On Mon, Jan 16, 2017 at 08:36:00AM +1100, Anton Blanchard wrote:
> Hi,
>
> I was debugging a hang on a ppc64le kernel built with clang, and it
> looks to be undefined behaviour with pointer wrapping in the llist code.
>
> A test case is below. llist_for_each_entry() does container_of() on a
> NUL
Hi Peter,
> Last I checked I couldn't build a x86_64 kernel with llvm. So no, not
> something I've ever ran into.
>
> Also, I would argue that this is broken in llvm, the kernel very much
> relies on things like this all over the place. Sure, we're way outside
> of what the C language spec says,
On Mon, Jan 16, 2017 at 10:42:29PM +1100, Anton Blanchard wrote:
> Hi Peter,
>
> > Last I checked I couldn't build a x86_64 kernel with llvm. So no, not
> > something I've ever ran into.
> >
> > Also, I would argue that this is broken in llvm, the kernel very much
> > relies on things like this a
2017-01-16 15:53 GMT+03:00 Peter Zijlstra :
> On Mon, Jan 16, 2017 at 10:42:29PM +1100, Anton Blanchard wrote:
>> Hi Peter,
>>
>> > Last I checked I couldn't build a x86_64 kernel with llvm. So no, not
>> > something I've ever ran into.
>> >
>> > Also, I would argue that this is broken in llvm, the
From: Anton Blanchard
> Sent: 15 January 2017 21:36
> I was debugging a hang on a ppc64le kernel built with clang, and it
> looks to be undefined behaviour with pointer wrapping in the llist code.
>
> A test case is below. llist_for_each_entry() does container_of() on a
> NULL pointer, which wraps
On Mon, Jan 16, 2017 at 02:34:43PM +, David Laight wrote:
> From: Anton Blanchard
> > Sent: 15 January 2017 21:36
> > I was debugging a hang on a ppc64le kernel built with clang, and it
> > looks to be undefined behaviour with pointer wrapping in the llist code.
> >
> > A test case is below. l