> From: Alexei Starovoitov [mailto:alexei.starovoitov@xxxxxxxxx] > Sent: Friday, July 22, 2022 8:02 PM > On Fri, Jul 22, 2022 at 10:58 AM Stanislav Fomichev <sdf@xxxxxxxxxx> wrote: > > > > On Fri, Jul 22, 2022 at 10:20 AM Roberto Sassu <roberto.sassu@xxxxxxxxxx> > wrote: > > > > > > Introduce bpf_obj_get_opts(), to let the caller pass the needed permissions > > > for the operation. Keep the existing bpf_obj_get() to request read-write > > > permissions. > > > > > > bpf_obj_get() allows the caller to get a file descriptor from a pinned > > > object with the provided pathname. Specifying permissions has only effect > > > on maps (for links, the permission must be always read-write). > > > > > > Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx> > > > --- > > > tools/lib/bpf/bpf.c | 12 +++++++++++- > > > tools/lib/bpf/bpf.h | 2 ++ > > > tools/lib/bpf/libbpf.map | 1 + > > > 3 files changed, 14 insertions(+), 1 deletion(-) > > > > > > diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c > > > index 5f2785a4c358..0df088890864 100644 > > > --- a/tools/lib/bpf/bpf.c > > > +++ b/tools/lib/bpf/bpf.c > > > @@ -577,18 +577,28 @@ int bpf_obj_pin(int fd, const char *pathname) > > > return libbpf_err_errno(ret); > > > } > > > > > > -int bpf_obj_get(const char *pathname) > > > +int bpf_obj_get_opts(const char *pathname, > > > + const struct bpf_get_fd_opts *opts) > > > > I'm still not sure whether it's a good idea to mix get_fd with > > obj_get/pin operations? [1] seems more clear. > > +1 I think so. Both types of functions are accessing the same object, just in a different way: one by ID, and another by path. Consider the case I mentioned, map_parse_fds() in bpftool. It calls both type of functions. What opts a caller of this function should provide, if they are different? > > It just so happens that (differently named) flags in BPF_OBJ_GET and > > BPF_XXX_GET_FD_BY_ID align, but maybe we shouldn't depend on it? > > > > Also, it seems only bpf_map_get_fd_by_id currently accepts flags? So > > this sharing makes even more sense? As I mentioned in another email, Andrii requested me in v2 to add opts to all bpf_*_get_fd_by_id() functions. > +1 > > Roberto, the patch set is broken in many ways. Could you please explain? Thanks Roberto
