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 2C2C6EE49A5 for ; Thu, 24 Aug 2023 14:58:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237382AbjHXO5v (ORCPT ); Thu, 24 Aug 2023 10:57:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45484 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241960AbjHXO5g (ORCPT ); Thu, 24 Aug 2023 10:57:36 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C3FBF10D7 for ; Thu, 24 Aug 2023 07:57:34 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 622CF6701C for ; Thu, 24 Aug 2023 14:57:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 76DBBC433C9; Thu, 24 Aug 2023 14:57:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1692889053; bh=I9F1+4aPrNCfVDeUTuyJ+5OdRTlw1yyRI4FOml5T7rY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iiZq920TT1yUsbS4zLTP71dagMfj3/JvoprgJIBWbLDbGsMg16AapHC9YHjLL+j0w NGfPK5Z5SQqo/YQwwFdE4CDlHp4c+3d6CCWxseJmRNFJL61ICMZUQm7cV/rgHFVvsB TGKOYa9pGNYitAaM/ewD8EG/+4UVVu334C/e/9bw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Borislav Petkov (AMD)" Subject: [PATCH 5.15 136/139] x86/srso: Disable the mitigation on unaffected configurations Date: Thu, 24 Aug 2023 16:50:59 +0200 Message-ID: <20230824145029.328447509@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230824145023.559380953@linuxfoundation.org> References: <20230824145023.559380953@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: Borislav Petkov (AMD) commit e9fbc47b818b964ddff5df5b2d5c0f5f32f4a147 upstream. Skip the srso cmd line parsing which is not needed on Zen1/2 with SMT disabled and with the proper microcode applied (latter should be the case anyway) as those are not affected. Fixes: 5a15d8348881 ("x86/srso: Tie SBPB bit setting to microcode patch detection") Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20230813104517.3346-1-bp@alien8.de Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/bugs.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -2399,8 +2399,10 @@ static void __init srso_select_mitigatio * IBPB microcode has been applied. */ if ((boot_cpu_data.x86 < 0x19) && - (!cpu_smt_possible() || (cpu_smt_control == CPU_SMT_DISABLED))) + (!cpu_smt_possible() || (cpu_smt_control == CPU_SMT_DISABLED))) { setup_force_cpu_cap(X86_FEATURE_SRSO_NO); + return; + } } if (retbleed_mitigation == RETBLEED_MITIGATION_IBPB) { @@ -2686,6 +2688,9 @@ static ssize_t gds_show_state(char *buf) static ssize_t srso_show_state(char *buf) { + if (boot_cpu_has(X86_FEATURE_SRSO_NO)) + return sysfs_emit(buf, "Not affected\n"); + return sysfs_emit(buf, "%s%s\n", srso_strings[srso_mitigation], (cpu_has_ibpb_brtype_microcode() ? "" : ", no microcode"));