Re: [PATCH bpf] selftests/bpf: Fix xdp_synproxy compilation failure in 32-bit arch

[Yang Jihong]

Hello,

On 2022/11/8 23:59, Yonghong Song wrote:
> On 11/8/22 5:12 AM, Yang Jihong wrote:
> > xdp_synproxy fails to be compiled in the 32-bit arch, log is as follows:
> >
> >    xdp_synproxy.c: In function 'parse_options':
> >    xdp_synproxy.c:175:36: error: left shift count >= width of type 
> > [-Werror=shift-count-overflow]
> >      175 |                 *tcpipopts = (mss6 << 32) | (ttl << 24) | 
> > (wscale << 16) | mss4;
> >          |                                    ^~
> >    xdp_synproxy.c: In function 'syncookie_open_bpf_maps':
> >    xdp_synproxy.c:289:28: error: cast from pointer to integer of 
> > different size [-Werror=pointer-to-int-cast]
> >      289 |                 .map_ids = (__u64)map_ids,
> >          |                            ^
> >
> > Fix it.
> >
> > Fixes: fb5cd0ce70d4 ("selftests/bpf: Add selftests for raw syncookie 
> > helpers")
> > Signed-off-by: Yang Jihong <yangjihong1@xxxxxxxxxx>
> > ---
> >   tools/testing/selftests/bpf/xdp_synproxy.c | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/tools/testing/selftests/bpf/xdp_synproxy.c 
> > b/tools/testing/selftests/bpf/xdp_synproxy.c
> > index ff35320d2be9..45fef01a87a8 100644
> > --- a/tools/testing/selftests/bpf/xdp_synproxy.c
> > +++ b/tools/testing/selftests/bpf/xdp_synproxy.c
> > @@ -172,7 +172,7 @@ static void parse_options(int argc, char *argv[], 
> > unsigned int *ifindex, __u32 *
> >       if (tcpipopts_mask == 0xf) {
> >           if (mss4 == 0 || mss6 == 0 || wscale == 0 || ttl == 0)
> >               usage(argv[0]);
> > -        *tcpipopts = (mss6 << 32) | (ttl << 24) | (wscale << 16) | mss4;
> > +        *tcpipopts = ((unsigned long long)mss6 << 32) | (ttl << 24) | 
> > (wscale << 16) | mss4;
>
> This looks weird. Maybe we should define mss6 as unsigned long long to 
> avoid this casting at all?
OK, will fix in next version.

Thanks,
Yang