From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 5 Feb 2008 10:19:29 -0800 (PST) From: Christoph Lameter Subject: Re: [patch 1/6] mmu_notifier: Core code In-Reply-To: <20080205180557.GC29502@shadowen.org> Message-ID: References: <20080128202840.974253868@sgi.com> <20080128202923.609249585@sgi.com> <20080205180557.GC29502@shadowen.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Andy Whitcroft Cc: Andrea Arcangeli , Robin Holt , Avi Kivity , Izik Eidus , Nick Piggin , kvm-devel@lists.sourceforge.net, Benjamin Herrenschmidt , Peter Zijlstra , steiner@sgi.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, daniel.blueman@quadrics.com, Hugh Dickins List-ID: On Tue, 5 Feb 2008, Andy Whitcroft wrote: > > + if (unlikely(!hlist_empty(&mm->mmu_notifier.head))) { > > + rcu_read_lock(); > > + hlist_for_each_entry_safe_rcu(mn, n, t, > > + &mm->mmu_notifier.head, hlist) { > > + if (mn->ops->release) > > + mn->ops->release(mn, mm); > > Does this ->release actually release the 'nm' and its associated hlist? > I see in this thread that this ordering is deemed "use after free" which > implies so. Right that was fixed in a later release and discussed extensively later. See V5. > I am not sure it makes sense to add a _safe_rcu variant. As I understand > things an _safe variant is used where we are going to remove the current It was dropped in V5. -- 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/ . Don't email: email@kvack.org