PM / wakeup: validate wakeup source before activating it.

A rogue wakeup source not registered in wakeup_sources list is not visible
from wakeup_sources_stats_show. Check if the wakeup source is registered
properly by looking at the timer struct.

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

diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index 7726200..7b5ad9a 100644 (file)
--- a/drivers/base/power/wakeup.c
+++ b/drivers/base/power/wakeup.c
@@ -351,6 +351,20 @@ int device_set_wakeup_enable(struct device *dev, bool enable)
 }
 EXPORT_SYMBOL_GPL(device_set_wakeup_enable);
 
+/**
+ * wakeup_source_not_registered - validate the given wakeup source.
+ * @ws: Wakeup source to be validated.
+ */
+static bool wakeup_source_not_registered(struct wakeup_source *ws)
+{
+       /*
+        * Use timer struct to check if the given source is initialized
+        * by wakeup_source_add.
+        */
+       return ws->timer.function != pm_wakeup_timer_fn ||
+                  ws->timer.data != (unsigned long)ws;
+}
+
 /*
  * The functions below use the observation that each wakeup event starts a
  * period in which the system should not be suspended.  The moment this period
@@ -391,6 +405,10 @@ static void wakeup_source_activate(struct wakeup_source *ws)
 {
        unsigned int cec;
 
+       if (WARN_ONCE(wakeup_source_not_registered(ws),
+                       "unregistered wakeup source\n"))
+               return;
+
        /*
         * active wakeup source should bring the system
         * out of PM_SUSPEND_FREEZE state