module: Handle 'struct module_version_attribute' as const

The structure is always read-only due to its placement in the read-only
section __modver. Reflect this at its usage sites.
Also prepare for the const handling of 'struct module_attribute' itself.

Signed-off-by: Thomas Weißschuh <[email protected]>
Reviewed-by: Petr Pavlu <[email protected]>
Link: https://lore.kernel.org/r/20241216-sysfs-const-attr-module-v1-2-3790b53e0abf@weissschuh.net
Signed-off-by: Petr Pavlu <[email protected]>

Author: t-8ch

include/linux/module.h

@@ -275,7 +275,7 @@ extern typeof(name) __mod_device_table__##type##__##name		\
 #else
 #define MODULE_VERSION(_version)					\
 	MODULE_INFO(version, _version);					\
-	static struct module_version_attribute __modver_attr		\
+	static const struct module_version_attribute __modver_attr	\
 		__used __section("__modver")				\
 		__aligned(__alignof__(struct module_version_attribute)) \
 		= {							\

kernel/params.c

@@ -860,8 +860,8 @@ static void __init param_sysfs_builtin(void)
 ssize_t __modver_version_show(struct module_attribute *mattr,
 			      struct module_kobject *mk, char *buf)
 {
-	struct module_version_attribute *vattr =
-		container_of(mattr, struct module_version_attribute, mattr);
+	const struct module_version_attribute *vattr =
+		container_of_const(mattr, struct module_version_attribute, mattr);
 
 	return scnprintf(buf, PAGE_SIZE, "%s\n", vattr->version);
 }