perf bpf: Stop using deprecated bpf_object__next() API

Libbpf has deprecated the ability to keep track of object list inside
libbpf, it now requires applications to track usage multiple bpf objects
directly. Remove usage of bpf_object__next() API and hoist the tracking
logic to perf.

Signed-off-by: Christy Lee <christylee@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: bpf@vger.kernel.org
Cc: kernel-team@fb.com
Link: https://lore.kernel.org/bpf/20220212073054.1052880-3-andrii@kernel.org
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index 7ecfaac..db61e09 100644 (file)
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -49,8 +49,52 @@ struct bpf_prog_priv {
        int *type_mapping;
 };
 
+struct bpf_perf_object {
+       struct list_head list;
+       struct bpf_object *obj;
+};
+
+static LIST_HEAD(bpf_objects_list);
+
+static struct bpf_perf_object *
+bpf_perf_object__next(struct bpf_perf_object *prev)
+{
+       struct bpf_perf_object *next;
+
+       if (!prev)
+               next = list_first_entry(&bpf_objects_list,
+                                       struct bpf_perf_object,
+                                       list);
+       else
+               next = list_next_entry(prev, list);
+
+       /* Empty list is noticed here so don't need checking on entry. */
+       if (&next->list == &bpf_objects_list)
+               return NULL;
+
+       return next;
+}
+
+#define bpf_perf_object__for_each(perf_obj, tmp)       \
+       for ((perf_obj) = bpf_perf_object__next(NULL),  \
+            (tmp) = bpf_perf_object__next(perf_obj);   \
+            (perf_obj) != NULL;                        \
+            (perf_obj) = (tmp), (tmp) = bpf_perf_object__next(tmp))
+
 static bool libbpf_initialized;
 
+static int bpf_perf_object__add(struct bpf_object *obj)
+{
+       struct bpf_perf_object *perf_obj = zalloc(sizeof(*perf_obj));
+
+       if (perf_obj) {
+               INIT_LIST_HEAD(&perf_obj->list);
+               perf_obj->obj = obj;
+               list_add_tail(&perf_obj->list, &bpf_objects_list);
+       }
+       return perf_obj ? 0 : -ENOMEM;
+}
+
 struct bpf_object *
 bpf__prepare_load_buffer(void *obj_buf, size_t obj_buf_sz, const char *name)
 {
@@ -67,9 +111,21 @@ bpf__prepare_load_buffer(void *obj_buf, size_t obj_buf_sz, const char *name)
                return ERR_PTR(-EINVAL);
        }
 
+       if (bpf_perf_object__add(obj)) {
+               bpf_object__close(obj);
+               return ERR_PTR(-ENOMEM);
+       }
+
        return obj;
 }
 
+static void bpf_perf_object__close(struct bpf_perf_object *perf_obj)
+{
+       list_del(&perf_obj->list);
+       bpf_object__close(perf_obj->obj);
+       free(perf_obj);
+}
+
 struct bpf_object *bpf__prepare_load(const char *filename, bool source)
 {
        struct bpf_object *obj;
@@ -100,24 +156,30 @@ struct bpf_object *bpf__prepare_load(const char *filename, bool source)
                        llvm__dump_obj(filename, obj_buf, obj_buf_sz);
 
                free(obj_buf);
-       } else
+       } else {
                obj = bpf_object__open(filename);
+       }
 
        if (IS_ERR_OR_NULL(obj)) {
                pr_debug("bpf: failed to load %s\n", filename);
                return obj;
        }
 
+       if (bpf_perf_object__add(obj)) {
+               bpf_object__close(obj);
+               return ERR_PTR(-BPF_LOADER_ERRNO__COMPILE);
+       }
+
        return obj;
 }
 
 void bpf__clear(void)
 {
-       struct bpf_object *obj, *tmp;
+       struct bpf_perf_object *perf_obj, *tmp;
 
-       bpf_object__for_each_safe(obj, tmp) {
-               bpf__unprobe(obj);
-               bpf_object__close(obj);
+       bpf_perf_object__for_each(perf_obj, tmp) {
+               bpf__unprobe(perf_obj->obj);
+               bpf_perf_object__close(perf_obj);
        }
 }
 
@@ -1501,11 +1563,11 @@ apply_obj_config_object(struct bpf_object *obj)
 
 int bpf__apply_obj_config(void)
 {
-       struct bpf_object *obj, *tmp;
+       struct bpf_perf_object *perf_obj, *tmp;
        int err;
 
-       bpf_object__for_each_safe(obj, tmp) {
-               err = apply_obj_config_object(obj);
+       bpf_perf_object__for_each(perf_obj, tmp) {
+               err = apply_obj_config_object(perf_obj->obj);
                if (err)
                        return err;
        }
@@ -1513,26 +1575,24 @@ int bpf__apply_obj_config(void)
        return 0;
 }
 
-#define bpf__for_each_map(pos, obj, objtmp)    \
-       bpf_object__for_each_safe(obj, objtmp)  \
-               bpf_object__for_each_map(pos, obj)
+#define bpf__perf_for_each_map(map, pobj, tmp)                 \
+       bpf_perf_object__for_each(pobj, tmp)                    \
+               bpf_object__for_each_map(map, pobj->obj)
 
-#define bpf__for_each_map_named(pos, obj, objtmp, name)        \
-       bpf__for_each_map(pos, obj, objtmp)             \
-               if (bpf_map__name(pos) &&               \
-                       (strcmp(name,                   \
-                               bpf_map__name(pos)) == 0))
+#define bpf__perf_for_each_map_named(map, pobj, pobjtmp, name) \
+       bpf__perf_for_each_map(map, pobj, pobjtmp)              \
+               if (bpf_map__name(map) && (strcmp(name, bpf_map__name(map)) == 0))
 
 struct evsel *bpf__setup_output_event(struct evlist *evlist, const char *name)
 {
        struct bpf_map_priv *tmpl_priv = NULL;
-       struct bpf_object *obj, *tmp;
+       struct bpf_perf_object *perf_obj, *tmp;
        struct evsel *evsel = NULL;
        struct bpf_map *map;
        int err;
        bool need_init = false;
 
-       bpf__for_each_map_named(map, obj, tmp, name) {
+       bpf__perf_for_each_map_named(map, perf_obj, tmp, name) {
                struct bpf_map_priv *priv = bpf_map__priv(map);
 
                if (IS_ERR(priv))
@@ -1568,7 +1628,7 @@ struct evsel *bpf__setup_output_event(struct evlist *evlist, const char *name)
                evsel = evlist__last(evlist);
        }
 
-       bpf__for_each_map_named(map, obj, tmp, name) {
+       bpf__perf_for_each_map_named(map, perf_obj, tmp, name) {
                struct bpf_map_priv *priv = bpf_map__priv(map);
 
                if (IS_ERR(priv))