kernel warning at kern/src/event.c:374, from core 0: [kernel] Null ev_q - kernel code should check before sending! Stack Backtrace on Core 0: #01 [<0xffffffffc200a33c>] in backtrace at src/kdebug.c:220 #02 [<0xffffffffc2009bd4>] in _warn at src/init.c:323 #03 [<0xffffffffc2007752>] in send_event at src/event.c:374 #04 [<0xffffffffc20560d5>] in sys_send_event at src/syscall.c:1439 #05 [<0xffffffffc2059569>] in syscall at src/syscall.c:2455 #06 [<0xffffffffc2059734>] in run_local_syscall at src/syscall.c:2490 #07 [<0xffffffffc2059c69>] in prep_syscalls at src/syscall.c:2510 #08 [<0xffffffffc20ab5fa>] in sysenter_callwrapper at arch/x86/trap.c:854