2020-03-12 11:53 UTC+0100 ~ Tobias Klauser <tklauser@xxxxxxxxxx>
> When compiling bpftool on a system where the /usr/include/asm symlink
> doesn't exist (e.g. on an Ubuntu system without gcc-multilib installed),
> the build fails with:
>
> CLANG skeleton/profiler.bpf.o
> In file included from skeleton/profiler.bpf.c:4:
> In file included from /usr/include/linux/bpf.h:11:
> /usr/include/linux/types.h:5:10: fatal error: 'asm/types.h' file not found
> #include <asm/types.h>
> ^~~~~~~~~~~~~
> 1 error generated.
> make: *** [Makefile:123: skeleton/profiler.bpf.o] Error 1
>
> This indicates that the build is using linux/types.h from system headers
> instead of source tree headers.
>
> To fix this, adjust the clang search path to include the necessary
> headers from tools/testing/selftests/bpf/include/uapi and
> tools/include/uapi. Also undef __bitwise in skeleton/profiler.h avoid
> clashing with the empty definition in
> tools/testing/selftests/bpf/include/uapi/linux/types.h.
>
> Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
> Cc: Song Liu <songliubraving@xxxxxx>
> Cc: Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx>
> Signed-off-by: Tobias Klauser <tklauser@xxxxxxxxxx>
> diff --git a/tools/bpf/bpftool/skeleton/profiler.h b/tools/bpf/bpftool/skeleton/profiler.h
> index e03b53eae767..95358c0df5ef 100644
> --- a/tools/bpf/bpftool/skeleton/profiler.h
> +++ b/tools/bpf/bpftool/skeleton/profiler.h
> @@ -27,6 +27,7 @@ enum {
> true = 1,
> };
>
> +#undef __bitwise
> #ifdef __CHECKER__
> #define __bitwise__ __attribute__((bitwise))
> #else
>
Even with the #undef above, I get warnings on __bitwise being redefined
in tools/testing/selftests/bpf/include/uapi/linux/types.h. Can we maybe
just find another name (or number of underscores) for the macro in
skeleton/profiler.h?
Makefile change works well otherwise, thanks (tested on Ubuntu with and
without gcc-multilib).
Quentin
