Re: [PATCH 4/4] selftests/bpf: fix compiling errors

[Du, Changbin]

On Tue, Mar 27, 2018 at 10:52:57AM +0200, Daniel Borkmann wrote:
> On 03/27/2018 05:06 AM, Du, Changbin wrote:
> > On Mon, Mar 26, 2018 at 08:02:30PM -0700, Alexei Starovoitov wrote:
> >> On Tue, Mar 27, 2018 at 10:20:10AM +0800, Du, Changbin wrote:
> >>> On Mon, Mar 26, 2018 at 07:55:13AM -0700, Alexei Starovoitov wrote:
> >>>> On Mon, Mar 26, 2018 at 05:23:28PM +0800, changbin.du@xxxxxxxxx wrote:
> >>>>> Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>
> >>>>> ---
> >>>>>  tools/testing/selftests/bpf/Makefile | 5 +++--
> >>>>>  1 file changed, 3 insertions(+), 2 deletions(-)
> >>>>>
> >>>>> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
> >>>>> index 5c43c18..dc0fdc8 100644
> >>>>> --- a/tools/testing/selftests/bpf/Makefile
> >>>>> +++ b/tools/testing/selftests/bpf/Makefile
> >>>>> @@ -10,7 +10,8 @@ ifneq ($(wildcard $(GENHDR)),)
> >>>>>    GENFLAGS := -DHAVE_GENHDR
> >>>>>  endif
> >>>>>  
> >>>>> -CFLAGS += -Wall -O2 -I$(APIDIR) -I$(LIBDIR) -I$(GENDIR) $(GENFLAGS) -I../../../include
> >>>>> +CFLAGS += -Wall -O2 -I$(APIDIR) -I$(LIBDIR) -I$(GENDIR) $(GENFLAGS) \
> >>>>> +	  -I../../../include -I../../../../usr/include
> >>>>>  LDLIBS += -lcap -lelf -lrt -lpthread
> >>>>>  
> >>>>>  # Order correspond to 'make run_tests' order
> >>>>> @@ -62,7 +63,7 @@ else
> >>>>>    CPU ?= generic
> >>>>>  endif
> >>>>>  
> >>>>> -CLANG_FLAGS = -I. -I./include/uapi -I../../../include/uapi \
> >>>>> +CLANG_FLAGS = -I. -I./include/uapi -I../../../include/uapi -I../../../../usr/include \
> >>>>>  	      -Wno-compare-distinct-pointer-types
> >>>>
> >>>> Nack.
> >>>> I suspect that will break the build for everyone else who's doing it in the directory
> >>>> itself instead of the outer one.
> >>>
> >>> This one? But I didn't see any problem.
> >>
> >> because the build was lucky and additional path ../../../../usr/include didn't point
> >> to a valid dir?
> 
> Agree.
> 
> > I am sorry but I don't understand why you mean *lucky*. Of cause, the path is valid.
> 
> The problem is that this suddenly requires users to do a 'make headers_install' in
> order to populate usr/include/ directory in the first place. While it's annoying
> enough for BPF samples where this is needed, I absolutely don't want to introduce
> this for BPF kselftests. It's the wrong approach. Besides, in tools infra, there is
> a tools/arch/*/include/uapi/asm/bitsperlong.h header copy already, so we really need
> to use that instead. Please adapt your patch accordingly and respin. Please also Cc
> us and netdev@xxxxxxxxxxxxxxx for BPF kselftests changes.
> 
> Thanks,
> Daniel
Thanks for the explanation. So we expect that tools/arch/*/include is in the searching list, right?
The corrent makefile seems not. How do you get this built?

changbin@gvt-dell-host:~/work/linux/tools/testing/selftests/bpf$ make -p
[...]
clang -I. -I./include/uapi -I../../../include/uapi -Wno-compare-distinct-pointer-types \
         -O2 -target bpf -emit-llvm -c test_pkt_access.c -o - |      \
llc -march=bpf -mcpu=generic -filetype=obj -o /home/changbin/work/linux/tools/testing/selftests/bpf/test_pkt_access.o
In file included from test_pkt_access.c:9:
In file included from ../../../include/uapi/linux/bpf.h:11:
In file included from ./include/uapi/linux/types.h:5:
/usr/include/asm-generic/int-ll64.h:11:10: fatal error: 'asm/bitsperlong.h' file not found
#include <asm/bitsperlong.h>


-- 
Thanks,
Changbin Du