Comment 13 for bug 1711358

Trace with 4.13
kernel BUG at /build/linux-jlxc7t/linux-4.13.0/drivers/gpu/drm/ttm/ttm_bo_util.c:589!
invalid opcode: 0000 [#1] SMP
Modules linked in: overlay nls_utf8 isofs dm_mirror dm_region_hash dm_log qxl ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm psmouse pata_acpi e1000 floppy
CPU: 0 PID: 210 Comm: plymouthd Not tainted 4.13.0-11-generic #12-UbuntuJ
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
task: ffff9b5639bb9600 task.stack: ffffbac6806ac000
RIP: 0010:ttm_bo_kmap+0x1b5/0x260 [ttm]
RSP: 0018:ffffbac6806afb80 EFLAGS: 00010202
RAX: ffff9b5639831f90 RBX: ffff9b5639b18000 RCX: ffff9b5639b18290
RDX: 0000000000000300 RSI: 0000000000000000 RDI: ffff9b5639b18058
RBP: ffffbac6806afbc0 R08: ffff9b5639b18128 R09: 0000000000000400
R10: 0000000000000008 R11: 0000000000001559 R12: ffff9b5639e206a8
R13: 0000000000000000 R14: ffff9b563ab52b40 R15: 0000000000000000
FS: 00007f203aef2b80(0000) GS:ffff9b563dc00000(0000) knlGS:0000000000000000^
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f245a8d3f20 CR3: 000000007a0a7000 CR4: 00000000000006f0
Call Trace:
 ? qxl_bo_kunmap_atomic_page+0x85/0x90 [qxl]-c
 qxl_bo_kmap+0x42/0x70 [qxl]ut
 qxl_draw_dirty_fb+0x1f5/0x420 [qxl]
 qxl_framebuffer_surface_dirty+0xa0/0xf0 [qxl]
 ? __kmalloc+0x1c5/0x200o
 drm_mode_dirtyfb_ioctl+0x17e/0x1c0 [drm]
 ? drm_mode_getfb+0x110/0x110 [drm]
 drm_ioctl_kernel+0x5d/0xb0 [drm]
 drm_ioctl+0x31b/0x3d0 [drm].
 ? drm_mode_getfb+0x110/0x110 [drm]
 ? ep_poll+0xa7/0x3b0
 do_vfs_ioctl+0xa5/0x610H
 ? wake_up_q+0x80/0x80
 SyS_ioctl+0x79/0x90
 entry_SYSCALL_64_fastpath+0x1e/0xa9.
RIP: 0033:0x7f203a5cedd7
RSP: 002b:00007ffdbe6da488 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000564f2479f3a0 RCX: 00007f203a5cedd7
RDX: 00007ffdbe6da4c0 RSI: 00000000c01864b1 RDI: 0000000000000009
RBP: 0000000000000002 R08: ffffffffffffff80 R09: 00007ffdbe6da460
R10: 000000000000000a R11: 0000000000000246 R12: 00007ffdbe6da760
R13: 00000000ffffffff R14: 0000000000000000 R15: 00007f203acd32d0
Code: d0 49 8b be 80 00 00 00 48 c1 e6 0c 41 f6 46 62 04 74 4a 49 03 7e 70 4c 01 e7 e8 97 33 b3 ca 48 89 03 44 8b 45 d0 e9 18 ff ff ff <0f> 0b 4b 8d 7c 2c 58 44 89 45 c4 e8 0b b0 3c cb 44 8b 45 c4 e9
&RIP: ttm_bo_kmap+0x1b5/0x260 [ttm] RSP: ffffbac6806afb80