efi_loader: DisconnectController() with no driver

If DisconnectController() is called and no driver is managing
ControllerHandle, return EFI_SUCCESS.

UEFI SCT II 2017, 3.3.12 DisconnectController(), 5.1.3.12.4 - 5.1.3.12.6

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 54fff85..027bd6d 100644 (file)
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -1134,11 +1134,15 @@ static efi_status_t efi_get_drivers(efi_handle_t handle,
                                ++count;
                }
        }
+       *number_of_drivers = 0;
+       if (!count) {
+               *driver_handle_buffer = NULL;
+               return EFI_SUCCESS;
+       }
        /*
         * Create buffer. In case of duplicate driver assignments the buffer
         * will be too large. But that does not harm.
         */
-       *number_of_drivers = 0;
        *driver_handle_buffer = calloc(count, sizeof(efi_handle_t));
        if (!*driver_handle_buffer)
                return EFI_OUT_OF_RESOURCES;
@@ -1194,7 +1198,8 @@ static efi_status_t efi_disconnect_all_drivers
                              &driver_handle_buffer);
        if (ret != EFI_SUCCESS)
                return ret;
-
+       if (!number_of_drivers)
+               return EFI_SUCCESS;
        ret = EFI_NOT_FOUND;
        while (number_of_drivers) {
                r = EFI_CALL(efi_disconnect_controller(