syzbot

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BUG: KCSAN: data-race in __tmigr_cpu_activate / tmigr_update_events

write to 0xffff888237c205dc of 1 bytes by task 0 on cpu 0:
 __tmigr_cpu_activate+0x55/0x200 kernel/time/timer_migration.c:676
 tmigr_cpu_activate+0x8a/0xc0 kernel/time/timer_migration.c:699
 timer_clear_idle+0x28/0x100 kernel/time/timer.c:2381
 tick_nohz_restart_sched_tick+0x22/0x110 kernel/time/tick-sched.c:1101
 tick_nohz_idle_update_tick kernel/time/tick-sched.c:1432 [inline]
 tick_nohz_idle_exit+0xfe/0x1d0 kernel/time/tick-sched.c:1475
 do_idle+0x1ee/0x230 kernel/sched/idle.c:339
 cpu_startup_entry+0x25/0x30 kernel/sched/idle.c:424
 rest_init+0xef/0xf0 init/main.c:747
 start_kernel+0x586/0x5e0 init/main.c:1105
 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507
 x86_64_start_kernel+0x9a/0xa0 arch/x86/kernel/head64.c:488
 common_startup_64+0x12c/0x137

read to 0xffff888237c205dc of 1 bytes by task 0 on cpu 1:
 tmigr_next_groupevt kernel/time/timer_migration.c:567 [inline]
 tmigr_next_groupevt_expires kernel/time/timer_migration.c:609 [inline]
 tmigr_update_events+0x41d/0x5d0 kernel/time/timer_migration.c:840
 tmigr_inactive_up kernel/time/timer_migration.c:1302 [inline]
 __walk_groups kernel/time/timer_migration.c:533 [inline]
 walk_groups kernel/time/timer_migration.c:546 [inline]
 __tmigr_cpu_deactivate+0x2b1/0x410 kernel/time/timer_migration.c:1322
 tmigr_cpu_deactivate+0x66/0x180 kernel/time/timer_migration.c:1346
 timer_use_tmigr kernel/time/timer.c:2194 [inline]
 __get_next_timer_interrupt+0x137/0x530 kernel/time/timer.c:2269
 timer_base_try_to_set_idle+0x54/0x60 kernel/time/timer.c:2358
 tick_nohz_stop_tick kernel/time/tick-sched.c:993 [inline]
 tick_nohz_idle_stop_tick+0x15b/0x650 kernel/time/tick-sched.c:1232
 cpuidle_idle_call kernel/sched/idle.c:226 [inline]
 do_idle+0x178/0x230 kernel/sched/idle.c:326
 cpu_startup_entry+0x25/0x30 kernel/sched/idle.c:424
 start_secondary+0x96/0xa0 arch/x86/kernel/smpboot.c:314
 common_startup_64+0x12c/0x137

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.12.0-syzkaller-00171-g23acd177540d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
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