From 6757a7abe47bcb12cb2d45661067e182424b0ee3 Mon Sep 17 00:00:00 2001 From: Srinivas Pandruvada Date: Mon, 23 Jan 2023 09:21:10 -0800 Subject: thermal: intel: int340x: Protect trip temperature from concurrent updates Trip temperatures are read using ACPI methods and stored in the memory during zone initializtion and when the firmware sends a notification for change. This trip temperature is returned when the thermal core calls via callback get_trip_temp(). But it is possible that while updating the memory copy of the trips when the firmware sends a notification for change, thermal core is reading the trip temperature via the callback get_trip_temp(). This may return invalid trip temperature. To address this add a mutex to protect the invalid temperature reads in the callback get_trip_temp() and int340x_thermal_read_trips(). Fixes: 5fbf7f27fa3d ("Thermal/int340x: Add common thermal zone handler") Signed-off-by: Srinivas Pandruvada Cc: 5.0+ # 5.0+ Signed-off-by: Rafael J. Wysocki --- .../intel/int340x_thermal/int340x_thermal_zone.c | 18 +++++++++++++++--- .../intel/int340x_thermal/int340x_thermal_zone.h | 1 + 2 files changed, 16 insertions(+), 3 deletions(-) (limited to 'drivers') diff --git a/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c b/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c index 62c0aa5d0783..852f6c579af5 100644 --- a/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c +++ b/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c @@ -44,11 +44,13 @@ static int int340x_thermal_get_trip_temp(struct thermal_zone_device *zone, int trip, int *temp) { struct int34x_thermal_zone *d = zone->devdata; - int i; + int i, ret = 0; if (d->override_ops && d->override_ops->get_trip_temp) return d->override_ops->get_trip_temp(zone, trip, temp); + mutex_lock(&d->trip_mutex); + if (trip < d->aux_trip_nr) *temp = d->aux_trips[trip]; else if (trip == d->crt_trip_id) @@ -66,10 +68,12 @@ static int int340x_thermal_get_trip_temp(struct thermal_zone_device *zone, } } if (i == INT340X_THERMAL_MAX_ACT_TRIP_COUNT) - return -EINVAL; + ret = -EINVAL; } - return 0; + mutex_unlock(&d->trip_mutex); + + return ret; } static int int340x_thermal_get_trip_type(struct thermal_zone_device *zone, @@ -180,6 +184,8 @@ int int340x_thermal_read_trips(struct int34x_thermal_zone *int34x_zone) int trip_cnt = int34x_zone->aux_trip_nr; int i; + mutex_lock(&int34x_zone->trip_mutex); + int34x_zone->crt_trip_id = -1; if (!int340x_thermal_get_trip_config(int34x_zone->adev->handle, "_CRT", &int34x_zone->crt_temp)) @@ -207,6 +213,8 @@ int int340x_thermal_read_trips(struct int34x_thermal_zone *int34x_zone) int34x_zone->act_trips[i].valid = true; } + mutex_unlock(&int34x_zone->trip_mutex); + return trip_cnt; } EXPORT_SYMBOL_GPL(int340x_thermal_read_trips); @@ -230,6 +238,8 @@ struct int34x_thermal_zone *int340x_thermal_zone_add(struct acpi_device *adev, if (!int34x_thermal_zone) return ERR_PTR(-ENOMEM); + mutex_init(&int34x_thermal_zone->trip_mutex); + int34x_thermal_zone->adev = adev; int34x_thermal_zone->override_ops = override_ops; @@ -281,6 +291,7 @@ err_thermal_zone: acpi_lpat_free_conversion_table(int34x_thermal_zone->lpat_table); kfree(int34x_thermal_zone->aux_trips); err_trip_alloc: + mutex_destroy(&int34x_thermal_zone->trip_mutex); kfree(int34x_thermal_zone); return ERR_PTR(ret); } @@ -292,6 +303,7 @@ void int340x_thermal_zone_remove(struct int34x_thermal_zone thermal_zone_device_unregister(int34x_thermal_zone->zone); acpi_lpat_free_conversion_table(int34x_thermal_zone->lpat_table); kfree(int34x_thermal_zone->aux_trips); + mutex_destroy(&int34x_thermal_zone->trip_mutex); kfree(int34x_thermal_zone); } EXPORT_SYMBOL_GPL(int340x_thermal_zone_remove); diff --git a/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.h b/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.h index 3b4971df1b33..8f9872afd0d3 100644 --- a/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.h +++ b/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.h @@ -32,6 +32,7 @@ struct int34x_thermal_zone { struct thermal_zone_device_ops *override_ops; void *priv_data; struct acpi_lpat_conversion_table *lpat_table; + struct mutex trip_mutex; }; struct int34x_thermal_zone *int340x_thermal_zone_add(struct acpi_device *, -- cgit v1.2.3