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=-12.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, 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 52299C433DB for ; Fri, 8 Jan 2021 23:39:53 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BB73F20786 for ; Fri, 8 Jan 2021 23:39:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BB73F20786 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0F5418D01C2; Fri, 8 Jan 2021 18:39:52 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0A59D8D01B7; Fri, 8 Jan 2021 18:39:52 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EAF978D01C2; Fri, 8 Jan 2021 18:39:51 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0033.hostedemail.com [216.40.44.33]) by kanga.kvack.org (Postfix) with ESMTP id D22CE8D01B7 for ; Fri, 8 Jan 2021 18:39:51 -0500 (EST) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 9A89F181AEF2A for ; Fri, 8 Jan 2021 23:39:51 +0000 (UTC) X-FDA: 77684227782.27.voice32_6308b3d274f6 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin27.hostedemail.com (Postfix) with ESMTP id 8078D3D663 for ; Fri, 8 Jan 2021 23:39:51 +0000 (UTC) X-HE-Tag: voice32_6308b3d274f6 X-Filterd-Recvd-Size: 2808 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) by imf35.hostedemail.com (Postfix) with ESMTP for ; Fri, 8 Jan 2021 23:39:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1610149190; h=from:from:reply-to:subject:subject: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=o+/HDfNx715tlUSpPNBNlGjDUHVImncoNqnzgPVg4XM=; b=LY8m4DATROpyLjgfon7IaSbDnXx6YQGU+h28Q5vBak1sOGruw4D2D53g/q0b+THjH1v4UX zbuuMh4RAIpG8kPwgKFih96WCIY6F2LRACwlUeTWfdrixwAw3GrWo5vSQ6Jx4oegeOcBiy 6UZ2Et0haYgSccfAJpr5SOj6TgpUCDA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-414-8GBRF_-gM7ys2yzfyiPmgQ-1; Fri, 08 Jan 2021 18:39:48 -0500 X-MC-Unique: 8GBRF_-gM7ys2yzfyiPmgQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 139AB801817; Fri, 8 Jan 2021 23:39:47 +0000 (UTC) Received: from mail (ovpn-112-222.rdu2.redhat.com [10.10.112.222]) by smtp.corp.redhat.com (Postfix) with ESMTPS id EE856709A4; Fri, 8 Jan 2021 23:39:43 +0000 (UTC) Date: Fri, 8 Jan 2021 18:39:43 -0500 From: Andrea Arcangeli To: Andy Lutomirski Cc: x86@kernel.org, LKML , Linux-MM , Jason Gunthorpe , Linus Torvalds , Matthew Wilcox , Jann Horn , Jan Kara , Yu Zhao , Peter Xu Subject: Re: [PATCH] x86/vm86/32: Remove VM86_SCREEN_BITMAP support Message-ID: References: <3d34069ab2d249d866ea1d18a47e4170dbfb5982.1610132102.git.luto@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3d34069ab2d249d866ea1d18a47e4170dbfb5982.1610132102.git.luto@kernel.org> User-Agent: Mutt/2.0.4 (2020-12-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 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, Jan 08, 2021 at 10:55:05AM -0800, Andy Lutomirski wrote: > The implementation was rather buggy. It unconditionally marked PTEs > released the mmap lock before flushing the TLB, which could allow a racing > CoW operation to falsely believe that the underlying memory was not > writable. > > I can't find any users at all of this mechanism, so just remove it. Reviewed-by: Andrea Arcangeli