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c561d110 | 1 | // SPDX-License-Identifier: GPL-2.0 |
69b693f0 MKL |
2 | /* Copyright (c) 2018 Facebook */ |
3 | ||
4 | #include <uapi/linux/btf.h> | |
91cc1a99 AS |
5 | #include <uapi/linux/bpf.h> |
6 | #include <uapi/linux/bpf_perf_event.h> | |
69b693f0 | 7 | #include <uapi/linux/types.h> |
b00b8dae | 8 | #include <linux/seq_file.h> |
69b693f0 | 9 | #include <linux/compiler.h> |
2667a262 | 10 | #include <linux/ctype.h> |
69b693f0 MKL |
11 | #include <linux/errno.h> |
12 | #include <linux/slab.h> | |
f56a653c MKL |
13 | #include <linux/anon_inodes.h> |
14 | #include <linux/file.h> | |
69b693f0 MKL |
15 | #include <linux/uaccess.h> |
16 | #include <linux/kernel.h> | |
78958fca | 17 | #include <linux/idr.h> |
f80442a4 | 18 | #include <linux/sort.h> |
69b693f0 MKL |
19 | #include <linux/bpf_verifier.h> |
20 | #include <linux/btf.h> | |
49f4e672 | 21 | #include <linux/btf_ids.h> |
91cc1a99 AS |
22 | #include <linux/skmsg.h> |
23 | #include <linux/perf_event.h> | |
eae2e83e | 24 | #include <linux/bsearch.h> |
36e68442 AN |
25 | #include <linux/kobject.h> |
26 | #include <linux/sysfs.h> | |
91cc1a99 | 27 | #include <net/sock.h> |
1e89106d | 28 | #include "../tools/lib/bpf/relo_core.h" |
69b693f0 MKL |
29 | |
30 | /* BTF (BPF Type Format) is the meta data format which describes | |
31 | * the data types of BPF program/map. Hence, it basically focus | |
32 | * on the C programming language which the modern BPF is primary | |
33 | * using. | |
34 | * | |
35 | * ELF Section: | |
36 | * ~~~~~~~~~~~ | |
37 | * The BTF data is stored under the ".BTF" ELF section | |
38 | * | |
39 | * struct btf_type: | |
40 | * ~~~~~~~~~~~~~~~ | |
41 | * Each 'struct btf_type' object describes a C data type. | |
42 | * Depending on the type it is describing, a 'struct btf_type' | |
43 | * object may be followed by more data. F.e. | |
44 | * To describe an array, 'struct btf_type' is followed by | |
45 | * 'struct btf_array'. | |
46 | * | |
47 | * 'struct btf_type' and any extra data following it are | |
48 | * 4 bytes aligned. | |
49 | * | |
50 | * Type section: | |
51 | * ~~~~~~~~~~~~~ | |
52 | * The BTF type section contains a list of 'struct btf_type' objects. | |
53 | * Each one describes a C type. Recall from the above section | |
54 | * that a 'struct btf_type' object could be immediately followed by extra | |
8fb33b60 | 55 | * data in order to describe some particular C types. |
69b693f0 MKL |
56 | * |
57 | * type_id: | |
58 | * ~~~~~~~ | |
59 | * Each btf_type object is identified by a type_id. The type_id | |
60 | * is implicitly implied by the location of the btf_type object in | |
61 | * the BTF type section. The first one has type_id 1. The second | |
62 | * one has type_id 2...etc. Hence, an earlier btf_type has | |
63 | * a smaller type_id. | |
64 | * | |
65 | * A btf_type object may refer to another btf_type object by using | |
66 | * type_id (i.e. the "type" in the "struct btf_type"). | |
67 | * | |
68 | * NOTE that we cannot assume any reference-order. | |
69 | * A btf_type object can refer to an earlier btf_type object | |
70 | * but it can also refer to a later btf_type object. | |
71 | * | |
72 | * For example, to describe "const void *". A btf_type | |
73 | * object describing "const" may refer to another btf_type | |
74 | * object describing "void *". This type-reference is done | |
75 | * by specifying type_id: | |
76 | * | |
77 | * [1] CONST (anon) type_id=2 | |
78 | * [2] PTR (anon) type_id=0 | |
79 | * | |
80 | * The above is the btf_verifier debug log: | |
81 | * - Each line started with "[?]" is a btf_type object | |
82 | * - [?] is the type_id of the btf_type object. | |
83 | * - CONST/PTR is the BTF_KIND_XXX | |
84 | * - "(anon)" is the name of the type. It just | |
85 | * happens that CONST and PTR has no name. | |
86 | * - type_id=XXX is the 'u32 type' in btf_type | |
87 | * | |
88 | * NOTE: "void" has type_id 0 | |
89 | * | |
90 | * String section: | |
91 | * ~~~~~~~~~~~~~~ | |
92 | * The BTF string section contains the names used by the type section. | |
93 | * Each string is referred by an "offset" from the beginning of the | |
94 | * string section. | |
95 | * | |
96 | * Each string is '\0' terminated. | |
97 | * | |
98 | * The first character in the string section must be '\0' | |
99 | * which is used to mean 'anonymous'. Some btf_type may not | |
100 | * have a name. | |
101 | */ | |
102 | ||
103 | /* BTF verification: | |
104 | * | |
105 | * To verify BTF data, two passes are needed. | |
106 | * | |
107 | * Pass #1 | |
108 | * ~~~~~~~ | |
109 | * The first pass is to collect all btf_type objects to | |
110 | * an array: "btf->types". | |
111 | * | |
112 | * Depending on the C type that a btf_type is describing, | |
113 | * a btf_type may be followed by extra data. We don't know | |
114 | * how many btf_type is there, and more importantly we don't | |
115 | * know where each btf_type is located in the type section. | |
116 | * | |
117 | * Without knowing the location of each type_id, most verifications | |
118 | * cannot be done. e.g. an earlier btf_type may refer to a later | |
119 | * btf_type (recall the "const void *" above), so we cannot | |
120 | * check this type-reference in the first pass. | |
121 | * | |
122 | * In the first pass, it still does some verifications (e.g. | |
123 | * checking the name is a valid offset to the string section). | |
eb3f595d MKL |
124 | * |
125 | * Pass #2 | |
126 | * ~~~~~~~ | |
127 | * The main focus is to resolve a btf_type that is referring | |
128 | * to another type. | |
129 | * | |
130 | * We have to ensure the referring type: | |
131 | * 1) does exist in the BTF (i.e. in btf->types[]) | |
132 | * 2) does not cause a loop: | |
133 | * struct A { | |
134 | * struct B b; | |
135 | * }; | |
136 | * | |
137 | * struct B { | |
138 | * struct A a; | |
139 | * }; | |
140 | * | |
141 | * btf_type_needs_resolve() decides if a btf_type needs | |
142 | * to be resolved. | |
143 | * | |
144 | * The needs_resolve type implements the "resolve()" ops which | |
145 | * essentially does a DFS and detects backedge. | |
146 | * | |
147 | * During resolve (or DFS), different C types have different | |
148 | * "RESOLVED" conditions. | |
149 | * | |
150 | * When resolving a BTF_KIND_STRUCT, we need to resolve all its | |
151 | * members because a member is always referring to another | |
152 | * type. A struct's member can be treated as "RESOLVED" if | |
153 | * it is referring to a BTF_KIND_PTR. Otherwise, the | |
154 | * following valid C struct would be rejected: | |
155 | * | |
156 | * struct A { | |
157 | * int m; | |
158 | * struct A *a; | |
159 | * }; | |
160 | * | |
161 | * When resolving a BTF_KIND_PTR, it needs to keep resolving if | |
162 | * it is referring to another BTF_KIND_PTR. Otherwise, we cannot | |
163 | * detect a pointer loop, e.g.: | |
164 | * BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR + | |
165 | * ^ | | |
166 | * +-----------------------------------------+ | |
167 | * | |
69b693f0 MKL |
168 | */ |
169 | ||
b1e8818c | 170 | #define BITS_PER_U128 (sizeof(u64) * BITS_PER_BYTE * 2) |
69b693f0 MKL |
171 | #define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1) |
172 | #define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK) | |
173 | #define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3) | |
174 | #define BITS_ROUNDUP_BYTES(bits) \ | |
175 | (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits)) | |
176 | ||
b1828f0b | 177 | #define BTF_INFO_MASK 0x9f00ffff |
aea2f7b8 MKL |
178 | #define BTF_INT_MASK 0x0fffffff |
179 | #define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE) | |
180 | #define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET) | |
181 | ||
69b693f0 MKL |
182 | /* 16MB for 64k structs and each has 16 members and |
183 | * a few MB spaces for the string section. | |
184 | * The hard limit is S32_MAX. | |
185 | */ | |
186 | #define BTF_MAX_SIZE (16 * 1024 * 1024) | |
69b693f0 | 187 | |
eb3f595d MKL |
188 | #define for_each_member_from(i, from, struct_type, member) \ |
189 | for (i = from, member = btf_type_member(struct_type) + from; \ | |
190 | i < btf_type_vlen(struct_type); \ | |
191 | i++, member++) | |
192 | ||
1dc92851 DB |
193 | #define for_each_vsi_from(i, from, struct_type, member) \ |
194 | for (i = from, member = btf_type_var_secinfo(struct_type) + from; \ | |
195 | i < btf_type_vlen(struct_type); \ | |
196 | i++, member++) | |
197 | ||
1b9ed84e QM |
198 | DEFINE_IDR(btf_idr); |
199 | DEFINE_SPINLOCK(btf_idr_lock); | |
78958fca | 200 | |
dee872e1 KKD |
201 | enum btf_kfunc_hook { |
202 | BTF_KFUNC_HOOK_XDP, | |
203 | BTF_KFUNC_HOOK_TC, | |
204 | BTF_KFUNC_HOOK_STRUCT_OPS, | |
205 | BTF_KFUNC_HOOK_MAX, | |
206 | }; | |
207 | ||
208 | enum { | |
209 | BTF_KFUNC_SET_MAX_CNT = 32, | |
210 | }; | |
211 | ||
212 | struct btf_kfunc_set_tab { | |
213 | struct btf_id_set *sets[BTF_KFUNC_HOOK_MAX][BTF_KFUNC_TYPE_MAX]; | |
214 | }; | |
215 | ||
69b693f0 | 216 | struct btf { |
f80442a4 | 217 | void *data; |
69b693f0 | 218 | struct btf_type **types; |
eb3f595d MKL |
219 | u32 *resolved_ids; |
220 | u32 *resolved_sizes; | |
69b693f0 MKL |
221 | const char *strings; |
222 | void *nohdr_data; | |
f80442a4 | 223 | struct btf_header hdr; |
951bb646 | 224 | u32 nr_types; /* includes VOID for base BTF */ |
69b693f0 MKL |
225 | u32 types_size; |
226 | u32 data_size; | |
f56a653c | 227 | refcount_t refcnt; |
78958fca MKL |
228 | u32 id; |
229 | struct rcu_head rcu; | |
dee872e1 | 230 | struct btf_kfunc_set_tab *kfunc_set_tab; |
951bb646 AN |
231 | |
232 | /* split BTF support */ | |
233 | struct btf *base_btf; | |
234 | u32 start_id; /* first type ID in this BTF (0 for base BTF) */ | |
235 | u32 start_str_off; /* first string offset (0 for base BTF) */ | |
53297220 AN |
236 | char name[MODULE_NAME_LEN]; |
237 | bool kernel_btf; | |
69b693f0 MKL |
238 | }; |
239 | ||
eb3f595d MKL |
240 | enum verifier_phase { |
241 | CHECK_META, | |
242 | CHECK_TYPE, | |
243 | }; | |
244 | ||
245 | struct resolve_vertex { | |
246 | const struct btf_type *t; | |
247 | u32 type_id; | |
248 | u16 next_member; | |
249 | }; | |
250 | ||
251 | enum visit_state { | |
252 | NOT_VISITED, | |
253 | VISITED, | |
254 | RESOLVED, | |
255 | }; | |
256 | ||
257 | enum resolve_mode { | |
258 | RESOLVE_TBD, /* To Be Determined */ | |
259 | RESOLVE_PTR, /* Resolving for Pointer */ | |
260 | RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union | |
261 | * or array | |
262 | */ | |
263 | }; | |
264 | ||
265 | #define MAX_RESOLVE_DEPTH 32 | |
266 | ||
f80442a4 MKL |
267 | struct btf_sec_info { |
268 | u32 off; | |
269 | u32 len; | |
270 | }; | |
271 | ||
69b693f0 MKL |
272 | struct btf_verifier_env { |
273 | struct btf *btf; | |
eb3f595d MKL |
274 | u8 *visit_states; |
275 | struct resolve_vertex stack[MAX_RESOLVE_DEPTH]; | |
69b693f0 MKL |
276 | struct bpf_verifier_log log; |
277 | u32 log_type_id; | |
eb3f595d MKL |
278 | u32 top_stack; |
279 | enum verifier_phase phase; | |
280 | enum resolve_mode resolve_mode; | |
69b693f0 MKL |
281 | }; |
282 | ||
283 | static const char * const btf_kind_str[NR_BTF_KINDS] = { | |
284 | [BTF_KIND_UNKN] = "UNKNOWN", | |
285 | [BTF_KIND_INT] = "INT", | |
286 | [BTF_KIND_PTR] = "PTR", | |
287 | [BTF_KIND_ARRAY] = "ARRAY", | |
288 | [BTF_KIND_STRUCT] = "STRUCT", | |
289 | [BTF_KIND_UNION] = "UNION", | |
290 | [BTF_KIND_ENUM] = "ENUM", | |
291 | [BTF_KIND_FWD] = "FWD", | |
292 | [BTF_KIND_TYPEDEF] = "TYPEDEF", | |
293 | [BTF_KIND_VOLATILE] = "VOLATILE", | |
294 | [BTF_KIND_CONST] = "CONST", | |
295 | [BTF_KIND_RESTRICT] = "RESTRICT", | |
2667a262 MKL |
296 | [BTF_KIND_FUNC] = "FUNC", |
297 | [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO", | |
1dc92851 DB |
298 | [BTF_KIND_VAR] = "VAR", |
299 | [BTF_KIND_DATASEC] = "DATASEC", | |
b1828f0b | 300 | [BTF_KIND_FLOAT] = "FLOAT", |
223f903e | 301 | [BTF_KIND_DECL_TAG] = "DECL_TAG", |
8c42d2fa | 302 | [BTF_KIND_TYPE_TAG] = "TYPE_TAG", |
69b693f0 MKL |
303 | }; |
304 | ||
e6ac2450 | 305 | const char *btf_type_str(const struct btf_type *t) |
be8704ff AS |
306 | { |
307 | return btf_kind_str[BTF_INFO_KIND(t->info)]; | |
308 | } | |
309 | ||
31d0bc81 AM |
310 | /* Chunk size we use in safe copy of data to be shown. */ |
311 | #define BTF_SHOW_OBJ_SAFE_SIZE 32 | |
312 | ||
313 | /* | |
314 | * This is the maximum size of a base type value (equivalent to a | |
315 | * 128-bit int); if we are at the end of our safe buffer and have | |
316 | * less than 16 bytes space we can't be assured of being able | |
317 | * to copy the next type safely, so in such cases we will initiate | |
318 | * a new copy. | |
319 | */ | |
320 | #define BTF_SHOW_OBJ_BASE_TYPE_SIZE 16 | |
321 | ||
322 | /* Type name size */ | |
323 | #define BTF_SHOW_NAME_SIZE 80 | |
324 | ||
325 | /* | |
326 | * Common data to all BTF show operations. Private show functions can add | |
327 | * their own data to a structure containing a struct btf_show and consult it | |
328 | * in the show callback. See btf_type_show() below. | |
329 | * | |
330 | * One challenge with showing nested data is we want to skip 0-valued | |
331 | * data, but in order to figure out whether a nested object is all zeros | |
332 | * we need to walk through it. As a result, we need to make two passes | |
333 | * when handling structs, unions and arrays; the first path simply looks | |
334 | * for nonzero data, while the second actually does the display. The first | |
335 | * pass is signalled by show->state.depth_check being set, and if we | |
336 | * encounter a non-zero value we set show->state.depth_to_show to | |
337 | * the depth at which we encountered it. When we have completed the | |
338 | * first pass, we will know if anything needs to be displayed if | |
339 | * depth_to_show > depth. See btf_[struct,array]_show() for the | |
340 | * implementation of this. | |
341 | * | |
342 | * Another problem is we want to ensure the data for display is safe to | |
343 | * access. To support this, the anonymous "struct {} obj" tracks the data | |
344 | * object and our safe copy of it. We copy portions of the data needed | |
345 | * to the object "copy" buffer, but because its size is limited to | |
346 | * BTF_SHOW_OBJ_COPY_LEN bytes, multiple copies may be required as we | |
347 | * traverse larger objects for display. | |
348 | * | |
349 | * The various data type show functions all start with a call to | |
350 | * btf_show_start_type() which returns a pointer to the safe copy | |
351 | * of the data needed (or if BTF_SHOW_UNSAFE is specified, to the | |
352 | * raw data itself). btf_show_obj_safe() is responsible for | |
353 | * using copy_from_kernel_nofault() to update the safe data if necessary | |
354 | * as we traverse the object's data. skbuff-like semantics are | |
355 | * used: | |
356 | * | |
357 | * - obj.head points to the start of the toplevel object for display | |
358 | * - obj.size is the size of the toplevel object | |
359 | * - obj.data points to the current point in the original data at | |
360 | * which our safe data starts. obj.data will advance as we copy | |
361 | * portions of the data. | |
362 | * | |
363 | * In most cases a single copy will suffice, but larger data structures | |
364 | * such as "struct task_struct" will require many copies. The logic in | |
365 | * btf_show_obj_safe() handles the logic that determines if a new | |
366 | * copy_from_kernel_nofault() is needed. | |
367 | */ | |
368 | struct btf_show { | |
369 | u64 flags; | |
370 | void *target; /* target of show operation (seq file, buffer) */ | |
371 | void (*showfn)(struct btf_show *show, const char *fmt, va_list args); | |
372 | const struct btf *btf; | |
373 | /* below are used during iteration */ | |
374 | struct { | |
375 | u8 depth; | |
376 | u8 depth_to_show; | |
377 | u8 depth_check; | |
378 | u8 array_member:1, | |
379 | array_terminated:1; | |
380 | u16 array_encoding; | |
381 | u32 type_id; | |
382 | int status; /* non-zero for error */ | |
383 | const struct btf_type *type; | |
384 | const struct btf_member *member; | |
385 | char name[BTF_SHOW_NAME_SIZE]; /* space for member name/type */ | |
386 | } state; | |
387 | struct { | |
388 | u32 size; | |
389 | void *head; | |
390 | void *data; | |
391 | u8 safe[BTF_SHOW_OBJ_SAFE_SIZE]; | |
392 | } obj; | |
393 | }; | |
394 | ||
69b693f0 MKL |
395 | struct btf_kind_operations { |
396 | s32 (*check_meta)(struct btf_verifier_env *env, | |
397 | const struct btf_type *t, | |
398 | u32 meta_left); | |
eb3f595d MKL |
399 | int (*resolve)(struct btf_verifier_env *env, |
400 | const struct resolve_vertex *v); | |
179cde8c MKL |
401 | int (*check_member)(struct btf_verifier_env *env, |
402 | const struct btf_type *struct_type, | |
403 | const struct btf_member *member, | |
404 | const struct btf_type *member_type); | |
9d5f9f70 YS |
405 | int (*check_kflag_member)(struct btf_verifier_env *env, |
406 | const struct btf_type *struct_type, | |
407 | const struct btf_member *member, | |
408 | const struct btf_type *member_type); | |
69b693f0 MKL |
409 | void (*log_details)(struct btf_verifier_env *env, |
410 | const struct btf_type *t); | |
31d0bc81 | 411 | void (*show)(const struct btf *btf, const struct btf_type *t, |
b00b8dae | 412 | u32 type_id, void *data, u8 bits_offsets, |
31d0bc81 | 413 | struct btf_show *show); |
69b693f0 MKL |
414 | }; |
415 | ||
416 | static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS]; | |
417 | static struct btf_type btf_void; | |
418 | ||
2667a262 MKL |
419 | static int btf_resolve(struct btf_verifier_env *env, |
420 | const struct btf_type *t, u32 type_id); | |
421 | ||
d7e7b42f YS |
422 | static int btf_func_check(struct btf_verifier_env *env, |
423 | const struct btf_type *t); | |
424 | ||
eb3f595d MKL |
425 | static bool btf_type_is_modifier(const struct btf_type *t) |
426 | { | |
427 | /* Some of them is not strictly a C modifier | |
428 | * but they are grouped into the same bucket | |
429 | * for BTF concern: | |
430 | * A type (t) that refers to another | |
431 | * type through t->type AND its size cannot | |
432 | * be determined without following the t->type. | |
433 | * | |
434 | * ptr does not fall into this bucket | |
435 | * because its size is always sizeof(void *). | |
436 | */ | |
437 | switch (BTF_INFO_KIND(t->info)) { | |
438 | case BTF_KIND_TYPEDEF: | |
439 | case BTF_KIND_VOLATILE: | |
440 | case BTF_KIND_CONST: | |
441 | case BTF_KIND_RESTRICT: | |
8c42d2fa | 442 | case BTF_KIND_TYPE_TAG: |
eb3f595d MKL |
443 | return true; |
444 | } | |
445 | ||
446 | return false; | |
447 | } | |
448 | ||
2824ecb7 | 449 | bool btf_type_is_void(const struct btf_type *t) |
eb3f595d | 450 | { |
b47a0bd2 MKL |
451 | return t == &btf_void; |
452 | } | |
453 | ||
454 | static bool btf_type_is_fwd(const struct btf_type *t) | |
455 | { | |
456 | return BTF_INFO_KIND(t->info) == BTF_KIND_FWD; | |
457 | } | |
458 | ||
459 | static bool btf_type_nosize(const struct btf_type *t) | |
460 | { | |
2667a262 MKL |
461 | return btf_type_is_void(t) || btf_type_is_fwd(t) || |
462 | btf_type_is_func(t) || btf_type_is_func_proto(t); | |
eb3f595d MKL |
463 | } |
464 | ||
b47a0bd2 | 465 | static bool btf_type_nosize_or_null(const struct btf_type *t) |
eb3f595d | 466 | { |
b47a0bd2 | 467 | return !t || btf_type_nosize(t); |
eb3f595d MKL |
468 | } |
469 | ||
d83525ca AS |
470 | static bool __btf_type_is_struct(const struct btf_type *t) |
471 | { | |
472 | return BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT; | |
473 | } | |
474 | ||
eb3f595d MKL |
475 | static bool btf_type_is_array(const struct btf_type *t) |
476 | { | |
477 | return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY; | |
478 | } | |
479 | ||
1dc92851 DB |
480 | static bool btf_type_is_datasec(const struct btf_type *t) |
481 | { | |
482 | return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC; | |
483 | } | |
484 | ||
223f903e | 485 | static bool btf_type_is_decl_tag(const struct btf_type *t) |
b5ea834d | 486 | { |
223f903e | 487 | return BTF_INFO_KIND(t->info) == BTF_KIND_DECL_TAG; |
b5ea834d YS |
488 | } |
489 | ||
223f903e | 490 | static bool btf_type_is_decl_tag_target(const struct btf_type *t) |
b5ea834d YS |
491 | { |
492 | return btf_type_is_func(t) || btf_type_is_struct(t) || | |
bd16dee6 | 493 | btf_type_is_var(t) || btf_type_is_typedef(t); |
b5ea834d YS |
494 | } |
495 | ||
541c3bad | 496 | u32 btf_nr_types(const struct btf *btf) |
951bb646 AN |
497 | { |
498 | u32 total = 0; | |
499 | ||
500 | while (btf) { | |
501 | total += btf->nr_types; | |
502 | btf = btf->base_btf; | |
503 | } | |
504 | ||
505 | return total; | |
506 | } | |
507 | ||
27ae7997 MKL |
508 | s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind) |
509 | { | |
510 | const struct btf_type *t; | |
511 | const char *tname; | |
951bb646 | 512 | u32 i, total; |
27ae7997 | 513 | |
541c3bad | 514 | total = btf_nr_types(btf); |
951bb646 AN |
515 | for (i = 1; i < total; i++) { |
516 | t = btf_type_by_id(btf, i); | |
27ae7997 MKL |
517 | if (BTF_INFO_KIND(t->info) != kind) |
518 | continue; | |
519 | ||
520 | tname = btf_name_by_offset(btf, t->name_off); | |
521 | if (!strcmp(tname, name)) | |
522 | return i; | |
523 | } | |
524 | ||
525 | return -ENOENT; | |
526 | } | |
527 | ||
528 | const struct btf_type *btf_type_skip_modifiers(const struct btf *btf, | |
529 | u32 id, u32 *res_id) | |
530 | { | |
531 | const struct btf_type *t = btf_type_by_id(btf, id); | |
532 | ||
533 | while (btf_type_is_modifier(t)) { | |
534 | id = t->type; | |
535 | t = btf_type_by_id(btf, t->type); | |
536 | } | |
537 | ||
538 | if (res_id) | |
539 | *res_id = id; | |
540 | ||
541 | return t; | |
542 | } | |
543 | ||
544 | const struct btf_type *btf_type_resolve_ptr(const struct btf *btf, | |
545 | u32 id, u32 *res_id) | |
546 | { | |
547 | const struct btf_type *t; | |
548 | ||
549 | t = btf_type_skip_modifiers(btf, id, NULL); | |
550 | if (!btf_type_is_ptr(t)) | |
551 | return NULL; | |
552 | ||
553 | return btf_type_skip_modifiers(btf, t->type, res_id); | |
554 | } | |
555 | ||
556 | const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf, | |
557 | u32 id, u32 *res_id) | |
558 | { | |
559 | const struct btf_type *ptype; | |
560 | ||
561 | ptype = btf_type_resolve_ptr(btf, id, res_id); | |
562 | if (ptype && btf_type_is_func_proto(ptype)) | |
563 | return ptype; | |
564 | ||
565 | return NULL; | |
566 | } | |
567 | ||
1dc92851 DB |
568 | /* Types that act only as a source, not sink or intermediate |
569 | * type when resolving. | |
570 | */ | |
571 | static bool btf_type_is_resolve_source_only(const struct btf_type *t) | |
572 | { | |
573 | return btf_type_is_var(t) || | |
223f903e | 574 | btf_type_is_decl_tag(t) || |
1dc92851 DB |
575 | btf_type_is_datasec(t); |
576 | } | |
577 | ||
eb3f595d MKL |
578 | /* What types need to be resolved? |
579 | * | |
580 | * btf_type_is_modifier() is an obvious one. | |
581 | * | |
582 | * btf_type_is_struct() because its member refers to | |
583 | * another type (through member->type). | |
1dc92851 DB |
584 | * |
585 | * btf_type_is_var() because the variable refers to | |
586 | * another type. btf_type_is_datasec() holds multiple | |
587 | * btf_type_is_var() types that need resolving. | |
588 | * | |
eb3f595d MKL |
589 | * btf_type_is_array() because its element (array->type) |
590 | * refers to another type. Array can be thought of a | |
591 | * special case of struct while array just has the same | |
592 | * member-type repeated by array->nelems of times. | |
593 | */ | |
594 | static bool btf_type_needs_resolve(const struct btf_type *t) | |
595 | { | |
596 | return btf_type_is_modifier(t) || | |
1dc92851 DB |
597 | btf_type_is_ptr(t) || |
598 | btf_type_is_struct(t) || | |
599 | btf_type_is_array(t) || | |
600 | btf_type_is_var(t) || | |
d7e7b42f | 601 | btf_type_is_func(t) || |
223f903e | 602 | btf_type_is_decl_tag(t) || |
1dc92851 | 603 | btf_type_is_datasec(t); |
eb3f595d MKL |
604 | } |
605 | ||
606 | /* t->size can be used */ | |
607 | static bool btf_type_has_size(const struct btf_type *t) | |
608 | { | |
609 | switch (BTF_INFO_KIND(t->info)) { | |
610 | case BTF_KIND_INT: | |
611 | case BTF_KIND_STRUCT: | |
612 | case BTF_KIND_UNION: | |
613 | case BTF_KIND_ENUM: | |
1dc92851 | 614 | case BTF_KIND_DATASEC: |
b1828f0b | 615 | case BTF_KIND_FLOAT: |
eb3f595d MKL |
616 | return true; |
617 | } | |
618 | ||
619 | return false; | |
620 | } | |
621 | ||
69b693f0 MKL |
622 | static const char *btf_int_encoding_str(u8 encoding) |
623 | { | |
624 | if (encoding == 0) | |
625 | return "(none)"; | |
626 | else if (encoding == BTF_INT_SIGNED) | |
627 | return "SIGNED"; | |
628 | else if (encoding == BTF_INT_CHAR) | |
629 | return "CHAR"; | |
630 | else if (encoding == BTF_INT_BOOL) | |
631 | return "BOOL"; | |
69b693f0 MKL |
632 | else |
633 | return "UNKN"; | |
634 | } | |
635 | ||
69b693f0 MKL |
636 | static u32 btf_type_int(const struct btf_type *t) |
637 | { | |
638 | return *(u32 *)(t + 1); | |
639 | } | |
640 | ||
641 | static const struct btf_array *btf_type_array(const struct btf_type *t) | |
642 | { | |
643 | return (const struct btf_array *)(t + 1); | |
644 | } | |
645 | ||
69b693f0 MKL |
646 | static const struct btf_enum *btf_type_enum(const struct btf_type *t) |
647 | { | |
648 | return (const struct btf_enum *)(t + 1); | |
649 | } | |
650 | ||
1dc92851 DB |
651 | static const struct btf_var *btf_type_var(const struct btf_type *t) |
652 | { | |
653 | return (const struct btf_var *)(t + 1); | |
654 | } | |
655 | ||
223f903e | 656 | static const struct btf_decl_tag *btf_type_decl_tag(const struct btf_type *t) |
b5ea834d | 657 | { |
223f903e | 658 | return (const struct btf_decl_tag *)(t + 1); |
b5ea834d YS |
659 | } |
660 | ||
69b693f0 MKL |
661 | static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t) |
662 | { | |
663 | return kind_ops[BTF_INFO_KIND(t->info)]; | |
664 | } | |
665 | ||
583c5318 | 666 | static bool btf_name_offset_valid(const struct btf *btf, u32 offset) |
69b693f0 | 667 | { |
951bb646 AN |
668 | if (!BTF_STR_OFFSET_VALID(offset)) |
669 | return false; | |
670 | ||
671 | while (offset < btf->start_str_off) | |
672 | btf = btf->base_btf; | |
673 | ||
674 | offset -= btf->start_str_off; | |
675 | return offset < btf->hdr.str_len; | |
69b693f0 MKL |
676 | } |
677 | ||
1dc92851 DB |
678 | static bool __btf_name_char_ok(char c, bool first, bool dot_ok) |
679 | { | |
680 | if ((first ? !isalpha(c) : | |
681 | !isalnum(c)) && | |
682 | c != '_' && | |
683 | ((c == '.' && !dot_ok) || | |
684 | c != '.')) | |
685 | return false; | |
686 | return true; | |
687 | } | |
688 | ||
951bb646 AN |
689 | static const char *btf_str_by_offset(const struct btf *btf, u32 offset) |
690 | { | |
691 | while (offset < btf->start_str_off) | |
692 | btf = btf->base_btf; | |
693 | ||
694 | offset -= btf->start_str_off; | |
695 | if (offset < btf->hdr.str_len) | |
696 | return &btf->strings[offset]; | |
697 | ||
698 | return NULL; | |
699 | } | |
700 | ||
1dc92851 | 701 | static bool __btf_name_valid(const struct btf *btf, u32 offset, bool dot_ok) |
2667a262 MKL |
702 | { |
703 | /* offset must be valid */ | |
951bb646 | 704 | const char *src = btf_str_by_offset(btf, offset); |
2667a262 MKL |
705 | const char *src_limit; |
706 | ||
1dc92851 | 707 | if (!__btf_name_char_ok(*src, true, dot_ok)) |
2667a262 MKL |
708 | return false; |
709 | ||
710 | /* set a limit on identifier length */ | |
711 | src_limit = src + KSYM_NAME_LEN; | |
712 | src++; | |
713 | while (*src && src < src_limit) { | |
1dc92851 | 714 | if (!__btf_name_char_ok(*src, false, dot_ok)) |
2667a262 MKL |
715 | return false; |
716 | src++; | |
717 | } | |
718 | ||
719 | return !*src; | |
720 | } | |
721 | ||
1dc92851 DB |
722 | /* Only C-style identifier is permitted. This can be relaxed if |
723 | * necessary. | |
724 | */ | |
725 | static bool btf_name_valid_identifier(const struct btf *btf, u32 offset) | |
726 | { | |
727 | return __btf_name_valid(btf, offset, false); | |
728 | } | |
729 | ||
730 | static bool btf_name_valid_section(const struct btf *btf, u32 offset) | |
731 | { | |
732 | return __btf_name_valid(btf, offset, true); | |
733 | } | |
734 | ||
23127b33 | 735 | static const char *__btf_name_by_offset(const struct btf *btf, u32 offset) |
69b693f0 | 736 | { |
951bb646 AN |
737 | const char *name; |
738 | ||
aea2f7b8 | 739 | if (!offset) |
69b693f0 | 740 | return "(anon)"; |
951bb646 AN |
741 | |
742 | name = btf_str_by_offset(btf, offset); | |
743 | return name ?: "(invalid-name-offset)"; | |
69b693f0 MKL |
744 | } |
745 | ||
23127b33 MKL |
746 | const char *btf_name_by_offset(const struct btf *btf, u32 offset) |
747 | { | |
951bb646 | 748 | return btf_str_by_offset(btf, offset); |
23127b33 MKL |
749 | } |
750 | ||
838e9690 | 751 | const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id) |
eb3f595d | 752 | { |
951bb646 AN |
753 | while (type_id < btf->start_id) |
754 | btf = btf->base_btf; | |
eb3f595d | 755 | |
951bb646 AN |
756 | type_id -= btf->start_id; |
757 | if (type_id >= btf->nr_types) | |
758 | return NULL; | |
eb3f595d MKL |
759 | return btf->types[type_id]; |
760 | } | |
761 | ||
4ef5f574 MKL |
762 | /* |
763 | * Regular int is not a bit field and it must be either | |
b1e8818c | 764 | * u8/u16/u32/u64 or __int128. |
4ef5f574 MKL |
765 | */ |
766 | static bool btf_type_int_is_regular(const struct btf_type *t) | |
767 | { | |
36fc3c8c | 768 | u8 nr_bits, nr_bytes; |
4ef5f574 MKL |
769 | u32 int_data; |
770 | ||
771 | int_data = btf_type_int(t); | |
772 | nr_bits = BTF_INT_BITS(int_data); | |
773 | nr_bytes = BITS_ROUNDUP_BYTES(nr_bits); | |
774 | if (BITS_PER_BYTE_MASKED(nr_bits) || | |
775 | BTF_INT_OFFSET(int_data) || | |
776 | (nr_bytes != sizeof(u8) && nr_bytes != sizeof(u16) && | |
b1e8818c YS |
777 | nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64) && |
778 | nr_bytes != (2 * sizeof(u64)))) { | |
4ef5f574 MKL |
779 | return false; |
780 | } | |
781 | ||
782 | return true; | |
783 | } | |
784 | ||
9a1126b6 | 785 | /* |
ffa0c1cf YS |
786 | * Check that given struct member is a regular int with expected |
787 | * offset and size. | |
9a1126b6 | 788 | */ |
ffa0c1cf YS |
789 | bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s, |
790 | const struct btf_member *m, | |
791 | u32 expected_offset, u32 expected_size) | |
9a1126b6 | 792 | { |
ffa0c1cf YS |
793 | const struct btf_type *t; |
794 | u32 id, int_data; | |
795 | u8 nr_bits; | |
9a1126b6 | 796 | |
ffa0c1cf YS |
797 | id = m->type; |
798 | t = btf_type_id_size(btf, &id, NULL); | |
799 | if (!t || !btf_type_is_int(t)) | |
9a1126b6 RG |
800 | return false; |
801 | ||
802 | int_data = btf_type_int(t); | |
803 | nr_bits = BTF_INT_BITS(int_data); | |
ffa0c1cf YS |
804 | if (btf_type_kflag(s)) { |
805 | u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset); | |
806 | u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset); | |
807 | ||
808 | /* if kflag set, int should be a regular int and | |
809 | * bit offset should be at byte boundary. | |
810 | */ | |
811 | return !bitfield_size && | |
812 | BITS_ROUNDUP_BYTES(bit_offset) == expected_offset && | |
813 | BITS_ROUNDUP_BYTES(nr_bits) == expected_size; | |
814 | } | |
815 | ||
816 | if (BTF_INT_OFFSET(int_data) || | |
817 | BITS_PER_BYTE_MASKED(m->offset) || | |
818 | BITS_ROUNDUP_BYTES(m->offset) != expected_offset || | |
819 | BITS_PER_BYTE_MASKED(nr_bits) || | |
820 | BITS_ROUNDUP_BYTES(nr_bits) != expected_size) | |
9a1126b6 RG |
821 | return false; |
822 | ||
823 | return true; | |
824 | } | |
825 | ||
31d0bc81 AM |
826 | /* Similar to btf_type_skip_modifiers() but does not skip typedefs. */ |
827 | static const struct btf_type *btf_type_skip_qualifiers(const struct btf *btf, | |
828 | u32 id) | |
829 | { | |
830 | const struct btf_type *t = btf_type_by_id(btf, id); | |
831 | ||
832 | while (btf_type_is_modifier(t) && | |
833 | BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF) { | |
31d0bc81 AM |
834 | t = btf_type_by_id(btf, t->type); |
835 | } | |
836 | ||
837 | return t; | |
838 | } | |
839 | ||
840 | #define BTF_SHOW_MAX_ITER 10 | |
841 | ||
842 | #define BTF_KIND_BIT(kind) (1ULL << kind) | |
843 | ||
844 | /* | |
845 | * Populate show->state.name with type name information. | |
846 | * Format of type name is | |
847 | * | |
848 | * [.member_name = ] (type_name) | |
849 | */ | |
850 | static const char *btf_show_name(struct btf_show *show) | |
851 | { | |
852 | /* BTF_MAX_ITER array suffixes "[]" */ | |
853 | const char *array_suffixes = "[][][][][][][][][][]"; | |
854 | const char *array_suffix = &array_suffixes[strlen(array_suffixes)]; | |
855 | /* BTF_MAX_ITER pointer suffixes "*" */ | |
856 | const char *ptr_suffixes = "**********"; | |
857 | const char *ptr_suffix = &ptr_suffixes[strlen(ptr_suffixes)]; | |
858 | const char *name = NULL, *prefix = "", *parens = ""; | |
859 | const struct btf_member *m = show->state.member; | |
73b6eae5 | 860 | const struct btf_type *t; |
31d0bc81 AM |
861 | const struct btf_array *array; |
862 | u32 id = show->state.type_id; | |
863 | const char *member = NULL; | |
864 | bool show_member = false; | |
865 | u64 kinds = 0; | |
866 | int i; | |
867 | ||
868 | show->state.name[0] = '\0'; | |
869 | ||
870 | /* | |
871 | * Don't show type name if we're showing an array member; | |
872 | * in that case we show the array type so don't need to repeat | |
873 | * ourselves for each member. | |
874 | */ | |
875 | if (show->state.array_member) | |
876 | return ""; | |
877 | ||
878 | /* Retrieve member name, if any. */ | |
879 | if (m) { | |
880 | member = btf_name_by_offset(show->btf, m->name_off); | |
881 | show_member = strlen(member) > 0; | |
882 | id = m->type; | |
883 | } | |
884 | ||
885 | /* | |
886 | * Start with type_id, as we have resolved the struct btf_type * | |
887 | * via btf_modifier_show() past the parent typedef to the child | |
888 | * struct, int etc it is defined as. In such cases, the type_id | |
889 | * still represents the starting type while the struct btf_type * | |
890 | * in our show->state points at the resolved type of the typedef. | |
891 | */ | |
892 | t = btf_type_by_id(show->btf, id); | |
893 | if (!t) | |
894 | return ""; | |
895 | ||
896 | /* | |
897 | * The goal here is to build up the right number of pointer and | |
898 | * array suffixes while ensuring the type name for a typedef | |
899 | * is represented. Along the way we accumulate a list of | |
900 | * BTF kinds we have encountered, since these will inform later | |
901 | * display; for example, pointer types will not require an | |
902 | * opening "{" for struct, we will just display the pointer value. | |
903 | * | |
904 | * We also want to accumulate the right number of pointer or array | |
905 | * indices in the format string while iterating until we get to | |
906 | * the typedef/pointee/array member target type. | |
907 | * | |
908 | * We start by pointing at the end of pointer and array suffix | |
909 | * strings; as we accumulate pointers and arrays we move the pointer | |
910 | * or array string backwards so it will show the expected number of | |
911 | * '*' or '[]' for the type. BTF_SHOW_MAX_ITER of nesting of pointers | |
912 | * and/or arrays and typedefs are supported as a precaution. | |
913 | * | |
914 | * We also want to get typedef name while proceeding to resolve | |
915 | * type it points to so that we can add parentheses if it is a | |
916 | * "typedef struct" etc. | |
917 | */ | |
918 | for (i = 0; i < BTF_SHOW_MAX_ITER; i++) { | |
919 | ||
920 | switch (BTF_INFO_KIND(t->info)) { | |
921 | case BTF_KIND_TYPEDEF: | |
922 | if (!name) | |
923 | name = btf_name_by_offset(show->btf, | |
924 | t->name_off); | |
925 | kinds |= BTF_KIND_BIT(BTF_KIND_TYPEDEF); | |
926 | id = t->type; | |
927 | break; | |
928 | case BTF_KIND_ARRAY: | |
929 | kinds |= BTF_KIND_BIT(BTF_KIND_ARRAY); | |
930 | parens = "["; | |
931 | if (!t) | |
932 | return ""; | |
933 | array = btf_type_array(t); | |
934 | if (array_suffix > array_suffixes) | |
935 | array_suffix -= 2; | |
936 | id = array->type; | |
937 | break; | |
938 | case BTF_KIND_PTR: | |
939 | kinds |= BTF_KIND_BIT(BTF_KIND_PTR); | |
940 | if (ptr_suffix > ptr_suffixes) | |
941 | ptr_suffix -= 1; | |
942 | id = t->type; | |
943 | break; | |
944 | default: | |
945 | id = 0; | |
946 | break; | |
947 | } | |
948 | if (!id) | |
949 | break; | |
950 | t = btf_type_skip_qualifiers(show->btf, id); | |
951 | } | |
952 | /* We may not be able to represent this type; bail to be safe */ | |
953 | if (i == BTF_SHOW_MAX_ITER) | |
954 | return ""; | |
955 | ||
956 | if (!name) | |
957 | name = btf_name_by_offset(show->btf, t->name_off); | |
958 | ||
959 | switch (BTF_INFO_KIND(t->info)) { | |
960 | case BTF_KIND_STRUCT: | |
961 | case BTF_KIND_UNION: | |
962 | prefix = BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT ? | |
963 | "struct" : "union"; | |
964 | /* if it's an array of struct/union, parens is already set */ | |
965 | if (!(kinds & (BTF_KIND_BIT(BTF_KIND_ARRAY)))) | |
966 | parens = "{"; | |
967 | break; | |
968 | case BTF_KIND_ENUM: | |
969 | prefix = "enum"; | |
970 | break; | |
971 | default: | |
972 | break; | |
973 | } | |
974 | ||
975 | /* pointer does not require parens */ | |
976 | if (kinds & BTF_KIND_BIT(BTF_KIND_PTR)) | |
977 | parens = ""; | |
978 | /* typedef does not require struct/union/enum prefix */ | |
979 | if (kinds & BTF_KIND_BIT(BTF_KIND_TYPEDEF)) | |
980 | prefix = ""; | |
981 | ||
982 | if (!name) | |
983 | name = ""; | |
984 | ||
985 | /* Even if we don't want type name info, we want parentheses etc */ | |
986 | if (show->flags & BTF_SHOW_NONAME) | |
987 | snprintf(show->state.name, sizeof(show->state.name), "%s", | |
988 | parens); | |
989 | else | |
990 | snprintf(show->state.name, sizeof(show->state.name), | |
991 | "%s%s%s(%s%s%s%s%s%s)%s", | |
992 | /* first 3 strings comprise ".member = " */ | |
993 | show_member ? "." : "", | |
994 | show_member ? member : "", | |
995 | show_member ? " = " : "", | |
996 | /* ...next is our prefix (struct, enum, etc) */ | |
997 | prefix, | |
998 | strlen(prefix) > 0 && strlen(name) > 0 ? " " : "", | |
999 | /* ...this is the type name itself */ | |
1000 | name, | |
1001 | /* ...suffixed by the appropriate '*', '[]' suffixes */ | |
1002 | strlen(ptr_suffix) > 0 ? " " : "", ptr_suffix, | |
1003 | array_suffix, parens); | |
1004 | ||
1005 | return show->state.name; | |
1006 | } | |
1007 | ||
1008 | static const char *__btf_show_indent(struct btf_show *show) | |
1009 | { | |
1010 | const char *indents = " "; | |
1011 | const char *indent = &indents[strlen(indents)]; | |
1012 | ||
1013 | if ((indent - show->state.depth) >= indents) | |
1014 | return indent - show->state.depth; | |
1015 | return indents; | |
1016 | } | |
1017 | ||
1018 | static const char *btf_show_indent(struct btf_show *show) | |
1019 | { | |
1020 | return show->flags & BTF_SHOW_COMPACT ? "" : __btf_show_indent(show); | |
1021 | } | |
1022 | ||
1023 | static const char *btf_show_newline(struct btf_show *show) | |
1024 | { | |
1025 | return show->flags & BTF_SHOW_COMPACT ? "" : "\n"; | |
1026 | } | |
1027 | ||
1028 | static const char *btf_show_delim(struct btf_show *show) | |
1029 | { | |
1030 | if (show->state.depth == 0) | |
1031 | return ""; | |
1032 | ||
1033 | if ((show->flags & BTF_SHOW_COMPACT) && show->state.type && | |
1034 | BTF_INFO_KIND(show->state.type->info) == BTF_KIND_UNION) | |
1035 | return "|"; | |
1036 | ||
1037 | return ","; | |
1038 | } | |
1039 | ||
1040 | __printf(2, 3) static void btf_show(struct btf_show *show, const char *fmt, ...) | |
1041 | { | |
1042 | va_list args; | |
1043 | ||
1044 | if (!show->state.depth_check) { | |
1045 | va_start(args, fmt); | |
1046 | show->showfn(show, fmt, args); | |
1047 | va_end(args); | |
1048 | } | |
1049 | } | |
1050 | ||
1051 | /* Macros are used here as btf_show_type_value[s]() prepends and appends | |
1052 | * format specifiers to the format specifier passed in; these do the work of | |
1053 | * adding indentation, delimiters etc while the caller simply has to specify | |
1054 | * the type value(s) in the format specifier + value(s). | |
1055 | */ | |
1056 | #define btf_show_type_value(show, fmt, value) \ | |
1057 | do { \ | |
1058 | if ((value) != 0 || (show->flags & BTF_SHOW_ZERO) || \ | |
1059 | show->state.depth == 0) { \ | |
1060 | btf_show(show, "%s%s" fmt "%s%s", \ | |
1061 | btf_show_indent(show), \ | |
1062 | btf_show_name(show), \ | |
1063 | value, btf_show_delim(show), \ | |
1064 | btf_show_newline(show)); \ | |
1065 | if (show->state.depth > show->state.depth_to_show) \ | |
1066 | show->state.depth_to_show = show->state.depth; \ | |
1067 | } \ | |
1068 | } while (0) | |
1069 | ||
1070 | #define btf_show_type_values(show, fmt, ...) \ | |
1071 | do { \ | |
1072 | btf_show(show, "%s%s" fmt "%s%s", btf_show_indent(show), \ | |
1073 | btf_show_name(show), \ | |
1074 | __VA_ARGS__, btf_show_delim(show), \ | |
1075 | btf_show_newline(show)); \ | |
1076 | if (show->state.depth > show->state.depth_to_show) \ | |
1077 | show->state.depth_to_show = show->state.depth; \ | |
1078 | } while (0) | |
1079 | ||
1080 | /* How much is left to copy to safe buffer after @data? */ | |
1081 | static int btf_show_obj_size_left(struct btf_show *show, void *data) | |
1082 | { | |
1083 | return show->obj.head + show->obj.size - data; | |
1084 | } | |
1085 | ||
1086 | /* Is object pointed to by @data of @size already copied to our safe buffer? */ | |
1087 | static bool btf_show_obj_is_safe(struct btf_show *show, void *data, int size) | |
1088 | { | |
1089 | return data >= show->obj.data && | |
1090 | (data + size) < (show->obj.data + BTF_SHOW_OBJ_SAFE_SIZE); | |
1091 | } | |
1092 | ||
1093 | /* | |
1094 | * If object pointed to by @data of @size falls within our safe buffer, return | |
1095 | * the equivalent pointer to the same safe data. Assumes | |
1096 | * copy_from_kernel_nofault() has already happened and our safe buffer is | |
1097 | * populated. | |
1098 | */ | |
1099 | static void *__btf_show_obj_safe(struct btf_show *show, void *data, int size) | |
1100 | { | |
1101 | if (btf_show_obj_is_safe(show, data, size)) | |
1102 | return show->obj.safe + (data - show->obj.data); | |
1103 | return NULL; | |
1104 | } | |
1105 | ||
1106 | /* | |
1107 | * Return a safe-to-access version of data pointed to by @data. | |
1108 | * We do this by copying the relevant amount of information | |
1109 | * to the struct btf_show obj.safe buffer using copy_from_kernel_nofault(). | |
1110 | * | |
1111 | * If BTF_SHOW_UNSAFE is specified, just return data as-is; no | |
1112 | * safe copy is needed. | |
1113 | * | |
1114 | * Otherwise we need to determine if we have the required amount | |
1115 | * of data (determined by the @data pointer and the size of the | |
1116 | * largest base type we can encounter (represented by | |
1117 | * BTF_SHOW_OBJ_BASE_TYPE_SIZE). Having that much data ensures | |
1118 | * that we will be able to print some of the current object, | |
1119 | * and if more is needed a copy will be triggered. | |
1120 | * Some objects such as structs will not fit into the buffer; | |
1121 | * in such cases additional copies when we iterate over their | |
1122 | * members may be needed. | |
1123 | * | |
1124 | * btf_show_obj_safe() is used to return a safe buffer for | |
1125 | * btf_show_start_type(); this ensures that as we recurse into | |
1126 | * nested types we always have safe data for the given type. | |
1127 | * This approach is somewhat wasteful; it's possible for example | |
1128 | * that when iterating over a large union we'll end up copying the | |
1129 | * same data repeatedly, but the goal is safety not performance. | |
1130 | * We use stack data as opposed to per-CPU buffers because the | |
1131 | * iteration over a type can take some time, and preemption handling | |
1132 | * would greatly complicate use of the safe buffer. | |
1133 | */ | |
1134 | static void *btf_show_obj_safe(struct btf_show *show, | |
1135 | const struct btf_type *t, | |
1136 | void *data) | |
1137 | { | |
1138 | const struct btf_type *rt; | |
1139 | int size_left, size; | |
1140 | void *safe = NULL; | |
1141 | ||
1142 | if (show->flags & BTF_SHOW_UNSAFE) | |
1143 | return data; | |
1144 | ||
1145 | rt = btf_resolve_size(show->btf, t, &size); | |
1146 | if (IS_ERR(rt)) { | |
1147 | show->state.status = PTR_ERR(rt); | |
1148 | return NULL; | |
1149 | } | |
1150 | ||
1151 | /* | |
1152 | * Is this toplevel object? If so, set total object size and | |
1153 | * initialize pointers. Otherwise check if we still fall within | |
1154 | * our safe object data. | |
1155 | */ | |
1156 | if (show->state.depth == 0) { | |
1157 | show->obj.size = size; | |
1158 | show->obj.head = data; | |
1159 | } else { | |
1160 | /* | |
1161 | * If the size of the current object is > our remaining | |
1162 | * safe buffer we _may_ need to do a new copy. However | |
1163 | * consider the case of a nested struct; it's size pushes | |
1164 | * us over the safe buffer limit, but showing any individual | |
1165 | * struct members does not. In such cases, we don't need | |
1166 | * to initiate a fresh copy yet; however we definitely need | |
1167 | * at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes left | |
1168 | * in our buffer, regardless of the current object size. | |
1169 | * The logic here is that as we resolve types we will | |
1170 | * hit a base type at some point, and we need to be sure | |
1171 | * the next chunk of data is safely available to display | |
1172 | * that type info safely. We cannot rely on the size of | |
1173 | * the current object here because it may be much larger | |
1174 | * than our current buffer (e.g. task_struct is 8k). | |
1175 | * All we want to do here is ensure that we can print the | |
1176 | * next basic type, which we can if either | |
1177 | * - the current type size is within the safe buffer; or | |
1178 | * - at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes are left in | |
1179 | * the safe buffer. | |
1180 | */ | |
1181 | safe = __btf_show_obj_safe(show, data, | |
1182 | min(size, | |
1183 | BTF_SHOW_OBJ_BASE_TYPE_SIZE)); | |
1184 | } | |
1185 | ||
1186 | /* | |
1187 | * We need a new copy to our safe object, either because we haven't | |
8fb33b60 | 1188 | * yet copied and are initializing safe data, or because the data |
31d0bc81 AM |
1189 | * we want falls outside the boundaries of the safe object. |
1190 | */ | |
1191 | if (!safe) { | |
1192 | size_left = btf_show_obj_size_left(show, data); | |
1193 | if (size_left > BTF_SHOW_OBJ_SAFE_SIZE) | |
1194 | size_left = BTF_SHOW_OBJ_SAFE_SIZE; | |
1195 | show->state.status = copy_from_kernel_nofault(show->obj.safe, | |
1196 | data, size_left); | |
1197 | if (!show->state.status) { | |
1198 | show->obj.data = data; | |
1199 | safe = show->obj.safe; | |
1200 | } | |
1201 | } | |
1202 | ||
1203 | return safe; | |
1204 | } | |
1205 | ||
1206 | /* | |
1207 | * Set the type we are starting to show and return a safe data pointer | |
1208 | * to be used for showing the associated data. | |
1209 | */ | |
1210 | static void *btf_show_start_type(struct btf_show *show, | |
1211 | const struct btf_type *t, | |
1212 | u32 type_id, void *data) | |
1213 | { | |
1214 | show->state.type = t; | |
1215 | show->state.type_id = type_id; | |
1216 | show->state.name[0] = '\0'; | |
1217 | ||
1218 | return btf_show_obj_safe(show, t, data); | |
1219 | } | |
1220 | ||
1221 | static void btf_show_end_type(struct btf_show *show) | |
1222 | { | |
1223 | show->state.type = NULL; | |
1224 | show->state.type_id = 0; | |
1225 | show->state.name[0] = '\0'; | |
1226 | } | |
1227 | ||
1228 | static void *btf_show_start_aggr_type(struct btf_show *show, | |
1229 | const struct btf_type *t, | |
1230 | u32 type_id, void *data) | |
1231 | { | |
1232 | void *safe_data = btf_show_start_type(show, t, type_id, data); | |
1233 | ||
1234 | if (!safe_data) | |
1235 | return safe_data; | |
1236 | ||
1237 | btf_show(show, "%s%s%s", btf_show_indent(show), | |
1238 | btf_show_name(show), | |
1239 | btf_show_newline(show)); | |
1240 | show->state.depth++; | |
1241 | return safe_data; | |
1242 | } | |
1243 | ||
1244 | static void btf_show_end_aggr_type(struct btf_show *show, | |
1245 | const char *suffix) | |
1246 | { | |
1247 | show->state.depth--; | |
1248 | btf_show(show, "%s%s%s%s", btf_show_indent(show), suffix, | |
1249 | btf_show_delim(show), btf_show_newline(show)); | |
1250 | btf_show_end_type(show); | |
1251 | } | |
1252 | ||
1253 | static void btf_show_start_member(struct btf_show *show, | |
1254 | const struct btf_member *m) | |
1255 | { | |
1256 | show->state.member = m; | |
1257 | } | |
1258 | ||
1259 | static void btf_show_start_array_member(struct btf_show *show) | |
1260 | { | |
1261 | show->state.array_member = 1; | |
1262 | btf_show_start_member(show, NULL); | |
1263 | } | |
1264 | ||
1265 | static void btf_show_end_member(struct btf_show *show) | |
1266 | { | |
1267 | show->state.member = NULL; | |
1268 | } | |
1269 | ||
1270 | static void btf_show_end_array_member(struct btf_show *show) | |
1271 | { | |
1272 | show->state.array_member = 0; | |
1273 | btf_show_end_member(show); | |
1274 | } | |
1275 | ||
1276 | static void *btf_show_start_array_type(struct btf_show *show, | |
1277 | const struct btf_type *t, | |
1278 | u32 type_id, | |
1279 | u16 array_encoding, | |
1280 | void *data) | |
1281 | { | |
1282 | show->state.array_encoding = array_encoding; | |
1283 | show->state.array_terminated = 0; | |
1284 | return btf_show_start_aggr_type(show, t, type_id, data); | |
1285 | } | |
1286 | ||
1287 | static void btf_show_end_array_type(struct btf_show *show) | |
1288 | { | |
1289 | show->state.array_encoding = 0; | |
1290 | show->state.array_terminated = 0; | |
1291 | btf_show_end_aggr_type(show, "]"); | |
1292 | } | |
1293 | ||
1294 | static void *btf_show_start_struct_type(struct btf_show *show, | |
1295 | const struct btf_type *t, | |
1296 | u32 type_id, | |
1297 | void *data) | |
1298 | { | |
1299 | return btf_show_start_aggr_type(show, t, type_id, data); | |
1300 | } | |
1301 | ||
1302 | static void btf_show_end_struct_type(struct btf_show *show) | |
1303 | { | |
1304 | btf_show_end_aggr_type(show, "}"); | |
1305 | } | |
1306 | ||
69b693f0 MKL |
1307 | __printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log, |
1308 | const char *fmt, ...) | |
1309 | { | |
1310 | va_list args; | |
1311 | ||
1312 | va_start(args, fmt); | |
1313 | bpf_verifier_vlog(log, fmt, args); | |
1314 | va_end(args); | |
1315 | } | |
1316 | ||
1317 | __printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env, | |
1318 | const char *fmt, ...) | |
1319 | { | |
1320 | struct bpf_verifier_log *log = &env->log; | |
1321 | va_list args; | |
1322 | ||
1323 | if (!bpf_verifier_log_needed(log)) | |
1324 | return; | |
1325 | ||
1326 | va_start(args, fmt); | |
1327 | bpf_verifier_vlog(log, fmt, args); | |
1328 | va_end(args); | |
1329 | } | |
1330 | ||
1331 | __printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env, | |
1332 | const struct btf_type *t, | |
1333 | bool log_details, | |
1334 | const char *fmt, ...) | |
1335 | { | |
1336 | struct bpf_verifier_log *log = &env->log; | |
1337 | u8 kind = BTF_INFO_KIND(t->info); | |
1338 | struct btf *btf = env->btf; | |
1339 | va_list args; | |
1340 | ||
1341 | if (!bpf_verifier_log_needed(log)) | |
1342 | return; | |
1343 | ||
8580ac94 AS |
1344 | /* btf verifier prints all types it is processing via |
1345 | * btf_verifier_log_type(..., fmt = NULL). | |
1346 | * Skip those prints for in-kernel BTF verification. | |
1347 | */ | |
1348 | if (log->level == BPF_LOG_KERNEL && !fmt) | |
1349 | return; | |
1350 | ||
69b693f0 MKL |
1351 | __btf_verifier_log(log, "[%u] %s %s%s", |
1352 | env->log_type_id, | |
1353 | btf_kind_str[kind], | |
23127b33 | 1354 | __btf_name_by_offset(btf, t->name_off), |
69b693f0 MKL |
1355 | log_details ? " " : ""); |
1356 | ||
1357 | if (log_details) | |
1358 | btf_type_ops(t)->log_details(env, t); | |
1359 | ||
1360 | if (fmt && *fmt) { | |
1361 | __btf_verifier_log(log, " "); | |
1362 | va_start(args, fmt); | |
1363 | bpf_verifier_vlog(log, fmt, args); | |
1364 | va_end(args); | |
1365 | } | |
1366 | ||
1367 | __btf_verifier_log(log, "\n"); | |
1368 | } | |
1369 | ||
1370 | #define btf_verifier_log_type(env, t, ...) \ | |
1371 | __btf_verifier_log_type((env), (t), true, __VA_ARGS__) | |
1372 | #define btf_verifier_log_basic(env, t, ...) \ | |
1373 | __btf_verifier_log_type((env), (t), false, __VA_ARGS__) | |
1374 | ||
1375 | __printf(4, 5) | |
1376 | static void btf_verifier_log_member(struct btf_verifier_env *env, | |
1377 | const struct btf_type *struct_type, | |
1378 | const struct btf_member *member, | |
1379 | const char *fmt, ...) | |
1380 | { | |
1381 | struct bpf_verifier_log *log = &env->log; | |
1382 | struct btf *btf = env->btf; | |
1383 | va_list args; | |
1384 | ||
1385 | if (!bpf_verifier_log_needed(log)) | |
1386 | return; | |
1387 | ||
8580ac94 AS |
1388 | if (log->level == BPF_LOG_KERNEL && !fmt) |
1389 | return; | |
eb3f595d MKL |
1390 | /* The CHECK_META phase already did a btf dump. |
1391 | * | |
1392 | * If member is logged again, it must hit an error in | |
1393 | * parsing this member. It is useful to print out which | |
1394 | * struct this member belongs to. | |
1395 | */ | |
1396 | if (env->phase != CHECK_META) | |
1397 | btf_verifier_log_type(env, struct_type, NULL); | |
1398 | ||
9d5f9f70 YS |
1399 | if (btf_type_kflag(struct_type)) |
1400 | __btf_verifier_log(log, | |
1401 | "\t%s type_id=%u bitfield_size=%u bits_offset=%u", | |
1402 | __btf_name_by_offset(btf, member->name_off), | |
1403 | member->type, | |
1404 | BTF_MEMBER_BITFIELD_SIZE(member->offset), | |
1405 | BTF_MEMBER_BIT_OFFSET(member->offset)); | |
1406 | else | |
1407 | __btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u", | |
1408 | __btf_name_by_offset(btf, member->name_off), | |
1409 | member->type, member->offset); | |
69b693f0 MKL |
1410 | |
1411 | if (fmt && *fmt) { | |
1412 | __btf_verifier_log(log, " "); | |
1413 | va_start(args, fmt); | |
1414 | bpf_verifier_vlog(log, fmt, args); | |
1415 | va_end(args); | |
1416 | } | |
1417 | ||
1418 | __btf_verifier_log(log, "\n"); | |
1419 | } | |
1420 | ||
1dc92851 DB |
1421 | __printf(4, 5) |
1422 | static void btf_verifier_log_vsi(struct btf_verifier_env *env, | |
1423 | const struct btf_type *datasec_type, | |
1424 | const struct btf_var_secinfo *vsi, | |
1425 | const char *fmt, ...) | |
1426 | { | |
1427 | struct bpf_verifier_log *log = &env->log; | |
1428 | va_list args; | |
1429 | ||
1430 | if (!bpf_verifier_log_needed(log)) | |
1431 | return; | |
8580ac94 AS |
1432 | if (log->level == BPF_LOG_KERNEL && !fmt) |
1433 | return; | |
1dc92851 DB |
1434 | if (env->phase != CHECK_META) |
1435 | btf_verifier_log_type(env, datasec_type, NULL); | |
1436 | ||
1437 | __btf_verifier_log(log, "\t type_id=%u offset=%u size=%u", | |
1438 | vsi->type, vsi->offset, vsi->size); | |
1439 | if (fmt && *fmt) { | |
1440 | __btf_verifier_log(log, " "); | |
1441 | va_start(args, fmt); | |
1442 | bpf_verifier_vlog(log, fmt, args); | |
1443 | va_end(args); | |
1444 | } | |
1445 | ||
1446 | __btf_verifier_log(log, "\n"); | |
1447 | } | |
1448 | ||
f80442a4 MKL |
1449 | static void btf_verifier_log_hdr(struct btf_verifier_env *env, |
1450 | u32 btf_data_size) | |
69b693f0 MKL |
1451 | { |
1452 | struct bpf_verifier_log *log = &env->log; | |
1453 | const struct btf *btf = env->btf; | |
1454 | const struct btf_header *hdr; | |
1455 | ||
1456 | if (!bpf_verifier_log_needed(log)) | |
1457 | return; | |
1458 | ||
8580ac94 AS |
1459 | if (log->level == BPF_LOG_KERNEL) |
1460 | return; | |
f80442a4 | 1461 | hdr = &btf->hdr; |
69b693f0 MKL |
1462 | __btf_verifier_log(log, "magic: 0x%x\n", hdr->magic); |
1463 | __btf_verifier_log(log, "version: %u\n", hdr->version); | |
1464 | __btf_verifier_log(log, "flags: 0x%x\n", hdr->flags); | |
f80442a4 | 1465 | __btf_verifier_log(log, "hdr_len: %u\n", hdr->hdr_len); |
69b693f0 | 1466 | __btf_verifier_log(log, "type_off: %u\n", hdr->type_off); |
f80442a4 | 1467 | __btf_verifier_log(log, "type_len: %u\n", hdr->type_len); |
69b693f0 MKL |
1468 | __btf_verifier_log(log, "str_off: %u\n", hdr->str_off); |
1469 | __btf_verifier_log(log, "str_len: %u\n", hdr->str_len); | |
f80442a4 | 1470 | __btf_verifier_log(log, "btf_total_size: %u\n", btf_data_size); |
69b693f0 MKL |
1471 | } |
1472 | ||
1473 | static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t) | |
1474 | { | |
1475 | struct btf *btf = env->btf; | |
1476 | ||
951bb646 | 1477 | if (btf->types_size == btf->nr_types) { |
69b693f0 MKL |
1478 | /* Expand 'types' array */ |
1479 | ||
1480 | struct btf_type **new_types; | |
1481 | u32 expand_by, new_size; | |
1482 | ||
951bb646 | 1483 | if (btf->start_id + btf->types_size == BTF_MAX_TYPE) { |
69b693f0 MKL |
1484 | btf_verifier_log(env, "Exceeded max num of types"); |
1485 | return -E2BIG; | |
1486 | } | |
1487 | ||
1488 | expand_by = max_t(u32, btf->types_size >> 2, 16); | |
aea2f7b8 | 1489 | new_size = min_t(u32, BTF_MAX_TYPE, |
69b693f0 MKL |
1490 | btf->types_size + expand_by); |
1491 | ||
778e1cdd | 1492 | new_types = kvcalloc(new_size, sizeof(*new_types), |
69b693f0 MKL |
1493 | GFP_KERNEL | __GFP_NOWARN); |
1494 | if (!new_types) | |
1495 | return -ENOMEM; | |
1496 | ||
951bb646 AN |
1497 | if (btf->nr_types == 0) { |
1498 | if (!btf->base_btf) { | |
1499 | /* lazily init VOID type */ | |
1500 | new_types[0] = &btf_void; | |
1501 | btf->nr_types++; | |
1502 | } | |
1503 | } else { | |
69b693f0 | 1504 | memcpy(new_types, btf->types, |
951bb646 AN |
1505 | sizeof(*btf->types) * btf->nr_types); |
1506 | } | |
69b693f0 MKL |
1507 | |
1508 | kvfree(btf->types); | |
1509 | btf->types = new_types; | |
1510 | btf->types_size = new_size; | |
1511 | } | |
1512 | ||
951bb646 | 1513 | btf->types[btf->nr_types++] = t; |
69b693f0 MKL |
1514 | |
1515 | return 0; | |
1516 | } | |
1517 | ||
78958fca MKL |
1518 | static int btf_alloc_id(struct btf *btf) |
1519 | { | |
1520 | int id; | |
1521 | ||
1522 | idr_preload(GFP_KERNEL); | |
1523 | spin_lock_bh(&btf_idr_lock); | |
1524 | id = idr_alloc_cyclic(&btf_idr, btf, 1, INT_MAX, GFP_ATOMIC); | |
1525 | if (id > 0) | |
1526 | btf->id = id; | |
1527 | spin_unlock_bh(&btf_idr_lock); | |
1528 | idr_preload_end(); | |
1529 | ||
1530 | if (WARN_ON_ONCE(!id)) | |
1531 | return -ENOSPC; | |
1532 | ||
1533 | return id > 0 ? 0 : id; | |
1534 | } | |
1535 | ||
1536 | static void btf_free_id(struct btf *btf) | |
1537 | { | |
1538 | unsigned long flags; | |
1539 | ||
1540 | /* | |
1541 | * In map-in-map, calling map_delete_elem() on outer | |
1542 | * map will call bpf_map_put on the inner map. | |
1543 | * It will then eventually call btf_free_id() | |
1544 | * on the inner map. Some of the map_delete_elem() | |
1545 | * implementation may have irq disabled, so | |
1546 | * we need to use the _irqsave() version instead | |
1547 | * of the _bh() version. | |
1548 | */ | |
1549 | spin_lock_irqsave(&btf_idr_lock, flags); | |
1550 | idr_remove(&btf_idr, btf->id); | |
1551 | spin_unlock_irqrestore(&btf_idr_lock, flags); | |
1552 | } | |
1553 | ||
dee872e1 KKD |
1554 | static void btf_free_kfunc_set_tab(struct btf *btf) |
1555 | { | |
1556 | struct btf_kfunc_set_tab *tab = btf->kfunc_set_tab; | |
1557 | int hook, type; | |
1558 | ||
1559 | if (!tab) | |
1560 | return; | |
1561 | /* For module BTF, we directly assign the sets being registered, so | |
1562 | * there is nothing to free except kfunc_set_tab. | |
1563 | */ | |
1564 | if (btf_is_module(btf)) | |
1565 | goto free_tab; | |
1566 | for (hook = 0; hook < ARRAY_SIZE(tab->sets); hook++) { | |
1567 | for (type = 0; type < ARRAY_SIZE(tab->sets[0]); type++) | |
1568 | kfree(tab->sets[hook][type]); | |
1569 | } | |
1570 | free_tab: | |
1571 | kfree(tab); | |
1572 | btf->kfunc_set_tab = NULL; | |
1573 | } | |
1574 | ||
69b693f0 MKL |
1575 | static void btf_free(struct btf *btf) |
1576 | { | |
dee872e1 | 1577 | btf_free_kfunc_set_tab(btf); |
69b693f0 | 1578 | kvfree(btf->types); |
eb3f595d MKL |
1579 | kvfree(btf->resolved_sizes); |
1580 | kvfree(btf->resolved_ids); | |
69b693f0 MKL |
1581 | kvfree(btf->data); |
1582 | kfree(btf); | |
1583 | } | |
1584 | ||
78958fca | 1585 | static void btf_free_rcu(struct rcu_head *rcu) |
f56a653c | 1586 | { |
78958fca MKL |
1587 | struct btf *btf = container_of(rcu, struct btf, rcu); |
1588 | ||
1589 | btf_free(btf); | |
f56a653c MKL |
1590 | } |
1591 | ||
22dc4a0f AN |
1592 | void btf_get(struct btf *btf) |
1593 | { | |
1594 | refcount_inc(&btf->refcnt); | |
1595 | } | |
1596 | ||
f56a653c MKL |
1597 | void btf_put(struct btf *btf) |
1598 | { | |
78958fca MKL |
1599 | if (btf && refcount_dec_and_test(&btf->refcnt)) { |
1600 | btf_free_id(btf); | |
1601 | call_rcu(&btf->rcu, btf_free_rcu); | |
1602 | } | |
f56a653c MKL |
1603 | } |
1604 | ||
eb3f595d MKL |
1605 | static int env_resolve_init(struct btf_verifier_env *env) |
1606 | { | |
1607 | struct btf *btf = env->btf; | |
1608 | u32 nr_types = btf->nr_types; | |
1609 | u32 *resolved_sizes = NULL; | |
1610 | u32 *resolved_ids = NULL; | |
1611 | u8 *visit_states = NULL; | |
1612 | ||
951bb646 | 1613 | resolved_sizes = kvcalloc(nr_types, sizeof(*resolved_sizes), |
eb3f595d MKL |
1614 | GFP_KERNEL | __GFP_NOWARN); |
1615 | if (!resolved_sizes) | |
1616 | goto nomem; | |
1617 | ||
951bb646 | 1618 | resolved_ids = kvcalloc(nr_types, sizeof(*resolved_ids), |
eb3f595d MKL |
1619 | GFP_KERNEL | __GFP_NOWARN); |
1620 | if (!resolved_ids) | |
1621 | goto nomem; | |
1622 | ||
951bb646 | 1623 | visit_states = kvcalloc(nr_types, sizeof(*visit_states), |
eb3f595d MKL |
1624 | GFP_KERNEL | __GFP_NOWARN); |
1625 | if (!visit_states) | |
1626 | goto nomem; | |
1627 | ||
1628 | btf->resolved_sizes = resolved_sizes; | |
1629 | btf->resolved_ids = resolved_ids; | |
1630 | env->visit_states = visit_states; | |
1631 | ||
1632 | return 0; | |
1633 | ||
1634 | nomem: | |
1635 | kvfree(resolved_sizes); | |
1636 | kvfree(resolved_ids); | |
1637 | kvfree(visit_states); | |
1638 | return -ENOMEM; | |
1639 | } | |
1640 | ||
69b693f0 MKL |
1641 | static void btf_verifier_env_free(struct btf_verifier_env *env) |
1642 | { | |
eb3f595d | 1643 | kvfree(env->visit_states); |
69b693f0 MKL |
1644 | kfree(env); |
1645 | } | |
1646 | ||
eb3f595d MKL |
1647 | static bool env_type_is_resolve_sink(const struct btf_verifier_env *env, |
1648 | const struct btf_type *next_type) | |
1649 | { | |
1650 | switch (env->resolve_mode) { | |
1651 | case RESOLVE_TBD: | |
1652 | /* int, enum or void is a sink */ | |
1653 | return !btf_type_needs_resolve(next_type); | |
1654 | case RESOLVE_PTR: | |
2667a262 MKL |
1655 | /* int, enum, void, struct, array, func or func_proto is a sink |
1656 | * for ptr | |
1657 | */ | |
eb3f595d MKL |
1658 | return !btf_type_is_modifier(next_type) && |
1659 | !btf_type_is_ptr(next_type); | |
1660 | case RESOLVE_STRUCT_OR_ARRAY: | |
2667a262 MKL |
1661 | /* int, enum, void, ptr, func or func_proto is a sink |
1662 | * for struct and array | |
1663 | */ | |
eb3f595d MKL |
1664 | return !btf_type_is_modifier(next_type) && |
1665 | !btf_type_is_array(next_type) && | |
1666 | !btf_type_is_struct(next_type); | |
1667 | default: | |
53c8036c | 1668 | BUG(); |
eb3f595d MKL |
1669 | } |
1670 | } | |
1671 | ||
1672 | static bool env_type_is_resolved(const struct btf_verifier_env *env, | |
1673 | u32 type_id) | |
1674 | { | |
951bb646 AN |
1675 | /* base BTF types should be resolved by now */ |
1676 | if (type_id < env->btf->start_id) | |
1677 | return true; | |
1678 | ||
1679 | return env->visit_states[type_id - env->btf->start_id] == RESOLVED; | |
eb3f595d MKL |
1680 | } |
1681 | ||
1682 | static int env_stack_push(struct btf_verifier_env *env, | |
1683 | const struct btf_type *t, u32 type_id) | |
1684 | { | |
951bb646 | 1685 | const struct btf *btf = env->btf; |
eb3f595d MKL |
1686 | struct resolve_vertex *v; |
1687 | ||
1688 | if (env->top_stack == MAX_RESOLVE_DEPTH) | |
1689 | return -E2BIG; | |
1690 | ||
951bb646 AN |
1691 | if (type_id < btf->start_id |
1692 | || env->visit_states[type_id - btf->start_id] != NOT_VISITED) | |
eb3f595d MKL |
1693 | return -EEXIST; |
1694 | ||
951bb646 | 1695 | env->visit_states[type_id - btf->start_id] = VISITED; |
eb3f595d MKL |
1696 | |
1697 | v = &env->stack[env->top_stack++]; | |
1698 | v->t = t; | |
1699 | v->type_id = type_id; | |
1700 | v->next_member = 0; | |
1701 | ||
1702 | if (env->resolve_mode == RESOLVE_TBD) { | |
1703 | if (btf_type_is_ptr(t)) | |
1704 | env->resolve_mode = RESOLVE_PTR; | |
1705 | else if (btf_type_is_struct(t) || btf_type_is_array(t)) | |
1706 | env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY; | |
1707 | } | |
1708 | ||
1709 | return 0; | |
1710 | } | |
1711 | ||
1712 | static void env_stack_set_next_member(struct btf_verifier_env *env, | |
1713 | u16 next_member) | |
1714 | { | |
1715 | env->stack[env->top_stack - 1].next_member = next_member; | |
1716 | } | |
1717 | ||
1718 | static void env_stack_pop_resolved(struct btf_verifier_env *env, | |
1719 | u32 resolved_type_id, | |
1720 | u32 resolved_size) | |
1721 | { | |
1722 | u32 type_id = env->stack[--(env->top_stack)].type_id; | |
1723 | struct btf *btf = env->btf; | |
1724 | ||
951bb646 | 1725 | type_id -= btf->start_id; /* adjust to local type id */ |
eb3f595d MKL |
1726 | btf->resolved_sizes[type_id] = resolved_size; |
1727 | btf->resolved_ids[type_id] = resolved_type_id; | |
1728 | env->visit_states[type_id] = RESOLVED; | |
1729 | } | |
1730 | ||
1731 | static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env) | |
1732 | { | |
1733 | return env->top_stack ? &env->stack[env->top_stack - 1] : NULL; | |
1734 | } | |
1735 | ||
7e3617a7 MKL |
1736 | /* Resolve the size of a passed-in "type" |
1737 | * | |
1738 | * type: is an array (e.g. u32 array[x][y]) | |
1739 | * return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY, | |
1740 | * *type_size: (x * y * sizeof(u32)). Hence, *type_size always | |
1741 | * corresponds to the return type. | |
1742 | * *elem_type: u32 | |
69ff3047 | 1743 | * *elem_id: id of u32 |
7e3617a7 MKL |
1744 | * *total_nelems: (x * y). Hence, individual elem size is |
1745 | * (*type_size / *total_nelems) | |
887c31a3 | 1746 | * *type_id: id of type if it's changed within the function, 0 if not |
7e3617a7 MKL |
1747 | * |
1748 | * type: is not an array (e.g. const struct X) | |
1749 | * return type: type "struct X" | |
1750 | * *type_size: sizeof(struct X) | |
1751 | * *elem_type: same as return type ("struct X") | |
69ff3047 | 1752 | * *elem_id: 0 |
7e3617a7 | 1753 | * *total_nelems: 1 |
887c31a3 | 1754 | * *type_id: id of type if it's changed within the function, 0 if not |
7e3617a7 | 1755 | */ |
6298399b JO |
1756 | static const struct btf_type * |
1757 | __btf_resolve_size(const struct btf *btf, const struct btf_type *type, | |
1758 | u32 *type_size, const struct btf_type **elem_type, | |
887c31a3 | 1759 | u32 *elem_id, u32 *total_nelems, u32 *type_id) |
7e3617a7 MKL |
1760 | { |
1761 | const struct btf_type *array_type = NULL; | |
69ff3047 | 1762 | const struct btf_array *array = NULL; |
887c31a3 | 1763 | u32 i, size, nelems = 1, id = 0; |
7e3617a7 MKL |
1764 | |
1765 | for (i = 0; i < MAX_RESOLVE_DEPTH; i++) { | |
1766 | switch (BTF_INFO_KIND(type->info)) { | |
1767 | /* type->size can be used */ | |
1768 | case BTF_KIND_INT: | |
1769 | case BTF_KIND_STRUCT: | |
1770 | case BTF_KIND_UNION: | |
1771 | case BTF_KIND_ENUM: | |
b1828f0b | 1772 | case BTF_KIND_FLOAT: |
7e3617a7 MKL |
1773 | size = type->size; |
1774 | goto resolved; | |
1775 | ||
1776 | case BTF_KIND_PTR: | |
1777 | size = sizeof(void *); | |
1778 | goto resolved; | |
1779 | ||
1780 | /* Modifiers */ | |
1781 | case BTF_KIND_TYPEDEF: | |
1782 | case BTF_KIND_VOLATILE: | |
1783 | case BTF_KIND_CONST: | |
1784 | case BTF_KIND_RESTRICT: | |
8c42d2fa | 1785 | case BTF_KIND_TYPE_TAG: |
887c31a3 | 1786 | id = type->type; |
7e3617a7 MKL |
1787 | type = btf_type_by_id(btf, type->type); |
1788 | break; | |
1789 | ||
1790 | case BTF_KIND_ARRAY: | |
1791 | if (!array_type) | |
1792 | array_type = type; | |
1793 | array = btf_type_array(type); | |
1794 | if (nelems && array->nelems > U32_MAX / nelems) | |
1795 | return ERR_PTR(-EINVAL); | |
1796 | nelems *= array->nelems; | |
1797 | type = btf_type_by_id(btf, array->type); | |
1798 | break; | |
1799 | ||
1800 | /* type without size */ | |
1801 | default: | |
1802 | return ERR_PTR(-EINVAL); | |
1803 | } | |
1804 | } | |
1805 | ||
1806 | return ERR_PTR(-EINVAL); | |
1807 | ||
1808 | resolved: | |
1809 | if (nelems && size > U32_MAX / nelems) | |
1810 | return ERR_PTR(-EINVAL); | |
1811 | ||
1812 | *type_size = nelems * size; | |
85d33df3 MKL |
1813 | if (total_nelems) |
1814 | *total_nelems = nelems; | |
1815 | if (elem_type) | |
1816 | *elem_type = type; | |
69ff3047 JO |
1817 | if (elem_id) |
1818 | *elem_id = array ? array->type : 0; | |
887c31a3 JO |
1819 | if (type_id && id) |
1820 | *type_id = id; | |
7e3617a7 MKL |
1821 | |
1822 | return array_type ? : type; | |
1823 | } | |
1824 | ||
6298399b JO |
1825 | const struct btf_type * |
1826 | btf_resolve_size(const struct btf *btf, const struct btf_type *type, | |
1827 | u32 *type_size) | |
1828 | { | |
887c31a3 | 1829 | return __btf_resolve_size(btf, type, type_size, NULL, NULL, NULL, NULL); |
6298399b JO |
1830 | } |
1831 | ||
951bb646 AN |
1832 | static u32 btf_resolved_type_id(const struct btf *btf, u32 type_id) |
1833 | { | |
1834 | while (type_id < btf->start_id) | |
1835 | btf = btf->base_btf; | |
1836 | ||
1837 | return btf->resolved_ids[type_id - btf->start_id]; | |
1838 | } | |
1839 | ||
eb3f595d MKL |
1840 | /* The input param "type_id" must point to a needs_resolve type */ |
1841 | static const struct btf_type *btf_type_id_resolve(const struct btf *btf, | |
1842 | u32 *type_id) | |
1843 | { | |
951bb646 | 1844 | *type_id = btf_resolved_type_id(btf, *type_id); |
eb3f595d MKL |
1845 | return btf_type_by_id(btf, *type_id); |
1846 | } | |
1847 | ||
951bb646 AN |
1848 | static u32 btf_resolved_type_size(const struct btf *btf, u32 type_id) |
1849 | { | |
1850 | while (type_id < btf->start_id) | |
1851 | btf = btf->base_btf; | |
1852 | ||
1853 | return btf->resolved_sizes[type_id - btf->start_id]; | |
1854 | } | |
1855 | ||
eb3f595d MKL |
1856 | const struct btf_type *btf_type_id_size(const struct btf *btf, |
1857 | u32 *type_id, u32 *ret_size) | |
1858 | { | |
1859 | const struct btf_type *size_type; | |
1860 | u32 size_type_id = *type_id; | |
1861 | u32 size = 0; | |
1862 | ||
1863 | size_type = btf_type_by_id(btf, size_type_id); | |
b47a0bd2 | 1864 | if (btf_type_nosize_or_null(size_type)) |
eb3f595d MKL |
1865 | return NULL; |
1866 | ||
1867 | if (btf_type_has_size(size_type)) { | |
1868 | size = size_type->size; | |
1869 | } else if (btf_type_is_array(size_type)) { | |
951bb646 | 1870 | size = btf_resolved_type_size(btf, size_type_id); |
eb3f595d MKL |
1871 | } else if (btf_type_is_ptr(size_type)) { |
1872 | size = sizeof(void *); | |
1873 | } else { | |
1dc92851 DB |
1874 | if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) && |
1875 | !btf_type_is_var(size_type))) | |
eb3f595d MKL |
1876 | return NULL; |
1877 | ||
951bb646 | 1878 | size_type_id = btf_resolved_type_id(btf, size_type_id); |
eb3f595d | 1879 | size_type = btf_type_by_id(btf, size_type_id); |
b47a0bd2 | 1880 | if (btf_type_nosize_or_null(size_type)) |
eb3f595d | 1881 | return NULL; |
1acc5d5c AN |
1882 | else if (btf_type_has_size(size_type)) |
1883 | size = size_type->size; | |
1884 | else if (btf_type_is_array(size_type)) | |
951bb646 | 1885 | size = btf_resolved_type_size(btf, size_type_id); |
1acc5d5c AN |
1886 | else if (btf_type_is_ptr(size_type)) |
1887 | size = sizeof(void *); | |
1888 | else | |
1889 | return NULL; | |
eb3f595d MKL |
1890 | } |
1891 | ||
1892 | *type_id = size_type_id; | |
1893 | if (ret_size) | |
1894 | *ret_size = size; | |
1895 | ||
1896 | return size_type; | |
1897 | } | |
1898 | ||
179cde8c MKL |
1899 | static int btf_df_check_member(struct btf_verifier_env *env, |
1900 | const struct btf_type *struct_type, | |
1901 | const struct btf_member *member, | |
1902 | const struct btf_type *member_type) | |
1903 | { | |
1904 | btf_verifier_log_basic(env, struct_type, | |
1905 | "Unsupported check_member"); | |
1906 | return -EINVAL; | |
1907 | } | |
1908 | ||
9d5f9f70 YS |
1909 | static int btf_df_check_kflag_member(struct btf_verifier_env *env, |
1910 | const struct btf_type *struct_type, | |
1911 | const struct btf_member *member, | |
1912 | const struct btf_type *member_type) | |
1913 | { | |
1914 | btf_verifier_log_basic(env, struct_type, | |
1915 | "Unsupported check_kflag_member"); | |
1916 | return -EINVAL; | |
1917 | } | |
1918 | ||
b1828f0b | 1919 | /* Used for ptr, array struct/union and float type members. |
9d5f9f70 YS |
1920 | * int, enum and modifier types have their specific callback functions. |
1921 | */ | |
1922 | static int btf_generic_check_kflag_member(struct btf_verifier_env *env, | |
1923 | const struct btf_type *struct_type, | |
1924 | const struct btf_member *member, | |
1925 | const struct btf_type *member_type) | |
1926 | { | |
1927 | if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) { | |
1928 | btf_verifier_log_member(env, struct_type, member, | |
1929 | "Invalid member bitfield_size"); | |
1930 | return -EINVAL; | |
1931 | } | |
1932 | ||
1933 | /* bitfield size is 0, so member->offset represents bit offset only. | |
1934 | * It is safe to call non kflag check_member variants. | |
1935 | */ | |
1936 | return btf_type_ops(member_type)->check_member(env, struct_type, | |
1937 | member, | |
1938 | member_type); | |
1939 | } | |
1940 | ||
eb3f595d MKL |
1941 | static int btf_df_resolve(struct btf_verifier_env *env, |
1942 | const struct resolve_vertex *v) | |
1943 | { | |
1944 | btf_verifier_log_basic(env, v->t, "Unsupported resolve"); | |
1945 | return -EINVAL; | |
1946 | } | |
1947 | ||
31d0bc81 AM |
1948 | static void btf_df_show(const struct btf *btf, const struct btf_type *t, |
1949 | u32 type_id, void *data, u8 bits_offsets, | |
1950 | struct btf_show *show) | |
b00b8dae | 1951 | { |
31d0bc81 | 1952 | btf_show(show, "<unsupported kind:%u>", BTF_INFO_KIND(t->info)); |
b00b8dae MKL |
1953 | } |
1954 | ||
179cde8c MKL |
1955 | static int btf_int_check_member(struct btf_verifier_env *env, |
1956 | const struct btf_type *struct_type, | |
1957 | const struct btf_member *member, | |
1958 | const struct btf_type *member_type) | |
1959 | { | |
1960 | u32 int_data = btf_type_int(member_type); | |
1961 | u32 struct_bits_off = member->offset; | |
1962 | u32 struct_size = struct_type->size; | |
1963 | u32 nr_copy_bits; | |
1964 | u32 bytes_offset; | |
1965 | ||
1966 | if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) { | |
1967 | btf_verifier_log_member(env, struct_type, member, | |
1968 | "bits_offset exceeds U32_MAX"); | |
1969 | return -EINVAL; | |
1970 | } | |
1971 | ||
1972 | struct_bits_off += BTF_INT_OFFSET(int_data); | |
1973 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
1974 | nr_copy_bits = BTF_INT_BITS(int_data) + | |
1975 | BITS_PER_BYTE_MASKED(struct_bits_off); | |
1976 | ||
b1e8818c | 1977 | if (nr_copy_bits > BITS_PER_U128) { |
179cde8c | 1978 | btf_verifier_log_member(env, struct_type, member, |
b1e8818c | 1979 | "nr_copy_bits exceeds 128"); |
179cde8c MKL |
1980 | return -EINVAL; |
1981 | } | |
1982 | ||
1983 | if (struct_size < bytes_offset || | |
1984 | struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { | |
1985 | btf_verifier_log_member(env, struct_type, member, | |
1986 | "Member exceeds struct_size"); | |
1987 | return -EINVAL; | |
1988 | } | |
1989 | ||
1990 | return 0; | |
1991 | } | |
1992 | ||
9d5f9f70 YS |
1993 | static int btf_int_check_kflag_member(struct btf_verifier_env *env, |
1994 | const struct btf_type *struct_type, | |
1995 | const struct btf_member *member, | |
1996 | const struct btf_type *member_type) | |
1997 | { | |
1998 | u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset; | |
1999 | u32 int_data = btf_type_int(member_type); | |
2000 | u32 struct_size = struct_type->size; | |
2001 | u32 nr_copy_bits; | |
2002 | ||
2003 | /* a regular int type is required for the kflag int member */ | |
2004 | if (!btf_type_int_is_regular(member_type)) { | |
2005 | btf_verifier_log_member(env, struct_type, member, | |
2006 | "Invalid member base type"); | |
2007 | return -EINVAL; | |
2008 | } | |
2009 | ||
2010 | /* check sanity of bitfield size */ | |
2011 | nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); | |
2012 | struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); | |
2013 | nr_int_data_bits = BTF_INT_BITS(int_data); | |
2014 | if (!nr_bits) { | |
2015 | /* Not a bitfield member, member offset must be at byte | |
2016 | * boundary. | |
2017 | */ | |
2018 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2019 | btf_verifier_log_member(env, struct_type, member, | |
2020 | "Invalid member offset"); | |
2021 | return -EINVAL; | |
2022 | } | |
2023 | ||
2024 | nr_bits = nr_int_data_bits; | |
2025 | } else if (nr_bits > nr_int_data_bits) { | |
2026 | btf_verifier_log_member(env, struct_type, member, | |
2027 | "Invalid member bitfield_size"); | |
2028 | return -EINVAL; | |
2029 | } | |
2030 | ||
2031 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2032 | nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off); | |
b1e8818c | 2033 | if (nr_copy_bits > BITS_PER_U128) { |
9d5f9f70 | 2034 | btf_verifier_log_member(env, struct_type, member, |
b1e8818c | 2035 | "nr_copy_bits exceeds 128"); |
9d5f9f70 YS |
2036 | return -EINVAL; |
2037 | } | |
2038 | ||
2039 | if (struct_size < bytes_offset || | |
2040 | struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { | |
2041 | btf_verifier_log_member(env, struct_type, member, | |
2042 | "Member exceeds struct_size"); | |
2043 | return -EINVAL; | |
2044 | } | |
2045 | ||
2046 | return 0; | |
2047 | } | |
2048 | ||
69b693f0 MKL |
2049 | static s32 btf_int_check_meta(struct btf_verifier_env *env, |
2050 | const struct btf_type *t, | |
2051 | u32 meta_left) | |
2052 | { | |
2053 | u32 int_data, nr_bits, meta_needed = sizeof(int_data); | |
2054 | u16 encoding; | |
2055 | ||
2056 | if (meta_left < meta_needed) { | |
2057 | btf_verifier_log_basic(env, t, | |
2058 | "meta_left:%u meta_needed:%u", | |
2059 | meta_left, meta_needed); | |
2060 | return -EINVAL; | |
2061 | } | |
2062 | ||
2063 | if (btf_type_vlen(t)) { | |
2064 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2065 | return -EINVAL; | |
2066 | } | |
2067 | ||
9d5f9f70 YS |
2068 | if (btf_type_kflag(t)) { |
2069 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2070 | return -EINVAL; | |
2071 | } | |
2072 | ||
69b693f0 | 2073 | int_data = btf_type_int(t); |
aea2f7b8 MKL |
2074 | if (int_data & ~BTF_INT_MASK) { |
2075 | btf_verifier_log_basic(env, t, "Invalid int_data:%x", | |
2076 | int_data); | |
2077 | return -EINVAL; | |
2078 | } | |
2079 | ||
69b693f0 MKL |
2080 | nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data); |
2081 | ||
b1e8818c | 2082 | if (nr_bits > BITS_PER_U128) { |
69b693f0 | 2083 | btf_verifier_log_type(env, t, "nr_bits exceeds %zu", |
b1e8818c | 2084 | BITS_PER_U128); |
69b693f0 MKL |
2085 | return -EINVAL; |
2086 | } | |
2087 | ||
2088 | if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) { | |
2089 | btf_verifier_log_type(env, t, "nr_bits exceeds type_size"); | |
2090 | return -EINVAL; | |
2091 | } | |
2092 | ||
aea2f7b8 MKL |
2093 | /* |
2094 | * Only one of the encoding bits is allowed and it | |
2095 | * should be sufficient for the pretty print purpose (i.e. decoding). | |
2096 | * Multiple bits can be allowed later if it is found | |
2097 | * to be insufficient. | |
2098 | */ | |
69b693f0 MKL |
2099 | encoding = BTF_INT_ENCODING(int_data); |
2100 | if (encoding && | |
2101 | encoding != BTF_INT_SIGNED && | |
2102 | encoding != BTF_INT_CHAR && | |
aea2f7b8 | 2103 | encoding != BTF_INT_BOOL) { |
69b693f0 MKL |
2104 | btf_verifier_log_type(env, t, "Unsupported encoding"); |
2105 | return -ENOTSUPP; | |
2106 | } | |
2107 | ||
2108 | btf_verifier_log_type(env, t, NULL); | |
2109 | ||
2110 | return meta_needed; | |
2111 | } | |
2112 | ||
2113 | static void btf_int_log(struct btf_verifier_env *env, | |
2114 | const struct btf_type *t) | |
2115 | { | |
2116 | int int_data = btf_type_int(t); | |
2117 | ||
2118 | btf_verifier_log(env, | |
2119 | "size=%u bits_offset=%u nr_bits=%u encoding=%s", | |
2120 | t->size, BTF_INT_OFFSET(int_data), | |
2121 | BTF_INT_BITS(int_data), | |
2122 | btf_int_encoding_str(BTF_INT_ENCODING(int_data))); | |
2123 | } | |
2124 | ||
31d0bc81 | 2125 | static void btf_int128_print(struct btf_show *show, void *data) |
b1e8818c YS |
2126 | { |
2127 | /* data points to a __int128 number. | |
2128 | * Suppose | |
2129 | * int128_num = *(__int128 *)data; | |
2130 | * The below formulas shows what upper_num and lower_num represents: | |
2131 | * upper_num = int128_num >> 64; | |
2132 | * lower_num = int128_num & 0xffffffffFFFFFFFFULL; | |
2133 | */ | |
2134 | u64 upper_num, lower_num; | |
2135 | ||
2136 | #ifdef __BIG_ENDIAN_BITFIELD | |
2137 | upper_num = *(u64 *)data; | |
2138 | lower_num = *(u64 *)(data + 8); | |
2139 | #else | |
2140 | upper_num = *(u64 *)(data + 8); | |
2141 | lower_num = *(u64 *)data; | |
2142 | #endif | |
2143 | if (upper_num == 0) | |
31d0bc81 | 2144 | btf_show_type_value(show, "0x%llx", lower_num); |
b1e8818c | 2145 | else |
31d0bc81 AM |
2146 | btf_show_type_values(show, "0x%llx%016llx", upper_num, |
2147 | lower_num); | |
b1e8818c YS |
2148 | } |
2149 | ||
2150 | static void btf_int128_shift(u64 *print_num, u16 left_shift_bits, | |
2151 | u16 right_shift_bits) | |
2152 | { | |
2153 | u64 upper_num, lower_num; | |
2154 | ||
2155 | #ifdef __BIG_ENDIAN_BITFIELD | |
2156 | upper_num = print_num[0]; | |
2157 | lower_num = print_num[1]; | |
2158 | #else | |
2159 | upper_num = print_num[1]; | |
2160 | lower_num = print_num[0]; | |
2161 | #endif | |
2162 | ||
2163 | /* shake out un-needed bits by shift/or operations */ | |
2164 | if (left_shift_bits >= 64) { | |
2165 | upper_num = lower_num << (left_shift_bits - 64); | |
2166 | lower_num = 0; | |
2167 | } else { | |
2168 | upper_num = (upper_num << left_shift_bits) | | |
2169 | (lower_num >> (64 - left_shift_bits)); | |
2170 | lower_num = lower_num << left_shift_bits; | |
2171 | } | |
2172 | ||
2173 | if (right_shift_bits >= 64) { | |
2174 | lower_num = upper_num >> (right_shift_bits - 64); | |
2175 | upper_num = 0; | |
2176 | } else { | |
2177 | lower_num = (lower_num >> right_shift_bits) | | |
2178 | (upper_num << (64 - right_shift_bits)); | |
2179 | upper_num = upper_num >> right_shift_bits; | |
2180 | } | |
2181 | ||
2182 | #ifdef __BIG_ENDIAN_BITFIELD | |
2183 | print_num[0] = upper_num; | |
2184 | print_num[1] = lower_num; | |
2185 | #else | |
2186 | print_num[0] = lower_num; | |
2187 | print_num[1] = upper_num; | |
2188 | #endif | |
2189 | } | |
2190 | ||
31d0bc81 AM |
2191 | static void btf_bitfield_show(void *data, u8 bits_offset, |
2192 | u8 nr_bits, struct btf_show *show) | |
b00b8dae | 2193 | { |
b65f370d | 2194 | u16 left_shift_bits, right_shift_bits; |
36fc3c8c MKL |
2195 | u8 nr_copy_bytes; |
2196 | u8 nr_copy_bits; | |
b1e8818c | 2197 | u64 print_num[2] = {}; |
b00b8dae | 2198 | |
b00b8dae MKL |
2199 | nr_copy_bits = nr_bits + bits_offset; |
2200 | nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits); | |
2201 | ||
b1e8818c | 2202 | memcpy(print_num, data, nr_copy_bytes); |
b00b8dae | 2203 | |
b65f370d OK |
2204 | #ifdef __BIG_ENDIAN_BITFIELD |
2205 | left_shift_bits = bits_offset; | |
2206 | #else | |
b1e8818c | 2207 | left_shift_bits = BITS_PER_U128 - nr_copy_bits; |
b65f370d | 2208 | #endif |
b1e8818c | 2209 | right_shift_bits = BITS_PER_U128 - nr_bits; |
b00b8dae | 2210 | |
b1e8818c | 2211 | btf_int128_shift(print_num, left_shift_bits, right_shift_bits); |
31d0bc81 | 2212 | btf_int128_print(show, print_num); |
b00b8dae MKL |
2213 | } |
2214 | ||
9d5f9f70 | 2215 | |
31d0bc81 AM |
2216 | static void btf_int_bits_show(const struct btf *btf, |
2217 | const struct btf_type *t, | |
2218 | void *data, u8 bits_offset, | |
2219 | struct btf_show *show) | |
f97be3ab YS |
2220 | { |
2221 | u32 int_data = btf_type_int(t); | |
2222 | u8 nr_bits = BTF_INT_BITS(int_data); | |
2223 | u8 total_bits_offset; | |
2224 | ||
2225 | /* | |
2226 | * bits_offset is at most 7. | |
b1e8818c | 2227 | * BTF_INT_OFFSET() cannot exceed 128 bits. |
f97be3ab YS |
2228 | */ |
2229 | total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data); | |
17e3ac81 YS |
2230 | data += BITS_ROUNDDOWN_BYTES(total_bits_offset); |
2231 | bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset); | |
31d0bc81 | 2232 | btf_bitfield_show(data, bits_offset, nr_bits, show); |
f97be3ab YS |
2233 | } |
2234 | ||
31d0bc81 AM |
2235 | static void btf_int_show(const struct btf *btf, const struct btf_type *t, |
2236 | u32 type_id, void *data, u8 bits_offset, | |
2237 | struct btf_show *show) | |
b00b8dae MKL |
2238 | { |
2239 | u32 int_data = btf_type_int(t); | |
2240 | u8 encoding = BTF_INT_ENCODING(int_data); | |
2241 | bool sign = encoding & BTF_INT_SIGNED; | |
36fc3c8c | 2242 | u8 nr_bits = BTF_INT_BITS(int_data); |
31d0bc81 AM |
2243 | void *safe_data; |
2244 | ||
2245 | safe_data = btf_show_start_type(show, t, type_id, data); | |
2246 | if (!safe_data) | |
2247 | return; | |
b00b8dae MKL |
2248 | |
2249 | if (bits_offset || BTF_INT_OFFSET(int_data) || | |
2250 | BITS_PER_BYTE_MASKED(nr_bits)) { | |
31d0bc81 AM |
2251 | btf_int_bits_show(btf, t, safe_data, bits_offset, show); |
2252 | goto out; | |
b00b8dae MKL |
2253 | } |
2254 | ||
2255 | switch (nr_bits) { | |
b1e8818c | 2256 | case 128: |
31d0bc81 | 2257 | btf_int128_print(show, safe_data); |
b1e8818c | 2258 | break; |
b00b8dae MKL |
2259 | case 64: |
2260 | if (sign) | |
31d0bc81 | 2261 | btf_show_type_value(show, "%lld", *(s64 *)safe_data); |
b00b8dae | 2262 | else |
31d0bc81 | 2263 | btf_show_type_value(show, "%llu", *(u64 *)safe_data); |
b00b8dae MKL |
2264 | break; |
2265 | case 32: | |
2266 | if (sign) | |
31d0bc81 | 2267 | btf_show_type_value(show, "%d", *(s32 *)safe_data); |
b00b8dae | 2268 | else |
31d0bc81 | 2269 | btf_show_type_value(show, "%u", *(u32 *)safe_data); |
b00b8dae MKL |
2270 | break; |
2271 | case 16: | |
2272 | if (sign) | |
31d0bc81 | 2273 | btf_show_type_value(show, "%d", *(s16 *)safe_data); |
b00b8dae | 2274 | else |
31d0bc81 | 2275 | btf_show_type_value(show, "%u", *(u16 *)safe_data); |
b00b8dae MKL |
2276 | break; |
2277 | case 8: | |
31d0bc81 AM |
2278 | if (show->state.array_encoding == BTF_INT_CHAR) { |
2279 | /* check for null terminator */ | |
2280 | if (show->state.array_terminated) | |
2281 | break; | |
2282 | if (*(char *)data == '\0') { | |
2283 | show->state.array_terminated = 1; | |
2284 | break; | |
2285 | } | |
2286 | if (isprint(*(char *)data)) { | |
2287 | btf_show_type_value(show, "'%c'", | |
2288 | *(char *)safe_data); | |
2289 | break; | |
2290 | } | |
2291 | } | |
b00b8dae | 2292 | if (sign) |
31d0bc81 | 2293 | btf_show_type_value(show, "%d", *(s8 *)safe_data); |
b00b8dae | 2294 | else |
31d0bc81 | 2295 | btf_show_type_value(show, "%u", *(u8 *)safe_data); |
b00b8dae MKL |
2296 | break; |
2297 | default: | |
31d0bc81 AM |
2298 | btf_int_bits_show(btf, t, safe_data, bits_offset, show); |
2299 | break; | |
b00b8dae | 2300 | } |
31d0bc81 AM |
2301 | out: |
2302 | btf_show_end_type(show); | |
b00b8dae MKL |
2303 | } |
2304 | ||
69b693f0 MKL |
2305 | static const struct btf_kind_operations int_ops = { |
2306 | .check_meta = btf_int_check_meta, | |
eb3f595d | 2307 | .resolve = btf_df_resolve, |
179cde8c | 2308 | .check_member = btf_int_check_member, |
9d5f9f70 | 2309 | .check_kflag_member = btf_int_check_kflag_member, |
69b693f0 | 2310 | .log_details = btf_int_log, |
31d0bc81 | 2311 | .show = btf_int_show, |
69b693f0 MKL |
2312 | }; |
2313 | ||
179cde8c MKL |
2314 | static int btf_modifier_check_member(struct btf_verifier_env *env, |
2315 | const struct btf_type *struct_type, | |
2316 | const struct btf_member *member, | |
2317 | const struct btf_type *member_type) | |
2318 | { | |
2319 | const struct btf_type *resolved_type; | |
2320 | u32 resolved_type_id = member->type; | |
2321 | struct btf_member resolved_member; | |
2322 | struct btf *btf = env->btf; | |
2323 | ||
2324 | resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); | |
2325 | if (!resolved_type) { | |
2326 | btf_verifier_log_member(env, struct_type, member, | |
2327 | "Invalid member"); | |
2328 | return -EINVAL; | |
2329 | } | |
2330 | ||
2331 | resolved_member = *member; | |
2332 | resolved_member.type = resolved_type_id; | |
2333 | ||
2334 | return btf_type_ops(resolved_type)->check_member(env, struct_type, | |
2335 | &resolved_member, | |
2336 | resolved_type); | |
2337 | } | |
2338 | ||
9d5f9f70 YS |
2339 | static int btf_modifier_check_kflag_member(struct btf_verifier_env *env, |
2340 | const struct btf_type *struct_type, | |
2341 | const struct btf_member *member, | |
2342 | const struct btf_type *member_type) | |
2343 | { | |
2344 | const struct btf_type *resolved_type; | |
2345 | u32 resolved_type_id = member->type; | |
2346 | struct btf_member resolved_member; | |
2347 | struct btf *btf = env->btf; | |
2348 | ||
2349 | resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); | |
2350 | if (!resolved_type) { | |
2351 | btf_verifier_log_member(env, struct_type, member, | |
2352 | "Invalid member"); | |
2353 | return -EINVAL; | |
2354 | } | |
2355 | ||
2356 | resolved_member = *member; | |
2357 | resolved_member.type = resolved_type_id; | |
2358 | ||
2359 | return btf_type_ops(resolved_type)->check_kflag_member(env, struct_type, | |
2360 | &resolved_member, | |
2361 | resolved_type); | |
2362 | } | |
2363 | ||
179cde8c MKL |
2364 | static int btf_ptr_check_member(struct btf_verifier_env *env, |
2365 | const struct btf_type *struct_type, | |
2366 | const struct btf_member *member, | |
2367 | const struct btf_type *member_type) | |
2368 | { | |
2369 | u32 struct_size, struct_bits_off, bytes_offset; | |
2370 | ||
2371 | struct_size = struct_type->size; | |
2372 | struct_bits_off = member->offset; | |
2373 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2374 | ||
2375 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2376 | btf_verifier_log_member(env, struct_type, member, | |
2377 | "Member is not byte aligned"); | |
2378 | return -EINVAL; | |
2379 | } | |
2380 | ||
2381 | if (struct_size - bytes_offset < sizeof(void *)) { | |
2382 | btf_verifier_log_member(env, struct_type, member, | |
2383 | "Member exceeds struct_size"); | |
2384 | return -EINVAL; | |
2385 | } | |
2386 | ||
2387 | return 0; | |
2388 | } | |
2389 | ||
69b693f0 MKL |
2390 | static int btf_ref_type_check_meta(struct btf_verifier_env *env, |
2391 | const struct btf_type *t, | |
2392 | u32 meta_left) | |
2393 | { | |
8c42d2fa YS |
2394 | const char *value; |
2395 | ||
69b693f0 MKL |
2396 | if (btf_type_vlen(t)) { |
2397 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2398 | return -EINVAL; | |
2399 | } | |
2400 | ||
9d5f9f70 YS |
2401 | if (btf_type_kflag(t)) { |
2402 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2403 | return -EINVAL; | |
2404 | } | |
2405 | ||
aea2f7b8 | 2406 | if (!BTF_TYPE_ID_VALID(t->type)) { |
69b693f0 MKL |
2407 | btf_verifier_log_type(env, t, "Invalid type_id"); |
2408 | return -EINVAL; | |
2409 | } | |
2410 | ||
8c42d2fa | 2411 | /* typedef/type_tag type must have a valid name, and other ref types, |
eb04bbb6 YS |
2412 | * volatile, const, restrict, should have a null name. |
2413 | */ | |
2414 | if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) { | |
2415 | if (!t->name_off || | |
2416 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
2417 | btf_verifier_log_type(env, t, "Invalid name"); | |
2418 | return -EINVAL; | |
2419 | } | |
8c42d2fa YS |
2420 | } else if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPE_TAG) { |
2421 | value = btf_name_by_offset(env->btf, t->name_off); | |
2422 | if (!value || !value[0]) { | |
2423 | btf_verifier_log_type(env, t, "Invalid name"); | |
2424 | return -EINVAL; | |
2425 | } | |
eb04bbb6 YS |
2426 | } else { |
2427 | if (t->name_off) { | |
2428 | btf_verifier_log_type(env, t, "Invalid name"); | |
2429 | return -EINVAL; | |
2430 | } | |
2431 | } | |
2432 | ||
69b693f0 MKL |
2433 | btf_verifier_log_type(env, t, NULL); |
2434 | ||
2435 | return 0; | |
2436 | } | |
2437 | ||
eb3f595d MKL |
2438 | static int btf_modifier_resolve(struct btf_verifier_env *env, |
2439 | const struct resolve_vertex *v) | |
2440 | { | |
2441 | const struct btf_type *t = v->t; | |
2442 | const struct btf_type *next_type; | |
2443 | u32 next_type_id = t->type; | |
2444 | struct btf *btf = env->btf; | |
eb3f595d MKL |
2445 | |
2446 | next_type = btf_type_by_id(btf, next_type_id); | |
1dc92851 | 2447 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
eb3f595d MKL |
2448 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2449 | return -EINVAL; | |
2450 | } | |
2451 | ||
eb3f595d MKL |
2452 | if (!env_type_is_resolve_sink(env, next_type) && |
2453 | !env_type_is_resolved(env, next_type_id)) | |
2454 | return env_stack_push(env, next_type, next_type_id); | |
2455 | ||
2456 | /* Figure out the resolved next_type_id with size. | |
2457 | * They will be stored in the current modifier's | |
2458 | * resolved_ids and resolved_sizes such that it can | |
2459 | * save us a few type-following when we use it later (e.g. in | |
2460 | * pretty print). | |
2461 | */ | |
1acc5d5c | 2462 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
2667a262 MKL |
2463 | if (env_type_is_resolved(env, next_type_id)) |
2464 | next_type = btf_type_id_resolve(btf, &next_type_id); | |
2465 | ||
2466 | /* "typedef void new_void", "const void"...etc */ | |
2467 | if (!btf_type_is_void(next_type) && | |
81f5c6f5 YS |
2468 | !btf_type_is_fwd(next_type) && |
2469 | !btf_type_is_func_proto(next_type)) { | |
2667a262 MKL |
2470 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2471 | return -EINVAL; | |
2472 | } | |
eb3f595d MKL |
2473 | } |
2474 | ||
1acc5d5c | 2475 | env_stack_pop_resolved(env, next_type_id, 0); |
eb3f595d MKL |
2476 | |
2477 | return 0; | |
2478 | } | |
2479 | ||
1dc92851 DB |
2480 | static int btf_var_resolve(struct btf_verifier_env *env, |
2481 | const struct resolve_vertex *v) | |
2482 | { | |
2483 | const struct btf_type *next_type; | |
2484 | const struct btf_type *t = v->t; | |
2485 | u32 next_type_id = t->type; | |
2486 | struct btf *btf = env->btf; | |
1dc92851 DB |
2487 | |
2488 | next_type = btf_type_by_id(btf, next_type_id); | |
2489 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { | |
2490 | btf_verifier_log_type(env, v->t, "Invalid type_id"); | |
2491 | return -EINVAL; | |
2492 | } | |
2493 | ||
2494 | if (!env_type_is_resolve_sink(env, next_type) && | |
2495 | !env_type_is_resolved(env, next_type_id)) | |
2496 | return env_stack_push(env, next_type, next_type_id); | |
2497 | ||
2498 | if (btf_type_is_modifier(next_type)) { | |
2499 | const struct btf_type *resolved_type; | |
2500 | u32 resolved_type_id; | |
2501 | ||
2502 | resolved_type_id = next_type_id; | |
2503 | resolved_type = btf_type_id_resolve(btf, &resolved_type_id); | |
2504 | ||
2505 | if (btf_type_is_ptr(resolved_type) && | |
2506 | !env_type_is_resolve_sink(env, resolved_type) && | |
2507 | !env_type_is_resolved(env, resolved_type_id)) | |
2508 | return env_stack_push(env, resolved_type, | |
2509 | resolved_type_id); | |
2510 | } | |
2511 | ||
2512 | /* We must resolve to something concrete at this point, no | |
2513 | * forward types or similar that would resolve to size of | |
2514 | * zero is allowed. | |
2515 | */ | |
1acc5d5c | 2516 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
1dc92851 DB |
2517 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2518 | return -EINVAL; | |
2519 | } | |
2520 | ||
1acc5d5c | 2521 | env_stack_pop_resolved(env, next_type_id, 0); |
1dc92851 DB |
2522 | |
2523 | return 0; | |
2524 | } | |
2525 | ||
eb3f595d MKL |
2526 | static int btf_ptr_resolve(struct btf_verifier_env *env, |
2527 | const struct resolve_vertex *v) | |
2528 | { | |
2529 | const struct btf_type *next_type; | |
2530 | const struct btf_type *t = v->t; | |
2531 | u32 next_type_id = t->type; | |
2532 | struct btf *btf = env->btf; | |
eb3f595d MKL |
2533 | |
2534 | next_type = btf_type_by_id(btf, next_type_id); | |
1dc92851 | 2535 | if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
eb3f595d MKL |
2536 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
2537 | return -EINVAL; | |
2538 | } | |
2539 | ||
eb3f595d MKL |
2540 | if (!env_type_is_resolve_sink(env, next_type) && |
2541 | !env_type_is_resolved(env, next_type_id)) | |
2542 | return env_stack_push(env, next_type, next_type_id); | |
2543 | ||
2544 | /* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY, | |
2545 | * the modifier may have stopped resolving when it was resolved | |
2546 | * to a ptr (last-resolved-ptr). | |
2547 | * | |
2548 | * We now need to continue from the last-resolved-ptr to | |
2549 | * ensure the last-resolved-ptr will not referring back to | |
c561d110 | 2550 | * the current ptr (t). |
eb3f595d MKL |
2551 | */ |
2552 | if (btf_type_is_modifier(next_type)) { | |
2553 | const struct btf_type *resolved_type; | |
2554 | u32 resolved_type_id; | |
2555 | ||
2556 | resolved_type_id = next_type_id; | |
2557 | resolved_type = btf_type_id_resolve(btf, &resolved_type_id); | |
2558 | ||
2559 | if (btf_type_is_ptr(resolved_type) && | |
2560 | !env_type_is_resolve_sink(env, resolved_type) && | |
2561 | !env_type_is_resolved(env, resolved_type_id)) | |
2562 | return env_stack_push(env, resolved_type, | |
2563 | resolved_type_id); | |
2564 | } | |
2565 | ||
2667a262 MKL |
2566 | if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
2567 | if (env_type_is_resolved(env, next_type_id)) | |
2568 | next_type = btf_type_id_resolve(btf, &next_type_id); | |
2569 | ||
2570 | if (!btf_type_is_void(next_type) && | |
2571 | !btf_type_is_fwd(next_type) && | |
2572 | !btf_type_is_func_proto(next_type)) { | |
2573 | btf_verifier_log_type(env, v->t, "Invalid type_id"); | |
2574 | return -EINVAL; | |
2575 | } | |
eb3f595d MKL |
2576 | } |
2577 | ||
eb3f595d MKL |
2578 | env_stack_pop_resolved(env, next_type_id, 0); |
2579 | ||
2580 | return 0; | |
2581 | } | |
2582 | ||
31d0bc81 AM |
2583 | static void btf_modifier_show(const struct btf *btf, |
2584 | const struct btf_type *t, | |
2585 | u32 type_id, void *data, | |
2586 | u8 bits_offset, struct btf_show *show) | |
b00b8dae | 2587 | { |
85d33df3 MKL |
2588 | if (btf->resolved_ids) |
2589 | t = btf_type_id_resolve(btf, &type_id); | |
2590 | else | |
2591 | t = btf_type_skip_modifiers(btf, type_id, NULL); | |
b00b8dae | 2592 | |
31d0bc81 | 2593 | btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show); |
b00b8dae MKL |
2594 | } |
2595 | ||
31d0bc81 AM |
2596 | static void btf_var_show(const struct btf *btf, const struct btf_type *t, |
2597 | u32 type_id, void *data, u8 bits_offset, | |
2598 | struct btf_show *show) | |
1dc92851 DB |
2599 | { |
2600 | t = btf_type_id_resolve(btf, &type_id); | |
2601 | ||
31d0bc81 | 2602 | btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show); |
1dc92851 DB |
2603 | } |
2604 | ||
31d0bc81 AM |
2605 | static void btf_ptr_show(const struct btf *btf, const struct btf_type *t, |
2606 | u32 type_id, void *data, u8 bits_offset, | |
2607 | struct btf_show *show) | |
b00b8dae | 2608 | { |
31d0bc81 AM |
2609 | void *safe_data; |
2610 | ||
2611 | safe_data = btf_show_start_type(show, t, type_id, data); | |
2612 | if (!safe_data) | |
2613 | return; | |
2614 | ||
2615 | /* It is a hashed value unless BTF_SHOW_PTR_RAW is specified */ | |
2616 | if (show->flags & BTF_SHOW_PTR_RAW) | |
2617 | btf_show_type_value(show, "0x%px", *(void **)safe_data); | |
2618 | else | |
2619 | btf_show_type_value(show, "0x%p", *(void **)safe_data); | |
2620 | btf_show_end_type(show); | |
b00b8dae MKL |
2621 | } |
2622 | ||
69b693f0 MKL |
2623 | static void btf_ref_type_log(struct btf_verifier_env *env, |
2624 | const struct btf_type *t) | |
2625 | { | |
2626 | btf_verifier_log(env, "type_id=%u", t->type); | |
2627 | } | |
2628 | ||
2629 | static struct btf_kind_operations modifier_ops = { | |
2630 | .check_meta = btf_ref_type_check_meta, | |
eb3f595d | 2631 | .resolve = btf_modifier_resolve, |
179cde8c | 2632 | .check_member = btf_modifier_check_member, |
9d5f9f70 | 2633 | .check_kflag_member = btf_modifier_check_kflag_member, |
69b693f0 | 2634 | .log_details = btf_ref_type_log, |
31d0bc81 | 2635 | .show = btf_modifier_show, |
69b693f0 MKL |
2636 | }; |
2637 | ||
2638 | static struct btf_kind_operations ptr_ops = { | |
2639 | .check_meta = btf_ref_type_check_meta, | |
eb3f595d | 2640 | .resolve = btf_ptr_resolve, |
179cde8c | 2641 | .check_member = btf_ptr_check_member, |
9d5f9f70 | 2642 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 2643 | .log_details = btf_ref_type_log, |
31d0bc81 | 2644 | .show = btf_ptr_show, |
69b693f0 MKL |
2645 | }; |
2646 | ||
8175383f MKL |
2647 | static s32 btf_fwd_check_meta(struct btf_verifier_env *env, |
2648 | const struct btf_type *t, | |
2649 | u32 meta_left) | |
2650 | { | |
2651 | if (btf_type_vlen(t)) { | |
2652 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2653 | return -EINVAL; | |
2654 | } | |
2655 | ||
2656 | if (t->type) { | |
2657 | btf_verifier_log_type(env, t, "type != 0"); | |
2658 | return -EINVAL; | |
2659 | } | |
2660 | ||
eb04bbb6 YS |
2661 | /* fwd type must have a valid name */ |
2662 | if (!t->name_off || | |
2663 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
2664 | btf_verifier_log_type(env, t, "Invalid name"); | |
2665 | return -EINVAL; | |
2666 | } | |
2667 | ||
8175383f MKL |
2668 | btf_verifier_log_type(env, t, NULL); |
2669 | ||
2670 | return 0; | |
2671 | } | |
2672 | ||
76c43ae8 YS |
2673 | static void btf_fwd_type_log(struct btf_verifier_env *env, |
2674 | const struct btf_type *t) | |
2675 | { | |
2676 | btf_verifier_log(env, "%s", btf_type_kflag(t) ? "union" : "struct"); | |
2677 | } | |
2678 | ||
69b693f0 | 2679 | static struct btf_kind_operations fwd_ops = { |
8175383f | 2680 | .check_meta = btf_fwd_check_meta, |
eb3f595d | 2681 | .resolve = btf_df_resolve, |
179cde8c | 2682 | .check_member = btf_df_check_member, |
9d5f9f70 | 2683 | .check_kflag_member = btf_df_check_kflag_member, |
76c43ae8 | 2684 | .log_details = btf_fwd_type_log, |
31d0bc81 | 2685 | .show = btf_df_show, |
69b693f0 MKL |
2686 | }; |
2687 | ||
179cde8c MKL |
2688 | static int btf_array_check_member(struct btf_verifier_env *env, |
2689 | const struct btf_type *struct_type, | |
2690 | const struct btf_member *member, | |
2691 | const struct btf_type *member_type) | |
2692 | { | |
2693 | u32 struct_bits_off = member->offset; | |
2694 | u32 struct_size, bytes_offset; | |
2695 | u32 array_type_id, array_size; | |
2696 | struct btf *btf = env->btf; | |
2697 | ||
2698 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2699 | btf_verifier_log_member(env, struct_type, member, | |
2700 | "Member is not byte aligned"); | |
2701 | return -EINVAL; | |
2702 | } | |
2703 | ||
2704 | array_type_id = member->type; | |
2705 | btf_type_id_size(btf, &array_type_id, &array_size); | |
2706 | struct_size = struct_type->size; | |
2707 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2708 | if (struct_size - bytes_offset < array_size) { | |
2709 | btf_verifier_log_member(env, struct_type, member, | |
2710 | "Member exceeds struct_size"); | |
2711 | return -EINVAL; | |
2712 | } | |
2713 | ||
2714 | return 0; | |
2715 | } | |
2716 | ||
69b693f0 MKL |
2717 | static s32 btf_array_check_meta(struct btf_verifier_env *env, |
2718 | const struct btf_type *t, | |
2719 | u32 meta_left) | |
2720 | { | |
2721 | const struct btf_array *array = btf_type_array(t); | |
2722 | u32 meta_needed = sizeof(*array); | |
2723 | ||
2724 | if (meta_left < meta_needed) { | |
2725 | btf_verifier_log_basic(env, t, | |
2726 | "meta_left:%u meta_needed:%u", | |
2727 | meta_left, meta_needed); | |
2728 | return -EINVAL; | |
2729 | } | |
2730 | ||
eb04bbb6 YS |
2731 | /* array type should not have a name */ |
2732 | if (t->name_off) { | |
2733 | btf_verifier_log_type(env, t, "Invalid name"); | |
2734 | return -EINVAL; | |
2735 | } | |
2736 | ||
69b693f0 MKL |
2737 | if (btf_type_vlen(t)) { |
2738 | btf_verifier_log_type(env, t, "vlen != 0"); | |
2739 | return -EINVAL; | |
2740 | } | |
2741 | ||
9d5f9f70 YS |
2742 | if (btf_type_kflag(t)) { |
2743 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
2744 | return -EINVAL; | |
2745 | } | |
2746 | ||
b9308ae6 MKL |
2747 | if (t->size) { |
2748 | btf_verifier_log_type(env, t, "size != 0"); | |
2749 | return -EINVAL; | |
2750 | } | |
2751 | ||
4ef5f574 MKL |
2752 | /* Array elem type and index type cannot be in type void, |
2753 | * so !array->type and !array->index_type are not allowed. | |
69b693f0 | 2754 | */ |
aea2f7b8 | 2755 | if (!array->type || !BTF_TYPE_ID_VALID(array->type)) { |
4ef5f574 MKL |
2756 | btf_verifier_log_type(env, t, "Invalid elem"); |
2757 | return -EINVAL; | |
2758 | } | |
2759 | ||
aea2f7b8 | 2760 | if (!array->index_type || !BTF_TYPE_ID_VALID(array->index_type)) { |
4ef5f574 | 2761 | btf_verifier_log_type(env, t, "Invalid index"); |
69b693f0 MKL |
2762 | return -EINVAL; |
2763 | } | |
2764 | ||
2765 | btf_verifier_log_type(env, t, NULL); | |
2766 | ||
2767 | return meta_needed; | |
2768 | } | |
2769 | ||
eb3f595d MKL |
2770 | static int btf_array_resolve(struct btf_verifier_env *env, |
2771 | const struct resolve_vertex *v) | |
2772 | { | |
2773 | const struct btf_array *array = btf_type_array(v->t); | |
4ef5f574 MKL |
2774 | const struct btf_type *elem_type, *index_type; |
2775 | u32 elem_type_id, index_type_id; | |
eb3f595d MKL |
2776 | struct btf *btf = env->btf; |
2777 | u32 elem_size; | |
2778 | ||
4ef5f574 MKL |
2779 | /* Check array->index_type */ |
2780 | index_type_id = array->index_type; | |
2781 | index_type = btf_type_by_id(btf, index_type_id); | |
e4f07120 SF |
2782 | if (btf_type_nosize_or_null(index_type) || |
2783 | btf_type_is_resolve_source_only(index_type)) { | |
4ef5f574 MKL |
2784 | btf_verifier_log_type(env, v->t, "Invalid index"); |
2785 | return -EINVAL; | |
2786 | } | |
2787 | ||
2788 | if (!env_type_is_resolve_sink(env, index_type) && | |
2789 | !env_type_is_resolved(env, index_type_id)) | |
2790 | return env_stack_push(env, index_type, index_type_id); | |
2791 | ||
2792 | index_type = btf_type_id_size(btf, &index_type_id, NULL); | |
2793 | if (!index_type || !btf_type_is_int(index_type) || | |
2794 | !btf_type_int_is_regular(index_type)) { | |
2795 | btf_verifier_log_type(env, v->t, "Invalid index"); | |
2796 | return -EINVAL; | |
2797 | } | |
2798 | ||
2799 | /* Check array->type */ | |
2800 | elem_type_id = array->type; | |
eb3f595d | 2801 | elem_type = btf_type_by_id(btf, elem_type_id); |
e4f07120 SF |
2802 | if (btf_type_nosize_or_null(elem_type) || |
2803 | btf_type_is_resolve_source_only(elem_type)) { | |
eb3f595d MKL |
2804 | btf_verifier_log_type(env, v->t, |
2805 | "Invalid elem"); | |
2806 | return -EINVAL; | |
2807 | } | |
2808 | ||
2809 | if (!env_type_is_resolve_sink(env, elem_type) && | |
2810 | !env_type_is_resolved(env, elem_type_id)) | |
2811 | return env_stack_push(env, elem_type, elem_type_id); | |
2812 | ||
2813 | elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); | |
2814 | if (!elem_type) { | |
2815 | btf_verifier_log_type(env, v->t, "Invalid elem"); | |
2816 | return -EINVAL; | |
2817 | } | |
2818 | ||
4ef5f574 MKL |
2819 | if (btf_type_is_int(elem_type) && !btf_type_int_is_regular(elem_type)) { |
2820 | btf_verifier_log_type(env, v->t, "Invalid array of int"); | |
2821 | return -EINVAL; | |
eb3f595d MKL |
2822 | } |
2823 | ||
2824 | if (array->nelems && elem_size > U32_MAX / array->nelems) { | |
2825 | btf_verifier_log_type(env, v->t, | |
2826 | "Array size overflows U32_MAX"); | |
2827 | return -EINVAL; | |
2828 | } | |
2829 | ||
2830 | env_stack_pop_resolved(env, elem_type_id, elem_size * array->nelems); | |
2831 | ||
2832 | return 0; | |
2833 | } | |
2834 | ||
69b693f0 MKL |
2835 | static void btf_array_log(struct btf_verifier_env *env, |
2836 | const struct btf_type *t) | |
2837 | { | |
2838 | const struct btf_array *array = btf_type_array(t); | |
2839 | ||
2840 | btf_verifier_log(env, "type_id=%u index_type_id=%u nr_elems=%u", | |
2841 | array->type, array->index_type, array->nelems); | |
2842 | } | |
2843 | ||
31d0bc81 AM |
2844 | static void __btf_array_show(const struct btf *btf, const struct btf_type *t, |
2845 | u32 type_id, void *data, u8 bits_offset, | |
2846 | struct btf_show *show) | |
b00b8dae MKL |
2847 | { |
2848 | const struct btf_array *array = btf_type_array(t); | |
2849 | const struct btf_kind_operations *elem_ops; | |
2850 | const struct btf_type *elem_type; | |
31d0bc81 AM |
2851 | u32 i, elem_size = 0, elem_type_id; |
2852 | u16 encoding = 0; | |
b00b8dae MKL |
2853 | |
2854 | elem_type_id = array->type; | |
31d0bc81 AM |
2855 | elem_type = btf_type_skip_modifiers(btf, elem_type_id, NULL); |
2856 | if (elem_type && btf_type_has_size(elem_type)) | |
2857 | elem_size = elem_type->size; | |
2858 | ||
2859 | if (elem_type && btf_type_is_int(elem_type)) { | |
2860 | u32 int_type = btf_type_int(elem_type); | |
2861 | ||
2862 | encoding = BTF_INT_ENCODING(int_type); | |
2863 | ||
2864 | /* | |
2865 | * BTF_INT_CHAR encoding never seems to be set for | |
2866 | * char arrays, so if size is 1 and element is | |
2867 | * printable as a char, we'll do that. | |
2868 | */ | |
2869 | if (elem_size == 1) | |
2870 | encoding = BTF_INT_CHAR; | |
2871 | } | |
2872 | ||
2873 | if (!btf_show_start_array_type(show, t, type_id, encoding, data)) | |
2874 | return; | |
2875 | ||
2876 | if (!elem_type) | |
2877 | goto out; | |
b00b8dae | 2878 | elem_ops = btf_type_ops(elem_type); |
31d0bc81 | 2879 | |
b00b8dae | 2880 | for (i = 0; i < array->nelems; i++) { |
b00b8dae | 2881 | |
31d0bc81 AM |
2882 | btf_show_start_array_member(show); |
2883 | ||
2884 | elem_ops->show(btf, elem_type, elem_type_id, data, | |
2885 | bits_offset, show); | |
b00b8dae | 2886 | data += elem_size; |
31d0bc81 AM |
2887 | |
2888 | btf_show_end_array_member(show); | |
2889 | ||
2890 | if (show->state.array_terminated) | |
2891 | break; | |
b00b8dae | 2892 | } |
31d0bc81 AM |
2893 | out: |
2894 | btf_show_end_array_type(show); | |
2895 | } | |
2896 | ||
2897 | static void btf_array_show(const struct btf *btf, const struct btf_type *t, | |
2898 | u32 type_id, void *data, u8 bits_offset, | |
2899 | struct btf_show *show) | |
2900 | { | |
2901 | const struct btf_member *m = show->state.member; | |
2902 | ||
2903 | /* | |
2904 | * First check if any members would be shown (are non-zero). | |
2905 | * See comments above "struct btf_show" definition for more | |
2906 | * details on how this works at a high-level. | |
2907 | */ | |
2908 | if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) { | |
2909 | if (!show->state.depth_check) { | |
2910 | show->state.depth_check = show->state.depth + 1; | |
2911 | show->state.depth_to_show = 0; | |
2912 | } | |
2913 | __btf_array_show(btf, t, type_id, data, bits_offset, show); | |
2914 | show->state.member = m; | |
2915 | ||
2916 | if (show->state.depth_check != show->state.depth + 1) | |
2917 | return; | |
2918 | show->state.depth_check = 0; | |
2919 | ||
2920 | if (show->state.depth_to_show <= show->state.depth) | |
2921 | return; | |
2922 | /* | |
2923 | * Reaching here indicates we have recursed and found | |
2924 | * non-zero array member(s). | |
2925 | */ | |
2926 | } | |
2927 | __btf_array_show(btf, t, type_id, data, bits_offset, show); | |
b00b8dae MKL |
2928 | } |
2929 | ||
69b693f0 MKL |
2930 | static struct btf_kind_operations array_ops = { |
2931 | .check_meta = btf_array_check_meta, | |
eb3f595d | 2932 | .resolve = btf_array_resolve, |
179cde8c | 2933 | .check_member = btf_array_check_member, |
9d5f9f70 | 2934 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 2935 | .log_details = btf_array_log, |
31d0bc81 | 2936 | .show = btf_array_show, |
69b693f0 MKL |
2937 | }; |
2938 | ||
179cde8c MKL |
2939 | static int btf_struct_check_member(struct btf_verifier_env *env, |
2940 | const struct btf_type *struct_type, | |
2941 | const struct btf_member *member, | |
2942 | const struct btf_type *member_type) | |
2943 | { | |
2944 | u32 struct_bits_off = member->offset; | |
2945 | u32 struct_size, bytes_offset; | |
2946 | ||
2947 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
2948 | btf_verifier_log_member(env, struct_type, member, | |
2949 | "Member is not byte aligned"); | |
2950 | return -EINVAL; | |
2951 | } | |
2952 | ||
2953 | struct_size = struct_type->size; | |
2954 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
2955 | if (struct_size - bytes_offset < member_type->size) { | |
2956 | btf_verifier_log_member(env, struct_type, member, | |
2957 | "Member exceeds struct_size"); | |
2958 | return -EINVAL; | |
2959 | } | |
2960 | ||
2961 | return 0; | |
2962 | } | |
2963 | ||
69b693f0 MKL |
2964 | static s32 btf_struct_check_meta(struct btf_verifier_env *env, |
2965 | const struct btf_type *t, | |
2966 | u32 meta_left) | |
2967 | { | |
2968 | bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION; | |
2969 | const struct btf_member *member; | |
6283fa38 | 2970 | u32 meta_needed, last_offset; |
69b693f0 MKL |
2971 | struct btf *btf = env->btf; |
2972 | u32 struct_size = t->size; | |
9d5f9f70 | 2973 | u32 offset; |
69b693f0 MKL |
2974 | u16 i; |
2975 | ||
2976 | meta_needed = btf_type_vlen(t) * sizeof(*member); | |
2977 | if (meta_left < meta_needed) { | |
2978 | btf_verifier_log_basic(env, t, | |
2979 | "meta_left:%u meta_needed:%u", | |
2980 | meta_left, meta_needed); | |
2981 | return -EINVAL; | |
2982 | } | |
2983 | ||
eb04bbb6 YS |
2984 | /* struct type either no name or a valid one */ |
2985 | if (t->name_off && | |
2986 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
2987 | btf_verifier_log_type(env, t, "Invalid name"); | |
2988 | return -EINVAL; | |
2989 | } | |
2990 | ||
69b693f0 MKL |
2991 | btf_verifier_log_type(env, t, NULL); |
2992 | ||
6283fa38 | 2993 | last_offset = 0; |
69b693f0 | 2994 | for_each_member(i, t, member) { |
fbcf93eb | 2995 | if (!btf_name_offset_valid(btf, member->name_off)) { |
69b693f0 MKL |
2996 | btf_verifier_log_member(env, t, member, |
2997 | "Invalid member name_offset:%u", | |
fbcf93eb | 2998 | member->name_off); |
69b693f0 MKL |
2999 | return -EINVAL; |
3000 | } | |
3001 | ||
eb04bbb6 YS |
3002 | /* struct member either no name or a valid one */ |
3003 | if (member->name_off && | |
3004 | !btf_name_valid_identifier(btf, member->name_off)) { | |
3005 | btf_verifier_log_member(env, t, member, "Invalid name"); | |
3006 | return -EINVAL; | |
3007 | } | |
69b693f0 | 3008 | /* A member cannot be in type void */ |
aea2f7b8 | 3009 | if (!member->type || !BTF_TYPE_ID_VALID(member->type)) { |
69b693f0 MKL |
3010 | btf_verifier_log_member(env, t, member, |
3011 | "Invalid type_id"); | |
3012 | return -EINVAL; | |
3013 | } | |
3014 | ||
8293eb99 | 3015 | offset = __btf_member_bit_offset(t, member); |
9d5f9f70 | 3016 | if (is_union && offset) { |
69b693f0 MKL |
3017 | btf_verifier_log_member(env, t, member, |
3018 | "Invalid member bits_offset"); | |
3019 | return -EINVAL; | |
3020 | } | |
3021 | ||
6283fa38 MKL |
3022 | /* |
3023 | * ">" instead of ">=" because the last member could be | |
3024 | * "char a[0];" | |
3025 | */ | |
9d5f9f70 | 3026 | if (last_offset > offset) { |
6283fa38 MKL |
3027 | btf_verifier_log_member(env, t, member, |
3028 | "Invalid member bits_offset"); | |
3029 | return -EINVAL; | |
3030 | } | |
3031 | ||
9d5f9f70 | 3032 | if (BITS_ROUNDUP_BYTES(offset) > struct_size) { |
69b693f0 | 3033 | btf_verifier_log_member(env, t, member, |
311fe1a8 | 3034 | "Member bits_offset exceeds its struct size"); |
69b693f0 MKL |
3035 | return -EINVAL; |
3036 | } | |
3037 | ||
3038 | btf_verifier_log_member(env, t, member, NULL); | |
9d5f9f70 | 3039 | last_offset = offset; |
69b693f0 MKL |
3040 | } |
3041 | ||
3042 | return meta_needed; | |
3043 | } | |
3044 | ||
eb3f595d MKL |
3045 | static int btf_struct_resolve(struct btf_verifier_env *env, |
3046 | const struct resolve_vertex *v) | |
3047 | { | |
3048 | const struct btf_member *member; | |
179cde8c | 3049 | int err; |
eb3f595d MKL |
3050 | u16 i; |
3051 | ||
3052 | /* Before continue resolving the next_member, | |
3053 | * ensure the last member is indeed resolved to a | |
3054 | * type with size info. | |
3055 | */ | |
3056 | if (v->next_member) { | |
179cde8c | 3057 | const struct btf_type *last_member_type; |
eb3f595d MKL |
3058 | const struct btf_member *last_member; |
3059 | u16 last_member_type_id; | |
3060 | ||
3061 | last_member = btf_type_member(v->t) + v->next_member - 1; | |
3062 | last_member_type_id = last_member->type; | |
3063 | if (WARN_ON_ONCE(!env_type_is_resolved(env, | |
3064 | last_member_type_id))) | |
3065 | return -EINVAL; | |
179cde8c MKL |
3066 | |
3067 | last_member_type = btf_type_by_id(env->btf, | |
3068 | last_member_type_id); | |
9d5f9f70 YS |
3069 | if (btf_type_kflag(v->t)) |
3070 | err = btf_type_ops(last_member_type)->check_kflag_member(env, v->t, | |
3071 | last_member, | |
3072 | last_member_type); | |
3073 | else | |
3074 | err = btf_type_ops(last_member_type)->check_member(env, v->t, | |
3075 | last_member, | |
3076 | last_member_type); | |
179cde8c MKL |
3077 | if (err) |
3078 | return err; | |
eb3f595d MKL |
3079 | } |
3080 | ||
3081 | for_each_member_from(i, v->next_member, v->t, member) { | |
3082 | u32 member_type_id = member->type; | |
3083 | const struct btf_type *member_type = btf_type_by_id(env->btf, | |
3084 | member_type_id); | |
3085 | ||
e4f07120 SF |
3086 | if (btf_type_nosize_or_null(member_type) || |
3087 | btf_type_is_resolve_source_only(member_type)) { | |
eb3f595d MKL |
3088 | btf_verifier_log_member(env, v->t, member, |
3089 | "Invalid member"); | |
3090 | return -EINVAL; | |
3091 | } | |
3092 | ||
3093 | if (!env_type_is_resolve_sink(env, member_type) && | |
3094 | !env_type_is_resolved(env, member_type_id)) { | |
3095 | env_stack_set_next_member(env, i + 1); | |
3096 | return env_stack_push(env, member_type, member_type_id); | |
3097 | } | |
179cde8c | 3098 | |
9d5f9f70 YS |
3099 | if (btf_type_kflag(v->t)) |
3100 | err = btf_type_ops(member_type)->check_kflag_member(env, v->t, | |
3101 | member, | |
3102 | member_type); | |
3103 | else | |
3104 | err = btf_type_ops(member_type)->check_member(env, v->t, | |
3105 | member, | |
3106 | member_type); | |
179cde8c MKL |
3107 | if (err) |
3108 | return err; | |
eb3f595d MKL |
3109 | } |
3110 | ||
3111 | env_stack_pop_resolved(env, 0, 0); | |
3112 | ||
3113 | return 0; | |
3114 | } | |
3115 | ||
69b693f0 MKL |
3116 | static void btf_struct_log(struct btf_verifier_env *env, |
3117 | const struct btf_type *t) | |
3118 | { | |
3119 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
3120 | } | |
3121 | ||
68134668 AS |
3122 | static int btf_find_struct_field(const struct btf *btf, const struct btf_type *t, |
3123 | const char *name, int sz, int align) | |
d83525ca AS |
3124 | { |
3125 | const struct btf_member *member; | |
3126 | u32 i, off = -ENOENT; | |
3127 | ||
d83525ca AS |
3128 | for_each_member(i, t, member) { |
3129 | const struct btf_type *member_type = btf_type_by_id(btf, | |
3130 | member->type); | |
3131 | if (!__btf_type_is_struct(member_type)) | |
3132 | continue; | |
68134668 | 3133 | if (member_type->size != sz) |
d83525ca | 3134 | continue; |
68134668 | 3135 | if (strcmp(__btf_name_by_offset(btf, member_type->name_off), name)) |
d83525ca AS |
3136 | continue; |
3137 | if (off != -ENOENT) | |
68134668 | 3138 | /* only one such field is allowed */ |
d83525ca | 3139 | return -E2BIG; |
8293eb99 | 3140 | off = __btf_member_bit_offset(t, member); |
d83525ca AS |
3141 | if (off % 8) |
3142 | /* valid C code cannot generate such BTF */ | |
3143 | return -EINVAL; | |
3144 | off /= 8; | |
68134668 AS |
3145 | if (off % align) |
3146 | return -EINVAL; | |
3147 | } | |
3148 | return off; | |
3149 | } | |
3150 | ||
3151 | static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t, | |
3152 | const char *name, int sz, int align) | |
3153 | { | |
3154 | const struct btf_var_secinfo *vsi; | |
3155 | u32 i, off = -ENOENT; | |
3156 | ||
3157 | for_each_vsi(i, t, vsi) { | |
3158 | const struct btf_type *var = btf_type_by_id(btf, vsi->type); | |
3159 | const struct btf_type *var_type = btf_type_by_id(btf, var->type); | |
3160 | ||
3161 | if (!__btf_type_is_struct(var_type)) | |
3162 | continue; | |
3163 | if (var_type->size != sz) | |
3164 | continue; | |
3165 | if (vsi->size != sz) | |
3166 | continue; | |
3167 | if (strcmp(__btf_name_by_offset(btf, var_type->name_off), name)) | |
3168 | continue; | |
3169 | if (off != -ENOENT) | |
3170 | /* only one such field is allowed */ | |
3171 | return -E2BIG; | |
3172 | off = vsi->offset; | |
3173 | if (off % align) | |
d83525ca AS |
3174 | return -EINVAL; |
3175 | } | |
3176 | return off; | |
3177 | } | |
3178 | ||
68134668 AS |
3179 | static int btf_find_field(const struct btf *btf, const struct btf_type *t, |
3180 | const char *name, int sz, int align) | |
3181 | { | |
3182 | ||
3183 | if (__btf_type_is_struct(t)) | |
3184 | return btf_find_struct_field(btf, t, name, sz, align); | |
3185 | else if (btf_type_is_datasec(t)) | |
3186 | return btf_find_datasec_var(btf, t, name, sz, align); | |
3187 | return -EINVAL; | |
3188 | } | |
3189 | ||
3190 | /* find 'struct bpf_spin_lock' in map value. | |
3191 | * return >= 0 offset if found | |
3192 | * and < 0 in case of error | |
3193 | */ | |
3194 | int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t) | |
3195 | { | |
3196 | return btf_find_field(btf, t, "bpf_spin_lock", | |
3197 | sizeof(struct bpf_spin_lock), | |
3198 | __alignof__(struct bpf_spin_lock)); | |
3199 | } | |
3200 | ||
3201 | int btf_find_timer(const struct btf *btf, const struct btf_type *t) | |
3202 | { | |
3203 | return btf_find_field(btf, t, "bpf_timer", | |
3204 | sizeof(struct bpf_timer), | |
3205 | __alignof__(struct bpf_timer)); | |
3206 | } | |
3207 | ||
31d0bc81 AM |
3208 | static void __btf_struct_show(const struct btf *btf, const struct btf_type *t, |
3209 | u32 type_id, void *data, u8 bits_offset, | |
3210 | struct btf_show *show) | |
b00b8dae | 3211 | { |
b00b8dae | 3212 | const struct btf_member *member; |
31d0bc81 | 3213 | void *safe_data; |
b00b8dae MKL |
3214 | u32 i; |
3215 | ||
31d0bc81 AM |
3216 | safe_data = btf_show_start_struct_type(show, t, type_id, data); |
3217 | if (!safe_data) | |
3218 | return; | |
3219 | ||
b00b8dae MKL |
3220 | for_each_member(i, t, member) { |
3221 | const struct btf_type *member_type = btf_type_by_id(btf, | |
3222 | member->type); | |
b00b8dae | 3223 | const struct btf_kind_operations *ops; |
9d5f9f70 YS |
3224 | u32 member_offset, bitfield_size; |
3225 | u32 bytes_offset; | |
3226 | u8 bits8_offset; | |
b00b8dae | 3227 | |
31d0bc81 | 3228 | btf_show_start_member(show, member); |
b00b8dae | 3229 | |
8293eb99 AS |
3230 | member_offset = __btf_member_bit_offset(t, member); |
3231 | bitfield_size = __btf_member_bitfield_size(t, member); | |
17e3ac81 YS |
3232 | bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset); |
3233 | bits8_offset = BITS_PER_BYTE_MASKED(member_offset); | |
9d5f9f70 | 3234 | if (bitfield_size) { |
31d0bc81 AM |
3235 | safe_data = btf_show_start_type(show, member_type, |
3236 | member->type, | |
3237 | data + bytes_offset); | |
3238 | if (safe_data) | |
3239 | btf_bitfield_show(safe_data, | |
3240 | bits8_offset, | |
3241 | bitfield_size, show); | |
3242 | btf_show_end_type(show); | |
9d5f9f70 | 3243 | } else { |
9d5f9f70 | 3244 | ops = btf_type_ops(member_type); |
31d0bc81 AM |
3245 | ops->show(btf, member_type, member->type, |
3246 | data + bytes_offset, bits8_offset, show); | |
9d5f9f70 | 3247 | } |
31d0bc81 AM |
3248 | |
3249 | btf_show_end_member(show); | |
b00b8dae | 3250 | } |
31d0bc81 AM |
3251 | |
3252 | btf_show_end_struct_type(show); | |
3253 | } | |
3254 | ||
3255 | static void btf_struct_show(const struct btf *btf, const struct btf_type *t, | |
3256 | u32 type_id, void *data, u8 bits_offset, | |
3257 | struct btf_show *show) | |
3258 | { | |
3259 | const struct btf_member *m = show->state.member; | |
3260 | ||
3261 | /* | |
3262 | * First check if any members would be shown (are non-zero). | |
3263 | * See comments above "struct btf_show" definition for more | |
3264 | * details on how this works at a high-level. | |
3265 | */ | |
3266 | if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) { | |
3267 | if (!show->state.depth_check) { | |
3268 | show->state.depth_check = show->state.depth + 1; | |
3269 | show->state.depth_to_show = 0; | |
3270 | } | |
3271 | __btf_struct_show(btf, t, type_id, data, bits_offset, show); | |
3272 | /* Restore saved member data here */ | |
3273 | show->state.member = m; | |
3274 | if (show->state.depth_check != show->state.depth + 1) | |
3275 | return; | |
3276 | show->state.depth_check = 0; | |
3277 | ||
3278 | if (show->state.depth_to_show <= show->state.depth) | |
3279 | return; | |
3280 | /* | |
3281 | * Reaching here indicates we have recursed and found | |
3282 | * non-zero child values. | |
3283 | */ | |
3284 | } | |
3285 | ||
3286 | __btf_struct_show(btf, t, type_id, data, bits_offset, show); | |
b00b8dae MKL |
3287 | } |
3288 | ||
69b693f0 MKL |
3289 | static struct btf_kind_operations struct_ops = { |
3290 | .check_meta = btf_struct_check_meta, | |
eb3f595d | 3291 | .resolve = btf_struct_resolve, |
179cde8c | 3292 | .check_member = btf_struct_check_member, |
9d5f9f70 | 3293 | .check_kflag_member = btf_generic_check_kflag_member, |
69b693f0 | 3294 | .log_details = btf_struct_log, |
31d0bc81 | 3295 | .show = btf_struct_show, |
69b693f0 MKL |
3296 | }; |
3297 | ||
179cde8c MKL |
3298 | static int btf_enum_check_member(struct btf_verifier_env *env, |
3299 | const struct btf_type *struct_type, | |
3300 | const struct btf_member *member, | |
3301 | const struct btf_type *member_type) | |
3302 | { | |
3303 | u32 struct_bits_off = member->offset; | |
3304 | u32 struct_size, bytes_offset; | |
3305 | ||
3306 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
3307 | btf_verifier_log_member(env, struct_type, member, | |
3308 | "Member is not byte aligned"); | |
3309 | return -EINVAL; | |
3310 | } | |
3311 | ||
3312 | struct_size = struct_type->size; | |
3313 | bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); | |
da6c7fae | 3314 | if (struct_size - bytes_offset < member_type->size) { |
179cde8c MKL |
3315 | btf_verifier_log_member(env, struct_type, member, |
3316 | "Member exceeds struct_size"); | |
3317 | return -EINVAL; | |
3318 | } | |
3319 | ||
3320 | return 0; | |
3321 | } | |
3322 | ||
9d5f9f70 YS |
3323 | static int btf_enum_check_kflag_member(struct btf_verifier_env *env, |
3324 | const struct btf_type *struct_type, | |
3325 | const struct btf_member *member, | |
3326 | const struct btf_type *member_type) | |
3327 | { | |
3328 | u32 struct_bits_off, nr_bits, bytes_end, struct_size; | |
3329 | u32 int_bitsize = sizeof(int) * BITS_PER_BYTE; | |
3330 | ||
3331 | struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); | |
3332 | nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); | |
3333 | if (!nr_bits) { | |
3334 | if (BITS_PER_BYTE_MASKED(struct_bits_off)) { | |
3335 | btf_verifier_log_member(env, struct_type, member, | |
3336 | "Member is not byte aligned"); | |
e3439af4 | 3337 | return -EINVAL; |
9d5f9f70 YS |
3338 | } |
3339 | ||
3340 | nr_bits = int_bitsize; | |
3341 | } else if (nr_bits > int_bitsize) { | |
3342 | btf_verifier_log_member(env, struct_type, member, | |
3343 | "Invalid member bitfield_size"); | |
3344 | return -EINVAL; | |
3345 | } | |
3346 | ||
3347 | struct_size = struct_type->size; | |
3348 | bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits); | |
3349 | if (struct_size < bytes_end) { | |
3350 | btf_verifier_log_member(env, struct_type, member, | |
3351 | "Member exceeds struct_size"); | |
3352 | return -EINVAL; | |
3353 | } | |
3354 | ||
3355 | return 0; | |
3356 | } | |
3357 | ||
69b693f0 MKL |
3358 | static s32 btf_enum_check_meta(struct btf_verifier_env *env, |
3359 | const struct btf_type *t, | |
3360 | u32 meta_left) | |
3361 | { | |
3362 | const struct btf_enum *enums = btf_type_enum(t); | |
3363 | struct btf *btf = env->btf; | |
3364 | u16 i, nr_enums; | |
3365 | u32 meta_needed; | |
3366 | ||
3367 | nr_enums = btf_type_vlen(t); | |
3368 | meta_needed = nr_enums * sizeof(*enums); | |
3369 | ||
3370 | if (meta_left < meta_needed) { | |
3371 | btf_verifier_log_basic(env, t, | |
3372 | "meta_left:%u meta_needed:%u", | |
3373 | meta_left, meta_needed); | |
3374 | return -EINVAL; | |
3375 | } | |
3376 | ||
9d5f9f70 YS |
3377 | if (btf_type_kflag(t)) { |
3378 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
3379 | return -EINVAL; | |
3380 | } | |
3381 | ||
9eea9849 AS |
3382 | if (t->size > 8 || !is_power_of_2(t->size)) { |
3383 | btf_verifier_log_type(env, t, "Unexpected size"); | |
69b693f0 MKL |
3384 | return -EINVAL; |
3385 | } | |
3386 | ||
eb04bbb6 YS |
3387 | /* enum type either no name or a valid one */ |
3388 | if (t->name_off && | |
3389 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
3390 | btf_verifier_log_type(env, t, "Invalid name"); | |
3391 | return -EINVAL; | |
3392 | } | |
3393 | ||
69b693f0 MKL |
3394 | btf_verifier_log_type(env, t, NULL); |
3395 | ||
3396 | for (i = 0; i < nr_enums; i++) { | |
fbcf93eb | 3397 | if (!btf_name_offset_valid(btf, enums[i].name_off)) { |
69b693f0 | 3398 | btf_verifier_log(env, "\tInvalid name_offset:%u", |
fbcf93eb | 3399 | enums[i].name_off); |
69b693f0 MKL |
3400 | return -EINVAL; |
3401 | } | |
3402 | ||
eb04bbb6 YS |
3403 | /* enum member must have a valid name */ |
3404 | if (!enums[i].name_off || | |
3405 | !btf_name_valid_identifier(btf, enums[i].name_off)) { | |
3406 | btf_verifier_log_type(env, t, "Invalid name"); | |
3407 | return -EINVAL; | |
3408 | } | |
3409 | ||
8580ac94 AS |
3410 | if (env->log.level == BPF_LOG_KERNEL) |
3411 | continue; | |
69b693f0 | 3412 | btf_verifier_log(env, "\t%s val=%d\n", |
23127b33 | 3413 | __btf_name_by_offset(btf, enums[i].name_off), |
69b693f0 MKL |
3414 | enums[i].val); |
3415 | } | |
3416 | ||
3417 | return meta_needed; | |
3418 | } | |
3419 | ||
3420 | static void btf_enum_log(struct btf_verifier_env *env, | |
3421 | const struct btf_type *t) | |
3422 | { | |
3423 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
3424 | } | |
3425 | ||
31d0bc81 AM |
3426 | static void btf_enum_show(const struct btf *btf, const struct btf_type *t, |
3427 | u32 type_id, void *data, u8 bits_offset, | |
3428 | struct btf_show *show) | |
b00b8dae MKL |
3429 | { |
3430 | const struct btf_enum *enums = btf_type_enum(t); | |
3431 | u32 i, nr_enums = btf_type_vlen(t); | |
31d0bc81 AM |
3432 | void *safe_data; |
3433 | int v; | |
3434 | ||
3435 | safe_data = btf_show_start_type(show, t, type_id, data); | |
3436 | if (!safe_data) | |
3437 | return; | |
3438 | ||
3439 | v = *(int *)safe_data; | |
b00b8dae MKL |
3440 | |
3441 | for (i = 0; i < nr_enums; i++) { | |
31d0bc81 AM |
3442 | if (v != enums[i].val) |
3443 | continue; | |
3444 | ||
3445 | btf_show_type_value(show, "%s", | |
3446 | __btf_name_by_offset(btf, | |
3447 | enums[i].name_off)); | |
3448 | ||
3449 | btf_show_end_type(show); | |
3450 | return; | |
b00b8dae MKL |
3451 | } |
3452 | ||
31d0bc81 AM |
3453 | btf_show_type_value(show, "%d", v); |
3454 | btf_show_end_type(show); | |
b00b8dae MKL |
3455 | } |
3456 | ||
69b693f0 MKL |
3457 | static struct btf_kind_operations enum_ops = { |
3458 | .check_meta = btf_enum_check_meta, | |
eb3f595d | 3459 | .resolve = btf_df_resolve, |
179cde8c | 3460 | .check_member = btf_enum_check_member, |
9d5f9f70 | 3461 | .check_kflag_member = btf_enum_check_kflag_member, |
69b693f0 | 3462 | .log_details = btf_enum_log, |
31d0bc81 | 3463 | .show = btf_enum_show, |
69b693f0 MKL |
3464 | }; |
3465 | ||
2667a262 MKL |
3466 | static s32 btf_func_proto_check_meta(struct btf_verifier_env *env, |
3467 | const struct btf_type *t, | |
3468 | u32 meta_left) | |
3469 | { | |
3470 | u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param); | |
3471 | ||
3472 | if (meta_left < meta_needed) { | |
3473 | btf_verifier_log_basic(env, t, | |
3474 | "meta_left:%u meta_needed:%u", | |
3475 | meta_left, meta_needed); | |
3476 | return -EINVAL; | |
3477 | } | |
3478 | ||
3479 | if (t->name_off) { | |
3480 | btf_verifier_log_type(env, t, "Invalid name"); | |
3481 | return -EINVAL; | |
3482 | } | |
3483 | ||
9d5f9f70 YS |
3484 | if (btf_type_kflag(t)) { |
3485 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
3486 | return -EINVAL; | |
3487 | } | |
3488 | ||
2667a262 MKL |
3489 | btf_verifier_log_type(env, t, NULL); |
3490 | ||
3491 | return meta_needed; | |
3492 | } | |
3493 | ||
3494 | static void btf_func_proto_log(struct btf_verifier_env *env, | |
3495 | const struct btf_type *t) | |
3496 | { | |
3497 | const struct btf_param *args = (const struct btf_param *)(t + 1); | |
3498 | u16 nr_args = btf_type_vlen(t), i; | |
3499 | ||
3500 | btf_verifier_log(env, "return=%u args=(", t->type); | |
3501 | if (!nr_args) { | |
3502 | btf_verifier_log(env, "void"); | |
3503 | goto done; | |
3504 | } | |
3505 | ||
3506 | if (nr_args == 1 && !args[0].type) { | |
3507 | /* Only one vararg */ | |
3508 | btf_verifier_log(env, "vararg"); | |
3509 | goto done; | |
3510 | } | |
3511 | ||
3512 | btf_verifier_log(env, "%u %s", args[0].type, | |
23127b33 MKL |
3513 | __btf_name_by_offset(env->btf, |
3514 | args[0].name_off)); | |
2667a262 MKL |
3515 | for (i = 1; i < nr_args - 1; i++) |
3516 | btf_verifier_log(env, ", %u %s", args[i].type, | |
23127b33 MKL |
3517 | __btf_name_by_offset(env->btf, |
3518 | args[i].name_off)); | |
2667a262 MKL |
3519 | |
3520 | if (nr_args > 1) { | |
3521 | const struct btf_param *last_arg = &args[nr_args - 1]; | |
3522 | ||
3523 | if (last_arg->type) | |
3524 | btf_verifier_log(env, ", %u %s", last_arg->type, | |
23127b33 MKL |
3525 | __btf_name_by_offset(env->btf, |
3526 | last_arg->name_off)); | |
2667a262 MKL |
3527 | else |
3528 | btf_verifier_log(env, ", vararg"); | |
3529 | } | |
3530 | ||
3531 | done: | |
3532 | btf_verifier_log(env, ")"); | |
3533 | } | |
3534 | ||
3535 | static struct btf_kind_operations func_proto_ops = { | |
3536 | .check_meta = btf_func_proto_check_meta, | |
3537 | .resolve = btf_df_resolve, | |
3538 | /* | |
3539 | * BTF_KIND_FUNC_PROTO cannot be directly referred by | |
3540 | * a struct's member. | |
3541 | * | |
8fb33b60 | 3542 | * It should be a function pointer instead. |
2667a262 MKL |
3543 | * (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO) |
3544 | * | |
3545 | * Hence, there is no btf_func_check_member(). | |
3546 | */ | |
3547 | .check_member = btf_df_check_member, | |
9d5f9f70 | 3548 | .check_kflag_member = btf_df_check_kflag_member, |
2667a262 | 3549 | .log_details = btf_func_proto_log, |
31d0bc81 | 3550 | .show = btf_df_show, |
2667a262 MKL |
3551 | }; |
3552 | ||
3553 | static s32 btf_func_check_meta(struct btf_verifier_env *env, | |
3554 | const struct btf_type *t, | |
3555 | u32 meta_left) | |
3556 | { | |
3557 | if (!t->name_off || | |
3558 | !btf_name_valid_identifier(env->btf, t->name_off)) { | |
3559 | btf_verifier_log_type(env, t, "Invalid name"); | |
3560 | return -EINVAL; | |
3561 | } | |
3562 | ||
51c39bb1 AS |
3563 | if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) { |
3564 | btf_verifier_log_type(env, t, "Invalid func linkage"); | |
2667a262 MKL |
3565 | return -EINVAL; |
3566 | } | |
3567 | ||
9d5f9f70 YS |
3568 | if (btf_type_kflag(t)) { |
3569 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
3570 | return -EINVAL; | |
3571 | } | |
3572 | ||
2667a262 MKL |
3573 | btf_verifier_log_type(env, t, NULL); |
3574 | ||
3575 | return 0; | |
3576 | } | |
3577 | ||
d7e7b42f YS |
3578 | static int btf_func_resolve(struct btf_verifier_env *env, |
3579 | const struct resolve_vertex *v) | |
3580 | { | |
3581 | const struct btf_type *t = v->t; | |
3582 | u32 next_type_id = t->type; | |
3583 | int err; | |
3584 | ||
3585 | err = btf_func_check(env, t); | |
3586 | if (err) | |
3587 | return err; | |
3588 | ||
3589 | env_stack_pop_resolved(env, next_type_id, 0); | |
3590 | return 0; | |
3591 | } | |
3592 | ||
2667a262 MKL |
3593 | static struct btf_kind_operations func_ops = { |
3594 | .check_meta = btf_func_check_meta, | |
d7e7b42f | 3595 | .resolve = btf_func_resolve, |
2667a262 | 3596 | .check_member = btf_df_check_member, |
9d5f9f70 | 3597 | .check_kflag_member = btf_df_check_kflag_member, |
2667a262 | 3598 | .log_details = btf_ref_type_log, |
31d0bc81 | 3599 | .show = btf_df_show, |
2667a262 MKL |
3600 | }; |
3601 | ||
1dc92851 DB |
3602 | static s32 btf_var_check_meta(struct btf_verifier_env *env, |
3603 | const struct btf_type *t, | |
3604 | u32 meta_left) | |
3605 | { | |
3606 | const struct btf_var *var; | |
3607 | u32 meta_needed = sizeof(*var); | |
3608 | ||
3609 | if (meta_left < meta_needed) { | |
3610 | btf_verifier_log_basic(env, t, | |
3611 | "meta_left:%u meta_needed:%u", | |
3612 | meta_left, meta_needed); | |
3613 | return -EINVAL; | |
3614 | } | |
3615 | ||
3616 | if (btf_type_vlen(t)) { | |
3617 | btf_verifier_log_type(env, t, "vlen != 0"); | |
3618 | return -EINVAL; | |
3619 | } | |
3620 | ||
3621 | if (btf_type_kflag(t)) { | |
3622 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
3623 | return -EINVAL; | |
3624 | } | |
3625 | ||
3626 | if (!t->name_off || | |
3627 | !__btf_name_valid(env->btf, t->name_off, true)) { | |
3628 | btf_verifier_log_type(env, t, "Invalid name"); | |
3629 | return -EINVAL; | |
3630 | } | |
3631 | ||
3632 | /* A var cannot be in type void */ | |
3633 | if (!t->type || !BTF_TYPE_ID_VALID(t->type)) { | |
3634 | btf_verifier_log_type(env, t, "Invalid type_id"); | |
3635 | return -EINVAL; | |
3636 | } | |
3637 | ||
3638 | var = btf_type_var(t); | |
3639 | if (var->linkage != BTF_VAR_STATIC && | |
3640 | var->linkage != BTF_VAR_GLOBAL_ALLOCATED) { | |
3641 | btf_verifier_log_type(env, t, "Linkage not supported"); | |
3642 | return -EINVAL; | |
3643 | } | |
3644 | ||
3645 | btf_verifier_log_type(env, t, NULL); | |
3646 | ||
3647 | return meta_needed; | |
3648 | } | |
3649 | ||
3650 | static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t) | |
3651 | { | |
3652 | const struct btf_var *var = btf_type_var(t); | |
3653 | ||
3654 | btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage); | |
3655 | } | |
3656 | ||
3657 | static const struct btf_kind_operations var_ops = { | |
3658 | .check_meta = btf_var_check_meta, | |
3659 | .resolve = btf_var_resolve, | |
3660 | .check_member = btf_df_check_member, | |
3661 | .check_kflag_member = btf_df_check_kflag_member, | |
3662 | .log_details = btf_var_log, | |
31d0bc81 | 3663 | .show = btf_var_show, |
1dc92851 DB |
3664 | }; |
3665 | ||
3666 | static s32 btf_datasec_check_meta(struct btf_verifier_env *env, | |
3667 | const struct btf_type *t, | |
3668 | u32 meta_left) | |
3669 | { | |
3670 | const struct btf_var_secinfo *vsi; | |
3671 | u64 last_vsi_end_off = 0, sum = 0; | |
3672 | u32 i, meta_needed; | |
3673 | ||
3674 | meta_needed = btf_type_vlen(t) * sizeof(*vsi); | |
3675 | if (meta_left < meta_needed) { | |
3676 | btf_verifier_log_basic(env, t, | |
3677 | "meta_left:%u meta_needed:%u", | |
3678 | meta_left, meta_needed); | |
3679 | return -EINVAL; | |
3680 | } | |
3681 | ||
1dc92851 DB |
3682 | if (!t->size) { |
3683 | btf_verifier_log_type(env, t, "size == 0"); | |
3684 | return -EINVAL; | |
3685 | } | |
3686 | ||
3687 | if (btf_type_kflag(t)) { | |
3688 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
3689 | return -EINVAL; | |
3690 | } | |
3691 | ||
3692 | if (!t->name_off || | |
3693 | !btf_name_valid_section(env->btf, t->name_off)) { | |
3694 | btf_verifier_log_type(env, t, "Invalid name"); | |
3695 | return -EINVAL; | |
3696 | } | |
3697 | ||
3698 | btf_verifier_log_type(env, t, NULL); | |
3699 | ||
3700 | for_each_vsi(i, t, vsi) { | |
3701 | /* A var cannot be in type void */ | |
3702 | if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) { | |
3703 | btf_verifier_log_vsi(env, t, vsi, | |
3704 | "Invalid type_id"); | |
3705 | return -EINVAL; | |
3706 | } | |
3707 | ||
3708 | if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) { | |
3709 | btf_verifier_log_vsi(env, t, vsi, | |
3710 | "Invalid offset"); | |
3711 | return -EINVAL; | |
3712 | } | |
3713 | ||
3714 | if (!vsi->size || vsi->size > t->size) { | |
3715 | btf_verifier_log_vsi(env, t, vsi, | |
3716 | "Invalid size"); | |
3717 | return -EINVAL; | |
3718 | } | |
3719 | ||
3720 | last_vsi_end_off = vsi->offset + vsi->size; | |
3721 | if (last_vsi_end_off > t->size) { | |
3722 | btf_verifier_log_vsi(env, t, vsi, | |
3723 | "Invalid offset+size"); | |
3724 | return -EINVAL; | |
3725 | } | |
3726 | ||
3727 | btf_verifier_log_vsi(env, t, vsi, NULL); | |
3728 | sum += vsi->size; | |
3729 | } | |
3730 | ||
3731 | if (t->size < sum) { | |
3732 | btf_verifier_log_type(env, t, "Invalid btf_info size"); | |
3733 | return -EINVAL; | |
3734 | } | |
3735 | ||
3736 | return meta_needed; | |
3737 | } | |
3738 | ||
3739 | static int btf_datasec_resolve(struct btf_verifier_env *env, | |
3740 | const struct resolve_vertex *v) | |
3741 | { | |
3742 | const struct btf_var_secinfo *vsi; | |
3743 | struct btf *btf = env->btf; | |
3744 | u16 i; | |
3745 | ||
3746 | for_each_vsi_from(i, v->next_member, v->t, vsi) { | |
3747 | u32 var_type_id = vsi->type, type_id, type_size = 0; | |
3748 | const struct btf_type *var_type = btf_type_by_id(env->btf, | |
3749 | var_type_id); | |
3750 | if (!var_type || !btf_type_is_var(var_type)) { | |
3751 | btf_verifier_log_vsi(env, v->t, vsi, | |
3752 | "Not a VAR kind member"); | |
3753 | return -EINVAL; | |
3754 | } | |
3755 | ||
3756 | if (!env_type_is_resolve_sink(env, var_type) && | |
3757 | !env_type_is_resolved(env, var_type_id)) { | |
3758 | env_stack_set_next_member(env, i + 1); | |
3759 | return env_stack_push(env, var_type, var_type_id); | |
3760 | } | |
3761 | ||
3762 | type_id = var_type->type; | |
3763 | if (!btf_type_id_size(btf, &type_id, &type_size)) { | |
3764 | btf_verifier_log_vsi(env, v->t, vsi, "Invalid type"); | |
3765 | return -EINVAL; | |
3766 | } | |
3767 | ||
3768 | if (vsi->size < type_size) { | |
3769 | btf_verifier_log_vsi(env, v->t, vsi, "Invalid size"); | |
3770 | return -EINVAL; | |
3771 | } | |
3772 | } | |
3773 | ||
3774 | env_stack_pop_resolved(env, 0, 0); | |
3775 | return 0; | |
3776 | } | |
3777 | ||
3778 | static void btf_datasec_log(struct btf_verifier_env *env, | |
3779 | const struct btf_type *t) | |
3780 | { | |
3781 | btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); | |
3782 | } | |
3783 | ||
31d0bc81 AM |
3784 | static void btf_datasec_show(const struct btf *btf, |
3785 | const struct btf_type *t, u32 type_id, | |
3786 | void *data, u8 bits_offset, | |
3787 | struct btf_show *show) | |
1dc92851 DB |
3788 | { |
3789 | const struct btf_var_secinfo *vsi; | |
3790 | const struct btf_type *var; | |
3791 | u32 i; | |
3792 | ||
31d0bc81 AM |
3793 | if (!btf_show_start_type(show, t, type_id, data)) |
3794 | return; | |
3795 | ||
3796 | btf_show_type_value(show, "section (\"%s\") = {", | |
3797 | __btf_name_by_offset(btf, t->name_off)); | |
1dc92851 DB |
3798 | for_each_vsi(i, t, vsi) { |
3799 | var = btf_type_by_id(btf, vsi->type); | |
3800 | if (i) | |
31d0bc81 AM |
3801 | btf_show(show, ","); |
3802 | btf_type_ops(var)->show(btf, var, vsi->type, | |
3803 | data + vsi->offset, bits_offset, show); | |
1dc92851 | 3804 | } |
31d0bc81 | 3805 | btf_show_end_type(show); |
1dc92851 DB |
3806 | } |
3807 | ||
3808 | static const struct btf_kind_operations datasec_ops = { | |
3809 | .check_meta = btf_datasec_check_meta, | |
3810 | .resolve = btf_datasec_resolve, | |
3811 | .check_member = btf_df_check_member, | |
3812 | .check_kflag_member = btf_df_check_kflag_member, | |
3813 | .log_details = btf_datasec_log, | |
31d0bc81 | 3814 | .show = btf_datasec_show, |
1dc92851 DB |
3815 | }; |
3816 | ||
b1828f0b IL |
3817 | static s32 btf_float_check_meta(struct btf_verifier_env *env, |
3818 | const struct btf_type *t, | |
3819 | u32 meta_left) | |
3820 | { | |
3821 | if (btf_type_vlen(t)) { | |
3822 | btf_verifier_log_type(env, t, "vlen != 0"); | |
3823 | return -EINVAL; | |
3824 | } | |
3825 | ||
3826 | if (btf_type_kflag(t)) { | |
3827 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
3828 | return -EINVAL; | |
3829 | } | |
3830 | ||
3831 | if (t->size != 2 && t->size != 4 && t->size != 8 && t->size != 12 && | |
3832 | t->size != 16) { | |
3833 | btf_verifier_log_type(env, t, "Invalid type_size"); | |
3834 | return -EINVAL; | |
3835 | } | |
3836 | ||
3837 | btf_verifier_log_type(env, t, NULL); | |
3838 | ||
3839 | return 0; | |
3840 | } | |
3841 | ||
3842 | static int btf_float_check_member(struct btf_verifier_env *env, | |
3843 | const struct btf_type *struct_type, | |
3844 | const struct btf_member *member, | |
3845 | const struct btf_type *member_type) | |
3846 | { | |
3847 | u64 start_offset_bytes; | |
3848 | u64 end_offset_bytes; | |
3849 | u64 misalign_bits; | |
3850 | u64 align_bytes; | |
3851 | u64 align_bits; | |
3852 | ||
3853 | /* Different architectures have different alignment requirements, so | |
3854 | * here we check only for the reasonable minimum. This way we ensure | |
3855 | * that types after CO-RE can pass the kernel BTF verifier. | |
3856 | */ | |
3857 | align_bytes = min_t(u64, sizeof(void *), member_type->size); | |
3858 | align_bits = align_bytes * BITS_PER_BYTE; | |
3859 | div64_u64_rem(member->offset, align_bits, &misalign_bits); | |
3860 | if (misalign_bits) { | |
3861 | btf_verifier_log_member(env, struct_type, member, | |
3862 | "Member is not properly aligned"); | |
3863 | return -EINVAL; | |
3864 | } | |
3865 | ||
3866 | start_offset_bytes = member->offset / BITS_PER_BYTE; | |
3867 | end_offset_bytes = start_offset_bytes + member_type->size; | |
3868 | if (end_offset_bytes > struct_type->size) { | |
3869 | btf_verifier_log_member(env, struct_type, member, | |
3870 | "Member exceeds struct_size"); | |
3871 | return -EINVAL; | |
3872 | } | |
3873 | ||
3874 | return 0; | |
3875 | } | |
3876 | ||
3877 | static void btf_float_log(struct btf_verifier_env *env, | |
3878 | const struct btf_type *t) | |
3879 | { | |
3880 | btf_verifier_log(env, "size=%u", t->size); | |
3881 | } | |
3882 | ||
3883 | static const struct btf_kind_operations float_ops = { | |
3884 | .check_meta = btf_float_check_meta, | |
3885 | .resolve = btf_df_resolve, | |
3886 | .check_member = btf_float_check_member, | |
3887 | .check_kflag_member = btf_generic_check_kflag_member, | |
3888 | .log_details = btf_float_log, | |
3889 | .show = btf_df_show, | |
3890 | }; | |
3891 | ||
223f903e | 3892 | static s32 btf_decl_tag_check_meta(struct btf_verifier_env *env, |
b5ea834d YS |
3893 | const struct btf_type *t, |
3894 | u32 meta_left) | |
3895 | { | |
223f903e | 3896 | const struct btf_decl_tag *tag; |
b5ea834d YS |
3897 | u32 meta_needed = sizeof(*tag); |
3898 | s32 component_idx; | |
3899 | const char *value; | |
3900 | ||
3901 | if (meta_left < meta_needed) { | |
3902 | btf_verifier_log_basic(env, t, | |
3903 | "meta_left:%u meta_needed:%u", | |
3904 | meta_left, meta_needed); | |
3905 | return -EINVAL; | |
3906 | } | |
3907 | ||
3908 | value = btf_name_by_offset(env->btf, t->name_off); | |
3909 | if (!value || !value[0]) { | |
3910 | btf_verifier_log_type(env, t, "Invalid value"); | |
3911 | return -EINVAL; | |
3912 | } | |
3913 | ||
3914 | if (btf_type_vlen(t)) { | |
3915 | btf_verifier_log_type(env, t, "vlen != 0"); | |
3916 | return -EINVAL; | |
3917 | } | |
3918 | ||
3919 | if (btf_type_kflag(t)) { | |
3920 | btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); | |
3921 | return -EINVAL; | |
3922 | } | |
3923 | ||
223f903e | 3924 | component_idx = btf_type_decl_tag(t)->component_idx; |
b5ea834d YS |
3925 | if (component_idx < -1) { |
3926 | btf_verifier_log_type(env, t, "Invalid component_idx"); | |
3927 | return -EINVAL; | |
3928 | } | |
3929 | ||
3930 | btf_verifier_log_type(env, t, NULL); | |
3931 | ||
3932 | return meta_needed; | |
3933 | } | |
3934 | ||
223f903e | 3935 | static int btf_decl_tag_resolve(struct btf_verifier_env *env, |
b5ea834d YS |
3936 | const struct resolve_vertex *v) |
3937 | { | |
3938 | const struct btf_type *next_type; | |
3939 | const struct btf_type *t = v->t; | |
3940 | u32 next_type_id = t->type; | |
3941 | struct btf *btf = env->btf; | |
3942 | s32 component_idx; | |
3943 | u32 vlen; | |
3944 | ||
3945 | next_type = btf_type_by_id(btf, next_type_id); | |
223f903e | 3946 | if (!next_type || !btf_type_is_decl_tag_target(next_type)) { |
b5ea834d YS |
3947 | btf_verifier_log_type(env, v->t, "Invalid type_id"); |
3948 | return -EINVAL; | |
3949 | } | |
3950 | ||
3951 | if (!env_type_is_resolve_sink(env, next_type) && | |
3952 | !env_type_is_resolved(env, next_type_id)) | |
3953 | return env_stack_push(env, next_type, next_type_id); | |
3954 | ||
223f903e | 3955 | component_idx = btf_type_decl_tag(t)->component_idx; |
b5ea834d | 3956 | if (component_idx != -1) { |
bd16dee6 | 3957 | if (btf_type_is_var(next_type) || btf_type_is_typedef(next_type)) { |
b5ea834d YS |
3958 | btf_verifier_log_type(env, v->t, "Invalid component_idx"); |
3959 | return -EINVAL; | |
3960 | } | |
3961 | ||
3962 | if (btf_type_is_struct(next_type)) { | |
3963 | vlen = btf_type_vlen(next_type); | |
3964 | } else { | |
3965 | /* next_type should be a function */ | |
3966 | next_type = btf_type_by_id(btf, next_type->type); | |
3967 | vlen = btf_type_vlen(next_type); | |
3968 | } | |
3969 | ||
3970 | if ((u32)component_idx >= vlen) { | |
3971 | btf_verifier_log_type(env, v->t, "Invalid component_idx"); | |
3972 | return -EINVAL; | |
3973 | } | |
3974 | } | |
3975 | ||
3976 | env_stack_pop_resolved(env, next_type_id, 0); | |
3977 | ||
3978 | return 0; | |
3979 | } | |
3980 | ||
223f903e | 3981 | static void btf_decl_tag_log(struct btf_verifier_env *env, const struct btf_type *t) |
b5ea834d YS |
3982 | { |
3983 | btf_verifier_log(env, "type=%u component_idx=%d", t->type, | |
223f903e | 3984 | btf_type_decl_tag(t)->component_idx); |
b5ea834d YS |
3985 | } |
3986 | ||
223f903e YS |
3987 | static const struct btf_kind_operations decl_tag_ops = { |
3988 | .check_meta = btf_decl_tag_check_meta, | |
3989 | .resolve = btf_decl_tag_resolve, | |
b5ea834d YS |
3990 | .check_member = btf_df_check_member, |
3991 | .check_kflag_member = btf_df_check_kflag_member, | |
223f903e | 3992 | .log_details = btf_decl_tag_log, |
b5ea834d YS |
3993 | .show = btf_df_show, |
3994 | }; | |
3995 | ||
2667a262 MKL |
3996 | static int btf_func_proto_check(struct btf_verifier_env *env, |
3997 | const struct btf_type *t) | |
3998 | { | |
3999 | const struct btf_type *ret_type; | |
4000 | const struct btf_param *args; | |
4001 | const struct btf *btf; | |
4002 | u16 nr_args, i; | |
4003 | int err; | |
4004 | ||
4005 | btf = env->btf; | |
4006 | args = (const struct btf_param *)(t + 1); | |
4007 | nr_args = btf_type_vlen(t); | |
4008 | ||
4009 | /* Check func return type which could be "void" (t->type == 0) */ | |
4010 | if (t->type) { | |
4011 | u32 ret_type_id = t->type; | |
4012 | ||
4013 | ret_type = btf_type_by_id(btf, ret_type_id); | |
4014 | if (!ret_type) { | |
4015 | btf_verifier_log_type(env, t, "Invalid return type"); | |
4016 | return -EINVAL; | |
4017 | } | |
4018 | ||
4019 | if (btf_type_needs_resolve(ret_type) && | |
4020 | !env_type_is_resolved(env, ret_type_id)) { | |
4021 | err = btf_resolve(env, ret_type, ret_type_id); | |
4022 | if (err) | |
4023 | return err; | |
4024 | } | |
4025 | ||
4026 | /* Ensure the return type is a type that has a size */ | |
4027 | if (!btf_type_id_size(btf, &ret_type_id, NULL)) { | |
4028 | btf_verifier_log_type(env, t, "Invalid return type"); | |
4029 | return -EINVAL; | |
4030 | } | |
4031 | } | |
4032 | ||
4033 | if (!nr_args) | |
4034 | return 0; | |
4035 | ||
4036 | /* Last func arg type_id could be 0 if it is a vararg */ | |
4037 | if (!args[nr_args - 1].type) { | |
4038 | if (args[nr_args - 1].name_off) { | |
4039 | btf_verifier_log_type(env, t, "Invalid arg#%u", | |
4040 | nr_args); | |
4041 | return -EINVAL; | |
4042 | } | |
4043 | nr_args--; | |
4044 | } | |
4045 | ||
4046 | err = 0; | |
4047 | for (i = 0; i < nr_args; i++) { | |
4048 | const struct btf_type *arg_type; | |
4049 | u32 arg_type_id; | |
4050 | ||
4051 | arg_type_id = args[i].type; | |
4052 | arg_type = btf_type_by_id(btf, arg_type_id); | |
4053 | if (!arg_type) { | |
4054 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
4055 | err = -EINVAL; | |
4056 | break; | |
4057 | } | |
4058 | ||
4059 | if (args[i].name_off && | |
4060 | (!btf_name_offset_valid(btf, args[i].name_off) || | |
4061 | !btf_name_valid_identifier(btf, args[i].name_off))) { | |
4062 | btf_verifier_log_type(env, t, | |
4063 | "Invalid arg#%u", i + 1); | |
4064 | err = -EINVAL; | |
4065 | break; | |
4066 | } | |
4067 | ||
4068 | if (btf_type_needs_resolve(arg_type) && | |
4069 | !env_type_is_resolved(env, arg_type_id)) { | |
4070 | err = btf_resolve(env, arg_type, arg_type_id); | |
4071 | if (err) | |
4072 | break; | |
4073 | } | |
4074 | ||
4075 | if (!btf_type_id_size(btf, &arg_type_id, NULL)) { | |
4076 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
4077 | err = -EINVAL; | |
4078 | break; | |
4079 | } | |
4080 | } | |
4081 | ||
4082 | return err; | |
4083 | } | |
4084 | ||
4085 | static int btf_func_check(struct btf_verifier_env *env, | |
4086 | const struct btf_type *t) | |
4087 | { | |
4088 | const struct btf_type *proto_type; | |
4089 | const struct btf_param *args; | |
4090 | const struct btf *btf; | |
4091 | u16 nr_args, i; | |
4092 | ||
4093 | btf = env->btf; | |
4094 | proto_type = btf_type_by_id(btf, t->type); | |
4095 | ||
4096 | if (!proto_type || !btf_type_is_func_proto(proto_type)) { | |
4097 | btf_verifier_log_type(env, t, "Invalid type_id"); | |
4098 | return -EINVAL; | |
4099 | } | |
4100 | ||
4101 | args = (const struct btf_param *)(proto_type + 1); | |
4102 | nr_args = btf_type_vlen(proto_type); | |
4103 | for (i = 0; i < nr_args; i++) { | |
4104 | if (!args[i].name_off && args[i].type) { | |
4105 | btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); | |
4106 | return -EINVAL; | |
4107 | } | |
4108 | } | |
4109 | ||
4110 | return 0; | |
4111 | } | |
4112 | ||
69b693f0 MKL |
4113 | static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = { |
4114 | [BTF_KIND_INT] = &int_ops, | |
4115 | [BTF_KIND_PTR] = &ptr_ops, | |
4116 | [BTF_KIND_ARRAY] = &array_ops, | |
4117 | [BTF_KIND_STRUCT] = &struct_ops, | |
4118 | [BTF_KIND_UNION] = &struct_ops, | |
4119 | [BTF_KIND_ENUM] = &enum_ops, | |
4120 | [BTF_KIND_FWD] = &fwd_ops, | |
4121 | [BTF_KIND_TYPEDEF] = &modifier_ops, | |
4122 | [BTF_KIND_VOLATILE] = &modifier_ops, | |
4123 | [BTF_KIND_CONST] = &modifier_ops, | |
4124 | [BTF_KIND_RESTRICT] = &modifier_ops, | |
2667a262 MKL |
4125 | [BTF_KIND_FUNC] = &func_ops, |
4126 | [BTF_KIND_FUNC_PROTO] = &func_proto_ops, | |
1dc92851 DB |
4127 | [BTF_KIND_VAR] = &var_ops, |
4128 | [BTF_KIND_DATASEC] = &datasec_ops, | |
b1828f0b | 4129 | [BTF_KIND_FLOAT] = &float_ops, |
223f903e | 4130 | [BTF_KIND_DECL_TAG] = &decl_tag_ops, |
8c42d2fa | 4131 | [BTF_KIND_TYPE_TAG] = &modifier_ops, |
69b693f0 MKL |
4132 | }; |
4133 | ||
4134 | static s32 btf_check_meta(struct btf_verifier_env *env, | |
4135 | const struct btf_type *t, | |
4136 | u32 meta_left) | |
4137 | { | |
4138 | u32 saved_meta_left = meta_left; | |
4139 | s32 var_meta_size; | |
4140 | ||
4141 | if (meta_left < sizeof(*t)) { | |
4142 | btf_verifier_log(env, "[%u] meta_left:%u meta_needed:%zu", | |
4143 | env->log_type_id, meta_left, sizeof(*t)); | |
4144 | return -EINVAL; | |
4145 | } | |
4146 | meta_left -= sizeof(*t); | |
4147 | ||
aea2f7b8 MKL |
4148 | if (t->info & ~BTF_INFO_MASK) { |
4149 | btf_verifier_log(env, "[%u] Invalid btf_info:%x", | |
4150 | env->log_type_id, t->info); | |
4151 | return -EINVAL; | |
4152 | } | |
4153 | ||
69b693f0 MKL |
4154 | if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX || |
4155 | BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) { | |
4156 | btf_verifier_log(env, "[%u] Invalid kind:%u", | |
4157 | env->log_type_id, BTF_INFO_KIND(t->info)); | |
4158 | return -EINVAL; | |
4159 | } | |
4160 | ||
fbcf93eb | 4161 | if (!btf_name_offset_valid(env->btf, t->name_off)) { |
69b693f0 | 4162 | btf_verifier_log(env, "[%u] Invalid name_offset:%u", |
fbcf93eb | 4163 | env->log_type_id, t->name_off); |
69b693f0 MKL |
4164 | return -EINVAL; |
4165 | } | |
4166 | ||
4167 | var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left); | |
4168 | if (var_meta_size < 0) | |
4169 | return var_meta_size; | |
4170 | ||
4171 | meta_left -= var_meta_size; | |
4172 | ||
4173 | return saved_meta_left - meta_left; | |
4174 | } | |
4175 | ||
4176 | static int btf_check_all_metas(struct btf_verifier_env *env) | |
4177 | { | |
4178 | struct btf *btf = env->btf; | |
4179 | struct btf_header *hdr; | |
4180 | void *cur, *end; | |
4181 | ||
f80442a4 | 4182 | hdr = &btf->hdr; |
69b693f0 | 4183 | cur = btf->nohdr_data + hdr->type_off; |
4b1c5d91 | 4184 | end = cur + hdr->type_len; |
69b693f0 | 4185 | |
951bb646 | 4186 | env->log_type_id = btf->base_btf ? btf->start_id : 1; |
69b693f0 MKL |
4187 | while (cur < end) { |
4188 | struct btf_type *t = cur; | |
4189 | s32 meta_size; | |
4190 | ||
4191 | meta_size = btf_check_meta(env, t, end - cur); | |
4192 | if (meta_size < 0) | |
4193 | return meta_size; | |
4194 | ||
4195 | btf_add_type(env, t); | |
4196 | cur += meta_size; | |
4197 | env->log_type_id++; | |
4198 | } | |
4199 | ||
4200 | return 0; | |
4201 | } | |
4202 | ||
eb3f595d MKL |
4203 | static bool btf_resolve_valid(struct btf_verifier_env *env, |
4204 | const struct btf_type *t, | |
4205 | u32 type_id) | |
4206 | { | |
4207 | struct btf *btf = env->btf; | |
4208 | ||
4209 | if (!env_type_is_resolved(env, type_id)) | |
4210 | return false; | |
4211 | ||
1dc92851 | 4212 | if (btf_type_is_struct(t) || btf_type_is_datasec(t)) |
951bb646 AN |
4213 | return !btf_resolved_type_id(btf, type_id) && |
4214 | !btf_resolved_type_size(btf, type_id); | |
eb3f595d | 4215 | |
d7e7b42f | 4216 | if (btf_type_is_decl_tag(t) || btf_type_is_func(t)) |
b5ea834d YS |
4217 | return btf_resolved_type_id(btf, type_id) && |
4218 | !btf_resolved_type_size(btf, type_id); | |
4219 | ||
1dc92851 DB |
4220 | if (btf_type_is_modifier(t) || btf_type_is_ptr(t) || |
4221 | btf_type_is_var(t)) { | |
eb3f595d | 4222 | t = btf_type_id_resolve(btf, &type_id); |
1dc92851 DB |
4223 | return t && |
4224 | !btf_type_is_modifier(t) && | |
4225 | !btf_type_is_var(t) && | |
4226 | !btf_type_is_datasec(t); | |
eb3f595d MKL |
4227 | } |
4228 | ||
4229 | if (btf_type_is_array(t)) { | |
4230 | const struct btf_array *array = btf_type_array(t); | |
4231 | const struct btf_type *elem_type; | |
4232 | u32 elem_type_id = array->type; | |
4233 | u32 elem_size; | |
4234 | ||
4235 | elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); | |
4236 | return elem_type && !btf_type_is_modifier(elem_type) && | |
4237 | (array->nelems * elem_size == | |
951bb646 | 4238 | btf_resolved_type_size(btf, type_id)); |
eb3f595d MKL |
4239 | } |
4240 | ||
4241 | return false; | |
4242 | } | |
4243 | ||
2667a262 MKL |
4244 | static int btf_resolve(struct btf_verifier_env *env, |
4245 | const struct btf_type *t, u32 type_id) | |
4246 | { | |
4247 | u32 save_log_type_id = env->log_type_id; | |
4248 | const struct resolve_vertex *v; | |
4249 | int err = 0; | |
4250 | ||
4251 | env->resolve_mode = RESOLVE_TBD; | |
4252 | env_stack_push(env, t, type_id); | |
4253 | while (!err && (v = env_stack_peak(env))) { | |
4254 | env->log_type_id = v->type_id; | |
4255 | err = btf_type_ops(v->t)->resolve(env, v); | |
4256 | } | |
4257 | ||
4258 | env->log_type_id = type_id; | |
4259 | if (err == -E2BIG) { | |
4260 | btf_verifier_log_type(env, t, | |
4261 | "Exceeded max resolving depth:%u", | |
4262 | MAX_RESOLVE_DEPTH); | |
4263 | } else if (err == -EEXIST) { | |
4264 | btf_verifier_log_type(env, t, "Loop detected"); | |
4265 | } | |
4266 | ||
4267 | /* Final sanity check */ | |
4268 | if (!err && !btf_resolve_valid(env, t, type_id)) { | |
4269 | btf_verifier_log_type(env, t, "Invalid resolve state"); | |
4270 | err = -EINVAL; | |
4271 | } | |
4272 | ||
4273 | env->log_type_id = save_log_type_id; | |
4274 | return err; | |
4275 | } | |
4276 | ||
eb3f595d MKL |
4277 | static int btf_check_all_types(struct btf_verifier_env *env) |
4278 | { | |
4279 | struct btf *btf = env->btf; | |
951bb646 AN |
4280 | const struct btf_type *t; |
4281 | u32 type_id, i; | |
eb3f595d MKL |
4282 | int err; |
4283 | ||
4284 | err = env_resolve_init(env); | |
4285 | if (err) | |
4286 | return err; | |
4287 | ||
4288 | env->phase++; | |
951bb646 AN |
4289 | for (i = btf->base_btf ? 0 : 1; i < btf->nr_types; i++) { |
4290 | type_id = btf->start_id + i; | |
4291 | t = btf_type_by_id(btf, type_id); | |
eb3f595d MKL |
4292 | |
4293 | env->log_type_id = type_id; | |
4294 | if (btf_type_needs_resolve(t) && | |
4295 | !env_type_is_resolved(env, type_id)) { | |
4296 | err = btf_resolve(env, t, type_id); | |
4297 | if (err) | |
4298 | return err; | |
4299 | } | |
4300 | ||
2667a262 MKL |
4301 | if (btf_type_is_func_proto(t)) { |
4302 | err = btf_func_proto_check(env, t); | |
4303 | if (err) | |
4304 | return err; | |
4305 | } | |
eb3f595d MKL |
4306 | } |
4307 | ||
4308 | return 0; | |
4309 | } | |
4310 | ||
69b693f0 MKL |
4311 | static int btf_parse_type_sec(struct btf_verifier_env *env) |
4312 | { | |
f80442a4 | 4313 | const struct btf_header *hdr = &env->btf->hdr; |
eb3f595d MKL |
4314 | int err; |
4315 | ||
f80442a4 MKL |
4316 | /* Type section must align to 4 bytes */ |
4317 | if (hdr->type_off & (sizeof(u32) - 1)) { | |
4318 | btf_verifier_log(env, "Unaligned type_off"); | |
4319 | return -EINVAL; | |
4320 | } | |
4321 | ||
951bb646 | 4322 | if (!env->btf->base_btf && !hdr->type_len) { |
f80442a4 MKL |
4323 | btf_verifier_log(env, "No type found"); |
4324 | return -EINVAL; | |
4325 | } | |
4326 | ||
eb3f595d MKL |
4327 | err = btf_check_all_metas(env); |
4328 | if (err) | |
4329 | return err; | |
4330 | ||
4331 | return btf_check_all_types(env); | |
69b693f0 MKL |
4332 | } |
4333 | ||
4334 | static int btf_parse_str_sec(struct btf_verifier_env *env) | |
4335 | { | |
4336 | const struct btf_header *hdr; | |
4337 | struct btf *btf = env->btf; | |
4338 | const char *start, *end; | |
4339 | ||
f80442a4 | 4340 | hdr = &btf->hdr; |
69b693f0 MKL |
4341 | start = btf->nohdr_data + hdr->str_off; |
4342 | end = start + hdr->str_len; | |
4343 | ||
f80442a4 MKL |
4344 | if (end != btf->data + btf->data_size) { |
4345 | btf_verifier_log(env, "String section is not at the end"); | |
4346 | return -EINVAL; | |
4347 | } | |
4348 | ||
951bb646 AN |
4349 | btf->strings = start; |
4350 | ||
4351 | if (btf->base_btf && !hdr->str_len) | |
4352 | return 0; | |
4353 | if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET || end[-1]) { | |
4354 | btf_verifier_log(env, "Invalid string section"); | |
4355 | return -EINVAL; | |
4356 | } | |
4357 | if (!btf->base_btf && start[0]) { | |
69b693f0 MKL |
4358 | btf_verifier_log(env, "Invalid string section"); |
4359 | return -EINVAL; | |
4360 | } | |
69b693f0 MKL |
4361 | |
4362 | return 0; | |
4363 | } | |
4364 | ||
f80442a4 MKL |
4365 | static const size_t btf_sec_info_offset[] = { |
4366 | offsetof(struct btf_header, type_off), | |
4367 | offsetof(struct btf_header, str_off), | |
4368 | }; | |
4369 | ||
4370 | static int btf_sec_info_cmp(const void *a, const void *b) | |
69b693f0 | 4371 | { |
f80442a4 MKL |
4372 | const struct btf_sec_info *x = a; |
4373 | const struct btf_sec_info *y = b; | |
4374 | ||
4375 | return (int)(x->off - y->off) ? : (int)(x->len - y->len); | |
4376 | } | |
4377 | ||
4378 | static int btf_check_sec_info(struct btf_verifier_env *env, | |
4379 | u32 btf_data_size) | |
4380 | { | |
a2889a4c | 4381 | struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)]; |
f80442a4 | 4382 | u32 total, expected_total, i; |
69b693f0 | 4383 | const struct btf_header *hdr; |
f80442a4 MKL |
4384 | const struct btf *btf; |
4385 | ||
4386 | btf = env->btf; | |
4387 | hdr = &btf->hdr; | |
4388 | ||
4389 | /* Populate the secs from hdr */ | |
a2889a4c | 4390 | for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) |
f80442a4 MKL |
4391 | secs[i] = *(struct btf_sec_info *)((void *)hdr + |
4392 | btf_sec_info_offset[i]); | |
4393 | ||
a2889a4c MKL |
4394 | sort(secs, ARRAY_SIZE(btf_sec_info_offset), |
4395 | sizeof(struct btf_sec_info), btf_sec_info_cmp, NULL); | |
f80442a4 MKL |
4396 | |
4397 | /* Check for gaps and overlap among sections */ | |
4398 | total = 0; | |
4399 | expected_total = btf_data_size - hdr->hdr_len; | |
a2889a4c | 4400 | for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) { |
f80442a4 MKL |
4401 | if (expected_total < secs[i].off) { |
4402 | btf_verifier_log(env, "Invalid section offset"); | |
4403 | return -EINVAL; | |
4404 | } | |
4405 | if (total < secs[i].off) { | |
4406 | /* gap */ | |
4407 | btf_verifier_log(env, "Unsupported section found"); | |
4408 | return -EINVAL; | |
4409 | } | |
4410 | if (total > secs[i].off) { | |
4411 | btf_verifier_log(env, "Section overlap found"); | |
4412 | return -EINVAL; | |
4413 | } | |
4414 | if (expected_total - total < secs[i].len) { | |
4415 | btf_verifier_log(env, | |
4416 | "Total section length too long"); | |
4417 | return -EINVAL; | |
4418 | } | |
4419 | total += secs[i].len; | |
4420 | } | |
4421 | ||
4422 | /* There is data other than hdr and known sections */ | |
4423 | if (expected_total != total) { | |
4424 | btf_verifier_log(env, "Unsupported section found"); | |
4425 | return -EINVAL; | |
4426 | } | |
4427 | ||
4428 | return 0; | |
4429 | } | |
4430 | ||
4a6998af | 4431 | static int btf_parse_hdr(struct btf_verifier_env *env) |
f80442a4 | 4432 | { |
4a6998af | 4433 | u32 hdr_len, hdr_copy, btf_data_size; |
f80442a4 | 4434 | const struct btf_header *hdr; |
f80442a4 MKL |
4435 | struct btf *btf; |
4436 | int err; | |
69b693f0 | 4437 | |
f80442a4 | 4438 | btf = env->btf; |
4a6998af | 4439 | btf_data_size = btf->data_size; |
f80442a4 | 4440 | |
4a6998af ML |
4441 | if (btf_data_size < |
4442 | offsetof(struct btf_header, hdr_len) + sizeof(hdr->hdr_len)) { | |
f80442a4 MKL |
4443 | btf_verifier_log(env, "hdr_len not found"); |
4444 | return -EINVAL; | |
4445 | } | |
4446 | ||
4a6998af ML |
4447 | hdr = btf->data; |
4448 | hdr_len = hdr->hdr_len; | |
f80442a4 | 4449 | if (btf_data_size < hdr_len) { |
69b693f0 MKL |
4450 | btf_verifier_log(env, "btf_header not found"); |
4451 | return -EINVAL; | |
4452 | } | |
4453 | ||
4a6998af ML |
4454 | /* Ensure the unsupported header fields are zero */ |
4455 | if (hdr_len > sizeof(btf->hdr)) { | |
4456 | u8 *expected_zero = btf->data + sizeof(btf->hdr); | |
4457 | u8 *end = btf->data + hdr_len; | |
4458 | ||
4459 | for (; expected_zero < end; expected_zero++) { | |
4460 | if (*expected_zero) { | |
4461 | btf_verifier_log(env, "Unsupported btf_header"); | |
4462 | return -E2BIG; | |
4463 | } | |
4464 | } | |
f80442a4 MKL |
4465 | } |
4466 | ||
4467 | hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr)); | |
4a6998af | 4468 | memcpy(&btf->hdr, btf->data, hdr_copy); |
f80442a4 MKL |
4469 | |
4470 | hdr = &btf->hdr; | |
4471 | ||
4472 | btf_verifier_log_hdr(env, btf_data_size); | |
69b693f0 | 4473 | |
69b693f0 MKL |
4474 | if (hdr->magic != BTF_MAGIC) { |
4475 | btf_verifier_log(env, "Invalid magic"); | |
4476 | return -EINVAL; | |
4477 | } | |
4478 | ||
4479 | if (hdr->version != BTF_VERSION) { | |
4480 | btf_verifier_log(env, "Unsupported version"); | |
4481 | return -ENOTSUPP; | |
4482 | } | |
4483 | ||
4484 | if (hdr->flags) { | |
4485 | btf_verifier_log(env, "Unsupported flags"); | |
4486 | return -ENOTSUPP; | |
4487 | } | |
4488 | ||
bcc5e616 | 4489 | if (!btf->base_btf && btf_data_size == hdr->hdr_len) { |
69b693f0 MKL |
4490 | btf_verifier_log(env, "No data"); |
4491 | return -EINVAL; | |
4492 | } | |
4493 | ||
f80442a4 MKL |
4494 | err = btf_check_sec_info(env, btf_data_size); |
4495 | if (err) | |
4496 | return err; | |
69b693f0 MKL |
4497 | |
4498 | return 0; | |
4499 | } | |
4500 | ||
c571bd75 | 4501 | static struct btf *btf_parse(bpfptr_t btf_data, u32 btf_data_size, |
69b693f0 MKL |
4502 | u32 log_level, char __user *log_ubuf, u32 log_size) |
4503 | { | |
4504 | struct btf_verifier_env *env = NULL; | |
4505 | struct bpf_verifier_log *log; | |
4506 | struct btf *btf = NULL; | |
4507 | u8 *data; | |
4508 | int err; | |
4509 | ||
4510 | if (btf_data_size > BTF_MAX_SIZE) | |
4511 | return ERR_PTR(-E2BIG); | |
4512 | ||
4513 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
4514 | if (!env) | |
4515 | return ERR_PTR(-ENOMEM); | |
4516 | ||
4517 | log = &env->log; | |
4518 | if (log_level || log_ubuf || log_size) { | |
4519 | /* user requested verbose verifier output | |
4520 | * and supplied buffer to store the verification trace | |
4521 | */ | |
4522 | log->level = log_level; | |
4523 | log->ubuf = log_ubuf; | |
4524 | log->len_total = log_size; | |
4525 | ||
4526 | /* log attributes have to be sane */ | |
866de407 | 4527 | if (!bpf_verifier_log_attr_valid(log)) { |
69b693f0 MKL |
4528 | err = -EINVAL; |
4529 | goto errout; | |
4530 | } | |
4531 | } | |
4532 | ||
4533 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
4534 | if (!btf) { | |
4535 | err = -ENOMEM; | |
4536 | goto errout; | |
4537 | } | |
f80442a4 MKL |
4538 | env->btf = btf; |
4539 | ||
69b693f0 MKL |
4540 | data = kvmalloc(btf_data_size, GFP_KERNEL | __GFP_NOWARN); |
4541 | if (!data) { | |
4542 | err = -ENOMEM; | |
4543 | goto errout; | |
4544 | } | |
4545 | ||
4546 | btf->data = data; | |
4547 | btf->data_size = btf_data_size; | |
4548 | ||
c571bd75 | 4549 | if (copy_from_bpfptr(data, btf_data, btf_data_size)) { |
69b693f0 MKL |
4550 | err = -EFAULT; |
4551 | goto errout; | |
4552 | } | |
4553 | ||
4a6998af ML |
4554 | err = btf_parse_hdr(env); |
4555 | if (err) | |
4556 | goto errout; | |
4557 | ||
4558 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
4559 | ||
69b693f0 MKL |
4560 | err = btf_parse_str_sec(env); |
4561 | if (err) | |
4562 | goto errout; | |
4563 | ||
4564 | err = btf_parse_type_sec(env); | |
4565 | if (err) | |
4566 | goto errout; | |
4567 | ||
f80442a4 | 4568 | if (log->level && bpf_verifier_log_full(log)) { |
69b693f0 MKL |
4569 | err = -ENOSPC; |
4570 | goto errout; | |
4571 | } | |
4572 | ||
f80442a4 MKL |
4573 | btf_verifier_env_free(env); |
4574 | refcount_set(&btf->refcnt, 1); | |
4575 | return btf; | |
69b693f0 MKL |
4576 | |
4577 | errout: | |
4578 | btf_verifier_env_free(env); | |
4579 | if (btf) | |
4580 | btf_free(btf); | |
4581 | return ERR_PTR(err); | |
4582 | } | |
b00b8dae | 4583 | |
90ceddcb FS |
4584 | extern char __weak __start_BTF[]; |
4585 | extern char __weak __stop_BTF[]; | |
91cc1a99 AS |
4586 | extern struct btf *btf_vmlinux; |
4587 | ||
4588 | #define BPF_MAP_TYPE(_id, _ops) | |
f2e10bff | 4589 | #define BPF_LINK_TYPE(_id, _name) |
91cc1a99 AS |
4590 | static union { |
4591 | struct bpf_ctx_convert { | |
4592 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
4593 | prog_ctx_type _id##_prog; \ | |
4594 | kern_ctx_type _id##_kern; | |
4595 | #include <linux/bpf_types.h> | |
4596 | #undef BPF_PROG_TYPE | |
4597 | } *__t; | |
4598 | /* 't' is written once under lock. Read many times. */ | |
4599 | const struct btf_type *t; | |
4600 | } bpf_ctx_convert; | |
4601 | enum { | |
4602 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
4603 | __ctx_convert##_id, | |
4604 | #include <linux/bpf_types.h> | |
4605 | #undef BPF_PROG_TYPE | |
ce27709b | 4606 | __ctx_convert_unused, /* to avoid empty enum in extreme .config */ |
91cc1a99 AS |
4607 | }; |
4608 | static u8 bpf_ctx_convert_map[] = { | |
4609 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ | |
4610 | [_id] = __ctx_convert##_id, | |
4611 | #include <linux/bpf_types.h> | |
4612 | #undef BPF_PROG_TYPE | |
4c80c7bc | 4613 | 0, /* avoid empty array */ |
91cc1a99 AS |
4614 | }; |
4615 | #undef BPF_MAP_TYPE | |
f2e10bff | 4616 | #undef BPF_LINK_TYPE |
91cc1a99 AS |
4617 | |
4618 | static const struct btf_member * | |
34747c41 | 4619 | btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf, |
51c39bb1 AS |
4620 | const struct btf_type *t, enum bpf_prog_type prog_type, |
4621 | int arg) | |
91cc1a99 AS |
4622 | { |
4623 | const struct btf_type *conv_struct; | |
4624 | const struct btf_type *ctx_struct; | |
4625 | const struct btf_member *ctx_type; | |
4626 | const char *tname, *ctx_tname; | |
4627 | ||
4628 | conv_struct = bpf_ctx_convert.t; | |
4629 | if (!conv_struct) { | |
4630 | bpf_log(log, "btf_vmlinux is malformed\n"); | |
4631 | return NULL; | |
4632 | } | |
4633 | t = btf_type_by_id(btf, t->type); | |
4634 | while (btf_type_is_modifier(t)) | |
4635 | t = btf_type_by_id(btf, t->type); | |
4636 | if (!btf_type_is_struct(t)) { | |
4637 | /* Only pointer to struct is supported for now. | |
4638 | * That means that BPF_PROG_TYPE_TRACEPOINT with BTF | |
4639 | * is not supported yet. | |
4640 | * BPF_PROG_TYPE_RAW_TRACEPOINT is fine. | |
4641 | */ | |
91cc1a99 AS |
4642 | return NULL; |
4643 | } | |
4644 | tname = btf_name_by_offset(btf, t->name_off); | |
4645 | if (!tname) { | |
51c39bb1 | 4646 | bpf_log(log, "arg#%d struct doesn't have a name\n", arg); |
91cc1a99 AS |
4647 | return NULL; |
4648 | } | |
4649 | /* prog_type is valid bpf program type. No need for bounds check. */ | |
4650 | ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2; | |
4651 | /* ctx_struct is a pointer to prog_ctx_type in vmlinux. | |
4652 | * Like 'struct __sk_buff' | |
4653 | */ | |
4654 | ctx_struct = btf_type_by_id(btf_vmlinux, ctx_type->type); | |
4655 | if (!ctx_struct) | |
4656 | /* should not happen */ | |
4657 | return NULL; | |
4658 | ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_struct->name_off); | |
4659 | if (!ctx_tname) { | |
4660 | /* should not happen */ | |
4661 | bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n"); | |
4662 | return NULL; | |
4663 | } | |
4664 | /* only compare that prog's ctx type name is the same as | |
4665 | * kernel expects. No need to compare field by field. | |
4666 | * It's ok for bpf prog to do: | |
4667 | * struct __sk_buff {}; | |
4668 | * int socket_filter_bpf_prog(struct __sk_buff *skb) | |
4669 | * { // no fields of skb are ever used } | |
4670 | */ | |
4671 | if (strcmp(ctx_tname, tname)) | |
4672 | return NULL; | |
4673 | return ctx_type; | |
4674 | } | |
8580ac94 | 4675 | |
41c48f3a AI |
4676 | static const struct bpf_map_ops * const btf_vmlinux_map_ops[] = { |
4677 | #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) | |
4678 | #define BPF_LINK_TYPE(_id, _name) | |
4679 | #define BPF_MAP_TYPE(_id, _ops) \ | |
4680 | [_id] = &_ops, | |
4681 | #include <linux/bpf_types.h> | |
4682 | #undef BPF_PROG_TYPE | |
4683 | #undef BPF_LINK_TYPE | |
4684 | #undef BPF_MAP_TYPE | |
4685 | }; | |
4686 | ||
4687 | static int btf_vmlinux_map_ids_init(const struct btf *btf, | |
4688 | struct bpf_verifier_log *log) | |
4689 | { | |
4690 | const struct bpf_map_ops *ops; | |
4691 | int i, btf_id; | |
4692 | ||
4693 | for (i = 0; i < ARRAY_SIZE(btf_vmlinux_map_ops); ++i) { | |
4694 | ops = btf_vmlinux_map_ops[i]; | |
4695 | if (!ops || (!ops->map_btf_name && !ops->map_btf_id)) | |
4696 | continue; | |
4697 | if (!ops->map_btf_name || !ops->map_btf_id) { | |
4698 | bpf_log(log, "map type %d is misconfigured\n", i); | |
4699 | return -EINVAL; | |
4700 | } | |
4701 | btf_id = btf_find_by_name_kind(btf, ops->map_btf_name, | |
4702 | BTF_KIND_STRUCT); | |
4703 | if (btf_id < 0) | |
4704 | return btf_id; | |
4705 | *ops->map_btf_id = btf_id; | |
4706 | } | |
4707 | ||
4708 | return 0; | |
4709 | } | |
4710 | ||
5b92a28a AS |
4711 | static int btf_translate_to_vmlinux(struct bpf_verifier_log *log, |
4712 | struct btf *btf, | |
4713 | const struct btf_type *t, | |
51c39bb1 AS |
4714 | enum bpf_prog_type prog_type, |
4715 | int arg) | |
5b92a28a AS |
4716 | { |
4717 | const struct btf_member *prog_ctx_type, *kern_ctx_type; | |
4718 | ||
51c39bb1 | 4719 | prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type, arg); |
5b92a28a AS |
4720 | if (!prog_ctx_type) |
4721 | return -ENOENT; | |
4722 | kern_ctx_type = prog_ctx_type + 1; | |
4723 | return kern_ctx_type->type; | |
4724 | } | |
4725 | ||
49f4e672 JO |
4726 | BTF_ID_LIST(bpf_ctx_convert_btf_id) |
4727 | BTF_ID(struct, bpf_ctx_convert) | |
4728 | ||
8580ac94 AS |
4729 | struct btf *btf_parse_vmlinux(void) |
4730 | { | |
4731 | struct btf_verifier_env *env = NULL; | |
4732 | struct bpf_verifier_log *log; | |
4733 | struct btf *btf = NULL; | |
49f4e672 | 4734 | int err; |
8580ac94 AS |
4735 | |
4736 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
4737 | if (!env) | |
4738 | return ERR_PTR(-ENOMEM); | |
4739 | ||
4740 | log = &env->log; | |
4741 | log->level = BPF_LOG_KERNEL; | |
4742 | ||
4743 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
4744 | if (!btf) { | |
4745 | err = -ENOMEM; | |
4746 | goto errout; | |
4747 | } | |
4748 | env->btf = btf; | |
4749 | ||
90ceddcb FS |
4750 | btf->data = __start_BTF; |
4751 | btf->data_size = __stop_BTF - __start_BTF; | |
53297220 AN |
4752 | btf->kernel_btf = true; |
4753 | snprintf(btf->name, sizeof(btf->name), "vmlinux"); | |
8580ac94 AS |
4754 | |
4755 | err = btf_parse_hdr(env); | |
4756 | if (err) | |
4757 | goto errout; | |
4758 | ||
4759 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
4760 | ||
4761 | err = btf_parse_str_sec(env); | |
4762 | if (err) | |
4763 | goto errout; | |
4764 | ||
4765 | err = btf_check_all_metas(env); | |
4766 | if (err) | |
4767 | goto errout; | |
4768 | ||
a2d0d62f | 4769 | /* btf_parse_vmlinux() runs under bpf_verifier_lock */ |
49f4e672 | 4770 | bpf_ctx_convert.t = btf_type_by_id(btf, bpf_ctx_convert_btf_id[0]); |
91cc1a99 | 4771 | |
41c48f3a AI |
4772 | /* find bpf map structs for map_ptr access checking */ |
4773 | err = btf_vmlinux_map_ids_init(btf, log); | |
4774 | if (err < 0) | |
4775 | goto errout; | |
4776 | ||
d3e42bb0 | 4777 | bpf_struct_ops_init(btf, log); |
27ae7997 | 4778 | |
8580ac94 | 4779 | refcount_set(&btf->refcnt, 1); |
53297220 AN |
4780 | |
4781 | err = btf_alloc_id(btf); | |
4782 | if (err) | |
4783 | goto errout; | |
4784 | ||
4785 | btf_verifier_env_free(env); | |
8580ac94 AS |
4786 | return btf; |
4787 | ||
4788 | errout: | |
4789 | btf_verifier_env_free(env); | |
4790 | if (btf) { | |
4791 | kvfree(btf->types); | |
4792 | kfree(btf); | |
4793 | } | |
4794 | return ERR_PTR(err); | |
4795 | } | |
4796 | ||
7112d127 AN |
4797 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
4798 | ||
36e68442 AN |
4799 | static struct btf *btf_parse_module(const char *module_name, const void *data, unsigned int data_size) |
4800 | { | |
4801 | struct btf_verifier_env *env = NULL; | |
4802 | struct bpf_verifier_log *log; | |
4803 | struct btf *btf = NULL, *base_btf; | |
4804 | int err; | |
4805 | ||
4806 | base_btf = bpf_get_btf_vmlinux(); | |
4807 | if (IS_ERR(base_btf)) | |
4808 | return base_btf; | |
4809 | if (!base_btf) | |
4810 | return ERR_PTR(-EINVAL); | |
4811 | ||
4812 | env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); | |
4813 | if (!env) | |
4814 | return ERR_PTR(-ENOMEM); | |
4815 | ||
4816 | log = &env->log; | |
4817 | log->level = BPF_LOG_KERNEL; | |
4818 | ||
4819 | btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); | |
4820 | if (!btf) { | |
4821 | err = -ENOMEM; | |
4822 | goto errout; | |
4823 | } | |
4824 | env->btf = btf; | |
4825 | ||
4826 | btf->base_btf = base_btf; | |
4827 | btf->start_id = base_btf->nr_types; | |
4828 | btf->start_str_off = base_btf->hdr.str_len; | |
4829 | btf->kernel_btf = true; | |
4830 | snprintf(btf->name, sizeof(btf->name), "%s", module_name); | |
4831 | ||
4832 | btf->data = kvmalloc(data_size, GFP_KERNEL | __GFP_NOWARN); | |
4833 | if (!btf->data) { | |
4834 | err = -ENOMEM; | |
4835 | goto errout; | |
4836 | } | |
4837 | memcpy(btf->data, data, data_size); | |
4838 | btf->data_size = data_size; | |
4839 | ||
4840 | err = btf_parse_hdr(env); | |
4841 | if (err) | |
4842 | goto errout; | |
4843 | ||
4844 | btf->nohdr_data = btf->data + btf->hdr.hdr_len; | |
4845 | ||
4846 | err = btf_parse_str_sec(env); | |
4847 | if (err) | |
4848 | goto errout; | |
4849 | ||
4850 | err = btf_check_all_metas(env); | |
4851 | if (err) | |
4852 | goto errout; | |
4853 | ||
4854 | btf_verifier_env_free(env); | |
4855 | refcount_set(&btf->refcnt, 1); | |
4856 | return btf; | |
4857 | ||
4858 | errout: | |
4859 | btf_verifier_env_free(env); | |
4860 | if (btf) { | |
4861 | kvfree(btf->data); | |
4862 | kvfree(btf->types); | |
4863 | kfree(btf); | |
4864 | } | |
4865 | return ERR_PTR(err); | |
4866 | } | |
4867 | ||
7112d127 AN |
4868 | #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */ |
4869 | ||
5b92a28a AS |
4870 | struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog) |
4871 | { | |
3aac1ead | 4872 | struct bpf_prog *tgt_prog = prog->aux->dst_prog; |
5b92a28a | 4873 | |
22dc4a0f | 4874 | if (tgt_prog) |
5b92a28a | 4875 | return tgt_prog->aux->btf; |
22dc4a0f AN |
4876 | else |
4877 | return prog->aux->attach_btf; | |
5b92a28a AS |
4878 | } |
4879 | ||
bb6728d7 | 4880 | static bool is_int_ptr(struct btf *btf, const struct btf_type *t) |
84ad7a7a JO |
4881 | { |
4882 | /* t comes in already as a pointer */ | |
4883 | t = btf_type_by_id(btf, t->type); | |
4884 | ||
4885 | /* allow const */ | |
4886 | if (BTF_INFO_KIND(t->info) == BTF_KIND_CONST) | |
4887 | t = btf_type_by_id(btf, t->type); | |
4888 | ||
bb6728d7 | 4889 | return btf_type_is_int(t); |
84ad7a7a JO |
4890 | } |
4891 | ||
9e15db66 AS |
4892 | bool btf_ctx_access(int off, int size, enum bpf_access_type type, |
4893 | const struct bpf_prog *prog, | |
4894 | struct bpf_insn_access_aux *info) | |
4895 | { | |
38207291 | 4896 | const struct btf_type *t = prog->aux->attach_func_proto; |
3aac1ead | 4897 | struct bpf_prog *tgt_prog = prog->aux->dst_prog; |
5b92a28a | 4898 | struct btf *btf = bpf_prog_get_target_btf(prog); |
38207291 | 4899 | const char *tname = prog->aux->attach_func_name; |
9e15db66 | 4900 | struct bpf_verifier_log *log = info->log; |
9e15db66 | 4901 | const struct btf_param *args; |
c6f1bfe8 | 4902 | const char *tag_value; |
9e15db66 | 4903 | u32 nr_args, arg; |
3c32cc1b | 4904 | int i, ret; |
9e15db66 | 4905 | |
9e15db66 | 4906 | if (off % 8) { |
38207291 | 4907 | bpf_log(log, "func '%s' offset %d is not multiple of 8\n", |
9e15db66 AS |
4908 | tname, off); |
4909 | return false; | |
4910 | } | |
4911 | arg = off / 8; | |
4912 | args = (const struct btf_param *)(t + 1); | |
523a4cf4 DB |
4913 | /* if (t == NULL) Fall back to default BPF prog with |
4914 | * MAX_BPF_FUNC_REG_ARGS u64 arguments. | |
4915 | */ | |
4916 | nr_args = t ? btf_type_vlen(t) : MAX_BPF_FUNC_REG_ARGS; | |
38207291 MKL |
4917 | if (prog->aux->attach_btf_trace) { |
4918 | /* skip first 'void *__data' argument in btf_trace_##name typedef */ | |
4919 | args++; | |
4920 | nr_args--; | |
4921 | } | |
fec56f58 | 4922 | |
f50b49a0 KS |
4923 | if (arg > nr_args) { |
4924 | bpf_log(log, "func '%s' doesn't have %d-th argument\n", | |
4925 | tname, arg + 1); | |
4926 | return false; | |
4927 | } | |
4928 | ||
6ba43b76 | 4929 | if (arg == nr_args) { |
f50b49a0 KS |
4930 | switch (prog->expected_attach_type) { |
4931 | case BPF_LSM_MAC: | |
4932 | case BPF_TRACE_FEXIT: | |
9e4e01df KS |
4933 | /* When LSM programs are attached to void LSM hooks |
4934 | * they use FEXIT trampolines and when attached to | |
4935 | * int LSM hooks, they use MODIFY_RETURN trampolines. | |
4936 | * | |
4937 | * While the LSM programs are BPF_MODIFY_RETURN-like | |
4938 | * the check: | |
4939 | * | |
4940 | * if (ret_type != 'int') | |
4941 | * return -EINVAL; | |
4942 | * | |
4943 | * is _not_ done here. This is still safe as LSM hooks | |
4944 | * have only void and int return types. | |
4945 | */ | |
6ba43b76 KS |
4946 | if (!t) |
4947 | return true; | |
4948 | t = btf_type_by_id(btf, t->type); | |
f50b49a0 KS |
4949 | break; |
4950 | case BPF_MODIFY_RETURN: | |
6ba43b76 KS |
4951 | /* For now the BPF_MODIFY_RETURN can only be attached to |
4952 | * functions that return an int. | |
4953 | */ | |
4954 | if (!t) | |
4955 | return false; | |
4956 | ||
4957 | t = btf_type_skip_modifiers(btf, t->type, NULL); | |
a9b59159 | 4958 | if (!btf_type_is_small_int(t)) { |
6ba43b76 KS |
4959 | bpf_log(log, |
4960 | "ret type %s not allowed for fmod_ret\n", | |
4961 | btf_kind_str[BTF_INFO_KIND(t->info)]); | |
4962 | return false; | |
4963 | } | |
f50b49a0 KS |
4964 | break; |
4965 | default: | |
4966 | bpf_log(log, "func '%s' doesn't have %d-th argument\n", | |
4967 | tname, arg + 1); | |
4968 | return false; | |
6ba43b76 | 4969 | } |
fec56f58 | 4970 | } else { |
5b92a28a | 4971 | if (!t) |
523a4cf4 | 4972 | /* Default prog with MAX_BPF_FUNC_REG_ARGS args */ |
5b92a28a AS |
4973 | return true; |
4974 | t = btf_type_by_id(btf, args[arg].type); | |
9e15db66 | 4975 | } |
f50b49a0 | 4976 | |
9e15db66 AS |
4977 | /* skip modifiers */ |
4978 | while (btf_type_is_modifier(t)) | |
5b92a28a | 4979 | t = btf_type_by_id(btf, t->type); |
a9b59159 | 4980 | if (btf_type_is_small_int(t) || btf_type_is_enum(t)) |
9e15db66 AS |
4981 | /* accessing a scalar */ |
4982 | return true; | |
4983 | if (!btf_type_is_ptr(t)) { | |
4984 | bpf_log(log, | |
38207291 | 4985 | "func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n", |
9e15db66 | 4986 | tname, arg, |
5b92a28a | 4987 | __btf_name_by_offset(btf, t->name_off), |
9e15db66 AS |
4988 | btf_kind_str[BTF_INFO_KIND(t->info)]); |
4989 | return false; | |
4990 | } | |
afbf21dc YS |
4991 | |
4992 | /* check for PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL */ | |
4993 | for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { | |
4994 | const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; | |
c25b2ae1 | 4995 | u32 type, flag; |
afbf21dc | 4996 | |
c25b2ae1 HL |
4997 | type = base_type(ctx_arg_info->reg_type); |
4998 | flag = type_flag(ctx_arg_info->reg_type); | |
20b2aff4 | 4999 | if (ctx_arg_info->offset == off && type == PTR_TO_BUF && |
c25b2ae1 | 5000 | (flag & PTR_MAYBE_NULL)) { |
afbf21dc YS |
5001 | info->reg_type = ctx_arg_info->reg_type; |
5002 | return true; | |
5003 | } | |
5004 | } | |
5005 | ||
9e15db66 AS |
5006 | if (t->type == 0) |
5007 | /* This is a pointer to void. | |
5008 | * It is the same as scalar from the verifier safety pov. | |
5009 | * No further pointer walking is allowed. | |
5010 | */ | |
5011 | return true; | |
5012 | ||
bb6728d7 | 5013 | if (is_int_ptr(btf, t)) |
84ad7a7a JO |
5014 | return true; |
5015 | ||
9e15db66 | 5016 | /* this is a pointer to another type */ |
3c32cc1b YS |
5017 | for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { |
5018 | const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; | |
5019 | ||
5020 | if (ctx_arg_info->offset == off) { | |
d3621642 YS |
5021 | if (!ctx_arg_info->btf_id) { |
5022 | bpf_log(log,"invalid btf_id for context argument offset %u\n", off); | |
5023 | return false; | |
5024 | } | |
5025 | ||
3c32cc1b | 5026 | info->reg_type = ctx_arg_info->reg_type; |
22dc4a0f | 5027 | info->btf = btf_vmlinux; |
951cf368 YS |
5028 | info->btf_id = ctx_arg_info->btf_id; |
5029 | return true; | |
3c32cc1b YS |
5030 | } |
5031 | } | |
9e15db66 | 5032 | |
951cf368 | 5033 | info->reg_type = PTR_TO_BTF_ID; |
5b92a28a | 5034 | if (tgt_prog) { |
43bc2874 THJ |
5035 | enum bpf_prog_type tgt_type; |
5036 | ||
5037 | if (tgt_prog->type == BPF_PROG_TYPE_EXT) | |
5038 | tgt_type = tgt_prog->aux->saved_dst_prog_type; | |
5039 | else | |
5040 | tgt_type = tgt_prog->type; | |
5041 | ||
5042 | ret = btf_translate_to_vmlinux(log, btf, t, tgt_type, arg); | |
5b92a28a | 5043 | if (ret > 0) { |
22dc4a0f | 5044 | info->btf = btf_vmlinux; |
5b92a28a AS |
5045 | info->btf_id = ret; |
5046 | return true; | |
5047 | } else { | |
5048 | return false; | |
5049 | } | |
5050 | } | |
275517ff | 5051 | |
22dc4a0f | 5052 | info->btf = btf; |
275517ff | 5053 | info->btf_id = t->type; |
5b92a28a | 5054 | t = btf_type_by_id(btf, t->type); |
c6f1bfe8 YS |
5055 | |
5056 | if (btf_type_is_type_tag(t)) { | |
5057 | tag_value = __btf_name_by_offset(btf, t->name_off); | |
5058 | if (strcmp(tag_value, "user") == 0) | |
5059 | info->reg_type |= MEM_USER; | |
5060 | } | |
5061 | ||
9e15db66 | 5062 | /* skip modifiers */ |
275517ff MKL |
5063 | while (btf_type_is_modifier(t)) { |
5064 | info->btf_id = t->type; | |
5b92a28a | 5065 | t = btf_type_by_id(btf, t->type); |
275517ff | 5066 | } |
9e15db66 AS |
5067 | if (!btf_type_is_struct(t)) { |
5068 | bpf_log(log, | |
38207291 | 5069 | "func '%s' arg%d type %s is not a struct\n", |
9e15db66 AS |
5070 | tname, arg, btf_kind_str[BTF_INFO_KIND(t->info)]); |
5071 | return false; | |
5072 | } | |
38207291 | 5073 | bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n", |
9e15db66 | 5074 | tname, arg, info->btf_id, btf_kind_str[BTF_INFO_KIND(t->info)], |
5b92a28a | 5075 | __btf_name_by_offset(btf, t->name_off)); |
9e15db66 AS |
5076 | return true; |
5077 | } | |
5078 | ||
1c6d28a6 JO |
5079 | enum bpf_struct_walk_result { |
5080 | /* < 0 error */ | |
5081 | WALK_SCALAR = 0, | |
5082 | WALK_PTR, | |
5083 | WALK_STRUCT, | |
5084 | }; | |
5085 | ||
22dc4a0f | 5086 | static int btf_struct_walk(struct bpf_verifier_log *log, const struct btf *btf, |
1c6d28a6 | 5087 | const struct btf_type *t, int off, int size, |
c6f1bfe8 | 5088 | u32 *next_btf_id, enum bpf_type_flag *flag) |
9e15db66 | 5089 | { |
7e3617a7 MKL |
5090 | u32 i, moff, mtrue_end, msize = 0, total_nelems = 0; |
5091 | const struct btf_type *mtype, *elem_type = NULL; | |
9e15db66 | 5092 | const struct btf_member *member; |
c6f1bfe8 | 5093 | const char *tname, *mname, *tag_value; |
1c6d28a6 | 5094 | u32 vlen, elem_id, mid; |
9e15db66 AS |
5095 | |
5096 | again: | |
22dc4a0f | 5097 | tname = __btf_name_by_offset(btf, t->name_off); |
9e15db66 | 5098 | if (!btf_type_is_struct(t)) { |
275517ff | 5099 | bpf_log(log, "Type '%s' is not a struct\n", tname); |
9e15db66 AS |
5100 | return -EINVAL; |
5101 | } | |
5102 | ||
9c5f8a10 | 5103 | vlen = btf_type_vlen(t); |
976aba00 | 5104 | if (off + size > t->size) { |
9c5f8a10 YS |
5105 | /* If the last element is a variable size array, we may |
5106 | * need to relax the rule. | |
5107 | */ | |
5108 | struct btf_array *array_elem; | |
5109 | ||
5110 | if (vlen == 0) | |
5111 | goto error; | |
5112 | ||
5113 | member = btf_type_member(t) + vlen - 1; | |
22dc4a0f | 5114 | mtype = btf_type_skip_modifiers(btf, member->type, |
9c5f8a10 YS |
5115 | NULL); |
5116 | if (!btf_type_is_array(mtype)) | |
5117 | goto error; | |
5118 | ||
5119 | array_elem = (struct btf_array *)(mtype + 1); | |
5120 | if (array_elem->nelems != 0) | |
5121 | goto error; | |
5122 | ||
8293eb99 | 5123 | moff = __btf_member_bit_offset(t, member) / 8; |
9c5f8a10 YS |
5124 | if (off < moff) |
5125 | goto error; | |
5126 | ||
5127 | /* Only allow structure for now, can be relaxed for | |
5128 | * other types later. | |
5129 | */ | |
22dc4a0f | 5130 | t = btf_type_skip_modifiers(btf, array_elem->type, |
dafe58fc JO |
5131 | NULL); |
5132 | if (!btf_type_is_struct(t)) | |
9c5f8a10 YS |
5133 | goto error; |
5134 | ||
dafe58fc JO |
5135 | off = (off - moff) % t->size; |
5136 | goto again; | |
9c5f8a10 YS |
5137 | |
5138 | error: | |
976aba00 MKL |
5139 | bpf_log(log, "access beyond struct %s at off %u size %u\n", |
5140 | tname, off, size); | |
5141 | return -EACCES; | |
5142 | } | |
9e15db66 | 5143 | |
976aba00 | 5144 | for_each_member(i, t, member) { |
7e3617a7 | 5145 | /* offset of the field in bytes */ |
8293eb99 | 5146 | moff = __btf_member_bit_offset(t, member) / 8; |
7e3617a7 | 5147 | if (off + size <= moff) |
9e15db66 AS |
5148 | /* won't find anything, field is already too far */ |
5149 | break; | |
976aba00 | 5150 | |
8293eb99 AS |
5151 | if (__btf_member_bitfield_size(t, member)) { |
5152 | u32 end_bit = __btf_member_bit_offset(t, member) + | |
5153 | __btf_member_bitfield_size(t, member); | |
976aba00 MKL |
5154 | |
5155 | /* off <= moff instead of off == moff because clang | |
5156 | * does not generate a BTF member for anonymous | |
5157 | * bitfield like the ":16" here: | |
5158 | * struct { | |
5159 | * int :16; | |
5160 | * int x:8; | |
5161 | * }; | |
5162 | */ | |
5163 | if (off <= moff && | |
5164 | BITS_ROUNDUP_BYTES(end_bit) <= off + size) | |
1c6d28a6 | 5165 | return WALK_SCALAR; |
976aba00 MKL |
5166 | |
5167 | /* off may be accessing a following member | |
5168 | * | |
5169 | * or | |
5170 | * | |
5171 | * Doing partial access at either end of this | |
5172 | * bitfield. Continue on this case also to | |
5173 | * treat it as not accessing this bitfield | |
5174 | * and eventually error out as field not | |
5175 | * found to keep it simple. | |
5176 | * It could be relaxed if there was a legit | |
5177 | * partial access case later. | |
5178 | */ | |
5179 | continue; | |
5180 | } | |
5181 | ||
7e3617a7 MKL |
5182 | /* In case of "off" is pointing to holes of a struct */ |
5183 | if (off < moff) | |
976aba00 | 5184 | break; |
9e15db66 AS |
5185 | |
5186 | /* type of the field */ | |
1c6d28a6 | 5187 | mid = member->type; |
22dc4a0f AN |
5188 | mtype = btf_type_by_id(btf, member->type); |
5189 | mname = __btf_name_by_offset(btf, member->name_off); | |
9e15db66 | 5190 | |
22dc4a0f | 5191 | mtype = __btf_resolve_size(btf, mtype, &msize, |
1c6d28a6 JO |
5192 | &elem_type, &elem_id, &total_nelems, |
5193 | &mid); | |
7e3617a7 | 5194 | if (IS_ERR(mtype)) { |
9e15db66 AS |
5195 | bpf_log(log, "field %s doesn't have size\n", mname); |
5196 | return -EFAULT; | |
5197 | } | |
7e3617a7 MKL |
5198 | |
5199 | mtrue_end = moff + msize; | |
5200 | if (off >= mtrue_end) | |
9e15db66 AS |
5201 | /* no overlap with member, keep iterating */ |
5202 | continue; | |
7e3617a7 MKL |
5203 | |
5204 | if (btf_type_is_array(mtype)) { | |
5205 | u32 elem_idx; | |
5206 | ||
6298399b | 5207 | /* __btf_resolve_size() above helps to |
7e3617a7 MKL |
5208 | * linearize a multi-dimensional array. |
5209 | * | |
5210 | * The logic here is treating an array | |
5211 | * in a struct as the following way: | |
5212 | * | |
5213 | * struct outer { | |
5214 | * struct inner array[2][2]; | |
5215 | * }; | |
5216 | * | |
5217 | * looks like: | |
5218 | * | |
5219 | * struct outer { | |
5220 | * struct inner array_elem0; | |
5221 | * struct inner array_elem1; | |
5222 | * struct inner array_elem2; | |
5223 | * struct inner array_elem3; | |
5224 | * }; | |
5225 | * | |
5226 | * When accessing outer->array[1][0], it moves | |
5227 | * moff to "array_elem2", set mtype to | |
5228 | * "struct inner", and msize also becomes | |
5229 | * sizeof(struct inner). Then most of the | |
5230 | * remaining logic will fall through without | |
5231 | * caring the current member is an array or | |
5232 | * not. | |
5233 | * | |
5234 | * Unlike mtype/msize/moff, mtrue_end does not | |
5235 | * change. The naming difference ("_true") tells | |
5236 | * that it is not always corresponding to | |
5237 | * the current mtype/msize/moff. | |
5238 | * It is the true end of the current | |
5239 | * member (i.e. array in this case). That | |
5240 | * will allow an int array to be accessed like | |
5241 | * a scratch space, | |
5242 | * i.e. allow access beyond the size of | |
5243 | * the array's element as long as it is | |
5244 | * within the mtrue_end boundary. | |
5245 | */ | |
5246 | ||
5247 | /* skip empty array */ | |
5248 | if (moff == mtrue_end) | |
5249 | continue; | |
5250 | ||
5251 | msize /= total_nelems; | |
5252 | elem_idx = (off - moff) / msize; | |
5253 | moff += elem_idx * msize; | |
5254 | mtype = elem_type; | |
1c6d28a6 | 5255 | mid = elem_id; |
7e3617a7 MKL |
5256 | } |
5257 | ||
9e15db66 AS |
5258 | /* the 'off' we're looking for is either equal to start |
5259 | * of this field or inside of this struct | |
5260 | */ | |
5261 | if (btf_type_is_struct(mtype)) { | |
5262 | /* our field must be inside that union or struct */ | |
5263 | t = mtype; | |
5264 | ||
1c6d28a6 JO |
5265 | /* return if the offset matches the member offset */ |
5266 | if (off == moff) { | |
5267 | *next_btf_id = mid; | |
5268 | return WALK_STRUCT; | |
5269 | } | |
5270 | ||
9e15db66 | 5271 | /* adjust offset we're looking for */ |
7e3617a7 | 5272 | off -= moff; |
9e15db66 AS |
5273 | goto again; |
5274 | } | |
9e15db66 AS |
5275 | |
5276 | if (btf_type_is_ptr(mtype)) { | |
c6f1bfe8 YS |
5277 | const struct btf_type *stype, *t; |
5278 | enum bpf_type_flag tmp_flag = 0; | |
257af63d | 5279 | u32 id; |
9e15db66 | 5280 | |
7e3617a7 MKL |
5281 | if (msize != size || off != moff) { |
5282 | bpf_log(log, | |
5283 | "cannot access ptr member %s with moff %u in struct %s with off %u size %u\n", | |
5284 | mname, moff, tname, off, size); | |
5285 | return -EACCES; | |
5286 | } | |
c6f1bfe8 YS |
5287 | |
5288 | /* check __user tag */ | |
5289 | t = btf_type_by_id(btf, mtype->type); | |
5290 | if (btf_type_is_type_tag(t)) { | |
5291 | tag_value = __btf_name_by_offset(btf, t->name_off); | |
5292 | if (strcmp(tag_value, "user") == 0) | |
5293 | tmp_flag = MEM_USER; | |
5294 | } | |
5295 | ||
22dc4a0f | 5296 | stype = btf_type_skip_modifiers(btf, mtype->type, &id); |
9e15db66 | 5297 | if (btf_type_is_struct(stype)) { |
257af63d | 5298 | *next_btf_id = id; |
c6f1bfe8 | 5299 | *flag = tmp_flag; |
1c6d28a6 | 5300 | return WALK_PTR; |
9e15db66 AS |
5301 | } |
5302 | } | |
7e3617a7 MKL |
5303 | |
5304 | /* Allow more flexible access within an int as long as | |
5305 | * it is within mtrue_end. | |
5306 | * Since mtrue_end could be the end of an array, | |
5307 | * that also allows using an array of int as a scratch | |
5308 | * space. e.g. skb->cb[]. | |
5309 | */ | |
5310 | if (off + size > mtrue_end) { | |
5311 | bpf_log(log, | |
5312 | "access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n", | |
5313 | mname, mtrue_end, tname, off, size); | |
5314 | return -EACCES; | |
5315 | } | |
5316 | ||
1c6d28a6 | 5317 | return WALK_SCALAR; |
9e15db66 AS |
5318 | } |
5319 | bpf_log(log, "struct %s doesn't have field at offset %d\n", tname, off); | |
5320 | return -EINVAL; | |
5321 | } | |
5322 | ||
22dc4a0f | 5323 | int btf_struct_access(struct bpf_verifier_log *log, const struct btf *btf, |
1c6d28a6 JO |
5324 | const struct btf_type *t, int off, int size, |
5325 | enum bpf_access_type atype __maybe_unused, | |
c6f1bfe8 | 5326 | u32 *next_btf_id, enum bpf_type_flag *flag) |
1c6d28a6 | 5327 | { |
c6f1bfe8 | 5328 | enum bpf_type_flag tmp_flag = 0; |
1c6d28a6 JO |
5329 | int err; |
5330 | u32 id; | |
5331 | ||
5332 | do { | |
c6f1bfe8 | 5333 | err = btf_struct_walk(log, btf, t, off, size, &id, &tmp_flag); |
1c6d28a6 JO |
5334 | |
5335 | switch (err) { | |
5336 | case WALK_PTR: | |
5337 | /* If we found the pointer or scalar on t+off, | |
5338 | * we're done. | |
5339 | */ | |
5340 | *next_btf_id = id; | |
c6f1bfe8 | 5341 | *flag = tmp_flag; |
1c6d28a6 JO |
5342 | return PTR_TO_BTF_ID; |
5343 | case WALK_SCALAR: | |
5344 | return SCALAR_VALUE; | |
5345 | case WALK_STRUCT: | |
5346 | /* We found nested struct, so continue the search | |
5347 | * by diving in it. At this point the offset is | |
5348 | * aligned with the new type, so set it to 0. | |
5349 | */ | |
22dc4a0f | 5350 | t = btf_type_by_id(btf, id); |
1c6d28a6 JO |
5351 | off = 0; |
5352 | break; | |
5353 | default: | |
5354 | /* It's either error or unknown return value.. | |
5355 | * scream and leave. | |
5356 | */ | |
5357 | if (WARN_ONCE(err > 0, "unknown btf_struct_walk return value")) | |
5358 | return -EINVAL; | |
5359 | return err; | |
5360 | } | |
5361 | } while (t); | |
5362 | ||
5363 | return -EINVAL; | |
5364 | } | |
5365 | ||
22dc4a0f AN |
5366 | /* Check that two BTF types, each specified as an BTF object + id, are exactly |
5367 | * the same. Trivial ID check is not enough due to module BTFs, because we can | |
5368 | * end up with two different module BTFs, but IDs point to the common type in | |
5369 | * vmlinux BTF. | |
5370 | */ | |
5371 | static bool btf_types_are_same(const struct btf *btf1, u32 id1, | |
5372 | const struct btf *btf2, u32 id2) | |
5373 | { | |
5374 | if (id1 != id2) | |
5375 | return false; | |
5376 | if (btf1 == btf2) | |
5377 | return true; | |
5378 | return btf_type_by_id(btf1, id1) == btf_type_by_id(btf2, id2); | |
5379 | } | |
5380 | ||
faaf4a79 | 5381 | bool btf_struct_ids_match(struct bpf_verifier_log *log, |
22dc4a0f AN |
5382 | const struct btf *btf, u32 id, int off, |
5383 | const struct btf *need_btf, u32 need_type_id) | |
faaf4a79 JO |
5384 | { |
5385 | const struct btf_type *type; | |
c6f1bfe8 | 5386 | enum bpf_type_flag flag; |
faaf4a79 JO |
5387 | int err; |
5388 | ||
5389 | /* Are we already done? */ | |
22dc4a0f | 5390 | if (off == 0 && btf_types_are_same(btf, id, need_btf, need_type_id)) |
faaf4a79 JO |
5391 | return true; |
5392 | ||
5393 | again: | |
22dc4a0f | 5394 | type = btf_type_by_id(btf, id); |
faaf4a79 JO |
5395 | if (!type) |
5396 | return false; | |
c6f1bfe8 | 5397 | err = btf_struct_walk(log, btf, type, off, 1, &id, &flag); |
faaf4a79 JO |
5398 | if (err != WALK_STRUCT) |
5399 | return false; | |
5400 | ||
5401 | /* We found nested struct object. If it matches | |
5402 | * the requested ID, we're done. Otherwise let's | |
5403 | * continue the search with offset 0 in the new | |
5404 | * type. | |
5405 | */ | |
22dc4a0f | 5406 | if (!btf_types_are_same(btf, id, need_btf, need_type_id)) { |
faaf4a79 JO |
5407 | off = 0; |
5408 | goto again; | |
5409 | } | |
5410 | ||
5411 | return true; | |
5412 | } | |
5413 | ||
fec56f58 AS |
5414 | static int __get_type_size(struct btf *btf, u32 btf_id, |
5415 | const struct btf_type **bad_type) | |
5416 | { | |
5417 | const struct btf_type *t; | |
5418 | ||
5419 | if (!btf_id) | |
5420 | /* void */ | |
5421 | return 0; | |
5422 | t = btf_type_by_id(btf, btf_id); | |
5423 | while (t && btf_type_is_modifier(t)) | |
5424 | t = btf_type_by_id(btf, t->type); | |
d0f01043 | 5425 | if (!t) { |
951bb646 | 5426 | *bad_type = btf_type_by_id(btf, 0); |
fec56f58 | 5427 | return -EINVAL; |
d0f01043 | 5428 | } |
fec56f58 AS |
5429 | if (btf_type_is_ptr(t)) |
5430 | /* kernel size of pointer. Not BPF's size of pointer*/ | |
5431 | return sizeof(void *); | |
5432 | if (btf_type_is_int(t) || btf_type_is_enum(t)) | |
5433 | return t->size; | |
5434 | *bad_type = t; | |
5435 | return -EINVAL; | |
5436 | } | |
5437 | ||
5438 | int btf_distill_func_proto(struct bpf_verifier_log *log, | |
5439 | struct btf *btf, | |
5440 | const struct btf_type *func, | |
5441 | const char *tname, | |
5442 | struct btf_func_model *m) | |
5443 | { | |
5444 | const struct btf_param *args; | |
5445 | const struct btf_type *t; | |
5446 | u32 i, nargs; | |
5447 | int ret; | |
5448 | ||
5b92a28a AS |
5449 | if (!func) { |
5450 | /* BTF function prototype doesn't match the verifier types. | |
523a4cf4 | 5451 | * Fall back to MAX_BPF_FUNC_REG_ARGS u64 args. |
5b92a28a | 5452 | */ |
523a4cf4 | 5453 | for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++) |
5b92a28a AS |
5454 | m->arg_size[i] = 8; |
5455 | m->ret_size = 8; | |
523a4cf4 | 5456 | m->nr_args = MAX_BPF_FUNC_REG_ARGS; |
5b92a28a AS |
5457 | return 0; |
5458 | } | |
fec56f58 AS |
5459 | args = (const struct btf_param *)(func + 1); |
5460 | nargs = btf_type_vlen(func); | |
5461 | if (nargs >= MAX_BPF_FUNC_ARGS) { | |
5462 | bpf_log(log, | |
5463 | "The function %s has %d arguments. Too many.\n", | |
5464 | tname, nargs); | |
5465 | return -EINVAL; | |
5466 | } | |
5467 | ret = __get_type_size(btf, func->type, &t); | |
5468 | if (ret < 0) { | |
5469 | bpf_log(log, | |
5470 | "The function %s return type %s is unsupported.\n", | |
5471 | tname, btf_kind_str[BTF_INFO_KIND(t->info)]); | |
5472 | return -EINVAL; | |
5473 | } | |
5474 | m->ret_size = ret; | |
5475 | ||
5476 | for (i = 0; i < nargs; i++) { | |
31379397 JO |
5477 | if (i == nargs - 1 && args[i].type == 0) { |
5478 | bpf_log(log, | |
5479 | "The function %s with variable args is unsupported.\n", | |
5480 | tname); | |
5481 | return -EINVAL; | |
5482 | } | |
fec56f58 AS |
5483 | ret = __get_type_size(btf, args[i].type, &t); |
5484 | if (ret < 0) { | |
5485 | bpf_log(log, | |
5486 | "The function %s arg%d type %s is unsupported.\n", | |
5487 | tname, i, btf_kind_str[BTF_INFO_KIND(t->info)]); | |
5488 | return -EINVAL; | |
5489 | } | |
31379397 JO |
5490 | if (ret == 0) { |
5491 | bpf_log(log, | |
5492 | "The function %s has malformed void argument.\n", | |
5493 | tname); | |
5494 | return -EINVAL; | |
5495 | } | |
fec56f58 AS |
5496 | m->arg_size[i] = ret; |
5497 | } | |
5498 | m->nr_args = nargs; | |
5499 | return 0; | |
5500 | } | |
5501 | ||
be8704ff AS |
5502 | /* Compare BTFs of two functions assuming only scalars and pointers to context. |
5503 | * t1 points to BTF_KIND_FUNC in btf1 | |
5504 | * t2 points to BTF_KIND_FUNC in btf2 | |
5505 | * Returns: | |
5506 | * EINVAL - function prototype mismatch | |
5507 | * EFAULT - verifier bug | |
5508 | * 0 - 99% match. The last 1% is validated by the verifier. | |
5509 | */ | |
2bf0eb9b HY |
5510 | static int btf_check_func_type_match(struct bpf_verifier_log *log, |
5511 | struct btf *btf1, const struct btf_type *t1, | |
5512 | struct btf *btf2, const struct btf_type *t2) | |
be8704ff AS |
5513 | { |
5514 | const struct btf_param *args1, *args2; | |
5515 | const char *fn1, *fn2, *s1, *s2; | |
5516 | u32 nargs1, nargs2, i; | |
5517 | ||
5518 | fn1 = btf_name_by_offset(btf1, t1->name_off); | |
5519 | fn2 = btf_name_by_offset(btf2, t2->name_off); | |
5520 | ||
5521 | if (btf_func_linkage(t1) != BTF_FUNC_GLOBAL) { | |
5522 | bpf_log(log, "%s() is not a global function\n", fn1); | |
5523 | return -EINVAL; | |
5524 | } | |
5525 | if (btf_func_linkage(t2) != BTF_FUNC_GLOBAL) { | |
5526 | bpf_log(log, "%s() is not a global function\n", fn2); | |
5527 | return -EINVAL; | |
5528 | } | |
5529 | ||
5530 | t1 = btf_type_by_id(btf1, t1->type); | |
5531 | if (!t1 || !btf_type_is_func_proto(t1)) | |
5532 | return -EFAULT; | |
5533 | t2 = btf_type_by_id(btf2, t2->type); | |
5534 | if (!t2 || !btf_type_is_func_proto(t2)) | |
5535 | return -EFAULT; | |
5536 | ||
5537 | args1 = (const struct btf_param *)(t1 + 1); | |
5538 | nargs1 = btf_type_vlen(t1); | |
5539 | args2 = (const struct btf_param *)(t2 + 1); | |
5540 | nargs2 = btf_type_vlen(t2); | |
5541 | ||
5542 | if (nargs1 != nargs2) { | |
5543 | bpf_log(log, "%s() has %d args while %s() has %d args\n", | |
5544 | fn1, nargs1, fn2, nargs2); | |
5545 | return -EINVAL; | |
5546 | } | |
5547 | ||
5548 | t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); | |
5549 | t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); | |
5550 | if (t1->info != t2->info) { | |
5551 | bpf_log(log, | |
5552 | "Return type %s of %s() doesn't match type %s of %s()\n", | |
5553 | btf_type_str(t1), fn1, | |
5554 | btf_type_str(t2), fn2); | |
5555 | return -EINVAL; | |
5556 | } | |
5557 | ||
5558 | for (i = 0; i < nargs1; i++) { | |
5559 | t1 = btf_type_skip_modifiers(btf1, args1[i].type, NULL); | |
5560 | t2 = btf_type_skip_modifiers(btf2, args2[i].type, NULL); | |
5561 | ||
5562 | if (t1->info != t2->info) { | |
5563 | bpf_log(log, "arg%d in %s() is %s while %s() has %s\n", | |
5564 | i, fn1, btf_type_str(t1), | |
5565 | fn2, btf_type_str(t2)); | |
5566 | return -EINVAL; | |
5567 | } | |
5568 | if (btf_type_has_size(t1) && t1->size != t2->size) { | |
5569 | bpf_log(log, | |
5570 | "arg%d in %s() has size %d while %s() has %d\n", | |
5571 | i, fn1, t1->size, | |
5572 | fn2, t2->size); | |
5573 | return -EINVAL; | |
5574 | } | |
5575 | ||
5576 | /* global functions are validated with scalars and pointers | |
5577 | * to context only. And only global functions can be replaced. | |
5578 | * Hence type check only those types. | |
5579 | */ | |
5580 | if (btf_type_is_int(t1) || btf_type_is_enum(t1)) | |
5581 | continue; | |
5582 | if (!btf_type_is_ptr(t1)) { | |
5583 | bpf_log(log, | |
5584 | "arg%d in %s() has unrecognized type\n", | |
5585 | i, fn1); | |
5586 | return -EINVAL; | |
5587 | } | |
5588 | t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); | |
5589 | t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); | |
5590 | if (!btf_type_is_struct(t1)) { | |
5591 | bpf_log(log, | |
5592 | "arg%d in %s() is not a pointer to context\n", | |
5593 | i, fn1); | |
5594 | return -EINVAL; | |
5595 | } | |
5596 | if (!btf_type_is_struct(t2)) { | |
5597 | bpf_log(log, | |
5598 | "arg%d in %s() is not a pointer to context\n", | |
5599 | i, fn2); | |
5600 | return -EINVAL; | |
5601 | } | |
5602 | /* This is an optional check to make program writing easier. | |
5603 | * Compare names of structs and report an error to the user. | |
5604 | * btf_prepare_func_args() already checked that t2 struct | |
5605 | * is a context type. btf_prepare_func_args() will check | |
5606 | * later that t1 struct is a context type as well. | |
5607 | */ | |
5608 | s1 = btf_name_by_offset(btf1, t1->name_off); | |
5609 | s2 = btf_name_by_offset(btf2, t2->name_off); | |
5610 | if (strcmp(s1, s2)) { | |
5611 | bpf_log(log, | |
5612 | "arg%d %s(struct %s *) doesn't match %s(struct %s *)\n", | |
5613 | i, fn1, s1, fn2, s2); | |
5614 | return -EINVAL; | |
5615 | } | |
5616 | } | |
5617 | return 0; | |
5618 | } | |
5619 | ||
5620 | /* Compare BTFs of given program with BTF of target program */ | |
efc68158 | 5621 | int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog, |
be8704ff AS |
5622 | struct btf *btf2, const struct btf_type *t2) |
5623 | { | |
5624 | struct btf *btf1 = prog->aux->btf; | |
5625 | const struct btf_type *t1; | |
5626 | u32 btf_id = 0; | |
5627 | ||
5628 | if (!prog->aux->func_info) { | |
efc68158 | 5629 | bpf_log(log, "Program extension requires BTF\n"); |
be8704ff AS |
5630 | return -EINVAL; |
5631 | } | |
5632 | ||
5633 | btf_id = prog->aux->func_info[0].type_id; | |
5634 | if (!btf_id) | |
5635 | return -EFAULT; | |
5636 | ||
5637 | t1 = btf_type_by_id(btf1, btf_id); | |
5638 | if (!t1 || !btf_type_is_func(t1)) | |
5639 | return -EFAULT; | |
5640 | ||
efc68158 | 5641 | return btf_check_func_type_match(log, btf1, t1, btf2, t2); |
be8704ff AS |
5642 | } |
5643 | ||
e6ac2450 MKL |
5644 | static u32 *reg2btf_ids[__BPF_REG_TYPE_MAX] = { |
5645 | #ifdef CONFIG_NET | |
5646 | [PTR_TO_SOCKET] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK], | |
5647 | [PTR_TO_SOCK_COMMON] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON], | |
5648 | [PTR_TO_TCP_SOCK] = &btf_sock_ids[BTF_SOCK_TYPE_TCP], | |
5649 | #endif | |
5650 | }; | |
5651 | ||
3363bd0c KKD |
5652 | /* Returns true if struct is composed of scalars, 4 levels of nesting allowed */ |
5653 | static bool __btf_type_is_scalar_struct(struct bpf_verifier_log *log, | |
5654 | const struct btf *btf, | |
5655 | const struct btf_type *t, int rec) | |
5656 | { | |
5657 | const struct btf_type *member_type; | |
5658 | const struct btf_member *member; | |
5659 | u32 i; | |
5660 | ||
5661 | if (!btf_type_is_struct(t)) | |
5662 | return false; | |
5663 | ||
5664 | for_each_member(i, t, member) { | |
5665 | const struct btf_array *array; | |
5666 | ||
5667 | member_type = btf_type_skip_modifiers(btf, member->type, NULL); | |
5668 | if (btf_type_is_struct(member_type)) { | |
5669 | if (rec >= 3) { | |
5670 | bpf_log(log, "max struct nesting depth exceeded\n"); | |
5671 | return false; | |
5672 | } | |
5673 | if (!__btf_type_is_scalar_struct(log, btf, member_type, rec + 1)) | |
5674 | return false; | |
5675 | continue; | |
5676 | } | |
5677 | if (btf_type_is_array(member_type)) { | |
5678 | array = btf_type_array(member_type); | |
5679 | if (!array->nelems) | |
5680 | return false; | |
5681 | member_type = btf_type_skip_modifiers(btf, array->type, NULL); | |
5682 | if (!btf_type_is_scalar(member_type)) | |
5683 | return false; | |
5684 | continue; | |
5685 | } | |
5686 | if (!btf_type_is_scalar(member_type)) | |
5687 | return false; | |
5688 | } | |
5689 | return true; | |
5690 | } | |
5691 | ||
d583691c KKD |
5692 | static bool is_kfunc_arg_mem_size(const struct btf *btf, |
5693 | const struct btf_param *arg, | |
5694 | const struct bpf_reg_state *reg) | |
5695 | { | |
5696 | int len, sfx_len = sizeof("__sz") - 1; | |
5697 | const struct btf_type *t; | |
5698 | const char *param_name; | |
5699 | ||
5700 | t = btf_type_skip_modifiers(btf, arg->type, NULL); | |
5701 | if (!btf_type_is_scalar(t) || reg->type != SCALAR_VALUE) | |
5702 | return false; | |
5703 | ||
5704 | /* In the future, this can be ported to use BTF tagging */ | |
5705 | param_name = btf_name_by_offset(btf, arg->name_off); | |
5706 | if (str_is_empty(param_name)) | |
5707 | return false; | |
5708 | len = strlen(param_name); | |
5709 | if (len < sfx_len) | |
5710 | return false; | |
5711 | param_name += len - sfx_len; | |
5712 | if (strncmp(param_name, "__sz", sfx_len)) | |
5713 | return false; | |
5714 | ||
5715 | return true; | |
5716 | } | |
5717 | ||
34747c41 MKL |
5718 | static int btf_check_func_arg_match(struct bpf_verifier_env *env, |
5719 | const struct btf *btf, u32 func_id, | |
5720 | struct bpf_reg_state *regs, | |
5721 | bool ptr_to_mem_ok) | |
8c1b6e69 | 5722 | { |
8c1b6e69 | 5723 | struct bpf_verifier_log *log = &env->log; |
5c073f26 | 5724 | u32 i, nargs, ref_id, ref_obj_id = 0; |
3363bd0c | 5725 | bool is_kfunc = btf_is_kernel(btf); |
34747c41 | 5726 | const char *func_name, *ref_tname; |
e5069b9c | 5727 | const struct btf_type *t, *ref_t; |
34747c41 | 5728 | const struct btf_param *args; |
5c073f26 KKD |
5729 | int ref_regno = 0; |
5730 | bool rel = false; | |
8c1b6e69 | 5731 | |
34747c41 | 5732 | t = btf_type_by_id(btf, func_id); |
8c1b6e69 | 5733 | if (!t || !btf_type_is_func(t)) { |
51c39bb1 | 5734 | /* These checks were already done by the verifier while loading |
e6ac2450 | 5735 | * struct bpf_func_info or in add_kfunc_call(). |
51c39bb1 | 5736 | */ |
34747c41 MKL |
5737 | bpf_log(log, "BTF of func_id %u doesn't point to KIND_FUNC\n", |
5738 | func_id); | |
51c39bb1 | 5739 | return -EFAULT; |
8c1b6e69 | 5740 | } |
34747c41 | 5741 | func_name = btf_name_by_offset(btf, t->name_off); |
8c1b6e69 AS |
5742 | |
5743 | t = btf_type_by_id(btf, t->type); | |
5744 | if (!t || !btf_type_is_func_proto(t)) { | |
34747c41 | 5745 | bpf_log(log, "Invalid BTF of func %s\n", func_name); |
51c39bb1 | 5746 | return -EFAULT; |
8c1b6e69 AS |
5747 | } |
5748 | args = (const struct btf_param *)(t + 1); | |
5749 | nargs = btf_type_vlen(t); | |
523a4cf4 | 5750 | if (nargs > MAX_BPF_FUNC_REG_ARGS) { |
34747c41 | 5751 | bpf_log(log, "Function %s has %d > %d args\n", func_name, nargs, |
523a4cf4 | 5752 | MAX_BPF_FUNC_REG_ARGS); |
34747c41 | 5753 | return -EINVAL; |
8c1b6e69 | 5754 | } |
e5069b9c | 5755 | |
8c1b6e69 AS |
5756 | /* check that BTF function arguments match actual types that the |
5757 | * verifier sees. | |
5758 | */ | |
5759 | for (i = 0; i < nargs; i++) { | |
34747c41 MKL |
5760 | u32 regno = i + 1; |
5761 | struct bpf_reg_state *reg = ®s[regno]; | |
feb4adfa | 5762 | |
34747c41 MKL |
5763 | t = btf_type_skip_modifiers(btf, args[i].type, NULL); |
5764 | if (btf_type_is_scalar(t)) { | |
feb4adfa | 5765 | if (reg->type == SCALAR_VALUE) |
8c1b6e69 | 5766 | continue; |
34747c41 MKL |
5767 | bpf_log(log, "R%d is not a scalar\n", regno); |
5768 | return -EINVAL; | |
8c1b6e69 | 5769 | } |
34747c41 MKL |
5770 | |
5771 | if (!btf_type_is_ptr(t)) { | |
5772 | bpf_log(log, "Unrecognized arg#%d type %s\n", | |
5773 | i, btf_type_str(t)); | |
5774 | return -EINVAL; | |
5775 | } | |
5776 | ||
e6ac2450 | 5777 | ref_t = btf_type_skip_modifiers(btf, t->type, &ref_id); |
34747c41 | 5778 | ref_tname = btf_name_by_offset(btf, ref_t->name_off); |
3363bd0c KKD |
5779 | if (btf_get_prog_ctx_type(log, btf, t, |
5780 | env->prog->type, i)) { | |
5781 | /* If function expects ctx type in BTF check that caller | |
5782 | * is passing PTR_TO_CTX. | |
5783 | */ | |
5784 | if (reg->type != PTR_TO_CTX) { | |
5785 | bpf_log(log, | |
5786 | "arg#%d expected pointer to ctx, but got %s\n", | |
5787 | i, btf_type_str(t)); | |
5788 | return -EINVAL; | |
5789 | } | |
be80a1d3 | 5790 | if (check_ptr_off_reg(env, reg, regno)) |
3363bd0c | 5791 | return -EINVAL; |
45ce4b4f KKD |
5792 | } else if (is_kfunc && (reg->type == PTR_TO_BTF_ID || |
5793 | (reg2btf_ids[base_type(reg->type)] && !type_flag(reg->type)))) { | |
e6ac2450 MKL |
5794 | const struct btf_type *reg_ref_t; |
5795 | const struct btf *reg_btf; | |
5796 | const char *reg_ref_tname; | |
5797 | u32 reg_ref_id; | |
5798 | ||
5799 | if (!btf_type_is_struct(ref_t)) { | |
5800 | bpf_log(log, "kernel function %s args#%d pointer type %s %s is not supported\n", | |
5801 | func_name, i, btf_type_str(ref_t), | |
5802 | ref_tname); | |
5803 | return -EINVAL; | |
5804 | } | |
5805 | ||
5806 | if (reg->type == PTR_TO_BTF_ID) { | |
5807 | reg_btf = reg->btf; | |
5808 | reg_ref_id = reg->btf_id; | |
5c073f26 KKD |
5809 | /* Ensure only one argument is referenced PTR_TO_BTF_ID */ |
5810 | if (reg->ref_obj_id) { | |
5811 | if (ref_obj_id) { | |
5812 | bpf_log(log, "verifier internal error: more than one arg with ref_obj_id R%d %u %u\n", | |
5813 | regno, reg->ref_obj_id, ref_obj_id); | |
5814 | return -EFAULT; | |
5815 | } | |
5816 | ref_regno = regno; | |
5817 | ref_obj_id = reg->ref_obj_id; | |
5818 | } | |
3363bd0c | 5819 | } else { |
e6ac2450 | 5820 | reg_btf = btf_vmlinux; |
45ce4b4f | 5821 | reg_ref_id = *reg2btf_ids[base_type(reg->type)]; |
e6ac2450 MKL |
5822 | } |
5823 | ||
5824 | reg_ref_t = btf_type_skip_modifiers(reg_btf, reg_ref_id, | |
5825 | ®_ref_id); | |
5826 | reg_ref_tname = btf_name_by_offset(reg_btf, | |
5827 | reg_ref_t->name_off); | |
5828 | if (!btf_struct_ids_match(log, reg_btf, reg_ref_id, | |
5829 | reg->off, btf, ref_id)) { | |
5830 | bpf_log(log, "kernel function %s args#%d expected pointer to %s %s but R%d has a pointer to %s %s\n", | |
5831 | func_name, i, | |
5832 | btf_type_str(ref_t), ref_tname, | |
5833 | regno, btf_type_str(reg_ref_t), | |
5834 | reg_ref_tname); | |
5835 | return -EINVAL; | |
5836 | } | |
34747c41 MKL |
5837 | } else if (ptr_to_mem_ok) { |
5838 | const struct btf_type *resolve_ret; | |
5839 | u32 type_size; | |
e5069b9c | 5840 | |
3363bd0c | 5841 | if (is_kfunc) { |
d583691c KKD |
5842 | bool arg_mem_size = i + 1 < nargs && is_kfunc_arg_mem_size(btf, &args[i + 1], ®s[regno + 1]); |
5843 | ||
3363bd0c KKD |
5844 | /* Permit pointer to mem, but only when argument |
5845 | * type is pointer to scalar, or struct composed | |
5846 | * (recursively) of scalars. | |
d583691c KKD |
5847 | * When arg_mem_size is true, the pointer can be |
5848 | * void *. | |
3363bd0c KKD |
5849 | */ |
5850 | if (!btf_type_is_scalar(ref_t) && | |
d583691c KKD |
5851 | !__btf_type_is_scalar_struct(log, btf, ref_t, 0) && |
5852 | (arg_mem_size ? !btf_type_is_void(ref_t) : 1)) { | |
3363bd0c | 5853 | bpf_log(log, |
d583691c KKD |
5854 | "arg#%d pointer type %s %s must point to %sscalar, or struct with scalar\n", |
5855 | i, btf_type_str(ref_t), ref_tname, arg_mem_size ? "void, " : ""); | |
3363bd0c KKD |
5856 | return -EINVAL; |
5857 | } | |
d583691c KKD |
5858 | |
5859 | /* Check for mem, len pair */ | |
5860 | if (arg_mem_size) { | |
5861 | if (check_kfunc_mem_size_reg(env, ®s[regno + 1], regno + 1)) { | |
5862 | bpf_log(log, "arg#%d arg#%d memory, len pair leads to invalid memory access\n", | |
5863 | i, i + 1); | |
5864 | return -EINVAL; | |
5865 | } | |
5866 | i++; | |
5867 | continue; | |
5868 | } | |
3363bd0c KKD |
5869 | } |
5870 | ||
34747c41 MKL |
5871 | resolve_ret = btf_resolve_size(btf, ref_t, &type_size); |
5872 | if (IS_ERR(resolve_ret)) { | |
e5069b9c | 5873 | bpf_log(log, |
34747c41 MKL |
5874 | "arg#%d reference type('%s %s') size cannot be determined: %ld\n", |
5875 | i, btf_type_str(ref_t), ref_tname, | |
5876 | PTR_ERR(resolve_ret)); | |
5877 | return -EINVAL; | |
e5069b9c DB |
5878 | } |
5879 | ||
34747c41 MKL |
5880 | if (check_mem_reg(env, reg, regno, type_size)) |
5881 | return -EINVAL; | |
5882 | } else { | |
3363bd0c KKD |
5883 | bpf_log(log, "reg type unsupported for arg#%d %sfunction %s#%d\n", i, |
5884 | is_kfunc ? "kernel " : "", func_name, func_id); | |
34747c41 | 5885 | return -EINVAL; |
8c1b6e69 | 5886 | } |
8c1b6e69 | 5887 | } |
34747c41 | 5888 | |
5c073f26 KKD |
5889 | /* Either both are set, or neither */ |
5890 | WARN_ON_ONCE((ref_obj_id && !ref_regno) || (!ref_obj_id && ref_regno)); | |
5891 | if (is_kfunc) { | |
5892 | rel = btf_kfunc_id_set_contains(btf, resolve_prog_type(env->prog), | |
5893 | BTF_KFUNC_TYPE_RELEASE, func_id); | |
5894 | /* We already made sure ref_obj_id is set only for one argument */ | |
5895 | if (rel && !ref_obj_id) { | |
5896 | bpf_log(log, "release kernel function %s expects refcounted PTR_TO_BTF_ID\n", | |
5897 | func_name); | |
5898 | return -EINVAL; | |
5899 | } | |
5900 | /* Allow (!rel && ref_obj_id), so that passing such referenced PTR_TO_BTF_ID to | |
5901 | * other kfuncs works | |
5902 | */ | |
5903 | } | |
5904 | /* returns argument register number > 0 in case of reference release kfunc */ | |
5905 | return rel ? ref_regno : 0; | |
34747c41 MKL |
5906 | } |
5907 | ||
5908 | /* Compare BTF of a function with given bpf_reg_state. | |
5909 | * Returns: | |
5910 | * EFAULT - there is a verifier bug. Abort verification. | |
5911 | * EINVAL - there is a type mismatch or BTF is not available. | |
5912 | * 0 - BTF matches with what bpf_reg_state expects. | |
5913 | * Only PTR_TO_CTX and SCALAR_VALUE states are recognized. | |
5914 | */ | |
5915 | int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog, | |
5916 | struct bpf_reg_state *regs) | |
5917 | { | |
5918 | struct bpf_prog *prog = env->prog; | |
5919 | struct btf *btf = prog->aux->btf; | |
5920 | bool is_global; | |
5921 | u32 btf_id; | |
5922 | int err; | |
5923 | ||
5924 | if (!prog->aux->func_info) | |
5925 | return -EINVAL; | |
5926 | ||
5927 | btf_id = prog->aux->func_info[subprog].type_id; | |
5928 | if (!btf_id) | |
5929 | return -EFAULT; | |
5930 | ||
5931 | if (prog->aux->func_info_aux[subprog].unreliable) | |
5932 | return -EINVAL; | |
5933 | ||
5934 | is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL; | |
5935 | err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global); | |
5936 | ||
51c39bb1 AS |
5937 | /* Compiler optimizations can remove arguments from static functions |
5938 | * or mismatched type can be passed into a global function. | |
5939 | * In such cases mark the function as unreliable from BTF point of view. | |
5940 | */ | |
34747c41 MKL |
5941 | if (err) |
5942 | prog->aux->func_info_aux[subprog].unreliable = true; | |
5943 | return err; | |
51c39bb1 AS |
5944 | } |
5945 | ||
e6ac2450 MKL |
5946 | int btf_check_kfunc_arg_match(struct bpf_verifier_env *env, |
5947 | const struct btf *btf, u32 func_id, | |
5948 | struct bpf_reg_state *regs) | |
5949 | { | |
3363bd0c | 5950 | return btf_check_func_arg_match(env, btf, func_id, regs, true); |
e6ac2450 MKL |
5951 | } |
5952 | ||
51c39bb1 AS |
5953 | /* Convert BTF of a function into bpf_reg_state if possible |
5954 | * Returns: | |
5955 | * EFAULT - there is a verifier bug. Abort verification. | |
5956 | * EINVAL - cannot convert BTF. | |
5957 | * 0 - Successfully converted BTF into bpf_reg_state | |
5958 | * (either PTR_TO_CTX or SCALAR_VALUE). | |
5959 | */ | |
5960 | int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog, | |
feb4adfa | 5961 | struct bpf_reg_state *regs) |
51c39bb1 AS |
5962 | { |
5963 | struct bpf_verifier_log *log = &env->log; | |
5964 | struct bpf_prog *prog = env->prog; | |
be8704ff | 5965 | enum bpf_prog_type prog_type = prog->type; |
51c39bb1 AS |
5966 | struct btf *btf = prog->aux->btf; |
5967 | const struct btf_param *args; | |
e5069b9c | 5968 | const struct btf_type *t, *ref_t; |
51c39bb1 AS |
5969 | u32 i, nargs, btf_id; |
5970 | const char *tname; | |
5971 | ||
5972 | if (!prog->aux->func_info || | |
5973 | prog->aux->func_info_aux[subprog].linkage != BTF_FUNC_GLOBAL) { | |
5974 | bpf_log(log, "Verifier bug\n"); | |
5975 | return -EFAULT; | |
5976 | } | |
5977 | ||
5978 | btf_id = prog->aux->func_info[subprog].type_id; | |
5979 | if (!btf_id) { | |
5980 | bpf_log(log, "Global functions need valid BTF\n"); | |
5981 | return -EFAULT; | |
5982 | } | |
5983 | ||
5984 | t = btf_type_by_id(btf, btf_id); | |
5985 | if (!t || !btf_type_is_func(t)) { | |
5986 | /* These checks were already done by the verifier while loading | |
5987 | * struct bpf_func_info | |
5988 | */ | |
5989 | bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n", | |
5990 | subprog); | |
5991 | return -EFAULT; | |
5992 | } | |
5993 | tname = btf_name_by_offset(btf, t->name_off); | |
5994 | ||
5995 | if (log->level & BPF_LOG_LEVEL) | |
5996 | bpf_log(log, "Validating %s() func#%d...\n", | |
5997 | tname, subprog); | |
5998 | ||
5999 | if (prog->aux->func_info_aux[subprog].unreliable) { | |
6000 | bpf_log(log, "Verifier bug in function %s()\n", tname); | |
6001 | return -EFAULT; | |
6002 | } | |
be8704ff | 6003 | if (prog_type == BPF_PROG_TYPE_EXT) |
3aac1ead | 6004 | prog_type = prog->aux->dst_prog->type; |
51c39bb1 AS |
6005 | |
6006 | t = btf_type_by_id(btf, t->type); | |
6007 | if (!t || !btf_type_is_func_proto(t)) { | |
6008 | bpf_log(log, "Invalid type of function %s()\n", tname); | |
6009 | return -EFAULT; | |
6010 | } | |
6011 | args = (const struct btf_param *)(t + 1); | |
6012 | nargs = btf_type_vlen(t); | |
523a4cf4 DB |
6013 | if (nargs > MAX_BPF_FUNC_REG_ARGS) { |
6014 | bpf_log(log, "Global function %s() with %d > %d args. Buggy compiler.\n", | |
6015 | tname, nargs, MAX_BPF_FUNC_REG_ARGS); | |
51c39bb1 AS |
6016 | return -EINVAL; |
6017 | } | |
6018 | /* check that function returns int */ | |
6019 | t = btf_type_by_id(btf, t->type); | |
6020 | while (btf_type_is_modifier(t)) | |
6021 | t = btf_type_by_id(btf, t->type); | |
6022 | if (!btf_type_is_int(t) && !btf_type_is_enum(t)) { | |
6023 | bpf_log(log, | |
6024 | "Global function %s() doesn't return scalar. Only those are supported.\n", | |
6025 | tname); | |
6026 | return -EINVAL; | |
6027 | } | |
6028 | /* Convert BTF function arguments into verifier types. | |
6029 | * Only PTR_TO_CTX and SCALAR are supported atm. | |
6030 | */ | |
6031 | for (i = 0; i < nargs; i++) { | |
feb4adfa DB |
6032 | struct bpf_reg_state *reg = ®s[i + 1]; |
6033 | ||
51c39bb1 AS |
6034 | t = btf_type_by_id(btf, args[i].type); |
6035 | while (btf_type_is_modifier(t)) | |
6036 | t = btf_type_by_id(btf, t->type); | |
6037 | if (btf_type_is_int(t) || btf_type_is_enum(t)) { | |
feb4adfa | 6038 | reg->type = SCALAR_VALUE; |
51c39bb1 AS |
6039 | continue; |
6040 | } | |
e5069b9c DB |
6041 | if (btf_type_is_ptr(t)) { |
6042 | if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) { | |
6043 | reg->type = PTR_TO_CTX; | |
6044 | continue; | |
6045 | } | |
6046 | ||
6047 | t = btf_type_skip_modifiers(btf, t->type, NULL); | |
6048 | ||
6049 | ref_t = btf_resolve_size(btf, t, ®->mem_size); | |
6050 | if (IS_ERR(ref_t)) { | |
6051 | bpf_log(log, | |
6052 | "arg#%d reference type('%s %s') size cannot be determined: %ld\n", | |
6053 | i, btf_type_str(t), btf_name_by_offset(btf, t->name_off), | |
6054 | PTR_ERR(ref_t)); | |
6055 | return -EINVAL; | |
6056 | } | |
6057 | ||
cf9f2f8d | 6058 | reg->type = PTR_TO_MEM | PTR_MAYBE_NULL; |
e5069b9c DB |
6059 | reg->id = ++env->id_gen; |
6060 | ||
51c39bb1 AS |
6061 | continue; |
6062 | } | |
6063 | bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n", | |
6064 | i, btf_kind_str[BTF_INFO_KIND(t->info)], tname); | |
6065 | return -EINVAL; | |
6066 | } | |
8c1b6e69 AS |
6067 | return 0; |
6068 | } | |
6069 | ||
31d0bc81 AM |
6070 | static void btf_type_show(const struct btf *btf, u32 type_id, void *obj, |
6071 | struct btf_show *show) | |
6072 | { | |
6073 | const struct btf_type *t = btf_type_by_id(btf, type_id); | |
6074 | ||
6075 | show->btf = btf; | |
6076 | memset(&show->state, 0, sizeof(show->state)); | |
6077 | memset(&show->obj, 0, sizeof(show->obj)); | |
6078 | ||
6079 | btf_type_ops(t)->show(btf, t, type_id, obj, 0, show); | |
6080 | } | |
6081 | ||
6082 | static void btf_seq_show(struct btf_show *show, const char *fmt, | |
6083 | va_list args) | |
6084 | { | |
6085 | seq_vprintf((struct seq_file *)show->target, fmt, args); | |
6086 | } | |
6087 | ||
eb411377 AM |
6088 | int btf_type_seq_show_flags(const struct btf *btf, u32 type_id, |
6089 | void *obj, struct seq_file *m, u64 flags) | |
31d0bc81 AM |
6090 | { |
6091 | struct btf_show sseq; | |
6092 | ||
6093 | sseq.target = m; | |
6094 | sseq.showfn = btf_seq_show; | |
6095 | sseq.flags = flags; | |
6096 | ||
6097 | btf_type_show(btf, type_id, obj, &sseq); | |
6098 | ||
6099 | return sseq.state.status; | |
6100 | } | |
6101 | ||
b00b8dae MKL |
6102 | void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj, |
6103 | struct seq_file *m) | |
6104 | { | |
31d0bc81 AM |
6105 | (void) btf_type_seq_show_flags(btf, type_id, obj, m, |
6106 | BTF_SHOW_NONAME | BTF_SHOW_COMPACT | | |
6107 | BTF_SHOW_ZERO | BTF_SHOW_UNSAFE); | |
6108 | } | |
6109 | ||
6110 | struct btf_show_snprintf { | |
6111 | struct btf_show show; | |
6112 | int len_left; /* space left in string */ | |
6113 | int len; /* length we would have written */ | |
6114 | }; | |
6115 | ||
6116 | static void btf_snprintf_show(struct btf_show *show, const char *fmt, | |
6117 | va_list args) | |
6118 | { | |
6119 | struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show; | |
6120 | int len; | |
6121 | ||
6122 | len = vsnprintf(show->target, ssnprintf->len_left, fmt, args); | |
6123 | ||
6124 | if (len < 0) { | |
6125 | ssnprintf->len_left = 0; | |
6126 | ssnprintf->len = len; | |
6127 | } else if (len > ssnprintf->len_left) { | |
6128 | /* no space, drive on to get length we would have written */ | |
6129 | ssnprintf->len_left = 0; | |
6130 | ssnprintf->len += len; | |
6131 | } else { | |
6132 | ssnprintf->len_left -= len; | |
6133 | ssnprintf->len += len; | |
6134 | show->target += len; | |
6135 | } | |
6136 | } | |
6137 | ||
6138 | int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj, | |
6139 | char *buf, int len, u64 flags) | |
6140 | { | |
6141 | struct btf_show_snprintf ssnprintf; | |
6142 | ||
6143 | ssnprintf.show.target = buf; | |
6144 | ssnprintf.show.flags = flags; | |
6145 | ssnprintf.show.showfn = btf_snprintf_show; | |
6146 | ssnprintf.len_left = len; | |
6147 | ssnprintf.len = 0; | |
6148 | ||
6149 | btf_type_show(btf, type_id, obj, (struct btf_show *)&ssnprintf); | |
6150 | ||
c561d110 | 6151 | /* If we encountered an error, return it. */ |
31d0bc81 AM |
6152 | if (ssnprintf.show.state.status) |
6153 | return ssnprintf.show.state.status; | |
b00b8dae | 6154 | |
31d0bc81 AM |
6155 | /* Otherwise return length we would have written */ |
6156 | return ssnprintf.len; | |
b00b8dae | 6157 | } |
f56a653c | 6158 | |
3481e64b QM |
6159 | #ifdef CONFIG_PROC_FS |
6160 | static void bpf_btf_show_fdinfo(struct seq_file *m, struct file *filp) | |
6161 | { | |
6162 | const struct btf *btf = filp->private_data; | |
6163 | ||
6164 | seq_printf(m, "btf_id:\t%u\n", btf->id); | |
6165 | } | |
6166 | #endif | |
6167 | ||
f56a653c MKL |
6168 | static int btf_release(struct inode *inode, struct file *filp) |
6169 | { | |
6170 | btf_put(filp->private_data); | |
6171 | return 0; | |
6172 | } | |
6173 | ||
60197cfb | 6174 | const struct file_operations btf_fops = { |
3481e64b QM |
6175 | #ifdef CONFIG_PROC_FS |
6176 | .show_fdinfo = bpf_btf_show_fdinfo, | |
6177 | #endif | |
f56a653c MKL |
6178 | .release = btf_release, |
6179 | }; | |
6180 | ||
78958fca MKL |
6181 | static int __btf_new_fd(struct btf *btf) |
6182 | { | |
6183 | return anon_inode_getfd("btf", &btf_fops, btf, O_RDONLY | O_CLOEXEC); | |
6184 | } | |
6185 | ||
c571bd75 | 6186 | int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr) |
f56a653c MKL |
6187 | { |
6188 | struct btf *btf; | |
78958fca | 6189 | int ret; |
f56a653c | 6190 | |
c571bd75 | 6191 | btf = btf_parse(make_bpfptr(attr->btf, uattr.is_kernel), |
f56a653c MKL |
6192 | attr->btf_size, attr->btf_log_level, |
6193 | u64_to_user_ptr(attr->btf_log_buf), | |
6194 | attr->btf_log_size); | |
6195 | if (IS_ERR(btf)) | |
6196 | return PTR_ERR(btf); | |
6197 | ||
78958fca MKL |
6198 | ret = btf_alloc_id(btf); |
6199 | if (ret) { | |
6200 | btf_free(btf); | |
6201 | return ret; | |
6202 | } | |
6203 | ||
6204 | /* | |
6205 | * The BTF ID is published to the userspace. | |
6206 | * All BTF free must go through call_rcu() from | |
6207 | * now on (i.e. free by calling btf_put()). | |
6208 | */ | |
6209 | ||
6210 | ret = __btf_new_fd(btf); | |
6211 | if (ret < 0) | |
f56a653c MKL |
6212 | btf_put(btf); |
6213 | ||
78958fca | 6214 | return ret; |
f56a653c MKL |
6215 | } |
6216 | ||
6217 | struct btf *btf_get_by_fd(int fd) | |
6218 | { | |
6219 | struct btf *btf; | |
6220 | struct fd f; | |
6221 | ||
6222 | f = fdget(fd); | |
6223 | ||
6224 | if (!f.file) | |
6225 | return ERR_PTR(-EBADF); | |
6226 | ||
6227 | if (f.file->f_op != &btf_fops) { | |
6228 | fdput(f); | |
6229 | return ERR_PTR(-EINVAL); | |
6230 | } | |
6231 | ||
6232 | btf = f.file->private_data; | |
78958fca | 6233 | refcount_inc(&btf->refcnt); |
f56a653c MKL |
6234 | fdput(f); |
6235 | ||
6236 | return btf; | |
6237 | } | |
60197cfb MKL |
6238 | |
6239 | int btf_get_info_by_fd(const struct btf *btf, | |
6240 | const union bpf_attr *attr, | |
6241 | union bpf_attr __user *uattr) | |
6242 | { | |
62dab84c | 6243 | struct bpf_btf_info __user *uinfo; |
5c6f2588 | 6244 | struct bpf_btf_info info; |
62dab84c MKL |
6245 | u32 info_copy, btf_copy; |
6246 | void __user *ubtf; | |
53297220 AN |
6247 | char __user *uname; |
6248 | u32 uinfo_len, uname_len, name_len; | |
6249 | int ret = 0; | |
60197cfb | 6250 | |
62dab84c MKL |
6251 | uinfo = u64_to_user_ptr(attr->info.info); |
6252 | uinfo_len = attr->info.info_len; | |
6253 | ||
6254 | info_copy = min_t(u32, uinfo_len, sizeof(info)); | |
5c6f2588 | 6255 | memset(&info, 0, sizeof(info)); |
62dab84c MKL |
6256 | if (copy_from_user(&info, uinfo, info_copy)) |
6257 | return -EFAULT; | |
6258 | ||
6259 | info.id = btf->id; | |
6260 | ubtf = u64_to_user_ptr(info.btf); | |
6261 | btf_copy = min_t(u32, btf->data_size, info.btf_size); | |
6262 | if (copy_to_user(ubtf, btf->data, btf_copy)) | |
6263 | return -EFAULT; | |
6264 | info.btf_size = btf->data_size; | |
6265 | ||
53297220 AN |
6266 | info.kernel_btf = btf->kernel_btf; |
6267 | ||
6268 | uname = u64_to_user_ptr(info.name); | |
6269 | uname_len = info.name_len; | |
6270 | if (!uname ^ !uname_len) | |
6271 | return -EINVAL; | |
6272 | ||
6273 | name_len = strlen(btf->name); | |
6274 | info.name_len = name_len; | |
6275 | ||
6276 | if (uname) { | |
6277 | if (uname_len >= name_len + 1) { | |
6278 | if (copy_to_user(uname, btf->name, name_len + 1)) | |
6279 | return -EFAULT; | |
6280 | } else { | |
6281 | char zero = '\0'; | |
6282 | ||
6283 | if (copy_to_user(uname, btf->name, uname_len - 1)) | |
6284 | return -EFAULT; | |
6285 | if (put_user(zero, uname + uname_len - 1)) | |
6286 | return -EFAULT; | |
6287 | /* let user-space know about too short buffer */ | |
6288 | ret = -ENOSPC; | |
6289 | } | |
6290 | } | |
6291 | ||
62dab84c MKL |
6292 | if (copy_to_user(uinfo, &info, info_copy) || |
6293 | put_user(info_copy, &uattr->info.info_len)) | |
60197cfb MKL |
6294 | return -EFAULT; |
6295 | ||
53297220 | 6296 | return ret; |
60197cfb | 6297 | } |
78958fca MKL |
6298 | |
6299 | int btf_get_fd_by_id(u32 id) | |
6300 | { | |
6301 | struct btf *btf; | |
6302 | int fd; | |
6303 | ||
6304 | rcu_read_lock(); | |
6305 | btf = idr_find(&btf_idr, id); | |
6306 | if (!btf || !refcount_inc_not_zero(&btf->refcnt)) | |
6307 | btf = ERR_PTR(-ENOENT); | |
6308 | rcu_read_unlock(); | |
6309 | ||
6310 | if (IS_ERR(btf)) | |
6311 | return PTR_ERR(btf); | |
6312 | ||
6313 | fd = __btf_new_fd(btf); | |
6314 | if (fd < 0) | |
6315 | btf_put(btf); | |
6316 | ||
6317 | return fd; | |
6318 | } | |
6319 | ||
22dc4a0f | 6320 | u32 btf_obj_id(const struct btf *btf) |
78958fca MKL |
6321 | { |
6322 | return btf->id; | |
6323 | } | |
eae2e83e | 6324 | |
290248a5 AN |
6325 | bool btf_is_kernel(const struct btf *btf) |
6326 | { | |
6327 | return btf->kernel_btf; | |
6328 | } | |
6329 | ||
541c3bad AN |
6330 | bool btf_is_module(const struct btf *btf) |
6331 | { | |
6332 | return btf->kernel_btf && strcmp(btf->name, "vmlinux") != 0; | |
6333 | } | |
6334 | ||
eae2e83e JO |
6335 | static int btf_id_cmp_func(const void *a, const void *b) |
6336 | { | |
6337 | const int *pa = a, *pb = b; | |
6338 | ||
6339 | return *pa - *pb; | |
6340 | } | |
6341 | ||
2af30f11 | 6342 | bool btf_id_set_contains(const struct btf_id_set *set, u32 id) |
eae2e83e JO |
6343 | { |
6344 | return bsearch(&id, set->ids, set->cnt, sizeof(u32), btf_id_cmp_func) != NULL; | |
6345 | } | |
36e68442 | 6346 | |
18688de2 KKD |
6347 | enum { |
6348 | BTF_MODULE_F_LIVE = (1 << 0), | |
6349 | }; | |
6350 | ||
36e68442 AN |
6351 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
6352 | struct btf_module { | |
6353 | struct list_head list; | |
6354 | struct module *module; | |
6355 | struct btf *btf; | |
6356 | struct bin_attribute *sysfs_attr; | |
18688de2 | 6357 | int flags; |
36e68442 AN |
6358 | }; |
6359 | ||
6360 | static LIST_HEAD(btf_modules); | |
6361 | static DEFINE_MUTEX(btf_module_mutex); | |
6362 | ||
6363 | static ssize_t | |
6364 | btf_module_read(struct file *file, struct kobject *kobj, | |
6365 | struct bin_attribute *bin_attr, | |
6366 | char *buf, loff_t off, size_t len) | |
6367 | { | |
6368 | const struct btf *btf = bin_attr->private; | |
6369 | ||
6370 | memcpy(buf, btf->data + off, len); | |
6371 | return len; | |
6372 | } | |
6373 | ||
1e89106d AS |
6374 | static void purge_cand_cache(struct btf *btf); |
6375 | ||
36e68442 AN |
6376 | static int btf_module_notify(struct notifier_block *nb, unsigned long op, |
6377 | void *module) | |
6378 | { | |
6379 | struct btf_module *btf_mod, *tmp; | |
6380 | struct module *mod = module; | |
6381 | struct btf *btf; | |
6382 | int err = 0; | |
6383 | ||
6384 | if (mod->btf_data_size == 0 || | |
18688de2 KKD |
6385 | (op != MODULE_STATE_COMING && op != MODULE_STATE_LIVE && |
6386 | op != MODULE_STATE_GOING)) | |
36e68442 AN |
6387 | goto out; |
6388 | ||
6389 | switch (op) { | |
6390 | case MODULE_STATE_COMING: | |
6391 | btf_mod = kzalloc(sizeof(*btf_mod), GFP_KERNEL); | |
6392 | if (!btf_mod) { | |
6393 | err = -ENOMEM; | |
6394 | goto out; | |
6395 | } | |
6396 | btf = btf_parse_module(mod->name, mod->btf_data, mod->btf_data_size); | |
6397 | if (IS_ERR(btf)) { | |
6398 | pr_warn("failed to validate module [%s] BTF: %ld\n", | |
6399 | mod->name, PTR_ERR(btf)); | |
6400 | kfree(btf_mod); | |
6401 | err = PTR_ERR(btf); | |
6402 | goto out; | |
6403 | } | |
6404 | err = btf_alloc_id(btf); | |
6405 | if (err) { | |
6406 | btf_free(btf); | |
6407 | kfree(btf_mod); | |
6408 | goto out; | |
6409 | } | |
6410 | ||
1e89106d | 6411 | purge_cand_cache(NULL); |
36e68442 AN |
6412 | mutex_lock(&btf_module_mutex); |
6413 | btf_mod->module = module; | |
6414 | btf_mod->btf = btf; | |
6415 | list_add(&btf_mod->list, &btf_modules); | |
6416 | mutex_unlock(&btf_module_mutex); | |
6417 | ||
6418 | if (IS_ENABLED(CONFIG_SYSFS)) { | |
6419 | struct bin_attribute *attr; | |
6420 | ||
6421 | attr = kzalloc(sizeof(*attr), GFP_KERNEL); | |
6422 | if (!attr) | |
6423 | goto out; | |
6424 | ||
6425 | sysfs_bin_attr_init(attr); | |
6426 | attr->attr.name = btf->name; | |
6427 | attr->attr.mode = 0444; | |
6428 | attr->size = btf->data_size; | |
6429 | attr->private = btf; | |
6430 | attr->read = btf_module_read; | |
6431 | ||
6432 | err = sysfs_create_bin_file(btf_kobj, attr); | |
6433 | if (err) { | |
6434 | pr_warn("failed to register module [%s] BTF in sysfs: %d\n", | |
6435 | mod->name, err); | |
6436 | kfree(attr); | |
6437 | err = 0; | |
6438 | goto out; | |
6439 | } | |
6440 | ||
6441 | btf_mod->sysfs_attr = attr; | |
6442 | } | |
6443 | ||
18688de2 KKD |
6444 | break; |
6445 | case MODULE_STATE_LIVE: | |
6446 | mutex_lock(&btf_module_mutex); | |
6447 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
6448 | if (btf_mod->module != module) | |
6449 | continue; | |
6450 | ||
6451 | btf_mod->flags |= BTF_MODULE_F_LIVE; | |
6452 | break; | |
6453 | } | |
6454 | mutex_unlock(&btf_module_mutex); | |
36e68442 AN |
6455 | break; |
6456 | case MODULE_STATE_GOING: | |
6457 | mutex_lock(&btf_module_mutex); | |
6458 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
6459 | if (btf_mod->module != module) | |
6460 | continue; | |
6461 | ||
6462 | list_del(&btf_mod->list); | |
6463 | if (btf_mod->sysfs_attr) | |
6464 | sysfs_remove_bin_file(btf_kobj, btf_mod->sysfs_attr); | |
1e89106d | 6465 | purge_cand_cache(btf_mod->btf); |
36e68442 AN |
6466 | btf_put(btf_mod->btf); |
6467 | kfree(btf_mod->sysfs_attr); | |
6468 | kfree(btf_mod); | |
6469 | break; | |
6470 | } | |
6471 | mutex_unlock(&btf_module_mutex); | |
6472 | break; | |
6473 | } | |
6474 | out: | |
6475 | return notifier_from_errno(err); | |
6476 | } | |
6477 | ||
6478 | static struct notifier_block btf_module_nb = { | |
6479 | .notifier_call = btf_module_notify, | |
6480 | }; | |
6481 | ||
6482 | static int __init btf_module_init(void) | |
6483 | { | |
6484 | register_module_notifier(&btf_module_nb); | |
6485 | return 0; | |
6486 | } | |
6487 | ||
6488 | fs_initcall(btf_module_init); | |
6489 | #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */ | |
541c3bad AN |
6490 | |
6491 | struct module *btf_try_get_module(const struct btf *btf) | |
6492 | { | |
6493 | struct module *res = NULL; | |
6494 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES | |
6495 | struct btf_module *btf_mod, *tmp; | |
6496 | ||
6497 | mutex_lock(&btf_module_mutex); | |
6498 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
6499 | if (btf_mod->btf != btf) | |
6500 | continue; | |
6501 | ||
18688de2 KKD |
6502 | /* We must only consider module whose __init routine has |
6503 | * finished, hence we must check for BTF_MODULE_F_LIVE flag, | |
6504 | * which is set from the notifier callback for | |
6505 | * MODULE_STATE_LIVE. | |
6506 | */ | |
6507 | if ((btf_mod->flags & BTF_MODULE_F_LIVE) && try_module_get(btf_mod->module)) | |
541c3bad AN |
6508 | res = btf_mod->module; |
6509 | ||
6510 | break; | |
6511 | } | |
6512 | mutex_unlock(&btf_module_mutex); | |
6513 | #endif | |
6514 | ||
6515 | return res; | |
6516 | } | |
3d78417b | 6517 | |
dee872e1 KKD |
6518 | /* Returns struct btf corresponding to the struct module |
6519 | * | |
6520 | * This function can return NULL or ERR_PTR. Note that caller must | |
6521 | * release reference for struct btf iff btf_is_module is true. | |
6522 | */ | |
6523 | static struct btf *btf_get_module_btf(const struct module *module) | |
6524 | { | |
6525 | struct btf *btf = NULL; | |
6526 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES | |
6527 | struct btf_module *btf_mod, *tmp; | |
6528 | #endif | |
6529 | ||
6530 | if (!module) | |
6531 | return bpf_get_btf_vmlinux(); | |
6532 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES | |
6533 | mutex_lock(&btf_module_mutex); | |
6534 | list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { | |
6535 | if (btf_mod->module != module) | |
6536 | continue; | |
6537 | ||
6538 | btf_get(btf_mod->btf); | |
6539 | btf = btf_mod->btf; | |
6540 | break; | |
6541 | } | |
6542 | mutex_unlock(&btf_module_mutex); | |
6543 | #endif | |
6544 | ||
6545 | return btf; | |
6546 | } | |
6547 | ||
3d78417b AS |
6548 | BPF_CALL_4(bpf_btf_find_by_name_kind, char *, name, int, name_sz, u32, kind, int, flags) |
6549 | { | |
6550 | struct btf *btf; | |
6551 | long ret; | |
6552 | ||
6553 | if (flags) | |
6554 | return -EINVAL; | |
6555 | ||
6556 | if (name_sz <= 1 || name[name_sz - 1]) | |
6557 | return -EINVAL; | |
6558 | ||
6559 | btf = bpf_get_btf_vmlinux(); | |
6560 | if (IS_ERR(btf)) | |
6561 | return PTR_ERR(btf); | |
6562 | ||
6563 | ret = btf_find_by_name_kind(btf, name, kind); | |
6564 | /* ret is never zero, since btf_find_by_name_kind returns | |
6565 | * positive btf_id or negative error. | |
6566 | */ | |
6567 | if (ret < 0) { | |
6568 | struct btf *mod_btf; | |
6569 | int id; | |
6570 | ||
6571 | /* If name is not found in vmlinux's BTF then search in module's BTFs */ | |
6572 | spin_lock_bh(&btf_idr_lock); | |
6573 | idr_for_each_entry(&btf_idr, mod_btf, id) { | |
6574 | if (!btf_is_module(mod_btf)) | |
6575 | continue; | |
6576 | /* linear search could be slow hence unlock/lock | |
6577 | * the IDR to avoiding holding it for too long | |
6578 | */ | |
6579 | btf_get(mod_btf); | |
6580 | spin_unlock_bh(&btf_idr_lock); | |
6581 | ret = btf_find_by_name_kind(mod_btf, name, kind); | |
6582 | if (ret > 0) { | |
6583 | int btf_obj_fd; | |
6584 | ||
6585 | btf_obj_fd = __btf_new_fd(mod_btf); | |
6586 | if (btf_obj_fd < 0) { | |
6587 | btf_put(mod_btf); | |
6588 | return btf_obj_fd; | |
6589 | } | |
6590 | return ret | (((u64)btf_obj_fd) << 32); | |
6591 | } | |
6592 | spin_lock_bh(&btf_idr_lock); | |
6593 | btf_put(mod_btf); | |
6594 | } | |
6595 | spin_unlock_bh(&btf_idr_lock); | |
6596 | } | |
6597 | return ret; | |
6598 | } | |
6599 | ||
6600 | const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = { | |
6601 | .func = bpf_btf_find_by_name_kind, | |
6602 | .gpl_only = false, | |
6603 | .ret_type = RET_INTEGER, | |
216e3cd2 | 6604 | .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
3d78417b AS |
6605 | .arg2_type = ARG_CONST_SIZE, |
6606 | .arg3_type = ARG_ANYTHING, | |
6607 | .arg4_type = ARG_ANYTHING, | |
6608 | }; | |
eb529c5b | 6609 | |
d19ddb47 SL |
6610 | BTF_ID_LIST_GLOBAL(btf_tracing_ids, MAX_BTF_TRACING_TYPE) |
6611 | #define BTF_TRACING_TYPE(name, type) BTF_ID(struct, type) | |
6612 | BTF_TRACING_TYPE_xxx | |
6613 | #undef BTF_TRACING_TYPE | |
14f267d9 | 6614 | |
dee872e1 | 6615 | /* Kernel Function (kfunc) BTF ID set registration API */ |
14f267d9 | 6616 | |
dee872e1 KKD |
6617 | static int __btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, |
6618 | enum btf_kfunc_type type, | |
6619 | struct btf_id_set *add_set, bool vmlinux_set) | |
14f267d9 | 6620 | { |
dee872e1 KKD |
6621 | struct btf_kfunc_set_tab *tab; |
6622 | struct btf_id_set *set; | |
6623 | u32 set_cnt; | |
6624 | int ret; | |
6625 | ||
6626 | if (hook >= BTF_KFUNC_HOOK_MAX || type >= BTF_KFUNC_TYPE_MAX) { | |
6627 | ret = -EINVAL; | |
6628 | goto end; | |
6629 | } | |
6630 | ||
6631 | if (!add_set->cnt) | |
6632 | return 0; | |
6633 | ||
6634 | tab = btf->kfunc_set_tab; | |
6635 | if (!tab) { | |
6636 | tab = kzalloc(sizeof(*tab), GFP_KERNEL | __GFP_NOWARN); | |
6637 | if (!tab) | |
6638 | return -ENOMEM; | |
6639 | btf->kfunc_set_tab = tab; | |
6640 | } | |
6641 | ||
6642 | set = tab->sets[hook][type]; | |
6643 | /* Warn when register_btf_kfunc_id_set is called twice for the same hook | |
6644 | * for module sets. | |
6645 | */ | |
6646 | if (WARN_ON_ONCE(set && !vmlinux_set)) { | |
6647 | ret = -EINVAL; | |
6648 | goto end; | |
6649 | } | |
6650 | ||
6651 | /* We don't need to allocate, concatenate, and sort module sets, because | |
6652 | * only one is allowed per hook. Hence, we can directly assign the | |
6653 | * pointer and return. | |
6654 | */ | |
6655 | if (!vmlinux_set) { | |
6656 | tab->sets[hook][type] = add_set; | |
6657 | return 0; | |
6658 | } | |
6659 | ||
6660 | /* In case of vmlinux sets, there may be more than one set being | |
6661 | * registered per hook. To create a unified set, we allocate a new set | |
6662 | * and concatenate all individual sets being registered. While each set | |
6663 | * is individually sorted, they may become unsorted when concatenated, | |
6664 | * hence re-sorting the final set again is required to make binary | |
6665 | * searching the set using btf_id_set_contains function work. | |
6666 | */ | |
6667 | set_cnt = set ? set->cnt : 0; | |
6668 | ||
6669 | if (set_cnt > U32_MAX - add_set->cnt) { | |
6670 | ret = -EOVERFLOW; | |
6671 | goto end; | |
6672 | } | |
6673 | ||
6674 | if (set_cnt + add_set->cnt > BTF_KFUNC_SET_MAX_CNT) { | |
6675 | ret = -E2BIG; | |
6676 | goto end; | |
6677 | } | |
6678 | ||
6679 | /* Grow set */ | |
6680 | set = krealloc(tab->sets[hook][type], | |
6681 | offsetof(struct btf_id_set, ids[set_cnt + add_set->cnt]), | |
6682 | GFP_KERNEL | __GFP_NOWARN); | |
6683 | if (!set) { | |
6684 | ret = -ENOMEM; | |
6685 | goto end; | |
6686 | } | |
6687 | ||
6688 | /* For newly allocated set, initialize set->cnt to 0 */ | |
6689 | if (!tab->sets[hook][type]) | |
6690 | set->cnt = 0; | |
6691 | tab->sets[hook][type] = set; | |
6692 | ||
6693 | /* Concatenate the two sets */ | |
6694 | memcpy(set->ids + set->cnt, add_set->ids, add_set->cnt * sizeof(set->ids[0])); | |
6695 | set->cnt += add_set->cnt; | |
6696 | ||
6697 | sort(set->ids, set->cnt, sizeof(set->ids[0]), btf_id_cmp_func, NULL); | |
6698 | ||
6699 | return 0; | |
6700 | end: | |
6701 | btf_free_kfunc_set_tab(btf); | |
6702 | return ret; | |
14f267d9 | 6703 | } |
14f267d9 | 6704 | |
dee872e1 KKD |
6705 | static int btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, |
6706 | const struct btf_kfunc_id_set *kset) | |
14f267d9 | 6707 | { |
dee872e1 | 6708 | bool vmlinux_set = !btf_is_module(btf); |
d0b38229 | 6709 | int type, ret = 0; |
dee872e1 KKD |
6710 | |
6711 | for (type = 0; type < ARRAY_SIZE(kset->sets); type++) { | |
6712 | if (!kset->sets[type]) | |
6713 | continue; | |
6714 | ||
6715 | ret = __btf_populate_kfunc_set(btf, hook, type, kset->sets[type], vmlinux_set); | |
6716 | if (ret) | |
6717 | break; | |
6718 | } | |
6719 | return ret; | |
14f267d9 | 6720 | } |
14f267d9 | 6721 | |
dee872e1 KKD |
6722 | static bool __btf_kfunc_id_set_contains(const struct btf *btf, |
6723 | enum btf_kfunc_hook hook, | |
6724 | enum btf_kfunc_type type, | |
6725 | u32 kfunc_btf_id) | |
14f267d9 | 6726 | { |
dee872e1 | 6727 | struct btf_id_set *set; |
14f267d9 | 6728 | |
dee872e1 KKD |
6729 | if (hook >= BTF_KFUNC_HOOK_MAX || type >= BTF_KFUNC_TYPE_MAX) |
6730 | return false; | |
6731 | if (!btf->kfunc_set_tab) | |
6732 | return false; | |
6733 | set = btf->kfunc_set_tab->sets[hook][type]; | |
6734 | if (!set) | |
6735 | return false; | |
6736 | return btf_id_set_contains(set, kfunc_btf_id); | |
6737 | } | |
6738 | ||
6739 | static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type) | |
6740 | { | |
6741 | switch (prog_type) { | |
6742 | case BPF_PROG_TYPE_XDP: | |
6743 | return BTF_KFUNC_HOOK_XDP; | |
6744 | case BPF_PROG_TYPE_SCHED_CLS: | |
6745 | return BTF_KFUNC_HOOK_TC; | |
6746 | case BPF_PROG_TYPE_STRUCT_OPS: | |
6747 | return BTF_KFUNC_HOOK_STRUCT_OPS; | |
6748 | default: | |
6749 | return BTF_KFUNC_HOOK_MAX; | |
14f267d9 | 6750 | } |
14f267d9 KKD |
6751 | } |
6752 | ||
dee872e1 KKD |
6753 | /* Caution: |
6754 | * Reference to the module (obtained using btf_try_get_module) corresponding to | |
6755 | * the struct btf *MUST* be held when calling this function from verifier | |
6756 | * context. This is usually true as we stash references in prog's kfunc_btf_tab; | |
6757 | * keeping the reference for the duration of the call provides the necessary | |
6758 | * protection for looking up a well-formed btf->kfunc_set_tab. | |
6759 | */ | |
6760 | bool btf_kfunc_id_set_contains(const struct btf *btf, | |
6761 | enum bpf_prog_type prog_type, | |
6762 | enum btf_kfunc_type type, u32 kfunc_btf_id) | |
6763 | { | |
6764 | enum btf_kfunc_hook hook; | |
0e32dfc8 | 6765 | |
dee872e1 KKD |
6766 | hook = bpf_prog_type_to_kfunc_hook(prog_type); |
6767 | return __btf_kfunc_id_set_contains(btf, hook, type, kfunc_btf_id); | |
6768 | } | |
d9847eb8 | 6769 | |
dee872e1 KKD |
6770 | /* This function must be invoked only from initcalls/module init functions */ |
6771 | int register_btf_kfunc_id_set(enum bpf_prog_type prog_type, | |
6772 | const struct btf_kfunc_id_set *kset) | |
6773 | { | |
6774 | enum btf_kfunc_hook hook; | |
6775 | struct btf *btf; | |
6776 | int ret; | |
6777 | ||
6778 | btf = btf_get_module_btf(kset->owner); | |
c446fdac SF |
6779 | if (!btf) { |
6780 | if (!kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) { | |
6781 | pr_err("missing vmlinux BTF, cannot register kfuncs\n"); | |
6782 | return -ENOENT; | |
6783 | } | |
6784 | if (kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) { | |
6785 | pr_err("missing module BTF, cannot register kfuncs\n"); | |
6786 | return -ENOENT; | |
6787 | } | |
6788 | return 0; | |
6789 | } | |
6790 | if (IS_ERR(btf)) | |
6791 | return PTR_ERR(btf); | |
dee872e1 KKD |
6792 | |
6793 | hook = bpf_prog_type_to_kfunc_hook(prog_type); | |
6794 | ret = btf_populate_kfunc_set(btf, hook, kset); | |
6795 | /* reference is only taken for module BTF */ | |
6796 | if (btf_is_module(btf)) | |
6797 | btf_put(btf); | |
6798 | return ret; | |
6799 | } | |
6800 | EXPORT_SYMBOL_GPL(register_btf_kfunc_id_set); | |
be315829 | 6801 | |
e70e13e7 MC |
6802 | #define MAX_TYPES_ARE_COMPAT_DEPTH 2 |
6803 | ||
6804 | static | |
6805 | int __bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, | |
6806 | const struct btf *targ_btf, __u32 targ_id, | |
6807 | int level) | |
6808 | { | |
6809 | const struct btf_type *local_type, *targ_type; | |
6810 | int depth = 32; /* max recursion depth */ | |
6811 | ||
6812 | /* caller made sure that names match (ignoring flavor suffix) */ | |
6813 | local_type = btf_type_by_id(local_btf, local_id); | |
6814 | targ_type = btf_type_by_id(targ_btf, targ_id); | |
6815 | if (btf_kind(local_type) != btf_kind(targ_type)) | |
6816 | return 0; | |
6817 | ||
6818 | recur: | |
6819 | depth--; | |
6820 | if (depth < 0) | |
6821 | return -EINVAL; | |
6822 | ||
6823 | local_type = btf_type_skip_modifiers(local_btf, local_id, &local_id); | |
6824 | targ_type = btf_type_skip_modifiers(targ_btf, targ_id, &targ_id); | |
6825 | if (!local_type || !targ_type) | |
6826 | return -EINVAL; | |
6827 | ||
6828 | if (btf_kind(local_type) != btf_kind(targ_type)) | |
6829 | return 0; | |
6830 | ||
6831 | switch (btf_kind(local_type)) { | |
6832 | case BTF_KIND_UNKN: | |
6833 | case BTF_KIND_STRUCT: | |
6834 | case BTF_KIND_UNION: | |
6835 | case BTF_KIND_ENUM: | |
6836 | case BTF_KIND_FWD: | |
6837 | return 1; | |
6838 | case BTF_KIND_INT: | |
6839 | /* just reject deprecated bitfield-like integers; all other | |
6840 | * integers are by default compatible between each other | |
6841 | */ | |
6842 | return btf_int_offset(local_type) == 0 && btf_int_offset(targ_type) == 0; | |
6843 | case BTF_KIND_PTR: | |
6844 | local_id = local_type->type; | |
6845 | targ_id = targ_type->type; | |
6846 | goto recur; | |
6847 | case BTF_KIND_ARRAY: | |
6848 | local_id = btf_array(local_type)->type; | |
6849 | targ_id = btf_array(targ_type)->type; | |
6850 | goto recur; | |
6851 | case BTF_KIND_FUNC_PROTO: { | |
6852 | struct btf_param *local_p = btf_params(local_type); | |
6853 | struct btf_param *targ_p = btf_params(targ_type); | |
6854 | __u16 local_vlen = btf_vlen(local_type); | |
6855 | __u16 targ_vlen = btf_vlen(targ_type); | |
6856 | int i, err; | |
6857 | ||
6858 | if (local_vlen != targ_vlen) | |
6859 | return 0; | |
6860 | ||
6861 | for (i = 0; i < local_vlen; i++, local_p++, targ_p++) { | |
6862 | if (level <= 0) | |
6863 | return -EINVAL; | |
6864 | ||
6865 | btf_type_skip_modifiers(local_btf, local_p->type, &local_id); | |
6866 | btf_type_skip_modifiers(targ_btf, targ_p->type, &targ_id); | |
6867 | err = __bpf_core_types_are_compat(local_btf, local_id, | |
6868 | targ_btf, targ_id, | |
6869 | level - 1); | |
6870 | if (err <= 0) | |
6871 | return err; | |
6872 | } | |
6873 | ||
6874 | /* tail recurse for return type check */ | |
6875 | btf_type_skip_modifiers(local_btf, local_type->type, &local_id); | |
6876 | btf_type_skip_modifiers(targ_btf, targ_type->type, &targ_id); | |
6877 | goto recur; | |
6878 | } | |
6879 | default: | |
6880 | return 0; | |
6881 | } | |
6882 | } | |
6883 | ||
6884 | /* Check local and target types for compatibility. This check is used for | |
6885 | * type-based CO-RE relocations and follow slightly different rules than | |
6886 | * field-based relocations. This function assumes that root types were already | |
6887 | * checked for name match. Beyond that initial root-level name check, names | |
6888 | * are completely ignored. Compatibility rules are as follows: | |
6889 | * - any two STRUCTs/UNIONs/FWDs/ENUMs/INTs are considered compatible, but | |
6890 | * kind should match for local and target types (i.e., STRUCT is not | |
6891 | * compatible with UNION); | |
6892 | * - for ENUMs, the size is ignored; | |
6893 | * - for INT, size and signedness are ignored; | |
6894 | * - for ARRAY, dimensionality is ignored, element types are checked for | |
6895 | * compatibility recursively; | |
6896 | * - CONST/VOLATILE/RESTRICT modifiers are ignored; | |
6897 | * - TYPEDEFs/PTRs are compatible if types they pointing to are compatible; | |
6898 | * - FUNC_PROTOs are compatible if they have compatible signature: same | |
6899 | * number of input args and compatible return and argument types. | |
6900 | * These rules are not set in stone and probably will be adjusted as we get | |
6901 | * more experience with using BPF CO-RE relocations. | |
6902 | */ | |
29db4bea AS |
6903 | int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, |
6904 | const struct btf *targ_btf, __u32 targ_id) | |
6905 | { | |
e70e13e7 MC |
6906 | return __bpf_core_types_are_compat(local_btf, local_id, |
6907 | targ_btf, targ_id, | |
6908 | MAX_TYPES_ARE_COMPAT_DEPTH); | |
29db4bea AS |
6909 | } |
6910 | ||
6911 | static bool bpf_core_is_flavor_sep(const char *s) | |
6912 | { | |
6913 | /* check X___Y name pattern, where X and Y are not underscores */ | |
6914 | return s[0] != '_' && /* X */ | |
6915 | s[1] == '_' && s[2] == '_' && s[3] == '_' && /* ___ */ | |
6916 | s[4] != '_'; /* Y */ | |
6917 | } | |
6918 | ||
6919 | size_t bpf_core_essential_name_len(const char *name) | |
6920 | { | |
6921 | size_t n = strlen(name); | |
6922 | int i; | |
6923 | ||
6924 | for (i = n - 5; i >= 0; i--) { | |
6925 | if (bpf_core_is_flavor_sep(name + i)) | |
6926 | return i + 1; | |
6927 | } | |
6928 | return n; | |
6929 | } | |
fbd94c7a | 6930 | |
1e89106d AS |
6931 | struct bpf_cand_cache { |
6932 | const char *name; | |
6933 | u32 name_len; | |
6934 | u16 kind; | |
6935 | u16 cnt; | |
6936 | struct { | |
6937 | const struct btf *btf; | |
6938 | u32 id; | |
6939 | } cands[]; | |
6940 | }; | |
6941 | ||
6942 | static void bpf_free_cands(struct bpf_cand_cache *cands) | |
6943 | { | |
6944 | if (!cands->cnt) | |
6945 | /* empty candidate array was allocated on stack */ | |
6946 | return; | |
6947 | kfree(cands); | |
6948 | } | |
6949 | ||
6950 | static void bpf_free_cands_from_cache(struct bpf_cand_cache *cands) | |
6951 | { | |
6952 | kfree(cands->name); | |
6953 | kfree(cands); | |
6954 | } | |
6955 | ||
6956 | #define VMLINUX_CAND_CACHE_SIZE 31 | |
6957 | static struct bpf_cand_cache *vmlinux_cand_cache[VMLINUX_CAND_CACHE_SIZE]; | |
6958 | ||
6959 | #define MODULE_CAND_CACHE_SIZE 31 | |
6960 | static struct bpf_cand_cache *module_cand_cache[MODULE_CAND_CACHE_SIZE]; | |
6961 | ||
6962 | static DEFINE_MUTEX(cand_cache_mutex); | |
6963 | ||
6964 | static void __print_cand_cache(struct bpf_verifier_log *log, | |
6965 | struct bpf_cand_cache **cache, | |
6966 | int cache_size) | |
6967 | { | |
6968 | struct bpf_cand_cache *cc; | |
6969 | int i, j; | |
6970 | ||
6971 | for (i = 0; i < cache_size; i++) { | |
6972 | cc = cache[i]; | |
6973 | if (!cc) | |
6974 | continue; | |
6975 | bpf_log(log, "[%d]%s(", i, cc->name); | |
6976 | for (j = 0; j < cc->cnt; j++) { | |
6977 | bpf_log(log, "%d", cc->cands[j].id); | |
6978 | if (j < cc->cnt - 1) | |
6979 | bpf_log(log, " "); | |
6980 | } | |
6981 | bpf_log(log, "), "); | |
6982 | } | |
6983 | } | |
6984 | ||
6985 | static void print_cand_cache(struct bpf_verifier_log *log) | |
6986 | { | |
6987 | mutex_lock(&cand_cache_mutex); | |
6988 | bpf_log(log, "vmlinux_cand_cache:"); | |
6989 | __print_cand_cache(log, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); | |
6990 | bpf_log(log, "\nmodule_cand_cache:"); | |
6991 | __print_cand_cache(log, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
6992 | bpf_log(log, "\n"); | |
6993 | mutex_unlock(&cand_cache_mutex); | |
6994 | } | |
6995 | ||
6996 | static u32 hash_cands(struct bpf_cand_cache *cands) | |
6997 | { | |
6998 | return jhash(cands->name, cands->name_len, 0); | |
6999 | } | |
7000 | ||
7001 | static struct bpf_cand_cache *check_cand_cache(struct bpf_cand_cache *cands, | |
7002 | struct bpf_cand_cache **cache, | |
7003 | int cache_size) | |
7004 | { | |
7005 | struct bpf_cand_cache *cc = cache[hash_cands(cands) % cache_size]; | |
7006 | ||
7007 | if (cc && cc->name_len == cands->name_len && | |
7008 | !strncmp(cc->name, cands->name, cands->name_len)) | |
7009 | return cc; | |
7010 | return NULL; | |
7011 | } | |
7012 | ||
7013 | static size_t sizeof_cands(int cnt) | |
7014 | { | |
7015 | return offsetof(struct bpf_cand_cache, cands[cnt]); | |
7016 | } | |
7017 | ||
7018 | static struct bpf_cand_cache *populate_cand_cache(struct bpf_cand_cache *cands, | |
7019 | struct bpf_cand_cache **cache, | |
7020 | int cache_size) | |
7021 | { | |
7022 | struct bpf_cand_cache **cc = &cache[hash_cands(cands) % cache_size], *new_cands; | |
7023 | ||
7024 | if (*cc) { | |
7025 | bpf_free_cands_from_cache(*cc); | |
7026 | *cc = NULL; | |
7027 | } | |
4674f210 | 7028 | new_cands = kmemdup(cands, sizeof_cands(cands->cnt), GFP_KERNEL); |
1e89106d AS |
7029 | if (!new_cands) { |
7030 | bpf_free_cands(cands); | |
7031 | return ERR_PTR(-ENOMEM); | |
7032 | } | |
1e89106d AS |
7033 | /* strdup the name, since it will stay in cache. |
7034 | * the cands->name points to strings in prog's BTF and the prog can be unloaded. | |
7035 | */ | |
7036 | new_cands->name = kmemdup_nul(cands->name, cands->name_len, GFP_KERNEL); | |
7037 | bpf_free_cands(cands); | |
7038 | if (!new_cands->name) { | |
7039 | kfree(new_cands); | |
7040 | return ERR_PTR(-ENOMEM); | |
7041 | } | |
7042 | *cc = new_cands; | |
7043 | return new_cands; | |
7044 | } | |
7045 | ||
29f2e5bd | 7046 | #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
1e89106d AS |
7047 | static void __purge_cand_cache(struct btf *btf, struct bpf_cand_cache **cache, |
7048 | int cache_size) | |
7049 | { | |
7050 | struct bpf_cand_cache *cc; | |
7051 | int i, j; | |
7052 | ||
7053 | for (i = 0; i < cache_size; i++) { | |
7054 | cc = cache[i]; | |
7055 | if (!cc) | |
7056 | continue; | |
7057 | if (!btf) { | |
7058 | /* when new module is loaded purge all of module_cand_cache, | |
7059 | * since new module might have candidates with the name | |
7060 | * that matches cached cands. | |
7061 | */ | |
7062 | bpf_free_cands_from_cache(cc); | |
7063 | cache[i] = NULL; | |
7064 | continue; | |
7065 | } | |
7066 | /* when module is unloaded purge cache entries | |
7067 | * that match module's btf | |
7068 | */ | |
7069 | for (j = 0; j < cc->cnt; j++) | |
7070 | if (cc->cands[j].btf == btf) { | |
7071 | bpf_free_cands_from_cache(cc); | |
7072 | cache[i] = NULL; | |
7073 | break; | |
7074 | } | |
7075 | } | |
7076 | ||
7077 | } | |
7078 | ||
7079 | static void purge_cand_cache(struct btf *btf) | |
7080 | { | |
7081 | mutex_lock(&cand_cache_mutex); | |
7082 | __purge_cand_cache(btf, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
7083 | mutex_unlock(&cand_cache_mutex); | |
7084 | } | |
29f2e5bd | 7085 | #endif |
1e89106d AS |
7086 | |
7087 | static struct bpf_cand_cache * | |
7088 | bpf_core_add_cands(struct bpf_cand_cache *cands, const struct btf *targ_btf, | |
7089 | int targ_start_id) | |
7090 | { | |
7091 | struct bpf_cand_cache *new_cands; | |
7092 | const struct btf_type *t; | |
7093 | const char *targ_name; | |
7094 | size_t targ_essent_len; | |
7095 | int n, i; | |
7096 | ||
7097 | n = btf_nr_types(targ_btf); | |
7098 | for (i = targ_start_id; i < n; i++) { | |
7099 | t = btf_type_by_id(targ_btf, i); | |
7100 | if (btf_kind(t) != cands->kind) | |
7101 | continue; | |
7102 | ||
7103 | targ_name = btf_name_by_offset(targ_btf, t->name_off); | |
7104 | if (!targ_name) | |
7105 | continue; | |
7106 | ||
7107 | /* the resched point is before strncmp to make sure that search | |
7108 | * for non-existing name will have a chance to schedule(). | |
7109 | */ | |
7110 | cond_resched(); | |
7111 | ||
7112 | if (strncmp(cands->name, targ_name, cands->name_len) != 0) | |
7113 | continue; | |
7114 | ||
7115 | targ_essent_len = bpf_core_essential_name_len(targ_name); | |
7116 | if (targ_essent_len != cands->name_len) | |
7117 | continue; | |
7118 | ||
7119 | /* most of the time there is only one candidate for a given kind+name pair */ | |
7120 | new_cands = kmalloc(sizeof_cands(cands->cnt + 1), GFP_KERNEL); | |
7121 | if (!new_cands) { | |
7122 | bpf_free_cands(cands); | |
7123 | return ERR_PTR(-ENOMEM); | |
7124 | } | |
7125 | ||
7126 | memcpy(new_cands, cands, sizeof_cands(cands->cnt)); | |
7127 | bpf_free_cands(cands); | |
7128 | cands = new_cands; | |
7129 | cands->cands[cands->cnt].btf = targ_btf; | |
7130 | cands->cands[cands->cnt].id = i; | |
7131 | cands->cnt++; | |
7132 | } | |
7133 | return cands; | |
7134 | } | |
7135 | ||
7136 | static struct bpf_cand_cache * | |
7137 | bpf_core_find_cands(struct bpf_core_ctx *ctx, u32 local_type_id) | |
7138 | { | |
7139 | struct bpf_cand_cache *cands, *cc, local_cand = {}; | |
7140 | const struct btf *local_btf = ctx->btf; | |
7141 | const struct btf_type *local_type; | |
7142 | const struct btf *main_btf; | |
7143 | size_t local_essent_len; | |
7144 | struct btf *mod_btf; | |
7145 | const char *name; | |
7146 | int id; | |
7147 | ||
7148 | main_btf = bpf_get_btf_vmlinux(); | |
7149 | if (IS_ERR(main_btf)) | |
f18a4997 | 7150 | return ERR_CAST(main_btf); |
1e89106d AS |
7151 | |
7152 | local_type = btf_type_by_id(local_btf, local_type_id); | |
7153 | if (!local_type) | |
7154 | return ERR_PTR(-EINVAL); | |
7155 | ||
7156 | name = btf_name_by_offset(local_btf, local_type->name_off); | |
7157 | if (str_is_empty(name)) | |
7158 | return ERR_PTR(-EINVAL); | |
7159 | local_essent_len = bpf_core_essential_name_len(name); | |
7160 | ||
7161 | cands = &local_cand; | |
7162 | cands->name = name; | |
7163 | cands->kind = btf_kind(local_type); | |
7164 | cands->name_len = local_essent_len; | |
7165 | ||
7166 | cc = check_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); | |
7167 | /* cands is a pointer to stack here */ | |
7168 | if (cc) { | |
7169 | if (cc->cnt) | |
7170 | return cc; | |
7171 | goto check_modules; | |
7172 | } | |
7173 | ||
7174 | /* Attempt to find target candidates in vmlinux BTF first */ | |
7175 | cands = bpf_core_add_cands(cands, main_btf, 1); | |
7176 | if (IS_ERR(cands)) | |
f18a4997 | 7177 | return ERR_CAST(cands); |
1e89106d AS |
7178 | |
7179 | /* cands is a pointer to kmalloced memory here if cands->cnt > 0 */ | |
7180 | ||
7181 | /* populate cache even when cands->cnt == 0 */ | |
7182 | cc = populate_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); | |
7183 | if (IS_ERR(cc)) | |
f18a4997 | 7184 | return ERR_CAST(cc); |
1e89106d AS |
7185 | |
7186 | /* if vmlinux BTF has any candidate, don't go for module BTFs */ | |
7187 | if (cc->cnt) | |
7188 | return cc; | |
7189 | ||
7190 | check_modules: | |
7191 | /* cands is a pointer to stack here and cands->cnt == 0 */ | |
7192 | cc = check_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
7193 | if (cc) | |
7194 | /* if cache has it return it even if cc->cnt == 0 */ | |
7195 | return cc; | |
7196 | ||
7197 | /* If candidate is not found in vmlinux's BTF then search in module's BTFs */ | |
7198 | spin_lock_bh(&btf_idr_lock); | |
7199 | idr_for_each_entry(&btf_idr, mod_btf, id) { | |
7200 | if (!btf_is_module(mod_btf)) | |
7201 | continue; | |
7202 | /* linear search could be slow hence unlock/lock | |
7203 | * the IDR to avoiding holding it for too long | |
7204 | */ | |
7205 | btf_get(mod_btf); | |
7206 | spin_unlock_bh(&btf_idr_lock); | |
7207 | cands = bpf_core_add_cands(cands, mod_btf, btf_nr_types(main_btf)); | |
7208 | if (IS_ERR(cands)) { | |
7209 | btf_put(mod_btf); | |
f18a4997 | 7210 | return ERR_CAST(cands); |
1e89106d AS |
7211 | } |
7212 | spin_lock_bh(&btf_idr_lock); | |
7213 | btf_put(mod_btf); | |
7214 | } | |
7215 | spin_unlock_bh(&btf_idr_lock); | |
7216 | /* cands is a pointer to kmalloced memory here if cands->cnt > 0 | |
7217 | * or pointer to stack if cands->cnd == 0. | |
7218 | * Copy it into the cache even when cands->cnt == 0 and | |
7219 | * return the result. | |
7220 | */ | |
7221 | return populate_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE); | |
7222 | } | |
7223 | ||
fbd94c7a AS |
7224 | int bpf_core_apply(struct bpf_core_ctx *ctx, const struct bpf_core_relo *relo, |
7225 | int relo_idx, void *insn) | |
7226 | { | |
1e89106d AS |
7227 | bool need_cands = relo->kind != BPF_CORE_TYPE_ID_LOCAL; |
7228 | struct bpf_core_cand_list cands = {}; | |
adb8fa19 | 7229 | struct bpf_core_relo_res targ_res; |
78c1f8d0 | 7230 | struct bpf_core_spec *specs; |
1e89106d AS |
7231 | int err; |
7232 | ||
78c1f8d0 AS |
7233 | /* ~4k of temp memory necessary to convert LLVM spec like "0:1:0:5" |
7234 | * into arrays of btf_ids of struct fields and array indices. | |
7235 | */ | |
7236 | specs = kcalloc(3, sizeof(*specs), GFP_KERNEL); | |
7237 | if (!specs) | |
7238 | return -ENOMEM; | |
7239 | ||
1e89106d AS |
7240 | if (need_cands) { |
7241 | struct bpf_cand_cache *cc; | |
7242 | int i; | |
7243 | ||
7244 | mutex_lock(&cand_cache_mutex); | |
7245 | cc = bpf_core_find_cands(ctx, relo->type_id); | |
7246 | if (IS_ERR(cc)) { | |
7247 | bpf_log(ctx->log, "target candidate search failed for %d\n", | |
7248 | relo->type_id); | |
7249 | err = PTR_ERR(cc); | |
7250 | goto out; | |
7251 | } | |
7252 | if (cc->cnt) { | |
7253 | cands.cands = kcalloc(cc->cnt, sizeof(*cands.cands), GFP_KERNEL); | |
7254 | if (!cands.cands) { | |
7255 | err = -ENOMEM; | |
7256 | goto out; | |
7257 | } | |
7258 | } | |
7259 | for (i = 0; i < cc->cnt; i++) { | |
7260 | bpf_log(ctx->log, | |
7261 | "CO-RE relocating %s %s: found target candidate [%d]\n", | |
7262 | btf_kind_str[cc->kind], cc->name, cc->cands[i].id); | |
7263 | cands.cands[i].btf = cc->cands[i].btf; | |
7264 | cands.cands[i].id = cc->cands[i].id; | |
7265 | } | |
7266 | cands.len = cc->cnt; | |
7267 | /* cand_cache_mutex needs to span the cache lookup and | |
7268 | * copy of btf pointer into bpf_core_cand_list, | |
adb8fa19 | 7269 | * since module can be unloaded while bpf_core_calc_relo_insn |
1e89106d AS |
7270 | * is working with module's btf. |
7271 | */ | |
7272 | } | |
7273 | ||
adb8fa19 MV |
7274 | err = bpf_core_calc_relo_insn((void *)ctx->log, relo, relo_idx, ctx->btf, &cands, specs, |
7275 | &targ_res); | |
7276 | if (err) | |
7277 | goto out; | |
7278 | ||
7279 | err = bpf_core_patch_insn((void *)ctx->log, insn, relo->insn_off / 8, relo, relo_idx, | |
7280 | &targ_res); | |
7281 | ||
1e89106d | 7282 | out: |
78c1f8d0 | 7283 | kfree(specs); |
1e89106d AS |
7284 | if (need_cands) { |
7285 | kfree(cands.cands); | |
7286 | mutex_unlock(&cand_cache_mutex); | |
7287 | if (ctx->log->level & BPF_LOG_LEVEL2) | |
7288 | print_cand_cache(ctx->log); | |
7289 | } | |
7290 | return err; | |
fbd94c7a | 7291 | } |