Commit eafd52e6 authored by Ivan Orlov's avatar Ivan Orlov Committed by Greg Kroah-Hartman
Browse files

char: misc: make misc_class a static const structure 



Now that the driver core allows for struct class to be in read-only
memory, move the misc_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at load time.

Cc: Arnd Bergmann <arnd@arndb.de>
Suggested-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarIvan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20230620143751.578239-14-gregkh@linuxfoundation.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7671284b

drivers/char/misc.c

+20 −19
Original line number Diff line number Diff line
@@ -168,7 +168,21 @@ static int misc_open(struct inode *inode, struct file *file) 
	return err;

}



static struct class *misc_class;

static char *misc_devnode(const struct device *dev, umode_t *mode)

{

	const struct miscdevice *c = dev_get_drvdata(dev);



	if (mode && c->mode)

		*mode = c->mode;

	if (c->nodename)

		return kstrdup(c->nodename, GFP_KERNEL);

	return NULL;

}



static const struct class misc_class = {

	.name		= "misc",

	.devnode	= misc_devnode,

};



static const struct file_operations misc_fops = {

	.owner		= THIS_MODULE,
@@ -226,7 +240,7 @@ int misc_register(struct miscdevice *misc) 
	dev = MKDEV(MISC_MAJOR, misc->minor);



	misc->this_device =

		device_create_with_groups(misc_class, misc->parent, dev,

		device_create_with_groups(&misc_class, misc->parent, dev,

					  misc, misc->groups, "%s", misc->name);

	if (IS_ERR(misc->this_device)) {

		if (is_dynamic) {
@@ -263,43 +277,30 @@ void misc_deregister(struct miscdevice *misc) 


	mutex_lock(&misc_mtx);

	list_del(&misc->list);

	device_destroy(misc_class, MKDEV(MISC_MAJOR, misc->minor));

	device_destroy(&misc_class, MKDEV(MISC_MAJOR, misc->minor));

	misc_minor_free(misc->minor);

	mutex_unlock(&misc_mtx);

}

EXPORT_SYMBOL(misc_deregister);



static char *misc_devnode(const struct device *dev, umode_t *mode)

{

	const struct miscdevice *c = dev_get_drvdata(dev);



	if (mode && c->mode)

		*mode = c->mode;

	if (c->nodename)

		return kstrdup(c->nodename, GFP_KERNEL);

	return NULL;

}



static int __init misc_init(void)

{

	int err;

	struct proc_dir_entry *ret;



	ret = proc_create_seq("misc", 0, NULL, &misc_seq_ops);

	misc_class = class_create("misc");

	err = PTR_ERR(misc_class);

	if (IS_ERR(misc_class))

	err = class_register(&misc_class);

	if (err)

		goto fail_remove;



	err = -EIO;

	if (register_chrdev(MISC_MAJOR, "misc", &misc_fops))

		goto fail_printk;

	misc_class->devnode = misc_devnode;

	return 0;



fail_printk:

	pr_err("unable to get major %d for misc devices\n", MISC_MAJOR);

	class_destroy(misc_class);

	class_unregister(&misc_class);

fail_remove:

	if (ret)

		remove_proc_entry("misc", NULL);