Re: [PATCH 1/4] signals/sigaltstack: If SS_AUTODISARM, bypass on_sig_stack

From: Ingo Molnar
Date: Wed May 04 2016 - 02:32:44 EST

* Andy Lutomirski <luto@xxxxxxxxxx> wrote:

> If a signal stack is set up with SS_AUTODISARM, then the kernel
> inherently avoids incorrectly resetting the signal stack if signals
> recurse: the signal stack will be reset on the first signal
> delivery. This means that we don't need check the stack pointer
> when delivering signals if SS_AUTODISARM is set.
> This will make segmented x86 programs more robust: currently there's
> a hole that could be triggered if ESP/RSP appears to point to the
> signal stack but actually doesn't due to a nonzero SS base.
> Signed-off-by: Stas Sergeev <stsp@xxxxxxx>

Presuably that SOB from Stas is stray, as there's no matching From: line?
I've removed it.