On Tue, May 12, 2020 at 10:34:58AM +0200, Toke Høiland-Jørgensen wrote: > Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> writes: > > >> > Currently fentry/fexit/freplace progs have single prog->aux->linked_prog pointer. > >> > It just needs to become a linked list. > >> > The api extension could be like this: > >> > bpf_raw_tp_open(prog_fd, attach_prog_fd, attach_btf_id); > >> > (currently it's just bpf_raw_tp_open(prog_fd)) > >> > The same pair of (attach_prog_fd, attach_btf_id) is already passed into prog_load > >> > to hold the linked_prog and its corresponding btf_id. > >> > I'm proposing to extend raw_tp_open with this pair as well to > >> > attach existing fentry/fexit/freplace prog to another target. > >> > Internally the kernel verify that btf of current linked_prog > >> > exactly matches to btf of another requested linked_prog and > >> > if they match it will attach the same prog to two target programs (in case of freplace) > >> > or two kernel functions (in case of fentry/fexit). > >> > >> API-wise this was exactly what I had in mind as well. > > > > perfect! > > Hi Alexei > > I don't suppose you've had a chance to whip up a patch for this, have > you? :) On my priority list it's after cap_bpf and sleepable. If it's urgent for you please start hacking.
