From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752016AbbCLSUI (ORCPT ); Thu, 12 Mar 2015 14:20:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45646 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751148AbbCLSUG (ORCPT ); Thu, 12 Mar 2015 14:20:06 -0400 Message-ID: <5501D8CF.7020204@redhat.com> Date: Thu, 12 Mar 2015 18:19:59 +0000 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Oleg Nesterov , Andy Lutomirski CC: Jan Kratochvil , Sergio Durigan Junior , GDB Patches , "linux-kernel@vger.kernel.org" Subject: Re: vvar, gup && coredump References: <878ufc9kau.fsf@redhat.com> <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> <20150312174653.GA13086@redhat.com> In-Reply-To: <20150312174653.GA13086@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/12/2015 05:46 PM, Oleg Nesterov wrote: > On 03/12, Oleg Nesterov wrote: >> >> Yes, this is true. OK, lets not dump it. > > OTOH. We can probably add ->access() into special_mapping_vmops, this > way __access_remote_vm() could work even if gup() fails ? > > Jan, Sergio. How much do we want do dump this area ? The change above > should be justified. Memory mappings that weren't touched since they were initially mapped can be retrieved from the program binary and the shared libraries, even if the core dump is moved to another machine. However, in vvar case, sounds like there's nowhere to read it from offline? In that case, it could be justified to dump it. Thanks, Pedro Alves