RE: [PATCH] bpf: Replace 0 with BPF_K

From: John Fastabend
Date: Thu Jun 23 2022 - 19:44:41 EST


Simon wang wrote:
> From: Simon Wang <wangchuanguo@xxxxxxxxxx>
>
> Enhance readability.
>
> Signed-off-by: Simon Wang <wangchuanguo@xxxxxxxxxx>
> ---
> kernel/bpf/verifier.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> index 2859901ffbe3..29060f15daab 100644
> --- a/kernel/bpf/verifier.c
> +++ b/kernel/bpf/verifier.c
> @@ -9064,7 +9064,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
>
> if (opcode == BPF_END || opcode == BPF_NEG) {
> if (opcode == BPF_NEG) {
> - if (BPF_SRC(insn->code) != 0 ||
> + if (BPF_SRC(insn->code) != BPF_K ||
> insn->src_reg != BPF_REG_0 ||
> insn->off != 0 || insn->imm != 0) {
> verbose(env, "BPF_NEG uses reserved fields\n");
> --
> 2.27.0
>

Code is fine and seems everywhere else we do this check with

BPF_SRC(insn->code) != BPF_K

One thing though this should have [PATCH bpf-next] in the title so its
clear the code is targeted for bpf-next. Although in this case its
obvious from the content.

Acked-by: John Fastabend <john.fastabend@xxxxxxxxx>