From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753955AbeDRLzt (ORCPT ); Wed, 18 Apr 2018 07:55:49 -0400 Received: from mx2.suse.de ([195.135.220.15]:55041 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753937AbeDRLzs (ORCPT ); Wed, 18 Apr 2018 07:55:48 -0400 Date: Wed, 18 Apr 2018 13:55:46 +0200 From: Michal Hocko To: Tetsuo Handa Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] fs, elf: drop MAP_FIXED usage from elf_map Message-ID: <20180418115546.GZ17484@dhcp22.suse.cz> References: <20171213092550.2774-1-mhocko@kernel.org> <20171213092550.2774-3-mhocko@kernel.org> <0b5c541a-91ee-220b-3196-f64264f9f0bc@I-love.SAKURA.ne.jp> <20180418113301.GY17484@dhcp22.suse.cz> <201804182043.JFH90161.LStOOMFFOJQHVF@I-love.SAKURA.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201804182043.JFH90161.LStOOMFFOJQHVF@I-love.SAKURA.ne.jp> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 18-04-18 20:43:11, Tetsuo Handa wrote: > Michal Hocko wrote: > > > Don't complain if IS_ERR_VALUE(), > > > > this is simply wrong. We do want to warn on the failure because this is > > when the actual clash happens. We should just warn on EEXIST. > > >From 25442cdd31aa5cc8522923a0153a77dfd2ebc832 Mon Sep 17 00:00:00 2001 > From: Tetsuo Handa > Date: Wed, 18 Apr 2018 20:38:15 +0900 > Subject: [PATCH] fs, elf: don't complain MAP_FIXED_NOREPLACE unless -EEXIST > error. > > Commit 4ed28639519c7bad ("fs, elf: drop MAP_FIXED usage from elf_map") is > printing spurious messages under memory pressure due to map_addr == -ENOMEM. > > 9794 (a.out): Uhuuh, elf segment at 00007f2e34738000(fffffffffffffff4) requested but the memory is mapped already > 14104 (a.out): Uhuuh, elf segment at 00007f34fd76c000(fffffffffffffff4) requested but the memory is mapped already > 16843 (a.out): Uhuuh, elf segment at 00007f930ecc7000(fffffffffffffff4) requested but the memory is mapped already > > Complain only if -EEXIST, and use %px for printing the address. Yes this is better. But... [...] > - if ((type & MAP_FIXED_NOREPLACE) && BAD_ADDR(map_addr)) > - pr_info("%d (%s): Uhuuh, elf segment at %p requested but the memory is mapped already\n", > - task_pid_nr(current), current->comm, > - (void *)addr); > + if ((type & MAP_FIXED_NOREPLACE) && map_addr == -EEXIST) ... please use PTR_ERR(map_addr) == -EEXIST then you can add Acked-by: Michal Hocko > + pr_info("%d (%s): Uhuuh, elf segment at %px requested but the memory is mapped already\n", > + task_pid_nr(current), current->comm, (void *)addr); > > return(map_addr); > } > -- > 1.8.3.1 -- Michal Hocko SUSE Labs