* [PATCH V2] ARM: SWP emulation: Restore original *data when failed
@ 2015-10-15 9:30 Shengjiu Wang
2015-12-08 10:22 ` Vladimir Murzin
0 siblings, 1 reply; 4+ messages in thread
From: Shengjiu Wang @ 2015-10-15 9:30 UTC (permalink / raw)
To: linux, shengjiu.wang, ard.biesheuvel, nico; +Cc: linux-arm-kernel, linux-kernel
__user_swpX_asm maybe failed in first STREX operation, emulate_swpX
will try again, but the *data has been changed in first time. which
causes the result is wrong.
This patch is to fix this issue. When STREX succeed, change the *data.
if it fail, *data is not changed.
Signed-off-by: Shengjiu Wang <shengjiu.wang@freescale.com>
---
arch/arm/kernel/swp_emulate.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm/kernel/swp_emulate.c b/arch/arm/kernel/swp_emulate.c
index 5b26e7e..c3fe769d 100644
--- a/arch/arm/kernel/swp_emulate.c
+++ b/arch/arm/kernel/swp_emulate.c
@@ -36,10 +36,10 @@
*/
#define __user_swpX_asm(data, addr, res, temp, B) \
__asm__ __volatile__( \
- " mov %2, %1\n" \
- "0: ldrex"B" %1, [%3]\n" \
- "1: strex"B" %0, %2, [%3]\n" \
+ "0: ldrex"B" %2, [%3]\n" \
+ "1: strex"B" %0, %1, [%3]\n" \
" cmp %0, #0\n" \
+ " moveq %1, %2\n" \
" movne %0, %4\n" \
"2:\n" \
" .section .text.fixup,\"ax\"\n" \
--
1.9.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH V2] ARM: SWP emulation: Restore original *data when failed
2015-10-15 9:30 [PATCH V2] ARM: SWP emulation: Restore original *data when failed Shengjiu Wang
@ 2015-12-08 10:22 ` Vladimir Murzin
2015-12-08 10:44 ` Russell King - ARM Linux
0 siblings, 1 reply; 4+ messages in thread
From: Vladimir Murzin @ 2015-12-08 10:22 UTC (permalink / raw)
To: Shengjiu Wang, linux@arm.linux.org.uk, ard.biesheuvel@linaro.org,
nico@linaro.org
Cc: linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
On 15/10/15 10:30, Shengjiu Wang wrote:
> __user_swpX_asm maybe failed in first STREX operation, emulate_swpX
> will try again, but the *data has been changed in first time. which
> causes the result is wrong.
> This patch is to fix this issue. When STREX succeed, change the *data.
> if it fail, *data is not changed.
>
> Signed-off-by: Shengjiu Wang <shengjiu.wang@freescale.com>
> ---
> arch/arm/kernel/swp_emulate.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm/kernel/swp_emulate.c b/arch/arm/kernel/swp_emulate.c
> index 5b26e7e..c3fe769d 100644
> --- a/arch/arm/kernel/swp_emulate.c
> +++ b/arch/arm/kernel/swp_emulate.c
> @@ -36,10 +36,10 @@
> */
> #define __user_swpX_asm(data, addr, res, temp, B) \
> __asm__ __volatile__( \
> - " mov %2, %1\n" \
> - "0: ldrex"B" %1, [%3]\n" \
> - "1: strex"B" %0, %2, [%3]\n" \
> + "0: ldrex"B" %2, [%3]\n" \
> + "1: strex"B" %0, %1, [%3]\n" \
> " cmp %0, #0\n" \
> + " moveq %1, %2\n" \
> " movne %0, %4\n" \
> "2:\n" \
> " .section .text.fixup,\"ax\"\n" \
>
I wonder what is status of this patch? I see that arm64 counterpart has
landed in mainline, but I didn't manage to track down this one - is it
because it never been submitted to patch system?
Thanks
Vladimir
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH V2] ARM: SWP emulation: Restore original *data when failed
2015-12-08 10:22 ` Vladimir Murzin
@ 2015-12-08 10:44 ` Russell King - ARM Linux
2015-12-08 12:41 ` Vladimir Murzin
0 siblings, 1 reply; 4+ messages in thread
From: Russell King - ARM Linux @ 2015-12-08 10:44 UTC (permalink / raw)
To: Vladimir Murzin
Cc: Shengjiu Wang, ard.biesheuvel@linaro.org, nico@linaro.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
On Tue, Dec 08, 2015 at 10:22:53AM +0000, Vladimir Murzin wrote:
> On 15/10/15 10:30, Shengjiu Wang wrote:
> > __user_swpX_asm maybe failed in first STREX operation, emulate_swpX
> > will try again, but the *data has been changed in first time. which
> > causes the result is wrong.
> > This patch is to fix this issue. When STREX succeed, change the *data.
> > if it fail, *data is not changed.
> >
> > Signed-off-by: Shengjiu Wang <shengjiu.wang@freescale.com>
> > ---
> > arch/arm/kernel/swp_emulate.c | 6 +++---
> > 1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/arch/arm/kernel/swp_emulate.c b/arch/arm/kernel/swp_emulate.c
> > index 5b26e7e..c3fe769d 100644
> > --- a/arch/arm/kernel/swp_emulate.c
> > +++ b/arch/arm/kernel/swp_emulate.c
> > @@ -36,10 +36,10 @@
> > */
> > #define __user_swpX_asm(data, addr, res, temp, B) \
> > __asm__ __volatile__( \
> > - " mov %2, %1\n" \
> > - "0: ldrex"B" %1, [%3]\n" \
> > - "1: strex"B" %0, %2, [%3]\n" \
> > + "0: ldrex"B" %2, [%3]\n" \
> > + "1: strex"B" %0, %1, [%3]\n" \
> > " cmp %0, #0\n" \
> > + " moveq %1, %2\n" \
> > " movne %0, %4\n" \
> > "2:\n" \
> > " .section .text.fixup,\"ax\"\n" \
> >
>
> I wonder what is status of this patch? I see that arm64 counterpart has
> landed in mainline, but I didn't manage to track down this one - is it
> because it never been submitted to patch system?
Most probably.
--
RMK's Patch system: http://www.arm.linux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH V2] ARM: SWP emulation: Restore original *data when failed
2015-12-08 10:44 ` Russell King - ARM Linux
@ 2015-12-08 12:41 ` Vladimir Murzin
0 siblings, 0 replies; 4+ messages in thread
From: Vladimir Murzin @ 2015-12-08 12:41 UTC (permalink / raw)
To: Russell King - ARM Linux
Cc: Shengjiu Wang, ard.biesheuvel@linaro.org, nico@linaro.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
On 08/12/15 10:44, Russell King - ARM Linux wrote:
> On Tue, Dec 08, 2015 at 10:22:53AM +0000, Vladimir Murzin wrote:
>> On 15/10/15 10:30, Shengjiu Wang wrote:
>>> __user_swpX_asm maybe failed in first STREX operation, emulate_swpX
>>> will try again, but the *data has been changed in first time. which
>>> causes the result is wrong.
>>> This patch is to fix this issue. When STREX succeed, change the *data.
>>> if it fail, *data is not changed.
>>>
>>> Signed-off-by: Shengjiu Wang <shengjiu.wang@freescale.com>
>>> ---
>>> arch/arm/kernel/swp_emulate.c | 6 +++---
>>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/arch/arm/kernel/swp_emulate.c b/arch/arm/kernel/swp_emulate.c
>>> index 5b26e7e..c3fe769d 100644
>>> --- a/arch/arm/kernel/swp_emulate.c
>>> +++ b/arch/arm/kernel/swp_emulate.c
>>> @@ -36,10 +36,10 @@
>>> */
>>> #define __user_swpX_asm(data, addr, res, temp, B) \
>>> __asm__ __volatile__( \
>>> - " mov %2, %1\n" \
>>> - "0: ldrex"B" %1, [%3]\n" \
>>> - "1: strex"B" %0, %2, [%3]\n" \
>>> + "0: ldrex"B" %2, [%3]\n" \
>>> + "1: strex"B" %0, %1, [%3]\n" \
>>> " cmp %0, #0\n" \
>>> + " moveq %1, %2\n" \
>>> " movne %0, %4\n" \
>>> "2:\n" \
>>> " .section .text.fixup,\"ax\"\n" \
>>>
>>
>> I wonder what is status of this patch? I see that arm64 counterpart has
>> landed in mainline, but I didn't manage to track down this one - is it
>> because it never been submitted to patch system?
>
> Most probably.
>
I've just submitted (on behalf of Shengjiu) it as 8475/1 with assumption
you have no concerns about the patch.
Thanks
Vladimir
^ permalink raw reply [flat|nested] 4+ messages in thread
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2015-10-15 9:30 [PATCH V2] ARM: SWP emulation: Restore original *data when failed Shengjiu Wang
2015-12-08 10:22 ` Vladimir Murzin
2015-12-08 10:44 ` Russell King - ARM Linux
2015-12-08 12:41 ` Vladimir Murzin
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