[PATCH 1/8] cpio: fix gcc9 error address-of-packed-member

[Michael Chang <mchang@suse.com>]

Change the read_number function to use void* type as its first argument
to silence the warning. The pointer is later type casted to
grub_uint16_t* and use grub_get_unaligned16 for safely deferencing it
for the value.

The solved gcc9 error like this.

[   59s] In file included from ../grub-core/fs/cpio.c:51:
[   59s] ../grub-core/fs/cpio_common.c: In function 'grub_cpio_find_file':
[   59s] ../grub-core/fs/cpio_common.c:58:31: error: taking address of packed member of 'struct head' may result in an unaligned pointer value [-Werror=address-of-packed-member]
[   59s]    58 |   data->size = read_number (hd.filesize, ARRAY_SIZE (hd.filesize));
[   59s]       |                             ~~^~~~~~~~~
[   59s] ../grub-core/fs/cpio_common.c:60:29: error: taking address of packed member of 'struct head' may result in an unaligned pointer value [-Werror=address-of-packed-member]
[   59s]    60 |     *mtime = read_number (hd.mtime, ARRAY_SIZE (hd.mtime));
[   59s]       |                           ~~^~~~~~
[   59s] ../grub-core/fs/cpio_common.c:61:28: error: taking address of packed member of 'struct head' may result in an unaligned pointer value [-Werror=address-of-packed-member]
[   59s]    61 |   modeval = read_number (hd.mode, ARRAY_SIZE (hd.mode));
[   59s]       |                          ~~^~~~~
[   59s] ../grub-core/fs/cpio_common.c:62:29: error: taking address of packed member of 'struct head' may result in an unaligned pointer value [-Werror=address-of-packed-member]
[   59s]    62 |   namesize = read_number (hd.namesize, ARRAY_SIZE (hd.namesize));
[   59s]       |                           ~~^~~~~~~~~
[   59s] In file included from ../grub-core/fs/cpio_be.c:51:
[   59s] ../grub-core/fs/cpio_common.c: In function 'grub_cpio_find_file':
[   59s] ../grub-core/fs/cpio_common.c:58:31: error: taking address of packed member of 'struct head' may result in an unaligned pointer value [-Werror=address-of-packed-member]
[   59s]    58 |   data->size = read_number (hd.filesize, ARRAY_SIZE (hd.filesize));
[   59s]       |                             ~~^~~~~~~~~
[   59s] ../grub-core/fs/cpio_common.c:60:29: error: taking address of packed member of 'struct head' may result in an unaligned pointer value [-Werror=address-of-packed-member]
[   59s]    60 |     *mtime = read_number (hd.mtime, ARRAY_SIZE (hd.mtime));
[   59s]       |                           ~~^~~~~~
[   59s] ../grub-core/fs/cpio_common.c:61:28: error: taking address of packed member of 'struct head' may result in an unaligned pointer value [-Werror=address-of-packed-member]
[   59s]    61 |   modeval = read_number (hd.mode, ARRAY_SIZE (hd.mode));
[   59s]       |                          ~~^~~~~
[   59s] ../grub-core/fs/cpio_common.c:62:29: error: taking address of packed member of 'struct head' may result in an unaligned pointer value [-Werror=address-of-packed-member]
[   59s]    62 |   namesize = read_number (hd.namesize, ARRAY_SIZE (hd.namesize));
[   59s]       |                           ~~^~~~~~~~~

Signed-off-by: Michael Chang <mchang@suse.com>
---
 grub-core/fs/cpio.c    | 5 +++--
 grub-core/fs/cpio_be.c | 5 +++--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/grub-core/fs/cpio.c b/grub-core/fs/cpio.c
index dab5f9898..a1aa66689 100644
--- a/grub-core/fs/cpio.c
+++ b/grub-core/fs/cpio.c
@@ -38,11 +38,12 @@ struct head
 } GRUB_PACKED;
 
 static inline unsigned long long
-read_number (const grub_uint16_t *arr, grub_size_t size)
+read_number (const void *arr, grub_size_t size)
 {
   long long ret = 0;
+  const grub_uint16_t *p = (const grub_uint16_t *)arr;
   while (size--)
-    ret = (ret << 16) | grub_le_to_cpu16 (*arr++);
+    ret = (ret << 16) | grub_le_to_cpu16 (grub_get_unaligned16 (p++));
   return ret;
 }
 
diff --git a/grub-core/fs/cpio_be.c b/grub-core/fs/cpio_be.c
index 846548892..9460d0ec1 100644
--- a/grub-core/fs/cpio_be.c
+++ b/grub-core/fs/cpio_be.c
@@ -38,11 +38,12 @@ struct head
 } GRUB_PACKED;
 
 static inline unsigned long long
-read_number (const grub_uint16_t *arr, grub_size_t size)
+read_number (const void *arr, grub_size_t size)
 {
   long long ret = 0;
+  const grub_uint16_t *p = (const grub_uint16_t *)arr;
   while (size--)
-    ret = (ret << 16) | grub_be_to_cpu16 (*arr++);
+    ret = (ret << 16) | grub_be_to_cpu16 (grub_get_unaligned16 (p++));
   return ret;
 }
 
-- 
2.16.4