[Intel-wired-lan] [PATCH] virtchnl: Add missing padding to virtchnl_proto_hdrs
Jesse Brandeburg
jesse.brandeburg at intel.com
Wed May 19 22:16:00 UTC 2021
Geert Uytterhoeven wrote:
> On m68k (Coldfire M547x):
>
> CC drivers/net/ethernet/intel/i40e/i40e_main.o
> In file included from drivers/net/ethernet/intel/i40e/i40e_prototype.h:9,
> from drivers/net/ethernet/intel/i40e/i40e.h:41,
> from drivers/net/ethernet/intel/i40e/i40e_main.c:12:
> include/linux/avf/virtchnl.h:153:36: warning: division by zero [-Wdiv-by-zero]
> 153 | { virtchnl_static_assert_##X = (n)/((sizeof(struct X) == (n)) ? 1 : 0) }
> | ^
> include/linux/avf/virtchnl.h:844:1: note: in expansion of macro ‘VIRTCHNL_CHECK_STRUCT_LEN’
> 844 | VIRTCHNL_CHECK_STRUCT_LEN(2312, virtchnl_proto_hdrs);
> | ^~~~~~~~~~~~~~~~~~~~~~~~~
> include/linux/avf/virtchnl.h:844:33: error: enumerator value for ‘virtchnl_static_assert_virtchnl_proto_hdrs’ is not an integer constant
> 844 | VIRTCHNL_CHECK_STRUCT_LEN(2312, virtchnl_proto_hdrs);
> | ^~~~~~~~~~~~~~~~~~~
>
> On m68k, integers are aligned on addresses that are multiples of two,
> not four, bytes. Hence the size of a structure containing integers may
> not be divisible by 4.
>
> Fix this by adding explicit padding.
Thanks Geert, I checked and x86_64 adds this padding anyway, so doesn't
result in any functional changes AFAICS. In any case, this is more
correct for a structure that is part of an API (no implicit padding!)
BTW. the patch subject is a little wrong, should have been
[PATCH net]
But I think Tony can take care of that when sending to netdev list,
unless you want to send a v2.
> Fixes: 1f7ea1cd6a374842 ("ice: Enable FDIR Configure for AVF")
> Reported-by: kernel test robot <lkp at intel.com>
> Signed-off-by: Geert Uytterhoeven <geert at linux-m68k.org>
> ---
> Compile-tested only.
Acked-by: Jesse Brandeburg <jesse.brandeburg at intel.com>
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