[PATCH] net/irda-usb: Convert timers to use timer_setup()

From: Kees Cook
Date: Wed Oct 04 2017 - 20:50:11 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. This requires adding a pointer to
hold the timer's target URB, as there won't be a way to pass this in the
future.

Cc: Samuel Ortiz <samuel@xxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
This requires commit 686fef928bba ("timer: Prepare to change timer
callback argument type") in v4.14-rc3, but should be otherwise
stand-alone.
---
drivers/staging/irda/drivers/irda-usb.c | 20 ++++++--------------
drivers/staging/irda/drivers/irda-usb.h | 1 +
2 files changed, 7 insertions(+), 14 deletions(-)

diff --git a/drivers/staging/irda/drivers/irda-usb.c b/drivers/staging/irda/drivers/irda-usb.c
index 723e49bc4baa..901862ec1ed0 100644
--- a/drivers/staging/irda/drivers/irda-usb.c
+++ b/drivers/staging/irda/drivers/irda-usb.c
@@ -117,7 +117,7 @@ static void irda_usb_close(struct irda_usb_cb *self);
static void speed_bulk_callback(struct urb *urb);
static void write_bulk_callback(struct urb *urb);
static void irda_usb_receive(struct urb *urb);
-static void irda_usb_rx_defer_expired(unsigned long data);
+static void irda_usb_rx_defer_expired(struct timer_list *t);
static int irda_usb_net_open(struct net_device *dev);
static int irda_usb_net_close(struct net_device *dev);
static int irda_usb_net_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
@@ -846,8 +846,7 @@ static void irda_usb_receive(struct urb *urb)
* hot unplug of the dongle...
* Lowest effective timer is 10ms...
* Jean II */
- self->rx_defer_timer.function = irda_usb_rx_defer_expired;
- self->rx_defer_timer.data = (unsigned long) urb;
+ self->rx_defer_timer_urb = urb;
mod_timer(&self->rx_defer_timer,
jiffies + msecs_to_jiffies(10));

@@ -953,20 +952,13 @@ static void irda_usb_receive(struct urb *urb)
* In case of errors, we want the USB layer to have time to recover.
* Now, it is time to resubmit ouur Rx URB...
*/
-static void irda_usb_rx_defer_expired(unsigned long data)
+static void irda_usb_rx_defer_expired(struct timer_list *t)
{
- struct urb *urb = (struct urb *) data;
+ struct irda_usb_cb *self = from_timer(self, t, rx_defer_timer);
+ struct urb *urb = self->rx_defer_timer_urb;
struct sk_buff *skb = (struct sk_buff *) urb->context;
- struct irda_usb_cb *self;
- struct irda_skb_cb *cb;
struct urb *next_urb;

- /* Find ourselves */
- cb = (struct irda_skb_cb *) skb->cb;
- IRDA_ASSERT(cb != NULL, return;);
- self = (struct irda_usb_cb *) cb->context;
- IRDA_ASSERT(self != NULL, return;);
-
/* Same stuff as when Rx is done, see above... */
next_urb = self->idle_rx_urb;
urb->context = NULL;
@@ -1622,7 +1614,7 @@ static int irda_usb_probe(struct usb_interface *intf,
self = netdev_priv(net);
self->netdev = net;
spin_lock_init(&self->lock);
- init_timer(&self->rx_defer_timer);
+ timer_setup(&self->rx_defer_timer, irda_usb_rx_defer_expired, 0);

self->capability = id->driver_info;
self->needspatch = ((self->capability & IUC_STIR421X) != 0);
diff --git a/drivers/staging/irda/drivers/irda-usb.h b/drivers/staging/irda/drivers/irda-usb.h
index 8ac389fa9348..56ee8c16c5e2 100644
--- a/drivers/staging/irda/drivers/irda-usb.h
+++ b/drivers/staging/irda/drivers/irda-usb.h
@@ -170,5 +170,6 @@ struct irda_usb_cb {
int needspatch; /* device needs firmware patch */

struct timer_list rx_defer_timer; /* Wait for Rx error to clear */
+ struct urb *rx_defer_timer_urb; /* URB attached to rx_defer_timer */
};

--
2.7.4


--
Kees Cook
Pixel Security