hrtimer: prevent negative expiry value after clock_was_set()

[safe/jmp/linux-2.6] / kernel / hrtimer.c

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 647a40e..f394d2a 100644 (file)
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -501,6 +501,13 @@ static void hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base)
                        continue;
                timer = rb_entry(base->first, struct hrtimer, node);
                expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
+               /*
+                * clock_was_set() has changed base->offset so the
+                * result might be negative. Fix it up to prevent a
+                * false positive in clockevents_program_event()
+                */
+               if (expires.tv64 < 0)
+                       expires.tv64 = 0;
                if (expires.tv64 < cpu_base->expires_next.tv64)
                        cpu_base->expires_next = expires;
        }