Re: [PATCH bpf-next 02/11] samples: bpf: makefile: fix cookie_uid_helper_example obj build

[Yonghong Song]

On 9/10/19 11:38 AM, Ivan Khoronzhuk wrote:
> Don't list userspace "cookie_uid_helper_example" object in list for
> bpf objects.
> 
> per_socket_stats_example-opjs is used to list additional dependencies

s/opjs/objs

> for user space binary from hostprogs-y list. Kbuild system creates
> rules for objects listed this way anyway and no need to worry about
> this. Despite on it, the samples bpf uses logic that hostporgs-y are
> build for userspace with includes needed for this, but "always"
> target, if it's not in hostprog-y list, uses CLANG-bpf rule and is
> intended to create bpf obj but not arch obj and uses only kernel
> includes for that. So correct it, as it breaks cross-compiling at
> least.

The above description is a little tricky to understand.
Maybe something like:
    'always' target is for bpf programs.
    'cookie_uid_helper_example.o' is a user space ELF file, and
    covered by rule `per_socket_stats_example`.
    Let us remove `always += cookie_uid_helper_example.o`,
    which avoids breaking cross compilation due to
    mismatched includes.

> 
> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx>
> ---
>   samples/bpf/Makefile | 1 -
>   1 file changed, 1 deletion(-)
> 
> diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
> index f50ca852c2a8..43dee90dffa4 100644
> --- a/samples/bpf/Makefile
> +++ b/samples/bpf/Makefile
> @@ -145,7 +145,6 @@ always += sampleip_kern.o
>   always += lwt_len_hist_kern.o
>   always += xdp_tx_iptunnel_kern.o
>   always += test_map_in_map_kern.o
> -always += cookie_uid_helper_example.o
>   always += tcp_synrto_kern.o
>   always += tcp_rwnd_kern.o
>   always += tcp_bufs_kern.o
>