hi,
while adding test for pinning the module while there's
trampoline attach to it, I noticed that we don't allow
link detach and following re-attach for trampolines.
Adding that for tracing and lsm programs.

You need to have patch [1] from bpf tree for test module
attach test to pass.

v5 changes:
  - fixed missing hlist_del_init change
  - fixed several ASSERT calls
  - added extra patch for missing ';'
  - added ASSERT macros to lsm test
  - added acks

thanks,
jirka


[1] https://lore.kernel.org/bpf/20210326105900.151466-1-jolsa@kernel.org/ (local)
---
Jiri Olsa (7):
      bpf: Allow trampoline re-attach for tracing and lsm programs
      selftests/bpf: Add missing semicolon
      selftests/bpf: Add re-attach test to fentry_test
      selftests/bpf: Add re-attach test to fexit_test
      selftests/bpf: Add re-attach test to lsm test
      selftests/bpf: Test that module can't be unloaded with attached trampoline
      selftests/bpf: Use ASSERT macros in lsm test

 kernel/bpf/syscall.c                                   | 23 +++++++++++++++++------
 kernel/bpf/trampoline.c                                |  4 ++--
 tools/testing/selftests/bpf/prog_tests/fentry_test.c   | 52 +++++++++++++++++++++++++++++++++++++---------------
 tools/testing/selftests/bpf/prog_tests/fexit_test.c    | 52 +++++++++++++++++++++++++++++++++++++---------------
 tools/testing/selftests/bpf/prog_tests/module_attach.c | 23 +++++++++++++++++++++++
 tools/testing/selftests/bpf/prog_tests/test_lsm.c      | 61 +++++++++++++++++++++++++++++++++++++++++--------------------
 tools/testing/selftests/bpf/test_progs.h               |  2 +-
 7 files changed, 158 insertions(+), 59 deletions(-)