From patchwork Tue Apr 21 21:52:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502349 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 30CEF1667 for ; Tue, 21 Apr 2020 21:54:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A3D12072D for ; Tue, 21 Apr 2020 21:54:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726392AbgDUVxc (ORCPT ); Tue, 21 Apr 2020 17:53:32 -0400 Received: from mga18.intel.com ([134.134.136.126]:11578 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726385AbgDUVx3 (ORCPT ); Tue, 21 Apr 2020 17:53:29 -0400 IronPort-SDR: CSAPzBBjbGzhUEayXUFfhj5pFTz3GZ86VXox9dKYgKn4CEI+HXMAE3IO9DKKxSF+pSu+dImo9J gCxUfPx7T3ow== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:53:27 -0700 IronPort-SDR: yT3yVqVzjq4wSaz67hv3IcItFEvOoC3Mw2uzXMBpTY6Dt5so8gW+WqJ6gzjA5dux9WR2UcENpE bTqzn4PaNlsA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260459" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:53:23 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Jarkko Sakkinen Subject: [PATCH v29 01/20] x86/sgx: Update MAINTAINERS Date: Wed, 22 Apr 2020 00:52:57 +0300 Message-Id: <20200421215316.56503-2-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org Add the maintainer information for the SGX subsystem. Signed-off-by: Jarkko Sakkinen --- MAINTAINERS | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index fcd79fc38928..6dca914d6926 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -8722,6 +8722,17 @@ F: Documentation/x86/intel_txt.rst F: include/linux/tboot.h F: arch/x86/kernel/tboot.c +INTEL SGX +M: Jarkko Sakkinen +M: Sean Christopherson +L: linux-sgx@vger.kernel.org +S: Maintained +Q: https://patchwork.kernel.org/project/intel-sgx/list/ +T: git https://github.com/jsakkine-intel/linux-sgx.git +F: arch/x86/include/uapi/asm/sgx.h +F: arch/x86/kernel/cpu/sgx/* +K: \bSGX_ + INTERCONNECT API M: Georgi Djakov L: linux-pm@vger.kernel.org From patchwork Tue Apr 21 21:52:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502341 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6321F17EA for ; Tue, 21 Apr 2020 21:54:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5129420736 for ; Tue, 21 Apr 2020 21:54:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726424AbgDUVxg (ORCPT ); Tue, 21 Apr 2020 17:53:36 -0400 Received: from mga17.intel.com ([192.55.52.151]:55732 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726385AbgDUVxe (ORCPT ); Tue, 21 Apr 2020 17:53:34 -0400 IronPort-SDR: z/eO0ikdCze8/BOMbl/Ys4J4yriPm5dLQwHWOz58jv+gFbMdpJwCXPYKK8lxcw1gxa0UEMfyYb SYOC+CVFRxjw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:53:33 -0700 IronPort-SDR: OrbSMqnQEW/yeOF8pmja0QKKZrCyRT5I94W1zGmZXX+pfH76+c6R6JZTJyzSR+5uPZ12L37M5H /GI/KJVVAySg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260503" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:53:28 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Jarkko Sakkinen Subject: [PATCH v29 02/20] x86/cpufeatures: x86/msr: Add Intel SGX hardware bits Date: Wed, 22 Apr 2020 00:52:58 +0300 Message-Id: <20200421215316.56503-3-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org From: Sean Christopherson Add X86_FEATURE_SGX from CPUID.(EAX=7, ECX=1), which informs whether the CPU has SGX. Add X86_FEATURE_SGX1 and X86_FEATURE_SGX2 from CPUID.(EAX=12H, ECX=0), which describe the level of SGX support available [1]. Remap CPUID.(EAX=12H, ECX=0) bits to the Linux fake CPUID 8 in order to conserve some space. Keep the bit positions intact because KVM requires this. Reserve bits 0-7 for SGX in order to maintain this invariant also when new SGX specific feature bits get added. Add IA32_FEATURE_CONTROL_SGX_ENABLE. BIOS can use this bit to opt-in SGX before locking the feature control MSR [2]. [1] Intel SDM: 36.7.2 Intel® SGX Resource Enumeration Leaves [2] Intel SDM: 36.7.1 Intel® SGX Opt-In Configuration Signed-off-by: Sean Christopherson Co-developed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- arch/x86/include/asm/cpufeature.h | 5 +++-- arch/x86/include/asm/cpufeatures.h | 7 ++++++- arch/x86/include/asm/disabled-features.h | 18 +++++++++++++++--- arch/x86/include/asm/msr-index.h | 1 + arch/x86/include/asm/required-features.h | 2 +- arch/x86/kernel/cpu/common.c | 4 ++++ tools/arch/x86/include/asm/cpufeatures.h | 7 ++++++- 7 files changed, 36 insertions(+), 8 deletions(-) diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 59bf91c57aa8..efbdba5170a3 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -30,6 +30,7 @@ enum cpuid_leafs CPUID_7_ECX, CPUID_8000_0007_EBX, CPUID_7_EDX, + CPUID_12_EAX, }; #ifdef CONFIG_X86_FEATURE_NAMES @@ -89,7 +90,7 @@ extern const char * const x86_bug_flags[NBUGINTS*32]; CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) || \ CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 18, feature_bit) || \ REQUIRED_MASK_CHECK || \ - BUILD_BUG_ON_ZERO(NCAPINTS != 19)) + BUILD_BUG_ON_ZERO(NCAPINTS != 20)) #define DISABLED_MASK_BIT_SET(feature_bit) \ ( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 0, feature_bit) || \ @@ -112,7 +113,7 @@ extern const char * const x86_bug_flags[NBUGINTS*32]; CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) || \ CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 18, feature_bit) || \ DISABLED_MASK_CHECK || \ - BUILD_BUG_ON_ZERO(NCAPINTS != 19)) + BUILD_BUG_ON_ZERO(NCAPINTS != 20)) #define cpu_has(c, bit) \ (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \ diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index f3327cb56edf..42ae9fb06987 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -13,7 +13,7 @@ /* * Defines x86 CPU feature bits */ -#define NCAPINTS 19 /* N 32-bit words worth of info */ +#define NCAPINTS 20 /* N 32-bit words worth of info */ #define NBUGINTS 1 /* N 32-bit bug flags */ /* @@ -238,6 +238,7 @@ /* Intel-defined CPU features, CPUID level 0x00000007:0 (EBX), word 9 */ #define X86_FEATURE_FSGSBASE ( 9*32+ 0) /* RDFSBASE, WRFSBASE, RDGSBASE, WRGSBASE instructions*/ #define X86_FEATURE_TSC_ADJUST ( 9*32+ 1) /* TSC adjustment MSR 0x3B */ +#define X86_FEATURE_SGX ( 9*32+ 2) /* Software Guard Extensions */ #define X86_FEATURE_BMI1 ( 9*32+ 3) /* 1st group bit manipulation extensions */ #define X86_FEATURE_HLE ( 9*32+ 4) /* Hardware Lock Elision */ #define X86_FEATURE_AVX2 ( 9*32+ 5) /* AVX2 instructions */ @@ -369,6 +370,10 @@ #define X86_FEATURE_ARCH_CAPABILITIES (18*32+29) /* IA32_ARCH_CAPABILITIES MSR (Intel) */ #define X86_FEATURE_SPEC_CTRL_SSBD (18*32+31) /* "" Speculative Store Bypass Disable */ +/* Intel-defined SGX features, CPUID level 0x00000012:0 (EAX), word 19 */ +#define X86_FEATURE_SGX1 (19*32+ 0) /* SGX1 leaf functions */ +#define X86_FEATURE_SGX2 (19*32+ 1) /* SGX2 leaf functions */ + /* * BUG word(s) */ diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h index 4ea8584682f9..dbe534d5153f 100644 --- a/arch/x86/include/asm/disabled-features.h +++ b/arch/x86/include/asm/disabled-features.h @@ -28,13 +28,18 @@ # define DISABLE_CYRIX_ARR (1<<(X86_FEATURE_CYRIX_ARR & 31)) # define DISABLE_CENTAUR_MCR (1<<(X86_FEATURE_CENTAUR_MCR & 31)) # define DISABLE_PCID 0 +# define DISABLE_SGX1 0 +# define DISABLE_SGX2 0 #else # define DISABLE_VME 0 # define DISABLE_K6_MTRR 0 # define DISABLE_CYRIX_ARR 0 # define DISABLE_CENTAUR_MCR 0 # define DISABLE_PCID (1<<(X86_FEATURE_PCID & 31)) -#endif /* CONFIG_X86_64 */ +# define DISABLE_SGX1 (1<<(X86_FEATURE_SGX1 & 31)) +# define DISABLE_SGX2 (1<<(X86_FEATURE_SGX2 & 31)) + #endif /* CONFIG_X86_64 */ + #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS # define DISABLE_PKU 0 @@ -56,6 +61,12 @@ # define DISABLE_PTI (1 << (X86_FEATURE_PTI & 31)) #endif +#ifdef CONFIG_INTEL_SGX +# define DISABLE_SGX 0 +#else +# define DISABLE_SGX (1 << (X86_FEATURE_SGX & 31)) +#endif + /* * Make sure to add features to the correct mask */ @@ -68,7 +79,7 @@ #define DISABLED_MASK6 0 #define DISABLED_MASK7 (DISABLE_PTI) #define DISABLED_MASK8 0 -#define DISABLED_MASK9 (DISABLE_SMAP) +#define DISABLED_MASK9 (DISABLE_SMAP|DISABLE_SGX) #define DISABLED_MASK10 0 #define DISABLED_MASK11 0 #define DISABLED_MASK12 0 @@ -78,6 +89,7 @@ #define DISABLED_MASK16 (DISABLE_PKU|DISABLE_OSPKE|DISABLE_LA57|DISABLE_UMIP) #define DISABLED_MASK17 0 #define DISABLED_MASK18 0 -#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 19) +#define DISABLED_MASK19 (DISABLE_SGX1|DISABLE_SGX2) +#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 20) #endif /* _ASM_X86_DISABLED_FEATURES_H */ diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index d5e517d1c3dd..e190293c8923 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -566,6 +566,7 @@ #define FEAT_CTL_LOCKED BIT(0) #define FEAT_CTL_VMX_ENABLED_INSIDE_SMX BIT(1) #define FEAT_CTL_VMX_ENABLED_OUTSIDE_SMX BIT(2) +#define FEAT_CTL_SGX_ENABLED BIT(18) #define FEAT_CTL_LMCE_ENABLED BIT(20) #define MSR_IA32_TSC_ADJUST 0x0000003b diff --git a/arch/x86/include/asm/required-features.h b/arch/x86/include/asm/required-features.h index 6847d85400a8..039e58be2fe6 100644 --- a/arch/x86/include/asm/required-features.h +++ b/arch/x86/include/asm/required-features.h @@ -101,6 +101,6 @@ #define REQUIRED_MASK16 0 #define REQUIRED_MASK17 0 #define REQUIRED_MASK18 0 -#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 19) +#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 20) #endif /* _ASM_X86_REQUIRED_FEATURES_H */ diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 52c9bfbbdb2a..db0c676b2eb0 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -915,6 +915,10 @@ void get_cpu_cap(struct cpuinfo_x86 *c) c->x86_capability[CPUID_D_1_EAX] = eax; } + /* Additional Intel-defined SGX flags: level 0x00000012 */ + if (c->cpuid_level >= 0x00000012) + c->x86_capability[CPUID_12_EAX] = cpuid_eax(0x00000012); + /* AMD-defined flags: level 0x80000001 */ eax = cpuid_eax(0x80000000); c->extended_cpuid_level = eax; diff --git a/tools/arch/x86/include/asm/cpufeatures.h b/tools/arch/x86/include/asm/cpufeatures.h index f3327cb56edf..42ae9fb06987 100644 --- a/tools/arch/x86/include/asm/cpufeatures.h +++ b/tools/arch/x86/include/asm/cpufeatures.h @@ -13,7 +13,7 @@ /* * Defines x86 CPU feature bits */ -#define NCAPINTS 19 /* N 32-bit words worth of info */ +#define NCAPINTS 20 /* N 32-bit words worth of info */ #define NBUGINTS 1 /* N 32-bit bug flags */ /* @@ -238,6 +238,7 @@ /* Intel-defined CPU features, CPUID level 0x00000007:0 (EBX), word 9 */ #define X86_FEATURE_FSGSBASE ( 9*32+ 0) /* RDFSBASE, WRFSBASE, RDGSBASE, WRGSBASE instructions*/ #define X86_FEATURE_TSC_ADJUST ( 9*32+ 1) /* TSC adjustment MSR 0x3B */ +#define X86_FEATURE_SGX ( 9*32+ 2) /* Software Guard Extensions */ #define X86_FEATURE_BMI1 ( 9*32+ 3) /* 1st group bit manipulation extensions */ #define X86_FEATURE_HLE ( 9*32+ 4) /* Hardware Lock Elision */ #define X86_FEATURE_AVX2 ( 9*32+ 5) /* AVX2 instructions */ @@ -369,6 +370,10 @@ #define X86_FEATURE_ARCH_CAPABILITIES (18*32+29) /* IA32_ARCH_CAPABILITIES MSR (Intel) */ #define X86_FEATURE_SPEC_CTRL_SSBD (18*32+31) /* "" Speculative Store Bypass Disable */ +/* Intel-defined SGX features, CPUID level 0x00000012:0 (EAX), word 19 */ +#define X86_FEATURE_SGX1 (19*32+ 0) /* SGX1 leaf functions */ +#define X86_FEATURE_SGX2 (19*32+ 1) /* SGX2 leaf functions */ + /* * BUG word(s) */ From patchwork Tue Apr 21 21:52:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502339 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0FBC91575 for ; Tue, 21 Apr 2020 21:54:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 01D152074B for ; Tue, 21 Apr 2020 21:54:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726420AbgDUVxm (ORCPT ); Tue, 21 Apr 2020 17:53:42 -0400 Received: from mga14.intel.com ([192.55.52.115]:20261 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726385AbgDUVxk (ORCPT ); Tue, 21 Apr 2020 17:53:40 -0400 IronPort-SDR: RbGyFs/7jbOgIR20s7660khGmaYKSBE/pkJFBt0pQORzp6UgyFI5RQEdkj/IV9B0Z4wnMPoJeX 2F73jVZNMvCA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:53:39 -0700 IronPort-SDR: 4K4/jwnQZNRET8VvQQQiskThnIWwFLbVnLbkZw9JizjxbfJEs4drCHZftpoMi4ewatpGVfkS2w LIPBO7iCqT3Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260536" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:53:34 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Jarkko Sakkinen Subject: [PATCH v29 03/20] x86/cpufeatures: x86/msr: Intel SGX Launch Control hardware bits Date: Wed, 22 Apr 2020 00:52:59 +0300 Message-Id: <20200421215316.56503-4-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org From: Sean Christopherson Add X86_FEATURE_SGX_LC, which informs whether or not the CPU supports SGX Launch Control. Add MSR_IA32_SGXLEPUBKEYHASH{0, 1, 2, 3}, which when combined contain a SHA256 hash of a 3072-bit RSA public key. SGX backed software packages, so called enclaves, are always signed. All enclaves signed with the public key are unconditionally allowed to initialize. [1] Add FEATURE_CONTROL_SGX_LE_WR bit of the feature control MSR, which informs whether the formentioned MSRs are writable or not. If the bit is off, the public key MSRs are read-only for the OS. If the MSRs are read-only, the platform must provide a launch enclave (LE). LE can create cryptographic tokens for other enclaves that they can pass together with their signature to the ENCLS(EINIT) opcode, which is used to initialize enclaves. Linux is unlikely to support the locked configuration because it takes away the control of the launch decisions from the kernel. [1] Intel SDM: 38.1.4 Intel SGX Launch Control Configuration Signed-off-by: Sean Christopherson Co-developed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/include/asm/msr-index.h | 7 +++++++ 2 files changed, 8 insertions(+) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 42ae9fb06987..bc5ad93cbeb6 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -350,6 +350,7 @@ #define X86_FEATURE_CLDEMOTE (16*32+25) /* CLDEMOTE instruction */ #define X86_FEATURE_MOVDIRI (16*32+27) /* MOVDIRI instruction */ #define X86_FEATURE_MOVDIR64B (16*32+28) /* MOVDIR64B instruction */ +#define X86_FEATURE_SGX_LC (16*32+30) /* Software Guard Extensions Launch Control */ /* AMD-defined CPU features, CPUID level 0x80000007 (EBX), word 17 */ #define X86_FEATURE_OVERFLOW_RECOV (17*32+ 0) /* MCA overflow recovery support */ diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index e190293c8923..bae17ea2c8fe 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -566,6 +566,7 @@ #define FEAT_CTL_LOCKED BIT(0) #define FEAT_CTL_VMX_ENABLED_INSIDE_SMX BIT(1) #define FEAT_CTL_VMX_ENABLED_OUTSIDE_SMX BIT(2) +#define FEAT_CTL_SGX_LC_ENABLED BIT(17) #define FEAT_CTL_SGX_ENABLED BIT(18) #define FEAT_CTL_LMCE_ENABLED BIT(20) @@ -586,6 +587,12 @@ #define MSR_IA32_UCODE_WRITE 0x00000079 #define MSR_IA32_UCODE_REV 0x0000008b +/* Intel SGX Launch Enclave Public Key Hash MSRs */ +#define MSR_IA32_SGXLEPUBKEYHASH0 0x0000008C +#define MSR_IA32_SGXLEPUBKEYHASH1 0x0000008D +#define MSR_IA32_SGXLEPUBKEYHASH2 0x0000008E +#define MSR_IA32_SGXLEPUBKEYHASH3 0x0000008F + #define MSR_IA32_SMM_MONITOR_CTL 0x0000009b #define MSR_IA32_SMBASE 0x0000009e From patchwork Tue Apr 21 21:53:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502319 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 688271575 for ; Tue, 21 Apr 2020 21:54:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 596F720724 for ; Tue, 21 Apr 2020 21:54:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726489AbgDUVxu (ORCPT ); Tue, 21 Apr 2020 17:53:50 -0400 Received: from mga09.intel.com ([134.134.136.24]:43046 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726421AbgDUVxp (ORCPT ); Tue, 21 Apr 2020 17:53:45 -0400 IronPort-SDR: XG8yASRAQZbywCyBUcRIDTQHqrT0kFHP7Mo4wDDrrxTNp3f1PSh2Fv30GXWYLasa5orA6VHMNB /7zumeyPQqAA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:53:44 -0700 IronPort-SDR: 2y6YPe61+nOLxCseZs1ruUbkEDDO7CyVk49dem1kKqeoeuyvxYNHpLhUuSwZy+I59Qs1axj814 1fxV0Y8jBP/A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260566" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:53:40 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Jarkko Sakkinen Subject: [PATCH v29 04/20] x86/mm: x86/sgx: Signal SIGSEGV with PF_SGX Date: Wed, 22 Apr 2020 00:53:00 +0300 Message-Id: <20200421215316.56503-5-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org From: Sean Christopherson Include SGX bit to the PF error codes and throw SIGSEGV with PF_SGX when a #PF with SGX set happens. CPU throws a #PF with the SGX bit in the event of Enclave Page Cache Map (EPCM) conflict. The EPCM is a CPU-internal table, which describes the properties for a enclave page. Enclaves are measured and signed software entities, which SGX hosts. [1] Although the primary purpose of the EPCM conflict checks is to prevent malicious accesses to an enclave, an illegit access can happen also for legit reasons. All SGX reserved memory, including EPCM is encrypted with a transient key that does not survive from the power transition. Throwing a SIGSEGV allows user space software react when this happens (e.g. rec-create the enclave, which was invalidated). [1] Intel SDM: 36.5.1 Enclave Page Cache Map (EPCM) Signed-off-by: Sean Christopherson Signed-off-by: Jarkko Sakkinen --- arch/x86/include/asm/traps.h | 1 + arch/x86/mm/fault.c | 13 +++++++++++++ 2 files changed, 14 insertions(+) diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index ffa0dc8a535e..bb8d5ae74dbc 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -174,5 +174,6 @@ enum x86_pf_error_code { X86_PF_RSVD = 1 << 3, X86_PF_INSTR = 1 << 4, X86_PF_PK = 1 << 5, + X86_PF_SGX = 1 << 15, }; #endif /* _ASM_X86_TRAPS_H */ diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index fa4ea09593ab..dee9504cde79 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1179,6 +1179,19 @@ access_error(unsigned long error_code, struct vm_area_struct *vma) if (error_code & X86_PF_PK) return 1; + /* + * Access is blocked by the Enclave Page Cache Map (EPCM), i.e. the + * access is allowed by the PTE but not the EPCM. This usually happens + * when the EPCM is yanked out from under us, e.g. by hardware after a + * suspend/resume cycle. In any case, software, i.e. the kernel, can't + * fix the source of the fault as the EPCM can't be directly modified by + * software. Handle the fault as an access error in order to signal + * userspace so that userspace can rebuild their enclave(s), even though + * userspace may not have actually violated access permissions. + */ + if (unlikely(error_code & X86_PF_SGX)) + return 1; + /* * Make sure to check the VMA so that we do not perform * faults just to hit a X86_PF_PK as soon as we fill in a From patchwork Tue Apr 21 21:53:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502335 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3E580913 for ; Tue, 21 Apr 2020 21:54:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2C3AB2072D for ; Tue, 21 Apr 2020 21:54:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726515AbgDUVyC (ORCPT ); Tue, 21 Apr 2020 17:54:02 -0400 Received: from mga04.intel.com ([192.55.52.120]:33433 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726475AbgDUVx6 (ORCPT ); Tue, 21 Apr 2020 17:53:58 -0400 IronPort-SDR: YjcnxT1nSLwpos5ZVAfjKgJQlEibAoSyTavCfZBp9ecX/VMl+SghGRYbyndjaH8A6zUe1nc6KT sos9CpFHlPwg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:53:50 -0700 IronPort-SDR: rd3H8TrLrVxCQSh3F/RMsW2aXkCyCYHsHisXniTFkiZex0PAeLF0PaEjPJzX+35B1c0pwUiZ/B Oi13tMQ/Nogw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260583" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:53:45 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Jarkko Sakkinen Subject: [PATCH v29 05/20] x86/sgx: Add SGX microarchitectural data structures Date: Wed, 22 Apr 2020 00:53:01 +0300 Message-Id: <20200421215316.56503-6-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org Define the SGX microarchitectural data structures used by various SGX opcodes. This is not an exhaustive representation of all SGX data structures but only those needed by the kernel. The data structures are described in: Intel SDM: 37.6 INTEL® SGX DATA STRUCTURES OVERVIEW Signed-off-by: Jarkko Sakkinen --- arch/x86/kernel/cpu/sgx/arch.h | 343 +++++++++++++++++++++++++++++++++ 1 file changed, 343 insertions(+) create mode 100644 arch/x86/kernel/cpu/sgx/arch.h diff --git a/arch/x86/kernel/cpu/sgx/arch.h b/arch/x86/kernel/cpu/sgx/arch.h new file mode 100644 index 000000000000..ddae55e9d4d8 --- /dev/null +++ b/arch/x86/kernel/cpu/sgx/arch.h @@ -0,0 +1,343 @@ +/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */ +/** + * Copyright(c) 2016-18 Intel Corporation. + * + * Contains data structures defined by the SGX architecture. Data structures + * defined by the Linux software stack should not be placed here. + */ +#ifndef _ASM_X86_SGX_ARCH_H +#define _ASM_X86_SGX_ARCH_H + +#include +#include + +#define SGX_CPUID 0x12 +#define SGX_CPUID_FIRST_VARIABLE_SUB_LEAF 2 + +/** + * enum sgx_return_code - The return code type for ENCLS, ENCLU and ENCLV + * %SGX_NOT_TRACKED: Previous ETRACK's shootdown sequence has not + * been completed yet. + * %SGX_INVALID_EINITTOKEN: EINITTOKEN is invalid and enclave signer's + * public key does not match IA32_SGXLEPUBKEYHASH. + * %SGX_UNMASKED_EVENT: An unmasked event, e.g. INTR, was received + */ +enum sgx_return_code { + SGX_NOT_TRACKED = 11, + SGX_INVALID_EINITTOKEN = 16, + SGX_UNMASKED_EVENT = 128, +}; + +/** + * enum sgx_sub_leaf_types - SGX CPUID variable sub-leaf types + * %SGX_CPUID_SUB_LEAF_INVALID: Indicates this sub-leaf is invalid. + * %SGX_CPUID_SUB_LEAF_EPC_SECTION: Sub-leaf enumerates an EPC section. + */ +enum sgx_sub_leaf_types { + SGX_CPUID_SUB_LEAF_INVALID = 0x0, + SGX_CPUID_SUB_LEAF_EPC_SECTION = 0x1, +}; + +#define SGX_CPUID_SUB_LEAF_TYPE_MASK GENMASK(3, 0) + +#define SGX_MODULUS_SIZE 384 + +/** + * enum sgx_miscselect - additional information to an SSA frame + * %SGX_MISC_EXINFO: Report #PF or #GP to the SSA frame. + * + * Save State Area (SSA) is a stack inside the enclave used to store processor + * state when an exception or interrupt occurs. This enum defines additional + * information stored to an SSA frame. + */ +enum sgx_miscselect { + SGX_MISC_EXINFO = BIT(0), +}; + +#define SGX_MISC_RESERVED_MASK GENMASK_ULL(63, 1) + +#define SGX_SSA_GPRS_SIZE 184 +#define SGX_SSA_MISC_EXINFO_SIZE 16 + +/** + * enum sgx_attributes - the attributes field in &struct sgx_secs + * %SGX_ATTR_INIT: Enclave can be entered (is initialized). + * %SGX_ATTR_DEBUG: Allow ENCLS(EDBGRD) and ENCLS(EDBGWR). + * %SGX_ATTR_MODE64BIT: Tell that this a 64-bit enclave. + * %SGX_ATTR_PROVISIONKEY: Allow to use provisioning keys for remote + * attestation. + * %SGX_ATTR_KSS: Allow to use key separation and sharing (KSS). + * %SGX_ATTR_EINITTOKENKEY: Allow to use token signing key that is used to + * sign cryptographic tokens that can be passed to + * EINIT as an authorization to run an enclave. + */ +enum sgx_attribute { + SGX_ATTR_INIT = BIT(0), + SGX_ATTR_DEBUG = BIT(1), + SGX_ATTR_MODE64BIT = BIT(2), + SGX_ATTR_PROVISIONKEY = BIT(4), + SGX_ATTR_EINITTOKENKEY = BIT(5), + SGX_ATTR_KSS = BIT(7), +}; + +#define SGX_ATTR_RESERVED_MASK (BIT_ULL(3) | BIT_ULL(6) | GENMASK_ULL(63, 8)) +#define SGX_ATTR_ALLOWED_MASK (SGX_ATTR_DEBUG | SGX_ATTR_MODE64BIT | \ + SGX_ATTR_KSS) + +/** + * struct sgx_secs - SGX Enclave Control Structure (SECS) + * @size: size of the address space + * @base: base address of the address space + * @ssa_frame_size: size of an SSA frame + * @miscselect: additional information stored to an SSA frame + * @attributes: attributes for enclave + * @xfrm: XSave-Feature Request Mask (subset of XCR0) + * @mrenclave: SHA256-hash of the enclave contents + * @mrsigner: SHA256-hash of the public key used to sign the SIGSTRUCT + * @config_id: a user-defined value that is used in key derivation + * @isv_prod_id: a user-defined value that is used in key derivation + * @isv_svn: a user-defined value that is used in key derivation + * @config_svn: a user-defined value that is used in key derivation + * + * SGX Enclave Control Structure (SECS) is a special enclave page that is not + * visible in the address space. In fact, this structure defines the address + * range and other global attributes for the enclave and it is the first EPC + * page created for any enclave. It is moved from a temporary buffer to an EPC + * by the means of ENCLS(ECREATE) leaf. + */ +struct sgx_secs { + u64 size; + u64 base; + u32 ssa_frame_size; + u32 miscselect; + u8 reserved1[24]; + u64 attributes; + u64 xfrm; + u32 mrenclave[8]; + u8 reserved2[32]; + u32 mrsigner[8]; + u8 reserved3[32]; + u32 config_id[16]; + u16 isv_prod_id; + u16 isv_svn; + u16 config_svn; + u8 reserved4[3834]; +} __packed; + +/** + * enum sgx_tcs_flags - execution flags for TCS + * %SGX_TCS_DBGOPTIN: If enabled allows single-stepping and breakpoints + * inside an enclave. It is cleared by EADD but can + * be set later with EDBGWR. + */ +enum sgx_tcs_flags { + SGX_TCS_DBGOPTIN = 0x01, +}; + +#define SGX_TCS_RESERVED_MASK GENMASK_ULL(63, 1) +#define SGX_TCS_RESERVED_SIZE 4024 + +/** + * struct sgx_tcs - Thread Control Structure (TCS) + * @state: used to mark an entered TCS + * @flags: execution flags (cleared by EADD) + * @ssa_offset: SSA stack offset relative to the enclave base + * @ssa_index: the current SSA frame index (cleard by EADD) + * @nr_ssa_frames: the number of frame in the SSA stack + * @entry_offset: entry point offset relative to the enclave base + * @exit_addr: address outside the enclave to exit on an exception or + * interrupt + * @fs_offset: offset relative to the enclave base to become FS + * segment inside the enclave + * @gs_offset: offset relative to the enclave base to become GS + * segment inside the enclave + * @fs_limit: size to become a new FS-limit (only 32-bit enclaves) + * @gs_limit: size to become a new GS-limit (only 32-bit enclaves) + * + * Thread Control Structure (TCS) is an enclave page visible in its address + * space that defines an entry point inside the enclave. A thread enters inside + * an enclave by supplying address of TCS to ENCLU(EENTER). A TCS can be entered + * by only one thread at a time. + */ +struct sgx_tcs { + u64 state; + u64 flags; + u64 ssa_offset; + u32 ssa_index; + u32 nr_ssa_frames; + u64 entry_offset; + u64 exit_addr; + u64 fs_offset; + u64 gs_offset; + u32 fs_limit; + u32 gs_limit; + u8 reserved[SGX_TCS_RESERVED_SIZE]; +} __packed; + +/** + * struct sgx_pageinfo - an enclave page descriptor + * @addr: address of the enclave page + * @contents: pointer to the page contents + * @metadata: pointer either to a SECINFO or PCMD instance + * @secs: address of the SECS page + */ +struct sgx_pageinfo { + u64 addr; + u64 contents; + u64 metadata; + u64 secs; +} __packed __aligned(32); + + +/** + * enum sgx_page_type - bits in the SECINFO flags defining the page type + * %SGX_PAGE_TYPE_SECS: a SECS page + * %SGX_PAGE_TYPE_TCS: a TCS page + * %SGX_PAGE_TYPE_REG: a regular page + * %SGX_PAGE_TYPE_VA: a VA page + * %SGX_PAGE_TYPE_TRIM: a page in trimmed state + */ +enum sgx_page_type { + SGX_PAGE_TYPE_SECS, + SGX_PAGE_TYPE_TCS, + SGX_PAGE_TYPE_REG, + SGX_PAGE_TYPE_VA, + SGX_PAGE_TYPE_TRIM, +}; + +#define SGX_NR_PAGE_TYPES 5 +#define SGX_PAGE_TYPE_MASK GENMASK(7, 0) + +/** + * enum sgx_secinfo_flags - the flags field in &struct sgx_secinfo + * %SGX_SECINFO_R: allow read + * %SGX_SECINFO_W: allow write + * %SGX_SECINFO_X: allow execution + * %SGX_SECINFO_SECS: a SECS page + * %SGX_SECINFO_TCS: a TCS page + * %SGX_SECINFO_REG: a regular page + * %SGX_SECINFO_VA: a VA page + * %SGX_SECINFO_TRIM: a page in trimmed state + */ +enum sgx_secinfo_flags { + SGX_SECINFO_R = BIT(0), + SGX_SECINFO_W = BIT(1), + SGX_SECINFO_X = BIT(2), + SGX_SECINFO_SECS = (SGX_PAGE_TYPE_SECS << 8), + SGX_SECINFO_TCS = (SGX_PAGE_TYPE_TCS << 8), + SGX_SECINFO_REG = (SGX_PAGE_TYPE_REG << 8), + SGX_SECINFO_VA = (SGX_PAGE_TYPE_VA << 8), + SGX_SECINFO_TRIM = (SGX_PAGE_TYPE_TRIM << 8), +}; + +#define SGX_SECINFO_PERMISSION_MASK GENMASK_ULL(2, 0) +#define SGX_SECINFO_PAGE_TYPE_MASK (SGX_PAGE_TYPE_MASK << 8) +#define SGX_SECINFO_RESERVED_MASK ~(SGX_SECINFO_PERMISSION_MASK | \ + SGX_SECINFO_PAGE_TYPE_MASK) + +/** + * struct sgx_secinfo - describes attributes of an EPC page + * @flags: permissions and type + * + * Used together with ENCLS leaves that add or modify an EPC page to an + * enclave to define page permissions and type. + */ +struct sgx_secinfo { + u64 flags; + u8 reserved[56]; +} __packed __aligned(64); + +#define SGX_PCMD_RESERVED_SIZE 40 + +/** + * struct sgx_pcmd - Paging Crypto Metadata (PCMD) + * @enclave_id: enclave identifier + * @mac: MAC over PCMD, page contents and isvsvn + * + * PCMD is stored for every swapped page to the regular memory. When ELDU loads + * the page back it recalculates the MAC by using a isvsvn number stored in a + * VA page. Together these two structures bring integrity and rollback + * protection. + */ +struct sgx_pcmd { + struct sgx_secinfo secinfo; + u64 enclave_id; + u8 reserved[SGX_PCMD_RESERVED_SIZE]; + u8 mac[16]; +} __packed __aligned(128); + +#define SGX_SIGSTRUCT_RESERVED1_SIZE 84 +#define SGX_SIGSTRUCT_RESERVED2_SIZE 20 +#define SGX_SIGSTRUCT_RESERVED3_SIZE 32 +#define SGX_SIGSTRUCT_RESERVED4_SIZE 12 + +/** + * struct sgx_sigstruct_header - defines author of the enclave + * @header1: constant byte string + * @vendor: must be either 0x0000 or 0x8086 + * @date: YYYYMMDD in BCD + * @header2: costant byte string + * @swdefined: software defined value + */ +struct sgx_sigstruct_header { + u64 header1[2]; + u32 vendor; + u32 date; + u64 header2[2]; + u32 swdefined; + u8 reserved1[84]; +} __packed; + +/** + * struct sgx_sigstruct_body - defines contents of the enclave + * @miscselect: additional information stored to an SSA frame + * @misc_mask: required miscselect in SECS + * @attributes: attributes for enclave + * @xfrm: XSave-Feature Request Mask (subset of XCR0) + * @attributes_mask: required attributes in SECS + * @xfrm_mask: required XFRM in SECS + * @mrenclave: SHA256-hash of the enclave contents + * @isvprodid: a user-defined value that is used in key derivation + * @isvsvn: a user-defined value that is used in key derivation + */ +struct sgx_sigstruct_body { + u32 miscselect; + u32 misc_mask; + u8 reserved2[20]; + u64 attributes; + u64 xfrm; + u64 attributes_mask; + u64 xfrm_mask; + u8 mrenclave[32]; + u8 reserved3[32]; + u16 isvprodid; + u16 isvsvn; +} __packed; + +/** + * struct sgx_sigstruct - an enclave signature + * @header: defines author of the enclave + * @modulus: the modulus of the public key + * @exponent: the exponent of the public key + * @signature: the signature calculated over the fields except modulus, + * @body: defines contents of the enclave + * @q1: a value used in RSA signature verification + * @q2: a value used in RSA signature verification + * + * Header and body are the parts that are actual signed. The remaining fields + * define the signature of the enclave. + */ +struct sgx_sigstruct { + struct sgx_sigstruct_header header; + u8 modulus[SGX_MODULUS_SIZE]; + u32 exponent; + u8 signature[SGX_MODULUS_SIZE]; + struct sgx_sigstruct_body body; + u8 reserved4[12]; + u8 q1[SGX_MODULUS_SIZE]; + u8 q2[SGX_MODULUS_SIZE]; +} __packed; + +#define SGX_LAUNCH_TOKEN_SIZE 304 + +#endif /* _ASM_X86_SGX_ARCH_H */ From patchwork Tue Apr 21 21:53:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502331 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7B798913 for ; Tue, 21 Apr 2020 21:54:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6E42B2072D for ; Tue, 21 Apr 2020 21:54:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726519AbgDUVyC (ORCPT ); Tue, 21 Apr 2020 17:54:02 -0400 Received: from mga11.intel.com ([192.55.52.93]:58181 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726510AbgDUVx5 (ORCPT ); Tue, 21 Apr 2020 17:53:57 -0400 IronPort-SDR: 5bTaIXELIyeYsP8M2EKCaMIkQtH8dNR2z3qLTr3mAjQM5jwwrIItgV9XW2qbo9TVNK/UJZ4rf2 mZ9kLxBi8pJg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:53:56 -0700 IronPort-SDR: fp5K/rrbUpgWfIZHMKWIU5E7y79Bh5cFwPtacaTBZvP9LAWGBGQk6Rd96WOn6JNQ1tLzw1Z+a2 FMjBFiYFq8bg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260601" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:53:51 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Jarkko Sakkinen Subject: [PATCH v29 06/20] x86/sgx: Add wrappers for ENCLS leaf functions Date: Wed, 22 Apr 2020 00:53:02 +0300 Message-Id: <20200421215316.56503-7-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org ENCLS is a ring 0 instruction, which contains a set of leaf functions for managing an enclave. Enclaves are measured and signed software entities, which are protected by asserting the outside memory accesses and memory encryption. Add a two-layer macro system along with an encoding scheme to allow wrappers to return trap numbers along ENCLS-specific error codes. The bottom layer of the macro system splits between the leafs that return an error code and those that do not. The second layer generates the correct input/output annotations based on the number of operands for each leaf function. ENCLS leaf functions are documented in Intel SDM: 36.6 ENCLAVE INSTRUCTIONS AND INTEL® Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson Signed-off-by: Jarkko Sakkinen --- arch/x86/kernel/cpu/sgx/encls.h | 239 ++++++++++++++++++++++++++++++++ 1 file changed, 239 insertions(+) create mode 100644 arch/x86/kernel/cpu/sgx/encls.h diff --git a/arch/x86/kernel/cpu/sgx/encls.h b/arch/x86/kernel/cpu/sgx/encls.h new file mode 100644 index 000000000000..376cdedb9a43 --- /dev/null +++ b/arch/x86/kernel/cpu/sgx/encls.h @@ -0,0 +1,239 @@ +/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */ +#ifndef _X86_ENCLS_H +#define _X86_ENCLS_H + +#include +#include +#include +#include +#include +#include +#include +#include "sgx.h" + +enum sgx_encls_leaf { + ECREATE = 0x00, + EADD = 0x01, + EINIT = 0x02, + EREMOVE = 0x03, + EDGBRD = 0x04, + EDGBWR = 0x05, + EEXTEND = 0x06, + ELDU = 0x08, + EBLOCK = 0x09, + EPA = 0x0A, + EWB = 0x0B, + ETRACK = 0x0C, +}; + +/** + * ENCLS_FAULT_FLAG - flag signifying an ENCLS return code is a trapnr + * + * ENCLS has its own (positive value) error codes and also generates + * ENCLS specific #GP and #PF faults. And the ENCLS values get munged + * with system error codes as everything percolates back up the stack. + * Unfortunately (for us), we need to precisely identify each unique + * error code, e.g. the action taken if EWB fails varies based on the + * type of fault and on the exact SGX error code, i.e. we can't simply + * convert all faults to -EFAULT. + * + * To make all three error types coexist, we set bit 30 to identify an + * ENCLS fault. Bit 31 (technically bits N:31) is used to differentiate + * between positive (faults and SGX error codes) and negative (system + * error codes) values. + */ +#define ENCLS_FAULT_FLAG 0x40000000 + +/* Retrieve the encoded trapnr from the specified return code. */ +#define ENCLS_TRAPNR(r) ((r) & ~ENCLS_FAULT_FLAG) + +/* Issue a WARN() about an ENCLS leaf. */ +#define ENCLS_WARN(r, name) { \ + do { \ + int _r = (r); \ + WARN_ONCE(_r, "%s returned %d (0x%x)\n", (name), _r, _r); \ + } while (0); \ +} + +/** + * encls_failed() - Check if an ENCLS leaf function failed + * @ret: the return value of an ENCLS leaf function call + * + * Check if an ENCLS leaf function failed. This happens when the leaf function + * causes a fault that is not caused by an EPCM conflict or when the leaf + * function returns a non-zero value. + */ +static inline bool encls_failed(int ret) +{ + int epcm_trapnr; + + if (boot_cpu_has(X86_FEATURE_SGX2)) + epcm_trapnr = X86_TRAP_PF; + else + epcm_trapnr = X86_TRAP_GP; + + if (ret & ENCLS_FAULT_FLAG) + return ENCLS_TRAPNR(ret) != epcm_trapnr; + + return !!ret; +} + +/** + * __encls_ret_N - encode an ENCLS leaf that returns an error code in EAX + * @rax: leaf number + * @inputs: asm inputs for the leaf + * + * Emit assembly for an ENCLS leaf that returns an error code, e.g. EREMOVE. + * And because SGX isn't complex enough as it is, leafs that return an error + * code also modify flags. + * + * Return: + * 0 on success, + * SGX error code on failure + */ +#define __encls_ret_N(rax, inputs...) \ + ({ \ + int ret; \ + asm volatile( \ + "1: .byte 0x0f, 0x01, 0xcf;\n\t" \ + "2:\n" \ + ".section .fixup,\"ax\"\n" \ + "3: orl $"__stringify(ENCLS_FAULT_FLAG)",%%eax\n" \ + " jmp 2b\n" \ + ".previous\n" \ + _ASM_EXTABLE_FAULT(1b, 3b) \ + : "=a"(ret) \ + : "a"(rax), inputs \ + : "memory", "cc"); \ + ret; \ + }) + +#define __encls_ret_1(rax, rcx) \ + ({ \ + __encls_ret_N(rax, "c"(rcx)); \ + }) + +#define __encls_ret_2(rax, rbx, rcx) \ + ({ \ + __encls_ret_N(rax, "b"(rbx), "c"(rcx)); \ + }) + +#define __encls_ret_3(rax, rbx, rcx, rdx) \ + ({ \ + __encls_ret_N(rax, "b"(rbx), "c"(rcx), "d"(rdx)); \ + }) + +/** + * __encls_N - encode an ENCLS leaf that doesn't return an error code + * @rax: leaf number + * @rbx_out: optional output variable + * @inputs: asm inputs for the leaf + * + * Emit assembly for an ENCLS leaf that does not return an error code, + * e.g. ECREATE. Leaves without error codes either succeed or fault. + * @rbx_out is an optional parameter for use by EDGBRD, which returns + * the the requested value in RBX. + * + * Return: + * 0 on success, + * trapnr with ENCLS_FAULT_FLAG set on fault + */ +#define __encls_N(rax, rbx_out, inputs...) \ + ({ \ + int ret; \ + asm volatile( \ + "1: .byte 0x0f, 0x01, 0xcf;\n\t" \ + " xor %%eax,%%eax;\n" \ + "2:\n" \ + ".section .fixup,\"ax\"\n" \ + "3: orl $"__stringify(ENCLS_FAULT_FLAG)",%%eax\n" \ + " jmp 2b\n" \ + ".previous\n" \ + _ASM_EXTABLE_FAULT(1b, 3b) \ + : "=a"(ret), "=b"(rbx_out) \ + : "a"(rax), inputs \ + : "memory"); \ + ret; \ + }) + +#define __encls_2(rax, rbx, rcx) \ + ({ \ + unsigned long ign_rbx_out; \ + __encls_N(rax, ign_rbx_out, "b"(rbx), "c"(rcx)); \ + }) + +#define __encls_1_1(rax, data, rcx) \ + ({ \ + unsigned long rbx_out; \ + int ret = __encls_N(rax, rbx_out, "c"(rcx)); \ + if (!ret) \ + data = rbx_out; \ + ret; \ + }) + +static inline int __ecreate(struct sgx_pageinfo *pginfo, void *secs) +{ + return __encls_2(ECREATE, pginfo, secs); +} + +static inline int __eextend(void *secs, void *addr) +{ + return __encls_2(EEXTEND, secs, addr); +} + +static inline int __eadd(struct sgx_pageinfo *pginfo, void *addr) +{ + return __encls_2(EADD, pginfo, addr); +} + +static inline int __einit(void *sigstruct, struct sgx_einittoken *einittoken, + void *secs) +{ + return __encls_ret_3(EINIT, sigstruct, secs, einittoken); +} + +static inline int __eremove(void *addr) +{ + return __encls_ret_1(EREMOVE, addr); +} + +static inline int __edbgwr(void *addr, unsigned long *data) +{ + return __encls_2(EDGBWR, *data, addr); +} + +static inline int __edbgrd(void *addr, unsigned long *data) +{ + return __encls_1_1(EDGBRD, *data, addr); +} + +static inline int __etrack(void *addr) +{ + return __encls_ret_1(ETRACK, addr); +} + +static inline int __eldu(struct sgx_pageinfo *pginfo, void *addr, + void *va) +{ + return __encls_ret_3(ELDU, pginfo, addr, va); +} + +static inline int __eblock(void *addr) +{ + return __encls_ret_1(EBLOCK, addr); +} + +static inline int __epa(void *addr) +{ + unsigned long rbx = SGX_PAGE_TYPE_VA; + + return __encls_2(EPA, rbx, addr); +} + +static inline int __ewb(struct sgx_pageinfo *pginfo, void *addr, + void *va) +{ + return __encls_ret_3(EWB, pginfo, addr, va); +} + +#endif /* _X86_ENCLS_H */ From patchwork Tue Apr 21 21:53:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502325 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 73C75913 for ; Tue, 21 Apr 2020 21:54:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66DC82077D for ; Tue, 21 Apr 2020 21:54:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726475AbgDUVyD (ORCPT ); Tue, 21 Apr 2020 17:54:03 -0400 Received: from mga01.intel.com ([192.55.52.88]:30789 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726482AbgDUVyD (ORCPT ); Tue, 21 Apr 2020 17:54:03 -0400 IronPort-SDR: 9ojoTcyK2ZsDfhT0Ut9EPBlnLui6HE42i0KWB25QPPAGTRVrf9ots8SecY+627G+K58qs7DxHK S9mm/PAuG9mg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:54:02 -0700 IronPort-SDR: hUsb/RoZhTdfchhTO8cZvzOIKEB6OKdbHiLeQoq6lX+5UXv9TozGF+rkCDlO1Mqvc1tOx3VJlR s3XqXjM93eSQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260647" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:53:57 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Jarkko Sakkinen Subject: [PATCH v29 07/20] x86/cpu/intel: Detect SGX support Date: Wed, 22 Apr 2020 00:53:03 +0300 Message-Id: <20200421215316.56503-8-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org From: Sean Christopherson Configure SGX as part of feature control MSR initialization and update the associated X86_FEATURE flags accordingly. Because the kernel will require the LE hash MSRs to be writable when running native enclaves, disable X86_FEATURE_SGX (and all derivatives) if SGX Launch Control is not (or cannot) be fully enabled via feature control MSR. The check is done for every CPU, not just BSP, in order to verify that MSR_IA32_FEATURE_CONTROL is correctly configured on all CPUs. The other parts of the kernel, like the enclave driver, expect the same configuration from all CPUs. Note, unlike VMX, clear the X86_FEATURE_SGX* flags for all CPUs if any CPU lacks SGX support as the kernel expects SGX to be available on all CPUs. X86_FEATURE_VMX is intentionally cleared only for the current CPU so that KVM can provide additional information if KVM fails to load, e.g. print which CPU doesn't support VMX. KVM/VMX requires additional per-CPU enabling, e.g. to set CR4.VMXE and do VMXON, and so already has the necessary infrastructure to do per-CPU checks. SGX on the other hand doesn't require additional enabling, so clearing the feature flags on all CPUs means the SGX subsystem doesn't need to manually do support checks on a per-CPU basis. Signed-off-by: Sean Christopherson Co-developed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- arch/x86/kernel/cpu/feat_ctl.c | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/feat_ctl.c b/arch/x86/kernel/cpu/feat_ctl.c index 0268185bef94..ef4ddd6c8630 100644 --- a/arch/x86/kernel/cpu/feat_ctl.c +++ b/arch/x86/kernel/cpu/feat_ctl.c @@ -92,16 +92,35 @@ static void init_vmx_capabilities(struct cpuinfo_x86 *c) } #endif /* CONFIG_X86_VMX_FEATURE_NAMES */ +static void clear_sgx_caps(void) +{ + setup_clear_cpu_cap(X86_FEATURE_SGX); + setup_clear_cpu_cap(X86_FEATURE_SGX_LC); + setup_clear_cpu_cap(X86_FEATURE_SGX1); + setup_clear_cpu_cap(X86_FEATURE_SGX2); +} + void init_ia32_feat_ctl(struct cpuinfo_x86 *c) { bool tboot = tboot_enabled(); + bool enable_sgx; u64 msr; if (rdmsrl_safe(MSR_IA32_FEAT_CTL, &msr)) { clear_cpu_cap(c, X86_FEATURE_VMX); + clear_sgx_caps(); return; } + /* + * Enable SGX if and only if the kernel supports SGX and Launch Control + * is supported, i.e. disable SGX if the LE hash MSRs can't be written. + */ + enable_sgx = cpu_has(c, X86_FEATURE_SGX) && + cpu_has(c, X86_FEATURE_SGX1) && + cpu_has(c, X86_FEATURE_SGX_LC) && + IS_ENABLED(CONFIG_INTEL_SGX); + if (msr & FEAT_CTL_LOCKED) goto update_caps; @@ -123,13 +142,16 @@ void init_ia32_feat_ctl(struct cpuinfo_x86 *c) msr |= FEAT_CTL_VMX_ENABLED_INSIDE_SMX; } + if (enable_sgx) + msr |= FEAT_CTL_SGX_ENABLED | FEAT_CTL_SGX_LC_ENABLED; + wrmsrl(MSR_IA32_FEAT_CTL, msr); update_caps: set_cpu_cap(c, X86_FEATURE_MSR_IA32_FEAT_CTL); if (!cpu_has(c, X86_FEATURE_VMX)) - return; + goto update_sgx; if ( (tboot && !(msr & FEAT_CTL_VMX_ENABLED_INSIDE_SMX)) || (!tboot && !(msr & FEAT_CTL_VMX_ENABLED_OUTSIDE_SMX))) { @@ -142,4 +164,12 @@ void init_ia32_feat_ctl(struct cpuinfo_x86 *c) init_vmx_capabilities(c); #endif } + +update_sgx: + if (!(msr & FEAT_CTL_SGX_ENABLED) || + !(msr & FEAT_CTL_SGX_LC_ENABLED) || !enable_sgx) { + if (enable_sgx) + pr_err_once("SGX disabled by BIOS\n"); + clear_sgx_caps(); + } } From patchwork Tue Apr 21 21:53:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502329 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 686CF1575 for ; Tue, 21 Apr 2020 21:54:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 518F02072D for ; Tue, 21 Apr 2020 21:54:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726557AbgDUVyN (ORCPT ); Tue, 21 Apr 2020 17:54:13 -0400 Received: from mga01.intel.com ([192.55.52.88]:30789 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726541AbgDUVyK (ORCPT ); Tue, 21 Apr 2020 17:54:10 -0400 IronPort-SDR: 1gqMwzL3Xkso+Dyya6dpE0ftAJQ8Y5zvg41mvOf/IT312WY38zyGz2HTZD1UyzEVLRJwK2Uf9P Tgm6p9VI8HGg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:54:08 -0700 IronPort-SDR: zvTeTuFsLXXmNMS7OGlEDpk38K6PTFpLklzdLXs3VUS5xhQ6sQMNqnZH5q+yFaNLORf6mAi0qC TIlo6jJyTiXA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260667" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:54:03 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Serge Ayoun , Jarkko Sakkinen Subject: [PATCH v29 08/20] x86/sgx: Enumerate and track EPC sections Date: Wed, 22 Apr 2020 00:53:04 +0300 Message-Id: <20200421215316.56503-9-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org From: Sean Christopherson Enumerate Enclave Page Cache (EPC) sections via CPUID and add the data structures necessary to track EPC pages so that they can be allocated, freed and managed. As a system may have multiple EPC sections, invoke CPUID on SGX sub-leafs until an invalid leaf is encountered. For simplicity, support a maximum of eight EPC sections. Existing client hardware supports only a single section, while upcoming server hardware will support at most eight sections. Bounding the number of sections also allows the section ID to be embedded along with a page's offset in a single unsigned long, enabling easy retrieval of both the VA and PA for a given page. Signed-off-by: Sean Christopherson Co-developed-by: Serge Ayoun Signed-off-by: Serge Ayoun Co-developed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- arch/x86/Kconfig | 14 +++ arch/x86/kernel/cpu/Makefile | 1 + arch/x86/kernel/cpu/sgx/Makefile | 3 + arch/x86/kernel/cpu/sgx/main.c | 151 ++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/sgx/reclaim.c | 82 ++++++++++++++++ arch/x86/kernel/cpu/sgx/sgx.h | 70 ++++++++++++++ 6 files changed, 321 insertions(+) create mode 100644 arch/x86/kernel/cpu/sgx/Makefile create mode 100644 arch/x86/kernel/cpu/sgx/main.c create mode 100644 arch/x86/kernel/cpu/sgx/reclaim.c create mode 100644 arch/x86/kernel/cpu/sgx/sgx.h diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index beea77046f9b..8bbb4313fae3 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1950,6 +1950,20 @@ config X86_INTEL_TSX_MODE_AUTO side channel attacks- equals the tsx=auto command line parameter. endchoice +config INTEL_SGX + bool "Intel SGX" + depends on X86_64 && CPU_SUP_INTEL + select SRCU + select MMU_NOTIFIER + help + Intel(R) SGX is a set of CPU instructions that can be used by + applications to set aside private regions of code and data, referred + to as enclaves. An enclave's private memory can only be accessed by + code running within the enclave. Accesses from outside the enclave, + including other enclaves, are disallowed by hardware. + + If unsure, say N. + config EFI bool "EFI runtime service support" depends on ACPI diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile index 7dc4ad68eb41..45534fb81007 100644 --- a/arch/x86/kernel/cpu/Makefile +++ b/arch/x86/kernel/cpu/Makefile @@ -46,6 +46,7 @@ obj-$(CONFIG_X86_MCE) += mce/ obj-$(CONFIG_MTRR) += mtrr/ obj-$(CONFIG_MICROCODE) += microcode/ obj-$(CONFIG_X86_CPU_RESCTRL) += resctrl/ +obj-$(CONFIG_INTEL_SGX) += sgx/ obj-$(CONFIG_X86_LOCAL_APIC) += perfctr-watchdog.o diff --git a/arch/x86/kernel/cpu/sgx/Makefile b/arch/x86/kernel/cpu/sgx/Makefile new file mode 100644 index 000000000000..2dec75916a5e --- /dev/null +++ b/arch/x86/kernel/cpu/sgx/Makefile @@ -0,0 +1,3 @@ +obj-y += \ + main.o \ + reclaim.o diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c new file mode 100644 index 000000000000..38424c1e8341 --- /dev/null +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -0,0 +1,151 @@ +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) +// Copyright(c) 2016-17 Intel Corporation. + +#include +#include +#include +#include +#include +#include +#include +#include "encls.h" + +struct sgx_epc_section sgx_epc_sections[SGX_MAX_EPC_SECTIONS]; +int sgx_nr_epc_sections; + +static void __init sgx_free_epc_section(struct sgx_epc_section *section) +{ + struct sgx_epc_page *page; + + while (!list_empty(§ion->page_list)) { + page = list_first_entry(§ion->page_list, + struct sgx_epc_page, list); + list_del(&page->list); + kfree(page); + } + + while (!list_empty(§ion->unsanitized_page_list)) { + page = list_first_entry(§ion->unsanitized_page_list, + struct sgx_epc_page, list); + list_del(&page->list); + kfree(page); + } + + memunmap(section->va); +} + +static bool __init sgx_alloc_epc_section(u64 addr, u64 size, + unsigned long index, + struct sgx_epc_section *section) +{ + unsigned long nr_pages = size >> PAGE_SHIFT; + struct sgx_epc_page *page; + unsigned long i; + + section->va = memremap(addr, size, MEMREMAP_WB); + if (!section->va) + return false; + + section->pa = addr; + spin_lock_init(§ion->lock); + INIT_LIST_HEAD(§ion->page_list); + INIT_LIST_HEAD(§ion->unsanitized_page_list); + + for (i = 0; i < nr_pages; i++) { + page = kzalloc(sizeof(*page), GFP_KERNEL); + if (!page) + goto err_out; + + page->desc = (addr + (i << PAGE_SHIFT)) | index; + list_add_tail(&page->list, §ion->unsanitized_page_list); + } + + return true; + +err_out: + sgx_free_epc_section(section); + return false; +} + +static void __init sgx_page_cache_teardown(void) +{ + int i; + + for (i = 0; i < sgx_nr_epc_sections; i++) + sgx_free_epc_section(&sgx_epc_sections[i]); +} + +/** + * A section metric is concatenated in a way that @low bits 12-31 define the + * bits 12-31 of the metric and @high bits 0-19 define the bits 32-51 of the + * metric. + */ +static inline u64 __init sgx_calc_section_metric(u64 low, u64 high) +{ + return (low & GENMASK_ULL(31, 12)) + + ((high & GENMASK_ULL(19, 0)) << 32); +} + +static bool __init sgx_page_cache_init(void) +{ + u32 eax, ebx, ecx, edx, type; + u64 pa, size; + int i; + + for (i = 0; i <= ARRAY_SIZE(sgx_epc_sections); i++) { + cpuid_count(SGX_CPUID, i + SGX_CPUID_FIRST_VARIABLE_SUB_LEAF, + &eax, &ebx, &ecx, &edx); + + type = eax & SGX_CPUID_SUB_LEAF_TYPE_MASK; + if (type == SGX_CPUID_SUB_LEAF_INVALID) + break; + + if (type != SGX_CPUID_SUB_LEAF_EPC_SECTION) { + pr_err_once("Unknown EPC section type: %u\n", type); + break; + } + + if (i == ARRAY_SIZE(sgx_epc_sections)) { + pr_warn("No free slot for an EPC section\n"); + break; + } + + pa = sgx_calc_section_metric(eax, ebx); + size = sgx_calc_section_metric(ecx, edx); + + pr_info("EPC section 0x%llx-0x%llx\n", pa, pa + size - 1); + + if (!sgx_alloc_epc_section(pa, size, i, &sgx_epc_sections[i])) { + pr_err("No free memory for an EPC section\n"); + break; + } + + sgx_nr_epc_sections++; + } + + if (!sgx_nr_epc_sections) { + pr_err("There are zero EPC sections.\n"); + return false; + } + + return true; +} + +static void __init sgx_init(void) +{ + if (!boot_cpu_has(X86_FEATURE_SGX)) + return; + + if (!sgx_page_cache_init()) + return; + + if (!sgx_page_reclaimer_init()) + goto err_page_cache; + + return; + +err_page_cache: + sgx_page_cache_teardown(); +} + +arch_initcall(sgx_init); diff --git a/arch/x86/kernel/cpu/sgx/reclaim.c b/arch/x86/kernel/cpu/sgx/reclaim.c new file mode 100644 index 000000000000..215371588a25 --- /dev/null +++ b/arch/x86/kernel/cpu/sgx/reclaim.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) +// Copyright(c) 2016-19 Intel Corporation. + +#include +#include +#include +#include +#include +#include +#include +#include +#include "encls.h" + +struct task_struct *ksgxswapd_tsk; + +static void sgx_sanitize_section(struct sgx_epc_section *section) +{ + struct sgx_epc_page *page; + LIST_HEAD(secs_list); + int ret; + + while (!list_empty(§ion->unsanitized_page_list)) { + if (kthread_should_stop()) + return; + + spin_lock(§ion->lock); + + page = list_first_entry(§ion->unsanitized_page_list, + struct sgx_epc_page, list); + + ret = __eremove(sgx_epc_addr(page)); + if (!ret) + list_move(&page->list, §ion->page_list); + else + list_move_tail(&page->list, &secs_list); + + spin_unlock(§ion->lock); + + cond_resched(); + } +} + +static int ksgxswapd(void *p) +{ + int i; + + set_freezable(); + + /* + * Reset all pages to uninitialized state. Pages could be in initialized + * on kmemexec. + */ + for (i = 0; i < sgx_nr_epc_sections; i++) + sgx_sanitize_section(&sgx_epc_sections[i]); + + /* + * 2nd round for the SECS pages as they cannot be removed when they + * still hold child pages. + */ + for (i = 0; i < sgx_nr_epc_sections; i++) { + sgx_sanitize_section(&sgx_epc_sections[i]); + + /* Should never happen. */ + if (!list_empty(&sgx_epc_sections[i].unsanitized_page_list)) + WARN(1, "EPC section %d has unsanitized pages.\n", i); + } + + return 0; +} + +bool __init sgx_page_reclaimer_init(void) +{ + struct task_struct *tsk; + + tsk = kthread_run(ksgxswapd, NULL, "ksgxswapd"); + if (IS_ERR(tsk)) + return false; + + ksgxswapd_tsk = tsk; + + return true; +} diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h new file mode 100644 index 000000000000..aad30980be32 --- /dev/null +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -0,0 +1,70 @@ +/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */ +#ifndef _X86_SGX_H +#define _X86_SGX_H + +#include +#include +#include +#include +#include +#include +#include "arch.h" + +#undef pr_fmt +#define pr_fmt(fmt) "sgx: " fmt + +struct sgx_epc_page { + unsigned long desc; + struct list_head list; +}; + +/** + * struct sgx_epc_section + * + * The firmware can define multiple chunks of EPC to the different areas of the + * physical memory e.g. for memory areas of the each node. This structure is + * used to store EPC pages for one EPC section and virtual memory area where + * the pages have been mapped. + */ +struct sgx_epc_section { + unsigned long pa; + void *va; + struct list_head page_list; + struct list_head unsanitized_page_list; + spinlock_t lock; +}; + +/** + * enum sgx_epc_page_desc - bits and masks for an EPC page's descriptor + * %SGX_EPC_SECTION_MASK: SGX allows to have multiple EPC sections in the + * physical memory. The existing and near-future + * hardware defines at most eight sections, hence + * three bits to hold a section. + */ +enum sgx_epc_page_desc { + SGX_EPC_SECTION_MASK = GENMASK_ULL(3, 0), + /* bits 12-63 are reserved for the physical page address of the page */ +}; + +#define SGX_MAX_EPC_SECTIONS (SGX_EPC_SECTION_MASK + 1) + +extern struct sgx_epc_section sgx_epc_sections[SGX_MAX_EPC_SECTIONS]; + +static inline struct sgx_epc_section *sgx_epc_section(struct sgx_epc_page *page) +{ + return &sgx_epc_sections[page->desc & SGX_EPC_SECTION_MASK]; +} + +static inline void *sgx_epc_addr(struct sgx_epc_page *page) +{ + struct sgx_epc_section *section = sgx_epc_section(page); + + return section->va + (page->desc & PAGE_MASK) - section->pa; +} + +extern int sgx_nr_epc_sections; +extern struct task_struct *ksgxswapd_tsk; + +bool __init sgx_page_reclaimer_init(void); + +#endif /* _X86_SGX_H */ From patchwork Tue Apr 21 21:53:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502327 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0AEEB1575 for ; Tue, 21 Apr 2020 21:54:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F0709206D9 for ; Tue, 21 Apr 2020 21:54:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726541AbgDUVyR (ORCPT ); Tue, 21 Apr 2020 17:54:17 -0400 Received: from mga11.intel.com ([192.55.52.93]:58195 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726061AbgDUVyN (ORCPT ); Tue, 21 Apr 2020 17:54:13 -0400 IronPort-SDR: RfNI0xMit56K1x23fl5iosl9ZOL72K+2JPJAGz/xQKTxPXO5UJdWfM11ivkZYd48nY09GE8T9H 99xci5khJZNw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:54:13 -0700 IronPort-SDR: 3eO200dsOmdGIAy/UHoenNPlzcwnAsJY4jDWhA/TZGkgNPlHV1YRElY9cJJi++vQe3zBw7BLGq fchZHDfq9AvA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260685" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:54:09 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Jarkko Sakkinen Subject: [PATCH v29 09/20] x86/sgx: Add functions to allocate and free EPC pages Date: Wed, 22 Apr 2020 00:53:05 +0300 Message-Id: <20200421215316.56503-10-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org Add functions for allocating page from Enclave Page Cache (EPC). A page is allocated by going through the EPC sections and returning the first free page. When a page is freed, it might have a valid state, which means that the callee has assigned it to an enclave, which are protected memory ares used to run code protected from outside access. The page is returned back to the invalid state with ENCLS[EREMOVE] [1]. [1] Intel SDM: 40.3 INTEL® SGX SYSTEM LEAF FUNCTION REFERENCE Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson Signed-off-by: Jarkko Sakkinen --- arch/x86/kernel/cpu/sgx/main.c | 60 ++++++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/sgx/sgx.h | 3 ++ 2 files changed, 63 insertions(+) diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index 38424c1e8341..60d82e7537c8 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -13,6 +13,66 @@ struct sgx_epc_section sgx_epc_sections[SGX_MAX_EPC_SECTIONS]; int sgx_nr_epc_sections; +static struct sgx_epc_page *__sgx_try_alloc_page(struct sgx_epc_section *section) +{ + struct sgx_epc_page *page; + + if (list_empty(§ion->page_list)) + return NULL; + + page = list_first_entry(§ion->page_list, struct sgx_epc_page, list); + list_del_init(&page->list); + return page; +} + +/** + * sgx_try_alloc_page() - Allocate an EPC page + * + * Try to grab a page from the free EPC page list. + * + * Return: + * a pointer to a &struct sgx_epc_page instance, + * -errno on error + */ +struct sgx_epc_page *sgx_try_alloc_page(void) +{ + struct sgx_epc_section *section; + struct sgx_epc_page *page; + int i; + + for (i = 0; i < sgx_nr_epc_sections; i++) { + section = &sgx_epc_sections[i]; + spin_lock(§ion->lock); + page = __sgx_try_alloc_page(section); + spin_unlock(§ion->lock); + + if (page) + return page; + } + + return ERR_PTR(-ENOMEM); +} + +/** + * sgx_free_page() - Free an EPC page + * @page: pointer a previously allocated EPC page + * + * EREMOVE an EPC page and insert it back to the list of free pages. + */ +void sgx_free_page(struct sgx_epc_page *page) +{ + struct sgx_epc_section *section = sgx_epc_section(page); + int ret; + + ret = __eremove(sgx_epc_addr(page)); + if (WARN_ONCE(ret, "EREMOVE returned %d (0x%x)", ret, ret)) + return; + + spin_lock(§ion->lock); + list_add_tail(&page->list, §ion->page_list); + spin_unlock(§ion->lock); +} + static void __init sgx_free_epc_section(struct sgx_epc_section *section) { struct sgx_epc_page *page; diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index aad30980be32..aa85f85412d8 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -67,4 +67,7 @@ extern struct task_struct *ksgxswapd_tsk; bool __init sgx_page_reclaimer_init(void); +struct sgx_epc_page *sgx_try_alloc_page(void); +void sgx_free_page(struct sgx_epc_page *page); + #endif /* _X86_SGX_H */ From patchwork Tue Apr 21 21:53:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502337 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F0111913 for ; Tue, 21 Apr 2020 21:54:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E19F920736 for ; Tue, 21 Apr 2020 21:54:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726284AbgDUVyX (ORCPT ); Tue, 21 Apr 2020 17:54:23 -0400 Received: from mga01.intel.com ([192.55.52.88]:30807 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726061AbgDUVyT (ORCPT ); Tue, 21 Apr 2020 17:54:19 -0400 IronPort-SDR: +rbVDL6jOtZmPBAphhcGsXuEFufpLjAWv6WyUsa79smY/4R2BJW9XJCCgZKuTamY/4fsEoce0b g3UbLwnKVdRA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:54:18 -0700 IronPort-SDR: ghzpsa4AHX0Gdq48562kmLrYJwAUNBoCmbpksX3AbBQSbPZcWcW/tHI01priKuznAT+4BBNmAg kzeJUhdgiwIg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260696" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:54:14 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Jarkko Sakkinen Subject: [PATCH v29 10/20] mm: Introduce vm_ops->may_mprotect() Date: Wed, 22 Apr 2020 00:53:06 +0300 Message-Id: <20200421215316.56503-11-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org From: Sean Christopherson Add vm_ops()->may_mprotect() to check additional constrains set by a subsystem for a mprotect() call. Signed-off-by: Sean Christopherson Signed-off-by: Jarkko Sakkinen --- include/linux/mm.h | 2 ++ mm/mprotect.c | 14 +++++++++++--- 2 files changed, 13 insertions(+), 3 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 52269e56c514..ad08eb666e1c 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -464,6 +464,8 @@ struct vm_operations_struct { void (*close)(struct vm_area_struct * area); int (*split)(struct vm_area_struct * area, unsigned long addr); int (*mremap)(struct vm_area_struct * area); + int (*may_mprotect)(struct vm_area_struct *vma, unsigned long start, + unsigned long end, unsigned long prot); vm_fault_t (*fault)(struct vm_fault *vmf); vm_fault_t (*huge_fault)(struct vm_fault *vmf, enum page_entry_size pe_size); diff --git a/mm/mprotect.c b/mm/mprotect.c index 7a8e84f86831..c0cb40e23b43 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -543,13 +543,21 @@ static int do_mprotect_pkey(unsigned long start, size_t len, goto out; } + tmp = vma->vm_end; + if (tmp > end) + tmp = end; + + if (vma->vm_ops && vma->vm_ops->may_mprotect) { + error = vma->vm_ops->may_mprotect(vma, nstart, tmp, + prot); + if (error) + goto out; + } + error = security_file_mprotect(vma, reqprot, prot); if (error) goto out; - tmp = vma->vm_end; - if (tmp > end) - tmp = end; error = mprotect_fixup(vma, &prev, nstart, tmp, newflags); if (error) goto out; From patchwork Tue Apr 21 21:53:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502345 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8B397913 for ; Tue, 21 Apr 2020 21:54:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5CD9C2072D for ; Tue, 21 Apr 2020 21:54:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726378AbgDUVy3 (ORCPT ); Tue, 21 Apr 2020 17:54:29 -0400 Received: from mga17.intel.com ([192.55.52.151]:55794 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726061AbgDUVy2 (ORCPT ); Tue, 21 Apr 2020 17:54:28 -0400 IronPort-SDR: t7QL7dQdCP5ydWDpiCNvq95ApJENQ9rKq9YwzyArZfCLri8x+E1VWGYda57pE95ljkn29/84hg GEmjHXibOBRw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:54:26 -0700 IronPort-SDR: OuKGzCC7TWFoMQb5BztjKk5YynVK0xZPM5FRo+Fhox6vOR/HV9PQlaEAC5+MX3xDRiiNGFMAlB HUscdRtbaqHw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260727" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:54:19 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Jarkko Sakkinen , linux-security-module@vger.kernel.org, Suresh Siddha , Haitao Huang , Jethro Beekman , Chunyang Hui , Jordan Hand Subject: [PATCH v29 11/20] x86/sgx: Linux Enclave Driver Date: Wed, 22 Apr 2020 00:53:07 +0300 Message-Id: <20200421215316.56503-12-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org Intel Software Guard eXtensions (SGX) is a set of CPU instructions that can be used by applications to set aside private regions of code and data. The code outside the SGX hosted software entity is disallowed to access the memory inside the enclave enforced by the CPU. We call these entities as enclaves. This commit implements a driver that provides an ioctl API to construct and run enclaves. Enclaves are constructed from pages residing in reserved physical memory areas. The contents of these pages can only be accessed when they are mapped as part of an enclave, by a hardware thread running inside the enclave. The starting state of an enclave consists of a fixed measured set of pages that are copied to the EPC during the construction process by using ENCLS leaf functions and Software Enclave Control Structure (SECS) that defines the enclave properties. Enclave are constructed by using ENCLS leaf functions ECREATE, EADD and EINIT. ECREATE initializes SECS, EADD copies pages from system memory to the EPC and EINIT check a given signed measurement and moves the enclave into a state ready for execution. An initialized enclave can only be accessed through special Thread Control Structure (TCS) pages by using ENCLU (ring-3 only) leaf EENTER. This leaf function converts a thread into enclave mode and continues the execution in the offset defined by the TCS provided to EENTER. An enclave is exited through syscall, exception, interrupts or by explicitly calling another ENCLU leaf EEXIT. The permissions, which enclave page is added will set the limit for maximum permissions that can be set for mmap() and mprotect(). This will effectively allow to build different security schemes between producers and consumers of enclaves. Later on we can increase granularity with LSM hooks for page addition (i.e. for producers) and mapping of the enclave (i.e. for consumers) Cc: linux-security-module@vger.kernel.org Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson Co-developed-by: Suresh Siddha Signed-off-by: Suresh Siddha Tested-by: Haitao Huang Tested-by: Jethro Beekman Tested-by: Chunyang Hui Tested-by: Jordan Hand Signed-off-by: Jarkko Sakkinen --- .../userspace-api/ioctl/ioctl-number.rst | 1 + arch/x86/include/uapi/asm/sgx.h | 66 ++ arch/x86/kernel/cpu/sgx/Makefile | 3 + arch/x86/kernel/cpu/sgx/driver.c | 194 +++++ arch/x86/kernel/cpu/sgx/driver.h | 30 + arch/x86/kernel/cpu/sgx/encl.c | 332 +++++++++ arch/x86/kernel/cpu/sgx/encl.h | 87 +++ arch/x86/kernel/cpu/sgx/encls.h | 5 +- arch/x86/kernel/cpu/sgx/ioctl.c | 687 ++++++++++++++++++ arch/x86/kernel/cpu/sgx/main.c | 12 +- arch/x86/kernel/cpu/sgx/reclaim.c | 1 + 11 files changed, 1414 insertions(+), 4 deletions(-) create mode 100644 arch/x86/include/uapi/asm/sgx.h create mode 100644 arch/x86/kernel/cpu/sgx/driver.c create mode 100644 arch/x86/kernel/cpu/sgx/driver.h create mode 100644 arch/x86/kernel/cpu/sgx/encl.c create mode 100644 arch/x86/kernel/cpu/sgx/encl.h create mode 100644 arch/x86/kernel/cpu/sgx/ioctl.c diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst index 2e91370dc159..1c54dd2704db 100644 --- a/Documentation/userspace-api/ioctl/ioctl-number.rst +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst @@ -321,6 +321,7 @@ Code Seq# Include File Comments 0xA3 90-9F linux/dtlk.h 0xA4 00-1F uapi/linux/tee.h Generic TEE subsystem +0xA4 00-1F uapi/asm/sgx.h Intel SGX subsystem (a legit conflict as TEE and SGX do not co-exist) 0xAA 00-3F linux/uapi/linux/userfaultfd.h 0xAB 00-1F linux/nbd.h 0xAC 00-1F linux/raw.h diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h new file mode 100644 index 000000000000..5edb08ab8fd0 --- /dev/null +++ b/arch/x86/include/uapi/asm/sgx.h @@ -0,0 +1,66 @@ +/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) WITH Linux-syscall-note */ +/* + * Copyright(c) 2016-19 Intel Corporation. + */ +#ifndef _UAPI_ASM_X86_SGX_H +#define _UAPI_ASM_X86_SGX_H + +#include +#include + +/** + * enum sgx_epage_flags - page control flags + * %SGX_PAGE_MEASURE: Measure the page contents with a sequence of + * ENCLS[EEXTEND] operations. + */ +enum sgx_page_flags { + SGX_PAGE_MEASURE = 0x01, +}; + +#define SGX_MAGIC 0xA4 + +#define SGX_IOC_ENCLAVE_CREATE \ + _IOW(SGX_MAGIC, 0x00, struct sgx_enclave_create) +#define SGX_IOC_ENCLAVE_ADD_PAGES \ + _IOWR(SGX_MAGIC, 0x01, struct sgx_enclave_add_pages) +#define SGX_IOC_ENCLAVE_INIT \ + _IOW(SGX_MAGIC, 0x02, struct sgx_enclave_init) + +/** + * struct sgx_enclave_create - parameter structure for the + * %SGX_IOC_ENCLAVE_CREATE ioctl + * @src: address for the SECS page data + */ +struct sgx_enclave_create { + __u64 src; +}; + +/** + * struct sgx_enclave_add_pages - parameter structure for the + * %SGX_IOC_ENCLAVE_ADD_PAGE ioctl + * @src: start address for the page data + * @offset: starting page offset + * @length: length of the data (multiple of the page size) + * @secinfo: address for the SECINFO data + * @flags: page control flags + * @count: number of bytes added (multiple of the page size) + */ +struct sgx_enclave_add_pages { + __u64 src; + __u64 offset; + __u64 length; + __u64 secinfo; + __u64 flags; + __u64 count; +}; + +/** + * struct sgx_enclave_init - parameter structure for the + * %SGX_IOC_ENCLAVE_INIT ioctl + * @sigstruct: address for the SIGSTRUCT data + */ +struct sgx_enclave_init { + __u64 sigstruct; +}; + +#endif /* _UAPI_ASM_X86_SGX_H */ diff --git a/arch/x86/kernel/cpu/sgx/Makefile b/arch/x86/kernel/cpu/sgx/Makefile index 2dec75916a5e..f8d32da3a67a 100644 --- a/arch/x86/kernel/cpu/sgx/Makefile +++ b/arch/x86/kernel/cpu/sgx/Makefile @@ -1,3 +1,6 @@ obj-y += \ + driver.o \ + encl.o \ + ioctl.o \ main.o \ reclaim.o diff --git a/arch/x86/kernel/cpu/sgx/driver.c b/arch/x86/kernel/cpu/sgx/driver.c new file mode 100644 index 000000000000..b4aa7b9f8376 --- /dev/null +++ b/arch/x86/kernel/cpu/sgx/driver.c @@ -0,0 +1,194 @@ +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) +// Copyright(c) 2016-18 Intel Corporation. + +#include +#include +#include +#include +#include +#include +#include "driver.h" +#include "encl.h" + +MODULE_DESCRIPTION("Intel SGX Enclave Driver"); +MODULE_AUTHOR("Jarkko Sakkinen "); +MODULE_LICENSE("Dual BSD/GPL"); + +u64 sgx_encl_size_max_32; +u64 sgx_encl_size_max_64; +u32 sgx_misc_reserved_mask; +u64 sgx_attributes_reserved_mask; +u64 sgx_xfrm_reserved_mask = ~0x3; +u32 sgx_xsave_size_tbl[64]; + +static int sgx_open(struct inode *inode, struct file *file) +{ + struct sgx_encl *encl; + int ret; + + encl = kzalloc(sizeof(*encl), GFP_KERNEL); + if (!encl) + return -ENOMEM; + + atomic_set(&encl->flags, 0); + kref_init(&encl->refcount); + INIT_RADIX_TREE(&encl->page_tree, GFP_KERNEL); + mutex_init(&encl->lock); + INIT_LIST_HEAD(&encl->mm_list); + spin_lock_init(&encl->mm_lock); + + ret = init_srcu_struct(&encl->srcu); + if (ret) { + kfree(encl); + return ret; + } + + file->private_data = encl; + + return 0; +} + +static int sgx_release(struct inode *inode, struct file *file) +{ + struct sgx_encl *encl = file->private_data; + struct sgx_encl_mm *encl_mm; + + for ( ; ; ) { + spin_lock(&encl->mm_lock); + + if (list_empty(&encl->mm_list)) { + encl_mm = NULL; + } else { + encl_mm = list_first_entry(&encl->mm_list, + struct sgx_encl_mm, list); + list_del_rcu(&encl_mm->list); + } + + spin_unlock(&encl->mm_lock); + + /* The list is empty, ready to go. */ + if (!encl_mm) + break; + + synchronize_srcu(&encl->srcu); + mmu_notifier_unregister(&encl_mm->mmu_notifier, encl_mm->mm); + kfree(encl_mm); + }; + + mutex_lock(&encl->lock); + atomic_or(SGX_ENCL_DEAD, &encl->flags); + mutex_unlock(&encl->lock); + + kref_put(&encl->refcount, sgx_encl_release); + return 0; +} + +#ifdef CONFIG_COMPAT +static long sgx_compat_ioctl(struct file *filep, unsigned int cmd, + unsigned long arg) +{ + return sgx_ioctl(filep, cmd, arg); +} +#endif + +static int sgx_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct sgx_encl *encl = file->private_data; + int ret; + + ret = sgx_encl_may_map(encl, vma->vm_start, vma->vm_end, + vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)); + if (ret) + return ret; + + ret = sgx_encl_mm_add(encl, vma->vm_mm); + if (ret) + return ret; + + vma->vm_ops = &sgx_vm_ops; + vma->vm_flags |= VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP | VM_IO; + vma->vm_private_data = encl; + + return 0; +} + +static unsigned long sgx_get_unmapped_area(struct file *file, + unsigned long addr, + unsigned long len, + unsigned long pgoff, + unsigned long flags) +{ + if (flags & MAP_PRIVATE) + return -EINVAL; + + if (flags & MAP_FIXED) + return addr; + + return current->mm->get_unmapped_area(file, addr, len, pgoff, flags); +} + +static const struct file_operations sgx_encl_fops = { + .owner = THIS_MODULE, + .open = sgx_open, + .release = sgx_release, + .unlocked_ioctl = sgx_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = sgx_compat_ioctl, +#endif + .mmap = sgx_mmap, + .get_unmapped_area = sgx_get_unmapped_area, +}; + +const struct file_operations sgx_provision_fops = { + .owner = THIS_MODULE, +}; + +static struct miscdevice sgx_dev_enclave = { + .minor = MISC_DYNAMIC_MINOR, + .name = "enclave", + .nodename = "sgx/enclave", + .fops = &sgx_encl_fops, +}; + +int __init sgx_drv_init(void) +{ + unsigned int eax, ebx, ecx, edx; + u64 attr_mask, xfrm_mask; + int ret; + int i; + + if (!boot_cpu_has(X86_FEATURE_SGX_LC)) { + pr_info("The public key MSRs are not writable.\n"); + return -ENODEV; + } + + cpuid_count(SGX_CPUID, 0, &eax, &ebx, &ecx, &edx); + sgx_misc_reserved_mask = ~ebx | SGX_MISC_RESERVED_MASK; + sgx_encl_size_max_64 = 1ULL << ((edx >> 8) & 0xFF); + sgx_encl_size_max_32 = 1ULL << (edx & 0xFF); + + cpuid_count(SGX_CPUID, 1, &eax, &ebx, &ecx, &edx); + + attr_mask = (((u64)ebx) << 32) + (u64)eax; + sgx_attributes_reserved_mask = ~attr_mask | SGX_ATTR_RESERVED_MASK; + + if (boot_cpu_has(X86_FEATURE_OSXSAVE)) { + xfrm_mask = (((u64)edx) << 32) + (u64)ecx; + + for (i = 2; i < 64; i++) { + cpuid_count(0x0D, i, &eax, &ebx, &ecx, &edx); + if ((1 << i) & xfrm_mask) + sgx_xsave_size_tbl[i] = eax + ebx; + } + + sgx_xfrm_reserved_mask = ~xfrm_mask; + } + + ret = misc_register(&sgx_dev_enclave); + if (ret) { + pr_err("Creating /dev/sgx/enclave failed with %d.\n", ret); + return ret; + } + + return 0; +} diff --git a/arch/x86/kernel/cpu/sgx/driver.h b/arch/x86/kernel/cpu/sgx/driver.h new file mode 100644 index 000000000000..e4063923115b --- /dev/null +++ b/arch/x86/kernel/cpu/sgx/driver.h @@ -0,0 +1,30 @@ +/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */ +#ifndef __ARCH_SGX_DRIVER_H__ +#define __ARCH_SGX_DRIVER_H__ + +#include +#include +#include +#include +#include +#include +#include +#include +#include "sgx.h" + +#define SGX_EINIT_SPIN_COUNT 20 +#define SGX_EINIT_SLEEP_COUNT 50 +#define SGX_EINIT_SLEEP_TIME 20 + +extern u64 sgx_encl_size_max_32; +extern u64 sgx_encl_size_max_64; +extern u32 sgx_misc_reserved_mask; +extern u64 sgx_attributes_reserved_mask; +extern u64 sgx_xfrm_reserved_mask; +extern u32 sgx_xsave_size_tbl[64]; + +long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg); + +int sgx_drv_init(void); + +#endif /* __ARCH_X86_SGX_DRIVER_H__ */ diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c new file mode 100644 index 000000000000..17e44bf8fa56 --- /dev/null +++ b/arch/x86/kernel/cpu/sgx/encl.c @@ -0,0 +1,332 @@ +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) +// Copyright(c) 2016-18 Intel Corporation. + +#include +#include +#include +#include +#include +#include +#include "arch.h" +#include "encl.h" +#include "sgx.h" + +static struct sgx_encl_page *sgx_encl_load_page(struct sgx_encl *encl, + unsigned long addr) +{ + struct sgx_encl_page *entry; + unsigned int flags; + + /* If process was forked, VMA is still there but vm_private_data is set + * to NULL. + */ + if (!encl) + return ERR_PTR(-EFAULT); + + flags = atomic_read(&encl->flags); + + if ((flags & SGX_ENCL_DEAD) || !(flags & SGX_ENCL_INITIALIZED)) + return ERR_PTR(-EFAULT); + + entry = radix_tree_lookup(&encl->page_tree, addr >> PAGE_SHIFT); + if (!entry) + return ERR_PTR(-EFAULT); + + /* Page is already resident in the EPC. */ + if (entry->epc_page) + return entry; + + return ERR_PTR(-EFAULT); +} + +static void sgx_mmu_notifier_release(struct mmu_notifier *mn, + struct mm_struct *mm) +{ + struct sgx_encl_mm *encl_mm = + container_of(mn, struct sgx_encl_mm, mmu_notifier); + struct sgx_encl_mm *tmp = NULL; + + /* + * The enclave itself can remove encl_mm. Note, objects can't be moved + * off an RCU protected list, but deletion is ok. + */ + spin_lock(&encl_mm->encl->mm_lock); + list_for_each_entry(tmp, &encl_mm->encl->mm_list, list) { + if (tmp == encl_mm) { + list_del_rcu(&encl_mm->list); + break; + } + } + spin_unlock(&encl_mm->encl->mm_lock); + + if (tmp == encl_mm) { + synchronize_srcu(&encl_mm->encl->srcu); + mmu_notifier_put(mn); + } +} + +static void sgx_mmu_notifier_free(struct mmu_notifier *mn) +{ + struct sgx_encl_mm *encl_mm = + container_of(mn, struct sgx_encl_mm, mmu_notifier); + + kfree(encl_mm); +} + +static const struct mmu_notifier_ops sgx_mmu_notifier_ops = { + .release = sgx_mmu_notifier_release, + .free_notifier = sgx_mmu_notifier_free, +}; + +static struct sgx_encl_mm *sgx_encl_find_mm(struct sgx_encl *encl, + struct mm_struct *mm) +{ + struct sgx_encl_mm *encl_mm = NULL; + struct sgx_encl_mm *tmp; + int idx; + + idx = srcu_read_lock(&encl->srcu); + + list_for_each_entry_rcu(tmp, &encl->mm_list, list) { + if (tmp->mm == mm) { + encl_mm = tmp; + break; + } + } + + srcu_read_unlock(&encl->srcu, idx); + + return encl_mm; +} + +int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm) +{ + struct sgx_encl_mm *encl_mm; + int ret; + + /* mm_list can be accessed only by a single thread at a time. */ + lockdep_assert_held_write(&mm->mmap_sem); + + if (atomic_read(&encl->flags) & SGX_ENCL_DEAD) + return -EINVAL; + + /* + * mm_structs are kept on mm_list until the mm or the enclave dies, + * i.e. once an mm is off the list, it's gone for good, therefore it's + * impossible to get a false positive on @mm due to a stale mm_list. + */ + if (sgx_encl_find_mm(encl, mm)) + return 0; + + encl_mm = kzalloc(sizeof(*encl_mm), GFP_KERNEL); + if (!encl_mm) + return -ENOMEM; + + encl_mm->encl = encl; + encl_mm->mm = mm; + encl_mm->mmu_notifier.ops = &sgx_mmu_notifier_ops; + + ret = __mmu_notifier_register(&encl_mm->mmu_notifier, mm); + if (ret) { + kfree(encl_mm); + return ret; + } + + spin_lock(&encl->mm_lock); + list_add_rcu(&encl_mm->list, &encl->mm_list); + spin_unlock(&encl->mm_lock); + + return 0; +} + +static void sgx_vma_open(struct vm_area_struct *vma) +{ + struct sgx_encl *encl = vma->vm_private_data; + + if (!encl) + return; + + if (sgx_encl_mm_add(encl, vma->vm_mm)) + vma->vm_private_data = NULL; +} + +static unsigned int sgx_vma_fault(struct vm_fault *vmf) +{ + unsigned long addr = (unsigned long)vmf->address; + struct vm_area_struct *vma = vmf->vma; + struct sgx_encl *encl = vma->vm_private_data; + struct sgx_encl_page *entry; + int ret = VM_FAULT_NOPAGE; + unsigned long pfn; + + if (!encl) + return VM_FAULT_SIGBUS; + + mutex_lock(&encl->lock); + + entry = sgx_encl_load_page(encl, addr); + if (IS_ERR(entry)) { + if (unlikely(PTR_ERR(entry) != -EBUSY)) + ret = VM_FAULT_SIGBUS; + + goto out; + } + + if (!follow_pfn(vma, addr, &pfn)) + goto out; + + ret = vmf_insert_pfn(vma, addr, PFN_DOWN(entry->epc_page->desc)); + if (ret != VM_FAULT_NOPAGE) { + ret = VM_FAULT_SIGBUS; + goto out; + } + +out: + mutex_unlock(&encl->lock); + return ret; +} + +/** + * sgx_encl_may_map() - Check if a requested VMA mapping is allowed + * @encl: an enclave + * @start: lower bound of the address range, inclusive + * @end: upper bound of the address range, exclusive + * @vm_prot_bits: requested protections of the address range + * + * Iterate through the enclave pages contained within [@start, @end) to verify + * the permissions requested by @vm_prot_bits do not exceed that of any enclave + * page to be mapped. + * + * Return: + * 0 on success, + * -EACCES if VMA permissions exceed enclave page permissions + */ +int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start, + unsigned long end, unsigned long vm_prot_bits) +{ + unsigned long idx, idx_start, idx_end; + struct sgx_encl_page *page; + + /* + * Disallow RIE tasks as their VMA permissions might conflict with the + * enclave page permissions. + */ + if (!!(current->personality & READ_IMPLIES_EXEC)) + return -EACCES; + + idx_start = PFN_DOWN(start); + idx_end = PFN_DOWN(end - 1); + + for (idx = idx_start; idx <= idx_end; ++idx) { + mutex_lock(&encl->lock); + page = radix_tree_lookup(&encl->page_tree, idx); + mutex_unlock(&encl->lock); + + if (!page || (~page->vm_max_prot_bits & vm_prot_bits)) + return -EACCES; + } + + return 0; +} + +static int sgx_vma_mprotect(struct vm_area_struct *vma, unsigned long start, + unsigned long end, unsigned long prot) +{ + return sgx_encl_may_map(vma->vm_private_data, start, end, + calc_vm_prot_bits(prot, 0)); +} + +const struct vm_operations_struct sgx_vm_ops = { + .open = sgx_vma_open, + .fault = sgx_vma_fault, + .may_mprotect = sgx_vma_mprotect, +}; + +/** + * sgx_encl_find - find an enclave + * @mm: mm struct of the current process + * @addr: address in the ELRANGE + * @vma: the resulting VMA + * + * Find an enclave identified by the given address. Give back a VMA that is + * part of the enclave and located in that address. The VMA is given back if it + * is a proper enclave VMA even if an &sgx_encl instance does not exist yet + * (enclave creation has not been performed). + * + * Return: + * 0 on success, + * -EINVAL if an enclave was not found, + * -ENOENT if the enclave has not been created yet + */ +int sgx_encl_find(struct mm_struct *mm, unsigned long addr, + struct vm_area_struct **vma) +{ + struct vm_area_struct *result; + struct sgx_encl *encl; + + result = find_vma(mm, addr); + if (!result || result->vm_ops != &sgx_vm_ops || addr < result->vm_start) + return -EINVAL; + + encl = result->vm_private_data; + *vma = result; + + return encl ? 0 : -ENOENT; +} + +/** + * sgx_encl_destroy() - destroy enclave resources + * @encl: an &sgx_encl instance + */ +void sgx_encl_destroy(struct sgx_encl *encl) +{ + struct sgx_encl_page *entry; + struct radix_tree_iter iter; + void **slot; + + atomic_or(SGX_ENCL_DEAD, &encl->flags); + + radix_tree_for_each_slot(slot, &encl->page_tree, &iter, 0) { + entry = *slot; + + if (entry->epc_page) { + sgx_free_page(entry->epc_page); + encl->secs_child_cnt--; + entry->epc_page = NULL; + } + + radix_tree_delete(&entry->encl->page_tree, + PFN_DOWN(entry->desc)); + kfree(entry); + } + + if (!encl->secs_child_cnt && encl->secs.epc_page) { + sgx_free_page(encl->secs.epc_page); + encl->secs.epc_page = NULL; + } +} + +/** + * sgx_encl_release - Destroy an enclave instance + * @kref: address of a kref inside &sgx_encl + * + * Used together with kref_put(). Frees all the resources associated with the + * enclave and the instance itself. + */ +void sgx_encl_release(struct kref *ref) +{ + struct sgx_encl *encl = container_of(ref, struct sgx_encl, refcount); + + sgx_encl_destroy(encl); + + if (encl->backing) + fput(encl->backing); + + WARN_ON_ONCE(!list_empty(&encl->mm_list)); + + /* Detect EPC page leak's. */ + WARN_ON_ONCE(encl->secs_child_cnt); + WARN_ON_ONCE(encl->secs.epc_page); + + kfree(encl); +} diff --git a/arch/x86/kernel/cpu/sgx/encl.h b/arch/x86/kernel/cpu/sgx/encl.h new file mode 100644 index 000000000000..1d1bc5d590ee --- /dev/null +++ b/arch/x86/kernel/cpu/sgx/encl.h @@ -0,0 +1,87 @@ +/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */ +/** + * Copyright(c) 2016-19 Intel Corporation. + */ +#ifndef _X86_ENCL_H +#define _X86_ENCL_H + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "sgx.h" + +/** + * enum sgx_encl_page_desc - defines bits for an enclave page's descriptor + * %SGX_ENCL_PAGE_ADDR_MASK: Holds the virtual address of the page. + * + * The page address for SECS is zero and is used by the subsystem to recognize + * the SECS page. + */ +enum sgx_encl_page_desc { + /* Bits 11:3 are available when the page is not swapped. */ + SGX_ENCL_PAGE_ADDR_MASK = PAGE_MASK, +}; + +#define SGX_ENCL_PAGE_ADDR(page) \ + ((page)->desc & SGX_ENCL_PAGE_ADDR_MASK) + +struct sgx_encl_page { + unsigned long desc; + unsigned long vm_max_prot_bits; + struct sgx_epc_page *epc_page; + struct sgx_encl *encl; +}; + +enum sgx_encl_flags { + SGX_ENCL_CREATED = BIT(0), + SGX_ENCL_INITIALIZED = BIT(1), + SGX_ENCL_DEBUG = BIT(2), + SGX_ENCL_DEAD = BIT(3), + SGX_ENCL_IOCTL = BIT(4), +}; + +struct sgx_encl_mm { + struct sgx_encl *encl; + struct mm_struct *mm; + struct list_head list; + struct mmu_notifier mmu_notifier; +}; + +struct sgx_encl { + atomic_t flags; + u64 secs_attributes; + u64 allowed_attributes; + unsigned int page_cnt; + unsigned int secs_child_cnt; + struct mutex lock; + struct list_head mm_list; + spinlock_t mm_lock; + struct file *backing; + struct kref refcount; + struct srcu_struct srcu; + unsigned long base; + unsigned long size; + unsigned long ssaframesize; + struct radix_tree_root page_tree; + struct sgx_encl_page secs; + cpumask_t cpumask; +}; + +extern const struct vm_operations_struct sgx_vm_ops; + +int sgx_encl_find(struct mm_struct *mm, unsigned long addr, + struct vm_area_struct **vma); +void sgx_encl_destroy(struct sgx_encl *encl); +void sgx_encl_release(struct kref *ref); +int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm); +int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start, + unsigned long end, unsigned long vm_prot_bits); + +#endif /* _X86_ENCL_H */ diff --git a/arch/x86/kernel/cpu/sgx/encls.h b/arch/x86/kernel/cpu/sgx/encls.h index 376cdedb9a43..f716b4328614 100644 --- a/arch/x86/kernel/cpu/sgx/encls.h +++ b/arch/x86/kernel/cpu/sgx/encls.h @@ -186,10 +186,9 @@ static inline int __eadd(struct sgx_pageinfo *pginfo, void *addr) return __encls_2(EADD, pginfo, addr); } -static inline int __einit(void *sigstruct, struct sgx_einittoken *einittoken, - void *secs) +static inline int __einit(void *sigstruct, void *token, void *secs) { - return __encls_ret_3(EINIT, sigstruct, secs, einittoken); + return __encls_ret_3(EINIT, sigstruct, secs, token); } static inline int __eremove(void *addr) diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c new file mode 100644 index 000000000000..26d0425d7252 --- /dev/null +++ b/arch/x86/kernel/cpu/sgx/ioctl.c @@ -0,0 +1,687 @@ +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) +// Copyright(c) 2016-19 Intel Corporation. + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "driver.h" +#include "encl.h" +#include "encls.h" + +/* A per-cpu cache for the last known values of IA32_SGXLEPUBKEYHASHx MSRs. */ +static DEFINE_PER_CPU(u64 [4], sgx_lepubkeyhash_cache); + +static u32 sgx_calc_ssaframesize(u32 miscselect, u64 xfrm) +{ + u32 size_max = PAGE_SIZE; + u32 size; + int i; + + for (i = 2; i < 64; i++) { + if (!((1 << i) & xfrm)) + continue; + + size = SGX_SSA_GPRS_SIZE + sgx_xsave_size_tbl[i]; + if (miscselect & SGX_MISC_EXINFO) + size += SGX_SSA_MISC_EXINFO_SIZE; + + if (size > size_max) + size_max = size; + } + + return PFN_UP(size_max); +} + +static int sgx_validate_secs(const struct sgx_secs *secs, + unsigned long ssaframesize) +{ + if (secs->size < (2 * PAGE_SIZE) || !is_power_of_2(secs->size)) + return -EINVAL; + + if (secs->base & (secs->size - 1)) + return -EINVAL; + + if (secs->miscselect & sgx_misc_reserved_mask || + secs->attributes & sgx_attributes_reserved_mask || + secs->xfrm & sgx_xfrm_reserved_mask) + return -EINVAL; + + if (secs->attributes & SGX_ATTR_MODE64BIT) { + if (secs->size > sgx_encl_size_max_64) + return -EINVAL; + } else if (secs->size > sgx_encl_size_max_32) + return -EINVAL; + + if (!(secs->xfrm & XFEATURE_MASK_FP) || + !(secs->xfrm & XFEATURE_MASK_SSE) || + (((secs->xfrm >> XFEATURE_BNDREGS) & 1) != + ((secs->xfrm >> XFEATURE_BNDCSR) & 1))) + return -EINVAL; + + if (!secs->ssa_frame_size || ssaframesize > secs->ssa_frame_size) + return -EINVAL; + + if (memchr_inv(secs->reserved1, 0, sizeof(secs->reserved1)) || + memchr_inv(secs->reserved2, 0, sizeof(secs->reserved2)) || + memchr_inv(secs->reserved3, 0, sizeof(secs->reserved3)) || + memchr_inv(secs->reserved4, 0, sizeof(secs->reserved4))) + return -EINVAL; + + return 0; +} + +static struct sgx_encl_page *sgx_encl_page_alloc(struct sgx_encl *encl, + unsigned long offset, + u64 secinfo_flags) +{ + struct sgx_encl_page *encl_page; + unsigned long prot; + + encl_page = kzalloc(sizeof(*encl_page), GFP_KERNEL); + if (!encl_page) + return ERR_PTR(-ENOMEM); + + encl_page->desc = encl->base + offset; + encl_page->encl = encl; + + prot = _calc_vm_trans(secinfo_flags, SGX_SECINFO_R, PROT_READ) | + _calc_vm_trans(secinfo_flags, SGX_SECINFO_W, PROT_WRITE) | + _calc_vm_trans(secinfo_flags, SGX_SECINFO_X, PROT_EXEC); + + /* + * TCS pages must always RW set for CPU access while the SECINFO + * permissions are *always* zero - the CPU ignores the user provided + * values and silently overwrites them with zero permissions. + */ + if ((secinfo_flags & SGX_SECINFO_PAGE_TYPE_MASK) == SGX_SECINFO_TCS) + prot |= PROT_READ | PROT_WRITE; + + /* Calculate maximum of the VM flags for the page. */ + encl_page->vm_max_prot_bits = calc_vm_prot_bits(prot, 0); + + return encl_page; +} + +static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs) +{ + unsigned long encl_size = secs->size + PAGE_SIZE; + struct sgx_epc_page *secs_epc; + unsigned long ssaframesize; + struct sgx_pageinfo pginfo; + struct sgx_secinfo secinfo; + struct file *backing; + long ret; + + if (atomic_read(&encl->flags) & SGX_ENCL_CREATED) + return -EINVAL; + + ssaframesize = sgx_calc_ssaframesize(secs->miscselect, secs->xfrm); + if (sgx_validate_secs(secs, ssaframesize)) { + pr_debug("invalid SECS\n"); + return -EINVAL; + } + + backing = shmem_file_setup("SGX backing", encl_size + (encl_size >> 5), + VM_NORESERVE); + if (IS_ERR(backing)) + return PTR_ERR(backing); + + encl->backing = backing; + + secs_epc = sgx_try_alloc_page(); + if (IS_ERR(secs_epc)) { + ret = PTR_ERR(secs_epc); + goto err_out_backing; + } + + encl->secs.epc_page = secs_epc; + + pginfo.addr = 0; + pginfo.contents = (unsigned long)secs; + pginfo.metadata = (unsigned long)&secinfo; + pginfo.secs = 0; + memset(&secinfo, 0, sizeof(secinfo)); + + ret = __ecreate((void *)&pginfo, sgx_epc_addr(secs_epc)); + if (ret) { + pr_debug("ECREATE returned %ld\n", ret); + goto err_out; + } + + if (secs->attributes & SGX_ATTR_DEBUG) + atomic_or(SGX_ENCL_DEBUG, &encl->flags); + + encl->secs.encl = encl; + encl->secs_attributes = secs->attributes; + encl->allowed_attributes |= SGX_ATTR_ALLOWED_MASK; + encl->base = secs->base; + encl->size = secs->size; + encl->ssaframesize = secs->ssa_frame_size; + + /* + * Set SGX_ENCL_CREATED only after the enclave is fully prepped. This + * allows setting and checking enclave creation without having to take + * encl->lock. + */ + atomic_or(SGX_ENCL_CREATED, &encl->flags); + + return 0; + +err_out: + sgx_free_page(encl->secs.epc_page); + encl->secs.epc_page = NULL; + +err_out_backing: + fput(encl->backing); + encl->backing = NULL; + + return ret; +} + +/** + * sgx_ioc_enclave_create - handler for %SGX_IOC_ENCLAVE_CREATE + * @filep: open file to /dev/sgx + * @arg: userspace pointer to a struct sgx_enclave_create instance + * + * Allocate kernel data structures for a new enclave and execute ECREATE after + * verifying the correctness of the provided SECS. + * + * Note, enforcement of restricted and disallowed attributes is deferred until + * sgx_ioc_enclave_init(), only the architectural correctness of the SECS is + * checked by sgx_ioc_enclave_create(). + * + * Return: + * 0 on success, + * -errno otherwise + */ +static long sgx_ioc_enclave_create(struct sgx_encl *encl, void __user *arg) +{ + struct sgx_enclave_create ecreate; + struct page *secs_page; + struct sgx_secs *secs; + int ret; + + if (copy_from_user(&ecreate, arg, sizeof(ecreate))) + return -EFAULT; + + secs_page = alloc_page(GFP_KERNEL); + if (!secs_page) + return -ENOMEM; + + secs = kmap(secs_page); + if (copy_from_user(secs, (void __user *)ecreate.src, sizeof(*secs))) { + ret = -EFAULT; + goto out; + } + + ret = sgx_encl_create(encl, secs); + +out: + kunmap(secs_page); + __free_page(secs_page); + return ret; +} + +static int sgx_validate_secinfo(struct sgx_secinfo *secinfo) +{ + u64 perm = secinfo->flags & SGX_SECINFO_PERMISSION_MASK; + u64 pt = secinfo->flags & SGX_SECINFO_PAGE_TYPE_MASK; + + if (pt != SGX_SECINFO_REG && pt != SGX_SECINFO_TCS) + return -EINVAL; + + if ((perm & SGX_SECINFO_W) && !(perm & SGX_SECINFO_R)) + return -EINVAL; + + /* + * CPU will silently overwrite the permissions as zero, which means + * that we need to validate it ourselves. + */ + if (pt == SGX_SECINFO_TCS && perm) + return -EINVAL; + + if (secinfo->flags & SGX_SECINFO_RESERVED_MASK) + return -EINVAL; + + if (memchr_inv(secinfo->reserved, 0, sizeof(secinfo->reserved))) + return -EINVAL; + + return 0; +} + +static int __sgx_encl_add_page(struct sgx_encl *encl, + struct sgx_encl_page *encl_page, + struct sgx_epc_page *epc_page, + struct sgx_secinfo *secinfo, unsigned long src) +{ + struct sgx_pageinfo pginfo; + struct vm_area_struct *vma; + struct page *src_page; + int ret; + + /* Query vma's VM_MAYEXEC as an indirect path_noexec() check. */ + if (encl_page->vm_max_prot_bits & VM_EXEC) { + vma = find_vma(current->mm, src); + if (!vma) + return -EFAULT; + + if (!(vma->vm_flags & VM_MAYEXEC)) + return -EACCES; + } + + ret = get_user_pages(src, 1, 0, &src_page, NULL); + if (ret < 1) + return ret; + + pginfo.secs = (unsigned long)sgx_epc_addr(encl->secs.epc_page); + pginfo.addr = SGX_ENCL_PAGE_ADDR(encl_page); + pginfo.metadata = (unsigned long)secinfo; + pginfo.contents = (unsigned long)kmap_atomic(src_page); + + ret = __eadd(&pginfo, sgx_epc_addr(epc_page)); + + kunmap_atomic((void *)pginfo.contents); + put_page(src_page); + + return ret ? -EIO : 0; +} + +static int __sgx_encl_extend(struct sgx_encl *encl, + struct sgx_epc_page *epc_page) +{ + int ret; + int i; + + for (i = 0; i < 16; i++) { + ret = __eextend(sgx_epc_addr(encl->secs.epc_page), + sgx_epc_addr(epc_page) + (i * 0x100)); + if (ret) { + if (encls_failed(ret)) + ENCLS_WARN(ret, "EEXTEND"); + return -EIO; + } + } + + return 0; +} + +static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long src, + unsigned long offset, unsigned long length, + struct sgx_secinfo *secinfo, unsigned long flags) +{ + struct sgx_encl_page *encl_page; + struct sgx_epc_page *epc_page; + int ret; + + encl_page = sgx_encl_page_alloc(encl, offset, secinfo->flags); + if (IS_ERR(encl_page)) + return PTR_ERR(encl_page); + + epc_page = sgx_try_alloc_page(); + if (IS_ERR(epc_page)) { + kfree(encl_page); + return PTR_ERR(epc_page); + } + + if (atomic_read(&encl->flags) & + (SGX_ENCL_INITIALIZED | SGX_ENCL_DEAD)) { + ret = -EFAULT; + goto err_out_free; + } + + down_read(¤t->mm->mmap_sem); + mutex_lock(&encl->lock); + + /* + * Insert prior to EADD in case of OOM. EADD modifies MRENCLAVE, i.e. + * can't be gracefully unwound, while failure on EADD/EXTEND is limited + * to userspace errors (or kernel/hardware bugs). + */ + ret = radix_tree_insert(&encl->page_tree, PFN_DOWN(encl_page->desc), + encl_page); + if (ret) + goto err_out_unlock; + + ret = __sgx_encl_add_page(encl, encl_page, epc_page, secinfo, + src); + if (ret) + goto err_out; + + /* + * Complete the "add" before doing the "extend" so that the "add" + * isn't in a half-baked state in the extremely unlikely scenario the + * the enclave will be destroyed in response to EEXTEND failure. + */ + encl_page->encl = encl; + encl_page->epc_page = epc_page; + encl->secs_child_cnt++; + + if (flags & SGX_PAGE_MEASURE) { + ret = __sgx_encl_extend(encl, epc_page); + if (ret) + goto err_out; + } + + mutex_unlock(&encl->lock); + up_read(¤t->mm->mmap_sem); + return ret; + +err_out: + radix_tree_delete(&encl_page->encl->page_tree, + PFN_DOWN(encl_page->desc)); + +err_out_unlock: + mutex_unlock(&encl->lock); + up_read(¤t->mm->mmap_sem); + +err_out_free: + sgx_free_page(epc_page); + kfree(encl_page); + + /* + * Destroy enclave on ENCLS failure as this means that EPC has been + * invalidated. + */ + if (ret == -EIO) + sgx_encl_destroy(encl); + + return ret; +} + +/** + * sgx_ioc_enclave_add_pages() - The handler for %SGX_IOC_ENCLAVE_ADD_PAGES + * @encl: pointer to an enclave instance (via ioctl() file pointer) + * @arg: a user pointer to a struct sgx_enclave_add_pages instance + * + * Add one or more pages to an uninitialized enclave, and optionally extend the + * measurement with the contents of the page. The address range of pages must + * be contiguous. The SECINFO and measurement mask are applied to all pages. + * + * A SECINFO for a TCS is required to always contain zero permissions because + * CPU silently zeros them. Allowing anything else would cause a mismatch in + * the measurement. + * + * mmap()'s protection bits are capped by the page permissions. For each page + * address, the maximum protection bits are computed with the following + * heuristics: + * + * 1. A regular page: PROT_R, PROT_W and PROT_X match the SECINFO permissions. + * 2. A TCS page: PROT_R | PROT_W. + * + * mmap() is not allowed to surpass the minimum of the maximum protection bits + * within the given address range. + * + * If ENCLS opcode fails, that effectively means that EPC has been invalidated. + * When this happens the enclave is destroyed and -EIO is returned to the + * caller. + * + * Return: + * 0 on success, + * -EACCES if an executable source page is located in a noexec partition, + * -EIO if either ENCLS[EADD] or ENCLS[EEXTEND] fails + * -errno otherwise + */ +static long sgx_ioc_enclave_add_pages(struct sgx_encl *encl, void __user *arg) +{ + struct sgx_enclave_add_pages addp; + struct sgx_secinfo secinfo; + unsigned long c; + int ret; + + if (!(atomic_read(&encl->flags) & SGX_ENCL_CREATED)) + return -EINVAL; + + if (copy_from_user(&addp, arg, sizeof(addp))) + return -EFAULT; + + if (!IS_ALIGNED(addp.offset, PAGE_SIZE) || + !IS_ALIGNED(addp.src, PAGE_SIZE)) + return -EINVAL; + + if (!(access_ok(addp.src, PAGE_SIZE))) + return -EFAULT; + + if (addp.length & (PAGE_SIZE - 1)) + return -EINVAL; + + if (addp.offset + addp.length - PAGE_SIZE >= encl->size) + return -EINVAL; + + if (copy_from_user(&secinfo, (void __user *)addp.secinfo, + sizeof(secinfo))) + return -EFAULT; + + if (sgx_validate_secinfo(&secinfo)) + return -EINVAL; + + for (c = 0 ; c < addp.length; c += PAGE_SIZE) { + if (signal_pending(current)) { + ret = -EINTR; + break; + } + + if (need_resched()) + cond_resched(); + + ret = sgx_encl_add_page(encl, addp.src + c, addp.offset + c, + addp.length - c, &secinfo, addp.flags); + if (ret) + break; + } + + addp.count = c; + + if (copy_to_user(arg, &addp, sizeof(addp))) + return -EFAULT; + + return ret; +} + +static int __sgx_get_key_hash(struct crypto_shash *tfm, const void *modulus, + void *hash) +{ + SHASH_DESC_ON_STACK(shash, tfm); + + shash->tfm = tfm; + + return crypto_shash_digest(shash, modulus, SGX_MODULUS_SIZE, hash); +} + +static int sgx_get_key_hash(const void *modulus, void *hash) +{ + struct crypto_shash *tfm; + int ret; + + tfm = crypto_alloc_shash("sha256", 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + ret = __sgx_get_key_hash(tfm, modulus, hash); + + crypto_free_shash(tfm); + return ret; +} + +static void sgx_update_lepubkeyhash_msrs(u64 *lepubkeyhash, bool enforce) +{ + u64 *cache; + int i; + + cache = per_cpu(sgx_lepubkeyhash_cache, smp_processor_id()); + for (i = 0; i < 4; i++) { + if (enforce || (lepubkeyhash[i] != cache[i])) { + wrmsrl(MSR_IA32_SGXLEPUBKEYHASH0 + i, lepubkeyhash[i]); + cache[i] = lepubkeyhash[i]; + } + } +} + +static int sgx_einit(struct sgx_sigstruct *sigstruct, void *token, + struct sgx_epc_page *secs, u64 *lepubkeyhash) +{ + int ret; + + preempt_disable(); + sgx_update_lepubkeyhash_msrs(lepubkeyhash, false); + ret = __einit(sigstruct, token, sgx_epc_addr(secs)); + if (ret == SGX_INVALID_EINITTOKEN) { + sgx_update_lepubkeyhash_msrs(lepubkeyhash, true); + ret = __einit(sigstruct, token, sgx_epc_addr(secs)); + } + preempt_enable(); + return ret; +} + +static int sgx_encl_init(struct sgx_encl *encl, struct sgx_sigstruct *sigstruct, + void *token) +{ + u64 mrsigner[4]; + int ret; + int i; + int j; + + /* Check that the required attributes have been authorized. */ + if (encl->secs_attributes & ~encl->allowed_attributes) + return -EACCES; + + ret = sgx_get_key_hash(sigstruct->modulus, mrsigner); + if (ret) + return ret; + + mutex_lock(&encl->lock); + + if (atomic_read(&encl->flags) & SGX_ENCL_INITIALIZED) { + ret = -EFAULT; + goto err_out; + } + + for (i = 0; i < SGX_EINIT_SLEEP_COUNT; i++) { + for (j = 0; j < SGX_EINIT_SPIN_COUNT; j++) { + ret = sgx_einit(sigstruct, token, encl->secs.epc_page, + mrsigner); + if (ret == SGX_UNMASKED_EVENT) + continue; + else + break; + } + + if (ret != SGX_UNMASKED_EVENT) + break; + + msleep_interruptible(SGX_EINIT_SLEEP_TIME); + + if (signal_pending(current)) { + ret = -ERESTARTSYS; + goto err_out; + } + } + + if (ret & ENCLS_FAULT_FLAG) { + if (encls_failed(ret)) + ENCLS_WARN(ret, "EINIT"); + + sgx_encl_destroy(encl); + ret = -EFAULT; + } else if (ret) { + pr_debug("EINIT returned %d\n", ret); + ret = -EPERM; + } else { + atomic_or(SGX_ENCL_INITIALIZED, &encl->flags); + } + +err_out: + mutex_unlock(&encl->lock); + return ret; +} + +/** + * sgx_ioc_enclave_init - handler for %SGX_IOC_ENCLAVE_INIT + * + * @filep: open file to /dev/sgx + * @arg: userspace pointer to a struct sgx_enclave_init instance + * + * Flush any outstanding enqueued EADD operations and perform EINIT. The + * Launch Enclave Public Key Hash MSRs are rewritten as necessary to match + * the enclave's MRSIGNER, which is caculated from the provided sigstruct. + * + * Return: + * 0 on success, + * SGX error code on EINIT failure, + * -errno otherwise + */ +static long sgx_ioc_enclave_init(struct sgx_encl *encl, void __user *arg) +{ + struct sgx_sigstruct *sigstruct; + struct sgx_enclave_init einit; + struct page *initp_page; + void *token; + int ret; + + if (!(atomic_read(&encl->flags) & SGX_ENCL_CREATED)) + return -EINVAL; + + if (copy_from_user(&einit, arg, sizeof(einit))) + return -EFAULT; + + initp_page = alloc_page(GFP_KERNEL); + if (!initp_page) + return -ENOMEM; + + sigstruct = kmap(initp_page); + token = (void *)((unsigned long)sigstruct + PAGE_SIZE / 2); + memset(token, 0, SGX_LAUNCH_TOKEN_SIZE); + + if (copy_from_user(sigstruct, (void __user *)einit.sigstruct, + sizeof(*sigstruct))) { + ret = -EFAULT; + goto out; + } + + ret = sgx_encl_init(encl, sigstruct, token); + +out: + kunmap(initp_page); + __free_page(initp_page); + return ret; +} + + +long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) +{ + struct sgx_encl *encl = filep->private_data; + int ret, encl_flags; + + encl_flags = atomic_fetch_or(SGX_ENCL_IOCTL, &encl->flags); + if (encl_flags & SGX_ENCL_IOCTL) + return -EBUSY; + + if (encl_flags & SGX_ENCL_DEAD) + return -EFAULT; + + switch (cmd) { + case SGX_IOC_ENCLAVE_CREATE: + ret = sgx_ioc_enclave_create(encl, (void __user *)arg); + break; + case SGX_IOC_ENCLAVE_ADD_PAGES: + ret = sgx_ioc_enclave_add_pages(encl, (void __user *)arg); + break; + case SGX_IOC_ENCLAVE_INIT: + ret = sgx_ioc_enclave_init(encl, (void __user *)arg); + break; + default: + ret = -ENOIOCTLCMD; + break; + } + + atomic_andnot(SGX_ENCL_IOCTL, &encl->flags); + + return ret; +} diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index 60d82e7537c8..842f9abba1c0 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -8,6 +8,7 @@ #include #include #include +#include "driver.h" #include "encls.h" struct sgx_epc_section sgx_epc_sections[SGX_MAX_EPC_SECTIONS]; @@ -193,6 +194,8 @@ static bool __init sgx_page_cache_init(void) static void __init sgx_init(void) { + int ret; + if (!boot_cpu_has(X86_FEATURE_SGX)) return; @@ -202,10 +205,17 @@ static void __init sgx_init(void) if (!sgx_page_reclaimer_init()) goto err_page_cache; + ret = sgx_drv_init(); + if (ret) + goto err_kthread; + return; +err_kthread: + kthread_stop(ksgxswapd_tsk); + err_page_cache: sgx_page_cache_teardown(); } -arch_initcall(sgx_init); +device_initcall(sgx_init); diff --git a/arch/x86/kernel/cpu/sgx/reclaim.c b/arch/x86/kernel/cpu/sgx/reclaim.c index 215371588a25..9e6d3e147aa2 100644 --- a/arch/x86/kernel/cpu/sgx/reclaim.c +++ b/arch/x86/kernel/cpu/sgx/reclaim.c @@ -10,6 +10,7 @@ #include #include #include "encls.h" +#include "driver.h" struct task_struct *ksgxswapd_tsk; From patchwork Tue Apr 21 21:53:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502355 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D37711667 for ; Tue, 21 Apr 2020 21:54:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C5BF92073A for ; Tue, 21 Apr 2020 21:54:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726613AbgDUVyf (ORCPT ); Tue, 21 Apr 2020 17:54:35 -0400 Received: from mga04.intel.com ([192.55.52.120]:33472 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726061AbgDUVyc (ORCPT ); Tue, 21 Apr 2020 17:54:32 -0400 IronPort-SDR: rmcYVMGDMkl//hbJH7dtvxxXmmDbXxYXsEmEi09gCxuhMNZumzX9Oh0XQj70Ok5kWM0LAcHo8O GZuLEfMtm5JA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:54:32 -0700 IronPort-SDR: nEWDR4USNE7AtVn2LTDj6epK/QBeMb3559BvAWruJq2Lu79JjGENOcmp3ltPxli+Ke7CCCvarW SwDi+d2YI+gQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260740" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:54:27 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Jarkko Sakkinen , linux-security-module@vger.kernel.org Subject: [PATCH v29 12/20] x86/sgx: Add provisioning Date: Wed, 22 Apr 2020 00:53:08 +0300 Message-Id: <20200421215316.56503-13-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org In order to provide a mechanism for devilering provisoning rights: 1. Add a new device file /dev/sgx/provision that works as a token for allowing an enclave to have the provisioning privileges. 2. Add a new ioctl called SGX_IOC_ENCLAVE_SET_ATTRIBUTE that accepts the following data structure: struct sgx_enclave_set_attribute { __u64 addr; __u64 attribute_fd; }; A daemon could sit on top of /dev/sgx/provision and send a file descriptor of this file to a process that needs to be able to provision enclaves. The way this API is used is straight-forward. Lets assume that dev_fd is a handle to /dev/sgx/enclave and prov_fd is a handle to /dev/sgx/provision. You would allow SGX_IOC_ENCLAVE_CREATE to initialize an enclave with the PROVISIONKEY attribute by params.addr = ; params.token_fd = prov_fd; ioctl(dev_fd, SGX_IOC_ENCLAVE_SET_ATTRIBUTE, ¶ms); Cc: linux-security-module@vger.kernel.org Suggested-by: Andy Lutomirski Signed-off-by: Jarkko Sakkinen --- arch/x86/include/uapi/asm/sgx.h | 11 ++++++++ arch/x86/kernel/cpu/sgx/driver.c | 14 ++++++++++ arch/x86/kernel/cpu/sgx/driver.h | 2 ++ arch/x86/kernel/cpu/sgx/ioctl.c | 47 ++++++++++++++++++++++++++++++++ 4 files changed, 74 insertions(+) diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h index 5edb08ab8fd0..57d0d30c79b3 100644 --- a/arch/x86/include/uapi/asm/sgx.h +++ b/arch/x86/include/uapi/asm/sgx.h @@ -25,6 +25,8 @@ enum sgx_page_flags { _IOWR(SGX_MAGIC, 0x01, struct sgx_enclave_add_pages) #define SGX_IOC_ENCLAVE_INIT \ _IOW(SGX_MAGIC, 0x02, struct sgx_enclave_init) +#define SGX_IOC_ENCLAVE_SET_ATTRIBUTE \ + _IOW(SGX_MAGIC, 0x03, struct sgx_enclave_set_attribute) /** * struct sgx_enclave_create - parameter structure for the @@ -63,4 +65,13 @@ struct sgx_enclave_init { __u64 sigstruct; }; +/** + * struct sgx_enclave_set_attribute - parameter structure for the + * %SGX_IOC_ENCLAVE_SET_ATTRIBUTE ioctl + * @attribute_fd: file handle of the attribute file in the securityfs + */ +struct sgx_enclave_set_attribute { + __u64 attribute_fd; +}; + #endif /* _UAPI_ASM_X86_SGX_H */ diff --git a/arch/x86/kernel/cpu/sgx/driver.c b/arch/x86/kernel/cpu/sgx/driver.c index b4aa7b9f8376..d90114cec1c3 100644 --- a/arch/x86/kernel/cpu/sgx/driver.c +++ b/arch/x86/kernel/cpu/sgx/driver.c @@ -150,6 +150,13 @@ static struct miscdevice sgx_dev_enclave = { .fops = &sgx_encl_fops, }; +static struct miscdevice sgx_dev_provision = { + .minor = MISC_DYNAMIC_MINOR, + .name = "provision", + .nodename = "sgx/provision", + .fops = &sgx_provision_fops, +}; + int __init sgx_drv_init(void) { unsigned int eax, ebx, ecx, edx; @@ -190,5 +197,12 @@ int __init sgx_drv_init(void) return ret; } + ret = misc_register(&sgx_dev_provision); + if (ret) { + pr_err("Creating /dev/sgx/provision failed with %d.\n", ret); + misc_deregister(&sgx_dev_enclave); + return ret; + } + return 0; } diff --git a/arch/x86/kernel/cpu/sgx/driver.h b/arch/x86/kernel/cpu/sgx/driver.h index e4063923115b..72747d01c046 100644 --- a/arch/x86/kernel/cpu/sgx/driver.h +++ b/arch/x86/kernel/cpu/sgx/driver.h @@ -23,6 +23,8 @@ extern u64 sgx_attributes_reserved_mask; extern u64 sgx_xfrm_reserved_mask; extern u32 sgx_xsave_size_tbl[64]; +extern const struct file_operations sgx_provision_fops; + long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg); int sgx_drv_init(void); diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c index 26d0425d7252..aea3e82a7ab9 100644 --- a/arch/x86/kernel/cpu/sgx/ioctl.c +++ b/arch/x86/kernel/cpu/sgx/ioctl.c @@ -653,6 +653,50 @@ static long sgx_ioc_enclave_init(struct sgx_encl *encl, void __user *arg) return ret; } +/** + * sgx_ioc_enclave_set_attribute - handler for %SGX_IOC_ENCLAVE_SET_ATTRIBUTE + * @filep: open file to /dev/sgx + * @arg: userspace pointer to a struct sgx_enclave_set_attribute instance + * + * Mark the enclave as being allowed to access a restricted attribute bit. + * The requested attribute is specified via the attribute_fd field in the + * provided struct sgx_enclave_set_attribute. The attribute_fd must be a + * handle to an SGX attribute file, e.g. “/dev/sgx/provision". + * + * Failure to explicitly request access to a restricted attribute will cause + * sgx_ioc_enclave_init() to fail. Currently, the only restricted attribute + * is access to the PROVISION_KEY. + * + * Note, access to the EINITTOKEN_KEY is disallowed entirely. + * + * Return: 0 on success, -errno otherwise + */ +static long sgx_ioc_enclave_set_attribute(struct sgx_encl *encl, + void __user *arg) +{ + struct sgx_enclave_set_attribute params; + struct file *attribute_file; + int ret; + + if (copy_from_user(¶ms, arg, sizeof(params))) + return -EFAULT; + + attribute_file = fget(params.attribute_fd); + if (!attribute_file) + return -EINVAL; + + if (attribute_file->f_op != &sgx_provision_fops) { + ret = -EINVAL; + goto out; + } + + encl->allowed_attributes |= SGX_ATTR_PROVISIONKEY; + ret = 0; + +out: + fput(attribute_file); + return ret; +} long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) { @@ -676,6 +720,9 @@ long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) case SGX_IOC_ENCLAVE_INIT: ret = sgx_ioc_enclave_init(encl, (void __user *)arg); break; + case SGX_IOC_ENCLAVE_SET_ATTRIBUTE: + ret = sgx_ioc_enclave_set_attribute(encl, (void __user *)arg); + break; default: ret = -ENOIOCTLCMD; break; From patchwork Tue Apr 21 21:53:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502359 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A20C2913 for ; Tue, 21 Apr 2020 21:54:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 82E1520724 for ; Tue, 21 Apr 2020 21:54:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726626AbgDUVym (ORCPT ); Tue, 21 Apr 2020 17:54:42 -0400 Received: from mga01.intel.com ([192.55.52.88]:30839 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726061AbgDUVyk (ORCPT ); Tue, 21 Apr 2020 17:54:40 -0400 IronPort-SDR: 3EftTwEvwcX3vFS9EnbIthQwamqgEYcIR6tU3M1vJCa8mX74xgg9saQ7YBdWJDW93s5M+BRE5a HxQZFJZMtXJg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:54:39 -0700 IronPort-SDR: pPhU3oowlksazJLOWGL7v8xQhsYHF6OXykeWnJP1XB3ODrhnSYjOnrN0L/S7KVAiXG/cXIeAKa hPzFzKqzq22g== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260770" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:54:33 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Jarkko Sakkinen , linux-mm@kvack.org Subject: [PATCH v29 13/20] x86/sgx: Add a page reclaimer Date: Wed, 22 Apr 2020 00:53:09 +0300 Message-Id: <20200421215316.56503-14-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org There is a limited amount of SGX reserved memory available. Therefore, some of it must be copied to the regular memory, and only subset kept in the SGX reserved memory. While kernel cannot directly access enclave memory, SGX provides ENCLS leaf functions to perform reclaiming functionality. This commits implements a page reclaimer by using these leaf functions, which picks the victim pages in LRU fashion from all enclaves running in an enclave's pages back to the SGX reserved memory. The thread ksgxswapd reclaims pages on the event when the number of free EPC pages goes below %SGX_NR_LOW_PAGES up until it reaches %SGX_NR_HIGH_PAGES. sgx_alloc_page() can now optionally reclaim pages with @reclaim boolean parameter. The caller must also supply owner for each page so that the reclaimer can access the associated enclaves. This is needed for locking, as most of the ENCLS leafs cannot be executed concurrently for an enclave, and accessing SECS, which is required to be resident when its child pages are being reclaimed. Cc: linux-mm@kvack.org Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson Signed-off-by: Jarkko Sakkinen --- arch/x86/kernel/cpu/sgx/driver.c | 1 + arch/x86/kernel/cpu/sgx/encl.c | 340 +++++++++++++++++++++++++- arch/x86/kernel/cpu/sgx/encl.h | 41 ++++ arch/x86/kernel/cpu/sgx/ioctl.c | 76 +++++- arch/x86/kernel/cpu/sgx/main.c | 61 ++++- arch/x86/kernel/cpu/sgx/reclaim.c | 388 ++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/sgx/sgx.h | 35 +++ 7 files changed, 934 insertions(+), 8 deletions(-) diff --git a/arch/x86/kernel/cpu/sgx/driver.c b/arch/x86/kernel/cpu/sgx/driver.c index d90114cec1c3..997a7f4117c5 100644 --- a/arch/x86/kernel/cpu/sgx/driver.c +++ b/arch/x86/kernel/cpu/sgx/driver.c @@ -32,6 +32,7 @@ static int sgx_open(struct inode *inode, struct file *file) atomic_set(&encl->flags, 0); kref_init(&encl->refcount); + INIT_LIST_HEAD(&encl->va_pages); INIT_RADIX_TREE(&encl->page_tree, GFP_KERNEL); mutex_init(&encl->lock); INIT_LIST_HEAD(&encl->mm_list); diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c index 17e44bf8fa56..fe7dbca40bb4 100644 --- a/arch/x86/kernel/cpu/sgx/encl.c +++ b/arch/x86/kernel/cpu/sgx/encl.c @@ -9,11 +9,86 @@ #include #include "arch.h" #include "encl.h" +#include "encls.h" #include "sgx.h" +static int __sgx_encl_eldu(struct sgx_encl_page *encl_page, + struct sgx_epc_page *epc_page, + struct sgx_epc_page *secs_page) +{ + unsigned long va_offset = SGX_ENCL_PAGE_VA_OFFSET(encl_page); + struct sgx_encl *encl = encl_page->encl; + struct sgx_pageinfo pginfo; + struct sgx_backing b; + pgoff_t page_index; + int ret; + + if (secs_page) + page_index = SGX_ENCL_PAGE_INDEX(encl_page); + else + page_index = PFN_DOWN(encl->size); + + ret = sgx_encl_get_backing(encl, page_index, &b); + if (ret) + return ret; + + pginfo.addr = SGX_ENCL_PAGE_ADDR(encl_page); + pginfo.contents = (unsigned long)kmap_atomic(b.contents); + pginfo.metadata = (unsigned long)kmap_atomic(b.pcmd) + + b.pcmd_offset; + + if (secs_page) + pginfo.secs = (u64)sgx_epc_addr(secs_page); + else + pginfo.secs = 0; + + ret = __eldu(&pginfo, sgx_epc_addr(epc_page), + sgx_epc_addr(encl_page->va_page->epc_page) + va_offset); + if (ret) { + if (encls_failed(ret)) + ENCLS_WARN(ret, "ELDU"); + + ret = -EFAULT; + } + + kunmap_atomic((void *)(unsigned long)(pginfo.metadata - b.pcmd_offset)); + kunmap_atomic((void *)(unsigned long)pginfo.contents); + + sgx_encl_put_backing(&b, false); + + return ret; +} + +static struct sgx_epc_page *sgx_encl_eldu(struct sgx_encl_page *encl_page, + struct sgx_epc_page *secs_page) +{ + unsigned long va_offset = SGX_ENCL_PAGE_VA_OFFSET(encl_page); + struct sgx_encl *encl = encl_page->encl; + struct sgx_epc_page *epc_page; + int ret; + + epc_page = sgx_alloc_page(encl_page, false); + if (IS_ERR(epc_page)) + return epc_page; + + ret = __sgx_encl_eldu(encl_page, epc_page, secs_page); + if (ret) { + sgx_free_page(epc_page); + return ERR_PTR(ret); + } + + sgx_free_va_slot(encl_page->va_page, va_offset); + list_move(&encl_page->va_page->list, &encl->va_pages); + encl_page->desc &= ~SGX_ENCL_PAGE_VA_OFFSET_MASK; + encl_page->epc_page = epc_page; + + return epc_page; +} + static struct sgx_encl_page *sgx_encl_load_page(struct sgx_encl *encl, unsigned long addr) { + struct sgx_epc_page *epc_page; struct sgx_encl_page *entry; unsigned int flags; @@ -33,10 +108,27 @@ static struct sgx_encl_page *sgx_encl_load_page(struct sgx_encl *encl, return ERR_PTR(-EFAULT); /* Page is already resident in the EPC. */ - if (entry->epc_page) + if (entry->epc_page) { + if (entry->desc & SGX_ENCL_PAGE_RECLAIMED) + return ERR_PTR(-EBUSY); + return entry; + } + + if (!(encl->secs.epc_page)) { + epc_page = sgx_encl_eldu(&encl->secs, NULL); + if (IS_ERR(epc_page)) + return ERR_CAST(epc_page); + } + + epc_page = sgx_encl_eldu(entry, encl->secs.epc_page); + if (IS_ERR(epc_page)) + return ERR_CAST(epc_page); - return ERR_PTR(-EFAULT); + encl->secs_child_cnt++; + sgx_mark_page_reclaimable(entry->epc_page); + + return entry; } static void sgx_mmu_notifier_release(struct mmu_notifier *mn, @@ -134,6 +226,9 @@ int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm) spin_lock(&encl->mm_lock); list_add_rcu(&encl_mm->list, &encl->mm_list); + /* Pairs with smp_rmb() in sgx_reclaimer_block(). */ + smp_wmb(); + encl->mm_list_version++; spin_unlock(&encl->mm_lock); return 0; @@ -181,6 +276,8 @@ static unsigned int sgx_vma_fault(struct vm_fault *vmf) goto out; } + sgx_encl_test_and_clear_young(vma->vm_mm, entry); + out: mutex_unlock(&encl->lock); return ret; @@ -280,6 +377,7 @@ int sgx_encl_find(struct mm_struct *mm, unsigned long addr, */ void sgx_encl_destroy(struct sgx_encl *encl) { + struct sgx_va_page *va_page; struct sgx_encl_page *entry; struct radix_tree_iter iter; void **slot; @@ -290,6 +388,13 @@ void sgx_encl_destroy(struct sgx_encl *encl) entry = *slot; if (entry->epc_page) { + /* + * The page and its radix tree entry cannot be freed + * if the page is being held by the reclaimer. + */ + if (sgx_unmark_page_reclaimable(entry->epc_page)) + continue; + sgx_free_page(entry->epc_page); encl->secs_child_cnt--; entry->epc_page = NULL; @@ -304,6 +409,19 @@ void sgx_encl_destroy(struct sgx_encl *encl) sgx_free_page(encl->secs.epc_page); encl->secs.epc_page = NULL; } + + /* + * The reclaimer is responsible for checking SGX_ENCL_DEAD before doing + * EWB, thus it's safe to free VA pages even if the reclaimer holds a + * reference to the enclave. + */ + while (!list_empty(&encl->va_pages)) { + va_page = list_first_entry(&encl->va_pages, struct sgx_va_page, + list); + list_del(&va_page->list); + sgx_free_page(va_page->epc_page); + kfree(va_page); + } } /** @@ -330,3 +448,221 @@ void sgx_encl_release(struct kref *ref) kfree(encl); } + +static struct page *sgx_encl_get_backing_page(struct sgx_encl *encl, + pgoff_t index) +{ + struct inode *inode = encl->backing->f_path.dentry->d_inode; + struct address_space *mapping = inode->i_mapping; + gfp_t gfpmask = mapping_gfp_mask(mapping); + + return shmem_read_mapping_page_gfp(mapping, index, gfpmask); +} + +/** + * sgx_encl_get_backing() - Pin the backing storage + * @encl: an enclave + * @page_index: enclave page index + * @backing: data for accessing backing storage for the page + * + * Pin the backing storage pages for storing the encrypted contents and Paging + * Crypto MetaData (PCMD) of an enclave page. + * + * Return: + * 0 on success, + * -errno otherwise. + */ +int sgx_encl_get_backing(struct sgx_encl *encl, unsigned long page_index, + struct sgx_backing *backing) +{ + pgoff_t pcmd_index = PFN_DOWN(encl->size) + 1 + (page_index >> 5); + struct page *contents; + struct page *pcmd; + + contents = sgx_encl_get_backing_page(encl, page_index); + if (IS_ERR(contents)) + return PTR_ERR(contents); + + pcmd = sgx_encl_get_backing_page(encl, pcmd_index); + if (IS_ERR(pcmd)) { + put_page(contents); + return PTR_ERR(pcmd); + } + + backing->page_index = page_index; + backing->contents = contents; + backing->pcmd = pcmd; + backing->pcmd_offset = + (page_index & (PAGE_SIZE / sizeof(struct sgx_pcmd) - 1)) * + sizeof(struct sgx_pcmd); + + return 0; +} + +/** + * sgx_encl_put_backing() - Unpin the backing storage + * @backing: data for accessing backing storage for the page + * @do_write: mark pages dirty + */ +void sgx_encl_put_backing(struct sgx_backing *backing, bool do_write) +{ + if (do_write) { + set_page_dirty(backing->pcmd); + set_page_dirty(backing->contents); + } + + put_page(backing->pcmd); + put_page(backing->contents); +} + +static int sgx_encl_test_and_clear_young_cb(pte_t *ptep, unsigned long addr, + void *data) +{ + pte_t pte; + int ret; + + ret = pte_young(*ptep); + if (ret) { + pte = pte_mkold(*ptep); + set_pte_at((struct mm_struct *)data, addr, ptep, pte); + } + + return ret; +} + +/** + * sgx_encl_test_and_clear_young() - Test and reset the accessed bit + * @mm: mm_struct that is checked + * @page: enclave page to be tested for recent access + * + * Checks the Access (A) bit from the PTE corresponding to the enclave page and + * clears it. + * + * Return: 1 if the page has been recently accessed and 0 if not. + */ +int sgx_encl_test_and_clear_young(struct mm_struct *mm, + struct sgx_encl_page *page) +{ + unsigned long addr = SGX_ENCL_PAGE_ADDR(page); + struct sgx_encl *encl = page->encl; + struct vm_area_struct *vma; + int ret; + + ret = sgx_encl_find(mm, addr, &vma); + if (ret) + return 0; + + if (encl != vma->vm_private_data) + return 0; + + ret = apply_to_page_range(vma->vm_mm, addr, PAGE_SIZE, + sgx_encl_test_and_clear_young_cb, vma->vm_mm); + if (ret < 0) + return 0; + + return ret; +} + +/** + * sgx_encl_reserve_page() - Reserve an enclave page + * @encl: an enclave + * @addr: a page address + * + * Load an enclave page and lock the enclave so that the page can be used by + * EDBG* and EMOD*. + * + * Return: + * an enclave page on success + * -EFAULT if the load fails + */ +struct sgx_encl_page *sgx_encl_reserve_page(struct sgx_encl *encl, + unsigned long addr) +{ + struct sgx_encl_page *entry; + + for ( ; ; ) { + mutex_lock(&encl->lock); + + entry = sgx_encl_load_page(encl, addr); + if (PTR_ERR(entry) != -EBUSY) + break; + + mutex_unlock(&encl->lock); + } + + if (IS_ERR(entry)) + mutex_unlock(&encl->lock); + + return entry; +} + +/** + * sgx_alloc_page - allocate a VA page + * + * Allocates an &sgx_epc_page instance and converts it to a VA page. + * + * Return: + * a &struct sgx_va_page instance, + * -errno otherwise + */ +struct sgx_epc_page *sgx_alloc_va_page(void) +{ + struct sgx_epc_page *epc_page; + int ret; + + epc_page = sgx_alloc_page(NULL, true); + if (IS_ERR(epc_page)) + return ERR_CAST(epc_page); + + ret = __epa(sgx_epc_addr(epc_page)); + if (ret) { + WARN_ONCE(1, "EPA returned %d (0x%x)", ret, ret); + sgx_free_page(epc_page); + return ERR_PTR(-EFAULT); + } + + return epc_page; +} + +/** + * sgx_alloc_va_slot - allocate a VA slot + * @va_page: a &struct sgx_va_page instance + * + * Allocates a slot from a &struct sgx_va_page instance. + * + * Return: offset of the slot inside the VA page + */ +unsigned int sgx_alloc_va_slot(struct sgx_va_page *va_page) +{ + int slot = find_first_zero_bit(va_page->slots, SGX_VA_SLOT_COUNT); + + if (slot < SGX_VA_SLOT_COUNT) + set_bit(slot, va_page->slots); + + return slot << 3; +} + +/** + * sgx_free_va_slot - free a VA slot + * @va_page: a &struct sgx_va_page instance + * @offset: offset of the slot inside the VA page + * + * Frees a slot from a &struct sgx_va_page instance. + */ +void sgx_free_va_slot(struct sgx_va_page *va_page, unsigned int offset) +{ + clear_bit(offset >> 3, va_page->slots); +} + +/** + * sgx_va_page_full - is the VA page full? + * @va_page: a &struct sgx_va_page instance + * + * Return: true if all slots have been taken + */ +bool sgx_va_page_full(struct sgx_va_page *va_page) +{ + int slot = find_first_zero_bit(va_page->slots, SGX_VA_SLOT_COUNT); + + return slot == SGX_VA_SLOT_COUNT; +} diff --git a/arch/x86/kernel/cpu/sgx/encl.h b/arch/x86/kernel/cpu/sgx/encl.h index 1d1bc5d590ee..f0f72e591244 100644 --- a/arch/x86/kernel/cpu/sgx/encl.h +++ b/arch/x86/kernel/cpu/sgx/encl.h @@ -19,6 +19,10 @@ /** * enum sgx_encl_page_desc - defines bits for an enclave page's descriptor + * %SGX_ENCL_PAGE_RECLAIMED: The page is in the process of being + * reclaimed. + * %SGX_ENCL_PAGE_VA_OFFSET_MASK: Holds the offset in the Version Array + * (VA) page for a swapped page. * %SGX_ENCL_PAGE_ADDR_MASK: Holds the virtual address of the page. * * The page address for SECS is zero and is used by the subsystem to recognize @@ -26,16 +30,23 @@ */ enum sgx_encl_page_desc { /* Bits 11:3 are available when the page is not swapped. */ + SGX_ENCL_PAGE_RECLAIMED = BIT(3), + SGX_ENCL_PAGE_VA_OFFSET_MASK = GENMASK_ULL(11, 3), SGX_ENCL_PAGE_ADDR_MASK = PAGE_MASK, }; #define SGX_ENCL_PAGE_ADDR(page) \ ((page)->desc & SGX_ENCL_PAGE_ADDR_MASK) +#define SGX_ENCL_PAGE_VA_OFFSET(page) \ + ((page)->desc & SGX_ENCL_PAGE_VA_OFFSET_MASK) +#define SGX_ENCL_PAGE_INDEX(page) \ + PFN_DOWN((page)->desc - (page)->encl->base) struct sgx_encl_page { unsigned long desc; unsigned long vm_max_prot_bits; struct sgx_epc_page *epc_page; + struct sgx_va_page *va_page; struct sgx_encl *encl; }; @@ -63,17 +74,27 @@ struct sgx_encl { struct mutex lock; struct list_head mm_list; spinlock_t mm_lock; + unsigned long mm_list_version; struct file *backing; struct kref refcount; struct srcu_struct srcu; unsigned long base; unsigned long size; unsigned long ssaframesize; + struct list_head va_pages; struct radix_tree_root page_tree; struct sgx_encl_page secs; cpumask_t cpumask; }; +#define SGX_VA_SLOT_COUNT 512 + +struct sgx_va_page { + struct sgx_epc_page *epc_page; + DECLARE_BITMAP(slots, SGX_VA_SLOT_COUNT); + struct list_head list; +}; + extern const struct vm_operations_struct sgx_vm_ops; int sgx_encl_find(struct mm_struct *mm, unsigned long addr, @@ -84,4 +105,24 @@ int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm); int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start, unsigned long end, unsigned long vm_prot_bits); +struct sgx_backing { + pgoff_t page_index; + struct page *contents; + struct page *pcmd; + unsigned long pcmd_offset; +}; + +int sgx_encl_get_backing(struct sgx_encl *encl, unsigned long page_index, + struct sgx_backing *backing); +void sgx_encl_put_backing(struct sgx_backing *backing, bool do_write); +int sgx_encl_test_and_clear_young(struct mm_struct *mm, + struct sgx_encl_page *page); +struct sgx_encl_page *sgx_encl_reserve_page(struct sgx_encl *encl, + unsigned long addr); + +struct sgx_epc_page *sgx_alloc_va_page(void); +unsigned int sgx_alloc_va_slot(struct sgx_va_page *va_page); +void sgx_free_va_slot(struct sgx_va_page *va_page, unsigned int offset); +bool sgx_va_page_full(struct sgx_va_page *va_page); + #endif /* _X86_ENCL_H */ diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c index aea3e82a7ab9..3af0596530a8 100644 --- a/arch/x86/kernel/cpu/sgx/ioctl.c +++ b/arch/x86/kernel/cpu/sgx/ioctl.c @@ -19,6 +19,43 @@ /* A per-cpu cache for the last known values of IA32_SGXLEPUBKEYHASHx MSRs. */ static DEFINE_PER_CPU(u64 [4], sgx_lepubkeyhash_cache); +static struct sgx_va_page *sgx_encl_grow(struct sgx_encl *encl) +{ + struct sgx_va_page *va_page = NULL; + void *err; + + BUILD_BUG_ON(SGX_VA_SLOT_COUNT != + (SGX_ENCL_PAGE_VA_OFFSET_MASK >> 3) + 1); + + if (!(encl->page_cnt % SGX_VA_SLOT_COUNT)) { + va_page = kzalloc(sizeof(*va_page), GFP_KERNEL); + if (!va_page) + return ERR_PTR(-ENOMEM); + + va_page->epc_page = sgx_alloc_va_page(); + if (IS_ERR(va_page->epc_page)) { + err = ERR_CAST(va_page->epc_page); + kfree(va_page); + return err; + } + + WARN_ON_ONCE(encl->page_cnt % SGX_VA_SLOT_COUNT); + } + encl->page_cnt++; + return va_page; +} + +static void sgx_encl_shrink(struct sgx_encl *encl, struct sgx_va_page *va_page) +{ + encl->page_cnt--; + + if (va_page) { + sgx_free_page(va_page->epc_page); + list_del(&va_page->list); + kfree(va_page); + } +} + static u32 sgx_calc_ssaframesize(u32 miscselect, u64 xfrm) { u32 size_max = PAGE_SIZE; @@ -114,6 +151,7 @@ static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs) { unsigned long encl_size = secs->size + PAGE_SIZE; struct sgx_epc_page *secs_epc; + struct sgx_va_page *va_page; unsigned long ssaframesize; struct sgx_pageinfo pginfo; struct sgx_secinfo secinfo; @@ -123,20 +161,29 @@ static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs) if (atomic_read(&encl->flags) & SGX_ENCL_CREATED) return -EINVAL; + va_page = sgx_encl_grow(encl); + if (IS_ERR(va_page)) + return PTR_ERR(va_page); + else if (va_page) + list_add(&va_page->list, &encl->va_pages); + ssaframesize = sgx_calc_ssaframesize(secs->miscselect, secs->xfrm); if (sgx_validate_secs(secs, ssaframesize)) { pr_debug("invalid SECS\n"); - return -EINVAL; + ret = -EINVAL; + goto err_out_shrink; } backing = shmem_file_setup("SGX backing", encl_size + (encl_size >> 5), VM_NORESERVE); - if (IS_ERR(backing)) - return PTR_ERR(backing); + if (IS_ERR(backing)) { + ret = PTR_ERR(backing); + goto err_out_shrink; + } encl->backing = backing; - secs_epc = sgx_try_alloc_page(); + secs_epc = sgx_alloc_page(&encl->secs, true); if (IS_ERR(secs_epc)) { ret = PTR_ERR(secs_epc); goto err_out_backing; @@ -183,6 +230,9 @@ static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs) fput(encl->backing); encl->backing = NULL; +err_out_shrink: + sgx_encl_shrink(encl, va_page); + return ret; } @@ -319,13 +369,14 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long src, { struct sgx_encl_page *encl_page; struct sgx_epc_page *epc_page; + struct sgx_va_page *va_page; int ret; encl_page = sgx_encl_page_alloc(encl, offset, secinfo->flags); if (IS_ERR(encl_page)) return PTR_ERR(encl_page); - epc_page = sgx_try_alloc_page(); + epc_page = sgx_alloc_page(encl_page, true); if (IS_ERR(epc_page)) { kfree(encl_page); return PTR_ERR(epc_page); @@ -337,9 +388,22 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long src, goto err_out_free; } + va_page = sgx_encl_grow(encl); + if (IS_ERR(va_page)) { + ret = PTR_ERR(va_page); + goto err_out_free; + } + down_read(¤t->mm->mmap_sem); mutex_lock(&encl->lock); + /* + * Adding to encl->va_pages must be done under encl->lock. Ditto for + * deleting (via sgx_encl_shrink()) in the error path. + */ + if (va_page) + list_add(&va_page->list, &encl->va_pages); + /* * Insert prior to EADD in case of OOM. EADD modifies MRENCLAVE, i.e. * can't be gracefully unwound, while failure on EADD/EXTEND is limited @@ -370,6 +434,7 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long src, goto err_out; } + sgx_mark_page_reclaimable(encl_page->epc_page); mutex_unlock(&encl->lock); up_read(¤t->mm->mmap_sem); return ret; @@ -379,6 +444,7 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long src, PFN_DOWN(encl_page->desc)); err_out_unlock: + sgx_encl_shrink(encl, va_page); mutex_unlock(&encl->lock); up_read(¤t->mm->mmap_sem); diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index 842f9abba1c0..5ce77e554676 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -23,6 +23,8 @@ static struct sgx_epc_page *__sgx_try_alloc_page(struct sgx_epc_section *section page = list_first_entry(§ion->page_list, struct sgx_epc_page, list); list_del_init(&page->list); + section->free_cnt--; + return page; } @@ -54,23 +56,79 @@ struct sgx_epc_page *sgx_try_alloc_page(void) return ERR_PTR(-ENOMEM); } +/** + * sgx_alloc_page() - Allocate an EPC page + * @owner: the owner of the EPC page + * @reclaim: reclaim pages if necessary + * + * Try to grab a page from the free EPC page list. If there is a free page + * available, it is returned to the caller. The @reclaim parameter hints + * the EPC memory manager to swap pages when required. + * + * Return: + * a pointer to a &struct sgx_epc_page instance, + * -errno on error + */ +struct sgx_epc_page *sgx_alloc_page(void *owner, bool reclaim) +{ + struct sgx_epc_page *entry; + + for ( ; ; ) { + entry = sgx_try_alloc_page(); + if (!IS_ERR(entry)) { + entry->owner = owner; + break; + } + + if (list_empty(&sgx_active_page_list)) + return ERR_PTR(-ENOMEM); + + if (!reclaim) { + entry = ERR_PTR(-EBUSY); + break; + } + + if (signal_pending(current)) { + entry = ERR_PTR(-ERESTARTSYS); + break; + } + + sgx_reclaim_pages(); + schedule(); + } + + if (sgx_should_reclaim(SGX_NR_LOW_PAGES)) + wake_up(&ksgxswapd_waitq); + + return entry; +} + /** * sgx_free_page() - Free an EPC page * @page: pointer a previously allocated EPC page * - * EREMOVE an EPC page and insert it back to the list of free pages. + * EREMOVE an EPC page and insert it back to the list of free pages. The page + * must not be reclaimable. */ void sgx_free_page(struct sgx_epc_page *page) { struct sgx_epc_section *section = sgx_epc_section(page); int ret; + /* + * Don't take sgx_active_page_list_lock when asserting the page isn't + * reclaimable, missing a WARN in the very rare case is preferable to + * unnecessarily taking a global lock in the common case. + */ + WARN_ON_ONCE(page->desc & SGX_EPC_PAGE_RECLAIMABLE); + ret = __eremove(sgx_epc_addr(page)); if (WARN_ONCE(ret, "EREMOVE returned %d (0x%x)", ret, ret)) return; spin_lock(§ion->lock); list_add_tail(&page->list, §ion->page_list); + section->free_cnt++; spin_unlock(§ion->lock); } @@ -121,6 +179,7 @@ static bool __init sgx_alloc_epc_section(u64 addr, u64 size, list_add_tail(&page->list, §ion->unsanitized_page_list); } + section->free_cnt = nr_pages; return true; err_out: diff --git a/arch/x86/kernel/cpu/sgx/reclaim.c b/arch/x86/kernel/cpu/sgx/reclaim.c index 9e6d3e147aa2..fb521f314fb7 100644 --- a/arch/x86/kernel/cpu/sgx/reclaim.c +++ b/arch/x86/kernel/cpu/sgx/reclaim.c @@ -9,10 +9,14 @@ #include #include #include +#include "encl.h" #include "encls.h" #include "driver.h" struct task_struct *ksgxswapd_tsk; +DECLARE_WAIT_QUEUE_HEAD(ksgxswapd_waitq); +LIST_HEAD(sgx_active_page_list); +DEFINE_SPINLOCK(sgx_active_page_list_lock); static void sgx_sanitize_section(struct sgx_epc_section *section) { @@ -66,6 +70,20 @@ static int ksgxswapd(void *p) WARN(1, "EPC section %d has unsanitized pages.\n", i); } + while (!kthread_should_stop()) { + if (try_to_freeze()) + continue; + + wait_event_freezable(ksgxswapd_waitq, + kthread_should_stop() || + sgx_should_reclaim(SGX_NR_HIGH_PAGES)); + + if (sgx_should_reclaim(SGX_NR_HIGH_PAGES)) + sgx_reclaim_pages(); + + cond_resched(); + } + return 0; } @@ -81,3 +99,373 @@ bool __init sgx_page_reclaimer_init(void) return true; } + +/** + * sgx_mark_page_reclaimable() - Mark a page as reclaimable + * @page: EPC page + * + * Mark a page as reclaimable and add it to the active page list. Pages + * are automatically removed from the active list when freed. + */ +void sgx_mark_page_reclaimable(struct sgx_epc_page *page) +{ + spin_lock(&sgx_active_page_list_lock); + page->desc |= SGX_EPC_PAGE_RECLAIMABLE; + list_add_tail(&page->list, &sgx_active_page_list); + spin_unlock(&sgx_active_page_list_lock); +} + +/** + * sgx_unmark_page_reclaimable() - Remove a page from the reclaim list + * @page: EPC page + * + * Clear the reclaimable flag and remove the page from the active page list. + * + * Return: + * 0 on success, + * -EBUSY if the page is in the process of being reclaimed + */ +int sgx_unmark_page_reclaimable(struct sgx_epc_page *page) +{ + /* + * Remove the page from the active list if necessary. If the page + * is actively being reclaimed, i.e. RECLAIMABLE is set but the + * page isn't on the active list, return -EBUSY as we can't free + * the page at this time since it is "owned" by the reclaimer. + */ + spin_lock(&sgx_active_page_list_lock); + if (page->desc & SGX_EPC_PAGE_RECLAIMABLE) { + if (list_empty(&page->list)) { + spin_unlock(&sgx_active_page_list_lock); + return -EBUSY; + } + list_del(&page->list); + page->desc &= ~SGX_EPC_PAGE_RECLAIMABLE; + } + spin_unlock(&sgx_active_page_list_lock); + + return 0; +} + +static bool sgx_reclaimer_age(struct sgx_epc_page *epc_page) +{ + struct sgx_encl_page *page = epc_page->owner; + struct sgx_encl *encl = page->encl; + struct sgx_encl_mm *encl_mm; + bool ret = true; + int idx; + + idx = srcu_read_lock(&encl->srcu); + + list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) { + if (!mmget_not_zero(encl_mm->mm)) + continue; + + down_read(&encl_mm->mm->mmap_sem); + ret = !sgx_encl_test_and_clear_young(encl_mm->mm, page); + up_read(&encl_mm->mm->mmap_sem); + + mmput_async(encl_mm->mm); + + if (!ret || (atomic_read(&encl->flags) & SGX_ENCL_DEAD)) + break; + } + + srcu_read_unlock(&encl->srcu, idx); + + if (!ret && !(atomic_read(&encl->flags) & SGX_ENCL_DEAD)) + return false; + + return true; +} + +static void sgx_reclaimer_block(struct sgx_epc_page *epc_page) +{ + struct sgx_encl_page *page = epc_page->owner; + unsigned long addr = SGX_ENCL_PAGE_ADDR(page); + struct sgx_encl *encl = page->encl; + unsigned long mm_list_version; + struct sgx_encl_mm *encl_mm; + struct vm_area_struct *vma; + int idx, ret; + + do { + mm_list_version = encl->mm_list_version; + + /* Pairs with smp_rmb() in sgx_encl_mm_add(). */ + smp_rmb(); + + idx = srcu_read_lock(&encl->srcu); + + list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) { + if (!mmget_not_zero(encl_mm->mm)) + continue; + + down_read(&encl_mm->mm->mmap_sem); + + ret = sgx_encl_find(encl_mm->mm, addr, &vma); + if (!ret && encl == vma->vm_private_data) + zap_vma_ptes(vma, addr, PAGE_SIZE); + + up_read(&encl_mm->mm->mmap_sem); + + mmput_async(encl_mm->mm); + } + + srcu_read_unlock(&encl->srcu, idx); + } while (unlikely(encl->mm_list_version != mm_list_version)); + + mutex_lock(&encl->lock); + + if (!(atomic_read(&encl->flags) & SGX_ENCL_DEAD)) { + ret = __eblock(sgx_epc_addr(epc_page)); + if (encls_failed(ret)) + ENCLS_WARN(ret, "EBLOCK"); + } + + mutex_unlock(&encl->lock); +} + +static int __sgx_encl_ewb(struct sgx_epc_page *epc_page, void *va_slot, + struct sgx_backing *backing) +{ + struct sgx_pageinfo pginfo; + int ret; + + pginfo.addr = 0; + pginfo.secs = 0; + + pginfo.contents = (unsigned long)kmap_atomic(backing->contents); + pginfo.metadata = (unsigned long)kmap_atomic(backing->pcmd) + + backing->pcmd_offset; + + ret = __ewb(&pginfo, sgx_epc_addr(epc_page), va_slot); + + kunmap_atomic((void *)(unsigned long)(pginfo.metadata - + backing->pcmd_offset)); + kunmap_atomic((void *)(unsigned long)pginfo.contents); + + return ret; +} + +static void sgx_ipi_cb(void *info) +{ +} + +static const cpumask_t *sgx_encl_ewb_cpumask(struct sgx_encl *encl) +{ + cpumask_t *cpumask = &encl->cpumask; + struct sgx_encl_mm *encl_mm; + int idx; + + /* + * Can race with sgx_encl_mm_add(), but ETRACK has already been + * executed, which means that the CPUs running in the new mm will enter + * into the enclave with a fresh epoch. + */ + cpumask_clear(cpumask); + + idx = srcu_read_lock(&encl->srcu); + + list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) { + if (!mmget_not_zero(encl_mm->mm)) + continue; + + cpumask_or(cpumask, cpumask, mm_cpumask(encl_mm->mm)); + + mmput_async(encl_mm->mm); + } + + srcu_read_unlock(&encl->srcu, idx); + + return cpumask; +} + +static void sgx_encl_ewb(struct sgx_epc_page *epc_page, + struct sgx_backing *backing) +{ + struct sgx_encl_page *encl_page = epc_page->owner; + struct sgx_encl *encl = encl_page->encl; + struct sgx_va_page *va_page; + unsigned int va_offset; + void *va_slot; + int ret; + + encl_page->desc &= ~SGX_ENCL_PAGE_RECLAIMED; + + va_page = list_first_entry(&encl->va_pages, struct sgx_va_page, + list); + va_offset = sgx_alloc_va_slot(va_page); + va_slot = sgx_epc_addr(va_page->epc_page) + va_offset; + if (sgx_va_page_full(va_page)) + list_move_tail(&va_page->list, &encl->va_pages); + + ret = __sgx_encl_ewb(epc_page, va_slot, backing); + if (ret == SGX_NOT_TRACKED) { + ret = __etrack(sgx_epc_addr(encl->secs.epc_page)); + if (ret) { + if (encls_failed(ret)) + ENCLS_WARN(ret, "ETRACK"); + } + + ret = __sgx_encl_ewb(epc_page, va_slot, backing); + if (ret == SGX_NOT_TRACKED) { + /* + * Slow path, send IPIs to kick cpus out of the + * enclave. Note, it's imperative that the cpu + * mask is generated *after* ETRACK, else we'll + * miss cpus that entered the enclave between + * generating the mask and incrementing epoch. + */ + on_each_cpu_mask(sgx_encl_ewb_cpumask(encl), + sgx_ipi_cb, NULL, 1); + ret = __sgx_encl_ewb(epc_page, va_slot, backing); + } + } + + if (ret) { + if (encls_failed(ret)) + ENCLS_WARN(ret, "EWB"); + + sgx_free_va_slot(va_page, va_offset); + } else { + encl_page->desc |= va_offset; + encl_page->va_page = va_page; + } +} + +static void sgx_reclaimer_write(struct sgx_epc_page *epc_page, + struct sgx_backing *backing) +{ + struct sgx_encl_page *encl_page = epc_page->owner; + struct sgx_encl *encl = encl_page->encl; + struct sgx_backing secs_backing; + int ret; + + mutex_lock(&encl->lock); + + if (atomic_read(&encl->flags) & SGX_ENCL_DEAD) { + ret = __eremove(sgx_epc_addr(epc_page)); + ENCLS_WARN(ret, "EREMOVE returned %d\n"); + } else { + sgx_encl_ewb(epc_page, backing); + } + + encl_page->epc_page = NULL; + encl->secs_child_cnt--; + + if (!encl->secs_child_cnt) { + if (atomic_read(&encl->flags) & SGX_ENCL_DEAD) { + sgx_free_page(encl->secs.epc_page); + encl->secs.epc_page = NULL; + } else if (atomic_read(&encl->flags) & SGX_ENCL_INITIALIZED) { + ret = sgx_encl_get_backing(encl, PFN_DOWN(encl->size), + &secs_backing); + if (ret) + goto out; + + sgx_encl_ewb(encl->secs.epc_page, &secs_backing); + + sgx_free_page(encl->secs.epc_page); + encl->secs.epc_page = NULL; + + sgx_encl_put_backing(&secs_backing, true); + } + } + +out: + mutex_unlock(&encl->lock); +} + +/** + * sgx_reclaim_pages() - Reclaim EPC pages from the consumers + * + * Take a fixed number of pages from the head of the active page pool and + * reclaim them to the enclave's private shmem files. Skip the pages, which + * have been accessed since the last scan. Move those pages to the tail of + * active page pool so that the pages get scanned in LRU like fashion. + */ +void sgx_reclaim_pages(void) +{ + struct sgx_epc_page *chunk[SGX_NR_TO_SCAN]; + struct sgx_backing backing[SGX_NR_TO_SCAN]; + struct sgx_epc_section *section; + struct sgx_encl_page *encl_page; + struct sgx_epc_page *epc_page; + int cnt = 0; + int ret; + int i; + + spin_lock(&sgx_active_page_list_lock); + for (i = 0; i < SGX_NR_TO_SCAN; i++) { + if (list_empty(&sgx_active_page_list)) + break; + + epc_page = list_first_entry(&sgx_active_page_list, + struct sgx_epc_page, list); + list_del_init(&epc_page->list); + encl_page = epc_page->owner; + + if (kref_get_unless_zero(&encl_page->encl->refcount) != 0) + chunk[cnt++] = epc_page; + else + /* The owner is freeing the page. No need to add the + * page back to the list of reclaimable pages. + */ + epc_page->desc &= ~SGX_EPC_PAGE_RECLAIMABLE; + } + spin_unlock(&sgx_active_page_list_lock); + + for (i = 0; i < cnt; i++) { + epc_page = chunk[i]; + encl_page = epc_page->owner; + + if (!sgx_reclaimer_age(epc_page)) + goto skip; + + ret = sgx_encl_get_backing(encl_page->encl, + SGX_ENCL_PAGE_INDEX(encl_page), + &backing[i]); + if (ret) + goto skip; + + mutex_lock(&encl_page->encl->lock); + encl_page->desc |= SGX_ENCL_PAGE_RECLAIMED; + mutex_unlock(&encl_page->encl->lock); + continue; + +skip: + kref_put(&encl_page->encl->refcount, sgx_encl_release); + + spin_lock(&sgx_active_page_list_lock); + list_add_tail(&epc_page->list, &sgx_active_page_list); + spin_unlock(&sgx_active_page_list_lock); + + chunk[i] = NULL; + } + + for (i = 0; i < cnt; i++) { + epc_page = chunk[i]; + if (epc_page) + sgx_reclaimer_block(epc_page); + } + + for (i = 0; i < cnt; i++) { + epc_page = chunk[i]; + if (!epc_page) + continue; + + encl_page = epc_page->owner; + sgx_reclaimer_write(epc_page, &backing[i]); + sgx_encl_put_backing(&backing[i], true); + + kref_put(&encl_page->encl->refcount, sgx_encl_release); + epc_page->desc &= ~SGX_EPC_PAGE_RECLAIMABLE; + + section = sgx_epc_section(epc_page); + spin_lock(§ion->lock); + list_add_tail(&epc_page->list, §ion->page_list); + section->free_cnt++; + spin_unlock(§ion->lock); + } +} diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index aa85f85412d8..0c481e6f2c95 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -15,6 +15,7 @@ struct sgx_epc_page { unsigned long desc; + struct sgx_encl_page *owner; struct list_head list; }; @@ -29,6 +30,7 @@ struct sgx_epc_page { struct sgx_epc_section { unsigned long pa; void *va; + unsigned long free_cnt; struct list_head page_list; struct list_head unsanitized_page_list; spinlock_t lock; @@ -40,9 +42,14 @@ struct sgx_epc_section { * physical memory. The existing and near-future * hardware defines at most eight sections, hence * three bits to hold a section. + * %SGX_EPC_PAGE_RECLAIMABLE: The page has been been marked as reclaimable. + * Pages need to be colored this way because a page + * can be out of the active page list in the + * process of being swapped out. */ enum sgx_epc_page_desc { SGX_EPC_SECTION_MASK = GENMASK_ULL(3, 0), + SGX_EPC_PAGE_RECLAIMABLE = BIT(4), /* bits 12-63 are reserved for the physical page address of the page */ }; @@ -62,12 +69,40 @@ static inline void *sgx_epc_addr(struct sgx_epc_page *page) return section->va + (page->desc & PAGE_MASK) - section->pa; } +#define SGX_NR_TO_SCAN 16 +#define SGX_NR_LOW_PAGES 32 +#define SGX_NR_HIGH_PAGES 64 + extern int sgx_nr_epc_sections; extern struct task_struct *ksgxswapd_tsk; +extern struct wait_queue_head(ksgxswapd_waitq); +extern struct list_head sgx_active_page_list; +extern spinlock_t sgx_active_page_list_lock; + +static inline unsigned long sgx_nr_free_pages(void) +{ + unsigned long cnt = 0; + int i; + + for (i = 0; i < sgx_nr_epc_sections; i++) + cnt += sgx_epc_sections[i].free_cnt; + + return cnt; +} + +static inline bool sgx_should_reclaim(unsigned long watermark) +{ + return sgx_nr_free_pages() < watermark && + !list_empty(&sgx_active_page_list); +} bool __init sgx_page_reclaimer_init(void); +void sgx_mark_page_reclaimable(struct sgx_epc_page *page); +int sgx_unmark_page_reclaimable(struct sgx_epc_page *page); +void sgx_reclaim_pages(void); struct sgx_epc_page *sgx_try_alloc_page(void); +struct sgx_epc_page *sgx_alloc_page(void *owner, bool reclaim); void sgx_free_page(struct sgx_epc_page *page); #endif /* _X86_SGX_H */ From patchwork Tue Apr 21 21:53:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502363 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BE8CC1575 for ; Tue, 21 Apr 2020 21:54:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B10C7206D9 for ; Tue, 21 Apr 2020 21:54:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726364AbgDUVyr (ORCPT ); Tue, 21 Apr 2020 17:54:47 -0400 Received: from mga12.intel.com ([192.55.52.136]:30191 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726648AbgDUVyp (ORCPT ); Tue, 21 Apr 2020 17:54:45 -0400 IronPort-SDR: 8arrQmvauPpIybtcLQi8Ybv3IwOqaw5VuFDMnJSoDW96E4cT8f3YzxYYFZdbZ5+SLK8u4A1Ave b84Y/56fQK+A== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:54:44 -0700 IronPort-SDR: CWDRjm4I3cnvaBEAki0NW5SQ2mA51g3xTb+TTOM4psprfSh+BLp9lF+dbvNzyuFgLKE67A2c5Z dOGOr8v7lKqw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260785" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:54:40 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Jarkko Sakkinen Subject: [PATCH v29 14/20] x86/sgx: ptrace() support for the SGX driver Date: Wed, 22 Apr 2020 00:53:10 +0300 Message-Id: <20200421215316.56503-15-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org Add VMA callbacks for ptrace() that can be used with debug enclaves. With debug enclaves data can be read and write the memory word at a time by using ENCLS(EDBGRD) and ENCLS(EDBGWR) leaf instructions. Signed-off-by: Jarkko Sakkinen --- arch/x86/kernel/cpu/sgx/encl.c | 88 ++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c index fe7dbca40bb4..0c5ea2968868 100644 --- a/arch/x86/kernel/cpu/sgx/encl.c +++ b/arch/x86/kernel/cpu/sgx/encl.c @@ -326,6 +326,7 @@ int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start, return 0; } + static int sgx_vma_mprotect(struct vm_area_struct *vma, unsigned long start, unsigned long end, unsigned long prot) { @@ -333,10 +334,97 @@ static int sgx_vma_mprotect(struct vm_area_struct *vma, unsigned long start, calc_vm_prot_bits(prot, 0)); } +static int sgx_edbgrd(struct sgx_encl *encl, struct sgx_encl_page *page, + unsigned long addr, void *data) +{ + unsigned long offset = addr & ~PAGE_MASK; + int ret; + + + ret = __edbgrd(sgx_epc_addr(page->epc_page) + offset, data); + if (ret) + return -EIO; + + return 0; +} + +static int sgx_edbgwr(struct sgx_encl *encl, struct sgx_encl_page *page, + unsigned long addr, void *data) +{ + unsigned long offset = addr & ~PAGE_MASK; + int ret; + + ret = __edbgwr(sgx_epc_addr(page->epc_page) + offset, data); + if (ret) + return -EIO; + + return 0; +} + +static int sgx_vma_access(struct vm_area_struct *vma, unsigned long addr, + void *buf, int len, int write) +{ + struct sgx_encl *encl = vma->vm_private_data; + struct sgx_encl_page *entry = NULL; + char data[sizeof(unsigned long)]; + unsigned long align; + unsigned int flags; + int offset; + int cnt; + int ret = 0; + int i; + + /* If process was forked, VMA is still there but vm_private_data is set + * to NULL. + */ + if (!encl) + return -EFAULT; + + flags = atomic_read(&encl->flags); + + if (!(flags & SGX_ENCL_DEBUG) || !(flags & SGX_ENCL_INITIALIZED) || + (flags & SGX_ENCL_DEAD)) + return -EFAULT; + + for (i = 0; i < len; i += cnt) { + entry = sgx_encl_reserve_page(encl, (addr + i) & PAGE_MASK); + if (IS_ERR(entry)) { + ret = PTR_ERR(entry); + break; + } + + align = ALIGN_DOWN(addr + i, sizeof(unsigned long)); + offset = (addr + i) & (sizeof(unsigned long) - 1); + cnt = sizeof(unsigned long) - offset; + cnt = min(cnt, len - i); + + ret = sgx_edbgrd(encl, entry, align, data); + if (ret) + goto out; + + if (write) { + memcpy(data + offset, buf + i, cnt); + ret = sgx_edbgwr(encl, entry, align, data); + if (ret) + goto out; + } else + memcpy(buf + i, data + offset, cnt); + +out: + mutex_unlock(&encl->lock); + + if (ret) + break; + } + + return ret < 0 ? ret : i; +} + const struct vm_operations_struct sgx_vm_ops = { .open = sgx_vma_open, .fault = sgx_vma_fault, .may_mprotect = sgx_vma_mprotect, + .access = sgx_vma_access, }; /** From patchwork Tue Apr 21 21:53:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502365 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2174C913 for ; Tue, 21 Apr 2020 21:54:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 08DDA20724 for ; Tue, 21 Apr 2020 21:54:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726648AbgDUVyw (ORCPT ); Tue, 21 Apr 2020 17:54:52 -0400 Received: from mga04.intel.com ([192.55.52.120]:33517 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726328AbgDUVyv (ORCPT ); Tue, 21 Apr 2020 17:54:51 -0400 IronPort-SDR: OvL9mcjUY++aRl12T0pvwOBTY0J417Et8fuybQq/aV2BNf/YfmRR7MFn6ePpBlxtB/CEk/cjgr jMcyMmjfMRjA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:54:50 -0700 IronPort-SDR: gfOCYz3xDGNnBxhjabDQqh4R+4L8sNQICkE67HXdihE939urT/JPlrZ5GJCKQ/NT+phtCgogXH vv4IDRR8cU2A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260805" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:54:45 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Andy Lutomirski , Jarkko Sakkinen Subject: [PATCH v29 15/20] x86/vdso: Add support for exception fixup in vDSO functions Date: Wed, 22 Apr 2020 00:53:11 +0300 Message-Id: <20200421215316.56503-16-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org From: Sean Christopherson The basic concept and implementation is very similar to the kernel's exception fixup mechanism. The key differences are that the kernel handler is hardcoded and the fixup entry addresses are relative to the overall table as opposed to individual entries. Hardcoding the kernel handler avoids the need to figure out how to get userspace code to point at a kernel function. Given that the expected usage is to propagate information to userspace, dumping all fault information into registers is likely the desired behavior for the vast majority of yet-to-be-created functions. Use registers DI, SI and DX to communicate fault information, which follows Linux's ABI for register consumption and hopefully avoids conflict with hardware features that might leverage the fixup capabilities, e.g. register usage for SGX instructions was at least partially designed with calling conventions in mind. Making fixup addresses relative to the overall table allows the table to be stripped from the final vDSO image (it's a kernel construct) without complicating the offset logic, e.g. entry-relative addressing would also need to account for the table's location relative to the image. Regarding stripping the table, modify vdso2c to extract the table from the raw, a.k.a. unstripped, data and dump it as a standalone byte array in the resulting .c file. The original base of the table, its length and a pointer to the byte array are captured in struct vdso_image. Alternatively, the table could be dumped directly into the struct, but because the number of entries can vary per image, that would require either hardcoding a max sized table into the struct definition or defining the table as a flexible length array. The flexible length array approach has zero benefits, e.g. the base/size are still needed, and prevents reusing the extraction code, while hardcoding the max size adds ongoing maintenance just to avoid exporting the explicit size. The immediate use case is for Intel Software Guard Extensions (SGX). SGX introduces a new CPL3-only "enclave" mode that runs as a sort of black box shared object that is hosted by an untrusted "normal" CPl3 process. Entering an enclave can only be done through SGX-specific instructions, EENTER and ERESUME, and is a non-trivial process. Because of the complexity of transitioning to/from an enclave, the vast majority of enclaves are expected to utilize a library to handle the actual transitions. This is roughly analogous to how e.g. libc implementations are used by most applications. Another crucial characteristic of SGX enclaves is that they can generate exceptions as part of their normal (at least as "normal" as SGX can be) operation that need to be handled *in* the enclave and/or are unique to SGX. And because they are essentially fancy shared objects, a process can host any number of enclaves, each of which can execute multiple threads simultaneously. Putting everything together, userspace enclaves will utilize a library that must be prepared to handle any and (almost) all exceptions any time at least one thread may be executing in an enclave. Leveraging signals to handle the enclave exceptions is unpleasant, to put it mildly, e.g. the SGX library must constantly (un)register its signal handler based on whether or not at least one thread is executing in an enclave, and filter and forward exceptions that aren't related to its enclaves. This becomes particularly nasty when using multiple levels of libraries that register signal handlers, e.g. running an enclave via cgo inside of the Go runtime. Enabling exception fixup in vDSO allows the kernel to provide a vDSO function that wraps the low-level transitions to/from the enclave, i.e. the EENTER and ERESUME instructions. The vDSO function can intercept exceptions that would otherwise generate a signal and return the fault information directly to its caller, thus avoiding the need to juggle signal handlers. Note that unlike the kernel's _ASM_EXTABLE_HANDLE implementation, the 'C' version of _ASM_VDSO_EXTABLE_HANDLE doesn't use a pre-compiled assembly macro. Duplicating four lines of code is simpler than adding the necessary infrastructure to generate pre-compiled assembly and the intended benefit of massaging GCC's inlining algorithm is unlikely to realized in the vDSO any time soon, if ever. Suggested-by: Andy Lutomirski Signed-off-by: Sean Christopherson Signed-off-by: Jarkko Sakkinen --- arch/x86/entry/vdso/Makefile | 6 +-- arch/x86/entry/vdso/extable.c | 46 +++++++++++++++++++++ arch/x86/entry/vdso/extable.h | 29 ++++++++++++++ arch/x86/entry/vdso/vdso-layout.lds.S | 9 ++++- arch/x86/entry/vdso/vdso2c.h | 58 +++++++++++++++++++++++---- arch/x86/include/asm/vdso.h | 5 +++ 6 files changed, 141 insertions(+), 12 deletions(-) create mode 100644 arch/x86/entry/vdso/extable.c create mode 100644 arch/x86/entry/vdso/extable.h diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile index 433a1259f61d..657e01d34d02 100644 --- a/arch/x86/entry/vdso/Makefile +++ b/arch/x86/entry/vdso/Makefile @@ -26,7 +26,7 @@ VDSO32-$(CONFIG_IA32_EMULATION) := y vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o # files to link into kernel -obj-y += vma.o +obj-y += vma.o extable.o OBJECT_FILES_NON_STANDARD_vma.o := n # vDSO images to build @@ -120,8 +120,8 @@ $(obj)/%-x32.o: $(obj)/%.o FORCE targets += vdsox32.lds $(vobjx32s-y) -$(obj)/%.so: OBJCOPYFLAGS := -S -$(obj)/%.so: $(obj)/%.so.dbg FORCE +$(obj)/%.so: OBJCOPYFLAGS := -S --remove-section __ex_table +$(obj)/%.so: $(obj)/%.so.dbg $(call if_changed,objcopy) $(obj)/vdsox32.so.dbg: $(obj)/vdsox32.lds $(vobjx32s) FORCE diff --git a/arch/x86/entry/vdso/extable.c b/arch/x86/entry/vdso/extable.c new file mode 100644 index 000000000000..afcf5b65beef --- /dev/null +++ b/arch/x86/entry/vdso/extable.c @@ -0,0 +1,46 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include + +struct vdso_exception_table_entry { + int insn, fixup; +}; + +bool fixup_vdso_exception(struct pt_regs *regs, int trapnr, + unsigned long error_code, unsigned long fault_addr) +{ + const struct vdso_image *image = current->mm->context.vdso_image; + const struct vdso_exception_table_entry *extable; + unsigned int nr_entries, i; + unsigned long base; + + /* + * Do not attempt to fixup #DB or #BP. It's impossible to identify + * whether or not a #DB/#BP originated from within an SGX enclave and + * SGX enclaves are currently the only use case for vDSO fixup. + */ + if (trapnr == X86_TRAP_DB || trapnr == X86_TRAP_BP) + return false; + + if (!current->mm->context.vdso) + return false; + + base = (unsigned long)current->mm->context.vdso + image->extable_base; + nr_entries = image->extable_len / (sizeof(*extable)); + extable = image->extable; + + for (i = 0; i < nr_entries; i++) { + if (regs->ip == base + extable[i].insn) { + regs->ip = base + extable[i].fixup; + regs->di = trapnr; + regs->si = error_code; + regs->dx = fault_addr; + return true; + } + } + + return false; +} diff --git a/arch/x86/entry/vdso/extable.h b/arch/x86/entry/vdso/extable.h new file mode 100644 index 000000000000..aafdac396948 --- /dev/null +++ b/arch/x86/entry/vdso/extable.h @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __VDSO_EXTABLE_H +#define __VDSO_EXTABLE_H + +/* + * Inject exception fixup for vDSO code. Unlike normal exception fixup, + * vDSO uses a dedicated handler the addresses are relative to the overall + * exception table, not each individual entry. + */ +#ifdef __ASSEMBLY__ +#define _ASM_VDSO_EXTABLE_HANDLE(from, to) \ + ASM_VDSO_EXTABLE_HANDLE from to + +.macro ASM_VDSO_EXTABLE_HANDLE from:req to:req + .pushsection __ex_table, "a" + .long (\from) - __ex_table + .long (\to) - __ex_table + .popsection +.endm +#else +#define _ASM_VDSO_EXTABLE_HANDLE(from, to) \ + ".pushsection __ex_table, \"a\"\n" \ + ".long (" #from ") - __ex_table\n" \ + ".long (" #to ") - __ex_table\n" \ + ".popsection\n" +#endif + +#endif /* __VDSO_EXTABLE_H */ + diff --git a/arch/x86/entry/vdso/vdso-layout.lds.S b/arch/x86/entry/vdso/vdso-layout.lds.S index ea7e0155c604..e9994ee62fdd 100644 --- a/arch/x86/entry/vdso/vdso-layout.lds.S +++ b/arch/x86/entry/vdso/vdso-layout.lds.S @@ -68,11 +68,18 @@ SECTIONS * stuff that isn't used at runtime in between. */ - .text : { *(.text*) } :text =0x90909090, + .text : { + *(.text*) + *(.fixup) + } :text =0x90909090, + + .altinstructions : { *(.altinstructions) } :text .altinstr_replacement : { *(.altinstr_replacement) } :text + __ex_table : { *(__ex_table) } :text + /DISCARD/ : { *(.discard) *(.discard.*) diff --git a/arch/x86/entry/vdso/vdso2c.h b/arch/x86/entry/vdso/vdso2c.h index a20b134de2a8..04d04e46c98c 100644 --- a/arch/x86/entry/vdso/vdso2c.h +++ b/arch/x86/entry/vdso/vdso2c.h @@ -5,6 +5,41 @@ * are built for 32-bit userspace. */ +static void BITSFUNC(copy)(FILE *outfile, const unsigned char *data, size_t len) +{ + size_t i; + + for (i = 0; i < len; i++) { + if (i % 10 == 0) + fprintf(outfile, "\n\t"); + fprintf(outfile, "0x%02X, ", (int)(data)[i]); + } +} + + +/* + * Extract a section from the input data into a standalone blob. Used to + * capture kernel-only data that needs to persist indefinitely, e.g. the + * exception fixup tables, but only in the kernel, i.e. the section can + * be stripped from the final vDSO image. + */ +static void BITSFUNC(extract)(const unsigned char *data, size_t data_len, + FILE *outfile, ELF(Shdr) *sec, const char *name) +{ + unsigned long offset; + size_t len; + + offset = (unsigned long)GET_LE(&sec->sh_offset); + len = (size_t)GET_LE(&sec->sh_size); + + if (offset + len > data_len) + fail("section to extract overruns input data"); + + fprintf(outfile, "static const unsigned char %s[%lu] = {", name, len); + BITSFUNC(copy)(outfile, data + offset, len); + fprintf(outfile, "\n};\n\n"); +} + static void BITSFUNC(go)(void *raw_addr, size_t raw_len, void *stripped_addr, size_t stripped_len, FILE *outfile, const char *image_name) @@ -14,9 +49,8 @@ static void BITSFUNC(go)(void *raw_addr, size_t raw_len, unsigned long mapping_size; ELF(Ehdr) *hdr = (ELF(Ehdr) *)raw_addr; int i; - unsigned long j; ELF(Shdr) *symtab_hdr = NULL, *strtab_hdr, *secstrings_hdr, - *alt_sec = NULL; + *alt_sec = NULL, *extable_sec = NULL; ELF(Dyn) *dyn = 0, *dyn_end = 0; const char *secstrings; INT_BITS syms[NSYMS] = {}; @@ -78,6 +112,8 @@ static void BITSFUNC(go)(void *raw_addr, size_t raw_len, if (!strcmp(secstrings + GET_LE(&sh->sh_name), ".altinstructions")) alt_sec = sh; + if (!strcmp(secstrings + GET_LE(&sh->sh_name), "__ex_table")) + extable_sec = sh; } if (!symtab_hdr) @@ -150,13 +186,11 @@ static void BITSFUNC(go)(void *raw_addr, size_t raw_len, fprintf(outfile, "static unsigned char raw_data[%lu] __ro_after_init __aligned(PAGE_SIZE) = {", mapping_size); - for (j = 0; j < stripped_len; j++) { - if (j % 10 == 0) - fprintf(outfile, "\n\t"); - fprintf(outfile, "0x%02X, ", - (int)((unsigned char *)stripped_addr)[j]); - } + BITSFUNC(copy)(outfile, stripped_addr, stripped_len); fprintf(outfile, "\n};\n\n"); + if (extable_sec) + BITSFUNC(extract)(raw_addr, raw_len, outfile, + extable_sec, "extable"); fprintf(outfile, "const struct vdso_image %s = {\n", image_name); fprintf(outfile, "\t.data = raw_data,\n"); @@ -167,6 +201,14 @@ static void BITSFUNC(go)(void *raw_addr, size_t raw_len, fprintf(outfile, "\t.alt_len = %lu,\n", (unsigned long)GET_LE(&alt_sec->sh_size)); } + if (extable_sec) { + fprintf(outfile, "\t.extable_base = %lu,\n", + (unsigned long)GET_LE(&extable_sec->sh_offset)); + fprintf(outfile, "\t.extable_len = %lu,\n", + (unsigned long)GET_LE(&extable_sec->sh_size)); + fprintf(outfile, "\t.extable = extable,\n"); + } + for (i = 0; i < NSYMS; i++) { if (required_syms[i].export && syms[i]) fprintf(outfile, "\t.sym_%s = %" PRIi64 ",\n", diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h index bbcdc7b8f963..b5d23470f56b 100644 --- a/arch/x86/include/asm/vdso.h +++ b/arch/x86/include/asm/vdso.h @@ -15,6 +15,8 @@ struct vdso_image { unsigned long size; /* Always a multiple of PAGE_SIZE */ unsigned long alt, alt_len; + unsigned long extable_base, extable_len; + const void *extable; long sym_vvar_start; /* Negative offset to the vvar area */ @@ -45,6 +47,9 @@ extern void __init init_vdso_image(const struct vdso_image *image); extern int map_vdso_once(const struct vdso_image *image, unsigned long addr); +extern bool fixup_vdso_exception(struct pt_regs *regs, int trapnr, + unsigned long error_code, + unsigned long fault_addr); #endif /* __ASSEMBLER__ */ #endif /* _ASM_X86_VDSO_H */ From patchwork Tue Apr 21 21:53:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502367 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2F87C1575 for ; Tue, 21 Apr 2020 21:54:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 212F520724 for ; Tue, 21 Apr 2020 21:54:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726681AbgDUVy5 (ORCPT ); Tue, 21 Apr 2020 17:54:57 -0400 Received: from mga18.intel.com ([134.134.136.126]:11684 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726328AbgDUVy5 (ORCPT ); Tue, 21 Apr 2020 17:54:57 -0400 IronPort-SDR: 8iAQZYegnjZZRRTHn56CI5XL3i9j5U4wHmH0z9nXPOKULjD3nIboYRcXaqfkZc41pQMDa8jKDx nULcA2K4Z8Dg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:54:56 -0700 IronPort-SDR: +Ytifug0Cko3ABfHqixzgKVqE8Z6cjILTlxeuCnWXu6HF7xZQxu1morvMW6g1R2y0zrK5fgH2f CYjLdzB7hfXA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260810" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:54:51 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Jarkko Sakkinen Subject: [PATCH v29 16/20] x86/fault: Add helper function to sanitize error code Date: Wed, 22 Apr 2020 00:53:12 +0300 Message-Id: <20200421215316.56503-17-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org From: Sean Christopherson Add helper function to sanitize error code to prepare for vDSO exception fixup, which will expose the error code to userspace and runs before set_signal_archinfo(), i.e. suppresses the signal when fixup is successful. Signed-off-by: Sean Christopherson Signed-off-by: Jarkko Sakkinen --- arch/x86/mm/fault.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index dee9504cde79..6b662d272af6 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -682,6 +682,18 @@ pgtable_bad(struct pt_regs *regs, unsigned long error_code, oops_end(flags, regs, sig); } +static void sanitize_error_code(unsigned long address, + unsigned long *error_code) +{ + /* + * To avoid leaking information about the kernel page + * table layout, pretend that user-mode accesses to + * kernel addresses are always protection faults. + */ + if (address >= TASK_SIZE_MAX) + *error_code |= X86_PF_PROT; +} + static void set_signal_archinfo(unsigned long address, unsigned long error_code) { @@ -738,6 +750,8 @@ no_context(struct pt_regs *regs, unsigned long error_code, * faulting through the emulate_vsyscall() logic. */ if (current->thread.sig_on_uaccess_err && signal) { + sanitize_error_code(address, &error_code); + set_signal_archinfo(address, error_code); /* XXX: hwpoison faults will set the wrong code. */ @@ -886,13 +900,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code, if (is_errata100(regs, address)) return; - /* - * To avoid leaking information about the kernel page table - * layout, pretend that user-mode accesses to kernel addresses - * are always protection faults. - */ - if (address >= TASK_SIZE_MAX) - error_code |= X86_PF_PROT; + sanitize_error_code(address, &error_code); if (likely(show_unhandled_signals)) show_signal_msg(regs, error_code, address, tsk); @@ -1009,6 +1017,8 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address, if (is_prefetch(regs, error_code, address)) return; + sanitize_error_code(address, &error_code); + set_signal_archinfo(address, error_code); #ifdef CONFIG_MEMORY_FAILURE From patchwork Tue Apr 21 21:53:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502369 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 00EC01575 for ; Tue, 21 Apr 2020 21:55:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E762B206D9 for ; Tue, 21 Apr 2020 21:55:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726079AbgDUVzD (ORCPT ); Tue, 21 Apr 2020 17:55:03 -0400 Received: from mga09.intel.com ([134.134.136.24]:43154 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726055AbgDUVzD (ORCPT ); Tue, 21 Apr 2020 17:55:03 -0400 IronPort-SDR: 0mZX7F6+j+bfQs5JpBiv6gtBE9H88cm2L3j3FB35wHWWPRtkQtHxOUgzteENm2eUPW3x4FP1oy 42Q5tFQyY4xg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:55:02 -0700 IronPort-SDR: MWagytJ/9a37MlemrLusJVeg+mGW18aCCVsDtzEbMKfeEhKM6laI8Uq5k2KLwh/zTTP/n2mNXs nITXcGr6z6Fw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260846" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:54:57 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Andy Lutomirski , Jarkko Sakkinen Subject: [PATCH v29 17/20] x86/traps: Attempt to fixup exceptions in vDSO before signaling Date: Wed, 22 Apr 2020 00:53:13 +0300 Message-Id: <20200421215316.56503-18-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org From: Sean Christopherson vDSO functions can now leverage an exception fixup mechanism similar to kernel exception fixup. For vDSO exception fixup, the initial user is Intel's Software Guard Extensions (SGX), which will wrap the low-level transitions to/from the enclave, i.e. EENTER and ERESUME instructions, in a vDSO function and leverage fixup to intercept exceptions that would otherwise generate a signal. This allows the vDSO wrapper to return the fault information directly to its caller, obviating the need for SGX applications and libraries to juggle signal handlers. Attempt to fixup vDSO exceptions immediately prior to populating and sending signal information. Except for the delivery mechanism, an exception in a vDSO function should be treated like any other exception in userspace, e.g. any fault that is successfully handled by the kernel should not be directly visible to userspace. Although it's debatable whether or not all exceptions are of interest to enclaves, defer to the vDSO fixup to decide whether to do fixup or generate a signal. Future users of vDSO fixup, if there ever are any, will undoubtedly have different requirements than SGX enclaves, e.g. the fixup vs. signal logic can be made function specific if/when necessary. Suggested-by: Andy Lutomirski Signed-off-by: Sean Christopherson Signed-off-by: Jarkko Sakkinen --- arch/x86/kernel/traps.c | 14 ++++++++++++++ arch/x86/mm/fault.c | 8 ++++++++ 2 files changed, 22 insertions(+) diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 6ef00eb6fbb9..a814b1aea94d 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -56,6 +56,7 @@ #include #include #include +#include #ifdef CONFIG_X86_64 #include @@ -205,6 +206,9 @@ do_trap_no_signal(struct task_struct *tsk, int trapnr, const char *str, tsk->thread.error_code = error_code; tsk->thread.trap_nr = trapnr; die(str, regs, error_code); + } else { + if (fixup_vdso_exception(regs, trapnr, error_code, 0)) + return 0; } /* @@ -518,6 +522,9 @@ dotraplinkage void do_general_protection(struct pt_regs *regs, long error_code) tsk->thread.error_code = error_code; tsk->thread.trap_nr = X86_TRAP_GP; + if (fixup_vdso_exception(regs, X86_TRAP_GP, error_code, 0)) + return; + show_signal(tsk, SIGSEGV, "", desc, regs, error_code); force_sig(SIGSEGV); @@ -762,6 +769,10 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code) SIGTRAP) == NOTIFY_STOP) goto exit; + if (user_mode(regs) && + fixup_vdso_exception(regs, X86_TRAP_DB, error_code, 0)) + goto exit; + /* * Let others (NMI) know that the debug stack is in use * as we may switch to the interrupt stack. @@ -842,6 +853,9 @@ static void math_error(struct pt_regs *regs, int error_code, int trapnr) if (!si_code) return; + if (fixup_vdso_exception(regs, trapnr, error_code, 0)) + return; + force_sig_fault(SIGFPE, si_code, (void __user *)uprobe_get_trap_addr(regs)); } diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 6b662d272af6..42965b47b52f 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -30,6 +30,7 @@ #include /* store_idt(), ... */ #include /* exception stack */ #include /* VMALLOC_START, ... */ +#include /* fixup_vdso_exception() */ #define CREATE_TRACE_POINTS #include @@ -902,6 +903,10 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code, sanitize_error_code(address, &error_code); + if (fixup_vdso_exception(regs, X86_TRAP_PF, error_code, + address)) + return; + if (likely(show_unhandled_signals)) show_signal_msg(regs, error_code, address, tsk); @@ -1019,6 +1024,9 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address, sanitize_error_code(address, &error_code); + if (fixup_vdso_exception(regs, X86_TRAP_PF, error_code, address)) + return; + set_signal_archinfo(address, error_code); #ifdef CONFIG_MEMORY_FAILURE From patchwork Tue Apr 21 21:53:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502375 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 72B75913 for ; Tue, 21 Apr 2020 21:55:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 58C8E2072D for ; Tue, 21 Apr 2020 21:55:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726722AbgDUVz0 (ORCPT ); Tue, 21 Apr 2020 17:55:26 -0400 Received: from mga07.intel.com ([134.134.136.100]:58472 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725850AbgDUVzY (ORCPT ); Tue, 21 Apr 2020 17:55:24 -0400 IronPort-SDR: 79qs+yR/wtbIQFaWBH3Y3r6lSMd8kxocduq310YAMrPpgFVWALyHf8fe3GEirsVapXy00hSJ33 ZAZNNUIDP7MA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:55:08 -0700 IronPort-SDR: ecmFs9KYEMftMMh0z17qf4Uxfryxr3VRGPglpQMYV+OTfMp7Ws4ViDXGnHt+pk//iYuTpIziFk pk811pNitEeg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260894" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:55:03 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Andy Lutomirski , Jethro Beekman , Jarkko Sakkinen Subject: [PATCH v29 18/20] x86/vdso: Implement a vDSO for Intel SGX enclave call Date: Wed, 22 Apr 2020 00:53:14 +0300 Message-Id: <20200421215316.56503-19-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org From: Sean Christopherson An SGX runtime must be aware of the exceptions, which happen inside an enclave. Introduce a vDSO call that wraps EENTER/ERESUME cycle and returns the CPU exception back to the caller exactly when it happens. Kernel fixups the exception information to RDI, RSI and RDX. The SGX call vDSO handler fills this information to the user provided buffer or alternatively trigger user provided callback at the time of the exception. The calling convention is custom and does not follow System V x86-64 ABI. Suggested-by: Andy Lutomirski Signed-off-by: Sean Christopherson Co-developed-by: Cedric Xing Signed-off-by: Cedric Xing Tested-by: Jethro Beekman Signed-off-by: Jarkko Sakkinen --- arch/x86/entry/vdso/Makefile | 2 + arch/x86/entry/vdso/vdso.lds.S | 1 + arch/x86/entry/vdso/vsgx_enter_enclave.S | 131 +++++++++++++++++++++++ arch/x86/include/asm/enclu.h | 8 ++ arch/x86/include/uapi/asm/sgx.h | 98 +++++++++++++++++ 5 files changed, 240 insertions(+) create mode 100644 arch/x86/entry/vdso/vsgx_enter_enclave.S create mode 100644 arch/x86/include/asm/enclu.h diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile index 657e01d34d02..fa50c76a17a8 100644 --- a/arch/x86/entry/vdso/Makefile +++ b/arch/x86/entry/vdso/Makefile @@ -24,6 +24,7 @@ VDSO32-$(CONFIG_IA32_EMULATION) := y # files to link into the vdso vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o +vobjs-$(VDSO64-y) += vsgx_enter_enclave.o # files to link into kernel obj-y += vma.o extable.o @@ -90,6 +91,7 @@ $(vobjs): KBUILD_CFLAGS := $(filter-out $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS CFLAGS_REMOVE_vclock_gettime.o = -pg CFLAGS_REMOVE_vdso32/vclock_gettime.o = -pg CFLAGS_REMOVE_vgetcpu.o = -pg +CFLAGS_REMOVE_vsgx_enter_enclave.o = -pg # # X32 processes use x32 vDSO to access 64bit kernel data. diff --git a/arch/x86/entry/vdso/vdso.lds.S b/arch/x86/entry/vdso/vdso.lds.S index 36b644e16272..4bf48462fca7 100644 --- a/arch/x86/entry/vdso/vdso.lds.S +++ b/arch/x86/entry/vdso/vdso.lds.S @@ -27,6 +27,7 @@ VERSION { __vdso_time; clock_getres; __vdso_clock_getres; + __vdso_sgx_enter_enclave; local: *; }; } diff --git a/arch/x86/entry/vdso/vsgx_enter_enclave.S b/arch/x86/entry/vdso/vsgx_enter_enclave.S new file mode 100644 index 000000000000..be7e467e1efb --- /dev/null +++ b/arch/x86/entry/vdso/vsgx_enter_enclave.S @@ -0,0 +1,131 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#include +#include +#include +#include + +#include "extable.h" + +#define EX_LEAF 0*8 +#define EX_TRAPNR 0*8+4 +#define EX_ERROR_CODE 0*8+6 +#define EX_ADDRESS 1*8 + +.code64 +.section .text, "ax" + +SYM_FUNC_START(__vdso_sgx_enter_enclave) + /* Prolog */ + .cfi_startproc + push %rbp + .cfi_adjust_cfa_offset 8 + .cfi_rel_offset %rbp, 0 + mov %rsp, %rbp + .cfi_def_cfa_register %rbp + push %rbx + .cfi_rel_offset %rbx, -8 + + mov %ecx, %eax +.Lenter_enclave: + /* EENTER <= leaf <= ERESUME */ + cmp $EENTER, %eax + jb .Linvalid_leaf + cmp $ERESUME, %eax + ja .Linvalid_leaf + + /* Load TCS and AEP */ + mov 0x10(%rbp), %rbx + lea .Lasync_exit_pointer(%rip), %rcx + + /* Single ENCLU serving as both EENTER and AEP (ERESUME) */ +.Lasync_exit_pointer: +.Lenclu_eenter_eresume: + enclu + + /* EEXIT jumps here unless the enclave is doing something fancy. */ + xor %eax, %eax + + /* Invoke userspace's exit handler if one was provided. */ +.Lhandle_exit: + cmp $0, 0x20(%rbp) + jne .Linvoke_userspace_handler + +.Lout: + pop %rbx + leave + .cfi_def_cfa %rsp, 8 + ret + + /* The out-of-line code runs with the pre-leave stack frame. */ + .cfi_def_cfa %rbp, 16 + +.Linvalid_leaf: + mov $(-EINVAL), %eax + jmp .Lout + +.Lhandle_exception: + mov 0x18(%rbp), %rcx + test %rcx, %rcx + je .Lskip_exception_info + + /* Fill optional exception info. */ + mov %eax, EX_LEAF(%rcx) + mov %di, EX_TRAPNR(%rcx) + mov %si, EX_ERROR_CODE(%rcx) + mov %rdx, EX_ADDRESS(%rcx) +.Lskip_exception_info: + mov $(-EFAULT), %eax + jmp .Lhandle_exit + +.Linvoke_userspace_handler: + /* Pass the untrusted RSP (at exit) to the callback via %rcx. */ + mov %rsp, %rcx + + /* Save the untrusted RSP offset in %rbx (non-volatile register). */ + mov %rsp, %rbx + and $0xf, %rbx + + /* + * Align stack per x86_64 ABI. Note, %rsp needs to be 16-byte aligned + * _after_ pushing the parameters on the stack, hence the bonus push. + */ + and $-0x10, %rsp + push %rax + + /* Push @e, the "return" value and @tcs as params to the callback. */ + push 0x18(%rbp) + push %rax + push 0x10(%rbp) + + /* Clear RFLAGS.DF per x86_64 ABI */ + cld + + /* Load the callback pointer to %rax and invoke it via retpoline. */ + mov 0x20(%rbp), %rax + call .Lretpoline + + /* Undo the post-exit %rsp adjustment. */ + lea 0x20(%rsp, %rbx), %rsp + + /* + * If the return from callback is zero or negative, return immediately, + * else re-execute ENCLU with the postive return value interpreted as + * the requested ENCLU leaf. + */ + cmp $0, %eax + jle .Lout + jmp .Lenter_enclave + +.Lretpoline: + call 2f +1: pause + lfence + jmp 1b +2: mov %rax, (%rsp) + ret + .cfi_endproc + +_ASM_VDSO_EXTABLE_HANDLE(.Lenclu_eenter_eresume, .Lhandle_exception) + +SYM_FUNC_END(__vdso_sgx_enter_enclave) diff --git a/arch/x86/include/asm/enclu.h b/arch/x86/include/asm/enclu.h new file mode 100644 index 000000000000..06157b3e9ede --- /dev/null +++ b/arch/x86/include/asm/enclu.h @@ -0,0 +1,8 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_ENCLU_H +#define _ASM_X86_ENCLU_H + +#define EENTER 0x02 +#define ERESUME 0x03 + +#endif /* _ASM_X86_ENCLU_H */ diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h index 57d0d30c79b3..3760e5d5dc0c 100644 --- a/arch/x86/include/uapi/asm/sgx.h +++ b/arch/x86/include/uapi/asm/sgx.h @@ -74,4 +74,102 @@ struct sgx_enclave_set_attribute { __u64 attribute_fd; }; +/** + * struct sgx_enclave_exception - structure to report exceptions encountered in + * __vdso_sgx_enter_enclave() + * + * @leaf: ENCLU leaf from \%eax at time of exception + * @trapnr: exception trap number, a.k.a. fault vector + * @error_code: exception error code + * @address: exception address, e.g. CR2 on a #PF + * @reserved: reserved for future use + */ +struct sgx_enclave_exception { + __u32 leaf; + __u16 trapnr; + __u16 error_code; + __u64 address; + __u64 reserved[2]; +}; + +/** + * typedef sgx_enclave_exit_handler_t - Exit handler function accepted by + * __vdso_sgx_enter_enclave() + * + * @rdi: RDI at the time of enclave exit + * @rsi: RSI at the time of enclave exit + * @rdx: RDX at the time of enclave exit + * @ursp: RSP at the time of enclave exit (untrusted stack) + * @r8: R8 at the time of enclave exit + * @r9: R9 at the time of enclave exit + * @tcs: Thread Control Structure used to enter enclave + * @ret: 0 on success (EEXIT), -EFAULT on an exception + * @e: Pointer to struct sgx_enclave_exception (as provided by caller) + */ +typedef int (*sgx_enclave_exit_handler_t)(long rdi, long rsi, long rdx, + long ursp, long r8, long r9, + void *tcs, int ret, + struct sgx_enclave_exception *e); + +/** + * __vdso_sgx_enter_enclave() - Enter an SGX enclave + * @rdi: Pass-through value for RDI + * @rsi: Pass-through value for RSI + * @rdx: Pass-through value for RDX + * @leaf: ENCLU leaf, must be EENTER or ERESUME + * @r8: Pass-through value for R8 + * @r9: Pass-through value for R9 + * @tcs: TCS, must be non-NULL + * @e: Optional struct sgx_enclave_exception instance + * @handler: Optional enclave exit handler + * + * NOTE: __vdso_sgx_enter_enclave() does not ensure full compliance with the + * x86-64 ABI, e.g. doesn't explicitly clear EFLAGS.DF after EEXIT. Except for + * non-volatile general purpose registers, preserving/setting state in + * accordance with the x86-64 ABI is the responsibility of the enclave and its + * runtime, i.e. __vdso_sgx_enter_enclave() cannot be called from C code + * without careful consideration by both the enclave and its runtime. + * + * All general purpose registers except RAX, RBX and RCX are passed as-is to + * the enclave. RAX, RBX and RCX are consumed by EENTER and ERESUME and are + * loaded with @leaf, asynchronous exit pointer, and @tcs respectively. + * + * RBP and the stack are used to anchor __vdso_sgx_enter_enclave() to the + * pre-enclave state, e.g. to retrieve @e and @handler after an enclave exit. + * All other registers are available for use by the enclave and its runtime, + * e.g. an enclave can push additional data onto the stack (and modify RSP) to + * pass information to the optional exit handler (see below). + * + * Most exceptions reported on ENCLU, including those that occur within the + * enclave, are fixed up and reported synchronously instead of being delivered + * via a standard signal. Debug Exceptions (#DB) and Breakpoints (#BP) are + * never fixed up and are always delivered via standard signals. On synchrously + * reported exceptions, -EFAULT is returned and details about the exception are + * recorded in @e, the optional sgx_enclave_exception struct. + + * If an exit handler is provided, the handler will be invoked on synchronous + * exits from the enclave and for all synchronously reported exceptions. In + * latter case, @e is filled prior to invoking the handler. + * + * The exit handler's return value is interpreted as follows: + * >0: continue, restart __vdso_sgx_enter_enclave() with @ret as @leaf + * 0: success, return @ret to the caller + * <0: error, return @ret to the caller + * + * The exit handler may transfer control, e.g. via longjmp() or C++ exception, + * without returning to __vdso_sgx_enter_enclave(). + * + * Return: + * 0 on success, + * -EINVAL if ENCLU leaf is not allowed, + * -EFAULT if an exception occurs on ENCLU or within the enclave + * -errno for all other negative values returned by the userspace exit handler + */ +typedef int (*vdso_sgx_enter_enclave_t)(unsigned long rdi, unsigned long rsi, + unsigned long rdx, unsigned int leaf, + unsigned long r8, unsigned long r9, + void *tcs, + struct sgx_enclave_exception *e, + sgx_enclave_exit_handler_t handler); + #endif /* _UAPI_ASM_X86_SGX_H */ From patchwork Tue Apr 21 21:53:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502371 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2606A913 for ; Tue, 21 Apr 2020 21:55:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 013B82072D for ; Tue, 21 Apr 2020 21:55:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726383AbgDUVzT (ORCPT ); Tue, 21 Apr 2020 17:55:19 -0400 Received: from mga03.intel.com ([134.134.136.65]:27185 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726055AbgDUVzS (ORCPT ); Tue, 21 Apr 2020 17:55:18 -0400 IronPort-SDR: qD9HrtsO/Fe0hE5RqROLD8xpwlv6seGxFDbpqvV1q0BzjlZ/JZfnHyfjOnEWpros8GzW/u6efI rFYKyjyT1p5Q== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:55:15 -0700 IronPort-SDR: bA0sHzwtEuVpRrdzQTcpJ4Z8UwoZ/ySDVRbUnKL148DmbKRnYvHzxxd+Z8NM0OhvbmOz5bsNe3 t5hSSbIf32sQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260913" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:55:09 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Jarkko Sakkinen , linux-kselftest@vger.kernel.org Subject: [PATCH v29 19/20] selftests/x86: Add a selftest for SGX Date: Wed, 22 Apr 2020 00:53:15 +0300 Message-Id: <20200421215316.56503-20-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org Add a selftest for SGX. It is a trivial test where a simple enclave copies one 64-bit word of memory between two memory locations. Cc: linux-kselftest@vger.kernel.org Signed-off-by: Jarkko Sakkinen --- tools/testing/selftests/Makefile | 1 + tools/testing/selftests/sgx/.gitignore | 2 + tools/testing/selftests/sgx/Makefile | 53 +++ tools/testing/selftests/sgx/call.S | 54 +++ tools/testing/selftests/sgx/defines.h | 21 + tools/testing/selftests/sgx/load.c | 282 +++++++++++++ tools/testing/selftests/sgx/main.c | 199 +++++++++ tools/testing/selftests/sgx/main.h | 38 ++ tools/testing/selftests/sgx/sigstruct.c | 395 ++++++++++++++++++ tools/testing/selftests/sgx/test_encl.c | 20 + tools/testing/selftests/sgx/test_encl.lds | 40 ++ .../selftests/sgx/test_encl_bootstrap.S | 89 ++++ 12 files changed, 1194 insertions(+) create mode 100644 tools/testing/selftests/sgx/.gitignore create mode 100644 tools/testing/selftests/sgx/Makefile create mode 100644 tools/testing/selftests/sgx/call.S create mode 100644 tools/testing/selftests/sgx/defines.h create mode 100644 tools/testing/selftests/sgx/load.c create mode 100644 tools/testing/selftests/sgx/main.c create mode 100644 tools/testing/selftests/sgx/main.h create mode 100644 tools/testing/selftests/sgx/sigstruct.c create mode 100644 tools/testing/selftests/sgx/test_encl.c create mode 100644 tools/testing/selftests/sgx/test_encl.lds create mode 100644 tools/testing/selftests/sgx/test_encl_bootstrap.S diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 6ec503912bea..183a050b5bda 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -63,6 +63,7 @@ TARGETS += user TARGETS += vm TARGETS += x86 TARGETS += zram +TARGETS += sgx #Please keep the TARGETS list alphabetically sorted # Run "make quicktest=1 run_tests" or # "make quicktest=1 kselftest" from top level Makefile diff --git a/tools/testing/selftests/sgx/.gitignore b/tools/testing/selftests/sgx/.gitignore new file mode 100644 index 000000000000..fbaf0bda9a92 --- /dev/null +++ b/tools/testing/selftests/sgx/.gitignore @@ -0,0 +1,2 @@ +test_sgx +test_encl.elf diff --git a/tools/testing/selftests/sgx/Makefile b/tools/testing/selftests/sgx/Makefile new file mode 100644 index 000000000000..95e5c4df8014 --- /dev/null +++ b/tools/testing/selftests/sgx/Makefile @@ -0,0 +1,53 @@ +top_srcdir = ../../../.. + +include ../lib.mk + +.PHONY: all clean + +CAN_BUILD_X86_64 := $(shell ../x86/check_cc.sh $(CC) \ + ../x86/trivial_64bit_program.c) + +ifndef OBJCOPY +OBJCOPY := $(CROSS_COMPILE)objcopy +endif + +INCLUDES := -I$(top_srcdir)/tools/include +HOST_CFLAGS := -Wall -Werror -g $(INCLUDES) -fPIC -z noexecstack +ENCL_CFLAGS := -Wall -Werror -static -nostdlib -nostartfiles -fPIC \ + -fno-stack-protector -mrdrnd $(INCLUDES) + +TEST_CUSTOM_PROGS := $(OUTPUT)/test_sgx $(OUTPUT)/test_encl.elf + +ifeq ($(CAN_BUILD_X86_64), 1) +all: $(TEST_CUSTOM_PROGS) +endif + +$(OUTPUT)/test_sgx: $(OUTPUT)/main.o \ + $(OUTPUT)/load.o \ + $(OUTPUT)/sigstruct.o \ + $(OUTPUT)/call.o + $(CC) $(HOST_CFLAGS) -o $@ $^ -lcrypto + +$(OUTPUT)/main.o: main.c + $(CC) $(HOST_CFLAGS) -c $< -o $@ + +$(OUTPUT)/load.o: load.c + $(CC) $(HOST_CFLAGS) -c $< -o $@ + +$(OUTPUT)/sigstruct.o: sigstruct.c + $(CC) $(HOST_CFLAGS) -c $< -o $@ + +$(OUTPUT)/call.o: call.S + $(CC) $(HOST_CFLAGS) -c $< -o $@ + +$(OUTPUT)/test_encl.elf: test_encl.lds test_encl.c test_encl_bootstrap.S + $(CC) $(ENCL_CFLAGS) -T $^ -o $@ + +EXTRA_CLEAN := \ + $(OUTPUT)/test_encl.elf \ + $(OUTPUT)/load.o \ + $(OUTPUT)/call.o \ + $(OUTPUT)/main.o \ + $(OUTPUT)/sigstruct.o \ + $(OUTPUT)/test_sgx \ + $(OUTPUT)/test_sgx.o \ diff --git a/tools/testing/selftests/sgx/call.S b/tools/testing/selftests/sgx/call.S new file mode 100644 index 000000000000..77131e83db42 --- /dev/null +++ b/tools/testing/selftests/sgx/call.S @@ -0,0 +1,54 @@ +/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */ +/** +* Copyright(c) 2016-18 Intel Corporation. +*/ + + .text + + .macro ENCLU + .byte 0x0f, 0x01, 0xd7 + .endm + + .text + + .global sgx_call_vdso +sgx_call_vdso: + .cfi_startproc + push %r15 + .cfi_adjust_cfa_offset 8 + .cfi_rel_offset %r15, 0 + push %r14 + .cfi_adjust_cfa_offset 8 + .cfi_rel_offset %r14, 0 + push %r13 + .cfi_adjust_cfa_offset 8 + .cfi_rel_offset %r13, 0 + push %r12 + .cfi_adjust_cfa_offset 8 + .cfi_rel_offset %r12, 0 + push %rbx + .cfi_adjust_cfa_offset 8 + .cfi_rel_offset %rbx, 0 + push $0 + .cfi_adjust_cfa_offset 8 + push 0x48(%rsp) + .cfi_adjust_cfa_offset 8 + push 0x48(%rsp) + .cfi_adjust_cfa_offset 8 + push 0x48(%rsp) + .cfi_adjust_cfa_offset 8 + call *eenter(%rip) + add $0x20, %rsp + .cfi_adjust_cfa_offset -0x20 + pop %rbx + .cfi_adjust_cfa_offset -8 + pop %r12 + .cfi_adjust_cfa_offset -8 + pop %r13 + .cfi_adjust_cfa_offset -8 + pop %r14 + .cfi_adjust_cfa_offset -8 + pop %r15 + .cfi_adjust_cfa_offset -8 + ret + .cfi_endproc diff --git a/tools/testing/selftests/sgx/defines.h b/tools/testing/selftests/sgx/defines.h new file mode 100644 index 000000000000..be8969922804 --- /dev/null +++ b/tools/testing/selftests/sgx/defines.h @@ -0,0 +1,21 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright(c) 2016-19 Intel Corporation. + */ + +#ifndef DEFINES_H +#define DEFINES_H + +#include + +#define PAGE_SIZE 4096 +#define PAGE_MASK (~(PAGE_SIZE - 1)) + +#define __aligned(x) __attribute__((__aligned__(x))) +#define __packed __attribute__((packed)) + +#include "../../../../arch/x86/kernel/cpu/sgx/arch.h" +#include "../../../../arch/x86/include/asm/enclu.h" +#include "../../../../arch/x86/include/uapi/asm/sgx.h" + +#endif /* DEFINES_H */ diff --git a/tools/testing/selftests/sgx/load.c b/tools/testing/selftests/sgx/load.c new file mode 100644 index 000000000000..53c565347e9e --- /dev/null +++ b/tools/testing/selftests/sgx/load.c @@ -0,0 +1,282 @@ +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) +// Copyright(c) 2016-18 Intel Corporation. + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "defines.h" +#include "main.h" + +void encl_delete(struct encl *encl) +{ + if (encl->encl_base) + munmap((void *)encl->encl_base, encl->encl_size); + + if (encl->bin) + munmap(encl->bin, encl->bin_size); + + if (encl->fd) + close(encl->fd); + + if (encl->segment_tbl) + free(encl->segment_tbl); + + memset(encl, 0, sizeof(*encl)); +} + +static bool encl_map_bin(const char *path, struct encl *encl) +{ + struct stat sb; + void *bin; + int ret; + int fd; + + fd = open(path, O_RDONLY); + if (fd == -1) { + perror("open()"); + return false; + } + + ret = stat(path, &sb); + if (ret) { + perror("stat()"); + goto err; + } + + bin = mmap(NULL, sb.st_size, PROT_READ, MAP_PRIVATE, fd, 0); + if (bin == MAP_FAILED) { + perror("mmap()"); + goto err; + } + + encl->bin = bin; + encl->bin_size = sb.st_size; + + close(fd); + return true; + +err: + close(fd); + return false; +} + +static bool encl_ioc_create(struct encl *encl) +{ + struct sgx_secs *secs = &encl->secs; + struct sgx_enclave_create ioc; + int rc; + + assert(encl->encl_base != 0); + + memset(secs, 0, sizeof(*secs)); + secs->ssa_frame_size = 1; + secs->attributes = SGX_ATTR_MODE64BIT; + secs->xfrm = 3; + secs->base = encl->encl_base; + secs->size = encl->encl_size; + + ioc.src = (unsigned long)secs; + rc = ioctl(encl->fd, SGX_IOC_ENCLAVE_CREATE, &ioc); + if (rc) { + fprintf(stderr, "SGX_IOC_ENCLAVE_CREATE failed: errno=%d\n", + errno); + munmap((void *)secs->base, encl->encl_size); + return false; + } + + return true; +} + +static bool encl_ioc_add_pages(struct encl *encl, struct encl_segment *seg) +{ + struct sgx_enclave_add_pages ioc; + struct sgx_secinfo secinfo; + int rc; + + memset(&secinfo, 0, sizeof(secinfo)); + secinfo.flags = seg->flags; + + ioc.src = (uint64_t)encl->src + seg->offset; + ioc.offset = seg->offset; + ioc.length = seg->size; + ioc.secinfo = (unsigned long)&secinfo; + ioc.flags = SGX_PAGE_MEASURE; + + rc = ioctl(encl->fd, SGX_IOC_ENCLAVE_ADD_PAGES, &ioc); + if (rc) { + fprintf(stderr, "SGX_IOC_ENCLAVE_ADD_PAGES failed: errno=%d.\n", + errno); + return false; + } + + if (ioc.count != ioc.length) { + fprintf(stderr, "A segment not fully processed.\n"); + return false; + } + + return true; +} + +bool encl_load(const char *path, struct encl *encl) +{ + Elf64_Phdr *phdr_tbl; + off_t src_offset; + Elf64_Ehdr *ehdr; + int i, j; + int ret; + + memset(encl, 0, sizeof(*encl)); + + ret = open("/dev/sgx/enclave", O_RDWR); + if (ret < 0) { + fprintf(stderr, "Unable to open /dev/sgx\n"); + goto err; + } + + encl->fd = ret; + + if (!encl_map_bin(path, encl)) + goto err; + + ehdr = encl->bin; + phdr_tbl = encl->bin + ehdr->e_phoff; + + for (i = 0; i < ehdr->e_phnum; i++) { + Elf64_Phdr *phdr = &phdr_tbl[i]; + + if (phdr->p_type == PT_LOAD) + encl->nr_segments++; + } + + encl->segment_tbl = calloc(encl->nr_segments, + sizeof(struct encl_segment)); + if (!encl->segment_tbl) + goto err; + + for (i = 0, j = 0; i < ehdr->e_phnum; i++) { + Elf64_Phdr *phdr = &phdr_tbl[i]; + unsigned int flags = phdr->p_flags; + struct encl_segment *seg; + + if (phdr->p_type != PT_LOAD) + continue; + + seg = &encl->segment_tbl[j]; + + if (!!(flags & ~(PF_R | PF_W | PF_X))) { + fprintf(stderr, + "%d has invalid segment flags 0x%02x.\n", i, + phdr->p_flags); + goto err; + } + + if (j == 0 && flags != (PF_R | PF_W)) { + fprintf(stderr, + "TCS has invalid segment flags 0x%02x.\n", + phdr->p_flags); + goto err; + } + + if (j == 0) { + src_offset = (phdr->p_offset & PAGE_MASK) - src_offset; + + seg->prot = PROT_READ | PROT_WRITE; + seg->flags = SGX_PAGE_TYPE_TCS << 8; + } else { + seg->prot = (phdr->p_flags & PF_R) ? PROT_READ : 0; + seg->prot |= (phdr->p_flags & PF_W) ? PROT_WRITE : 0; + seg->prot |= (phdr->p_flags & PF_X) ? PROT_EXEC : 0; + seg->flags = (SGX_PAGE_TYPE_REG << 8) | seg->prot; + } + + seg->offset = (phdr->p_offset & PAGE_MASK) - src_offset; + seg->size = (phdr->p_filesz + PAGE_SIZE - 1) & PAGE_MASK; + + printf("0x%016lx 0x%016lx 0x%02x\n", seg->offset, seg->size, + seg->prot); + + j++; + } + + assert(j == encl->nr_segments); + + encl->src = encl->bin + src_offset; + encl->src_size = encl->segment_tbl[j - 1].offset + + encl->segment_tbl[j - 1].size; + + for (encl->encl_size = 4096; encl->encl_size < encl->src_size; ) + encl->encl_size <<= 1; + + return true; + +err: + encl_delete(encl); + return false; +} + +static bool encl_map_area(struct encl *encl) +{ + size_t encl_size = encl->encl_size; + void *area; + + area = mmap(NULL, encl_size * 2, PROT_NONE, + MAP_SHARED | MAP_ANONYMOUS, -1, 0); + if (area == MAP_FAILED) { + perror("mmap"); + return false; + } + + encl->encl_base = ((uint64_t)area + encl_size - 1) & ~(encl_size - 1); + + munmap(area, encl->encl_base - (uint64_t)area); + munmap((void *)(encl->encl_base + encl_size), + (uint64_t)area + encl_size - encl->encl_base); + + return true; +} + +bool encl_build(struct encl *encl) +{ + struct sgx_enclave_init ioc; + int ret; + int i; + + if (!encl_map_area(encl)) + return false; + + if (!encl_ioc_create(encl)) + return false; + + /* + * Pages must be added before mapping VMAs because their permissions + * cap the VMA permissions. + */ + for (i = 0; i < encl->nr_segments; i++) { + struct encl_segment *seg = &encl->segment_tbl[i]; + + if (!encl_ioc_add_pages(encl, seg)) + return false; + } + + ioc.sigstruct = (uint64_t)&encl->sigstruct; + ret = ioctl(encl->fd, SGX_IOC_ENCLAVE_INIT, &ioc); + if (ret) { + fprintf(stderr, "SGX_IOC_ENCLAVE_INIT failed: errno=%d\n", + errno); + return false; + } + + return true; +} diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c new file mode 100644 index 000000000000..5394b2f6af8e --- /dev/null +++ b/tools/testing/selftests/sgx/main.c @@ -0,0 +1,199 @@ +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) +// Copyright(c) 2016-18 Intel Corporation. + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "defines.h" +#include "main.h" + +static const uint64_t MAGIC = 0x1122334455667788ULL; +vdso_sgx_enter_enclave_t eenter; + +struct vdso_symtab { + Elf64_Sym *elf_symtab; + const char *elf_symstrtab; + Elf64_Word *elf_hashtab; +}; + +static void *vdso_get_base_addr(char *envp[]) +{ + Elf64_auxv_t *auxv; + int i; + + for (i = 0; envp[i]; i++) + ; + + auxv = (Elf64_auxv_t *)&envp[i + 1]; + + for (i = 0; auxv[i].a_type != AT_NULL; i++) { + if (auxv[i].a_type == AT_SYSINFO_EHDR) + return (void *)auxv[i].a_un.a_val; + } + + return NULL; +} + +static Elf64_Dyn *vdso_get_dyntab(void *addr) +{ + Elf64_Ehdr *ehdr = addr; + Elf64_Phdr *phdrtab = addr + ehdr->e_phoff; + int i; + + for (i = 0; i < ehdr->e_phnum; i++) + if (phdrtab[i].p_type == PT_DYNAMIC) + return addr + phdrtab[i].p_offset; + + return NULL; +} + +static void *vdso_get_dyn(void *addr, Elf64_Dyn *dyntab, Elf64_Sxword tag) +{ + int i; + + for (i = 0; dyntab[i].d_tag != DT_NULL; i++) + if (dyntab[i].d_tag == tag) + return addr + dyntab[i].d_un.d_ptr; + + return NULL; +} + +static bool vdso_get_symtab(void *addr, struct vdso_symtab *symtab) +{ + Elf64_Dyn *dyntab = vdso_get_dyntab(addr); + + symtab->elf_symtab = vdso_get_dyn(addr, dyntab, DT_SYMTAB); + if (!symtab->elf_symtab) + return false; + + symtab->elf_symstrtab = vdso_get_dyn(addr, dyntab, DT_STRTAB); + if (!symtab->elf_symstrtab) + return false; + + symtab->elf_hashtab = vdso_get_dyn(addr, dyntab, DT_HASH); + if (!symtab->elf_hashtab) + return false; + + return true; +} + +static unsigned long elf_sym_hash(const char *name) +{ + unsigned long h = 0, high; + + while (*name) { + h = (h << 4) + *name++; + high = h & 0xf0000000; + + if (high) + h ^= high >> 24; + + h &= ~high; + } + + return h; +} + +static Elf64_Sym *vdso_symtab_get(struct vdso_symtab *symtab, const char *name) +{ + Elf64_Word bucketnum = symtab->elf_hashtab[0]; + Elf64_Word *buckettab = &symtab->elf_hashtab[2]; + Elf64_Word *chaintab = &symtab->elf_hashtab[2 + bucketnum]; + Elf64_Sym *sym; + Elf64_Word i; + + for (i = buckettab[elf_sym_hash(name) % bucketnum]; i != STN_UNDEF; + i = chaintab[i]) { + sym = &symtab->elf_symtab[i]; + if (!strcmp(name, &symtab->elf_symstrtab[sym->st_name])) + return sym; + } + + return NULL; +} + +int main(int argc, char *argv[], char *envp[]) +{ + struct sgx_enclave_exception exception; + struct vdso_symtab symtab; + Elf64_Sym *eenter_sym; + uint64_t result = 0; + struct encl encl; + unsigned int i; + void *addr; + + if (!encl_load("test_encl.elf", &encl)) + goto err; + + if (!encl_measure(&encl)) + goto err; + + if (!encl_build(&encl)) + goto err; + + /* + * An enclave consumer only must do this. + */ + for (i = 0; i < encl.nr_segments; i++) { + struct encl_segment *seg = &encl.segment_tbl[i]; + + addr = mmap((void *)encl.encl_base + seg->offset, seg->size, + seg->prot, MAP_SHARED | MAP_FIXED, encl.fd, 0); + if (addr == MAP_FAILED) { + fprintf(stderr, "mmap() failed, errno=%d.\n", errno); + return false; + } + } + + memset(&exception, 0, sizeof(exception)); + + addr = vdso_get_base_addr(envp); + if (!addr) + goto err; + + if (!vdso_get_symtab(addr, &symtab)) + goto err; + + eenter_sym = vdso_symtab_get(&symtab, "__vdso_sgx_enter_enclave"); + if (!eenter_sym) + goto err; + + eenter = addr + eenter_sym->st_value; + + sgx_call_vdso((void *)&MAGIC, &result, 0, EENTER, NULL, NULL, + (void *)encl.encl_base, &exception, NULL); + if (result != MAGIC) { + printf("FAIL: sgx_call_vdso(), expected: 0x%lx, got: 0x%lx\n", + MAGIC, result); + goto err; + } + + /* Invoke the vDSO directly. */ + result = 0; + eenter((unsigned long)&MAGIC, (unsigned long)&result, 0, EENTER, 0, 0, + (void *)encl.encl_base, &exception, NULL); + if (result != MAGIC) { + printf("FAIL: eenter(), expected: 0x%lx, got: 0x%lx\n", + MAGIC, result); + goto err; + } + + printf("SUCCESS\n"); + encl_delete(&encl); + exit(0); + +err: + encl_delete(&encl); + exit(1); +} diff --git a/tools/testing/selftests/sgx/main.h b/tools/testing/selftests/sgx/main.h new file mode 100644 index 000000000000..999422cc7343 --- /dev/null +++ b/tools/testing/selftests/sgx/main.h @@ -0,0 +1,38 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright(c) 2016-19 Intel Corporation. + */ + +#ifndef MAIN_H +#define MAIN_H + +struct encl_segment { + off_t offset; + size_t size; + unsigned int prot; + unsigned int flags; +}; + +struct encl { + int fd; + void *bin; + off_t bin_size; + void *src; + size_t src_size; + size_t encl_size; + off_t encl_base; + unsigned int nr_segments; + struct encl_segment *segment_tbl; + struct sgx_secs secs; + struct sgx_sigstruct sigstruct; +}; + +void encl_delete(struct encl *ctx); +bool encl_load(const char *path, struct encl *encl); +bool encl_measure(struct encl *encl); +bool encl_build(struct encl *encl); + +int sgx_call_vdso(void *rdi, void *rsi, long rdx, u32 leaf, void *r8, void *r9, + void *tcs, struct sgx_enclave_exception *ei, void *cb); + +#endif /* MAIN_H */ diff --git a/tools/testing/selftests/sgx/sigstruct.c b/tools/testing/selftests/sgx/sigstruct.c new file mode 100644 index 000000000000..ceddad478672 --- /dev/null +++ b/tools/testing/selftests/sgx/sigstruct.c @@ -0,0 +1,395 @@ +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) +// Copyright(c) 2016-18 Intel Corporation. + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "defines.h" +#include "main.h" + +struct q1q2_ctx { + BN_CTX *bn_ctx; + BIGNUM *m; + BIGNUM *s; + BIGNUM *q1; + BIGNUM *qr; + BIGNUM *q2; +}; + +static void free_q1q2_ctx(struct q1q2_ctx *ctx) +{ + BN_CTX_free(ctx->bn_ctx); + BN_free(ctx->m); + BN_free(ctx->s); + BN_free(ctx->q1); + BN_free(ctx->qr); + BN_free(ctx->q2); +} + +static bool alloc_q1q2_ctx(const uint8_t *s, const uint8_t *m, + struct q1q2_ctx *ctx) +{ + ctx->bn_ctx = BN_CTX_new(); + ctx->s = BN_bin2bn(s, SGX_MODULUS_SIZE, NULL); + ctx->m = BN_bin2bn(m, SGX_MODULUS_SIZE, NULL); + ctx->q1 = BN_new(); + ctx->qr = BN_new(); + ctx->q2 = BN_new(); + + if (!ctx->bn_ctx || !ctx->s || !ctx->m || !ctx->q1 || !ctx->qr || + !ctx->q2) { + free_q1q2_ctx(ctx); + return false; + } + + return true; +} + +static bool calc_q1q2(const uint8_t *s, const uint8_t *m, uint8_t *q1, + uint8_t *q2) +{ + struct q1q2_ctx ctx; + + if (!alloc_q1q2_ctx(s, m, &ctx)) { + fprintf(stderr, "Not enough memory for Q1Q2 calculation\n"); + return false; + } + + if (!BN_mul(ctx.q1, ctx.s, ctx.s, ctx.bn_ctx)) + goto out; + + if (!BN_div(ctx.q1, ctx.qr, ctx.q1, ctx.m, ctx.bn_ctx)) + goto out; + + if (BN_num_bytes(ctx.q1) > SGX_MODULUS_SIZE) { + fprintf(stderr, "Too large Q1 %d bytes\n", + BN_num_bytes(ctx.q1)); + goto out; + } + + if (!BN_mul(ctx.q2, ctx.s, ctx.qr, ctx.bn_ctx)) + goto out; + + if (!BN_div(ctx.q2, NULL, ctx.q2, ctx.m, ctx.bn_ctx)) + goto out; + + if (BN_num_bytes(ctx.q2) > SGX_MODULUS_SIZE) { + fprintf(stderr, "Too large Q2 %d bytes\n", + BN_num_bytes(ctx.q2)); + goto out; + } + + BN_bn2bin(ctx.q1, q1); + BN_bn2bin(ctx.q2, q2); + + free_q1q2_ctx(&ctx); + return true; +out: + free_q1q2_ctx(&ctx); + return false; +} + +struct sgx_sigstruct_payload { + struct sgx_sigstruct_header header; + struct sgx_sigstruct_body body; +}; + +static bool check_crypto_errors(void) +{ + int err; + bool had_errors = false; + const char *filename; + int line; + char str[256]; + + for ( ; ; ) { + if (ERR_peek_error() == 0) + break; + + had_errors = true; + err = ERR_get_error_line(&filename, &line); + ERR_error_string_n(err, str, sizeof(str)); + fprintf(stderr, "crypto: %s: %s:%d\n", str, filename, line); + } + + return had_errors; +} + +static inline const BIGNUM *get_modulus(RSA *key) +{ +#if OPENSSL_VERSION_NUMBER < 0x10100000L + return key->n; +#else + const BIGNUM *n; + + RSA_get0_key(key, &n, NULL, NULL); + return n; +#endif +} + +static RSA *gen_sign_key(void) +{ + BIGNUM *e; + RSA *key; + int ret; + + e = BN_new(); + key = RSA_new(); + + if (!e || !key) + goto err; + + ret = BN_set_word(e, RSA_3); + if (ret != 1) + goto err; + + ret = RSA_generate_key_ex(key, 3072, e, NULL); + if (ret != 1) + goto err; + + BN_free(e); + + return key; + +err: + RSA_free(key); + BN_free(e); + + return NULL; +} + +static void reverse_bytes(void *data, int length) +{ + int i = 0; + int j = length - 1; + uint8_t temp; + uint8_t *ptr = data; + + while (i < j) { + temp = ptr[i]; + ptr[i] = ptr[j]; + ptr[j] = temp; + i++; + j--; + } +} + +enum mrtags { + MRECREATE = 0x0045544145524345, + MREADD = 0x0000000044444145, + MREEXTEND = 0x00444E4554584545, +}; + +static bool mrenclave_update(EVP_MD_CTX *ctx, const void *data) +{ + if (!EVP_DigestUpdate(ctx, data, 64)) { + fprintf(stderr, "digest update failed\n"); + return false; + } + + return true; +} + +static bool mrenclave_commit(EVP_MD_CTX *ctx, uint8_t *mrenclave) +{ + unsigned int size; + + if (!EVP_DigestFinal_ex(ctx, (unsigned char *)mrenclave, &size)) { + fprintf(stderr, "digest commit failed\n"); + return false; + } + + if (size != 32) { + fprintf(stderr, "invalid digest size = %u\n", size); + return false; + } + + return true; +} + +struct mrecreate { + uint64_t tag; + uint32_t ssaframesize; + uint64_t size; + uint8_t reserved[44]; +} __attribute__((__packed__)); + + +static bool mrenclave_ecreate(EVP_MD_CTX *ctx, uint64_t blob_size) +{ + struct mrecreate mrecreate; + uint64_t encl_size; + + for (encl_size = 0x1000; encl_size < blob_size; ) + encl_size <<= 1; + + memset(&mrecreate, 0, sizeof(mrecreate)); + mrecreate.tag = MRECREATE; + mrecreate.ssaframesize = 1; + mrecreate.size = encl_size; + + if (!EVP_DigestInit_ex(ctx, EVP_sha256(), NULL)) + return false; + + return mrenclave_update(ctx, &mrecreate); +} + +struct mreadd { + uint64_t tag; + uint64_t offset; + uint64_t flags; /* SECINFO flags */ + uint8_t reserved[40]; +} __attribute__((__packed__)); + +static bool mrenclave_eadd(EVP_MD_CTX *ctx, uint64_t offset, uint64_t flags) +{ + struct mreadd mreadd; + + memset(&mreadd, 0, sizeof(mreadd)); + mreadd.tag = MREADD; + mreadd.offset = offset; + mreadd.flags = flags; + + return mrenclave_update(ctx, &mreadd); +} + +struct mreextend { + uint64_t tag; + uint64_t offset; + uint8_t reserved[48]; +} __attribute__((__packed__)); + +static bool mrenclave_eextend(EVP_MD_CTX *ctx, uint64_t offset, + const uint8_t *data) +{ + struct mreextend mreextend; + int i; + + for (i = 0; i < 0x1000; i += 0x100) { + memset(&mreextend, 0, sizeof(mreextend)); + mreextend.tag = MREEXTEND; + mreextend.offset = offset + i; + + if (!mrenclave_update(ctx, &mreextend)) + return false; + + if (!mrenclave_update(ctx, &data[i + 0x00])) + return false; + + if (!mrenclave_update(ctx, &data[i + 0x40])) + return false; + + if (!mrenclave_update(ctx, &data[i + 0x80])) + return false; + + if (!mrenclave_update(ctx, &data[i + 0xC0])) + return false; + } + + return true; +} + +static bool mrenclave_segment(EVP_MD_CTX *ctx, struct encl *encl, + struct encl_segment *seg) +{ + uint64_t end = seg->offset + seg->size; + uint64_t offset; + + for (offset = seg->offset; offset < end; offset += PAGE_SIZE) { + if (!mrenclave_eadd(ctx, offset, seg->flags)) + return false; + + if (!mrenclave_eextend(ctx, offset, encl->src + offset)) + return false; + } + + return true; +} + +bool encl_measure(struct encl *encl) +{ + uint64_t header1[2] = {0x000000E100000006, 0x0000000000010000}; + uint64_t header2[2] = {0x0000006000000101, 0x0000000100000060}; + struct sgx_sigstruct *sigstruct = &encl->sigstruct; + struct sgx_sigstruct_payload payload; + uint8_t digest[SHA256_DIGEST_LENGTH]; + unsigned int siglen; + RSA *key = NULL; + EVP_MD_CTX *ctx; + int i; + + memset(sigstruct, 0, sizeof(*sigstruct)); + + sigstruct->header.header1[0] = header1[0]; + sigstruct->header.header1[1] = header1[1]; + sigstruct->header.header2[0] = header2[0]; + sigstruct->header.header2[1] = header2[1]; + sigstruct->exponent = 3; + sigstruct->body.attributes = SGX_ATTR_MODE64BIT; + sigstruct->body.xfrm = 3; + + /* sanity check */ + if (check_crypto_errors()) + goto err; + + key = gen_sign_key(); + if (!key) + goto err; + + BN_bn2bin(get_modulus(key), sigstruct->modulus); + + ctx = EVP_MD_CTX_create(); + if (!ctx) + goto err; + + if (!mrenclave_ecreate(ctx, encl->src_size)) + goto err; + + for (i = 0; i < encl->nr_segments; i++) { + struct encl_segment *seg = &encl->segment_tbl[i]; + + if (!mrenclave_segment(ctx, encl, seg)) + goto err; + } + + if (!mrenclave_commit(ctx, sigstruct->body.mrenclave)) + goto err; + + memcpy(&payload.header, &sigstruct->header, sizeof(sigstruct->header)); + memcpy(&payload.body, &sigstruct->body, sizeof(sigstruct->body)); + + SHA256((unsigned char *)&payload, sizeof(payload), digest); + + if (!RSA_sign(NID_sha256, digest, SHA256_DIGEST_LENGTH, + sigstruct->signature, &siglen, key)) + goto err; + + if (!calc_q1q2(sigstruct->signature, sigstruct->modulus, sigstruct->q1, + sigstruct->q2)) + goto err; + + /* BE -> LE */ + reverse_bytes(sigstruct->signature, SGX_MODULUS_SIZE); + reverse_bytes(sigstruct->modulus, SGX_MODULUS_SIZE); + reverse_bytes(sigstruct->q1, SGX_MODULUS_SIZE); + reverse_bytes(sigstruct->q2, SGX_MODULUS_SIZE); + + EVP_MD_CTX_destroy(ctx); + RSA_free(key); + return true; + +err: + EVP_MD_CTX_destroy(ctx); + RSA_free(key); + return false; +} diff --git a/tools/testing/selftests/sgx/test_encl.c b/tools/testing/selftests/sgx/test_encl.c new file mode 100644 index 000000000000..ede915399742 --- /dev/null +++ b/tools/testing/selftests/sgx/test_encl.c @@ -0,0 +1,20 @@ +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) +// Copyright(c) 2016-18 Intel Corporation. + +#include +#include "defines.h" + +static void *memcpy(void *dest, const void *src, size_t n) +{ + size_t i; + + for (i = 0; i < n; i++) + ((char *)dest)[i] = ((char *)src)[i]; + + return dest; +} + +void encl_body(void *rdi, void *rsi) +{ + memcpy(rsi, rdi, 8); +} diff --git a/tools/testing/selftests/sgx/test_encl.lds b/tools/testing/selftests/sgx/test_encl.lds new file mode 100644 index 000000000000..0fbbda7e665e --- /dev/null +++ b/tools/testing/selftests/sgx/test_encl.lds @@ -0,0 +1,40 @@ +OUTPUT_FORMAT(elf64-x86-64) + +PHDRS +{ + tcs PT_LOAD; + text PT_LOAD; + data PT_LOAD; +} + +SECTIONS +{ + . = 0; + .tcs : { + *(.tcs*) + } : tcs + + . = ALIGN(4096); + .text : { + *(.text*) + *(.rodata*) + } : text + + . = ALIGN(4096); + .data : { + *(.data*) + } : data + + /DISCARD/ : { + *(.comment*) + *(.note*) + *(.debug*) + *(.eh_frame*) + } +} + +ASSERT(!DEFINED(.altinstructions), "ALTERNATIVES are not supported in enclaves") +ASSERT(!DEFINED(.altinstr_replacement), "ALTERNATIVES are not supported in enclaves") +ASSERT(!DEFINED(.discard.retpoline_safe), "RETPOLINE ALTERNATIVES are not supported in enclaves") +ASSERT(!DEFINED(.discard.nospec), "RETPOLINE ALTERNATIVES are not supported in enclaves") +ASSERT(!DEFINED(.got.plt), "Libcalls are not supported in enclaves") diff --git a/tools/testing/selftests/sgx/test_encl_bootstrap.S b/tools/testing/selftests/sgx/test_encl_bootstrap.S new file mode 100644 index 000000000000..6836ea86126e --- /dev/null +++ b/tools/testing/selftests/sgx/test_encl_bootstrap.S @@ -0,0 +1,89 @@ +/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */ +/* + * Copyright(c) 2016-18 Intel Corporation. + */ + + .macro ENCLU + .byte 0x0f, 0x01, 0xd7 + .endm + + .section ".tcs", "aw" + .balign 4096 + + .fill 1, 8, 0 # STATE (set by CPU) + .fill 1, 8, 0 # FLAGS + .quad encl_ssa # OSSA + .fill 1, 4, 0 # CSSA (set by CPU) + .fill 1, 4, 1 # NSSA + .quad encl_entry # OENTRY + .fill 1, 8, 0 # AEP (set by EENTER and ERESUME) + .fill 1, 8, 0 # OFSBASE + .fill 1, 8, 0 # OGSBASE + .fill 1, 4, 0xFFFFFFFF # FSLIMIT + .fill 1, 4, 0xFFFFFFFF # GSLIMIT + .fill 4024, 1, 0 # Reserved + + # Identical to the previous TCS. + .fill 1, 8, 0 # STATE (set by CPU) + .fill 1, 8, 0 # FLAGS + .quad encl_ssa # OSSA + .fill 1, 4, 0 # CSSA (set by CPU) + .fill 1, 4, 1 # NSSA + .quad encl_entry # OENTRY + .fill 1, 8, 0 # AEP (set by EENTER and ERESUME) + .fill 1, 8, 0 # OFSBASE + .fill 1, 8, 0 # OGSBASE + .fill 1, 4, 0xFFFFFFFF # FSLIMIT + .fill 1, 4, 0xFFFFFFFF # GSLIMIT + .fill 4024, 1, 0 # Reserved + + .text + +encl_entry: + # RBX contains the base address for TCS, which is also the first address + # inside the enclave. By adding the value of le_stack_end to it, we get + # the absolute address for the stack. + lea (encl_stack)(%rbx), %rax + xchg %rsp, %rax + push %rax + + push %rcx # push the address after EENTER + push %rbx # push the enclave base address + + call encl_body + + pop %rbx # pop the enclave base address + + /* Clear volatile GPRs, except RAX (EEXIT leaf). */ + xor %rcx, %rcx + xor %rdx, %rdx + xor %rdi, %rdi + xor %rsi, %rsi + xor %r8, %r8 + xor %r9, %r9 + xor %r10, %r10 + xor %r11, %r11 + + # Reset status flags. + add %rdx, %rdx # OF = SF = AF = CF = 0; ZF = PF = 1 + + # Prepare EEXIT target by popping the address of the instruction after + # EENTER to RBX. + pop %rbx + + # Restore the caller stack. + pop %rax + mov %rax, %rsp + + # EEXIT + mov $4, %rax + enclu + + .section ".data", "aw" + +encl_ssa: + .space 4096 + + .balign 4096 + .space 8192 +encl_stack: From patchwork Tue Apr 21 21:53:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11502377 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 80D9A913 for ; Tue, 21 Apr 2020 21:55:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6A63D20735 for ; Tue, 21 Apr 2020 21:55:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726702AbgDUVzX (ORCPT ); Tue, 21 Apr 2020 17:55:23 -0400 Received: from mga18.intel.com ([134.134.136.126]:11705 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726055AbgDUVzW (ORCPT ); Tue, 21 Apr 2020 17:55:22 -0400 IronPort-SDR: WqL6g9l4FIoAJ3K6mjwGJ6WlLBWRlGUWQEDRxwntnIPuQ3mizy4+iLBnwdoNtmO6HxLcIEcC0J SM7++ISvRboA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:55:21 -0700 IronPort-SDR: PSHy7yy9eTa9HV4sz3CJu1qGIEfHb1z0PQlm7f1cN2QRDZaK/yNKhkILu3Av9WZVa69dwQWKTR XKPXMyaIzoTQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="456260934" Received: from mnchalux-mobl2.gar.corp.intel.com (HELO localhost) ([10.252.44.234]) by fmsmga005.fm.intel.com with ESMTP; 21 Apr 2020 14:55:16 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, Jarkko Sakkinen , linux-doc@vger.kernel.org, Randy Dunlap Subject: [PATCH v29 20/20] docs: x86/sgx: Document SGX micro architecture and kernel internals Date: Wed, 22 Apr 2020 00:53:16 +0300 Message-Id: <20200421215316.56503-21-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> References: <20200421215316.56503-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org Document the Intel SGX kernel architecture. The fine-grained micro architecture details can be looked up from Intel SDM Volume 3D. Cc: linux-doc@vger.kernel.org Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson Acked-by: Randy Dunlap Signed-off-by: Jarkko Sakkinen --- Documentation/x86/index.rst | 1 + Documentation/x86/sgx.rst | 206 ++++++++++++++++++++++++++++++++++++ 2 files changed, 207 insertions(+) create mode 100644 Documentation/x86/sgx.rst diff --git a/Documentation/x86/index.rst b/Documentation/x86/index.rst index a8de2fbc1caa..971f30a7d166 100644 --- a/Documentation/x86/index.rst +++ b/Documentation/x86/index.rst @@ -31,3 +31,4 @@ x86-specific Documentation usb-legacy-support i386/index x86_64/index + sgx diff --git a/Documentation/x86/sgx.rst b/Documentation/x86/sgx.rst new file mode 100644 index 000000000000..9609a3409ad1 --- /dev/null +++ b/Documentation/x86/sgx.rst @@ -0,0 +1,206 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============ +Architecture +============ + +*Software Guard eXtensions (SGX)* is a set of instructions that enable ring-3 +applications to set aside private regions of code and data. These regions are +called enclaves. An enclave can be entered to a fixed set of entry points. Only +a CPU running inside the enclave can access its code and data. + +The support can be determined by + + ``grep sgx /proc/cpuinfo`` + +Enclave Page Cache +================== + +SGX utilizes an *Enclave Page Cache (EPC)* to store pages that are associated +with an enclave. It is contained in a BIOS reserved region of physical memory. +Unlike pages used for regular memory, pages can only be accessed outside the +enclave for different purposes with the instructions **ENCLS**, **ENCLV** and +**ENCLU**. + +Direct memory accesses to an enclave can be only done by a CPU executing inside +the enclave. An enclave can be entered with **ENCLU[EENTER]** to a fixed set of +entry points. However, a CPU executing inside the enclave can do outside memory +accesses. + +Page Types +---------- + +**SGX Enclave Control Structure (SECS)** + Enclave's address range, attributes and other global data are defined + by this structure. + +**Regular (REG)** + Regular EPC pages contain the code and data of an enclave. + +**Thread Control Structure (TCS)** + Thread Control Structure pages define the entry points to an enclave and + track the execution state of an enclave thread. + +**Version Array (VA)** + Version Array pages contain 512 slots, each of which can contain a version + number for a page evicted from the EPC. + +Enclave Page Cache Map +---------------------- + +The processor tracks EPC pages via the *Enclave Page Cache Map (EPCM)*. EPCM +contains an entry for each EPC page, which describes the owning enclave, access +rights and page type among the other things. + +The permissions from EPCM is consulted if and only if walking the kernel page +tables succeeds. The total permissions are thus a conjunction between page table +and EPCM permissions. + +For all intents and purposes the SGX architecture allows the processor to +invalidate all EPCM entries at will, i.e. requires that software be prepared to +handle an EPCM fault at any time. The contents of EPC are encrypted with an +ephemeral key, which is lost on power transitions. + +EPC management +============== + +EPC pages do not have ``struct page`` instances. They are IO memory from kernel +perspective. The consequence is that they are always mapped as shared memory. +Kernel defines ``/dev/sgx/enclave`` that can be mapped as ``MAP_SHARED`` to +define the address range for an enclave. + +EPC Over-subscription +===================== + +When the amount of free EPC pages goes below a low watermark the swapping thread +starts reclaiming pages. The pages that do not have the **A** bit set are +selected as victim pages. + +Launch Control +============== + +SGX provides a launch control mechanism. After all enclave pages have been +copied, kernel executes **ENCLS[EINIT]**, which initializes the enclave. Only +after this the CPU can execute inside the enclave. + +This leaf function takes an RSA-3072 signature of the enclave measurement and an +optional cryptographic token. Linux does not take advantage of launch tokens. +The instruction checks that the signature is signed with the key defined in +**IA32_SGXLEPUBKEYHASH?** MSRs and the measurement is correct. If so, the +enclave is allowed to be executed. + +MSRs can be configured by the BIOS to be either readable or writable. Linux +supports only writable configuration in order to give full control to the kernel +on launch control policy. Readable configuration requires the use of previously +mentioned launch tokens. + +The current kernel implementation supports only writable MSRs. The launch is +performed by setting the MSRs to the hash of the enclave signer's public key. +The alternative would be to have *a launch enclave* that would be signed with +the key set into MSRs, which would then generate launch tokens for other +enclaves. This would only make sense with read-only MSRs, and thus the option +has been discarded. + +Attestation +=========== + +Local Attestation +----------------- + +In local attestation an enclave creates a **REPORT** data structure with +**ENCLS[EREPORT]**, which describes the origin of an enclave. In particular, it +contains a AES-CMAC of the enclave contents signed with a report key unique to +each processor. All enclaves have access to this key. + +This mechanism can also be used in addition as a communication channel as the +**REPORT** data structure includes a 64-byte field for variable information. + +Remote Attestation +------------------ + +For remote attestation (or provisioning) there are schemes available: + +* EPID scheme, which requires the use of Intel managed attestation service. +* ECDSA scheme, which allows a 3rd party to act as an attestation service. + +Intel has released an open source *Quoting Enclave (QE)* and *Provisioning +Certification Enclave (PCE)* for the ECDSA based scheme. A PCE is used to +certify the locally used QE's. + +Intel also provides a proprietary of the PCE. This is a necessary when one +needs to be able to prove that an enclave is running on real hardware. To +achieve this the enclave needs to be rooted to the Intel's PKI, which obviously +cannot be exposed to 3rd parties. + +Both schemes require **ATTRIBUTES.PROVISIONKEY** but only EPID scheme uses the +on-die provisioning key. This privilege should be under normal conditions given +only to QE's because uncontrolled use of attestation could be used by malware +for benefit. + +Encryption engines +================== + +In order to conceal the enclave data while it is out of the CPU package, +memory controller has to be extended with an encryption engine. MC can then +route incoming requests coming from CPU cores running in enclave mode to the +encryption engine. + +In CPUs prior to Icelake, Memory Encryption Engine (MEE) is used to +encrypt pages leaving the CPU caches. MEE uses a n-ary Merkle tree with root in +SRAM to maintain integrity of the encrypted data. This provides integrity and +anti-replay protection but does not scale to large memory sizes because the time +required to update the Merkle tree grows logarithmically in relation to the +memory size. + +CPUs starting from Icelake use Total Memory Encryption (TME) in the place of +MEE. TME throws away the Merkle tree, which means losing integrity and +anti-replay protection but also enables variable size memory pools for EPC. +Using this attack for benefit would require an interposer on the system bus. + +Backing storage +=============== + +Backing storage is shared and not accounted. It is implemented as a private +shmem file. Providing a backing storage in some form from user space is not +possible - accounting would go to invalid state as reclaimed pages would get +accounted to the processes of which behalf the kernel happened to be acting on. + +Access control +============== + +`mmap()` permissions are capped by the enclave permissions. A direct +consequence of this is that all the pages for an address range must be added +before `mmap()` can be applied. Effectively an enclave page with minimum +permission in the address range sets the permission cap for the mapping +operation. + +Usage Models +============ + +Shared Library +-------------- + +Sensitive data and the code that acts on it is partitioned from the application +into a separate library. The library is then linked as a DSO which can be loaded +into an enclave. The application can then make individual function calls into +the enclave through special SGX instructions. A run-time within the enclave is +configured to marshal function parameters into and out of the enclave and to +call the correct library function. + +Application Container +--------------------- + +An application may be loaded into a container enclave which is specially +configured with a library OS and run-time which permits the application to run. +The enclave run-time and library OS work together to execute the application +when a thread enters the enclave. + +References +========== + +"Intel® Software Guard Extensions: EPID Provisioning and Attestation Services" + https://software.intel.com/sites/default/files/managed/57/0e/ww10-2016-sgx-provisioning-and-attestation-final.pdf + +"Supporting Third Party Attestation for Intel® SGX with Intel® Data Center +Attestation Primitives" + https://software.intel.com/sites/default/files/managed/f1/b8/intel-sgx-support-for-third-party-attestation.pdf