On Tue, Aug 16, 2022 at 2:49 PM Hao Luo <haoluo@xxxxxxxxxx> wrote: > > Add libbpf APIs for disabling auto-attach for individual functions. > This is motivated by the use case of cgroup iter [1]. Some iter > types require their parameters to be non-zero, therefore applying > auto-attach on them will fail. With these two new APIs, Users who > want to use auto-attach and these types of iters can disable > auto-attach for them and perform manual attach. > > [1] https://lore.kernel.org/bpf/CAEf4BzZ+a2uDo_t6kGBziqdz--m2gh2_EUwkGLDtMd65uwxUjA@xxxxxxxxxxxxxx/ > > Signed-off-by: Hao Luo <haoluo@xxxxxxxxxx> > --- > tools/lib/bpf/libbpf.c | 16 ++++++++++++++++ > tools/lib/bpf/libbpf.h | 2 ++ > 2 files changed, 18 insertions(+) > > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c > index aa05a99b913d..25f654d25b46 100644 > --- a/tools/lib/bpf/libbpf.c > +++ b/tools/lib/bpf/libbpf.c > @@ -417,6 +417,7 @@ struct bpf_program { > > int fd; > bool autoload; > + bool autoattach; > bool mark_btf_static; > enum bpf_prog_type type; > enum bpf_attach_type expected_attach_type; > @@ -755,6 +756,8 @@ bpf_object__init_prog(struct bpf_object *obj, struct bpf_program *prog, > prog->autoload = true; > } > > + prog->autoattach = true; > + > /* inherit object's log_level */ > prog->log_level = obj->log_level; > > @@ -8314,6 +8317,16 @@ int bpf_program__set_autoload(struct bpf_program *prog, bool autoload) > return 0; > } > > +bool bpf_program__autoattach(const struct bpf_program *prog) > +{ > + return prog->autoattach; > +} > + > +void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach) > +{ > + prog->autoattach = autoattach; > +} > + > const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog) > { > return prog->insns; > @@ -12349,6 +12362,9 @@ int bpf_object__attach_skeleton(struct bpf_object_skeleton *s) > if (!prog->autoload) > continue; > > + if (!prog->autoattach) > + continue; > + nit: I'd combine as if (!prog->autoload || !prog->autoattach), they are very coupled in this sense > /* auto-attaching not supported for this program */ > if (!prog->sec_def || !prog->sec_def->prog_attach_fn) > continue; > diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h > index 61493c4cddac..88a1ac34b12a 100644 > --- a/tools/lib/bpf/libbpf.h > +++ b/tools/lib/bpf/libbpf.h > @@ -260,6 +260,8 @@ LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog); > LIBBPF_API const char *bpf_program__section_name(const struct bpf_program *prog); > LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog); > LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload); > +LIBBPF_API bool bpf_program__autoattach(const struct bpf_program *prog); > +LIBBPF_API void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach); please add these APIs to libbpf.map as well it would be also nice to have a simple test validating that skeleton's auto-attach doesn't attach program (no link will be created) if bpf_program__set_autoattach(false) is called before. Can you please add that as well? > > struct bpf_insn; > > -- > 2.37.1.595.g718a3a8f04-goog >
