Improved DDB_UNATTENDED behaviour. From the submitter:

  There's something that's been bugging me for a while, so I decided to fix it.
FreeBSD now will DTRT WRT DDB and DDB_UNATTENDED (!debugger_on_panic), at least
in my opinion. The behavior change is such that:

	1. Nothing changes when debugger_on_panic != 0.
	2. When DDB_UNATTENDED (!debugger_on_panic), if a panic occurs, the
		machine will reboot. Also, if a trap occurs, the machine will
		panic and reboot, unlike how it broke to DDB before. HOWEVER,
		a trap inside DDB will not cause a panic, allowing full use
		of DDB without having to worry about the machine being stuck
		at a DDB prompt if something goes wrong during the day.
		Patches for this behavior follow my signature, and it would
		be a boon to anyone (like me) who uses DDB_UNATTENDED, but
		actually wants the machine to panic on a trap (otherwise,
		what's the use, if the machine causes a fatal trap rather than
		a true panic, of debugger_on_panic?). The changes cause no
		adverse behavior, but do involve two symbols becoming global

Submitted by:	Brian Feldman <green@unixhelp.org>

6 files changed, 27 insertions, 13 deletions

diff --git a/sys/amd64/amd64/db_interface.c b/sys/amd64/amd64/db_interface.c
index 0b53ed23..7f01f1d 100644
--- a/sys/amd64/amd64/db_interface.c
+++ b/sys/amd64/amd64/db_interface.c
@@ -23,7 +23,7 @@
  * any improvements or extensions that they make and grant Carnegie the
  * rights to redistribute these changes.
  *
- *	$Id: db_interface.c,v 1.41 1998/06/08 09:23:24 dfr Exp $
+ *	$Id: db_interface.c,v 1.42 1998/12/14 05:34:33 dillon Exp $
  */
 
 /*
@@ -295,11 +295,12 @@ db_write_bytes(addr, size, data)
  * Move this to machdep.c and allow it to be called if any debugger is
  * installed.
  */
+volatile int in_Debugger = 0;
+
 void
 Debugger(msg)
 	const char *msg;
 {
-	static volatile u_char in_Debugger;
 
 	/*
 	 * XXX
diff --git a/sys/amd64/amd64/trap.c b/sys/amd64/amd64/trap.c
index 3d35483..e672368 100644
--- a/sys/amd64/amd64/trap.c
+++ b/sys/amd64/amd64/trap.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)trap.c	7.4 (Berkeley) 5/13/91
- *	$Id: trap.c,v 1.130 1998/12/06 00:03:30 archie Exp $
+ *	$Id: trap.c,v 1.131 1998/12/16 15:21:50 bde Exp $
  */
 
 /*
@@ -93,6 +93,10 @@
 #include <machine/vm86.h>
 #endif
 
+#ifdef DDB
+	extern int in_Debugger, debugger_on_panic;
+#endif
+
 #include "isa.h"
 #include "npx.h"
 
@@ -901,7 +905,7 @@ trap_fatal(frame, eva)
 		return;
 #endif
 #ifdef DDB
-	if (kdb_trap (type, 0, frame))
+	if ((debugger_on_panic || in_Debugger) && kdb_trap(type, 0, frame))
 		return;
 #endif
 	printf("trap number		= %d\n", type);
diff --git a/sys/i386/i386/db_interface.c b/sys/i386/i386/db_interface.c
index 0b53ed23..7f01f1d 100644
--- a/sys/i386/i386/db_interface.c
+++ b/sys/i386/i386/db_interface.c
@@ -23,7 +23,7 @@
  * any improvements or extensions that they make and grant Carnegie the
  * rights to redistribute these changes.
  *
- *	$Id: db_interface.c,v 1.41 1998/06/08 09:23:24 dfr Exp $
+ *	$Id: db_interface.c,v 1.42 1998/12/14 05:34:33 dillon Exp $
  */
 
 /*
@@ -295,11 +295,12 @@ db_write_bytes(addr, size, data)
  * Move this to machdep.c and allow it to be called if any debugger is
  * installed.
  */
+volatile int in_Debugger = 0;
+
 void
 Debugger(msg)
 	const char *msg;
 {
-	static volatile u_char in_Debugger;
 
 	/*
 	 * XXX
diff --git a/sys/i386/i386/trap.c b/sys/i386/i386/trap.c
index 3d35483..e672368 100644
--- a/sys/i386/i386/trap.c
+++ b/sys/i386/i386/trap.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)trap.c	7.4 (Berkeley) 5/13/91
- *	$Id: trap.c,v 1.130 1998/12/06 00:03:30 archie Exp $
+ *	$Id: trap.c,v 1.131 1998/12/16 15:21:50 bde Exp $
  */
 
 /*
@@ -93,6 +93,10 @@
 #include <machine/vm86.h>
 #endif
 
+#ifdef DDB
+	extern int in_Debugger, debugger_on_panic;
+#endif
+
 #include "isa.h"
 #include "npx.h"
 
@@ -901,7 +905,7 @@ trap_fatal(frame, eva)
 		return;
 #endif
 #ifdef DDB
-	if (kdb_trap (type, 0, frame))
+	if ((debugger_on_panic || in_Debugger) && kdb_trap(type, 0, frame))
 		return;
 #endif
 	printf("trap number		= %d\n", type);
diff --git a/sys/kern/kern_shutdown.c b/sys/kern/kern_shutdown.c
index 3a2c650..4d6db41 100644
--- a/sys/kern/kern_shutdown.c
+++ b/sys/kern/kern_shutdown.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)kern_shutdown.c	8.3 (Berkeley) 1/21/94
- * $Id: kern_shutdown.c,v 1.42 1998/11/13 22:40:37 msmith Exp $
+ * $Id: kern_shutdown.c,v 1.43 1998/12/04 22:54:51 archie Exp $
  */
 
 #include "opt_ddb.h"
@@ -80,9 +80,9 @@
 
 #ifdef DDB
 #ifdef DDB_UNATTENDED
-static int debugger_on_panic = 0;
+int debugger_on_panic = 0;
 #else
-static int debugger_on_panic = 1;
+int debugger_on_panic = 1;
 #endif
 SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, CTLFLAG_RW,
 	&debugger_on_panic, 0, "");
diff --git a/sys/kern/subr_trap.c b/sys/kern/subr_trap.c
index 3d35483..e672368 100644
--- a/sys/kern/subr_trap.c
+++ b/sys/kern/subr_trap.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)trap.c	7.4 (Berkeley) 5/13/91
- *	$Id: trap.c,v 1.130 1998/12/06 00:03:30 archie Exp $
+ *	$Id: trap.c,v 1.131 1998/12/16 15:21:50 bde Exp $
  */
 
 /*
@@ -93,6 +93,10 @@
 #include <machine/vm86.h>
 #endif
 
+#ifdef DDB
+	extern int in_Debugger, debugger_on_panic;
+#endif
+
 #include "isa.h"
 #include "npx.h"
 
@@ -901,7 +905,7 @@ trap_fatal(frame, eva)
 		return;
 #endif
 #ifdef DDB
-	if (kdb_trap (type, 0, frame))
+	if ((debugger_on_panic || in_Debugger) && kdb_trap(type, 0, frame))
 		return;
 #endif
 	printf("trap number		= %d\n", type);