[PATCH 8/8] efi: fix gcc9 error address-of-packed-member

[Michael Chang <mchang@suse.com>]

Copy the packed member to the buffer returned by grub_malloc, which is
supposed to be suitably aligned for any data type, then use it as
argument to grub_utf16_to_utf8.

The solved gcc9 error like this.

[  255s] ../../grub-core/kern/efi/efi.c: In function 'grub_efi_get_filename':
[  255s] ../../grub-core/kern/efi/efi.c:410:60: error: taking address of packed member of 'struct grub_efi_file_path_device_path' may result in an unaligned pointer value [-Werror=address-of-packed-member]
[  255s]   410 |    p = (char *) grub_utf16_to_utf8 ((unsigned char *) p, fp->path_name, len);
[  255s]       |                                                          ~~^~~~~~~~~~~
[  255s] ../../grub-core/kern/efi/efi.c: In function 'grub_efi_print_device_path':
[  255s] ../../grub-core/kern/efi/efi.c:900:33: error: taking address of packed member of 'struct grub_efi_file_path_device_path' may result in an unaligned pointer value [-Werror=address-of-packed-member]
[  255s]   900 |     *grub_utf16_to_utf8 (buf, fp->path_name,
[  255s]       |                               ~~^~~~~~~~~~~

Signed-off-by: Michael Chang <mchang@suse.com>
---
 grub-core/kern/efi/efi.c | 27 ++++++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

diff --git a/grub-core/kern/efi/efi.c b/grub-core/kern/efi/efi.c
index 708581fcb..62cd9829e 100644
--- a/grub-core/kern/efi/efi.c
+++ b/grub-core/kern/efi/efi.c
@@ -369,6 +369,7 @@ grub_efi_get_filename (grub_efi_device_path_t *dp0)
 	{
 	  grub_efi_file_path_device_path_t *fp;
 	  grub_efi_uint16_t len;
+	  grub_efi_char16_t *dup_name;
 
 	  *p++ = '/';
 
@@ -379,7 +380,16 @@ grub_efi_get_filename (grub_efi_device_path_t *dp0)
 	  while (len > 0 && fp->path_name[len - 1] == 0)
 	    len--;
 
-	  p = (char *) grub_utf16_to_utf8 ((unsigned char *) p, fp->path_name, len);
+	  dup_name = grub_malloc (len * sizeof (*dup_name));
+	  if (!dup_name)
+	    {
+	      grub_free (name);
+	      return NULL;
+	    }
+	  p = (char *) grub_utf16_to_utf8 ((unsigned char *) p,
+					    grub_memcpy (dup_name, fp->path_name, len * sizeof (*dup_name)),
+					    len);
+	  grub_free (dup_name);
 	}
 
       dp = GRUB_EFI_NEXT_DEVICE_PATH (dp);
@@ -809,9 +819,20 @@ grub_efi_print_device_path (grub_efi_device_path_t *dp)
 		fp = (grub_efi_file_path_device_path_t *) dp;
 		buf = grub_malloc ((len - 4) * 2 + 1);
 		if (buf)
-		  *grub_utf16_to_utf8 (buf, fp->path_name,
+		  {
+		    grub_efi_char16_t *dup_name = grub_malloc (len - 4);
+		    if (!dup_name)
+		      {
+			grub_errno = GRUB_ERR_NONE;
+			grub_printf ("/File((null))");
+			grub_free (buf);
+			break;
+		      }
+		    *grub_utf16_to_utf8 (buf, grub_memcpy (dup_name, fp->path_name, len - 4),
 				       (len - 4) / sizeof (grub_efi_char16_t))
-		    = '\0';
+		      = '\0';
+		    grub_free (dup_name);
+		  }
 		else
 		  grub_errno = GRUB_ERR_NONE;
 		grub_printf ("/File(%s)", buf);
-- 
2.16.4