hrtimer: Select housekeeping CPU during migration

[ Upstream commit 56c2cb10120894be40c40a9bf0ce798da14c50f6 ]

During CPU-down hotplug, hrtimers may migrate to isolated CPUs,
compromising CPU isolation.

Address this issue by masking valid CPUs for hrtimers using
housekeeping_cpumask(HK_TYPE_TIMER).

Suggested-by: Waiman Long <longman@redhat.com>
Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Waiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/20240222200856.569036-1-costa.shul@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Costa Shulyupin
2024-02-22 22:08:56 +02:00
committed by Greg Kroah-Hartman
parent 72ba377413
commit 748fb68e11

View File

@@ -38,6 +38,7 @@
#include <linux/sched/deadline.h>
#include <linux/sched/nohz.h>
#include <linux/sched/debug.h>
#include <linux/sched/isolation.h>
#include <linux/timer.h>
#include <linux/freezer.h>
#include <linux/compat.h>
@@ -2220,8 +2221,8 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
int hrtimers_cpu_dying(unsigned int dying_cpu)
{
int i, ncpu = cpumask_any_and(cpu_active_mask, housekeeping_cpumask(HK_TYPE_TIMER));
struct hrtimer_cpu_base *old_base, *new_base;
int i, ncpu = cpumask_first(cpu_active_mask);
tick_cancel_sched_timer(dying_cpu);