On Wed, Nov 23, 2022 at 12:08 PM Stanislav Fomichev <sdf@xxxxxxxxxx> wrote: > > Jiri reports broken test_progs after recent commit 68f8e3d4b916 > ("selftests/bpf: Make sure zero-len skbs aren't redirectable"). > Apparently we don't remount debugfs when we switch back networking namespace. > Let's explicitly mount /sys/kernel/debug. > > 0: https://lore.kernel.org/bpf/63b85917-a2ea-8e35-620c-808560910819@xxxxxxxx/T/#ma66ca9c92e99eee0a25e40f422489b26ee0171c1 > > Fixes: a30338840fa5 ("selftests/bpf: Move open_netns() and close_netns() into network_helpers.c") > Reported-by: Jiri Olsa <olsajiri@xxxxxxxxx> > Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxx> > --- > tools/testing/selftests/bpf/network_helpers.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c > index bec15558fd93..1f37adff7632 100644 > --- a/tools/testing/selftests/bpf/network_helpers.c > +++ b/tools/testing/selftests/bpf/network_helpers.c > @@ -426,6 +426,10 @@ static int setns_by_fd(int nsfd) > if (!ASSERT_OK(err, "mount /sys/fs/bpf")) > return err; > > + err = mount("debugfs", "/sys/kernel/debug", "debugfs", 0, NULL); > + if (!ASSERT_OK(err, "mount /sys/kernel/debug")) > + return err; > + > return 0; > } Thanks. It fixes part of it but it's still racy. I see: do_read:FAIL:open open /sys/fs/bpf/bpf_iter_test1 failed: No such file or directory I suspect it happens when iter tests are running while test_empty_skb is cleaning the netns. So I've added: -void test_empty_skb(void) +void serial_test_empty_skb(void) -void test_xdp_do_redirect(void) +void serial_test_xdp_do_redirect(void) -void test_xdp_synproxy(void) +void serial_test_xdp_synproxy(void) to stop the bleeding and applied.