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 77751C61DA4 for ; Wed, 15 Mar 2023 12:17:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231676AbjCOMRd (ORCPT ); Wed, 15 Mar 2023 08:17:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41930 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231508AbjCOMRb (ORCPT ); Wed, 15 Mar 2023 08:17:31 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 271158B336 for ; Wed, 15 Mar 2023 05:17:09 -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 dfw.source.kernel.org (Postfix) with ESMTPS id A82266174E for ; Wed, 15 Mar 2023 12:17:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD9E8C433EF; Wed, 15 Mar 2023 12:17:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678882628; bh=buYeAIRY2wqFGhQxe98AfKK0TDFRnr1z58DCbchKvsY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AkILneenejgkUV3Q6bS70Pj9MrlCm88scXTTTsdza4dL1lG3icvdDWU0f7v7PuP3L 2IaToI3U1XRP32ZI3bcZvQLzj31lKnIVT4WjhTP7TGpmw7iu6yclFLKCZuqXFXbXWC 2mAjgJoFkoLrbTh7ki27Cwffc17P9N/D3Svi39kc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tavis Ormandy , Andrew Cooper , "Borislav Petkov (AMD)" , stable@kernel.org Subject: [PATCH 5.4 02/68] x86/CPU/AMD: Disable XSAVES on AMD family 0x17 Date: Wed, 15 Mar 2023 13:11:56 +0100 Message-Id: <20230315115726.197012029@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230315115726.103942885@linuxfoundation.org> References: <20230315115726.103942885@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Andrew Cooper commit b0563468eeac88ebc70559d52a0b66efc37e4e9d upstream. AMD Erratum 1386 is summarised as: XSAVES Instruction May Fail to Save XMM Registers to the Provided State Save Area This piece of accidental chronomancy causes the %xmm registers to occasionally reset back to an older value. Ignore the XSAVES feature on all AMD Zen1/2 hardware. The XSAVEC instruction (which works fine) is equivalent on affected parts. [ bp: Typos, move it into the F17h-specific function. ] Reported-by: Tavis Ormandy Signed-off-by: Andrew Cooper Signed-off-by: Borislav Petkov (AMD) Cc: Link: https://lore.kernel.org/r/20230307174643.1240184-1-andrew.cooper3@citrix.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/amd.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -205,6 +205,15 @@ static void init_amd_k6(struct cpuinfo_x return; } #endif + /* + * Work around Erratum 1386. The XSAVES instruction malfunctions in + * certain circumstances on Zen1/2 uarch, and not all parts have had + * updated microcode at the time of writing (March 2023). + * + * Affected parts all have no supervisor XSAVE states, meaning that + * the XSAVEC instruction (which works fine) is equivalent. + */ + clear_cpu_cap(c, X86_FEATURE_XSAVES); } static void init_amd_k7(struct cpuinfo_x86 *c)