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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F3A4EC38142 for ; Tue, 31 Jan 2023 15:50:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=dfYpBn20oInZuvz8g1y5kcjfuxkmw4kJ61TIzVDGuBs=; b=nXDe52wc+atqVZ Iu4Ei4ApUQLFV45lN+jcNle3vbMSc/FF3Xb3yVfbzV2EAKygHss/GjsTIYxd554d3P5+ywCanvunh MyTBeqLtnpge6+BwprNN/ODoYwqQUYSRJHyN3vSvIHQ+Oo552hSYgbwdtJr6lP8rC4nBWmwCIUlGb wzo7DkFkaTBA6xR+3lTI67nIm+xpzV03VlNT1qtht6vFjCpV82TcpHYNJmWwk5AzvVKB0QLxZEazJ 895PcMPGbG0qLsVf1EsIf+TKT1oMYXCHix4baPuby7eaiOU9uQn3jHZ33GVdJCcuPF0j0GNfneida iG0hpiX42/mkSCDKIYFQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pMstU-008ZsT-QP; Tue, 31 Jan 2023 15:50:00 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pMstR-008Zro-Ke for linux-arm-kernel@lists.infradead.org; Tue, 31 Jan 2023 15:49:58 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2BB4F614B3; Tue, 31 Jan 2023 15:49:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6EEF1C433EF; Tue, 31 Jan 2023 15:49:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1675180197; bh=iJeEzqU61ETudd/26H20CF7VwrLvGyVEhOVWjRGFTFQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tRObx3cYosVBArRUGx3H86cpVC8vSJ88AKJf7qpGsFar4QPYj2zEWiL59YiLVtPeh QBrSv+6qrVJuOahGGjW0G5uhavZBkFxdpDoaUxjaRKM6dcsH8BkESPTSw82cSy9UjF tdSU1APONzmHeJkYlW5tvlxXrczJkwhMEzwj+0XrMddx11nqAjmt+tOZ4EORcYyAh0 uPW6NoxZEpF/YB9nOHJXgFLEnY2ZQCt+g+P3Q8/rzDrNsyg0SZj+DYmuD+PQ6Tmail al4COReC6Ky16Q76+nd/1rRflOKYGCdxX1oGzhttt8OEiwy6/OnW2KADOdhulo6ZFK 9GZ6ZVy6WwvaQ== Date: Tue, 31 Jan 2023 15:49:51 +0000 From: Will Deacon To: Robin Murphy Cc: Anshuman Khandual , linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, Mark Rutland , Andrew Morton , linux-kernel@vger.kernel.org, Mark Brown Subject: Re: [PATCH V2] arm64/mm: Intercept pfn changes in set_pte_at() Message-ID: <20230131154950.GB2646@willie-the-truck> References: <20230109052816.405335-1-anshuman.khandual@arm.com> <20230126133321.GB29148@willie-the-truck> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230131_074957_738071_4DAEBF91 X-CRM114-Status: GOOD ( 22.16 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Jan 27, 2023 at 12:43:17PM +0000, Robin Murphy wrote: > On 2023-01-26 13:33, Will Deacon wrote: > > On Tue, Jan 24, 2023 at 11:11:49AM +0530, Anshuman Khandual wrote: > > > On 1/9/23 10:58, Anshuman Khandual wrote: > > > > Changing pfn on a user page table mapped entry, without first going through > > > > break-before-make (BBM) procedure is unsafe. This just updates set_pte_at() > > > > to intercept such changes, via an updated pgattr_change_is_safe(). This new > > > > check happens via __check_racy_pte_update(), which has now been renamed as > > > > __check_safe_pte_update(). > > > > > > > > Cc: Catalin Marinas > > > > Cc: Will Deacon > > > > Cc: Mark Rutland > > > > Cc: Andrew Morton > > > > Cc: linux-arm-kernel@lists.infradead.org > > > > Cc: linux-kernel@vger.kernel.org > > > > Signed-off-by: Anshuman Khandual > > > > --- > > > > This applies on v6.2-rc3. This patch had some test time on an internal CI > > > > system without any issues being reported. > > > > > > Gentle ping, any updates on this patch ? Still any concerns ? > > > > I don't think we really got to the bottom of Mark's concerns with > > unreachable ptes on the stack, did we? I also have vague recollections > > of somebody (Robin?) running into issues with the vmap code not honouring > > BBM. > > Doesn't ring a bell, so either it wasn't me, or it was many years ago and > about 5 levels deep into trying to fix something else :/ Bah, sorry! Catalin reckons it may have been him talking about the vmemmap. Catalin -- any clues? Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel