Em Tue, Jan 19, 2021 at 12:48:19AM +0000, Song Liu escreveu: > > On Jan 18, 2021, at 11:38 AM, Arnaldo Carvalho de Melo <a...@kernel.org> > > wrote: > We are looking at two issues: > 1. Cannot recursively attach; > 2. prog FD 3 doesn't have valid btf. > #1 was caused by the verifier disallowing attaching fentry/fexit program > to program with type BPF_PROG_TYPE_TRACING (in bpf_check_attach_target). > This constraint was added when we only had fentry/fexit in the TRACING > type. We have extended the TRACING type to many other use cases, like > "tp_btf/", "fmod_ret" and "iter/". Therefore, it is good time to revisit > this constraint. I will work on this. > For #2, we require the target program to have BTF. I guess we won't remove > this requirement. > While I work on improving #1, could you please test with some kprobe > programs? For example, we can use fileslower.py from bcc.
Sure, and please consider improving the error messages to state what you described above. - Arnaldo
