From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B0BC3C4321D for ; Thu, 23 Aug 2018 08:57:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6EC4220847 for ; Thu, 23 Aug 2018 08:57:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6EC4220847 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728312AbeHWMZ6 (ORCPT ); Thu, 23 Aug 2018 08:25:58 -0400 Received: from mx2.suse.de ([195.135.220.15]:38050 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726966AbeHWMZ5 (ORCPT ); Thu, 23 Aug 2018 08:25:57 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 38C8EAED6; Thu, 23 Aug 2018 08:57:15 +0000 (UTC) Date: Thu, 23 Aug 2018 10:57:14 +0200 From: Michal Hocko To: Nadav Amit Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , stable@vger.kernel.org Subject: Re: [PATCH] mm: respect arch_dup_mmap() return value Message-ID: <20180823085714.GY29735@dhcp22.suse.cz> References: <20180823051229.211856-1-namit@vmware.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180823051229.211856-1-namit@vmware.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 22-08-18 22:12:29, Nadav Amit wrote: > Commit d70f2a14b72a4 ("include/linux/sched/mm.h: uninline > mmdrop_async(), etc") ignored the return value of arch_dup_mmap(). As a > result, on x86, a failure to duplicate the LDT (e.g., due to memory > allocation error), would leave the duplicated memory mapping in an > inconsistent state. > > Fix by regarding the return value, as it was before the change. Ohh, well spotted! I have a vague recollection I didn't really like the patch. For other reasons. I didn't get to review it properly back then because I didn't have much time and I didn't have a high motivation because I simple disagreed with the patch. > Fixes: d70f2a14b72a4 ("include/linux/sched/mm.h: uninline mmdrop_async(), etc") > Cc: Andrew Morton > Cc: stable@vger.kernel.org > Signed-off-by: Nadav Amit Acked-by: Michal Hocko Thanks! > --- > kernel/fork.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/kernel/fork.c b/kernel/fork.c > index 1b27babc4c78..4527d1d331de 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -549,8 +549,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm, > goto out; > } > /* a new mm has just been created */ > - arch_dup_mmap(oldmm, mm); > - retval = 0; > + retval = arch_dup_mmap(oldmm, mm); > out: > up_write(&mm->mmap_sem); > flush_tlb_mm(oldmm); > -- > 2.17.1 > -- Michal Hocko SUSE Labs