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>

2 files changed, 8 insertions, 0 deletions

diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
index 6859661c9d31..277530a5786c 100644
--- 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 2a19120c32bd..fb0672baff40 100644
--- 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