From cc271ab86606c963e97915d84be34ae4bd067578 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Fri, 22 Apr 2022 12:01:24 +0900 Subject: 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: Tetsuo Handa Reviewed-by: Sergey Ryazanov Reviewed-by: Loic Poulain Link: https://lore.kernel.org/r/7390d51f-60e2-3cee-5277-b819a55ceabe@I-love.SAKURA.ne.jp Signed-off-by: Jakub Kicinski --- drivers/net/wwan/wwan_hwsim.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/drivers/net/wwan/wwan_hwsim.c b/drivers/net/wwan/wwan_hwsim.c index 5b62cf3b3c42..fad642f9ffd8 100644 --- a/drivers/net/wwan/wwan_hwsim.c +++ b/drivers/net/wwan/wwan_hwsim.c @@ -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); -- cgit v1.2.3