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69b693f0 MKL |
1 | /* SPDX-License-Identifier: GPL-2.0 */ |
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> |
91cc1a99 AS |
22 | #include <linux/skmsg.h> |
23 | #include <linux/perf_event.h> | |
24 | #include <net/sock.h> | |
69b693f0 MKL |
25 | |
26 | /* BTF (BPF Type Format) is the meta data format which describes | |
27 | * the data types of BPF program/map. Hence, it basically focus | |
28 | * on the C programming language which the modern BPF is primary | |
29 | * using. | |
30 | * | |
31 | * ELF Section: | |
32 | * ~~~~~~~~~~~ | |
33 | * The BTF data is stored under the ".BTF" ELF section | |
34 | * | |
35 | * struct btf_type: | |
36 | * ~~~~~~~~~~~~~~~ | |
37 | * Each 'struct btf_type' object describes a C data type. | |
38 | * Depending on the type it is describing, a 'struct btf_type' | |
39 | * object may be followed by more data. F.e. | |
40 | * To describe an array, 'struct btf_type' is followed by | |
41 | * 'struct btf_array'. | |
42 | * | |
43 | * 'struct btf_type' and any extra data following it are | |
44 | * 4 bytes aligned. | |
45 | * | |
46 | * Type section: | |
47 | * ~~~~~~~~~~~~~ | |
48 | * The BTF type section contains a list of 'struct btf_type' objects. | |
49 | * Each one describes a C type. Recall from the above section | |
50 | * that a 'struct btf_type' object could be immediately followed by extra | |
51 | * data in order to desribe some particular C types. | |
52 | * | |
53 | * type_id: | |
54 | * ~~~~~~~ | |
55 | * Each btf_type object is identified by a type_id. The type_id | |
56 | * is implicitly implied by the location of the btf_type object in | |
57 | * the BTF type section. The first one has type_id 1. The second | |
58 | * one has type_id 2...etc. Hence, an earlier btf_type has | |
59 | * a smaller type_id. | |
60 | * | |
61 | * A btf_type object may refer to another btf_type object by using | |
62 | * type_id (i.e. the "type" in the "struct btf_type"). | |
63 | * | |
64 | * NOTE that we cannot assume any reference-order. | |
65 | * A btf_type object can refer to an earlier btf_type object | |
66 | * but it can also refer to a later btf_type object. | |
67 | * | |
68 | * For example, to describe "const void *". A btf_type | |
69 | * object describing "const" may refer to another btf_type | |
70 | * object describing "void *". This type-reference is done | |
71 | * by specifying type_id: | |
72 | * | |
73 | * [1] CONST (anon) type_id=2 | |
74 | * [2] PTR (anon) type_id=0 | |
75 | * | |
76 | * The above is the btf_verifier debug log: | |
77 | * - Each line started with "[?]" is a btf_type object | |
78 | * - [?] is the type_id of the btf_type object. | |
79 | * - CONST/PTR is the BTF_KIND_XXX | |
80 | * - "(anon)" is the name of the type. It just | |
81 | * happens that CONST and PTR has no name. | |
82 | * - type_id=XXX is the 'u32 type' in btf_type | |
83 | * | |
84 | * NOTE: "void" has type_id 0 | |
85 | * | |
86 | * String section: | |
87 | * ~~~~~~~~~~~~~~ | |
88 | * The BTF string section contains the names used by the type section. | |
89 | * Each string is referred by an "offset" from the beginning of the | |
90 | * string section. | |
91 | * | |
92 | * Each string is '\0' terminated. | |
93 | * | |
94 | * The first character in the string section must be '\0' | |
95 | * which is used to mean 'anonymous'. Some btf_type may not | |
96 | * have a name. | |
97 | */ | |
98 | ||
99 | /* BTF verification: | |
100 | * | |
101 | * To verify BTF data, two passes are needed. | |
102 | * | |
103 | * Pass #1 | |
104 | * ~~~~~~~ | |
105 | * The first pass is to collect all btf_type objects to | |
106 | * an array: "btf->types". | |
107 | * | |
108 | * Depending on the C type that a btf_type is describing, | |
109 | * a btf_type may be followed by extra data. We don't know | |
110 | * how many btf_type is there, and more importantly we don't | |
111 | * know where each btf_type is located in the type section. | |
112 | * | |
113 | * Without knowing the location of each type_id, most verifications | |
114 | * cannot be done. e.g. an earlier btf_type may refer to a later | |
115 | * btf_type (recall the "const void *" above), so we cannot | |
116 | * check this type-reference in the first pass. | |
117 | * | |
118 | * In the first pass, it still does some verifications (e.g. | |
119 | * checking the name is a valid offset to the string section). | |
eb3f595d MKL |
120 | * |
121 | * Pass #2 | |
122 | * ~~~~~~~ | |
123 | * The main focus is to resolve a btf_type that is referring | |
124 | * to another type. | |
125 | * | |
126 | * We have to ensure the referring type: | |
127 | * 1) does exist in the BTF (i.e. in btf->types[]) | |
128 | * 2) does not cause a loop: | |
129 | * struct A { | |
130 | * struct B b; | |
131 | * }; | |
132 | * | |
133 | * struct B { | |
134 | * struct A a; | |
135 | * }; | |
136 | * | |
137 | * btf_type_needs_resolve() decides if a btf_type needs | |
138 | * to be resolved. | |
139 | * | |
140 | * The needs_resolve type implements the "resolve()" ops which | |
141 | * essentially does a DFS and detects backedge. | |
142 | * | |
143 | * During resolve (or DFS), different C types have different | |
144 | * "RESOLVED" conditions. | |
145 | * | |
146 | * When resolving a BTF_KIND_STRUCT, we need to resolve all its | |
147 | * members because a member is always referring to another | |
148 | * type. A struct's member can be treated as "RESOLVED" if | |
149 | * it is referring to a BTF_KIND_PTR. Otherwise, the | |
150 | * following valid C struct would be rejected: | |
151 | * | |
152 | * struct A { | |
153 | * int m; | |
154 | * struct A *a; | |
155 | * }; | |
156 | * | |
157 | * When resolving a BTF_KIND_PTR, it needs to keep resolving if | |
158 | * it is referring to another BTF_KIND_PTR. Otherwise, we cannot | |
159 | * detect a pointer loop, e.g.: | |
160 | * BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR + | |
161 | * ^ | | |
162 | * +-----------------------------------------+ | |
163 | * | |
69b693f0 MKL |
164 | */ |
165 | ||
b1e8818c | 166 | #define BITS_PER_U128 (sizeof(u64) * BITS_PER_BYTE * 2) |
69b693f0 MKL |
167 | #define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1) |
168 | #define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK) | |
169 | #define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3) | |
170 | #define BITS_ROUNDUP_BYTES(bits) \ | |
171 | (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits)) | |
172 | ||
9d5f9f70 | 173 | #define BTF_INFO_MASK 0x8f00ffff |
aea2f7b8 MKL |
174 | #define BTF_INT_MASK 0x0fffffff |
175 | #define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE) | |
176 | #define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET) | |
177 | ||
69b693f0 MKL |
178 | /* 16MB for 64k structs and each has 16 members and |
179 | * a few MB spaces for the string section. | |
180 | * The hard limit is S32_MAX. | |
181 | */ | |
182 | #define BTF_MAX_SIZE (16 * 1024 * 1024) | |
69b693f0 | 183 | |
eb3f595d MKL |
184 | #define for_each_member_from(i, from, struct_type, member) \ |
185 | for (i = from, member = btf_type_member(struct_type) + from; \ | |
186 | i < btf_type_vlen(struct_type); \ | |
187 | i++, member++) | |
188 | ||
1dc92851 DB |
189 | #define for_each_vsi(i, struct_type, member) \ |
190 | for (i = 0, member = btf_type_var_secinfo(struct_type); \ | |
191 | i < btf_type_vlen(struct_type); \ | |
192 | i++, member++) | |
193 | ||
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 | |
69b693f0 | 202 | struct btf { |
f80442a4 | 203 | void *data; |
69b693f0 | 204 | struct btf_type **types; |
eb3f595d MKL |
205 | u32 *resolved_ids; |
206 | u32 *resolved_sizes; | |
69b693f0 MKL |
207 | const char *strings; |
208 | void *nohdr_data; | |
f80442a4 | 209 | struct btf_header hdr; |
69b693f0 MKL |
210 | u32 nr_types; |
211 | u32 types_size; | |
212 | u32 data_size; | |
f56a653c | 213 | refcount_t refcnt; |
78958fca MKL |
214 | u32 id; |
215 | struct rcu_head rcu; | |
69b693f0 MKL |
216 | }; |
217 | ||
eb3f595d MKL |
218 | enum verifier_phase { |
219 | CHECK_META, | |
220 | CHECK_TYPE, | |
221 | }; | |
222 | ||
223 | struct resolve_vertex { | |
224 | const struct btf_type *t; | |
225 | u32 type_id; | |
226 | u16 next_member; | |
227 | }; | |
228 | ||
229 | enum visit_state { | |
230 | NOT_VISITED, | |
231 | VISITED, | |
232 | RESOLVED, | |
233 | }; | |
234 | ||
235 | enum resolve_mode { | |
236 | RESOLVE_TBD, /* To Be Determined */ | |
237 | RESOLVE_PTR, /* Resolving for Pointer */ | |
238 | RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union | |
239 | * or array | |
240 | */ | |
241 | }; | |
242 | ||
243 | #define MAX_RESOLVE_DEPTH 32 | |
244 | ||
f80442a4 MKL |
245 | struct btf_sec_info { |
246 | u32 off; | |
247 | u32 len; | |
248 | }; | |
249 | ||
69b693f0 MKL |
250 | struct btf_verifier_env { |
251 | struct btf *btf; | |
eb3f595d MKL |
252 | u8 *visit_states; |
253 | struct resolve_vertex stack[MAX_RESOLVE_DEPTH]; | |
69b693f0 MKL |
254 | struct bpf_verifier_log log; |
255 | u32 log_type_id; | |
eb3f595d MKL |
256 | u32 top_stack; |
257 | enum verifier_phase phase; | |
258 | enum resolve_mode resolve_mode; | |
69b693f0 MKL |
259 | }; |
260 | ||
261 | static const char * const btf_kind_str[NR_BTF_KINDS] = { | |
262 | [BTF_KIND_UNKN] = "UNKNOWN", | |
263 | [BTF_KIND_INT] = "INT", | |
264 | [BTF_KIND_PTR] = "PTR", | |
265 | [BTF_KIND_ARRAY] = "ARRAY", | |
266 | [BTF_KIND_STRUCT] = "STRUCT", | |
267 | [BTF_KIND_UNION] = "UNION", | |
268 | [BTF_KIND_ENUM] = "ENUM", | |
269 | [BTF_KIND_FWD] = "FWD", | |
270 | [BTF_KIND_TYPEDEF] = "TYPEDEF", | |
271 | [BTF_KIND_VOLATILE] = "VOLATILE", | |
272 | [BTF_KIND_CONST] = "CONST", | |
273 | [BTF_KIND_RESTRICT] = "RESTRICT", | |
2667a262 MKL |
274 | [BTF_KIND_FUNC] = "FUNC", |
275 | [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO", | |
1dc92851 DB |
276 | [BTF_KIND_VAR] = "VAR", |
277 | [BTF_KIND_DATASEC] = "DATASEC", | |
69b693f0 MKL |
278 | }; |
279 | ||
be8704ff AS |
280 | static const char *btf_type_str(const struct btf_type *t) |
281 | { | |
282 | return btf_kind_str[BTF_INFO_KIND(t->info)]; | |
283 | } | |
284 | ||
69b693f0 MKL |
285 | struct btf_kind_operations { |
286 | s32 (*check_meta)(struct btf_verifier_env *env, | |
287 | const struct btf_type *t, | |
288 | u32 meta_left); | |
eb3f595d MKL |
289 | int (*resolve)(struct btf_verifier_env *env, |
290 | const struct resolve_vertex *v); | |
179cde8c MKL |
291 | int (*check_member)(struct btf_verifier_env *env, |
292 | const struct btf_type *struct_type, | |
293 | const struct btf_member *member, | |
294 | const struct btf_type *member_type); | |
9d5f9f70 YS |
295 | int (*check_kflag_member)(struct btf_verifier_env *env, |
296 | const struct btf_type *struct_type, | |
297 | const struct btf_member *member, | |
298 | const struct btf_type *member_type); | |
69b693f0 MKL |
299 | void (*log_details)(struct btf_verifier_env *env, |
300 | const struct btf_type *t); | |
b00b8dae MKL |
301 | void (*seq_show)(const struct btf *btf, const struct btf_type *t, |
302 | u32 type_id, void *data, u8 bits_offsets, | |
303 | struct seq_file *m); | |
69b693f0 MKL |
304 | }; |
305 | ||
306 | static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS]; | |
307 | static struct btf_type btf_void; | |
308 | ||
2667a262 MKL |
309 | static int btf_resolve(struct btf_verifier_env *env, |
310 | const struct btf_type *t, u32 type_id); | |
311 | ||
eb3f595d MKL |
312 | static bool btf_type_is_modifier(const struct btf_type *t) |
313 | { | |
314 | /* Some of them is not strictly a C modifier | |
315 | * but they are grouped into the same bucket | |
316 | * for BTF concern: | |
317 | * A type (t) that refers to another | |
318 | * type through t->type AND its size cannot | |
319 | * be determined without following the t->type. | |
320 | * | |
321 | * ptr does not fall into this bucket | |
322 | * because its size is always sizeof(void *). | |
323 | */ | |
324 | switch (BTF_INFO_KIND(t->info)) { | |
325 | case BTF_KIND_TYPEDEF: | |
326 | case BTF_KIND_VOLATILE: | |
327 | case BTF_KIND_CONST: | |
328 | case BTF_KIND_RESTRICT: | |
329 | return true; | |
330 | } | |
331 | ||
332 | return false; | |
333 | } | |
334 | ||
2824ecb7 | 335 | bool btf_type_is_void(const struct btf_type *t) |
eb3f595d | 336 | { |
b47a0bd2 MKL |
337 | return t == &btf_void; |
338 | } | |
339 | ||
340 | static bool btf_type_is_fwd(const struct btf_type *t) | |
341 | { | |
342 | return BTF_INFO_KIND(t->info) == BTF_KIND_FWD; | |
343 | } | |
344 | ||
345 | static bool btf_type_nosize(const struct btf_type *t) | |
346 | { | |
2667a262 MKL |
347 | return btf_type_is_void(t) || btf_type_is_fwd(t) || |
348 | btf_type_is_func(t) || btf_type_is_func_proto(t); | |
eb3f595d MKL |
349 | } |
350 | ||
b47a0bd2 | 351 | static bool btf_type_nosize_or_null(const struct btf_type *t) |
eb3f595d | 352 | { |
b47a0bd2 | 353 | return !t || btf_type_nosize(t); |
eb3f595d MKL |
354 | } |
355 | ||
356 | /* union is only a special case of struct: | |
357 | * all its offsetof(member) == 0 | |
358 | */ | |
359 | static bool btf_type_is_struct(const struct btf_type *t) | |
360 | { | |
361 | u8 kind = BTF_INFO_KIND(t->info); | |
362 | ||
363 | return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION; | |
364 | } | |
365 | ||
d83525ca AS |
366 | static bool __btf_type_is_struct(const struct btf_type *t) |
367 | { | |
368 | return BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT; | |
369 | } | |
370 | ||
eb3f595d MKL |
371 | static bool btf_type_is_array(const struct btf_type *t) |
372 | { | |
373 | return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY; | |
374 | } | |
375 | ||
1dc92851 DB |
376 | static bool btf_type_is_var(const struct btf_type *t) |
377 | { | |
378 | return BTF_INFO_KIND(t->info) == BTF_KIND_VAR; | |
379 | } | |
380 | ||
381 | static bool btf_type_is_datasec(const struct btf_type *t) | |
382 | { | |
383 | return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC; | |
384 | } | |
385 | ||
27ae7997 MKL |
386 | s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind) |
387 | { | |
388 | const struct btf_type *t; | |
389 | const char *tname; | |
390 | u32 i; | |
391 | ||
392 | for (i = 1; i <= btf->nr_types; i++) { | |
393 | t = btf->types[i]; | |
394 | if (BTF_INFO_KIND(t->info) != kind) | |
395 | continue; | |
396 | ||
397 | tname = btf_name_by_offset(btf, t->name_off); | |
398 | if (!strcmp(tname, name)) | |
399 | return i; | |
400 | } | |
401 | ||
402 | return -ENOENT; | |
403 | } | |
404 | ||
405 | const struct btf_type *btf_type_skip_modifiers(const struct btf *btf, | |
406 | u32 id, u32 *res_id) | |
407 | { | |
408 | const struct btf_type *t = btf_type_by_id(btf, id); | |
409 | ||
410 | while (btf_type_is_modifier(t)) { | |
411 | id = t->type; | |
412 | t = btf_type_by_id(btf, t->type); | |
413 | } | |
414 | ||
415 | if (res_id) | |
416 | *res_id = id; | |
417 | ||
418 | return t; | |
419 | } | |
420 | ||
421 | const struct btf_type *btf_type_resolve_ptr(const struct btf *btf, | |
422 | u32 id, u32 *res_id) | |
423 | { | |
424 | const struct btf_type *t; | |
425 | ||
426 | t = btf_type_skip_modifiers(btf, id, NULL); | |
427 | if (!btf_type_is_ptr(t)) | |
428 | return NULL; | |
429 | ||
430 | return btf_type_skip_modifiers(btf, t->type, res_id); | |
431 | } | |
432 | ||
433 | const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf, | |
434 | u32 id, u32 *res_id) | |
435 | { | |
436 | const struct btf_type *ptype; | |
437 | ||
438 | ptype = btf_type_resolve_ptr(btf, id, res_id); | |
439 | if (ptype && btf_type_is_func_proto(ptype)) | |
440 | return ptype; | |
441 | ||
442 | return NULL; | |
443 | } | |
444 | ||
1dc92851 DB |
445 | /* Types that act only as a source, not sink or intermediate |
446 | * type when resolving. | |
447 | */ | |
448 | static bool btf_type_is_resolve_source_only(const struct btf_type *t) | |
449 | { | |
450 | return btf_type_is_var(t) || | |
451 | btf_type_is_datasec(t); | |
452 | } | |
453 | ||
eb3f595d MKL |
454 | /* What types need to be resolved? |
455 | * | |
456 | * btf_type_is_modifier() is an obvious one. | |
457 | * | |
458 | * btf_type_is_struct() because its member refers to | |
459 | * another type (through member->type). | |
1dc92851 DB |
460 | * |
461 | * btf_type_is_var() because the variable refers to | |
462 | * another type. btf_type_is_datasec() holds multiple | |
463 | * btf_type_is_var() types that need resolving. | |
464 | * | |
eb3f595d MKL |
465 | * btf_type_is_array() because its element (array->type) |
466 | * refers to another type. Array can be thought of a | |
467 | * special case of struct while array just has the same | |
468 | * member-type repeated by array->nelems of times. | |
469 | */ | |
470 | static bool btf_type_needs_resolve(const struct btf_type *t) | |
471 | { | |
472 | return btf_type_is_modifier(t) || | |
1dc92851 DB |
473 | btf_type_is_ptr(t) || |
474 | btf_type_is_struct(t) || | |
475 | btf_type_is_array(t) || | |
476 | btf_type_is_var(t) || | |
477 | btf_type_is_datasec(t); | |
eb3f595d MKL |
478 | } |
479 | ||
480 | /* t->size can be used */ | |
481 | static bool btf_type_has_size(const struct btf_type *t) | |
482 | { | |
483 | switch (BTF_INFO_KIND(t->info)) { | |
484 | case BTF_KIND_INT: | |
485 | case BTF_KIND_STRUCT: | |
486 | case BTF_KIND_UNION: | |
487 | case BTF_KIND_ENUM: | |
1dc92851 | 488 | case BTF_KIND_DATASEC: |
eb3f595d MKL |
489 | return true; |
490 | } | |
491 | ||
492 | return false; | |
493 | } | |
494 | ||
69b693f0 MKL |
495 | static const char *btf_int_encoding_str(u8 encoding) |
496 | { | |
497 | if (encoding == 0) | |
498 | return "(none)"; | |
499 | else if (encoding == BTF_INT_SIGNED) | |
500 | return "SIGNED"; | |
501 | else if (encoding == BTF_INT_CHAR) | |
502 | return "CHAR"; | |
503 | else if (encoding == BTF_INT_BOOL) | |
504 | return "BOOL"; | |
69b693f0 MKL |
505 | else |
506 | return "UNKN"; | |
507 | } | |
508 | ||
69b693f0 MKL |
509 | static u32 btf_type_int(const struct btf_type *t) |
510 | { | |
511 | return *(u32 *)(t + 1); | |
512 | } | |
513 | ||
514 | static const struct btf_array *btf_type_array(const struct btf_type *t) | |
515 | { | |
516 | return (const struct btf_array *)(t + 1); | |
517 | } | |
518 | ||
69b693f0 MKL |
519 | static const struct btf_enum *btf_type_enum(const struct btf_type *t) |
520 | { | |
521 | return (const struct btf_enum *)(t + 1); | |
522 | } | |
523 | ||
1dc92851 DB |
524 | static const struct btf_var *btf_type_var(const struct btf_type *t) |
525 | { | |
526 | return (const struct btf_var *)(t + 1); | |
527 | } | |
528 | ||
529 | static const struct btf_var_secinfo *btf_type_var_secinfo(const struct btf_type *t) | |
530 | { | |
531 | return (const struct btf_var_secinfo *)(t + 1); | |
532 | } | |
533 | ||
69b693f0 MKL |
534 | static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t) |
535 | { | |
536 | return kind_ops[BTF_INFO_KIND(t->info)]; | |
537 | } | |
538 | ||
583c5318 | 539 | static bool btf_name_offset_valid(const struct btf *btf, u32 offset) |
69b693f0 | 540 | { |
aea2f7b8 MKL |
541 | return BTF_STR_OFFSET_VALID(offset) && |
542 | offset < btf->hdr.str_len; | |
69b693f0 MKL |
543 | } |
544 | ||
1dc92851 DB |
545 | static bool __btf_name_char_ok(char c, bool first, bool dot_ok) |
546 | { | |
547 | if ((first ? !isalpha(c) : | |
548 | !isalnum(c)) && | |
549 | c != '_' && | |
550 | ((c == '.' && !dot_ok) || | |
551 | c != '.')) | |
552 | return false; | |
553 | return true; | |
554 | } | |
555 | ||
556 | static bool __btf_name_valid(const struct btf *btf, u32 offset, bool dot_ok) | |
2667a262 MKL |
557 | { |
558 | /* offset must be valid */ | |
559 | const char *src = &btf->strings[offset]; | |
560 | const char *src_limit; | |
561 | ||
1dc92851 | 562 | if (!__btf_name_char_ok(*src, true, dot_ok)) |
2667a262 MKL |
563 | return false; |
564 | ||
565 | /* set a limit on identifier length */ | |
566 | src_limit = src + KSYM_NAME_LEN; | |
567 | src++; | |
568 | while (*src && src < src_limit) { | |
1dc92851 | 569 | if (!__btf_name_char_ok(*src, false, dot_ok)) |
2667a262 MKL |
570 | return false; |
571 | src++; | |
572 | } | |
573 | ||
574 | return !*src; | |
575 | } | |
576 | ||
1dc92851 DB |
577 | /* Only C-style identifier is permitted. This can be relaxed if |
578 | * necessary. | |
579 | */ | |
580 | static bool btf_name_valid_identifier(const struct btf *btf, u32 offset) | |
581 | { | |
582 | return __btf_name_valid(btf, offset, false); | |
583 | } | |
584 | ||
585 | static bool btf_name_valid_section(const struct btf *btf, u32 offset) | |
586 | { | |
587 | return __btf_name_valid(btf, offset, true); | |
588 | } | |
589 | ||
23127b33 | 590 | static const char *__btf_name_by_offset(const struct btf *btf, u32 offset) |
69b693f0 | 591 | { |
aea2f7b8 | 592 | if (!offset) |
69b693f0 | 593 | return "(anon)"; |
aea2f7b8 MKL |
594 | else if (offset < btf->hdr.str_len) |
595 | return &btf->strings[offset]; | |
69b693f0 MKL |
596 | else |
597 | return "(invalid-name-offset)"; | |
598 | } | |
599 | ||
23127b33 MKL |
600 | const char *btf_name_by_offset(const struct btf *btf, u32 offset) |
601 | { | |
602 | if (offset < btf->hdr.str_len) | |
603 | return &btf->strings[offset]; | |
604 | ||
605 | return NULL; | |
606 | } | |
607 | ||
838e9690 | 608 | const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id) |
eb3f595d MKL |
609 | { |
610 | if (type_id > btf->nr_types) | |
611 | return NULL; | |
612 | ||
613 | return btf->types[type_id]; | |
614 | } | |
615 | ||
4ef5f574 MKL |
616 | /* |
617 | * Regular int is not a bit field and it must be either | |
b1e8818c | 618 | * u8/u16/u32/u64 or __int128. |
4ef5f574 MKL |
619 | */ |
620 | static bool btf_type_int_is_regular(const struct btf_type *t) | |
621 | { | |
36fc3c8c | 622 | u8 nr_bits, nr_bytes; |
4ef5f574 MKL |
623 | u32 int_data; |
624 | ||
625 | int_data = btf_type_int(t); | |
626 | nr_bits = BTF_INT_BITS(int_data); | |
627 | nr_bytes = BITS_ROUNDUP_BYTES(nr_bits); | |
628 | if (BITS_PER_BYTE_MASKED(nr_bits) || | |
629 | BTF_INT_OFFSET(int_data) || | |
630 | (nr_bytes != sizeof(u8) && nr_bytes != sizeof(u16) && | |
b1e8818c YS |
631 | nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64) && |
632 | nr_bytes != (2 * sizeof(u64)))) { | |
4ef5f574 MKL |
633 | return false; |
634 | } | |
635 | ||
636 | return true; | |
637 | } | |
638 | ||
9a1126b6 | 639 | /* |
ffa0c1cf YS |
640 | * Check that given struct member is a regular int with expected |
641 | * offset and size. | |
9a1126b6 | 642 | */ |
ffa0c1cf YS |
643 | bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s, |
644 | const struct btf_member *m, | |
645 | u32 expected_offset, u32 expected_size) | |
9a1126b6 | 646 | { |
ffa0c1cf YS |
647 | const struct btf_type *t; |
648 | u32 id, int_data; | |
649 | u8 nr_bits; | |
9a1126b6 | 650 | |
ffa0c1cf YS |
651 | id = m->type; |
652 | t = btf_type_id_size(btf, &id, NULL); | |
653 | if (!t || !btf_type_is_int(t)) | |
9a1126b6 RG |
654 | return false; |
655 | ||
656 | int_data = btf_type_int(t); | |
657 | nr_bits = BTF_INT_BITS(int_data); | |
ffa0c1cf YS |
658 | if (btf_type_kflag(s)) { |
659 | u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset); | |
660 | u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset); | |
661 | ||
662 | /* if kflag set, int should be a regular int and | |
663 | * bit offset should be at byte boundary. | |
664 | */ | |
665 | return !bitfield_size && | |
666 | BITS_ROUNDUP_BYTES(bit_offset) == expected_offset && | |
667 | BITS_ROUNDUP_BYTES(nr_bits) == expected_size; | |
668 | } | |
669 | ||
670 | if (BTF_INT_OFFSET(int_data) || | |
671 | BITS_PER_BYTE_MASKED(m->offset) || | |
672 | BITS_ROUNDUP_BYTES(m->offset) != expected_offset || | |
673 | BITS_PER_BYTE_MASKED(nr_bits) || | |
674 | BITS_ROUNDUP_BYTES(nr_bits) != expected_size) | |
9a1126b6 RG |
675 | return false; |
676 | ||
677 | return true; | |
678 | } | |
679 | ||
69b693f0 MKL |
680 | __printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log, |
681 | const char *fmt, ...) | |
682 | { | |
683 | va_list args; | |
684 | ||
685 | va_start(args, fmt); | |
686 | bpf_verifier_vlog(log, fmt, args); | |
687 | va_end(args); | |
688 | } | |
689 | ||
690 | __printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env, | |
691 | const char *fmt, ...) | |
692 | { | |
693 | struct bpf_verifier_log *log = &env->log; | |
694 | va_list args; | |
695 | ||
696 | if (!bpf_verifier_log_needed(log)) | |
697 | return; | |
698 | ||
699 | va_start(args, fmt); | |
700 | bpf_verifier_vlog(log, fmt, args); | |
701 | va_end(args); | |
702 | } | |
703 | ||
704 | __printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env, | |
705 | const struct btf_type *t, | |
706 | bool log_details, | |
707 | const char *fmt, ...) | |
708 | { | |
709 | struct bpf_verifier_log *log = &env->log; | |
710 | u8 kind = BTF_INFO_KIND(t->info); | |
711 | struct btf *btf = env->btf; | |
712 | va_list args; | |
713 | ||
714 | if (!bpf_verifier_log_needed(log)) | |
715 | return; | |
716 | ||
8580ac94 AS |
717 | /* btf verifier prints all types it is processing via |
718 | * btf_verifier_log_type(..., fmt = NULL). | |
719 | * Skip those prints for in-kernel BTF verification. | |
720 | */ | |
721 | if (log->level == BPF_LOG_KERNEL && !fmt) | |
722 | return; | |
723 | ||
69b693f0 MKL |
724 | __btf_verifier_log(log, "[%u] %s %s%s", |
725 | env->log_type_id, | |
726 | btf_kind_str[kind], | |
23127b33 | 727 | __btf_name_by_offset(btf, t->name_off), |
69b693f0 MKL |
728 | log_details ? " " : ""); |
729 | ||
730 | if (log_details) | |
731 | btf_type_ops(t)->log_details(env, t); | |
732 | ||
733 | if (fmt && *fmt) { | |
734 | __btf_verifier_log(log, " "); | |
735 | va_start(args, fmt); | |
736 | bpf_verifier_vlog(log, fmt, args); | |
737 | va_end(args); | |
738 | } | |
739 | ||
740 | __btf_verifier_log(log, "\n"); | |
741 | } | |
742 | ||
743 | #define btf_verifier_log_type(env, t, ...) \ | |
744 | __btf_verifier_log_type((env), (t), true, __VA_ARGS__) | |
745 | #define btf_verifier_log_basic(env, t, ...) \ | |
746 | __btf_verifier_log_type((env), (t), false, __VA_ARGS__) | |
747 | ||
748 | __printf(4, 5) | |
749 | static void btf_verifier_log_member(struct btf_verifier_env *env, | |
750 | const struct btf_type *struct_type, | |
751 | const struct btf_member *member, | |
752 | const char *fmt, ...) | |
753 | { | |
754 | struct bpf_verifier_log *log = &env->log; | |
755 | struct btf *btf = env->btf; | |
756 | va_list args; | |
757 | ||
758 | if (!bpf_verifier_log_needed(log)) | |
759 | return; | |
760 | ||
8580ac94 AS |
761 | if (log->level == BPF_LOG_KERNEL && !fmt) |
762 | return; | |
eb3f595d MKL |
763 | /* The CHECK_META phase already did a btf dump. |
764 | * | |
765 | * If member is logged again, it must hit an error in | |
766 | * parsing this member. It is useful to print out which | |
767 | * struct this member belongs to. | |
768 | */ | |
769 | if (env->phase != CHECK_META) | |
770 | btf_verifier_log_type(env, struct_type, NULL); | |
771 | ||
9d5f9f70 YS |
772 | if (btf_type_kflag(struct_type)) |
773 | __btf_verifier_log(log, | |
774 | "\t%s type_id=%u bitfield_size=%u bits_offset=%u", | |
775 | __btf_name_by_offset(btf, member->name_off), | |
776 | member->type, | |
777 | BTF_MEMBER_BITFIELD_SIZE(member->offset), | |
778 | BTF_MEMBER_BIT_OFFSET(member->offset)); | |
779 | else | |
780 | __btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u", | |
781 | __btf_name_by_offset(btf, member->name_off), | |
782 | member->type, member->offset); | |
69b693f0 MKL |
783 | |
784 | if (fmt && *fmt) { | |
785 | __btf_verifier_log(log, " "); | |
786 | va_start(args, fmt); | |
787 | bpf_verifier_vlog(log, fmt, args); | |
788 | va_end(args); | |
789 | } | |
790 | ||
791 | __btf_verifier_log(log, "\n"); | |
792 | } | |
793 | ||
1dc92851 DB |
794 | __printf(4, 5) |
795 | static void btf_verifier_log_vsi(struct btf_verifier_env *env, | |
796 | const struct btf_type *datasec_type, | |
797 | const struct btf_var_secinfo *vsi, | |
798 | const char *fmt, ...) | |
799 | { | |
800 | struct bpf_verifier_log *log = &env->log; | |
801 | va_list args; | |
802 | ||
803 | if (!bpf_verifier_log_needed(log)) | |
804 | return; | |
8580ac94 AS |
805 | if (log->level == BPF_LOG_KERNEL && !fmt) |
806 | return; | |
1dc92851 DB |
807 | if (env->phase != CHECK_META) |
808 | btf_verifier_log_type(env, datasec_type, NULL); | |
809 | ||
810 | __btf_verifier_log(log, "\t type_id=%u offset=%u size=%u", | |
811 | vsi->type, vsi->offset, vsi->size); | |
812 | if (fmt && *fmt) { | |
813 | __btf_verifier_log(log, " "); | |
814 | va_start(args, fmt); | |
815 | bpf_verifier_vlog(log, fmt, args); | |
816 | va_end(args); | |
817 | } | |
818 | ||
819 | __btf_verifier_log(log, "\n"); | |
820 | } | |
821 | ||
f80442a4 MKL |
822 | static void btf_verifier_log_hdr(struct btf_verifier_env *env, |
823 | u32 btf_data_size) | |
69b693f0 MKL |
824 | { |
825 | struct bpf_verifier_log *log = &env->log; | |
826 | const struct btf *btf = env->btf; | |
827 | const struct btf_header *hdr; | |
828 | ||
829 | if (!bpf_verifier_log_needed(log)) | |
830 | return; | |
831 | ||
8580ac94 AS |
832 | if (log->level == BPF_LOG_KERNEL) |
833 | return; | |
f80442a4 | 834 | hdr = &btf->hdr; |
69b693f0 MKL |
835 | __btf_verifier_log(log, "magic: 0x%x\n", hdr->magic); |
836 | __btf_verifier_log(log, "version: %u\n", hdr->version); | |
837 | __btf_verifier_log(log, "flags: 0x%x\n", hdr->flags); | |
f80442a4 | 838 | __btf_verifier_log(log, "hdr_len: %u\n", hdr->hdr_len); |
69b693f0 | 839 | __btf_verifier_log(log, "type_off: %u\n", hdr->type_off); |
f80442a4 | 840 | __btf_verifier_log(log, "type_len: %u\n", hdr->type_len); |
69b693f0 MKL |
841 | __btf_verifier_log(log, "str_off: %u\n", hdr->str_off); |
842 | __btf_verifier_log(log, "str_len: %u\n", hdr->str_len); | |
f80442a4 | 843 | __btf_verifier_log(log, "btf_total_size: %u\n", btf_data_size); |
69b693f0 MKL |
844 | } |
845 | ||
846 | static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t) | |
847 | { | |
848 | struct btf *btf = env->btf; | |
849 | ||
850 | /* < 2 because +1 for btf_void which is always in btf->types[0]. | |
851 | * btf_void is not accounted in btf->nr_types because btf_void | |
852 | * does not come from the BTF file. | |
853 | */ | |
854 | if (btf->types_size - btf->nr_types < 2) { | |
855 | /* Expand 'types' array */ | |
856 | ||
857 | struct btf_type **new_types; | |
858 | u32 expand_by, new_size; | |
859 | ||
aea2f7b8 | 860 | if (btf->types_size == BTF_MAX_TYPE) { |
69b693f0 MKL |
861 | btf_verifier_log(env, "Exceeded max num of types"); |
862 | return -E2BIG; | |
863 | } | |
864 | ||
865 | expand_by = max_t(u32, btf->types_size >> 2, 16); | |
aea2f7b8 | 866 | new_size = min_t(u32, BTF_MAX_TYPE, |
69b693f0 MKL |
867 | btf->types_size + expand_by); |
868 | ||
778e1cdd | 869 | new_types = kvcalloc(new_size, sizeof(*new_types), |
69b693f0 MKL |
870 | GFP_KERNEL | __GFP_NOWARN); |
871 | if (!new_types) | |
872 | return -ENOMEM; | |
873 | ||
874 | if (btf->nr_types == 0) | |
875 | new_types[0] = &btf_void; | |
876 | else | |
877 | memcpy(new_types, btf->types, | |
878 | sizeof(*btf->types) * (btf->nr_types + 1)); | |
879 | ||
880 | kvfree(btf->types); | |
881 | btf->types = new_types; | |
882 | btf->types_size = new_size; | |
883 | } | |
884 | ||
885 | btf->types[++(btf->nr_types)] = t; | |
886 | ||
887 | return 0; | |
888 | } | |
889 | ||
78958fca MKL |
890 | static int btf_alloc_id(struct btf *btf) |
891 | { | |
892 | int id; | |
893 | ||
894 | idr_preload(GFP_KERNEL); | |
895 | spin_lock_bh(&btf_idr_lock); | |
896 | id = idr_alloc_cyclic(&btf_idr, btf, 1, INT_MAX, GFP_ATOMIC); | |
897 | if (id > 0) | |
898 | btf->id = id; | |
899 | spin_unlock_bh(&btf_idr_lock); | |
900 | idr_preload_end(); | |
901 | ||
902 | if (WARN_ON_ONCE(!id)) | |
903 | return -ENOSPC; | |
904 | ||
905 | return id > 0 ? 0 : id; | |
906 | } | |
907 | ||
908 | static void btf_free_id(struct btf *btf) | |
909 | { | |
910 | unsigned long flags; | |
911 | ||
912 | /* | |
913 | * In map-in-map, calling map_delete_elem() on outer | |
914 | * map will call bpf_map_put on the inner map. | |
915 | * It will then eventually call btf_free_id() | |
916 | * on the inner map. Some of the map_delete_elem() | |
917 | * implementation may have irq disabled, so | |
918 | * we need to use the _irqsave() version instead | |
919 | * of the _bh() version. | |
920 | */ | |
921 | spin_lock_irqsave(&btf_idr_lock, flags); | |
922 | idr_remove(&btf_idr, btf->id); | |
923 | spin_unlock_irqrestore(&btf_idr_lock, flags); | |
924 | } | |
925 | ||
69b693f0 MKL |
926 | static void btf_free(struct btf *btf) |
927 | { | |
928 | kvfree(btf->types); | |
eb3f595d MKL |
929 | kvfree(btf->resolved_sizes); |
930 | kvfree(btf->resolved_ids); | |
69b693f0 MKL |
931 | kvfree(btf->data); |
932 | kfree(btf); | |
933 | } | |
934 | ||
78958fca | 935 | static void btf_free_rcu(struct rcu_head *rcu) |
f56a653c | 936 | { |
78958fca MKL |
937 | struct btf *btf = container_of(rcu, struct btf, rcu); |
938 | ||
939 | btf_free(btf); | |
f56a653c MKL |
940 | } |
941 | ||
942 | void btf_put(struct btf *btf) | |
943 | { | |
78958fca MKL |
944 | if (btf && refcount_dec_and_test(&btf->refcnt)) { |
945 | btf_free_id(btf); | |
946 | call_rcu(&btf->rcu, btf_free_rcu); | |
947 | } | |
f56a653c MKL |
948 | } |
949 | ||
eb3f595d MKL |
950 | static int env_resolve_init(struct btf_verifier_env *env) |
951 | { | |
952 | struct btf *btf = env->btf; | |
953 | u32 nr_types = btf->nr_types; | |
954 | u32 *resolved_sizes = NULL; | |
955 | u32 *resolved_ids = NULL; | |
956 | u8 *visit_states = NULL; | |
957 | ||
958 | /* +1 for btf_void */ | |
778e1cdd | 959 | resolved_sizes = kvcalloc(nr_types + 1, sizeof(*resolved_sizes), |
eb3f595d MKL |
960 | GFP_KERNEL | __GFP_NOWARN); |
961 | if (!resolved_sizes) | |
962 | goto nomem; | |
963 | ||
778e1cdd | 964 | resolved_ids = kvcalloc(nr_types + 1, sizeof(*resolved_ids), |
eb3f595d MKL |
965 | GFP_KERNEL | __GFP_NOWARN); |
966 | if (!resolved_ids) | |
967 | goto nomem; | |
968 | ||
778e1cdd | 969 | visit_states = kvcalloc(nr_types + 1, sizeof(*visit_states), |
eb3f595d MKL |
970 | GFP_KERNEL | __GFP_NOWARN); |
971 | if (!visit_states) | |
972 | goto nomem; | |
973 | ||
974 | btf->resolved_sizes = resolved_sizes; | |
975 | btf->resolved_ids = resolved_ids; | |
976 | env->visit_states = visit_states; | |
977 | ||
978 | return 0; | |
979 | ||
980 | nomem: | |
981 | kvfree(resolved_sizes); | |
982 | kvfree(resolved_ids); | |
983 | kvfree(visit_states); | |
984 | return -ENOMEM; | |
985 | } | |
986 | ||
69b693f0 MKL |
987 | static void btf_verifier_env_free(struct btf_verifier_env *env) |
988 | { | |
eb3f595d | 989 | kvfree(env->visit_states); |
69b693f0 MKL |
990 | kfree(env); |
991 | } | |
992 | ||
eb3f595d MKL |
993 | static bool env_type_is_resolve_sink(const struct btf_verifier_env *env, |
994 | const struct btf_type *next_type) | |
995 | { | |
996 | switch (env->resolve_mode) { | |
997 | case RESOLVE_TBD: | |
998 | /* int, enum or void is a sink */ | |
999 | return !btf_type_needs_resolve(next_type); | |
1000 | case RESOLVE_PTR: | |
2667a262 MKL |
1001 | /* int, enum, void, struct, array, func or func_proto is a sink |
1002 | * for ptr | |
1003 | */ | |
eb3f595d MKL |
1004 | return !btf_type_is_modifier(next_type) && |
1005 | !btf_type_is_ptr(next_type); | |
1006 | case RESOLVE_STRUCT_OR_ARRAY: | |
2667a262 MKL |
1007 | /* int, enum, void, ptr, func or func_proto is a sink |
1008 | * for struct and array | |
1009 | */ | |
eb3f595d MKL |
1010 | return !btf_type_is_modifier(next_type) && |
1011 | !btf_type_is_array(next_type) && | |
1012 | !btf_type_is_struct(next_type); | |
1013 | default: | |
53c8036c | 1014 | BUG(); |
eb3f595d MKL |
1015 | } |
1016 | } | |
1017 | ||
1018 | static bool env_type_is_resolved(const struct btf_verifier_env *env, | |
1019 | u32 type_id) | |
1020 | { | |
1021 | return env->visit_states[type_id] == RESOLVED; | |
1022 | } | |
1023 | ||
1024 | static int env_stack_push(struct btf_verifier_env *env, | |
1025 | const struct btf_type *t, u32 type_id) | |
1026 | { | |
1027 | struct resolve_vertex *v; | |
1028 | ||
1029 | if (env->top_stack == MAX_RESOLVE_DEPTH) | |
1030 | return -E2BIG; | |
1031 | ||
1032 | if (env->visit_states[type_id] != NOT_VISITED) | |
1033 | return -EEXIST; | |
1034 | ||
1035 | env->visit_states[type_id] = VISITED; | |
1036 | ||
1037 | v = &env->stack[env->top_stack++]; | |
1038 | v->t = t; | |
1039 | v->type_id = type_id; | |
1040 | v->next_member = 0; | |
1041 | ||
1042 | if (env->resolve_mode == RESOLVE_TBD) { | |
1043 | if (btf_type_is_ptr(t)) | |
1044 | env->resolve_mode = RESOLVE_PTR; | |
1045 | else if (btf_type_is_struct(t) || btf_type_is_array(t)) | |
1046 | env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY; | |
1047 | } | |
1048 | ||
1049 | return 0; | |
1050 | } | |
1051 | ||
1052 | static void env_stack_set_next_member(struct btf_verifier_env *env, | |
1053 | u16 next_member) | |
1054 | { | |
1055 | env->stack[env->top_stack - 1].next_member = next_member; | |
1056 | } | |
1057 | ||
1058 | static void env_stack_pop_resolved(struct btf_verifier_env *env, | |
1059 | u32 resolved_type_id, | |
1060 | u32 resolved_size) | |
1061 | { | |
1062 | u32 type_id = env->stack[--(env->top_stack)].type_id; | |
1063 | struct btf *btf = env->btf; | |
1064 | ||
1065 | btf->resolved_sizes[type_id] = resolved_size; | |
1066 | btf->resolved_ids[type_id] = resolved_type_id; | |
1067 | env->visit_states[type_id] = RESOLVED; | |
1068 | } | |
1069 | ||
1070 | static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env) | |
1071 | { | |
1072 | return env->top_stack ? &env->stack[env->top_stack - 1] : NULL; | |
1073 | } | |
1074 | ||
7e3617a7 MKL |
1075 | /* Resolve the size of a passed-in "type" |
1076 | * | |
1077 | * type: is an array (e.g. u32 array[x][y]) | |
1078 | * return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY, | |
1079 | * *type_size: (x * y * sizeof(u32)). Hence, *type_size always | |
1080 | * corresponds to the return type. | |
1081 | * *elem_type: u32 | |
1082 | * *total_nelems: (x * y). Hence, individual elem size is | |
1083 | * (*type_size / *total_nelems) | |
1084 | * | |
1085 | * type: is not an array (e.g. const struct X) | |
1086 | * return type: type "struct X" | |
1087 | * *type_size: sizeof(struct X) | |
1088 | * *elem_type: same as return type ("struct X") | |
1089 | * *total_nelems: 1 | |
1090 | */ | |
85d33df3 | 1091 | const struct btf_type * |
7e3617a7 MKL |
1092 | btf_resolve_size(const struct btf *btf, const struct btf_type *type, |
1093 | u32 *type_size, const struct btf_type **elem_type, | |
1094 | u32 *total_nelems) | |
1095 | { | |
1096 | const struct btf_type *array_type = NULL; | |
1097 | const struct btf_array *array; | |
1098 | u32 i, size, nelems = 1; | |
1099 | ||
1100 | for (i = 0; i < MAX_RESOLVE_DEPTH; i++) { | |
1101 | switch (BTF_INFO_KIND(type->info)) { | |
1102 | /* type->size can be used */ | |
1103 | case BTF_KIND_INT: | |
1104 | case BTF_KIND_STRUCT: | |
1105 | case BTF_KIND_UNION: | |
1106 | case BTF_KIND_ENUM: | |
1107 | size = type->size; | |
1108 | goto resolved; | |
1109 | ||
1110 | case BTF_KIND_PTR: | |
1111 | size = sizeof(void *); | |
1112 | goto resolved; | |
1113 | ||
1114 | /* Modifiers */ | |
1115 | case BTF_KIND_TYPEDEF: | |
1116 | case BTF_KIND_VOLATILE: | |
1117 | case BTF_KIND_CONST: | |
1118 | case BTF_KIND_RESTRICT: | |
1119 | type = btf_type_by_id(btf, type->type); | |
1120 | break; | |
1121 | ||
1122 | case BTF_KIND_ARRAY: | |
1123 | if (!array_type) | |
1124 | array_type = type; | |
1125 | array = btf_type_array(type); | |
1126 | if (nelems && array->nelems > U32_MAX / nelems) | |
1127 | return ERR_PTR(-EINVAL); | |
1128 | nelems *= array->nelems; | |
1129 | type = btf_type_by_id(btf, array->type); | |
1130 | break; | |
1131 | ||
1132 | /* type without size */ | |
1133 | default: | |
1134 | return ERR_PTR(-EINVAL); | |
1135 | } | |
1136 | } | |
1137 | ||
1138 | return ERR_PTR(-EINVAL); | |
1139 | ||
1140 | resolved: | |
1141 | if (nelems && size > U32_MAX / nelems) | |
1142 | return ERR_PTR(-EINVAL); | |
1143 | ||
1144 | *type_size = nelems * size; | |
85d33df3 MKL |
1145 | if (total_nelems) |
1146 | *total_nelems = nelems; | |
1147 | if (elem_type) | |
1148 | *elem_type = type; | |
7e3617a7 MKL |
1149 | |
1150 | return array_type ? : type; | |
1151 | } | |
1152 | ||
eb3f595d MKL |
1153 | /* The input param "type_id" must point to a needs_resolve type */ |
1154 | static const struct btf_type *btf_type_id_resolve(const struct btf *btf, | |
1155 | u32 *type_id) | |
1156 | { | |
1157 | *type_id = btf->resolved_ids[*type_id]; | |
1158 | return btf_type_by_id(btf, *type_id); | |
1159 | } | |
1160 | ||
1161 | const struct btf_type *btf_type_id_size(const struct btf *btf, | |
1162 | u32 *type_id, u32 *ret_size) | |
1163 | { | |
1164 | const struct btf_type *size_type; | |
1165 | u32 size_type_id = *type_id; | |
1166 | u32 size = 0; | |
1167 | ||
1168 | size_type = btf_type_by_id(btf, size_type_id); | |
b47a0bd2 | 1169 | if (btf_type_nosize_or_null(size_type)) |
eb3f595d MKL |
1170 | return NULL; |
1171 | ||
1172 | if (btf_type_has_size(size_type)) { | |
1173 | size = size_type->size; | |
1174 | } else if (btf_type_is_array(size_type)) { | |
1175 | size = btf->resolved_sizes[size_type_id]; | |
1176 | } else if (btf_type_is_ptr(size_type)) { | |
1177 | size = sizeof(void *); | |
1178 | } else { | |
1dc92851 DB |
1179 | if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) && |
1180 | !btf_type_is_var(size_type))) | |
eb3f595d MKL |
1181 | return NULL; |
1182 | ||
eb3f595d MKL |
1183 | size_type_id = btf->resolved_ids[size_type_id]; |
1184 | size_type = btf_type_by_id(btf, size_type_id); | |
b47a0bd2 | 1185 | if (btf_type_nosize_or_null(size_type)) |
eb3f595d | 1186 | return NULL; |
1acc5d5c AN |
1187 | else if (btf_type_has_size(size_type)) |
1188 | size = size_type->size; | |
1189 | else if (btf_type_is_array(size_type)) | |
1190 | size = btf->resolved_sizes[size_type_id]; | |
1191 | else if (btf_type_is_ptr(size_type)) | |
1192 | size = sizeof(void *); | |
1193 | else | |
1194 | return NULL; | |
eb3f595d MKL |
1195 | } |
1196 | ||
1197 | *type_id = size_type_id; | |
1198 | if (ret_size) | |
1199 | *ret_size = size; | |
1200 | ||
1201 | return size_type; | |
1202 | } | |
1203 | ||
179cde8c MKL |
1204 | static int btf_df_check_member(struct btf_verifier_env *env, |
1205 | const struct btf_type *struct_type, | |
1206 | const struct btf_member *member, | |
1207 | const struct btf_type *member_type) | |
1208 | { | |
1209 | btf_verifier_log_basic(env, struct_type, | |
1210 | "Unsupported check_member"); | |
1211 | return -EINVAL; | |
1212 | } | |
1213 | ||
9d5f9f70 YS |
1214 | static int btf_df_check_kflag_member(struct btf_verifier_env *env, |
1215 | const struct btf_type *struct_type, | |
1216 | const struct btf_member *member, | |
1217 | const struct btf_type *member_type) | |
1218 | { | |
1219 | btf_verifier_log_basic(env, struct_type, | |
1220 | "Unsupported check_kflag_member"); | |
1221 | return -EINVAL; | |
1222 | } | |
1223 | ||
1224 | /* Used for ptr, array and struct/union type members. | |
1225 | * int, enum and modifier types have their specific callback functions. | |
1226 | */ | |
1227 | static int btf_generic_check_kflag_member(struct btf_verifier_env *env, | |
1228 | const struct btf_type *struct_type, | |
1229 | const struct btf_member *member, | |
1230 | const struct btf_type *member_type) | |
1231 | { | |
1232 | if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) { | |
1233 | btf_verifier_log_member(env, struct_type, member, | |
1234 | "Invalid member bitfield_size"); | |
1235 | return -EINVAL; | |
1236 | } | |
1237 | ||
1238 | /* bitfield size is 0, so member->offset represents bit offset only. | |
1239 | * It is safe to call non kflag check_member variants. | |
1240 | */ | |
1241 | return btf_type_ops(member_type)->check_member(env, struct_type, | |
1242 | member, | |
1243 | member_type); | |
1244 | } | |
1245 | ||
eb3f595d MKL |
1246 | static int btf_df_resolve(struct btf_verifier_env *env, |
1247 | const struct resolve_vertex *v) | |
1248 | { | |
1249 | btf_verifier_log_basic(env, v->t, "Unsupported resolve"); | |
1250 | return -EINVAL; | |
1251 | } | |
1252 | ||
b00b8dae MKL |
1253 | static void btf_df_seq_show(const struct btf *btf, const struct btf_type *t, |
1254 | u32 type_id, void *data, u8 bits_offsets, | |
1255 | struct seq_file *m) | |
1256 | { | |
1257 | seq_printf(m, "<unsupported kind:%u>", BTF_INFO_KIND(t->info)); | |
1258 | } | |
1259 | ||
179cde8c MKL |
1260 | static int btf_int_check_member(struct btf_verifier_env *env, |
1261 | const struct btf_type *struct_type, | |
1262 | const struct btf_member *member, | |
1263 | const struct btf_type *member_type) | |
1264 | { | |
1265 | u32 int_data = btf_type_int(member_type); | |
1266 | u32 struct_bits_off = member->offset; | |
1267 | u32 struct_size = struct_type->size; | |
1268 | u32 nr_copy_bits; | |
1269 | u32 bytes_offset; | |
1270 | ||
1271 | if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) { | |
1272 | btf_verifier_log_member(env, struct_type, member, | |
1273 | "bits_offset exceeds U32_MAX"); | |
1274 | return -EINVAL; | |
1275 | } | |
1276 | ||
1277 | struct_bits_off += BTF_INT_OFFSET(int_data); | |
1278 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
1279 | nr_copy_bits = BTF_INT_BITS(int_data) + | |
1280 | BITS_PER_BYTE_MASKED(struct_bits_off); | |
1281 | ||
b1e8818c | 1282 | if (nr_copy_bits > BITS_PER_U128) { |
179cde8c | 1283 | btf_verifier_log_member(env, struct_type, member, |
b1e8818c | 1284 | "nr_copy_bits exceeds 128"); |
179cde8c MKL |
1285 | return -EINVAL; |
1286 | } | |
1287 | ||
1288 | if (struct_size < bytes_offset || | |
1289 | struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { | |
1290 | btf_verifier_log_member(env, struct_type, member, | |
1291 | "Member exceeds struct_size"); | |
1292 | return -EINVAL; | |
1293 | } | |
1294 | ||
1295 | return 0; | |
1296 | } | |
1297 | ||
9d5f9f70 YS |
1298 | static int btf_int_check_kflag_member(struct btf_verifier_env *env, |
1299 | const struct btf_type *struct_type, | |
1300 | const struct btf_member *member, | |
1301 | const struct btf_type *member_type) | |
1302 | { | |
1303 | u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset; | |
1304 | u32 int_data = btf_type_int(member_type); | |
1305 | u32 struct_size = struct_type->size; | |
1306 | u32 nr_copy_bits; | |
1307 | ||
1308 | /* a regular int type is required for the kflag int member */ | |
1309 | if (!btf_type_int_is_regular(member_type)) { | |
1310 | btf_verifier_log_member(env, struct_type, member, | |
1311 | "Invalid member base type"); | |
1312 | return -EINVAL; | |
1313 | } | |
1314 | ||
1315 | /* check sanity of bitfield size */ | |
1316 | nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); | |
1317 | struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); | |
1318 | nr_int_data_bits = BTF_INT_BITS(int_data); | |
1319 | if (!nr_bits) { | |
1320 | /* Not a bitfield member, member offset must be at byte | |
1321 | * boundary. | |
1322 | */ | |
1323 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
1324 | btf_verifier_log_member(env, struct_type, member, | |
1325 | "Invalid member offset"); | |
1326 | return -EINVAL; | |
1327 | } | |
1328 | ||
1329 | nr_bits = nr_int_data_bits; | |
1330 | } else if (nr_bits > nr_int_data_bits) { | |
1331 | btf_verifier_log_member(env, struct_type, member, | |
1332 | "Invalid member bitfield_size"); | |
1333 | return -EINVAL; | |
1334 | } | |
1335 | ||
1336 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
1337 | nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off); | |
b1e8818c | 1338 | if (nr_copy_bits > BITS_PER_U128) { |
9d5f9f70 | 1339 | btf_verifier_log_member(env, struct_type, member, |
b1e8818c | 1340 | "nr_copy_bits exceeds 128"); |
9d5f9f70 YS |
1341 | return -EINVAL; |
1342 | } | |
1343 | ||
1344 | if (struct_size < bytes_offset || | |
1345 | struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { | |
1346 | btf_verifier_log_member(env, struct_type, member, | |
1347 | "Member exceeds struct_size"); | |
1348 | return -EINVAL; | |
1349 | } | |
1350 | ||
1351 | return 0; | |
1352 | } | |
1353 | ||
69b693f0 MKL |
1354 | static s32 btf_int_check_meta(struct btf_verifier_env *env, |
1355 | const struct btf_type *t, | |
1356 | u32 meta_left) | |
1357 | { | |
1358 | u32 int_data, nr_bits, meta_needed = sizeof(int_data); | |
1359 | u16 encoding; | |
1360 | ||
1361 | if (meta_left < meta_needed) { | |
1362 | btf_verifier_log_basic(env, t, | |
1363 | "meta_left:%u meta_needed:%u", | |
1364 | meta_left, meta_needed); | |
1365 | return -EINVAL; | |
1366 | } | |
1367 | ||
1368 | if (btf_type_vlen(t)) { | |
1369 | btf_verifier_log_type(env, t, "vlen != 0"); | |
1370 | return -EINVAL; | |
1371 | } | |
1372 | ||
9d5f9f70 YS |
1373 | if (btf_type_kflag(t)) { |
1374 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
1375 | return -EINVAL; | |
1376 | } | |
1377 | ||
69b693f0 | 1378 | int_data = btf_type_int(t); |
aea2f7b8 MKL |
1379 | if (int_data & ~BTF_INT_MASK) { |
1380 | btf_verifier_log_basic(env, t, "Invalid int_data:%x", | |
1381 | int_data); | |
1382 | return -EINVAL; | |
1383 | } | |
1384 | ||
69b693f0 MKL |
1385 | nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data); |
1386 | ||
b1e8818c | 1387 | if (nr_bits > BITS_PER_U128) { |
69b693f0 | 1388 | btf_verifier_log_type(env, t, "nr_bits exceeds %zu", |
b1e8818c | 1389 | BITS_PER_U128); |
69b693f0 MKL |
1390 | return -EINVAL; |
1391 | } | |
1392 | ||
1393 | if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) { | |
1394 | btf_verifier_log_type(env, t, "nr_bits exceeds type_size"); | |
1395 | return -EINVAL; | |
1396 | } | |
1397 | ||
aea2f7b8 MKL |
1398 | /* |
1399 | * Only one of the encoding bits is allowed and it | |
1400 | * should be sufficient for the pretty print purpose (i.e. decoding). | |
1401 | * Multiple bits can be allowed later if it is found | |
1402 | * to be insufficient. | |
1403 | */ | |
69b693f0 MKL |
1404 | encoding = BTF_INT_ENCODING(int_data); |
1405 | if (encoding && | |
1406 | encoding != BTF_INT_SIGNED && | |
1407 | encoding != BTF_INT_CHAR && | |
aea2f7b8 | 1408 | encoding != BTF_INT_BOOL) { |
69b693f0 MKL |
1409 | btf_verifier_log_type(env, t, "Unsupported encoding"); |
1410 | return -ENOTSUPP; | |
1411 | } | |
1412 | ||
1413 | btf_verifier_log_type(env, t, NULL); | |
1414 | ||
1415 | return meta_needed; | |
1416 | } | |
1417 | ||
1418 | static void btf_int_log(struct btf_verifier_env *env, | |
1419 | const struct btf_type *t) | |
1420 | { | |
1421 | int int_data = btf_type_int(t); | |
1422 | ||
1423 | btf_verifier_log(env, | |
1424 | "size=%u bits_offset=%u nr_bits=%u encoding=%s", | |
1425 | t->size, BTF_INT_OFFSET(int_data), | |
1426 | BTF_INT_BITS(int_data), | |
1427 | btf_int_encoding_str(BTF_INT_ENCODING(int_data))); | |
1428 | } | |
1429 | ||
b1e8818c YS |
1430 | static void btf_int128_print(struct seq_file *m, void *data) |
1431 | { | |
1432 | /* data points to a __int128 number. | |
1433 | * Suppose | |
1434 | * int128_num = *(__int128 *)data; | |
1435 | * The below formulas shows what upper_num and lower_num represents: | |
1436 | * upper_num = int128_num >> 64; | |
1437 | * lower_num = int128_num & 0xffffffffFFFFFFFFULL; | |
1438 | */ | |
1439 | u64 upper_num, lower_num; | |
1440 | ||
1441 | #ifdef __BIG_ENDIAN_BITFIELD | |
1442 | upper_num = *(u64 *)data; | |
1443 | lower_num = *(u64 *)(data + 8); | |
1444 | #else | |
1445 | upper_num = *(u64 *)(data + 8); | |
1446 | lower_num = *(u64 *)data; | |
1447 | #endif | |
1448 | if (upper_num == 0) | |
1449 | seq_printf(m, "0x%llx", lower_num); | |
1450 | else | |
1451 | seq_printf(m, "0x%llx%016llx", upper_num, lower_num); | |
1452 | } | |
1453 | ||
1454 | static void btf_int128_shift(u64 *print_num, u16 left_shift_bits, | |
1455 | u16 right_shift_bits) | |
1456 | { | |
1457 | u64 upper_num, lower_num; | |
1458 | ||
1459 | #ifdef __BIG_ENDIAN_BITFIELD | |
1460 | upper_num = print_num[0]; | |
1461 | lower_num = print_num[1]; | |
1462 | #else | |
1463 | upper_num = print_num[1]; | |
1464 | lower_num = print_num[0]; | |
1465 | #endif | |
1466 | ||
1467 | /* shake out un-needed bits by shift/or operations */ | |
1468 | if (left_shift_bits >= 64) { | |
1469 | upper_num = lower_num << (left_shift_bits - 64); | |
1470 | lower_num = 0; | |
1471 | } else { | |
1472 | upper_num = (upper_num << left_shift_bits) | | |
1473 | (lower_num >> (64 - left_shift_bits)); | |
1474 | lower_num = lower_num << left_shift_bits; | |
1475 | } | |
1476 | ||
1477 | if (right_shift_bits >= 64) { | |
1478 | lower_num = upper_num >> (right_shift_bits - 64); | |
1479 | upper_num = 0; | |
1480 | } else { | |
1481 | lower_num = (lower_num >> right_shift_bits) | | |
1482 | (upper_num << (64 - right_shift_bits)); | |
1483 | upper_num = upper_num >> right_shift_bits; | |
1484 | } | |
1485 | ||
1486 | #ifdef __BIG_ENDIAN_BITFIELD | |
1487 | print_num[0] = upper_num; | |
1488 | print_num[1] = lower_num; | |
1489 | #else | |
1490 | print_num[0] = lower_num; | |
1491 | print_num[1] = upper_num; | |
1492 | #endif | |
1493 | } | |
1494 | ||
f97be3ab YS |
1495 | static void btf_bitfield_seq_show(void *data, u8 bits_offset, |
1496 | u8 nr_bits, struct seq_file *m) | |
b00b8dae | 1497 | { |
b65f370d | 1498 | u16 left_shift_bits, right_shift_bits; |
36fc3c8c MKL |
1499 | u8 nr_copy_bytes; |
1500 | u8 nr_copy_bits; | |
b1e8818c | 1501 | u64 print_num[2] = {}; |
b00b8dae | 1502 | |
b00b8dae MKL |
1503 | nr_copy_bits = nr_bits + bits_offset; |
1504 | nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits); | |
1505 | ||
b1e8818c | 1506 | memcpy(print_num, data, nr_copy_bytes); |
b00b8dae | 1507 | |
b65f370d OK |
1508 | #ifdef __BIG_ENDIAN_BITFIELD |
1509 | left_shift_bits = bits_offset; | |
1510 | #else | |
b1e8818c | 1511 | left_shift_bits = BITS_PER_U128 - nr_copy_bits; |
b65f370d | 1512 | #endif |
b1e8818c | 1513 | right_shift_bits = BITS_PER_U128 - nr_bits; |
b00b8dae | 1514 | |
b1e8818c YS |
1515 | btf_int128_shift(print_num, left_shift_bits, right_shift_bits); |
1516 | btf_int128_print(m, print_num); | |
b00b8dae MKL |
1517 | } |
1518 | ||
9d5f9f70 | 1519 | |
f97be3ab YS |
1520 | static void btf_int_bits_seq_show(const struct btf *btf, |
1521 | const struct btf_type *t, | |
1522 | void *data, u8 bits_offset, | |
1523 | struct seq_file *m) | |
1524 | { | |
1525 | u32 int_data = btf_type_int(t); | |
1526 | u8 nr_bits = BTF_INT_BITS(int_data); | |
1527 | u8 total_bits_offset; | |
1528 | ||
1529 | /* | |
1530 | * bits_offset is at most 7. | |
b1e8818c | 1531 | * BTF_INT_OFFSET() cannot exceed 128 bits. |
f97be3ab YS |
1532 | */ |
1533 | total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data); | |
17e3ac81 YS |
1534 | data += BITS_ROUNDDOWN_BYTES(total_bits_offset); |
1535 | bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset); | |
1536 | btf_bitfield_seq_show(data, bits_offset, nr_bits, m); | |
f97be3ab YS |
1537 | } |
1538 | ||
b00b8dae MKL |
1539 | static void btf_int_seq_show(const struct btf *btf, const struct btf_type *t, |
1540 | u32 type_id, void *data, u8 bits_offset, | |
1541 | struct seq_file *m) | |
1542 | { | |
1543 | u32 int_data = btf_type_int(t); | |
1544 | u8 encoding = BTF_INT_ENCODING(int_data); | |
1545 | bool sign = encoding & BTF_INT_SIGNED; | |
36fc3c8c | 1546 | u8 nr_bits = BTF_INT_BITS(int_data); |
b00b8dae MKL |
1547 | |
1548 | if (bits_offset || BTF_INT_OFFSET(int_data) || | |
1549 | BITS_PER_BYTE_MASKED(nr_bits)) { | |
1550 | btf_int_bits_seq_show(btf, t, data, bits_offset, m); | |
1551 | return; | |
1552 | } | |
1553 | ||
1554 | switch (nr_bits) { | |
b1e8818c YS |
1555 | case 128: |
1556 | btf_int128_print(m, data); | |
1557 | break; | |
b00b8dae MKL |
1558 | case 64: |
1559 | if (sign) | |
1560 | seq_printf(m, "%lld", *(s64 *)data); | |
1561 | else | |
1562 | seq_printf(m, "%llu", *(u64 *)data); | |
1563 | break; | |
1564 | case 32: | |
1565 | if (sign) | |
1566 | seq_printf(m, "%d", *(s32 *)data); | |
1567 | else | |
1568 | seq_printf(m, "%u", *(u32 *)data); | |
1569 | break; | |
1570 | case 16: | |
1571 | if (sign) | |
1572 | seq_printf(m, "%d", *(s16 *)data); | |
1573 | else | |
1574 | seq_printf(m, "%u", *(u16 *)data); | |
1575 | break; | |
1576 | case 8: | |
1577 | if (sign) | |
1578 | seq_printf(m, "%d", *(s8 *)data); | |
1579 | else | |
1580 | seq_printf(m, "%u", *(u8 *)data); | |
1581 | break; | |
1582 | default: | |
1583 | btf_int_bits_seq_show(btf, t, data, bits_offset, m); | |
1584 | } | |
1585 | } | |
1586 | ||
69b693f0 MKL |
1587 | static const struct btf_kind_operations int_ops = { |
1588 | .check_meta = btf_int_check_meta, | |
eb3f595d | 1589 | .resolve = btf_df_resolve, |
179cde8c | 1590 | .check_member = btf_int_check_member, |
9d5f9f70 | 1591 | .check_kflag_member = btf_int_check_kflag_member, |
69b693f0 | 1592 | .log_details = btf_int_log, |
b00b8dae | 1593 | .seq_show = btf_int_seq_show, |
69b693f0 MKL |
1594 | }; |
1595 | ||
179cde8c MKL |
1596 | static int btf_modifier_check_member(struct btf_verifier_env *env, |
1597 | const struct btf_type *struct_type, | |
1598 | const struct btf_member *member, | |
1599 | const struct btf_type *member_type) | |
1600 | { | |
1601 | const struct btf_type *resolved_type; | |
1602 | u32 resolved_type_id = member->type; | |
1603 | struct btf_member resolved_member; | |
1604 | struct btf *btf = env->btf; | |
1605 | ||
1606 | resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); | |
1607 | if (!resolved_type) { | |
1608 | btf_verifier_log_member(env, struct_type, member, | |
1609 | "Invalid member"); | |
1610 | return -EINVAL; | |
1611 | } | |
1612 | ||
1613 | resolved_member = *member; | |
1614 | resolved_member.type = resolved_type_id; | |
1615 | ||
1616 | return btf_type_ops(resolved_type)->check_member(env, struct_type, | |
1617 | &resolved_member, | |
1618 | resolved_type); | |
1619 | } | |
1620 | ||
9d5f9f70 YS |
1621 | static int btf_modifier_check_kflag_member(struct btf_verifier_env *env, |
1622 | const struct btf_type *struct_type, | |
1623 | const struct btf_member *member, | |
1624 | const struct btf_type *member_type) | |
1625 | { | |
1626 | const struct btf_type *resolved_type; | |
1627 | u32 resolved_type_id = member->type; | |
1628 | struct btf_member resolved_member; | |
1629 | struct btf *btf = env->btf; | |
1630 | ||
1631 | resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); | |
1632 | if (!resolved_type) { | |
1633 | btf_verifier_log_member(env, struct_type, member, | |
1634 | "Invalid member"); | |
1635 | return -EINVAL; | |
1636 | } | |
1637 | ||
1638 | resolved_member = *member; | |
1639 | resolved_member.type = resolved_type_id; | |
1640 | ||
1641 | return btf_type_ops(resolved_type)->check_kflag_member(env, struct_type, | |
1642 | &resolved_member, | |
1643 | resolved_type); | |
1644 | } | |
1645 | ||
179cde8c MKL |
1646 | static int btf_ptr_check_member(struct btf_verifier_env *env, |
1647 | const struct btf_type *struct_type, | |
1648 | const struct btf_member *member, | |
1649 | const struct btf_type *member_type) | |
1650 | { | |
1651 | u32 struct_size, struct_bits_off, bytes_offset; | |
1652 | ||
1653 | struct_size = struct_type->size; | |
1654 | struct_bits_off = member->offset; | |
1655 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
1656 | ||
1657 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
1658 | btf_verifier_log_member(env, struct_type, member, | |
1659 | "Member is not byte aligned"); | |
1660 | return -EINVAL; | |
1661 | } | |
1662 | ||
1663 | if (struct_size - bytes_offset < sizeof(void *)) { | |
1664 | btf_verifier_log_member(env, struct_type, member, | |
1665 | "Member exceeds struct_size"); | |
1666 | return -EINVAL; | |
1667 | } | |
1668 | ||
1669 | return 0; | |
1670 | } | |
1671 | ||
69b693f0 MKL |
1672 | static int btf_ref_type_check_meta(struct btf_verifier_env *env, |
1673 | const struct btf_type *t, | |
1674 | u32 meta_left) | |
1675 | { | |
1676 | if (btf_type_vlen(t)) { | |
1677 | btf_verifier_log_type(env, t, "vlen != 0"); | |
1678 | return -EINVAL; | |
1679 | } | |
1680 | ||
9d5f9f70 YS |
1681 | if (btf_type_kflag(t)) { |
1682 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
1683 | return -EINVAL; | |
1684 | } | |
1685 | ||
aea2f7b8 | 1686 | if (!BTF_TYPE_ID_VALID(t->type)) { |
69b693f0 MKL |
1687 | btf_verifier_log_type(env, t, "Invalid type_id"); |
1688 | return -EINVAL; | |
1689 | } | |
1690 | ||
eb04bbb6 YS |
1691 | /* typedef type must have a valid name, and other ref types, |
1692 | * volatile, const, restrict, should have a null name. | |
1693 | */ | |
1694 | if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) { | |
1695 | if (!t->name_off || | |
1696 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
1697 | btf_verifier_log_type(env, t, "Invalid name"); | |
1698 | return -EINVAL; | |
1699 | } | |
1700 | } else { | |
1701 | if (t->name_off) { | |
1702 | btf_verifier_log_type(env, t, "Invalid name"); | |
1703 | return -EINVAL; | |
1704 | } | |
1705 | } | |
1706 | ||
69b693f0 MKL |
1707 | btf_verifier_log_type(env, t, NULL); |
1708 | ||
1709 | return 0; | |
1710 | } | |
1711 | ||
eb3f595d MKL |
1712 | static int btf_modifier_resolve(struct btf_verifier_env *env, |
1713 | const struct resolve_vertex *v) | |
1714 | { | |
1715 | const struct btf_type *t = v->t; | |
1716 | const struct btf_type *next_type; | |
1717 | u32 next_type_id = t->type; | |
1718 | struct btf *btf = env->btf; | |
eb3f595d MKL |
1719 | |
1720 | next_type = btf_type_by_id(btf, next_type_id); | |
1dc92851 | 1721 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
eb3f595d MKL |
1722 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
1723 | return -EINVAL; | |
1724 | } | |
1725 | ||
eb3f595d MKL |
1726 | if (!env_type_is_resolve_sink(env, next_type) && |
1727 | !env_type_is_resolved(env, next_type_id)) | |
1728 | return env_stack_push(env, next_type, next_type_id); | |
1729 | ||
1730 | /* Figure out the resolved next_type_id with size. | |
1731 | * They will be stored in the current modifier's | |
1732 | * resolved_ids and resolved_sizes such that it can | |
1733 | * save us a few type-following when we use it later (e.g. in | |
1734 | * pretty print). | |
1735 | */ | |
1acc5d5c | 1736 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
2667a262 MKL |
1737 | if (env_type_is_resolved(env, next_type_id)) |
1738 | next_type = btf_type_id_resolve(btf, &next_type_id); | |
1739 | ||
1740 | /* "typedef void new_void", "const void"...etc */ | |
1741 | if (!btf_type_is_void(next_type) && | |
81f5c6f5 YS |
1742 | !btf_type_is_fwd(next_type) && |
1743 | !btf_type_is_func_proto(next_type)) { | |
2667a262 MKL |
1744 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
1745 | return -EINVAL; | |
1746 | } | |
eb3f595d MKL |
1747 | } |
1748 | ||
1acc5d5c | 1749 | env_stack_pop_resolved(env, next_type_id, 0); |
eb3f595d MKL |
1750 | |
1751 | return 0; | |
1752 | } | |
1753 | ||
1dc92851 DB |
1754 | static int btf_var_resolve(struct btf_verifier_env *env, |
1755 | const struct resolve_vertex *v) | |
1756 | { | |
1757 | const struct btf_type *next_type; | |
1758 | const struct btf_type *t = v->t; | |
1759 | u32 next_type_id = t->type; | |
1760 | struct btf *btf = env->btf; | |
1dc92851 DB |
1761 | |
1762 | next_type = btf_type_by_id(btf, next_type_id); | |
1763 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { | |
1764 | btf_verifier_log_type(env, v->t, "Invalid type_id"); | |
1765 | return -EINVAL; | |
1766 | } | |
1767 | ||
1768 | if (!env_type_is_resolve_sink(env, next_type) && | |
1769 | !env_type_is_resolved(env, next_type_id)) | |
1770 | return env_stack_push(env, next_type, next_type_id); | |
1771 | ||
1772 | if (btf_type_is_modifier(next_type)) { | |
1773 | const struct btf_type *resolved_type; | |
1774 | u32 resolved_type_id; | |
1775 | ||
1776 | resolved_type_id = next_type_id; | |
1777 | resolved_type = btf_type_id_resolve(btf, &resolved_type_id); | |
1778 | ||
1779 | if (btf_type_is_ptr(resolved_type) && | |
1780 | !env_type_is_resolve_sink(env, resolved_type) && | |
1781 | !env_type_is_resolved(env, resolved_type_id)) | |
1782 | return env_stack_push(env, resolved_type, | |
1783 | resolved_type_id); | |
1784 | } | |
1785 | ||
1786 | /* We must resolve to something concrete at this point, no | |
1787 | * forward types or similar that would resolve to size of | |
1788 | * zero is allowed. | |
1789 | */ | |
1acc5d5c | 1790 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
1dc92851 DB |
1791 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
1792 | return -EINVAL; | |
1793 | } | |
1794 | ||
1acc5d5c | 1795 | env_stack_pop_resolved(env, next_type_id, 0); |
1dc92851 DB |
1796 | |
1797 | return 0; | |
1798 | } | |
1799 | ||
eb3f595d MKL |
1800 | static int btf_ptr_resolve(struct btf_verifier_env *env, |
1801 | const struct resolve_vertex *v) | |
1802 | { | |
1803 | const struct btf_type *next_type; | |
1804 | const struct btf_type *t = v->t; | |
1805 | u32 next_type_id = t->type; | |
1806 | struct btf *btf = env->btf; | |
eb3f595d MKL |
1807 | |
1808 | next_type = btf_type_by_id(btf, next_type_id); | |
1dc92851 | 1809 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
eb3f595d MKL |
1810 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
1811 | return -EINVAL; | |
1812 | } | |
1813 | ||
eb3f595d MKL |
1814 | if (!env_type_is_resolve_sink(env, next_type) && |
1815 | !env_type_is_resolved(env, next_type_id)) | |
1816 | return env_stack_push(env, next_type, next_type_id); | |
1817 | ||
1818 | /* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY, | |
1819 | * the modifier may have stopped resolving when it was resolved | |
1820 | * to a ptr (last-resolved-ptr). | |
1821 | * | |
1822 | * We now need to continue from the last-resolved-ptr to | |
1823 | * ensure the last-resolved-ptr will not referring back to | |
1824 | * the currenct ptr (t). | |
1825 | */ | |
1826 | if (btf_type_is_modifier(next_type)) { | |
1827 | const struct btf_type *resolved_type; | |
1828 | u32 resolved_type_id; | |
1829 | ||
1830 | resolved_type_id = next_type_id; | |
1831 | resolved_type = btf_type_id_resolve(btf, &resolved_type_id); | |
1832 | ||
1833 | if (btf_type_is_ptr(resolved_type) && | |
1834 | !env_type_is_resolve_sink(env, resolved_type) && | |
1835 | !env_type_is_resolved(env, resolved_type_id)) | |
1836 | return env_stack_push(env, resolved_type, | |
1837 | resolved_type_id); | |
1838 | } | |
1839 | ||
2667a262 MKL |
1840 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
1841 | if (env_type_is_resolved(env, next_type_id)) | |
1842 | next_type = btf_type_id_resolve(btf, &next_type_id); | |
1843 | ||
1844 | if (!btf_type_is_void(next_type) && | |
1845 | !btf_type_is_fwd(next_type) && | |
1846 | !btf_type_is_func_proto(next_type)) { | |
1847 | btf_verifier_log_type(env, v->t, "Invalid type_id"); | |
1848 | return -EINVAL; | |
1849 | } | |
eb3f595d MKL |
1850 | } |
1851 | ||
eb3f595d MKL |
1852 | env_stack_pop_resolved(env, next_type_id, 0); |
1853 | ||
1854 | return 0; | |
1855 | } | |
1856 | ||
b00b8dae MKL |
1857 | static void btf_modifier_seq_show(const struct btf *btf, |
1858 | const struct btf_type *t, | |
1859 | u32 type_id, void *data, | |
1860 | u8 bits_offset, struct seq_file *m) | |
1861 | { | |
85d33df3 MKL |
1862 | if (btf->resolved_ids) |
1863 | t = btf_type_id_resolve(btf, &type_id); | |
1864 | else | |
1865 | t = btf_type_skip_modifiers(btf, type_id, NULL); | |
b00b8dae MKL |
1866 | |
1867 | btf_type_ops(t)->seq_show(btf, t, type_id, data, bits_offset, m); | |
1868 | } | |
1869 | ||
1dc92851 DB |
1870 | static void btf_var_seq_show(const struct btf *btf, const struct btf_type *t, |
1871 | u32 type_id, void *data, u8 bits_offset, | |
1872 | struct seq_file *m) | |
1873 | { | |
1874 | t = btf_type_id_resolve(btf, &type_id); | |
1875 | ||
1876 | btf_type_ops(t)->seq_show(btf, t, type_id, data, bits_offset, m); | |
1877 | } | |
1878 | ||
b00b8dae MKL |
1879 | static void btf_ptr_seq_show(const struct btf *btf, const struct btf_type *t, |
1880 | u32 type_id, void *data, u8 bits_offset, | |
1881 | struct seq_file *m) | |
1882 | { | |
1883 | /* It is a hashed value */ | |
1884 | seq_printf(m, "%p", *(void **)data); | |
1885 | } | |
1886 | ||
69b693f0 MKL |
1887 | static void btf_ref_type_log(struct btf_verifier_env *env, |
1888 | const struct btf_type *t) | |
1889 | { | |
1890 | btf_verifier_log(env, "type_id=%u", t->type); | |
1891 | } | |
1892 | ||
1893 | static struct btf_kind_operations modifier_ops = { | |
1894 | .check_meta = btf_ref_type_check_meta, | |
eb3f595d | 1895 | .resolve = btf_modifier_resolve, |
179cde8c | 1896 | .check_member = btf_modifier_check_member, |
9d5f9f70 | 1897 | .check_kflag_member = btf_modifier_check_kflag_member, |
69b693f0 | 1898 | .log_details = btf_ref_type_log, |
b00b8dae | 1899 | .seq_show = btf_modifier_seq_show, |
69b693f0 MKL |
1900 | }; |
1901 | ||
1902 | static struct btf_kind_operations ptr_ops = { | |
1903 | .check_meta = btf_ref_type_check_meta, | |
eb3f595d | 1904 | .resolve = btf_ptr_resolve, |
179cde8c | 1905 | .check_member = btf_ptr_check_member, |
9d5f9f70 | 1906 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 1907 | .log_details = btf_ref_type_log, |
b00b8dae | 1908 | .seq_show = btf_ptr_seq_show, |
69b693f0 MKL |
1909 | }; |
1910 | ||
8175383f MKL |
1911 | static s32 btf_fwd_check_meta(struct btf_verifier_env *env, |
1912 | const struct btf_type *t, | |
1913 | u32 meta_left) | |
1914 | { | |
1915 | if (btf_type_vlen(t)) { | |
1916 | btf_verifier_log_type(env, t, "vlen != 0"); | |
1917 | return -EINVAL; | |
1918 | } | |
1919 | ||
1920 | if (t->type) { | |
1921 | btf_verifier_log_type(env, t, "type != 0"); | |
1922 | return -EINVAL; | |
1923 | } | |
1924 | ||
eb04bbb6 YS |
1925 | /* fwd type must have a valid name */ |
1926 | if (!t->name_off || | |
1927 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
1928 | btf_verifier_log_type(env, t, "Invalid name"); | |
1929 | return -EINVAL; | |
1930 | } | |
1931 | ||
8175383f MKL |
1932 | btf_verifier_log_type(env, t, NULL); |
1933 | ||
1934 | return 0; | |
1935 | } | |
1936 | ||
76c43ae8 YS |
1937 | static void btf_fwd_type_log(struct btf_verifier_env *env, |
1938 | const struct btf_type *t) | |
1939 | { | |
1940 | btf_verifier_log(env, "%s", btf_type_kflag(t) ? "union" : "struct"); | |
1941 | } | |
1942 | ||
69b693f0 | 1943 | static struct btf_kind_operations fwd_ops = { |
8175383f | 1944 | .check_meta = btf_fwd_check_meta, |
eb3f595d | 1945 | .resolve = btf_df_resolve, |
179cde8c | 1946 | .check_member = btf_df_check_member, |
9d5f9f70 | 1947 | .check_kflag_member = btf_df_check_kflag_member, |
76c43ae8 | 1948 | .log_details = btf_fwd_type_log, |
b00b8dae | 1949 | .seq_show = btf_df_seq_show, |
69b693f0 MKL |
1950 | }; |
1951 | ||
179cde8c MKL |
1952 | static int btf_array_check_member(struct btf_verifier_env *env, |
1953 | const struct btf_type *struct_type, | |
1954 | const struct btf_member *member, | |
1955 | const struct btf_type *member_type) | |
1956 | { | |
1957 | u32 struct_bits_off = member->offset; | |
1958 | u32 struct_size, bytes_offset; | |
1959 | u32 array_type_id, array_size; | |
1960 | struct btf *btf = env->btf; | |
1961 | ||
1962 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
1963 | btf_verifier_log_member(env, struct_type, member, | |
1964 | "Member is not byte aligned"); | |
1965 | return -EINVAL; | |
1966 | } | |
1967 | ||
1968 | array_type_id = member->type; | |
1969 | btf_type_id_size(btf, &array_type_id, &array_size); | |
1970 | struct_size = struct_type->size; | |
1971 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
1972 | if (struct_size - bytes_offset < array_size) { | |
1973 | btf_verifier_log_member(env, struct_type, member, | |
1974 | "Member exceeds struct_size"); | |
1975 | return -EINVAL; | |
1976 | } | |
1977 | ||
1978 | return 0; | |
1979 | } | |
1980 | ||
69b693f0 MKL |
1981 | static s32 btf_array_check_meta(struct btf_verifier_env *env, |
1982 | const struct btf_type *t, | |
1983 | u32 meta_left) | |
1984 | { | |
1985 | const struct btf_array *array = btf_type_array(t); | |
1986 | u32 meta_needed = sizeof(*array); | |
1987 | ||
1988 | if (meta_left < meta_needed) { | |
1989 | btf_verifier_log_basic(env, t, | |
1990 | "meta_left:%u meta_needed:%u", | |
1991 | meta_left, meta_needed); | |
1992 | return -EINVAL; | |
1993 | } | |
1994 | ||
eb04bbb6 YS |
1995 | /* array type should not have a name */ |
1996 | if (t->name_off) { | |
1997 | btf_verifier_log_type(env, t, "Invalid name"); | |
1998 | return -EINVAL; | |
1999 | } | |
2000 | ||
69b693f0 MKL |
2001 | if (btf_type_vlen(t)) { |
2002 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2003 | return -EINVAL; | |
2004 | } | |
2005 | ||
9d5f9f70 YS |
2006 | if (btf_type_kflag(t)) { |
2007 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2008 | return -EINVAL; | |
2009 | } | |
2010 | ||
b9308ae6 MKL |
2011 | if (t->size) { |
2012 | btf_verifier_log_type(env, t, "size != 0"); | |
2013 | return -EINVAL; | |
2014 | } | |
2015 | ||
4ef5f574 MKL |
2016 | /* Array elem type and index type cannot be in type void, |
2017 | * so !array->type and !array->index_type are not allowed. | |
69b693f0 | 2018 | */ |
aea2f7b8 | 2019 | if (!array->type || !BTF_TYPE_ID_VALID(array->type)) { |
4ef5f574 MKL |
2020 | btf_verifier_log_type(env, t, "Invalid elem"); |
2021 | return -EINVAL; | |
2022 | } | |
2023 | ||
aea2f7b8 | 2024 | if (!array->index_type || !BTF_TYPE_ID_VALID(array->index_type)) { |
4ef5f574 | 2025 | btf_verifier_log_type(env, t, "Invalid index"); |
69b693f0 MKL |
2026 | return -EINVAL; |
2027 | } | |
2028 | ||
2029 | btf_verifier_log_type(env, t, NULL); | |
2030 | ||
2031 | return meta_needed; | |
2032 | } | |
2033 | ||
eb3f595d MKL |
2034 | static int btf_array_resolve(struct btf_verifier_env *env, |
2035 | const struct resolve_vertex *v) | |
2036 | { | |
2037 | const struct btf_array *array = btf_type_array(v->t); | |
4ef5f574 MKL |
2038 | const struct btf_type *elem_type, *index_type; |
2039 | u32 elem_type_id, index_type_id; | |
eb3f595d MKL |
2040 | struct btf *btf = env->btf; |
2041 | u32 elem_size; | |
2042 | ||
4ef5f574 MKL |
2043 | /* Check array->index_type */ |
2044 | index_type_id = array->index_type; | |
2045 | index_type = btf_type_by_id(btf, index_type_id); | |
e4f07120 SF |
2046 | if (btf_type_nosize_or_null(index_type) || |
2047 | btf_type_is_resolve_source_only(index_type)) { | |
4ef5f574 MKL |
2048 | btf_verifier_log_type(env, v->t, "Invalid index"); |
2049 | return -EINVAL; | |
2050 | } | |
2051 | ||
2052 | if (!env_type_is_resolve_sink(env, index_type) && | |
2053 | !env_type_is_resolved(env, index_type_id)) | |
2054 | return env_stack_push(env, index_type, index_type_id); | |
2055 | ||
2056 | index_type = btf_type_id_size(btf, &index_type_id, NULL); | |
2057 | if (!index_type || !btf_type_is_int(index_type) || | |
2058 | !btf_type_int_is_regular(index_type)) { | |
2059 | btf_verifier_log_type(env, v->t, "Invalid index"); | |
2060 | return -EINVAL; | |
2061 | } | |
2062 | ||
2063 | /* Check array->type */ | |
2064 | elem_type_id = array->type; | |
eb3f595d | 2065 | elem_type = btf_type_by_id(btf, elem_type_id); |
e4f07120 SF |
2066 | if (btf_type_nosize_or_null(elem_type) || |
2067 | btf_type_is_resolve_source_only(elem_type)) { | |
eb3f595d MKL |
2068 | btf_verifier_log_type(env, v->t, |
2069 | "Invalid elem"); | |
2070 | return -EINVAL; | |
2071 | } | |
2072 | ||
2073 | if (!env_type_is_resolve_sink(env, elem_type) && | |
2074 | !env_type_is_resolved(env, elem_type_id)) | |
2075 | return env_stack_push(env, elem_type, elem_type_id); | |
2076 | ||
2077 | elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); | |
2078 | if (!elem_type) { | |
2079 | btf_verifier_log_type(env, v->t, "Invalid elem"); | |
2080 | return -EINVAL; | |
2081 | } | |
2082 | ||
4ef5f574 MKL |
2083 | if (btf_type_is_int(elem_type) && !btf_type_int_is_regular(elem_type)) { |
2084 | btf_verifier_log_type(env, v->t, "Invalid array of int"); | |
2085 | return -EINVAL; | |
eb3f595d MKL |
2086 | } |
2087 | ||
2088 | if (array->nelems && elem_size > U32_MAX / array->nelems) { | |
2089 | btf_verifier_log_type(env, v->t, | |
2090 | "Array size overflows U32_MAX"); | |
2091 | return -EINVAL; | |
2092 | } | |
2093 | ||
2094 | env_stack_pop_resolved(env, elem_type_id, elem_size * array->nelems); | |
2095 | ||
2096 | return 0; | |
2097 | } | |
2098 | ||
69b693f0 MKL |
2099 | static void btf_array_log(struct btf_verifier_env *env, |
2100 | const struct btf_type *t) | |
2101 | { | |
2102 | const struct btf_array *array = btf_type_array(t); | |
2103 | ||
2104 | btf_verifier_log(env, "type_id=%u index_type_id=%u nr_elems=%u", | |
2105 | array->type, array->index_type, array->nelems); | |
2106 | } | |
2107 | ||
b00b8dae MKL |
2108 | static void btf_array_seq_show(const struct btf *btf, const struct btf_type *t, |
2109 | u32 type_id, void *data, u8 bits_offset, | |
2110 | struct seq_file *m) | |
2111 | { | |
2112 | const struct btf_array *array = btf_type_array(t); | |
2113 | const struct btf_kind_operations *elem_ops; | |
2114 | const struct btf_type *elem_type; | |
2115 | u32 i, elem_size, elem_type_id; | |
2116 | ||
2117 | elem_type_id = array->type; | |
2118 | elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); | |
2119 | elem_ops = btf_type_ops(elem_type); | |
2120 | seq_puts(m, "["); | |
2121 | for (i = 0; i < array->nelems; i++) { | |
2122 | if (i) | |
2123 | seq_puts(m, ","); | |
2124 | ||
2125 | elem_ops->seq_show(btf, elem_type, elem_type_id, data, | |
2126 | bits_offset, m); | |
2127 | data += elem_size; | |
2128 | } | |
2129 | seq_puts(m, "]"); | |
2130 | } | |
2131 | ||
69b693f0 MKL |
2132 | static struct btf_kind_operations array_ops = { |
2133 | .check_meta = btf_array_check_meta, | |
eb3f595d | 2134 | .resolve = btf_array_resolve, |
179cde8c | 2135 | .check_member = btf_array_check_member, |
9d5f9f70 | 2136 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 2137 | .log_details = btf_array_log, |
b00b8dae | 2138 | .seq_show = btf_array_seq_show, |
69b693f0 MKL |
2139 | }; |
2140 | ||
179cde8c MKL |
2141 | static int btf_struct_check_member(struct btf_verifier_env *env, |
2142 | const struct btf_type *struct_type, | |
2143 | const struct btf_member *member, | |
2144 | const struct btf_type *member_type) | |
2145 | { | |
2146 | u32 struct_bits_off = member->offset; | |
2147 | u32 struct_size, bytes_offset; | |
2148 | ||
2149 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2150 | btf_verifier_log_member(env, struct_type, member, | |
2151 | "Member is not byte aligned"); | |
2152 | return -EINVAL; | |
2153 | } | |
2154 | ||
2155 | struct_size = struct_type->size; | |
2156 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2157 | if (struct_size - bytes_offset < member_type->size) { | |
2158 | btf_verifier_log_member(env, struct_type, member, | |
2159 | "Member exceeds struct_size"); | |
2160 | return -EINVAL; | |
2161 | } | |
2162 | ||
2163 | return 0; | |
2164 | } | |
2165 | ||
69b693f0 MKL |
2166 | static s32 btf_struct_check_meta(struct btf_verifier_env *env, |
2167 | const struct btf_type *t, | |
2168 | u32 meta_left) | |
2169 | { | |
2170 | bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION; | |
2171 | const struct btf_member *member; | |
6283fa38 | 2172 | u32 meta_needed, last_offset; |
69b693f0 MKL |
2173 | struct btf *btf = env->btf; |
2174 | u32 struct_size = t->size; | |
9d5f9f70 | 2175 | u32 offset; |
69b693f0 MKL |
2176 | u16 i; |
2177 | ||
2178 | meta_needed = btf_type_vlen(t) * sizeof(*member); | |
2179 | if (meta_left < meta_needed) { | |
2180 | btf_verifier_log_basic(env, t, | |
2181 | "meta_left:%u meta_needed:%u", | |
2182 | meta_left, meta_needed); | |
2183 | return -EINVAL; | |
2184 | } | |
2185 | ||
eb04bbb6 YS |
2186 | /* struct type either no name or a valid one */ |
2187 | if (t->name_off && | |
2188 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
2189 | btf_verifier_log_type(env, t, "Invalid name"); | |
2190 | return -EINVAL; | |
2191 | } | |
2192 | ||
69b693f0 MKL |
2193 | btf_verifier_log_type(env, t, NULL); |
2194 | ||
6283fa38 | 2195 | last_offset = 0; |
69b693f0 | 2196 | for_each_member(i, t, member) { |
fbcf93eb | 2197 | if (!btf_name_offset_valid(btf, member->name_off)) { |
69b693f0 MKL |
2198 | btf_verifier_log_member(env, t, member, |
2199 | "Invalid member name_offset:%u", | |
fbcf93eb | 2200 | member->name_off); |
69b693f0 MKL |
2201 | return -EINVAL; |
2202 | } | |
2203 | ||
eb04bbb6 YS |
2204 | /* struct member either no name or a valid one */ |
2205 | if (member->name_off && | |
2206 | !btf_name_valid_identifier(btf, member->name_off)) { | |
2207 | btf_verifier_log_member(env, t, member, "Invalid name"); | |
2208 | return -EINVAL; | |
2209 | } | |
69b693f0 | 2210 | /* A member cannot be in type void */ |
aea2f7b8 | 2211 | if (!member->type || !BTF_TYPE_ID_VALID(member->type)) { |
69b693f0 MKL |
2212 | btf_verifier_log_member(env, t, member, |
2213 | "Invalid type_id"); | |
2214 | return -EINVAL; | |
2215 | } | |
2216 | ||
9d5f9f70 YS |
2217 | offset = btf_member_bit_offset(t, member); |
2218 | if (is_union && offset) { | |
69b693f0 MKL |
2219 | btf_verifier_log_member(env, t, member, |
2220 | "Invalid member bits_offset"); | |
2221 | return -EINVAL; | |
2222 | } | |
2223 | ||
6283fa38 MKL |
2224 | /* |
2225 | * ">" instead of ">=" because the last member could be | |
2226 | * "char a[0];" | |
2227 | */ | |
9d5f9f70 | 2228 | if (last_offset > offset) { |
6283fa38 MKL |
2229 | btf_verifier_log_member(env, t, member, |
2230 | "Invalid member bits_offset"); | |
2231 | return -EINVAL; | |
2232 | } | |
2233 | ||
9d5f9f70 | 2234 | if (BITS_ROUNDUP_BYTES(offset) > struct_size) { |
69b693f0 | 2235 | btf_verifier_log_member(env, t, member, |
311fe1a8 | 2236 | "Member bits_offset exceeds its struct size"); |
69b693f0 MKL |
2237 | return -EINVAL; |
2238 | } | |
2239 | ||
2240 | btf_verifier_log_member(env, t, member, NULL); | |
9d5f9f70 | 2241 | last_offset = offset; |
69b693f0 MKL |
2242 | } |
2243 | ||
2244 | return meta_needed; | |
2245 | } | |
2246 | ||
eb3f595d MKL |
2247 | static int btf_struct_resolve(struct btf_verifier_env *env, |
2248 | const struct resolve_vertex *v) | |
2249 | { | |
2250 | const struct btf_member *member; | |
179cde8c | 2251 | int err; |
eb3f595d MKL |
2252 | u16 i; |
2253 | ||
2254 | /* Before continue resolving the next_member, | |
2255 | * ensure the last member is indeed resolved to a | |
2256 | * type with size info. | |
2257 | */ | |
2258 | if (v->next_member) { | |
179cde8c | 2259 | const struct btf_type *last_member_type; |
eb3f595d MKL |
2260 | const struct btf_member *last_member; |
2261 | u16 last_member_type_id; | |
2262 | ||
2263 | last_member = btf_type_member(v->t) + v->next_member - 1; | |
2264 | last_member_type_id = last_member->type; | |
2265 | if (WARN_ON_ONCE(!env_type_is_resolved(env, | |
2266 | last_member_type_id))) | |
2267 | return -EINVAL; | |
179cde8c MKL |
2268 | |
2269 | last_member_type = btf_type_by_id(env->btf, | |
2270 | last_member_type_id); | |
9d5f9f70 YS |
2271 | if (btf_type_kflag(v->t)) |
2272 | err = btf_type_ops(last_member_type)->check_kflag_member(env, v->t, | |
2273 | last_member, | |
2274 | last_member_type); | |
2275 | else | |
2276 | err = btf_type_ops(last_member_type)->check_member(env, v->t, | |
2277 | last_member, | |
2278 | last_member_type); | |
179cde8c MKL |
2279 | if (err) |
2280 | return err; | |
eb3f595d MKL |
2281 | } |
2282 | ||
2283 | for_each_member_from(i, v->next_member, v->t, member) { | |
2284 | u32 member_type_id = member->type; | |
2285 | const struct btf_type *member_type = btf_type_by_id(env->btf, | |
2286 | member_type_id); | |
2287 | ||
e4f07120 SF |
2288 | if (btf_type_nosize_or_null(member_type) || |
2289 | btf_type_is_resolve_source_only(member_type)) { | |
eb3f595d MKL |
2290 | btf_verifier_log_member(env, v->t, member, |
2291 | "Invalid member"); | |
2292 | return -EINVAL; | |
2293 | } | |
2294 | ||
2295 | if (!env_type_is_resolve_sink(env, member_type) && | |
2296 | !env_type_is_resolved(env, member_type_id)) { | |
2297 | env_stack_set_next_member(env, i + 1); | |
2298 | return env_stack_push(env, member_type, member_type_id); | |
2299 | } | |
179cde8c | 2300 | |
9d5f9f70 YS |
2301 | if (btf_type_kflag(v->t)) |
2302 | err = btf_type_ops(member_type)->check_kflag_member(env, v->t, | |
2303 | member, | |
2304 | member_type); | |
2305 | else | |
2306 | err = btf_type_ops(member_type)->check_member(env, v->t, | |
2307 | member, | |
2308 | member_type); | |
179cde8c MKL |
2309 | if (err) |
2310 | return err; | |
eb3f595d MKL |
2311 | } |
2312 | ||
2313 | env_stack_pop_resolved(env, 0, 0); | |
2314 | ||
2315 | return 0; | |
2316 | } | |
2317 | ||
69b693f0 MKL |
2318 | static void btf_struct_log(struct btf_verifier_env *env, |
2319 | const struct btf_type *t) | |
2320 | { | |
2321 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
2322 | } | |
2323 | ||
d83525ca AS |
2324 | /* find 'struct bpf_spin_lock' in map value. |
2325 | * return >= 0 offset if found | |
2326 | * and < 0 in case of error | |
2327 | */ | |
2328 | int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t) | |
2329 | { | |
2330 | const struct btf_member *member; | |
2331 | u32 i, off = -ENOENT; | |
2332 | ||
2333 | if (!__btf_type_is_struct(t)) | |
2334 | return -EINVAL; | |
2335 | ||
2336 | for_each_member(i, t, member) { | |
2337 | const struct btf_type *member_type = btf_type_by_id(btf, | |
2338 | member->type); | |
2339 | if (!__btf_type_is_struct(member_type)) | |
2340 | continue; | |
2341 | if (member_type->size != sizeof(struct bpf_spin_lock)) | |
2342 | continue; | |
2343 | if (strcmp(__btf_name_by_offset(btf, member_type->name_off), | |
2344 | "bpf_spin_lock")) | |
2345 | continue; | |
2346 | if (off != -ENOENT) | |
2347 | /* only one 'struct bpf_spin_lock' is allowed */ | |
2348 | return -E2BIG; | |
2349 | off = btf_member_bit_offset(t, member); | |
2350 | if (off % 8) | |
2351 | /* valid C code cannot generate such BTF */ | |
2352 | return -EINVAL; | |
2353 | off /= 8; | |
2354 | if (off % __alignof__(struct bpf_spin_lock)) | |
2355 | /* valid struct bpf_spin_lock will be 4 byte aligned */ | |
2356 | return -EINVAL; | |
2357 | } | |
2358 | return off; | |
2359 | } | |
2360 | ||
b00b8dae MKL |
2361 | static void btf_struct_seq_show(const struct btf *btf, const struct btf_type *t, |
2362 | u32 type_id, void *data, u8 bits_offset, | |
2363 | struct seq_file *m) | |
2364 | { | |
2365 | const char *seq = BTF_INFO_KIND(t->info) == BTF_KIND_UNION ? "|" : ","; | |
2366 | const struct btf_member *member; | |
2367 | u32 i; | |
2368 | ||
2369 | seq_puts(m, "{"); | |
2370 | for_each_member(i, t, member) { | |
2371 | const struct btf_type *member_type = btf_type_by_id(btf, | |
2372 | member->type); | |
b00b8dae | 2373 | const struct btf_kind_operations *ops; |
9d5f9f70 YS |
2374 | u32 member_offset, bitfield_size; |
2375 | u32 bytes_offset; | |
2376 | u8 bits8_offset; | |
b00b8dae MKL |
2377 | |
2378 | if (i) | |
2379 | seq_puts(m, seq); | |
2380 | ||
9d5f9f70 YS |
2381 | member_offset = btf_member_bit_offset(t, member); |
2382 | bitfield_size = btf_member_bitfield_size(t, member); | |
17e3ac81 YS |
2383 | bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset); |
2384 | bits8_offset = BITS_PER_BYTE_MASKED(member_offset); | |
9d5f9f70 | 2385 | if (bitfield_size) { |
17e3ac81 | 2386 | btf_bitfield_seq_show(data + bytes_offset, bits8_offset, |
9d5f9f70 YS |
2387 | bitfield_size, m); |
2388 | } else { | |
9d5f9f70 YS |
2389 | ops = btf_type_ops(member_type); |
2390 | ops->seq_show(btf, member_type, member->type, | |
2391 | data + bytes_offset, bits8_offset, m); | |
2392 | } | |
b00b8dae MKL |
2393 | } |
2394 | seq_puts(m, "}"); | |
2395 | } | |
2396 | ||
69b693f0 MKL |
2397 | static struct btf_kind_operations struct_ops = { |
2398 | .check_meta = btf_struct_check_meta, | |
eb3f595d | 2399 | .resolve = btf_struct_resolve, |
179cde8c | 2400 | .check_member = btf_struct_check_member, |
9d5f9f70 | 2401 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 2402 | .log_details = btf_struct_log, |
b00b8dae | 2403 | .seq_show = btf_struct_seq_show, |
69b693f0 MKL |
2404 | }; |
2405 | ||
179cde8c MKL |
2406 | static int btf_enum_check_member(struct btf_verifier_env *env, |
2407 | const struct btf_type *struct_type, | |
2408 | const struct btf_member *member, | |
2409 | const struct btf_type *member_type) | |
2410 | { | |
2411 | u32 struct_bits_off = member->offset; | |
2412 | u32 struct_size, bytes_offset; | |
2413 | ||
2414 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2415 | btf_verifier_log_member(env, struct_type, member, | |
2416 | "Member is not byte aligned"); | |
2417 | return -EINVAL; | |
2418 | } | |
2419 | ||
2420 | struct_size = struct_type->size; | |
2421 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
da6c7fae | 2422 | if (struct_size - bytes_offset < member_type->size) { |
179cde8c MKL |
2423 | btf_verifier_log_member(env, struct_type, member, |
2424 | "Member exceeds struct_size"); | |
2425 | return -EINVAL; | |
2426 | } | |
2427 | ||
2428 | return 0; | |
2429 | } | |
2430 | ||
9d5f9f70 YS |
2431 | static int btf_enum_check_kflag_member(struct btf_verifier_env *env, |
2432 | const struct btf_type *struct_type, | |
2433 | const struct btf_member *member, | |
2434 | const struct btf_type *member_type) | |
2435 | { | |
2436 | u32 struct_bits_off, nr_bits, bytes_end, struct_size; | |
2437 | u32 int_bitsize = sizeof(int) * BITS_PER_BYTE; | |
2438 | ||
2439 | struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); | |
2440 | nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); | |
2441 | if (!nr_bits) { | |
2442 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2443 | btf_verifier_log_member(env, struct_type, member, | |
2444 | "Member is not byte aligned"); | |
e3439af4 | 2445 | return -EINVAL; |
9d5f9f70 YS |
2446 | } |
2447 | ||
2448 | nr_bits = int_bitsize; | |
2449 | } else if (nr_bits > int_bitsize) { | |
2450 | btf_verifier_log_member(env, struct_type, member, | |
2451 | "Invalid member bitfield_size"); | |
2452 | return -EINVAL; | |
2453 | } | |
2454 | ||
2455 | struct_size = struct_type->size; | |
2456 | bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits); | |
2457 | if (struct_size < bytes_end) { | |
2458 | btf_verifier_log_member(env, struct_type, member, | |
2459 | "Member exceeds struct_size"); | |
2460 | return -EINVAL; | |
2461 | } | |
2462 | ||
2463 | return 0; | |
2464 | } | |
2465 | ||
69b693f0 MKL |
2466 | static s32 btf_enum_check_meta(struct btf_verifier_env *env, |
2467 | const struct btf_type *t, | |
2468 | u32 meta_left) | |
2469 | { | |
2470 | const struct btf_enum *enums = btf_type_enum(t); | |
2471 | struct btf *btf = env->btf; | |
2472 | u16 i, nr_enums; | |
2473 | u32 meta_needed; | |
2474 | ||
2475 | nr_enums = btf_type_vlen(t); | |
2476 | meta_needed = nr_enums * sizeof(*enums); | |
2477 | ||
2478 | if (meta_left < meta_needed) { | |
2479 | btf_verifier_log_basic(env, t, | |
2480 | "meta_left:%u meta_needed:%u", | |
2481 | meta_left, meta_needed); | |
2482 | return -EINVAL; | |
2483 | } | |
2484 | ||
9d5f9f70 YS |
2485 | if (btf_type_kflag(t)) { |
2486 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2487 | return -EINVAL; | |
2488 | } | |
2489 | ||
9eea9849 AS |
2490 | if (t->size > 8 || !is_power_of_2(t->size)) { |
2491 | btf_verifier_log_type(env, t, "Unexpected size"); | |
69b693f0 MKL |
2492 | return -EINVAL; |
2493 | } | |
2494 | ||
eb04bbb6 YS |
2495 | /* enum type either no name or a valid one */ |
2496 | if (t->name_off && | |
2497 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
2498 | btf_verifier_log_type(env, t, "Invalid name"); | |
2499 | return -EINVAL; | |
2500 | } | |
2501 | ||
69b693f0 MKL |
2502 | btf_verifier_log_type(env, t, NULL); |
2503 | ||
2504 | for (i = 0; i < nr_enums; i++) { | |
fbcf93eb | 2505 | if (!btf_name_offset_valid(btf, enums[i].name_off)) { |
69b693f0 | 2506 | btf_verifier_log(env, "\tInvalid name_offset:%u", |
fbcf93eb | 2507 | enums[i].name_off); |
69b693f0 MKL |
2508 | return -EINVAL; |
2509 | } | |
2510 | ||
eb04bbb6 YS |
2511 | /* enum member must have a valid name */ |
2512 | if (!enums[i].name_off || | |
2513 | !btf_name_valid_identifier(btf, enums[i].name_off)) { | |
2514 | btf_verifier_log_type(env, t, "Invalid name"); | |
2515 | return -EINVAL; | |
2516 | } | |
2517 | ||
8580ac94 AS |
2518 | if (env->log.level == BPF_LOG_KERNEL) |
2519 | continue; | |
69b693f0 | 2520 | btf_verifier_log(env, "\t%s val=%d\n", |
23127b33 | 2521 | __btf_name_by_offset(btf, enums[i].name_off), |
69b693f0 MKL |
2522 | enums[i].val); |
2523 | } | |
2524 | ||
2525 | return meta_needed; | |
2526 | } | |
2527 | ||
2528 | static void btf_enum_log(struct btf_verifier_env *env, | |
2529 | const struct btf_type *t) | |
2530 | { | |
2531 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
2532 | } | |
2533 | ||
b00b8dae MKL |
2534 | static void btf_enum_seq_show(const struct btf *btf, const struct btf_type *t, |
2535 | u32 type_id, void *data, u8 bits_offset, | |
2536 | struct seq_file *m) | |
2537 | { | |
2538 | const struct btf_enum *enums = btf_type_enum(t); | |
2539 | u32 i, nr_enums = btf_type_vlen(t); | |
2540 | int v = *(int *)data; | |
2541 | ||
2542 | for (i = 0; i < nr_enums; i++) { | |
2543 | if (v == enums[i].val) { | |
2544 | seq_printf(m, "%s", | |
23127b33 MKL |
2545 | __btf_name_by_offset(btf, |
2546 | enums[i].name_off)); | |
b00b8dae MKL |
2547 | return; |
2548 | } | |
2549 | } | |
2550 | ||
2551 | seq_printf(m, "%d", v); | |
2552 | } | |
2553 | ||
69b693f0 MKL |
2554 | static struct btf_kind_operations enum_ops = { |
2555 | .check_meta = btf_enum_check_meta, | |
eb3f595d | 2556 | .resolve = btf_df_resolve, |
179cde8c | 2557 | .check_member = btf_enum_check_member, |
9d5f9f70 | 2558 | .check_kflag_member = btf_enum_check_kflag_member, |
69b693f0 | 2559 | .log_details = btf_enum_log, |
b00b8dae | 2560 | .seq_show = btf_enum_seq_show, |
69b693f0 MKL |
2561 | }; |
2562 | ||
2667a262 MKL |
2563 | static s32 btf_func_proto_check_meta(struct btf_verifier_env *env, |
2564 | const struct btf_type *t, | |
2565 | u32 meta_left) | |
2566 | { | |
2567 | u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param); | |
2568 | ||
2569 | if (meta_left < meta_needed) { | |
2570 | btf_verifier_log_basic(env, t, | |
2571 | "meta_left:%u meta_needed:%u", | |
2572 | meta_left, meta_needed); | |
2573 | return -EINVAL; | |
2574 | } | |
2575 | ||
2576 | if (t->name_off) { | |
2577 | btf_verifier_log_type(env, t, "Invalid name"); | |
2578 | return -EINVAL; | |
2579 | } | |
2580 | ||
9d5f9f70 YS |
2581 | if (btf_type_kflag(t)) { |
2582 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2583 | return -EINVAL; | |
2584 | } | |
2585 | ||
2667a262 MKL |
2586 | btf_verifier_log_type(env, t, NULL); |
2587 | ||
2588 | return meta_needed; | |
2589 | } | |
2590 | ||
2591 | static void btf_func_proto_log(struct btf_verifier_env *env, | |
2592 | const struct btf_type *t) | |
2593 | { | |
2594 | const struct btf_param *args = (const struct btf_param *)(t + 1); | |
2595 | u16 nr_args = btf_type_vlen(t), i; | |
2596 | ||
2597 | btf_verifier_log(env, "return=%u args=(", t->type); | |
2598 | if (!nr_args) { | |
2599 | btf_verifier_log(env, "void"); | |
2600 | goto done; | |
2601 | } | |
2602 | ||
2603 | if (nr_args == 1 && !args[0].type) { | |
2604 | /* Only one vararg */ | |
2605 | btf_verifier_log(env, "vararg"); | |
2606 | goto done; | |
2607 | } | |
2608 | ||
2609 | btf_verifier_log(env, "%u %s", args[0].type, | |
23127b33 MKL |
2610 | __btf_name_by_offset(env->btf, |
2611 | args[0].name_off)); | |
2667a262 MKL |
2612 | for (i = 1; i < nr_args - 1; i++) |
2613 | btf_verifier_log(env, ", %u %s", args[i].type, | |
23127b33 MKL |
2614 | __btf_name_by_offset(env->btf, |
2615 | args[i].name_off)); | |
2667a262 MKL |
2616 | |
2617 | if (nr_args > 1) { | |
2618 | const struct btf_param *last_arg = &args[nr_args - 1]; | |
2619 | ||
2620 | if (last_arg->type) | |
2621 | btf_verifier_log(env, ", %u %s", last_arg->type, | |
23127b33 MKL |
2622 | __btf_name_by_offset(env->btf, |
2623 | last_arg->name_off)); | |
2667a262 MKL |
2624 | else |
2625 | btf_verifier_log(env, ", vararg"); | |
2626 | } | |
2627 | ||
2628 | done: | |
2629 | btf_verifier_log(env, ")"); | |
2630 | } | |
2631 | ||
2632 | static struct btf_kind_operations func_proto_ops = { | |
2633 | .check_meta = btf_func_proto_check_meta, | |
2634 | .resolve = btf_df_resolve, | |
2635 | /* | |
2636 | * BTF_KIND_FUNC_PROTO cannot be directly referred by | |
2637 | * a struct's member. | |
2638 | * | |
2639 | * It should be a funciton pointer instead. | |
2640 | * (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO) | |
2641 | * | |
2642 | * Hence, there is no btf_func_check_member(). | |
2643 | */ | |
2644 | .check_member = btf_df_check_member, | |
9d5f9f70 | 2645 | .check_kflag_member = btf_df_check_kflag_member, |
2667a262 MKL |
2646 | .log_details = btf_func_proto_log, |
2647 | .seq_show = btf_df_seq_show, | |
2648 | }; | |
2649 | ||
2650 | static s32 btf_func_check_meta(struct btf_verifier_env *env, | |
2651 | const struct btf_type *t, | |
2652 | u32 meta_left) | |
2653 | { | |
2654 | if (!t->name_off || | |
2655 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
2656 | btf_verifier_log_type(env, t, "Invalid name"); | |
2657 | return -EINVAL; | |
2658 | } | |
2659 | ||
51c39bb1 AS |
2660 | if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) { |
2661 | btf_verifier_log_type(env, t, "Invalid func linkage"); | |
2667a262 MKL |
2662 | return -EINVAL; |
2663 | } | |
2664 | ||
9d5f9f70 YS |
2665 | if (btf_type_kflag(t)) { |
2666 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2667 | return -EINVAL; | |
2668 | } | |
2669 | ||
2667a262 MKL |
2670 | btf_verifier_log_type(env, t, NULL); |
2671 | ||
2672 | return 0; | |
2673 | } | |
2674 | ||
2675 | static struct btf_kind_operations func_ops = { | |
2676 | .check_meta = btf_func_check_meta, | |
2677 | .resolve = btf_df_resolve, | |
2678 | .check_member = btf_df_check_member, | |
9d5f9f70 | 2679 | .check_kflag_member = btf_df_check_kflag_member, |
2667a262 MKL |
2680 | .log_details = btf_ref_type_log, |
2681 | .seq_show = btf_df_seq_show, | |
2682 | }; | |
2683 | ||
1dc92851 DB |
2684 | static s32 btf_var_check_meta(struct btf_verifier_env *env, |
2685 | const struct btf_type *t, | |
2686 | u32 meta_left) | |
2687 | { | |
2688 | const struct btf_var *var; | |
2689 | u32 meta_needed = sizeof(*var); | |
2690 | ||
2691 | if (meta_left < meta_needed) { | |
2692 | btf_verifier_log_basic(env, t, | |
2693 | "meta_left:%u meta_needed:%u", | |
2694 | meta_left, meta_needed); | |
2695 | return -EINVAL; | |
2696 | } | |
2697 | ||
2698 | if (btf_type_vlen(t)) { | |
2699 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2700 | return -EINVAL; | |
2701 | } | |
2702 | ||
2703 | if (btf_type_kflag(t)) { | |
2704 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2705 | return -EINVAL; | |
2706 | } | |
2707 | ||
2708 | if (!t->name_off || | |
2709 | !__btf_name_valid(env->btf, t->name_off, true)) { | |
2710 | btf_verifier_log_type(env, t, "Invalid name"); | |
2711 | return -EINVAL; | |
2712 | } | |
2713 | ||
2714 | /* A var cannot be in type void */ | |
2715 | if (!t->type || !BTF_TYPE_ID_VALID(t->type)) { | |
2716 | btf_verifier_log_type(env, t, "Invalid type_id"); | |
2717 | return -EINVAL; | |
2718 | } | |
2719 | ||
2720 | var = btf_type_var(t); | |
2721 | if (var->linkage != BTF_VAR_STATIC && | |
2722 | var->linkage != BTF_VAR_GLOBAL_ALLOCATED) { | |
2723 | btf_verifier_log_type(env, t, "Linkage not supported"); | |
2724 | return -EINVAL; | |
2725 | } | |
2726 | ||
2727 | btf_verifier_log_type(env, t, NULL); | |
2728 | ||
2729 | return meta_needed; | |
2730 | } | |
2731 | ||
2732 | static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t) | |
2733 | { | |
2734 | const struct btf_var *var = btf_type_var(t); | |
2735 | ||
2736 | btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage); | |
2737 | } | |
2738 | ||
2739 | static const struct btf_kind_operations var_ops = { | |
2740 | .check_meta = btf_var_check_meta, | |
2741 | .resolve = btf_var_resolve, | |
2742 | .check_member = btf_df_check_member, | |
2743 | .check_kflag_member = btf_df_check_kflag_member, | |
2744 | .log_details = btf_var_log, | |
2745 | .seq_show = btf_var_seq_show, | |
2746 | }; | |
2747 | ||
2748 | static s32 btf_datasec_check_meta(struct btf_verifier_env *env, | |
2749 | const struct btf_type *t, | |
2750 | u32 meta_left) | |
2751 | { | |
2752 | const struct btf_var_secinfo *vsi; | |
2753 | u64 last_vsi_end_off = 0, sum = 0; | |
2754 | u32 i, meta_needed; | |
2755 | ||
2756 | meta_needed = btf_type_vlen(t) * sizeof(*vsi); | |
2757 | if (meta_left < meta_needed) { | |
2758 | btf_verifier_log_basic(env, t, | |
2759 | "meta_left:%u meta_needed:%u", | |
2760 | meta_left, meta_needed); | |
2761 | return -EINVAL; | |
2762 | } | |
2763 | ||
2764 | if (!btf_type_vlen(t)) { | |
2765 | btf_verifier_log_type(env, t, "vlen == 0"); | |
2766 | return -EINVAL; | |
2767 | } | |
2768 | ||
2769 | if (!t->size) { | |
2770 | btf_verifier_log_type(env, t, "size == 0"); | |
2771 | return -EINVAL; | |
2772 | } | |
2773 | ||
2774 | if (btf_type_kflag(t)) { | |
2775 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2776 | return -EINVAL; | |
2777 | } | |
2778 | ||
2779 | if (!t->name_off || | |
2780 | !btf_name_valid_section(env->btf, t->name_off)) { | |
2781 | btf_verifier_log_type(env, t, "Invalid name"); | |
2782 | return -EINVAL; | |
2783 | } | |
2784 | ||
2785 | btf_verifier_log_type(env, t, NULL); | |
2786 | ||
2787 | for_each_vsi(i, t, vsi) { | |
2788 | /* A var cannot be in type void */ | |
2789 | if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) { | |
2790 | btf_verifier_log_vsi(env, t, vsi, | |
2791 | "Invalid type_id"); | |
2792 | return -EINVAL; | |
2793 | } | |
2794 | ||
2795 | if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) { | |
2796 | btf_verifier_log_vsi(env, t, vsi, | |
2797 | "Invalid offset"); | |
2798 | return -EINVAL; | |
2799 | } | |
2800 | ||
2801 | if (!vsi->size || vsi->size > t->size) { | |
2802 | btf_verifier_log_vsi(env, t, vsi, | |
2803 | "Invalid size"); | |
2804 | return -EINVAL; | |
2805 | } | |
2806 | ||
2807 | last_vsi_end_off = vsi->offset + vsi->size; | |
2808 | if (last_vsi_end_off > t->size) { | |
2809 | btf_verifier_log_vsi(env, t, vsi, | |
2810 | "Invalid offset+size"); | |
2811 | return -EINVAL; | |
2812 | } | |
2813 | ||
2814 | btf_verifier_log_vsi(env, t, vsi, NULL); | |
2815 | sum += vsi->size; | |
2816 | } | |
2817 | ||
2818 | if (t->size < sum) { | |
2819 | btf_verifier_log_type(env, t, "Invalid btf_info size"); | |
2820 | return -EINVAL; | |
2821 | } | |
2822 | ||
2823 | return meta_needed; | |
2824 | } | |
2825 | ||
2826 | static int btf_datasec_resolve(struct btf_verifier_env *env, | |
2827 | const struct resolve_vertex *v) | |
2828 | { | |
2829 | const struct btf_var_secinfo *vsi; | |
2830 | struct btf *btf = env->btf; | |
2831 | u16 i; | |
2832 | ||
2833 | for_each_vsi_from(i, v->next_member, v->t, vsi) { | |
2834 | u32 var_type_id = vsi->type, type_id, type_size = 0; | |
2835 | const struct btf_type *var_type = btf_type_by_id(env->btf, | |
2836 | var_type_id); | |
2837 | if (!var_type || !btf_type_is_var(var_type)) { | |
2838 | btf_verifier_log_vsi(env, v->t, vsi, | |
2839 | "Not a VAR kind member"); | |
2840 | return -EINVAL; | |
2841 | } | |
2842 | ||
2843 | if (!env_type_is_resolve_sink(env, var_type) && | |
2844 | !env_type_is_resolved(env, var_type_id)) { | |
2845 | env_stack_set_next_member(env, i + 1); | |
2846 | return env_stack_push(env, var_type, var_type_id); | |
2847 | } | |
2848 | ||
2849 | type_id = var_type->type; | |
2850 | if (!btf_type_id_size(btf, &type_id, &type_size)) { | |
2851 | btf_verifier_log_vsi(env, v->t, vsi, "Invalid type"); | |
2852 | return -EINVAL; | |
2853 | } | |
2854 | ||
2855 | if (vsi->size < type_size) { | |
2856 | btf_verifier_log_vsi(env, v->t, vsi, "Invalid size"); | |
2857 | return -EINVAL; | |
2858 | } | |
2859 | } | |
2860 | ||
2861 | env_stack_pop_resolved(env, 0, 0); | |
2862 | return 0; | |
2863 | } | |
2864 | ||
2865 | static void btf_datasec_log(struct btf_verifier_env *env, | |
2866 | const struct btf_type *t) | |
2867 | { | |
2868 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
2869 | } | |
2870 | ||
2871 | static void btf_datasec_seq_show(const struct btf *btf, | |
2872 | const struct btf_type *t, u32 type_id, | |
2873 | void *data, u8 bits_offset, | |
2874 | struct seq_file *m) | |
2875 | { | |
2876 | const struct btf_var_secinfo *vsi; | |
2877 | const struct btf_type *var; | |
2878 | u32 i; | |
2879 | ||
2880 | seq_printf(m, "section (\"%s\") = {", __btf_name_by_offset(btf, t->name_off)); | |
2881 | for_each_vsi(i, t, vsi) { | |
2882 | var = btf_type_by_id(btf, vsi->type); | |
2883 | if (i) | |
2884 | seq_puts(m, ","); | |
2885 | btf_type_ops(var)->seq_show(btf, var, vsi->type, | |
2886 | data + vsi->offset, bits_offset, m); | |
2887 | } | |
2888 | seq_puts(m, "}"); | |
2889 | } | |
2890 | ||
2891 | static const struct btf_kind_operations datasec_ops = { | |
2892 | .check_meta = btf_datasec_check_meta, | |
2893 | .resolve = btf_datasec_resolve, | |
2894 | .check_member = btf_df_check_member, | |
2895 | .check_kflag_member = btf_df_check_kflag_member, | |
2896 | .log_details = btf_datasec_log, | |
2897 | .seq_show = btf_datasec_seq_show, | |
2898 | }; | |
2899 | ||
2667a262 MKL |
2900 | static int btf_func_proto_check(struct btf_verifier_env *env, |
2901 | const struct btf_type *t) | |
2902 | { | |
2903 | const struct btf_type *ret_type; | |
2904 | const struct btf_param *args; | |
2905 | const struct btf *btf; | |
2906 | u16 nr_args, i; | |
2907 | int err; | |
2908 | ||
2909 | btf = env->btf; | |
2910 | args = (const struct btf_param *)(t + 1); | |
2911 | nr_args = btf_type_vlen(t); | |
2912 | ||
2913 | /* Check func return type which could be "void" (t->type == 0) */ | |
2914 | if (t->type) { | |
2915 | u32 ret_type_id = t->type; | |
2916 | ||
2917 | ret_type = btf_type_by_id(btf, ret_type_id); | |
2918 | if (!ret_type) { | |
2919 | btf_verifier_log_type(env, t, "Invalid return type"); | |
2920 | return -EINVAL; | |
2921 | } | |
2922 | ||
2923 | if (btf_type_needs_resolve(ret_type) && | |
2924 | !env_type_is_resolved(env, ret_type_id)) { | |
2925 | err = btf_resolve(env, ret_type, ret_type_id); | |
2926 | if (err) | |
2927 | return err; | |
2928 | } | |
2929 | ||
2930 | /* Ensure the return type is a type that has a size */ | |
2931 | if (!btf_type_id_size(btf, &ret_type_id, NULL)) { | |
2932 | btf_verifier_log_type(env, t, "Invalid return type"); | |
2933 | return -EINVAL; | |
2934 | } | |
2935 | } | |
2936 | ||
2937 | if (!nr_args) | |
2938 | return 0; | |
2939 | ||
2940 | /* Last func arg type_id could be 0 if it is a vararg */ | |
2941 | if (!args[nr_args - 1].type) { | |
2942 | if (args[nr_args - 1].name_off) { | |
2943 | btf_verifier_log_type(env, t, "Invalid arg#%u", | |
2944 | nr_args); | |
2945 | return -EINVAL; | |
2946 | } | |
2947 | nr_args--; | |
2948 | } | |
2949 | ||
2950 | err = 0; | |
2951 | for (i = 0; i < nr_args; i++) { | |
2952 | const struct btf_type *arg_type; | |
2953 | u32 arg_type_id; | |
2954 | ||
2955 | arg_type_id = args[i].type; | |
2956 | arg_type = btf_type_by_id(btf, arg_type_id); | |
2957 | if (!arg_type) { | |
2958 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
2959 | err = -EINVAL; | |
2960 | break; | |
2961 | } | |
2962 | ||
2963 | if (args[i].name_off && | |
2964 | (!btf_name_offset_valid(btf, args[i].name_off) || | |
2965 | !btf_name_valid_identifier(btf, args[i].name_off))) { | |
2966 | btf_verifier_log_type(env, t, | |
2967 | "Invalid arg#%u", i + 1); | |
2968 | err = -EINVAL; | |
2969 | break; | |
2970 | } | |
2971 | ||
2972 | if (btf_type_needs_resolve(arg_type) && | |
2973 | !env_type_is_resolved(env, arg_type_id)) { | |
2974 | err = btf_resolve(env, arg_type, arg_type_id); | |
2975 | if (err) | |
2976 | break; | |
2977 | } | |
2978 | ||
2979 | if (!btf_type_id_size(btf, &arg_type_id, NULL)) { | |
2980 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
2981 | err = -EINVAL; | |
2982 | break; | |
2983 | } | |
2984 | } | |
2985 | ||
2986 | return err; | |
2987 | } | |
2988 | ||
2989 | static int btf_func_check(struct btf_verifier_env *env, | |
2990 | const struct btf_type *t) | |
2991 | { | |
2992 | const struct btf_type *proto_type; | |
2993 | const struct btf_param *args; | |
2994 | const struct btf *btf; | |
2995 | u16 nr_args, i; | |
2996 | ||
2997 | btf = env->btf; | |
2998 | proto_type = btf_type_by_id(btf, t->type); | |
2999 | ||
3000 | if (!proto_type || !btf_type_is_func_proto(proto_type)) { | |
3001 | btf_verifier_log_type(env, t, "Invalid type_id"); | |
3002 | return -EINVAL; | |
3003 | } | |
3004 | ||
3005 | args = (const struct btf_param *)(proto_type + 1); | |
3006 | nr_args = btf_type_vlen(proto_type); | |
3007 | for (i = 0; i < nr_args; i++) { | |
3008 | if (!args[i].name_off && args[i].type) { | |
3009 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
3010 | return -EINVAL; | |
3011 | } | |
3012 | } | |
3013 | ||
3014 | return 0; | |
3015 | } | |
3016 | ||
69b693f0 MKL |
3017 | static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = { |
3018 | [BTF_KIND_INT] = &int_ops, | |
3019 | [BTF_KIND_PTR] = &ptr_ops, | |
3020 | [BTF_KIND_ARRAY] = &array_ops, | |
3021 | [BTF_KIND_STRUCT] = &struct_ops, | |
3022 | [BTF_KIND_UNION] = &struct_ops, | |
3023 | [BTF_KIND_ENUM] = &enum_ops, | |
3024 | [BTF_KIND_FWD] = &fwd_ops, | |
3025 | [BTF_KIND_TYPEDEF] = &modifier_ops, | |
3026 | [BTF_KIND_VOLATILE] = &modifier_ops, | |
3027 | [BTF_KIND_CONST] = &modifier_ops, | |
3028 | [BTF_KIND_RESTRICT] = &modifier_ops, | |
2667a262 MKL |
3029 | [BTF_KIND_FUNC] = &func_ops, |
3030 | [BTF_KIND_FUNC_PROTO] = &func_proto_ops, | |
1dc92851 DB |
3031 | [BTF_KIND_VAR] = &var_ops, |
3032 | [BTF_KIND_DATASEC] = &datasec_ops, | |
69b693f0 MKL |
3033 | }; |
3034 | ||
3035 | static s32 btf_check_meta(struct btf_verifier_env *env, | |
3036 | const struct btf_type *t, | |
3037 | u32 meta_left) | |
3038 | { | |
3039 | u32 saved_meta_left = meta_left; | |
3040 | s32 var_meta_size; | |
3041 | ||
3042 | if (meta_left < sizeof(*t)) { | |
3043 | btf_verifier_log(env, "[%u] meta_left:%u meta_needed:%zu", | |
3044 | env->log_type_id, meta_left, sizeof(*t)); | |
3045 | return -EINVAL; | |
3046 | } | |
3047 | meta_left -= sizeof(*t); | |
3048 | ||
aea2f7b8 MKL |
3049 | if (t->info & ~BTF_INFO_MASK) { |
3050 | btf_verifier_log(env, "[%u] Invalid btf_info:%x", | |
3051 | env->log_type_id, t->info); | |
3052 | return -EINVAL; | |
3053 | } | |
3054 | ||
69b693f0 MKL |
3055 | if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX || |
3056 | BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) { | |
3057 | btf_verifier_log(env, "[%u] Invalid kind:%u", | |
3058 | env->log_type_id, BTF_INFO_KIND(t->info)); | |
3059 | return -EINVAL; | |
3060 | } | |
3061 | ||
fbcf93eb | 3062 | if (!btf_name_offset_valid(env->btf, t->name_off)) { |
69b693f0 | 3063 | btf_verifier_log(env, "[%u] Invalid name_offset:%u", |
fbcf93eb | 3064 | env->log_type_id, t->name_off); |
69b693f0 MKL |
3065 | return -EINVAL; |
3066 | } | |
3067 | ||
3068 | var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left); | |
3069 | if (var_meta_size < 0) | |
3070 | return var_meta_size; | |
3071 | ||
3072 | meta_left -= var_meta_size; | |
3073 | ||
3074 | return saved_meta_left - meta_left; | |
3075 | } | |
3076 | ||
3077 | static int btf_check_all_metas(struct btf_verifier_env *env) | |
3078 | { | |
3079 | struct btf *btf = env->btf; | |
3080 | struct btf_header *hdr; | |
3081 | void *cur, *end; | |
3082 | ||
f80442a4 | 3083 | hdr = &btf->hdr; |
69b693f0 | 3084 | cur = btf->nohdr_data + hdr->type_off; |
4b1c5d91 | 3085 | end = cur + hdr->type_len; |
69b693f0 MKL |
3086 | |
3087 | env->log_type_id = 1; | |
3088 | while (cur < end) { | |
3089 | struct btf_type *t = cur; | |
3090 | s32 meta_size; | |
3091 | ||
3092 | meta_size = btf_check_meta(env, t, end - cur); | |
3093 | if (meta_size < 0) | |
3094 | return meta_size; | |
3095 | ||
3096 | btf_add_type(env, t); | |
3097 | cur += meta_size; | |
3098 | env->log_type_id++; | |
3099 | } | |
3100 | ||
3101 | return 0; | |
3102 | } | |
3103 | ||
eb3f595d MKL |
3104 | static bool btf_resolve_valid(struct btf_verifier_env *env, |
3105 | const struct btf_type *t, | |
3106 | u32 type_id) | |
3107 | { | |
3108 | struct btf *btf = env->btf; | |
3109 | ||
3110 | if (!env_type_is_resolved(env, type_id)) | |
3111 | return false; | |
3112 | ||
1dc92851 | 3113 | if (btf_type_is_struct(t) || btf_type_is_datasec(t)) |
eb3f595d | 3114 | return !btf->resolved_ids[type_id] && |
1dc92851 | 3115 | !btf->resolved_sizes[type_id]; |
eb3f595d | 3116 | |
1dc92851 DB |
3117 | if (btf_type_is_modifier(t) || btf_type_is_ptr(t) || |
3118 | btf_type_is_var(t)) { | |
eb3f595d | 3119 | t = btf_type_id_resolve(btf, &type_id); |
1dc92851 DB |
3120 | return t && |
3121 | !btf_type_is_modifier(t) && | |
3122 | !btf_type_is_var(t) && | |
3123 | !btf_type_is_datasec(t); | |
eb3f595d MKL |
3124 | } |
3125 | ||
3126 | if (btf_type_is_array(t)) { | |
3127 | const struct btf_array *array = btf_type_array(t); | |
3128 | const struct btf_type *elem_type; | |
3129 | u32 elem_type_id = array->type; | |
3130 | u32 elem_size; | |
3131 | ||
3132 | elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); | |
3133 | return elem_type && !btf_type_is_modifier(elem_type) && | |
3134 | (array->nelems * elem_size == | |
3135 | btf->resolved_sizes[type_id]); | |
3136 | } | |
3137 | ||
3138 | return false; | |
3139 | } | |
3140 | ||
2667a262 MKL |
3141 | static int btf_resolve(struct btf_verifier_env *env, |
3142 | const struct btf_type *t, u32 type_id) | |
3143 | { | |
3144 | u32 save_log_type_id = env->log_type_id; | |
3145 | const struct resolve_vertex *v; | |
3146 | int err = 0; | |
3147 | ||
3148 | env->resolve_mode = RESOLVE_TBD; | |
3149 | env_stack_push(env, t, type_id); | |
3150 | while (!err && (v = env_stack_peak(env))) { | |
3151 | env->log_type_id = v->type_id; | |
3152 | err = btf_type_ops(v->t)->resolve(env, v); | |
3153 | } | |
3154 | ||
3155 | env->log_type_id = type_id; | |
3156 | if (err == -E2BIG) { | |
3157 | btf_verifier_log_type(env, t, | |
3158 | "Exceeded max resolving depth:%u", | |
3159 | MAX_RESOLVE_DEPTH); | |
3160 | } else if (err == -EEXIST) { | |
3161 | btf_verifier_log_type(env, t, "Loop detected"); | |
3162 | } | |
3163 | ||
3164 | /* Final sanity check */ | |
3165 | if (!err && !btf_resolve_valid(env, t, type_id)) { | |
3166 | btf_verifier_log_type(env, t, "Invalid resolve state"); | |
3167 | err = -EINVAL; | |
3168 | } | |
3169 | ||
3170 | env->log_type_id = save_log_type_id; | |
3171 | return err; | |
3172 | } | |
3173 | ||
eb3f595d MKL |
3174 | static int btf_check_all_types(struct btf_verifier_env *env) |
3175 | { | |
3176 | struct btf *btf = env->btf; | |
3177 | u32 type_id; | |
3178 | int err; | |
3179 | ||
3180 | err = env_resolve_init(env); | |
3181 | if (err) | |
3182 | return err; | |
3183 | ||
3184 | env->phase++; | |
3185 | for (type_id = 1; type_id <= btf->nr_types; type_id++) { | |
3186 | const struct btf_type *t = btf_type_by_id(btf, type_id); | |
3187 | ||
3188 | env->log_type_id = type_id; | |
3189 | if (btf_type_needs_resolve(t) && | |
3190 | !env_type_is_resolved(env, type_id)) { | |
3191 | err = btf_resolve(env, t, type_id); | |
3192 | if (err) | |
3193 | return err; | |
3194 | } | |
3195 | ||
2667a262 MKL |
3196 | if (btf_type_is_func_proto(t)) { |
3197 | err = btf_func_proto_check(env, t); | |
3198 | if (err) | |
3199 | return err; | |
3200 | } | |
3201 | ||
3202 | if (btf_type_is_func(t)) { | |
3203 | err = btf_func_check(env, t); | |
3204 | if (err) | |
3205 | return err; | |
eb3f595d MKL |
3206 | } |
3207 | } | |
3208 | ||
3209 | return 0; | |
3210 | } | |
3211 | ||
69b693f0 MKL |
3212 | static int btf_parse_type_sec(struct btf_verifier_env *env) |
3213 | { | |
f80442a4 | 3214 | const struct btf_header *hdr = &env->btf->hdr; |
eb3f595d MKL |
3215 | int err; |
3216 | ||
f80442a4 MKL |
3217 | /* Type section must align to 4 bytes */ |
3218 | if (hdr->type_off & (sizeof(u32) - 1)) { | |
3219 | btf_verifier_log(env, "Unaligned type_off"); | |
3220 | return -EINVAL; | |
3221 | } | |
3222 | ||
3223 | if (!hdr->type_len) { | |
3224 | btf_verifier_log(env, "No type found"); | |
3225 | return -EINVAL; | |
3226 | } | |
3227 | ||
eb3f595d MKL |
3228 | err = btf_check_all_metas(env); |
3229 | if (err) | |
3230 | return err; | |
3231 | ||
3232 | return btf_check_all_types(env); | |
69b693f0 MKL |
3233 | } |
3234 | ||
3235 | static int btf_parse_str_sec(struct btf_verifier_env *env) | |
3236 | { | |
3237 | const struct btf_header *hdr; | |
3238 | struct btf *btf = env->btf; | |
3239 | const char *start, *end; | |
3240 | ||
f80442a4 | 3241 | hdr = &btf->hdr; |
69b693f0 MKL |
3242 | start = btf->nohdr_data + hdr->str_off; |
3243 | end = start + hdr->str_len; | |
3244 | ||
f80442a4 MKL |
3245 | if (end != btf->data + btf->data_size) { |
3246 | btf_verifier_log(env, "String section is not at the end"); | |
3247 | return -EINVAL; | |
3248 | } | |
3249 | ||
69b693f0 MKL |
3250 | if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET || |
3251 | start[0] || end[-1]) { | |
3252 | btf_verifier_log(env, "Invalid string section"); | |
3253 | return -EINVAL; | |
3254 | } | |
3255 | ||
3256 | btf->strings = start; | |
3257 | ||
3258 | return 0; | |
3259 | } | |
3260 | ||
f80442a4 MKL |
3261 | static const size_t btf_sec_info_offset[] = { |
3262 | offsetof(struct btf_header, type_off), | |
3263 | offsetof(struct btf_header, str_off), | |
3264 | }; | |
3265 | ||
3266 | static int btf_sec_info_cmp(const void *a, const void *b) | |
69b693f0 | 3267 | { |
f80442a4 MKL |
3268 | const struct btf_sec_info *x = a; |
3269 | const struct btf_sec_info *y = b; | |
3270 | ||
3271 | return (int)(x->off - y->off) ? : (int)(x->len - y->len); | |
3272 | } | |
3273 | ||
3274 | static int btf_check_sec_info(struct btf_verifier_env *env, | |
3275 | u32 btf_data_size) | |
3276 | { | |
a2889a4c | 3277 | struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)]; |
f80442a4 | 3278 | u32 total, expected_total, i; |
69b693f0 | 3279 | const struct btf_header *hdr; |
f80442a4 MKL |
3280 | const struct btf *btf; |
3281 | ||
3282 | btf = env->btf; | |
3283 | hdr = &btf->hdr; | |
3284 | ||
3285 | /* Populate the secs from hdr */ | |
a2889a4c | 3286 | for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) |
f80442a4 MKL |
3287 | secs[i] = *(struct btf_sec_info *)((void *)hdr + |
3288 | btf_sec_info_offset[i]); | |
3289 | ||
a2889a4c MKL |
3290 | sort(secs, ARRAY_SIZE(btf_sec_info_offset), |
3291 | sizeof(struct btf_sec_info), btf_sec_info_cmp, NULL); | |
f80442a4 MKL |
3292 | |
3293 | /* Check for gaps and overlap among sections */ | |
3294 | total = 0; | |
3295 | expected_total = btf_data_size - hdr->hdr_len; | |
a2889a4c | 3296 | for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) { |
f80442a4 MKL |
3297 | if (expected_total < secs[i].off) { |
3298 | btf_verifier_log(env, "Invalid section offset"); | |
3299 | return -EINVAL; | |
3300 | } | |
3301 | if (total < secs[i].off) { | |
3302 | /* gap */ | |
3303 | btf_verifier_log(env, "Unsupported section found"); | |
3304 | return -EINVAL; | |
3305 | } | |
3306 | if (total > secs[i].off) { | |
3307 | btf_verifier_log(env, "Section overlap found"); | |
3308 | return -EINVAL; | |
3309 | } | |
3310 | if (expected_total - total < secs[i].len) { | |
3311 | btf_verifier_log(env, | |
3312 | "Total section length too long"); | |
3313 | return -EINVAL; | |
3314 | } | |
3315 | total += secs[i].len; | |
3316 | } | |
3317 | ||
3318 | /* There is data other than hdr and known sections */ | |
3319 | if (expected_total != total) { | |
3320 | btf_verifier_log(env, "Unsupported section found"); | |
3321 | return -EINVAL; | |
3322 | } | |
3323 | ||
3324 | return 0; | |
3325 | } | |
3326 | ||
4a6998af | 3327 | static int btf_parse_hdr(struct btf_verifier_env *env) |
f80442a4 | 3328 | { |
4a6998af | 3329 | u32 hdr_len, hdr_copy, btf_data_size; |
f80442a4 | 3330 | const struct btf_header *hdr; |
f80442a4 MKL |
3331 | struct btf *btf; |
3332 | int err; | |
69b693f0 | 3333 | |
f80442a4 | 3334 | btf = env->btf; |
4a6998af | 3335 | btf_data_size = btf->data_size; |
f80442a4 | 3336 | |
4a6998af ML |
3337 | if (btf_data_size < |
3338 | offsetof(struct btf_header, hdr_len) + sizeof(hdr->hdr_len)) { | |
f80442a4 MKL |
3339 | btf_verifier_log(env, "hdr_len not found"); |
3340 | return -EINVAL; | |
3341 | } | |
3342 | ||
4a6998af ML |
3343 | hdr = btf->data; |
3344 | hdr_len = hdr->hdr_len; | |
f80442a4 | 3345 | if (btf_data_size < hdr_len) { |
69b693f0 MKL |
3346 | btf_verifier_log(env, "btf_header not found"); |
3347 | return -EINVAL; | |
3348 | } | |
3349 | ||
4a6998af ML |
3350 | /* Ensure the unsupported header fields are zero */ |
3351 | if (hdr_len > sizeof(btf->hdr)) { | |
3352 | u8 *expected_zero = btf->data + sizeof(btf->hdr); | |
3353 | u8 *end = btf->data + hdr_len; | |
3354 | ||
3355 | for (; expected_zero < end; expected_zero++) { | |
3356 | if (*expected_zero) { | |
3357 | btf_verifier_log(env, "Unsupported btf_header"); | |
3358 | return -E2BIG; | |
3359 | } | |
3360 | } | |
f80442a4 MKL |
3361 | } |
3362 | ||
3363 | hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr)); | |
4a6998af | 3364 | memcpy(&btf->hdr, btf->data, hdr_copy); |
f80442a4 MKL |
3365 | |
3366 | hdr = &btf->hdr; | |
3367 | ||
3368 | btf_verifier_log_hdr(env, btf_data_size); | |
69b693f0 | 3369 | |
69b693f0 MKL |
3370 | if (hdr->magic != BTF_MAGIC) { |
3371 | btf_verifier_log(env, "Invalid magic"); | |
3372 | return -EINVAL; | |
3373 | } | |
3374 | ||
3375 | if (hdr->version != BTF_VERSION) { | |
3376 | btf_verifier_log(env, "Unsupported version"); | |
3377 | return -ENOTSUPP; | |
3378 | } | |
3379 | ||
3380 | if (hdr->flags) { | |
3381 | btf_verifier_log(env, "Unsupported flags"); | |
3382 | return -ENOTSUPP; | |
3383 | } | |
3384 | ||
f80442a4 | 3385 | if (btf_data_size == hdr->hdr_len) { |
69b693f0 MKL |
3386 | btf_verifier_log(env, "No data"); |
3387 | return -EINVAL; | |
3388 | } | |
3389 | ||
f80442a4 MKL |
3390 | err = btf_check_sec_info(env, btf_data_size); |
3391 | if (err) | |
3392 | return err; | |
69b693f0 MKL |
3393 | |
3394 | return 0; | |
3395 | } | |
3396 | ||
3397 | static struct btf *btf_parse(void __user *btf_data, u32 btf_data_size, | |
3398 | u32 log_level, char __user *log_ubuf, u32 log_size) | |
3399 | { | |
3400 | struct btf_verifier_env *env = NULL; | |
3401 | struct bpf_verifier_log *log; | |
3402 | struct btf *btf = NULL; | |
3403 | u8 *data; | |
3404 | int err; | |
3405 | ||
3406 | if (btf_data_size > BTF_MAX_SIZE) | |
3407 | return ERR_PTR(-E2BIG); | |
3408 | ||
3409 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
3410 | if (!env) | |
3411 | return ERR_PTR(-ENOMEM); | |
3412 | ||
3413 | log = &env->log; | |
3414 | if (log_level || log_ubuf || log_size) { | |
3415 | /* user requested verbose verifier output | |
3416 | * and supplied buffer to store the verification trace | |
3417 | */ | |
3418 | log->level = log_level; | |
3419 | log->ubuf = log_ubuf; | |
3420 | log->len_total = log_size; | |
3421 | ||
3422 | /* log attributes have to be sane */ | |
3423 | if (log->len_total < 128 || log->len_total > UINT_MAX >> 8 || | |
3424 | !log->level || !log->ubuf) { | |
3425 | err = -EINVAL; | |
3426 | goto errout; | |
3427 | } | |
3428 | } | |
3429 | ||
3430 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
3431 | if (!btf) { | |
3432 | err = -ENOMEM; | |
3433 | goto errout; | |
3434 | } | |
f80442a4 MKL |
3435 | env->btf = btf; |
3436 | ||
69b693f0 MKL |
3437 | data = kvmalloc(btf_data_size, GFP_KERNEL | __GFP_NOWARN); |
3438 | if (!data) { | |
3439 | err = -ENOMEM; | |
3440 | goto errout; | |
3441 | } | |
3442 | ||
3443 | btf->data = data; | |
3444 | btf->data_size = btf_data_size; | |
3445 | ||
3446 | if (copy_from_user(data, btf_data, btf_data_size)) { | |
3447 | err = -EFAULT; | |
3448 | goto errout; | |
3449 | } | |
3450 | ||
4a6998af ML |
3451 | err = btf_parse_hdr(env); |
3452 | if (err) | |
3453 | goto errout; | |
3454 | ||
3455 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
3456 | ||
69b693f0 MKL |
3457 | err = btf_parse_str_sec(env); |
3458 | if (err) | |
3459 | goto errout; | |
3460 | ||
3461 | err = btf_parse_type_sec(env); | |
3462 | if (err) | |
3463 | goto errout; | |
3464 | ||
f80442a4 | 3465 | if (log->level && bpf_verifier_log_full(log)) { |
69b693f0 MKL |
3466 | err = -ENOSPC; |
3467 | goto errout; | |
3468 | } | |
3469 | ||
f80442a4 MKL |
3470 | btf_verifier_env_free(env); |
3471 | refcount_set(&btf->refcnt, 1); | |
3472 | return btf; | |
69b693f0 MKL |
3473 | |
3474 | errout: | |
3475 | btf_verifier_env_free(env); | |
3476 | if (btf) | |
3477 | btf_free(btf); | |
3478 | return ERR_PTR(err); | |
3479 | } | |
b00b8dae | 3480 | |
90ceddcb FS |
3481 | extern char __weak __start_BTF[]; |
3482 | extern char __weak __stop_BTF[]; | |
91cc1a99 AS |
3483 | extern struct btf *btf_vmlinux; |
3484 | ||
3485 | #define BPF_MAP_TYPE(_id, _ops) | |
f2e10bff | 3486 | #define BPF_LINK_TYPE(_id, _name) |
91cc1a99 AS |
3487 | static union { |
3488 | struct bpf_ctx_convert { | |
3489 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
3490 | prog_ctx_type _id##_prog; \ | |
3491 | kern_ctx_type _id##_kern; | |
3492 | #include <linux/bpf_types.h> | |
3493 | #undef BPF_PROG_TYPE | |
3494 | } *__t; | |
3495 | /* 't' is written once under lock. Read many times. */ | |
3496 | const struct btf_type *t; | |
3497 | } bpf_ctx_convert; | |
3498 | enum { | |
3499 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
3500 | __ctx_convert##_id, | |
3501 | #include <linux/bpf_types.h> | |
3502 | #undef BPF_PROG_TYPE | |
ce27709b | 3503 | __ctx_convert_unused, /* to avoid empty enum in extreme .config */ |
91cc1a99 AS |
3504 | }; |
3505 | static u8 bpf_ctx_convert_map[] = { | |
3506 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
3507 | [_id] = __ctx_convert##_id, | |
3508 | #include <linux/bpf_types.h> | |
3509 | #undef BPF_PROG_TYPE | |
4c80c7bc | 3510 | 0, /* avoid empty array */ |
91cc1a99 AS |
3511 | }; |
3512 | #undef BPF_MAP_TYPE | |
f2e10bff | 3513 | #undef BPF_LINK_TYPE |
91cc1a99 AS |
3514 | |
3515 | static const struct btf_member * | |
3516 | btf_get_prog_ctx_type(struct bpf_verifier_log *log, struct btf *btf, | |
51c39bb1 AS |
3517 | const struct btf_type *t, enum bpf_prog_type prog_type, |
3518 | int arg) | |
91cc1a99 AS |
3519 | { |
3520 | const struct btf_type *conv_struct; | |
3521 | const struct btf_type *ctx_struct; | |
3522 | const struct btf_member *ctx_type; | |
3523 | const char *tname, *ctx_tname; | |
3524 | ||
3525 | conv_struct = bpf_ctx_convert.t; | |
3526 | if (!conv_struct) { | |
3527 | bpf_log(log, "btf_vmlinux is malformed\n"); | |
3528 | return NULL; | |
3529 | } | |
3530 | t = btf_type_by_id(btf, t->type); | |
3531 | while (btf_type_is_modifier(t)) | |
3532 | t = btf_type_by_id(btf, t->type); | |
3533 | if (!btf_type_is_struct(t)) { | |
3534 | /* Only pointer to struct is supported for now. | |
3535 | * That means that BPF_PROG_TYPE_TRACEPOINT with BTF | |
3536 | * is not supported yet. | |
3537 | * BPF_PROG_TYPE_RAW_TRACEPOINT is fine. | |
3538 | */ | |
51c39bb1 AS |
3539 | if (log->level & BPF_LOG_LEVEL) |
3540 | bpf_log(log, "arg#%d type is not a struct\n", arg); | |
91cc1a99 AS |
3541 | return NULL; |
3542 | } | |
3543 | tname = btf_name_by_offset(btf, t->name_off); | |
3544 | if (!tname) { | |
51c39bb1 | 3545 | bpf_log(log, "arg#%d struct doesn't have a name\n", arg); |
91cc1a99 AS |
3546 | return NULL; |
3547 | } | |
3548 | /* prog_type is valid bpf program type. No need for bounds check. */ | |
3549 | ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2; | |
3550 | /* ctx_struct is a pointer to prog_ctx_type in vmlinux. | |
3551 | * Like 'struct __sk_buff' | |
3552 | */ | |
3553 | ctx_struct = btf_type_by_id(btf_vmlinux, ctx_type->type); | |
3554 | if (!ctx_struct) | |
3555 | /* should not happen */ | |
3556 | return NULL; | |
3557 | ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_struct->name_off); | |
3558 | if (!ctx_tname) { | |
3559 | /* should not happen */ | |
3560 | bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n"); | |
3561 | return NULL; | |
3562 | } | |
3563 | /* only compare that prog's ctx type name is the same as | |
3564 | * kernel expects. No need to compare field by field. | |
3565 | * It's ok for bpf prog to do: | |
3566 | * struct __sk_buff {}; | |
3567 | * int socket_filter_bpf_prog(struct __sk_buff *skb) | |
3568 | * { // no fields of skb are ever used } | |
3569 | */ | |
3570 | if (strcmp(ctx_tname, tname)) | |
3571 | return NULL; | |
3572 | return ctx_type; | |
3573 | } | |
8580ac94 | 3574 | |
41c48f3a AI |
3575 | static const struct bpf_map_ops * const btf_vmlinux_map_ops[] = { |
3576 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) | |
3577 | #define BPF_LINK_TYPE(_id, _name) | |
3578 | #define BPF_MAP_TYPE(_id, _ops) \ | |
3579 | [_id] = &_ops, | |
3580 | #include <linux/bpf_types.h> | |
3581 | #undef BPF_PROG_TYPE | |
3582 | #undef BPF_LINK_TYPE | |
3583 | #undef BPF_MAP_TYPE | |
3584 | }; | |
3585 | ||
3586 | static int btf_vmlinux_map_ids_init(const struct btf *btf, | |
3587 | struct bpf_verifier_log *log) | |
3588 | { | |
3589 | const struct bpf_map_ops *ops; | |
3590 | int i, btf_id; | |
3591 | ||
3592 | for (i = 0; i < ARRAY_SIZE(btf_vmlinux_map_ops); ++i) { | |
3593 | ops = btf_vmlinux_map_ops[i]; | |
3594 | if (!ops || (!ops->map_btf_name && !ops->map_btf_id)) | |
3595 | continue; | |
3596 | if (!ops->map_btf_name || !ops->map_btf_id) { | |
3597 | bpf_log(log, "map type %d is misconfigured\n", i); | |
3598 | return -EINVAL; | |
3599 | } | |
3600 | btf_id = btf_find_by_name_kind(btf, ops->map_btf_name, | |
3601 | BTF_KIND_STRUCT); | |
3602 | if (btf_id < 0) | |
3603 | return btf_id; | |
3604 | *ops->map_btf_id = btf_id; | |
3605 | } | |
3606 | ||
3607 | return 0; | |
3608 | } | |
3609 | ||
5b92a28a AS |
3610 | static int btf_translate_to_vmlinux(struct bpf_verifier_log *log, |
3611 | struct btf *btf, | |
3612 | const struct btf_type *t, | |
51c39bb1 AS |
3613 | enum bpf_prog_type prog_type, |
3614 | int arg) | |
5b92a28a AS |
3615 | { |
3616 | const struct btf_member *prog_ctx_type, *kern_ctx_type; | |
3617 | ||
51c39bb1 | 3618 | prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type, arg); |
5b92a28a AS |
3619 | if (!prog_ctx_type) |
3620 | return -ENOENT; | |
3621 | kern_ctx_type = prog_ctx_type + 1; | |
3622 | return kern_ctx_type->type; | |
3623 | } | |
3624 | ||
49f4e672 JO |
3625 | BTF_ID_LIST(bpf_ctx_convert_btf_id) |
3626 | BTF_ID(struct, bpf_ctx_convert) | |
3627 | ||
8580ac94 AS |
3628 | struct btf *btf_parse_vmlinux(void) |
3629 | { | |
3630 | struct btf_verifier_env *env = NULL; | |
3631 | struct bpf_verifier_log *log; | |
3632 | struct btf *btf = NULL; | |
49f4e672 | 3633 | int err; |
8580ac94 AS |
3634 | |
3635 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
3636 | if (!env) | |
3637 | return ERR_PTR(-ENOMEM); | |
3638 | ||
3639 | log = &env->log; | |
3640 | log->level = BPF_LOG_KERNEL; | |
3641 | ||
3642 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
3643 | if (!btf) { | |
3644 | err = -ENOMEM; | |
3645 | goto errout; | |
3646 | } | |
3647 | env->btf = btf; | |
3648 | ||
90ceddcb FS |
3649 | btf->data = __start_BTF; |
3650 | btf->data_size = __stop_BTF - __start_BTF; | |
8580ac94 AS |
3651 | |
3652 | err = btf_parse_hdr(env); | |
3653 | if (err) | |
3654 | goto errout; | |
3655 | ||
3656 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
3657 | ||
3658 | err = btf_parse_str_sec(env); | |
3659 | if (err) | |
3660 | goto errout; | |
3661 | ||
3662 | err = btf_check_all_metas(env); | |
3663 | if (err) | |
3664 | goto errout; | |
3665 | ||
a2d0d62f | 3666 | /* btf_parse_vmlinux() runs under bpf_verifier_lock */ |
49f4e672 | 3667 | bpf_ctx_convert.t = btf_type_by_id(btf, bpf_ctx_convert_btf_id[0]); |
91cc1a99 | 3668 | |
41c48f3a AI |
3669 | /* find bpf map structs for map_ptr access checking */ |
3670 | err = btf_vmlinux_map_ids_init(btf, log); | |
3671 | if (err < 0) | |
3672 | goto errout; | |
3673 | ||
d3e42bb0 | 3674 | bpf_struct_ops_init(btf, log); |
27ae7997 | 3675 | |
8580ac94 AS |
3676 | btf_verifier_env_free(env); |
3677 | refcount_set(&btf->refcnt, 1); | |
3678 | return btf; | |
3679 | ||
3680 | errout: | |
3681 | btf_verifier_env_free(env); | |
3682 | if (btf) { | |
3683 | kvfree(btf->types); | |
3684 | kfree(btf); | |
3685 | } | |
3686 | return ERR_PTR(err); | |
3687 | } | |
3688 | ||
5b92a28a AS |
3689 | struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog) |
3690 | { | |
3691 | struct bpf_prog *tgt_prog = prog->aux->linked_prog; | |
3692 | ||
3693 | if (tgt_prog) { | |
3694 | return tgt_prog->aux->btf; | |
3695 | } else { | |
3696 | return btf_vmlinux; | |
3697 | } | |
3698 | } | |
3699 | ||
84ad7a7a JO |
3700 | static bool is_string_ptr(struct btf *btf, const struct btf_type *t) |
3701 | { | |
3702 | /* t comes in already as a pointer */ | |
3703 | t = btf_type_by_id(btf, t->type); | |
3704 | ||
3705 | /* allow const */ | |
3706 | if (BTF_INFO_KIND(t->info) == BTF_KIND_CONST) | |
3707 | t = btf_type_by_id(btf, t->type); | |
3708 | ||
3709 | /* char, signed char, unsigned char */ | |
3710 | return btf_type_is_int(t) && t->size == 1; | |
3711 | } | |
3712 | ||
9e15db66 AS |
3713 | bool btf_ctx_access(int off, int size, enum bpf_access_type type, |
3714 | const struct bpf_prog *prog, | |
3715 | struct bpf_insn_access_aux *info) | |
3716 | { | |
38207291 | 3717 | const struct btf_type *t = prog->aux->attach_func_proto; |
5b92a28a AS |
3718 | struct bpf_prog *tgt_prog = prog->aux->linked_prog; |
3719 | struct btf *btf = bpf_prog_get_target_btf(prog); | |
38207291 | 3720 | const char *tname = prog->aux->attach_func_name; |
9e15db66 | 3721 | struct bpf_verifier_log *log = info->log; |
9e15db66 | 3722 | const struct btf_param *args; |
9e15db66 | 3723 | u32 nr_args, arg; |
3c32cc1b | 3724 | int i, ret; |
9e15db66 | 3725 | |
9e15db66 | 3726 | if (off % 8) { |
38207291 | 3727 | bpf_log(log, "func '%s' offset %d is not multiple of 8\n", |
9e15db66 AS |
3728 | tname, off); |
3729 | return false; | |
3730 | } | |
3731 | arg = off / 8; | |
3732 | args = (const struct btf_param *)(t + 1); | |
5b92a28a AS |
3733 | /* if (t == NULL) Fall back to default BPF prog with 5 u64 arguments */ |
3734 | nr_args = t ? btf_type_vlen(t) : 5; | |
38207291 MKL |
3735 | if (prog->aux->attach_btf_trace) { |
3736 | /* skip first 'void *__data' argument in btf_trace_##name typedef */ | |
3737 | args++; | |
3738 | nr_args--; | |
3739 | } | |
fec56f58 | 3740 | |
f50b49a0 KS |
3741 | if (arg > nr_args) { |
3742 | bpf_log(log, "func '%s' doesn't have %d-th argument\n", | |
3743 | tname, arg + 1); | |
3744 | return false; | |
3745 | } | |
3746 | ||
6ba43b76 | 3747 | if (arg == nr_args) { |
f50b49a0 KS |
3748 | switch (prog->expected_attach_type) { |
3749 | case BPF_LSM_MAC: | |
3750 | case BPF_TRACE_FEXIT: | |
9e4e01df KS |
3751 | /* When LSM programs are attached to void LSM hooks |
3752 | * they use FEXIT trampolines and when attached to | |
3753 | * int LSM hooks, they use MODIFY_RETURN trampolines. | |
3754 | * | |
3755 | * While the LSM programs are BPF_MODIFY_RETURN-like | |
3756 | * the check: | |
3757 | * | |
3758 | * if (ret_type != 'int') | |
3759 | * return -EINVAL; | |
3760 | * | |
3761 | * is _not_ done here. This is still safe as LSM hooks | |
3762 | * have only void and int return types. | |
3763 | */ | |
6ba43b76 KS |
3764 | if (!t) |
3765 | return true; | |
3766 | t = btf_type_by_id(btf, t->type); | |
f50b49a0 KS |
3767 | break; |
3768 | case BPF_MODIFY_RETURN: | |
6ba43b76 KS |
3769 | /* For now the BPF_MODIFY_RETURN can only be attached to |
3770 | * functions that return an int. | |
3771 | */ | |
3772 | if (!t) | |
3773 | return false; | |
3774 | ||
3775 | t = btf_type_skip_modifiers(btf, t->type, NULL); | |
a9b59159 | 3776 | if (!btf_type_is_small_int(t)) { |
6ba43b76 KS |
3777 | bpf_log(log, |
3778 | "ret type %s not allowed for fmod_ret\n", | |
3779 | btf_kind_str[BTF_INFO_KIND(t->info)]); | |
3780 | return false; | |
3781 | } | |
f50b49a0 KS |
3782 | break; |
3783 | default: | |
3784 | bpf_log(log, "func '%s' doesn't have %d-th argument\n", | |
3785 | tname, arg + 1); | |
3786 | return false; | |
6ba43b76 | 3787 | } |
fec56f58 | 3788 | } else { |
5b92a28a AS |
3789 | if (!t) |
3790 | /* Default prog with 5 args */ | |
3791 | return true; | |
3792 | t = btf_type_by_id(btf, args[arg].type); | |
9e15db66 | 3793 | } |
f50b49a0 | 3794 | |
9e15db66 AS |
3795 | /* skip modifiers */ |
3796 | while (btf_type_is_modifier(t)) | |
5b92a28a | 3797 | t = btf_type_by_id(btf, t->type); |
a9b59159 | 3798 | if (btf_type_is_small_int(t) || btf_type_is_enum(t)) |
9e15db66 AS |
3799 | /* accessing a scalar */ |
3800 | return true; | |
3801 | if (!btf_type_is_ptr(t)) { | |
3802 | bpf_log(log, | |
38207291 | 3803 | "func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n", |
9e15db66 | 3804 | tname, arg, |
5b92a28a | 3805 | __btf_name_by_offset(btf, t->name_off), |
9e15db66 AS |
3806 | btf_kind_str[BTF_INFO_KIND(t->info)]); |
3807 | return false; | |
3808 | } | |
afbf21dc YS |
3809 | |
3810 | /* check for PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL */ | |
3811 | for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { | |
3812 | const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; | |
3813 | ||
3814 | if (ctx_arg_info->offset == off && | |
3815 | (ctx_arg_info->reg_type == PTR_TO_RDONLY_BUF_OR_NULL || | |
3816 | ctx_arg_info->reg_type == PTR_TO_RDWR_BUF_OR_NULL)) { | |
3817 | info->reg_type = ctx_arg_info->reg_type; | |
3818 | return true; | |
3819 | } | |
3820 | } | |
3821 | ||
9e15db66 AS |
3822 | if (t->type == 0) |
3823 | /* This is a pointer to void. | |
3824 | * It is the same as scalar from the verifier safety pov. | |
3825 | * No further pointer walking is allowed. | |
3826 | */ | |
3827 | return true; | |
3828 | ||
84ad7a7a JO |
3829 | if (is_string_ptr(btf, t)) |
3830 | return true; | |
3831 | ||
9e15db66 | 3832 | /* this is a pointer to another type */ |
3c32cc1b YS |
3833 | for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { |
3834 | const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; | |
3835 | ||
3836 | if (ctx_arg_info->offset == off) { | |
3837 | info->reg_type = ctx_arg_info->reg_type; | |
951cf368 YS |
3838 | info->btf_id = ctx_arg_info->btf_id; |
3839 | return true; | |
3c32cc1b YS |
3840 | } |
3841 | } | |
9e15db66 | 3842 | |
951cf368 | 3843 | info->reg_type = PTR_TO_BTF_ID; |
5b92a28a | 3844 | if (tgt_prog) { |
51c39bb1 | 3845 | ret = btf_translate_to_vmlinux(log, btf, t, tgt_prog->type, arg); |
5b92a28a AS |
3846 | if (ret > 0) { |
3847 | info->btf_id = ret; | |
3848 | return true; | |
3849 | } else { | |
3850 | return false; | |
3851 | } | |
3852 | } | |
275517ff MKL |
3853 | |
3854 | info->btf_id = t->type; | |
5b92a28a | 3855 | t = btf_type_by_id(btf, t->type); |
9e15db66 | 3856 | /* skip modifiers */ |
275517ff MKL |
3857 | while (btf_type_is_modifier(t)) { |
3858 | info->btf_id = t->type; | |
5b92a28a | 3859 | t = btf_type_by_id(btf, t->type); |
275517ff | 3860 | } |
9e15db66 AS |
3861 | if (!btf_type_is_struct(t)) { |
3862 | bpf_log(log, | |
38207291 | 3863 | "func '%s' arg%d type %s is not a struct\n", |
9e15db66 AS |
3864 | tname, arg, btf_kind_str[BTF_INFO_KIND(t->info)]); |
3865 | return false; | |
3866 | } | |
38207291 | 3867 | bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n", |
9e15db66 | 3868 | tname, arg, info->btf_id, btf_kind_str[BTF_INFO_KIND(t->info)], |
5b92a28a | 3869 | __btf_name_by_offset(btf, t->name_off)); |
9e15db66 AS |
3870 | return true; |
3871 | } | |
3872 | ||
3873 | int btf_struct_access(struct bpf_verifier_log *log, | |
3874 | const struct btf_type *t, int off, int size, | |
3875 | enum bpf_access_type atype, | |
3876 | u32 *next_btf_id) | |
3877 | { | |
7e3617a7 MKL |
3878 | u32 i, moff, mtrue_end, msize = 0, total_nelems = 0; |
3879 | const struct btf_type *mtype, *elem_type = NULL; | |
9e15db66 | 3880 | const struct btf_member *member; |
9e15db66 | 3881 | const char *tname, *mname; |
9c5f8a10 | 3882 | u32 vlen; |
9e15db66 AS |
3883 | |
3884 | again: | |
3885 | tname = __btf_name_by_offset(btf_vmlinux, t->name_off); | |
3886 | if (!btf_type_is_struct(t)) { | |
275517ff | 3887 | bpf_log(log, "Type '%s' is not a struct\n", tname); |
9e15db66 AS |
3888 | return -EINVAL; |
3889 | } | |
3890 | ||
9c5f8a10 | 3891 | vlen = btf_type_vlen(t); |
976aba00 | 3892 | if (off + size > t->size) { |
9c5f8a10 YS |
3893 | /* If the last element is a variable size array, we may |
3894 | * need to relax the rule. | |
3895 | */ | |
3896 | struct btf_array *array_elem; | |
3897 | ||
3898 | if (vlen == 0) | |
3899 | goto error; | |
3900 | ||
3901 | member = btf_type_member(t) + vlen - 1; | |
3902 | mtype = btf_type_skip_modifiers(btf_vmlinux, member->type, | |
3903 | NULL); | |
3904 | if (!btf_type_is_array(mtype)) | |
3905 | goto error; | |
3906 | ||
3907 | array_elem = (struct btf_array *)(mtype + 1); | |
3908 | if (array_elem->nelems != 0) | |
3909 | goto error; | |
3910 | ||
3911 | moff = btf_member_bit_offset(t, member) / 8; | |
3912 | if (off < moff) | |
3913 | goto error; | |
3914 | ||
3915 | /* Only allow structure for now, can be relaxed for | |
3916 | * other types later. | |
3917 | */ | |
3918 | elem_type = btf_type_skip_modifiers(btf_vmlinux, | |
3919 | array_elem->type, NULL); | |
3920 | if (!btf_type_is_struct(elem_type)) | |
3921 | goto error; | |
3922 | ||
3923 | off = (off - moff) % elem_type->size; | |
3924 | return btf_struct_access(log, elem_type, off, size, atype, | |
3925 | next_btf_id); | |
3926 | ||
3927 | error: | |
976aba00 MKL |
3928 | bpf_log(log, "access beyond struct %s at off %u size %u\n", |
3929 | tname, off, size); | |
3930 | return -EACCES; | |
3931 | } | |
9e15db66 | 3932 | |
976aba00 | 3933 | for_each_member(i, t, member) { |
7e3617a7 MKL |
3934 | /* offset of the field in bytes */ |
3935 | moff = btf_member_bit_offset(t, member) / 8; | |
3936 | if (off + size <= moff) | |
9e15db66 AS |
3937 | /* won't find anything, field is already too far */ |
3938 | break; | |
976aba00 MKL |
3939 | |
3940 | if (btf_member_bitfield_size(t, member)) { | |
3941 | u32 end_bit = btf_member_bit_offset(t, member) + | |
3942 | btf_member_bitfield_size(t, member); | |
3943 | ||
3944 | /* off <= moff instead of off == moff because clang | |
3945 | * does not generate a BTF member for anonymous | |
3946 | * bitfield like the ":16" here: | |
3947 | * struct { | |
3948 | * int :16; | |
3949 | * int x:8; | |
3950 | * }; | |
3951 | */ | |
3952 | if (off <= moff && | |
3953 | BITS_ROUNDUP_BYTES(end_bit) <= off + size) | |
3954 | return SCALAR_VALUE; | |
3955 | ||
3956 | /* off may be accessing a following member | |
3957 | * | |
3958 | * or | |
3959 | * | |
3960 | * Doing partial access at either end of this | |
3961 | * bitfield. Continue on this case also to | |
3962 | * treat it as not accessing this bitfield | |
3963 | * and eventually error out as field not | |
3964 | * found to keep it simple. | |
3965 | * It could be relaxed if there was a legit | |
3966 | * partial access case later. | |
3967 | */ | |
3968 | continue; | |
3969 | } | |
3970 | ||
7e3617a7 MKL |
3971 | /* In case of "off" is pointing to holes of a struct */ |
3972 | if (off < moff) | |
976aba00 | 3973 | break; |
9e15db66 AS |
3974 | |
3975 | /* type of the field */ | |
3976 | mtype = btf_type_by_id(btf_vmlinux, member->type); | |
3977 | mname = __btf_name_by_offset(btf_vmlinux, member->name_off); | |
3978 | ||
7e3617a7 MKL |
3979 | mtype = btf_resolve_size(btf_vmlinux, mtype, &msize, |
3980 | &elem_type, &total_nelems); | |
3981 | if (IS_ERR(mtype)) { | |
9e15db66 AS |
3982 | bpf_log(log, "field %s doesn't have size\n", mname); |
3983 | return -EFAULT; | |
3984 | } | |
7e3617a7 MKL |
3985 | |
3986 | mtrue_end = moff + msize; | |
3987 | if (off >= mtrue_end) | |
9e15db66 AS |
3988 | /* no overlap with member, keep iterating */ |
3989 | continue; | |
7e3617a7 MKL |
3990 | |
3991 | if (btf_type_is_array(mtype)) { | |
3992 | u32 elem_idx; | |
3993 | ||
3994 | /* btf_resolve_size() above helps to | |
3995 | * linearize a multi-dimensional array. | |
3996 | * | |
3997 | * The logic here is treating an array | |
3998 | * in a struct as the following way: | |
3999 | * | |
4000 | * struct outer { | |
4001 | * struct inner array[2][2]; | |
4002 | * }; | |
4003 | * | |
4004 | * looks like: | |
4005 | * | |
4006 | * struct outer { | |
4007 | * struct inner array_elem0; | |
4008 | * struct inner array_elem1; | |
4009 | * struct inner array_elem2; | |
4010 | * struct inner array_elem3; | |
4011 | * }; | |
4012 | * | |
4013 | * When accessing outer->array[1][0], it moves | |
4014 | * moff to "array_elem2", set mtype to | |
4015 | * "struct inner", and msize also becomes | |
4016 | * sizeof(struct inner). Then most of the | |
4017 | * remaining logic will fall through without | |
4018 | * caring the current member is an array or | |
4019 | * not. | |
4020 | * | |
4021 | * Unlike mtype/msize/moff, mtrue_end does not | |
4022 | * change. The naming difference ("_true") tells | |
4023 | * that it is not always corresponding to | |
4024 | * the current mtype/msize/moff. | |
4025 | * It is the true end of the current | |
4026 | * member (i.e. array in this case). That | |
4027 | * will allow an int array to be accessed like | |
4028 | * a scratch space, | |
4029 | * i.e. allow access beyond the size of | |
4030 | * the array's element as long as it is | |
4031 | * within the mtrue_end boundary. | |
4032 | */ | |
4033 | ||
4034 | /* skip empty array */ | |
4035 | if (moff == mtrue_end) | |
4036 | continue; | |
4037 | ||
4038 | msize /= total_nelems; | |
4039 | elem_idx = (off - moff) / msize; | |
4040 | moff += elem_idx * msize; | |
4041 | mtype = elem_type; | |
4042 | } | |
4043 | ||
9e15db66 AS |
4044 | /* the 'off' we're looking for is either equal to start |
4045 | * of this field or inside of this struct | |
4046 | */ | |
4047 | if (btf_type_is_struct(mtype)) { | |
4048 | /* our field must be inside that union or struct */ | |
4049 | t = mtype; | |
4050 | ||
4051 | /* adjust offset we're looking for */ | |
7e3617a7 | 4052 | off -= moff; |
9e15db66 AS |
4053 | goto again; |
4054 | } | |
9e15db66 AS |
4055 | |
4056 | if (btf_type_is_ptr(mtype)) { | |
4057 | const struct btf_type *stype; | |
257af63d | 4058 | u32 id; |
9e15db66 | 4059 | |
7e3617a7 MKL |
4060 | if (msize != size || off != moff) { |
4061 | bpf_log(log, | |
4062 | "cannot access ptr member %s with moff %u in struct %s with off %u size %u\n", | |
4063 | mname, moff, tname, off, size); | |
4064 | return -EACCES; | |
4065 | } | |
4066 | ||
257af63d | 4067 | stype = btf_type_skip_modifiers(btf_vmlinux, mtype->type, &id); |
9e15db66 | 4068 | if (btf_type_is_struct(stype)) { |
257af63d | 4069 | *next_btf_id = id; |
9e15db66 AS |
4070 | return PTR_TO_BTF_ID; |
4071 | } | |
4072 | } | |
7e3617a7 MKL |
4073 | |
4074 | /* Allow more flexible access within an int as long as | |
4075 | * it is within mtrue_end. | |
4076 | * Since mtrue_end could be the end of an array, | |
4077 | * that also allows using an array of int as a scratch | |
4078 | * space. e.g. skb->cb[]. | |
4079 | */ | |
4080 | if (off + size > mtrue_end) { | |
4081 | bpf_log(log, | |
4082 | "access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n", | |
4083 | mname, mtrue_end, tname, off, size); | |
4084 | return -EACCES; | |
4085 | } | |
4086 | ||
9e15db66 AS |
4087 | return SCALAR_VALUE; |
4088 | } | |
4089 | bpf_log(log, "struct %s doesn't have field at offset %d\n", tname, off); | |
4090 | return -EINVAL; | |
4091 | } | |
4092 | ||
9cc31b3a AS |
4093 | int btf_resolve_helper_id(struct bpf_verifier_log *log, |
4094 | const struct bpf_func_proto *fn, int arg) | |
4095 | { | |
138b9a05 | 4096 | int id; |
9cc31b3a | 4097 | |
bd0b33b2 | 4098 | if (fn->arg_type[arg] != ARG_PTR_TO_BTF_ID || !btf_vmlinux) |
9cc31b3a | 4099 | return -EINVAL; |
138b9a05 JO |
4100 | id = fn->btf_id[arg]; |
4101 | if (!id || id > btf_vmlinux->nr_types) | |
4102 | return -EINVAL; | |
4103 | return id; | |
9cc31b3a AS |
4104 | } |
4105 | ||
fec56f58 AS |
4106 | static int __get_type_size(struct btf *btf, u32 btf_id, |
4107 | const struct btf_type **bad_type) | |
4108 | { | |
4109 | const struct btf_type *t; | |
4110 | ||
4111 | if (!btf_id) | |
4112 | /* void */ | |
4113 | return 0; | |
4114 | t = btf_type_by_id(btf, btf_id); | |
4115 | while (t && btf_type_is_modifier(t)) | |
4116 | t = btf_type_by_id(btf, t->type); | |
d0f01043 AS |
4117 | if (!t) { |
4118 | *bad_type = btf->types[0]; | |
fec56f58 | 4119 | return -EINVAL; |
d0f01043 | 4120 | } |
fec56f58 AS |
4121 | if (btf_type_is_ptr(t)) |
4122 | /* kernel size of pointer. Not BPF's size of pointer*/ | |
4123 | return sizeof(void *); | |
4124 | if (btf_type_is_int(t) || btf_type_is_enum(t)) | |
4125 | return t->size; | |
4126 | *bad_type = t; | |
4127 | return -EINVAL; | |
4128 | } | |
4129 | ||
4130 | int btf_distill_func_proto(struct bpf_verifier_log *log, | |
4131 | struct btf *btf, | |
4132 | const struct btf_type *func, | |
4133 | const char *tname, | |
4134 | struct btf_func_model *m) | |
4135 | { | |
4136 | const struct btf_param *args; | |
4137 | const struct btf_type *t; | |
4138 | u32 i, nargs; | |
4139 | int ret; | |
4140 | ||
5b92a28a AS |
4141 | if (!func) { |
4142 | /* BTF function prototype doesn't match the verifier types. | |
4143 | * Fall back to 5 u64 args. | |
4144 | */ | |
4145 | for (i = 0; i < 5; i++) | |
4146 | m->arg_size[i] = 8; | |
4147 | m->ret_size = 8; | |
4148 | m->nr_args = 5; | |
4149 | return 0; | |
4150 | } | |
fec56f58 AS |
4151 | args = (const struct btf_param *)(func + 1); |
4152 | nargs = btf_type_vlen(func); | |
4153 | if (nargs >= MAX_BPF_FUNC_ARGS) { | |
4154 | bpf_log(log, | |
4155 | "The function %s has %d arguments. Too many.\n", | |
4156 | tname, nargs); | |
4157 | return -EINVAL; | |
4158 | } | |
4159 | ret = __get_type_size(btf, func->type, &t); | |
4160 | if (ret < 0) { | |
4161 | bpf_log(log, | |
4162 | "The function %s return type %s is unsupported.\n", | |
4163 | tname, btf_kind_str[BTF_INFO_KIND(t->info)]); | |
4164 | return -EINVAL; | |
4165 | } | |
4166 | m->ret_size = ret; | |
4167 | ||
4168 | for (i = 0; i < nargs; i++) { | |
4169 | ret = __get_type_size(btf, args[i].type, &t); | |
4170 | if (ret < 0) { | |
4171 | bpf_log(log, | |
4172 | "The function %s arg%d type %s is unsupported.\n", | |
4173 | tname, i, btf_kind_str[BTF_INFO_KIND(t->info)]); | |
4174 | return -EINVAL; | |
4175 | } | |
4176 | m->arg_size[i] = ret; | |
4177 | } | |
4178 | m->nr_args = nargs; | |
4179 | return 0; | |
4180 | } | |
4181 | ||
be8704ff AS |
4182 | /* Compare BTFs of two functions assuming only scalars and pointers to context. |
4183 | * t1 points to BTF_KIND_FUNC in btf1 | |
4184 | * t2 points to BTF_KIND_FUNC in btf2 | |
4185 | * Returns: | |
4186 | * EINVAL - function prototype mismatch | |
4187 | * EFAULT - verifier bug | |
4188 | * 0 - 99% match. The last 1% is validated by the verifier. | |
4189 | */ | |
2bf0eb9b HY |
4190 | static int btf_check_func_type_match(struct bpf_verifier_log *log, |
4191 | struct btf *btf1, const struct btf_type *t1, | |
4192 | struct btf *btf2, const struct btf_type *t2) | |
be8704ff AS |
4193 | { |
4194 | const struct btf_param *args1, *args2; | |
4195 | const char *fn1, *fn2, *s1, *s2; | |
4196 | u32 nargs1, nargs2, i; | |
4197 | ||
4198 | fn1 = btf_name_by_offset(btf1, t1->name_off); | |
4199 | fn2 = btf_name_by_offset(btf2, t2->name_off); | |
4200 | ||
4201 | if (btf_func_linkage(t1) != BTF_FUNC_GLOBAL) { | |
4202 | bpf_log(log, "%s() is not a global function\n", fn1); | |
4203 | return -EINVAL; | |
4204 | } | |
4205 | if (btf_func_linkage(t2) != BTF_FUNC_GLOBAL) { | |
4206 | bpf_log(log, "%s() is not a global function\n", fn2); | |
4207 | return -EINVAL; | |
4208 | } | |
4209 | ||
4210 | t1 = btf_type_by_id(btf1, t1->type); | |
4211 | if (!t1 || !btf_type_is_func_proto(t1)) | |
4212 | return -EFAULT; | |
4213 | t2 = btf_type_by_id(btf2, t2->type); | |
4214 | if (!t2 || !btf_type_is_func_proto(t2)) | |
4215 | return -EFAULT; | |
4216 | ||
4217 | args1 = (const struct btf_param *)(t1 + 1); | |
4218 | nargs1 = btf_type_vlen(t1); | |
4219 | args2 = (const struct btf_param *)(t2 + 1); | |
4220 | nargs2 = btf_type_vlen(t2); | |
4221 | ||
4222 | if (nargs1 != nargs2) { | |
4223 | bpf_log(log, "%s() has %d args while %s() has %d args\n", | |
4224 | fn1, nargs1, fn2, nargs2); | |
4225 | return -EINVAL; | |
4226 | } | |
4227 | ||
4228 | t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); | |
4229 | t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); | |
4230 | if (t1->info != t2->info) { | |
4231 | bpf_log(log, | |
4232 | "Return type %s of %s() doesn't match type %s of %s()\n", | |
4233 | btf_type_str(t1), fn1, | |
4234 | btf_type_str(t2), fn2); | |
4235 | return -EINVAL; | |
4236 | } | |
4237 | ||
4238 | for (i = 0; i < nargs1; i++) { | |
4239 | t1 = btf_type_skip_modifiers(btf1, args1[i].type, NULL); | |
4240 | t2 = btf_type_skip_modifiers(btf2, args2[i].type, NULL); | |
4241 | ||
4242 | if (t1->info != t2->info) { | |
4243 | bpf_log(log, "arg%d in %s() is %s while %s() has %s\n", | |
4244 | i, fn1, btf_type_str(t1), | |
4245 | fn2, btf_type_str(t2)); | |
4246 | return -EINVAL; | |
4247 | } | |
4248 | if (btf_type_has_size(t1) && t1->size != t2->size) { | |
4249 | bpf_log(log, | |
4250 | "arg%d in %s() has size %d while %s() has %d\n", | |
4251 | i, fn1, t1->size, | |
4252 | fn2, t2->size); | |
4253 | return -EINVAL; | |
4254 | } | |
4255 | ||
4256 | /* global functions are validated with scalars and pointers | |
4257 | * to context only. And only global functions can be replaced. | |
4258 | * Hence type check only those types. | |
4259 | */ | |
4260 | if (btf_type_is_int(t1) || btf_type_is_enum(t1)) | |
4261 | continue; | |
4262 | if (!btf_type_is_ptr(t1)) { | |
4263 | bpf_log(log, | |
4264 | "arg%d in %s() has unrecognized type\n", | |
4265 | i, fn1); | |
4266 | return -EINVAL; | |
4267 | } | |
4268 | t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); | |
4269 | t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); | |
4270 | if (!btf_type_is_struct(t1)) { | |
4271 | bpf_log(log, | |
4272 | "arg%d in %s() is not a pointer to context\n", | |
4273 | i, fn1); | |
4274 | return -EINVAL; | |
4275 | } | |
4276 | if (!btf_type_is_struct(t2)) { | |
4277 | bpf_log(log, | |
4278 | "arg%d in %s() is not a pointer to context\n", | |
4279 | i, fn2); | |
4280 | return -EINVAL; | |
4281 | } | |
4282 | /* This is an optional check to make program writing easier. | |
4283 | * Compare names of structs and report an error to the user. | |
4284 | * btf_prepare_func_args() already checked that t2 struct | |
4285 | * is a context type. btf_prepare_func_args() will check | |
4286 | * later that t1 struct is a context type as well. | |
4287 | */ | |
4288 | s1 = btf_name_by_offset(btf1, t1->name_off); | |
4289 | s2 = btf_name_by_offset(btf2, t2->name_off); | |
4290 | if (strcmp(s1, s2)) { | |
4291 | bpf_log(log, | |
4292 | "arg%d %s(struct %s *) doesn't match %s(struct %s *)\n", | |
4293 | i, fn1, s1, fn2, s2); | |
4294 | return -EINVAL; | |
4295 | } | |
4296 | } | |
4297 | return 0; | |
4298 | } | |
4299 | ||
4300 | /* Compare BTFs of given program with BTF of target program */ | |
4301 | int btf_check_type_match(struct bpf_verifier_env *env, struct bpf_prog *prog, | |
4302 | struct btf *btf2, const struct btf_type *t2) | |
4303 | { | |
4304 | struct btf *btf1 = prog->aux->btf; | |
4305 | const struct btf_type *t1; | |
4306 | u32 btf_id = 0; | |
4307 | ||
4308 | if (!prog->aux->func_info) { | |
4309 | bpf_log(&env->log, "Program extension requires BTF\n"); | |
4310 | return -EINVAL; | |
4311 | } | |
4312 | ||
4313 | btf_id = prog->aux->func_info[0].type_id; | |
4314 | if (!btf_id) | |
4315 | return -EFAULT; | |
4316 | ||
4317 | t1 = btf_type_by_id(btf1, btf_id); | |
4318 | if (!t1 || !btf_type_is_func(t1)) | |
4319 | return -EFAULT; | |
4320 | ||
4321 | return btf_check_func_type_match(&env->log, btf1, t1, btf2, t2); | |
4322 | } | |
4323 | ||
51c39bb1 AS |
4324 | /* Compare BTF of a function with given bpf_reg_state. |
4325 | * Returns: | |
4326 | * EFAULT - there is a verifier bug. Abort verification. | |
4327 | * EINVAL - there is a type mismatch or BTF is not available. | |
4328 | * 0 - BTF matches with what bpf_reg_state expects. | |
4329 | * Only PTR_TO_CTX and SCALAR_VALUE states are recognized. | |
4330 | */ | |
4331 | int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog, | |
4332 | struct bpf_reg_state *reg) | |
8c1b6e69 | 4333 | { |
8c1b6e69 AS |
4334 | struct bpf_verifier_log *log = &env->log; |
4335 | struct bpf_prog *prog = env->prog; | |
4336 | struct btf *btf = prog->aux->btf; | |
4337 | const struct btf_param *args; | |
4338 | const struct btf_type *t; | |
4339 | u32 i, nargs, btf_id; | |
4340 | const char *tname; | |
4341 | ||
4342 | if (!prog->aux->func_info) | |
51c39bb1 | 4343 | return -EINVAL; |
8c1b6e69 AS |
4344 | |
4345 | btf_id = prog->aux->func_info[subprog].type_id; | |
4346 | if (!btf_id) | |
51c39bb1 | 4347 | return -EFAULT; |
8c1b6e69 AS |
4348 | |
4349 | if (prog->aux->func_info_aux[subprog].unreliable) | |
51c39bb1 | 4350 | return -EINVAL; |
8c1b6e69 AS |
4351 | |
4352 | t = btf_type_by_id(btf, btf_id); | |
4353 | if (!t || !btf_type_is_func(t)) { | |
51c39bb1 AS |
4354 | /* These checks were already done by the verifier while loading |
4355 | * struct bpf_func_info | |
4356 | */ | |
4357 | bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n", | |
8c1b6e69 | 4358 | subprog); |
51c39bb1 | 4359 | return -EFAULT; |
8c1b6e69 AS |
4360 | } |
4361 | tname = btf_name_by_offset(btf, t->name_off); | |
4362 | ||
4363 | t = btf_type_by_id(btf, t->type); | |
4364 | if (!t || !btf_type_is_func_proto(t)) { | |
51c39bb1 AS |
4365 | bpf_log(log, "Invalid BTF of func %s\n", tname); |
4366 | return -EFAULT; | |
8c1b6e69 AS |
4367 | } |
4368 | args = (const struct btf_param *)(t + 1); | |
4369 | nargs = btf_type_vlen(t); | |
4370 | if (nargs > 5) { | |
4371 | bpf_log(log, "Function %s has %d > 5 args\n", tname, nargs); | |
4372 | goto out; | |
4373 | } | |
4374 | /* check that BTF function arguments match actual types that the | |
4375 | * verifier sees. | |
4376 | */ | |
4377 | for (i = 0; i < nargs; i++) { | |
4378 | t = btf_type_by_id(btf, args[i].type); | |
4379 | while (btf_type_is_modifier(t)) | |
4380 | t = btf_type_by_id(btf, t->type); | |
4381 | if (btf_type_is_int(t) || btf_type_is_enum(t)) { | |
4382 | if (reg[i + 1].type == SCALAR_VALUE) | |
4383 | continue; | |
4384 | bpf_log(log, "R%d is not a scalar\n", i + 1); | |
4385 | goto out; | |
4386 | } | |
4387 | if (btf_type_is_ptr(t)) { | |
4388 | if (reg[i + 1].type == SCALAR_VALUE) { | |
4389 | bpf_log(log, "R%d is not a pointer\n", i + 1); | |
4390 | goto out; | |
4391 | } | |
51c39bb1 AS |
4392 | /* If function expects ctx type in BTF check that caller |
4393 | * is passing PTR_TO_CTX. | |
8c1b6e69 | 4394 | */ |
51c39bb1 AS |
4395 | if (btf_get_prog_ctx_type(log, btf, t, prog->type, i)) { |
4396 | if (reg[i + 1].type != PTR_TO_CTX) { | |
4397 | bpf_log(log, | |
4398 | "arg#%d expected pointer to ctx, but got %s\n", | |
4399 | i, btf_kind_str[BTF_INFO_KIND(t->info)]); | |
4400 | goto out; | |
4401 | } | |
4402 | if (check_ctx_reg(env, ®[i + 1], i + 1)) | |
4403 | goto out; | |
4404 | continue; | |
4405 | } | |
8c1b6e69 | 4406 | } |
51c39bb1 AS |
4407 | bpf_log(log, "Unrecognized arg#%d type %s\n", |
4408 | i, btf_kind_str[BTF_INFO_KIND(t->info)]); | |
8c1b6e69 AS |
4409 | goto out; |
4410 | } | |
4411 | return 0; | |
4412 | out: | |
51c39bb1 AS |
4413 | /* Compiler optimizations can remove arguments from static functions |
4414 | * or mismatched type can be passed into a global function. | |
4415 | * In such cases mark the function as unreliable from BTF point of view. | |
4416 | */ | |
8c1b6e69 | 4417 | prog->aux->func_info_aux[subprog].unreliable = true; |
51c39bb1 AS |
4418 | return -EINVAL; |
4419 | } | |
4420 | ||
4421 | /* Convert BTF of a function into bpf_reg_state if possible | |
4422 | * Returns: | |
4423 | * EFAULT - there is a verifier bug. Abort verification. | |
4424 | * EINVAL - cannot convert BTF. | |
4425 | * 0 - Successfully converted BTF into bpf_reg_state | |
4426 | * (either PTR_TO_CTX or SCALAR_VALUE). | |
4427 | */ | |
4428 | int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog, | |
4429 | struct bpf_reg_state *reg) | |
4430 | { | |
4431 | struct bpf_verifier_log *log = &env->log; | |
4432 | struct bpf_prog *prog = env->prog; | |
be8704ff | 4433 | enum bpf_prog_type prog_type = prog->type; |
51c39bb1 AS |
4434 | struct btf *btf = prog->aux->btf; |
4435 | const struct btf_param *args; | |
4436 | const struct btf_type *t; | |
4437 | u32 i, nargs, btf_id; | |
4438 | const char *tname; | |
4439 | ||
4440 | if (!prog->aux->func_info || | |
4441 | prog->aux->func_info_aux[subprog].linkage != BTF_FUNC_GLOBAL) { | |
4442 | bpf_log(log, "Verifier bug\n"); | |
4443 | return -EFAULT; | |
4444 | } | |
4445 | ||
4446 | btf_id = prog->aux->func_info[subprog].type_id; | |
4447 | if (!btf_id) { | |
4448 | bpf_log(log, "Global functions need valid BTF\n"); | |
4449 | return -EFAULT; | |
4450 | } | |
4451 | ||
4452 | t = btf_type_by_id(btf, btf_id); | |
4453 | if (!t || !btf_type_is_func(t)) { | |
4454 | /* These checks were already done by the verifier while loading | |
4455 | * struct bpf_func_info | |
4456 | */ | |
4457 | bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n", | |
4458 | subprog); | |
4459 | return -EFAULT; | |
4460 | } | |
4461 | tname = btf_name_by_offset(btf, t->name_off); | |
4462 | ||
4463 | if (log->level & BPF_LOG_LEVEL) | |
4464 | bpf_log(log, "Validating %s() func#%d...\n", | |
4465 | tname, subprog); | |
4466 | ||
4467 | if (prog->aux->func_info_aux[subprog].unreliable) { | |
4468 | bpf_log(log, "Verifier bug in function %s()\n", tname); | |
4469 | return -EFAULT; | |
4470 | } | |
be8704ff AS |
4471 | if (prog_type == BPF_PROG_TYPE_EXT) |
4472 | prog_type = prog->aux->linked_prog->type; | |
51c39bb1 AS |
4473 | |
4474 | t = btf_type_by_id(btf, t->type); | |
4475 | if (!t || !btf_type_is_func_proto(t)) { | |
4476 | bpf_log(log, "Invalid type of function %s()\n", tname); | |
4477 | return -EFAULT; | |
4478 | } | |
4479 | args = (const struct btf_param *)(t + 1); | |
4480 | nargs = btf_type_vlen(t); | |
4481 | if (nargs > 5) { | |
4482 | bpf_log(log, "Global function %s() with %d > 5 args. Buggy compiler.\n", | |
4483 | tname, nargs); | |
4484 | return -EINVAL; | |
4485 | } | |
4486 | /* check that function returns int */ | |
4487 | t = btf_type_by_id(btf, t->type); | |
4488 | while (btf_type_is_modifier(t)) | |
4489 | t = btf_type_by_id(btf, t->type); | |
4490 | if (!btf_type_is_int(t) && !btf_type_is_enum(t)) { | |
4491 | bpf_log(log, | |
4492 | "Global function %s() doesn't return scalar. Only those are supported.\n", | |
4493 | tname); | |
4494 | return -EINVAL; | |
4495 | } | |
4496 | /* Convert BTF function arguments into verifier types. | |
4497 | * Only PTR_TO_CTX and SCALAR are supported atm. | |
4498 | */ | |
4499 | for (i = 0; i < nargs; i++) { | |
4500 | t = btf_type_by_id(btf, args[i].type); | |
4501 | while (btf_type_is_modifier(t)) | |
4502 | t = btf_type_by_id(btf, t->type); | |
4503 | if (btf_type_is_int(t) || btf_type_is_enum(t)) { | |
4504 | reg[i + 1].type = SCALAR_VALUE; | |
4505 | continue; | |
4506 | } | |
4507 | if (btf_type_is_ptr(t) && | |
be8704ff | 4508 | btf_get_prog_ctx_type(log, btf, t, prog_type, i)) { |
51c39bb1 AS |
4509 | reg[i + 1].type = PTR_TO_CTX; |
4510 | continue; | |
4511 | } | |
4512 | bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n", | |
4513 | i, btf_kind_str[BTF_INFO_KIND(t->info)], tname); | |
4514 | return -EINVAL; | |
4515 | } | |
8c1b6e69 AS |
4516 | return 0; |
4517 | } | |
4518 | ||
b00b8dae MKL |
4519 | void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj, |
4520 | struct seq_file *m) | |
4521 | { | |
4522 | const struct btf_type *t = btf_type_by_id(btf, type_id); | |
4523 | ||
4524 | btf_type_ops(t)->seq_show(btf, t, type_id, obj, 0, m); | |
4525 | } | |
f56a653c | 4526 | |
3481e64b QM |
4527 | #ifdef CONFIG_PROC_FS |
4528 | static void bpf_btf_show_fdinfo(struct seq_file *m, struct file *filp) | |
4529 | { | |
4530 | const struct btf *btf = filp->private_data; | |
4531 | ||
4532 | seq_printf(m, "btf_id:\t%u\n", btf->id); | |
4533 | } | |
4534 | #endif | |
4535 | ||
f56a653c MKL |
4536 | static int btf_release(struct inode *inode, struct file *filp) |
4537 | { | |
4538 | btf_put(filp->private_data); | |
4539 | return 0; | |
4540 | } | |
4541 | ||
60197cfb | 4542 | const struct file_operations btf_fops = { |
3481e64b QM |
4543 | #ifdef CONFIG_PROC_FS |
4544 | .show_fdinfo = bpf_btf_show_fdinfo, | |
4545 | #endif | |
f56a653c MKL |
4546 | .release = btf_release, |
4547 | }; | |
4548 | ||
78958fca MKL |
4549 | static int __btf_new_fd(struct btf *btf) |
4550 | { | |
4551 | return anon_inode_getfd("btf", &btf_fops, btf, O_RDONLY | O_CLOEXEC); | |
4552 | } | |
4553 | ||
f56a653c MKL |
4554 | int btf_new_fd(const union bpf_attr *attr) |
4555 | { | |
4556 | struct btf *btf; | |
78958fca | 4557 | int ret; |
f56a653c MKL |
4558 | |
4559 | btf = btf_parse(u64_to_user_ptr(attr->btf), | |
4560 | attr->btf_size, attr->btf_log_level, | |
4561 | u64_to_user_ptr(attr->btf_log_buf), | |
4562 | attr->btf_log_size); | |
4563 | if (IS_ERR(btf)) | |
4564 | return PTR_ERR(btf); | |
4565 | ||
78958fca MKL |
4566 | ret = btf_alloc_id(btf); |
4567 | if (ret) { | |
4568 | btf_free(btf); | |
4569 | return ret; | |
4570 | } | |
4571 | ||
4572 | /* | |
4573 | * The BTF ID is published to the userspace. | |
4574 | * All BTF free must go through call_rcu() from | |
4575 | * now on (i.e. free by calling btf_put()). | |
4576 | */ | |
4577 | ||
4578 | ret = __btf_new_fd(btf); | |
4579 | if (ret < 0) | |
f56a653c MKL |
4580 | btf_put(btf); |
4581 | ||
78958fca | 4582 | return ret; |
f56a653c MKL |
4583 | } |
4584 | ||
4585 | struct btf *btf_get_by_fd(int fd) | |
4586 | { | |
4587 | struct btf *btf; | |
4588 | struct fd f; | |
4589 | ||
4590 | f = fdget(fd); | |
4591 | ||
4592 | if (!f.file) | |
4593 | return ERR_PTR(-EBADF); | |
4594 | ||
4595 | if (f.file->f_op != &btf_fops) { | |
4596 | fdput(f); | |
4597 | return ERR_PTR(-EINVAL); | |
4598 | } | |
4599 | ||
4600 | btf = f.file->private_data; | |
78958fca | 4601 | refcount_inc(&btf->refcnt); |
f56a653c MKL |
4602 | fdput(f); |
4603 | ||
4604 | return btf; | |
4605 | } | |
60197cfb MKL |
4606 | |
4607 | int btf_get_info_by_fd(const struct btf *btf, | |
4608 | const union bpf_attr *attr, | |
4609 | union bpf_attr __user *uattr) | |
4610 | { | |
62dab84c | 4611 | struct bpf_btf_info __user *uinfo; |
5c6f2588 | 4612 | struct bpf_btf_info info; |
62dab84c MKL |
4613 | u32 info_copy, btf_copy; |
4614 | void __user *ubtf; | |
4615 | u32 uinfo_len; | |
60197cfb | 4616 | |
62dab84c MKL |
4617 | uinfo = u64_to_user_ptr(attr->info.info); |
4618 | uinfo_len = attr->info.info_len; | |
4619 | ||
4620 | info_copy = min_t(u32, uinfo_len, sizeof(info)); | |
5c6f2588 | 4621 | memset(&info, 0, sizeof(info)); |
62dab84c MKL |
4622 | if (copy_from_user(&info, uinfo, info_copy)) |
4623 | return -EFAULT; | |
4624 | ||
4625 | info.id = btf->id; | |
4626 | ubtf = u64_to_user_ptr(info.btf); | |
4627 | btf_copy = min_t(u32, btf->data_size, info.btf_size); | |
4628 | if (copy_to_user(ubtf, btf->data, btf_copy)) | |
4629 | return -EFAULT; | |
4630 | info.btf_size = btf->data_size; | |
4631 | ||
4632 | if (copy_to_user(uinfo, &info, info_copy) || | |
4633 | put_user(info_copy, &uattr->info.info_len)) | |
60197cfb MKL |
4634 | return -EFAULT; |
4635 | ||
4636 | return 0; | |
4637 | } | |
78958fca MKL |
4638 | |
4639 | int btf_get_fd_by_id(u32 id) | |
4640 | { | |
4641 | struct btf *btf; | |
4642 | int fd; | |
4643 | ||
4644 | rcu_read_lock(); | |
4645 | btf = idr_find(&btf_idr, id); | |
4646 | if (!btf || !refcount_inc_not_zero(&btf->refcnt)) | |
4647 | btf = ERR_PTR(-ENOENT); | |
4648 | rcu_read_unlock(); | |
4649 | ||
4650 | if (IS_ERR(btf)) | |
4651 | return PTR_ERR(btf); | |
4652 | ||
4653 | fd = __btf_new_fd(btf); | |
4654 | if (fd < 0) | |
4655 | btf_put(btf); | |
4656 | ||
4657 | return fd; | |
4658 | } | |
4659 | ||
4660 | u32 btf_id(const struct btf *btf) | |
4661 | { | |
4662 | return btf->id; | |
4663 | } |