On 24/11/11 02:23, Richard Henderson wrote:
> On 11/23/2011 04:00 PM, Joseph S. Myers wrote:
>> On Wed, 23 Nov 2011, Richard Henderson wrote:
>>
>>> + __asm volatile ("swi %1"
>>> + : "+r"(sc_0)
>>> + : "i"(SYS_futex), "r"(sc_1), "r"(sc_2), "r"(sc_3)
>>> + : "memory");
>>
>> That looks wrong. Passing the syscall number to swi is the old-ABI
>> approach; the EABI uses syscall number in r7.
>
Which gets even more interesting in Thumb because r7 is what GCC thinks
is the frame pointer register :-(
> Interesting to know.
>
> I took as examples both glibc ports sysdeps.h and CLEAR_INSN_CACHE from
> linux-gas.h. Which... I see is out of date wrt libgcc lib1funcs.S
> clear_cache.
>
> Perhaps I'm better off with the syscall function as libgomp uses?
That's probably the best solution on ARM.
R.
