On 01/29/2018 03:33 PM, Michael Holzheu wrote:
> Am Fri, 26 Jan 2018 23:33:42 +0100
> schrieb Daniel Borkmann <dan...@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?
I couldn't add it here since it was all part of the same series and
thus didn't have a stable commit id for future reference yet. Maybe
I should have just put the commit subject in this case; will do next
time.
>> remove the leftovers from s390x JIT.
>>
>> Signed-off-by: Daniel Borkmann <dan...@iogearbox.net>
>> Cc: Michael Holzheu <holz...@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 <holz...@linux.vnet.ibm.com>
Thanks for the review, Michael!
