Subject: Re: [PATCH 2/3] powerpc: kdump: CPUs assume the context of the oopsing CPU

From: Michael Ellerman <[email-masked]>
Date: Tue, 11 May 2010 14:14:31 +1000

On Tue, 2010-05-11 at 12:25 +1000, Anton Blanchard wrote:
> We wrap the crash_shutdown_handles[] calls with longjmp/setjmp, so if any
> of them fault we can recover. The problem is we add a hook to the debugger
> fault handler hook which calls longjmp unconditionally.
> 
> This first part of kdump is run before we marshall the other CPUs, so there
> is a very good chance some CPU on the box is going to page fault. And when
> it does it hits the longjmp code and assumes the context of the oopsing CPU.
> The machine gets very confused when it has 10 CPUs all with the same stack,
> all thinking they have the same CPU id. I get even more confused trying
> to debug it.

Lol, guess that one didn't get tested that well :)

Fix looks good.

cheers