kernel panic at kern/arch/x86/trap.c:540, from core 3: Double fault!  Check the kernel stack pointer; you likely ran off the end of the stack.
HW TRAP frame at 0xfffffff000020f40 on core 3
  rax  0x0000000080000001
  rbx  0xfffffff0000b2990
  rcx  0x00000000000003d4
  rdx  0x0000000000001280
  rbp  0xfffffff0000b2928
  rsi  0x0000000000000780
  rdi  0xffffffffc210eb30
  r8   0xffff8000000b8fa0
  r9   0x0000000000000f00
  r10  0xffff8000000b8f00
  r11  0xffff8000000b8ec0
  r12  0xffffffffc20c6e50
  r13  0xffff8000141e7d28
  r14  0x0000000000000001
  r15  0xffff800005aa5220
  trap 0x00000008 Double Fault
  gsbs 0xffffffffc8668140
  fsbs 0x0000000000000000
  err  0x--------00000000
  rip  0xffffffffc2048014
  cs   0x------------0008
  flag 0x0000000000010202
  rsp  0xfffffff0000b2928
  ss   0x------------0010
Backtrace of kernel context on Core 3:
#01 [<     [inline]     >] in spin_unlock_irqsave.part.2 at include/atomic.h:302
#01 [<0xffffffffc2048014>] in print_unlock.part.2 at src/printf.c:37
#02 [<     [inline]     >] in print_unlock at src/printf.c:34
#02 [<0xffffffffc2048288>] in vcprintf at src/printf.c:98
#03 [<0xffffffffc20482e3>] in cprintf at src/printf.c:112
#04 [<0xffffffffc207e72f>] in mountrpc at drivers/dev/mnt.c:801
#05 [<0xffffffffc207f21b>] in mntwalk at drivers/dev/mnt.c:462
#06 [<0xffffffffc2032d1d>] in walk at src/ns/chan.c:816
#07 [<0xffffffffc2033429>] in __namec_from at src/ns/chan.c:1138
#08 [<0xffffffffc203400f>] in namec at src/ns/chan.c:1516
#09 [<0xffffffffc20414d6>] in sysopenat at src/ns/sysfile.c:590
#10 [<0xffffffffc205888f>] in sys_openat at src/syscall.c:1805
#11 [<0xffffffffc2059439>] in syscall at src/syscall.c:2528
#12 [<0xffffffffc2059604>] in run_local_syscall at src/syscall.c:2563
#13 [<0xffffffffc2059b39>] in prep_syscalls at src/syscall.c:2583
#14 [<0xffffffffc20ab38a>] in sysenter_callwrapper at arch/x86/trap.c:854