From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx145.postini.com [74.125.245.145]) by kanga.kvack.org (Postfix) with SMTP id 3BBFF6B0044 for ; Tue, 3 Apr 2012 14:16:50 -0400 (EDT) Received: from /spool/local by e37.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 3 Apr 2012 12:16:49 -0600 Received: from d03relay01.boulder.ibm.com (d03relay01.boulder.ibm.com [9.17.195.226]) by d03dlp03.boulder.ibm.com (Postfix) with ESMTP id C746419D804A for ; Tue, 3 Apr 2012 12:16:38 -0600 (MDT) Received: from d03av04.boulder.ibm.com (d03av04.boulder.ibm.com [9.17.195.170]) by d03relay01.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q33IGZ8i057478 for ; Tue, 3 Apr 2012 12:16:39 -0600 Received: from d03av04.boulder.ibm.com (loopback [127.0.0.1]) by d03av04.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q33IGWQN030073 for ; Tue, 3 Apr 2012 12:16:33 -0600 Date: Tue, 3 Apr 2012 11:16:31 -0700 From: Matt Helsley Subject: Re: [PATCH 6/7] mm: kill vma flag VM_EXECUTABLE Message-ID: <20120403181631.GD32299@count0.beaverton.ibm.com> References: <20120331091049.19373.28994.stgit@zurg> <20120331092929.19920.54540.stgit@zurg> <20120331201324.GA17565@redhat.com> <20120402230423.GB32299@count0.beaverton.ibm.com> <4F7A863C.5020407@openvz.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4F7A863C.5020407@openvz.org> Sender: owner-linux-mm@kvack.org List-ID: To: Konstantin Khlebnikov Cc: Matt Helsley , 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 On Tue, Apr 03, 2012 at 09:10:20AM +0400, Konstantin Khlebnikov wrote: > 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. Doesn't that break the semantics of the kernel ABI? Cheers, -Matt Helsley -- 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