libbpf: Deprecate bpf_object__unload() API since v0.6

BPF objects are not reloadable after unload. Users are expected to use
bpf_object__close() to unload and free up resources in one operation.
No need to expose bpf_object__unload() as a public API, deprecate it
([0]).  Add bpf_object__unload() as an alias to internal
bpf_object_unload() and replace all bpf_object__unload() uses to avoid
compilation errors.

  [0] Closes: https://github.com/libbpf/libbpf/issues/290

Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211002161000.3854559-1-hengqi.chen@gmail.com

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index f32fa51b1e63e994a4ef517a7054ff3f4e636b52..4b90878a315f479d6ecf6dd25c879768cf563652 100644 (file)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -6672,7 +6672,7 @@ bpf_object__open_buffer(const void *obj_buf, size_t obj_buf_sz,
        return libbpf_ptr(__bpf_object__open(NULL, obj_buf, obj_buf_sz, &opts));
 }
 
-int bpf_object__unload(struct bpf_object *obj)
+static int bpf_object_unload(struct bpf_object *obj)
 {
        size_t i;
 
@@ -6691,6 +6691,8 @@ int bpf_object__unload(struct bpf_object *obj)
        return 0;
 }
 
+int bpf_object__unload(struct bpf_object *obj) __attribute__((alias("bpf_object_unload")));
+
 static int bpf_object__sanitize_maps(struct bpf_object *obj)
 {
        struct bpf_map *m;
@@ -7089,7 +7091,7 @@ out:
                if (obj->maps[i].pinned && !obj->maps[i].reused)
                        bpf_map__unpin(&obj->maps[i], NULL);
 
-       bpf_object__unload(obj);
+       bpf_object_unload(obj);
        pr_warn("failed to load object '%s'\n", obj->path);
        return libbpf_err(err);
 }
@@ -7698,7 +7700,7 @@ void bpf_object__close(struct bpf_object *obj)
 
        bpf_gen__free(obj->gen_loader);
        bpf_object__elf_finish(obj);
-       bpf_object__unload(obj);
+       bpf_object_unload(obj);
        btf__free(obj->btf);
        btf_ext__free(obj->btf_ext);
 

diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index e35490c54eb3ac7847970d3a070425e9c3abf321..df10d14dbbb887a0f3641fc0400df28d4d6b4940 100644 (file)
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -150,6 +150,7 @@ struct bpf_object_load_attr {
 /* Load/unload object into/from kernel */
 LIBBPF_API int bpf_object__load(struct bpf_object *obj);
 LIBBPF_API int bpf_object__load_xattr(struct bpf_object_load_attr *attr);
+LIBBPF_DEPRECATED_SINCE(0, 6, "bpf_object__unload() is deprecated, use bpf_object__close() instead")
 LIBBPF_API int bpf_object__unload(struct bpf_object *obj);
 
 LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj);