Re: Fix x86 32 bit FRAME_POINTER chasing code

[Ingo Molnar <mingo@elte.hu>]

* Arjan van de Ven <arjan@infradead.org> wrote:

> +++ linux-2.6.24-rc7/arch/x86/kernel/traps_32.c
> @@ -124,7 +124,8 @@ static inline unsigned long print_contex
>  		unsigned long addr;
>  
>  		addr = frame->return_address;
> -		ops->address(data, addr);
> +		if (__kernel_text_address(addr))
> +			ops->address(data, addr);
>  		/*
>  		 * break out of recursive entries (such as
>  		 * end_of_stack_stop_unwind_function). Also,
> @@ -132,6 +133,7 @@ static inline unsigned long print_contex
>  		 * move downwards!
>  		 */
>  		next = frame->next_frame;
> +		ebp = (unsigned long) next;
>  		if (next <= frame)

thanks, applied. Nice catch!

> This patch is simple; I don't know if it's .24 candidate; the bug is 
> pretty bad but not a recent regression, and there is obviously some 
> risk with touching this code.

it's a 2.6.24.1 candidate i believe. We trigger plenty of various 
crashes during x86.git maintenance and others hit various crashes in 
-mm, so by the time .1 is released we'll have it in .25 and can backport 
it. Most folks/distros will update to 2.6.24.1 very quickly so there's 
no risk of months loss of quality to kerneloops.org data either.

if there's more than 1-2 weeks to the v2.6.24 release we could merge it 
right now as well:

 Acked-by: Ingo Molnar <mingo@elte.hu>

because in a week we'll trigger plenty of crashes in -git based x86 
trees and will know about any regressions and will be able to reasonably 
trust it.

	Ingo