bpf: Fix non-static bpf_func_proto struct definitions

This patch does two things:

1) Marks the dynptr bpf_func_proto structs that were added in [1]
   as static, as pointed out by the kernel test robot in [2].

2) There are some bpf_func_proto structs marked as extern which can
   instead be statically defined.

  [1] https://lore.kernel.org/bpf/20220523210712.3641569-1-joannelkoong@gmail.com/
  [2] https://lore.kernel.org/bpf/62ab89f2.Pko7sI08RAKdF8R6%25lkp@intel.com/Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220616225407.1878436-1-joannelkoong@gmail.com

include/linux/bpf.h

@@ -2363,12 +2363,9 @@ extern const struct bpf_func_proto bpf_for_each_map_elem_proto;
 extern const struct bpf_func_proto bpf_btf_find_by_name_kind_proto;
 extern const struct bpf_func_proto bpf_sk_setsockopt_proto;
 extern const struct bpf_func_proto bpf_sk_getsockopt_proto;
-extern const struct bpf_func_proto bpf_kallsyms_lookup_name_proto;
 extern const struct bpf_func_proto bpf_find_vma_proto;
 extern const struct bpf_func_proto bpf_loop_proto;
-extern const struct bpf_func_proto bpf_strncmp_proto;
 extern const struct bpf_func_proto bpf_copy_from_user_task_proto;
-extern const struct bpf_func_proto bpf_kptr_xchg_proto;
 
 const struct bpf_func_proto *tracing_prog_func_proto(
   enum bpf_func_id func_id, const struct bpf_prog *prog);

kernel/bpf/helpers.c

@@ -584,7 +584,7 @@ BPF_CALL_3(bpf_strncmp, const char *, s1, u32, s1_sz, const char *, s2)
 	return strncmp(s1, s2, s1_sz);
 }
 
-const struct bpf_func_proto bpf_strncmp_proto = {
+static const struct bpf_func_proto bpf_strncmp_proto = {
 	.func		= bpf_strncmp,
 	.gpl_only	= false,
 	.ret_type	= RET_INTEGER,
@@ -1402,7 +1402,7 @@ BPF_CALL_2(bpf_kptr_xchg, void *, map_value, void *, ptr)
  */
 #define BPF_PTR_POISON ((void *)((0xeB9FUL << 2) + POISON_POINTER_DELTA))
 
-const struct bpf_func_proto bpf_kptr_xchg_proto = {
+static const struct bpf_func_proto bpf_kptr_xchg_proto = {
 	.func         = bpf_kptr_xchg,
 	.gpl_only     = false,
 	.ret_type     = RET_PTR_TO_BTF_ID_OR_NULL,
@@ -1487,7 +1487,7 @@ BPF_CALL_4(bpf_dynptr_from_mem, void *, data, u32, size, u64, flags, struct bpf_
 	return err;
 }
 
-const struct bpf_func_proto bpf_dynptr_from_mem_proto = {
+static const struct bpf_func_proto bpf_dynptr_from_mem_proto = {
 	.func		= bpf_dynptr_from_mem,
 	.gpl_only	= false,
 	.ret_type	= RET_INTEGER,
@@ -1513,7 +1513,7 @@ BPF_CALL_4(bpf_dynptr_read, void *, dst, u32, len, struct bpf_dynptr_kern *, src
 	return 0;
 }
 
-const struct bpf_func_proto bpf_dynptr_read_proto = {
+static const struct bpf_func_proto bpf_dynptr_read_proto = {
 	.func		= bpf_dynptr_read,
 	.gpl_only	= false,
 	.ret_type	= RET_INTEGER,
@@ -1539,7 +1539,7 @@ BPF_CALL_4(bpf_dynptr_write, struct bpf_dynptr_kern *, dst, u32, offset, void *,
 	return 0;
 }
 
-const struct bpf_func_proto bpf_dynptr_write_proto = {
+static const struct bpf_func_proto bpf_dynptr_write_proto = {
 	.func		= bpf_dynptr_write,
 	.gpl_only	= false,
 	.ret_type	= RET_INTEGER,
@@ -1566,7 +1566,7 @@ BPF_CALL_3(bpf_dynptr_data, struct bpf_dynptr_kern *, ptr, u32, offset, u32, len
 	return (unsigned long)(ptr->data + ptr->offset + offset);
 }
 
-const struct bpf_func_proto bpf_dynptr_data_proto = {
+static const struct bpf_func_proto bpf_dynptr_data_proto = {
 	.func		= bpf_dynptr_data,
 	.gpl_only	= false,
 	.ret_type	= RET_PTR_TO_DYNPTR_MEM_OR_NULL,

kernel/bpf/syscall.c

@@ -5131,7 +5131,7 @@ BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flag
 	return *res ? 0 : -ENOENT;
 }
 
-const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
+static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
 	.func		= bpf_kallsyms_lookup_name,
 	.gpl_only	= false,
 	.ret_type	= RET_INTEGER,