From 45a0b8946847278eb6106b4662d39089527de426 Mon Sep 17 00:00:00 2001
From: Poul-Henning Kamp <phk@FreeBSD.org>
Date: Sun, 2 Oct 1994 19:36:30 +0000
Subject: [PATCH] Avoid ddb getting a panic if the code-segment isn't the usual
 one...

---
 sys/amd64/include/db_machdep.h |  4 ++--
 sys/ddb/db_trap.c              | 19 +++++++++++--------
 sys/i386/include/db_machdep.h  |  4 ++--
 3 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/sys/amd64/include/db_machdep.h b/sys/amd64/include/db_machdep.h
index 8145d3a48e17..310c43bbffb2 100644
--- a/sys/amd64/include/db_machdep.h
+++ b/sys/amd64/include/db_machdep.h
@@ -23,7 +23,7 @@
  * any improvements or extensions that they make and grant Carnegie Mellon
  * the rights to redistribute these changes.
  *
- *	$Id: db_machdep.h,v 1.3 1993/11/07 17:42:50 wollman Exp $
+ *	$Id: db_machdep.h,v 1.4 1994/09/08 11:49:04 bde Exp $
  */
 
 #ifndef	_I386_DB_MACHDEP_H_
@@ -55,7 +55,7 @@ typedef struct i386_saved_state db_regs_t;
 extern db_regs_t	ddb_regs;	/* register state */
 #define	DDB_REGS	(&ddb_regs)
 
-#define	PC_REGS(regs)	((db_addr_t)(regs)->tf_eip)
+#define	PC_REGS(regs)	((regs)->tf_cs == 0x08 ? (db_addr_t)(regs)->tf_eip : 0)
 
 #define	BKPT_INST	0xcc		/* breakpoint instruction */
 #define	BKPT_SIZE	(1)		/* size of breakpoint inst */
diff --git a/sys/ddb/db_trap.c b/sys/ddb/db_trap.c
index 8d2941ab5f88..bc65ed976242 100644
--- a/sys/ddb/db_trap.c
+++ b/sys/ddb/db_trap.c
@@ -23,7 +23,7 @@
  * any improvements or extensions that they make and grant Carnegie the
  * rights to redistribute these changes.
  *
- *	$Id: db_trap.c,v 1.4 1994/08/13 03:49:24 wollman Exp $
+ *	$Id: db_trap.c,v 1.5 1994/08/18 22:34:27 wollman Exp $
  */
 
 /*
@@ -57,14 +57,17 @@ db_trap(type, code)
 		db_printf("After %d instructions (%d loads, %d stores),\n",
 			  db_inst_count, db_load_count, db_store_count);
 	    }
-	    if (bkpt)
-		db_printf("Breakpoint at\t");
-	    else if (watchpt)
-		db_printf("Watchpoint at\t");
-	    else
-		db_printf("Stopped at\t");
 	    db_dot = PC_REGS(DDB_REGS);
-	    db_print_loc_and_inst(db_dot);
+	    if(db_dot) {
+		if (bkpt)
+		    db_printf("Breakpoint at\t");
+		else if (watchpt)
+		    db_printf("Watchpoint at\t");
+		else
+		    db_printf("Stopped at\t");
+		    
+		db_print_loc_and_inst(db_dot);
+		}
 
 	    db_command_loop();
 	}
diff --git a/sys/i386/include/db_machdep.h b/sys/i386/include/db_machdep.h
index 8145d3a48e17..310c43bbffb2 100644
--- a/sys/i386/include/db_machdep.h
+++ b/sys/i386/include/db_machdep.h
@@ -23,7 +23,7 @@
  * any improvements or extensions that they make and grant Carnegie Mellon
  * the rights to redistribute these changes.
  *
- *	$Id: db_machdep.h,v 1.3 1993/11/07 17:42:50 wollman Exp $
+ *	$Id: db_machdep.h,v 1.4 1994/09/08 11:49:04 bde Exp $
  */
 
 #ifndef	_I386_DB_MACHDEP_H_
@@ -55,7 +55,7 @@ typedef struct i386_saved_state db_regs_t;
 extern db_regs_t	ddb_regs;	/* register state */
 #define	DDB_REGS	(&ddb_regs)
 
-#define	PC_REGS(regs)	((db_addr_t)(regs)->tf_eip)
+#define	PC_REGS(regs)	((regs)->tf_cs == 0x08 ? (db_addr_t)(regs)->tf_eip : 0)
 
 #define	BKPT_INST	0xcc		/* breakpoint instruction */
 #define	BKPT_SIZE	(1)		/* size of breakpoint inst */