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 X-Spam-Level: X-Spam-Status: No, score=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6B33AC43465 for ; Fri, 18 Sep 2020 16:52:07 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0639220872 for ; Fri, 18 Sep 2020 16:52:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="a/yUjVGZ"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="BLyPSPrX" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0639220872 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=a2WDZBiwClFUpHYohe4hxclFBO72aKjSRHJ0TwAp6fQ=; b=a/yUjVGZy6cT5qQfb5TpDoR5N D3qZNdTEu/L67XLhXraKT2lEvgU5hcllSafoRT1OT70II8hivtTeexlnhiy6dAwCAuFTUjjkv2OS5 DcvSwT+lPfxhGsb7SvVhLckXDlSr9RarIdOjpC2PTwGD5TOP4XFiNnw3NuYUpC5p8B+Lu0Ov6B3LK 9hp9DpbS6yAZePCNHjoubhVo3k+nOKklBWGOQJWx311Zq8gOYIufzn7f4N5bsOO3bZWMH+pllnjQA HA99aCULnunze/LdSm5aDN+p1uBj7io3jH8ILegAXOtPQ9222smML/Z3jhYRpHZEciixj1zMvNX0B 0Apm14L/Q==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kJJaR-0007y0-1C; Fri, 18 Sep 2020 16:50:15 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kJJYF-00073B-KD for linux-arm-kernel@lists.infradead.org; Fri, 18 Sep 2020 16:48:03 +0000 Received: from localhost.localdomain (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CF1FE21534; Fri, 18 Sep 2020 16:47:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600447678; bh=oQoTdUlIkQK8isT9ZDSbmIEMNAHGS+lzfkEwRm49apM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BLyPSPrXoW/RZr8glzASUlY9Sf7OnxZa0vJfysw5HJAwWEUUdKuOLlcSnIK4d5LEO Ba6XPjISinT3Xx7oeWZq5htsRaj6CGGoS5XZEBGDhM9JWuaXV6Q9Vjha97k1Fn8tqC n9kEUxFrgZwTonKTY3OEi8Bd0gWMtkFmOApDsE1o= From: Will Deacon To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 12/19] arm64: Treat SSBS as a non-strict system feature Date: Fri, 18 Sep 2020 17:47:22 +0100 Message-Id: <20200918164729.31994-13-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200918164729.31994-1-will@kernel.org> References: <20200918164729.31994-1-will@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200918_124800_029217_CF155A5D X-CRM114-Status: GOOD ( 14.05 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Catalin Marinas , David Brazdil , Will Deacon , Suzuki K Poulose Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org If all CPUs discovered during boot have SSBS, then spectre-v4 will be considered to be "mitigated". However, we still allow late CPUs without SSBS to be onlined, albeit with a "SANITY CHECK" warning. This is problematic for userspace because it means that the system can quietly transition to "Vulnerable" at runtime. Avoid this by treating SSBS as a non-strict system feature: if all of the CPUs discovered during boot have SSBS, then late arriving secondaries better have it as well. Signed-off-by: Will Deacon --- arch/arm64/kernel/cpufeature.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 4bb45b1d4ae4..033e6c952705 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -227,7 +227,7 @@ static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = { static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = { ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_MPAMFRAC_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_RASFRAC_SHIFT, 4, 0), - ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_SSBS_SHIFT, 4, ID_AA64PFR1_SSBS_PSTATE_NI), + ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR1_SSBS_SHIFT, 4, ID_AA64PFR1_SSBS_PSTATE_NI), ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_BTI), FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_BT_SHIFT, 4, 0), ARM64_FTR_END, @@ -487,7 +487,7 @@ static const struct arm64_ftr_bits ftr_id_pfr1[] = { }; static const struct arm64_ftr_bits ftr_id_pfr2[] = { - ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR2_SSBS_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_SSBS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_CSV3_SHIFT, 4, 0), ARM64_FTR_END, }; @@ -1977,7 +1977,7 @@ static const struct arm64_cpu_capabilities arm64_features[] = { { .desc = "Speculative Store Bypassing Safe (SSBS)", .capability = ARM64_SSBS, - .type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, .matches = has_cpuid_feature, .sys_reg = SYS_ID_AA64PFR1_EL1, .field_pos = ID_AA64PFR1_SSBS_SHIFT, -- 2.28.0.681.g6f77f65b4e-goog _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel