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=-12.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 A458EC2B9F7 for ; Wed, 26 May 2021 09:47:33 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2CBC36142D for ; Wed, 26 May 2021 09:47:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2CBC36142D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B83216B0036; Wed, 26 May 2021 05:47:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B0BDA6B006E; Wed, 26 May 2021 05:47:32 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 95DD86B0070; Wed, 26 May 2021 05:47:32 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0231.hostedemail.com [216.40.44.231]) by kanga.kvack.org (Postfix) with ESMTP id 5FF616B0036 for ; Wed, 26 May 2021 05:47:32 -0400 (EDT) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 001B84FEC for ; Wed, 26 May 2021 09:47:31 +0000 (UTC) X-FDA: 78182904744.20.7137ED3 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by imf28.hostedemail.com (Postfix) with ESMTP id EFF0520007E0 for ; Wed, 26 May 2021 09:47:24 +0000 (UTC) Received: from imap.suse.de (imap-alt.suse-dmz.suse.de [192.168.254.47]) by smtp-out2.suse.de (Postfix) with ESMTP id 24CB71FD29; Wed, 26 May 2021 09:47:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1622022450; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=1I4Fgx3Wsu9b4i+qkfJ6NLcukv/nrkr5xfQ4pMZYpcM=; b=jPRSzya/SZPLGu40Y/Pn4aMJM6uQImJAsZ3cTRzh8tRnwE3Pw6drInbDphgqg4F+8ghy+3 Fe7uk+2A3BTtdCPZcWFLHs7WBHTLqQQbC1cqz1z7jxop481vQQSKiWu2cVon4urJXKjLV2 5DNss7gehP8SE3kkV0bVkIdzrgmKqfE= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1622022450; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=1I4Fgx3Wsu9b4i+qkfJ6NLcukv/nrkr5xfQ4pMZYpcM=; b=HdbQ0wDwwNSJckYD2D3ngt+tcvXWBB8NmdyXbdK9MySHHUQREbZ4xSMjpwuilsBpIu/mZg V61MUy/knevzRCAw== Received: from director2.suse.de (director2.suse-dmz.suse.de [192.168.254.72]) by imap.suse.de (Postfix) with ESMTPSA id 60ADD11A98; Wed, 26 May 2021 09:47:29 +0000 (UTC) Date: Wed, 26 May 2021 11:47:27 +0200 From: Oscar Salvador To: Naoya Horiguchi Cc: linux-mm@kvack.org, Tony Luck , Aili Yao , Andrew Morton , David Hildenbrand , Borislav Petkov , Andy Lutomirski , Naoya Horiguchi , Jue Wang , linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 1/3] mm/memory-failure: Use a mutex to avoid memory_failure() races Message-ID: <20210526094722.GA1656@linux> References: <20210521030156.2612074-1-nao.horiguchi@gmail.com> <20210521030156.2612074-2-nao.horiguchi@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210521030156.2612074-2-nao.horiguchi@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b="jPRSzya/"; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=HdbQ0wDw; dmarc=none; spf=pass (imf28.hostedemail.com: domain of osalvador@suse.de designates 195.135.220.29 as permitted sender) smtp.mailfrom=osalvador@suse.de X-Stat-Signature: o4tcmrw34bonwxu95zui6pr5cc18foin X-Rspamd-Queue-Id: EFF0520007E0 X-Rspamd-Server: rspam02 X-HE-Tag: 1622022444-191958 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, May 21, 2021 at 12:01:54PM +0900, Naoya Horiguchi wrote: > From: Tony Luck > > There can be races when multiple CPUs consume poison from the same > page. The first into memory_failure() atomically sets the HWPoison > page flag and begins hunting for tasks that map this page. Eventually > it invalidates those mappings and may send a SIGBUS to the affected > tasks. > > But while all that work is going on, other CPUs see a "success" > return code from memory_failure() and so they believe the error > has been handled and continue executing. > > Fix by wrapping most of the internal parts of memory_failure() in > a mutex. > > Signed-off-by: Tony Luck > Signed-off-by: Naoya Horiguchi > Reviewed-by: Borislav Petkov Reviewed-by: Oscar Salvador -- Oscar Salvador SUSE L3