From 1e5271393d777f6159d896943b4c44c4f3ecff52 Mon Sep 17 00:00:00 2001 From: Thomas Weißschuh Date: Thu, 15 Jan 2026 08:35:44 +0100 Subject: hyper-v: Mark inner union in hv_kvp_exchg_msg_value as packed MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The unpacked union within a packed struct generates alignment warnings on clang for 32-bit ARM: ./usr/include/linux/hyperv.h:361:2: error: field within 'struct hv_kvp_exchg_msg_value' is less aligned than 'union hv_kvp_exchg_msg_value::(anonymous at ./usr/include/linux/hyperv.h:361:2)' and is usually due to 'struct hv_kvp_exchg_msg_value' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access] 361 | union { | ^ With the recent changes to compile-test the UAPI headers in more cases, this warning in combination with CONFIG_WERROR breaks the build. Fix the warning. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202512140314.DzDxpIVn-lkp@intel.com/ Reported-by: Nathan Chancellor Closes: https://lore.kernel.org/linux-kbuild/20260110-uapi-test-disable-headers-arm-clang-unaligned-access-v1-1-b7b0fa541daa@kernel.org/ Suggested-by: Arnd Bergmann Link: https://lore.kernel.org/linux-kbuild/29b2e736-d462-45b7-a0a9-85f8d8a3de56@app.fastmail.com/ Signed-off-by: Thomas Weißschuh Acked-by: Wei Liu (Microsoft) Tested-by: Nicolas Schier Reviewed-by: Nicolas Schier Acked-by: Greg Kroah-Hartman Link: https://patch.msgid.link/20260115-kbuild-alignment-vbox-v1-1-076aed1623ff@linutronix.de Signed-off-by: Nathan Chancellor --- include/uapi/linux/hyperv.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/uapi') diff --git a/include/uapi/linux/hyperv.h b/include/uapi/linux/hyperv.h index aaa502a7bff4..1749b35ab2c2 100644 --- a/include/uapi/linux/hyperv.h +++ b/include/uapi/linux/hyperv.h @@ -362,7 +362,7 @@ struct hv_kvp_exchg_msg_value { __u8 value[HV_KVP_EXCHANGE_MAX_VALUE_SIZE]; __u32 value_u32; __u64 value_u64; - }; + } __attribute__((packed)); } __attribute__((packed)); struct hv_kvp_msg_enumerate { -- cgit v1.2.3 From c25d01e1c4f2d43f47af87c00e223f5ca7c71792 Mon Sep 17 00:00:00 2001 From: Thomas Weißschuh Date: Thu, 15 Jan 2026 08:35:45 +0100 Subject: virt: vbox: uapi: Mark inner unions in packed structs as packed MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Closes: https://lore.kernel.org/oe-kbuild-all/202512140314.DzDxpIVn-lkp@intel.com/ Reported-by: Nathan Chancellor Closes: https://lore.kernel.org/linux-kbuild/20260110-uapi-test-disable-headers-arm-clang-unaligned-access-v1-1-b7b0fa541daa@kernel.org/ Suggested-by: Arnd Bergmann Link: https://lore.kernel.org/linux-kbuild/29b2e736-d462-45b7-a0a9-85f8d8a3de56@app.fastmail.com/ Signed-off-by: Thomas Weißschuh Tested-by: Nicolas Schier Reviewed-by: Nicolas Schier Acked-by: Greg Kroah-Hartman Link: https://patch.msgid.link/20260115-kbuild-alignment-vbox-v1-2-076aed1623ff@linutronix.de Signed-off-by: Nathan Chancellor --- include/uapi/linux/vbox_vmmdev_types.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/uapi') 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. */ -- cgit v1.2.3