Change the behavior of isa_nmi to log an error message instead of

panicing and return a status so that we can decide whether to drop
into DDB or panic.  If the status from isa_nmi is true, panic the
kernel based on machdep.panic_on_nmi, otherwise if DDB is
enabled, drop to DDB based on machdep.ddb_on_nmi.

Reviewed by:	peter, phk

1 files changed, 31 insertions, 9 deletions

diff --git a/sys/amd64/amd64/trap.c b/sys/amd64/amd64/trap.c
index 5a435fe..51de1ac 100644
--- a/sys/amd64/amd64/trap.c
+++ b/sys/amd64/amd64/trap.c
@@ -56,6 +56,7 @@
 #include <sys/resourcevar.h>
 #include <sys/signalvar.h>
 #include <sys/syscall.h>
+#include <sys/sysctl.h>
 #include <sys/sysent.h>
 #include <sys/uio.h>
 #include <sys/vmmeter.h>
@@ -147,6 +148,15 @@ static __inline int userret __P((struct proc *p, struct trapframe *frame,
 extern int has_f00f_bug;
 #endif
 
+#ifdef DDB
+static int ddb_on_nmi = 1;
+SYSCTL_INT(_machdep, OID_AUTO, ddb_on_nmi, CTLFLAG_RW,
+	&ddb_on_nmi, 0, "Go to DDB on NMI");
+#endif
+static int panic_on_nmi = 1;
+SYSCTL_INT(_machdep, OID_AUTO, panic_on_nmi, CTLFLAG_RW,
+	&panic_on_nmi, 0, "Panic on NMI");
+
 static __inline int
 userret(p, frame, oticks, have_mplock)
 	struct proc *p;
@@ -372,13 +382,19 @@ restart:
 			/* machine/parity/power fail/"kitchen sink" faults */
 			if (isa_nmi(code) == 0) {
 #ifdef DDB
-				/* NMI can be hooked up to a pushbutton for debugging */
-				printf ("NMI ... going to debugger\n");
-				kdb_trap (type, 0, &frame);
+				/*
+				 * NMI can be hooked up to a pushbutton
+				 * for debugging.
+				 */
+				if (ddb_on_nmi) {
+					printf ("NMI ... going to debugger\n");
+					kdb_trap (type, 0, &frame);
+				}
 #endif /* DDB */
 				return;
-			}
-			panic("NMI indicates hardware failure");
+			} else if (panic_on_nmi)
+				panic("NMI indicates hardware failure");
+			break;
 #endif /* POWERFAIL_NMI */
 #endif /* NISA > 0 */
 
@@ -577,12 +593,18 @@ kernel_trap:
 			/* machine/parity/power fail/"kitchen sink" faults */
 			if (isa_nmi(code) == 0) {
 #ifdef DDB
-				/* NMI can be hooked up to a pushbutton for debugging */
-				printf ("NMI ... going to debugger\n");
-				kdb_trap (type, 0, &frame);
+				/*
+				 * NMI can be hooked up to a pushbutton
+				 * for debugging.
+				 */
+				if (ddb_on_nmi) {
+					printf ("NMI ... going to debugger\n");
+					kdb_trap (type, 0, &frame);
+				}
 #endif /* DDB */
 				return;
-			}
+			} else if (panic_on_nmi == 0)
+				return;
 			/* FALL THROUGH */
 #endif /* POWERFAIL_NMI */
 #endif /* NISA > 0 */