user/sven/linux.git/kernel/time/alarmtimer.c, branch v4.9.243

alarmtimer: Change remaining ENOTSUPP to EOPNOTSUPP

2019-11-10T10:23:32Z

Fix backport of commit f18ddc13af981ce3c7b7f26925f099e7c6929aba upstream. Update backport to change ENOTSUPP to EOPNOTSUPP in alarm_timer_{del,set}(), which were removed in f2c45807d3992fe0f173f34af9c347d907c31686 in v4.13-rc1. Fixes: 65b7a5a36afb11a6769a70308c1ef3a2afae6bf4 Signed-off-by: Petr Vorel Acked-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman

alarmtimer: Use EOPNOTSUPP instead of ENOTSUPP

2019-10-05T10:30:33Z

commit f18ddc13af981ce3c7b7f26925f099e7c6929aba upstream. ENOTSUPP is not supposed to be returned to userspace. This was found on an OpenPower machine, where the RTC does not support set_alarm. On that system, a clock_nanosleep(CLOCK_REALTIME_ALARM, ...) results in "524 Unknown error 524" Replace it with EOPNOTSUPP which results in the expected "95 Operation not supported" error. Fixes: 1c6b39ad3f01 (alarmtimers: Return -ENOTSUPP if no RTC device is present) Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190903171802.28314-1-cascardo@canonical.com Signed-off-by: Greg Kroah-Hartman

alarmtimer: Prevent overflow for relative nanosleep

2018-10-04T00:01:45Z

[ Upstream commit 5f936e19cc0ef97dbe3a56e9498922ad5ba1edef ] Air Icy reported: UBSAN: Undefined behaviour in kernel/time/alarmtimer.c:811:7 signed integer overflow: 1529859276030040771 + 9223372036854775807 cannot be represented in type 'long long int' Call Trace: alarm_timer_nsleep+0x44c/0x510 kernel/time/alarmtimer.c:811 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1235 [inline] __se_sys_clock_nanosleep kernel/time/posix-timers.c:1213 [inline] __x64_sys_clock_nanosleep+0x326/0x4e0 kernel/time/posix-timers.c:1213 do_syscall_64+0xb8/0x3a0 arch/x86/entry/common.c:290 alarm_timer_nsleep() uses ktime_add() to add the current time and the relative expiry value. ktime_add() has no sanity checks so the addition can overflow when the relative timeout is large enough. Use ktime_add_safe() which has the necessary sanity checks in place and limits the result to the valid range. Fixes: 9a7adcf5c6de ("timers: Posix interface for alarm-timers") Reported-by: Team OWL337 Signed-off-by: Thomas Gleixner Cc: John Stultz Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1807020926360.1595@nanos.tec.linutronix.de Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

alarmtimer: don't rate limit one-shot timers

2017-07-27T22:08:08Z

Commit ff86bf0c65f1 ("alarmtimer: Rate limit periodic intervals") sets a minimum bound on the alarm timer interval. This minimum bound shouldn't be applied if the interval is 0. Otherwise, one-shot timers will be converted into periodic ones. Fixes: ff86bf0c65f1 ("alarmtimer: Rate limit periodic intervals") Reported-by: Ben Fennema Signed-off-by: Greg Hackmann Cc: stable@vger.kernel.org Cc: John Stultz Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

alarmtimer: Rate limit periodic intervals

2017-06-24T05:11:17Z

commit ff86bf0c65f14346bf2440534f9ba5ac232c39a0 upstream. The alarmtimer code has another source of potentially rearming itself too fast. Interval timers with a very samll interval have a similar CPU hog effect as the previously fixed overflow issue. The reason is that alarmtimers do not implement the normal protection against this kind of problem which the other posix timer use: timer expires -> queue signal -> deliver signal -> rearm timer This scheme brings the rearming under scheduler control and prevents permanently firing timers which hog the CPU. Bringing this scheme to the alarm timer code is a major overhaul because it lacks all the necessary mechanisms completely. So for a quick fix limit the interval to one jiffie. This is not problematic in practice as alarmtimers are usually backed by an RTC for suspend which have 1 second resolution. It could be therefor argued that the resolution of this clock should be set to 1 second in general, but that's outside the scope of this fix. Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: Kostya Serebryany Cc: syzkaller Cc: John Stultz Cc: Dmitry Vyukov Link: http://lkml.kernel.org/r/20170530211655.896767100@linutronix.de Signed-off-by: Greg Kroah-Hartman

alarmtimer: Prevent overflow of relative timers

2017-06-24T05:11:17Z

commit f4781e76f90df7aec400635d73ea4c35ee1d4765 upstream. Andrey reported a alartimer related RCU stall while fuzzing the kernel with syzkaller. The reason for this is an overflow in ktime_add() which brings the resulting time into negative space and causes immediate expiry of the timer. The following rearm with a small interval does not bring the timer back into positive space due to the same issue. This results in a permanent firing alarmtimer which hogs the CPU. Use ktime_add_safe() instead which detects the overflow and clamps the result to KTIME_SEC_MAX. Reported-by: Andrey Konovalov Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: Kostya Serebryany Cc: syzkaller Cc: John Stultz Cc: Dmitry Vyukov Link: http://lkml.kernel.org/r/20170530211655.802921648@linutronix.de Signed-off-by: Greg Kroah-Hartman

alarmtimer: Remove unused but set variable

2016-10-17T09:59:37Z

Remove the set but unused variable base in alarm_clock_get to fix the following warning when building with 'W=1': kernel/time/alarmtimer.c: In function ‘alarm_timer_create’: kernel/time/alarmtimer.c:545:21: warning: variable ‘base’ set but not used [-Wunused-but-set-variable] Signed-off-by: Tobias Klauser Cc: John Stultz Link: http://lkml.kernel.org/r/20161017094702.10873-1-tklauser@distanz.ch Signed-off-by: Thomas Gleixner

alarmtimer: Fix comments describing structure fields

2016-06-20T19:47:09Z

Updated struct alarm and struct alarm_timer descriptions. Cc: Prarit Bhargava Cc: Richard Cochran Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Pratyush Patel Signed-off-by: John Stultz

alarmtimer: Avoid unexpected rtc interrupt when system resume from S3

2015-12-04T06:31:42Z

Before the system go to suspend (S3), if user create a timer with clockid CLOCK_REALTIME_ALARM/CLOCK_BOOTTIME_ALARM and set a "large" timeout value to this timer. The function alarmtimer_suspend will be called to setup a timeout value to RTC timer to avoid the system sleep over time. However, if the system wakeup early than RTC timeout, the RTC timer will not be cleared. And this will cause the hpet_rtc_interrupt come unexpectedly until the RTC timeout. To fix this problem, just adding alarmtimer_resume to cancel the RTC timer. This was noticed because the HPET RTC emulation fires an interrupt every 16ms(=1/2^DEFAULT_RTC_SHIFT) up to the point where the alarm time is reached. This program always hits this situation (https://lkml.org/lkml/2015/11/8/326), if system wake up earlier than alarm time. Cc: Thomas Gleixner Cc: John Stultz Signed-off-by: Zhuo-hao Lee [jstultz: Tweak commit subject & formatting slightly] Signed-off-by: John Stultz

alarmtimer: Get rid of unused return value

2015-04-22T15:06:52Z

We want to get rid of the hrtimer_start() return value and the alarm timer return value is nowhere used. Remove it. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra Cc: Preeti U Murthy Cc: Viresh Kumar Cc: Marcelo Tosatti Cc: Frederic Weisbecker Cc: John Stultz Link: http://lkml.kernel.org/r/20150414203503.243910615@linutronix.de Signed-off-by: Thomas Gleixner