bpf: Move __kfunc_param_match_suffix() to btf.c.

Move __kfunc_param_match_suffix() to btf.c and rename it as
btf_param_match_suffix(). It can be reused by bpf_struct_ops later.

Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240209023750.1153905-3-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

3 files changed, 32 insertions, 28 deletions

diff --git a/include/linux/btf.h b/include/linux/btf.h
index 1ee8977b8c95..df76a14c64f6 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h
@@ -495,6 +495,10 @@ static inline void *btf_id_set8_contains(const struct btf_id_set8 *set, u32 id)
 	return bsearch(&id, set->pairs, set->cnt, sizeof(set->pairs[0]), btf_id_cmp_func);
 }
 
+bool btf_param_match_suffix(const struct btf *btf,
+			    const struct btf_param *arg,
+			    const char *suffix);
+
 struct bpf_verifier_log;
 
 #if defined(CONFIG_BPF_JIT) && defined(CONFIG_BPF_SYSCALL)
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index cf100b5573ca..447da964f217 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -8904,3 +8904,21 @@ errout:
 }
 EXPORT_SYMBOL_GPL(__register_bpf_struct_ops);
 #endif
+
+bool btf_param_match_suffix(const struct btf *btf,
+			    const struct btf_param *arg,
+			    const char *suffix)
+{
+	int suffix_len = strlen(suffix), len;
+	const char *param_name;
+
+	/* In the future, this can be ported to use BTF tagging */
+	param_name = btf_name_by_offset(btf, arg->name_off);
+	if (str_is_empty(param_name))
+		return false;
+	len = strlen(param_name);
+	if (len <= suffix_len)
+		return false;
+	param_name += len - suffix_len;
+	return !strncmp(param_name, suffix, suffix_len);
+}
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index ddaf09db1175..c92d6af7d975 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -10682,24 +10682,6 @@ static bool is_kfunc_rcu_protected(struct bpf_kfunc_call_arg_meta *meta)
 	return meta->kfunc_flags & KF_RCU_PROTECTED;
 }
 
-static bool __kfunc_param_match_suffix(const struct btf *btf,
-				       const struct btf_param *arg,
-				       const char *suffix)
-{
-	int suffix_len = strlen(suffix), len;
-	const char *param_name;
-
-	/* In the future, this can be ported to use BTF tagging */
-	param_name = btf_name_by_offset(btf, arg->name_off);
-	if (str_is_empty(param_name))
-		return false;
-	len = strlen(param_name);
-	if (len < suffix_len)
-		return false;
-	param_name += len - suffix_len;
-	return !strncmp(param_name, suffix, suffix_len);
-}
-
 static bool is_kfunc_arg_mem_size(const struct btf *btf,
 				  const struct btf_param *arg,
 				  const struct bpf_reg_state *reg)
@@ -10710,7 +10692,7 @@ static bool is_kfunc_arg_mem_size(const struct btf *btf,
 	if (!btf_type_is_scalar(t) || reg->type != SCALAR_VALUE)
 		return false;
 
-	return __kfunc_param_match_suffix(btf, arg, "__sz");
+	return btf_param_match_suffix(btf, arg, "__sz");
 }
 
 static bool is_kfunc_arg_const_mem_size(const struct btf *btf,
@@ -10723,47 +10705,47 @@ static bool is_kfunc_arg_const_mem_size(const struct btf *btf,
 	if (!btf_type_is_scalar(t) || reg->type != SCALAR_VALUE)
 		return false;
 
-	return __kfunc_param_match_suffix(btf, arg, "__szk");
+	return btf_param_match_suffix(btf, arg, "__szk");
 }
 
 static bool is_kfunc_arg_optional(const struct btf *btf, const struct btf_param *arg)
 {
-	return __kfunc_param_match_suffix(btf, arg, "__opt");
+	return btf_param_match_suffix(btf, arg, "__opt");
 }
 
 static bool is_kfunc_arg_constant(const struct btf *btf, const struct btf_param *arg)
 {
-	return __kfunc_param_match_suffix(btf, arg, "__k");
+	return btf_param_match_suffix(btf, arg, "__k");
 }
 
 static bool is_kfunc_arg_ignore(const struct btf *btf, const struct btf_param *arg)
 {
-	return __kfunc_param_match_suffix(btf, arg, "__ign");
+	return btf_param_match_suffix(btf, arg, "__ign");
 }
 
 static bool is_kfunc_arg_alloc_obj(const struct btf *btf, const struct btf_param *arg)
 {
-	return __kfunc_param_match_suffix(btf, arg, "__alloc");
+	return btf_param_match_suffix(btf, arg, "__alloc");
 }
 
 static bool is_kfunc_arg_uninit(const struct btf *btf, const struct btf_param *arg)
 {
-	return __kfunc_param_match_suffix(btf, arg, "__uninit");
+	return btf_param_match_suffix(btf, arg, "__uninit");
 }
 
 static bool is_kfunc_arg_refcounted_kptr(const struct btf *btf, const struct btf_param *arg)
 {
-	return __kfunc_param_match_suffix(btf, arg, "__refcounted_kptr");
+	return btf_param_match_suffix(btf, arg, "__refcounted_kptr");
 }
 
 static bool is_kfunc_arg_nullable(const struct btf *btf, const struct btf_param *arg)
 {
-	return __kfunc_param_match_suffix(btf, arg, "__nullable");
+	return btf_param_match_suffix(btf, arg, "__nullable");
 }
 
 static bool is_kfunc_arg_const_str(const struct btf *btf, const struct btf_param *arg)
 {
-	return __kfunc_param_match_suffix(btf, arg, "__str");
+	return btf_param_match_suffix(btf, arg, "__str");
 }
 
 static bool is_kfunc_arg_scalar_with_name(const struct btf *btf,