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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 695D2C25B07 for ; Tue, 9 Aug 2022 14:01:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244709AbiHIOBU (ORCPT ); Tue, 9 Aug 2022 10:01:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230380AbiHIOBT (ORCPT ); Tue, 9 Aug 2022 10:01:19 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4838F271A; Tue, 9 Aug 2022 07:01:15 -0700 (PDT) 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 ams.source.kernel.org (Postfix) with ESMTPS id 9602DB8111F; Tue, 9 Aug 2022 14:01:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0D94DC433C1; Tue, 9 Aug 2022 14:01:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660053672; bh=u+a4xxI8QuroONub9HjlQCWDta7sG4zKmZv7pm4e4YQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=BqCEXUMORsYoPmP0TX81BzFZY+JxVRuIDNIJDwJyMmP1ljzVK0zj3ajutrpW6JxP3 v9AcpNw3Jd+XSv3AcYY5JxJ3WjdLf8tylmnTHCMzBAJmuoWWNQ1wSz4uh8G+BcR7H7 qzp31MJLYX9n2DH5YKN3sMJDHK9WTvgZSceadpRZwuCsxLYct7IQX4R9GIMTt4h0iz 2Cmm0vkMz+q23/7NHrWRw9dtTkAY+pHpPQr/5h78SGZFNOdRetRdf5bA8m0gL5czd6 layPBfn/2nP/+JtU/3GNMs7icW9SY8QkXZO3IbCrXv5UdOOGZF0uXBSw38UVPIjojv Kzn2k3i4UllqA== Date: Tue, 9 Aug 2022 10:01:10 -0400 From: Sasha Levin To: Ard Biesheuvel Cc: Greg Kroah-Hartman , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Anshuman Khandual , Will Deacon , catalin.marinas@arm.com, bp@suse.de, Jason@zx2c4.com, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH AUTOSEL 5.19 05/58] arm64: kernel: drop unnecessary PoC cache clean+invalidate Message-ID: References: <20220808013118.313965-1-sashal@kernel.org> <20220808013118.313965-5-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 08, 2022 at 11:05:29AM +0200, Ard Biesheuvel wrote: >On Mon, 8 Aug 2022 at 03:31, Sasha Levin wrote: >> >> From: Ard Biesheuvel >> >> [ Upstream commit 2e945851e26836c0f2d34be3763ddf55870e49fe ] >> >> Some early boot code runs before the virtual placement of the kernel is >> finalized, and we used to go back to the very start and recreate the ID >> map along with the page tables describing the virtual kernel mapping, >> and this involved setting some global variables with the caches off. >> >> In order to ensure that global state created by the KASLR code is not >> corrupted by the cache invalidation that occurs in that case, we needed >> to clean those global variables to the PoC explicitly. >> >> This is no longer needed now that the ID map is created only once (and >> the associated global variable updates are no longer repeated). So drop >> the cache maintenance that is no longer necessary. >> >> Signed-off-by: Ard Biesheuvel >> Reviewed-by: Anshuman Khandual >> Link: https://lore.kernel.org/r/20220624150651.1358849-9-ardb@kernel.org >> Signed-off-by: Will Deacon >> Signed-off-by: Sasha Levin > >NAK > >This patch *must* *not* be backported. It will break the boot. Appologies for this one, this was a technical issue on my end and I owe a beer for yourself and few other folks that should have been filtered out. I'll drop all your patches from the AUTOSEL queue. -- Thanks, Sasha