Module Name: src
Committed By: dholland
Date: Sat Nov 28 15:06:55 UTC 2015
Modified Files:
src/sys/arch/amd64/amd64: trap.c
Log Message:
If the kernel jumps to NULL, print where it came from instead of trying
to dereference and faulting again.
To generate a diff of this commit:
cvs rdiff -u -r1.81 -r1.82 src/sys/arch/amd64/amd64/trap.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/amd64/amd64/trap.c
diff -u src/sys/arch/amd64/amd64/trap.c:1.81 src/sys/arch/amd64/amd64/trap.c:1.82
--- src/sys/arch/amd64/amd64/trap.c:1.81 Sun Nov 22 13:41:24 2015
+++ src/sys/arch/amd64/amd64/trap.c Sat Nov 28 15:06:55 2015
@@ -1,4 +1,4 @@
-/* $NetBSD: trap.c,v 1.81 2015/11/22 13:41:24 maxv Exp $ */
+/* $NetBSD: trap.c,v 1.82 2015/11/28 15:06:55 dholland Exp $ */
/*-
* Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
@@ -68,7 +68,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.81 2015/11/22 13:41:24 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.82 2015/11/28 15:06:55 dholland Exp $");
#include "opt_ddb.h"
#include "opt_kgdb.h"
@@ -342,6 +342,16 @@ kernelfault:
/* Get %rsp value before fault - there may be a pad word
* below the trap frame. */
vframe = (void *)frame->tf_rsp;
+ if (frame->tf_rip == 0) {
+ /*
+ * Assume that if we jumped to null we
+ * probably did it via a null function
+ * pointer, so print the return address.
+ */
+ printf("kernel jumped to null; return addr was %p\n",
+ *(void **)frame->tf_rsp);
+ goto we_re_toast;
+ }
switch (*(uint16_t *)frame->tf_rip) {
case 0xcf48: /* iretq */
/*
