Merge tag 'v3.14.12' of git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable into linux-lng-v3.14.xlinux-lng-3.14.12-2014.07

This is the 3.14.12 stable release

Conflicts:
	arch/arm/mm/proc-v7-3level.S
	kernel/hrtimer.c
	mm/hugetlb.c

1 files changed, 22 insertions, 0 deletions

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index f8a5880f96c9..e3cd58bc7513 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -234,6 +234,11 @@ again:
 			goto again;
 		}
 		timer->base = new_base;
+	} else {
+		if (cpu != this_cpu && hrtimer_check_target(timer, new_base)) {
+			cpu = this_cpu;
+			goto again;
+		}
 	}
 	return new_base;
 }
@@ -569,6 +574,23 @@ hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal)
 
 	cpu_base->expires_next.tv64 = expires_next.tv64;
 
+	/*
+	 * If a hang was detected in the last timer interrupt then we
+	 * leave the hang delay active in the hardware. We want the
+	 * system to make progress. That also prevents the following
+	 * scenario:
+	 * T1 expires 50ms from now
+	 * T2 expires 5s from now
+	 *
+	 * T1 is removed, so this code is called and would reprogram
+	 * the hardware to 5s from now. Any hrtimer_start after that
+	 * will not reprogram the hardware due to hang_detected being
+	 * set. So we'd effectivly block all timers until the T2 event
+	 * fires.
+	 */
+	if (cpu_base->hang_detected)
+		return;
+
 	tick_program_event(cpu_base->expires_next, 1);
 }