efi: Fix gcc9 error -Waddress-of-packed-member

The address of fp->path_name could be unaligned since seeking into the
device path buffer for a given node could end in byte boundary.

The fix is allocating aligned buffer by grub_malloc for holding the
UTF16 string copied from fp->path_name, and after using that buffer as
argument for grub_utf16_to_utf8 to convert it to UTF8 string.

[  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>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This commit is contained in:
Michael Chang 2019-04-11 17:14:09 +08:00 committed by Daniel Kiper
parent 4868e17507
commit 4dd4ceec02

View file

@ -372,6 +372,7 @@ 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++ = '/';
@ -382,7 +383,16 @@ 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);
@ -812,9 +822,20 @@ 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);