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Groups > linux.kernel > #1382216 > unrolled thread
| Started by | Pan Xinhui <xinhui@linux.vnet.ibm.com> |
|---|---|
| First post | 2016-04-19 09:10 +0200 |
| Last post | 2016-04-26 12:10 +0200 |
| Articles | 5 — 3 participants |
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[PATCH] sh: cmpxchg: fix a bit shift bug in big_endian os Pan Xinhui <xinhui@linux.vnet.ibm.com> - 2016-04-19 09:10 +0200
Re: [PATCH] sh: cmpxchg: fix a bit shift bug in big_endian os "Michael S. Tsirkin" <mst@redhat.com> - 2016-04-19 12:10 +0200
[PATCH V2]sh: cmpxchg: fix a bit shift bug in big_endian os Pan Xinhui <xinhui@linux.vnet.ibm.com> - 2016-04-20 08:50 +0200
Re: [PATCH V2]sh: cmpxchg: fix a bit shift bug in big_endian os Rich Felker <dalias@libc.org> - 2016-04-26 03:40 +0200
Re: [PATCH V2]sh: cmpxchg: fix a bit shift bug in big_endian os Pan Xinhui <xinhui@linux.vnet.ibm.com> - 2016-04-26 12:10 +0200
| From | Pan Xinhui <xinhui@linux.vnet.ibm.com> |
|---|---|
| Date | 2016-04-19 09:10 +0200 |
| Subject | [PATCH] sh: cmpxchg: fix a bit shift bug in big_endian os |
| Message-ID | <rpxXj-2U7-11@gated-at.bofh.it> |
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
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| From | "Michael S. Tsirkin" <mst@redhat.com> |
|---|---|
| Date | 2016-04-19 12:10 +0200 |
| Message-ID | <rpALv-59q-3@gated-at.bofh.it> |
| In reply to | #1382216 |
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
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| From | Pan Xinhui <xinhui@linux.vnet.ibm.com> |
|---|---|
| Date | 2016-04-20 08:50 +0200 |
| Subject | [PATCH V2]sh: cmpxchg: fix a bit shift bug in big_endian os |
| Message-ID | <rpU7w-3rG-15@gated-at.bofh.it> |
| In reply to | #1382216 |
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
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| From | Rich Felker <dalias@libc.org> |
|---|---|
| Date | 2016-04-26 03:40 +0200 |
| Subject | Re: [PATCH V2]sh: cmpxchg: fix a bit shift bug in big_endian os |
| Message-ID | <rs08N-7su-11@gated-at.bofh.it> |
| In reply to | #1383081 |
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
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| From | Pan Xinhui <xinhui@linux.vnet.ibm.com> |
|---|---|
| Date | 2016-04-26 12:10 +0200 |
| Subject | Re: [PATCH V2]sh: cmpxchg: fix a bit shift bug in big_endian os |
| Message-ID | <rs86n-5NZ-37@gated-at.bofh.it> |
| In reply to | #1387065 |
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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