[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>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/x86_64/kernel/entry.S b/arch/x86_64/kernel/entry.S
index dbdba56e8faa..cdf9cb1288c1 100644
--- a/arch/x86_64/kernel/entry.S
+++ b/arch/x86_64/kernel/entry.S
@@ -922,7 +922,7 @@ KPROBE_ENTRY(debug)
         .previous .text
 
         /* runs on exception stack */   
-ENTRY(nmi)
+KPROBE_ENTRY(nmi)
         INTR_FRAME
         pushq $-1
         CFI_ADJUST_CFA_OFFSET 8
@@ -969,6 +969,7 @@ paranoid_schedule:
         cli
         jmp paranoid_userspace
         CFI_ENDPROC
+        .previous .text
 
 KPROBE_ENTRY(int3)
         INTR_FRAME