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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 | 201 | enum btf_kfunc_hook { |
cfe14564 | 202 | BTF_KFUNC_HOOK_COMMON, |
dee872e1 KKD |
203 | BTF_KFUNC_HOOK_XDP, |
204 | BTF_KFUNC_HOOK_TC, | |
205 | BTF_KFUNC_HOOK_STRUCT_OPS, | |
97949767 BT |
206 | BTF_KFUNC_HOOK_TRACING, |
207 | BTF_KFUNC_HOOK_SYSCALL, | |
dee872e1 KKD |
208 | BTF_KFUNC_HOOK_MAX, |
209 | }; | |
210 | ||
211 | enum { | |
f9b34818 | 212 | BTF_KFUNC_SET_MAX_CNT = 256, |
5ce937d6 | 213 | BTF_DTOR_KFUNC_MAX_CNT = 256, |
dee872e1 KKD |
214 | }; |
215 | ||
216 | struct btf_kfunc_set_tab { | |
a4703e31 | 217 | struct btf_id_set8 *sets[BTF_KFUNC_HOOK_MAX]; |
dee872e1 KKD |
218 | }; |
219 | ||
5ce937d6 KKD |
220 | struct btf_id_dtor_kfunc_tab { |
221 | u32 cnt; | |
222 | struct btf_id_dtor_kfunc dtors[]; | |
223 | }; | |
224 | ||
69b693f0 | 225 | struct btf { |
f80442a4 | 226 | void *data; |
69b693f0 | 227 | struct btf_type **types; |
eb3f595d MKL |
228 | u32 *resolved_ids; |
229 | u32 *resolved_sizes; | |
69b693f0 MKL |
230 | const char *strings; |
231 | void *nohdr_data; | |
f80442a4 | 232 | struct btf_header hdr; |
951bb646 | 233 | u32 nr_types; /* includes VOID for base BTF */ |
69b693f0 MKL |
234 | u32 types_size; |
235 | u32 data_size; | |
f56a653c | 236 | refcount_t refcnt; |
78958fca MKL |
237 | u32 id; |
238 | struct rcu_head rcu; | |
dee872e1 | 239 | struct btf_kfunc_set_tab *kfunc_set_tab; |
5ce937d6 | 240 | struct btf_id_dtor_kfunc_tab *dtor_kfunc_tab; |
8ffa5cc1 | 241 | struct btf_struct_metas *struct_meta_tab; |
951bb646 AN |
242 | |
243 | /* split BTF support */ | |
244 | struct btf *base_btf; | |
245 | u32 start_id; /* first type ID in this BTF (0 for base BTF) */ | |
246 | u32 start_str_off; /* first string offset (0 for base BTF) */ | |
53297220 AN |
247 | char name[MODULE_NAME_LEN]; |
248 | bool kernel_btf; | |
69b693f0 MKL |
249 | }; |
250 | ||
eb3f595d MKL |
251 | enum verifier_phase { |
252 | CHECK_META, | |
253 | CHECK_TYPE, | |
254 | }; | |
255 | ||
256 | struct resolve_vertex { | |
257 | const struct btf_type *t; | |
258 | u32 type_id; | |
259 | u16 next_member; | |
260 | }; | |
261 | ||
262 | enum visit_state { | |
263 | NOT_VISITED, | |
264 | VISITED, | |
265 | RESOLVED, | |
266 | }; | |
267 | ||
268 | enum resolve_mode { | |
269 | RESOLVE_TBD, /* To Be Determined */ | |
270 | RESOLVE_PTR, /* Resolving for Pointer */ | |
271 | RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union | |
272 | * or array | |
273 | */ | |
274 | }; | |
275 | ||
276 | #define MAX_RESOLVE_DEPTH 32 | |
277 | ||
f80442a4 MKL |
278 | struct btf_sec_info { |
279 | u32 off; | |
280 | u32 len; | |
281 | }; | |
282 | ||
69b693f0 MKL |
283 | struct btf_verifier_env { |
284 | struct btf *btf; | |
eb3f595d MKL |
285 | u8 *visit_states; |
286 | struct resolve_vertex stack[MAX_RESOLVE_DEPTH]; | |
69b693f0 MKL |
287 | struct bpf_verifier_log log; |
288 | u32 log_type_id; | |
eb3f595d MKL |
289 | u32 top_stack; |
290 | enum verifier_phase phase; | |
291 | enum resolve_mode resolve_mode; | |
69b693f0 MKL |
292 | }; |
293 | ||
294 | static const char * const btf_kind_str[NR_BTF_KINDS] = { | |
295 | [BTF_KIND_UNKN] = "UNKNOWN", | |
296 | [BTF_KIND_INT] = "INT", | |
297 | [BTF_KIND_PTR] = "PTR", | |
298 | [BTF_KIND_ARRAY] = "ARRAY", | |
299 | [BTF_KIND_STRUCT] = "STRUCT", | |
300 | [BTF_KIND_UNION] = "UNION", | |
301 | [BTF_KIND_ENUM] = "ENUM", | |
302 | [BTF_KIND_FWD] = "FWD", | |
303 | [BTF_KIND_TYPEDEF] = "TYPEDEF", | |
304 | [BTF_KIND_VOLATILE] = "VOLATILE", | |
305 | [BTF_KIND_CONST] = "CONST", | |
306 | [BTF_KIND_RESTRICT] = "RESTRICT", | |
2667a262 MKL |
307 | [BTF_KIND_FUNC] = "FUNC", |
308 | [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO", | |
1dc92851 DB |
309 | [BTF_KIND_VAR] = "VAR", |
310 | [BTF_KIND_DATASEC] = "DATASEC", | |
b1828f0b | 311 | [BTF_KIND_FLOAT] = "FLOAT", |
223f903e | 312 | [BTF_KIND_DECL_TAG] = "DECL_TAG", |
8c42d2fa | 313 | [BTF_KIND_TYPE_TAG] = "TYPE_TAG", |
6089fb32 | 314 | [BTF_KIND_ENUM64] = "ENUM64", |
69b693f0 MKL |
315 | }; |
316 | ||
e6ac2450 | 317 | const char *btf_type_str(const struct btf_type *t) |
be8704ff AS |
318 | { |
319 | return btf_kind_str[BTF_INFO_KIND(t->info)]; | |
320 | } | |
321 | ||
31d0bc81 AM |
322 | /* Chunk size we use in safe copy of data to be shown. */ |
323 | #define BTF_SHOW_OBJ_SAFE_SIZE 32 | |
324 | ||
325 | /* | |
326 | * This is the maximum size of a base type value (equivalent to a | |
327 | * 128-bit int); if we are at the end of our safe buffer and have | |
328 | * less than 16 bytes space we can't be assured of being able | |
329 | * to copy the next type safely, so in such cases we will initiate | |
330 | * a new copy. | |
331 | */ | |
332 | #define BTF_SHOW_OBJ_BASE_TYPE_SIZE 16 | |
333 | ||
334 | /* Type name size */ | |
335 | #define BTF_SHOW_NAME_SIZE 80 | |
336 | ||
337 | /* | |
338 | * Common data to all BTF show operations. Private show functions can add | |
339 | * their own data to a structure containing a struct btf_show and consult it | |
340 | * in the show callback. See btf_type_show() below. | |
341 | * | |
342 | * One challenge with showing nested data is we want to skip 0-valued | |
343 | * data, but in order to figure out whether a nested object is all zeros | |
344 | * we need to walk through it. As a result, we need to make two passes | |
345 | * when handling structs, unions and arrays; the first path simply looks | |
346 | * for nonzero data, while the second actually does the display. The first | |
347 | * pass is signalled by show->state.depth_check being set, and if we | |
348 | * encounter a non-zero value we set show->state.depth_to_show to | |
349 | * the depth at which we encountered it. When we have completed the | |
350 | * first pass, we will know if anything needs to be displayed if | |
351 | * depth_to_show > depth. See btf_[struct,array]_show() for the | |
352 | * implementation of this. | |
353 | * | |
354 | * Another problem is we want to ensure the data for display is safe to | |
355 | * access. To support this, the anonymous "struct {} obj" tracks the data | |
356 | * object and our safe copy of it. We copy portions of the data needed | |
357 | * to the object "copy" buffer, but because its size is limited to | |
358 | * BTF_SHOW_OBJ_COPY_LEN bytes, multiple copies may be required as we | |
359 | * traverse larger objects for display. | |
360 | * | |
361 | * The various data type show functions all start with a call to | |
362 | * btf_show_start_type() which returns a pointer to the safe copy | |
363 | * of the data needed (or if BTF_SHOW_UNSAFE is specified, to the | |
364 | * raw data itself). btf_show_obj_safe() is responsible for | |
365 | * using copy_from_kernel_nofault() to update the safe data if necessary | |
366 | * as we traverse the object's data. skbuff-like semantics are | |
367 | * used: | |
368 | * | |
369 | * - obj.head points to the start of the toplevel object for display | |
370 | * - obj.size is the size of the toplevel object | |
371 | * - obj.data points to the current point in the original data at | |
372 | * which our safe data starts. obj.data will advance as we copy | |
373 | * portions of the data. | |
374 | * | |
375 | * In most cases a single copy will suffice, but larger data structures | |
376 | * such as "struct task_struct" will require many copies. The logic in | |
377 | * btf_show_obj_safe() handles the logic that determines if a new | |
378 | * copy_from_kernel_nofault() is needed. | |
379 | */ | |
380 | struct btf_show { | |
381 | u64 flags; | |
382 | void *target; /* target of show operation (seq file, buffer) */ | |
383 | void (*showfn)(struct btf_show *show, const char *fmt, va_list args); | |
384 | const struct btf *btf; | |
385 | /* below are used during iteration */ | |
386 | struct { | |
387 | u8 depth; | |
388 | u8 depth_to_show; | |
389 | u8 depth_check; | |
390 | u8 array_member:1, | |
391 | array_terminated:1; | |
392 | u16 array_encoding; | |
393 | u32 type_id; | |
394 | int status; /* non-zero for error */ | |
395 | const struct btf_type *type; | |
396 | const struct btf_member *member; | |
397 | char name[BTF_SHOW_NAME_SIZE]; /* space for member name/type */ | |
398 | } state; | |
399 | struct { | |
400 | u32 size; | |
401 | void *head; | |
402 | void *data; | |
403 | u8 safe[BTF_SHOW_OBJ_SAFE_SIZE]; | |
404 | } obj; | |
405 | }; | |
406 | ||
69b693f0 MKL |
407 | struct btf_kind_operations { |
408 | s32 (*check_meta)(struct btf_verifier_env *env, | |
409 | const struct btf_type *t, | |
410 | u32 meta_left); | |
eb3f595d MKL |
411 | int (*resolve)(struct btf_verifier_env *env, |
412 | const struct resolve_vertex *v); | |
179cde8c MKL |
413 | int (*check_member)(struct btf_verifier_env *env, |
414 | const struct btf_type *struct_type, | |
415 | const struct btf_member *member, | |
416 | const struct btf_type *member_type); | |
9d5f9f70 YS |
417 | int (*check_kflag_member)(struct btf_verifier_env *env, |
418 | const struct btf_type *struct_type, | |
419 | const struct btf_member *member, | |
420 | const struct btf_type *member_type); | |
69b693f0 MKL |
421 | void (*log_details)(struct btf_verifier_env *env, |
422 | const struct btf_type *t); | |
31d0bc81 | 423 | void (*show)(const struct btf *btf, const struct btf_type *t, |
b00b8dae | 424 | u32 type_id, void *data, u8 bits_offsets, |
31d0bc81 | 425 | struct btf_show *show); |
69b693f0 MKL |
426 | }; |
427 | ||
428 | static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS]; | |
429 | static struct btf_type btf_void; | |
430 | ||
2667a262 MKL |
431 | static int btf_resolve(struct btf_verifier_env *env, |
432 | const struct btf_type *t, u32 type_id); | |
433 | ||
d7e7b42f YS |
434 | static int btf_func_check(struct btf_verifier_env *env, |
435 | const struct btf_type *t); | |
436 | ||
eb3f595d MKL |
437 | static bool btf_type_is_modifier(const struct btf_type *t) |
438 | { | |
439 | /* Some of them is not strictly a C modifier | |
440 | * but they are grouped into the same bucket | |
441 | * for BTF concern: | |
442 | * A type (t) that refers to another | |
443 | * type through t->type AND its size cannot | |
444 | * be determined without following the t->type. | |
445 | * | |
446 | * ptr does not fall into this bucket | |
447 | * because its size is always sizeof(void *). | |
448 | */ | |
449 | switch (BTF_INFO_KIND(t->info)) { | |
450 | case BTF_KIND_TYPEDEF: | |
451 | case BTF_KIND_VOLATILE: | |
452 | case BTF_KIND_CONST: | |
453 | case BTF_KIND_RESTRICT: | |
8c42d2fa | 454 | case BTF_KIND_TYPE_TAG: |
eb3f595d MKL |
455 | return true; |
456 | } | |
457 | ||
458 | return false; | |
459 | } | |
460 | ||
2824ecb7 | 461 | bool btf_type_is_void(const struct btf_type *t) |
eb3f595d | 462 | { |
b47a0bd2 MKL |
463 | return t == &btf_void; |
464 | } | |
465 | ||
466 | static bool btf_type_is_fwd(const struct btf_type *t) | |
467 | { | |
468 | return BTF_INFO_KIND(t->info) == BTF_KIND_FWD; | |
469 | } | |
470 | ||
471 | static bool btf_type_nosize(const struct btf_type *t) | |
472 | { | |
2667a262 MKL |
473 | return btf_type_is_void(t) || btf_type_is_fwd(t) || |
474 | btf_type_is_func(t) || btf_type_is_func_proto(t); | |
eb3f595d MKL |
475 | } |
476 | ||
b47a0bd2 | 477 | static bool btf_type_nosize_or_null(const struct btf_type *t) |
eb3f595d | 478 | { |
b47a0bd2 | 479 | return !t || btf_type_nosize(t); |
eb3f595d MKL |
480 | } |
481 | ||
1dc92851 DB |
482 | static bool btf_type_is_datasec(const struct btf_type *t) |
483 | { | |
484 | return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC; | |
485 | } | |
486 | ||
223f903e | 487 | static bool btf_type_is_decl_tag(const struct btf_type *t) |
b5ea834d | 488 | { |
223f903e | 489 | return BTF_INFO_KIND(t->info) == BTF_KIND_DECL_TAG; |
b5ea834d YS |
490 | } |
491 | ||
223f903e | 492 | static bool btf_type_is_decl_tag_target(const struct btf_type *t) |
b5ea834d YS |
493 | { |
494 | return btf_type_is_func(t) || btf_type_is_struct(t) || | |
bd16dee6 | 495 | btf_type_is_var(t) || btf_type_is_typedef(t); |
b5ea834d YS |
496 | } |
497 | ||
541c3bad | 498 | u32 btf_nr_types(const struct btf *btf) |
951bb646 AN |
499 | { |
500 | u32 total = 0; | |
501 | ||
502 | while (btf) { | |
503 | total += btf->nr_types; | |
504 | btf = btf->base_btf; | |
505 | } | |
506 | ||
507 | return total; | |
508 | } | |
509 | ||
27ae7997 MKL |
510 | s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind) |
511 | { | |
512 | const struct btf_type *t; | |
513 | const char *tname; | |
951bb646 | 514 | u32 i, total; |
27ae7997 | 515 | |
541c3bad | 516 | total = btf_nr_types(btf); |
951bb646 AN |
517 | for (i = 1; i < total; i++) { |
518 | t = btf_type_by_id(btf, i); | |
27ae7997 MKL |
519 | if (BTF_INFO_KIND(t->info) != kind) |
520 | continue; | |
521 | ||
522 | tname = btf_name_by_offset(btf, t->name_off); | |
523 | if (!strcmp(tname, name)) | |
524 | return i; | |
525 | } | |
526 | ||
527 | return -ENOENT; | |
528 | } | |
529 | ||
edc3ec09 KKD |
530 | static s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p) |
531 | { | |
532 | struct btf *btf; | |
533 | s32 ret; | |
534 | int id; | |
535 | ||
536 | btf = bpf_get_btf_vmlinux(); | |
537 | if (IS_ERR(btf)) | |
538 | return PTR_ERR(btf); | |
7ada3787 KKD |
539 | if (!btf) |
540 | return -EINVAL; | |
edc3ec09 KKD |
541 | |
542 | ret = btf_find_by_name_kind(btf, name, kind); | |
543 | /* ret is never zero, since btf_find_by_name_kind returns | |
544 | * positive btf_id or negative error. | |
545 | */ | |
546 | if (ret > 0) { | |
547 | btf_get(btf); | |
548 | *btf_p = btf; | |
549 | return ret; | |
550 | } | |
551 | ||
552 | /* If name is not found in vmlinux's BTF then search in module's BTFs */ | |
553 | spin_lock_bh(&btf_idr_lock); | |
554 | idr_for_each_entry(&btf_idr, btf, id) { | |
555 | if (!btf_is_module(btf)) | |
556 | continue; | |
557 | /* linear search could be slow hence unlock/lock | |
558 | * the IDR to avoiding holding it for too long | |
559 | */ | |
560 | btf_get(btf); | |
561 | spin_unlock_bh(&btf_idr_lock); | |
562 | ret = btf_find_by_name_kind(btf, name, kind); | |
563 | if (ret > 0) { | |
564 | *btf_p = btf; | |
565 | return ret; | |
566 | } | |
567 | spin_lock_bh(&btf_idr_lock); | |
568 | btf_put(btf); | |
569 | } | |
570 | spin_unlock_bh(&btf_idr_lock); | |
571 | return ret; | |
572 | } | |
573 | ||
27ae7997 MKL |
574 | const struct btf_type *btf_type_skip_modifiers(const struct btf *btf, |
575 | u32 id, u32 *res_id) | |
576 | { | |
577 | const struct btf_type *t = btf_type_by_id(btf, id); | |
578 | ||
579 | while (btf_type_is_modifier(t)) { | |
580 | id = t->type; | |
581 | t = btf_type_by_id(btf, t->type); | |
582 | } | |
583 | ||
584 | if (res_id) | |
585 | *res_id = id; | |
586 | ||
587 | return t; | |
588 | } | |
589 | ||
590 | const struct btf_type *btf_type_resolve_ptr(const struct btf *btf, | |
591 | u32 id, u32 *res_id) | |
592 | { | |
593 | const struct btf_type *t; | |
594 | ||
595 | t = btf_type_skip_modifiers(btf, id, NULL); | |
596 | if (!btf_type_is_ptr(t)) | |
597 | return NULL; | |
598 | ||
599 | return btf_type_skip_modifiers(btf, t->type, res_id); | |
600 | } | |
601 | ||
602 | const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf, | |
603 | u32 id, u32 *res_id) | |
604 | { | |
605 | const struct btf_type *ptype; | |
606 | ||
607 | ptype = btf_type_resolve_ptr(btf, id, res_id); | |
608 | if (ptype && btf_type_is_func_proto(ptype)) | |
609 | return ptype; | |
610 | ||
611 | return NULL; | |
612 | } | |
613 | ||
1dc92851 DB |
614 | /* Types that act only as a source, not sink or intermediate |
615 | * type when resolving. | |
616 | */ | |
617 | static bool btf_type_is_resolve_source_only(const struct btf_type *t) | |
618 | { | |
619 | return btf_type_is_var(t) || | |
223f903e | 620 | btf_type_is_decl_tag(t) || |
1dc92851 DB |
621 | btf_type_is_datasec(t); |
622 | } | |
623 | ||
eb3f595d MKL |
624 | /* What types need to be resolved? |
625 | * | |
626 | * btf_type_is_modifier() is an obvious one. | |
627 | * | |
628 | * btf_type_is_struct() because its member refers to | |
629 | * another type (through member->type). | |
1dc92851 DB |
630 | * |
631 | * btf_type_is_var() because the variable refers to | |
632 | * another type. btf_type_is_datasec() holds multiple | |
633 | * btf_type_is_var() types that need resolving. | |
634 | * | |
eb3f595d MKL |
635 | * btf_type_is_array() because its element (array->type) |
636 | * refers to another type. Array can be thought of a | |
637 | * special case of struct while array just has the same | |
638 | * member-type repeated by array->nelems of times. | |
639 | */ | |
640 | static bool btf_type_needs_resolve(const struct btf_type *t) | |
641 | { | |
642 | return btf_type_is_modifier(t) || | |
1dc92851 DB |
643 | btf_type_is_ptr(t) || |
644 | btf_type_is_struct(t) || | |
645 | btf_type_is_array(t) || | |
646 | btf_type_is_var(t) || | |
d7e7b42f | 647 | btf_type_is_func(t) || |
223f903e | 648 | btf_type_is_decl_tag(t) || |
1dc92851 | 649 | btf_type_is_datasec(t); |
eb3f595d MKL |
650 | } |
651 | ||
652 | /* t->size can be used */ | |
653 | static bool btf_type_has_size(const struct btf_type *t) | |
654 | { | |
655 | switch (BTF_INFO_KIND(t->info)) { | |
656 | case BTF_KIND_INT: | |
657 | case BTF_KIND_STRUCT: | |
658 | case BTF_KIND_UNION: | |
659 | case BTF_KIND_ENUM: | |
1dc92851 | 660 | case BTF_KIND_DATASEC: |
b1828f0b | 661 | case BTF_KIND_FLOAT: |
6089fb32 | 662 | case BTF_KIND_ENUM64: |
eb3f595d MKL |
663 | return true; |
664 | } | |
665 | ||
666 | return false; | |
667 | } | |
668 | ||
69b693f0 MKL |
669 | static const char *btf_int_encoding_str(u8 encoding) |
670 | { | |
671 | if (encoding == 0) | |
672 | return "(none)"; | |
673 | else if (encoding == BTF_INT_SIGNED) | |
674 | return "SIGNED"; | |
675 | else if (encoding == BTF_INT_CHAR) | |
676 | return "CHAR"; | |
677 | else if (encoding == BTF_INT_BOOL) | |
678 | return "BOOL"; | |
69b693f0 MKL |
679 | else |
680 | return "UNKN"; | |
681 | } | |
682 | ||
69b693f0 MKL |
683 | static u32 btf_type_int(const struct btf_type *t) |
684 | { | |
685 | return *(u32 *)(t + 1); | |
686 | } | |
687 | ||
688 | static const struct btf_array *btf_type_array(const struct btf_type *t) | |
689 | { | |
690 | return (const struct btf_array *)(t + 1); | |
691 | } | |
692 | ||
69b693f0 MKL |
693 | static const struct btf_enum *btf_type_enum(const struct btf_type *t) |
694 | { | |
695 | return (const struct btf_enum *)(t + 1); | |
696 | } | |
697 | ||
1dc92851 DB |
698 | static const struct btf_var *btf_type_var(const struct btf_type *t) |
699 | { | |
700 | return (const struct btf_var *)(t + 1); | |
701 | } | |
702 | ||
223f903e | 703 | static const struct btf_decl_tag *btf_type_decl_tag(const struct btf_type *t) |
b5ea834d | 704 | { |
223f903e | 705 | return (const struct btf_decl_tag *)(t + 1); |
b5ea834d YS |
706 | } |
707 | ||
6089fb32 YS |
708 | static const struct btf_enum64 *btf_type_enum64(const struct btf_type *t) |
709 | { | |
710 | return (const struct btf_enum64 *)(t + 1); | |
711 | } | |
712 | ||
69b693f0 MKL |
713 | static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t) |
714 | { | |
715 | return kind_ops[BTF_INFO_KIND(t->info)]; | |
716 | } | |
717 | ||
583c5318 | 718 | static bool btf_name_offset_valid(const struct btf *btf, u32 offset) |
69b693f0 | 719 | { |
951bb646 AN |
720 | if (!BTF_STR_OFFSET_VALID(offset)) |
721 | return false; | |
722 | ||
723 | while (offset < btf->start_str_off) | |
724 | btf = btf->base_btf; | |
725 | ||
726 | offset -= btf->start_str_off; | |
727 | return offset < btf->hdr.str_len; | |
69b693f0 MKL |
728 | } |
729 | ||
1dc92851 DB |
730 | static bool __btf_name_char_ok(char c, bool first, bool dot_ok) |
731 | { | |
732 | if ((first ? !isalpha(c) : | |
733 | !isalnum(c)) && | |
734 | c != '_' && | |
735 | ((c == '.' && !dot_ok) || | |
736 | c != '.')) | |
737 | return false; | |
738 | return true; | |
739 | } | |
740 | ||
951bb646 AN |
741 | static const char *btf_str_by_offset(const struct btf *btf, u32 offset) |
742 | { | |
743 | while (offset < btf->start_str_off) | |
744 | btf = btf->base_btf; | |
745 | ||
746 | offset -= btf->start_str_off; | |
747 | if (offset < btf->hdr.str_len) | |
748 | return &btf->strings[offset]; | |
749 | ||
750 | return NULL; | |
751 | } | |
752 | ||
1dc92851 | 753 | static bool __btf_name_valid(const struct btf *btf, u32 offset, bool dot_ok) |
2667a262 MKL |
754 | { |
755 | /* offset must be valid */ | |
951bb646 | 756 | const char *src = btf_str_by_offset(btf, offset); |
2667a262 MKL |
757 | const char *src_limit; |
758 | ||
1dc92851 | 759 | if (!__btf_name_char_ok(*src, true, dot_ok)) |
2667a262 MKL |
760 | return false; |
761 | ||
762 | /* set a limit on identifier length */ | |
763 | src_limit = src + KSYM_NAME_LEN; | |
764 | src++; | |
765 | while (*src && src < src_limit) { | |
1dc92851 | 766 | if (!__btf_name_char_ok(*src, false, dot_ok)) |
2667a262 MKL |
767 | return false; |
768 | src++; | |
769 | } | |
770 | ||
771 | return !*src; | |
772 | } | |
773 | ||
1dc92851 DB |
774 | /* Only C-style identifier is permitted. This can be relaxed if |
775 | * necessary. | |
776 | */ | |
777 | static bool btf_name_valid_identifier(const struct btf *btf, u32 offset) | |
778 | { | |
779 | return __btf_name_valid(btf, offset, false); | |
780 | } | |
781 | ||
782 | static bool btf_name_valid_section(const struct btf *btf, u32 offset) | |
783 | { | |
784 | return __btf_name_valid(btf, offset, true); | |
785 | } | |
786 | ||
23127b33 | 787 | static const char *__btf_name_by_offset(const struct btf *btf, u32 offset) |
69b693f0 | 788 | { |
951bb646 AN |
789 | const char *name; |
790 | ||
aea2f7b8 | 791 | if (!offset) |
69b693f0 | 792 | return "(anon)"; |
951bb646 AN |
793 | |
794 | name = btf_str_by_offset(btf, offset); | |
795 | return name ?: "(invalid-name-offset)"; | |
69b693f0 MKL |
796 | } |
797 | ||
23127b33 MKL |
798 | const char *btf_name_by_offset(const struct btf *btf, u32 offset) |
799 | { | |
951bb646 | 800 | return btf_str_by_offset(btf, offset); |
23127b33 MKL |
801 | } |
802 | ||
838e9690 | 803 | const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id) |
eb3f595d | 804 | { |
951bb646 AN |
805 | while (type_id < btf->start_id) |
806 | btf = btf->base_btf; | |
eb3f595d | 807 | |
951bb646 AN |
808 | type_id -= btf->start_id; |
809 | if (type_id >= btf->nr_types) | |
810 | return NULL; | |
eb3f595d MKL |
811 | return btf->types[type_id]; |
812 | } | |
84c6ac41 | 813 | EXPORT_SYMBOL_GPL(btf_type_by_id); |
eb3f595d | 814 | |
4ef5f574 MKL |
815 | /* |
816 | * Regular int is not a bit field and it must be either | |
b1e8818c | 817 | * u8/u16/u32/u64 or __int128. |
4ef5f574 MKL |
818 | */ |
819 | static bool btf_type_int_is_regular(const struct btf_type *t) | |
820 | { | |
36fc3c8c | 821 | u8 nr_bits, nr_bytes; |
4ef5f574 MKL |
822 | u32 int_data; |
823 | ||
824 | int_data = btf_type_int(t); | |
825 | nr_bits = BTF_INT_BITS(int_data); | |
826 | nr_bytes = BITS_ROUNDUP_BYTES(nr_bits); | |
827 | if (BITS_PER_BYTE_MASKED(nr_bits) || | |
828 | BTF_INT_OFFSET(int_data) || | |
829 | (nr_bytes != sizeof(u8) && nr_bytes != sizeof(u16) && | |
b1e8818c YS |
830 | nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64) && |
831 | nr_bytes != (2 * sizeof(u64)))) { | |
4ef5f574 MKL |
832 | return false; |
833 | } | |
834 | ||
835 | return true; | |
836 | } | |
837 | ||
9a1126b6 | 838 | /* |
ffa0c1cf YS |
839 | * Check that given struct member is a regular int with expected |
840 | * offset and size. | |
9a1126b6 | 841 | */ |
ffa0c1cf YS |
842 | bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s, |
843 | const struct btf_member *m, | |
844 | u32 expected_offset, u32 expected_size) | |
9a1126b6 | 845 | { |
ffa0c1cf YS |
846 | const struct btf_type *t; |
847 | u32 id, int_data; | |
848 | u8 nr_bits; | |
9a1126b6 | 849 | |
ffa0c1cf YS |
850 | id = m->type; |
851 | t = btf_type_id_size(btf, &id, NULL); | |
852 | if (!t || !btf_type_is_int(t)) | |
9a1126b6 RG |
853 | return false; |
854 | ||
855 | int_data = btf_type_int(t); | |
856 | nr_bits = BTF_INT_BITS(int_data); | |
ffa0c1cf YS |
857 | if (btf_type_kflag(s)) { |
858 | u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset); | |
859 | u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset); | |
860 | ||
861 | /* if kflag set, int should be a regular int and | |
862 | * bit offset should be at byte boundary. | |
863 | */ | |
864 | return !bitfield_size && | |
865 | BITS_ROUNDUP_BYTES(bit_offset) == expected_offset && | |
866 | BITS_ROUNDUP_BYTES(nr_bits) == expected_size; | |
867 | } | |
868 | ||
869 | if (BTF_INT_OFFSET(int_data) || | |
870 | BITS_PER_BYTE_MASKED(m->offset) || | |
871 | BITS_ROUNDUP_BYTES(m->offset) != expected_offset || | |
872 | BITS_PER_BYTE_MASKED(nr_bits) || | |
873 | BITS_ROUNDUP_BYTES(nr_bits) != expected_size) | |
9a1126b6 RG |
874 | return false; |
875 | ||
876 | return true; | |
877 | } | |
878 | ||
31d0bc81 AM |
879 | /* Similar to btf_type_skip_modifiers() but does not skip typedefs. */ |
880 | static const struct btf_type *btf_type_skip_qualifiers(const struct btf *btf, | |
881 | u32 id) | |
882 | { | |
883 | const struct btf_type *t = btf_type_by_id(btf, id); | |
884 | ||
885 | while (btf_type_is_modifier(t) && | |
886 | BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF) { | |
31d0bc81 AM |
887 | t = btf_type_by_id(btf, t->type); |
888 | } | |
889 | ||
890 | return t; | |
891 | } | |
892 | ||
893 | #define BTF_SHOW_MAX_ITER 10 | |
894 | ||
895 | #define BTF_KIND_BIT(kind) (1ULL << kind) | |
896 | ||
897 | /* | |
898 | * Populate show->state.name with type name information. | |
899 | * Format of type name is | |
900 | * | |
901 | * [.member_name = ] (type_name) | |
902 | */ | |
903 | static const char *btf_show_name(struct btf_show *show) | |
904 | { | |
905 | /* BTF_MAX_ITER array suffixes "[]" */ | |
906 | const char *array_suffixes = "[][][][][][][][][][]"; | |
907 | const char *array_suffix = &array_suffixes[strlen(array_suffixes)]; | |
908 | /* BTF_MAX_ITER pointer suffixes "*" */ | |
909 | const char *ptr_suffixes = "**********"; | |
910 | const char *ptr_suffix = &ptr_suffixes[strlen(ptr_suffixes)]; | |
911 | const char *name = NULL, *prefix = "", *parens = ""; | |
912 | const struct btf_member *m = show->state.member; | |
73b6eae5 | 913 | const struct btf_type *t; |
31d0bc81 AM |
914 | const struct btf_array *array; |
915 | u32 id = show->state.type_id; | |
916 | const char *member = NULL; | |
917 | bool show_member = false; | |
918 | u64 kinds = 0; | |
919 | int i; | |
920 | ||
921 | show->state.name[0] = '\0'; | |
922 | ||
923 | /* | |
924 | * Don't show type name if we're showing an array member; | |
925 | * in that case we show the array type so don't need to repeat | |
926 | * ourselves for each member. | |
927 | */ | |
928 | if (show->state.array_member) | |
929 | return ""; | |
930 | ||
931 | /* Retrieve member name, if any. */ | |
932 | if (m) { | |
933 | member = btf_name_by_offset(show->btf, m->name_off); | |
934 | show_member = strlen(member) > 0; | |
935 | id = m->type; | |
936 | } | |
937 | ||
938 | /* | |
939 | * Start with type_id, as we have resolved the struct btf_type * | |
940 | * via btf_modifier_show() past the parent typedef to the child | |
941 | * struct, int etc it is defined as. In such cases, the type_id | |
942 | * still represents the starting type while the struct btf_type * | |
943 | * in our show->state points at the resolved type of the typedef. | |
944 | */ | |
945 | t = btf_type_by_id(show->btf, id); | |
946 | if (!t) | |
947 | return ""; | |
948 | ||
949 | /* | |
950 | * The goal here is to build up the right number of pointer and | |
951 | * array suffixes while ensuring the type name for a typedef | |
952 | * is represented. Along the way we accumulate a list of | |
953 | * BTF kinds we have encountered, since these will inform later | |
954 | * display; for example, pointer types will not require an | |
955 | * opening "{" for struct, we will just display the pointer value. | |
956 | * | |
957 | * We also want to accumulate the right number of pointer or array | |
958 | * indices in the format string while iterating until we get to | |
959 | * the typedef/pointee/array member target type. | |
960 | * | |
961 | * We start by pointing at the end of pointer and array suffix | |
962 | * strings; as we accumulate pointers and arrays we move the pointer | |
963 | * or array string backwards so it will show the expected number of | |
964 | * '*' or '[]' for the type. BTF_SHOW_MAX_ITER of nesting of pointers | |
965 | * and/or arrays and typedefs are supported as a precaution. | |
966 | * | |
967 | * We also want to get typedef name while proceeding to resolve | |
968 | * type it points to so that we can add parentheses if it is a | |
969 | * "typedef struct" etc. | |
970 | */ | |
971 | for (i = 0; i < BTF_SHOW_MAX_ITER; i++) { | |
972 | ||
973 | switch (BTF_INFO_KIND(t->info)) { | |
974 | case BTF_KIND_TYPEDEF: | |
975 | if (!name) | |
976 | name = btf_name_by_offset(show->btf, | |
977 | t->name_off); | |
978 | kinds |= BTF_KIND_BIT(BTF_KIND_TYPEDEF); | |
979 | id = t->type; | |
980 | break; | |
981 | case BTF_KIND_ARRAY: | |
982 | kinds |= BTF_KIND_BIT(BTF_KIND_ARRAY); | |
983 | parens = "["; | |
984 | if (!t) | |
985 | return ""; | |
986 | array = btf_type_array(t); | |
987 | if (array_suffix > array_suffixes) | |
988 | array_suffix -= 2; | |
989 | id = array->type; | |
990 | break; | |
991 | case BTF_KIND_PTR: | |
992 | kinds |= BTF_KIND_BIT(BTF_KIND_PTR); | |
993 | if (ptr_suffix > ptr_suffixes) | |
994 | ptr_suffix -= 1; | |
995 | id = t->type; | |
996 | break; | |
997 | default: | |
998 | id = 0; | |
999 | break; | |
1000 | } | |
1001 | if (!id) | |
1002 | break; | |
1003 | t = btf_type_skip_qualifiers(show->btf, id); | |
1004 | } | |
1005 | /* We may not be able to represent this type; bail to be safe */ | |
1006 | if (i == BTF_SHOW_MAX_ITER) | |
1007 | return ""; | |
1008 | ||
1009 | if (!name) | |
1010 | name = btf_name_by_offset(show->btf, t->name_off); | |
1011 | ||
1012 | switch (BTF_INFO_KIND(t->info)) { | |
1013 | case BTF_KIND_STRUCT: | |
1014 | case BTF_KIND_UNION: | |
1015 | prefix = BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT ? | |
1016 | "struct" : "union"; | |
1017 | /* if it's an array of struct/union, parens is already set */ | |
1018 | if (!(kinds & (BTF_KIND_BIT(BTF_KIND_ARRAY)))) | |
1019 | parens = "{"; | |
1020 | break; | |
1021 | case BTF_KIND_ENUM: | |
6089fb32 | 1022 | case BTF_KIND_ENUM64: |
31d0bc81 AM |
1023 | prefix = "enum"; |
1024 | break; | |
1025 | default: | |
1026 | break; | |
1027 | } | |
1028 | ||
1029 | /* pointer does not require parens */ | |
1030 | if (kinds & BTF_KIND_BIT(BTF_KIND_PTR)) | |
1031 | parens = ""; | |
1032 | /* typedef does not require struct/union/enum prefix */ | |
1033 | if (kinds & BTF_KIND_BIT(BTF_KIND_TYPEDEF)) | |
1034 | prefix = ""; | |
1035 | ||
1036 | if (!name) | |
1037 | name = ""; | |
1038 | ||
1039 | /* Even if we don't want type name info, we want parentheses etc */ | |
1040 | if (show->flags & BTF_SHOW_NONAME) | |
1041 | snprintf(show->state.name, sizeof(show->state.name), "%s", | |
1042 | parens); | |
1043 | else | |
1044 | snprintf(show->state.name, sizeof(show->state.name), | |
1045 | "%s%s%s(%s%s%s%s%s%s)%s", | |
1046 | /* first 3 strings comprise ".member = " */ | |
1047 | show_member ? "." : "", | |
1048 | show_member ? member : "", | |
1049 | show_member ? " = " : "", | |
1050 | /* ...next is our prefix (struct, enum, etc) */ | |
1051 | prefix, | |
1052 | strlen(prefix) > 0 && strlen(name) > 0 ? " " : "", | |
1053 | /* ...this is the type name itself */ | |
1054 | name, | |
1055 | /* ...suffixed by the appropriate '*', '[]' suffixes */ | |
1056 | strlen(ptr_suffix) > 0 ? " " : "", ptr_suffix, | |
1057 | array_suffix, parens); | |
1058 | ||
1059 | return show->state.name; | |
1060 | } | |
1061 | ||
1062 | static const char *__btf_show_indent(struct btf_show *show) | |
1063 | { | |
1064 | const char *indents = " "; | |
1065 | const char *indent = &indents[strlen(indents)]; | |
1066 | ||
1067 | if ((indent - show->state.depth) >= indents) | |
1068 | return indent - show->state.depth; | |
1069 | return indents; | |
1070 | } | |
1071 | ||
1072 | static const char *btf_show_indent(struct btf_show *show) | |
1073 | { | |
1074 | return show->flags & BTF_SHOW_COMPACT ? "" : __btf_show_indent(show); | |
1075 | } | |
1076 | ||
1077 | static const char *btf_show_newline(struct btf_show *show) | |
1078 | { | |
1079 | return show->flags & BTF_SHOW_COMPACT ? "" : "\n"; | |
1080 | } | |
1081 | ||
1082 | static const char *btf_show_delim(struct btf_show *show) | |
1083 | { | |
1084 | if (show->state.depth == 0) | |
1085 | return ""; | |
1086 | ||
1087 | if ((show->flags & BTF_SHOW_COMPACT) && show->state.type && | |
1088 | BTF_INFO_KIND(show->state.type->info) == BTF_KIND_UNION) | |
1089 | return "|"; | |
1090 | ||
1091 | return ","; | |
1092 | } | |
1093 | ||
1094 | __printf(2, 3) static void btf_show(struct btf_show *show, const char *fmt, ...) | |
1095 | { | |
1096 | va_list args; | |
1097 | ||
1098 | if (!show->state.depth_check) { | |
1099 | va_start(args, fmt); | |
1100 | show->showfn(show, fmt, args); | |
1101 | va_end(args); | |
1102 | } | |
1103 | } | |
1104 | ||
1105 | /* Macros are used here as btf_show_type_value[s]() prepends and appends | |
1106 | * format specifiers to the format specifier passed in; these do the work of | |
1107 | * adding indentation, delimiters etc while the caller simply has to specify | |
1108 | * the type value(s) in the format specifier + value(s). | |
1109 | */ | |
1110 | #define btf_show_type_value(show, fmt, value) \ | |
1111 | do { \ | |
a2a5580f BD |
1112 | if ((value) != (__typeof__(value))0 || \ |
1113 | (show->flags & BTF_SHOW_ZERO) || \ | |
31d0bc81 AM |
1114 | show->state.depth == 0) { \ |
1115 | btf_show(show, "%s%s" fmt "%s%s", \ | |
1116 | btf_show_indent(show), \ | |
1117 | btf_show_name(show), \ | |
1118 | value, btf_show_delim(show), \ | |
1119 | btf_show_newline(show)); \ | |
1120 | if (show->state.depth > show->state.depth_to_show) \ | |
1121 | show->state.depth_to_show = show->state.depth; \ | |
1122 | } \ | |
1123 | } while (0) | |
1124 | ||
1125 | #define btf_show_type_values(show, fmt, ...) \ | |
1126 | do { \ | |
1127 | btf_show(show, "%s%s" fmt "%s%s", btf_show_indent(show), \ | |
1128 | btf_show_name(show), \ | |
1129 | __VA_ARGS__, btf_show_delim(show), \ | |
1130 | btf_show_newline(show)); \ | |
1131 | if (show->state.depth > show->state.depth_to_show) \ | |
1132 | show->state.depth_to_show = show->state.depth; \ | |
1133 | } while (0) | |
1134 | ||
1135 | /* How much is left to copy to safe buffer after @data? */ | |
1136 | static int btf_show_obj_size_left(struct btf_show *show, void *data) | |
1137 | { | |
1138 | return show->obj.head + show->obj.size - data; | |
1139 | } | |
1140 | ||
1141 | /* Is object pointed to by @data of @size already copied to our safe buffer? */ | |
1142 | static bool btf_show_obj_is_safe(struct btf_show *show, void *data, int size) | |
1143 | { | |
1144 | return data >= show->obj.data && | |
1145 | (data + size) < (show->obj.data + BTF_SHOW_OBJ_SAFE_SIZE); | |
1146 | } | |
1147 | ||
1148 | /* | |
1149 | * If object pointed to by @data of @size falls within our safe buffer, return | |
1150 | * the equivalent pointer to the same safe data. Assumes | |
1151 | * copy_from_kernel_nofault() has already happened and our safe buffer is | |
1152 | * populated. | |
1153 | */ | |
1154 | static void *__btf_show_obj_safe(struct btf_show *show, void *data, int size) | |
1155 | { | |
1156 | if (btf_show_obj_is_safe(show, data, size)) | |
1157 | return show->obj.safe + (data - show->obj.data); | |
1158 | return NULL; | |
1159 | } | |
1160 | ||
1161 | /* | |
1162 | * Return a safe-to-access version of data pointed to by @data. | |
1163 | * We do this by copying the relevant amount of information | |
1164 | * to the struct btf_show obj.safe buffer using copy_from_kernel_nofault(). | |
1165 | * | |
1166 | * If BTF_SHOW_UNSAFE is specified, just return data as-is; no | |
1167 | * safe copy is needed. | |
1168 | * | |
1169 | * Otherwise we need to determine if we have the required amount | |
1170 | * of data (determined by the @data pointer and the size of the | |
1171 | * largest base type we can encounter (represented by | |
1172 | * BTF_SHOW_OBJ_BASE_TYPE_SIZE). Having that much data ensures | |
1173 | * that we will be able to print some of the current object, | |
1174 | * and if more is needed a copy will be triggered. | |
1175 | * Some objects such as structs will not fit into the buffer; | |
1176 | * in such cases additional copies when we iterate over their | |
1177 | * members may be needed. | |
1178 | * | |
1179 | * btf_show_obj_safe() is used to return a safe buffer for | |
1180 | * btf_show_start_type(); this ensures that as we recurse into | |
1181 | * nested types we always have safe data for the given type. | |
1182 | * This approach is somewhat wasteful; it's possible for example | |
1183 | * that when iterating over a large union we'll end up copying the | |
1184 | * same data repeatedly, but the goal is safety not performance. | |
1185 | * We use stack data as opposed to per-CPU buffers because the | |
1186 | * iteration over a type can take some time, and preemption handling | |
1187 | * would greatly complicate use of the safe buffer. | |
1188 | */ | |
1189 | static void *btf_show_obj_safe(struct btf_show *show, | |
1190 | const struct btf_type *t, | |
1191 | void *data) | |
1192 | { | |
1193 | const struct btf_type *rt; | |
1194 | int size_left, size; | |
1195 | void *safe = NULL; | |
1196 | ||
1197 | if (show->flags & BTF_SHOW_UNSAFE) | |
1198 | return data; | |
1199 | ||
1200 | rt = btf_resolve_size(show->btf, t, &size); | |
1201 | if (IS_ERR(rt)) { | |
1202 | show->state.status = PTR_ERR(rt); | |
1203 | return NULL; | |
1204 | } | |
1205 | ||
1206 | /* | |
1207 | * Is this toplevel object? If so, set total object size and | |
1208 | * initialize pointers. Otherwise check if we still fall within | |
1209 | * our safe object data. | |
1210 | */ | |
1211 | if (show->state.depth == 0) { | |
1212 | show->obj.size = size; | |
1213 | show->obj.head = data; | |
1214 | } else { | |
1215 | /* | |
1216 | * If the size of the current object is > our remaining | |
1217 | * safe buffer we _may_ need to do a new copy. However | |
1218 | * consider the case of a nested struct; it's size pushes | |
1219 | * us over the safe buffer limit, but showing any individual | |
1220 | * struct members does not. In such cases, we don't need | |
1221 | * to initiate a fresh copy yet; however we definitely need | |
1222 | * at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes left | |
1223 | * in our buffer, regardless of the current object size. | |
1224 | * The logic here is that as we resolve types we will | |
1225 | * hit a base type at some point, and we need to be sure | |
1226 | * the next chunk of data is safely available to display | |
1227 | * that type info safely. We cannot rely on the size of | |
1228 | * the current object here because it may be much larger | |
1229 | * than our current buffer (e.g. task_struct is 8k). | |
1230 | * All we want to do here is ensure that we can print the | |
1231 | * next basic type, which we can if either | |
1232 | * - the current type size is within the safe buffer; or | |
1233 | * - at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes are left in | |
1234 | * the safe buffer. | |
1235 | */ | |
1236 | safe = __btf_show_obj_safe(show, data, | |
1237 | min(size, | |
1238 | BTF_SHOW_OBJ_BASE_TYPE_SIZE)); | |
1239 | } | |
1240 | ||
1241 | /* | |
1242 | * We need a new copy to our safe object, either because we haven't | |
8fb33b60 | 1243 | * yet copied and are initializing safe data, or because the data |
31d0bc81 AM |
1244 | * we want falls outside the boundaries of the safe object. |
1245 | */ | |
1246 | if (!safe) { | |
1247 | size_left = btf_show_obj_size_left(show, data); | |
1248 | if (size_left > BTF_SHOW_OBJ_SAFE_SIZE) | |
1249 | size_left = BTF_SHOW_OBJ_SAFE_SIZE; | |
1250 | show->state.status = copy_from_kernel_nofault(show->obj.safe, | |
1251 | data, size_left); | |
1252 | if (!show->state.status) { | |
1253 | show->obj.data = data; | |
1254 | safe = show->obj.safe; | |
1255 | } | |
1256 | } | |
1257 | ||
1258 | return safe; | |
1259 | } | |
1260 | ||
1261 | /* | |
1262 | * Set the type we are starting to show and return a safe data pointer | |
1263 | * to be used for showing the associated data. | |
1264 | */ | |
1265 | static void *btf_show_start_type(struct btf_show *show, | |
1266 | const struct btf_type *t, | |
1267 | u32 type_id, void *data) | |
1268 | { | |
1269 | show->state.type = t; | |
1270 | show->state.type_id = type_id; | |
1271 | show->state.name[0] = '\0'; | |
1272 | ||
1273 | return btf_show_obj_safe(show, t, data); | |
1274 | } | |
1275 | ||
1276 | static void btf_show_end_type(struct btf_show *show) | |
1277 | { | |
1278 | show->state.type = NULL; | |
1279 | show->state.type_id = 0; | |
1280 | show->state.name[0] = '\0'; | |
1281 | } | |
1282 | ||
1283 | static void *btf_show_start_aggr_type(struct btf_show *show, | |
1284 | const struct btf_type *t, | |
1285 | u32 type_id, void *data) | |
1286 | { | |
1287 | void *safe_data = btf_show_start_type(show, t, type_id, data); | |
1288 | ||
1289 | if (!safe_data) | |
1290 | return safe_data; | |
1291 | ||
1292 | btf_show(show, "%s%s%s", btf_show_indent(show), | |
1293 | btf_show_name(show), | |
1294 | btf_show_newline(show)); | |
1295 | show->state.depth++; | |
1296 | return safe_data; | |
1297 | } | |
1298 | ||
1299 | static void btf_show_end_aggr_type(struct btf_show *show, | |
1300 | const char *suffix) | |
1301 | { | |
1302 | show->state.depth--; | |
1303 | btf_show(show, "%s%s%s%s", btf_show_indent(show), suffix, | |
1304 | btf_show_delim(show), btf_show_newline(show)); | |
1305 | btf_show_end_type(show); | |
1306 | } | |
1307 | ||
1308 | static void btf_show_start_member(struct btf_show *show, | |
1309 | const struct btf_member *m) | |
1310 | { | |
1311 | show->state.member = m; | |
1312 | } | |
1313 | ||
1314 | static void btf_show_start_array_member(struct btf_show *show) | |
1315 | { | |
1316 | show->state.array_member = 1; | |
1317 | btf_show_start_member(show, NULL); | |
1318 | } | |
1319 | ||
1320 | static void btf_show_end_member(struct btf_show *show) | |
1321 | { | |
1322 | show->state.member = NULL; | |
1323 | } | |
1324 | ||
1325 | static void btf_show_end_array_member(struct btf_show *show) | |
1326 | { | |
1327 | show->state.array_member = 0; | |
1328 | btf_show_end_member(show); | |
1329 | } | |
1330 | ||
1331 | static void *btf_show_start_array_type(struct btf_show *show, | |
1332 | const struct btf_type *t, | |
1333 | u32 type_id, | |
1334 | u16 array_encoding, | |
1335 | void *data) | |
1336 | { | |
1337 | show->state.array_encoding = array_encoding; | |
1338 | show->state.array_terminated = 0; | |
1339 | return btf_show_start_aggr_type(show, t, type_id, data); | |
1340 | } | |
1341 | ||
1342 | static void btf_show_end_array_type(struct btf_show *show) | |
1343 | { | |
1344 | show->state.array_encoding = 0; | |
1345 | show->state.array_terminated = 0; | |
1346 | btf_show_end_aggr_type(show, "]"); | |
1347 | } | |
1348 | ||
1349 | static void *btf_show_start_struct_type(struct btf_show *show, | |
1350 | const struct btf_type *t, | |
1351 | u32 type_id, | |
1352 | void *data) | |
1353 | { | |
1354 | return btf_show_start_aggr_type(show, t, type_id, data); | |
1355 | } | |
1356 | ||
1357 | static void btf_show_end_struct_type(struct btf_show *show) | |
1358 | { | |
1359 | btf_show_end_aggr_type(show, "}"); | |
1360 | } | |
1361 | ||
69b693f0 MKL |
1362 | __printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log, |
1363 | const char *fmt, ...) | |
1364 | { | |
1365 | va_list args; | |
1366 | ||
1367 | va_start(args, fmt); | |
1368 | bpf_verifier_vlog(log, fmt, args); | |
1369 | va_end(args); | |
1370 | } | |
1371 | ||
1372 | __printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env, | |
1373 | const char *fmt, ...) | |
1374 | { | |
1375 | struct bpf_verifier_log *log = &env->log; | |
1376 | va_list args; | |
1377 | ||
1378 | if (!bpf_verifier_log_needed(log)) | |
1379 | return; | |
1380 | ||
1381 | va_start(args, fmt); | |
1382 | bpf_verifier_vlog(log, fmt, args); | |
1383 | va_end(args); | |
1384 | } | |
1385 | ||
1386 | __printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env, | |
1387 | const struct btf_type *t, | |
1388 | bool log_details, | |
1389 | const char *fmt, ...) | |
1390 | { | |
1391 | struct bpf_verifier_log *log = &env->log; | |
69b693f0 MKL |
1392 | struct btf *btf = env->btf; |
1393 | va_list args; | |
1394 | ||
1395 | if (!bpf_verifier_log_needed(log)) | |
1396 | return; | |
1397 | ||
8580ac94 AS |
1398 | /* btf verifier prints all types it is processing via |
1399 | * btf_verifier_log_type(..., fmt = NULL). | |
1400 | * Skip those prints for in-kernel BTF verification. | |
1401 | */ | |
1402 | if (log->level == BPF_LOG_KERNEL && !fmt) | |
1403 | return; | |
1404 | ||
69b693f0 MKL |
1405 | __btf_verifier_log(log, "[%u] %s %s%s", |
1406 | env->log_type_id, | |
571f9738 | 1407 | btf_type_str(t), |
23127b33 | 1408 | __btf_name_by_offset(btf, t->name_off), |
69b693f0 MKL |
1409 | log_details ? " " : ""); |
1410 | ||
1411 | if (log_details) | |
1412 | btf_type_ops(t)->log_details(env, t); | |
1413 | ||
1414 | if (fmt && *fmt) { | |
1415 | __btf_verifier_log(log, " "); | |
1416 | va_start(args, fmt); | |
1417 | bpf_verifier_vlog(log, fmt, args); | |
1418 | va_end(args); | |
1419 | } | |
1420 | ||
1421 | __btf_verifier_log(log, "\n"); | |
1422 | } | |
1423 | ||
1424 | #define btf_verifier_log_type(env, t, ...) \ | |
1425 | __btf_verifier_log_type((env), (t), true, __VA_ARGS__) | |
1426 | #define btf_verifier_log_basic(env, t, ...) \ | |
1427 | __btf_verifier_log_type((env), (t), false, __VA_ARGS__) | |
1428 | ||
1429 | __printf(4, 5) | |
1430 | static void btf_verifier_log_member(struct btf_verifier_env *env, | |
1431 | const struct btf_type *struct_type, | |
1432 | const struct btf_member *member, | |
1433 | const char *fmt, ...) | |
1434 | { | |
1435 | struct bpf_verifier_log *log = &env->log; | |
1436 | struct btf *btf = env->btf; | |
1437 | va_list args; | |
1438 | ||
1439 | if (!bpf_verifier_log_needed(log)) | |
1440 | return; | |
1441 | ||
8580ac94 AS |
1442 | if (log->level == BPF_LOG_KERNEL && !fmt) |
1443 | return; | |
eb3f595d MKL |
1444 | /* The CHECK_META phase already did a btf dump. |
1445 | * | |
1446 | * If member is logged again, it must hit an error in | |
1447 | * parsing this member. It is useful to print out which | |
1448 | * struct this member belongs to. | |
1449 | */ | |
1450 | if (env->phase != CHECK_META) | |
1451 | btf_verifier_log_type(env, struct_type, NULL); | |
1452 | ||
9d5f9f70 YS |
1453 | if (btf_type_kflag(struct_type)) |
1454 | __btf_verifier_log(log, | |
1455 | "\t%s type_id=%u bitfield_size=%u bits_offset=%u", | |
1456 | __btf_name_by_offset(btf, member->name_off), | |
1457 | member->type, | |
1458 | BTF_MEMBER_BITFIELD_SIZE(member->offset), | |
1459 | BTF_MEMBER_BIT_OFFSET(member->offset)); | |
1460 | else | |
1461 | __btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u", | |
1462 | __btf_name_by_offset(btf, member->name_off), | |
1463 | member->type, member->offset); | |
69b693f0 MKL |
1464 | |
1465 | if (fmt && *fmt) { | |
1466 | __btf_verifier_log(log, " "); | |
1467 | va_start(args, fmt); | |
1468 | bpf_verifier_vlog(log, fmt, args); | |
1469 | va_end(args); | |
1470 | } | |
1471 | ||
1472 | __btf_verifier_log(log, "\n"); | |
1473 | } | |
1474 | ||
1dc92851 DB |
1475 | __printf(4, 5) |
1476 | static void btf_verifier_log_vsi(struct btf_verifier_env *env, | |
1477 | const struct btf_type *datasec_type, | |
1478 | const struct btf_var_secinfo *vsi, | |
1479 | const char *fmt, ...) | |
1480 | { | |
1481 | struct bpf_verifier_log *log = &env->log; | |
1482 | va_list args; | |
1483 | ||
1484 | if (!bpf_verifier_log_needed(log)) | |
1485 | return; | |
8580ac94 AS |
1486 | if (log->level == BPF_LOG_KERNEL && !fmt) |
1487 | return; | |
1dc92851 DB |
1488 | if (env->phase != CHECK_META) |
1489 | btf_verifier_log_type(env, datasec_type, NULL); | |
1490 | ||
1491 | __btf_verifier_log(log, "\t type_id=%u offset=%u size=%u", | |
1492 | vsi->type, vsi->offset, vsi->size); | |
1493 | if (fmt && *fmt) { | |
1494 | __btf_verifier_log(log, " "); | |
1495 | va_start(args, fmt); | |
1496 | bpf_verifier_vlog(log, fmt, args); | |
1497 | va_end(args); | |
1498 | } | |
1499 | ||
1500 | __btf_verifier_log(log, "\n"); | |
1501 | } | |
1502 | ||
f80442a4 MKL |
1503 | static void btf_verifier_log_hdr(struct btf_verifier_env *env, |
1504 | u32 btf_data_size) | |
69b693f0 MKL |
1505 | { |
1506 | struct bpf_verifier_log *log = &env->log; | |
1507 | const struct btf *btf = env->btf; | |
1508 | const struct btf_header *hdr; | |
1509 | ||
1510 | if (!bpf_verifier_log_needed(log)) | |
1511 | return; | |
1512 | ||
8580ac94 AS |
1513 | if (log->level == BPF_LOG_KERNEL) |
1514 | return; | |
f80442a4 | 1515 | hdr = &btf->hdr; |
69b693f0 MKL |
1516 | __btf_verifier_log(log, "magic: 0x%x\n", hdr->magic); |
1517 | __btf_verifier_log(log, "version: %u\n", hdr->version); | |
1518 | __btf_verifier_log(log, "flags: 0x%x\n", hdr->flags); | |
f80442a4 | 1519 | __btf_verifier_log(log, "hdr_len: %u\n", hdr->hdr_len); |
69b693f0 | 1520 | __btf_verifier_log(log, "type_off: %u\n", hdr->type_off); |
f80442a4 | 1521 | __btf_verifier_log(log, "type_len: %u\n", hdr->type_len); |
69b693f0 MKL |
1522 | __btf_verifier_log(log, "str_off: %u\n", hdr->str_off); |
1523 | __btf_verifier_log(log, "str_len: %u\n", hdr->str_len); | |
f80442a4 | 1524 | __btf_verifier_log(log, "btf_total_size: %u\n", btf_data_size); |
69b693f0 MKL |
1525 | } |
1526 | ||
1527 | static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t) | |
1528 | { | |
1529 | struct btf *btf = env->btf; | |
1530 | ||
951bb646 | 1531 | if (btf->types_size == btf->nr_types) { |
69b693f0 MKL |
1532 | /* Expand 'types' array */ |
1533 | ||
1534 | struct btf_type **new_types; | |
1535 | u32 expand_by, new_size; | |
1536 | ||
951bb646 | 1537 | if (btf->start_id + btf->types_size == BTF_MAX_TYPE) { |
69b693f0 MKL |
1538 | btf_verifier_log(env, "Exceeded max num of types"); |
1539 | return -E2BIG; | |
1540 | } | |
1541 | ||
1542 | expand_by = max_t(u32, btf->types_size >> 2, 16); | |
aea2f7b8 | 1543 | new_size = min_t(u32, BTF_MAX_TYPE, |
69b693f0 MKL |
1544 | btf->types_size + expand_by); |
1545 | ||
778e1cdd | 1546 | new_types = kvcalloc(new_size, sizeof(*new_types), |
69b693f0 MKL |
1547 | GFP_KERNEL | __GFP_NOWARN); |
1548 | if (!new_types) | |
1549 | return -ENOMEM; | |
1550 | ||
951bb646 AN |
1551 | if (btf->nr_types == 0) { |
1552 | if (!btf->base_btf) { | |
1553 | /* lazily init VOID type */ | |
1554 | new_types[0] = &btf_void; | |
1555 | btf->nr_types++; | |
1556 | } | |
1557 | } else { | |
69b693f0 | 1558 | memcpy(new_types, btf->types, |
951bb646 AN |
1559 | sizeof(*btf->types) * btf->nr_types); |
1560 | } | |
69b693f0 MKL |
1561 | |
1562 | kvfree(btf->types); | |
1563 | btf->types = new_types; | |
1564 | btf->types_size = new_size; | |
1565 | } | |
1566 | ||
951bb646 | 1567 | btf->types[btf->nr_types++] = t; |
69b693f0 MKL |
1568 | |
1569 | return 0; | |
1570 | } | |
1571 | ||
78958fca MKL |
1572 | static int btf_alloc_id(struct btf *btf) |
1573 | { | |
1574 | int id; | |
1575 | ||
1576 | idr_preload(GFP_KERNEL); | |
1577 | spin_lock_bh(&btf_idr_lock); | |
1578 | id = idr_alloc_cyclic(&btf_idr, btf, 1, INT_MAX, GFP_ATOMIC); | |
1579 | if (id > 0) | |
1580 | btf->id = id; | |
1581 | spin_unlock_bh(&btf_idr_lock); | |
1582 | idr_preload_end(); | |
1583 | ||
1584 | if (WARN_ON_ONCE(!id)) | |
1585 | return -ENOSPC; | |
1586 | ||
1587 | return id > 0 ? 0 : id; | |
1588 | } | |
1589 | ||
1590 | static void btf_free_id(struct btf *btf) | |
1591 | { | |
1592 | unsigned long flags; | |
1593 | ||
1594 | /* | |
1595 | * In map-in-map, calling map_delete_elem() on outer | |
1596 | * map will call bpf_map_put on the inner map. | |
1597 | * It will then eventually call btf_free_id() | |
1598 | * on the inner map. Some of the map_delete_elem() | |
1599 | * implementation may have irq disabled, so | |
1600 | * we need to use the _irqsave() version instead | |
1601 | * of the _bh() version. | |
1602 | */ | |
1603 | spin_lock_irqsave(&btf_idr_lock, flags); | |
1604 | idr_remove(&btf_idr, btf->id); | |
1605 | spin_unlock_irqrestore(&btf_idr_lock, flags); | |
1606 | } | |
1607 | ||
dee872e1 KKD |
1608 | static void btf_free_kfunc_set_tab(struct btf *btf) |
1609 | { | |
1610 | struct btf_kfunc_set_tab *tab = btf->kfunc_set_tab; | |
a4703e31 | 1611 | int hook; |
dee872e1 KKD |
1612 | |
1613 | if (!tab) | |
1614 | return; | |
1615 | /* For module BTF, we directly assign the sets being registered, so | |
1616 | * there is nothing to free except kfunc_set_tab. | |
1617 | */ | |
1618 | if (btf_is_module(btf)) | |
1619 | goto free_tab; | |
a4703e31 KKD |
1620 | for (hook = 0; hook < ARRAY_SIZE(tab->sets); hook++) |
1621 | kfree(tab->sets[hook]); | |
dee872e1 KKD |
1622 | free_tab: |
1623 | kfree(tab); | |
1624 | btf->kfunc_set_tab = NULL; | |
1625 | } | |
1626 | ||
5ce937d6 KKD |
1627 | static void btf_free_dtor_kfunc_tab(struct btf *btf) |
1628 | { | |
1629 | struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab; | |
1630 | ||
1631 | if (!tab) | |
1632 | return; | |
1633 | kfree(tab); | |
1634 | btf->dtor_kfunc_tab = NULL; | |
1635 | } | |
1636 | ||
8ffa5cc1 KKD |
1637 | static void btf_struct_metas_free(struct btf_struct_metas *tab) |
1638 | { | |
1639 | int i; | |
1640 | ||
1641 | if (!tab) | |
1642 | return; | |
1643 | for (i = 0; i < tab->cnt; i++) { | |
1644 | btf_record_free(tab->types[i].record); | |
1645 | kfree(tab->types[i].field_offs); | |
1646 | } | |
1647 | kfree(tab); | |
1648 | } | |
1649 | ||
1650 | static void btf_free_struct_meta_tab(struct btf *btf) | |
1651 | { | |
1652 | struct btf_struct_metas *tab = btf->struct_meta_tab; | |
1653 | ||
1654 | btf_struct_metas_free(tab); | |
1655 | btf->struct_meta_tab = NULL; | |
1656 | } | |
1657 | ||
69b693f0 MKL |
1658 | static void btf_free(struct btf *btf) |
1659 | { | |
8ffa5cc1 | 1660 | btf_free_struct_meta_tab(btf); |
5ce937d6 | 1661 | btf_free_dtor_kfunc_tab(btf); |
dee872e1 | 1662 | btf_free_kfunc_set_tab(btf); |
69b693f0 | 1663 | kvfree(btf->types); |
eb3f595d MKL |
1664 | kvfree(btf->resolved_sizes); |
1665 | kvfree(btf->resolved_ids); | |
69b693f0 MKL |
1666 | kvfree(btf->data); |
1667 | kfree(btf); | |
1668 | } | |
1669 | ||
78958fca | 1670 | static void btf_free_rcu(struct rcu_head *rcu) |
f56a653c | 1671 | { |
78958fca MKL |
1672 | struct btf *btf = container_of(rcu, struct btf, rcu); |
1673 | ||
1674 | btf_free(btf); | |
f56a653c MKL |
1675 | } |
1676 | ||
22dc4a0f AN |
1677 | void btf_get(struct btf *btf) |
1678 | { | |
1679 | refcount_inc(&btf->refcnt); | |
1680 | } | |
1681 | ||
f56a653c MKL |
1682 | void btf_put(struct btf *btf) |
1683 | { | |
78958fca MKL |
1684 | if (btf && refcount_dec_and_test(&btf->refcnt)) { |
1685 | btf_free_id(btf); | |
1686 | call_rcu(&btf->rcu, btf_free_rcu); | |
1687 | } | |
f56a653c MKL |
1688 | } |
1689 | ||
eb3f595d MKL |
1690 | static int env_resolve_init(struct btf_verifier_env *env) |
1691 | { | |
1692 | struct btf *btf = env->btf; | |
1693 | u32 nr_types = btf->nr_types; | |
1694 | u32 *resolved_sizes = NULL; | |
1695 | u32 *resolved_ids = NULL; | |
1696 | u8 *visit_states = NULL; | |
1697 | ||
951bb646 | 1698 | resolved_sizes = kvcalloc(nr_types, sizeof(*resolved_sizes), |
eb3f595d MKL |
1699 | GFP_KERNEL | __GFP_NOWARN); |
1700 | if (!resolved_sizes) | |
1701 | goto nomem; | |
1702 | ||
951bb646 | 1703 | resolved_ids = kvcalloc(nr_types, sizeof(*resolved_ids), |
eb3f595d MKL |
1704 | GFP_KERNEL | __GFP_NOWARN); |
1705 | if (!resolved_ids) | |
1706 | goto nomem; | |
1707 | ||
951bb646 | 1708 | visit_states = kvcalloc(nr_types, sizeof(*visit_states), |
eb3f595d MKL |
1709 | GFP_KERNEL | __GFP_NOWARN); |
1710 | if (!visit_states) | |
1711 | goto nomem; | |
1712 | ||
1713 | btf->resolved_sizes = resolved_sizes; | |
1714 | btf->resolved_ids = resolved_ids; | |
1715 | env->visit_states = visit_states; | |
1716 | ||
1717 | return 0; | |
1718 | ||
1719 | nomem: | |
1720 | kvfree(resolved_sizes); | |
1721 | kvfree(resolved_ids); | |
1722 | kvfree(visit_states); | |
1723 | return -ENOMEM; | |
1724 | } | |
1725 | ||
69b693f0 MKL |
1726 | static void btf_verifier_env_free(struct btf_verifier_env *env) |
1727 | { | |
eb3f595d | 1728 | kvfree(env->visit_states); |
69b693f0 MKL |
1729 | kfree(env); |
1730 | } | |
1731 | ||
eb3f595d MKL |
1732 | static bool env_type_is_resolve_sink(const struct btf_verifier_env *env, |
1733 | const struct btf_type *next_type) | |
1734 | { | |
1735 | switch (env->resolve_mode) { | |
1736 | case RESOLVE_TBD: | |
1737 | /* int, enum or void is a sink */ | |
1738 | return !btf_type_needs_resolve(next_type); | |
1739 | case RESOLVE_PTR: | |
2667a262 MKL |
1740 | /* int, enum, void, struct, array, func or func_proto is a sink |
1741 | * for ptr | |
1742 | */ | |
eb3f595d MKL |
1743 | return !btf_type_is_modifier(next_type) && |
1744 | !btf_type_is_ptr(next_type); | |
1745 | case RESOLVE_STRUCT_OR_ARRAY: | |
2667a262 MKL |
1746 | /* int, enum, void, ptr, func or func_proto is a sink |
1747 | * for struct and array | |
1748 | */ | |
eb3f595d MKL |
1749 | return !btf_type_is_modifier(next_type) && |
1750 | !btf_type_is_array(next_type) && | |
1751 | !btf_type_is_struct(next_type); | |
1752 | default: | |
53c8036c | 1753 | BUG(); |
eb3f595d MKL |
1754 | } |
1755 | } | |
1756 | ||
1757 | static bool env_type_is_resolved(const struct btf_verifier_env *env, | |
1758 | u32 type_id) | |
1759 | { | |
951bb646 AN |
1760 | /* base BTF types should be resolved by now */ |
1761 | if (type_id < env->btf->start_id) | |
1762 | return true; | |
1763 | ||
1764 | return env->visit_states[type_id - env->btf->start_id] == RESOLVED; | |
eb3f595d MKL |
1765 | } |
1766 | ||
1767 | static int env_stack_push(struct btf_verifier_env *env, | |
1768 | const struct btf_type *t, u32 type_id) | |
1769 | { | |
951bb646 | 1770 | const struct btf *btf = env->btf; |
eb3f595d MKL |
1771 | struct resolve_vertex *v; |
1772 | ||
1773 | if (env->top_stack == MAX_RESOLVE_DEPTH) | |
1774 | return -E2BIG; | |
1775 | ||
951bb646 AN |
1776 | if (type_id < btf->start_id |
1777 | || env->visit_states[type_id - btf->start_id] != NOT_VISITED) | |
eb3f595d MKL |
1778 | return -EEXIST; |
1779 | ||
951bb646 | 1780 | env->visit_states[type_id - btf->start_id] = VISITED; |
eb3f595d MKL |
1781 | |
1782 | v = &env->stack[env->top_stack++]; | |
1783 | v->t = t; | |
1784 | v->type_id = type_id; | |
1785 | v->next_member = 0; | |
1786 | ||
1787 | if (env->resolve_mode == RESOLVE_TBD) { | |
1788 | if (btf_type_is_ptr(t)) | |
1789 | env->resolve_mode = RESOLVE_PTR; | |
1790 | else if (btf_type_is_struct(t) || btf_type_is_array(t)) | |
1791 | env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY; | |
1792 | } | |
1793 | ||
1794 | return 0; | |
1795 | } | |
1796 | ||
1797 | static void env_stack_set_next_member(struct btf_verifier_env *env, | |
1798 | u16 next_member) | |
1799 | { | |
1800 | env->stack[env->top_stack - 1].next_member = next_member; | |
1801 | } | |
1802 | ||
1803 | static void env_stack_pop_resolved(struct btf_verifier_env *env, | |
1804 | u32 resolved_type_id, | |
1805 | u32 resolved_size) | |
1806 | { | |
1807 | u32 type_id = env->stack[--(env->top_stack)].type_id; | |
1808 | struct btf *btf = env->btf; | |
1809 | ||
951bb646 | 1810 | type_id -= btf->start_id; /* adjust to local type id */ |
eb3f595d MKL |
1811 | btf->resolved_sizes[type_id] = resolved_size; |
1812 | btf->resolved_ids[type_id] = resolved_type_id; | |
1813 | env->visit_states[type_id] = RESOLVED; | |
1814 | } | |
1815 | ||
1816 | static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env) | |
1817 | { | |
1818 | return env->top_stack ? &env->stack[env->top_stack - 1] : NULL; | |
1819 | } | |
1820 | ||
7e3617a7 MKL |
1821 | /* Resolve the size of a passed-in "type" |
1822 | * | |
1823 | * type: is an array (e.g. u32 array[x][y]) | |
1824 | * return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY, | |
1825 | * *type_size: (x * y * sizeof(u32)). Hence, *type_size always | |
1826 | * corresponds to the return type. | |
1827 | * *elem_type: u32 | |
69ff3047 | 1828 | * *elem_id: id of u32 |
7e3617a7 MKL |
1829 | * *total_nelems: (x * y). Hence, individual elem size is |
1830 | * (*type_size / *total_nelems) | |
887c31a3 | 1831 | * *type_id: id of type if it's changed within the function, 0 if not |
7e3617a7 MKL |
1832 | * |
1833 | * type: is not an array (e.g. const struct X) | |
1834 | * return type: type "struct X" | |
1835 | * *type_size: sizeof(struct X) | |
1836 | * *elem_type: same as return type ("struct X") | |
69ff3047 | 1837 | * *elem_id: 0 |
7e3617a7 | 1838 | * *total_nelems: 1 |
887c31a3 | 1839 | * *type_id: id of type if it's changed within the function, 0 if not |
7e3617a7 | 1840 | */ |
6298399b JO |
1841 | static const struct btf_type * |
1842 | __btf_resolve_size(const struct btf *btf, const struct btf_type *type, | |
1843 | u32 *type_size, const struct btf_type **elem_type, | |
887c31a3 | 1844 | u32 *elem_id, u32 *total_nelems, u32 *type_id) |
7e3617a7 MKL |
1845 | { |
1846 | const struct btf_type *array_type = NULL; | |
69ff3047 | 1847 | const struct btf_array *array = NULL; |
887c31a3 | 1848 | u32 i, size, nelems = 1, id = 0; |
7e3617a7 MKL |
1849 | |
1850 | for (i = 0; i < MAX_RESOLVE_DEPTH; i++) { | |
1851 | switch (BTF_INFO_KIND(type->info)) { | |
1852 | /* type->size can be used */ | |
1853 | case BTF_KIND_INT: | |
1854 | case BTF_KIND_STRUCT: | |
1855 | case BTF_KIND_UNION: | |
1856 | case BTF_KIND_ENUM: | |
b1828f0b | 1857 | case BTF_KIND_FLOAT: |
6089fb32 | 1858 | case BTF_KIND_ENUM64: |
7e3617a7 MKL |
1859 | size = type->size; |
1860 | goto resolved; | |
1861 | ||
1862 | case BTF_KIND_PTR: | |
1863 | size = sizeof(void *); | |
1864 | goto resolved; | |
1865 | ||
1866 | /* Modifiers */ | |
1867 | case BTF_KIND_TYPEDEF: | |
1868 | case BTF_KIND_VOLATILE: | |
1869 | case BTF_KIND_CONST: | |
1870 | case BTF_KIND_RESTRICT: | |
8c42d2fa | 1871 | case BTF_KIND_TYPE_TAG: |
887c31a3 | 1872 | id = type->type; |
7e3617a7 MKL |
1873 | type = btf_type_by_id(btf, type->type); |
1874 | break; | |
1875 | ||
1876 | case BTF_KIND_ARRAY: | |
1877 | if (!array_type) | |
1878 | array_type = type; | |
1879 | array = btf_type_array(type); | |
1880 | if (nelems && array->nelems > U32_MAX / nelems) | |
1881 | return ERR_PTR(-EINVAL); | |
1882 | nelems *= array->nelems; | |
1883 | type = btf_type_by_id(btf, array->type); | |
1884 | break; | |
1885 | ||
1886 | /* type without size */ | |
1887 | default: | |
1888 | return ERR_PTR(-EINVAL); | |
1889 | } | |
1890 | } | |
1891 | ||
1892 | return ERR_PTR(-EINVAL); | |
1893 | ||
1894 | resolved: | |
1895 | if (nelems && size > U32_MAX / nelems) | |
1896 | return ERR_PTR(-EINVAL); | |
1897 | ||
1898 | *type_size = nelems * size; | |
85d33df3 MKL |
1899 | if (total_nelems) |
1900 | *total_nelems = nelems; | |
1901 | if (elem_type) | |
1902 | *elem_type = type; | |
69ff3047 JO |
1903 | if (elem_id) |
1904 | *elem_id = array ? array->type : 0; | |
887c31a3 JO |
1905 | if (type_id && id) |
1906 | *type_id = id; | |
7e3617a7 MKL |
1907 | |
1908 | return array_type ? : type; | |
1909 | } | |
1910 | ||
6298399b JO |
1911 | const struct btf_type * |
1912 | btf_resolve_size(const struct btf *btf, const struct btf_type *type, | |
1913 | u32 *type_size) | |
1914 | { | |
887c31a3 | 1915 | return __btf_resolve_size(btf, type, type_size, NULL, NULL, NULL, NULL); |
6298399b JO |
1916 | } |
1917 | ||
951bb646 AN |
1918 | static u32 btf_resolved_type_id(const struct btf *btf, u32 type_id) |
1919 | { | |
1920 | while (type_id < btf->start_id) | |
1921 | btf = btf->base_btf; | |
1922 | ||
1923 | return btf->resolved_ids[type_id - btf->start_id]; | |
1924 | } | |
1925 | ||
eb3f595d MKL |
1926 | /* The input param "type_id" must point to a needs_resolve type */ |
1927 | static const struct btf_type *btf_type_id_resolve(const struct btf *btf, | |
1928 | u32 *type_id) | |
1929 | { | |
951bb646 | 1930 | *type_id = btf_resolved_type_id(btf, *type_id); |
eb3f595d MKL |
1931 | return btf_type_by_id(btf, *type_id); |
1932 | } | |
1933 | ||
951bb646 AN |
1934 | static u32 btf_resolved_type_size(const struct btf *btf, u32 type_id) |
1935 | { | |
1936 | while (type_id < btf->start_id) | |
1937 | btf = btf->base_btf; | |
1938 | ||
1939 | return btf->resolved_sizes[type_id - btf->start_id]; | |
1940 | } | |
1941 | ||
eb3f595d MKL |
1942 | const struct btf_type *btf_type_id_size(const struct btf *btf, |
1943 | u32 *type_id, u32 *ret_size) | |
1944 | { | |
1945 | const struct btf_type *size_type; | |
1946 | u32 size_type_id = *type_id; | |
1947 | u32 size = 0; | |
1948 | ||
1949 | size_type = btf_type_by_id(btf, size_type_id); | |
b47a0bd2 | 1950 | if (btf_type_nosize_or_null(size_type)) |
eb3f595d MKL |
1951 | return NULL; |
1952 | ||
1953 | if (btf_type_has_size(size_type)) { | |
1954 | size = size_type->size; | |
1955 | } else if (btf_type_is_array(size_type)) { | |
951bb646 | 1956 | size = btf_resolved_type_size(btf, size_type_id); |
eb3f595d MKL |
1957 | } else if (btf_type_is_ptr(size_type)) { |
1958 | size = sizeof(void *); | |
1959 | } else { | |
1dc92851 DB |
1960 | if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) && |
1961 | !btf_type_is_var(size_type))) | |
eb3f595d MKL |
1962 | return NULL; |
1963 | ||
951bb646 | 1964 | size_type_id = btf_resolved_type_id(btf, size_type_id); |
eb3f595d | 1965 | size_type = btf_type_by_id(btf, size_type_id); |
b47a0bd2 | 1966 | if (btf_type_nosize_or_null(size_type)) |
eb3f595d | 1967 | return NULL; |
1acc5d5c AN |
1968 | else if (btf_type_has_size(size_type)) |
1969 | size = size_type->size; | |
1970 | else if (btf_type_is_array(size_type)) | |
951bb646 | 1971 | size = btf_resolved_type_size(btf, size_type_id); |
1acc5d5c AN |
1972 | else if (btf_type_is_ptr(size_type)) |
1973 | size = sizeof(void *); | |
1974 | else | |
1975 | return NULL; | |
eb3f595d MKL |
1976 | } |
1977 | ||
1978 | *type_id = size_type_id; | |
1979 | if (ret_size) | |
1980 | *ret_size = size; | |
1981 | ||
1982 | return size_type; | |
1983 | } | |
1984 | ||
179cde8c MKL |
1985 | static int btf_df_check_member(struct btf_verifier_env *env, |
1986 | const struct btf_type *struct_type, | |
1987 | const struct btf_member *member, | |
1988 | const struct btf_type *member_type) | |
1989 | { | |
1990 | btf_verifier_log_basic(env, struct_type, | |
1991 | "Unsupported check_member"); | |
1992 | return -EINVAL; | |
1993 | } | |
1994 | ||
9d5f9f70 YS |
1995 | static int btf_df_check_kflag_member(struct btf_verifier_env *env, |
1996 | const struct btf_type *struct_type, | |
1997 | const struct btf_member *member, | |
1998 | const struct btf_type *member_type) | |
1999 | { | |
2000 | btf_verifier_log_basic(env, struct_type, | |
2001 | "Unsupported check_kflag_member"); | |
2002 | return -EINVAL; | |
2003 | } | |
2004 | ||
b1828f0b | 2005 | /* Used for ptr, array struct/union and float type members. |
9d5f9f70 YS |
2006 | * int, enum and modifier types have their specific callback functions. |
2007 | */ | |
2008 | static int btf_generic_check_kflag_member(struct btf_verifier_env *env, | |
2009 | const struct btf_type *struct_type, | |
2010 | const struct btf_member *member, | |
2011 | const struct btf_type *member_type) | |
2012 | { | |
2013 | if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) { | |
2014 | btf_verifier_log_member(env, struct_type, member, | |
2015 | "Invalid member bitfield_size"); | |
2016 | return -EINVAL; | |
2017 | } | |
2018 | ||
2019 | /* bitfield size is 0, so member->offset represents bit offset only. | |
2020 | * It is safe to call non kflag check_member variants. | |
2021 | */ | |
2022 | return btf_type_ops(member_type)->check_member(env, struct_type, | |
2023 | member, | |
2024 | member_type); | |
2025 | } | |
2026 | ||
eb3f595d MKL |
2027 | static int btf_df_resolve(struct btf_verifier_env *env, |
2028 | const struct resolve_vertex *v) | |
2029 | { | |
2030 | btf_verifier_log_basic(env, v->t, "Unsupported resolve"); | |
2031 | return -EINVAL; | |
2032 | } | |
2033 | ||
31d0bc81 AM |
2034 | static void btf_df_show(const struct btf *btf, const struct btf_type *t, |
2035 | u32 type_id, void *data, u8 bits_offsets, | |
2036 | struct btf_show *show) | |
b00b8dae | 2037 | { |
31d0bc81 | 2038 | btf_show(show, "<unsupported kind:%u>", BTF_INFO_KIND(t->info)); |
b00b8dae MKL |
2039 | } |
2040 | ||
179cde8c MKL |
2041 | static int btf_int_check_member(struct btf_verifier_env *env, |
2042 | const struct btf_type *struct_type, | |
2043 | const struct btf_member *member, | |
2044 | const struct btf_type *member_type) | |
2045 | { | |
2046 | u32 int_data = btf_type_int(member_type); | |
2047 | u32 struct_bits_off = member->offset; | |
2048 | u32 struct_size = struct_type->size; | |
2049 | u32 nr_copy_bits; | |
2050 | u32 bytes_offset; | |
2051 | ||
2052 | if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) { | |
2053 | btf_verifier_log_member(env, struct_type, member, | |
2054 | "bits_offset exceeds U32_MAX"); | |
2055 | return -EINVAL; | |
2056 | } | |
2057 | ||
2058 | struct_bits_off += BTF_INT_OFFSET(int_data); | |
2059 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2060 | nr_copy_bits = BTF_INT_BITS(int_data) + | |
2061 | BITS_PER_BYTE_MASKED(struct_bits_off); | |
2062 | ||
b1e8818c | 2063 | if (nr_copy_bits > BITS_PER_U128) { |
179cde8c | 2064 | btf_verifier_log_member(env, struct_type, member, |
b1e8818c | 2065 | "nr_copy_bits exceeds 128"); |
179cde8c MKL |
2066 | return -EINVAL; |
2067 | } | |
2068 | ||
2069 | if (struct_size < bytes_offset || | |
2070 | struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { | |
2071 | btf_verifier_log_member(env, struct_type, member, | |
2072 | "Member exceeds struct_size"); | |
2073 | return -EINVAL; | |
2074 | } | |
2075 | ||
2076 | return 0; | |
2077 | } | |
2078 | ||
9d5f9f70 YS |
2079 | static int btf_int_check_kflag_member(struct btf_verifier_env *env, |
2080 | const struct btf_type *struct_type, | |
2081 | const struct btf_member *member, | |
2082 | const struct btf_type *member_type) | |
2083 | { | |
2084 | u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset; | |
2085 | u32 int_data = btf_type_int(member_type); | |
2086 | u32 struct_size = struct_type->size; | |
2087 | u32 nr_copy_bits; | |
2088 | ||
2089 | /* a regular int type is required for the kflag int member */ | |
2090 | if (!btf_type_int_is_regular(member_type)) { | |
2091 | btf_verifier_log_member(env, struct_type, member, | |
2092 | "Invalid member base type"); | |
2093 | return -EINVAL; | |
2094 | } | |
2095 | ||
2096 | /* check sanity of bitfield size */ | |
2097 | nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); | |
2098 | struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); | |
2099 | nr_int_data_bits = BTF_INT_BITS(int_data); | |
2100 | if (!nr_bits) { | |
2101 | /* Not a bitfield member, member offset must be at byte | |
2102 | * boundary. | |
2103 | */ | |
2104 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2105 | btf_verifier_log_member(env, struct_type, member, | |
2106 | "Invalid member offset"); | |
2107 | return -EINVAL; | |
2108 | } | |
2109 | ||
2110 | nr_bits = nr_int_data_bits; | |
2111 | } else if (nr_bits > nr_int_data_bits) { | |
2112 | btf_verifier_log_member(env, struct_type, member, | |
2113 | "Invalid member bitfield_size"); | |
2114 | return -EINVAL; | |
2115 | } | |
2116 | ||
2117 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2118 | nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off); | |
b1e8818c | 2119 | if (nr_copy_bits > BITS_PER_U128) { |
9d5f9f70 | 2120 | btf_verifier_log_member(env, struct_type, member, |
b1e8818c | 2121 | "nr_copy_bits exceeds 128"); |
9d5f9f70 YS |
2122 | return -EINVAL; |
2123 | } | |
2124 | ||
2125 | if (struct_size < bytes_offset || | |
2126 | struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { | |
2127 | btf_verifier_log_member(env, struct_type, member, | |
2128 | "Member exceeds struct_size"); | |
2129 | return -EINVAL; | |
2130 | } | |
2131 | ||
2132 | return 0; | |
2133 | } | |
2134 | ||
69b693f0 MKL |
2135 | static s32 btf_int_check_meta(struct btf_verifier_env *env, |
2136 | const struct btf_type *t, | |
2137 | u32 meta_left) | |
2138 | { | |
2139 | u32 int_data, nr_bits, meta_needed = sizeof(int_data); | |
2140 | u16 encoding; | |
2141 | ||
2142 | if (meta_left < meta_needed) { | |
2143 | btf_verifier_log_basic(env, t, | |
2144 | "meta_left:%u meta_needed:%u", | |
2145 | meta_left, meta_needed); | |
2146 | return -EINVAL; | |
2147 | } | |
2148 | ||
2149 | if (btf_type_vlen(t)) { | |
2150 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2151 | return -EINVAL; | |
2152 | } | |
2153 | ||
9d5f9f70 YS |
2154 | if (btf_type_kflag(t)) { |
2155 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2156 | return -EINVAL; | |
2157 | } | |
2158 | ||
69b693f0 | 2159 | int_data = btf_type_int(t); |
aea2f7b8 MKL |
2160 | if (int_data & ~BTF_INT_MASK) { |
2161 | btf_verifier_log_basic(env, t, "Invalid int_data:%x", | |
2162 | int_data); | |
2163 | return -EINVAL; | |
2164 | } | |
2165 | ||
69b693f0 MKL |
2166 | nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data); |
2167 | ||
b1e8818c | 2168 | if (nr_bits > BITS_PER_U128) { |
69b693f0 | 2169 | btf_verifier_log_type(env, t, "nr_bits exceeds %zu", |
b1e8818c | 2170 | BITS_PER_U128); |
69b693f0 MKL |
2171 | return -EINVAL; |
2172 | } | |
2173 | ||
2174 | if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) { | |
2175 | btf_verifier_log_type(env, t, "nr_bits exceeds type_size"); | |
2176 | return -EINVAL; | |
2177 | } | |
2178 | ||
aea2f7b8 MKL |
2179 | /* |
2180 | * Only one of the encoding bits is allowed and it | |
2181 | * should be sufficient for the pretty print purpose (i.e. decoding). | |
2182 | * Multiple bits can be allowed later if it is found | |
2183 | * to be insufficient. | |
2184 | */ | |
69b693f0 MKL |
2185 | encoding = BTF_INT_ENCODING(int_data); |
2186 | if (encoding && | |
2187 | encoding != BTF_INT_SIGNED && | |
2188 | encoding != BTF_INT_CHAR && | |
aea2f7b8 | 2189 | encoding != BTF_INT_BOOL) { |
69b693f0 MKL |
2190 | btf_verifier_log_type(env, t, "Unsupported encoding"); |
2191 | return -ENOTSUPP; | |
2192 | } | |
2193 | ||
2194 | btf_verifier_log_type(env, t, NULL); | |
2195 | ||
2196 | return meta_needed; | |
2197 | } | |
2198 | ||
2199 | static void btf_int_log(struct btf_verifier_env *env, | |
2200 | const struct btf_type *t) | |
2201 | { | |
2202 | int int_data = btf_type_int(t); | |
2203 | ||
2204 | btf_verifier_log(env, | |
2205 | "size=%u bits_offset=%u nr_bits=%u encoding=%s", | |
2206 | t->size, BTF_INT_OFFSET(int_data), | |
2207 | BTF_INT_BITS(int_data), | |
2208 | btf_int_encoding_str(BTF_INT_ENCODING(int_data))); | |
2209 | } | |
2210 | ||
31d0bc81 | 2211 | static void btf_int128_print(struct btf_show *show, void *data) |
b1e8818c YS |
2212 | { |
2213 | /* data points to a __int128 number. | |
2214 | * Suppose | |
2215 | * int128_num = *(__int128 *)data; | |
2216 | * The below formulas shows what upper_num and lower_num represents: | |
2217 | * upper_num = int128_num >> 64; | |
2218 | * lower_num = int128_num & 0xffffffffFFFFFFFFULL; | |
2219 | */ | |
2220 | u64 upper_num, lower_num; | |
2221 | ||
2222 | #ifdef __BIG_ENDIAN_BITFIELD | |
2223 | upper_num = *(u64 *)data; | |
2224 | lower_num = *(u64 *)(data + 8); | |
2225 | #else | |
2226 | upper_num = *(u64 *)(data + 8); | |
2227 | lower_num = *(u64 *)data; | |
2228 | #endif | |
2229 | if (upper_num == 0) | |
31d0bc81 | 2230 | btf_show_type_value(show, "0x%llx", lower_num); |
b1e8818c | 2231 | else |
31d0bc81 AM |
2232 | btf_show_type_values(show, "0x%llx%016llx", upper_num, |
2233 | lower_num); | |
b1e8818c YS |
2234 | } |
2235 | ||
2236 | static void btf_int128_shift(u64 *print_num, u16 left_shift_bits, | |
2237 | u16 right_shift_bits) | |
2238 | { | |
2239 | u64 upper_num, lower_num; | |
2240 | ||
2241 | #ifdef __BIG_ENDIAN_BITFIELD | |
2242 | upper_num = print_num[0]; | |
2243 | lower_num = print_num[1]; | |
2244 | #else | |
2245 | upper_num = print_num[1]; | |
2246 | lower_num = print_num[0]; | |
2247 | #endif | |
2248 | ||
2249 | /* shake out un-needed bits by shift/or operations */ | |
2250 | if (left_shift_bits >= 64) { | |
2251 | upper_num = lower_num << (left_shift_bits - 64); | |
2252 | lower_num = 0; | |
2253 | } else { | |
2254 | upper_num = (upper_num << left_shift_bits) | | |
2255 | (lower_num >> (64 - left_shift_bits)); | |
2256 | lower_num = lower_num << left_shift_bits; | |
2257 | } | |
2258 | ||
2259 | if (right_shift_bits >= 64) { | |
2260 | lower_num = upper_num >> (right_shift_bits - 64); | |
2261 | upper_num = 0; | |
2262 | } else { | |
2263 | lower_num = (lower_num >> right_shift_bits) | | |
2264 | (upper_num << (64 - right_shift_bits)); | |
2265 | upper_num = upper_num >> right_shift_bits; | |
2266 | } | |
2267 | ||
2268 | #ifdef __BIG_ENDIAN_BITFIELD | |
2269 | print_num[0] = upper_num; | |
2270 | print_num[1] = lower_num; | |
2271 | #else | |
2272 | print_num[0] = lower_num; | |
2273 | print_num[1] = upper_num; | |
2274 | #endif | |
2275 | } | |
2276 | ||
31d0bc81 AM |
2277 | static void btf_bitfield_show(void *data, u8 bits_offset, |
2278 | u8 nr_bits, struct btf_show *show) | |
b00b8dae | 2279 | { |
b65f370d | 2280 | u16 left_shift_bits, right_shift_bits; |
36fc3c8c MKL |
2281 | u8 nr_copy_bytes; |
2282 | u8 nr_copy_bits; | |
b1e8818c | 2283 | u64 print_num[2] = {}; |
b00b8dae | 2284 | |
b00b8dae MKL |
2285 | nr_copy_bits = nr_bits + bits_offset; |
2286 | nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits); | |
2287 | ||
b1e8818c | 2288 | memcpy(print_num, data, nr_copy_bytes); |
b00b8dae | 2289 | |
b65f370d OK |
2290 | #ifdef __BIG_ENDIAN_BITFIELD |
2291 | left_shift_bits = bits_offset; | |
2292 | #else | |
b1e8818c | 2293 | left_shift_bits = BITS_PER_U128 - nr_copy_bits; |
b65f370d | 2294 | #endif |
b1e8818c | 2295 | right_shift_bits = BITS_PER_U128 - nr_bits; |
b00b8dae | 2296 | |
b1e8818c | 2297 | btf_int128_shift(print_num, left_shift_bits, right_shift_bits); |
31d0bc81 | 2298 | btf_int128_print(show, print_num); |
b00b8dae MKL |
2299 | } |
2300 | ||
9d5f9f70 | 2301 | |
31d0bc81 AM |
2302 | static void btf_int_bits_show(const struct btf *btf, |
2303 | const struct btf_type *t, | |
2304 | void *data, u8 bits_offset, | |
2305 | struct btf_show *show) | |
f97be3ab YS |
2306 | { |
2307 | u32 int_data = btf_type_int(t); | |
2308 | u8 nr_bits = BTF_INT_BITS(int_data); | |
2309 | u8 total_bits_offset; | |
2310 | ||
2311 | /* | |
2312 | * bits_offset is at most 7. | |
b1e8818c | 2313 | * BTF_INT_OFFSET() cannot exceed 128 bits. |
f97be3ab YS |
2314 | */ |
2315 | total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data); | |
17e3ac81 YS |
2316 | data += BITS_ROUNDDOWN_BYTES(total_bits_offset); |
2317 | bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset); | |
31d0bc81 | 2318 | btf_bitfield_show(data, bits_offset, nr_bits, show); |
f97be3ab YS |
2319 | } |
2320 | ||
31d0bc81 AM |
2321 | static void btf_int_show(const struct btf *btf, const struct btf_type *t, |
2322 | u32 type_id, void *data, u8 bits_offset, | |
2323 | struct btf_show *show) | |
b00b8dae MKL |
2324 | { |
2325 | u32 int_data = btf_type_int(t); | |
2326 | u8 encoding = BTF_INT_ENCODING(int_data); | |
2327 | bool sign = encoding & BTF_INT_SIGNED; | |
36fc3c8c | 2328 | u8 nr_bits = BTF_INT_BITS(int_data); |
31d0bc81 AM |
2329 | void *safe_data; |
2330 | ||
2331 | safe_data = btf_show_start_type(show, t, type_id, data); | |
2332 | if (!safe_data) | |
2333 | return; | |
b00b8dae MKL |
2334 | |
2335 | if (bits_offset || BTF_INT_OFFSET(int_data) || | |
2336 | BITS_PER_BYTE_MASKED(nr_bits)) { | |
31d0bc81 AM |
2337 | btf_int_bits_show(btf, t, safe_data, bits_offset, show); |
2338 | goto out; | |
b00b8dae MKL |
2339 | } |
2340 | ||
2341 | switch (nr_bits) { | |
b1e8818c | 2342 | case 128: |
31d0bc81 | 2343 | btf_int128_print(show, safe_data); |
b1e8818c | 2344 | break; |
b00b8dae MKL |
2345 | case 64: |
2346 | if (sign) | |
31d0bc81 | 2347 | btf_show_type_value(show, "%lld", *(s64 *)safe_data); |
b00b8dae | 2348 | else |
31d0bc81 | 2349 | btf_show_type_value(show, "%llu", *(u64 *)safe_data); |
b00b8dae MKL |
2350 | break; |
2351 | case 32: | |
2352 | if (sign) | |
31d0bc81 | 2353 | btf_show_type_value(show, "%d", *(s32 *)safe_data); |
b00b8dae | 2354 | else |
31d0bc81 | 2355 | btf_show_type_value(show, "%u", *(u32 *)safe_data); |
b00b8dae MKL |
2356 | break; |
2357 | case 16: | |
2358 | if (sign) | |
31d0bc81 | 2359 | btf_show_type_value(show, "%d", *(s16 *)safe_data); |
b00b8dae | 2360 | else |
31d0bc81 | 2361 | btf_show_type_value(show, "%u", *(u16 *)safe_data); |
b00b8dae MKL |
2362 | break; |
2363 | case 8: | |
31d0bc81 AM |
2364 | if (show->state.array_encoding == BTF_INT_CHAR) { |
2365 | /* check for null terminator */ | |
2366 | if (show->state.array_terminated) | |
2367 | break; | |
2368 | if (*(char *)data == '\0') { | |
2369 | show->state.array_terminated = 1; | |
2370 | break; | |
2371 | } | |
2372 | if (isprint(*(char *)data)) { | |
2373 | btf_show_type_value(show, "'%c'", | |
2374 | *(char *)safe_data); | |
2375 | break; | |
2376 | } | |
2377 | } | |
b00b8dae | 2378 | if (sign) |
31d0bc81 | 2379 | btf_show_type_value(show, "%d", *(s8 *)safe_data); |
b00b8dae | 2380 | else |
31d0bc81 | 2381 | btf_show_type_value(show, "%u", *(u8 *)safe_data); |
b00b8dae MKL |
2382 | break; |
2383 | default: | |
31d0bc81 AM |
2384 | btf_int_bits_show(btf, t, safe_data, bits_offset, show); |
2385 | break; | |
b00b8dae | 2386 | } |
31d0bc81 AM |
2387 | out: |
2388 | btf_show_end_type(show); | |
b00b8dae MKL |
2389 | } |
2390 | ||
69b693f0 MKL |
2391 | static const struct btf_kind_operations int_ops = { |
2392 | .check_meta = btf_int_check_meta, | |
eb3f595d | 2393 | .resolve = btf_df_resolve, |
179cde8c | 2394 | .check_member = btf_int_check_member, |
9d5f9f70 | 2395 | .check_kflag_member = btf_int_check_kflag_member, |
69b693f0 | 2396 | .log_details = btf_int_log, |
31d0bc81 | 2397 | .show = btf_int_show, |
69b693f0 MKL |
2398 | }; |
2399 | ||
179cde8c MKL |
2400 | static int btf_modifier_check_member(struct btf_verifier_env *env, |
2401 | const struct btf_type *struct_type, | |
2402 | const struct btf_member *member, | |
2403 | const struct btf_type *member_type) | |
2404 | { | |
2405 | const struct btf_type *resolved_type; | |
2406 | u32 resolved_type_id = member->type; | |
2407 | struct btf_member resolved_member; | |
2408 | struct btf *btf = env->btf; | |
2409 | ||
2410 | resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); | |
2411 | if (!resolved_type) { | |
2412 | btf_verifier_log_member(env, struct_type, member, | |
2413 | "Invalid member"); | |
2414 | return -EINVAL; | |
2415 | } | |
2416 | ||
2417 | resolved_member = *member; | |
2418 | resolved_member.type = resolved_type_id; | |
2419 | ||
2420 | return btf_type_ops(resolved_type)->check_member(env, struct_type, | |
2421 | &resolved_member, | |
2422 | resolved_type); | |
2423 | } | |
2424 | ||
9d5f9f70 YS |
2425 | static int btf_modifier_check_kflag_member(struct btf_verifier_env *env, |
2426 | const struct btf_type *struct_type, | |
2427 | const struct btf_member *member, | |
2428 | const struct btf_type *member_type) | |
2429 | { | |
2430 | const struct btf_type *resolved_type; | |
2431 | u32 resolved_type_id = member->type; | |
2432 | struct btf_member resolved_member; | |
2433 | struct btf *btf = env->btf; | |
2434 | ||
2435 | resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); | |
2436 | if (!resolved_type) { | |
2437 | btf_verifier_log_member(env, struct_type, member, | |
2438 | "Invalid member"); | |
2439 | return -EINVAL; | |
2440 | } | |
2441 | ||
2442 | resolved_member = *member; | |
2443 | resolved_member.type = resolved_type_id; | |
2444 | ||
2445 | return btf_type_ops(resolved_type)->check_kflag_member(env, struct_type, | |
2446 | &resolved_member, | |
2447 | resolved_type); | |
2448 | } | |
2449 | ||
179cde8c MKL |
2450 | static int btf_ptr_check_member(struct btf_verifier_env *env, |
2451 | const struct btf_type *struct_type, | |
2452 | const struct btf_member *member, | |
2453 | const struct btf_type *member_type) | |
2454 | { | |
2455 | u32 struct_size, struct_bits_off, bytes_offset; | |
2456 | ||
2457 | struct_size = struct_type->size; | |
2458 | struct_bits_off = member->offset; | |
2459 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2460 | ||
2461 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2462 | btf_verifier_log_member(env, struct_type, member, | |
2463 | "Member is not byte aligned"); | |
2464 | return -EINVAL; | |
2465 | } | |
2466 | ||
2467 | if (struct_size - bytes_offset < sizeof(void *)) { | |
2468 | btf_verifier_log_member(env, struct_type, member, | |
2469 | "Member exceeds struct_size"); | |
2470 | return -EINVAL; | |
2471 | } | |
2472 | ||
2473 | return 0; | |
2474 | } | |
2475 | ||
69b693f0 MKL |
2476 | static int btf_ref_type_check_meta(struct btf_verifier_env *env, |
2477 | const struct btf_type *t, | |
2478 | u32 meta_left) | |
2479 | { | |
8c42d2fa YS |
2480 | const char *value; |
2481 | ||
69b693f0 MKL |
2482 | if (btf_type_vlen(t)) { |
2483 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2484 | return -EINVAL; | |
2485 | } | |
2486 | ||
9d5f9f70 YS |
2487 | if (btf_type_kflag(t)) { |
2488 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2489 | return -EINVAL; | |
2490 | } | |
2491 | ||
aea2f7b8 | 2492 | if (!BTF_TYPE_ID_VALID(t->type)) { |
69b693f0 MKL |
2493 | btf_verifier_log_type(env, t, "Invalid type_id"); |
2494 | return -EINVAL; | |
2495 | } | |
2496 | ||
8c42d2fa | 2497 | /* typedef/type_tag type must have a valid name, and other ref types, |
eb04bbb6 YS |
2498 | * volatile, const, restrict, should have a null name. |
2499 | */ | |
2500 | if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) { | |
2501 | if (!t->name_off || | |
2502 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
2503 | btf_verifier_log_type(env, t, "Invalid name"); | |
2504 | return -EINVAL; | |
2505 | } | |
8c42d2fa YS |
2506 | } else if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPE_TAG) { |
2507 | value = btf_name_by_offset(env->btf, t->name_off); | |
2508 | if (!value || !value[0]) { | |
2509 | btf_verifier_log_type(env, t, "Invalid name"); | |
2510 | return -EINVAL; | |
2511 | } | |
eb04bbb6 YS |
2512 | } else { |
2513 | if (t->name_off) { | |
2514 | btf_verifier_log_type(env, t, "Invalid name"); | |
2515 | return -EINVAL; | |
2516 | } | |
2517 | } | |
2518 | ||
69b693f0 MKL |
2519 | btf_verifier_log_type(env, t, NULL); |
2520 | ||
2521 | return 0; | |
2522 | } | |
2523 | ||
eb3f595d MKL |
2524 | static int btf_modifier_resolve(struct btf_verifier_env *env, |
2525 | const struct resolve_vertex *v) | |
2526 | { | |
2527 | const struct btf_type *t = v->t; | |
2528 | const struct btf_type *next_type; | |
2529 | u32 next_type_id = t->type; | |
2530 | struct btf *btf = env->btf; | |
eb3f595d MKL |
2531 | |
2532 | next_type = btf_type_by_id(btf, next_type_id); | |
1dc92851 | 2533 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
eb3f595d MKL |
2534 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2535 | return -EINVAL; | |
2536 | } | |
2537 | ||
eb3f595d MKL |
2538 | if (!env_type_is_resolve_sink(env, next_type) && |
2539 | !env_type_is_resolved(env, next_type_id)) | |
2540 | return env_stack_push(env, next_type, next_type_id); | |
2541 | ||
2542 | /* Figure out the resolved next_type_id with size. | |
2543 | * They will be stored in the current modifier's | |
2544 | * resolved_ids and resolved_sizes such that it can | |
2545 | * save us a few type-following when we use it later (e.g. in | |
2546 | * pretty print). | |
2547 | */ | |
1acc5d5c | 2548 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
2667a262 MKL |
2549 | if (env_type_is_resolved(env, next_type_id)) |
2550 | next_type = btf_type_id_resolve(btf, &next_type_id); | |
2551 | ||
2552 | /* "typedef void new_void", "const void"...etc */ | |
2553 | if (!btf_type_is_void(next_type) && | |
81f5c6f5 YS |
2554 | !btf_type_is_fwd(next_type) && |
2555 | !btf_type_is_func_proto(next_type)) { | |
2667a262 MKL |
2556 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2557 | return -EINVAL; | |
2558 | } | |
eb3f595d MKL |
2559 | } |
2560 | ||
1acc5d5c | 2561 | env_stack_pop_resolved(env, next_type_id, 0); |
eb3f595d MKL |
2562 | |
2563 | return 0; | |
2564 | } | |
2565 | ||
1dc92851 DB |
2566 | static int btf_var_resolve(struct btf_verifier_env *env, |
2567 | const struct resolve_vertex *v) | |
2568 | { | |
2569 | const struct btf_type *next_type; | |
2570 | const struct btf_type *t = v->t; | |
2571 | u32 next_type_id = t->type; | |
2572 | struct btf *btf = env->btf; | |
1dc92851 DB |
2573 | |
2574 | next_type = btf_type_by_id(btf, next_type_id); | |
2575 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { | |
2576 | btf_verifier_log_type(env, v->t, "Invalid type_id"); | |
2577 | return -EINVAL; | |
2578 | } | |
2579 | ||
2580 | if (!env_type_is_resolve_sink(env, next_type) && | |
2581 | !env_type_is_resolved(env, next_type_id)) | |
2582 | return env_stack_push(env, next_type, next_type_id); | |
2583 | ||
2584 | if (btf_type_is_modifier(next_type)) { | |
2585 | const struct btf_type *resolved_type; | |
2586 | u32 resolved_type_id; | |
2587 | ||
2588 | resolved_type_id = next_type_id; | |
2589 | resolved_type = btf_type_id_resolve(btf, &resolved_type_id); | |
2590 | ||
2591 | if (btf_type_is_ptr(resolved_type) && | |
2592 | !env_type_is_resolve_sink(env, resolved_type) && | |
2593 | !env_type_is_resolved(env, resolved_type_id)) | |
2594 | return env_stack_push(env, resolved_type, | |
2595 | resolved_type_id); | |
2596 | } | |
2597 | ||
2598 | /* We must resolve to something concrete at this point, no | |
2599 | * forward types or similar that would resolve to size of | |
2600 | * zero is allowed. | |
2601 | */ | |
1acc5d5c | 2602 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
1dc92851 DB |
2603 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2604 | return -EINVAL; | |
2605 | } | |
2606 | ||
1acc5d5c | 2607 | env_stack_pop_resolved(env, next_type_id, 0); |
1dc92851 DB |
2608 | |
2609 | return 0; | |
2610 | } | |
2611 | ||
eb3f595d MKL |
2612 | static int btf_ptr_resolve(struct btf_verifier_env *env, |
2613 | const struct resolve_vertex *v) | |
2614 | { | |
2615 | const struct btf_type *next_type; | |
2616 | const struct btf_type *t = v->t; | |
2617 | u32 next_type_id = t->type; | |
2618 | struct btf *btf = env->btf; | |
eb3f595d MKL |
2619 | |
2620 | next_type = btf_type_by_id(btf, next_type_id); | |
1dc92851 | 2621 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
eb3f595d MKL |
2622 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2623 | return -EINVAL; | |
2624 | } | |
2625 | ||
eb3f595d MKL |
2626 | if (!env_type_is_resolve_sink(env, next_type) && |
2627 | !env_type_is_resolved(env, next_type_id)) | |
2628 | return env_stack_push(env, next_type, next_type_id); | |
2629 | ||
2630 | /* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY, | |
2631 | * the modifier may have stopped resolving when it was resolved | |
2632 | * to a ptr (last-resolved-ptr). | |
2633 | * | |
2634 | * We now need to continue from the last-resolved-ptr to | |
2635 | * ensure the last-resolved-ptr will not referring back to | |
c561d110 | 2636 | * the current ptr (t). |
eb3f595d MKL |
2637 | */ |
2638 | if (btf_type_is_modifier(next_type)) { | |
2639 | const struct btf_type *resolved_type; | |
2640 | u32 resolved_type_id; | |
2641 | ||
2642 | resolved_type_id = next_type_id; | |
2643 | resolved_type = btf_type_id_resolve(btf, &resolved_type_id); | |
2644 | ||
2645 | if (btf_type_is_ptr(resolved_type) && | |
2646 | !env_type_is_resolve_sink(env, resolved_type) && | |
2647 | !env_type_is_resolved(env, resolved_type_id)) | |
2648 | return env_stack_push(env, resolved_type, | |
2649 | resolved_type_id); | |
2650 | } | |
2651 | ||
2667a262 MKL |
2652 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
2653 | if (env_type_is_resolved(env, next_type_id)) | |
2654 | next_type = btf_type_id_resolve(btf, &next_type_id); | |
2655 | ||
2656 | if (!btf_type_is_void(next_type) && | |
2657 | !btf_type_is_fwd(next_type) && | |
2658 | !btf_type_is_func_proto(next_type)) { | |
2659 | btf_verifier_log_type(env, v->t, "Invalid type_id"); | |
2660 | return -EINVAL; | |
2661 | } | |
eb3f595d MKL |
2662 | } |
2663 | ||
eb3f595d MKL |
2664 | env_stack_pop_resolved(env, next_type_id, 0); |
2665 | ||
2666 | return 0; | |
2667 | } | |
2668 | ||
31d0bc81 AM |
2669 | static void btf_modifier_show(const struct btf *btf, |
2670 | const struct btf_type *t, | |
2671 | u32 type_id, void *data, | |
2672 | u8 bits_offset, struct btf_show *show) | |
b00b8dae | 2673 | { |
85d33df3 MKL |
2674 | if (btf->resolved_ids) |
2675 | t = btf_type_id_resolve(btf, &type_id); | |
2676 | else | |
2677 | t = btf_type_skip_modifiers(btf, type_id, NULL); | |
b00b8dae | 2678 | |
31d0bc81 | 2679 | btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show); |
b00b8dae MKL |
2680 | } |
2681 | ||
31d0bc81 AM |
2682 | static void btf_var_show(const struct btf *btf, const struct btf_type *t, |
2683 | u32 type_id, void *data, u8 bits_offset, | |
2684 | struct btf_show *show) | |
1dc92851 DB |
2685 | { |
2686 | t = btf_type_id_resolve(btf, &type_id); | |
2687 | ||
31d0bc81 | 2688 | btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show); |
1dc92851 DB |
2689 | } |
2690 | ||
31d0bc81 AM |
2691 | static void btf_ptr_show(const struct btf *btf, const struct btf_type *t, |
2692 | u32 type_id, void *data, u8 bits_offset, | |
2693 | struct btf_show *show) | |
b00b8dae | 2694 | { |
31d0bc81 AM |
2695 | void *safe_data; |
2696 | ||
2697 | safe_data = btf_show_start_type(show, t, type_id, data); | |
2698 | if (!safe_data) | |
2699 | return; | |
2700 | ||
2701 | /* It is a hashed value unless BTF_SHOW_PTR_RAW is specified */ | |
2702 | if (show->flags & BTF_SHOW_PTR_RAW) | |
2703 | btf_show_type_value(show, "0x%px", *(void **)safe_data); | |
2704 | else | |
2705 | btf_show_type_value(show, "0x%p", *(void **)safe_data); | |
2706 | btf_show_end_type(show); | |
b00b8dae MKL |
2707 | } |
2708 | ||
69b693f0 MKL |
2709 | static void btf_ref_type_log(struct btf_verifier_env *env, |
2710 | const struct btf_type *t) | |
2711 | { | |
2712 | btf_verifier_log(env, "type_id=%u", t->type); | |
2713 | } | |
2714 | ||
2715 | static struct btf_kind_operations modifier_ops = { | |
2716 | .check_meta = btf_ref_type_check_meta, | |
eb3f595d | 2717 | .resolve = btf_modifier_resolve, |
179cde8c | 2718 | .check_member = btf_modifier_check_member, |
9d5f9f70 | 2719 | .check_kflag_member = btf_modifier_check_kflag_member, |
69b693f0 | 2720 | .log_details = btf_ref_type_log, |
31d0bc81 | 2721 | .show = btf_modifier_show, |
69b693f0 MKL |
2722 | }; |
2723 | ||
2724 | static struct btf_kind_operations ptr_ops = { | |
2725 | .check_meta = btf_ref_type_check_meta, | |
eb3f595d | 2726 | .resolve = btf_ptr_resolve, |
179cde8c | 2727 | .check_member = btf_ptr_check_member, |
9d5f9f70 | 2728 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 2729 | .log_details = btf_ref_type_log, |
31d0bc81 | 2730 | .show = btf_ptr_show, |
69b693f0 MKL |
2731 | }; |
2732 | ||
8175383f MKL |
2733 | static s32 btf_fwd_check_meta(struct btf_verifier_env *env, |
2734 | const struct btf_type *t, | |
2735 | u32 meta_left) | |
2736 | { | |
2737 | if (btf_type_vlen(t)) { | |
2738 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2739 | return -EINVAL; | |
2740 | } | |
2741 | ||
2742 | if (t->type) { | |
2743 | btf_verifier_log_type(env, t, "type != 0"); | |
2744 | return -EINVAL; | |
2745 | } | |
2746 | ||
eb04bbb6 YS |
2747 | /* fwd type must have a valid name */ |
2748 | if (!t->name_off || | |
2749 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
2750 | btf_verifier_log_type(env, t, "Invalid name"); | |
2751 | return -EINVAL; | |
2752 | } | |
2753 | ||
8175383f MKL |
2754 | btf_verifier_log_type(env, t, NULL); |
2755 | ||
2756 | return 0; | |
2757 | } | |
2758 | ||
76c43ae8 YS |
2759 | static void btf_fwd_type_log(struct btf_verifier_env *env, |
2760 | const struct btf_type *t) | |
2761 | { | |
2762 | btf_verifier_log(env, "%s", btf_type_kflag(t) ? "union" : "struct"); | |
2763 | } | |
2764 | ||
69b693f0 | 2765 | static struct btf_kind_operations fwd_ops = { |
8175383f | 2766 | .check_meta = btf_fwd_check_meta, |
eb3f595d | 2767 | .resolve = btf_df_resolve, |
179cde8c | 2768 | .check_member = btf_df_check_member, |
9d5f9f70 | 2769 | .check_kflag_member = btf_df_check_kflag_member, |
76c43ae8 | 2770 | .log_details = btf_fwd_type_log, |
31d0bc81 | 2771 | .show = btf_df_show, |
69b693f0 MKL |
2772 | }; |
2773 | ||
179cde8c MKL |
2774 | static int btf_array_check_member(struct btf_verifier_env *env, |
2775 | const struct btf_type *struct_type, | |
2776 | const struct btf_member *member, | |
2777 | const struct btf_type *member_type) | |
2778 | { | |
2779 | u32 struct_bits_off = member->offset; | |
2780 | u32 struct_size, bytes_offset; | |
2781 | u32 array_type_id, array_size; | |
2782 | struct btf *btf = env->btf; | |
2783 | ||
2784 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2785 | btf_verifier_log_member(env, struct_type, member, | |
2786 | "Member is not byte aligned"); | |
2787 | return -EINVAL; | |
2788 | } | |
2789 | ||
2790 | array_type_id = member->type; | |
2791 | btf_type_id_size(btf, &array_type_id, &array_size); | |
2792 | struct_size = struct_type->size; | |
2793 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2794 | if (struct_size - bytes_offset < array_size) { | |
2795 | btf_verifier_log_member(env, struct_type, member, | |
2796 | "Member exceeds struct_size"); | |
2797 | return -EINVAL; | |
2798 | } | |
2799 | ||
2800 | return 0; | |
2801 | } | |
2802 | ||
69b693f0 MKL |
2803 | static s32 btf_array_check_meta(struct btf_verifier_env *env, |
2804 | const struct btf_type *t, | |
2805 | u32 meta_left) | |
2806 | { | |
2807 | const struct btf_array *array = btf_type_array(t); | |
2808 | u32 meta_needed = sizeof(*array); | |
2809 | ||
2810 | if (meta_left < meta_needed) { | |
2811 | btf_verifier_log_basic(env, t, | |
2812 | "meta_left:%u meta_needed:%u", | |
2813 | meta_left, meta_needed); | |
2814 | return -EINVAL; | |
2815 | } | |
2816 | ||
eb04bbb6 YS |
2817 | /* array type should not have a name */ |
2818 | if (t->name_off) { | |
2819 | btf_verifier_log_type(env, t, "Invalid name"); | |
2820 | return -EINVAL; | |
2821 | } | |
2822 | ||
69b693f0 MKL |
2823 | if (btf_type_vlen(t)) { |
2824 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2825 | return -EINVAL; | |
2826 | } | |
2827 | ||
9d5f9f70 YS |
2828 | if (btf_type_kflag(t)) { |
2829 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2830 | return -EINVAL; | |
2831 | } | |
2832 | ||
b9308ae6 MKL |
2833 | if (t->size) { |
2834 | btf_verifier_log_type(env, t, "size != 0"); | |
2835 | return -EINVAL; | |
2836 | } | |
2837 | ||
4ef5f574 MKL |
2838 | /* Array elem type and index type cannot be in type void, |
2839 | * so !array->type and !array->index_type are not allowed. | |
69b693f0 | 2840 | */ |
aea2f7b8 | 2841 | if (!array->type || !BTF_TYPE_ID_VALID(array->type)) { |
4ef5f574 MKL |
2842 | btf_verifier_log_type(env, t, "Invalid elem"); |
2843 | return -EINVAL; | |
2844 | } | |
2845 | ||
aea2f7b8 | 2846 | if (!array->index_type || !BTF_TYPE_ID_VALID(array->index_type)) { |
4ef5f574 | 2847 | btf_verifier_log_type(env, t, "Invalid index"); |
69b693f0 MKL |
2848 | return -EINVAL; |
2849 | } | |
2850 | ||
2851 | btf_verifier_log_type(env, t, NULL); | |
2852 | ||
2853 | return meta_needed; | |
2854 | } | |
2855 | ||
eb3f595d MKL |
2856 | static int btf_array_resolve(struct btf_verifier_env *env, |
2857 | const struct resolve_vertex *v) | |
2858 | { | |
2859 | const struct btf_array *array = btf_type_array(v->t); | |
4ef5f574 MKL |
2860 | const struct btf_type *elem_type, *index_type; |
2861 | u32 elem_type_id, index_type_id; | |
eb3f595d MKL |
2862 | struct btf *btf = env->btf; |
2863 | u32 elem_size; | |
2864 | ||
4ef5f574 MKL |
2865 | /* Check array->index_type */ |
2866 | index_type_id = array->index_type; | |
2867 | index_type = btf_type_by_id(btf, index_type_id); | |
e4f07120 SF |
2868 | if (btf_type_nosize_or_null(index_type) || |
2869 | btf_type_is_resolve_source_only(index_type)) { | |
4ef5f574 MKL |
2870 | btf_verifier_log_type(env, v->t, "Invalid index"); |
2871 | return -EINVAL; | |
2872 | } | |
2873 | ||
2874 | if (!env_type_is_resolve_sink(env, index_type) && | |
2875 | !env_type_is_resolved(env, index_type_id)) | |
2876 | return env_stack_push(env, index_type, index_type_id); | |
2877 | ||
2878 | index_type = btf_type_id_size(btf, &index_type_id, NULL); | |
2879 | if (!index_type || !btf_type_is_int(index_type) || | |
2880 | !btf_type_int_is_regular(index_type)) { | |
2881 | btf_verifier_log_type(env, v->t, "Invalid index"); | |
2882 | return -EINVAL; | |
2883 | } | |
2884 | ||
2885 | /* Check array->type */ | |
2886 | elem_type_id = array->type; | |
eb3f595d | 2887 | elem_type = btf_type_by_id(btf, elem_type_id); |
e4f07120 SF |
2888 | if (btf_type_nosize_or_null(elem_type) || |
2889 | btf_type_is_resolve_source_only(elem_type)) { | |
eb3f595d MKL |
2890 | btf_verifier_log_type(env, v->t, |
2891 | "Invalid elem"); | |
2892 | return -EINVAL; | |
2893 | } | |
2894 | ||
2895 | if (!env_type_is_resolve_sink(env, elem_type) && | |
2896 | !env_type_is_resolved(env, elem_type_id)) | |
2897 | return env_stack_push(env, elem_type, elem_type_id); | |
2898 | ||
2899 | elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); | |
2900 | if (!elem_type) { | |
2901 | btf_verifier_log_type(env, v->t, "Invalid elem"); | |
2902 | return -EINVAL; | |
2903 | } | |
2904 | ||
4ef5f574 MKL |
2905 | if (btf_type_is_int(elem_type) && !btf_type_int_is_regular(elem_type)) { |
2906 | btf_verifier_log_type(env, v->t, "Invalid array of int"); | |
2907 | return -EINVAL; | |
eb3f595d MKL |
2908 | } |
2909 | ||
2910 | if (array->nelems && elem_size > U32_MAX / array->nelems) { | |
2911 | btf_verifier_log_type(env, v->t, | |
2912 | "Array size overflows U32_MAX"); | |
2913 | return -EINVAL; | |
2914 | } | |
2915 | ||
2916 | env_stack_pop_resolved(env, elem_type_id, elem_size * array->nelems); | |
2917 | ||
2918 | return 0; | |
2919 | } | |
2920 | ||
69b693f0 MKL |
2921 | static void btf_array_log(struct btf_verifier_env *env, |
2922 | const struct btf_type *t) | |
2923 | { | |
2924 | const struct btf_array *array = btf_type_array(t); | |
2925 | ||
2926 | btf_verifier_log(env, "type_id=%u index_type_id=%u nr_elems=%u", | |
2927 | array->type, array->index_type, array->nelems); | |
2928 | } | |
2929 | ||
31d0bc81 AM |
2930 | static void __btf_array_show(const struct btf *btf, const struct btf_type *t, |
2931 | u32 type_id, void *data, u8 bits_offset, | |
2932 | struct btf_show *show) | |
b00b8dae MKL |
2933 | { |
2934 | const struct btf_array *array = btf_type_array(t); | |
2935 | const struct btf_kind_operations *elem_ops; | |
2936 | const struct btf_type *elem_type; | |
31d0bc81 AM |
2937 | u32 i, elem_size = 0, elem_type_id; |
2938 | u16 encoding = 0; | |
b00b8dae MKL |
2939 | |
2940 | elem_type_id = array->type; | |
31d0bc81 AM |
2941 | elem_type = btf_type_skip_modifiers(btf, elem_type_id, NULL); |
2942 | if (elem_type && btf_type_has_size(elem_type)) | |
2943 | elem_size = elem_type->size; | |
2944 | ||
2945 | if (elem_type && btf_type_is_int(elem_type)) { | |
2946 | u32 int_type = btf_type_int(elem_type); | |
2947 | ||
2948 | encoding = BTF_INT_ENCODING(int_type); | |
2949 | ||
2950 | /* | |
2951 | * BTF_INT_CHAR encoding never seems to be set for | |
2952 | * char arrays, so if size is 1 and element is | |
2953 | * printable as a char, we'll do that. | |
2954 | */ | |
2955 | if (elem_size == 1) | |
2956 | encoding = BTF_INT_CHAR; | |
2957 | } | |
2958 | ||
2959 | if (!btf_show_start_array_type(show, t, type_id, encoding, data)) | |
2960 | return; | |
2961 | ||
2962 | if (!elem_type) | |
2963 | goto out; | |
b00b8dae | 2964 | elem_ops = btf_type_ops(elem_type); |
31d0bc81 | 2965 | |
b00b8dae | 2966 | for (i = 0; i < array->nelems; i++) { |
b00b8dae | 2967 | |
31d0bc81 AM |
2968 | btf_show_start_array_member(show); |
2969 | ||
2970 | elem_ops->show(btf, elem_type, elem_type_id, data, | |
2971 | bits_offset, show); | |
b00b8dae | 2972 | data += elem_size; |
31d0bc81 AM |
2973 | |
2974 | btf_show_end_array_member(show); | |
2975 | ||
2976 | if (show->state.array_terminated) | |
2977 | break; | |
b00b8dae | 2978 | } |
31d0bc81 AM |
2979 | out: |
2980 | btf_show_end_array_type(show); | |
2981 | } | |
2982 | ||
2983 | static void btf_array_show(const struct btf *btf, const struct btf_type *t, | |
2984 | u32 type_id, void *data, u8 bits_offset, | |
2985 | struct btf_show *show) | |
2986 | { | |
2987 | const struct btf_member *m = show->state.member; | |
2988 | ||
2989 | /* | |
2990 | * First check if any members would be shown (are non-zero). | |
2991 | * See comments above "struct btf_show" definition for more | |
2992 | * details on how this works at a high-level. | |
2993 | */ | |
2994 | if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) { | |
2995 | if (!show->state.depth_check) { | |
2996 | show->state.depth_check = show->state.depth + 1; | |
2997 | show->state.depth_to_show = 0; | |
2998 | } | |
2999 | __btf_array_show(btf, t, type_id, data, bits_offset, show); | |
3000 | show->state.member = m; | |
3001 | ||
3002 | if (show->state.depth_check != show->state.depth + 1) | |
3003 | return; | |
3004 | show->state.depth_check = 0; | |
3005 | ||
3006 | if (show->state.depth_to_show <= show->state.depth) | |
3007 | return; | |
3008 | /* | |
3009 | * Reaching here indicates we have recursed and found | |
3010 | * non-zero array member(s). | |
3011 | */ | |
3012 | } | |
3013 | __btf_array_show(btf, t, type_id, data, bits_offset, show); | |
b00b8dae MKL |
3014 | } |
3015 | ||
69b693f0 MKL |
3016 | static struct btf_kind_operations array_ops = { |
3017 | .check_meta = btf_array_check_meta, | |
eb3f595d | 3018 | .resolve = btf_array_resolve, |
179cde8c | 3019 | .check_member = btf_array_check_member, |
9d5f9f70 | 3020 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 3021 | .log_details = btf_array_log, |
31d0bc81 | 3022 | .show = btf_array_show, |
69b693f0 MKL |
3023 | }; |
3024 | ||
179cde8c MKL |
3025 | static int btf_struct_check_member(struct btf_verifier_env *env, |
3026 | const struct btf_type *struct_type, | |
3027 | const struct btf_member *member, | |
3028 | const struct btf_type *member_type) | |
3029 | { | |
3030 | u32 struct_bits_off = member->offset; | |
3031 | u32 struct_size, bytes_offset; | |
3032 | ||
3033 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
3034 | btf_verifier_log_member(env, struct_type, member, | |
3035 | "Member is not byte aligned"); | |
3036 | return -EINVAL; | |
3037 | } | |
3038 | ||
3039 | struct_size = struct_type->size; | |
3040 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
3041 | if (struct_size - bytes_offset < member_type->size) { | |
3042 | btf_verifier_log_member(env, struct_type, member, | |
3043 | "Member exceeds struct_size"); | |
3044 | return -EINVAL; | |
3045 | } | |
3046 | ||
3047 | return 0; | |
3048 | } | |
3049 | ||
69b693f0 MKL |
3050 | static s32 btf_struct_check_meta(struct btf_verifier_env *env, |
3051 | const struct btf_type *t, | |
3052 | u32 meta_left) | |
3053 | { | |
3054 | bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION; | |
3055 | const struct btf_member *member; | |
6283fa38 | 3056 | u32 meta_needed, last_offset; |
69b693f0 MKL |
3057 | struct btf *btf = env->btf; |
3058 | u32 struct_size = t->size; | |
9d5f9f70 | 3059 | u32 offset; |
69b693f0 MKL |
3060 | u16 i; |
3061 | ||
3062 | meta_needed = btf_type_vlen(t) * sizeof(*member); | |
3063 | if (meta_left < meta_needed) { | |
3064 | btf_verifier_log_basic(env, t, | |
3065 | "meta_left:%u meta_needed:%u", | |
3066 | meta_left, meta_needed); | |
3067 | return -EINVAL; | |
3068 | } | |
3069 | ||
eb04bbb6 YS |
3070 | /* struct type either no name or a valid one */ |
3071 | if (t->name_off && | |
3072 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
3073 | btf_verifier_log_type(env, t, "Invalid name"); | |
3074 | return -EINVAL; | |
3075 | } | |
3076 | ||
69b693f0 MKL |
3077 | btf_verifier_log_type(env, t, NULL); |
3078 | ||
6283fa38 | 3079 | last_offset = 0; |
69b693f0 | 3080 | for_each_member(i, t, member) { |
fbcf93eb | 3081 | if (!btf_name_offset_valid(btf, member->name_off)) { |
69b693f0 MKL |
3082 | btf_verifier_log_member(env, t, member, |
3083 | "Invalid member name_offset:%u", | |
fbcf93eb | 3084 | member->name_off); |
69b693f0 MKL |
3085 | return -EINVAL; |
3086 | } | |
3087 | ||
eb04bbb6 YS |
3088 | /* struct member either no name or a valid one */ |
3089 | if (member->name_off && | |
3090 | !btf_name_valid_identifier(btf, member->name_off)) { | |
3091 | btf_verifier_log_member(env, t, member, "Invalid name"); | |
3092 | return -EINVAL; | |
3093 | } | |
69b693f0 | 3094 | /* A member cannot be in type void */ |
aea2f7b8 | 3095 | if (!member->type || !BTF_TYPE_ID_VALID(member->type)) { |
69b693f0 MKL |
3096 | btf_verifier_log_member(env, t, member, |
3097 | "Invalid type_id"); | |
3098 | return -EINVAL; | |
3099 | } | |
3100 | ||
8293eb99 | 3101 | offset = __btf_member_bit_offset(t, member); |
9d5f9f70 | 3102 | if (is_union && offset) { |
69b693f0 MKL |
3103 | btf_verifier_log_member(env, t, member, |
3104 | "Invalid member bits_offset"); | |
3105 | return -EINVAL; | |
3106 | } | |
3107 | ||
6283fa38 MKL |
3108 | /* |
3109 | * ">" instead of ">=" because the last member could be | |
3110 | * "char a[0];" | |
3111 | */ | |
9d5f9f70 | 3112 | if (last_offset > offset) { |
6283fa38 MKL |
3113 | btf_verifier_log_member(env, t, member, |
3114 | "Invalid member bits_offset"); | |
3115 | return -EINVAL; | |
3116 | } | |
3117 | ||
9d5f9f70 | 3118 | if (BITS_ROUNDUP_BYTES(offset) > struct_size) { |
69b693f0 | 3119 | btf_verifier_log_member(env, t, member, |
311fe1a8 | 3120 | "Member bits_offset exceeds its struct size"); |
69b693f0 MKL |
3121 | return -EINVAL; |
3122 | } | |
3123 | ||
3124 | btf_verifier_log_member(env, t, member, NULL); | |
9d5f9f70 | 3125 | last_offset = offset; |
69b693f0 MKL |
3126 | } |
3127 | ||
3128 | return meta_needed; | |
3129 | } | |
3130 | ||
eb3f595d MKL |
3131 | static int btf_struct_resolve(struct btf_verifier_env *env, |
3132 | const struct resolve_vertex *v) | |
3133 | { | |
3134 | const struct btf_member *member; | |
179cde8c | 3135 | int err; |
eb3f595d MKL |
3136 | u16 i; |
3137 | ||
3138 | /* Before continue resolving the next_member, | |
3139 | * ensure the last member is indeed resolved to a | |
3140 | * type with size info. | |
3141 | */ | |
3142 | if (v->next_member) { | |
179cde8c | 3143 | const struct btf_type *last_member_type; |
eb3f595d | 3144 | const struct btf_member *last_member; |
a37a3258 | 3145 | u32 last_member_type_id; |
eb3f595d MKL |
3146 | |
3147 | last_member = btf_type_member(v->t) + v->next_member - 1; | |
3148 | last_member_type_id = last_member->type; | |
3149 | if (WARN_ON_ONCE(!env_type_is_resolved(env, | |
3150 | last_member_type_id))) | |
3151 | return -EINVAL; | |
179cde8c MKL |
3152 | |
3153 | last_member_type = btf_type_by_id(env->btf, | |
3154 | last_member_type_id); | |
9d5f9f70 YS |
3155 | if (btf_type_kflag(v->t)) |
3156 | err = btf_type_ops(last_member_type)->check_kflag_member(env, v->t, | |
3157 | last_member, | |
3158 | last_member_type); | |
3159 | else | |
3160 | err = btf_type_ops(last_member_type)->check_member(env, v->t, | |
3161 | last_member, | |
3162 | last_member_type); | |
179cde8c MKL |
3163 | if (err) |
3164 | return err; | |
eb3f595d MKL |
3165 | } |
3166 | ||
3167 | for_each_member_from(i, v->next_member, v->t, member) { | |
3168 | u32 member_type_id = member->type; | |
3169 | const struct btf_type *member_type = btf_type_by_id(env->btf, | |
3170 | member_type_id); | |
3171 | ||
e4f07120 SF |
3172 | if (btf_type_nosize_or_null(member_type) || |
3173 | btf_type_is_resolve_source_only(member_type)) { | |
eb3f595d MKL |
3174 | btf_verifier_log_member(env, v->t, member, |
3175 | "Invalid member"); | |
3176 | return -EINVAL; | |
3177 | } | |
3178 | ||
3179 | if (!env_type_is_resolve_sink(env, member_type) && | |
3180 | !env_type_is_resolved(env, member_type_id)) { | |
3181 | env_stack_set_next_member(env, i + 1); | |
3182 | return env_stack_push(env, member_type, member_type_id); | |
3183 | } | |
179cde8c | 3184 | |
9d5f9f70 YS |
3185 | if (btf_type_kflag(v->t)) |
3186 | err = btf_type_ops(member_type)->check_kflag_member(env, v->t, | |
3187 | member, | |
3188 | member_type); | |
3189 | else | |
3190 | err = btf_type_ops(member_type)->check_member(env, v->t, | |
3191 | member, | |
3192 | member_type); | |
179cde8c MKL |
3193 | if (err) |
3194 | return err; | |
eb3f595d MKL |
3195 | } |
3196 | ||
3197 | env_stack_pop_resolved(env, 0, 0); | |
3198 | ||
3199 | return 0; | |
3200 | } | |
3201 | ||
69b693f0 MKL |
3202 | static void btf_struct_log(struct btf_verifier_env *env, |
3203 | const struct btf_type *t) | |
3204 | { | |
3205 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
3206 | } | |
3207 | ||
aa3496ac | 3208 | enum btf_field_info_type { |
42ba1308 KKD |
3209 | BTF_FIELD_SPIN_LOCK, |
3210 | BTF_FIELD_TIMER, | |
61df10c7 KKD |
3211 | BTF_FIELD_KPTR, |
3212 | }; | |
3213 | ||
3214 | enum { | |
3215 | BTF_FIELD_IGNORE = 0, | |
3216 | BTF_FIELD_FOUND = 1, | |
42ba1308 KKD |
3217 | }; |
3218 | ||
3219 | struct btf_field_info { | |
aa3496ac | 3220 | enum btf_field_type type; |
42ba1308 | 3221 | u32 off; |
f0c5941f KKD |
3222 | union { |
3223 | struct { | |
3224 | u32 type_id; | |
3225 | } kptr; | |
3226 | struct { | |
3227 | const char *node_name; | |
3228 | u32 value_btf_id; | |
3229 | } list_head; | |
3230 | }; | |
42ba1308 KKD |
3231 | }; |
3232 | ||
3233 | static int btf_find_struct(const struct btf *btf, const struct btf_type *t, | |
db559117 KKD |
3234 | u32 off, int sz, enum btf_field_type field_type, |
3235 | struct btf_field_info *info) | |
42ba1308 KKD |
3236 | { |
3237 | if (!__btf_type_is_struct(t)) | |
61df10c7 | 3238 | return BTF_FIELD_IGNORE; |
42ba1308 | 3239 | if (t->size != sz) |
61df10c7 | 3240 | return BTF_FIELD_IGNORE; |
db559117 | 3241 | info->type = field_type; |
42ba1308 | 3242 | info->off = off; |
61df10c7 KKD |
3243 | return BTF_FIELD_FOUND; |
3244 | } | |
3245 | ||
3246 | static int btf_find_kptr(const struct btf *btf, const struct btf_type *t, | |
3247 | u32 off, int sz, struct btf_field_info *info) | |
3248 | { | |
aa3496ac | 3249 | enum btf_field_type type; |
61df10c7 KKD |
3250 | u32 res_id; |
3251 | ||
23da464d KKD |
3252 | /* Permit modifiers on the pointer itself */ |
3253 | if (btf_type_is_volatile(t)) | |
3254 | t = btf_type_by_id(btf, t->type); | |
61df10c7 KKD |
3255 | /* For PTR, sz is always == 8 */ |
3256 | if (!btf_type_is_ptr(t)) | |
3257 | return BTF_FIELD_IGNORE; | |
3258 | t = btf_type_by_id(btf, t->type); | |
3259 | ||
3260 | if (!btf_type_is_type_tag(t)) | |
3261 | return BTF_FIELD_IGNORE; | |
3262 | /* Reject extra tags */ | |
3263 | if (btf_type_is_type_tag(btf_type_by_id(btf, t->type))) | |
3264 | return -EINVAL; | |
c0a5a21c KKD |
3265 | if (!strcmp("kptr", __btf_name_by_offset(btf, t->name_off))) |
3266 | type = BPF_KPTR_UNREF; | |
3267 | else if (!strcmp("kptr_ref", __btf_name_by_offset(btf, t->name_off))) | |
3268 | type = BPF_KPTR_REF; | |
3269 | else | |
61df10c7 KKD |
3270 | return -EINVAL; |
3271 | ||
3272 | /* Get the base type */ | |
3273 | t = btf_type_skip_modifiers(btf, t->type, &res_id); | |
3274 | /* Only pointer to struct is allowed */ | |
3275 | if (!__btf_type_is_struct(t)) | |
3276 | return -EINVAL; | |
3277 | ||
c0a5a21c | 3278 | info->type = type; |
db559117 KKD |
3279 | info->off = off; |
3280 | info->kptr.type_id = res_id; | |
61df10c7 | 3281 | return BTF_FIELD_FOUND; |
42ba1308 KKD |
3282 | } |
3283 | ||
f0c5941f KKD |
3284 | static const char *btf_find_decl_tag_value(const struct btf *btf, |
3285 | const struct btf_type *pt, | |
3286 | int comp_idx, const char *tag_key) | |
3287 | { | |
3288 | int i; | |
3289 | ||
3290 | for (i = 1; i < btf_nr_types(btf); i++) { | |
3291 | const struct btf_type *t = btf_type_by_id(btf, i); | |
3292 | int len = strlen(tag_key); | |
3293 | ||
3294 | if (!btf_type_is_decl_tag(t)) | |
3295 | continue; | |
3296 | if (pt != btf_type_by_id(btf, t->type) || | |
3297 | btf_type_decl_tag(t)->component_idx != comp_idx) | |
3298 | continue; | |
3299 | if (strncmp(__btf_name_by_offset(btf, t->name_off), tag_key, len)) | |
3300 | continue; | |
3301 | return __btf_name_by_offset(btf, t->name_off) + len; | |
3302 | } | |
3303 | return NULL; | |
3304 | } | |
3305 | ||
3306 | static int btf_find_list_head(const struct btf *btf, const struct btf_type *pt, | |
3307 | const struct btf_type *t, int comp_idx, | |
3308 | u32 off, int sz, struct btf_field_info *info) | |
3309 | { | |
3310 | const char *value_type; | |
3311 | const char *list_node; | |
3312 | s32 id; | |
3313 | ||
3314 | if (!__btf_type_is_struct(t)) | |
3315 | return BTF_FIELD_IGNORE; | |
3316 | if (t->size != sz) | |
3317 | return BTF_FIELD_IGNORE; | |
3318 | value_type = btf_find_decl_tag_value(btf, pt, comp_idx, "contains:"); | |
3319 | if (!value_type) | |
3320 | return -EINVAL; | |
3321 | list_node = strstr(value_type, ":"); | |
3322 | if (!list_node) | |
3323 | return -EINVAL; | |
3324 | value_type = kstrndup(value_type, list_node - value_type, GFP_KERNEL | __GFP_NOWARN); | |
3325 | if (!value_type) | |
3326 | return -ENOMEM; | |
3327 | id = btf_find_by_name_kind(btf, value_type, BTF_KIND_STRUCT); | |
3328 | kfree(value_type); | |
3329 | if (id < 0) | |
3330 | return id; | |
3331 | list_node++; | |
3332 | if (str_is_empty(list_node)) | |
3333 | return -EINVAL; | |
3334 | info->type = BPF_LIST_HEAD; | |
3335 | info->off = off; | |
3336 | info->list_head.value_btf_id = id; | |
3337 | info->list_head.node_name = list_node; | |
3338 | return BTF_FIELD_FOUND; | |
3339 | } | |
3340 | ||
db559117 KKD |
3341 | static int btf_get_field_type(const char *name, u32 field_mask, u32 *seen_mask, |
3342 | int *align, int *sz) | |
3343 | { | |
3344 | int type = 0; | |
3345 | ||
3346 | if (field_mask & BPF_SPIN_LOCK) { | |
3347 | if (!strcmp(name, "bpf_spin_lock")) { | |
3348 | if (*seen_mask & BPF_SPIN_LOCK) | |
3349 | return -E2BIG; | |
3350 | *seen_mask |= BPF_SPIN_LOCK; | |
3351 | type = BPF_SPIN_LOCK; | |
3352 | goto end; | |
3353 | } | |
3354 | } | |
3355 | if (field_mask & BPF_TIMER) { | |
3356 | if (!strcmp(name, "bpf_timer")) { | |
3357 | if (*seen_mask & BPF_TIMER) | |
3358 | return -E2BIG; | |
3359 | *seen_mask |= BPF_TIMER; | |
3360 | type = BPF_TIMER; | |
3361 | goto end; | |
3362 | } | |
3363 | } | |
f0c5941f KKD |
3364 | if (field_mask & BPF_LIST_HEAD) { |
3365 | if (!strcmp(name, "bpf_list_head")) { | |
3366 | type = BPF_LIST_HEAD; | |
3367 | goto end; | |
3368 | } | |
3369 | } | |
8ffa5cc1 KKD |
3370 | if (field_mask & BPF_LIST_NODE) { |
3371 | if (!strcmp(name, "bpf_list_node")) { | |
3372 | type = BPF_LIST_NODE; | |
3373 | goto end; | |
3374 | } | |
3375 | } | |
db559117 KKD |
3376 | /* Only return BPF_KPTR when all other types with matchable names fail */ |
3377 | if (field_mask & BPF_KPTR) { | |
3378 | type = BPF_KPTR_REF; | |
3379 | goto end; | |
3380 | } | |
3381 | return 0; | |
3382 | end: | |
3383 | *sz = btf_field_type_size(type); | |
3384 | *align = btf_field_type_align(type); | |
3385 | return type; | |
3386 | } | |
3387 | ||
3388 | static int btf_find_struct_field(const struct btf *btf, | |
3389 | const struct btf_type *t, u32 field_mask, | |
61df10c7 | 3390 | struct btf_field_info *info, int info_cnt) |
d83525ca | 3391 | { |
db559117 | 3392 | int ret, idx = 0, align, sz, field_type; |
d83525ca | 3393 | const struct btf_member *member; |
61df10c7 | 3394 | struct btf_field_info tmp; |
db559117 | 3395 | u32 i, off, seen_mask = 0; |
d83525ca | 3396 | |
d83525ca AS |
3397 | for_each_member(i, t, member) { |
3398 | const struct btf_type *member_type = btf_type_by_id(btf, | |
3399 | member->type); | |
42ba1308 | 3400 | |
db559117 KKD |
3401 | field_type = btf_get_field_type(__btf_name_by_offset(btf, member_type->name_off), |
3402 | field_mask, &seen_mask, &align, &sz); | |
3403 | if (field_type == 0) | |
d83525ca | 3404 | continue; |
db559117 KKD |
3405 | if (field_type < 0) |
3406 | return field_type; | |
42ba1308 | 3407 | |
8293eb99 | 3408 | off = __btf_member_bit_offset(t, member); |
d83525ca AS |
3409 | if (off % 8) |
3410 | /* valid C code cannot generate such BTF */ | |
3411 | return -EINVAL; | |
3412 | off /= 8; | |
68134668 | 3413 | if (off % align) |
db559117 | 3414 | continue; |
42ba1308 KKD |
3415 | |
3416 | switch (field_type) { | |
db559117 KKD |
3417 | case BPF_SPIN_LOCK: |
3418 | case BPF_TIMER: | |
8ffa5cc1 | 3419 | case BPF_LIST_NODE: |
db559117 | 3420 | ret = btf_find_struct(btf, member_type, off, sz, field_type, |
61df10c7 KKD |
3421 | idx < info_cnt ? &info[idx] : &tmp); |
3422 | if (ret < 0) | |
3423 | return ret; | |
3424 | break; | |
db559117 KKD |
3425 | case BPF_KPTR_UNREF: |
3426 | case BPF_KPTR_REF: | |
61df10c7 KKD |
3427 | ret = btf_find_kptr(btf, member_type, off, sz, |
3428 | idx < info_cnt ? &info[idx] : &tmp); | |
3429 | if (ret < 0) | |
3430 | return ret; | |
3431 | break; | |
f0c5941f KKD |
3432 | case BPF_LIST_HEAD: |
3433 | ret = btf_find_list_head(btf, t, member_type, i, off, sz, | |
3434 | idx < info_cnt ? &info[idx] : &tmp); | |
3435 | if (ret < 0) | |
3436 | return ret; | |
3437 | break; | |
42ba1308 KKD |
3438 | default: |
3439 | return -EFAULT; | |
3440 | } | |
61df10c7 KKD |
3441 | |
3442 | if (ret == BTF_FIELD_IGNORE) | |
3443 | continue; | |
3444 | if (idx >= info_cnt) | |
3445 | return -E2BIG; | |
3446 | ++idx; | |
68134668 | 3447 | } |
61df10c7 | 3448 | return idx; |
68134668 AS |
3449 | } |
3450 | ||
3451 | static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t, | |
db559117 KKD |
3452 | u32 field_mask, struct btf_field_info *info, |
3453 | int info_cnt) | |
68134668 | 3454 | { |
db559117 | 3455 | int ret, idx = 0, align, sz, field_type; |
68134668 | 3456 | const struct btf_var_secinfo *vsi; |
61df10c7 | 3457 | struct btf_field_info tmp; |
db559117 | 3458 | u32 i, off, seen_mask = 0; |
68134668 AS |
3459 | |
3460 | for_each_vsi(i, t, vsi) { | |
3461 | const struct btf_type *var = btf_type_by_id(btf, vsi->type); | |
3462 | const struct btf_type *var_type = btf_type_by_id(btf, var->type); | |
3463 | ||
db559117 KKD |
3464 | field_type = btf_get_field_type(__btf_name_by_offset(btf, var_type->name_off), |
3465 | field_mask, &seen_mask, &align, &sz); | |
3466 | if (field_type == 0) | |
68134668 | 3467 | continue; |
db559117 KKD |
3468 | if (field_type < 0) |
3469 | return field_type; | |
3470 | ||
3471 | off = vsi->offset; | |
68134668 AS |
3472 | if (vsi->size != sz) |
3473 | continue; | |
68134668 | 3474 | if (off % align) |
db559117 | 3475 | continue; |
42ba1308 KKD |
3476 | |
3477 | switch (field_type) { | |
db559117 KKD |
3478 | case BPF_SPIN_LOCK: |
3479 | case BPF_TIMER: | |
8ffa5cc1 | 3480 | case BPF_LIST_NODE: |
db559117 | 3481 | ret = btf_find_struct(btf, var_type, off, sz, field_type, |
61df10c7 KKD |
3482 | idx < info_cnt ? &info[idx] : &tmp); |
3483 | if (ret < 0) | |
3484 | return ret; | |
3485 | break; | |
db559117 KKD |
3486 | case BPF_KPTR_UNREF: |
3487 | case BPF_KPTR_REF: | |
61df10c7 KKD |
3488 | ret = btf_find_kptr(btf, var_type, off, sz, |
3489 | idx < info_cnt ? &info[idx] : &tmp); | |
3490 | if (ret < 0) | |
3491 | return ret; | |
3492 | break; | |
f0c5941f KKD |
3493 | case BPF_LIST_HEAD: |
3494 | ret = btf_find_list_head(btf, var, var_type, -1, off, sz, | |
3495 | idx < info_cnt ? &info[idx] : &tmp); | |
3496 | if (ret < 0) | |
3497 | return ret; | |
3498 | break; | |
42ba1308 KKD |
3499 | default: |
3500 | return -EFAULT; | |
3501 | } | |
61df10c7 KKD |
3502 | |
3503 | if (ret == BTF_FIELD_IGNORE) | |
3504 | continue; | |
3505 | if (idx >= info_cnt) | |
3506 | return -E2BIG; | |
3507 | ++idx; | |
d83525ca | 3508 | } |
61df10c7 | 3509 | return idx; |
d83525ca AS |
3510 | } |
3511 | ||
68134668 | 3512 | static int btf_find_field(const struct btf *btf, const struct btf_type *t, |
db559117 KKD |
3513 | u32 field_mask, struct btf_field_info *info, |
3514 | int info_cnt) | |
68134668 | 3515 | { |
68134668 | 3516 | if (__btf_type_is_struct(t)) |
db559117 | 3517 | return btf_find_struct_field(btf, t, field_mask, info, info_cnt); |
68134668 | 3518 | else if (btf_type_is_datasec(t)) |
db559117 | 3519 | return btf_find_datasec_var(btf, t, field_mask, info, info_cnt); |
68134668 AS |
3520 | return -EINVAL; |
3521 | } | |
3522 | ||
db559117 KKD |
3523 | static int btf_parse_kptr(const struct btf *btf, struct btf_field *field, |
3524 | struct btf_field_info *info) | |
68134668 | 3525 | { |
db559117 KKD |
3526 | struct module *mod = NULL; |
3527 | const struct btf_type *t; | |
3528 | struct btf *kernel_btf; | |
42ba1308 | 3529 | int ret; |
db559117 | 3530 | s32 id; |
42ba1308 | 3531 | |
db559117 KKD |
3532 | /* Find type in map BTF, and use it to look up the matching type |
3533 | * in vmlinux or module BTFs, by name and kind. | |
3534 | */ | |
3535 | t = btf_type_by_id(btf, info->kptr.type_id); | |
3536 | id = bpf_find_btf_id(__btf_name_by_offset(btf, t->name_off), BTF_INFO_KIND(t->info), | |
3537 | &kernel_btf); | |
3538 | if (id < 0) | |
3539 | return id; | |
3540 | ||
3541 | /* Find and stash the function pointer for the destruction function that | |
3542 | * needs to be eventually invoked from the map free path. | |
3543 | */ | |
3544 | if (info->type == BPF_KPTR_REF) { | |
3545 | const struct btf_type *dtor_func; | |
3546 | const char *dtor_func_name; | |
3547 | unsigned long addr; | |
3548 | s32 dtor_btf_id; | |
3549 | ||
3550 | /* This call also serves as a whitelist of allowed objects that | |
3551 | * can be used as a referenced pointer and be stored in a map at | |
3552 | * the same time. | |
3553 | */ | |
3554 | dtor_btf_id = btf_find_dtor_kfunc(kernel_btf, id); | |
3555 | if (dtor_btf_id < 0) { | |
3556 | ret = dtor_btf_id; | |
3557 | goto end_btf; | |
3558 | } | |
68134668 | 3559 | |
db559117 KKD |
3560 | dtor_func = btf_type_by_id(kernel_btf, dtor_btf_id); |
3561 | if (!dtor_func) { | |
3562 | ret = -ENOENT; | |
3563 | goto end_btf; | |
3564 | } | |
42ba1308 | 3565 | |
db559117 KKD |
3566 | if (btf_is_module(kernel_btf)) { |
3567 | mod = btf_try_get_module(kernel_btf); | |
3568 | if (!mod) { | |
3569 | ret = -ENXIO; | |
3570 | goto end_btf; | |
3571 | } | |
3572 | } | |
3573 | ||
3574 | /* We already verified dtor_func to be btf_type_is_func | |
3575 | * in register_btf_id_dtor_kfuncs. | |
3576 | */ | |
3577 | dtor_func_name = __btf_name_by_offset(kernel_btf, dtor_func->name_off); | |
3578 | addr = kallsyms_lookup_name(dtor_func_name); | |
3579 | if (!addr) { | |
3580 | ret = -EINVAL; | |
3581 | goto end_mod; | |
3582 | } | |
3583 | field->kptr.dtor = (void *)addr; | |
3584 | } | |
3585 | ||
3586 | field->kptr.btf_id = id; | |
3587 | field->kptr.btf = kernel_btf; | |
3588 | field->kptr.module = mod; | |
3589 | return 0; | |
3590 | end_mod: | |
3591 | module_put(mod); | |
3592 | end_btf: | |
3593 | btf_put(kernel_btf); | |
3594 | return ret; | |
68134668 AS |
3595 | } |
3596 | ||
f0c5941f KKD |
3597 | static int btf_parse_list_head(const struct btf *btf, struct btf_field *field, |
3598 | struct btf_field_info *info) | |
3599 | { | |
3600 | const struct btf_type *t, *n = NULL; | |
3601 | const struct btf_member *member; | |
3602 | u32 offset; | |
3603 | int i; | |
3604 | ||
3605 | t = btf_type_by_id(btf, info->list_head.value_btf_id); | |
3606 | /* We've already checked that value_btf_id is a struct type. We | |
3607 | * just need to figure out the offset of the list_node, and | |
3608 | * verify its type. | |
3609 | */ | |
3610 | for_each_member(i, t, member) { | |
3611 | if (strcmp(info->list_head.node_name, __btf_name_by_offset(btf, member->name_off))) | |
3612 | continue; | |
3613 | /* Invalid BTF, two members with same name */ | |
3614 | if (n) | |
3615 | return -EINVAL; | |
3616 | n = btf_type_by_id(btf, member->type); | |
3617 | if (!__btf_type_is_struct(n)) | |
3618 | return -EINVAL; | |
3619 | if (strcmp("bpf_list_node", __btf_name_by_offset(btf, n->name_off))) | |
3620 | return -EINVAL; | |
3621 | offset = __btf_member_bit_offset(n, member); | |
3622 | if (offset % 8) | |
3623 | return -EINVAL; | |
3624 | offset /= 8; | |
3625 | if (offset % __alignof__(struct bpf_list_node)) | |
3626 | return -EINVAL; | |
3627 | ||
3628 | field->list_head.btf = (struct btf *)btf; | |
3629 | field->list_head.value_btf_id = info->list_head.value_btf_id; | |
3630 | field->list_head.node_offset = offset; | |
3631 | } | |
3632 | if (!n) | |
3633 | return -ENOENT; | |
3634 | return 0; | |
3635 | } | |
3636 | ||
db559117 KKD |
3637 | struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t, |
3638 | u32 field_mask, u32 value_size) | |
61df10c7 | 3639 | { |
aa3496ac | 3640 | struct btf_field_info info_arr[BTF_FIELDS_MAX]; |
aa3496ac | 3641 | struct btf_record *rec; |
f0c5941f | 3642 | u32 next_off = 0; |
aa3496ac | 3643 | int ret, i, cnt; |
61df10c7 | 3644 | |
db559117 | 3645 | ret = btf_find_field(btf, t, field_mask, info_arr, ARRAY_SIZE(info_arr)); |
61df10c7 KKD |
3646 | if (ret < 0) |
3647 | return ERR_PTR(ret); | |
3648 | if (!ret) | |
3649 | return NULL; | |
3650 | ||
aa3496ac | 3651 | cnt = ret; |
c22dfdd2 KKD |
3652 | /* This needs to be kzalloc to zero out padding and unused fields, see |
3653 | * comment in btf_record_equal. | |
3654 | */ | |
aa3496ac KKD |
3655 | rec = kzalloc(offsetof(struct btf_record, fields[cnt]), GFP_KERNEL | __GFP_NOWARN); |
3656 | if (!rec) | |
61df10c7 | 3657 | return ERR_PTR(-ENOMEM); |
61df10c7 | 3658 | |
db559117 KKD |
3659 | rec->spin_lock_off = -EINVAL; |
3660 | rec->timer_off = -EINVAL; | |
3661 | for (i = 0; i < cnt; i++) { | |
3662 | if (info_arr[i].off + btf_field_type_size(info_arr[i].type) > value_size) { | |
3663 | WARN_ONCE(1, "verifier bug off %d size %d", info_arr[i].off, value_size); | |
3664 | ret = -EFAULT; | |
61df10c7 KKD |
3665 | goto end; |
3666 | } | |
f0c5941f KKD |
3667 | if (info_arr[i].off < next_off) { |
3668 | ret = -EEXIST; | |
3669 | goto end; | |
3670 | } | |
3671 | next_off = info_arr[i].off + btf_field_type_size(info_arr[i].type); | |
61df10c7 | 3672 | |
aa3496ac KKD |
3673 | rec->field_mask |= info_arr[i].type; |
3674 | rec->fields[i].offset = info_arr[i].off; | |
3675 | rec->fields[i].type = info_arr[i].type; | |
db559117 KKD |
3676 | |
3677 | switch (info_arr[i].type) { | |
3678 | case BPF_SPIN_LOCK: | |
3679 | WARN_ON_ONCE(rec->spin_lock_off >= 0); | |
3680 | /* Cache offset for faster lookup at runtime */ | |
3681 | rec->spin_lock_off = rec->fields[i].offset; | |
3682 | break; | |
3683 | case BPF_TIMER: | |
3684 | WARN_ON_ONCE(rec->timer_off >= 0); | |
3685 | /* Cache offset for faster lookup at runtime */ | |
3686 | rec->timer_off = rec->fields[i].offset; | |
3687 | break; | |
3688 | case BPF_KPTR_UNREF: | |
3689 | case BPF_KPTR_REF: | |
3690 | ret = btf_parse_kptr(btf, &rec->fields[i], &info_arr[i]); | |
3691 | if (ret < 0) | |
3692 | goto end; | |
3693 | break; | |
f0c5941f KKD |
3694 | case BPF_LIST_HEAD: |
3695 | ret = btf_parse_list_head(btf, &rec->fields[i], &info_arr[i]); | |
3696 | if (ret < 0) | |
3697 | goto end; | |
3698 | break; | |
8ffa5cc1 KKD |
3699 | case BPF_LIST_NODE: |
3700 | break; | |
db559117 KKD |
3701 | default: |
3702 | ret = -EFAULT; | |
3703 | goto end; | |
3704 | } | |
aa3496ac | 3705 | rec->cnt++; |
61df10c7 | 3706 | } |
f0c5941f KKD |
3707 | |
3708 | /* bpf_list_head requires bpf_spin_lock */ | |
3709 | if (btf_record_has_field(rec, BPF_LIST_HEAD) && rec->spin_lock_off < 0) { | |
3710 | ret = -EINVAL; | |
3711 | goto end; | |
3712 | } | |
3713 | ||
aa3496ac | 3714 | return rec; |
61df10c7 | 3715 | end: |
aa3496ac | 3716 | btf_record_free(rec); |
61df10c7 KKD |
3717 | return ERR_PTR(ret); |
3718 | } | |
3719 | ||
865ce09a KKD |
3720 | int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec) |
3721 | { | |
3722 | int i; | |
3723 | ||
3724 | /* There are two owning types, kptr_ref and bpf_list_head. The former | |
3725 | * only supports storing kernel types, which can never store references | |
3726 | * to program allocated local types, atleast not yet. Hence we only need | |
3727 | * to ensure that bpf_list_head ownership does not form cycles. | |
3728 | */ | |
3729 | if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & BPF_LIST_HEAD)) | |
3730 | return 0; | |
3731 | for (i = 0; i < rec->cnt; i++) { | |
3732 | struct btf_struct_meta *meta; | |
3733 | u32 btf_id; | |
3734 | ||
3735 | if (!(rec->fields[i].type & BPF_LIST_HEAD)) | |
3736 | continue; | |
3737 | btf_id = rec->fields[i].list_head.value_btf_id; | |
3738 | meta = btf_find_struct_meta(btf, btf_id); | |
3739 | if (!meta) | |
3740 | return -EFAULT; | |
3741 | rec->fields[i].list_head.value_rec = meta->record; | |
3742 | ||
3743 | if (!(rec->field_mask & BPF_LIST_NODE)) | |
3744 | continue; | |
3745 | ||
3746 | /* We need to ensure ownership acyclicity among all types. The | |
3747 | * proper way to do it would be to topologically sort all BTF | |
3748 | * IDs based on the ownership edges, since there can be multiple | |
3749 | * bpf_list_head in a type. Instead, we use the following | |
3750 | * reasoning: | |
3751 | * | |
3752 | * - A type can only be owned by another type in user BTF if it | |
3753 | * has a bpf_list_node. | |
3754 | * - A type can only _own_ another type in user BTF if it has a | |
3755 | * bpf_list_head. | |
3756 | * | |
3757 | * We ensure that if a type has both bpf_list_head and | |
3758 | * bpf_list_node, its element types cannot be owning types. | |
3759 | * | |
3760 | * To ensure acyclicity: | |
3761 | * | |
3762 | * When A only has bpf_list_head, ownership chain can be: | |
3763 | * A -> B -> C | |
3764 | * Where: | |
3765 | * - B has both bpf_list_head and bpf_list_node. | |
3766 | * - C only has bpf_list_node. | |
3767 | * | |
3768 | * When A has both bpf_list_head and bpf_list_node, some other | |
3769 | * type already owns it in the BTF domain, hence it can not own | |
3770 | * another owning type through any of the bpf_list_head edges. | |
3771 | * A -> B | |
3772 | * Where: | |
3773 | * - B only has bpf_list_node. | |
3774 | */ | |
3775 | if (meta->record->field_mask & BPF_LIST_HEAD) | |
3776 | return -ELOOP; | |
3777 | } | |
3778 | return 0; | |
3779 | } | |
3780 | ||
f71b2f64 KKD |
3781 | static int btf_field_offs_cmp(const void *_a, const void *_b, const void *priv) |
3782 | { | |
3783 | const u32 a = *(const u32 *)_a; | |
3784 | const u32 b = *(const u32 *)_b; | |
3785 | ||
3786 | if (a < b) | |
3787 | return -1; | |
3788 | else if (a > b) | |
3789 | return 1; | |
3790 | return 0; | |
3791 | } | |
3792 | ||
3793 | static void btf_field_offs_swap(void *_a, void *_b, int size, const void *priv) | |
3794 | { | |
3795 | struct btf_field_offs *foffs = (void *)priv; | |
3796 | u32 *off_base = foffs->field_off; | |
3797 | u32 *a = _a, *b = _b; | |
3798 | u8 *sz_a, *sz_b; | |
3799 | ||
3800 | sz_a = foffs->field_sz + (a - off_base); | |
3801 | sz_b = foffs->field_sz + (b - off_base); | |
3802 | ||
3803 | swap(*a, *b); | |
3804 | swap(*sz_a, *sz_b); | |
3805 | } | |
3806 | ||
3807 | struct btf_field_offs *btf_parse_field_offs(struct btf_record *rec) | |
3808 | { | |
3809 | struct btf_field_offs *foffs; | |
3810 | u32 i, *off; | |
3811 | u8 *sz; | |
3812 | ||
3813 | BUILD_BUG_ON(ARRAY_SIZE(foffs->field_off) != ARRAY_SIZE(foffs->field_sz)); | |
2d577252 | 3814 | if (IS_ERR_OR_NULL(rec)) |
f71b2f64 KKD |
3815 | return NULL; |
3816 | ||
3817 | foffs = kzalloc(sizeof(*foffs), GFP_KERNEL | __GFP_NOWARN); | |
3818 | if (!foffs) | |
3819 | return ERR_PTR(-ENOMEM); | |
3820 | ||
3821 | off = foffs->field_off; | |
3822 | sz = foffs->field_sz; | |
3823 | for (i = 0; i < rec->cnt; i++) { | |
3824 | off[i] = rec->fields[i].offset; | |
3825 | sz[i] = btf_field_type_size(rec->fields[i].type); | |
3826 | } | |
3827 | foffs->cnt = rec->cnt; | |
3828 | ||
3829 | if (foffs->cnt == 1) | |
3830 | return foffs; | |
3831 | sort_r(foffs->field_off, foffs->cnt, sizeof(foffs->field_off[0]), | |
3832 | btf_field_offs_cmp, btf_field_offs_swap, foffs); | |
3833 | return foffs; | |
3834 | } | |
3835 | ||
31d0bc81 AM |
3836 | static void __btf_struct_show(const struct btf *btf, const struct btf_type *t, |
3837 | u32 type_id, void *data, u8 bits_offset, | |
3838 | struct btf_show *show) | |
b00b8dae | 3839 | { |
b00b8dae | 3840 | const struct btf_member *member; |
31d0bc81 | 3841 | void *safe_data; |
b00b8dae MKL |
3842 | u32 i; |
3843 | ||
31d0bc81 AM |
3844 | safe_data = btf_show_start_struct_type(show, t, type_id, data); |
3845 | if (!safe_data) | |
3846 | return; | |
3847 | ||
b00b8dae MKL |
3848 | for_each_member(i, t, member) { |
3849 | const struct btf_type *member_type = btf_type_by_id(btf, | |
3850 | member->type); | |
b00b8dae | 3851 | const struct btf_kind_operations *ops; |
9d5f9f70 YS |
3852 | u32 member_offset, bitfield_size; |
3853 | u32 bytes_offset; | |
3854 | u8 bits8_offset; | |
b00b8dae | 3855 | |
31d0bc81 | 3856 | btf_show_start_member(show, member); |
b00b8dae | 3857 | |
8293eb99 AS |
3858 | member_offset = __btf_member_bit_offset(t, member); |
3859 | bitfield_size = __btf_member_bitfield_size(t, member); | |
17e3ac81 YS |
3860 | bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset); |
3861 | bits8_offset = BITS_PER_BYTE_MASKED(member_offset); | |
9d5f9f70 | 3862 | if (bitfield_size) { |
31d0bc81 AM |
3863 | safe_data = btf_show_start_type(show, member_type, |
3864 | member->type, | |
3865 | data + bytes_offset); | |
3866 | if (safe_data) | |
3867 | btf_bitfield_show(safe_data, | |
3868 | bits8_offset, | |
3869 | bitfield_size, show); | |
3870 | btf_show_end_type(show); | |
9d5f9f70 | 3871 | } else { |
9d5f9f70 | 3872 | ops = btf_type_ops(member_type); |
31d0bc81 AM |
3873 | ops->show(btf, member_type, member->type, |
3874 | data + bytes_offset, bits8_offset, show); | |
9d5f9f70 | 3875 | } |
31d0bc81 AM |
3876 | |
3877 | btf_show_end_member(show); | |
b00b8dae | 3878 | } |
31d0bc81 AM |
3879 | |
3880 | btf_show_end_struct_type(show); | |
3881 | } | |
3882 | ||
3883 | static void btf_struct_show(const struct btf *btf, const struct btf_type *t, | |
3884 | u32 type_id, void *data, u8 bits_offset, | |
3885 | struct btf_show *show) | |
3886 | { | |
3887 | const struct btf_member *m = show->state.member; | |
3888 | ||
3889 | /* | |
3890 | * First check if any members would be shown (are non-zero). | |
3891 | * See comments above "struct btf_show" definition for more | |
3892 | * details on how this works at a high-level. | |
3893 | */ | |
3894 | if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) { | |
3895 | if (!show->state.depth_check) { | |
3896 | show->state.depth_check = show->state.depth + 1; | |
3897 | show->state.depth_to_show = 0; | |
3898 | } | |
3899 | __btf_struct_show(btf, t, type_id, data, bits_offset, show); | |
3900 | /* Restore saved member data here */ | |
3901 | show->state.member = m; | |
3902 | if (show->state.depth_check != show->state.depth + 1) | |
3903 | return; | |
3904 | show->state.depth_check = 0; | |
3905 | ||
3906 | if (show->state.depth_to_show <= show->state.depth) | |
3907 | return; | |
3908 | /* | |
3909 | * Reaching here indicates we have recursed and found | |
3910 | * non-zero child values. | |
3911 | */ | |
3912 | } | |
3913 | ||
3914 | __btf_struct_show(btf, t, type_id, data, bits_offset, show); | |
b00b8dae MKL |
3915 | } |
3916 | ||
69b693f0 MKL |
3917 | static struct btf_kind_operations struct_ops = { |
3918 | .check_meta = btf_struct_check_meta, | |
eb3f595d | 3919 | .resolve = btf_struct_resolve, |
179cde8c | 3920 | .check_member = btf_struct_check_member, |
9d5f9f70 | 3921 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 3922 | .log_details = btf_struct_log, |
31d0bc81 | 3923 | .show = btf_struct_show, |
69b693f0 MKL |
3924 | }; |
3925 | ||
179cde8c MKL |
3926 | static int btf_enum_check_member(struct btf_verifier_env *env, |
3927 | const struct btf_type *struct_type, | |
3928 | const struct btf_member *member, | |
3929 | const struct btf_type *member_type) | |
3930 | { | |
3931 | u32 struct_bits_off = member->offset; | |
3932 | u32 struct_size, bytes_offset; | |
3933 | ||
3934 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
3935 | btf_verifier_log_member(env, struct_type, member, | |
3936 | "Member is not byte aligned"); | |
3937 | return -EINVAL; | |
3938 | } | |
3939 | ||
3940 | struct_size = struct_type->size; | |
3941 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
da6c7fae | 3942 | if (struct_size - bytes_offset < member_type->size) { |
179cde8c MKL |
3943 | btf_verifier_log_member(env, struct_type, member, |
3944 | "Member exceeds struct_size"); | |
3945 | return -EINVAL; | |
3946 | } | |
3947 | ||
3948 | return 0; | |
3949 | } | |
3950 | ||
9d5f9f70 YS |
3951 | static int btf_enum_check_kflag_member(struct btf_verifier_env *env, |
3952 | const struct btf_type *struct_type, | |
3953 | const struct btf_member *member, | |
3954 | const struct btf_type *member_type) | |
3955 | { | |
3956 | u32 struct_bits_off, nr_bits, bytes_end, struct_size; | |
3957 | u32 int_bitsize = sizeof(int) * BITS_PER_BYTE; | |
3958 | ||
3959 | struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); | |
3960 | nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); | |
3961 | if (!nr_bits) { | |
3962 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
3963 | btf_verifier_log_member(env, struct_type, member, | |
3964 | "Member is not byte aligned"); | |
e3439af4 | 3965 | return -EINVAL; |
9d5f9f70 YS |
3966 | } |
3967 | ||
3968 | nr_bits = int_bitsize; | |
3969 | } else if (nr_bits > int_bitsize) { | |
3970 | btf_verifier_log_member(env, struct_type, member, | |
3971 | "Invalid member bitfield_size"); | |
3972 | return -EINVAL; | |
3973 | } | |
3974 | ||
3975 | struct_size = struct_type->size; | |
3976 | bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits); | |
3977 | if (struct_size < bytes_end) { | |
3978 | btf_verifier_log_member(env, struct_type, member, | |
3979 | "Member exceeds struct_size"); | |
3980 | return -EINVAL; | |
3981 | } | |
3982 | ||
3983 | return 0; | |
3984 | } | |
3985 | ||
69b693f0 MKL |
3986 | static s32 btf_enum_check_meta(struct btf_verifier_env *env, |
3987 | const struct btf_type *t, | |
3988 | u32 meta_left) | |
3989 | { | |
3990 | const struct btf_enum *enums = btf_type_enum(t); | |
3991 | struct btf *btf = env->btf; | |
6089fb32 | 3992 | const char *fmt_str; |
69b693f0 MKL |
3993 | u16 i, nr_enums; |
3994 | u32 meta_needed; | |
3995 | ||
3996 | nr_enums = btf_type_vlen(t); | |
3997 | meta_needed = nr_enums * sizeof(*enums); | |
3998 | ||
3999 | if (meta_left < meta_needed) { | |
4000 | btf_verifier_log_basic(env, t, | |
4001 | "meta_left:%u meta_needed:%u", | |
4002 | meta_left, meta_needed); | |
4003 | return -EINVAL; | |
4004 | } | |
4005 | ||
9eea9849 AS |
4006 | if (t->size > 8 || !is_power_of_2(t->size)) { |
4007 | btf_verifier_log_type(env, t, "Unexpected size"); | |
69b693f0 MKL |
4008 | return -EINVAL; |
4009 | } | |
4010 | ||
eb04bbb6 YS |
4011 | /* enum type either no name or a valid one */ |
4012 | if (t->name_off && | |
4013 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
4014 | btf_verifier_log_type(env, t, "Invalid name"); | |
4015 | return -EINVAL; | |
4016 | } | |
4017 | ||
69b693f0 MKL |
4018 | btf_verifier_log_type(env, t, NULL); |
4019 | ||
4020 | for (i = 0; i < nr_enums; i++) { | |
fbcf93eb | 4021 | if (!btf_name_offset_valid(btf, enums[i].name_off)) { |
69b693f0 | 4022 | btf_verifier_log(env, "\tInvalid name_offset:%u", |
fbcf93eb | 4023 | enums[i].name_off); |
69b693f0 MKL |
4024 | return -EINVAL; |
4025 | } | |
4026 | ||
eb04bbb6 YS |
4027 | /* enum member must have a valid name */ |
4028 | if (!enums[i].name_off || | |
4029 | !btf_name_valid_identifier(btf, enums[i].name_off)) { | |
4030 | btf_verifier_log_type(env, t, "Invalid name"); | |
4031 | return -EINVAL; | |
4032 | } | |
4033 | ||
8580ac94 AS |
4034 | if (env->log.level == BPF_LOG_KERNEL) |
4035 | continue; | |
6089fb32 YS |
4036 | fmt_str = btf_type_kflag(t) ? "\t%s val=%d\n" : "\t%s val=%u\n"; |
4037 | btf_verifier_log(env, fmt_str, | |
23127b33 | 4038 | __btf_name_by_offset(btf, enums[i].name_off), |
69b693f0 MKL |
4039 | enums[i].val); |
4040 | } | |
4041 | ||
4042 | return meta_needed; | |
4043 | } | |
4044 | ||
4045 | static void btf_enum_log(struct btf_verifier_env *env, | |
4046 | const struct btf_type *t) | |
4047 | { | |
4048 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
4049 | } | |
4050 | ||
31d0bc81 AM |
4051 | static void btf_enum_show(const struct btf *btf, const struct btf_type *t, |
4052 | u32 type_id, void *data, u8 bits_offset, | |
4053 | struct btf_show *show) | |
b00b8dae MKL |
4054 | { |
4055 | const struct btf_enum *enums = btf_type_enum(t); | |
4056 | u32 i, nr_enums = btf_type_vlen(t); | |
31d0bc81 AM |
4057 | void *safe_data; |
4058 | int v; | |
4059 | ||
4060 | safe_data = btf_show_start_type(show, t, type_id, data); | |
4061 | if (!safe_data) | |
4062 | return; | |
4063 | ||
4064 | v = *(int *)safe_data; | |
b00b8dae MKL |
4065 | |
4066 | for (i = 0; i < nr_enums; i++) { | |
31d0bc81 AM |
4067 | if (v != enums[i].val) |
4068 | continue; | |
4069 | ||
4070 | btf_show_type_value(show, "%s", | |
4071 | __btf_name_by_offset(btf, | |
4072 | enums[i].name_off)); | |
4073 | ||
4074 | btf_show_end_type(show); | |
4075 | return; | |
b00b8dae MKL |
4076 | } |
4077 | ||
6089fb32 YS |
4078 | if (btf_type_kflag(t)) |
4079 | btf_show_type_value(show, "%d", v); | |
4080 | else | |
4081 | btf_show_type_value(show, "%u", v); | |
31d0bc81 | 4082 | btf_show_end_type(show); |
b00b8dae MKL |
4083 | } |
4084 | ||
69b693f0 MKL |
4085 | static struct btf_kind_operations enum_ops = { |
4086 | .check_meta = btf_enum_check_meta, | |
eb3f595d | 4087 | .resolve = btf_df_resolve, |
179cde8c | 4088 | .check_member = btf_enum_check_member, |
9d5f9f70 | 4089 | .check_kflag_member = btf_enum_check_kflag_member, |
69b693f0 | 4090 | .log_details = btf_enum_log, |
31d0bc81 | 4091 | .show = btf_enum_show, |
69b693f0 MKL |
4092 | }; |
4093 | ||
6089fb32 YS |
4094 | static s32 btf_enum64_check_meta(struct btf_verifier_env *env, |
4095 | const struct btf_type *t, | |
4096 | u32 meta_left) | |
4097 | { | |
4098 | const struct btf_enum64 *enums = btf_type_enum64(t); | |
4099 | struct btf *btf = env->btf; | |
4100 | const char *fmt_str; | |
4101 | u16 i, nr_enums; | |
4102 | u32 meta_needed; | |
4103 | ||
4104 | nr_enums = btf_type_vlen(t); | |
4105 | meta_needed = nr_enums * sizeof(*enums); | |
4106 | ||
4107 | if (meta_left < meta_needed) { | |
4108 | btf_verifier_log_basic(env, t, | |
4109 | "meta_left:%u meta_needed:%u", | |
4110 | meta_left, meta_needed); | |
4111 | return -EINVAL; | |
4112 | } | |
4113 | ||
4114 | if (t->size > 8 || !is_power_of_2(t->size)) { | |
4115 | btf_verifier_log_type(env, t, "Unexpected size"); | |
4116 | return -EINVAL; | |
4117 | } | |
4118 | ||
4119 | /* enum type either no name or a valid one */ | |
4120 | if (t->name_off && | |
4121 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
4122 | btf_verifier_log_type(env, t, "Invalid name"); | |
4123 | return -EINVAL; | |
4124 | } | |
4125 | ||
4126 | btf_verifier_log_type(env, t, NULL); | |
4127 | ||
4128 | for (i = 0; i < nr_enums; i++) { | |
4129 | if (!btf_name_offset_valid(btf, enums[i].name_off)) { | |
4130 | btf_verifier_log(env, "\tInvalid name_offset:%u", | |
4131 | enums[i].name_off); | |
4132 | return -EINVAL; | |
4133 | } | |
4134 | ||
4135 | /* enum member must have a valid name */ | |
4136 | if (!enums[i].name_off || | |
4137 | !btf_name_valid_identifier(btf, enums[i].name_off)) { | |
4138 | btf_verifier_log_type(env, t, "Invalid name"); | |
4139 | return -EINVAL; | |
4140 | } | |
4141 | ||
4142 | if (env->log.level == BPF_LOG_KERNEL) | |
4143 | continue; | |
4144 | ||
4145 | fmt_str = btf_type_kflag(t) ? "\t%s val=%lld\n" : "\t%s val=%llu\n"; | |
4146 | btf_verifier_log(env, fmt_str, | |
4147 | __btf_name_by_offset(btf, enums[i].name_off), | |
4148 | btf_enum64_value(enums + i)); | |
4149 | } | |
4150 | ||
4151 | return meta_needed; | |
4152 | } | |
4153 | ||
4154 | static void btf_enum64_show(const struct btf *btf, const struct btf_type *t, | |
4155 | u32 type_id, void *data, u8 bits_offset, | |
4156 | struct btf_show *show) | |
4157 | { | |
4158 | const struct btf_enum64 *enums = btf_type_enum64(t); | |
4159 | u32 i, nr_enums = btf_type_vlen(t); | |
4160 | void *safe_data; | |
4161 | s64 v; | |
4162 | ||
4163 | safe_data = btf_show_start_type(show, t, type_id, data); | |
4164 | if (!safe_data) | |
4165 | return; | |
4166 | ||
4167 | v = *(u64 *)safe_data; | |
4168 | ||
4169 | for (i = 0; i < nr_enums; i++) { | |
4170 | if (v != btf_enum64_value(enums + i)) | |
4171 | continue; | |
4172 | ||
4173 | btf_show_type_value(show, "%s", | |
4174 | __btf_name_by_offset(btf, | |
4175 | enums[i].name_off)); | |
4176 | ||
4177 | btf_show_end_type(show); | |
4178 | return; | |
4179 | } | |
4180 | ||
4181 | if (btf_type_kflag(t)) | |
4182 | btf_show_type_value(show, "%lld", v); | |
4183 | else | |
4184 | btf_show_type_value(show, "%llu", v); | |
4185 | btf_show_end_type(show); | |
4186 | } | |
4187 | ||
4188 | static struct btf_kind_operations enum64_ops = { | |
4189 | .check_meta = btf_enum64_check_meta, | |
4190 | .resolve = btf_df_resolve, | |
4191 | .check_member = btf_enum_check_member, | |
4192 | .check_kflag_member = btf_enum_check_kflag_member, | |
4193 | .log_details = btf_enum_log, | |
4194 | .show = btf_enum64_show, | |
4195 | }; | |
4196 | ||
2667a262 MKL |
4197 | static s32 btf_func_proto_check_meta(struct btf_verifier_env *env, |
4198 | const struct btf_type *t, | |
4199 | u32 meta_left) | |
4200 | { | |
4201 | u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param); | |
4202 | ||
4203 | if (meta_left < meta_needed) { | |
4204 | btf_verifier_log_basic(env, t, | |
4205 | "meta_left:%u meta_needed:%u", | |
4206 | meta_left, meta_needed); | |
4207 | return -EINVAL; | |
4208 | } | |
4209 | ||
4210 | if (t->name_off) { | |
4211 | btf_verifier_log_type(env, t, "Invalid name"); | |
4212 | return -EINVAL; | |
4213 | } | |
4214 | ||
9d5f9f70 YS |
4215 | if (btf_type_kflag(t)) { |
4216 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4217 | return -EINVAL; | |
4218 | } | |
4219 | ||
2667a262 MKL |
4220 | btf_verifier_log_type(env, t, NULL); |
4221 | ||
4222 | return meta_needed; | |
4223 | } | |
4224 | ||
4225 | static void btf_func_proto_log(struct btf_verifier_env *env, | |
4226 | const struct btf_type *t) | |
4227 | { | |
4228 | const struct btf_param *args = (const struct btf_param *)(t + 1); | |
4229 | u16 nr_args = btf_type_vlen(t), i; | |
4230 | ||
4231 | btf_verifier_log(env, "return=%u args=(", t->type); | |
4232 | if (!nr_args) { | |
4233 | btf_verifier_log(env, "void"); | |
4234 | goto done; | |
4235 | } | |
4236 | ||
4237 | if (nr_args == 1 && !args[0].type) { | |
4238 | /* Only one vararg */ | |
4239 | btf_verifier_log(env, "vararg"); | |
4240 | goto done; | |
4241 | } | |
4242 | ||
4243 | btf_verifier_log(env, "%u %s", args[0].type, | |
23127b33 MKL |
4244 | __btf_name_by_offset(env->btf, |
4245 | args[0].name_off)); | |
2667a262 MKL |
4246 | for (i = 1; i < nr_args - 1; i++) |
4247 | btf_verifier_log(env, ", %u %s", args[i].type, | |
23127b33 MKL |
4248 | __btf_name_by_offset(env->btf, |
4249 | args[i].name_off)); | |
2667a262 MKL |
4250 | |
4251 | if (nr_args > 1) { | |
4252 | const struct btf_param *last_arg = &args[nr_args - 1]; | |
4253 | ||
4254 | if (last_arg->type) | |
4255 | btf_verifier_log(env, ", %u %s", last_arg->type, | |
23127b33 MKL |
4256 | __btf_name_by_offset(env->btf, |
4257 | last_arg->name_off)); | |
2667a262 MKL |
4258 | else |
4259 | btf_verifier_log(env, ", vararg"); | |
4260 | } | |
4261 | ||
4262 | done: | |
4263 | btf_verifier_log(env, ")"); | |
4264 | } | |
4265 | ||
4266 | static struct btf_kind_operations func_proto_ops = { | |
4267 | .check_meta = btf_func_proto_check_meta, | |
4268 | .resolve = btf_df_resolve, | |
4269 | /* | |
4270 | * BTF_KIND_FUNC_PROTO cannot be directly referred by | |
4271 | * a struct's member. | |
4272 | * | |
8fb33b60 | 4273 | * It should be a function pointer instead. |
2667a262 MKL |
4274 | * (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO) |
4275 | * | |
4276 | * Hence, there is no btf_func_check_member(). | |
4277 | */ | |
4278 | .check_member = btf_df_check_member, | |
9d5f9f70 | 4279 | .check_kflag_member = btf_df_check_kflag_member, |
2667a262 | 4280 | .log_details = btf_func_proto_log, |
31d0bc81 | 4281 | .show = btf_df_show, |
2667a262 MKL |
4282 | }; |
4283 | ||
4284 | static s32 btf_func_check_meta(struct btf_verifier_env *env, | |
4285 | const struct btf_type *t, | |
4286 | u32 meta_left) | |
4287 | { | |
4288 | if (!t->name_off || | |
4289 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
4290 | btf_verifier_log_type(env, t, "Invalid name"); | |
4291 | return -EINVAL; | |
4292 | } | |
4293 | ||
51c39bb1 AS |
4294 | if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) { |
4295 | btf_verifier_log_type(env, t, "Invalid func linkage"); | |
2667a262 MKL |
4296 | return -EINVAL; |
4297 | } | |
4298 | ||
9d5f9f70 YS |
4299 | if (btf_type_kflag(t)) { |
4300 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4301 | return -EINVAL; | |
4302 | } | |
4303 | ||
2667a262 MKL |
4304 | btf_verifier_log_type(env, t, NULL); |
4305 | ||
4306 | return 0; | |
4307 | } | |
4308 | ||
d7e7b42f YS |
4309 | static int btf_func_resolve(struct btf_verifier_env *env, |
4310 | const struct resolve_vertex *v) | |
4311 | { | |
4312 | const struct btf_type *t = v->t; | |
4313 | u32 next_type_id = t->type; | |
4314 | int err; | |
4315 | ||
4316 | err = btf_func_check(env, t); | |
4317 | if (err) | |
4318 | return err; | |
4319 | ||
4320 | env_stack_pop_resolved(env, next_type_id, 0); | |
4321 | return 0; | |
4322 | } | |
4323 | ||
2667a262 MKL |
4324 | static struct btf_kind_operations func_ops = { |
4325 | .check_meta = btf_func_check_meta, | |
d7e7b42f | 4326 | .resolve = btf_func_resolve, |
2667a262 | 4327 | .check_member = btf_df_check_member, |
9d5f9f70 | 4328 | .check_kflag_member = btf_df_check_kflag_member, |
2667a262 | 4329 | .log_details = btf_ref_type_log, |
31d0bc81 | 4330 | .show = btf_df_show, |
2667a262 MKL |
4331 | }; |
4332 | ||
1dc92851 DB |
4333 | static s32 btf_var_check_meta(struct btf_verifier_env *env, |
4334 | const struct btf_type *t, | |
4335 | u32 meta_left) | |
4336 | { | |
4337 | const struct btf_var *var; | |
4338 | u32 meta_needed = sizeof(*var); | |
4339 | ||
4340 | if (meta_left < meta_needed) { | |
4341 | btf_verifier_log_basic(env, t, | |
4342 | "meta_left:%u meta_needed:%u", | |
4343 | meta_left, meta_needed); | |
4344 | return -EINVAL; | |
4345 | } | |
4346 | ||
4347 | if (btf_type_vlen(t)) { | |
4348 | btf_verifier_log_type(env, t, "vlen != 0"); | |
4349 | return -EINVAL; | |
4350 | } | |
4351 | ||
4352 | if (btf_type_kflag(t)) { | |
4353 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4354 | return -EINVAL; | |
4355 | } | |
4356 | ||
4357 | if (!t->name_off || | |
4358 | !__btf_name_valid(env->btf, t->name_off, true)) { | |
4359 | btf_verifier_log_type(env, t, "Invalid name"); | |
4360 | return -EINVAL; | |
4361 | } | |
4362 | ||
4363 | /* A var cannot be in type void */ | |
4364 | if (!t->type || !BTF_TYPE_ID_VALID(t->type)) { | |
4365 | btf_verifier_log_type(env, t, "Invalid type_id"); | |
4366 | return -EINVAL; | |
4367 | } | |
4368 | ||
4369 | var = btf_type_var(t); | |
4370 | if (var->linkage != BTF_VAR_STATIC && | |
4371 | var->linkage != BTF_VAR_GLOBAL_ALLOCATED) { | |
4372 | btf_verifier_log_type(env, t, "Linkage not supported"); | |
4373 | return -EINVAL; | |
4374 | } | |
4375 | ||
4376 | btf_verifier_log_type(env, t, NULL); | |
4377 | ||
4378 | return meta_needed; | |
4379 | } | |
4380 | ||
4381 | static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t) | |
4382 | { | |
4383 | const struct btf_var *var = btf_type_var(t); | |
4384 | ||
4385 | btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage); | |
4386 | } | |
4387 | ||
4388 | static const struct btf_kind_operations var_ops = { | |
4389 | .check_meta = btf_var_check_meta, | |
4390 | .resolve = btf_var_resolve, | |
4391 | .check_member = btf_df_check_member, | |
4392 | .check_kflag_member = btf_df_check_kflag_member, | |
4393 | .log_details = btf_var_log, | |
31d0bc81 | 4394 | .show = btf_var_show, |
1dc92851 DB |
4395 | }; |
4396 | ||
4397 | static s32 btf_datasec_check_meta(struct btf_verifier_env *env, | |
4398 | const struct btf_type *t, | |
4399 | u32 meta_left) | |
4400 | { | |
4401 | const struct btf_var_secinfo *vsi; | |
4402 | u64 last_vsi_end_off = 0, sum = 0; | |
4403 | u32 i, meta_needed; | |
4404 | ||
4405 | meta_needed = btf_type_vlen(t) * sizeof(*vsi); | |
4406 | if (meta_left < meta_needed) { | |
4407 | btf_verifier_log_basic(env, t, | |
4408 | "meta_left:%u meta_needed:%u", | |
4409 | meta_left, meta_needed); | |
4410 | return -EINVAL; | |
4411 | } | |
4412 | ||
1dc92851 DB |
4413 | if (!t->size) { |
4414 | btf_verifier_log_type(env, t, "size == 0"); | |
4415 | return -EINVAL; | |
4416 | } | |
4417 | ||
4418 | if (btf_type_kflag(t)) { | |
4419 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4420 | return -EINVAL; | |
4421 | } | |
4422 | ||
4423 | if (!t->name_off || | |
4424 | !btf_name_valid_section(env->btf, t->name_off)) { | |
4425 | btf_verifier_log_type(env, t, "Invalid name"); | |
4426 | return -EINVAL; | |
4427 | } | |
4428 | ||
4429 | btf_verifier_log_type(env, t, NULL); | |
4430 | ||
4431 | for_each_vsi(i, t, vsi) { | |
4432 | /* A var cannot be in type void */ | |
4433 | if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) { | |
4434 | btf_verifier_log_vsi(env, t, vsi, | |
4435 | "Invalid type_id"); | |
4436 | return -EINVAL; | |
4437 | } | |
4438 | ||
4439 | if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) { | |
4440 | btf_verifier_log_vsi(env, t, vsi, | |
4441 | "Invalid offset"); | |
4442 | return -EINVAL; | |
4443 | } | |
4444 | ||
4445 | if (!vsi->size || vsi->size > t->size) { | |
4446 | btf_verifier_log_vsi(env, t, vsi, | |
4447 | "Invalid size"); | |
4448 | return -EINVAL; | |
4449 | } | |
4450 | ||
4451 | last_vsi_end_off = vsi->offset + vsi->size; | |
4452 | if (last_vsi_end_off > t->size) { | |
4453 | btf_verifier_log_vsi(env, t, vsi, | |
4454 | "Invalid offset+size"); | |
4455 | return -EINVAL; | |
4456 | } | |
4457 | ||
4458 | btf_verifier_log_vsi(env, t, vsi, NULL); | |
4459 | sum += vsi->size; | |
4460 | } | |
4461 | ||
4462 | if (t->size < sum) { | |
4463 | btf_verifier_log_type(env, t, "Invalid btf_info size"); | |
4464 | return -EINVAL; | |
4465 | } | |
4466 | ||
4467 | return meta_needed; | |
4468 | } | |
4469 | ||
4470 | static int btf_datasec_resolve(struct btf_verifier_env *env, | |
4471 | const struct resolve_vertex *v) | |
4472 | { | |
4473 | const struct btf_var_secinfo *vsi; | |
4474 | struct btf *btf = env->btf; | |
4475 | u16 i; | |
4476 | ||
4477 | for_each_vsi_from(i, v->next_member, v->t, vsi) { | |
4478 | u32 var_type_id = vsi->type, type_id, type_size = 0; | |
4479 | const struct btf_type *var_type = btf_type_by_id(env->btf, | |
4480 | var_type_id); | |
4481 | if (!var_type || !btf_type_is_var(var_type)) { | |
4482 | btf_verifier_log_vsi(env, v->t, vsi, | |
4483 | "Not a VAR kind member"); | |
4484 | return -EINVAL; | |
4485 | } | |
4486 | ||
4487 | if (!env_type_is_resolve_sink(env, var_type) && | |
4488 | !env_type_is_resolved(env, var_type_id)) { | |
4489 | env_stack_set_next_member(env, i + 1); | |
4490 | return env_stack_push(env, var_type, var_type_id); | |
4491 | } | |
4492 | ||
4493 | type_id = var_type->type; | |
4494 | if (!btf_type_id_size(btf, &type_id, &type_size)) { | |
4495 | btf_verifier_log_vsi(env, v->t, vsi, "Invalid type"); | |
4496 | return -EINVAL; | |
4497 | } | |
4498 | ||
4499 | if (vsi->size < type_size) { | |
4500 | btf_verifier_log_vsi(env, v->t, vsi, "Invalid size"); | |
4501 | return -EINVAL; | |
4502 | } | |
4503 | } | |
4504 | ||
4505 | env_stack_pop_resolved(env, 0, 0); | |
4506 | return 0; | |
4507 | } | |
4508 | ||
4509 | static void btf_datasec_log(struct btf_verifier_env *env, | |
4510 | const struct btf_type *t) | |
4511 | { | |
4512 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
4513 | } | |
4514 | ||
31d0bc81 AM |
4515 | static void btf_datasec_show(const struct btf *btf, |
4516 | const struct btf_type *t, u32 type_id, | |
4517 | void *data, u8 bits_offset, | |
4518 | struct btf_show *show) | |
1dc92851 DB |
4519 | { |
4520 | const struct btf_var_secinfo *vsi; | |
4521 | const struct btf_type *var; | |
4522 | u32 i; | |
4523 | ||
31d0bc81 AM |
4524 | if (!btf_show_start_type(show, t, type_id, data)) |
4525 | return; | |
4526 | ||
4527 | btf_show_type_value(show, "section (\"%s\") = {", | |
4528 | __btf_name_by_offset(btf, t->name_off)); | |
1dc92851 DB |
4529 | for_each_vsi(i, t, vsi) { |
4530 | var = btf_type_by_id(btf, vsi->type); | |
4531 | if (i) | |
31d0bc81 AM |
4532 | btf_show(show, ","); |
4533 | btf_type_ops(var)->show(btf, var, vsi->type, | |
4534 | data + vsi->offset, bits_offset, show); | |
1dc92851 | 4535 | } |
31d0bc81 | 4536 | btf_show_end_type(show); |
1dc92851 DB |
4537 | } |
4538 | ||
4539 | static const struct btf_kind_operations datasec_ops = { | |
4540 | .check_meta = btf_datasec_check_meta, | |
4541 | .resolve = btf_datasec_resolve, | |
4542 | .check_member = btf_df_check_member, | |
4543 | .check_kflag_member = btf_df_check_kflag_member, | |
4544 | .log_details = btf_datasec_log, | |
31d0bc81 | 4545 | .show = btf_datasec_show, |
1dc92851 DB |
4546 | }; |
4547 | ||
b1828f0b IL |
4548 | static s32 btf_float_check_meta(struct btf_verifier_env *env, |
4549 | const struct btf_type *t, | |
4550 | u32 meta_left) | |
4551 | { | |
4552 | if (btf_type_vlen(t)) { | |
4553 | btf_verifier_log_type(env, t, "vlen != 0"); | |
4554 | return -EINVAL; | |
4555 | } | |
4556 | ||
4557 | if (btf_type_kflag(t)) { | |
4558 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4559 | return -EINVAL; | |
4560 | } | |
4561 | ||
4562 | if (t->size != 2 && t->size != 4 && t->size != 8 && t->size != 12 && | |
4563 | t->size != 16) { | |
4564 | btf_verifier_log_type(env, t, "Invalid type_size"); | |
4565 | return -EINVAL; | |
4566 | } | |
4567 | ||
4568 | btf_verifier_log_type(env, t, NULL); | |
4569 | ||
4570 | return 0; | |
4571 | } | |
4572 | ||
4573 | static int btf_float_check_member(struct btf_verifier_env *env, | |
4574 | const struct btf_type *struct_type, | |
4575 | const struct btf_member *member, | |
4576 | const struct btf_type *member_type) | |
4577 | { | |
4578 | u64 start_offset_bytes; | |
4579 | u64 end_offset_bytes; | |
4580 | u64 misalign_bits; | |
4581 | u64 align_bytes; | |
4582 | u64 align_bits; | |
4583 | ||
4584 | /* Different architectures have different alignment requirements, so | |
4585 | * here we check only for the reasonable minimum. This way we ensure | |
4586 | * that types after CO-RE can pass the kernel BTF verifier. | |
4587 | */ | |
4588 | align_bytes = min_t(u64, sizeof(void *), member_type->size); | |
4589 | align_bits = align_bytes * BITS_PER_BYTE; | |
4590 | div64_u64_rem(member->offset, align_bits, &misalign_bits); | |
4591 | if (misalign_bits) { | |
4592 | btf_verifier_log_member(env, struct_type, member, | |
4593 | "Member is not properly aligned"); | |
4594 | return -EINVAL; | |
4595 | } | |
4596 | ||
4597 | start_offset_bytes = member->offset / BITS_PER_BYTE; | |
4598 | end_offset_bytes = start_offset_bytes + member_type->size; | |
4599 | if (end_offset_bytes > struct_type->size) { | |
4600 | btf_verifier_log_member(env, struct_type, member, | |
4601 | "Member exceeds struct_size"); | |
4602 | return -EINVAL; | |
4603 | } | |
4604 | ||
4605 | return 0; | |
4606 | } | |
4607 | ||
4608 | static void btf_float_log(struct btf_verifier_env *env, | |
4609 | const struct btf_type *t) | |
4610 | { | |
4611 | btf_verifier_log(env, "size=%u", t->size); | |
4612 | } | |
4613 | ||
4614 | static const struct btf_kind_operations float_ops = { | |
4615 | .check_meta = btf_float_check_meta, | |
4616 | .resolve = btf_df_resolve, | |
4617 | .check_member = btf_float_check_member, | |
4618 | .check_kflag_member = btf_generic_check_kflag_member, | |
4619 | .log_details = btf_float_log, | |
4620 | .show = btf_df_show, | |
4621 | }; | |
4622 | ||
223f903e | 4623 | static s32 btf_decl_tag_check_meta(struct btf_verifier_env *env, |
b5ea834d YS |
4624 | const struct btf_type *t, |
4625 | u32 meta_left) | |
4626 | { | |
223f903e | 4627 | const struct btf_decl_tag *tag; |
b5ea834d YS |
4628 | u32 meta_needed = sizeof(*tag); |
4629 | s32 component_idx; | |
4630 | const char *value; | |
4631 | ||
4632 | if (meta_left < meta_needed) { | |
4633 | btf_verifier_log_basic(env, t, | |
4634 | "meta_left:%u meta_needed:%u", | |
4635 | meta_left, meta_needed); | |
4636 | return -EINVAL; | |
4637 | } | |
4638 | ||
4639 | value = btf_name_by_offset(env->btf, t->name_off); | |
4640 | if (!value || !value[0]) { | |
4641 | btf_verifier_log_type(env, t, "Invalid value"); | |
4642 | return -EINVAL; | |
4643 | } | |
4644 | ||
4645 | if (btf_type_vlen(t)) { | |
4646 | btf_verifier_log_type(env, t, "vlen != 0"); | |
4647 | return -EINVAL; | |
4648 | } | |
4649 | ||
4650 | if (btf_type_kflag(t)) { | |
4651 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
4652 | return -EINVAL; | |
4653 | } | |
4654 | ||
223f903e | 4655 | component_idx = btf_type_decl_tag(t)->component_idx; |
b5ea834d YS |
4656 | if (component_idx < -1) { |
4657 | btf_verifier_log_type(env, t, "Invalid component_idx"); | |
4658 | return -EINVAL; | |
4659 | } | |
4660 | ||
4661 | btf_verifier_log_type(env, t, NULL); | |
4662 | ||
4663 | return meta_needed; | |
4664 | } | |
4665 | ||
223f903e | 4666 | static int btf_decl_tag_resolve(struct btf_verifier_env *env, |
b5ea834d YS |
4667 | const struct resolve_vertex *v) |
4668 | { | |
4669 | const struct btf_type *next_type; | |
4670 | const struct btf_type *t = v->t; | |
4671 | u32 next_type_id = t->type; | |
4672 | struct btf *btf = env->btf; | |
4673 | s32 component_idx; | |
4674 | u32 vlen; | |
4675 | ||
4676 | next_type = btf_type_by_id(btf, next_type_id); | |
223f903e | 4677 | if (!next_type || !btf_type_is_decl_tag_target(next_type)) { |
b5ea834d YS |
4678 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
4679 | return -EINVAL; | |
4680 | } | |
4681 | ||
4682 | if (!env_type_is_resolve_sink(env, next_type) && | |
4683 | !env_type_is_resolved(env, next_type_id)) | |
4684 | return env_stack_push(env, next_type, next_type_id); | |
4685 | ||
223f903e | 4686 | component_idx = btf_type_decl_tag(t)->component_idx; |
b5ea834d | 4687 | if (component_idx != -1) { |
bd16dee6 | 4688 | if (btf_type_is_var(next_type) || btf_type_is_typedef(next_type)) { |
b5ea834d YS |
4689 | btf_verifier_log_type(env, v->t, "Invalid component_idx"); |
4690 | return -EINVAL; | |
4691 | } | |
4692 | ||
4693 | if (btf_type_is_struct(next_type)) { | |
4694 | vlen = btf_type_vlen(next_type); | |
4695 | } else { | |
4696 | /* next_type should be a function */ | |
4697 | next_type = btf_type_by_id(btf, next_type->type); | |
4698 | vlen = btf_type_vlen(next_type); | |
4699 | } | |
4700 | ||
4701 | if ((u32)component_idx >= vlen) { | |
4702 | btf_verifier_log_type(env, v->t, "Invalid component_idx"); | |
4703 | return -EINVAL; | |
4704 | } | |
4705 | } | |
4706 | ||
4707 | env_stack_pop_resolved(env, next_type_id, 0); | |
4708 | ||
4709 | return 0; | |
4710 | } | |
4711 | ||
223f903e | 4712 | static void btf_decl_tag_log(struct btf_verifier_env *env, const struct btf_type *t) |
b5ea834d YS |
4713 | { |
4714 | btf_verifier_log(env, "type=%u component_idx=%d", t->type, | |
223f903e | 4715 | btf_type_decl_tag(t)->component_idx); |
b5ea834d YS |
4716 | } |
4717 | ||
223f903e YS |
4718 | static const struct btf_kind_operations decl_tag_ops = { |
4719 | .check_meta = btf_decl_tag_check_meta, | |
4720 | .resolve = btf_decl_tag_resolve, | |
b5ea834d YS |
4721 | .check_member = btf_df_check_member, |
4722 | .check_kflag_member = btf_df_check_kflag_member, | |
223f903e | 4723 | .log_details = btf_decl_tag_log, |
b5ea834d YS |
4724 | .show = btf_df_show, |
4725 | }; | |
4726 | ||
2667a262 MKL |
4727 | static int btf_func_proto_check(struct btf_verifier_env *env, |
4728 | const struct btf_type *t) | |
4729 | { | |
4730 | const struct btf_type *ret_type; | |
4731 | const struct btf_param *args; | |
4732 | const struct btf *btf; | |
4733 | u16 nr_args, i; | |
4734 | int err; | |
4735 | ||
4736 | btf = env->btf; | |
4737 | args = (const struct btf_param *)(t + 1); | |
4738 | nr_args = btf_type_vlen(t); | |
4739 | ||
4740 | /* Check func return type which could be "void" (t->type == 0) */ | |
4741 | if (t->type) { | |
4742 | u32 ret_type_id = t->type; | |
4743 | ||
4744 | ret_type = btf_type_by_id(btf, ret_type_id); | |
4745 | if (!ret_type) { | |
4746 | btf_verifier_log_type(env, t, "Invalid return type"); | |
4747 | return -EINVAL; | |
4748 | } | |
4749 | ||
ea68376c SF |
4750 | if (btf_type_is_resolve_source_only(ret_type)) { |
4751 | btf_verifier_log_type(env, t, "Invalid return type"); | |
4752 | return -EINVAL; | |
4753 | } | |
4754 | ||
2667a262 MKL |
4755 | if (btf_type_needs_resolve(ret_type) && |
4756 | !env_type_is_resolved(env, ret_type_id)) { | |
4757 | err = btf_resolve(env, ret_type, ret_type_id); | |
4758 | if (err) | |
4759 | return err; | |
4760 | } | |
4761 | ||
4762 | /* Ensure the return type is a type that has a size */ | |
4763 | if (!btf_type_id_size(btf, &ret_type_id, NULL)) { | |
4764 | btf_verifier_log_type(env, t, "Invalid return type"); | |
4765 | return -EINVAL; | |
4766 | } | |
4767 | } | |
4768 | ||
4769 | if (!nr_args) | |
4770 | return 0; | |
4771 | ||
4772 | /* Last func arg type_id could be 0 if it is a vararg */ | |
4773 | if (!args[nr_args - 1].type) { | |
4774 | if (args[nr_args - 1].name_off) { | |
4775 | btf_verifier_log_type(env, t, "Invalid arg#%u", | |
4776 | nr_args); | |
4777 | return -EINVAL; | |
4778 | } | |
4779 | nr_args--; | |
4780 | } | |
4781 | ||
2667a262 MKL |
4782 | for (i = 0; i < nr_args; i++) { |
4783 | const struct btf_type *arg_type; | |
4784 | u32 arg_type_id; | |
4785 | ||
4786 | arg_type_id = args[i].type; | |
4787 | arg_type = btf_type_by_id(btf, arg_type_id); | |
4788 | if (!arg_type) { | |
4789 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
5bad3587 | 4790 | return -EINVAL; |
2667a262 MKL |
4791 | } |
4792 | ||
f17472d4 SF |
4793 | if (btf_type_is_resolve_source_only(arg_type)) { |
4794 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
4795 | return -EINVAL; | |
4796 | } | |
4797 | ||
2667a262 MKL |
4798 | if (args[i].name_off && |
4799 | (!btf_name_offset_valid(btf, args[i].name_off) || | |
4800 | !btf_name_valid_identifier(btf, args[i].name_off))) { | |
4801 | btf_verifier_log_type(env, t, | |
4802 | "Invalid arg#%u", i + 1); | |
5bad3587 | 4803 | return -EINVAL; |
2667a262 MKL |
4804 | } |
4805 | ||
4806 | if (btf_type_needs_resolve(arg_type) && | |
4807 | !env_type_is_resolved(env, arg_type_id)) { | |
4808 | err = btf_resolve(env, arg_type, arg_type_id); | |
4809 | if (err) | |
5bad3587 | 4810 | return err; |
2667a262 MKL |
4811 | } |
4812 | ||
4813 | if (!btf_type_id_size(btf, &arg_type_id, NULL)) { | |
4814 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
5bad3587 | 4815 | return -EINVAL; |
2667a262 MKL |
4816 | } |
4817 | } | |
4818 | ||
5bad3587 | 4819 | return 0; |
2667a262 MKL |
4820 | } |
4821 | ||
4822 | static int btf_func_check(struct btf_verifier_env *env, | |
4823 | const struct btf_type *t) | |
4824 | { | |
4825 | const struct btf_type *proto_type; | |
4826 | const struct btf_param *args; | |
4827 | const struct btf *btf; | |
4828 | u16 nr_args, i; | |
4829 | ||
4830 | btf = env->btf; | |
4831 | proto_type = btf_type_by_id(btf, t->type); | |
4832 | ||
4833 | if (!proto_type || !btf_type_is_func_proto(proto_type)) { | |
4834 | btf_verifier_log_type(env, t, "Invalid type_id"); | |
4835 | return -EINVAL; | |
4836 | } | |
4837 | ||
4838 | args = (const struct btf_param *)(proto_type + 1); | |
4839 | nr_args = btf_type_vlen(proto_type); | |
4840 | for (i = 0; i < nr_args; i++) { | |
4841 | if (!args[i].name_off && args[i].type) { | |
4842 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
4843 | return -EINVAL; | |
4844 | } | |
4845 | } | |
4846 | ||
4847 | return 0; | |
4848 | } | |
4849 | ||
69b693f0 MKL |
4850 | static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = { |
4851 | [BTF_KIND_INT] = &int_ops, | |
4852 | [BTF_KIND_PTR] = &ptr_ops, | |
4853 | [BTF_KIND_ARRAY] = &array_ops, | |
4854 | [BTF_KIND_STRUCT] = &struct_ops, | |
4855 | [BTF_KIND_UNION] = &struct_ops, | |
4856 | [BTF_KIND_ENUM] = &enum_ops, | |
4857 | [BTF_KIND_FWD] = &fwd_ops, | |
4858 | [BTF_KIND_TYPEDEF] = &modifier_ops, | |
4859 | [BTF_KIND_VOLATILE] = &modifier_ops, | |
4860 | [BTF_KIND_CONST] = &modifier_ops, | |
4861 | [BTF_KIND_RESTRICT] = &modifier_ops, | |
2667a262 MKL |
4862 | [BTF_KIND_FUNC] = &func_ops, |
4863 | [BTF_KIND_FUNC_PROTO] = &func_proto_ops, | |
1dc92851 DB |
4864 | [BTF_KIND_VAR] = &var_ops, |
4865 | [BTF_KIND_DATASEC] = &datasec_ops, | |
b1828f0b | 4866 | [BTF_KIND_FLOAT] = &float_ops, |
223f903e | 4867 | [BTF_KIND_DECL_TAG] = &decl_tag_ops, |
8c42d2fa | 4868 | [BTF_KIND_TYPE_TAG] = &modifier_ops, |
6089fb32 | 4869 | [BTF_KIND_ENUM64] = &enum64_ops, |
69b693f0 MKL |
4870 | }; |
4871 | ||
4872 | static s32 btf_check_meta(struct btf_verifier_env *env, | |
4873 | const struct btf_type *t, | |
4874 | u32 meta_left) | |
4875 | { | |
4876 | u32 saved_meta_left = meta_left; | |
4877 | s32 var_meta_size; | |
4878 | ||
4879 | if (meta_left < sizeof(*t)) { | |
4880 | btf_verifier_log(env, "[%u] meta_left:%u meta_needed:%zu", | |
4881 | env->log_type_id, meta_left, sizeof(*t)); | |
4882 | return -EINVAL; | |
4883 | } | |
4884 | meta_left -= sizeof(*t); | |
4885 | ||
aea2f7b8 MKL |
4886 | if (t->info & ~BTF_INFO_MASK) { |
4887 | btf_verifier_log(env, "[%u] Invalid btf_info:%x", | |
4888 | env->log_type_id, t->info); | |
4889 | return -EINVAL; | |
4890 | } | |
4891 | ||
69b693f0 MKL |
4892 | if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX || |
4893 | BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) { | |
4894 | btf_verifier_log(env, "[%u] Invalid kind:%u", | |
4895 | env->log_type_id, BTF_INFO_KIND(t->info)); | |
4896 | return -EINVAL; | |
4897 | } | |
4898 | ||
fbcf93eb | 4899 | if (!btf_name_offset_valid(env->btf, t->name_off)) { |
69b693f0 | 4900 | btf_verifier_log(env, "[%u] Invalid name_offset:%u", |
fbcf93eb | 4901 | env->log_type_id, t->name_off); |
69b693f0 MKL |
4902 | return -EINVAL; |
4903 | } | |
4904 | ||
4905 | var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left); | |
4906 | if (var_meta_size < 0) | |
4907 | return var_meta_size; | |
4908 | ||
4909 | meta_left -= var_meta_size; | |
4910 | ||
4911 | return saved_meta_left - meta_left; | |
4912 | } | |
4913 | ||
4914 | static int btf_check_all_metas(struct btf_verifier_env *env) | |
4915 | { | |
4916 | struct btf *btf = env->btf; | |
4917 | struct btf_header *hdr; | |
4918 | void *cur, *end; | |
4919 | ||
f80442a4 | 4920 | hdr = &btf->hdr; |
69b693f0 | 4921 | cur = btf->nohdr_data + hdr->type_off; |
4b1c5d91 | 4922 | end = cur + hdr->type_len; |
69b693f0 | 4923 | |
951bb646 | 4924 | env->log_type_id = btf->base_btf ? btf->start_id : 1; |
69b693f0 MKL |
4925 | while (cur < end) { |
4926 | struct btf_type *t = cur; | |
4927 | s32 meta_size; | |
4928 | ||
4929 | meta_size = btf_check_meta(env, t, end - cur); | |
4930 | if (meta_size < 0) | |
4931 | return meta_size; | |
4932 | ||
4933 | btf_add_type(env, t); | |
4934 | cur += meta_size; | |
4935 | env->log_type_id++; | |
4936 | } | |
4937 | ||
4938 | return 0; | |
4939 | } | |
4940 | ||
eb3f595d MKL |
4941 | static bool btf_resolve_valid(struct btf_verifier_env *env, |
4942 | const struct btf_type *t, | |
4943 | u32 type_id) | |
4944 | { | |
4945 | struct btf *btf = env->btf; | |
4946 | ||
4947 | if (!env_type_is_resolved(env, type_id)) | |
4948 | return false; | |
4949 | ||
1dc92851 | 4950 | if (btf_type_is_struct(t) || btf_type_is_datasec(t)) |
951bb646 AN |
4951 | return !btf_resolved_type_id(btf, type_id) && |
4952 | !btf_resolved_type_size(btf, type_id); | |
eb3f595d | 4953 | |
d7e7b42f | 4954 | if (btf_type_is_decl_tag(t) || btf_type_is_func(t)) |
b5ea834d YS |
4955 | return btf_resolved_type_id(btf, type_id) && |
4956 | !btf_resolved_type_size(btf, type_id); | |
4957 | ||
1dc92851 DB |
4958 | if (btf_type_is_modifier(t) || btf_type_is_ptr(t) || |
4959 | btf_type_is_var(t)) { | |
eb3f595d | 4960 | t = btf_type_id_resolve(btf, &type_id); |
1dc92851 DB |
4961 | return t && |
4962 | !btf_type_is_modifier(t) && | |
4963 | !btf_type_is_var(t) && | |
4964 | !btf_type_is_datasec(t); | |
eb3f595d MKL |
4965 | } |
4966 | ||
4967 | if (btf_type_is_array(t)) { | |
4968 | const struct btf_array *array = btf_type_array(t); | |
4969 | const struct btf_type *elem_type; | |
4970 | u32 elem_type_id = array->type; | |
4971 | u32 elem_size; | |
4972 | ||
4973 | elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); | |
4974 | return elem_type && !btf_type_is_modifier(elem_type) && | |
4975 | (array->nelems * elem_size == | |
951bb646 | 4976 | btf_resolved_type_size(btf, type_id)); |
eb3f595d MKL |
4977 | } |
4978 | ||
4979 | return false; | |
4980 | } | |
4981 | ||
2667a262 MKL |
4982 | static int btf_resolve(struct btf_verifier_env *env, |
4983 | const struct btf_type *t, u32 type_id) | |
4984 | { | |
4985 | u32 save_log_type_id = env->log_type_id; | |
4986 | const struct resolve_vertex *v; | |
4987 | int err = 0; | |
4988 | ||
4989 | env->resolve_mode = RESOLVE_TBD; | |
4990 | env_stack_push(env, t, type_id); | |
4991 | while (!err && (v = env_stack_peak(env))) { | |
4992 | env->log_type_id = v->type_id; | |
4993 | err = btf_type_ops(v->t)->resolve(env, v); | |
4994 | } | |
4995 | ||
4996 | env->log_type_id = type_id; | |
4997 | if (err == -E2BIG) { | |
4998 | btf_verifier_log_type(env, t, | |
4999 | "Exceeded max resolving depth:%u", | |
5000 | MAX_RESOLVE_DEPTH); | |
5001 | } else if (err == -EEXIST) { | |
5002 | btf_verifier_log_type(env, t, "Loop detected"); | |
5003 | } | |
5004 | ||
5005 | /* Final sanity check */ | |
5006 | if (!err && !btf_resolve_valid(env, t, type_id)) { | |
5007 | btf_verifier_log_type(env, t, "Invalid resolve state"); | |
5008 | err = -EINVAL; | |
5009 | } | |
5010 | ||
5011 | env->log_type_id = save_log_type_id; | |
5012 | return err; | |
5013 | } | |
5014 | ||
eb3f595d MKL |
5015 | static int btf_check_all_types(struct btf_verifier_env *env) |
5016 | { | |
5017 | struct btf *btf = env->btf; | |
951bb646 AN |
5018 | const struct btf_type *t; |
5019 | u32 type_id, i; | |
eb3f595d MKL |
5020 | int err; |
5021 | ||
5022 | err = env_resolve_init(env); | |
5023 | if (err) | |
5024 | return err; | |
5025 | ||
5026 | env->phase++; | |
951bb646 AN |
5027 | for (i = btf->base_btf ? 0 : 1; i < btf->nr_types; i++) { |
5028 | type_id = btf->start_id + i; | |
5029 | t = btf_type_by_id(btf, type_id); | |
eb3f595d MKL |
5030 | |
5031 | env->log_type_id = type_id; | |
5032 | if (btf_type_needs_resolve(t) && | |
5033 | !env_type_is_resolved(env, type_id)) { | |
5034 | err = btf_resolve(env, t, type_id); | |
5035 | if (err) | |
5036 | return err; | |
5037 | } | |
5038 | ||
2667a262 MKL |
5039 | if (btf_type_is_func_proto(t)) { |
5040 | err = btf_func_proto_check(env, t); | |
5041 | if (err) | |
5042 | return err; | |
5043 | } | |
eb3f595d MKL |
5044 | } |
5045 | ||
5046 | return 0; | |
5047 | } | |
5048 | ||
69b693f0 MKL |
5049 | static int btf_parse_type_sec(struct btf_verifier_env *env) |
5050 | { | |
f80442a4 | 5051 | const struct btf_header *hdr = &env->btf->hdr; |
eb3f595d MKL |
5052 | int err; |
5053 | ||
f80442a4 MKL |
5054 | /* Type section must align to 4 bytes */ |
5055 | if (hdr->type_off & (sizeof(u32) - 1)) { | |
5056 | btf_verifier_log(env, "Unaligned type_off"); | |
5057 | return -EINVAL; | |
5058 | } | |
5059 | ||
951bb646 | 5060 | if (!env->btf->base_btf && !hdr->type_len) { |
f80442a4 MKL |
5061 | btf_verifier_log(env, "No type found"); |
5062 | return -EINVAL; | |
5063 | } | |
5064 | ||
eb3f595d MKL |
5065 | err = btf_check_all_metas(env); |
5066 | if (err) | |
5067 | return err; | |
5068 | ||
5069 | return btf_check_all_types(env); | |
69b693f0 MKL |
5070 | } |
5071 | ||
5072 | static int btf_parse_str_sec(struct btf_verifier_env *env) | |
5073 | { | |
5074 | const struct btf_header *hdr; | |
5075 | struct btf *btf = env->btf; | |
5076 | const char *start, *end; | |
5077 | ||
f80442a4 | 5078 | hdr = &btf->hdr; |
69b693f0 MKL |
5079 | start = btf->nohdr_data + hdr->str_off; |
5080 | end = start + hdr->str_len; | |
5081 | ||
f80442a4 MKL |
5082 | if (end != btf->data + btf->data_size) { |
5083 | btf_verifier_log(env, "String section is not at the end"); | |
5084 | return -EINVAL; | |
5085 | } | |
5086 | ||
951bb646 AN |
5087 | btf->strings = start; |
5088 | ||
5089 | if (btf->base_btf && !hdr->str_len) | |
5090 | return 0; | |
5091 | if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET || end[-1]) { | |
5092 | btf_verifier_log(env, "Invalid string section"); | |
5093 | return -EINVAL; | |
5094 | } | |
5095 | if (!btf->base_btf && start[0]) { | |
69b693f0 MKL |
5096 | btf_verifier_log(env, "Invalid string section"); |
5097 | return -EINVAL; | |
5098 | } | |
69b693f0 MKL |
5099 | |
5100 | return 0; | |
5101 | } | |
5102 | ||
f80442a4 MKL |
5103 | static const size_t btf_sec_info_offset[] = { |
5104 | offsetof(struct btf_header, type_off), | |
5105 | offsetof(struct btf_header, str_off), | |
5106 | }; | |
5107 | ||
5108 | static int btf_sec_info_cmp(const void *a, const void *b) | |
69b693f0 | 5109 | { |
f80442a4 MKL |
5110 | const struct btf_sec_info *x = a; |
5111 | const struct btf_sec_info *y = b; | |
5112 | ||
5113 | return (int)(x->off - y->off) ? : (int)(x->len - y->len); | |
5114 | } | |
5115 | ||
5116 | static int btf_check_sec_info(struct btf_verifier_env *env, | |
5117 | u32 btf_data_size) | |
5118 | { | |
a2889a4c | 5119 | struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)]; |
f80442a4 | 5120 | u32 total, expected_total, i; |
69b693f0 | 5121 | const struct btf_header *hdr; |
f80442a4 MKL |
5122 | const struct btf *btf; |
5123 | ||
5124 | btf = env->btf; | |
5125 | hdr = &btf->hdr; | |
5126 | ||
5127 | /* Populate the secs from hdr */ | |
a2889a4c | 5128 | for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) |
f80442a4 MKL |
5129 | secs[i] = *(struct btf_sec_info *)((void *)hdr + |
5130 | btf_sec_info_offset[i]); | |
5131 | ||
a2889a4c MKL |
5132 | sort(secs, ARRAY_SIZE(btf_sec_info_offset), |
5133 | sizeof(struct btf_sec_info), btf_sec_info_cmp, NULL); | |
f80442a4 MKL |
5134 | |
5135 | /* Check for gaps and overlap among sections */ | |
5136 | total = 0; | |
5137 | expected_total = btf_data_size - hdr->hdr_len; | |
a2889a4c | 5138 | for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) { |
f80442a4 MKL |
5139 | if (expected_total < secs[i].off) { |
5140 | btf_verifier_log(env, "Invalid section offset"); | |
5141 | return -EINVAL; | |
5142 | } | |
5143 | if (total < secs[i].off) { | |
5144 | /* gap */ | |
5145 | btf_verifier_log(env, "Unsupported section found"); | |
5146 | return -EINVAL; | |
5147 | } | |
5148 | if (total > secs[i].off) { | |
5149 | btf_verifier_log(env, "Section overlap found"); | |
5150 | return -EINVAL; | |
5151 | } | |
5152 | if (expected_total - total < secs[i].len) { | |
5153 | btf_verifier_log(env, | |
5154 | "Total section length too long"); | |
5155 | return -EINVAL; | |
5156 | } | |
5157 | total += secs[i].len; | |
5158 | } | |
5159 | ||
5160 | /* There is data other than hdr and known sections */ | |
5161 | if (expected_total != total) { | |
5162 | btf_verifier_log(env, "Unsupported section found"); | |
5163 | return -EINVAL; | |
5164 | } | |
5165 | ||
5166 | return 0; | |
5167 | } | |
5168 | ||
4a6998af | 5169 | static int btf_parse_hdr(struct btf_verifier_env *env) |
f80442a4 | 5170 | { |
4a6998af | 5171 | u32 hdr_len, hdr_copy, btf_data_size; |
f80442a4 | 5172 | const struct btf_header *hdr; |
f80442a4 | 5173 | struct btf *btf; |
69b693f0 | 5174 | |
f80442a4 | 5175 | btf = env->btf; |
4a6998af | 5176 | btf_data_size = btf->data_size; |
f80442a4 | 5177 | |
583669ab | 5178 | if (btf_data_size < offsetofend(struct btf_header, hdr_len)) { |
f80442a4 MKL |
5179 | btf_verifier_log(env, "hdr_len not found"); |
5180 | return -EINVAL; | |
5181 | } | |
5182 | ||
4a6998af ML |
5183 | hdr = btf->data; |
5184 | hdr_len = hdr->hdr_len; | |
f80442a4 | 5185 | if (btf_data_size < hdr_len) { |
69b693f0 MKL |
5186 | btf_verifier_log(env, "btf_header not found"); |
5187 | return -EINVAL; | |
5188 | } | |
5189 | ||
4a6998af ML |
5190 | /* Ensure the unsupported header fields are zero */ |
5191 | if (hdr_len > sizeof(btf->hdr)) { | |
5192 | u8 *expected_zero = btf->data + sizeof(btf->hdr); | |
5193 | u8 *end = btf->data + hdr_len; | |
5194 | ||
5195 | for (; expected_zero < end; expected_zero++) { | |
5196 | if (*expected_zero) { | |
5197 | btf_verifier_log(env, "Unsupported btf_header"); | |
5198 | return -E2BIG; | |
5199 | } | |
5200 | } | |
f80442a4 MKL |
5201 | } |
5202 | ||
5203 | hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr)); | |
4a6998af | 5204 | memcpy(&btf->hdr, btf->data, hdr_copy); |
f80442a4 MKL |
5205 | |
5206 | hdr = &btf->hdr; | |
5207 | ||
5208 | btf_verifier_log_hdr(env, btf_data_size); | |
69b693f0 | 5209 | |
69b693f0 MKL |
5210 | if (hdr->magic != BTF_MAGIC) { |
5211 | btf_verifier_log(env, "Invalid magic"); | |
5212 | return -EINVAL; | |
5213 | } | |
5214 | ||
5215 | if (hdr->version != BTF_VERSION) { | |
5216 | btf_verifier_log(env, "Unsupported version"); | |
5217 | return -ENOTSUPP; | |
5218 | } | |
5219 | ||
5220 | if (hdr->flags) { | |
5221 | btf_verifier_log(env, "Unsupported flags"); | |
5222 | return -ENOTSUPP; | |
5223 | } | |
5224 | ||
bcc5e616 | 5225 | if (!btf->base_btf && btf_data_size == hdr->hdr_len) { |
69b693f0 MKL |
5226 | btf_verifier_log(env, "No data"); |
5227 | return -EINVAL; | |
5228 | } | |
5229 | ||
3a74904c | 5230 | return btf_check_sec_info(env, btf_data_size); |
69b693f0 MKL |
5231 | } |
5232 | ||
8ffa5cc1 KKD |
5233 | static const char *alloc_obj_fields[] = { |
5234 | "bpf_spin_lock", | |
5235 | "bpf_list_head", | |
5236 | "bpf_list_node", | |
5237 | }; | |
5238 | ||
5239 | static struct btf_struct_metas * | |
5240 | btf_parse_struct_metas(struct bpf_verifier_log *log, struct btf *btf) | |
5241 | { | |
5242 | union { | |
5243 | struct btf_id_set set; | |
5244 | struct { | |
5245 | u32 _cnt; | |
5246 | u32 _ids[ARRAY_SIZE(alloc_obj_fields)]; | |
5247 | } _arr; | |
5248 | } aof; | |
5249 | struct btf_struct_metas *tab = NULL; | |
5250 | int i, n, id, ret; | |
5251 | ||
5252 | BUILD_BUG_ON(offsetof(struct btf_id_set, cnt) != 0); | |
5253 | BUILD_BUG_ON(sizeof(struct btf_id_set) != sizeof(u32)); | |
5254 | ||
5255 | memset(&aof, 0, sizeof(aof)); | |
5256 | for (i = 0; i < ARRAY_SIZE(alloc_obj_fields); i++) { | |
5257 | /* Try to find whether this special type exists in user BTF, and | |
5258 | * if so remember its ID so we can easily find it among members | |
5259 | * of structs that we iterate in the next loop. | |
5260 | */ | |
5261 | id = btf_find_by_name_kind(btf, alloc_obj_fields[i], BTF_KIND_STRUCT); | |
5262 | if (id < 0) | |
5263 | continue; | |
5264 | aof.set.ids[aof.set.cnt++] = id; | |
5265 | } | |
5266 | ||
5267 | if (!aof.set.cnt) | |
5268 | return NULL; | |
5269 | sort(&aof.set.ids, aof.set.cnt, sizeof(aof.set.ids[0]), btf_id_cmp_func, NULL); | |
5270 | ||
5271 | n = btf_nr_types(btf); | |
5272 | for (i = 1; i < n; i++) { | |
5273 | struct btf_struct_metas *new_tab; | |
5274 | const struct btf_member *member; | |
5275 | struct btf_field_offs *foffs; | |
5276 | struct btf_struct_meta *type; | |
5277 | struct btf_record *record; | |
5278 | const struct btf_type *t; | |
5279 | int j, tab_cnt; | |
5280 | ||
5281 | t = btf_type_by_id(btf, i); | |
5282 | if (!t) { | |
5283 | ret = -EINVAL; | |
5284 | goto free; | |
5285 | } | |
5286 | if (!__btf_type_is_struct(t)) | |
5287 | continue; | |
5288 | ||
5289 | cond_resched(); | |
5290 | ||
5291 | for_each_member(j, t, member) { | |
5292 | if (btf_id_set_contains(&aof.set, member->type)) | |
5293 | goto parse; | |
5294 | } | |
5295 | continue; | |
5296 | parse: | |
5297 | tab_cnt = tab ? tab->cnt : 0; | |
5298 | new_tab = krealloc(tab, offsetof(struct btf_struct_metas, types[tab_cnt + 1]), | |
5299 | GFP_KERNEL | __GFP_NOWARN); | |
5300 | if (!new_tab) { | |
5301 | ret = -ENOMEM; | |
5302 | goto free; | |
5303 | } | |
5304 | if (!tab) | |
5305 | new_tab->cnt = 0; | |
5306 | tab = new_tab; | |
5307 | ||
5308 | type = &tab->types[tab->cnt]; | |
5309 | type->btf_id = i; | |
5310 | record = btf_parse_fields(btf, t, BPF_SPIN_LOCK | BPF_LIST_HEAD | BPF_LIST_NODE, t->size); | |
5311 | /* The record cannot be unset, treat it as an error if so */ | |
5312 | if (IS_ERR_OR_NULL(record)) { | |
5313 | ret = PTR_ERR_OR_ZERO(record) ?: -EFAULT; | |
5314 | goto free; | |
5315 | } | |
5316 | foffs = btf_parse_field_offs(record); | |
5317 | /* We need the field_offs to be valid for a valid record, | |
5318 | * either both should be set or both should be unset. | |
5319 | */ | |
5320 | if (IS_ERR_OR_NULL(foffs)) { | |
5321 | btf_record_free(record); | |
5322 | ret = -EFAULT; | |
5323 | goto free; | |
5324 | } | |
5325 | type->record = record; | |
5326 | type->field_offs = foffs; | |
5327 | tab->cnt++; | |
5328 | } | |
5329 | return tab; | |
5330 | free: | |
5331 | btf_struct_metas_free(tab); | |
5332 | return ERR_PTR(ret); | |
5333 | } | |
5334 | ||
5335 | struct btf_struct_meta *btf_find_struct_meta(const struct btf *btf, u32 btf_id) | |
5336 | { | |
5337 | struct btf_struct_metas *tab; | |
5338 | ||
5339 | BUILD_BUG_ON(offsetof(struct btf_struct_meta, btf_id) != 0); | |
5340 | tab = btf->struct_meta_tab; | |
5341 | if (!tab) | |
5342 | return NULL; | |
5343 | return bsearch(&btf_id, tab->types, tab->cnt, sizeof(tab->types[0]), btf_id_cmp_func); | |
5344 | } | |
5345 | ||
eb596b09 KKD |
5346 | static int btf_check_type_tags(struct btf_verifier_env *env, |
5347 | struct btf *btf, int start_id) | |
5348 | { | |
5349 | int i, n, good_id = start_id - 1; | |
5350 | bool in_tags; | |
5351 | ||
5352 | n = btf_nr_types(btf); | |
5353 | for (i = start_id; i < n; i++) { | |
5354 | const struct btf_type *t; | |
d1a374a1 | 5355 | int chain_limit = 32; |
eb596b09 KKD |
5356 | u32 cur_id = i; |
5357 | ||
5358 | t = btf_type_by_id(btf, i); | |
5359 | if (!t) | |
5360 | return -EINVAL; | |
5361 | if (!btf_type_is_modifier(t)) | |
5362 | continue; | |
5363 | ||
5364 | cond_resched(); | |
5365 | ||
5366 | in_tags = btf_type_is_type_tag(t); | |
5367 | while (btf_type_is_modifier(t)) { | |
d1a374a1 KKD |
5368 | if (!chain_limit--) { |
5369 | btf_verifier_log(env, "Max chain length or cycle detected"); | |
5370 | return -ELOOP; | |
5371 | } | |
eb596b09 KKD |
5372 | if (btf_type_is_type_tag(t)) { |
5373 | if (!in_tags) { | |
5374 | btf_verifier_log(env, "Type tags don't precede modifiers"); | |
5375 | return -EINVAL; | |
5376 | } | |
5377 | } else if (in_tags) { | |
5378 | in_tags = false; | |
5379 | } | |
5380 | if (cur_id <= good_id) | |
5381 | break; | |
5382 | /* Move to next type */ | |
5383 | cur_id = t->type; | |
5384 | t = btf_type_by_id(btf, cur_id); | |
5385 | if (!t) | |
5386 | return -EINVAL; | |
5387 | } | |
5388 | good_id = i; | |
5389 | } | |
5390 | return 0; | |
5391 | } | |
5392 | ||
c571bd75 | 5393 | static struct btf *btf_parse(bpfptr_t btf_data, u32 btf_data_size, |
69b693f0 MKL |
5394 | u32 log_level, char __user *log_ubuf, u32 log_size) |
5395 | { | |
8ffa5cc1 | 5396 | struct btf_struct_metas *struct_meta_tab; |
69b693f0 MKL |
5397 | struct btf_verifier_env *env = NULL; |
5398 | struct bpf_verifier_log *log; | |
5399 | struct btf *btf = NULL; | |
5400 | u8 *data; | |
5401 | int err; | |
5402 | ||
5403 | if (btf_data_size > BTF_MAX_SIZE) | |
5404 | return ERR_PTR(-E2BIG); | |
5405 | ||
5406 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
5407 | if (!env) | |
5408 | return ERR_PTR(-ENOMEM); | |
5409 | ||
5410 | log = &env->log; | |
5411 | if (log_level || log_ubuf || log_size) { | |
5412 | /* user requested verbose verifier output | |
5413 | * and supplied buffer to store the verification trace | |
5414 | */ | |
5415 | log->level = log_level; | |
5416 | log->ubuf = log_ubuf; | |
5417 | log->len_total = log_size; | |
5418 | ||
5419 | /* log attributes have to be sane */ | |
866de407 | 5420 | if (!bpf_verifier_log_attr_valid(log)) { |
69b693f0 MKL |
5421 | err = -EINVAL; |
5422 | goto errout; | |
5423 | } | |
5424 | } | |
5425 | ||
5426 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
5427 | if (!btf) { | |
5428 | err = -ENOMEM; | |
5429 | goto errout; | |
5430 | } | |
f80442a4 MKL |
5431 | env->btf = btf; |
5432 | ||
69b693f0 MKL |
5433 | data = kvmalloc(btf_data_size, GFP_KERNEL | __GFP_NOWARN); |
5434 | if (!data) { | |
5435 | err = -ENOMEM; | |
5436 | goto errout; | |
5437 | } | |
5438 | ||
5439 | btf->data = data; | |
5440 | btf->data_size = btf_data_size; | |
5441 | ||
c571bd75 | 5442 | if (copy_from_bpfptr(data, btf_data, btf_data_size)) { |
69b693f0 MKL |
5443 | err = -EFAULT; |
5444 | goto errout; | |
5445 | } | |
5446 | ||
4a6998af ML |
5447 | err = btf_parse_hdr(env); |
5448 | if (err) | |
5449 | goto errout; | |
5450 | ||
5451 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
5452 | ||
69b693f0 MKL |
5453 | err = btf_parse_str_sec(env); |
5454 | if (err) | |
5455 | goto errout; | |
5456 | ||
5457 | err = btf_parse_type_sec(env); | |
5458 | if (err) | |
5459 | goto errout; | |
5460 | ||
eb596b09 KKD |
5461 | err = btf_check_type_tags(env, btf, 1); |
5462 | if (err) | |
5463 | goto errout; | |
5464 | ||
8ffa5cc1 KKD |
5465 | struct_meta_tab = btf_parse_struct_metas(log, btf); |
5466 | if (IS_ERR(struct_meta_tab)) { | |
5467 | err = PTR_ERR(struct_meta_tab); | |
5468 | goto errout; | |
5469 | } | |
5470 | btf->struct_meta_tab = struct_meta_tab; | |
5471 | ||
865ce09a KKD |
5472 | if (struct_meta_tab) { |
5473 | int i; | |
5474 | ||
5475 | for (i = 0; i < struct_meta_tab->cnt; i++) { | |
5476 | err = btf_check_and_fixup_fields(btf, struct_meta_tab->types[i].record); | |
5477 | if (err < 0) | |
5478 | goto errout_meta; | |
5479 | } | |
5480 | } | |
5481 | ||
f80442a4 | 5482 | if (log->level && bpf_verifier_log_full(log)) { |
69b693f0 | 5483 | err = -ENOSPC; |
8ffa5cc1 | 5484 | goto errout_meta; |
69b693f0 MKL |
5485 | } |
5486 | ||
f80442a4 MKL |
5487 | btf_verifier_env_free(env); |
5488 | refcount_set(&btf->refcnt, 1); | |
5489 | return btf; | |
69b693f0 | 5490 | |
8ffa5cc1 KKD |
5491 | errout_meta: |
5492 | btf_free_struct_meta_tab(btf); | |
69b693f0 MKL |
5493 | errout: |
5494 | btf_verifier_env_free(env); | |
5495 | if (btf) | |
5496 | btf_free(btf); | |
5497 | return ERR_PTR(err); | |
5498 | } | |
b00b8dae | 5499 | |
90ceddcb FS |
5500 | extern char __weak __start_BTF[]; |
5501 | extern char __weak __stop_BTF[]; | |
91cc1a99 AS |
5502 | extern struct btf *btf_vmlinux; |
5503 | ||
5504 | #define BPF_MAP_TYPE(_id, _ops) | |
f2e10bff | 5505 | #define BPF_LINK_TYPE(_id, _name) |
91cc1a99 AS |
5506 | static union { |
5507 | struct bpf_ctx_convert { | |
5508 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
5509 | prog_ctx_type _id##_prog; \ | |
5510 | kern_ctx_type _id##_kern; | |
5511 | #include <linux/bpf_types.h> | |
5512 | #undef BPF_PROG_TYPE | |
5513 | } *__t; | |
5514 | /* 't' is written once under lock. Read many times. */ | |
5515 | const struct btf_type *t; | |
5516 | } bpf_ctx_convert; | |
5517 | enum { | |
5518 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
5519 | __ctx_convert##_id, | |
5520 | #include <linux/bpf_types.h> | |
5521 | #undef BPF_PROG_TYPE | |
ce27709b | 5522 | __ctx_convert_unused, /* to avoid empty enum in extreme .config */ |
91cc1a99 AS |
5523 | }; |
5524 | static u8 bpf_ctx_convert_map[] = { | |
5525 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
5526 | [_id] = __ctx_convert##_id, | |
5527 | #include <linux/bpf_types.h> | |
5528 | #undef BPF_PROG_TYPE | |
4c80c7bc | 5529 | 0, /* avoid empty array */ |
91cc1a99 AS |
5530 | }; |
5531 | #undef BPF_MAP_TYPE | |
f2e10bff | 5532 | #undef BPF_LINK_TYPE |
91cc1a99 | 5533 | |
00b85860 | 5534 | const struct btf_member * |
34747c41 | 5535 | btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf, |
51c39bb1 AS |
5536 | const struct btf_type *t, enum bpf_prog_type prog_type, |
5537 | int arg) | |
91cc1a99 AS |
5538 | { |
5539 | const struct btf_type *conv_struct; | |
5540 | const struct btf_type *ctx_struct; | |
5541 | const struct btf_member *ctx_type; | |
5542 | const char *tname, *ctx_tname; | |
5543 | ||
5544 | conv_struct = bpf_ctx_convert.t; | |
5545 | if (!conv_struct) { | |
5546 | bpf_log(log, "btf_vmlinux is malformed\n"); | |
5547 | return NULL; | |
5548 | } | |
5549 | t = btf_type_by_id(btf, t->type); | |
5550 | while (btf_type_is_modifier(t)) | |
5551 | t = btf_type_by_id(btf, t->type); | |
5552 | if (!btf_type_is_struct(t)) { | |
5553 | /* Only pointer to struct is supported for now. | |
5554 | * That means that BPF_PROG_TYPE_TRACEPOINT with BTF | |
5555 | * is not supported yet. | |
5556 | * BPF_PROG_TYPE_RAW_TRACEPOINT is fine. | |
5557 | */ | |
91cc1a99 AS |
5558 | return NULL; |
5559 | } | |
5560 | tname = btf_name_by_offset(btf, t->name_off); | |
5561 | if (!tname) { | |
51c39bb1 | 5562 | bpf_log(log, "arg#%d struct doesn't have a name\n", arg); |
91cc1a99 AS |
5563 | return NULL; |
5564 | } | |
5565 | /* prog_type is valid bpf program type. No need for bounds check. */ | |
5566 | ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2; | |
5567 | /* ctx_struct is a pointer to prog_ctx_type in vmlinux. | |
5568 | * Like 'struct __sk_buff' | |
5569 | */ | |
5570 | ctx_struct = btf_type_by_id(btf_vmlinux, ctx_type->type); | |
5571 | if (!ctx_struct) | |
5572 | /* should not happen */ | |
5573 | return NULL; | |
5574 | ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_struct->name_off); | |
5575 | if (!ctx_tname) { | |
5576 | /* should not happen */ | |
5577 | bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n"); | |
5578 | return NULL; | |
5579 | } | |
5580 | /* only compare that prog's ctx type name is the same as | |
5581 | * kernel expects. No need to compare field by field. | |
5582 | * It's ok for bpf prog to do: | |
5583 | * struct __sk_buff {}; | |
5584 | * int socket_filter_bpf_prog(struct __sk_buff *skb) | |
5585 | * { // no fields of skb are ever used } | |
5586 | */ | |
5587 | if (strcmp(ctx_tname, tname)) | |
5588 | return NULL; | |
5589 | return ctx_type; | |
5590 | } | |
8580ac94 | 5591 | |
5b92a28a AS |
5592 | static int btf_translate_to_vmlinux(struct bpf_verifier_log *log, |
5593 | struct btf *btf, | |
5594 | const struct btf_type *t, | |
51c39bb1 AS |
5595 | enum bpf_prog_type prog_type, |
5596 | int arg) | |
5b92a28a AS |
5597 | { |
5598 | const struct btf_member *prog_ctx_type, *kern_ctx_type; | |
5599 | ||
51c39bb1 | 5600 | prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type, arg); |
5b92a28a AS |
5601 | if (!prog_ctx_type) |
5602 | return -ENOENT; | |
5603 | kern_ctx_type = prog_ctx_type + 1; | |
5604 | return kern_ctx_type->type; | |
5605 | } | |
5606 | ||
fd264ca0 YS |
5607 | int get_kern_ctx_btf_id(struct bpf_verifier_log *log, enum bpf_prog_type prog_type) |
5608 | { | |
5609 | const struct btf_member *kctx_member; | |
5610 | const struct btf_type *conv_struct; | |
5611 | const struct btf_type *kctx_type; | |
5612 | u32 kctx_type_id; | |
5613 | ||
5614 | conv_struct = bpf_ctx_convert.t; | |
5615 | /* get member for kernel ctx type */ | |
5616 | kctx_member = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2 + 1; | |
5617 | kctx_type_id = kctx_member->type; | |
5618 | kctx_type = btf_type_by_id(btf_vmlinux, kctx_type_id); | |
5619 | if (!btf_type_is_struct(kctx_type)) { | |
5620 | bpf_log(log, "kern ctx type id %u is not a struct\n", kctx_type_id); | |
5621 | return -EINVAL; | |
5622 | } | |
5623 | ||
5624 | return kctx_type_id; | |
5625 | } | |
5626 | ||
49f4e672 JO |
5627 | BTF_ID_LIST(bpf_ctx_convert_btf_id) |
5628 | BTF_ID(struct, bpf_ctx_convert) | |
5629 | ||
8580ac94 AS |
5630 | struct btf *btf_parse_vmlinux(void) |
5631 | { | |
5632 | struct btf_verifier_env *env = NULL; | |
5633 | struct bpf_verifier_log *log; | |
5634 | struct btf *btf = NULL; | |
49f4e672 | 5635 | int err; |
8580ac94 AS |
5636 | |
5637 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
5638 | if (!env) | |
5639 | return ERR_PTR(-ENOMEM); | |
5640 | ||
5641 | log = &env->log; | |
5642 | log->level = BPF_LOG_KERNEL; | |
5643 | ||
5644 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
5645 | if (!btf) { | |
5646 | err = -ENOMEM; | |
5647 | goto errout; | |
5648 | } | |
5649 | env->btf = btf; | |
5650 | ||
90ceddcb FS |
5651 | btf->data = __start_BTF; |
5652 | btf->data_size = __stop_BTF - __start_BTF; | |
53297220 AN |
5653 | btf->kernel_btf = true; |
5654 | snprintf(btf->name, sizeof(btf->name), "vmlinux"); | |
8580ac94 AS |
5655 | |
5656 | err = btf_parse_hdr(env); | |
5657 | if (err) | |
5658 | goto errout; | |
5659 | ||
5660 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
5661 | ||
5662 | err = btf_parse_str_sec(env); | |
5663 | if (err) | |
5664 | goto errout; | |
5665 | ||
5666 | err = btf_check_all_metas(env); | |
5667 | if (err) | |
5668 | goto errout; | |
5669 | ||
eb596b09 KKD |
5670 | err = btf_check_type_tags(env, btf, 1); |
5671 | if (err) | |
5672 | goto errout; | |
5673 | ||
a2d0d62f | 5674 | /* btf_parse_vmlinux() runs under bpf_verifier_lock */ |
49f4e672 | 5675 | bpf_ctx_convert.t = btf_type_by_id(btf, bpf_ctx_convert_btf_id[0]); |
91cc1a99 | 5676 | |
d3e42bb0 | 5677 | bpf_struct_ops_init(btf, log); |
27ae7997 | 5678 | |
8580ac94 | 5679 | refcount_set(&btf->refcnt, 1); |
53297220 AN |
5680 | |
5681 | err = btf_alloc_id(btf); | |
5682 | if (err) | |
5683 | goto errout; | |
5684 | ||
5685 | btf_verifier_env_free(env); | |
8580ac94 AS |
5686 | return btf; |
5687 | ||
5688 | errout: | |
5689 | btf_verifier_env_free(env); | |
5690 | if (btf) { | |
5691 | kvfree(btf->types); | |
5692 | kfree(btf); | |
5693 | } | |
5694 | return ERR_PTR(err); | |
5695 | } | |
5696 | ||
7112d127 AN |
5697 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
5698 | ||
36e68442 AN |
5699 | static struct btf *btf_parse_module(const char *module_name, const void *data, unsigned int data_size) |
5700 | { | |
5701 | struct btf_verifier_env *env = NULL; | |
5702 | struct bpf_verifier_log *log; | |
5703 | struct btf *btf = NULL, *base_btf; | |
5704 | int err; | |
5705 | ||
5706 | base_btf = bpf_get_btf_vmlinux(); | |
5707 | if (IS_ERR(base_btf)) | |
5708 | return base_btf; | |
5709 | if (!base_btf) | |
5710 | return ERR_PTR(-EINVAL); | |
5711 | ||
5712 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
5713 | if (!env) | |
5714 | return ERR_PTR(-ENOMEM); | |
5715 | ||
5716 | log = &env->log; | |
5717 | log->level = BPF_LOG_KERNEL; | |
5718 | ||
5719 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
5720 | if (!btf) { | |
5721 | err = -ENOMEM; | |
5722 | goto errout; | |
5723 | } | |
5724 | env->btf = btf; | |
5725 | ||
5726 | btf->base_btf = base_btf; | |
5727 | btf->start_id = base_btf->nr_types; | |
5728 | btf->start_str_off = base_btf->hdr.str_len; | |
5729 | btf->kernel_btf = true; | |
5730 | snprintf(btf->name, sizeof(btf->name), "%s", module_name); | |
5731 | ||
5732 | btf->data = kvmalloc(data_size, GFP_KERNEL | __GFP_NOWARN); | |
5733 | if (!btf->data) { | |
5734 | err = -ENOMEM; | |
5735 | goto errout; | |
5736 | } | |
5737 | memcpy(btf->data, data, data_size); | |
5738 | btf->data_size = data_size; | |
5739 | ||
5740 | err = btf_parse_hdr(env); | |
5741 | if (err) | |
5742 | goto errout; | |
5743 | ||
5744 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
5745 | ||
5746 | err = btf_parse_str_sec(env); | |
5747 | if (err) | |
5748 | goto errout; | |
5749 | ||
5750 | err = btf_check_all_metas(env); | |
5751 | if (err) | |
5752 | goto errout; | |
5753 | ||
eb596b09 KKD |
5754 | err = btf_check_type_tags(env, btf, btf_nr_types(base_btf)); |
5755 | if (err) | |
5756 | goto errout; | |
5757 | ||
36e68442 AN |
5758 | btf_verifier_env_free(env); |
5759 | refcount_set(&btf->refcnt, 1); | |
5760 | return btf; | |
5761 | ||
5762 | errout: | |
5763 | btf_verifier_env_free(env); | |
5764 | if (btf) { | |
5765 | kvfree(btf->data); | |
5766 | kvfree(btf->types); | |
5767 | kfree(btf); | |
5768 | } | |
5769 | return ERR_PTR(err); | |
5770 | } | |
5771 | ||
7112d127 AN |
5772 | #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */ |
5773 | ||
5b92a28a AS |
5774 | struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog) |
5775 | { | |
3aac1ead | 5776 | struct bpf_prog *tgt_prog = prog->aux->dst_prog; |
5b92a28a | 5777 | |
22dc4a0f | 5778 | if (tgt_prog) |
5b92a28a | 5779 | return tgt_prog->aux->btf; |
22dc4a0f AN |
5780 | else |
5781 | return prog->aux->attach_btf; | |
5b92a28a AS |
5782 | } |
5783 | ||
bb6728d7 | 5784 | static bool is_int_ptr(struct btf *btf, const struct btf_type *t) |
84ad7a7a JO |
5785 | { |
5786 | /* t comes in already as a pointer */ | |
5787 | t = btf_type_by_id(btf, t->type); | |
5788 | ||
5789 | /* allow const */ | |
5790 | if (BTF_INFO_KIND(t->info) == BTF_KIND_CONST) | |
5791 | t = btf_type_by_id(btf, t->type); | |
5792 | ||
bb6728d7 | 5793 | return btf_type_is_int(t); |
84ad7a7a JO |
5794 | } |
5795 | ||
720e6a43 YS |
5796 | static u32 get_ctx_arg_idx(struct btf *btf, const struct btf_type *func_proto, |
5797 | int off) | |
5798 | { | |
5799 | const struct btf_param *args; | |
5800 | const struct btf_type *t; | |
5801 | u32 offset = 0, nr_args; | |
5802 | int i; | |
5803 | ||
5804 | if (!func_proto) | |
5805 | return off / 8; | |
5806 | ||
5807 | nr_args = btf_type_vlen(func_proto); | |
5808 | args = (const struct btf_param *)(func_proto + 1); | |
5809 | for (i = 0; i < nr_args; i++) { | |
5810 | t = btf_type_skip_modifiers(btf, args[i].type, NULL); | |
5811 | offset += btf_type_is_ptr(t) ? 8 : roundup(t->size, 8); | |
5812 | if (off < offset) | |
5813 | return i; | |
5814 | } | |
5815 | ||
5816 | t = btf_type_skip_modifiers(btf, func_proto->type, NULL); | |
5817 | offset += btf_type_is_ptr(t) ? 8 : roundup(t->size, 8); | |
5818 | if (off < offset) | |
5819 | return nr_args; | |
5820 | ||
5821 | return nr_args + 1; | |
5822 | } | |
5823 | ||
3f00c523 DV |
5824 | static bool prog_type_args_trusted(enum bpf_prog_type prog_type) |
5825 | { | |
5826 | return prog_type == BPF_PROG_TYPE_TRACING || prog_type == BPF_PROG_TYPE_STRUCT_OPS; | |
5827 | } | |
5828 | ||
9e15db66 AS |
5829 | bool btf_ctx_access(int off, int size, enum bpf_access_type type, |
5830 | const struct bpf_prog *prog, | |
5831 | struct bpf_insn_access_aux *info) | |
5832 | { | |
38207291 | 5833 | const struct btf_type *t = prog->aux->attach_func_proto; |
3aac1ead | 5834 | struct bpf_prog *tgt_prog = prog->aux->dst_prog; |
5b92a28a | 5835 | struct btf *btf = bpf_prog_get_target_btf(prog); |
38207291 | 5836 | const char *tname = prog->aux->attach_func_name; |
9e15db66 | 5837 | struct bpf_verifier_log *log = info->log; |
9e15db66 | 5838 | const struct btf_param *args; |
c6f1bfe8 | 5839 | const char *tag_value; |
9e15db66 | 5840 | u32 nr_args, arg; |
3c32cc1b | 5841 | int i, ret; |
9e15db66 | 5842 | |
9e15db66 | 5843 | if (off % 8) { |
38207291 | 5844 | bpf_log(log, "func '%s' offset %d is not multiple of 8\n", |
9e15db66 AS |
5845 | tname, off); |
5846 | return false; | |
5847 | } | |
720e6a43 | 5848 | arg = get_ctx_arg_idx(btf, t, off); |
9e15db66 | 5849 | args = (const struct btf_param *)(t + 1); |
523a4cf4 DB |
5850 | /* if (t == NULL) Fall back to default BPF prog with |
5851 | * MAX_BPF_FUNC_REG_ARGS u64 arguments. | |
5852 | */ | |
5853 | nr_args = t ? btf_type_vlen(t) : MAX_BPF_FUNC_REG_ARGS; | |
38207291 MKL |
5854 | if (prog->aux->attach_btf_trace) { |
5855 | /* skip first 'void *__data' argument in btf_trace_##name typedef */ | |
5856 | args++; | |
5857 | nr_args--; | |
5858 | } | |
fec56f58 | 5859 | |
f50b49a0 KS |
5860 | if (arg > nr_args) { |
5861 | bpf_log(log, "func '%s' doesn't have %d-th argument\n", | |
5862 | tname, arg + 1); | |
5863 | return false; | |
5864 | } | |
5865 | ||
6ba43b76 | 5866 | if (arg == nr_args) { |
f50b49a0 | 5867 | switch (prog->expected_attach_type) { |
69fd337a | 5868 | case BPF_LSM_CGROUP: |
f50b49a0 KS |
5869 | case BPF_LSM_MAC: |
5870 | case BPF_TRACE_FEXIT: | |
9e4e01df KS |
5871 | /* When LSM programs are attached to void LSM hooks |
5872 | * they use FEXIT trampolines and when attached to | |
5873 | * int LSM hooks, they use MODIFY_RETURN trampolines. | |
5874 | * | |
5875 | * While the LSM programs are BPF_MODIFY_RETURN-like | |
5876 | * the check: | |
5877 | * | |
5878 | * if (ret_type != 'int') | |
5879 | * return -EINVAL; | |
5880 | * | |
5881 | * is _not_ done here. This is still safe as LSM hooks | |
5882 | * have only void and int return types. | |
5883 | */ | |
6ba43b76 KS |
5884 | if (!t) |
5885 | return true; | |
5886 | t = btf_type_by_id(btf, t->type); | |
f50b49a0 KS |
5887 | break; |
5888 | case BPF_MODIFY_RETURN: | |
6ba43b76 KS |
5889 | /* For now the BPF_MODIFY_RETURN can only be attached to |
5890 | * functions that return an int. | |
5891 | */ | |
5892 | if (!t) | |
5893 | return false; | |
5894 | ||
5895 | t = btf_type_skip_modifiers(btf, t->type, NULL); | |
a9b59159 | 5896 | if (!btf_type_is_small_int(t)) { |
6ba43b76 KS |
5897 | bpf_log(log, |
5898 | "ret type %s not allowed for fmod_ret\n", | |
571f9738 | 5899 | btf_type_str(t)); |
6ba43b76 KS |
5900 | return false; |
5901 | } | |
f50b49a0 KS |
5902 | break; |
5903 | default: | |
5904 | bpf_log(log, "func '%s' doesn't have %d-th argument\n", | |
5905 | tname, arg + 1); | |
5906 | return false; | |
6ba43b76 | 5907 | } |
fec56f58 | 5908 | } else { |
5b92a28a | 5909 | if (!t) |
523a4cf4 | 5910 | /* Default prog with MAX_BPF_FUNC_REG_ARGS args */ |
5b92a28a AS |
5911 | return true; |
5912 | t = btf_type_by_id(btf, args[arg].type); | |
9e15db66 | 5913 | } |
f50b49a0 | 5914 | |
9e15db66 AS |
5915 | /* skip modifiers */ |
5916 | while (btf_type_is_modifier(t)) | |
5b92a28a | 5917 | t = btf_type_by_id(btf, t->type); |
720e6a43 | 5918 | if (btf_type_is_small_int(t) || btf_is_any_enum(t) || __btf_type_is_struct(t)) |
9e15db66 AS |
5919 | /* accessing a scalar */ |
5920 | return true; | |
5921 | if (!btf_type_is_ptr(t)) { | |
5922 | bpf_log(log, | |
38207291 | 5923 | "func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n", |
9e15db66 | 5924 | tname, arg, |
5b92a28a | 5925 | __btf_name_by_offset(btf, t->name_off), |
571f9738 | 5926 | btf_type_str(t)); |
9e15db66 AS |
5927 | return false; |
5928 | } | |
afbf21dc YS |
5929 | |
5930 | /* check for PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL */ | |
5931 | for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { | |
5932 | const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; | |
c25b2ae1 | 5933 | u32 type, flag; |
afbf21dc | 5934 | |
c25b2ae1 HL |
5935 | type = base_type(ctx_arg_info->reg_type); |
5936 | flag = type_flag(ctx_arg_info->reg_type); | |
20b2aff4 | 5937 | if (ctx_arg_info->offset == off && type == PTR_TO_BUF && |
c25b2ae1 | 5938 | (flag & PTR_MAYBE_NULL)) { |
afbf21dc YS |
5939 | info->reg_type = ctx_arg_info->reg_type; |
5940 | return true; | |
5941 | } | |
5942 | } | |
5943 | ||
9e15db66 AS |
5944 | if (t->type == 0) |
5945 | /* This is a pointer to void. | |
5946 | * It is the same as scalar from the verifier safety pov. | |
5947 | * No further pointer walking is allowed. | |
5948 | */ | |
5949 | return true; | |
5950 | ||
bb6728d7 | 5951 | if (is_int_ptr(btf, t)) |
84ad7a7a JO |
5952 | return true; |
5953 | ||
9e15db66 | 5954 | /* this is a pointer to another type */ |
3c32cc1b YS |
5955 | for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { |
5956 | const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; | |
5957 | ||
5958 | if (ctx_arg_info->offset == off) { | |
d3621642 YS |
5959 | if (!ctx_arg_info->btf_id) { |
5960 | bpf_log(log,"invalid btf_id for context argument offset %u\n", off); | |
5961 | return false; | |
5962 | } | |
5963 | ||
3c32cc1b | 5964 | info->reg_type = ctx_arg_info->reg_type; |
22dc4a0f | 5965 | info->btf = btf_vmlinux; |
951cf368 YS |
5966 | info->btf_id = ctx_arg_info->btf_id; |
5967 | return true; | |
3c32cc1b YS |
5968 | } |
5969 | } | |
9e15db66 | 5970 | |
951cf368 | 5971 | info->reg_type = PTR_TO_BTF_ID; |
3f00c523 DV |
5972 | if (prog_type_args_trusted(prog->type)) |
5973 | info->reg_type |= PTR_TRUSTED; | |
5974 | ||
5b92a28a | 5975 | if (tgt_prog) { |
43bc2874 THJ |
5976 | enum bpf_prog_type tgt_type; |
5977 | ||
5978 | if (tgt_prog->type == BPF_PROG_TYPE_EXT) | |
5979 | tgt_type = tgt_prog->aux->saved_dst_prog_type; | |
5980 | else | |
5981 | tgt_type = tgt_prog->type; | |
5982 | ||
5983 | ret = btf_translate_to_vmlinux(log, btf, t, tgt_type, arg); | |
5b92a28a | 5984 | if (ret > 0) { |
22dc4a0f | 5985 | info->btf = btf_vmlinux; |
5b92a28a AS |
5986 | info->btf_id = ret; |
5987 | return true; | |
5988 | } else { | |
5989 | return false; | |
5990 | } | |
5991 | } | |
275517ff | 5992 | |
22dc4a0f | 5993 | info->btf = btf; |
275517ff | 5994 | info->btf_id = t->type; |
5b92a28a | 5995 | t = btf_type_by_id(btf, t->type); |
c6f1bfe8 YS |
5996 | |
5997 | if (btf_type_is_type_tag(t)) { | |
5998 | tag_value = __btf_name_by_offset(btf, t->name_off); | |
5999 | if (strcmp(tag_value, "user") == 0) | |
6000 | info->reg_type |= MEM_USER; | |
5844101a HL |
6001 | if (strcmp(tag_value, "percpu") == 0) |
6002 | info->reg_type |= MEM_PERCPU; | |
c6f1bfe8 YS |
6003 | } |
6004 | ||
9e15db66 | 6005 | /* skip modifiers */ |
275517ff MKL |
6006 | while (btf_type_is_modifier(t)) { |
6007 | info->btf_id = t->type; | |
5b92a28a | 6008 | t = btf_type_by_id(btf, t->type); |
275517ff | 6009 | } |
9e15db66 AS |
6010 | if (!btf_type_is_struct(t)) { |
6011 | bpf_log(log, | |
38207291 | 6012 | "func '%s' arg%d type %s is not a struct\n", |
571f9738 | 6013 | tname, arg, btf_type_str(t)); |
9e15db66 AS |
6014 | return false; |
6015 | } | |
38207291 | 6016 | bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n", |
571f9738 | 6017 | tname, arg, info->btf_id, btf_type_str(t), |
5b92a28a | 6018 | __btf_name_by_offset(btf, t->name_off)); |
9e15db66 AS |
6019 | return true; |
6020 | } | |
6021 | ||
1c6d28a6 JO |
6022 | enum bpf_struct_walk_result { |
6023 | /* < 0 error */ | |
6024 | WALK_SCALAR = 0, | |
6025 | WALK_PTR, | |
6026 | WALK_STRUCT, | |
6027 | }; | |
6028 | ||
22dc4a0f | 6029 | static int btf_struct_walk(struct bpf_verifier_log *log, const struct btf *btf, |
1c6d28a6 | 6030 | const struct btf_type *t, int off, int size, |
c6f1bfe8 | 6031 | u32 *next_btf_id, enum bpf_type_flag *flag) |
9e15db66 | 6032 | { |
7e3617a7 MKL |
6033 | u32 i, moff, mtrue_end, msize = 0, total_nelems = 0; |
6034 | const struct btf_type *mtype, *elem_type = NULL; | |
9e15db66 | 6035 | const struct btf_member *member; |
c6f1bfe8 | 6036 | const char *tname, *mname, *tag_value; |
1c6d28a6 | 6037 | u32 vlen, elem_id, mid; |
9e15db66 AS |
6038 | |
6039 | again: | |
22dc4a0f | 6040 | tname = __btf_name_by_offset(btf, t->name_off); |
9e15db66 | 6041 | if (!btf_type_is_struct(t)) { |
275517ff | 6042 | bpf_log(log, "Type '%s' is not a struct\n", tname); |
9e15db66 AS |
6043 | return -EINVAL; |
6044 | } | |
6045 | ||
9c5f8a10 | 6046 | vlen = btf_type_vlen(t); |
976aba00 | 6047 | if (off + size > t->size) { |
9c5f8a10 YS |
6048 | /* If the last element is a variable size array, we may |
6049 | * need to relax the rule. | |
6050 | */ | |
6051 | struct btf_array *array_elem; | |
6052 | ||
6053 | if (vlen == 0) | |
6054 | goto error; | |
6055 | ||
6056 | member = btf_type_member(t) + vlen - 1; | |
22dc4a0f | 6057 | mtype = btf_type_skip_modifiers(btf, member->type, |
9c5f8a10 YS |
6058 | NULL); |
6059 | if (!btf_type_is_array(mtype)) | |
6060 | goto error; | |
6061 | ||
6062 | array_elem = (struct btf_array *)(mtype + 1); | |
6063 | if (array_elem->nelems != 0) | |
6064 | goto error; | |
6065 | ||
8293eb99 | 6066 | moff = __btf_member_bit_offset(t, member) / 8; |
9c5f8a10 YS |
6067 | if (off < moff) |
6068 | goto error; | |
6069 | ||
6070 | /* Only allow structure for now, can be relaxed for | |
6071 | * other types later. | |
6072 | */ | |
22dc4a0f | 6073 | t = btf_type_skip_modifiers(btf, array_elem->type, |
dafe58fc JO |
6074 | NULL); |
6075 | if (!btf_type_is_struct(t)) | |
9c5f8a10 YS |
6076 | goto error; |
6077 | ||
dafe58fc JO |
6078 | off = (off - moff) % t->size; |
6079 | goto again; | |
9c5f8a10 YS |
6080 | |
6081 | error: | |
976aba00 MKL |
6082 | bpf_log(log, "access beyond struct %s at off %u size %u\n", |
6083 | tname, off, size); | |
6084 | return -EACCES; | |
6085 | } | |
9e15db66 | 6086 | |
976aba00 | 6087 | for_each_member(i, t, member) { |
7e3617a7 | 6088 | /* offset of the field in bytes */ |
8293eb99 | 6089 | moff = __btf_member_bit_offset(t, member) / 8; |
7e3617a7 | 6090 | if (off + size <= moff) |
9e15db66 AS |
6091 | /* won't find anything, field is already too far */ |
6092 | break; | |
976aba00 | 6093 | |
8293eb99 AS |
6094 | if (__btf_member_bitfield_size(t, member)) { |
6095 | u32 end_bit = __btf_member_bit_offset(t, member) + | |
6096 | __btf_member_bitfield_size(t, member); | |
976aba00 MKL |
6097 | |
6098 | /* off <= moff instead of off == moff because clang | |
6099 | * does not generate a BTF member for anonymous | |
6100 | * bitfield like the ":16" here: | |
6101 | * struct { | |
6102 | * int :16; | |
6103 | * int x:8; | |
6104 | * }; | |
6105 | */ | |
6106 | if (off <= moff && | |
6107 | BITS_ROUNDUP_BYTES(end_bit) <= off + size) | |
1c6d28a6 | 6108 | return WALK_SCALAR; |
976aba00 MKL |
6109 | |
6110 | /* off may be accessing a following member | |
6111 | * | |
6112 | * or | |
6113 | * | |
6114 | * Doing partial access at either end of this | |
6115 | * bitfield. Continue on this case also to | |
6116 | * treat it as not accessing this bitfield | |
6117 | * and eventually error out as field not | |
6118 | * found to keep it simple. | |
6119 | * It could be relaxed if there was a legit | |
6120 | * partial access case later. | |
6121 | */ | |
6122 | continue; | |
6123 | } | |
6124 | ||
7e3617a7 MKL |
6125 | /* In case of "off" is pointing to holes of a struct */ |
6126 | if (off < moff) | |
976aba00 | 6127 | break; |
9e15db66 AS |
6128 | |
6129 | /* type of the field */ | |
1c6d28a6 | 6130 | mid = member->type; |
22dc4a0f AN |
6131 | mtype = btf_type_by_id(btf, member->type); |
6132 | mname = __btf_name_by_offset(btf, member->name_off); | |
9e15db66 | 6133 | |
22dc4a0f | 6134 | mtype = __btf_resolve_size(btf, mtype, &msize, |
1c6d28a6 JO |
6135 | &elem_type, &elem_id, &total_nelems, |
6136 | &mid); | |
7e3617a7 | 6137 | if (IS_ERR(mtype)) { |
9e15db66 AS |
6138 | bpf_log(log, "field %s doesn't have size\n", mname); |
6139 | return -EFAULT; | |
6140 | } | |
7e3617a7 MKL |
6141 | |
6142 | mtrue_end = moff + msize; | |
6143 | if (off >= mtrue_end) | |
9e15db66 AS |
6144 | /* no overlap with member, keep iterating */ |
6145 | continue; | |
7e3617a7 MKL |
6146 | |
6147 | if (btf_type_is_array(mtype)) { | |
6148 | u32 elem_idx; | |
6149 | ||
6298399b | 6150 | /* __btf_resolve_size() above helps to |
7e3617a7 MKL |
6151 | * linearize a multi-dimensional array. |
6152 | * | |
6153 | * The logic here is treating an array | |
6154 | * in a struct as the following way: | |
6155 | * | |
6156 | * struct outer { | |
6157 | * struct inner array[2][2]; | |
6158 | * }; | |
6159 | * | |
6160 | * looks like: | |
6161 | * | |
6162 | * struct outer { | |
6163 | * struct inner array_elem0; | |
6164 | * struct inner array_elem1; | |
6165 | * struct inner array_elem2; | |
6166 | * struct inner array_elem3; | |
6167 | * }; | |
6168 | * | |
6169 | * When accessing outer->array[1][0], it moves | |
6170 | * moff to "array_elem2", set mtype to | |
6171 | * "struct inner", and msize also becomes | |
6172 | * sizeof(struct inner). Then most of the | |
6173 | * remaining logic will fall through without | |
6174 | * caring the current member is an array or | |
6175 | * not. | |
6176 | * | |
6177 | * Unlike mtype/msize/moff, mtrue_end does not | |
6178 | * change. The naming difference ("_true") tells | |
6179 | * that it is not always corresponding to | |
6180 | * the current mtype/msize/moff. | |
6181 | * It is the true end of the current | |
6182 | * member (i.e. array in this case). That | |
6183 | * will allow an int array to be accessed like | |
6184 | * a scratch space, | |
6185 | * i.e. allow access beyond the size of | |
6186 | * the array's element as long as it is | |
6187 | * within the mtrue_end boundary. | |
6188 | */ | |
6189 | ||
6190 | /* skip empty array */ | |
6191 | if (moff == mtrue_end) | |
6192 | continue; | |
6193 | ||
6194 | msize /= total_nelems; | |
6195 | elem_idx = (off - moff) / msize; | |
6196 | moff += elem_idx * msize; | |
6197 | mtype = elem_type; | |
1c6d28a6 | 6198 | mid = elem_id; |
7e3617a7 MKL |
6199 | } |
6200 | ||
9e15db66 AS |
6201 | /* the 'off' we're looking for is either equal to start |
6202 | * of this field or inside of this struct | |
6203 | */ | |
6204 | if (btf_type_is_struct(mtype)) { | |
6205 | /* our field must be inside that union or struct */ | |
6206 | t = mtype; | |
6207 | ||
1c6d28a6 JO |
6208 | /* return if the offset matches the member offset */ |
6209 | if (off == moff) { | |
6210 | *next_btf_id = mid; | |
6211 | return WALK_STRUCT; | |
6212 | } | |
6213 | ||
9e15db66 | 6214 | /* adjust offset we're looking for */ |
7e3617a7 | 6215 | off -= moff; |
9e15db66 AS |
6216 | goto again; |
6217 | } | |
9e15db66 AS |
6218 | |
6219 | if (btf_type_is_ptr(mtype)) { | |
c6f1bfe8 YS |
6220 | const struct btf_type *stype, *t; |
6221 | enum bpf_type_flag tmp_flag = 0; | |
257af63d | 6222 | u32 id; |
9e15db66 | 6223 | |
7e3617a7 MKL |
6224 | if (msize != size || off != moff) { |
6225 | bpf_log(log, | |
6226 | "cannot access ptr member %s with moff %u in struct %s with off %u size %u\n", | |
6227 | mname, moff, tname, off, size); | |
6228 | return -EACCES; | |
6229 | } | |
c6f1bfe8 | 6230 | |
5844101a | 6231 | /* check type tag */ |
c6f1bfe8 YS |
6232 | t = btf_type_by_id(btf, mtype->type); |
6233 | if (btf_type_is_type_tag(t)) { | |
6234 | tag_value = __btf_name_by_offset(btf, t->name_off); | |
5844101a | 6235 | /* check __user tag */ |
c6f1bfe8 YS |
6236 | if (strcmp(tag_value, "user") == 0) |
6237 | tmp_flag = MEM_USER; | |
5844101a HL |
6238 | /* check __percpu tag */ |
6239 | if (strcmp(tag_value, "percpu") == 0) | |
6240 | tmp_flag = MEM_PERCPU; | |
9bb00b28 YS |
6241 | /* check __rcu tag */ |
6242 | if (strcmp(tag_value, "rcu") == 0) | |
6243 | tmp_flag = MEM_RCU; | |
c6f1bfe8 YS |
6244 | } |
6245 | ||
22dc4a0f | 6246 | stype = btf_type_skip_modifiers(btf, mtype->type, &id); |
9e15db66 | 6247 | if (btf_type_is_struct(stype)) { |
257af63d | 6248 | *next_btf_id = id; |
c6f1bfe8 | 6249 | *flag = tmp_flag; |
1c6d28a6 | 6250 | return WALK_PTR; |
9e15db66 AS |
6251 | } |
6252 | } | |
7e3617a7 MKL |
6253 | |
6254 | /* Allow more flexible access within an int as long as | |
6255 | * it is within mtrue_end. | |
6256 | * Since mtrue_end could be the end of an array, | |
6257 | * that also allows using an array of int as a scratch | |
6258 | * space. e.g. skb->cb[]. | |
6259 | */ | |
6260 | if (off + size > mtrue_end) { | |
6261 | bpf_log(log, | |
6262 | "access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n", | |
6263 | mname, mtrue_end, tname, off, size); | |
6264 | return -EACCES; | |
6265 | } | |
6266 | ||
1c6d28a6 | 6267 | return WALK_SCALAR; |
9e15db66 AS |
6268 | } |
6269 | bpf_log(log, "struct %s doesn't have field at offset %d\n", tname, off); | |
6270 | return -EINVAL; | |
6271 | } | |
6272 | ||
6728aea7 KKD |
6273 | int btf_struct_access(struct bpf_verifier_log *log, |
6274 | const struct bpf_reg_state *reg, | |
6275 | int off, int size, enum bpf_access_type atype __maybe_unused, | |
c6f1bfe8 | 6276 | u32 *next_btf_id, enum bpf_type_flag *flag) |
1c6d28a6 | 6277 | { |
6728aea7 | 6278 | const struct btf *btf = reg->btf; |
c6f1bfe8 | 6279 | enum bpf_type_flag tmp_flag = 0; |
6728aea7 KKD |
6280 | const struct btf_type *t; |
6281 | u32 id = reg->btf_id; | |
1c6d28a6 | 6282 | int err; |
1c6d28a6 | 6283 | |
8ffa5cc1 KKD |
6284 | while (type_is_alloc(reg->type)) { |
6285 | struct btf_struct_meta *meta; | |
6286 | struct btf_record *rec; | |
6287 | int i; | |
6288 | ||
6289 | meta = btf_find_struct_meta(btf, id); | |
6290 | if (!meta) | |
6291 | break; | |
6292 | rec = meta->record; | |
6293 | for (i = 0; i < rec->cnt; i++) { | |
6294 | struct btf_field *field = &rec->fields[i]; | |
6295 | u32 offset = field->offset; | |
6296 | if (off < offset + btf_field_type_size(field->type) && offset < off + size) { | |
6297 | bpf_log(log, | |
6298 | "direct access to %s is disallowed\n", | |
6299 | btf_field_type_name(field->type)); | |
6300 | return -EACCES; | |
6301 | } | |
6302 | } | |
6303 | break; | |
6304 | } | |
6305 | ||
6728aea7 | 6306 | t = btf_type_by_id(btf, id); |
1c6d28a6 | 6307 | do { |
c6f1bfe8 | 6308 | err = btf_struct_walk(log, btf, t, off, size, &id, &tmp_flag); |
1c6d28a6 JO |
6309 | |
6310 | switch (err) { | |
6311 | case WALK_PTR: | |
282de143 KKD |
6312 | /* For local types, the destination register cannot |
6313 | * become a pointer again. | |
6314 | */ | |
6315 | if (type_is_alloc(reg->type)) | |
6316 | return SCALAR_VALUE; | |
1c6d28a6 JO |
6317 | /* If we found the pointer or scalar on t+off, |
6318 | * we're done. | |
6319 | */ | |
6320 | *next_btf_id = id; | |
c6f1bfe8 | 6321 | *flag = tmp_flag; |
1c6d28a6 JO |
6322 | return PTR_TO_BTF_ID; |
6323 | case WALK_SCALAR: | |
6324 | return SCALAR_VALUE; | |
6325 | case WALK_STRUCT: | |
6326 | /* We found nested struct, so continue the search | |
6327 | * by diving in it. At this point the offset is | |
6328 | * aligned with the new type, so set it to 0. | |
6329 | */ | |
22dc4a0f | 6330 | t = btf_type_by_id(btf, id); |
1c6d28a6 JO |
6331 | off = 0; |
6332 | break; | |
6333 | default: | |
6334 | /* It's either error or unknown return value.. | |
6335 | * scream and leave. | |
6336 | */ | |
6337 | if (WARN_ONCE(err > 0, "unknown btf_struct_walk return value")) | |
6338 | return -EINVAL; | |
6339 | return err; | |
6340 | } | |
6341 | } while (t); | |
6342 | ||
6343 | return -EINVAL; | |
6344 | } | |
6345 | ||
22dc4a0f AN |
6346 | /* Check that two BTF types, each specified as an BTF object + id, are exactly |
6347 | * the same. Trivial ID check is not enough due to module BTFs, because we can | |
6348 | * end up with two different module BTFs, but IDs point to the common type in | |
6349 | * vmlinux BTF. | |
6350 | */ | |
00b85860 KKD |
6351 | bool btf_types_are_same(const struct btf *btf1, u32 id1, |
6352 | const struct btf *btf2, u32 id2) | |
22dc4a0f AN |
6353 | { |
6354 | if (id1 != id2) | |
6355 | return false; | |
6356 | if (btf1 == btf2) | |
6357 | return true; | |
6358 | return btf_type_by_id(btf1, id1) == btf_type_by_id(btf2, id2); | |
6359 | } | |
6360 | ||
faaf4a79 | 6361 | bool btf_struct_ids_match(struct bpf_verifier_log *log, |
22dc4a0f | 6362 | const struct btf *btf, u32 id, int off, |
2ab3b380 KKD |
6363 | const struct btf *need_btf, u32 need_type_id, |
6364 | bool strict) | |
faaf4a79 JO |
6365 | { |
6366 | const struct btf_type *type; | |
c6f1bfe8 | 6367 | enum bpf_type_flag flag; |
faaf4a79 JO |
6368 | int err; |
6369 | ||
6370 | /* Are we already done? */ | |
22dc4a0f | 6371 | if (off == 0 && btf_types_are_same(btf, id, need_btf, need_type_id)) |
faaf4a79 | 6372 | return true; |
2ab3b380 KKD |
6373 | /* In case of strict type match, we do not walk struct, the top level |
6374 | * type match must succeed. When strict is true, off should have already | |
6375 | * been 0. | |
6376 | */ | |
6377 | if (strict) | |
6378 | return false; | |
faaf4a79 | 6379 | again: |
22dc4a0f | 6380 | type = btf_type_by_id(btf, id); |
faaf4a79 JO |
6381 | if (!type) |
6382 | return false; | |
c6f1bfe8 | 6383 | err = btf_struct_walk(log, btf, type, off, 1, &id, &flag); |
faaf4a79 JO |
6384 | if (err != WALK_STRUCT) |
6385 | return false; | |
6386 | ||
6387 | /* We found nested struct object. If it matches | |
6388 | * the requested ID, we're done. Otherwise let's | |
6389 | * continue the search with offset 0 in the new | |
6390 | * type. | |
6391 | */ | |
22dc4a0f | 6392 | if (!btf_types_are_same(btf, id, need_btf, need_type_id)) { |
faaf4a79 JO |
6393 | off = 0; |
6394 | goto again; | |
6395 | } | |
6396 | ||
6397 | return true; | |
6398 | } | |
6399 | ||
fec56f58 | 6400 | static int __get_type_size(struct btf *btf, u32 btf_id, |
a00ed843 | 6401 | const struct btf_type **ret_type) |
fec56f58 AS |
6402 | { |
6403 | const struct btf_type *t; | |
6404 | ||
a00ed843 | 6405 | *ret_type = btf_type_by_id(btf, 0); |
fec56f58 AS |
6406 | if (!btf_id) |
6407 | /* void */ | |
6408 | return 0; | |
6409 | t = btf_type_by_id(btf, btf_id); | |
6410 | while (t && btf_type_is_modifier(t)) | |
6411 | t = btf_type_by_id(btf, t->type); | |
a00ed843 | 6412 | if (!t) |
fec56f58 | 6413 | return -EINVAL; |
a00ed843 | 6414 | *ret_type = t; |
fec56f58 AS |
6415 | if (btf_type_is_ptr(t)) |
6416 | /* kernel size of pointer. Not BPF's size of pointer*/ | |
6417 | return sizeof(void *); | |
720e6a43 | 6418 | if (btf_type_is_int(t) || btf_is_any_enum(t) || __btf_type_is_struct(t)) |
fec56f58 | 6419 | return t->size; |
fec56f58 AS |
6420 | return -EINVAL; |
6421 | } | |
6422 | ||
6423 | int btf_distill_func_proto(struct bpf_verifier_log *log, | |
6424 | struct btf *btf, | |
6425 | const struct btf_type *func, | |
6426 | const char *tname, | |
6427 | struct btf_func_model *m) | |
6428 | { | |
6429 | const struct btf_param *args; | |
6430 | const struct btf_type *t; | |
6431 | u32 i, nargs; | |
6432 | int ret; | |
6433 | ||
5b92a28a AS |
6434 | if (!func) { |
6435 | /* BTF function prototype doesn't match the verifier types. | |
523a4cf4 | 6436 | * Fall back to MAX_BPF_FUNC_REG_ARGS u64 args. |
5b92a28a | 6437 | */ |
720e6a43 | 6438 | for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++) { |
5b92a28a | 6439 | m->arg_size[i] = 8; |
720e6a43 YS |
6440 | m->arg_flags[i] = 0; |
6441 | } | |
5b92a28a | 6442 | m->ret_size = 8; |
523a4cf4 | 6443 | m->nr_args = MAX_BPF_FUNC_REG_ARGS; |
5b92a28a AS |
6444 | return 0; |
6445 | } | |
fec56f58 AS |
6446 | args = (const struct btf_param *)(func + 1); |
6447 | nargs = btf_type_vlen(func); | |
c29a4920 | 6448 | if (nargs > MAX_BPF_FUNC_ARGS) { |
fec56f58 AS |
6449 | bpf_log(log, |
6450 | "The function %s has %d arguments. Too many.\n", | |
6451 | tname, nargs); | |
6452 | return -EINVAL; | |
6453 | } | |
6454 | ret = __get_type_size(btf, func->type, &t); | |
720e6a43 | 6455 | if (ret < 0 || __btf_type_is_struct(t)) { |
fec56f58 AS |
6456 | bpf_log(log, |
6457 | "The function %s return type %s is unsupported.\n", | |
571f9738 | 6458 | tname, btf_type_str(t)); |
fec56f58 AS |
6459 | return -EINVAL; |
6460 | } | |
6461 | m->ret_size = ret; | |
6462 | ||
6463 | for (i = 0; i < nargs; i++) { | |
31379397 JO |
6464 | if (i == nargs - 1 && args[i].type == 0) { |
6465 | bpf_log(log, | |
6466 | "The function %s with variable args is unsupported.\n", | |
6467 | tname); | |
6468 | return -EINVAL; | |
6469 | } | |
fec56f58 | 6470 | ret = __get_type_size(btf, args[i].type, &t); |
720e6a43 YS |
6471 | |
6472 | /* No support of struct argument size greater than 16 bytes */ | |
6473 | if (ret < 0 || ret > 16) { | |
fec56f58 AS |
6474 | bpf_log(log, |
6475 | "The function %s arg%d type %s is unsupported.\n", | |
571f9738 | 6476 | tname, i, btf_type_str(t)); |
fec56f58 AS |
6477 | return -EINVAL; |
6478 | } | |
31379397 JO |
6479 | if (ret == 0) { |
6480 | bpf_log(log, | |
6481 | "The function %s has malformed void argument.\n", | |
6482 | tname); | |
6483 | return -EINVAL; | |
6484 | } | |
fec56f58 | 6485 | m->arg_size[i] = ret; |
720e6a43 | 6486 | m->arg_flags[i] = __btf_type_is_struct(t) ? BTF_FMODEL_STRUCT_ARG : 0; |
fec56f58 AS |
6487 | } |
6488 | m->nr_args = nargs; | |
6489 | return 0; | |
6490 | } | |
6491 | ||
be8704ff AS |
6492 | /* Compare BTFs of two functions assuming only scalars and pointers to context. |
6493 | * t1 points to BTF_KIND_FUNC in btf1 | |
6494 | * t2 points to BTF_KIND_FUNC in btf2 | |
6495 | * Returns: | |
6496 | * EINVAL - function prototype mismatch | |
6497 | * EFAULT - verifier bug | |
6498 | * 0 - 99% match. The last 1% is validated by the verifier. | |
6499 | */ | |
2bf0eb9b HY |
6500 | static int btf_check_func_type_match(struct bpf_verifier_log *log, |
6501 | struct btf *btf1, const struct btf_type *t1, | |
6502 | struct btf *btf2, const struct btf_type *t2) | |
be8704ff AS |
6503 | { |
6504 | const struct btf_param *args1, *args2; | |
6505 | const char *fn1, *fn2, *s1, *s2; | |
6506 | u32 nargs1, nargs2, i; | |
6507 | ||
6508 | fn1 = btf_name_by_offset(btf1, t1->name_off); | |
6509 | fn2 = btf_name_by_offset(btf2, t2->name_off); | |
6510 | ||
6511 | if (btf_func_linkage(t1) != BTF_FUNC_GLOBAL) { | |
6512 | bpf_log(log, "%s() is not a global function\n", fn1); | |
6513 | return -EINVAL; | |
6514 | } | |
6515 | if (btf_func_linkage(t2) != BTF_FUNC_GLOBAL) { | |
6516 | bpf_log(log, "%s() is not a global function\n", fn2); | |
6517 | return -EINVAL; | |
6518 | } | |
6519 | ||
6520 | t1 = btf_type_by_id(btf1, t1->type); | |
6521 | if (!t1 || !btf_type_is_func_proto(t1)) | |
6522 | return -EFAULT; | |
6523 | t2 = btf_type_by_id(btf2, t2->type); | |
6524 | if (!t2 || !btf_type_is_func_proto(t2)) | |
6525 | return -EFAULT; | |
6526 | ||
6527 | args1 = (const struct btf_param *)(t1 + 1); | |
6528 | nargs1 = btf_type_vlen(t1); | |
6529 | args2 = (const struct btf_param *)(t2 + 1); | |
6530 | nargs2 = btf_type_vlen(t2); | |
6531 | ||
6532 | if (nargs1 != nargs2) { | |
6533 | bpf_log(log, "%s() has %d args while %s() has %d args\n", | |
6534 | fn1, nargs1, fn2, nargs2); | |
6535 | return -EINVAL; | |
6536 | } | |
6537 | ||
6538 | t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); | |
6539 | t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); | |
6540 | if (t1->info != t2->info) { | |
6541 | bpf_log(log, | |
6542 | "Return type %s of %s() doesn't match type %s of %s()\n", | |
6543 | btf_type_str(t1), fn1, | |
6544 | btf_type_str(t2), fn2); | |
6545 | return -EINVAL; | |
6546 | } | |
6547 | ||
6548 | for (i = 0; i < nargs1; i++) { | |
6549 | t1 = btf_type_skip_modifiers(btf1, args1[i].type, NULL); | |
6550 | t2 = btf_type_skip_modifiers(btf2, args2[i].type, NULL); | |
6551 | ||
6552 | if (t1->info != t2->info) { | |
6553 | bpf_log(log, "arg%d in %s() is %s while %s() has %s\n", | |
6554 | i, fn1, btf_type_str(t1), | |
6555 | fn2, btf_type_str(t2)); | |
6556 | return -EINVAL; | |
6557 | } | |
6558 | if (btf_type_has_size(t1) && t1->size != t2->size) { | |
6559 | bpf_log(log, | |
6560 | "arg%d in %s() has size %d while %s() has %d\n", | |
6561 | i, fn1, t1->size, | |
6562 | fn2, t2->size); | |
6563 | return -EINVAL; | |
6564 | } | |
6565 | ||
6566 | /* global functions are validated with scalars and pointers | |
6567 | * to context only. And only global functions can be replaced. | |
6568 | * Hence type check only those types. | |
6569 | */ | |
6089fb32 | 6570 | if (btf_type_is_int(t1) || btf_is_any_enum(t1)) |
be8704ff AS |
6571 | continue; |
6572 | if (!btf_type_is_ptr(t1)) { | |
6573 | bpf_log(log, | |
6574 | "arg%d in %s() has unrecognized type\n", | |
6575 | i, fn1); | |
6576 | return -EINVAL; | |
6577 | } | |
6578 | t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); | |
6579 | t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); | |
6580 | if (!btf_type_is_struct(t1)) { | |
6581 | bpf_log(log, | |
6582 | "arg%d in %s() is not a pointer to context\n", | |
6583 | i, fn1); | |
6584 | return -EINVAL; | |
6585 | } | |
6586 | if (!btf_type_is_struct(t2)) { | |
6587 | bpf_log(log, | |
6588 | "arg%d in %s() is not a pointer to context\n", | |
6589 | i, fn2); | |
6590 | return -EINVAL; | |
6591 | } | |
6592 | /* This is an optional check to make program writing easier. | |
6593 | * Compare names of structs and report an error to the user. | |
6594 | * btf_prepare_func_args() already checked that t2 struct | |
6595 | * is a context type. btf_prepare_func_args() will check | |
6596 | * later that t1 struct is a context type as well. | |
6597 | */ | |
6598 | s1 = btf_name_by_offset(btf1, t1->name_off); | |
6599 | s2 = btf_name_by_offset(btf2, t2->name_off); | |
6600 | if (strcmp(s1, s2)) { | |
6601 | bpf_log(log, | |
6602 | "arg%d %s(struct %s *) doesn't match %s(struct %s *)\n", | |
6603 | i, fn1, s1, fn2, s2); | |
6604 | return -EINVAL; | |
6605 | } | |
6606 | } | |
6607 | return 0; | |
6608 | } | |
6609 | ||
6610 | /* Compare BTFs of given program with BTF of target program */ | |
efc68158 | 6611 | int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog, |
be8704ff AS |
6612 | struct btf *btf2, const struct btf_type *t2) |
6613 | { | |
6614 | struct btf *btf1 = prog->aux->btf; | |
6615 | const struct btf_type *t1; | |
6616 | u32 btf_id = 0; | |
6617 | ||
6618 | if (!prog->aux->func_info) { | |
efc68158 | 6619 | bpf_log(log, "Program extension requires BTF\n"); |
be8704ff AS |
6620 | return -EINVAL; |
6621 | } | |
6622 | ||
6623 | btf_id = prog->aux->func_info[0].type_id; | |
6624 | if (!btf_id) | |
6625 | return -EFAULT; | |
6626 | ||
6627 | t1 = btf_type_by_id(btf1, btf_id); | |
6628 | if (!t1 || !btf_type_is_func(t1)) | |
6629 | return -EFAULT; | |
6630 | ||
efc68158 | 6631 | return btf_check_func_type_match(log, btf1, t1, btf2, t2); |
be8704ff AS |
6632 | } |
6633 | ||
34747c41 MKL |
6634 | static int btf_check_func_arg_match(struct bpf_verifier_env *env, |
6635 | const struct btf *btf, u32 func_id, | |
6636 | struct bpf_reg_state *regs, | |
a4703e31 | 6637 | bool ptr_to_mem_ok, |
95f2f26f | 6638 | bool processing_call) |
8c1b6e69 | 6639 | { |
f858c2b2 | 6640 | enum bpf_prog_type prog_type = resolve_prog_type(env->prog); |
8c1b6e69 | 6641 | struct bpf_verifier_log *log = &env->log; |
34747c41 | 6642 | const char *func_name, *ref_tname; |
e5069b9c | 6643 | const struct btf_type *t, *ref_t; |
34747c41 | 6644 | const struct btf_param *args; |
00b85860 KKD |
6645 | u32 i, nargs, ref_id; |
6646 | int ret; | |
8c1b6e69 | 6647 | |
34747c41 | 6648 | t = btf_type_by_id(btf, func_id); |
8c1b6e69 | 6649 | if (!t || !btf_type_is_func(t)) { |
51c39bb1 | 6650 | /* These checks were already done by the verifier while loading |
e6ac2450 | 6651 | * struct bpf_func_info or in add_kfunc_call(). |
51c39bb1 | 6652 | */ |
34747c41 MKL |
6653 | bpf_log(log, "BTF of func_id %u doesn't point to KIND_FUNC\n", |
6654 | func_id); | |
51c39bb1 | 6655 | return -EFAULT; |
8c1b6e69 | 6656 | } |
34747c41 | 6657 | func_name = btf_name_by_offset(btf, t->name_off); |
8c1b6e69 AS |
6658 | |
6659 | t = btf_type_by_id(btf, t->type); | |
6660 | if (!t || !btf_type_is_func_proto(t)) { | |
34747c41 | 6661 | bpf_log(log, "Invalid BTF of func %s\n", func_name); |
51c39bb1 | 6662 | return -EFAULT; |
8c1b6e69 AS |
6663 | } |
6664 | args = (const struct btf_param *)(t + 1); | |
6665 | nargs = btf_type_vlen(t); | |
523a4cf4 | 6666 | if (nargs > MAX_BPF_FUNC_REG_ARGS) { |
34747c41 | 6667 | bpf_log(log, "Function %s has %d > %d args\n", func_name, nargs, |
523a4cf4 | 6668 | MAX_BPF_FUNC_REG_ARGS); |
34747c41 | 6669 | return -EINVAL; |
8c1b6e69 | 6670 | } |
e5069b9c | 6671 | |
8c1b6e69 AS |
6672 | /* check that BTF function arguments match actual types that the |
6673 | * verifier sees. | |
6674 | */ | |
6675 | for (i = 0; i < nargs; i++) { | |
8f14852e | 6676 | enum bpf_arg_type arg_type = ARG_DONTCARE; |
34747c41 MKL |
6677 | u32 regno = i + 1; |
6678 | struct bpf_reg_state *reg = ®s[regno]; | |
feb4adfa | 6679 | |
34747c41 MKL |
6680 | t = btf_type_skip_modifiers(btf, args[i].type, NULL); |
6681 | if (btf_type_is_scalar(t)) { | |
feb4adfa | 6682 | if (reg->type == SCALAR_VALUE) |
8c1b6e69 | 6683 | continue; |
34747c41 MKL |
6684 | bpf_log(log, "R%d is not a scalar\n", regno); |
6685 | return -EINVAL; | |
8c1b6e69 | 6686 | } |
34747c41 MKL |
6687 | |
6688 | if (!btf_type_is_ptr(t)) { | |
6689 | bpf_log(log, "Unrecognized arg#%d type %s\n", | |
6690 | i, btf_type_str(t)); | |
6691 | return -EINVAL; | |
6692 | } | |
6693 | ||
e6ac2450 | 6694 | ref_t = btf_type_skip_modifiers(btf, t->type, &ref_id); |
34747c41 | 6695 | ref_tname = btf_name_by_offset(btf, ref_t->name_off); |
655efe50 | 6696 | |
8f14852e | 6697 | ret = check_func_arg_reg_off(env, reg, regno, arg_type); |
655efe50 KKD |
6698 | if (ret < 0) |
6699 | return ret; | |
6700 | ||
00b85860 | 6701 | if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) { |
3363bd0c KKD |
6702 | /* If function expects ctx type in BTF check that caller |
6703 | * is passing PTR_TO_CTX. | |
6704 | */ | |
6705 | if (reg->type != PTR_TO_CTX) { | |
6706 | bpf_log(log, | |
6707 | "arg#%d expected pointer to ctx, but got %s\n", | |
6708 | i, btf_type_str(t)); | |
6709 | return -EINVAL; | |
6710 | } | |
95f2f26f | 6711 | } else if (ptr_to_mem_ok && processing_call) { |
34747c41 MKL |
6712 | const struct btf_type *resolve_ret; |
6713 | u32 type_size; | |
e5069b9c | 6714 | |
34747c41 MKL |
6715 | resolve_ret = btf_resolve_size(btf, ref_t, &type_size); |
6716 | if (IS_ERR(resolve_ret)) { | |
e5069b9c | 6717 | bpf_log(log, |
34747c41 MKL |
6718 | "arg#%d reference type('%s %s') size cannot be determined: %ld\n", |
6719 | i, btf_type_str(ref_t), ref_tname, | |
6720 | PTR_ERR(resolve_ret)); | |
6721 | return -EINVAL; | |
e5069b9c DB |
6722 | } |
6723 | ||
34747c41 MKL |
6724 | if (check_mem_reg(env, reg, regno, type_size)) |
6725 | return -EINVAL; | |
6726 | } else { | |
00b85860 KKD |
6727 | bpf_log(log, "reg type unsupported for arg#%d function %s#%d\n", i, |
6728 | func_name, func_id); | |
34747c41 | 6729 | return -EINVAL; |
8c1b6e69 | 6730 | } |
8c1b6e69 | 6731 | } |
34747c41 | 6732 | |
00b85860 | 6733 | return 0; |
34747c41 MKL |
6734 | } |
6735 | ||
95f2f26f | 6736 | /* Compare BTF of a function declaration with given bpf_reg_state. |
34747c41 MKL |
6737 | * Returns: |
6738 | * EFAULT - there is a verifier bug. Abort verification. | |
6739 | * EINVAL - there is a type mismatch or BTF is not available. | |
6740 | * 0 - BTF matches with what bpf_reg_state expects. | |
6741 | * Only PTR_TO_CTX and SCALAR_VALUE states are recognized. | |
6742 | */ | |
6743 | int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog, | |
6744 | struct bpf_reg_state *regs) | |
6745 | { | |
6746 | struct bpf_prog *prog = env->prog; | |
6747 | struct btf *btf = prog->aux->btf; | |
6748 | bool is_global; | |
6749 | u32 btf_id; | |
6750 | int err; | |
6751 | ||
6752 | if (!prog->aux->func_info) | |
6753 | return -EINVAL; | |
6754 | ||
6755 | btf_id = prog->aux->func_info[subprog].type_id; | |
6756 | if (!btf_id) | |
6757 | return -EFAULT; | |
6758 | ||
6759 | if (prog->aux->func_info_aux[subprog].unreliable) | |
6760 | return -EINVAL; | |
6761 | ||
6762 | is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL; | |
00b85860 | 6763 | err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, false); |
95f2f26f BT |
6764 | |
6765 | /* Compiler optimizations can remove arguments from static functions | |
6766 | * or mismatched type can be passed into a global function. | |
6767 | * In such cases mark the function as unreliable from BTF point of view. | |
6768 | */ | |
6769 | if (err) | |
6770 | prog->aux->func_info_aux[subprog].unreliable = true; | |
6771 | return err; | |
6772 | } | |
6773 | ||
6774 | /* Compare BTF of a function call with given bpf_reg_state. | |
6775 | * Returns: | |
6776 | * EFAULT - there is a verifier bug. Abort verification. | |
6777 | * EINVAL - there is a type mismatch or BTF is not available. | |
6778 | * 0 - BTF matches with what bpf_reg_state expects. | |
6779 | * Only PTR_TO_CTX and SCALAR_VALUE states are recognized. | |
6780 | * | |
6781 | * NOTE: the code is duplicated from btf_check_subprog_arg_match() | |
6782 | * because btf_check_func_arg_match() is still doing both. Once that | |
6783 | * function is split in 2, we can call from here btf_check_subprog_arg_match() | |
6784 | * first, and then treat the calling part in a new code path. | |
6785 | */ | |
6786 | int btf_check_subprog_call(struct bpf_verifier_env *env, int subprog, | |
6787 | struct bpf_reg_state *regs) | |
6788 | { | |
6789 | struct bpf_prog *prog = env->prog; | |
6790 | struct btf *btf = prog->aux->btf; | |
6791 | bool is_global; | |
6792 | u32 btf_id; | |
6793 | int err; | |
6794 | ||
6795 | if (!prog->aux->func_info) | |
6796 | return -EINVAL; | |
6797 | ||
6798 | btf_id = prog->aux->func_info[subprog].type_id; | |
6799 | if (!btf_id) | |
6800 | return -EFAULT; | |
6801 | ||
6802 | if (prog->aux->func_info_aux[subprog].unreliable) | |
6803 | return -EINVAL; | |
6804 | ||
6805 | is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL; | |
00b85860 | 6806 | err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, true); |
34747c41 | 6807 | |
51c39bb1 AS |
6808 | /* Compiler optimizations can remove arguments from static functions |
6809 | * or mismatched type can be passed into a global function. | |
6810 | * In such cases mark the function as unreliable from BTF point of view. | |
6811 | */ | |
34747c41 MKL |
6812 | if (err) |
6813 | prog->aux->func_info_aux[subprog].unreliable = true; | |
6814 | return err; | |
51c39bb1 AS |
6815 | } |
6816 | ||
6817 | /* Convert BTF of a function into bpf_reg_state if possible | |
6818 | * Returns: | |
6819 | * EFAULT - there is a verifier bug. Abort verification. | |
6820 | * EINVAL - cannot convert BTF. | |
6821 | * 0 - Successfully converted BTF into bpf_reg_state | |
6822 | * (either PTR_TO_CTX or SCALAR_VALUE). | |
6823 | */ | |
6824 | int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog, | |
feb4adfa | 6825 | struct bpf_reg_state *regs) |
51c39bb1 AS |
6826 | { |
6827 | struct bpf_verifier_log *log = &env->log; | |
6828 | struct bpf_prog *prog = env->prog; | |
be8704ff | 6829 | enum bpf_prog_type prog_type = prog->type; |
51c39bb1 AS |
6830 | struct btf *btf = prog->aux->btf; |
6831 | const struct btf_param *args; | |
e5069b9c | 6832 | const struct btf_type *t, *ref_t; |
51c39bb1 AS |
6833 | u32 i, nargs, btf_id; |
6834 | const char *tname; | |
6835 | ||
6836 | if (!prog->aux->func_info || | |
6837 | prog->aux->func_info_aux[subprog].linkage != BTF_FUNC_GLOBAL) { | |
6838 | bpf_log(log, "Verifier bug\n"); | |
6839 | return -EFAULT; | |
6840 | } | |
6841 | ||
6842 | btf_id = prog->aux->func_info[subprog].type_id; | |
6843 | if (!btf_id) { | |
6844 | bpf_log(log, "Global functions need valid BTF\n"); | |
6845 | return -EFAULT; | |
6846 | } | |
6847 | ||
6848 | t = btf_type_by_id(btf, btf_id); | |
6849 | if (!t || !btf_type_is_func(t)) { | |
6850 | /* These checks were already done by the verifier while loading | |
6851 | * struct bpf_func_info | |
6852 | */ | |
6853 | bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n", | |
6854 | subprog); | |
6855 | return -EFAULT; | |
6856 | } | |
6857 | tname = btf_name_by_offset(btf, t->name_off); | |
6858 | ||
6859 | if (log->level & BPF_LOG_LEVEL) | |
6860 | bpf_log(log, "Validating %s() func#%d...\n", | |
6861 | tname, subprog); | |
6862 | ||
6863 | if (prog->aux->func_info_aux[subprog].unreliable) { | |
6864 | bpf_log(log, "Verifier bug in function %s()\n", tname); | |
6865 | return -EFAULT; | |
6866 | } | |
be8704ff | 6867 | if (prog_type == BPF_PROG_TYPE_EXT) |
3aac1ead | 6868 | prog_type = prog->aux->dst_prog->type; |
51c39bb1 AS |
6869 | |
6870 | t = btf_type_by_id(btf, t->type); | |
6871 | if (!t || !btf_type_is_func_proto(t)) { | |
6872 | bpf_log(log, "Invalid type of function %s()\n", tname); | |
6873 | return -EFAULT; | |
6874 | } | |
6875 | args = (const struct btf_param *)(t + 1); | |
6876 | nargs = btf_type_vlen(t); | |
523a4cf4 DB |
6877 | if (nargs > MAX_BPF_FUNC_REG_ARGS) { |
6878 | bpf_log(log, "Global function %s() with %d > %d args. Buggy compiler.\n", | |
6879 | tname, nargs, MAX_BPF_FUNC_REG_ARGS); | |
51c39bb1 AS |
6880 | return -EINVAL; |
6881 | } | |
6882 | /* check that function returns int */ | |
6883 | t = btf_type_by_id(btf, t->type); | |
6884 | while (btf_type_is_modifier(t)) | |
6885 | t = btf_type_by_id(btf, t->type); | |
6089fb32 | 6886 | if (!btf_type_is_int(t) && !btf_is_any_enum(t)) { |
51c39bb1 AS |
6887 | bpf_log(log, |
6888 | "Global function %s() doesn't return scalar. Only those are supported.\n", | |
6889 | tname); | |
6890 | return -EINVAL; | |
6891 | } | |
6892 | /* Convert BTF function arguments into verifier types. | |
6893 | * Only PTR_TO_CTX and SCALAR are supported atm. | |
6894 | */ | |
6895 | for (i = 0; i < nargs; i++) { | |
feb4adfa DB |
6896 | struct bpf_reg_state *reg = ®s[i + 1]; |
6897 | ||
51c39bb1 AS |
6898 | t = btf_type_by_id(btf, args[i].type); |
6899 | while (btf_type_is_modifier(t)) | |
6900 | t = btf_type_by_id(btf, t->type); | |
6089fb32 | 6901 | if (btf_type_is_int(t) || btf_is_any_enum(t)) { |
feb4adfa | 6902 | reg->type = SCALAR_VALUE; |
51c39bb1 AS |
6903 | continue; |
6904 | } | |
e5069b9c DB |
6905 | if (btf_type_is_ptr(t)) { |
6906 | if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) { | |
6907 | reg->type = PTR_TO_CTX; | |
6908 | continue; | |
6909 | } | |
6910 | ||
6911 | t = btf_type_skip_modifiers(btf, t->type, NULL); | |
6912 | ||
6913 | ref_t = btf_resolve_size(btf, t, ®->mem_size); | |
6914 | if (IS_ERR(ref_t)) { | |
6915 | bpf_log(log, | |
6916 | "arg#%d reference type('%s %s') size cannot be determined: %ld\n", | |
6917 | i, btf_type_str(t), btf_name_by_offset(btf, t->name_off), | |
6918 | PTR_ERR(ref_t)); | |
6919 | return -EINVAL; | |
6920 | } | |
6921 | ||
cf9f2f8d | 6922 | reg->type = PTR_TO_MEM | PTR_MAYBE_NULL; |
e5069b9c DB |
6923 | reg->id = ++env->id_gen; |
6924 | ||
51c39bb1 AS |
6925 | continue; |
6926 | } | |
6927 | bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n", | |
571f9738 | 6928 | i, btf_type_str(t), tname); |
51c39bb1 AS |
6929 | return -EINVAL; |
6930 | } | |
8c1b6e69 AS |
6931 | return 0; |
6932 | } | |
6933 | ||
31d0bc81 AM |
6934 | static void btf_type_show(const struct btf *btf, u32 type_id, void *obj, |
6935 | struct btf_show *show) | |
6936 | { | |
6937 | const struct btf_type *t = btf_type_by_id(btf, type_id); | |
6938 | ||
6939 | show->btf = btf; | |
6940 | memset(&show->state, 0, sizeof(show->state)); | |
6941 | memset(&show->obj, 0, sizeof(show->obj)); | |
6942 | ||
6943 | btf_type_ops(t)->show(btf, t, type_id, obj, 0, show); | |
6944 | } | |
6945 | ||
6946 | static void btf_seq_show(struct btf_show *show, const char *fmt, | |
6947 | va_list args) | |
6948 | { | |
6949 | seq_vprintf((struct seq_file *)show->target, fmt, args); | |
6950 | } | |
6951 | ||
eb411377 AM |
6952 | int btf_type_seq_show_flags(const struct btf *btf, u32 type_id, |
6953 | void *obj, struct seq_file *m, u64 flags) | |
31d0bc81 AM |
6954 | { |
6955 | struct btf_show sseq; | |
6956 | ||
6957 | sseq.target = m; | |
6958 | sseq.showfn = btf_seq_show; | |
6959 | sseq.flags = flags; | |
6960 | ||
6961 | btf_type_show(btf, type_id, obj, &sseq); | |
6962 | ||
6963 | return sseq.state.status; | |
6964 | } | |
6965 | ||
b00b8dae MKL |
6966 | void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj, |
6967 | struct seq_file *m) | |
6968 | { | |
31d0bc81 AM |
6969 | (void) btf_type_seq_show_flags(btf, type_id, obj, m, |
6970 | BTF_SHOW_NONAME | BTF_SHOW_COMPACT | | |
6971 | BTF_SHOW_ZERO | BTF_SHOW_UNSAFE); | |
6972 | } | |
6973 | ||
6974 | struct btf_show_snprintf { | |
6975 | struct btf_show show; | |
6976 | int len_left; /* space left in string */ | |
6977 | int len; /* length we would have written */ | |
6978 | }; | |
6979 | ||
6980 | static void btf_snprintf_show(struct btf_show *show, const char *fmt, | |
6981 | va_list args) | |
6982 | { | |
6983 | struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show; | |
6984 | int len; | |
6985 | ||
6986 | len = vsnprintf(show->target, ssnprintf->len_left, fmt, args); | |
6987 | ||
6988 | if (len < 0) { | |
6989 | ssnprintf->len_left = 0; | |
6990 | ssnprintf->len = len; | |
58250ae3 | 6991 | } else if (len >= ssnprintf->len_left) { |
31d0bc81 AM |
6992 | /* no space, drive on to get length we would have written */ |
6993 | ssnprintf->len_left = 0; | |
6994 | ssnprintf->len += len; | |
6995 | } else { | |
6996 | ssnprintf->len_left -= len; | |
6997 | ssnprintf->len += len; | |
6998 | show->target += len; | |
6999 | } | |
7000 | } | |
7001 | ||
7002 | int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj, | |
7003 | char *buf, int len, u64 flags) | |
7004 | { | |
7005 | struct btf_show_snprintf ssnprintf; | |
7006 | ||
7007 | ssnprintf.show.target = buf; | |
7008 | ssnprintf.show.flags = flags; | |
7009 | ssnprintf.show.showfn = btf_snprintf_show; | |
7010 | ssnprintf.len_left = len; | |
7011 | ssnprintf.len = 0; | |
7012 | ||
7013 | btf_type_show(btf, type_id, obj, (struct btf_show *)&ssnprintf); | |
7014 | ||
c561d110 | 7015 | /* If we encountered an error, return it. */ |
31d0bc81 AM |
7016 | if (ssnprintf.show.state.status) |
7017 | return ssnprintf.show.state.status; | |
b00b8dae | 7018 | |
31d0bc81 AM |
7019 | /* Otherwise return length we would have written */ |
7020 | return ssnprintf.len; | |
b00b8dae | 7021 | } |
f56a653c | 7022 | |
3481e64b QM |
7023 | #ifdef CONFIG_PROC_FS |
7024 | static void bpf_btf_show_fdinfo(struct seq_file *m, struct file *filp) | |
7025 | { | |
7026 | const struct btf *btf = filp->private_data; | |
7027 | ||
7028 | seq_printf(m, "btf_id:\t%u\n", btf->id); | |
7029 | } | |
7030 | #endif | |
7031 | ||
f56a653c MKL |
7032 | static int btf_release(struct inode *inode, struct file *filp) |
7033 | { | |
7034 | btf_put(filp->private_data); | |
7035 | return 0; | |
7036 | } | |
7037 | ||
60197cfb | 7038 | const struct file_operations btf_fops = { |
3481e64b QM |
7039 | #ifdef CONFIG_PROC_FS |
7040 | .show_fdinfo = bpf_btf_show_fdinfo, | |
7041 | #endif | |
f56a653c MKL |
7042 | .release = btf_release, |
7043 | }; | |
7044 | ||
78958fca MKL |
7045 | static int __btf_new_fd(struct btf *btf) |
7046 | { | |
7047 | return anon_inode_getfd("btf", &btf_fops, btf, O_RDONLY | O_CLOEXEC); | |
7048 | } | |
7049 | ||
c571bd75 | 7050 | int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr) |
f56a653c MKL |
7051 | { |
7052 | struct btf *btf; | |
78958fca | 7053 | int ret; |
f56a653c | 7054 | |
c571bd75 | 7055 | btf = btf_parse(make_bpfptr(attr->btf, uattr.is_kernel), |
f56a653c MKL |
7056 | attr->btf_size, attr->btf_log_level, |
7057 | u64_to_user_ptr(attr->btf_log_buf), | |
7058 | attr->btf_log_size); | |
7059 | if (IS_ERR(btf)) | |
7060 | return PTR_ERR(btf); | |
7061 | ||
78958fca MKL |
7062 | ret = btf_alloc_id(btf); |
7063 | if (ret) { | |
7064 | btf_free(btf); | |
7065 | return ret; | |
7066 | } | |
7067 | ||
7068 | /* | |
7069 | * The BTF ID is published to the userspace. | |
7070 | * All BTF free must go through call_rcu() from | |
7071 | * now on (i.e. free by calling btf_put()). | |
7072 | */ | |
7073 | ||
7074 | ret = __btf_new_fd(btf); | |
7075 | if (ret < 0) | |
f56a653c MKL |
7076 | btf_put(btf); |
7077 | ||
78958fca | 7078 | return ret; |
f56a653c MKL |
7079 | } |
7080 | ||
7081 | struct btf *btf_get_by_fd(int fd) | |
7082 | { | |
7083 | struct btf *btf; | |
7084 | struct fd f; | |
7085 | ||
7086 | f = fdget(fd); | |
7087 | ||
7088 | if (!f.file) | |
7089 | return ERR_PTR(-EBADF); | |
7090 | ||
7091 | if (f.file->f_op != &btf_fops) { | |
7092 | fdput(f); | |
7093 | return ERR_PTR(-EINVAL); | |
7094 | } | |
7095 | ||
7096 | btf = f.file->private_data; | |
78958fca | 7097 | refcount_inc(&btf->refcnt); |
f56a653c MKL |
7098 | fdput(f); |
7099 | ||
7100 | return btf; | |
7101 | } | |
60197cfb MKL |
7102 | |
7103 | int btf_get_info_by_fd(const struct btf *btf, | |
7104 | const union bpf_attr *attr, | |
7105 | union bpf_attr __user *uattr) | |
7106 | { | |
62dab84c | 7107 | struct bpf_btf_info __user *uinfo; |
5c6f2588 | 7108 | struct bpf_btf_info info; |
62dab84c MKL |
7109 | u32 info_copy, btf_copy; |
7110 | void __user *ubtf; | |
53297220 AN |
7111 | char __user *uname; |
7112 | u32 uinfo_len, uname_len, name_len; | |
7113 | int ret = 0; | |
60197cfb | 7114 | |
62dab84c MKL |
7115 | uinfo = u64_to_user_ptr(attr->info.info); |
7116 | uinfo_len = attr->info.info_len; | |
7117 | ||
7118 | info_copy = min_t(u32, uinfo_len, sizeof(info)); | |
5c6f2588 | 7119 | memset(&info, 0, sizeof(info)); |
62dab84c MKL |
7120 | if (copy_from_user(&info, uinfo, info_copy)) |
7121 | return -EFAULT; | |
7122 | ||
7123 | info.id = btf->id; | |
7124 | ubtf = u64_to_user_ptr(info.btf); | |
7125 | btf_copy = min_t(u32, btf->data_size, info.btf_size); | |
7126 | if (copy_to_user(ubtf, btf->data, btf_copy)) | |
7127 | return -EFAULT; | |
7128 | info.btf_size = btf->data_size; | |
7129 | ||
53297220 AN |
7130 | info.kernel_btf = btf->kernel_btf; |
7131 | ||
7132 | uname = u64_to_user_ptr(info.name); | |
7133 | uname_len = info.name_len; | |
7134 | if (!uname ^ !uname_len) | |
7135 | return -EINVAL; | |
7136 | ||
7137 | name_len = strlen(btf->name); | |
7138 | info.name_len = name_len; | |
7139 | ||
7140 | if (uname) { | |
7141 | if (uname_len >= name_len + 1) { | |
7142 | if (copy_to_user(uname, btf->name, name_len + 1)) | |
7143 | return -EFAULT; | |
7144 | } else { | |
7145 | char zero = '\0'; | |
7146 | ||
7147 | if (copy_to_user(uname, btf->name, uname_len - 1)) | |
7148 | return -EFAULT; | |
7149 | if (put_user(zero, uname + uname_len - 1)) | |
7150 | return -EFAULT; | |
7151 | /* let user-space know about too short buffer */ | |
7152 | ret = -ENOSPC; | |
7153 | } | |
7154 | } | |
7155 | ||
62dab84c MKL |
7156 | if (copy_to_user(uinfo, &info, info_copy) || |
7157 | put_user(info_copy, &uattr->info.info_len)) | |
60197cfb MKL |
7158 | return -EFAULT; |
7159 | ||
53297220 | 7160 | return ret; |
60197cfb | 7161 | } |
78958fca MKL |
7162 | |
7163 | int btf_get_fd_by_id(u32 id) | |
7164 | { | |
7165 | struct btf *btf; | |
7166 | int fd; | |
7167 | ||
7168 | rcu_read_lock(); | |
7169 | btf = idr_find(&btf_idr, id); | |
7170 | if (!btf || !refcount_inc_not_zero(&btf->refcnt)) | |
7171 | btf = ERR_PTR(-ENOENT); | |
7172 | rcu_read_unlock(); | |
7173 | ||
7174 | if (IS_ERR(btf)) | |
7175 | return PTR_ERR(btf); | |
7176 | ||
7177 | fd = __btf_new_fd(btf); | |
7178 | if (fd < 0) | |
7179 | btf_put(btf); | |
7180 | ||
7181 | return fd; | |
7182 | } | |
7183 | ||
22dc4a0f | 7184 | u32 btf_obj_id(const struct btf *btf) |
78958fca MKL |
7185 | { |
7186 | return btf->id; | |
7187 | } | |
eae2e83e | 7188 | |
290248a5 AN |
7189 | bool btf_is_kernel(const struct btf *btf) |
7190 | { | |
7191 | return btf->kernel_btf; | |
7192 | } | |
7193 | ||
541c3bad AN |
7194 | bool btf_is_module(const struct btf *btf) |
7195 | { | |
7196 | return btf->kernel_btf && strcmp(btf->name, "vmlinux") != 0; | |
7197 | } | |
7198 | ||
18688de2 KKD |
7199 | enum { |
7200 | BTF_MODULE_F_LIVE = (1 << 0), | |
7201 | }; | |
7202 | ||
36e68442 AN |
7203 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
7204 | struct btf_module { | |
7205 | struct list_head list; | |
7206 | struct module *module; | |
7207 | struct btf *btf; | |
7208 | struct bin_attribute *sysfs_attr; | |
18688de2 | 7209 | int flags; |
36e68442 AN |
7210 | }; |
7211 | ||
7212 | static LIST_HEAD(btf_modules); | |
7213 | static DEFINE_MUTEX(btf_module_mutex); | |
7214 | ||
7215 | static ssize_t | |
7216 | btf_module_read(struct file *file, struct kobject *kobj, | |
7217 | struct bin_attribute *bin_attr, | |
7218 | char *buf, loff_t off, size_t len) | |
7219 | { | |
7220 | const struct btf *btf = bin_attr->private; | |
7221 | ||
7222 | memcpy(buf, btf->data + off, len); | |
7223 | return len; | |
7224 | } | |
7225 | ||
1e89106d AS |
7226 | static void purge_cand_cache(struct btf *btf); |
7227 | ||
36e68442 AN |
7228 | static int btf_module_notify(struct notifier_block *nb, unsigned long op, |
7229 | void *module) | |
7230 | { | |
7231 | struct btf_module *btf_mod, *tmp; | |
7232 | struct module *mod = module; | |
7233 | struct btf *btf; | |
7234 | int err = 0; | |
7235 | ||
7236 | if (mod->btf_data_size == 0 || | |
18688de2 KKD |
7237 | (op != MODULE_STATE_COMING && op != MODULE_STATE_LIVE && |
7238 | op != MODULE_STATE_GOING)) | |
36e68442 AN |
7239 | goto out; |
7240 | ||
7241 | switch (op) { | |
7242 | case MODULE_STATE_COMING: | |
7243 | btf_mod = kzalloc(sizeof(*btf_mod), GFP_KERNEL); | |
7244 | if (!btf_mod) { | |
7245 | err = -ENOMEM; | |
7246 | goto out; | |
7247 | } | |
7248 | btf = btf_parse_module(mod->name, mod->btf_data, mod->btf_data_size); | |
7249 | if (IS_ERR(btf)) { | |
7250 | pr_warn("failed to validate module [%s] BTF: %ld\n", | |
7251 | mod->name, PTR_ERR(btf)); | |
7252 | kfree(btf_mod); | |
5e214f2e CB |
7253 | if (!IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) |
7254 | err = PTR_ERR(btf); | |
36e68442 AN |
7255 | goto out; |
7256 | } | |
7257 | err = btf_alloc_id(btf); | |
7258 | if (err) { | |
7259 | btf_free(btf); | |
7260 | kfree(btf_mod); | |
7261 | goto out; | |
7262 | } | |
7263 | ||
1e89106d | 7264 | purge_cand_cache(NULL); |
36e68442 AN |
7265 | mutex_lock(&btf_module_mutex); |
7266 | btf_mod->module = module; | |
7267 | btf_mod->btf = btf; | |
7268 | list_add(&btf_mod->list, &btf_modules); | |
7269 | mutex_unlock(&btf_module_mutex); | |
7270 | ||
7271 | if (IS_ENABLED(CONFIG_SYSFS)) { | |
7272 | struct bin_attribute *attr; | |
7273 | ||
7274 | attr = kzalloc(sizeof(*attr), GFP_KERNEL); | |
7275 | if (!attr) | |
7276 | goto out; | |
7277 | ||
7278 | sysfs_bin_attr_init(attr); | |
7279 | attr->attr.name = btf->name; | |
7280 | attr->attr.mode = 0444; | |
7281 | attr->size = btf->data_size; | |
7282 | attr->private = btf; | |
7283 | attr->read = btf_module_read; | |
7284 | ||
7285 | err = sysfs_create_bin_file(btf_kobj, attr); | |
7286 | if (err) { | |
7287 | pr_warn("failed to register module [%s] BTF in sysfs: %d\n", | |
7288 | mod->name, err); | |
7289 | kfree(attr); | |
7290 | err = 0; | |
7291 | goto out; | |
7292 | } | |
7293 | ||
7294 | btf_mod->sysfs_attr = attr; | |
7295 | } | |
7296 | ||
18688de2 KKD |
7297 | break; |
7298 | case MODULE_STATE_LIVE: | |
7299 | mutex_lock(&btf_module_mutex); | |
7300 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
7301 | if (btf_mod->module != module) | |
7302 | continue; | |
7303 | ||
7304 | btf_mod->flags |= BTF_MODULE_F_LIVE; | |
7305 | break; | |
7306 | } | |
7307 | mutex_unlock(&btf_module_mutex); | |
36e68442 AN |
7308 | break; |
7309 | case MODULE_STATE_GOING: | |
7310 | mutex_lock(&btf_module_mutex); | |
7311 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
7312 | if (btf_mod->module != module) | |
7313 | continue; | |
7314 | ||
7315 | list_del(&btf_mod->list); | |
7316 | if (btf_mod->sysfs_attr) | |
7317 | sysfs_remove_bin_file(btf_kobj, btf_mod->sysfs_attr); | |
1e89106d | 7318 | purge_cand_cache(btf_mod->btf); |
36e68442 AN |
7319 | btf_put(btf_mod->btf); |
7320 | kfree(btf_mod->sysfs_attr); | |
7321 | kfree(btf_mod); | |
7322 | break; | |
7323 | } | |
7324 | mutex_unlock(&btf_module_mutex); | |
7325 | break; | |
7326 | } | |
7327 | out: | |
7328 | return notifier_from_errno(err); | |
7329 | } | |
7330 | ||
7331 | static struct notifier_block btf_module_nb = { | |
7332 | .notifier_call = btf_module_notify, | |
7333 | }; | |
7334 | ||
7335 | static int __init btf_module_init(void) | |
7336 | { | |
7337 | register_module_notifier(&btf_module_nb); | |
7338 | return 0; | |
7339 | } | |
7340 | ||
7341 | fs_initcall(btf_module_init); | |
7342 | #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */ | |
541c3bad AN |
7343 | |
7344 | struct module *btf_try_get_module(const struct btf *btf) | |
7345 | { | |
7346 | struct module *res = NULL; | |
7347 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES | |
7348 | struct btf_module *btf_mod, *tmp; | |
7349 | ||
7350 | mutex_lock(&btf_module_mutex); | |
7351 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
7352 | if (btf_mod->btf != btf) | |
7353 | continue; | |
7354 | ||
18688de2 KKD |
7355 | /* We must only consider module whose __init routine has |
7356 | * finished, hence we must check for BTF_MODULE_F_LIVE flag, | |
7357 | * which is set from the notifier callback for | |
7358 | * MODULE_STATE_LIVE. | |
7359 | */ | |
7360 | if ((btf_mod->flags & BTF_MODULE_F_LIVE) && try_module_get(btf_mod->module)) | |
541c3bad AN |
7361 | res = btf_mod->module; |
7362 | ||
7363 | break; | |
7364 | } | |
7365 | mutex_unlock(&btf_module_mutex); | |
7366 | #endif | |
7367 | ||
7368 | return res; | |
7369 | } | |
3d78417b | 7370 | |
9492450f KKD |
7371 | /* Returns struct btf corresponding to the struct module. |
7372 | * This function can return NULL or ERR_PTR. | |
dee872e1 KKD |
7373 | */ |
7374 | static struct btf *btf_get_module_btf(const struct module *module) | |
7375 | { | |
dee872e1 KKD |
7376 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
7377 | struct btf_module *btf_mod, *tmp; | |
7378 | #endif | |
9492450f KKD |
7379 | struct btf *btf = NULL; |
7380 | ||
7381 | if (!module) { | |
7382 | btf = bpf_get_btf_vmlinux(); | |
7ada3787 | 7383 | if (!IS_ERR_OR_NULL(btf)) |
9492450f KKD |
7384 | btf_get(btf); |
7385 | return btf; | |
7386 | } | |
dee872e1 | 7387 | |
dee872e1 KKD |
7388 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
7389 | mutex_lock(&btf_module_mutex); | |
7390 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
7391 | if (btf_mod->module != module) | |
7392 | continue; | |
7393 | ||
7394 | btf_get(btf_mod->btf); | |
7395 | btf = btf_mod->btf; | |
7396 | break; | |
7397 | } | |
7398 | mutex_unlock(&btf_module_mutex); | |
7399 | #endif | |
7400 | ||
7401 | return btf; | |
7402 | } | |
7403 | ||
3d78417b AS |
7404 | BPF_CALL_4(bpf_btf_find_by_name_kind, char *, name, int, name_sz, u32, kind, int, flags) |
7405 | { | |
edc3ec09 KKD |
7406 | struct btf *btf = NULL; |
7407 | int btf_obj_fd = 0; | |
3d78417b AS |
7408 | long ret; |
7409 | ||
7410 | if (flags) | |
7411 | return -EINVAL; | |
7412 | ||
7413 | if (name_sz <= 1 || name[name_sz - 1]) | |
7414 | return -EINVAL; | |
7415 | ||
edc3ec09 KKD |
7416 | ret = bpf_find_btf_id(name, kind, &btf); |
7417 | if (ret > 0 && btf_is_module(btf)) { | |
7418 | btf_obj_fd = __btf_new_fd(btf); | |
7419 | if (btf_obj_fd < 0) { | |
7420 | btf_put(btf); | |
7421 | return btf_obj_fd; | |
3d78417b | 7422 | } |
edc3ec09 | 7423 | return ret | (((u64)btf_obj_fd) << 32); |
3d78417b | 7424 | } |
edc3ec09 KKD |
7425 | if (ret > 0) |
7426 | btf_put(btf); | |
3d78417b AS |
7427 | return ret; |
7428 | } | |
7429 | ||
7430 | const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = { | |
7431 | .func = bpf_btf_find_by_name_kind, | |
7432 | .gpl_only = false, | |
7433 | .ret_type = RET_INTEGER, | |
216e3cd2 | 7434 | .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
3d78417b AS |
7435 | .arg2_type = ARG_CONST_SIZE, |
7436 | .arg3_type = ARG_ANYTHING, | |
7437 | .arg4_type = ARG_ANYTHING, | |
7438 | }; | |
eb529c5b | 7439 | |
d19ddb47 SL |
7440 | BTF_ID_LIST_GLOBAL(btf_tracing_ids, MAX_BTF_TRACING_TYPE) |
7441 | #define BTF_TRACING_TYPE(name, type) BTF_ID(struct, type) | |
7442 | BTF_TRACING_TYPE_xxx | |
7443 | #undef BTF_TRACING_TYPE | |
14f267d9 | 7444 | |
dee872e1 | 7445 | /* Kernel Function (kfunc) BTF ID set registration API */ |
14f267d9 | 7446 | |
a4703e31 KKD |
7447 | static int btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, |
7448 | struct btf_id_set8 *add_set) | |
14f267d9 | 7449 | { |
a4703e31 | 7450 | bool vmlinux_set = !btf_is_module(btf); |
dee872e1 | 7451 | struct btf_kfunc_set_tab *tab; |
a4703e31 | 7452 | struct btf_id_set8 *set; |
dee872e1 KKD |
7453 | u32 set_cnt; |
7454 | int ret; | |
7455 | ||
a4703e31 | 7456 | if (hook >= BTF_KFUNC_HOOK_MAX) { |
dee872e1 KKD |
7457 | ret = -EINVAL; |
7458 | goto end; | |
7459 | } | |
7460 | ||
7461 | if (!add_set->cnt) | |
7462 | return 0; | |
7463 | ||
7464 | tab = btf->kfunc_set_tab; | |
7465 | if (!tab) { | |
7466 | tab = kzalloc(sizeof(*tab), GFP_KERNEL | __GFP_NOWARN); | |
7467 | if (!tab) | |
7468 | return -ENOMEM; | |
7469 | btf->kfunc_set_tab = tab; | |
7470 | } | |
7471 | ||
a4703e31 | 7472 | set = tab->sets[hook]; |
dee872e1 KKD |
7473 | /* Warn when register_btf_kfunc_id_set is called twice for the same hook |
7474 | * for module sets. | |
7475 | */ | |
7476 | if (WARN_ON_ONCE(set && !vmlinux_set)) { | |
7477 | ret = -EINVAL; | |
7478 | goto end; | |
7479 | } | |
7480 | ||
7481 | /* We don't need to allocate, concatenate, and sort module sets, because | |
7482 | * only one is allowed per hook. Hence, we can directly assign the | |
7483 | * pointer and return. | |
7484 | */ | |
7485 | if (!vmlinux_set) { | |
a4703e31 | 7486 | tab->sets[hook] = add_set; |
dee872e1 KKD |
7487 | return 0; |
7488 | } | |
7489 | ||
7490 | /* In case of vmlinux sets, there may be more than one set being | |
7491 | * registered per hook. To create a unified set, we allocate a new set | |
7492 | * and concatenate all individual sets being registered. While each set | |
7493 | * is individually sorted, they may become unsorted when concatenated, | |
7494 | * hence re-sorting the final set again is required to make binary | |
a4703e31 | 7495 | * searching the set using btf_id_set8_contains function work. |
dee872e1 KKD |
7496 | */ |
7497 | set_cnt = set ? set->cnt : 0; | |
7498 | ||
7499 | if (set_cnt > U32_MAX - add_set->cnt) { | |
7500 | ret = -EOVERFLOW; | |
7501 | goto end; | |
7502 | } | |
7503 | ||
7504 | if (set_cnt + add_set->cnt > BTF_KFUNC_SET_MAX_CNT) { | |
7505 | ret = -E2BIG; | |
7506 | goto end; | |
7507 | } | |
7508 | ||
7509 | /* Grow set */ | |
a4703e31 KKD |
7510 | set = krealloc(tab->sets[hook], |
7511 | offsetof(struct btf_id_set8, pairs[set_cnt + add_set->cnt]), | |
dee872e1 KKD |
7512 | GFP_KERNEL | __GFP_NOWARN); |
7513 | if (!set) { | |
7514 | ret = -ENOMEM; | |
7515 | goto end; | |
7516 | } | |
7517 | ||
7518 | /* For newly allocated set, initialize set->cnt to 0 */ | |
a4703e31 | 7519 | if (!tab->sets[hook]) |
dee872e1 | 7520 | set->cnt = 0; |
a4703e31 | 7521 | tab->sets[hook] = set; |
dee872e1 KKD |
7522 | |
7523 | /* Concatenate the two sets */ | |
a4703e31 | 7524 | memcpy(set->pairs + set->cnt, add_set->pairs, add_set->cnt * sizeof(set->pairs[0])); |
dee872e1 KKD |
7525 | set->cnt += add_set->cnt; |
7526 | ||
a4703e31 | 7527 | sort(set->pairs, set->cnt, sizeof(set->pairs[0]), btf_id_cmp_func, NULL); |
dee872e1 KKD |
7528 | |
7529 | return 0; | |
7530 | end: | |
7531 | btf_free_kfunc_set_tab(btf); | |
7532 | return ret; | |
14f267d9 | 7533 | } |
14f267d9 | 7534 | |
a4703e31 | 7535 | static u32 *__btf_kfunc_id_set_contains(const struct btf *btf, |
dee872e1 | 7536 | enum btf_kfunc_hook hook, |
dee872e1 | 7537 | u32 kfunc_btf_id) |
14f267d9 | 7538 | { |
a4703e31 KKD |
7539 | struct btf_id_set8 *set; |
7540 | u32 *id; | |
14f267d9 | 7541 | |
a4703e31 KKD |
7542 | if (hook >= BTF_KFUNC_HOOK_MAX) |
7543 | return NULL; | |
dee872e1 | 7544 | if (!btf->kfunc_set_tab) |
a4703e31 KKD |
7545 | return NULL; |
7546 | set = btf->kfunc_set_tab->sets[hook]; | |
dee872e1 | 7547 | if (!set) |
a4703e31 KKD |
7548 | return NULL; |
7549 | id = btf_id_set8_contains(set, kfunc_btf_id); | |
7550 | if (!id) | |
7551 | return NULL; | |
7552 | /* The flags for BTF ID are located next to it */ | |
7553 | return id + 1; | |
dee872e1 KKD |
7554 | } |
7555 | ||
7556 | static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type) | |
7557 | { | |
7558 | switch (prog_type) { | |
cfe14564 YS |
7559 | case BPF_PROG_TYPE_UNSPEC: |
7560 | return BTF_KFUNC_HOOK_COMMON; | |
dee872e1 KKD |
7561 | case BPF_PROG_TYPE_XDP: |
7562 | return BTF_KFUNC_HOOK_XDP; | |
7563 | case BPF_PROG_TYPE_SCHED_CLS: | |
7564 | return BTF_KFUNC_HOOK_TC; | |
7565 | case BPF_PROG_TYPE_STRUCT_OPS: | |
7566 | return BTF_KFUNC_HOOK_STRUCT_OPS; | |
97949767 | 7567 | case BPF_PROG_TYPE_TRACING: |
d15bf150 | 7568 | case BPF_PROG_TYPE_LSM: |
97949767 BT |
7569 | return BTF_KFUNC_HOOK_TRACING; |
7570 | case BPF_PROG_TYPE_SYSCALL: | |
7571 | return BTF_KFUNC_HOOK_SYSCALL; | |
dee872e1 KKD |
7572 | default: |
7573 | return BTF_KFUNC_HOOK_MAX; | |
14f267d9 | 7574 | } |
14f267d9 KKD |
7575 | } |
7576 | ||
dee872e1 KKD |
7577 | /* Caution: |
7578 | * Reference to the module (obtained using btf_try_get_module) corresponding to | |
7579 | * the struct btf *MUST* be held when calling this function from verifier | |
7580 | * context. This is usually true as we stash references in prog's kfunc_btf_tab; | |
7581 | * keeping the reference for the duration of the call provides the necessary | |
7582 | * protection for looking up a well-formed btf->kfunc_set_tab. | |
7583 | */ | |
a4703e31 | 7584 | u32 *btf_kfunc_id_set_contains(const struct btf *btf, |
dee872e1 | 7585 | enum bpf_prog_type prog_type, |
a4703e31 | 7586 | u32 kfunc_btf_id) |
dee872e1 KKD |
7587 | { |
7588 | enum btf_kfunc_hook hook; | |
cfe14564 YS |
7589 | u32 *kfunc_flags; |
7590 | ||
7591 | kfunc_flags = __btf_kfunc_id_set_contains(btf, BTF_KFUNC_HOOK_COMMON, kfunc_btf_id); | |
7592 | if (kfunc_flags) | |
7593 | return kfunc_flags; | |
0e32dfc8 | 7594 | |
dee872e1 | 7595 | hook = bpf_prog_type_to_kfunc_hook(prog_type); |
a4703e31 | 7596 | return __btf_kfunc_id_set_contains(btf, hook, kfunc_btf_id); |
dee872e1 | 7597 | } |
d9847eb8 | 7598 | |
dee872e1 KKD |
7599 | /* This function must be invoked only from initcalls/module init functions */ |
7600 | int register_btf_kfunc_id_set(enum bpf_prog_type prog_type, | |
7601 | const struct btf_kfunc_id_set *kset) | |
7602 | { | |
7603 | enum btf_kfunc_hook hook; | |
7604 | struct btf *btf; | |
7605 | int ret; | |
7606 | ||
7607 | btf = btf_get_module_btf(kset->owner); | |
c446fdac SF |
7608 | if (!btf) { |
7609 | if (!kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) { | |
7610 | pr_err("missing vmlinux BTF, cannot register kfuncs\n"); | |
7611 | return -ENOENT; | |
7612 | } | |
7613 | if (kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) { | |
7614 | pr_err("missing module BTF, cannot register kfuncs\n"); | |
7615 | return -ENOENT; | |
7616 | } | |
7617 | return 0; | |
7618 | } | |
7619 | if (IS_ERR(btf)) | |
7620 | return PTR_ERR(btf); | |
dee872e1 KKD |
7621 | |
7622 | hook = bpf_prog_type_to_kfunc_hook(prog_type); | |
a4703e31 | 7623 | ret = btf_populate_kfunc_set(btf, hook, kset->set); |
9492450f | 7624 | btf_put(btf); |
dee872e1 KKD |
7625 | return ret; |
7626 | } | |
7627 | EXPORT_SYMBOL_GPL(register_btf_kfunc_id_set); | |
be315829 | 7628 | |
5ce937d6 KKD |
7629 | s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id) |
7630 | { | |
7631 | struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab; | |
7632 | struct btf_id_dtor_kfunc *dtor; | |
7633 | ||
7634 | if (!tab) | |
7635 | return -ENOENT; | |
7636 | /* Even though the size of tab->dtors[0] is > sizeof(u32), we only need | |
7637 | * to compare the first u32 with btf_id, so we can reuse btf_id_cmp_func. | |
7638 | */ | |
7639 | BUILD_BUG_ON(offsetof(struct btf_id_dtor_kfunc, btf_id) != 0); | |
7640 | dtor = bsearch(&btf_id, tab->dtors, tab->cnt, sizeof(tab->dtors[0]), btf_id_cmp_func); | |
7641 | if (!dtor) | |
7642 | return -ENOENT; | |
7643 | return dtor->kfunc_btf_id; | |
7644 | } | |
7645 | ||
14a324f6 KKD |
7646 | static int btf_check_dtor_kfuncs(struct btf *btf, const struct btf_id_dtor_kfunc *dtors, u32 cnt) |
7647 | { | |
7648 | const struct btf_type *dtor_func, *dtor_func_proto, *t; | |
7649 | const struct btf_param *args; | |
7650 | s32 dtor_btf_id; | |
7651 | u32 nr_args, i; | |
7652 | ||
7653 | for (i = 0; i < cnt; i++) { | |
7654 | dtor_btf_id = dtors[i].kfunc_btf_id; | |
7655 | ||
7656 | dtor_func = btf_type_by_id(btf, dtor_btf_id); | |
7657 | if (!dtor_func || !btf_type_is_func(dtor_func)) | |
7658 | return -EINVAL; | |
7659 | ||
7660 | dtor_func_proto = btf_type_by_id(btf, dtor_func->type); | |
7661 | if (!dtor_func_proto || !btf_type_is_func_proto(dtor_func_proto)) | |
7662 | return -EINVAL; | |
7663 | ||
7664 | /* Make sure the prototype of the destructor kfunc is 'void func(type *)' */ | |
7665 | t = btf_type_by_id(btf, dtor_func_proto->type); | |
7666 | if (!t || !btf_type_is_void(t)) | |
7667 | return -EINVAL; | |
7668 | ||
7669 | nr_args = btf_type_vlen(dtor_func_proto); | |
7670 | if (nr_args != 1) | |
7671 | return -EINVAL; | |
7672 | args = btf_params(dtor_func_proto); | |
7673 | t = btf_type_by_id(btf, args[0].type); | |
7674 | /* Allow any pointer type, as width on targets Linux supports | |
7675 | * will be same for all pointer types (i.e. sizeof(void *)) | |
7676 | */ | |
7677 | if (!t || !btf_type_is_ptr(t)) | |
7678 | return -EINVAL; | |
7679 | } | |
7680 | return 0; | |
7681 | } | |
7682 | ||
5ce937d6 KKD |
7683 | /* This function must be invoked only from initcalls/module init functions */ |
7684 | int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_cnt, | |
7685 | struct module *owner) | |
7686 | { | |
7687 | struct btf_id_dtor_kfunc_tab *tab; | |
7688 | struct btf *btf; | |
7689 | u32 tab_cnt; | |
7690 | int ret; | |
7691 | ||
7692 | btf = btf_get_module_btf(owner); | |
7693 | if (!btf) { | |
7694 | if (!owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) { | |
7695 | pr_err("missing vmlinux BTF, cannot register dtor kfuncs\n"); | |
7696 | return -ENOENT; | |
7697 | } | |
7698 | if (owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) { | |
7699 | pr_err("missing module BTF, cannot register dtor kfuncs\n"); | |
7700 | return -ENOENT; | |
7701 | } | |
7702 | return 0; | |
7703 | } | |
7704 | if (IS_ERR(btf)) | |
7705 | return PTR_ERR(btf); | |
7706 | ||
7707 | if (add_cnt >= BTF_DTOR_KFUNC_MAX_CNT) { | |
7708 | pr_err("cannot register more than %d kfunc destructors\n", BTF_DTOR_KFUNC_MAX_CNT); | |
7709 | ret = -E2BIG; | |
7710 | goto end; | |
7711 | } | |
7712 | ||
14a324f6 KKD |
7713 | /* Ensure that the prototype of dtor kfuncs being registered is sane */ |
7714 | ret = btf_check_dtor_kfuncs(btf, dtors, add_cnt); | |
7715 | if (ret < 0) | |
7716 | goto end; | |
7717 | ||
5ce937d6 KKD |
7718 | tab = btf->dtor_kfunc_tab; |
7719 | /* Only one call allowed for modules */ | |
7720 | if (WARN_ON_ONCE(tab && btf_is_module(btf))) { | |
7721 | ret = -EINVAL; | |
7722 | goto end; | |
7723 | } | |
7724 | ||
7725 | tab_cnt = tab ? tab->cnt : 0; | |
7726 | if (tab_cnt > U32_MAX - add_cnt) { | |
7727 | ret = -EOVERFLOW; | |
7728 | goto end; | |
7729 | } | |
7730 | if (tab_cnt + add_cnt >= BTF_DTOR_KFUNC_MAX_CNT) { | |
7731 | pr_err("cannot register more than %d kfunc destructors\n", BTF_DTOR_KFUNC_MAX_CNT); | |
7732 | ret = -E2BIG; | |
7733 | goto end; | |
7734 | } | |
7735 | ||
7736 | tab = krealloc(btf->dtor_kfunc_tab, | |
7737 | offsetof(struct btf_id_dtor_kfunc_tab, dtors[tab_cnt + add_cnt]), | |
7738 | GFP_KERNEL | __GFP_NOWARN); | |
7739 | if (!tab) { | |
7740 | ret = -ENOMEM; | |
7741 | goto end; | |
7742 | } | |
7743 | ||
7744 | if (!btf->dtor_kfunc_tab) | |
7745 | tab->cnt = 0; | |
7746 | btf->dtor_kfunc_tab = tab; | |
7747 | ||
7748 | memcpy(tab->dtors + tab->cnt, dtors, add_cnt * sizeof(tab->dtors[0])); | |
7749 | tab->cnt += add_cnt; | |
7750 | ||
7751 | sort(tab->dtors, tab->cnt, sizeof(tab->dtors[0]), btf_id_cmp_func, NULL); | |
7752 | ||
7753 | return 0; | |
7754 | end: | |
7755 | btf_free_dtor_kfunc_tab(btf); | |
7756 | btf_put(btf); | |
7757 | return ret; | |
7758 | } | |
7759 | EXPORT_SYMBOL_GPL(register_btf_id_dtor_kfuncs); | |
7760 | ||
e70e13e7 MC |
7761 | #define MAX_TYPES_ARE_COMPAT_DEPTH 2 |
7762 | ||
e70e13e7 MC |
7763 | /* Check local and target types for compatibility. This check is used for |
7764 | * type-based CO-RE relocations and follow slightly different rules than | |
7765 | * field-based relocations. This function assumes that root types were already | |
7766 | * checked for name match. Beyond that initial root-level name check, names | |
7767 | * are completely ignored. Compatibility rules are as follows: | |
6089fb32 | 7768 | * - any two STRUCTs/UNIONs/FWDs/ENUMs/INTs/ENUM64s are considered compatible, but |
e70e13e7 MC |
7769 | * kind should match for local and target types (i.e., STRUCT is not |
7770 | * compatible with UNION); | |
6089fb32 | 7771 | * - for ENUMs/ENUM64s, the size is ignored; |
e70e13e7 MC |
7772 | * - for INT, size and signedness are ignored; |
7773 | * - for ARRAY, dimensionality is ignored, element types are checked for | |
7774 | * compatibility recursively; | |
7775 | * - CONST/VOLATILE/RESTRICT modifiers are ignored; | |
7776 | * - TYPEDEFs/PTRs are compatible if types they pointing to are compatible; | |
7777 | * - FUNC_PROTOs are compatible if they have compatible signature: same | |
7778 | * number of input args and compatible return and argument types. | |
7779 | * These rules are not set in stone and probably will be adjusted as we get | |
7780 | * more experience with using BPF CO-RE relocations. | |
7781 | */ | |
29db4bea AS |
7782 | int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, |
7783 | const struct btf *targ_btf, __u32 targ_id) | |
7784 | { | |
fd75733d | 7785 | return __bpf_core_types_are_compat(local_btf, local_id, targ_btf, targ_id, |
e70e13e7 | 7786 | MAX_TYPES_ARE_COMPAT_DEPTH); |
29db4bea AS |
7787 | } |
7788 | ||
ec6209c8 DM |
7789 | #define MAX_TYPES_MATCH_DEPTH 2 |
7790 | ||
7791 | int bpf_core_types_match(const struct btf *local_btf, u32 local_id, | |
7792 | const struct btf *targ_btf, u32 targ_id) | |
7793 | { | |
7794 | return __bpf_core_types_match(local_btf, local_id, targ_btf, targ_id, false, | |
7795 | MAX_TYPES_MATCH_DEPTH); | |
7796 | } | |
7797 | ||
29db4bea AS |
7798 | static bool bpf_core_is_flavor_sep(const char *s) |
7799 | { | |
7800 | /* check X___Y name pattern, where X and Y are not underscores */ | |
7801 | return s[0] != '_' && /* X */ | |
7802 | s[1] == '_' && s[2] == '_' && s[3] == '_' && /* ___ */ | |
7803 | s[4] != '_'; /* Y */ | |
7804 | } | |
7805 | ||
7806 | size_t bpf_core_essential_name_len(const char *name) | |
7807 | { | |
7808 | size_t n = strlen(name); | |
7809 | int i; | |
7810 | ||
7811 | for (i = n - 5; i >= 0; i--) { | |
7812 | if (bpf_core_is_flavor_sep(name + i)) | |
7813 | return i + 1; | |
7814 | } | |
7815 | return n; | |
7816 | } | |
fbd94c7a | 7817 | |
1e89106d AS |
7818 | struct bpf_cand_cache { |
7819 | const char *name; | |
7820 | u32 name_len; | |
7821 | u16 kind; | |
7822 | u16 cnt; | |
7823 | struct { | |
7824 | const struct btf *btf; | |
7825 | u32 id; | |
7826 | } cands[]; | |
7827 | }; | |
7828 | ||
7829 | static void bpf_free_cands(struct bpf_cand_cache *cands) | |
7830 | { | |
7831 | if (!cands->cnt) | |
7832 | /* empty candidate array was allocated on stack */ | |
7833 | return; | |
7834 | kfree(cands); | |
7835 | } | |
7836 | ||
7837 | static void bpf_free_cands_from_cache(struct bpf_cand_cache *cands) | |
7838 | { | |
7839 | kfree(cands->name); | |
7840 | kfree(cands); | |
7841 | } | |
7842 | ||
7843 | #define VMLINUX_CAND_CACHE_SIZE 31 | |
7844 | static struct bpf_cand_cache *vmlinux_cand_cache[VMLINUX_CAND_CACHE_SIZE]; | |
7845 | ||
7846 | #define MODULE_CAND_CACHE_SIZE 31 | |
7847 | static struct bpf_cand_cache *module_cand_cache[MODULE_CAND_CACHE_SIZE]; | |
7848 | ||
7849 | static DEFINE_MUTEX(cand_cache_mutex); | |
7850 | ||
7851 | static void __print_cand_cache(struct bpf_verifier_log *log, | |
7852 | struct bpf_cand_cache **cache, | |
7853 | int cache_size) | |
7854 | { | |
7855 | struct bpf_cand_cache *cc; | |
7856 | int i, j; | |
7857 | ||
7858 | for (i = 0; i < cache_size; i++) { | |
7859 | cc = cache[i]; | |
7860 | if (!cc) | |
7861 | continue; | |
7862 | bpf_log(log, "[%d]%s(", i, cc->name); | |
7863 | for (j = 0; j < cc->cnt; j++) { | |
7864 | bpf_log(log, "%d", cc->cands[j].id); | |
7865 | if (j < cc->cnt - 1) | |
7866 | bpf_log(log, " "); | |
7867 | } | |
7868 | bpf_log(log, "), "); | |
7869 | } | |
7870 | } | |
7871 | ||
7872 | static void print_cand_cache(struct bpf_verifier_log *log) | |
7873 | { | |
7874 | mutex_lock(&cand_cache_mutex); | |
7875 | bpf_log(log, "vmlinux_cand_cache:"); | |
7876 | __print_cand_cache(log, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); | |
7877 | bpf_log(log, "\nmodule_cand_cache:"); | |
7878 | __print_cand_cache(log, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
7879 | bpf_log(log, "\n"); | |
7880 | mutex_unlock(&cand_cache_mutex); | |
7881 | } | |
7882 | ||
7883 | static u32 hash_cands(struct bpf_cand_cache *cands) | |
7884 | { | |
7885 | return jhash(cands->name, cands->name_len, 0); | |
7886 | } | |
7887 | ||
7888 | static struct bpf_cand_cache *check_cand_cache(struct bpf_cand_cache *cands, | |
7889 | struct bpf_cand_cache **cache, | |
7890 | int cache_size) | |
7891 | { | |
7892 | struct bpf_cand_cache *cc = cache[hash_cands(cands) % cache_size]; | |
7893 | ||
7894 | if (cc && cc->name_len == cands->name_len && | |
7895 | !strncmp(cc->name, cands->name, cands->name_len)) | |
7896 | return cc; | |
7897 | return NULL; | |
7898 | } | |
7899 | ||
7900 | static size_t sizeof_cands(int cnt) | |
7901 | { | |
7902 | return offsetof(struct bpf_cand_cache, cands[cnt]); | |
7903 | } | |
7904 | ||
7905 | static struct bpf_cand_cache *populate_cand_cache(struct bpf_cand_cache *cands, | |
7906 | struct bpf_cand_cache **cache, | |
7907 | int cache_size) | |
7908 | { | |
7909 | struct bpf_cand_cache **cc = &cache[hash_cands(cands) % cache_size], *new_cands; | |
7910 | ||
7911 | if (*cc) { | |
7912 | bpf_free_cands_from_cache(*cc); | |
7913 | *cc = NULL; | |
7914 | } | |
4674f210 | 7915 | new_cands = kmemdup(cands, sizeof_cands(cands->cnt), GFP_KERNEL); |
1e89106d AS |
7916 | if (!new_cands) { |
7917 | bpf_free_cands(cands); | |
7918 | return ERR_PTR(-ENOMEM); | |
7919 | } | |
1e89106d AS |
7920 | /* strdup the name, since it will stay in cache. |
7921 | * the cands->name points to strings in prog's BTF and the prog can be unloaded. | |
7922 | */ | |
7923 | new_cands->name = kmemdup_nul(cands->name, cands->name_len, GFP_KERNEL); | |
7924 | bpf_free_cands(cands); | |
7925 | if (!new_cands->name) { | |
7926 | kfree(new_cands); | |
7927 | return ERR_PTR(-ENOMEM); | |
7928 | } | |
7929 | *cc = new_cands; | |
7930 | return new_cands; | |
7931 | } | |
7932 | ||
29f2e5bd | 7933 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
1e89106d AS |
7934 | static void __purge_cand_cache(struct btf *btf, struct bpf_cand_cache **cache, |
7935 | int cache_size) | |
7936 | { | |
7937 | struct bpf_cand_cache *cc; | |
7938 | int i, j; | |
7939 | ||
7940 | for (i = 0; i < cache_size; i++) { | |
7941 | cc = cache[i]; | |
7942 | if (!cc) | |
7943 | continue; | |
7944 | if (!btf) { | |
7945 | /* when new module is loaded purge all of module_cand_cache, | |
7946 | * since new module might have candidates with the name | |
7947 | * that matches cached cands. | |
7948 | */ | |
7949 | bpf_free_cands_from_cache(cc); | |
7950 | cache[i] = NULL; | |
7951 | continue; | |
7952 | } | |
7953 | /* when module is unloaded purge cache entries | |
7954 | * that match module's btf | |
7955 | */ | |
7956 | for (j = 0; j < cc->cnt; j++) | |
7957 | if (cc->cands[j].btf == btf) { | |
7958 | bpf_free_cands_from_cache(cc); | |
7959 | cache[i] = NULL; | |
7960 | break; | |
7961 | } | |
7962 | } | |
7963 | ||
7964 | } | |
7965 | ||
7966 | static void purge_cand_cache(struct btf *btf) | |
7967 | { | |
7968 | mutex_lock(&cand_cache_mutex); | |
7969 | __purge_cand_cache(btf, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
7970 | mutex_unlock(&cand_cache_mutex); | |
7971 | } | |
29f2e5bd | 7972 | #endif |
1e89106d AS |
7973 | |
7974 | static struct bpf_cand_cache * | |
7975 | bpf_core_add_cands(struct bpf_cand_cache *cands, const struct btf *targ_btf, | |
7976 | int targ_start_id) | |
7977 | { | |
7978 | struct bpf_cand_cache *new_cands; | |
7979 | const struct btf_type *t; | |
7980 | const char *targ_name; | |
7981 | size_t targ_essent_len; | |
7982 | int n, i; | |
7983 | ||
7984 | n = btf_nr_types(targ_btf); | |
7985 | for (i = targ_start_id; i < n; i++) { | |
7986 | t = btf_type_by_id(targ_btf, i); | |
7987 | if (btf_kind(t) != cands->kind) | |
7988 | continue; | |
7989 | ||
7990 | targ_name = btf_name_by_offset(targ_btf, t->name_off); | |
7991 | if (!targ_name) | |
7992 | continue; | |
7993 | ||
7994 | /* the resched point is before strncmp to make sure that search | |
7995 | * for non-existing name will have a chance to schedule(). | |
7996 | */ | |
7997 | cond_resched(); | |
7998 | ||
7999 | if (strncmp(cands->name, targ_name, cands->name_len) != 0) | |
8000 | continue; | |
8001 | ||
8002 | targ_essent_len = bpf_core_essential_name_len(targ_name); | |
8003 | if (targ_essent_len != cands->name_len) | |
8004 | continue; | |
8005 | ||
8006 | /* most of the time there is only one candidate for a given kind+name pair */ | |
8007 | new_cands = kmalloc(sizeof_cands(cands->cnt + 1), GFP_KERNEL); | |
8008 | if (!new_cands) { | |
8009 | bpf_free_cands(cands); | |
8010 | return ERR_PTR(-ENOMEM); | |
8011 | } | |
8012 | ||
8013 | memcpy(new_cands, cands, sizeof_cands(cands->cnt)); | |
8014 | bpf_free_cands(cands); | |
8015 | cands = new_cands; | |
8016 | cands->cands[cands->cnt].btf = targ_btf; | |
8017 | cands->cands[cands->cnt].id = i; | |
8018 | cands->cnt++; | |
8019 | } | |
8020 | return cands; | |
8021 | } | |
8022 | ||
8023 | static struct bpf_cand_cache * | |
8024 | bpf_core_find_cands(struct bpf_core_ctx *ctx, u32 local_type_id) | |
8025 | { | |
8026 | struct bpf_cand_cache *cands, *cc, local_cand = {}; | |
8027 | const struct btf *local_btf = ctx->btf; | |
8028 | const struct btf_type *local_type; | |
8029 | const struct btf *main_btf; | |
8030 | size_t local_essent_len; | |
8031 | struct btf *mod_btf; | |
8032 | const char *name; | |
8033 | int id; | |
8034 | ||
8035 | main_btf = bpf_get_btf_vmlinux(); | |
8036 | if (IS_ERR(main_btf)) | |
f18a4997 | 8037 | return ERR_CAST(main_btf); |
7ada3787 KKD |
8038 | if (!main_btf) |
8039 | return ERR_PTR(-EINVAL); | |
1e89106d AS |
8040 | |
8041 | local_type = btf_type_by_id(local_btf, local_type_id); | |
8042 | if (!local_type) | |
8043 | return ERR_PTR(-EINVAL); | |
8044 | ||
8045 | name = btf_name_by_offset(local_btf, local_type->name_off); | |
8046 | if (str_is_empty(name)) | |
8047 | return ERR_PTR(-EINVAL); | |
8048 | local_essent_len = bpf_core_essential_name_len(name); | |
8049 | ||
8050 | cands = &local_cand; | |
8051 | cands->name = name; | |
8052 | cands->kind = btf_kind(local_type); | |
8053 | cands->name_len = local_essent_len; | |
8054 | ||
8055 | cc = check_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); | |
8056 | /* cands is a pointer to stack here */ | |
8057 | if (cc) { | |
8058 | if (cc->cnt) | |
8059 | return cc; | |
8060 | goto check_modules; | |
8061 | } | |
8062 | ||
8063 | /* Attempt to find target candidates in vmlinux BTF first */ | |
8064 | cands = bpf_core_add_cands(cands, main_btf, 1); | |
8065 | if (IS_ERR(cands)) | |
f18a4997 | 8066 | return ERR_CAST(cands); |
1e89106d AS |
8067 | |
8068 | /* cands is a pointer to kmalloced memory here if cands->cnt > 0 */ | |
8069 | ||
8070 | /* populate cache even when cands->cnt == 0 */ | |
8071 | cc = populate_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); | |
8072 | if (IS_ERR(cc)) | |
f18a4997 | 8073 | return ERR_CAST(cc); |
1e89106d AS |
8074 | |
8075 | /* if vmlinux BTF has any candidate, don't go for module BTFs */ | |
8076 | if (cc->cnt) | |
8077 | return cc; | |
8078 | ||
8079 | check_modules: | |
8080 | /* cands is a pointer to stack here and cands->cnt == 0 */ | |
8081 | cc = check_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
8082 | if (cc) | |
8083 | /* if cache has it return it even if cc->cnt == 0 */ | |
8084 | return cc; | |
8085 | ||
8086 | /* If candidate is not found in vmlinux's BTF then search in module's BTFs */ | |
8087 | spin_lock_bh(&btf_idr_lock); | |
8088 | idr_for_each_entry(&btf_idr, mod_btf, id) { | |
8089 | if (!btf_is_module(mod_btf)) | |
8090 | continue; | |
8091 | /* linear search could be slow hence unlock/lock | |
8092 | * the IDR to avoiding holding it for too long | |
8093 | */ | |
8094 | btf_get(mod_btf); | |
8095 | spin_unlock_bh(&btf_idr_lock); | |
8096 | cands = bpf_core_add_cands(cands, mod_btf, btf_nr_types(main_btf)); | |
8097 | if (IS_ERR(cands)) { | |
8098 | btf_put(mod_btf); | |
f18a4997 | 8099 | return ERR_CAST(cands); |
1e89106d AS |
8100 | } |
8101 | spin_lock_bh(&btf_idr_lock); | |
8102 | btf_put(mod_btf); | |
8103 | } | |
8104 | spin_unlock_bh(&btf_idr_lock); | |
8105 | /* cands is a pointer to kmalloced memory here if cands->cnt > 0 | |
8106 | * or pointer to stack if cands->cnd == 0. | |
8107 | * Copy it into the cache even when cands->cnt == 0 and | |
8108 | * return the result. | |
8109 | */ | |
8110 | return populate_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
8111 | } | |
8112 | ||
fbd94c7a AS |
8113 | int bpf_core_apply(struct bpf_core_ctx *ctx, const struct bpf_core_relo *relo, |
8114 | int relo_idx, void *insn) | |
8115 | { | |
1e89106d AS |
8116 | bool need_cands = relo->kind != BPF_CORE_TYPE_ID_LOCAL; |
8117 | struct bpf_core_cand_list cands = {}; | |
adb8fa19 | 8118 | struct bpf_core_relo_res targ_res; |
78c1f8d0 | 8119 | struct bpf_core_spec *specs; |
1e89106d AS |
8120 | int err; |
8121 | ||
78c1f8d0 AS |
8122 | /* ~4k of temp memory necessary to convert LLVM spec like "0:1:0:5" |
8123 | * into arrays of btf_ids of struct fields and array indices. | |
8124 | */ | |
8125 | specs = kcalloc(3, sizeof(*specs), GFP_KERNEL); | |
8126 | if (!specs) | |
8127 | return -ENOMEM; | |
8128 | ||
1e89106d AS |
8129 | if (need_cands) { |
8130 | struct bpf_cand_cache *cc; | |
8131 | int i; | |
8132 | ||
8133 | mutex_lock(&cand_cache_mutex); | |
8134 | cc = bpf_core_find_cands(ctx, relo->type_id); | |
8135 | if (IS_ERR(cc)) { | |
8136 | bpf_log(ctx->log, "target candidate search failed for %d\n", | |
8137 | relo->type_id); | |
8138 | err = PTR_ERR(cc); | |
8139 | goto out; | |
8140 | } | |
8141 | if (cc->cnt) { | |
8142 | cands.cands = kcalloc(cc->cnt, sizeof(*cands.cands), GFP_KERNEL); | |
8143 | if (!cands.cands) { | |
8144 | err = -ENOMEM; | |
8145 | goto out; | |
8146 | } | |
8147 | } | |
8148 | for (i = 0; i < cc->cnt; i++) { | |
8149 | bpf_log(ctx->log, | |
8150 | "CO-RE relocating %s %s: found target candidate [%d]\n", | |
8151 | btf_kind_str[cc->kind], cc->name, cc->cands[i].id); | |
8152 | cands.cands[i].btf = cc->cands[i].btf; | |
8153 | cands.cands[i].id = cc->cands[i].id; | |
8154 | } | |
8155 | cands.len = cc->cnt; | |
8156 | /* cand_cache_mutex needs to span the cache lookup and | |
8157 | * copy of btf pointer into bpf_core_cand_list, | |
adb8fa19 | 8158 | * since module can be unloaded while bpf_core_calc_relo_insn |
1e89106d AS |
8159 | * is working with module's btf. |
8160 | */ | |
8161 | } | |
8162 | ||
adb8fa19 MV |
8163 | err = bpf_core_calc_relo_insn((void *)ctx->log, relo, relo_idx, ctx->btf, &cands, specs, |
8164 | &targ_res); | |
8165 | if (err) | |
8166 | goto out; | |
8167 | ||
8168 | err = bpf_core_patch_insn((void *)ctx->log, insn, relo->insn_off / 8, relo, relo_idx, | |
8169 | &targ_res); | |
8170 | ||
1e89106d | 8171 | out: |
78c1f8d0 | 8172 | kfree(specs); |
1e89106d AS |
8173 | if (need_cands) { |
8174 | kfree(cands.cands); | |
8175 | mutex_unlock(&cand_cache_mutex); | |
8176 | if (ctx->log->level & BPF_LOG_LEVEL2) | |
8177 | print_cand_cache(ctx->log); | |
8178 | } | |
8179 | return err; | |
fbd94c7a | 8180 | } |