[PATCH] usb: usbatm: Convert timers to use timer_setup()

From: Kees Cook
Date: Tue Oct 24 2017 - 06:09:09 EST


In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly. Additionally corrects and on-stack
timer usage.

Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Duncan Sands <duncan.sands@xxxxxxx>
Cc: Allen Pais <allen.lkml@xxxxxxxxx>
Cc: "Gustavo A. R. Silva" <garsilva@xxxxxxxxxxxxxx>
Cc: accessrunner-general@xxxxxxxxxxxxxxxxxxxxx
Cc: linux-usb@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
drivers/usb/atm/cxacru.c | 23 ++++++++++++++++-------
drivers/usb/atm/speedtch.c | 16 ++++++++--------
drivers/usb/atm/usbatm.c | 10 +++++-----
3 files changed, 29 insertions(+), 20 deletions(-)

diff --git a/drivers/usb/atm/cxacru.c b/drivers/usb/atm/cxacru.c
index 600a670b4feb..53c00d035e31 100644
--- a/drivers/usb/atm/cxacru.c
+++ b/drivers/usb/atm/cxacru.c
@@ -560,21 +560,30 @@ static void cxacru_blocking_completion(struct urb *urb)
complete(urb->context);
}

-static void cxacru_timeout_kill(unsigned long data)
+struct cxacru_timer {
+ struct timer_list timer;
+ struct urb *urb;
+};
+
+static void cxacru_timeout_kill(struct timer_list *t)
{
- usb_unlink_urb((struct urb *) data);
+ struct cxacru_timer *timer = from_timer(timer, t, timer);
+
+ usb_unlink_urb(timer->urb);
}

static int cxacru_start_wait_urb(struct urb *urb, struct completion *done,
int *actual_length)
{
- struct timer_list timer;
+ struct cxacru_timer timer = {
+ .urb = urb,
+ };

- setup_timer(&timer, cxacru_timeout_kill, (unsigned long)urb);
- timer.expires = jiffies + msecs_to_jiffies(CMD_TIMEOUT);
- add_timer(&timer);
+ timer_setup_on_stack(&timer.timer, cxacru_timeout_kill, 0);
+ mod_timer(&timer.timer, jiffies + msecs_to_jiffies(CMD_TIMEOUT));
wait_for_completion(done);
- del_timer_sync(&timer);
+ del_timer_sync(&timer.timer);
+ destroy_timer_on_stack(&timer.timer);

if (actual_length)
*actual_length = urb->actual_length;
diff --git a/drivers/usb/atm/speedtch.c b/drivers/usb/atm/speedtch.c
index 091db9b281f5..b7fb4beed2b8 100644
--- a/drivers/usb/atm/speedtch.c
+++ b/drivers/usb/atm/speedtch.c
@@ -571,9 +571,10 @@ static void speedtch_check_status(struct work_struct *work)
}
}

-static void speedtch_status_poll(unsigned long data)
+static void speedtch_status_poll(struct timer_list *t)
{
- struct speedtch_instance_data *instance = (void *)data;
+ struct speedtch_instance_data *instance =
+ from_timer(instance, t, status_check_timer);

schedule_work(&instance->status_check_work);

@@ -584,9 +585,10 @@ static void speedtch_status_poll(unsigned long data)
atm_warn(instance->usbatm, "Too many failures - disabling line status polling\n");
}

-static void speedtch_resubmit_int(unsigned long data)
+static void speedtch_resubmit_int(struct timer_list *t)
{
- struct speedtch_instance_data *instance = (void *)data;
+ struct speedtch_instance_data *instance = from_timer(instance, t,
+ resubmit_timer);
struct urb *int_urb = instance->int_urb;
int ret;

@@ -874,13 +876,11 @@ static int speedtch_bind(struct usbatm_data *usbatm,
usbatm->flags |= (use_isoc ? UDSL_USE_ISOC : 0);

INIT_WORK(&instance->status_check_work, speedtch_check_status);
- setup_timer(&instance->status_check_timer, speedtch_status_poll,
- (unsigned long)instance);
+ timer_setup(&instance->status_check_timer, speedtch_status_poll, 0);
instance->last_status = 0xff;
instance->poll_delay = MIN_POLL_DELAY;

- setup_timer(&instance->resubmit_timer, speedtch_resubmit_int,
- (unsigned long)instance);
+ timer_setup(&instance->resubmit_timer, speedtch_resubmit_int, 0);

instance->int_urb = usb_alloc_urb(0, GFP_KERNEL);

diff --git a/drivers/usb/atm/usbatm.c b/drivers/usb/atm/usbatm.c
index 8607af758bbd..31a4e4824f23 100644
--- a/drivers/usb/atm/usbatm.c
+++ b/drivers/usb/atm/usbatm.c
@@ -1003,18 +1003,18 @@ static int usbatm_heavy_init(struct usbatm_data *instance)
return 0;
}

-static void usbatm_tasklet_schedule(unsigned long data)
+static void usbatm_tasklet_schedule(struct timer_list *t)
{
- tasklet_schedule((struct tasklet_struct *) data);
+ struct usbatm_channel *channel = from_timer(channel, t, delay);
+
+ tasklet_schedule(&channel->tasklet);
}

static void usbatm_init_channel(struct usbatm_channel *channel)
{
spin_lock_init(&channel->lock);
INIT_LIST_HEAD(&channel->list);
- channel->delay.function = usbatm_tasklet_schedule;
- channel->delay.data = (unsigned long) &channel->tasklet;
- init_timer(&channel->delay);
+ timer_setup(&channel->delay, usbatm_tasklet_schedule, 0);
}

int usbatm_usb_probe(struct usb_interface *intf, const struct usb_device_id *id,
--
2.7.4


--
Kees Cook
Pixel Security