Re: [PATCH] arm64: kasan: clear stale stack poison

[Will Deacon]

On Thu, Feb 18, 2016 at 05:54:47PM +0000, Catalin Marinas wrote:
> On Thu, Feb 18, 2016 at 05:27:38PM +0000, Mark Rutland wrote:
> > @@ -145,6 +146,7 @@ ENTRY(cpu_resume_mmu)
> >  ENDPROC(cpu_resume_mmu)
> >  	.popsection
> >  cpu_resume_after_mmu:
> > +	kasan_unpoison_stack 96
> 
> I don't think the 96 here is needed since we populate the stack in
> assembly (__cpu_suspend_enter) and unwind it again still in assembly
> (cpu_resume_after_mmu), so no KASAN shadow writes/reads.
> 
> Otherwise the patch looks fine.

I'd much rather it was written in C -- is there a reason we can't do
that if we use a separate compilation unit where the compiler will
honour the fno-sanitize flag?

Will