diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c index 70fd9aa47c68..7cb9f89ee736 100644 --- a/arch/x86/kernel/cpu/sgx/encl.c +++ b/arch/x86/kernel/cpu/sgx/encl.c @@ -721,7 +721,7 @@ 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); @@ -936,6 +936,49 @@ int sgx_encl_test_and_clear_young(struct mm_struct *mm, return ret; } +/** + * 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 * diff --git a/arch/x86/kernel/cpu/sgx/encl.h b/arch/x86/kernel/cpu/sgx/encl.h index a4894cf3f56a..ed5ced8ccd2c 100644 --- a/arch/x86/kernel/cpu/sgx/encl.h +++ b/arch/x86/kernel/cpu/sgx/encl.h @@ -113,7 +113,7 @@ 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); - +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); void sgx_free_va_slot(struct sgx_va_page *va_page, unsigned int offset); diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index ad453b4387a4..fd786f1bc4e8 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -122,36 +122,9 @@ 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);