[PATCH] i386: Disallow kprobes on NMI handlers
A kprobe executes IRET early and that could cause NMI recursion and stack
corruption.
Note: This problem was originally spotted and solved by Andi Kleen in the
x86_64 architecture. This patch is an adaption of his patch for i386.
AK: Merged with current code which was a bit different.
AK: Removed printk in nmi handler that shouldn't be there in the first time
AK: Added missing include.
AK: added KPROBES_END
Signed-off-by: Fernando Vazquez <fernando@intellilink.co.jp>
Signed-off-by: Andi Kleen <ak@suse.de>
diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
index dede506..0928f70 100644
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -729,7 +729,7 @@
* check whether we got an NMI on the debug path where the debug
* fault happened on the sysenter path.
*/
-ENTRY(nmi)
+KPROBE_ENTRY(nmi)
RING0_INT_FRAME
pushl %eax
CFI_ADJUST_CFA_OFFSET 4
@@ -805,6 +805,7 @@
.align 4
.long 1b,iret_exc
.previous
+KPROBE_END(nmi)
KPROBE_ENTRY(int3)
RING0_INT_FRAME