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BUG: KCSAN: data-race in ktime_get_real_seconds / timekeeping_advance

write to 0xffffffff86040b08 of 280 bytes by interrupt on cpu 0:
 timekeeping_advance+0x893/0xd80 include/linux/string.h:378
 update_wall_time+0x19/0x20 kernel/time/timekeeping.c:2137
 tick_do_update_jiffies64+0x1ae/0x260 kernel/time/tick-sched.c:94
 tick_sched_do_timer+0xd4/0xe0 kernel/time/tick-sched.c:138
 tick_sched_timer+0x43/0xe0 kernel/time/tick-sched.c:1292
 __run_hrtimer kernel/time/hrtimer.c:1514 [inline]
 __hrtimer_run_queues+0x288/0x600 kernel/time/hrtimer.c:1576
 hrtimer_interrupt+0x22a/0x480 kernel/time/hrtimer.c:1638
 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
 __kcsan_setup_watchpoint+0x15/0x4a0 kernel/kcsan/core.c:295
 __tsan_read1 kernel/kcsan/kcsan.c:33 [inline]
 __tsan_read1+0x2c/0x30 kernel/kcsan/kcsan.c:33
 strlen+0x31/0x60 lib/string.c:527
 strlen include/linux/string.h:300 [inline]
 insert_entry fs/proc/proc_sysctl.c:161 [inline]
 insert_header+0x272/0x820 fs/proc/proc_sysctl.c:237
 __register_sysctl_table+0x538/0x880 fs/proc/proc_sysctl.c:1366

read to 0xffffffff86040b78 of 8 bytes by task 7290 on cpu 1:
 ktime_get_real_seconds+0x20/0x40 kernel/time/timekeeping.c:127
 tomoyo_update_stat security/tomoyo/common.c:2341 [inline]
 tomoyo_add_entry security/tomoyo/common.c:2042 [inline]
 tomoyo_supervisor+0xcde/0xd20 security/tomoyo/common.c:2101
 tomoyo_audit_path_number_log security/tomoyo/file.c:235 [inline]
 tomoyo_path_number_perm+0x323/0x3c0 security/tomoyo/file.c:734
 tomoyo_file_ioctl+0x2c/0x40 security/tomoyo/tomoyo.c:335
 security_file_ioctl+0x6d/0xa0 security/security.c:1409
 ksys_ioctl+0x64/0xe0 fs/ioctl.c:711
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x4c/0x60 fs/ioctl.c:718
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7290 Comm: syz-executor.0 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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