efi_selftest: ReinstallProtocolInterface test

Test ReinstallProtocolInterface() more rigorously.

Replacing the sole installed protocol interface must not result in deleting
the handle and creating a new one.

Check which interface is actually installed before and after
ReinstallProtocolInterface().

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/lib/efi_selftest/efi_selftest_register_notify.c b/lib/efi_selftest/efi_selftest_register_notify.c
index ad4bcce..adf5dd0 100644
--- a/lib/efi_selftest/efi_selftest_register_notify.c
+++ b/lib/efi_selftest/efi_selftest_register_notify.c
@@ -124,6 +124,7 @@
 {
 	efi_status_t ret;
 	efi_handle_t handle1 = NULL, handle2 = NULL;
+	struct interface *interface;
 	struct interface interface1, interface2;
 
 	ret = boottime->install_protocol_interface(&handle1, &guid1,
@@ -145,6 +146,18 @@
 		efi_st_error("LocateHandle failed\n");
 		return EFI_ST_FAILURE;
 	}
+	interface = NULL;
+	ret = boottime->open_protocol(handle1, &guid1, (void**)&interface,
+				      NULL, NULL,
+				      EFI_OPEN_PROTOCOL_GET_PROTOCOL);
+	if (ret != EFI_SUCCESS) {
+		efi_st_error("Cannot find installed protocol on handle\n");
+		return EFI_ST_FAILURE;
+	}
+	if (interface != &interface1) {
+		efi_st_error("Wrong interface after install\n");
+		return EFI_ST_FAILURE;
+	}
 	ret = boottime->free_pool(context.handles);
 	if (ret != EFI_SUCCESS) {
 		efi_st_error("FreePool failed\n");
@@ -186,6 +199,18 @@
 		efi_st_error("FreePool failed\n");
 		return EFI_ST_FAILURE;
 	}
+	interface = NULL;
+	ret = boottime->open_protocol(handle1, &guid1, (void**)&interface,
+				      NULL, NULL,
+				      EFI_OPEN_PROTOCOL_GET_PROTOCOL);
+	if (ret != EFI_SUCCESS) {
+		efi_st_error("Cannot find reinstalled protocol on handle\n");
+		return EFI_ST_FAILURE;
+	}
+	if (interface != &interface2) {
+		efi_st_error("Wrong interface after reinstall\n");
+		return EFI_ST_FAILURE;
+	}
 	context.notify_count = 0;
 	ret = boottime->install_protocol_interface(&handle2, &guid1,
 						   EFI_NATIVE_INTERFACE,