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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 64525C3A5A1 for ; Wed, 28 Aug 2019 16:08:15 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 37FB120828 for ; Wed, 28 Aug 2019 16:08:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="BWcysVYV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 37FB120828 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject: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=7EV58+xTijv3Ofo2W3RDA45Bng8+Uk5FHrlUaThGpoA=; b=BWcysVYVnM0UOT PjPjBgu5di9wylnpmuqlP3aZmjuSM+9Vb3jpSQ48ntAOCRwpxNsp/0sIP09L+alSlYhzg0JSy5dPW cn46esjzvyhfCEExE+O/cVb2vRdY7nwdm7mddSxr3frDMBjwC+MaiMH4RQbMYkQOcm1tpWsHUXoSu ewJTSLNvl4WVGNqUsvE8LMS5HnQRSPPPQ0qgeOLyXiutJp+xyzQ8bFyf6Upb4Vdm5aidpCbi3TN6q 17s6gmX+m9y7C+yM3PZLc8oZ3JJRR3CTmggyFSkHk3356B4gmESHvVMNP860TkfYWG3jdwO4JiTHY u7ji3VSNdtcadkii1Dxw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i30UY-0001yo-OK; Wed, 28 Aug 2019 16:08:14 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i30UU-0001yP-UU for linux-arm-kernel@lists.infradead.org; Wed, 28 Aug 2019 16:08:12 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9F9CD28; Wed, 28 Aug 2019 09:08:08 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 496C53F59C; Wed, 28 Aug 2019 09:08:07 -0700 (PDT) Date: Wed, 28 Aug 2019 17:08:05 +0100 From: Mark Rutland To: Viresh Kumar Subject: Re: [PATCH v4.4 V2 24/43] arm64: Add skeleton to harden the branch predictor against aliasing attacks Message-ID: <20190828160804.GB42408@lakrids.cambridge.arm.com> References: <4349161f0ed572bbc6bff64bad94aa96d07b27ff.1562908075.git.viresh.kumar@linaro.org> <20190731164556.GI39768@lakrids.cambridge.arm.com> <20190801052011.2hrei36v4zntyfn5@vireshk-i7> <20190806121816.GD475@lakrids.cambridge.arm.com> <20190808120600.qhbhopvp4e5w33at@vireshk-i7> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190808120600.qhbhopvp4e5w33at@vireshk-i7> User-Agent: Mutt/1.11.1+11 (2f07cb52) (2018-12-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190828_090811_032069_DBF552CD X-CRM114-Status: GOOD ( 14.66 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Julien Thierry , Marc Zyngier , Catalin Marinas , Will Deacon , stable@vger.kernel.org, mark.brown@arm.com, Russell King , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Aug 08, 2019 at 05:36:00PM +0530, Viresh Kumar wrote: > On 06-08-19, 13:18, Mark Rutland wrote: > > Upstream and in v4.9, the meltdown patches came before the spectre > > patches, and doing this in the opposite order causes context problems > > like the above. > > > > Given that, I think it would be less surprising to do the meltdown > > backport first, though I apprecaite that's more work to get these > > patches in. :/ > > I attempted meltdown backport in the last two days and the amount of > extra patches to be backported is enormous. And I am not sure if > everything is alright as well now, and things will greatly rely on > reviews from you for it. > > For this series, what about just backporting for now to account for > CSV3 ? And attempting meltdown backport separately later ? > > 179a56f6f9fb arm64: Take into account ID_AA64PFR0_EL1.CSV3 I don't think that buys us anything; that's still going to cause some context problems (e.g. for commit 179a56f6f9fb itself), and still means that the v4.4 backport differs from all the others. If it's really not feasible to do the meltdown patches first, then I reluctantly agree that we should just do the spectre bits alone if there aren't major changes that have to be made to entry.S and friends as a result. Could you send a v3 (of just the spectre bits) with the changes requested so far? Thanks, Mark. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel