Re: [PATCH 1/8] kasan,x86: Frob kasan_report() in an exception

From: Linus Torvalds
Date: Wed Mar 06 2019 - 12:59:33 EST

On Wed, Mar 6, 2019 at 9:37 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> The below seems to 'work'.

Yeah, and makes things cheaper for the non-SMAP case too. Looks sane.

One note:

+ asm volatile (ALTERNATIVE("", "pushf; pop %0; "

Hmm. Every single use of __ASM_CLAC is together with "__stringity()".

Maybe we could just get rid of that oddity, and just make __ASM_CLAC
be a string to begin with.

At one point it was used bare in the __ASSEMBLY__ version, but that
does not appear to the case any more since commit 669f8a900198
("x86/smap: Use ALTERNATIVE macro") back in 2015.