[PATCH] x86_64: Disallow kprobes on NMI handlers

A kprobe executes IRET early and that could cause NMI recursion
and stack corruption.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/kernel/entry.S b/arch/x86_64/kernel/entry.S
index dbdba56..cdf9cb1 100644
--- a/arch/x86_64/kernel/entry.S
+++ b/arch/x86_64/kernel/entry.S
@@ -922,7 +922,7 @@
 	.previous .text
 
 	/* runs on exception stack */	
-ENTRY(nmi)
+KPROBE_ENTRY(nmi)
 	INTR_FRAME
 	pushq $-1
 	CFI_ADJUST_CFA_OFFSET 8
@@ -969,6 +969,7 @@
 	cli
 	jmp paranoid_userspace
 	CFI_ENDPROC
+	.previous .text
 
 KPROBE_ENTRY(int3)
  	INTR_FRAME