==================================================================
BUG: KCSAN: data-race in hrtimer_interrupt / print_cpu

write to 0xffff88812c11ec20 of 8 bytes by interrupt on cpu 1:
 hrtimer_interrupt+0x7c5/0xa40 kernel/time/hrtimer.c:1654
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline]
 __sysvec_apic_timer_interrupt+0xa3/0x280 arch/x86/kernel/apic/apic.c:1097
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xf0 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:596
 arch_local_irq_enable arch/x86/include/asm/paravirt.h:775 [inline]
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline]
 _raw_spin_unlock_irq+0x41/0x70 kernel/locking/spinlock.c:199
 finish_lock_switch kernel/sched/core.c:3169 [inline]
 finish_task_switch+0x8b/0x270 kernel/sched/core.c:3269
 context_switch kernel/sched/core.c:3433 [inline]
 __schedule+0x395/0x560 kernel/sched/core.c:4155
 schedule+0x91/0xd0 kernel/sched/core.c:4230
 io_schedule+0x3b/0x50 kernel/sched/core.c:5873
 wait_on_page_bit_common+0x458/0x710 mm/filemap.c:1150
 wait_on_page_bit_killable mm/filemap.c:1206 [inline]
 wait_on_page_locked_killable include/linux/pagemap.h:575 [inline]
 generic_file_buffered_read+0x3fe/0x1750 mm/filemap.c:2056
 generic_file_read_iter+0x7d/0x3e0 mm/filemap.c:2307
 ext4_file_read_iter+0x2dd/0x410 fs/ext4/file.c:73
 call_read_iter include/linux/fs.h:1901 [inline]
 generic_file_splice_read+0x22a/0x310 fs/splice.c:312
 do_splice_to fs/splice.c:870 [inline]
 splice_direct_to_actor+0x2a8/0x660 fs/splice.c:950
 do_splice_direct+0xf2/0x170 fs/splice.c:1059
 do_sendfile+0x562/0xb10 fs/read_write.c:1521
 __do_sys_sendfile64 fs/read_write.c:1582 [inline]
 __se_sys_sendfile64 fs/read_write.c:1568 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1568
 do_syscall_64+0x71/0x120 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88812c11ec20 of 8 bytes by task 15409 on cpu 0:
 print_cpu+0x479/0x7f0 kernel/time/timer_list.c:148
 timer_list_show+0x114/0x180 kernel/time/timer_list.c:311
 seq_read+0x2ee/0x900 fs/seq_file.c:208
 pde_read fs/proc/inode.c:306 [inline]
 proc_reg_read+0x116/0x1a0 fs/proc/inode.c:318
 do_loop_readv_writev fs/read_write.c:715 [inline]
 do_iter_read+0x2fe/0x480 fs/read_write.c:936
 vfs_readv+0xa0/0xe0 fs/read_write.c:1054
 kernel_readv fs/splice.c:355 [inline]
 default_file_splice_read+0x3c6/0x630 fs/splice.c:412
 do_splice_to fs/splice.c:871 [inline]
 splice_direct_to_actor+0x2c7/0x660 fs/splice.c:950
 do_splice_direct+0xf2/0x170 fs/splice.c:1059
 do_sendfile+0x562/0xb10 fs/read_write.c:1521
 __do_sys_sendfile64 fs/read_write.c:1582 [inline]
 __se_sys_sendfile64 fs/read_write.c:1568 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1568
 do_syscall_64+0x71/0x120 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 15409 Comm: syz-executor.0 Not tainted 5.8.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================