| Message ID | 20240105013232.44996-1-pavan.kumar.linga@intel.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [iwl-net,v2] idpf: avoid compiler padding in virtchnl2_ptype struct | expand |
On Thu, Jan 04, 2024 at 05:32:32PM -0800, Pavan Kumar Linga wrote: > 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. > > 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> > Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga@intel.com> Reviewed-by: Simon Horman <horms@kernel.org>
From: Pavan Kumar Linga <pavan.kumar.linga@intel.com> Date: Thu, 4 Jan 2024 17:32:32 -0800 > 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: [...] > diff --git a/drivers/net/ethernet/intel/idpf/virtchnl2.h b/drivers/net/ethernet/intel/idpf/virtchnl2.h > index 8dc83788972..dd750e6dcd0 100644 > --- a/drivers/net/ethernet/intel/idpf/virtchnl2.h > +++ b/drivers/net/ethernet/intel/idpf/virtchnl2.h > @@ -978,7 +978,7 @@ struct virtchnl2_ptype { > u8 proto_id_count; > __le16 pad; > __le16 proto_id[]; > -}; > +} __packed; Try using `__packed __aligned(sizeof(__le16))` (or just `__packed __aligned(2)`) here. It may generate more optimized code than just __packed, as the latter assumes the structure address in the memory can be `2n + 1`, while it fact it's aligned to 2 bytes. (another virtchnl2 design fail anyway :D) > VIRTCHNL2_CHECK_STRUCT_LEN(6, virtchnl2_ptype); > > /** Thanks, Olek
diff --git a/drivers/net/ethernet/intel/idpf/virtchnl2.h b/drivers/net/ethernet/intel/idpf/virtchnl2.h index 8dc83788972..dd750e6dcd0 100644 --- a/drivers/net/ethernet/intel/idpf/virtchnl2.h +++ b/drivers/net/ethernet/intel/idpf/virtchnl2.h @@ -978,7 +978,7 @@ struct virtchnl2_ptype { u8 proto_id_count; __le16 pad; __le16 proto_id[]; -}; +} __packed; 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. 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> Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga@intel.com> --- v2: - add the kconfig option causing the compile failure to the commit message --- drivers/net/ethernet/intel/idpf/virtchnl2.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)