module: Don't fail module loading when setting ro_after_init section RO failed

Once module init has succeded it is too late to cancel loading.
If setting ro_after_init data section to read-only fails, all we
can do is to inform the user through a warning.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Closes: https://lore.kernel.org/all/20230915082126.4187913-1-ruanjinjie@huawei.com/
Fixes: d1909c0221 ("module: Don't ignore errors from set_memory_XX()")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/d6c81f38da76092de8aacc8c93c4c65cb0fe48b8.1733427536.git.christophe.leroy@csgroup.eu
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>

kernel/module/main.c

@@ -2955,7 +2955,10 @@ static noinline int do_init_module(struct module *mod)
 #endif
 	ret = module_enable_rodata_ro_after_init(mod);
 	if (ret)
-		goto fail_mutex_unlock;
+		pr_warn("%s: module_enable_rodata_ro_after_init() returned %d, "
+			"ro_after_init data might still be writable\n",
+			mod->name, ret);
+
 	mod_tree_remove_init(mod);
 	module_arch_freeing_init(mod);
 	for_class_mod_mem_type(type, init) {
@@ -2994,8 +2997,6 @@ static noinline int do_init_module(struct module *mod)
 
 	return 0;
 
-fail_mutex_unlock:
-	mutex_unlock(&module_mutex);
 fail_free_freeinit:
 	kfree(freeinit);
 fail: