Messages in this thread Patch in this message | | | From | Tom Zanussi <> | Subject | [PATCH 08/13] hrtimer: Don't lose state in cpu_chill() | Date | Mon, 8 Apr 2019 14:14:10 -0500 |
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4.14.109-rt58-rc1 stable review patch. If anyone has any objections, please let me know.
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[ Upstream commit 585456236766349f692f9fbcc089d71411831f88 ]
In cpu_chill() the state is set to TASK_UNINTERRUPTIBLE and a timer is programmed. On return the state is always TASK_RUNNING which means we lose the state if it was something other than RUNNING. Also set_current_state() sets ->task_state_change to within cpu_chill() which is not expected.
Save the task state on entry and restore it on return. Simply set the state in order to avoid updating ->task_state_change.
Cc: stable-rt@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> --- kernel/time/hrtimer.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index c8d806126381..6da6b5dded3c 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -1866,15 +1866,18 @@ void cpu_chill(void) { ktime_t chill_time; unsigned int freeze_flag = current->flags & PF_NOFREEZE; + long saved_state; + saved_state = current->state; chill_time = ktime_set(0, NSEC_PER_MSEC); - set_current_state(TASK_UNINTERRUPTIBLE); + __set_current_state_no_track(TASK_UNINTERRUPTIBLE); current->flags |= PF_NOFREEZE; sleeping_lock_inc(); schedule_hrtimeout(&chill_time, HRTIMER_MODE_REL_HARD); sleeping_lock_dec(); if (!freeze_flag) current->flags &= ~PF_NOFREEZE; + __set_current_state_no_track(saved_state); } EXPORT_SYMBOL(cpu_chill); #endif -- 2.14.1
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