100 lines · c
1/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */2/* Copyright (c) 2019 Facebook */3 4#ifndef __RELO_CORE_H5#define __RELO_CORE_H6 7#include <linux/bpf.h>8 9struct bpf_core_cand {10 const struct btf *btf;11 __u32 id;12};13 14/* dynamically sized list of type IDs and its associated struct btf */15struct bpf_core_cand_list {16 struct bpf_core_cand *cands;17 int len;18};19 20#define BPF_CORE_SPEC_MAX_LEN 6421 22/* represents BPF CO-RE field or array element accessor */23struct bpf_core_accessor {24 __u32 type_id; /* struct/union type or array element type */25 __u32 idx; /* field index or array index */26 const char *name; /* field name or NULL for array accessor */27};28 29struct bpf_core_spec {30 const struct btf *btf;31 /* high-level spec: named fields and array indices only */32 struct bpf_core_accessor spec[BPF_CORE_SPEC_MAX_LEN];33 /* original unresolved (no skip_mods_or_typedefs) root type ID */34 __u32 root_type_id;35 /* CO-RE relocation kind */36 enum bpf_core_relo_kind relo_kind;37 /* high-level spec length */38 int len;39 /* raw, low-level spec: 1-to-1 with accessor spec string */40 int raw_spec[BPF_CORE_SPEC_MAX_LEN];41 /* raw spec length */42 int raw_len;43 /* field bit offset represented by spec */44 __u32 bit_offset;45};46 47struct bpf_core_relo_res {48 /* expected value in the instruction, unless validate == false */49 __u64 orig_val;50 /* new value that needs to be patched up to */51 __u64 new_val;52 /* relocation unsuccessful, poison instruction, but don't fail load */53 bool poison;54 /* some relocations can't be validated against orig_val */55 bool validate;56 /* for field byte offset relocations or the forms:57 * *(T *)(rX + <off>) = rY58 * rX = *(T *)(rY + <off>),59 * we remember original and resolved field size to adjust direct60 * memory loads of pointers and integers; this is necessary for 32-bit61 * host kernel architectures, but also allows to automatically62 * relocate fields that were resized from, e.g., u32 to u64, etc.63 */64 bool fail_memsz_adjust;65 __u32 orig_sz;66 __u32 orig_type_id;67 __u32 new_sz;68 __u32 new_type_id;69};70 71int __bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,72 const struct btf *targ_btf, __u32 targ_id, int level);73int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,74 const struct btf *targ_btf, __u32 targ_id);75int __bpf_core_types_match(const struct btf *local_btf, __u32 local_id, const struct btf *targ_btf,76 __u32 targ_id, bool behind_ptr, int level);77int bpf_core_types_match(const struct btf *local_btf, __u32 local_id, const struct btf *targ_btf,78 __u32 targ_id);79 80size_t bpf_core_essential_name_len(const char *name);81 82int bpf_core_calc_relo_insn(const char *prog_name,83 const struct bpf_core_relo *relo, int relo_idx,84 const struct btf *local_btf,85 struct bpf_core_cand_list *cands,86 struct bpf_core_spec *specs_scratch,87 struct bpf_core_relo_res *targ_res);88 89int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn,90 int insn_idx, const struct bpf_core_relo *relo,91 int relo_idx, const struct bpf_core_relo_res *res);92 93int bpf_core_parse_spec(const char *prog_name, const struct btf *btf,94 const struct bpf_core_relo *relo,95 struct bpf_core_spec *spec);96 97int bpf_core_format_spec(char *buf, size_t buf_sz, const struct bpf_core_spec *spec);98 99#endif100