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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 610D7C54E58 for ; Tue, 26 Mar 2024 06:04:56 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E23816B007B; Tue, 26 Mar 2024 02:04:55 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DD38E6B0082; Tue, 26 Mar 2024 02:04:55 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CC1DA6B0083; Tue, 26 Mar 2024 02:04:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id BC5EF6B007B for ; Tue, 26 Mar 2024 02:04:55 -0400 (EDT) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 3FA851408E3 for ; Tue, 26 Mar 2024 06:04:55 +0000 (UTC) X-FDA: 81938151750.07.279D527 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf04.hostedemail.com (Postfix) with ESMTP id 56EB440009 for ; Tue, 26 Mar 2024 06:04:53 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf04.hostedemail.com: domain of hch@lst.de designates 213.95.11.211 as permitted sender) smtp.mailfrom=hch@lst.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1711433093; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vdpzNvpgrUvzynb8ah5hA/QhXUMLO+Qza1rHIkBqo8o=; b=cW/CIlcHT+OG8D3OHSd6qRJTz4u4IBam66XT4Y3gCRy8iXwqiHAuK/yrtgFj132eHW2t/6 J2Ak7pD2G3hQISsaXl7N8RGFakkWdd/5Z88aOEtjlOLYUZS+sxSD070+fb5nIToKgg9Qzk n0JYENMet949p/k9L2QdXov3L9nbc/I= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf04.hostedemail.com: domain of hch@lst.de designates 213.95.11.211 as permitted sender) smtp.mailfrom=hch@lst.de ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1711433093; a=rsa-sha256; cv=none; b=7QVDyKE2foGb6ydEZB/E+MBM2CmpCxyzIumVIrDPoUDxEPY/IGX1B7KWC8ReFvfefP0RYY SOkfoovRSge7WAr79nKxyBNUR1QYR6QjqevjEVEIwxOw+jkKvjgr+rsYxp4ppJsjb3TbOI RdKL3cEmvB86YPco0LQ/roF4eqLJjkk= Received: by verein.lst.de (Postfix, from userid 2407) id 1FB1A68D37; Tue, 26 Mar 2024 07:04:48 +0100 (CET) Date: Tue, 26 Mar 2024 07:04:47 +0100 From: Christoph Hellwig To: David Hildenbrand Cc: Christoph Hellwig , Andrew Morton , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Fei Li , x86@kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 1/3] virt: acrn: stop using follow_pfn Message-ID: <20240326060447.GA7108@lst.de> References: <20240324234542.2038726-1-hch@lst.de> <20240324234542.2038726-2-hch@lst.de> <7d151430-c296-44de-8998-a20a0b526aab@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7d151430-c296-44de-8998-a20a0b526aab@redhat.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-Rspamd-Queue-Id: 56EB440009 X-Rspam-User: X-Rspamd-Server: rspam02 X-Stat-Signature: 4icwmwueywfnpdz3t8kt6q66mpkr84xx X-HE-Tag: 1711433093-553834 X-HE-Meta: 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 vxJL0fF5 1iC2Wa82Juu2eJSsdc88WUOeudzdOgjERHe3CHS99DfXyN0HFZYRRo0pK+VCAo8GOzhqHDYRs71uJpNQaKX8/09rVeyXiK4w6nS86D5EUo9rsqQk= 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: List-Subscribe: List-Unsubscribe: On Mon, Mar 25, 2024 at 11:33:31AM +0100, David Hildenbrand wrote: > ... I have similar patches lying around here (see bwlow). I added some > actual access permission checks. > > (I also realized, that if we get an anon folio in a COW mapping via follow_pte() > here, I suspect one might be able to do some nasty things. Just imagine if we > munmap(), free the anon folio, and then it gets used in other context ... At > least KVM/vfio handle that using references+MMU notifiers.) How about you just send out your series that seems to go further and I retract mine?