| Message ID | 20240109013229.773552-1-pavan.kumar.linga@intel.com |
|---|---|
| State | Accepted |
| Delegated to: | Anthony Nguyen |
| Headers | show |
| Series | [iwl-net,v3] idpf: avoid compiler padding in virtchnl2_ptype struct | expand |
> -----Original Message----- > From: Pavan Kumar Linga <pavan.kumar.linga@intel.com> > Sent: Monday, January 8, 2024 5:32 PM > To: intel-wired-lan@lists.osuosl.org > Cc: netdev@vger.kernel.org; Kitszel, Przemyslaw > <przemyslaw.kitszel@intel.com>; pmenzel@molgen.mpg.de; Tantilov, Emil S > <emil.s.tantilov@intel.com>; horms@kernel.org; Linga, Pavan Kumar > <pavan.kumar.linga@intel.com>; lkp <lkp@intel.com> > Subject: [PATCH iwl-net v3] idpf: avoid compiler padding in virtchnl2_ptype > struct > > 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. > > 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> > > --- > 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 | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/intel/idpf/virtchnl2.h > b/drivers/net/ethernet/intel/idpf/virtchnl2.h > index 8dc83788972..4a3c4454d25 100644 > --- a/drivers/net/ethernet/intel/idpf/virtchnl2.h > +++ b/drivers/net/ethernet/intel/idpf/virtchnl2.h Tested-by: Krishneil Singh <krishneil.k.singh@intel.com>
diff --git a/drivers/net/ethernet/intel/idpf/virtchnl2.h b/drivers/net/ethernet/intel/idpf/virtchnl2.h index 8dc83788972..4a3c4454d25 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 __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. 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> --- 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 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)