diff options
| author | Alexei Starovoitov <ast@kernel.org> | 2021-12-03 10:28:36 -0800 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2021-12-03 13:21:59 -0800 |
| commit | 78c1f8d0634cc35da613d844eda7c849fc50f643 (patch) | |
| tree | 107e51571324b5bc0cbf35095e5359d1f83115fe /kernel/bpf | |
| parent | 0bf40542c05ef62997738cd45eea553415adb045 (diff) | |
| download | linux-78c1f8d0634cc35da613d844eda7c849fc50f643.tar.bz2 | |
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: 29db4bea1d10 ("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
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/btf.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index ed4258cb0832..2a902a946f70 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -6742,8 +6742,16 @@ int bpf_core_apply(struct bpf_core_ctx *ctx, const struct bpf_core_relo *relo, { bool need_cands = relo->kind != BPF_CORE_TYPE_ID_LOCAL; struct bpf_core_cand_list cands = {}; + struct bpf_core_spec *specs; int err; + /* ~4k of temp memory necessary to convert LLVM spec like "0:1:0:5" + * into arrays of btf_ids of struct fields and array indices. + */ + specs = kcalloc(3, sizeof(*specs), GFP_KERNEL); + if (!specs) + return -ENOMEM; + if (need_cands) { struct bpf_cand_cache *cc; int i; @@ -6779,8 +6787,9 @@ int bpf_core_apply(struct bpf_core_ctx *ctx, const struct bpf_core_relo *relo, } err = bpf_core_apply_relo_insn((void *)ctx->log, insn, relo->insn_off / 8, - relo, relo_idx, ctx->btf, &cands); + relo, relo_idx, ctx->btf, &cands, specs); out: + kfree(specs); if (need_cands) { kfree(cands.cands); mutex_unlock(&cand_cache_mutex); |