Subject: Re: [PATCH v2 net-next 3/3] ARM: net: bpf_jit_32: support BPF_S_ANC_SECCOMP_LD_W instruction

From: Nicolas Schichan <[email-masked]>
Date: Mon, 29 Apr 2013 14:39:29 +0200

On 04/27/2013 08:32 PM, Xi Wang wrote:
> On Sat, Apr 27, 2013 at 2:27 AM, Daniel Borkmann <[email-masked]> wrote:
>> Arent't you doing here a similar thing in terms of getting arch as Eric
>> criticized (Nicolas' implementation does not use that part btw.)? Also,
>> even if it would be possible here, now your 2 JIT implementations differ
>> in behaviour. I think this is unintended.
>
> Eric's comment was about x86, where the audit arch could change on the
> fly.  For ARM, the audit arch doesn't change---syscall_get_arch()
> always returns AUDIT_ARCH_ARM.

Hi,

Indeed, syscall_get_arch() will only return AUDIT_ARCH_ARM on ARM right now. 
This might be more future proof to call syscall_get_arch() though. The main 
reason that comes to my mind would be an AArch64 kernel with support for 
AArch32 userland tasks. This would I expect require a different AUDIT_ARCH 
constant to differenciate between AArch64 and AArch32 tasks.

Regards,

-- 
Nicolas Schichan
Freebox SAS