| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Thu, 20 Jun 2013 12:39:36 +0200
From: Alexander Holler <holler@...oftware.de>
To: linux-kernel@...r.kernel.org
Cc: Andrew Morton <akpm@...ux-foundation.org>,
rtc-linux@...glegroups.com,
Alessandro Zummo <a.zummo@...ertech.it>,
Alexander Holler <holler@...oftware.de>
Subject: [PATCH 3/9 v2] rtc: rtc-hid-sensor-time: delay registering as rtc into a work
rtc_device_register() might want to read the clock which doesn't work
before the hid device is registered. Therefor we delay the registration of
the rtc driver by moving it to a work.
Signed-off-by: Alexander Holler <holler@...oftware.de>
---
Changes to v1:
I've fixed a bug calling rtc_device_unregister() in remove() which was
necessary in 3.9 but leads to a crash in 3.10 (through the use of devm_*).
Sorry for that, I assume I've resolved a conflict wrong while moving this
patch from 3.9.x to 3.10.
This patch can already be added to -mm. It is only necessary if
rtc_device_register() reads the time (which would fail without this patch).
I've left the "3/9" in the subject only there, because the patch was named
as such before. But the patch is independ if hctosys will be changed or not.
1/9 and 2/9 are already in -mm, 4-9 are in discussion which will need some
time.
Thanks,
Alexander Holler
drivers/rtc/rtc-hid-sensor-time.c | 64 ++++++++++++++++++++++++++++++++++-----
1 file changed, 56 insertions(+), 8 deletions(-)
diff --git a/drivers/rtc/rtc-hid-sensor-time.c b/drivers/rtc/rtc-hid-sensor-time.c
index 7273b01..0767395 100644
--- a/drivers/rtc/rtc-hid-sensor-time.c
+++ b/drivers/rtc/rtc-hid-sensor-time.c
@@ -37,6 +37,11 @@ enum hid_time_channel {
TIME_RTC_CHANNEL_MAX,
};
+struct hid_time_workts {
+ struct work_struct work;
+ struct hid_time_state *time_state;
+};
+
struct hid_time_state {
struct hid_sensor_hub_callbacks callbacks;
struct hid_sensor_common common_attributes;
@@ -46,6 +51,7 @@ struct hid_time_state {
struct completion comp_last_time;
struct rtc_time time_buf;
struct rtc_device *rtc;
+ struct hid_time_workts *workts;
};
static const u32 hid_time_addresses[TIME_RTC_CHANNEL_MAX] = {
@@ -237,6 +243,36 @@ static const struct rtc_class_ops hid_time_rtc_ops = {
.read_time = hid_rtc_read_time,
};
+static void hid_time_register_rtc_work(struct work_struct *work)
+{
+ struct hid_time_state *time_state =
+ container_of(work, struct hid_time_workts, work)
+ ->time_state;
+ struct platform_device *pdev = time_state->callbacks.pdev;
+
+ time_state->rtc = devm_rtc_device_register(&pdev->dev,
+ "hid-sensor-time", &hid_time_rtc_ops,
+ THIS_MODULE);
+ if (IS_ERR_OR_NULL(time_state->rtc)) {
+ struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
+ sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
+ time_state->rtc = NULL;
+ dev_err(&pdev->dev, "rtc device register failed!\n");
+ /*
+ * I haven't a found a way to remove only this device from
+ * hid-sensor-hub. Removing the device a level above (the
+ * complete HID device) doesn't work, because a sensor-hub
+ * might provide more than just a time-sensor and thus we
+ * would remove all sensors not just this one.
+ * So we just leave this driver idling around until I or
+ * someone else has figured out how to remove this device
+ * from hid-sensor-hub.
+ */
+ }
+ time_state->workts = NULL;
+ kfree(work);
+}
+
static int hid_time_probe(struct platform_device *pdev)
{
int ret = 0;
@@ -279,22 +315,34 @@ static int hid_time_probe(struct platform_device *pdev)
return ret;
}
- time_state->rtc = devm_rtc_device_register(&pdev->dev,
- "hid-sensor-time", &hid_time_rtc_ops,
- THIS_MODULE);
-
- if (IS_ERR(time_state->rtc)) {
- dev_err(&pdev->dev, "rtc device register failed!\n");
- return PTR_ERR(time_state->rtc);
+ /*
+ * The HID device has to be registered to read the clock.
+ * Because rtc_device_register() might read the time, we have to delay
+ * rtc_device_register() to a work in order to finish the probe before.
+ */
+ time_state->workts = kmalloc(sizeof(struct hid_time_workts),
+ GFP_KERNEL);
+ if (time_state->workts == NULL) {
+ sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
+ return -ENOMEM;
}
+ time_state->workts->time_state = time_state;
+ INIT_WORK(&time_state->workts->work,
+ hid_time_register_rtc_work);
+ schedule_work(&time_state->workts->work);
- return ret;
+ return 0;
}
static int hid_time_remove(struct platform_device *pdev)
{
struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
+ struct hid_time_state *time_state = platform_get_drvdata(pdev);
+ if (time_state->workts) {
+ flush_work(&time_state->workts->work);
+ WARN_ON(time_state->workts != NULL);
+ }
sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
return 0;
--
1.8.1.4
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists