WSL2-Linux-Kernel/kernel/sched
Peter Zijlstra 668a1f5e75 sched: Fix balance_push() vs __sched_setscheduler()
[ Upstream commit 04193d590b ]

The purpose of balance_push() is to act as a filter on task selection
in the case of CPU hotplug, specifically when taking the CPU out.

It does this by (ab)using the balance callback infrastructure, with
the express purpose of keeping all the unlikely/odd cases in a single
place.

In order to serve its purpose, the balance_push_callback needs to be
(exclusively) on the callback list at all times (noting that the
callback always places itself back on the list the moment it runs,
also noting that when the CPU goes down, regular balancing concerns
are moot, so ignoring them is fine).

And here-in lies the problem, __sched_setscheduler()'s use of
splice_balance_callbacks() takes the callbacks off the list across a
lock-break, making it possible for, an interleaving, __schedule() to
see an empty list and not get filtered.

Fixes: ae79270232 ("sched: Optimize finish_lock_switch()")
Reported-by: Jing-Ting Wu <jing-ting.wu@mediatek.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Jing-Ting Wu <jing-ting.wu@mediatek.com>
Link: https://lkml.kernel.org/r/20220519134706.GH2578@worktop.programming.kicks-ass.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-22 14:22:02 +02:00
..
Makefile sched: Trivial core scheduling cookie management 2021-05-12 11:43:31 +02:00
autogroup.c sched/fair: Prevent dead task groups from regaining cfs_rq's 2021-11-25 09:48:32 +01:00
autogroup.h
clock.c sched: Fix various typos 2021-03-22 00:11:52 +01:00
completion.c
core.c sched: Fix balance_push() vs __sched_setscheduler() 2022-06-22 14:22:02 +02:00
core_sched.c sched: prctl() core-scheduling interface 2021-05-12 11:43:31 +02:00
cpuacct.c sched/cpuacct: Fix charge percpu cpuusage 2022-04-08 14:23:11 +02:00
cpudeadline.c sched,rt: Use the full cpumask for balancing 2020-11-10 18:39:00 +01:00
cpudeadline.h
cpufreq.c
cpufreq_schedutil.c sched/uclamp: Fix iowait boost escaping uclamp restriction 2022-04-08 14:23:10 +02:00
cpupri.c sched: Fix various typos 2021-03-22 00:11:52 +01:00
cpupri.h sched/cpupri: Add CPUPRI_HIGHER 2020-10-29 11:00:30 +01:00
cputime.c cputime, cpuacct: Include guest time in user time in cpuacct.stat 2022-01-27 11:05:09 +01:00
deadline.c sched/core: Avoid obvious double update_rq_clock warning 2022-06-09 10:22:36 +02:00
debug.c sched/debug: Remove mpol_get/put and task_lock/unlock from sched_show_numa 2022-04-08 14:23:10 +02:00
fair.c sched/fair: Fix cfs_rq_clock_pelt() for throttled cfs_rq 2022-06-09 10:22:48 +02:00
features.h sched: Warn on long periods of pending need_resched 2021-04-21 13:55:41 +02:00
idle.c sched/idle: Make the idle timer expire in hard interrupt context 2021-09-09 10:36:16 +02:00
isolation.c sched/isolation: Reconcile rcu_nocbs= and nohz_full= 2021-05-13 14:12:47 +02:00
loadavg.c sched: Make multiple runqueue task counters 32-bit 2021-05-12 21:34:17 +02:00
membarrier.c sched/membarrier: Fix membarrier-rseq fence command missing from query bitmask 2022-02-01 17:27:05 +01:00
pelt.c sched: Fix various typos 2021-03-22 00:11:52 +01:00
pelt.h sched/fair: Fix cfs_rq_clock_pelt() for throttled cfs_rq 2022-06-09 10:22:48 +02:00
psi.c sched/psi: report zeroes for CPU full at the system level 2022-06-09 10:22:48 +02:00
rt.c sched/core: Avoid obvious double update_rq_clock warning 2022-06-09 10:22:36 +02:00
sched-pelt.h
sched.h sched: Fix balance_push() vs __sched_setscheduler() 2022-06-22 14:22:02 +02:00
smp.h
stats.c sched: Fix various typos 2021-03-22 00:11:52 +01:00
stats.h psi: Fix PSI_MEM_FULL state when tasks are in memstall and doing reclaim 2022-01-27 11:04:27 +01:00
stop_task.c sched: Introduce sched_class::pick_task() 2021-05-12 11:43:28 +02:00
swait.c
topology.c sched/topology: Skip updating masks for non-online nodes 2021-08-20 12:32:57 +02:00
wait.c wait: add wake_up_pollfree() 2021-12-14 10:57:15 +01:00
wait_bit.c