diff --git a/usr.sbin/config/config.y b/usr.sbin/config/config.y
index 91fbf24c2c8a..c35127c49cf8 100644
--- a/usr.sbin/config/config.y
+++ b/usr.sbin/config/config.y
@@ -125,8 +125,8 @@
 
 struct	device cur;
 struct	device *curp = 0;
-char	*temp_id;
-char	*val_id;
+
+#define ns(s)	strdup(s)
 
 %}
 %%
@@ -188,17 +188,16 @@ Config_spec:
 		struct cputype *cp =
 		    (struct cputype *)malloc(sizeof (struct cputype));
 		memset(cp, 0, sizeof(*cp));
-		cp->cpu_name = ns($2);
+		cp->cpu_name = $2;
 		cp->cpu_next = cputype;
 		cputype = cp;
-		free(temp_id);
 	      } |
 	OPTIONS Opt_list
 		|
 	MAKEOPTIONS Mkopt_list
 		|
 	IDENT ID
-	      = { ident = ns($2); } |
+	      = { ident = $2; } |
 	System_spec
 		|
 	MAXUSERS NUMBER
@@ -397,7 +396,7 @@ Option:
 		struct opt *op = (struct opt *)malloc(sizeof (struct opt));
 		char *s;
 		memset(op, 0, sizeof(*op));
-		op->op_name = ns($1);
+		op->op_name = $1;
 		op->op_next = opt;
 		op->op_value = 0;
 		opt = op;
@@ -406,34 +405,31 @@ Option:
 			*s = '\0';
 			op->op_value = ns(s + 1);
 		}
-		free(temp_id);
 	      } |
 	Save_id EQUALS Opt_value
 	      = {
 		struct opt *op = (struct opt *)malloc(sizeof (struct opt));
 		memset(op, 0, sizeof(*op));
-		op->op_name = ns($1);
+		op->op_name = $1;
 		op->op_next = opt;
-		op->op_value = ns($3);
+		op->op_value = $3;
 		opt = op;
-		free(temp_id);
-		free(val_id);
 	      } ;
 
 Opt_value:
 	ID
-	      = { $$ = val_id = ns($1); } |
+	      = { $$ = $1; } |
 	NUMBER
 	      = {
 		char nb[16];
 	        (void) sprintf(nb, "%d", $1);
-		$$ = val_id = ns(nb);
+		$$ = ns(nb);
 	      } ;
 
 
 Save_id:
 	ID
-	      = { $$ = temp_id = ns($1); }
+	      = { $$ = $1; }
 	;
 
 Mkopt_list:
@@ -447,18 +443,16 @@ Mkoption:
 	      = {
 		struct opt *op = (struct opt *)malloc(sizeof (struct opt));
 		memset(op, 0, sizeof(*op));
-		op->op_name = ns($1);
+		op->op_name = $1;
 		op->op_ownfile = 0;	/* for now */
 		op->op_next = mkopt;
-		op->op_value = ns($3);
+		op->op_value = $3;
 		mkopt = op;
-		free(temp_id);
-		free(val_id);
 	      } ;
 
 Dev:
 	ID
-	      = { $$ = ns($1); }
+	      = { $$ = $1; }
 	;
 
 Device_spec:
@@ -620,7 +614,7 @@ Info:
 	IOSIZ NUMBER
 	      = { cur.d_msize = $2; } |
 	PORT device_name
-	      = { cur.d_port = ns($2); } |
+	      = { cur.d_port = $2; } |
 	PORT NUMBER
 	      = { cur.d_portn = $2; } |
 	PORT AUTO
@@ -671,20 +665,6 @@ yyerror(s)
 	fprintf(stderr, "config: line %d: %s\n", yyline + 1, s);
 }
 
-/*
- * return the passed string in a new space
- */
-char *
-ns(str)
-	register char *str;
-{
-	register char *cp;
-
-	cp = malloc((unsigned)(strlen(str)+1));
-	(void) strcpy(cp, str);
-	return (cp);
-}
-
 /*
  * add a device to the list of devices
  */
diff --git a/usr.sbin/config/mkheaders.c b/usr.sbin/config/mkheaders.c
index bfa56926f479..735658d24495 100644
--- a/usr.sbin/config/mkheaders.c
+++ b/usr.sbin/config/mkheaders.c
@@ -40,10 +40,13 @@ static char sccsid[] = "@(#)mkheaders.c	8.1 (Berkeley) 6/6/93";
  */
 
 #include <stdio.h>
+#include <string.h>
 #include <ctype.h>
 #include "config.h"
 #include "y.tab.h"
 
+#define ns(s) strdup(s)
+
 headers()
 {
 	register struct file_list *fl;
@@ -157,7 +160,7 @@ do_header(dev, hname, count)
 	if (oldcount == -1) {
 		fl = (struct file_list *) malloc(sizeof *fl);
 		bzero(fl, sizeof(*fl));
-		fl->f_fn = ns(name); /* malloced */
+		fl->f_fn = ns(name);
 		fl->f_type = count;
 		fl->f_next = fl_head;
 		fl_head = fl;
diff --git a/usr.sbin/config/mkmakefile.c b/usr.sbin/config/mkmakefile.c
index 513a5037a73c..56aa44a44eab 100644
--- a/usr.sbin/config/mkmakefile.c
+++ b/usr.sbin/config/mkmakefile.c
@@ -42,6 +42,7 @@ static char sccsid[] = "@(#)mkmakefile.c	8.1 (Berkeley) 6/6/93";
  */
 
 #include <stdio.h>
+#include <string.h>
 #include <ctype.h>
 #include "y.tab.h"
 #include "config.h"
@@ -61,6 +62,8 @@ static char sccsid[] = "@(#)mkmakefile.c	8.1 (Berkeley) 6/6/93";
 		wd = word; \
 	}
 
+#define ns(s) strdup(s)
+
 static	struct file_list *fcur;
 char *tail();
 extern int old_config_present;
diff --git a/usr.sbin/config/mkoptions.c b/usr.sbin/config/mkoptions.c
index 40fe87e82974..aea47b676f09 100644
--- a/usr.sbin/config/mkoptions.c
+++ b/usr.sbin/config/mkoptions.c
@@ -41,10 +41,15 @@ static char sccsid[] = "@(#)mkheaders.c	8.1 (Berkeley) 6/6/93";
  */
 
 #include <stdio.h>
+#include <string.h>
 #include <ctype.h>
 #include "config.h"
 #include "y.tab.h"
 
+#define ns(s) strdup(s)
+
+static	char *lower __P((char *));
+
 options()
 {
 	struct opt_list *ol;
@@ -57,7 +62,7 @@ options()
 	for (cp = cputype; cp; cp = cp->cpu_next) {
 		struct opt *op = (struct opt *)malloc(sizeof (struct opt));
 		memset(op, 0, sizeof(*op));
-		op->op_name = cp->cpu_name;
+		op->op_name = ns(cp->cpu_name);
 		op->op_value = 0;
 		op->op_next = opt;
 		opt = op;
@@ -226,7 +231,6 @@ read_options()
 	struct opt_list *po;
 	int first = 1;
 	char genopt[80];
-	char *lower();
 
 	otab = 0;
 	(void) snprintf(fname, sizeof fname, "../../conf/options");
@@ -298,7 +302,7 @@ read_options()
 	goto next;
 }
 
-char *
+static char *
 lower(str)
 	register char *str;
 {
diff --git a/usr.sbin/config/mkswapconf.c b/usr.sbin/config/mkswapconf.c
index 1d5756ff1ff2..18a80844915f 100644
--- a/usr.sbin/config/mkswapconf.c
+++ b/usr.sbin/config/mkswapconf.c
@@ -45,6 +45,9 @@ static char sccsid[] = "@(#)mkswapconf.c	8.1 (Berkeley) 6/6/93";
 
 #include <ctype.h>
 #include <stdio.h>
+#include <string.h>
+
+#define ns(s) strdup(s)
 
 swapconf()
 {