From owner-svn-src-all@freebsd.org  Sat Nov 11 21:50:37 2017
Return-Path: <owner-svn-src-all@freebsd.org>
Delivered-To: svn-src-all@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id 61958E4D522;
 Sat, 11 Nov 2017 21:50:37 +0000 (UTC) (envelope-from mjg@FreeBSD.org)
Received: from repo.freebsd.org (repo.freebsd.org
 [IPv6:2610:1c1:1:6068::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 2EB8C6FDDB;
 Sat, 11 Nov 2017 21:50:37 +0000 (UTC) (envelope-from mjg@FreeBSD.org)
Received: from repo.freebsd.org ([127.0.1.37])
 by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id vABLoaNX033504;
 Sat, 11 Nov 2017 21:50:36 GMT (envelope-from mjg@FreeBSD.org)
Received: (from mjg@localhost)
 by repo.freebsd.org (8.15.2/8.15.2/Submit) id vABLoaOl033503;
 Sat, 11 Nov 2017 21:50:36 GMT (envelope-from mjg@FreeBSD.org)
Message-Id: <201711112150.vABLoaOl033503@repo.freebsd.org>
X-Authentication-Warning: repo.freebsd.org: mjg set sender to mjg@FreeBSD.org
 using -f
From: Mateusz Guzik <mjg@FreeBSD.org>
Date: Sat, 11 Nov 2017 21:50:36 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-head@freebsd.org
Subject: svn commit: r325725 - head/sys/kern
X-SVN-Group: head
X-SVN-Commit-Author: mjg
X-SVN-Commit-Paths: head/sys/kern
X-SVN-Commit-Revision: 325725
X-SVN-Commit-Repository: base
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: 2.1.23
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: <https://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: <https://lists.freebsd.org/mailman/listinfo/svn-src-all>,
 <mailto:svn-src-all-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 11 Nov 2017 21:50:37 -0000

Author: mjg
Date: Sat Nov 11 21:50:36 2017
New Revision: 325725
URL: https://svnweb.freebsd.org/changeset/base/325725

Log:
  sysctl: try to avoid malloc in name2oid
  
  name2oid is called all the time and passed names are almost always very short
  (< 16 characters).

Modified:
  head/sys/kern/kern_sysctl.c

Modified: head/sys/kern/kern_sysctl.c
==============================================================================
--- head/sys/kern/kern_sysctl.c	Sat Nov 11 20:12:48 2017	(r325724)
+++ head/sys/kern/kern_sysctl.c	Sat Nov 11 21:50:36 2017	(r325725)
@@ -1209,17 +1209,21 @@ sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS)
 	int error, oid[CTL_MAXNAME], len = 0;
 	struct sysctl_oid *op = NULL;
 	struct rm_priotracker tracker;
+	char buf[32];
 
 	if (!req->newlen) 
 		return (ENOENT);
 	if (req->newlen >= MAXPATHLEN)	/* XXX arbitrary, undocumented */
 		return (ENAMETOOLONG);
 
-	p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK);
+	p = buf;
+	if (req->newlen >= sizeof(buf))
+		p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK);
 
 	error = SYSCTL_IN(req, p, req->newlen);
 	if (error) {
-		free(p, M_SYSCTL);
+		if (p != buf)
+			free(p, M_SYSCTL);
 		return (error);
 	}
 
@@ -1229,7 +1233,8 @@ sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS)
 	error = name2oid(p, oid, &len, &op);
 	SYSCTL_RUNLOCK(&tracker);
 
-	free(p, M_SYSCTL);
+	if (p != buf)
+		free(p, M_SYSCTL);
 
 	if (error)
 		return (error);