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 5DD2BC636CD for ; Mon, 30 Jan 2023 21:40:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230514AbjA3VkQ (ORCPT ); Mon, 30 Jan 2023 16:40:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57028 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229963AbjA3VkO (ORCPT ); Mon, 30 Jan 2023 16:40:14 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B81B01BDD for ; Mon, 30 Jan 2023 13:40:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1675114813; x=1706650813; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=TFZOhQupMCyhWl530Dlvg8nqRMsH2GVlEz63WCWbwRI=; b=SX+jIj1QJrEkquhHr4DStUzH1VPzQ8DjADtvPk64+b3tKGBstOKXr5TI ScoLb3mqoJNHYkVB/JCl493x3GY9JjK2MmO54cXe4RvY2w24c3z8jC7JF INS1yO1GjmmctFQntOJdkfKAGmUhQOlXQ1vrlZgEOoNx2LsS+4SMdV+3n Z/+k3DWuheSfQj/c/eW7IyFvsZHNexxEuf/+2jzvMgwGHQvQVWtKc2a6z a3E8XDRKWvAN5+VCy9NKIl9QMS2R8VRn/u6I+HVWxDjQNOKvzXfmcHxkE JawMsHOU5RjS14qJZ6cLCxARzDwhFQsL7Y3ApIHgNtLY7RgwXmOEXVzvY A==; X-IronPort-AV: E=McAfee;i="6500,9779,10606"; a="328955479" X-IronPort-AV: E=Sophos;i="5.97,259,1669104000"; d="scan'208";a="328955479" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Jan 2023 13:40:12 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10606"; a="696571856" X-IronPort-AV: E=Sophos;i="5.97,259,1669104000"; d="scan'208";a="696571856" Received: from araj-ucode.jf.intel.com ([10.23.0.19]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Jan 2023 13:40:12 -0800 From: Ashok Raj To: Borislav Petkov , Thomas Gleixner Cc: Ashok Raj , LKML , x86 , Ingo Molnar , Tony Luck , Dave Hansen , Alison Schofield , Reinette Chatre , Tom Lendacky , Stefan Talpalaru , David Woodhouse , Benjamin Herrenschmidt , Jonathan Corbet , "Rafael J . Wysocki" , Peter Zilstra , Andy Lutomirski , Andrew Cooper , Boris Ostrovsky , Martin Pohlack Subject: [Patch v3 Part2 1/9] x86/microcode: Taint kernel only if microcode loading was successful Date: Mon, 30 Jan 2023 13:39:47 -0800 Message-Id: <20230130213955.6046-2-ashok.raj@intel.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20230130213955.6046-1-ashok.raj@intel.com> References: <20230130213955.6046-1-ashok.raj@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently when late loading is aborted due to check_online_cpu(), kernel still ends up tainting the kernel. Taint only when microcode loading was successful. Suggested-by: Thomas Gleixner Signed-off-by: Ashok Raj Cc: LKML Cc: x86 Cc: Ingo Molnar Cc: Tony Luck Cc: Dave Hansen Cc: Alison Schofield Cc: Reinette Chatre Cc: Thomas Gleixner (Intel) Cc: Tom Lendacky Cc: Stefan Talpalaru Cc: David Woodhouse Cc: Benjamin Herrenschmidt Cc: Jonathan Corbet Cc: Rafael J. Wysocki Cc: Peter Zilstra (Intel) Cc: Andy Lutomirski Cc: Andrew Cooper Cc: Boris Ostrovsky Cc: Martin Pohlack --- v1->v2: (Thomas) - Remove unnecessary assignment of ret that's being overwritten. - Taint kernel only of loading was successful --- arch/x86/kernel/cpu/microcode/core.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c index 61d57d9b93ee..1c6831b8b244 100644 --- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -472,7 +472,8 @@ static ssize_t reload_store(struct device *dev, enum ucode_state tmp_ret = UCODE_OK; int bsp = boot_cpu_data.cpu_index; unsigned long val; - ssize_t ret = 0; + int load_ret = -1; + ssize_t ret; ret = kstrtoul(buf, 0, &val); if (ret) @@ -488,20 +489,26 @@ static ssize_t reload_store(struct device *dev, goto put; tmp_ret = microcode_ops->request_microcode_fw(bsp, µcode_pdev->dev); - if (tmp_ret != UCODE_NEW) + if (tmp_ret != UCODE_NEW) { + ret = size; goto put; + } mutex_lock(µcode_mutex); - ret = microcode_reload_late(); + load_ret = microcode_reload_late(); mutex_unlock(µcode_mutex); put: cpus_read_unlock(); - if (ret == 0) + /* + * Taint only when loading was successful + */ + if (load_ret == 0) { ret = size; - - add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK); + add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK); + pr_warn("Microcode late loading tainted the kernel\n"); + } return ret; } -- 2.37.2