[PATCH] power: charger-manager: Fix accessing invalidated thermal zone device after its unbind
From: Krzysztof Kozlowski
Date: Mon Oct 20 2014 - 10:18:15 EST
Lock corruption happened after unbinding a driver which provided thermal
zone for charger manager.
The charger manager obtained in probe a reference to thermal zone device.
This device was used to report temperature in its own thermal zone and
get_temp call.
The thermal zone's reference was not updated even if device providing it was
unregistered (e.g. by unbinding a driver providing that thermal zone). If such
driver was re-binded then charger manager would still use the old reference.
Reproduction:
1. 'cm-thermal-zone' present in DTS.
2. Fuel gauge driver not exporting temperature property.
$ echo "12-0036" > /sys/bus/i2c/drivers/max17042/unbind
$ cat /sys/devices/virtual/power_supply/battery/temp_ambient
[ 153.450663] ------------[ cut here ]------------
[ 153.455274] WARNING: CPU: 3 PID: 6 at kernel/locking/mutex.c:511 mutex_lock_nested+0x3c4/0x458()
[ 153.464022] DEBUG_LOCKS_WARN_ON(l->magic != l)
[ 153.468275] Modules linked in:
[ 153.471493] CPU: 3 PID: 6 Comm: kworker/u8:0 Tainted: G W 3.17.0-next-20141020-00047-g54f3de817616-dirty #374
[ 153.482432] Workqueue: charger_manager cm_monitor_poller
[ 153.487752] [<c0014d2c>] (unwind_backtrace) from [<c0011c98>] (show_stack+0x10/0x14)
[ 153.495457] [<c0011c98>] (show_stack) from [<c04da6dc>] (dump_stack+0x70/0xbc)
[ 153.502670] [<c04da6dc>] (dump_stack) from [<c0022e94>] (warn_slowpath_common+0x64/0x88)
[ 153.510732] [<c0022e94>] (warn_slowpath_common) from [<c0022f4c>] (warn_slowpath_fmt+0x30/0x40)
[ 153.519413] [<c0022f4c>] (warn_slowpath_fmt) from [<c04dd8a8>] (mutex_lock_nested+0x3c4/0x458)
[ 153.528006] [<c04dd8a8>] (mutex_lock_nested) from [<c03944e4>] (thermal_zone_get_temp+0x38/0x68)
[ 153.536768] [<c03944e4>] (thermal_zone_get_temp) from [<c038fe68>] (cm_get_battery_temperature+0x3c/0xb4)
[ 153.546314] [<c038fe68>] (cm_get_battery_temperature) from [<c0390640>] (cm_monitor+0x78/0x31c)
[ 153.554993] [<c0390640>] (cm_monitor) from [<c03908ec>] (cm_monitor_poller+0x8/0x28)
[ 153.562727] [<c03908ec>] (cm_monitor_poller) from [<c00396b4>] (process_one_work+0x180/0x3f4)
[ 153.571229] [<c00396b4>] (process_one_work) from [<c003998c>] (worker_thread+0x30/0x458)
[ 153.579300] [<c003998c>] (worker_thread) from [<c003f374>] (kthread+0xd8/0xf4)
[ 153.586506] [<c003f374>] (kthread) from [<c000f268>] (ret_from_fork+0x14/0x2c)
[ 153.593703] ---[ end trace b421d57d48f82c7d ]---
[ 360.487375] INFO: task kworker/u8:0:6 blocked for more than 120 seconds.
[ 360.492655] Tainted: G W 3.17.0-next-20141020-00047-g54f3de817616-dirty #374
[ 360.501236] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 360.509047] kworker/u8:0 D c04dbcc8 0 6 2 0x00000000
[ 360.515357] Workqueue: charger_manager cm_monitor_poller
[ 360.520665] [<c04dbcc8>] (__schedule) from [<c04dc4d4>] (schedule_preempt_disabled+0x14/0x20)
[ 360.529203] [<c04dc4d4>] (schedule_preempt_disabled) from [<c04dd6a0>] (mutex_lock_nested+0x1bc/0x458)
[ 360.538493] [<c04dd6a0>] (mutex_lock_nested) from [<c028fbb4>] (regmap_read+0x30/0x60)
[ 360.546405] [<c028fbb4>] (regmap_read) from [<c038eae8>] (max17042_get_property+0x30c/0x350)
[ 360.554808] [<c038eae8>] (max17042_get_property) from [<c038c2cc>] (power_supply_read_temp+0x28/0x58)
[ 360.564008] [<c038c2cc>] (power_supply_read_temp) from [<c03944f8>] (thermal_zone_get_temp+0x4c/0x68)
[ 360.573203] [<c03944f8>] (thermal_zone_get_temp) from [<c038fe68>] (cm_get_battery_temperature+0x3c/0xb4)
[ 360.582749] [<c038fe68>] (cm_get_battery_temperature) from [<c0390640>] (cm_monitor+0x78/0x31c)
[ 360.591428] [<c0390640>] (cm_monitor) from [<c03908ec>] (cm_monitor_poller+0x8/0x28)
[ 360.599165] [<c03908ec>] (cm_monitor_poller) from [<c00396b4>] (process_one_work+0x180/0x3f4)
[ 360.607669] [<c00396b4>] (process_one_work) from [<c003998c>] (worker_thread+0x30/0x458)
[ 360.615733] [<c003998c>] (worker_thread) from [<c003f374>] (kthread+0xd8/0xf4)
[ 360.622946] [<c003f374>] (kthread) from [<c000f268>] (ret_from_fork+0x14/0x2c)
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Fixes: 5c49a6256bed ("charger-manager: Modify the way of checking battery's temperature")
---
drivers/power/charger-manager.c | 21 +++++++++++++++------
include/linux/power/charger-manager.h | 4 +---
2 files changed, 16 insertions(+), 9 deletions(-)
diff --git a/drivers/power/charger-manager.c b/drivers/power/charger-manager.c
index 60688c20594d..d5bdcda8dc5f 100644
--- a/drivers/power/charger-manager.c
+++ b/drivers/power/charger-manager.c
@@ -627,8 +627,14 @@ static int cm_get_battery_temperature(struct charger_manager *cm,
return -ENODEV;
#ifdef CONFIG_THERMAL
- if (cm->tzd_batt) {
- ret = thermal_zone_get_temp(cm->tzd_batt, (unsigned long *)temp);
+ if (cm->use_external_tzd) {
+ struct thermal_zone_device *tzd;
+
+ tzd = thermal_zone_get_zone_by_name(cm->desc->thermal_zone);
+ if (IS_ERR(tzd))
+ return PTR_ERR(tzd);
+
+ ret = thermal_zone_get_temp(tzd, (unsigned long *)temp);
if (!ret)
/* Calibrate temperature unit */
*temp /= 100;
@@ -1590,12 +1596,15 @@ static int cm_init_thermal_data(struct charger_manager *cm,
}
#ifdef CONFIG_THERMAL
if (ret && desc->thermal_zone) {
- cm->tzd_batt =
- thermal_zone_get_zone_by_name(desc->thermal_zone);
- if (IS_ERR(cm->tzd_batt))
- return PTR_ERR(cm->tzd_batt);
+ struct thermal_zone_device *tzd;
+
+ /* Just check if we want to export TEMP_AMBIENT */
+ tzd = thermal_zone_get_zone_by_name(desc->thermal_zone);
+ if (IS_ERR(tzd))
+ return PTR_ERR(tzd);
/* Use external thermometer */
+ cm->use_external_tzd = true;
cm->charger_psy.properties[cm->charger_psy.num_properties] =
POWER_SUPPLY_PROP_TEMP_AMBIENT;
cm->charger_psy.num_properties++;
diff --git a/include/linux/power/charger-manager.h b/include/linux/power/charger-manager.h
index e97fc656a058..f3000d850995 100644
--- a/include/linux/power/charger-manager.h
+++ b/include/linux/power/charger-manager.h
@@ -253,9 +253,7 @@ struct charger_manager {
struct device *dev;
struct charger_desc *desc;
-#ifdef CONFIG_THERMAL
- struct thermal_zone_device *tzd_batt;
-#endif
+ bool use_external_tzd;
bool charger_enabled;
unsigned long fullbatt_vchk_jiffies_at;
--
1.9.1
--
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