From: Kinsbursky Stanislav <skinsbursky@openvz.org>
To: "akpm@linux-foundation.org" <akpm@linux-foundation.org>
Cc: "serge.hallyn@canonical.com" <serge.hallyn@canonical.com>,
"dhowells@redhat.com" <dhowells@redhat.com>,
"arnd@arndb.de" <arnd@arndb.de>,
"lucas.demarchi@profusion.mobi" <lucas.demarchi@profusion.mobi>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"criu@openvz.org" <criu@openvz.org>,
"mtk.manpages@gmail.com" <mtk.manpages@gmail.com>
Subject: Re: [CRIU] [PATCH v2 0/2] IPC: message queue checkpoint/restore - requested updates
Date: Mon, 23 Apr 2012 14:19:25 +0400 [thread overview]
Message-ID: <4F952CAD.5070405@openvz.org> (raw)
In-Reply-To: <20120416140235.653.36996.stgit@localhost6.localdomain6>
Hello, Andrew.
I'm very sorry, but a critical flaw has been found in this feature: copying of
kernel data to user is done under spinlock.
Since message queue size can be increased up to INT_MAX, then copying to
temporary kernel buffer while passing message queue in not a solution.
So, please, drop both patches (feature implementation and test).
Most probably Ill replace them with MSG_PEEK feature (the same logic, but only
for one message - like it's done for sockets).
--
Best regards,
Stanislav Kinsbursky
prev parent reply other threads:[~2012-04-23 10:19 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-16 14:05 [PATCH v2 0/2] IPC: message queue checkpoint/restore - requested updates Stanislav Kinsbursky
2012-04-16 14:06 ` [PATCH v2 1/2] IPC: message queue stealing feature introduced Stanislav Kinsbursky
2012-04-16 14:06 ` [PATCH v2 2/2] IPC: selftest tor new MSG_PEEK_ALL flag for msgrcv() Stanislav Kinsbursky
2012-04-16 22:11 ` Andrew Morton
2012-04-17 8:23 ` Stanislav Kinsbursky
2012-04-23 10:19 ` Kinsbursky Stanislav [this message]
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