Re: [PATCH v3] x86/suspend: fix false positive KASAN warning on suspend/resume

Josh Poimboeuf
2016-12-02T15:09:07Z

On Fri, Dec 02, 2016 at 05:45:18PM +0300, Andrey Ryabinin wrote:
>
>
> On 12/02/2016 05:42 PM, Josh Poimboeuf wrote:
>
>
> > diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
> > index 0e9505f..e9d8ba0 100644
> > --- a/mm/kasan/kasan.c
> > +++ b/mm/kasan/kasan.c
> > @@ -80,7 +80,14 @@ void kasan_unpoison_task_stack(struct task_struct *task)
> > /* Unpoison the stack for the current task beyond a watermark sp value. */
> > asmlinkage void kasan_unpoison_task_stack_below(const void *watermark)
> > {
> > - __kasan_unpoison_stack(current, watermark);
> > + /*
> > + * Calculate the task stack base address. Avoid using 'current'
> > + * because this function is called by early resume code which hasn't
> > + * yet set up the percpu register (%gs).
> > + */
> > + void *base = (void *)((unsigned long)watermark & CURRENT_MASK);
>
> CURRENT_MASK is defined only on x86...

Oops. I guess I should have taken your suggested patch verbatim...

Will do a proper multi-arch compile before submitting v4.

--
Josh