On Thu, Feb 5, 2026 at 12:57 AM Jiri Olsa <[email protected]> wrote: > > On Wed, Feb 04, 2026 at 11:04:09AM -0800, Andrii Nakryiko wrote: > > On Tue, Feb 3, 2026 at 1:39 AM Jiri Olsa <[email protected]> wrote: > > > > > > Adding btf__find_by_glob_kind function that returns array of > > > BTF ids that match given kind and allow/deny patterns. > > > > > > int btf__find_by_glob_kind(const struct btf *btf, __u32 kind, > > > const char *allow_pattern, > > > const char *deny_pattern, > > > __u32 **__ids); > > > > > > The __ids array is allocated and needs to be manually freed. > > > > > > The pattern check is done by glob_match function. > > > > > > Signed-off-by: Jiri Olsa <[email protected]> > > > --- > > > tools/lib/bpf/btf.c | 41 +++++++++++++++++++++++++++++++++++++++++ > > > tools/lib/bpf/btf.h | 3 +++ > > > 2 files changed, 44 insertions(+) > > > > > > diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c > > > index 83fe79ffcb8f..64502b3ef38a 100644 > > > --- a/tools/lib/bpf/btf.c > > > +++ b/tools/lib/bpf/btf.c > > > @@ -1010,6 +1010,47 @@ __s32 btf__find_by_name_kind(const struct btf > > > *btf, const char *type_name, > > > return btf_find_by_name_kind(btf, 1, type_name, kind); > > > } > > > > > > +int btf__find_by_glob_kind(const struct btf *btf, __u32 kind, > > > + const char *allow_pattern, const char > > > *deny_pattern, > > > + __u32 **__ids) > > > +{ > > > + __u32 i, nr_types = btf__type_cnt(btf); > > > + int cnt = 0, alloc = 0; > > > + __u32 *ids = NULL; > > > + > > > + for (i = 1; i < nr_types; i++) { > > > + const struct btf_type *t = btf__type_by_id(btf, i); > > > + const char *name; > > > + __u32 *p; > > > + > > > + if (btf_kind(t) != kind) > > > + continue; > > > + name = btf__name_by_offset(btf, t->name_off); > > > + if (!name) > > > + continue; > > > + > > > + if (deny_pattern && glob_match(name, deny_pattern)) > > > + continue; > > > + if (allow_pattern && !glob_match(name, allow_pattern)) > > > + continue; > > > + > > > + if (cnt == alloc) { > > > + alloc = max(16, alloc * 3 / 2); > > > + p = libbpf_reallocarray(ids, alloc, > > > sizeof(__u32)); > > > + if (!p) { > > > + free(ids); > > > + return -ENOMEM; > > > + } > > > + ids = p; > > > + } > > > + ids[cnt] = i; > > > + cnt++; > > > + } > > > + > > > + *__ids = ids; > > > + return cnt; > > > +} > > > + > > > static bool btf_is_modifiable(const struct btf *btf) > > > { > > > return (void *)btf->hdr != btf->raw_data; > > > diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h > > > index b30008c267c0..d7b47bb0ba99 100644 > > > --- a/tools/lib/bpf/btf.h > > > +++ b/tools/lib/bpf/btf.h > > > @@ -661,6 +661,9 @@ static inline struct btf_decl_tag *btf_decl_tag(const > > > struct btf_type *t) > > > return (struct btf_decl_tag *)(t + 1); > > > } > > > > > > +int btf__find_by_glob_kind(const struct btf *btf, __u32 kind, > > > + const char *allow_pattern, const char > > > *deny_pattern, > > > + __u32 **__ids); > > > > > > as AI pointed out, this should be an internal helper, no? Let's also > > not use double underscore pattern here, > > "collect_btf_ids_by_glob_kind()" perhaps? > > ok > > > > > Also, you don't seem to be using deny_pattern, where you planning to? > > the tests are just rudimentary before we agree we want to do it this way > > but I'm not sure I have a usecase for deny_pattern.. I think we added it > just to be complete, I recall we copied that function from somewhere, > it's long time ago ;-) > > > > > Also, are there functions that we'll have BTF for, but they won't be > > attachable? What if I do SEC("fentry.multi/*")? Will it attach or fail > > to attach some functions (and thus fail the overall attachment)? > > yes, for the benchmark tests I had to add is_allowed_func which mimics > btf_distill_func_proto and denies attach for some functions > > also I had to filter out some core kernel functions like rcu*,trace*,.. > which seemed to cause trouble when you attach them
So the question I'm implying here is if libbpf should do what we do for kprobes: use libbpf_available_kprobes_parse and intersect? > > jirka
