Messages in this thread | | | Date | Wed, 16 Apr 2008 15:06:05 +0200 | From | Ingo Molnar <> | Subject | Re: [RFC PATCH] x86 NMI-safe INT3 and Page Fault (v2) |
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* Mathieu Desnoyers <compudj@krystal.dyndns.org> wrote:
> Implements an alternative iret with popf and return so trap and > exception handlers can return to the NMI handler without issuing iret. > iret would cause NMIs to be reenabled prematurely. x86_32 uses popf > and far return. x86_64 has to copy the return instruction pointer to > the top of the previous stack, issue a popf, loads the previous esp > and issue a near return (ret).
thanks Mathieu, i've picked this up into x86.git for more testing.
note that this also fixes an oprofile regression: when oprofile is used to generate stack-backtraces, we can fault on address resolution from NMI context and currently we do an IRET - with your fixes it should work fine. Obscure case but still worth fixing.
Ingo
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