In symmetry with bpf_object__open_skeleton(),
bpf_object__open_subskeleton() performs the actual walking and linking
of maps, progs, and globals described by bpf_*_skeleton objects.
Signed-off-by: Delyan Kratunov <delyank@xxxxxx>
---
tools/lib/bpf/libbpf.c | 136 +++++++++++++++++++++++++++++++++------
tools/lib/bpf/libbpf.h | 29 +++++++++
tools/lib/bpf/libbpf.map | 2 +
3 files changed, 146 insertions(+), 21 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 3fb9c926fe6e..ba7b25b11486 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -11810,6 +11810,49 @@ int libbpf_num_possible_cpus(void)
return tmp_cpus;
}
+static int populate_skeleton_maps(const struct bpf_object* obj,
+ struct bpf_map_skeleton* maps,
+ size_t map_cnt)
+{
+ int i;
+
+ for (i = 0; i < map_cnt; i++) {
+ struct bpf_map **map = maps[i].map;
+ const char *name = maps[i].name;
+ void **mmaped = maps[i].mmaped;
+
+ *map = bpf_object__find_map_by_name(obj, name);
+ if (!*map) {
+ pr_warn("failed to find skeleton map '%s'\n", name);
+ return libbpf_err(-ESRCH);
+ }
+
+ /* externs shouldn't be pre-setup from user code */
+ if (mmaped && (*map)->libbpf_type != LIBBPF_MAP_KCONFIG)
+ *mmaped = (*map)->mmaped;
+ }
+ return 0;
+}
+
+static int populate_skeleton_progs(const struct bpf_object* obj,
+ struct bpf_prog_skeleton* progs,
+ size_t prog_cnt)
+{
+ int i;
+
+ for (i = 0; i < prog_cnt; i++) {
+ struct bpf_program **prog = progs[i].prog;
+ const char *name = progs[i].name;
+
+ *prog = bpf_object__find_program_by_name(obj, name);
+ if (!*prog) {
+ pr_warn("failed to find skeleton program '%s'\n", name);
+ return libbpf_err(-ESRCH);
+ }
+ }
+ return 0;
+}
+
int bpf_object__open_skeleton(struct bpf_object_skeleton *s,
const struct bpf_object_open_opts *opts)
{
@@ -11817,7 +11860,7 @@ int bpf_object__open_skeleton(struct bpf_object_skeleton *s,
.object_name = s->name,
);
struct bpf_object *obj;
- int i, err;
+ int err;
/* Attempt to preserve opts->object_name, unless overriden by user
* explicitly. Overwriting object name for skeletons is discouraged,
@@ -11840,37 +11883,88 @@ int bpf_object__open_skeleton(struct bpf_object_skeleton *s,
}
*s->obj = obj;
+ err = populate_skeleton_maps(obj, s->maps, s->map_cnt);
+ if (err) {
+ pr_warn("failed to populate skeleton maps for '%s': %d\n",
+ s->name, err);
+ return libbpf_err(err);
+ }
- for (i = 0; i < s->map_cnt; i++) {
- struct bpf_map **map = s->maps[i].map;
- const char *name = s->maps[i].name;
- void **mmaped = s->maps[i].mmaped;
+ err = populate_skeleton_progs(obj, s->progs, s->prog_cnt);
+ if (err) {
+ pr_warn("failed to populate skeleton progs for '%s': %d\n",
+ s->name, err);
+ return libbpf_err(err);
+ }
- *map = bpf_object__find_map_by_name(obj, name);
- if (!*map) {
- pr_warn("failed to find skeleton map '%s'\n", name);
- return libbpf_err(-ESRCH);
- }
+ return 0;
+}
- /* externs shouldn't be pre-setup from user code */
- if (mmaped && (*map)->libbpf_type != LIBBPF_MAP_KCONFIG)
- *mmaped = (*map)->mmaped;
+int bpf_object__open_subskeleton(struct bpf_object_subskeleton *s)
+{
+ int err, len, var_idx, i;
+ const char *var_name;
+ const struct bpf_map *map;
+ struct btf *btf;
+ __u32 map_type_id;
+ const struct btf_type *map_type, *var_type;
+ const struct bpf_var_skeleton *var_skel;
+ struct btf_var_secinfo *var;
+
+ if (!s->obj)
+ return libbpf_err(-EINVAL);
+
+ btf = bpf_object__btf(s->obj);
+ if (!btf)
+ return -errno;
+
+ err = populate_skeleton_maps(s->obj, s->maps, s->map_cnt);
+ if (err) {
+ pr_warn("failed to populate subskeleton maps: %d\n", err);
+ return libbpf_err(err);
}
- for (i = 0; i < s->prog_cnt; i++) {
- struct bpf_program **prog = s->progs[i].prog;
- const char *name = s->progs[i].name;
+ err = populate_skeleton_progs(s->obj, s->progs, s->prog_cnt);
+ if (err) {
+ pr_warn("failed to populate subskeleton maps: %d\n", err);
+ return libbpf_err(err);
+ }
- *prog = bpf_object__find_program_by_name(obj, name);
- if (!*prog) {
- pr_warn("failed to find skeleton program '%s'\n", name);
- return libbpf_err(-ESRCH);
+ for (var_idx = 0; var_idx < s->var_cnt; var_idx++) {
+ var_skel = &s->vars[var_idx];
+ map = *var_skel->map;
+ map_type_id = bpf_map__btf_value_type_id(map);
+ map_type = btf__type_by_id(btf, map_type_id);
+
+ len = btf_vlen(map_type);
+ var = btf_var_secinfos(map_type);
+ for (i = 0; i < len; i++, var++) {
+ var_type = btf__type_by_id(btf, var->type);
+ if (!var_type) {
+ pr_warn("Could not find var type for item %1$d in section %2$s",
+ i, bpf_map__name(map));
+ return libbpf_err(-EINVAL);
+ }
+ var_name = btf__name_by_offset(btf, var_type->name_off);
+ if (strcmp(var_name, var_skel->name) == 0) {
+ *var_skel->addr = (char *) map->mmaped + var->offset;
+ break;
+ }
}
}
-
return 0;
}
+void bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s)
+{
+ if (!s)
+ return;
+ free(s->maps);
+ free(s->progs);
+ free(s->vars);
+ free(s);
+}
+
int bpf_object__load_skeleton(struct bpf_object_skeleton *s)
{
int i, err;
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index c1b0c2ef14d8..1bff7647d797 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -1289,6 +1289,35 @@ LIBBPF_API int bpf_object__attach_skeleton(struct bpf_object_skeleton *s);
LIBBPF_API void bpf_object__detach_skeleton(struct bpf_object_skeleton *s);
LIBBPF_API void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s);
+struct bpf_var_skeleton {
+ const char *name;
+ struct bpf_map **map;
+ void **addr;
+};
+
+struct bpf_object_subskeleton {
+ size_t sz; /* size of this struct, for forward/backward compatibility */
+
+ const struct bpf_object *obj;
+
+ int map_cnt;
+ int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */
+ struct bpf_map_skeleton *maps;
+
+ int prog_cnt;
+ int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */
+ struct bpf_prog_skeleton *progs;
+
+ int var_cnt;
+ int var_skel_sz; /* sizeof(struct bpf_var_skeleton) */
+ struct bpf_var_skeleton *vars;
+};
+
+LIBBPF_API int
+bpf_object__open_subskeleton(struct bpf_object_subskeleton *s);
+LIBBPF_API void
+bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s);
+
struct gen_loader_opts {
size_t sz; /* size of this struct, for forward/backward compatiblity */
const char *data;
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index df1b947792c8..d744fbb8612e 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -442,6 +442,8 @@ LIBBPF_0.7.0 {
LIBBPF_0.8.0 {
global:
+ bpf_object__open_subskeleton;
+ bpf_object__destroy_subskeleton;
libbpf_register_prog_handler;
libbpf_unregister_prog_handler;
} LIBBPF_0.7.0;
--
2.34.1
