* [PATCH] sh: cmpxchg: fix a bit shift bug in big_endian os
@ 2016-04-19 6:58 Pan Xinhui
2016-04-19 10:00 ` Michael S. Tsirkin
2016-04-20 6:41 ` [PATCH V2]sh: " Pan Xinhui
0 siblings, 2 replies; 5+ messages in thread
From: Pan Xinhui @ 2016-04-19 6:58 UTC (permalink / raw)
To: linux-kernel; +Cc: ysato, dalias, mst, peterz, linux-sh
From: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Correct bitoff in big endian OS.
Fixes: 3226aad81aa6 ("sh: support 1 and 2 byte xchg")
Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
---
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
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] sh: cmpxchg: fix a bit shift bug in big_endian os
2016-04-19 6:58 [PATCH] sh: cmpxchg: fix a bit shift bug in big_endian os Pan Xinhui
@ 2016-04-19 10:00 ` Michael S. Tsirkin
2016-04-20 6:41 ` [PATCH V2]sh: " Pan Xinhui
1 sibling, 0 replies; 5+ messages in thread
From: Michael S. Tsirkin @ 2016-04-19 10:00 UTC (permalink / raw)
To: Pan Xinhui; +Cc: linux-kernel, ysato, dalias, peterz, linux-sh
On Tue, Apr 19, 2016 at 02:58:53PM +0800, Pan Xinhui wrote:
> From: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
>
> Correct bitoff in big endian OS.
>
> Fixes: 3226aad81aa6 ("sh: support 1 and 2 byte xchg")
> Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
I would add: current code works correctly for 1 byte but not for 2 bytes.
Acked-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> 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
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH V2]sh: cmpxchg: fix a bit shift bug in big_endian os
2016-04-19 6:58 [PATCH] sh: cmpxchg: fix a bit shift bug in big_endian os Pan Xinhui
2016-04-19 10:00 ` Michael S. Tsirkin
@ 2016-04-20 6:41 ` Pan Xinhui
2016-04-26 1:39 ` Rich Felker
1 sibling, 1 reply; 5+ messages in thread
From: Pan Xinhui @ 2016-04-20 6:41 UTC (permalink / raw)
To: linux-kernel; +Cc: ysato, dalias, mst, peterz, linux-sh
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.
---
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
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH V2]sh: cmpxchg: fix a bit shift bug in big_endian os
2016-04-20 6:41 ` [PATCH V2]sh: " Pan Xinhui
@ 2016-04-26 1:39 ` Rich Felker
2016-04-26 10:07 ` Pan Xinhui
0 siblings, 1 reply; 5+ messages in thread
From: Rich Felker @ 2016-04-26 1:39 UTC (permalink / raw)
To: Pan Xinhui; +Cc: linux-kernel, ysato, mst, peterz, linux-sh
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.
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
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH V2]sh: cmpxchg: fix a bit shift bug in big_endian os
2016-04-26 1:39 ` Rich Felker
@ 2016-04-26 10:07 ` Pan Xinhui
0 siblings, 0 replies; 5+ messages in thread
From: Pan Xinhui @ 2016-04-26 10:07 UTC (permalink / raw)
To: Rich Felker; +Cc: linux-kernel, ysato, mst, peterz, linux-sh
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
>
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2016-04-26 10:07 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-04-19 6:58 [PATCH] sh: cmpxchg: fix a bit shift bug in big_endian os Pan Xinhui
2016-04-19 10:00 ` Michael S. Tsirkin
2016-04-20 6:41 ` [PATCH V2]sh: " Pan Xinhui
2016-04-26 1:39 ` Rich Felker
2016-04-26 10:07 ` Pan Xinhui
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).