@@ -587,7 +587,7 @@ 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);
@@ -776,6 +776,49 @@ 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
*
@@ -111,7 +111,7 @@ int sgx_encl_get_backing(struct sgx_encl *encl, unsigned long page_index,
void sgx_encl_put_backing(struct sgx_backing *backing, bool do_write);
int sgx_encl_test_and_clear_young(struct mm_struct *mm,
struct sgx_encl_page *page);
-
+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);
@@ -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;
-
- 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);
- }
+ int ret;
- 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);