Re: [CHECKER] large stack variables (>=1K) in 2.4.4 and 2.4.4-ac8

David Welch (david.welch@st-edmund-hall.oxford.ac.uk)
Fri, 25 May 2001 08:11:07 +0100


On Fri, May 25, 2001 at 03:20:20PM +1000, Keith Owens wrote:
>
> >> On a side note, does anyone know if the kernel does checking if the
> >> stack overflowed at any time?
> >
> >You normally get a silent hang or worse a stack fault exception
> >(which linux/x86 without kdb cannot recover from) which gives you instant
> >reboot.
>
> You cannot recover from a kernel stack overflow even with kdb. The
> exception handler and kdb use the stack that just overflowed.
>
Why not use a task gate for the double fault handler points to a
per-processor TSS with a seperate stack. This would allow limited recovery
from a kernel stack overlay.
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