Re: [tip:core/signals] signals/sigaltstack, x86/signals: Unify the x86 sigaltstack check with other architectures

[Andy Lutomirski]

On Tue, May 3, 2016 at 12:49 AM, tip-bot for Stas Sergeev
<tipbot@xxxxxxxxx> wrote:
> Commit-ID:  0b4521e8cf1f582da3045ea460427ac2f741578f
> Gitweb:     http://git.kernel.org/tip/0b4521e8cf1f582da3045ea460427ac2f741578f
> Author:     Stas Sergeev <stsp@xxxxxxx>
> AuthorDate: Thu, 14 Apr 2016 23:20:02 +0300
> Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
> CommitDate: Tue, 3 May 2016 08:37:58 +0200
>
> signals/sigaltstack, x86/signals: Unify the x86 sigaltstack check with other architectures
>
> Currently x86's get_sigframe() checks for "current->sas_ss_size"
> to determine whether there is a need to switch to sigaltstack.
> The common practice used by all other arches is to check for
> sas_ss_flags(sp) == 0
>
> This patch makes the code consistent with other architectures.
>
> The slight complexity of the patch is added by the optimization on
> !sigstack check that was requested by Andy Lutomirski: sas_ss_flags(sp)==0
> already implies that we are not on a sigstack, so the code is shuffled
> to avoid the duplicate checking.
>
> This patch should have no user-visible impact.

I'm late to the party, but LGTM.

--Andy