[   11.391446][  T110] su (110) used greatest stack depth: 24104 bytes left
[   11.391463][  T110] BUG: sleeping function called from invalid context at ./include/linux/sched/mm.h:322
[   11.391465][  T110] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 110, name: su
[   11.391466][  T110] preempt_count: 2, expected: 0
[   11.391467][  T110] RCU nest depth: 0, expected: 0
[   11.391468][  T110] locks held by su/110: 5, last CPU#1:
[   11.391470][  T110]  #0: ffffffffb2e027b8 (low_water_lock){+.+.}-{3:3}, at: do_exit+0x887/0xdc0
[   11.391481][  T110]  #1: ffffffffb2f69cc0 (console_lock){+.+.}-{0:0}, at: vprintk_emit+0x320/0x3e0
[   11.391486][  T110]  #2: ffffffffb2f69d38 (console_srcu){....}-{0:0}, at: console_flush_one_record+0x106/0x710
[   11.391489][  T110]  #3: ffffffffb2e89660 (console_owner){....}-{0:0}, at: console_lock_spinning_enable+0x40/0x60
[   11.391492][  T110]  #4: ffffffffb2e89560 (printk_legacy_map-wait-type-override){....}-{3:3}, at: console_emit_next_record+0x1df/0x4c0
[   11.391496][  T110] irq event stamp: 155470
[   11.391497][  T110] hardirqs last  enabled at (155469): [<ffffffffafd6d546>] __down_trylock_console_sem+0x86/0xa0
[   11.391500][  T110] hardirqs last disabled at (155470): [<ffffffffafd735f4>] console_emit_next_record+0x3d4/0x4c0
[   11.391501][  T110] softirqs last  enabled at (155018): [<ffffffffafbcaa2c>] handle_softirqs+0x67c/0x900
[   11.391503][  T110] softirqs last disabled at (155007): [<ffffffffafbcae65>] __irq_exit_rcu+0x145/0x1c0
[   11.391506][  T110] Preemption disabled at:
[   11.391506][  T110] [<0000000000000000>] 0x0
[   11.391513][  T110] CPU: 1 UID: 0 PID: 110 Comm: su Tainted: G        W           7.2.0-virtme #1 PREEMPT(full) 
[   11.391516][  T110] Tainted: [W]=WARN
[   11.391517][  T110] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   11.391518][  T110] Call Trace:
[   11.391520][  T110]  <TASK>
[   11.391521][  T110]  dump_stack_lvl+0x6f/0xa0
[   11.391527][  T110]  __might_resched.cold+0x1fe/0x2c1
[   11.391531][  T110]  ? perf_trace_sched_switch+0x7c0/0x7c0
[   11.391534][  T110]  ? __kmalloc_noprof+0xdb/0x760
[   11.391539][  T110]  __kmalloc_noprof+0x443/0x760
[   11.391542][  T110]  ? alloc_buf.isra.0+0x4b/0x260
[   11.391548][  T110]  ? do_raw_spin_unlock+0x59/0x250
[   11.391550][  T110]  alloc_buf.isra.0+0x4b/0x260
[   11.391554][  T110]  put_chars+0x1e1/0x2f0
[   11.391557][  T110]  ? __send_to_port+0x420/0x420
[   11.391558][  T110]  ? rcu_lockdep_current_cpu_online+0x3f/0x1b0