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[ Upstream commit 7a8e61f8478639072d402a26789055a4a4de8f77 ] Several people reported testing failures after setting CLOCK_REALTIME close to the limits of the kernel internal representation in nanoseconds, i.e. year 2262. The failures are exposed in subsequent operations, i.e. when arming timers or when the advancing CLOCK_MONOTONIC makes the calculation of CLOCK_REALTIME overflow into negative space. Now people start to paper over the underlying problem by clamping calculations to the valid range, but that's just wrong because such workarounds will prevent detection of real issues as well. It is reasonable to force an upper bound for the various methods of setting CLOCK_REALTIME. Year 2262 is the absolute upper bound. Assume a maximum uptime of 30 years which is plenty enough even for esoteric embedded systems. That results in an upper bound of year 2232 for setting the time. Once that limit is reached in reality this limit is only a small part of the problem space. But until then this stops people from trying to paper over the problem at the wrong places. Reported-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Reported-by: Hongbo Yao <yaohongbo@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Miroslav Lichvar <mlichvar@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1903231125480.2157@nanos.tec.linutronix.de Signed-off-by: Sasha Levin <sashal@kernel.org> |
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| .. | ||
| alarmtimer.c | ||
| clockevents.c | ||
| clocksource.c | ||
| hrtimer.c | ||
| itimer.c | ||
| jiffies.c | ||
| Kconfig | ||
| Makefile | ||
| ntp.c | ||
| ntp_internal.h | ||
| posix-clock.c | ||
| posix-cpu-timers.c | ||
| posix-stubs.c | ||
| posix-timers.c | ||
| posix-timers.h | ||
| sched_clock.c | ||
| test_udelay.c | ||
| tick-broadcast-hrtimer.c | ||
| tick-broadcast.c | ||
| tick-common.c | ||
| tick-internal.h | ||
| tick-oneshot.c | ||
| tick-sched.c | ||
| tick-sched.h | ||
| time.c | ||
| timeconst.bc | ||
| timeconv.c | ||
| timecounter.c | ||
| timekeeping.c | ||
| timekeeping.h | ||
| timekeeping_debug.c | ||
| timekeeping_internal.h | ||
| timer.c | ||
| timer_list.c | ||