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authorJacob von Chorus <jacobvonchorus@cwphoto.ca>2016-12-30 14:07:52 -0500
committerZhang Rui <rui.zhang@intel.com>2017-01-06 13:04:00 +0800
commitf53345e8cf027d03187b9417f1f8883c516e1a5b (patch)
tree00409bdde2db6b4de8b4d9dc709bda01564da46a
parent7611fb68062f8d7f416f3272894d1edf7bbff29c (diff)
thermal: core: move tz->device.groups cleanup to thermal_release
The device_unregister call in thermal_zone_device_unregister causes the thermal_zone_device structure to be freed before the call to free the dynamically allocated attribute groups. This leads to a kernel panic. Furthermore, the 4 calls to free the trip point attribute structures occur before the call to unregister the device, leading to a kernel panic when sysfs attempts to access the attributes to remove them. Here is an example of a kernel panic when the cpu thermal zones are removed upon cpu offline: BUG: unable to handle kernel NULL pointer dereference at (null) IP: strlen+0x0/0x20 <snip> Call Trace: ? kernfs_name_hash+0x17/0x80 kernfs_find_ns+0x3f/0xd0 kernfs_remove_by_name_ns+0x36/0xa0 remove_files.isra.1+0x36/0x70 sysfs_remove_group+0x44/0x90 sysfs_remove_groups+0x2e/0x50 device_remove_attrs+0x5e/0x90 device_del+0x1ea/0x350 device_unregister+0x1a/0x60 thermal_zone_device_unregister+0x1f2/0x210 pkg_thermal_cpu_offline+0x14f/0x1a0 [x86_pkg_temp_thermal] ? kzalloc.constprop.2+0x10/0x10 [x86_pkg_temp_thermal] cpuhp_invoke_callback+0x8d/0x3f0 cpuhp_down_callbacks+0x42/0x80 cpuhp_thread_fun+0x8b/0xf0 smpboot_thread_fn+0x110/0x160 kthread+0x101/0x140 ? sort_range+0x30/0x30 ? kthread_park+0x90/0x90 ret_from_fork+0x25/0x30 This patch moves the kfree calls to clean up the dynamic attributes to the thermal_class's thermal_zone_device release function. Cc: Zhang Rui <rui.zhang@intel.com> Cc: Eduardo Valentin <edubezval@gmail.com> Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Tested-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Jacob von Chorus <jacobvonchorus@cwphoto.ca> Signed-off-by: Zhang Rui <rui.zhang@intel.com>
-rw-r--r--drivers/thermal/thermal_core.c10
1 files changed, 5 insertions, 5 deletions
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 641faab6e24b..655591316a88 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -799,6 +799,11 @@ static void thermal_release(struct device *dev)
if (!strncmp(dev_name(dev), "thermal_zone",
sizeof("thermal_zone") - 1)) {
tz = to_thermal_zone(dev);
+ kfree(tz->trip_type_attrs);
+ kfree(tz->trip_temp_attrs);
+ kfree(tz->trip_hyst_attrs);
+ kfree(tz->trips_attribute_group.attrs);
+ kfree(tz->device.groups);
kfree(tz);
} else if (!strncmp(dev_name(dev), "cooling_device",
sizeof("cooling_device") - 1)) {
@@ -1305,10 +1310,6 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
thermal_zone_device_set_polling(tz, 0);
- kfree(tz->trip_type_attrs);
- kfree(tz->trip_temp_attrs);
- kfree(tz->trip_hyst_attrs);
- kfree(tz->trips_attribute_group.attrs);
thermal_set_governor(tz, NULL);
thermal_remove_hwmon_sysfs(tz);
@@ -1316,7 +1317,6 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
idr_destroy(&tz->idr);
mutex_destroy(&tz->lock);
device_unregister(&tz->device);
- kfree(tz->device.groups);
}
EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);