diff mbox series

[v2,4/4] thermal: intel: int340x: Improve int340x_thermal_set_trip_temp()

Message ID 3719164.kQq0lBPeGt@kreacher
State New
Headers
Series thermal: intel: int340x: Assorted cleanups |

Commit Message

Rafael J. Wysocki Jan. 30, 2023, 6:47 p.m. UTC 
  From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Instead of using snprintf() to populate the ACPI object name in
int340x_thermal_set_trip_temp(), use an appropriate initializer
and make the function fail if its trip argument is greater than 9,
because ACPI object names can only be 4 characters long and it does
not make sense to even try to evaluate objects with longer names (that
argument is guaranteed to be non-negative, because it comes from the
thermal code that will not pass negative trip numbers to zone
callbacks).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---

v1 -> v2: New patch in v2

---
 drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Comments

Daniel Lezcano Jan. 31, 2023, 3:39 p.m. UTC | #1 
On 30/01/2023 19:47, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Instead of using snprintf() to populate the ACPI object name in
> int340x_thermal_set_trip_temp(), use an appropriate initializer
> and make the function fail if its trip argument is greater than 9,
> because ACPI object names can only be 4 characters long and it does
> not make sense to even try to evaluate objects with longer names (that
> argument is guaranteed to be non-negative, because it comes from the
> thermal code that will not pass negative trip numbers to zone
> callbacks).
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---

Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
diff mbox series

Patch

Index: linux-pm/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c
===================================================================
--- linux-pm.orig/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c
+++ linux-pm/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c
@@ -42,10 +42,12 @@  static int int340x_thermal_set_trip_temp
 					 int trip, int temp)
 {
 	struct int34x_thermal_zone *d = zone->devdata;
+	char name[] = {'P', 'A', 'T', '0' + trip, '\0'};
 	acpi_status status;
-	char name[10];
 
-	snprintf(name, sizeof(name), "PAT%d", trip);
+	if (trip > 9)
+		return -EINVAL;
+
 	status = acpi_execute_simple_method(d->adev->handle, name,
 					    millicelsius_to_deci_kelvin(temp));
 	if (ACPI_FAILURE(status))