modpost: file2alias: check prototype of handler

BugLink: https://bugs.launchpad.net/bugs/1828420

commit f880eea6 upstream.

Use specific prototype instead of an opaque pointer so that the
compiler can catch function prototype mismatch.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

scripts/mod/file2alias.c

@@ -47,7 +47,7 @@ typedef struct {
 struct devtable {
 	const char *device_id; /* name of table, __mod_<name>__*_device_table. */
 	unsigned long id_size;
-	void *function;
+	int (*do_entry)(const char *filename, void *symval, char *alias);
 };
 
 /* Define a variable f that holds the value of field f of struct devid
@@ -1198,12 +1198,11 @@ static bool sym_is(const char *name, unsigned namelen, const char *symbol)
 static void do_table(void *symval, unsigned long size,
 		     unsigned long id_size,
 		     const char *device_id,
-		     void *function,
+		     int (*do_entry)(const char *filename, void *symval, char *alias),
 		     struct module *mod)
 {
 	unsigned int i;
 	char alias[500];
-	int (*do_entry)(const char *, void *entry, char *alias) = function;
 
 	device_id_check(mod->name, device_id, size, id_size, symval);
 	/* Leave last one: it's the terminator. */
@@ -1314,7 +1313,7 @@ void handle_moddevtable(struct module *mod, struct elf_info *info,
 
 			if (sym_is(name, namelen, p->device_id)) {
 				do_table(symval, sym->st_size, p->id_size,
-					 p->device_id, p->function, mod);
+					 p->device_id, p->do_entry, mod);
 				break;
 			}
 		}