netdev - Re: [PATCH bpf-next 08/13] bpf, ppc64: remove obsolete exception handling from div/mod

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Date:   Mon, 29 Jan 2018 00:22:37 +0530
From:   "Naveen N. Rao" <naveen.n.rao@...ux.vnet.ibm.com>
To:     ast@...nel.org, Daniel Borkmann <daniel@...earbox.net>
Cc:     netdev@...r.kernel.org
Subject: Re: [PATCH bpf-next 08/13] bpf, ppc64: remove obsolete exception
 handling from div/mod

Daniel Borkmann wrote:
> Since we've changed div/mod exception handling for src_reg in
> eBPF verifier itself, remove the leftovers from ppc64 JIT.
> 
> Signed-off-by: Daniel Borkmann <daniel@...earbox.net>
> Cc: Naveen N. Rao <naveen.n.rao@...ux.vnet.ibm.com>
> ---
>  arch/powerpc/net/bpf_jit_comp64.c | 8 --------
>  1 file changed, 8 deletions(-)

Probably too late, but none the less:
Acked-by: Naveen N. Rao <naveen.n.rao@...ux.vnet.ibm.com>

Thanks,
Naveen

> 
> diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
> index 217a78e..0a34b0c 100644
> --- a/arch/powerpc/net/bpf_jit_comp64.c
> +++ b/arch/powerpc/net/bpf_jit_comp64.c
> @@ -381,10 +381,6 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
>  			goto bpf_alu32_trunc;
>  		case BPF_ALU | BPF_DIV | BPF_X: /* (u32) dst /= (u32) src */
>  		case BPF_ALU | BPF_MOD | BPF_X: /* (u32) dst %= (u32) src */
> -			PPC_CMPWI(src_reg, 0);
> -			PPC_BCC_SHORT(COND_NE, (ctx->idx * 4) + 12);
> -			PPC_LI(b2p[BPF_REG_0], 0);
> -			PPC_JMP(exit_addr);
>  			if (BPF_OP(code) == BPF_MOD) {
>  				PPC_DIVWU(b2p[TMP_REG_1], dst_reg, src_reg);
>  				PPC_MULW(b2p[TMP_REG_1], src_reg,
> @@ -395,10 +391,6 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
>  			goto bpf_alu32_trunc;
>  		case BPF_ALU64 | BPF_DIV | BPF_X: /* dst /= src */
>  		case BPF_ALU64 | BPF_MOD | BPF_X: /* dst %= src */
> -			PPC_CMPDI(src_reg, 0);
> -			PPC_BCC_SHORT(COND_NE, (ctx->idx * 4) + 12);
> -			PPC_LI(b2p[BPF_REG_0], 0);
> -			PPC_JMP(exit_addr);
>  			if (BPF_OP(code) == BPF_MOD) {
>  				PPC_DIVD(b2p[TMP_REG_1], dst_reg, src_reg);
>  				PPC_MULD(b2p[TMP_REG_1], src_reg,
> -- 
> 2.9.5
> 
>