From a650e4d7c781bcb8119778619b32e381058aa2b7 Mon Sep 17 00:00:00 2001
From: Dale Rahn <drahn@cvs.openbsd.org>
Date: Sun, 9 Sep 2001 23:56:41 +0000
Subject: Protect debugger accesses with setfault. Should improve debugger
 usability, need to verify that kernel exception code deals with this
 properly.

---
 sys/arch/macppc/macppc/db_memrw.c | 48 +++++++++++++++++++++++----------------
 sys/arch/macppc/macppc/db_trace.c |  6 +++--
 2 files changed, 32 insertions(+), 22 deletions(-)

(limited to 'sys/arch')

diff --git a/sys/arch/macppc/macppc/db_memrw.c b/sys/arch/macppc/macppc/db_memrw.c
index 8c8e400175b..226c2417bfd 100644
--- a/sys/arch/macppc/macppc/db_memrw.c
+++ b/sys/arch/macppc/macppc/db_memrw.c
@@ -1,5 +1,5 @@
 /*	$NetBSD: db_memrw.c,v 1.4 2001/05/18 20:38:27 matt Exp $	*/
-/*	$OpenBSD: db_memrw.c,v 1.1 2001/09/01 15:44:20 drahn Exp $	*/
+/*	$OpenBSD: db_memrw.c,v 1.2 2001/09/09 23:56:40 drahn Exp $	*/
 
 /* 
  * Mach Operating System
@@ -45,6 +45,7 @@
 #include <vm/vm.h>
 
 #include <machine/db_machdep.h>
+#include <machine/pcb.h>
 
 #include <ddb/db_access.h>
 
@@ -58,21 +59,24 @@ db_read_bytes(addr, size, data)
 	register char	*data;
 {
 	register char	*src = (char*)addr;
-
-	if (size == 4) {
-		*((int*)data) = *((int*)src);
+	faultbuf env;
+	faultbuf *old_onfault = curpcb->pcb_onfault;
+	if (setfault(env)) {
+		curpcb->pcb_onfault = old_onfault;
 		return;
 	}
 
-	if (size == 2) {
+	if (size == 4) {
+		*((int*)data) = *((int*)src);
+	} else if (size == 2) {
 		*((short*)data) = *((short*)src);
-		return;
-	}
-
-	while (size > 0) {
-		--size;
-		*data++ = *src++;
+	} else {
+		while (size > 0) {
+			--size;
+			*data++ = *src++;
+		}
 	}
+	curpcb->pcb_onfault = old_onfault;
 }
 
 /*
@@ -85,21 +89,25 @@ db_write_bytes(addr, size, data)
 	register char	*data;
 {
 	register char	*dst = (char *)addr;
+	faultbuf env;
+	faultbuf *old_onfault = curpcb->pcb_onfault;
 
-	if (size == 4) {
-		*((int*)dst) = *((int*)data);
+	if (setfault(env)) {
+		curpcb->pcb_onfault = old_onfault;
 		return;
 	}
 
-	if (size == 2) {
+	if (size == 4) {
+		*((int*)dst) = *((int*)data);
+	} else if (size == 2) {
 		*((short*)dst) = *((short*)data);
-		return;
-	}
-
-	while (size > 0) {
-		--size;
-		*dst++ = *data++;
+	} else  {
+		while (size > 0) {
+			--size;
+			*dst++ = *data++;
+		}
 	}
 	syncicache((void *)addr, size);
+	curpcb->pcb_onfault = old_onfault;
 }
 
diff --git a/sys/arch/macppc/macppc/db_trace.c b/sys/arch/macppc/macppc/db_trace.c
index ef077301df9..8b329da05ef 100644
--- a/sys/arch/macppc/macppc/db_trace.c
+++ b/sys/arch/macppc/macppc/db_trace.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: db_trace.c,v 1.3 2001/09/05 20:49:55 drahn Exp $	*/
+/*	$OpenBSD: db_trace.c,v 1.4 2001/09/09 23:56:40 drahn Exp $	*/
 /*	$NetBSD: db_trace.c,v 1.15 1996/02/22 23:23:41 gwr Exp $	*/
 
 /*
@@ -100,11 +100,13 @@ int
 db_read32(u_int32_t paddr, u_int32_t *value)
 {
 	faultbuf env;
+	faultbuf *old_onfault = curpcb->pcb_onfault;
 	if (setfault(env)) {
-		curpcb->pcb_onfault = 0;
+		curpcb->pcb_onfault = old_onfault;
 		return EFAULT;
 	}
 	*value = *(u_int32_t *)paddr;
+	curpcb->pcb_onfault = old_onfault;
 	return 0;
 }
 
-- 
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