Re: [git pull] x86 fixes

Linus Torvalds
2008-07-24T19:40:01Z

On Thu, 24 Jul 2008, Ingo Molnar wrote:
>
> Hugh Dickins (1):
> x86: BUILD_IRQ say .text to avoid .data.percpu
>
> diff --git a/arch/x86/kernel/irqinit_64.c b/arch/x86/kernel/irqinit_64.c
> index 0373e88..9414125 100644
> --- a/arch/x86/kernel/irqinit_64.c
> +++ b/arch/x86/kernel/irqinit_64.c
> @@ -43,7 +43,7 @@
>
> #define BUILD_IRQ(nr) \
> asmlinkage void IRQ_NAME(nr); \
> - asm("\n.p2align\n" \
> + asm("\n.text\n.p2align\n" \
> "IRQ" #nr "_interrupt:\n\t" \
> "push $~(" #nr ") ; " \
> "jmp common_interrupt");

I do not think this is a good idea AT ALL.

You need a ".previous" there too, otherwise any random C code that doesn't
_happen_ to change segments will now possibly put some random variable in
the .text segment.

And yes, dependign on just where the BUILD_IRQ() is, and what is around
it, and what compiler version we have, this bug may or may not show. But
it's still _wrong_.

I pulled it, will fix up by hand.

Linus