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authorHans de Goede <hdegoede@redhat.com>2022-02-28 22:59:34 -0800
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2022-02-28 23:26:30 -0800
commit65de58c2a5b4bbe8ee1a42a5ee5b88163efa9855 (patch)
treeb9baf75b005ef2461437d74cac991a21a3c0c3ee /drivers/input/touchscreen/goodix.c
parentInput: goodix - use input_copy_abs() helper (diff)
downloadlinux-dev-65de58c2a5b4bbe8ee1a42a5ee5b88163efa9855.tar.xz
linux-dev-65de58c2a5b4bbe8ee1a42a5ee5b88163efa9855.zip
Input: goodix - fix race on driver unbind
Because there is no way to detect if the touchscreen has pen support, the driver is allocating and registering the input_pen input_dev on receiving the first pen event. But this means that the input_dev gets allocated after the request_irq() call which means that the devm framework will free it before disabling the irq, leaving a window where the irq handler may run and reference the free-ed input_dev. To fix this move the allocation of the input_pen input_dev to before the request_irq() call, while still only registering it on the first pen event so that the driver does not advertise pen capability on touchscreens without it (most goodix touchscreens do not have pen support). Signed-off-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20220131143539.109142-4-hdegoede@redhat.com Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'drivers/input/touchscreen/goodix.c')
-rw-r--r--drivers/input/touchscreen/goodix.c35
1 files changed, 22 insertions, 13 deletions
diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index 04baf5a770f5..b055815611de 100644
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c
@@ -297,14 +297,14 @@ static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
return -ENOMSG;
}
-static struct input_dev *goodix_create_pen_input(struct goodix_ts_data *ts)
+static int goodix_create_pen_input(struct goodix_ts_data *ts)
{
struct device *dev = &ts->client->dev;
struct input_dev *input;
input = devm_input_allocate_device(dev);
if (!input)
- return NULL;
+ return -ENOMEM;
input_copy_abs(input, ABS_X, ts->input_dev, ABS_MT_POSITION_X);
input_copy_abs(input, ABS_Y, ts->input_dev, ABS_MT_POSITION_Y);
@@ -331,25 +331,23 @@ static struct input_dev *goodix_create_pen_input(struct goodix_ts_data *ts)
input->id.product = 0x1001;
input->id.version = ts->version;
- if (input_register_device(input) != 0) {
- input_free_device(input);
- return NULL;
- }
-
- return input;
+ ts->input_pen = input;
+ return 0;
}
static void goodix_ts_report_pen_down(struct goodix_ts_data *ts, u8 *data)
{
- int input_x, input_y, input_w;
+ int input_x, input_y, input_w, error;
u8 key_value;
- if (!ts->input_pen) {
- ts->input_pen = goodix_create_pen_input(ts);
- if (!ts->input_pen)
- return;
+ if (!ts->pen_input_registered) {
+ error = input_register_device(ts->input_pen);
+ ts->pen_input_registered = (error == 0) ? 1 : error;
}
+ if (ts->pen_input_registered < 0)
+ return;
+
if (ts->contact_size == 9) {
input_x = get_unaligned_le16(&data[4]);
input_y = get_unaligned_le16(&data[6]);
@@ -1207,6 +1205,17 @@ static int goodix_configure_dev(struct goodix_ts_data *ts)
return error;
}
+ /*
+ * Create the input_pen device before goodix_request_irq() calls
+ * devm_request_threaded_irq() so that the devm framework frees
+ * it after disabling the irq.
+ * Unfortunately there is no way to detect if the touchscreen has pen
+ * support, so registering the dev is delayed till the first pen event.
+ */
+ error = goodix_create_pen_input(ts);
+ if (error)
+ return error;
+
ts->irq_flags = goodix_irq_flags[ts->int_trigger_type] | IRQF_ONESHOT;
error = goodix_request_irq(ts);
if (error) {