Files
linux/include/linux
Rafael J. Wysocki 4e814173a8 thermal: core: Fix thermal zone suspend-resume synchronization
There are 3 synchronization issues with thermal zone suspend-resume
during system-wide transitions:

 1. The resume code runs in a PM notifier which is invoked after user
    space has been thawed, so it can run concurrently with user space
    which can trigger a thermal zone device removal.  If that happens,
    the thermal zone resume code may use a stale pointer to the next
    list element and crash, because it does not hold thermal_list_lock
    while walking thermal_tz_list.

 2. The thermal zone resume code calls thermal_zone_device_init()
    outside the zone lock, so user space or an update triggered by
    the platform firmware may see an inconsistent state of a
    thermal zone leading to unexpected behavior.

 3. Clearing the in_suspend global variable in thermal_pm_notify()
    allows __thermal_zone_device_update() to continue for all thermal
    zones and it may as well run before the thermal_tz_list walk (or
    at any point during the list walk for that matter) and attempt to
    operate on a thermal zone that has not been resumed yet.  It may
    also race destructively with thermal_zone_device_init().

To address these issues, add thermal_list_lock locking to
thermal_pm_notify(), especially arount the thermal_tz_list,
make it call thermal_zone_device_init() back-to-back with
__thermal_zone_device_update() under the zone lock and replace
in_suspend with per-zone bool "suspend" indicators set and unset
under the given zone's lock.

Link: https://lore.kernel.org/linux-pm/20231218162348.69101-1-bo.ye@mediatek.com/
Reported-by: Bo Ye <bo.ye@mediatek.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-12-28 14:20:15 +01:00
..
2023-10-05 09:13:42 -07:00
2023-10-24 13:08:14 -07:00
2023-11-04 10:22:52 +01:00
2023-09-18 09:28:22 +01:00
2023-08-23 08:21:37 +01:00
2023-09-11 08:13:18 +00:00
2023-11-10 13:54:58 +00:00
2023-10-11 08:46:01 -07:00
2023-09-22 08:52:13 -06:00
2023-11-01 22:33:53 -07:00
2023-10-30 21:48:22 -04:00
2023-10-04 10:41:56 -07:00
2023-10-04 10:41:56 -07:00
2023-09-11 23:59:47 -04:00
2023-10-25 20:19:00 +02:00
2023-09-13 10:48:48 +02:00
2023-10-12 09:58:02 +02:00
2023-10-11 10:11:54 -07:00
2023-10-18 14:43:21 -07:00
2023-10-04 10:41:57 -07:00
2023-10-16 12:44:06 -04:00
2023-10-16 12:44:06 -04:00
2023-11-13 11:02:30 +00:00
2023-10-18 10:01:33 +02:00
2023-10-27 10:51:41 +01:00
2023-10-18 14:34:16 -07:00
2023-11-15 04:18:31 +01:00
2023-09-29 17:20:46 -07:00
2023-10-03 21:18:13 +02:00
2023-11-10 09:20:55 +01:00
2023-10-06 11:01:23 +02:00
2023-10-06 11:01:23 +02:00
2023-09-11 22:10:47 +02:00
2023-10-15 13:19:42 +01:00
2023-11-01 10:02:18 +00:00
2023-10-18 14:43:21 -07:00
2023-11-03 09:16:42 +00:00
2023-10-18 14:43:21 -07:00
2023-09-14 16:16:36 +02:00
2023-10-27 18:04:28 +08:00
2023-08-24 13:27:47 -05:00
2023-10-18 14:34:18 -07:00