The unpacked unions within a packed struct generates alignment warnings
on clang for 32-bit ARM:
./usr/include/linux/vbox_vmmdev_types.h:239:4: error: field u within 'struct
vmmdev_hgcm_function_parameter32'
is less aligned than 'union (unnamed union at
./usr/include/linux/vbox_vmmdev_types.h:223:2)'
and is usually due to 'struct vmmdev_hgcm_function_parameter32' being packed,
which can lead to unaligned accesses [-Werror,-Wunaligned-access]
239 | } u;
| ^
./usr/include/linux/vbox_vmmdev_types.h:254:6: error: field u within
'struct vmmdev_hgcm_function_parameter64::(anonymous union)::(unnamed at
./usr/include/linux/vbox_vmmdev_types.h:249:3)'
is less aligned than 'union (unnamed union at
./usr/include/linux/vbox_vmmdev_types.h:251:4)' and is usually due to
'struct vmmdev_hgcm_function_parameter64::(anonymous union)::(unnamed at
./usr/include/linux/vbox_vmmdev_types.h:249:3)'
being packed, which can lead to unaligned accesses
[-Werror,-Wunaligned-access]
With the recent changes to compile-test the UAPI headers in more cases,
these warning in combination with CONFIG_WERROR breaks the build.
Fix the warnings.
Reported-by: kernel test robot <[email protected]>
Closes:
https://lore.kernel.org/oe-kbuild-all/[email protected]/
Reported-by: Nathan Chancellor <[email protected]>
Closes:
https://lore.kernel.org/linux-kbuild/20260110-uapi-test-disable-headers-arm-clang-unaligned-access-v1-1-b7b0fa541...@kernel.org/
Suggested-by: Arnd Bergmann <[email protected]>
Link:
https://lore.kernel.org/linux-kbuild/[email protected]/
Signed-off-by: Thomas Weißschuh <[email protected]>
---
include/uapi/linux/vbox_vmmdev_types.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/uapi/linux/vbox_vmmdev_types.h
b/include/uapi/linux/vbox_vmmdev_types.h
index 6073858d52a2..11f3627c3729 100644
--- a/include/uapi/linux/vbox_vmmdev_types.h
+++ b/include/uapi/linux/vbox_vmmdev_types.h
@@ -236,7 +236,7 @@ struct vmmdev_hgcm_function_parameter32 {
/** Relative to the request header. */
__u32 offset;
} page_list;
- } u;
+ } __packed u;
} __packed;
VMMDEV_ASSERT_SIZE(vmmdev_hgcm_function_parameter32, 4 + 8);
@@ -251,7 +251,7 @@ struct vmmdev_hgcm_function_parameter64 {
union {
__u64 phys_addr;
__u64 linear_addr;
- } u;
+ } __packed u;
} __packed pointer;
struct {
/** Size of the buffer described by the page list. */
--
2.52.0
