================================================================== BUG: KCSAN: data-race in perf_event_update_userpage / perf_event_update_userpage write to 0xffff8881219fe018 of 8 bytes by task 13181 on cpu 0: perf_event_update_userpage+0x21a/0x340 kernel/events/core.c:5499 cpu_clock_event_add+0x3d/0x60 kernel/events/core.c:9911 event_sched_in.isra.0.part.0+0x1d5/0x560 kernel/events/core.c:2382 event_sched_in kernel/events/core.c:2354 [inline] group_sched_in+0xd1/0x2c0 kernel/events/core.c:2418 flexible_sched_in kernel/events/core.c:3463 [inline] flexible_sched_in+0x3a1/0x540 kernel/events/core.c:3452 visit_groups_merge+0x1d9/0x320 kernel/events/core.c:3411 ctx_flexible_sched_in kernel/events/core.c:3500 [inline] ctx_sched_in+0x1b4/0x360 kernel/events/core.c:3545 perf_event_sched_in+0x77/0xb0 kernel/events/core.c:2527 perf_event_context_sched_in kernel/events/core.c:3585 [inline] __perf_event_task_sched_in+0x354/0x390 kernel/events/core.c:3624 perf_event_task_sched_in include/linux/perf_event.h:1179 [inline] finish_task_switch+0x104/0x260 kernel/sched/core.c:3222 context_switch kernel/sched/core.c:3388 [inline] __schedule+0x30e/0x690 kernel/sched/core.c:4081 preempt_schedule_common+0x37/0x90 kernel/sched/core.c:4236 preempt_schedule+0x30/0x40 kernel/sched/core.c:4261 ___preempt_schedule+0x16/0x18 arch/x86/entry/thunk_64.S:50 try_to_wake_up+0x3dc/0x6e0 kernel/sched/core.c:2650 wake_up_process kernel/sched/core.c:2668 [inline] wake_up_q+0x5b/0xa0 kernel/sched/core.c:496 futex_wake+0x322/0x350 kernel/futex.c:1696 do_futex+0x2be/0x18d0 kernel/futex.c:3886 __do_sys_futex kernel/futex.c:3942 [inline] __se_sys_futex kernel/futex.c:3910 [inline] __x64_sys_futex+0x2cd/0x3f0 kernel/futex.c:3910 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 write to 0xffff8881219fe018 of 8 bytes by task 13182 on cpu 1: perf_event_update_userpage+0x21a/0x340 kernel/events/core.c:5499 perf_mmap+0xe06/0xf00 kernel/events/core.c:5962 call_mmap include/linux/fs.h:1907 [inline] mmap_region+0x7df/0xd50 mm/mmap.c:1784 do_mmap+0x6c8/0xba0 mm/mmap.c:1555 do_mmap_pgoff include/linux/mm.h:2338 [inline] vm_mmap_pgoff+0x12d/0x190 mm/util.c:506 ksys_mmap_pgoff+0x2d8/0x420 mm/mmap.c:1607 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline] __x64_sys_mmap+0x2e/0x40 arch/x86/kernel/sys_x86_64.c:91 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 13182 Comm: syz-executor.1 Not tainted 5.5.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================