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BUG: KCSAN: data-race in hrtimer_interrupt / print_cpu

write to 0xffff88812c11fce0 of 8 bytes by interrupt on cpu 1:
 hrtimer_interrupt+0x1b2/0x490 kernel/time/hrtimer.c:1633
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1119 [inline]
 smp_apic_timer_interrupt+0xd8/0x270 arch/x86/kernel/apic/apic.c:1144
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 find_watchpoint kernel/kcsan/core.c:126 [inline]
 check_access kernel/kcsan/core.c:545 [inline]
 __tsan_read8+0x61/0x100 kernel/kcsan/core.c:694
 ext4_set_iomap+0x18d/0x3c0 fs/ext4/inode.c:3331
 ext4_iomap_begin+0x3dc/0x4a0 fs/ext4/inode.c:3447
 iomap_apply+0xd4/0x660 fs/iomap/apply.c:46
 iomap_dio_rw+0x67e/0x9a0 fs/iomap/direct-io.c:498
 ext4_dio_write_iter fs/ext4/file.c:532 [inline]
 ext4_file_write_iter+0xb84/0xd30 fs/ext4/file.c:640
 call_write_iter include/linux/fs.h:1901 [inline]
 new_sync_write+0x303/0x400 fs/read_write.c:483
 __vfs_write+0x9e/0xb0 fs/read_write.c:496
 vfs_write fs/read_write.c:558 [inline]
 vfs_write+0x189/0x380 fs/read_write.c:542
 ksys_write+0xc5/0x1a0 fs/read_write.c:611
 __do_sys_write fs/read_write.c:623 [inline]
 __se_sys_write fs/read_write.c:620 [inline]
 __x64_sys_write+0x49/0x60 fs/read_write.c:620
 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88812c11fce0 of 8 bytes by task 8240 on cpu 0:
 print_cpu+0x22c/0x670 kernel/time/timer_list.c:148
 timer_list_show+0xb5/0x140 kernel/time/timer_list.c:311
 seq_read+0x7b3/0x9d0 fs/seq_file.c:268
 proc_reg_read+0xe8/0x140 fs/proc/inode.c:223
 do_loop_readv_writev fs/read_write.c:714 [inline]
 do_loop_readv_writev fs/read_write.c:701 [inline]
 do_iter_read+0x33d/0x3a0 fs/read_write.c:935
 vfs_readv+0x9c/0xf0 fs/read_write.c:1053
 kernel_readv fs/splice.c:365 [inline]
 default_file_splice_read+0x361/0x590 fs/splice.c:422
 do_splice_to+0xc7/0x100 fs/splice.c:892
 splice_direct_to_actor+0x1b9/0x540 fs/splice.c:971
 do_splice_direct+0x152/0x1d0 fs/splice.c:1080
 do_sendfile+0x396/0x810 fs/read_write.c:1520
 __do_sys_sendfile64 fs/read_write.c:1581 [inline]
 __se_sys_sendfile64 fs/read_write.c:1567 [inline]
 __x64_sys_sendfile64+0x121/0x140 fs/read_write.c:1567
 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8240 Comm: syz-executor.1 Not tainted 5.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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