1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
4 * Internal libbpf helpers.
6 * Copyright (c) 2019 Facebook
9 #ifndef __LIBBPF_LIBBPF_INTERNAL_H
10 #define __LIBBPF_LIBBPF_INTERNAL_H
14 #define BTF_INFO_ENC(kind, kind_flag, vlen) \
15 ((!!(kind_flag) << 31) | ((kind) << 24) | ((vlen) & BTF_MAX_VLEN))
16 #define BTF_TYPE_ENC(name, info, size_or_type) (name), (info), (size_or_type)
17 #define BTF_INT_ENC(encoding, bits_offset, nr_bits) \
18 ((encoding) << 24 | (bits_offset) << 16 | (nr_bits))
19 #define BTF_TYPE_INT_ENC(name, encoding, bits_offset, bits, sz) \
20 BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_INT, 0, 0), sz), \
21 BTF_INT_ENC(encoding, bits_offset, bits)
22 #define BTF_MEMBER_ENC(name, type, bits_offset) (name), (type), (bits_offset)
23 #define BTF_PARAM_ENC(name, type) (name), (type)
24 #define BTF_VAR_SECINFO_ENC(type, offset, size) (type), (offset), (size)
27 # define min(x, y) ((x) < (y) ? (x) : (y))
30 # define max(x, y) ((x) < (y) ? (y) : (x))
33 # define offsetofend(TYPE, FIELD) \
34 (offsetof(TYPE, FIELD) + sizeof(((TYPE *)0)->FIELD))
37 extern void libbpf_print(enum libbpf_print_level level,
38 const char *format, ...)
39 __attribute__((format(printf, 2, 3)));
41 #define __pr(level, fmt, ...) \
43 libbpf_print(level, "libbpf: " fmt, ##__VA_ARGS__); \
46 #define pr_warning(fmt, ...) __pr(LIBBPF_WARN, fmt, ##__VA_ARGS__)
47 #define pr_info(fmt, ...) __pr(LIBBPF_INFO, fmt, ##__VA_ARGS__)
48 #define pr_debug(fmt, ...) __pr(LIBBPF_DEBUG, fmt, ##__VA_ARGS__)
50 int libbpf__load_raw_btf(const char *raw_types, size_t types_len,
51 const char *str_sec, size_t str_len);
55 * info points to the individual info section (e.g. func_info and
56 * line_info) from the .BTF.ext. It does not include the __u32 rec_size.
63 #define for_each_btf_ext_sec(seg, sec) \
64 for (sec = (seg)->info; \
65 (void *)sec < (seg)->info + (seg)->len; \
66 sec = (void *)sec + sizeof(struct btf_ext_info_sec) + \
67 (seg)->rec_size * sec->num_info)
69 #define for_each_btf_ext_rec(seg, sec, i, rec) \
70 for (i = 0, rec = (void *)&(sec)->data; \
71 i < (sec)->num_info; \
72 i++, rec = (void *)rec + (seg)->rec_size)
76 struct btf_ext_header *hdr;
79 struct btf_ext_info func_info;
80 struct btf_ext_info line_info;
81 struct btf_ext_info offset_reloc_info;
85 struct btf_ext_info_sec {
88 /* Followed by num_info * record_size number of bytes */
92 /* The minimum bpf_func_info checked by the loader */
93 struct bpf_func_info_min {
98 /* The minimum bpf_line_info checked by the loader */
99 struct bpf_line_info_min {
106 /* The minimum bpf_offset_reloc checked by the loader
108 * Offset relocation captures the following data:
109 * - insn_off - instruction offset (in bytes) within a BPF program that needs
110 * its insn->imm field to be relocated with actual offset;
111 * - type_id - BTF type ID of the "root" (containing) entity of a relocatable
113 * - access_str_off - offset into corresponding .BTF string section. String
114 * itself encodes an accessed field using a sequence of field and array
115 * indicies, separated by colon (:). It's conceptually very close to LLVM's
116 * getelementptr ([0]) instruction's arguments for identifying offset to
119 * Example to provide a better feel.
128 * struct sample *s = ...;
129 * int x = &s->a; // encoded as "0:0" (a is field #0)
130 * int y = &s->b[5]; // encoded as "0:1:0:5" (anon struct is field #1,
131 * // b is field #0 inside anon struct, accessing elem #5)
132 * int z = &s[10]->b; // encoded as "10:1" (ptr is used as an array)
134 * type_id for all relocs in this example will capture BTF type id of
137 * Such relocation is emitted when using __builtin_preserve_access_index()
138 * Clang built-in, passing expression that captures field address, e.g.:
140 * bpf_probe_read(&dst, sizeof(dst),
141 * __builtin_preserve_access_index(&src->a.b.c));
143 * In this case Clang will emit offset relocation recording necessary data to
144 * be able to find offset of embedded `a.b.c` field within `src` struct.
146 * [0] https://llvm.org/docs/LangRef.html#getelementptr-instruction
148 struct bpf_offset_reloc {
151 __u32 access_str_off;
154 #endif /* __LIBBPF_LIBBPF_INTERNAL_H */