2 files changed, 24 insertions, 16 deletions

diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c
index d88004343034..bd96ea4f2942 100644
--- a/arch/i386/kernel/nmi.c
+++ b/arch/i386/kernel/nmi.c
@@ -781,7 +781,7 @@ EXPORT_SYMBOL(touch_nmi_watchdog);
 
 extern void die_nmi(struct pt_regs *, const char *msg);
 
-void nmi_watchdog_tick (struct pt_regs * regs, unsigned reason)
+int nmi_watchdog_tick (struct pt_regs * regs, unsigned reason)
 {
 
 	/*
@@ -794,10 +794,12 @@ void nmi_watchdog_tick (struct pt_regs * regs, unsigned reason)
 	int cpu = smp_processor_id();
 	struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
 	u64 dummy;
+	int rc=0;
 
 	/* check for other users first */
 	if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT)
 			== NOTIFY_STOP) {
+		rc = 1;
 		touched = 1;
 	}
 
@@ -850,10 +852,18 @@ void nmi_watchdog_tick (struct pt_regs * regs, unsigned reason)
 			}
 			/* start the cycle over again */
 			write_watchdog_counter(wd->perfctr_msr, NULL);
-		}
+			rc = 1;
+		} else if (nmi_watchdog == NMI_IO_APIC) {
+			/* don't know how to accurately check for this.
+			 * just assume it was a watchdog timer interrupt
+			 * This matches the old behaviour.
+			 */
+			rc = 1;
+		} else
+			printk(KERN_WARNING "Unknown enabled NMI hardware?!\n");
 	}
 done:
-	return;
+	return rc;
 }
 
 #ifdef CONFIG_SYSCTL
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index 3a07b2677e2a..282f0bd40dfd 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -706,6 +706,13 @@ void die_nmi (struct pt_regs *regs, const char *msg)
 	do_exit(SIGSEGV);
 }
 
+static int dummy_nmi_callback(struct pt_regs * regs, int cpu)
+{
+	return 0;
+}
+
+static nmi_callback_t nmi_callback = dummy_nmi_callback;
+
 static void default_do_nmi(struct pt_regs * regs)
 {
 	unsigned char reason = 0;
@@ -723,12 +730,11 @@ static void default_do_nmi(struct pt_regs * regs)
 		 * Ok, so this is none of the documented NMI sources,
 		 * so it must be the NMI watchdog.
 		 */
-		if (nmi_watchdog) {
-			nmi_watchdog_tick(regs, reason);
+		if (nmi_watchdog_tick(regs, reason))
 			return;
-		}
 #endif
-		unknown_nmi_error(reason, regs);
+		if (!rcu_dereference(nmi_callback)(regs, smp_processor_id()))
+			unknown_nmi_error(reason, regs);
 		return;
 	}
 	if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
@@ -744,13 +750,6 @@ static void default_do_nmi(struct pt_regs * regs)
 	reassert_nmi();
 }
 
-static int dummy_nmi_callback(struct pt_regs * regs, int cpu)
-{
-	return 0;
-}
- 
-static nmi_callback_t nmi_callback = dummy_nmi_callback;
- 
 fastcall void do_nmi(struct pt_regs * regs, long error_code)
 {
 	int cpu;
@@ -761,8 +760,7 @@ fastcall void do_nmi(struct pt_regs * regs, long error_code)
 
 	++nmi_count(cpu);
 
-	if (!rcu_dereference(nmi_callback)(regs, cpu))
-		default_do_nmi(regs);
+	default_do_nmi(regs);
 
 	nmi_exit();
 }