1d7c4b398SAndrii Nakryiko /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ 2d7c4b398SAndrii Nakryiko 3d7c4b398SAndrii Nakryiko /* 4d7c4b398SAndrii Nakryiko * Internal libbpf helpers. 5d7c4b398SAndrii Nakryiko * 6d7c4b398SAndrii Nakryiko * Copyright (c) 2019 Facebook 7d7c4b398SAndrii Nakryiko */ 8d7c4b398SAndrii Nakryiko 9d7c4b398SAndrii Nakryiko #ifndef __LIBBPF_LIBBPF_INTERNAL_H 10d7c4b398SAndrii Nakryiko #define __LIBBPF_LIBBPF_INTERNAL_H 11d7c4b398SAndrii Nakryiko 12029258d7SAndrii Nakryiko #include <stdlib.h> 13dda1ec9fSAndrii Nakryiko #include <limits.h> 1485367030SAndrii Nakryiko 1585367030SAndrii Nakryiko /* make sure libbpf doesn't use kernel-only integer typedefs */ 1685367030SAndrii Nakryiko #pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 1785367030SAndrii Nakryiko 1885367030SAndrii Nakryiko /* prevent accidental re-addition of reallocarray() */ 1985367030SAndrii Nakryiko #pragma GCC poison reallocarray 2085367030SAndrii Nakryiko 211d7a08b3SAndrii Nakryiko #include "libbpf.h" 22aea28a60SAndrii Nakryiko #include "btf.h" 231d7a08b3SAndrii Nakryiko 24faf6ed32SAndrii Nakryiko #ifndef EM_BPF 25faf6ed32SAndrii Nakryiko #define EM_BPF 247 26faf6ed32SAndrii Nakryiko #endif 27faf6ed32SAndrii Nakryiko 28faf6ed32SAndrii Nakryiko #ifndef R_BPF_64_64 29faf6ed32SAndrii Nakryiko #define R_BPF_64_64 1 30faf6ed32SAndrii Nakryiko #endif 31faf6ed32SAndrii Nakryiko #ifndef R_BPF_64_32 32faf6ed32SAndrii Nakryiko #define R_BPF_64_32 10 33faf6ed32SAndrii Nakryiko #endif 34faf6ed32SAndrii Nakryiko 35faf6ed32SAndrii Nakryiko #ifndef SHT_LLVM_ADDRSIG 36faf6ed32SAndrii Nakryiko #define SHT_LLVM_ADDRSIG 0x6FFF4C03 37faf6ed32SAndrii Nakryiko #endif 38faf6ed32SAndrii Nakryiko 39faf6ed32SAndrii Nakryiko /* if libelf is old and doesn't support mmap(), fall back to read() */ 40faf6ed32SAndrii Nakryiko #ifndef ELF_C_READ_MMAP 41faf6ed32SAndrii Nakryiko #define ELF_C_READ_MMAP ELF_C_READ 42faf6ed32SAndrii Nakryiko #endif 43faf6ed32SAndrii Nakryiko 44d7c4b398SAndrii Nakryiko #define BTF_INFO_ENC(kind, kind_flag, vlen) \ 45d7c4b398SAndrii Nakryiko ((!!(kind_flag) << 31) | ((kind) << 24) | ((vlen) & BTF_MAX_VLEN)) 46d7c4b398SAndrii Nakryiko #define BTF_TYPE_ENC(name, info, size_or_type) (name), (info), (size_or_type) 47d7c4b398SAndrii Nakryiko #define BTF_INT_ENC(encoding, bits_offset, nr_bits) \ 48d7c4b398SAndrii Nakryiko ((encoding) << 24 | (bits_offset) << 16 | (nr_bits)) 49d7c4b398SAndrii Nakryiko #define BTF_TYPE_INT_ENC(name, encoding, bits_offset, bits, sz) \ 50d7c4b398SAndrii Nakryiko BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_INT, 0, 0), sz), \ 51d7c4b398SAndrii Nakryiko BTF_INT_ENC(encoding, bits_offset, bits) 52d7c4b398SAndrii Nakryiko #define BTF_MEMBER_ENC(name, type, bits_offset) (name), (type), (bits_offset) 53d7c4b398SAndrii Nakryiko #define BTF_PARAM_ENC(name, type) (name), (type) 54d7c4b398SAndrii Nakryiko #define BTF_VAR_SECINFO_ENC(type, offset, size) (type), (offset), (size) 5522541a9eSIlya Leoshkevich #define BTF_TYPE_FLOAT_ENC(name, sz) \ 5622541a9eSIlya Leoshkevich BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_FLOAT, 0, 0), sz) 57d7c4b398SAndrii Nakryiko 58029258d7SAndrii Nakryiko #ifndef likely 59029258d7SAndrii Nakryiko #define likely(x) __builtin_expect(!!(x), 1) 60029258d7SAndrii Nakryiko #endif 61029258d7SAndrii Nakryiko #ifndef unlikely 62029258d7SAndrii Nakryiko #define unlikely(x) __builtin_expect(!!(x), 0) 63029258d7SAndrii Nakryiko #endif 64d7fe74f9SAndrii Nakryiko #ifndef min 65d7fe74f9SAndrii Nakryiko # define min(x, y) ((x) < (y) ? (x) : (y)) 66d7fe74f9SAndrii Nakryiko #endif 67d7fe74f9SAndrii Nakryiko #ifndef max 68d7fe74f9SAndrii Nakryiko # define max(x, y) ((x) < (y) ? (y) : (x)) 69d7fe74f9SAndrii Nakryiko #endif 704cedc0daSAndrii Nakryiko #ifndef offsetofend 714cedc0daSAndrii Nakryiko # define offsetofend(TYPE, FIELD) \ 724cedc0daSAndrii Nakryiko (offsetof(TYPE, FIELD) + sizeof(((TYPE *)0)->FIELD)) 734cedc0daSAndrii Nakryiko #endif 74d7fe74f9SAndrii Nakryiko 751bd63524SYonghong Song /* Symbol versioning is different between static and shared library. 761bd63524SYonghong Song * Properly versioned symbols are needed for shared library, but 771bd63524SYonghong Song * only the symbol of the new version is needed for static library. 781bd63524SYonghong Song */ 791bd63524SYonghong Song #ifdef SHARED 801bd63524SYonghong Song # define COMPAT_VERSION(internal_name, api_name, version) \ 811bd63524SYonghong Song asm(".symver " #internal_name "," #api_name "@" #version); 821bd63524SYonghong Song # define DEFAULT_VERSION(internal_name, api_name, version) \ 831bd63524SYonghong Song asm(".symver " #internal_name "," #api_name "@@" #version); 841bd63524SYonghong Song #else 851bd63524SYonghong Song # define COMPAT_VERSION(internal_name, api_name, version) 861bd63524SYonghong Song # define DEFAULT_VERSION(internal_name, api_name, version) \ 871bd63524SYonghong Song extern typeof(internal_name) api_name \ 881bd63524SYonghong Song __attribute__((alias(#internal_name))); 891bd63524SYonghong Song #endif 901bd63524SYonghong Song 91d72386feSAndrii Nakryiko extern void libbpf_print(enum libbpf_print_level level, 92d72386feSAndrii Nakryiko const char *format, ...) 93d72386feSAndrii Nakryiko __attribute__((format(printf, 2, 3))); 94d72386feSAndrii Nakryiko 95d72386feSAndrii Nakryiko #define __pr(level, fmt, ...) \ 96d72386feSAndrii Nakryiko do { \ 97d72386feSAndrii Nakryiko libbpf_print(level, "libbpf: " fmt, ##__VA_ARGS__); \ 98d72386feSAndrii Nakryiko } while (0) 99d72386feSAndrii Nakryiko 100be18010eSKefeng Wang #define pr_warn(fmt, ...) __pr(LIBBPF_WARN, fmt, ##__VA_ARGS__) 101d72386feSAndrii Nakryiko #define pr_info(fmt, ...) __pr(LIBBPF_INFO, fmt, ##__VA_ARGS__) 102d72386feSAndrii Nakryiko #define pr_debug(fmt, ...) __pr(LIBBPF_DEBUG, fmt, ##__VA_ARGS__) 103d72386feSAndrii Nakryiko 104dda1ec9fSAndrii Nakryiko #ifndef __has_builtin 105dda1ec9fSAndrii Nakryiko #define __has_builtin(x) 0 106dda1ec9fSAndrii Nakryiko #endif 107029258d7SAndrii Nakryiko /* 108029258d7SAndrii Nakryiko * Re-implement glibc's reallocarray() for libbpf internal-only use. 109029258d7SAndrii Nakryiko * reallocarray(), unfortunately, is not available in all versions of glibc, 110029258d7SAndrii Nakryiko * so requires extra feature detection and using reallocarray() stub from 111029258d7SAndrii Nakryiko * <tools/libc_compat.h> and COMPAT_NEED_REALLOCARRAY. All this complicates 112029258d7SAndrii Nakryiko * build of libbpf unnecessarily and is just a maintenance burden. Instead, 113029258d7SAndrii Nakryiko * it's trivial to implement libbpf-specific internal version and use it 114029258d7SAndrii Nakryiko * throughout libbpf. 115029258d7SAndrii Nakryiko */ 116029258d7SAndrii Nakryiko static inline void *libbpf_reallocarray(void *ptr, size_t nmemb, size_t size) 117029258d7SAndrii Nakryiko { 118029258d7SAndrii Nakryiko size_t total; 119029258d7SAndrii Nakryiko 120dda1ec9fSAndrii Nakryiko #if __has_builtin(__builtin_mul_overflow) 121029258d7SAndrii Nakryiko if (unlikely(__builtin_mul_overflow(nmemb, size, &total))) 122029258d7SAndrii Nakryiko return NULL; 123dda1ec9fSAndrii Nakryiko #else 124dda1ec9fSAndrii Nakryiko if (size == 0 || nmemb > ULONG_MAX / size) 125dda1ec9fSAndrii Nakryiko return NULL; 126dda1ec9fSAndrii Nakryiko total = nmemb * size; 127dda1ec9fSAndrii Nakryiko #endif 128029258d7SAndrii Nakryiko return realloc(ptr, total); 129029258d7SAndrii Nakryiko } 130029258d7SAndrii Nakryiko 131e14ef4bfSAndrii Nakryiko struct btf; 132e14ef4bfSAndrii Nakryiko struct btf_type; 133e14ef4bfSAndrii Nakryiko 134e14ef4bfSAndrii Nakryiko struct btf_type *btf_type_by_id(struct btf *btf, __u32 type_id); 13542869d28SAndrii Nakryiko const char *btf_kind_str(const struct btf_type *t); 13642869d28SAndrii Nakryiko const struct btf_type *skip_mods_and_typedefs(const struct btf *btf, __u32 id, __u32 *res_id); 13742869d28SAndrii Nakryiko 13842869d28SAndrii Nakryiko static inline enum btf_func_linkage btf_func_linkage(const struct btf_type *t) 13942869d28SAndrii Nakryiko { 14042869d28SAndrii Nakryiko return (enum btf_func_linkage)(int)btf_vlen(t); 14142869d28SAndrii Nakryiko } 142e14ef4bfSAndrii Nakryiko 143aea28a60SAndrii Nakryiko static inline __u32 btf_type_info(int kind, int vlen, int kflag) 144aea28a60SAndrii Nakryiko { 145aea28a60SAndrii Nakryiko return (kflag << 31) | (kind << 24) | vlen; 146aea28a60SAndrii Nakryiko } 147aea28a60SAndrii Nakryiko 148c7ef5ec9SAndrii Nakryiko enum map_def_parts { 149c7ef5ec9SAndrii Nakryiko MAP_DEF_MAP_TYPE = 0x001, 150c7ef5ec9SAndrii Nakryiko MAP_DEF_KEY_TYPE = 0x002, 151c7ef5ec9SAndrii Nakryiko MAP_DEF_KEY_SIZE = 0x004, 152c7ef5ec9SAndrii Nakryiko MAP_DEF_VALUE_TYPE = 0x008, 153c7ef5ec9SAndrii Nakryiko MAP_DEF_VALUE_SIZE = 0x010, 154c7ef5ec9SAndrii Nakryiko MAP_DEF_MAX_ENTRIES = 0x020, 155c7ef5ec9SAndrii Nakryiko MAP_DEF_MAP_FLAGS = 0x040, 156c7ef5ec9SAndrii Nakryiko MAP_DEF_NUMA_NODE = 0x080, 157c7ef5ec9SAndrii Nakryiko MAP_DEF_PINNING = 0x100, 158c7ef5ec9SAndrii Nakryiko MAP_DEF_INNER_MAP = 0x200, 159c7ef5ec9SAndrii Nakryiko 160c7ef5ec9SAndrii Nakryiko MAP_DEF_ALL = 0x3ff, /* combination of all above */ 161c7ef5ec9SAndrii Nakryiko }; 162c7ef5ec9SAndrii Nakryiko 163c7ef5ec9SAndrii Nakryiko struct btf_map_def { 164c7ef5ec9SAndrii Nakryiko enum map_def_parts parts; 165c7ef5ec9SAndrii Nakryiko __u32 map_type; 166c7ef5ec9SAndrii Nakryiko __u32 key_type_id; 167c7ef5ec9SAndrii Nakryiko __u32 key_size; 168c7ef5ec9SAndrii Nakryiko __u32 value_type_id; 169c7ef5ec9SAndrii Nakryiko __u32 value_size; 170c7ef5ec9SAndrii Nakryiko __u32 max_entries; 171c7ef5ec9SAndrii Nakryiko __u32 map_flags; 172c7ef5ec9SAndrii Nakryiko __u32 numa_node; 173c7ef5ec9SAndrii Nakryiko __u32 pinning; 174c7ef5ec9SAndrii Nakryiko }; 175c7ef5ec9SAndrii Nakryiko 176c7ef5ec9SAndrii Nakryiko int parse_btf_map_def(const char *map_name, struct btf *btf, 177c7ef5ec9SAndrii Nakryiko const struct btf_type *def_t, bool strict, 178c7ef5ec9SAndrii Nakryiko struct btf_map_def *map_def, struct btf_map_def *inner_def); 179c7ef5ec9SAndrii Nakryiko 1803b029e06SAndrii Nakryiko void *libbpf_add_mem(void **data, size_t *cap_cnt, size_t elem_sz, 181192f5a1fSAndrii Nakryiko size_t cur_cnt, size_t max_cnt, size_t add_cnt); 1823b029e06SAndrii Nakryiko int libbpf_ensure_mem(void **data, size_t *cap_cnt, size_t elem_sz, size_t need_cnt); 183192f5a1fSAndrii Nakryiko 1842ce8450eSAndrii Nakryiko static inline bool libbpf_validate_opts(const char *opts, 1852ce8450eSAndrii Nakryiko size_t opts_sz, size_t user_sz, 1862ce8450eSAndrii Nakryiko const char *type_name) 1872ce8450eSAndrii Nakryiko { 1882ce8450eSAndrii Nakryiko if (user_sz < sizeof(size_t)) { 189be18010eSKefeng Wang pr_warn("%s size (%zu) is too small\n", type_name, user_sz); 1902ce8450eSAndrii Nakryiko return false; 1912ce8450eSAndrii Nakryiko } 1922ce8450eSAndrii Nakryiko if (user_sz > opts_sz) { 1932ce8450eSAndrii Nakryiko size_t i; 1942ce8450eSAndrii Nakryiko 1952ce8450eSAndrii Nakryiko for (i = opts_sz; i < user_sz; i++) { 1962ce8450eSAndrii Nakryiko if (opts[i]) { 19712dd14b2SToke Høiland-Jørgensen pr_warn("%s has non-zero extra bytes\n", 1982ce8450eSAndrii Nakryiko type_name); 1992ce8450eSAndrii Nakryiko return false; 2002ce8450eSAndrii Nakryiko } 2012ce8450eSAndrii Nakryiko } 2022ce8450eSAndrii Nakryiko } 2032ce8450eSAndrii Nakryiko return true; 2042ce8450eSAndrii Nakryiko } 2052ce8450eSAndrii Nakryiko 2062ce8450eSAndrii Nakryiko #define OPTS_VALID(opts, type) \ 2072ce8450eSAndrii Nakryiko (!(opts) || libbpf_validate_opts((const char *)opts, \ 2082ce8450eSAndrii Nakryiko offsetofend(struct type, \ 2092ce8450eSAndrii Nakryiko type##__last_field), \ 2102ce8450eSAndrii Nakryiko (opts)->sz, #type)) 2112ce8450eSAndrii Nakryiko #define OPTS_HAS(opts, field) \ 2122ce8450eSAndrii Nakryiko ((opts) && opts->sz >= offsetofend(typeof(*(opts)), field)) 2132ce8450eSAndrii Nakryiko #define OPTS_GET(opts, field, fallback_value) \ 2142ce8450eSAndrii Nakryiko (OPTS_HAS(opts, field) ? (opts)->field : fallback_value) 21588f7fe72SSong Liu #define OPTS_SET(opts, field, value) \ 21688f7fe72SSong Liu do { \ 21788f7fe72SSong Liu if (OPTS_HAS(opts, field)) \ 21888f7fe72SSong Liu (opts)->field = value; \ 21988f7fe72SSong Liu } while (0) 2202ce8450eSAndrii Nakryiko 2216803ee25SAndrii Nakryiko int parse_cpu_mask_str(const char *s, bool **mask, int *mask_sz); 2226803ee25SAndrii Nakryiko int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz); 223cfd49210SMichal Rostecki int libbpf__load_raw_btf(const char *raw_types, size_t types_len, 224d7c4b398SAndrii Nakryiko const char *str_sec, size_t str_len); 225d7c4b398SAndrii Nakryiko 2266aef10a4SAndrii Nakryiko struct bpf_prog_load_params { 2276aef10a4SAndrii Nakryiko enum bpf_prog_type prog_type; 2286aef10a4SAndrii Nakryiko enum bpf_attach_type expected_attach_type; 2296aef10a4SAndrii Nakryiko const char *name; 2306aef10a4SAndrii Nakryiko const struct bpf_insn *insns; 2316aef10a4SAndrii Nakryiko size_t insn_cnt; 2326aef10a4SAndrii Nakryiko const char *license; 2336aef10a4SAndrii Nakryiko __u32 kern_version; 2346aef10a4SAndrii Nakryiko __u32 attach_prog_fd; 23591abb4a6SAndrii Nakryiko __u32 attach_btf_obj_fd; 2366aef10a4SAndrii Nakryiko __u32 attach_btf_id; 2376aef10a4SAndrii Nakryiko __u32 prog_ifindex; 2386aef10a4SAndrii Nakryiko __u32 prog_btf_fd; 2396aef10a4SAndrii Nakryiko __u32 prog_flags; 2406aef10a4SAndrii Nakryiko 2416aef10a4SAndrii Nakryiko __u32 func_info_rec_size; 2426aef10a4SAndrii Nakryiko const void *func_info; 2436aef10a4SAndrii Nakryiko __u32 func_info_cnt; 2446aef10a4SAndrii Nakryiko 2456aef10a4SAndrii Nakryiko __u32 line_info_rec_size; 2466aef10a4SAndrii Nakryiko const void *line_info; 2476aef10a4SAndrii Nakryiko __u32 line_info_cnt; 2486aef10a4SAndrii Nakryiko 2496aef10a4SAndrii Nakryiko __u32 log_level; 2506aef10a4SAndrii Nakryiko char *log_buf; 2516aef10a4SAndrii Nakryiko size_t log_buf_sz; 2526aef10a4SAndrii Nakryiko }; 2536aef10a4SAndrii Nakryiko 2546aef10a4SAndrii Nakryiko int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr); 2556aef10a4SAndrii Nakryiko 256612d05beSAndrii Nakryiko int bpf_object__section_size(const struct bpf_object *obj, const char *name, 257612d05beSAndrii Nakryiko __u32 *size); 258612d05beSAndrii Nakryiko int bpf_object__variable_offset(const struct bpf_object *obj, const char *name, 259612d05beSAndrii Nakryiko __u32 *off); 260a19f93cfSAndrii Nakryiko struct btf *btf_get_from_fd(int btf_fd, struct btf *base_btf); 261*67234743SAlexei Starovoitov void btf_get_kernel_prefix_kind(enum bpf_attach_type attach_type, 262*67234743SAlexei Starovoitov const char **prefix, int *kind); 263612d05beSAndrii Nakryiko 2644cedc0daSAndrii Nakryiko struct btf_ext_info { 2654cedc0daSAndrii Nakryiko /* 2664cedc0daSAndrii Nakryiko * info points to the individual info section (e.g. func_info and 2674cedc0daSAndrii Nakryiko * line_info) from the .BTF.ext. It does not include the __u32 rec_size. 2684cedc0daSAndrii Nakryiko */ 2694cedc0daSAndrii Nakryiko void *info; 2704cedc0daSAndrii Nakryiko __u32 rec_size; 2714cedc0daSAndrii Nakryiko __u32 len; 2724cedc0daSAndrii Nakryiko }; 2734cedc0daSAndrii Nakryiko 2744cedc0daSAndrii Nakryiko #define for_each_btf_ext_sec(seg, sec) \ 2754cedc0daSAndrii Nakryiko for (sec = (seg)->info; \ 2764cedc0daSAndrii Nakryiko (void *)sec < (seg)->info + (seg)->len; \ 2774cedc0daSAndrii Nakryiko sec = (void *)sec + sizeof(struct btf_ext_info_sec) + \ 2784cedc0daSAndrii Nakryiko (seg)->rec_size * sec->num_info) 2794cedc0daSAndrii Nakryiko 2804cedc0daSAndrii Nakryiko #define for_each_btf_ext_rec(seg, sec, i, rec) \ 2814cedc0daSAndrii Nakryiko for (i = 0, rec = (void *)&(sec)->data; \ 2824cedc0daSAndrii Nakryiko i < (sec)->num_info; \ 2834cedc0daSAndrii Nakryiko i++, rec = (void *)rec + (seg)->rec_size) 2844cedc0daSAndrii Nakryiko 28528b93c64SAndrii Nakryiko /* 28628b93c64SAndrii Nakryiko * The .BTF.ext ELF section layout defined as 28728b93c64SAndrii Nakryiko * struct btf_ext_header 28828b93c64SAndrii Nakryiko * func_info subsection 28928b93c64SAndrii Nakryiko * 29028b93c64SAndrii Nakryiko * The func_info subsection layout: 29128b93c64SAndrii Nakryiko * record size for struct bpf_func_info in the func_info subsection 29228b93c64SAndrii Nakryiko * struct btf_sec_func_info for section #1 29328b93c64SAndrii Nakryiko * a list of bpf_func_info records for section #1 29428b93c64SAndrii Nakryiko * where struct bpf_func_info mimics one in include/uapi/linux/bpf.h 29528b93c64SAndrii Nakryiko * but may not be identical 29628b93c64SAndrii Nakryiko * struct btf_sec_func_info for section #2 29728b93c64SAndrii Nakryiko * a list of bpf_func_info records for section #2 29828b93c64SAndrii Nakryiko * ...... 29928b93c64SAndrii Nakryiko * 30028b93c64SAndrii Nakryiko * Note that the bpf_func_info record size in .BTF.ext may not 30128b93c64SAndrii Nakryiko * be the same as the one defined in include/uapi/linux/bpf.h. 30228b93c64SAndrii Nakryiko * The loader should ensure that record_size meets minimum 30328b93c64SAndrii Nakryiko * requirement and pass the record as is to the kernel. The 30428b93c64SAndrii Nakryiko * kernel will handle the func_info properly based on its contents. 30528b93c64SAndrii Nakryiko */ 30628b93c64SAndrii Nakryiko struct btf_ext_header { 30728b93c64SAndrii Nakryiko __u16 magic; 30828b93c64SAndrii Nakryiko __u8 version; 30928b93c64SAndrii Nakryiko __u8 flags; 31028b93c64SAndrii Nakryiko __u32 hdr_len; 31128b93c64SAndrii Nakryiko 31228b93c64SAndrii Nakryiko /* All offsets are in bytes relative to the end of this header */ 31328b93c64SAndrii Nakryiko __u32 func_info_off; 31428b93c64SAndrii Nakryiko __u32 func_info_len; 31528b93c64SAndrii Nakryiko __u32 line_info_off; 31628b93c64SAndrii Nakryiko __u32 line_info_len; 31728b93c64SAndrii Nakryiko 31828b93c64SAndrii Nakryiko /* optional part of .BTF.ext header */ 31928b93c64SAndrii Nakryiko __u32 core_relo_off; 32028b93c64SAndrii Nakryiko __u32 core_relo_len; 32128b93c64SAndrii Nakryiko }; 32228b93c64SAndrii Nakryiko 3234cedc0daSAndrii Nakryiko struct btf_ext { 3244cedc0daSAndrii Nakryiko union { 3254cedc0daSAndrii Nakryiko struct btf_ext_header *hdr; 3264cedc0daSAndrii Nakryiko void *data; 3274cedc0daSAndrii Nakryiko }; 3284cedc0daSAndrii Nakryiko struct btf_ext_info func_info; 3294cedc0daSAndrii Nakryiko struct btf_ext_info line_info; 33028b93c64SAndrii Nakryiko struct btf_ext_info core_relo_info; 3314cedc0daSAndrii Nakryiko __u32 data_size; 3324cedc0daSAndrii Nakryiko }; 3334cedc0daSAndrii Nakryiko 3344cedc0daSAndrii Nakryiko struct btf_ext_info_sec { 3354cedc0daSAndrii Nakryiko __u32 sec_name_off; 3364cedc0daSAndrii Nakryiko __u32 num_info; 3374cedc0daSAndrii Nakryiko /* Followed by num_info * record_size number of bytes */ 338385bbf7bSGustavo A. R. Silva __u8 data[]; 3394cedc0daSAndrii Nakryiko }; 3404cedc0daSAndrii Nakryiko 3414cedc0daSAndrii Nakryiko /* The minimum bpf_func_info checked by the loader */ 3424cedc0daSAndrii Nakryiko struct bpf_func_info_min { 3434cedc0daSAndrii Nakryiko __u32 insn_off; 3444cedc0daSAndrii Nakryiko __u32 type_id; 3454cedc0daSAndrii Nakryiko }; 3464cedc0daSAndrii Nakryiko 3474cedc0daSAndrii Nakryiko /* The minimum bpf_line_info checked by the loader */ 3484cedc0daSAndrii Nakryiko struct bpf_line_info_min { 3494cedc0daSAndrii Nakryiko __u32 insn_off; 3504cedc0daSAndrii Nakryiko __u32 file_name_off; 3514cedc0daSAndrii Nakryiko __u32 line_off; 3524cedc0daSAndrii Nakryiko __u32 line_col; 3534cedc0daSAndrii Nakryiko }; 3544cedc0daSAndrii Nakryiko 35528b93c64SAndrii Nakryiko /* bpf_core_relo_kind encodes which aspect of captured field/type/enum value 35628b93c64SAndrii Nakryiko * has to be adjusted by relocations. 357511bb008SAndrii Nakryiko */ 35828b93c64SAndrii Nakryiko enum bpf_core_relo_kind { 359511bb008SAndrii Nakryiko BPF_FIELD_BYTE_OFFSET = 0, /* field byte offset */ 36028b93c64SAndrii Nakryiko BPF_FIELD_BYTE_SIZE = 1, /* field size in bytes */ 361511bb008SAndrii Nakryiko BPF_FIELD_EXISTS = 2, /* field existence in target kernel */ 36228b93c64SAndrii Nakryiko BPF_FIELD_SIGNED = 3, /* field signedness (0 - unsigned, 1 - signed) */ 36328b93c64SAndrii Nakryiko BPF_FIELD_LSHIFT_U64 = 4, /* bitfield-specific left bitshift */ 36428b93c64SAndrii Nakryiko BPF_FIELD_RSHIFT_U64 = 5, /* bitfield-specific right bitshift */ 3653fc32f40SAndrii Nakryiko BPF_TYPE_ID_LOCAL = 6, /* type ID in local BPF object */ 3663fc32f40SAndrii Nakryiko BPF_TYPE_ID_TARGET = 7, /* type ID in target kernel */ 3673fc32f40SAndrii Nakryiko BPF_TYPE_EXISTS = 8, /* type existence in target kernel */ 3683fc32f40SAndrii Nakryiko BPF_TYPE_SIZE = 9, /* type size in bytes */ 369eacaaed7SAndrii Nakryiko BPF_ENUMVAL_EXISTS = 10, /* enum value existence in target kernel */ 370eacaaed7SAndrii Nakryiko BPF_ENUMVAL_VALUE = 11, /* enum value integer value */ 371511bb008SAndrii Nakryiko }; 372511bb008SAndrii Nakryiko 37328b93c64SAndrii Nakryiko /* The minimum bpf_core_relo checked by the loader 3744cedc0daSAndrii Nakryiko * 37528b93c64SAndrii Nakryiko * CO-RE relocation captures the following data: 3764cedc0daSAndrii Nakryiko * - insn_off - instruction offset (in bytes) within a BPF program that needs 377511bb008SAndrii Nakryiko * its insn->imm field to be relocated with actual field info; 3784cedc0daSAndrii Nakryiko * - type_id - BTF type ID of the "root" (containing) entity of a relocatable 37928b93c64SAndrii Nakryiko * type or field; 3804cedc0daSAndrii Nakryiko * - access_str_off - offset into corresponding .BTF string section. String 38128b93c64SAndrii Nakryiko * interpretation depends on specific relocation kind: 38228b93c64SAndrii Nakryiko * - for field-based relocations, string encodes an accessed field using 38328b93c64SAndrii Nakryiko * a sequence of field and array indices, separated by colon (:). It's 38428b93c64SAndrii Nakryiko * conceptually very close to LLVM's getelementptr ([0]) instruction's 38528b93c64SAndrii Nakryiko * arguments for identifying offset to a field. 38628b93c64SAndrii Nakryiko * - for type-based relocations, strings is expected to be just "0"; 38728b93c64SAndrii Nakryiko * - for enum value-based relocations, string contains an index of enum 38828b93c64SAndrii Nakryiko * value within its enum type; 3894cedc0daSAndrii Nakryiko * 3904cedc0daSAndrii Nakryiko * Example to provide a better feel. 3914cedc0daSAndrii Nakryiko * 3924cedc0daSAndrii Nakryiko * struct sample { 3934cedc0daSAndrii Nakryiko * int a; 3944cedc0daSAndrii Nakryiko * struct { 3954cedc0daSAndrii Nakryiko * int b[10]; 3964cedc0daSAndrii Nakryiko * }; 3974cedc0daSAndrii Nakryiko * }; 3984cedc0daSAndrii Nakryiko * 3994cedc0daSAndrii Nakryiko * struct sample *s = ...; 4004cedc0daSAndrii Nakryiko * int x = &s->a; // encoded as "0:0" (a is field #0) 4014cedc0daSAndrii Nakryiko * int y = &s->b[5]; // encoded as "0:1:0:5" (anon struct is field #1, 4024cedc0daSAndrii Nakryiko * // b is field #0 inside anon struct, accessing elem #5) 4034cedc0daSAndrii Nakryiko * int z = &s[10]->b; // encoded as "10:1" (ptr is used as an array) 4044cedc0daSAndrii Nakryiko * 4054cedc0daSAndrii Nakryiko * type_id for all relocs in this example will capture BTF type id of 4064cedc0daSAndrii Nakryiko * `struct sample`. 4074cedc0daSAndrii Nakryiko * 4084cedc0daSAndrii Nakryiko * Such relocation is emitted when using __builtin_preserve_access_index() 4094cedc0daSAndrii Nakryiko * Clang built-in, passing expression that captures field address, e.g.: 4104cedc0daSAndrii Nakryiko * 4114cedc0daSAndrii Nakryiko * bpf_probe_read(&dst, sizeof(dst), 4124cedc0daSAndrii Nakryiko * __builtin_preserve_access_index(&src->a.b.c)); 4134cedc0daSAndrii Nakryiko * 414511bb008SAndrii Nakryiko * In this case Clang will emit field relocation recording necessary data to 4154cedc0daSAndrii Nakryiko * be able to find offset of embedded `a.b.c` field within `src` struct. 4164cedc0daSAndrii Nakryiko * 4174cedc0daSAndrii Nakryiko * [0] https://llvm.org/docs/LangRef.html#getelementptr-instruction 4184cedc0daSAndrii Nakryiko */ 41928b93c64SAndrii Nakryiko struct bpf_core_relo { 4204cedc0daSAndrii Nakryiko __u32 insn_off; 4214cedc0daSAndrii Nakryiko __u32 type_id; 4224cedc0daSAndrii Nakryiko __u32 access_str_off; 42328b93c64SAndrii Nakryiko enum bpf_core_relo_kind kind; 4244cedc0daSAndrii Nakryiko }; 4254cedc0daSAndrii Nakryiko 426f36e99a4SAndrii Nakryiko typedef int (*type_id_visit_fn)(__u32 *type_id, void *ctx); 427f36e99a4SAndrii Nakryiko typedef int (*str_off_visit_fn)(__u32 *str_off, void *ctx); 428f36e99a4SAndrii Nakryiko int btf_type_visit_type_ids(struct btf_type *t, type_id_visit_fn visit, void *ctx); 429f36e99a4SAndrii Nakryiko int btf_type_visit_str_offs(struct btf_type *t, str_off_visit_fn visit, void *ctx); 430f36e99a4SAndrii Nakryiko int btf_ext_visit_type_ids(struct btf_ext *btf_ext, type_id_visit_fn visit, void *ctx); 431f36e99a4SAndrii Nakryiko int btf_ext_visit_str_offs(struct btf_ext *btf_ext, str_off_visit_fn visit, void *ctx); 432f36e99a4SAndrii Nakryiko 433d7c4b398SAndrii Nakryiko #endif /* __LIBBPF_LIBBPF_INTERNAL_H */ 434