The SGX ENCLS instruction uses EAX to specify an SGX function and may require additional registers, depending on the SGX function. ENCLS invokes the specified privileged SGX function for managing and debugging enclaves. Macros are used to wrap the ENCLS functionality and several wrappers are used to wrap the macros to make the different SGX functions accessible in the code.

The wrappers of the supported SGX functions are cryptic. Add short descriptions of each as a comment.

Suggested-by: Dave Hansen dave.hansen@linux.intel.com Reviewed-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Reinette Chatre reinette.chatre@intel.com --- No changes since V4.

Changes since V3: - Add Jarkko's Reviewed-by tag.

Changes since V1: - Fix commit message and subject to not refer to descriptions as "changelog descriptions" or "shortlog descriptions" (Jarkko). - Improve all descriptions with guidance from Jarkko.

arch/x86/kernel/cpu/sgx/encls.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+)

diff --git a/arch/x86/kernel/cpu/sgx/encls.h b/arch/x86/kernel/cpu/sgx/encls.h index fa04a73daf9c..0e22fa8f77c5 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; @@ -194,6 +208,7 @@ 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) {

Add a wrapper for the EMODT ENCLS leaf function used to change the type of an enclave page as maintained in the SGX hardware's Enclave Page Cache Map (EPCM).

EMODT: 1) Updates the EPCM page type of the enclave page. 2) Sets the MODIFIED bit in the EPCM entry of the enclave page. This bit is reset by the enclave by invoking ENCLU leaf function EACCEPT or EACCEPTCOPY.

Access from within the enclave to the enclave page is not possible while the MODIFIED bit is set.

After changing the enclave page type by issuing EMODT the kernel needs to collaborate with the hardware to ensure that no logical processor continues to hold a reference to the changed page. This is required to ensure no required security checks are circumvented and is required for the enclave's EACCEPT/EACCEPTCOPY to succeed. Ensuring that no references to the changed page remain is accomplished with the ETRACK flow.

Reviewed-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Reinette Chatre reinette.chatre@intel.com --- No changes since V4.

Changes since V3: - Add Jarkko's Reviewed-by tag.

Changes since V1: - Split original patch ("x86/sgx: Add wrappers for SGX2 functions") in three to introduce the SGX2 functions separately (Jarkko). - Rewrite commit message to include how the EPCM within the hardware is changed by the SGX2 function as well as the calling conditions (Jarkko).

arch/x86/kernel/cpu/sgx/encls.h | 6 ++++++ 1 file changed, 6 insertions(+)

diff --git a/arch/x86/kernel/cpu/sgx/encls.h b/arch/x86/kernel/cpu/sgx/encls.h index 2b091912f038..7a1ecf704ec1 100644 --- a/arch/x86/kernel/cpu/sgx/encls.h +++ b/arch/x86/kernel/cpu/sgx/encls.h @@ -221,4 +221,10 @@ 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); +} + #endif /* _X86_ENCLS_H */

sgx_encl_load_page() is used to find and load an enclave page into enclave (EPC) memory, potentially loading it from the backing storage. Both usages of sgx_encl_load_page() are during an access to the enclave page from a VMA and thus the permissions of the VMA are considered before the enclave page is loaded.

SGX2 functions operating on enclave pages belonging to an initialized enclave requiring the page to be in EPC. It is thus required to support loading enclave pages into the EPC independent from a VMA.

Split the current sgx_encl_load_page() to support the two usages: A new call, sgx_encl_load_page_in_vma(), behaves exactly like the current sgx_encl_load_page() that takes VMA permissions into account, while sgx_encl_load_page() just loads an enclave page into EPC.

VMA, PTE, and EPCM permissions continue to dictate whether the pages can be accessed from within an enclave.

Reviewed-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Reinette Chatre reinette.chatre@intel.com --- No changes since V4.

Changes since V3: - Add Jarkko's Reviewed-by tag.

Changes since V2: - New patch

arch/x86/kernel/cpu/sgx/encl.c | 57 ++++++++++++++++++++++------------ arch/x86/kernel/cpu/sgx/encl.h | 2 ++ 2 files changed, 40 insertions(+), 19 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c index af972dbad965..7217c492e103 100644 --- a/arch/x86/kernel/cpu/sgx/encl.c +++ b/arch/x86/kernel/cpu/sgx/encl.c @@ -227,25 +227,10 @@ 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) { @@ -271,6 +256,40 @@ 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); +} + static vm_fault_t sgx_vma_fault(struct vm_fault *vmf) { unsigned long addr = (unsigned long)vmf->address; @@ -292,7 +311,7 @@ static vm_fault_t sgx_vma_fault(struct vm_fault *vmf)

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);

@@ -440,7 +459,7 @@ 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;

diff --git a/arch/x86/kernel/cpu/sgx/encl.h b/arch/x86/kernel/cpu/sgx/encl.h index d44e7372151f..522a17e4fd2d 100644 --- a/arch/x86/kernel/cpu/sgx/encl.h +++ b/arch/x86/kernel/cpu/sgx/encl.h @@ -116,5 +116,7 @@ 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);

#endif /* _X86_ENCL_H */

sgx_encl_ewb_cpumask() is no longer unique to the reclaimer where it is used during the EWB ENCLS leaf function when EPC pages are written out to main memory and sgx_encl_ewb_cpumask() is used to learn which CPUs might have executed the enclave to ensure that TLBs are cleared.

Upcoming SGX2 enabling will use sgx_encl_ewb_cpumask() during the EMODPR and EMODT ENCLS leaf functions that make changes to enclave pages. The function is needed for the same reason it is used now: to learn which CPUs might have executed the enclave to ensure that TLBs no longer point to the changed pages.

Rename sgx_encl_ewb_cpumask() to sgx_encl_cpumask() to reflect the broader usage.

Reviewed-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Reinette Chatre reinette.chatre@intel.com --- No changes since V4.

Changes since V3: - Add Jarkko's Reviewed-by tag.

Changes since V1: - New patch split from original "x86/sgx: Use more generic name for enclave cpumask function" (Jarkko).

arch/x86/kernel/cpu/sgx/encl.c | 6 +++--- arch/x86/kernel/cpu/sgx/encl.h | 2 +- arch/x86/kernel/cpu/sgx/main.c | 2 +- 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c index 04d8212ce400..1bbd76d91554 100644 --- a/arch/x86/kernel/cpu/sgx/encl.c +++ b/arch/x86/kernel/cpu/sgx/encl.c @@ -710,7 +710,7 @@ int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm) }

/** - * sgx_encl_ewb_cpumask() - Query which CPUs might be accessing the enclave + * 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 @@ -735,7 +735,7 @@ int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm) * 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_ewb_cpumask()) to query which CPUs might be + * 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. @@ -752,7 +752,7 @@ int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm) * * Return: cpumask of CPUs that might be accessing @encl */ -const cpumask_t *sgx_encl_ewb_cpumask(struct sgx_encl *encl) +const cpumask_t *sgx_encl_cpumask(struct sgx_encl *encl) { cpumask_t *cpumask = &encl->cpumask; struct sgx_encl_mm *encl_mm; diff --git a/arch/x86/kernel/cpu/sgx/encl.h b/arch/x86/kernel/cpu/sgx/encl.h index c6afa58ea3e6..ef8cf106904b 100644 --- a/arch/x86/kernel/cpu/sgx/encl.h +++ b/arch/x86/kernel/cpu/sgx/encl.h @@ -105,7 +105,7 @@ int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start,

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_ewb_cpumask(struct sgx_encl *encl); +const cpumask_t *sgx_encl_cpumask(struct sgx_encl *encl); int sgx_encl_get_backing(struct sgx_encl *encl, unsigned long page_index, struct sgx_backing *backing); void sgx_encl_put_backing(struct sgx_backing *backing); diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index d1af5828635d..736ca652caab 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -251,7 +251,7 @@ 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); }

The ETRACK function followed by an IPI to all CPUs within an enclave is a common pattern with more frequent use in support of SGX2.

Make the (empty) IPI callback function available internally in preparation for usage by SGX2.

Reviewed-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Reinette Chatre reinette.chatre@intel.com --- No changes since V4.

Changes since V3: - Add Jarkko's Reviewed-by tag.

Changes since V1: - Replace "for more usages" by "for usage by SGX2" (Jarkko)

arch/x86/kernel/cpu/sgx/main.c | 2 +- arch/x86/kernel/cpu/sgx/sgx.h | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index bb0d5e8905be..bab2a2e13c70 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -174,7 +174,7 @@ 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) { }

diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index 0f17def9fe6f..b30cee4de903 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -90,6 +90,8 @@ 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

SGX2 functions are not allowed on all page types. For example, ENCLS[EMODPR] is only allowed on regular SGX enclave pages and ENCLS[EMODPT] is only allowed on TCS and regular pages. If these functions are attempted on another type of page the hardware would trigger a fault.

Keep a record of the SGX page type so that there is more certainty whether an SGX2 instruction can succeed and faults can be treated as real failures.

The page type is a property of struct sgx_encl_page and thus does not cover the VA page type. VA pages are maintained in separate structures and their type can be determined in a different way. The SGX2 instructions needing the page type do not operate on VA pages and this is thus not a scenario needing to be covered at this time.

struct sgx_encl_page hosting this information is maintained for each enclave page so the space consumed by the struct is important. The existing sgx_encl_page->vm_max_prot_bits is already unsigned long while only using three bits. Transition to a bitfield for the two members to support the additional information without increasing the space consumed by the struct.

Reviewed-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Reinette Chatre reinette.chatre@intel.com --- Changes since V4: - Remove Jarkko's "Acked-by" that is overridden by his "Reviewed-by". (Jarkko)

Changes since V3: - Add Jarkko's Reviewed-by tag.

Changes since V2: - Update changelog to motivate transition to bitfield that was previously done when (now removed) vm_run_prot_bits was added.

Changes since V1: - Add Acked-by from Jarkko.

arch/x86/include/asm/sgx.h | 3 +++ arch/x86/kernel/cpu/sgx/encl.h | 3 ++- arch/x86/kernel/cpu/sgx/ioctl.c | 2 ++ 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h index d67810b50a81..eae20fa52b93 100644 --- a/arch/x86/include/asm/sgx.h +++ b/arch/x86/include/asm/sgx.h @@ -239,6 +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/kernel/cpu/sgx/encl.h b/arch/x86/kernel/cpu/sgx/encl.h index f72a674e2605..799d4cdb12d5 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; diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c index a66795e0b685..21078c6643f7 100644 --- a/arch/x86/kernel/cpu/sgx/ioctl.c +++ b/arch/x86/kernel/cpu/sgx/ioctl.c @@ -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; @@ -344,6 +345,7 @@ 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) {

From: Jarkko Sakkinen jarkko@kernel.org

Move sgx_encl_page_alloc() to encl.c and export it so that it can be used in the implementation for support of adding pages to initialized enclaves, which requires to allocate new enclave pages.

Signed-off-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Reinette Chatre reinette.chatre@intel.com --- No changes since V4.

Changes since V2: - New patch Originally submitted at: https://lore.kernel.org/linux-sgx/20220308112833.262805-3-jarkko@kernel.org/

arch/x86/kernel/cpu/sgx/encl.c | 32 ++++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/sgx/encl.h | 3 +++ arch/x86/kernel/cpu/sgx/ioctl.c | 32 -------------------------------- 3 files changed, 35 insertions(+), 32 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c index 91df05c6568f..2f053af9ce3e 100644 --- a/arch/x86/kernel/cpu/sgx/encl.c +++ b/arch/x86/kernel/cpu/sgx/encl.c @@ -882,6 +882,38 @@ 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 diff --git a/arch/x86/kernel/cpu/sgx/encl.h b/arch/x86/kernel/cpu/sgx/encl.h index b6b53c0346ad..2cb58ab868e5 100644 --- a/arch/x86/kernel/cpu/sgx/encl.h +++ b/arch/x86/kernel/cpu/sgx/encl.h @@ -112,6 +112,9 @@ int sgx_encl_get_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_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(void); unsigned int sgx_alloc_va_slot(struct sgx_va_page *va_page); diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c index 2df27dd8b30d..bb8cdb2ad0d1 100644 --- a/arch/x86/kernel/cpu/sgx/ioctl.c +++ b/arch/x86/kernel/cpu/sgx/ioctl.c @@ -169,38 +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;

In the initial (SGX1) version of SGX, pages in an enclave need to be created with permissions that support all usages of the pages, from the time the enclave is initialized until it is unloaded. For example, pages used by a JIT compiler or when code needs to otherwise be relocated need to always have RWX permissions.

SGX2 includes a new function ENCLS[EMODPR] that is run from the kernel and can be used to restrict the EPCM permissions of regular enclave pages within an initialized enclave.

Introduce ioctl() SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS to support restricting EPCM permissions. With this ioctl() the user specifies a page range and the EPCM permissions to be applied to all pages in the provided range. ENCLS[EMODPR] is run to restrict the EPCM permissions followed by the ENCLS[ETRACK] flow that will ensure no cached linear-to-physical address mappings to the changed pages remain.

It is possible for the permission change request to fail on any page within the provided range, either with an error encountered by the kernel or by the SGX hardware while running ENCLS[EMODPR]. To support partial success the ioctl() returns an error code based on failures encountered by the kernel as well as two result output parameters: one for the number of pages that were successfully changed and one for the SGX return code.

The page table entry permissions are not impacted by the EPCM permission changes. VMAs and PTEs will continue to allow the maximum vetted permissions determined at the time the pages are added to the enclave. The SGX error code in a page fault will indicate if it was an EPCM permission check that prevented an access attempt.

No checking is done to ensure that the permissions are actually being restricted. This is because the enclave may have relaxed the EPCM permissions from within the enclave without the kernel knowing. An attempt to relax permissions using this call will be ignored by the hardware.

Reviewed-by: Jarkko Sakkinen jarkko@kernel.org Tested-by: Jarkko Sakkinen jarkko@kernel.org Tested-by: Haitao Huang haitao.huang@intel.com Tested-by: Vijay Dhanraj vijay.dhanraj@intel.com Signed-off-by: Reinette Chatre reinette.chatre@intel.com --- Changes since V4: - Add Vijay's Tested-by tag. - Add Jarkko's Reviewed-by and Tested-by tags. - Add Haitao's Tested-by tag. - Revert change that required minimum of read permissions since requesting zero permissions is valid. Return earlier parameter check to ensure read permission accompanies write permission. (Vijay)

Changes since V3: - User provides only new permissions, replacing secinfo. (Jarkko) - Expand comments of sgx_enclave_etrack() to document the context in which the function is safe to use.

Changes since V2: - Include the sgx_ioc_sgx2_ready() utility that previously was in "x86/sgx: Support relaxing of enclave page permissions" that is removed from the next version. - Few renames requested by Jarkko: struct sgx_enclave_restrict_perm -> struct sgx_enclave_restrict_permissions sgx_enclave_restrict_perm() -> sgx_enclave_restrict_permissions() sgx_ioc_enclave_restrict_perm() -> sgx_ioc_enclave_restrict_permissions() - Make EPCM permissions independent from kernel view of permissions. (Jarkko) - Remove attempt at runtime tracking of EPCM permissions (sgx_encl_page->vm_run_prot_bits). - Do not flush page table entries - they are no longer impacted by EPCM permission changes. - Modify changelog to reflect new architecture. - Ensure at least PROT_READ is requested - enclave requires read access to the page for commands like EMODPE and EACCEPT. (Jarkko)

Changes since V1: - Change terminology to use "relax" instead of "extend" to refer to the case when enclave page permissions are added (Dave). - Use ioctl() in commit message (Dave). - Add examples on what permissions would be allowed (Dave). - Split enclave page permission changes into two ioctl()s, one for permission restricting (SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS) and one for permission relaxing (SGX_IOC_ENCLAVE_RELAX_PERMISSIONS) (Jarkko). - In support of the ioctl() name change the following names have been changed: struct sgx_page_modp -> struct sgx_enclave_restrict_perm sgx_ioc_page_modp() -> sgx_ioc_enclave_restrict_perm() sgx_page_modp() -> sgx_enclave_restrict_perm() - ioctl() takes entire secinfo as input instead of page permissions only (Jarkko). - Fix kernel-doc to include () in function name. - Create and use utility for the ETRACK flow. - Fixups in comments - Move kernel-doc to function that provides documentation for Documentation/x86/sgx.rst. - Remove redundant comment. - Make explicit which members of struct sgx_enclave_restrict_perm are for output (Dave).

arch/x86/include/uapi/asm/sgx.h | 21 ++++ arch/x86/kernel/cpu/sgx/ioctl.c | 216 ++++++++++++++++++++++++++++++++ 2 files changed, 237 insertions(+)

diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h index f4b81587e90b..82648c006470 100644 --- a/arch/x86/include/uapi/asm/sgx.h +++ b/arch/x86/include/uapi/asm/sgx.h @@ -29,6 +29,8 @@ 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)

/** * struct sgx_enclave_create - parameter structure for the @@ -76,6 +78,25 @@ 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_run;

/** diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c index 5d41aa204761..720188d86ed4 100644 --- a/arch/x86/kernel/cpu/sgx/ioctl.c +++ b/arch/x86/kernel/cpu/sgx/ioctl.c @@ -660,6 +660,218 @@ 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; + + 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(&params, 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, &params); + + if (copy_to_user(arg, &params, 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; @@ -681,6 +893,10 @@ 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; default: ret = -ENOIOCTLCMD; break;

Before an enclave is initialized the enclave's memory range is unknown. The enclave's memory range is learned at the time it is created via the SGX_IOC_ENCLAVE_CREATE ioctl() where the provided memory range is obtained from an earlier mmap() of /dev/sgx_enclave. After an enclave is initialized its memory can be mapped into user space (mmap()) from where it can be entered at its defined entry points.

With the enclave's memory range known after it is initialized there is no reason why it should be possible to map memory outside this range.

Lock down access to the initialized enclave's memory range by denying any attempt to map memory outside its memory range.

Locking down the memory range also makes adding pages to an initialized enclave more efficient. Pages are added to an initialized enclave by accessing memory that belongs to the enclave's memory range but not yet backed by an enclave page. If it is possible for user space to map memory that does not form part of the enclave then an access to this memory would eventually fail. Failures range from a prompt general protection fault if the access was an ENCLU[EACCEPT] from within the enclave, or a page fault via the vDSO if it was another access from within the enclave, or a SIGBUS (also resulting from a page fault) if the access was from outside the enclave.

Disallowing invalid memory to be mapped in the first place avoids preventable failures.

Reviewed-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Reinette Chatre reinette.chatre@intel.com --- No changes since V4.

Changes since V3: - Add Jarkko's Reviewed-by tag.

Changes since V1: - Add comment (Jarkko).

arch/x86/kernel/cpu/sgx/encl.c | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c index 1b9086648b2e..fcc145068498 100644 --- a/arch/x86/kernel/cpu/sgx/encl.c +++ b/arch/x86/kernel/cpu/sgx/encl.c @@ -498,6 +498,11 @@ 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.

The SGX2 page removal flow was introduced in previous patch and is as follows: 1) Change the type of the pages to be removed to SGX_PAGE_TYPE_TRIM using the ioctl() SGX_IOC_ENCLAVE_MODIFY_TYPES introduced in previous patch. 2) Approve the page removal by running ENCLU[EACCEPT] from within the enclave. 3) Initiate actual page removal using the ioctl() SGX_IOC_ENCLAVE_REMOVE_PAGES introduced here.

Support the final step of the SGX2 page removal flow with ioctl() SGX_IOC_ENCLAVE_REMOVE_PAGES. With this ioctl() the user specifies a page range that should be removed. All pages in the provided range should have the SGX_PAGE_TYPE_TRIM page type and the request will fail with EPERM (Operation not permitted) if a page that does not have the correct type is encountered. Page removal can fail on any page within the provided range. Support partial success by returning the number of pages that were successfully removed.

Since actual page removal will succeed even if ENCLU[EACCEPT] was not run from within the enclave the ENCLU[EMODPR] instruction with RWX permissions is used as a no-op mechanism to ensure ENCLU[EACCEPT] was successfully run from within the enclave before the enclave page is removed.

If the user omits running SGX_IOC_ENCLAVE_REMOVE_PAGES the pages will still be removed when the enclave is unloaded.

Reviewed-by: Jarkko Sakkinen jarkko@kernel.org Tested-by: Haitao Huang haitao.huang@intel.com Tested-by: Vijay Dhanraj vijay.dhanraj@intel.com Tested-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Reinette Chatre reinette.chatre@intel.com --- Changes since V4: - Add Haitao's Tested-by tag. - Add Vijay's Tested-by tag. - Add Jarkko's Tested-by tag.

Changes since V3: - Add Jarkko's Reviewed-by tag. - Rename SGX_IOC_ENCLAVE_MODIFY_TYPE to SGX_IOC_ENCLAVE_MODIFY_TYPES. (Jarkko)

Changes since V2: - Adjust ioctl number since removal of SGX_IOC_ENCLAVE_RELAX_PERMISSIONS.

Changes since V1: - Update comments to refer to new ioctl() names SGX_IOC_PAGE_MODT -> SGX_IOC_ENCLAVE_MODIFY_TYPE. - Fix kernel-doc to have () as part of function name. - Change name of ioctl(): SGX_IOC_PAGE_REMOVE -> SGX_IOC_ENCLAVE_REMOVE_PAGES (Jarkko). - With the above name change the page removal ioctl() has its name aligned with existing SGX_IOC_ENCLAVE_ADD_PAGES ioctl(). Also align naming of struct and functions: struct sgx_page_remove -> struct sgx_enclave_remove_pages sgx_page_remove() -> sgx_encl_remove_pages() sgx_ioc_page_remove() -> sgx_ioc_enclave_remove_pages() - Use new SGX2 checking helper. - When loading enclave page, make error code consistent with other instances to help user distinguish between permanent and temporary failures. - Move kernel-doc to function that provides documentation for Documentation/x86/sgx.rst. - Remove redundant comment. - Use offset/length validation utility. - Make explicit which member of struct sgx_enclave_remove_pages is for output (Dave).

arch/x86/include/uapi/asm/sgx.h | 21 +++++ arch/x86/kernel/cpu/sgx/ioctl.c | 145 ++++++++++++++++++++++++++++++++ 2 files changed, 166 insertions(+)

diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h index 567f6166c24a..2dd35bbdc822 100644 --- a/arch/x86/include/uapi/asm/sgx.h +++ b/arch/x86/include/uapi/asm/sgx.h @@ -33,6 +33,8 @@ enum sgx_page_flags { _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 @@ -117,6 +119,25 @@ struct sgx_enclave_modify_types { __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/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c index 9ccafbfc4811..1a2595f261d3 100644 --- a/arch/x86/kernel/cpu/sgx/ioctl.c +++ b/arch/x86/kernel/cpu/sgx/ioctl.c @@ -1071,6 +1071,148 @@ static long sgx_ioc_enclave_modify_types(struct sgx_encl *encl, 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; + + 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(&params, 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, &params); + + if (copy_to_user(arg, &params, 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; @@ -1099,6 +1241,9 @@ long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) 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;

Enclave runtime management is introduced following the pattern of the section describing enclave building. Provide a brief summary of enclave runtime management, pointing to the functions implementing the ioctl()s that will contain details within their kernel-doc.

Reviewed-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Reinette Chatre reinette.chatre@intel.com --- Changes since V4: - Rename sgx_ioc_enclave_modify_type -> sgx_ioc_enclave_modify_types. (Jarkko) - Add Jarkko's Reviewed-by tag.

Changes since V2: - Remove references to ioctl() to relax permissions and update to reflect function renaming sgx_ioc_enclave_restrict_perm() -> sgx_ioc_enclave_restrict_permissions(). - Rename sgx_ioc_enclave_modt -> sgx_ioc_enclave_modify_type

Changes since V1: - New patch.

Documentation/x86/sgx.rst | 15 +++++++++++++++ 1 file changed, 15 insertions(+)

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 ------------

Kernel should not allow permission changes on TCS pages. Add test to confirm this behavior.

Acked-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Reinette Chatre reinette.chatre@intel.com --- No changes since V4.

Changes since V3: - Add Jarkko's Acked-by tag. - User provides only new permissions in SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS ioctl(), replacing secinfo. (Jarkko) - Use SGX page permission bits instead of VMA protection bits.

Changes since V2: - Update to use new struct name struct sgx_enclave_restrict_perm -> struct sgx_enclave_restrict_permissions. (Jarkko)

Changes since V1: - Adapt test to the kernel interface changes: the ioctl() name change and providing entire secinfo as parameter. - Rewrite error path to reduce line lengths.

tools/testing/selftests/sgx/main.c | 71 ++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+)

diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c index 46eac09cd955..016ae3e5f398 100644 --- a/tools/testing/selftests/sgx/main.c +++ b/tools/testing/selftests/sgx/main.c @@ -121,6 +121,24 @@ 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 @@ -567,6 +585,59 @@ 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. *

The test enclave (test_encl.elf) is built with two initialized Thread Control Structures (TCS) included in the binary. Both TCS are initialized with the same entry point, encl_entry, that correctly computes the absolute address of the stack based on the stack of each TCS that is also built into the binary.

A new TCS can be added dynamically to the enclave and requires to be initialized with an entry point used to enter the enclave. Since the existing entry point, encl_entry, assumes that the TCS and its stack exists at particular offsets within the binary it is not able to handle a dynamically added TCS and its stack.

Introduce a new entry point, encl_dyn_entry, that initializes the absolute address of that thread's stack to the address immediately preceding the TCS itself. It is now possible to dynamically add a contiguous memory region to the enclave with the new stack preceding the new TCS. With the new TCS initialized with encl_dyn_entry as entry point the absolute address of the stack is computed correctly on entry.

Acked-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Reinette Chatre reinette.chatre@intel.com --- No changes since V4.

Changes since V3: - Add Jarkko's Acked-by tag.

tools/testing/selftests/sgx/test_encl_bootstrap.S | 6 ++++++ 1 file changed, 6 insertions(+)

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

Support for changing an enclave page's type enables an initialized enclave to be expanded with support for more threads by changing the type of a regular enclave page to that of a Thread Control Structure (TCS). Additionally, being able to change a TCS or regular enclave page's type to be trimmed (SGX_PAGE_TYPE_TRIM) initiates the removal of the page from the enclave.

Test changing page type to TCS as well as page removal flows in two phases: In the first phase support for a new thread is dynamically added to an initialized enclave and in the second phase the pages associated with the new thread are removed from the enclave. As an additional sanity check after the second phase the page used as a TCS page during the first phase is added back as a regular page and ensured that it can be written to (which is not possible if it was a TCS page).

Acked-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Reinette Chatre reinette.chatre@intel.com --- Changes since V4: - Rename struct sgx_enclave_modify_type -> struct sgx_enclave_modify_types. (Jarkko)

Changes since V3: - Add Jarkko's Acked-by tag. - Rename SGX_IOC_ENCLAVE_MODIFY_TYPE to SGX_IOC_ENCLAVE_MODIFY_TYPES. (Jarkko) - User provides just page type to SGX_IOC_ENCLAVE_MODIFY_TYPES ioctl(), replacing secinfo. (Jarkko) - Let the SKIP() call involving SGX_IOC_ENCLAVE_MODIFY_TYPES span two lines to address checkpatch.pl warning triggered by new longer name.

Changes since V2: - Rename struct sgx_enclave_modt -> struct sgx_enclave_modify_type

Changes since V1: - Update to support ioctl() name change (SGX_IOC_PAGE_MODT -> SGX_IOC_ENCLAVE_MODIFY_TYPE) and provide secinfo as parameter instead of just page type (Jarkko). - Update test to reflect page removal ioctl() and struct name change: SGX_IOC_PAGE_REMOVE->SGX_IOC_ENCLAVE_REMOVE_PAGES, struct sgx_page_remove -> struct sgx_enclave_remove_pages (Jarkko). - Use ioctl() instead of ioctl (Dave).

tools/testing/selftests/sgx/load.c | 41 ++++ tools/testing/selftests/sgx/main.c | 343 +++++++++++++++++++++++++++++ tools/testing/selftests/sgx/main.h | 1 + 3 files changed, 385 insertions(+)

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 79c08e347112..8bf43646e0bb 100644 --- a/tools/testing/selftests/sgx/main.c +++ b/tools/testing/selftests/sgx/main.c @@ -1090,4 +1090,347 @@ TEST_F(enclave, augment_via_eaccept) 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); +} + 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);

Removing a page from an initialized enclave involves three steps: (1) the user requests changing the page type to SGX_PAGE_TYPE_TRIM via the SGX_IOC_ENCLAVE_MODIFY_TYPES ioctl(), (2) on success the ENCLU[EACCEPT] instruction is run from within the enclave to accept the page removal, (3) the user initiates the actual removal of the page via the SGX_IOC_ENCLAVE_REMOVE_PAGES ioctl().

Test two possible invalid accesses during the page removal flow: * Test the behavior when a request to remove the page by changing its type to SGX_PAGE_TYPE_TRIM completes successfully but instead of executing ENCLU[EACCEPT] from within the enclave the enclave attempts to read from the page. Even though the page is accessible from the page table entries its type is SGX_PAGE_TYPE_TRIM and thus not accessible according to SGX. The expected behavior is a page fault with the SGX flag set in the error code. * Test the behavior when the page type is changed successfully and ENCLU[EACCEPT] was run from within the enclave. The final ioctl(), SGX_IOC_ENCLAVE_REMOVE_PAGES, is omitted and replaced with an attempt to access the page. Even though the page is accessible from the page table entries its type is SGX_PAGE_TYPE_TRIM and thus not accessible according to SGX. The expected behavior is a page fault with the SGX flag set in the error code.

Acked-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Reinette Chatre reinette.chatre@intel.com --- Changes since V4: - Rename struct sgx_enclave_modify_type -> struct sgx_enclave_modify_types. (Jarkko)

Changes since V3: - Add Jarkko's Acked-by tag. - Rename SGX_IOC_ENCLAVE_MODIFY_TYPE to SGX_IOC_ENCLAVE_MODIFY_TYPES. (Jarkko) - User provides just page type to SGX_IOC_ENCLAVE_MODIFY_TYPES ioctl(), replacing secinfo. (Jarkko) - Let the SKIP() call involving SGX_IOC_ENCLAVE_MODIFY_TYPES span two lines to address checkpatch.pl warning triggered by new longer name.

Changes since V2: - Rename struct sgx_enclave_modt -> struct sgx_enclave_modify_type

Changes since V1: - Update to support ioctl() name change (SGX_IOC_PAGE_MODT -> SGX_IOC_ENCLAVE_MODIFY_TYPE) and provide secinfo as parameter instead of just page type (Jarkko). - Use ioctl() instead of ioctl (Dave).

tools/testing/selftests/sgx/main.c | 243 +++++++++++++++++++++++++++++ 1 file changed, 243 insertions(+)

diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c index 3a82bae915d1..2c69045253b2 100644 --- a/tools/testing/selftests/sgx/main.c +++ b/tools/testing/selftests/sgx/main.c @@ -1547,4 +1547,247 @@ TEST_F(enclave, remove_added_page_no_eaccept) 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_HARNESS_MAIN

Create enclave with additional heap that consumes all physical SGX memory and then remove it.

Depending on the available SGX memory this test could take a significant time to run (several minutes) as it (1) creates the enclave, (2) changes the type of every page to be trimmed, (3) enters the enclave once per page to run EACCEPT, before (4) the pages are finally removed.

Acked-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Reinette Chatre reinette.chatre@intel.com --- Changes since V4: - Rename struct sgx_enclave_modify_type -> struct sgx_enclave_modify_types. (Jarkko)

Changes since V3: - Add Jarkko's Acked-by tag. - Rename SGX_IOC_ENCLAVE_MODIFY_TYPE to SGX_IOC_ENCLAVE_MODIFY_TYPES. (Jarkko) - User provides just page type to SGX_IOC_ENCLAVE_MODIFY_TYPES ioctl(), replacing secinfo. (Jarkko) - Let the SKIP() call involving SGX_IOC_ENCLAVE_MODIFY_TYPES span two lines to address checkpatch.pl warning triggered by new longer name.

Changes since V2: - Rename struct sgx_enclave_modt -> struct sgx_enclave_modify_type

Changes since V1: - Exit test completely on first failure of EACCEPT of a removed page. Since this is an oversubscribed test the number of pages on which this is attempted can be significant and in case of failure the per-page error logging would overwhelm the system. - Update test to call renamed ioctl() (SGX_IOC_PAGE_MODT -> SGX_IOC_ENCLAVE_MODIFY_TYPE) and provide secinfo as parameter (Jarkko). - Fixup definitions to be reverse xmas tree. - Update test to reflect page removal ioctl() and struct name change: SGX_IOC_PAGE_REMOVE->SGX_IOC_ENCLAVE_REMOVE_PAGES, struct sgx_page_remove -> struct sgx_enclave_remove_pages (Jarkko). - Ensure test is skipped when SGX2 not supported by kernel. - Cleanup comments.

tools/testing/selftests/sgx/main.c | 120 +++++++++++++++++++++++++++++ 1 file changed, 120 insertions(+)

diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c index ba16671aef79..9820b3809c69 100644 --- a/tools/testing/selftests/sgx/main.c +++ b/tools/testing/selftests/sgx/main.c @@ -378,7 +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)