[PATCH] x86: Allow users to force a panic on NMI

To quote Alan Cox:

The default Linux behaviour on an NMI of either memory or unknown is to
continue operation. For many environments such as scientific computing
it is preferable that the box is taken out and the error dealt with than
an uncorrected parity/ECC error get propogated.

A small number of systems do generate NMI's for bizarre random reasons
such as power management so the default is unchanged. In other respects
the new proc/sys entry works like the existing panic controls already in
that directory.

This is separate to the edac support - EDAC allows supported chipsets to
handle ECC errors well, this change allows unsupported cases to at least
panic rather than cause problems further down the line.

Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Andi Kleen <ak@suse.de>

2 files changed, 9 insertions, 0 deletions

diff --git a/kernel/panic.c b/kernel/panic.c
index 8010b9b17aca..d2db3e2209e0 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -21,6 +21,7 @@
 #include <linux/debug_locks.h>
 
 int panic_on_oops;
+int panic_on_unrecovered_nmi;
 int tainted;
 static int pause_on_oops;
 static int pause_on_oops_flag;
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 040de6bd74dd..220e20564124 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -642,6 +642,14 @@ static ctl_table kern_table[] = {
 #endif
 #if defined(CONFIG_X86)
         {
+                .ctl_name       = KERN_PANIC_ON_NMI,
+                .procname       = "panic_on_unrecovered_nmi",
+                .data           = &panic_on_unrecovered_nmi,
+                .maxlen         = sizeof(int),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec,
+        },
+        {
                 .ctl_name       = KERN_BOOTLOADER_TYPE,
                 .procname       = "bootloader_type",
                 .data           = &bootloader_type,