[   37.981447] BUG: rwlock recursion on CPU#0, tracer_test/1075, c8add2b4
[   37.982015] CPU: 0 PID: 1075 Comm: tracer_test Tainted: G           O 3.13.0 #20
[   37.982225] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   37.982225]  00000000 00000000 c780bee8 c175dacc c19671c5 c780bf10 c175af0c c195ee68
[   37.982225]  c19671c5 00000000 c7a4d4fc 00000433 c8add2b4 c8add2b4 00000000 c780bf1c
[   37.982225]  c107ce05 c8add2b4 c780bf38 c1766c2f 00000000 00000001 00000000 c8adc1e6
[   37.982225] Call Trace:
[   37.982225]  [] dump_stack+0x41/0x52
[   37.982225]  [] rwlock_bug+0x57/0x5e
[   37.982225]  [] do_raw_write_lock+0x75/0x80
[   37.982225]  [] _raw_write_lock+0x3f/0x50
[   37.982225]  [] ? __tracer_kfree_handler+0x16/0xa0 [tracer]
[   37.982225]  [] __tracer_kfree_handler+0x16/0xa0 [tracer]
[   37.982225]  [] ftrace_graph_exit_task+0x1a/0x20
[   37.982225]  [] free_task+0x34/0x60
[   37.982225]  [] __put_task_struct+0x78/0x110
[   37.982225]  [] delayed_put_task_struct+0x3f/0x70
[   37.982225]  [] rcu_process_callbacks+0x16d/0x460
[   37.982225]  [] __do_softirq+0xbc/0x210
[   37.982225]  [] ? perf_trace_irq_handler_entry+0x120/0x120
[   37.982225]    [] ? irq_exit+0x85/0x90
[   37.982225]  [] ? smp_apic_timer_interrupt+0x38/0x50
[   37.982225]  [] ? apic_timer_interrupt+0x2d/0x34
[   37.982225]  [] ? tracer_ioctl+0xd8/0x150 [tracer]
[   37.982225]  [] ? tracer_proc_show+0xc0/0xc0 [tracer]
[   37.982225]  [] ? do_vfs_ioctl+0x6f/0x5b0
[   37.982225]  [] ? inode_has_perm.isra.27+0x32/0x40
[   37.982225]  [] ? file_has_perm+0x98/0xb0
[   37.982225]  [] ? putname+0x24/0x40
[   37.982225]  [] ? selinux_file_ioctl+0x48/0xe0
[   37.982225]  [] ? SyS_ioctl+0x78/0x90
[   37.982225]  [] ? sysenter_do_call+0x12/0x2d