On 2020-03-12 at 13:48:21 +0100, Quentin Monnet <quentin@xxxxxxxxxxxxx> wrote:
> 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?
Good point. It seems I actually didn't test this properly. Will change
the typedefs to use the existing __bitwise__.
> Makefile change works well otherwise, thanks (tested on Ubuntu with and
> without gcc-multilib).
Thanks for testing.
- Tobias
