efi_loader: delete handle from events when a protocol is uninstalled
When a notification event is registered for a protocol the handle of the
protocol is added in our event notification list. When all the protocols
of the handle are uninstalled we delete the handle but we do not remove
it from the event notification list.
Clean up the protocol removal functions and add a wrapper which
- Removes the to-be deleted handle from any lists it participates
- Remove the handle if no more protocols are present
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 0e89c85..0b7579c 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -61,7 +61,7 @@
static efi_status_t efi_uninstall_protocol
(efi_handle_t handle, const efi_guid_t *protocol,
- void *protocol_interface);
+ void *protocol_interface, bool preserve);
/* 1 if inside U-Boot code, 0 if inside EFI payload code */
static int entry_count = 1;
@@ -208,6 +208,36 @@
}
/**
+ * efi_purge_handle() - Clean the deleted handle from the various lists
+ * @handle: handle to remove
+ *
+ * Return: status code
+ */
+static efi_status_t efi_purge_handle(efi_handle_t handle)
+{
+ struct efi_register_notify_event *item;
+
+ if (!list_empty(&handle->protocols))
+ return EFI_ACCESS_DENIED;
+ /* The handle is about to be freed. Remove it from events */
+ list_for_each_entry(item, &efi_register_notify_events, link) {
+ struct efi_protocol_notification *hitem, *hnext;
+
+ list_for_each_entry_safe(hitem, hnext, &item->handles, link) {
+ if (handle == hitem->handle) {
+ list_del(&hitem->link);
+ free(hitem);
+ }
+ }
+ }
+ /* The last protocol has been removed, delete the handle. */
+ list_del(&handle->link);
+ free(handle);
+
+ return EFI_SUCCESS;
+}
+
+/**
* efi_process_event_queue() - process event queue
*/
static void efi_process_event_queue(void)
@@ -615,7 +645,7 @@
efi_status_t ret;
ret = efi_uninstall_protocol(handle, &protocol->guid,
- protocol->protocol_interface);
+ protocol->protocol_interface, true);
if (ret != EFI_SUCCESS)
return ret;
}
@@ -639,10 +669,7 @@
return ret;
}
- list_del(&handle->link);
- free(handle);
-
- return ret;
+ return efi_purge_handle(handle);
}
/**
@@ -1356,6 +1383,8 @@
* @handle: handle from which the protocol shall be removed
* @protocol: GUID of the protocol to be removed
* @protocol_interface: interface to be removed
+ * @preserve: preserve or delete the handle and remove it from any
+ * list it participates if no protocols remain
*
* This function DOES NOT delete a handle without installed protocol.
*
@@ -1363,7 +1392,7 @@
*/
static efi_status_t efi_uninstall_protocol
(efi_handle_t handle, const efi_guid_t *protocol,
- void *protocol_interface)
+ void *protocol_interface, bool preserve)
{
struct efi_handler *handler;
struct efi_open_protocol_info_item *item;
@@ -1397,6 +1426,14 @@
goto out;
}
r = efi_remove_protocol(handle, protocol, protocol_interface);
+ if (r != EFI_SUCCESS)
+ return r;
+ /*
+ * We don't care about the return value here since the
+ * handle might have more protocols installed
+ */
+ if (!preserve)
+ efi_purge_handle(handle);
out:
return r;
}
@@ -1422,15 +1459,10 @@
EFI_ENTRY("%p, %pUs, %p", handle, protocol, protocol_interface);
- ret = efi_uninstall_protocol(handle, protocol, protocol_interface);
+ ret = efi_uninstall_protocol(handle, protocol, protocol_interface, false);
if (ret != EFI_SUCCESS)
goto out;
- /* If the last protocol has been removed, delete the handle. */
- if (list_empty(&handle->protocols)) {
- list_del(&handle->link);
- free(handle);
- }
out:
return EFI_EXIT(ret);
}
@@ -2785,7 +2817,7 @@
efi_uninstall_multiple_protocol_interfaces_int(efi_handle_t handle,
efi_va_list argptr)
{
- const efi_guid_t *protocol;
+ const efi_guid_t *protocol, *next_protocol;
void *protocol_interface;
efi_status_t ret = EFI_SUCCESS;
size_t i = 0;
@@ -2795,25 +2827,34 @@
return EFI_INVALID_PARAMETER;
efi_va_copy(argptr_copy, argptr);
+ protocol = efi_va_arg(argptr, efi_guid_t*);
for (;;) {
- protocol = efi_va_arg(argptr, efi_guid_t*);
+ /*
+ * If efi_uninstall_protocol() fails we need to be able to
+ * reinstall the previously uninstalled protocols on the same
+ * handle.
+ * Instead of calling efi_uninstall_protocol(...,..., false)
+ * and potentially removing the handle, only allow the handle
+ * removal on the last protocol that we requested to uninstall.
+ * That way we can preserve the handle in case the latter fails
+ */
+ bool preserve = true;
+
if (!protocol)
break;
protocol_interface = efi_va_arg(argptr, void*);
+ next_protocol = efi_va_arg(argptr, efi_guid_t*);
+ if (!next_protocol)
+ preserve = false;
ret = efi_uninstall_protocol(handle, protocol,
- protocol_interface);
+ protocol_interface, preserve);
if (ret != EFI_SUCCESS)
break;
i++;
+ protocol = next_protocol;
}
- if (ret == EFI_SUCCESS) {
- /* If the last protocol has been removed, delete the handle. */
- if (list_empty(&handle->protocols)) {
- list_del(&handle->link);
- free(handle);
- }
+ if (ret == EFI_SUCCESS)
goto out;
- }
/* If an error occurred undo all changes. */
for (; i; --i) {
@@ -3712,7 +3753,7 @@
new_interface);
/* Uninstall protocol but do not delete handle */
- ret = efi_uninstall_protocol(handle, protocol, old_interface);
+ ret = efi_uninstall_protocol(handle, protocol, old_interface, true);
if (ret != EFI_SUCCESS)
goto out;