BUG: unable to handle kernel NULL pointer dereference at 00000000
*pde = 00000000
Oops: 0000 [#1] SMP
CPU: 0 PID: 0 Comm: swapper/0 Tainted: G           O      4.19.0+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014
EIP: htable+0xd0f/0xffffed00 [tracer]
Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 00 00 <00> 01 00 00 00 24 20 860
EAX: c6e40841 EBX: c6e40840 ECX: 00000000 EDX: c886331c
ESI: c886331c EDI: c16ee4a0 EBP: c781ffac ESP: c781ff38
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00000286
CR0: 80050033 CR2: 00000000 CR3: 06e54000 CR4: 00000690
Call Trace:
 <SOFTIRQ>
 ? rcu_process_callbacks+0x52f/0xe00
 ? rcu_process_callbacks+0x4c3/0xe00
 ? _raw_spin_unlock_irq+0x22/0x30
 ? run_timer_softirq+0x26e/0x290
 __do_softirq+0x17b/0x3c5
 ? __irqentry_text_end+0x1/0x1
 do_softirq_own_stack+0x57/0x70
 </SOFTIRQ>
 irq_exit+0x5b/0x90
 smp_apic_timer_interrupt+0x90/0x250
 ? trace_hardirqs_off_thunk+0xc/0x1a
 apic_timer_interrupt+0xda/0xe0
EIP: default_idle+0x26/0x180
Code: 90 90 90 90 55 89 e5 83 ec 10 89 5d f4 89 75 f8 89 7d fc 64 8b 3d 24 f1 7b c1 a1 b0 05 73 c1 85 c0 7f 31 e8 7c c1 bc ff fb f4 <64> 8b 3d 24 f1 7b c1 a1d
EAX: c152c1f4 EBX: 00000000 ECX: 00000001 EDX: 00000000
ESI: 00000000 EDI: 00000000 EBP: c16cdf1c ESP: c16cdf0c
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00000246
 ? default_idle+0x24/0x180
 arch_cpu_idle+0xd/0x10
 default_idle_call+0x19/0x30
 do_idle+0x17a/0x1b0
 cpu_startup_entry+0x65/0x70
 rest_init+0x1e0/0x1e5
 start_kernel+0x3a8/0x3be
 i386_start_kernel+0x93/0x97
 startup_32_smp+0x15f/0x164
Modules linked in: tracer_helper(O) tracer(O) [last unloaded: tracer]
CR2: 0000000000000000
---[ end trace bb8d4e57cdbdf2cc ]---
EIP: htable+0xd0f/0xffffed00 [tracer]
Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 00 00 <00> 01 00 00 00 24 20 860
EAX: c6e40841 EBX: c6e40840 ECX: 00000000 EDX: c886331c
ESI: c886331c EDI: c16ee4a0 EBP: c781ffac ESP: c17d847c
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00000286
CR0: 80050033 CR2: 00000000 CR3: 06e54000 CR4: 00000690
Kernel panic - not syncing: Fatal exception in interrupt
Kernel Offset: disabled
---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---