Re: [PATCH v2] powerpc/32: fix csum_partial_copy_generic()

From: Michael Ellerman
Date: Fri Aug 05 2016 - 02:58:06 EST


Alessio Igor Bogani <alessio.bogani@xxxxxxxxxx> writes:
> On 4 August 2016 at 05:53, Scott Wood <oss@xxxxxxxxxxxx> wrote:
>> On Tue, 2016-08-02 at 10:07 +0200, Christophe Leroy wrote:
>>> commit 7aef4136566b0 ("powerpc32: rewrite csum_partial_copy_generic()
>>> based on copy_tofrom_user()") introduced a bug when destination
>>> address is odd and initial csum is not null
>>>
>>> In that (rare) case the initial csum value has to be rotated one byte
>>> as well as the resulting value is
>>>
>>> This patch also fixes related comments
>>>
>>> Fixes: 7aef4136566b0 ("powerpc32: rewrite csum_partial_copy_generic()
>>> based on copy_tofrom_user()")
>>> Cc: stable@xxxxxxxxxxxxxxx
>>>
>>> Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
>>> ---
>>> v2: updated comments as suggested by Segher
>>>
>>> arch/powerpc/lib/checksum_32.S | 7 ++++---
>>> 1 file changed, 4 insertions(+), 3 deletions(-)
>>
>> Alessio, can you confirm whether this fixes the problem you reported?
>
> No unfortunately.

Thanks for testing.

I've dropped the patch for now, send me a new one that works.

cheers