From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: linux-next: manual merge of the selinux tree Date: Tue, 8 Jul 2008 01:49:50 -0700 Message-ID: <20080708014950.1caa8a64.akpm@linux-foundation.org> References: <20080707225130.ca52d527.sfr@canb.auug.org.au> <1215442054.27975.85.camel@moss-spartans.epoch.ncsc.mil> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:33365 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751564AbYGHI4V (ORCPT ); Tue, 8 Jul 2008 04:56:21 -0400 In-Reply-To: <1215442054.27975.85.camel@moss-spartans.epoch.ncsc.mil> Sender: linux-next-owner@vger.kernel.org List-ID: To: Stephen Smalley Cc: James Morris , Stephen Rothwell , Eric Paris , Paul Moore , linux-next@vger.kernel.org On Mon, 07 Jul 2008 10:47:34 -0400 Stephen Smalley wrote: > > On Tue, 2008-07-08 at 00:43 +1000, James Morris wrote: > > On Mon, 7 Jul 2008, Stephen Rothwell wrote: > > > > > Hi all, > > > > > > Today's linux-next merge of the selinux tree got a conflict in > > > fs/proc/task_mmu.c between commit > > > 5d7e0d2bd98ef4f5a16ac9da1987ae655368dd6a ("Fix pagemap_read() use of > > > struct mm_walk") from Linus' tree and commit > > > ca9b1a1413bac6ea5e5c8cb81044a39bdb3b4bc8 ("Security: split proc ptrace > > > checking into read vs. attach") from the selinux tree. > > > > > > The former removed some of the code that the latter changed. It is > > > probably worth a check on the code in pagemap_read to make sure I got it > > > right. > > > > I couldn't locate your updated version, but have resolved it in my own > > tree (which is being rebased). > > > > One thing we need to understand is why there were two separate > > ptrace_may_attach() calls in the earlier version of pagemap_read(). > > It could sleep in between the two calls. > This is basically meaningless? Other threads could be running, accessing this mm_struct. Other processes can be doing stuff. Preemption can happen. Are we missing some locking here?