Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752941AbXKBGal (ORCPT ); Fri, 2 Nov 2007 02:30:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753325AbXKBGaT (ORCPT ); Fri, 2 Nov 2007 02:30:19 -0400 Received: from ns2.suse.de ([195.135.220.15]:52313 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752197AbXKBGaN (ORCPT ); Fri, 2 Nov 2007 02:30:13 -0400 Date: Fri, 2 Nov 2007 07:30:11 +0100 From: Nick Piggin To: Linus Torvalds Cc: Duane Griffin , linux-kernel Mailing List , stable@kernel.org, Hugh Dickins Subject: Re: 2.6.23 regression: accessing invalid mmap'ed memory from gdb causes unkillable spinning Message-ID: <20071102063011.GB20967@wotan.suse.de> References: <20071031151934.GA19211@wotan.suse.de> <20071031225541.GA28552@wotan.suse.de> <20071101023758.GA30613@wotan.suse.de> <20071101154705.GA745@wotan.suse.de> <20071101235644.GA20144@wotan.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1043 Lines: 23 On Thu, Nov 01, 2007 at 06:17:42PM -0700, Linus Torvalds wrote: > > > On Fri, 2 Nov 2007, Nick Piggin wrote: > > > > But we do want to allow forced COW faults for MAP_PRIVATE mappings. gdb > > uses this for inserting breakpoints (but fortunately, a COW page in a > > MAP_PRIVATE mapping is a much more natural thing for the VM). > > Yes, I phrased that badly. I meant that I'd be happier if we got rid of > VM_MAYSHARE entirely, and just used VM_SHARED. I thought we already made > them always be the same (and any VM_MAYSHARE use is historical). Oh yeah, I think it would probably be clearer to use VM_SHARED == MAP_SHARED, and test the write permission explicitly. Though there could be something I missed that makes it not as easy as it sounds... probably something best left for Hugh ;) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/