Re: [PATCH bpf-next 1/8] arm32, bpf: add support for 32-bit offset jmp instruction

[Russell King (Oracle)]

On Tue, Sep 05, 2023 at 09:06:14PM +0000, Puranjay Mohan wrote:
> The cpuv4 adds unconditional jump with 32-bit offset where the immediate
> field of the instruction is to be used to calculate the jump offset.
> 
> BPF_JA | BPF_K | BPF_JMP32 => gotol +imm => PC += imm.
> 
> Signed-off-by: Puranjay Mohan <puranjay12@xxxxxxxxx>
> ---
>  arch/arm/net/bpf_jit_32.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
> index 6a1c9fca5260..b26579da770e 100644
> --- a/arch/arm/net/bpf_jit_32.c
> +++ b/arch/arm/net/bpf_jit_32.c
> @@ -1761,10 +1761,15 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
>  		break;
>  	/* JMP OFF */
>  	case BPF_JMP | BPF_JA:
> +	case BPF_JMP32 | BPF_JA:
>  	{
> -		if (off == 0)
> +		if (BPF_CLASS(code) == BPF_JMP32 && imm != 0)
> +			jmp_offset = bpf2a32_offset(i + imm, i, ctx);
> +		else if (BPF_CLASS(code) == BPF_JMP &&  off != 0)

Please tidy up the coding style - one space between "&&" and "off"

Thanks.

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