Tadeusz Struk [off-list ref] wrote:

+/**
+ * asymmetric_key_verify_signature - invoke verify signature operation on a key
+ *			             of the asymmetric subtype
+ * @key: key from the system keyring
+ * @sig: signature to verify
+ *
+ * return: 0 on success or errno on failure
+ */
+int asymmetric_key_verify_signature(const struct key *key,
+				    const struct public_key_signature *sig)

This is duplicating what's in signature.c in the same directory.

David