[RFC PATCH] bpf: test case for kcm + sockmap

[John Fastabend <john.fastabend@gmail.com>]

This finds the issue with kcm and sockmap where when a kcm socket is
added to a sockmap we fail to notice it is a kcm sock and not a tcp
bpf ULP sock. This results in a refcount_inc_not_zero() being called
on the psock which is assigned to a smap_psock incorrectly. On my
system it just happens to fail there and returns EAGAIN.

With the fix, just submitted for bpf tree, we get the correct EBUSY
error.

https://patchwork.ozlabs.org/project/netdev/list/?series=63393

RFC for now and will submit properly when bpf fix makes its way into
bpf-next. But, wanted to get the test on the list for folks to look
at.

---

John Fastabend (1):
      bpf: test_maps add a test to catch kcm + sockmap


 tools/testing/selftests/bpf/Makefile    |    2 -
 tools/testing/selftests/bpf/test_maps.c |   64 ++++++++++++++++++++++++++++++-
 2 files changed, 63 insertions(+), 3 deletions(-)