thermal: add a warning for temperature emulation feature

Because this feature is for debuging purposes, it is highly
recommended to do not enable this on production systems.
This patch adds warnings for system integrators, so that
people are aware of this potential security issue.

Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
index 6859661..277530a 100644 (file)
--- a/Documentation/thermal/sysfs-api.txt
+++ b/Documentation/thermal/sysfs-api.txt
@@ -265,6 +265,10 @@ emul_temp
        Unit: millidegree Celsius
        WO, Optional
 
+         WARNING: Be careful while enabling this option on production systems,
+         because userland can easily disable the thermal policy by simply
+         flooding this sysfs node with low temperature values.
+
 *****************************
 * Cooling device attributes *
 *****************************

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 2a19120..fb0672b 100644 (file)
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -86,6 +86,10 @@ config THERMAL_EMULATION
          user can manually input temperature and test the different trip
          threshold behaviour for simulation purpose.
 
+         WARNING: Be careful while enabling this option on production systems,
+         because userland can easily disable the thermal policy by simply
+         flooding this sysfs node with low temperature values.
+
 config SPEAR_THERMAL
        bool "SPEAr thermal sensor driver"
        depends on PLAT_SPEAR