On 2016年04月26日 09:39, Rich Felker wrote:
> On Wed, Apr 20, 2016 at 02:41:00PM +0800, Pan Xinhui wrote:
>> From: Pan Xinhui <xinhui....@linux.vnet.ibm.com>
>>
>> Correct bitoff in big endian OS.
>> Current code works correctly for 1 byte but not for 2 bytes.
>>
>> Fixes: 3226aad81aa6 ("sh: support 1 and 2 byte xchg")
>> Signed-off-by: Pan Xinhui <xinhui....@linux.vnet.ibm.com>
>> Acked-by: Michael S. Tsirkin <m...@redhat.com>
>> ---
>> changes from V1:
>> just add some patch comments. no code changes.
>
> Looks good. Are you aware of any code affected by this bug that would
> make it a regression in 4.6? If so I'll try to get this in now as a
> bugfix; otherwise I'll include it in stuff for 4.7.
>
no idea about what code is affected.
4.7 is okay I think. :)
xinhui
> Rich
>
>
>> ---
>> arch/sh/include/asm/cmpxchg-xchg.h | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/sh/include/asm/cmpxchg-xchg.h
>> b/arch/sh/include/asm/cmpxchg-xchg.h
>> index 7219719..1e881f5 100644
>> --- a/arch/sh/include/asm/cmpxchg-xchg.h
>> +++ b/arch/sh/include/asm/cmpxchg-xchg.h
>> @@ -21,7 +21,7 @@ static inline u32 __xchg_cmpxchg(volatile void *ptr, u32
>> x, int size)
>> int off = (unsigned long)ptr % sizeof(u32);
>> volatile u32 *p = ptr - off;
>> #ifdef __BIG_ENDIAN
>> - int bitoff = (sizeof(u32) - 1 - off) * BITS_PER_BYTE;
>> + int bitoff = (sizeof(u32) - size - off) * BITS_PER_BYTE;
>> #else
>> int bitoff = off * BITS_PER_BYTE;
>> #endif
>> --
>> 1.9.1
>
