From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934083Ab2C3K1C (ORCPT ); Fri, 30 Mar 2012 06:27:02 -0400 Received: from aldebaran.gro-tsen.net ([88.191.60.176]:40558 "EHLO aldebaran.gro-tsen.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933663Ab2C3K05 (ORCPT ); Fri, 30 Mar 2012 06:26:57 -0400 X-Greylist: delayed 331 seconds by postgrey-1.27 at vger.kernel.org; Fri, 30 Mar 2012 06:26:56 EDT Date: Fri, 30 Mar 2012 12:21:21 +0200 From: David Madore To: Linux Kernel Mailing-List Subject: since when does linkat() on deleted /proc/$PID/fd/$num return ENOENT ? Message-ID: <20120330102121.GA5999@aldebaran.gro-tsen.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It used to be the case (last time I checked was around late 2008 or early 2009) that deleted entries from /proc/$PID/fd/ could be linked back to the filesystem by using linkat(,,,,AT_SYMLINK_FOLLOW). Now this just returns ENOENT. I'd like to understand when, how and why this change took place. What commit introduced it and was it a deliberate move (e.g., because the feature was a security issue of itself, or came into conflict with something else) or was it accidental? Does it depend on the /proc filesystem itself or on the target filesystem where the deleted file used to reside? (There's a Reddit thread, , where some people are reporting ENOENT on 2.6.27 or perhaps even 2.6.26, which helps but a bound on the change.) (See also this thread: , where the question is not answered, however.) -- David A. Madore ( http://www.madore.org/~david/ )