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author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-05-03 08:31:45 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-05-03 08:31:45 -0700 |
commit | 98facf0e1ee3d2db313863a283e499ed1c0b5b79 (patch) | |
tree | 909bb560a9100ebbc7b7b0e34f47a1357be1ac67 /kernel | |
parent | 00622e61eda46c7f8833afbee6bd34449a9a4e7e (diff) | |
parent | 98a01e779f3c66b0b11cd7e64d531c0e41c95762 (diff) | |
download | linux-stable-98facf0e1ee3d2db313863a283e499ed1c0b5b79.tar.gz linux-stable-98facf0e1ee3d2db313863a283e499ed1c0b5b79.tar.bz2 linux-stable-98facf0e1ee3d2db313863a283e499ed1c0b5b79.zip |
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:
"This update brings along:
- Two fixes for long standing bugs in the hrtimer code, one which
prevents remote enqueuing and the other preventing arbitrary delays
after a interrupt hang was detected
- A fix in the timer wheel which prevents math overflow
- A fix for a long standing issue with the architected ARM timer
related to the C3STOP mechanism.
- A trivial compile fix for nspire SoC clocksource"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timer: Prevent overflow in apply_slack
hrtimer: Prevent remote enqueue of leftmost timers
hrtimer: Prevent all reprogramming if hang detected
clocksource: nspire: Fix compiler warning
clocksource: arch_arm_timer: Fix age-old arch timer C3STOP detection issue
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/hrtimer.c | 22 | ||||
-rw-r--r-- | kernel/timer.c | 2 |
2 files changed, 23 insertions, 1 deletions
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index d55092ceee29..6b715c0af1b1 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; + if (cpu_base->expires_next.tv64 != KTIME_MAX) tick_program_event(cpu_base->expires_next, 1); } diff --git a/kernel/timer.c b/kernel/timer.c index 87bd529879c2..3bb01a323b2a 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -838,7 +838,7 @@ unsigned long apply_slack(struct timer_list *timer, unsigned long expires) bit = find_last_bit(&mask, BITS_PER_LONG); - mask = (1 << bit) - 1; + mask = (1UL << bit) - 1; expires_limit = expires_limit & ~(mask); |