Messages in this thread | | | Date | Tue, 26 Apr 2016 18:07:37 +0800 | From | Pan Xinhui <> | Subject | Re: [PATCH V2]sh: cmpxchg: fix a bit shift bug in big_endian os |
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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.pan@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.pan@linux.vnet.ibm.com> >> Acked-by: Michael S. Tsirkin <mst@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 >
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