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=-2.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_MED, URIBL_BLOCKED,USER_AGENT_NEOMUTT 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 E40FAC32789 for ; Fri, 2 Nov 2018 15:25:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AC8662082E for ; Fri, 2 Nov 2018 15:25:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=shutemov-name.20150623.gappssmtp.com header.i=@shutemov-name.20150623.gappssmtp.com header.b="toM57DGu" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AC8662082E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=shutemov.name 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 S1727312AbeKCAcr (ORCPT ); Fri, 2 Nov 2018 20:32:47 -0400 Received: from mail-lj1-f195.google.com ([209.85.208.195]:40030 "EHLO mail-lj1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726016AbeKCAcr (ORCPT ); Fri, 2 Nov 2018 20:32:47 -0400 Received: by mail-lj1-f195.google.com with SMTP id t22-v6so2086833lji.7 for ; Fri, 02 Nov 2018 08:25:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=xw5nKTWQnFRX1MqZ0SNMxwfdIu2Jry3Kwo9Dls8r2DE=; b=toM57DGueAip1GtMfqJJcMt8UEgrNtRaH/IXcX57KQT5OTe0P0TTwDfWGQG45dxfXa n1+EKJVq1HvlVTliXyt4eUB14GEOIQSw8Xqr2mB0zI0UdYHcU9GqEq3puTYJQtNai7bk d9EXyl6gFnkobLYUJfzAv2DAJtvjb4pNBIDzcamknqD97B2T6bG/OtBvx74du1qmE8d3 lWPFWNR6Do764HqmnZbUS2+aXy2lXJ5KggcOfXEYQ5JvBOcY4Ot+FShE4fJPdG8Hjo2d D/wYVqzafYz5ave3G3Uo6p4lviXXmY28smpeXlmrkVw85p1GbquoZHKPFeHCAOba/q25 0xFA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=xw5nKTWQnFRX1MqZ0SNMxwfdIu2Jry3Kwo9Dls8r2DE=; b=RCbpACTDhJED5lq4NS2+/ld+xFJEEkNiwkjz4SPD19mdd4OMsrlXWl7amONNVrNiTa SlypB+tQzML/tOJ3GGy1Tun2ggdMcR7y9BwPW1RHpcPbq88g6ajgejACFy0008CAkjLC y729yuemvG4DS48iGSzbdrCHV8QUJN0865HkPUcg3v79/CLplwF7PzOsfLekz5LfnTNw kS6YtFJ5F6Aax26dE7QjNdARex0JZ7/WzsgYtvD3ivZNWceaCFqQpwNb+j27Zf70cPV2 wx3nIFQXAv1cDCHWTpbYgl+iStkrhMjCd0RJRZugnehW/GIeqMi6IG5vShsvlGO7zh4i jCVw== X-Gm-Message-State: AGRZ1gKed8TJyfdWdqI2ETYwpnS8Gai2lfaBFl4erc2YE9rR4EBwzbBO 1sSPYLW8M2wp8Vg9DKJ1T5/a9w== X-Google-Smtp-Source: AJdET5d7W7CVIm9DYEIO7n3de1nTGKVbNnNQNxF6ZVCuit3vs+HX2euUR1+neVuN47Yd8Lx6ogCgFQ== X-Received: by 2002:a2e:2909:: with SMTP id u9-v6mr7961419lje.28.1541172319110; Fri, 02 Nov 2018 08:25:19 -0700 (PDT) Received: from kshutemo-mobl1.localdomain (mm-83-111-44-37.mgts.dynamic.pppoe.byfly.by. [37.44.111.83]) by smtp.gmail.com with ESMTPSA id r199sm2602874lff.50.2018.11.02.08.25.18 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 02 Nov 2018 08:25:18 -0700 (PDT) Received: by kshutemo-mobl1.localdomain (Postfix, from userid 1000) id C25F230164F; Fri, 2 Nov 2018 18:25:16 +0300 (+03) Date: Fri, 2 Nov 2018 18:25:16 +0300 From: "Kirill A. Shutemov" To: Jann Horn Cc: Linus Torvalds , Will Deacon , Greg Kroah-Hartman , stable@vger.kernel.org, kernel list , Ingo Molnar , Peter Zijlstra , Linux-MM , Michal Hocko , Hugh Dickins Subject: Re: [PATCH] mremap: properly flush TLB before releasing the page Message-ID: <20181102152516.dkqpeubxh6c3phl2@kshutemo-mobl1> References: <1541164962-28533-1-git-send-email-will.deacon@arm.com> <20181102145638.gehn7eszv22lelh6@kshutemo-mobl1> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 02, 2018 at 04:00:17PM +0100, Jann Horn wrote: > On Fri, Nov 2, 2018 at 3:56 PM Kirill A. Shutemov wrote: > > On Fri, Nov 02, 2018 at 01:22:42PM +0000, Will Deacon wrote: > > > From: Linus Torvalds > > > > > > Commit eb66ae030829605d61fbef1909ce310e29f78821 upstream. > > > > I have never seen the original patch on mailing lists, so I'll reply to > > the backport. > > For context, the original bug report is public at > https://bugs.chromium.org/p/project-zero/issues/detail?id=1695 . Okay. I see. I wounder if it would be cheaper to fix this by taking i_mmap_lock_write() unconditionally in mremap() path rather than do a lot of flushing. We take the lock now only to remap to lower addresses. -- Kirill A. Shutemov