efi_loader: multi part device paths to text

Our current implementation of
EFI_DEVICE_PATH_TO_TEXT_PROTOCOL.ConvertDevicePathToText() truncates multi
part device paths after the first part. We should convert all parts.

Render device path instance ends as commas. This is not explicitly
described in the UEFI spec but mimics what EDK II does.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

diff --git a/lib/efi_loader/efi_device_path_to_text.c b/lib/efi_loader/efi_device_path_to_text.c
index 1aaa9f94fa4547fe2307e085145aea5613c7e6d3..81b8ac23ba5e1add9fd6e28a78ba101f402d9de2 100644 (file)
--- a/lib/efi_loader/efi_device_path_to_text.c
+++ b/lib/efi_loader/efi_device_path_to_text.c
@@ -369,11 +369,18 @@ static uint16_t EFIAPI *efi_convert_device_path_to_text(
 
        if (!device_path)
                goto out;
-       while (device_path &&
-              str + MAX_NODE_LEN < buffer + MAX_PATH_LEN) {
-               *str++ = '/';
-               str = efi_convert_single_device_node_to_text(str, device_path);
-               device_path = efi_dp_next(device_path);
+       while (device_path && str + MAX_NODE_LEN < buffer + MAX_PATH_LEN) {
+               if (device_path->type == DEVICE_PATH_TYPE_END) {
+                       if (device_path->sub_type !=
+                           DEVICE_PATH_SUB_TYPE_INSTANCE_END)
+                               break;
+                       *str++ = ',';
+               } else {
+                       *str++ = '/';
+                       str = efi_convert_single_device_node_to_text(
+                                                       str, device_path);
+               }
+               *(u8 **)&device_path += device_path->length;
        }
 
        text = efi_str_to_u16(buffer);