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>
29 /* BTF (BPF Type Format) is the meta data format which describes
30 * the data types of BPF program/map. Hence, it basically focus
31 * on the C programming language which the modern BPF is primary
36 * The BTF data is stored under the ".BTF" ELF section
40 * Each 'struct btf_type' object describes a C data type.
41 * Depending on the type it is describing, a 'struct btf_type'
42 * object may be followed by more data. F.e.
43 * To describe an array, 'struct btf_type' is followed by
46 * 'struct btf_type' and any extra data following it are
51 * The BTF type section contains a list of 'struct btf_type' objects.
52 * Each one describes a C type. Recall from the above section
53 * that a 'struct btf_type' object could be immediately followed by extra
54 * data in order to describe some particular C types.
58 * Each btf_type object is identified by a type_id. The type_id
59 * is implicitly implied by the location of the btf_type object in
60 * the BTF type section. The first one has type_id 1. The second
61 * one has type_id 2...etc. Hence, an earlier btf_type has
64 * A btf_type object may refer to another btf_type object by using
65 * type_id (i.e. the "type" in the "struct btf_type").
67 * NOTE that we cannot assume any reference-order.
68 * A btf_type object can refer to an earlier btf_type object
69 * but it can also refer to a later btf_type object.
71 * For example, to describe "const void *". A btf_type
72 * object describing "const" may refer to another btf_type
73 * object describing "void *". This type-reference is done
74 * by specifying type_id:
76 * [1] CONST (anon) type_id=2
77 * [2] PTR (anon) type_id=0
79 * The above is the btf_verifier debug log:
80 * - Each line started with "[?]" is a btf_type object
81 * - [?] is the type_id of the btf_type object.
82 * - CONST/PTR is the BTF_KIND_XXX
83 * - "(anon)" is the name of the type. It just
84 * happens that CONST and PTR has no name.
85 * - type_id=XXX is the 'u32 type' in btf_type
87 * NOTE: "void" has type_id 0
91 * The BTF string section contains the names used by the type section.
92 * Each string is referred by an "offset" from the beginning of the
95 * Each string is '\0' terminated.
97 * The first character in the string section must be '\0'
98 * which is used to mean 'anonymous'. Some btf_type may not
104 * To verify BTF data, two passes are needed.
108 * The first pass is to collect all btf_type objects to
109 * an array: "btf->types".
111 * Depending on the C type that a btf_type is describing,
112 * a btf_type may be followed by extra data. We don't know
113 * how many btf_type is there, and more importantly we don't
114 * know where each btf_type is located in the type section.
116 * Without knowing the location of each type_id, most verifications
117 * cannot be done. e.g. an earlier btf_type may refer to a later
118 * btf_type (recall the "const void *" above), so we cannot
119 * check this type-reference in the first pass.
121 * In the first pass, it still does some verifications (e.g.
122 * checking the name is a valid offset to the string section).
126 * The main focus is to resolve a btf_type that is referring
129 * We have to ensure the referring type:
130 * 1) does exist in the BTF (i.e. in btf->types[])
131 * 2) does not cause a loop:
140 * btf_type_needs_resolve() decides if a btf_type needs
143 * The needs_resolve type implements the "resolve()" ops which
144 * essentially does a DFS and detects backedge.
146 * During resolve (or DFS), different C types have different
147 * "RESOLVED" conditions.
149 * When resolving a BTF_KIND_STRUCT, we need to resolve all its
150 * members because a member is always referring to another
151 * type. A struct's member can be treated as "RESOLVED" if
152 * it is referring to a BTF_KIND_PTR. Otherwise, the
153 * following valid C struct would be rejected:
160 * When resolving a BTF_KIND_PTR, it needs to keep resolving if
161 * it is referring to another BTF_KIND_PTR. Otherwise, we cannot
162 * detect a pointer loop, e.g.:
163 * BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR +
165 * +-----------------------------------------+
169 #define BITS_PER_U128 (sizeof(u64) * BITS_PER_BYTE * 2)
170 #define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1)
171 #define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK)
172 #define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3)
173 #define BITS_ROUNDUP_BYTES(bits) \
174 (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits))
176 #define BTF_INFO_MASK 0x9f00ffff
177 #define BTF_INT_MASK 0x0fffffff
178 #define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE)
179 #define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET)
181 /* 16MB for 64k structs and each has 16 members and
182 * a few MB spaces for the string section.
183 * The hard limit is S32_MAX.
185 #define BTF_MAX_SIZE (16 * 1024 * 1024)
187 #define for_each_member_from(i, from, struct_type, member) \
188 for (i = from, member = btf_type_member(struct_type) + from; \
189 i < btf_type_vlen(struct_type); \
192 #define for_each_vsi_from(i, from, struct_type, member) \
193 for (i = from, member = btf_type_var_secinfo(struct_type) + from; \
194 i < btf_type_vlen(struct_type); \
198 DEFINE_SPINLOCK(btf_idr_lock);
202 struct btf_type **types;
207 struct btf_header hdr;
208 u32 nr_types; /* includes VOID for base BTF */
215 /* split BTF support */
216 struct btf *base_btf;
217 u32 start_id; /* first type ID in this BTF (0 for base BTF) */
218 u32 start_str_off; /* first string offset (0 for base BTF) */
219 char name[MODULE_NAME_LEN];
223 enum verifier_phase {
228 struct resolve_vertex {
229 const struct btf_type *t;
241 RESOLVE_TBD, /* To Be Determined */
242 RESOLVE_PTR, /* Resolving for Pointer */
243 RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union
248 #define MAX_RESOLVE_DEPTH 32
250 struct btf_sec_info {
255 struct btf_verifier_env {
258 struct resolve_vertex stack[MAX_RESOLVE_DEPTH];
259 struct bpf_verifier_log log;
262 enum verifier_phase phase;
263 enum resolve_mode resolve_mode;
266 static const char * const btf_kind_str[NR_BTF_KINDS] = {
267 [BTF_KIND_UNKN] = "UNKNOWN",
268 [BTF_KIND_INT] = "INT",
269 [BTF_KIND_PTR] = "PTR",
270 [BTF_KIND_ARRAY] = "ARRAY",
271 [BTF_KIND_STRUCT] = "STRUCT",
272 [BTF_KIND_UNION] = "UNION",
273 [BTF_KIND_ENUM] = "ENUM",
274 [BTF_KIND_FWD] = "FWD",
275 [BTF_KIND_TYPEDEF] = "TYPEDEF",
276 [BTF_KIND_VOLATILE] = "VOLATILE",
277 [BTF_KIND_CONST] = "CONST",
278 [BTF_KIND_RESTRICT] = "RESTRICT",
279 [BTF_KIND_FUNC] = "FUNC",
280 [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO",
281 [BTF_KIND_VAR] = "VAR",
282 [BTF_KIND_DATASEC] = "DATASEC",
283 [BTF_KIND_FLOAT] = "FLOAT",
286 const char *btf_type_str(const struct btf_type *t)
288 return btf_kind_str[BTF_INFO_KIND(t->info)];
291 /* Chunk size we use in safe copy of data to be shown. */
292 #define BTF_SHOW_OBJ_SAFE_SIZE 32
295 * This is the maximum size of a base type value (equivalent to a
296 * 128-bit int); if we are at the end of our safe buffer and have
297 * less than 16 bytes space we can't be assured of being able
298 * to copy the next type safely, so in such cases we will initiate
301 #define BTF_SHOW_OBJ_BASE_TYPE_SIZE 16
304 #define BTF_SHOW_NAME_SIZE 80
307 * Common data to all BTF show operations. Private show functions can add
308 * their own data to a structure containing a struct btf_show and consult it
309 * in the show callback. See btf_type_show() below.
311 * One challenge with showing nested data is we want to skip 0-valued
312 * data, but in order to figure out whether a nested object is all zeros
313 * we need to walk through it. As a result, we need to make two passes
314 * when handling structs, unions and arrays; the first path simply looks
315 * for nonzero data, while the second actually does the display. The first
316 * pass is signalled by show->state.depth_check being set, and if we
317 * encounter a non-zero value we set show->state.depth_to_show to
318 * the depth at which we encountered it. When we have completed the
319 * first pass, we will know if anything needs to be displayed if
320 * depth_to_show > depth. See btf_[struct,array]_show() for the
321 * implementation of this.
323 * Another problem is we want to ensure the data for display is safe to
324 * access. To support this, the anonymous "struct {} obj" tracks the data
325 * object and our safe copy of it. We copy portions of the data needed
326 * to the object "copy" buffer, but because its size is limited to
327 * BTF_SHOW_OBJ_COPY_LEN bytes, multiple copies may be required as we
328 * traverse larger objects for display.
330 * The various data type show functions all start with a call to
331 * btf_show_start_type() which returns a pointer to the safe copy
332 * of the data needed (or if BTF_SHOW_UNSAFE is specified, to the
333 * raw data itself). btf_show_obj_safe() is responsible for
334 * using copy_from_kernel_nofault() to update the safe data if necessary
335 * as we traverse the object's data. skbuff-like semantics are
338 * - obj.head points to the start of the toplevel object for display
339 * - obj.size is the size of the toplevel object
340 * - obj.data points to the current point in the original data at
341 * which our safe data starts. obj.data will advance as we copy
342 * portions of the data.
344 * In most cases a single copy will suffice, but larger data structures
345 * such as "struct task_struct" will require many copies. The logic in
346 * btf_show_obj_safe() handles the logic that determines if a new
347 * copy_from_kernel_nofault() is needed.
351 void *target; /* target of show operation (seq file, buffer) */
352 void (*showfn)(struct btf_show *show, const char *fmt, va_list args);
353 const struct btf *btf;
354 /* below are used during iteration */
363 int status; /* non-zero for error */
364 const struct btf_type *type;
365 const struct btf_member *member;
366 char name[BTF_SHOW_NAME_SIZE]; /* space for member name/type */
372 u8 safe[BTF_SHOW_OBJ_SAFE_SIZE];
376 struct btf_kind_operations {
377 s32 (*check_meta)(struct btf_verifier_env *env,
378 const struct btf_type *t,
380 int (*resolve)(struct btf_verifier_env *env,
381 const struct resolve_vertex *v);
382 int (*check_member)(struct btf_verifier_env *env,
383 const struct btf_type *struct_type,
384 const struct btf_member *member,
385 const struct btf_type *member_type);
386 int (*check_kflag_member)(struct btf_verifier_env *env,
387 const struct btf_type *struct_type,
388 const struct btf_member *member,
389 const struct btf_type *member_type);
390 void (*log_details)(struct btf_verifier_env *env,
391 const struct btf_type *t);
392 void (*show)(const struct btf *btf, const struct btf_type *t,
393 u32 type_id, void *data, u8 bits_offsets,
394 struct btf_show *show);
397 static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS];
398 static struct btf_type btf_void;
400 static int btf_resolve(struct btf_verifier_env *env,
401 const struct btf_type *t, u32 type_id);
403 static bool btf_type_is_modifier(const struct btf_type *t)
405 /* Some of them is not strictly a C modifier
406 * but they are grouped into the same bucket
408 * A type (t) that refers to another
409 * type through t->type AND its size cannot
410 * be determined without following the t->type.
412 * ptr does not fall into this bucket
413 * because its size is always sizeof(void *).
415 switch (BTF_INFO_KIND(t->info)) {
416 case BTF_KIND_TYPEDEF:
417 case BTF_KIND_VOLATILE:
419 case BTF_KIND_RESTRICT:
426 bool btf_type_is_void(const struct btf_type *t)
428 return t == &btf_void;
431 static bool btf_type_is_fwd(const struct btf_type *t)
433 return BTF_INFO_KIND(t->info) == BTF_KIND_FWD;
436 static bool btf_type_nosize(const struct btf_type *t)
438 return btf_type_is_void(t) || btf_type_is_fwd(t) ||
439 btf_type_is_func(t) || btf_type_is_func_proto(t);
442 static bool btf_type_nosize_or_null(const struct btf_type *t)
444 return !t || btf_type_nosize(t);
447 static bool __btf_type_is_struct(const struct btf_type *t)
449 return BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT;
452 static bool btf_type_is_array(const struct btf_type *t)
454 return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY;
457 static bool btf_type_is_datasec(const struct btf_type *t)
459 return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC;
462 u32 btf_nr_types(const struct btf *btf)
467 total += btf->nr_types;
474 s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind)
476 const struct btf_type *t;
480 total = btf_nr_types(btf);
481 for (i = 1; i < total; i++) {
482 t = btf_type_by_id(btf, i);
483 if (BTF_INFO_KIND(t->info) != kind)
486 tname = btf_name_by_offset(btf, t->name_off);
487 if (!strcmp(tname, name))
494 const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
497 const struct btf_type *t = btf_type_by_id(btf, id);
499 while (btf_type_is_modifier(t)) {
501 t = btf_type_by_id(btf, t->type);
510 const struct btf_type *btf_type_resolve_ptr(const struct btf *btf,
513 const struct btf_type *t;
515 t = btf_type_skip_modifiers(btf, id, NULL);
516 if (!btf_type_is_ptr(t))
519 return btf_type_skip_modifiers(btf, t->type, res_id);
522 const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
525 const struct btf_type *ptype;
527 ptype = btf_type_resolve_ptr(btf, id, res_id);
528 if (ptype && btf_type_is_func_proto(ptype))
534 /* Types that act only as a source, not sink or intermediate
535 * type when resolving.
537 static bool btf_type_is_resolve_source_only(const struct btf_type *t)
539 return btf_type_is_var(t) ||
540 btf_type_is_datasec(t);
543 /* What types need to be resolved?
545 * btf_type_is_modifier() is an obvious one.
547 * btf_type_is_struct() because its member refers to
548 * another type (through member->type).
550 * btf_type_is_var() because the variable refers to
551 * another type. btf_type_is_datasec() holds multiple
552 * btf_type_is_var() types that need resolving.
554 * btf_type_is_array() because its element (array->type)
555 * refers to another type. Array can be thought of a
556 * special case of struct while array just has the same
557 * member-type repeated by array->nelems of times.
559 static bool btf_type_needs_resolve(const struct btf_type *t)
561 return btf_type_is_modifier(t) ||
562 btf_type_is_ptr(t) ||
563 btf_type_is_struct(t) ||
564 btf_type_is_array(t) ||
565 btf_type_is_var(t) ||
566 btf_type_is_datasec(t);
569 /* t->size can be used */
570 static bool btf_type_has_size(const struct btf_type *t)
572 switch (BTF_INFO_KIND(t->info)) {
574 case BTF_KIND_STRUCT:
577 case BTF_KIND_DATASEC:
585 static const char *btf_int_encoding_str(u8 encoding)
589 else if (encoding == BTF_INT_SIGNED)
591 else if (encoding == BTF_INT_CHAR)
593 else if (encoding == BTF_INT_BOOL)
599 static u32 btf_type_int(const struct btf_type *t)
601 return *(u32 *)(t + 1);
604 static const struct btf_array *btf_type_array(const struct btf_type *t)
606 return (const struct btf_array *)(t + 1);
609 static const struct btf_enum *btf_type_enum(const struct btf_type *t)
611 return (const struct btf_enum *)(t + 1);
614 static const struct btf_var *btf_type_var(const struct btf_type *t)
616 return (const struct btf_var *)(t + 1);
619 static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t)
621 return kind_ops[BTF_INFO_KIND(t->info)];
624 static bool btf_name_offset_valid(const struct btf *btf, u32 offset)
626 if (!BTF_STR_OFFSET_VALID(offset))
629 while (offset < btf->start_str_off)
632 offset -= btf->start_str_off;
633 return offset < btf->hdr.str_len;
636 static bool __btf_name_char_ok(char c, bool first, bool dot_ok)
638 if ((first ? !isalpha(c) :
641 ((c == '.' && !dot_ok) ||
647 static const char *btf_str_by_offset(const struct btf *btf, u32 offset)
649 while (offset < btf->start_str_off)
652 offset -= btf->start_str_off;
653 if (offset < btf->hdr.str_len)
654 return &btf->strings[offset];
659 static bool __btf_name_valid(const struct btf *btf, u32 offset, bool dot_ok)
661 /* offset must be valid */
662 const char *src = btf_str_by_offset(btf, offset);
663 const char *src_limit;
665 if (!__btf_name_char_ok(*src, true, dot_ok))
668 /* set a limit on identifier length */
669 src_limit = src + KSYM_NAME_LEN;
671 while (*src && src < src_limit) {
672 if (!__btf_name_char_ok(*src, false, dot_ok))
680 /* Only C-style identifier is permitted. This can be relaxed if
683 static bool btf_name_valid_identifier(const struct btf *btf, u32 offset)
685 return __btf_name_valid(btf, offset, false);
688 static bool btf_name_valid_section(const struct btf *btf, u32 offset)
690 return __btf_name_valid(btf, offset, true);
693 static const char *__btf_name_by_offset(const struct btf *btf, u32 offset)
700 name = btf_str_by_offset(btf, offset);
701 return name ?: "(invalid-name-offset)";
704 const char *btf_name_by_offset(const struct btf *btf, u32 offset)
706 return btf_str_by_offset(btf, offset);
709 const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id)
711 while (type_id < btf->start_id)
714 type_id -= btf->start_id;
715 if (type_id >= btf->nr_types)
717 return btf->types[type_id];
721 * Regular int is not a bit field and it must be either
722 * u8/u16/u32/u64 or __int128.
724 static bool btf_type_int_is_regular(const struct btf_type *t)
726 u8 nr_bits, nr_bytes;
729 int_data = btf_type_int(t);
730 nr_bits = BTF_INT_BITS(int_data);
731 nr_bytes = BITS_ROUNDUP_BYTES(nr_bits);
732 if (BITS_PER_BYTE_MASKED(nr_bits) ||
733 BTF_INT_OFFSET(int_data) ||
734 (nr_bytes != sizeof(u8) && nr_bytes != sizeof(u16) &&
735 nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64) &&
736 nr_bytes != (2 * sizeof(u64)))) {
744 * Check that given struct member is a regular int with expected
747 bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
748 const struct btf_member *m,
749 u32 expected_offset, u32 expected_size)
751 const struct btf_type *t;
756 t = btf_type_id_size(btf, &id, NULL);
757 if (!t || !btf_type_is_int(t))
760 int_data = btf_type_int(t);
761 nr_bits = BTF_INT_BITS(int_data);
762 if (btf_type_kflag(s)) {
763 u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset);
764 u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset);
766 /* if kflag set, int should be a regular int and
767 * bit offset should be at byte boundary.
769 return !bitfield_size &&
770 BITS_ROUNDUP_BYTES(bit_offset) == expected_offset &&
771 BITS_ROUNDUP_BYTES(nr_bits) == expected_size;
774 if (BTF_INT_OFFSET(int_data) ||
775 BITS_PER_BYTE_MASKED(m->offset) ||
776 BITS_ROUNDUP_BYTES(m->offset) != expected_offset ||
777 BITS_PER_BYTE_MASKED(nr_bits) ||
778 BITS_ROUNDUP_BYTES(nr_bits) != expected_size)
784 /* Similar to btf_type_skip_modifiers() but does not skip typedefs. */
785 static const struct btf_type *btf_type_skip_qualifiers(const struct btf *btf,
788 const struct btf_type *t = btf_type_by_id(btf, id);
790 while (btf_type_is_modifier(t) &&
791 BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF) {
792 t = btf_type_by_id(btf, t->type);
798 #define BTF_SHOW_MAX_ITER 10
800 #define BTF_KIND_BIT(kind) (1ULL << kind)
803 * Populate show->state.name with type name information.
804 * Format of type name is
806 * [.member_name = ] (type_name)
808 static const char *btf_show_name(struct btf_show *show)
810 /* BTF_MAX_ITER array suffixes "[]" */
811 const char *array_suffixes = "[][][][][][][][][][]";
812 const char *array_suffix = &array_suffixes[strlen(array_suffixes)];
813 /* BTF_MAX_ITER pointer suffixes "*" */
814 const char *ptr_suffixes = "**********";
815 const char *ptr_suffix = &ptr_suffixes[strlen(ptr_suffixes)];
816 const char *name = NULL, *prefix = "", *parens = "";
817 const struct btf_member *m = show->state.member;
818 const struct btf_type *t = show->state.type;
819 const struct btf_array *array;
820 u32 id = show->state.type_id;
821 const char *member = NULL;
822 bool show_member = false;
826 show->state.name[0] = '\0';
829 * Don't show type name if we're showing an array member;
830 * in that case we show the array type so don't need to repeat
831 * ourselves for each member.
833 if (show->state.array_member)
836 /* Retrieve member name, if any. */
838 member = btf_name_by_offset(show->btf, m->name_off);
839 show_member = strlen(member) > 0;
844 * Start with type_id, as we have resolved the struct btf_type *
845 * via btf_modifier_show() past the parent typedef to the child
846 * struct, int etc it is defined as. In such cases, the type_id
847 * still represents the starting type while the struct btf_type *
848 * in our show->state points at the resolved type of the typedef.
850 t = btf_type_by_id(show->btf, id);
855 * The goal here is to build up the right number of pointer and
856 * array suffixes while ensuring the type name for a typedef
857 * is represented. Along the way we accumulate a list of
858 * BTF kinds we have encountered, since these will inform later
859 * display; for example, pointer types will not require an
860 * opening "{" for struct, we will just display the pointer value.
862 * We also want to accumulate the right number of pointer or array
863 * indices in the format string while iterating until we get to
864 * the typedef/pointee/array member target type.
866 * We start by pointing at the end of pointer and array suffix
867 * strings; as we accumulate pointers and arrays we move the pointer
868 * or array string backwards so it will show the expected number of
869 * '*' or '[]' for the type. BTF_SHOW_MAX_ITER of nesting of pointers
870 * and/or arrays and typedefs are supported as a precaution.
872 * We also want to get typedef name while proceeding to resolve
873 * type it points to so that we can add parentheses if it is a
874 * "typedef struct" etc.
876 for (i = 0; i < BTF_SHOW_MAX_ITER; i++) {
878 switch (BTF_INFO_KIND(t->info)) {
879 case BTF_KIND_TYPEDEF:
881 name = btf_name_by_offset(show->btf,
883 kinds |= BTF_KIND_BIT(BTF_KIND_TYPEDEF);
887 kinds |= BTF_KIND_BIT(BTF_KIND_ARRAY);
891 array = btf_type_array(t);
892 if (array_suffix > array_suffixes)
897 kinds |= BTF_KIND_BIT(BTF_KIND_PTR);
898 if (ptr_suffix > ptr_suffixes)
908 t = btf_type_skip_qualifiers(show->btf, id);
910 /* We may not be able to represent this type; bail to be safe */
911 if (i == BTF_SHOW_MAX_ITER)
915 name = btf_name_by_offset(show->btf, t->name_off);
917 switch (BTF_INFO_KIND(t->info)) {
918 case BTF_KIND_STRUCT:
920 prefix = BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT ?
922 /* if it's an array of struct/union, parens is already set */
923 if (!(kinds & (BTF_KIND_BIT(BTF_KIND_ARRAY))))
933 /* pointer does not require parens */
934 if (kinds & BTF_KIND_BIT(BTF_KIND_PTR))
936 /* typedef does not require struct/union/enum prefix */
937 if (kinds & BTF_KIND_BIT(BTF_KIND_TYPEDEF))
943 /* Even if we don't want type name info, we want parentheses etc */
944 if (show->flags & BTF_SHOW_NONAME)
945 snprintf(show->state.name, sizeof(show->state.name), "%s",
948 snprintf(show->state.name, sizeof(show->state.name),
949 "%s%s%s(%s%s%s%s%s%s)%s",
950 /* first 3 strings comprise ".member = " */
951 show_member ? "." : "",
952 show_member ? member : "",
953 show_member ? " = " : "",
954 /* ...next is our prefix (struct, enum, etc) */
956 strlen(prefix) > 0 && strlen(name) > 0 ? " " : "",
957 /* ...this is the type name itself */
959 /* ...suffixed by the appropriate '*', '[]' suffixes */
960 strlen(ptr_suffix) > 0 ? " " : "", ptr_suffix,
961 array_suffix, parens);
963 return show->state.name;
966 static const char *__btf_show_indent(struct btf_show *show)
968 const char *indents = " ";
969 const char *indent = &indents[strlen(indents)];
971 if ((indent - show->state.depth) >= indents)
972 return indent - show->state.depth;
976 static const char *btf_show_indent(struct btf_show *show)
978 return show->flags & BTF_SHOW_COMPACT ? "" : __btf_show_indent(show);
981 static const char *btf_show_newline(struct btf_show *show)
983 return show->flags & BTF_SHOW_COMPACT ? "" : "\n";
986 static const char *btf_show_delim(struct btf_show *show)
988 if (show->state.depth == 0)
991 if ((show->flags & BTF_SHOW_COMPACT) && show->state.type &&
992 BTF_INFO_KIND(show->state.type->info) == BTF_KIND_UNION)
998 __printf(2, 3) static void btf_show(struct btf_show *show, const char *fmt, ...)
1002 if (!show->state.depth_check) {
1003 va_start(args, fmt);
1004 show->showfn(show, fmt, args);
1009 /* Macros are used here as btf_show_type_value[s]() prepends and appends
1010 * format specifiers to the format specifier passed in; these do the work of
1011 * adding indentation, delimiters etc while the caller simply has to specify
1012 * the type value(s) in the format specifier + value(s).
1014 #define btf_show_type_value(show, fmt, value) \
1016 if ((value) != 0 || (show->flags & BTF_SHOW_ZERO) || \
1017 show->state.depth == 0) { \
1018 btf_show(show, "%s%s" fmt "%s%s", \
1019 btf_show_indent(show), \
1020 btf_show_name(show), \
1021 value, btf_show_delim(show), \
1022 btf_show_newline(show)); \
1023 if (show->state.depth > show->state.depth_to_show) \
1024 show->state.depth_to_show = show->state.depth; \
1028 #define btf_show_type_values(show, fmt, ...) \
1030 btf_show(show, "%s%s" fmt "%s%s", btf_show_indent(show), \
1031 btf_show_name(show), \
1032 __VA_ARGS__, btf_show_delim(show), \
1033 btf_show_newline(show)); \
1034 if (show->state.depth > show->state.depth_to_show) \
1035 show->state.depth_to_show = show->state.depth; \
1038 /* How much is left to copy to safe buffer after @data? */
1039 static int btf_show_obj_size_left(struct btf_show *show, void *data)
1041 return show->obj.head + show->obj.size - data;
1044 /* Is object pointed to by @data of @size already copied to our safe buffer? */
1045 static bool btf_show_obj_is_safe(struct btf_show *show, void *data, int size)
1047 return data >= show->obj.data &&
1048 (data + size) < (show->obj.data + BTF_SHOW_OBJ_SAFE_SIZE);
1052 * If object pointed to by @data of @size falls within our safe buffer, return
1053 * the equivalent pointer to the same safe data. Assumes
1054 * copy_from_kernel_nofault() has already happened and our safe buffer is
1057 static void *__btf_show_obj_safe(struct btf_show *show, void *data, int size)
1059 if (btf_show_obj_is_safe(show, data, size))
1060 return show->obj.safe + (data - show->obj.data);
1065 * Return a safe-to-access version of data pointed to by @data.
1066 * We do this by copying the relevant amount of information
1067 * to the struct btf_show obj.safe buffer using copy_from_kernel_nofault().
1069 * If BTF_SHOW_UNSAFE is specified, just return data as-is; no
1070 * safe copy is needed.
1072 * Otherwise we need to determine if we have the required amount
1073 * of data (determined by the @data pointer and the size of the
1074 * largest base type we can encounter (represented by
1075 * BTF_SHOW_OBJ_BASE_TYPE_SIZE). Having that much data ensures
1076 * that we will be able to print some of the current object,
1077 * and if more is needed a copy will be triggered.
1078 * Some objects such as structs will not fit into the buffer;
1079 * in such cases additional copies when we iterate over their
1080 * members may be needed.
1082 * btf_show_obj_safe() is used to return a safe buffer for
1083 * btf_show_start_type(); this ensures that as we recurse into
1084 * nested types we always have safe data for the given type.
1085 * This approach is somewhat wasteful; it's possible for example
1086 * that when iterating over a large union we'll end up copying the
1087 * same data repeatedly, but the goal is safety not performance.
1088 * We use stack data as opposed to per-CPU buffers because the
1089 * iteration over a type can take some time, and preemption handling
1090 * would greatly complicate use of the safe buffer.
1092 static void *btf_show_obj_safe(struct btf_show *show,
1093 const struct btf_type *t,
1096 const struct btf_type *rt;
1097 int size_left, size;
1100 if (show->flags & BTF_SHOW_UNSAFE)
1103 rt = btf_resolve_size(show->btf, t, &size);
1105 show->state.status = PTR_ERR(rt);
1110 * Is this toplevel object? If so, set total object size and
1111 * initialize pointers. Otherwise check if we still fall within
1112 * our safe object data.
1114 if (show->state.depth == 0) {
1115 show->obj.size = size;
1116 show->obj.head = data;
1119 * If the size of the current object is > our remaining
1120 * safe buffer we _may_ need to do a new copy. However
1121 * consider the case of a nested struct; it's size pushes
1122 * us over the safe buffer limit, but showing any individual
1123 * struct members does not. In such cases, we don't need
1124 * to initiate a fresh copy yet; however we definitely need
1125 * at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes left
1126 * in our buffer, regardless of the current object size.
1127 * The logic here is that as we resolve types we will
1128 * hit a base type at some point, and we need to be sure
1129 * the next chunk of data is safely available to display
1130 * that type info safely. We cannot rely on the size of
1131 * the current object here because it may be much larger
1132 * than our current buffer (e.g. task_struct is 8k).
1133 * All we want to do here is ensure that we can print the
1134 * next basic type, which we can if either
1135 * - the current type size is within the safe buffer; or
1136 * - at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes are left in
1139 safe = __btf_show_obj_safe(show, data,
1141 BTF_SHOW_OBJ_BASE_TYPE_SIZE));
1145 * We need a new copy to our safe object, either because we haven't
1146 * yet copied and are initializing safe data, or because the data
1147 * we want falls outside the boundaries of the safe object.
1150 size_left = btf_show_obj_size_left(show, data);
1151 if (size_left > BTF_SHOW_OBJ_SAFE_SIZE)
1152 size_left = BTF_SHOW_OBJ_SAFE_SIZE;
1153 show->state.status = copy_from_kernel_nofault(show->obj.safe,
1155 if (!show->state.status) {
1156 show->obj.data = data;
1157 safe = show->obj.safe;
1165 * Set the type we are starting to show and return a safe data pointer
1166 * to be used for showing the associated data.
1168 static void *btf_show_start_type(struct btf_show *show,
1169 const struct btf_type *t,
1170 u32 type_id, void *data)
1172 show->state.type = t;
1173 show->state.type_id = type_id;
1174 show->state.name[0] = '\0';
1176 return btf_show_obj_safe(show, t, data);
1179 static void btf_show_end_type(struct btf_show *show)
1181 show->state.type = NULL;
1182 show->state.type_id = 0;
1183 show->state.name[0] = '\0';
1186 static void *btf_show_start_aggr_type(struct btf_show *show,
1187 const struct btf_type *t,
1188 u32 type_id, void *data)
1190 void *safe_data = btf_show_start_type(show, t, type_id, data);
1195 btf_show(show, "%s%s%s", btf_show_indent(show),
1196 btf_show_name(show),
1197 btf_show_newline(show));
1198 show->state.depth++;
1202 static void btf_show_end_aggr_type(struct btf_show *show,
1205 show->state.depth--;
1206 btf_show(show, "%s%s%s%s", btf_show_indent(show), suffix,
1207 btf_show_delim(show), btf_show_newline(show));
1208 btf_show_end_type(show);
1211 static void btf_show_start_member(struct btf_show *show,
1212 const struct btf_member *m)
1214 show->state.member = m;
1217 static void btf_show_start_array_member(struct btf_show *show)
1219 show->state.array_member = 1;
1220 btf_show_start_member(show, NULL);
1223 static void btf_show_end_member(struct btf_show *show)
1225 show->state.member = NULL;
1228 static void btf_show_end_array_member(struct btf_show *show)
1230 show->state.array_member = 0;
1231 btf_show_end_member(show);
1234 static void *btf_show_start_array_type(struct btf_show *show,
1235 const struct btf_type *t,
1240 show->state.array_encoding = array_encoding;
1241 show->state.array_terminated = 0;
1242 return btf_show_start_aggr_type(show, t, type_id, data);
1245 static void btf_show_end_array_type(struct btf_show *show)
1247 show->state.array_encoding = 0;
1248 show->state.array_terminated = 0;
1249 btf_show_end_aggr_type(show, "]");
1252 static void *btf_show_start_struct_type(struct btf_show *show,
1253 const struct btf_type *t,
1257 return btf_show_start_aggr_type(show, t, type_id, data);
1260 static void btf_show_end_struct_type(struct btf_show *show)
1262 btf_show_end_aggr_type(show, "}");
1265 __printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log,
1266 const char *fmt, ...)
1270 va_start(args, fmt);
1271 bpf_verifier_vlog(log, fmt, args);
1275 __printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env,
1276 const char *fmt, ...)
1278 struct bpf_verifier_log *log = &env->log;
1281 if (!bpf_verifier_log_needed(log))
1284 va_start(args, fmt);
1285 bpf_verifier_vlog(log, fmt, args);
1289 __printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env,
1290 const struct btf_type *t,
1292 const char *fmt, ...)
1294 struct bpf_verifier_log *log = &env->log;
1295 u8 kind = BTF_INFO_KIND(t->info);
1296 struct btf *btf = env->btf;
1299 if (!bpf_verifier_log_needed(log))
1302 /* btf verifier prints all types it is processing via
1303 * btf_verifier_log_type(..., fmt = NULL).
1304 * Skip those prints for in-kernel BTF verification.
1306 if (log->level == BPF_LOG_KERNEL && !fmt)
1309 __btf_verifier_log(log, "[%u] %s %s%s",
1312 __btf_name_by_offset(btf, t->name_off),
1313 log_details ? " " : "");
1316 btf_type_ops(t)->log_details(env, t);
1319 __btf_verifier_log(log, " ");
1320 va_start(args, fmt);
1321 bpf_verifier_vlog(log, fmt, args);
1325 __btf_verifier_log(log, "\n");
1328 #define btf_verifier_log_type(env, t, ...) \
1329 __btf_verifier_log_type((env), (t), true, __VA_ARGS__)
1330 #define btf_verifier_log_basic(env, t, ...) \
1331 __btf_verifier_log_type((env), (t), false, __VA_ARGS__)
1334 static void btf_verifier_log_member(struct btf_verifier_env *env,
1335 const struct btf_type *struct_type,
1336 const struct btf_member *member,
1337 const char *fmt, ...)
1339 struct bpf_verifier_log *log = &env->log;
1340 struct btf *btf = env->btf;
1343 if (!bpf_verifier_log_needed(log))
1346 if (log->level == BPF_LOG_KERNEL && !fmt)
1348 /* The CHECK_META phase already did a btf dump.
1350 * If member is logged again, it must hit an error in
1351 * parsing this member. It is useful to print out which
1352 * struct this member belongs to.
1354 if (env->phase != CHECK_META)
1355 btf_verifier_log_type(env, struct_type, NULL);
1357 if (btf_type_kflag(struct_type))
1358 __btf_verifier_log(log,
1359 "\t%s type_id=%u bitfield_size=%u bits_offset=%u",
1360 __btf_name_by_offset(btf, member->name_off),
1362 BTF_MEMBER_BITFIELD_SIZE(member->offset),
1363 BTF_MEMBER_BIT_OFFSET(member->offset));
1365 __btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u",
1366 __btf_name_by_offset(btf, member->name_off),
1367 member->type, member->offset);
1370 __btf_verifier_log(log, " ");
1371 va_start(args, fmt);
1372 bpf_verifier_vlog(log, fmt, args);
1376 __btf_verifier_log(log, "\n");
1380 static void btf_verifier_log_vsi(struct btf_verifier_env *env,
1381 const struct btf_type *datasec_type,
1382 const struct btf_var_secinfo *vsi,
1383 const char *fmt, ...)
1385 struct bpf_verifier_log *log = &env->log;
1388 if (!bpf_verifier_log_needed(log))
1390 if (log->level == BPF_LOG_KERNEL && !fmt)
1392 if (env->phase != CHECK_META)
1393 btf_verifier_log_type(env, datasec_type, NULL);
1395 __btf_verifier_log(log, "\t type_id=%u offset=%u size=%u",
1396 vsi->type, vsi->offset, vsi->size);
1398 __btf_verifier_log(log, " ");
1399 va_start(args, fmt);
1400 bpf_verifier_vlog(log, fmt, args);
1404 __btf_verifier_log(log, "\n");
1407 static void btf_verifier_log_hdr(struct btf_verifier_env *env,
1410 struct bpf_verifier_log *log = &env->log;
1411 const struct btf *btf = env->btf;
1412 const struct btf_header *hdr;
1414 if (!bpf_verifier_log_needed(log))
1417 if (log->level == BPF_LOG_KERNEL)
1420 __btf_verifier_log(log, "magic: 0x%x\n", hdr->magic);
1421 __btf_verifier_log(log, "version: %u\n", hdr->version);
1422 __btf_verifier_log(log, "flags: 0x%x\n", hdr->flags);
1423 __btf_verifier_log(log, "hdr_len: %u\n", hdr->hdr_len);
1424 __btf_verifier_log(log, "type_off: %u\n", hdr->type_off);
1425 __btf_verifier_log(log, "type_len: %u\n", hdr->type_len);
1426 __btf_verifier_log(log, "str_off: %u\n", hdr->str_off);
1427 __btf_verifier_log(log, "str_len: %u\n", hdr->str_len);
1428 __btf_verifier_log(log, "btf_total_size: %u\n", btf_data_size);
1431 static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t)
1433 struct btf *btf = env->btf;
1435 if (btf->types_size == btf->nr_types) {
1436 /* Expand 'types' array */
1438 struct btf_type **new_types;
1439 u32 expand_by, new_size;
1441 if (btf->start_id + btf->types_size == BTF_MAX_TYPE) {
1442 btf_verifier_log(env, "Exceeded max num of types");
1446 expand_by = max_t(u32, btf->types_size >> 2, 16);
1447 new_size = min_t(u32, BTF_MAX_TYPE,
1448 btf->types_size + expand_by);
1450 new_types = kvcalloc(new_size, sizeof(*new_types),
1451 GFP_KERNEL | __GFP_NOWARN);
1455 if (btf->nr_types == 0) {
1456 if (!btf->base_btf) {
1457 /* lazily init VOID type */
1458 new_types[0] = &btf_void;
1462 memcpy(new_types, btf->types,
1463 sizeof(*btf->types) * btf->nr_types);
1467 btf->types = new_types;
1468 btf->types_size = new_size;
1471 btf->types[btf->nr_types++] = t;
1476 static int btf_alloc_id(struct btf *btf)
1480 idr_preload(GFP_KERNEL);
1481 spin_lock_bh(&btf_idr_lock);
1482 id = idr_alloc_cyclic(&btf_idr, btf, 1, INT_MAX, GFP_ATOMIC);
1485 spin_unlock_bh(&btf_idr_lock);
1488 if (WARN_ON_ONCE(!id))
1491 return id > 0 ? 0 : id;
1494 static void btf_free_id(struct btf *btf)
1496 unsigned long flags;
1499 * In map-in-map, calling map_delete_elem() on outer
1500 * map will call bpf_map_put on the inner map.
1501 * It will then eventually call btf_free_id()
1502 * on the inner map. Some of the map_delete_elem()
1503 * implementation may have irq disabled, so
1504 * we need to use the _irqsave() version instead
1505 * of the _bh() version.
1507 spin_lock_irqsave(&btf_idr_lock, flags);
1508 idr_remove(&btf_idr, btf->id);
1509 spin_unlock_irqrestore(&btf_idr_lock, flags);
1512 static void btf_free(struct btf *btf)
1515 kvfree(btf->resolved_sizes);
1516 kvfree(btf->resolved_ids);
1521 static void btf_free_rcu(struct rcu_head *rcu)
1523 struct btf *btf = container_of(rcu, struct btf, rcu);
1528 void btf_get(struct btf *btf)
1530 refcount_inc(&btf->refcnt);
1533 void btf_put(struct btf *btf)
1535 if (btf && refcount_dec_and_test(&btf->refcnt)) {
1537 call_rcu(&btf->rcu, btf_free_rcu);
1541 static int env_resolve_init(struct btf_verifier_env *env)
1543 struct btf *btf = env->btf;
1544 u32 nr_types = btf->nr_types;
1545 u32 *resolved_sizes = NULL;
1546 u32 *resolved_ids = NULL;
1547 u8 *visit_states = NULL;
1549 resolved_sizes = kvcalloc(nr_types, sizeof(*resolved_sizes),
1550 GFP_KERNEL | __GFP_NOWARN);
1551 if (!resolved_sizes)
1554 resolved_ids = kvcalloc(nr_types, sizeof(*resolved_ids),
1555 GFP_KERNEL | __GFP_NOWARN);
1559 visit_states = kvcalloc(nr_types, sizeof(*visit_states),
1560 GFP_KERNEL | __GFP_NOWARN);
1564 btf->resolved_sizes = resolved_sizes;
1565 btf->resolved_ids = resolved_ids;
1566 env->visit_states = visit_states;
1571 kvfree(resolved_sizes);
1572 kvfree(resolved_ids);
1573 kvfree(visit_states);
1577 static void btf_verifier_env_free(struct btf_verifier_env *env)
1579 kvfree(env->visit_states);
1583 static bool env_type_is_resolve_sink(const struct btf_verifier_env *env,
1584 const struct btf_type *next_type)
1586 switch (env->resolve_mode) {
1588 /* int, enum or void is a sink */
1589 return !btf_type_needs_resolve(next_type);
1591 /* int, enum, void, struct, array, func or func_proto is a sink
1594 return !btf_type_is_modifier(next_type) &&
1595 !btf_type_is_ptr(next_type);
1596 case RESOLVE_STRUCT_OR_ARRAY:
1597 /* int, enum, void, ptr, func or func_proto is a sink
1598 * for struct and array
1600 return !btf_type_is_modifier(next_type) &&
1601 !btf_type_is_array(next_type) &&
1602 !btf_type_is_struct(next_type);
1608 static bool env_type_is_resolved(const struct btf_verifier_env *env,
1611 /* base BTF types should be resolved by now */
1612 if (type_id < env->btf->start_id)
1615 return env->visit_states[type_id - env->btf->start_id] == RESOLVED;
1618 static int env_stack_push(struct btf_verifier_env *env,
1619 const struct btf_type *t, u32 type_id)
1621 const struct btf *btf = env->btf;
1622 struct resolve_vertex *v;
1624 if (env->top_stack == MAX_RESOLVE_DEPTH)
1627 if (type_id < btf->start_id
1628 || env->visit_states[type_id - btf->start_id] != NOT_VISITED)
1631 env->visit_states[type_id - btf->start_id] = VISITED;
1633 v = &env->stack[env->top_stack++];
1635 v->type_id = type_id;
1638 if (env->resolve_mode == RESOLVE_TBD) {
1639 if (btf_type_is_ptr(t))
1640 env->resolve_mode = RESOLVE_PTR;
1641 else if (btf_type_is_struct(t) || btf_type_is_array(t))
1642 env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY;
1648 static void env_stack_set_next_member(struct btf_verifier_env *env,
1651 env->stack[env->top_stack - 1].next_member = next_member;
1654 static void env_stack_pop_resolved(struct btf_verifier_env *env,
1655 u32 resolved_type_id,
1658 u32 type_id = env->stack[--(env->top_stack)].type_id;
1659 struct btf *btf = env->btf;
1661 type_id -= btf->start_id; /* adjust to local type id */
1662 btf->resolved_sizes[type_id] = resolved_size;
1663 btf->resolved_ids[type_id] = resolved_type_id;
1664 env->visit_states[type_id] = RESOLVED;
1667 static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env)
1669 return env->top_stack ? &env->stack[env->top_stack - 1] : NULL;
1672 /* Resolve the size of a passed-in "type"
1674 * type: is an array (e.g. u32 array[x][y])
1675 * return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY,
1676 * *type_size: (x * y * sizeof(u32)). Hence, *type_size always
1677 * corresponds to the return type.
1679 * *elem_id: id of u32
1680 * *total_nelems: (x * y). Hence, individual elem size is
1681 * (*type_size / *total_nelems)
1682 * *type_id: id of type if it's changed within the function, 0 if not
1684 * type: is not an array (e.g. const struct X)
1685 * return type: type "struct X"
1686 * *type_size: sizeof(struct X)
1687 * *elem_type: same as return type ("struct X")
1690 * *type_id: id of type if it's changed within the function, 0 if not
1692 static const struct btf_type *
1693 __btf_resolve_size(const struct btf *btf, const struct btf_type *type,
1694 u32 *type_size, const struct btf_type **elem_type,
1695 u32 *elem_id, u32 *total_nelems, u32 *type_id)
1697 const struct btf_type *array_type = NULL;
1698 const struct btf_array *array = NULL;
1699 u32 i, size, nelems = 1, id = 0;
1701 for (i = 0; i < MAX_RESOLVE_DEPTH; i++) {
1702 switch (BTF_INFO_KIND(type->info)) {
1703 /* type->size can be used */
1705 case BTF_KIND_STRUCT:
1706 case BTF_KIND_UNION:
1708 case BTF_KIND_FLOAT:
1713 size = sizeof(void *);
1717 case BTF_KIND_TYPEDEF:
1718 case BTF_KIND_VOLATILE:
1719 case BTF_KIND_CONST:
1720 case BTF_KIND_RESTRICT:
1722 type = btf_type_by_id(btf, type->type);
1725 case BTF_KIND_ARRAY:
1728 array = btf_type_array(type);
1729 if (nelems && array->nelems > U32_MAX / nelems)
1730 return ERR_PTR(-EINVAL);
1731 nelems *= array->nelems;
1732 type = btf_type_by_id(btf, array->type);
1735 /* type without size */
1737 return ERR_PTR(-EINVAL);
1741 return ERR_PTR(-EINVAL);
1744 if (nelems && size > U32_MAX / nelems)
1745 return ERR_PTR(-EINVAL);
1747 *type_size = nelems * size;
1749 *total_nelems = nelems;
1753 *elem_id = array ? array->type : 0;
1757 return array_type ? : type;
1760 const struct btf_type *
1761 btf_resolve_size(const struct btf *btf, const struct btf_type *type,
1764 return __btf_resolve_size(btf, type, type_size, NULL, NULL, NULL, NULL);
1767 static u32 btf_resolved_type_id(const struct btf *btf, u32 type_id)
1769 while (type_id < btf->start_id)
1770 btf = btf->base_btf;
1772 return btf->resolved_ids[type_id - btf->start_id];
1775 /* The input param "type_id" must point to a needs_resolve type */
1776 static const struct btf_type *btf_type_id_resolve(const struct btf *btf,
1779 *type_id = btf_resolved_type_id(btf, *type_id);
1780 return btf_type_by_id(btf, *type_id);
1783 static u32 btf_resolved_type_size(const struct btf *btf, u32 type_id)
1785 while (type_id < btf->start_id)
1786 btf = btf->base_btf;
1788 return btf->resolved_sizes[type_id - btf->start_id];
1791 const struct btf_type *btf_type_id_size(const struct btf *btf,
1792 u32 *type_id, u32 *ret_size)
1794 const struct btf_type *size_type;
1795 u32 size_type_id = *type_id;
1798 size_type = btf_type_by_id(btf, size_type_id);
1799 if (btf_type_nosize_or_null(size_type))
1802 if (btf_type_has_size(size_type)) {
1803 size = size_type->size;
1804 } else if (btf_type_is_array(size_type)) {
1805 size = btf_resolved_type_size(btf, size_type_id);
1806 } else if (btf_type_is_ptr(size_type)) {
1807 size = sizeof(void *);
1809 if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) &&
1810 !btf_type_is_var(size_type)))
1813 size_type_id = btf_resolved_type_id(btf, size_type_id);
1814 size_type = btf_type_by_id(btf, size_type_id);
1815 if (btf_type_nosize_or_null(size_type))
1817 else if (btf_type_has_size(size_type))
1818 size = size_type->size;
1819 else if (btf_type_is_array(size_type))
1820 size = btf_resolved_type_size(btf, size_type_id);
1821 else if (btf_type_is_ptr(size_type))
1822 size = sizeof(void *);
1827 *type_id = size_type_id;
1834 static int btf_df_check_member(struct btf_verifier_env *env,
1835 const struct btf_type *struct_type,
1836 const struct btf_member *member,
1837 const struct btf_type *member_type)
1839 btf_verifier_log_basic(env, struct_type,
1840 "Unsupported check_member");
1844 static int btf_df_check_kflag_member(struct btf_verifier_env *env,
1845 const struct btf_type *struct_type,
1846 const struct btf_member *member,
1847 const struct btf_type *member_type)
1849 btf_verifier_log_basic(env, struct_type,
1850 "Unsupported check_kflag_member");
1854 /* Used for ptr, array struct/union and float type members.
1855 * int, enum and modifier types have their specific callback functions.
1857 static int btf_generic_check_kflag_member(struct btf_verifier_env *env,
1858 const struct btf_type *struct_type,
1859 const struct btf_member *member,
1860 const struct btf_type *member_type)
1862 if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) {
1863 btf_verifier_log_member(env, struct_type, member,
1864 "Invalid member bitfield_size");
1868 /* bitfield size is 0, so member->offset represents bit offset only.
1869 * It is safe to call non kflag check_member variants.
1871 return btf_type_ops(member_type)->check_member(env, struct_type,
1876 static int btf_df_resolve(struct btf_verifier_env *env,
1877 const struct resolve_vertex *v)
1879 btf_verifier_log_basic(env, v->t, "Unsupported resolve");
1883 static void btf_df_show(const struct btf *btf, const struct btf_type *t,
1884 u32 type_id, void *data, u8 bits_offsets,
1885 struct btf_show *show)
1887 btf_show(show, "<unsupported kind:%u>", BTF_INFO_KIND(t->info));
1890 static int btf_int_check_member(struct btf_verifier_env *env,
1891 const struct btf_type *struct_type,
1892 const struct btf_member *member,
1893 const struct btf_type *member_type)
1895 u32 int_data = btf_type_int(member_type);
1896 u32 struct_bits_off = member->offset;
1897 u32 struct_size = struct_type->size;
1901 if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) {
1902 btf_verifier_log_member(env, struct_type, member,
1903 "bits_offset exceeds U32_MAX");
1907 struct_bits_off += BTF_INT_OFFSET(int_data);
1908 bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
1909 nr_copy_bits = BTF_INT_BITS(int_data) +
1910 BITS_PER_BYTE_MASKED(struct_bits_off);
1912 if (nr_copy_bits > BITS_PER_U128) {
1913 btf_verifier_log_member(env, struct_type, member,
1914 "nr_copy_bits exceeds 128");
1918 if (struct_size < bytes_offset ||
1919 struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) {
1920 btf_verifier_log_member(env, struct_type, member,
1921 "Member exceeds struct_size");
1928 static int btf_int_check_kflag_member(struct btf_verifier_env *env,
1929 const struct btf_type *struct_type,
1930 const struct btf_member *member,
1931 const struct btf_type *member_type)
1933 u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset;
1934 u32 int_data = btf_type_int(member_type);
1935 u32 struct_size = struct_type->size;
1938 /* a regular int type is required for the kflag int member */
1939 if (!btf_type_int_is_regular(member_type)) {
1940 btf_verifier_log_member(env, struct_type, member,
1941 "Invalid member base type");
1945 /* check sanity of bitfield size */
1946 nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset);
1947 struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset);
1948 nr_int_data_bits = BTF_INT_BITS(int_data);
1950 /* Not a bitfield member, member offset must be at byte
1953 if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
1954 btf_verifier_log_member(env, struct_type, member,
1955 "Invalid member offset");
1959 nr_bits = nr_int_data_bits;
1960 } else if (nr_bits > nr_int_data_bits) {
1961 btf_verifier_log_member(env, struct_type, member,
1962 "Invalid member bitfield_size");
1966 bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
1967 nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off);
1968 if (nr_copy_bits > BITS_PER_U128) {
1969 btf_verifier_log_member(env, struct_type, member,
1970 "nr_copy_bits exceeds 128");
1974 if (struct_size < bytes_offset ||
1975 struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) {
1976 btf_verifier_log_member(env, struct_type, member,
1977 "Member exceeds struct_size");
1984 static s32 btf_int_check_meta(struct btf_verifier_env *env,
1985 const struct btf_type *t,
1988 u32 int_data, nr_bits, meta_needed = sizeof(int_data);
1991 if (meta_left < meta_needed) {
1992 btf_verifier_log_basic(env, t,
1993 "meta_left:%u meta_needed:%u",
1994 meta_left, meta_needed);
1998 if (btf_type_vlen(t)) {
1999 btf_verifier_log_type(env, t, "vlen != 0");
2003 if (btf_type_kflag(t)) {
2004 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
2008 int_data = btf_type_int(t);
2009 if (int_data & ~BTF_INT_MASK) {
2010 btf_verifier_log_basic(env, t, "Invalid int_data:%x",
2015 nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data);
2017 if (nr_bits > BITS_PER_U128) {
2018 btf_verifier_log_type(env, t, "nr_bits exceeds %zu",
2023 if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) {
2024 btf_verifier_log_type(env, t, "nr_bits exceeds type_size");
2029 * Only one of the encoding bits is allowed and it
2030 * should be sufficient for the pretty print purpose (i.e. decoding).
2031 * Multiple bits can be allowed later if it is found
2032 * to be insufficient.
2034 encoding = BTF_INT_ENCODING(int_data);
2036 encoding != BTF_INT_SIGNED &&
2037 encoding != BTF_INT_CHAR &&
2038 encoding != BTF_INT_BOOL) {
2039 btf_verifier_log_type(env, t, "Unsupported encoding");
2043 btf_verifier_log_type(env, t, NULL);
2048 static void btf_int_log(struct btf_verifier_env *env,
2049 const struct btf_type *t)
2051 int int_data = btf_type_int(t);
2053 btf_verifier_log(env,
2054 "size=%u bits_offset=%u nr_bits=%u encoding=%s",
2055 t->size, BTF_INT_OFFSET(int_data),
2056 BTF_INT_BITS(int_data),
2057 btf_int_encoding_str(BTF_INT_ENCODING(int_data)));
2060 static void btf_int128_print(struct btf_show *show, void *data)
2062 /* data points to a __int128 number.
2064 * int128_num = *(__int128 *)data;
2065 * The below formulas shows what upper_num and lower_num represents:
2066 * upper_num = int128_num >> 64;
2067 * lower_num = int128_num & 0xffffffffFFFFFFFFULL;
2069 u64 upper_num, lower_num;
2071 #ifdef __BIG_ENDIAN_BITFIELD
2072 upper_num = *(u64 *)data;
2073 lower_num = *(u64 *)(data + 8);
2075 upper_num = *(u64 *)(data + 8);
2076 lower_num = *(u64 *)data;
2079 btf_show_type_value(show, "0x%llx", lower_num);
2081 btf_show_type_values(show, "0x%llx%016llx", upper_num,
2085 static void btf_int128_shift(u64 *print_num, u16 left_shift_bits,
2086 u16 right_shift_bits)
2088 u64 upper_num, lower_num;
2090 #ifdef __BIG_ENDIAN_BITFIELD
2091 upper_num = print_num[0];
2092 lower_num = print_num[1];
2094 upper_num = print_num[1];
2095 lower_num = print_num[0];
2098 /* shake out un-needed bits by shift/or operations */
2099 if (left_shift_bits >= 64) {
2100 upper_num = lower_num << (left_shift_bits - 64);
2103 upper_num = (upper_num << left_shift_bits) |
2104 (lower_num >> (64 - left_shift_bits));
2105 lower_num = lower_num << left_shift_bits;
2108 if (right_shift_bits >= 64) {
2109 lower_num = upper_num >> (right_shift_bits - 64);
2112 lower_num = (lower_num >> right_shift_bits) |
2113 (upper_num << (64 - right_shift_bits));
2114 upper_num = upper_num >> right_shift_bits;
2117 #ifdef __BIG_ENDIAN_BITFIELD
2118 print_num[0] = upper_num;
2119 print_num[1] = lower_num;
2121 print_num[0] = lower_num;
2122 print_num[1] = upper_num;
2126 static void btf_bitfield_show(void *data, u8 bits_offset,
2127 u8 nr_bits, struct btf_show *show)
2129 u16 left_shift_bits, right_shift_bits;
2132 u64 print_num[2] = {};
2134 nr_copy_bits = nr_bits + bits_offset;
2135 nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits);
2137 memcpy(print_num, data, nr_copy_bytes);
2139 #ifdef __BIG_ENDIAN_BITFIELD
2140 left_shift_bits = bits_offset;
2142 left_shift_bits = BITS_PER_U128 - nr_copy_bits;
2144 right_shift_bits = BITS_PER_U128 - nr_bits;
2146 btf_int128_shift(print_num, left_shift_bits, right_shift_bits);
2147 btf_int128_print(show, print_num);
2151 static void btf_int_bits_show(const struct btf *btf,
2152 const struct btf_type *t,
2153 void *data, u8 bits_offset,
2154 struct btf_show *show)
2156 u32 int_data = btf_type_int(t);
2157 u8 nr_bits = BTF_INT_BITS(int_data);
2158 u8 total_bits_offset;
2161 * bits_offset is at most 7.
2162 * BTF_INT_OFFSET() cannot exceed 128 bits.
2164 total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data);
2165 data += BITS_ROUNDDOWN_BYTES(total_bits_offset);
2166 bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset);
2167 btf_bitfield_show(data, bits_offset, nr_bits, show);
2170 static void btf_int_show(const struct btf *btf, const struct btf_type *t,
2171 u32 type_id, void *data, u8 bits_offset,
2172 struct btf_show *show)
2174 u32 int_data = btf_type_int(t);
2175 u8 encoding = BTF_INT_ENCODING(int_data);
2176 bool sign = encoding & BTF_INT_SIGNED;
2177 u8 nr_bits = BTF_INT_BITS(int_data);
2180 safe_data = btf_show_start_type(show, t, type_id, data);
2184 if (bits_offset || BTF_INT_OFFSET(int_data) ||
2185 BITS_PER_BYTE_MASKED(nr_bits)) {
2186 btf_int_bits_show(btf, t, safe_data, bits_offset, show);
2192 btf_int128_print(show, safe_data);
2196 btf_show_type_value(show, "%lld", *(s64 *)safe_data);
2198 btf_show_type_value(show, "%llu", *(u64 *)safe_data);
2202 btf_show_type_value(show, "%d", *(s32 *)safe_data);
2204 btf_show_type_value(show, "%u", *(u32 *)safe_data);
2208 btf_show_type_value(show, "%d", *(s16 *)safe_data);
2210 btf_show_type_value(show, "%u", *(u16 *)safe_data);
2213 if (show->state.array_encoding == BTF_INT_CHAR) {
2214 /* check for null terminator */
2215 if (show->state.array_terminated)
2217 if (*(char *)data == '\0') {
2218 show->state.array_terminated = 1;
2221 if (isprint(*(char *)data)) {
2222 btf_show_type_value(show, "'%c'",
2223 *(char *)safe_data);
2228 btf_show_type_value(show, "%d", *(s8 *)safe_data);
2230 btf_show_type_value(show, "%u", *(u8 *)safe_data);
2233 btf_int_bits_show(btf, t, safe_data, bits_offset, show);
2237 btf_show_end_type(show);
2240 static const struct btf_kind_operations int_ops = {
2241 .check_meta = btf_int_check_meta,
2242 .resolve = btf_df_resolve,
2243 .check_member = btf_int_check_member,
2244 .check_kflag_member = btf_int_check_kflag_member,
2245 .log_details = btf_int_log,
2246 .show = btf_int_show,
2249 static int btf_modifier_check_member(struct btf_verifier_env *env,
2250 const struct btf_type *struct_type,
2251 const struct btf_member *member,
2252 const struct btf_type *member_type)
2254 const struct btf_type *resolved_type;
2255 u32 resolved_type_id = member->type;
2256 struct btf_member resolved_member;
2257 struct btf *btf = env->btf;
2259 resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL);
2260 if (!resolved_type) {
2261 btf_verifier_log_member(env, struct_type, member,
2266 resolved_member = *member;
2267 resolved_member.type = resolved_type_id;
2269 return btf_type_ops(resolved_type)->check_member(env, struct_type,
2274 static int btf_modifier_check_kflag_member(struct btf_verifier_env *env,
2275 const struct btf_type *struct_type,
2276 const struct btf_member *member,
2277 const struct btf_type *member_type)
2279 const struct btf_type *resolved_type;
2280 u32 resolved_type_id = member->type;
2281 struct btf_member resolved_member;
2282 struct btf *btf = env->btf;
2284 resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL);
2285 if (!resolved_type) {
2286 btf_verifier_log_member(env, struct_type, member,
2291 resolved_member = *member;
2292 resolved_member.type = resolved_type_id;
2294 return btf_type_ops(resolved_type)->check_kflag_member(env, struct_type,
2299 static int btf_ptr_check_member(struct btf_verifier_env *env,
2300 const struct btf_type *struct_type,
2301 const struct btf_member *member,
2302 const struct btf_type *member_type)
2304 u32 struct_size, struct_bits_off, bytes_offset;
2306 struct_size = struct_type->size;
2307 struct_bits_off = member->offset;
2308 bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
2310 if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
2311 btf_verifier_log_member(env, struct_type, member,
2312 "Member is not byte aligned");
2316 if (struct_size - bytes_offset < sizeof(void *)) {
2317 btf_verifier_log_member(env, struct_type, member,
2318 "Member exceeds struct_size");
2325 static int btf_ref_type_check_meta(struct btf_verifier_env *env,
2326 const struct btf_type *t,
2329 if (btf_type_vlen(t)) {
2330 btf_verifier_log_type(env, t, "vlen != 0");
2334 if (btf_type_kflag(t)) {
2335 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
2339 if (!BTF_TYPE_ID_VALID(t->type)) {
2340 btf_verifier_log_type(env, t, "Invalid type_id");
2344 /* typedef type must have a valid name, and other ref types,
2345 * volatile, const, restrict, should have a null name.
2347 if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) {
2349 !btf_name_valid_identifier(env->btf, t->name_off)) {
2350 btf_verifier_log_type(env, t, "Invalid name");
2355 btf_verifier_log_type(env, t, "Invalid name");
2360 btf_verifier_log_type(env, t, NULL);
2365 static int btf_modifier_resolve(struct btf_verifier_env *env,
2366 const struct resolve_vertex *v)
2368 const struct btf_type *t = v->t;
2369 const struct btf_type *next_type;
2370 u32 next_type_id = t->type;
2371 struct btf *btf = env->btf;
2373 next_type = btf_type_by_id(btf, next_type_id);
2374 if (!next_type || btf_type_is_resolve_source_only(next_type)) {
2375 btf_verifier_log_type(env, v->t, "Invalid type_id");
2379 if (!env_type_is_resolve_sink(env, next_type) &&
2380 !env_type_is_resolved(env, next_type_id))
2381 return env_stack_push(env, next_type, next_type_id);
2383 /* Figure out the resolved next_type_id with size.
2384 * They will be stored in the current modifier's
2385 * resolved_ids and resolved_sizes such that it can
2386 * save us a few type-following when we use it later (e.g. in
2389 if (!btf_type_id_size(btf, &next_type_id, NULL)) {
2390 if (env_type_is_resolved(env, next_type_id))
2391 next_type = btf_type_id_resolve(btf, &next_type_id);
2393 /* "typedef void new_void", "const void"...etc */
2394 if (!btf_type_is_void(next_type) &&
2395 !btf_type_is_fwd(next_type) &&
2396 !btf_type_is_func_proto(next_type)) {
2397 btf_verifier_log_type(env, v->t, "Invalid type_id");
2402 env_stack_pop_resolved(env, next_type_id, 0);
2407 static int btf_var_resolve(struct btf_verifier_env *env,
2408 const struct resolve_vertex *v)
2410 const struct btf_type *next_type;
2411 const struct btf_type *t = v->t;
2412 u32 next_type_id = t->type;
2413 struct btf *btf = env->btf;
2415 next_type = btf_type_by_id(btf, next_type_id);
2416 if (!next_type || btf_type_is_resolve_source_only(next_type)) {
2417 btf_verifier_log_type(env, v->t, "Invalid type_id");
2421 if (!env_type_is_resolve_sink(env, next_type) &&
2422 !env_type_is_resolved(env, next_type_id))
2423 return env_stack_push(env, next_type, next_type_id);
2425 if (btf_type_is_modifier(next_type)) {
2426 const struct btf_type *resolved_type;
2427 u32 resolved_type_id;
2429 resolved_type_id = next_type_id;
2430 resolved_type = btf_type_id_resolve(btf, &resolved_type_id);
2432 if (btf_type_is_ptr(resolved_type) &&
2433 !env_type_is_resolve_sink(env, resolved_type) &&
2434 !env_type_is_resolved(env, resolved_type_id))
2435 return env_stack_push(env, resolved_type,
2439 /* We must resolve to something concrete at this point, no
2440 * forward types or similar that would resolve to size of
2443 if (!btf_type_id_size(btf, &next_type_id, NULL)) {
2444 btf_verifier_log_type(env, v->t, "Invalid type_id");
2448 env_stack_pop_resolved(env, next_type_id, 0);
2453 static int btf_ptr_resolve(struct btf_verifier_env *env,
2454 const struct resolve_vertex *v)
2456 const struct btf_type *next_type;
2457 const struct btf_type *t = v->t;
2458 u32 next_type_id = t->type;
2459 struct btf *btf = env->btf;
2461 next_type = btf_type_by_id(btf, next_type_id);
2462 if (!next_type || btf_type_is_resolve_source_only(next_type)) {
2463 btf_verifier_log_type(env, v->t, "Invalid type_id");
2467 if (!env_type_is_resolve_sink(env, next_type) &&
2468 !env_type_is_resolved(env, next_type_id))
2469 return env_stack_push(env, next_type, next_type_id);
2471 /* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY,
2472 * the modifier may have stopped resolving when it was resolved
2473 * to a ptr (last-resolved-ptr).
2475 * We now need to continue from the last-resolved-ptr to
2476 * ensure the last-resolved-ptr will not referring back to
2477 * the currenct ptr (t).
2479 if (btf_type_is_modifier(next_type)) {
2480 const struct btf_type *resolved_type;
2481 u32 resolved_type_id;
2483 resolved_type_id = next_type_id;
2484 resolved_type = btf_type_id_resolve(btf, &resolved_type_id);
2486 if (btf_type_is_ptr(resolved_type) &&
2487 !env_type_is_resolve_sink(env, resolved_type) &&
2488 !env_type_is_resolved(env, resolved_type_id))
2489 return env_stack_push(env, resolved_type,
2493 if (!btf_type_id_size(btf, &next_type_id, NULL)) {
2494 if (env_type_is_resolved(env, next_type_id))
2495 next_type = btf_type_id_resolve(btf, &next_type_id);
2497 if (!btf_type_is_void(next_type) &&
2498 !btf_type_is_fwd(next_type) &&
2499 !btf_type_is_func_proto(next_type)) {
2500 btf_verifier_log_type(env, v->t, "Invalid type_id");
2505 env_stack_pop_resolved(env, next_type_id, 0);
2510 static void btf_modifier_show(const struct btf *btf,
2511 const struct btf_type *t,
2512 u32 type_id, void *data,
2513 u8 bits_offset, struct btf_show *show)
2515 if (btf->resolved_ids)
2516 t = btf_type_id_resolve(btf, &type_id);
2518 t = btf_type_skip_modifiers(btf, type_id, NULL);
2520 btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show);
2523 static void btf_var_show(const struct btf *btf, const struct btf_type *t,
2524 u32 type_id, void *data, u8 bits_offset,
2525 struct btf_show *show)
2527 t = btf_type_id_resolve(btf, &type_id);
2529 btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show);
2532 static void btf_ptr_show(const struct btf *btf, const struct btf_type *t,
2533 u32 type_id, void *data, u8 bits_offset,
2534 struct btf_show *show)
2538 safe_data = btf_show_start_type(show, t, type_id, data);
2542 /* It is a hashed value unless BTF_SHOW_PTR_RAW is specified */
2543 if (show->flags & BTF_SHOW_PTR_RAW)
2544 btf_show_type_value(show, "0x%px", *(void **)safe_data);
2546 btf_show_type_value(show, "0x%p", *(void **)safe_data);
2547 btf_show_end_type(show);
2550 static void btf_ref_type_log(struct btf_verifier_env *env,
2551 const struct btf_type *t)
2553 btf_verifier_log(env, "type_id=%u", t->type);
2556 static struct btf_kind_operations modifier_ops = {
2557 .check_meta = btf_ref_type_check_meta,
2558 .resolve = btf_modifier_resolve,
2559 .check_member = btf_modifier_check_member,
2560 .check_kflag_member = btf_modifier_check_kflag_member,
2561 .log_details = btf_ref_type_log,
2562 .show = btf_modifier_show,
2565 static struct btf_kind_operations ptr_ops = {
2566 .check_meta = btf_ref_type_check_meta,
2567 .resolve = btf_ptr_resolve,
2568 .check_member = btf_ptr_check_member,
2569 .check_kflag_member = btf_generic_check_kflag_member,
2570 .log_details = btf_ref_type_log,
2571 .show = btf_ptr_show,
2574 static s32 btf_fwd_check_meta(struct btf_verifier_env *env,
2575 const struct btf_type *t,
2578 if (btf_type_vlen(t)) {
2579 btf_verifier_log_type(env, t, "vlen != 0");
2584 btf_verifier_log_type(env, t, "type != 0");
2588 /* fwd type must have a valid name */
2590 !btf_name_valid_identifier(env->btf, t->name_off)) {
2591 btf_verifier_log_type(env, t, "Invalid name");
2595 btf_verifier_log_type(env, t, NULL);
2600 static void btf_fwd_type_log(struct btf_verifier_env *env,
2601 const struct btf_type *t)
2603 btf_verifier_log(env, "%s", btf_type_kflag(t) ? "union" : "struct");
2606 static struct btf_kind_operations fwd_ops = {
2607 .check_meta = btf_fwd_check_meta,
2608 .resolve = btf_df_resolve,
2609 .check_member = btf_df_check_member,
2610 .check_kflag_member = btf_df_check_kflag_member,
2611 .log_details = btf_fwd_type_log,
2612 .show = btf_df_show,
2615 static int btf_array_check_member(struct btf_verifier_env *env,
2616 const struct btf_type *struct_type,
2617 const struct btf_member *member,
2618 const struct btf_type *member_type)
2620 u32 struct_bits_off = member->offset;
2621 u32 struct_size, bytes_offset;
2622 u32 array_type_id, array_size;
2623 struct btf *btf = env->btf;
2625 if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
2626 btf_verifier_log_member(env, struct_type, member,
2627 "Member is not byte aligned");
2631 array_type_id = member->type;
2632 btf_type_id_size(btf, &array_type_id, &array_size);
2633 struct_size = struct_type->size;
2634 bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
2635 if (struct_size - bytes_offset < array_size) {
2636 btf_verifier_log_member(env, struct_type, member,
2637 "Member exceeds struct_size");
2644 static s32 btf_array_check_meta(struct btf_verifier_env *env,
2645 const struct btf_type *t,
2648 const struct btf_array *array = btf_type_array(t);
2649 u32 meta_needed = sizeof(*array);
2651 if (meta_left < meta_needed) {
2652 btf_verifier_log_basic(env, t,
2653 "meta_left:%u meta_needed:%u",
2654 meta_left, meta_needed);
2658 /* array type should not have a name */
2660 btf_verifier_log_type(env, t, "Invalid name");
2664 if (btf_type_vlen(t)) {
2665 btf_verifier_log_type(env, t, "vlen != 0");
2669 if (btf_type_kflag(t)) {
2670 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
2675 btf_verifier_log_type(env, t, "size != 0");
2679 /* Array elem type and index type cannot be in type void,
2680 * so !array->type and !array->index_type are not allowed.
2682 if (!array->type || !BTF_TYPE_ID_VALID(array->type)) {
2683 btf_verifier_log_type(env, t, "Invalid elem");
2687 if (!array->index_type || !BTF_TYPE_ID_VALID(array->index_type)) {
2688 btf_verifier_log_type(env, t, "Invalid index");
2692 btf_verifier_log_type(env, t, NULL);
2697 static int btf_array_resolve(struct btf_verifier_env *env,
2698 const struct resolve_vertex *v)
2700 const struct btf_array *array = btf_type_array(v->t);
2701 const struct btf_type *elem_type, *index_type;
2702 u32 elem_type_id, index_type_id;
2703 struct btf *btf = env->btf;
2706 /* Check array->index_type */
2707 index_type_id = array->index_type;
2708 index_type = btf_type_by_id(btf, index_type_id);
2709 if (btf_type_nosize_or_null(index_type) ||
2710 btf_type_is_resolve_source_only(index_type)) {
2711 btf_verifier_log_type(env, v->t, "Invalid index");
2715 if (!env_type_is_resolve_sink(env, index_type) &&
2716 !env_type_is_resolved(env, index_type_id))
2717 return env_stack_push(env, index_type, index_type_id);
2719 index_type = btf_type_id_size(btf, &index_type_id, NULL);
2720 if (!index_type || !btf_type_is_int(index_type) ||
2721 !btf_type_int_is_regular(index_type)) {
2722 btf_verifier_log_type(env, v->t, "Invalid index");
2726 /* Check array->type */
2727 elem_type_id = array->type;
2728 elem_type = btf_type_by_id(btf, elem_type_id);
2729 if (btf_type_nosize_or_null(elem_type) ||
2730 btf_type_is_resolve_source_only(elem_type)) {
2731 btf_verifier_log_type(env, v->t,
2736 if (!env_type_is_resolve_sink(env, elem_type) &&
2737 !env_type_is_resolved(env, elem_type_id))
2738 return env_stack_push(env, elem_type, elem_type_id);
2740 elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size);
2742 btf_verifier_log_type(env, v->t, "Invalid elem");
2746 if (btf_type_is_int(elem_type) && !btf_type_int_is_regular(elem_type)) {
2747 btf_verifier_log_type(env, v->t, "Invalid array of int");
2751 if (array->nelems && elem_size > U32_MAX / array->nelems) {
2752 btf_verifier_log_type(env, v->t,
2753 "Array size overflows U32_MAX");
2757 env_stack_pop_resolved(env, elem_type_id, elem_size * array->nelems);
2762 static void btf_array_log(struct btf_verifier_env *env,
2763 const struct btf_type *t)
2765 const struct btf_array *array = btf_type_array(t);
2767 btf_verifier_log(env, "type_id=%u index_type_id=%u nr_elems=%u",
2768 array->type, array->index_type, array->nelems);
2771 static void __btf_array_show(const struct btf *btf, const struct btf_type *t,
2772 u32 type_id, void *data, u8 bits_offset,
2773 struct btf_show *show)
2775 const struct btf_array *array = btf_type_array(t);
2776 const struct btf_kind_operations *elem_ops;
2777 const struct btf_type *elem_type;
2778 u32 i, elem_size = 0, elem_type_id;
2781 elem_type_id = array->type;
2782 elem_type = btf_type_skip_modifiers(btf, elem_type_id, NULL);
2783 if (elem_type && btf_type_has_size(elem_type))
2784 elem_size = elem_type->size;
2786 if (elem_type && btf_type_is_int(elem_type)) {
2787 u32 int_type = btf_type_int(elem_type);
2789 encoding = BTF_INT_ENCODING(int_type);
2792 * BTF_INT_CHAR encoding never seems to be set for
2793 * char arrays, so if size is 1 and element is
2794 * printable as a char, we'll do that.
2797 encoding = BTF_INT_CHAR;
2800 if (!btf_show_start_array_type(show, t, type_id, encoding, data))
2805 elem_ops = btf_type_ops(elem_type);
2807 for (i = 0; i < array->nelems; i++) {
2809 btf_show_start_array_member(show);
2811 elem_ops->show(btf, elem_type, elem_type_id, data,
2815 btf_show_end_array_member(show);
2817 if (show->state.array_terminated)
2821 btf_show_end_array_type(show);
2824 static void btf_array_show(const struct btf *btf, const struct btf_type *t,
2825 u32 type_id, void *data, u8 bits_offset,
2826 struct btf_show *show)
2828 const struct btf_member *m = show->state.member;
2831 * First check if any members would be shown (are non-zero).
2832 * See comments above "struct btf_show" definition for more
2833 * details on how this works at a high-level.
2835 if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) {
2836 if (!show->state.depth_check) {
2837 show->state.depth_check = show->state.depth + 1;
2838 show->state.depth_to_show = 0;
2840 __btf_array_show(btf, t, type_id, data, bits_offset, show);
2841 show->state.member = m;
2843 if (show->state.depth_check != show->state.depth + 1)
2845 show->state.depth_check = 0;
2847 if (show->state.depth_to_show <= show->state.depth)
2850 * Reaching here indicates we have recursed and found
2851 * non-zero array member(s).
2854 __btf_array_show(btf, t, type_id, data, bits_offset, show);
2857 static struct btf_kind_operations array_ops = {
2858 .check_meta = btf_array_check_meta,
2859 .resolve = btf_array_resolve,
2860 .check_member = btf_array_check_member,
2861 .check_kflag_member = btf_generic_check_kflag_member,
2862 .log_details = btf_array_log,
2863 .show = btf_array_show,
2866 static int btf_struct_check_member(struct btf_verifier_env *env,
2867 const struct btf_type *struct_type,
2868 const struct btf_member *member,
2869 const struct btf_type *member_type)
2871 u32 struct_bits_off = member->offset;
2872 u32 struct_size, bytes_offset;
2874 if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
2875 btf_verifier_log_member(env, struct_type, member,
2876 "Member is not byte aligned");
2880 struct_size = struct_type->size;
2881 bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
2882 if (struct_size - bytes_offset < member_type->size) {
2883 btf_verifier_log_member(env, struct_type, member,
2884 "Member exceeds struct_size");
2891 static s32 btf_struct_check_meta(struct btf_verifier_env *env,
2892 const struct btf_type *t,
2895 bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION;
2896 const struct btf_member *member;
2897 u32 meta_needed, last_offset;
2898 struct btf *btf = env->btf;
2899 u32 struct_size = t->size;
2903 meta_needed = btf_type_vlen(t) * sizeof(*member);
2904 if (meta_left < meta_needed) {
2905 btf_verifier_log_basic(env, t,
2906 "meta_left:%u meta_needed:%u",
2907 meta_left, meta_needed);
2911 /* struct type either no name or a valid one */
2913 !btf_name_valid_identifier(env->btf, t->name_off)) {
2914 btf_verifier_log_type(env, t, "Invalid name");
2918 btf_verifier_log_type(env, t, NULL);
2921 for_each_member(i, t, member) {
2922 if (!btf_name_offset_valid(btf, member->name_off)) {
2923 btf_verifier_log_member(env, t, member,
2924 "Invalid member name_offset:%u",
2929 /* struct member either no name or a valid one */
2930 if (member->name_off &&
2931 !btf_name_valid_identifier(btf, member->name_off)) {
2932 btf_verifier_log_member(env, t, member, "Invalid name");
2935 /* A member cannot be in type void */
2936 if (!member->type || !BTF_TYPE_ID_VALID(member->type)) {
2937 btf_verifier_log_member(env, t, member,
2942 offset = btf_member_bit_offset(t, member);
2943 if (is_union && offset) {
2944 btf_verifier_log_member(env, t, member,
2945 "Invalid member bits_offset");
2950 * ">" instead of ">=" because the last member could be
2953 if (last_offset > offset) {
2954 btf_verifier_log_member(env, t, member,
2955 "Invalid member bits_offset");
2959 if (BITS_ROUNDUP_BYTES(offset) > struct_size) {
2960 btf_verifier_log_member(env, t, member,
2961 "Member bits_offset exceeds its struct size");
2965 btf_verifier_log_member(env, t, member, NULL);
2966 last_offset = offset;
2972 static int btf_struct_resolve(struct btf_verifier_env *env,
2973 const struct resolve_vertex *v)
2975 const struct btf_member *member;
2979 /* Before continue resolving the next_member,
2980 * ensure the last member is indeed resolved to a
2981 * type with size info.
2983 if (v->next_member) {
2984 const struct btf_type *last_member_type;
2985 const struct btf_member *last_member;
2986 u16 last_member_type_id;
2988 last_member = btf_type_member(v->t) + v->next_member - 1;
2989 last_member_type_id = last_member->type;
2990 if (WARN_ON_ONCE(!env_type_is_resolved(env,
2991 last_member_type_id)))
2994 last_member_type = btf_type_by_id(env->btf,
2995 last_member_type_id);
2996 if (btf_type_kflag(v->t))
2997 err = btf_type_ops(last_member_type)->check_kflag_member(env, v->t,
3001 err = btf_type_ops(last_member_type)->check_member(env, v->t,
3008 for_each_member_from(i, v->next_member, v->t, member) {
3009 u32 member_type_id = member->type;
3010 const struct btf_type *member_type = btf_type_by_id(env->btf,
3013 if (btf_type_nosize_or_null(member_type) ||
3014 btf_type_is_resolve_source_only(member_type)) {
3015 btf_verifier_log_member(env, v->t, member,
3020 if (!env_type_is_resolve_sink(env, member_type) &&
3021 !env_type_is_resolved(env, member_type_id)) {
3022 env_stack_set_next_member(env, i + 1);
3023 return env_stack_push(env, member_type, member_type_id);
3026 if (btf_type_kflag(v->t))
3027 err = btf_type_ops(member_type)->check_kflag_member(env, v->t,
3031 err = btf_type_ops(member_type)->check_member(env, v->t,
3038 env_stack_pop_resolved(env, 0, 0);
3043 static void btf_struct_log(struct btf_verifier_env *env,
3044 const struct btf_type *t)
3046 btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
3049 static int btf_find_struct_field(const struct btf *btf, const struct btf_type *t,
3050 const char *name, int sz, int align)
3052 const struct btf_member *member;
3053 u32 i, off = -ENOENT;
3055 for_each_member(i, t, member) {
3056 const struct btf_type *member_type = btf_type_by_id(btf,
3058 if (!__btf_type_is_struct(member_type))
3060 if (member_type->size != sz)
3062 if (strcmp(__btf_name_by_offset(btf, member_type->name_off), name))
3065 /* only one such field is allowed */
3067 off = btf_member_bit_offset(t, member);
3069 /* valid C code cannot generate such BTF */
3078 static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t,
3079 const char *name, int sz, int align)
3081 const struct btf_var_secinfo *vsi;
3082 u32 i, off = -ENOENT;
3084 for_each_vsi(i, t, vsi) {
3085 const struct btf_type *var = btf_type_by_id(btf, vsi->type);
3086 const struct btf_type *var_type = btf_type_by_id(btf, var->type);
3088 if (!__btf_type_is_struct(var_type))
3090 if (var_type->size != sz)
3092 if (vsi->size != sz)
3094 if (strcmp(__btf_name_by_offset(btf, var_type->name_off), name))
3097 /* only one such field is allowed */
3106 static int btf_find_field(const struct btf *btf, const struct btf_type *t,
3107 const char *name, int sz, int align)
3110 if (__btf_type_is_struct(t))
3111 return btf_find_struct_field(btf, t, name, sz, align);
3112 else if (btf_type_is_datasec(t))
3113 return btf_find_datasec_var(btf, t, name, sz, align);
3117 /* find 'struct bpf_spin_lock' in map value.
3118 * return >= 0 offset if found
3119 * and < 0 in case of error
3121 int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t)
3123 return btf_find_field(btf, t, "bpf_spin_lock",
3124 sizeof(struct bpf_spin_lock),
3125 __alignof__(struct bpf_spin_lock));
3128 int btf_find_timer(const struct btf *btf, const struct btf_type *t)
3130 return btf_find_field(btf, t, "bpf_timer",
3131 sizeof(struct bpf_timer),
3132 __alignof__(struct bpf_timer));
3135 static void __btf_struct_show(const struct btf *btf, const struct btf_type *t,
3136 u32 type_id, void *data, u8 bits_offset,
3137 struct btf_show *show)
3139 const struct btf_member *member;
3143 safe_data = btf_show_start_struct_type(show, t, type_id, data);
3147 for_each_member(i, t, member) {
3148 const struct btf_type *member_type = btf_type_by_id(btf,
3150 const struct btf_kind_operations *ops;
3151 u32 member_offset, bitfield_size;
3155 btf_show_start_member(show, member);
3157 member_offset = btf_member_bit_offset(t, member);
3158 bitfield_size = btf_member_bitfield_size(t, member);
3159 bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset);
3160 bits8_offset = BITS_PER_BYTE_MASKED(member_offset);
3161 if (bitfield_size) {
3162 safe_data = btf_show_start_type(show, member_type,
3164 data + bytes_offset);
3166 btf_bitfield_show(safe_data,
3168 bitfield_size, show);
3169 btf_show_end_type(show);
3171 ops = btf_type_ops(member_type);
3172 ops->show(btf, member_type, member->type,
3173 data + bytes_offset, bits8_offset, show);
3176 btf_show_end_member(show);
3179 btf_show_end_struct_type(show);
3182 static void btf_struct_show(const struct btf *btf, const struct btf_type *t,
3183 u32 type_id, void *data, u8 bits_offset,
3184 struct btf_show *show)
3186 const struct btf_member *m = show->state.member;
3189 * First check if any members would be shown (are non-zero).
3190 * See comments above "struct btf_show" definition for more
3191 * details on how this works at a high-level.
3193 if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) {
3194 if (!show->state.depth_check) {
3195 show->state.depth_check = show->state.depth + 1;
3196 show->state.depth_to_show = 0;
3198 __btf_struct_show(btf, t, type_id, data, bits_offset, show);
3199 /* Restore saved member data here */
3200 show->state.member = m;
3201 if (show->state.depth_check != show->state.depth + 1)
3203 show->state.depth_check = 0;
3205 if (show->state.depth_to_show <= show->state.depth)
3208 * Reaching here indicates we have recursed and found
3209 * non-zero child values.
3213 __btf_struct_show(btf, t, type_id, data, bits_offset, show);
3216 static struct btf_kind_operations struct_ops = {
3217 .check_meta = btf_struct_check_meta,
3218 .resolve = btf_struct_resolve,
3219 .check_member = btf_struct_check_member,
3220 .check_kflag_member = btf_generic_check_kflag_member,
3221 .log_details = btf_struct_log,
3222 .show = btf_struct_show,
3225 static int btf_enum_check_member(struct btf_verifier_env *env,
3226 const struct btf_type *struct_type,
3227 const struct btf_member *member,
3228 const struct btf_type *member_type)
3230 u32 struct_bits_off = member->offset;
3231 u32 struct_size, bytes_offset;
3233 if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
3234 btf_verifier_log_member(env, struct_type, member,
3235 "Member is not byte aligned");
3239 struct_size = struct_type->size;
3240 bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
3241 if (struct_size - bytes_offset < member_type->size) {
3242 btf_verifier_log_member(env, struct_type, member,
3243 "Member exceeds struct_size");
3250 static int btf_enum_check_kflag_member(struct btf_verifier_env *env,
3251 const struct btf_type *struct_type,
3252 const struct btf_member *member,
3253 const struct btf_type *member_type)
3255 u32 struct_bits_off, nr_bits, bytes_end, struct_size;
3256 u32 int_bitsize = sizeof(int) * BITS_PER_BYTE;
3258 struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset);
3259 nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset);
3261 if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
3262 btf_verifier_log_member(env, struct_type, member,
3263 "Member is not byte aligned");
3267 nr_bits = int_bitsize;
3268 } else if (nr_bits > int_bitsize) {
3269 btf_verifier_log_member(env, struct_type, member,
3270 "Invalid member bitfield_size");
3274 struct_size = struct_type->size;
3275 bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits);
3276 if (struct_size < bytes_end) {
3277 btf_verifier_log_member(env, struct_type, member,
3278 "Member exceeds struct_size");
3285 static s32 btf_enum_check_meta(struct btf_verifier_env *env,
3286 const struct btf_type *t,
3289 const struct btf_enum *enums = btf_type_enum(t);
3290 struct btf *btf = env->btf;
3294 nr_enums = btf_type_vlen(t);
3295 meta_needed = nr_enums * sizeof(*enums);
3297 if (meta_left < meta_needed) {
3298 btf_verifier_log_basic(env, t,
3299 "meta_left:%u meta_needed:%u",
3300 meta_left, meta_needed);
3304 if (btf_type_kflag(t)) {
3305 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
3309 if (t->size > 8 || !is_power_of_2(t->size)) {
3310 btf_verifier_log_type(env, t, "Unexpected size");
3314 /* enum type either no name or a valid one */
3316 !btf_name_valid_identifier(env->btf, t->name_off)) {
3317 btf_verifier_log_type(env, t, "Invalid name");
3321 btf_verifier_log_type(env, t, NULL);
3323 for (i = 0; i < nr_enums; i++) {
3324 if (!btf_name_offset_valid(btf, enums[i].name_off)) {
3325 btf_verifier_log(env, "\tInvalid name_offset:%u",
3330 /* enum member must have a valid name */
3331 if (!enums[i].name_off ||
3332 !btf_name_valid_identifier(btf, enums[i].name_off)) {
3333 btf_verifier_log_type(env, t, "Invalid name");
3337 if (env->log.level == BPF_LOG_KERNEL)
3339 btf_verifier_log(env, "\t%s val=%d\n",
3340 __btf_name_by_offset(btf, enums[i].name_off),
3347 static void btf_enum_log(struct btf_verifier_env *env,
3348 const struct btf_type *t)
3350 btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
3353 static void btf_enum_show(const struct btf *btf, const struct btf_type *t,
3354 u32 type_id, void *data, u8 bits_offset,
3355 struct btf_show *show)
3357 const struct btf_enum *enums = btf_type_enum(t);
3358 u32 i, nr_enums = btf_type_vlen(t);
3362 safe_data = btf_show_start_type(show, t, type_id, data);
3366 v = *(int *)safe_data;
3368 for (i = 0; i < nr_enums; i++) {
3369 if (v != enums[i].val)
3372 btf_show_type_value(show, "%s",
3373 __btf_name_by_offset(btf,
3374 enums[i].name_off));
3376 btf_show_end_type(show);
3380 btf_show_type_value(show, "%d", v);
3381 btf_show_end_type(show);
3384 static struct btf_kind_operations enum_ops = {
3385 .check_meta = btf_enum_check_meta,
3386 .resolve = btf_df_resolve,
3387 .check_member = btf_enum_check_member,
3388 .check_kflag_member = btf_enum_check_kflag_member,
3389 .log_details = btf_enum_log,
3390 .show = btf_enum_show,
3393 static s32 btf_func_proto_check_meta(struct btf_verifier_env *env,
3394 const struct btf_type *t,
3397 u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param);
3399 if (meta_left < meta_needed) {
3400 btf_verifier_log_basic(env, t,
3401 "meta_left:%u meta_needed:%u",
3402 meta_left, meta_needed);
3407 btf_verifier_log_type(env, t, "Invalid name");
3411 if (btf_type_kflag(t)) {
3412 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
3416 btf_verifier_log_type(env, t, NULL);
3421 static void btf_func_proto_log(struct btf_verifier_env *env,
3422 const struct btf_type *t)
3424 const struct btf_param *args = (const struct btf_param *)(t + 1);
3425 u16 nr_args = btf_type_vlen(t), i;
3427 btf_verifier_log(env, "return=%u args=(", t->type);
3429 btf_verifier_log(env, "void");
3433 if (nr_args == 1 && !args[0].type) {
3434 /* Only one vararg */
3435 btf_verifier_log(env, "vararg");
3439 btf_verifier_log(env, "%u %s", args[0].type,
3440 __btf_name_by_offset(env->btf,
3442 for (i = 1; i < nr_args - 1; i++)
3443 btf_verifier_log(env, ", %u %s", args[i].type,
3444 __btf_name_by_offset(env->btf,
3448 const struct btf_param *last_arg = &args[nr_args - 1];
3451 btf_verifier_log(env, ", %u %s", last_arg->type,
3452 __btf_name_by_offset(env->btf,
3453 last_arg->name_off));
3455 btf_verifier_log(env, ", vararg");
3459 btf_verifier_log(env, ")");
3462 static struct btf_kind_operations func_proto_ops = {
3463 .check_meta = btf_func_proto_check_meta,
3464 .resolve = btf_df_resolve,
3466 * BTF_KIND_FUNC_PROTO cannot be directly referred by
3467 * a struct's member.
3469 * It should be a function pointer instead.
3470 * (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO)
3472 * Hence, there is no btf_func_check_member().
3474 .check_member = btf_df_check_member,
3475 .check_kflag_member = btf_df_check_kflag_member,
3476 .log_details = btf_func_proto_log,
3477 .show = btf_df_show,
3480 static s32 btf_func_check_meta(struct btf_verifier_env *env,
3481 const struct btf_type *t,
3485 !btf_name_valid_identifier(env->btf, t->name_off)) {
3486 btf_verifier_log_type(env, t, "Invalid name");
3490 if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) {
3491 btf_verifier_log_type(env, t, "Invalid func linkage");
3495 if (btf_type_kflag(t)) {
3496 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
3500 btf_verifier_log_type(env, t, NULL);
3505 static struct btf_kind_operations func_ops = {
3506 .check_meta = btf_func_check_meta,
3507 .resolve = btf_df_resolve,
3508 .check_member = btf_df_check_member,
3509 .check_kflag_member = btf_df_check_kflag_member,
3510 .log_details = btf_ref_type_log,
3511 .show = btf_df_show,
3514 static s32 btf_var_check_meta(struct btf_verifier_env *env,
3515 const struct btf_type *t,
3518 const struct btf_var *var;
3519 u32 meta_needed = sizeof(*var);
3521 if (meta_left < meta_needed) {
3522 btf_verifier_log_basic(env, t,
3523 "meta_left:%u meta_needed:%u",
3524 meta_left, meta_needed);
3528 if (btf_type_vlen(t)) {
3529 btf_verifier_log_type(env, t, "vlen != 0");
3533 if (btf_type_kflag(t)) {
3534 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
3539 !__btf_name_valid(env->btf, t->name_off, true)) {
3540 btf_verifier_log_type(env, t, "Invalid name");
3544 /* A var cannot be in type void */
3545 if (!t->type || !BTF_TYPE_ID_VALID(t->type)) {
3546 btf_verifier_log_type(env, t, "Invalid type_id");
3550 var = btf_type_var(t);
3551 if (var->linkage != BTF_VAR_STATIC &&
3552 var->linkage != BTF_VAR_GLOBAL_ALLOCATED) {
3553 btf_verifier_log_type(env, t, "Linkage not supported");
3557 btf_verifier_log_type(env, t, NULL);
3562 static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t)
3564 const struct btf_var *var = btf_type_var(t);
3566 btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage);
3569 static const struct btf_kind_operations var_ops = {
3570 .check_meta = btf_var_check_meta,
3571 .resolve = btf_var_resolve,
3572 .check_member = btf_df_check_member,
3573 .check_kflag_member = btf_df_check_kflag_member,
3574 .log_details = btf_var_log,
3575 .show = btf_var_show,
3578 static s32 btf_datasec_check_meta(struct btf_verifier_env *env,
3579 const struct btf_type *t,
3582 const struct btf_var_secinfo *vsi;
3583 u64 last_vsi_end_off = 0, sum = 0;
3586 meta_needed = btf_type_vlen(t) * sizeof(*vsi);
3587 if (meta_left < meta_needed) {
3588 btf_verifier_log_basic(env, t,
3589 "meta_left:%u meta_needed:%u",
3590 meta_left, meta_needed);
3595 btf_verifier_log_type(env, t, "size == 0");
3599 if (btf_type_kflag(t)) {
3600 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
3605 !btf_name_valid_section(env->btf, t->name_off)) {
3606 btf_verifier_log_type(env, t, "Invalid name");
3610 btf_verifier_log_type(env, t, NULL);
3612 for_each_vsi(i, t, vsi) {
3613 /* A var cannot be in type void */
3614 if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) {
3615 btf_verifier_log_vsi(env, t, vsi,
3620 if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) {
3621 btf_verifier_log_vsi(env, t, vsi,
3626 if (!vsi->size || vsi->size > t->size) {
3627 btf_verifier_log_vsi(env, t, vsi,
3632 last_vsi_end_off = vsi->offset + vsi->size;
3633 if (last_vsi_end_off > t->size) {
3634 btf_verifier_log_vsi(env, t, vsi,
3635 "Invalid offset+size");
3639 btf_verifier_log_vsi(env, t, vsi, NULL);
3643 if (t->size < sum) {
3644 btf_verifier_log_type(env, t, "Invalid btf_info size");
3651 static int btf_datasec_resolve(struct btf_verifier_env *env,
3652 const struct resolve_vertex *v)
3654 const struct btf_var_secinfo *vsi;
3655 struct btf *btf = env->btf;
3658 for_each_vsi_from(i, v->next_member, v->t, vsi) {
3659 u32 var_type_id = vsi->type, type_id, type_size = 0;
3660 const struct btf_type *var_type = btf_type_by_id(env->btf,
3662 if (!var_type || !btf_type_is_var(var_type)) {
3663 btf_verifier_log_vsi(env, v->t, vsi,
3664 "Not a VAR kind member");
3668 if (!env_type_is_resolve_sink(env, var_type) &&
3669 !env_type_is_resolved(env, var_type_id)) {
3670 env_stack_set_next_member(env, i + 1);
3671 return env_stack_push(env, var_type, var_type_id);
3674 type_id = var_type->type;
3675 if (!btf_type_id_size(btf, &type_id, &type_size)) {
3676 btf_verifier_log_vsi(env, v->t, vsi, "Invalid type");
3680 if (vsi->size < type_size) {
3681 btf_verifier_log_vsi(env, v->t, vsi, "Invalid size");
3686 env_stack_pop_resolved(env, 0, 0);
3690 static void btf_datasec_log(struct btf_verifier_env *env,
3691 const struct btf_type *t)
3693 btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
3696 static void btf_datasec_show(const struct btf *btf,
3697 const struct btf_type *t, u32 type_id,
3698 void *data, u8 bits_offset,
3699 struct btf_show *show)
3701 const struct btf_var_secinfo *vsi;
3702 const struct btf_type *var;
3705 if (!btf_show_start_type(show, t, type_id, data))
3708 btf_show_type_value(show, "section (\"%s\") = {",
3709 __btf_name_by_offset(btf, t->name_off));
3710 for_each_vsi(i, t, vsi) {
3711 var = btf_type_by_id(btf, vsi->type);
3713 btf_show(show, ",");
3714 btf_type_ops(var)->show(btf, var, vsi->type,
3715 data + vsi->offset, bits_offset, show);
3717 btf_show_end_type(show);
3720 static const struct btf_kind_operations datasec_ops = {
3721 .check_meta = btf_datasec_check_meta,
3722 .resolve = btf_datasec_resolve,
3723 .check_member = btf_df_check_member,
3724 .check_kflag_member = btf_df_check_kflag_member,
3725 .log_details = btf_datasec_log,
3726 .show = btf_datasec_show,
3729 static s32 btf_float_check_meta(struct btf_verifier_env *env,
3730 const struct btf_type *t,
3733 if (btf_type_vlen(t)) {
3734 btf_verifier_log_type(env, t, "vlen != 0");
3738 if (btf_type_kflag(t)) {
3739 btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
3743 if (t->size != 2 && t->size != 4 && t->size != 8 && t->size != 12 &&
3745 btf_verifier_log_type(env, t, "Invalid type_size");
3749 btf_verifier_log_type(env, t, NULL);
3754 static int btf_float_check_member(struct btf_verifier_env *env,
3755 const struct btf_type *struct_type,
3756 const struct btf_member *member,
3757 const struct btf_type *member_type)
3759 u64 start_offset_bytes;
3760 u64 end_offset_bytes;
3765 /* Different architectures have different alignment requirements, so
3766 * here we check only for the reasonable minimum. This way we ensure
3767 * that types after CO-RE can pass the kernel BTF verifier.
3769 align_bytes = min_t(u64, sizeof(void *), member_type->size);
3770 align_bits = align_bytes * BITS_PER_BYTE;
3771 div64_u64_rem(member->offset, align_bits, &misalign_bits);
3772 if (misalign_bits) {
3773 btf_verifier_log_member(env, struct_type, member,
3774 "Member is not properly aligned");
3778 start_offset_bytes = member->offset / BITS_PER_BYTE;
3779 end_offset_bytes = start_offset_bytes + member_type->size;
3780 if (end_offset_bytes > struct_type->size) {
3781 btf_verifier_log_member(env, struct_type, member,
3782 "Member exceeds struct_size");
3789 static void btf_float_log(struct btf_verifier_env *env,
3790 const struct btf_type *t)
3792 btf_verifier_log(env, "size=%u", t->size);
3795 static const struct btf_kind_operations float_ops = {
3796 .check_meta = btf_float_check_meta,
3797 .resolve = btf_df_resolve,
3798 .check_member = btf_float_check_member,
3799 .check_kflag_member = btf_generic_check_kflag_member,
3800 .log_details = btf_float_log,
3801 .show = btf_df_show,
3804 static int btf_func_proto_check(struct btf_verifier_env *env,
3805 const struct btf_type *t)
3807 const struct btf_type *ret_type;
3808 const struct btf_param *args;
3809 const struct btf *btf;
3814 args = (const struct btf_param *)(t + 1);
3815 nr_args = btf_type_vlen(t);
3817 /* Check func return type which could be "void" (t->type == 0) */
3819 u32 ret_type_id = t->type;
3821 ret_type = btf_type_by_id(btf, ret_type_id);
3823 btf_verifier_log_type(env, t, "Invalid return type");
3827 if (btf_type_needs_resolve(ret_type) &&
3828 !env_type_is_resolved(env, ret_type_id)) {
3829 err = btf_resolve(env, ret_type, ret_type_id);
3834 /* Ensure the return type is a type that has a size */
3835 if (!btf_type_id_size(btf, &ret_type_id, NULL)) {
3836 btf_verifier_log_type(env, t, "Invalid return type");
3844 /* Last func arg type_id could be 0 if it is a vararg */
3845 if (!args[nr_args - 1].type) {
3846 if (args[nr_args - 1].name_off) {
3847 btf_verifier_log_type(env, t, "Invalid arg#%u",
3855 for (i = 0; i < nr_args; i++) {
3856 const struct btf_type *arg_type;
3859 arg_type_id = args[i].type;
3860 arg_type = btf_type_by_id(btf, arg_type_id);
3862 btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
3867 if (args[i].name_off &&
3868 (!btf_name_offset_valid(btf, args[i].name_off) ||
3869 !btf_name_valid_identifier(btf, args[i].name_off))) {
3870 btf_verifier_log_type(env, t,
3871 "Invalid arg#%u", i + 1);
3876 if (btf_type_needs_resolve(arg_type) &&
3877 !env_type_is_resolved(env, arg_type_id)) {
3878 err = btf_resolve(env, arg_type, arg_type_id);
3883 if (!btf_type_id_size(btf, &arg_type_id, NULL)) {
3884 btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
3893 static int btf_func_check(struct btf_verifier_env *env,
3894 const struct btf_type *t)
3896 const struct btf_type *proto_type;
3897 const struct btf_param *args;
3898 const struct btf *btf;
3902 proto_type = btf_type_by_id(btf, t->type);
3904 if (!proto_type || !btf_type_is_func_proto(proto_type)) {
3905 btf_verifier_log_type(env, t, "Invalid type_id");
3909 args = (const struct btf_param *)(proto_type + 1);
3910 nr_args = btf_type_vlen(proto_type);
3911 for (i = 0; i < nr_args; i++) {
3912 if (!args[i].name_off && args[i].type) {
3913 btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
3921 static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = {
3922 [BTF_KIND_INT] = &int_ops,
3923 [BTF_KIND_PTR] = &ptr_ops,
3924 [BTF_KIND_ARRAY] = &array_ops,
3925 [BTF_KIND_STRUCT] = &struct_ops,
3926 [BTF_KIND_UNION] = &struct_ops,
3927 [BTF_KIND_ENUM] = &enum_ops,
3928 [BTF_KIND_FWD] = &fwd_ops,
3929 [BTF_KIND_TYPEDEF] = &modifier_ops,
3930 [BTF_KIND_VOLATILE] = &modifier_ops,
3931 [BTF_KIND_CONST] = &modifier_ops,
3932 [BTF_KIND_RESTRICT] = &modifier_ops,
3933 [BTF_KIND_FUNC] = &func_ops,
3934 [BTF_KIND_FUNC_PROTO] = &func_proto_ops,
3935 [BTF_KIND_VAR] = &var_ops,
3936 [BTF_KIND_DATASEC] = &datasec_ops,
3937 [BTF_KIND_FLOAT] = &float_ops,
3940 static s32 btf_check_meta(struct btf_verifier_env *env,
3941 const struct btf_type *t,
3944 u32 saved_meta_left = meta_left;
3947 if (meta_left < sizeof(*t)) {
3948 btf_verifier_log(env, "[%u] meta_left:%u meta_needed:%zu",
3949 env->log_type_id, meta_left, sizeof(*t));
3952 meta_left -= sizeof(*t);
3954 if (t->info & ~BTF_INFO_MASK) {
3955 btf_verifier_log(env, "[%u] Invalid btf_info:%x",
3956 env->log_type_id, t->info);
3960 if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX ||
3961 BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) {
3962 btf_verifier_log(env, "[%u] Invalid kind:%u",
3963 env->log_type_id, BTF_INFO_KIND(t->info));
3967 if (!btf_name_offset_valid(env->btf, t->name_off)) {
3968 btf_verifier_log(env, "[%u] Invalid name_offset:%u",
3969 env->log_type_id, t->name_off);
3973 var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left);
3974 if (var_meta_size < 0)
3975 return var_meta_size;
3977 meta_left -= var_meta_size;
3979 return saved_meta_left - meta_left;
3982 static int btf_check_all_metas(struct btf_verifier_env *env)
3984 struct btf *btf = env->btf;
3985 struct btf_header *hdr;
3989 cur = btf->nohdr_data + hdr->type_off;
3990 end = cur + hdr->type_len;
3992 env->log_type_id = btf->base_btf ? btf->start_id : 1;
3994 struct btf_type *t = cur;
3997 meta_size = btf_check_meta(env, t, end - cur);
4001 btf_add_type(env, t);
4009 static bool btf_resolve_valid(struct btf_verifier_env *env,
4010 const struct btf_type *t,
4013 struct btf *btf = env->btf;
4015 if (!env_type_is_resolved(env, type_id))
4018 if (btf_type_is_struct(t) || btf_type_is_datasec(t))
4019 return !btf_resolved_type_id(btf, type_id) &&
4020 !btf_resolved_type_size(btf, type_id);
4022 if (btf_type_is_modifier(t) || btf_type_is_ptr(t) ||
4023 btf_type_is_var(t)) {
4024 t = btf_type_id_resolve(btf, &type_id);
4026 !btf_type_is_modifier(t) &&
4027 !btf_type_is_var(t) &&
4028 !btf_type_is_datasec(t);
4031 if (btf_type_is_array(t)) {
4032 const struct btf_array *array = btf_type_array(t);
4033 const struct btf_type *elem_type;
4034 u32 elem_type_id = array->type;
4037 elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size);
4038 return elem_type && !btf_type_is_modifier(elem_type) &&
4039 (array->nelems * elem_size ==
4040 btf_resolved_type_size(btf, type_id));
4046 static int btf_resolve(struct btf_verifier_env *env,
4047 const struct btf_type *t, u32 type_id)
4049 u32 save_log_type_id = env->log_type_id;
4050 const struct resolve_vertex *v;
4053 env->resolve_mode = RESOLVE_TBD;
4054 env_stack_push(env, t, type_id);
4055 while (!err && (v = env_stack_peak(env))) {
4056 env->log_type_id = v->type_id;
4057 err = btf_type_ops(v->t)->resolve(env, v);
4060 env->log_type_id = type_id;
4061 if (err == -E2BIG) {
4062 btf_verifier_log_type(env, t,
4063 "Exceeded max resolving depth:%u",
4065 } else if (err == -EEXIST) {
4066 btf_verifier_log_type(env, t, "Loop detected");
4069 /* Final sanity check */
4070 if (!err && !btf_resolve_valid(env, t, type_id)) {
4071 btf_verifier_log_type(env, t, "Invalid resolve state");
4075 env->log_type_id = save_log_type_id;
4079 static int btf_check_all_types(struct btf_verifier_env *env)
4081 struct btf *btf = env->btf;
4082 const struct btf_type *t;
4086 err = env_resolve_init(env);
4091 for (i = btf->base_btf ? 0 : 1; i < btf->nr_types; i++) {
4092 type_id = btf->start_id + i;
4093 t = btf_type_by_id(btf, type_id);
4095 env->log_type_id = type_id;
4096 if (btf_type_needs_resolve(t) &&
4097 !env_type_is_resolved(env, type_id)) {
4098 err = btf_resolve(env, t, type_id);
4103 if (btf_type_is_func_proto(t)) {
4104 err = btf_func_proto_check(env, t);
4109 if (btf_type_is_func(t)) {
4110 err = btf_func_check(env, t);
4119 static int btf_parse_type_sec(struct btf_verifier_env *env)
4121 const struct btf_header *hdr = &env->btf->hdr;
4124 /* Type section must align to 4 bytes */
4125 if (hdr->type_off & (sizeof(u32) - 1)) {
4126 btf_verifier_log(env, "Unaligned type_off");
4130 if (!env->btf->base_btf && !hdr->type_len) {
4131 btf_verifier_log(env, "No type found");
4135 err = btf_check_all_metas(env);
4139 return btf_check_all_types(env);
4142 static int btf_parse_str_sec(struct btf_verifier_env *env)
4144 const struct btf_header *hdr;
4145 struct btf *btf = env->btf;
4146 const char *start, *end;
4149 start = btf->nohdr_data + hdr->str_off;
4150 end = start + hdr->str_len;
4152 if (end != btf->data + btf->data_size) {
4153 btf_verifier_log(env, "String section is not at the end");
4157 btf->strings = start;
4159 if (btf->base_btf && !hdr->str_len)
4161 if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET || end[-1]) {
4162 btf_verifier_log(env, "Invalid string section");
4165 if (!btf->base_btf && start[0]) {
4166 btf_verifier_log(env, "Invalid string section");
4173 static const size_t btf_sec_info_offset[] = {
4174 offsetof(struct btf_header, type_off),
4175 offsetof(struct btf_header, str_off),
4178 static int btf_sec_info_cmp(const void *a, const void *b)
4180 const struct btf_sec_info *x = a;
4181 const struct btf_sec_info *y = b;
4183 return (int)(x->off - y->off) ? : (int)(x->len - y->len);
4186 static int btf_check_sec_info(struct btf_verifier_env *env,
4189 struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)];
4190 u32 total, expected_total, i;
4191 const struct btf_header *hdr;
4192 const struct btf *btf;
4197 /* Populate the secs from hdr */
4198 for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++)
4199 secs[i] = *(struct btf_sec_info *)((void *)hdr +
4200 btf_sec_info_offset[i]);
4202 sort(secs, ARRAY_SIZE(btf_sec_info_offset),
4203 sizeof(struct btf_sec_info), btf_sec_info_cmp, NULL);
4205 /* Check for gaps and overlap among sections */
4207 expected_total = btf_data_size - hdr->hdr_len;
4208 for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) {
4209 if (expected_total < secs[i].off) {
4210 btf_verifier_log(env, "Invalid section offset");
4213 if (total < secs[i].off) {
4215 btf_verifier_log(env, "Unsupported section found");
4218 if (total > secs[i].off) {
4219 btf_verifier_log(env, "Section overlap found");
4222 if (expected_total - total < secs[i].len) {
4223 btf_verifier_log(env,
4224 "Total section length too long");
4227 total += secs[i].len;
4230 /* There is data other than hdr and known sections */
4231 if (expected_total != total) {
4232 btf_verifier_log(env, "Unsupported section found");
4239 static int btf_parse_hdr(struct btf_verifier_env *env)
4241 u32 hdr_len, hdr_copy, btf_data_size;
4242 const struct btf_header *hdr;
4247 btf_data_size = btf->data_size;
4250 offsetof(struct btf_header, hdr_len) + sizeof(hdr->hdr_len)) {
4251 btf_verifier_log(env, "hdr_len not found");
4256 hdr_len = hdr->hdr_len;
4257 if (btf_data_size < hdr_len) {
4258 btf_verifier_log(env, "btf_header not found");
4262 /* Ensure the unsupported header fields are zero */
4263 if (hdr_len > sizeof(btf->hdr)) {
4264 u8 *expected_zero = btf->data + sizeof(btf->hdr);
4265 u8 *end = btf->data + hdr_len;
4267 for (; expected_zero < end; expected_zero++) {
4268 if (*expected_zero) {
4269 btf_verifier_log(env, "Unsupported btf_header");
4275 hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr));
4276 memcpy(&btf->hdr, btf->data, hdr_copy);
4280 btf_verifier_log_hdr(env, btf_data_size);
4282 if (hdr->magic != BTF_MAGIC) {
4283 btf_verifier_log(env, "Invalid magic");
4287 if (hdr->version != BTF_VERSION) {
4288 btf_verifier_log(env, "Unsupported version");
4293 btf_verifier_log(env, "Unsupported flags");
4297 if (!btf->base_btf && btf_data_size == hdr->hdr_len) {
4298 btf_verifier_log(env, "No data");
4302 err = btf_check_sec_info(env, btf_data_size);
4309 static struct btf *btf_parse(bpfptr_t btf_data, u32 btf_data_size,
4310 u32 log_level, char __user *log_ubuf, u32 log_size)
4312 struct btf_verifier_env *env = NULL;
4313 struct bpf_verifier_log *log;
4314 struct btf *btf = NULL;
4318 if (btf_data_size > BTF_MAX_SIZE)
4319 return ERR_PTR(-E2BIG);
4321 env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
4323 return ERR_PTR(-ENOMEM);
4326 if (log_level || log_ubuf || log_size) {
4327 /* user requested verbose verifier output
4328 * and supplied buffer to store the verification trace
4330 log->level = log_level;
4331 log->ubuf = log_ubuf;
4332 log->len_total = log_size;
4334 /* log attributes have to be sane */
4335 if (log->len_total < 128 || log->len_total > UINT_MAX >> 8 ||
4336 !log->level || !log->ubuf) {
4342 btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN);
4349 data = kvmalloc(btf_data_size, GFP_KERNEL | __GFP_NOWARN);
4356 btf->data_size = btf_data_size;
4358 if (copy_from_bpfptr(data, btf_data, btf_data_size)) {
4363 err = btf_parse_hdr(env);
4367 btf->nohdr_data = btf->data + btf->hdr.hdr_len;
4369 err = btf_parse_str_sec(env);
4373 err = btf_parse_type_sec(env);
4377 if (log->level && bpf_verifier_log_full(log)) {
4382 btf_verifier_env_free(env);
4383 refcount_set(&btf->refcnt, 1);
4387 btf_verifier_env_free(env);
4390 return ERR_PTR(err);
4393 extern char __weak __start_BTF[];
4394 extern char __weak __stop_BTF[];
4395 extern struct btf *btf_vmlinux;
4397 #define BPF_MAP_TYPE(_id, _ops)
4398 #define BPF_LINK_TYPE(_id, _name)
4400 struct bpf_ctx_convert {
4401 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
4402 prog_ctx_type _id##_prog; \
4403 kern_ctx_type _id##_kern;
4404 #include <linux/bpf_types.h>
4405 #undef BPF_PROG_TYPE
4407 /* 't' is written once under lock. Read many times. */
4408 const struct btf_type *t;
4411 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
4413 #include <linux/bpf_types.h>
4414 #undef BPF_PROG_TYPE
4415 __ctx_convert_unused, /* to avoid empty enum in extreme .config */
4417 static u8 bpf_ctx_convert_map[] = {
4418 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
4419 [_id] = __ctx_convert##_id,
4420 #include <linux/bpf_types.h>
4421 #undef BPF_PROG_TYPE
4422 0, /* avoid empty array */
4425 #undef BPF_LINK_TYPE
4427 static const struct btf_member *
4428 btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
4429 const struct btf_type *t, enum bpf_prog_type prog_type,
4432 const struct btf_type *conv_struct;
4433 const struct btf_type *ctx_struct;
4434 const struct btf_member *ctx_type;
4435 const char *tname, *ctx_tname;
4437 conv_struct = bpf_ctx_convert.t;
4439 bpf_log(log, "btf_vmlinux is malformed\n");
4442 t = btf_type_by_id(btf, t->type);
4443 while (btf_type_is_modifier(t))
4444 t = btf_type_by_id(btf, t->type);
4445 if (!btf_type_is_struct(t)) {
4446 /* Only pointer to struct is supported for now.
4447 * That means that BPF_PROG_TYPE_TRACEPOINT with BTF
4448 * is not supported yet.
4449 * BPF_PROG_TYPE_RAW_TRACEPOINT is fine.
4453 tname = btf_name_by_offset(btf, t->name_off);
4455 bpf_log(log, "arg#%d struct doesn't have a name\n", arg);
4458 /* prog_type is valid bpf program type. No need for bounds check. */
4459 ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2;
4460 /* ctx_struct is a pointer to prog_ctx_type in vmlinux.
4461 * Like 'struct __sk_buff'
4463 ctx_struct = btf_type_by_id(btf_vmlinux, ctx_type->type);
4465 /* should not happen */
4467 ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_struct->name_off);
4469 /* should not happen */
4470 bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n");
4473 /* only compare that prog's ctx type name is the same as
4474 * kernel expects. No need to compare field by field.
4475 * It's ok for bpf prog to do:
4476 * struct __sk_buff {};
4477 * int socket_filter_bpf_prog(struct __sk_buff *skb)
4478 * { // no fields of skb are ever used }
4480 if (strcmp(ctx_tname, tname))
4485 static const struct bpf_map_ops * const btf_vmlinux_map_ops[] = {
4486 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
4487 #define BPF_LINK_TYPE(_id, _name)
4488 #define BPF_MAP_TYPE(_id, _ops) \
4490 #include <linux/bpf_types.h>
4491 #undef BPF_PROG_TYPE
4492 #undef BPF_LINK_TYPE
4496 static int btf_vmlinux_map_ids_init(const struct btf *btf,
4497 struct bpf_verifier_log *log)
4499 const struct bpf_map_ops *ops;
4502 for (i = 0; i < ARRAY_SIZE(btf_vmlinux_map_ops); ++i) {
4503 ops = btf_vmlinux_map_ops[i];
4504 if (!ops || (!ops->map_btf_name && !ops->map_btf_id))
4506 if (!ops->map_btf_name || !ops->map_btf_id) {
4507 bpf_log(log, "map type %d is misconfigured\n", i);
4510 btf_id = btf_find_by_name_kind(btf, ops->map_btf_name,
4514 *ops->map_btf_id = btf_id;
4520 static int btf_translate_to_vmlinux(struct bpf_verifier_log *log,
4522 const struct btf_type *t,
4523 enum bpf_prog_type prog_type,
4526 const struct btf_member *prog_ctx_type, *kern_ctx_type;
4528 prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type, arg);
4531 kern_ctx_type = prog_ctx_type + 1;
4532 return kern_ctx_type->type;
4535 BTF_ID_LIST(bpf_ctx_convert_btf_id)
4536 BTF_ID(struct, bpf_ctx_convert)
4538 struct btf *btf_parse_vmlinux(void)
4540 struct btf_verifier_env *env = NULL;
4541 struct bpf_verifier_log *log;
4542 struct btf *btf = NULL;
4545 env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
4547 return ERR_PTR(-ENOMEM);
4550 log->level = BPF_LOG_KERNEL;
4552 btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN);
4559 btf->data = __start_BTF;
4560 btf->data_size = __stop_BTF - __start_BTF;
4561 btf->kernel_btf = true;
4562 snprintf(btf->name, sizeof(btf->name), "vmlinux");
4564 err = btf_parse_hdr(env);
4568 btf->nohdr_data = btf->data + btf->hdr.hdr_len;
4570 err = btf_parse_str_sec(env);
4574 err = btf_check_all_metas(env);
4578 /* btf_parse_vmlinux() runs under bpf_verifier_lock */
4579 bpf_ctx_convert.t = btf_type_by_id(btf, bpf_ctx_convert_btf_id[0]);
4581 /* find bpf map structs for map_ptr access checking */
4582 err = btf_vmlinux_map_ids_init(btf, log);
4586 bpf_struct_ops_init(btf, log);
4588 refcount_set(&btf->refcnt, 1);
4590 err = btf_alloc_id(btf);
4594 btf_verifier_env_free(env);
4598 btf_verifier_env_free(env);
4603 return ERR_PTR(err);
4606 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
4608 static struct btf *btf_parse_module(const char *module_name, const void *data, unsigned int data_size)
4610 struct btf_verifier_env *env = NULL;
4611 struct bpf_verifier_log *log;
4612 struct btf *btf = NULL, *base_btf;
4615 base_btf = bpf_get_btf_vmlinux();
4616 if (IS_ERR(base_btf))
4619 return ERR_PTR(-EINVAL);
4621 env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
4623 return ERR_PTR(-ENOMEM);
4626 log->level = BPF_LOG_KERNEL;
4628 btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN);
4635 btf->base_btf = base_btf;
4636 btf->start_id = base_btf->nr_types;
4637 btf->start_str_off = base_btf->hdr.str_len;
4638 btf->kernel_btf = true;
4639 snprintf(btf->name, sizeof(btf->name), "%s", module_name);
4641 btf->data = kvmalloc(data_size, GFP_KERNEL | __GFP_NOWARN);
4646 memcpy(btf->data, data, data_size);
4647 btf->data_size = data_size;
4649 err = btf_parse_hdr(env);
4653 btf->nohdr_data = btf->data + btf->hdr.hdr_len;
4655 err = btf_parse_str_sec(env);
4659 err = btf_check_all_metas(env);
4663 btf_verifier_env_free(env);
4664 refcount_set(&btf->refcnt, 1);
4668 btf_verifier_env_free(env);
4674 return ERR_PTR(err);
4677 #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */
4679 struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog)
4681 struct bpf_prog *tgt_prog = prog->aux->dst_prog;
4684 return tgt_prog->aux->btf;
4686 return prog->aux->attach_btf;
4689 static bool is_string_ptr(struct btf *btf, const struct btf_type *t)
4691 /* t comes in already as a pointer */
4692 t = btf_type_by_id(btf, t->type);
4695 if (BTF_INFO_KIND(t->info) == BTF_KIND_CONST)
4696 t = btf_type_by_id(btf, t->type);
4698 /* char, signed char, unsigned char */
4699 return btf_type_is_int(t) && t->size == 1;
4702 bool btf_ctx_access(int off, int size, enum bpf_access_type type,
4703 const struct bpf_prog *prog,
4704 struct bpf_insn_access_aux *info)
4706 const struct btf_type *t = prog->aux->attach_func_proto;
4707 struct bpf_prog *tgt_prog = prog->aux->dst_prog;
4708 struct btf *btf = bpf_prog_get_target_btf(prog);
4709 const char *tname = prog->aux->attach_func_name;
4710 struct bpf_verifier_log *log = info->log;
4711 const struct btf_param *args;
4716 bpf_log(log, "func '%s' offset %d is not multiple of 8\n",
4721 args = (const struct btf_param *)(t + 1);
4722 /* if (t == NULL) Fall back to default BPF prog with
4723 * MAX_BPF_FUNC_REG_ARGS u64 arguments.
4725 nr_args = t ? btf_type_vlen(t) : MAX_BPF_FUNC_REG_ARGS;
4726 if (prog->aux->attach_btf_trace) {
4727 /* skip first 'void *__data' argument in btf_trace_##name typedef */
4732 if (arg > nr_args) {
4733 bpf_log(log, "func '%s' doesn't have %d-th argument\n",
4738 if (arg == nr_args) {
4739 switch (prog->expected_attach_type) {
4741 case BPF_TRACE_FEXIT:
4742 /* When LSM programs are attached to void LSM hooks
4743 * they use FEXIT trampolines and when attached to
4744 * int LSM hooks, they use MODIFY_RETURN trampolines.
4746 * While the LSM programs are BPF_MODIFY_RETURN-like
4749 * if (ret_type != 'int')
4752 * is _not_ done here. This is still safe as LSM hooks
4753 * have only void and int return types.
4757 t = btf_type_by_id(btf, t->type);
4759 case BPF_MODIFY_RETURN:
4760 /* For now the BPF_MODIFY_RETURN can only be attached to
4761 * functions that return an int.
4766 t = btf_type_skip_modifiers(btf, t->type, NULL);
4767 if (!btf_type_is_small_int(t)) {
4769 "ret type %s not allowed for fmod_ret\n",
4770 btf_kind_str[BTF_INFO_KIND(t->info)]);
4775 bpf_log(log, "func '%s' doesn't have %d-th argument\n",
4781 /* Default prog with MAX_BPF_FUNC_REG_ARGS args */
4783 t = btf_type_by_id(btf, args[arg].type);
4786 /* skip modifiers */
4787 while (btf_type_is_modifier(t))
4788 t = btf_type_by_id(btf, t->type);
4789 if (btf_type_is_small_int(t) || btf_type_is_enum(t))
4790 /* accessing a scalar */
4792 if (!btf_type_is_ptr(t)) {
4794 "func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n",
4796 __btf_name_by_offset(btf, t->name_off),
4797 btf_kind_str[BTF_INFO_KIND(t->info)]);
4801 /* check for PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL */
4802 for (i = 0; i < prog->aux->ctx_arg_info_size; i++) {
4803 const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i];
4805 if (ctx_arg_info->offset == off &&
4806 (ctx_arg_info->reg_type == PTR_TO_RDONLY_BUF_OR_NULL ||
4807 ctx_arg_info->reg_type == PTR_TO_RDWR_BUF_OR_NULL)) {
4808 info->reg_type = ctx_arg_info->reg_type;
4814 /* This is a pointer to void.
4815 * It is the same as scalar from the verifier safety pov.
4816 * No further pointer walking is allowed.
4820 if (is_string_ptr(btf, t))
4823 /* this is a pointer to another type */
4824 for (i = 0; i < prog->aux->ctx_arg_info_size; i++) {
4825 const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i];
4827 if (ctx_arg_info->offset == off) {
4828 if (!ctx_arg_info->btf_id) {
4829 bpf_log(log,"invalid btf_id for context argument offset %u\n", off);
4833 info->reg_type = ctx_arg_info->reg_type;
4834 info->btf = btf_vmlinux;
4835 info->btf_id = ctx_arg_info->btf_id;
4840 info->reg_type = PTR_TO_BTF_ID;
4842 enum bpf_prog_type tgt_type;
4844 if (tgt_prog->type == BPF_PROG_TYPE_EXT)
4845 tgt_type = tgt_prog->aux->saved_dst_prog_type;
4847 tgt_type = tgt_prog->type;
4849 ret = btf_translate_to_vmlinux(log, btf, t, tgt_type, arg);
4851 info->btf = btf_vmlinux;
4860 info->btf_id = t->type;
4861 t = btf_type_by_id(btf, t->type);
4862 /* skip modifiers */
4863 while (btf_type_is_modifier(t)) {
4864 info->btf_id = t->type;
4865 t = btf_type_by_id(btf, t->type);
4867 if (!btf_type_is_struct(t)) {
4869 "func '%s' arg%d type %s is not a struct\n",
4870 tname, arg, btf_kind_str[BTF_INFO_KIND(t->info)]);
4873 bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n",
4874 tname, arg, info->btf_id, btf_kind_str[BTF_INFO_KIND(t->info)],
4875 __btf_name_by_offset(btf, t->name_off));
4879 enum bpf_struct_walk_result {
4886 static int btf_struct_walk(struct bpf_verifier_log *log, const struct btf *btf,
4887 const struct btf_type *t, int off, int size,
4890 u32 i, moff, mtrue_end, msize = 0, total_nelems = 0;
4891 const struct btf_type *mtype, *elem_type = NULL;
4892 const struct btf_member *member;
4893 const char *tname, *mname;
4894 u32 vlen, elem_id, mid;
4897 tname = __btf_name_by_offset(btf, t->name_off);
4898 if (!btf_type_is_struct(t)) {
4899 bpf_log(log, "Type '%s' is not a struct\n", tname);
4903 vlen = btf_type_vlen(t);
4904 if (off + size > t->size) {
4905 /* If the last element is a variable size array, we may
4906 * need to relax the rule.
4908 struct btf_array *array_elem;
4913 member = btf_type_member(t) + vlen - 1;
4914 mtype = btf_type_skip_modifiers(btf, member->type,
4916 if (!btf_type_is_array(mtype))
4919 array_elem = (struct btf_array *)(mtype + 1);
4920 if (array_elem->nelems != 0)
4923 moff = btf_member_bit_offset(t, member) / 8;
4927 /* Only allow structure for now, can be relaxed for
4928 * other types later.
4930 t = btf_type_skip_modifiers(btf, array_elem->type,
4932 if (!btf_type_is_struct(t))
4935 off = (off - moff) % t->size;
4939 bpf_log(log, "access beyond struct %s at off %u size %u\n",
4944 for_each_member(i, t, member) {
4945 /* offset of the field in bytes */
4946 moff = btf_member_bit_offset(t, member) / 8;
4947 if (off + size <= moff)
4948 /* won't find anything, field is already too far */
4951 if (btf_member_bitfield_size(t, member)) {
4952 u32 end_bit = btf_member_bit_offset(t, member) +
4953 btf_member_bitfield_size(t, member);
4955 /* off <= moff instead of off == moff because clang
4956 * does not generate a BTF member for anonymous
4957 * bitfield like the ":16" here:
4964 BITS_ROUNDUP_BYTES(end_bit) <= off + size)
4967 /* off may be accessing a following member
4971 * Doing partial access at either end of this
4972 * bitfield. Continue on this case also to
4973 * treat it as not accessing this bitfield
4974 * and eventually error out as field not
4975 * found to keep it simple.
4976 * It could be relaxed if there was a legit
4977 * partial access case later.
4982 /* In case of "off" is pointing to holes of a struct */
4986 /* type of the field */
4988 mtype = btf_type_by_id(btf, member->type);
4989 mname = __btf_name_by_offset(btf, member->name_off);
4991 mtype = __btf_resolve_size(btf, mtype, &msize,
4992 &elem_type, &elem_id, &total_nelems,
4994 if (IS_ERR(mtype)) {
4995 bpf_log(log, "field %s doesn't have size\n", mname);
4999 mtrue_end = moff + msize;
5000 if (off >= mtrue_end)
5001 /* no overlap with member, keep iterating */
5004 if (btf_type_is_array(mtype)) {
5007 /* __btf_resolve_size() above helps to
5008 * linearize a multi-dimensional array.
5010 * The logic here is treating an array
5011 * in a struct as the following way:
5014 * struct inner array[2][2];
5020 * struct inner array_elem0;
5021 * struct inner array_elem1;
5022 * struct inner array_elem2;
5023 * struct inner array_elem3;
5026 * When accessing outer->array[1][0], it moves
5027 * moff to "array_elem2", set mtype to
5028 * "struct inner", and msize also becomes
5029 * sizeof(struct inner). Then most of the
5030 * remaining logic will fall through without
5031 * caring the current member is an array or
5034 * Unlike mtype/msize/moff, mtrue_end does not
5035 * change. The naming difference ("_true") tells
5036 * that it is not always corresponding to
5037 * the current mtype/msize/moff.
5038 * It is the true end of the current
5039 * member (i.e. array in this case). That
5040 * will allow an int array to be accessed like
5042 * i.e. allow access beyond the size of
5043 * the array's element as long as it is
5044 * within the mtrue_end boundary.
5047 /* skip empty array */
5048 if (moff == mtrue_end)
5051 msize /= total_nelems;
5052 elem_idx = (off - moff) / msize;
5053 moff += elem_idx * msize;
5058 /* the 'off' we're looking for is either equal to start
5059 * of this field or inside of this struct
5061 if (btf_type_is_struct(mtype)) {
5062 /* our field must be inside that union or struct */
5065 /* return if the offset matches the member offset */
5071 /* adjust offset we're looking for */
5076 if (btf_type_is_ptr(mtype)) {
5077 const struct btf_type *stype;
5080 if (msize != size || off != moff) {
5082 "cannot access ptr member %s with moff %u in struct %s with off %u size %u\n",
5083 mname, moff, tname, off, size);
5086 stype = btf_type_skip_modifiers(btf, mtype->type, &id);
5087 if (btf_type_is_struct(stype)) {
5093 /* Allow more flexible access within an int as long as
5094 * it is within mtrue_end.
5095 * Since mtrue_end could be the end of an array,
5096 * that also allows using an array of int as a scratch
5097 * space. e.g. skb->cb[].
5099 if (off + size > mtrue_end) {
5101 "access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n",
5102 mname, mtrue_end, tname, off, size);
5108 bpf_log(log, "struct %s doesn't have field at offset %d\n", tname, off);
5112 int btf_struct_access(struct bpf_verifier_log *log, const struct btf *btf,
5113 const struct btf_type *t, int off, int size,
5114 enum bpf_access_type atype __maybe_unused,
5121 err = btf_struct_walk(log, btf, t, off, size, &id);
5125 /* If we found the pointer or scalar on t+off,
5129 return PTR_TO_BTF_ID;
5131 return SCALAR_VALUE;
5133 /* We found nested struct, so continue the search
5134 * by diving in it. At this point the offset is
5135 * aligned with the new type, so set it to 0.
5137 t = btf_type_by_id(btf, id);
5141 /* It's either error or unknown return value..
5144 if (WARN_ONCE(err > 0, "unknown btf_struct_walk return value"))
5153 /* Check that two BTF types, each specified as an BTF object + id, are exactly
5154 * the same. Trivial ID check is not enough due to module BTFs, because we can
5155 * end up with two different module BTFs, but IDs point to the common type in
5158 static bool btf_types_are_same(const struct btf *btf1, u32 id1,
5159 const struct btf *btf2, u32 id2)
5165 return btf_type_by_id(btf1, id1) == btf_type_by_id(btf2, id2);
5168 bool btf_struct_ids_match(struct bpf_verifier_log *log,
5169 const struct btf *btf, u32 id, int off,
5170 const struct btf *need_btf, u32 need_type_id)
5172 const struct btf_type *type;
5175 /* Are we already done? */
5176 if (off == 0 && btf_types_are_same(btf, id, need_btf, need_type_id))
5180 type = btf_type_by_id(btf, id);
5183 err = btf_struct_walk(log, btf, type, off, 1, &id);
5184 if (err != WALK_STRUCT)
5187 /* We found nested struct object. If it matches
5188 * the requested ID, we're done. Otherwise let's
5189 * continue the search with offset 0 in the new
5192 if (!btf_types_are_same(btf, id, need_btf, need_type_id)) {
5200 static int __get_type_size(struct btf *btf, u32 btf_id,
5201 const struct btf_type **bad_type)
5203 const struct btf_type *t;
5208 t = btf_type_by_id(btf, btf_id);
5209 while (t && btf_type_is_modifier(t))
5210 t = btf_type_by_id(btf, t->type);
5212 *bad_type = btf_type_by_id(btf, 0);
5215 if (btf_type_is_ptr(t))
5216 /* kernel size of pointer. Not BPF's size of pointer*/
5217 return sizeof(void *);
5218 if (btf_type_is_int(t) || btf_type_is_enum(t))
5224 int btf_distill_func_proto(struct bpf_verifier_log *log,
5226 const struct btf_type *func,
5228 struct btf_func_model *m)
5230 const struct btf_param *args;
5231 const struct btf_type *t;
5236 /* BTF function prototype doesn't match the verifier types.
5237 * Fall back to MAX_BPF_FUNC_REG_ARGS u64 args.
5239 for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++)
5242 m->nr_args = MAX_BPF_FUNC_REG_ARGS;
5245 args = (const struct btf_param *)(func + 1);
5246 nargs = btf_type_vlen(func);
5247 if (nargs >= MAX_BPF_FUNC_ARGS) {
5249 "The function %s has %d arguments. Too many.\n",
5253 ret = __get_type_size(btf, func->type, &t);
5256 "The function %s return type %s is unsupported.\n",
5257 tname, btf_kind_str[BTF_INFO_KIND(t->info)]);
5262 for (i = 0; i < nargs; i++) {
5263 if (i == nargs - 1 && args[i].type == 0) {
5265 "The function %s with variable args is unsupported.\n",
5269 ret = __get_type_size(btf, args[i].type, &t);
5272 "The function %s arg%d type %s is unsupported.\n",
5273 tname, i, btf_kind_str[BTF_INFO_KIND(t->info)]);
5278 "The function %s has malformed void argument.\n",
5282 m->arg_size[i] = ret;
5288 /* Compare BTFs of two functions assuming only scalars and pointers to context.
5289 * t1 points to BTF_KIND_FUNC in btf1
5290 * t2 points to BTF_KIND_FUNC in btf2
5292 * EINVAL - function prototype mismatch
5293 * EFAULT - verifier bug
5294 * 0 - 99% match. The last 1% is validated by the verifier.
5296 static int btf_check_func_type_match(struct bpf_verifier_log *log,
5297 struct btf *btf1, const struct btf_type *t1,
5298 struct btf *btf2, const struct btf_type *t2)
5300 const struct btf_param *args1, *args2;
5301 const char *fn1, *fn2, *s1, *s2;
5302 u32 nargs1, nargs2, i;
5304 fn1 = btf_name_by_offset(btf1, t1->name_off);
5305 fn2 = btf_name_by_offset(btf2, t2->name_off);
5307 if (btf_func_linkage(t1) != BTF_FUNC_GLOBAL) {
5308 bpf_log(log, "%s() is not a global function\n", fn1);
5311 if (btf_func_linkage(t2) != BTF_FUNC_GLOBAL) {
5312 bpf_log(log, "%s() is not a global function\n", fn2);
5316 t1 = btf_type_by_id(btf1, t1->type);
5317 if (!t1 || !btf_type_is_func_proto(t1))
5319 t2 = btf_type_by_id(btf2, t2->type);
5320 if (!t2 || !btf_type_is_func_proto(t2))
5323 args1 = (const struct btf_param *)(t1 + 1);
5324 nargs1 = btf_type_vlen(t1);
5325 args2 = (const struct btf_param *)(t2 + 1);
5326 nargs2 = btf_type_vlen(t2);
5328 if (nargs1 != nargs2) {
5329 bpf_log(log, "%s() has %d args while %s() has %d args\n",
5330 fn1, nargs1, fn2, nargs2);
5334 t1 = btf_type_skip_modifiers(btf1, t1->type, NULL);
5335 t2 = btf_type_skip_modifiers(btf2, t2->type, NULL);
5336 if (t1->info != t2->info) {
5338 "Return type %s of %s() doesn't match type %s of %s()\n",
5339 btf_type_str(t1), fn1,
5340 btf_type_str(t2), fn2);
5344 for (i = 0; i < nargs1; i++) {
5345 t1 = btf_type_skip_modifiers(btf1, args1[i].type, NULL);
5346 t2 = btf_type_skip_modifiers(btf2, args2[i].type, NULL);
5348 if (t1->info != t2->info) {
5349 bpf_log(log, "arg%d in %s() is %s while %s() has %s\n",
5350 i, fn1, btf_type_str(t1),
5351 fn2, btf_type_str(t2));
5354 if (btf_type_has_size(t1) && t1->size != t2->size) {
5356 "arg%d in %s() has size %d while %s() has %d\n",
5362 /* global functions are validated with scalars and pointers
5363 * to context only. And only global functions can be replaced.
5364 * Hence type check only those types.
5366 if (btf_type_is_int(t1) || btf_type_is_enum(t1))
5368 if (!btf_type_is_ptr(t1)) {
5370 "arg%d in %s() has unrecognized type\n",
5374 t1 = btf_type_skip_modifiers(btf1, t1->type, NULL);
5375 t2 = btf_type_skip_modifiers(btf2, t2->type, NULL);
5376 if (!btf_type_is_struct(t1)) {
5378 "arg%d in %s() is not a pointer to context\n",
5382 if (!btf_type_is_struct(t2)) {
5384 "arg%d in %s() is not a pointer to context\n",
5388 /* This is an optional check to make program writing easier.
5389 * Compare names of structs and report an error to the user.
5390 * btf_prepare_func_args() already checked that t2 struct
5391 * is a context type. btf_prepare_func_args() will check
5392 * later that t1 struct is a context type as well.
5394 s1 = btf_name_by_offset(btf1, t1->name_off);
5395 s2 = btf_name_by_offset(btf2, t2->name_off);
5396 if (strcmp(s1, s2)) {
5398 "arg%d %s(struct %s *) doesn't match %s(struct %s *)\n",
5399 i, fn1, s1, fn2, s2);
5406 /* Compare BTFs of given program with BTF of target program */
5407 int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog,
5408 struct btf *btf2, const struct btf_type *t2)
5410 struct btf *btf1 = prog->aux->btf;
5411 const struct btf_type *t1;
5414 if (!prog->aux->func_info) {
5415 bpf_log(log, "Program extension requires BTF\n");
5419 btf_id = prog->aux->func_info[0].type_id;
5423 t1 = btf_type_by_id(btf1, btf_id);
5424 if (!t1 || !btf_type_is_func(t1))
5427 return btf_check_func_type_match(log, btf1, t1, btf2, t2);
5430 static u32 *reg2btf_ids[__BPF_REG_TYPE_MAX] = {
5432 [PTR_TO_SOCKET] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK],
5433 [PTR_TO_SOCK_COMMON] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON],
5434 [PTR_TO_TCP_SOCK] = &btf_sock_ids[BTF_SOCK_TYPE_TCP],
5438 static int btf_check_func_arg_match(struct bpf_verifier_env *env,
5439 const struct btf *btf, u32 func_id,
5440 struct bpf_reg_state *regs,
5443 struct bpf_verifier_log *log = &env->log;
5444 const char *func_name, *ref_tname;
5445 const struct btf_type *t, *ref_t;
5446 const struct btf_param *args;
5447 u32 i, nargs, ref_id;
5449 t = btf_type_by_id(btf, func_id);
5450 if (!t || !btf_type_is_func(t)) {
5451 /* These checks were already done by the verifier while loading
5452 * struct bpf_func_info or in add_kfunc_call().
5454 bpf_log(log, "BTF of func_id %u doesn't point to KIND_FUNC\n",
5458 func_name = btf_name_by_offset(btf, t->name_off);
5460 t = btf_type_by_id(btf, t->type);
5461 if (!t || !btf_type_is_func_proto(t)) {
5462 bpf_log(log, "Invalid BTF of func %s\n", func_name);
5465 args = (const struct btf_param *)(t + 1);
5466 nargs = btf_type_vlen(t);
5467 if (nargs > MAX_BPF_FUNC_REG_ARGS) {
5468 bpf_log(log, "Function %s has %d > %d args\n", func_name, nargs,
5469 MAX_BPF_FUNC_REG_ARGS);
5473 /* check that BTF function arguments match actual types that the
5476 for (i = 0; i < nargs; i++) {
5478 struct bpf_reg_state *reg = ®s[regno];
5480 t = btf_type_skip_modifiers(btf, args[i].type, NULL);
5481 if (btf_type_is_scalar(t)) {
5482 if (reg->type == SCALAR_VALUE)
5484 bpf_log(log, "R%d is not a scalar\n", regno);
5488 if (!btf_type_is_ptr(t)) {
5489 bpf_log(log, "Unrecognized arg#%d type %s\n",
5490 i, btf_type_str(t));
5494 ref_t = btf_type_skip_modifiers(btf, t->type, &ref_id);
5495 ref_tname = btf_name_by_offset(btf, ref_t->name_off);
5496 if (btf_is_kernel(btf)) {
5497 const struct btf_type *reg_ref_t;
5498 const struct btf *reg_btf;
5499 const char *reg_ref_tname;
5502 if (!btf_type_is_struct(ref_t)) {
5503 bpf_log(log, "kernel function %s args#%d pointer type %s %s is not supported\n",
5504 func_name, i, btf_type_str(ref_t),
5509 if (reg->type == PTR_TO_BTF_ID) {
5511 reg_ref_id = reg->btf_id;
5512 } else if (reg2btf_ids[reg->type]) {
5513 reg_btf = btf_vmlinux;
5514 reg_ref_id = *reg2btf_ids[reg->type];
5516 bpf_log(log, "kernel function %s args#%d expected pointer to %s %s but R%d is not a pointer to btf_id\n",
5518 btf_type_str(ref_t), ref_tname, regno);
5522 reg_ref_t = btf_type_skip_modifiers(reg_btf, reg_ref_id,
5524 reg_ref_tname = btf_name_by_offset(reg_btf,
5525 reg_ref_t->name_off);
5526 if (!btf_struct_ids_match(log, reg_btf, reg_ref_id,
5527 reg->off, btf, ref_id)) {
5528 bpf_log(log, "kernel function %s args#%d expected pointer to %s %s but R%d has a pointer to %s %s\n",
5530 btf_type_str(ref_t), ref_tname,
5531 regno, btf_type_str(reg_ref_t),
5535 } else if (btf_get_prog_ctx_type(log, btf, t,
5536 env->prog->type, i)) {
5537 /* If function expects ctx type in BTF check that caller
5538 * is passing PTR_TO_CTX.
5540 if (reg->type != PTR_TO_CTX) {
5542 "arg#%d expected pointer to ctx, but got %s\n",
5543 i, btf_type_str(t));
5546 if (check_ctx_reg(env, reg, regno))
5548 } else if (ptr_to_mem_ok) {
5549 const struct btf_type *resolve_ret;
5552 resolve_ret = btf_resolve_size(btf, ref_t, &type_size);
5553 if (IS_ERR(resolve_ret)) {
5555 "arg#%d reference type('%s %s') size cannot be determined: %ld\n",
5556 i, btf_type_str(ref_t), ref_tname,
5557 PTR_ERR(resolve_ret));
5561 if (check_mem_reg(env, reg, regno, type_size))
5571 /* Compare BTF of a function with given bpf_reg_state.
5573 * EFAULT - there is a verifier bug. Abort verification.
5574 * EINVAL - there is a type mismatch or BTF is not available.
5575 * 0 - BTF matches with what bpf_reg_state expects.
5576 * Only PTR_TO_CTX and SCALAR_VALUE states are recognized.
5578 int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog,
5579 struct bpf_reg_state *regs)
5581 struct bpf_prog *prog = env->prog;
5582 struct btf *btf = prog->aux->btf;
5587 if (!prog->aux->func_info)
5590 btf_id = prog->aux->func_info[subprog].type_id;
5594 if (prog->aux->func_info_aux[subprog].unreliable)
5597 is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL;
5598 err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global);
5600 /* Compiler optimizations can remove arguments from static functions
5601 * or mismatched type can be passed into a global function.
5602 * In such cases mark the function as unreliable from BTF point of view.
5605 prog->aux->func_info_aux[subprog].unreliable = true;
5609 int btf_check_kfunc_arg_match(struct bpf_verifier_env *env,
5610 const struct btf *btf, u32 func_id,
5611 struct bpf_reg_state *regs)
5613 return btf_check_func_arg_match(env, btf, func_id, regs, false);
5616 /* Convert BTF of a function into bpf_reg_state if possible
5618 * EFAULT - there is a verifier bug. Abort verification.
5619 * EINVAL - cannot convert BTF.
5620 * 0 - Successfully converted BTF into bpf_reg_state
5621 * (either PTR_TO_CTX or SCALAR_VALUE).
5623 int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
5624 struct bpf_reg_state *regs)
5626 struct bpf_verifier_log *log = &env->log;
5627 struct bpf_prog *prog = env->prog;
5628 enum bpf_prog_type prog_type = prog->type;
5629 struct btf *btf = prog->aux->btf;
5630 const struct btf_param *args;
5631 const struct btf_type *t, *ref_t;
5632 u32 i, nargs, btf_id;
5635 if (!prog->aux->func_info ||
5636 prog->aux->func_info_aux[subprog].linkage != BTF_FUNC_GLOBAL) {
5637 bpf_log(log, "Verifier bug\n");
5641 btf_id = prog->aux->func_info[subprog].type_id;
5643 bpf_log(log, "Global functions need valid BTF\n");
5647 t = btf_type_by_id(btf, btf_id);
5648 if (!t || !btf_type_is_func(t)) {
5649 /* These checks were already done by the verifier while loading
5650 * struct bpf_func_info
5652 bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n",
5656 tname = btf_name_by_offset(btf, t->name_off);
5658 if (log->level & BPF_LOG_LEVEL)
5659 bpf_log(log, "Validating %s() func#%d...\n",
5662 if (prog->aux->func_info_aux[subprog].unreliable) {
5663 bpf_log(log, "Verifier bug in function %s()\n", tname);
5666 if (prog_type == BPF_PROG_TYPE_EXT)
5667 prog_type = prog->aux->dst_prog->type;
5669 t = btf_type_by_id(btf, t->type);
5670 if (!t || !btf_type_is_func_proto(t)) {
5671 bpf_log(log, "Invalid type of function %s()\n", tname);
5674 args = (const struct btf_param *)(t + 1);
5675 nargs = btf_type_vlen(t);
5676 if (nargs > MAX_BPF_FUNC_REG_ARGS) {
5677 bpf_log(log, "Global function %s() with %d > %d args. Buggy compiler.\n",
5678 tname, nargs, MAX_BPF_FUNC_REG_ARGS);
5681 /* check that function returns int */
5682 t = btf_type_by_id(btf, t->type);
5683 while (btf_type_is_modifier(t))
5684 t = btf_type_by_id(btf, t->type);
5685 if (!btf_type_is_int(t) && !btf_type_is_enum(t)) {
5687 "Global function %s() doesn't return scalar. Only those are supported.\n",
5691 /* Convert BTF function arguments into verifier types.
5692 * Only PTR_TO_CTX and SCALAR are supported atm.
5694 for (i = 0; i < nargs; i++) {
5695 struct bpf_reg_state *reg = ®s[i + 1];
5697 t = btf_type_by_id(btf, args[i].type);
5698 while (btf_type_is_modifier(t))
5699 t = btf_type_by_id(btf, t->type);
5700 if (btf_type_is_int(t) || btf_type_is_enum(t)) {
5701 reg->type = SCALAR_VALUE;
5704 if (btf_type_is_ptr(t)) {
5705 if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) {
5706 reg->type = PTR_TO_CTX;
5710 t = btf_type_skip_modifiers(btf, t->type, NULL);
5712 ref_t = btf_resolve_size(btf, t, ®->mem_size);
5713 if (IS_ERR(ref_t)) {
5715 "arg#%d reference type('%s %s') size cannot be determined: %ld\n",
5716 i, btf_type_str(t), btf_name_by_offset(btf, t->name_off),
5721 reg->type = PTR_TO_MEM_OR_NULL;
5722 reg->id = ++env->id_gen;
5726 bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n",
5727 i, btf_kind_str[BTF_INFO_KIND(t->info)], tname);
5733 static void btf_type_show(const struct btf *btf, u32 type_id, void *obj,
5734 struct btf_show *show)
5736 const struct btf_type *t = btf_type_by_id(btf, type_id);
5739 memset(&show->state, 0, sizeof(show->state));
5740 memset(&show->obj, 0, sizeof(show->obj));
5742 btf_type_ops(t)->show(btf, t, type_id, obj, 0, show);
5745 static void btf_seq_show(struct btf_show *show, const char *fmt,
5748 seq_vprintf((struct seq_file *)show->target, fmt, args);
5751 int btf_type_seq_show_flags(const struct btf *btf, u32 type_id,
5752 void *obj, struct seq_file *m, u64 flags)
5754 struct btf_show sseq;
5757 sseq.showfn = btf_seq_show;
5760 btf_type_show(btf, type_id, obj, &sseq);
5762 return sseq.state.status;
5765 void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
5768 (void) btf_type_seq_show_flags(btf, type_id, obj, m,
5769 BTF_SHOW_NONAME | BTF_SHOW_COMPACT |
5770 BTF_SHOW_ZERO | BTF_SHOW_UNSAFE);
5773 struct btf_show_snprintf {
5774 struct btf_show show;
5775 int len_left; /* space left in string */
5776 int len; /* length we would have written */
5779 static void btf_snprintf_show(struct btf_show *show, const char *fmt,
5782 struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show;
5785 len = vsnprintf(show->target, ssnprintf->len_left, fmt, args);
5788 ssnprintf->len_left = 0;
5789 ssnprintf->len = len;
5790 } else if (len > ssnprintf->len_left) {
5791 /* no space, drive on to get length we would have written */
5792 ssnprintf->len_left = 0;
5793 ssnprintf->len += len;
5795 ssnprintf->len_left -= len;
5796 ssnprintf->len += len;
5797 show->target += len;
5801 int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj,
5802 char *buf, int len, u64 flags)
5804 struct btf_show_snprintf ssnprintf;
5806 ssnprintf.show.target = buf;
5807 ssnprintf.show.flags = flags;
5808 ssnprintf.show.showfn = btf_snprintf_show;
5809 ssnprintf.len_left = len;
5812 btf_type_show(btf, type_id, obj, (struct btf_show *)&ssnprintf);
5814 /* If we encontered an error, return it. */
5815 if (ssnprintf.show.state.status)
5816 return ssnprintf.show.state.status;
5818 /* Otherwise return length we would have written */
5819 return ssnprintf.len;
5822 #ifdef CONFIG_PROC_FS
5823 static void bpf_btf_show_fdinfo(struct seq_file *m, struct file *filp)
5825 const struct btf *btf = filp->private_data;
5827 seq_printf(m, "btf_id:\t%u\n", btf->id);
5831 static int btf_release(struct inode *inode, struct file *filp)
5833 btf_put(filp->private_data);
5837 const struct file_operations btf_fops = {
5838 #ifdef CONFIG_PROC_FS
5839 .show_fdinfo = bpf_btf_show_fdinfo,
5841 .release = btf_release,
5844 static int __btf_new_fd(struct btf *btf)
5846 return anon_inode_getfd("btf", &btf_fops, btf, O_RDONLY | O_CLOEXEC);
5849 int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr)
5854 btf = btf_parse(make_bpfptr(attr->btf, uattr.is_kernel),
5855 attr->btf_size, attr->btf_log_level,
5856 u64_to_user_ptr(attr->btf_log_buf),
5857 attr->btf_log_size);
5859 return PTR_ERR(btf);
5861 ret = btf_alloc_id(btf);
5868 * The BTF ID is published to the userspace.
5869 * All BTF free must go through call_rcu() from
5870 * now on (i.e. free by calling btf_put()).
5873 ret = __btf_new_fd(btf);
5880 struct btf *btf_get_by_fd(int fd)
5888 return ERR_PTR(-EBADF);
5890 if (f.file->f_op != &btf_fops) {
5892 return ERR_PTR(-EINVAL);
5895 btf = f.file->private_data;
5896 refcount_inc(&btf->refcnt);
5902 int btf_get_info_by_fd(const struct btf *btf,
5903 const union bpf_attr *attr,
5904 union bpf_attr __user *uattr)
5906 struct bpf_btf_info __user *uinfo;
5907 struct bpf_btf_info info;
5908 u32 info_copy, btf_copy;
5911 u32 uinfo_len, uname_len, name_len;
5914 uinfo = u64_to_user_ptr(attr->info.info);
5915 uinfo_len = attr->info.info_len;
5917 info_copy = min_t(u32, uinfo_len, sizeof(info));
5918 memset(&info, 0, sizeof(info));
5919 if (copy_from_user(&info, uinfo, info_copy))
5923 ubtf = u64_to_user_ptr(info.btf);
5924 btf_copy = min_t(u32, btf->data_size, info.btf_size);
5925 if (copy_to_user(ubtf, btf->data, btf_copy))
5927 info.btf_size = btf->data_size;
5929 info.kernel_btf = btf->kernel_btf;
5931 uname = u64_to_user_ptr(info.name);
5932 uname_len = info.name_len;
5933 if (!uname ^ !uname_len)
5936 name_len = strlen(btf->name);
5937 info.name_len = name_len;
5940 if (uname_len >= name_len + 1) {
5941 if (copy_to_user(uname, btf->name, name_len + 1))
5946 if (copy_to_user(uname, btf->name, uname_len - 1))
5948 if (put_user(zero, uname + uname_len - 1))
5950 /* let user-space know about too short buffer */
5955 if (copy_to_user(uinfo, &info, info_copy) ||
5956 put_user(info_copy, &uattr->info.info_len))
5962 int btf_get_fd_by_id(u32 id)
5968 btf = idr_find(&btf_idr, id);
5969 if (!btf || !refcount_inc_not_zero(&btf->refcnt))
5970 btf = ERR_PTR(-ENOENT);
5974 return PTR_ERR(btf);
5976 fd = __btf_new_fd(btf);
5983 u32 btf_obj_id(const struct btf *btf)
5988 bool btf_is_kernel(const struct btf *btf)
5990 return btf->kernel_btf;
5993 bool btf_is_module(const struct btf *btf)
5995 return btf->kernel_btf && strcmp(btf->name, "vmlinux") != 0;
5998 static int btf_id_cmp_func(const void *a, const void *b)
6000 const int *pa = a, *pb = b;
6005 bool btf_id_set_contains(const struct btf_id_set *set, u32 id)
6007 return bsearch(&id, set->ids, set->cnt, sizeof(u32), btf_id_cmp_func) != NULL;
6010 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
6012 struct list_head list;
6013 struct module *module;
6015 struct bin_attribute *sysfs_attr;
6018 static LIST_HEAD(btf_modules);
6019 static DEFINE_MUTEX(btf_module_mutex);
6022 btf_module_read(struct file *file, struct kobject *kobj,
6023 struct bin_attribute *bin_attr,
6024 char *buf, loff_t off, size_t len)
6026 const struct btf *btf = bin_attr->private;
6028 memcpy(buf, btf->data + off, len);
6032 static int btf_module_notify(struct notifier_block *nb, unsigned long op,
6035 struct btf_module *btf_mod, *tmp;
6036 struct module *mod = module;
6040 if (mod->btf_data_size == 0 ||
6041 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
6045 case MODULE_STATE_COMING:
6046 btf_mod = kzalloc(sizeof(*btf_mod), GFP_KERNEL);
6051 btf = btf_parse_module(mod->name, mod->btf_data, mod->btf_data_size);
6053 pr_warn("failed to validate module [%s] BTF: %ld\n",
6054 mod->name, PTR_ERR(btf));
6059 err = btf_alloc_id(btf);
6066 mutex_lock(&btf_module_mutex);
6067 btf_mod->module = module;
6069 list_add(&btf_mod->list, &btf_modules);
6070 mutex_unlock(&btf_module_mutex);
6072 if (IS_ENABLED(CONFIG_SYSFS)) {
6073 struct bin_attribute *attr;
6075 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
6079 sysfs_bin_attr_init(attr);
6080 attr->attr.name = btf->name;
6081 attr->attr.mode = 0444;
6082 attr->size = btf->data_size;
6083 attr->private = btf;
6084 attr->read = btf_module_read;
6086 err = sysfs_create_bin_file(btf_kobj, attr);
6088 pr_warn("failed to register module [%s] BTF in sysfs: %d\n",
6095 btf_mod->sysfs_attr = attr;
6099 case MODULE_STATE_GOING:
6100 mutex_lock(&btf_module_mutex);
6101 list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) {
6102 if (btf_mod->module != module)
6105 list_del(&btf_mod->list);
6106 if (btf_mod->sysfs_attr)
6107 sysfs_remove_bin_file(btf_kobj, btf_mod->sysfs_attr);
6108 btf_put(btf_mod->btf);
6109 kfree(btf_mod->sysfs_attr);
6113 mutex_unlock(&btf_module_mutex);
6117 return notifier_from_errno(err);
6120 static struct notifier_block btf_module_nb = {
6121 .notifier_call = btf_module_notify,
6124 static int __init btf_module_init(void)
6126 register_module_notifier(&btf_module_nb);
6130 fs_initcall(btf_module_init);
6131 #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */
6133 struct module *btf_try_get_module(const struct btf *btf)
6135 struct module *res = NULL;
6136 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
6137 struct btf_module *btf_mod, *tmp;
6139 mutex_lock(&btf_module_mutex);
6140 list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) {
6141 if (btf_mod->btf != btf)
6144 if (try_module_get(btf_mod->module))
6145 res = btf_mod->module;
6149 mutex_unlock(&btf_module_mutex);
6155 BPF_CALL_4(bpf_btf_find_by_name_kind, char *, name, int, name_sz, u32, kind, int, flags)
6163 if (name_sz <= 1 || name[name_sz - 1])
6166 btf = bpf_get_btf_vmlinux();
6168 return PTR_ERR(btf);
6170 ret = btf_find_by_name_kind(btf, name, kind);
6171 /* ret is never zero, since btf_find_by_name_kind returns
6172 * positive btf_id or negative error.
6175 struct btf *mod_btf;
6178 /* If name is not found in vmlinux's BTF then search in module's BTFs */
6179 spin_lock_bh(&btf_idr_lock);
6180 idr_for_each_entry(&btf_idr, mod_btf, id) {
6181 if (!btf_is_module(mod_btf))
6183 /* linear search could be slow hence unlock/lock
6184 * the IDR to avoiding holding it for too long
6187 spin_unlock_bh(&btf_idr_lock);
6188 ret = btf_find_by_name_kind(mod_btf, name, kind);
6192 btf_obj_fd = __btf_new_fd(mod_btf);
6193 if (btf_obj_fd < 0) {
6197 return ret | (((u64)btf_obj_fd) << 32);
6199 spin_lock_bh(&btf_idr_lock);
6202 spin_unlock_bh(&btf_idr_lock);
6207 const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = {
6208 .func = bpf_btf_find_by_name_kind,
6210 .ret_type = RET_INTEGER,
6211 .arg1_type = ARG_PTR_TO_MEM,
6212 .arg2_type = ARG_CONST_SIZE,
6213 .arg3_type = ARG_ANYTHING,
6214 .arg4_type = ARG_ANYTHING,