Re: [PATCH] selftests/bpf: Fix bind{4,6} tcp/socket header type conflict

[Martin KaFai Lau]

On Thu, Aug 25, 2022 at 11:31:15PM -0600, James Hilliard wrote:
> On Thu, Aug 25, 2022 at 11:16 PM Martin KaFai Lau <kafai@xxxxxx> wrote:
> >
> > On Thu, Aug 25, 2022 at 04:17:49PM -0600, James Hilliard wrote:
> > > There is a potential for us to hit a type conflict when including
> > > netinet/tcp.h with sys/socket.h, we can replace both of these includes
> > > with linux/tcp.h to avoid this conflict.
> > >
> > > Fixes errors like:
> > > In file included from /usr/include/netinet/tcp.h:91,
> > >                  from progs/bind4_prog.c:10:
> > > /home/buildroot/opt/cross/lib/gcc/bpf/13.0.0/include/stdint.h:34:23: error: conflicting types for 'int8_t'; have 'char'
> > >    34 | typedef __INT8_TYPE__ int8_t;
> > >       |                       ^~~~~~
> > > In file included from /usr/include/x86_64-linux-gnu/sys/types.h:155,
> > >                  from /usr/include/x86_64-linux-gnu/bits/socket.h:29,
> > >                  from /usr/include/x86_64-linux-gnu/sys/socket.h:33,
> > >                  from progs/bind4_prog.c:9:
> > > /usr/include/x86_64-linux-gnu/bits/stdint-intn.h:24:18: note: previous declaration of 'int8_t' with type 'int8_t' {aka 'signed char'}
> > >    24 | typedef __int8_t int8_t;
> > >       |                  ^~~~~~
> > > /home/buildroot/opt/cross/lib/gcc/bpf/13.0.0/include/stdint.h:43:24: error: conflicting types for 'int64_t'; have 'long int'
> > >    43 | typedef __INT64_TYPE__ int64_t;
> > >       |                        ^~~~~~~
> > > /usr/include/x86_64-linux-gnu/bits/stdint-intn.h:27:19: note: previous declaration of 'int64_t' with type 'int64_t' {aka 'long long int'}
> > >    27 | typedef __int64_t int64_t;
> > >       |                   ^~~~~~~
> > > make: *** [Makefile:537: /home/buildroot/bpf-next/tools/testing/selftests/bpf/bpf_gcc/bind4_prog.o] Error 1
> > >
> > > Signed-off-by: James Hilliard <james.hilliard1@xxxxxxxxx>
> > > ---
> > >  tools/testing/selftests/bpf/progs/bind4_prog.c | 3 +--
> > >  tools/testing/selftests/bpf/progs/bind6_prog.c | 3 +--
> > >  2 files changed, 2 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/tools/testing/selftests/bpf/progs/bind4_prog.c b/tools/testing/selftests/bpf/progs/bind4_prog.c
> > > index 474c6a62078a..6bd20042fd53 100644
> > > --- a/tools/testing/selftests/bpf/progs/bind4_prog.c
> > > +++ b/tools/testing/selftests/bpf/progs/bind4_prog.c
> > > @@ -6,8 +6,7 @@
> > >  #include <linux/bpf.h>
> > >  #include <linux/in.h>
> > >  #include <linux/in6.h>
> > > -#include <sys/socket.h>
> > > -#include <netinet/tcp.h>
> > These includes look normal to me.  What environment is hitting this.
> 
> I was hitting this error with GCC 13(GCC master branch).
These two includes (<sys/socket.h> and <netinet/tcp.h>) are normal,
so does it mean all existing programs need to change to use gcc 13 ?

> 
> > I don't prefer the selftest writers need to remember this rule.
> >
> > Beside, afaict, tcp.h should be removed because
> > I don't see this test needs it.  I tried removing it
> > and it works fine.  It should be removed instead of replacing it
> > with another unnecessary tcp.h.
> 
> Oh, that does also appear to work, thought I had tried that already but I guess
> I hadn't, sent a v2 with them removed:
> https://lore.kernel.org/bpf/20220826052925.980431-1-james.hilliard1@xxxxxxxxx/T/#u
> 
> >
> > > +#include <linux/tcp.h>
> > >  #include <linux/if.h>
> > >  #include <errno.h>
> > >
> > > diff --git a/tools/testing/selftests/bpf/progs/bind6_prog.c b/tools/testing/selftests/bpf/progs/bind6_prog.c
> > > index c19cfa869f30..f37617b35a55 100644
> > > --- a/tools/testing/selftests/bpf/progs/bind6_prog.c
> > > +++ b/tools/testing/selftests/bpf/progs/bind6_prog.c
> > > @@ -6,8 +6,7 @@
> > >  #include <linux/bpf.h>
> > >  #include <linux/in.h>
> > >  #include <linux/in6.h>
> > > -#include <sys/socket.h>
> > > -#include <netinet/tcp.h>
> > > +#include <linux/tcp.h>
> > >  #include <linux/if.h>
> > >  #include <errno.h>
> > >
> > > --
> > > 2.34.1
> > >