[lkml]   [2000]   [Dec]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: Why is double_fault serviced by a trap gate?
On Thu, 7 Dec 2000, Richard B. Johnson wrote:

> I am not denying the possibility of "warm-booting", i.e.,
> reloate some code to where there is a 1:1 physical to virtual
> translation, jump to the relocated code, disable paging, restart kernel
> code, and possibly examine what happened. You just have to get
> back to "flat-mode" with no paging to handle anything beyond a
> double fault. You are just not going to be able to restart
> from the stack-faulted code.

If you want to handle triple faults (well, there should be none of these
given a proper double fault handler) you may use the NMI as well. You are
guaranteed to receive a NMI after a while when the watchdog is active (it
is for SMP systems by default now and it will be for P6+ UP systems for
Linux 2.5 as well). At least current Intel chipsets do not assert RESET
to the CPU as a response to the shutdown special cycle in their default
configuration (we may even explicitly force that behaviour).

+ Maciej W. Rozycki, Technical University of Gdansk, Poland +
+ e-mail:, PGP key available +

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
Please read the FAQ at

 \ /
  Last update: 2005-03-22 12:51    [W:0.035 / U:7.812 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site