From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with ESMTP id 28E688D0039 for ; Tue, 15 Mar 2011 15:28:52 -0400 (EDT) Received: from canuck.infradead.org ([2001:4978:20e::1]) by bombadil.infradead.org with esmtps (Exim 4.72 #1 (Red Hat Linux)) id 1PzZvF-0007Ee-58 for linux-mm@kvack.org; Tue, 15 Mar 2011 19:28:49 +0000 Received: from j77219.upc-j.chello.nl ([24.132.77.219] helo=dyad.programming.kicks-ass.net) by canuck.infradead.org with esmtpsa (Exim 4.72 #1 (Red Hat Linux)) id 1PzZvA-0004Ss-2k for linux-mm@kvack.org; Tue, 15 Mar 2011 19:28:44 +0000 Subject: Re: [PATCH v2 2.6.38-rc8-tip 7/20] 7: uprobes: store/restore original instruction. From: Peter Zijlstra In-Reply-To: <20110315185841.GH3410@balbir.in.ibm.com> References: <20110314133403.27435.7901.sendpatchset@localhost6.localdomain6> <20110314133522.27435.45121.sendpatchset@localhost6.localdomain6> <20110314180914.GA18855@fibrous.localdomain> <20110315092247.GW24254@linux.vnet.ibm.com> <1300211862.2203.302.camel@twins> <20110315185841.GH3410@balbir.in.ibm.com> Content-Type: text/plain; charset="UTF-8" Date: Tue, 15 Mar 2011 20:30:32 +0100 Message-ID: <1300217432.2250.0.camel@laptop> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: balbir@linux.vnet.ibm.com Cc: Srikar Dronamraju , Stephen Wilson , Ingo Molnar , Steven Rostedt , Linux-mm , Arnaldo Carvalho de Melo , Linus Torvalds , Ananth N Mavinakayanahalli , Christoph Hellwig , Andi Kleen , Masami Hiramatsu , Oleg Nesterov , LKML , Jim Keniston , Roland McGrath , SystemTap , Andrew Morton , "Paul E. McKenney" On Wed, 2011-03-16 at 00:28 +0530, Balbir Singh wrote: > > mm->owner should be under rcu_read_lock, unless the task is exiting > and mm_count is 1. mm->owner is updated under task_lock(). > > > Also, the assignments in kernel/fork.c and kernel/exit.c don't use > > rcu_assign_pointer() and therefore lack the needed write barrier. > > > > Those are paths when the only context using the mm->owner is single > > > Git blames Balbir for this. > > I accept the blame and am willing to fix anything incorrect found in > the code. :-), ok sounds right, just wasn't entirely obvious when having a quick look. -- 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