Re: DIE_GPF vs. DIE_PAGE_FAULT/DIE_TRAP

[Andi Kleen]

On Wednesday 26 October 2005 17:21, Jan Beulich wrote:
 
> Hmm, then this isn't really useful for a debugger. There ought to be a
> chance to filter exceptions early (i.e. debugger accesses to non-mapped
> memory or non-existing MSRs) and a chance to detect bad faults (note
> that the kernel normal exception recovery mechanism may not be usable
> here because for example page faults first try to service the fault
> before scanning the fixup tables, but a debugger will normally not want
> a page-in to happen behind its back). I thought the latter was what gets
> reported as DIE_OOPS, while the former would be the filtering occasions
> (and I actually took the "grossly misnamed" comment in asm/kdebug.h as
> additional indication for that).

All you want is a hook early in GPF, right? I guess that should be ok.
I can see that it's useful on x86-64 due to the non canonical address 
fault resulting in GPFs mess. 

Just send a patch.

-Andi
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