Commit a390d1f3 authored by Marcin Slusarz's avatar Marcin Slusarz Committed by David S. Miller

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: default avatarMarcin Slusarz <marcin.slusarz@gmail.com>
Acked-by: default avatarJean Delvare <khali@linux-fr.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 34cd347c
......@@ -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);
}
......@@ -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;
......
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