port the changes just made to kvm_getfiles in kvm_file2.c r1.47 to

kvm_getprocs.

basically cope with the number of procs growing between when we get
the size and when we get the list.

ok guenther@

2 files changed, 30 insertions, 29 deletions

diff --git a/lib/libkvm/kvm.c b/lib/libkvm/kvm.c
index f784b5f013f..d9878911ef5 100644
--- a/lib/libkvm/kvm.c
+++ b/lib/libkvm/kvm.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kvm.c,v 1.57 2015/09/04 02:58:14 dlg Exp $ */
+/*	$OpenBSD: kvm.c,v 1.58 2015/09/08 15:40:32 dlg Exp $ */
 /*	$NetBSD: kvm.c,v 1.43 1996/05/05 04:31:59 gwr Exp $	*/
 
 /*-
@@ -184,7 +184,7 @@ _kvm_open(kvm_t *kd, const char *uf, const char *mf, const char *sf,
 	kd->nlfd = -1;
 	kd->alive = 0;
 	kd->filebase = NULL;
-	kd->procbase = 0;
+	kd->procbase = NULL;
 	kd->nbpg = getpagesize();
 	kd->swapspc = 0;
 	kd->argspc = 0;
@@ -654,8 +654,7 @@ kvm_close(kvm_t *kd)
 	if (kd->kcore_hdr != NULL)
 		free((void *)kd->kcore_hdr);
 	free(kd->filebase);
-	if (kd->procbase != 0)
-		free((void *)kd->procbase);
+	free(kd->procbase);
 	if (kd->swapspc != 0)
 		free((void *)kd->swapspc);
 	if (kd->argspc != 0)
diff --git a/lib/libkvm/kvm_proc2.c b/lib/libkvm/kvm_proc2.c
index 50e5521631f..52b74fe8815 100644
--- a/lib/libkvm/kvm_proc2.c
+++ b/lib/libkvm/kvm_proc2.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kvm_proc2.c,v 1.25 2014/10/15 02:03:05 deraadt Exp $	*/
+/*	$OpenBSD: kvm_proc2.c,v 1.26 2015/09/08 15:40:32 dlg Exp $	*/
 /*	$NetBSD: kvm_proc.c,v 1.30 1999/03/24 05:50:50 mrg Exp $	*/
 /*-
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -95,6 +95,7 @@
 #include <sys/sysctl.h>
 
 #include <limits.h>
+#include <errno.h>
 #include <db.h>
 #include <paths.h>
 
@@ -397,20 +398,12 @@ struct kinfo_proc *
 kvm_getprocs(kvm_t *kd, int op, int arg, size_t esize, int *cnt)
 {
 	int mib[6], st, nthreads;
+	void *procbase;
 	size_t size;
 
 	if ((ssize_t)esize < 0)
 		return (NULL);
 
-	if (kd->procbase != NULL) {
-		free(kd->procbase);
-		/*
-		 * Clear this pointer in case this call fails.  Otherwise,
-		 * kvm_close() will free it again.
-		 */
-		kd->procbase = 0;
-	}
-
 	if (ISALIVE(kd)) {
 		size = 0;
 		mib[0] = CTL_KERN;
@@ -418,22 +411,31 @@ kvm_getprocs(kvm_t *kd, int op, int arg, size_t esize, int *cnt)
 		mib[2] = op;
 		mib[3] = arg;
 		mib[4] = esize;
-		mib[5] = 0;
-		st = sysctl(mib, 6, NULL, &size, NULL, 0);
-		if (st == -1) {
-			_kvm_syserr(kd, kd->program, "kvm_getprocs");
-			return (NULL);
-		}
 
-		mib[5] = size / esize;
-		kd->procbase = _kvm_malloc(kd, size);
-		if (kd->procbase == 0)
-			return (NULL);
-		st = sysctl(mib, 6, kd->procbase, &size, NULL, 0);
-		if (st == -1) {
-			_kvm_syserr(kd, kd->program, "kvm_getprocs");
-			return (NULL);
-		}
+		do {
+			mib[5] = 0;
+			st = sysctl(mib, 6, NULL, &size, NULL, 0);
+			if (st == -1) {
+				_kvm_syserr(kd, kd->program, "kvm_getprocs");
+				return (NULL);
+			}
+
+			size += size / 8; /* add ~10% */
+
+			procbase = _kvm_realloc(kd, kd->procbase, size);
+			if (procbase == NULL)
+				return (NULL);
+
+			kd->procbase = procbase;
+
+			mib[5] = size / esize;
+			st = sysctl(mib, 6, kd->procbase, &size, NULL, 0);
+			if (st == -1 && errno != ENOMEM) {
+				_kvm_syserr(kd, kd->program, "kvm_getprocs");
+				return (NULL);
+			}
+		} while (st == -1);
+
 		nthreads = size / esize;
 	} else {
 		struct nlist nl[5];