GCC-4 problems

[Manuel L. <ma...@ro...>]

Hello,

When I build linux with GCC-4.x and enable CONFIG_CC_OPTIMIZE_FOR_SIZE
linking fails with this error:

  LD      .tmp_vmlinux1
kernel/built-in.o: In function '__cmpxchg_called_with_bad_pointer'
make[1]: *** [.tmp_vmlinux1] Error 1
make: *** [_all] Error 2

I tracked it to kernel/rtmutex.c, line 88:

#define rt_mutex_cmpxchg(l,c,n)	(cmpxchg(&l->owner, c, n) == c)

Apparently the "size" input value passed to cmpxchg is 
neither 4, 2 or 1 (tried a few others too but not sizeof(struct task_struct)).
Probably a compiler bug? (gcc-4.1.2, Gentoo)

Also, these exports need to be removed from sh_ksyms.c, they give
"undefined reference" errors:
__sdivsi3_i4i __udiv_qrnnd_16 __udivsi3_i4i

Kernel boots ok otherwise.

Thanks,

-- 
 Manuel Lauss