On Mon, 2022-03-21 at 16:37 -0700, Andrii Nakryiko wrote: > On Mon, Mar 21, 2022 at 4:24 PM Andrii Nakryiko > <andrii.nakryiko@xxxxxxxxx> wrote: > > > > On Fri, Mar 18, 2022 at 12:13 PM Alexei Starovoitov > > <alexei.starovoitov@xxxxxxxxx> wrote: > > > > > > On Tue, Mar 15, 2022 at 05:42:30PM -0700, Kui-Feng Lee wrote: > > > > Add a bpf_cookie field to attach a cookie to an instance of > > > > struct > > > > bpf_link. The cookie of a bpf_link will be installed when > > > > calling the > > > > associated program to make it available to the program. > > > > > > > > Signed-off-by: Kui-Feng Lee <kuifeng@xxxxxx> > > > > --- > > > > arch/x86/net/bpf_jit_comp.c | 4 ++-- > > > > include/linux/bpf.h | 1 + > > > > include/uapi/linux/bpf.h | 1 + > > > > kernel/bpf/syscall.c | 11 +++++++---- > > > > kernel/trace/bpf_trace.c | 17 +++++++++++++++++ > > > > tools/include/uapi/linux/bpf.h | 1 + > > > > tools/lib/bpf/bpf.c | 14 ++++++++++++++ > > > > tools/lib/bpf/bpf.h | 1 + > > > > tools/lib/bpf/libbpf.map | 1 + > > > > 9 files changed, 45 insertions(+), 6 deletions(-) > > > > > > please split kernel and libbpf changes into two different > > > patches. > > > > > > > +1 > > > > > > diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c > > > > index f69ce3a01385..dbbf09c84c21 100644 > > > > --- a/tools/lib/bpf/bpf.c > > > > +++ b/tools/lib/bpf/bpf.c > > > > @@ -1133,6 +1133,20 @@ int bpf_raw_tracepoint_open(const char > > > > *name, int prog_fd) > > > > return libbpf_err_errno(fd); > > > > } > > > > > > > > +int bpf_raw_tracepoint_cookie_open(const char *name, int > > > > prog_fd, __u64 bpf_cookie) > > > > > > lets introduce opts style to raw_tp_open instead. > > > > I remember I brought this up earlier, but I forgot the outcome. > > What > > if don't touch BPF_RAW_TRACEPOINT_OPEN and instead allow to create > > all > > the same links through more universal BPF_LINK_CREATE command. And > > only there we add bpf_cookie? There are few advantages: > > > > 1. We can separate raw_tracepoint and trampoline-based programs > > more > > cleanly in UAPI (it will be two separate structs: > > link_create.raw_tp > > with raw tracepoint name vs link_create.trampoline, or whatever the > > name, with cookie and stuff). Remember that raw_tp won't support > > bpf_cookie for now, so it would be another advantage not to promise > > cookie in UAPI. > > > > 2. libbpf can be smart enough to pick either RAW_TRACEPOINT_OPEN > > (and > > reject it if bpf_cookie is non-zero) or BPF_LINK_CREATE, depending > > on > > kernel support. So users would need to only use bpf_link_create() > > moving forward with all the backwards compatibility preserved. > > > > > > Oh, and we need bpf_program__attach_trace_opts() as well (regardless > of whether it is BPF_RAW_TRACEPOINT_OPEN or BPF_LINK_CREATE). > > > I removed raw_tp_open_opts() since raw_tp won't support bpf_cookie. Implemented only bpf_program__attach_trace_opts().
