From owner-svn-src-all@FreeBSD.ORG  Thu Jul 10 21:46:57 2014
Return-Path: <owner-svn-src-all@FreeBSD.ORG>
Delivered-To: svn-src-all@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115])
 (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTPS id A71F996A;
 Thu, 10 Jul 2014 21:46:57 +0000 (UTC)
Received: from svn.freebsd.org (svn.freebsd.org
 [IPv6:2001:1900:2254:2068::e6a:0])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id 94FB02814;
 Thu, 10 Jul 2014 21:46:57 +0000 (UTC)
Received: from svn.freebsd.org ([127.0.1.70])
 by svn.freebsd.org (8.14.8/8.14.8) with ESMTP id s6ALkvxW032882;
 Thu, 10 Jul 2014 21:46:57 GMT (envelope-from mjg@svn.freebsd.org)
Received: (from mjg@localhost)
 by svn.freebsd.org (8.14.8/8.14.8/Submit) id s6ALkvLC032881;
 Thu, 10 Jul 2014 21:46:57 GMT (envelope-from mjg@svn.freebsd.org)
Message-Id: <201407102146.s6ALkvLC032881@svn.freebsd.org>
From: Mateusz Guzik <mjg@FreeBSD.org>
Date: Thu, 10 Jul 2014 21:46:57 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-head@freebsd.org
Subject: svn commit: r268509 - head/sys/kern
X-SVN-Group: head
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-BeenThere: svn-src-all@freebsd.org
X-Mailman-Version: 2.1.18
Precedence: list
List-Id: "SVN commit messages for the entire src tree \(except for &quot;
 user&quot; and &quot; projects&quot; \)" <svn-src-all.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/svn-src-all>,
 <mailto:svn-src-all-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-all/>
List-Post: <mailto:svn-src-all@freebsd.org>
List-Help: <mailto:svn-src-all-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-all>,
 <mailto:svn-src-all-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 10 Jul 2014 21:46:57 -0000

Author: mjg
Date: Thu Jul 10 21:46:57 2014
New Revision: 268509
URL: http://svnweb.freebsd.org/changeset/base/268509

Log:
  Don't make a temporary copy of fixed sysctl strings.

Modified:
  head/sys/kern/kern_sysctl.c

Modified: head/sys/kern/kern_sysctl.c
==============================================================================
--- head/sys/kern/kern_sysctl.c	Thu Jul 10 21:11:48 2014	(r268508)
+++ head/sys/kern/kern_sysctl.c	Thu Jul 10 21:46:57 2014	(r268509)
@@ -1216,26 +1216,33 @@ int
 sysctl_handle_string(SYSCTL_HANDLER_ARGS)
 {
 	size_t outlen;
-	int error = 0;
+	int error = 0, ro_string = 0;
 
 	/*
 	 * A zero-length buffer indicates a fixed size read-only
 	 * string:
 	 */
-	if (arg2 == 0)
+	if (arg2 == 0) {
 		arg2 = strlen((char *)arg1) + 1;
+		ro_string = 1;
+	}
 
 	if (req->oldptr != NULL) {
 		char *tmparg;
 
-		/* try to make a coherent snapshot of the string */
-		tmparg = malloc(arg2, M_SYSCTLTMP, M_WAITOK);
-		memcpy(tmparg, arg1, arg2);
+		if (ro_string) {
+			tmparg = arg1;
+		} else {
+			/* try to make a coherent snapshot of the string */
+			tmparg = malloc(arg2, M_SYSCTLTMP, M_WAITOK);
+			memcpy(tmparg, arg1, arg2);
+		}
 
 		outlen = strnlen(tmparg, arg2 - 1) + 1;
 		error = SYSCTL_OUT(req, tmparg, outlen);
 
-		free(tmparg, M_SYSCTLTMP);
+		if (!ro_string)
+			free(tmparg, M_SYSCTLTMP);
 	} else {
 		outlen = strnlen((char *)arg1, arg2 - 1) + 1;
 		error = SYSCTL_OUT(req, NULL, outlen);