From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 111294 invoked by alias); 12 Mar 2015 18:04:24 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 111181 invoked by uid 89); 12 Mar 2015 18:04:23 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-3.9 required=5.0 tests=AWL,BAYES_00,SPF_HELO_PASS,SPF_PASS,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Thu, 12 Mar 2015 18:04:22 +0000 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t2CI4IlK010824 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 12 Mar 2015 14:04:18 -0400 Received: from tranklukator.brq.redhat.com (dhcp-1-208.brq.redhat.com [10.34.1.208]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with SMTP id t2CI4FxP019158; Thu, 12 Mar 2015 14:04:16 -0400 Received: by tranklukator.brq.redhat.com (nbSMTP-1.00) for uid 500 oleg@redhat.com; Thu, 12 Mar 2015 19:02:31 +0100 (CET) Date: Thu, 12 Mar 2015 18:04:00 -0000 From: Oleg Nesterov To: Sergio Durigan Junior Cc: Andy Lutomirski , Jan Kratochvil , GDB Patches , Pedro Alves , "linux-kernel@vger.kernel.org" Subject: Re: vvar, gup && coredump Message-ID: <20150312180229.GA13711@redhat.com> References: <20150305154827.GA9441@host1.jankratochvil.net> <87zj7r5fpz.fsf@redhat.com> <20150305205744.GA13165@host1.jankratochvil.net> <20150311200052.GA22654@redhat.com> <20150312143438.GA4338@redhat.com> <20150312165423.GA10073@redhat.com> <20150312173901.GA12225@redhat.com> <874mpqp0sm.fsf@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <874mpqp0sm.fsf@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-SW-Source: 2015-03/txt/msg00363.txt.bz2 On 03/12, Sergio Durigan Junior wrote: > > On Thursday, March 12 2015, Oleg Nesterov wrote: > > >> gdb will still need changes, though, right? > > > > This is up to gdb developers. To me, it should simply skip this > > VM_DONTDUMP vma. > > If I understood this discussion correctly (and thanks Andy and Oleg for, > *ahem*, dumping all this useful information for us!), GDB will not need > modifications in the Linux kernel in this area. In fact, my patch > already implements the "ignore VM_DONTDUMP mappings" part, so we're > pretty much covered. OK, thanks. And it seems that we all agree that the kernel should not dump this vma too. Could you confirm that this is fine from gdb pov just in case? However. Even if we do not want it in the coredump, this can confuse gdb users which might want to read this memory during debugging. So perhaps we still can add ->access() to "fix" PTRACE_PEEK/access_remote_vm later. But I see another email from Andy, so lets forget about this for now. Oleg.