From a390d1f379cf821248b735f43d2e1147ebb8241d Mon Sep 17 00:00:00 2001 From: Marcin Slusarz Date: Fri, 13 Mar 2009 15:41:19 -0700 Subject: [PATCH] phylib: convert state_queue work to delayed_work It closes a race in phy_stop_machine when reprogramming of phy_timer (from phy_state_machine) happens between del_timer_sync and cancel_work_sync. Without this change it could lead to crash if phy_device would be freed after phy_stop_machine (timer would fire and schedule freed work). Signed-off-by: Marcin Slusarz Acked-by: Jean Delvare Signed-off-by: David S. Miller --- drivers/net/phy/phy.c | 41 +++++++++++------------------------------ include/linux/phy.h | 3 +-- 2 files changed, 12 insertions(+), 32 deletions(-) diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index e4ede6080c9d..58b73b08dde0 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -414,7 +414,6 @@ EXPORT_SYMBOL(phy_start_aneg); static void phy_change(struct work_struct *work); static void phy_state_machine(struct work_struct *work); -static void phy_timer(unsigned long data); /** * phy_start_machine - start PHY state machine tracking @@ -434,11 +433,8 @@ void phy_start_machine(struct phy_device *phydev, { phydev->adjust_state = handler; - INIT_WORK(&phydev->state_queue, phy_state_machine); - init_timer(&phydev->phy_timer); - phydev->phy_timer.function = &phy_timer; - phydev->phy_timer.data = (unsigned long) phydev; - mod_timer(&phydev->phy_timer, jiffies + HZ); + INIT_DELAYED_WORK(&phydev->state_queue, phy_state_machine); + schedule_delayed_work(&phydev->state_queue, jiffies + HZ); } /** @@ -451,8 +447,7 @@ void phy_start_machine(struct phy_device *phydev, */ void phy_stop_machine(struct phy_device *phydev) { - del_timer_sync(&phydev->phy_timer); - cancel_work_sync(&phydev->state_queue); + cancel_delayed_work_sync(&phydev->state_queue); mutex_lock(&phydev->lock); if (phydev->state > PHY_UP) @@ -680,11 +675,9 @@ static void phy_change(struct work_struct *work) if (err) goto irq_enable_err; - /* Stop timer and run the state queue now. The work function for - * state_queue will start the timer up again. - */ - del_timer(&phydev->phy_timer); - schedule_work(&phydev->state_queue); + /* reschedule state queue work to run as soon as possible */ + cancel_delayed_work_sync(&phydev->state_queue); + schedule_delayed_work(&phydev->state_queue, 0); return; @@ -761,14 +754,13 @@ EXPORT_SYMBOL(phy_start); /** * phy_state_machine - Handle the state machine * @work: work_struct that describes the work to be done - * - * Description: Scheduled by the state_queue workqueue each time - * phy_timer is triggered. */ static void phy_state_machine(struct work_struct *work) { + struct delayed_work *dwork = + container_of(work, struct delayed_work, work); struct phy_device *phydev = - container_of(work, struct phy_device, state_queue); + container_of(dwork, struct phy_device, state_queue); int needs_aneg = 0; int err = 0; @@ -946,17 +938,6 @@ static void phy_state_machine(struct work_struct *work) if (err < 0) phy_error(phydev); - mod_timer(&phydev->phy_timer, jiffies + PHY_STATE_TIME * HZ); -} - -/* PHY timer which schedules the state machine work */ -static void phy_timer(unsigned long data) -{ - struct phy_device *phydev = (struct phy_device *)data; - - /* - * PHY I/O operations can potentially sleep so we ensure that - * it's done from a process context - */ - schedule_work(&phydev->state_queue); + schedule_delayed_work(&phydev->state_queue, + jiffies + PHY_STATE_TIME * HZ); } diff --git a/include/linux/phy.h b/include/linux/phy.h index d7e54d98869f..32cf14a4b034 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -315,8 +315,7 @@ struct phy_device { /* Interrupt and Polling infrastructure */ struct work_struct phy_queue; - struct work_struct state_queue; - struct timer_list phy_timer; + struct delayed_work state_queue; atomic_t irq_disable; struct mutex lock; -- 2.20.1