package/broadcom-wl/patches/100-timer_fix.patch

   1 --- a/router/shared/linux_timer.c
   2 +++ b/router/shared/linux_timer.c
   3 @@ -94,6 +94,7 @@ typedef long uclock_t;
   4  #define TFLAG_NONE     0
   5  #define TFLAG_CANCELLED        (1<<0)
   6  #define TFLAG_DELETED  (1<<1)
   7 +#define TFLAG_QUEUED   (1<<2)
   8
   9  struct event {
  10      struct timeval it_interval;
  11 @@ -207,6 +208,7 @@ int timer_create(
  12
  13         event_freelist = event->next;
  14         event->next = NULL;
  15 +       event->flags &= ~TFLAG_QUEUED;
  16
  17         check_event_queue();
  18
  19 @@ -387,6 +389,7 @@ int timer_settime
  20         }
  21
  22         event->flags &= ~TFLAG_CANCELLED;
  23 +       event->flags |= TFLAG_QUEUED;
  24
  25         unblock_timer();
  26
  27 @@ -502,7 +505,15 @@ static void alarm_handler(int i)
  28                 (*(event->func))((timer_t) event, (int)event->arg);
  29
  30                 /* If the event has been cancelled, do NOT put it back on the queue. */
  31 -               if (!(event->flags & TFLAG_CANCELLED)) {
  32 +               /* Check for TFLAG_QUEUED is to avoid pathologic case, when after
  33 +                * dequeueing event handler deletes its own timer and allocates new one
  34 +                * which (at least in some cases) gets the same pointer and thus its
  35 +                * 'flags' will be rewritten, most notably TFLAG_CANCELLED, and, to
  36 +                * complete the disaster, it will be queued. alarm_handler tries to
  37 +                * enqueue 'event' (which is on the same memory position as newly
  38 +                * allocated timer), which results in queueing the same pointer once
  39 +                * more. And this way, loop in event queue is created. */
  40 +               if ( !(event->flags & TFLAG_CANCELLED) && !(event->flags & TFLAG_QUEUED) ) {
  41
  42                         /* if the event is a recurring event, reset the timer and
  43                          * find its correct place in the sorted list of events.
  44 @@ -545,6 +556,7 @@ static void alarm_handler(int i)
  45                                 /* link our new event into the pending event queue. */
  46                                 event->next = *ppevent;
  47                                 *ppevent = event;
  48 +                               event->flags |= TFLAG_QUEUED;
  49                         } else {
  50                                 /* there is no interval, so recycle the event structure.
  51                                  * timer_delete((timer_t) event);