Re: [PATCH] HID: force setting drvdata to NULL when removing the driver
From: Hans de Goede
Date: Tue Apr 02 2019 - 09:52:16 EST
Hi,
On 02-04-19 15:44, Benjamin Tissoires wrote:
Hi Dmitry,
On Fri, Mar 29, 2019 at 11:26 PM Dmitry Torokhov
<dmitry.torokhov@xxxxxxxxx> wrote:
Hi Benjamin,
On Thu, Mar 28, 2019 at 8:52 AM Benjamin Tissoires
<benjamin.tissoires@xxxxxxxxxx> wrote:
Or when the probe failed.
This is a common pattern in the HID drivers to reset the drvdata. Some
do it properly, some do it only in case of failure.
Anyway, it's never a good thing to have breadcrumbs, so force a clean
state when removing or when probe is failing.
Just a data point: driver core already clears drvdata, so as long as
dev_get/set_drvdata() is the same as hid_get/set_drvdata() no special
handling is needed in HID core.
You are correct (as always ;-P). I'll drop the hid-core changes and
send a v2 ASAP.
I was just looking at the same thing. I should have known about this
since I wrote the patch to make the core clear drvdata. I should have
mentioned that, but I was assuming that the hid code was special somehow,
however now I see it just uses a regular device_add, so indeed the core
changes are not necessary.
Given the large hid-logitech-*.c patch-set it might be easier for
Jiri if you split out the hid-logitech-*.c changes into a separate
patch, then he can keep that on his logitech branch (just a thought).
Regards,
Hans
Cheers,
Benjamin
Thanks.
--
Dmitry
On Thu, Mar 28, 2019 at 8:52 AM Benjamin Tissoires
<benjamin.tissoires@xxxxxxxxxx> wrote:
Or when the probe failed.
This is a common pattern in the HID drivers to reset the drvdata. Some
do it properly, some do it only in case of failure.
Anyway, it's never a good thing to have breadcrumbs, so force a clean
state when removing or when probe is failing.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
---
drivers/hid/hid-core.c | 2 ++
drivers/hid/hid-cougar.c | 6 ++----
drivers/hid/hid-gfrm.c | 7 -------
drivers/hid/hid-lenovo.c | 2 --
drivers/hid/hid-logitech-dj.c | 2 --
drivers/hid/hid-logitech-hidpp.c | 8 +++-----
drivers/hid/hid-picolcd_core.c | 7 +------
drivers/hid/hid-sensor-hub.c | 1 -
drivers/hid/wacom_sys.c | 18 +++++-------------
9 files changed, 13 insertions(+), 40 deletions(-)
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index b5a8af8daa74..011e49da4d63 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -2203,6 +2203,7 @@ static int hid_device_probe(struct device *dev)
if (ret) {
hid_close_report(hdev);
hdev->driver = NULL;
+ hid_set_drvdata(hdev, NULL);
}
}
unlock:
@@ -2231,6 +2232,7 @@ static int hid_device_remove(struct device *dev)
else /* default remove */
hid_hw_stop(hdev);
hid_close_report(hdev);
+ hid_set_drvdata(hdev, NULL);
hdev->driver = NULL;
}
diff --git a/drivers/hid/hid-cougar.c b/drivers/hid/hid-cougar.c
index e0bb7b34f3a4..4ff3bc1d25e2 100644
--- a/drivers/hid/hid-cougar.c
+++ b/drivers/hid/hid-cougar.c
@@ -207,7 +207,7 @@ static int cougar_probe(struct hid_device *hdev,
error = hid_parse(hdev);
if (error) {
hid_err(hdev, "parse failed\n");
- goto fail;
+ return error;
}
if (hdev->collection->usage == COUGAR_VENDOR_USAGE) {
@@ -219,7 +219,7 @@ static int cougar_probe(struct hid_device *hdev,
error = hid_hw_start(hdev, connect_mask);
if (error) {
hid_err(hdev, "hw start failed\n");
- goto fail;
+ return error;
}
error = cougar_bind_shared_data(hdev, cougar);
@@ -249,8 +249,6 @@ static int cougar_probe(struct hid_device *hdev,
fail_stop_and_cleanup:
hid_hw_stop(hdev);
-fail:
- hid_set_drvdata(hdev, NULL);
return error;
}
diff --git a/drivers/hid/hid-gfrm.c b/drivers/hid/hid-gfrm.c
index cf477f8c8f4c..1a20997e7750 100644
--- a/drivers/hid/hid-gfrm.c
+++ b/drivers/hid/hid-gfrm.c
@@ -127,12 +127,6 @@ static int gfrm_probe(struct hid_device *hdev, const struct hid_device_id *id)
return ret;
}
-static void gfrm_remove(struct hid_device *hdev)
-{
- hid_hw_stop(hdev);
- hid_set_drvdata(hdev, NULL);
-}
-
static const struct hid_device_id gfrm_devices[] = {
{ HID_BLUETOOTH_DEVICE(0x58, 0x2000),
.driver_data = GFRM100 },
@@ -146,7 +140,6 @@ static struct hid_driver gfrm_driver = {
.name = "gfrm",
.id_table = gfrm_devices,
.probe = gfrm_probe,
- .remove = gfrm_remove,
.input_mapping = gfrm_input_mapping,
.raw_event = gfrm_raw_event,
.input_configured = gfrm_input_configured,
diff --git a/drivers/hid/hid-lenovo.c b/drivers/hid/hid-lenovo.c
index eacc76d2ab96..cde9d22bb3ec 100644
--- a/drivers/hid/hid-lenovo.c
+++ b/drivers/hid/hid-lenovo.c
@@ -869,8 +869,6 @@ static void lenovo_remove_tpkbd(struct hid_device *hdev)
led_classdev_unregister(&data_pointer->led_micmute);
led_classdev_unregister(&data_pointer->led_mute);
-
- hid_set_drvdata(hdev, NULL);
}
static void lenovo_remove_cptkbd(struct hid_device *hdev)
diff --git a/drivers/hid/hid-logitech-dj.c b/drivers/hid/hid-logitech-dj.c
index 826fa1e1c8d9..a75101293755 100644
--- a/drivers/hid/hid-logitech-dj.c
+++ b/drivers/hid/hid-logitech-dj.c
@@ -1094,7 +1094,6 @@ static int logi_dj_probe(struct hid_device *hdev,
hid_parse_fail:
kfifo_free(&djrcv_dev->notif_fifo);
kfree(djrcv_dev);
- hid_set_drvdata(hdev, NULL);
return retval;
}
@@ -1145,7 +1144,6 @@ static void logi_dj_remove(struct hid_device *hdev)
kfifo_free(&djrcv_dev->notif_fifo);
kfree(djrcv_dev);
- hid_set_drvdata(hdev, NULL);
}
static const struct hid_device_id logi_dj_receivers[] = {
diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index 199cc256e9d9..b950a44157a2 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -3237,15 +3237,15 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
if (hidpp->quirks & HIDPP_QUIRK_CLASS_WTP) {
ret = wtp_allocate(hdev, id);
if (ret)
- goto allocate_fail;
+ return ret;
} else if (hidpp->quirks & HIDPP_QUIRK_CLASS_M560) {
ret = m560_allocate(hdev);
if (ret)
- goto allocate_fail;
+ return ret;
} else if (hidpp->quirks & HIDPP_QUIRK_CLASS_K400) {
ret = k400_allocate(hdev);
if (ret)
- goto allocate_fail;
+ return ret;
}
INIT_WORK(&hidpp->work, delayed_work_cb);
@@ -3343,8 +3343,6 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
sysfs_remove_group(&hdev->dev.kobj, &ps_attribute_group);
cancel_work_sync(&hidpp->work);
mutex_destroy(&hidpp->send_mutex);
-allocate_fail:
- hid_set_drvdata(hdev, NULL);
return ret;
}
diff --git a/drivers/hid/hid-picolcd_core.c b/drivers/hid/hid-picolcd_core.c
index c1b29a9eb41a..a5d30f267a7b 100644
--- a/drivers/hid/hid-picolcd_core.c
+++ b/drivers/hid/hid-picolcd_core.c
@@ -550,8 +550,7 @@ static int picolcd_probe(struct hid_device *hdev,
data = kzalloc(sizeof(struct picolcd_data), GFP_KERNEL);
if (data == NULL) {
hid_err(hdev, "can't allocate space for Minibox PicoLCD device data\n");
- error = -ENOMEM;
- goto err_no_cleanup;
+ return -ENOMEM;
}
spin_lock_init(&data->lock);
@@ -613,9 +612,6 @@ static int picolcd_probe(struct hid_device *hdev,
hid_hw_stop(hdev);
err_cleanup_data:
kfree(data);
-err_no_cleanup:
- hid_set_drvdata(hdev, NULL);
-
return error;
}
@@ -651,7 +647,6 @@ static void picolcd_remove(struct hid_device *hdev)
picolcd_exit_cir(data);
picolcd_exit_keys(data);
- hid_set_drvdata(hdev, NULL);
mutex_destroy(&data->mutex);
/* Finally, clean up the picolcd data itself */
kfree(data);
diff --git a/drivers/hid/hid-sensor-hub.c b/drivers/hid/hid-sensor-hub.c
index 4256fdc5cd6d..a3db5d8b382d 100644
--- a/drivers/hid/hid-sensor-hub.c
+++ b/drivers/hid/hid-sensor-hub.c
@@ -755,7 +755,6 @@ static void sensor_hub_remove(struct hid_device *hdev)
}
spin_unlock_irqrestore(&data->lock, flags);
mfd_remove_devices(&hdev->dev);
- hid_set_drvdata(hdev, NULL);
mutex_destroy(&data->mutex);
}
diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c
index a8633b1437b2..c2fb614bff44 100644
--- a/drivers/hid/wacom_sys.c
+++ b/drivers/hid/wacom_sys.c
@@ -2716,14 +2716,12 @@ static int wacom_probe(struct hid_device *hdev,
wacom_wac->features = *((struct wacom_features *)id->driver_data);
features = &wacom_wac->features;
- if (features->check_for_hid_type && features->hid_type != hdev->type) {
- error = -ENODEV;
- goto fail;
- }
+ if (features->check_for_hid_type && features->hid_type != hdev->type)
+ return -ENODEV;
error = kfifo_alloc(&wacom_wac->pen_fifo, WACOM_PKGLEN_MAX, GFP_KERNEL);
if (error)
- goto fail;
+ return error;
wacom_wac->hid_data.inputmode = -1;
wacom_wac->mode_report = -1;
@@ -2741,12 +2739,12 @@ static int wacom_probe(struct hid_device *hdev,
error = hid_parse(hdev);
if (error) {
hid_err(hdev, "parse failed\n");
- goto fail;
+ return error;
}
error = wacom_parse_and_register(wacom, false);
if (error)
- goto fail;
+ return error;
if (hdev->bus == BUS_BLUETOOTH) {
error = device_create_file(&hdev->dev, &dev_attr_speed);
@@ -2757,10 +2755,6 @@ static int wacom_probe(struct hid_device *hdev,
}
return 0;
-
-fail:
- hid_set_drvdata(hdev, NULL);
- return error;
}
static void wacom_remove(struct hid_device *hdev)
@@ -2789,8 +2783,6 @@ static void wacom_remove(struct hid_device *hdev)
wacom_release_resources(wacom);
kfifo_free(&wacom_wac->pen_fifo);
-
- hid_set_drvdata(hdev, NULL);
}
#ifdef CONFIG_PM
--
2.19.2
--
Dmitry