Commit cc271ab8 authored by Tetsuo Handa's avatar Tetsuo Handa Committed by Jakub Kicinski
Browse files

wwan_hwsim: Avoid flush_scheduled_work() usage 

Flushing system-wide workqueues is dangerous and will be forbidden.
Replace system_wq with local wwan_wq.

While we are at it, make err_clean_devs: label of wwan_hwsim_init()
behave like wwan_hwsim_exit(), for it is theoretically possible to call
wwan_hwsim_debugfs_devcreate_write()/wwan_hwsim_debugfs_devdestroy_write()
by the moment wwan_hwsim_init_devs() returns.

Link: https://lkml.kernel.org/r/49925af7-78a8-a3dd-bce6-cfc02e1a9236@I-love.SAKURA.ne.jp


Signed-off-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: default avatarSergey Ryazanov <ryazanov.s.a@gmail.com>
Reviewed-by: default avatarLoic Poulain <loic.poulain@linaro.org>
Link: https://lore.kernel.org/r/7390d51f-60e2-3cee-5277-b819a55ceabe@I-love.SAKURA.ne.jp


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent df1cc211

drivers/net/wwan/wwan_hwsim.c

+17 −5
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ static struct dentry *wwan_hwsim_debugfs_devcreate; 
static DEFINE_SPINLOCK(wwan_hwsim_devs_lock);

static LIST_HEAD(wwan_hwsim_devs);

static unsigned int wwan_hwsim_dev_idx;

static struct workqueue_struct *wwan_wq;



struct wwan_hwsim_dev {

	struct list_head list;
@@ -371,7 +372,7 @@ static ssize_t wwan_hwsim_debugfs_portdestroy_write(struct file *file, 
	 * waiting this callback to finish in the debugfs_remove() call. So,

	 * use workqueue.

	 */

	schedule_work(&port->del_work);

	queue_work(wwan_wq, &port->del_work);



	return count;

}
@@ -416,7 +417,7 @@ static ssize_t wwan_hwsim_debugfs_devdestroy_write(struct file *file, 
	 * waiting this callback to finish in the debugfs_remove() call. So,

	 * use workqueue.

	 */

	schedule_work(&dev->del_work);

	queue_work(wwan_wq, &dev->del_work);



	return count;

}
@@ -506,9 +507,15 @@ static int __init wwan_hwsim_init(void) 
	if (wwan_hwsim_devsnum < 0 || wwan_hwsim_devsnum > 128)

		return -EINVAL;



	wwan_wq = alloc_workqueue("wwan_wq", 0, 0);

	if (!wwan_wq)

		return -ENOMEM;



	wwan_hwsim_class = class_create(THIS_MODULE, "wwan_hwsim");

	if (IS_ERR(wwan_hwsim_class))

		return PTR_ERR(wwan_hwsim_class);

	if (IS_ERR(wwan_hwsim_class)) {

		err = PTR_ERR(wwan_hwsim_class);

		goto err_wq_destroy;

	}



	wwan_hwsim_debugfs_topdir = debugfs_create_dir("wwan_hwsim", NULL);

	wwan_hwsim_debugfs_devcreate =
@@ -523,9 +530,13 @@ static int __init wwan_hwsim_init(void) 
	return 0;



err_clean_devs:

	debugfs_remove(wwan_hwsim_debugfs_devcreate);	/* Avoid new devs */

	wwan_hwsim_free_devs();

	flush_workqueue(wwan_wq);	/* Wait deletion works completion */

	debugfs_remove(wwan_hwsim_debugfs_topdir);

	class_destroy(wwan_hwsim_class);

err_wq_destroy:

	destroy_workqueue(wwan_wq);



	return err;

}
@@ -534,9 +545,10 @@ static void __exit wwan_hwsim_exit(void) 
{

	debugfs_remove(wwan_hwsim_debugfs_devcreate);	/* Avoid new devs */

	wwan_hwsim_free_devs();

	flush_scheduled_work();		/* Wait deletion works completion */

	flush_workqueue(wwan_wq);	/* Wait deletion works completion */

	debugfs_remove(wwan_hwsim_debugfs_topdir);

	class_destroy(wwan_hwsim_class);

	destroy_workqueue(wwan_wq);

}



module_init(wwan_hwsim_init);