Re: [PATCH] [PATCH] x86: Don't clobber top of pt_regs in nested NMI

From: Steven Rostedt
Date: Fri Nov 02 2012 - 09:51:56 EST


On Thu, 2012-11-01 at 19:53 +0000, Jan Beulich wrote:

> 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.

This change look fine to you?

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 52edf92..7ba5342 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1796,10 +1796,12 @@ repeat_nmi:

/* Make another copy, this one may be modified by nested NMIs */
addq $(10*8), %rsp
+ CFI_ADJUST_CFA_OFFSET -10*8
.rept 5
pushq_cfi -6*8(%rsp)
.endr
subq $(5*8), %rsp
+ CFI_ADJUST_CFA_OFFSET 5*8

CFI_DEF_CFA_OFFSET SS+8-RIP
end_repeat_nmi:


-- Steve


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