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.
I'm not sure this was on purpose, but seems as natural use of the interface, although the only user is the test for now. You need to have patch [1] from bpf tree for test module attach test to pass. thanks, jirka [1] https://lore.kernel.org/bpf/20210326105900.151466-1-jo...@kernel.org/ --- Jiri Olsa (4): bpf: Allow trampoline re-attach selftests/bpf: Add re-attach test to fentry_test selftests/bpf: Add re-attach test to fexit_test selftests/bpf: Test that module can't be unloaded with attached trampoline kernel/bpf/syscall.c | 25 +++++++++++++++++++------ kernel/bpf/trampoline.c | 2 +- tools/testing/selftests/bpf/prog_tests/fentry_test.c | 58 +++++++++++++++++++++++++++++++++++++++++++++------------- tools/testing/selftests/bpf/prog_tests/fexit_test.c | 58 +++++++++++++++++++++++++++++++++++++++++++++------------- tools/testing/selftests/bpf/prog_tests/module_attach.c | 23 +++++++++++++++++++++++ 5 files changed, 133 insertions(+), 33 deletions(-)
