======================================
| [  515.123007] #PF: supervisor read access in kernel mode
| [  515.123042] #PF: error_code(0x0000) - not-present page
| [  515.123077] PGD 0 P4D 0
| [  515.123102] Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
[  515.123196] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  515.123240] RIP: 0010:full_proxy_write (fs/debugfs/file.c:394 (discriminator 5)) 
[ 515.123284] Code: 02 74 64 48 89 fd 49 89 f5 4c 89 ff 31 f6 49 89 ce e8 b4 fd ff ff 4c 63 e0 4d 85 e4 75 29 48 8b 03 48 8b 14 24 48 85 c0 74 33 <48> 8b 40 20 48 89 ef 4c 89 f1 4c 89 ee ff d0 0f 1f 00 4c 89 ff 49
All code
========
   0:	02 74 64 48          	add    0x48(%rsp,%riz,2),%dh
   4:	89 fd                	mov    %edi,%ebp
   6:	49 89 f5             	mov    %rsi,%r13
   9:	4c 89 ff             	mov    %r15,%rdi
   c:	31 f6                	xor    %esi,%esi
   e:	49 89 ce             	mov    %rcx,%r14
  11:	e8 b4 fd ff ff       	call   0xfffffffffffffdca
  16:	4c 63 e0             	movslq %eax,%r12
  19:	4d 85 e4             	test   %r12,%r12
  1c:	75 29                	jne    0x47
  1e:	48 8b 03             	mov    (%rbx),%rax
  21:	48 8b 14 24          	mov    (%rsp),%rdx
  25:	48 85 c0             	test   %rax,%rax
  28:	74 33                	je     0x5d
  2a:*	48 8b 40 20          	mov    0x20(%rax),%rax		<-- trapping instruction
  2e:	48 89 ef             	mov    %rbp,%rdi
  31:	4c 89 f1             	mov    %r14,%rcx
  34:	4c 89 ee             	mov    %r13,%rsi
  37:	ff d0                	call   *%rax
  39:	0f 1f 00             	nopl   (%rax)
  3c:	4c 89 ff             	mov    %r15,%rdi
  3f:	49                   	rex.WB

Code starting with the faulting instruction
===========================================
   0:	48 8b 40 20          	mov    0x20(%rax),%rax
   4:	48 89 ef             	mov    %rbp,%rdi
   7:	4c 89 f1             	mov    %r14,%rcx
   a:	4c 89 ee             	mov    %r13,%rsi
   d:	ff d0                	call   *%rax
   f:	0f 1f 00             	nopl   (%rax)
  12:	4c 89 ff             	mov    %r15,%rdi
  15:	49                   	rex.WB
[  515.123405] RSP: 0018:ffffbfff4068fe38 EFLAGS: 00010202
[  515.123443] RAX: 0000000002e6a358 RBX: ffff9cb1090f1080 RCX: 0000000000000002
[  515.123493] RDX: 0000000000000002 RSI: 0000000000000000 RDI: ffff9cb1090f1090
[  515.123544] RBP: ffff9cb106f733c0 R08: 0000000000000000 R09: 0000000000000000
[  515.123594] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[  515.123645] R13: 000055883993ad30 R14: ffffbfff4068ff08 R15: ffff9cb10a1bb600
[  515.123697] FS:  00007f563b4b4740(0000) GS:ffff9cb13ed00000(0000) knlGS:0000000000000000
[  515.123751] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  515.123796] CR2: 0000000002e6a378 CR3: 0000000009bd4003 CR4: 0000000000772ef0
[  515.123848] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  515.123897] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  515.123947] PKRU: 55555554
[  515.123967] Call Trace:
[  515.123995]  <TASK>
[  515.124018] ? __die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434) 
[  515.124107] ? page_fault_oops (arch/x86/mm/fault.c:715) 
[  515.124144] ? filemap_map_pages (mm/filemap.c:3828) 
[  515.124190] ? exc_page_fault (./arch/x86/include/asm/irqflags.h:37 ./arch/x86/include/asm/irqflags.h:92 arch/x86/mm/fault.c:1489 arch/x86/mm/fault.c:1539) 
[  515.124224] ? asm_exc_page_fault (./arch/x86/include/asm/idtentry.h:623) 
[  515.124256] ? full_proxy_write (fs/debugfs/file.c:394 (discriminator 5)) 
[  515.124286] ? full_proxy_write (fs/debugfs/file.c:394) 
[  515.124315] vfs_write (fs/read_write.c:677) 
[  515.124349] ? handle_mm_fault (mm/memory.c:6213) 
[  515.124381] ksys_write (fs/read_write.c:731) 
[  515.124409] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[  515.124441] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[  515.124479] RIP: 0033:0x7f563b5f5b77
[ 515.124514] Code: 0b 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
All code
========
   0:	0b 00                	or     (%rax),%eax
   2:	f7 d8                	neg    %eax
   4:	64 89 02             	mov    %eax,%fs:(%rdx)
   7:	48 c7 c0 ff ff ff ff 	mov    $0xffffffffffffffff,%rax
   e:	eb b7                	jmp    0xffffffffffffffc7
  10:	0f 1f 00             	nopl   (%rax)
  13:	f3 0f 1e fa          	endbr64
  17:	64 8b 04 25 18 00 00 	mov    %fs:0x18,%eax
  1e:	00 
  1f:	85 c0                	test   %eax,%eax
  21:	75 10                	jne    0x33
  23:	b8 01 00 00 00       	mov    $0x1,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 51                	ja     0x83
  32:	c3                   	ret
  33:	48 83 ec 28          	sub    $0x28,%rsp
  37:	48 89 54 24 18       	mov    %rdx,0x18(%rsp)
  3c:	48                   	rex.W
  3d:	89                   	.byte 0x89
  3e:	74 24                	je     0x64

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 51                	ja     0x59
   8:	c3                   	ret
   9:	48 83 ec 28          	sub    $0x28,%rsp
   d:	48 89 54 24 18       	mov    %rdx,0x18(%rsp)
  12:	48                   	rex.W
  13:	89                   	.byte 0x89
  14:	74 24                	je     0x3a
[  515.124624] RSP: 002b:00007ffc2b5d7b08 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[  515.124677] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f563b5f5b77
[  515.124728] RDX: 0000000000000002 RSI: 000055883993ad30 RDI: 0000000000000001
[  515.124778] RBP: 000055883993ad30 R08: 0000000000000000 R09: 00007f563b6684e0
[  515.124829] R10: 00007f563b6683e0 R11: 0000000000000246 R12: 0000000000000002


Finger prints:
full_proxy_write:vfs_write:ksys_write:do_syscall_64