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=-2.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 5EF85C43387 for ; Wed, 16 Jan 2019 10:33:15 +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 2A9C8206C2 for ; Wed, 16 Jan 2019 10:33:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="rTAW886W" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2A9C8206C2 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:Date: Message-ID:From:References:To:Subject:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=IcYyR1IdHNND4BnZQWHNSS5m0kpNnEMp5Kq5c8zngY8=; b=rTAW886WK4io+D On1m23l9whPpbAj3qWi9jiAcgS6mD8jZqjm0BUmm2HdQb0x65YvA2f8cnEJDJBswh8LQpcZMFew9j NWANMZoDdmeEUyQ9/9h5lrWQOjnNCFItUxCiXsqLgOvbGa8OVDfExFLZqOB7mSed3vLr341MJZDbm dWjrPmp03TdNdrE4WvUaMcuv2+MPfOrSwhjtJbTMqNhvHKzt4f7MtACv0ived59rFuYfWduDCbtZn vtR8mUKKrq2LjIH9QNU6nOvNUDfgF4dWLYU0TpxCYMWAFHNYm5mJMkbG952PgdO21b1KoGb06lcQb HECuVOTRIZ1+vFUAltbw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gjiVS-0006yZ-1q; Wed, 16 Jan 2019 10:33:10 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gjiVN-0006xp-08 for linux-arm-kernel@lists.infradead.org; Wed, 16 Jan 2019 10:33:07 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 931B8A78; Wed, 16 Jan 2019 02:33:04 -0800 (PST) Received: from [10.1.196.105] (eglon.cambridge.arm.com [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6081B3F5AF; Wed, 16 Jan 2019 02:33:02 -0800 (PST) Subject: Re: [PATCH] arm64: kpti: Update arm64_kernel_use_ng_mappings() when forced on To: John Garry References: <20190115184917.248995-1-james.morse@arm.com> <21310b0b-8a75-1adf-a844-b2f3f520fa2d@huawei.com> From: James Morse Message-ID: <5218967d-e12b-7eff-6d93-7feda563267a@arm.com> Date: Wed, 16 Jan 2019 10:33:00 +0000 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:60.0) Gecko/20100101 Thunderbird/60.3.1 MIME-Version: 1.0 In-Reply-To: <21310b0b-8a75-1adf-a844-b2f3f520fa2d@huawei.com> Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190116_023305_049777_E165C69D X-CRM114-Status: GOOD ( 12.21 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Ard Biesheuvel , Catalin Marinas , Will Deacon , Linuxarm , "Guohanjun \(Hanjun Guo\)" , 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 Hi John, On 16/01/2019 09:38, John Garry wrote: > On 15/01/2019 18:49, James Morse wrote: >> Since commit b89d82ef01b3 ("arm64: kpti: Avoid rewriting early page > > About b89d82ef01b3, I got an *unconfirmed* (emphasis on this, I don't want to > cry wolf) report yesterday that the symptom I saw (boot delay) has been seen on > 5.0-rc2 on our D06 board. I could not see it. You can still cause kpti_install_ng_mappings() to rewrite the page-tables if you don't have CONFIG_RANDOMIZE_BASE (or there is no seed), so its not enabled early, and unmap_kernel_at_el0() thinks the CPU is vulnerable, so enables it late. > Please note that this would be same board which we saw this on: > https://lkml.org/lkml/2018/6/20/589 > > I only witnessed the issue on the predecessor A72-based D05 board. 2a355ec25729 whitelisted the CPUs on this board. Unless you force kpti on, and disable KASLR you shouldn't see it. > The reporter is very busy, but we'll keep tabs on it. Thanks! James _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel