efi_loader: fix GetInfo and SetInfo

* Some of our file system drivers cannot report a file size for
  directories. Use a dummy value in this case.
* For SetInfo the UEFI spec requires to ignore the file size field.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/lib/efi_loader/efi_file.c b/lib/efi_loader/efi_file.c
index c92d8ccf0040bcfdbe29b20d493a001c572d74f0..95b3c890ee96d39f5bb1061e4e14beb6727a29ef 100644 (file)
--- a/lib/efi_loader/efi_file.c
+++ b/lib/efi_loader/efi_file.c
@@ -864,8 +864,16 @@ static efi_status_t EFIAPI efi_file_getinfo(struct efi_file_handle *file,
                }
 
                ret = efi_get_file_size(fh, &file_size);
-               if (ret != EFI_SUCCESS)
-                       goto error;
+               if (ret != EFI_SUCCESS) {
+                       if (!fh->isdir)
+                               goto error;
+                       /*
+                        * Some file drivers don't implement fs_size() for
+                        * directories. Use a dummy non-zero value.
+                        */
+                       file_size = 4096;
+                       ret = EFI_SUCCESS;
+               }
 
                memset(info, 0, required_size);
 
@@ -976,14 +984,16 @@ static efi_status_t EFIAPI efi_file_setinfo(struct efi_file_handle *file,
                }
                free(new_file_name);
                /* Check for truncation */
-               ret = efi_get_file_size(fh, &file_size);
-               if (ret != EFI_SUCCESS)
-                       goto out;
-               if (file_size != info->file_size) {
-                       /* TODO: we do not support truncation */
-                       EFI_PRINT("Truncation not supported\n");
-                       ret = EFI_ACCESS_DENIED;
-                       goto out;
+               if (!fh->isdir) {
+                       ret = efi_get_file_size(fh, &file_size);
+                       if (ret != EFI_SUCCESS)
+                               goto out;
+                       if (file_size != info->file_size) {
+                               /* TODO: we do not support truncation */
+                               EFI_PRINT("Truncation not supported\n");
+                               ret = EFI_ACCESS_DENIED;
+                               goto out;
+                       }
                }
                /*
                 * We do not care for the other attributes