Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757969AbeAHWM7 (ORCPT + 1 other); Mon, 8 Jan 2018 17:12:59 -0500 Received: from ozlabs.org ([103.22.144.67]:55347 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757862AbeAHWM4 (ORCPT ); Mon, 8 Jan 2018 17:12:56 -0500 From: Michael Ellerman To: Anshuman Khandual , Michal Hocko , Anshuman Khandual Cc: akpm@linux-foundation.org, mm-commits@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-next@vger.kernel.org, sfr@canb.auug.org.au, broonie@kernel.org Subject: Re: ppc elf_map breakage with MAP_FIXED_NOREPLACE In-Reply-To: <7a44f42e-39d0-1c4b-19e0-7df1b0842c18@linux.vnet.ibm.com> References: <5a4ec4bc.u5I/HzCSE6TLVn02%akpm@linux-foundation.org> <7e35e16a-d71c-2ec8-03ed-b07c2af562f8@linux.vnet.ibm.com> <20180105084631.GG2801@dhcp22.suse.cz> <20180107090229.GB24862@dhcp22.suse.cz> <87mv1phptq.fsf@concordia.ellerman.id.au> <7a44f42e-39d0-1c4b-19e0-7df1b0842c18@linux.vnet.ibm.com> Date: Tue, 09 Jan 2018 09:12:49 +1100 Message-ID: <87tvvw80f2.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: Anshuman Khandual writes: > On 01/07/2018 04:56 PM, Michael Ellerman wrote: >> Michal Hocko writes: >> >>> On Sun 07-01-18 12:19:32, Anshuman Khandual wrote: >>>> On 01/05/2018 02:16 PM, Michal Hocko wrote: >>> [...] >>>>> Could you give us more information about the failure please. Debugging >>>>> patch from http://lkml.kernel.org/r/20171218091302.GL16951@dhcp22.suse.cz >>>>> should help to see what is the clashing VMA. >>>> Seems like its re-requesting the same mapping again. >>> It always seems to be the same mapping which is a bit strange as we >>> have multiple binaries here. Are these binaries any special? Does this >>> happen to all bianries (except for init which has obviously started >>> successfully)? Could you add an additional debugging (at the do_mmap >>> layer) to see who is requesting the mapping for the first time? >>> >>>> [ 23.423642] 9148 (sed): Uhuuh, elf segment at 0000000010030000 requested but the memory is mapped already >>>> [ 23.423706] requested [10030000, 10040000] mapped [10030000, 10040000] 100073 anon >>> I also find it a bit unexpected that this is an anonymous mapping >>> because the elf loader should always map a file backed one. >> Anshuman what machine is this on, and what distro and toolchain is it running? >> >> I don't see this on any of my machines, so I wonder if this is >> toolchain/distro specific. > > POWER9, RHEL 7.4, gcc (GCC) 4.8.5 20150623, GNU Make 3.82 etc. So what does readelf -a of /bin/sed look like? cheers