue; | |
8123 | /* linear search could be slow hence unlock/lock | |
8124 | * the IDR to avoiding holding it for too long | |
8125 | */ | |
8126 | btf_get(mod_btf); | |
8127 | spin_unlock_bh(&btf_idr_lock); | |
8128 | cands = bpf_core_add_cands(cands, mod_btf, btf_nr_types(main_btf)); | |
8129 | if (IS_ERR(cands)) { | |
8130 | btf_put(mod_btf); | |
f18a4997 | 8131 | return ERR_CAST(cands); |
1e89106d AS |
8132 | } |
8133 | spin_lock_bh(&btf_idr_lock); | |
8134 | btf_put(mod_btf); | |
8135 | } | |
8136 | spin_unlock_bh(&btf_idr_lock); | |
8137 | /* cands is a pointer to kmalloced memory here if cands->cnt > 0 | |
8138 | * or pointer to stack if cands->cnd == 0. | |
8139 | * Copy it into the cache even when cands->cnt == 0 and | |
8140 | * return the result. | |
8141 | */ | |
8142 | return populate_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
8143 | } | |
8144 | ||
fbd94c7a AS |
8145 | int bpf_core_apply(struct bpf_core_ctx *ctx, const struct bpf_core_relo *relo, |
8146 | int relo_idx, void *insn) | |
8147 | { | |
1e89106d AS |
8148 | bool need_cands = relo->kind != BPF_CORE_TYPE_ID_LOCAL; |
8149 | struct bpf_core_cand_list cands = {}; | |
adb8fa19 | 8150 | struct bpf_core_relo_res targ_res; |
78c1f8d0 | 8151 | struct bpf_core_spec *specs; |
1e89106d AS |
8152 | int err; |
8153 | ||
78c1f8d0 AS |
8154 | /* ~4k of temp memory necessary to convert LLVM spec like "0:1:0:5" |
8155 | * into arrays of btf_ids of struct fields and array indices. | |
8156 | */ | |
8157 | specs = kcalloc(3, sizeof(*specs), GFP_KERNEL); | |
8158 | if (!specs) | |
8159 | return -ENOMEM; | |
8160 | ||
1e89106d AS |
8161 | if (need_cands) { |
8162 | struct bpf_cand_cache *cc; | |
8163 | int i; | |
8164 | ||
8165 | mutex_lock(&cand_cache_mutex); | |
8166 | cc = bpf_core_find_cands(ctx, relo->type_id); | |
8167 | if (IS_ERR(cc)) { | |
8168 | bpf_log(ctx->log, "target candidate search failed for %d\n", | |
8169 | relo->type_id); | |
8170 | err = PTR_ERR(cc); | |
8171 | goto out; | |
8172 | } | |
8173 | if (cc->cnt) { | |
8174 | cands.cands = kcalloc(cc->cnt, sizeof(*cands.cands), GFP_KERNEL); | |
8175 | if (!cands.cands) { | |
8176 | err = -ENOMEM; | |
8177 | goto out; | |
8178 | } | |
8179 | } | |
8180 | for (i = 0; i < cc->cnt; i++) { | |
8181 | bpf_log(ctx->log, | |
8182 | "CO-RE relocating %s %s: found target candidate [%d]\n", | |
8183 | btf_kind_str[cc->kind], cc->name, cc->cands[i].id); | |
8184 | cands.cands[i].btf = cc->cands[i].btf; | |
8185 | cands.cands[i].id = cc->cands[i].id; | |
8186 | } | |
8187 | cands.len = cc->cnt; | |
8188 | /* cand_cache_mutex needs to span the cache lookup and | |
8189 | * copy of btf pointer into bpf_core_cand_list, | |
adb8fa19 | 8190 | * since module can be unloaded while bpf_core_calc_relo_insn |
1e89106d AS |
8191 | * is working with module's btf. |
8192 | */ | |
8193 | } | |
8194 | ||
adb8fa19 MV |
8195 | err = bpf_core_calc_relo_insn((void *)ctx->log, relo, relo_idx, ctx->btf, &cands, specs, |
8196 | &targ_res); | |
8197 | if (err) | |
8198 | goto out; | |
8199 | ||
8200 | err = bpf_core_patch_insn((void *)ctx->log, insn, relo->insn_off / 8, relo, relo_idx, | |
8201 | &targ_res); | |
8202 | ||
1e89106d | 8203 | out: |
78c1f8d0 | 8204 | kfree(specs); |
1e89106d AS |
8205 | if (need_cands) { |
8206 | kfree(cands.cands); | |
8207 | mutex_unlock(&cand_cache_mutex); | |
8208 | if (ctx->log->level & BPF_LOG_LEVEL2) | |
8209 | print_cand_cache(ctx->log); | |
8210 | } | |
8211 | return err; | |
fbd94c7a | 8212 | } |