Re: [PATCHv2] selftests: bpf: xskxceiver: ksft_print_msg: fix format type error

[Magnus Karlsson]

On Wed, 8 Nov 2023 at 18:03, Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> wrote:
>
> On Wed, Nov 8, 2023 at 3:00 AM Anders Roxell <anders.roxell@xxxxxxxxxx> wrote:
> >
> > Crossbuilding selftests/bpf for architecture arm64, format specifies
> > type error show up like.
> >
> > xskxceiver.c:912:34: error: format specifies type 'int' but the argument
> > has type '__u64' (aka 'unsigned long long') [-Werror,-Wformat]
> >  ksft_print_msg("[%s] expected meta_count [%d], got meta_count [%d]\n",
> >                                                                 ~~
> >                                                                 %llu
> >                 __func__, pkt->pkt_nb, meta->count);
> >                                        ^~~~~~~~~~~
> > xskxceiver.c:929:55: error: format specifies type 'unsigned long long' but
> >  the argument has type 'u64' (aka 'unsigned long') [-Werror,-Wformat]
> >  ksft_print_msg("Frag invalid addr: %llx len: %u\n", addr, len);
> >                                     ~~~~             ^~~~
> >
> > Fixing the issues by casting to (unsigned long long) and changing the
> > specifiers to be %llx, since with u64s it might be %llx or %lx,
> > depending on architecture.
> >
> > Signed-off-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
> > ---
> >  tools/testing/selftests/bpf/xskxceiver.c | 19 ++++++++++++-------
> >  1 file changed, 12 insertions(+), 7 deletions(-)
> >
> > diff --git a/tools/testing/selftests/bpf/xskxceiver.c b/tools/testing/selftests/bpf/xskxceiver.c
> > index 591ca9637b23..1ab9512f5aa2 100644
> > --- a/tools/testing/selftests/bpf/xskxceiver.c
> > +++ b/tools/testing/selftests/bpf/xskxceiver.c
> > @@ -908,8 +908,9 @@ static bool is_metadata_correct(struct pkt *pkt, void *buffer, u64 addr)
> >         struct xdp_info *meta = data - sizeof(struct xdp_info);
> >
> >         if (meta->count != pkt->pkt_nb) {
> > -               ksft_print_msg("[%s] expected meta_count [%d], got meta_count [%d]\n",
> > -                              __func__, pkt->pkt_nb, meta->count);
> > +               ksft_print_msg("[%s] expected meta_count [%d], got meta_count [%llx]\n",
>
> why hex? %llu?

You are correct, it should be %llu in both these cases. The original
%d was incorrect here and good that it was corrected to a 64-bit
unsigned.

>
> > +                              __func__, pkt->pkt_nb,
> > +                              (unsigned long long)meta->count);
> >                 return false;
> >         }
> >
> > @@ -926,11 +927,13 @@ static bool is_frag_valid(struct xsk_umem_info *umem, u64 addr, u32 len, u32 exp
> >
> >         if (addr >= umem->num_frames * umem->frame_size ||
> >             addr + len > umem->num_frames * umem->frame_size) {
> > -               ksft_print_msg("Frag invalid addr: %llx len: %u\n", addr, len);
> > +               ksft_print_msg("Frag invalid addr: %llx len: %u\n",
> > +                              (unsigned long long)addr, len);
> >                 return false;
> >         }
> >         if (!umem->unaligned_mode && addr % umem->frame_size + len > umem->frame_size) {
> > -               ksft_print_msg("Frag crosses frame boundary addr: %llx len: %u\n", addr, len);
> > +               ksft_print_msg("Frag crosses frame boundary addr: %llx len: %u\n",
> > +                              (unsigned long long)addr, len);
> >                 return false;
> >         }
> >
> > @@ -1029,7 +1032,8 @@ static int complete_pkts(struct xsk_socket_info *xsk, int batch_size)
> >                         u64 addr = *xsk_ring_cons__comp_addr(&xsk->umem->cq, idx + rcvd - 1);
> >
> >                         ksft_print_msg("[%s] Too many packets completed\n", __func__);
> > -                       ksft_print_msg("Last completion address: %llx\n", addr);
> > +                       ksft_print_msg("Last completion address: %llx\n",
> > +                                      (unsigned long long)addr);
> >                         return TEST_FAILURE;
> >                 }
> >
> > @@ -1513,8 +1517,9 @@ static int validate_tx_invalid_descs(struct ifobject *ifobject)
> >         }
> >
> >         if (stats.tx_invalid_descs != ifobject->xsk->pkt_stream->nb_pkts / 2) {
> > -               ksft_print_msg("[%s] tx_invalid_descs incorrect. Got [%u] expected [%u]\n",
> > -                              __func__, stats.tx_invalid_descs,
> > +               ksft_print_msg("[%s] tx_invalid_descs incorrect. Got [%llx] expected [%u]\n",
>
> should this be %llu? Or the switch to the hex was intentional?

Same thing here. The original %u should really have been %llu since
the stats is 64-bits. But no reason for the hex here since it is not
an address.

> > +                              __func__,
> > +                              (unsigned long long)stats.tx_invalid_descs,
> >                                ifobject->xsk->pkt_stream->nb_pkts);
> >                 return TEST_FAILURE;
> >         }
> > --
> > 2.42.0
> >
>