diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2024-06-13 13:53:09 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2024-06-13 11:16:01 -0700 |
| commit | e73cd1cfc2177654e562b04f514be5f0f0b96da2 (patch) | |
| tree | 80e9183bca908b2452d45c87141e7b13c33502af /kernel | |
| parent | 92424801261d1564a0bb759da3cf3ccd69fdf5a2 (diff) | |
| download | linux-stable-e73cd1cfc2177654e562b04f514be5f0f0b96da2.tar.gz linux-stable-e73cd1cfc2177654e562b04f514be5f0f0b96da2.tar.bz2 linux-stable-e73cd1cfc2177654e562b04f514be5f0f0b96da2.zip | |
bpf: Reduce stack consumption in check_stack_write_fixed_off
The fake_reg moved into env->fake_reg given it consumes a lot of stack
space (120 bytes). Migrate the fake_reg in check_stack_write_fixed_off()
as well now that we have it.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20240613115310.25383-2-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/verifier.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index f455548ba46c..e5a0ba3bc38d 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -4549,11 +4549,12 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env, state->stack[spi].spilled_ptr.id = 0; } else if (!reg && !(off % BPF_REG_SIZE) && is_bpf_st_mem(insn) && env->bpf_capable) { - struct bpf_reg_state fake_reg = {}; + struct bpf_reg_state *tmp_reg = &env->fake_reg[0]; - __mark_reg_known(&fake_reg, insn->imm); - fake_reg.type = SCALAR_VALUE; - save_register_state(env, state, spi, &fake_reg, size); + memset(tmp_reg, 0, sizeof(*tmp_reg)); + __mark_reg_known(tmp_reg, insn->imm); + tmp_reg->type = SCALAR_VALUE; + save_register_state(env, state, spi, tmp_reg, size); } else if (reg && is_spillable_regtype(reg->type)) { /* register containing pointer is being spilled into stack */ if (size != BPF_REG_SIZE) { |