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

[Allen]

> 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>

Reviewed-by: Allen Pais <allen.lkml@xxxxxxxxx>

> ---
>  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



-- 
       - Allen