diff options
| -rw-r--r-- | arch/x86/include/asm/cpufeatures.h | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/sgx.h | 97 | ||||
| -rw-r--r-- | arch/x86/include/uapi/asm/sgx.h | 10 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/cpuid-deps.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/scattered.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/sgx/driver.c | 19 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/sgx/encl.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/sgx/encls.h | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/sgx/main.c | 101 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/sgx/sgx.h | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/sgx/virt.c | 20 |
11 files changed, 210 insertions, 49 deletions
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index ee8876bbb10e..9e54fc0e7ed3 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -499,6 +499,7 @@ #define X86_FEATURE_IBPB_EXIT_TO_USER (21*32+14) /* Use IBPB on exit-to-userspace, see VMSCAPE bug */ #define X86_FEATURE_ABMC (21*32+15) /* Assignable Bandwidth Monitoring Counters */ #define X86_FEATURE_MSR_IMM (21*32+16) /* MSR immediate form instructions */ +#define X86_FEATURE_SGX_EUPDATESVN (21*32+17) /* Support for ENCLS[EUPDATESVN] instruction */ #define X86_FEATURE_SDCIAE (21*32+18) /* L3 Smart Data Cache Injection Allocation Enforcement */ diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h index 6a0069761508..04958459a7ca 100644 --- a/arch/x86/include/asm/sgx.h +++ b/arch/x86/include/asm/sgx.h @@ -1,5 +1,5 @@ /* SPDX-License-Identifier: GPL-2.0 */ -/** +/* * Copyright(c) 2016-20 Intel Corporation. * * Intel Software Guard Extensions (SGX) support. @@ -28,21 +28,22 @@ #define SGX_CPUID_EPC_MASK GENMASK(3, 0) enum sgx_encls_function { - ECREATE = 0x00, - EADD = 0x01, - EINIT = 0x02, - EREMOVE = 0x03, - EDGBRD = 0x04, - EDGBWR = 0x05, - EEXTEND = 0x06, - ELDU = 0x08, - EBLOCK = 0x09, - EPA = 0x0A, - EWB = 0x0B, - ETRACK = 0x0C, - EAUG = 0x0D, - EMODPR = 0x0E, - EMODT = 0x0F, + ECREATE = 0x00, + EADD = 0x01, + EINIT = 0x02, + EREMOVE = 0x03, + EDGBRD = 0x04, + EDGBWR = 0x05, + EEXTEND = 0x06, + ELDU = 0x08, + EBLOCK = 0x09, + EPA = 0x0A, + EWB = 0x0B, + ETRACK = 0x0C, + EAUG = 0x0D, + EMODPR = 0x0E, + EMODT = 0x0F, + EUPDATESVN = 0x18, }; /** @@ -65,15 +66,19 @@ enum sgx_encls_function { /** * enum sgx_return_code - The return code type for ENCLS, ENCLU and ENCLV - * %SGX_EPC_PAGE_CONFLICT: Page is being written by other ENCLS function. - * %SGX_NOT_TRACKED: Previous ETRACK's shootdown sequence has not + * @SGX_EPC_PAGE_CONFLICT: Page is being written by other ENCLS function. + * @SGX_NOT_TRACKED: Previous ETRACK's shootdown sequence has not * been completed yet. - * %SGX_CHILD_PRESENT SECS has child pages present in the EPC. - * %SGX_INVALID_EINITTOKEN: EINITTOKEN is invalid and enclave signer's + * @SGX_CHILD_PRESENT: SECS has child pages present in the EPC. + * @SGX_INVALID_EINITTOKEN: EINITTOKEN is invalid and enclave signer's * public key does not match IA32_SGXLEPUBKEYHASH. - * %SGX_PAGE_NOT_MODIFIABLE: The EPC page cannot be modified because it + * @SGX_PAGE_NOT_MODIFIABLE: The EPC page cannot be modified because it * is in the PENDING or MODIFIED state. - * %SGX_UNMASKED_EVENT: An unmasked event, e.g. INTR, was received + * @SGX_INSUFFICIENT_ENTROPY: Insufficient entropy in RNG. + * @SGX_NO_UPDATE: EUPDATESVN could not update the CPUSVN because the + * current SVN was not newer than CPUSVN. This is the most + * common error code returned by EUPDATESVN. + * @SGX_UNMASKED_EVENT: An unmasked event, e.g. INTR, was received */ enum sgx_return_code { SGX_EPC_PAGE_CONFLICT = 7, @@ -81,6 +86,8 @@ enum sgx_return_code { SGX_CHILD_PRESENT = 13, SGX_INVALID_EINITTOKEN = 16, SGX_PAGE_NOT_MODIFIABLE = 20, + SGX_INSUFFICIENT_ENTROPY = 29, + SGX_NO_UPDATE = 31, SGX_UNMASKED_EVENT = 128, }; @@ -89,7 +96,7 @@ enum sgx_return_code { /** * enum sgx_miscselect - additional information to an SSA frame - * %SGX_MISC_EXINFO: Report #PF or #GP to the 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 @@ -105,17 +112,17 @@ enum sgx_miscselect { #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 + * enum sgx_attribute - 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 + * @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. - * %SGX_ATTR_ASYNC_EXIT_NOTIFY: Allow enclaves to be notified after an + * @SGX_ATTR_ASYNC_EXIT_NOTIFY: Allow enclaves to be notified after an * asynchronous exit has occurred. */ enum sgx_attribute { @@ -188,7 +195,7 @@ struct sgx_secs { /** * enum sgx_tcs_flags - execution flags for TCS - * %SGX_TCS_DBGOPTIN: If enabled allows single-stepping and breakpoints + * @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. */ @@ -253,11 +260,11 @@ struct sgx_pageinfo { /** * 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 + * @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 * * Make sure when making changes to this enum that its values can still fit * in the bitfield within &struct sgx_encl_page @@ -275,14 +282,14 @@ enum sgx_page_type { /** * 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 + * @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), diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h index 2dd35bbdc822..3c4d52072189 100644 --- a/arch/x86/include/uapi/asm/sgx.h +++ b/arch/x86/include/uapi/asm/sgx.h @@ -10,7 +10,7 @@ /** * enum sgx_page_flags - page control flags - * %SGX_PAGE_MEASURE: Measure the page contents with a sequence of + * @SGX_PAGE_MEASURE: Measure the page contents with a sequence of * ENCLS[EEXTEND] operations. */ enum sgx_page_flags { @@ -143,6 +143,12 @@ struct sgx_enclave_run; /** * typedef sgx_enclave_user_handler_t - Exit handler function accepted by * __vdso_sgx_enter_enclave() + * @rdi: RDI at the time of EEXIT, undefined on AEX + * @rsi: RSI at the time of EEXIT, undefined on AEX + * @rdx: RDX at the time of EEXIT, undefined on AEX + * @rsp: RSP (untrusted) at the time of EEXIT or AEX + * @r8: R8 at the time of EEXIT, undefined on AEX + * @r9: R9 at the time of EEXIT, undefined on AEX * @run: The run instance given by the caller * * The register parameters contain the snapshot of their values at enclave @@ -166,7 +172,7 @@ typedef int (*sgx_enclave_user_handler_t)(long rdi, long rsi, long rdx, * @exception_addr: The address that triggered the exception * @user_handler: User provided callback run on exception * @user_data: Data passed to the user handler - * @reserved Reserved for future extensions + * @reserved: Reserved for future extensions * * If @user_handler is provided, the handler will be invoked on all return paths * of the normal flow. The user handler may transfer control, e.g. via a diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c index 87e78586395b..a40f5545e25b 100644 --- a/arch/x86/kernel/cpu/cpuid-deps.c +++ b/arch/x86/kernel/cpu/cpuid-deps.c @@ -80,6 +80,7 @@ static const struct cpuid_dep cpuid_deps[] = { { X86_FEATURE_SGX_LC, X86_FEATURE_SGX }, { X86_FEATURE_SGX1, X86_FEATURE_SGX }, { X86_FEATURE_SGX2, X86_FEATURE_SGX1 }, + { X86_FEATURE_SGX_EUPDATESVN, X86_FEATURE_SGX1 }, { X86_FEATURE_SGX_EDECCSSA, X86_FEATURE_SGX1 }, { X86_FEATURE_XFD, X86_FEATURE_XSAVES }, { X86_FEATURE_XFD, X86_FEATURE_XGETBV1 }, diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c index d113863a8eab..0524ac0260fc 100644 --- a/arch/x86/kernel/cpu/scattered.c +++ b/arch/x86/kernel/cpu/scattered.c @@ -43,6 +43,7 @@ static const struct cpuid_bit cpuid_bits[] = { { X86_FEATURE_PER_THREAD_MBA, CPUID_ECX, 0, 0x00000010, 3 }, { X86_FEATURE_SGX1, CPUID_EAX, 0, 0x00000012, 0 }, { X86_FEATURE_SGX2, CPUID_EAX, 1, 0x00000012, 0 }, + { X86_FEATURE_SGX_EUPDATESVN, CPUID_EAX, 10, 0x00000012, 0 }, { X86_FEATURE_SGX_EDECCSSA, CPUID_EAX, 11, 0x00000012, 0 }, { X86_FEATURE_HW_PSTATE, CPUID_EDX, 7, 0x80000007, 0 }, { X86_FEATURE_CPB, CPUID_EDX, 9, 0x80000007, 0 }, diff --git a/arch/x86/kernel/cpu/sgx/driver.c b/arch/x86/kernel/cpu/sgx/driver.c index 7f8d1e11dbee..79d6020dfe9c 100644 --- a/arch/x86/kernel/cpu/sgx/driver.c +++ b/arch/x86/kernel/cpu/sgx/driver.c @@ -14,7 +14,7 @@ u64 sgx_attributes_reserved_mask; u64 sgx_xfrm_reserved_mask = ~0x3; u32 sgx_misc_reserved_mask; -static int sgx_open(struct inode *inode, struct file *file) +static int __sgx_open(struct inode *inode, struct file *file) { struct sgx_encl *encl; int ret; @@ -41,6 +41,23 @@ static int sgx_open(struct inode *inode, struct file *file) return 0; } +static int sgx_open(struct inode *inode, struct file *file) +{ + int ret; + + ret = sgx_inc_usage_count(); + if (ret) + return ret; + + ret = __sgx_open(inode, file); + if (ret) { + sgx_dec_usage_count(); + return ret; + } + + return 0; +} + static int sgx_release(struct inode *inode, struct file *file) { struct sgx_encl *encl = file->private_data; diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c index 308dbbae6c6e..cf149b9f4916 100644 --- a/arch/x86/kernel/cpu/sgx/encl.c +++ b/arch/x86/kernel/cpu/sgx/encl.c @@ -765,6 +765,7 @@ void sgx_encl_release(struct kref *ref) WARN_ON_ONCE(encl->secs.epc_page); kfree(encl); + sgx_dec_usage_count(); } /* diff --git a/arch/x86/kernel/cpu/sgx/encls.h b/arch/x86/kernel/cpu/sgx/encls.h index 42a088a337c5..74be751199a4 100644 --- a/arch/x86/kernel/cpu/sgx/encls.h +++ b/arch/x86/kernel/cpu/sgx/encls.h @@ -233,4 +233,9 @@ static inline int __eaug(struct sgx_pageinfo *pginfo, void *addr) return __encls_2(EAUG, pginfo, addr); } +/* Attempt to update CPUSVN at runtime. */ +static inline int __eupdatesvn(void) +{ + return __encls_ret_1(EUPDATESVN, ""); +} #endif /* _X86_ENCLS_H */ diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index 2de01b379aa3..3eda7e7942e6 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -16,6 +16,7 @@ #include <linux/vmalloc.h> #include <asm/msr.h> #include <asm/sgx.h> +#include <asm/archrandom.h> #include "driver.h" #include "encl.h" #include "encls.h" @@ -917,6 +918,106 @@ int sgx_set_attribute(unsigned long *allowed_attributes, } EXPORT_SYMBOL_GPL(sgx_set_attribute); +/* Counter to count the active SGX users */ +static int sgx_usage_count; + +/** + * sgx_update_svn() - Attempt to call ENCLS[EUPDATESVN]. + * + * This instruction attempts to update CPUSVN to the + * currently loaded microcode update SVN and generate new + * cryptographic assets. + * + * Return: + * * %0: - Success or not supported + * * %-EAGAIN: - Can be safely retried, failure is due to lack of + * * entropy in RNG + * * %-EIO: - Unexpected error, retries are not advisable + */ +static int sgx_update_svn(void) +{ + int ret; + + /* + * If EUPDATESVN is not available, it is ok to + * silently skip it to comply with legacy behavior. + */ + if (!cpu_feature_enabled(X86_FEATURE_SGX_EUPDATESVN)) + return 0; + + /* + * EPC is guaranteed to be empty when there are no users. + * Ensure we are on our first user before proceeding further. + */ + WARN(sgx_usage_count, "Elevated usage count when calling EUPDATESVN\n"); + + for (int i = 0; i < RDRAND_RETRY_LOOPS; i++) { + ret = __eupdatesvn(); + + /* Stop on success or unexpected errors: */ + if (ret != SGX_INSUFFICIENT_ENTROPY) + break; + } + + switch (ret) { + case 0: + /* + * SVN successfully updated. + * Let users know when the update was successful. + */ + pr_info("SVN updated successfully\n"); + return 0; + case SGX_NO_UPDATE: + /* + * SVN update failed since the current SVN is + * not newer than CPUSVN. This is the most + * common case and indicates no harm. + */ + return 0; + case SGX_INSUFFICIENT_ENTROPY: + /* + * SVN update failed due to lack of entropy in DRNG. + * Indicate to userspace that it should retry. + */ + return -EAGAIN; + default: + break; + } + + /* + * EUPDATESVN was called when EPC is empty, all other error + * codes are unexpected. + */ + ENCLS_WARN(ret, "EUPDATESVN"); + return -EIO; +} + +/* Mutex to ensure no concurrent EPC accesses during EUPDATESVN */ +static DEFINE_MUTEX(sgx_svn_lock); + +int sgx_inc_usage_count(void) +{ + int ret; + + guard(mutex)(&sgx_svn_lock); + + if (!sgx_usage_count) { + ret = sgx_update_svn(); + if (ret) + return ret; + } + + sgx_usage_count++; + + return 0; +} + +void sgx_dec_usage_count(void) +{ + guard(mutex)(&sgx_svn_lock); + sgx_usage_count--; +} + static int __init sgx_init(void) { int ret; diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index d2dad21259a8..f5940393d9bd 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -102,6 +102,9 @@ static inline int __init sgx_vepc_init(void) } #endif +int sgx_inc_usage_count(void); +void sgx_dec_usage_count(void); + void sgx_update_lepubkeyhash(u64 *lepubkeyhash); #endif /* _X86_SGX_H */ diff --git a/arch/x86/kernel/cpu/sgx/virt.c b/arch/x86/kernel/cpu/sgx/virt.c index 7aaa3652e31d..b649c0610019 100644 --- a/arch/x86/kernel/cpu/sgx/virt.c +++ b/arch/x86/kernel/cpu/sgx/virt.c @@ -255,10 +255,11 @@ static int sgx_vepc_release(struct inode *inode, struct file *file) xa_destroy(&vepc->page_array); kfree(vepc); + sgx_dec_usage_count(); return 0; } -static int sgx_vepc_open(struct inode *inode, struct file *file) +static int __sgx_vepc_open(struct inode *inode, struct file *file) { struct sgx_vepc *vepc; @@ -273,6 +274,23 @@ static int sgx_vepc_open(struct inode *inode, struct file *file) return 0; } +static int sgx_vepc_open(struct inode *inode, struct file *file) +{ + int ret; + + ret = sgx_inc_usage_count(); + if (ret) + return ret; + + ret = __sgx_vepc_open(inode, file); + if (ret) { + sgx_dec_usage_count(); + return ret; + } + + return 0; +} + static long sgx_vepc_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { |