On Wed, Jul 28, 2021 at 9:55 AM Hengqi Chen <hengqi.chen@xxxxxxxxx> wrote: > > Add two new APIs: libbpf_load_vmlinux_btf/libbpf_load_module_btf. > libbpf_load_vmlinux_btf is just an alias to the existing API named > libbpf_find_kernel_btf, rename it to be more precisely. > libbpf_load_module_btf can be used to load module BTF, add it for > completeness. These two APIs are useful for implementing tracing > tools and introspection tools. > This is part of the efforts towards libbpf 1.0. [1] > > [1] https://github.com/libbpf/libbpf/issues/280 > > Signed-off-by: Hengqi Chen <hengqi.chen@xxxxxxxxx> > --- > tools/lib/bpf/btf.c | 15 ++++++++++++++- > tools/lib/bpf/btf.h | 2 ++ > tools/lib/bpf/libbpf.c | 4 ++-- > tools/lib/bpf/libbpf.map | 2 ++ > 4 files changed, 20 insertions(+), 3 deletions(-) > > diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c > index b46760b93bb4..5f801739a1a2 100644 > --- a/tools/lib/bpf/btf.c > +++ b/tools/lib/bpf/btf.c > @@ -4021,7 +4021,7 @@ static void btf_dedup_merge_hypot_map(struct btf_dedup *d) > */ > if (d->hypot_adjust_canon) > continue; > - > + > if (t_kind == BTF_KIND_FWD && c_kind != BTF_KIND_FWD) > d->map[t_id] = c_id; > > @@ -4395,6 +4395,11 @@ static int btf_dedup_remap_types(struct btf_dedup *d) > * data out of it to use for target BTF. > */ > struct btf *libbpf_find_kernel_btf(void) > +{ > + return libbpf_load_vmlinux_btf(); > +} > + > +struct btf *libbpf_load_vmlinux_btf(void) > { > struct { > const char *path_fmt; > @@ -4440,6 +4445,14 @@ struct btf *libbpf_find_kernel_btf(void) > return libbpf_err_ptr(-ESRCH); > } > > +struct btf *libbpf_load_module_btf(const char *module_name, struct btf *vmlinux_btf) In the light of Quentin's btf__load_from_kernel_by_id(), I'm now wondering if it's better to keep the naming consistent as btf__load_vmlinux_btf() and btf__load_module_btf()? And we should put them after btf__parse() family of constructors, as just another set of (special, but still) constructors. WDYT? Sorry for a bit of back and forth... Otherwise everything looks good, thanks. > +{ > + char path[80]; > + > + snprintf(path, sizeof(path), "/sys/kernel/btf/%s", module_name); > + return btf__parse_split(path, vmlinux_btf); > +} > + > int btf_type_visit_type_ids(struct btf_type *t, type_id_visit_fn visit, void *ctx) > { > int i, n, err; > diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h > index 374e9f15de2e..1abf94e3bd9e 100644 > --- a/tools/lib/bpf/btf.h > +++ b/tools/lib/bpf/btf.h > @@ -90,6 +90,8 @@ LIBBPF_API __u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext); > LIBBPF_API __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext); > > LIBBPF_API struct btf *libbpf_find_kernel_btf(void); > +LIBBPF_API struct btf *libbpf_load_vmlinux_btf(void); > +LIBBPF_API struct btf *libbpf_load_module_btf(const char *module_name, struct btf *vmlinux_btf); as mentioned above, let's move these right after btf__parse() family, so that all BTF constructor APIs are listed first. > > LIBBPF_API int btf__find_str(struct btf *btf, const char *s); > LIBBPF_API int btf__add_str(struct btf *btf, const char *s); > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c > index a1ca6fb0c6d8..321d8f4889af 100644 > --- a/tools/lib/bpf/libbpf.c > +++ b/tools/lib/bpf/libbpf.c > @@ -2680,7 +2680,7 @@ static int bpf_object__load_vmlinux_btf(struct bpf_object *obj, bool force) > if (!force && !obj_needs_vmlinux_btf(obj)) > return 0; > > - obj->btf_vmlinux = libbpf_find_kernel_btf(); > + obj->btf_vmlinux = libbpf_load_vmlinux_btf(); > err = libbpf_get_error(obj->btf_vmlinux); > if (err) { > pr_warn("Error loading vmlinux BTF: %d\n", err); > @@ -8297,7 +8297,7 @@ int libbpf_find_vmlinux_btf_id(const char *name, > struct btf *btf; > int err; > > - btf = libbpf_find_kernel_btf(); > + btf = libbpf_load_vmlinux_btf(); > err = libbpf_get_error(btf); > if (err) { > pr_warn("vmlinux BTF is not found\n"); > diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map > index c240d488eb5e..2088bdbc0f50 100644 > --- a/tools/lib/bpf/libbpf.map > +++ b/tools/lib/bpf/libbpf.map > @@ -377,4 +377,6 @@ LIBBPF_0.5.0 { > bpf_object__gen_loader; > btf_dump__dump_type_data; > libbpf_set_strict_mode; > + libbpf_load_vmlinux_btf; > + libbpf_load_module_btf; > } LIBBPF_0.4.0; > -- > 2.25.1 >
