perf: perf_fuzzer WARNING: ring_buffer.c:546 __rb_free_aux

[Vince Weaver]

I thought we had sorted all the AUX issues, though interestingly this is 
on a core2 system.

this is:

	static void __rb_free_aux(struct ring_buffer *rb)
	{

        /*
         * Should never happen, the last reference should be dropped from
         * perf_mmap_close() path, which first stops aux transactions (which
         * in turn are the atomic holders of aux_refcount) and then does the
         * last rb_free_aux().
         */
        WARN_ON_ONCE(in_atomic());


[87078.464463] WARNING: CPU: 1 PID: 19400 at kernel/events/ring_buffer.c:546 __rb_free_aux+0x40/0xe8
[87078.464466] CPU: 1 PID: 19400 Comm: perf_fuzzer Tainted: G        W       4.8.0+ #209
[87078.464467] Hardware name: AOpen   DE7000/nMCP7ALPx-DE R1.06 Oct.19.2012, BIOS 080015  10/19/2012
[87078.464468]  ffff88011fc85b00c ffffffff812bc679c 0000000000000000c 0000000000000000c
[87078.464469]  ffff88011fc85b40c ffffffff8104e0c8c 000002221fc85b98c ffff880119bf2700c
[87078.464470]  ffff880119bf2700c 0000000000000000c 0000000000000001c 0000000000006108c
[87078.464470] Call Trace:
[87078.464471]  <NMI>  [<ffffffff812bc679>] dump_stack+0x4d/0x63
[87078.464472]  [<ffffffff8104e0c8>] __warn+0xca/0xe5
[87078.464473]  [<ffffffff8104e19f>] warn_slowpath_null+0x1d/0x1f
[87078.464473]  [<ffffffff810fa055>] __rb_free_aux+0x40/0xe8
[87078.464474]  [<ffffffff810fab48>] rb_free_aux+0x18/0x1a
[87078.464475]  [<ffffffff810fad83>] perf_aux_output_end+0xca/0xd9
[87078.464475]  [<ffffffff81009890>] intel_bts_interrupt+0xc4/0x11f
[87078.464476]  [<ffffffff8100868c>] intel_pmu_handle_irq+0x75/0x3db
[87078.464477]  [<ffffffff8158e910>] ? reboot_interrupt+0x90/0x90
[87078.464478]  [<ffffffff810f93db>] ? perf_trace_run_bpf_submit+0x7b/0x8c
[87078.464479]  [<ffffffff810f93db>] ? perf_trace_run_bpf_submit+0x7b/0x8c
[87078.464479]  [<ffffffff81035a30>] ? __default_send_IPI_shortcut+0x39/0x40
[87078.464480]  [<ffffffff81002ecd>] perf_event_nmi_handler+0x2c/0x45
[87078.464481]  [<ffffffff810e72e7>] ? irq_work_queue+0x61/0x6d
[87078.464482]  [<ffffffff8101ee54>] ? native_sched_clock+0x1f/0x3a
[87078.464482]  [<ffffffff8101ee54>] ? native_sched_clock+0x1f/0x3a
[87078.464483]  [<ffffffff81002ecd>] ? perf_event_nmi_handler+0x2c/0x45
[87078.464484]  [<ffffffff8101a9a7>] nmi_handle+0x54/0xfa
[87078.464485]  [<ffffffff81036903>] ? nmi_raise_cpu_backtrace+0x1d/0x1d
[87078.464485]  [<ffffffff8101ac14>] default_do_nmi+0x47/0xe0
[87078.464486]  [<ffffffff8101ad45>] do_nmi+0x98/0x10b
[87078.464487]  [<ffffffff8158fd27>] end_repeat_nmi+0x1a/0x1e
[87078.464488]  [<ffffffff81073dbc>] ? can_migrate_task+0x11c/0x11c
[87078.464488]  [<ffffffff81073dbc>] ? can_migrate_task+0x11c/0x11c
[87078.464489]  [<ffffffff81073dbc>] ? can_migrate_task+0x11c/0x11c
[87078.464490]  <EOE>  <IRQ>  [<ffffffff81076439>] ? enqueue_task_fair+0x3f5/0x46b
[87078.464491]  [<ffffffff8106dcaa>] enqueue_task+0x4f/0x54
[87078.464491]  [<ffffffff8106dcaa>] ? enqueue_task+0x4f/0x54
[87078.464492]  [<ffffffff8106e1e9>] activate_task+0x2c/0x2e
[87078.464493]  [<ffffffff8106e3f0>] ttwu_do_activate+0x43/0x75
[87078.464494]  [<ffffffff8106f1dd>] try_to_wake_up+0x1da/0x204
[87078.464494]  [<ffffffff8106f21c>] wake_up_process+0x15/0x17
[87078.464495]  [<ffffffff8106022e>] wake_up_worker+0x28/0x2a
[87078.464496]  [<ffffffff81060835>] insert_work+0x65/0x6e
[87078.464496]  [<ffffffff81060d29>] __queue_work+0x2c8/0x302
[87078.464497]  [<ffffffff81074589>] ? update_cfs_rq_load_avg+0x310/0x349
[87078.464498]  [<ffffffff8106157b>] queue_work_on+0x38/0x47
[87078.464499]  [<ffffffff8147d077>] dbs_irq_work+0x23/0x25
[87078.464499]  [<ffffffff810e7234>] irq_work_run_list+0x43/0x61
[87078.464500]  [<ffffffff810f091a>] ? perf_event_sysfs_show+0x22/0x22
[87078.464501]  [<ffffffff810e726a>] irq_work_run+0x18/0x34
[87078.464502]  [<ffffffff810ac24c>] flush_smp_call_function_queue+0xd0/0x134
[87078.464502]  [<ffffffff810ac957>] generic_smp_call_function_single_interrupt+0x13/0x4c
[87078.464503]  [<ffffffff81032a09>] smp_call_function_single_interrupt+0x13/0x21
[87078.464504]  [<ffffffff8158f04f>] call_function_single_interrupt+0x7f/0x90
[87078.464505]  [<ffffffff81052951>] ? __do_softirq+0x7d/0x265
[87078.464506]  [<ffffffff810a7ab6>] ? tick_program_event+0x62/0x69
[87078.464506]  [<ffffffff81052cce>] irq_exit+0x52/0x93
[87078.464507]  [<ffffffff81034bd6>] smp_apic_timer_interrupt+0x2e/0x39
[87078.464508]  [<ffffffff8158e98f>] apic_timer_interrupt+0x7f/0x90
[87078.464508]  <EOI> 4---[ end trace 26fda82430e3fa2e ]---