From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx125.postini.com [74.125.245.125]) by kanga.kvack.org (Postfix) with SMTP id 17DE46B0092 for ; Tue, 3 Apr 2012 01:10:25 -0400 (EDT) Received: by bkwq16 with SMTP id q16so3829956bkw.14 for ; Mon, 02 Apr 2012 22:10:23 -0700 (PDT) Message-ID: <4F7A863C.5020407@openvz.org> Date: Tue, 03 Apr 2012 09:10:20 +0400 From: Konstantin Khlebnikov MIME-Version: 1.0 Subject: Re: [PATCH 6/7] mm: kill vma flag VM_EXECUTABLE References: <20120331091049.19373.28994.stgit@zurg> <20120331092929.19920.54540.stgit@zurg> <20120331201324.GA17565@redhat.com> <20120402230423.GB32299@count0.beaverton.ibm.com> In-Reply-To: <20120402230423.GB32299@count0.beaverton.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Matt Helsley Cc: Oleg Nesterov , "linux-mm@kvack.org" , Andrew Morton , "linux-kernel@vger.kernel.org" , Eric Paris , "linux-security-module@vger.kernel.org" , "oprofile-list@lists.sf.net" , Linus Torvalds , Al Viro , Cyrill Gorcunov Matt Helsley wrote: > On Sat, Mar 31, 2012 at 10:13:24PM +0200, Oleg Nesterov wrote: >> On 03/31, Konstantin Khlebnikov wrote: >>> >>> comment from v2.6.25-6245-g925d1c4 ("procfs task exe symlink"), >>> where all this stuff was introduced: >>> >>>> ... >>>> This avoids pinning the mounted filesystem. >>> >>> So, this logic is hooked into every file mmap/unmmap and vma split/merge just to >>> fix some hypothetical pinning fs from umounting by mm which already unmapped all >>> its executable files, but still alive. Does anyone know any real world example? >> >> This is the question to Matt. > > This is where I got the scenario: > > https://lkml.org/lkml/2007/7/12/398 Cyrill Gogcunov's patch "c/r: prctl: add ability to set new mm_struct::exe_file" gives userspace ability to unpin vfsmount explicitly. https://lkml.org/lkml/2012/3/16/449 > > Cheers, > -Matt Helsley > > PS: I seem to keep coming back to this so I hope folks don't mind if I leave > some more references to make (re)searching this topic easier: > > Thread with Cyrill Gorcunov discussing c/r of symlink: > https://lkml.org/lkml/2012/3/16/448 > > Thread with Oleg Nesterov re: cleanups: > https://lkml.org/lkml/2012/3/5/240 > > Thread with Alexey Dobriyan re: cleanups: > https://lkml.org/lkml/2009/6/4/625 > > mainline commit 925d1c401fa6cfd0df5d2e37da8981494ccdec07 > Date: Tue Apr 29 01:01:36 2008 -0700 > > procfs task exe symlink > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org