Merge tag 'efi-2019-07-rc3-3' of git://git.denx.de/u-boot-efi
[oweals/u-boot.git] / lib / efi_loader / efi_boottime.c
index b215bd7723da5a92865de778b34b9c3dafaec7fe..54fff85e64efff2e0dc49160331aa8e689b352bc 100644 (file)
@@ -13,6 +13,7 @@
 #include <linux/libfdt_env.h>
 #include <u-boot/crc.h>
 #include <bootm.h>
+#include <pe.h>
 #include <watchdog.h>
 
 DECLARE_GLOBAL_DATA_PTR;
@@ -26,6 +27,9 @@ LIST_HEAD(efi_obj_list);
 /* List of all events */
 LIST_HEAD(efi_events);
 
+/* List of all events registered by RegisterProtocolNotify() */
+LIST_HEAD(efi_register_notify_events);
+
 /* Handle of the currently executing image */
 static efi_handle_t current_image;
 
@@ -177,10 +181,12 @@ static void efi_queue_event(struct efi_event *event, bool check_tpl)
                /* Check TPL */
                if (check_tpl && efi_tpl >= event->notify_tpl)
                        return;
+               event->is_queued = false;
                EFI_CALL_VOID(event->notify_function(event,
                                                     event->notify_context));
+       } else {
+               event->is_queued = false;
        }
-       event->is_queued = false;
 }
 
 /**
@@ -238,7 +244,7 @@ void efi_signal_event(struct efi_event *event, bool check_tpl)
                        if (evt->is_queued)
                                efi_queue_event(evt, check_tpl);
                }
-       } else if (!event->is_signaled) {
+       } else {
                event->is_signaled = true;
                if (event->type & EVT_NOTIFY_SIGNAL)
                        efi_queue_event(event, check_tpl);
@@ -263,7 +269,7 @@ static unsigned long EFIAPI efi_raise_tpl(efi_uintn_t new_tpl)
        EFI_ENTRY("0x%zx", new_tpl);
 
        if (new_tpl < efi_tpl)
-               debug("WARNING: new_tpl < current_tpl in %s\n", __func__);
+               EFI_PRINT("WARNING: new_tpl < current_tpl in %s\n", __func__);
        efi_tpl = new_tpl;
        if (efi_tpl > TPL_HIGH_LEVEL)
                efi_tpl = TPL_HIGH_LEVEL;
@@ -286,7 +292,7 @@ static void EFIAPI efi_restore_tpl(efi_uintn_t old_tpl)
        EFI_ENTRY("0x%zx", old_tpl);
 
        if (old_tpl > efi_tpl)
-               debug("WARNING: old_tpl > current_tpl in %s\n", __func__);
+               EFI_PRINT("WARNING: old_tpl > current_tpl in %s\n", __func__);
        efi_tpl = old_tpl;
        if (efi_tpl > TPL_HIGH_LEVEL)
                efi_tpl = TPL_HIGH_LEVEL;
@@ -423,10 +429,12 @@ static efi_status_t EFIAPI efi_free_pool_ext(void *buffer)
 }
 
 /**
- * efi_add_handle() - add a new object to the object list
- * @obj: object to be added
+ * efi_add_handle() - add a new handle to the object list
+ *
+ * @handle:    handle to be added
  *
- * The protocols list is initialized. The object handle is set.
+ * The protocols list is initialized. The handle is added to the list of known
+ * UEFI objects.
  */
 void efi_add_handle(efi_handle_t handle)
 {
@@ -507,10 +515,8 @@ efi_status_t efi_remove_protocol(const efi_handle_t handle,
        ret = efi_search_protocol(handle, protocol, &handler);
        if (ret != EFI_SUCCESS)
                return ret;
-       if (guidcmp(handler->guid, protocol))
-               return EFI_INVALID_PARAMETER;
        if (handler->protocol_interface != protocol_interface)
-               return EFI_INVALID_PARAMETER;
+               return EFI_NOT_FOUND;
        list_del(&handler->link);
        free(handler);
        return EFI_SUCCESS;
@@ -618,7 +624,7 @@ efi_status_t efi_create_event(uint32_t type, efi_uintn_t notify_tpl,
        }
 
        if ((type & (EVT_NOTIFY_WAIT | EVT_NOTIFY_SIGNAL)) &&
-           (is_valid_tpl(notify_tpl) != EFI_SUCCESS))
+           (!notify_function || is_valid_tpl(notify_tpl) != EFI_SUCCESS))
                return EFI_INVALID_PARAMETER;
 
        evt = calloc(1, sizeof(struct efi_event));
@@ -662,10 +668,26 @@ efi_status_t EFIAPI efi_create_event_ex(uint32_t type, efi_uintn_t notify_tpl,
                                        efi_guid_t *event_group,
                                        struct efi_event **event)
 {
+       efi_status_t ret;
+
        EFI_ENTRY("%d, 0x%zx, %p, %p, %pUl", type, notify_tpl, notify_function,
                  notify_context, event_group);
-       return EFI_EXIT(efi_create_event(type, notify_tpl, notify_function,
-                                        notify_context, event_group, event));
+
+       /*
+        * The allowable input parameters are the same as in CreateEvent()
+        * except for the following two disallowed event types.
+        */
+       switch (type) {
+       case EVT_SIGNAL_EXIT_BOOT_SERVICES:
+       case EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE:
+               ret = EFI_INVALID_PARAMETER;
+               goto out;
+       }
+
+       ret = efi_create_event(type, notify_tpl, notify_function,
+                              notify_context, event_group, event);
+out:
+       return EFI_EXIT(ret);
 }
 
 /**
@@ -889,9 +911,21 @@ static efi_status_t EFIAPI efi_signal_event_ext(struct efi_event *event)
  */
 static efi_status_t EFIAPI efi_close_event(struct efi_event *event)
 {
+       struct efi_register_notify_event *item, *next;
+
        EFI_ENTRY("%p", event);
        if (efi_is_event(event) != EFI_SUCCESS)
                return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+       /* Remove protocol notify registrations for the event */
+       list_for_each_entry_safe(item, next, &efi_register_notify_events,
+                                link) {
+               if (event == item->event) {
+                       list_del(&item->link);
+                       free(item);
+               }
+       }
+
        list_del(&event->link);
        free(event);
        return EFI_EXIT(EFI_SUCCESS);
@@ -937,11 +971,13 @@ struct efi_object *efi_search_obj(const efi_handle_t handle)
 {
        struct efi_object *efiobj;
 
+       if (!handle)
+               return NULL;
+
        list_for_each_entry(efiobj, &efi_obj_list, link) {
                if (efiobj == handle)
                        return efiobj;
        }
-
        return NULL;
 }
 
@@ -995,6 +1031,7 @@ efi_status_t efi_add_protocol(const efi_handle_t handle,
        struct efi_object *efiobj;
        struct efi_handler *handler;
        efi_status_t ret;
+       struct efi_register_notify_event *event;
 
        efiobj = efi_search_obj(handle);
        if (!efiobj)
@@ -1009,6 +1046,13 @@ efi_status_t efi_add_protocol(const efi_handle_t handle,
        handler->protocol_interface = protocol_interface;
        INIT_LIST_HEAD(&handler->open_infos);
        list_add_tail(&handler->link, &efiobj->protocols);
+
+       /* Notify registered events */
+       list_for_each_entry(event, &efi_register_notify_events, link) {
+               if (!guidcmp(protocol, &event->protocol))
+                       efi_signal_event(event->event, true);
+       }
+
        if (!guidcmp(&efi_guid_device_path, protocol))
                EFI_PRINT("installed device path '%pD'\n", protocol_interface);
        return EFI_SUCCESS;
@@ -1049,11 +1093,9 @@ static efi_status_t EFIAPI efi_install_protocol_interface(
                r = efi_create_handle(handle);
                if (r != EFI_SUCCESS)
                        goto out;
-               debug("%sEFI: new handle %p\n", indent_string(nesting_level),
-                     *handle);
+               EFI_PRINT("new handle %p\n", *handle);
        } else {
-               debug("%sEFI: handle %p\n", indent_string(nesting_level),
-                     *handle);
+               EFI_PRINT("handle %p\n", *handle);
        }
        /* Add new protocol */
        r = efi_add_protocol(*handle, protocol, protocol_interface);
@@ -1272,8 +1314,30 @@ static efi_status_t EFIAPI efi_register_protocol_notify(
                                                struct efi_event *event,
                                                void **registration)
 {
+       struct efi_register_notify_event *item;
+       efi_status_t ret = EFI_SUCCESS;
+
        EFI_ENTRY("%pUl, %p, %p", protocol, event, registration);
-       return EFI_EXIT(EFI_OUT_OF_RESOURCES);
+
+       if (!protocol || !event || !registration) {
+               ret = EFI_INVALID_PARAMETER;
+               goto out;
+       }
+
+       item = calloc(1, sizeof(struct efi_register_notify_event));
+       if (!item) {
+               ret = EFI_OUT_OF_RESOURCES;
+               goto out;
+       }
+
+       item->event = event;
+       memcpy(&item->protocol, protocol, sizeof(efi_guid_t));
+
+       list_add_tail(&item->link, &efi_register_notify_events);
+
+       *registration = item;
+out:
+       return EFI_EXIT(ret);
 }
 
 /**
@@ -1288,8 +1352,7 @@ static efi_status_t EFIAPI efi_register_protocol_notify(
  * Return: 0 if the handle implements the protocol
  */
 static int efi_search(enum efi_locate_search_type search_type,
-                     const efi_guid_t *protocol, void *search_key,
-                     efi_handle_t handle)
+                     const efi_guid_t *protocol, efi_handle_t handle)
 {
        efi_status_t ret;
 
@@ -1297,8 +1360,6 @@ static int efi_search(enum efi_locate_search_type search_type,
        case ALL_HANDLES:
                return 0;
        case BY_REGISTER_NOTIFY:
-               /* TODO: RegisterProtocolNotify is not implemented yet */
-               return -1;
        case BY_PROTOCOL:
                ret = efi_search_protocol(handle, protocol, NULL);
                return (ret != EFI_SUCCESS);
@@ -1310,11 +1371,12 @@ static int efi_search(enum efi_locate_search_type search_type,
 
 /**
  * efi_locate_handle() - locate handles implementing a protocol
- * @search_type: selection criterion
- * @protocol:    GUID of the protocol
- * @search_key: registration key
- * @buffer_size: size of the buffer to receive the handles in bytes
- * @buffer:      buffer to receive the relevant handles
+ *
+ * @search_type:       selection criterion
+ * @protocol:          GUID of the protocol
+ * @search_key:                registration key
+ * @buffer_size:       size of the buffer to receive the handles in bytes
+ * @buffer:            buffer to receive the relevant handles
  *
  * This function is meant for U-Boot internal calls. For the API implementation
  * of the LocateHandle service see efi_locate_handle_ext.
@@ -1328,6 +1390,7 @@ static efi_status_t efi_locate_handle(
 {
        struct efi_object *efiobj;
        efi_uintn_t size = 0;
+       struct efi_register_notify_event *item, *event = NULL;
 
        /* Check parameters */
        switch (search_type) {
@@ -1336,8 +1399,19 @@ static efi_status_t efi_locate_handle(
        case BY_REGISTER_NOTIFY:
                if (!search_key)
                        return EFI_INVALID_PARAMETER;
-               /* RegisterProtocolNotify is not implemented yet */
-               return EFI_UNSUPPORTED;
+               /* Check that the registration key is valid */
+               list_for_each_entry(item, &efi_register_notify_events, link) {
+                       if (item ==
+                           (struct efi_register_notify_event *)search_key) {
+                               event = item;
+                               break;
+                       }
+               }
+               if (!event)
+                       return EFI_INVALID_PARAMETER;
+
+               protocol = &event->protocol;
+               break;
        case BY_PROTOCOL:
                if (!protocol)
                        return EFI_INVALID_PARAMETER;
@@ -1346,32 +1420,32 @@ static efi_status_t efi_locate_handle(
                return EFI_INVALID_PARAMETER;
        }
 
-       /*
-        * efi_locate_handle_buffer uses this function for
-        * the calculation of the necessary buffer size.
-        * So do not require a buffer for buffersize == 0.
-        */
-       if (!buffer_size || (*buffer_size && !buffer))
-               return EFI_INVALID_PARAMETER;
-
        /* Count how much space we need */
        list_for_each_entry(efiobj, &efi_obj_list, link) {
-               if (!efi_search(search_type, protocol, search_key, efiobj))
+               if (!efi_search(search_type, protocol, efiobj))
                        size += sizeof(void *);
        }
 
+       if (size == 0)
+               return EFI_NOT_FOUND;
+
+       if (!buffer_size)
+               return EFI_INVALID_PARAMETER;
+
        if (*buffer_size < size) {
                *buffer_size = size;
                return EFI_BUFFER_TOO_SMALL;
        }
 
        *buffer_size = size;
-       if (size == 0)
-               return EFI_NOT_FOUND;
+
+       /* The buffer size is sufficient but there is no buffer */
+       if (!buffer)
+               return EFI_INVALID_PARAMETER;
 
        /* Then fill the array */
        list_for_each_entry(efiobj, &efi_obj_list, link) {
-               if (!efi_search(search_type, protocol, search_key, efiobj))
+               if (!efi_search(search_type, protocol, efiobj))
                        *buffer++ = efiobj;
        }
 
@@ -1536,6 +1610,7 @@ efi_status_t efi_setup_loaded_image(struct efi_device_path *device_path,
                free(info);
                return EFI_OUT_OF_RESOURCES;
        }
+       obj->header.type = EFI_OBJECT_TYPE_LOADED_IMAGE;
 
        /* Add internal object to object list */
        efi_add_handle(&obj->header);
@@ -1569,26 +1644,6 @@ efi_status_t efi_setup_loaded_image(struct efi_device_path *device_path,
        if (ret != EFI_SUCCESS)
                goto failure;
 
-#if CONFIG_IS_ENABLED(EFI_LOADER_HII)
-       ret = efi_add_protocol(&obj->header,
-                              &efi_guid_hii_string_protocol,
-                              (void *)&efi_hii_string);
-       if (ret != EFI_SUCCESS)
-               goto failure;
-
-       ret = efi_add_protocol(&obj->header,
-                              &efi_guid_hii_database_protocol,
-                              (void *)&efi_hii_database);
-       if (ret != EFI_SUCCESS)
-               goto failure;
-
-       ret = efi_add_protocol(&obj->header,
-                              &efi_guid_hii_config_routing_protocol,
-                              (void *)&efi_hii_config_routing);
-       if (ret != EFI_SUCCESS)
-               goto failure;
-#endif
-
        *info_ptr = info;
        *handle_ptr = obj;
 
@@ -1611,6 +1666,7 @@ failure:
  * @size:      size of the loaded image
  * Return:     status code
  */
+static
 efi_status_t efi_load_image_from_path(struct efi_device_path *file_path,
                                      void **buffer, efi_uintn_t *size)
 {
@@ -1704,7 +1760,7 @@ efi_status_t EFIAPI efi_load_image(bool boot_policy,
        EFI_ENTRY("%d, %p, %pD, %p, %zd, %p", boot_policy, parent_image,
                  file_path, source_buffer, source_size, image_handle);
 
-       if (!image_handle || !parent_image) {
+       if (!image_handle || !efi_search_obj(parent_image)) {
                ret = EFI_INVALID_PARAMETER;
                goto error;
        }
@@ -1713,25 +1769,26 @@ efi_status_t EFIAPI efi_load_image(bool boot_policy,
                ret = EFI_NOT_FOUND;
                goto error;
        }
+       /* The parent image handle must refer to a loaded image */
+       if (!parent_image->type) {
+               ret = EFI_INVALID_PARAMETER;
+               goto error;
+       }
 
        if (!source_buffer) {
                ret = efi_load_image_from_path(file_path, &dest_buffer,
                                               &source_size);
                if (ret != EFI_SUCCESS)
                        goto error;
-               /*
-                * split file_path which contains both the device and
-                * file parts:
-                */
-               efi_dp_split_file_path(file_path, &dp, &fp);
        } else {
-               /* In this case, file_path is the "device" path, i.e.
-                * something like a HARDWARE_DEVICE:MEMORY_MAPPED
-                */
+               if (!source_size) {
+                       ret = EFI_LOAD_ERROR;
+                       goto error;
+               }
                dest_buffer = source_buffer;
-               dp = file_path;
-               fp = NULL;
        }
+       /* split file_path which contains both the device and file parts */
+       efi_dp_split_file_path(file_path, &dp, &fp);
        ret = efi_setup_loaded_image(dp, fp, image_obj, &info);
        if (ret == EFI_SUCCESS)
                ret = efi_load_pe(*image_obj, dest_buffer, info);
@@ -1752,29 +1809,6 @@ error:
        return EFI_EXIT(ret);
 }
 
-/**
- * efi_unload_image() - unload an EFI image
- * @image_handle: handle of the image to be unloaded
- *
- * This function implements the UnloadImage service.
- *
- * See the Unified Extensible Firmware Interface (UEFI) specification for
- * details.
- *
- * Return: status code
- */
-efi_status_t EFIAPI efi_unload_image(efi_handle_t image_handle)
-{
-       struct efi_object *efiobj;
-
-       EFI_ENTRY("%p", image_handle);
-       efiobj = efi_search_obj(image_handle);
-       if (efiobj)
-               list_del(&efiobj->link);
-
-       return EFI_EXIT(EFI_SUCCESS);
-}
-
 /**
  * efi_exit_caches() - fix up caches for EFI payloads if necessary
  */
@@ -1807,11 +1841,11 @@ static void efi_exit_caches(void)
  * Return: status code
  */
 static efi_status_t EFIAPI efi_exit_boot_services(efi_handle_t image_handle,
-                                                 unsigned long map_key)
+                                                 efi_uintn_t map_key)
 {
        struct efi_event *evt;
 
-       EFI_ENTRY("%p, %ld", image_handle, map_key);
+       EFI_ENTRY("%p, %zx", image_handle, map_key);
 
        /* Check that the caller has read the current memory map */
        if (map_key != efi_memory_map_key)
@@ -1882,10 +1916,17 @@ static efi_status_t EFIAPI efi_exit_boot_services(efi_handle_t image_handle,
 static efi_status_t EFIAPI efi_get_next_monotonic_count(uint64_t *count)
 {
        static uint64_t mono;
+       efi_status_t ret;
 
        EFI_ENTRY("%p", count);
+       if (!count) {
+               ret = EFI_INVALID_PARAMETER;
+               goto out;
+       }
        *count = mono++;
-       return EFI_EXIT(EFI_SUCCESS);
+       ret = EFI_SUCCESS;
+out:
+       return EFI_EXIT(ret);
 }
 
 /**
@@ -1957,7 +1998,8 @@ static efi_status_t EFIAPI efi_close_protocol(efi_handle_t handle,
        EFI_ENTRY("%p, %pUl, %p, %p", handle, protocol, agent_handle,
                  controller_handle);
 
-       if (!agent_handle) {
+       if (!efi_search_obj(agent_handle) ||
+           (controller_handle && !efi_search_obj(controller_handle))) {
                r = EFI_INVALID_PARAMETER;
                goto out;
        }
@@ -2226,7 +2268,7 @@ static efi_status_t EFIAPI efi_locate_device_path(
 
        EFI_ENTRY("%pUl, %p, %p", protocol, device_path, device);
 
-       if (!protocol || !device_path || !*device_path || !device) {
+       if (!protocol || !device_path || !*device_path) {
                ret = EFI_INVALID_PARAMETER;
                goto out;
        }
@@ -2259,6 +2301,10 @@ static efi_status_t EFIAPI efi_locate_device_path(
                /* Check if dp is a subpath of device_path */
                if (memcmp(*device_path, dp, len_dp))
                        continue;
+               if (!device) {
+                       ret = EFI_INVALID_PARAMETER;
+                       goto out;
+               }
                *device = handles[i];
                len_best = len_dp;
        }
@@ -2287,7 +2333,7 @@ out:
  *
  * Return: status code
  */
-static efi_status_t EFIAPI efi_install_multiple_protocol_interfaces
+efi_status_t EFIAPI efi_install_multiple_protocol_interfaces
                                (efi_handle_t *handle, ...)
 {
        EFI_ENTRY("%p", handle);
@@ -2295,6 +2341,7 @@ static efi_status_t EFIAPI efi_install_multiple_protocol_interfaces
        efi_va_list argptr;
        const efi_guid_t *protocol;
        void *protocol_interface;
+       efi_handle_t old_handle;
        efi_status_t r = EFI_SUCCESS;
        int i = 0;
 
@@ -2307,6 +2354,20 @@ static efi_status_t EFIAPI efi_install_multiple_protocol_interfaces
                if (!protocol)
                        break;
                protocol_interface = efi_va_arg(argptr, void*);
+               /* Check that a device path has not been installed before */
+               if (!guidcmp(protocol, &efi_guid_device_path)) {
+                       struct efi_device_path *dp = protocol_interface;
+
+                       r = EFI_CALL(efi_locate_device_path(protocol, &dp,
+                                                           &old_handle));
+                       if (r == EFI_SUCCESS &&
+                           dp->type == DEVICE_PATH_TYPE_END) {
+                               EFI_PRINT("Path %pD already installed\n",
+                                         protocol_interface);
+                               r = EFI_ALREADY_STARTED;
+                               break;
+                       }
+               }
                r = EFI_CALL(efi_install_protocol_interface(
                                                handle, protocol,
                                                EFI_NATIVE_INTERFACE,
@@ -2414,9 +2475,16 @@ static efi_status_t EFIAPI efi_calculate_crc32(const void *data,
                                               efi_uintn_t data_size,
                                               u32 *crc32_p)
 {
+       efi_status_t ret = EFI_SUCCESS;
+
        EFI_ENTRY("%p, %zu", data, data_size);
+       if (!data || !data_size || !crc32_p) {
+               ret = EFI_INVALID_PARAMETER;
+               goto out;
+       }
        *crc32_p = crc32(0, data, data_size);
-       return EFI_EXIT(EFI_SUCCESS);
+out:
+       return EFI_EXIT(ret);
 }
 
 /**
@@ -2610,8 +2678,15 @@ static efi_status_t EFIAPI efi_open_protocol
        }
 
        r = efi_search_protocol(handle, protocol, &handler);
-       if (r != EFI_SUCCESS)
+       switch (r) {
+       case EFI_SUCCESS:
+               break;
+       case EFI_NOT_FOUND:
+               r = EFI_UNSUPPORTED;
                goto out;
+       default:
+               goto out;
+       }
 
        r = efi_protocol_open(handler, protocol_interface, agent_handle,
                              controller_handle, attributes);
@@ -2653,6 +2728,9 @@ efi_status_t EFIAPI efi_start_image(efi_handle_t image_handle,
 
        efi_is_direct_boot = false;
 
+       image_obj->exit_data_size = exit_data_size;
+       image_obj->exit_data = exit_data;
+
        /* call the image! */
        if (setjmp(&image_obj->exit_jmp)) {
                /*
@@ -2675,15 +2753,16 @@ efi_status_t EFIAPI efi_start_image(efi_handle_t image_handle,
                 * missed out steps of EFI_CALL.
                 */
                assert(__efi_entry_check());
-               debug("%sEFI: %lu returned by started image\n",
-                     __efi_nesting_dec(),
-                     (unsigned long)((uintptr_t)image_obj->exit_status &
-                                     ~EFI_ERROR_MASK));
+               EFI_PRINT("%lu returned by started image\n",
+                         (unsigned long)((uintptr_t)image_obj->exit_status &
+                         ~EFI_ERROR_MASK));
                current_image = parent_image;
                return EFI_EXIT(image_obj->exit_status);
        }
 
        current_image = image_handle;
+       image_obj->header.type = EFI_OBJECT_TYPE_STARTED_IMAGE;
+       EFI_PRINT("Jumping into 0x%p\n", image_obj->entry);
        ret = EFI_CALL(image_obj->entry(image_handle, &systab));
 
        /*
@@ -2695,6 +2774,111 @@ efi_status_t EFIAPI efi_start_image(efi_handle_t image_handle,
        return EFI_CALL(systab.boottime->exit(image_handle, ret, 0, NULL));
 }
 
+/**
+ * efi_delete_image() - delete loaded image from memory)
+ *
+ * @image_obj:                 handle of the loaded image
+ * @loaded_image_protocol:     loaded image protocol
+ */
+static void efi_delete_image(struct efi_loaded_image_obj *image_obj,
+                            struct efi_loaded_image *loaded_image_protocol)
+{
+       efi_free_pages((uintptr_t)loaded_image_protocol->image_base,
+                      efi_size_in_pages(loaded_image_protocol->image_size));
+       efi_delete_handle(&image_obj->header);
+}
+
+/**
+ * efi_unload_image() - unload an EFI image
+ * @image_handle: handle of the image to be unloaded
+ *
+ * This function implements the UnloadImage service.
+ *
+ * See the Unified Extensible Firmware Interface (UEFI) specification for
+ * details.
+ *
+ * Return: status code
+ */
+efi_status_t EFIAPI efi_unload_image(efi_handle_t image_handle)
+{
+       efi_status_t ret = EFI_SUCCESS;
+       struct efi_object *efiobj;
+       struct efi_loaded_image *loaded_image_protocol;
+
+       EFI_ENTRY("%p", image_handle);
+
+       efiobj = efi_search_obj(image_handle);
+       if (!efiobj) {
+               ret = EFI_INVALID_PARAMETER;
+               goto out;
+       }
+       /* Find the loaded image protocol */
+       ret = EFI_CALL(efi_open_protocol(image_handle, &efi_guid_loaded_image,
+                                        (void **)&loaded_image_protocol,
+                                        NULL, NULL,
+                                        EFI_OPEN_PROTOCOL_GET_PROTOCOL));
+       if (ret != EFI_SUCCESS) {
+               ret = EFI_INVALID_PARAMETER;
+               goto out;
+       }
+       switch (efiobj->type) {
+       case EFI_OBJECT_TYPE_STARTED_IMAGE:
+               /* Call the unload function */
+               if (!loaded_image_protocol->unload) {
+                       ret = EFI_UNSUPPORTED;
+                       goto out;
+               }
+               ret = EFI_CALL(loaded_image_protocol->unload(image_handle));
+               if (ret != EFI_SUCCESS)
+                       goto out;
+               break;
+       case EFI_OBJECT_TYPE_LOADED_IMAGE:
+               break;
+       default:
+               ret = EFI_INVALID_PARAMETER;
+               goto out;
+       }
+       efi_delete_image((struct efi_loaded_image_obj *)efiobj,
+                        loaded_image_protocol);
+out:
+       return EFI_EXIT(ret);
+}
+
+/**
+ * efi_update_exit_data() - fill exit data parameters of StartImage()
+ *
+ * @image_obj          image handle
+ * @exit_data_size     size of the exit data buffer
+ * @exit_data          buffer with data returned by UEFI payload
+ * Return:             status code
+ */
+static efi_status_t efi_update_exit_data(struct efi_loaded_image_obj *image_obj,
+                                        efi_uintn_t exit_data_size,
+                                        u16 *exit_data)
+{
+       efi_status_t ret;
+
+       /*
+        * If exit_data is not provided to StartImage(), exit_data_size must be
+        * ignored.
+        */
+       if (!image_obj->exit_data)
+               return EFI_SUCCESS;
+       if (image_obj->exit_data_size)
+               *image_obj->exit_data_size = exit_data_size;
+       if (exit_data_size && exit_data) {
+               ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA,
+                                       exit_data_size,
+                                       (void **)image_obj->exit_data);
+               if (ret != EFI_SUCCESS)
+                       return ret;
+               memcpy(*image_obj->exit_data, exit_data, exit_data_size);
+       } else {
+               image_obj->exit_data = NULL;
+       }
+       return EFI_SUCCESS;
+}
+
 /**
  * efi_exit() - leave an EFI application or driver
  * @image_handle:   handle of the application or driver that is exiting
@@ -2719,7 +2903,7 @@ static efi_status_t EFIAPI efi_exit(efi_handle_t image_handle,
         *       image protocol.
         */
        efi_status_t ret;
-       void *info;
+       struct efi_loaded_image *loaded_image_protocol;
        struct efi_loaded_image_obj *image_obj =
                (struct efi_loaded_image_obj *)image_handle;
 
@@ -2727,13 +2911,45 @@ static efi_status_t EFIAPI efi_exit(efi_handle_t image_handle,
                  exit_data_size, exit_data);
 
        /* Check parameters */
-       if (image_handle != current_image)
-               goto out;
        ret = EFI_CALL(efi_open_protocol(image_handle, &efi_guid_loaded_image,
-                                        &info, NULL, NULL,
+                                        (void **)&loaded_image_protocol,
+                                        NULL, NULL,
                                         EFI_OPEN_PROTOCOL_GET_PROTOCOL));
-       if (ret != EFI_SUCCESS)
+       if (ret != EFI_SUCCESS) {
+               ret = EFI_INVALID_PARAMETER;
+               goto out;
+       }
+
+       /* Unloading of unstarted images */
+       switch (image_obj->header.type) {
+       case EFI_OBJECT_TYPE_STARTED_IMAGE:
+               break;
+       case EFI_OBJECT_TYPE_LOADED_IMAGE:
+               efi_delete_image(image_obj, loaded_image_protocol);
+               ret = EFI_SUCCESS;
+               goto out;
+       default:
+               /* Handle does not refer to loaded image */
+               ret = EFI_INVALID_PARAMETER;
+               goto out;
+       }
+       /* A started image can only be unloaded it is the last one started. */
+       if (image_handle != current_image) {
+               ret = EFI_INVALID_PARAMETER;
                goto out;
+       }
+
+       /* Exit data is only foreseen in case of failure. */
+       if (exit_status != EFI_SUCCESS) {
+               ret = efi_update_exit_data(image_obj, exit_data_size,
+                                          exit_data);
+               /* Exiting has priority. Don't return error to caller. */
+               if (ret != EFI_SUCCESS)
+                       EFI_PRINT("%s: out of memory\n", __func__);
+       }
+       if (image_obj->image_type == IMAGE_SUBSYSTEM_EFI_APPLICATION ||
+           exit_status != EFI_SUCCESS)
+               efi_delete_image(image_obj, loaded_image_protocol);
 
        /* Make sure entry/exit counts for EFI world cross-overs match */
        EFI_EXIT(exit_status);
@@ -2749,7 +2965,7 @@ static efi_status_t EFIAPI efi_exit(efi_handle_t image_handle,
 
        panic("EFI application exited");
 out:
-       return EFI_EXIT(EFI_INVALID_PARAMETER);
+       return EFI_EXIT(ret);
 }
 
 /**