Date: Tue, 13 Nov 2012 19:53:13 +0400
From: Cyrill Gorcunov <gorcunov@openvz.org>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>, Al Viro <viro@ZenIV.linux.org.uk>,
        Alexey Dobriyan <adobriyan@gmail.com>,
        James Bottomley <jbottomley@parallels.com>,
        "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
        Matthew Helsley <matt.helsley@gmail.com>,
        "J. Bruce Fields" <bfields@fieldses.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org
Subject: Re: + fs-epoll-add-procfs-fdinfo-helper.patch added to -mm tree
Message-ID: <20121113155313.GU6511@moon>
References: <20121113145050.GA13691@redhat.com>
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On Tue, Nov 13, 2012 at 03:50:50PM +0100, Oleg Nesterov wrote:
> This doesn't look right.
> 
> The problem is, the current locking is broken, ->siglock can not serialize
> ->sigmask changes. Just suppose the the child inherits sigfd from parent
> and they both do sys_signalfd4() at the same time.
> 
> Nothing really bad can happen, that is why nobody bothers to fix this.
> But this patch makes the thing worse, write_seqcount_begin() must be
> serialized correctly.

Thanks a lot, Oleg! I'll update.
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