1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* Copyright (c) 2018 Facebook */
4 #include <uapi/linux/btf.h>
5 #include <uapi/linux/bpf.h>
6 #include <uapi/linux/bpf_perf_event.h>
7 #include <uapi/linux/types.h>
8 #include <linux/seq_file.h>
9 #include <linux/compiler.h>
10 #include <linux/ctype.h>
11 #include <linux/errno.h>
12 #include <linux/slab.h>
13 #include <linux/anon_inodes.h>
14 #include <linux/file.h>
15 #include <linux/uaccess.h>
16 #include <linux/kernel.h>
17 #include <linux/idr.h>
18 #include <linux/sort.h>
19 #include <linux/bpf_verifier.h>
20 #include <linux/btf.h>
21 #include <linux/skmsg.h>
22 #include <linux/perf_event.h>
25 /* BTF (BPF Type Format) is the meta data format which describes
26 * the data types of BPF program/map. Hence, it basically focus
27 * on the C programming language which the modern BPF is primary
32 * The BTF data is stored under the ".BTF" ELF section
36 * Each 'struct btf_type' object describes a C data type.
37 * Depending on the type it is describing, a 'struct btf_type'
38 * object may be followed by more data. F.e.
39 * To describe an array, 'struct btf_type' is followed by
42 * 'struct btf_type' and any extra data following it are
47 * The BTF type section contains a list of 'struct btf_type' objects.
48 * Each one describes a C type. Recall from the above section
49 * that a 'struct btf_type' object could be immediately followed by extra
50 * data in order to desribe some particular C types.
54 * Each btf_type object is identified by a type_id. The type_id
55 * is implicitly implied by the location of the btf_type object in
56 * the BTF type section. The first one has type_id 1. The second
57 * one has type_id 2...etc. Hence, an earlier btf_type has
60 * A btf_type object may refer to another btf_type object by using
61 * type_id (i.e. the "type" in the "struct btf_type").
63 * NOTE that we cannot assume any reference-order.
64 * A btf_type object can refer to an earlier btf_type object
65 * but it can also refer to a later btf_type object.
67 * For example, to describe "const void *". A btf_type
68 * object describing "const" may refer to another btf_type
69 * object describing "void *". This type-reference is done
70 * by specifying type_id:
72 * [1] CONST (anon) type_id=2
73 * [2] PTR (anon) type_id=0
75 * The above is the btf_verifier debug log:
76 * - Each line started with "[?]" is a btf_type object
77 * - [?] is the type_id of the btf_type object.
78 * - CONST/PTR is the BTF_KIND_XXX
79 * - "(anon)" is the name of the type. It just
80 * happens that CONST and PTR has no name.
81 * - type_id=XXX is the 'u32 type' in btf_type
83 * NOTE: "void" has type_id 0
87 * The BTF string section contains the names used by the type section.
88 * Each string is referred by an "offset" from the beginning of the
91 * Each string is '\0' terminated.
93 * The first character in the string section must be '\0'
94 * which is used to mean 'anonymous'. Some btf_type may not
100 * To verify BTF data, two passes are needed.
104 * The first pass is to collect all btf_type objects to
105 * an array: "btf->types".
107 * Depending on the C type that a btf_type is describing,
108 * a btf_type may be followed by extra data. We don't know
109 * how many btf_type is there, and more importantly we don't
110 * know where each btf_type is located in the type section.
112 * Without knowing the location of each type_id, most verifications
113 * cannot be done. e.g. an earlier btf_type may refer to a later
114 * btf_type (recall the "const void *" above), so we cannot
115 * check this type-reference in the first pass.
117 * In the first pass, it still does some verifications (e.g.
118 * checking the name is a valid offset to the string section).
122 * The main focus is to resolve a btf_type that is referring
125 * We have to ensure the referring type:
126 * 1) does exist in the BTF (i.e. in btf->types[])
127 * 2) does not cause a loop:
136 * btf_type_needs_resolve() decides if a btf_type needs
139 * The needs_resolve type implements the "resolve()" ops which
140 * essentially does a DFS and detects backedge.
142 * During resolve (or DFS), different C types have different
143 * "RESOLVED" conditions.
145 * When resolving a BTF_KIND_STRUCT, we need to resolve all its
146 * members because a member is always referring to another
147 * type. A struct's member can be treated as "RESOLVED" if
148 * it is referring to a BTF_KIND_PTR. Otherwise, the
149 * following valid C struct would be rejected:
156 * When resolving a BTF_KIND_PTR, it needs to keep resolving if
157 * it is referring to another BTF_KIND_PTR. Otherwise, we cannot
158 * detect a pointer loop, e.g.:
159 * BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR +
161 * +-----------------------------------------+
165 #define BITS_PER_U128 (sizeof(u64) * BITS_PER_BYTE * 2)
166 #define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1)
167 #define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK)
168 #define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3)
169 #define BITS_ROUNDUP_BYTES(bits) \
170 (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits))
172 #define BTF_INFO_MASK 0x8f00ffff
173 #define BTF_INT_MASK 0x0fffffff
174 #define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE)
175 #define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET)
177 /* 16MB for 64k structs and each has 16 members and
178 * a few MB spaces for the string section.
179 * The hard limit is S32_MAX.
181 #define BTF_MAX_SIZE (16 * 1024 * 1024)
183 #define for_each_member_from(i, from, struct_type, member) \
184 for (i = from, member = btf_type_member(struct_type) + from; \
185 i < btf_type_vlen(struct_type); \
188 #define for_each_vsi(i, struct_type, member) \
189 for (i = 0, member = btf_type_var_secinfo(struct_type); \
190 i < btf_type_vlen(struct_type); \
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); \
199 DEFINE_SPINLOCK(btf_idr_lock);
203 struct btf_type **types;
208 struct btf_header hdr;
217 enum verifier_phase {
222 struct resolve_vertex {
223 const struct btf_type *t;
235 RESOLVE_TBD, /* To Be Determined */
236 RESOLVE_PTR, /* Resolving for Pointer */
237 RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union
242 #define MAX_RESOLVE_DEPTH 32
244 struct btf_sec_info {
249 struct btf_verifier_env {
252 struct resolve_vertex stack[MAX_RESOLVE_DEPTH];
253 struct bpf_verifier_log log;
256 enum verifier_phase phase;
257 enum resolve_mode resolve_mode;
260 static const char * const btf_kind_str[NR_BTF_KINDS] = {
261 [BTF_KIND_UNKN] = "UNKNOWN",
262 [BTF_KIND_INT] = "INT",
263 [BTF_KIND_PTR] = "PTR",
264 [BTF_KIND_ARRAY] = "ARRAY",
265 [BTF_KIND_STRUCT] = "STRUCT",
266 [BTF_KIND_UNION] = "UNION",
267 [BTF_KIND_ENUM] = "ENUM",
268 [BTF_KIND_FWD] = "FWD",
269 [BTF_KIND_TYPEDEF] = "TYPEDEF",
270 [BTF_KIND_VOLATILE] = "VOLATILE",
271 [BTF_KIND_CONST] = "CONST",
272 [BTF_KIND_RESTRICT] = "RESTRICT",
273 [BTF_KIND_FUNC] = "FUNC",
274 [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO",
275 [BTF_KIND_VAR] = "VAR",
276 [BTF_KIND_DATASEC] = "DATASEC",
279 static const char *btf_type_str(const struct btf_type *t)
281 return btf_kind_str[BTF_INFO_KIND(t->info)];
284 struct btf_kind_operations {
285 s32 (*check_meta)(struct btf_verifier_env *env,
286 const struct btf_type *t,
288 int (*resolve)(struct btf_verifier_env *env,
289 const struct resolve_vertex *v);
290 int (*check_member)(struct btf_verifier_env *env,
291 const struct btf_type *struct_type,
292 const struct btf_member *member,
293 const struct btf_type *member_type);
294 int (*check_kflag_member)(struct btf_verifier_env *env,
295 const struct btf_type *struct_type,
296 const struct btf_member *member,
297 const struct btf_type *member_type);
298 void (*log_details)(struct btf_verifier_env *env,
299 const struct btf_type *t);
300 void (*seq_show)(const struct btf *btf, const struct btf_type *t,
301 u32 type_id, void *data, u8 bits_offsets,
305 static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS];
306 static struct btf_type btf_void;
308 static int btf_resolve(struct btf_verifier_env *env,
309 const struct btf_type *t, u32 type_id);
311 static bool btf_type_is_modifier(const struct btf_type *t)
313 /* Some of them is not strictly a C modifier
314 * but they are grouped into the same bucket
316 * A type (t) that refers to another
317 * type through t->type AND its size cannot
318 * be determined without following the t->type.
320 * ptr does not fall into this bucket
321 * because its size is always sizeof(void *).
323 switch (BTF_INFO_KIND(t->info)) {
324 case BTF_KIND_TYPEDEF:
325 case BTF_KIND_VOLATILE:
327 case BTF_KIND_RESTRICT:
334 bool btf_type_is_void(const struct btf_type *t)
336 return t == &btf_void;
339 static bool btf_type_is_fwd(const struct btf_type *t)
341 return BTF_INFO_KIND(t->info) == BTF_KIND_FWD;
344 static bool btf_type_nosize(const struct btf_type *t)
346 return btf_type_is_void(t) || btf_type_is_fwd(t) ||
347 btf_type_is_func(t) || btf_type_is_func_proto(t);
350 static bool btf_type_nosize_or_null(const struct btf_type *t)
352 return !t || btf_type_nosize(t);
355 /* union is only a special case of struct:
356 * all its offsetof(member) == 0
358 static bool btf_type_is_struct(const struct btf_type *t)
360 u8 kind = BTF_INFO_KIND(t->info);
362 return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
365 static bool __btf_type_is_struct(const struct btf_type *t)
367 return BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT;
370 static bool btf_type_is_array(const struct btf_type *t)
372 return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY;
375 static bool btf_type_is_var(const struct btf_type *t)
377 return BTF_INFO_KIND(t->info) == BTF_KIND_VAR;
380 static bool btf_type_is_datasec(const struct btf_type *t)
382 return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC;
385 s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind)
387 const struct btf_type *t;
391 for (i = 1; i <= btf->nr_types; i++) {
393 if (BTF_INFO_KIND(t->info) != kind)
396 tname = btf_name_by_offset(btf, t->name_off);
397 if (!strcmp(tname, name))
404 const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
407 const struct btf_type *t = btf_type_by_id(btf, id);
409 while (btf_type_is_modifier(t)) {
411 t = btf_type_by_id(btf, t->type);
420 const struct btf_type *btf_type_resolve_ptr(const struct btf *btf,
423 const struct btf_type *t;
425 t = btf_type_skip_modifiers(btf, id, NULL);
426 if (!btf_type_is_ptr(t))
429 return btf_type_skip_modifiers(btf, t->type, res_id);
432 const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
435 const struct btf_type *ptype;
437 ptype = btf_type_resolve_ptr(btf, id, res_id);
438 if (ptype && btf_type_is_func_proto(ptype))
444 /* Types that act only as a source, not sink or intermediate
445 * type when resolving.
447 static bool btf_type_is_resolve_source_only(const struct btf_type *t)
449 return btf_type_is_var(t) ||
450 btf_type_is_datasec(t);
453 /* What types need to be resolved?
455 * btf_type_is_modifier() is an obvious one.
457 * btf_type_is_struct() because its member refers to
458 * another type (through member->type).
460 * btf_type_is_var() because the variable refers to
461 * another type. btf_type_is_datasec() holds multiple
462 * btf_type_is_var() types that need resolving.
464 * btf_type_is_array() because its element (array->type)
465 * refers to another type. Array can be thought of a
466 * special case of struct while array just has the same
467 * member-type repeated by array->nelems of times.
469 static bool btf_type_needs_resolve(const struct btf_type *t)
471 return btf_type_is_modifier(t) ||
472 btf_type_is_ptr(t) ||
473 btf_type_is_struct(t) ||
474 btf_type_is_array(t) ||
475 btf_type_is_var(t) ||
476 btf_type_is_datasec(t);
479 /* t->size can be used */
480 static bool btf_type_has_size(const struct btf_type *t)
482 switch (BTF_INFO_KIND(t->info)) {
484 case BTF_KIND_STRUCT:
487 case BTF_KIND_DATASEC:
494 static const char *btf_int_encoding_str(u8 encoding)
498 else if (encoding == BTF_INT_SIGNED)
500 else if (encoding == BTF_INT_CHAR)
502 else if (encoding == BTF_INT_BOOL)
508 static u32 btf_type_int(const struct btf_type *t)
510 return *(u32 *)(t + 1);
513 static const struct btf_array *btf_type_array(const struct btf_type *t)
515 return (const struct btf_array *)(t + 1);
518 static const struct btf_enum *btf_type_enum(const struct btf_type *t)
520 return (const struct btf_enum *)(t + 1);
523 static const struct btf_var *btf_type_var(const struct btf_type *t)
525 return (const struct btf_var *)(t + 1);
528 static const struct btf_var_secinfo *btf_type_var_secinfo(const struct btf_type *t)
530 return (const struct btf_var_secinfo *)(t + 1);
533 static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t)
535 return kind_ops[BTF_INFO_KIND(t->info)];
538 static bool btf_name_offset_valid(const struct btf *btf, u32 offset)
540 return BTF_STR_OFFSET_VALID(offset) &&
541 offset < btf->hdr.str_len;
544 static bool __btf_name_char_ok(char c, bool first, bool dot_ok)
546 if ((first ? !isalpha(c) :
549 ((c == '.' && !dot_ok) ||
555 static bool __btf_name_valid(const struct btf *btf, u32 offset, bool dot_ok)
557 /* offset must be valid */
558 const char *src = &btf->strings[offset];
559 const char *src_limit;
561 if (!__btf_name_char_ok(*src, true, dot_ok))
564 /* set a limit on identifier length */
565 src_limit = src + KSYM_NAME_LEN;
567 while (*src && src < src_limit) {
568 if (!__btf_name_char_ok(*src, false, dot_ok))
576 /* Only C-style identifier is permitted. This can be relaxed if
579 static bool btf_name_valid_identifier(const struct btf *btf, u32 offset)
581 return __btf_name_valid(btf, offset, false);
584 static bool btf_name_valid_section(const struct btf *btf, u32 offset)
586 return __btf_name_valid(btf, offset, true);
589 static const char *__btf_name_by_offset(const struct btf *btf, u32 offset)
593 else if (offset < btf->hdr.str_len)
594 return &btf->strings[offset];
596 return "(invalid-name-offset)";
599 const char *btf_name_by_offset(const struct btf *btf, u32 offset)
601 if (offset < btf->hdr.str_len)
602 return &btf->strings[offset];
607 const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id)
609 if (type_id > btf->nr_types)
612 return btf->types[type_id];
616 * Regular int is not a bit field and it must be either
617 * u8/u16/u32/u64 or __int128.
619 static bool btf_type_int_is_regular(const struct btf_type *t)
621 u8 nr_bits, nr_bytes;
624 int_data = btf_type_int(t);
625 nr_bits = BTF_INT_BITS(int_data);
626 nr_bytes = BITS_ROUNDUP_BYTES(nr_bits);
627 if (BITS_PER_BYTE_MASKED(nr_bits) ||
628 BTF_INT_OFFSET(int_data) ||
629 (nr_bytes != sizeof(u8) && nr_bytes != sizeof(u16) &&
630 nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64) &&
631 nr_bytes != (2 * sizeof(u64)))) {
639 * Check that given struct member is a regular int with expected
642 bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
643 const struct btf_member *m,
644 u32 expected_offset, u32 expected_size)
646 const struct btf_type *t;
651 t = btf_type_id_size(btf, &id, NULL);
652 if (!t || !btf_type_is_int(t))
655 int_data = btf_type_int(t);
656 nr_bits = BTF_INT_BITS(int_data);
657 if (btf_type_kflag(s)) {
658 u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset);
659 u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset);
661 /* if kflag set, int should be a regular int and
662 * bit offset should be at byte boundary.
664 return !bitfield_size &&
665 BITS_ROUNDUP_BYTES(bit_offset) == expected_offset &&
666 BITS_ROUNDUP_BYTES(nr_bits) == expected_size;
669 if (BTF_INT_OFFSET(int_data) ||
670 BITS_PER_BYTE_MASKED(m->offset) ||
671 BITS_ROUNDUP_BYTES(m->offset) != expected_offset ||
672 BITS_PER_BYTE_MASKED(nr_bits) ||
673 BITS_ROUNDUP_BYTES(nr_bits) != expected_size)
679 __printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log,
680 const char *fmt, ...)
685 bpf_verifier_vlog(log, fmt, args);
689 __printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env,
690 const char *fmt, ...)
692 struct bpf_verifier_log *log = &env->log;
695 if (!bpf_verifier_log_needed(log))
699 bpf_verifier_vlog(log, fmt, args);
703 __printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env,
704 const struct btf_type *t,
706 const char *fmt, ...)
708 struct bpf_verifier_log *log = &env->log;
709 u8 kind = BTF_INFO_KIND(t->info);
710 struct btf *btf = env->btf;
713 if (!bpf_verifier_log_needed(log))
716 /* btf verifier prints all types it is processing via
717 * btf_verifier_log_type(..., fmt = NULL).
718 * Skip those prints for in-kernel BTF verification.
720 if (log->level == BPF_LOG_KERNEL && !fmt)
723 __btf_verifier_log(log, "[%u] %s %s%s",
726 __btf_name_by_offset(btf, t->name_off),
727 log_details ? " " : "");
730 btf_type_ops(t)->log_details(env, t);
733 __btf_verifier_log(log, " ");
735 bpf_verifier_vlog(log, fmt, args);
739 __btf_verifier_log(log, "\n");
742 #define btf_verifier_log_type(env, t, ...) \
743 __btf_verifier_log_type((env), (t), true, __VA_ARGS__)
744 #define btf_verifier_log_basic(env, t, ...) \
745 __btf_verifier_log_type((env), (t), false, __VA_ARGS__)
748 static void btf_verifier_log_member(struct btf_verifier_env *env,
749 const struct btf_type *struct_type,
750 const struct btf_member *member,
751 const char *fmt, ...)
753 struct bpf_verifier_log *log = &env->log;
754 struct btf *btf = env->btf;
757 if (!bpf_verifier_log_needed(log))
760 if (log->level == BPF_LOG_KERNEL && !fmt)
762 /* The CHECK_META phase already did a btf dump.
764 * If member is logged again, it must hit an error in
765 * parsing this member. It is useful to print out which
766 * struct this member belongs to.
768 if (env->phase != CHECK_META)
769 btf_verifier_log_type(env, struct_type, NULL);
771 if (btf_type_kflag(struct_type))
772 __btf_verifier_log(log,
773 "\t%s type_id=%u bitfield_size=%u bits_offset=%u",
774 __btf_name_by_offset(btf, member->name_off),
776 BTF_MEMBER_BITFIELD_SIZE(member->offset),
777 BTF_MEMBER_BIT_OFFSET(member->offset));
779 __btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u",
780 __btf_name_by_offset(btf, member->name_off),
781 member->type, member->offset);
784 __btf_verifier_log(log, " ");
786 bpf_verifier_vlog(log, fmt, args);
790 __btf_verifier_log(log, "\n");
794 static void btf_verifier_log_vsi(struct btf_verifier_env *env,
795 const struct btf_type *datasec_type,
796 const struct btf_var_secinfo *vsi,
797 const char *fmt, ...)
799 struct bpf_verifier_log *log = &env->log;
802 if (!bpf_verifier_log_needed(log))
804 if (log->level == BPF_LOG_KERNEL && !fmt)
806 if (env->phase != CHECK_META)
807 btf_verifier_log_type(env, datasec_type, NULL);
809 __btf_verifier_log(log, "\t type_id=%u offset=%u size=%u",
810 vsi->type, vsi->offset, vsi->size);
812 __btf_verifier_log(log, " ");
814 bpf_verifier_vlog(log, fmt, args);
818 __btf_verifier_log(log, "\n");
821 static void btf_verifier_log_hdr(struct btf_verifier_env *env,
824 struct bpf_verifier_log *log = &env->log;
825 const struct btf *btf = env->btf;
826 const struct btf_header *hdr;
828 if (!bpf_verifier_log_needed(log))
831 if (log->level == BPF_LOG_KERNEL)
834 __btf_verifier_log(log, "magic: 0x%x\n", hdr->magic);
835 __btf_verifier_log(log, "version: %u\n", hdr->version);
836 __btf_verifier_log(log, "flags: 0x%x\n", hdr->flags);
837 __btf_verifier_log(log, "hdr_len: %u\n", hdr->hdr_len);
838 __btf_verifier_log(log, "type_off: %u\n", hdr->type_off);
839 __btf_verifier_log(log, "type_len: %u\n", hdr->type_len);
840 __btf_verifier_log(log, "str_off: %u\n", hdr->str_off);
841 __btf_verifier_log(log, "str_len: %u\n", hdr->str_len);
842 __btf_verifier_log(log, "btf_total_size: %u\n", btf_data_size);
845 static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t)
847 struct btf *btf = env->btf;
849 /* < 2 because +1 for btf_void which is always in btf->types[0].
850 * btf_void is not accounted in btf->nr_types because btf_void
851 * does not come from the BTF file.
853 if (btf->types_size - btf->nr_types < 2) {
854 /* Expand 'types' array */
856 struct btf_type **new_types;
857 u32 expand_by, new_size;
859 if (btf->types_size == BTF_MAX_TYPE) {
860 btf_verifier_log(env, "Exceeded max num of types");
864 expand_by = max_t(u32, btf->types_size >> 2, 16);
865 new_size = min_t(u32, BTF_MAX_TYPE,
866 btf->types_size + expand_by);
868 new_types = kvcalloc(new_size, sizeof(*new_types),
869 GFP_KERNEL | __GFP_NOWARN);
873 if (btf->nr_types == 0)
874 new_types[0] = &btf_void;
876 memcpy(new_types, btf->types,
877 sizeof(*btf->types) * (btf->nr_types + 1));
880 btf->types = new_types;
881 btf->types_size = new_size;
884 btf->types[++(btf->nr_types)] = t;
889 static int btf_alloc_id(struct btf *btf)
893 idr_preload(GFP_KERNEL);
894 spin_lock_bh(&btf_idr_lock);
895 id = idr_alloc_cyclic(&btf_idr, btf, 1, INT_MAX, GFP_ATOMIC);
898 spin_unlock_bh(&btf_idr_lock);
901 if (WARN_ON_ONCE(!id))
904 return id > 0 ? 0 : id;
907 static void btf_free_id(struct btf *btf)
912 * In map-in-map, calling map_delete_elem() on outer
913 * map will call bpf_map_put on the inner map.
914 * It will then eventually call btf_free_id()
915 * on the inner map. Some of the map_delete_elem()
916 * implementation may have irq disabled, so
917 * we need to use the _irqsave() version instead
918 * of the _bh() version.
920 spin_lock_irqsave(&btf_idr_lock, flags);
921 idr_remove(&btf_idr, btf->id);
922 spin_unlock_irqrestore(&btf_idr_lock, flags);
925 static void btf_free(struct btf *btf)
928 kvfree(btf->resolved_sizes);
929 kvfree(btf->resolved_ids);
934 static void btf_free_rcu(struct rcu_head *rcu)
936 struct btf *btf = container_of(rcu, struct btf, rcu);
941 void btf_put(struct btf *btf)
943 if (btf && refcount_dec_and_test(&btf->refcnt)) {
945 call_rcu(&btf->rcu, btf_free_rcu);
949 static int env_resolve_init(struct btf_verifier_env *env)
951 struct btf *btf = env->btf;
952 u32 nr_types = btf->nr_types;
953 u32 *resolved_sizes = NULL;
954 u32 *resolved_ids = NULL;
955 u8 *visit_states = NULL;
957 /* +1 for btf_void */
958 resolved_sizes = kvcalloc(nr_types + 1, sizeof(*resolved_sizes),
959 GFP_KERNEL | __GFP_NOWARN);
963 resolved_ids = kvcalloc(nr_types + 1, sizeof(*resolved_ids),
964 GFP_KERNEL | __GFP_NOWARN);
968 visit_states = kvcalloc(nr_types + 1, sizeof(*visit_states),
969 GFP_KERNEL | __GFP_NOWARN);
973 btf->resolved_sizes = resolved_sizes;
974 btf->resolved_ids = resolved_ids;
975 env->visit_states = visit_states;
980 kvfree(resolved_sizes);
981 kvfree(resolved_ids);
982 kvfree(visit_states);
986 static void btf_verifier_env_free(struct btf_verifier_env *env)
988 kvfree(env->visit_states);
992 static bool env_type_is_resolve_sink(const struct btf_verifier_env *env,
993 const struct btf_type *next_type)
995 switch (env->resolve_mode) {
997 /* int, enum or void is a sink */
998 return !btf_type_needs_resolve(next_type);
1000 /* int, enum, void, struct, array, func or func_proto is a sink
1003 return !btf_type_is_modifier(next_type) &&
1004 !btf_type_is_ptr(next_type);
1005 case RESOLVE_STRUCT_OR_ARRAY:
1006 /* int, enum, void, ptr, func or func_proto is a sink
1007 * for struct and array
1009 return !btf_type_is_modifier(next_type) &&
1010 !btf_type_is_array(next_type) &&
1011 !btf_type_is_struct(next_type);
1017 static bool env_type_is_resolved(const struct btf_verifier_env *env,
1020 return env->visit_states[type_id] == RESOLVED;
1023 static int env_stack_push(struct btf_verifier_env *env,
1024 const struct btf_type *t, u32 type_id)
1026 struct resolve_vertex *v;
1028 if (env->top_stack == MAX_RESOLVE_DEPTH)
1031 if (env->visit_states[type_id] != NOT_VISITED)
1034 env->visit_states[type_id] = VISITED;
1036 v = &env->stack[env->top_stack++];
1038 v->type_id = type_id;
1041 if (env->resolve_mode == RESOLVE_TBD) {
1042 if (btf_type_is_ptr(t))
1043 env->resolve_mode = RESOLVE_PTR;
1044 else if (btf_type_is_struct(t) || btf_type_is_array(t))
1045 env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY;
1051 static void env_stack_set_next_member(struct btf_verifier_env *env,
1054 env->stack[env->top_stack - 1].next_member = next_member;
1057 static void env_stack_pop_resolved(struct btf_verifier_env *env,
1058 u32 resolved_type_id,
1061 u32 type_id = env->stack[--(env->top_stack)].type_id;
1062 struct btf *btf = env->btf;
1064 btf->resolved_sizes[type_id] = resolved_size;
1065 btf->resolved_ids[type_id] = resolved_type_id;
1066 env->visit_states[type_id] = RESOLVED;
1069 static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env)
1071 return env->top_stack ? &env->stack[env->top_stack - 1] : NULL;
1074 /* Resolve the size of a passed-in "type"
1076 * type: is an array (e.g. u32 array[x][y])
1077 * return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY,
1078 * *type_size: (x * y * sizeof(u32)). Hence, *type_size always
1079 * corresponds to the return type.
1081 * *total_nelems: (x * y). Hence, individual elem size is
1082 * (*type_size / *total_nelems)
1084 * type: is not an array (e.g. const struct X)
1085 * return type: type "struct X"
1086 * *type_size: sizeof(struct X)
1087 * *elem_type: same as return type ("struct X")
1090 const struct btf_type *
1091 btf_resolve_size(const struct btf *btf, const struct btf_type *type,
1092 u32 *type_size, const struct btf_type **elem_type,
1095 const struct btf_type *array_type = NULL;
1096 const struct btf_array *array;
1097 u32 i, size, nelems = 1;
1099 for (i = 0; i < MAX_RESOLVE_DEPTH; i++) {
1100 switch (BTF_INFO_KIND(type->info)) {
1101 /* type->size can be used */
1103 case BTF_KIND_STRUCT:
1104 case BTF_KIND_UNION:
1110 size = sizeof(void *);
1114 case BTF_KIND_TYPEDEF:
1115 case BTF_KIND_VOLATILE:
1116 case BTF_KIND_CONST:
1117 case BTF_KIND_RESTRICT:
1118 type = btf_type_by_id(btf, type->type);
1121 case BTF_KIND_ARRAY:
1124 array = btf_type_array(type);
1125 if (nelems && array->nelems > U32_MAX / nelems)
1126 return ERR_PTR(-EINVAL);
1127 nelems *= array->nelems;
1128 type = btf_type_by_id(btf, array->type);
1131 /* type without size */
1133 return ERR_PTR(-EINVAL);
1137 return ERR_PTR(-EINVAL);
1140 if (nelems && size > U32_MAX / nelems)
1141 return ERR_PTR(-EINVAL);
1143 *type_size = nelems * size;
1145 *total_nelems = nelems;
1149 return array_type ? : type;
1152 /* The input param "type_id" must point to a needs_resolve type */
1153 static const struct btf_type *btf_type_id_resolve(const struct btf *btf,
1156 *type_id = btf->resolved_ids[*type_id];
1157 return btf_type_by_id(btf, *type_id);
1160 const struct btf_type *btf_type_id_size(const struct btf *btf,
1161 u32 *type_id, u32 *ret_size)
1163 const struct btf_type *size_type;
1164 u32 size_type_id = *type_id;
1167 size_type = btf_type_by_id(btf, size_type_id);
1168 if (btf_type_nosize_or_null(size_type))
1171 if (btf_type_has_size(size_type)) {
1172 size = size_type->size;
1173 } else if (btf_type_is_array(size_type)) {
1174 size = btf->resolved_sizes[size_type_id];
1175 } else if (btf_type_is_ptr(size_type)) {
1176 size = sizeof(void *);
1178 if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) &&
1179 !btf_type_is_var(size_type)))
1182 size_type_id = btf->resolved_ids[size_type_id];
1183 size_type = btf_type_by_id(btf, size_type_id);
1184 if (btf_type_nosize_or_null(size_type))
1186 else if (btf_type_has_size(size_type))
1187 size = size_type->size;
1188 else if (btf_type_is_array(size_type))
1189 size = btf->resolved_sizes[size_type_id];
1190 else if (btf_type_is_ptr(size_type))
1191 size = sizeof(void *);
1196 *type_id = size_type_id;
1203 static int btf_df_check_member(struct btf_verifier_env *env,
1204 const struct btf_type *struct_type,
1205 const struct btf_member *member,
1206 const struct btf_type *member_type)
1208 btf_verifier_log_basic(env, struct_type,
1209 "Unsupported check_member");
1213 static int btf_df_check_kflag_member(struct btf_verifier_env *env,
1214 const struct btf_type *struct_type,
1215 const struct btf_member *member,
1216 const struct btf_type *member_type)
1218 btf_verifier_log_basic(env, struct_type,
1219 "Unsupported check_kflag_member");
1223 /* Used for ptr, array and struct/union type members.
1224 * int, enum and modifier types have their specific callback functions.
1226 static int btf_generic_check_kflag_member(struct btf_verifier_env *env,
1227 const struct btf_type *struct_type,
1228 const struct btf_member *member,
1229 const struct btf_type *member_type)
1231 if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) {
1232 btf_verifier_log_member(env, struct_type, member,
1233 "Invalid member bitfield_size");
1237 /* bitfield size is 0, so member->offset represents bit offset only.
1238 * It is safe to call non kflag check_member variants.
1240 return btf_type_ops(member_type)->check_member(env, struct_type,
1245 static int btf_df_resolve(struct btf_verifier_env *env,
1246 const struct resolve_vertex *v)
1248 btf_verifier_log_basic(env, v->t, "Unsupported resolve");
1252 static void btf_df_seq_show(const struct btf *btf, const struct btf_type *t,
1253 u32 type_id, void *data, u8 bits_offsets,
1256 seq_printf(m, "<unsupported kind:%u>", BTF_INFO_KIND(t->info));
1259 static int btf_int_check_member(struct btf_verifier_env *env,
1260 const struct btf_type *struct_type,
1261 const struct btf_member *member,
1262 const struct btf_type *member_type)
1264 u32 int_data = btf_type_int(member_type);
1265 u32 struct_bits_off = member->offset;
1266 u32 struct_size = struct_type->size;
1270 if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) {
1271 btf_verifier_log_member(env, struct_type, member,
1272 "bits_offset exceeds U32_MAX");
1276 struct_bits_off += BTF_INT_OFFSET(int_data);
1277 bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
1278 nr_copy_bits = BTF_INT_BITS(int_data) +
1279 BITS_PER_BYTE_MASKED(struct_bits_off);
1281 if (nr_copy_bits > BITS_PER_U128) {
1282 btf_verifier_log_member(env, struct_type, member,
1283 "nr_copy_bits exceeds 128");
1287 if (struct_size < bytes_offset ||
1288 struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) {
1289 btf_verifier_log_member(env, struct_type, member,
1290 "Member exceeds struct_size");
1297 static int btf_int_check_kflag_member(struct btf_verifier_env *env,
1298 const struct btf_type *struct_type,
1299 const struct btf_member *member,
1300 const struct btf_type *member_type)
1302 u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset;
1303 u32 int_data = btf_type_int(member_type);
1304 u32 struct_size = struct_type->size;
1307 /* a regular int type is required for the kflag int member */
1308 if (!btf_type_int_is_regular(member_type)) {
1309 btf_verifier_log_member(env, struct_type, member,
1310 "Invalid member base type");
1314 /* check sanity of bitfield size */
1315 nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset);
1316 struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset);
1317 nr_int_data_bits = BTF_INT_BITS(int_data);
1319 /* Not a bitfield member, member offset must be at byte
1322 if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
1323 btf_verifier_log_member(env, struct_type, member,
1324 "Invalid member offset");
1328 nr_bits = nr_int_data_bits;
1329 } else if (nr_bits > nr_int_data_bits) {
1330 btf_verifier_log_member(env, struct_type, member,
1331 "Invalid member bitfield_size");
1335 bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
1336 nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off);
1337 if (nr_copy_bits > BITS_PER_U128) {
1338 btf_verifier_log_member(env, struct_type, member,
1339 "nr_copy_bits exceeds 128");
1343 if (struct_size < bytes_offset ||
1344 struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) {
1345 btf_verifier_log_member(env, struct_type, member,
1346 "Member exceeds struct_size");
1353 static s32 btf_int_check_meta(struct btf_verifier_env *env,
1354 const struct btf_type *t,
1357 u32 int_data, nr_bits, meta_needed = sizeof(int_data);
1360 if (meta_left < meta_needed) {
1361 btf_verifier_log_basic(env, t,
1362 "meta_left:%u meta_needed:%u",
1363 meta_left, meta_needed);
1367 if (btf_type_vlen(t)) {
1368 btf_verifier_log_type(env, t, "vlen != 0");
1372 if (btf_type_kflag(t)) {
1373 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
1377 int_data = btf_type_int(t);
1378 if (int_data & ~BTF_INT_MASK) {
1379 btf_verifier_log_basic(env, t, "Invalid int_data:%x",
1384 nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data);
1386 if (nr_bits > BITS_PER_U128) {
1387 btf_verifier_log_type(env, t, "nr_bits exceeds %zu",
1392 if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) {
1393 btf_verifier_log_type(env, t, "nr_bits exceeds type_size");
1398 * Only one of the encoding bits is allowed and it
1399 * should be sufficient for the pretty print purpose (i.e. decoding).
1400 * Multiple bits can be allowed later if it is found
1401 * to be insufficient.
1403 encoding = BTF_INT_ENCODING(int_data);
1405 encoding != BTF_INT_SIGNED &&
1406 encoding != BTF_INT_CHAR &&
1407 encoding != BTF_INT_BOOL) {
1408 btf_verifier_log_type(env, t, "Unsupported encoding");
1412 btf_verifier_log_type(env, t, NULL);
1417 static void btf_int_log(struct btf_verifier_env *env,
1418 const struct btf_type *t)
1420 int int_data = btf_type_int(t);
1422 btf_verifier_log(env,
1423 "size=%u bits_offset=%u nr_bits=%u encoding=%s",
1424 t->size, BTF_INT_OFFSET(int_data),
1425 BTF_INT_BITS(int_data),
1426 btf_int_encoding_str(BTF_INT_ENCODING(int_data)));
1429 static void btf_int128_print(struct seq_file *m, void *data)
1431 /* data points to a __int128 number.
1433 * int128_num = *(__int128 *)data;
1434 * The below formulas shows what upper_num and lower_num represents:
1435 * upper_num = int128_num >> 64;
1436 * lower_num = int128_num & 0xffffffffFFFFFFFFULL;
1438 u64 upper_num, lower_num;
1440 #ifdef __BIG_ENDIAN_BITFIELD
1441 upper_num = *(u64 *)data;
1442 lower_num = *(u64 *)(data + 8);
1444 upper_num = *(u64 *)(data + 8);
1445 lower_num = *(u64 *)data;
1448 seq_printf(m, "0x%llx", lower_num);
1450 seq_printf(m, "0x%llx%016llx", upper_num, lower_num);
1453 static void btf_int128_shift(u64 *print_num, u16 left_shift_bits,
1454 u16 right_shift_bits)
1456 u64 upper_num, lower_num;
1458 #ifdef __BIG_ENDIAN_BITFIELD
1459 upper_num = print_num[0];
1460 lower_num = print_num[1];
1462 upper_num = print_num[1];
1463 lower_num = print_num[0];
1466 /* shake out un-needed bits by shift/or operations */
1467 if (left_shift_bits >= 64) {
1468 upper_num = lower_num << (left_shift_bits - 64);
1471 upper_num = (upper_num << left_shift_bits) |
1472 (lower_num >> (64 - left_shift_bits));
1473 lower_num = lower_num << left_shift_bits;
1476 if (right_shift_bits >= 64) {
1477 lower_num = upper_num >> (right_shift_bits - 64);
1480 lower_num = (lower_num >> right_shift_bits) |
1481 (upper_num << (64 - right_shift_bits));
1482 upper_num = upper_num >> right_shift_bits;
1485 #ifdef __BIG_ENDIAN_BITFIELD
1486 print_num[0] = upper_num;
1487 print_num[1] = lower_num;
1489 print_num[0] = lower_num;
1490 print_num[1] = upper_num;
1494 static void btf_bitfield_seq_show(void *data, u8 bits_offset,
1495 u8 nr_bits, struct seq_file *m)
1497 u16 left_shift_bits, right_shift_bits;
1500 u64 print_num[2] = {};
1502 nr_copy_bits = nr_bits + bits_offset;
1503 nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits);
1505 memcpy(print_num, data, nr_copy_bytes);
1507 #ifdef __BIG_ENDIAN_BITFIELD
1508 left_shift_bits = bits_offset;
1510 left_shift_bits = BITS_PER_U128 - nr_copy_bits;
1512 right_shift_bits = BITS_PER_U128 - nr_bits;
1514 btf_int128_shift(print_num, left_shift_bits, right_shift_bits);
1515 btf_int128_print(m, print_num);
1519 static void btf_int_bits_seq_show(const struct btf *btf,
1520 const struct btf_type *t,
1521 void *data, u8 bits_offset,
1524 u32 int_data = btf_type_int(t);
1525 u8 nr_bits = BTF_INT_BITS(int_data);
1526 u8 total_bits_offset;
1529 * bits_offset is at most 7.
1530 * BTF_INT_OFFSET() cannot exceed 128 bits.
1532 total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data);
1533 data += BITS_ROUNDDOWN_BYTES(total_bits_offset);
1534 bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset);
1535 btf_bitfield_seq_show(data, bits_offset, nr_bits, m);
1538 static void btf_int_seq_show(const struct btf *btf, const struct btf_type *t,
1539 u32 type_id, void *data, u8 bits_offset,
1542 u32 int_data = btf_type_int(t);
1543 u8 encoding = BTF_INT_ENCODING(int_data);
1544 bool sign = encoding & BTF_INT_SIGNED;
1545 u8 nr_bits = BTF_INT_BITS(int_data);
1547 if (bits_offset || BTF_INT_OFFSET(int_data) ||
1548 BITS_PER_BYTE_MASKED(nr_bits)) {
1549 btf_int_bits_seq_show(btf, t, data, bits_offset, m);
1555 btf_int128_print(m, data);
1559 seq_printf(m, "%lld", *(s64 *)data);
1561 seq_printf(m, "%llu", *(u64 *)data);
1565 seq_printf(m, "%d", *(s32 *)data);
1567 seq_printf(m, "%u", *(u32 *)data);
1571 seq_printf(m, "%d", *(s16 *)data);
1573 seq_printf(m, "%u", *(u16 *)data);
1577 seq_printf(m, "%d", *(s8 *)data);
1579 seq_printf(m, "%u", *(u8 *)data);
1582 btf_int_bits_seq_show(btf, t, data, bits_offset, m);
1586 static const struct btf_kind_operations int_ops = {
1587 .check_meta = btf_int_check_meta,
1588 .resolve = btf_df_resolve,
1589 .check_member = btf_int_check_member,
1590 .check_kflag_member = btf_int_check_kflag_member,
1591 .log_details = btf_int_log,
1592 .seq_show = btf_int_seq_show,
1595 static int btf_modifier_check_member(struct btf_verifier_env *env,
1596 const struct btf_type *struct_type,
1597 const struct btf_member *member,
1598 const struct btf_type *member_type)
1600 const struct btf_type *resolved_type;
1601 u32 resolved_type_id = member->type;
1602 struct btf_member resolved_member;
1603 struct btf *btf = env->btf;
1605 resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL);
1606 if (!resolved_type) {
1607 btf_verifier_log_member(env, struct_type, member,
1612 resolved_member = *member;
1613 resolved_member.type = resolved_type_id;
1615 return btf_type_ops(resolved_type)->check_member(env, struct_type,
1620 static int btf_modifier_check_kflag_member(struct btf_verifier_env *env,
1621 const struct btf_type *struct_type,
1622 const struct btf_member *member,
1623 const struct btf_type *member_type)
1625 const struct btf_type *resolved_type;
1626 u32 resolved_type_id = member->type;
1627 struct btf_member resolved_member;
1628 struct btf *btf = env->btf;
1630 resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL);
1631 if (!resolved_type) {
1632 btf_verifier_log_member(env, struct_type, member,
1637 resolved_member = *member;
1638 resolved_member.type = resolved_type_id;
1640 return btf_type_ops(resolved_type)->check_kflag_member(env, struct_type,
1645 static int btf_ptr_check_member(struct btf_verifier_env *env,
1646 const struct btf_type *struct_type,
1647 const struct btf_member *member,
1648 const struct btf_type *member_type)
1650 u32 struct_size, struct_bits_off, bytes_offset;
1652 struct_size = struct_type->size;
1653 struct_bits_off = member->offset;
1654 bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
1656 if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
1657 btf_verifier_log_member(env, struct_type, member,
1658 "Member is not byte aligned");
1662 if (struct_size - bytes_offset < sizeof(void *)) {
1663 btf_verifier_log_member(env, struct_type, member,
1664 "Member exceeds struct_size");
1671 static int btf_ref_type_check_meta(struct btf_verifier_env *env,
1672 const struct btf_type *t,
1675 if (btf_type_vlen(t)) {
1676 btf_verifier_log_type(env, t, "vlen != 0");
1680 if (btf_type_kflag(t)) {
1681 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
1685 if (!BTF_TYPE_ID_VALID(t->type)) {
1686 btf_verifier_log_type(env, t, "Invalid type_id");
1690 /* typedef type must have a valid name, and other ref types,
1691 * volatile, const, restrict, should have a null name.
1693 if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) {
1695 !btf_name_valid_identifier(env->btf, t->name_off)) {
1696 btf_verifier_log_type(env, t, "Invalid name");
1701 btf_verifier_log_type(env, t, "Invalid name");
1706 btf_verifier_log_type(env, t, NULL);
1711 static int btf_modifier_resolve(struct btf_verifier_env *env,
1712 const struct resolve_vertex *v)
1714 const struct btf_type *t = v->t;
1715 const struct btf_type *next_type;
1716 u32 next_type_id = t->type;
1717 struct btf *btf = env->btf;
1719 next_type = btf_type_by_id(btf, next_type_id);
1720 if (!next_type || btf_type_is_resolve_source_only(next_type)) {
1721 btf_verifier_log_type(env, v->t, "Invalid type_id");
1725 if (!env_type_is_resolve_sink(env, next_type) &&
1726 !env_type_is_resolved(env, next_type_id))
1727 return env_stack_push(env, next_type, next_type_id);
1729 /* Figure out the resolved next_type_id with size.
1730 * They will be stored in the current modifier's
1731 * resolved_ids and resolved_sizes such that it can
1732 * save us a few type-following when we use it later (e.g. in
1735 if (!btf_type_id_size(btf, &next_type_id, NULL)) {
1736 if (env_type_is_resolved(env, next_type_id))
1737 next_type = btf_type_id_resolve(btf, &next_type_id);
1739 /* "typedef void new_void", "const void"...etc */
1740 if (!btf_type_is_void(next_type) &&
1741 !btf_type_is_fwd(next_type) &&
1742 !btf_type_is_func_proto(next_type)) {
1743 btf_verifier_log_type(env, v->t, "Invalid type_id");
1748 env_stack_pop_resolved(env, next_type_id, 0);
1753 static int btf_var_resolve(struct btf_verifier_env *env,
1754 const struct resolve_vertex *v)
1756 const struct btf_type *next_type;
1757 const struct btf_type *t = v->t;
1758 u32 next_type_id = t->type;
1759 struct btf *btf = env->btf;
1761 next_type = btf_type_by_id(btf, next_type_id);
1762 if (!next_type || btf_type_is_resolve_source_only(next_type)) {
1763 btf_verifier_log_type(env, v->t, "Invalid type_id");
1767 if (!env_type_is_resolve_sink(env, next_type) &&
1768 !env_type_is_resolved(env, next_type_id))
1769 return env_stack_push(env, next_type, next_type_id);
1771 if (btf_type_is_modifier(next_type)) {
1772 const struct btf_type *resolved_type;
1773 u32 resolved_type_id;
1775 resolved_type_id = next_type_id;
1776 resolved_type = btf_type_id_resolve(btf, &resolved_type_id);
1778 if (btf_type_is_ptr(resolved_type) &&
1779 !env_type_is_resolve_sink(env, resolved_type) &&
1780 !env_type_is_resolved(env, resolved_type_id))
1781 return env_stack_push(env, resolved_type,
1785 /* We must resolve to something concrete at this point, no
1786 * forward types or similar that would resolve to size of
1789 if (!btf_type_id_size(btf, &next_type_id, NULL)) {
1790 btf_verifier_log_type(env, v->t, "Invalid type_id");
1794 env_stack_pop_resolved(env, next_type_id, 0);
1799 static int btf_ptr_resolve(struct btf_verifier_env *env,
1800 const struct resolve_vertex *v)
1802 const struct btf_type *next_type;
1803 const struct btf_type *t = v->t;
1804 u32 next_type_id = t->type;
1805 struct btf *btf = env->btf;
1807 next_type = btf_type_by_id(btf, next_type_id);
1808 if (!next_type || btf_type_is_resolve_source_only(next_type)) {
1809 btf_verifier_log_type(env, v->t, "Invalid type_id");
1813 if (!env_type_is_resolve_sink(env, next_type) &&
1814 !env_type_is_resolved(env, next_type_id))
1815 return env_stack_push(env, next_type, next_type_id);
1817 /* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY,
1818 * the modifier may have stopped resolving when it was resolved
1819 * to a ptr (last-resolved-ptr).
1821 * We now need to continue from the last-resolved-ptr to
1822 * ensure the last-resolved-ptr will not referring back to
1823 * the currenct ptr (t).
1825 if (btf_type_is_modifier(next_type)) {
1826 const struct btf_type *resolved_type;
1827 u32 resolved_type_id;
1829 resolved_type_id = next_type_id;
1830 resolved_type = btf_type_id_resolve(btf, &resolved_type_id);
1832 if (btf_type_is_ptr(resolved_type) &&
1833 !env_type_is_resolve_sink(env, resolved_type) &&
1834 !env_type_is_resolved(env, resolved_type_id))
1835 return env_stack_push(env, resolved_type,
1839 if (!btf_type_id_size(btf, &next_type_id, NULL)) {
1840 if (env_type_is_resolved(env, next_type_id))
1841 next_type = btf_type_id_resolve(btf, &next_type_id);
1843 if (!btf_type_is_void(next_type) &&
1844 !btf_type_is_fwd(next_type) &&
1845 !btf_type_is_func_proto(next_type)) {
1846 btf_verifier_log_type(env, v->t, "Invalid type_id");
1851 env_stack_pop_resolved(env, next_type_id, 0);
1856 static void btf_modifier_seq_show(const struct btf *btf,
1857 const struct btf_type *t,
1858 u32 type_id, void *data,
1859 u8 bits_offset, struct seq_file *m)
1861 if (btf->resolved_ids)
1862 t = btf_type_id_resolve(btf, &type_id);
1864 t = btf_type_skip_modifiers(btf, type_id, NULL);
1866 btf_type_ops(t)->seq_show(btf, t, type_id, data, bits_offset, m);
1869 static void btf_var_seq_show(const struct btf *btf, const struct btf_type *t,
1870 u32 type_id, void *data, u8 bits_offset,
1873 t = btf_type_id_resolve(btf, &type_id);
1875 btf_type_ops(t)->seq_show(btf, t, type_id, data, bits_offset, m);
1878 static void btf_ptr_seq_show(const struct btf *btf, const struct btf_type *t,
1879 u32 type_id, void *data, u8 bits_offset,
1882 /* It is a hashed value */
1883 seq_printf(m, "%p", *(void **)data);
1886 static void btf_ref_type_log(struct btf_verifier_env *env,
1887 const struct btf_type *t)
1889 btf_verifier_log(env, "type_id=%u", t->type);
1892 static struct btf_kind_operations modifier_ops = {
1893 .check_meta = btf_ref_type_check_meta,
1894 .resolve = btf_modifier_resolve,
1895 .check_member = btf_modifier_check_member,
1896 .check_kflag_member = btf_modifier_check_kflag_member,
1897 .log_details = btf_ref_type_log,
1898 .seq_show = btf_modifier_seq_show,
1901 static struct btf_kind_operations ptr_ops = {
1902 .check_meta = btf_ref_type_check_meta,
1903 .resolve = btf_ptr_resolve,
1904 .check_member = btf_ptr_check_member,
1905 .check_kflag_member = btf_generic_check_kflag_member,
1906 .log_details = btf_ref_type_log,
1907 .seq_show = btf_ptr_seq_show,
1910 static s32 btf_fwd_check_meta(struct btf_verifier_env *env,
1911 const struct btf_type *t,
1914 if (btf_type_vlen(t)) {
1915 btf_verifier_log_type(env, t, "vlen != 0");
1920 btf_verifier_log_type(env, t, "type != 0");
1924 /* fwd type must have a valid name */
1926 !btf_name_valid_identifier(env->btf, t->name_off)) {
1927 btf_verifier_log_type(env, t, "Invalid name");
1931 btf_verifier_log_type(env, t, NULL);
1936 static void btf_fwd_type_log(struct btf_verifier_env *env,
1937 const struct btf_type *t)
1939 btf_verifier_log(env, "%s", btf_type_kflag(t) ? "union" : "struct");
1942 static struct btf_kind_operations fwd_ops = {
1943 .check_meta = btf_fwd_check_meta,
1944 .resolve = btf_df_resolve,
1945 .check_member = btf_df_check_member,
1946 .check_kflag_member = btf_df_check_kflag_member,
1947 .log_details = btf_fwd_type_log,
1948 .seq_show = btf_df_seq_show,
1951 static int btf_array_check_member(struct btf_verifier_env *env,
1952 const struct btf_type *struct_type,
1953 const struct btf_member *member,
1954 const struct btf_type *member_type)
1956 u32 struct_bits_off = member->offset;
1957 u32 struct_size, bytes_offset;
1958 u32 array_type_id, array_size;
1959 struct btf *btf = env->btf;
1961 if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
1962 btf_verifier_log_member(env, struct_type, member,
1963 "Member is not byte aligned");
1967 array_type_id = member->type;
1968 btf_type_id_size(btf, &array_type_id, &array_size);
1969 struct_size = struct_type->size;
1970 bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
1971 if (struct_size - bytes_offset < array_size) {
1972 btf_verifier_log_member(env, struct_type, member,
1973 "Member exceeds struct_size");
1980 static s32 btf_array_check_meta(struct btf_verifier_env *env,
1981 const struct btf_type *t,
1984 const struct btf_array *array = btf_type_array(t);
1985 u32 meta_needed = sizeof(*array);
1987 if (meta_left < meta_needed) {
1988 btf_verifier_log_basic(env, t,
1989 "meta_left:%u meta_needed:%u",
1990 meta_left, meta_needed);
1994 /* array type should not have a name */
1996 btf_verifier_log_type(env, t, "Invalid name");
2000 if (btf_type_vlen(t)) {
2001 btf_verifier_log_type(env, t, "vlen != 0");
2005 if (btf_type_kflag(t)) {
2006 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
2011 btf_verifier_log_type(env, t, "size != 0");
2015 /* Array elem type and index type cannot be in type void,
2016 * so !array->type and !array->index_type are not allowed.
2018 if (!array->type || !BTF_TYPE_ID_VALID(array->type)) {
2019 btf_verifier_log_type(env, t, "Invalid elem");
2023 if (!array->index_type || !BTF_TYPE_ID_VALID(array->index_type)) {
2024 btf_verifier_log_type(env, t, "Invalid index");
2028 btf_verifier_log_type(env, t, NULL);
2033 static int btf_array_resolve(struct btf_verifier_env *env,
2034 const struct resolve_vertex *v)
2036 const struct btf_array *array = btf_type_array(v->t);
2037 const struct btf_type *elem_type, *index_type;
2038 u32 elem_type_id, index_type_id;
2039 struct btf *btf = env->btf;
2042 /* Check array->index_type */
2043 index_type_id = array->index_type;
2044 index_type = btf_type_by_id(btf, index_type_id);
2045 if (btf_type_nosize_or_null(index_type) ||
2046 btf_type_is_resolve_source_only(index_type)) {
2047 btf_verifier_log_type(env, v->t, "Invalid index");
2051 if (!env_type_is_resolve_sink(env, index_type) &&
2052 !env_type_is_resolved(env, index_type_id))
2053 return env_stack_push(env, index_type, index_type_id);
2055 index_type = btf_type_id_size(btf, &index_type_id, NULL);
2056 if (!index_type || !btf_type_is_int(index_type) ||
2057 !btf_type_int_is_regular(index_type)) {
2058 btf_verifier_log_type(env, v->t, "Invalid index");
2062 /* Check array->type */
2063 elem_type_id = array->type;
2064 elem_type = btf_type_by_id(btf, elem_type_id);
2065 if (btf_type_nosize_or_null(elem_type) ||
2066 btf_type_is_resolve_source_only(elem_type)) {
2067 btf_verifier_log_type(env, v->t,
2072 if (!env_type_is_resolve_sink(env, elem_type) &&
2073 !env_type_is_resolved(env, elem_type_id))
2074 return env_stack_push(env, elem_type, elem_type_id);
2076 elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size);
2078 btf_verifier_log_type(env, v->t, "Invalid elem");
2082 if (btf_type_is_int(elem_type) && !btf_type_int_is_regular(elem_type)) {
2083 btf_verifier_log_type(env, v->t, "Invalid array of int");
2087 if (array->nelems && elem_size > U32_MAX / array->nelems) {
2088 btf_verifier_log_type(env, v->t,
2089 "Array size overflows U32_MAX");
2093 env_stack_pop_resolved(env, elem_type_id, elem_size * array->nelems);
2098 static void btf_array_log(struct btf_verifier_env *env,
2099 const struct btf_type *t)
2101 const struct btf_array *array = btf_type_array(t);
2103 btf_verifier_log(env, "type_id=%u index_type_id=%u nr_elems=%u",
2104 array->type, array->index_type, array->nelems);
2107 static void btf_array_seq_show(const struct btf *btf, const struct btf_type *t,
2108 u32 type_id, void *data, u8 bits_offset,
2111 const struct btf_array *array = btf_type_array(t);
2112 const struct btf_kind_operations *elem_ops;
2113 const struct btf_type *elem_type;
2114 u32 i, elem_size, elem_type_id;
2116 elem_type_id = array->type;
2117 elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size);
2118 elem_ops = btf_type_ops(elem_type);
2120 for (i = 0; i < array->nelems; i++) {
2124 elem_ops->seq_show(btf, elem_type, elem_type_id, data,
2131 static struct btf_kind_operations array_ops = {
2132 .check_meta = btf_array_check_meta,
2133 .resolve = btf_array_resolve,
2134 .check_member = btf_array_check_member,
2135 .check_kflag_member = btf_generic_check_kflag_member,
2136 .log_details = btf_array_log,
2137 .seq_show = btf_array_seq_show,
2140 static int btf_struct_check_member(struct btf_verifier_env *env,
2141 const struct btf_type *struct_type,
2142 const struct btf_member *member,
2143 const struct btf_type *member_type)
2145 u32 struct_bits_off = member->offset;
2146 u32 struct_size, bytes_offset;
2148 if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
2149 btf_verifier_log_member(env, struct_type, member,
2150 "Member is not byte aligned");
2154 struct_size = struct_type->size;
2155 bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
2156 if (struct_size - bytes_offset < member_type->size) {
2157 btf_verifier_log_member(env, struct_type, member,
2158 "Member exceeds struct_size");
2165 static s32 btf_struct_check_meta(struct btf_verifier_env *env,
2166 const struct btf_type *t,
2169 bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION;
2170 const struct btf_member *member;
2171 u32 meta_needed, last_offset;
2172 struct btf *btf = env->btf;
2173 u32 struct_size = t->size;
2177 meta_needed = btf_type_vlen(t) * sizeof(*member);
2178 if (meta_left < meta_needed) {
2179 btf_verifier_log_basic(env, t,
2180 "meta_left:%u meta_needed:%u",
2181 meta_left, meta_needed);
2185 /* struct type either no name or a valid one */
2187 !btf_name_valid_identifier(env->btf, t->name_off)) {
2188 btf_verifier_log_type(env, t, "Invalid name");
2192 btf_verifier_log_type(env, t, NULL);
2195 for_each_member(i, t, member) {
2196 if (!btf_name_offset_valid(btf, member->name_off)) {
2197 btf_verifier_log_member(env, t, member,
2198 "Invalid member name_offset:%u",
2203 /* struct member either no name or a valid one */
2204 if (member->name_off &&
2205 !btf_name_valid_identifier(btf, member->name_off)) {
2206 btf_verifier_log_member(env, t, member, "Invalid name");
2209 /* A member cannot be in type void */
2210 if (!member->type || !BTF_TYPE_ID_VALID(member->type)) {
2211 btf_verifier_log_member(env, t, member,
2216 offset = btf_member_bit_offset(t, member);
2217 if (is_union && offset) {
2218 btf_verifier_log_member(env, t, member,
2219 "Invalid member bits_offset");
2224 * ">" instead of ">=" because the last member could be
2227 if (last_offset > offset) {
2228 btf_verifier_log_member(env, t, member,
2229 "Invalid member bits_offset");
2233 if (BITS_ROUNDUP_BYTES(offset) > struct_size) {
2234 btf_verifier_log_member(env, t, member,
2235 "Member bits_offset exceeds its struct size");
2239 btf_verifier_log_member(env, t, member, NULL);
2240 last_offset = offset;
2246 static int btf_struct_resolve(struct btf_verifier_env *env,
2247 const struct resolve_vertex *v)
2249 const struct btf_member *member;
2253 /* Before continue resolving the next_member,
2254 * ensure the last member is indeed resolved to a
2255 * type with size info.
2257 if (v->next_member) {
2258 const struct btf_type *last_member_type;
2259 const struct btf_member *last_member;
2260 u16 last_member_type_id;
2262 last_member = btf_type_member(v->t) + v->next_member - 1;
2263 last_member_type_id = last_member->type;
2264 if (WARN_ON_ONCE(!env_type_is_resolved(env,
2265 last_member_type_id)))
2268 last_member_type = btf_type_by_id(env->btf,
2269 last_member_type_id);
2270 if (btf_type_kflag(v->t))
2271 err = btf_type_ops(last_member_type)->check_kflag_member(env, v->t,
2275 err = btf_type_ops(last_member_type)->check_member(env, v->t,
2282 for_each_member_from(i, v->next_member, v->t, member) {
2283 u32 member_type_id = member->type;
2284 const struct btf_type *member_type = btf_type_by_id(env->btf,
2287 if (btf_type_nosize_or_null(member_type) ||
2288 btf_type_is_resolve_source_only(member_type)) {
2289 btf_verifier_log_member(env, v->t, member,
2294 if (!env_type_is_resolve_sink(env, member_type) &&
2295 !env_type_is_resolved(env, member_type_id)) {
2296 env_stack_set_next_member(env, i + 1);
2297 return env_stack_push(env, member_type, member_type_id);
2300 if (btf_type_kflag(v->t))
2301 err = btf_type_ops(member_type)->check_kflag_member(env, v->t,
2305 err = btf_type_ops(member_type)->check_member(env, v->t,
2312 env_stack_pop_resolved(env, 0, 0);
2317 static void btf_struct_log(struct btf_verifier_env *env,
2318 const struct btf_type *t)
2320 btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
2323 /* find 'struct bpf_spin_lock' in map value.
2324 * return >= 0 offset if found
2325 * and < 0 in case of error
2327 int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t)
2329 const struct btf_member *member;
2330 u32 i, off = -ENOENT;
2332 if (!__btf_type_is_struct(t))
2335 for_each_member(i, t, member) {
2336 const struct btf_type *member_type = btf_type_by_id(btf,
2338 if (!__btf_type_is_struct(member_type))
2340 if (member_type->size != sizeof(struct bpf_spin_lock))
2342 if (strcmp(__btf_name_by_offset(btf, member_type->name_off),
2346 /* only one 'struct bpf_spin_lock' is allowed */
2348 off = btf_member_bit_offset(t, member);
2350 /* valid C code cannot generate such BTF */
2353 if (off % __alignof__(struct bpf_spin_lock))
2354 /* valid struct bpf_spin_lock will be 4 byte aligned */
2360 static void btf_struct_seq_show(const struct btf *btf, const struct btf_type *t,
2361 u32 type_id, void *data, u8 bits_offset,
2364 const char *seq = BTF_INFO_KIND(t->info) == BTF_KIND_UNION ? "|" : ",";
2365 const struct btf_member *member;
2369 for_each_member(i, t, member) {
2370 const struct btf_type *member_type = btf_type_by_id(btf,
2372 const struct btf_kind_operations *ops;
2373 u32 member_offset, bitfield_size;
2380 member_offset = btf_member_bit_offset(t, member);
2381 bitfield_size = btf_member_bitfield_size(t, member);
2382 bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset);
2383 bits8_offset = BITS_PER_BYTE_MASKED(member_offset);
2384 if (bitfield_size) {
2385 btf_bitfield_seq_show(data + bytes_offset, bits8_offset,
2388 ops = btf_type_ops(member_type);
2389 ops->seq_show(btf, member_type, member->type,
2390 data + bytes_offset, bits8_offset, m);
2396 static struct btf_kind_operations struct_ops = {
2397 .check_meta = btf_struct_check_meta,
2398 .resolve = btf_struct_resolve,
2399 .check_member = btf_struct_check_member,
2400 .check_kflag_member = btf_generic_check_kflag_member,
2401 .log_details = btf_struct_log,
2402 .seq_show = btf_struct_seq_show,
2405 static int btf_enum_check_member(struct btf_verifier_env *env,
2406 const struct btf_type *struct_type,
2407 const struct btf_member *member,
2408 const struct btf_type *member_type)
2410 u32 struct_bits_off = member->offset;
2411 u32 struct_size, bytes_offset;
2413 if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
2414 btf_verifier_log_member(env, struct_type, member,
2415 "Member is not byte aligned");
2419 struct_size = struct_type->size;
2420 bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
2421 if (struct_size - bytes_offset < member_type->size) {
2422 btf_verifier_log_member(env, struct_type, member,
2423 "Member exceeds struct_size");
2430 static int btf_enum_check_kflag_member(struct btf_verifier_env *env,
2431 const struct btf_type *struct_type,
2432 const struct btf_member *member,
2433 const struct btf_type *member_type)
2435 u32 struct_bits_off, nr_bits, bytes_end, struct_size;
2436 u32 int_bitsize = sizeof(int) * BITS_PER_BYTE;
2438 struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset);
2439 nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset);
2441 if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
2442 btf_verifier_log_member(env, struct_type, member,
2443 "Member is not byte aligned");
2447 nr_bits = int_bitsize;
2448 } else if (nr_bits > int_bitsize) {
2449 btf_verifier_log_member(env, struct_type, member,
2450 "Invalid member bitfield_size");
2454 struct_size = struct_type->size;
2455 bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits);
2456 if (struct_size < bytes_end) {
2457 btf_verifier_log_member(env, struct_type, member,
2458 "Member exceeds struct_size");
2465 static s32 btf_enum_check_meta(struct btf_verifier_env *env,
2466 const struct btf_type *t,
2469 const struct btf_enum *enums = btf_type_enum(t);
2470 struct btf *btf = env->btf;
2474 nr_enums = btf_type_vlen(t);
2475 meta_needed = nr_enums * sizeof(*enums);
2477 if (meta_left < meta_needed) {
2478 btf_verifier_log_basic(env, t,
2479 "meta_left:%u meta_needed:%u",
2480 meta_left, meta_needed);
2484 if (btf_type_kflag(t)) {
2485 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
2489 if (t->size > 8 || !is_power_of_2(t->size)) {
2490 btf_verifier_log_type(env, t, "Unexpected size");
2494 /* enum type either no name or a valid one */
2496 !btf_name_valid_identifier(env->btf, t->name_off)) {
2497 btf_verifier_log_type(env, t, "Invalid name");
2501 btf_verifier_log_type(env, t, NULL);
2503 for (i = 0; i < nr_enums; i++) {
2504 if (!btf_name_offset_valid(btf, enums[i].name_off)) {
2505 btf_verifier_log(env, "\tInvalid name_offset:%u",
2510 /* enum member must have a valid name */
2511 if (!enums[i].name_off ||
2512 !btf_name_valid_identifier(btf, enums[i].name_off)) {
2513 btf_verifier_log_type(env, t, "Invalid name");
2517 if (env->log.level == BPF_LOG_KERNEL)
2519 btf_verifier_log(env, "\t%s val=%d\n",
2520 __btf_name_by_offset(btf, enums[i].name_off),
2527 static void btf_enum_log(struct btf_verifier_env *env,
2528 const struct btf_type *t)
2530 btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
2533 static void btf_enum_seq_show(const struct btf *btf, const struct btf_type *t,
2534 u32 type_id, void *data, u8 bits_offset,
2537 const struct btf_enum *enums = btf_type_enum(t);
2538 u32 i, nr_enums = btf_type_vlen(t);
2539 int v = *(int *)data;
2541 for (i = 0; i < nr_enums; i++) {
2542 if (v == enums[i].val) {
2544 __btf_name_by_offset(btf,
2545 enums[i].name_off));
2550 seq_printf(m, "%d", v);
2553 static struct btf_kind_operations enum_ops = {
2554 .check_meta = btf_enum_check_meta,
2555 .resolve = btf_df_resolve,
2556 .check_member = btf_enum_check_member,
2557 .check_kflag_member = btf_enum_check_kflag_member,
2558 .log_details = btf_enum_log,
2559 .seq_show = btf_enum_seq_show,
2562 static s32 btf_func_proto_check_meta(struct btf_verifier_env *env,
2563 const struct btf_type *t,
2566 u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param);
2568 if (meta_left < meta_needed) {
2569 btf_verifier_log_basic(env, t,
2570 "meta_left:%u meta_needed:%u",
2571 meta_left, meta_needed);
2576 btf_verifier_log_type(env, t, "Invalid name");
2580 if (btf_type_kflag(t)) {
2581 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
2585 btf_verifier_log_type(env, t, NULL);
2590 static void btf_func_proto_log(struct btf_verifier_env *env,
2591 const struct btf_type *t)
2593 const struct btf_param *args = (const struct btf_param *)(t + 1);
2594 u16 nr_args = btf_type_vlen(t), i;
2596 btf_verifier_log(env, "return=%u args=(", t->type);
2598 btf_verifier_log(env, "void");
2602 if (nr_args == 1 && !args[0].type) {
2603 /* Only one vararg */
2604 btf_verifier_log(env, "vararg");
2608 btf_verifier_log(env, "%u %s", args[0].type,
2609 __btf_name_by_offset(env->btf,
2611 for (i = 1; i < nr_args - 1; i++)
2612 btf_verifier_log(env, ", %u %s", args[i].type,
2613 __btf_name_by_offset(env->btf,
2617 const struct btf_param *last_arg = &args[nr_args - 1];
2620 btf_verifier_log(env, ", %u %s", last_arg->type,
2621 __btf_name_by_offset(env->btf,
2622 last_arg->name_off));
2624 btf_verifier_log(env, ", vararg");
2628 btf_verifier_log(env, ")");
2631 static struct btf_kind_operations func_proto_ops = {
2632 .check_meta = btf_func_proto_check_meta,
2633 .resolve = btf_df_resolve,
2635 * BTF_KIND_FUNC_PROTO cannot be directly referred by
2636 * a struct's member.
2638 * It should be a funciton pointer instead.
2639 * (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO)
2641 * Hence, there is no btf_func_check_member().
2643 .check_member = btf_df_check_member,
2644 .check_kflag_member = btf_df_check_kflag_member,
2645 .log_details = btf_func_proto_log,
2646 .seq_show = btf_df_seq_show,
2649 static s32 btf_func_check_meta(struct btf_verifier_env *env,
2650 const struct btf_type *t,
2654 !btf_name_valid_identifier(env->btf, t->name_off)) {
2655 btf_verifier_log_type(env, t, "Invalid name");
2659 if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) {
2660 btf_verifier_log_type(env, t, "Invalid func linkage");
2664 if (btf_type_kflag(t)) {
2665 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
2669 btf_verifier_log_type(env, t, NULL);
2674 static struct btf_kind_operations func_ops = {
2675 .check_meta = btf_func_check_meta,
2676 .resolve = btf_df_resolve,
2677 .check_member = btf_df_check_member,
2678 .check_kflag_member = btf_df_check_kflag_member,
2679 .log_details = btf_ref_type_log,
2680 .seq_show = btf_df_seq_show,
2683 static s32 btf_var_check_meta(struct btf_verifier_env *env,
2684 const struct btf_type *t,
2687 const struct btf_var *var;
2688 u32 meta_needed = sizeof(*var);
2690 if (meta_left < meta_needed) {
2691 btf_verifier_log_basic(env, t,
2692 "meta_left:%u meta_needed:%u",
2693 meta_left, meta_needed);
2697 if (btf_type_vlen(t)) {
2698 btf_verifier_log_type(env, t, "vlen != 0");
2702 if (btf_type_kflag(t)) {
2703 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
2708 !__btf_name_valid(env->btf, t->name_off, true)) {
2709 btf_verifier_log_type(env, t, "Invalid name");
2713 /* A var cannot be in type void */
2714 if (!t->type || !BTF_TYPE_ID_VALID(t->type)) {
2715 btf_verifier_log_type(env, t, "Invalid type_id");
2719 var = btf_type_var(t);
2720 if (var->linkage != BTF_VAR_STATIC &&
2721 var->linkage != BTF_VAR_GLOBAL_ALLOCATED) {
2722 btf_verifier_log_type(env, t, "Linkage not supported");
2726 btf_verifier_log_type(env, t, NULL);
2731 static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t)
2733 const struct btf_var *var = btf_type_var(t);
2735 btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage);
2738 static const struct btf_kind_operations var_ops = {
2739 .check_meta = btf_var_check_meta,
2740 .resolve = btf_var_resolve,
2741 .check_member = btf_df_check_member,
2742 .check_kflag_member = btf_df_check_kflag_member,
2743 .log_details = btf_var_log,
2744 .seq_show = btf_var_seq_show,
2747 static s32 btf_datasec_check_meta(struct btf_verifier_env *env,
2748 const struct btf_type *t,
2751 const struct btf_var_secinfo *vsi;
2752 u64 last_vsi_end_off = 0, sum = 0;
2755 meta_needed = btf_type_vlen(t) * sizeof(*vsi);
2756 if (meta_left < meta_needed) {
2757 btf_verifier_log_basic(env, t,
2758 "meta_left:%u meta_needed:%u",
2759 meta_left, meta_needed);
2763 if (!btf_type_vlen(t)) {
2764 btf_verifier_log_type(env, t, "vlen == 0");
2769 btf_verifier_log_type(env, t, "size == 0");
2773 if (btf_type_kflag(t)) {
2774 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
2779 !btf_name_valid_section(env->btf, t->name_off)) {
2780 btf_verifier_log_type(env, t, "Invalid name");
2784 btf_verifier_log_type(env, t, NULL);
2786 for_each_vsi(i, t, vsi) {
2787 /* A var cannot be in type void */
2788 if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) {
2789 btf_verifier_log_vsi(env, t, vsi,
2794 if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) {
2795 btf_verifier_log_vsi(env, t, vsi,
2800 if (!vsi->size || vsi->size > t->size) {
2801 btf_verifier_log_vsi(env, t, vsi,
2806 last_vsi_end_off = vsi->offset + vsi->size;
2807 if (last_vsi_end_off > t->size) {
2808 btf_verifier_log_vsi(env, t, vsi,
2809 "Invalid offset+size");
2813 btf_verifier_log_vsi(env, t, vsi, NULL);
2817 if (t->size < sum) {
2818 btf_verifier_log_type(env, t, "Invalid btf_info size");
2825 static int btf_datasec_resolve(struct btf_verifier_env *env,
2826 const struct resolve_vertex *v)
2828 const struct btf_var_secinfo *vsi;
2829 struct btf *btf = env->btf;
2832 for_each_vsi_from(i, v->next_member, v->t, vsi) {
2833 u32 var_type_id = vsi->type, type_id, type_size = 0;
2834 const struct btf_type *var_type = btf_type_by_id(env->btf,
2836 if (!var_type || !btf_type_is_var(var_type)) {
2837 btf_verifier_log_vsi(env, v->t, vsi,
2838 "Not a VAR kind member");
2842 if (!env_type_is_resolve_sink(env, var_type) &&
2843 !env_type_is_resolved(env, var_type_id)) {
2844 env_stack_set_next_member(env, i + 1);
2845 return env_stack_push(env, var_type, var_type_id);
2848 type_id = var_type->type;
2849 if (!btf_type_id_size(btf, &type_id, &type_size)) {
2850 btf_verifier_log_vsi(env, v->t, vsi, "Invalid type");
2854 if (vsi->size < type_size) {
2855 btf_verifier_log_vsi(env, v->t, vsi, "Invalid size");
2860 env_stack_pop_resolved(env, 0, 0);
2864 static void btf_datasec_log(struct btf_verifier_env *env,
2865 const struct btf_type *t)
2867 btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
2870 static void btf_datasec_seq_show(const struct btf *btf,
2871 const struct btf_type *t, u32 type_id,
2872 void *data, u8 bits_offset,
2875 const struct btf_var_secinfo *vsi;
2876 const struct btf_type *var;
2879 seq_printf(m, "section (\"%s\") = {", __btf_name_by_offset(btf, t->name_off));
2880 for_each_vsi(i, t, vsi) {
2881 var = btf_type_by_id(btf, vsi->type);
2884 btf_type_ops(var)->seq_show(btf, var, vsi->type,
2885 data + vsi->offset, bits_offset, m);
2890 static const struct btf_kind_operations datasec_ops = {
2891 .check_meta = btf_datasec_check_meta,
2892 .resolve = btf_datasec_resolve,
2893 .check_member = btf_df_check_member,
2894 .check_kflag_member = btf_df_check_kflag_member,
2895 .log_details = btf_datasec_log,
2896 .seq_show = btf_datasec_seq_show,
2899 static int btf_func_proto_check(struct btf_verifier_env *env,
2900 const struct btf_type *t)
2902 const struct btf_type *ret_type;
2903 const struct btf_param *args;
2904 const struct btf *btf;
2909 args = (const struct btf_param *)(t + 1);
2910 nr_args = btf_type_vlen(t);
2912 /* Check func return type which could be "void" (t->type == 0) */
2914 u32 ret_type_id = t->type;
2916 ret_type = btf_type_by_id(btf, ret_type_id);
2918 btf_verifier_log_type(env, t, "Invalid return type");
2922 if (btf_type_needs_resolve(ret_type) &&
2923 !env_type_is_resolved(env, ret_type_id)) {
2924 err = btf_resolve(env, ret_type, ret_type_id);
2929 /* Ensure the return type is a type that has a size */
2930 if (!btf_type_id_size(btf, &ret_type_id, NULL)) {
2931 btf_verifier_log_type(env, t, "Invalid return type");
2939 /* Last func arg type_id could be 0 if it is a vararg */
2940 if (!args[nr_args - 1].type) {
2941 if (args[nr_args - 1].name_off) {
2942 btf_verifier_log_type(env, t, "Invalid arg#%u",
2950 for (i = 0; i < nr_args; i++) {
2951 const struct btf_type *arg_type;
2954 arg_type_id = args[i].type;
2955 arg_type = btf_type_by_id(btf, arg_type_id);
2957 btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
2962 if (args[i].name_off &&
2963 (!btf_name_offset_valid(btf, args[i].name_off) ||
2964 !btf_name_valid_identifier(btf, args[i].name_off))) {
2965 btf_verifier_log_type(env, t,
2966 "Invalid arg#%u", i + 1);
2971 if (btf_type_needs_resolve(arg_type) &&
2972 !env_type_is_resolved(env, arg_type_id)) {
2973 err = btf_resolve(env, arg_type, arg_type_id);
2978 if (!btf_type_id_size(btf, &arg_type_id, NULL)) {
2979 btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
2988 static int btf_func_check(struct btf_verifier_env *env,
2989 const struct btf_type *t)
2991 const struct btf_type *proto_type;
2992 const struct btf_param *args;
2993 const struct btf *btf;
2997 proto_type = btf_type_by_id(btf, t->type);
2999 if (!proto_type || !btf_type_is_func_proto(proto_type)) {
3000 btf_verifier_log_type(env, t, "Invalid type_id");
3004 args = (const struct btf_param *)(proto_type + 1);
3005 nr_args = btf_type_vlen(proto_type);
3006 for (i = 0; i < nr_args; i++) {
3007 if (!args[i].name_off && args[i].type) {
3008 btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
3016 static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = {
3017 [BTF_KIND_INT] = &int_ops,
3018 [BTF_KIND_PTR] = &ptr_ops,
3019 [BTF_KIND_ARRAY] = &array_ops,
3020 [BTF_KIND_STRUCT] = &struct_ops,
3021 [BTF_KIND_UNION] = &struct_ops,
3022 [BTF_KIND_ENUM] = &enum_ops,
3023 [BTF_KIND_FWD] = &fwd_ops,
3024 [BTF_KIND_TYPEDEF] = &modifier_ops,
3025 [BTF_KIND_VOLATILE] = &modifier_ops,
3026 [BTF_KIND_CONST] = &modifier_ops,
3027 [BTF_KIND_RESTRICT] = &modifier_ops,
3028 [BTF_KIND_FUNC] = &func_ops,
3029 [BTF_KIND_FUNC_PROTO] = &func_proto_ops,
3030 [BTF_KIND_VAR] = &var_ops,
3031 [BTF_KIND_DATASEC] = &datasec_ops,
3034 static s32 btf_check_meta(struct btf_verifier_env *env,
3035 const struct btf_type *t,
3038 u32 saved_meta_left = meta_left;
3041 if (meta_left < sizeof(*t)) {
3042 btf_verifier_log(env, "[%u] meta_left:%u meta_needed:%zu",
3043 env->log_type_id, meta_left, sizeof(*t));
3046 meta_left -= sizeof(*t);
3048 if (t->info & ~BTF_INFO_MASK) {
3049 btf_verifier_log(env, "[%u] Invalid btf_info:%x",
3050 env->log_type_id, t->info);
3054 if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX ||
3055 BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) {
3056 btf_verifier_log(env, "[%u] Invalid kind:%u",
3057 env->log_type_id, BTF_INFO_KIND(t->info));
3061 if (!btf_name_offset_valid(env->btf, t->name_off)) {
3062 btf_verifier_log(env, "[%u] Invalid name_offset:%u",
3063 env->log_type_id, t->name_off);
3067 var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left);
3068 if (var_meta_size < 0)
3069 return var_meta_size;
3071 meta_left -= var_meta_size;
3073 return saved_meta_left - meta_left;
3076 static int btf_check_all_metas(struct btf_verifier_env *env)
3078 struct btf *btf = env->btf;
3079 struct btf_header *hdr;
3083 cur = btf->nohdr_data + hdr->type_off;
3084 end = cur + hdr->type_len;
3086 env->log_type_id = 1;
3088 struct btf_type *t = cur;
3091 meta_size = btf_check_meta(env, t, end - cur);
3095 btf_add_type(env, t);
3103 static bool btf_resolve_valid(struct btf_verifier_env *env,
3104 const struct btf_type *t,
3107 struct btf *btf = env->btf;
3109 if (!env_type_is_resolved(env, type_id))
3112 if (btf_type_is_struct(t) || btf_type_is_datasec(t))
3113 return !btf->resolved_ids[type_id] &&
3114 !btf->resolved_sizes[type_id];
3116 if (btf_type_is_modifier(t) || btf_type_is_ptr(t) ||
3117 btf_type_is_var(t)) {
3118 t = btf_type_id_resolve(btf, &type_id);
3120 !btf_type_is_modifier(t) &&
3121 !btf_type_is_var(t) &&
3122 !btf_type_is_datasec(t);
3125 if (btf_type_is_array(t)) {
3126 const struct btf_array *array = btf_type_array(t);
3127 const struct btf_type *elem_type;
3128 u32 elem_type_id = array->type;
3131 elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size);
3132 return elem_type && !btf_type_is_modifier(elem_type) &&
3133 (array->nelems * elem_size ==
3134 btf->resolved_sizes[type_id]);
3140 static int btf_resolve(struct btf_verifier_env *env,
3141 const struct btf_type *t, u32 type_id)
3143 u32 save_log_type_id = env->log_type_id;
3144 const struct resolve_vertex *v;
3147 env->resolve_mode = RESOLVE_TBD;
3148 env_stack_push(env, t, type_id);
3149 while (!err && (v = env_stack_peak(env))) {
3150 env->log_type_id = v->type_id;
3151 err = btf_type_ops(v->t)->resolve(env, v);
3154 env->log_type_id = type_id;
3155 if (err == -E2BIG) {
3156 btf_verifier_log_type(env, t,
3157 "Exceeded max resolving depth:%u",
3159 } else if (err == -EEXIST) {
3160 btf_verifier_log_type(env, t, "Loop detected");
3163 /* Final sanity check */
3164 if (!err && !btf_resolve_valid(env, t, type_id)) {
3165 btf_verifier_log_type(env, t, "Invalid resolve state");
3169 env->log_type_id = save_log_type_id;
3173 static int btf_check_all_types(struct btf_verifier_env *env)
3175 struct btf *btf = env->btf;
3179 err = env_resolve_init(env);
3184 for (type_id = 1; type_id <= btf->nr_types; type_id++) {
3185 const struct btf_type *t = btf_type_by_id(btf, type_id);
3187 env->log_type_id = type_id;
3188 if (btf_type_needs_resolve(t) &&
3189 !env_type_is_resolved(env, type_id)) {
3190 err = btf_resolve(env, t, type_id);
3195 if (btf_type_is_func_proto(t)) {
3196 err = btf_func_proto_check(env, t);
3201 if (btf_type_is_func(t)) {
3202 err = btf_func_check(env, t);
3211 static int btf_parse_type_sec(struct btf_verifier_env *env)
3213 const struct btf_header *hdr = &env->btf->hdr;
3216 /* Type section must align to 4 bytes */
3217 if (hdr->type_off & (sizeof(u32) - 1)) {
3218 btf_verifier_log(env, "Unaligned type_off");
3222 if (!hdr->type_len) {
3223 btf_verifier_log(env, "No type found");
3227 err = btf_check_all_metas(env);
3231 return btf_check_all_types(env);
3234 static int btf_parse_str_sec(struct btf_verifier_env *env)
3236 const struct btf_header *hdr;
3237 struct btf *btf = env->btf;
3238 const char *start, *end;
3241 start = btf->nohdr_data + hdr->str_off;
3242 end = start + hdr->str_len;
3244 if (end != btf->data + btf->data_size) {
3245 btf_verifier_log(env, "String section is not at the end");
3249 if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET ||
3250 start[0] || end[-1]) {
3251 btf_verifier_log(env, "Invalid string section");
3255 btf->strings = start;
3260 static const size_t btf_sec_info_offset[] = {
3261 offsetof(struct btf_header, type_off),
3262 offsetof(struct btf_header, str_off),
3265 static int btf_sec_info_cmp(const void *a, const void *b)
3267 const struct btf_sec_info *x = a;
3268 const struct btf_sec_info *y = b;
3270 return (int)(x->off - y->off) ? : (int)(x->len - y->len);
3273 static int btf_check_sec_info(struct btf_verifier_env *env,
3276 struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)];
3277 u32 total, expected_total, i;
3278 const struct btf_header *hdr;
3279 const struct btf *btf;
3284 /* Populate the secs from hdr */
3285 for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++)
3286 secs[i] = *(struct btf_sec_info *)((void *)hdr +
3287 btf_sec_info_offset[i]);
3289 sort(secs, ARRAY_SIZE(btf_sec_info_offset),
3290 sizeof(struct btf_sec_info), btf_sec_info_cmp, NULL);
3292 /* Check for gaps and overlap among sections */
3294 expected_total = btf_data_size - hdr->hdr_len;
3295 for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) {
3296 if (expected_total < secs[i].off) {
3297 btf_verifier_log(env, "Invalid section offset");
3300 if (total < secs[i].off) {
3302 btf_verifier_log(env, "Unsupported section found");
3305 if (total > secs[i].off) {
3306 btf_verifier_log(env, "Section overlap found");
3309 if (expected_total - total < secs[i].len) {
3310 btf_verifier_log(env,
3311 "Total section length too long");
3314 total += secs[i].len;
3317 /* There is data other than hdr and known sections */
3318 if (expected_total != total) {
3319 btf_verifier_log(env, "Unsupported section found");
3326 static int btf_parse_hdr(struct btf_verifier_env *env)
3328 u32 hdr_len, hdr_copy, btf_data_size;
3329 const struct btf_header *hdr;
3334 btf_data_size = btf->data_size;
3337 offsetof(struct btf_header, hdr_len) + sizeof(hdr->hdr_len)) {
3338 btf_verifier_log(env, "hdr_len not found");
3343 hdr_len = hdr->hdr_len;
3344 if (btf_data_size < hdr_len) {
3345 btf_verifier_log(env, "btf_header not found");
3349 /* Ensure the unsupported header fields are zero */
3350 if (hdr_len > sizeof(btf->hdr)) {
3351 u8 *expected_zero = btf->data + sizeof(btf->hdr);
3352 u8 *end = btf->data + hdr_len;
3354 for (; expected_zero < end; expected_zero++) {
3355 if (*expected_zero) {
3356 btf_verifier_log(env, "Unsupported btf_header");
3362 hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr));
3363 memcpy(&btf->hdr, btf->data, hdr_copy);
3367 btf_verifier_log_hdr(env, btf_data_size);
3369 if (hdr->magic != BTF_MAGIC) {
3370 btf_verifier_log(env, "Invalid magic");
3374 if (hdr->version != BTF_VERSION) {
3375 btf_verifier_log(env, "Unsupported version");
3380 btf_verifier_log(env, "Unsupported flags");
3384 if (btf_data_size == hdr->hdr_len) {
3385 btf_verifier_log(env, "No data");
3389 err = btf_check_sec_info(env, btf_data_size);
3396 static struct btf *btf_parse(void __user *btf_data, u32 btf_data_size,
3397 u32 log_level, char __user *log_ubuf, u32 log_size)
3399 struct btf_verifier_env *env = NULL;
3400 struct bpf_verifier_log *log;
3401 struct btf *btf = NULL;
3405 if (btf_data_size > BTF_MAX_SIZE)
3406 return ERR_PTR(-E2BIG);
3408 env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
3410 return ERR_PTR(-ENOMEM);
3413 if (log_level || log_ubuf || log_size) {
3414 /* user requested verbose verifier output
3415 * and supplied buffer to store the verification trace
3417 log->level = log_level;
3418 log->ubuf = log_ubuf;
3419 log->len_total = log_size;
3421 /* log attributes have to be sane */
3422 if (log->len_total < 128 || log->len_total > UINT_MAX >> 8 ||
3423 !log->level || !log->ubuf) {
3429 btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN);
3436 data = kvmalloc(btf_data_size, GFP_KERNEL | __GFP_NOWARN);
3443 btf->data_size = btf_data_size;
3445 if (copy_from_user(data, btf_data, btf_data_size)) {
3450 err = btf_parse_hdr(env);
3454 btf->nohdr_data = btf->data + btf->hdr.hdr_len;
3456 err = btf_parse_str_sec(env);
3460 err = btf_parse_type_sec(env);
3464 if (log->level && bpf_verifier_log_full(log)) {
3469 btf_verifier_env_free(env);
3470 refcount_set(&btf->refcnt, 1);
3474 btf_verifier_env_free(env);
3477 return ERR_PTR(err);
3480 extern char __weak _binary__btf_vmlinux_bin_start[];
3481 extern char __weak _binary__btf_vmlinux_bin_end[];
3482 extern struct btf *btf_vmlinux;
3484 #define BPF_MAP_TYPE(_id, _ops)
3486 struct bpf_ctx_convert {
3487 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
3488 prog_ctx_type _id##_prog; \
3489 kern_ctx_type _id##_kern;
3490 #include <linux/bpf_types.h>
3491 #undef BPF_PROG_TYPE
3493 /* 't' is written once under lock. Read many times. */
3494 const struct btf_type *t;
3497 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
3499 #include <linux/bpf_types.h>
3500 #undef BPF_PROG_TYPE
3501 __ctx_convert_unused, /* to avoid empty enum in extreme .config */
3503 static u8 bpf_ctx_convert_map[] = {
3504 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
3505 [_id] = __ctx_convert##_id,
3506 #include <linux/bpf_types.h>
3507 #undef BPF_PROG_TYPE
3508 0, /* avoid empty array */
3512 static const struct btf_member *
3513 btf_get_prog_ctx_type(struct bpf_verifier_log *log, struct btf *btf,
3514 const struct btf_type *t, enum bpf_prog_type prog_type,
3517 const struct btf_type *conv_struct;
3518 const struct btf_type *ctx_struct;
3519 const struct btf_member *ctx_type;
3520 const char *tname, *ctx_tname;
3522 conv_struct = bpf_ctx_convert.t;
3524 bpf_log(log, "btf_vmlinux is malformed\n");
3527 t = btf_type_by_id(btf, t->type);
3528 while (btf_type_is_modifier(t))
3529 t = btf_type_by_id(btf, t->type);
3530 if (!btf_type_is_struct(t)) {
3531 /* Only pointer to struct is supported for now.
3532 * That means that BPF_PROG_TYPE_TRACEPOINT with BTF
3533 * is not supported yet.
3534 * BPF_PROG_TYPE_RAW_TRACEPOINT is fine.
3536 if (log->level & BPF_LOG_LEVEL)
3537 bpf_log(log, "arg#%d type is not a struct\n", arg);
3540 tname = btf_name_by_offset(btf, t->name_off);
3542 bpf_log(log, "arg#%d struct doesn't have a name\n", arg);
3545 /* prog_type is valid bpf program type. No need for bounds check. */
3546 ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2;
3547 /* ctx_struct is a pointer to prog_ctx_type in vmlinux.
3548 * Like 'struct __sk_buff'
3550 ctx_struct = btf_type_by_id(btf_vmlinux, ctx_type->type);
3552 /* should not happen */
3554 ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_struct->name_off);
3556 /* should not happen */
3557 bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n");
3560 /* only compare that prog's ctx type name is the same as
3561 * kernel expects. No need to compare field by field.
3562 * It's ok for bpf prog to do:
3563 * struct __sk_buff {};
3564 * int socket_filter_bpf_prog(struct __sk_buff *skb)
3565 * { // no fields of skb are ever used }
3567 if (strcmp(ctx_tname, tname))
3572 static int btf_translate_to_vmlinux(struct bpf_verifier_log *log,
3574 const struct btf_type *t,
3575 enum bpf_prog_type prog_type,
3578 const struct btf_member *prog_ctx_type, *kern_ctx_type;
3580 prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type, arg);
3583 kern_ctx_type = prog_ctx_type + 1;
3584 return kern_ctx_type->type;
3587 struct btf *btf_parse_vmlinux(void)
3589 struct btf_verifier_env *env = NULL;
3590 struct bpf_verifier_log *log;
3591 struct btf *btf = NULL;
3594 env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
3596 return ERR_PTR(-ENOMEM);
3599 log->level = BPF_LOG_KERNEL;
3601 btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN);
3608 btf->data = _binary__btf_vmlinux_bin_start;
3609 btf->data_size = _binary__btf_vmlinux_bin_end -
3610 _binary__btf_vmlinux_bin_start;
3612 err = btf_parse_hdr(env);
3616 btf->nohdr_data = btf->data + btf->hdr.hdr_len;
3618 err = btf_parse_str_sec(env);
3622 err = btf_check_all_metas(env);
3626 /* find struct bpf_ctx_convert for type checking later */
3627 for (i = 1; i <= btf->nr_types; i++) {
3628 const struct btf_type *t;
3631 t = btf_type_by_id(btf, i);
3632 if (!__btf_type_is_struct(t))
3634 tname = __btf_name_by_offset(btf, t->name_off);
3635 if (!strcmp(tname, "bpf_ctx_convert")) {
3636 /* btf_parse_vmlinux() runs under bpf_verifier_lock */
3637 bpf_ctx_convert.t = t;
3641 if (i > btf->nr_types) {
3646 bpf_struct_ops_init(btf, log);
3648 btf_verifier_env_free(env);
3649 refcount_set(&btf->refcnt, 1);
3653 btf_verifier_env_free(env);
3658 return ERR_PTR(err);
3661 struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog)
3663 struct bpf_prog *tgt_prog = prog->aux->linked_prog;
3666 return tgt_prog->aux->btf;
3672 static bool is_string_ptr(struct btf *btf, const struct btf_type *t)
3674 /* t comes in already as a pointer */
3675 t = btf_type_by_id(btf, t->type);
3678 if (BTF_INFO_KIND(t->info) == BTF_KIND_CONST)
3679 t = btf_type_by_id(btf, t->type);
3681 /* char, signed char, unsigned char */
3682 return btf_type_is_int(t) && t->size == 1;
3685 bool btf_ctx_access(int off, int size, enum bpf_access_type type,
3686 const struct bpf_prog *prog,
3687 struct bpf_insn_access_aux *info)
3689 const struct btf_type *t = prog->aux->attach_func_proto;
3690 struct bpf_prog *tgt_prog = prog->aux->linked_prog;
3691 struct btf *btf = bpf_prog_get_target_btf(prog);
3692 const char *tname = prog->aux->attach_func_name;
3693 struct bpf_verifier_log *log = info->log;
3694 const struct btf_param *args;
3699 bpf_log(log, "func '%s' offset %d is not multiple of 8\n",
3704 args = (const struct btf_param *)(t + 1);
3705 /* if (t == NULL) Fall back to default BPF prog with 5 u64 arguments */
3706 nr_args = t ? btf_type_vlen(t) : 5;
3707 if (prog->aux->attach_btf_trace) {
3708 /* skip first 'void *__data' argument in btf_trace_##name typedef */
3713 if (prog->expected_attach_type == BPF_TRACE_FEXIT &&
3716 /* Default prog with 5 args. 6th arg is retval. */
3718 /* function return type */
3719 t = btf_type_by_id(btf, t->type);
3720 } else if (arg >= nr_args) {
3721 bpf_log(log, "func '%s' doesn't have %d-th argument\n",
3726 /* Default prog with 5 args */
3728 t = btf_type_by_id(btf, args[arg].type);
3730 /* skip modifiers */
3731 while (btf_type_is_modifier(t))
3732 t = btf_type_by_id(btf, t->type);
3733 if (btf_type_is_int(t) || btf_type_is_enum(t))
3734 /* accessing a scalar */
3736 if (!btf_type_is_ptr(t)) {
3738 "func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n",
3740 __btf_name_by_offset(btf, t->name_off),
3741 btf_kind_str[BTF_INFO_KIND(t->info)]);
3745 /* This is a pointer to void.
3746 * It is the same as scalar from the verifier safety pov.
3747 * No further pointer walking is allowed.
3751 if (is_string_ptr(btf, t))
3754 /* this is a pointer to another type */
3755 info->reg_type = PTR_TO_BTF_ID;
3758 ret = btf_translate_to_vmlinux(log, btf, t, tgt_prog->type, arg);
3767 info->btf_id = t->type;
3768 t = btf_type_by_id(btf, t->type);
3769 /* skip modifiers */
3770 while (btf_type_is_modifier(t)) {
3771 info->btf_id = t->type;
3772 t = btf_type_by_id(btf, t->type);
3774 if (!btf_type_is_struct(t)) {
3776 "func '%s' arg%d type %s is not a struct\n",
3777 tname, arg, btf_kind_str[BTF_INFO_KIND(t->info)]);
3780 bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n",
3781 tname, arg, info->btf_id, btf_kind_str[BTF_INFO_KIND(t->info)],
3782 __btf_name_by_offset(btf, t->name_off));
3786 int btf_struct_access(struct bpf_verifier_log *log,
3787 const struct btf_type *t, int off, int size,
3788 enum bpf_access_type atype,
3791 u32 i, moff, mtrue_end, msize = 0, total_nelems = 0;
3792 const struct btf_type *mtype, *elem_type = NULL;
3793 const struct btf_member *member;
3794 const char *tname, *mname;
3797 tname = __btf_name_by_offset(btf_vmlinux, t->name_off);
3798 if (!btf_type_is_struct(t)) {
3799 bpf_log(log, "Type '%s' is not a struct\n", tname);
3803 if (off + size > t->size) {
3804 bpf_log(log, "access beyond struct %s at off %u size %u\n",
3809 for_each_member(i, t, member) {
3810 /* offset of the field in bytes */
3811 moff = btf_member_bit_offset(t, member) / 8;
3812 if (off + size <= moff)
3813 /* won't find anything, field is already too far */
3816 if (btf_member_bitfield_size(t, member)) {
3817 u32 end_bit = btf_member_bit_offset(t, member) +
3818 btf_member_bitfield_size(t, member);
3820 /* off <= moff instead of off == moff because clang
3821 * does not generate a BTF member for anonymous
3822 * bitfield like the ":16" here:
3829 BITS_ROUNDUP_BYTES(end_bit) <= off + size)
3830 return SCALAR_VALUE;
3832 /* off may be accessing a following member
3836 * Doing partial access at either end of this
3837 * bitfield. Continue on this case also to
3838 * treat it as not accessing this bitfield
3839 * and eventually error out as field not
3840 * found to keep it simple.
3841 * It could be relaxed if there was a legit
3842 * partial access case later.
3847 /* In case of "off" is pointing to holes of a struct */
3851 /* type of the field */
3852 mtype = btf_type_by_id(btf_vmlinux, member->type);
3853 mname = __btf_name_by_offset(btf_vmlinux, member->name_off);
3855 mtype = btf_resolve_size(btf_vmlinux, mtype, &msize,
3856 &elem_type, &total_nelems);
3857 if (IS_ERR(mtype)) {
3858 bpf_log(log, "field %s doesn't have size\n", mname);
3862 mtrue_end = moff + msize;
3863 if (off >= mtrue_end)
3864 /* no overlap with member, keep iterating */
3867 if (btf_type_is_array(mtype)) {
3870 /* btf_resolve_size() above helps to
3871 * linearize a multi-dimensional array.
3873 * The logic here is treating an array
3874 * in a struct as the following way:
3877 * struct inner array[2][2];
3883 * struct inner array_elem0;
3884 * struct inner array_elem1;
3885 * struct inner array_elem2;
3886 * struct inner array_elem3;
3889 * When accessing outer->array[1][0], it moves
3890 * moff to "array_elem2", set mtype to
3891 * "struct inner", and msize also becomes
3892 * sizeof(struct inner). Then most of the
3893 * remaining logic will fall through without
3894 * caring the current member is an array or
3897 * Unlike mtype/msize/moff, mtrue_end does not
3898 * change. The naming difference ("_true") tells
3899 * that it is not always corresponding to
3900 * the current mtype/msize/moff.
3901 * It is the true end of the current
3902 * member (i.e. array in this case). That
3903 * will allow an int array to be accessed like
3905 * i.e. allow access beyond the size of
3906 * the array's element as long as it is
3907 * within the mtrue_end boundary.
3910 /* skip empty array */
3911 if (moff == mtrue_end)
3914 msize /= total_nelems;
3915 elem_idx = (off - moff) / msize;
3916 moff += elem_idx * msize;
3920 /* the 'off' we're looking for is either equal to start
3921 * of this field or inside of this struct
3923 if (btf_type_is_struct(mtype)) {
3924 /* our field must be inside that union or struct */
3927 /* adjust offset we're looking for */
3932 if (btf_type_is_ptr(mtype)) {
3933 const struct btf_type *stype;
3936 if (msize != size || off != moff) {
3938 "cannot access ptr member %s with moff %u in struct %s with off %u size %u\n",
3939 mname, moff, tname, off, size);
3943 stype = btf_type_skip_modifiers(btf_vmlinux, mtype->type, &id);
3944 if (btf_type_is_struct(stype)) {
3946 return PTR_TO_BTF_ID;
3950 /* Allow more flexible access within an int as long as
3951 * it is within mtrue_end.
3952 * Since mtrue_end could be the end of an array,
3953 * that also allows using an array of int as a scratch
3954 * space. e.g. skb->cb[].
3956 if (off + size > mtrue_end) {
3958 "access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n",
3959 mname, mtrue_end, tname, off, size);
3963 return SCALAR_VALUE;
3965 bpf_log(log, "struct %s doesn't have field at offset %d\n", tname, off);
3969 static int __btf_resolve_helper_id(struct bpf_verifier_log *log, void *fn,
3972 char fnname[KSYM_SYMBOL_LEN + 4] = "btf_";
3973 const struct btf_param *args;
3974 const struct btf_type *t;
3975 const char *tname, *sym;
3978 if (IS_ERR(btf_vmlinux)) {
3979 bpf_log(log, "btf_vmlinux is malformed\n");
3983 sym = kallsyms_lookup((long)fn, NULL, NULL, NULL, fnname + 4);
3985 bpf_log(log, "kernel doesn't have kallsyms\n");
3989 for (i = 1; i <= btf_vmlinux->nr_types; i++) {
3990 t = btf_type_by_id(btf_vmlinux, i);
3991 if (BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF)
3993 tname = __btf_name_by_offset(btf_vmlinux, t->name_off);
3994 if (!strcmp(tname, fnname))
3997 if (i > btf_vmlinux->nr_types) {
3998 bpf_log(log, "helper %s type is not found\n", fnname);
4002 t = btf_type_by_id(btf_vmlinux, t->type);
4003 if (!btf_type_is_ptr(t))
4005 t = btf_type_by_id(btf_vmlinux, t->type);
4006 if (!btf_type_is_func_proto(t))
4009 args = (const struct btf_param *)(t + 1);
4010 if (arg >= btf_type_vlen(t)) {
4011 bpf_log(log, "bpf helper %s doesn't have %d-th argument\n",
4016 t = btf_type_by_id(btf_vmlinux, args[arg].type);
4017 if (!btf_type_is_ptr(t) || !t->type) {
4018 /* anything but the pointer to struct is a helper config bug */
4019 bpf_log(log, "ARG_PTR_TO_BTF is misconfigured\n");
4023 t = btf_type_by_id(btf_vmlinux, t->type);
4024 /* skip modifiers */
4025 while (btf_type_is_modifier(t)) {
4027 t = btf_type_by_id(btf_vmlinux, t->type);
4029 if (!btf_type_is_struct(t)) {
4030 bpf_log(log, "ARG_PTR_TO_BTF is not a struct\n");
4033 bpf_log(log, "helper %s arg%d has btf_id %d struct %s\n", fnname + 4,
4034 arg, btf_id, __btf_name_by_offset(btf_vmlinux, t->name_off));
4038 int btf_resolve_helper_id(struct bpf_verifier_log *log,
4039 const struct bpf_func_proto *fn, int arg)
4041 int *btf_id = &fn->btf_id[arg];
4044 if (fn->arg_type[arg] != ARG_PTR_TO_BTF_ID)
4047 ret = READ_ONCE(*btf_id);
4050 /* ok to race the search. The result is the same */
4051 ret = __btf_resolve_helper_id(log, fn->func, arg);
4053 /* Function argument cannot be type 'void' */
4054 bpf_log(log, "BTF resolution bug\n");
4057 WRITE_ONCE(*btf_id, ret);
4061 static int __get_type_size(struct btf *btf, u32 btf_id,
4062 const struct btf_type **bad_type)
4064 const struct btf_type *t;
4069 t = btf_type_by_id(btf, btf_id);
4070 while (t && btf_type_is_modifier(t))
4071 t = btf_type_by_id(btf, t->type);
4073 *bad_type = btf->types[0];
4076 if (btf_type_is_ptr(t))
4077 /* kernel size of pointer. Not BPF's size of pointer*/
4078 return sizeof(void *);
4079 if (btf_type_is_int(t) || btf_type_is_enum(t))
4085 int btf_distill_func_proto(struct bpf_verifier_log *log,
4087 const struct btf_type *func,
4089 struct btf_func_model *m)
4091 const struct btf_param *args;
4092 const struct btf_type *t;
4097 /* BTF function prototype doesn't match the verifier types.
4098 * Fall back to 5 u64 args.
4100 for (i = 0; i < 5; i++)
4106 args = (const struct btf_param *)(func + 1);
4107 nargs = btf_type_vlen(func);
4108 if (nargs >= MAX_BPF_FUNC_ARGS) {
4110 "The function %s has %d arguments. Too many.\n",
4114 ret = __get_type_size(btf, func->type, &t);
4117 "The function %s return type %s is unsupported.\n",
4118 tname, btf_kind_str[BTF_INFO_KIND(t->info)]);
4123 for (i = 0; i < nargs; i++) {
4124 ret = __get_type_size(btf, args[i].type, &t);
4127 "The function %s arg%d type %s is unsupported.\n",
4128 tname, i, btf_kind_str[BTF_INFO_KIND(t->info)]);
4131 m->arg_size[i] = ret;
4137 /* Compare BTFs of two functions assuming only scalars and pointers to context.
4138 * t1 points to BTF_KIND_FUNC in btf1
4139 * t2 points to BTF_KIND_FUNC in btf2
4141 * EINVAL - function prototype mismatch
4142 * EFAULT - verifier bug
4143 * 0 - 99% match. The last 1% is validated by the verifier.
4145 static int btf_check_func_type_match(struct bpf_verifier_log *log,
4146 struct btf *btf1, const struct btf_type *t1,
4147 struct btf *btf2, const struct btf_type *t2)
4149 const struct btf_param *args1, *args2;
4150 const char *fn1, *fn2, *s1, *s2;
4151 u32 nargs1, nargs2, i;
4153 fn1 = btf_name_by_offset(btf1, t1->name_off);
4154 fn2 = btf_name_by_offset(btf2, t2->name_off);
4156 if (btf_func_linkage(t1) != BTF_FUNC_GLOBAL) {
4157 bpf_log(log, "%s() is not a global function\n", fn1);
4160 if (btf_func_linkage(t2) != BTF_FUNC_GLOBAL) {
4161 bpf_log(log, "%s() is not a global function\n", fn2);
4165 t1 = btf_type_by_id(btf1, t1->type);
4166 if (!t1 || !btf_type_is_func_proto(t1))
4168 t2 = btf_type_by_id(btf2, t2->type);
4169 if (!t2 || !btf_type_is_func_proto(t2))
4172 args1 = (const struct btf_param *)(t1 + 1);
4173 nargs1 = btf_type_vlen(t1);
4174 args2 = (const struct btf_param *)(t2 + 1);
4175 nargs2 = btf_type_vlen(t2);
4177 if (nargs1 != nargs2) {
4178 bpf_log(log, "%s() has %d args while %s() has %d args\n",
4179 fn1, nargs1, fn2, nargs2);
4183 t1 = btf_type_skip_modifiers(btf1, t1->type, NULL);
4184 t2 = btf_type_skip_modifiers(btf2, t2->type, NULL);
4185 if (t1->info != t2->info) {
4187 "Return type %s of %s() doesn't match type %s of %s()\n",
4188 btf_type_str(t1), fn1,
4189 btf_type_str(t2), fn2);
4193 for (i = 0; i < nargs1; i++) {
4194 t1 = btf_type_skip_modifiers(btf1, args1[i].type, NULL);
4195 t2 = btf_type_skip_modifiers(btf2, args2[i].type, NULL);
4197 if (t1->info != t2->info) {
4198 bpf_log(log, "arg%d in %s() is %s while %s() has %s\n",
4199 i, fn1, btf_type_str(t1),
4200 fn2, btf_type_str(t2));
4203 if (btf_type_has_size(t1) && t1->size != t2->size) {
4205 "arg%d in %s() has size %d while %s() has %d\n",
4211 /* global functions are validated with scalars and pointers
4212 * to context only. And only global functions can be replaced.
4213 * Hence type check only those types.
4215 if (btf_type_is_int(t1) || btf_type_is_enum(t1))
4217 if (!btf_type_is_ptr(t1)) {
4219 "arg%d in %s() has unrecognized type\n",
4223 t1 = btf_type_skip_modifiers(btf1, t1->type, NULL);
4224 t2 = btf_type_skip_modifiers(btf2, t2->type, NULL);
4225 if (!btf_type_is_struct(t1)) {
4227 "arg%d in %s() is not a pointer to context\n",
4231 if (!btf_type_is_struct(t2)) {
4233 "arg%d in %s() is not a pointer to context\n",
4237 /* This is an optional check to make program writing easier.
4238 * Compare names of structs and report an error to the user.
4239 * btf_prepare_func_args() already checked that t2 struct
4240 * is a context type. btf_prepare_func_args() will check
4241 * later that t1 struct is a context type as well.
4243 s1 = btf_name_by_offset(btf1, t1->name_off);
4244 s2 = btf_name_by_offset(btf2, t2->name_off);
4245 if (strcmp(s1, s2)) {
4247 "arg%d %s(struct %s *) doesn't match %s(struct %s *)\n",
4248 i, fn1, s1, fn2, s2);
4255 /* Compare BTFs of given program with BTF of target program */
4256 int btf_check_type_match(struct bpf_verifier_env *env, struct bpf_prog *prog,
4257 struct btf *btf2, const struct btf_type *t2)
4259 struct btf *btf1 = prog->aux->btf;
4260 const struct btf_type *t1;
4263 if (!prog->aux->func_info) {
4264 bpf_log(&env->log, "Program extension requires BTF\n");
4268 btf_id = prog->aux->func_info[0].type_id;
4272 t1 = btf_type_by_id(btf1, btf_id);
4273 if (!t1 || !btf_type_is_func(t1))
4276 return btf_check_func_type_match(&env->log, btf1, t1, btf2, t2);
4279 /* Compare BTF of a function with given bpf_reg_state.
4281 * EFAULT - there is a verifier bug. Abort verification.
4282 * EINVAL - there is a type mismatch or BTF is not available.
4283 * 0 - BTF matches with what bpf_reg_state expects.
4284 * Only PTR_TO_CTX and SCALAR_VALUE states are recognized.
4286 int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog,
4287 struct bpf_reg_state *reg)
4289 struct bpf_verifier_log *log = &env->log;
4290 struct bpf_prog *prog = env->prog;
4291 struct btf *btf = prog->aux->btf;
4292 const struct btf_param *args;
4293 const struct btf_type *t;
4294 u32 i, nargs, btf_id;
4297 if (!prog->aux->func_info)
4300 btf_id = prog->aux->func_info[subprog].type_id;
4304 if (prog->aux->func_info_aux[subprog].unreliable)
4307 t = btf_type_by_id(btf, btf_id);
4308 if (!t || !btf_type_is_func(t)) {
4309 /* These checks were already done by the verifier while loading
4310 * struct bpf_func_info
4312 bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n",
4316 tname = btf_name_by_offset(btf, t->name_off);
4318 t = btf_type_by_id(btf, t->type);
4319 if (!t || !btf_type_is_func_proto(t)) {
4320 bpf_log(log, "Invalid BTF of func %s\n", tname);
4323 args = (const struct btf_param *)(t + 1);
4324 nargs = btf_type_vlen(t);
4326 bpf_log(log, "Function %s has %d > 5 args\n", tname, nargs);
4329 /* check that BTF function arguments match actual types that the
4332 for (i = 0; i < nargs; i++) {
4333 t = btf_type_by_id(btf, args[i].type);
4334 while (btf_type_is_modifier(t))
4335 t = btf_type_by_id(btf, t->type);
4336 if (btf_type_is_int(t) || btf_type_is_enum(t)) {
4337 if (reg[i + 1].type == SCALAR_VALUE)
4339 bpf_log(log, "R%d is not a scalar\n", i + 1);
4342 if (btf_type_is_ptr(t)) {
4343 if (reg[i + 1].type == SCALAR_VALUE) {
4344 bpf_log(log, "R%d is not a pointer\n", i + 1);
4347 /* If function expects ctx type in BTF check that caller
4348 * is passing PTR_TO_CTX.
4350 if (btf_get_prog_ctx_type(log, btf, t, prog->type, i)) {
4351 if (reg[i + 1].type != PTR_TO_CTX) {
4353 "arg#%d expected pointer to ctx, but got %s\n",
4354 i, btf_kind_str[BTF_INFO_KIND(t->info)]);
4357 if (check_ctx_reg(env, ®[i + 1], i + 1))
4362 bpf_log(log, "Unrecognized arg#%d type %s\n",
4363 i, btf_kind_str[BTF_INFO_KIND(t->info)]);
4368 /* Compiler optimizations can remove arguments from static functions
4369 * or mismatched type can be passed into a global function.
4370 * In such cases mark the function as unreliable from BTF point of view.
4372 prog->aux->func_info_aux[subprog].unreliable = true;
4376 /* Convert BTF of a function into bpf_reg_state if possible
4378 * EFAULT - there is a verifier bug. Abort verification.
4379 * EINVAL - cannot convert BTF.
4380 * 0 - Successfully converted BTF into bpf_reg_state
4381 * (either PTR_TO_CTX or SCALAR_VALUE).
4383 int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
4384 struct bpf_reg_state *reg)
4386 struct bpf_verifier_log *log = &env->log;
4387 struct bpf_prog *prog = env->prog;
4388 enum bpf_prog_type prog_type = prog->type;
4389 struct btf *btf = prog->aux->btf;
4390 const struct btf_param *args;
4391 const struct btf_type *t;
4392 u32 i, nargs, btf_id;
4395 if (!prog->aux->func_info ||
4396 prog->aux->func_info_aux[subprog].linkage != BTF_FUNC_GLOBAL) {
4397 bpf_log(log, "Verifier bug\n");
4401 btf_id = prog->aux->func_info[subprog].type_id;
4403 bpf_log(log, "Global functions need valid BTF\n");
4407 t = btf_type_by_id(btf, btf_id);
4408 if (!t || !btf_type_is_func(t)) {
4409 /* These checks were already done by the verifier while loading
4410 * struct bpf_func_info
4412 bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n",
4416 tname = btf_name_by_offset(btf, t->name_off);
4418 if (log->level & BPF_LOG_LEVEL)
4419 bpf_log(log, "Validating %s() func#%d...\n",
4422 if (prog->aux->func_info_aux[subprog].unreliable) {
4423 bpf_log(log, "Verifier bug in function %s()\n", tname);
4426 if (prog_type == BPF_PROG_TYPE_EXT)
4427 prog_type = prog->aux->linked_prog->type;
4429 t = btf_type_by_id(btf, t->type);
4430 if (!t || !btf_type_is_func_proto(t)) {
4431 bpf_log(log, "Invalid type of function %s()\n", tname);
4434 args = (const struct btf_param *)(t + 1);
4435 nargs = btf_type_vlen(t);
4437 bpf_log(log, "Global function %s() with %d > 5 args. Buggy compiler.\n",
4441 /* check that function returns int */
4442 t = btf_type_by_id(btf, t->type);
4443 while (btf_type_is_modifier(t))
4444 t = btf_type_by_id(btf, t->type);
4445 if (!btf_type_is_int(t) && !btf_type_is_enum(t)) {
4447 "Global function %s() doesn't return scalar. Only those are supported.\n",
4451 /* Convert BTF function arguments into verifier types.
4452 * Only PTR_TO_CTX and SCALAR are supported atm.
4454 for (i = 0; i < nargs; i++) {
4455 t = btf_type_by_id(btf, args[i].type);
4456 while (btf_type_is_modifier(t))
4457 t = btf_type_by_id(btf, t->type);
4458 if (btf_type_is_int(t) || btf_type_is_enum(t)) {
4459 reg[i + 1].type = SCALAR_VALUE;
4462 if (btf_type_is_ptr(t) &&
4463 btf_get_prog_ctx_type(log, btf, t, prog_type, i)) {
4464 reg[i + 1].type = PTR_TO_CTX;
4467 bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n",
4468 i, btf_kind_str[BTF_INFO_KIND(t->info)], tname);
4474 void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
4477 const struct btf_type *t = btf_type_by_id(btf, type_id);
4479 btf_type_ops(t)->seq_show(btf, t, type_id, obj, 0, m);
4482 #ifdef CONFIG_PROC_FS
4483 static void bpf_btf_show_fdinfo(struct seq_file *m, struct file *filp)
4485 const struct btf *btf = filp->private_data;
4487 seq_printf(m, "btf_id:\t%u\n", btf->id);
4491 static int btf_release(struct inode *inode, struct file *filp)
4493 btf_put(filp->private_data);
4497 const struct file_operations btf_fops = {
4498 #ifdef CONFIG_PROC_FS
4499 .show_fdinfo = bpf_btf_show_fdinfo,
4501 .release = btf_release,
4504 static int __btf_new_fd(struct btf *btf)
4506 return anon_inode_getfd("btf", &btf_fops, btf, O_RDONLY | O_CLOEXEC);
4509 int btf_new_fd(const union bpf_attr *attr)
4514 btf = btf_parse(u64_to_user_ptr(attr->btf),
4515 attr->btf_size, attr->btf_log_level,
4516 u64_to_user_ptr(attr->btf_log_buf),
4517 attr->btf_log_size);
4519 return PTR_ERR(btf);
4521 ret = btf_alloc_id(btf);
4528 * The BTF ID is published to the userspace.
4529 * All BTF free must go through call_rcu() from
4530 * now on (i.e. free by calling btf_put()).
4533 ret = __btf_new_fd(btf);
4540 struct btf *btf_get_by_fd(int fd)
4548 return ERR_PTR(-EBADF);
4550 if (f.file->f_op != &btf_fops) {
4552 return ERR_PTR(-EINVAL);
4555 btf = f.file->private_data;
4556 refcount_inc(&btf->refcnt);
4562 int btf_get_info_by_fd(const struct btf *btf,
4563 const union bpf_attr *attr,
4564 union bpf_attr __user *uattr)
4566 struct bpf_btf_info __user *uinfo;
4567 struct bpf_btf_info info;
4568 u32 info_copy, btf_copy;
4572 uinfo = u64_to_user_ptr(attr->info.info);
4573 uinfo_len = attr->info.info_len;
4575 info_copy = min_t(u32, uinfo_len, sizeof(info));
4576 memset(&info, 0, sizeof(info));
4577 if (copy_from_user(&info, uinfo, info_copy))
4581 ubtf = u64_to_user_ptr(info.btf);
4582 btf_copy = min_t(u32, btf->data_size, info.btf_size);
4583 if (copy_to_user(ubtf, btf->data, btf_copy))
4585 info.btf_size = btf->data_size;
4587 if (copy_to_user(uinfo, &info, info_copy) ||
4588 put_user(info_copy, &uattr->info.info_len))
4594 int btf_get_fd_by_id(u32 id)
4600 btf = idr_find(&btf_idr, id);
4601 if (!btf || !refcount_inc_not_zero(&btf->refcnt))
4602 btf = ERR_PTR(-ENOENT);
4606 return PTR_ERR(btf);
4608 fd = __btf_new_fd(btf);
4615 u32 btf_id(const struct btf *btf)