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

[Du, Changbin]

On Tue, Mar 27, 2018 at 11:52:27AM +0200, Daniel Borkmann wrote:
> On 03/27/2018 11:00 AM, Du, Changbin wrote:
> > 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 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?
> 
> E.g. take a look at tools/include/asm/barrier.h or tools/include/uapi/asm/bpf_perf_event.h
> just to name two examples. We'd need something similar to this which then points to the
> arch specific includes.
> 
> Thanks,
> Daniel
>
ok, I see. But I am going to skip this fix this time. Because one get fixed, another appears.
IMHO, It doesn't sound like a good idea to sync all these files manually. We should have
better solution I think.

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:12:
/usr/include/linux/ip.h:20:10: fatal error: 'asm/byteorder.h' file not found
#include <asm/byteorder.h>

 
> > 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