Nightingale shell
$ crash
usage: crash [option]
  -s: null deref (userland)
  -S: null deref (syscall)
$ crash -s
** Segmentation fault **
Thread: [3:2] ("crash") performed an access violation
Attempted to access: data:0x0, Got: page not present
Fault occured at 0x40011f
    rax:                0    r8 : ffffffffffffffff
    rbx:     7fffff001000    r9 :                0
    rcx:                0    r10: ffffffffffffffff
    rdx:                0    r11:                0
    rsp:     7ffffeffffb8    r12:     7fffff001000
    rbp:     7ffffeffffc8    r13:                0
    rsi:           400e10    r14:                0
    rdi:     7fffff011006    r15:                0
    rip:           40011f    rfl: [ P Z  I       ] (246)
    cr3:           5cf000    pid:                3
backtrace
    bp:     7ffffeffffc8    ip:           40011f
    bp:     7ffffeffffc8    ip:           400d21
    bp:     7ffffeffffe8    ip:                0
-> 1
$ crash -S
Fault reading data:0x0 because page not present from kernel mode.
NULL pointer access?
Fault occured at 0xffffffff80108cb7
    rax:                0    r8 : ffffffffffffffff
    rbx:               31    r9 :                0
    rcx:                0    r10: ffffffff80108cb3
    rdx:                0    r11:                0
    rsp: fffffff00084ce70    r12:                0
    rbp: fffffff00084ceb8    r13:                0
    rsi:                0    r14:                0
    rdi:                0    r15:                0
    rip: ffffffff80108cb7    rfl: [ P Z  I       ] (246)
    cr3:           5f3000    pid:                3
backtrace from: 0xfffffff00084ceb8
(0xffffffff80108cb7) <sys_fault+0x4>
(0xffffffff8010fc87) <syscall_handler+0x9c>
(0xffffffff801101f7) <c_interrupt_shim+0x7e>
(0xffffffff80107030) <interrupt_shim+0x30>
end of memory
$