From nobody Sun Feb 8 12:31:16 2026 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1B2362EF293; Fri, 11 Jul 2025 16:09:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752250176; cv=none; b=KfpJB80coBbaoYsK+b8/1OPjG2nm9tyNRVcoxmK/nLYpySNiQFKF8JlW3MOAUXHL+Eo7S+ZBvbZqsVYXcpdvIp3a5xOWy3I+BMYqjGRsJeI6/BW08mQtx1ZZnkQ+JFH77B8zcvC/Zx3GWYaA7zJNybgTW0/l45Y+COA5TsQ6zPw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752250176; c=relaxed/simple; bh=X86Ze2Zydlnob7CJkpjWbCWIBR91vYZQp5uIwQyNg3I=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=V4zCbkzOfOdbQH3zGM2noDGuleIvaiDTyGI8AvgVPSVCU/dtR0TzDLyHkva03fRQ4qxHPbVAcv4KN4shjzoWwlOZQqU3K/bl6rjbfe/JZKbMwei7JaW0hHnn5aWzyoDHnjXCiX/W7tiCxS+V/7mtVYZxDOOp2Bc+J9cXQIIWwQQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=NM1UReH2; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=7FtQw7TH; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="NM1UReH2"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="7FtQw7TH" Date: Fri, 11 Jul 2025 16:09:32 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1752250173; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZBuqCveR3kvP1lxHGPDQnykARz39toEo9xz8YvhW1c4=; b=NM1UReH2W5JGfulWg6r7WCKRBpVwUi/gxFmSIBkG7e35hX7Z3GWKRgkEtlXzaFKuHD+WT7 LGHf8EvMwpIm8hdRZu62DuNBq74gnFfgfrWYURvCD0NLXsZ048QHRZJj2venFnqSopV971 teUGLge5eXzfSVV/JOkxVEnvSGC8qNKiqZL+6GjrqhMIjndLJvNJzl42ccAmfgXUW4UQCP IsueRIaQhGNWH1zQdnl2p4QHHwqGO6adxxJTwUc4ppsbwveigGeI0vVy6WrByGcXOrkyiu zDTeUtnx7P/PXclSqrRcL7BeSNuyv/6RBPLlb/xTY4CQ3jxZnEspLfCswu9GPQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1752250173; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZBuqCveR3kvP1lxHGPDQnykARz39toEo9xz8YvhW1c4=; b=7FtQw7THct8CFOllb8pT5uF/yMaOPrxDMCBL+fjnXlITNwORK9FcZIZ1DsXG28euyK+Zr5 0+VIbjO+o2yXyaAg== From: "tip-bot2 for David Kaplan" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/bugs] x86/bugs: Add attack vector controls for SRSO Cc: David Kaplan , "Borislav Petkov (AMD)" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20250707183316.1349127-18-david.kaplan@amd.com> References: <20250707183316.1349127-18-david.kaplan@amd.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <175225017205.406.15490827974113086965.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the x86/bugs branch of tip: Commit-ID: eda718fde6159b2e64978637ebb3f1ae98180555 Gitweb: https://git.kernel.org/tip/eda718fde6159b2e64978637ebb3f1ae9= 8180555 Author: David Kaplan AuthorDate: Mon, 07 Jul 2025 13:33:12 -05:00 Committer: Borislav Petkov (AMD) CommitterDate: Fri, 11 Jul 2025 17:56:41 +02:00 x86/bugs: Add attack vector controls for SRSO Use attack vector controls to determine if SRSO mitigation is required. Signed-off-by: David Kaplan Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/20250707183316.1349127-18-david.kaplan@amd.com --- arch/x86/kernel/cpu/bugs.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 2128623..eef6ccd 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -3123,14 +3123,19 @@ early_param("spec_rstack_overflow", srso_parse_cmdl= ine); =20 static void __init srso_select_mitigation(void) { - if (!boot_cpu_has_bug(X86_BUG_SRSO) || cpu_mitigations_off()) + if (!boot_cpu_has_bug(X86_BUG_SRSO)) { srso_mitigation =3D SRSO_MITIGATION_NONE; - - if (srso_mitigation =3D=3D SRSO_MITIGATION_NONE) return; + } =20 - if (srso_mitigation =3D=3D SRSO_MITIGATION_AUTO) - srso_mitigation =3D SRSO_MITIGATION_SAFE_RET; + if (srso_mitigation =3D=3D SRSO_MITIGATION_AUTO) { + if (should_mitigate_vuln(X86_BUG_SRSO)) { + srso_mitigation =3D SRSO_MITIGATION_SAFE_RET; + } else { + srso_mitigation =3D SRSO_MITIGATION_NONE; + return; + } + } =20 /* Zen1/2 with SMT off aren't vulnerable to SRSO. */ if (boot_cpu_data.x86 < 0x19 && !cpu_smt_possible()) {