diff mbox

ARM: Fix clone build for ARMv4

Message ID 1390477771-30826-1-git-send-email-will.newton@linaro.org
State Accepted
Headers show

Commit Message

Will Newton Jan. 23, 2014, 11:49 a.m. UTC
ARMv4 does not have the blx instruction, so use the BLX macro which
handles abstracting this for us.

ports/ChangeLog.arm:

2014-01-23  Will Newton  <will.newton@linaro.org>

	[BZ #16499]
	* sysdeps/unix/sysv/linux/arm/clone.S: Use BLX macro instead
	of blx instruction directly.
---
 ports/sysdeps/unix/sysv/linux/arm/clone.S | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

Comments

Will Newton Jan. 23, 2014, 6:22 p.m. UTC | #1
On 23 January 2014 17:30, Carlos O'Donell <carlos@redhat.com> wrote:
> On 01/23/2014 06:49 AM, Will Newton wrote:
>> ARMv4 does not have the blx instruction, so use the BLX macro which
>> handles abstracting this for us.
>>
>> ports/ChangeLog.arm:
>>
>> 2014-01-23  Will Newton  <will.newton@linaro.org>
>>
>>       [BZ #16499]
>>       * sysdeps/unix/sysv/linux/arm/clone.S: Use BLX macro instead
>>       of blx instruction directly.
>> ---
>>  ports/sysdeps/unix/sysv/linux/arm/clone.S | 8 +-------
>>  1 file changed, 1 insertion(+), 7 deletions(-)
>>
>> diff --git a/ports/sysdeps/unix/sysv/linux/arm/clone.S b/ports/sysdeps/unix/sysv/linux/arm/clone.S
>> index 44286a5..03fe9ab 100644
>> --- a/ports/sysdeps/unix/sysv/linux/arm/clone.S
>> +++ b/ports/sysdeps/unix/sysv/linux/arm/clone.S
>> @@ -88,14 +88,8 @@ PSEUDO_END (__clone)
>>  #endif
>>       @ pick the function arg and call address off the stack and execute
>>       ldr     r0, [sp, #4]
>> -#if defined(__ARM_ARCH_4T__) && defined(__THUMB_INTERWORK__)
>>       ldr     ip, [sp], #8
>> -     mov     lr, pc
>> -     bx      ip
>> -#else
>> -     ldr     lr, [sp], #8
>> -     blx     lr
>> -#endif
>> +     BLX (ip)
>
> Looks good.
>
>>
>>       @ and we are done, passing the return value through r0
>>       b       PLTJMP(HIDDEN_JUMPTARGET(_exit))
>>
>
> Did you test this or ask the submitter to test it?
>
> If he says it works then OK to commit.

I have tested this on armv7, I don't have an armv4 capable toolchain
at the moment to test it for that arch.

I've added Mike to CC so he can take a look.

Thanks,
Will Newton Jan. 24, 2014, 1:17 p.m. UTC | #2
On 23 January 2014 18:22, Will Newton <will.newton@linaro.org> wrote:
> On 23 January 2014 17:30, Carlos O'Donell <carlos@redhat.com> wrote:
>> On 01/23/2014 06:49 AM, Will Newton wrote:
>>> ARMv4 does not have the blx instruction, so use the BLX macro which
>>> handles abstracting this for us.
>>>
>>> ports/ChangeLog.arm:
>>>
>>> 2014-01-23  Will Newton  <will.newton@linaro.org>
>>>
>>>       [BZ #16499]
>>>       * sysdeps/unix/sysv/linux/arm/clone.S: Use BLX macro instead
>>>       of blx instruction directly.
>>> ---
>>>  ports/sysdeps/unix/sysv/linux/arm/clone.S | 8 +-------
>>>  1 file changed, 1 insertion(+), 7 deletions(-)
>>>
>>> diff --git a/ports/sysdeps/unix/sysv/linux/arm/clone.S b/ports/sysdeps/unix/sysv/linux/arm/clone.S
>>> index 44286a5..03fe9ab 100644
>>> --- a/ports/sysdeps/unix/sysv/linux/arm/clone.S
>>> +++ b/ports/sysdeps/unix/sysv/linux/arm/clone.S
>>> @@ -88,14 +88,8 @@ PSEUDO_END (__clone)
>>>  #endif
>>>       @ pick the function arg and call address off the stack and execute
>>>       ldr     r0, [sp, #4]
>>> -#if defined(__ARM_ARCH_4T__) && defined(__THUMB_INTERWORK__)
>>>       ldr     ip, [sp], #8
>>> -     mov     lr, pc
>>> -     bx      ip
>>> -#else
>>> -     ldr     lr, [sp], #8
>>> -     blx     lr
>>> -#endif
>>> +     BLX (ip)
>>
>> Looks good.
>>
>>>
>>>       @ and we are done, passing the return value through r0
>>>       b       PLTJMP(HIDDEN_JUMPTARGET(_exit))
>>>
>>
>> Did you test this or ask the submitter to test it?
>>
>> If he says it works then OK to commit.
>
> I have tested this on armv7, I don't have an armv4 capable toolchain
> at the moment to test it for that arch.

I figured out the correct value of CFLAGS to get a build for armv4
(and armv4t) and the patch fixes the issue, so I have committed it.
diff mbox

Patch

diff --git a/ports/sysdeps/unix/sysv/linux/arm/clone.S b/ports/sysdeps/unix/sysv/linux/arm/clone.S
index 44286a5..03fe9ab 100644
--- a/ports/sysdeps/unix/sysv/linux/arm/clone.S
+++ b/ports/sysdeps/unix/sysv/linux/arm/clone.S
@@ -88,14 +88,8 @@  PSEUDO_END (__clone)
 #endif
 	@ pick the function arg and call address off the stack and execute
 	ldr	r0, [sp, #4]
-#if defined(__ARM_ARCH_4T__) && defined(__THUMB_INTERWORK__)
 	ldr 	ip, [sp], #8
-	mov	lr, pc
-	bx      ip
-#else
-	ldr 	lr, [sp], #8
-	blx	lr
-#endif
+	BLX (ip)
 
 	@ and we are done, passing the return value through r0
 	b	PLTJMP(HIDDEN_JUMPTARGET(_exit))