From: Kui-Feng Lee <redacted>

Replace the static list of struct_ops types with per-btf struct_ops_tab to
enable dynamic registration.

Both bpf_dummy_ops and bpf_tcp_ca now utilize the registration function
instead of being listed in bpf_struct_ops_types.h.

Cc: netdev@vger.kernel.org
Signed-off-by: Kui-Feng Lee <redacted>
---
  include/linux/bpf.h               |  36 ++++++--
  include/linux/btf.h               |   5 +-
  kernel/bpf/bpf_struct_ops.c       | 140 +++++++++---------------------
  kernel/bpf/bpf_struct_ops_types.h |  12 ---
  kernel/bpf/btf.c                  |  41 ++++++++-
  net/bpf/bpf_dummy_struct_ops.c    |  14 ++-
  net/ipv4/bpf_tcp_ca.c             |  16 +++-
  7 files changed, 140 insertions(+), 124 deletions(-)
  delete mode 100644 kernel/bpf/bpf_struct_ops_types.h

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index c993df3cf699..9d7105ff06db 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h

@@ -1644,7 +1644,6 @@ struct bpf_struct_ops_desc {
  #if defined(CONFIG_BPF_JIT) && defined(CONFIG_BPF_SYSCALL)
  #define BPF_MODULE_OWNER ((void *)((0xeB9FUL << 2) + POISON_POINTER_DELTA))
  const struct bpf_struct_ops_desc *bpf_struct_ops_find(struct btf *btf, u32 type_id);
-void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log);
  bool bpf_struct_ops_get(const void *kdata);
  void bpf_struct_ops_put(const void *kdata);
  int bpf_struct_ops_map_sys_lookup_elem(struct bpf_map *map, void *key,

@@ -1690,10 +1689,6 @@ static inline const struct bpf_struct_ops_desc *bpf_struct_ops_find(struct btf *
  {
  	return NULL;
  }
-static inline void bpf_struct_ops_init(struct btf *btf,
-				       struct bpf_verifier_log *log)
-{
-}
  static inline bool bpf_try_module_get(const void *data, struct module *owner)
  {
  	return try_module_get(owner);

@@ -3232,4 +3227,35 @@ static inline bool bpf_is_subprog(const struct bpf_prog *prog)
  	return prog->aux->func_idx != 0;
  }
  
+int register_bpf_struct_ops(struct bpf_struct_ops *st_ops);
+
+enum bpf_struct_ops_state {
+	BPF_STRUCT_OPS_STATE_INIT,
+	BPF_STRUCT_OPS_STATE_INUSE,
+	BPF_STRUCT_OPS_STATE_TOBEFREE,
+	BPF_STRUCT_OPS_STATE_READY,
+};
+
+struct bpf_struct_ops_common_value {
+	refcount_t refcnt;
+	enum bpf_struct_ops_state state;
+};
+
+/* bpf_struct_ops_##_name (e.g. bpf_struct_ops_tcp_congestion_ops) is
+ * the map's value exposed to the userspace and its btf-type-id is
+ * stored at the map->btf_vmlinux_value_type_id.
+ *
+ */
+#define DEFINE_STRUCT_OPS_VALUE_TYPE(_name)			\
+extern struct bpf_struct_ops bpf_##_name;			\
+								\
+struct bpf_struct_ops_##_name {					\
+	struct bpf_struct_ops_common_value common;		\
+	struct _name data ____cacheline_aligned_in_smp;		\
+}
+
+extern int bpf_struct_ops_init(struct bpf_struct_ops_desc *st_ops_desc,
+			       struct btf *btf,
+			       struct bpf_verifier_log *log);
+
  #endif /* _LINUX_BPF_H */

diff --git a/include/linux/btf.h b/include/linux/btf.h
index a8813605f2f6..954536431e0b 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h

@@ -12,6 +12,8 @@
  #include <uapi/linux/bpf.h>
  
  #define BTF_TYPE_EMIT(type) ((void)(type *)0)
+#define BTF_STRUCT_OPS_TYPE_EMIT(type) {((void)(struct type *)0);	\

+		((void)(struct bpf_struct_ops_##type *)0); }
  #define BTF_TYPE_EMIT_ENUM(enum_val) ((void)enum_val)
  
  /* These need to be macros, as the expressions are used in assembler input */

@@ -201,6 +203,7 @@ u32 btf_obj_id(const struct btf *btf);
  bool btf_is_kernel(const struct btf *btf);
  bool btf_is_module(const struct btf *btf);
  struct module *btf_try_get_module(const struct btf *btf);
+struct btf *btf_get_module_btf(const struct module *module);
  u32 btf_nr_types(const struct btf *btf);
  bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
  			   const struct btf_member *m,

@@ -575,8 +578,6 @@ static inline bool btf_type_is_struct_ptr(struct btf *btf, const struct btf_type
  struct bpf_struct_ops;
  struct bpf_struct_ops_desc;
  
-struct bpf_struct_ops_desc *
-btf_add_struct_ops(struct btf *btf, struct bpf_struct_ops *st_ops);
  const struct bpf_struct_ops_desc *
  btf_get_struct_ops(struct btf *btf, u32 *ret_cnt);
  

diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c
index db2bbba50e38..f3ec72be9c63 100644
--- a/kernel/bpf/bpf_struct_ops.c
+++ b/kernel/bpf/bpf_struct_ops.c

@@ -13,21 +13,8 @@
  #include <linux/btf_ids.h>
  #include <linux/rcupdate_wait.h>
  
-enum bpf_struct_ops_state {
-	BPF_STRUCT_OPS_STATE_INIT,
-	BPF_STRUCT_OPS_STATE_INUSE,
-	BPF_STRUCT_OPS_STATE_TOBEFREE,
-	BPF_STRUCT_OPS_STATE_READY,
-};
-
-struct bpf_struct_ops_common_value {
-	refcount_t refcnt;
-	enum bpf_struct_ops_state state;
-};
-#define BPF_STRUCT_OPS_COMMON_VALUE struct bpf_struct_ops_common_value common
-
  struct bpf_struct_ops_value {
-	BPF_STRUCT_OPS_COMMON_VALUE;
+	struct bpf_struct_ops_common_value common;

  	char data[] ____cacheline_aligned_in_smp;
  };
  

@@ -72,35 +59,6 @@ static DEFINE_MUTEX(update_mutex);
  #define VALUE_PREFIX "bpf_struct_ops_"
  #define VALUE_PREFIX_LEN (sizeof(VALUE_PREFIX) - 1)
  
-/* bpf_struct_ops_##_name (e.g. bpf_struct_ops_tcp_congestion_ops) is
- * the map's value exposed to the userspace and its btf-type-id is
- * stored at the map->btf_vmlinux_value_type_id.
- *
- */
-#define BPF_STRUCT_OPS_TYPE(_name)				\
-extern struct bpf_struct_ops bpf_##_name;			\
-								\
-struct bpf_struct_ops_##_name {						\
-	BPF_STRUCT_OPS_COMMON_VALUE;				\
-	struct _name data ____cacheline_aligned_in_smp;		\
-};
-#include "bpf_struct_ops_types.h"
-#undef BPF_STRUCT_OPS_TYPE
-
-enum {
-#define BPF_STRUCT_OPS_TYPE(_name) BPF_STRUCT_OPS_TYPE_##_name,
-#include "bpf_struct_ops_types.h"
-#undef BPF_STRUCT_OPS_TYPE
-	__NR_BPF_STRUCT_OPS_TYPE,
-};
-
-static struct bpf_struct_ops_desc bpf_struct_ops[] = {
-#define BPF_STRUCT_OPS_TYPE(_name)				\
-	[BPF_STRUCT_OPS_TYPE_##_name] = { .st_ops = &bpf_##_name },
-#include "bpf_struct_ops_types.h"
-#undef BPF_STRUCT_OPS_TYPE
-};
-
  const struct bpf_verifier_ops bpf_struct_ops_verifier_ops = {
  };
  

@@ -110,13 +68,22 @@ const struct bpf_prog_ops bpf_struct_ops_prog_ops = {
  #endif
  };
  
-static const struct btf_type *module_type;
-static const struct btf_type *common_value_type;
+BTF_ID_LIST(st_ops_ids)
+BTF_ID(struct, module)
+BTF_ID(struct, bpf_struct_ops_common_value)