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BUG: KCSAN: data-race in tick_nohz_idle_stop_tick / tick_sched_do_timer

read to 0xffffffff85caf2d0 of 4 bytes by interrupt on cpu 0:
 tick_sched_do_timer+0x33/0xe0 kernel/time/tick-sched.c:128
 tick_sched_timer+0x43/0xe0 kernel/time/tick-sched.c:1289
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x288/0x600 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x22a/0x480 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0xdc/0x280 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
 arch_local_irq_restore arch/x86/include/asm/paravirt.h:768 [inline]
 __kcsan_setup_watchpoint+0x272/0x500 kernel/kcsan/core.c:470
 __tsan_read8 kernel/kcsan/kcsan.c:31 [inline]
 __tsan_read8+0x2c/0x30 kernel/kcsan/kcsan.c:31
 __should_failslab+0x29/0x130 mm/failslab.c:20
 should_failslab+0x9/0x14 mm/slab_common.c:1740
 slab_pre_alloc_hook mm/slab.h:503 [inline]
 slab_alloc_node mm/slab.c:3226 [inline]
 kmem_cache_alloc_node+0x39/0x660 mm/slab.c:3574
 __alloc_skb+0x8e/0x350 net/core/skbuff.c:197
 alloc_skb include/linux/skbuff.h:1055 [inline]
 __tcp_send_ack+0x7e/0x300 net/ipv4/tcp_output.c:3664
 tcp_send_ack+0x34/0x40 net/ipv4/tcp_output.c:3691

write to 0xffffffff85caf2d0 of 4 bytes by task 0 on cpu 1:
 tick_nohz_stop_tick kernel/time/tick-sched.c:758 [inline]
 __tick_nohz_idle_stop_tick kernel/time/tick-sched.c:949 [inline]
 tick_nohz_idle_stop_tick+0x525/0x670 kernel/time/tick-sched.c:970
 cpuidle_idle_call kernel/sched/idle.c:151 [inline]
 do_idle+0x1e0/0x2c0 kernel/sched/idle.c:263
 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:354
 start_secondary+0x207/0x260 arch/x86/kernel/smpboot.c:264
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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