Messages in this thread Patch in this message | | | Subject | Re: [PATCH] [PATCH] x86: Don't clobber top of pt_regs in nested NMI | From | Steven Rostedt <> | Date | Thu, 01 Nov 2012 16:37:21 -0400 |
| |
On Thu, 2012-11-01 at 19:53 +0000, Jan Beulich wrote: > >>> Steven Rostedt <rostedt@goodmis.org> 11/01/12 2:04 AM >>> > >On Mon, 2012-10-01 at 17:29 -0700, Salman Qazi wrote: > >> @@ -1826,12 +1832,15 @@ repeat_nmi: > >> * is benign for the non-repeat case, where 1 was pushed just above > >> * to this very stack slot). > >> */ > >> - movq $1, 5*8(%rsp) > >> + movq $1, 10*8(%rsp) > >> > >> /* Make another copy, this one may be modified by nested NMIs */ > >> + addq $(10*8), %rsp > > > >This breaks the CFI magic. > > > >> .rept 5 > >> - pushq_cfi 4*8(%rsp) > >> + pushq_cfi -6*8(%rsp) > >> .endr > >> + subq $(5*8), %rsp > > > >So does this. > > > >This needs to be annotated correctly before I can push it out. But the > >good news is, I stressed tested this change, and it all works out. > > > >Jan, can you help out here? > > There doesn't appear to be anything special about these adjustments, so I > don't see what help would be required here - it ought to be the normal use > of CFI_ADJUST_CFA_OFFSET that needs adding.
Even the simple CFI adjustments look like magic to me :-) OK, I'll update the patch and send it out. I'll Cc you in case I screw up even the most simple case ;-)
-- Steve
| |