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/btf_ids.h>
22 #include <linux/skmsg.h>
23 #include <linux/perf_event.h>
24 #include <linux/bsearch.h>
25 #include <linux/kobject.h>
26 #include <linux/sysfs.h>
28 #include "../tools/lib/bpf/relo_core.h"
30 /* BTF (BPF Type Format) is the meta data format which describes
31 * the data types of BPF program/map. Hence, it basically focus
32 * on the C programming language which the modern BPF is primary
37 * The BTF data is stored under the ".BTF" ELF section
41 * Each 'struct btf_type' object describes a C data type.
42 * Depending on the type it is describing, a 'struct btf_type'
43 * object may be followed by more data. F.e.
44 * To describe an array, 'struct btf_type' is followed by
47 * 'struct btf_type' and any extra data following it are
52 * The BTF type section contains a list of 'struct btf_type' objects.
53 * Each one describes a C type. Recall from the above section
54 * that a 'struct btf_type' object could be immediately followed by extra
55 * data in order to describe some particular C types.
59 * Each btf_type object is identified by a type_id. The type_id
60 * is implicitly implied by the location of the btf_type object in
61 * the BTF type section. The first one has type_id 1. The second
62 * one has type_id 2...etc. Hence, an earlier btf_type has
65 * A btf_type object may refer to another btf_type object by using
66 * type_id (i.e. the "type" in the "struct btf_type").
68 * NOTE that we cannot assume any reference-order.
69 * A btf_type object can refer to an earlier btf_type object
70 * but it can also refer to a later btf_type object.
72 * For example, to describe "const void *". A btf_type
73 * object describing "const" may refer to another btf_type
74 * object describing "void *". This type-reference is done
75 * by specifying type_id:
77 * [1] CONST (anon) type_id=2
78 * [2] PTR (anon) type_id=0
80 * The above is the btf_verifier debug log:
81 * - Each line started with "[?]" is a btf_type object
82 * - [?] is the type_id of the btf_type object.
83 * - CONST/PTR is the BTF_KIND_XXX
84 * - "(anon)" is the name of the type. It just
85 * happens that CONST and PTR has no name.
86 * - type_id=XXX is the 'u32 type' in btf_type
88 * NOTE: "void" has type_id 0
92 * The BTF string section contains the names used by the type section.
93 * Each string is referred by an "offset" from the beginning of the
96 * Each string is '\0' terminated.
98 * The first character in the string section must be '\0'
99 * which is used to mean 'anonymous'. Some btf_type may not
105 * To verify BTF data, two passes are needed.
109 * The first pass is to collect all btf_type objects to
110 * an array: "btf->types".
112 * Depending on the C type that a btf_type is describing,
113 * a btf_type may be followed by extra data. We don't know
114 * how many btf_type is there, and more importantly we don't
115 * know where each btf_type is located in the type section.
117 * Without knowing the location of each type_id, most verifications
118 * cannot be done. e.g. an earlier btf_type may refer to a later
119 * btf_type (recall the "const void *" above), so we cannot
120 * check this type-reference in the first pass.
122 * In the first pass, it still does some verifications (e.g.
123 * checking the name is a valid offset to the string section).
127 * The main focus is to resolve a btf_type that is referring
130 * We have to ensure the referring type:
131 * 1) does exist in the BTF (i.e. in btf->types[])
132 * 2) does not cause a loop:
141 * btf_type_needs_resolve() decides if a btf_type needs
144 * The needs_resolve type implements the "resolve()" ops which
145 * essentially does a DFS and detects backedge.
147 * During resolve (or DFS), different C types have different
148 * "RESOLVED" conditions.
150 * When resolving a BTF_KIND_STRUCT, we need to resolve all its
151 * members because a member is always referring to another
152 * type. A struct's member can be treated as "RESOLVED" if
153 * it is referring to a BTF_KIND_PTR. Otherwise, the
154 * following valid C struct would be rejected:
161 * When resolving a BTF_KIND_PTR, it needs to keep resolving if
162 * it is referring to another BTF_KIND_PTR. Otherwise, we cannot
163 * detect a pointer loop, e.g.:
164 * BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR +
166 * +-----------------------------------------+
170 #define BITS_PER_U128 (sizeof(u64) * BITS_PER_BYTE * 2)
171 #define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1)
172 #define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK)
173 #define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3)
174 #define BITS_ROUNDUP_BYTES(bits) \
175 (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits))
177 #define BTF_INFO_MASK 0x9f00ffff
178 #define BTF_INT_MASK 0x0fffffff
179 #define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE)
180 #define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET)
182 /* 16MB for 64k structs and each has 16 members and
183 * a few MB spaces for the string section.
184 * The hard limit is S32_MAX.
186 #define BTF_MAX_SIZE (16 * 1024 * 1024)
188 #define for_each_member_from(i, from, struct_type, member) \
189 for (i = from, member = btf_type_member(struct_type) + from; \
190 i < btf_type_vlen(struct_type); \
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);
201 enum btf_kfunc_hook {
204 BTF_KFUNC_HOOK_STRUCT_OPS,
205 BTF_KFUNC_HOOK_TRACING,
206 BTF_KFUNC_HOOK_SYSCALL,
211 BTF_KFUNC_SET_MAX_CNT = 32,
212 BTF_DTOR_KFUNC_MAX_CNT = 256,
215 struct btf_kfunc_set_tab {
216 struct btf_id_set *sets[BTF_KFUNC_HOOK_MAX][BTF_KFUNC_TYPE_MAX];
219 struct btf_id_dtor_kfunc_tab {
221 struct btf_id_dtor_kfunc dtors[];
226 struct btf_type **types;
231 struct btf_header hdr;
232 u32 nr_types; /* includes VOID for base BTF */
238 struct btf_kfunc_set_tab *kfunc_set_tab;
239 struct btf_id_dtor_kfunc_tab *dtor_kfunc_tab;
241 /* split BTF support */
242 struct btf *base_btf;
243 u32 start_id; /* first type ID in this BTF (0 for base BTF) */
244 u32 start_str_off; /* first string offset (0 for base BTF) */
245 char name[MODULE_NAME_LEN];
249 enum verifier_phase {
254 struct resolve_vertex {
255 const struct btf_type *t;
267 RESOLVE_TBD, /* To Be Determined */
268 RESOLVE_PTR, /* Resolving for Pointer */
269 RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union
274 #define MAX_RESOLVE_DEPTH 32
276 struct btf_sec_info {
281 struct btf_verifier_env {
284 struct resolve_vertex stack[MAX_RESOLVE_DEPTH];
285 struct bpf_verifier_log log;
288 enum verifier_phase phase;
289 enum resolve_mode resolve_mode;
292 static const char * const btf_kind_str[NR_BTF_KINDS] = {
293 [BTF_KIND_UNKN] = "UNKNOWN",
294 [BTF_KIND_INT] = "INT",
295 [BTF_KIND_PTR] = "PTR",
296 [BTF_KIND_ARRAY] = "ARRAY",
297 [BTF_KIND_STRUCT] = "STRUCT",
298 [BTF_KIND_UNION] = "UNION",
299 [BTF_KIND_ENUM] = "ENUM",
300 [BTF_KIND_FWD] = "FWD",
301 [BTF_KIND_TYPEDEF] = "TYPEDEF",
302 [BTF_KIND_VOLATILE] = "VOLATILE",
303 [BTF_KIND_CONST] = "CONST",
304 [BTF_KIND_RESTRICT] = "RESTRICT",
305 [BTF_KIND_FUNC] = "FUNC",
306 [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO",
307 [BTF_KIND_VAR] = "VAR",
308 [BTF_KIND_DATASEC] = "DATASEC",
309 [BTF_KIND_FLOAT] = "FLOAT",
310 [BTF_KIND_DECL_TAG] = "DECL_TAG",
311 [BTF_KIND_TYPE_TAG] = "TYPE_TAG",
312 [BTF_KIND_ENUM64] = "ENUM64",
315 const char *btf_type_str(const struct btf_type *t)
317 return btf_kind_str[BTF_INFO_KIND(t->info)];
320 /* Chunk size we use in safe copy of data to be shown. */
321 #define BTF_SHOW_OBJ_SAFE_SIZE 32
324 * This is the maximum size of a base type value (equivalent to a
325 * 128-bit int); if we are at the end of our safe buffer and have
326 * less than 16 bytes space we can't be assured of being able
327 * to copy the next type safely, so in such cases we will initiate
330 #define BTF_SHOW_OBJ_BASE_TYPE_SIZE 16
333 #define BTF_SHOW_NAME_SIZE 80
336 * Common data to all BTF show operations. Private show functions can add
337 * their own data to a structure containing a struct btf_show and consult it
338 * in the show callback. See btf_type_show() below.
340 * One challenge with showing nested data is we want to skip 0-valued
341 * data, but in order to figure out whether a nested object is all zeros
342 * we need to walk through it. As a result, we need to make two passes
343 * when handling structs, unions and arrays; the first path simply looks
344 * for nonzero data, while the second actually does the display. The first
345 * pass is signalled by show->state.depth_check being set, and if we
346 * encounter a non-zero value we set show->state.depth_to_show to
347 * the depth at which we encountered it. When we have completed the
348 * first pass, we will know if anything needs to be displayed if
349 * depth_to_show > depth. See btf_[struct,array]_show() for the
350 * implementation of this.
352 * Another problem is we want to ensure the data for display is safe to
353 * access. To support this, the anonymous "struct {} obj" tracks the data
354 * object and our safe copy of it. We copy portions of the data needed
355 * to the object "copy" buffer, but because its size is limited to
356 * BTF_SHOW_OBJ_COPY_LEN bytes, multiple copies may be required as we
357 * traverse larger objects for display.
359 * The various data type show functions all start with a call to
360 * btf_show_start_type() which returns a pointer to the safe copy
361 * of the data needed (or if BTF_SHOW_UNSAFE is specified, to the
362 * raw data itself). btf_show_obj_safe() is responsible for
363 * using copy_from_kernel_nofault() to update the safe data if necessary
364 * as we traverse the object's data. skbuff-like semantics are
367 * - obj.head points to the start of the toplevel object for display
368 * - obj.size is the size of the toplevel object
369 * - obj.data points to the current point in the original data at
370 * which our safe data starts. obj.data will advance as we copy
371 * portions of the data.
373 * In most cases a single copy will suffice, but larger data structures
374 * such as "struct task_struct" will require many copies. The logic in
375 * btf_show_obj_safe() handles the logic that determines if a new
376 * copy_from_kernel_nofault() is needed.
380 void *target; /* target of show operation (seq file, buffer) */
381 void (*showfn)(struct btf_show *show, const char *fmt, va_list args);
382 const struct btf *btf;
383 /* below are used during iteration */
392 int status; /* non-zero for error */
393 const struct btf_type *type;
394 const struct btf_member *member;
395 char name[BTF_SHOW_NAME_SIZE]; /* space for member name/type */
401 u8 safe[BTF_SHOW_OBJ_SAFE_SIZE];
405 struct btf_kind_operations {
406 s32 (*check_meta)(struct btf_verifier_env *env,
407 const struct btf_type *t,
409 int (*resolve)(struct btf_verifier_env *env,
410 const struct resolve_vertex *v);
411 int (*check_member)(struct btf_verifier_env *env,
412 const struct btf_type *struct_type,
413 const struct btf_member *member,
414 const struct btf_type *member_type);
415 int (*check_kflag_member)(struct btf_verifier_env *env,
416 const struct btf_type *struct_type,
417 const struct btf_member *member,
418 const struct btf_type *member_type);
419 void (*log_details)(struct btf_verifier_env *env,
420 const struct btf_type *t);
421 void (*show)(const struct btf *btf, const struct btf_type *t,
422 u32 type_id, void *data, u8 bits_offsets,
423 struct btf_show *show);
426 static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS];
427 static struct btf_type btf_void;
429 static int btf_resolve(struct btf_verifier_env *env,
430 const struct btf_type *t, u32 type_id);
432 static int btf_func_check(struct btf_verifier_env *env,
433 const struct btf_type *t);
435 static bool btf_type_is_modifier(const struct btf_type *t)
437 /* Some of them is not strictly a C modifier
438 * but they are grouped into the same bucket
440 * A type (t) that refers to another
441 * type through t->type AND its size cannot
442 * be determined without following the t->type.
444 * ptr does not fall into this bucket
445 * because its size is always sizeof(void *).
447 switch (BTF_INFO_KIND(t->info)) {
448 case BTF_KIND_TYPEDEF:
449 case BTF_KIND_VOLATILE:
451 case BTF_KIND_RESTRICT:
452 case BTF_KIND_TYPE_TAG:
459 bool btf_type_is_void(const struct btf_type *t)
461 return t == &btf_void;
464 static bool btf_type_is_fwd(const struct btf_type *t)
466 return BTF_INFO_KIND(t->info) == BTF_KIND_FWD;
469 static bool btf_type_nosize(const struct btf_type *t)
471 return btf_type_is_void(t) || btf_type_is_fwd(t) ||
472 btf_type_is_func(t) || btf_type_is_func_proto(t);
475 static bool btf_type_nosize_or_null(const struct btf_type *t)
477 return !t || btf_type_nosize(t);
480 static bool __btf_type_is_struct(const struct btf_type *t)
482 return BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT;
485 static bool btf_type_is_array(const struct btf_type *t)
487 return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY;
490 static bool btf_type_is_datasec(const struct btf_type *t)
492 return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC;
495 static bool btf_type_is_decl_tag(const struct btf_type *t)
497 return BTF_INFO_KIND(t->info) == BTF_KIND_DECL_TAG;
500 static bool btf_type_is_decl_tag_target(const struct btf_type *t)
502 return btf_type_is_func(t) || btf_type_is_struct(t) ||
503 btf_type_is_var(t) || btf_type_is_typedef(t);
506 u32 btf_nr_types(const struct btf *btf)
511 total += btf->nr_types;
518 s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind)
520 const struct btf_type *t;
524 total = btf_nr_types(btf);
525 for (i = 1; i < total; i++) {
526 t = btf_type_by_id(btf, i);
527 if (BTF_INFO_KIND(t->info) != kind)
530 tname = btf_name_by_offset(btf, t->name_off);
531 if (!strcmp(tname, name))
538 static s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p)
544 btf = bpf_get_btf_vmlinux();
550 ret = btf_find_by_name_kind(btf, name, kind);
551 /* ret is never zero, since btf_find_by_name_kind returns
552 * positive btf_id or negative error.
560 /* If name is not found in vmlinux's BTF then search in module's BTFs */
561 spin_lock_bh(&btf_idr_lock);
562 idr_for_each_entry(&btf_idr, btf, id) {
563 if (!btf_is_module(btf))
565 /* linear search could be slow hence unlock/lock
566 * the IDR to avoiding holding it for too long
569 spin_unlock_bh(&btf_idr_lock);
570 ret = btf_find_by_name_kind(btf, name, kind);
575 spin_lock_bh(&btf_idr_lock);
578 spin_unlock_bh(&btf_idr_lock);
582 const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
585 const struct btf_type *t = btf_type_by_id(btf, id);
587 while (btf_type_is_modifier(t)) {
589 t = btf_type_by_id(btf, t->type);
598 const struct btf_type *btf_type_resolve_ptr(const struct btf *btf,
601 const struct btf_type *t;
603 t = btf_type_skip_modifiers(btf, id, NULL);
604 if (!btf_type_is_ptr(t))
607 return btf_type_skip_modifiers(btf, t->type, res_id);
610 const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
613 const struct btf_type *ptype;
615 ptype = btf_type_resolve_ptr(btf, id, res_id);
616 if (ptype && btf_type_is_func_proto(ptype))
622 /* Types that act only as a source, not sink or intermediate
623 * type when resolving.
625 static bool btf_type_is_resolve_source_only(const struct btf_type *t)
627 return btf_type_is_var(t) ||
628 btf_type_is_decl_tag(t) ||
629 btf_type_is_datasec(t);
632 /* What types need to be resolved?
634 * btf_type_is_modifier() is an obvious one.
636 * btf_type_is_struct() because its member refers to
637 * another type (through member->type).
639 * btf_type_is_var() because the variable refers to
640 * another type. btf_type_is_datasec() holds multiple
641 * btf_type_is_var() types that need resolving.
643 * btf_type_is_array() because its element (array->type)
644 * refers to another type. Array can be thought of a
645 * special case of struct while array just has the same
646 * member-type repeated by array->nelems of times.
648 static bool btf_type_needs_resolve(const struct btf_type *t)
650 return btf_type_is_modifier(t) ||
651 btf_type_is_ptr(t) ||
652 btf_type_is_struct(t) ||
653 btf_type_is_array(t) ||
654 btf_type_is_var(t) ||
655 btf_type_is_func(t) ||
656 btf_type_is_decl_tag(t) ||
657 btf_type_is_datasec(t);
660 /* t->size can be used */
661 static bool btf_type_has_size(const struct btf_type *t)
663 switch (BTF_INFO_KIND(t->info)) {
665 case BTF_KIND_STRUCT:
668 case BTF_KIND_DATASEC:
670 case BTF_KIND_ENUM64:
677 static const char *btf_int_encoding_str(u8 encoding)
681 else if (encoding == BTF_INT_SIGNED)
683 else if (encoding == BTF_INT_CHAR)
685 else if (encoding == BTF_INT_BOOL)
691 static u32 btf_type_int(const struct btf_type *t)
693 return *(u32 *)(t + 1);
696 static const struct btf_array *btf_type_array(const struct btf_type *t)
698 return (const struct btf_array *)(t + 1);
701 static const struct btf_enum *btf_type_enum(const struct btf_type *t)
703 return (const struct btf_enum *)(t + 1);
706 static const struct btf_var *btf_type_var(const struct btf_type *t)
708 return (const struct btf_var *)(t + 1);
711 static const struct btf_decl_tag *btf_type_decl_tag(const struct btf_type *t)
713 return (const struct btf_decl_tag *)(t + 1);
716 static const struct btf_enum64 *btf_type_enum64(const struct btf_type *t)
718 return (const struct btf_enum64 *)(t + 1);
721 static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t)
723 return kind_ops[BTF_INFO_KIND(t->info)];
726 static bool btf_name_offset_valid(const struct btf *btf, u32 offset)
728 if (!BTF_STR_OFFSET_VALID(offset))
731 while (offset < btf->start_str_off)
734 offset -= btf->start_str_off;
735 return offset < btf->hdr.str_len;
738 static bool __btf_name_char_ok(char c, bool first, bool dot_ok)
740 if ((first ? !isalpha(c) :
743 ((c == '.' && !dot_ok) ||
749 static const char *btf_str_by_offset(const struct btf *btf, u32 offset)
751 while (offset < btf->start_str_off)
754 offset -= btf->start_str_off;
755 if (offset < btf->hdr.str_len)
756 return &btf->strings[offset];
761 static bool __btf_name_valid(const struct btf *btf, u32 offset, bool dot_ok)
763 /* offset must be valid */
764 const char *src = btf_str_by_offset(btf, offset);
765 const char *src_limit;
767 if (!__btf_name_char_ok(*src, true, dot_ok))
770 /* set a limit on identifier length */
771 src_limit = src + KSYM_NAME_LEN;
773 while (*src && src < src_limit) {
774 if (!__btf_name_char_ok(*src, false, dot_ok))
782 /* Only C-style identifier is permitted. This can be relaxed if
785 static bool btf_name_valid_identifier(const struct btf *btf, u32 offset)
787 return __btf_name_valid(btf, offset, false);
790 static bool btf_name_valid_section(const struct btf *btf, u32 offset)
792 return __btf_name_valid(btf, offset, true);
795 static const char *__btf_name_by_offset(const struct btf *btf, u32 offset)
802 name = btf_str_by_offset(btf, offset);
803 return name ?: "(invalid-name-offset)";
806 const char *btf_name_by_offset(const struct btf *btf, u32 offset)
808 return btf_str_by_offset(btf, offset);
811 const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id)
813 while (type_id < btf->start_id)
816 type_id -= btf->start_id;
817 if (type_id >= btf->nr_types)
819 return btf->types[type_id];
823 * Regular int is not a bit field and it must be either
824 * u8/u16/u32/u64 or __int128.
826 static bool btf_type_int_is_regular(const struct btf_type *t)
828 u8 nr_bits, nr_bytes;
831 int_data = btf_type_int(t);
832 nr_bits = BTF_INT_BITS(int_data);
833 nr_bytes = BITS_ROUNDUP_BYTES(nr_bits);
834 if (BITS_PER_BYTE_MASKED(nr_bits) ||
835 BTF_INT_OFFSET(int_data) ||
836 (nr_bytes != sizeof(u8) && nr_bytes != sizeof(u16) &&
837 nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64) &&
838 nr_bytes != (2 * sizeof(u64)))) {
846 * Check that given struct member is a regular int with expected
849 bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
850 const struct btf_member *m,
851 u32 expected_offset, u32 expected_size)
853 const struct btf_type *t;
858 t = btf_type_id_size(btf, &id, NULL);
859 if (!t || !btf_type_is_int(t))
862 int_data = btf_type_int(t);
863 nr_bits = BTF_INT_BITS(int_data);
864 if (btf_type_kflag(s)) {
865 u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset);
866 u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset);
868 /* if kflag set, int should be a regular int and
869 * bit offset should be at byte boundary.
871 return !bitfield_size &&
872 BITS_ROUNDUP_BYTES(bit_offset) == expected_offset &&
873 BITS_ROUNDUP_BYTES(nr_bits) == expected_size;
876 if (BTF_INT_OFFSET(int_data) ||
877 BITS_PER_BYTE_MASKED(m->offset) ||
878 BITS_ROUNDUP_BYTES(m->offset) != expected_offset ||
879 BITS_PER_BYTE_MASKED(nr_bits) ||
880 BITS_ROUNDUP_BYTES(nr_bits) != expected_size)
886 /* Similar to btf_type_skip_modifiers() but does not skip typedefs. */
887 static const struct btf_type *btf_type_skip_qualifiers(const struct btf *btf,
890 const struct btf_type *t = btf_type_by_id(btf, id);
892 while (btf_type_is_modifier(t) &&
893 BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF) {
894 t = btf_type_by_id(btf, t->type);
900 #define BTF_SHOW_MAX_ITER 10
902 #define BTF_KIND_BIT(kind) (1ULL << kind)
905 * Populate show->state.name with type name information.
906 * Format of type name is
908 * [.member_name = ] (type_name)
910 static const char *btf_show_name(struct btf_show *show)
912 /* BTF_MAX_ITER array suffixes "[]" */
913 const char *array_suffixes = "[][][][][][][][][][]";
914 const char *array_suffix = &array_suffixes[strlen(array_suffixes)];
915 /* BTF_MAX_ITER pointer suffixes "*" */
916 const char *ptr_suffixes = "**********";
917 const char *ptr_suffix = &ptr_suffixes[strlen(ptr_suffixes)];
918 const char *name = NULL, *prefix = "", *parens = "";
919 const struct btf_member *m = show->state.member;
920 const struct btf_type *t;
921 const struct btf_array *array;
922 u32 id = show->state.type_id;
923 const char *member = NULL;
924 bool show_member = false;
928 show->state.name[0] = '\0';
931 * Don't show type name if we're showing an array member;
932 * in that case we show the array type so don't need to repeat
933 * ourselves for each member.
935 if (show->state.array_member)
938 /* Retrieve member name, if any. */
940 member = btf_name_by_offset(show->btf, m->name_off);
941 show_member = strlen(member) > 0;
946 * Start with type_id, as we have resolved the struct btf_type *
947 * via btf_modifier_show() past the parent typedef to the child
948 * struct, int etc it is defined as. In such cases, the type_id
949 * still represents the starting type while the struct btf_type *
950 * in our show->state points at the resolved type of the typedef.
952 t = btf_type_by_id(show->btf, id);
957 * The goal here is to build up the right number of pointer and
958 * array suffixes while ensuring the type name for a typedef
959 * is represented. Along the way we accumulate a list of
960 * BTF kinds we have encountered, since these will inform later
961 * display; for example, pointer types will not require an
962 * opening "{" for struct, we will just display the pointer value.
964 * We also want to accumulate the right number of pointer or array
965 * indices in the format string while iterating until we get to
966 * the typedef/pointee/array member target type.
968 * We start by pointing at the end of pointer and array suffix
969 * strings; as we accumulate pointers and arrays we move the pointer
970 * or array string backwards so it will show the expected number of
971 * '*' or '[]' for the type. BTF_SHOW_MAX_ITER of nesting of pointers
972 * and/or arrays and typedefs are supported as a precaution.
974 * We also want to get typedef name while proceeding to resolve
975 * type it points to so that we can add parentheses if it is a
976 * "typedef struct" etc.
978 for (i = 0; i < BTF_SHOW_MAX_ITER; i++) {
980 switch (BTF_INFO_KIND(t->info)) {
981 case BTF_KIND_TYPEDEF:
983 name = btf_name_by_offset(show->btf,
985 kinds |= BTF_KIND_BIT(BTF_KIND_TYPEDEF);
989 kinds |= BTF_KIND_BIT(BTF_KIND_ARRAY);
993 array = btf_type_array(t);
994 if (array_suffix > array_suffixes)
999 kinds |= BTF_KIND_BIT(BTF_KIND_PTR);
1000 if (ptr_suffix > ptr_suffixes)
1010 t = btf_type_skip_qualifiers(show->btf, id);
1012 /* We may not be able to represent this type; bail to be safe */
1013 if (i == BTF_SHOW_MAX_ITER)
1017 name = btf_name_by_offset(show->btf, t->name_off);
1019 switch (BTF_INFO_KIND(t->info)) {
1020 case BTF_KIND_STRUCT:
1021 case BTF_KIND_UNION:
1022 prefix = BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT ?
1024 /* if it's an array of struct/union, parens is already set */
1025 if (!(kinds & (BTF_KIND_BIT(BTF_KIND_ARRAY))))
1029 case BTF_KIND_ENUM64:
1036 /* pointer does not require parens */
1037 if (kinds & BTF_KIND_BIT(BTF_KIND_PTR))
1039 /* typedef does not require struct/union/enum prefix */
1040 if (kinds & BTF_KIND_BIT(BTF_KIND_TYPEDEF))
1046 /* Even if we don't want type name info, we want parentheses etc */
1047 if (show->flags & BTF_SHOW_NONAME)
1048 snprintf(show->state.name, sizeof(show->state.name), "%s",
1051 snprintf(show->state.name, sizeof(show->state.name),
1052 "%s%s%s(%s%s%s%s%s%s)%s",
1053 /* first 3 strings comprise ".member = " */
1054 show_member ? "." : "",
1055 show_member ? member : "",
1056 show_member ? " = " : "",
1057 /* ...next is our prefix (struct, enum, etc) */
1059 strlen(prefix) > 0 && strlen(name) > 0 ? " " : "",
1060 /* ...this is the type name itself */
1062 /* ...suffixed by the appropriate '*', '[]' suffixes */
1063 strlen(ptr_suffix) > 0 ? " " : "", ptr_suffix,
1064 array_suffix, parens);
1066 return show->state.name;
1069 static const char *__btf_show_indent(struct btf_show *show)
1071 const char *indents = " ";
1072 const char *indent = &indents[strlen(indents)];
1074 if ((indent - show->state.depth) >= indents)
1075 return indent - show->state.depth;
1079 static const char *btf_show_indent(struct btf_show *show)
1081 return show->flags & BTF_SHOW_COMPACT ? "" : __btf_show_indent(show);
1084 static const char *btf_show_newline(struct btf_show *show)
1086 return show->flags & BTF_SHOW_COMPACT ? "" : "\n";
1089 static const char *btf_show_delim(struct btf_show *show)
1091 if (show->state.depth == 0)
1094 if ((show->flags & BTF_SHOW_COMPACT) && show->state.type &&
1095 BTF_INFO_KIND(show->state.type->info) == BTF_KIND_UNION)
1101 __printf(2, 3) static void btf_show(struct btf_show *show, const char *fmt, ...)
1105 if (!show->state.depth_check) {
1106 va_start(args, fmt);
1107 show->showfn(show, fmt, args);
1112 /* Macros are used here as btf_show_type_value[s]() prepends and appends
1113 * format specifiers to the format specifier passed in; these do the work of
1114 * adding indentation, delimiters etc while the caller simply has to specify
1115 * the type value(s) in the format specifier + value(s).
1117 #define btf_show_type_value(show, fmt, value) \
1119 if ((value) != 0 || (show->flags & BTF_SHOW_ZERO) || \
1120 show->state.depth == 0) { \
1121 btf_show(show, "%s%s" fmt "%s%s", \
1122 btf_show_indent(show), \
1123 btf_show_name(show), \
1124 value, btf_show_delim(show), \
1125 btf_show_newline(show)); \
1126 if (show->state.depth > show->state.depth_to_show) \
1127 show->state.depth_to_show = show->state.depth; \
1131 #define btf_show_type_values(show, fmt, ...) \
1133 btf_show(show, "%s%s" fmt "%s%s", btf_show_indent(show), \
1134 btf_show_name(show), \
1135 __VA_ARGS__, btf_show_delim(show), \
1136 btf_show_newline(show)); \
1137 if (show->state.depth > show->state.depth_to_show) \
1138 show->state.depth_to_show = show->state.depth; \
1141 /* How much is left to copy to safe buffer after @data? */
1142 static int btf_show_obj_size_left(struct btf_show *show, void *data)
1144 return show->obj.head + show->obj.size - data;
1147 /* Is object pointed to by @data of @size already copied to our safe buffer? */
1148 static bool btf_show_obj_is_safe(struct btf_show *show, void *data, int size)
1150 return data >= show->obj.data &&
1151 (data + size) < (show->obj.data + BTF_SHOW_OBJ_SAFE_SIZE);
1155 * If object pointed to by @data of @size falls within our safe buffer, return
1156 * the equivalent pointer to the same safe data. Assumes
1157 * copy_from_kernel_nofault() has already happened and our safe buffer is
1160 static void *__btf_show_obj_safe(struct btf_show *show, void *data, int size)
1162 if (btf_show_obj_is_safe(show, data, size))
1163 return show->obj.safe + (data - show->obj.data);
1168 * Return a safe-to-access version of data pointed to by @data.
1169 * We do this by copying the relevant amount of information
1170 * to the struct btf_show obj.safe buffer using copy_from_kernel_nofault().
1172 * If BTF_SHOW_UNSAFE is specified, just return data as-is; no
1173 * safe copy is needed.
1175 * Otherwise we need to determine if we have the required amount
1176 * of data (determined by the @data pointer and the size of the
1177 * largest base type we can encounter (represented by
1178 * BTF_SHOW_OBJ_BASE_TYPE_SIZE). Having that much data ensures
1179 * that we will be able to print some of the current object,
1180 * and if more is needed a copy will be triggered.
1181 * Some objects such as structs will not fit into the buffer;
1182 * in such cases additional copies when we iterate over their
1183 * members may be needed.
1185 * btf_show_obj_safe() is used to return a safe buffer for
1186 * btf_show_start_type(); this ensures that as we recurse into
1187 * nested types we always have safe data for the given type.
1188 * This approach is somewhat wasteful; it's possible for example
1189 * that when iterating over a large union we'll end up copying the
1190 * same data repeatedly, but the goal is safety not performance.
1191 * We use stack data as opposed to per-CPU buffers because the
1192 * iteration over a type can take some time, and preemption handling
1193 * would greatly complicate use of the safe buffer.
1195 static void *btf_show_obj_safe(struct btf_show *show,
1196 const struct btf_type *t,
1199 const struct btf_type *rt;
1200 int size_left, size;
1203 if (show->flags & BTF_SHOW_UNSAFE)
1206 rt = btf_resolve_size(show->btf, t, &size);
1208 show->state.status = PTR_ERR(rt);
1213 * Is this toplevel object? If so, set total object size and
1214 * initialize pointers. Otherwise check if we still fall within
1215 * our safe object data.
1217 if (show->state.depth == 0) {
1218 show->obj.size = size;
1219 show->obj.head = data;
1222 * If the size of the current object is > our remaining
1223 * safe buffer we _may_ need to do a new copy. However
1224 * consider the case of a nested struct; it's size pushes
1225 * us over the safe buffer limit, but showing any individual
1226 * struct members does not. In such cases, we don't need
1227 * to initiate a fresh copy yet; however we definitely need
1228 * at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes left
1229 * in our buffer, regardless of the current object size.
1230 * The logic here is that as we resolve types we will
1231 * hit a base type at some point, and we need to be sure
1232 * the next chunk of data is safely available to display
1233 * that type info safely. We cannot rely on the size of
1234 * the current object here because it may be much larger
1235 * than our current buffer (e.g. task_struct is 8k).
1236 * All we want to do here is ensure that we can print the
1237 * next basic type, which we can if either
1238 * - the current type size is within the safe buffer; or
1239 * - at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes are left in
1242 safe = __btf_show_obj_safe(show, data,
1244 BTF_SHOW_OBJ_BASE_TYPE_SIZE));
1248 * We need a new copy to our safe object, either because we haven't
1249 * yet copied and are initializing safe data, or because the data
1250 * we want falls outside the boundaries of the safe object.
1253 size_left = btf_show_obj_size_left(show, data);
1254 if (size_left > BTF_SHOW_OBJ_SAFE_SIZE)
1255 size_left = BTF_SHOW_OBJ_SAFE_SIZE;
1256 show->state.status = copy_from_kernel_nofault(show->obj.safe,
1258 if (!show->state.status) {
1259 show->obj.data = data;
1260 safe = show->obj.safe;
1268 * Set the type we are starting to show and return a safe data pointer
1269 * to be used for showing the associated data.
1271 static void *btf_show_start_type(struct btf_show *show,
1272 const struct btf_type *t,
1273 u32 type_id, void *data)
1275 show->state.type = t;
1276 show->state.type_id = type_id;
1277 show->state.name[0] = '\0';
1279 return btf_show_obj_safe(show, t, data);
1282 static void btf_show_end_type(struct btf_show *show)
1284 show->state.type = NULL;
1285 show->state.type_id = 0;
1286 show->state.name[0] = '\0';
1289 static void *btf_show_start_aggr_type(struct btf_show *show,
1290 const struct btf_type *t,
1291 u32 type_id, void *data)
1293 void *safe_data = btf_show_start_type(show, t, type_id, data);
1298 btf_show(show, "%s%s%s", btf_show_indent(show),
1299 btf_show_name(show),
1300 btf_show_newline(show));
1301 show->state.depth++;
1305 static void btf_show_end_aggr_type(struct btf_show *show,
1308 show->state.depth--;
1309 btf_show(show, "%s%s%s%s", btf_show_indent(show), suffix,
1310 btf_show_delim(show), btf_show_newline(show));
1311 btf_show_end_type(show);
1314 static void btf_show_start_member(struct btf_show *show,
1315 const struct btf_member *m)
1317 show->state.member = m;
1320 static void btf_show_start_array_member(struct btf_show *show)
1322 show->state.array_member = 1;
1323 btf_show_start_member(show, NULL);
1326 static void btf_show_end_member(struct btf_show *show)
1328 show->state.member = NULL;
1331 static void btf_show_end_array_member(struct btf_show *show)
1333 show->state.array_member = 0;
1334 btf_show_end_member(show);
1337 static void *btf_show_start_array_type(struct btf_show *show,
1338 const struct btf_type *t,
1343 show->state.array_encoding = array_encoding;
1344 show->state.array_terminated = 0;
1345 return btf_show_start_aggr_type(show, t, type_id, data);
1348 static void btf_show_end_array_type(struct btf_show *show)
1350 show->state.array_encoding = 0;
1351 show->state.array_terminated = 0;
1352 btf_show_end_aggr_type(show, "]");
1355 static void *btf_show_start_struct_type(struct btf_show *show,
1356 const struct btf_type *t,
1360 return btf_show_start_aggr_type(show, t, type_id, data);
1363 static void btf_show_end_struct_type(struct btf_show *show)
1365 btf_show_end_aggr_type(show, "}");
1368 __printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log,
1369 const char *fmt, ...)
1373 va_start(args, fmt);
1374 bpf_verifier_vlog(log, fmt, args);
1378 __printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env,
1379 const char *fmt, ...)
1381 struct bpf_verifier_log *log = &env->log;
1384 if (!bpf_verifier_log_needed(log))
1387 va_start(args, fmt);
1388 bpf_verifier_vlog(log, fmt, args);
1392 __printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env,
1393 const struct btf_type *t,
1395 const char *fmt, ...)
1397 struct bpf_verifier_log *log = &env->log;
1398 u8 kind = BTF_INFO_KIND(t->info);
1399 struct btf *btf = env->btf;
1402 if (!bpf_verifier_log_needed(log))
1405 /* btf verifier prints all types it is processing via
1406 * btf_verifier_log_type(..., fmt = NULL).
1407 * Skip those prints for in-kernel BTF verification.
1409 if (log->level == BPF_LOG_KERNEL && !fmt)
1412 __btf_verifier_log(log, "[%u] %s %s%s",
1415 __btf_name_by_offset(btf, t->name_off),
1416 log_details ? " " : "");
1419 btf_type_ops(t)->log_details(env, t);
1422 __btf_verifier_log(log, " ");
1423 va_start(args, fmt);
1424 bpf_verifier_vlog(log, fmt, args);
1428 __btf_verifier_log(log, "\n");
1431 #define btf_verifier_log_type(env, t, ...) \
1432 __btf_verifier_log_type((env), (t), true, __VA_ARGS__)
1433 #define btf_verifier_log_basic(env, t, ...) \
1434 __btf_verifier_log_type((env), (t), false, __VA_ARGS__)
1437 static void btf_verifier_log_member(struct btf_verifier_env *env,
1438 const struct btf_type *struct_type,
1439 const struct btf_member *member,
1440 const char *fmt, ...)
1442 struct bpf_verifier_log *log = &env->log;
1443 struct btf *btf = env->btf;
1446 if (!bpf_verifier_log_needed(log))
1449 if (log->level == BPF_LOG_KERNEL && !fmt)
1451 /* The CHECK_META phase already did a btf dump.
1453 * If member is logged again, it must hit an error in
1454 * parsing this member. It is useful to print out which
1455 * struct this member belongs to.
1457 if (env->phase != CHECK_META)
1458 btf_verifier_log_type(env, struct_type, NULL);
1460 if (btf_type_kflag(struct_type))
1461 __btf_verifier_log(log,
1462 "\t%s type_id=%u bitfield_size=%u bits_offset=%u",
1463 __btf_name_by_offset(btf, member->name_off),
1465 BTF_MEMBER_BITFIELD_SIZE(member->offset),
1466 BTF_MEMBER_BIT_OFFSET(member->offset));
1468 __btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u",
1469 __btf_name_by_offset(btf, member->name_off),
1470 member->type, member->offset);
1473 __btf_verifier_log(log, " ");
1474 va_start(args, fmt);
1475 bpf_verifier_vlog(log, fmt, args);
1479 __btf_verifier_log(log, "\n");
1483 static void btf_verifier_log_vsi(struct btf_verifier_env *env,
1484 const struct btf_type *datasec_type,
1485 const struct btf_var_secinfo *vsi,
1486 const char *fmt, ...)
1488 struct bpf_verifier_log *log = &env->log;
1491 if (!bpf_verifier_log_needed(log))
1493 if (log->level == BPF_LOG_KERNEL && !fmt)
1495 if (env->phase != CHECK_META)
1496 btf_verifier_log_type(env, datasec_type, NULL);
1498 __btf_verifier_log(log, "\t type_id=%u offset=%u size=%u",
1499 vsi->type, vsi->offset, vsi->size);
1501 __btf_verifier_log(log, " ");
1502 va_start(args, fmt);
1503 bpf_verifier_vlog(log, fmt, args);
1507 __btf_verifier_log(log, "\n");
1510 static void btf_verifier_log_hdr(struct btf_verifier_env *env,
1513 struct bpf_verifier_log *log = &env->log;
1514 const struct btf *btf = env->btf;
1515 const struct btf_header *hdr;
1517 if (!bpf_verifier_log_needed(log))
1520 if (log->level == BPF_LOG_KERNEL)
1523 __btf_verifier_log(log, "magic: 0x%x\n", hdr->magic);
1524 __btf_verifier_log(log, "version: %u\n", hdr->version);
1525 __btf_verifier_log(log, "flags: 0x%x\n", hdr->flags);
1526 __btf_verifier_log(log, "hdr_len: %u\n", hdr->hdr_len);
1527 __btf_verifier_log(log, "type_off: %u\n", hdr->type_off);
1528 __btf_verifier_log(log, "type_len: %u\n", hdr->type_len);
1529 __btf_verifier_log(log, "str_off: %u\n", hdr->str_off);
1530 __btf_verifier_log(log, "str_len: %u\n", hdr->str_len);
1531 __btf_verifier_log(log, "btf_total_size: %u\n", btf_data_size);
1534 static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t)
1536 struct btf *btf = env->btf;
1538 if (btf->types_size == btf->nr_types) {
1539 /* Expand 'types' array */
1541 struct btf_type **new_types;
1542 u32 expand_by, new_size;
1544 if (btf->start_id + btf->types_size == BTF_MAX_TYPE) {
1545 btf_verifier_log(env, "Exceeded max num of types");
1549 expand_by = max_t(u32, btf->types_size >> 2, 16);
1550 new_size = min_t(u32, BTF_MAX_TYPE,
1551 btf->types_size + expand_by);
1553 new_types = kvcalloc(new_size, sizeof(*new_types),
1554 GFP_KERNEL | __GFP_NOWARN);
1558 if (btf->nr_types == 0) {
1559 if (!btf->base_btf) {
1560 /* lazily init VOID type */
1561 new_types[0] = &btf_void;
1565 memcpy(new_types, btf->types,
1566 sizeof(*btf->types) * btf->nr_types);
1570 btf->types = new_types;
1571 btf->types_size = new_size;
1574 btf->types[btf->nr_types++] = t;
1579 static int btf_alloc_id(struct btf *btf)
1583 idr_preload(GFP_KERNEL);
1584 spin_lock_bh(&btf_idr_lock);
1585 id = idr_alloc_cyclic(&btf_idr, btf, 1, INT_MAX, GFP_ATOMIC);
1588 spin_unlock_bh(&btf_idr_lock);
1591 if (WARN_ON_ONCE(!id))
1594 return id > 0 ? 0 : id;
1597 static void btf_free_id(struct btf *btf)
1599 unsigned long flags;
1602 * In map-in-map, calling map_delete_elem() on outer
1603 * map will call bpf_map_put on the inner map.
1604 * It will then eventually call btf_free_id()
1605 * on the inner map. Some of the map_delete_elem()
1606 * implementation may have irq disabled, so
1607 * we need to use the _irqsave() version instead
1608 * of the _bh() version.
1610 spin_lock_irqsave(&btf_idr_lock, flags);
1611 idr_remove(&btf_idr, btf->id);
1612 spin_unlock_irqrestore(&btf_idr_lock, flags);
1615 static void btf_free_kfunc_set_tab(struct btf *btf)
1617 struct btf_kfunc_set_tab *tab = btf->kfunc_set_tab;
1622 /* For module BTF, we directly assign the sets being registered, so
1623 * there is nothing to free except kfunc_set_tab.
1625 if (btf_is_module(btf))
1627 for (hook = 0; hook < ARRAY_SIZE(tab->sets); hook++) {
1628 for (type = 0; type < ARRAY_SIZE(tab->sets[0]); type++)
1629 kfree(tab->sets[hook][type]);
1633 btf->kfunc_set_tab = NULL;
1636 static void btf_free_dtor_kfunc_tab(struct btf *btf)
1638 struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab;
1643 btf->dtor_kfunc_tab = NULL;
1646 static void btf_free(struct btf *btf)
1648 btf_free_dtor_kfunc_tab(btf);
1649 btf_free_kfunc_set_tab(btf);
1651 kvfree(btf->resolved_sizes);
1652 kvfree(btf->resolved_ids);
1657 static void btf_free_rcu(struct rcu_head *rcu)
1659 struct btf *btf = container_of(rcu, struct btf, rcu);
1664 void btf_get(struct btf *btf)
1666 refcount_inc(&btf->refcnt);
1669 void btf_put(struct btf *btf)
1671 if (btf && refcount_dec_and_test(&btf->refcnt)) {
1673 call_rcu(&btf->rcu, btf_free_rcu);
1677 static int env_resolve_init(struct btf_verifier_env *env)
1679 struct btf *btf = env->btf;
1680 u32 nr_types = btf->nr_types;
1681 u32 *resolved_sizes = NULL;
1682 u32 *resolved_ids = NULL;
1683 u8 *visit_states = NULL;
1685 resolved_sizes = kvcalloc(nr_types, sizeof(*resolved_sizes),
1686 GFP_KERNEL | __GFP_NOWARN);
1687 if (!resolved_sizes)
1690 resolved_ids = kvcalloc(nr_types, sizeof(*resolved_ids),
1691 GFP_KERNEL | __GFP_NOWARN);
1695 visit_states = kvcalloc(nr_types, sizeof(*visit_states),
1696 GFP_KERNEL | __GFP_NOWARN);
1700 btf->resolved_sizes = resolved_sizes;
1701 btf->resolved_ids = resolved_ids;
1702 env->visit_states = visit_states;
1707 kvfree(resolved_sizes);
1708 kvfree(resolved_ids);
1709 kvfree(visit_states);
1713 static void btf_verifier_env_free(struct btf_verifier_env *env)
1715 kvfree(env->visit_states);
1719 static bool env_type_is_resolve_sink(const struct btf_verifier_env *env,
1720 const struct btf_type *next_type)
1722 switch (env->resolve_mode) {
1724 /* int, enum or void is a sink */
1725 return !btf_type_needs_resolve(next_type);
1727 /* int, enum, void, struct, array, func or func_proto is a sink
1730 return !btf_type_is_modifier(next_type) &&
1731 !btf_type_is_ptr(next_type);
1732 case RESOLVE_STRUCT_OR_ARRAY:
1733 /* int, enum, void, ptr, func or func_proto is a sink
1734 * for struct and array
1736 return !btf_type_is_modifier(next_type) &&
1737 !btf_type_is_array(next_type) &&
1738 !btf_type_is_struct(next_type);
1744 static bool env_type_is_resolved(const struct btf_verifier_env *env,
1747 /* base BTF types should be resolved by now */
1748 if (type_id < env->btf->start_id)
1751 return env->visit_states[type_id - env->btf->start_id] == RESOLVED;
1754 static int env_stack_push(struct btf_verifier_env *env,
1755 const struct btf_type *t, u32 type_id)
1757 const struct btf *btf = env->btf;
1758 struct resolve_vertex *v;
1760 if (env->top_stack == MAX_RESOLVE_DEPTH)
1763 if (type_id < btf->start_id
1764 || env->visit_states[type_id - btf->start_id] != NOT_VISITED)
1767 env->visit_states[type_id - btf->start_id] = VISITED;
1769 v = &env->stack[env->top_stack++];
1771 v->type_id = type_id;
1774 if (env->resolve_mode == RESOLVE_TBD) {
1775 if (btf_type_is_ptr(t))
1776 env->resolve_mode = RESOLVE_PTR;
1777 else if (btf_type_is_struct(t) || btf_type_is_array(t))
1778 env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY;
1784 static void env_stack_set_next_member(struct btf_verifier_env *env,
1787 env->stack[env->top_stack - 1].next_member = next_member;
1790 static void env_stack_pop_resolved(struct btf_verifier_env *env,
1791 u32 resolved_type_id,
1794 u32 type_id = env->stack[--(env->top_stack)].type_id;
1795 struct btf *btf = env->btf;
1797 type_id -= btf->start_id; /* adjust to local type id */
1798 btf->resolved_sizes[type_id] = resolved_size;
1799 btf->resolved_ids[type_id] = resolved_type_id;
1800 env->visit_states[type_id] = RESOLVED;
1803 static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env)
1805 return env->top_stack ? &env->stack[env->top_stack - 1] : NULL;
1808 /* Resolve the size of a passed-in "type"
1810 * type: is an array (e.g. u32 array[x][y])
1811 * return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY,
1812 * *type_size: (x * y * sizeof(u32)). Hence, *type_size always
1813 * corresponds to the return type.
1815 * *elem_id: id of u32
1816 * *total_nelems: (x * y). Hence, individual elem size is
1817 * (*type_size / *total_nelems)
1818 * *type_id: id of type if it's changed within the function, 0 if not
1820 * type: is not an array (e.g. const struct X)
1821 * return type: type "struct X"
1822 * *type_size: sizeof(struct X)
1823 * *elem_type: same as return type ("struct X")
1826 * *type_id: id of type if it's changed within the function, 0 if not
1828 static const struct btf_type *
1829 __btf_resolve_size(const struct btf *btf, const struct btf_type *type,
1830 u32 *type_size, const struct btf_type **elem_type,
1831 u32 *elem_id, u32 *total_nelems, u32 *type_id)
1833 const struct btf_type *array_type = NULL;
1834 const struct btf_array *array = NULL;
1835 u32 i, size, nelems = 1, id = 0;
1837 for (i = 0; i < MAX_RESOLVE_DEPTH; i++) {
1838 switch (BTF_INFO_KIND(type->info)) {
1839 /* type->size can be used */
1841 case BTF_KIND_STRUCT:
1842 case BTF_KIND_UNION:
1844 case BTF_KIND_FLOAT:
1845 case BTF_KIND_ENUM64:
1850 size = sizeof(void *);
1854 case BTF_KIND_TYPEDEF:
1855 case BTF_KIND_VOLATILE:
1856 case BTF_KIND_CONST:
1857 case BTF_KIND_RESTRICT:
1858 case BTF_KIND_TYPE_TAG:
1860 type = btf_type_by_id(btf, type->type);
1863 case BTF_KIND_ARRAY:
1866 array = btf_type_array(type);
1867 if (nelems && array->nelems > U32_MAX / nelems)
1868 return ERR_PTR(-EINVAL);
1869 nelems *= array->nelems;
1870 type = btf_type_by_id(btf, array->type);
1873 /* type without size */
1875 return ERR_PTR(-EINVAL);
1879 return ERR_PTR(-EINVAL);
1882 if (nelems && size > U32_MAX / nelems)
1883 return ERR_PTR(-EINVAL);
1885 *type_size = nelems * size;
1887 *total_nelems = nelems;
1891 *elem_id = array ? array->type : 0;
1895 return array_type ? : type;
1898 const struct btf_type *
1899 btf_resolve_size(const struct btf *btf, const struct btf_type *type,
1902 return __btf_resolve_size(btf, type, type_size, NULL, NULL, NULL, NULL);
1905 static u32 btf_resolved_type_id(const struct btf *btf, u32 type_id)
1907 while (type_id < btf->start_id)
1908 btf = btf->base_btf;
1910 return btf->resolved_ids[type_id - btf->start_id];
1913 /* The input param "type_id" must point to a needs_resolve type */
1914 static const struct btf_type *btf_type_id_resolve(const struct btf *btf,
1917 *type_id = btf_resolved_type_id(btf, *type_id);
1918 return btf_type_by_id(btf, *type_id);
1921 static u32 btf_resolved_type_size(const struct btf *btf, u32 type_id)
1923 while (type_id < btf->start_id)
1924 btf = btf->base_btf;
1926 return btf->resolved_sizes[type_id - btf->start_id];
1929 const struct btf_type *btf_type_id_size(const struct btf *btf,
1930 u32 *type_id, u32 *ret_size)
1932 const struct btf_type *size_type;
1933 u32 size_type_id = *type_id;
1936 size_type = btf_type_by_id(btf, size_type_id);
1937 if (btf_type_nosize_or_null(size_type))
1940 if (btf_type_has_size(size_type)) {
1941 size = size_type->size;
1942 } else if (btf_type_is_array(size_type)) {
1943 size = btf_resolved_type_size(btf, size_type_id);
1944 } else if (btf_type_is_ptr(size_type)) {
1945 size = sizeof(void *);
1947 if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) &&
1948 !btf_type_is_var(size_type)))
1951 size_type_id = btf_resolved_type_id(btf, size_type_id);
1952 size_type = btf_type_by_id(btf, size_type_id);
1953 if (btf_type_nosize_or_null(size_type))
1955 else if (btf_type_has_size(size_type))
1956 size = size_type->size;
1957 else if (btf_type_is_array(size_type))
1958 size = btf_resolved_type_size(btf, size_type_id);
1959 else if (btf_type_is_ptr(size_type))
1960 size = sizeof(void *);
1965 *type_id = size_type_id;
1972 static int btf_df_check_member(struct btf_verifier_env *env,
1973 const struct btf_type *struct_type,
1974 const struct btf_member *member,
1975 const struct btf_type *member_type)
1977 btf_verifier_log_basic(env, struct_type,
1978 "Unsupported check_member");
1982 static int btf_df_check_kflag_member(struct btf_verifier_env *env,
1983 const struct btf_type *struct_type,
1984 const struct btf_member *member,
1985 const struct btf_type *member_type)
1987 btf_verifier_log_basic(env, struct_type,
1988 "Unsupported check_kflag_member");
1992 /* Used for ptr, array struct/union and float type members.
1993 * int, enum and modifier types have their specific callback functions.
1995 static int btf_generic_check_kflag_member(struct btf_verifier_env *env,
1996 const struct btf_type *struct_type,
1997 const struct btf_member *member,
1998 const struct btf_type *member_type)
2000 if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) {
2001 btf_verifier_log_member(env, struct_type, member,
2002 "Invalid member bitfield_size");
2006 /* bitfield size is 0, so member->offset represents bit offset only.
2007 * It is safe to call non kflag check_member variants.
2009 return btf_type_ops(member_type)->check_member(env, struct_type,
2014 static int btf_df_resolve(struct btf_verifier_env *env,
2015 const struct resolve_vertex *v)
2017 btf_verifier_log_basic(env, v->t, "Unsupported resolve");
2021 static void btf_df_show(const struct btf *btf, const struct btf_type *t,
2022 u32 type_id, void *data, u8 bits_offsets,
2023 struct btf_show *show)
2025 btf_show(show, "<unsupported kind:%u>", BTF_INFO_KIND(t->info));
2028 static int btf_int_check_member(struct btf_verifier_env *env,
2029 const struct btf_type *struct_type,
2030 const struct btf_member *member,
2031 const struct btf_type *member_type)
2033 u32 int_data = btf_type_int(member_type);
2034 u32 struct_bits_off = member->offset;
2035 u32 struct_size = struct_type->size;
2039 if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) {
2040 btf_verifier_log_member(env, struct_type, member,
2041 "bits_offset exceeds U32_MAX");
2045 struct_bits_off += BTF_INT_OFFSET(int_data);
2046 bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
2047 nr_copy_bits = BTF_INT_BITS(int_data) +
2048 BITS_PER_BYTE_MASKED(struct_bits_off);
2050 if (nr_copy_bits > BITS_PER_U128) {
2051 btf_verifier_log_member(env, struct_type, member,
2052 "nr_copy_bits exceeds 128");
2056 if (struct_size < bytes_offset ||
2057 struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) {
2058 btf_verifier_log_member(env, struct_type, member,
2059 "Member exceeds struct_size");
2066 static int btf_int_check_kflag_member(struct btf_verifier_env *env,
2067 const struct btf_type *struct_type,
2068 const struct btf_member *member,
2069 const struct btf_type *member_type)
2071 u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset;
2072 u32 int_data = btf_type_int(member_type);
2073 u32 struct_size = struct_type->size;
2076 /* a regular int type is required for the kflag int member */
2077 if (!btf_type_int_is_regular(member_type)) {
2078 btf_verifier_log_member(env, struct_type, member,
2079 "Invalid member base type");
2083 /* check sanity of bitfield size */
2084 nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset);
2085 struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset);
2086 nr_int_data_bits = BTF_INT_BITS(int_data);
2088 /* Not a bitfield member, member offset must be at byte
2091 if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
2092 btf_verifier_log_member(env, struct_type, member,
2093 "Invalid member offset");
2097 nr_bits = nr_int_data_bits;
2098 } else if (nr_bits > nr_int_data_bits) {
2099 btf_verifier_log_member(env, struct_type, member,
2100 "Invalid member bitfield_size");
2104 bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
2105 nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off);
2106 if (nr_copy_bits > BITS_PER_U128) {
2107 btf_verifier_log_member(env, struct_type, member,
2108 "nr_copy_bits exceeds 128");
2112 if (struct_size < bytes_offset ||
2113 struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) {
2114 btf_verifier_log_member(env, struct_type, member,
2115 "Member exceeds struct_size");
2122 static s32 btf_int_check_meta(struct btf_verifier_env *env,
2123 const struct btf_type *t,
2126 u32 int_data, nr_bits, meta_needed = sizeof(int_data);
2129 if (meta_left < meta_needed) {
2130 btf_verifier_log_basic(env, t,
2131 "meta_left:%u meta_needed:%u",
2132 meta_left, meta_needed);
2136 if (btf_type_vlen(t)) {
2137 btf_verifier_log_type(env, t, "vlen != 0");
2141 if (btf_type_kflag(t)) {
2142 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
2146 int_data = btf_type_int(t);
2147 if (int_data & ~BTF_INT_MASK) {
2148 btf_verifier_log_basic(env, t, "Invalid int_data:%x",
2153 nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data);
2155 if (nr_bits > BITS_PER_U128) {
2156 btf_verifier_log_type(env, t, "nr_bits exceeds %zu",
2161 if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) {
2162 btf_verifier_log_type(env, t, "nr_bits exceeds type_size");
2167 * Only one of the encoding bits is allowed and it
2168 * should be sufficient for the pretty print purpose (i.e. decoding).
2169 * Multiple bits can be allowed later if it is found
2170 * to be insufficient.
2172 encoding = BTF_INT_ENCODING(int_data);
2174 encoding != BTF_INT_SIGNED &&
2175 encoding != BTF_INT_CHAR &&
2176 encoding != BTF_INT_BOOL) {
2177 btf_verifier_log_type(env, t, "Unsupported encoding");
2181 btf_verifier_log_type(env, t, NULL);
2186 static void btf_int_log(struct btf_verifier_env *env,
2187 const struct btf_type *t)
2189 int int_data = btf_type_int(t);
2191 btf_verifier_log(env,
2192 "size=%u bits_offset=%u nr_bits=%u encoding=%s",
2193 t->size, BTF_INT_OFFSET(int_data),
2194 BTF_INT_BITS(int_data),
2195 btf_int_encoding_str(BTF_INT_ENCODING(int_data)));
2198 static void btf_int128_print(struct btf_show *show, void *data)
2200 /* data points to a __int128 number.
2202 * int128_num = *(__int128 *)data;
2203 * The below formulas shows what upper_num and lower_num represents:
2204 * upper_num = int128_num >> 64;
2205 * lower_num = int128_num & 0xffffffffFFFFFFFFULL;
2207 u64 upper_num, lower_num;
2209 #ifdef __BIG_ENDIAN_BITFIELD
2210 upper_num = *(u64 *)data;
2211 lower_num = *(u64 *)(data + 8);
2213 upper_num = *(u64 *)(data + 8);
2214 lower_num = *(u64 *)data;
2217 btf_show_type_value(show, "0x%llx", lower_num);
2219 btf_show_type_values(show, "0x%llx%016llx", upper_num,
2223 static void btf_int128_shift(u64 *print_num, u16 left_shift_bits,
2224 u16 right_shift_bits)
2226 u64 upper_num, lower_num;
2228 #ifdef __BIG_ENDIAN_BITFIELD
2229 upper_num = print_num[0];
2230 lower_num = print_num[1];
2232 upper_num = print_num[1];
2233 lower_num = print_num[0];
2236 /* shake out un-needed bits by shift/or operations */
2237 if (left_shift_bits >= 64) {
2238 upper_num = lower_num << (left_shift_bits - 64);
2241 upper_num = (upper_num << left_shift_bits) |
2242 (lower_num >> (64 - left_shift_bits));
2243 lower_num = lower_num << left_shift_bits;
2246 if (right_shift_bits >= 64) {
2247 lower_num = upper_num >> (right_shift_bits - 64);
2250 lower_num = (lower_num >> right_shift_bits) |
2251 (upper_num << (64 - right_shift_bits));
2252 upper_num = upper_num >> right_shift_bits;
2255 #ifdef __BIG_ENDIAN_BITFIELD
2256 print_num[0] = upper_num;
2257 print_num[1] = lower_num;
2259 print_num[0] = lower_num;
2260 print_num[1] = upper_num;
2264 static void btf_bitfield_show(void *data, u8 bits_offset,
2265 u8 nr_bits, struct btf_show *show)
2267 u16 left_shift_bits, right_shift_bits;
2270 u64 print_num[2] = {};
2272 nr_copy_bits = nr_bits + bits_offset;
2273 nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits);
2275 memcpy(print_num, data, nr_copy_bytes);
2277 #ifdef __BIG_ENDIAN_BITFIELD
2278 left_shift_bits = bits_offset;
2280 left_shift_bits = BITS_PER_U128 - nr_copy_bits;
2282 right_shift_bits = BITS_PER_U128 - nr_bits;
2284 btf_int128_shift(print_num, left_shift_bits, right_shift_bits);
2285 btf_int128_print(show, print_num);
2289 static void btf_int_bits_show(const struct btf *btf,
2290 const struct btf_type *t,
2291 void *data, u8 bits_offset,
2292 struct btf_show *show)
2294 u32 int_data = btf_type_int(t);
2295 u8 nr_bits = BTF_INT_BITS(int_data);
2296 u8 total_bits_offset;
2299 * bits_offset is at most 7.
2300 * BTF_INT_OFFSET() cannot exceed 128 bits.
2302 total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data);
2303 data += BITS_ROUNDDOWN_BYTES(total_bits_offset);
2304 bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset);
2305 btf_bitfield_show(data, bits_offset, nr_bits, show);
2308 static void btf_int_show(const struct btf *btf, const struct btf_type *t,
2309 u32 type_id, void *data, u8 bits_offset,
2310 struct btf_show *show)
2312 u32 int_data = btf_type_int(t);
2313 u8 encoding = BTF_INT_ENCODING(int_data);
2314 bool sign = encoding & BTF_INT_SIGNED;
2315 u8 nr_bits = BTF_INT_BITS(int_data);
2318 safe_data = btf_show_start_type(show, t, type_id, data);
2322 if (bits_offset || BTF_INT_OFFSET(int_data) ||
2323 BITS_PER_BYTE_MASKED(nr_bits)) {
2324 btf_int_bits_show(btf, t, safe_data, bits_offset, show);
2330 btf_int128_print(show, safe_data);
2334 btf_show_type_value(show, "%lld", *(s64 *)safe_data);
2336 btf_show_type_value(show, "%llu", *(u64 *)safe_data);
2340 btf_show_type_value(show, "%d", *(s32 *)safe_data);
2342 btf_show_type_value(show, "%u", *(u32 *)safe_data);
2346 btf_show_type_value(show, "%d", *(s16 *)safe_data);
2348 btf_show_type_value(show, "%u", *(u16 *)safe_data);
2351 if (show->state.array_encoding == BTF_INT_CHAR) {
2352 /* check for null terminator */
2353 if (show->state.array_terminated)
2355 if (*(char *)data == '\0') {
2356 show->state.array_terminated = 1;
2359 if (isprint(*(char *)data)) {
2360 btf_show_type_value(show, "'%c'",
2361 *(char *)safe_data);
2366 btf_show_type_value(show, "%d", *(s8 *)safe_data);
2368 btf_show_type_value(show, "%u", *(u8 *)safe_data);
2371 btf_int_bits_show(btf, t, safe_data, bits_offset, show);
2375 btf_show_end_type(show);
2378 static const struct btf_kind_operations int_ops = {
2379 .check_meta = btf_int_check_meta,
2380 .resolve = btf_df_resolve,
2381 .check_member = btf_int_check_member,
2382 .check_kflag_member = btf_int_check_kflag_member,
2383 .log_details = btf_int_log,
2384 .show = btf_int_show,
2387 static int btf_modifier_check_member(struct btf_verifier_env *env,
2388 const struct btf_type *struct_type,
2389 const struct btf_member *member,
2390 const struct btf_type *member_type)
2392 const struct btf_type *resolved_type;
2393 u32 resolved_type_id = member->type;
2394 struct btf_member resolved_member;
2395 struct btf *btf = env->btf;
2397 resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL);
2398 if (!resolved_type) {
2399 btf_verifier_log_member(env, struct_type, member,
2404 resolved_member = *member;
2405 resolved_member.type = resolved_type_id;
2407 return btf_type_ops(resolved_type)->check_member(env, struct_type,
2412 static int btf_modifier_check_kflag_member(struct btf_verifier_env *env,
2413 const struct btf_type *struct_type,
2414 const struct btf_member *member,
2415 const struct btf_type *member_type)
2417 const struct btf_type *resolved_type;
2418 u32 resolved_type_id = member->type;
2419 struct btf_member resolved_member;
2420 struct btf *btf = env->btf;
2422 resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL);
2423 if (!resolved_type) {
2424 btf_verifier_log_member(env, struct_type, member,
2429 resolved_member = *member;
2430 resolved_member.type = resolved_type_id;
2432 return btf_type_ops(resolved_type)->check_kflag_member(env, struct_type,
2437 static int btf_ptr_check_member(struct btf_verifier_env *env,
2438 const struct btf_type *struct_type,
2439 const struct btf_member *member,
2440 const struct btf_type *member_type)
2442 u32 struct_size, struct_bits_off, bytes_offset;
2444 struct_size = struct_type->size;
2445 struct_bits_off = member->offset;
2446 bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
2448 if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
2449 btf_verifier_log_member(env, struct_type, member,
2450 "Member is not byte aligned");
2454 if (struct_size - bytes_offset < sizeof(void *)) {
2455 btf_verifier_log_member(env, struct_type, member,
2456 "Member exceeds struct_size");
2463 static int btf_ref_type_check_meta(struct btf_verifier_env *env,
2464 const struct btf_type *t,
2469 if (btf_type_vlen(t)) {
2470 btf_verifier_log_type(env, t, "vlen != 0");
2474 if (btf_type_kflag(t)) {
2475 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
2479 if (!BTF_TYPE_ID_VALID(t->type)) {
2480 btf_verifier_log_type(env, t, "Invalid type_id");
2484 /* typedef/type_tag type must have a valid name, and other ref types,
2485 * volatile, const, restrict, should have a null name.
2487 if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) {
2489 !btf_name_valid_identifier(env->btf, t->name_off)) {
2490 btf_verifier_log_type(env, t, "Invalid name");
2493 } else if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPE_TAG) {
2494 value = btf_name_by_offset(env->btf, t->name_off);
2495 if (!value || !value[0]) {
2496 btf_verifier_log_type(env, t, "Invalid name");
2501 btf_verifier_log_type(env, t, "Invalid name");
2506 btf_verifier_log_type(env, t, NULL);
2511 static int btf_modifier_resolve(struct btf_verifier_env *env,
2512 const struct resolve_vertex *v)
2514 const struct btf_type *t = v->t;
2515 const struct btf_type *next_type;
2516 u32 next_type_id = t->type;
2517 struct btf *btf = env->btf;
2519 next_type = btf_type_by_id(btf, next_type_id);
2520 if (!next_type || btf_type_is_resolve_source_only(next_type)) {
2521 btf_verifier_log_type(env, v->t, "Invalid type_id");
2525 if (!env_type_is_resolve_sink(env, next_type) &&
2526 !env_type_is_resolved(env, next_type_id))
2527 return env_stack_push(env, next_type, next_type_id);
2529 /* Figure out the resolved next_type_id with size.
2530 * They will be stored in the current modifier's
2531 * resolved_ids and resolved_sizes such that it can
2532 * save us a few type-following when we use it later (e.g. in
2535 if (!btf_type_id_size(btf, &next_type_id, NULL)) {
2536 if (env_type_is_resolved(env, next_type_id))
2537 next_type = btf_type_id_resolve(btf, &next_type_id);
2539 /* "typedef void new_void", "const void"...etc */
2540 if (!btf_type_is_void(next_type) &&
2541 !btf_type_is_fwd(next_type) &&
2542 !btf_type_is_func_proto(next_type)) {
2543 btf_verifier_log_type(env, v->t, "Invalid type_id");
2548 env_stack_pop_resolved(env, next_type_id, 0);
2553 static int btf_var_resolve(struct btf_verifier_env *env,
2554 const struct resolve_vertex *v)
2556 const struct btf_type *next_type;
2557 const struct btf_type *t = v->t;
2558 u32 next_type_id = t->type;
2559 struct btf *btf = env->btf;
2561 next_type = btf_type_by_id(btf, next_type_id);
2562 if (!next_type || btf_type_is_resolve_source_only(next_type)) {
2563 btf_verifier_log_type(env, v->t, "Invalid type_id");
2567 if (!env_type_is_resolve_sink(env, next_type) &&
2568 !env_type_is_resolved(env, next_type_id))
2569 return env_stack_push(env, next_type, next_type_id);
2571 if (btf_type_is_modifier(next_type)) {
2572 const struct btf_type *resolved_type;
2573 u32 resolved_type_id;
2575 resolved_type_id = next_type_id;
2576 resolved_type = btf_type_id_resolve(btf, &resolved_type_id);
2578 if (btf_type_is_ptr(resolved_type) &&
2579 !env_type_is_resolve_sink(env, resolved_type) &&
2580 !env_type_is_resolved(env, resolved_type_id))
2581 return env_stack_push(env, resolved_type,
2585 /* We must resolve to something concrete at this point, no
2586 * forward types or similar that would resolve to size of
2589 if (!btf_type_id_size(btf, &next_type_id, NULL)) {
2590 btf_verifier_log_type(env, v->t, "Invalid type_id");
2594 env_stack_pop_resolved(env, next_type_id, 0);
2599 static int btf_ptr_resolve(struct btf_verifier_env *env,
2600 const struct resolve_vertex *v)
2602 const struct btf_type *next_type;
2603 const struct btf_type *t = v->t;
2604 u32 next_type_id = t->type;
2605 struct btf *btf = env->btf;
2607 next_type = btf_type_by_id(btf, next_type_id);
2608 if (!next_type || btf_type_is_resolve_source_only(next_type)) {
2609 btf_verifier_log_type(env, v->t, "Invalid type_id");
2613 if (!env_type_is_resolve_sink(env, next_type) &&
2614 !env_type_is_resolved(env, next_type_id))
2615 return env_stack_push(env, next_type, next_type_id);
2617 /* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY,
2618 * the modifier may have stopped resolving when it was resolved
2619 * to a ptr (last-resolved-ptr).
2621 * We now need to continue from the last-resolved-ptr to
2622 * ensure the last-resolved-ptr will not referring back to
2623 * the current ptr (t).
2625 if (btf_type_is_modifier(next_type)) {
2626 const struct btf_type *resolved_type;
2627 u32 resolved_type_id;
2629 resolved_type_id = next_type_id;
2630 resolved_type = btf_type_id_resolve(btf, &resolved_type_id);
2632 if (btf_type_is_ptr(resolved_type) &&
2633 !env_type_is_resolve_sink(env, resolved_type) &&
2634 !env_type_is_resolved(env, resolved_type_id))
2635 return env_stack_push(env, resolved_type,
2639 if (!btf_type_id_size(btf, &next_type_id, NULL)) {
2640 if (env_type_is_resolved(env, next_type_id))
2641 next_type = btf_type_id_resolve(btf, &next_type_id);
2643 if (!btf_type_is_void(next_type) &&
2644 !btf_type_is_fwd(next_type) &&
2645 !btf_type_is_func_proto(next_type)) {
2646 btf_verifier_log_type(env, v->t, "Invalid type_id");
2651 env_stack_pop_resolved(env, next_type_id, 0);
2656 static void btf_modifier_show(const struct btf *btf,
2657 const struct btf_type *t,
2658 u32 type_id, void *data,
2659 u8 bits_offset, struct btf_show *show)
2661 if (btf->resolved_ids)
2662 t = btf_type_id_resolve(btf, &type_id);
2664 t = btf_type_skip_modifiers(btf, type_id, NULL);
2666 btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show);
2669 static void btf_var_show(const struct btf *btf, const struct btf_type *t,
2670 u32 type_id, void *data, u8 bits_offset,
2671 struct btf_show *show)
2673 t = btf_type_id_resolve(btf, &type_id);
2675 btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show);
2678 static void btf_ptr_show(const struct btf *btf, const struct btf_type *t,
2679 u32 type_id, void *data, u8 bits_offset,
2680 struct btf_show *show)
2684 safe_data = btf_show_start_type(show, t, type_id, data);
2688 /* It is a hashed value unless BTF_SHOW_PTR_RAW is specified */
2689 if (show->flags & BTF_SHOW_PTR_RAW)
2690 btf_show_type_value(show, "0x%px", *(void **)safe_data);
2692 btf_show_type_value(show, "0x%p", *(void **)safe_data);
2693 btf_show_end_type(show);
2696 static void btf_ref_type_log(struct btf_verifier_env *env,
2697 const struct btf_type *t)
2699 btf_verifier_log(env, "type_id=%u", t->type);
2702 static struct btf_kind_operations modifier_ops = {
2703 .check_meta = btf_ref_type_check_meta,
2704 .resolve = btf_modifier_resolve,
2705 .check_member = btf_modifier_check_member,
2706 .check_kflag_member = btf_modifier_check_kflag_member,
2707 .log_details = btf_ref_type_log,
2708 .show = btf_modifier_show,
2711 static struct btf_kind_operations ptr_ops = {
2712 .check_meta = btf_ref_type_check_meta,
2713 .resolve = btf_ptr_resolve,
2714 .check_member = btf_ptr_check_member,
2715 .check_kflag_member = btf_generic_check_kflag_member,
2716 .log_details = btf_ref_type_log,
2717 .show = btf_ptr_show,
2720 static s32 btf_fwd_check_meta(struct btf_verifier_env *env,
2721 const struct btf_type *t,
2724 if (btf_type_vlen(t)) {
2725 btf_verifier_log_type(env, t, "vlen != 0");
2730 btf_verifier_log_type(env, t, "type != 0");
2734 /* fwd type must have a valid name */
2736 !btf_name_valid_identifier(env->btf, t->name_off)) {
2737 btf_verifier_log_type(env, t, "Invalid name");
2741 btf_verifier_log_type(env, t, NULL);
2746 static void btf_fwd_type_log(struct btf_verifier_env *env,
2747 const struct btf_type *t)
2749 btf_verifier_log(env, "%s", btf_type_kflag(t) ? "union" : "struct");
2752 static struct btf_kind_operations fwd_ops = {
2753 .check_meta = btf_fwd_check_meta,
2754 .resolve = btf_df_resolve,
2755 .check_member = btf_df_check_member,
2756 .check_kflag_member = btf_df_check_kflag_member,
2757 .log_details = btf_fwd_type_log,
2758 .show = btf_df_show,
2761 static int btf_array_check_member(struct btf_verifier_env *env,
2762 const struct btf_type *struct_type,
2763 const struct btf_member *member,
2764 const struct btf_type *member_type)
2766 u32 struct_bits_off = member->offset;
2767 u32 struct_size, bytes_offset;
2768 u32 array_type_id, array_size;
2769 struct btf *btf = env->btf;
2771 if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
2772 btf_verifier_log_member(env, struct_type, member,
2773 "Member is not byte aligned");
2777 array_type_id = member->type;
2778 btf_type_id_size(btf, &array_type_id, &array_size);
2779 struct_size = struct_type->size;
2780 bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
2781 if (struct_size - bytes_offset < array_size) {
2782 btf_verifier_log_member(env, struct_type, member,
2783 "Member exceeds struct_size");
2790 static s32 btf_array_check_meta(struct btf_verifier_env *env,
2791 const struct btf_type *t,
2794 const struct btf_array *array = btf_type_array(t);
2795 u32 meta_needed = sizeof(*array);
2797 if (meta_left < meta_needed) {
2798 btf_verifier_log_basic(env, t,
2799 "meta_left:%u meta_needed:%u",
2800 meta_left, meta_needed);
2804 /* array type should not have a name */
2806 btf_verifier_log_type(env, t, "Invalid name");
2810 if (btf_type_vlen(t)) {
2811 btf_verifier_log_type(env, t, "vlen != 0");
2815 if (btf_type_kflag(t)) {
2816 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
2821 btf_verifier_log_type(env, t, "size != 0");
2825 /* Array elem type and index type cannot be in type void,
2826 * so !array->type and !array->index_type are not allowed.
2828 if (!array->type || !BTF_TYPE_ID_VALID(array->type)) {
2829 btf_verifier_log_type(env, t, "Invalid elem");
2833 if (!array->index_type || !BTF_TYPE_ID_VALID(array->index_type)) {
2834 btf_verifier_log_type(env, t, "Invalid index");
2838 btf_verifier_log_type(env, t, NULL);
2843 static int btf_array_resolve(struct btf_verifier_env *env,
2844 const struct resolve_vertex *v)
2846 const struct btf_array *array = btf_type_array(v->t);
2847 const struct btf_type *elem_type, *index_type;
2848 u32 elem_type_id, index_type_id;
2849 struct btf *btf = env->btf;
2852 /* Check array->index_type */
2853 index_type_id = array->index_type;
2854 index_type = btf_type_by_id(btf, index_type_id);
2855 if (btf_type_nosize_or_null(index_type) ||
2856 btf_type_is_resolve_source_only(index_type)) {
2857 btf_verifier_log_type(env, v->t, "Invalid index");
2861 if (!env_type_is_resolve_sink(env, index_type) &&
2862 !env_type_is_resolved(env, index_type_id))
2863 return env_stack_push(env, index_type, index_type_id);
2865 index_type = btf_type_id_size(btf, &index_type_id, NULL);
2866 if (!index_type || !btf_type_is_int(index_type) ||
2867 !btf_type_int_is_regular(index_type)) {
2868 btf_verifier_log_type(env, v->t, "Invalid index");
2872 /* Check array->type */
2873 elem_type_id = array->type;
2874 elem_type = btf_type_by_id(btf, elem_type_id);
2875 if (btf_type_nosize_or_null(elem_type) ||
2876 btf_type_is_resolve_source_only(elem_type)) {
2877 btf_verifier_log_type(env, v->t,
2882 if (!env_type_is_resolve_sink(env, elem_type) &&
2883 !env_type_is_resolved(env, elem_type_id))
2884 return env_stack_push(env, elem_type, elem_type_id);
2886 elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size);
2888 btf_verifier_log_type(env, v->t, "Invalid elem");
2892 if (btf_type_is_int(elem_type) && !btf_type_int_is_regular(elem_type)) {
2893 btf_verifier_log_type(env, v->t, "Invalid array of int");
2897 if (array->nelems && elem_size > U32_MAX / array->nelems) {
2898 btf_verifier_log_type(env, v->t,
2899 "Array size overflows U32_MAX");
2903 env_stack_pop_resolved(env, elem_type_id, elem_size * array->nelems);
2908 static void btf_array_log(struct btf_verifier_env *env,
2909 const struct btf_type *t)
2911 const struct btf_array *array = btf_type_array(t);
2913 btf_verifier_log(env, "type_id=%u index_type_id=%u nr_elems=%u",
2914 array->type, array->index_type, array->nelems);
2917 static void __btf_array_show(const struct btf *btf, const struct btf_type *t,
2918 u32 type_id, void *data, u8 bits_offset,
2919 struct btf_show *show)
2921 const struct btf_array *array = btf_type_array(t);
2922 const struct btf_kind_operations *elem_ops;
2923 const struct btf_type *elem_type;
2924 u32 i, elem_size = 0, elem_type_id;
2927 elem_type_id = array->type;
2928 elem_type = btf_type_skip_modifiers(btf, elem_type_id, NULL);
2929 if (elem_type && btf_type_has_size(elem_type))
2930 elem_size = elem_type->size;
2932 if (elem_type && btf_type_is_int(elem_type)) {
2933 u32 int_type = btf_type_int(elem_type);
2935 encoding = BTF_INT_ENCODING(int_type);
2938 * BTF_INT_CHAR encoding never seems to be set for
2939 * char arrays, so if size is 1 and element is
2940 * printable as a char, we'll do that.
2943 encoding = BTF_INT_CHAR;
2946 if (!btf_show_start_array_type(show, t, type_id, encoding, data))
2951 elem_ops = btf_type_ops(elem_type);
2953 for (i = 0; i < array->nelems; i++) {
2955 btf_show_start_array_member(show);
2957 elem_ops->show(btf, elem_type, elem_type_id, data,
2961 btf_show_end_array_member(show);
2963 if (show->state.array_terminated)
2967 btf_show_end_array_type(show);
2970 static void btf_array_show(const struct btf *btf, const struct btf_type *t,
2971 u32 type_id, void *data, u8 bits_offset,
2972 struct btf_show *show)
2974 const struct btf_member *m = show->state.member;
2977 * First check if any members would be shown (are non-zero).
2978 * See comments above "struct btf_show" definition for more
2979 * details on how this works at a high-level.
2981 if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) {
2982 if (!show->state.depth_check) {
2983 show->state.depth_check = show->state.depth + 1;
2984 show->state.depth_to_show = 0;
2986 __btf_array_show(btf, t, type_id, data, bits_offset, show);
2987 show->state.member = m;
2989 if (show->state.depth_check != show->state.depth + 1)
2991 show->state.depth_check = 0;
2993 if (show->state.depth_to_show <= show->state.depth)
2996 * Reaching here indicates we have recursed and found
2997 * non-zero array member(s).
3000 __btf_array_show(btf, t, type_id, data, bits_offset, show);
3003 static struct btf_kind_operations array_ops = {
3004 .check_meta = btf_array_check_meta,
3005 .resolve = btf_array_resolve,
3006 .check_member = btf_array_check_member,
3007 .check_kflag_member = btf_generic_check_kflag_member,
3008 .log_details = btf_array_log,
3009 .show = btf_array_show,
3012 static int btf_struct_check_member(struct btf_verifier_env *env,
3013 const struct btf_type *struct_type,
3014 const struct btf_member *member,
3015 const struct btf_type *member_type)
3017 u32 struct_bits_off = member->offset;
3018 u32 struct_size, bytes_offset;
3020 if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
3021 btf_verifier_log_member(env, struct_type, member,
3022 "Member is not byte aligned");
3026 struct_size = struct_type->size;
3027 bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
3028 if (struct_size - bytes_offset < member_type->size) {
3029 btf_verifier_log_member(env, struct_type, member,
3030 "Member exceeds struct_size");
3037 static s32 btf_struct_check_meta(struct btf_verifier_env *env,
3038 const struct btf_type *t,
3041 bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION;
3042 const struct btf_member *member;
3043 u32 meta_needed, last_offset;
3044 struct btf *btf = env->btf;
3045 u32 struct_size = t->size;
3049 meta_needed = btf_type_vlen(t) * sizeof(*member);
3050 if (meta_left < meta_needed) {
3051 btf_verifier_log_basic(env, t,
3052 "meta_left:%u meta_needed:%u",
3053 meta_left, meta_needed);
3057 /* struct type either no name or a valid one */
3059 !btf_name_valid_identifier(env->btf, t->name_off)) {
3060 btf_verifier_log_type(env, t, "Invalid name");
3064 btf_verifier_log_type(env, t, NULL);
3067 for_each_member(i, t, member) {
3068 if (!btf_name_offset_valid(btf, member->name_off)) {
3069 btf_verifier_log_member(env, t, member,
3070 "Invalid member name_offset:%u",
3075 /* struct member either no name or a valid one */
3076 if (member->name_off &&
3077 !btf_name_valid_identifier(btf, member->name_off)) {
3078 btf_verifier_log_member(env, t, member, "Invalid name");
3081 /* A member cannot be in type void */
3082 if (!member->type || !BTF_TYPE_ID_VALID(member->type)) {
3083 btf_verifier_log_member(env, t, member,
3088 offset = __btf_member_bit_offset(t, member);
3089 if (is_union && offset) {
3090 btf_verifier_log_member(env, t, member,
3091 "Invalid member bits_offset");
3096 * ">" instead of ">=" because the last member could be
3099 if (last_offset > offset) {
3100 btf_verifier_log_member(env, t, member,
3101 "Invalid member bits_offset");
3105 if (BITS_ROUNDUP_BYTES(offset) > struct_size) {
3106 btf_verifier_log_member(env, t, member,
3107 "Member bits_offset exceeds its struct size");
3111 btf_verifier_log_member(env, t, member, NULL);
3112 last_offset = offset;
3118 static int btf_struct_resolve(struct btf_verifier_env *env,
3119 const struct resolve_vertex *v)
3121 const struct btf_member *member;
3125 /* Before continue resolving the next_member,
3126 * ensure the last member is indeed resolved to a
3127 * type with size info.
3129 if (v->next_member) {
3130 const struct btf_type *last_member_type;
3131 const struct btf_member *last_member;
3132 u16 last_member_type_id;
3134 last_member = btf_type_member(v->t) + v->next_member - 1;
3135 last_member_type_id = last_member->type;
3136 if (WARN_ON_ONCE(!env_type_is_resolved(env,
3137 last_member_type_id)))
3140 last_member_type = btf_type_by_id(env->btf,
3141 last_member_type_id);
3142 if (btf_type_kflag(v->t))
3143 err = btf_type_ops(last_member_type)->check_kflag_member(env, v->t,
3147 err = btf_type_ops(last_member_type)->check_member(env, v->t,
3154 for_each_member_from(i, v->next_member, v->t, member) {
3155 u32 member_type_id = member->type;
3156 const struct btf_type *member_type = btf_type_by_id(env->btf,
3159 if (btf_type_nosize_or_null(member_type) ||
3160 btf_type_is_resolve_source_only(member_type)) {
3161 btf_verifier_log_member(env, v->t, member,
3166 if (!env_type_is_resolve_sink(env, member_type) &&
3167 !env_type_is_resolved(env, member_type_id)) {
3168 env_stack_set_next_member(env, i + 1);
3169 return env_stack_push(env, member_type, member_type_id);
3172 if (btf_type_kflag(v->t))
3173 err = btf_type_ops(member_type)->check_kflag_member(env, v->t,
3177 err = btf_type_ops(member_type)->check_member(env, v->t,
3184 env_stack_pop_resolved(env, 0, 0);
3189 static void btf_struct_log(struct btf_verifier_env *env,
3190 const struct btf_type *t)
3192 btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
3195 enum btf_field_type {
3196 BTF_FIELD_SPIN_LOCK,
3202 BTF_FIELD_IGNORE = 0,
3203 BTF_FIELD_FOUND = 1,
3206 struct btf_field_info {
3209 enum bpf_kptr_type type;
3212 static int btf_find_struct(const struct btf *btf, const struct btf_type *t,
3213 u32 off, int sz, struct btf_field_info *info)
3215 if (!__btf_type_is_struct(t))
3216 return BTF_FIELD_IGNORE;
3218 return BTF_FIELD_IGNORE;
3220 return BTF_FIELD_FOUND;
3223 static int btf_find_kptr(const struct btf *btf, const struct btf_type *t,
3224 u32 off, int sz, struct btf_field_info *info)
3226 enum bpf_kptr_type type;
3229 /* For PTR, sz is always == 8 */
3230 if (!btf_type_is_ptr(t))
3231 return BTF_FIELD_IGNORE;
3232 t = btf_type_by_id(btf, t->type);
3234 if (!btf_type_is_type_tag(t))
3235 return BTF_FIELD_IGNORE;
3236 /* Reject extra tags */
3237 if (btf_type_is_type_tag(btf_type_by_id(btf, t->type)))
3239 if (!strcmp("kptr", __btf_name_by_offset(btf, t->name_off)))
3240 type = BPF_KPTR_UNREF;
3241 else if (!strcmp("kptr_ref", __btf_name_by_offset(btf, t->name_off)))
3242 type = BPF_KPTR_REF;
3246 /* Get the base type */
3247 t = btf_type_skip_modifiers(btf, t->type, &res_id);
3248 /* Only pointer to struct is allowed */
3249 if (!__btf_type_is_struct(t))
3252 info->type_id = res_id;
3255 return BTF_FIELD_FOUND;
3258 static int btf_find_struct_field(const struct btf *btf, const struct btf_type *t,
3259 const char *name, int sz, int align,
3260 enum btf_field_type field_type,
3261 struct btf_field_info *info, int info_cnt)
3263 const struct btf_member *member;
3264 struct btf_field_info tmp;
3268 for_each_member(i, t, member) {
3269 const struct btf_type *member_type = btf_type_by_id(btf,
3272 if (name && strcmp(__btf_name_by_offset(btf, member_type->name_off), name))
3275 off = __btf_member_bit_offset(t, member);
3277 /* valid C code cannot generate such BTF */
3283 switch (field_type) {
3284 case BTF_FIELD_SPIN_LOCK:
3285 case BTF_FIELD_TIMER:
3286 ret = btf_find_struct(btf, member_type, off, sz,
3287 idx < info_cnt ? &info[idx] : &tmp);
3291 case BTF_FIELD_KPTR:
3292 ret = btf_find_kptr(btf, member_type, off, sz,
3293 idx < info_cnt ? &info[idx] : &tmp);
3301 if (ret == BTF_FIELD_IGNORE)
3303 if (idx >= info_cnt)
3310 static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t,
3311 const char *name, int sz, int align,
3312 enum btf_field_type field_type,
3313 struct btf_field_info *info, int info_cnt)
3315 const struct btf_var_secinfo *vsi;
3316 struct btf_field_info tmp;
3320 for_each_vsi(i, t, vsi) {
3321 const struct btf_type *var = btf_type_by_id(btf, vsi->type);
3322 const struct btf_type *var_type = btf_type_by_id(btf, var->type);
3326 if (name && strcmp(__btf_name_by_offset(btf, var_type->name_off), name))
3328 if (vsi->size != sz)
3333 switch (field_type) {
3334 case BTF_FIELD_SPIN_LOCK:
3335 case BTF_FIELD_TIMER:
3336 ret = btf_find_struct(btf, var_type, off, sz,
3337 idx < info_cnt ? &info[idx] : &tmp);
3341 case BTF_FIELD_KPTR:
3342 ret = btf_find_kptr(btf, var_type, off, sz,
3343 idx < info_cnt ? &info[idx] : &tmp);
3351 if (ret == BTF_FIELD_IGNORE)
3353 if (idx >= info_cnt)
3360 static int btf_find_field(const struct btf *btf, const struct btf_type *t,
3361 enum btf_field_type field_type,
3362 struct btf_field_info *info, int info_cnt)
3367 switch (field_type) {
3368 case BTF_FIELD_SPIN_LOCK:
3369 name = "bpf_spin_lock";
3370 sz = sizeof(struct bpf_spin_lock);
3371 align = __alignof__(struct bpf_spin_lock);
3373 case BTF_FIELD_TIMER:
3375 sz = sizeof(struct bpf_timer);
3376 align = __alignof__(struct bpf_timer);
3378 case BTF_FIELD_KPTR:
3387 if (__btf_type_is_struct(t))
3388 return btf_find_struct_field(btf, t, name, sz, align, field_type, info, info_cnt);
3389 else if (btf_type_is_datasec(t))
3390 return btf_find_datasec_var(btf, t, name, sz, align, field_type, info, info_cnt);
3394 /* find 'struct bpf_spin_lock' in map value.
3395 * return >= 0 offset if found
3396 * and < 0 in case of error
3398 int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t)
3400 struct btf_field_info info;
3403 ret = btf_find_field(btf, t, BTF_FIELD_SPIN_LOCK, &info, 1);
3411 int btf_find_timer(const struct btf *btf, const struct btf_type *t)
3413 struct btf_field_info info;
3416 ret = btf_find_field(btf, t, BTF_FIELD_TIMER, &info, 1);
3424 struct bpf_map_value_off *btf_parse_kptrs(const struct btf *btf,
3425 const struct btf_type *t)
3427 struct btf_field_info info_arr[BPF_MAP_VALUE_OFF_MAX];
3428 struct bpf_map_value_off *tab;
3429 struct btf *kernel_btf = NULL;
3430 struct module *mod = NULL;
3433 ret = btf_find_field(btf, t, BTF_FIELD_KPTR, info_arr, ARRAY_SIZE(info_arr));
3435 return ERR_PTR(ret);
3440 tab = kzalloc(offsetof(struct bpf_map_value_off, off[nr_off]), GFP_KERNEL | __GFP_NOWARN);
3442 return ERR_PTR(-ENOMEM);
3444 for (i = 0; i < nr_off; i++) {
3445 const struct btf_type *t;
3448 /* Find type in map BTF, and use it to look up the matching type
3449 * in vmlinux or module BTFs, by name and kind.
3451 t = btf_type_by_id(btf, info_arr[i].type_id);
3452 id = bpf_find_btf_id(__btf_name_by_offset(btf, t->name_off), BTF_INFO_KIND(t->info),
3459 /* Find and stash the function pointer for the destruction function that
3460 * needs to be eventually invoked from the map free path.
3462 if (info_arr[i].type == BPF_KPTR_REF) {
3463 const struct btf_type *dtor_func;
3464 const char *dtor_func_name;
3468 /* This call also serves as a whitelist of allowed objects that
3469 * can be used as a referenced pointer and be stored in a map at
3472 dtor_btf_id = btf_find_dtor_kfunc(kernel_btf, id);
3473 if (dtor_btf_id < 0) {
3478 dtor_func = btf_type_by_id(kernel_btf, dtor_btf_id);
3484 if (btf_is_module(kernel_btf)) {
3485 mod = btf_try_get_module(kernel_btf);
3492 /* We already verified dtor_func to be btf_type_is_func
3493 * in register_btf_id_dtor_kfuncs.
3495 dtor_func_name = __btf_name_by_offset(kernel_btf, dtor_func->name_off);
3496 addr = kallsyms_lookup_name(dtor_func_name);
3501 tab->off[i].kptr.dtor = (void *)addr;
3504 tab->off[i].offset = info_arr[i].off;
3505 tab->off[i].type = info_arr[i].type;
3506 tab->off[i].kptr.btf_id = id;
3507 tab->off[i].kptr.btf = kernel_btf;
3508 tab->off[i].kptr.module = mod;
3510 tab->nr_off = nr_off;
3515 btf_put(kernel_btf);
3518 btf_put(tab->off[i].kptr.btf);
3519 if (tab->off[i].kptr.module)
3520 module_put(tab->off[i].kptr.module);
3523 return ERR_PTR(ret);
3526 static void __btf_struct_show(const struct btf *btf, const struct btf_type *t,
3527 u32 type_id, void *data, u8 bits_offset,
3528 struct btf_show *show)
3530 const struct btf_member *member;
3534 safe_data = btf_show_start_struct_type(show, t, type_id, data);
3538 for_each_member(i, t, member) {
3539 const struct btf_type *member_type = btf_type_by_id(btf,
3541 const struct btf_kind_operations *ops;
3542 u32 member_offset, bitfield_size;
3546 btf_show_start_member(show, member);
3548 member_offset = __btf_member_bit_offset(t, member);
3549 bitfield_size = __btf_member_bitfield_size(t, member);
3550 bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset);
3551 bits8_offset = BITS_PER_BYTE_MASKED(member_offset);
3552 if (bitfield_size) {
3553 safe_data = btf_show_start_type(show, member_type,
3555 data + bytes_offset);
3557 btf_bitfield_show(safe_data,
3559 bitfield_size, show);
3560 btf_show_end_type(show);
3562 ops = btf_type_ops(member_type);
3563 ops->show(btf, member_type, member->type,
3564 data + bytes_offset, bits8_offset, show);
3567 btf_show_end_member(show);
3570 btf_show_end_struct_type(show);
3573 static void btf_struct_show(const struct btf *btf, const struct btf_type *t,
3574 u32 type_id, void *data, u8 bits_offset,
3575 struct btf_show *show)
3577 const struct btf_member *m = show->state.member;
3580 * First check if any members would be shown (are non-zero).
3581 * See comments above "struct btf_show" definition for more
3582 * details on how this works at a high-level.
3584 if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) {
3585 if (!show->state.depth_check) {
3586 show->state.depth_check = show->state.depth + 1;
3587 show->state.depth_to_show = 0;
3589 __btf_struct_show(btf, t, type_id, data, bits_offset, show);
3590 /* Restore saved member data here */
3591 show->state.member = m;
3592 if (show->state.depth_check != show->state.depth + 1)
3594 show->state.depth_check = 0;
3596 if (show->state.depth_to_show <= show->state.depth)
3599 * Reaching here indicates we have recursed and found
3600 * non-zero child values.
3604 __btf_struct_show(btf, t, type_id, data, bits_offset, show);
3607 static struct btf_kind_operations struct_ops = {
3608 .check_meta = btf_struct_check_meta,
3609 .resolve = btf_struct_resolve,
3610 .check_member = btf_struct_check_member,
3611 .check_kflag_member = btf_generic_check_kflag_member,
3612 .log_details = btf_struct_log,
3613 .show = btf_struct_show,
3616 static int btf_enum_check_member(struct btf_verifier_env *env,
3617 const struct btf_type *struct_type,
3618 const struct btf_member *member,
3619 const struct btf_type *member_type)
3621 u32 struct_bits_off = member->offset;
3622 u32 struct_size, bytes_offset;
3624 if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
3625 btf_verifier_log_member(env, struct_type, member,
3626 "Member is not byte aligned");
3630 struct_size = struct_type->size;
3631 bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
3632 if (struct_size - bytes_offset < member_type->size) {
3633 btf_verifier_log_member(env, struct_type, member,
3634 "Member exceeds struct_size");
3641 static int btf_enum_check_kflag_member(struct btf_verifier_env *env,
3642 const struct btf_type *struct_type,
3643 const struct btf_member *member,
3644 const struct btf_type *member_type)
3646 u32 struct_bits_off, nr_bits, bytes_end, struct_size;
3647 u32 int_bitsize = sizeof(int) * BITS_PER_BYTE;
3649 struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset);
3650 nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset);
3652 if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
3653 btf_verifier_log_member(env, struct_type, member,
3654 "Member is not byte aligned");
3658 nr_bits = int_bitsize;
3659 } else if (nr_bits > int_bitsize) {
3660 btf_verifier_log_member(env, struct_type, member,
3661 "Invalid member bitfield_size");
3665 struct_size = struct_type->size;
3666 bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits);
3667 if (struct_size < bytes_end) {
3668 btf_verifier_log_member(env, struct_type, member,
3669 "Member exceeds struct_size");
3676 static s32 btf_enum_check_meta(struct btf_verifier_env *env,
3677 const struct btf_type *t,
3680 const struct btf_enum *enums = btf_type_enum(t);
3681 struct btf *btf = env->btf;
3682 const char *fmt_str;
3686 nr_enums = btf_type_vlen(t);
3687 meta_needed = nr_enums * sizeof(*enums);
3689 if (meta_left < meta_needed) {
3690 btf_verifier_log_basic(env, t,
3691 "meta_left:%u meta_needed:%u",
3692 meta_left, meta_needed);
3696 if (t->size > 8 || !is_power_of_2(t->size)) {
3697 btf_verifier_log_type(env, t, "Unexpected size");
3701 /* enum type either no name or a valid one */
3703 !btf_name_valid_identifier(env->btf, t->name_off)) {
3704 btf_verifier_log_type(env, t, "Invalid name");
3708 btf_verifier_log_type(env, t, NULL);
3710 for (i = 0; i < nr_enums; i++) {
3711 if (!btf_name_offset_valid(btf, enums[i].name_off)) {
3712 btf_verifier_log(env, "\tInvalid name_offset:%u",
3717 /* enum member must have a valid name */
3718 if (!enums[i].name_off ||
3719 !btf_name_valid_identifier(btf, enums[i].name_off)) {
3720 btf_verifier_log_type(env, t, "Invalid name");
3724 if (env->log.level == BPF_LOG_KERNEL)
3726 fmt_str = btf_type_kflag(t) ? "\t%s val=%d\n" : "\t%s val=%u\n";
3727 btf_verifier_log(env, fmt_str,
3728 __btf_name_by_offset(btf, enums[i].name_off),
3735 static void btf_enum_log(struct btf_verifier_env *env,
3736 const struct btf_type *t)
3738 btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
3741 static void btf_enum_show(const struct btf *btf, const struct btf_type *t,
3742 u32 type_id, void *data, u8 bits_offset,
3743 struct btf_show *show)
3745 const struct btf_enum *enums = btf_type_enum(t);
3746 u32 i, nr_enums = btf_type_vlen(t);
3750 safe_data = btf_show_start_type(show, t, type_id, data);
3754 v = *(int *)safe_data;
3756 for (i = 0; i < nr_enums; i++) {
3757 if (v != enums[i].val)
3760 btf_show_type_value(show, "%s",
3761 __btf_name_by_offset(btf,
3762 enums[i].name_off));
3764 btf_show_end_type(show);
3768 if (btf_type_kflag(t))
3769 btf_show_type_value(show, "%d", v);
3771 btf_show_type_value(show, "%u", v);
3772 btf_show_end_type(show);
3775 static struct btf_kind_operations enum_ops = {
3776 .check_meta = btf_enum_check_meta,
3777 .resolve = btf_df_resolve,
3778 .check_member = btf_enum_check_member,
3779 .check_kflag_member = btf_enum_check_kflag_member,
3780 .log_details = btf_enum_log,
3781 .show = btf_enum_show,
3784 static s32 btf_enum64_check_meta(struct btf_verifier_env *env,
3785 const struct btf_type *t,
3788 const struct btf_enum64 *enums = btf_type_enum64(t);
3789 struct btf *btf = env->btf;
3790 const char *fmt_str;
3794 nr_enums = btf_type_vlen(t);
3795 meta_needed = nr_enums * sizeof(*enums);
3797 if (meta_left < meta_needed) {
3798 btf_verifier_log_basic(env, t,
3799 "meta_left:%u meta_needed:%u",
3800 meta_left, meta_needed);
3804 if (t->size > 8 || !is_power_of_2(t->size)) {
3805 btf_verifier_log_type(env, t, "Unexpected size");
3809 /* enum type either no name or a valid one */
3811 !btf_name_valid_identifier(env->btf, t->name_off)) {
3812 btf_verifier_log_type(env, t, "Invalid name");
3816 btf_verifier_log_type(env, t, NULL);
3818 for (i = 0; i < nr_enums; i++) {
3819 if (!btf_name_offset_valid(btf, enums[i].name_off)) {
3820 btf_verifier_log(env, "\tInvalid name_offset:%u",
3825 /* enum member must have a valid name */
3826 if (!enums[i].name_off ||
3827 !btf_name_valid_identifier(btf, enums[i].name_off)) {
3828 btf_verifier_log_type(env, t, "Invalid name");
3832 if (env->log.level == BPF_LOG_KERNEL)
3835 fmt_str = btf_type_kflag(t) ? "\t%s val=%lld\n" : "\t%s val=%llu\n";
3836 btf_verifier_log(env, fmt_str,
3837 __btf_name_by_offset(btf, enums[i].name_off),
3838 btf_enum64_value(enums + i));
3844 static void btf_enum64_show(const struct btf *btf, const struct btf_type *t,
3845 u32 type_id, void *data, u8 bits_offset,
3846 struct btf_show *show)
3848 const struct btf_enum64 *enums = btf_type_enum64(t);
3849 u32 i, nr_enums = btf_type_vlen(t);
3853 safe_data = btf_show_start_type(show, t, type_id, data);
3857 v = *(u64 *)safe_data;
3859 for (i = 0; i < nr_enums; i++) {
3860 if (v != btf_enum64_value(enums + i))
3863 btf_show_type_value(show, "%s",
3864 __btf_name_by_offset(btf,
3865 enums[i].name_off));
3867 btf_show_end_type(show);
3871 if (btf_type_kflag(t))
3872 btf_show_type_value(show, "%lld", v);
3874 btf_show_type_value(show, "%llu", v);
3875 btf_show_end_type(show);
3878 static struct btf_kind_operations enum64_ops = {
3879 .check_meta = btf_enum64_check_meta,
3880 .resolve = btf_df_resolve,
3881 .check_member = btf_enum_check_member,
3882 .check_kflag_member = btf_enum_check_kflag_member,
3883 .log_details = btf_enum_log,
3884 .show = btf_enum64_show,
3887 static s32 btf_func_proto_check_meta(struct btf_verifier_env *env,
3888 const struct btf_type *t,
3891 u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param);
3893 if (meta_left < meta_needed) {
3894 btf_verifier_log_basic(env, t,
3895 "meta_left:%u meta_needed:%u",
3896 meta_left, meta_needed);
3901 btf_verifier_log_type(env, t, "Invalid name");
3905 if (btf_type_kflag(t)) {
3906 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
3910 btf_verifier_log_type(env, t, NULL);
3915 static void btf_func_proto_log(struct btf_verifier_env *env,
3916 const struct btf_type *t)
3918 const struct btf_param *args = (const struct btf_param *)(t + 1);
3919 u16 nr_args = btf_type_vlen(t), i;
3921 btf_verifier_log(env, "return=%u args=(", t->type);
3923 btf_verifier_log(env, "void");
3927 if (nr_args == 1 && !args[0].type) {
3928 /* Only one vararg */
3929 btf_verifier_log(env, "vararg");
3933 btf_verifier_log(env, "%u %s", args[0].type,
3934 __btf_name_by_offset(env->btf,
3936 for (i = 1; i < nr_args - 1; i++)
3937 btf_verifier_log(env, ", %u %s", args[i].type,
3938 __btf_name_by_offset(env->btf,
3942 const struct btf_param *last_arg = &args[nr_args - 1];
3945 btf_verifier_log(env, ", %u %s", last_arg->type,
3946 __btf_name_by_offset(env->btf,
3947 last_arg->name_off));
3949 btf_verifier_log(env, ", vararg");
3953 btf_verifier_log(env, ")");
3956 static struct btf_kind_operations func_proto_ops = {
3957 .check_meta = btf_func_proto_check_meta,
3958 .resolve = btf_df_resolve,
3960 * BTF_KIND_FUNC_PROTO cannot be directly referred by
3961 * a struct's member.
3963 * It should be a function pointer instead.
3964 * (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO)
3966 * Hence, there is no btf_func_check_member().
3968 .check_member = btf_df_check_member,
3969 .check_kflag_member = btf_df_check_kflag_member,
3970 .log_details = btf_func_proto_log,
3971 .show = btf_df_show,
3974 static s32 btf_func_check_meta(struct btf_verifier_env *env,
3975 const struct btf_type *t,
3979 !btf_name_valid_identifier(env->btf, t->name_off)) {
3980 btf_verifier_log_type(env, t, "Invalid name");
3984 if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) {
3985 btf_verifier_log_type(env, t, "Invalid func linkage");
3989 if (btf_type_kflag(t)) {
3990 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
3994 btf_verifier_log_type(env, t, NULL);
3999 static int btf_func_resolve(struct btf_verifier_env *env,
4000 const struct resolve_vertex *v)
4002 const struct btf_type *t = v->t;
4003 u32 next_type_id = t->type;
4006 err = btf_func_check(env, t);
4010 env_stack_pop_resolved(env, next_type_id, 0);
4014 static struct btf_kind_operations func_ops = {
4015 .check_meta = btf_func_check_meta,
4016 .resolve = btf_func_resolve,
4017 .check_member = btf_df_check_member,
4018 .check_kflag_member = btf_df_check_kflag_member,
4019 .log_details = btf_ref_type_log,
4020 .show = btf_df_show,
4023 static s32 btf_var_check_meta(struct btf_verifier_env *env,
4024 const struct btf_type *t,
4027 const struct btf_var *var;
4028 u32 meta_needed = sizeof(*var);
4030 if (meta_left < meta_needed) {
4031 btf_verifier_log_basic(env, t,
4032 "meta_left:%u meta_needed:%u",
4033 meta_left, meta_needed);
4037 if (btf_type_vlen(t)) {
4038 btf_verifier_log_type(env, t, "vlen != 0");
4042 if (btf_type_kflag(t)) {
4043 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
4048 !__btf_name_valid(env->btf, t->name_off, true)) {
4049 btf_verifier_log_type(env, t, "Invalid name");
4053 /* A var cannot be in type void */
4054 if (!t->type || !BTF_TYPE_ID_VALID(t->type)) {
4055 btf_verifier_log_type(env, t, "Invalid type_id");
4059 var = btf_type_var(t);
4060 if (var->linkage != BTF_VAR_STATIC &&
4061 var->linkage != BTF_VAR_GLOBAL_ALLOCATED) {
4062 btf_verifier_log_type(env, t, "Linkage not supported");
4066 btf_verifier_log_type(env, t, NULL);
4071 static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t)
4073 const struct btf_var *var = btf_type_var(t);
4075 btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage);
4078 static const struct btf_kind_operations var_ops = {
4079 .check_meta = btf_var_check_meta,
4080 .resolve = btf_var_resolve,
4081 .check_member = btf_df_check_member,
4082 .check_kflag_member = btf_df_check_kflag_member,
4083 .log_details = btf_var_log,
4084 .show = btf_var_show,
4087 static s32 btf_datasec_check_meta(struct btf_verifier_env *env,
4088 const struct btf_type *t,
4091 const struct btf_var_secinfo *vsi;
4092 u64 last_vsi_end_off = 0, sum = 0;
4095 meta_needed = btf_type_vlen(t) * sizeof(*vsi);
4096 if (meta_left < meta_needed) {
4097 btf_verifier_log_basic(env, t,
4098 "meta_left:%u meta_needed:%u",
4099 meta_left, meta_needed);
4104 btf_verifier_log_type(env, t, "size == 0");
4108 if (btf_type_kflag(t)) {
4109 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
4114 !btf_name_valid_section(env->btf, t->name_off)) {
4115 btf_verifier_log_type(env, t, "Invalid name");
4119 btf_verifier_log_type(env, t, NULL);
4121 for_each_vsi(i, t, vsi) {
4122 /* A var cannot be in type void */
4123 if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) {
4124 btf_verifier_log_vsi(env, t, vsi,
4129 if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) {
4130 btf_verifier_log_vsi(env, t, vsi,
4135 if (!vsi->size || vsi->size > t->size) {
4136 btf_verifier_log_vsi(env, t, vsi,
4141 last_vsi_end_off = vsi->offset + vsi->size;
4142 if (last_vsi_end_off > t->size) {
4143 btf_verifier_log_vsi(env, t, vsi,
4144 "Invalid offset+size");
4148 btf_verifier_log_vsi(env, t, vsi, NULL);
4152 if (t->size < sum) {
4153 btf_verifier_log_type(env, t, "Invalid btf_info size");
4160 static int btf_datasec_resolve(struct btf_verifier_env *env,
4161 const struct resolve_vertex *v)
4163 const struct btf_var_secinfo *vsi;
4164 struct btf *btf = env->btf;
4167 for_each_vsi_from(i, v->next_member, v->t, vsi) {
4168 u32 var_type_id = vsi->type, type_id, type_size = 0;
4169 const struct btf_type *var_type = btf_type_by_id(env->btf,
4171 if (!var_type || !btf_type_is_var(var_type)) {
4172 btf_verifier_log_vsi(env, v->t, vsi,
4173 "Not a VAR kind member");
4177 if (!env_type_is_resolve_sink(env, var_type) &&
4178 !env_type_is_resolved(env, var_type_id)) {
4179 env_stack_set_next_member(env, i + 1);
4180 return env_stack_push(env, var_type, var_type_id);
4183 type_id = var_type->type;
4184 if (!btf_type_id_size(btf, &type_id, &type_size)) {
4185 btf_verifier_log_vsi(env, v->t, vsi, "Invalid type");
4189 if (vsi->size < type_size) {
4190 btf_verifier_log_vsi(env, v->t, vsi, "Invalid size");
4195 env_stack_pop_resolved(env, 0, 0);
4199 static void btf_datasec_log(struct btf_verifier_env *env,
4200 const struct btf_type *t)
4202 btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
4205 static void btf_datasec_show(const struct btf *btf,
4206 const struct btf_type *t, u32 type_id,
4207 void *data, u8 bits_offset,
4208 struct btf_show *show)
4210 const struct btf_var_secinfo *vsi;
4211 const struct btf_type *var;
4214 if (!btf_show_start_type(show, t, type_id, data))
4217 btf_show_type_value(show, "section (\"%s\") = {",
4218 __btf_name_by_offset(btf, t->name_off));
4219 for_each_vsi(i, t, vsi) {
4220 var = btf_type_by_id(btf, vsi->type);
4222 btf_show(show, ",");
4223 btf_type_ops(var)->show(btf, var, vsi->type,
4224 data + vsi->offset, bits_offset, show);
4226 btf_show_end_type(show);
4229 static const struct btf_kind_operations datasec_ops = {
4230 .check_meta = btf_datasec_check_meta,
4231 .resolve = btf_datasec_resolve,
4232 .check_member = btf_df_check_member,
4233 .check_kflag_member = btf_df_check_kflag_member,
4234 .log_details = btf_datasec_log,
4235 .show = btf_datasec_show,
4238 static s32 btf_float_check_meta(struct btf_verifier_env *env,
4239 const struct btf_type *t,
4242 if (btf_type_vlen(t)) {
4243 btf_verifier_log_type(env, t, "vlen != 0");
4247 if (btf_type_kflag(t)) {
4248 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
4252 if (t->size != 2 && t->size != 4 && t->size != 8 && t->size != 12 &&
4254 btf_verifier_log_type(env, t, "Invalid type_size");
4258 btf_verifier_log_type(env, t, NULL);
4263 static int btf_float_check_member(struct btf_verifier_env *env,
4264 const struct btf_type *struct_type,
4265 const struct btf_member *member,
4266 const struct btf_type *member_type)
4268 u64 start_offset_bytes;
4269 u64 end_offset_bytes;
4274 /* Different architectures have different alignment requirements, so
4275 * here we check only for the reasonable minimum. This way we ensure
4276 * that types after CO-RE can pass the kernel BTF verifier.
4278 align_bytes = min_t(u64, sizeof(void *), member_type->size);
4279 align_bits = align_bytes * BITS_PER_BYTE;
4280 div64_u64_rem(member->offset, align_bits, &misalign_bits);
4281 if (misalign_bits) {
4282 btf_verifier_log_member(env, struct_type, member,
4283 "Member is not properly aligned");
4287 start_offset_bytes = member->offset / BITS_PER_BYTE;
4288 end_offset_bytes = start_offset_bytes + member_type->size;
4289 if (end_offset_bytes > struct_type->size) {
4290 btf_verifier_log_member(env, struct_type, member,
4291 "Member exceeds struct_size");
4298 static void btf_float_log(struct btf_verifier_env *env,
4299 const struct btf_type *t)
4301 btf_verifier_log(env, "size=%u", t->size);
4304 static const struct btf_kind_operations float_ops = {
4305 .check_meta = btf_float_check_meta,
4306 .resolve = btf_df_resolve,
4307 .check_member = btf_float_check_member,
4308 .check_kflag_member = btf_generic_check_kflag_member,
4309 .log_details = btf_float_log,
4310 .show = btf_df_show,
4313 static s32 btf_decl_tag_check_meta(struct btf_verifier_env *env,
4314 const struct btf_type *t,
4317 const struct btf_decl_tag *tag;
4318 u32 meta_needed = sizeof(*tag);
4322 if (meta_left < meta_needed) {
4323 btf_verifier_log_basic(env, t,
4324 "meta_left:%u meta_needed:%u",
4325 meta_left, meta_needed);
4329 value = btf_name_by_offset(env->btf, t->name_off);
4330 if (!value || !value[0]) {
4331 btf_verifier_log_type(env, t, "Invalid value");
4335 if (btf_type_vlen(t)) {
4336 btf_verifier_log_type(env, t, "vlen != 0");
4340 if (btf_type_kflag(t)) {
4341 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
4345 component_idx = btf_type_decl_tag(t)->component_idx;
4346 if (component_idx < -1) {
4347 btf_verifier_log_type(env, t, "Invalid component_idx");
4351 btf_verifier_log_type(env, t, NULL);
4356 static int btf_decl_tag_resolve(struct btf_verifier_env *env,
4357 const struct resolve_vertex *v)
4359 const struct btf_type *next_type;
4360 const struct btf_type *t = v->t;
4361 u32 next_type_id = t->type;
4362 struct btf *btf = env->btf;
4366 next_type = btf_type_by_id(btf, next_type_id);
4367 if (!next_type || !btf_type_is_decl_tag_target(next_type)) {
4368 btf_verifier_log_type(env, v->t, "Invalid type_id");
4372 if (!env_type_is_resolve_sink(env, next_type) &&
4373 !env_type_is_resolved(env, next_type_id))
4374 return env_stack_push(env, next_type, next_type_id);
4376 component_idx = btf_type_decl_tag(t)->component_idx;
4377 if (component_idx != -1) {
4378 if (btf_type_is_var(next_type) || btf_type_is_typedef(next_type)) {
4379 btf_verifier_log_type(env, v->t, "Invalid component_idx");
4383 if (btf_type_is_struct(next_type)) {
4384 vlen = btf_type_vlen(next_type);
4386 /* next_type should be a function */
4387 next_type = btf_type_by_id(btf, next_type->type);
4388 vlen = btf_type_vlen(next_type);
4391 if ((u32)component_idx >= vlen) {
4392 btf_verifier_log_type(env, v->t, "Invalid component_idx");
4397 env_stack_pop_resolved(env, next_type_id, 0);
4402 static void btf_decl_tag_log(struct btf_verifier_env *env, const struct btf_type *t)
4404 btf_verifier_log(env, "type=%u component_idx=%d", t->type,
4405 btf_type_decl_tag(t)->component_idx);
4408 static const struct btf_kind_operations decl_tag_ops = {
4409 .check_meta = btf_decl_tag_check_meta,
4410 .resolve = btf_decl_tag_resolve,
4411 .check_member = btf_df_check_member,
4412 .check_kflag_member = btf_df_check_kflag_member,
4413 .log_details = btf_decl_tag_log,
4414 .show = btf_df_show,
4417 static int btf_func_proto_check(struct btf_verifier_env *env,
4418 const struct btf_type *t)
4420 const struct btf_type *ret_type;
4421 const struct btf_param *args;
4422 const struct btf *btf;
4427 args = (const struct btf_param *)(t + 1);
4428 nr_args = btf_type_vlen(t);
4430 /* Check func return type which could be "void" (t->type == 0) */
4432 u32 ret_type_id = t->type;
4434 ret_type = btf_type_by_id(btf, ret_type_id);
4436 btf_verifier_log_type(env, t, "Invalid return type");
4440 if (btf_type_needs_resolve(ret_type) &&
4441 !env_type_is_resolved(env, ret_type_id)) {
4442 err = btf_resolve(env, ret_type, ret_type_id);
4447 /* Ensure the return type is a type that has a size */
4448 if (!btf_type_id_size(btf, &ret_type_id, NULL)) {
4449 btf_verifier_log_type(env, t, "Invalid return type");
4457 /* Last func arg type_id could be 0 if it is a vararg */
4458 if (!args[nr_args - 1].type) {
4459 if (args[nr_args - 1].name_off) {
4460 btf_verifier_log_type(env, t, "Invalid arg#%u",
4468 for (i = 0; i < nr_args; i++) {
4469 const struct btf_type *arg_type;
4472 arg_type_id = args[i].type;
4473 arg_type = btf_type_by_id(btf, arg_type_id);
4475 btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
4480 if (args[i].name_off &&
4481 (!btf_name_offset_valid(btf, args[i].name_off) ||
4482 !btf_name_valid_identifier(btf, args[i].name_off))) {
4483 btf_verifier_log_type(env, t,
4484 "Invalid arg#%u", i + 1);
4489 if (btf_type_needs_resolve(arg_type) &&
4490 !env_type_is_resolved(env, arg_type_id)) {
4491 err = btf_resolve(env, arg_type, arg_type_id);
4496 if (!btf_type_id_size(btf, &arg_type_id, NULL)) {
4497 btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
4506 static int btf_func_check(struct btf_verifier_env *env,
4507 const struct btf_type *t)
4509 const struct btf_type *proto_type;
4510 const struct btf_param *args;
4511 const struct btf *btf;
4515 proto_type = btf_type_by_id(btf, t->type);
4517 if (!proto_type || !btf_type_is_func_proto(proto_type)) {
4518 btf_verifier_log_type(env, t, "Invalid type_id");
4522 args = (const struct btf_param *)(proto_type + 1);
4523 nr_args = btf_type_vlen(proto_type);
4524 for (i = 0; i < nr_args; i++) {
4525 if (!args[i].name_off && args[i].type) {
4526 btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
4534 static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = {
4535 [BTF_KIND_INT] = &int_ops,
4536 [BTF_KIND_PTR] = &ptr_ops,
4537 [BTF_KIND_ARRAY] = &array_ops,
4538 [BTF_KIND_STRUCT] = &struct_ops,
4539 [BTF_KIND_UNION] = &struct_ops,
4540 [BTF_KIND_ENUM] = &enum_ops,
4541 [BTF_KIND_FWD] = &fwd_ops,
4542 [BTF_KIND_TYPEDEF] = &modifier_ops,
4543 [BTF_KIND_VOLATILE] = &modifier_ops,
4544 [BTF_KIND_CONST] = &modifier_ops,
4545 [BTF_KIND_RESTRICT] = &modifier_ops,
4546 [BTF_KIND_FUNC] = &func_ops,
4547 [BTF_KIND_FUNC_PROTO] = &func_proto_ops,
4548 [BTF_KIND_VAR] = &var_ops,
4549 [BTF_KIND_DATASEC] = &datasec_ops,
4550 [BTF_KIND_FLOAT] = &float_ops,
4551 [BTF_KIND_DECL_TAG] = &decl_tag_ops,
4552 [BTF_KIND_TYPE_TAG] = &modifier_ops,
4553 [BTF_KIND_ENUM64] = &enum64_ops,
4556 static s32 btf_check_meta(struct btf_verifier_env *env,
4557 const struct btf_type *t,
4560 u32 saved_meta_left = meta_left;
4563 if (meta_left < sizeof(*t)) {
4564 btf_verifier_log(env, "[%u] meta_left:%u meta_needed:%zu",
4565 env->log_type_id, meta_left, sizeof(*t));
4568 meta_left -= sizeof(*t);
4570 if (t->info & ~BTF_INFO_MASK) {
4571 btf_verifier_log(env, "[%u] Invalid btf_info:%x",
4572 env->log_type_id, t->info);
4576 if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX ||
4577 BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) {
4578 btf_verifier_log(env, "[%u] Invalid kind:%u",
4579 env->log_type_id, BTF_INFO_KIND(t->info));
4583 if (!btf_name_offset_valid(env->btf, t->name_off)) {
4584 btf_verifier_log(env, "[%u] Invalid name_offset:%u",
4585 env->log_type_id, t->name_off);
4589 var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left);
4590 if (var_meta_size < 0)
4591 return var_meta_size;
4593 meta_left -= var_meta_size;
4595 return saved_meta_left - meta_left;
4598 static int btf_check_all_metas(struct btf_verifier_env *env)
4600 struct btf *btf = env->btf;
4601 struct btf_header *hdr;
4605 cur = btf->nohdr_data + hdr->type_off;
4606 end = cur + hdr->type_len;
4608 env->log_type_id = btf->base_btf ? btf->start_id : 1;
4610 struct btf_type *t = cur;
4613 meta_size = btf_check_meta(env, t, end - cur);
4617 btf_add_type(env, t);
4625 static bool btf_resolve_valid(struct btf_verifier_env *env,
4626 const struct btf_type *t,
4629 struct btf *btf = env->btf;
4631 if (!env_type_is_resolved(env, type_id))
4634 if (btf_type_is_struct(t) || btf_type_is_datasec(t))
4635 return !btf_resolved_type_id(btf, type_id) &&
4636 !btf_resolved_type_size(btf, type_id);
4638 if (btf_type_is_decl_tag(t) || btf_type_is_func(t))
4639 return btf_resolved_type_id(btf, type_id) &&
4640 !btf_resolved_type_size(btf, type_id);
4642 if (btf_type_is_modifier(t) || btf_type_is_ptr(t) ||
4643 btf_type_is_var(t)) {
4644 t = btf_type_id_resolve(btf, &type_id);
4646 !btf_type_is_modifier(t) &&
4647 !btf_type_is_var(t) &&
4648 !btf_type_is_datasec(t);
4651 if (btf_type_is_array(t)) {
4652 const struct btf_array *array = btf_type_array(t);
4653 const struct btf_type *elem_type;
4654 u32 elem_type_id = array->type;
4657 elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size);
4658 return elem_type && !btf_type_is_modifier(elem_type) &&
4659 (array->nelems * elem_size ==
4660 btf_resolved_type_size(btf, type_id));
4666 static int btf_resolve(struct btf_verifier_env *env,
4667 const struct btf_type *t, u32 type_id)
4669 u32 save_log_type_id = env->log_type_id;
4670 const struct resolve_vertex *v;
4673 env->resolve_mode = RESOLVE_TBD;
4674 env_stack_push(env, t, type_id);
4675 while (!err && (v = env_stack_peak(env))) {
4676 env->log_type_id = v->type_id;
4677 err = btf_type_ops(v->t)->resolve(env, v);
4680 env->log_type_id = type_id;
4681 if (err == -E2BIG) {
4682 btf_verifier_log_type(env, t,
4683 "Exceeded max resolving depth:%u",
4685 } else if (err == -EEXIST) {
4686 btf_verifier_log_type(env, t, "Loop detected");
4689 /* Final sanity check */
4690 if (!err && !btf_resolve_valid(env, t, type_id)) {
4691 btf_verifier_log_type(env, t, "Invalid resolve state");
4695 env->log_type_id = save_log_type_id;
4699 static int btf_check_all_types(struct btf_verifier_env *env)
4701 struct btf *btf = env->btf;
4702 const struct btf_type *t;
4706 err = env_resolve_init(env);
4711 for (i = btf->base_btf ? 0 : 1; i < btf->nr_types; i++) {
4712 type_id = btf->start_id + i;
4713 t = btf_type_by_id(btf, type_id);
4715 env->log_type_id = type_id;
4716 if (btf_type_needs_resolve(t) &&
4717 !env_type_is_resolved(env, type_id)) {
4718 err = btf_resolve(env, t, type_id);
4723 if (btf_type_is_func_proto(t)) {
4724 err = btf_func_proto_check(env, t);
4733 static int btf_parse_type_sec(struct btf_verifier_env *env)
4735 const struct btf_header *hdr = &env->btf->hdr;
4738 /* Type section must align to 4 bytes */
4739 if (hdr->type_off & (sizeof(u32) - 1)) {
4740 btf_verifier_log(env, "Unaligned type_off");
4744 if (!env->btf->base_btf && !hdr->type_len) {
4745 btf_verifier_log(env, "No type found");
4749 err = btf_check_all_metas(env);
4753 return btf_check_all_types(env);
4756 static int btf_parse_str_sec(struct btf_verifier_env *env)
4758 const struct btf_header *hdr;
4759 struct btf *btf = env->btf;
4760 const char *start, *end;
4763 start = btf->nohdr_data + hdr->str_off;
4764 end = start + hdr->str_len;
4766 if (end != btf->data + btf->data_size) {
4767 btf_verifier_log(env, "String section is not at the end");
4771 btf->strings = start;
4773 if (btf->base_btf && !hdr->str_len)
4775 if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET || end[-1]) {
4776 btf_verifier_log(env, "Invalid string section");
4779 if (!btf->base_btf && start[0]) {
4780 btf_verifier_log(env, "Invalid string section");
4787 static const size_t btf_sec_info_offset[] = {
4788 offsetof(struct btf_header, type_off),
4789 offsetof(struct btf_header, str_off),
4792 static int btf_sec_info_cmp(const void *a, const void *b)
4794 const struct btf_sec_info *x = a;
4795 const struct btf_sec_info *y = b;
4797 return (int)(x->off - y->off) ? : (int)(x->len - y->len);
4800 static int btf_check_sec_info(struct btf_verifier_env *env,
4803 struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)];
4804 u32 total, expected_total, i;
4805 const struct btf_header *hdr;
4806 const struct btf *btf;
4811 /* Populate the secs from hdr */
4812 for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++)
4813 secs[i] = *(struct btf_sec_info *)((void *)hdr +
4814 btf_sec_info_offset[i]);
4816 sort(secs, ARRAY_SIZE(btf_sec_info_offset),
4817 sizeof(struct btf_sec_info), btf_sec_info_cmp, NULL);
4819 /* Check for gaps and overlap among sections */
4821 expected_total = btf_data_size - hdr->hdr_len;
4822 for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) {
4823 if (expected_total < secs[i].off) {
4824 btf_verifier_log(env, "Invalid section offset");
4827 if (total < secs[i].off) {
4829 btf_verifier_log(env, "Unsupported section found");
4832 if (total > secs[i].off) {
4833 btf_verifier_log(env, "Section overlap found");
4836 if (expected_total - total < secs[i].len) {
4837 btf_verifier_log(env,
4838 "Total section length too long");
4841 total += secs[i].len;
4844 /* There is data other than hdr and known sections */
4845 if (expected_total != total) {
4846 btf_verifier_log(env, "Unsupported section found");
4853 static int btf_parse_hdr(struct btf_verifier_env *env)
4855 u32 hdr_len, hdr_copy, btf_data_size;
4856 const struct btf_header *hdr;
4861 btf_data_size = btf->data_size;
4863 if (btf_data_size < offsetofend(struct btf_header, hdr_len)) {
4864 btf_verifier_log(env, "hdr_len not found");
4869 hdr_len = hdr->hdr_len;
4870 if (btf_data_size < hdr_len) {
4871 btf_verifier_log(env, "btf_header not found");
4875 /* Ensure the unsupported header fields are zero */
4876 if (hdr_len > sizeof(btf->hdr)) {
4877 u8 *expected_zero = btf->data + sizeof(btf->hdr);
4878 u8 *end = btf->data + hdr_len;
4880 for (; expected_zero < end; expected_zero++) {
4881 if (*expected_zero) {
4882 btf_verifier_log(env, "Unsupported btf_header");
4888 hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr));
4889 memcpy(&btf->hdr, btf->data, hdr_copy);
4893 btf_verifier_log_hdr(env, btf_data_size);
4895 if (hdr->magic != BTF_MAGIC) {
4896 btf_verifier_log(env, "Invalid magic");
4900 if (hdr->version != BTF_VERSION) {
4901 btf_verifier_log(env, "Unsupported version");
4906 btf_verifier_log(env, "Unsupported flags");
4910 if (!btf->base_btf && btf_data_size == hdr->hdr_len) {
4911 btf_verifier_log(env, "No data");
4915 err = btf_check_sec_info(env, btf_data_size);
4922 static int btf_check_type_tags(struct btf_verifier_env *env,
4923 struct btf *btf, int start_id)
4925 int i, n, good_id = start_id - 1;
4928 n = btf_nr_types(btf);
4929 for (i = start_id; i < n; i++) {
4930 const struct btf_type *t;
4931 int chain_limit = 32;
4934 t = btf_type_by_id(btf, i);
4937 if (!btf_type_is_modifier(t))
4942 in_tags = btf_type_is_type_tag(t);
4943 while (btf_type_is_modifier(t)) {
4944 if (!chain_limit--) {
4945 btf_verifier_log(env, "Max chain length or cycle detected");
4948 if (btf_type_is_type_tag(t)) {
4950 btf_verifier_log(env, "Type tags don't precede modifiers");
4953 } else if (in_tags) {
4956 if (cur_id <= good_id)
4958 /* Move to next type */
4960 t = btf_type_by_id(btf, cur_id);
4969 static struct btf *btf_parse(bpfptr_t btf_data, u32 btf_data_size,
4970 u32 log_level, char __user *log_ubuf, u32 log_size)
4972 struct btf_verifier_env *env = NULL;
4973 struct bpf_verifier_log *log;
4974 struct btf *btf = NULL;
4978 if (btf_data_size > BTF_MAX_SIZE)
4979 return ERR_PTR(-E2BIG);
4981 env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
4983 return ERR_PTR(-ENOMEM);
4986 if (log_level || log_ubuf || log_size) {
4987 /* user requested verbose verifier output
4988 * and supplied buffer to store the verification trace
4990 log->level = log_level;
4991 log->ubuf = log_ubuf;
4992 log->len_total = log_size;
4994 /* log attributes have to be sane */
4995 if (!bpf_verifier_log_attr_valid(log)) {
5001 btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN);
5008 data = kvmalloc(btf_data_size, GFP_KERNEL | __GFP_NOWARN);
5015 btf->data_size = btf_data_size;
5017 if (copy_from_bpfptr(data, btf_data, btf_data_size)) {
5022 err = btf_parse_hdr(env);
5026 btf->nohdr_data = btf->data + btf->hdr.hdr_len;
5028 err = btf_parse_str_sec(env);
5032 err = btf_parse_type_sec(env);
5036 err = btf_check_type_tags(env, btf, 1);
5040 if (log->level && bpf_verifier_log_full(log)) {
5045 btf_verifier_env_free(env);
5046 refcount_set(&btf->refcnt, 1);
5050 btf_verifier_env_free(env);
5053 return ERR_PTR(err);
5056 extern char __weak __start_BTF[];
5057 extern char __weak __stop_BTF[];
5058 extern struct btf *btf_vmlinux;
5060 #define BPF_MAP_TYPE(_id, _ops)
5061 #define BPF_LINK_TYPE(_id, _name)
5063 struct bpf_ctx_convert {
5064 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
5065 prog_ctx_type _id##_prog; \
5066 kern_ctx_type _id##_kern;
5067 #include <linux/bpf_types.h>
5068 #undef BPF_PROG_TYPE
5070 /* 't' is written once under lock. Read many times. */
5071 const struct btf_type *t;
5074 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
5076 #include <linux/bpf_types.h>
5077 #undef BPF_PROG_TYPE
5078 __ctx_convert_unused, /* to avoid empty enum in extreme .config */
5080 static u8 bpf_ctx_convert_map[] = {
5081 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
5082 [_id] = __ctx_convert##_id,
5083 #include <linux/bpf_types.h>
5084 #undef BPF_PROG_TYPE
5085 0, /* avoid empty array */
5088 #undef BPF_LINK_TYPE
5090 static const struct btf_member *
5091 btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
5092 const struct btf_type *t, enum bpf_prog_type prog_type,
5095 const struct btf_type *conv_struct;
5096 const struct btf_type *ctx_struct;
5097 const struct btf_member *ctx_type;
5098 const char *tname, *ctx_tname;
5100 conv_struct = bpf_ctx_convert.t;
5102 bpf_log(log, "btf_vmlinux is malformed\n");
5105 t = btf_type_by_id(btf, t->type);
5106 while (btf_type_is_modifier(t))
5107 t = btf_type_by_id(btf, t->type);
5108 if (!btf_type_is_struct(t)) {
5109 /* Only pointer to struct is supported for now.
5110 * That means that BPF_PROG_TYPE_TRACEPOINT with BTF
5111 * is not supported yet.
5112 * BPF_PROG_TYPE_RAW_TRACEPOINT is fine.
5116 tname = btf_name_by_offset(btf, t->name_off);
5118 bpf_log(log, "arg#%d struct doesn't have a name\n", arg);
5121 /* prog_type is valid bpf program type. No need for bounds check. */
5122 ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2;
5123 /* ctx_struct is a pointer to prog_ctx_type in vmlinux.
5124 * Like 'struct __sk_buff'
5126 ctx_struct = btf_type_by_id(btf_vmlinux, ctx_type->type);
5128 /* should not happen */
5130 ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_struct->name_off);
5132 /* should not happen */
5133 bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n");
5136 /* only compare that prog's ctx type name is the same as
5137 * kernel expects. No need to compare field by field.
5138 * It's ok for bpf prog to do:
5139 * struct __sk_buff {};
5140 * int socket_filter_bpf_prog(struct __sk_buff *skb)
5141 * { // no fields of skb are ever used }
5143 if (strcmp(ctx_tname, tname))
5148 static int btf_translate_to_vmlinux(struct bpf_verifier_log *log,
5150 const struct btf_type *t,
5151 enum bpf_prog_type prog_type,
5154 const struct btf_member *prog_ctx_type, *kern_ctx_type;
5156 prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type, arg);
5159 kern_ctx_type = prog_ctx_type + 1;
5160 return kern_ctx_type->type;
5163 BTF_ID_LIST(bpf_ctx_convert_btf_id)
5164 BTF_ID(struct, bpf_ctx_convert)
5166 struct btf *btf_parse_vmlinux(void)
5168 struct btf_verifier_env *env = NULL;
5169 struct bpf_verifier_log *log;
5170 struct btf *btf = NULL;
5173 env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
5175 return ERR_PTR(-ENOMEM);
5178 log->level = BPF_LOG_KERNEL;
5180 btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN);
5187 btf->data = __start_BTF;
5188 btf->data_size = __stop_BTF - __start_BTF;
5189 btf->kernel_btf = true;
5190 snprintf(btf->name, sizeof(btf->name), "vmlinux");
5192 err = btf_parse_hdr(env);
5196 btf->nohdr_data = btf->data + btf->hdr.hdr_len;
5198 err = btf_parse_str_sec(env);
5202 err = btf_check_all_metas(env);
5206 err = btf_check_type_tags(env, btf, 1);
5210 /* btf_parse_vmlinux() runs under bpf_verifier_lock */
5211 bpf_ctx_convert.t = btf_type_by_id(btf, bpf_ctx_convert_btf_id[0]);
5213 bpf_struct_ops_init(btf, log);
5215 refcount_set(&btf->refcnt, 1);
5217 err = btf_alloc_id(btf);
5221 btf_verifier_env_free(env);
5225 btf_verifier_env_free(env);
5230 return ERR_PTR(err);
5233 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
5235 static struct btf *btf_parse_module(const char *module_name, const void *data, unsigned int data_size)
5237 struct btf_verifier_env *env = NULL;
5238 struct bpf_verifier_log *log;
5239 struct btf *btf = NULL, *base_btf;
5242 base_btf = bpf_get_btf_vmlinux();
5243 if (IS_ERR(base_btf))
5246 return ERR_PTR(-EINVAL);
5248 env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
5250 return ERR_PTR(-ENOMEM);
5253 log->level = BPF_LOG_KERNEL;
5255 btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN);
5262 btf->base_btf = base_btf;
5263 btf->start_id = base_btf->nr_types;
5264 btf->start_str_off = base_btf->hdr.str_len;
5265 btf->kernel_btf = true;
5266 snprintf(btf->name, sizeof(btf->name), "%s", module_name);
5268 btf->data = kvmalloc(data_size, GFP_KERNEL | __GFP_NOWARN);
5273 memcpy(btf->data, data, data_size);
5274 btf->data_size = data_size;
5276 err = btf_parse_hdr(env);
5280 btf->nohdr_data = btf->data + btf->hdr.hdr_len;
5282 err = btf_parse_str_sec(env);
5286 err = btf_check_all_metas(env);
5290 err = btf_check_type_tags(env, btf, btf_nr_types(base_btf));
5294 btf_verifier_env_free(env);
5295 refcount_set(&btf->refcnt, 1);
5299 btf_verifier_env_free(env);
5305 return ERR_PTR(err);
5308 #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */
5310 struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog)
5312 struct bpf_prog *tgt_prog = prog->aux->dst_prog;
5315 return tgt_prog->aux->btf;
5317 return prog->aux->attach_btf;
5320 static bool is_int_ptr(struct btf *btf, const struct btf_type *t)
5322 /* t comes in already as a pointer */
5323 t = btf_type_by_id(btf, t->type);
5326 if (BTF_INFO_KIND(t->info) == BTF_KIND_CONST)
5327 t = btf_type_by_id(btf, t->type);
5329 return btf_type_is_int(t);
5332 bool btf_ctx_access(int off, int size, enum bpf_access_type type,
5333 const struct bpf_prog *prog,
5334 struct bpf_insn_access_aux *info)
5336 const struct btf_type *t = prog->aux->attach_func_proto;
5337 struct bpf_prog *tgt_prog = prog->aux->dst_prog;
5338 struct btf *btf = bpf_prog_get_target_btf(prog);
5339 const char *tname = prog->aux->attach_func_name;
5340 struct bpf_verifier_log *log = info->log;
5341 const struct btf_param *args;
5342 const char *tag_value;
5347 bpf_log(log, "func '%s' offset %d is not multiple of 8\n",
5352 args = (const struct btf_param *)(t + 1);
5353 /* if (t == NULL) Fall back to default BPF prog with
5354 * MAX_BPF_FUNC_REG_ARGS u64 arguments.
5356 nr_args = t ? btf_type_vlen(t) : MAX_BPF_FUNC_REG_ARGS;
5357 if (prog->aux->attach_btf_trace) {
5358 /* skip first 'void *__data' argument in btf_trace_##name typedef */
5363 if (arg > nr_args) {
5364 bpf_log(log, "func '%s' doesn't have %d-th argument\n",
5369 if (arg == nr_args) {
5370 switch (prog->expected_attach_type) {
5371 case BPF_LSM_CGROUP:
5373 case BPF_TRACE_FEXIT:
5374 /* When LSM programs are attached to void LSM hooks
5375 * they use FEXIT trampolines and when attached to
5376 * int LSM hooks, they use MODIFY_RETURN trampolines.
5378 * While the LSM programs are BPF_MODIFY_RETURN-like
5381 * if (ret_type != 'int')
5384 * is _not_ done here. This is still safe as LSM hooks
5385 * have only void and int return types.
5389 t = btf_type_by_id(btf, t->type);
5391 case BPF_MODIFY_RETURN:
5392 /* For now the BPF_MODIFY_RETURN can only be attached to
5393 * functions that return an int.
5398 t = btf_type_skip_modifiers(btf, t->type, NULL);
5399 if (!btf_type_is_small_int(t)) {
5401 "ret type %s not allowed for fmod_ret\n",
5402 btf_kind_str[BTF_INFO_KIND(t->info)]);
5407 bpf_log(log, "func '%s' doesn't have %d-th argument\n",
5413 /* Default prog with MAX_BPF_FUNC_REG_ARGS args */
5415 t = btf_type_by_id(btf, args[arg].type);
5418 /* skip modifiers */
5419 while (btf_type_is_modifier(t))
5420 t = btf_type_by_id(btf, t->type);
5421 if (btf_type_is_small_int(t) || btf_is_any_enum(t))
5422 /* accessing a scalar */
5424 if (!btf_type_is_ptr(t)) {
5426 "func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n",
5428 __btf_name_by_offset(btf, t->name_off),
5429 btf_kind_str[BTF_INFO_KIND(t->info)]);
5433 /* check for PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL */
5434 for (i = 0; i < prog->aux->ctx_arg_info_size; i++) {
5435 const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i];
5438 type = base_type(ctx_arg_info->reg_type);
5439 flag = type_flag(ctx_arg_info->reg_type);
5440 if (ctx_arg_info->offset == off && type == PTR_TO_BUF &&
5441 (flag & PTR_MAYBE_NULL)) {
5442 info->reg_type = ctx_arg_info->reg_type;
5448 /* This is a pointer to void.
5449 * It is the same as scalar from the verifier safety pov.
5450 * No further pointer walking is allowed.
5454 if (is_int_ptr(btf, t))
5457 /* this is a pointer to another type */
5458 for (i = 0; i < prog->aux->ctx_arg_info_size; i++) {
5459 const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i];
5461 if (ctx_arg_info->offset == off) {
5462 if (!ctx_arg_info->btf_id) {
5463 bpf_log(log,"invalid btf_id for context argument offset %u\n", off);
5467 info->reg_type = ctx_arg_info->reg_type;
5468 info->btf = btf_vmlinux;
5469 info->btf_id = ctx_arg_info->btf_id;
5474 info->reg_type = PTR_TO_BTF_ID;
5476 enum bpf_prog_type tgt_type;
5478 if (tgt_prog->type == BPF_PROG_TYPE_EXT)
5479 tgt_type = tgt_prog->aux->saved_dst_prog_type;
5481 tgt_type = tgt_prog->type;
5483 ret = btf_translate_to_vmlinux(log, btf, t, tgt_type, arg);
5485 info->btf = btf_vmlinux;
5494 info->btf_id = t->type;
5495 t = btf_type_by_id(btf, t->type);
5497 if (btf_type_is_type_tag(t)) {
5498 tag_value = __btf_name_by_offset(btf, t->name_off);
5499 if (strcmp(tag_value, "user") == 0)
5500 info->reg_type |= MEM_USER;
5501 if (strcmp(tag_value, "percpu") == 0)
5502 info->reg_type |= MEM_PERCPU;
5505 /* skip modifiers */
5506 while (btf_type_is_modifier(t)) {
5507 info->btf_id = t->type;
5508 t = btf_type_by_id(btf, t->type);
5510 if (!btf_type_is_struct(t)) {
5512 "func '%s' arg%d type %s is not a struct\n",
5513 tname, arg, btf_kind_str[BTF_INFO_KIND(t->info)]);
5516 bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n",
5517 tname, arg, info->btf_id, btf_kind_str[BTF_INFO_KIND(t->info)],
5518 __btf_name_by_offset(btf, t->name_off));
5522 enum bpf_struct_walk_result {
5529 static int btf_struct_walk(struct bpf_verifier_log *log, const struct btf *btf,
5530 const struct btf_type *t, int off, int size,
5531 u32 *next_btf_id, enum bpf_type_flag *flag)
5533 u32 i, moff, mtrue_end, msize = 0, total_nelems = 0;
5534 const struct btf_type *mtype, *elem_type = NULL;
5535 const struct btf_member *member;
5536 const char *tname, *mname, *tag_value;
5537 u32 vlen, elem_id, mid;
5540 tname = __btf_name_by_offset(btf, t->name_off);
5541 if (!btf_type_is_struct(t)) {
5542 bpf_log(log, "Type '%s' is not a struct\n", tname);
5546 vlen = btf_type_vlen(t);
5547 if (off + size > t->size) {
5548 /* If the last element is a variable size array, we may
5549 * need to relax the rule.
5551 struct btf_array *array_elem;
5556 member = btf_type_member(t) + vlen - 1;
5557 mtype = btf_type_skip_modifiers(btf, member->type,
5559 if (!btf_type_is_array(mtype))
5562 array_elem = (struct btf_array *)(mtype + 1);
5563 if (array_elem->nelems != 0)
5566 moff = __btf_member_bit_offset(t, member) / 8;
5570 /* Only allow structure for now, can be relaxed for
5571 * other types later.
5573 t = btf_type_skip_modifiers(btf, array_elem->type,
5575 if (!btf_type_is_struct(t))
5578 off = (off - moff) % t->size;
5582 bpf_log(log, "access beyond struct %s at off %u size %u\n",
5587 for_each_member(i, t, member) {
5588 /* offset of the field in bytes */
5589 moff = __btf_member_bit_offset(t, member) / 8;
5590 if (off + size <= moff)
5591 /* won't find anything, field is already too far */
5594 if (__btf_member_bitfield_size(t, member)) {
5595 u32 end_bit = __btf_member_bit_offset(t, member) +
5596 __btf_member_bitfield_size(t, member);
5598 /* off <= moff instead of off == moff because clang
5599 * does not generate a BTF member for anonymous
5600 * bitfield like the ":16" here:
5607 BITS_ROUNDUP_BYTES(end_bit) <= off + size)
5610 /* off may be accessing a following member
5614 * Doing partial access at either end of this
5615 * bitfield. Continue on this case also to
5616 * treat it as not accessing this bitfield
5617 * and eventually error out as field not
5618 * found to keep it simple.
5619 * It could be relaxed if there was a legit
5620 * partial access case later.
5625 /* In case of "off" is pointing to holes of a struct */
5629 /* type of the field */
5631 mtype = btf_type_by_id(btf, member->type);
5632 mname = __btf_name_by_offset(btf, member->name_off);
5634 mtype = __btf_resolve_size(btf, mtype, &msize,
5635 &elem_type, &elem_id, &total_nelems,
5637 if (IS_ERR(mtype)) {
5638 bpf_log(log, "field %s doesn't have size\n", mname);
5642 mtrue_end = moff + msize;
5643 if (off >= mtrue_end)
5644 /* no overlap with member, keep iterating */
5647 if (btf_type_is_array(mtype)) {
5650 /* __btf_resolve_size() above helps to
5651 * linearize a multi-dimensional array.
5653 * The logic here is treating an array
5654 * in a struct as the following way:
5657 * struct inner array[2][2];
5663 * struct inner array_elem0;
5664 * struct inner array_elem1;
5665 * struct inner array_elem2;
5666 * struct inner array_elem3;
5669 * When accessing outer->array[1][0], it moves
5670 * moff to "array_elem2", set mtype to
5671 * "struct inner", and msize also becomes
5672 * sizeof(struct inner). Then most of the
5673 * remaining logic will fall through without
5674 * caring the current member is an array or
5677 * Unlike mtype/msize/moff, mtrue_end does not
5678 * change. The naming difference ("_true") tells
5679 * that it is not always corresponding to
5680 * the current mtype/msize/moff.
5681 * It is the true end of the current
5682 * member (i.e. array in this case). That
5683 * will allow an int array to be accessed like
5685 * i.e. allow access beyond the size of
5686 * the array's element as long as it is
5687 * within the mtrue_end boundary.
5690 /* skip empty array */
5691 if (moff == mtrue_end)
5694 msize /= total_nelems;
5695 elem_idx = (off - moff) / msize;
5696 moff += elem_idx * msize;
5701 /* the 'off' we're looking for is either equal to start
5702 * of this field or inside of this struct
5704 if (btf_type_is_struct(mtype)) {
5705 /* our field must be inside that union or struct */
5708 /* return if the offset matches the member offset */
5714 /* adjust offset we're looking for */
5719 if (btf_type_is_ptr(mtype)) {
5720 const struct btf_type *stype, *t;
5721 enum bpf_type_flag tmp_flag = 0;
5724 if (msize != size || off != moff) {
5726 "cannot access ptr member %s with moff %u in struct %s with off %u size %u\n",
5727 mname, moff, tname, off, size);
5731 /* check type tag */
5732 t = btf_type_by_id(btf, mtype->type);
5733 if (btf_type_is_type_tag(t)) {
5734 tag_value = __btf_name_by_offset(btf, t->name_off);
5735 /* check __user tag */
5736 if (strcmp(tag_value, "user") == 0)
5737 tmp_flag = MEM_USER;
5738 /* check __percpu tag */
5739 if (strcmp(tag_value, "percpu") == 0)
5740 tmp_flag = MEM_PERCPU;
5743 stype = btf_type_skip_modifiers(btf, mtype->type, &id);
5744 if (btf_type_is_struct(stype)) {
5751 /* Allow more flexible access within an int as long as
5752 * it is within mtrue_end.
5753 * Since mtrue_end could be the end of an array,
5754 * that also allows using an array of int as a scratch
5755 * space. e.g. skb->cb[].
5757 if (off + size > mtrue_end) {
5759 "access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n",
5760 mname, mtrue_end, tname, off, size);
5766 bpf_log(log, "struct %s doesn't have field at offset %d\n", tname, off);
5770 int btf_struct_access(struct bpf_verifier_log *log, const struct btf *btf,
5771 const struct btf_type *t, int off, int size,
5772 enum bpf_access_type atype __maybe_unused,
5773 u32 *next_btf_id, enum bpf_type_flag *flag)
5775 enum bpf_type_flag tmp_flag = 0;
5780 err = btf_struct_walk(log, btf, t, off, size, &id, &tmp_flag);
5784 /* If we found the pointer or scalar on t+off,
5789 return PTR_TO_BTF_ID;
5791 return SCALAR_VALUE;
5793 /* We found nested struct, so continue the search
5794 * by diving in it. At this point the offset is
5795 * aligned with the new type, so set it to 0.
5797 t = btf_type_by_id(btf, id);
5801 /* It's either error or unknown return value..
5804 if (WARN_ONCE(err > 0, "unknown btf_struct_walk return value"))
5813 /* Check that two BTF types, each specified as an BTF object + id, are exactly
5814 * the same. Trivial ID check is not enough due to module BTFs, because we can
5815 * end up with two different module BTFs, but IDs point to the common type in
5818 static bool btf_types_are_same(const struct btf *btf1, u32 id1,
5819 const struct btf *btf2, u32 id2)
5825 return btf_type_by_id(btf1, id1) == btf_type_by_id(btf2, id2);
5828 bool btf_struct_ids_match(struct bpf_verifier_log *log,
5829 const struct btf *btf, u32 id, int off,
5830 const struct btf *need_btf, u32 need_type_id,
5833 const struct btf_type *type;
5834 enum bpf_type_flag flag;
5837 /* Are we already done? */
5838 if (off == 0 && btf_types_are_same(btf, id, need_btf, need_type_id))
5840 /* In case of strict type match, we do not walk struct, the top level
5841 * type match must succeed. When strict is true, off should have already
5847 type = btf_type_by_id(btf, id);
5850 err = btf_struct_walk(log, btf, type, off, 1, &id, &flag);
5851 if (err != WALK_STRUCT)
5854 /* We found nested struct object. If it matches
5855 * the requested ID, we're done. Otherwise let's
5856 * continue the search with offset 0 in the new
5859 if (!btf_types_are_same(btf, id, need_btf, need_type_id)) {
5867 static int __get_type_size(struct btf *btf, u32 btf_id,
5868 const struct btf_type **bad_type)
5870 const struct btf_type *t;
5875 t = btf_type_by_id(btf, btf_id);
5876 while (t && btf_type_is_modifier(t))
5877 t = btf_type_by_id(btf, t->type);
5879 *bad_type = btf_type_by_id(btf, 0);
5882 if (btf_type_is_ptr(t))
5883 /* kernel size of pointer. Not BPF's size of pointer*/
5884 return sizeof(void *);
5885 if (btf_type_is_int(t) || btf_is_any_enum(t))
5891 int btf_distill_func_proto(struct bpf_verifier_log *log,
5893 const struct btf_type *func,
5895 struct btf_func_model *m)
5897 const struct btf_param *args;
5898 const struct btf_type *t;
5903 /* BTF function prototype doesn't match the verifier types.
5904 * Fall back to MAX_BPF_FUNC_REG_ARGS u64 args.
5906 for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++)
5909 m->nr_args = MAX_BPF_FUNC_REG_ARGS;
5912 args = (const struct btf_param *)(func + 1);
5913 nargs = btf_type_vlen(func);
5914 if (nargs > MAX_BPF_FUNC_ARGS) {
5916 "The function %s has %d arguments. Too many.\n",
5920 ret = __get_type_size(btf, func->type, &t);
5923 "The function %s return type %s is unsupported.\n",
5924 tname, btf_kind_str[BTF_INFO_KIND(t->info)]);
5929 for (i = 0; i < nargs; i++) {
5930 if (i == nargs - 1 && args[i].type == 0) {
5932 "The function %s with variable args is unsupported.\n",
5936 ret = __get_type_size(btf, args[i].type, &t);
5939 "The function %s arg%d type %s is unsupported.\n",
5940 tname, i, btf_kind_str[BTF_INFO_KIND(t->info)]);
5945 "The function %s has malformed void argument.\n",
5949 m->arg_size[i] = ret;
5955 /* Compare BTFs of two functions assuming only scalars and pointers to context.
5956 * t1 points to BTF_KIND_FUNC in btf1
5957 * t2 points to BTF_KIND_FUNC in btf2
5959 * EINVAL - function prototype mismatch
5960 * EFAULT - verifier bug
5961 * 0 - 99% match. The last 1% is validated by the verifier.
5963 static int btf_check_func_type_match(struct bpf_verifier_log *log,
5964 struct btf *btf1, const struct btf_type *t1,
5965 struct btf *btf2, const struct btf_type *t2)
5967 const struct btf_param *args1, *args2;
5968 const char *fn1, *fn2, *s1, *s2;
5969 u32 nargs1, nargs2, i;
5971 fn1 = btf_name_by_offset(btf1, t1->name_off);
5972 fn2 = btf_name_by_offset(btf2, t2->name_off);
5974 if (btf_func_linkage(t1) != BTF_FUNC_GLOBAL) {
5975 bpf_log(log, "%s() is not a global function\n", fn1);
5978 if (btf_func_linkage(t2) != BTF_FUNC_GLOBAL) {
5979 bpf_log(log, "%s() is not a global function\n", fn2);
5983 t1 = btf_type_by_id(btf1, t1->type);
5984 if (!t1 || !btf_type_is_func_proto(t1))
5986 t2 = btf_type_by_id(btf2, t2->type);
5987 if (!t2 || !btf_type_is_func_proto(t2))
5990 args1 = (const struct btf_param *)(t1 + 1);
5991 nargs1 = btf_type_vlen(t1);
5992 args2 = (const struct btf_param *)(t2 + 1);
5993 nargs2 = btf_type_vlen(t2);
5995 if (nargs1 != nargs2) {
5996 bpf_log(log, "%s() has %d args while %s() has %d args\n",
5997 fn1, nargs1, fn2, nargs2);
6001 t1 = btf_type_skip_modifiers(btf1, t1->type, NULL);
6002 t2 = btf_type_skip_modifiers(btf2, t2->type, NULL);
6003 if (t1->info != t2->info) {
6005 "Return type %s of %s() doesn't match type %s of %s()\n",
6006 btf_type_str(t1), fn1,
6007 btf_type_str(t2), fn2);
6011 for (i = 0; i < nargs1; i++) {
6012 t1 = btf_type_skip_modifiers(btf1, args1[i].type, NULL);
6013 t2 = btf_type_skip_modifiers(btf2, args2[i].type, NULL);
6015 if (t1->info != t2->info) {
6016 bpf_log(log, "arg%d in %s() is %s while %s() has %s\n",
6017 i, fn1, btf_type_str(t1),
6018 fn2, btf_type_str(t2));
6021 if (btf_type_has_size(t1) && t1->size != t2->size) {
6023 "arg%d in %s() has size %d while %s() has %d\n",
6029 /* global functions are validated with scalars and pointers
6030 * to context only. And only global functions can be replaced.
6031 * Hence type check only those types.
6033 if (btf_type_is_int(t1) || btf_is_any_enum(t1))
6035 if (!btf_type_is_ptr(t1)) {
6037 "arg%d in %s() has unrecognized type\n",
6041 t1 = btf_type_skip_modifiers(btf1, t1->type, NULL);
6042 t2 = btf_type_skip_modifiers(btf2, t2->type, NULL);
6043 if (!btf_type_is_struct(t1)) {
6045 "arg%d in %s() is not a pointer to context\n",
6049 if (!btf_type_is_struct(t2)) {
6051 "arg%d in %s() is not a pointer to context\n",
6055 /* This is an optional check to make program writing easier.
6056 * Compare names of structs and report an error to the user.
6057 * btf_prepare_func_args() already checked that t2 struct
6058 * is a context type. btf_prepare_func_args() will check
6059 * later that t1 struct is a context type as well.
6061 s1 = btf_name_by_offset(btf1, t1->name_off);
6062 s2 = btf_name_by_offset(btf2, t2->name_off);
6063 if (strcmp(s1, s2)) {
6065 "arg%d %s(struct %s *) doesn't match %s(struct %s *)\n",
6066 i, fn1, s1, fn2, s2);
6073 /* Compare BTFs of given program with BTF of target program */
6074 int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog,
6075 struct btf *btf2, const struct btf_type *t2)
6077 struct btf *btf1 = prog->aux->btf;
6078 const struct btf_type *t1;
6081 if (!prog->aux->func_info) {
6082 bpf_log(log, "Program extension requires BTF\n");
6086 btf_id = prog->aux->func_info[0].type_id;
6090 t1 = btf_type_by_id(btf1, btf_id);
6091 if (!t1 || !btf_type_is_func(t1))
6094 return btf_check_func_type_match(log, btf1, t1, btf2, t2);
6097 static u32 *reg2btf_ids[__BPF_REG_TYPE_MAX] = {
6099 [PTR_TO_SOCKET] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK],
6100 [PTR_TO_SOCK_COMMON] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON],
6101 [PTR_TO_TCP_SOCK] = &btf_sock_ids[BTF_SOCK_TYPE_TCP],
6105 /* Returns true if struct is composed of scalars, 4 levels of nesting allowed */
6106 static bool __btf_type_is_scalar_struct(struct bpf_verifier_log *log,
6107 const struct btf *btf,
6108 const struct btf_type *t, int rec)
6110 const struct btf_type *member_type;
6111 const struct btf_member *member;
6114 if (!btf_type_is_struct(t))
6117 for_each_member(i, t, member) {
6118 const struct btf_array *array;
6120 member_type = btf_type_skip_modifiers(btf, member->type, NULL);
6121 if (btf_type_is_struct(member_type)) {
6123 bpf_log(log, "max struct nesting depth exceeded\n");
6126 if (!__btf_type_is_scalar_struct(log, btf, member_type, rec + 1))
6130 if (btf_type_is_array(member_type)) {
6131 array = btf_type_array(member_type);
6134 member_type = btf_type_skip_modifiers(btf, array->type, NULL);
6135 if (!btf_type_is_scalar(member_type))
6139 if (!btf_type_is_scalar(member_type))
6145 static bool is_kfunc_arg_mem_size(const struct btf *btf,
6146 const struct btf_param *arg,
6147 const struct bpf_reg_state *reg)
6149 int len, sfx_len = sizeof("__sz") - 1;
6150 const struct btf_type *t;
6151 const char *param_name;
6153 t = btf_type_skip_modifiers(btf, arg->type, NULL);
6154 if (!btf_type_is_scalar(t) || reg->type != SCALAR_VALUE)
6157 /* In the future, this can be ported to use BTF tagging */
6158 param_name = btf_name_by_offset(btf, arg->name_off);
6159 if (str_is_empty(param_name))
6161 len = strlen(param_name);
6164 param_name += len - sfx_len;
6165 if (strncmp(param_name, "__sz", sfx_len))
6171 static int btf_check_func_arg_match(struct bpf_verifier_env *env,
6172 const struct btf *btf, u32 func_id,
6173 struct bpf_reg_state *regs,
6176 enum bpf_prog_type prog_type = resolve_prog_type(env->prog);
6177 struct bpf_verifier_log *log = &env->log;
6178 u32 i, nargs, ref_id, ref_obj_id = 0;
6179 bool is_kfunc = btf_is_kernel(btf);
6180 bool rel = false, kptr_get = false;
6181 const char *func_name, *ref_tname;
6182 const struct btf_type *t, *ref_t;
6183 const struct btf_param *args;
6184 int ref_regno = 0, ret;
6186 t = btf_type_by_id(btf, func_id);
6187 if (!t || !btf_type_is_func(t)) {
6188 /* These checks were already done by the verifier while loading
6189 * struct bpf_func_info or in add_kfunc_call().
6191 bpf_log(log, "BTF of func_id %u doesn't point to KIND_FUNC\n",
6195 func_name = btf_name_by_offset(btf, t->name_off);
6197 t = btf_type_by_id(btf, t->type);
6198 if (!t || !btf_type_is_func_proto(t)) {
6199 bpf_log(log, "Invalid BTF of func %s\n", func_name);
6202 args = (const struct btf_param *)(t + 1);
6203 nargs = btf_type_vlen(t);
6204 if (nargs > MAX_BPF_FUNC_REG_ARGS) {
6205 bpf_log(log, "Function %s has %d > %d args\n", func_name, nargs,
6206 MAX_BPF_FUNC_REG_ARGS);
6211 /* Only kfunc can be release func */
6212 rel = btf_kfunc_id_set_contains(btf, resolve_prog_type(env->prog),
6213 BTF_KFUNC_TYPE_RELEASE, func_id);
6214 kptr_get = btf_kfunc_id_set_contains(btf, resolve_prog_type(env->prog),
6215 BTF_KFUNC_TYPE_KPTR_ACQUIRE, func_id);
6218 /* check that BTF function arguments match actual types that the
6221 for (i = 0; i < nargs; i++) {
6222 enum bpf_arg_type arg_type = ARG_DONTCARE;
6224 struct bpf_reg_state *reg = ®s[regno];
6226 t = btf_type_skip_modifiers(btf, args[i].type, NULL);
6227 if (btf_type_is_scalar(t)) {
6228 if (reg->type == SCALAR_VALUE)
6230 bpf_log(log, "R%d is not a scalar\n", regno);
6234 if (!btf_type_is_ptr(t)) {
6235 bpf_log(log, "Unrecognized arg#%d type %s\n",
6236 i, btf_type_str(t));
6240 ref_t = btf_type_skip_modifiers(btf, t->type, &ref_id);
6241 ref_tname = btf_name_by_offset(btf, ref_t->name_off);
6243 if (rel && reg->ref_obj_id)
6244 arg_type |= OBJ_RELEASE;
6245 ret = check_func_arg_reg_off(env, reg, regno, arg_type);
6249 /* kptr_get is only true for kfunc */
6250 if (i == 0 && kptr_get) {
6251 struct bpf_map_value_off_desc *off_desc;
6253 if (reg->type != PTR_TO_MAP_VALUE) {
6254 bpf_log(log, "arg#0 expected pointer to map value\n");
6258 /* check_func_arg_reg_off allows var_off for
6259 * PTR_TO_MAP_VALUE, but we need fixed offset to find
6262 if (!tnum_is_const(reg->var_off)) {
6263 bpf_log(log, "arg#0 must have constant offset\n");
6267 off_desc = bpf_map_kptr_off_contains(reg->map_ptr, reg->off + reg->var_off.value);
6268 if (!off_desc || off_desc->type != BPF_KPTR_REF) {
6269 bpf_log(log, "arg#0 no referenced kptr at map value offset=%llu\n",
6270 reg->off + reg->var_off.value);
6274 if (!btf_type_is_ptr(ref_t)) {
6275 bpf_log(log, "arg#0 BTF type must be a double pointer\n");
6279 ref_t = btf_type_skip_modifiers(btf, ref_t->type, &ref_id);
6280 ref_tname = btf_name_by_offset(btf, ref_t->name_off);
6282 if (!btf_type_is_struct(ref_t)) {
6283 bpf_log(log, "kernel function %s args#%d pointer type %s %s is not supported\n",
6284 func_name, i, btf_type_str(ref_t), ref_tname);
6287 if (!btf_struct_ids_match(log, btf, ref_id, 0, off_desc->kptr.btf,
6288 off_desc->kptr.btf_id, true)) {
6289 bpf_log(log, "kernel function %s args#%d expected pointer to %s %s\n",
6290 func_name, i, btf_type_str(ref_t), ref_tname);
6293 /* rest of the arguments can be anything, like normal kfunc */
6294 } else if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) {
6295 /* If function expects ctx type in BTF check that caller
6296 * is passing PTR_TO_CTX.
6298 if (reg->type != PTR_TO_CTX) {
6300 "arg#%d expected pointer to ctx, but got %s\n",
6301 i, btf_type_str(t));
6304 } else if (is_kfunc && (reg->type == PTR_TO_BTF_ID ||
6305 (reg2btf_ids[base_type(reg->type)] && !type_flag(reg->type)))) {
6306 const struct btf_type *reg_ref_t;
6307 const struct btf *reg_btf;
6308 const char *reg_ref_tname;
6311 if (!btf_type_is_struct(ref_t)) {
6312 bpf_log(log, "kernel function %s args#%d pointer type %s %s is not supported\n",
6313 func_name, i, btf_type_str(ref_t),
6318 if (reg->type == PTR_TO_BTF_ID) {
6320 reg_ref_id = reg->btf_id;
6321 /* Ensure only one argument is referenced PTR_TO_BTF_ID */
6322 if (reg->ref_obj_id) {
6324 bpf_log(log, "verifier internal error: more than one arg with ref_obj_id R%d %u %u\n",
6325 regno, reg->ref_obj_id, ref_obj_id);
6329 ref_obj_id = reg->ref_obj_id;
6332 reg_btf = btf_vmlinux;
6333 reg_ref_id = *reg2btf_ids[base_type(reg->type)];
6336 reg_ref_t = btf_type_skip_modifiers(reg_btf, reg_ref_id,
6338 reg_ref_tname = btf_name_by_offset(reg_btf,
6339 reg_ref_t->name_off);
6340 if (!btf_struct_ids_match(log, reg_btf, reg_ref_id,
6341 reg->off, btf, ref_id, rel && reg->ref_obj_id)) {
6342 bpf_log(log, "kernel function %s args#%d expected pointer to %s %s but R%d has a pointer to %s %s\n",
6344 btf_type_str(ref_t), ref_tname,
6345 regno, btf_type_str(reg_ref_t),
6349 } else if (ptr_to_mem_ok) {
6350 const struct btf_type *resolve_ret;
6354 bool arg_mem_size = i + 1 < nargs && is_kfunc_arg_mem_size(btf, &args[i + 1], ®s[regno + 1]);
6356 /* Permit pointer to mem, but only when argument
6357 * type is pointer to scalar, or struct composed
6358 * (recursively) of scalars.
6359 * When arg_mem_size is true, the pointer can be
6362 if (!btf_type_is_scalar(ref_t) &&
6363 !__btf_type_is_scalar_struct(log, btf, ref_t, 0) &&
6364 (arg_mem_size ? !btf_type_is_void(ref_t) : 1)) {
6366 "arg#%d pointer type %s %s must point to %sscalar, or struct with scalar\n",
6367 i, btf_type_str(ref_t), ref_tname, arg_mem_size ? "void, " : "");
6371 /* Check for mem, len pair */
6373 if (check_kfunc_mem_size_reg(env, ®s[regno + 1], regno + 1)) {
6374 bpf_log(log, "arg#%d arg#%d memory, len pair leads to invalid memory access\n",
6383 resolve_ret = btf_resolve_size(btf, ref_t, &type_size);
6384 if (IS_ERR(resolve_ret)) {
6386 "arg#%d reference type('%s %s') size cannot be determined: %ld\n",
6387 i, btf_type_str(ref_t), ref_tname,
6388 PTR_ERR(resolve_ret));
6392 if (check_mem_reg(env, reg, regno, type_size))
6395 bpf_log(log, "reg type unsupported for arg#%d %sfunction %s#%d\n", i,
6396 is_kfunc ? "kernel " : "", func_name, func_id);
6401 /* Either both are set, or neither */
6402 WARN_ON_ONCE((ref_obj_id && !ref_regno) || (!ref_obj_id && ref_regno));
6403 /* We already made sure ref_obj_id is set only for one argument. We do
6404 * allow (!rel && ref_obj_id), so that passing such referenced
6405 * PTR_TO_BTF_ID to other kfuncs works. Note that rel is only true when
6408 if (rel && !ref_obj_id) {
6409 bpf_log(log, "release kernel function %s expects refcounted PTR_TO_BTF_ID\n",
6413 /* returns argument register number > 0 in case of reference release kfunc */
6414 return rel ? ref_regno : 0;
6417 /* Compare BTF of a function with given bpf_reg_state.
6419 * EFAULT - there is a verifier bug. Abort verification.
6420 * EINVAL - there is a type mismatch or BTF is not available.
6421 * 0 - BTF matches with what bpf_reg_state expects.
6422 * Only PTR_TO_CTX and SCALAR_VALUE states are recognized.
6424 int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog,
6425 struct bpf_reg_state *regs)
6427 struct bpf_prog *prog = env->prog;
6428 struct btf *btf = prog->aux->btf;
6433 if (!prog->aux->func_info)
6436 btf_id = prog->aux->func_info[subprog].type_id;
6440 if (prog->aux->func_info_aux[subprog].unreliable)
6443 is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL;
6444 err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global);
6446 /* Compiler optimizations can remove arguments from static functions
6447 * or mismatched type can be passed into a global function.
6448 * In such cases mark the function as unreliable from BTF point of view.
6451 prog->aux->func_info_aux[subprog].unreliable = true;
6455 int btf_check_kfunc_arg_match(struct bpf_verifier_env *env,
6456 const struct btf *btf, u32 func_id,
6457 struct bpf_reg_state *regs)
6459 return btf_check_func_arg_match(env, btf, func_id, regs, true);
6462 /* Convert BTF of a function into bpf_reg_state if possible
6464 * EFAULT - there is a verifier bug. Abort verification.
6465 * EINVAL - cannot convert BTF.
6466 * 0 - Successfully converted BTF into bpf_reg_state
6467 * (either PTR_TO_CTX or SCALAR_VALUE).
6469 int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
6470 struct bpf_reg_state *regs)
6472 struct bpf_verifier_log *log = &env->log;
6473 struct bpf_prog *prog = env->prog;
6474 enum bpf_prog_type prog_type = prog->type;
6475 struct btf *btf = prog->aux->btf;
6476 const struct btf_param *args;
6477 const struct btf_type *t, *ref_t;
6478 u32 i, nargs, btf_id;
6481 if (!prog->aux->func_info ||
6482 prog->aux->func_info_aux[subprog].linkage != BTF_FUNC_GLOBAL) {
6483 bpf_log(log, "Verifier bug\n");
6487 btf_id = prog->aux->func_info[subprog].type_id;
6489 bpf_log(log, "Global functions need valid BTF\n");
6493 t = btf_type_by_id(btf, btf_id);
6494 if (!t || !btf_type_is_func(t)) {
6495 /* These checks were already done by the verifier while loading
6496 * struct bpf_func_info
6498 bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n",
6502 tname = btf_name_by_offset(btf, t->name_off);
6504 if (log->level & BPF_LOG_LEVEL)
6505 bpf_log(log, "Validating %s() func#%d...\n",
6508 if (prog->aux->func_info_aux[subprog].unreliable) {
6509 bpf_log(log, "Verifier bug in function %s()\n", tname);
6512 if (prog_type == BPF_PROG_TYPE_EXT)
6513 prog_type = prog->aux->dst_prog->type;
6515 t = btf_type_by_id(btf, t->type);
6516 if (!t || !btf_type_is_func_proto(t)) {
6517 bpf_log(log, "Invalid type of function %s()\n", tname);
6520 args = (const struct btf_param *)(t + 1);
6521 nargs = btf_type_vlen(t);
6522 if (nargs > MAX_BPF_FUNC_REG_ARGS) {
6523 bpf_log(log, "Global function %s() with %d > %d args. Buggy compiler.\n",
6524 tname, nargs, MAX_BPF_FUNC_REG_ARGS);
6527 /* check that function returns int */
6528 t = btf_type_by_id(btf, t->type);
6529 while (btf_type_is_modifier(t))
6530 t = btf_type_by_id(btf, t->type);
6531 if (!btf_type_is_int(t) && !btf_is_any_enum(t)) {
6533 "Global function %s() doesn't return scalar. Only those are supported.\n",
6537 /* Convert BTF function arguments into verifier types.
6538 * Only PTR_TO_CTX and SCALAR are supported atm.
6540 for (i = 0; i < nargs; i++) {
6541 struct bpf_reg_state *reg = ®s[i + 1];
6543 t = btf_type_by_id(btf, args[i].type);
6544 while (btf_type_is_modifier(t))
6545 t = btf_type_by_id(btf, t->type);
6546 if (btf_type_is_int(t) || btf_is_any_enum(t)) {
6547 reg->type = SCALAR_VALUE;
6550 if (btf_type_is_ptr(t)) {
6551 if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) {
6552 reg->type = PTR_TO_CTX;
6556 t = btf_type_skip_modifiers(btf, t->type, NULL);
6558 ref_t = btf_resolve_size(btf, t, ®->mem_size);
6559 if (IS_ERR(ref_t)) {
6561 "arg#%d reference type('%s %s') size cannot be determined: %ld\n",
6562 i, btf_type_str(t), btf_name_by_offset(btf, t->name_off),
6567 reg->type = PTR_TO_MEM | PTR_MAYBE_NULL;
6568 reg->id = ++env->id_gen;
6572 bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n",
6573 i, btf_kind_str[BTF_INFO_KIND(t->info)], tname);
6579 static void btf_type_show(const struct btf *btf, u32 type_id, void *obj,
6580 struct btf_show *show)
6582 const struct btf_type *t = btf_type_by_id(btf, type_id);
6585 memset(&show->state, 0, sizeof(show->state));
6586 memset(&show->obj, 0, sizeof(show->obj));
6588 btf_type_ops(t)->show(btf, t, type_id, obj, 0, show);
6591 static void btf_seq_show(struct btf_show *show, const char *fmt,
6594 seq_vprintf((struct seq_file *)show->target, fmt, args);
6597 int btf_type_seq_show_flags(const struct btf *btf, u32 type_id,
6598 void *obj, struct seq_file *m, u64 flags)
6600 struct btf_show sseq;
6603 sseq.showfn = btf_seq_show;
6606 btf_type_show(btf, type_id, obj, &sseq);
6608 return sseq.state.status;
6611 void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
6614 (void) btf_type_seq_show_flags(btf, type_id, obj, m,
6615 BTF_SHOW_NONAME | BTF_SHOW_COMPACT |
6616 BTF_SHOW_ZERO | BTF_SHOW_UNSAFE);
6619 struct btf_show_snprintf {
6620 struct btf_show show;
6621 int len_left; /* space left in string */
6622 int len; /* length we would have written */
6625 static void btf_snprintf_show(struct btf_show *show, const char *fmt,
6628 struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show;
6631 len = vsnprintf(show->target, ssnprintf->len_left, fmt, args);
6634 ssnprintf->len_left = 0;
6635 ssnprintf->len = len;
6636 } else if (len > ssnprintf->len_left) {
6637 /* no space, drive on to get length we would have written */
6638 ssnprintf->len_left = 0;
6639 ssnprintf->len += len;
6641 ssnprintf->len_left -= len;
6642 ssnprintf->len += len;
6643 show->target += len;
6647 int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj,
6648 char *buf, int len, u64 flags)
6650 struct btf_show_snprintf ssnprintf;
6652 ssnprintf.show.target = buf;
6653 ssnprintf.show.flags = flags;
6654 ssnprintf.show.showfn = btf_snprintf_show;
6655 ssnprintf.len_left = len;
6658 btf_type_show(btf, type_id, obj, (struct btf_show *)&ssnprintf);
6660 /* If we encountered an error, return it. */
6661 if (ssnprintf.show.state.status)
6662 return ssnprintf.show.state.status;
6664 /* Otherwise return length we would have written */
6665 return ssnprintf.len;
6668 #ifdef CONFIG_PROC_FS
6669 static void bpf_btf_show_fdinfo(struct seq_file *m, struct file *filp)
6671 const struct btf *btf = filp->private_data;
6673 seq_printf(m, "btf_id:\t%u\n", btf->id);
6677 static int btf_release(struct inode *inode, struct file *filp)
6679 btf_put(filp->private_data);
6683 const struct file_operations btf_fops = {
6684 #ifdef CONFIG_PROC_FS
6685 .show_fdinfo = bpf_btf_show_fdinfo,
6687 .release = btf_release,
6690 static int __btf_new_fd(struct btf *btf)
6692 return anon_inode_getfd("btf", &btf_fops, btf, O_RDONLY | O_CLOEXEC);
6695 int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr)
6700 btf = btf_parse(make_bpfptr(attr->btf, uattr.is_kernel),
6701 attr->btf_size, attr->btf_log_level,
6702 u64_to_user_ptr(attr->btf_log_buf),
6703 attr->btf_log_size);
6705 return PTR_ERR(btf);
6707 ret = btf_alloc_id(btf);
6714 * The BTF ID is published to the userspace.
6715 * All BTF free must go through call_rcu() from
6716 * now on (i.e. free by calling btf_put()).
6719 ret = __btf_new_fd(btf);
6726 struct btf *btf_get_by_fd(int fd)
6734 return ERR_PTR(-EBADF);
6736 if (f.file->f_op != &btf_fops) {
6738 return ERR_PTR(-EINVAL);
6741 btf = f.file->private_data;
6742 refcount_inc(&btf->refcnt);
6748 int btf_get_info_by_fd(const struct btf *btf,
6749 const union bpf_attr *attr,
6750 union bpf_attr __user *uattr)
6752 struct bpf_btf_info __user *uinfo;
6753 struct bpf_btf_info info;
6754 u32 info_copy, btf_copy;
6757 u32 uinfo_len, uname_len, name_len;
6760 uinfo = u64_to_user_ptr(attr->info.info);
6761 uinfo_len = attr->info.info_len;
6763 info_copy = min_t(u32, uinfo_len, sizeof(info));
6764 memset(&info, 0, sizeof(info));
6765 if (copy_from_user(&info, uinfo, info_copy))
6769 ubtf = u64_to_user_ptr(info.btf);
6770 btf_copy = min_t(u32, btf->data_size, info.btf_size);
6771 if (copy_to_user(ubtf, btf->data, btf_copy))
6773 info.btf_size = btf->data_size;
6775 info.kernel_btf = btf->kernel_btf;
6777 uname = u64_to_user_ptr(info.name);
6778 uname_len = info.name_len;
6779 if (!uname ^ !uname_len)
6782 name_len = strlen(btf->name);
6783 info.name_len = name_len;
6786 if (uname_len >= name_len + 1) {
6787 if (copy_to_user(uname, btf->name, name_len + 1))
6792 if (copy_to_user(uname, btf->name, uname_len - 1))
6794 if (put_user(zero, uname + uname_len - 1))
6796 /* let user-space know about too short buffer */
6801 if (copy_to_user(uinfo, &info, info_copy) ||
6802 put_user(info_copy, &uattr->info.info_len))
6808 int btf_get_fd_by_id(u32 id)
6814 btf = idr_find(&btf_idr, id);
6815 if (!btf || !refcount_inc_not_zero(&btf->refcnt))
6816 btf = ERR_PTR(-ENOENT);
6820 return PTR_ERR(btf);
6822 fd = __btf_new_fd(btf);
6829 u32 btf_obj_id(const struct btf *btf)
6834 bool btf_is_kernel(const struct btf *btf)
6836 return btf->kernel_btf;
6839 bool btf_is_module(const struct btf *btf)
6841 return btf->kernel_btf && strcmp(btf->name, "vmlinux") != 0;
6844 static int btf_id_cmp_func(const void *a, const void *b)
6846 const int *pa = a, *pb = b;
6851 bool btf_id_set_contains(const struct btf_id_set *set, u32 id)
6853 return bsearch(&id, set->ids, set->cnt, sizeof(u32), btf_id_cmp_func) != NULL;
6857 BTF_MODULE_F_LIVE = (1 << 0),
6860 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
6862 struct list_head list;
6863 struct module *module;
6865 struct bin_attribute *sysfs_attr;
6869 static LIST_HEAD(btf_modules);
6870 static DEFINE_MUTEX(btf_module_mutex);
6873 btf_module_read(struct file *file, struct kobject *kobj,
6874 struct bin_attribute *bin_attr,
6875 char *buf, loff_t off, size_t len)
6877 const struct btf *btf = bin_attr->private;
6879 memcpy(buf, btf->data + off, len);
6883 static void purge_cand_cache(struct btf *btf);
6885 static int btf_module_notify(struct notifier_block *nb, unsigned long op,
6888 struct btf_module *btf_mod, *tmp;
6889 struct module *mod = module;
6893 if (mod->btf_data_size == 0 ||
6894 (op != MODULE_STATE_COMING && op != MODULE_STATE_LIVE &&
6895 op != MODULE_STATE_GOING))
6899 case MODULE_STATE_COMING:
6900 btf_mod = kzalloc(sizeof(*btf_mod), GFP_KERNEL);
6905 btf = btf_parse_module(mod->name, mod->btf_data, mod->btf_data_size);
6907 pr_warn("failed to validate module [%s] BTF: %ld\n",
6908 mod->name, PTR_ERR(btf));
6910 if (!IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH))
6914 err = btf_alloc_id(btf);
6921 purge_cand_cache(NULL);
6922 mutex_lock(&btf_module_mutex);
6923 btf_mod->module = module;
6925 list_add(&btf_mod->list, &btf_modules);
6926 mutex_unlock(&btf_module_mutex);
6928 if (IS_ENABLED(CONFIG_SYSFS)) {
6929 struct bin_attribute *attr;
6931 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
6935 sysfs_bin_attr_init(attr);
6936 attr->attr.name = btf->name;
6937 attr->attr.mode = 0444;
6938 attr->size = btf->data_size;
6939 attr->private = btf;
6940 attr->read = btf_module_read;
6942 err = sysfs_create_bin_file(btf_kobj, attr);
6944 pr_warn("failed to register module [%s] BTF in sysfs: %d\n",
6951 btf_mod->sysfs_attr = attr;
6955 case MODULE_STATE_LIVE:
6956 mutex_lock(&btf_module_mutex);
6957 list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) {
6958 if (btf_mod->module != module)
6961 btf_mod->flags |= BTF_MODULE_F_LIVE;
6964 mutex_unlock(&btf_module_mutex);
6966 case MODULE_STATE_GOING:
6967 mutex_lock(&btf_module_mutex);
6968 list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) {
6969 if (btf_mod->module != module)
6972 list_del(&btf_mod->list);
6973 if (btf_mod->sysfs_attr)
6974 sysfs_remove_bin_file(btf_kobj, btf_mod->sysfs_attr);
6975 purge_cand_cache(btf_mod->btf);
6976 btf_put(btf_mod->btf);
6977 kfree(btf_mod->sysfs_attr);
6981 mutex_unlock(&btf_module_mutex);
6985 return notifier_from_errno(err);
6988 static struct notifier_block btf_module_nb = {
6989 .notifier_call = btf_module_notify,
6992 static int __init btf_module_init(void)
6994 register_module_notifier(&btf_module_nb);
6998 fs_initcall(btf_module_init);
6999 #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */
7001 struct module *btf_try_get_module(const struct btf *btf)
7003 struct module *res = NULL;
7004 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
7005 struct btf_module *btf_mod, *tmp;
7007 mutex_lock(&btf_module_mutex);
7008 list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) {
7009 if (btf_mod->btf != btf)
7012 /* We must only consider module whose __init routine has
7013 * finished, hence we must check for BTF_MODULE_F_LIVE flag,
7014 * which is set from the notifier callback for
7015 * MODULE_STATE_LIVE.
7017 if ((btf_mod->flags & BTF_MODULE_F_LIVE) && try_module_get(btf_mod->module))
7018 res = btf_mod->module;
7022 mutex_unlock(&btf_module_mutex);
7028 /* Returns struct btf corresponding to the struct module.
7029 * This function can return NULL or ERR_PTR.
7031 static struct btf *btf_get_module_btf(const struct module *module)
7033 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
7034 struct btf_module *btf_mod, *tmp;
7036 struct btf *btf = NULL;
7039 btf = bpf_get_btf_vmlinux();
7040 if (!IS_ERR_OR_NULL(btf))
7045 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
7046 mutex_lock(&btf_module_mutex);
7047 list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) {
7048 if (btf_mod->module != module)
7051 btf_get(btf_mod->btf);
7055 mutex_unlock(&btf_module_mutex);
7061 BPF_CALL_4(bpf_btf_find_by_name_kind, char *, name, int, name_sz, u32, kind, int, flags)
7063 struct btf *btf = NULL;
7070 if (name_sz <= 1 || name[name_sz - 1])
7073 ret = bpf_find_btf_id(name, kind, &btf);
7074 if (ret > 0 && btf_is_module(btf)) {
7075 btf_obj_fd = __btf_new_fd(btf);
7076 if (btf_obj_fd < 0) {
7080 return ret | (((u64)btf_obj_fd) << 32);
7087 const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = {
7088 .func = bpf_btf_find_by_name_kind,
7090 .ret_type = RET_INTEGER,
7091 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
7092 .arg2_type = ARG_CONST_SIZE,
7093 .arg3_type = ARG_ANYTHING,
7094 .arg4_type = ARG_ANYTHING,
7097 BTF_ID_LIST_GLOBAL(btf_tracing_ids, MAX_BTF_TRACING_TYPE)
7098 #define BTF_TRACING_TYPE(name, type) BTF_ID(struct, type)
7099 BTF_TRACING_TYPE_xxx
7100 #undef BTF_TRACING_TYPE
7102 /* Kernel Function (kfunc) BTF ID set registration API */
7104 static int __btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook,
7105 enum btf_kfunc_type type,
7106 struct btf_id_set *add_set, bool vmlinux_set)
7108 struct btf_kfunc_set_tab *tab;
7109 struct btf_id_set *set;
7113 if (hook >= BTF_KFUNC_HOOK_MAX || type >= BTF_KFUNC_TYPE_MAX) {
7121 tab = btf->kfunc_set_tab;
7123 tab = kzalloc(sizeof(*tab), GFP_KERNEL | __GFP_NOWARN);
7126 btf->kfunc_set_tab = tab;
7129 set = tab->sets[hook][type];
7130 /* Warn when register_btf_kfunc_id_set is called twice for the same hook
7133 if (WARN_ON_ONCE(set && !vmlinux_set)) {
7138 /* We don't need to allocate, concatenate, and sort module sets, because
7139 * only one is allowed per hook. Hence, we can directly assign the
7140 * pointer and return.
7143 tab->sets[hook][type] = add_set;
7147 /* In case of vmlinux sets, there may be more than one set being
7148 * registered per hook. To create a unified set, we allocate a new set
7149 * and concatenate all individual sets being registered. While each set
7150 * is individually sorted, they may become unsorted when concatenated,
7151 * hence re-sorting the final set again is required to make binary
7152 * searching the set using btf_id_set_contains function work.
7154 set_cnt = set ? set->cnt : 0;
7156 if (set_cnt > U32_MAX - add_set->cnt) {
7161 if (set_cnt + add_set->cnt > BTF_KFUNC_SET_MAX_CNT) {
7167 set = krealloc(tab->sets[hook][type],
7168 offsetof(struct btf_id_set, ids[set_cnt + add_set->cnt]),
7169 GFP_KERNEL | __GFP_NOWARN);
7175 /* For newly allocated set, initialize set->cnt to 0 */
7176 if (!tab->sets[hook][type])
7178 tab->sets[hook][type] = set;
7180 /* Concatenate the two sets */
7181 memcpy(set->ids + set->cnt, add_set->ids, add_set->cnt * sizeof(set->ids[0]));
7182 set->cnt += add_set->cnt;
7184 sort(set->ids, set->cnt, sizeof(set->ids[0]), btf_id_cmp_func, NULL);
7188 btf_free_kfunc_set_tab(btf);
7192 static int btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook,
7193 const struct btf_kfunc_id_set *kset)
7195 bool vmlinux_set = !btf_is_module(btf);
7198 for (type = 0; type < ARRAY_SIZE(kset->sets); type++) {
7199 if (!kset->sets[type])
7202 ret = __btf_populate_kfunc_set(btf, hook, type, kset->sets[type], vmlinux_set);
7209 static bool __btf_kfunc_id_set_contains(const struct btf *btf,
7210 enum btf_kfunc_hook hook,
7211 enum btf_kfunc_type type,
7214 struct btf_id_set *set;
7216 if (hook >= BTF_KFUNC_HOOK_MAX || type >= BTF_KFUNC_TYPE_MAX)
7218 if (!btf->kfunc_set_tab)
7220 set = btf->kfunc_set_tab->sets[hook][type];
7223 return btf_id_set_contains(set, kfunc_btf_id);
7226 static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type)
7228 switch (prog_type) {
7229 case BPF_PROG_TYPE_XDP:
7230 return BTF_KFUNC_HOOK_XDP;
7231 case BPF_PROG_TYPE_SCHED_CLS:
7232 return BTF_KFUNC_HOOK_TC;
7233 case BPF_PROG_TYPE_STRUCT_OPS:
7234 return BTF_KFUNC_HOOK_STRUCT_OPS;
7235 case BPF_PROG_TYPE_TRACING:
7236 return BTF_KFUNC_HOOK_TRACING;
7237 case BPF_PROG_TYPE_SYSCALL:
7238 return BTF_KFUNC_HOOK_SYSCALL;
7240 return BTF_KFUNC_HOOK_MAX;
7245 * Reference to the module (obtained using btf_try_get_module) corresponding to
7246 * the struct btf *MUST* be held when calling this function from verifier
7247 * context. This is usually true as we stash references in prog's kfunc_btf_tab;
7248 * keeping the reference for the duration of the call provides the necessary
7249 * protection for looking up a well-formed btf->kfunc_set_tab.
7251 bool btf_kfunc_id_set_contains(const struct btf *btf,
7252 enum bpf_prog_type prog_type,
7253 enum btf_kfunc_type type, u32 kfunc_btf_id)
7255 enum btf_kfunc_hook hook;
7257 hook = bpf_prog_type_to_kfunc_hook(prog_type);
7258 return __btf_kfunc_id_set_contains(btf, hook, type, kfunc_btf_id);
7261 /* This function must be invoked only from initcalls/module init functions */
7262 int register_btf_kfunc_id_set(enum bpf_prog_type prog_type,
7263 const struct btf_kfunc_id_set *kset)
7265 enum btf_kfunc_hook hook;
7269 btf = btf_get_module_btf(kset->owner);
7271 if (!kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) {
7272 pr_err("missing vmlinux BTF, cannot register kfuncs\n");
7275 if (kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) {
7276 pr_err("missing module BTF, cannot register kfuncs\n");
7282 return PTR_ERR(btf);
7284 hook = bpf_prog_type_to_kfunc_hook(prog_type);
7285 ret = btf_populate_kfunc_set(btf, hook, kset);
7289 EXPORT_SYMBOL_GPL(register_btf_kfunc_id_set);
7291 s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id)
7293 struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab;
7294 struct btf_id_dtor_kfunc *dtor;
7298 /* Even though the size of tab->dtors[0] is > sizeof(u32), we only need
7299 * to compare the first u32 with btf_id, so we can reuse btf_id_cmp_func.
7301 BUILD_BUG_ON(offsetof(struct btf_id_dtor_kfunc, btf_id) != 0);
7302 dtor = bsearch(&btf_id, tab->dtors, tab->cnt, sizeof(tab->dtors[0]), btf_id_cmp_func);
7305 return dtor->kfunc_btf_id;
7308 static int btf_check_dtor_kfuncs(struct btf *btf, const struct btf_id_dtor_kfunc *dtors, u32 cnt)
7310 const struct btf_type *dtor_func, *dtor_func_proto, *t;
7311 const struct btf_param *args;
7315 for (i = 0; i < cnt; i++) {
7316 dtor_btf_id = dtors[i].kfunc_btf_id;
7318 dtor_func = btf_type_by_id(btf, dtor_btf_id);
7319 if (!dtor_func || !btf_type_is_func(dtor_func))
7322 dtor_func_proto = btf_type_by_id(btf, dtor_func->type);
7323 if (!dtor_func_proto || !btf_type_is_func_proto(dtor_func_proto))
7326 /* Make sure the prototype of the destructor kfunc is 'void func(type *)' */
7327 t = btf_type_by_id(btf, dtor_func_proto->type);
7328 if (!t || !btf_type_is_void(t))
7331 nr_args = btf_type_vlen(dtor_func_proto);
7334 args = btf_params(dtor_func_proto);
7335 t = btf_type_by_id(btf, args[0].type);
7336 /* Allow any pointer type, as width on targets Linux supports
7337 * will be same for all pointer types (i.e. sizeof(void *))
7339 if (!t || !btf_type_is_ptr(t))
7345 /* This function must be invoked only from initcalls/module init functions */
7346 int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_cnt,
7347 struct module *owner)
7349 struct btf_id_dtor_kfunc_tab *tab;
7354 btf = btf_get_module_btf(owner);
7356 if (!owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) {
7357 pr_err("missing vmlinux BTF, cannot register dtor kfuncs\n");
7360 if (owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) {
7361 pr_err("missing module BTF, cannot register dtor kfuncs\n");
7367 return PTR_ERR(btf);
7369 if (add_cnt >= BTF_DTOR_KFUNC_MAX_CNT) {
7370 pr_err("cannot register more than %d kfunc destructors\n", BTF_DTOR_KFUNC_MAX_CNT);
7375 /* Ensure that the prototype of dtor kfuncs being registered is sane */
7376 ret = btf_check_dtor_kfuncs(btf, dtors, add_cnt);
7380 tab = btf->dtor_kfunc_tab;
7381 /* Only one call allowed for modules */
7382 if (WARN_ON_ONCE(tab && btf_is_module(btf))) {
7387 tab_cnt = tab ? tab->cnt : 0;
7388 if (tab_cnt > U32_MAX - add_cnt) {
7392 if (tab_cnt + add_cnt >= BTF_DTOR_KFUNC_MAX_CNT) {
7393 pr_err("cannot register more than %d kfunc destructors\n", BTF_DTOR_KFUNC_MAX_CNT);
7398 tab = krealloc(btf->dtor_kfunc_tab,
7399 offsetof(struct btf_id_dtor_kfunc_tab, dtors[tab_cnt + add_cnt]),
7400 GFP_KERNEL | __GFP_NOWARN);
7406 if (!btf->dtor_kfunc_tab)
7408 btf->dtor_kfunc_tab = tab;
7410 memcpy(tab->dtors + tab->cnt, dtors, add_cnt * sizeof(tab->dtors[0]));
7411 tab->cnt += add_cnt;
7413 sort(tab->dtors, tab->cnt, sizeof(tab->dtors[0]), btf_id_cmp_func, NULL);
7417 btf_free_dtor_kfunc_tab(btf);
7421 EXPORT_SYMBOL_GPL(register_btf_id_dtor_kfuncs);
7423 #define MAX_TYPES_ARE_COMPAT_DEPTH 2
7425 /* Check local and target types for compatibility. This check is used for
7426 * type-based CO-RE relocations and follow slightly different rules than
7427 * field-based relocations. This function assumes that root types were already
7428 * checked for name match. Beyond that initial root-level name check, names
7429 * are completely ignored. Compatibility rules are as follows:
7430 * - any two STRUCTs/UNIONs/FWDs/ENUMs/INTs/ENUM64s are considered compatible, but
7431 * kind should match for local and target types (i.e., STRUCT is not
7432 * compatible with UNION);
7433 * - for ENUMs/ENUM64s, the size is ignored;
7434 * - for INT, size and signedness are ignored;
7435 * - for ARRAY, dimensionality is ignored, element types are checked for
7436 * compatibility recursively;
7437 * - CONST/VOLATILE/RESTRICT modifiers are ignored;
7438 * - TYPEDEFs/PTRs are compatible if types they pointing to are compatible;
7439 * - FUNC_PROTOs are compatible if they have compatible signature: same
7440 * number of input args and compatible return and argument types.
7441 * These rules are not set in stone and probably will be adjusted as we get
7442 * more experience with using BPF CO-RE relocations.
7444 int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,
7445 const struct btf *targ_btf, __u32 targ_id)
7447 return __bpf_core_types_are_compat(local_btf, local_id, targ_btf, targ_id,
7448 MAX_TYPES_ARE_COMPAT_DEPTH);
7451 #define MAX_TYPES_MATCH_DEPTH 2
7453 int bpf_core_types_match(const struct btf *local_btf, u32 local_id,
7454 const struct btf *targ_btf, u32 targ_id)
7456 return __bpf_core_types_match(local_btf, local_id, targ_btf, targ_id, false,
7457 MAX_TYPES_MATCH_DEPTH);
7460 static bool bpf_core_is_flavor_sep(const char *s)
7462 /* check X___Y name pattern, where X and Y are not underscores */
7463 return s[0] != '_' && /* X */
7464 s[1] == '_' && s[2] == '_' && s[3] == '_' && /* ___ */
7465 s[4] != '_'; /* Y */
7468 size_t bpf_core_essential_name_len(const char *name)
7470 size_t n = strlen(name);
7473 for (i = n - 5; i >= 0; i--) {
7474 if (bpf_core_is_flavor_sep(name + i))
7480 struct bpf_cand_cache {
7486 const struct btf *btf;
7491 static void bpf_free_cands(struct bpf_cand_cache *cands)
7494 /* empty candidate array was allocated on stack */
7499 static void bpf_free_cands_from_cache(struct bpf_cand_cache *cands)
7505 #define VMLINUX_CAND_CACHE_SIZE 31
7506 static struct bpf_cand_cache *vmlinux_cand_cache[VMLINUX_CAND_CACHE_SIZE];
7508 #define MODULE_CAND_CACHE_SIZE 31
7509 static struct bpf_cand_cache *module_cand_cache[MODULE_CAND_CACHE_SIZE];
7511 static DEFINE_MUTEX(cand_cache_mutex);
7513 static void __print_cand_cache(struct bpf_verifier_log *log,
7514 struct bpf_cand_cache **cache,
7517 struct bpf_cand_cache *cc;
7520 for (i = 0; i < cache_size; i++) {
7524 bpf_log(log, "[%d]%s(", i, cc->name);
7525 for (j = 0; j < cc->cnt; j++) {
7526 bpf_log(log, "%d", cc->cands[j].id);
7527 if (j < cc->cnt - 1)
7530 bpf_log(log, "), ");
7534 static void print_cand_cache(struct bpf_verifier_log *log)
7536 mutex_lock(&cand_cache_mutex);
7537 bpf_log(log, "vmlinux_cand_cache:");
7538 __print_cand_cache(log, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE);
7539 bpf_log(log, "\nmodule_cand_cache:");
7540 __print_cand_cache(log, module_cand_cache, MODULE_CAND_CACHE_SIZE);
7542 mutex_unlock(&cand_cache_mutex);
7545 static u32 hash_cands(struct bpf_cand_cache *cands)
7547 return jhash(cands->name, cands->name_len, 0);
7550 static struct bpf_cand_cache *check_cand_cache(struct bpf_cand_cache *cands,
7551 struct bpf_cand_cache **cache,
7554 struct bpf_cand_cache *cc = cache[hash_cands(cands) % cache_size];
7556 if (cc && cc->name_len == cands->name_len &&
7557 !strncmp(cc->name, cands->name, cands->name_len))
7562 static size_t sizeof_cands(int cnt)
7564 return offsetof(struct bpf_cand_cache, cands[cnt]);
7567 static struct bpf_cand_cache *populate_cand_cache(struct bpf_cand_cache *cands,
7568 struct bpf_cand_cache **cache,
7571 struct bpf_cand_cache **cc = &cache[hash_cands(cands) % cache_size], *new_cands;
7574 bpf_free_cands_from_cache(*cc);
7577 new_cands = kmemdup(cands, sizeof_cands(cands->cnt), GFP_KERNEL);
7579 bpf_free_cands(cands);
7580 return ERR_PTR(-ENOMEM);
7582 /* strdup the name, since it will stay in cache.
7583 * the cands->name points to strings in prog's BTF and the prog can be unloaded.
7585 new_cands->name = kmemdup_nul(cands->name, cands->name_len, GFP_KERNEL);
7586 bpf_free_cands(cands);
7587 if (!new_cands->name) {
7589 return ERR_PTR(-ENOMEM);
7595 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
7596 static void __purge_cand_cache(struct btf *btf, struct bpf_cand_cache **cache,
7599 struct bpf_cand_cache *cc;
7602 for (i = 0; i < cache_size; i++) {
7607 /* when new module is loaded purge all of module_cand_cache,
7608 * since new module might have candidates with the name
7609 * that matches cached cands.
7611 bpf_free_cands_from_cache(cc);
7615 /* when module is unloaded purge cache entries
7616 * that match module's btf
7618 for (j = 0; j < cc->cnt; j++)
7619 if (cc->cands[j].btf == btf) {
7620 bpf_free_cands_from_cache(cc);
7628 static void purge_cand_cache(struct btf *btf)
7630 mutex_lock(&cand_cache_mutex);
7631 __purge_cand_cache(btf, module_cand_cache, MODULE_CAND_CACHE_SIZE);
7632 mutex_unlock(&cand_cache_mutex);
7636 static struct bpf_cand_cache *
7637 bpf_core_add_cands(struct bpf_cand_cache *cands, const struct btf *targ_btf,
7640 struct bpf_cand_cache *new_cands;
7641 const struct btf_type *t;
7642 const char *targ_name;
7643 size_t targ_essent_len;
7646 n = btf_nr_types(targ_btf);
7647 for (i = targ_start_id; i < n; i++) {
7648 t = btf_type_by_id(targ_btf, i);
7649 if (btf_kind(t) != cands->kind)
7652 targ_name = btf_name_by_offset(targ_btf, t->name_off);
7656 /* the resched point is before strncmp to make sure that search
7657 * for non-existing name will have a chance to schedule().
7661 if (strncmp(cands->name, targ_name, cands->name_len) != 0)
7664 targ_essent_len = bpf_core_essential_name_len(targ_name);
7665 if (targ_essent_len != cands->name_len)
7668 /* most of the time there is only one candidate for a given kind+name pair */
7669 new_cands = kmalloc(sizeof_cands(cands->cnt + 1), GFP_KERNEL);
7671 bpf_free_cands(cands);
7672 return ERR_PTR(-ENOMEM);
7675 memcpy(new_cands, cands, sizeof_cands(cands->cnt));
7676 bpf_free_cands(cands);
7678 cands->cands[cands->cnt].btf = targ_btf;
7679 cands->cands[cands->cnt].id = i;
7685 static struct bpf_cand_cache *
7686 bpf_core_find_cands(struct bpf_core_ctx *ctx, u32 local_type_id)
7688 struct bpf_cand_cache *cands, *cc, local_cand = {};
7689 const struct btf *local_btf = ctx->btf;
7690 const struct btf_type *local_type;
7691 const struct btf *main_btf;
7692 size_t local_essent_len;
7693 struct btf *mod_btf;
7697 main_btf = bpf_get_btf_vmlinux();
7698 if (IS_ERR(main_btf))
7699 return ERR_CAST(main_btf);
7701 return ERR_PTR(-EINVAL);
7703 local_type = btf_type_by_id(local_btf, local_type_id);
7705 return ERR_PTR(-EINVAL);
7707 name = btf_name_by_offset(local_btf, local_type->name_off);
7708 if (str_is_empty(name))
7709 return ERR_PTR(-EINVAL);
7710 local_essent_len = bpf_core_essential_name_len(name);
7712 cands = &local_cand;
7714 cands->kind = btf_kind(local_type);
7715 cands->name_len = local_essent_len;
7717 cc = check_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE);
7718 /* cands is a pointer to stack here */
7725 /* Attempt to find target candidates in vmlinux BTF first */
7726 cands = bpf_core_add_cands(cands, main_btf, 1);
7728 return ERR_CAST(cands);
7730 /* cands is a pointer to kmalloced memory here if cands->cnt > 0 */
7732 /* populate cache even when cands->cnt == 0 */
7733 cc = populate_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE);
7735 return ERR_CAST(cc);
7737 /* if vmlinux BTF has any candidate, don't go for module BTFs */
7742 /* cands is a pointer to stack here and cands->cnt == 0 */
7743 cc = check_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE);
7745 /* if cache has it return it even if cc->cnt == 0 */
7748 /* If candidate is not found in vmlinux's BTF then search in module's BTFs */
7749 spin_lock_bh(&btf_idr_lock);
7750 idr_for_each_entry(&btf_idr, mod_btf, id) {
7751 if (!btf_is_module(mod_btf))
7753 /* linear search could be slow hence unlock/lock
7754 * the IDR to avoiding holding it for too long
7757 spin_unlock_bh(&btf_idr_lock);
7758 cands = bpf_core_add_cands(cands, mod_btf, btf_nr_types(main_btf));
7759 if (IS_ERR(cands)) {
7761 return ERR_CAST(cands);
7763 spin_lock_bh(&btf_idr_lock);
7766 spin_unlock_bh(&btf_idr_lock);
7767 /* cands is a pointer to kmalloced memory here if cands->cnt > 0
7768 * or pointer to stack if cands->cnd == 0.
7769 * Copy it into the cache even when cands->cnt == 0 and
7770 * return the result.
7772 return populate_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE);
7775 int bpf_core_apply(struct bpf_core_ctx *ctx, const struct bpf_core_relo *relo,
7776 int relo_idx, void *insn)
7778 bool need_cands = relo->kind != BPF_CORE_TYPE_ID_LOCAL;
7779 struct bpf_core_cand_list cands = {};
7780 struct bpf_core_relo_res targ_res;
7781 struct bpf_core_spec *specs;
7784 /* ~4k of temp memory necessary to convert LLVM spec like "0:1:0:5"
7785 * into arrays of btf_ids of struct fields and array indices.
7787 specs = kcalloc(3, sizeof(*specs), GFP_KERNEL);
7792 struct bpf_cand_cache *cc;
7795 mutex_lock(&cand_cache_mutex);
7796 cc = bpf_core_find_cands(ctx, relo->type_id);
7798 bpf_log(ctx->log, "target candidate search failed for %d\n",
7804 cands.cands = kcalloc(cc->cnt, sizeof(*cands.cands), GFP_KERNEL);
7810 for (i = 0; i < cc->cnt; i++) {
7812 "CO-RE relocating %s %s: found target candidate [%d]\n",
7813 btf_kind_str[cc->kind], cc->name, cc->cands[i].id);
7814 cands.cands[i].btf = cc->cands[i].btf;
7815 cands.cands[i].id = cc->cands[i].id;
7817 cands.len = cc->cnt;
7818 /* cand_cache_mutex needs to span the cache lookup and
7819 * copy of btf pointer into bpf_core_cand_list,
7820 * since module can be unloaded while bpf_core_calc_relo_insn
7821 * is working with module's btf.
7825 err = bpf_core_calc_relo_insn((void *)ctx->log, relo, relo_idx, ctx->btf, &cands, specs,
7830 err = bpf_core_patch_insn((void *)ctx->log, insn, relo->insn_off / 8, relo, relo_idx,
7837 mutex_unlock(&cand_cache_mutex);
7838 if (ctx->log->level & BPF_LOG_LEVEL2)
7839 print_cand_cache(ctx->log);