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BUG: KCSAN: data-race in probe_sched_switch / tracing_start_sched_switch

write to 0xffffffff896001e0 of 4 bytes by task 19161 on cpu 0:
 tracing_start_sched_switch+0x8d/0x200 kernel/trace/trace_sched_switch.c:101
 tracing_start_cmdline_record+0x13/0x20 kernel/trace/trace_sched_switch.c:135
 __ftrace_event_enable_disable+0x203/0x4b0 kernel/trace/trace_events.c:894
 ftrace_event_enable_disable kernel/trace/trace_events.c:934 [inline]
 __ftrace_set_clr_event_nolock+0x39e/0x820 kernel/trace/trace_events.c:1404
 __ftrace_set_clr_event kernel/trace/trace_events.c:1437 [inline]
 ftrace_set_clr_event+0x2a6/0x340 kernel/trace/trace_events.c:1487
 ftrace_event_write+0x170/0x1d0 kernel/trace/trace_events.c:1577
 vfs_write+0x254/0x9a0 fs/read_write.c:685
 ksys_write+0xdc/0x1a0 fs/read_write.c:739
 __do_sys_write fs/read_write.c:750 [inline]
 __se_sys_write fs/read_write.c:747 [inline]
 __x64_sys_write+0x40/0x50 fs/read_write.c:747
 x64_sys_call+0x154e/0x2550 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff896001e0 of 4 bytes by task 0 on cpu 1:
 probe_sched_switch+0x46/0xa0 kernel/trace/trace_sched_switch.c:32
 __traceiter_sched_switch+0x3f/0x60 include/trace/events/sched.h:220
 __do_trace_sched_switch include/trace/events/sched.h:220 [inline]
 trace_sched_switch include/trace/events/sched.h:220 [inline]
 __schedule+0xc34/0xd20 kernel/sched/core.c:7281
 schedule_idle+0x1d/0x40 kernel/sched/core.c:7402
 do_idle+0x27e/0x2d0 kernel/sched/idle.c:384
 cpu_startup_entry+0x24/0x30 kernel/sched/idle.c:454
 start_secondary+0x95/0xa0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x157

value changed: 0x0000009b -> 0x0000009c

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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