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1/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
2/* Copyright (c) 2018 Facebook */
3
4#ifndef __LIBBPF_BTF_H
5#define __LIBBPF_BTF_H
6
7#include <stdarg.h>
8#include <linux/btf.h>
9#include <linux/types.h>
10
11#include "libbpf_common.h"
12
13#ifdef __cplusplus
14extern "C" {
15#endif
16
17#define BTF_ELF_SEC ".BTF"
18#define BTF_EXT_ELF_SEC ".BTF.ext"
19#define MAPS_ELF_SEC ".maps"
20
21struct btf;
22struct btf_ext;
23struct btf_type;
24
25struct bpf_object;
26
27/*
28 * The .BTF.ext ELF section layout defined as
29 * struct btf_ext_header
30 * func_info subsection
31 *
32 * The func_info subsection layout:
33 * record size for struct bpf_func_info in the func_info subsection
34 * struct btf_sec_func_info for section #1
35 * a list of bpf_func_info records for section #1
36 * where struct bpf_func_info mimics one in include/uapi/linux/bpf.h
37 * but may not be identical
38 * struct btf_sec_func_info for section #2
39 * a list of bpf_func_info records for section #2
40 * ......
41 *
42 * Note that the bpf_func_info record size in .BTF.ext may not
43 * be the same as the one defined in include/uapi/linux/bpf.h.
44 * The loader should ensure that record_size meets minimum
45 * requirement and pass the record as is to the kernel. The
46 * kernel will handle the func_info properly based on its contents.
47 */
48struct btf_ext_header {
49 __u16 magic;
50 __u8 version;
51 __u8 flags;
52 __u32 hdr_len;
53
54 /* All offsets are in bytes relative to the end of this header */
55 __u32 func_info_off;
56 __u32 func_info_len;
57 __u32 line_info_off;
58 __u32 line_info_len;
59
60 /* optional part of .BTF.ext header */
61 __u32 field_reloc_off;
62 __u32 field_reloc_len;
63};
64
65LIBBPF_API void btf__free(struct btf *btf);
66LIBBPF_API struct btf *btf__new(const void *data, __u32 size);
67LIBBPF_API struct btf *btf__parse(const char *path, struct btf_ext **btf_ext);
68LIBBPF_API struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext);
69LIBBPF_API struct btf *btf__parse_raw(const char *path);
70LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf);
71LIBBPF_API int btf__load(struct btf *btf);
72LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
73 const char *type_name);
74LIBBPF_API __s32 btf__find_by_name_kind(const struct btf *btf,
75 const char *type_name, __u32 kind);
76LIBBPF_API __u32 btf__get_nr_types(const struct btf *btf);
77LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf,
78 __u32 id);
79LIBBPF_API size_t btf__pointer_size(const struct btf *btf);
80LIBBPF_API int btf__set_pointer_size(struct btf *btf, size_t ptr_sz);
81LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id);
82LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id);
83LIBBPF_API int btf__align_of(const struct btf *btf, __u32 id);
84LIBBPF_API int btf__fd(const struct btf *btf);
85LIBBPF_API void btf__set_fd(struct btf *btf, int fd);
86LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size);
87LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
88LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
89LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,
90 __u32 expected_key_size,
91 __u32 expected_value_size,
92 __u32 *key_type_id, __u32 *value_type_id);
93
94LIBBPF_API struct btf_ext *btf_ext__new(__u8 *data, __u32 size);
95LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext);
96LIBBPF_API const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext,
97 __u32 *size);
98LIBBPF_API int btf_ext__reloc_func_info(const struct btf *btf,
99 const struct btf_ext *btf_ext,
100 const char *sec_name, __u32 insns_cnt,
101 void **func_info, __u32 *cnt);
102LIBBPF_API int btf_ext__reloc_line_info(const struct btf *btf,
103 const struct btf_ext *btf_ext,
104 const char *sec_name, __u32 insns_cnt,
105 void **line_info, __u32 *cnt);
106LIBBPF_API __u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext);
107LIBBPF_API __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext);
108
109LIBBPF_API struct btf *libbpf_find_kernel_btf(void);
110
111struct btf_dedup_opts {
112 unsigned int dedup_table_size;
113 bool dont_resolve_fwds;
114};
115
116LIBBPF_API int btf__dedup(struct btf *btf, struct btf_ext *btf_ext,
117 const struct btf_dedup_opts *opts);
118
119struct btf_dump;
120
121struct btf_dump_opts {
122 void *ctx;
123};
124
125typedef void (*btf_dump_printf_fn_t)(void *ctx, const char *fmt, va_list args);
126
127LIBBPF_API struct btf_dump *btf_dump__new(const struct btf *btf,
128 const struct btf_ext *btf_ext,
129 const struct btf_dump_opts *opts,
130 btf_dump_printf_fn_t printf_fn);
131LIBBPF_API void btf_dump__free(struct btf_dump *d);
132
133LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id);
134
135struct btf_dump_emit_type_decl_opts {
136 /* size of this struct, for forward/backward compatiblity */
137 size_t sz;
138 /* optional field name for type declaration, e.g.:
139 * - struct my_struct <FNAME>
140 * - void (*<FNAME>)(int)
141 * - char (*<FNAME>)[123]
142 */
143 const char *field_name;
144 /* extra indentation level (in number of tabs) to emit for multi-line
145 * type declarations (e.g., anonymous struct); applies for lines
146 * starting from the second one (first line is assumed to have
147 * necessary indentation already
148 */
149 int indent_level;
150 /* strip all the const/volatile/restrict mods */
151 bool strip_mods;
152};
153#define btf_dump_emit_type_decl_opts__last_field strip_mods
154
155LIBBPF_API int
156btf_dump__emit_type_decl(struct btf_dump *d, __u32 id,
157 const struct btf_dump_emit_type_decl_opts *opts);
158
159/*
160 * A set of helpers for easier BTF types handling
161 */
162static inline __u16 btf_kind(const struct btf_type *t)
163{
164 return BTF_INFO_KIND(t->info);
165}
166
167static inline __u16 btf_vlen(const struct btf_type *t)
168{
169 return BTF_INFO_VLEN(t->info);
170}
171
172static inline bool btf_kflag(const struct btf_type *t)
173{
174 return BTF_INFO_KFLAG(t->info);
175}
176
177static inline bool btf_is_void(const struct btf_type *t)
178{
179 return btf_kind(t) == BTF_KIND_UNKN;
180}
181
182static inline bool btf_is_int(const struct btf_type *t)
183{
184 return btf_kind(t) == BTF_KIND_INT;
185}
186
187static inline bool btf_is_ptr(const struct btf_type *t)
188{
189 return btf_kind(t) == BTF_KIND_PTR;
190}
191
192static inline bool btf_is_array(const struct btf_type *t)
193{
194 return btf_kind(t) == BTF_KIND_ARRAY;
195}
196
197static inline bool btf_is_struct(const struct btf_type *t)
198{
199 return btf_kind(t) == BTF_KIND_STRUCT;
200}
201
202static inline bool btf_is_union(const struct btf_type *t)
203{
204 return btf_kind(t) == BTF_KIND_UNION;
205}
206
207static inline bool btf_is_composite(const struct btf_type *t)
208{
209 __u16 kind = btf_kind(t);
210
211 return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
212}
213
214static inline bool btf_is_enum(const struct btf_type *t)
215{
216 return btf_kind(t) == BTF_KIND_ENUM;
217}
218
219static inline bool btf_is_fwd(const struct btf_type *t)
220{
221 return btf_kind(t) == BTF_KIND_FWD;
222}
223
224static inline bool btf_is_typedef(const struct btf_type *t)
225{
226 return btf_kind(t) == BTF_KIND_TYPEDEF;
227}
228
229static inline bool btf_is_volatile(const struct btf_type *t)
230{
231 return btf_kind(t) == BTF_KIND_VOLATILE;
232}
233
234static inline bool btf_is_const(const struct btf_type *t)
235{
236 return btf_kind(t) == BTF_KIND_CONST;
237}
238
239static inline bool btf_is_restrict(const struct btf_type *t)
240{
241 return btf_kind(t) == BTF_KIND_RESTRICT;
242}
243
244static inline bool btf_is_mod(const struct btf_type *t)
245{
246 __u16 kind = btf_kind(t);
247
248 return kind == BTF_KIND_VOLATILE ||
249 kind == BTF_KIND_CONST ||
250 kind == BTF_KIND_RESTRICT;
251}
252
253static inline bool btf_is_func(const struct btf_type *t)
254{
255 return btf_kind(t) == BTF_KIND_FUNC;
256}
257
258static inline bool btf_is_func_proto(const struct btf_type *t)
259{
260 return btf_kind(t) == BTF_KIND_FUNC_PROTO;
261}
262
263static inline bool btf_is_var(const struct btf_type *t)
264{
265 return btf_kind(t) == BTF_KIND_VAR;
266}
267
268static inline bool btf_is_datasec(const struct btf_type *t)
269{
270 return btf_kind(t) == BTF_KIND_DATASEC;
271}
272
273static inline __u8 btf_int_encoding(const struct btf_type *t)
274{
275 return BTF_INT_ENCODING(*(__u32 *)(t + 1));
276}
277
278static inline __u8 btf_int_offset(const struct btf_type *t)
279{
280 return BTF_INT_OFFSET(*(__u32 *)(t + 1));
281}
282
283static inline __u8 btf_int_bits(const struct btf_type *t)
284{
285 return BTF_INT_BITS(*(__u32 *)(t + 1));
286}
287
288static inline struct btf_array *btf_array(const struct btf_type *t)
289{
290 return (struct btf_array *)(t + 1);
291}
292
293static inline struct btf_enum *btf_enum(const struct btf_type *t)
294{
295 return (struct btf_enum *)(t + 1);
296}
297
298static inline struct btf_member *btf_members(const struct btf_type *t)
299{
300 return (struct btf_member *)(t + 1);
301}
302
303/* Get bit offset of a member with specified index. */
304static inline __u32 btf_member_bit_offset(const struct btf_type *t,
305 __u32 member_idx)
306{
307 const struct btf_member *m = btf_members(t) + member_idx;
308 bool kflag = btf_kflag(t);
309
310 return kflag ? BTF_MEMBER_BIT_OFFSET(m->offset) : m->offset;
311}
312/*
313 * Get bitfield size of a member, assuming t is BTF_KIND_STRUCT or
314 * BTF_KIND_UNION. If member is not a bitfield, zero is returned.
315 */
316static inline __u32 btf_member_bitfield_size(const struct btf_type *t,
317 __u32 member_idx)
318{
319 const struct btf_member *m = btf_members(t) + member_idx;
320 bool kflag = btf_kflag(t);
321
322 return kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0;
323}
324
325static inline struct btf_param *btf_params(const struct btf_type *t)
326{
327 return (struct btf_param *)(t + 1);
328}
329
330static inline struct btf_var *btf_var(const struct btf_type *t)
331{
332 return (struct btf_var *)(t + 1);
333}
334
335static inline struct btf_var_secinfo *
336btf_var_secinfos(const struct btf_type *t)
337{
338 return (struct btf_var_secinfo *)(t + 1);
339}
340
341#ifdef __cplusplus
342} /* extern "C" */
343#endif
344
345#endif /* __LIBBPF_BTF_H */
1/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
2/* Copyright (c) 2018 Facebook */
3/*! \file */
4
5#ifndef __LIBBPF_BTF_H
6#define __LIBBPF_BTF_H
7
8#include <stdarg.h>
9#include <stdbool.h>
10#include <linux/btf.h>
11#include <linux/types.h>
12
13#include "libbpf_common.h"
14
15#ifdef __cplusplus
16extern "C" {
17#endif
18
19#define BTF_ELF_SEC ".BTF"
20#define BTF_EXT_ELF_SEC ".BTF.ext"
21#define BTF_BASE_ELF_SEC ".BTF.base"
22#define MAPS_ELF_SEC ".maps"
23
24struct btf;
25struct btf_ext;
26struct btf_type;
27
28struct bpf_object;
29
30enum btf_endianness {
31 BTF_LITTLE_ENDIAN = 0,
32 BTF_BIG_ENDIAN = 1,
33};
34
35/**
36 * @brief **btf__free()** frees all data of a BTF object
37 * @param btf BTF object to free
38 */
39LIBBPF_API void btf__free(struct btf *btf);
40
41/**
42 * @brief **btf__new()** creates a new instance of a BTF object from the raw
43 * bytes of an ELF's BTF section
44 * @param data raw bytes
45 * @param size number of bytes passed in `data`
46 * @return new BTF object instance which has to be eventually freed with
47 * **btf__free()**
48 *
49 * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract
50 * error code from such a pointer `libbpf_get_error()` should be used. If
51 * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is
52 * returned on error instead. In both cases thread-local `errno` variable is
53 * always set to error code as well.
54 */
55LIBBPF_API struct btf *btf__new(const void *data, __u32 size);
56
57/**
58 * @brief **btf__new_split()** create a new instance of a BTF object from the
59 * provided raw data bytes. It takes another BTF instance, **base_btf**, which
60 * serves as a base BTF, which is extended by types in a newly created BTF
61 * instance
62 * @param data raw bytes
63 * @param size length of raw bytes
64 * @param base_btf the base BTF object
65 * @return new BTF object instance which has to be eventually freed with
66 * **btf__free()**
67 *
68 * If *base_btf* is NULL, `btf__new_split()` is equivalent to `btf__new()` and
69 * creates non-split BTF.
70 *
71 * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract
72 * error code from such a pointer `libbpf_get_error()` should be used. If
73 * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is
74 * returned on error instead. In both cases thread-local `errno` variable is
75 * always set to error code as well.
76 */
77LIBBPF_API struct btf *btf__new_split(const void *data, __u32 size, struct btf *base_btf);
78
79/**
80 * @brief **btf__new_empty()** creates an empty BTF object. Use
81 * `btf__add_*()` to populate such BTF object.
82 * @return new BTF object instance which has to be eventually freed with
83 * **btf__free()**
84 *
85 * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract
86 * error code from such a pointer `libbpf_get_error()` should be used. If
87 * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is
88 * returned on error instead. In both cases thread-local `errno` variable is
89 * always set to error code as well.
90 */
91LIBBPF_API struct btf *btf__new_empty(void);
92
93/**
94 * @brief **btf__new_empty_split()** creates an unpopulated BTF object from an
95 * ELF BTF section except with a base BTF on top of which split BTF should be
96 * based
97 * @return new BTF object instance which has to be eventually freed with
98 * **btf__free()**
99 *
100 * If *base_btf* is NULL, `btf__new_empty_split()` is equivalent to
101 * `btf__new_empty()` and creates non-split BTF.
102 *
103 * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract
104 * error code from such a pointer `libbpf_get_error()` should be used. If
105 * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is
106 * returned on error instead. In both cases thread-local `errno` variable is
107 * always set to error code as well.
108 */
109LIBBPF_API struct btf *btf__new_empty_split(struct btf *base_btf);
110
111/**
112 * @brief **btf__distill_base()** creates new versions of the split BTF
113 * *src_btf* and its base BTF. The new base BTF will only contain the types
114 * needed to improve robustness of the split BTF to small changes in base BTF.
115 * When that split BTF is loaded against a (possibly changed) base, this
116 * distilled base BTF will help update references to that (possibly changed)
117 * base BTF.
118 *
119 * Both the new split and its associated new base BTF must be freed by
120 * the caller.
121 *
122 * If successful, 0 is returned and **new_base_btf** and **new_split_btf**
123 * will point at new base/split BTF. Both the new split and its associated
124 * new base BTF must be freed by the caller.
125 *
126 * A negative value is returned on error and the thread-local `errno` variable
127 * is set to the error code as well.
128 */
129LIBBPF_API int btf__distill_base(const struct btf *src_btf, struct btf **new_base_btf,
130 struct btf **new_split_btf);
131
132LIBBPF_API struct btf *btf__parse(const char *path, struct btf_ext **btf_ext);
133LIBBPF_API struct btf *btf__parse_split(const char *path, struct btf *base_btf);
134LIBBPF_API struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext);
135LIBBPF_API struct btf *btf__parse_elf_split(const char *path, struct btf *base_btf);
136LIBBPF_API struct btf *btf__parse_raw(const char *path);
137LIBBPF_API struct btf *btf__parse_raw_split(const char *path, struct btf *base_btf);
138
139LIBBPF_API struct btf *btf__load_vmlinux_btf(void);
140LIBBPF_API struct btf *btf__load_module_btf(const char *module_name, struct btf *vmlinux_btf);
141
142LIBBPF_API struct btf *btf__load_from_kernel_by_id(__u32 id);
143LIBBPF_API struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *base_btf);
144
145LIBBPF_API int btf__load_into_kernel(struct btf *btf);
146LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
147 const char *type_name);
148LIBBPF_API __s32 btf__find_by_name_kind(const struct btf *btf,
149 const char *type_name, __u32 kind);
150LIBBPF_API __u32 btf__type_cnt(const struct btf *btf);
151LIBBPF_API const struct btf *btf__base_btf(const struct btf *btf);
152LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf,
153 __u32 id);
154LIBBPF_API size_t btf__pointer_size(const struct btf *btf);
155LIBBPF_API int btf__set_pointer_size(struct btf *btf, size_t ptr_sz);
156LIBBPF_API enum btf_endianness btf__endianness(const struct btf *btf);
157LIBBPF_API int btf__set_endianness(struct btf *btf, enum btf_endianness endian);
158LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id);
159LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id);
160LIBBPF_API int btf__align_of(const struct btf *btf, __u32 id);
161LIBBPF_API int btf__fd(const struct btf *btf);
162LIBBPF_API void btf__set_fd(struct btf *btf, int fd);
163LIBBPF_API const void *btf__raw_data(const struct btf *btf, __u32 *size);
164LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
165LIBBPF_API const char *btf__str_by_offset(const struct btf *btf, __u32 offset);
166
167LIBBPF_API struct btf_ext *btf_ext__new(const __u8 *data, __u32 size);
168LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext);
169LIBBPF_API const void *btf_ext__raw_data(const struct btf_ext *btf_ext, __u32 *size);
170LIBBPF_API enum btf_endianness btf_ext__endianness(const struct btf_ext *btf_ext);
171LIBBPF_API int btf_ext__set_endianness(struct btf_ext *btf_ext,
172 enum btf_endianness endian);
173
174LIBBPF_API int btf__find_str(struct btf *btf, const char *s);
175LIBBPF_API int btf__add_str(struct btf *btf, const char *s);
176LIBBPF_API int btf__add_type(struct btf *btf, const struct btf *src_btf,
177 const struct btf_type *src_type);
178/**
179 * @brief **btf__add_btf()** appends all the BTF types from *src_btf* into *btf*
180 * @param btf BTF object which all the BTF types and strings are added to
181 * @param src_btf BTF object which all BTF types and referenced strings are copied from
182 * @return BTF type ID of the first appended BTF type, or negative error code
183 *
184 * **btf__add_btf()** can be used to simply and efficiently append the entire
185 * contents of one BTF object to another one. All the BTF type data is copied
186 * over, all referenced type IDs are adjusted by adding a necessary ID offset.
187 * Only strings referenced from BTF types are copied over and deduplicated, so
188 * if there were some unused strings in *src_btf*, those won't be copied over,
189 * which is consistent with the general string deduplication semantics of BTF
190 * writing APIs.
191 *
192 * If any error is encountered during this process, the contents of *btf* is
193 * left intact, which means that **btf__add_btf()** follows the transactional
194 * semantics and the operation as a whole is all-or-nothing.
195 *
196 * *src_btf* has to be non-split BTF, as of now copying types from split BTF
197 * is not supported and will result in -ENOTSUP error code returned.
198 */
199LIBBPF_API int btf__add_btf(struct btf *btf, const struct btf *src_btf);
200
201LIBBPF_API int btf__add_int(struct btf *btf, const char *name, size_t byte_sz, int encoding);
202LIBBPF_API int btf__add_float(struct btf *btf, const char *name, size_t byte_sz);
203LIBBPF_API int btf__add_ptr(struct btf *btf, int ref_type_id);
204LIBBPF_API int btf__add_array(struct btf *btf,
205 int index_type_id, int elem_type_id, __u32 nr_elems);
206/* struct/union construction APIs */
207LIBBPF_API int btf__add_struct(struct btf *btf, const char *name, __u32 sz);
208LIBBPF_API int btf__add_union(struct btf *btf, const char *name, __u32 sz);
209LIBBPF_API int btf__add_field(struct btf *btf, const char *name, int field_type_id,
210 __u32 bit_offset, __u32 bit_size);
211
212/* enum construction APIs */
213LIBBPF_API int btf__add_enum(struct btf *btf, const char *name, __u32 bytes_sz);
214LIBBPF_API int btf__add_enum_value(struct btf *btf, const char *name, __s64 value);
215LIBBPF_API int btf__add_enum64(struct btf *btf, const char *name, __u32 bytes_sz, bool is_signed);
216LIBBPF_API int btf__add_enum64_value(struct btf *btf, const char *name, __u64 value);
217
218enum btf_fwd_kind {
219 BTF_FWD_STRUCT = 0,
220 BTF_FWD_UNION = 1,
221 BTF_FWD_ENUM = 2,
222};
223
224LIBBPF_API int btf__add_fwd(struct btf *btf, const char *name, enum btf_fwd_kind fwd_kind);
225LIBBPF_API int btf__add_typedef(struct btf *btf, const char *name, int ref_type_id);
226LIBBPF_API int btf__add_volatile(struct btf *btf, int ref_type_id);
227LIBBPF_API int btf__add_const(struct btf *btf, int ref_type_id);
228LIBBPF_API int btf__add_restrict(struct btf *btf, int ref_type_id);
229LIBBPF_API int btf__add_type_tag(struct btf *btf, const char *value, int ref_type_id);
230
231/* func and func_proto construction APIs */
232LIBBPF_API int btf__add_func(struct btf *btf, const char *name,
233 enum btf_func_linkage linkage, int proto_type_id);
234LIBBPF_API int btf__add_func_proto(struct btf *btf, int ret_type_id);
235LIBBPF_API int btf__add_func_param(struct btf *btf, const char *name, int type_id);
236
237/* var & datasec construction APIs */
238LIBBPF_API int btf__add_var(struct btf *btf, const char *name, int linkage, int type_id);
239LIBBPF_API int btf__add_datasec(struct btf *btf, const char *name, __u32 byte_sz);
240LIBBPF_API int btf__add_datasec_var_info(struct btf *btf, int var_type_id,
241 __u32 offset, __u32 byte_sz);
242
243/* tag construction API */
244LIBBPF_API int btf__add_decl_tag(struct btf *btf, const char *value, int ref_type_id,
245 int component_idx);
246
247struct btf_dedup_opts {
248 size_t sz;
249 /* optional .BTF.ext info to dedup along the main BTF info */
250 struct btf_ext *btf_ext;
251 /* force hash collisions (used for testing) */
252 bool force_collisions;
253 size_t :0;
254};
255#define btf_dedup_opts__last_field force_collisions
256
257LIBBPF_API int btf__dedup(struct btf *btf, const struct btf_dedup_opts *opts);
258
259/**
260 * @brief **btf__relocate()** will check the split BTF *btf* for references
261 * to base BTF kinds, and verify those references are compatible with
262 * *base_btf*; if they are, *btf* is adjusted such that is re-parented to
263 * *base_btf* and type ids and strings are adjusted to accommodate this.
264 *
265 * If successful, 0 is returned and **btf** now has **base_btf** as its
266 * base.
267 *
268 * A negative value is returned on error and the thread-local `errno` variable
269 * is set to the error code as well.
270 */
271LIBBPF_API int btf__relocate(struct btf *btf, const struct btf *base_btf);
272
273struct btf_dump;
274
275struct btf_dump_opts {
276 size_t sz;
277};
278#define btf_dump_opts__last_field sz
279
280typedef void (*btf_dump_printf_fn_t)(void *ctx, const char *fmt, va_list args);
281
282LIBBPF_API struct btf_dump *btf_dump__new(const struct btf *btf,
283 btf_dump_printf_fn_t printf_fn,
284 void *ctx,
285 const struct btf_dump_opts *opts);
286
287LIBBPF_API void btf_dump__free(struct btf_dump *d);
288
289LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id);
290
291struct btf_dump_emit_type_decl_opts {
292 /* size of this struct, for forward/backward compatibility */
293 size_t sz;
294 /* optional field name for type declaration, e.g.:
295 * - struct my_struct <FNAME>
296 * - void (*<FNAME>)(int)
297 * - char (*<FNAME>)[123]
298 */
299 const char *field_name;
300 /* extra indentation level (in number of tabs) to emit for multi-line
301 * type declarations (e.g., anonymous struct); applies for lines
302 * starting from the second one (first line is assumed to have
303 * necessary indentation already
304 */
305 int indent_level;
306 /* strip all the const/volatile/restrict mods */
307 bool strip_mods;
308 size_t :0;
309};
310#define btf_dump_emit_type_decl_opts__last_field strip_mods
311
312LIBBPF_API int
313btf_dump__emit_type_decl(struct btf_dump *d, __u32 id,
314 const struct btf_dump_emit_type_decl_opts *opts);
315
316
317struct btf_dump_type_data_opts {
318 /* size of this struct, for forward/backward compatibility */
319 size_t sz;
320 const char *indent_str;
321 int indent_level;
322 /* below match "show" flags for bpf_show_snprintf() */
323 bool compact; /* no newlines/indentation */
324 bool skip_names; /* skip member/type names */
325 bool emit_zeroes; /* show 0-valued fields */
326 size_t :0;
327};
328#define btf_dump_type_data_opts__last_field emit_zeroes
329
330LIBBPF_API int
331btf_dump__dump_type_data(struct btf_dump *d, __u32 id,
332 const void *data, size_t data_sz,
333 const struct btf_dump_type_data_opts *opts);
334
335/*
336 * A set of helpers for easier BTF types handling.
337 *
338 * The inline functions below rely on constants from the kernel headers which
339 * may not be available for applications including this header file. To avoid
340 * compilation errors, we define all the constants here that were added after
341 * the initial introduction of the BTF_KIND* constants.
342 */
343#ifndef BTF_KIND_FUNC
344#define BTF_KIND_FUNC 12 /* Function */
345#define BTF_KIND_FUNC_PROTO 13 /* Function Proto */
346#endif
347#ifndef BTF_KIND_VAR
348#define BTF_KIND_VAR 14 /* Variable */
349#define BTF_KIND_DATASEC 15 /* Section */
350#endif
351#ifndef BTF_KIND_FLOAT
352#define BTF_KIND_FLOAT 16 /* Floating point */
353#endif
354/* The kernel header switched to enums, so the following were never #defined */
355#define BTF_KIND_DECL_TAG 17 /* Decl Tag */
356#define BTF_KIND_TYPE_TAG 18 /* Type Tag */
357#define BTF_KIND_ENUM64 19 /* Enum for up-to 64bit values */
358
359static inline __u16 btf_kind(const struct btf_type *t)
360{
361 return BTF_INFO_KIND(t->info);
362}
363
364static inline __u16 btf_vlen(const struct btf_type *t)
365{
366 return BTF_INFO_VLEN(t->info);
367}
368
369static inline bool btf_kflag(const struct btf_type *t)
370{
371 return BTF_INFO_KFLAG(t->info);
372}
373
374static inline bool btf_is_void(const struct btf_type *t)
375{
376 return btf_kind(t) == BTF_KIND_UNKN;
377}
378
379static inline bool btf_is_int(const struct btf_type *t)
380{
381 return btf_kind(t) == BTF_KIND_INT;
382}
383
384static inline bool btf_is_ptr(const struct btf_type *t)
385{
386 return btf_kind(t) == BTF_KIND_PTR;
387}
388
389static inline bool btf_is_array(const struct btf_type *t)
390{
391 return btf_kind(t) == BTF_KIND_ARRAY;
392}
393
394static inline bool btf_is_struct(const struct btf_type *t)
395{
396 return btf_kind(t) == BTF_KIND_STRUCT;
397}
398
399static inline bool btf_is_union(const struct btf_type *t)
400{
401 return btf_kind(t) == BTF_KIND_UNION;
402}
403
404static inline bool btf_is_composite(const struct btf_type *t)
405{
406 __u16 kind = btf_kind(t);
407
408 return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
409}
410
411static inline bool btf_is_enum(const struct btf_type *t)
412{
413 return btf_kind(t) == BTF_KIND_ENUM;
414}
415
416static inline bool btf_is_enum64(const struct btf_type *t)
417{
418 return btf_kind(t) == BTF_KIND_ENUM64;
419}
420
421static inline bool btf_is_fwd(const struct btf_type *t)
422{
423 return btf_kind(t) == BTF_KIND_FWD;
424}
425
426static inline bool btf_is_typedef(const struct btf_type *t)
427{
428 return btf_kind(t) == BTF_KIND_TYPEDEF;
429}
430
431static inline bool btf_is_volatile(const struct btf_type *t)
432{
433 return btf_kind(t) == BTF_KIND_VOLATILE;
434}
435
436static inline bool btf_is_const(const struct btf_type *t)
437{
438 return btf_kind(t) == BTF_KIND_CONST;
439}
440
441static inline bool btf_is_restrict(const struct btf_type *t)
442{
443 return btf_kind(t) == BTF_KIND_RESTRICT;
444}
445
446static inline bool btf_is_mod(const struct btf_type *t)
447{
448 __u16 kind = btf_kind(t);
449
450 return kind == BTF_KIND_VOLATILE ||
451 kind == BTF_KIND_CONST ||
452 kind == BTF_KIND_RESTRICT ||
453 kind == BTF_KIND_TYPE_TAG;
454}
455
456static inline bool btf_is_func(const struct btf_type *t)
457{
458 return btf_kind(t) == BTF_KIND_FUNC;
459}
460
461static inline bool btf_is_func_proto(const struct btf_type *t)
462{
463 return btf_kind(t) == BTF_KIND_FUNC_PROTO;
464}
465
466static inline bool btf_is_var(const struct btf_type *t)
467{
468 return btf_kind(t) == BTF_KIND_VAR;
469}
470
471static inline bool btf_is_datasec(const struct btf_type *t)
472{
473 return btf_kind(t) == BTF_KIND_DATASEC;
474}
475
476static inline bool btf_is_float(const struct btf_type *t)
477{
478 return btf_kind(t) == BTF_KIND_FLOAT;
479}
480
481static inline bool btf_is_decl_tag(const struct btf_type *t)
482{
483 return btf_kind(t) == BTF_KIND_DECL_TAG;
484}
485
486static inline bool btf_is_type_tag(const struct btf_type *t)
487{
488 return btf_kind(t) == BTF_KIND_TYPE_TAG;
489}
490
491static inline bool btf_is_any_enum(const struct btf_type *t)
492{
493 return btf_is_enum(t) || btf_is_enum64(t);
494}
495
496static inline bool btf_kind_core_compat(const struct btf_type *t1,
497 const struct btf_type *t2)
498{
499 return btf_kind(t1) == btf_kind(t2) ||
500 (btf_is_any_enum(t1) && btf_is_any_enum(t2));
501}
502
503static inline __u8 btf_int_encoding(const struct btf_type *t)
504{
505 return BTF_INT_ENCODING(*(__u32 *)(t + 1));
506}
507
508static inline __u8 btf_int_offset(const struct btf_type *t)
509{
510 return BTF_INT_OFFSET(*(__u32 *)(t + 1));
511}
512
513static inline __u8 btf_int_bits(const struct btf_type *t)
514{
515 return BTF_INT_BITS(*(__u32 *)(t + 1));
516}
517
518static inline struct btf_array *btf_array(const struct btf_type *t)
519{
520 return (struct btf_array *)(t + 1);
521}
522
523static inline struct btf_enum *btf_enum(const struct btf_type *t)
524{
525 return (struct btf_enum *)(t + 1);
526}
527
528struct btf_enum64;
529
530static inline struct btf_enum64 *btf_enum64(const struct btf_type *t)
531{
532 return (struct btf_enum64 *)(t + 1);
533}
534
535static inline __u64 btf_enum64_value(const struct btf_enum64 *e)
536{
537 /* struct btf_enum64 is introduced in Linux 6.0, which is very
538 * bleeding-edge. Here we are avoiding relying on struct btf_enum64
539 * definition coming from kernel UAPI headers to support wider range
540 * of system-wide kernel headers.
541 *
542 * Given this header can be also included from C++ applications, that
543 * further restricts C tricks we can use (like using compatible
544 * anonymous struct). So just treat struct btf_enum64 as
545 * a three-element array of u32 and access second (lo32) and third
546 * (hi32) elements directly.
547 *
548 * For reference, here is a struct btf_enum64 definition:
549 *
550 * const struct btf_enum64 {
551 * __u32 name_off;
552 * __u32 val_lo32;
553 * __u32 val_hi32;
554 * };
555 */
556 const __u32 *e64 = (const __u32 *)e;
557
558 return ((__u64)e64[2] << 32) | e64[1];
559}
560
561static inline struct btf_member *btf_members(const struct btf_type *t)
562{
563 return (struct btf_member *)(t + 1);
564}
565
566/* Get bit offset of a member with specified index. */
567static inline __u32 btf_member_bit_offset(const struct btf_type *t,
568 __u32 member_idx)
569{
570 const struct btf_member *m = btf_members(t) + member_idx;
571 bool kflag = btf_kflag(t);
572
573 return kflag ? BTF_MEMBER_BIT_OFFSET(m->offset) : m->offset;
574}
575/*
576 * Get bitfield size of a member, assuming t is BTF_KIND_STRUCT or
577 * BTF_KIND_UNION. If member is not a bitfield, zero is returned.
578 */
579static inline __u32 btf_member_bitfield_size(const struct btf_type *t,
580 __u32 member_idx)
581{
582 const struct btf_member *m = btf_members(t) + member_idx;
583 bool kflag = btf_kflag(t);
584
585 return kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0;
586}
587
588static inline struct btf_param *btf_params(const struct btf_type *t)
589{
590 return (struct btf_param *)(t + 1);
591}
592
593static inline struct btf_var *btf_var(const struct btf_type *t)
594{
595 return (struct btf_var *)(t + 1);
596}
597
598static inline struct btf_var_secinfo *
599btf_var_secinfos(const struct btf_type *t)
600{
601 return (struct btf_var_secinfo *)(t + 1);
602}
603
604struct btf_decl_tag;
605static inline struct btf_decl_tag *btf_decl_tag(const struct btf_type *t)
606{
607 return (struct btf_decl_tag *)(t + 1);
608}
609
610#ifdef __cplusplus
611} /* extern "C" */
612#endif
613
614#endif /* __LIBBPF_BTF_H */