On 2024/07/13 4:42, Dan Williams wrote: > @@ -2668,8 +2670,12 @@ static int dev_uevent(const struct kobject *kobj, struct kobj_uevent_env *env) > if (dev->type && dev->type->name) > add_uevent_var(env, "DEVTYPE=%s", dev->type->name); > > - if (dev->driver) > - add_uevent_var(env, "DRIVER=%s", dev->driver->name); > + /* Synchronize with module_remove_driver() */ > + rcu_read_lock(); > + driver = READ_ONCE(dev->driver); > + if (driver) > + add_uevent_var(env, "DRIVER=%s", driver->name); > + rcu_read_unlock(); > Given that read of dev->driver is protected using RCU, > @@ -97,6 +98,9 @@ void module_remove_driver(struct device_driver *drv) > if (!drv) > return; > where is dev->driver = NULL; performed prior to > + /* Synchronize with dev_uevent() */ > + synchronize_rcu(); > + this synchronize_rcu(), in order to make sure that READ_ONCE(dev->driver) in dev_uevent() observes NULL? > sysfs_remove_link(&drv->p->kobj, "module"); > > if (drv->owner) >
