[PATCH] media: input: Convert timers to use timer_setup()

From: Kees Cook
Date: Mon Oct 16 2017 - 19:14:53 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.

One input_dev user hijacks the input_dev software autorepeat timer to
perform its own repeat management. However, there is no path back to the
existing status variable, so add a generic one to the input structure and
use that instead.

Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
Cc: Hans Verkuil <hans.verkuil@xxxxxxxxx>
Cc: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Cc: Geliang Tang <geliangtang@xxxxxxxxx>
Cc: linux-input@xxxxxxxxxxxxxxx
Cc: linux-media@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Acked-by: Pali Rohár <pali.rohar@xxxxxxxxx>
---
drivers/input/input.c | 12 ++++++------
drivers/media/pci/ttpci/av7110.h | 1 -
drivers/media/pci/ttpci/av7110_ir.c | 16 ++++++++--------
include/linux/input.h | 2 ++
4 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/drivers/input/input.c b/drivers/input/input.c
index d268fdc23c64..497ad2dcb699 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -76,7 +76,7 @@ static void input_start_autorepeat(struct input_dev *dev, int code)
{
if (test_bit(EV_REP, dev->evbit) &&
dev->rep[REP_PERIOD] && dev->rep[REP_DELAY] &&
- dev->timer.data) {
+ dev->timer.function) {
dev->repeat_key = code;
mod_timer(&dev->timer,
jiffies + msecs_to_jiffies(dev->rep[REP_DELAY]));
@@ -179,9 +179,9 @@ static void input_pass_event(struct input_dev *dev,
* dev->event_lock here to avoid racing with input_event
* which may cause keys get "stuck".
*/
-static void input_repeat_key(unsigned long data)
+static void input_repeat_key(struct timer_list *t)
{
- struct input_dev *dev = (void *) data;
+ struct input_dev *dev = from_timer(dev, t, timer);
unsigned long flags;

spin_lock_irqsave(&dev->event_lock, flags);
@@ -1790,7 +1790,7 @@ struct input_dev *input_allocate_device(void)
device_initialize(&dev->dev);
mutex_init(&dev->mutex);
spin_lock_init(&dev->event_lock);
- init_timer(&dev->timer);
+ timer_setup(&dev->timer, NULL, 0);
INIT_LIST_HEAD(&dev->h_list);
INIT_LIST_HEAD(&dev->node);

@@ -2053,8 +2053,8 @@ static void devm_input_device_unregister(struct device *dev, void *res)
*/
void input_enable_softrepeat(struct input_dev *dev, int delay, int period)
{
- dev->timer.data = (unsigned long) dev;
- dev->timer.function = input_repeat_key;
+ dev->timer.function = (TIMER_FUNC_TYPE)input_repeat_key;
+ dev->timer_data = 0;
dev->rep[REP_DELAY] = delay;
dev->rep[REP_PERIOD] = period;
}
diff --git a/drivers/media/pci/ttpci/av7110.h b/drivers/media/pci/ttpci/av7110.h
index 347827925c14..b98a4f3006df 100644
--- a/drivers/media/pci/ttpci/av7110.h
+++ b/drivers/media/pci/ttpci/av7110.h
@@ -93,7 +93,6 @@ struct infrared {
u8 inversion;
u16 last_key;
u16 last_toggle;
- u8 delay_timer_finished;
};


diff --git a/drivers/media/pci/ttpci/av7110_ir.c b/drivers/media/pci/ttpci/av7110_ir.c
index ca05198de2c2..a883caa6488c 100644
--- a/drivers/media/pci/ttpci/av7110_ir.c
+++ b/drivers/media/pci/ttpci/av7110_ir.c
@@ -155,16 +155,16 @@ static void av7110_emit_key(unsigned long parm)
if (timer_pending(&ir->keyup_timer)) {
del_timer(&ir->keyup_timer);
if (ir->last_key != keycode || toggle != ir->last_toggle) {
- ir->delay_timer_finished = 0;
+ ir->input_dev->timer_data = 0;
input_event(ir->input_dev, EV_KEY, ir->last_key, 0);
input_event(ir->input_dev, EV_KEY, keycode, 1);
input_sync(ir->input_dev);
- } else if (ir->delay_timer_finished) {
+ } else if (ir->input_dev->timer_data) {
input_event(ir->input_dev, EV_KEY, keycode, 2);
input_sync(ir->input_dev);
}
} else {
- ir->delay_timer_finished = 0;
+ ir->input_dev->timer_data = 0;
input_event(ir->input_dev, EV_KEY, keycode, 1);
input_sync(ir->input_dev);
}
@@ -206,11 +206,12 @@ static void input_register_keys(struct infrared *ir)


/* called by the input driver after rep[REP_DELAY] ms */
-static void input_repeat_key(unsigned long parm)
+static void input_repeat_key(struct timer_list *t)
{
- struct infrared *ir = (struct infrared *) parm;
+ struct input_dev *dev = from_timer(dev, t, timer);

- ir->delay_timer_finished = 1;
+ /* Key repeat started */
+ dev->timer_data = 1;
}


@@ -365,8 +366,7 @@ int av7110_ir_init(struct av7110 *av7110)
input_free_device(input_dev);
return err;
}
- input_dev->timer.function = input_repeat_key;
- input_dev->timer.data = (unsigned long) &av7110->ir;
+ input_dev->timer.function = (TIMER_FUNC_TYPE)input_repeat_key;

if (av_cnt == 1) {
e = proc_create("av7110_ir", S_IWUSR, NULL, &av7110_ir_proc_fops);
diff --git a/include/linux/input.h b/include/linux/input.h
index fb5e23c7ed98..dcd117bf1027 100644
--- a/include/linux/input.h
+++ b/include/linux/input.h
@@ -70,6 +70,7 @@ struct input_value {
* @repeat_key: stores key code of the last key pressed; used to implement
* software autorepeat
* @timer: timer for software autorepeat
+ * @timer_data: timer data for software autorepeat overrides
* @rep: current values for autorepeat parameters (delay, rate)
* @mt: pointer to multitouch state
* @absinfo: array of &struct input_absinfo elements holding information
@@ -152,6 +153,7 @@ struct input_dev {

unsigned int repeat_key;
struct timer_list timer;
+ unsigned long timer_data;

int rep[REP_CNT];

--
2.7.4


--
Kees Cook
Pixel Security