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c561d110 | 1 | // SPDX-License-Identifier: GPL-2.0 |
69b693f0 MKL |
2 | /* Copyright (c) 2018 Facebook */ |
3 | ||
4 | #include <uapi/linux/btf.h> | |
91cc1a99 AS |
5 | #include <uapi/linux/bpf.h> |
6 | #include <uapi/linux/bpf_perf_event.h> | |
69b693f0 | 7 | #include <uapi/linux/types.h> |
b00b8dae | 8 | #include <linux/seq_file.h> |
69b693f0 | 9 | #include <linux/compiler.h> |
2667a262 | 10 | #include <linux/ctype.h> |
69b693f0 MKL |
11 | #include <linux/errno.h> |
12 | #include <linux/slab.h> | |
f56a653c MKL |
13 | #include <linux/anon_inodes.h> |
14 | #include <linux/file.h> | |
69b693f0 MKL |
15 | #include <linux/uaccess.h> |
16 | #include <linux/kernel.h> | |
78958fca | 17 | #include <linux/idr.h> |
f80442a4 | 18 | #include <linux/sort.h> |
69b693f0 MKL |
19 | #include <linux/bpf_verifier.h> |
20 | #include <linux/btf.h> | |
49f4e672 | 21 | #include <linux/btf_ids.h> |
91cc1a99 AS |
22 | #include <linux/skmsg.h> |
23 | #include <linux/perf_event.h> | |
eae2e83e | 24 | #include <linux/bsearch.h> |
36e68442 AN |
25 | #include <linux/kobject.h> |
26 | #include <linux/sysfs.h> | |
91cc1a99 | 27 | #include <net/sock.h> |
1e89106d | 28 | #include "../tools/lib/bpf/relo_core.h" |
69b693f0 MKL |
29 | |
30 | /* BTF (BPF Type Format) is the meta data format which describes | |
31 | * the data types of BPF program/map. Hence, it basically focus | |
32 | * on the C programming language which the modern BPF is primary | |
33 | * using. | |
34 | * | |
35 | * ELF Section: | |
36 | * ~~~~~~~~~~~ | |
37 | * The BTF data is stored under the ".BTF" ELF section | |
38 | * | |
39 | * struct btf_type: | |
40 | * ~~~~~~~~~~~~~~~ | |
41 | * Each 'struct btf_type' object describes a C data type. | |
42 | * Depending on the type it is describing, a 'struct btf_type' | |
43 | * object may be followed by more data. F.e. | |
44 | * To describe an array, 'struct btf_type' is followed by | |
45 | * 'struct btf_array'. | |
46 | * | |
47 | * 'struct btf_type' and any extra data following it are | |
48 | * 4 bytes aligned. | |
49 | * | |
50 | * Type section: | |
51 | * ~~~~~~~~~~~~~ | |
52 | * The BTF type section contains a list of 'struct btf_type' objects. | |
53 | * Each one describes a C type. Recall from the above section | |
54 | * that a 'struct btf_type' object could be immediately followed by extra | |
8fb33b60 | 55 | * data in order to describe some particular C types. |
69b693f0 MKL |
56 | * |
57 | * type_id: | |
58 | * ~~~~~~~ | |
59 | * Each btf_type object is identified by a type_id. The type_id | |
60 | * is implicitly implied by the location of the btf_type object in | |
61 | * the BTF type section. The first one has type_id 1. The second | |
62 | * one has type_id 2...etc. Hence, an earlier btf_type has | |
63 | * a smaller type_id. | |
64 | * | |
65 | * A btf_type object may refer to another btf_type object by using | |
66 | * type_id (i.e. the "type" in the "struct btf_type"). | |
67 | * | |
68 | * NOTE that we cannot assume any reference-order. | |
69 | * A btf_type object can refer to an earlier btf_type object | |
70 | * but it can also refer to a later btf_type object. | |
71 | * | |
72 | * For example, to describe "const void *". A btf_type | |
73 | * object describing "const" may refer to another btf_type | |
74 | * object describing "void *". This type-reference is done | |
75 | * by specifying type_id: | |
76 | * | |
77 | * [1] CONST (anon) type_id=2 | |
78 | * [2] PTR (anon) type_id=0 | |
79 | * | |
80 | * The above is the btf_verifier debug log: | |
81 | * - Each line started with "[?]" is a btf_type object | |
82 | * - [?] is the type_id of the btf_type object. | |
83 | * - CONST/PTR is the BTF_KIND_XXX | |
84 | * - "(anon)" is the name of the type. It just | |
85 | * happens that CONST and PTR has no name. | |
86 | * - type_id=XXX is the 'u32 type' in btf_type | |
87 | * | |
88 | * NOTE: "void" has type_id 0 | |
89 | * | |
90 | * String section: | |
91 | * ~~~~~~~~~~~~~~ | |
92 | * The BTF string section contains the names used by the type section. | |
93 | * Each string is referred by an "offset" from the beginning of the | |
94 | * string section. | |
95 | * | |
96 | * Each string is '\0' terminated. | |
97 | * | |
98 | * The first character in the string section must be '\0' | |
99 | * which is used to mean 'anonymous'. Some btf_type may not | |
100 | * have a name. | |
101 | */ | |
102 | ||
103 | /* BTF verification: | |
104 | * | |
105 | * To verify BTF data, two passes are needed. | |
106 | * | |
107 | * Pass #1 | |
108 | * ~~~~~~~ | |
109 | * The first pass is to collect all btf_type objects to | |
110 | * an array: "btf->types". | |
111 | * | |
112 | * Depending on the C type that a btf_type is describing, | |
113 | * a btf_type may be followed by extra data. We don't know | |
114 | * how many btf_type is there, and more importantly we don't | |
115 | * know where each btf_type is located in the type section. | |
116 | * | |
117 | * Without knowing the location of each type_id, most verifications | |
118 | * cannot be done. e.g. an earlier btf_type may refer to a later | |
119 | * btf_type (recall the "const void *" above), so we cannot | |
120 | * check this type-reference in the first pass. | |
121 | * | |
122 | * In the first pass, it still does some verifications (e.g. | |
123 | * checking the name is a valid offset to the string section). | |
eb3f595d MKL |
124 | * |
125 | * Pass #2 | |
126 | * ~~~~~~~ | |
127 | * The main focus is to resolve a btf_type that is referring | |
128 | * to another type. | |
129 | * | |
130 | * We have to ensure the referring type: | |
131 | * 1) does exist in the BTF (i.e. in btf->types[]) | |
132 | * 2) does not cause a loop: | |
133 | * struct A { | |
134 | * struct B b; | |
135 | * }; | |
136 | * | |
137 | * struct B { | |
138 | * struct A a; | |
139 | * }; | |
140 | * | |
141 | * btf_type_needs_resolve() decides if a btf_type needs | |
142 | * to be resolved. | |
143 | * | |
144 | * The needs_resolve type implements the "resolve()" ops which | |
145 | * essentially does a DFS and detects backedge. | |
146 | * | |
147 | * During resolve (or DFS), different C types have different | |
148 | * "RESOLVED" conditions. | |
149 | * | |
150 | * When resolving a BTF_KIND_STRUCT, we need to resolve all its | |
151 | * members because a member is always referring to another | |
152 | * type. A struct's member can be treated as "RESOLVED" if | |
153 | * it is referring to a BTF_KIND_PTR. Otherwise, the | |
154 | * following valid C struct would be rejected: | |
155 | * | |
156 | * struct A { | |
157 | * int m; | |
158 | * struct A *a; | |
159 | * }; | |
160 | * | |
161 | * When resolving a BTF_KIND_PTR, it needs to keep resolving if | |
162 | * it is referring to another BTF_KIND_PTR. Otherwise, we cannot | |
163 | * detect a pointer loop, e.g.: | |
164 | * BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR + | |
165 | * ^ | | |
166 | * +-----------------------------------------+ | |
167 | * | |
69b693f0 MKL |
168 | */ |
169 | ||
b1e8818c | 170 | #define BITS_PER_U128 (sizeof(u64) * BITS_PER_BYTE * 2) |
69b693f0 MKL |
171 | #define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1) |
172 | #define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK) | |
173 | #define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3) | |
174 | #define BITS_ROUNDUP_BYTES(bits) \ | |
175 | (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits)) | |
176 | ||
b1828f0b | 177 | #define BTF_INFO_MASK 0x9f00ffff |
aea2f7b8 MKL |
178 | #define BTF_INT_MASK 0x0fffffff |
179 | #define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE) | |
180 | #define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET) | |
181 | ||
69b693f0 MKL |
182 | /* 16MB for 64k structs and each has 16 members and |
183 | * a few MB spaces for the string section. | |
184 | * The hard limit is S32_MAX. | |
185 | */ | |
186 | #define BTF_MAX_SIZE (16 * 1024 * 1024) | |
69b693f0 | 187 | |
eb3f595d MKL |
188 | #define for_each_member_from(i, from, struct_type, member) \ |
189 | for (i = from, member = btf_type_member(struct_type) + from; \ | |
190 | i < btf_type_vlen(struct_type); \ | |
191 | i++, member++) | |
192 | ||
1dc92851 DB |
193 | #define for_each_vsi_from(i, from, struct_type, member) \ |
194 | for (i = from, member = btf_type_var_secinfo(struct_type) + from; \ | |
195 | i < btf_type_vlen(struct_type); \ | |
196 | i++, member++) | |
197 | ||
1b9ed84e QM |
198 | DEFINE_IDR(btf_idr); |
199 | DEFINE_SPINLOCK(btf_idr_lock); | |
78958fca | 200 | |
dee872e1 KKD |
201 | enum btf_kfunc_hook { |
202 | BTF_KFUNC_HOOK_XDP, | |
203 | BTF_KFUNC_HOOK_TC, | |
204 | BTF_KFUNC_HOOK_STRUCT_OPS, | |
205 | BTF_KFUNC_HOOK_MAX, | |
206 | }; | |
207 | ||
208 | enum { | |
209 | BTF_KFUNC_SET_MAX_CNT = 32, | |
5ce937d6 | 210 | BTF_DTOR_KFUNC_MAX_CNT = 256, |
dee872e1 KKD |
211 | }; |
212 | ||
213 | struct btf_kfunc_set_tab { | |
214 | struct btf_id_set *sets[BTF_KFUNC_HOOK_MAX][BTF_KFUNC_TYPE_MAX]; | |
215 | }; | |
216 | ||
5ce937d6 KKD |
217 | struct btf_id_dtor_kfunc_tab { |
218 | u32 cnt; | |
219 | struct btf_id_dtor_kfunc dtors[]; | |
220 | }; | |
221 | ||
69b693f0 | 222 | struct btf { |
f80442a4 | 223 | void *data; |
69b693f0 | 224 | struct btf_type **types; |
eb3f595d MKL |
225 | u32 *resolved_ids; |
226 | u32 *resolved_sizes; | |
69b693f0 MKL |
227 | const char *strings; |
228 | void *nohdr_data; | |
f80442a4 | 229 | struct btf_header hdr; |
951bb646 | 230 | u32 nr_types; /* includes VOID for base BTF */ |
69b693f0 MKL |
231 | u32 types_size; |
232 | u32 data_size; | |
f56a653c | 233 | refcount_t refcnt; |
78958fca MKL |
234 | u32 id; |
235 | struct rcu_head rcu; | |
dee872e1 | 236 | struct btf_kfunc_set_tab *kfunc_set_tab; |
5ce937d6 | 237 | struct btf_id_dtor_kfunc_tab *dtor_kfunc_tab; |
951bb646 AN |
238 | |
239 | /* split BTF support */ | |
240 | struct btf *base_btf; | |
241 | u32 start_id; /* first type ID in this BTF (0 for base BTF) */ | |
242 | u32 start_str_off; /* first string offset (0 for base BTF) */ | |
53297220 AN |
243 | char name[MODULE_NAME_LEN]; |
244 | bool kernel_btf; | |
69b693f0 MKL |
245 | }; |
246 | ||
eb3f595d MKL |
247 | enum verifier_phase { |
248 | CHECK_META, | |
249 | CHECK_TYPE, | |
250 | }; | |
251 | ||
252 | struct resolve_vertex { | |
253 | const struct btf_type *t; | |
254 | u32 type_id; | |
255 | u16 next_member; | |
256 | }; | |
257 | ||
258 | enum visit_state { | |
259 | NOT_VISITED, | |
260 | VISITED, | |
261 | RESOLVED, | |
262 | }; | |
263 | ||
264 | enum resolve_mode { | |
265 | RESOLVE_TBD, /* To Be Determined */ | |
266 | RESOLVE_PTR, /* Resolving for Pointer */ | |
267 | RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union | |
268 | * or array | |
269 | */ | |
270 | }; | |
271 | ||
272 | #define MAX_RESOLVE_DEPTH 32 | |
273 | ||
f80442a4 MKL |
274 | struct btf_sec_info { |
275 | u32 off; | |
276 | u32 len; | |
277 | }; | |
278 | ||
69b693f0 MKL |
279 | struct btf_verifier_env { |
280 | struct btf *btf; | |
eb3f595d MKL |
281 | u8 *visit_states; |
282 | struct resolve_vertex stack[MAX_RESOLVE_DEPTH]; | |
69b693f0 MKL |
283 | struct bpf_verifier_log log; |
284 | u32 log_type_id; | |
eb3f595d MKL |
285 | u32 top_stack; |
286 | enum verifier_phase phase; | |
287 | enum resolve_mode resolve_mode; | |
69b693f0 MKL |
288 | }; |
289 | ||
290 | static const char * const btf_kind_str[NR_BTF_KINDS] = { | |
291 | [BTF_KIND_UNKN] = "UNKNOWN", | |
292 | [BTF_KIND_INT] = "INT", | |
293 | [BTF_KIND_PTR] = "PTR", | |
294 | [BTF_KIND_ARRAY] = "ARRAY", | |
295 | [BTF_KIND_STRUCT] = "STRUCT", | |
296 | [BTF_KIND_UNION] = "UNION", | |
297 | [BTF_KIND_ENUM] = "ENUM", | |
298 | [BTF_KIND_FWD] = "FWD", | |
299 | [BTF_KIND_TYPEDEF] = "TYPEDEF", | |
300 | [BTF_KIND_VOLATILE] = "VOLATILE", | |
301 | [BTF_KIND_CONST] = "CONST", | |
302 | [BTF_KIND_RESTRICT] = "RESTRICT", | |
2667a262 MKL |
303 | [BTF_KIND_FUNC] = "FUNC", |
304 | [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO", | |
1dc92851 DB |
305 | [BTF_KIND_VAR] = "VAR", |
306 | [BTF_KIND_DATASEC] = "DATASEC", | |
b1828f0b | 307 | [BTF_KIND_FLOAT] = "FLOAT", |
223f903e | 308 | [BTF_KIND_DECL_TAG] = "DECL_TAG", |
8c42d2fa | 309 | [BTF_KIND_TYPE_TAG] = "TYPE_TAG", |
69b693f0 MKL |
310 | }; |
311 | ||
e6ac2450 | 312 | const char *btf_type_str(const struct btf_type *t) |
be8704ff AS |
313 | { |
314 | return btf_kind_str[BTF_INFO_KIND(t->info)]; | |
315 | } | |
316 | ||
31d0bc81 AM |
317 | /* Chunk size we use in safe copy of data to be shown. */ |
318 | #define BTF_SHOW_OBJ_SAFE_SIZE 32 | |
319 | ||
320 | /* | |
321 | * This is the maximum size of a base type value (equivalent to a | |
322 | * 128-bit int); if we are at the end of our safe buffer and have | |
323 | * less than 16 bytes space we can't be assured of being able | |
324 | * to copy the next type safely, so in such cases we will initiate | |
325 | * a new copy. | |
326 | */ | |
327 | #define BTF_SHOW_OBJ_BASE_TYPE_SIZE 16 | |
328 | ||
329 | /* Type name size */ | |
330 | #define BTF_SHOW_NAME_SIZE 80 | |
331 | ||
332 | /* | |
333 | * Common data to all BTF show operations. Private show functions can add | |
334 | * their own data to a structure containing a struct btf_show and consult it | |
335 | * in the show callback. See btf_type_show() below. | |
336 | * | |
337 | * One challenge with showing nested data is we want to skip 0-valued | |
338 | * data, but in order to figure out whether a nested object is all zeros | |
339 | * we need to walk through it. As a result, we need to make two passes | |
340 | * when handling structs, unions and arrays; the first path simply looks | |
341 | * for nonzero data, while the second actually does the display. The first | |
342 | * pass is signalled by show->state.depth_check being set, and if we | |
343 | * encounter a non-zero value we set show->state.depth_to_show to | |
344 | * the depth at which we encountered it. When we have completed the | |
345 | * first pass, we will know if anything needs to be displayed if | |
346 | * depth_to_show > depth. See btf_[struct,array]_show() for the | |
347 | * implementation of this. | |
348 | * | |
349 | * Another problem is we want to ensure the data for display is safe to | |
350 | * access. To support this, the anonymous "struct {} obj" tracks the data | |
351 | * object and our safe copy of it. We copy portions of the data needed | |
352 | * to the object "copy" buffer, but because its size is limited to | |
353 | * BTF_SHOW_OBJ_COPY_LEN bytes, multiple copies may be required as we | |
354 | * traverse larger objects for display. | |
355 | * | |
356 | * The various data type show functions all start with a call to | |
357 | * btf_show_start_type() which returns a pointer to the safe copy | |
358 | * of the data needed (or if BTF_SHOW_UNSAFE is specified, to the | |
359 | * raw data itself). btf_show_obj_safe() is responsible for | |
360 | * using copy_from_kernel_nofault() to update the safe data if necessary | |
361 | * as we traverse the object's data. skbuff-like semantics are | |
362 | * used: | |
363 | * | |
364 | * - obj.head points to the start of the toplevel object for display | |
365 | * - obj.size is the size of the toplevel object | |
366 | * - obj.data points to the current point in the original data at | |
367 | * which our safe data starts. obj.data will advance as we copy | |
368 | * portions of the data. | |
369 | * | |
370 | * In most cases a single copy will suffice, but larger data structures | |
371 | * such as "struct task_struct" will require many copies. The logic in | |
372 | * btf_show_obj_safe() handles the logic that determines if a new | |
373 | * copy_from_kernel_nofault() is needed. | |
374 | */ | |
375 | struct btf_show { | |
376 | u64 flags; | |
377 | void *target; /* target of show operation (seq file, buffer) */ | |
378 | void (*showfn)(struct btf_show *show, const char *fmt, va_list args); | |
379 | const struct btf *btf; | |
380 | /* below are used during iteration */ | |
381 | struct { | |
382 | u8 depth; | |
383 | u8 depth_to_show; | |
384 | u8 depth_check; | |
385 | u8 array_member:1, | |
386 | array_terminated:1; | |
387 | u16 array_encoding; | |
388 | u32 type_id; | |
389 | int status; /* non-zero for error */ | |
390 | const struct btf_type *type; | |
391 | const struct btf_member *member; | |
392 | char name[BTF_SHOW_NAME_SIZE]; /* space for member name/type */ | |
393 | } state; | |
394 | struct { | |
395 | u32 size; | |
396 | void *head; | |
397 | void *data; | |
398 | u8 safe[BTF_SHOW_OBJ_SAFE_SIZE]; | |
399 | } obj; | |
400 | }; | |
401 | ||
69b693f0 MKL |
402 | struct btf_kind_operations { |
403 | s32 (*check_meta)(struct btf_verifier_env *env, | |
404 | const struct btf_type *t, | |
405 | u32 meta_left); | |
eb3f595d MKL |
406 | int (*resolve)(struct btf_verifier_env *env, |
407 | const struct resolve_vertex *v); | |
179cde8c MKL |
408 | int (*check_member)(struct btf_verifier_env *env, |
409 | const struct btf_type *struct_type, | |
410 | const struct btf_member *member, | |
411 | const struct btf_type *member_type); | |
9d5f9f70 YS |
412 | int (*check_kflag_member)(struct btf_verifier_env *env, |
413 | const struct btf_type *struct_type, | |
414 | const struct btf_member *member, | |
415 | const struct btf_type *member_type); | |
69b693f0 MKL |
416 | void (*log_details)(struct btf_verifier_env *env, |
417 | const struct btf_type *t); | |
31d0bc81 | 418 | void (*show)(const struct btf *btf, const struct btf_type *t, |
b00b8dae | 419 | u32 type_id, void *data, u8 bits_offsets, |
31d0bc81 | 420 | struct btf_show *show); |
69b693f0 MKL |
421 | }; |
422 | ||
423 | static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS]; | |
424 | static struct btf_type btf_void; | |
425 | ||
2667a262 MKL |
426 | static int btf_resolve(struct btf_verifier_env *env, |
427 | const struct btf_type *t, u32 type_id); | |
428 | ||
d7e7b42f YS |
429 | static int btf_func_check(struct btf_verifier_env *env, |
430 | const struct btf_type *t); | |
431 | ||
eb3f595d MKL |
432 | static bool btf_type_is_modifier(const struct btf_type *t) |
433 | { | |
434 | /* Some of them is not strictly a C modifier | |
435 | * but they are grouped into the same bucket | |
436 | * for BTF concern: | |
437 | * A type (t) that refers to another | |
438 | * type through t->type AND its size cannot | |
439 | * be determined without following the t->type. | |
440 | * | |
441 | * ptr does not fall into this bucket | |
442 | * because its size is always sizeof(void *). | |
443 | */ | |
444 | switch (BTF_INFO_KIND(t->info)) { | |
445 | case BTF_KIND_TYPEDEF: | |
446 | case BTF_KIND_VOLATILE: | |
447 | case BTF_KIND_CONST: | |
448 | case BTF_KIND_RESTRICT: | |
8c42d2fa | 449 | case BTF_KIND_TYPE_TAG: |
eb3f595d MKL |
450 | return true; |
451 | } | |
452 | ||
453 | return false; | |
454 | } | |
455 | ||
2824ecb7 | 456 | bool btf_type_is_void(const struct btf_type *t) |
eb3f595d | 457 | { |
b47a0bd2 MKL |
458 | return t == &btf_void; |
459 | } | |
460 | ||
461 | static bool btf_type_is_fwd(const struct btf_type *t) | |
462 | { | |
463 | return BTF_INFO_KIND(t->info) == BTF_KIND_FWD; | |
464 | } | |
465 | ||
466 | static bool btf_type_nosize(const struct btf_type *t) | |
467 | { | |
2667a262 MKL |
468 | return btf_type_is_void(t) || btf_type_is_fwd(t) || |
469 | btf_type_is_func(t) || btf_type_is_func_proto(t); | |
eb3f595d MKL |
470 | } |
471 | ||
b47a0bd2 | 472 | static bool btf_type_nosize_or_null(const struct btf_type *t) |
eb3f595d | 473 | { |
b47a0bd2 | 474 | return !t || btf_type_nosize(t); |
eb3f595d MKL |
475 | } |
476 | ||
d83525ca AS |
477 | static bool __btf_type_is_struct(const struct btf_type *t) |
478 | { | |
479 | return BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT; | |
480 | } | |
481 | ||
eb3f595d MKL |
482 | static bool btf_type_is_array(const struct btf_type *t) |
483 | { | |
484 | return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY; | |
485 | } | |
486 | ||
1dc92851 DB |
487 | static bool btf_type_is_datasec(const struct btf_type *t) |
488 | { | |
489 | return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC; | |
490 | } | |
491 | ||
223f903e | 492 | static bool btf_type_is_decl_tag(const struct btf_type *t) |
b5ea834d | 493 | { |
223f903e | 494 | return BTF_INFO_KIND(t->info) == BTF_KIND_DECL_TAG; |
b5ea834d YS |
495 | } |
496 | ||
223f903e | 497 | static bool btf_type_is_decl_tag_target(const struct btf_type *t) |
b5ea834d YS |
498 | { |
499 | return btf_type_is_func(t) || btf_type_is_struct(t) || | |
bd16dee6 | 500 | btf_type_is_var(t) || btf_type_is_typedef(t); |
b5ea834d YS |
501 | } |
502 | ||
541c3bad | 503 | u32 btf_nr_types(const struct btf *btf) |
951bb646 AN |
504 | { |
505 | u32 total = 0; | |
506 | ||
507 | while (btf) { | |
508 | total += btf->nr_types; | |
509 | btf = btf->base_btf; | |
510 | } | |
511 | ||
512 | return total; | |
513 | } | |
514 | ||
27ae7997 MKL |
515 | s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind) |
516 | { | |
517 | const struct btf_type *t; | |
518 | const char *tname; | |
951bb646 | 519 | u32 i, total; |
27ae7997 | 520 | |
541c3bad | 521 | total = btf_nr_types(btf); |
951bb646 AN |
522 | for (i = 1; i < total; i++) { |
523 | t = btf_type_by_id(btf, i); | |
27ae7997 MKL |
524 | if (BTF_INFO_KIND(t->info) != kind) |
525 | continue; | |
526 | ||
527 | tname = btf_name_by_offset(btf, t->name_off); | |
528 | if (!strcmp(tname, name)) | |
529 | return i; | |
530 | } | |
531 | ||
532 | return -ENOENT; | |
533 | } | |
534 | ||
edc3ec09 KKD |
535 | static s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p) |
536 | { | |
537 | struct btf *btf; | |
538 | s32 ret; | |
539 | int id; | |
540 | ||
541 | btf = bpf_get_btf_vmlinux(); | |
542 | if (IS_ERR(btf)) | |
543 | return PTR_ERR(btf); | |
7ada3787 KKD |
544 | if (!btf) |
545 | return -EINVAL; | |
edc3ec09 KKD |
546 | |
547 | ret = btf_find_by_name_kind(btf, name, kind); | |
548 | /* ret is never zero, since btf_find_by_name_kind returns | |
549 | * positive btf_id or negative error. | |
550 | */ | |
551 | if (ret > 0) { | |
552 | btf_get(btf); | |
553 | *btf_p = btf; | |
554 | return ret; | |
555 | } | |
556 | ||
557 | /* If name is not found in vmlinux's BTF then search in module's BTFs */ | |
558 | spin_lock_bh(&btf_idr_lock); | |
559 | idr_for_each_entry(&btf_idr, btf, id) { | |
560 | if (!btf_is_module(btf)) | |
561 | continue; | |
562 | /* linear search could be slow hence unlock/lock | |
563 | * the IDR to avoiding holding it for too long | |
564 | */ | |
565 | btf_get(btf); | |
566 | spin_unlock_bh(&btf_idr_lock); | |
567 | ret = btf_find_by_name_kind(btf, name, kind); | |
568 | if (ret > 0) { | |
569 | *btf_p = btf; | |
570 | return ret; | |
571 | } | |
572 | spin_lock_bh(&btf_idr_lock); | |
573 | btf_put(btf); | |
574 | } | |
575 | spin_unlock_bh(&btf_idr_lock); | |
576 | return ret; | |
577 | } | |
578 | ||
27ae7997 MKL |
579 | const struct btf_type *btf_type_skip_modifiers(const struct btf *btf, |
580 | u32 id, u32 *res_id) | |
581 | { | |
582 | const struct btf_type *t = btf_type_by_id(btf, id); | |
583 | ||
584 | while (btf_type_is_modifier(t)) { | |
585 | id = t->type; | |
586 | t = btf_type_by_id(btf, t->type); | |
587 | } | |
588 | ||
589 | if (res_id) | |
590 | *res_id = id; | |
591 | ||
592 | return t; | |
593 | } | |
594 | ||
595 | const struct btf_type *btf_type_resolve_ptr(const struct btf *btf, | |
596 | u32 id, u32 *res_id) | |
597 | { | |
598 | const struct btf_type *t; | |
599 | ||
600 | t = btf_type_skip_modifiers(btf, id, NULL); | |
601 | if (!btf_type_is_ptr(t)) | |
602 | return NULL; | |
603 | ||
604 | return btf_type_skip_modifiers(btf, t->type, res_id); | |
605 | } | |
606 | ||
607 | const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf, | |
608 | u32 id, u32 *res_id) | |
609 | { | |
610 | const struct btf_type *ptype; | |
611 | ||
612 | ptype = btf_type_resolve_ptr(btf, id, res_id); | |
613 | if (ptype && btf_type_is_func_proto(ptype)) | |
614 | return ptype; | |
615 | ||
616 | return NULL; | |
617 | } | |
618 | ||
1dc92851 DB |
619 | /* Types that act only as a source, not sink or intermediate |
620 | * type when resolving. | |
621 | */ | |
622 | static bool btf_type_is_resolve_source_only(const struct btf_type *t) | |
623 | { | |
624 | return btf_type_is_var(t) || | |
223f903e | 625 | btf_type_is_decl_tag(t) || |
1dc92851 DB |
626 | btf_type_is_datasec(t); |
627 | } | |
628 | ||
eb3f595d MKL |
629 | /* What types need to be resolved? |
630 | * | |
631 | * btf_type_is_modifier() is an obvious one. | |
632 | * | |
633 | * btf_type_is_struct() because its member refers to | |
634 | * another type (through member->type). | |
1dc92851 DB |
635 | * |
636 | * btf_type_is_var() because the variable refers to | |
637 | * another type. btf_type_is_datasec() holds multiple | |
638 | * btf_type_is_var() types that need resolving. | |
639 | * | |
eb3f595d MKL |
640 | * btf_type_is_array() because its element (array->type) |
641 | * refers to another type. Array can be thought of a | |
642 | * special case of struct while array just has the same | |
643 | * member-type repeated by array->nelems of times. | |
644 | */ | |
645 | static bool btf_type_needs_resolve(const struct btf_type *t) | |
646 | { | |
647 | return btf_type_is_modifier(t) || | |
1dc92851 DB |
648 | btf_type_is_ptr(t) || |
649 | btf_type_is_struct(t) || | |
650 | btf_type_is_array(t) || | |
651 | btf_type_is_var(t) || | |
d7e7b42f | 652 | btf_type_is_func(t) || |
223f903e | 653 | btf_type_is_decl_tag(t) || |
1dc92851 | 654 | btf_type_is_datasec(t); |
eb3f595d MKL |
655 | } |
656 | ||
657 | /* t->size can be used */ | |
658 | static bool btf_type_has_size(const struct btf_type *t) | |
659 | { | |
660 | switch (BTF_INFO_KIND(t->info)) { | |
661 | case BTF_KIND_INT: | |
662 | case BTF_KIND_STRUCT: | |
663 | case BTF_KIND_UNION: | |
664 | case BTF_KIND_ENUM: | |
1dc92851 | 665 | case BTF_KIND_DATASEC: |
b1828f0b | 666 | case BTF_KIND_FLOAT: |
eb3f595d MKL |
667 | return true; |
668 | } | |
669 | ||
670 | return false; | |
671 | } | |
672 | ||
69b693f0 MKL |
673 | static const char *btf_int_encoding_str(u8 encoding) |
674 | { | |
675 | if (encoding == 0) | |
676 | return "(none)"; | |
677 | else if (encoding == BTF_INT_SIGNED) | |
678 | return "SIGNED"; | |
679 | else if (encoding == BTF_INT_CHAR) | |
680 | return "CHAR"; | |
681 | else if (encoding == BTF_INT_BOOL) | |
682 | return "BOOL"; | |
69b693f0 MKL |
683 | else |
684 | return "UNKN"; | |
685 | } | |
686 | ||
69b693f0 MKL |
687 | static u32 btf_type_int(const struct btf_type *t) |
688 | { | |
689 | return *(u32 *)(t + 1); | |
690 | } | |
691 | ||
692 | static const struct btf_array *btf_type_array(const struct btf_type *t) | |
693 | { | |
694 | return (const struct btf_array *)(t + 1); | |
695 | } | |
696 | ||
69b693f0 MKL |
697 | static const struct btf_enum *btf_type_enum(const struct btf_type *t) |
698 | { | |
699 | return (const struct btf_enum *)(t + 1); | |
700 | } | |
701 | ||
1dc92851 DB |
702 | static const struct btf_var *btf_type_var(const struct btf_type *t) |
703 | { | |
704 | return (const struct btf_var *)(t + 1); | |
705 | } | |
706 | ||
223f903e | 707 | static const struct btf_decl_tag *btf_type_decl_tag(const struct btf_type *t) |
b5ea834d | 708 | { |
223f903e | 709 | return (const struct btf_decl_tag *)(t + 1); |
b5ea834d YS |
710 | } |
711 | ||
69b693f0 MKL |
712 | static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t) |
713 | { | |
714 | return kind_ops[BTF_INFO_KIND(t->info)]; | |
715 | } | |
716 | ||
583c5318 | 717 | static bool btf_name_offset_valid(const struct btf *btf, u32 offset) |
69b693f0 | 718 | { |
951bb646 AN |
719 | if (!BTF_STR_OFFSET_VALID(offset)) |
720 | return false; | |
721 | ||
722 | while (offset < btf->start_str_off) | |
723 | btf = btf->base_btf; | |
724 | ||
725 | offset -= btf->start_str_off; | |
726 | return offset < btf->hdr.str_len; | |
69b693f0 MKL |
727 | } |
728 | ||
1dc92851 DB |
729 | static bool __btf_name_char_ok(char c, bool first, bool dot_ok) |
730 | { | |
731 | if ((first ? !isalpha(c) : | |
732 | !isalnum(c)) && | |
733 | c != '_' && | |
734 | ((c == '.' && !dot_ok) || | |
735 | c != '.')) | |
736 | return false; | |
737 | return true; | |
738 | } | |
739 | ||
951bb646 AN |
740 | static const char *btf_str_by_offset(const struct btf *btf, u32 offset) |
741 | { | |
742 | while (offset < btf->start_str_off) | |
743 | btf = btf->base_btf; | |
744 | ||
745 | offset -= btf->start_str_off; | |
746 | if (offset < btf->hdr.str_len) | |
747 | return &btf->strings[offset]; | |
748 | ||
749 | return NULL; | |
750 | } | |
751 | ||
1dc92851 | 752 | static bool __btf_name_valid(const struct btf *btf, u32 offset, bool dot_ok) |
2667a262 MKL |
753 | { |
754 | /* offset must be valid */ | |
951bb646 | 755 | const char *src = btf_str_by_offset(btf, offset); |
2667a262 MKL |
756 | const char *src_limit; |
757 | ||
1dc92851 | 758 | if (!__btf_name_char_ok(*src, true, dot_ok)) |
2667a262 MKL |
759 | return false; |
760 | ||
761 | /* set a limit on identifier length */ | |
762 | src_limit = src + KSYM_NAME_LEN; | |
763 | src++; | |
764 | while (*src && src < src_limit) { | |
1dc92851 | 765 | if (!__btf_name_char_ok(*src, false, dot_ok)) |
2667a262 MKL |
766 | return false; |
767 | src++; | |
768 | } | |
769 | ||
770 | return !*src; | |
771 | } | |
772 | ||
1dc92851 DB |
773 | /* Only C-style identifier is permitted. This can be relaxed if |
774 | * necessary. | |
775 | */ | |
776 | static bool btf_name_valid_identifier(const struct btf *btf, u32 offset) | |
777 | { | |
778 | return __btf_name_valid(btf, offset, false); | |
779 | } | |
780 | ||
781 | static bool btf_name_valid_section(const struct btf *btf, u32 offset) | |
782 | { | |
783 | return __btf_name_valid(btf, offset, true); | |
784 | } | |
785 | ||
23127b33 | 786 | static const char *__btf_name_by_offset(const struct btf *btf, u32 offset) |
69b693f0 | 787 | { |
951bb646 AN |
788 | const char *name; |
789 | ||
aea2f7b8 | 790 | if (!offset) |
69b693f0 | 791 | return "(anon)"; |
951bb646 AN |
792 | |
793 | name = btf_str_by_offset(btf, offset); | |
794 | return name ?: "(invalid-name-offset)"; | |
69b693f0 MKL |
795 | } |
796 | ||
23127b33 MKL |
797 | const char *btf_name_by_offset(const struct btf *btf, u32 offset) |
798 | { | |
951bb646 | 799 | return btf_str_by_offset(btf, offset); |
23127b33 MKL |
800 | } |
801 | ||
838e9690 | 802 | const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id) |
eb3f595d | 803 | { |
951bb646 AN |
804 | while (type_id < btf->start_id) |
805 | btf = btf->base_btf; | |
eb3f595d | 806 | |
951bb646 AN |
807 | type_id -= btf->start_id; |
808 | if (type_id >= btf->nr_types) | |
809 | return NULL; | |
eb3f595d MKL |
810 | return btf->types[type_id]; |
811 | } | |
812 | ||
4ef5f574 MKL |
813 | /* |
814 | * Regular int is not a bit field and it must be either | |
b1e8818c | 815 | * u8/u16/u32/u64 or __int128. |
4ef5f574 MKL |
816 | */ |
817 | static bool btf_type_int_is_regular(const struct btf_type *t) | |
818 | { | |
36fc3c8c | 819 | u8 nr_bits, nr_bytes; |
4ef5f574 MKL |
820 | u32 int_data; |
821 | ||
822 | int_data = btf_type_int(t); | |
823 | nr_bits = BTF_INT_BITS(int_data); | |
824 | nr_bytes = BITS_ROUNDUP_BYTES(nr_bits); | |
825 | if (BITS_PER_BYTE_MASKED(nr_bits) || | |
826 | BTF_INT_OFFSET(int_data) || | |
827 | (nr_bytes != sizeof(u8) && nr_bytes != sizeof(u16) && | |
b1e8818c YS |
828 | nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64) && |
829 | nr_bytes != (2 * sizeof(u64)))) { | |
4ef5f574 MKL |
830 | return false; |
831 | } | |
832 | ||
833 | return true; | |
834 | } | |
835 | ||
9a1126b6 | 836 | /* |
ffa0c1cf YS |
837 | * Check that given struct member is a regular int with expected |
838 | * offset and size. | |
9a1126b6 | 839 | */ |
ffa0c1cf YS |
840 | bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s, |
841 | const struct btf_member *m, | |
842 | u32 expected_offset, u32 expected_size) | |
9a1126b6 | 843 | { |
ffa0c1cf YS |
844 | const struct btf_type *t; |
845 | u32 id, int_data; | |
846 | u8 nr_bits; | |
9a1126b6 | 847 | |
ffa0c1cf YS |
848 | id = m->type; |
849 | t = btf_type_id_size(btf, &id, NULL); | |
850 | if (!t || !btf_type_is_int(t)) | |
9a1126b6 RG |
851 | return false; |
852 | ||
853 | int_data = btf_type_int(t); | |
854 | nr_bits = BTF_INT_BITS(int_data); | |
ffa0c1cf YS |
855 | if (btf_type_kflag(s)) { |
856 | u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset); | |
857 | u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset); | |
858 | ||
859 | /* if kflag set, int should be a regular int and | |
860 | * bit offset should be at byte boundary. | |
861 | */ | |
862 | return !bitfield_size && | |
863 | BITS_ROUNDUP_BYTES(bit_offset) == expected_offset && | |
864 | BITS_ROUNDUP_BYTES(nr_bits) == expected_size; | |
865 | } | |
866 | ||
867 | if (BTF_INT_OFFSET(int_data) || | |
868 | BITS_PER_BYTE_MASKED(m->offset) || | |
869 | BITS_ROUNDUP_BYTES(m->offset) != expected_offset || | |
870 | BITS_PER_BYTE_MASKED(nr_bits) || | |
871 | BITS_ROUNDUP_BYTES(nr_bits) != expected_size) | |
9a1126b6 RG |
872 | return false; |
873 | ||
874 | return true; | |
875 | } | |
876 | ||
31d0bc81 AM |
877 | /* Similar to btf_type_skip_modifiers() but does not skip typedefs. */ |
878 | static const struct btf_type *btf_type_skip_qualifiers(const struct btf *btf, | |
879 | u32 id) | |
880 | { | |
881 | const struct btf_type *t = btf_type_by_id(btf, id); | |
882 | ||
883 | while (btf_type_is_modifier(t) && | |
884 | BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF) { | |
31d0bc81 AM |
885 | t = btf_type_by_id(btf, t->type); |
886 | } | |
887 | ||
888 | return t; | |
889 | } | |
890 | ||
891 | #define BTF_SHOW_MAX_ITER 10 | |
892 | ||
893 | #define BTF_KIND_BIT(kind) (1ULL << kind) | |
894 | ||
895 | /* | |
896 | * Populate show->state.name with type name information. | |
897 | * Format of type name is | |
898 | * | |
899 | * [.member_name = ] (type_name) | |
900 | */ | |
901 | static const char *btf_show_name(struct btf_show *show) | |
902 | { | |
903 | /* BTF_MAX_ITER array suffixes "[]" */ | |
904 | const char *array_suffixes = "[][][][][][][][][][]"; | |
905 | const char *array_suffix = &array_suffixes[strlen(array_suffixes)]; | |
906 | /* BTF_MAX_ITER pointer suffixes "*" */ | |
907 | const char *ptr_suffixes = "**********"; | |
908 | const char *ptr_suffix = &ptr_suffixes[strlen(ptr_suffixes)]; | |
909 | const char *name = NULL, *prefix = "", *parens = ""; | |
910 | const struct btf_member *m = show->state.member; | |
73b6eae5 | 911 | const struct btf_type *t; |
31d0bc81 AM |
912 | const struct btf_array *array; |
913 | u32 id = show->state.type_id; | |
914 | const char *member = NULL; | |
915 | bool show_member = false; | |
916 | u64 kinds = 0; | |
917 | int i; | |
918 | ||
919 | show->state.name[0] = '\0'; | |
920 | ||
921 | /* | |
922 | * Don't show type name if we're showing an array member; | |
923 | * in that case we show the array type so don't need to repeat | |
924 | * ourselves for each member. | |
925 | */ | |
926 | if (show->state.array_member) | |
927 | return ""; | |
928 | ||
929 | /* Retrieve member name, if any. */ | |
930 | if (m) { | |
931 | member = btf_name_by_offset(show->btf, m->name_off); | |
932 | show_member = strlen(member) > 0; | |
933 | id = m->type; | |
934 | } | |
935 | ||
936 | /* | |
937 | * Start with type_id, as we have resolved the struct btf_type * | |
938 | * via btf_modifier_show() past the parent typedef to the child | |
939 | * struct, int etc it is defined as. In such cases, the type_id | |
940 | * still represents the starting type while the struct btf_type * | |
941 | * in our show->state points at the resolved type of the typedef. | |
942 | */ | |
943 | t = btf_type_by_id(show->btf, id); | |
944 | if (!t) | |
945 | return ""; | |
946 | ||
947 | /* | |
948 | * The goal here is to build up the right number of pointer and | |
949 | * array suffixes while ensuring the type name for a typedef | |
950 | * is represented. Along the way we accumulate a list of | |
951 | * BTF kinds we have encountered, since these will inform later | |
952 | * display; for example, pointer types will not require an | |
953 | * opening "{" for struct, we will just display the pointer value. | |
954 | * | |
955 | * We also want to accumulate the right number of pointer or array | |
956 | * indices in the format string while iterating until we get to | |
957 | * the typedef/pointee/array member target type. | |
958 | * | |
959 | * We start by pointing at the end of pointer and array suffix | |
960 | * strings; as we accumulate pointers and arrays we move the pointer | |
961 | * or array string backwards so it will show the expected number of | |
962 | * '*' or '[]' for the type. BTF_SHOW_MAX_ITER of nesting of pointers | |
963 | * and/or arrays and typedefs are supported as a precaution. | |
964 | * | |
965 | * We also want to get typedef name while proceeding to resolve | |
966 | * type it points to so that we can add parentheses if it is a | |
967 | * "typedef struct" etc. | |
968 | */ | |
969 | for (i = 0; i < BTF_SHOW_MAX_ITER; i++) { | |
970 | ||
971 | switch (BTF_INFO_KIND(t->info)) { | |
972 | case BTF_KIND_TYPEDEF: | |
973 | if (!name) | |
974 | name = btf_name_by_offset(show->btf, | |
975 | t->name_off); | |
976 | kinds |= BTF_KIND_BIT(BTF_KIND_TYPEDEF); | |
977 | id = t->type; | |
978 | break; | |
979 | case BTF_KIND_ARRAY: | |
980 | kinds |= BTF_KIND_BIT(BTF_KIND_ARRAY); | |
981 | parens = "["; | |
982 | if (!t) | |
983 | return ""; | |
984 | array = btf_type_array(t); | |
985 | if (array_suffix > array_suffixes) | |
986 | array_suffix -= 2; | |
987 | id = array->type; | |
988 | break; | |
989 | case BTF_KIND_PTR: | |
990 | kinds |= BTF_KIND_BIT(BTF_KIND_PTR); | |
991 | if (ptr_suffix > ptr_suffixes) | |
992 | ptr_suffix -= 1; | |
993 | id = t->type; | |
994 | break; | |
995 | default: | |
996 | id = 0; | |
997 | break; | |
998 | } | |
999 | if (!id) | |
1000 | break; | |
1001 | t = btf_type_skip_qualifiers(show->btf, id); | |
1002 | } | |
1003 | /* We may not be able to represent this type; bail to be safe */ | |
1004 | if (i == BTF_SHOW_MAX_ITER) | |
1005 | return ""; | |
1006 | ||
1007 | if (!name) | |
1008 | name = btf_name_by_offset(show->btf, t->name_off); | |
1009 | ||
1010 | switch (BTF_INFO_KIND(t->info)) { | |
1011 | case BTF_KIND_STRUCT: | |
1012 | case BTF_KIND_UNION: | |
1013 | prefix = BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT ? | |
1014 | "struct" : "union"; | |
1015 | /* if it's an array of struct/union, parens is already set */ | |
1016 | if (!(kinds & (BTF_KIND_BIT(BTF_KIND_ARRAY)))) | |
1017 | parens = "{"; | |
1018 | break; | |
1019 | case BTF_KIND_ENUM: | |
1020 | prefix = "enum"; | |
1021 | break; | |
1022 | default: | |
1023 | break; | |
1024 | } | |
1025 | ||
1026 | /* pointer does not require parens */ | |
1027 | if (kinds & BTF_KIND_BIT(BTF_KIND_PTR)) | |
1028 | parens = ""; | |
1029 | /* typedef does not require struct/union/enum prefix */ | |
1030 | if (kinds & BTF_KIND_BIT(BTF_KIND_TYPEDEF)) | |
1031 | prefix = ""; | |
1032 | ||
1033 | if (!name) | |
1034 | name = ""; | |
1035 | ||
1036 | /* Even if we don't want type name info, we want parentheses etc */ | |
1037 | if (show->flags & BTF_SHOW_NONAME) | |
1038 | snprintf(show->state.name, sizeof(show->state.name), "%s", | |
1039 | parens); | |
1040 | else | |
1041 | snprintf(show->state.name, sizeof(show->state.name), | |
1042 | "%s%s%s(%s%s%s%s%s%s)%s", | |
1043 | /* first 3 strings comprise ".member = " */ | |
1044 | show_member ? "." : "", | |
1045 | show_member ? member : "", | |
1046 | show_member ? " = " : "", | |
1047 | /* ...next is our prefix (struct, enum, etc) */ | |
1048 | prefix, | |
1049 | strlen(prefix) > 0 && strlen(name) > 0 ? " " : "", | |
1050 | /* ...this is the type name itself */ | |
1051 | name, | |
1052 | /* ...suffixed by the appropriate '*', '[]' suffixes */ | |
1053 | strlen(ptr_suffix) > 0 ? " " : "", ptr_suffix, | |
1054 | array_suffix, parens); | |
1055 | ||
1056 | return show->state.name; | |
1057 | } | |
1058 | ||
1059 | static const char *__btf_show_indent(struct btf_show *show) | |
1060 | { | |
1061 | const char *indents = " "; | |
1062 | const char *indent = &indents[strlen(indents)]; | |
1063 | ||
1064 | if ((indent - show->state.depth) >= indents) | |
1065 | return indent - show->state.depth; | |
1066 | return indents; | |
1067 | } | |
1068 | ||
1069 | static const char *btf_show_indent(struct btf_show *show) | |
1070 | { | |
1071 | return show->flags & BTF_SHOW_COMPACT ? "" : __btf_show_indent(show); | |
1072 | } | |
1073 | ||
1074 | static const char *btf_show_newline(struct btf_show *show) | |
1075 | { | |
1076 | return show->flags & BTF_SHOW_COMPACT ? "" : "\n"; | |
1077 | } | |
1078 | ||
1079 | static const char *btf_show_delim(struct btf_show *show) | |
1080 | { | |
1081 | if (show->state.depth == 0) | |
1082 | return ""; | |
1083 | ||
1084 | if ((show->flags & BTF_SHOW_COMPACT) && show->state.type && | |
1085 | BTF_INFO_KIND(show->state.type->info) == BTF_KIND_UNION) | |
1086 | return "|"; | |
1087 | ||
1088 | return ","; | |
1089 | } | |
1090 | ||
1091 | __printf(2, 3) static void btf_show(struct btf_show *show, const char *fmt, ...) | |
1092 | { | |
1093 | va_list args; | |
1094 | ||
1095 | if (!show->state.depth_check) { | |
1096 | va_start(args, fmt); | |
1097 | show->showfn(show, fmt, args); | |
1098 | va_end(args); | |
1099 | } | |
1100 | } | |
1101 | ||
1102 | /* Macros are used here as btf_show_type_value[s]() prepends and appends | |
1103 | * format specifiers to the format specifier passed in; these do the work of | |
1104 | * adding indentation, delimiters etc while the caller simply has to specify | |
1105 | * the type value(s) in the format specifier + value(s). | |
1106 | */ | |
1107 | #define btf_show_type_value(show, fmt, value) \ | |
1108 | do { \ | |
1109 | if ((value) != 0 || (show->flags & BTF_SHOW_ZERO) || \ | |
1110 | show->state.depth == 0) { \ | |
1111 | btf_show(show, "%s%s" fmt "%s%s", \ | |
1112 | btf_show_indent(show), \ | |
1113 | btf_show_name(show), \ | |
1114 | value, btf_show_delim(show), \ | |
1115 | btf_show_newline(show)); \ | |
1116 | if (show->state.depth > show->state.depth_to_show) \ | |
1117 | show->state.depth_to_show = show->state.depth; \ | |
1118 | } \ | |
1119 | } while (0) | |
1120 | ||
1121 | #define btf_show_type_values(show, fmt, ...) \ | |
1122 | do { \ | |
1123 | btf_show(show, "%s%s" fmt "%s%s", btf_show_indent(show), \ | |
1124 | btf_show_name(show), \ | |
1125 | __VA_ARGS__, btf_show_delim(show), \ | |
1126 | btf_show_newline(show)); \ | |
1127 | if (show->state.depth > show->state.depth_to_show) \ | |
1128 | show->state.depth_to_show = show->state.depth; \ | |
1129 | } while (0) | |
1130 | ||
1131 | /* How much is left to copy to safe buffer after @data? */ | |
1132 | static int btf_show_obj_size_left(struct btf_show *show, void *data) | |
1133 | { | |
1134 | return show->obj.head + show->obj.size - data; | |
1135 | } | |
1136 | ||
1137 | /* Is object pointed to by @data of @size already copied to our safe buffer? */ | |
1138 | static bool btf_show_obj_is_safe(struct btf_show *show, void *data, int size) | |
1139 | { | |
1140 | return data >= show->obj.data && | |
1141 | (data + size) < (show->obj.data + BTF_SHOW_OBJ_SAFE_SIZE); | |
1142 | } | |
1143 | ||
1144 | /* | |
1145 | * If object pointed to by @data of @size falls within our safe buffer, return | |
1146 | * the equivalent pointer to the same safe data. Assumes | |
1147 | * copy_from_kernel_nofault() has already happened and our safe buffer is | |
1148 | * populated. | |
1149 | */ | |
1150 | static void *__btf_show_obj_safe(struct btf_show *show, void *data, int size) | |
1151 | { | |
1152 | if (btf_show_obj_is_safe(show, data, size)) | |
1153 | return show->obj.safe + (data - show->obj.data); | |
1154 | return NULL; | |
1155 | } | |
1156 | ||
1157 | /* | |
1158 | * Return a safe-to-access version of data pointed to by @data. | |
1159 | * We do this by copying the relevant amount of information | |
1160 | * to the struct btf_show obj.safe buffer using copy_from_kernel_nofault(). | |
1161 | * | |
1162 | * If BTF_SHOW_UNSAFE is specified, just return data as-is; no | |
1163 | * safe copy is needed. | |
1164 | * | |
1165 | * Otherwise we need to determine if we have the required amount | |
1166 | * of data (determined by the @data pointer and the size of the | |
1167 | * largest base type we can encounter (represented by | |
1168 | * BTF_SHOW_OBJ_BASE_TYPE_SIZE). Having that much data ensures | |
1169 | * that we will be able to print some of the current object, | |
1170 | * and if more is needed a copy will be triggered. | |
1171 | * Some objects such as structs will not fit into the buffer; | |
1172 | * in such cases additional copies when we iterate over their | |
1173 | * members may be needed. | |
1174 | * | |
1175 | * btf_show_obj_safe() is used to return a safe buffer for | |
1176 | * btf_show_start_type(); this ensures that as we recurse into | |
1177 | * nested types we always have safe data for the given type. | |
1178 | * This approach is somewhat wasteful; it's possible for example | |
1179 | * that when iterating over a large union we'll end up copying the | |
1180 | * same data repeatedly, but the goal is safety not performance. | |
1181 | * We use stack data as opposed to per-CPU buffers because the | |
1182 | * iteration over a type can take some time, and preemption handling | |
1183 | * would greatly complicate use of the safe buffer. | |
1184 | */ | |
1185 | static void *btf_show_obj_safe(struct btf_show *show, | |
1186 | const struct btf_type *t, | |
1187 | void *data) | |
1188 | { | |
1189 | const struct btf_type *rt; | |
1190 | int size_left, size; | |
1191 | void *safe = NULL; | |
1192 | ||
1193 | if (show->flags & BTF_SHOW_UNSAFE) | |
1194 | return data; | |
1195 | ||
1196 | rt = btf_resolve_size(show->btf, t, &size); | |
1197 | if (IS_ERR(rt)) { | |
1198 | show->state.status = PTR_ERR(rt); | |
1199 | return NULL; | |
1200 | } | |
1201 | ||
1202 | /* | |
1203 | * Is this toplevel object? If so, set total object size and | |
1204 | * initialize pointers. Otherwise check if we still fall within | |
1205 | * our safe object data. | |
1206 | */ | |
1207 | if (show->state.depth == 0) { | |
1208 | show->obj.size = size; | |
1209 | show->obj.head = data; | |
1210 | } else { | |
1211 | /* | |
1212 | * If the size of the current object is > our remaining | |
1213 | * safe buffer we _may_ need to do a new copy. However | |
1214 | * consider the case of a nested struct; it's size pushes | |
1215 | * us over the safe buffer limit, but showing any individual | |
1216 | * struct members does not. In such cases, we don't need | |
1217 | * to initiate a fresh copy yet; however we definitely need | |
1218 | * at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes left | |
1219 | * in our buffer, regardless of the current object size. | |
1220 | * The logic here is that as we resolve types we will | |
1221 | * hit a base type at some point, and we need to be sure | |
1222 | * the next chunk of data is safely available to display | |
1223 | * that type info safely. We cannot rely on the size of | |
1224 | * the current object here because it may be much larger | |
1225 | * than our current buffer (e.g. task_struct is 8k). | |
1226 | * All we want to do here is ensure that we can print the | |
1227 | * next basic type, which we can if either | |
1228 | * - the current type size is within the safe buffer; or | |
1229 | * - at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes are left in | |
1230 | * the safe buffer. | |
1231 | */ | |
1232 | safe = __btf_show_obj_safe(show, data, | |
1233 | min(size, | |
1234 | BTF_SHOW_OBJ_BASE_TYPE_SIZE)); | |
1235 | } | |
1236 | ||
1237 | /* | |
1238 | * We need a new copy to our safe object, either because we haven't | |
8fb33b60 | 1239 | * yet copied and are initializing safe data, or because the data |
31d0bc81 AM |
1240 | * we want falls outside the boundaries of the safe object. |
1241 | */ | |
1242 | if (!safe) { | |
1243 | size_left = btf_show_obj_size_left(show, data); | |
1244 | if (size_left > BTF_SHOW_OBJ_SAFE_SIZE) | |
1245 | size_left = BTF_SHOW_OBJ_SAFE_SIZE; | |
1246 | show->state.status = copy_from_kernel_nofault(show->obj.safe, | |
1247 | data, size_left); | |
1248 | if (!show->state.status) { | |
1249 | show->obj.data = data; | |
1250 | safe = show->obj.safe; | |
1251 | } | |
1252 | } | |
1253 | ||
1254 | return safe; | |
1255 | } | |
1256 | ||
1257 | /* | |
1258 | * Set the type we are starting to show and return a safe data pointer | |
1259 | * to be used for showing the associated data. | |
1260 | */ | |
1261 | static void *btf_show_start_type(struct btf_show *show, | |
1262 | const struct btf_type *t, | |
1263 | u32 type_id, void *data) | |
1264 | { | |
1265 | show->state.type = t; | |
1266 | show->state.type_id = type_id; | |
1267 | show->state.name[0] = '\0'; | |
1268 | ||
1269 | return btf_show_obj_safe(show, t, data); | |
1270 | } | |
1271 | ||
1272 | static void btf_show_end_type(struct btf_show *show) | |
1273 | { | |
1274 | show->state.type = NULL; | |
1275 | show->state.type_id = 0; | |
1276 | show->state.name[0] = '\0'; | |
1277 | } | |
1278 | ||
1279 | static void *btf_show_start_aggr_type(struct btf_show *show, | |
1280 | const struct btf_type *t, | |
1281 | u32 type_id, void *data) | |
1282 | { | |
1283 | void *safe_data = btf_show_start_type(show, t, type_id, data); | |
1284 | ||
1285 | if (!safe_data) | |
1286 | return safe_data; | |
1287 | ||
1288 | btf_show(show, "%s%s%s", btf_show_indent(show), | |
1289 | btf_show_name(show), | |
1290 | btf_show_newline(show)); | |
1291 | show->state.depth++; | |
1292 | return safe_data; | |
1293 | } | |
1294 | ||
1295 | static void btf_show_end_aggr_type(struct btf_show *show, | |
1296 | const char *suffix) | |
1297 | { | |
1298 | show->state.depth--; | |
1299 | btf_show(show, "%s%s%s%s", btf_show_indent(show), suffix, | |
1300 | btf_show_delim(show), btf_show_newline(show)); | |
1301 | btf_show_end_type(show); | |
1302 | } | |
1303 | ||
1304 | static void btf_show_start_member(struct btf_show *show, | |
1305 | const struct btf_member *m) | |
1306 | { | |
1307 | show->state.member = m; | |
1308 | } | |
1309 | ||
1310 | static void btf_show_start_array_member(struct btf_show *show) | |
1311 | { | |
1312 | show->state.array_member = 1; | |
1313 | btf_show_start_member(show, NULL); | |
1314 | } | |
1315 | ||
1316 | static void btf_show_end_member(struct btf_show *show) | |
1317 | { | |
1318 | show->state.member = NULL; | |
1319 | } | |
1320 | ||
1321 | static void btf_show_end_array_member(struct btf_show *show) | |
1322 | { | |
1323 | show->state.array_member = 0; | |
1324 | btf_show_end_member(show); | |
1325 | } | |
1326 | ||
1327 | static void *btf_show_start_array_type(struct btf_show *show, | |
1328 | const struct btf_type *t, | |
1329 | u32 type_id, | |
1330 | u16 array_encoding, | |
1331 | void *data) | |
1332 | { | |
1333 | show->state.array_encoding = array_encoding; | |
1334 | show->state.array_terminated = 0; | |
1335 | return btf_show_start_aggr_type(show, t, type_id, data); | |
1336 | } | |
1337 | ||
1338 | static void btf_show_end_array_type(struct btf_show *show) | |
1339 | { | |
1340 | show->state.array_encoding = 0; | |
1341 | show->state.array_terminated = 0; | |
1342 | btf_show_end_aggr_type(show, "]"); | |
1343 | } | |
1344 | ||
1345 | static void *btf_show_start_struct_type(struct btf_show *show, | |
1346 | const struct btf_type *t, | |
1347 | u32 type_id, | |
1348 | void *data) | |
1349 | { | |
1350 | return btf_show_start_aggr_type(show, t, type_id, data); | |
1351 | } | |
1352 | ||
1353 | static void btf_show_end_struct_type(struct btf_show *show) | |
1354 | { | |
1355 | btf_show_end_aggr_type(show, "}"); | |
1356 | } | |
1357 | ||
69b693f0 MKL |
1358 | __printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log, |
1359 | const char *fmt, ...) | |
1360 | { | |
1361 | va_list args; | |
1362 | ||
1363 | va_start(args, fmt); | |
1364 | bpf_verifier_vlog(log, fmt, args); | |
1365 | va_end(args); | |
1366 | } | |
1367 | ||
1368 | __printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env, | |
1369 | const char *fmt, ...) | |
1370 | { | |
1371 | struct bpf_verifier_log *log = &env->log; | |
1372 | va_list args; | |
1373 | ||
1374 | if (!bpf_verifier_log_needed(log)) | |
1375 | return; | |
1376 | ||
1377 | va_start(args, fmt); | |
1378 | bpf_verifier_vlog(log, fmt, args); | |
1379 | va_end(args); | |
1380 | } | |
1381 | ||
1382 | __printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env, | |
1383 | const struct btf_type *t, | |
1384 | bool log_details, | |
1385 | const char *fmt, ...) | |
1386 | { | |
1387 | struct bpf_verifier_log *log = &env->log; | |
1388 | u8 kind = BTF_INFO_KIND(t->info); | |
1389 | struct btf *btf = env->btf; | |
1390 | va_list args; | |
1391 | ||
1392 | if (!bpf_verifier_log_needed(log)) | |
1393 | return; | |
1394 | ||
8580ac94 AS |
1395 | /* btf verifier prints all types it is processing via |
1396 | * btf_verifier_log_type(..., fmt = NULL). | |
1397 | * Skip those prints for in-kernel BTF verification. | |
1398 | */ | |
1399 | if (log->level == BPF_LOG_KERNEL && !fmt) | |
1400 | return; | |
1401 | ||
69b693f0 MKL |
1402 | __btf_verifier_log(log, "[%u] %s %s%s", |
1403 | env->log_type_id, | |
1404 | btf_kind_str[kind], | |
23127b33 | 1405 | __btf_name_by_offset(btf, t->name_off), |
69b693f0 MKL |
1406 | log_details ? " " : ""); |
1407 | ||
1408 | if (log_details) | |
1409 | btf_type_ops(t)->log_details(env, t); | |
1410 | ||
1411 | if (fmt && *fmt) { | |
1412 | __btf_verifier_log(log, " "); | |
1413 | va_start(args, fmt); | |
1414 | bpf_verifier_vlog(log, fmt, args); | |
1415 | va_end(args); | |
1416 | } | |
1417 | ||
1418 | __btf_verifier_log(log, "\n"); | |
1419 | } | |
1420 | ||
1421 | #define btf_verifier_log_type(env, t, ...) \ | |
1422 | __btf_verifier_log_type((env), (t), true, __VA_ARGS__) | |
1423 | #define btf_verifier_log_basic(env, t, ...) \ | |
1424 | __btf_verifier_log_type((env), (t), false, __VA_ARGS__) | |
1425 | ||
1426 | __printf(4, 5) | |
1427 | static void btf_verifier_log_member(struct btf_verifier_env *env, | |
1428 | const struct btf_type *struct_type, | |
1429 | const struct btf_member *member, | |
1430 | const char *fmt, ...) | |
1431 | { | |
1432 | struct bpf_verifier_log *log = &env->log; | |
1433 | struct btf *btf = env->btf; | |
1434 | va_list args; | |
1435 | ||
1436 | if (!bpf_verifier_log_needed(log)) | |
1437 | return; | |
1438 | ||
8580ac94 AS |
1439 | if (log->level == BPF_LOG_KERNEL && !fmt) |
1440 | return; | |
eb3f595d MKL |
1441 | /* The CHECK_META phase already did a btf dump. |
1442 | * | |
1443 | * If member is logged again, it must hit an error in | |
1444 | * parsing this member. It is useful to print out which | |
1445 | * struct this member belongs to. | |
1446 | */ | |
1447 | if (env->phase != CHECK_META) | |
1448 | btf_verifier_log_type(env, struct_type, NULL); | |
1449 | ||
9d5f9f70 YS |
1450 | if (btf_type_kflag(struct_type)) |
1451 | __btf_verifier_log(log, | |
1452 | "\t%s type_id=%u bitfield_size=%u bits_offset=%u", | |
1453 | __btf_name_by_offset(btf, member->name_off), | |
1454 | member->type, | |
1455 | BTF_MEMBER_BITFIELD_SIZE(member->offset), | |
1456 | BTF_MEMBER_BIT_OFFSET(member->offset)); | |
1457 | else | |
1458 | __btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u", | |
1459 | __btf_name_by_offset(btf, member->name_off), | |
1460 | member->type, member->offset); | |
69b693f0 MKL |
1461 | |
1462 | if (fmt && *fmt) { | |
1463 | __btf_verifier_log(log, " "); | |
1464 | va_start(args, fmt); | |
1465 | bpf_verifier_vlog(log, fmt, args); | |
1466 | va_end(args); | |
1467 | } | |
1468 | ||
1469 | __btf_verifier_log(log, "\n"); | |
1470 | } | |
1471 | ||
1dc92851 DB |
1472 | __printf(4, 5) |
1473 | static void btf_verifier_log_vsi(struct btf_verifier_env *env, | |
1474 | const struct btf_type *datasec_type, | |
1475 | const struct btf_var_secinfo *vsi, | |
1476 | const char *fmt, ...) | |
1477 | { | |
1478 | struct bpf_verifier_log *log = &env->log; | |
1479 | va_list args; | |
1480 | ||
1481 | if (!bpf_verifier_log_needed(log)) | |
1482 | return; | |
8580ac94 AS |
1483 | if (log->level == BPF_LOG_KERNEL && !fmt) |
1484 | return; | |
1dc92851 DB |
1485 | if (env->phase != CHECK_META) |
1486 | btf_verifier_log_type(env, datasec_type, NULL); | |
1487 | ||
1488 | __btf_verifier_log(log, "\t type_id=%u offset=%u size=%u", | |
1489 | vsi->type, vsi->offset, vsi->size); | |
1490 | if (fmt && *fmt) { | |
1491 | __btf_verifier_log(log, " "); | |
1492 | va_start(args, fmt); | |
1493 | bpf_verifier_vlog(log, fmt, args); | |
1494 | va_end(args); | |
1495 | } | |
1496 | ||
1497 | __btf_verifier_log(log, "\n"); | |
1498 | } | |
1499 | ||
f80442a4 MKL |
1500 | static void btf_verifier_log_hdr(struct btf_verifier_env *env, |
1501 | u32 btf_data_size) | |
69b693f0 MKL |
1502 | { |
1503 | struct bpf_verifier_log *log = &env->log; | |
1504 | const struct btf *btf = env->btf; | |
1505 | const struct btf_header *hdr; | |
1506 | ||
1507 | if (!bpf_verifier_log_needed(log)) | |
1508 | return; | |
1509 | ||
8580ac94 AS |
1510 | if (log->level == BPF_LOG_KERNEL) |
1511 | return; | |
f80442a4 | 1512 | hdr = &btf->hdr; |
69b693f0 MKL |
1513 | __btf_verifier_log(log, "magic: 0x%x\n", hdr->magic); |
1514 | __btf_verifier_log(log, "version: %u\n", hdr->version); | |
1515 | __btf_verifier_log(log, "flags: 0x%x\n", hdr->flags); | |
f80442a4 | 1516 | __btf_verifier_log(log, "hdr_len: %u\n", hdr->hdr_len); |
69b693f0 | 1517 | __btf_verifier_log(log, "type_off: %u\n", hdr->type_off); |
f80442a4 | 1518 | __btf_verifier_log(log, "type_len: %u\n", hdr->type_len); |
69b693f0 MKL |
1519 | __btf_verifier_log(log, "str_off: %u\n", hdr->str_off); |
1520 | __btf_verifier_log(log, "str_len: %u\n", hdr->str_len); | |
f80442a4 | 1521 | __btf_verifier_log(log, "btf_total_size: %u\n", btf_data_size); |
69b693f0 MKL |
1522 | } |
1523 | ||
1524 | static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t) | |
1525 | { | |
1526 | struct btf *btf = env->btf; | |
1527 | ||
951bb646 | 1528 | if (btf->types_size == btf->nr_types) { |
69b693f0 MKL |
1529 | /* Expand 'types' array */ |
1530 | ||
1531 | struct btf_type **new_types; | |
1532 | u32 expand_by, new_size; | |
1533 | ||
951bb646 | 1534 | if (btf->start_id + btf->types_size == BTF_MAX_TYPE) { |
69b693f0 MKL |
1535 | btf_verifier_log(env, "Exceeded max num of types"); |
1536 | return -E2BIG; | |
1537 | } | |
1538 | ||
1539 | expand_by = max_t(u32, btf->types_size >> 2, 16); | |
aea2f7b8 | 1540 | new_size = min_t(u32, BTF_MAX_TYPE, |
69b693f0 MKL |
1541 | btf->types_size + expand_by); |
1542 | ||
778e1cdd | 1543 | new_types = kvcalloc(new_size, sizeof(*new_types), |
69b693f0 MKL |
1544 | GFP_KERNEL | __GFP_NOWARN); |
1545 | if (!new_types) | |
1546 | return -ENOMEM; | |
1547 | ||
951bb646 AN |
1548 | if (btf->nr_types == 0) { |
1549 | if (!btf->base_btf) { | |
1550 | /* lazily init VOID type */ | |
1551 | new_types[0] = &btf_void; | |
1552 | btf->nr_types++; | |
1553 | } | |
1554 | } else { | |
69b693f0 | 1555 | memcpy(new_types, btf->types, |
951bb646 AN |
1556 | sizeof(*btf->types) * btf->nr_types); |
1557 | } | |
69b693f0 MKL |
1558 | |
1559 | kvfree(btf->types); | |
1560 | btf->types = new_types; | |
1561 | btf->types_size = new_size; | |
1562 | } | |
1563 | ||
951bb646 | 1564 | btf->types[btf->nr_types++] = t; |
69b693f0 MKL |
1565 | |
1566 | return 0; | |
1567 | } | |
1568 | ||
78958fca MKL |
1569 | static int btf_alloc_id(struct btf *btf) |
1570 | { | |
1571 | int id; | |
1572 | ||
1573 | idr_preload(GFP_KERNEL); | |
1574 | spin_lock_bh(&btf_idr_lock); | |
1575 | id = idr_alloc_cyclic(&btf_idr, btf, 1, INT_MAX, GFP_ATOMIC); | |
1576 | if (id > 0) | |
1577 | btf->id = id; | |
1578 | spin_unlock_bh(&btf_idr_lock); | |
1579 | idr_preload_end(); | |
1580 | ||
1581 | if (WARN_ON_ONCE(!id)) | |
1582 | return -ENOSPC; | |
1583 | ||
1584 | return id > 0 ? 0 : id; | |
1585 | } | |
1586 | ||
1587 | static void btf_free_id(struct btf *btf) | |
1588 | { | |
1589 | unsigned long flags; | |
1590 | ||
1591 | /* | |
1592 | * In map-in-map, calling map_delete_elem() on outer | |
1593 | * map will call bpf_map_put on the inner map. | |
1594 | * It will then eventually call btf_free_id() | |
1595 | * on the inner map. Some of the map_delete_elem() | |
1596 | * implementation may have irq disabled, so | |
1597 | * we need to use the _irqsave() version instead | |
1598 | * of the _bh() version. | |
1599 | */ | |
1600 | spin_lock_irqsave(&btf_idr_lock, flags); | |
1601 | idr_remove(&btf_idr, btf->id); | |
1602 | spin_unlock_irqrestore(&btf_idr_lock, flags); | |
1603 | } | |
1604 | ||
dee872e1 KKD |
1605 | static void btf_free_kfunc_set_tab(struct btf *btf) |
1606 | { | |
1607 | struct btf_kfunc_set_tab *tab = btf->kfunc_set_tab; | |
1608 | int hook, type; | |
1609 | ||
1610 | if (!tab) | |
1611 | return; | |
1612 | /* For module BTF, we directly assign the sets being registered, so | |
1613 | * there is nothing to free except kfunc_set_tab. | |
1614 | */ | |
1615 | if (btf_is_module(btf)) | |
1616 | goto free_tab; | |
1617 | for (hook = 0; hook < ARRAY_SIZE(tab->sets); hook++) { | |
1618 | for (type = 0; type < ARRAY_SIZE(tab->sets[0]); type++) | |
1619 | kfree(tab->sets[hook][type]); | |
1620 | } | |
1621 | free_tab: | |
1622 | kfree(tab); | |
1623 | btf->kfunc_set_tab = NULL; | |
1624 | } | |
1625 | ||
5ce937d6 KKD |
1626 | static void btf_free_dtor_kfunc_tab(struct btf *btf) |
1627 | { | |
1628 | struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab; | |
1629 | ||
1630 | if (!tab) | |
1631 | return; | |
1632 | kfree(tab); | |
1633 | btf->dtor_kfunc_tab = NULL; | |
1634 | } | |
1635 | ||
69b693f0 MKL |
1636 | static void btf_free(struct btf *btf) |
1637 | { | |
5ce937d6 | 1638 | btf_free_dtor_kfunc_tab(btf); |
dee872e1 | 1639 | btf_free_kfunc_set_tab(btf); |
69b693f0 | 1640 | kvfree(btf->types); |
eb3f595d MKL |
1641 | kvfree(btf->resolved_sizes); |
1642 | kvfree(btf->resolved_ids); | |
69b693f0 MKL |
1643 | kvfree(btf->data); |
1644 | kfree(btf); | |
1645 | } | |
1646 | ||
78958fca | 1647 | static void btf_free_rcu(struct rcu_head *rcu) |
f56a653c | 1648 | { |
78958fca MKL |
1649 | struct btf *btf = container_of(rcu, struct btf, rcu); |
1650 | ||
1651 | btf_free(btf); | |
f56a653c MKL |
1652 | } |
1653 | ||
22dc4a0f AN |
1654 | void btf_get(struct btf *btf) |
1655 | { | |
1656 | refcount_inc(&btf->refcnt); | |
1657 | } | |
1658 | ||
f56a653c MKL |
1659 | void btf_put(struct btf *btf) |
1660 | { | |
78958fca MKL |
1661 | if (btf && refcount_dec_and_test(&btf->refcnt)) { |
1662 | btf_free_id(btf); | |
1663 | call_rcu(&btf->rcu, btf_free_rcu); | |
1664 | } | |
f56a653c MKL |
1665 | } |
1666 | ||
eb3f595d MKL |
1667 | static int env_resolve_init(struct btf_verifier_env *env) |
1668 | { | |
1669 | struct btf *btf = env->btf; | |
1670 | u32 nr_types = btf->nr_types; | |
1671 | u32 *resolved_sizes = NULL; | |
1672 | u32 *resolved_ids = NULL; | |
1673 | u8 *visit_states = NULL; | |
1674 | ||
951bb646 | 1675 | resolved_sizes = kvcalloc(nr_types, sizeof(*resolved_sizes), |
eb3f595d MKL |
1676 | GFP_KERNEL | __GFP_NOWARN); |
1677 | if (!resolved_sizes) | |
1678 | goto nomem; | |
1679 | ||
951bb646 | 1680 | resolved_ids = kvcalloc(nr_types, sizeof(*resolved_ids), |
eb3f595d MKL |
1681 | GFP_KERNEL | __GFP_NOWARN); |
1682 | if (!resolved_ids) | |
1683 | goto nomem; | |
1684 | ||
951bb646 | 1685 | visit_states = kvcalloc(nr_types, sizeof(*visit_states), |
eb3f595d MKL |
1686 | GFP_KERNEL | __GFP_NOWARN); |
1687 | if (!visit_states) | |
1688 | goto nomem; | |
1689 | ||
1690 | btf->resolved_sizes = resolved_sizes; | |
1691 | btf->resolved_ids = resolved_ids; | |
1692 | env->visit_states = visit_states; | |
1693 | ||
1694 | return 0; | |
1695 | ||
1696 | nomem: | |
1697 | kvfree(resolved_sizes); | |
1698 | kvfree(resolved_ids); | |
1699 | kvfree(visit_states); | |
1700 | return -ENOMEM; | |
1701 | } | |
1702 | ||
69b693f0 MKL |
1703 | static void btf_verifier_env_free(struct btf_verifier_env *env) |
1704 | { | |
eb3f595d | 1705 | kvfree(env->visit_states); |
69b693f0 MKL |
1706 | kfree(env); |
1707 | } | |
1708 | ||
eb3f595d MKL |
1709 | static bool env_type_is_resolve_sink(const struct btf_verifier_env *env, |
1710 | const struct btf_type *next_type) | |
1711 | { | |
1712 | switch (env->resolve_mode) { | |
1713 | case RESOLVE_TBD: | |
1714 | /* int, enum or void is a sink */ | |
1715 | return !btf_type_needs_resolve(next_type); | |
1716 | case RESOLVE_PTR: | |
2667a262 MKL |
1717 | /* int, enum, void, struct, array, func or func_proto is a sink |
1718 | * for ptr | |
1719 | */ | |
eb3f595d MKL |
1720 | return !btf_type_is_modifier(next_type) && |
1721 | !btf_type_is_ptr(next_type); | |
1722 | case RESOLVE_STRUCT_OR_ARRAY: | |
2667a262 MKL |
1723 | /* int, enum, void, ptr, func or func_proto is a sink |
1724 | * for struct and array | |
1725 | */ | |
eb3f595d MKL |
1726 | return !btf_type_is_modifier(next_type) && |
1727 | !btf_type_is_array(next_type) && | |
1728 | !btf_type_is_struct(next_type); | |
1729 | default: | |
53c8036c | 1730 | BUG(); |
eb3f595d MKL |
1731 | } |
1732 | } | |
1733 | ||
1734 | static bool env_type_is_resolved(const struct btf_verifier_env *env, | |
1735 | u32 type_id) | |
1736 | { | |
951bb646 AN |
1737 | /* base BTF types should be resolved by now */ |
1738 | if (type_id < env->btf->start_id) | |
1739 | return true; | |
1740 | ||
1741 | return env->visit_states[type_id - env->btf->start_id] == RESOLVED; | |
eb3f595d MKL |
1742 | } |
1743 | ||
1744 | static int env_stack_push(struct btf_verifier_env *env, | |
1745 | const struct btf_type *t, u32 type_id) | |
1746 | { | |
951bb646 | 1747 | const struct btf *btf = env->btf; |
eb3f595d MKL |
1748 | struct resolve_vertex *v; |
1749 | ||
1750 | if (env->top_stack == MAX_RESOLVE_DEPTH) | |
1751 | return -E2BIG; | |
1752 | ||
951bb646 AN |
1753 | if (type_id < btf->start_id |
1754 | || env->visit_states[type_id - btf->start_id] != NOT_VISITED) | |
eb3f595d MKL |
1755 | return -EEXIST; |
1756 | ||
951bb646 | 1757 | env->visit_states[type_id - btf->start_id] = VISITED; |
eb3f595d MKL |
1758 | |
1759 | v = &env->stack[env->top_stack++]; | |
1760 | v->t = t; | |
1761 | v->type_id = type_id; | |
1762 | v->next_member = 0; | |
1763 | ||
1764 | if (env->resolve_mode == RESOLVE_TBD) { | |
1765 | if (btf_type_is_ptr(t)) | |
1766 | env->resolve_mode = RESOLVE_PTR; | |
1767 | else if (btf_type_is_struct(t) || btf_type_is_array(t)) | |
1768 | env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY; | |
1769 | } | |
1770 | ||
1771 | return 0; | |
1772 | } | |
1773 | ||
1774 | static void env_stack_set_next_member(struct btf_verifier_env *env, | |
1775 | u16 next_member) | |
1776 | { | |
1777 | env->stack[env->top_stack - 1].next_member = next_member; | |
1778 | } | |
1779 | ||
1780 | static void env_stack_pop_resolved(struct btf_verifier_env *env, | |
1781 | u32 resolved_type_id, | |
1782 | u32 resolved_size) | |
1783 | { | |
1784 | u32 type_id = env->stack[--(env->top_stack)].type_id; | |
1785 | struct btf *btf = env->btf; | |
1786 | ||
951bb646 | 1787 | type_id -= btf->start_id; /* adjust to local type id */ |
eb3f595d MKL |
1788 | btf->resolved_sizes[type_id] = resolved_size; |
1789 | btf->resolved_ids[type_id] = resolved_type_id; | |
1790 | env->visit_states[type_id] = RESOLVED; | |
1791 | } | |
1792 | ||
1793 | static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env) | |
1794 | { | |
1795 | return env->top_stack ? &env->stack[env->top_stack - 1] : NULL; | |
1796 | } | |
1797 | ||
7e3617a7 MKL |
1798 | /* Resolve the size of a passed-in "type" |
1799 | * | |
1800 | * type: is an array (e.g. u32 array[x][y]) | |
1801 | * return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY, | |
1802 | * *type_size: (x * y * sizeof(u32)). Hence, *type_size always | |
1803 | * corresponds to the return type. | |
1804 | * *elem_type: u32 | |
69ff3047 | 1805 | * *elem_id: id of u32 |
7e3617a7 MKL |
1806 | * *total_nelems: (x * y). Hence, individual elem size is |
1807 | * (*type_size / *total_nelems) | |
887c31a3 | 1808 | * *type_id: id of type if it's changed within the function, 0 if not |
7e3617a7 MKL |
1809 | * |
1810 | * type: is not an array (e.g. const struct X) | |
1811 | * return type: type "struct X" | |
1812 | * *type_size: sizeof(struct X) | |
1813 | * *elem_type: same as return type ("struct X") | |
69ff3047 | 1814 | * *elem_id: 0 |
7e3617a7 | 1815 | * *total_nelems: 1 |
887c31a3 | 1816 | * *type_id: id of type if it's changed within the function, 0 if not |
7e3617a7 | 1817 | */ |
6298399b JO |
1818 | static const struct btf_type * |
1819 | __btf_resolve_size(const struct btf *btf, const struct btf_type *type, | |
1820 | u32 *type_size, const struct btf_type **elem_type, | |
887c31a3 | 1821 | u32 *elem_id, u32 *total_nelems, u32 *type_id) |
7e3617a7 MKL |
1822 | { |
1823 | const struct btf_type *array_type = NULL; | |
69ff3047 | 1824 | const struct btf_array *array = NULL; |
887c31a3 | 1825 | u32 i, size, nelems = 1, id = 0; |
7e3617a7 MKL |
1826 | |
1827 | for (i = 0; i < MAX_RESOLVE_DEPTH; i++) { | |
1828 | switch (BTF_INFO_KIND(type->info)) { | |
1829 | /* type->size can be used */ | |
1830 | case BTF_KIND_INT: | |
1831 | case BTF_KIND_STRUCT: | |
1832 | case BTF_KIND_UNION: | |
1833 | case BTF_KIND_ENUM: | |
b1828f0b | 1834 | case BTF_KIND_FLOAT: |
7e3617a7 MKL |
1835 | size = type->size; |
1836 | goto resolved; | |
1837 | ||
1838 | case BTF_KIND_PTR: | |
1839 | size = sizeof(void *); | |
1840 | goto resolved; | |
1841 | ||
1842 | /* Modifiers */ | |
1843 | case BTF_KIND_TYPEDEF: | |
1844 | case BTF_KIND_VOLATILE: | |
1845 | case BTF_KIND_CONST: | |
1846 | case BTF_KIND_RESTRICT: | |
8c42d2fa | 1847 | case BTF_KIND_TYPE_TAG: |
887c31a3 | 1848 | id = type->type; |
7e3617a7 MKL |
1849 | type = btf_type_by_id(btf, type->type); |
1850 | break; | |
1851 | ||
1852 | case BTF_KIND_ARRAY: | |
1853 | if (!array_type) | |
1854 | array_type = type; | |
1855 | array = btf_type_array(type); | |
1856 | if (nelems && array->nelems > U32_MAX / nelems) | |
1857 | return ERR_PTR(-EINVAL); | |
1858 | nelems *= array->nelems; | |
1859 | type = btf_type_by_id(btf, array->type); | |
1860 | break; | |
1861 | ||
1862 | /* type without size */ | |
1863 | default: | |
1864 | return ERR_PTR(-EINVAL); | |
1865 | } | |
1866 | } | |
1867 | ||
1868 | return ERR_PTR(-EINVAL); | |
1869 | ||
1870 | resolved: | |
1871 | if (nelems && size > U32_MAX / nelems) | |
1872 | return ERR_PTR(-EINVAL); | |
1873 | ||
1874 | *type_size = nelems * size; | |
85d33df3 MKL |
1875 | if (total_nelems) |
1876 | *total_nelems = nelems; | |
1877 | if (elem_type) | |
1878 | *elem_type = type; | |
69ff3047 JO |
1879 | if (elem_id) |
1880 | *elem_id = array ? array->type : 0; | |
887c31a3 JO |
1881 | if (type_id && id) |
1882 | *type_id = id; | |
7e3617a7 MKL |
1883 | |
1884 | return array_type ? : type; | |
1885 | } | |
1886 | ||
6298399b JO |
1887 | const struct btf_type * |
1888 | btf_resolve_size(const struct btf *btf, const struct btf_type *type, | |
1889 | u32 *type_size) | |
1890 | { | |
887c31a3 | 1891 | return __btf_resolve_size(btf, type, type_size, NULL, NULL, NULL, NULL); |
6298399b JO |
1892 | } |
1893 | ||
951bb646 AN |
1894 | static u32 btf_resolved_type_id(const struct btf *btf, u32 type_id) |
1895 | { | |
1896 | while (type_id < btf->start_id) | |
1897 | btf = btf->base_btf; | |
1898 | ||
1899 | return btf->resolved_ids[type_id - btf->start_id]; | |
1900 | } | |
1901 | ||
eb3f595d MKL |
1902 | /* The input param "type_id" must point to a needs_resolve type */ |
1903 | static const struct btf_type *btf_type_id_resolve(const struct btf *btf, | |
1904 | u32 *type_id) | |
1905 | { | |
951bb646 | 1906 | *type_id = btf_resolved_type_id(btf, *type_id); |
eb3f595d MKL |
1907 | return btf_type_by_id(btf, *type_id); |
1908 | } | |
1909 | ||
951bb646 AN |
1910 | static u32 btf_resolved_type_size(const struct btf *btf, u32 type_id) |
1911 | { | |
1912 | while (type_id < btf->start_id) | |
1913 | btf = btf->base_btf; | |
1914 | ||
1915 | return btf->resolved_sizes[type_id - btf->start_id]; | |
1916 | } | |
1917 | ||
eb3f595d MKL |
1918 | const struct btf_type *btf_type_id_size(const struct btf *btf, |
1919 | u32 *type_id, u32 *ret_size) | |
1920 | { | |
1921 | const struct btf_type *size_type; | |
1922 | u32 size_type_id = *type_id; | |
1923 | u32 size = 0; | |
1924 | ||
1925 | size_type = btf_type_by_id(btf, size_type_id); | |
b47a0bd2 | 1926 | if (btf_type_nosize_or_null(size_type)) |
eb3f595d MKL |
1927 | return NULL; |
1928 | ||
1929 | if (btf_type_has_size(size_type)) { | |
1930 | size = size_type->size; | |
1931 | } else if (btf_type_is_array(size_type)) { | |
951bb646 | 1932 | size = btf_resolved_type_size(btf, size_type_id); |
eb3f595d MKL |
1933 | } else if (btf_type_is_ptr(size_type)) { |
1934 | size = sizeof(void *); | |
1935 | } else { | |
1dc92851 DB |
1936 | if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) && |
1937 | !btf_type_is_var(size_type))) | |
eb3f595d MKL |
1938 | return NULL; |
1939 | ||
951bb646 | 1940 | size_type_id = btf_resolved_type_id(btf, size_type_id); |
eb3f595d | 1941 | size_type = btf_type_by_id(btf, size_type_id); |
b47a0bd2 | 1942 | if (btf_type_nosize_or_null(size_type)) |
eb3f595d | 1943 | return NULL; |
1acc5d5c AN |
1944 | else if (btf_type_has_size(size_type)) |
1945 | size = size_type->size; | |
1946 | else if (btf_type_is_array(size_type)) | |
951bb646 | 1947 | size = btf_resolved_type_size(btf, size_type_id); |
1acc5d5c AN |
1948 | else if (btf_type_is_ptr(size_type)) |
1949 | size = sizeof(void *); | |
1950 | else | |
1951 | return NULL; | |
eb3f595d MKL |
1952 | } |
1953 | ||
1954 | *type_id = size_type_id; | |
1955 | if (ret_size) | |
1956 | *ret_size = size; | |
1957 | ||
1958 | return size_type; | |
1959 | } | |
1960 | ||
179cde8c MKL |
1961 | static int btf_df_check_member(struct btf_verifier_env *env, |
1962 | const struct btf_type *struct_type, | |
1963 | const struct btf_member *member, | |
1964 | const struct btf_type *member_type) | |
1965 | { | |
1966 | btf_verifier_log_basic(env, struct_type, | |
1967 | "Unsupported check_member"); | |
1968 | return -EINVAL; | |
1969 | } | |
1970 | ||
9d5f9f70 YS |
1971 | static int btf_df_check_kflag_member(struct btf_verifier_env *env, |
1972 | const struct btf_type *struct_type, | |
1973 | const struct btf_member *member, | |
1974 | const struct btf_type *member_type) | |
1975 | { | |
1976 | btf_verifier_log_basic(env, struct_type, | |
1977 | "Unsupported check_kflag_member"); | |
1978 | return -EINVAL; | |
1979 | } | |
1980 | ||
b1828f0b | 1981 | /* Used for ptr, array struct/union and float type members. |
9d5f9f70 YS |
1982 | * int, enum and modifier types have their specific callback functions. |
1983 | */ | |
1984 | static int btf_generic_check_kflag_member(struct btf_verifier_env *env, | |
1985 | const struct btf_type *struct_type, | |
1986 | const struct btf_member *member, | |
1987 | const struct btf_type *member_type) | |
1988 | { | |
1989 | if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) { | |
1990 | btf_verifier_log_member(env, struct_type, member, | |
1991 | "Invalid member bitfield_size"); | |
1992 | return -EINVAL; | |
1993 | } | |
1994 | ||
1995 | /* bitfield size is 0, so member->offset represents bit offset only. | |
1996 | * It is safe to call non kflag check_member variants. | |
1997 | */ | |
1998 | return btf_type_ops(member_type)->check_member(env, struct_type, | |
1999 | member, | |
2000 | member_type); | |
2001 | } | |
2002 | ||
eb3f595d MKL |
2003 | static int btf_df_resolve(struct btf_verifier_env *env, |
2004 | const struct resolve_vertex *v) | |
2005 | { | |
2006 | btf_verifier_log_basic(env, v->t, "Unsupported resolve"); | |
2007 | return -EINVAL; | |
2008 | } | |
2009 | ||
31d0bc81 AM |
2010 | static void btf_df_show(const struct btf *btf, const struct btf_type *t, |
2011 | u32 type_id, void *data, u8 bits_offsets, | |
2012 | struct btf_show *show) | |
b00b8dae | 2013 | { |
31d0bc81 | 2014 | btf_show(show, "<unsupported kind:%u>", BTF_INFO_KIND(t->info)); |
b00b8dae MKL |
2015 | } |
2016 | ||
179cde8c MKL |
2017 | static int btf_int_check_member(struct btf_verifier_env *env, |
2018 | const struct btf_type *struct_type, | |
2019 | const struct btf_member *member, | |
2020 | const struct btf_type *member_type) | |
2021 | { | |
2022 | u32 int_data = btf_type_int(member_type); | |
2023 | u32 struct_bits_off = member->offset; | |
2024 | u32 struct_size = struct_type->size; | |
2025 | u32 nr_copy_bits; | |
2026 | u32 bytes_offset; | |
2027 | ||
2028 | if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) { | |
2029 | btf_verifier_log_member(env, struct_type, member, | |
2030 | "bits_offset exceeds U32_MAX"); | |
2031 | return -EINVAL; | |
2032 | } | |
2033 | ||
2034 | struct_bits_off += BTF_INT_OFFSET(int_data); | |
2035 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2036 | nr_copy_bits = BTF_INT_BITS(int_data) + | |
2037 | BITS_PER_BYTE_MASKED(struct_bits_off); | |
2038 | ||
b1e8818c | 2039 | if (nr_copy_bits > BITS_PER_U128) { |
179cde8c | 2040 | btf_verifier_log_member(env, struct_type, member, |
b1e8818c | 2041 | "nr_copy_bits exceeds 128"); |
179cde8c MKL |
2042 | return -EINVAL; |
2043 | } | |
2044 | ||
2045 | if (struct_size < bytes_offset || | |
2046 | struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { | |
2047 | btf_verifier_log_member(env, struct_type, member, | |
2048 | "Member exceeds struct_size"); | |
2049 | return -EINVAL; | |
2050 | } | |
2051 | ||
2052 | return 0; | |
2053 | } | |
2054 | ||
9d5f9f70 YS |
2055 | static int btf_int_check_kflag_member(struct btf_verifier_env *env, |
2056 | const struct btf_type *struct_type, | |
2057 | const struct btf_member *member, | |
2058 | const struct btf_type *member_type) | |
2059 | { | |
2060 | u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset; | |
2061 | u32 int_data = btf_type_int(member_type); | |
2062 | u32 struct_size = struct_type->size; | |
2063 | u32 nr_copy_bits; | |
2064 | ||
2065 | /* a regular int type is required for the kflag int member */ | |
2066 | if (!btf_type_int_is_regular(member_type)) { | |
2067 | btf_verifier_log_member(env, struct_type, member, | |
2068 | "Invalid member base type"); | |
2069 | return -EINVAL; | |
2070 | } | |
2071 | ||
2072 | /* check sanity of bitfield size */ | |
2073 | nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); | |
2074 | struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); | |
2075 | nr_int_data_bits = BTF_INT_BITS(int_data); | |
2076 | if (!nr_bits) { | |
2077 | /* Not a bitfield member, member offset must be at byte | |
2078 | * boundary. | |
2079 | */ | |
2080 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2081 | btf_verifier_log_member(env, struct_type, member, | |
2082 | "Invalid member offset"); | |
2083 | return -EINVAL; | |
2084 | } | |
2085 | ||
2086 | nr_bits = nr_int_data_bits; | |
2087 | } else if (nr_bits > nr_int_data_bits) { | |
2088 | btf_verifier_log_member(env, struct_type, member, | |
2089 | "Invalid member bitfield_size"); | |
2090 | return -EINVAL; | |
2091 | } | |
2092 | ||
2093 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2094 | nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off); | |
b1e8818c | 2095 | if (nr_copy_bits > BITS_PER_U128) { |
9d5f9f70 | 2096 | btf_verifier_log_member(env, struct_type, member, |
b1e8818c | 2097 | "nr_copy_bits exceeds 128"); |
9d5f9f70 YS |
2098 | return -EINVAL; |
2099 | } | |
2100 | ||
2101 | if (struct_size < bytes_offset || | |
2102 | struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { | |
2103 | btf_verifier_log_member(env, struct_type, member, | |
2104 | "Member exceeds struct_size"); | |
2105 | return -EINVAL; | |
2106 | } | |
2107 | ||
2108 | return 0; | |
2109 | } | |
2110 | ||
69b693f0 MKL |
2111 | static s32 btf_int_check_meta(struct btf_verifier_env *env, |
2112 | const struct btf_type *t, | |
2113 | u32 meta_left) | |
2114 | { | |
2115 | u32 int_data, nr_bits, meta_needed = sizeof(int_data); | |
2116 | u16 encoding; | |
2117 | ||
2118 | if (meta_left < meta_needed) { | |
2119 | btf_verifier_log_basic(env, t, | |
2120 | "meta_left:%u meta_needed:%u", | |
2121 | meta_left, meta_needed); | |
2122 | return -EINVAL; | |
2123 | } | |
2124 | ||
2125 | if (btf_type_vlen(t)) { | |
2126 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2127 | return -EINVAL; | |
2128 | } | |
2129 | ||
9d5f9f70 YS |
2130 | if (btf_type_kflag(t)) { |
2131 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2132 | return -EINVAL; | |
2133 | } | |
2134 | ||
69b693f0 | 2135 | int_data = btf_type_int(t); |
aea2f7b8 MKL |
2136 | if (int_data & ~BTF_INT_MASK) { |
2137 | btf_verifier_log_basic(env, t, "Invalid int_data:%x", | |
2138 | int_data); | |
2139 | return -EINVAL; | |
2140 | } | |
2141 | ||
69b693f0 MKL |
2142 | nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data); |
2143 | ||
b1e8818c | 2144 | if (nr_bits > BITS_PER_U128) { |
69b693f0 | 2145 | btf_verifier_log_type(env, t, "nr_bits exceeds %zu", |
b1e8818c | 2146 | BITS_PER_U128); |
69b693f0 MKL |
2147 | return -EINVAL; |
2148 | } | |
2149 | ||
2150 | if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) { | |
2151 | btf_verifier_log_type(env, t, "nr_bits exceeds type_size"); | |
2152 | return -EINVAL; | |
2153 | } | |
2154 | ||
aea2f7b8 MKL |
2155 | /* |
2156 | * Only one of the encoding bits is allowed and it | |
2157 | * should be sufficient for the pretty print purpose (i.e. decoding). | |
2158 | * Multiple bits can be allowed later if it is found | |
2159 | * to be insufficient. | |
2160 | */ | |
69b693f0 MKL |
2161 | encoding = BTF_INT_ENCODING(int_data); |
2162 | if (encoding && | |
2163 | encoding != BTF_INT_SIGNED && | |
2164 | encoding != BTF_INT_CHAR && | |
aea2f7b8 | 2165 | encoding != BTF_INT_BOOL) { |
69b693f0 MKL |
2166 | btf_verifier_log_type(env, t, "Unsupported encoding"); |
2167 | return -ENOTSUPP; | |
2168 | } | |
2169 | ||
2170 | btf_verifier_log_type(env, t, NULL); | |
2171 | ||
2172 | return meta_needed; | |
2173 | } | |
2174 | ||
2175 | static void btf_int_log(struct btf_verifier_env *env, | |
2176 | const struct btf_type *t) | |
2177 | { | |
2178 | int int_data = btf_type_int(t); | |
2179 | ||
2180 | btf_verifier_log(env, | |
2181 | "size=%u bits_offset=%u nr_bits=%u encoding=%s", | |
2182 | t->size, BTF_INT_OFFSET(int_data), | |
2183 | BTF_INT_BITS(int_data), | |
2184 | btf_int_encoding_str(BTF_INT_ENCODING(int_data))); | |
2185 | } | |
2186 | ||
31d0bc81 | 2187 | static void btf_int128_print(struct btf_show *show, void *data) |
b1e8818c YS |
2188 | { |
2189 | /* data points to a __int128 number. | |
2190 | * Suppose | |
2191 | * int128_num = *(__int128 *)data; | |
2192 | * The below formulas shows what upper_num and lower_num represents: | |
2193 | * upper_num = int128_num >> 64; | |
2194 | * lower_num = int128_num & 0xffffffffFFFFFFFFULL; | |
2195 | */ | |
2196 | u64 upper_num, lower_num; | |
2197 | ||
2198 | #ifdef __BIG_ENDIAN_BITFIELD | |
2199 | upper_num = *(u64 *)data; | |
2200 | lower_num = *(u64 *)(data + 8); | |
2201 | #else | |
2202 | upper_num = *(u64 *)(data + 8); | |
2203 | lower_num = *(u64 *)data; | |
2204 | #endif | |
2205 | if (upper_num == 0) | |
31d0bc81 | 2206 | btf_show_type_value(show, "0x%llx", lower_num); |
b1e8818c | 2207 | else |
31d0bc81 AM |
2208 | btf_show_type_values(show, "0x%llx%016llx", upper_num, |
2209 | lower_num); | |
b1e8818c YS |
2210 | } |
2211 | ||
2212 | static void btf_int128_shift(u64 *print_num, u16 left_shift_bits, | |
2213 | u16 right_shift_bits) | |
2214 | { | |
2215 | u64 upper_num, lower_num; | |
2216 | ||
2217 | #ifdef __BIG_ENDIAN_BITFIELD | |
2218 | upper_num = print_num[0]; | |
2219 | lower_num = print_num[1]; | |
2220 | #else | |
2221 | upper_num = print_num[1]; | |
2222 | lower_num = print_num[0]; | |
2223 | #endif | |
2224 | ||
2225 | /* shake out un-needed bits by shift/or operations */ | |
2226 | if (left_shift_bits >= 64) { | |
2227 | upper_num = lower_num << (left_shift_bits - 64); | |
2228 | lower_num = 0; | |
2229 | } else { | |
2230 | upper_num = (upper_num << left_shift_bits) | | |
2231 | (lower_num >> (64 - left_shift_bits)); | |
2232 | lower_num = lower_num << left_shift_bits; | |
2233 | } | |
2234 | ||
2235 | if (right_shift_bits >= 64) { | |
2236 | lower_num = upper_num >> (right_shift_bits - 64); | |
2237 | upper_num = 0; | |
2238 | } else { | |
2239 | lower_num = (lower_num >> right_shift_bits) | | |
2240 | (upper_num << (64 - right_shift_bits)); | |
2241 | upper_num = upper_num >> right_shift_bits; | |
2242 | } | |
2243 | ||
2244 | #ifdef __BIG_ENDIAN_BITFIELD | |
2245 | print_num[0] = upper_num; | |
2246 | print_num[1] = lower_num; | |
2247 | #else | |
2248 | print_num[0] = lower_num; | |
2249 | print_num[1] = upper_num; | |
2250 | #endif | |
2251 | } | |
2252 | ||
31d0bc81 AM |
2253 | static void btf_bitfield_show(void *data, u8 bits_offset, |
2254 | u8 nr_bits, struct btf_show *show) | |
b00b8dae | 2255 | { |
b65f370d | 2256 | u16 left_shift_bits, right_shift_bits; |
36fc3c8c MKL |
2257 | u8 nr_copy_bytes; |
2258 | u8 nr_copy_bits; | |
b1e8818c | 2259 | u64 print_num[2] = {}; |
b00b8dae | 2260 | |
b00b8dae MKL |
2261 | nr_copy_bits = nr_bits + bits_offset; |
2262 | nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits); | |
2263 | ||
b1e8818c | 2264 | memcpy(print_num, data, nr_copy_bytes); |
b00b8dae | 2265 | |
b65f370d OK |
2266 | #ifdef __BIG_ENDIAN_BITFIELD |
2267 | left_shift_bits = bits_offset; | |
2268 | #else | |
b1e8818c | 2269 | left_shift_bits = BITS_PER_U128 - nr_copy_bits; |
b65f370d | 2270 | #endif |
b1e8818c | 2271 | right_shift_bits = BITS_PER_U128 - nr_bits; |
b00b8dae | 2272 | |
b1e8818c | 2273 | btf_int128_shift(print_num, left_shift_bits, right_shift_bits); |
31d0bc81 | 2274 | btf_int128_print(show, print_num); |
b00b8dae MKL |
2275 | } |
2276 | ||
9d5f9f70 | 2277 | |
31d0bc81 AM |
2278 | static void btf_int_bits_show(const struct btf *btf, |
2279 | const struct btf_type *t, | |
2280 | void *data, u8 bits_offset, | |
2281 | struct btf_show *show) | |
f97be3ab YS |
2282 | { |
2283 | u32 int_data = btf_type_int(t); | |
2284 | u8 nr_bits = BTF_INT_BITS(int_data); | |
2285 | u8 total_bits_offset; | |
2286 | ||
2287 | /* | |
2288 | * bits_offset is at most 7. | |
b1e8818c | 2289 | * BTF_INT_OFFSET() cannot exceed 128 bits. |
f97be3ab YS |
2290 | */ |
2291 | total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data); | |
17e3ac81 YS |
2292 | data += BITS_ROUNDDOWN_BYTES(total_bits_offset); |
2293 | bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset); | |
31d0bc81 | 2294 | btf_bitfield_show(data, bits_offset, nr_bits, show); |
f97be3ab YS |
2295 | } |
2296 | ||
31d0bc81 AM |
2297 | static void btf_int_show(const struct btf *btf, const struct btf_type *t, |
2298 | u32 type_id, void *data, u8 bits_offset, | |
2299 | struct btf_show *show) | |
b00b8dae MKL |
2300 | { |
2301 | u32 int_data = btf_type_int(t); | |
2302 | u8 encoding = BTF_INT_ENCODING(int_data); | |
2303 | bool sign = encoding & BTF_INT_SIGNED; | |
36fc3c8c | 2304 | u8 nr_bits = BTF_INT_BITS(int_data); |
31d0bc81 AM |
2305 | void *safe_data; |
2306 | ||
2307 | safe_data = btf_show_start_type(show, t, type_id, data); | |
2308 | if (!safe_data) | |
2309 | return; | |
b00b8dae MKL |
2310 | |
2311 | if (bits_offset || BTF_INT_OFFSET(int_data) || | |
2312 | BITS_PER_BYTE_MASKED(nr_bits)) { | |
31d0bc81 AM |
2313 | btf_int_bits_show(btf, t, safe_data, bits_offset, show); |
2314 | goto out; | |
b00b8dae MKL |
2315 | } |
2316 | ||
2317 | switch (nr_bits) { | |
b1e8818c | 2318 | case 128: |
31d0bc81 | 2319 | btf_int128_print(show, safe_data); |
b1e8818c | 2320 | break; |
b00b8dae MKL |
2321 | case 64: |
2322 | if (sign) | |
31d0bc81 | 2323 | btf_show_type_value(show, "%lld", *(s64 *)safe_data); |
b00b8dae | 2324 | else |
31d0bc81 | 2325 | btf_show_type_value(show, "%llu", *(u64 *)safe_data); |
b00b8dae MKL |
2326 | break; |
2327 | case 32: | |
2328 | if (sign) | |
31d0bc81 | 2329 | btf_show_type_value(show, "%d", *(s32 *)safe_data); |
b00b8dae | 2330 | else |
31d0bc81 | 2331 | btf_show_type_value(show, "%u", *(u32 *)safe_data); |
b00b8dae MKL |
2332 | break; |
2333 | case 16: | |
2334 | if (sign) | |
31d0bc81 | 2335 | btf_show_type_value(show, "%d", *(s16 *)safe_data); |
b00b8dae | 2336 | else |
31d0bc81 | 2337 | btf_show_type_value(show, "%u", *(u16 *)safe_data); |
b00b8dae MKL |
2338 | break; |
2339 | case 8: | |
31d0bc81 AM |
2340 | if (show->state.array_encoding == BTF_INT_CHAR) { |
2341 | /* check for null terminator */ | |
2342 | if (show->state.array_terminated) | |
2343 | break; | |
2344 | if (*(char *)data == '\0') { | |
2345 | show->state.array_terminated = 1; | |
2346 | break; | |
2347 | } | |
2348 | if (isprint(*(char *)data)) { | |
2349 | btf_show_type_value(show, "'%c'", | |
2350 | *(char *)safe_data); | |
2351 | break; | |
2352 | } | |
2353 | } | |
b00b8dae | 2354 | if (sign) |
31d0bc81 | 2355 | btf_show_type_value(show, "%d", *(s8 *)safe_data); |
b00b8dae | 2356 | else |
31d0bc81 | 2357 | btf_show_type_value(show, "%u", *(u8 *)safe_data); |
b00b8dae MKL |
2358 | break; |
2359 | default: | |
31d0bc81 AM |
2360 | btf_int_bits_show(btf, t, safe_data, bits_offset, show); |
2361 | break; | |
b00b8dae | 2362 | } |
31d0bc81 AM |
2363 | out: |
2364 | btf_show_end_type(show); | |
b00b8dae MKL |
2365 | } |
2366 | ||
69b693f0 MKL |
2367 | static const struct btf_kind_operations int_ops = { |
2368 | .check_meta = btf_int_check_meta, | |
eb3f595d | 2369 | .resolve = btf_df_resolve, |
179cde8c | 2370 | .check_member = btf_int_check_member, |
9d5f9f70 | 2371 | .check_kflag_member = btf_int_check_kflag_member, |
69b693f0 | 2372 | .log_details = btf_int_log, |
31d0bc81 | 2373 | .show = btf_int_show, |
69b693f0 MKL |
2374 | }; |
2375 | ||
179cde8c MKL |
2376 | static int btf_modifier_check_member(struct btf_verifier_env *env, |
2377 | const struct btf_type *struct_type, | |
2378 | const struct btf_member *member, | |
2379 | const struct btf_type *member_type) | |
2380 | { | |
2381 | const struct btf_type *resolved_type; | |
2382 | u32 resolved_type_id = member->type; | |
2383 | struct btf_member resolved_member; | |
2384 | struct btf *btf = env->btf; | |
2385 | ||
2386 | resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); | |
2387 | if (!resolved_type) { | |
2388 | btf_verifier_log_member(env, struct_type, member, | |
2389 | "Invalid member"); | |
2390 | return -EINVAL; | |
2391 | } | |
2392 | ||
2393 | resolved_member = *member; | |
2394 | resolved_member.type = resolved_type_id; | |
2395 | ||
2396 | return btf_type_ops(resolved_type)->check_member(env, struct_type, | |
2397 | &resolved_member, | |
2398 | resolved_type); | |
2399 | } | |
2400 | ||
9d5f9f70 YS |
2401 | static int btf_modifier_check_kflag_member(struct btf_verifier_env *env, |
2402 | const struct btf_type *struct_type, | |
2403 | const struct btf_member *member, | |
2404 | const struct btf_type *member_type) | |
2405 | { | |
2406 | const struct btf_type *resolved_type; | |
2407 | u32 resolved_type_id = member->type; | |
2408 | struct btf_member resolved_member; | |
2409 | struct btf *btf = env->btf; | |
2410 | ||
2411 | resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); | |
2412 | if (!resolved_type) { | |
2413 | btf_verifier_log_member(env, struct_type, member, | |
2414 | "Invalid member"); | |
2415 | return -EINVAL; | |
2416 | } | |
2417 | ||
2418 | resolved_member = *member; | |
2419 | resolved_member.type = resolved_type_id; | |
2420 | ||
2421 | return btf_type_ops(resolved_type)->check_kflag_member(env, struct_type, | |
2422 | &resolved_member, | |
2423 | resolved_type); | |
2424 | } | |
2425 | ||
179cde8c MKL |
2426 | static int btf_ptr_check_member(struct btf_verifier_env *env, |
2427 | const struct btf_type *struct_type, | |
2428 | const struct btf_member *member, | |
2429 | const struct btf_type *member_type) | |
2430 | { | |
2431 | u32 struct_size, struct_bits_off, bytes_offset; | |
2432 | ||
2433 | struct_size = struct_type->size; | |
2434 | struct_bits_off = member->offset; | |
2435 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2436 | ||
2437 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2438 | btf_verifier_log_member(env, struct_type, member, | |
2439 | "Member is not byte aligned"); | |
2440 | return -EINVAL; | |
2441 | } | |
2442 | ||
2443 | if (struct_size - bytes_offset < sizeof(void *)) { | |
2444 | btf_verifier_log_member(env, struct_type, member, | |
2445 | "Member exceeds struct_size"); | |
2446 | return -EINVAL; | |
2447 | } | |
2448 | ||
2449 | return 0; | |
2450 | } | |
2451 | ||
69b693f0 MKL |
2452 | static int btf_ref_type_check_meta(struct btf_verifier_env *env, |
2453 | const struct btf_type *t, | |
2454 | u32 meta_left) | |
2455 | { | |
8c42d2fa YS |
2456 | const char *value; |
2457 | ||
69b693f0 MKL |
2458 | if (btf_type_vlen(t)) { |
2459 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2460 | return -EINVAL; | |
2461 | } | |
2462 | ||
9d5f9f70 YS |
2463 | if (btf_type_kflag(t)) { |
2464 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2465 | return -EINVAL; | |
2466 | } | |
2467 | ||
aea2f7b8 | 2468 | if (!BTF_TYPE_ID_VALID(t->type)) { |
69b693f0 MKL |
2469 | btf_verifier_log_type(env, t, "Invalid type_id"); |
2470 | return -EINVAL; | |
2471 | } | |
2472 | ||
8c42d2fa | 2473 | /* typedef/type_tag type must have a valid name, and other ref types, |
eb04bbb6 YS |
2474 | * volatile, const, restrict, should have a null name. |
2475 | */ | |
2476 | if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) { | |
2477 | if (!t->name_off || | |
2478 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
2479 | btf_verifier_log_type(env, t, "Invalid name"); | |
2480 | return -EINVAL; | |
2481 | } | |
8c42d2fa YS |
2482 | } else if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPE_TAG) { |
2483 | value = btf_name_by_offset(env->btf, t->name_off); | |
2484 | if (!value || !value[0]) { | |
2485 | btf_verifier_log_type(env, t, "Invalid name"); | |
2486 | return -EINVAL; | |
2487 | } | |
eb04bbb6 YS |
2488 | } else { |
2489 | if (t->name_off) { | |
2490 | btf_verifier_log_type(env, t, "Invalid name"); | |
2491 | return -EINVAL; | |
2492 | } | |
2493 | } | |
2494 | ||
69b693f0 MKL |
2495 | btf_verifier_log_type(env, t, NULL); |
2496 | ||
2497 | return 0; | |
2498 | } | |
2499 | ||
eb3f595d MKL |
2500 | static int btf_modifier_resolve(struct btf_verifier_env *env, |
2501 | const struct resolve_vertex *v) | |
2502 | { | |
2503 | const struct btf_type *t = v->t; | |
2504 | const struct btf_type *next_type; | |
2505 | u32 next_type_id = t->type; | |
2506 | struct btf *btf = env->btf; | |
eb3f595d MKL |
2507 | |
2508 | next_type = btf_type_by_id(btf, next_type_id); | |
1dc92851 | 2509 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
eb3f595d MKL |
2510 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2511 | return -EINVAL; | |
2512 | } | |
2513 | ||
eb3f595d MKL |
2514 | if (!env_type_is_resolve_sink(env, next_type) && |
2515 | !env_type_is_resolved(env, next_type_id)) | |
2516 | return env_stack_push(env, next_type, next_type_id); | |
2517 | ||
2518 | /* Figure out the resolved next_type_id with size. | |
2519 | * They will be stored in the current modifier's | |
2520 | * resolved_ids and resolved_sizes such that it can | |
2521 | * save us a few type-following when we use it later (e.g. in | |
2522 | * pretty print). | |
2523 | */ | |
1acc5d5c | 2524 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
2667a262 MKL |
2525 | if (env_type_is_resolved(env, next_type_id)) |
2526 | next_type = btf_type_id_resolve(btf, &next_type_id); | |
2527 | ||
2528 | /* "typedef void new_void", "const void"...etc */ | |
2529 | if (!btf_type_is_void(next_type) && | |
81f5c6f5 YS |
2530 | !btf_type_is_fwd(next_type) && |
2531 | !btf_type_is_func_proto(next_type)) { | |
2667a262 MKL |
2532 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2533 | return -EINVAL; | |
2534 | } | |
eb3f595d MKL |
2535 | } |
2536 | ||
1acc5d5c | 2537 | env_stack_pop_resolved(env, next_type_id, 0); |
eb3f595d MKL |
2538 | |
2539 | return 0; | |
2540 | } | |
2541 | ||
1dc92851 DB |
2542 | static int btf_var_resolve(struct btf_verifier_env *env, |
2543 | const struct resolve_vertex *v) | |
2544 | { | |
2545 | const struct btf_type *next_type; | |
2546 | const struct btf_type *t = v->t; | |
2547 | u32 next_type_id = t->type; | |
2548 | struct btf *btf = env->btf; | |
1dc92851 DB |
2549 | |
2550 | next_type = btf_type_by_id(btf, next_type_id); | |
2551 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { | |
2552 | btf_verifier_log_type(env, v->t, "Invalid type_id"); | |
2553 | return -EINVAL; | |
2554 | } | |
2555 | ||
2556 | if (!env_type_is_resolve_sink(env, next_type) && | |
2557 | !env_type_is_resolved(env, next_type_id)) | |
2558 | return env_stack_push(env, next_type, next_type_id); | |
2559 | ||
2560 | if (btf_type_is_modifier(next_type)) { | |
2561 | const struct btf_type *resolved_type; | |
2562 | u32 resolved_type_id; | |
2563 | ||
2564 | resolved_type_id = next_type_id; | |
2565 | resolved_type = btf_type_id_resolve(btf, &resolved_type_id); | |
2566 | ||
2567 | if (btf_type_is_ptr(resolved_type) && | |
2568 | !env_type_is_resolve_sink(env, resolved_type) && | |
2569 | !env_type_is_resolved(env, resolved_type_id)) | |
2570 | return env_stack_push(env, resolved_type, | |
2571 | resolved_type_id); | |
2572 | } | |
2573 | ||
2574 | /* We must resolve to something concrete at this point, no | |
2575 | * forward types or similar that would resolve to size of | |
2576 | * zero is allowed. | |
2577 | */ | |
1acc5d5c | 2578 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
1dc92851 DB |
2579 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2580 | return -EINVAL; | |
2581 | } | |
2582 | ||
1acc5d5c | 2583 | env_stack_pop_resolved(env, next_type_id, 0); |
1dc92851 DB |
2584 | |
2585 | return 0; | |
2586 | } | |
2587 | ||
eb3f595d MKL |
2588 | static int btf_ptr_resolve(struct btf_verifier_env *env, |
2589 | const struct resolve_vertex *v) | |
2590 | { | |
2591 | const struct btf_type *next_type; | |
2592 | const struct btf_type *t = v->t; | |
2593 | u32 next_type_id = t->type; | |
2594 | struct btf *btf = env->btf; | |
eb3f595d MKL |
2595 | |
2596 | next_type = btf_type_by_id(btf, next_type_id); | |
1dc92851 | 2597 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
eb3f595d MKL |
2598 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2599 | return -EINVAL; | |
2600 | } | |
2601 | ||
eb3f595d MKL |
2602 | if (!env_type_is_resolve_sink(env, next_type) && |
2603 | !env_type_is_resolved(env, next_type_id)) | |
2604 | return env_stack_push(env, next_type, next_type_id); | |
2605 | ||
2606 | /* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY, | |
2607 | * the modifier may have stopped resolving when it was resolved | |
2608 | * to a ptr (last-resolved-ptr). | |
2609 | * | |
2610 | * We now need to continue from the last-resolved-ptr to | |
2611 | * ensure the last-resolved-ptr will not referring back to | |
c561d110 | 2612 | * the current ptr (t). |
eb3f595d MKL |
2613 | */ |
2614 | if (btf_type_is_modifier(next_type)) { | |
2615 | const struct btf_type *resolved_type; | |
2616 | u32 resolved_type_id; | |
2617 | ||
2618 | resolved_type_id = next_type_id; | |
2619 | resolved_type = btf_type_id_resolve(btf, &resolved_type_id); | |
2620 | ||
2621 | if (btf_type_is_ptr(resolved_type) && | |
2622 | !env_type_is_resolve_sink(env, resolved_type) && | |
2623 | !env_type_is_resolved(env, resolved_type_id)) | |
2624 | return env_stack_push(env, resolved_type, | |
2625 | resolved_type_id); | |
2626 | } | |
2627 | ||
2667a262 MKL |
2628 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
2629 | if (env_type_is_resolved(env, next_type_id)) | |
2630 | next_type = btf_type_id_resolve(btf, &next_type_id); | |
2631 | ||
2632 | if (!btf_type_is_void(next_type) && | |
2633 | !btf_type_is_fwd(next_type) && | |
2634 | !btf_type_is_func_proto(next_type)) { | |
2635 | btf_verifier_log_type(env, v->t, "Invalid type_id"); | |
2636 | return -EINVAL; | |
2637 | } | |
eb3f595d MKL |
2638 | } |
2639 | ||
eb3f595d MKL |
2640 | env_stack_pop_resolved(env, next_type_id, 0); |
2641 | ||
2642 | return 0; | |
2643 | } | |
2644 | ||
31d0bc81 AM |
2645 | static void btf_modifier_show(const struct btf *btf, |
2646 | const struct btf_type *t, | |
2647 | u32 type_id, void *data, | |
2648 | u8 bits_offset, struct btf_show *show) | |
b00b8dae | 2649 | { |
85d33df3 MKL |
2650 | if (btf->resolved_ids) |
2651 | t = btf_type_id_resolve(btf, &type_id); | |
2652 | else | |
2653 | t = btf_type_skip_modifiers(btf, type_id, NULL); | |
b00b8dae | 2654 | |
31d0bc81 | 2655 | btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show); |
b00b8dae MKL |
2656 | } |
2657 | ||
31d0bc81 AM |
2658 | static void btf_var_show(const struct btf *btf, const struct btf_type *t, |
2659 | u32 type_id, void *data, u8 bits_offset, | |
2660 | struct btf_show *show) | |
1dc92851 DB |
2661 | { |
2662 | t = btf_type_id_resolve(btf, &type_id); | |
2663 | ||
31d0bc81 | 2664 | btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show); |
1dc92851 DB |
2665 | } |
2666 | ||
31d0bc81 AM |
2667 | static void btf_ptr_show(const struct btf *btf, const struct btf_type *t, |
2668 | u32 type_id, void *data, u8 bits_offset, | |
2669 | struct btf_show *show) | |
b00b8dae | 2670 | { |
31d0bc81 AM |
2671 | void *safe_data; |
2672 | ||
2673 | safe_data = btf_show_start_type(show, t, type_id, data); | |
2674 | if (!safe_data) | |
2675 | return; | |
2676 | ||
2677 | /* It is a hashed value unless BTF_SHOW_PTR_RAW is specified */ | |
2678 | if (show->flags & BTF_SHOW_PTR_RAW) | |
2679 | btf_show_type_value(show, "0x%px", *(void **)safe_data); | |
2680 | else | |
2681 | btf_show_type_value(show, "0x%p", *(void **)safe_data); | |
2682 | btf_show_end_type(show); | |
b00b8dae MKL |
2683 | } |
2684 | ||
69b693f0 MKL |
2685 | static void btf_ref_type_log(struct btf_verifier_env *env, |
2686 | const struct btf_type *t) | |
2687 | { | |
2688 | btf_verifier_log(env, "type_id=%u", t->type); | |
2689 | } | |
2690 | ||
2691 | static struct btf_kind_operations modifier_ops = { | |
2692 | .check_meta = btf_ref_type_check_meta, | |
eb3f595d | 2693 | .resolve = btf_modifier_resolve, |
179cde8c | 2694 | .check_member = btf_modifier_check_member, |
9d5f9f70 | 2695 | .check_kflag_member = btf_modifier_check_kflag_member, |
69b693f0 | 2696 | .log_details = btf_ref_type_log, |
31d0bc81 | 2697 | .show = btf_modifier_show, |
69b693f0 MKL |
2698 | }; |
2699 | ||
2700 | static struct btf_kind_operations ptr_ops = { | |
2701 | .check_meta = btf_ref_type_check_meta, | |
eb3f595d | 2702 | .resolve = btf_ptr_resolve, |
179cde8c | 2703 | .check_member = btf_ptr_check_member, |
9d5f9f70 | 2704 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 2705 | .log_details = btf_ref_type_log, |
31d0bc81 | 2706 | .show = btf_ptr_show, |
69b693f0 MKL |
2707 | }; |
2708 | ||
8175383f MKL |
2709 | static s32 btf_fwd_check_meta(struct btf_verifier_env *env, |
2710 | const struct btf_type *t, | |
2711 | u32 meta_left) | |
2712 | { | |
2713 | if (btf_type_vlen(t)) { | |
2714 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2715 | return -EINVAL; | |
2716 | } | |
2717 | ||
2718 | if (t->type) { | |
2719 | btf_verifier_log_type(env, t, "type != 0"); | |
2720 | return -EINVAL; | |
2721 | } | |
2722 | ||
eb04bbb6 YS |
2723 | /* fwd type must have a valid name */ |
2724 | if (!t->name_off || | |
2725 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
2726 | btf_verifier_log_type(env, t, "Invalid name"); | |
2727 | return -EINVAL; | |
2728 | } | |
2729 | ||
8175383f MKL |
2730 | btf_verifier_log_type(env, t, NULL); |
2731 | ||
2732 | return 0; | |
2733 | } | |
2734 | ||
76c43ae8 YS |
2735 | static void btf_fwd_type_log(struct btf_verifier_env *env, |
2736 | const struct btf_type *t) | |
2737 | { | |
2738 | btf_verifier_log(env, "%s", btf_type_kflag(t) ? "union" : "struct"); | |
2739 | } | |
2740 | ||
69b693f0 | 2741 | static struct btf_kind_operations fwd_ops = { |
8175383f | 2742 | .check_meta = btf_fwd_check_meta, |
eb3f595d | 2743 | .resolve = btf_df_resolve, |
179cde8c | 2744 | .check_member = btf_df_check_member, |
9d5f9f70 | 2745 | .check_kflag_member = btf_df_check_kflag_member, |
76c43ae8 | 2746 | .log_details = btf_fwd_type_log, |
31d0bc81 | 2747 | .show = btf_df_show, |
69b693f0 MKL |
2748 | }; |
2749 | ||
179cde8c MKL |
2750 | static int btf_array_check_member(struct btf_verifier_env *env, |
2751 | const struct btf_type *struct_type, | |
2752 | const struct btf_member *member, | |
2753 | const struct btf_type *member_type) | |
2754 | { | |
2755 | u32 struct_bits_off = member->offset; | |
2756 | u32 struct_size, bytes_offset; | |
2757 | u32 array_type_id, array_size; | |
2758 | struct btf *btf = env->btf; | |
2759 | ||
2760 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2761 | btf_verifier_log_member(env, struct_type, member, | |
2762 | "Member is not byte aligned"); | |
2763 | return -EINVAL; | |
2764 | } | |
2765 | ||
2766 | array_type_id = member->type; | |
2767 | btf_type_id_size(btf, &array_type_id, &array_size); | |
2768 | struct_size = struct_type->size; | |
2769 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2770 | if (struct_size - bytes_offset < array_size) { | |
2771 | btf_verifier_log_member(env, struct_type, member, | |
2772 | "Member exceeds struct_size"); | |
2773 | return -EINVAL; | |
2774 | } | |
2775 | ||
2776 | return 0; | |
2777 | } | |
2778 | ||
69b693f0 MKL |
2779 | static s32 btf_array_check_meta(struct btf_verifier_env *env, |
2780 | const struct btf_type *t, | |
2781 | u32 meta_left) | |
2782 | { | |
2783 | const struct btf_array *array = btf_type_array(t); | |
2784 | u32 meta_needed = sizeof(*array); | |
2785 | ||
2786 | if (meta_left < meta_needed) { | |
2787 | btf_verifier_log_basic(env, t, | |
2788 | "meta_left:%u meta_needed:%u", | |
2789 | meta_left, meta_needed); | |
2790 | return -EINVAL; | |
2791 | } | |
2792 | ||
eb04bbb6 YS |
2793 | /* array type should not have a name */ |
2794 | if (t->name_off) { | |
2795 | btf_verifier_log_type(env, t, "Invalid name"); | |
2796 | return -EINVAL; | |
2797 | } | |
2798 | ||
69b693f0 MKL |
2799 | if (btf_type_vlen(t)) { |
2800 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2801 | return -EINVAL; | |
2802 | } | |
2803 | ||
9d5f9f70 YS |
2804 | if (btf_type_kflag(t)) { |
2805 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2806 | return -EINVAL; | |
2807 | } | |
2808 | ||
b9308ae6 MKL |
2809 | if (t->size) { |
2810 | btf_verifier_log_type(env, t, "size != 0"); | |
2811 | return -EINVAL; | |
2812 | } | |
2813 | ||
4ef5f574 MKL |
2814 | /* Array elem type and index type cannot be in type void, |
2815 | * so !array->type and !array->index_type are not allowed. | |
69b693f0 | 2816 | */ |
aea2f7b8 | 2817 | if (!array->type || !BTF_TYPE_ID_VALID(array->type)) { |
4ef5f574 MKL |
2818 | btf_verifier_log_type(env, t, "Invalid elem"); |
2819 | return -EINVAL; | |
2820 | } | |
2821 | ||
aea2f7b8 | 2822 | if (!array->index_type || !BTF_TYPE_ID_VALID(array->index_type)) { |
4ef5f574 | 2823 | btf_verifier_log_type(env, t, "Invalid index"); |
69b693f0 MKL |
2824 | return -EINVAL; |
2825 | } | |
2826 | ||
2827 | btf_verifier_log_type(env, t, NULL); | |
2828 | ||
2829 | return meta_needed; | |
2830 | } | |
2831 | ||
eb3f595d MKL |
2832 | static int btf_array_resolve(struct btf_verifier_env *env, |
2833 | const struct resolve_vertex *v) | |
2834 | { | |
2835 | const struct btf_array *array = btf_type_array(v->t); | |
4ef5f574 MKL |
2836 | const struct btf_type *elem_type, *index_type; |
2837 | u32 elem_type_id, index_type_id; | |
eb3f595d MKL |
2838 | struct btf *btf = env->btf; |
2839 | u32 elem_size; | |
2840 | ||
4ef5f574 MKL |
2841 | /* Check array->index_type */ |
2842 | index_type_id = array->index_type; | |
2843 | index_type = btf_type_by_id(btf, index_type_id); | |
e4f07120 SF |
2844 | if (btf_type_nosize_or_null(index_type) || |
2845 | btf_type_is_resolve_source_only(index_type)) { | |
4ef5f574 MKL |
2846 | btf_verifier_log_type(env, v->t, "Invalid index"); |
2847 | return -EINVAL; | |
2848 | } | |
2849 | ||
2850 | if (!env_type_is_resolve_sink(env, index_type) && | |
2851 | !env_type_is_resolved(env, index_type_id)) | |
2852 | return env_stack_push(env, index_type, index_type_id); | |
2853 | ||
2854 | index_type = btf_type_id_size(btf, &index_type_id, NULL); | |
2855 | if (!index_type || !btf_type_is_int(index_type) || | |
2856 | !btf_type_int_is_regular(index_type)) { | |
2857 | btf_verifier_log_type(env, v->t, "Invalid index"); | |
2858 | return -EINVAL; | |
2859 | } | |
2860 | ||
2861 | /* Check array->type */ | |
2862 | elem_type_id = array->type; | |
eb3f595d | 2863 | elem_type = btf_type_by_id(btf, elem_type_id); |
e4f07120 SF |
2864 | if (btf_type_nosize_or_null(elem_type) || |
2865 | btf_type_is_resolve_source_only(elem_type)) { | |
eb3f595d MKL |
2866 | btf_verifier_log_type(env, v->t, |
2867 | "Invalid elem"); | |
2868 | return -EINVAL; | |
2869 | } | |
2870 | ||
2871 | if (!env_type_is_resolve_sink(env, elem_type) && | |
2872 | !env_type_is_resolved(env, elem_type_id)) | |
2873 | return env_stack_push(env, elem_type, elem_type_id); | |
2874 | ||
2875 | elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); | |
2876 | if (!elem_type) { | |
2877 | btf_verifier_log_type(env, v->t, "Invalid elem"); | |
2878 | return -EINVAL; | |
2879 | } | |
2880 | ||
4ef5f574 MKL |
2881 | if (btf_type_is_int(elem_type) && !btf_type_int_is_regular(elem_type)) { |
2882 | btf_verifier_log_type(env, v->t, "Invalid array of int"); | |
2883 | return -EINVAL; | |
eb3f595d MKL |
2884 | } |
2885 | ||
2886 | if (array->nelems && elem_size > U32_MAX / array->nelems) { | |
2887 | btf_verifier_log_type(env, v->t, | |
2888 | "Array size overflows U32_MAX"); | |
2889 | return -EINVAL; | |
2890 | } | |
2891 | ||
2892 | env_stack_pop_resolved(env, elem_type_id, elem_size * array->nelems); | |
2893 | ||
2894 | return 0; | |
2895 | } | |
2896 | ||
69b693f0 MKL |
2897 | static void btf_array_log(struct btf_verifier_env *env, |
2898 | const struct btf_type *t) | |
2899 | { | |
2900 | const struct btf_array *array = btf_type_array(t); | |
2901 | ||
2902 | btf_verifier_log(env, "type_id=%u index_type_id=%u nr_elems=%u", | |
2903 | array->type, array->index_type, array->nelems); | |
2904 | } | |
2905 | ||
31d0bc81 AM |
2906 | static void __btf_array_show(const struct btf *btf, const struct btf_type *t, |
2907 | u32 type_id, void *data, u8 bits_offset, | |
2908 | struct btf_show *show) | |
b00b8dae MKL |
2909 | { |
2910 | const struct btf_array *array = btf_type_array(t); | |
2911 | const struct btf_kind_operations *elem_ops; | |
2912 | const struct btf_type *elem_type; | |
31d0bc81 AM |
2913 | u32 i, elem_size = 0, elem_type_id; |
2914 | u16 encoding = 0; | |
b00b8dae MKL |
2915 | |
2916 | elem_type_id = array->type; | |
31d0bc81 AM |
2917 | elem_type = btf_type_skip_modifiers(btf, elem_type_id, NULL); |
2918 | if (elem_type && btf_type_has_size(elem_type)) | |
2919 | elem_size = elem_type->size; | |
2920 | ||
2921 | if (elem_type && btf_type_is_int(elem_type)) { | |
2922 | u32 int_type = btf_type_int(elem_type); | |
2923 | ||
2924 | encoding = BTF_INT_ENCODING(int_type); | |
2925 | ||
2926 | /* | |
2927 | * BTF_INT_CHAR encoding never seems to be set for | |
2928 | * char arrays, so if size is 1 and element is | |
2929 | * printable as a char, we'll do that. | |
2930 | */ | |
2931 | if (elem_size == 1) | |
2932 | encoding = BTF_INT_CHAR; | |
2933 | } | |
2934 | ||
2935 | if (!btf_show_start_array_type(show, t, type_id, encoding, data)) | |
2936 | return; | |
2937 | ||
2938 | if (!elem_type) | |
2939 | goto out; | |
b00b8dae | 2940 | elem_ops = btf_type_ops(elem_type); |
31d0bc81 | 2941 | |
b00b8dae | 2942 | for (i = 0; i < array->nelems; i++) { |
b00b8dae | 2943 | |
31d0bc81 AM |
2944 | btf_show_start_array_member(show); |
2945 | ||
2946 | elem_ops->show(btf, elem_type, elem_type_id, data, | |
2947 | bits_offset, show); | |
b00b8dae | 2948 | data += elem_size; |
31d0bc81 AM |
2949 | |
2950 | btf_show_end_array_member(show); | |
2951 | ||
2952 | if (show->state.array_terminated) | |
2953 | break; | |
b00b8dae | 2954 | } |
31d0bc81 AM |
2955 | out: |
2956 | btf_show_end_array_type(show); | |
2957 | } | |
2958 | ||
2959 | static void btf_array_show(const struct btf *btf, const struct btf_type *t, | |
2960 | u32 type_id, void *data, u8 bits_offset, | |
2961 | struct btf_show *show) | |
2962 | { | |
2963 | const struct btf_member *m = show->state.member; | |
2964 | ||
2965 | /* | |
2966 | * First check if any members would be shown (are non-zero). | |
2967 | * See comments above "struct btf_show" definition for more | |
2968 | * details on how this works at a high-level. | |
2969 | */ | |
2970 | if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) { | |
2971 | if (!show->state.depth_check) { | |
2972 | show->state.depth_check = show->state.depth + 1; | |
2973 | show->state.depth_to_show = 0; | |
2974 | } | |
2975 | __btf_array_show(btf, t, type_id, data, bits_offset, show); | |
2976 | show->state.member = m; | |
2977 | ||
2978 | if (show->state.depth_check != show->state.depth + 1) | |
2979 | return; | |
2980 | show->state.depth_check = 0; | |
2981 | ||
2982 | if (show->state.depth_to_show <= show->state.depth) | |
2983 | return; | |
2984 | /* | |
2985 | * Reaching here indicates we have recursed and found | |
2986 | * non-zero array member(s). | |
2987 | */ | |
2988 | } | |
2989 | __btf_array_show(btf, t, type_id, data, bits_offset, show); | |
b00b8dae MKL |
2990 | } |
2991 | ||
69b693f0 MKL |
2992 | static struct btf_kind_operations array_ops = { |
2993 | .check_meta = btf_array_check_meta, | |
eb3f595d | 2994 | .resolve = btf_array_resolve, |
179cde8c | 2995 | .check_member = btf_array_check_member, |
9d5f9f70 | 2996 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 2997 | .log_details = btf_array_log, |
31d0bc81 | 2998 | .show = btf_array_show, |
69b693f0 MKL |
2999 | }; |
3000 | ||
179cde8c MKL |
3001 | static int btf_struct_check_member(struct btf_verifier_env *env, |
3002 | const struct btf_type *struct_type, | |
3003 | const struct btf_member *member, | |
3004 | const struct btf_type *member_type) | |
3005 | { | |
3006 | u32 struct_bits_off = member->offset; | |
3007 | u32 struct_size, bytes_offset; | |
3008 | ||
3009 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
3010 | btf_verifier_log_member(env, struct_type, member, | |
3011 | "Member is not byte aligned"); | |
3012 | return -EINVAL; | |
3013 | } | |
3014 | ||
3015 | struct_size = struct_type->size; | |
3016 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
3017 | if (struct_size - bytes_offset < member_type->size) { | |
3018 | btf_verifier_log_member(env, struct_type, member, | |
3019 | "Member exceeds struct_size"); | |
3020 | return -EINVAL; | |
3021 | } | |
3022 | ||
3023 | return 0; | |
3024 | } | |
3025 | ||
69b693f0 MKL |
3026 | static s32 btf_struct_check_meta(struct btf_verifier_env *env, |
3027 | const struct btf_type *t, | |
3028 | u32 meta_left) | |
3029 | { | |
3030 | bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION; | |
3031 | const struct btf_member *member; | |
6283fa38 | 3032 | u32 meta_needed, last_offset; |
69b693f0 MKL |
3033 | struct btf *btf = env->btf; |
3034 | u32 struct_size = t->size; | |
9d5f9f70 | 3035 | u32 offset; |
69b693f0 MKL |
3036 | u16 i; |
3037 | ||
3038 | meta_needed = btf_type_vlen(t) * sizeof(*member); | |
3039 | if (meta_left < meta_needed) { | |
3040 | btf_verifier_log_basic(env, t, | |
3041 | "meta_left:%u meta_needed:%u", | |
3042 | meta_left, meta_needed); | |
3043 | return -EINVAL; | |
3044 | } | |
3045 | ||
eb04bbb6 YS |
3046 | /* struct type either no name or a valid one */ |
3047 | if (t->name_off && | |
3048 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
3049 | btf_verifier_log_type(env, t, "Invalid name"); | |
3050 | return -EINVAL; | |
3051 | } | |
3052 | ||
69b693f0 MKL |
3053 | btf_verifier_log_type(env, t, NULL); |
3054 | ||
6283fa38 | 3055 | last_offset = 0; |
69b693f0 | 3056 | for_each_member(i, t, member) { |
fbcf93eb | 3057 | if (!btf_name_offset_valid(btf, member->name_off)) { |
69b693f0 MKL |
3058 | btf_verifier_log_member(env, t, member, |
3059 | "Invalid member name_offset:%u", | |
fbcf93eb | 3060 | member->name_off); |
69b693f0 MKL |
3061 | return -EINVAL; |
3062 | } | |
3063 | ||
eb04bbb6 YS |
3064 | /* struct member either no name or a valid one */ |
3065 | if (member->name_off && | |
3066 | !btf_name_valid_identifier(btf, member->name_off)) { | |
3067 | btf_verifier_log_member(env, t, member, "Invalid name"); | |
3068 | return -EINVAL; | |
3069 | } | |
69b693f0 | 3070 | /* A member cannot be in type void */ |
aea2f7b8 | 3071 | if (!member->type || !BTF_TYPE_ID_VALID(member->type)) { |
69b693f0 MKL |
3072 | btf_verifier_log_member(env, t, member, |
3073 | "Invalid type_id"); | |
3074 | return -EINVAL; | |
3075 | } | |
3076 | ||
8293eb99 | 3077 | offset = __btf_member_bit_offset(t, member); |
9d5f9f70 | 3078 | if (is_union && offset) { |
69b693f0 MKL |
3079 | btf_verifier_log_member(env, t, member, |
3080 | "Invalid member bits_offset"); | |
3081 | return -EINVAL; | |
3082 | } | |
3083 | ||
6283fa38 MKL |
3084 | /* |
3085 | * ">" instead of ">=" because the last member could be | |
3086 | * "char a[0];" | |
3087 | */ | |
9d5f9f70 | 3088 | if (last_offset > offset) { |
6283fa38 MKL |
3089 | btf_verifier_log_member(env, t, member, |
3090 | "Invalid member bits_offset"); | |
3091 | return -EINVAL; | |
3092 | } | |
3093 | ||
9d5f9f70 | 3094 | if (BITS_ROUNDUP_BYTES(offset) > struct_size) { |
69b693f0 | 3095 | btf_verifier_log_member(env, t, member, |
311fe1a8 | 3096 | "Member bits_offset exceeds its struct size"); |
69b693f0 MKL |
3097 | return -EINVAL; |
3098 | } | |
3099 | ||
3100 | btf_verifier_log_member(env, t, member, NULL); | |
9d5f9f70 | 3101 | last_offset = offset; |
69b693f0 MKL |
3102 | } |
3103 | ||
3104 | return meta_needed; | |
3105 | } | |
3106 | ||
eb3f595d MKL |
3107 | static int btf_struct_resolve(struct btf_verifier_env *env, |
3108 | const struct resolve_vertex *v) | |
3109 | { | |
3110 | const struct btf_member *member; | |
179cde8c | 3111 | int err; |
eb3f595d MKL |
3112 | u16 i; |
3113 | ||
3114 | /* Before continue resolving the next_member, | |
3115 | * ensure the last member is indeed resolved to a | |
3116 | * type with size info. | |
3117 | */ | |
3118 | if (v->next_member) { | |
179cde8c | 3119 | const struct btf_type *last_member_type; |
eb3f595d MKL |
3120 | const struct btf_member *last_member; |
3121 | u16 last_member_type_id; | |
3122 | ||
3123 | last_member = btf_type_member(v->t) + v->next_member - 1; | |
3124 | last_member_type_id = last_member->type; | |
3125 | if (WARN_ON_ONCE(!env_type_is_resolved(env, | |
3126 | last_member_type_id))) | |
3127 | return -EINVAL; | |
179cde8c MKL |
3128 | |
3129 | last_member_type = btf_type_by_id(env->btf, | |
3130 | last_member_type_id); | |
9d5f9f70 YS |
3131 | if (btf_type_kflag(v->t)) |
3132 | err = btf_type_ops(last_member_type)->check_kflag_member(env, v->t, | |
3133 | last_member, | |
3134 | last_member_type); | |
3135 | else | |
3136 | err = btf_type_ops(last_member_type)->check_member(env, v->t, | |
3137 | last_member, | |
3138 | last_member_type); | |
179cde8c MKL |
3139 | if (err) |
3140 | return err; | |
eb3f595d MKL |
3141 | } |
3142 | ||
3143 | for_each_member_from(i, v->next_member, v->t, member) { | |
3144 | u32 member_type_id = member->type; | |
3145 | const struct btf_type *member_type = btf_type_by_id(env->btf, | |
3146 | member_type_id); | |
3147 | ||
e4f07120 SF |
3148 | if (btf_type_nosize_or_null(member_type) || |
3149 | btf_type_is_resolve_source_only(member_type)) { | |
eb3f595d MKL |
3150 | btf_verifier_log_member(env, v->t, member, |
3151 | "Invalid member"); | |
3152 | return -EINVAL; | |
3153 | } | |
3154 | ||
3155 | if (!env_type_is_resolve_sink(env, member_type) && | |
3156 | !env_type_is_resolved(env, member_type_id)) { | |
3157 | env_stack_set_next_member(env, i + 1); | |
3158 | return env_stack_push(env, member_type, member_type_id); | |
3159 | } | |
179cde8c | 3160 | |
9d5f9f70 YS |
3161 | if (btf_type_kflag(v->t)) |
3162 | err = btf_type_ops(member_type)->check_kflag_member(env, v->t, | |
3163 | member, | |
3164 | member_type); | |
3165 | else | |
3166 | err = btf_type_ops(member_type)->check_member(env, v->t, | |
3167 | member, | |
3168 | member_type); | |
179cde8c MKL |
3169 | if (err) |
3170 | return err; | |
eb3f595d MKL |
3171 | } |
3172 | ||
3173 | env_stack_pop_resolved(env, 0, 0); | |
3174 | ||
3175 | return 0; | |
3176 | } | |
3177 | ||
69b693f0 MKL |
3178 | static void btf_struct_log(struct btf_verifier_env *env, |
3179 | const struct btf_type *t) | |
3180 | { | |
3181 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
3182 | } | |
3183 | ||
42ba1308 KKD |
3184 | enum btf_field_type { |
3185 | BTF_FIELD_SPIN_LOCK, | |
3186 | BTF_FIELD_TIMER, | |
61df10c7 KKD |
3187 | BTF_FIELD_KPTR, |
3188 | }; | |
3189 | ||
3190 | enum { | |
3191 | BTF_FIELD_IGNORE = 0, | |
3192 | BTF_FIELD_FOUND = 1, | |
42ba1308 KKD |
3193 | }; |
3194 | ||
3195 | struct btf_field_info { | |
61df10c7 | 3196 | u32 type_id; |
42ba1308 | 3197 | u32 off; |
c0a5a21c | 3198 | enum bpf_kptr_type type; |
42ba1308 KKD |
3199 | }; |
3200 | ||
3201 | static int btf_find_struct(const struct btf *btf, const struct btf_type *t, | |
3202 | u32 off, int sz, struct btf_field_info *info) | |
3203 | { | |
3204 | if (!__btf_type_is_struct(t)) | |
61df10c7 | 3205 | return BTF_FIELD_IGNORE; |
42ba1308 | 3206 | if (t->size != sz) |
61df10c7 | 3207 | return BTF_FIELD_IGNORE; |
42ba1308 | 3208 | info->off = off; |
61df10c7 KKD |
3209 | return BTF_FIELD_FOUND; |
3210 | } | |
3211 | ||
3212 | static int btf_find_kptr(const struct btf *btf, const struct btf_type *t, | |
3213 | u32 off, int sz, struct btf_field_info *info) | |
3214 | { | |
c0a5a21c | 3215 | enum bpf_kptr_type type; |
61df10c7 KKD |
3216 | u32 res_id; |
3217 | ||
3218 | /* For PTR, sz is always == 8 */ | |
3219 | if (!btf_type_is_ptr(t)) | |
3220 | return BTF_FIELD_IGNORE; | |
3221 | t = btf_type_by_id(btf, t->type); | |
3222 | ||
3223 | if (!btf_type_is_type_tag(t)) | |
3224 | return BTF_FIELD_IGNORE; | |
3225 | /* Reject extra tags */ | |
3226 | if (btf_type_is_type_tag(btf_type_by_id(btf, t->type))) | |
3227 | return -EINVAL; | |
c0a5a21c KKD |
3228 | if (!strcmp("kptr", __btf_name_by_offset(btf, t->name_off))) |
3229 | type = BPF_KPTR_UNREF; | |
3230 | else if (!strcmp("kptr_ref", __btf_name_by_offset(btf, t->name_off))) | |
3231 | type = BPF_KPTR_REF; | |
3232 | else | |
61df10c7 KKD |
3233 | return -EINVAL; |
3234 | ||
3235 | /* Get the base type */ | |
3236 | t = btf_type_skip_modifiers(btf, t->type, &res_id); | |
3237 | /* Only pointer to struct is allowed */ | |
3238 | if (!__btf_type_is_struct(t)) | |
3239 | return -EINVAL; | |
3240 | ||
3241 | info->type_id = res_id; | |
3242 | info->off = off; | |
c0a5a21c | 3243 | info->type = type; |
61df10c7 | 3244 | return BTF_FIELD_FOUND; |
42ba1308 KKD |
3245 | } |
3246 | ||
68134668 | 3247 | static int btf_find_struct_field(const struct btf *btf, const struct btf_type *t, |
42ba1308 KKD |
3248 | const char *name, int sz, int align, |
3249 | enum btf_field_type field_type, | |
61df10c7 | 3250 | struct btf_field_info *info, int info_cnt) |
d83525ca AS |
3251 | { |
3252 | const struct btf_member *member; | |
61df10c7 KKD |
3253 | struct btf_field_info tmp; |
3254 | int ret, idx = 0; | |
42ba1308 | 3255 | u32 i, off; |
d83525ca | 3256 | |
d83525ca AS |
3257 | for_each_member(i, t, member) { |
3258 | const struct btf_type *member_type = btf_type_by_id(btf, | |
3259 | member->type); | |
42ba1308 | 3260 | |
61df10c7 | 3261 | if (name && strcmp(__btf_name_by_offset(btf, member_type->name_off), name)) |
d83525ca | 3262 | continue; |
42ba1308 | 3263 | |
8293eb99 | 3264 | off = __btf_member_bit_offset(t, member); |
d83525ca AS |
3265 | if (off % 8) |
3266 | /* valid C code cannot generate such BTF */ | |
3267 | return -EINVAL; | |
3268 | off /= 8; | |
68134668 AS |
3269 | if (off % align) |
3270 | return -EINVAL; | |
42ba1308 KKD |
3271 | |
3272 | switch (field_type) { | |
3273 | case BTF_FIELD_SPIN_LOCK: | |
3274 | case BTF_FIELD_TIMER: | |
61df10c7 KKD |
3275 | ret = btf_find_struct(btf, member_type, off, sz, |
3276 | idx < info_cnt ? &info[idx] : &tmp); | |
3277 | if (ret < 0) | |
3278 | return ret; | |
3279 | break; | |
3280 | case BTF_FIELD_KPTR: | |
3281 | ret = btf_find_kptr(btf, member_type, off, sz, | |
3282 | idx < info_cnt ? &info[idx] : &tmp); | |
3283 | if (ret < 0) | |
3284 | return ret; | |
3285 | break; | |
42ba1308 KKD |
3286 | default: |
3287 | return -EFAULT; | |
3288 | } | |
61df10c7 KKD |
3289 | |
3290 | if (ret == BTF_FIELD_IGNORE) | |
3291 | continue; | |
3292 | if (idx >= info_cnt) | |
3293 | return -E2BIG; | |
3294 | ++idx; | |
68134668 | 3295 | } |
61df10c7 | 3296 | return idx; |
68134668 AS |
3297 | } |
3298 | ||
3299 | static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t, | |
42ba1308 KKD |
3300 | const char *name, int sz, int align, |
3301 | enum btf_field_type field_type, | |
61df10c7 | 3302 | struct btf_field_info *info, int info_cnt) |
68134668 AS |
3303 | { |
3304 | const struct btf_var_secinfo *vsi; | |
61df10c7 KKD |
3305 | struct btf_field_info tmp; |
3306 | int ret, idx = 0; | |
42ba1308 | 3307 | u32 i, off; |
68134668 AS |
3308 | |
3309 | for_each_vsi(i, t, vsi) { | |
3310 | const struct btf_type *var = btf_type_by_id(btf, vsi->type); | |
3311 | const struct btf_type *var_type = btf_type_by_id(btf, var->type); | |
3312 | ||
42ba1308 KKD |
3313 | off = vsi->offset; |
3314 | ||
61df10c7 | 3315 | if (name && strcmp(__btf_name_by_offset(btf, var_type->name_off), name)) |
68134668 AS |
3316 | continue; |
3317 | if (vsi->size != sz) | |
3318 | continue; | |
68134668 | 3319 | if (off % align) |
d83525ca | 3320 | return -EINVAL; |
42ba1308 KKD |
3321 | |
3322 | switch (field_type) { | |
3323 | case BTF_FIELD_SPIN_LOCK: | |
3324 | case BTF_FIELD_TIMER: | |
61df10c7 KKD |
3325 | ret = btf_find_struct(btf, var_type, off, sz, |
3326 | idx < info_cnt ? &info[idx] : &tmp); | |
3327 | if (ret < 0) | |
3328 | return ret; | |
3329 | break; | |
3330 | case BTF_FIELD_KPTR: | |
3331 | ret = btf_find_kptr(btf, var_type, off, sz, | |
3332 | idx < info_cnt ? &info[idx] : &tmp); | |
3333 | if (ret < 0) | |
3334 | return ret; | |
3335 | break; | |
42ba1308 KKD |
3336 | default: |
3337 | return -EFAULT; | |
3338 | } | |
61df10c7 KKD |
3339 | |
3340 | if (ret == BTF_FIELD_IGNORE) | |
3341 | continue; | |
3342 | if (idx >= info_cnt) | |
3343 | return -E2BIG; | |
3344 | ++idx; | |
d83525ca | 3345 | } |
61df10c7 | 3346 | return idx; |
d83525ca AS |
3347 | } |
3348 | ||
68134668 | 3349 | static int btf_find_field(const struct btf *btf, const struct btf_type *t, |
42ba1308 | 3350 | enum btf_field_type field_type, |
61df10c7 | 3351 | struct btf_field_info *info, int info_cnt) |
68134668 | 3352 | { |
42ba1308 KKD |
3353 | const char *name; |
3354 | int sz, align; | |
3355 | ||
3356 | switch (field_type) { | |
3357 | case BTF_FIELD_SPIN_LOCK: | |
3358 | name = "bpf_spin_lock"; | |
3359 | sz = sizeof(struct bpf_spin_lock); | |
3360 | align = __alignof__(struct bpf_spin_lock); | |
3361 | break; | |
3362 | case BTF_FIELD_TIMER: | |
3363 | name = "bpf_timer"; | |
3364 | sz = sizeof(struct bpf_timer); | |
3365 | align = __alignof__(struct bpf_timer); | |
3366 | break; | |
61df10c7 KKD |
3367 | case BTF_FIELD_KPTR: |
3368 | name = NULL; | |
3369 | sz = sizeof(u64); | |
3370 | align = 8; | |
3371 | break; | |
42ba1308 KKD |
3372 | default: |
3373 | return -EFAULT; | |
3374 | } | |
68134668 AS |
3375 | |
3376 | if (__btf_type_is_struct(t)) | |
61df10c7 | 3377 | return btf_find_struct_field(btf, t, name, sz, align, field_type, info, info_cnt); |
68134668 | 3378 | else if (btf_type_is_datasec(t)) |
61df10c7 | 3379 | return btf_find_datasec_var(btf, t, name, sz, align, field_type, info, info_cnt); |
68134668 AS |
3380 | return -EINVAL; |
3381 | } | |
3382 | ||
3383 | /* find 'struct bpf_spin_lock' in map value. | |
3384 | * return >= 0 offset if found | |
3385 | * and < 0 in case of error | |
3386 | */ | |
3387 | int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t) | |
3388 | { | |
61df10c7 | 3389 | struct btf_field_info info; |
42ba1308 KKD |
3390 | int ret; |
3391 | ||
61df10c7 | 3392 | ret = btf_find_field(btf, t, BTF_FIELD_SPIN_LOCK, &info, 1); |
42ba1308 KKD |
3393 | if (ret < 0) |
3394 | return ret; | |
61df10c7 KKD |
3395 | if (!ret) |
3396 | return -ENOENT; | |
42ba1308 | 3397 | return info.off; |
68134668 AS |
3398 | } |
3399 | ||
3400 | int btf_find_timer(const struct btf *btf, const struct btf_type *t) | |
3401 | { | |
61df10c7 | 3402 | struct btf_field_info info; |
42ba1308 KKD |
3403 | int ret; |
3404 | ||
61df10c7 | 3405 | ret = btf_find_field(btf, t, BTF_FIELD_TIMER, &info, 1); |
42ba1308 KKD |
3406 | if (ret < 0) |
3407 | return ret; | |
61df10c7 KKD |
3408 | if (!ret) |
3409 | return -ENOENT; | |
42ba1308 | 3410 | return info.off; |
68134668 AS |
3411 | } |
3412 | ||
61df10c7 KKD |
3413 | struct bpf_map_value_off *btf_parse_kptrs(const struct btf *btf, |
3414 | const struct btf_type *t) | |
3415 | { | |
3416 | struct btf_field_info info_arr[BPF_MAP_VALUE_OFF_MAX]; | |
3417 | struct bpf_map_value_off *tab; | |
3418 | struct btf *kernel_btf = NULL; | |
3419 | int ret, i, nr_off; | |
3420 | ||
3421 | ret = btf_find_field(btf, t, BTF_FIELD_KPTR, info_arr, ARRAY_SIZE(info_arr)); | |
3422 | if (ret < 0) | |
3423 | return ERR_PTR(ret); | |
3424 | if (!ret) | |
3425 | return NULL; | |
3426 | ||
3427 | nr_off = ret; | |
3428 | tab = kzalloc(offsetof(struct bpf_map_value_off, off[nr_off]), GFP_KERNEL | __GFP_NOWARN); | |
3429 | if (!tab) | |
3430 | return ERR_PTR(-ENOMEM); | |
3431 | ||
3432 | for (i = 0; i < nr_off; i++) { | |
3433 | const struct btf_type *t; | |
3434 | s32 id; | |
3435 | ||
3436 | /* Find type in map BTF, and use it to look up the matching type | |
3437 | * in vmlinux or module BTFs, by name and kind. | |
3438 | */ | |
3439 | t = btf_type_by_id(btf, info_arr[i].type_id); | |
3440 | id = bpf_find_btf_id(__btf_name_by_offset(btf, t->name_off), BTF_INFO_KIND(t->info), | |
3441 | &kernel_btf); | |
3442 | if (id < 0) { | |
3443 | ret = id; | |
3444 | goto end; | |
3445 | } | |
3446 | ||
3447 | tab->off[i].offset = info_arr[i].off; | |
c0a5a21c | 3448 | tab->off[i].type = info_arr[i].type; |
61df10c7 KKD |
3449 | tab->off[i].kptr.btf_id = id; |
3450 | tab->off[i].kptr.btf = kernel_btf; | |
3451 | } | |
3452 | tab->nr_off = nr_off; | |
3453 | return tab; | |
3454 | end: | |
3455 | while (i--) | |
3456 | btf_put(tab->off[i].kptr.btf); | |
3457 | kfree(tab); | |
3458 | return ERR_PTR(ret); | |
3459 | } | |
3460 | ||
31d0bc81 AM |
3461 | static void __btf_struct_show(const struct btf *btf, const struct btf_type *t, |
3462 | u32 type_id, void *data, u8 bits_offset, | |
3463 | struct btf_show *show) | |
b00b8dae | 3464 | { |
b00b8dae | 3465 | const struct btf_member *member; |
31d0bc81 | 3466 | void *safe_data; |
b00b8dae MKL |
3467 | u32 i; |
3468 | ||
31d0bc81 AM |
3469 | safe_data = btf_show_start_struct_type(show, t, type_id, data); |
3470 | if (!safe_data) | |
3471 | return; | |
3472 | ||
b00b8dae MKL |
3473 | for_each_member(i, t, member) { |
3474 | const struct btf_type *member_type = btf_type_by_id(btf, | |
3475 | member->type); | |
b00b8dae | 3476 | const struct btf_kind_operations *ops; |
9d5f9f70 YS |
3477 | u32 member_offset, bitfield_size; |
3478 | u32 bytes_offset; | |
3479 | u8 bits8_offset; | |
b00b8dae | 3480 | |
31d0bc81 | 3481 | btf_show_start_member(show, member); |
b00b8dae | 3482 | |
8293eb99 AS |
3483 | member_offset = __btf_member_bit_offset(t, member); |
3484 | bitfield_size = __btf_member_bitfield_size(t, member); | |
17e3ac81 YS |
3485 | bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset); |
3486 | bits8_offset = BITS_PER_BYTE_MASKED(member_offset); | |
9d5f9f70 | 3487 | if (bitfield_size) { |
31d0bc81 AM |
3488 | safe_data = btf_show_start_type(show, member_type, |
3489 | member->type, | |
3490 | data + bytes_offset); | |
3491 | if (safe_data) | |
3492 | btf_bitfield_show(safe_data, | |
3493 | bits8_offset, | |
3494 | bitfield_size, show); | |
3495 | btf_show_end_type(show); | |
9d5f9f70 | 3496 | } else { |
9d5f9f70 | 3497 | ops = btf_type_ops(member_type); |
31d0bc81 AM |
3498 | ops->show(btf, member_type, member->type, |
3499 | data + bytes_offset, bits8_offset, show); | |
9d5f9f70 | 3500 | } |
31d0bc81 AM |
3501 | |
3502 | btf_show_end_member(show); | |
b00b8dae | 3503 | } |
31d0bc81 AM |
3504 | |
3505 | btf_show_end_struct_type(show); | |
3506 | } | |
3507 | ||
3508 | static void btf_struct_show(const struct btf *btf, const struct btf_type *t, | |
3509 | u32 type_id, void *data, u8 bits_offset, | |
3510 | struct btf_show *show) | |
3511 | { | |
3512 | const struct btf_member *m = show->state.member; | |
3513 | ||
3514 | /* | |
3515 | * First check if any members would be shown (are non-zero). | |
3516 | * See comments above "struct btf_show" definition for more | |
3517 | * details on how this works at a high-level. | |
3518 | */ | |
3519 | if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) { | |
3520 | if (!show->state.depth_check) { | |
3521 | show->state.depth_check = show->state.depth + 1; | |
3522 | show->state.depth_to_show = 0; | |
3523 | } | |
3524 | __btf_struct_show(btf, t, type_id, data, bits_offset, show); | |
3525 | /* Restore saved member data here */ | |
3526 | show->state.member = m; | |
3527 | if (show->state.depth_check != show->state.depth + 1) | |
3528 | return; | |
3529 | show->state.depth_check = 0; | |
3530 | ||
3531 | if (show->state.depth_to_show <= show->state.depth) | |
3532 | return; | |
3533 | /* | |
3534 | * Reaching here indicates we have recursed and found | |
3535 | * non-zero child values. | |
3536 | */ | |
3537 | } | |
3538 | ||
3539 | __btf_struct_show(btf, t, type_id, data, bits_offset, show); | |
b00b8dae MKL |
3540 | } |
3541 | ||
69b693f0 MKL |
3542 | static struct btf_kind_operations struct_ops = { |
3543 | .check_meta = btf_struct_check_meta, | |
eb3f595d | 3544 | .resolve = btf_struct_resolve, |
179cde8c | 3545 | .check_member = btf_struct_check_member, |
9d5f9f70 | 3546 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 3547 | .log_details = btf_struct_log, |
31d0bc81 | 3548 | .show = btf_struct_show, |
69b693f0 MKL |
3549 | }; |
3550 | ||
179cde8c MKL |
3551 | static int btf_enum_check_member(struct btf_verifier_env *env, |
3552 | const struct btf_type *struct_type, | |
3553 | const struct btf_member *member, | |
3554 | const struct btf_type *member_type) | |
3555 | { | |
3556 | u32 struct_bits_off = member->offset; | |
3557 | u32 struct_size, bytes_offset; | |
3558 | ||
3559 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
3560 | btf_verifier_log_member(env, struct_type, member, | |
3561 | "Member is not byte aligned"); | |
3562 | return -EINVAL; | |
3563 | } | |
3564 | ||
3565 | struct_size = struct_type->size; | |
3566 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
da6c7fae | 3567 | if (struct_size - bytes_offset < member_type->size) { |
179cde8c MKL |
3568 | btf_verifier_log_member(env, struct_type, member, |
3569 | "Member exceeds struct_size"); | |
3570 | return -EINVAL; | |
3571 | } | |
3572 | ||
3573 | return 0; | |
3574 | } | |
3575 | ||
9d5f9f70 YS |
3576 | static int btf_enum_check_kflag_member(struct btf_verifier_env *env, |
3577 | const struct btf_type *struct_type, | |
3578 | const struct btf_member *member, | |
3579 | const struct btf_type *member_type) | |
3580 | { | |
3581 | u32 struct_bits_off, nr_bits, bytes_end, struct_size; | |
3582 | u32 int_bitsize = sizeof(int) * BITS_PER_BYTE; | |
3583 | ||
3584 | struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); | |
3585 | nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); | |
3586 | if (!nr_bits) { | |
3587 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
3588 | btf_verifier_log_member(env, struct_type, member, | |
3589 | "Member is not byte aligned"); | |
e3439af4 | 3590 | return -EINVAL; |
9d5f9f70 YS |
3591 | } |
3592 | ||
3593 | nr_bits = int_bitsize; | |
3594 | } else if (nr_bits > int_bitsize) { | |
3595 | btf_verifier_log_member(env, struct_type, member, | |
3596 | "Invalid member bitfield_size"); | |
3597 | return -EINVAL; | |
3598 | } | |
3599 | ||
3600 | struct_size = struct_type->size; | |
3601 | bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits); | |
3602 | if (struct_size < bytes_end) { | |
3603 | btf_verifier_log_member(env, struct_type, member, | |
3604 | "Member exceeds struct_size"); | |
3605 | return -EINVAL; | |
3606 | } | |
3607 | ||
3608 | return 0; | |
3609 | } | |
3610 | ||
69b693f0 MKL |
3611 | static s32 btf_enum_check_meta(struct btf_verifier_env *env, |
3612 | const struct btf_type *t, | |
3613 | u32 meta_left) | |
3614 | { | |
3615 | const struct btf_enum *enums = btf_type_enum(t); | |
3616 | struct btf *btf = env->btf; | |
3617 | u16 i, nr_enums; | |
3618 | u32 meta_needed; | |
3619 | ||
3620 | nr_enums = btf_type_vlen(t); | |
3621 | meta_needed = nr_enums * sizeof(*enums); | |
3622 | ||
3623 | if (meta_left < meta_needed) { | |
3624 | btf_verifier_log_basic(env, t, | |
3625 | "meta_left:%u meta_needed:%u", | |
3626 | meta_left, meta_needed); | |
3627 | return -EINVAL; | |
3628 | } | |
3629 | ||
9d5f9f70 YS |
3630 | if (btf_type_kflag(t)) { |
3631 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
3632 | return -EINVAL; | |
3633 | } | |
3634 | ||
9eea9849 AS |
3635 | if (t->size > 8 || !is_power_of_2(t->size)) { |
3636 | btf_verifier_log_type(env, t, "Unexpected size"); | |
69b693f0 MKL |
3637 | return -EINVAL; |
3638 | } | |
3639 | ||
eb04bbb6 YS |
3640 | /* enum type either no name or a valid one */ |
3641 | if (t->name_off && | |
3642 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
3643 | btf_verifier_log_type(env, t, "Invalid name"); | |
3644 | return -EINVAL; | |
3645 | } | |
3646 | ||
69b693f0 MKL |
3647 | btf_verifier_log_type(env, t, NULL); |
3648 | ||
3649 | for (i = 0; i < nr_enums; i++) { | |
fbcf93eb | 3650 | if (!btf_name_offset_valid(btf, enums[i].name_off)) { |
69b693f0 | 3651 | btf_verifier_log(env, "\tInvalid name_offset:%u", |
fbcf93eb | 3652 | enums[i].name_off); |
69b693f0 MKL |
3653 | return -EINVAL; |
3654 | } | |
3655 | ||
eb04bbb6 YS |
3656 | /* enum member must have a valid name */ |
3657 | if (!enums[i].name_off || | |
3658 | !btf_name_valid_identifier(btf, enums[i].name_off)) { | |
3659 | btf_verifier_log_type(env, t, "Invalid name"); | |
3660 | return -EINVAL; | |
3661 | } | |
3662 | ||
8580ac94 AS |
3663 | if (env->log.level == BPF_LOG_KERNEL) |
3664 | continue; | |
69b693f0 | 3665 | btf_verifier_log(env, "\t%s val=%d\n", |
23127b33 | 3666 | __btf_name_by_offset(btf, enums[i].name_off), |
69b693f0 MKL |
3667 | enums[i].val); |
3668 | } | |
3669 | ||
3670 | return meta_needed; | |
3671 | } | |
3672 | ||
3673 | static void btf_enum_log(struct btf_verifier_env *env, | |
3674 | const struct btf_type *t) | |
3675 | { | |
3676 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
3677 | } | |
3678 | ||
31d0bc81 AM |
3679 | static void btf_enum_show(const struct btf *btf, const struct btf_type *t, |
3680 | u32 type_id, void *data, u8 bits_offset, | |
3681 | struct btf_show *show) | |
b00b8dae MKL |
3682 | { |
3683 | const struct btf_enum *enums = btf_type_enum(t); | |
3684 | u32 i, nr_enums = btf_type_vlen(t); | |
31d0bc81 AM |
3685 | void *safe_data; |
3686 | int v; | |
3687 | ||
3688 | safe_data = btf_show_start_type(show, t, type_id, data); | |
3689 | if (!safe_data) | |
3690 | return; | |
3691 | ||
3692 | v = *(int *)safe_data; | |
b00b8dae MKL |
3693 | |
3694 | for (i = 0; i < nr_enums; i++) { | |
31d0bc81 AM |
3695 | if (v != enums[i].val) |
3696 | continue; | |
3697 | ||
3698 | btf_show_type_value(show, "%s", | |
3699 | __btf_name_by_offset(btf, | |
3700 | enums[i].name_off)); | |
3701 | ||
3702 | btf_show_end_type(show); | |
3703 | return; | |
b00b8dae MKL |
3704 | } |
3705 | ||
31d0bc81 AM |
3706 | btf_show_type_value(show, "%d", v); |
3707 | btf_show_end_type(show); | |
b00b8dae MKL |
3708 | } |
3709 | ||
69b693f0 MKL |
3710 | static struct btf_kind_operations enum_ops = { |
3711 | .check_meta = btf_enum_check_meta, | |
eb3f595d | 3712 | .resolve = btf_df_resolve, |
179cde8c | 3713 | .check_member = btf_enum_check_member, |
9d5f9f70 | 3714 | .check_kflag_member = btf_enum_check_kflag_member, |
69b693f0 | 3715 | .log_details = btf_enum_log, |
31d0bc81 | 3716 | .show = btf_enum_show, |
69b693f0 MKL |
3717 | }; |
3718 | ||
2667a262 MKL |
3719 | static s32 btf_func_proto_check_meta(struct btf_verifier_env *env, |
3720 | const struct btf_type *t, | |
3721 | u32 meta_left) | |
3722 | { | |
3723 | u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param); | |
3724 | ||
3725 | if (meta_left < meta_needed) { | |
3726 | btf_verifier_log_basic(env, t, | |
3727 | "meta_left:%u meta_needed:%u", | |
3728 | meta_left, meta_needed); | |
3729 | return -EINVAL; | |
3730 | } | |
3731 | ||
3732 | if (t->name_off) { | |
3733 | btf_verifier_log_type(env, t, "Invalid name"); | |
3734 | return -EINVAL; | |
3735 | } | |
3736 | ||
9d5f9f70 YS |
3737 | if (btf_type_kflag(t)) { |
3738 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
3739 | return -EINVAL; | |
3740 | } | |
3741 | ||
2667a262 MKL |
3742 | btf_verifier_log_type(env, t, NULL); |
3743 | ||
3744 | return meta_needed; | |
3745 | } | |
3746 | ||
3747 | static void btf_func_proto_log(struct btf_verifier_env *env, | |
3748 | const struct btf_type *t) | |
3749 | { | |
3750 | const struct btf_param *args = (const struct btf_param *)(t + 1); | |
3751 | u16 nr_args = btf_type_vlen(t), i; | |
3752 | ||
3753 | btf_verifier_log(env, "return=%u args=(", t->type); | |
3754 | if (!nr_args) { | |
3755 | btf_verifier_log(env, "void"); | |
3756 | goto done; | |
3757 | } | |
3758 | ||
3759 | if (nr_args == 1 && !args[0].type) { | |
3760 | /* Only one vararg */ | |
3761 | btf_verifier_log(env, "vararg"); | |
3762 | goto done; | |
3763 | } | |
3764 | ||
3765 | btf_verifier_log(env, "%u %s", args[0].type, | |
23127b33 MKL |
3766 | __btf_name_by_offset(env->btf, |
3767 | args[0].name_off)); | |
2667a262 MKL |
3768 | for (i = 1; i < nr_args - 1; i++) |
3769 | btf_verifier_log(env, ", %u %s", args[i].type, | |
23127b33 MKL |
3770 | __btf_name_by_offset(env->btf, |
3771 | args[i].name_off)); | |
2667a262 MKL |
3772 | |
3773 | if (nr_args > 1) { | |
3774 | const struct btf_param *last_arg = &args[nr_args - 1]; | |
3775 | ||
3776 | if (last_arg->type) | |
3777 | btf_verifier_log(env, ", %u %s", last_arg->type, | |
23127b33 MKL |
3778 | __btf_name_by_offset(env->btf, |
3779 | last_arg->name_off)); | |
2667a262 MKL |
3780 | else |
3781 | btf_verifier_log(env, ", vararg"); | |
3782 | } | |
3783 | ||
3784 | done: | |
3785 | btf_verifier_log(env, ")"); | |
3786 | } | |
3787 | ||
3788 | static struct btf_kind_operations func_proto_ops = { | |
3789 | .check_meta = btf_func_proto_check_meta, | |
3790 | .resolve = btf_df_resolve, | |
3791 | /* | |
3792 | * BTF_KIND_FUNC_PROTO cannot be directly referred by | |
3793 | * a struct's member. | |
3794 | * | |
8fb33b60 | 3795 | * It should be a function pointer instead. |
2667a262 MKL |
3796 | * (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO) |
3797 | * | |
3798 | * Hence, there is no btf_func_check_member(). | |
3799 | */ | |
3800 | .check_member = btf_df_check_member, | |
9d5f9f70 | 3801 | .check_kflag_member = btf_df_check_kflag_member, |
2667a262 | 3802 | .log_details = btf_func_proto_log, |
31d0bc81 | 3803 | .show = btf_df_show, |
2667a262 MKL |
3804 | }; |
3805 | ||
3806 | static s32 btf_func_check_meta(struct btf_verifier_env *env, | |
3807 | const struct btf_type *t, | |
3808 | u32 meta_left) | |
3809 | { | |
3810 | if (!t->name_off || | |
3811 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
3812 | btf_verifier_log_type(env, t, "Invalid name"); | |
3813 | return -EINVAL; | |
3814 | } | |
3815 | ||
51c39bb1 AS |
3816 | if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) { |
3817 | btf_verifier_log_type(env, t, "Invalid func linkage"); | |
2667a262 MKL |
3818 | return -EINVAL; |
3819 | } | |
3820 | ||
9d5f9f70 YS |
3821 | if (btf_type_kflag(t)) { |
3822 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
3823 | return -EINVAL; | |
3824 | } | |
3825 | ||
2667a262 MKL |
3826 | btf_verifier_log_type(env, t, NULL); |
3827 | ||
3828 | return 0; | |
3829 | } | |
3830 | ||
d7e7b42f YS |
3831 | static int btf_func_resolve(struct btf_verifier_env *env, |
3832 | const struct resolve_vertex *v) | |
3833 | { | |
3834 | const struct btf_type *t = v->t; | |
3835 | u32 next_type_id = t->type; | |
3836 | int err; | |
3837 | ||
3838 | err = btf_func_check(env, t); | |
3839 | if (err) | |
3840 | return err; | |
3841 | ||
3842 | env_stack_pop_resolved(env, next_type_id, 0); | |
3843 | return 0; | |
3844 | } | |
3845 | ||
2667a262 MKL |
3846 | static struct btf_kind_operations func_ops = { |
3847 | .check_meta = btf_func_check_meta, | |
d7e7b42f | 3848 | .resolve = btf_func_resolve, |
2667a262 | 3849 | .check_member = btf_df_check_member, |
9d5f9f70 | 3850 | .check_kflag_member = btf_df_check_kflag_member, |
2667a262 | 3851 | .log_details = btf_ref_type_log, |
31d0bc81 | 3852 | .show = btf_df_show, |
2667a262 MKL |
3853 | }; |
3854 | ||
1dc92851 DB |
3855 | static s32 btf_var_check_meta(struct btf_verifier_env *env, |
3856 | const struct btf_type *t, | |
3857 | u32 meta_left) | |
3858 | { | |
3859 | const struct btf_var *var; | |
3860 | u32 meta_needed = sizeof(*var); | |
3861 | ||
3862 | if (meta_left < meta_needed) { | |
3863 | btf_verifier_log_basic(env, t, | |
3864 | "meta_left:%u meta_needed:%u", | |
3865 | meta_left, meta_needed); | |
3866 | return -EINVAL; | |
3867 | } | |
3868 | ||
3869 | if (btf_type_vlen(t)) { | |
3870 | btf_verifier_log_type(env, t, "vlen != 0"); | |
3871 | return -EINVAL; | |
3872 | } | |
3873 | ||
3874 | if (btf_type_kflag(t)) { | |
3875 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
3876 | return -EINVAL; | |
3877 | } | |
3878 | ||
3879 | if (!t->name_off || | |
3880 | !__btf_name_valid(env->btf, t->name_off, true)) { | |
3881 | btf_verifier_log_type(env, t, "Invalid name"); | |
3882 | return -EINVAL; | |
3883 | } | |
3884 | ||
3885 | /* A var cannot be in type void */ | |
3886 | if (!t->type || !BTF_TYPE_ID_VALID(t->type)) { | |
3887 | btf_verifier_log_type(env, t, "Invalid type_id"); | |
3888 | return -EINVAL; | |
3889 | } | |
3890 | ||
3891 | var = btf_type_var(t); | |
3892 | if (var->linkage != BTF_VAR_STATIC && | |
3893 | var->linkage != BTF_VAR_GLOBAL_ALLOCATED) { | |
3894 | btf_verifier_log_type(env, t, "Linkage not supported"); | |
3895 | return -EINVAL; | |
3896 | } | |
3897 | ||
3898 | btf_verifier_log_type(env, t, NULL); | |
3899 | ||
3900 | return meta_needed; | |
3901 | } | |
3902 | ||
3903 | static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t) | |
3904 | { | |
3905 | const struct btf_var *var = btf_type_var(t); | |
3906 | ||
3907 | btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage); | |
3908 | } | |
3909 | ||
3910 | static const struct btf_kind_operations var_ops = { | |
3911 | .check_meta = btf_var_check_meta, | |
3912 | .resolve = btf_var_resolve, | |
3913 | .check_member = btf_df_check_member, | |
3914 | .check_kflag_member = btf_df_check_kflag_member, | |
3915 | .log_details = btf_var_log, | |
31d0bc81 | 3916 | .show = btf_var_show, |
1dc92851 DB |
3917 | }; |
3918 | ||
3919 | static s32 btf_datasec_check_meta(struct btf_verifier_env *env, | |
3920 | const struct btf_type *t, | |
3921 | u32 meta_left) | |
3922 | { | |
3923 | const struct btf_var_secinfo *vsi; | |
3924 | u64 last_vsi_end_off = 0, sum = 0; | |
3925 | u32 i, meta_needed; | |
3926 | ||
3927 | meta_needed = btf_type_vlen(t) * sizeof(*vsi); | |
3928 | if (meta_left < meta_needed) { | |
3929 | btf_verifier_log_basic(env, t, | |
3930 | "meta_left:%u meta_needed:%u", | |
3931 | meta_left, meta_needed); | |
3932 | return -EINVAL; | |
3933 | } | |
3934 | ||
1dc92851 DB |
3935 | if (!t->size) { |
3936 | btf_verifier_log_type(env, t, "size == 0"); | |
3937 | return -EINVAL; | |
3938 | } | |
3939 | ||
3940 | if (btf_type_kflag(t)) { | |
3941 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
3942 | return -EINVAL; | |
3943 | } | |
3944 | ||
3945 | if (!t->name_off || | |
3946 | !btf_name_valid_section(env->btf, t->name_off)) { | |
3947 | btf_verifier_log_type(env, t, "Invalid name"); | |
3948 | return -EINVAL; | |
3949 | } | |
3950 | ||
3951 | btf_verifier_log_type(env, t, NULL); | |
3952 | ||
3953 | for_each_vsi(i, t, vsi) { | |
3954 | /* A var cannot be in type void */ | |
3955 | if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) { | |
3956 | btf_verifier_log_vsi(env, t, vsi, | |
3957 | "Invalid type_id"); | |
3958 | return -EINVAL; | |
3959 | } | |
3960 | ||
3961 | if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) { | |
3962 | btf_verifier_log_vsi(env, t, vsi, | |
3963 | "Invalid offset"); | |
3964 | return -EINVAL; | |
3965 | } | |
3966 | ||
3967 | if (!vsi->size || vsi->size > t->size) { | |
3968 | btf_verifier_log_vsi(env, t, vsi, | |
3969 | "Invalid size"); | |
3970 | return -EINVAL; | |
3971 | } | |
3972 | ||
3973 | last_vsi_end_off = vsi->offset + vsi->size; | |
3974 | if (last_vsi_end_off > t->size) { | |
3975 | btf_verifier_log_vsi(env, t, vsi, | |
3976 | "Invalid offset+size"); | |
3977 | return -EINVAL; | |
3978 | } | |
3979 | ||
3980 | btf_verifier_log_vsi(env, t, vsi, NULL); | |
3981 | sum += vsi->size; | |
3982 | } | |
3983 | ||
3984 | if (t->size < sum) { | |
3985 | btf_verifier_log_type(env, t, "Invalid btf_info size"); | |
3986 | return -EINVAL; | |
3987 | } | |
3988 | ||
3989 | return meta_needed; | |
3990 | } | |
3991 | ||
3992 | static int btf_datasec_resolve(struct btf_verifier_env *env, | |
3993 | const struct resolve_vertex *v) | |
3994 | { | |
3995 | const struct btf_var_secinfo *vsi; | |
3996 | struct btf *btf = env->btf; | |
3997 | u16 i; | |
3998 | ||
3999 | for_each_vsi_from(i, v->next_member, v->t, vsi) { | |
4000 | u32 var_type_id = vsi->type, type_id, type_size = 0; | |
4001 | const struct btf_type *var_type = btf_type_by_id(env->btf, | |
4002 | var_type_id); | |
4003 | if (!var_type || !btf_type_is_var(var_type)) { | |
4004 | btf_verifier_log_vsi(env, v->t, vsi, | |
4005 | "Not a VAR kind member"); | |
4006 | return -EINVAL; | |
4007 | } | |
4008 | ||
4009 | if (!env_type_is_resolve_sink(env, var_type) && | |
4010 | !env_type_is_resolved(env, var_type_id)) { | |
4011 | env_stack_set_next_member(env, i + 1); | |
4012 | return env_stack_push(env, var_type, var_type_id); | |
4013 | } | |
4014 | ||
4015 | type_id = var_type->type; | |
4016 | if (!btf_type_id_size(btf, &type_id, &type_size)) { | |
4017 | btf_verifier_log_vsi(env, v->t, vsi, "Invalid type"); | |
4018 | return -EINVAL; | |
4019 | } | |
4020 | ||
4021 | if (vsi->size < type_size) { | |
4022 | btf_verifier_log_vsi(env, v->t, vsi, "Invalid size"); | |
4023 | return -EINVAL; | |
4024 | } | |
4025 | } | |
4026 | ||
4027 | env_stack_pop_resolved(env, 0, 0); | |
4028 | return 0; | |
4029 | } | |
4030 | ||
4031 | static void btf_datasec_log(struct btf_verifier_env *env, | |
4032 | const struct btf_type *t) | |
4033 | { | |
4034 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
4035 | } | |
4036 | ||
31d0bc81 AM |
4037 | static void btf_datasec_show(const struct btf *btf, |
4038 | const struct btf_type *t, u32 type_id, | |
4039 | void *data, u8 bits_offset, | |
4040 | struct btf_show *show) | |
1dc92851 DB |
4041 | { |
4042 | const struct btf_var_secinfo *vsi; | |
4043 | const struct btf_type *var; | |
4044 | u32 i; | |
4045 | ||
31d0bc81 AM |
4046 | if (!btf_show_start_type(show, t, type_id, data)) |
4047 | return; | |
4048 | ||
4049 | btf_show_type_value(show, "section (\"%s\") = {", | |
4050 | __btf_name_by_offset(btf, t->name_off)); | |
1dc92851 DB |
4051 | for_each_vsi(i, t, vsi) { |
4052 | var = btf_type_by_id(btf, vsi->type); | |
4053 | if (i) | |
31d0bc81 AM |
4054 | btf_show(show, ","); |
4055 | btf_type_ops(var)->show(btf, var, vsi->type, | |
4056 | data + vsi->offset, bits_offset, show); | |
1dc92851 | 4057 | } |
31d0bc81 | 4058 | btf_show_end_type(show); |
1dc92851 DB |
4059 | } |
4060 | ||
4061 | static const struct btf_kind_operations datasec_ops = { | |
4062 | .check_meta = btf_datasec_check_meta, | |
4063 | .resolve = btf_datasec_resolve, | |
4064 | .check_member = btf_df_check_member, | |
4065 | .check_kflag_member = btf_df_check_kflag_member, | |
4066 | .log_details = btf_datasec_log, | |
31d0bc81 | 4067 | .show = btf_datasec_show, |
1dc92851 DB |
4068 | }; |
4069 | ||
b1828f0b IL |
4070 | static s32 btf_float_check_meta(struct btf_verifier_env *env, |
4071 | const struct btf_type *t, | |
4072 | u32 meta_left) | |
4073 | { | |
4074 | if (btf_type_vlen(t)) { | |
4075 | btf_verifier_log_type(env, t, "vlen != 0"); | |
4076 | return -EINVAL; | |
4077 | } | |
4078 | ||
4079 | if (btf_type_kflag(t)) { | |
4080 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4081 | return -EINVAL; | |
4082 | } | |
4083 | ||
4084 | if (t->size != 2 && t->size != 4 && t->size != 8 && t->size != 12 && | |
4085 | t->size != 16) { | |
4086 | btf_verifier_log_type(env, t, "Invalid type_size"); | |
4087 | return -EINVAL; | |
4088 | } | |
4089 | ||
4090 | btf_verifier_log_type(env, t, NULL); | |
4091 | ||
4092 | return 0; | |
4093 | } | |
4094 | ||
4095 | static int btf_float_check_member(struct btf_verifier_env *env, | |
4096 | const struct btf_type *struct_type, | |
4097 | const struct btf_member *member, | |
4098 | const struct btf_type *member_type) | |
4099 | { | |
4100 | u64 start_offset_bytes; | |
4101 | u64 end_offset_bytes; | |
4102 | u64 misalign_bits; | |
4103 | u64 align_bytes; | |
4104 | u64 align_bits; | |
4105 | ||
4106 | /* Different architectures have different alignment requirements, so | |
4107 | * here we check only for the reasonable minimum. This way we ensure | |
4108 | * that types after CO-RE can pass the kernel BTF verifier. | |
4109 | */ | |
4110 | align_bytes = min_t(u64, sizeof(void *), member_type->size); | |
4111 | align_bits = align_bytes * BITS_PER_BYTE; | |
4112 | div64_u64_rem(member->offset, align_bits, &misalign_bits); | |
4113 | if (misalign_bits) { | |
4114 | btf_verifier_log_member(env, struct_type, member, | |
4115 | "Member is not properly aligned"); | |
4116 | return -EINVAL; | |
4117 | } | |
4118 | ||
4119 | start_offset_bytes = member->offset / BITS_PER_BYTE; | |
4120 | end_offset_bytes = start_offset_bytes + member_type->size; | |
4121 | if (end_offset_bytes > struct_type->size) { | |
4122 | btf_verifier_log_member(env, struct_type, member, | |
4123 | "Member exceeds struct_size"); | |
4124 | return -EINVAL; | |
4125 | } | |
4126 | ||
4127 | return 0; | |
4128 | } | |
4129 | ||
4130 | static void btf_float_log(struct btf_verifier_env *env, | |
4131 | const struct btf_type *t) | |
4132 | { | |
4133 | btf_verifier_log(env, "size=%u", t->size); | |
4134 | } | |
4135 | ||
4136 | static const struct btf_kind_operations float_ops = { | |
4137 | .check_meta = btf_float_check_meta, | |
4138 | .resolve = btf_df_resolve, | |
4139 | .check_member = btf_float_check_member, | |
4140 | .check_kflag_member = btf_generic_check_kflag_member, | |
4141 | .log_details = btf_float_log, | |
4142 | .show = btf_df_show, | |
4143 | }; | |
4144 | ||
223f903e | 4145 | static s32 btf_decl_tag_check_meta(struct btf_verifier_env *env, |
b5ea834d YS |
4146 | const struct btf_type *t, |
4147 | u32 meta_left) | |
4148 | { | |
223f903e | 4149 | const struct btf_decl_tag *tag; |
b5ea834d YS |
4150 | u32 meta_needed = sizeof(*tag); |
4151 | s32 component_idx; | |
4152 | const char *value; | |
4153 | ||
4154 | if (meta_left < meta_needed) { | |
4155 | btf_verifier_log_basic(env, t, | |
4156 | "meta_left:%u meta_needed:%u", | |
4157 | meta_left, meta_needed); | |
4158 | return -EINVAL; | |
4159 | } | |
4160 | ||
4161 | value = btf_name_by_offset(env->btf, t->name_off); | |
4162 | if (!value || !value[0]) { | |
4163 | btf_verifier_log_type(env, t, "Invalid value"); | |
4164 | return -EINVAL; | |
4165 | } | |
4166 | ||
4167 | if (btf_type_vlen(t)) { | |
4168 | btf_verifier_log_type(env, t, "vlen != 0"); | |
4169 | return -EINVAL; | |
4170 | } | |
4171 | ||
4172 | if (btf_type_kflag(t)) { | |
4173 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4174 | return -EINVAL; | |
4175 | } | |
4176 | ||
223f903e | 4177 | component_idx = btf_type_decl_tag(t)->component_idx; |
b5ea834d YS |
4178 | if (component_idx < -1) { |
4179 | btf_verifier_log_type(env, t, "Invalid component_idx"); | |
4180 | return -EINVAL; | |
4181 | } | |
4182 | ||
4183 | btf_verifier_log_type(env, t, NULL); | |
4184 | ||
4185 | return meta_needed; | |
4186 | } | |
4187 | ||
223f903e | 4188 | static int btf_decl_tag_resolve(struct btf_verifier_env *env, |
b5ea834d YS |
4189 | const struct resolve_vertex *v) |
4190 | { | |
4191 | const struct btf_type *next_type; | |
4192 | const struct btf_type *t = v->t; | |
4193 | u32 next_type_id = t->type; | |
4194 | struct btf *btf = env->btf; | |
4195 | s32 component_idx; | |
4196 | u32 vlen; | |
4197 | ||
4198 | next_type = btf_type_by_id(btf, next_type_id); | |
223f903e | 4199 | if (!next_type || !btf_type_is_decl_tag_target(next_type)) { |
b5ea834d YS |
4200 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
4201 | return -EINVAL; | |
4202 | } | |
4203 | ||
4204 | if (!env_type_is_resolve_sink(env, next_type) && | |
4205 | !env_type_is_resolved(env, next_type_id)) | |
4206 | return env_stack_push(env, next_type, next_type_id); | |
4207 | ||
223f903e | 4208 | component_idx = btf_type_decl_tag(t)->component_idx; |
b5ea834d | 4209 | if (component_idx != -1) { |
bd16dee6 | 4210 | if (btf_type_is_var(next_type) || btf_type_is_typedef(next_type)) { |
b5ea834d YS |
4211 | btf_verifier_log_type(env, v->t, "Invalid component_idx"); |
4212 | return -EINVAL; | |
4213 | } | |
4214 | ||
4215 | if (btf_type_is_struct(next_type)) { | |
4216 | vlen = btf_type_vlen(next_type); | |
4217 | } else { | |
4218 | /* next_type should be a function */ | |
4219 | next_type = btf_type_by_id(btf, next_type->type); | |
4220 | vlen = btf_type_vlen(next_type); | |
4221 | } | |
4222 | ||
4223 | if ((u32)component_idx >= vlen) { | |
4224 | btf_verifier_log_type(env, v->t, "Invalid component_idx"); | |
4225 | return -EINVAL; | |
4226 | } | |
4227 | } | |
4228 | ||
4229 | env_stack_pop_resolved(env, next_type_id, 0); | |
4230 | ||
4231 | return 0; | |
4232 | } | |
4233 | ||
223f903e | 4234 | static void btf_decl_tag_log(struct btf_verifier_env *env, const struct btf_type *t) |
b5ea834d YS |
4235 | { |
4236 | btf_verifier_log(env, "type=%u component_idx=%d", t->type, | |
223f903e | 4237 | btf_type_decl_tag(t)->component_idx); |
b5ea834d YS |
4238 | } |
4239 | ||
223f903e YS |
4240 | static const struct btf_kind_operations decl_tag_ops = { |
4241 | .check_meta = btf_decl_tag_check_meta, | |
4242 | .resolve = btf_decl_tag_resolve, | |
b5ea834d YS |
4243 | .check_member = btf_df_check_member, |
4244 | .check_kflag_member = btf_df_check_kflag_member, | |
223f903e | 4245 | .log_details = btf_decl_tag_log, |
b5ea834d YS |
4246 | .show = btf_df_show, |
4247 | }; | |
4248 | ||
2667a262 MKL |
4249 | static int btf_func_proto_check(struct btf_verifier_env *env, |
4250 | const struct btf_type *t) | |
4251 | { | |
4252 | const struct btf_type *ret_type; | |
4253 | const struct btf_param *args; | |
4254 | const struct btf *btf; | |
4255 | u16 nr_args, i; | |
4256 | int err; | |
4257 | ||
4258 | btf = env->btf; | |
4259 | args = (const struct btf_param *)(t + 1); | |
4260 | nr_args = btf_type_vlen(t); | |
4261 | ||
4262 | /* Check func return type which could be "void" (t->type == 0) */ | |
4263 | if (t->type) { | |
4264 | u32 ret_type_id = t->type; | |
4265 | ||
4266 | ret_type = btf_type_by_id(btf, ret_type_id); | |
4267 | if (!ret_type) { | |
4268 | btf_verifier_log_type(env, t, "Invalid return type"); | |
4269 | return -EINVAL; | |
4270 | } | |
4271 | ||
4272 | if (btf_type_needs_resolve(ret_type) && | |
4273 | !env_type_is_resolved(env, ret_type_id)) { | |
4274 | err = btf_resolve(env, ret_type, ret_type_id); | |
4275 | if (err) | |
4276 | return err; | |
4277 | } | |
4278 | ||
4279 | /* Ensure the return type is a type that has a size */ | |
4280 | if (!btf_type_id_size(btf, &ret_type_id, NULL)) { | |
4281 | btf_verifier_log_type(env, t, "Invalid return type"); | |
4282 | return -EINVAL; | |
4283 | } | |
4284 | } | |
4285 | ||
4286 | if (!nr_args) | |
4287 | return 0; | |
4288 | ||
4289 | /* Last func arg type_id could be 0 if it is a vararg */ | |
4290 | if (!args[nr_args - 1].type) { | |
4291 | if (args[nr_args - 1].name_off) { | |
4292 | btf_verifier_log_type(env, t, "Invalid arg#%u", | |
4293 | nr_args); | |
4294 | return -EINVAL; | |
4295 | } | |
4296 | nr_args--; | |
4297 | } | |
4298 | ||
4299 | err = 0; | |
4300 | for (i = 0; i < nr_args; i++) { | |
4301 | const struct btf_type *arg_type; | |
4302 | u32 arg_type_id; | |
4303 | ||
4304 | arg_type_id = args[i].type; | |
4305 | arg_type = btf_type_by_id(btf, arg_type_id); | |
4306 | if (!arg_type) { | |
4307 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
4308 | err = -EINVAL; | |
4309 | break; | |
4310 | } | |
4311 | ||
4312 | if (args[i].name_off && | |
4313 | (!btf_name_offset_valid(btf, args[i].name_off) || | |
4314 | !btf_name_valid_identifier(btf, args[i].name_off))) { | |
4315 | btf_verifier_log_type(env, t, | |
4316 | "Invalid arg#%u", i + 1); | |
4317 | err = -EINVAL; | |
4318 | break; | |
4319 | } | |
4320 | ||
4321 | if (btf_type_needs_resolve(arg_type) && | |
4322 | !env_type_is_resolved(env, arg_type_id)) { | |
4323 | err = btf_resolve(env, arg_type, arg_type_id); | |
4324 | if (err) | |
4325 | break; | |
4326 | } | |
4327 | ||
4328 | if (!btf_type_id_size(btf, &arg_type_id, NULL)) { | |
4329 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
4330 | err = -EINVAL; | |
4331 | break; | |
4332 | } | |
4333 | } | |
4334 | ||
4335 | return err; | |
4336 | } | |
4337 | ||
4338 | static int btf_func_check(struct btf_verifier_env *env, | |
4339 | const struct btf_type *t) | |
4340 | { | |
4341 | const struct btf_type *proto_type; | |
4342 | const struct btf_param *args; | |
4343 | const struct btf *btf; | |
4344 | u16 nr_args, i; | |
4345 | ||
4346 | btf = env->btf; | |
4347 | proto_type = btf_type_by_id(btf, t->type); | |
4348 | ||
4349 | if (!proto_type || !btf_type_is_func_proto(proto_type)) { | |
4350 | btf_verifier_log_type(env, t, "Invalid type_id"); | |
4351 | return -EINVAL; | |
4352 | } | |
4353 | ||
4354 | args = (const struct btf_param *)(proto_type + 1); | |
4355 | nr_args = btf_type_vlen(proto_type); | |
4356 | for (i = 0; i < nr_args; i++) { | |
4357 | if (!args[i].name_off && args[i].type) { | |
4358 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
4359 | return -EINVAL; | |
4360 | } | |
4361 | } | |
4362 | ||
4363 | return 0; | |
4364 | } | |
4365 | ||
69b693f0 MKL |
4366 | static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = { |
4367 | [BTF_KIND_INT] = &int_ops, | |
4368 | [BTF_KIND_PTR] = &ptr_ops, | |
4369 | [BTF_KIND_ARRAY] = &array_ops, | |
4370 | [BTF_KIND_STRUCT] = &struct_ops, | |
4371 | [BTF_KIND_UNION] = &struct_ops, | |
4372 | [BTF_KIND_ENUM] = &enum_ops, | |
4373 | [BTF_KIND_FWD] = &fwd_ops, | |
4374 | [BTF_KIND_TYPEDEF] = &modifier_ops, | |
4375 | [BTF_KIND_VOLATILE] = &modifier_ops, | |
4376 | [BTF_KIND_CONST] = &modifier_ops, | |
4377 | [BTF_KIND_RESTRICT] = &modifier_ops, | |
2667a262 MKL |
4378 | [BTF_KIND_FUNC] = &func_ops, |
4379 | [BTF_KIND_FUNC_PROTO] = &func_proto_ops, | |
1dc92851 DB |
4380 | [BTF_KIND_VAR] = &var_ops, |
4381 | [BTF_KIND_DATASEC] = &datasec_ops, | |
b1828f0b | 4382 | [BTF_KIND_FLOAT] = &float_ops, |
223f903e | 4383 | [BTF_KIND_DECL_TAG] = &decl_tag_ops, |
8c42d2fa | 4384 | [BTF_KIND_TYPE_TAG] = &modifier_ops, |
69b693f0 MKL |
4385 | }; |
4386 | ||
4387 | static s32 btf_check_meta(struct btf_verifier_env *env, | |
4388 | const struct btf_type *t, | |
4389 | u32 meta_left) | |
4390 | { | |
4391 | u32 saved_meta_left = meta_left; | |
4392 | s32 var_meta_size; | |
4393 | ||
4394 | if (meta_left < sizeof(*t)) { | |
4395 | btf_verifier_log(env, "[%u] meta_left:%u meta_needed:%zu", | |
4396 | env->log_type_id, meta_left, sizeof(*t)); | |
4397 | return -EINVAL; | |
4398 | } | |
4399 | meta_left -= sizeof(*t); | |
4400 | ||
aea2f7b8 MKL |
4401 | if (t->info & ~BTF_INFO_MASK) { |
4402 | btf_verifier_log(env, "[%u] Invalid btf_info:%x", | |
4403 | env->log_type_id, t->info); | |
4404 | return -EINVAL; | |
4405 | } | |
4406 | ||
69b693f0 MKL |
4407 | if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX || |
4408 | BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) { | |
4409 | btf_verifier_log(env, "[%u] Invalid kind:%u", | |
4410 | env->log_type_id, BTF_INFO_KIND(t->info)); | |
4411 | return -EINVAL; | |
4412 | } | |
4413 | ||
fbcf93eb | 4414 | if (!btf_name_offset_valid(env->btf, t->name_off)) { |
69b693f0 | 4415 | btf_verifier_log(env, "[%u] Invalid name_offset:%u", |
fbcf93eb | 4416 | env->log_type_id, t->name_off); |
69b693f0 MKL |
4417 | return -EINVAL; |
4418 | } | |
4419 | ||
4420 | var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left); | |
4421 | if (var_meta_size < 0) | |
4422 | return var_meta_size; | |
4423 | ||
4424 | meta_left -= var_meta_size; | |
4425 | ||
4426 | return saved_meta_left - meta_left; | |
4427 | } | |
4428 | ||
4429 | static int btf_check_all_metas(struct btf_verifier_env *env) | |
4430 | { | |
4431 | struct btf *btf = env->btf; | |
4432 | struct btf_header *hdr; | |
4433 | void *cur, *end; | |
4434 | ||
f80442a4 | 4435 | hdr = &btf->hdr; |
69b693f0 | 4436 | cur = btf->nohdr_data + hdr->type_off; |
4b1c5d91 | 4437 | end = cur + hdr->type_len; |
69b693f0 | 4438 | |
951bb646 | 4439 | env->log_type_id = btf->base_btf ? btf->start_id : 1; |
69b693f0 MKL |
4440 | while (cur < end) { |
4441 | struct btf_type *t = cur; | |
4442 | s32 meta_size; | |
4443 | ||
4444 | meta_size = btf_check_meta(env, t, end - cur); | |
4445 | if (meta_size < 0) | |
4446 | return meta_size; | |
4447 | ||
4448 | btf_add_type(env, t); | |
4449 | cur += meta_size; | |
4450 | env->log_type_id++; | |
4451 | } | |
4452 | ||
4453 | return 0; | |
4454 | } | |
4455 | ||
eb3f595d MKL |
4456 | static bool btf_resolve_valid(struct btf_verifier_env *env, |
4457 | const struct btf_type *t, | |
4458 | u32 type_id) | |
4459 | { | |
4460 | struct btf *btf = env->btf; | |
4461 | ||
4462 | if (!env_type_is_resolved(env, type_id)) | |
4463 | return false; | |
4464 | ||
1dc92851 | 4465 | if (btf_type_is_struct(t) || btf_type_is_datasec(t)) |
951bb646 AN |
4466 | return !btf_resolved_type_id(btf, type_id) && |
4467 | !btf_resolved_type_size(btf, type_id); | |
eb3f595d | 4468 | |
d7e7b42f | 4469 | if (btf_type_is_decl_tag(t) || btf_type_is_func(t)) |
b5ea834d YS |
4470 | return btf_resolved_type_id(btf, type_id) && |
4471 | !btf_resolved_type_size(btf, type_id); | |
4472 | ||
1dc92851 DB |
4473 | if (btf_type_is_modifier(t) || btf_type_is_ptr(t) || |
4474 | btf_type_is_var(t)) { | |
eb3f595d | 4475 | t = btf_type_id_resolve(btf, &type_id); |
1dc92851 DB |
4476 | return t && |
4477 | !btf_type_is_modifier(t) && | |
4478 | !btf_type_is_var(t) && | |
4479 | !btf_type_is_datasec(t); | |
eb3f595d MKL |
4480 | } |
4481 | ||
4482 | if (btf_type_is_array(t)) { | |
4483 | const struct btf_array *array = btf_type_array(t); | |
4484 | const struct btf_type *elem_type; | |
4485 | u32 elem_type_id = array->type; | |
4486 | u32 elem_size; | |
4487 | ||
4488 | elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); | |
4489 | return elem_type && !btf_type_is_modifier(elem_type) && | |
4490 | (array->nelems * elem_size == | |
951bb646 | 4491 | btf_resolved_type_size(btf, type_id)); |
eb3f595d MKL |
4492 | } |
4493 | ||
4494 | return false; | |
4495 | } | |
4496 | ||
2667a262 MKL |
4497 | static int btf_resolve(struct btf_verifier_env *env, |
4498 | const struct btf_type *t, u32 type_id) | |
4499 | { | |
4500 | u32 save_log_type_id = env->log_type_id; | |
4501 | const struct resolve_vertex *v; | |
4502 | int err = 0; | |
4503 | ||
4504 | env->resolve_mode = RESOLVE_TBD; | |
4505 | env_stack_push(env, t, type_id); | |
4506 | while (!err && (v = env_stack_peak(env))) { | |
4507 | env->log_type_id = v->type_id; | |
4508 | err = btf_type_ops(v->t)->resolve(env, v); | |
4509 | } | |
4510 | ||
4511 | env->log_type_id = type_id; | |
4512 | if (err == -E2BIG) { | |
4513 | btf_verifier_log_type(env, t, | |
4514 | "Exceeded max resolving depth:%u", | |
4515 | MAX_RESOLVE_DEPTH); | |
4516 | } else if (err == -EEXIST) { | |
4517 | btf_verifier_log_type(env, t, "Loop detected"); | |
4518 | } | |
4519 | ||
4520 | /* Final sanity check */ | |
4521 | if (!err && !btf_resolve_valid(env, t, type_id)) { | |
4522 | btf_verifier_log_type(env, t, "Invalid resolve state"); | |
4523 | err = -EINVAL; | |
4524 | } | |
4525 | ||
4526 | env->log_type_id = save_log_type_id; | |
4527 | return err; | |
4528 | } | |
4529 | ||
eb3f595d MKL |
4530 | static int btf_check_all_types(struct btf_verifier_env *env) |
4531 | { | |
4532 | struct btf *btf = env->btf; | |
951bb646 AN |
4533 | const struct btf_type *t; |
4534 | u32 type_id, i; | |
eb3f595d MKL |
4535 | int err; |
4536 | ||
4537 | err = env_resolve_init(env); | |
4538 | if (err) | |
4539 | return err; | |
4540 | ||
4541 | env->phase++; | |
951bb646 AN |
4542 | for (i = btf->base_btf ? 0 : 1; i < btf->nr_types; i++) { |
4543 | type_id = btf->start_id + i; | |
4544 | t = btf_type_by_id(btf, type_id); | |
eb3f595d MKL |
4545 | |
4546 | env->log_type_id = type_id; | |
4547 | if (btf_type_needs_resolve(t) && | |
4548 | !env_type_is_resolved(env, type_id)) { | |
4549 | err = btf_resolve(env, t, type_id); | |
4550 | if (err) | |
4551 | return err; | |
4552 | } | |
4553 | ||
2667a262 MKL |
4554 | if (btf_type_is_func_proto(t)) { |
4555 | err = btf_func_proto_check(env, t); | |
4556 | if (err) | |
4557 | return err; | |
4558 | } | |
eb3f595d MKL |
4559 | } |
4560 | ||
4561 | return 0; | |
4562 | } | |
4563 | ||
69b693f0 MKL |
4564 | static int btf_parse_type_sec(struct btf_verifier_env *env) |
4565 | { | |
f80442a4 | 4566 | const struct btf_header *hdr = &env->btf->hdr; |
eb3f595d MKL |
4567 | int err; |
4568 | ||
f80442a4 MKL |
4569 | /* Type section must align to 4 bytes */ |
4570 | if (hdr->type_off & (sizeof(u32) - 1)) { | |
4571 | btf_verifier_log(env, "Unaligned type_off"); | |
4572 | return -EINVAL; | |
4573 | } | |
4574 | ||
951bb646 | 4575 | if (!env->btf->base_btf && !hdr->type_len) { |
f80442a4 MKL |
4576 | btf_verifier_log(env, "No type found"); |
4577 | return -EINVAL; | |
4578 | } | |
4579 | ||
eb3f595d MKL |
4580 | err = btf_check_all_metas(env); |
4581 | if (err) | |
4582 | return err; | |
4583 | ||
4584 | return btf_check_all_types(env); | |
69b693f0 MKL |
4585 | } |
4586 | ||
4587 | static int btf_parse_str_sec(struct btf_verifier_env *env) | |
4588 | { | |
4589 | const struct btf_header *hdr; | |
4590 | struct btf *btf = env->btf; | |
4591 | const char *start, *end; | |
4592 | ||
f80442a4 | 4593 | hdr = &btf->hdr; |
69b693f0 MKL |
4594 | start = btf->nohdr_data + hdr->str_off; |
4595 | end = start + hdr->str_len; | |
4596 | ||
f80442a4 MKL |
4597 | if (end != btf->data + btf->data_size) { |
4598 | btf_verifier_log(env, "String section is not at the end"); | |
4599 | return -EINVAL; | |
4600 | } | |
4601 | ||
951bb646 AN |
4602 | btf->strings = start; |
4603 | ||
4604 | if (btf->base_btf && !hdr->str_len) | |
4605 | return 0; | |
4606 | if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET || end[-1]) { | |
4607 | btf_verifier_log(env, "Invalid string section"); | |
4608 | return -EINVAL; | |
4609 | } | |
4610 | if (!btf->base_btf && start[0]) { | |
69b693f0 MKL |
4611 | btf_verifier_log(env, "Invalid string section"); |
4612 | return -EINVAL; | |
4613 | } | |
69b693f0 MKL |
4614 | |
4615 | return 0; | |
4616 | } | |
4617 | ||
f80442a4 MKL |
4618 | static const size_t btf_sec_info_offset[] = { |
4619 | offsetof(struct btf_header, type_off), | |
4620 | offsetof(struct btf_header, str_off), | |
4621 | }; | |
4622 | ||
4623 | static int btf_sec_info_cmp(const void *a, const void *b) | |
69b693f0 | 4624 | { |
f80442a4 MKL |
4625 | const struct btf_sec_info *x = a; |
4626 | const struct btf_sec_info *y = b; | |
4627 | ||
4628 | return (int)(x->off - y->off) ? : (int)(x->len - y->len); | |
4629 | } | |
4630 | ||
4631 | static int btf_check_sec_info(struct btf_verifier_env *env, | |
4632 | u32 btf_data_size) | |
4633 | { | |
a2889a4c | 4634 | struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)]; |
f80442a4 | 4635 | u32 total, expected_total, i; |
69b693f0 | 4636 | const struct btf_header *hdr; |
f80442a4 MKL |
4637 | const struct btf *btf; |
4638 | ||
4639 | btf = env->btf; | |
4640 | hdr = &btf->hdr; | |
4641 | ||
4642 | /* Populate the secs from hdr */ | |
a2889a4c | 4643 | for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) |
f80442a4 MKL |
4644 | secs[i] = *(struct btf_sec_info *)((void *)hdr + |
4645 | btf_sec_info_offset[i]); | |
4646 | ||
a2889a4c MKL |
4647 | sort(secs, ARRAY_SIZE(btf_sec_info_offset), |
4648 | sizeof(struct btf_sec_info), btf_sec_info_cmp, NULL); | |
f80442a4 MKL |
4649 | |
4650 | /* Check for gaps and overlap among sections */ | |
4651 | total = 0; | |
4652 | expected_total = btf_data_size - hdr->hdr_len; | |
a2889a4c | 4653 | for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) { |
f80442a4 MKL |
4654 | if (expected_total < secs[i].off) { |
4655 | btf_verifier_log(env, "Invalid section offset"); | |
4656 | return -EINVAL; | |
4657 | } | |
4658 | if (total < secs[i].off) { | |
4659 | /* gap */ | |
4660 | btf_verifier_log(env, "Unsupported section found"); | |
4661 | return -EINVAL; | |
4662 | } | |
4663 | if (total > secs[i].off) { | |
4664 | btf_verifier_log(env, "Section overlap found"); | |
4665 | return -EINVAL; | |
4666 | } | |
4667 | if (expected_total - total < secs[i].len) { | |
4668 | btf_verifier_log(env, | |
4669 | "Total section length too long"); | |
4670 | return -EINVAL; | |
4671 | } | |
4672 | total += secs[i].len; | |
4673 | } | |
4674 | ||
4675 | /* There is data other than hdr and known sections */ | |
4676 | if (expected_total != total) { | |
4677 | btf_verifier_log(env, "Unsupported section found"); | |
4678 | return -EINVAL; | |
4679 | } | |
4680 | ||
4681 | return 0; | |
4682 | } | |
4683 | ||
4a6998af | 4684 | static int btf_parse_hdr(struct btf_verifier_env *env) |
f80442a4 | 4685 | { |
4a6998af | 4686 | u32 hdr_len, hdr_copy, btf_data_size; |
f80442a4 | 4687 | const struct btf_header *hdr; |
f80442a4 MKL |
4688 | struct btf *btf; |
4689 | int err; | |
69b693f0 | 4690 | |
f80442a4 | 4691 | btf = env->btf; |
4a6998af | 4692 | btf_data_size = btf->data_size; |
f80442a4 | 4693 | |
583669ab | 4694 | if (btf_data_size < offsetofend(struct btf_header, hdr_len)) { |
f80442a4 MKL |
4695 | btf_verifier_log(env, "hdr_len not found"); |
4696 | return -EINVAL; | |
4697 | } | |
4698 | ||
4a6998af ML |
4699 | hdr = btf->data; |
4700 | hdr_len = hdr->hdr_len; | |
f80442a4 | 4701 | if (btf_data_size < hdr_len) { |
69b693f0 MKL |
4702 | btf_verifier_log(env, "btf_header not found"); |
4703 | return -EINVAL; | |
4704 | } | |
4705 | ||
4a6998af ML |
4706 | /* Ensure the unsupported header fields are zero */ |
4707 | if (hdr_len > sizeof(btf->hdr)) { | |
4708 | u8 *expected_zero = btf->data + sizeof(btf->hdr); | |
4709 | u8 *end = btf->data + hdr_len; | |
4710 | ||
4711 | for (; expected_zero < end; expected_zero++) { | |
4712 | if (*expected_zero) { | |
4713 | btf_verifier_log(env, "Unsupported btf_header"); | |
4714 | return -E2BIG; | |
4715 | } | |
4716 | } | |
f80442a4 MKL |
4717 | } |
4718 | ||
4719 | hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr)); | |
4a6998af | 4720 | memcpy(&btf->hdr, btf->data, hdr_copy); |
f80442a4 MKL |
4721 | |
4722 | hdr = &btf->hdr; | |
4723 | ||
4724 | btf_verifier_log_hdr(env, btf_data_size); | |
69b693f0 | 4725 | |
69b693f0 MKL |
4726 | if (hdr->magic != BTF_MAGIC) { |
4727 | btf_verifier_log(env, "Invalid magic"); | |
4728 | return -EINVAL; | |
4729 | } | |
4730 | ||
4731 | if (hdr->version != BTF_VERSION) { | |
4732 | btf_verifier_log(env, "Unsupported version"); | |
4733 | return -ENOTSUPP; | |
4734 | } | |
4735 | ||
4736 | if (hdr->flags) { | |
4737 | btf_verifier_log(env, "Unsupported flags"); | |
4738 | return -ENOTSUPP; | |
4739 | } | |
4740 | ||
bcc5e616 | 4741 | if (!btf->base_btf && btf_data_size == hdr->hdr_len) { |
69b693f0 MKL |
4742 | btf_verifier_log(env, "No data"); |
4743 | return -EINVAL; | |
4744 | } | |
4745 | ||
f80442a4 MKL |
4746 | err = btf_check_sec_info(env, btf_data_size); |
4747 | if (err) | |
4748 | return err; | |
69b693f0 MKL |
4749 | |
4750 | return 0; | |
4751 | } | |
4752 | ||
eb596b09 KKD |
4753 | static int btf_check_type_tags(struct btf_verifier_env *env, |
4754 | struct btf *btf, int start_id) | |
4755 | { | |
4756 | int i, n, good_id = start_id - 1; | |
4757 | bool in_tags; | |
4758 | ||
4759 | n = btf_nr_types(btf); | |
4760 | for (i = start_id; i < n; i++) { | |
4761 | const struct btf_type *t; | |
4762 | u32 cur_id = i; | |
4763 | ||
4764 | t = btf_type_by_id(btf, i); | |
4765 | if (!t) | |
4766 | return -EINVAL; | |
4767 | if (!btf_type_is_modifier(t)) | |
4768 | continue; | |
4769 | ||
4770 | cond_resched(); | |
4771 | ||
4772 | in_tags = btf_type_is_type_tag(t); | |
4773 | while (btf_type_is_modifier(t)) { | |
4774 | if (btf_type_is_type_tag(t)) { | |
4775 | if (!in_tags) { | |
4776 | btf_verifier_log(env, "Type tags don't precede modifiers"); | |
4777 | return -EINVAL; | |
4778 | } | |
4779 | } else if (in_tags) { | |
4780 | in_tags = false; | |
4781 | } | |
4782 | if (cur_id <= good_id) | |
4783 | break; | |
4784 | /* Move to next type */ | |
4785 | cur_id = t->type; | |
4786 | t = btf_type_by_id(btf, cur_id); | |
4787 | if (!t) | |
4788 | return -EINVAL; | |
4789 | } | |
4790 | good_id = i; | |
4791 | } | |
4792 | return 0; | |
4793 | } | |
4794 | ||
c571bd75 | 4795 | static struct btf *btf_parse(bpfptr_t btf_data, u32 btf_data_size, |
69b693f0 MKL |
4796 | u32 log_level, char __user *log_ubuf, u32 log_size) |
4797 | { | |
4798 | struct btf_verifier_env *env = NULL; | |
4799 | struct bpf_verifier_log *log; | |
4800 | struct btf *btf = NULL; | |
4801 | u8 *data; | |
4802 | int err; | |
4803 | ||
4804 | if (btf_data_size > BTF_MAX_SIZE) | |
4805 | return ERR_PTR(-E2BIG); | |
4806 | ||
4807 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
4808 | if (!env) | |
4809 | return ERR_PTR(-ENOMEM); | |
4810 | ||
4811 | log = &env->log; | |
4812 | if (log_level || log_ubuf || log_size) { | |
4813 | /* user requested verbose verifier output | |
4814 | * and supplied buffer to store the verification trace | |
4815 | */ | |
4816 | log->level = log_level; | |
4817 | log->ubuf = log_ubuf; | |
4818 | log->len_total = log_size; | |
4819 | ||
4820 | /* log attributes have to be sane */ | |
866de407 | 4821 | if (!bpf_verifier_log_attr_valid(log)) { |
69b693f0 MKL |
4822 | err = -EINVAL; |
4823 | goto errout; | |
4824 | } | |
4825 | } | |
4826 | ||
4827 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
4828 | if (!btf) { | |
4829 | err = -ENOMEM; | |
4830 | goto errout; | |
4831 | } | |
f80442a4 MKL |
4832 | env->btf = btf; |
4833 | ||
69b693f0 MKL |
4834 | data = kvmalloc(btf_data_size, GFP_KERNEL | __GFP_NOWARN); |
4835 | if (!data) { | |
4836 | err = -ENOMEM; | |
4837 | goto errout; | |
4838 | } | |
4839 | ||
4840 | btf->data = data; | |
4841 | btf->data_size = btf_data_size; | |
4842 | ||
c571bd75 | 4843 | if (copy_from_bpfptr(data, btf_data, btf_data_size)) { |
69b693f0 MKL |
4844 | err = -EFAULT; |
4845 | goto errout; | |
4846 | } | |
4847 | ||
4a6998af ML |
4848 | err = btf_parse_hdr(env); |
4849 | if (err) | |
4850 | goto errout; | |
4851 | ||
4852 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
4853 | ||
69b693f0 MKL |
4854 | err = btf_parse_str_sec(env); |
4855 | if (err) | |
4856 | goto errout; | |
4857 | ||
4858 | err = btf_parse_type_sec(env); | |
4859 | if (err) | |
4860 | goto errout; | |
4861 | ||
eb596b09 KKD |
4862 | err = btf_check_type_tags(env, btf, 1); |
4863 | if (err) | |
4864 | goto errout; | |
4865 | ||
f80442a4 | 4866 | if (log->level && bpf_verifier_log_full(log)) { |
69b693f0 MKL |
4867 | err = -ENOSPC; |
4868 | goto errout; | |
4869 | } | |
4870 | ||
f80442a4 MKL |
4871 | btf_verifier_env_free(env); |
4872 | refcount_set(&btf->refcnt, 1); | |
4873 | return btf; | |
69b693f0 MKL |
4874 | |
4875 | errout: | |
4876 | btf_verifier_env_free(env); | |
4877 | if (btf) | |
4878 | btf_free(btf); | |
4879 | return ERR_PTR(err); | |
4880 | } | |
b00b8dae | 4881 | |
90ceddcb FS |
4882 | extern char __weak __start_BTF[]; |
4883 | extern char __weak __stop_BTF[]; | |
91cc1a99 AS |
4884 | extern struct btf *btf_vmlinux; |
4885 | ||
4886 | #define BPF_MAP_TYPE(_id, _ops) | |
f2e10bff | 4887 | #define BPF_LINK_TYPE(_id, _name) |
91cc1a99 AS |
4888 | static union { |
4889 | struct bpf_ctx_convert { | |
4890 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
4891 | prog_ctx_type _id##_prog; \ | |
4892 | kern_ctx_type _id##_kern; | |
4893 | #include <linux/bpf_types.h> | |
4894 | #undef BPF_PROG_TYPE | |
4895 | } *__t; | |
4896 | /* 't' is written once under lock. Read many times. */ | |
4897 | const struct btf_type *t; | |
4898 | } bpf_ctx_convert; | |
4899 | enum { | |
4900 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
4901 | __ctx_convert##_id, | |
4902 | #include <linux/bpf_types.h> | |
4903 | #undef BPF_PROG_TYPE | |
ce27709b | 4904 | __ctx_convert_unused, /* to avoid empty enum in extreme .config */ |
91cc1a99 AS |
4905 | }; |
4906 | static u8 bpf_ctx_convert_map[] = { | |
4907 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
4908 | [_id] = __ctx_convert##_id, | |
4909 | #include <linux/bpf_types.h> | |
4910 | #undef BPF_PROG_TYPE | |
4c80c7bc | 4911 | 0, /* avoid empty array */ |
91cc1a99 AS |
4912 | }; |
4913 | #undef BPF_MAP_TYPE | |
f2e10bff | 4914 | #undef BPF_LINK_TYPE |
91cc1a99 AS |
4915 | |
4916 | static const struct btf_member * | |
34747c41 | 4917 | btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf, |
51c39bb1 AS |
4918 | const struct btf_type *t, enum bpf_prog_type prog_type, |
4919 | int arg) | |
91cc1a99 AS |
4920 | { |
4921 | const struct btf_type *conv_struct; | |
4922 | const struct btf_type *ctx_struct; | |
4923 | const struct btf_member *ctx_type; | |
4924 | const char *tname, *ctx_tname; | |
4925 | ||
4926 | conv_struct = bpf_ctx_convert.t; | |
4927 | if (!conv_struct) { | |
4928 | bpf_log(log, "btf_vmlinux is malformed\n"); | |
4929 | return NULL; | |
4930 | } | |
4931 | t = btf_type_by_id(btf, t->type); | |
4932 | while (btf_type_is_modifier(t)) | |
4933 | t = btf_type_by_id(btf, t->type); | |
4934 | if (!btf_type_is_struct(t)) { | |
4935 | /* Only pointer to struct is supported for now. | |
4936 | * That means that BPF_PROG_TYPE_TRACEPOINT with BTF | |
4937 | * is not supported yet. | |
4938 | * BPF_PROG_TYPE_RAW_TRACEPOINT is fine. | |
4939 | */ | |
91cc1a99 AS |
4940 | return NULL; |
4941 | } | |
4942 | tname = btf_name_by_offset(btf, t->name_off); | |
4943 | if (!tname) { | |
51c39bb1 | 4944 | bpf_log(log, "arg#%d struct doesn't have a name\n", arg); |
91cc1a99 AS |
4945 | return NULL; |
4946 | } | |
4947 | /* prog_type is valid bpf program type. No need for bounds check. */ | |
4948 | ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2; | |
4949 | /* ctx_struct is a pointer to prog_ctx_type in vmlinux. | |
4950 | * Like 'struct __sk_buff' | |
4951 | */ | |
4952 | ctx_struct = btf_type_by_id(btf_vmlinux, ctx_type->type); | |
4953 | if (!ctx_struct) | |
4954 | /* should not happen */ | |
4955 | return NULL; | |
4956 | ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_struct->name_off); | |
4957 | if (!ctx_tname) { | |
4958 | /* should not happen */ | |
4959 | bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n"); | |
4960 | return NULL; | |
4961 | } | |
4962 | /* only compare that prog's ctx type name is the same as | |
4963 | * kernel expects. No need to compare field by field. | |
4964 | * It's ok for bpf prog to do: | |
4965 | * struct __sk_buff {}; | |
4966 | * int socket_filter_bpf_prog(struct __sk_buff *skb) | |
4967 | * { // no fields of skb are ever used } | |
4968 | */ | |
4969 | if (strcmp(ctx_tname, tname)) | |
4970 | return NULL; | |
4971 | return ctx_type; | |
4972 | } | |
8580ac94 | 4973 | |
41c48f3a AI |
4974 | static const struct bpf_map_ops * const btf_vmlinux_map_ops[] = { |
4975 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) | |
4976 | #define BPF_LINK_TYPE(_id, _name) | |
4977 | #define BPF_MAP_TYPE(_id, _ops) \ | |
4978 | [_id] = &_ops, | |
4979 | #include <linux/bpf_types.h> | |
4980 | #undef BPF_PROG_TYPE | |
4981 | #undef BPF_LINK_TYPE | |
4982 | #undef BPF_MAP_TYPE | |
4983 | }; | |
4984 | ||
4985 | static int btf_vmlinux_map_ids_init(const struct btf *btf, | |
4986 | struct bpf_verifier_log *log) | |
4987 | { | |
4988 | const struct bpf_map_ops *ops; | |
4989 | int i, btf_id; | |
4990 | ||
4991 | for (i = 0; i < ARRAY_SIZE(btf_vmlinux_map_ops); ++i) { | |
4992 | ops = btf_vmlinux_map_ops[i]; | |
4993 | if (!ops || (!ops->map_btf_name && !ops->map_btf_id)) | |
4994 | continue; | |
4995 | if (!ops->map_btf_name || !ops->map_btf_id) { | |
4996 | bpf_log(log, "map type %d is misconfigured\n", i); | |
4997 | return -EINVAL; | |
4998 | } | |
4999 | btf_id = btf_find_by_name_kind(btf, ops->map_btf_name, | |
5000 | BTF_KIND_STRUCT); | |
5001 | if (btf_id < 0) | |
5002 | return btf_id; | |
5003 | *ops->map_btf_id = btf_id; | |
5004 | } | |
5005 | ||
5006 | return 0; | |
5007 | } | |
5008 | ||
5b92a28a AS |
5009 | static int btf_translate_to_vmlinux(struct bpf_verifier_log *log, |
5010 | struct btf *btf, | |
5011 | const struct btf_type *t, | |
51c39bb1 AS |
5012 | enum bpf_prog_type prog_type, |
5013 | int arg) | |
5b92a28a AS |
5014 | { |
5015 | const struct btf_member *prog_ctx_type, *kern_ctx_type; | |
5016 | ||
51c39bb1 | 5017 | prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type, arg); |
5b92a28a AS |
5018 | if (!prog_ctx_type) |
5019 | return -ENOENT; | |
5020 | kern_ctx_type = prog_ctx_type + 1; | |
5021 | return kern_ctx_type->type; | |
5022 | } | |
5023 | ||
49f4e672 JO |
5024 | BTF_ID_LIST(bpf_ctx_convert_btf_id) |
5025 | BTF_ID(struct, bpf_ctx_convert) | |
5026 | ||
8580ac94 AS |
5027 | struct btf *btf_parse_vmlinux(void) |
5028 | { | |
5029 | struct btf_verifier_env *env = NULL; | |
5030 | struct bpf_verifier_log *log; | |
5031 | struct btf *btf = NULL; | |
49f4e672 | 5032 | int err; |
8580ac94 AS |
5033 | |
5034 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
5035 | if (!env) | |
5036 | return ERR_PTR(-ENOMEM); | |
5037 | ||
5038 | log = &env->log; | |
5039 | log->level = BPF_LOG_KERNEL; | |
5040 | ||
5041 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
5042 | if (!btf) { | |
5043 | err = -ENOMEM; | |
5044 | goto errout; | |
5045 | } | |
5046 | env->btf = btf; | |
5047 | ||
90ceddcb FS |
5048 | btf->data = __start_BTF; |
5049 | btf->data_size = __stop_BTF - __start_BTF; | |
53297220 AN |
5050 | btf->kernel_btf = true; |
5051 | snprintf(btf->name, sizeof(btf->name), "vmlinux"); | |
8580ac94 AS |
5052 | |
5053 | err = btf_parse_hdr(env); | |
5054 | if (err) | |
5055 | goto errout; | |
5056 | ||
5057 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
5058 | ||
5059 | err = btf_parse_str_sec(env); | |
5060 | if (err) | |
5061 | goto errout; | |
5062 | ||
5063 | err = btf_check_all_metas(env); | |
5064 | if (err) | |
5065 | goto errout; | |
5066 | ||
eb596b09 KKD |
5067 | err = btf_check_type_tags(env, btf, 1); |
5068 | if (err) | |
5069 | goto errout; | |
5070 | ||
a2d0d62f | 5071 | /* btf_parse_vmlinux() runs under bpf_verifier_lock */ |
49f4e672 | 5072 | bpf_ctx_convert.t = btf_type_by_id(btf, bpf_ctx_convert_btf_id[0]); |
91cc1a99 | 5073 | |
41c48f3a AI |
5074 | /* find bpf map structs for map_ptr access checking */ |
5075 | err = btf_vmlinux_map_ids_init(btf, log); | |
5076 | if (err < 0) | |
5077 | goto errout; | |
5078 | ||
d3e42bb0 | 5079 | bpf_struct_ops_init(btf, log); |
27ae7997 | 5080 | |
8580ac94 | 5081 | refcount_set(&btf->refcnt, 1); |
53297220 AN |
5082 | |
5083 | err = btf_alloc_id(btf); | |
5084 | if (err) | |
5085 | goto errout; | |
5086 | ||
5087 | btf_verifier_env_free(env); | |
8580ac94 AS |
5088 | return btf; |
5089 | ||
5090 | errout: | |
5091 | btf_verifier_env_free(env); | |
5092 | if (btf) { | |
5093 | kvfree(btf->types); | |
5094 | kfree(btf); | |
5095 | } | |
5096 | return ERR_PTR(err); | |
5097 | } | |
5098 | ||
7112d127 AN |
5099 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
5100 | ||
36e68442 AN |
5101 | static struct btf *btf_parse_module(const char *module_name, const void *data, unsigned int data_size) |
5102 | { | |
5103 | struct btf_verifier_env *env = NULL; | |
5104 | struct bpf_verifier_log *log; | |
5105 | struct btf *btf = NULL, *base_btf; | |
5106 | int err; | |
5107 | ||
5108 | base_btf = bpf_get_btf_vmlinux(); | |
5109 | if (IS_ERR(base_btf)) | |
5110 | return base_btf; | |
5111 | if (!base_btf) | |
5112 | return ERR_PTR(-EINVAL); | |
5113 | ||
5114 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
5115 | if (!env) | |
5116 | return ERR_PTR(-ENOMEM); | |
5117 | ||
5118 | log = &env->log; | |
5119 | log->level = BPF_LOG_KERNEL; | |
5120 | ||
5121 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
5122 | if (!btf) { | |
5123 | err = -ENOMEM; | |
5124 | goto errout; | |
5125 | } | |
5126 | env->btf = btf; | |
5127 | ||
5128 | btf->base_btf = base_btf; | |
5129 | btf->start_id = base_btf->nr_types; | |
5130 | btf->start_str_off = base_btf->hdr.str_len; | |
5131 | btf->kernel_btf = true; | |
5132 | snprintf(btf->name, sizeof(btf->name), "%s", module_name); | |
5133 | ||
5134 | btf->data = kvmalloc(data_size, GFP_KERNEL | __GFP_NOWARN); | |
5135 | if (!btf->data) { | |
5136 | err = -ENOMEM; | |
5137 | goto errout; | |
5138 | } | |
5139 | memcpy(btf->data, data, data_size); | |
5140 | btf->data_size = data_size; | |
5141 | ||
5142 | err = btf_parse_hdr(env); | |
5143 | if (err) | |
5144 | goto errout; | |
5145 | ||
5146 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
5147 | ||
5148 | err = btf_parse_str_sec(env); | |
5149 | if (err) | |
5150 | goto errout; | |
5151 | ||
5152 | err = btf_check_all_metas(env); | |
5153 | if (err) | |
5154 | goto errout; | |
5155 | ||
eb596b09 KKD |
5156 | err = btf_check_type_tags(env, btf, btf_nr_types(base_btf)); |
5157 | if (err) | |
5158 | goto errout; | |
5159 | ||
36e68442 AN |
5160 | btf_verifier_env_free(env); |
5161 | refcount_set(&btf->refcnt, 1); | |
5162 | return btf; | |
5163 | ||
5164 | errout: | |
5165 | btf_verifier_env_free(env); | |
5166 | if (btf) { | |
5167 | kvfree(btf->data); | |
5168 | kvfree(btf->types); | |
5169 | kfree(btf); | |
5170 | } | |
5171 | return ERR_PTR(err); | |
5172 | } | |
5173 | ||
7112d127 AN |
5174 | #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */ |
5175 | ||
5b92a28a AS |
5176 | struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog) |
5177 | { | |
3aac1ead | 5178 | struct bpf_prog *tgt_prog = prog->aux->dst_prog; |
5b92a28a | 5179 | |
22dc4a0f | 5180 | if (tgt_prog) |
5b92a28a | 5181 | return tgt_prog->aux->btf; |
22dc4a0f AN |
5182 | else |
5183 | return prog->aux->attach_btf; | |
5b92a28a AS |
5184 | } |
5185 | ||
bb6728d7 | 5186 | static bool is_int_ptr(struct btf *btf, const struct btf_type *t) |
84ad7a7a JO |
5187 | { |
5188 | /* t comes in already as a pointer */ | |
5189 | t = btf_type_by_id(btf, t->type); | |
5190 | ||
5191 | /* allow const */ | |
5192 | if (BTF_INFO_KIND(t->info) == BTF_KIND_CONST) | |
5193 | t = btf_type_by_id(btf, t->type); | |
5194 | ||
bb6728d7 | 5195 | return btf_type_is_int(t); |
84ad7a7a JO |
5196 | } |
5197 | ||
9e15db66 AS |
5198 | bool btf_ctx_access(int off, int size, enum bpf_access_type type, |
5199 | const struct bpf_prog *prog, | |
5200 | struct bpf_insn_access_aux *info) | |
5201 | { | |
38207291 | 5202 | const struct btf_type *t = prog->aux->attach_func_proto; |
3aac1ead | 5203 | struct bpf_prog *tgt_prog = prog->aux->dst_prog; |
5b92a28a | 5204 | struct btf *btf = bpf_prog_get_target_btf(prog); |
38207291 | 5205 | const char *tname = prog->aux->attach_func_name; |
9e15db66 | 5206 | struct bpf_verifier_log *log = info->log; |
9e15db66 | 5207 | const struct btf_param *args; |
c6f1bfe8 | 5208 | const char *tag_value; |
9e15db66 | 5209 | u32 nr_args, arg; |
3c32cc1b | 5210 | int i, ret; |
9e15db66 | 5211 | |
9e15db66 | 5212 | if (off % 8) { |
38207291 | 5213 | bpf_log(log, "func '%s' offset %d is not multiple of 8\n", |
9e15db66 AS |
5214 | tname, off); |
5215 | return false; | |
5216 | } | |
5217 | arg = off / 8; | |
5218 | args = (const struct btf_param *)(t + 1); | |
523a4cf4 DB |
5219 | /* if (t == NULL) Fall back to default BPF prog with |
5220 | * MAX_BPF_FUNC_REG_ARGS u64 arguments. | |
5221 | */ | |
5222 | nr_args = t ? btf_type_vlen(t) : MAX_BPF_FUNC_REG_ARGS; | |
38207291 MKL |
5223 | if (prog->aux->attach_btf_trace) { |
5224 | /* skip first 'void *__data' argument in btf_trace_##name typedef */ | |
5225 | args++; | |
5226 | nr_args--; | |
5227 | } | |
fec56f58 | 5228 | |
f50b49a0 KS |
5229 | if (arg > nr_args) { |
5230 | bpf_log(log, "func '%s' doesn't have %d-th argument\n", | |
5231 | tname, arg + 1); | |
5232 | return false; | |
5233 | } | |
5234 | ||
6ba43b76 | 5235 | if (arg == nr_args) { |
f50b49a0 KS |
5236 | switch (prog->expected_attach_type) { |
5237 | case BPF_LSM_MAC: | |
5238 | case BPF_TRACE_FEXIT: | |
9e4e01df KS |
5239 | /* When LSM programs are attached to void LSM hooks |
5240 | * they use FEXIT trampolines and when attached to | |
5241 | * int LSM hooks, they use MODIFY_RETURN trampolines. | |
5242 | * | |
5243 | * While the LSM programs are BPF_MODIFY_RETURN-like | |
5244 | * the check: | |
5245 | * | |
5246 | * if (ret_type != 'int') | |
5247 | * return -EINVAL; | |
5248 | * | |
5249 | * is _not_ done here. This is still safe as LSM hooks | |
5250 | * have only void and int return types. | |
5251 | */ | |
6ba43b76 KS |
5252 | if (!t) |
5253 | return true; | |
5254 | t = btf_type_by_id(btf, t->type); | |
f50b49a0 KS |
5255 | break; |
5256 | case BPF_MODIFY_RETURN: | |
6ba43b76 KS |
5257 | /* For now the BPF_MODIFY_RETURN can only be attached to |
5258 | * functions that return an int. | |
5259 | */ | |
5260 | if (!t) | |
5261 | return false; | |
5262 | ||
5263 | t = btf_type_skip_modifiers(btf, t->type, NULL); | |
a9b59159 | 5264 | if (!btf_type_is_small_int(t)) { |
6ba43b76 KS |
5265 | bpf_log(log, |
5266 | "ret type %s not allowed for fmod_ret\n", | |
5267 | btf_kind_str[BTF_INFO_KIND(t->info)]); | |
5268 | return false; | |
5269 | } | |
f50b49a0 KS |
5270 | break; |
5271 | default: | |
5272 | bpf_log(log, "func '%s' doesn't have %d-th argument\n", | |
5273 | tname, arg + 1); | |
5274 | return false; | |
6ba43b76 | 5275 | } |
fec56f58 | 5276 | } else { |
5b92a28a | 5277 | if (!t) |
523a4cf4 | 5278 | /* Default prog with MAX_BPF_FUNC_REG_ARGS args */ |
5b92a28a AS |
5279 | return true; |
5280 | t = btf_type_by_id(btf, args[arg].type); | |
9e15db66 | 5281 | } |
f50b49a0 | 5282 | |
9e15db66 AS |
5283 | /* skip modifiers */ |
5284 | while (btf_type_is_modifier(t)) | |
5b92a28a | 5285 | t = btf_type_by_id(btf, t->type); |
a9b59159 | 5286 | if (btf_type_is_small_int(t) || btf_type_is_enum(t)) |
9e15db66 AS |
5287 | /* accessing a scalar */ |
5288 | return true; | |
5289 | if (!btf_type_is_ptr(t)) { | |
5290 | bpf_log(log, | |
38207291 | 5291 | "func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n", |
9e15db66 | 5292 | tname, arg, |
5b92a28a | 5293 | __btf_name_by_offset(btf, t->name_off), |
9e15db66 AS |
5294 | btf_kind_str[BTF_INFO_KIND(t->info)]); |
5295 | return false; | |
5296 | } | |
afbf21dc YS |
5297 | |
5298 | /* check for PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL */ | |
5299 | for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { | |
5300 | const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; | |
c25b2ae1 | 5301 | u32 type, flag; |
afbf21dc | 5302 | |
c25b2ae1 HL |
5303 | type = base_type(ctx_arg_info->reg_type); |
5304 | flag = type_flag(ctx_arg_info->reg_type); | |
20b2aff4 | 5305 | if (ctx_arg_info->offset == off && type == PTR_TO_BUF && |
c25b2ae1 | 5306 | (flag & PTR_MAYBE_NULL)) { |
afbf21dc YS |
5307 | info->reg_type = ctx_arg_info->reg_type; |
5308 | return true; | |
5309 | } | |
5310 | } | |
5311 | ||
9e15db66 AS |
5312 | if (t->type == 0) |
5313 | /* This is a pointer to void. | |
5314 | * It is the same as scalar from the verifier safety pov. | |
5315 | * No further pointer walking is allowed. | |
5316 | */ | |
5317 | return true; | |
5318 | ||
bb6728d7 | 5319 | if (is_int_ptr(btf, t)) |
84ad7a7a JO |
5320 | return true; |
5321 | ||
9e15db66 | 5322 | /* this is a pointer to another type */ |
3c32cc1b YS |
5323 | for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { |
5324 | const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; | |
5325 | ||
5326 | if (ctx_arg_info->offset == off) { | |
d3621642 YS |
5327 | if (!ctx_arg_info->btf_id) { |
5328 | bpf_log(log,"invalid btf_id for context argument offset %u\n", off); | |
5329 | return false; | |
5330 | } | |
5331 | ||
3c32cc1b | 5332 | info->reg_type = ctx_arg_info->reg_type; |
22dc4a0f | 5333 | info->btf = btf_vmlinux; |
951cf368 YS |
5334 | info->btf_id = ctx_arg_info->btf_id; |
5335 | return true; | |
3c32cc1b YS |
5336 | } |
5337 | } | |
9e15db66 | 5338 | |
951cf368 | 5339 | info->reg_type = PTR_TO_BTF_ID; |
5b92a28a | 5340 | if (tgt_prog) { |
43bc2874 THJ |
5341 | enum bpf_prog_type tgt_type; |
5342 | ||
5343 | if (tgt_prog->type == BPF_PROG_TYPE_EXT) | |
5344 | tgt_type = tgt_prog->aux->saved_dst_prog_type; | |
5345 | else | |
5346 | tgt_type = tgt_prog->type; | |
5347 | ||
5348 | ret = btf_translate_to_vmlinux(log, btf, t, tgt_type, arg); | |
5b92a28a | 5349 | if (ret > 0) { |
22dc4a0f | 5350 | info->btf = btf_vmlinux; |
5b92a28a AS |
5351 | info->btf_id = ret; |
5352 | return true; | |
5353 | } else { | |
5354 | return false; | |
5355 | } | |
5356 | } | |
275517ff | 5357 | |
22dc4a0f | 5358 | info->btf = btf; |
275517ff | 5359 | info->btf_id = t->type; |
5b92a28a | 5360 | t = btf_type_by_id(btf, t->type); |
c6f1bfe8 YS |
5361 | |
5362 | if (btf_type_is_type_tag(t)) { | |
5363 | tag_value = __btf_name_by_offset(btf, t->name_off); | |
5364 | if (strcmp(tag_value, "user") == 0) | |
5365 | info->reg_type |= MEM_USER; | |
5844101a HL |
5366 | if (strcmp(tag_value, "percpu") == 0) |
5367 | info->reg_type |= MEM_PERCPU; | |
c6f1bfe8 YS |
5368 | } |
5369 | ||
9e15db66 | 5370 | /* skip modifiers */ |
275517ff MKL |
5371 | while (btf_type_is_modifier(t)) { |
5372 | info->btf_id = t->type; | |
5b92a28a | 5373 | t = btf_type_by_id(btf, t->type); |
275517ff | 5374 | } |
9e15db66 AS |
5375 | if (!btf_type_is_struct(t)) { |
5376 | bpf_log(log, | |
38207291 | 5377 | "func '%s' arg%d type %s is not a struct\n", |
9e15db66 AS |
5378 | tname, arg, btf_kind_str[BTF_INFO_KIND(t->info)]); |
5379 | return false; | |
5380 | } | |
38207291 | 5381 | bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n", |
9e15db66 | 5382 | tname, arg, info->btf_id, btf_kind_str[BTF_INFO_KIND(t->info)], |
5b92a28a | 5383 | __btf_name_by_offset(btf, t->name_off)); |
9e15db66 AS |
5384 | return true; |
5385 | } | |
5386 | ||
1c6d28a6 JO |
5387 | enum bpf_struct_walk_result { |
5388 | /* < 0 error */ | |
5389 | WALK_SCALAR = 0, | |
5390 | WALK_PTR, | |
5391 | WALK_STRUCT, | |
5392 | }; | |
5393 | ||
22dc4a0f | 5394 | static int btf_struct_walk(struct bpf_verifier_log *log, const struct btf *btf, |
1c6d28a6 | 5395 | const struct btf_type *t, int off, int size, |
c6f1bfe8 | 5396 | u32 *next_btf_id, enum bpf_type_flag *flag) |
9e15db66 | 5397 | { |
7e3617a7 MKL |
5398 | u32 i, moff, mtrue_end, msize = 0, total_nelems = 0; |
5399 | const struct btf_type *mtype, *elem_type = NULL; | |
9e15db66 | 5400 | const struct btf_member *member; |
c6f1bfe8 | 5401 | const char *tname, *mname, *tag_value; |
1c6d28a6 | 5402 | u32 vlen, elem_id, mid; |
9e15db66 AS |
5403 | |
5404 | again: | |
22dc4a0f | 5405 | tname = __btf_name_by_offset(btf, t->name_off); |
9e15db66 | 5406 | if (!btf_type_is_struct(t)) { |
275517ff | 5407 | bpf_log(log, "Type '%s' is not a struct\n", tname); |
9e15db66 AS |
5408 | return -EINVAL; |
5409 | } | |
5410 | ||
9c5f8a10 | 5411 | vlen = btf_type_vlen(t); |
976aba00 | 5412 | if (off + size > t->size) { |
9c5f8a10 YS |
5413 | /* If the last element is a variable size array, we may |
5414 | * need to relax the rule. | |
5415 | */ | |
5416 | struct btf_array *array_elem; | |
5417 | ||
5418 | if (vlen == 0) | |
5419 | goto error; | |
5420 | ||
5421 | member = btf_type_member(t) + vlen - 1; | |
22dc4a0f | 5422 | mtype = btf_type_skip_modifiers(btf, member->type, |
9c5f8a10 YS |
5423 | NULL); |
5424 | if (!btf_type_is_array(mtype)) | |
5425 | goto error; | |
5426 | ||
5427 | array_elem = (struct btf_array *)(mtype + 1); | |
5428 | if (array_elem->nelems != 0) | |
5429 | goto error; | |
5430 | ||
8293eb99 | 5431 | moff = __btf_member_bit_offset(t, member) / 8; |
9c5f8a10 YS |
5432 | if (off < moff) |
5433 | goto error; | |
5434 | ||
5435 | /* Only allow structure for now, can be relaxed for | |
5436 | * other types later. | |
5437 | */ | |
22dc4a0f | 5438 | t = btf_type_skip_modifiers(btf, array_elem->type, |
dafe58fc JO |
5439 | NULL); |
5440 | if (!btf_type_is_struct(t)) | |
9c5f8a10 YS |
5441 | goto error; |
5442 | ||
dafe58fc JO |
5443 | off = (off - moff) % t->size; |
5444 | goto again; | |
9c5f8a10 YS |
5445 | |
5446 | error: | |
976aba00 MKL |
5447 | bpf_log(log, "access beyond struct %s at off %u size %u\n", |
5448 | tname, off, size); | |
5449 | return -EACCES; | |
5450 | } | |
9e15db66 | 5451 | |
976aba00 | 5452 | for_each_member(i, t, member) { |
7e3617a7 | 5453 | /* offset of the field in bytes */ |
8293eb99 | 5454 | moff = __btf_member_bit_offset(t, member) / 8; |
7e3617a7 | 5455 | if (off + size <= moff) |
9e15db66 AS |
5456 | /* won't find anything, field is already too far */ |
5457 | break; | |
976aba00 | 5458 | |
8293eb99 AS |
5459 | if (__btf_member_bitfield_size(t, member)) { |
5460 | u32 end_bit = __btf_member_bit_offset(t, member) + | |
5461 | __btf_member_bitfield_size(t, member); | |
976aba00 MKL |
5462 | |
5463 | /* off <= moff instead of off == moff because clang | |
5464 | * does not generate a BTF member for anonymous | |
5465 | * bitfield like the ":16" here: | |
5466 | * struct { | |
5467 | * int :16; | |
5468 | * int x:8; | |
5469 | * }; | |
5470 | */ | |
5471 | if (off <= moff && | |
5472 | BITS_ROUNDUP_BYTES(end_bit) <= off + size) | |
1c6d28a6 | 5473 | return WALK_SCALAR; |
976aba00 MKL |
5474 | |
5475 | /* off may be accessing a following member | |
5476 | * | |
5477 | * or | |
5478 | * | |
5479 | * Doing partial access at either end of this | |
5480 | * bitfield. Continue on this case also to | |
5481 | * treat it as not accessing this bitfield | |
5482 | * and eventually error out as field not | |
5483 | * found to keep it simple. | |
5484 | * It could be relaxed if there was a legit | |
5485 | * partial access case later. | |
5486 | */ | |
5487 | continue; | |
5488 | } | |
5489 | ||
7e3617a7 MKL |
5490 | /* In case of "off" is pointing to holes of a struct */ |
5491 | if (off < moff) | |
976aba00 | 5492 | break; |
9e15db66 AS |
5493 | |
5494 | /* type of the field */ | |
1c6d28a6 | 5495 | mid = member->type; |
22dc4a0f AN |
5496 | mtype = btf_type_by_id(btf, member->type); |
5497 | mname = __btf_name_by_offset(btf, member->name_off); | |
9e15db66 | 5498 | |
22dc4a0f | 5499 | mtype = __btf_resolve_size(btf, mtype, &msize, |
1c6d28a6 JO |
5500 | &elem_type, &elem_id, &total_nelems, |
5501 | &mid); | |
7e3617a7 | 5502 | if (IS_ERR(mtype)) { |
9e15db66 AS |
5503 | bpf_log(log, "field %s doesn't have size\n", mname); |
5504 | return -EFAULT; | |
5505 | } | |
7e3617a7 MKL |
5506 | |
5507 | mtrue_end = moff + msize; | |
5508 | if (off >= mtrue_end) | |
9e15db66 AS |
5509 | /* no overlap with member, keep iterating */ |
5510 | continue; | |
7e3617a7 MKL |
5511 | |
5512 | if (btf_type_is_array(mtype)) { | |
5513 | u32 elem_idx; | |
5514 | ||
6298399b | 5515 | /* __btf_resolve_size() above helps to |
7e3617a7 MKL |
5516 | * linearize a multi-dimensional array. |
5517 | * | |
5518 | * The logic here is treating an array | |
5519 | * in a struct as the following way: | |
5520 | * | |
5521 | * struct outer { | |
5522 | * struct inner array[2][2]; | |
5523 | * }; | |
5524 | * | |
5525 | * looks like: | |
5526 | * | |
5527 | * struct outer { | |
5528 | * struct inner array_elem0; | |
5529 | * struct inner array_elem1; | |
5530 | * struct inner array_elem2; | |
5531 | * struct inner array_elem3; | |
5532 | * }; | |
5533 | * | |
5534 | * When accessing outer->array[1][0], it moves | |
5535 | * moff to "array_elem2", set mtype to | |
5536 | * "struct inner", and msize also becomes | |
5537 | * sizeof(struct inner). Then most of the | |
5538 | * remaining logic will fall through without | |
5539 | * caring the current member is an array or | |
5540 | * not. | |
5541 | * | |
5542 | * Unlike mtype/msize/moff, mtrue_end does not | |
5543 | * change. The naming difference ("_true") tells | |
5544 | * that it is not always corresponding to | |
5545 | * the current mtype/msize/moff. | |
5546 | * It is the true end of the current | |
5547 | * member (i.e. array in this case). That | |
5548 | * will allow an int array to be accessed like | |
5549 | * a scratch space, | |
5550 | * i.e. allow access beyond the size of | |
5551 | * the array's element as long as it is | |
5552 | * within the mtrue_end boundary. | |
5553 | */ | |
5554 | ||
5555 | /* skip empty array */ | |
5556 | if (moff == mtrue_end) | |
5557 | continue; | |
5558 | ||
5559 | msize /= total_nelems; | |
5560 | elem_idx = (off - moff) / msize; | |
5561 | moff += elem_idx * msize; | |
5562 | mtype = elem_type; | |
1c6d28a6 | 5563 | mid = elem_id; |
7e3617a7 MKL |
5564 | } |
5565 | ||
9e15db66 AS |
5566 | /* the 'off' we're looking for is either equal to start |
5567 | * of this field or inside of this struct | |
5568 | */ | |
5569 | if (btf_type_is_struct(mtype)) { | |
5570 | /* our field must be inside that union or struct */ | |
5571 | t = mtype; | |
5572 | ||
1c6d28a6 JO |
5573 | /* return if the offset matches the member offset */ |
5574 | if (off == moff) { | |
5575 | *next_btf_id = mid; | |
5576 | return WALK_STRUCT; | |
5577 | } | |
5578 | ||
9e15db66 | 5579 | /* adjust offset we're looking for */ |
7e3617a7 | 5580 | off -= moff; |
9e15db66 AS |
5581 | goto again; |
5582 | } | |
9e15db66 AS |
5583 | |
5584 | if (btf_type_is_ptr(mtype)) { | |
c6f1bfe8 YS |
5585 | const struct btf_type *stype, *t; |
5586 | enum bpf_type_flag tmp_flag = 0; | |
257af63d | 5587 | u32 id; |
9e15db66 | 5588 | |
7e3617a7 MKL |
5589 | if (msize != size || off != moff) { |
5590 | bpf_log(log, | |
5591 | "cannot access ptr member %s with moff %u in struct %s with off %u size %u\n", | |
5592 | mname, moff, tname, off, size); | |
5593 | return -EACCES; | |
5594 | } | |
c6f1bfe8 | 5595 | |
5844101a | 5596 | /* check type tag */ |
c6f1bfe8 YS |
5597 | t = btf_type_by_id(btf, mtype->type); |
5598 | if (btf_type_is_type_tag(t)) { | |
5599 | tag_value = __btf_name_by_offset(btf, t->name_off); | |
5844101a | 5600 | /* check __user tag */ |
c6f1bfe8 YS |
5601 | if (strcmp(tag_value, "user") == 0) |
5602 | tmp_flag = MEM_USER; | |
5844101a HL |
5603 | /* check __percpu tag */ |
5604 | if (strcmp(tag_value, "percpu") == 0) | |
5605 | tmp_flag = MEM_PERCPU; | |
c6f1bfe8 YS |
5606 | } |
5607 | ||
22dc4a0f | 5608 | stype = btf_type_skip_modifiers(btf, mtype->type, &id); |
9e15db66 | 5609 | if (btf_type_is_struct(stype)) { |
257af63d | 5610 | *next_btf_id = id; |
c6f1bfe8 | 5611 | *flag = tmp_flag; |
1c6d28a6 | 5612 | return WALK_PTR; |
9e15db66 AS |
5613 | } |
5614 | } | |
7e3617a7 MKL |
5615 | |
5616 | /* Allow more flexible access within an int as long as | |
5617 | * it is within mtrue_end. | |
5618 | * Since mtrue_end could be the end of an array, | |
5619 | * that also allows using an array of int as a scratch | |
5620 | * space. e.g. skb->cb[]. | |
5621 | */ | |
5622 | if (off + size > mtrue_end) { | |
5623 | bpf_log(log, | |
5624 | "access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n", | |
5625 | mname, mtrue_end, tname, off, size); | |
5626 | return -EACCES; | |
5627 | } | |
5628 | ||
1c6d28a6 | 5629 | return WALK_SCALAR; |
9e15db66 AS |
5630 | } |
5631 | bpf_log(log, "struct %s doesn't have field at offset %d\n", tname, off); | |
5632 | return -EINVAL; | |
5633 | } | |
5634 | ||
22dc4a0f | 5635 | int btf_struct_access(struct bpf_verifier_log *log, const struct btf *btf, |
1c6d28a6 JO |
5636 | const struct btf_type *t, int off, int size, |
5637 | enum bpf_access_type atype __maybe_unused, | |
c6f1bfe8 | 5638 | u32 *next_btf_id, enum bpf_type_flag *flag) |
1c6d28a6 | 5639 | { |
c6f1bfe8 | 5640 | enum bpf_type_flag tmp_flag = 0; |
1c6d28a6 JO |
5641 | int err; |
5642 | u32 id; | |
5643 | ||
5644 | do { | |
c6f1bfe8 | 5645 | err = btf_struct_walk(log, btf, t, off, size, &id, &tmp_flag); |
1c6d28a6 JO |
5646 | |
5647 | switch (err) { | |
5648 | case WALK_PTR: | |
5649 | /* If we found the pointer or scalar on t+off, | |
5650 | * we're done. | |
5651 | */ | |
5652 | *next_btf_id = id; | |
c6f1bfe8 | 5653 | *flag = tmp_flag; |
1c6d28a6 JO |
5654 | return PTR_TO_BTF_ID; |
5655 | case WALK_SCALAR: | |
5656 | return SCALAR_VALUE; | |
5657 | case WALK_STRUCT: | |
5658 | /* We found nested struct, so continue the search | |
5659 | * by diving in it. At this point the offset is | |
5660 | * aligned with the new type, so set it to 0. | |
5661 | */ | |
22dc4a0f | 5662 | t = btf_type_by_id(btf, id); |
1c6d28a6 JO |
5663 | off = 0; |
5664 | break; | |
5665 | default: | |
5666 | /* It's either error or unknown return value.. | |
5667 | * scream and leave. | |
5668 | */ | |
5669 | if (WARN_ONCE(err > 0, "unknown btf_struct_walk return value")) | |
5670 | return -EINVAL; | |
5671 | return err; | |
5672 | } | |
5673 | } while (t); | |
5674 | ||
5675 | return -EINVAL; | |
5676 | } | |
5677 | ||
22dc4a0f AN |
5678 | /* Check that two BTF types, each specified as an BTF object + id, are exactly |
5679 | * the same. Trivial ID check is not enough due to module BTFs, because we can | |
5680 | * end up with two different module BTFs, but IDs point to the common type in | |
5681 | * vmlinux BTF. | |
5682 | */ | |
5683 | static bool btf_types_are_same(const struct btf *btf1, u32 id1, | |
5684 | const struct btf *btf2, u32 id2) | |
5685 | { | |
5686 | if (id1 != id2) | |
5687 | return false; | |
5688 | if (btf1 == btf2) | |
5689 | return true; | |
5690 | return btf_type_by_id(btf1, id1) == btf_type_by_id(btf2, id2); | |
5691 | } | |
5692 | ||
faaf4a79 | 5693 | bool btf_struct_ids_match(struct bpf_verifier_log *log, |
22dc4a0f AN |
5694 | const struct btf *btf, u32 id, int off, |
5695 | const struct btf *need_btf, u32 need_type_id) | |
faaf4a79 JO |
5696 | { |
5697 | const struct btf_type *type; | |
c6f1bfe8 | 5698 | enum bpf_type_flag flag; |
faaf4a79 JO |
5699 | int err; |
5700 | ||
5701 | /* Are we already done? */ | |
22dc4a0f | 5702 | if (off == 0 && btf_types_are_same(btf, id, need_btf, need_type_id)) |
faaf4a79 JO |
5703 | return true; |
5704 | ||
5705 | again: | |
22dc4a0f | 5706 | type = btf_type_by_id(btf, id); |
faaf4a79 JO |
5707 | if (!type) |
5708 | return false; | |
c6f1bfe8 | 5709 | err = btf_struct_walk(log, btf, type, off, 1, &id, &flag); |
faaf4a79 JO |
5710 | if (err != WALK_STRUCT) |
5711 | return false; | |
5712 | ||
5713 | /* We found nested struct object. If it matches | |
5714 | * the requested ID, we're done. Otherwise let's | |
5715 | * continue the search with offset 0 in the new | |
5716 | * type. | |
5717 | */ | |
22dc4a0f | 5718 | if (!btf_types_are_same(btf, id, need_btf, need_type_id)) { |
faaf4a79 JO |
5719 | off = 0; |
5720 | goto again; | |
5721 | } | |
5722 | ||
5723 | return true; | |
5724 | } | |
5725 | ||
fec56f58 AS |
5726 | static int __get_type_size(struct btf *btf, u32 btf_id, |
5727 | const struct btf_type **bad_type) | |
5728 | { | |
5729 | const struct btf_type *t; | |
5730 | ||
5731 | if (!btf_id) | |
5732 | /* void */ | |
5733 | return 0; | |
5734 | t = btf_type_by_id(btf, btf_id); | |
5735 | while (t && btf_type_is_modifier(t)) | |
5736 | t = btf_type_by_id(btf, t->type); | |
d0f01043 | 5737 | if (!t) { |
951bb646 | 5738 | *bad_type = btf_type_by_id(btf, 0); |
fec56f58 | 5739 | return -EINVAL; |
d0f01043 | 5740 | } |
fec56f58 AS |
5741 | if (btf_type_is_ptr(t)) |
5742 | /* kernel size of pointer. Not BPF's size of pointer*/ | |
5743 | return sizeof(void *); | |
5744 | if (btf_type_is_int(t) || btf_type_is_enum(t)) | |
5745 | return t->size; | |
5746 | *bad_type = t; | |
5747 | return -EINVAL; | |
5748 | } | |
5749 | ||
5750 | int btf_distill_func_proto(struct bpf_verifier_log *log, | |
5751 | struct btf *btf, | |
5752 | const struct btf_type *func, | |
5753 | const char *tname, | |
5754 | struct btf_func_model *m) | |
5755 | { | |
5756 | const struct btf_param *args; | |
5757 | const struct btf_type *t; | |
5758 | u32 i, nargs; | |
5759 | int ret; | |
5760 | ||
5b92a28a AS |
5761 | if (!func) { |
5762 | /* BTF function prototype doesn't match the verifier types. | |
523a4cf4 | 5763 | * Fall back to MAX_BPF_FUNC_REG_ARGS u64 args. |
5b92a28a | 5764 | */ |
523a4cf4 | 5765 | for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++) |
5b92a28a AS |
5766 | m->arg_size[i] = 8; |
5767 | m->ret_size = 8; | |
523a4cf4 | 5768 | m->nr_args = MAX_BPF_FUNC_REG_ARGS; |
5b92a28a AS |
5769 | return 0; |
5770 | } | |
fec56f58 AS |
5771 | args = (const struct btf_param *)(func + 1); |
5772 | nargs = btf_type_vlen(func); | |
c29a4920 | 5773 | if (nargs > MAX_BPF_FUNC_ARGS) { |
fec56f58 AS |
5774 | bpf_log(log, |
5775 | "The function %s has %d arguments. Too many.\n", | |
5776 | tname, nargs); | |
5777 | return -EINVAL; | |
5778 | } | |
5779 | ret = __get_type_size(btf, func->type, &t); | |
5780 | if (ret < 0) { | |
5781 | bpf_log(log, | |
5782 | "The function %s return type %s is unsupported.\n", | |
5783 | tname, btf_kind_str[BTF_INFO_KIND(t->info)]); | |
5784 | return -EINVAL; | |
5785 | } | |
5786 | m->ret_size = ret; | |
5787 | ||
5788 | for (i = 0; i < nargs; i++) { | |
31379397 JO |
5789 | if (i == nargs - 1 && args[i].type == 0) { |
5790 | bpf_log(log, | |
5791 | "The function %s with variable args is unsupported.\n", | |
5792 | tname); | |
5793 | return -EINVAL; | |
5794 | } | |
fec56f58 AS |
5795 | ret = __get_type_size(btf, args[i].type, &t); |
5796 | if (ret < 0) { | |
5797 | bpf_log(log, | |
5798 | "The function %s arg%d type %s is unsupported.\n", | |
5799 | tname, i, btf_kind_str[BTF_INFO_KIND(t->info)]); | |
5800 | return -EINVAL; | |
5801 | } | |
31379397 JO |
5802 | if (ret == 0) { |
5803 | bpf_log(log, | |
5804 | "The function %s has malformed void argument.\n", | |
5805 | tname); | |
5806 | return -EINVAL; | |
5807 | } | |
fec56f58 AS |
5808 | m->arg_size[i] = ret; |
5809 | } | |
5810 | m->nr_args = nargs; | |
5811 | return 0; | |
5812 | } | |
5813 | ||
be8704ff AS |
5814 | /* Compare BTFs of two functions assuming only scalars and pointers to context. |
5815 | * t1 points to BTF_KIND_FUNC in btf1 | |
5816 | * t2 points to BTF_KIND_FUNC in btf2 | |
5817 | * Returns: | |
5818 | * EINVAL - function prototype mismatch | |
5819 | * EFAULT - verifier bug | |
5820 | * 0 - 99% match. The last 1% is validated by the verifier. | |
5821 | */ | |
2bf0eb9b HY |
5822 | static int btf_check_func_type_match(struct bpf_verifier_log *log, |
5823 | struct btf *btf1, const struct btf_type *t1, | |
5824 | struct btf *btf2, const struct btf_type *t2) | |
be8704ff AS |
5825 | { |
5826 | const struct btf_param *args1, *args2; | |
5827 | const char *fn1, *fn2, *s1, *s2; | |
5828 | u32 nargs1, nargs2, i; | |
5829 | ||
5830 | fn1 = btf_name_by_offset(btf1, t1->name_off); | |
5831 | fn2 = btf_name_by_offset(btf2, t2->name_off); | |
5832 | ||
5833 | if (btf_func_linkage(t1) != BTF_FUNC_GLOBAL) { | |
5834 | bpf_log(log, "%s() is not a global function\n", fn1); | |
5835 | return -EINVAL; | |
5836 | } | |
5837 | if (btf_func_linkage(t2) != BTF_FUNC_GLOBAL) { | |
5838 | bpf_log(log, "%s() is not a global function\n", fn2); | |
5839 | return -EINVAL; | |
5840 | } | |
5841 | ||
5842 | t1 = btf_type_by_id(btf1, t1->type); | |
5843 | if (!t1 || !btf_type_is_func_proto(t1)) | |
5844 | return -EFAULT; | |
5845 | t2 = btf_type_by_id(btf2, t2->type); | |
5846 | if (!t2 || !btf_type_is_func_proto(t2)) | |
5847 | return -EFAULT; | |
5848 | ||
5849 | args1 = (const struct btf_param *)(t1 + 1); | |
5850 | nargs1 = btf_type_vlen(t1); | |
5851 | args2 = (const struct btf_param *)(t2 + 1); | |
5852 | nargs2 = btf_type_vlen(t2); | |
5853 | ||
5854 | if (nargs1 != nargs2) { | |
5855 | bpf_log(log, "%s() has %d args while %s() has %d args\n", | |
5856 | fn1, nargs1, fn2, nargs2); | |
5857 | return -EINVAL; | |
5858 | } | |
5859 | ||
5860 | t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); | |
5861 | t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); | |
5862 | if (t1->info != t2->info) { | |
5863 | bpf_log(log, | |
5864 | "Return type %s of %s() doesn't match type %s of %s()\n", | |
5865 | btf_type_str(t1), fn1, | |
5866 | btf_type_str(t2), fn2); | |
5867 | return -EINVAL; | |
5868 | } | |
5869 | ||
5870 | for (i = 0; i < nargs1; i++) { | |
5871 | t1 = btf_type_skip_modifiers(btf1, args1[i].type, NULL); | |
5872 | t2 = btf_type_skip_modifiers(btf2, args2[i].type, NULL); | |
5873 | ||
5874 | if (t1->info != t2->info) { | |
5875 | bpf_log(log, "arg%d in %s() is %s while %s() has %s\n", | |
5876 | i, fn1, btf_type_str(t1), | |
5877 | fn2, btf_type_str(t2)); | |
5878 | return -EINVAL; | |
5879 | } | |
5880 | if (btf_type_has_size(t1) && t1->size != t2->size) { | |
5881 | bpf_log(log, | |
5882 | "arg%d in %s() has size %d while %s() has %d\n", | |
5883 | i, fn1, t1->size, | |
5884 | fn2, t2->size); | |
5885 | return -EINVAL; | |
5886 | } | |
5887 | ||
5888 | /* global functions are validated with scalars and pointers | |
5889 | * to context only. And only global functions can be replaced. | |
5890 | * Hence type check only those types. | |
5891 | */ | |
5892 | if (btf_type_is_int(t1) || btf_type_is_enum(t1)) | |
5893 | continue; | |
5894 | if (!btf_type_is_ptr(t1)) { | |
5895 | bpf_log(log, | |
5896 | "arg%d in %s() has unrecognized type\n", | |
5897 | i, fn1); | |
5898 | return -EINVAL; | |
5899 | } | |
5900 | t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); | |
5901 | t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); | |
5902 | if (!btf_type_is_struct(t1)) { | |
5903 | bpf_log(log, | |
5904 | "arg%d in %s() is not a pointer to context\n", | |
5905 | i, fn1); | |
5906 | return -EINVAL; | |
5907 | } | |
5908 | if (!btf_type_is_struct(t2)) { | |
5909 | bpf_log(log, | |
5910 | "arg%d in %s() is not a pointer to context\n", | |
5911 | i, fn2); | |
5912 | return -EINVAL; | |
5913 | } | |
5914 | /* This is an optional check to make program writing easier. | |
5915 | * Compare names of structs and report an error to the user. | |
5916 | * btf_prepare_func_args() already checked that t2 struct | |
5917 | * is a context type. btf_prepare_func_args() will check | |
5918 | * later that t1 struct is a context type as well. | |
5919 | */ | |
5920 | s1 = btf_name_by_offset(btf1, t1->name_off); | |
5921 | s2 = btf_name_by_offset(btf2, t2->name_off); | |
5922 | if (strcmp(s1, s2)) { | |
5923 | bpf_log(log, | |
5924 | "arg%d %s(struct %s *) doesn't match %s(struct %s *)\n", | |
5925 | i, fn1, s1, fn2, s2); | |
5926 | return -EINVAL; | |
5927 | } | |
5928 | } | |
5929 | return 0; | |
5930 | } | |
5931 | ||
5932 | /* Compare BTFs of given program with BTF of target program */ | |
efc68158 | 5933 | int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog, |
be8704ff AS |
5934 | struct btf *btf2, const struct btf_type *t2) |
5935 | { | |
5936 | struct btf *btf1 = prog->aux->btf; | |
5937 | const struct btf_type *t1; | |
5938 | u32 btf_id = 0; | |
5939 | ||
5940 | if (!prog->aux->func_info) { | |
efc68158 | 5941 | bpf_log(log, "Program extension requires BTF\n"); |
be8704ff AS |
5942 | return -EINVAL; |
5943 | } | |
5944 | ||
5945 | btf_id = prog->aux->func_info[0].type_id; | |
5946 | if (!btf_id) | |
5947 | return -EFAULT; | |
5948 | ||
5949 | t1 = btf_type_by_id(btf1, btf_id); | |
5950 | if (!t1 || !btf_type_is_func(t1)) | |
5951 | return -EFAULT; | |
5952 | ||
efc68158 | 5953 | return btf_check_func_type_match(log, btf1, t1, btf2, t2); |
be8704ff AS |
5954 | } |
5955 | ||
e6ac2450 MKL |
5956 | static u32 *reg2btf_ids[__BPF_REG_TYPE_MAX] = { |
5957 | #ifdef CONFIG_NET | |
5958 | [PTR_TO_SOCKET] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK], | |
5959 | [PTR_TO_SOCK_COMMON] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON], | |
5960 | [PTR_TO_TCP_SOCK] = &btf_sock_ids[BTF_SOCK_TYPE_TCP], | |
5961 | #endif | |
5962 | }; | |
5963 | ||
3363bd0c KKD |
5964 | /* Returns true if struct is composed of scalars, 4 levels of nesting allowed */ |
5965 | static bool __btf_type_is_scalar_struct(struct bpf_verifier_log *log, | |
5966 | const struct btf *btf, | |
5967 | const struct btf_type *t, int rec) | |
5968 | { | |
5969 | const struct btf_type *member_type; | |
5970 | const struct btf_member *member; | |
5971 | u32 i; | |
5972 | ||
5973 | if (!btf_type_is_struct(t)) | |
5974 | return false; | |
5975 | ||
5976 | for_each_member(i, t, member) { | |
5977 | const struct btf_array *array; | |
5978 | ||
5979 | member_type = btf_type_skip_modifiers(btf, member->type, NULL); | |
5980 | if (btf_type_is_struct(member_type)) { | |
5981 | if (rec >= 3) { | |
5982 | bpf_log(log, "max struct nesting depth exceeded\n"); | |
5983 | return false; | |
5984 | } | |
5985 | if (!__btf_type_is_scalar_struct(log, btf, member_type, rec + 1)) | |
5986 | return false; | |
5987 | continue; | |
5988 | } | |
5989 | if (btf_type_is_array(member_type)) { | |
5990 | array = btf_type_array(member_type); | |
5991 | if (!array->nelems) | |
5992 | return false; | |
5993 | member_type = btf_type_skip_modifiers(btf, array->type, NULL); | |
5994 | if (!btf_type_is_scalar(member_type)) | |
5995 | return false; | |
5996 | continue; | |
5997 | } | |
5998 | if (!btf_type_is_scalar(member_type)) | |
5999 | return false; | |
6000 | } | |
6001 | return true; | |
6002 | } | |
6003 | ||
d583691c KKD |
6004 | static bool is_kfunc_arg_mem_size(const struct btf *btf, |
6005 | const struct btf_param *arg, | |
6006 | const struct bpf_reg_state *reg) | |
6007 | { | |
6008 | int len, sfx_len = sizeof("__sz") - 1; | |
6009 | const struct btf_type *t; | |
6010 | const char *param_name; | |
6011 | ||
6012 | t = btf_type_skip_modifiers(btf, arg->type, NULL); | |
6013 | if (!btf_type_is_scalar(t) || reg->type != SCALAR_VALUE) | |
6014 | return false; | |
6015 | ||
6016 | /* In the future, this can be ported to use BTF tagging */ | |
6017 | param_name = btf_name_by_offset(btf, arg->name_off); | |
6018 | if (str_is_empty(param_name)) | |
6019 | return false; | |
6020 | len = strlen(param_name); | |
6021 | if (len < sfx_len) | |
6022 | return false; | |
6023 | param_name += len - sfx_len; | |
6024 | if (strncmp(param_name, "__sz", sfx_len)) | |
6025 | return false; | |
6026 | ||
6027 | return true; | |
6028 | } | |
6029 | ||
34747c41 MKL |
6030 | static int btf_check_func_arg_match(struct bpf_verifier_env *env, |
6031 | const struct btf *btf, u32 func_id, | |
6032 | struct bpf_reg_state *regs, | |
6033 | bool ptr_to_mem_ok) | |
8c1b6e69 | 6034 | { |
8c1b6e69 | 6035 | struct bpf_verifier_log *log = &env->log; |
5c073f26 | 6036 | u32 i, nargs, ref_id, ref_obj_id = 0; |
3363bd0c | 6037 | bool is_kfunc = btf_is_kernel(btf); |
34747c41 | 6038 | const char *func_name, *ref_tname; |
e5069b9c | 6039 | const struct btf_type *t, *ref_t; |
34747c41 | 6040 | const struct btf_param *args; |
655efe50 | 6041 | int ref_regno = 0, ret; |
5c073f26 | 6042 | bool rel = false; |
8c1b6e69 | 6043 | |
34747c41 | 6044 | t = btf_type_by_id(btf, func_id); |
8c1b6e69 | 6045 | if (!t || !btf_type_is_func(t)) { |
51c39bb1 | 6046 | /* These checks were already done by the verifier while loading |
e6ac2450 | 6047 | * struct bpf_func_info or in add_kfunc_call(). |
51c39bb1 | 6048 | */ |
34747c41 MKL |
6049 | bpf_log(log, "BTF of func_id %u doesn't point to KIND_FUNC\n", |
6050 | func_id); | |
51c39bb1 | 6051 | return -EFAULT; |
8c1b6e69 | 6052 | } |
34747c41 | 6053 | func_name = btf_name_by_offset(btf, t->name_off); |
8c1b6e69 AS |
6054 | |
6055 | t = btf_type_by_id(btf, t->type); | |
6056 | if (!t || !btf_type_is_func_proto(t)) { | |
34747c41 | 6057 | bpf_log(log, "Invalid BTF of func %s\n", func_name); |
51c39bb1 | 6058 | return -EFAULT; |
8c1b6e69 AS |
6059 | } |
6060 | args = (const struct btf_param *)(t + 1); | |
6061 | nargs = btf_type_vlen(t); | |
523a4cf4 | 6062 | if (nargs > MAX_BPF_FUNC_REG_ARGS) { |
34747c41 | 6063 | bpf_log(log, "Function %s has %d > %d args\n", func_name, nargs, |
523a4cf4 | 6064 | MAX_BPF_FUNC_REG_ARGS); |
34747c41 | 6065 | return -EINVAL; |
8c1b6e69 | 6066 | } |
e5069b9c | 6067 | |
24d5bb80 KKD |
6068 | /* Only kfunc can be release func */ |
6069 | if (is_kfunc) | |
6070 | rel = btf_kfunc_id_set_contains(btf, resolve_prog_type(env->prog), | |
6071 | BTF_KFUNC_TYPE_RELEASE, func_id); | |
8c1b6e69 AS |
6072 | /* check that BTF function arguments match actual types that the |
6073 | * verifier sees. | |
6074 | */ | |
6075 | for (i = 0; i < nargs; i++) { | |
8f14852e | 6076 | enum bpf_arg_type arg_type = ARG_DONTCARE; |
34747c41 MKL |
6077 | u32 regno = i + 1; |
6078 | struct bpf_reg_state *reg = ®s[regno]; | |
feb4adfa | 6079 | |
34747c41 MKL |
6080 | t = btf_type_skip_modifiers(btf, args[i].type, NULL); |
6081 | if (btf_type_is_scalar(t)) { | |
feb4adfa | 6082 | if (reg->type == SCALAR_VALUE) |
8c1b6e69 | 6083 | continue; |
34747c41 MKL |
6084 | bpf_log(log, "R%d is not a scalar\n", regno); |
6085 | return -EINVAL; | |
8c1b6e69 | 6086 | } |
34747c41 MKL |
6087 | |
6088 | if (!btf_type_is_ptr(t)) { | |
6089 | bpf_log(log, "Unrecognized arg#%d type %s\n", | |
6090 | i, btf_type_str(t)); | |
6091 | return -EINVAL; | |
6092 | } | |
6093 | ||
e6ac2450 | 6094 | ref_t = btf_type_skip_modifiers(btf, t->type, &ref_id); |
34747c41 | 6095 | ref_tname = btf_name_by_offset(btf, ref_t->name_off); |
655efe50 | 6096 | |
8f14852e KKD |
6097 | if (rel && reg->ref_obj_id) |
6098 | arg_type |= OBJ_RELEASE; | |
6099 | ret = check_func_arg_reg_off(env, reg, regno, arg_type); | |
655efe50 KKD |
6100 | if (ret < 0) |
6101 | return ret; | |
6102 | ||
3363bd0c KKD |
6103 | if (btf_get_prog_ctx_type(log, btf, t, |
6104 | env->prog->type, i)) { | |
6105 | /* If function expects ctx type in BTF check that caller | |
6106 | * is passing PTR_TO_CTX. | |
6107 | */ | |
6108 | if (reg->type != PTR_TO_CTX) { | |
6109 | bpf_log(log, | |
6110 | "arg#%d expected pointer to ctx, but got %s\n", | |
6111 | i, btf_type_str(t)); | |
6112 | return -EINVAL; | |
6113 | } | |
45ce4b4f KKD |
6114 | } else if (is_kfunc && (reg->type == PTR_TO_BTF_ID || |
6115 | (reg2btf_ids[base_type(reg->type)] && !type_flag(reg->type)))) { | |
e6ac2450 MKL |
6116 | const struct btf_type *reg_ref_t; |
6117 | const struct btf *reg_btf; | |
6118 | const char *reg_ref_tname; | |
6119 | u32 reg_ref_id; | |
6120 | ||
6121 | if (!btf_type_is_struct(ref_t)) { | |
6122 | bpf_log(log, "kernel function %s args#%d pointer type %s %s is not supported\n", | |
6123 | func_name, i, btf_type_str(ref_t), | |
6124 | ref_tname); | |
6125 | return -EINVAL; | |
6126 | } | |
6127 | ||
6128 | if (reg->type == PTR_TO_BTF_ID) { | |
6129 | reg_btf = reg->btf; | |
6130 | reg_ref_id = reg->btf_id; | |
8f14852e | 6131 | /* Ensure only one argument is referenced PTR_TO_BTF_ID */ |
5c073f26 KKD |
6132 | if (reg->ref_obj_id) { |
6133 | if (ref_obj_id) { | |
6134 | bpf_log(log, "verifier internal error: more than one arg with ref_obj_id R%d %u %u\n", | |
6135 | regno, reg->ref_obj_id, ref_obj_id); | |
6136 | return -EFAULT; | |
6137 | } | |
6138 | ref_regno = regno; | |
6139 | ref_obj_id = reg->ref_obj_id; | |
6140 | } | |
3363bd0c | 6141 | } else { |
e6ac2450 | 6142 | reg_btf = btf_vmlinux; |
45ce4b4f | 6143 | reg_ref_id = *reg2btf_ids[base_type(reg->type)]; |
e6ac2450 MKL |
6144 | } |
6145 | ||
6146 | reg_ref_t = btf_type_skip_modifiers(reg_btf, reg_ref_id, | |
6147 | ®_ref_id); | |
6148 | reg_ref_tname = btf_name_by_offset(reg_btf, | |
6149 | reg_ref_t->name_off); | |
6150 | if (!btf_struct_ids_match(log, reg_btf, reg_ref_id, | |
6151 | reg->off, btf, ref_id)) { | |
6152 | bpf_log(log, "kernel function %s args#%d expected pointer to %s %s but R%d has a pointer to %s %s\n", | |
6153 | func_name, i, | |
6154 | btf_type_str(ref_t), ref_tname, | |
6155 | regno, btf_type_str(reg_ref_t), | |
6156 | reg_ref_tname); | |
6157 | return -EINVAL; | |
6158 | } | |
34747c41 MKL |
6159 | } else if (ptr_to_mem_ok) { |
6160 | const struct btf_type *resolve_ret; | |
6161 | u32 type_size; | |
e5069b9c | 6162 | |
3363bd0c | 6163 | if (is_kfunc) { |
d583691c KKD |
6164 | bool arg_mem_size = i + 1 < nargs && is_kfunc_arg_mem_size(btf, &args[i + 1], ®s[regno + 1]); |
6165 | ||
3363bd0c KKD |
6166 | /* Permit pointer to mem, but only when argument |
6167 | * type is pointer to scalar, or struct composed | |
6168 | * (recursively) of scalars. | |
d583691c KKD |
6169 | * When arg_mem_size is true, the pointer can be |
6170 | * void *. | |
3363bd0c KKD |
6171 | */ |
6172 | if (!btf_type_is_scalar(ref_t) && | |
d583691c KKD |
6173 | !__btf_type_is_scalar_struct(log, btf, ref_t, 0) && |
6174 | (arg_mem_size ? !btf_type_is_void(ref_t) : 1)) { | |
3363bd0c | 6175 | bpf_log(log, |
d583691c KKD |
6176 | "arg#%d pointer type %s %s must point to %sscalar, or struct with scalar\n", |
6177 | i, btf_type_str(ref_t), ref_tname, arg_mem_size ? "void, " : ""); | |
3363bd0c KKD |
6178 | return -EINVAL; |
6179 | } | |
d583691c KKD |
6180 | |
6181 | /* Check for mem, len pair */ | |
6182 | if (arg_mem_size) { | |
6183 | if (check_kfunc_mem_size_reg(env, ®s[regno + 1], regno + 1)) { | |
6184 | bpf_log(log, "arg#%d arg#%d memory, len pair leads to invalid memory access\n", | |
6185 | i, i + 1); | |
6186 | return -EINVAL; | |
6187 | } | |
6188 | i++; | |
6189 | continue; | |
6190 | } | |
3363bd0c KKD |
6191 | } |
6192 | ||
34747c41 MKL |
6193 | resolve_ret = btf_resolve_size(btf, ref_t, &type_size); |
6194 | if (IS_ERR(resolve_ret)) { | |
e5069b9c | 6195 | bpf_log(log, |
34747c41 MKL |
6196 | "arg#%d reference type('%s %s') size cannot be determined: %ld\n", |
6197 | i, btf_type_str(ref_t), ref_tname, | |
6198 | PTR_ERR(resolve_ret)); | |
6199 | return -EINVAL; | |
e5069b9c DB |
6200 | } |
6201 | ||
34747c41 MKL |
6202 | if (check_mem_reg(env, reg, regno, type_size)) |
6203 | return -EINVAL; | |
6204 | } else { | |
3363bd0c KKD |
6205 | bpf_log(log, "reg type unsupported for arg#%d %sfunction %s#%d\n", i, |
6206 | is_kfunc ? "kernel " : "", func_name, func_id); | |
34747c41 | 6207 | return -EINVAL; |
8c1b6e69 | 6208 | } |
8c1b6e69 | 6209 | } |
34747c41 | 6210 | |
5c073f26 KKD |
6211 | /* Either both are set, or neither */ |
6212 | WARN_ON_ONCE((ref_obj_id && !ref_regno) || (!ref_obj_id && ref_regno)); | |
24d5bb80 KKD |
6213 | /* We already made sure ref_obj_id is set only for one argument. We do |
6214 | * allow (!rel && ref_obj_id), so that passing such referenced | |
6215 | * PTR_TO_BTF_ID to other kfuncs works. Note that rel is only true when | |
6216 | * is_kfunc is true. | |
6217 | */ | |
6218 | if (rel && !ref_obj_id) { | |
6219 | bpf_log(log, "release kernel function %s expects refcounted PTR_TO_BTF_ID\n", | |
6220 | func_name); | |
6221 | return -EINVAL; | |
5c073f26 KKD |
6222 | } |
6223 | /* returns argument register number > 0 in case of reference release kfunc */ | |
6224 | return rel ? ref_regno : 0; | |
34747c41 MKL |
6225 | } |
6226 | ||
6227 | /* Compare BTF of a function with given bpf_reg_state. | |
6228 | * Returns: | |
6229 | * EFAULT - there is a verifier bug. Abort verification. | |
6230 | * EINVAL - there is a type mismatch or BTF is not available. | |
6231 | * 0 - BTF matches with what bpf_reg_state expects. | |
6232 | * Only PTR_TO_CTX and SCALAR_VALUE states are recognized. | |
6233 | */ | |
6234 | int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog, | |
6235 | struct bpf_reg_state *regs) | |
6236 | { | |
6237 | struct bpf_prog *prog = env->prog; | |
6238 | struct btf *btf = prog->aux->btf; | |
6239 | bool is_global; | |
6240 | u32 btf_id; | |
6241 | int err; | |
6242 | ||
6243 | if (!prog->aux->func_info) | |
6244 | return -EINVAL; | |
6245 | ||
6246 | btf_id = prog->aux->func_info[subprog].type_id; | |
6247 | if (!btf_id) | |
6248 | return -EFAULT; | |
6249 | ||
6250 | if (prog->aux->func_info_aux[subprog].unreliable) | |
6251 | return -EINVAL; | |
6252 | ||
6253 | is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL; | |
6254 | err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global); | |
6255 | ||
51c39bb1 AS |
6256 | /* Compiler optimizations can remove arguments from static functions |
6257 | * or mismatched type can be passed into a global function. | |
6258 | * In such cases mark the function as unreliable from BTF point of view. | |
6259 | */ | |
34747c41 MKL |
6260 | if (err) |
6261 | prog->aux->func_info_aux[subprog].unreliable = true; | |
6262 | return err; | |
51c39bb1 AS |
6263 | } |
6264 | ||
e6ac2450 MKL |
6265 | int btf_check_kfunc_arg_match(struct bpf_verifier_env *env, |
6266 | const struct btf *btf, u32 func_id, | |
6267 | struct bpf_reg_state *regs) | |
6268 | { | |
3363bd0c | 6269 | return btf_check_func_arg_match(env, btf, func_id, regs, true); |
e6ac2450 MKL |
6270 | } |
6271 | ||
51c39bb1 AS |
6272 | /* Convert BTF of a function into bpf_reg_state if possible |
6273 | * Returns: | |
6274 | * EFAULT - there is a verifier bug. Abort verification. | |
6275 | * EINVAL - cannot convert BTF. | |
6276 | * 0 - Successfully converted BTF into bpf_reg_state | |
6277 | * (either PTR_TO_CTX or SCALAR_VALUE). | |
6278 | */ | |
6279 | int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog, | |
feb4adfa | 6280 | struct bpf_reg_state *regs) |
51c39bb1 AS |
6281 | { |
6282 | struct bpf_verifier_log *log = &env->log; | |
6283 | struct bpf_prog *prog = env->prog; | |
be8704ff | 6284 | enum bpf_prog_type prog_type = prog->type; |
51c39bb1 AS |
6285 | struct btf *btf = prog->aux->btf; |
6286 | const struct btf_param *args; | |
e5069b9c | 6287 | const struct btf_type *t, *ref_t; |
51c39bb1 AS |
6288 | u32 i, nargs, btf_id; |
6289 | const char *tname; | |
6290 | ||
6291 | if (!prog->aux->func_info || | |
6292 | prog->aux->func_info_aux[subprog].linkage != BTF_FUNC_GLOBAL) { | |
6293 | bpf_log(log, "Verifier bug\n"); | |
6294 | return -EFAULT; | |
6295 | } | |
6296 | ||
6297 | btf_id = prog->aux->func_info[subprog].type_id; | |
6298 | if (!btf_id) { | |
6299 | bpf_log(log, "Global functions need valid BTF\n"); | |
6300 | return -EFAULT; | |
6301 | } | |
6302 | ||
6303 | t = btf_type_by_id(btf, btf_id); | |
6304 | if (!t || !btf_type_is_func(t)) { | |
6305 | /* These checks were already done by the verifier while loading | |
6306 | * struct bpf_func_info | |
6307 | */ | |
6308 | bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n", | |
6309 | subprog); | |
6310 | return -EFAULT; | |
6311 | } | |
6312 | tname = btf_name_by_offset(btf, t->name_off); | |
6313 | ||
6314 | if (log->level & BPF_LOG_LEVEL) | |
6315 | bpf_log(log, "Validating %s() func#%d...\n", | |
6316 | tname, subprog); | |
6317 | ||
6318 | if (prog->aux->func_info_aux[subprog].unreliable) { | |
6319 | bpf_log(log, "Verifier bug in function %s()\n", tname); | |
6320 | return -EFAULT; | |
6321 | } | |
be8704ff | 6322 | if (prog_type == BPF_PROG_TYPE_EXT) |
3aac1ead | 6323 | prog_type = prog->aux->dst_prog->type; |
51c39bb1 AS |
6324 | |
6325 | t = btf_type_by_id(btf, t->type); | |
6326 | if (!t || !btf_type_is_func_proto(t)) { | |
6327 | bpf_log(log, "Invalid type of function %s()\n", tname); | |
6328 | return -EFAULT; | |
6329 | } | |
6330 | args = (const struct btf_param *)(t + 1); | |
6331 | nargs = btf_type_vlen(t); | |
523a4cf4 DB |
6332 | if (nargs > MAX_BPF_FUNC_REG_ARGS) { |
6333 | bpf_log(log, "Global function %s() with %d > %d args. Buggy compiler.\n", | |
6334 | tname, nargs, MAX_BPF_FUNC_REG_ARGS); | |
51c39bb1 AS |
6335 | return -EINVAL; |
6336 | } | |
6337 | /* check that function returns int */ | |
6338 | t = btf_type_by_id(btf, t->type); | |
6339 | while (btf_type_is_modifier(t)) | |
6340 | t = btf_type_by_id(btf, t->type); | |
6341 | if (!btf_type_is_int(t) && !btf_type_is_enum(t)) { | |
6342 | bpf_log(log, | |
6343 | "Global function %s() doesn't return scalar. Only those are supported.\n", | |
6344 | tname); | |
6345 | return -EINVAL; | |
6346 | } | |
6347 | /* Convert BTF function arguments into verifier types. | |
6348 | * Only PTR_TO_CTX and SCALAR are supported atm. | |
6349 | */ | |
6350 | for (i = 0; i < nargs; i++) { | |
feb4adfa DB |
6351 | struct bpf_reg_state *reg = ®s[i + 1]; |
6352 | ||
51c39bb1 AS |
6353 | t = btf_type_by_id(btf, args[i].type); |
6354 | while (btf_type_is_modifier(t)) | |
6355 | t = btf_type_by_id(btf, t->type); | |
6356 | if (btf_type_is_int(t) || btf_type_is_enum(t)) { | |
feb4adfa | 6357 | reg->type = SCALAR_VALUE; |
51c39bb1 AS |
6358 | continue; |
6359 | } | |
e5069b9c DB |
6360 | if (btf_type_is_ptr(t)) { |
6361 | if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) { | |
6362 | reg->type = PTR_TO_CTX; | |
6363 | continue; | |
6364 | } | |
6365 | ||
6366 | t = btf_type_skip_modifiers(btf, t->type, NULL); | |
6367 | ||
6368 | ref_t = btf_resolve_size(btf, t, ®->mem_size); | |
6369 | if (IS_ERR(ref_t)) { | |
6370 | bpf_log(log, | |
6371 | "arg#%d reference type('%s %s') size cannot be determined: %ld\n", | |
6372 | i, btf_type_str(t), btf_name_by_offset(btf, t->name_off), | |
6373 | PTR_ERR(ref_t)); | |
6374 | return -EINVAL; | |
6375 | } | |
6376 | ||
cf9f2f8d | 6377 | reg->type = PTR_TO_MEM | PTR_MAYBE_NULL; |
e5069b9c DB |
6378 | reg->id = ++env->id_gen; |
6379 | ||
51c39bb1 AS |
6380 | continue; |
6381 | } | |
6382 | bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n", | |
6383 | i, btf_kind_str[BTF_INFO_KIND(t->info)], tname); | |
6384 | return -EINVAL; | |
6385 | } | |
8c1b6e69 AS |
6386 | return 0; |
6387 | } | |
6388 | ||
31d0bc81 AM |
6389 | static void btf_type_show(const struct btf *btf, u32 type_id, void *obj, |
6390 | struct btf_show *show) | |
6391 | { | |
6392 | const struct btf_type *t = btf_type_by_id(btf, type_id); | |
6393 | ||
6394 | show->btf = btf; | |
6395 | memset(&show->state, 0, sizeof(show->state)); | |
6396 | memset(&show->obj, 0, sizeof(show->obj)); | |
6397 | ||
6398 | btf_type_ops(t)->show(btf, t, type_id, obj, 0, show); | |
6399 | } | |
6400 | ||
6401 | static void btf_seq_show(struct btf_show *show, const char *fmt, | |
6402 | va_list args) | |
6403 | { | |
6404 | seq_vprintf((struct seq_file *)show->target, fmt, args); | |
6405 | } | |
6406 | ||
eb411377 AM |
6407 | int btf_type_seq_show_flags(const struct btf *btf, u32 type_id, |
6408 | void *obj, struct seq_file *m, u64 flags) | |
31d0bc81 AM |
6409 | { |
6410 | struct btf_show sseq; | |
6411 | ||
6412 | sseq.target = m; | |
6413 | sseq.showfn = btf_seq_show; | |
6414 | sseq.flags = flags; | |
6415 | ||
6416 | btf_type_show(btf, type_id, obj, &sseq); | |
6417 | ||
6418 | return sseq.state.status; | |
6419 | } | |
6420 | ||
b00b8dae MKL |
6421 | void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj, |
6422 | struct seq_file *m) | |
6423 | { | |
31d0bc81 AM |
6424 | (void) btf_type_seq_show_flags(btf, type_id, obj, m, |
6425 | BTF_SHOW_NONAME | BTF_SHOW_COMPACT | | |
6426 | BTF_SHOW_ZERO | BTF_SHOW_UNSAFE); | |
6427 | } | |
6428 | ||
6429 | struct btf_show_snprintf { | |
6430 | struct btf_show show; | |
6431 | int len_left; /* space left in string */ | |
6432 | int len; /* length we would have written */ | |
6433 | }; | |
6434 | ||
6435 | static void btf_snprintf_show(struct btf_show *show, const char *fmt, | |
6436 | va_list args) | |
6437 | { | |
6438 | struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show; | |
6439 | int len; | |
6440 | ||
6441 | len = vsnprintf(show->target, ssnprintf->len_left, fmt, args); | |
6442 | ||
6443 | if (len < 0) { | |
6444 | ssnprintf->len_left = 0; | |
6445 | ssnprintf->len = len; | |
6446 | } else if (len > ssnprintf->len_left) { | |
6447 | /* no space, drive on to get length we would have written */ | |
6448 | ssnprintf->len_left = 0; | |
6449 | ssnprintf->len += len; | |
6450 | } else { | |
6451 | ssnprintf->len_left -= len; | |
6452 | ssnprintf->len += len; | |
6453 | show->target += len; | |
6454 | } | |
6455 | } | |
6456 | ||
6457 | int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj, | |
6458 | char *buf, int len, u64 flags) | |
6459 | { | |
6460 | struct btf_show_snprintf ssnprintf; | |
6461 | ||
6462 | ssnprintf.show.target = buf; | |
6463 | ssnprintf.show.flags = flags; | |
6464 | ssnprintf.show.showfn = btf_snprintf_show; | |
6465 | ssnprintf.len_left = len; | |
6466 | ssnprintf.len = 0; | |
6467 | ||
6468 | btf_type_show(btf, type_id, obj, (struct btf_show *)&ssnprintf); | |
6469 | ||
c561d110 | 6470 | /* If we encountered an error, return it. */ |
31d0bc81 AM |
6471 | if (ssnprintf.show.state.status) |
6472 | return ssnprintf.show.state.status; | |
b00b8dae | 6473 | |
31d0bc81 AM |
6474 | /* Otherwise return length we would have written */ |
6475 | return ssnprintf.len; | |
b00b8dae | 6476 | } |
f56a653c | 6477 | |
3481e64b QM |
6478 | #ifdef CONFIG_PROC_FS |
6479 | static void bpf_btf_show_fdinfo(struct seq_file *m, struct file *filp) | |
6480 | { | |
6481 | const struct btf *btf = filp->private_data; | |
6482 | ||
6483 | seq_printf(m, "btf_id:\t%u\n", btf->id); | |
6484 | } | |
6485 | #endif | |
6486 | ||
f56a653c MKL |
6487 | static int btf_release(struct inode *inode, struct file *filp) |
6488 | { | |
6489 | btf_put(filp->private_data); | |
6490 | return 0; | |
6491 | } | |
6492 | ||
60197cfb | 6493 | const struct file_operations btf_fops = { |
3481e64b QM |
6494 | #ifdef CONFIG_PROC_FS |
6495 | .show_fdinfo = bpf_btf_show_fdinfo, | |
6496 | #endif | |
f56a653c MKL |
6497 | .release = btf_release, |
6498 | }; | |
6499 | ||
78958fca MKL |
6500 | static int __btf_new_fd(struct btf *btf) |
6501 | { | |
6502 | return anon_inode_getfd("btf", &btf_fops, btf, O_RDONLY | O_CLOEXEC); | |
6503 | } | |
6504 | ||
c571bd75 | 6505 | int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr) |
f56a653c MKL |
6506 | { |
6507 | struct btf *btf; | |
78958fca | 6508 | int ret; |
f56a653c | 6509 | |
c571bd75 | 6510 | btf = btf_parse(make_bpfptr(attr->btf, uattr.is_kernel), |
f56a653c MKL |
6511 | attr->btf_size, attr->btf_log_level, |
6512 | u64_to_user_ptr(attr->btf_log_buf), | |
6513 | attr->btf_log_size); | |
6514 | if (IS_ERR(btf)) | |
6515 | return PTR_ERR(btf); | |
6516 | ||
78958fca MKL |
6517 | ret = btf_alloc_id(btf); |
6518 | if (ret) { | |
6519 | btf_free(btf); | |
6520 | return ret; | |
6521 | } | |
6522 | ||
6523 | /* | |
6524 | * The BTF ID is published to the userspace. | |
6525 | * All BTF free must go through call_rcu() from | |
6526 | * now on (i.e. free by calling btf_put()). | |
6527 | */ | |
6528 | ||
6529 | ret = __btf_new_fd(btf); | |
6530 | if (ret < 0) | |
f56a653c MKL |
6531 | btf_put(btf); |
6532 | ||
78958fca | 6533 | return ret; |
f56a653c MKL |
6534 | } |
6535 | ||
6536 | struct btf *btf_get_by_fd(int fd) | |
6537 | { | |
6538 | struct btf *btf; | |
6539 | struct fd f; | |
6540 | ||
6541 | f = fdget(fd); | |
6542 | ||
6543 | if (!f.file) | |
6544 | return ERR_PTR(-EBADF); | |
6545 | ||
6546 | if (f.file->f_op != &btf_fops) { | |
6547 | fdput(f); | |
6548 | return ERR_PTR(-EINVAL); | |
6549 | } | |
6550 | ||
6551 | btf = f.file->private_data; | |
78958fca | 6552 | refcount_inc(&btf->refcnt); |
f56a653c MKL |
6553 | fdput(f); |
6554 | ||
6555 | return btf; | |
6556 | } | |
60197cfb MKL |
6557 | |
6558 | int btf_get_info_by_fd(const struct btf *btf, | |
6559 | const union bpf_attr *attr, | |
6560 | union bpf_attr __user *uattr) | |
6561 | { | |
62dab84c | 6562 | struct bpf_btf_info __user *uinfo; |
5c6f2588 | 6563 | struct bpf_btf_info info; |
62dab84c MKL |
6564 | u32 info_copy, btf_copy; |
6565 | void __user *ubtf; | |
53297220 AN |
6566 | char __user *uname; |
6567 | u32 uinfo_len, uname_len, name_len; | |
6568 | int ret = 0; | |
60197cfb | 6569 | |
62dab84c MKL |
6570 | uinfo = u64_to_user_ptr(attr->info.info); |
6571 | uinfo_len = attr->info.info_len; | |
6572 | ||
6573 | info_copy = min_t(u32, uinfo_len, sizeof(info)); | |
5c6f2588 | 6574 | memset(&info, 0, sizeof(info)); |
62dab84c MKL |
6575 | if (copy_from_user(&info, uinfo, info_copy)) |
6576 | return -EFAULT; | |
6577 | ||
6578 | info.id = btf->id; | |
6579 | ubtf = u64_to_user_ptr(info.btf); | |
6580 | btf_copy = min_t(u32, btf->data_size, info.btf_size); | |
6581 | if (copy_to_user(ubtf, btf->data, btf_copy)) | |
6582 | return -EFAULT; | |
6583 | info.btf_size = btf->data_size; | |
6584 | ||
53297220 AN |
6585 | info.kernel_btf = btf->kernel_btf; |
6586 | ||
6587 | uname = u64_to_user_ptr(info.name); | |
6588 | uname_len = info.name_len; | |
6589 | if (!uname ^ !uname_len) | |
6590 | return -EINVAL; | |
6591 | ||
6592 | name_len = strlen(btf->name); | |
6593 | info.name_len = name_len; | |
6594 | ||
6595 | if (uname) { | |
6596 | if (uname_len >= name_len + 1) { | |
6597 | if (copy_to_user(uname, btf->name, name_len + 1)) | |
6598 | return -EFAULT; | |
6599 | } else { | |
6600 | char zero = '\0'; | |
6601 | ||
6602 | if (copy_to_user(uname, btf->name, uname_len - 1)) | |
6603 | return -EFAULT; | |
6604 | if (put_user(zero, uname + uname_len - 1)) | |
6605 | return -EFAULT; | |
6606 | /* let user-space know about too short buffer */ | |
6607 | ret = -ENOSPC; | |
6608 | } | |
6609 | } | |
6610 | ||
62dab84c MKL |
6611 | if (copy_to_user(uinfo, &info, info_copy) || |
6612 | put_user(info_copy, &uattr->info.info_len)) | |
60197cfb MKL |
6613 | return -EFAULT; |
6614 | ||
53297220 | 6615 | return ret; |
60197cfb | 6616 | } |
78958fca MKL |
6617 | |
6618 | int btf_get_fd_by_id(u32 id) | |
6619 | { | |
6620 | struct btf *btf; | |
6621 | int fd; | |
6622 | ||
6623 | rcu_read_lock(); | |
6624 | btf = idr_find(&btf_idr, id); | |
6625 | if (!btf || !refcount_inc_not_zero(&btf->refcnt)) | |
6626 | btf = ERR_PTR(-ENOENT); | |
6627 | rcu_read_unlock(); | |
6628 | ||
6629 | if (IS_ERR(btf)) | |
6630 | return PTR_ERR(btf); | |
6631 | ||
6632 | fd = __btf_new_fd(btf); | |
6633 | if (fd < 0) | |
6634 | btf_put(btf); | |
6635 | ||
6636 | return fd; | |
6637 | } | |
6638 | ||
22dc4a0f | 6639 | u32 btf_obj_id(const struct btf *btf) |
78958fca MKL |
6640 | { |
6641 | return btf->id; | |
6642 | } | |
eae2e83e | 6643 | |
290248a5 AN |
6644 | bool btf_is_kernel(const struct btf *btf) |
6645 | { | |
6646 | return btf->kernel_btf; | |
6647 | } | |
6648 | ||
541c3bad AN |
6649 | bool btf_is_module(const struct btf *btf) |
6650 | { | |
6651 | return btf->kernel_btf && strcmp(btf->name, "vmlinux") != 0; | |
6652 | } | |
6653 | ||
eae2e83e JO |
6654 | static int btf_id_cmp_func(const void *a, const void *b) |
6655 | { | |
6656 | const int *pa = a, *pb = b; | |
6657 | ||
6658 | return *pa - *pb; | |
6659 | } | |
6660 | ||
2af30f11 | 6661 | bool btf_id_set_contains(const struct btf_id_set *set, u32 id) |
eae2e83e JO |
6662 | { |
6663 | return bsearch(&id, set->ids, set->cnt, sizeof(u32), btf_id_cmp_func) != NULL; | |
6664 | } | |
36e68442 | 6665 | |
18688de2 KKD |
6666 | enum { |
6667 | BTF_MODULE_F_LIVE = (1 << 0), | |
6668 | }; | |
6669 | ||
36e68442 AN |
6670 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
6671 | struct btf_module { | |
6672 | struct list_head list; | |
6673 | struct module *module; | |
6674 | struct btf *btf; | |
6675 | struct bin_attribute *sysfs_attr; | |
18688de2 | 6676 | int flags; |
36e68442 AN |
6677 | }; |
6678 | ||
6679 | static LIST_HEAD(btf_modules); | |
6680 | static DEFINE_MUTEX(btf_module_mutex); | |
6681 | ||
6682 | static ssize_t | |
6683 | btf_module_read(struct file *file, struct kobject *kobj, | |
6684 | struct bin_attribute *bin_attr, | |
6685 | char *buf, loff_t off, size_t len) | |
6686 | { | |
6687 | const struct btf *btf = bin_attr->private; | |
6688 | ||
6689 | memcpy(buf, btf->data + off, len); | |
6690 | return len; | |
6691 | } | |
6692 | ||
1e89106d AS |
6693 | static void purge_cand_cache(struct btf *btf); |
6694 | ||
36e68442 AN |
6695 | static int btf_module_notify(struct notifier_block *nb, unsigned long op, |
6696 | void *module) | |
6697 | { | |
6698 | struct btf_module *btf_mod, *tmp; | |
6699 | struct module *mod = module; | |
6700 | struct btf *btf; | |
6701 | int err = 0; | |
6702 | ||
6703 | if (mod->btf_data_size == 0 || | |
18688de2 KKD |
6704 | (op != MODULE_STATE_COMING && op != MODULE_STATE_LIVE && |
6705 | op != MODULE_STATE_GOING)) | |
36e68442 AN |
6706 | goto out; |
6707 | ||
6708 | switch (op) { | |
6709 | case MODULE_STATE_COMING: | |
6710 | btf_mod = kzalloc(sizeof(*btf_mod), GFP_KERNEL); | |
6711 | if (!btf_mod) { | |
6712 | err = -ENOMEM; | |
6713 | goto out; | |
6714 | } | |
6715 | btf = btf_parse_module(mod->name, mod->btf_data, mod->btf_data_size); | |
6716 | if (IS_ERR(btf)) { | |
6717 | pr_warn("failed to validate module [%s] BTF: %ld\n", | |
6718 | mod->name, PTR_ERR(btf)); | |
6719 | kfree(btf_mod); | |
5e214f2e CB |
6720 | if (!IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) |
6721 | err = PTR_ERR(btf); | |
36e68442 AN |
6722 | goto out; |
6723 | } | |
6724 | err = btf_alloc_id(btf); | |
6725 | if (err) { | |
6726 | btf_free(btf); | |
6727 | kfree(btf_mod); | |
6728 | goto out; | |
6729 | } | |
6730 | ||
1e89106d | 6731 | purge_cand_cache(NULL); |
36e68442 AN |
6732 | mutex_lock(&btf_module_mutex); |
6733 | btf_mod->module = module; | |
6734 | btf_mod->btf = btf; | |
6735 | list_add(&btf_mod->list, &btf_modules); | |
6736 | mutex_unlock(&btf_module_mutex); | |
6737 | ||
6738 | if (IS_ENABLED(CONFIG_SYSFS)) { | |
6739 | struct bin_attribute *attr; | |
6740 | ||
6741 | attr = kzalloc(sizeof(*attr), GFP_KERNEL); | |
6742 | if (!attr) | |
6743 | goto out; | |
6744 | ||
6745 | sysfs_bin_attr_init(attr); | |
6746 | attr->attr.name = btf->name; | |
6747 | attr->attr.mode = 0444; | |
6748 | attr->size = btf->data_size; | |
6749 | attr->private = btf; | |
6750 | attr->read = btf_module_read; | |
6751 | ||
6752 | err = sysfs_create_bin_file(btf_kobj, attr); | |
6753 | if (err) { | |
6754 | pr_warn("failed to register module [%s] BTF in sysfs: %d\n", | |
6755 | mod->name, err); | |
6756 | kfree(attr); | |
6757 | err = 0; | |
6758 | goto out; | |
6759 | } | |
6760 | ||
6761 | btf_mod->sysfs_attr = attr; | |
6762 | } | |
6763 | ||
18688de2 KKD |
6764 | break; |
6765 | case MODULE_STATE_LIVE: | |
6766 | mutex_lock(&btf_module_mutex); | |
6767 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
6768 | if (btf_mod->module != module) | |
6769 | continue; | |
6770 | ||
6771 | btf_mod->flags |= BTF_MODULE_F_LIVE; | |
6772 | break; | |
6773 | } | |
6774 | mutex_unlock(&btf_module_mutex); | |
36e68442 AN |
6775 | break; |
6776 | case MODULE_STATE_GOING: | |
6777 | mutex_lock(&btf_module_mutex); | |
6778 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
6779 | if (btf_mod->module != module) | |
6780 | continue; | |
6781 | ||
6782 | list_del(&btf_mod->list); | |
6783 | if (btf_mod->sysfs_attr) | |
6784 | sysfs_remove_bin_file(btf_kobj, btf_mod->sysfs_attr); | |
1e89106d | 6785 | purge_cand_cache(btf_mod->btf); |
36e68442 AN |
6786 | btf_put(btf_mod->btf); |
6787 | kfree(btf_mod->sysfs_attr); | |
6788 | kfree(btf_mod); | |
6789 | break; | |
6790 | } | |
6791 | mutex_unlock(&btf_module_mutex); | |
6792 | break; | |
6793 | } | |
6794 | out: | |
6795 | return notifier_from_errno(err); | |
6796 | } | |
6797 | ||
6798 | static struct notifier_block btf_module_nb = { | |
6799 | .notifier_call = btf_module_notify, | |
6800 | }; | |
6801 | ||
6802 | static int __init btf_module_init(void) | |
6803 | { | |
6804 | register_module_notifier(&btf_module_nb); | |
6805 | return 0; | |
6806 | } | |
6807 | ||
6808 | fs_initcall(btf_module_init); | |
6809 | #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */ | |
541c3bad AN |
6810 | |
6811 | struct module *btf_try_get_module(const struct btf *btf) | |
6812 | { | |
6813 | struct module *res = NULL; | |
6814 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES | |
6815 | struct btf_module *btf_mod, *tmp; | |
6816 | ||
6817 | mutex_lock(&btf_module_mutex); | |
6818 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
6819 | if (btf_mod->btf != btf) | |
6820 | continue; | |
6821 | ||
18688de2 KKD |
6822 | /* We must only consider module whose __init routine has |
6823 | * finished, hence we must check for BTF_MODULE_F_LIVE flag, | |
6824 | * which is set from the notifier callback for | |
6825 | * MODULE_STATE_LIVE. | |
6826 | */ | |
6827 | if ((btf_mod->flags & BTF_MODULE_F_LIVE) && try_module_get(btf_mod->module)) | |
541c3bad AN |
6828 | res = btf_mod->module; |
6829 | ||
6830 | break; | |
6831 | } | |
6832 | mutex_unlock(&btf_module_mutex); | |
6833 | #endif | |
6834 | ||
6835 | return res; | |
6836 | } | |
3d78417b | 6837 | |
9492450f KKD |
6838 | /* Returns struct btf corresponding to the struct module. |
6839 | * This function can return NULL or ERR_PTR. | |
dee872e1 KKD |
6840 | */ |
6841 | static struct btf *btf_get_module_btf(const struct module *module) | |
6842 | { | |
dee872e1 KKD |
6843 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
6844 | struct btf_module *btf_mod, *tmp; | |
6845 | #endif | |
9492450f KKD |
6846 | struct btf *btf = NULL; |
6847 | ||
6848 | if (!module) { | |
6849 | btf = bpf_get_btf_vmlinux(); | |
7ada3787 | 6850 | if (!IS_ERR_OR_NULL(btf)) |
9492450f KKD |
6851 | btf_get(btf); |
6852 | return btf; | |
6853 | } | |
dee872e1 | 6854 | |
dee872e1 KKD |
6855 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
6856 | mutex_lock(&btf_module_mutex); | |
6857 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
6858 | if (btf_mod->module != module) | |
6859 | continue; | |
6860 | ||
6861 | btf_get(btf_mod->btf); | |
6862 | btf = btf_mod->btf; | |
6863 | break; | |
6864 | } | |
6865 | mutex_unlock(&btf_module_mutex); | |
6866 | #endif | |
6867 | ||
6868 | return btf; | |
6869 | } | |
6870 | ||
3d78417b AS |
6871 | BPF_CALL_4(bpf_btf_find_by_name_kind, char *, name, int, name_sz, u32, kind, int, flags) |
6872 | { | |
edc3ec09 KKD |
6873 | struct btf *btf = NULL; |
6874 | int btf_obj_fd = 0; | |
3d78417b AS |
6875 | long ret; |
6876 | ||
6877 | if (flags) | |
6878 | return -EINVAL; | |
6879 | ||
6880 | if (name_sz <= 1 || name[name_sz - 1]) | |
6881 | return -EINVAL; | |
6882 | ||
edc3ec09 KKD |
6883 | ret = bpf_find_btf_id(name, kind, &btf); |
6884 | if (ret > 0 && btf_is_module(btf)) { | |
6885 | btf_obj_fd = __btf_new_fd(btf); | |
6886 | if (btf_obj_fd < 0) { | |
6887 | btf_put(btf); | |
6888 | return btf_obj_fd; | |
3d78417b | 6889 | } |
edc3ec09 | 6890 | return ret | (((u64)btf_obj_fd) << 32); |
3d78417b | 6891 | } |
edc3ec09 KKD |
6892 | if (ret > 0) |
6893 | btf_put(btf); | |
3d78417b AS |
6894 | return ret; |
6895 | } | |
6896 | ||
6897 | const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = { | |
6898 | .func = bpf_btf_find_by_name_kind, | |
6899 | .gpl_only = false, | |
6900 | .ret_type = RET_INTEGER, | |
216e3cd2 | 6901 | .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
3d78417b AS |
6902 | .arg2_type = ARG_CONST_SIZE, |
6903 | .arg3_type = ARG_ANYTHING, | |
6904 | .arg4_type = ARG_ANYTHING, | |
6905 | }; | |
eb529c5b | 6906 | |
d19ddb47 SL |
6907 | BTF_ID_LIST_GLOBAL(btf_tracing_ids, MAX_BTF_TRACING_TYPE) |
6908 | #define BTF_TRACING_TYPE(name, type) BTF_ID(struct, type) | |
6909 | BTF_TRACING_TYPE_xxx | |
6910 | #undef BTF_TRACING_TYPE | |
14f267d9 | 6911 | |
dee872e1 | 6912 | /* Kernel Function (kfunc) BTF ID set registration API */ |
14f267d9 | 6913 | |
dee872e1 KKD |
6914 | static int __btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, |
6915 | enum btf_kfunc_type type, | |
6916 | struct btf_id_set *add_set, bool vmlinux_set) | |
14f267d9 | 6917 | { |
dee872e1 KKD |
6918 | struct btf_kfunc_set_tab *tab; |
6919 | struct btf_id_set *set; | |
6920 | u32 set_cnt; | |
6921 | int ret; | |
6922 | ||
6923 | if (hook >= BTF_KFUNC_HOOK_MAX || type >= BTF_KFUNC_TYPE_MAX) { | |
6924 | ret = -EINVAL; | |
6925 | goto end; | |
6926 | } | |
6927 | ||
6928 | if (!add_set->cnt) | |
6929 | return 0; | |
6930 | ||
6931 | tab = btf->kfunc_set_tab; | |
6932 | if (!tab) { | |
6933 | tab = kzalloc(sizeof(*tab), GFP_KERNEL | __GFP_NOWARN); | |
6934 | if (!tab) | |
6935 | return -ENOMEM; | |
6936 | btf->kfunc_set_tab = tab; | |
6937 | } | |
6938 | ||
6939 | set = tab->sets[hook][type]; | |
6940 | /* Warn when register_btf_kfunc_id_set is called twice for the same hook | |
6941 | * for module sets. | |
6942 | */ | |
6943 | if (WARN_ON_ONCE(set && !vmlinux_set)) { | |
6944 | ret = -EINVAL; | |
6945 | goto end; | |
6946 | } | |
6947 | ||
6948 | /* We don't need to allocate, concatenate, and sort module sets, because | |
6949 | * only one is allowed per hook. Hence, we can directly assign the | |
6950 | * pointer and return. | |
6951 | */ | |
6952 | if (!vmlinux_set) { | |
6953 | tab->sets[hook][type] = add_set; | |
6954 | return 0; | |
6955 | } | |
6956 | ||
6957 | /* In case of vmlinux sets, there may be more than one set being | |
6958 | * registered per hook. To create a unified set, we allocate a new set | |
6959 | * and concatenate all individual sets being registered. While each set | |
6960 | * is individually sorted, they may become unsorted when concatenated, | |
6961 | * hence re-sorting the final set again is required to make binary | |
6962 | * searching the set using btf_id_set_contains function work. | |
6963 | */ | |
6964 | set_cnt = set ? set->cnt : 0; | |
6965 | ||
6966 | if (set_cnt > U32_MAX - add_set->cnt) { | |
6967 | ret = -EOVERFLOW; | |
6968 | goto end; | |
6969 | } | |
6970 | ||
6971 | if (set_cnt + add_set->cnt > BTF_KFUNC_SET_MAX_CNT) { | |
6972 | ret = -E2BIG; | |
6973 | goto end; | |
6974 | } | |
6975 | ||
6976 | /* Grow set */ | |
6977 | set = krealloc(tab->sets[hook][type], | |
6978 | offsetof(struct btf_id_set, ids[set_cnt + add_set->cnt]), | |
6979 | GFP_KERNEL | __GFP_NOWARN); | |
6980 | if (!set) { | |
6981 | ret = -ENOMEM; | |
6982 | goto end; | |
6983 | } | |
6984 | ||
6985 | /* For newly allocated set, initialize set->cnt to 0 */ | |
6986 | if (!tab->sets[hook][type]) | |
6987 | set->cnt = 0; | |
6988 | tab->sets[hook][type] = set; | |
6989 | ||
6990 | /* Concatenate the two sets */ | |
6991 | memcpy(set->ids + set->cnt, add_set->ids, add_set->cnt * sizeof(set->ids[0])); | |
6992 | set->cnt += add_set->cnt; | |
6993 | ||
6994 | sort(set->ids, set->cnt, sizeof(set->ids[0]), btf_id_cmp_func, NULL); | |
6995 | ||
6996 | return 0; | |
6997 | end: | |
6998 | btf_free_kfunc_set_tab(btf); | |
6999 | return ret; | |
14f267d9 | 7000 | } |
14f267d9 | 7001 | |
dee872e1 KKD |
7002 | static int btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, |
7003 | const struct btf_kfunc_id_set *kset) | |
14f267d9 | 7004 | { |
dee872e1 | 7005 | bool vmlinux_set = !btf_is_module(btf); |
d0b38229 | 7006 | int type, ret = 0; |
dee872e1 KKD |
7007 | |
7008 | for (type = 0; type < ARRAY_SIZE(kset->sets); type++) { | |
7009 | if (!kset->sets[type]) | |
7010 | continue; | |
7011 | ||
7012 | ret = __btf_populate_kfunc_set(btf, hook, type, kset->sets[type], vmlinux_set); | |
7013 | if (ret) | |
7014 | break; | |
7015 | } | |
7016 | return ret; | |
14f267d9 | 7017 | } |
14f267d9 | 7018 | |
dee872e1 KKD |
7019 | static bool __btf_kfunc_id_set_contains(const struct btf *btf, |
7020 | enum btf_kfunc_hook hook, | |
7021 | enum btf_kfunc_type type, | |
7022 | u32 kfunc_btf_id) | |
14f267d9 | 7023 | { |
dee872e1 | 7024 | struct btf_id_set *set; |
14f267d9 | 7025 | |
dee872e1 KKD |
7026 | if (hook >= BTF_KFUNC_HOOK_MAX || type >= BTF_KFUNC_TYPE_MAX) |
7027 | return false; | |
7028 | if (!btf->kfunc_set_tab) | |
7029 | return false; | |
7030 | set = btf->kfunc_set_tab->sets[hook][type]; | |
7031 | if (!set) | |
7032 | return false; | |
7033 | return btf_id_set_contains(set, kfunc_btf_id); | |
7034 | } | |
7035 | ||
7036 | static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type) | |
7037 | { | |
7038 | switch (prog_type) { | |
7039 | case BPF_PROG_TYPE_XDP: | |
7040 | return BTF_KFUNC_HOOK_XDP; | |
7041 | case BPF_PROG_TYPE_SCHED_CLS: | |
7042 | return BTF_KFUNC_HOOK_TC; | |
7043 | case BPF_PROG_TYPE_STRUCT_OPS: | |
7044 | return BTF_KFUNC_HOOK_STRUCT_OPS; | |
7045 | default: | |
7046 | return BTF_KFUNC_HOOK_MAX; | |
14f267d9 | 7047 | } |
14f267d9 KKD |
7048 | } |
7049 | ||
dee872e1 KKD |
7050 | /* Caution: |
7051 | * Reference to the module (obtained using btf_try_get_module) corresponding to | |
7052 | * the struct btf *MUST* be held when calling this function from verifier | |
7053 | * context. This is usually true as we stash references in prog's kfunc_btf_tab; | |
7054 | * keeping the reference for the duration of the call provides the necessary | |
7055 | * protection for looking up a well-formed btf->kfunc_set_tab. | |
7056 | */ | |
7057 | bool btf_kfunc_id_set_contains(const struct btf *btf, | |
7058 | enum bpf_prog_type prog_type, | |
7059 | enum btf_kfunc_type type, u32 kfunc_btf_id) | |
7060 | { | |
7061 | enum btf_kfunc_hook hook; | |
0e32dfc8 | 7062 | |
dee872e1 KKD |
7063 | hook = bpf_prog_type_to_kfunc_hook(prog_type); |
7064 | return __btf_kfunc_id_set_contains(btf, hook, type, kfunc_btf_id); | |
7065 | } | |
d9847eb8 | 7066 | |
dee872e1 KKD |
7067 | /* This function must be invoked only from initcalls/module init functions */ |
7068 | int register_btf_kfunc_id_set(enum bpf_prog_type prog_type, | |
7069 | const struct btf_kfunc_id_set *kset) | |
7070 | { | |
7071 | enum btf_kfunc_hook hook; | |
7072 | struct btf *btf; | |
7073 | int ret; | |
7074 | ||
7075 | btf = btf_get_module_btf(kset->owner); | |
c446fdac SF |
7076 | if (!btf) { |
7077 | if (!kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) { | |
7078 | pr_err("missing vmlinux BTF, cannot register kfuncs\n"); | |
7079 | return -ENOENT; | |
7080 | } | |
7081 | if (kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) { | |
7082 | pr_err("missing module BTF, cannot register kfuncs\n"); | |
7083 | return -ENOENT; | |
7084 | } | |
7085 | return 0; | |
7086 | } | |
7087 | if (IS_ERR(btf)) | |
7088 | return PTR_ERR(btf); | |
dee872e1 KKD |
7089 | |
7090 | hook = bpf_prog_type_to_kfunc_hook(prog_type); | |
7091 | ret = btf_populate_kfunc_set(btf, hook, kset); | |
9492450f | 7092 | btf_put(btf); |
dee872e1 KKD |
7093 | return ret; |
7094 | } | |
7095 | EXPORT_SYMBOL_GPL(register_btf_kfunc_id_set); | |
be315829 | 7096 | |
5ce937d6 KKD |
7097 | s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id) |
7098 | { | |
7099 | struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab; | |
7100 | struct btf_id_dtor_kfunc *dtor; | |
7101 | ||
7102 | if (!tab) | |
7103 | return -ENOENT; | |
7104 | /* Even though the size of tab->dtors[0] is > sizeof(u32), we only need | |
7105 | * to compare the first u32 with btf_id, so we can reuse btf_id_cmp_func. | |
7106 | */ | |
7107 | BUILD_BUG_ON(offsetof(struct btf_id_dtor_kfunc, btf_id) != 0); | |
7108 | dtor = bsearch(&btf_id, tab->dtors, tab->cnt, sizeof(tab->dtors[0]), btf_id_cmp_func); | |
7109 | if (!dtor) | |
7110 | return -ENOENT; | |
7111 | return dtor->kfunc_btf_id; | |
7112 | } | |
7113 | ||
7114 | /* This function must be invoked only from initcalls/module init functions */ | |
7115 | int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_cnt, | |
7116 | struct module *owner) | |
7117 | { | |
7118 | struct btf_id_dtor_kfunc_tab *tab; | |
7119 | struct btf *btf; | |
7120 | u32 tab_cnt; | |
7121 | int ret; | |
7122 | ||
7123 | btf = btf_get_module_btf(owner); | |
7124 | if (!btf) { | |
7125 | if (!owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) { | |
7126 | pr_err("missing vmlinux BTF, cannot register dtor kfuncs\n"); | |
7127 | return -ENOENT; | |
7128 | } | |
7129 | if (owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) { | |
7130 | pr_err("missing module BTF, cannot register dtor kfuncs\n"); | |
7131 | return -ENOENT; | |
7132 | } | |
7133 | return 0; | |
7134 | } | |
7135 | if (IS_ERR(btf)) | |
7136 | return PTR_ERR(btf); | |
7137 | ||
7138 | if (add_cnt >= BTF_DTOR_KFUNC_MAX_CNT) { | |
7139 | pr_err("cannot register more than %d kfunc destructors\n", BTF_DTOR_KFUNC_MAX_CNT); | |
7140 | ret = -E2BIG; | |
7141 | goto end; | |
7142 | } | |
7143 | ||
7144 | tab = btf->dtor_kfunc_tab; | |
7145 | /* Only one call allowed for modules */ | |
7146 | if (WARN_ON_ONCE(tab && btf_is_module(btf))) { | |
7147 | ret = -EINVAL; | |
7148 | goto end; | |
7149 | } | |
7150 | ||
7151 | tab_cnt = tab ? tab->cnt : 0; | |
7152 | if (tab_cnt > U32_MAX - add_cnt) { | |
7153 | ret = -EOVERFLOW; | |
7154 | goto end; | |
7155 | } | |
7156 | if (tab_cnt + add_cnt >= BTF_DTOR_KFUNC_MAX_CNT) { | |
7157 | pr_err("cannot register more than %d kfunc destructors\n", BTF_DTOR_KFUNC_MAX_CNT); | |
7158 | ret = -E2BIG; | |
7159 | goto end; | |
7160 | } | |
7161 | ||
7162 | tab = krealloc(btf->dtor_kfunc_tab, | |
7163 | offsetof(struct btf_id_dtor_kfunc_tab, dtors[tab_cnt + add_cnt]), | |
7164 | GFP_KERNEL | __GFP_NOWARN); | |
7165 | if (!tab) { | |
7166 | ret = -ENOMEM; | |
7167 | goto end; | |
7168 | } | |
7169 | ||
7170 | if (!btf->dtor_kfunc_tab) | |
7171 | tab->cnt = 0; | |
7172 | btf->dtor_kfunc_tab = tab; | |
7173 | ||
7174 | memcpy(tab->dtors + tab->cnt, dtors, add_cnt * sizeof(tab->dtors[0])); | |
7175 | tab->cnt += add_cnt; | |
7176 | ||
7177 | sort(tab->dtors, tab->cnt, sizeof(tab->dtors[0]), btf_id_cmp_func, NULL); | |
7178 | ||
7179 | return 0; | |
7180 | end: | |
7181 | btf_free_dtor_kfunc_tab(btf); | |
7182 | btf_put(btf); | |
7183 | return ret; | |
7184 | } | |
7185 | EXPORT_SYMBOL_GPL(register_btf_id_dtor_kfuncs); | |
7186 | ||
e70e13e7 MC |
7187 | #define MAX_TYPES_ARE_COMPAT_DEPTH 2 |
7188 | ||
7189 | static | |
7190 | int __bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, | |
7191 | const struct btf *targ_btf, __u32 targ_id, | |
7192 | int level) | |
7193 | { | |
7194 | const struct btf_type *local_type, *targ_type; | |
7195 | int depth = 32; /* max recursion depth */ | |
7196 | ||
7197 | /* caller made sure that names match (ignoring flavor suffix) */ | |
7198 | local_type = btf_type_by_id(local_btf, local_id); | |
7199 | targ_type = btf_type_by_id(targ_btf, targ_id); | |
7200 | if (btf_kind(local_type) != btf_kind(targ_type)) | |
7201 | return 0; | |
7202 | ||
7203 | recur: | |
7204 | depth--; | |
7205 | if (depth < 0) | |
7206 | return -EINVAL; | |
7207 | ||
7208 | local_type = btf_type_skip_modifiers(local_btf, local_id, &local_id); | |
7209 | targ_type = btf_type_skip_modifiers(targ_btf, targ_id, &targ_id); | |
7210 | if (!local_type || !targ_type) | |
7211 | return -EINVAL; | |
7212 | ||
7213 | if (btf_kind(local_type) != btf_kind(targ_type)) | |
7214 | return 0; | |
7215 | ||
7216 | switch (btf_kind(local_type)) { | |
7217 | case BTF_KIND_UNKN: | |
7218 | case BTF_KIND_STRUCT: | |
7219 | case BTF_KIND_UNION: | |
7220 | case BTF_KIND_ENUM: | |
7221 | case BTF_KIND_FWD: | |
7222 | return 1; | |
7223 | case BTF_KIND_INT: | |
7224 | /* just reject deprecated bitfield-like integers; all other | |
7225 | * integers are by default compatible between each other | |
7226 | */ | |
7227 | return btf_int_offset(local_type) == 0 && btf_int_offset(targ_type) == 0; | |
7228 | case BTF_KIND_PTR: | |
7229 | local_id = local_type->type; | |
7230 | targ_id = targ_type->type; | |
7231 | goto recur; | |
7232 | case BTF_KIND_ARRAY: | |
7233 | local_id = btf_array(local_type)->type; | |
7234 | targ_id = btf_array(targ_type)->type; | |
7235 | goto recur; | |
7236 | case BTF_KIND_FUNC_PROTO: { | |
7237 | struct btf_param *local_p = btf_params(local_type); | |
7238 | struct btf_param *targ_p = btf_params(targ_type); | |
7239 | __u16 local_vlen = btf_vlen(local_type); | |
7240 | __u16 targ_vlen = btf_vlen(targ_type); | |
7241 | int i, err; | |
7242 | ||
7243 | if (local_vlen != targ_vlen) | |
7244 | return 0; | |
7245 | ||
7246 | for (i = 0; i < local_vlen; i++, local_p++, targ_p++) { | |
7247 | if (level <= 0) | |
7248 | return -EINVAL; | |
7249 | ||
7250 | btf_type_skip_modifiers(local_btf, local_p->type, &local_id); | |
7251 | btf_type_skip_modifiers(targ_btf, targ_p->type, &targ_id); | |
7252 | err = __bpf_core_types_are_compat(local_btf, local_id, | |
7253 | targ_btf, targ_id, | |
7254 | level - 1); | |
7255 | if (err <= 0) | |
7256 | return err; | |
7257 | } | |
7258 | ||
7259 | /* tail recurse for return type check */ | |
7260 | btf_type_skip_modifiers(local_btf, local_type->type, &local_id); | |
7261 | btf_type_skip_modifiers(targ_btf, targ_type->type, &targ_id); | |
7262 | goto recur; | |
7263 | } | |
7264 | default: | |
7265 | return 0; | |
7266 | } | |
7267 | } | |
7268 | ||
7269 | /* Check local and target types for compatibility. This check is used for | |
7270 | * type-based CO-RE relocations and follow slightly different rules than | |
7271 | * field-based relocations. This function assumes that root types were already | |
7272 | * checked for name match. Beyond that initial root-level name check, names | |
7273 | * are completely ignored. Compatibility rules are as follows: | |
7274 | * - any two STRUCTs/UNIONs/FWDs/ENUMs/INTs are considered compatible, but | |
7275 | * kind should match for local and target types (i.e., STRUCT is not | |
7276 | * compatible with UNION); | |
7277 | * - for ENUMs, the size is ignored; | |
7278 | * - for INT, size and signedness are ignored; | |
7279 | * - for ARRAY, dimensionality is ignored, element types are checked for | |
7280 | * compatibility recursively; | |
7281 | * - CONST/VOLATILE/RESTRICT modifiers are ignored; | |
7282 | * - TYPEDEFs/PTRs are compatible if types they pointing to are compatible; | |
7283 | * - FUNC_PROTOs are compatible if they have compatible signature: same | |
7284 | * number of input args and compatible return and argument types. | |
7285 | * These rules are not set in stone and probably will be adjusted as we get | |
7286 | * more experience with using BPF CO-RE relocations. | |
7287 | */ | |
29db4bea AS |
7288 | int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, |
7289 | const struct btf *targ_btf, __u32 targ_id) | |
7290 | { | |
e70e13e7 MC |
7291 | return __bpf_core_types_are_compat(local_btf, local_id, |
7292 | targ_btf, targ_id, | |
7293 | MAX_TYPES_ARE_COMPAT_DEPTH); | |
29db4bea AS |
7294 | } |
7295 | ||
7296 | static bool bpf_core_is_flavor_sep(const char *s) | |
7297 | { | |
7298 | /* check X___Y name pattern, where X and Y are not underscores */ | |
7299 | return s[0] != '_' && /* X */ | |
7300 | s[1] == '_' && s[2] == '_' && s[3] == '_' && /* ___ */ | |
7301 | s[4] != '_'; /* Y */ | |
7302 | } | |
7303 | ||
7304 | size_t bpf_core_essential_name_len(const char *name) | |
7305 | { | |
7306 | size_t n = strlen(name); | |
7307 | int i; | |
7308 | ||
7309 | for (i = n - 5; i >= 0; i--) { | |
7310 | if (bpf_core_is_flavor_sep(name + i)) | |
7311 | return i + 1; | |
7312 | } | |
7313 | return n; | |
7314 | } | |
fbd94c7a | 7315 | |
1e89106d AS |
7316 | struct bpf_cand_cache { |
7317 | const char *name; | |
7318 | u32 name_len; | |
7319 | u16 kind; | |
7320 | u16 cnt; | |
7321 | struct { | |
7322 | const struct btf *btf; | |
7323 | u32 id; | |
7324 | } cands[]; | |
7325 | }; | |
7326 | ||
7327 | static void bpf_free_cands(struct bpf_cand_cache *cands) | |
7328 | { | |
7329 | if (!cands->cnt) | |
7330 | /* empty candidate array was allocated on stack */ | |
7331 | return; | |
7332 | kfree(cands); | |
7333 | } | |
7334 | ||
7335 | static void bpf_free_cands_from_cache(struct bpf_cand_cache *cands) | |
7336 | { | |
7337 | kfree(cands->name); | |
7338 | kfree(cands); | |
7339 | } | |
7340 | ||
7341 | #define VMLINUX_CAND_CACHE_SIZE 31 | |
7342 | static struct bpf_cand_cache *vmlinux_cand_cache[VMLINUX_CAND_CACHE_SIZE]; | |
7343 | ||
7344 | #define MODULE_CAND_CACHE_SIZE 31 | |
7345 | static struct bpf_cand_cache *module_cand_cache[MODULE_CAND_CACHE_SIZE]; | |
7346 | ||
7347 | static DEFINE_MUTEX(cand_cache_mutex); | |
7348 | ||
7349 | static void __print_cand_cache(struct bpf_verifier_log *log, | |
7350 | struct bpf_cand_cache **cache, | |
7351 | int cache_size) | |
7352 | { | |
7353 | struct bpf_cand_cache *cc; | |
7354 | int i, j; | |
7355 | ||
7356 | for (i = 0; i < cache_size; i++) { | |
7357 | cc = cache[i]; | |
7358 | if (!cc) | |
7359 | continue; | |
7360 | bpf_log(log, "[%d]%s(", i, cc->name); | |
7361 | for (j = 0; j < cc->cnt; j++) { | |
7362 | bpf_log(log, "%d", cc->cands[j].id); | |
7363 | if (j < cc->cnt - 1) | |
7364 | bpf_log(log, " "); | |
7365 | } | |
7366 | bpf_log(log, "), "); | |
7367 | } | |
7368 | } | |
7369 | ||
7370 | static void print_cand_cache(struct bpf_verifier_log *log) | |
7371 | { | |
7372 | mutex_lock(&cand_cache_mutex); | |
7373 | bpf_log(log, "vmlinux_cand_cache:"); | |
7374 | __print_cand_cache(log, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); | |
7375 | bpf_log(log, "\nmodule_cand_cache:"); | |
7376 | __print_cand_cache(log, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
7377 | bpf_log(log, "\n"); | |
7378 | mutex_unlock(&cand_cache_mutex); | |
7379 | } | |
7380 | ||
7381 | static u32 hash_cands(struct bpf_cand_cache *cands) | |
7382 | { | |
7383 | return jhash(cands->name, cands->name_len, 0); | |
7384 | } | |
7385 | ||
7386 | static struct bpf_cand_cache *check_cand_cache(struct bpf_cand_cache *cands, | |
7387 | struct bpf_cand_cache **cache, | |
7388 | int cache_size) | |
7389 | { | |
7390 | struct bpf_cand_cache *cc = cache[hash_cands(cands) % cache_size]; | |
7391 | ||
7392 | if (cc && cc->name_len == cands->name_len && | |
7393 | !strncmp(cc->name, cands->name, cands->name_len)) | |
7394 | return cc; | |
7395 | return NULL; | |
7396 | } | |
7397 | ||
7398 | static size_t sizeof_cands(int cnt) | |
7399 | { | |
7400 | return offsetof(struct bpf_cand_cache, cands[cnt]); | |
7401 | } | |
7402 | ||
7403 | static struct bpf_cand_cache *populate_cand_cache(struct bpf_cand_cache *cands, | |
7404 | struct bpf_cand_cache **cache, | |
7405 | int cache_size) | |
7406 | { | |
7407 | struct bpf_cand_cache **cc = &cache[hash_cands(cands) % cache_size], *new_cands; | |
7408 | ||
7409 | if (*cc) { | |
7410 | bpf_free_cands_from_cache(*cc); | |
7411 | *cc = NULL; | |
7412 | } | |
4674f210 | 7413 | new_cands = kmemdup(cands, sizeof_cands(cands->cnt), GFP_KERNEL); |
1e89106d AS |
7414 | if (!new_cands) { |
7415 | bpf_free_cands(cands); | |
7416 | return ERR_PTR(-ENOMEM); | |
7417 | } | |
1e89106d AS |
7418 | /* strdup the name, since it will stay in cache. |
7419 | * the cands->name points to strings in prog's BTF and the prog can be unloaded. | |
7420 | */ | |
7421 | new_cands->name = kmemdup_nul(cands->name, cands->name_len, GFP_KERNEL); | |
7422 | bpf_free_cands(cands); | |
7423 | if (!new_cands->name) { | |
7424 | kfree(new_cands); | |
7425 | return ERR_PTR(-ENOMEM); | |
7426 | } | |
7427 | *cc = new_cands; | |
7428 | return new_cands; | |
7429 | } | |
7430 | ||
29f2e5bd | 7431 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
1e89106d AS |
7432 | static void __purge_cand_cache(struct btf *btf, struct bpf_cand_cache **cache, |
7433 | int cache_size) | |
7434 | { | |
7435 | struct bpf_cand_cache *cc; | |
7436 | int i, j; | |
7437 | ||
7438 | for (i = 0; i < cache_size; i++) { | |
7439 | cc = cache[i]; | |
7440 | if (!cc) | |
7441 | continue; | |
7442 | if (!btf) { | |
7443 | /* when new module is loaded purge all of module_cand_cache, | |
7444 | * since new module might have candidates with the name | |
7445 | * that matches cached cands. | |
7446 | */ | |
7447 | bpf_free_cands_from_cache(cc); | |
7448 | cache[i] = NULL; | |
7449 | continue; | |
7450 | } | |
7451 | /* when module is unloaded purge cache entries | |
7452 | * that match module's btf | |
7453 | */ | |
7454 | for (j = 0; j < cc->cnt; j++) | |
7455 | if (cc->cands[j].btf == btf) { | |
7456 | bpf_free_cands_from_cache(cc); | |
7457 | cache[i] = NULL; | |
7458 | break; | |
7459 | } | |
7460 | } | |
7461 | ||
7462 | } | |
7463 | ||
7464 | static void purge_cand_cache(struct btf *btf) | |
7465 | { | |
7466 | mutex_lock(&cand_cache_mutex); | |
7467 | __purge_cand_cache(btf, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
7468 | mutex_unlock(&cand_cache_mutex); | |
7469 | } | |
29f2e5bd | 7470 | #endif |
1e89106d AS |
7471 | |
7472 | static struct bpf_cand_cache * | |
7473 | bpf_core_add_cands(struct bpf_cand_cache *cands, const struct btf *targ_btf, | |
7474 | int targ_start_id) | |
7475 | { | |
7476 | struct bpf_cand_cache *new_cands; | |
7477 | const struct btf_type *t; | |
7478 | const char *targ_name; | |
7479 | size_t targ_essent_len; | |
7480 | int n, i; | |
7481 | ||
7482 | n = btf_nr_types(targ_btf); | |
7483 | for (i = targ_start_id; i < n; i++) { | |
7484 | t = btf_type_by_id(targ_btf, i); | |
7485 | if (btf_kind(t) != cands->kind) | |
7486 | continue; | |
7487 | ||
7488 | targ_name = btf_name_by_offset(targ_btf, t->name_off); | |
7489 | if (!targ_name) | |
7490 | continue; | |
7491 | ||
7492 | /* the resched point is before strncmp to make sure that search | |
7493 | * for non-existing name will have a chance to schedule(). | |
7494 | */ | |
7495 | cond_resched(); | |
7496 | ||
7497 | if (strncmp(cands->name, targ_name, cands->name_len) != 0) | |
7498 | continue; | |
7499 | ||
7500 | targ_essent_len = bpf_core_essential_name_len(targ_name); | |
7501 | if (targ_essent_len != cands->name_len) | |
7502 | continue; | |
7503 | ||
7504 | /* most of the time there is only one candidate for a given kind+name pair */ | |
7505 | new_cands = kmalloc(sizeof_cands(cands->cnt + 1), GFP_KERNEL); | |
7506 | if (!new_cands) { | |
7507 | bpf_free_cands(cands); | |
7508 | return ERR_PTR(-ENOMEM); | |
7509 | } | |
7510 | ||
7511 | memcpy(new_cands, cands, sizeof_cands(cands->cnt)); | |
7512 | bpf_free_cands(cands); | |
7513 | cands = new_cands; | |
7514 | cands->cands[cands->cnt].btf = targ_btf; | |
7515 | cands->cands[cands->cnt].id = i; | |
7516 | cands->cnt++; | |
7517 | } | |
7518 | return cands; | |
7519 | } | |
7520 | ||
7521 | static struct bpf_cand_cache * | |
7522 | bpf_core_find_cands(struct bpf_core_ctx *ctx, u32 local_type_id) | |
7523 | { | |
7524 | struct bpf_cand_cache *cands, *cc, local_cand = {}; | |
7525 | const struct btf *local_btf = ctx->btf; | |
7526 | const struct btf_type *local_type; | |
7527 | const struct btf *main_btf; | |
7528 | size_t local_essent_len; | |
7529 | struct btf *mod_btf; | |
7530 | const char *name; | |
7531 | int id; | |
7532 | ||
7533 | main_btf = bpf_get_btf_vmlinux(); | |
7534 | if (IS_ERR(main_btf)) | |
f18a4997 | 7535 | return ERR_CAST(main_btf); |
7ada3787 KKD |
7536 | if (!main_btf) |
7537 | return ERR_PTR(-EINVAL); | |
1e89106d AS |
7538 | |
7539 | local_type = btf_type_by_id(local_btf, local_type_id); | |
7540 | if (!local_type) | |
7541 | return ERR_PTR(-EINVAL); | |
7542 | ||
7543 | name = btf_name_by_offset(local_btf, local_type->name_off); | |
7544 | if (str_is_empty(name)) | |
7545 | return ERR_PTR(-EINVAL); | |
7546 | local_essent_len = bpf_core_essential_name_len(name); | |
7547 | ||
7548 | cands = &local_cand; | |
7549 | cands->name = name; | |
7550 | cands->kind = btf_kind(local_type); | |
7551 | cands->name_len = local_essent_len; | |
7552 | ||
7553 | cc = check_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); | |
7554 | /* cands is a pointer to stack here */ | |
7555 | if (cc) { | |
7556 | if (cc->cnt) | |
7557 | return cc; | |
7558 | goto check_modules; | |
7559 | } | |
7560 | ||
7561 | /* Attempt to find target candidates in vmlinux BTF first */ | |
7562 | cands = bpf_core_add_cands(cands, main_btf, 1); | |
7563 | if (IS_ERR(cands)) | |
f18a4997 | 7564 | return ERR_CAST(cands); |
1e89106d AS |
7565 | |
7566 | /* cands is a pointer to kmalloced memory here if cands->cnt > 0 */ | |
7567 | ||
7568 | /* populate cache even when cands->cnt == 0 */ | |
7569 | cc = populate_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); | |
7570 | if (IS_ERR(cc)) | |
f18a4997 | 7571 | return ERR_CAST(cc); |
1e89106d AS |
7572 | |
7573 | /* if vmlinux BTF has any candidate, don't go for module BTFs */ | |
7574 | if (cc->cnt) | |
7575 | return cc; | |
7576 | ||
7577 | check_modules: | |
7578 | /* cands is a pointer to stack here and cands->cnt == 0 */ | |
7579 | cc = check_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
7580 | if (cc) | |
7581 | /* if cache has it return it even if cc->cnt == 0 */ | |
7582 | return cc; | |
7583 | ||
7584 | /* If candidate is not found in vmlinux's BTF then search in module's BTFs */ | |
7585 | spin_lock_bh(&btf_idr_lock); | |
7586 | idr_for_each_entry(&btf_idr, mod_btf, id) { | |
7587 | if (!btf_is_module(mod_btf)) | |
7588 | continue; | |
7589 | /* linear search could be slow hence unlock/lock | |
7590 | * the IDR to avoiding holding it for too long | |
7591 | */ | |
7592 | btf_get(mod_btf); | |
7593 | spin_unlock_bh(&btf_idr_lock); | |
7594 | cands = bpf_core_add_cands(cands, mod_btf, btf_nr_types(main_btf)); | |
7595 | if (IS_ERR(cands)) { | |
7596 | btf_put(mod_btf); | |
f18a4997 | 7597 | return ERR_CAST(cands); |
1e89106d AS |
7598 | } |
7599 | spin_lock_bh(&btf_idr_lock); | |
7600 | btf_put(mod_btf); | |
7601 | } | |
7602 | spin_unlock_bh(&btf_idr_lock); | |
7603 | /* cands is a pointer to kmalloced memory here if cands->cnt > 0 | |
7604 | * or pointer to stack if cands->cnd == 0. | |
7605 | * Copy it into the cache even when cands->cnt == 0 and | |
7606 | * return the result. | |
7607 | */ | |
7608 | return populate_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
7609 | } | |
7610 | ||
fbd94c7a AS |
7611 | int bpf_core_apply(struct bpf_core_ctx *ctx, const struct bpf_core_relo *relo, |
7612 | int relo_idx, void *insn) | |
7613 | { | |
1e89106d AS |
7614 | bool need_cands = relo->kind != BPF_CORE_TYPE_ID_LOCAL; |
7615 | struct bpf_core_cand_list cands = {}; | |
adb8fa19 | 7616 | struct bpf_core_relo_res targ_res; |
78c1f8d0 | 7617 | struct bpf_core_spec *specs; |
1e89106d AS |
7618 | int err; |
7619 | ||
78c1f8d0 AS |
7620 | /* ~4k of temp memory necessary to convert LLVM spec like "0:1:0:5" |
7621 | * into arrays of btf_ids of struct fields and array indices. | |
7622 | */ | |
7623 | specs = kcalloc(3, sizeof(*specs), GFP_KERNEL); | |
7624 | if (!specs) | |
7625 | return -ENOMEM; | |
7626 | ||
1e89106d AS |
7627 | if (need_cands) { |
7628 | struct bpf_cand_cache *cc; | |
7629 | int i; | |
7630 | ||
7631 | mutex_lock(&cand_cache_mutex); | |
7632 | cc = bpf_core_find_cands(ctx, relo->type_id); | |
7633 | if (IS_ERR(cc)) { | |
7634 | bpf_log(ctx->log, "target candidate search failed for %d\n", | |
7635 | relo->type_id); | |
7636 | err = PTR_ERR(cc); | |
7637 | goto out; | |
7638 | } | |
7639 | if (cc->cnt) { | |
7640 | cands.cands = kcalloc(cc->cnt, sizeof(*cands.cands), GFP_KERNEL); | |
7641 | if (!cands.cands) { | |
7642 | err = -ENOMEM; | |
7643 | goto out; | |
7644 | } | |
7645 | } | |
7646 | for (i = 0; i < cc->cnt; i++) { | |
7647 | bpf_log(ctx->log, | |
7648 | "CO-RE relocating %s %s: found target candidate [%d]\n", | |
7649 | btf_kind_str[cc->kind], cc->name, cc->cands[i].id); | |
7650 | cands.cands[i].btf = cc->cands[i].btf; | |
7651 | cands.cands[i].id = cc->cands[i].id; | |
7652 | } | |
7653 | cands.len = cc->cnt; | |
7654 | /* cand_cache_mutex needs to span the cache lookup and | |
7655 | * copy of btf pointer into bpf_core_cand_list, | |
adb8fa19 | 7656 | * since module can be unloaded while bpf_core_calc_relo_insn |
1e89106d AS |
7657 | * is working with module's btf. |
7658 | */ | |
7659 | } | |
7660 | ||
adb8fa19 MV |
7661 | err = bpf_core_calc_relo_insn((void *)ctx->log, relo, relo_idx, ctx->btf, &cands, specs, |
7662 | &targ_res); | |
7663 | if (err) | |
7664 | goto out; | |
7665 | ||
7666 | err = bpf_core_patch_insn((void *)ctx->log, insn, relo->insn_off / 8, relo, relo_idx, | |
7667 | &targ_res); | |
7668 | ||
1e89106d | 7669 | out: |
78c1f8d0 | 7670 | kfree(specs); |
1e89106d AS |
7671 | if (need_cands) { |
7672 | kfree(cands.cands); | |
7673 | mutex_unlock(&cand_cache_mutex); | |
7674 | if (ctx->log->level & BPF_LOG_LEVEL2) | |
7675 | print_cand_cache(ctx->log); | |
7676 | } | |
7677 | return err; | |
fbd94c7a | 7678 | } |