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
,
6217 BTF_ID_LIST_GLOBAL_SINGLE(btf_task_struct_ids
, struct, task_struct
)