Add a flag - KVM_NO_FILES which tells kvm_openfiles to not

open any files, just return an kvm handle that we can use to some
of the functions.

4 files changed, 25 insertions, 6 deletions

diff --git a/include/kvm.h b/include/kvm.h
index 9ecc806fcd7..fe46715d237 100644
--- a/include/kvm.h
+++ b/include/kvm.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kvm.h,v 1.4 2002/02/16 21:27:17 millert Exp $	*/
+/*	$OpenBSD: kvm.h,v 1.5 2002/06/08 22:31:24 art Exp $	*/
 /*	$NetBSD: kvm.h,v 1.7 1996/04/19 12:02:50 leo Exp $	*/
 
 /*-
@@ -43,6 +43,12 @@
 #define	VRS_SYM		"_version"
 #define	VRS_KEY		"VERSION"
 
+/*
+ * Flag for kvm_open* that disables opening of any files. We're just
+ * interested in a handle to run sysctls.
+ */
+#define KVM_NO_FILES	0x80000000
+
 #include <nlist.h>
 #include <sys/cdefs.h>
 #include <stdio.h>
diff --git a/lib/libkvm/kvm.c b/lib/libkvm/kvm.c
index 17684922068..4599cc48cfa 100644
--- a/lib/libkvm/kvm.c
+++ b/lib/libkvm/kvm.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kvm.c,v 1.30 2002/03/05 00:15:08 deraadt Exp $ */
+/*	$OpenBSD: kvm.c,v 1.31 2002/06/08 22:31:24 art Exp $ */
 /*	$NetBSD: kvm.c,v 1.43 1996/05/05 04:31:59 gwr Exp $	*/
 
 /*-
@@ -42,7 +42,7 @@
 #if 0
 static char sccsid[] = "@(#)kvm.c	8.2 (Berkeley) 2/13/94";
 #else
-static char *rcsid = "$OpenBSD: kvm.c,v 1.30 2002/03/05 00:15:08 deraadt Exp $";
+static char *rcsid = "$OpenBSD: kvm.c,v 1.31 2002/06/08 22:31:24 art Exp $";
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -191,6 +191,7 @@ _kvm_open(kd, uf, mf, sf, flag, errout)
 	kd->vmfd = -1;
 	kd->swfd = -1;
 	kd->nlfd = -1;
+	kd->alive = 0;
 	kd->procbase = 0;
 	kd->nbpg = getpagesize();
 	kd->swapspc = 0;
@@ -204,6 +205,11 @@ _kvm_open(kd, uf, mf, sf, flag, errout)
 	kd->cpu_data = 0;
 	kd->dump_off = 0;
 
+	if (flag & KVM_NO_FILES) {
+		kd->alive = 1;
+		return (kd);
+	}	
+
 	if (uf && strlen(uf) >= MAXPATHLEN) {
 		_kvm_err(kd, kd->program, "exec file name too long");
 		goto failed;
@@ -241,6 +247,7 @@ _kvm_open(kd, uf, mf, sf, flag, errout)
 			_kvm_syserr(kd, kd->program, "%s", _PATH_KMEM);
 			goto failed;
 		}
+		kd->alive = 1;
 		if ((kd->swfd = open(sf, flag, 0)) < 0) {
 			_kvm_syserr(kd, kd->program, "%s", sf);
 			goto failed;
@@ -641,6 +648,7 @@ kvm_close(kd)
 		error |= close(kd->pmfd);
 	if (kd->vmfd >= 0)
 		error |= close(kd->vmfd);
+	kd->alive = 0;
 	if (kd->nlfd >= 0)
 		error |= close(kd->nlfd);
 	if (kd->swfd >= 0)
diff --git a/lib/libkvm/kvm_open.3 b/lib/libkvm/kvm_open.3
index e1a694d39cd..c03dcc2bf04 100644
--- a/lib/libkvm/kvm_open.3
+++ b/lib/libkvm/kvm_open.3
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: kvm_open.3,v 1.6 2000/03/04 15:29:56 aaron Exp $
+.\"	$OpenBSD: kvm_open.3,v 1.7 2002/06/08 22:31:24 art Exp $
 .\"	$NetBSD: kvm_open.3,v 1.2 1996/03/18 22:33:52 thorpej Exp $
 .\"
 .\" Copyright (c) 1992, 1993
@@ -116,6 +116,10 @@ Only
 and
 .Dv O_RDWR
 are permitted.
+A special value
+.Dv KVM_NO_FILES
+can be specified which will cause no files to be opened and the handle
+can only be used on live kernels on a limited subset of all kvm operations.
 .Pp
 There are two open routines which differ only with respect to
 the error mechanism.
diff --git a/lib/libkvm/kvm_private.h b/lib/libkvm/kvm_private.h
index 2b88a2e8977..2eff0a80071 100644
--- a/lib/libkvm/kvm_private.h
+++ b/lib/libkvm/kvm_private.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kvm_private.h,v 1.6 2002/02/16 21:27:26 millert Exp $ */
+/*	$OpenBSD: kvm_private.h,v 1.7 2002/06/08 22:31:25 art Exp $ */
 /*	$NetBSD: kvm_private.h,v 1.7 1996/05/05 04:32:15 gwr Exp $	*/
 
 /*-
@@ -50,7 +50,6 @@ struct __kvm {
 	char	*errp;		/* XXX this can probably go away */
 	char	errbuf[_POSIX2_LINE_MAX];
 	DB	*db;
-#define ISALIVE(kd) ((kd)->vmfd >= 0)
 	int	pmfd;		/* physical memory file (or crashdump) */
 	int	vmfd;		/* virtual memory file (-1 if crashdump) */
 	int	swfd;		/* swap file (e.g., /dev/drum) */
@@ -85,6 +84,8 @@ struct __kvm {
 	 */
 	struct pglist *vm_page_buckets;
 	int vm_page_hash_mask;
+	int alive;	/* Dead or alive. */
+#define ISALIVE(kd) ((kd)->alive)
 };
 
 /*