diff --git a/Documentation/x86/sgx.rst b/Documentation/x86/sgx.rst index 265568a9292c..2bcbffacbed5 100644 --- a/Documentation/x86/sgx.rst +++ b/Documentation/x86/sgx.rst @@ -100,6 +100,21 @@ pages and establish enclave page permissions. sgx_ioc_enclave_init sgx_ioc_enclave_provision +Enclave runtime management +-------------------------- + +Systems supporting SGX2 additionally support changes to initialized +enclaves: modifying enclave page permissions and type, and dynamically +adding and removing of enclave pages. When an enclave accesses an address +within its address range that does not have a backing page then a new +regular page will be dynamically added to the enclave. The enclave is +still required to run EACCEPT on the new page before it can be used. + +.. kernel-doc:: arch/x86/kernel/cpu/sgx/ioctl.c + :functions: sgx_ioc_enclave_restrict_permissions + sgx_ioc_enclave_modify_types + sgx_ioc_enclave_remove_pages + Enclave vDSO ------------ diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h index 3f9334ef67cd..eae20fa52b93 100644 --- a/arch/x86/include/asm/sgx.h +++ b/arch/x86/include/asm/sgx.h @@ -65,17 +65,22 @@ 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 * been completed yet. * %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 + * is in the PENDING or MODIFIED state. * %SGX_UNMASKED_EVENT: An unmasked event, e.g. INTR, was received */ enum sgx_return_code { + SGX_EPC_PAGE_CONFLICT = 7, SGX_NOT_TRACKED = 11, SGX_CHILD_PRESENT = 13, SGX_INVALID_EINITTOKEN = 16, + SGX_PAGE_NOT_MODIFIABLE = 20, SGX_UNMASKED_EVENT = 128, }; @@ -234,6 +239,9 @@ struct sgx_pageinfo { * %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 */ enum sgx_page_type { SGX_PAGE_TYPE_SECS, diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h index f4b81587e90b..2dd35bbdc822 100644 --- a/arch/x86/include/uapi/asm/sgx.h +++ b/arch/x86/include/uapi/asm/sgx.h @@ -29,6 +29,12 @@ enum sgx_page_flags { _IOW(SGX_MAGIC, 0x03, struct sgx_enclave_provision) #define SGX_IOC_VEPC_REMOVE_ALL \ _IO(SGX_MAGIC, 0x04) +#define SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS \ + _IOWR(SGX_MAGIC, 0x05, struct sgx_enclave_restrict_permissions) +#define SGX_IOC_ENCLAVE_MODIFY_TYPES \ + _IOWR(SGX_MAGIC, 0x06, struct sgx_enclave_modify_types) +#define SGX_IOC_ENCLAVE_REMOVE_PAGES \ + _IOWR(SGX_MAGIC, 0x07, struct sgx_enclave_remove_pages) /** * struct sgx_enclave_create - parameter structure for the @@ -76,6 +82,62 @@ struct sgx_enclave_provision { __u64 fd; }; +/** + * struct sgx_enclave_restrict_permissions - parameters for ioctl + * %SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS + * @offset: starting page offset (page aligned relative to enclave base + * address defined in SECS) + * @length: length of memory (multiple of the page size) + * @permissions:new permission bits for pages in range described by @offset + * and @length + * @result: (output) SGX result code of ENCLS[EMODPR] function + * @count: (output) bytes successfully changed (multiple of page size) + */ +struct sgx_enclave_restrict_permissions { + __u64 offset; + __u64 length; + __u64 permissions; + __u64 result; + __u64 count; +}; + +/** + * struct sgx_enclave_modify_types - parameters for ioctl + * %SGX_IOC_ENCLAVE_MODIFY_TYPES + * @offset: starting page offset (page aligned relative to enclave base + * address defined in SECS) + * @length: length of memory (multiple of the page size) + * @page_type: new type for pages in range described by @offset and @length + * @result: (output) SGX result code of ENCLS[EMODT] function + * @count: (output) bytes successfully changed (multiple of page size) + */ +struct sgx_enclave_modify_types { + __u64 offset; + __u64 length; + __u64 page_type; + __u64 result; + __u64 count; +}; + +/** + * struct sgx_enclave_remove_pages - %SGX_IOC_ENCLAVE_REMOVE_PAGES parameters + * @offset: starting page offset (page aligned relative to enclave base + * address defined in SECS) + * @length: length of memory (multiple of the page size) + * @count: (output) bytes successfully changed (multiple of page size) + * + * Regular (PT_REG) or TCS (PT_TCS) can be removed from an initialized + * enclave if the system supports SGX2. First, the %SGX_IOC_ENCLAVE_MODIFY_TYPES + * ioctl() should be used to change the page type to PT_TRIM. After that + * succeeds ENCLU[EACCEPT] should be run from within the enclave and then + * %SGX_IOC_ENCLAVE_REMOVE_PAGES can be used to complete the page removal. + */ +struct sgx_enclave_remove_pages { + __u64 offset; + __u64 length; + __u64 count; +}; + struct sgx_enclave_run; /** diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c index 19876ebfb504..24c1bb8eb196 100644 --- a/arch/x86/kernel/cpu/sgx/encl.c +++ b/arch/x86/kernel/cpu/sgx/encl.c @@ -232,25 +232,10 @@ static struct sgx_epc_page *sgx_encl_eldu(struct sgx_encl_page *encl_page, return epc_page; } -static struct sgx_encl_page *sgx_encl_load_page(struct sgx_encl *encl, - unsigned long addr, - unsigned long vm_flags) +static struct sgx_encl_page *__sgx_encl_load_page(struct sgx_encl *encl, + struct sgx_encl_page *entry) { - unsigned long vm_prot_bits = vm_flags & (VM_READ | VM_WRITE | VM_EXEC); struct sgx_epc_page *epc_page; - struct sgx_encl_page *entry; - - entry = xa_load(&encl->page_array, PFN_DOWN(addr)); - if (!entry) - return ERR_PTR(-EFAULT); - - /* - * Verify that the faulted page has equal or higher build time - * permissions than the VMA permissions (i.e. the subset of {VM_READ, - * VM_WRITE, VM_EXECUTE} in vma->vm_flags). - */ - if ((entry->vm_max_prot_bits & vm_prot_bits) != vm_prot_bits) - return ERR_PTR(-EFAULT); /* Entry successfully located. */ if (entry->epc_page) { @@ -276,6 +261,146 @@ static struct sgx_encl_page *sgx_encl_load_page(struct sgx_encl *encl, return entry; } +static struct sgx_encl_page *sgx_encl_load_page_in_vma(struct sgx_encl *encl, + unsigned long addr, + unsigned long vm_flags) +{ + unsigned long vm_prot_bits = vm_flags & (VM_READ | VM_WRITE | VM_EXEC); + struct sgx_encl_page *entry; + + entry = xa_load(&encl->page_array, PFN_DOWN(addr)); + if (!entry) + return ERR_PTR(-EFAULT); + + /* + * Verify that the page has equal or higher build time + * permissions than the VMA permissions (i.e. the subset of {VM_READ, + * VM_WRITE, VM_EXECUTE} in vma->vm_flags). + */ + if ((entry->vm_max_prot_bits & vm_prot_bits) != vm_prot_bits) + return ERR_PTR(-EFAULT); + + return __sgx_encl_load_page(encl, entry); +} + +struct sgx_encl_page *sgx_encl_load_page(struct sgx_encl *encl, + unsigned long addr) +{ + struct sgx_encl_page *entry; + + entry = xa_load(&encl->page_array, PFN_DOWN(addr)); + if (!entry) + return ERR_PTR(-EFAULT); + + return __sgx_encl_load_page(encl, entry); +} + +/** + * sgx_encl_eaug_page() - Dynamically add page to initialized enclave + * @vma: VMA obtained from fault info from where page is accessed + * @encl: enclave accessing the page + * @addr: address that triggered the page fault + * + * When an initialized enclave accesses a page with no backing EPC page + * on a SGX2 system then the EPC can be added dynamically via the SGX2 + * ENCLS[EAUG] instruction. + * + * Returns: Appropriate vm_fault_t: VM_FAULT_NOPAGE when PTE was installed + * successfully, VM_FAULT_SIGBUS or VM_FAULT_OOM as error otherwise. + */ +static vm_fault_t sgx_encl_eaug_page(struct vm_area_struct *vma, + struct sgx_encl *encl, unsigned long addr) +{ + vm_fault_t vmret = VM_FAULT_SIGBUS; + struct sgx_pageinfo pginfo = {0}; + struct sgx_encl_page *encl_page; + struct sgx_epc_page *epc_page; + struct sgx_va_page *va_page; + unsigned long phys_addr; + u64 secinfo_flags; + int ret; + + if (!test_bit(SGX_ENCL_INITIALIZED, &encl->flags)) + return VM_FAULT_SIGBUS; + + /* + * Ignore internal permission checking for dynamically added pages. + * They matter only for data added during the pre-initialization + * phase. The enclave decides the permissions by the means of + * EACCEPT, EACCEPTCOPY and EMODPE. + */ + secinfo_flags = SGX_SECINFO_R | SGX_SECINFO_W | SGX_SECINFO_X; + encl_page = sgx_encl_page_alloc(encl, addr - encl->base, secinfo_flags); + if (IS_ERR(encl_page)) + return VM_FAULT_OOM; + + mutex_lock(&encl->lock); + + epc_page = sgx_alloc_epc_page(encl_page, false); + if (IS_ERR(epc_page)) { + if (PTR_ERR(epc_page) == -EBUSY) + vmret = VM_FAULT_NOPAGE; + goto err_out_unlock; + } + + va_page = sgx_encl_grow(encl, false); + if (IS_ERR(va_page)) + goto err_out_epc; + + if (va_page) + list_add(&va_page->list, &encl->va_pages); + + ret = xa_insert(&encl->page_array, PFN_DOWN(encl_page->desc), + encl_page, GFP_KERNEL); + /* + * If ret == -EBUSY then page was created in another flow while + * running without encl->lock + */ + if (ret) + goto err_out_shrink; + + pginfo.secs = (unsigned long)sgx_get_epc_virt_addr(encl->secs.epc_page); + pginfo.addr = encl_page->desc & PAGE_MASK; + pginfo.metadata = 0; + + ret = __eaug(&pginfo, sgx_get_epc_virt_addr(epc_page)); + if (ret) + goto err_out; + + encl_page->encl = encl; + encl_page->epc_page = epc_page; + encl_page->type = SGX_PAGE_TYPE_REG; + encl->secs_child_cnt++; + + sgx_mark_page_reclaimable(encl_page->epc_page); + + phys_addr = sgx_get_epc_phys_addr(epc_page); + /* + * Do not undo everything when creating PTE entry fails - next #PF + * would find page ready for a PTE. + */ + vmret = vmf_insert_pfn(vma, addr, PFN_DOWN(phys_addr)); + if (vmret != VM_FAULT_NOPAGE) { + mutex_unlock(&encl->lock); + return VM_FAULT_SIGBUS; + } + mutex_unlock(&encl->lock); + return VM_FAULT_NOPAGE; + +err_out: + xa_erase(&encl->page_array, PFN_DOWN(encl_page->desc)); + +err_out_shrink: + sgx_encl_shrink(encl, va_page); +err_out_epc: + sgx_encl_free_epc_page(epc_page); +err_out_unlock: + mutex_unlock(&encl->lock); + kfree(encl_page); + + return vmret; +} + static vm_fault_t sgx_vma_fault(struct vm_fault *vmf) { unsigned long addr = (unsigned long)vmf->address; @@ -295,9 +420,20 @@ static vm_fault_t sgx_vma_fault(struct vm_fault *vmf) if (unlikely(!encl)) return VM_FAULT_SIGBUS; + /* + * The page_array keeps track of all enclave pages, whether they + * are swapped out or not. If there is no entry for this page and + * the system supports SGX2 then it is possible to dynamically add + * a new enclave page. This is only possible for an initialized + * enclave that will be checked for right away. + */ + if (cpu_feature_enabled(X86_FEATURE_SGX2) && + (!xa_load(&encl->page_array, PFN_DOWN(addr)))) + return sgx_encl_eaug_page(vma, encl, addr); + mutex_lock(&encl->lock); - entry = sgx_encl_load_page(encl, addr, vma->vm_flags); + entry = sgx_encl_load_page_in_vma(encl, addr, vma->vm_flags); if (IS_ERR(entry)) { mutex_unlock(&encl->lock); @@ -367,6 +503,11 @@ int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start, XA_STATE(xas, &encl->page_array, PFN_DOWN(start)); + /* Disallow mapping outside enclave's address range. */ + if (test_bit(SGX_ENCL_INITIALIZED, &encl->flags) && + (start < encl->base || end > encl->base + encl->size)) + return -EACCES; + /* * Disallow READ_IMPLIES_EXEC tasks as their VMA permissions might * conflict with the enclave page permissions. @@ -445,7 +586,7 @@ static struct sgx_encl_page *sgx_encl_reserve_page(struct sgx_encl *encl, for ( ; ; ) { mutex_lock(&encl->lock); - entry = sgx_encl_load_page(encl, addr, vm_flags); + entry = sgx_encl_load_page_in_vma(encl, addr, vm_flags); if (PTR_ERR(entry) != -EBUSY) break; @@ -687,7 +828,7 @@ 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(). */ + /* Pairs with smp_rmb() in sgx_zap_enclave_ptes(). */ smp_wmb(); encl->mm_list_version++; spin_unlock(&encl->mm_lock); @@ -695,6 +836,73 @@ int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm) return 0; } +/** + * sgx_encl_cpumask() - Query which CPUs might be accessing the enclave + * @encl: the enclave + * + * Some SGX functions require that no cached linear-to-physical address + * mappings are present before they can succeed. For example, ENCLS[EWB] + * copies a page from the enclave page cache to regular main memory but + * it fails if it cannot ensure that there are no cached + * linear-to-physical address mappings referring to the page. + * + * SGX hardware flushes all cached linear-to-physical mappings on a CPU + * when an enclave is exited via ENCLU[EEXIT] or an Asynchronous Enclave + * Exit (AEX). Exiting an enclave will thus ensure cached linear-to-physical + * address mappings are cleared but coordination with the tracking done within + * the SGX hardware is needed to support the SGX functions that depend on this + * cache clearing. + * + * When the ENCLS[ETRACK] function is issued on an enclave the hardware + * tracks threads operating inside the enclave at that time. The SGX + * hardware tracking require that all the identified threads must have + * exited the enclave in order to flush the mappings before a function such + * as ENCLS[EWB] will be permitted + * + * The following flow is used to support SGX functions that require that + * no cached linear-to-physical address mappings are present: + * 1) Execute ENCLS[ETRACK] to initiate hardware tracking. + * 2) Use this function (sgx_encl_cpumask()) to query which CPUs might be + * accessing the enclave. + * 3) Send IPI to identified CPUs, kicking them out of the enclave and + * thus flushing all locally cached linear-to-physical address mappings. + * 4) Execute SGX function. + * + * Context: It is required to call this function after ENCLS[ETRACK]. + * This will ensure that if any new mm appears (racing with + * sgx_encl_mm_add()) then the new mm will enter into the + * enclave with fresh linear-to-physical address mappings. + * + * It is required that all IPIs are completed before a new + * ENCLS[ETRACK] is issued so be sure to protect steps 1 to 3 + * of the above flow with the enclave's mutex. + * + * Return: cpumask of CPUs that might be accessing @encl + */ +const cpumask_t *sgx_encl_cpumask(struct sgx_encl *encl) +{ + cpumask_t *cpumask = &encl->cpumask; + struct sgx_encl_mm *encl_mm; + int idx; + + 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 struct page *sgx_encl_get_backing_page(struct sgx_encl *encl, pgoff_t index) { @@ -735,7 +943,6 @@ static int sgx_encl_get_backing(struct sgx_encl *encl, unsigned long page_index, return PTR_ERR(pcmd); } - backing->page_index = page_index; backing->contents = contents; backing->pcmd = pcmd; backing->pcmd_offset = page_pcmd_off & (PAGE_SIZE - 1); @@ -902,8 +1109,85 @@ int sgx_encl_test_and_clear_young(struct mm_struct *mm, return ret; } +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; +} + +/** + * sgx_zap_enclave_ptes() - remove PTEs mapping the address from enclave + * @encl: the enclave + * @addr: page aligned pointer to single page for which PTEs will be removed + * + * Multiple VMAs may have an enclave page mapped. Remove the PTE mapping + * @addr from each VMA. Ensure that page fault handler is ready to handle + * new mappings of @addr before calling this function. + */ +void sgx_zap_enclave_ptes(struct sgx_encl *encl, unsigned long addr) +{ + 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_wmb() 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; + + mmap_read_lock(encl_mm->mm); + + ret = sgx_encl_find(encl_mm->mm, addr, &vma); + if (!ret && encl == vma->vm_private_data) + zap_vma_ptes(vma, addr, PAGE_SIZE); + + mmap_read_unlock(encl_mm->mm); + + mmput_async(encl_mm->mm); + } + + srcu_read_unlock(&encl->srcu, idx); + } while (unlikely(encl->mm_list_version != mm_list_version)); +} + /** * sgx_alloc_va_page() - Allocate a Version Array (VA) page + * @reclaim: Reclaim EPC pages directly if none available. Enclave + * mutex should not be held if this is set. * * Allocate a free EPC page and convert it to a Version Array (VA) page. * @@ -911,12 +1195,12 @@ int sgx_encl_test_and_clear_young(struct mm_struct *mm, * a VA page, * -errno otherwise */ -struct sgx_epc_page *sgx_alloc_va_page(void) +struct sgx_epc_page *sgx_alloc_va_page(bool reclaim) { struct sgx_epc_page *epc_page; int ret; - epc_page = sgx_alloc_epc_page(NULL, true); + epc_page = sgx_alloc_epc_page(NULL, reclaim); if (IS_ERR(epc_page)) return ERR_CAST(epc_page); diff --git a/arch/x86/kernel/cpu/sgx/encl.h b/arch/x86/kernel/cpu/sgx/encl.h index 332ef3568267..a65a952116fd 100644 --- a/arch/x86/kernel/cpu/sgx/encl.h +++ b/arch/x86/kernel/cpu/sgx/encl.h @@ -27,7 +27,8 @@ struct sgx_encl_page { unsigned long desc; - unsigned long vm_max_prot_bits; + unsigned long vm_max_prot_bits:8; + enum sgx_page_type type:16; struct sgx_epc_page *epc_page; struct sgx_encl *encl; struct sgx_va_page *va_page; @@ -78,7 +79,6 @@ struct sgx_va_page { }; struct sgx_backing { - pgoff_t page_index; struct page *contents; struct page *pcmd; unsigned long pcmd_offset; @@ -106,6 +106,7 @@ int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start, bool current_is_ksgxd(void); void sgx_encl_release(struct kref *ref); int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm); +const cpumask_t *sgx_encl_cpumask(struct sgx_encl *encl); int sgx_encl_lookup_backing(struct sgx_encl *encl, unsigned long page_index, struct sgx_backing *backing); int sgx_encl_alloc_backing(struct sgx_encl *encl, unsigned long page_index, @@ -113,11 +114,18 @@ int sgx_encl_alloc_backing(struct sgx_encl *encl, unsigned long page_index, void sgx_encl_put_backing(struct sgx_backing *backing); int sgx_encl_test_and_clear_young(struct mm_struct *mm, struct sgx_encl_page *page); - -struct sgx_epc_page *sgx_alloc_va_page(void); +struct sgx_encl_page *sgx_encl_page_alloc(struct sgx_encl *encl, + unsigned long offset, + u64 secinfo_flags); +void sgx_zap_enclave_ptes(struct sgx_encl *encl, unsigned long addr); +struct sgx_epc_page *sgx_alloc_va_page(bool reclaim); 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); void sgx_encl_free_epc_page(struct sgx_epc_page *page); +struct sgx_encl_page *sgx_encl_load_page(struct sgx_encl *encl, + unsigned long addr); +struct sgx_va_page *sgx_encl_grow(struct sgx_encl *encl, bool reclaim); +void sgx_encl_shrink(struct sgx_encl *encl, struct sgx_va_page *va_page); #endif /* _X86_ENCL_H */ diff --git a/arch/x86/kernel/cpu/sgx/encls.h b/arch/x86/kernel/cpu/sgx/encls.h index fa04a73daf9c..99004b02e2ed 100644 --- a/arch/x86/kernel/cpu/sgx/encls.h +++ b/arch/x86/kernel/cpu/sgx/encls.h @@ -136,57 +136,71 @@ static inline bool encls_failed(int ret) ret; \ }) +/* Initialize an EPC page into an SGX Enclave Control Structure (SECS) page. */ static inline int __ecreate(struct sgx_pageinfo *pginfo, void *secs) { return __encls_2(ECREATE, pginfo, secs); } +/* Hash a 256 byte region of an enclave page to SECS:MRENCLAVE. */ static inline int __eextend(void *secs, void *addr) { return __encls_2(EEXTEND, secs, addr); } +/* + * Associate an EPC page to an enclave either as a REG or TCS page + * populated with the provided data. + */ static inline int __eadd(struct sgx_pageinfo *pginfo, void *addr) { return __encls_2(EADD, pginfo, addr); } +/* Finalize enclave build, initialize enclave for user code execution. */ static inline int __einit(void *sigstruct, void *token, void *secs) { return __encls_ret_3(EINIT, sigstruct, secs, token); } +/* Disassociate EPC page from its enclave and mark it as unused. */ static inline int __eremove(void *addr) { return __encls_ret_1(EREMOVE, addr); } +/* Copy data to an EPC page belonging to a debug enclave. */ static inline int __edbgwr(void *addr, unsigned long *data) { return __encls_2(EDGBWR, *data, addr); } +/* Copy data from an EPC page belonging to a debug enclave. */ static inline int __edbgrd(void *addr, unsigned long *data) { return __encls_1_1(EDGBRD, *data, addr); } +/* Track that software has completed the required TLB address clears. */ static inline int __etrack(void *addr) { return __encls_ret_1(ETRACK, addr); } +/* Load, verify, and unblock an EPC page. */ static inline int __eldu(struct sgx_pageinfo *pginfo, void *addr, void *va) { return __encls_ret_3(ELDU, pginfo, addr, va); } +/* Make EPC page inaccessible to enclave, ready to be written to memory. */ static inline int __eblock(void *addr) { return __encls_ret_1(EBLOCK, addr); } +/* Initialize an EPC page into a Version Array (VA) page. */ static inline int __epa(void *addr) { unsigned long rbx = SGX_PAGE_TYPE_VA; @@ -194,10 +208,29 @@ static inline int __epa(void *addr) return __encls_2(EPA, rbx, addr); } +/* Invalidate an EPC page and write it out to main memory. */ static inline int __ewb(struct sgx_pageinfo *pginfo, void *addr, void *va) { return __encls_ret_3(EWB, pginfo, addr, va); } +/* Restrict the EPCM permissions of an EPC page. */ +static inline int __emodpr(struct sgx_secinfo *secinfo, void *addr) +{ + return __encls_ret_2(EMODPR, secinfo, addr); +} + +/* Change the type of an EPC page. */ +static inline int __emodt(struct sgx_secinfo *secinfo, void *addr) +{ + return __encls_ret_2(EMODT, secinfo, addr); +} + +/* Zero a page of EPC memory and add it to an initialized enclave. */ +static inline int __eaug(struct sgx_pageinfo *pginfo, void *addr) +{ + return __encls_2(EAUG, pginfo, addr); +} + #endif /* _X86_ENCLS_H */ diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c index 83df20e3e633..ebe79d60619f 100644 --- a/arch/x86/kernel/cpu/sgx/ioctl.c +++ b/arch/x86/kernel/cpu/sgx/ioctl.c @@ -17,7 +17,7 @@ #include "encl.h" #include "encls.h" -static struct sgx_va_page *sgx_encl_grow(struct sgx_encl *encl) +struct sgx_va_page *sgx_encl_grow(struct sgx_encl *encl, bool reclaim) { struct sgx_va_page *va_page = NULL; void *err; @@ -30,7 +30,7 @@ static struct sgx_va_page *sgx_encl_grow(struct sgx_encl *encl) if (!va_page) return ERR_PTR(-ENOMEM); - va_page->epc_page = sgx_alloc_va_page(); + va_page->epc_page = sgx_alloc_va_page(reclaim); if (IS_ERR(va_page->epc_page)) { err = ERR_CAST(va_page->epc_page); kfree(va_page); @@ -43,7 +43,7 @@ static struct sgx_va_page *sgx_encl_grow(struct sgx_encl *encl) return va_page; } -static void sgx_encl_shrink(struct sgx_encl *encl, struct sgx_va_page *va_page) +void sgx_encl_shrink(struct sgx_encl *encl, struct sgx_va_page *va_page) { encl->page_cnt--; @@ -64,7 +64,7 @@ static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs) struct file *backing; long ret; - va_page = sgx_encl_grow(encl); + va_page = sgx_encl_grow(encl, true); if (IS_ERR(va_page)) return PTR_ERR(va_page); else if (va_page) @@ -107,6 +107,7 @@ static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs) set_bit(SGX_ENCL_DEBUG, &encl->flags); encl->secs.encl = encl; + encl->secs.type = SGX_PAGE_TYPE_SECS; encl->base = secs->base; encl->size = secs->size; encl->attributes = secs->attributes; @@ -168,38 +169,6 @@ static long sgx_ioc_enclave_create(struct sgx_encl *encl, void __user *arg) return ret; } -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_validate_secinfo(struct sgx_secinfo *secinfo) { u64 perm = secinfo->flags & SGX_SECINFO_PERMISSION_MASK; @@ -306,7 +275,7 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long src, return PTR_ERR(epc_page); } - va_page = sgx_encl_grow(encl); + va_page = sgx_encl_grow(encl, true); if (IS_ERR(va_page)) { ret = PTR_ERR(va_page); goto err_out_free; @@ -344,6 +313,7 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long src, */ encl_page->encl = encl; encl_page->epc_page = epc_page; + encl_page->type = (secinfo->flags & SGX_SECINFO_PAGE_TYPE_MASK) >> 8; encl->secs_child_cnt++; if (flags & SGX_PAGE_MEASURE) { @@ -372,6 +342,26 @@ err_out_free: return ret; } +/* + * Ensure user provided offset and length values are valid for + * an enclave. + */ +static int sgx_validate_offset_length(struct sgx_encl *encl, + unsigned long offset, + unsigned long length) +{ + if (!IS_ALIGNED(offset, PAGE_SIZE)) + return -EINVAL; + + if (!length || !IS_ALIGNED(length, PAGE_SIZE)) + return -EINVAL; + + if (offset + length - PAGE_SIZE >= encl->size) + return -EINVAL; + + return 0; +} + /** * sgx_ioc_enclave_add_pages() - The handler for %SGX_IOC_ENCLAVE_ADD_PAGES * @encl: an enclave pointer @@ -425,14 +415,10 @@ static long sgx_ioc_enclave_add_pages(struct sgx_encl *encl, void __user *arg) if (copy_from_user(&add_arg, arg, sizeof(add_arg))) return -EFAULT; - if (!IS_ALIGNED(add_arg.offset, PAGE_SIZE) || - !IS_ALIGNED(add_arg.src, PAGE_SIZE)) + if (!IS_ALIGNED(add_arg.src, PAGE_SIZE)) return -EINVAL; - if (!add_arg.length || add_arg.length & (PAGE_SIZE - 1)) - return -EINVAL; - - if (add_arg.offset + add_arg.length - PAGE_SIZE >= encl->size) + if (sgx_validate_offset_length(encl, add_arg.offset, add_arg.length)) return -EINVAL; if (copy_from_user(&secinfo, (void __user *)add_arg.secinfo, @@ -674,6 +660,565 @@ static long sgx_ioc_enclave_provision(struct sgx_encl *encl, void __user *arg) return sgx_set_attribute(&encl->attributes_mask, params.fd); } +/* + * Ensure enclave is ready for SGX2 functions. Readiness is checked + * by ensuring the hardware supports SGX2 and the enclave is initialized + * and thus able to handle requests to modify pages within it. + */ +static int sgx_ioc_sgx2_ready(struct sgx_encl *encl) +{ + if (!(cpu_feature_enabled(X86_FEATURE_SGX2))) + return -ENODEV; + + if (!test_bit(SGX_ENCL_INITIALIZED, &encl->flags)) + return -EINVAL; + + return 0; +} + +/* + * Some SGX functions require that no cached linear-to-physical address + * mappings are present before they can succeed. Collaborate with + * hardware via ENCLS[ETRACK] to ensure that all cached + * linear-to-physical address mappings belonging to all threads of + * the enclave are cleared. See sgx_encl_cpumask() for details. + * + * Must be called with enclave's mutex held from the time the + * SGX function requiring that no cached linear-to-physical mappings + * are present is executed until this ETRACK flow is complete. + */ +static int sgx_enclave_etrack(struct sgx_encl *encl) +{ + void *epc_virt; + int ret; + + epc_virt = sgx_get_epc_virt_addr(encl->secs.epc_page); + ret = __etrack(epc_virt); + if (ret) { + /* + * ETRACK only fails when there is an OS issue. For + * example, two consecutive ETRACK was sent without + * completed IPI between. + */ + pr_err_once("ETRACK returned %d (0x%x)", ret, ret); + /* + * Send IPIs to kick CPUs out of the enclave and + * try ETRACK again. + */ + on_each_cpu_mask(sgx_encl_cpumask(encl), sgx_ipi_cb, NULL, 1); + ret = __etrack(epc_virt); + if (ret) { + pr_err_once("ETRACK repeat returned %d (0x%x)", + ret, ret); + return -EFAULT; + } + } + on_each_cpu_mask(sgx_encl_cpumask(encl), sgx_ipi_cb, NULL, 1); + + return 0; +} + +/** + * sgx_enclave_restrict_permissions() - Restrict EPCM permissions + * @encl: Enclave to which the pages belong. + * @modp: Checked parameters from user on which pages need modifying and + * their new permissions. + * + * Return: + * - 0: Success. + * - -errno: Otherwise. + */ +static long +sgx_enclave_restrict_permissions(struct sgx_encl *encl, + struct sgx_enclave_restrict_permissions *modp) +{ + struct sgx_encl_page *entry; + struct sgx_secinfo secinfo; + unsigned long addr; + unsigned long c; + void *epc_virt; + int ret; + + memset(&secinfo, 0, sizeof(secinfo)); + secinfo.flags = modp->permissions & SGX_SECINFO_PERMISSION_MASK; + + for (c = 0 ; c < modp->length; c += PAGE_SIZE) { + addr = encl->base + modp->offset + c; + + sgx_reclaim_direct(); + + mutex_lock(&encl->lock); + + entry = sgx_encl_load_page(encl, addr); + if (IS_ERR(entry)) { + ret = PTR_ERR(entry) == -EBUSY ? -EAGAIN : -EFAULT; + goto out_unlock; + } + + /* + * Changing EPCM permissions is only supported on regular + * SGX pages. Attempting this change on other pages will + * result in #PF. + */ + if (entry->type != SGX_PAGE_TYPE_REG) { + ret = -EINVAL; + goto out_unlock; + } + + /* + * Apart from ensuring that read-access remains, do not verify + * the permission bits requested. Kernel has no control over + * how EPCM permissions can be relaxed from within the enclave. + * ENCLS[EMODPR] can only remove existing EPCM permissions, + * attempting to set new permissions will be ignored by the + * hardware. + */ + + /* Change EPCM permissions. */ + epc_virt = sgx_get_epc_virt_addr(entry->epc_page); + ret = __emodpr(&secinfo, epc_virt); + if (encls_faulted(ret)) { + /* + * All possible faults should be avoidable: + * parameters have been checked, will only change + * permissions of a regular page, and no concurrent + * SGX1/SGX2 ENCLS instructions since these + * are protected with mutex. + */ + pr_err_once("EMODPR encountered exception %d\n", + ENCLS_TRAPNR(ret)); + ret = -EFAULT; + goto out_unlock; + } + if (encls_failed(ret)) { + modp->result = ret; + ret = -EFAULT; + goto out_unlock; + } + + ret = sgx_enclave_etrack(encl); + if (ret) { + ret = -EFAULT; + goto out_unlock; + } + + mutex_unlock(&encl->lock); + } + + ret = 0; + goto out; + +out_unlock: + mutex_unlock(&encl->lock); +out: + modp->count = c; + + return ret; +} + +/** + * sgx_ioc_enclave_restrict_permissions() - handler for + * %SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS + * @encl: an enclave pointer + * @arg: userspace pointer to a &struct sgx_enclave_restrict_permissions + * instance + * + * SGX2 distinguishes between relaxing and restricting the enclave page + * permissions maintained by the hardware (EPCM permissions) of pages + * belonging to an initialized enclave (after SGX_IOC_ENCLAVE_INIT). + * + * EPCM permissions cannot be restricted from within the enclave, the enclave + * requires the kernel to run the privileged level 0 instructions ENCLS[EMODPR] + * and ENCLS[ETRACK]. An attempt to relax EPCM permissions with this call + * will be ignored by the hardware. + * + * Return: + * - 0: Success + * - -errno: Otherwise + */ +static long sgx_ioc_enclave_restrict_permissions(struct sgx_encl *encl, + void __user *arg) +{ + struct sgx_enclave_restrict_permissions params; + long ret; + + ret = sgx_ioc_sgx2_ready(encl); + if (ret) + return ret; + + if (copy_from_user(¶ms, arg, sizeof(params))) + return -EFAULT; + + if (sgx_validate_offset_length(encl, params.offset, params.length)) + return -EINVAL; + + if (params.permissions & ~SGX_SECINFO_PERMISSION_MASK) + return -EINVAL; + + /* + * Fail early if invalid permissions requested to prevent ENCLS[EMODPR] + * from faulting later when the CPU does the same check. + */ + if ((params.permissions & SGX_SECINFO_W) && + !(params.permissions & SGX_SECINFO_R)) + return -EINVAL; + + if (params.result || params.count) + return -EINVAL; + + ret = sgx_enclave_restrict_permissions(encl, ¶ms); + + if (copy_to_user(arg, ¶ms, sizeof(params))) + return -EFAULT; + + return ret; +} + +/** + * sgx_enclave_modify_types() - Modify type of SGX enclave pages + * @encl: Enclave to which the pages belong. + * @modt: Checked parameters from user about which pages need modifying + * and their new page type. + * + * Return: + * - 0: Success + * - -errno: Otherwise + */ +static long sgx_enclave_modify_types(struct sgx_encl *encl, + struct sgx_enclave_modify_types *modt) +{ + unsigned long max_prot_restore; + enum sgx_page_type page_type; + struct sgx_encl_page *entry; + struct sgx_secinfo secinfo; + unsigned long prot; + unsigned long addr; + unsigned long c; + void *epc_virt; + int ret; + + page_type = modt->page_type & SGX_PAGE_TYPE_MASK; + + /* + * The only new page types allowed by hardware are PT_TCS and PT_TRIM. + */ + if (page_type != SGX_PAGE_TYPE_TCS && page_type != SGX_PAGE_TYPE_TRIM) + return -EINVAL; + + memset(&secinfo, 0, sizeof(secinfo)); + + secinfo.flags = page_type << 8; + + for (c = 0 ; c < modt->length; c += PAGE_SIZE) { + addr = encl->base + modt->offset + c; + + sgx_reclaim_direct(); + + mutex_lock(&encl->lock); + + entry = sgx_encl_load_page(encl, addr); + if (IS_ERR(entry)) { + ret = PTR_ERR(entry) == -EBUSY ? -EAGAIN : -EFAULT; + goto out_unlock; + } + + /* + * Borrow the logic from the Intel SDM. Regular pages + * (SGX_PAGE_TYPE_REG) can change type to SGX_PAGE_TYPE_TCS + * or SGX_PAGE_TYPE_TRIM but TCS pages can only be trimmed. + * CET pages not supported yet. + */ + if (!(entry->type == SGX_PAGE_TYPE_REG || + (entry->type == SGX_PAGE_TYPE_TCS && + page_type == SGX_PAGE_TYPE_TRIM))) { + ret = -EINVAL; + goto out_unlock; + } + + max_prot_restore = entry->vm_max_prot_bits; + + /* + * Once a regular page becomes a TCS page it cannot be + * changed back. So the maximum allowed protection reflects + * the TCS page that is always RW from kernel perspective but + * will be inaccessible from within enclave. Before doing + * so, do make sure that the new page type continues to + * respect the originally vetted page permissions. + */ + if (entry->type == SGX_PAGE_TYPE_REG && + page_type == SGX_PAGE_TYPE_TCS) { + if (~entry->vm_max_prot_bits & (VM_READ | VM_WRITE)) { + ret = -EPERM; + goto out_unlock; + } + prot = PROT_READ | PROT_WRITE; + entry->vm_max_prot_bits = calc_vm_prot_bits(prot, 0); + + /* + * Prevent page from being reclaimed while mutex + * is released. + */ + if (sgx_unmark_page_reclaimable(entry->epc_page)) { + ret = -EAGAIN; + goto out_entry_changed; + } + + /* + * Do not keep encl->lock because of dependency on + * mmap_lock acquired in sgx_zap_enclave_ptes(). + */ + mutex_unlock(&encl->lock); + + sgx_zap_enclave_ptes(encl, addr); + + mutex_lock(&encl->lock); + + sgx_mark_page_reclaimable(entry->epc_page); + } + + /* Change EPC type */ + epc_virt = sgx_get_epc_virt_addr(entry->epc_page); + ret = __emodt(&secinfo, epc_virt); + if (encls_faulted(ret)) { + /* + * All possible faults should be avoidable: + * parameters have been checked, will only change + * valid page types, and no concurrent + * SGX1/SGX2 ENCLS instructions since these are + * protected with mutex. + */ + pr_err_once("EMODT encountered exception %d\n", + ENCLS_TRAPNR(ret)); + ret = -EFAULT; + goto out_entry_changed; + } + if (encls_failed(ret)) { + modt->result = ret; + ret = -EFAULT; + goto out_entry_changed; + } + + ret = sgx_enclave_etrack(encl); + if (ret) { + ret = -EFAULT; + goto out_unlock; + } + + entry->type = page_type; + + mutex_unlock(&encl->lock); + } + + ret = 0; + goto out; + +out_entry_changed: + entry->vm_max_prot_bits = max_prot_restore; +out_unlock: + mutex_unlock(&encl->lock); +out: + modt->count = c; + + return ret; +} + +/** + * sgx_ioc_enclave_modify_types() - handler for %SGX_IOC_ENCLAVE_MODIFY_TYPES + * @encl: an enclave pointer + * @arg: userspace pointer to a &struct sgx_enclave_modify_types instance + * + * Ability to change the enclave page type supports the following use cases: + * + * * It is possible to add TCS pages to an enclave by changing the type of + * regular pages (%SGX_PAGE_TYPE_REG) to TCS (%SGX_PAGE_TYPE_TCS) pages. + * With this support the number of threads supported by an initialized + * enclave can be increased dynamically. + * + * * Regular or TCS pages can dynamically be removed from an initialized + * enclave by changing the page type to %SGX_PAGE_TYPE_TRIM. Changing the + * page type to %SGX_PAGE_TYPE_TRIM marks the page for removal with actual + * removal done by handler of %SGX_IOC_ENCLAVE_REMOVE_PAGES ioctl() called + * after ENCLU[EACCEPT] is run on %SGX_PAGE_TYPE_TRIM page from within the + * enclave. + * + * Return: + * - 0: Success + * - -errno: Otherwise + */ +static long sgx_ioc_enclave_modify_types(struct sgx_encl *encl, + void __user *arg) +{ + struct sgx_enclave_modify_types params; + long ret; + + ret = sgx_ioc_sgx2_ready(encl); + if (ret) + return ret; + + if (copy_from_user(¶ms, arg, sizeof(params))) + return -EFAULT; + + if (sgx_validate_offset_length(encl, params.offset, params.length)) + return -EINVAL; + + if (params.page_type & ~SGX_PAGE_TYPE_MASK) + return -EINVAL; + + if (params.result || params.count) + return -EINVAL; + + ret = sgx_enclave_modify_types(encl, ¶ms); + + if (copy_to_user(arg, ¶ms, sizeof(params))) + return -EFAULT; + + return ret; +} + +/** + * sgx_encl_remove_pages() - Remove trimmed pages from SGX enclave + * @encl: Enclave to which the pages belong + * @params: Checked parameters from user on which pages need to be removed + * + * Return: + * - 0: Success. + * - -errno: Otherwise. + */ +static long sgx_encl_remove_pages(struct sgx_encl *encl, + struct sgx_enclave_remove_pages *params) +{ + struct sgx_encl_page *entry; + struct sgx_secinfo secinfo; + unsigned long addr; + unsigned long c; + void *epc_virt; + int ret; + + memset(&secinfo, 0, sizeof(secinfo)); + secinfo.flags = SGX_SECINFO_R | SGX_SECINFO_W | SGX_SECINFO_X; + + for (c = 0 ; c < params->length; c += PAGE_SIZE) { + addr = encl->base + params->offset + c; + + sgx_reclaim_direct(); + + mutex_lock(&encl->lock); + + entry = sgx_encl_load_page(encl, addr); + if (IS_ERR(entry)) { + ret = PTR_ERR(entry) == -EBUSY ? -EAGAIN : -EFAULT; + goto out_unlock; + } + + if (entry->type != SGX_PAGE_TYPE_TRIM) { + ret = -EPERM; + goto out_unlock; + } + + /* + * ENCLS[EMODPR] is a no-op instruction used to inform if + * ENCLU[EACCEPT] was run from within the enclave. If + * ENCLS[EMODPR] is run with RWX on a trimmed page that is + * not yet accepted then it will return + * %SGX_PAGE_NOT_MODIFIABLE, after the trimmed page is + * accepted the instruction will encounter a page fault. + */ + epc_virt = sgx_get_epc_virt_addr(entry->epc_page); + ret = __emodpr(&secinfo, epc_virt); + if (!encls_faulted(ret) || ENCLS_TRAPNR(ret) != X86_TRAP_PF) { + ret = -EPERM; + goto out_unlock; + } + + if (sgx_unmark_page_reclaimable(entry->epc_page)) { + ret = -EBUSY; + goto out_unlock; + } + + /* + * Do not keep encl->lock because of dependency on + * mmap_lock acquired in sgx_zap_enclave_ptes(). + */ + mutex_unlock(&encl->lock); + + sgx_zap_enclave_ptes(encl, addr); + + mutex_lock(&encl->lock); + + sgx_encl_free_epc_page(entry->epc_page); + encl->secs_child_cnt--; + entry->epc_page = NULL; + xa_erase(&encl->page_array, PFN_DOWN(entry->desc)); + sgx_encl_shrink(encl, NULL); + kfree(entry); + + mutex_unlock(&encl->lock); + } + + ret = 0; + goto out; + +out_unlock: + mutex_unlock(&encl->lock); +out: + params->count = c; + + return ret; +} + +/** + * sgx_ioc_enclave_remove_pages() - handler for %SGX_IOC_ENCLAVE_REMOVE_PAGES + * @encl: an enclave pointer + * @arg: userspace pointer to &struct sgx_enclave_remove_pages instance + * + * Final step of the flow removing pages from an initialized enclave. The + * complete flow is: + * + * 1) User changes the type of the pages to be removed to %SGX_PAGE_TYPE_TRIM + * using the %SGX_IOC_ENCLAVE_MODIFY_TYPES ioctl(). + * 2) User approves the page removal by running ENCLU[EACCEPT] from within + * the enclave. + * 3) User initiates actual page removal using the + * %SGX_IOC_ENCLAVE_REMOVE_PAGES ioctl() that is handled here. + * + * First remove any page table entries pointing to the page and then proceed + * with the actual removal of the enclave page and data in support of it. + * + * VA pages are not affected by this removal. It is thus possible that the + * enclave may end up with more VA pages than needed to support all its + * pages. + * + * Return: + * - 0: Success + * - -errno: Otherwise + */ +static long sgx_ioc_enclave_remove_pages(struct sgx_encl *encl, + void __user *arg) +{ + struct sgx_enclave_remove_pages params; + long ret; + + ret = sgx_ioc_sgx2_ready(encl); + if (ret) + return ret; + + if (copy_from_user(¶ms, arg, sizeof(params))) + return -EFAULT; + + if (sgx_validate_offset_length(encl, params.offset, params.length)) + return -EINVAL; + + if (params.count) + return -EINVAL; + + ret = sgx_encl_remove_pages(encl, ¶ms); + + if (copy_to_user(arg, ¶ms, sizeof(params))) + return -EFAULT; + + return ret; +} + long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) { struct sgx_encl *encl = filep->private_data; @@ -695,6 +1240,16 @@ long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) case SGX_IOC_ENCLAVE_PROVISION: ret = sgx_ioc_enclave_provision(encl, (void __user *)arg); break; + case SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS: + ret = sgx_ioc_enclave_restrict_permissions(encl, + (void __user *)arg); + break; + case SGX_IOC_ENCLAVE_MODIFY_TYPES: + ret = sgx_ioc_enclave_modify_types(encl, (void __user *)arg); + break; + case SGX_IOC_ENCLAVE_REMOVE_PAGES: + ret = sgx_ioc_enclave_remove_pages(encl, (void __user *)arg); + break; default: ret = -ENOIOCTLCMD; break; diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index a78652d43e61..515e2a5f25bb 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -137,36 +137,9 @@ static void sgx_reclaimer_block(struct sgx_epc_page *epc_page) struct sgx_encl_page *page = epc_page->owner; unsigned long addr = page->desc & PAGE_MASK; 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; + int 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; - - mmap_read_lock(encl_mm->mm); - - ret = sgx_encl_find(encl_mm->mm, addr, &vma); - if (!ret && encl == vma->vm_private_data) - zap_vma_ptes(vma, addr, PAGE_SIZE); - - mmap_read_unlock(encl_mm->mm); - - mmput_async(encl_mm->mm); - } - - srcu_read_unlock(&encl->srcu, idx); - } while (unlikely(encl->mm_list_version != mm_list_version)); + sgx_zap_enclave_ptes(encl, addr); mutex_lock(&encl->lock); @@ -201,39 +174,10 @@ static int __sgx_encl_ewb(struct sgx_epc_page *epc_page, void *va_slot, return ret; } -static void sgx_ipi_cb(void *info) +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; -} - /* * Swap page to the regular memory transformed to the blocked state by using * EBLOCK, which means that it can no longer be referenced (no new TLB entries). @@ -280,7 +224,7 @@ static void sgx_encl_ewb(struct sgx_epc_page *epc_page, * miss cpus that entered the enclave between * generating the mask and incrementing epoch. */ - on_each_cpu_mask(sgx_encl_ewb_cpumask(encl), + on_each_cpu_mask(sgx_encl_cpumask(encl), sgx_ipi_cb, NULL, 1); ret = __sgx_encl_ewb(epc_page, va_slot, backing); } @@ -431,6 +375,17 @@ static bool sgx_should_reclaim(unsigned long watermark) !list_empty(&sgx_active_page_list); } +/* + * sgx_reclaim_direct() should be called (without enclave's mutex held) + * in locations where SGX memory resources might be low and might be + * needed in order to make forward progress. + */ +void sgx_reclaim_direct(void) +{ + if (sgx_should_reclaim(SGX_NR_LOW_PAGES)) + sgx_reclaim_pages(); +} + static int ksgxd(void *p) { set_freezable(); diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index 0f17def9fe6f..0f2020653fba 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -86,10 +86,13 @@ static inline void *sgx_get_epc_virt_addr(struct sgx_epc_page *page) struct sgx_epc_page *__sgx_alloc_epc_page(void); void sgx_free_epc_page(struct sgx_epc_page *page); +void sgx_reclaim_direct(void); void sgx_mark_page_reclaimable(struct sgx_epc_page *page); int sgx_unmark_page_reclaimable(struct sgx_epc_page *page); struct sgx_epc_page *sgx_alloc_epc_page(void *owner, bool reclaim); +void sgx_ipi_cb(void *info); + #ifdef CONFIG_X86_SGX_KVM int __init sgx_vepc_init(void); #else diff --git a/tools/testing/selftests/sgx/defines.h b/tools/testing/selftests/sgx/defines.h index 02d775789ea7..d8587c971941 100644 --- a/tools/testing/selftests/sgx/defines.h +++ b/tools/testing/selftests/sgx/defines.h @@ -24,6 +24,9 @@ enum encl_op_type { ENCL_OP_PUT_TO_ADDRESS, ENCL_OP_GET_FROM_ADDRESS, ENCL_OP_NOP, + ENCL_OP_EACCEPT, + ENCL_OP_EMODPE, + ENCL_OP_INIT_TCS_PAGE, ENCL_OP_MAX, }; @@ -53,4 +56,24 @@ struct encl_op_get_from_addr { uint64_t addr; }; +struct encl_op_eaccept { + struct encl_op_header header; + uint64_t epc_addr; + uint64_t flags; + uint64_t ret; +}; + +struct encl_op_emodpe { + struct encl_op_header header; + uint64_t epc_addr; + uint64_t flags; +}; + +struct encl_op_init_tcs_page { + struct encl_op_header header; + uint64_t tcs_page; + uint64_t ssa; + uint64_t entry; +}; + #endif /* DEFINES_H */ diff --git a/tools/testing/selftests/sgx/load.c b/tools/testing/selftests/sgx/load.c index 006b464c8fc9..94bdeac1cf04 100644 --- a/tools/testing/selftests/sgx/load.c +++ b/tools/testing/selftests/sgx/load.c @@ -130,6 +130,47 @@ static bool encl_ioc_add_pages(struct encl *encl, struct encl_segment *seg) return true; } +/* + * Parse the enclave code's symbol table to locate and return address of + * the provided symbol + */ +uint64_t encl_get_entry(struct encl *encl, const char *symbol) +{ + Elf64_Shdr *sections; + Elf64_Sym *symtab; + Elf64_Ehdr *ehdr; + char *sym_names; + int num_sym; + int i; + + ehdr = encl->bin; + sections = encl->bin + ehdr->e_shoff; + + for (i = 0; i < ehdr->e_shnum; i++) { + if (sections[i].sh_type == SHT_SYMTAB) { + symtab = (Elf64_Sym *)((char *)encl->bin + sections[i].sh_offset); + num_sym = sections[i].sh_size / sections[i].sh_entsize; + break; + } + } + + for (i = 0; i < ehdr->e_shnum; i++) { + if (sections[i].sh_type == SHT_STRTAB) { + sym_names = (char *)encl->bin + sections[i].sh_offset; + break; + } + } + + for (i = 0; i < num_sym; i++) { + Elf64_Sym *sym = &symtab[i]; + + if (!strcmp(symbol, sym_names + sym->st_name)) + return (uint64_t)sym->st_value; + } + + return 0; +} + bool encl_load(const char *path, struct encl *encl, unsigned long heap_size) { const char device_path[] = "/dev/sgx_enclave"; diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c index dd74fa42302e..9820b3809c69 100644 --- a/tools/testing/selftests/sgx/main.c +++ b/tools/testing/selftests/sgx/main.c @@ -25,6 +25,18 @@ static const uint64_t MAGIC = 0x1122334455667788ULL; static const uint64_t MAGIC2 = 0x8877665544332211ULL; vdso_sgx_enter_enclave_t vdso_sgx_enter_enclave; +/* + * Security Information (SECINFO) data structure needed by a few SGX + * instructions (eg. ENCLU[EACCEPT] and ENCLU[EMODPE]) holds meta-data + * about an enclave page. &enum sgx_secinfo_page_state specifies the + * secinfo flags used for page state. + */ +enum sgx_secinfo_page_state { + SGX_SECINFO_PENDING = (1 << 3), + SGX_SECINFO_MODIFIED = (1 << 4), + SGX_SECINFO_PR = (1 << 5), +}; + struct vdso_symtab { Elf64_Sym *elf_symtab; const char *elf_symstrtab; @@ -74,6 +86,15 @@ static bool vdso_get_symtab(void *addr, struct vdso_symtab *symtab) return true; } +static inline int sgx2_supported(void) +{ + unsigned int eax, ebx, ecx, edx; + + __cpuid_count(SGX_CPUID, 0x0, eax, ebx, ecx, edx); + + return eax & 0x2; +} + static unsigned long elf_sym_hash(const char *name) { unsigned long h = 0, high; @@ -109,6 +130,24 @@ static Elf64_Sym *vdso_symtab_get(struct vdso_symtab *symtab, const char *name) return NULL; } +/* + * Return the offset in the enclave where the TCS segment can be found. + * The first RW segment loaded is the TCS. + */ +static off_t encl_get_tcs_offset(struct encl *encl) +{ + int i; + + for (i = 0; i < encl->nr_segments; i++) { + struct encl_segment *seg = &encl->segment_tbl[i]; + + if (i == 0 && seg->prot == (PROT_READ | PROT_WRITE)) + return seg->offset; + } + + return -1; +} + /* * Return the offset in the enclave where the data segment can be found. * The first RW segment loaded is the TCS, skip that to get info on the @@ -339,7 +378,127 @@ TEST_F(enclave, unclobbered_vdso_oversubscribed) EXPECT_EQ(get_op.value, MAGIC); EXPECT_EEXIT(&self->run); EXPECT_EQ(self->run.user_data, 0); +} +TEST_F_TIMEOUT(enclave, unclobbered_vdso_oversubscribed_remove, 900) +{ + struct sgx_enclave_remove_pages remove_ioc; + struct sgx_enclave_modify_types modt_ioc; + struct encl_op_get_from_buf get_op; + struct encl_op_eaccept eaccept_op; + struct encl_op_put_to_buf put_op; + struct encl_segment *heap; + unsigned long total_mem; + int ret, errno_save; + unsigned long addr; + unsigned long i; + + /* + * Create enclave with additional heap that is as big as all + * available physical SGX memory. + */ + total_mem = get_total_epc_mem(); + ASSERT_NE(total_mem, 0); + TH_LOG("Creating an enclave with %lu bytes heap may take a while ...", + total_mem); + ASSERT_TRUE(setup_test_encl(total_mem, &self->encl, _metadata)); + + /* + * Hardware (SGX2) and kernel support is needed for this test. Start + * with check that test has a chance of succeeding. + */ + memset(&modt_ioc, 0, sizeof(modt_ioc)); + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &modt_ioc); + + if (ret == -1) { + if (errno == ENOTTY) + SKIP(return, + "Kernel does not support SGX_IOC_ENCLAVE_MODIFY_TYPES ioctl()"); + else if (errno == ENODEV) + SKIP(return, "System does not support SGX2"); + } + + /* + * Invalid parameters were provided during sanity check, + * expect command to fail. + */ + EXPECT_EQ(ret, -1); + + /* SGX2 is supported by kernel and hardware, test can proceed. */ + memset(&self->run, 0, sizeof(self->run)); + self->run.tcs = self->encl.encl_base; + + heap = &self->encl.segment_tbl[self->encl.nr_segments - 1]; + + put_op.header.type = ENCL_OP_PUT_TO_BUFFER; + put_op.value = MAGIC; + + EXPECT_EQ(ENCL_CALL(&put_op, &self->run, false), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.user_data, 0); + + get_op.header.type = ENCL_OP_GET_FROM_BUFFER; + get_op.value = 0; + + EXPECT_EQ(ENCL_CALL(&get_op, &self->run, false), 0); + + EXPECT_EQ(get_op.value, MAGIC); + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.user_data, 0); + + /* Trim entire heap. */ + memset(&modt_ioc, 0, sizeof(modt_ioc)); + + modt_ioc.offset = heap->offset; + modt_ioc.length = heap->size; + modt_ioc.page_type = SGX_PAGE_TYPE_TRIM; + + TH_LOG("Changing type of %zd bytes to trimmed may take a while ...", + heap->size); + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &modt_ioc); + errno_save = ret == -1 ? errno : 0; + + EXPECT_EQ(ret, 0); + EXPECT_EQ(errno_save, 0); + EXPECT_EQ(modt_ioc.result, 0); + EXPECT_EQ(modt_ioc.count, heap->size); + + /* EACCEPT all removed pages. */ + addr = self->encl.encl_base + heap->offset; + + eaccept_op.flags = SGX_SECINFO_TRIM | SGX_SECINFO_MODIFIED; + eaccept_op.header.type = ENCL_OP_EACCEPT; + + TH_LOG("Entering enclave to run EACCEPT for each page of %zd bytes may take a while ...", + heap->size); + for (i = 0; i < heap->size; i += 4096) { + eaccept_op.epc_addr = addr + i; + eaccept_op.ret = 0; + + EXPECT_EQ(ENCL_CALL(&eaccept_op, &self->run, true), 0); + + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + ASSERT_EQ(eaccept_op.ret, 0); + ASSERT_EQ(self->run.function, EEXIT); + } + + /* Complete page removal. */ + memset(&remove_ioc, 0, sizeof(remove_ioc)); + + remove_ioc.offset = heap->offset; + remove_ioc.length = heap->size; + + TH_LOG("Removing %zd bytes from enclave may take a while ...", + heap->size); + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_REMOVE_PAGES, &remove_ioc); + errno_save = ret == -1 ? errno : 0; + + EXPECT_EQ(ret, 0); + EXPECT_EQ(errno_save, 0); + EXPECT_EQ(remove_ioc.count, heap->size); } TEST_F(enclave, clobbered_vdso) @@ -555,4 +714,1280 @@ TEST_F(enclave, pte_permissions) EXPECT_EQ(self->run.exception_addr, 0); } +/* + * Modifying permissions of TCS page should not be possible. + */ +TEST_F(enclave, tcs_permissions) +{ + struct sgx_enclave_restrict_permissions ioc; + int ret, errno_save; + + ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata)); + + memset(&self->run, 0, sizeof(self->run)); + self->run.tcs = self->encl.encl_base; + + memset(&ioc, 0, sizeof(ioc)); + + /* + * Ensure kernel supports needed ioctl() and system supports needed + * commands. + */ + + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS, &ioc); + errno_save = ret == -1 ? errno : 0; + + /* + * Invalid parameters were provided during sanity check, + * expect command to fail. + */ + ASSERT_EQ(ret, -1); + + /* ret == -1 */ + if (errno_save == ENOTTY) + SKIP(return, + "Kernel does not support SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS ioctl()"); + else if (errno_save == ENODEV) + SKIP(return, "System does not support SGX2"); + + /* + * Attempt to make TCS page read-only. This is not allowed and + * should be prevented by the kernel. + */ + ioc.offset = encl_get_tcs_offset(&self->encl); + ioc.length = PAGE_SIZE; + ioc.permissions = SGX_SECINFO_R; + + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS, &ioc); + errno_save = ret == -1 ? errno : 0; + + EXPECT_EQ(ret, -1); + EXPECT_EQ(errno_save, EINVAL); + EXPECT_EQ(ioc.result, 0); + EXPECT_EQ(ioc.count, 0); +} + +/* + * Enclave page permission test. + * + * Modify and restore enclave page's EPCM (enclave) permissions from + * outside enclave (ENCLS[EMODPR] via kernel) as well as from within + * enclave (via ENCLU[EMODPE]). Check for page fault if + * VMA allows access but EPCM permissions do not. + */ +TEST_F(enclave, epcm_permissions) +{ + struct sgx_enclave_restrict_permissions restrict_ioc; + struct encl_op_get_from_addr get_addr_op; + struct encl_op_put_to_addr put_addr_op; + struct encl_op_eaccept eaccept_op; + struct encl_op_emodpe emodpe_op; + unsigned long data_start; + int ret, errno_save; + + ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata)); + + memset(&self->run, 0, sizeof(self->run)); + self->run.tcs = self->encl.encl_base; + + /* + * Ensure kernel supports needed ioctl() and system supports needed + * commands. + */ + memset(&restrict_ioc, 0, sizeof(restrict_ioc)); + + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS, + &restrict_ioc); + errno_save = ret == -1 ? errno : 0; + + /* + * Invalid parameters were provided during sanity check, + * expect command to fail. + */ + ASSERT_EQ(ret, -1); + + /* ret == -1 */ + if (errno_save == ENOTTY) + SKIP(return, + "Kernel does not support SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS ioctl()"); + else if (errno_save == ENODEV) + SKIP(return, "System does not support SGX2"); + + /* + * Page that will have its permissions changed is the second data + * page in the .data segment. This forms part of the local encl_buffer + * within the enclave. + * + * At start of test @data_start should have EPCM as well as PTE and + * VMA permissions of RW. + */ + + data_start = self->encl.encl_base + + encl_get_data_offset(&self->encl) + PAGE_SIZE; + + /* + * Sanity check that page at @data_start is writable before making + * any changes to page permissions. + * + * Start by writing MAGIC to test page. + */ + put_addr_op.value = MAGIC; + put_addr_op.addr = data_start; + put_addr_op.header.type = ENCL_OP_PUT_TO_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&put_addr_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* + * Read memory that was just written to, confirming that + * page is writable. + */ + get_addr_op.value = 0; + get_addr_op.addr = data_start; + get_addr_op.header.type = ENCL_OP_GET_FROM_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&get_addr_op, &self->run, true), 0); + + EXPECT_EQ(get_addr_op.value, MAGIC); + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* + * Change EPCM permissions to read-only. Kernel still considers + * the page writable. + */ + memset(&restrict_ioc, 0, sizeof(restrict_ioc)); + + restrict_ioc.offset = encl_get_data_offset(&self->encl) + PAGE_SIZE; + restrict_ioc.length = PAGE_SIZE; + restrict_ioc.permissions = SGX_SECINFO_R; + + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS, + &restrict_ioc); + errno_save = ret == -1 ? errno : 0; + + EXPECT_EQ(ret, 0); + EXPECT_EQ(errno_save, 0); + EXPECT_EQ(restrict_ioc.result, 0); + EXPECT_EQ(restrict_ioc.count, 4096); + + /* + * EPCM permissions changed from kernel, need to EACCEPT from enclave. + */ + eaccept_op.epc_addr = data_start; + eaccept_op.flags = SGX_SECINFO_R | SGX_SECINFO_REG | SGX_SECINFO_PR; + eaccept_op.ret = 0; + eaccept_op.header.type = ENCL_OP_EACCEPT; + + EXPECT_EQ(ENCL_CALL(&eaccept_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + EXPECT_EQ(eaccept_op.ret, 0); + + /* + * EPCM permissions of page is now read-only, expect #PF + * on EPCM when attempting to write to page from within enclave. + */ + put_addr_op.value = MAGIC2; + + EXPECT_EQ(ENCL_CALL(&put_addr_op, &self->run, true), 0); + + EXPECT_EQ(self->run.function, ERESUME); + EXPECT_EQ(self->run.exception_vector, 14); + EXPECT_EQ(self->run.exception_error_code, 0x8007); + EXPECT_EQ(self->run.exception_addr, data_start); + + self->run.exception_vector = 0; + self->run.exception_error_code = 0; + self->run.exception_addr = 0; + + /* + * Received AEX but cannot return to enclave at same entrypoint, + * need different TCS from where EPCM permission can be made writable + * again. + */ + self->run.tcs = self->encl.encl_base + PAGE_SIZE; + + /* + * Enter enclave at new TCS to change EPCM permissions to be + * writable again and thus fix the page fault that triggered the + * AEX. + */ + + emodpe_op.epc_addr = data_start; + emodpe_op.flags = SGX_SECINFO_R | SGX_SECINFO_W; + emodpe_op.header.type = ENCL_OP_EMODPE; + + EXPECT_EQ(ENCL_CALL(&emodpe_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* + * Attempt to return to main TCS to resume execution at faulting + * instruction, PTE should continue to allow writing to the page. + */ + self->run.tcs = self->encl.encl_base; + + /* + * Wrong page permissions that caused original fault has + * now been fixed via EPCM permissions. + * Resume execution in main TCS to re-attempt the memory access. + */ + self->run.tcs = self->encl.encl_base; + + EXPECT_EQ(vdso_sgx_enter_enclave((unsigned long)&put_addr_op, 0, 0, + ERESUME, 0, 0, + &self->run), + 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + get_addr_op.value = 0; + + EXPECT_EQ(ENCL_CALL(&get_addr_op, &self->run, true), 0); + + EXPECT_EQ(get_addr_op.value, MAGIC2); + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.user_data, 0); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); +} + +/* + * Test the addition of pages to an initialized enclave via writing to + * a page belonging to the enclave's address space but was not added + * during enclave creation. + */ +TEST_F(enclave, augment) +{ + struct encl_op_get_from_addr get_addr_op; + struct encl_op_put_to_addr put_addr_op; + struct encl_op_eaccept eaccept_op; + size_t total_size = 0; + void *addr; + int i; + + if (!sgx2_supported()) + SKIP(return, "SGX2 not supported"); + + ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata)); + + memset(&self->run, 0, sizeof(self->run)); + self->run.tcs = self->encl.encl_base; + + for (i = 0; i < self->encl.nr_segments; i++) { + struct encl_segment *seg = &self->encl.segment_tbl[i]; + + total_size += seg->size; + } + + /* + * Actual enclave size is expected to be larger than the loaded + * test enclave since enclave size must be a power of 2 in bytes + * and test_encl does not consume it all. + */ + EXPECT_LT(total_size + PAGE_SIZE, self->encl.encl_size); + + /* + * Create memory mapping for the page that will be added. New + * memory mapping is for one page right after all existing + * mappings. + * Kernel will allow new mapping using any permissions if it + * falls into the enclave's address range but not backed + * by existing enclave pages. + */ + addr = mmap((void *)self->encl.encl_base + total_size, PAGE_SIZE, + PROT_READ | PROT_WRITE | PROT_EXEC, + MAP_SHARED | MAP_FIXED, self->encl.fd, 0); + EXPECT_NE(addr, MAP_FAILED); + + self->run.exception_vector = 0; + self->run.exception_error_code = 0; + self->run.exception_addr = 0; + + /* + * Attempt to write to the new page from within enclave. + * Expected to fail since page is not (yet) part of the enclave. + * The first #PF will trigger the addition of the page to the + * enclave, but since the new page needs an EACCEPT from within the + * enclave before it can be used it would not be possible + * to successfully return to the failing instruction. This is the + * cause of the second #PF captured here having the SGX bit set, + * it is from hardware preventing the page from being used. + */ + put_addr_op.value = MAGIC; + put_addr_op.addr = (unsigned long)addr; + put_addr_op.header.type = ENCL_OP_PUT_TO_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&put_addr_op, &self->run, true), 0); + + EXPECT_EQ(self->run.function, ERESUME); + EXPECT_EQ(self->run.exception_vector, 14); + EXPECT_EQ(self->run.exception_addr, (unsigned long)addr); + + if (self->run.exception_error_code == 0x6) { + munmap(addr, PAGE_SIZE); + SKIP(return, "Kernel does not support adding pages to initialized enclave"); + } + + EXPECT_EQ(self->run.exception_error_code, 0x8007); + + self->run.exception_vector = 0; + self->run.exception_error_code = 0; + self->run.exception_addr = 0; + + /* Handle AEX by running EACCEPT from new entry point. */ + self->run.tcs = self->encl.encl_base + PAGE_SIZE; + + eaccept_op.epc_addr = self->encl.encl_base + total_size; + eaccept_op.flags = SGX_SECINFO_R | SGX_SECINFO_W | SGX_SECINFO_REG | SGX_SECINFO_PENDING; + eaccept_op.ret = 0; + eaccept_op.header.type = ENCL_OP_EACCEPT; + + EXPECT_EQ(ENCL_CALL(&eaccept_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + EXPECT_EQ(eaccept_op.ret, 0); + + /* Can now return to main TCS to resume execution. */ + self->run.tcs = self->encl.encl_base; + + EXPECT_EQ(vdso_sgx_enter_enclave((unsigned long)&put_addr_op, 0, 0, + ERESUME, 0, 0, + &self->run), + 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* + * Read memory from newly added page that was just written to, + * confirming that data previously written (MAGIC) is present. + */ + get_addr_op.value = 0; + get_addr_op.addr = (unsigned long)addr; + get_addr_op.header.type = ENCL_OP_GET_FROM_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&get_addr_op, &self->run, true), 0); + + EXPECT_EQ(get_addr_op.value, MAGIC); + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + munmap(addr, PAGE_SIZE); +} + +/* + * Test for the addition of pages to an initialized enclave via a + * pre-emptive run of EACCEPT on page to be added. + */ +TEST_F(enclave, augment_via_eaccept) +{ + struct encl_op_get_from_addr get_addr_op; + struct encl_op_put_to_addr put_addr_op; + struct encl_op_eaccept eaccept_op; + size_t total_size = 0; + void *addr; + int i; + + if (!sgx2_supported()) + SKIP(return, "SGX2 not supported"); + + ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata)); + + memset(&self->run, 0, sizeof(self->run)); + self->run.tcs = self->encl.encl_base; + + for (i = 0; i < self->encl.nr_segments; i++) { + struct encl_segment *seg = &self->encl.segment_tbl[i]; + + total_size += seg->size; + } + + /* + * Actual enclave size is expected to be larger than the loaded + * test enclave since enclave size must be a power of 2 in bytes while + * test_encl does not consume it all. + */ + EXPECT_LT(total_size + PAGE_SIZE, self->encl.encl_size); + + /* + * mmap() a page at end of existing enclave to be used for dynamic + * EPC page. + * + * Kernel will allow new mapping using any permissions if it + * falls into the enclave's address range but not backed + * by existing enclave pages. + */ + + addr = mmap((void *)self->encl.encl_base + total_size, PAGE_SIZE, + PROT_READ | PROT_WRITE | PROT_EXEC, MAP_SHARED | MAP_FIXED, + self->encl.fd, 0); + EXPECT_NE(addr, MAP_FAILED); + + self->run.exception_vector = 0; + self->run.exception_error_code = 0; + self->run.exception_addr = 0; + + /* + * Run EACCEPT on new page to trigger the #PF->EAUG->EACCEPT(again + * without a #PF). All should be transparent to userspace. + */ + eaccept_op.epc_addr = self->encl.encl_base + total_size; + eaccept_op.flags = SGX_SECINFO_R | SGX_SECINFO_W | SGX_SECINFO_REG | SGX_SECINFO_PENDING; + eaccept_op.ret = 0; + eaccept_op.header.type = ENCL_OP_EACCEPT; + + EXPECT_EQ(ENCL_CALL(&eaccept_op, &self->run, true), 0); + + if (self->run.exception_vector == 14 && + self->run.exception_error_code == 4 && + self->run.exception_addr == self->encl.encl_base + total_size) { + munmap(addr, PAGE_SIZE); + SKIP(return, "Kernel does not support adding pages to initialized enclave"); + } + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + EXPECT_EQ(eaccept_op.ret, 0); + + /* + * New page should be accessible from within enclave - attempt to + * write to it. + */ + put_addr_op.value = MAGIC; + put_addr_op.addr = (unsigned long)addr; + put_addr_op.header.type = ENCL_OP_PUT_TO_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&put_addr_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* + * Read memory from newly added page that was just written to, + * confirming that data previously written (MAGIC) is present. + */ + get_addr_op.value = 0; + get_addr_op.addr = (unsigned long)addr; + get_addr_op.header.type = ENCL_OP_GET_FROM_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&get_addr_op, &self->run, true), 0); + + EXPECT_EQ(get_addr_op.value, MAGIC); + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + munmap(addr, PAGE_SIZE); +} + +/* + * SGX2 page type modification test in two phases: + * Phase 1: + * Create a new TCS, consisting out of three new pages (stack page with regular + * page type, SSA page with regular page type, and TCS page with TCS page + * type) in an initialized enclave and run a simple workload within it. + * Phase 2: + * Remove the three pages added in phase 1, add a new regular page at the + * same address that previously hosted the TCS page and verify that it can + * be modified. + */ +TEST_F(enclave, tcs_create) +{ + struct encl_op_init_tcs_page init_tcs_page_op; + struct sgx_enclave_remove_pages remove_ioc; + struct encl_op_get_from_addr get_addr_op; + struct sgx_enclave_modify_types modt_ioc; + struct encl_op_put_to_addr put_addr_op; + struct encl_op_get_from_buf get_buf_op; + struct encl_op_put_to_buf put_buf_op; + void *addr, *tcs, *stack_end, *ssa; + struct encl_op_eaccept eaccept_op; + size_t total_size = 0; + uint64_t val_64; + int errno_save; + int ret, i; + + ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, + _metadata)); + + memset(&self->run, 0, sizeof(self->run)); + self->run.tcs = self->encl.encl_base; + + /* + * Hardware (SGX2) and kernel support is needed for this test. Start + * with check that test has a chance of succeeding. + */ + memset(&modt_ioc, 0, sizeof(modt_ioc)); + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &modt_ioc); + + if (ret == -1) { + if (errno == ENOTTY) + SKIP(return, + "Kernel does not support SGX_IOC_ENCLAVE_MODIFY_TYPES ioctl()"); + else if (errno == ENODEV) + SKIP(return, "System does not support SGX2"); + } + + /* + * Invalid parameters were provided during sanity check, + * expect command to fail. + */ + EXPECT_EQ(ret, -1); + + /* + * Add three regular pages via EAUG: one will be the TCS stack, one + * will be the TCS SSA, and one will be the new TCS. The stack and + * SSA will remain as regular pages, the TCS page will need its + * type changed after populated with needed data. + */ + for (i = 0; i < self->encl.nr_segments; i++) { + struct encl_segment *seg = &self->encl.segment_tbl[i]; + + total_size += seg->size; + } + + /* + * Actual enclave size is expected to be larger than the loaded + * test enclave since enclave size must be a power of 2 in bytes while + * test_encl does not consume it all. + */ + EXPECT_LT(total_size + 3 * PAGE_SIZE, self->encl.encl_size); + + /* + * mmap() three pages at end of existing enclave to be used for the + * three new pages. + */ + addr = mmap((void *)self->encl.encl_base + total_size, 3 * PAGE_SIZE, + PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, + self->encl.fd, 0); + EXPECT_NE(addr, MAP_FAILED); + + self->run.exception_vector = 0; + self->run.exception_error_code = 0; + self->run.exception_addr = 0; + + stack_end = (void *)self->encl.encl_base + total_size; + tcs = (void *)self->encl.encl_base + total_size + PAGE_SIZE; + ssa = (void *)self->encl.encl_base + total_size + 2 * PAGE_SIZE; + + /* + * Run EACCEPT on each new page to trigger the + * EACCEPT->(#PF)->EAUG->EACCEPT(again without a #PF) flow. + */ + + eaccept_op.epc_addr = (unsigned long)stack_end; + eaccept_op.flags = SGX_SECINFO_R | SGX_SECINFO_W | SGX_SECINFO_REG | SGX_SECINFO_PENDING; + eaccept_op.ret = 0; + eaccept_op.header.type = ENCL_OP_EACCEPT; + + EXPECT_EQ(ENCL_CALL(&eaccept_op, &self->run, true), 0); + + if (self->run.exception_vector == 14 && + self->run.exception_error_code == 4 && + self->run.exception_addr == (unsigned long)stack_end) { + munmap(addr, 3 * PAGE_SIZE); + SKIP(return, "Kernel does not support adding pages to initialized enclave"); + } + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + EXPECT_EQ(eaccept_op.ret, 0); + + eaccept_op.epc_addr = (unsigned long)ssa; + + EXPECT_EQ(ENCL_CALL(&eaccept_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + EXPECT_EQ(eaccept_op.ret, 0); + + eaccept_op.epc_addr = (unsigned long)tcs; + + EXPECT_EQ(ENCL_CALL(&eaccept_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + EXPECT_EQ(eaccept_op.ret, 0); + + /* + * Three new pages added to enclave. Now populate the TCS page with + * needed data. This should be done from within enclave. Provide + * the function that will do the actual data population with needed + * data. + */ + + /* + * New TCS will use the "encl_dyn_entry" entrypoint that expects + * stack to begin in page before TCS page. + */ + val_64 = encl_get_entry(&self->encl, "encl_dyn_entry"); + EXPECT_NE(val_64, 0); + + init_tcs_page_op.tcs_page = (unsigned long)tcs; + init_tcs_page_op.ssa = (unsigned long)total_size + 2 * PAGE_SIZE; + init_tcs_page_op.entry = val_64; + init_tcs_page_op.header.type = ENCL_OP_INIT_TCS_PAGE; + + EXPECT_EQ(ENCL_CALL(&init_tcs_page_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* Change TCS page type to TCS. */ + memset(&modt_ioc, 0, sizeof(modt_ioc)); + + modt_ioc.offset = total_size + PAGE_SIZE; + modt_ioc.length = PAGE_SIZE; + modt_ioc.page_type = SGX_PAGE_TYPE_TCS; + + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &modt_ioc); + errno_save = ret == -1 ? errno : 0; + + EXPECT_EQ(ret, 0); + EXPECT_EQ(errno_save, 0); + EXPECT_EQ(modt_ioc.result, 0); + EXPECT_EQ(modt_ioc.count, 4096); + + /* EACCEPT new TCS page from enclave. */ + eaccept_op.epc_addr = (unsigned long)tcs; + eaccept_op.flags = SGX_SECINFO_TCS | SGX_SECINFO_MODIFIED; + eaccept_op.ret = 0; + eaccept_op.header.type = ENCL_OP_EACCEPT; + + EXPECT_EQ(ENCL_CALL(&eaccept_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + EXPECT_EQ(eaccept_op.ret, 0); + + /* Run workload from new TCS. */ + self->run.tcs = (unsigned long)tcs; + + /* + * Simple workload to write to data buffer and read value back. + */ + put_buf_op.header.type = ENCL_OP_PUT_TO_BUFFER; + put_buf_op.value = MAGIC; + + EXPECT_EQ(ENCL_CALL(&put_buf_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + get_buf_op.header.type = ENCL_OP_GET_FROM_BUFFER; + get_buf_op.value = 0; + + EXPECT_EQ(ENCL_CALL(&get_buf_op, &self->run, true), 0); + + EXPECT_EQ(get_buf_op.value, MAGIC); + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* + * Phase 2 of test: + * Remove pages associated with new TCS, create a regular page + * where TCS page used to be and verify it can be used as a regular + * page. + */ + + /* Start page removal by requesting change of page type to PT_TRIM. */ + memset(&modt_ioc, 0, sizeof(modt_ioc)); + + modt_ioc.offset = total_size; + modt_ioc.length = 3 * PAGE_SIZE; + modt_ioc.page_type = SGX_PAGE_TYPE_TRIM; + + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &modt_ioc); + errno_save = ret == -1 ? errno : 0; + + EXPECT_EQ(ret, 0); + EXPECT_EQ(errno_save, 0); + EXPECT_EQ(modt_ioc.result, 0); + EXPECT_EQ(modt_ioc.count, 3 * PAGE_SIZE); + + /* + * Enter enclave via TCS #1 and approve page removal by sending + * EACCEPT for each of three removed pages. + */ + self->run.tcs = self->encl.encl_base; + + eaccept_op.epc_addr = (unsigned long)stack_end; + eaccept_op.flags = SGX_SECINFO_TRIM | SGX_SECINFO_MODIFIED; + eaccept_op.ret = 0; + eaccept_op.header.type = ENCL_OP_EACCEPT; + + EXPECT_EQ(ENCL_CALL(&eaccept_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + EXPECT_EQ(eaccept_op.ret, 0); + + eaccept_op.epc_addr = (unsigned long)tcs; + eaccept_op.ret = 0; + + EXPECT_EQ(ENCL_CALL(&eaccept_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + EXPECT_EQ(eaccept_op.ret, 0); + + eaccept_op.epc_addr = (unsigned long)ssa; + eaccept_op.ret = 0; + + EXPECT_EQ(ENCL_CALL(&eaccept_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + EXPECT_EQ(eaccept_op.ret, 0); + + /* Send final ioctl() to complete page removal. */ + memset(&remove_ioc, 0, sizeof(remove_ioc)); + + remove_ioc.offset = total_size; + remove_ioc.length = 3 * PAGE_SIZE; + + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_REMOVE_PAGES, &remove_ioc); + errno_save = ret == -1 ? errno : 0; + + EXPECT_EQ(ret, 0); + EXPECT_EQ(errno_save, 0); + EXPECT_EQ(remove_ioc.count, 3 * PAGE_SIZE); + + /* + * Enter enclave via TCS #1 and access location where TCS #3 was to + * trigger dynamic add of regular page at that location. + */ + eaccept_op.epc_addr = (unsigned long)tcs; + eaccept_op.flags = SGX_SECINFO_R | SGX_SECINFO_W | SGX_SECINFO_REG | SGX_SECINFO_PENDING; + eaccept_op.ret = 0; + eaccept_op.header.type = ENCL_OP_EACCEPT; + + EXPECT_EQ(ENCL_CALL(&eaccept_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + EXPECT_EQ(eaccept_op.ret, 0); + + /* + * New page should be accessible from within enclave - write to it. + */ + put_addr_op.value = MAGIC; + put_addr_op.addr = (unsigned long)tcs; + put_addr_op.header.type = ENCL_OP_PUT_TO_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&put_addr_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* + * Read memory from newly added page that was just written to, + * confirming that data previously written (MAGIC) is present. + */ + get_addr_op.value = 0; + get_addr_op.addr = (unsigned long)tcs; + get_addr_op.header.type = ENCL_OP_GET_FROM_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&get_addr_op, &self->run, true), 0); + + EXPECT_EQ(get_addr_op.value, MAGIC); + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + munmap(addr, 3 * PAGE_SIZE); +} + +/* + * Ensure sane behavior if user requests page removal, does not run + * EACCEPT from within enclave but still attempts to finalize page removal + * with the SGX_IOC_ENCLAVE_REMOVE_PAGES ioctl(). The latter should fail + * because the removal was not EACCEPTed from within the enclave. + */ +TEST_F(enclave, remove_added_page_no_eaccept) +{ + struct sgx_enclave_remove_pages remove_ioc; + struct encl_op_get_from_addr get_addr_op; + struct sgx_enclave_modify_types modt_ioc; + struct encl_op_put_to_addr put_addr_op; + unsigned long data_start; + int ret, errno_save; + + ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata)); + + memset(&self->run, 0, sizeof(self->run)); + self->run.tcs = self->encl.encl_base; + + /* + * Hardware (SGX2) and kernel support is needed for this test. Start + * with check that test has a chance of succeeding. + */ + memset(&modt_ioc, 0, sizeof(modt_ioc)); + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &modt_ioc); + + if (ret == -1) { + if (errno == ENOTTY) + SKIP(return, + "Kernel does not support SGX_IOC_ENCLAVE_MODIFY_TYPES ioctl()"); + else if (errno == ENODEV) + SKIP(return, "System does not support SGX2"); + } + + /* + * Invalid parameters were provided during sanity check, + * expect command to fail. + */ + EXPECT_EQ(ret, -1); + + /* + * Page that will be removed is the second data page in the .data + * segment. This forms part of the local encl_buffer within the + * enclave. + */ + data_start = self->encl.encl_base + + encl_get_data_offset(&self->encl) + PAGE_SIZE; + + /* + * Sanity check that page at @data_start is writable before + * removing it. + * + * Start by writing MAGIC to test page. + */ + put_addr_op.value = MAGIC; + put_addr_op.addr = data_start; + put_addr_op.header.type = ENCL_OP_PUT_TO_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&put_addr_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* + * Read memory that was just written to, confirming that data + * previously written (MAGIC) is present. + */ + get_addr_op.value = 0; + get_addr_op.addr = data_start; + get_addr_op.header.type = ENCL_OP_GET_FROM_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&get_addr_op, &self->run, true), 0); + + EXPECT_EQ(get_addr_op.value, MAGIC); + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* Start page removal by requesting change of page type to PT_TRIM */ + memset(&modt_ioc, 0, sizeof(modt_ioc)); + + modt_ioc.offset = encl_get_data_offset(&self->encl) + PAGE_SIZE; + modt_ioc.length = PAGE_SIZE; + modt_ioc.page_type = SGX_PAGE_TYPE_TRIM; + + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &modt_ioc); + errno_save = ret == -1 ? errno : 0; + + EXPECT_EQ(ret, 0); + EXPECT_EQ(errno_save, 0); + EXPECT_EQ(modt_ioc.result, 0); + EXPECT_EQ(modt_ioc.count, 4096); + + /* Skip EACCEPT */ + + /* Send final ioctl() to complete page removal */ + memset(&remove_ioc, 0, sizeof(remove_ioc)); + + remove_ioc.offset = encl_get_data_offset(&self->encl) + PAGE_SIZE; + remove_ioc.length = PAGE_SIZE; + + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_REMOVE_PAGES, &remove_ioc); + errno_save = ret == -1 ? errno : 0; + + /* Operation not permitted since EACCEPT was omitted. */ + EXPECT_EQ(ret, -1); + EXPECT_EQ(errno_save, EPERM); + EXPECT_EQ(remove_ioc.count, 0); +} + +/* + * Request enclave page removal but instead of correctly following with + * EACCEPT a read attempt to page is made from within the enclave. + */ +TEST_F(enclave, remove_added_page_invalid_access) +{ + struct encl_op_get_from_addr get_addr_op; + struct encl_op_put_to_addr put_addr_op; + struct sgx_enclave_modify_types ioc; + unsigned long data_start; + int ret, errno_save; + + ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata)); + + memset(&self->run, 0, sizeof(self->run)); + self->run.tcs = self->encl.encl_base; + + /* + * Hardware (SGX2) and kernel support is needed for this test. Start + * with check that test has a chance of succeeding. + */ + memset(&ioc, 0, sizeof(ioc)); + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &ioc); + + if (ret == -1) { + if (errno == ENOTTY) + SKIP(return, + "Kernel does not support SGX_IOC_ENCLAVE_MODIFY_TYPES ioctl()"); + else if (errno == ENODEV) + SKIP(return, "System does not support SGX2"); + } + + /* + * Invalid parameters were provided during sanity check, + * expect command to fail. + */ + EXPECT_EQ(ret, -1); + + /* + * Page that will be removed is the second data page in the .data + * segment. This forms part of the local encl_buffer within the + * enclave. + */ + data_start = self->encl.encl_base + + encl_get_data_offset(&self->encl) + PAGE_SIZE; + + /* + * Sanity check that page at @data_start is writable before + * removing it. + * + * Start by writing MAGIC to test page. + */ + put_addr_op.value = MAGIC; + put_addr_op.addr = data_start; + put_addr_op.header.type = ENCL_OP_PUT_TO_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&put_addr_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* + * Read memory that was just written to, confirming that data + * previously written (MAGIC) is present. + */ + get_addr_op.value = 0; + get_addr_op.addr = data_start; + get_addr_op.header.type = ENCL_OP_GET_FROM_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&get_addr_op, &self->run, true), 0); + + EXPECT_EQ(get_addr_op.value, MAGIC); + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* Start page removal by requesting change of page type to PT_TRIM. */ + memset(&ioc, 0, sizeof(ioc)); + + ioc.offset = encl_get_data_offset(&self->encl) + PAGE_SIZE; + ioc.length = PAGE_SIZE; + ioc.page_type = SGX_PAGE_TYPE_TRIM; + + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &ioc); + errno_save = ret == -1 ? errno : 0; + + EXPECT_EQ(ret, 0); + EXPECT_EQ(errno_save, 0); + EXPECT_EQ(ioc.result, 0); + EXPECT_EQ(ioc.count, 4096); + + /* + * Read from page that was just removed. + */ + get_addr_op.value = 0; + + EXPECT_EQ(ENCL_CALL(&get_addr_op, &self->run, true), 0); + + /* + * From kernel perspective the page is present but according to SGX the + * page should not be accessible so a #PF with SGX bit set is + * expected. + */ + + EXPECT_EQ(self->run.function, ERESUME); + EXPECT_EQ(self->run.exception_vector, 14); + EXPECT_EQ(self->run.exception_error_code, 0x8005); + EXPECT_EQ(self->run.exception_addr, data_start); +} + +/* + * Request enclave page removal and correctly follow with + * EACCEPT but do not follow with removal ioctl() but instead a read attempt + * to removed page is made from within the enclave. + */ +TEST_F(enclave, remove_added_page_invalid_access_after_eaccept) +{ + struct encl_op_get_from_addr get_addr_op; + struct encl_op_put_to_addr put_addr_op; + struct sgx_enclave_modify_types ioc; + struct encl_op_eaccept eaccept_op; + unsigned long data_start; + int ret, errno_save; + + ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata)); + + memset(&self->run, 0, sizeof(self->run)); + self->run.tcs = self->encl.encl_base; + + /* + * Hardware (SGX2) and kernel support is needed for this test. Start + * with check that test has a chance of succeeding. + */ + memset(&ioc, 0, sizeof(ioc)); + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &ioc); + + if (ret == -1) { + if (errno == ENOTTY) + SKIP(return, + "Kernel does not support SGX_IOC_ENCLAVE_MODIFY_TYPES ioctl()"); + else if (errno == ENODEV) + SKIP(return, "System does not support SGX2"); + } + + /* + * Invalid parameters were provided during sanity check, + * expect command to fail. + */ + EXPECT_EQ(ret, -1); + + /* + * Page that will be removed is the second data page in the .data + * segment. This forms part of the local encl_buffer within the + * enclave. + */ + data_start = self->encl.encl_base + + encl_get_data_offset(&self->encl) + PAGE_SIZE; + + /* + * Sanity check that page at @data_start is writable before + * removing it. + * + * Start by writing MAGIC to test page. + */ + put_addr_op.value = MAGIC; + put_addr_op.addr = data_start; + put_addr_op.header.type = ENCL_OP_PUT_TO_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&put_addr_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* + * Read memory that was just written to, confirming that data + * previously written (MAGIC) is present. + */ + get_addr_op.value = 0; + get_addr_op.addr = data_start; + get_addr_op.header.type = ENCL_OP_GET_FROM_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&get_addr_op, &self->run, true), 0); + + EXPECT_EQ(get_addr_op.value, MAGIC); + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* Start page removal by requesting change of page type to PT_TRIM. */ + memset(&ioc, 0, sizeof(ioc)); + + ioc.offset = encl_get_data_offset(&self->encl) + PAGE_SIZE; + ioc.length = PAGE_SIZE; + ioc.page_type = SGX_PAGE_TYPE_TRIM; + + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &ioc); + errno_save = ret == -1 ? errno : 0; + + EXPECT_EQ(ret, 0); + EXPECT_EQ(errno_save, 0); + EXPECT_EQ(ioc.result, 0); + EXPECT_EQ(ioc.count, 4096); + + eaccept_op.epc_addr = (unsigned long)data_start; + eaccept_op.ret = 0; + eaccept_op.flags = SGX_SECINFO_TRIM | SGX_SECINFO_MODIFIED; + eaccept_op.header.type = ENCL_OP_EACCEPT; + + EXPECT_EQ(ENCL_CALL(&eaccept_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + EXPECT_EQ(eaccept_op.ret, 0); + + /* Skip ioctl() to remove page. */ + + /* + * Read from page that was just removed. + */ + get_addr_op.value = 0; + + EXPECT_EQ(ENCL_CALL(&get_addr_op, &self->run, true), 0); + + /* + * From kernel perspective the page is present but according to SGX the + * page should not be accessible so a #PF with SGX bit set is + * expected. + */ + + EXPECT_EQ(self->run.function, ERESUME); + EXPECT_EQ(self->run.exception_vector, 14); + EXPECT_EQ(self->run.exception_error_code, 0x8005); + EXPECT_EQ(self->run.exception_addr, data_start); +} + +TEST_F(enclave, remove_untouched_page) +{ + struct sgx_enclave_remove_pages remove_ioc; + struct sgx_enclave_modify_types modt_ioc; + struct encl_op_eaccept eaccept_op; + unsigned long data_start; + int ret, errno_save; + + ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata)); + + /* + * Hardware (SGX2) and kernel support is needed for this test. Start + * with check that test has a chance of succeeding. + */ + memset(&modt_ioc, 0, sizeof(modt_ioc)); + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &modt_ioc); + + if (ret == -1) { + if (errno == ENOTTY) + SKIP(return, + "Kernel does not support SGX_IOC_ENCLAVE_MODIFY_TYPES ioctl()"); + else if (errno == ENODEV) + SKIP(return, "System does not support SGX2"); + } + + /* + * Invalid parameters were provided during sanity check, + * expect command to fail. + */ + EXPECT_EQ(ret, -1); + + /* SGX2 is supported by kernel and hardware, test can proceed. */ + memset(&self->run, 0, sizeof(self->run)); + self->run.tcs = self->encl.encl_base; + + data_start = self->encl.encl_base + + encl_get_data_offset(&self->encl) + PAGE_SIZE; + + memset(&modt_ioc, 0, sizeof(modt_ioc)); + + modt_ioc.offset = encl_get_data_offset(&self->encl) + PAGE_SIZE; + modt_ioc.length = PAGE_SIZE; + modt_ioc.page_type = SGX_PAGE_TYPE_TRIM; + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &modt_ioc); + errno_save = ret == -1 ? errno : 0; + + EXPECT_EQ(ret, 0); + EXPECT_EQ(errno_save, 0); + EXPECT_EQ(modt_ioc.result, 0); + EXPECT_EQ(modt_ioc.count, 4096); + + /* + * Enter enclave via TCS #1 and approve page removal by sending + * EACCEPT for removed page. + */ + + eaccept_op.epc_addr = data_start; + eaccept_op.flags = SGX_SECINFO_TRIM | SGX_SECINFO_MODIFIED; + eaccept_op.ret = 0; + eaccept_op.header.type = ENCL_OP_EACCEPT; + + EXPECT_EQ(ENCL_CALL(&eaccept_op, &self->run, true), 0); + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + EXPECT_EQ(eaccept_op.ret, 0); + + memset(&remove_ioc, 0, sizeof(remove_ioc)); + + remove_ioc.offset = encl_get_data_offset(&self->encl) + PAGE_SIZE; + remove_ioc.length = PAGE_SIZE; + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_REMOVE_PAGES, &remove_ioc); + errno_save = ret == -1 ? errno : 0; + + EXPECT_EQ(ret, 0); + EXPECT_EQ(errno_save, 0); + EXPECT_EQ(remove_ioc.count, 4096); +} + TEST_HARNESS_MAIN diff --git a/tools/testing/selftests/sgx/main.h b/tools/testing/selftests/sgx/main.h index b45c52ec7ab3..fc585be97e2f 100644 --- a/tools/testing/selftests/sgx/main.h +++ b/tools/testing/selftests/sgx/main.h @@ -38,6 +38,7 @@ void encl_delete(struct encl *ctx); bool encl_load(const char *path, struct encl *encl, unsigned long heap_size); bool encl_measure(struct encl *encl); bool encl_build(struct encl *encl); +uint64_t encl_get_entry(struct encl *encl, const char *symbol); int sgx_enter_enclave(void *rdi, void *rsi, long rdx, u32 function, void *r8, void *r9, struct sgx_enclave_run *run); diff --git a/tools/testing/selftests/sgx/test_encl.c b/tools/testing/selftests/sgx/test_encl.c index 4fca01cfd898..c0d6397295e3 100644 --- a/tools/testing/selftests/sgx/test_encl.c +++ b/tools/testing/selftests/sgx/test_encl.c @@ -11,6 +11,42 @@ */ static uint8_t encl_buffer[8192] = { 1 }; +enum sgx_enclu_function { + EACCEPT = 0x5, + EMODPE = 0x6, +}; + +static void do_encl_emodpe(void *_op) +{ + struct sgx_secinfo secinfo __aligned(sizeof(struct sgx_secinfo)) = {0}; + struct encl_op_emodpe *op = _op; + + secinfo.flags = op->flags; + + asm volatile(".byte 0x0f, 0x01, 0xd7" + : + : "a" (EMODPE), + "b" (&secinfo), + "c" (op->epc_addr)); +} + +static void do_encl_eaccept(void *_op) +{ + struct sgx_secinfo secinfo __aligned(sizeof(struct sgx_secinfo)) = {0}; + struct encl_op_eaccept *op = _op; + int rax; + + secinfo.flags = op->flags; + + asm volatile(".byte 0x0f, 0x01, 0xd7" + : "=a" (rax) + : "a" (EACCEPT), + "b" (&secinfo), + "c" (op->epc_addr)); + + op->ret = rax; +} + static void *memcpy(void *dest, const void *src, size_t n) { size_t i; @@ -21,6 +57,35 @@ static void *memcpy(void *dest, const void *src, size_t n) return dest; } +static void *memset(void *dest, int c, size_t n) +{ + size_t i; + + for (i = 0; i < n; i++) + ((char *)dest)[i] = c; + + return dest; +} + +static void do_encl_init_tcs_page(void *_op) +{ + struct encl_op_init_tcs_page *op = _op; + void *tcs = (void *)op->tcs_page; + uint32_t val_32; + + memset(tcs, 0, 16); /* STATE and FLAGS */ + memcpy(tcs + 16, &op->ssa, 8); /* OSSA */ + memset(tcs + 24, 0, 4); /* CSSA */ + val_32 = 1; + memcpy(tcs + 28, &val_32, 4); /* NSSA */ + memcpy(tcs + 32, &op->entry, 8); /* OENTRY */ + memset(tcs + 40, 0, 24); /* AEP, OFSBASE, OGSBASE */ + val_32 = 0xFFFFFFFF; + memcpy(tcs + 64, &val_32, 4); /* FSLIMIT */ + memcpy(tcs + 68, &val_32, 4); /* GSLIMIT */ + memset(tcs + 72, 0, 4024); /* Reserved */ +} + static void do_encl_op_put_to_buf(void *op) { struct encl_op_put_to_buf *op2 = op; @@ -62,6 +127,9 @@ void encl_body(void *rdi, void *rsi) do_encl_op_put_to_addr, do_encl_op_get_from_addr, do_encl_op_nop, + do_encl_eaccept, + do_encl_emodpe, + do_encl_init_tcs_page, }; struct encl_op_header *op = (struct encl_op_header *)rdi; diff --git a/tools/testing/selftests/sgx/test_encl_bootstrap.S b/tools/testing/selftests/sgx/test_encl_bootstrap.S index 82fb0dfcbd23..03ae0f57e29d 100644 --- a/tools/testing/selftests/sgx/test_encl_bootstrap.S +++ b/tools/testing/selftests/sgx/test_encl_bootstrap.S @@ -45,6 +45,12 @@ encl_entry: # TCS #2. By adding the value of encl_stack to it, we get # the absolute address for the stack. lea (encl_stack)(%rbx), %rax + jmp encl_entry_core +encl_dyn_entry: + # Entry point for dynamically created TCS page expected to follow + # its stack directly. + lea -1(%rbx), %rax +encl_entry_core: xchg %rsp, %rax push %rax