1 files changed, 16 insertions, 1 deletions

diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c
index 708b777857d3..da8d29621644 100644
--- a/drivers/firmware/efi/runtime-wrappers.c
+++ b/drivers/firmware/efi/runtime-wrappers.c
@@ -202,6 +202,8 @@ void efi_call_virt_check_flags(unsigned long flags, const void *caller)
  */
 static DEFINE_SEMAPHORE(efi_runtime_lock, 1);
 
+static struct task_struct *efi_runtime_lock_owner;
+
 /*
  * Expose the EFI runtime lock to the UV platform
  */
@@ -219,6 +221,8 @@ static void __nocfi efi_call_rts(struct work_struct *work)
 	efi_status_t status = EFI_NOT_FOUND;
 	unsigned long flags;
 
+	efi_runtime_lock_owner = current;
+
 	arch_efi_call_virt_setup();
 	flags = efi_call_virt_save_flags();
 
@@ -310,6 +314,7 @@ static void __nocfi efi_call_rts(struct work_struct *work)
 
 	efi_rts_work.status = status;
 	complete(&efi_rts_work.efi_rts_comp);
+	efi_runtime_lock_owner = NULL;
 }
 
 static efi_status_t __efi_queue_work(enum efi_rts_ids id,
@@ -444,8 +449,10 @@ virt_efi_set_variable_nb(efi_char16_t *name, efi_guid_t *vendor, u32 attr,
 	if (down_trylock(&efi_runtime_lock))
 		return EFI_NOT_READY;
 
+	efi_runtime_lock_owner = current;
 	status = efi_call_virt_pointer(efi.runtime, set_variable, name, vendor,
 				       attr, data_size, data);
+	efi_runtime_lock_owner = NULL;
 	up(&efi_runtime_lock);
 	return status;
 }
@@ -481,9 +488,11 @@ virt_efi_query_variable_info_nb(u32 attr, u64 *storage_space,
 	if (down_trylock(&efi_runtime_lock))
 		return EFI_NOT_READY;
 
+	efi_runtime_lock_owner = current;
 	status = efi_call_virt_pointer(efi.runtime, query_variable_info, attr,
 				       storage_space, remaining_space,
 				       max_variable_size);
+	efi_runtime_lock_owner = NULL;
 	up(&efi_runtime_lock);
 	return status;
 }
@@ -509,12 +518,13 @@ virt_efi_reset_system(int reset_type, efi_status_t status,
 		return;
 	}
 
+	efi_runtime_lock_owner = current;
 	arch_efi_call_virt_setup();
 	efi_rts_work.efi_rts_id = EFI_RESET_SYSTEM;
 	arch_efi_call_virt(efi.runtime, reset_system, reset_type, status,
 			   data_size, data);
 	arch_efi_call_virt_teardown();
-
+	efi_runtime_lock_owner = NULL;
 	up(&efi_runtime_lock);
 }
 
@@ -587,3 +597,8 @@ efi_call_acpi_prm_handler(efi_status_t (__efiapi *handler_addr)(u64, void *),
 }
 
 #endif
+
+void efi_runtime_assert_lock_held(void)
+{
+	WARN_ON(efi_runtime_lock_owner != current);
+}