[ will fix all your comments above ] >> @@ -3924,10 +3983,16 @@ static int tracing_bpf_link_attach(const union bpf_attr *attr, struct bpf_prog * >> prog->expected_attach_type == BPF_TRACE_ITER) >> return bpf_iter_link_attach(attr, prog); >> >> + if (attr->link_create.attach_type == BPF_TRACE_FREPLACE && >> + !prog->expected_attach_type) >> + return bpf_tracing_prog_attach(prog, >> + attr->link_create.target_fd, >> + attr->link_create.target_btf_id); > > Hm.. so you added a "fake" BPF_TRACE_FREPLACE attach_type, which is > not really set with BPF_PROG_TYPE_EXT and is only specified for the > LINK_CREATE command. Are you just trying to satisfy the link_create > flow of going from attach_type to program type? If that's the only > reason, I think we can adjust link_create code to handle this more > flexibly. > > I need to think a bit more whether we want BPF_TRACE_FREPLACE at all, > but if we do, whether we should make it an expected_attach_type for > BPF_PROG_TYPE_EXT then... Yeah, wasn't too sure about this. But attach_type seemed to be the only way to disambiguate between the different link types in the LINK_CREATE command, so went with that. Didn't think too much about it, TBH :) I guess an alternative could be to just enforce attach_type==0 and look at prog->type? Or if you have any other ideas, I'm all ears! -Toke
