From patchwork Sun Oct 27 21:00:45 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 177844 Delivered-To: patch@linaro.org Received: by 2002:a92:409a:0:0:0:0:0 with SMTP id d26csp2532065ill; Sun, 27 Oct 2019 14:09:50 -0700 (PDT) X-Google-Smtp-Source: APXvYqzwX/vQzcUOyX0yTePug58iNP0vSbcuZCyijtKiSvJSHY/thQI8JFVA5GpRWosV0tFZuBY/ X-Received: by 2002:a17:906:5007:: with SMTP id s7mr13775439ejj.181.1572210590423; Sun, 27 Oct 2019 14:09:50 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1572210590; cv=none; d=google.com; s=arc-20160816; b=DXjVnTRSe+siv2q1yayAo+GXccBsEuLQ5U0z14aSF9uubCH4W79QHFijpr0KwTVMPx OmtQqJTTuYtt72OfTExkOqx2q60L1gVuhfay+PUHOFAowgY2yG9VwnKaE1F/EW7LGr7S vEE5bpS186ZsvPeGwg/IJ6JzPblBIEpkuDAhsr1F316Kj5yNpsa+UDNyQh6kCywVnAFl +UFr7hb9cZ87Ci/ylkmXWTsO90jOrmzJDdBt6pLyjwNkfHduwqz/R4SeThWol+W7SmtA rutsPJqOL4nNL6bwCqupva+OasMeSTfOINOcsJwrH4k80GhCnMESCAWxum2Y50MR0UtS 4tZw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=pkp1XO70GYIWUhgGNXkRoHuLz3Vx0dnFVA+6RCBTJZE=; b=u+64LfGTLcz3LGeBLYDpc8kx6CwEQq+TJAbjGGTASSSQKOsG1NqGtz+olw8IsT8mJF RPohpsmozf78R5CSckGDkSyN7PRpvhGSh1u3Is6M6UX9mHLpaZF5iphpNmuZbTIeC76z yd8FX5UXQR77g1+shHGWbtqTGDI23p4mFEfwyefGp5pwKTVf+PmVJBWDh6eGuupsjKr4 vV0zKIPZFTvcQXWi9up+OU1PEixzs1vPI9ru1CypQhwgq48uGVIFl+GVnXdShG3b8Km4 qhWFPN8HGV7DvDUdmd0yQ5JEjranOIdV4a+uIhXopmsbA6EZIjW5wCXj/mjCnx08lnrE zt1A== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b="owzv1C/p"; spf=pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id z7si6146903edi.318.2019.10.27.14.09.50; Sun, 27 Oct 2019 14:09:50 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b="owzv1C/p"; spf=pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729562AbfJ0VJs (ORCPT + 14 others); Sun, 27 Oct 2019 17:09:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:56200 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729553AbfJ0VJs (ORCPT ); Sun, 27 Oct 2019 17:09:48 -0400 Received: from localhost (100.50.158.77.rev.sfr.net [77.158.50.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 900782064A; Sun, 27 Oct 2019 21:09:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572210587; bh=5IYsMnwEVU7S0aJmWZ1jf2IkeC4mjTIg6SGyMtNRQpE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=owzv1C/pCyqHU6dhx76/IjY/vC8X8DFVlNyDmFbLsISexpM6ygILZ9PAbVYZPQjfZ 0GL5gMfbl2lHu1y0XqFCbFZt+/FFRcDvS9lpItlfXJ6d8zFv6RfhxScWMEbw0sssae Q6n7uFp5HiPR7s3cYuPh7rz1yJfchBDcYX2ButWE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Suzuki K Poulose , Will Deacon , Catalin Marinas , Ard Biesheuvel Subject: [PATCH 4.14 068/119] arm64: cpufeature: Detect SSBS and advertise to userspace Date: Sun, 27 Oct 2019 22:00:45 +0100 Message-Id: <20191027203334.219935634@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191027203259.948006506@linuxfoundation.org> References: <20191027203259.948006506@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Will Deacon [ Upstream commit d71be2b6c0e19180b5f80a6d42039cc074a693a2 ] Armv8.5 introduces a new PSTATE bit known as Speculative Store Bypass Safe (SSBS) which can be used as a mitigation against Spectre variant 4. Additionally, a CPU may provide instructions to manipulate PSTATE.SSBS directly, so that userspace can toggle the SSBS control without trapping to the kernel. This patch probes for the existence of SSBS and advertise the new instructions to userspace if they exist. Reviewed-by: Suzuki K Poulose Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman --- arch/arm64/include/asm/cpucaps.h | 3 ++- arch/arm64/include/asm/sysreg.h | 16 ++++++++++++---- arch/arm64/include/uapi/asm/hwcap.h | 1 + arch/arm64/kernel/cpufeature.c | 19 +++++++++++++++++-- arch/arm64/kernel/cpuinfo.c | 1 + 5 files changed, 33 insertions(+), 7 deletions(-) --- a/arch/arm64/include/asm/cpucaps.h +++ b/arch/arm64/include/asm/cpucaps.h @@ -44,7 +44,8 @@ #define ARM64_HARDEN_BRANCH_PREDICTOR 24 #define ARM64_SSBD 25 #define ARM64_MISMATCHED_CACHE_TYPE 26 +#define ARM64_SSBS 27 -#define ARM64_NCAPS 27 +#define ARM64_NCAPS 28 #endif /* __ASM_CPUCAPS_H */ --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -297,6 +297,7 @@ #define SYS_ICH_LR15_EL2 __SYS__LR8_EL2(7) /* Common SCTLR_ELx flags. */ +#define SCTLR_ELx_DSSBS (1UL << 44) #define SCTLR_ELx_EE (1 << 25) #define SCTLR_ELx_WXN (1 << 19) #define SCTLR_ELx_I (1 << 12) @@ -316,7 +317,7 @@ (1 << 10) | (1 << 13) | (1 << 14) | (1 << 15) | \ (1 << 17) | (1 << 20) | (1 << 21) | (1 << 24) | \ (1 << 26) | (1 << 27) | (1 << 30) | (1 << 31) | \ - (0xffffffffUL << 32)) + (0xffffefffUL << 32)) #ifdef CONFIG_CPU_BIG_ENDIAN #define ENDIAN_SET_EL2 SCTLR_ELx_EE @@ -330,7 +331,7 @@ #define SCTLR_EL2_SET (ENDIAN_SET_EL2 | SCTLR_EL2_RES1) #define SCTLR_EL2_CLEAR (SCTLR_ELx_M | SCTLR_ELx_A | SCTLR_ELx_C | \ SCTLR_ELx_SA | SCTLR_ELx_I | SCTLR_ELx_WXN | \ - ENDIAN_CLEAR_EL2 | SCTLR_EL2_RES0) + SCTLR_ELx_DSSBS | ENDIAN_CLEAR_EL2 | SCTLR_EL2_RES0) #if (SCTLR_EL2_SET ^ SCTLR_EL2_CLEAR) != 0xffffffffffffffff #error "Inconsistent SCTLR_EL2 set/clear bits" @@ -354,7 +355,7 @@ (1 << 29)) #define SCTLR_EL1_RES0 ((1 << 6) | (1 << 10) | (1 << 13) | (1 << 17) | \ (1 << 21) | (1 << 27) | (1 << 30) | (1 << 31) | \ - (0xffffffffUL << 32)) + (0xffffefffUL << 32)) #ifdef CONFIG_CPU_BIG_ENDIAN #define ENDIAN_SET_EL1 (SCTLR_EL1_E0E | SCTLR_ELx_EE) @@ -371,7 +372,7 @@ SCTLR_EL1_UCI | SCTLR_EL1_RES1) #define SCTLR_EL1_CLEAR (SCTLR_ELx_A | SCTLR_EL1_CP15BEN | SCTLR_EL1_ITD |\ SCTLR_EL1_UMA | SCTLR_ELx_WXN | ENDIAN_CLEAR_EL1 |\ - SCTLR_EL1_RES0) + SCTLR_ELx_DSSBS | SCTLR_EL1_RES0) #if (SCTLR_EL1_SET ^ SCTLR_EL1_CLEAR) != 0xffffffffffffffff #error "Inconsistent SCTLR_EL1 set/clear bits" @@ -417,6 +418,13 @@ #define ID_AA64PFR0_EL0_64BIT_ONLY 0x1 #define ID_AA64PFR0_EL0_32BIT_64BIT 0x2 +/* id_aa64pfr1 */ +#define ID_AA64PFR1_SSBS_SHIFT 4 + +#define ID_AA64PFR1_SSBS_PSTATE_NI 0 +#define ID_AA64PFR1_SSBS_PSTATE_ONLY 1 +#define ID_AA64PFR1_SSBS_PSTATE_INSNS 2 + /* id_aa64mmfr0 */ #define ID_AA64MMFR0_TGRAN4_SHIFT 28 #define ID_AA64MMFR0_TGRAN64_SHIFT 24 --- a/arch/arm64/include/uapi/asm/hwcap.h +++ b/arch/arm64/include/uapi/asm/hwcap.h @@ -48,5 +48,6 @@ #define HWCAP_USCAT (1 << 25) #define HWCAP_ILRCPC (1 << 26) #define HWCAP_FLAGM (1 << 27) +#define HWCAP_SSBS (1 << 28) #endif /* _UAPI__ASM_HWCAP_H */ --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -145,6 +145,11 @@ static const struct arm64_ftr_bits ftr_i ARM64_FTR_END, }; +static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = { + ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_SSBS_SHIFT, 4, ID_AA64PFR1_SSBS_PSTATE_NI), + ARM64_FTR_END, +}; + static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = { S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN4_SHIFT, 4, ID_AA64MMFR0_TGRAN4_NI), S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN64_SHIFT, 4, ID_AA64MMFR0_TGRAN64_NI), @@ -345,7 +350,7 @@ static const struct __ftr_reg_entry { /* Op1 = 0, CRn = 0, CRm = 4 */ ARM64_FTR_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0), - ARM64_FTR_REG(SYS_ID_AA64PFR1_EL1, ftr_raz), + ARM64_FTR_REG(SYS_ID_AA64PFR1_EL1, ftr_id_aa64pfr1), /* Op1 = 0, CRn = 0, CRm = 5 */ ARM64_FTR_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0), @@ -625,7 +630,6 @@ void update_cpu_features(int cpu, /* * EL3 is not our concern. - * ID_AA64PFR1 is currently RES0. */ taint |= check_update_ftr_reg(SYS_ID_AA64PFR0_EL1, cpu, info->reg_id_aa64pfr0, boot->reg_id_aa64pfr0); @@ -1045,6 +1049,16 @@ static const struct arm64_cpu_capabiliti .min_field_value = 1, }, #endif + { + .desc = "Speculative Store Bypassing Safe (SSBS)", + .capability = ARM64_SSBS, + .type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE, + .matches = has_cpuid_feature, + .sys_reg = SYS_ID_AA64PFR1_EL1, + .field_pos = ID_AA64PFR1_SSBS_SHIFT, + .sign = FTR_UNSIGNED, + .min_field_value = ID_AA64PFR1_SSBS_PSTATE_ONLY, + }, {}, }; @@ -1087,6 +1101,7 @@ static const struct arm64_cpu_capabiliti HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_LRCPC), HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, HWCAP_ILRCPC), HWCAP_CAP(SYS_ID_AA64MMFR2_EL1, ID_AA64MMFR2_AT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, HWCAP_USCAT), + HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_SSBS_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_SSBS_PSTATE_INSNS, CAP_HWCAP, HWCAP_SSBS), {}, }; --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -80,6 +80,7 @@ static const char *const hwcap_str[] = { "uscat", "ilrcpc", "flagm", + "ssbs", NULL };