modpost: move strstarts() to modpost.h

This macro is useful in file2alias.c as well.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Author: masahir0y

scripts/mod/file2alias.c

@@ -1515,7 +1515,7 @@ void handle_moddevtable(struct module *mod, struct elf_info *info,
 		return;
 
 	/* All our symbols are of form __mod_<name>__<identifier>_device_table. */
-	if (strncmp(symname, "__mod_", strlen("__mod_")))
+	if (!strstarts(symname, "__mod_"))
 		return;
 	name = symname + strlen("__mod_");
 	namelen = strlen(name);

scripts/mod/modpost.c

@@ -341,8 +341,6 @@ static const char *sec_name(const struct elf_info *info, unsigned int secindex)
 	return sech_name(info, &info->sechdrs[secindex]);
 }
 
-#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
-
 static struct symbol *sym_add_exported(const char *name, struct module *mod,
 				       bool gpl_only, const char *namespace)
 {

scripts/mod/modpost.h

@@ -67,6 +67,8 @@
 
 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
 
+#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
+
 struct buffer {
 	char *p;
 	int pos;