Re: [RFC][PATCH 5/5] arch: Sanitize atomic_t bitwise ops

From: Geert Uytterhoeven
Date: Thu Feb 06 2014 - 09:43:27 EST


On Thu, Feb 6, 2014 at 2:48 PM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> --- a/arch/m68k/include/asm/atomic.h
> +++ b/arch/m68k/include/asm/atomic.h
> @@ -76,6 +76,9 @@ static inline int atomic_##op##_return(i
>
> ATOMIC_OP(add, +=)
> ATOMIC_OP(sub, -=)
> +ATOMIC_OP(and, &=)
> +ATOMIC_OP(or , |=)
> +ATOMIC_OP(xor, ^=)

This last one ain't gonna fly. Given

static inline void atomic_##op(int i, atomic_t *v) \
{ \
__asm__ __volatile__(#op "l %1,%0" : "+m" (*v) : ASM_DI (i)); \
}

from the previous patch, it'll generate the "xorl" mnemonic, which
IIRC does not exist. It's called "eorl".

Verified with m68k-linux-gnu-as:

Error: Unknown operator -- statement `xorl %d0,%d1' ignored

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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