Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755215AbYFEIxa (ORCPT ); Thu, 5 Jun 2008 04:53:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751461AbYFEIxX (ORCPT ); Thu, 5 Jun 2008 04:53:23 -0400 Received: from sacred.ru ([62.205.161.221]:53035 "EHLO sacred.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752040AbYFEIxW (ORCPT ); Thu, 5 Jun 2008 04:53:22 -0400 Message-ID: <4847A7BE.5010603@openvz.org> Date: Thu, 05 Jun 2008 12:45:50 +0400 From: Pavel Emelyanov User-Agent: Thunderbird 2.0.0.14 (X11/20080421) MIME-Version: 1.0 To: Andrew Morton CC: Linux Kernel Mailing List , Serge Hallyn Subject: [PATCH 2/2] devscgroup: make white list more compact in some cases Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-3.0 (sacred.ru [62.205.161.221]); Thu, 05 Jun 2008 12:48:06 +0400 (MSD) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2074 Lines: 68 Consider you added a 'c foo:bar r' permission to some cgroup and then (a bit later) 'c'foo:bar w' for it. After this you'll see a c foo:bar r c foo:bar w lines in a devices.list file. Another example - consider you added 10 'c foo:bar r' permissions to some cgroup (e.g. by mistake). After this you'll see 10 c foo:bar r lines in a list file. This is weird. This situation also has one more annoying consequence. Having many items in a white list makes permissions checking slower, sine it has to walk a longer list. The proposal is to merge permissions for items, that correspond to the same device. Signed-off-by: Pavel Emelyanov --- security/device_cgroup.c | 18 ++++++++++++++++-- 1 files changed, 16 insertions(+), 2 deletions(-) diff --git a/security/device_cgroup.c b/security/device_cgroup.c index f9941a7..baf3488 100644 --- a/security/device_cgroup.c +++ b/security/device_cgroup.c @@ -106,7 +106,7 @@ free_and_exit: static int dev_whitelist_add(struct dev_cgroup *dev_cgroup, struct dev_whitelist_item *wh) { - struct dev_whitelist_item *whcopy; + struct dev_whitelist_item *whcopy, *walk; whcopy = kmalloc(sizeof(*whcopy), GFP_KERNEL); if (!whcopy) @@ -114,7 +114,21 @@ static int dev_whitelist_add(struct dev_cgroup *dev_cgroup, memcpy(whcopy, wh, sizeof(*whcopy)); spin_lock(&dev_cgroup->lock); - list_add_tail(&whcopy->list, &dev_cgroup->whitelist); + list_for_each_entry(walk, &dev_cgroup->whitelist, list) { + if (walk->type != wh->type) + continue; + if (walk->major != wh->major) + continue; + if (walk->minor != wh->minor) + continue; + + walk->access |= wh->access; + kfree(whcopy); + whcopy = NULL; + } + + if (whcopy != NULL) + list_add_tail(&whcopy->list, &dev_cgroup->whitelist); spin_unlock(&dev_cgroup->lock); return 0; } -- 1.5.3.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/