efi_loader: run CreateEvent() notify function based on flags

The UEFI specification states that the tpl, function and context
arguments are to be ignored if neither EVT_NOTIFY_WAIT or
EVT_NOTIFY_SIGNAL are specified.  This matches observed behaviour with
an AMI EDK2 based UEFI implementation.

Skip calling the notify function if neither flag is present.

Signed-off-by: Jonathan Gray <jsg@jsg.id.au>
Acked-By: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

include/efi_api.h

@@ -28,6 +28,9 @@ enum efi_event_type {
 	EFI_TIMER_RELATIVE = 2
 };
 
+#define EVT_NOTIFY_WAIT		0x00000100
+#define EVT_NOTIFY_SIGNAL	0x00000200
+
 /* EFI Boot Services table */
 struct efi_boot_services {
 	struct efi_table_hdr hdr;

lib/efi_loader/efi_boottime.c

@@ -210,7 +210,9 @@ void efi_timer_check(void)
 		/* Triggering! */
 		if (efi_event.trigger_type == EFI_TIMER_PERIODIC)
 			efi_event.trigger_next += efi_event.trigger_time / 10;
-		efi_event.notify_function(&efi_event, efi_event.notify_context);
+		if (efi_event.type & (EVT_NOTIFY_WAIT | EVT_NOTIFY_SIGNAL))
+			efi_event.notify_function(&efi_event,
+			                          efi_event.notify_context);
 	}
 
 	WATCHDOG_RESET();