[PATCH 3.15 15/84] thermal: hwmon: Make the check for critical temp valid consistent

Greg Kroah-Hartman
2014-07-15T23:45:00Z

From: Aaron Lu <aaron.lu@intel.com>

commit e8db5d6736a712a3e2280c0e31f4b301d85172d8 upstream.

On 05/21/2014 04:22 PM, Aaron Lu wrote:
> On 05/21/2014 01:57 PM, Kui Zhang wrote:
>> Hello,
>>
>> I get following error when rmmod thermal.
>>
>> rmmod thermal
>> Killed

While dealing with this problem, I found another problem that also
results in a kernel crash on thermal module removal:

From: Aaron Lu <aaron.lu@intel.com>
Date: Wed, 21 May 2014 16:05:38 +0800
Subject: [PATCH 3.15 15/84] thermal: hwmon: Make the check for critical temp valid consistent

We used the tz->ops->get_crit_temp && !tz->ops->get_crit_temp(tz, temp)
to decide if we need to create the temp_crit attribute file but we just
check if tz->ops->get_crit_temp exists to decide if we need to remove
that attribute file. Some ACPI thermal zone doesn't have a valid critical
trip point and that would result in removing a non-existent device file
on thermal module unload.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/thermal/thermal_hwmon.c | 33 ++++++++++++++++++---------------
1 file changed, 18 insertions(+), 15 deletions(-)

--- a/drivers/thermal/thermal_hwmon.c
+++ b/drivers/thermal/thermal_hwmon.c
@@ -140,6 +140,12 @@ thermal_hwmon_lookup_temp(const struct t
return NULL;
}

+static bool thermal_zone_crit_temp_valid(struct thermal_zone_device *tz)
+{
+ unsigned long temp;
+ return tz->ops->get_crit_temp && !tz->ops->get_crit_temp(tz, &temp);
+}
+
int thermal_add_hwmon_sysfs(struct thermal_zone_device *tz)
{
struct thermal_hwmon_device *hwmon;
@@ -189,21 +195,18 @@ int thermal_add_hwmon_sysfs(struct therm
if (result)
goto free_temp_mem;

- if (tz->ops->get_crit_temp) {
- unsigned long temperature;
- if (!tz->ops->get_crit_temp(tz, &temperature)) {
- snprintf(temp->temp_crit.name,
- sizeof(temp->temp_crit.name),
+ if (thermal_zone_crit_temp_valid(tz)) {
+ snprintf(temp->temp_crit.name,
+ sizeof(temp->temp_crit.name),
"temp%d_crit", hwmon->count);
- temp->temp_crit.attr.attr.name = temp->temp_crit.name;
- temp->temp_crit.attr.attr.mode = 0444;
- temp->temp_crit.attr.show = temp_crit_show;
- sysfs_attr_init(&temp->temp_crit.attr.attr);
- result = device_create_file(hwmon->device,
- &temp->temp_crit.attr);
- if (result)
- goto unregister_input;
- }
+ temp->temp_crit.attr.attr.name = temp->temp_crit.name;
+ temp->temp_crit.attr.attr.mode = 0444;
+ temp->temp_crit.attr.show = temp_crit_show;
+ sysfs_attr_init(&temp->temp_crit.attr.attr);
+ result = device_create_file(hwmon->device,
+ &temp->temp_crit.attr);
+ if (result)
+ goto unregister_input;
}

mutex_lock(&thermal_hwmon_list_lock);
@@ -250,7 +253,7 @@ void thermal_remove_hwmon_sysfs(struct t
}

device_remove_file(hwmon->device, &temp->temp_input.attr);
- if (tz->ops->get_crit_temp)
+ if (thermal_zone_crit_temp_valid(tz))
device_remove_file(hwmon->device, &temp->temp_crit.attr);

mutex_lock(&thermal_hwmon_list_lock);