tick/common: Align tick period during sched_timer setup
stable inclusion from stable-v5.10.186 commit 3cc7935d32212f6252442c5ce0e1a1c81e466319 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8L5XP Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3cc7935d32212f6252442c5ce0e1a1c81e466319 -------------------------------- commit 13bb06f8 upstream. The tick period is aligned very early while the first clock_event_device is registered. At that point the system runs in periodic mode and switches later to one-shot mode if possible. The next wake-up event is programmed based on the aligned value (tick_next_period) but the delta value, that is used to program the clock_event_device, is computed based on ktime_get(). With the subtracted offset, the device fires earlier than the exact time frame. With a large enough offset the system programs the timer for the next wake-up and the remaining time left is too small to make any boot progress. The system hangs. Move the alignment later to the setup of tick_sched timer. At this point the system switches to oneshot mode and a high resolution clocksource is available. At this point it is safe to align tick_next_period because ktime_get() will now return accurate (not jiffies based) time. [bigeasy: Patch description + testing]. Fixes: e9523a0d ("tick/common: Align tick period with the HZ tick.") Reported-by:Mathias Krause <minipli@grsecurity.net> Reported-by:
"Bhatnagar, Rishabh" <risbhat@amazon.com> Suggested-by:
Mathias Krause <minipli@grsecurity.net> Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Tested-by:
Richard W.M. Jones <rjones@redhat.com> Tested-by:
Mathias Krause <minipli@grsecurity.net> Acked-by:
SeongJae Park <sj@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/5a56290d-806e-b9a5-f37c-f21958b5a8c0@grsecurity.net Link: https://lore.kernel.org/12c6f9a3-d087-b824-0d05-0d18c9bc1bf3@amazon.com Link: https://lore.kernel.org/r/20230615091830.RxMV2xf_@linutronix.de Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
sanglipeng <sanglipeng1@jd.com>
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