From mboxrd@z Thu Jan  1 00:00:00 1970
From: Martin Lucina <martin@lucina.net>
Subject: Re: [PATCH] xenconsole: Ensure exclusive access to
 console using locks
Date: Fri, 24 Jul 2015 15:42:22 +0200
Message-ID: <20150724134222.GF25338@nodbug.lucina.net>
References: <1437738262.24746.79.camel@citrix.com>
	<1437742310-14193-1-git-send-email-martin@lucina.net>
	<21938.15968.711376.627272@mariner.uk.xensource.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
Return-path: <xen-devel-bounces@lists.xen.org>
Received: from mail6.bemta5.messagelabs.com ([195.245.231.135])
	by lists.xen.org with esmtp (Exim 4.72)
	(envelope-from <martin@lucina.net>) id 1ZIdEy-00019i-Qu
	for xen-devel@lists.xenproject.org; Fri, 24 Jul 2015 13:42:20 +0000
Content-Disposition: inline
In-Reply-To: <21938.15968.711376.627272@mariner.uk.xensource.com>
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Sender: xen-devel-bounces@lists.xen.org
Errors-To: xen-devel-bounces@lists.xen.org
To: Ian Jackson <Ian.Jackson@eu.citrix.com>
Cc: xen-devel@lists.xenproject.org, Wei Liu <wei.liu2@citrix.com>, Ian Campbell <ian.campbell@citrix.com>, Stefano Stabellini <stefano.stabellini@eu.citrix.com>
List-Id: xen-devel@lists.xenproject.org

On Friday, 24.07.2015 at=A014:32, Ian Jackson wrote:
> > +static void console_lock(int domid)
> > +{
> > +	lockfile =3D malloc(PATH_MAX);
> > +	if (lockfile =3D=3D NULL)
> > +		err(ENOMEM, "malloc");
> > +	snprintf(lockfile, PATH_MAX - 1, "%s/xenconsole.%d", XEN_LOCK_DIR, do=
mid);
> =

> Why not use asprintf ?

asprintf is a GNU/BSD extension, not available on e.g. Solaris. Do we care
about that?

> You should use the same recipe as with-lock-ex (from chiark-utils)
> =

>   http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=3Dchiark-utils.git;a=
=3Dblob;f=3Dcprogs/with-lock-ex.c;h=3D1850d1f0283bd61fc1da12458cba7ec0a227c=
572;hb=3DHEAD
>   =

> (which we also use in tools/hotplug/Linux/locking.sh and
> tools/libxl/libxl_internal.c:libxl__lock_domain_userdata)

Thanks for the pointers, I'll use that strategy.

Martin