syzbot

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BUG: KCSAN: data-race in tick_nohz_stop_tick / tick_nohz_stop_tick

write to 0xffffffff87bb65e0 of 4 bytes by task 0 on cpu 0:
 tick_nohz_stop_tick+0x99/0x420 kernel/time/tick-sched.c:837
 __tick_nohz_idle_stop_tick kernel/time/tick-sched.c:1022 [inline]
 tick_nohz_idle_stop_tick+0x15d/0x310 kernel/time/tick-sched.c:1043
 cpuidle_idle_call kernel/sched/idle.c:235 [inline]
 do_idle+0x176/0x230 kernel/sched/idle.c:300
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:397
 rest_init+0xd7/0xe0 init/main.c:721
 arch_call_rest_init+0xa/0xb
 start_kernel+0x5a1/0x626 init/main.c:1064
 secondary_startup_64_no_verify+0xb0/0xbb

read to 0xffffffff87bb65e0 of 4 bytes by task 0 on cpu 1:
 tick_nohz_stop_tick+0x73/0x420 kernel/time/tick-sched.c:836
 __tick_nohz_idle_stop_tick kernel/time/tick-sched.c:1022 [inline]
 tick_nohz_idle_stop_tick+0x15d/0x310 kernel/time/tick-sched.c:1043
 cpuidle_idle_call kernel/sched/idle.c:235 [inline]
 do_idle+0x176/0x230 kernel/sched/idle.c:300
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:397
 secondary_startup_64_no_verify+0xb0/0xbb

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.12.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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