power: 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: jinqian <jinqian@google.com>
Change-Id: Id4b2fdb3cf7fecb2fe7576b2305cd337974665c9

diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index 4b35cc08c3b6b3e9491e95858d07ed5ed243902d..6686e5ff6041474e118c3e15a11bad0ab2690e9a 100644 (file)
--- a/drivers/base/power/wakeup.c
+++ b/drivers/base/power/wakeup.c
@@ -343,6 +343,20 @@ 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
@@ -383,6 +397,10 @@ static void wakeup_source_activate(struct wakeup_source *ws)
 {
        unsigned int cec;
 
+       if (WARN(wakeup_source_not_registered(ws),
+                       "unregistered wakeup source\n"))
+               return;
+
        /*
         * active wakeup source should bring the system
         * out of PM_SUSPEND_FREEZE state