Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> writes: > 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. OK, ACK. Not extremely urgent right now, just wanted to check in with what your plans were. Thanks for letting me know! -Toke
