On Wed, 2024-01-31 at 10:44 +0100, Jose E. Marchesi wrote:
> [Differences from V1:
> - Now pragmas are used in testfiles instead of flags
> in Makefile.]
>
> GCC implements the -Wno-address-of-packed-member warning, which is
> enabled by -Wall, that warns about taking the address of a packed
> struct field when it can lead to an "unaligned" address. Clang
> doesn't support this warning.
>
> This triggers the following errors (-Werror) when building three
> particular BPF selftests with GCC:
>
> progs/test_cls_redirect.c
> 986 | if (ipv4_is_fragment((void *)&encap->ip)) {
> progs/test_cls_redirect_dynptr.c
> 410 | pkt_ipv4_checksum((void *)&encap_gre->ip);
> progs/test_cls_redirect.c
> 521 | pkt_ipv4_checksum((void *)&encap_gre->ip);
> progs/test_tc_tunnel.c
> 232 | set_ipv4_csum((void *)&h_outer.ip);
>
> These warnings do not signal any real problem in the tests as far as I
> can see.
>
> This patch adds pragmas to these test files that inhibit the
> -Waddress-of-packed-member if the compiler is not Clang.
>
> Tested in bpf-next master.
> No regressions.
>
> Signed-off-by: Jose E. Marchesi <jose.marchesi@xxxxxxxxxx>
> Cc: Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx>
> Cc: Yonghong Song <yhs@xxxxxxxx>
> Cc: Eduard Zingerman <eddyz87@xxxxxxxxx>
> Cc: David Faust <david.faust@xxxxxxxxxx>
> Cc: Cupertino Miranda <cupertino.miranda@xxxxxxxxxx>
> ---
Acked-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
[...]
