Re: [lkp-robot] [x86/kconfig] 81d3871900: BUG:unable_to_handle_kernel

[Jeffrey Walton]

On Fri, Oct 13, 2017 at 3:09 PM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Fri, Oct 13, 2017 at 6:56 AM, Andrey Ryabinin
> <aryabinin@xxxxxxxxxxxxx> wrote:
>>
>> This could be fixed by s/vmovdqa/vmovdqu change like bellow, but maybe the right fix
>> would be to align the data properly?
>
> I suspect anything that has the SHA extensions should also do
> unaligned loads efficiently. The whole "aligned only" model is broken.
> It's just doing two loads from the state pointer, there's likely no
> point in trying to align it.

+1, good engineering.

AVX2 requires 32-byte buffer alignment in some places. It is trickier
than this use case because __BIGGEST_ALIGNMENT__ doubled, but a lot of
code still assumes 16-bytes.

Jeff