From patchwork Wed Nov 4 05:27:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: patricia.domingues@canonical.com X-Patchwork-Id: 1393665 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=canonical.com Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4CQwCv1c4zz9sVK; Wed, 4 Nov 2020 16:28:09 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1kaBL0-0005Qp-EF; Wed, 04 Nov 2020 05:28:02 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1kaBKy-0005QL-Fw for kernel-team@lists.ubuntu.com; Wed, 04 Nov 2020 05:28:00 +0000 Received: from 1.general.patriciasd.us.vpn ([10.172.64.192] helo=localhost.localdomain) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1kaBKx-0004Rv-Qu for kernel-team@lists.ubuntu.com; Wed, 04 Nov 2020 05:28:00 +0000 From: patricia.domingues@canonical.com To: kernel-team@lists.ubuntu.com Subject: [SRU][F][G][H] [PATCH 0/2] Fix misalignment buffer on Power9 DD2.1 (LP: 1902694) Date: Wed, 4 Nov 2020 02:27:49 -0300 Message-Id: <20201104052751.4253-1-patricia.domingues@canonical.com> X-Mailer: git-send-email 2.17.1 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" BugLink: https://bugs.launchpad.net/bugs/1902694 SRU Justification: [Impact] * A data integrity issue was observed on POWER 9 (DD2.1) systems. * It affects Ubuntu 20.04 with kernel 5.4.0-52 and Ubuntu 20.10 with kernel 5.8.0-26 kernel. * The root cause is found in the compiling of p9_hmi_special_emu(). * When doing a VMX store (in __get_user_atomic_128_aligned()) to a buffer (vbuf), the buffer is not 128 bit aligned. [Fix] * 1da4a0272c54 "powerpc: Fix undetected data corruption with P9N DD2.1 VSX CI load emulation" * d1781f237047 "selftests/powerpc: Make alignment handler test P9N DD2.1 vector CI load workaround" [Test Case] * A POWER 9 (DD2.1) bare metal system is needed that has either Ubuntu 20.04, 20.10 or 21.04 installed. * It's best to test this based on a sample application and test case "selftests/powerpc: Make alignment handler test P9N DD2.1 vector CI load workaround" [Regression Potential] * The regression risk is relatively moderate, because: * it only happens with special VSX (vector) instructions in use, e.g. in p9_hmi_special_emu * it happens on bare metal only and only on POWER 9 (DD2.1) * and the changes are very overseeable (in total one effective code line per patch/commit) * Since only p9_hmi_special_emu is touched, this will break in case of any regressions, but this is already broken based on this bug. [Other] * According to the reporter this affects Ubuntu 20.04 / 5.4.0-52 and 20.10 / 5.8.0-26. * Since the development of Hirsute is already open the SRU is requested for Hirsute, too. * Patches got upstream accepted in v5.10-rc1 and v5.10-rc2. Michael Neuling (2): powerpc: Fix undetected data corruption with P9N DD2.1 VSX CI load emulation selftests/powerpc: Make alignment handler test P9N DD2.1 vector CI load workaround arch/powerpc/kernel/traps.c | 2 +- .../selftests/powerpc/alignment/alignment_handler.c | 8 ++++++-- 2 files changed, 7 insertions(+), 3 deletions(-) Acked-by: Kleber Sacilotto de Souza Acked-by: Stefan Bader