Messages in this thread | | | Date | Fri, 2 Dec 2016 22:09:03 +0100 | From | Pavel Machek <> | Subject | Re: [PATCH v4] x86/suspend: fix false positive KASAN warning on suspend/resume |
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On Fri 2016-12-02 11:42:21, Josh Poimboeuf wrote: > Resuming from a suspend operation is showing a KASAN false positive > warning: > > > Reported-by: Scott Bauer <scott.bauer@intel.com> > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
> diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c > index 0e9505f..b2a0cff 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 & ~(THREAD_SIZE - 1)); > + > + kasan_unpoison_shadow(base, watermark - base); > } >
I know you modified this code to be arch-independend... but is it really? I guess it is portable enough across architectures that run kasan today.. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html [unhandled content-type:application/pgp-signature] | |