[PATCH bpf-next v4 1/3] bpf: export necessary symbols for modules with struct_ops

["D. Wythe" <alibuda@linux.alibaba.com>]

Exports three necessary symbols for implementing struct_ops with
tristate subsystem.

To hold or release refcnt of struct_ops refcnt by inline funcs
bpf_try_module_get and bpf_module_put which use bpf_struct_ops_get(put)
conditionally.

And to copy obj name from one to the other with effective checks by
bpf_obj_name_cpy.

Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
---
 kernel/bpf/bpf_struct_ops.c | 2 ++
 kernel/bpf/syscall.c        | 1 +
 2 files changed, 3 insertions(+)

diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c
index a41e6730edcf..278490683d28 100644
--- a/kernel/bpf/bpf_struct_ops.c
+++ b/kernel/bpf/bpf_struct_ops.c
@@ -1162,6 +1162,7 @@ bool bpf_struct_ops_get(const void *kdata)
 	map = __bpf_map_inc_not_zero(&st_map->map, false);
 	return !IS_ERR(map);
 }
+EXPORT_SYMBOL_GPL(bpf_struct_ops_get);
 
 void bpf_struct_ops_put(const void *kdata)
 {
@@ -1173,6 +1174,7 @@ void bpf_struct_ops_put(const void *kdata)
 
 	bpf_map_put(&st_map->map);
 }
+EXPORT_SYMBOL_GPL(bpf_struct_ops_put);
 
 u32 bpf_struct_ops_id(const void *kdata)
 {
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 8a129746bd6c..80b86e9d3c39 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1234,6 +1234,7 @@ int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
 
 	return src - orig_src;
 }
+EXPORT_SYMBOL_GPL(bpf_obj_name_cpy);
 
 int map_check_no_btf(const struct bpf_map *map,
 		     const struct btf *btf,
-- 
2.45.0