linux-stable/tools/lib/bpf/relo_core.h
Alexei Starovoitov 78c1f8d063 libbpf: Reduce bpf_core_apply_relo_insn() stack usage.
Reduce bpf_core_apply_relo_insn() stack usage and bump
BPF_CORE_SPEC_MAX_LEN limit back to 64.

Fixes: 29db4bea1d ("bpf: Prepare relo_core.c for kernel duty.")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211203182836.16646-1-alexei.starovoitov@gmail.com
2021-12-03 13:21:59 -08:00

57 lines
1.6 KiB
C

/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
/* Copyright (c) 2019 Facebook */
#ifndef __RELO_CORE_H
#define __RELO_CORE_H
#include <linux/bpf.h>
struct bpf_core_cand {
const struct btf *btf;
__u32 id;
};
/* dynamically sized list of type IDs and its associated struct btf */
struct bpf_core_cand_list {
struct bpf_core_cand *cands;
int len;
};
#define BPF_CORE_SPEC_MAX_LEN 64
/* represents BPF CO-RE field or array element accessor */
struct bpf_core_accessor {
__u32 type_id; /* struct/union type or array element type */
__u32 idx; /* field index or array index */
const char *name; /* field name or NULL for array accessor */
};
struct bpf_core_spec {
const struct btf *btf;
/* high-level spec: named fields and array indices only */
struct bpf_core_accessor spec[BPF_CORE_SPEC_MAX_LEN];
/* original unresolved (no skip_mods_or_typedefs) root type ID */
__u32 root_type_id;
/* CO-RE relocation kind */
enum bpf_core_relo_kind relo_kind;
/* high-level spec length */
int len;
/* raw, low-level spec: 1-to-1 with accessor spec string */
int raw_spec[BPF_CORE_SPEC_MAX_LEN];
/* raw spec length */
int raw_len;
/* field bit offset represented by spec */
__u32 bit_offset;
};
int bpf_core_apply_relo_insn(const char *prog_name,
struct bpf_insn *insn, int insn_idx,
const struct bpf_core_relo *relo, int relo_idx,
const struct btf *local_btf,
struct bpf_core_cand_list *cands,
struct bpf_core_spec *specs_scratch);
int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,
const struct btf *targ_btf, __u32 targ_id);
size_t bpf_core_essential_name_len(const char *name);
#endif