| /* 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 "libbpf.h" |
| |
| #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) |
| |
| #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 |
| |
| 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_warning(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__) |
| |
| int libbpf__load_raw_btf(const char *raw_types, size_t types_len, |
| const char *str_sec, size_t str_len); |
| |
| 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) |
| |
| 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 offset_reloc_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[0]; |
| }; |
| |
| /* 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; |
| }; |
| |
| /* The minimum bpf_offset_reloc checked by the loader |
| * |
| * Offset 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 offset; |
| * - type_id - BTF type ID of the "root" (containing) entity of a relocatable |
| * offset; |
| * - access_str_off - offset into corresponding .BTF string section. String |
| * itself encodes an accessed field using a sequence of field and array |
| * indicies, separated by colon (:). It's conceptually very close to LLVM's |
| * getelementptr ([0]) instruction's arguments for identifying offset to |
| * a field. |
| * |
| * 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 offset 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_offset_reloc { |
| __u32 insn_off; |
| __u32 type_id; |
| __u32 access_str_off; |
| }; |
| |
| #endif /* __LIBBPF_LIBBPF_INTERNAL_H */ |