From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753833AbeDRLnV (ORCPT ); Wed, 18 Apr 2018 07:43:21 -0400 Received: from www262.sakura.ne.jp ([202.181.97.72]:14267 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753405AbeDRLnT (ORCPT ); Wed, 18 Apr 2018 07:43:19 -0400 To: mhocko@kernel.org 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 From: Tetsuo Handa 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> In-Reply-To: <20180418113301.GY17484@dhcp22.suse.cz> Message-Id: <201804182043.JFH90161.LStOOMFFOJQHVF@I-love.SAKURA.ne.jp> X-Mailer: Winbiff [Version 2.51 PL2] X-Accept-Language: ja,en,zh Date: Wed, 18 Apr 2018 20:43:11 +0900 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Signed-off-by: Tetsuo Handa Cc: Michal Hocko Cc: Andrei Vagin Cc: Khalid Aziz Cc: Michael Ellerman Cc: Kees Cook Cc: Abdul Haleem Cc: Joel Stanley Cc: Anshuman Khandual --- fs/binfmt_elf.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 41e0418..96615d9 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -377,10 +377,9 @@ static unsigned long elf_map(struct file *filep, unsigned long addr, } else map_addr = vm_mmap(filep, addr, size, prot, type, off); - 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) + 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