Kernel 4.20 and later: vmf_insert_pfn returns VM_FAULT_NOPAGE

in success case Signed-off-by: Serge Ayoun <[email protected]>
pmpleader · Feb 5, 2019 · 56b7f9e · 56b7f9e
1 parent 982c6e3
commit 56b7f9e
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Showing 3 changed files with 8 additions and 3 deletions.
diff --git a/sgx_encl.c b/sgx_encl.c
@@ -252,10 +252,11 @@ static bool sgx_process_add_page_req(struct sgx_add_page_req *req,
 
 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 20, 0))
 	ret = vmf_insert_pfn(vma, encl_page->addr, PFN_DOWN(epc_page->pa));
+	if (ret != VM_FAULT_NOPAGE) {
 #else
 	ret = vm_insert_pfn(vma, encl_page->addr, PFN_DOWN(epc_page->pa));
-#endif
 	if (ret) {
+#endif
 		sgx_put_backing(backing, 0);
 		return false;
 	}

diff --git a/sgx_encl2.c b/sgx_encl2.c
@@ -171,12 +171,15 @@ struct sgx_encl_page *sgx_encl_augment(struct vm_area_struct *vma,
 
 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 20, 0))
 	ret = vmf_insert_pfn(vma, encl_page->addr, PFN_DOWN(epc_page->pa));
+	sgx_put_page(epc_va);
+	sgx_put_page(secs_va);
+	if (ret != VM_FAULT_NOPAGE) {
 #else
 	ret = vm_insert_pfn(vma, encl_page->addr, PFN_DOWN(epc_page->pa));
-#endif
 	sgx_put_page(epc_va);
 	sgx_put_page(secs_va);
 	if (ret) {
+#endif
 		pr_err("sgx: vm_insert_pfn failure with ret=%d\n", ret);
 		goto out;
 	}

diff --git a/sgx_util.c b/sgx_util.c
@@ -321,10 +321,11 @@ static struct sgx_encl_page *sgx_do_fault(struct vm_area_struct *vma,
 
 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 20, 0))
 	rc = vmf_insert_pfn(vma, entry->addr, PFN_DOWN(entry->epc_page->pa));
+	if (rc != VM_FAULT_NOPAGE) {
 #else
 	rc = vm_insert_pfn(vma, entry->addr, PFN_DOWN(entry->epc_page->pa));
-#endif
 	if (rc) {
+#endif
 		/* Kill the enclave if vm_insert_pfn fails; failure only occurs
 		 * if there is a driver bug or an unrecoverable issue, e.g. OOM.
 		 */