| /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ |
| |
| /* |
| * Internal libbpf helpers. |
| * |
| * Copyright (c) 2019 Facebook |
| */ |
| |
| #ifndef __LIBBPF_LIBBPF_INTERNAL_H |
| #define __LIBBPF_LIBBPF_INTERNAL_H |
| |
| #include <stdlib.h> |
| #include <limits.h> |
| #include <errno.h> |
| #include <linux/err.h> |
| #include "libbpf_legacy.h" |
| |
| /* make sure libbpf doesn't use kernel-only integer typedefs */ |
| #pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 |
| |
| /* prevent accidental re-addition of reallocarray() */ |
| #pragma GCC poison reallocarray |
| |
| #include "libbpf.h" |
| #include "btf.h" |
| |
| #ifndef EM_BPF |
| #define EM_BPF 247 |
| #endif |
| |
| #ifndef R_BPF_64_64 |
| #define R_BPF_64_64 1 |
| #endif |
| #ifndef R_BPF_64_ABS64 |
| #define R_BPF_64_ABS64 2 |
| #endif |
| #ifndef R_BPF_64_ABS32 |
| #define R_BPF_64_ABS32 3 |
| #endif |
| #ifndef R_BPF_64_32 |
| #define R_BPF_64_32 10 |
| #endif |
| |
| #ifndef SHT_LLVM_ADDRSIG |
| #define SHT_LLVM_ADDRSIG 0x6FFF4C03 |
| #endif |
| |
| /* if libelf is old and doesn't support mmap(), fall back to read() */ |
| #ifndef ELF_C_READ_MMAP |
| #define ELF_C_READ_MMAP ELF_C_READ |
| #endif |
| |
| /* Older libelf all end up in this expression, for both 32 and 64 bit */ |
| #ifndef GELF_ST_VISIBILITY |
| #define GELF_ST_VISIBILITY(o) ((o) & 0x03) |
| #endif |
| |
| #define BTF_INFO_ENC(kind, kind_flag, vlen) \ |
| ((!!(kind_flag) << 31) | ((kind) << 24) | ((vlen) & BTF_MAX_VLEN)) |
| #define BTF_TYPE_ENC(name, info, size_or_type) (name), (info), (size_or_type) |
| #define BTF_INT_ENC(encoding, bits_offset, nr_bits) \ |
| ((encoding) << 24 | (bits_offset) << 16 | (nr_bits)) |
| #define BTF_TYPE_INT_ENC(name, encoding, bits_offset, bits, sz) \ |
| BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_INT, 0, 0), sz), \ |
| BTF_INT_ENC(encoding, bits_offset, bits) |
| #define BTF_MEMBER_ENC(name, type, bits_offset) (name), (type), (bits_offset) |
| #define BTF_PARAM_ENC(name, type) (name), (type) |
| #define BTF_VAR_SECINFO_ENC(type, offset, size) (type), (offset), (size) |
| #define BTF_TYPE_FLOAT_ENC(name, sz) \ |
| BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_FLOAT, 0, 0), sz) |
| |
| #ifndef likely |
| #define likely(x) __builtin_expect(!!(x), 1) |
| #endif |
| #ifndef unlikely |
| #define unlikely(x) __builtin_expect(!!(x), 0) |
| #endif |
| #ifndef min |
| # define min(x, y) ((x) < (y) ? (x) : (y)) |
| #endif |
| #ifndef max |
| # define max(x, y) ((x) < (y) ? (y) : (x)) |
| #endif |
| #ifndef offsetofend |
| # define offsetofend(TYPE, FIELD) \ |
| (offsetof(TYPE, FIELD) + sizeof(((TYPE *)0)->FIELD)) |
| #endif |
| |
| /* Symbol versioning is different between static and shared library. |
| * Properly versioned symbols are needed for shared library, but |
| * only the symbol of the new version is needed for static library. |
| */ |
| #ifdef SHARED |
| # define COMPAT_VERSION(internal_name, api_name, version) \ |
| asm(".symver " #internal_name "," #api_name "@" #version); |
| # define DEFAULT_VERSION(internal_name, api_name, version) \ |
| asm(".symver " #internal_name "," #api_name "@@" #version); |
| #else |
| # define COMPAT_VERSION(internal_name, api_name, version) |
| # define DEFAULT_VERSION(internal_name, api_name, version) \ |
| extern typeof(internal_name) api_name \ |
| __attribute__((alias(#internal_name))); |
| #endif |
| |
| extern void libbpf_print(enum libbpf_print_level level, |
| const char *format, ...) |
| __attribute__((format(printf, 2, 3))); |
| |
| #define __pr(level, fmt, ...) \ |
| do { \ |
| libbpf_print(level, "libbpf: " fmt, ##__VA_ARGS__); \ |
| } while (0) |
| |
| #define pr_warn(fmt, ...) __pr(LIBBPF_WARN, fmt, ##__VA_ARGS__) |
| #define pr_info(fmt, ...) __pr(LIBBPF_INFO, fmt, ##__VA_ARGS__) |
| #define pr_debug(fmt, ...) __pr(LIBBPF_DEBUG, fmt, ##__VA_ARGS__) |
| |
| #ifndef __has_builtin |
| #define __has_builtin(x) 0 |
| #endif |
| /* |
| * Re-implement glibc's reallocarray() for libbpf internal-only use. |
| * reallocarray(), unfortunately, is not available in all versions of glibc, |
| * so requires extra feature detection and using reallocarray() stub from |
| * <tools/libc_compat.h> and COMPAT_NEED_REALLOCARRAY. All this complicates |
| * build of libbpf unnecessarily and is just a maintenance burden. Instead, |
| * it's trivial to implement libbpf-specific internal version and use it |
| * throughout libbpf. |
| */ |
| static inline void *libbpf_reallocarray(void *ptr, size_t nmemb, size_t size) |
| { |
| size_t total; |
| |
| #if __has_builtin(__builtin_mul_overflow) |
| if (unlikely(__builtin_mul_overflow(nmemb, size, &total))) |
| return NULL; |
| #else |
| if (size == 0 || nmemb > ULONG_MAX / size) |
| return NULL; |
| total = nmemb * size; |
| #endif |
| return realloc(ptr, total); |
| } |
| |
| struct btf; |
| struct btf_type; |
| |
| struct btf_type *btf_type_by_id(struct btf *btf, __u32 type_id); |
| const char *btf_kind_str(const struct btf_type *t); |
| const struct btf_type *skip_mods_and_typedefs(const struct btf *btf, __u32 id, __u32 *res_id); |
| |
| static inline enum btf_func_linkage btf_func_linkage(const struct btf_type *t) |
| { |
| return (enum btf_func_linkage)(int)btf_vlen(t); |
| } |
| |
| static inline __u32 btf_type_info(int kind, int vlen, int kflag) |
| { |
| return (kflag << 31) | (kind << 24) | vlen; |
| } |
| |
| enum map_def_parts { |
| MAP_DEF_MAP_TYPE = 0x001, |
| MAP_DEF_KEY_TYPE = 0x002, |
| MAP_DEF_KEY_SIZE = 0x004, |
| MAP_DEF_VALUE_TYPE = 0x008, |
| MAP_DEF_VALUE_SIZE = 0x010, |
| MAP_DEF_MAX_ENTRIES = 0x020, |
| MAP_DEF_MAP_FLAGS = 0x040, |
| MAP_DEF_NUMA_NODE = 0x080, |
| MAP_DEF_PINNING = 0x100, |
| MAP_DEF_INNER_MAP = 0x200, |
| |
| MAP_DEF_ALL = 0x3ff, /* combination of all above */ |
| }; |
| |
| struct btf_map_def { |
| enum map_def_parts parts; |
| __u32 map_type; |
| __u32 key_type_id; |
| __u32 key_size; |
| __u32 value_type_id; |
| __u32 value_size; |
| __u32 max_entries; |
| __u32 map_flags; |
| __u32 numa_node; |
| __u32 pinning; |
| }; |
| |
| int parse_btf_map_def(const char *map_name, struct btf *btf, |
| const struct btf_type *def_t, bool strict, |
| struct btf_map_def *map_def, struct btf_map_def *inner_def); |
| |
| void *libbpf_add_mem(void **data, size_t *cap_cnt, size_t elem_sz, |
| size_t cur_cnt, size_t max_cnt, size_t add_cnt); |
| int libbpf_ensure_mem(void **data, size_t *cap_cnt, size_t elem_sz, size_t need_cnt); |
| |
| static inline bool libbpf_validate_opts(const char *opts, |
| size_t opts_sz, size_t user_sz, |
| const char *type_name) |
| { |
| if (user_sz < sizeof(size_t)) { |
| pr_warn("%s size (%zu) is too small\n", type_name, user_sz); |
| return false; |
| } |
| if (user_sz > opts_sz) { |
| size_t i; |
| |
| for (i = opts_sz; i < user_sz; i++) { |
| if (opts[i]) { |
| pr_warn("%s has non-zero extra bytes\n", |
| type_name); |
| return false; |
| } |
| } |
| } |
| return true; |
| } |
| |
| #define OPTS_VALID(opts, type) \ |
| (!(opts) || libbpf_validate_opts((const char *)opts, \ |
| offsetofend(struct type, \ |
| type##__last_field), \ |
| (opts)->sz, #type)) |
| #define OPTS_HAS(opts, field) \ |
| ((opts) && opts->sz >= offsetofend(typeof(*(opts)), field)) |
| #define OPTS_GET(opts, field, fallback_value) \ |
| (OPTS_HAS(opts, field) ? (opts)->field : fallback_value) |
| #define OPTS_SET(opts, field, value) \ |
| do { \ |
| if (OPTS_HAS(opts, field)) \ |
| (opts)->field = value; \ |
| } while (0) |
| |
| int parse_cpu_mask_str(const char *s, bool **mask, int *mask_sz); |
| int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz); |
| int libbpf__load_raw_btf(const char *raw_types, size_t types_len, |
| const char *str_sec, size_t str_len); |
| |
| struct bpf_prog_load_params { |
| enum bpf_prog_type prog_type; |
| enum bpf_attach_type expected_attach_type; |
| const char *name; |
| const struct bpf_insn *insns; |
| size_t insn_cnt; |
| const char *license; |
| __u32 kern_version; |
| __u32 attach_prog_fd; |
| __u32 attach_btf_obj_fd; |
| __u32 attach_btf_id; |
| __u32 prog_ifindex; |
| __u32 prog_btf_fd; |
| __u32 prog_flags; |
| |
| __u32 func_info_rec_size; |
| const void *func_info; |
| __u32 func_info_cnt; |
| |
| __u32 line_info_rec_size; |
| const void *line_info; |
| __u32 line_info_cnt; |
| |
| __u32 log_level; |
| char *log_buf; |
| size_t log_buf_sz; |
| }; |
| |
| int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr); |
| |
| int bpf_object__section_size(const struct bpf_object *obj, const char *name, |
| __u32 *size); |
| int bpf_object__variable_offset(const struct bpf_object *obj, const char *name, |
| __u32 *off); |
| struct btf *btf_get_from_fd(int btf_fd, struct btf *base_btf); |
| void btf_get_kernel_prefix_kind(enum bpf_attach_type attach_type, |
| const char **prefix, int *kind); |
| |
| struct btf_ext_info { |
| /* |
| * info points to the individual info section (e.g. func_info and |
| * line_info) from the .BTF.ext. It does not include the __u32 rec_size. |
| */ |
| void *info; |
| __u32 rec_size; |
| __u32 len; |
| }; |
| |
| #define for_each_btf_ext_sec(seg, sec) \ |
| for (sec = (seg)->info; \ |
| (void *)sec < (seg)->info + (seg)->len; \ |
| sec = (void *)sec + sizeof(struct btf_ext_info_sec) + \ |
| (seg)->rec_size * sec->num_info) |
| |
| #define for_each_btf_ext_rec(seg, sec, i, rec) \ |
| for (i = 0, rec = (void *)&(sec)->data; \ |
| i < (sec)->num_info; \ |
| i++, rec = (void *)rec + (seg)->rec_size) |
| |
| /* |
| * The .BTF.ext ELF section layout defined as |
| * struct btf_ext_header |
| * func_info subsection |
| * |
| * The func_info subsection layout: |
| * record size for struct bpf_func_info in the func_info subsection |
| * struct btf_sec_func_info for section #1 |
| * a list of bpf_func_info records for section #1 |
| * where struct bpf_func_info mimics one in include/uapi/linux/bpf.h |
| * but may not be identical |
| * struct btf_sec_func_info for section #2 |
| * a list of bpf_func_info records for section #2 |
| * ...... |
| * |
| * Note that the bpf_func_info record size in .BTF.ext may not |
| * be the same as the one defined in include/uapi/linux/bpf.h. |
| * The loader should ensure that record_size meets minimum |
| * requirement and pass the record as is to the kernel. The |
| * kernel will handle the func_info properly based on its contents. |
| */ |
| struct btf_ext_header { |
| __u16 magic; |
| __u8 version; |
| __u8 flags; |
| __u32 hdr_len; |
| |
| /* All offsets are in bytes relative to the end of this header */ |
| __u32 func_info_off; |
| __u32 func_info_len; |
| __u32 line_info_off; |
| __u32 line_info_len; |
| |
| /* optional part of .BTF.ext header */ |
| __u32 core_relo_off; |
| __u32 core_relo_len; |
| }; |
| |
| struct btf_ext { |
| union { |
| struct btf_ext_header *hdr; |
| void *data; |
| }; |
| struct btf_ext_info func_info; |
| struct btf_ext_info line_info; |
| struct btf_ext_info core_relo_info; |
| __u32 data_size; |
| }; |
| |
| struct btf_ext_info_sec { |
| __u32 sec_name_off; |
| __u32 num_info; |
| /* Followed by num_info * record_size number of bytes */ |
| __u8 data[]; |
| }; |
| |
| /* The minimum bpf_func_info checked by the loader */ |
| struct bpf_func_info_min { |
| __u32 insn_off; |
| __u32 type_id; |
| }; |
| |
| /* The minimum bpf_line_info checked by the loader */ |
| struct bpf_line_info_min { |
| __u32 insn_off; |
| __u32 file_name_off; |
| __u32 line_off; |
| __u32 line_col; |
| }; |
| |
| /* bpf_core_relo_kind encodes which aspect of captured field/type/enum value |
| * has to be adjusted by relocations. |
| */ |
| enum bpf_core_relo_kind { |
| BPF_FIELD_BYTE_OFFSET = 0, /* field byte offset */ |
| BPF_FIELD_BYTE_SIZE = 1, /* field size in bytes */ |
| BPF_FIELD_EXISTS = 2, /* field existence in target kernel */ |
| BPF_FIELD_SIGNED = 3, /* field signedness (0 - unsigned, 1 - signed) */ |
| BPF_FIELD_LSHIFT_U64 = 4, /* bitfield-specific left bitshift */ |
| BPF_FIELD_RSHIFT_U64 = 5, /* bitfield-specific right bitshift */ |
| BPF_TYPE_ID_LOCAL = 6, /* type ID in local BPF object */ |
| BPF_TYPE_ID_TARGET = 7, /* type ID in target kernel */ |
| BPF_TYPE_EXISTS = 8, /* type existence in target kernel */ |
| BPF_TYPE_SIZE = 9, /* type size in bytes */ |
| BPF_ENUMVAL_EXISTS = 10, /* enum value existence in target kernel */ |
| BPF_ENUMVAL_VALUE = 11, /* enum value integer value */ |
| }; |
| |
| /* The minimum bpf_core_relo checked by the loader |
| * |
| * CO-RE relocation captures the following data: |
| * - insn_off - instruction offset (in bytes) within a BPF program that needs |
| * its insn->imm field to be relocated with actual field info; |
| * - type_id - BTF type ID of the "root" (containing) entity of a relocatable |
| * type or field; |
| * - access_str_off - offset into corresponding .BTF string section. String |
| * interpretation depends on specific relocation kind: |
| * - for field-based relocations, string encodes an accessed field using |
| * a sequence of field and array indices, separated by colon (:). It's |
| * conceptually very close to LLVM's getelementptr ([0]) instruction's |
| * arguments for identifying offset to a field. |
| * - for type-based relocations, strings is expected to be just "0"; |
| * - for enum value-based relocations, string contains an index of enum |
| * value within its enum type; |
| * |
| * Example to provide a better feel. |
| * |
| * struct sample { |
| * int a; |
| * struct { |
| * int b[10]; |
| * }; |
| * }; |
| * |
| * struct sample *s = ...; |
| * int x = &s->a; // encoded as "0:0" (a is field #0) |
| * int y = &s->b[5]; // encoded as "0:1:0:5" (anon struct is field #1, |
| * // b is field #0 inside anon struct, accessing elem #5) |
| * int z = &s[10]->b; // encoded as "10:1" (ptr is used as an array) |
| * |
| * type_id for all relocs in this example will capture BTF type id of |
| * `struct sample`. |
| * |
| * Such relocation is emitted when using __builtin_preserve_access_index() |
| * Clang built-in, passing expression that captures field address, e.g.: |
| * |
| * bpf_probe_read(&dst, sizeof(dst), |
| * __builtin_preserve_access_index(&src->a.b.c)); |
| * |
| * In this case Clang will emit field relocation recording necessary data to |
| * be able to find offset of embedded `a.b.c` field within `src` struct. |
| * |
| * [0] https://llvm.org/docs/LangRef.html#getelementptr-instruction |
| */ |
| struct bpf_core_relo { |
| __u32 insn_off; |
| __u32 type_id; |
| __u32 access_str_off; |
| enum bpf_core_relo_kind kind; |
| }; |
| |
| typedef int (*type_id_visit_fn)(__u32 *type_id, void *ctx); |
| typedef int (*str_off_visit_fn)(__u32 *str_off, void *ctx); |
| int btf_type_visit_type_ids(struct btf_type *t, type_id_visit_fn visit, void *ctx); |
| int btf_type_visit_str_offs(struct btf_type *t, str_off_visit_fn visit, void *ctx); |
| int btf_ext_visit_type_ids(struct btf_ext *btf_ext, type_id_visit_fn visit, void *ctx); |
| int btf_ext_visit_str_offs(struct btf_ext *btf_ext, str_off_visit_fn visit, void *ctx); |
| |
| extern enum libbpf_strict_mode libbpf_mode; |
| |
| /* handle direct returned errors */ |
| static inline int libbpf_err(int ret) |
| { |
| if (ret < 0) |
| errno = -ret; |
| return ret; |
| } |
| |
| /* handle errno-based (e.g., syscall or libc) errors according to libbpf's |
| * strict mode settings |
| */ |
| static inline int libbpf_err_errno(int ret) |
| { |
| if (libbpf_mode & LIBBPF_STRICT_DIRECT_ERRS) |
| /* errno is already assumed to be set on error */ |
| return ret < 0 ? -errno : ret; |
| |
| /* legacy: on error return -1 directly and don't touch errno */ |
| return ret; |
| } |
| |
| /* handle error for pointer-returning APIs, err is assumed to be < 0 always */ |
| static inline void *libbpf_err_ptr(int err) |
| { |
| /* set errno on error, this doesn't break anything */ |
| errno = -err; |
| |
| if (libbpf_mode & LIBBPF_STRICT_CLEAN_PTRS) |
| return NULL; |
| |
| /* legacy: encode err as ptr */ |
| return ERR_PTR(err); |
| } |
| |
| /* handle pointer-returning APIs' error handling */ |
| static inline void *libbpf_ptr(void *ret) |
| { |
| /* set errno on error, this doesn't break anything */ |
| if (IS_ERR(ret)) |
| errno = -PTR_ERR(ret); |
| |
| if (libbpf_mode & LIBBPF_STRICT_CLEAN_PTRS) |
| return IS_ERR(ret) ? NULL : ret; |
| |
| /* legacy: pass-through original pointer */ |
| return ret; |
| } |
| |
| #endif /* __LIBBPF_LIBBPF_INTERNAL_H */ |