clockevent: simplify list operations

[sfrench/cifs-2.6.git] / kernel / time / clockevents.c

diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 822beebe664a59e98d3557c98a7ff8632423f6a1..1d327f6db4241330990060ee235037baf6df2fdd 100644 (file)
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -41,6 +41,11 @@ unsigned long clockevent_delta2ns(unsigned long latch,
 {
        u64 clc = ((u64) latch << evt->shift);
 
+       if (unlikely(!evt->mult)) {
+               evt->mult = 1;
+               WARN_ON(1);
+       }
+
        do_div(clc, evt->mult);
        if (clc < 1000)
                clc = 1000;
@@ -78,6 +83,11 @@ int clockevents_program_event(struct clock_event_device *dev, ktime_t expires,
        unsigned long long clc;
        int64_t delta;
 
+       if (unlikely(expires.tv64 < 0)) {
+               WARN_ON_ONCE(1);
+               return -ETIME;
+       }
+
        delta = ktime_to_ns(ktime_sub(expires, now));
 
        if (delta <= 0)
@@ -146,6 +156,14 @@ static void clockevents_notify_released(void)
 void clockevents_register_device(struct clock_event_device *dev)
 {
        BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
+       /*
+        * A nsec2cyc multiplicator of 0 is invalid and we'd crash
+        * on it, so fix it up and emit a warning:
+        */
+       if (unlikely(!dev->mult)) {
+               dev->mult = 1;
+               WARN_ON(1);
+       }
 
        spin_lock(&clockevents_lock);
 
@@ -200,6 +218,8 @@ void clockevents_exchange_device(struct clock_event_device *old,
  */
 void clockevents_notify(unsigned long reason, void *arg)
 {
+       struct list_head *node, *tmp;
+
        spin_lock(&clockevents_lock);
        clockevents_do_notify(reason, arg);
 
@@ -209,13 +229,8 @@ void clockevents_notify(unsigned long reason, void *arg)
                 * Unregister the clock event devices which were
                 * released from the users in the notify chain.
                 */
-               while (!list_empty(&clockevents_released)) {
-                       struct clock_event_device *dev;
-
-                       dev = list_entry(clockevents_released.next,
-                                        struct clock_event_device, list);
-                       list_del(&dev->list);
-               }
+               list_for_each_safe(node, tmp, &clockevents_released)
+                       list_del(node);
                break;
        default:
                break;