From: Michael Holzheu <holzheu@linux.vnet.ibm.com>
To: Daniel Borkmann <daniel@iogearbox.net>
Cc: ast@kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH bpf-next 07/13] bpf, s390x: remove obsolete exception handling from div/mod
Date: Mon, 29 Jan 2018 15:33:57 +0100 [thread overview]
Message-ID: <20180129153357.7e2cc0c8@TP-holzheu> (raw)
In-Reply-To: <20180126223348.11250-8-daniel@iogearbox.net>
Am Fri, 26 Jan 2018 23:33:42 +0100
schrieb Daniel Borkmann <daniel@iogearbox.net>:
> Since we've changed div/mod exception handling for src_reg in
> eBPF verifier itself,
Maybe add the commit that introduced that to the patch description?
> remove the leftovers from s390x JIT.
>
> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
> ---
> arch/s390/net/bpf_jit_comp.c | 10 ----------
> 1 file changed, 10 deletions(-)
>
> diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
> index e501887..78a19c9 100644
> --- a/arch/s390/net/bpf_jit_comp.c
> +++ b/arch/s390/net/bpf_jit_comp.c
> @@ -610,11 +610,6 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
> {
> int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
>
> - jit->seen |= SEEN_RET0;
> - /* ltr %src,%src (if src == 0 goto fail) */
> - EMIT2(0x1200, src_reg, src_reg);
> - /* jz <ret0> */
> - EMIT4_PCREL(0xa7840000, jit->ret0_ip - jit->prg);
> /* lhi %w0,0 */
> EMIT4_IMM(0xa7080000, REG_W0, 0);
> /* lr %w1,%dst */
> @@ -630,11 +625,6 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
> {
> int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
>
> - jit->seen |= SEEN_RET0;
> - /* ltgr %src,%src (if src == 0 goto fail) */
> - EMIT4(0xb9020000, src_reg, src_reg);
> - /* jz <ret0> */
> - EMIT4_PCREL(0xa7840000, jit->ret0_ip - jit->prg);
> /* lghi %w0,0 */
> EMIT4_IMM(0xa7090000, REG_W0, 0);
> /* lgr %w1,%dst */
If the check is done in the verifier now, this looks good to me.
Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
next prev parent reply other threads:[~2018-01-29 14:34 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-26 22:33 [PATCH bpf-next 00/13] BPF improvements and fixes Daniel Borkmann
2018-01-26 22:33 ` [PATCH bpf-next 01/13] bpf: xor of a/x in cbpf can be done in 32 bit alu Daniel Borkmann
2018-01-28 18:58 ` [PATCH bpf-next 01/13] bpf: xor of a/x in cbpf can be done Naveen N. Rao
2018-01-28 20:51 ` Daniel Borkmann
2018-01-26 22:33 ` [PATCH bpf-next 02/13] bpf: improve dead code sanitizing Daniel Borkmann
2018-01-26 22:33 ` [PATCH bpf-next 03/13] bpf: make unknown opcode handling more robust Daniel Borkmann
2018-01-26 22:33 ` [PATCH bpf-next 04/13] bpf: fix subprog verifier bypass by div/mod by 0 exception Daniel Borkmann
2018-01-26 22:33 ` [PATCH bpf-next 05/13] bpf, x86_64: remove obsolete exception handling from div/mod Daniel Borkmann
2018-01-26 22:33 ` [PATCH bpf-next 06/13] bpf, arm64: " Daniel Borkmann
2018-01-26 22:33 ` [PATCH bpf-next 07/13] bpf, s390x: " Daniel Borkmann
2018-01-29 14:33 ` Michael Holzheu [this message]
2018-01-29 15:52 ` Daniel Borkmann
2018-01-26 22:33 ` [PATCH bpf-next 08/13] bpf, ppc64: " Daniel Borkmann
2018-01-28 18:52 ` Naveen N. Rao
2018-01-26 22:33 ` [PATCH bpf-next 09/13] bpf, sparc64: " Daniel Borkmann
2018-01-26 22:33 ` [PATCH bpf-next 10/13] bpf, mips64: " Daniel Borkmann
2018-01-26 22:39 ` David Daney
2018-01-26 22:33 ` [PATCH bpf-next 11/13] bpf, mips64: remove unneeded zero check from div/mod with k Daniel Borkmann
2018-01-26 22:36 ` David Daney
2018-01-26 22:33 ` [PATCH bpf-next 12/13] bpf, arm: remove obsolete exception handling from div/mod Daniel Borkmann
2018-01-26 22:33 ` [PATCH bpf-next 13/13] bpf: add further test cases around div/mod and others Daniel Borkmann
2018-01-27 0:48 ` [PATCH bpf-next 00/13] BPF improvements and fixes Alexei Starovoitov
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