[PATCH bpf-next v2 1/8] bpf/verifier: Handle BPF_LOAD_ACQ instructions in insn_def_regno()

[Pu Lehui]

On 2025/5/7 11:42, Peilin Ye wrote:
> In preparation for supporting BPF load-acquire and store-release
> instructions for architectures where bpf_jit_needs_zext() returns true
> (e.g. riscv64), make insn_def_regno() handle load-acquires properly.
> 
> Acked-by: Björn Töpel <bjorn at kernel.org>
> Tested-by: Björn Töpel <bjorn at rivosinc.com> # QEMU/RVA23
> Signed-off-by: Peilin Ye <yepeilin at google.com>
> ---
>   kernel/bpf/verifier.c | 12 ++++++------
>   1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> index 99aa2c890e7b..28f5a7899bd6 100644
> --- a/kernel/bpf/verifier.c
> +++ b/kernel/bpf/verifier.c
> @@ -3649,16 +3649,16 @@ static int insn_def_regno(const struct bpf_insn *insn)
>   	case BPF_ST:
>   		return -1;
>   	case BPF_STX:
> -		if ((BPF_MODE(insn->code) == BPF_ATOMIC ||
> -		     BPF_MODE(insn->code) == BPF_PROBE_ATOMIC) &&
> -		    (insn->imm & BPF_FETCH)) {
> +		if (BPF_MODE(insn->code) == BPF_ATOMIC ||
> +		    BPF_MODE(insn->code) == BPF_PROBE_ATOMIC) {
>   			if (insn->imm == BPF_CMPXCHG)
>   				return BPF_REG_0;
> -			else
> +			else if (insn->imm == BPF_LOAD_ACQ)
> +				return insn->dst_reg;
> +			else if (insn->imm & BPF_FETCH)
>   				return insn->src_reg;
> -		} else {
> -			return -1;
>   		}
> +		return -1;
>   	default:
>   		return insn->dst_reg;
>   	}

lgtm, thanks
Reviewed-by: Pu Lehui <pulehui at huawei.com>