On 12/20/18 5:30 AM, Tetsuo Handa wrote: >> | Stack Trace: >> | arc_unwind_core+0xcc/0x100 >> | ___might_sleep+0x17a/0x190 >> | mmput+0x16/0xb8 > Then, does mmput_async() help? > It helps, but then we get the next one (w/o my patch 2/2) BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:23 in_atomic(): 1, irqs_disabled(): 0, pid: 69, name: segv-null-ptr no locks held by segv-null-ptr/69. CPU: 0 PID: 69 Comm: segv-null-ptr Not tainted 4.18.0+ #72 Stack Trace: arc_unwind_core+0xcc/0x100 ___might_sleep+0x17a/0x190 down_read+0x18/0x38 show_regs+0x102/0x310 get_signal+0x5ee/0x610 do_signal+0x2c/0x218 resume_user_mode_begin+0x90/0xd8 @off 0x103d4 in [/segv-null-pt