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BUG: KCSAN: data-race in snd_seq_timer_get_cur_tick / snd_seq_timer_interrupt

write to 0xffff8881208dacd8 of 4 bytes by interrupt on cpu 1:
 snd_seq_timer_update_tick sound/core/seq/seq_timer.h:58 [inline]
 snd_seq_timer_interrupt+0x202/0x280 sound/core/seq/seq_timer.c:150
 snd_timer_process_callbacks+0x1e4/0x220 sound/core/timer.c:757
 snd_timer_interrupt sound/core/timer.c:880 [inline]
 snd_timer_interrupt+0x483/0x930 sound/core/timer.c:801
 snd_hrtimer_callback+0x18f/0x260 sound/core/hrtimer.c:50
 __run_hrtimer kernel/time/hrtimer.c:1514 [inline]
 __hrtimer_run_queues+0x274/0x5f0 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
 __read_once_size+0x6/0xe0 include/linux/compiler.h:227
 compound_head include/linux/page-flags.h:174 [inline]
 PageSwapBacked include/linux/page-flags.h:340 [inline]
 mm_counter_file include/linux/mm.h:1664 [inline]
 mm_counter include/linux/mm.h:1673 [inline]
 copy_one_pte mm/memory.c:774 [inline]
 copy_pte_range mm/memory.c:823 [inline]
 copy_pmd_range mm/memory.c:874 [inline]
 copy_pud_range mm/memory.c:908 [inline]
 copy_p4d_range mm/memory.c:930 [inline]
 copy_page_range+0x1228/0x1a80 mm/memory.c:992
 dup_mmap kernel/fork.c:601 [inline]
 dup_mm+0x74a/0xba0 kernel/fork.c:1361
 copy_mm kernel/fork.c:1417 [inline]
 copy_process+0x36f3/0x3b50 kernel/fork.c:2012
 _do_fork+0xfe/0x6e0 kernel/fork.c:2366
 __do_sys_clone kernel/fork.c:2521 [inline]
 __se_sys_clone kernel/fork.c:2502 [inline]
 __x64_sys_clone+0x12b/0x160 kernel/fork.c:2502
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8881208dacd8 of 4 bytes by task 2505 on cpu 0:
 snd_seq_timer_get_cur_tick+0x21/0x40 sound/core/seq/seq_timer.c:449
 update_timestamp_of_queue+0x93/0x110 sound/core/seq/seq_clientmgr.c:586
 deliver_to_subscribers sound/core/seq/seq_clientmgr.c:691 [inline]
 snd_seq_deliver_event+0x2cd/0x4c0 sound/core/seq/seq_clientmgr.c:828
 snd_seq_kernel_client_dispatch+0xef/0x110 sound/core/seq/seq_clientmgr.c:2323
 snd_vmidi_output_work+0x156/0x200 sound/core/seq/seq_virmidi.c:149
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 2505 Comm: kworker/0:1H Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_highpri snd_vmidi_output_work
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