All operation on live kernels uses sysctl interface, there is no reason to

access the swap area. Change kvm_open() to no longer require a swap area,
and to not consider failure to open() it as fatal. Post-mortem analysis
would need an image of the swap area at the time of the crash, anyway.

3 files changed, 10 insertions, 14 deletions

diff --git a/lib/libkvm/kvm.c b/lib/libkvm/kvm.c
index 393dd5971db..c8b5fd333b4 100644
--- a/lib/libkvm/kvm.c
+++ b/lib/libkvm/kvm.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kvm.c,v 1.45 2006/03/31 03:59:40 deraadt Exp $ */
+/*	$OpenBSD: kvm.c,v 1.46 2009/01/21 22:18:00 miod Exp $ */
 /*	$NetBSD: kvm.c,v 1.43 1996/05/05 04:31:59 gwr Exp $	*/
 
 /*-
@@ -38,7 +38,7 @@
 #if 0
 static char sccsid[] = "@(#)kvm.c	8.2 (Berkeley) 2/13/94";
 #else
-static char *rcsid = "$OpenBSD: kvm.c,v 1.45 2006/03/31 03:59:40 deraadt Exp $";
+static char *rcsid = "$OpenBSD: kvm.c,v 1.46 2009/01/21 22:18:00 miod Exp $";
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -213,8 +213,6 @@ _kvm_open(kvm_t *kd, const char *uf, const char *mf, const char *sf,
 	}
 	if (mf == 0)
 		mf = _PATH_MEM;
-	if (sf == 0)
-		sf = _PATH_DRUM;
 
 	if ((kd->pmfd = open(mf, flag, 0)) < 0) {
 		_kvm_syserr(kd, kd->program, "%s", mf);
@@ -241,7 +239,7 @@ _kvm_open(kvm_t *kd, const char *uf, const char *mf, const char *sf,
 			goto failed;
 		}
 		kd->alive = 1;
-		if ((kd->swfd = open(sf, flag, 0)) < 0) {
+		if (sf != NULL && (kd->swfd = open(sf, flag, 0)) < 0) {
 			_kvm_syserr(kd, kd->program, "%s", sf);
 			goto failed;
 		}
diff --git a/lib/libkvm/kvm_open.3 b/lib/libkvm/kvm_open.3
index ad8b8101908..d5c27805b07 100644
--- a/lib/libkvm/kvm_open.3
+++ b/lib/libkvm/kvm_open.3
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: kvm_open.3,v 1.12 2007/05/31 19:19:35 jmc Exp $
+.\"	$OpenBSD: kvm_open.3,v 1.13 2009/01/21 22:18:00 miod Exp $
 .\"	$NetBSD: kvm_open.3,v 1.2 1996/03/18 22:33:52 thorpej Exp $
 .\"
 .\" Copyright (c) 1992, 1993
@@ -34,7 +34,7 @@
 .\"
 .\"     @(#)kvm_open.3	8.3 (Berkeley) 4/19/94
 .\"
-.Dd $Mdocdate: May 31 2007 $
+.Dd $Mdocdate: January 21 2009 $
 .Dt KVM_OPEN 3
 .Os
 .Sh NAME
@@ -96,10 +96,7 @@ is used.
 should indicate the swap device.
 If
 .Dv NULL ,
-.Dv _PATH_DRUM
-from
-.Aq Pa paths.h
-is used.
+no swap device will be used.
 .Pp
 The
 .Fa flags
diff --git a/lib/libkvm/kvm_proc.c b/lib/libkvm/kvm_proc.c
index eea2060cfce..a38ce59087d 100644
--- a/lib/libkvm/kvm_proc.c
+++ b/lib/libkvm/kvm_proc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kvm_proc.c,v 1.36 2008/06/26 05:42:05 ray Exp $	*/
+/*	$OpenBSD: kvm_proc.c,v 1.37 2009/01/21 22:18:00 miod Exp $	*/
 /*	$NetBSD: kvm_proc.c,v 1.30 1999/03/24 05:50:50 mrg Exp $	*/
 /*-
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -66,7 +66,7 @@
 #if 0
 static char sccsid[] = "@(#)kvm_proc.c	8.3 (Berkeley) 9/23/93";
 #else
-static char *rcsid = "$OpenBSD: kvm_proc.c,v 1.36 2008/06/26 05:42:05 ray Exp $";
+static char *rcsid = "$OpenBSD: kvm_proc.c,v 1.37 2009/01/21 22:18:00 miod Exp $";
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -231,7 +231,8 @@ _kvm_ureadm(kvm_t *kd, const struct miniproc *p, u_long va, u_long *cnt)
 		    (size_t)kd->nbpg, (off_t)pg.phys_addr) != kd->nbpg)
 			return (NULL);
 	} else {
-		if (_kvm_pread(kd, kd->swfd, (void *)kd->swapspc,
+		if (kd->swfd == -1 ||
+		    _kvm_pread(kd, kd->swfd, (void *)kd->swapspc,
 		    (size_t)kd->nbpg,
 		    (off_t)(anon.an_swslot * kd->nbpg)) != kd->nbpg)
 			return (NULL);