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  1. 02 Jan, 2024 23 commits
  3. 21 Dec, 2023 1 commit
  5. 15 Dec, 2023 1 commit
    • Rafael J. Wysocki's avatar
      thermal: core: Fix NULL pointer dereference in zone registration error path · 04e6ccfc
      Rafael J. Wysocki authored 
      If device_register() in thermal_zone_device_register_with_trips()
returns an error, the tz variable is set to NULL and subsequently
dereferenced in kfree(tz->tzp).

Commit adc8749b ("thermal/drivers/core: Use put_device() if
device_register() fails") added the tz = NULL assignment in question to
avoid a possible double-free after dropping the reference to the zone
device.  However, after commit 4649620d ("thermal: core: Make
thermal_zone_device_unregister() return after freeing the zone"), that
assignment has become redundant, because dropping the reference to the
zone device does not cause the zone object to be freed any more.

Drop it to address the NULL pointer dereference.

Fixes: 3d439b1a ("thermal/core: Alloc-copy-free the thermal zone parameters structure")
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: default avatarLukasz Luba <lukasz.luba@arm.com>
      04e6ccfc
  7. 13 Dec, 2023 6 commits
  9. 12 Dec, 2023 2 commits
    • Rafael J. Wysocki's avatar
      thermal: core: Rework thermal zone availability check · b38aa87f
      Rafael J. Wysocki authored 
      In order to avoid running __thermal_zone_device_update() for thermal
zones going away, the thermal zone lock is held around device_del()
in thermal_zone_device_unregister() and thermal_zone_device_update()
passes the given thermal zone device to device_is_registered().
This allows thermal_zone_device_update() to skip the
__thermal_zone_device_update() if device_del() has already run for
the thermal zone at hand.

However, instead of looking at driver core internals, the thermal
subsystem may as well rely on its own data structures for this
purpose.  Namely, if the thermal zone is not present in
thermal_tz_list, it can be regarded as unavailable, which in fact is
already the case in thermal_zone_device_unregister().  Accordingly,
the device_is_registered() check in thermal_zone_device_update() can
be replaced with checking whether or not the node list_head in struct
thermal_zone_device is empty, in which case it is not there in
thermal_tz_list.

To make this work, though, it is necessary to initialize tz->node
in thermal_zone_device_register_with_trips() before registering the
thermal zone device and it needs to be added to thermal_tz_list and
deleted from it under its zone lock.

After the above modifications, the zone lock does not need to be
held around device_del() in thermal_zone_device_unregister() any more.
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-and-tested-by: default avatarLukasz Luba <lukasz.luba@arm.com>
Acked-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
      b38aa87f
    • Rafael J. Wysocki's avatar
      thermal: Drop redundant and confusing device_is_registered() checks · c3ffdfff
      Rafael J. Wysocki authored 
      Multiple places in the thermal subsystem (most importantly, sysfs
attribute callback functions) check if the given thermal zone device is
still registered in order to return early in case the device_del() in
thermal_zone_device_unregister() has run already.

However, after thermal_zone_device_unregister() has been made wait for
all of the zone-related activity to complete before returning, it is
not necessary to do that any more, because all of the code holding a
reference to the thermal zone device object will be waited for even if
it does not do anything special to enforce this.

Accordingly, drop all of the device_is_registered() checks that are now
redundant and get rid of the zone locking that is not necessary any more
after dropping them.
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-and-tested-by: default avatarLukasz Luba <lukasz.luba@arm.com>
Acked-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
      c3ffdfff
  11. 11 Dec, 2023 1 commit
  13. 06 Dec, 2023 2 commits
    • Rafael J. Wysocki's avatar
      thermal: sysfs: Rework the reading of trip point attributes · 18dfb0e4
      Rafael J. Wysocki authored 
      Rework the _show() callback functions for the trip point temperature,
hysteresis and type attributes to avoid copying the values of struct
thermal_trip fields that they do not use and make them carry out the
same validation checks as the corresponding _store() callback functions.

No intentional functional impact.
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
      18dfb0e4
    • Rafael J. Wysocki's avatar
      thermal: sysfs: Rework the handling of trip point updates · be0a3600
      Rafael J. Wysocki authored 
      Both trip_point_temp_store() and trip_point_hyst_store() use
thermal_zone_set_trip() to update a given trip point, but none of them
actually needs to change more than one field in struct thermal_trip
representing it.  However, each of them effectively calls
__thermal_zone_get_trip() twice in a row for the same trip index value,
once directly and once via thermal_zone_set_trip(), which is not
particularly efficient, and the way in which thermal_zone_set_trip()
carries out the update is not particularly straightforward.

Moreover, input processing need not be done under the thermal zone lock
in any of these functions.

Rework trip_point_temp_store() and trip_point_hyst_store() to address
the above, move the part of thermal_zone_set_trip() that is still
useful to a new function called thermal_zone_trip_updated() and drop
the rest of it.

While at it, make trip_point_hyst_store() reject negative hysteresis
values.
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
      be0a3600
  15. 30 Nov, 2023 1 commit
  17. 28 Nov, 2023 3 commits
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