| Message ID | 20240124001026.2627-1-pavan.kumar.linga@intel.com (mailing list archive) |
|---|---|
| State | Awaiting Upstream |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [iwl-net,v4] idpf: avoid compiler padding in virtchnl2_ptype struct | expand |
diff --git a/drivers/net/ethernet/intel/idpf/virtchnl2.h b/drivers/net/ethernet/intel/idpf/virtchnl2.h index 8dc83788972..506036e7df0 100644 --- a/drivers/net/ethernet/intel/idpf/virtchnl2.h +++ b/drivers/net/ethernet/intel/idpf/virtchnl2.h @@ -23,7 +23,7 @@ * is not exactly the correct length. */ #define VIRTCHNL2_CHECK_STRUCT_LEN(n, X) \ - static_assert((n) == sizeof(struct X)) + static_assert(sizeof(struct X) == (n)) /* New major set of opcodes introduced and so leaving room for * old misc opcodes to be added in future. Also these opcodes may only @@ -978,7 +978,7 @@ struct virtchnl2_ptype { u8 proto_id_count; __le16 pad; __le16 proto_id[]; -}; +} __packed __aligned(2); VIRTCHNL2_CHECK_STRUCT_LEN(6, virtchnl2_ptype); /**
In the arm random config file, kconfig option 'CONFIG_AEABI' is disabled which results in adding the compiler flag '-mabi=apcs-gnu'. This causes the compiler to add padding in virtchnl2_ptype structure to align it to 8 bytes, resulting in the following size check failure: include/linux/build_bug.h:78:41: error: static assertion failed: "(6) == sizeof(struct virtchnl2_ptype)" 78 | #define __static_assert(expr, msg, ...) _Static_assert(expr, msg) | ^~~~~~~~~~~~~~ include/linux/build_bug.h:77:34: note: in expansion of macro '__static_assert' 77 | #define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr) | ^~~~~~~~~~~~~~~ drivers/net/ethernet/intel/idpf/virtchnl2.h:26:9: note: in expansion of macro 'static_assert' 26 | static_assert((n) == sizeof(struct X)) | ^~~~~~~~~~~~~ drivers/net/ethernet/intel/idpf/virtchnl2.h:982:1: note: in expansion of macro 'VIRTCHNL2_CHECK_STRUCT_LEN' 982 | VIRTCHNL2_CHECK_STRUCT_LEN(6, virtchnl2_ptype); | ^~~~~~~~~~~~~~~~~~~~~~~~~~ Avoid the compiler padding by using "__packed" structure attribute for the virtchnl2_ptype struct. Also align the structure by using "__aligned(2)" for better code optimization. While at it, swap the static_assert conditional statement variables. Fixes: 0d7502a9b4a7 ("virtchnl: add virtchnl version 2 ops") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202312220250.ufEm8doQ-lkp@intel.com Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com> Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga@intel.com> --- v4: - swap the static_assert conditional statement variables v3: - add "__aligned(2)" structure attribute for better code optimization v2: - add the kconfig option causing the compile failure to the commit message --- drivers/net/ethernet/intel/idpf/virtchnl2.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)