Re: 2.6.24-rc6-mm1
From: Christoph Hellwig
Date: Sun Dec 23 2007 - 07:12:30 EST
On Sun, Dec 23, 2007 at 12:57:35PM +0100, Ingo Molnar wrote:
>
> * Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> > Still. The crash is 100% repeatable and is the same every time.
> > Happens on both my i386 test boxes.
> >
> > http://userweb.kernel.org/~akpm/config-sony.txt
> > http://userweb.kernel.org/~akpm/config-vmm.txt
> >
> > and I bisected it down to e3c1b141.
>
> ok, can reproduce it - the patch below fixes it for me.
>
> Ingo
>
> ------------------------->
> Subject: x86: fix system gate related crash
> From: Ingo Molnar <mingo@xxxxxxx>
>
> on 32-bit, system gates are traps.
>
> on 64-bit, they are interrupts (which disable hardirqs).
>
> Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
> ---
> include/asm-x86/desc.h | 4 ++++
> 1 file changed, 4 insertions(+)
>
> Index: linux-x86.q/include/asm-x86/desc.h
> ===================================================================
> --- linux-x86.q.orig/include/asm-x86/desc.h
> +++ linux-x86.q/include/asm-x86/desc.h
> @@ -310,7 +310,11 @@ static inline void set_trap_gate(unsigne
> static inline void set_system_gate(unsigned int n, void *addr)
> {
> BUG_ON((unsigned)n > 0xFF);
> +#ifdef CONFIG_X86_32
> + _set_gate(n, GATE_TRAP, addr, 0x3, 0, __KERNEL_CS);
> +#else
> _set_gate(n, GATE_INTERRUPT, addr, 0x3, 0, __KERNEL_CS);
> +#endif
> }
>
This would be a lot cleaner with entirely separate implementations
of set_system_gate for 32 vs 64 bit. Especially if the file already
has a large ifdef block for 32 vs 64 already.
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