Messages in this thread | | | Date | Thu, 01 Nov 2012 19:53:00 +0000 | From | "Jan Beulich" <> | Subject | Re: [PATCH] [PATCH] x86: Don't clobber top of pt_regs in nested NMI |
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>>> 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.
Jan
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