On Wed, 23 Nov 2011, 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.
>
> Interesting to know.
>
> I took as examples both glibc ports sysdeps.h
Overridden in the eabi/ subdirectory. Yes, as ARM glibc maintainer it's
probably time for me to kill the old-ABI support and simplify the
directory structure....
> and CLEAR_INSN_CACHE from linux-gas.h. Which... I see is out of date
> wrt libgcc lib1funcs.S clear_cache.
Again, an old-ABI-only version; I moved the EABI version to lib1funcs.S
from linux-eabi.h to avoid a problem where building libgcc for Thumb-2
with -O0 quietly produced broken code because of the conflict with the
frame pointer <http://gcc.gnu.org/ml/gcc-patches/2009-05/msg01320.html>.
Dan ended up moving Thumb-2 syscalls out-of-line in glibc for much the
same reason (unwinding being the problem there)
<http://sourceware.org/ml/libc-ports/2010-04/msg00001.html>.
> Perhaps I'm better off with the syscall function as libgomp uses?
That's certainly safer and avoids depending on EABI/old-ABI.
--
Joseph S. Myers
jos...@codesourcery.com
