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 <linux/types.h> 8 9 #ifdef __cplusplus 10 extern "C" { 11 #endif 12 13 #ifndef LIBBPF_API 14 #define LIBBPF_API __attribute__((visibility("default"))) 15 #endif 16 17 #define BTF_ELF_SEC ".BTF" 18 #define BTF_EXT_ELF_SEC ".BTF.ext" 19 20 struct btf; 21 struct btf_ext; 22 struct btf_type; 23 24 /* 25 * The .BTF.ext ELF section layout defined as 26 * struct btf_ext_header 27 * func_info subsection 28 * 29 * The func_info subsection layout: 30 * record size for struct bpf_func_info in the func_info subsection 31 * struct btf_sec_func_info for section #1 32 * a list of bpf_func_info records for section #1 33 * where struct bpf_func_info mimics one in include/uapi/linux/bpf.h 34 * but may not be identical 35 * struct btf_sec_func_info for section #2 36 * a list of bpf_func_info records for section #2 37 * ...... 38 * 39 * Note that the bpf_func_info record size in .BTF.ext may not 40 * be the same as the one defined in include/uapi/linux/bpf.h. 41 * The loader should ensure that record_size meets minimum 42 * requirement and pass the record as is to the kernel. The 43 * kernel will handle the func_info properly based on its contents. 44 */ 45 struct btf_ext_header { 46 __u16 magic; 47 __u8 version; 48 __u8 flags; 49 __u32 hdr_len; 50 51 /* All offsets are in bytes relative to the end of this header */ 52 __u32 func_info_off; 53 __u32 func_info_len; 54 }; 55 56 struct btf_sec_func_info { 57 __u32 sec_name_off; 58 __u32 num_func_info; 59 /* Followed by num_func_info number of bpf func_info records */ 60 __u8 data[0]; 61 }; 62 63 typedef int (*btf_print_fn_t)(const char *, ...) 64 __attribute__((format(printf, 1, 2))); 65 66 LIBBPF_API void btf__free(struct btf *btf); 67 LIBBPF_API struct btf *btf__new(__u8 *data, __u32 size, btf_print_fn_t err_log); 68 LIBBPF_API __s32 btf__find_by_name(const struct btf *btf, 69 const char *type_name); 70 LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf, 71 __u32 id); 72 LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id); 73 LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id); 74 LIBBPF_API int btf__fd(const struct btf *btf); 75 LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset); 76 LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf); 77 78 struct btf_ext *btf_ext__new(__u8 *data, __u32 size, btf_print_fn_t err_log); 79 void btf_ext__free(struct btf_ext *btf_ext); 80 int btf_ext__reloc_init(struct btf *btf, struct btf_ext *btf_ext, 81 const char *sec_name, void **func_info, 82 __u32 *func_info_rec_size, __u32 *func_info_len); 83 int btf_ext__reloc(struct btf *btf, struct btf_ext *btf_ext, 84 const char *sec_name, __u32 insns_cnt, void **func_info, 85 __u32 *func_info_len); 86 87 #ifdef __cplusplus 88 } /* extern "C" */ 89 #endif 90 91 #endif /* __LIBBPF_BTF_H */ 92