[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>

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index 7db664d0b25c..2f6cb8276480 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -635,6 +635,8 @@ static void mem_parity_error(unsigned char reason, struct pt_regs * regs)
                         "to continue\n");
         printk(KERN_EMERG "You probably have a hardware problem with your RAM "
                         "chips\n");
+        if (panic_on_unrecovered_nmi)
+                panic("NMI: Not continuing");
 
         /* Clear and disable the memory parity error line. */
         clear_mem_error(reason);
@@ -670,6 +672,10 @@ static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
                 reason, smp_processor_id());
         printk("Dazed and confused, but trying to continue\n");
         printk("Do you have a strange power saving mode enabled?\n");
+
+        if (panic_on_unrecovered_nmi)
+                panic("NMI: Not continuing");
+
 }
 
 static DEFINE_SPINLOCK(nmi_print_lock);