efi_loader: open_info in OpenProtocol

efi_open_protocol has to keep track of opened protocols. OpenProtocol enters the agent and controller handle information into this list. A unit test is supplied with a subsequent patch. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Signed-off-by: Alexander Graf <agraf@suse.de>

efi_loader: open_info in OpenProtocol
efi_open_protocol has to keep track of opened protocols. OpenProtocol enters the agent and controller handle information into this list. A unit test is supplied with a subsequent patch. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Signed-off-by: Alexander Graf <agraf@suse.de>
Heinrich Schuchardt · Alexander Graf
1 parent fe1599daf5
Showing 1 changed file with 103 additions and 4 deletions Side-by-side Diff
lib/efi_loader/efi_boottime.c
@@ -2123,6 +2123,101 @@
 /*
  * Open protocol interface on a handle.
  *
+ * @handler		handler of a protocol
+ * @protocol_interface	interface implementing the protocol
+ * @agent_handle	handle of the driver
+ * @controller_handle	handle of the controller
+ * @attributes		attributes indicating how to open the protocol
+ * @return		status code
+ */
+static efi_status_t efi_protocol_open(
+			struct efi_handler *handler,
+			void **protocol_interface, void *agent_handle,
+			void *controller_handle, uint32_t attributes)
+{
+	struct efi_open_protocol_info_item *item;
+	struct efi_open_protocol_info_entry *match = NULL;
+	bool opened_by_driver = false;
+	bool opened_exclusive = false;
+
+	/* If there is no agent, only return the interface */
+	if (!agent_handle)
+		goto out;
+
+	/* For TEST_PROTOCOL ignore interface attribute */
+	if (attributes != EFI_OPEN_PROTOCOL_TEST_PROTOCOL)
+		*protocol_interface = NULL;
+
+	/*
+	 * Check if the protocol is already opened by a driver with the same
+	 * attributes or opened exclusively
+	 */
+	list_for_each_entry(item, &handler->open_infos, link) {
+		if (item->info.agent_handle == agent_handle) {
+			if ((attributes & EFI_OPEN_PROTOCOL_BY_DRIVER) &&
+			    (item->info.attributes == attributes))
+				return EFI_ALREADY_STARTED;
+		}
+		if (item->info.attributes & EFI_OPEN_PROTOCOL_EXCLUSIVE)
+			opened_exclusive = true;
+	}
+
+	/* Only one controller can open the protocol exclusively */
+	if (opened_exclusive && attributes &
+	    (EFI_OPEN_PROTOCOL_EXCLUSIVE | EFI_OPEN_PROTOCOL_BY_DRIVER))
+		return EFI_ACCESS_DENIED;
+
+	/* Prepare exclusive opening */
+	if (attributes & EFI_OPEN_PROTOCOL_EXCLUSIVE) {
+		/* Try to disconnect controllers */
+		list_for_each_entry(item, &handler->open_infos, link) {
+			if (item->info.attributes ==
+					EFI_OPEN_PROTOCOL_BY_DRIVER)
+				EFI_CALL(efi_disconnect_controller(
+						item->info.controller_handle,
+						item->info.agent_handle,
+						NULL));
+		}
+		opened_by_driver = false;
+		/* Check if all controllers are disconnected */
+		list_for_each_entry(item, &handler->open_infos, link) {
+			if (item->info.attributes & EFI_OPEN_PROTOCOL_BY_DRIVER)
+				opened_by_driver = true;
+		}
+		/* Only one controller can be conncected */
+		if (opened_by_driver)
+			return EFI_ACCESS_DENIED;
+	}
+
+	/* Find existing entry */
+	list_for_each_entry(item, &handler->open_infos, link) {
+		if (item->info.agent_handle == agent_handle &&
+		    item->info.controller_handle == controller_handle)
+			match = &item->info;
+	}
+	/* None found, create one */
+	if (!match) {
+		match = efi_create_open_info(handler);
+		if (!match)
+			return EFI_OUT_OF_RESOURCES;
+	}
+
+	match->agent_handle = agent_handle;
+	match->controller_handle = controller_handle;
+	match->attributes = attributes;
+	match->open_count++;
+
+out:
+	/* For TEST_PROTOCOL ignore interface attribute. */
+	if (attributes != EFI_OPEN_PROTOCOL_TEST_PROTOCOL)
+		*protocol_interface = handler->protocol_interface;
+
+	return EFI_SUCCESS;
+}
+
+/*
+ * Open protocol interface on a handle.
+ *
  * This function implements the OpenProtocol interface.
  * See the Unified Extensible Firmware Interface (UEFI) specification
  * for details.
  
  
  
@@ -2161,12 +2256,16 @@
 	case EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER:
 		if (controller_handle == handle)
 			goto out;
+		/* fall-through */
 	case EFI_OPEN_PROTOCOL_BY_DRIVER:
 	case EFI_OPEN_PROTOCOL_BY_DRIVER | EFI_OPEN_PROTOCOL_EXCLUSIVE:
-		if (controller_handle == NULL)
+		/* Check that the controller handle is valid */
+		if (!efi_search_obj(controller_handle))
 			goto out;
+		/* fall-through */
 	case EFI_OPEN_PROTOCOL_EXCLUSIVE:
-		if (agent_handle == NULL)
+		/* Check that the agent handle is valid */
+		if (!efi_search_obj(agent_handle))
 			goto out;
 		break;
 	default:
@@ -2177,8 +2276,8 @@
 	if (r != EFI_SUCCESS)
 		goto out;
  
-	if (attributes != EFI_OPEN_PROTOCOL_TEST_PROTOCOL)
-		*protocol_interface = handler->protocol_interface;
+	r = efi_protocol_open(handler, protocol_interface, agent_handle,
+			      controller_handle, attributes);
 out:
 	return EFI_EXIT(r);
 }
...	...	@@ -2123,6 +2123,101 @@
2123	2123	/*
2124	2124	* Open protocol interface on a handle.
2125	2125	*
	2126	+ * @handler handler of a protocol
	2127	+ * @protocol_interface interface implementing the protocol
	2128	+ * @agent_handle handle of the driver
	2129	+ * @controller_handle handle of the controller
	2130	+ * @attributes attributes indicating how to open the protocol
	2131	+ * @return status code
	2132	+ */
	2133	+static efi_status_t efi_protocol_open(
	2134	+ struct efi_handler *handler,
	2135	+ void *protocol_interface, void agent_handle,
	2136	+ void *controller_handle, uint32_t attributes)
	2137	+{
	2138	+ struct efi_open_protocol_info_item *item;
	2139	+ struct efi_open_protocol_info_entry *match = NULL;
	2140	+ bool opened_by_driver = false;
	2141	+ bool opened_exclusive = false;
	2142	+
	2143	+ /* If there is no agent, only return the interface */
	2144	+ if (!agent_handle)
	2145	+ goto out;
	2146	+
	2147	+ /* For TEST_PROTOCOL ignore interface attribute */
	2148	+ if (attributes != EFI_OPEN_PROTOCOL_TEST_PROTOCOL)
	2149	+ *protocol_interface = NULL;
	2150	+
	2151	+ /*
	2152	+ * Check if the protocol is already opened by a driver with the same
	2153	+ * attributes or opened exclusively
	2154	+ */
	2155	+ list_for_each_entry(item, &handler->open_infos, link) {
	2156	+ if (item->info.agent_handle == agent_handle) {
	2157	+ if ((attributes & EFI_OPEN_PROTOCOL_BY_DRIVER) &&
	2158	+ (item->info.attributes == attributes))
	2159	+ return EFI_ALREADY_STARTED;
	2160	+ }
	2161	+ if (item->info.attributes & EFI_OPEN_PROTOCOL_EXCLUSIVE)
	2162	+ opened_exclusive = true;
	2163	+ }
	2164	+
	2165	+ /* Only one controller can open the protocol exclusively */
	2166	+ if (opened_exclusive && attributes &
	2167	+ (EFI_OPEN_PROTOCOL_EXCLUSIVE \| EFI_OPEN_PROTOCOL_BY_DRIVER))
	2168	+ return EFI_ACCESS_DENIED;
	2169	+
	2170	+ /* Prepare exclusive opening */
	2171	+ if (attributes & EFI_OPEN_PROTOCOL_EXCLUSIVE) {
	2172	+ /* Try to disconnect controllers */
	2173	+ list_for_each_entry(item, &handler->open_infos, link) {
	2174	+ if (item->info.attributes ==
	2175	+ EFI_OPEN_PROTOCOL_BY_DRIVER)
	2176	+ EFI_CALL(efi_disconnect_controller(
	2177	+ item->info.controller_handle,
	2178	+ item->info.agent_handle,
	2179	+ NULL));
	2180	+ }
	2181	+ opened_by_driver = false;
	2182	+ /* Check if all controllers are disconnected */
	2183	+ list_for_each_entry(item, &handler->open_infos, link) {
	2184	+ if (item->info.attributes & EFI_OPEN_PROTOCOL_BY_DRIVER)
	2185	+ opened_by_driver = true;
	2186	+ }
	2187	+ /* Only one controller can be conncected */
	2188	+ if (opened_by_driver)
	2189	+ return EFI_ACCESS_DENIED;
	2190	+ }
	2191	+
	2192	+ /* Find existing entry */
	2193	+ list_for_each_entry(item, &handler->open_infos, link) {
	2194	+ if (item->info.agent_handle == agent_handle &&
	2195	+ item->info.controller_handle == controller_handle)
	2196	+ match = &item->info;
	2197	+ }
	2198	+ /* None found, create one */
	2199	+ if (!match) {
	2200	+ match = efi_create_open_info(handler);
	2201	+ if (!match)
	2202	+ return EFI_OUT_OF_RESOURCES;
	2203	+ }
	2204	+
	2205	+ match->agent_handle = agent_handle;
	2206	+ match->controller_handle = controller_handle;
	2207	+ match->attributes = attributes;
	2208	+ match->open_count++;
	2209	+
	2210	+out:
	2211	+ /* For TEST_PROTOCOL ignore interface attribute. */
	2212	+ if (attributes != EFI_OPEN_PROTOCOL_TEST_PROTOCOL)
	2213	+ *protocol_interface = handler->protocol_interface;
	2214	+
	2215	+ return EFI_SUCCESS;
	2216	+}
	2217	+
	2218	+/*
	2219	+ * Open protocol interface on a handle.
	2220	+ *
2126	2221	* This function implements the OpenProtocol interface.
2127	2222	* See the Unified Extensible Firmware Interface (UEFI) specification
2128	2223	* for details.
2129	2224
2130	2225
2131	2226
...	...	@@ -2161,12 +2256,16 @@
2161	2256	case EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER:
2162	2257	if (controller_handle == handle)
2163	2258	goto out;
	2259	+ /* fall-through */
2164	2260	case EFI_OPEN_PROTOCOL_BY_DRIVER:
2165	2261	case EFI_OPEN_PROTOCOL_BY_DRIVER \| EFI_OPEN_PROTOCOL_EXCLUSIVE:
2166		- if (controller_handle == NULL)
	2262	+ /* Check that the controller handle is valid */
	2263	+ if (!efi_search_obj(controller_handle))
2167	2264	goto out;
	2265	+ /* fall-through */
2168	2266	case EFI_OPEN_PROTOCOL_EXCLUSIVE:
2169		- if (agent_handle == NULL)
	2267	+ /* Check that the agent handle is valid */
	2268	+ if (!efi_search_obj(agent_handle))
2170	2269	goto out;
2171	2270	break;
2172	2271	default:
...	...	@@ -2177,8 +2276,8 @@
2177	2276	if (r != EFI_SUCCESS)
2178	2277	goto out;
2179	2278
2180		- if (attributes != EFI_OPEN_PROTOCOL_TEST_PROTOCOL)
2181		- *protocol_interface = handler->protocol_interface;
	2279	+ r = efi_protocol_open(handler, protocol_interface, agent_handle,
	2280	+ controller_handle, attributes);
2182	2281	out:
2183	2282	return EFI_EXIT(r);
2184	2283	}