syzbot

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BUG: KCSAN: data-race in hrtimer_interrupt / print_tickdevice

write to 0xffff888237c1aed8 of 8 bytes by interrupt on cpu 0:
 hrtimer_interrupt+0xa7/0xa70 kernel/time/hrtimer.c:1790
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
 __sysvec_apic_timer_interrupt+0xa3/0x250 arch/x86/kernel/apic/apic.c:1112
 sysvec_apic_timer_interrupt+0x88/0xb0 arch/x86/kernel/apic/apic.c:1106
 asm_sysvec_apic_timer_interrupt+0x16/0x20
 check_kcov_mode kernel/kcov.c:168 [inline]
 __sanitizer_cov_trace_pc+0x33/0x60 kernel/kcov.c:200
 process_output_block drivers/tty/n_tty.c:546 [inline]
 n_tty_write+0x755/0xb40 drivers/tty/n_tty.c:2297
 do_tty_write drivers/tty/tty_io.c:1024 [inline]
 file_tty_write+0x3f9/0x650 drivers/tty/tty_io.c:1095
 tty_write+0x24/0x30 drivers/tty/tty_io.c:1116
 do_iter_readv_writev+0x27b/0x300
 do_iter_write+0x16f/0x5c0 fs/read_write.c:868
 vfs_iter_write+0x4c/0x70 fs/read_write.c:909
 iter_file_splice_write+0x44a/0x7c0 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:936
 splice_direct_to_actor+0x345/0x660 fs/splice.c:891
 do_splice_direct+0xfb/0x180 fs/splice.c:979
 do_sendfile+0x3ad/0x900 fs/read_write.c:1262
 __do_sys_sendfile64 fs/read_write.c:1327 [inline]
 __se_sys_sendfile64 fs/read_write.c:1313 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1313
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888237c1aed8 of 8 bytes by task 18940 on cpu 1:
 print_tickdevice+0x158/0x370 kernel/time/timer_list.c:204
 timer_list_show+0x74/0x180 kernel/time/timer_list.c:296
 seq_read_iter+0x676/0x8e0 fs/seq_file.c:272
 proc_reg_read_iter+0xfa/0x170 fs/proc/inode.c:300
 call_read_iter include/linux/fs.h:2052 [inline]
 generic_file_splice_read+0x1de/0x2c0 fs/splice.c:311
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x2ac/0x660 fs/splice.c:870
 do_splice_direct+0xfb/0x180 fs/splice.c:979
 do_sendfile+0x3ad/0x900 fs/read_write.c:1262
 __do_sys_sendfile64 fs/read_write.c:1327 [inline]
 __se_sys_sendfile64 fs/read_write.c:1313 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1313
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000004ee26c80a8 -> 0x7fffffffffffffff

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 18940 Comm: syz-executor.3 Not tainted 5.19.0-rc7-syzkaller-00190-g70664fc10c0d-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
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