xwininfo crashed with SIGSEGV in Select_Window()

[Laurent Bonnaud]

I was trying a GNOME Wayland session and was using xwininfo to tell which windows where using XWayland and which windows where using Wayland.

At first it worked well but after a few uses it crashed and I could not use it any longer (it could not grab the input).

ProblemType: Crash
DistroRelease: Ubuntu 17.10
Package: x11-utils 7.7+3build1
ProcVersionSignature: Ubuntu 4.13.0-12.13-generic 4.13.3
Uname: Linux 4.13.0-12-generic x86_64
.tmp.unity_support_test.0:

ApportVersion: 2.20.7-0ubuntu1
Architecture: amd64
CompizPlugins: [core,composite,opengl,compiztoolbox,decor,vpswitch,snap,mousepoll,resize,place,move,wall,grid,regex,imgpng,session,gnomecompat,animation,fade,staticswitcher,workarounds,scale,expo,ezoom,dbus]
CompositorRunning: None
CurrentDesktop: GNOME
Date: Fri Sep 29 15:06:22 2017
DistUpgraded: 2017-09-29 12:50:04,977 DEBUG Running PostInstallScript: './xorg_fix_proprietary.py'
DistroCodename: artful
DistroVariant: ubuntu
EcryptfsInUse: Yes
ExecutablePath: /usr/bin/xwininfo
GconfCompiz:
 /apps/compiz-1/general:
   /apps/compiz-1/general/screen0:
    /apps/compiz-1/general/screen0/options:
     active_plugins = [core,composite,opengl,compiztoolbox,decor,vpswitch,snap,mousepoll,resize,place,move,wall,grid,regex,imgpng,session,gnomecompat,animation,fade,staticswitcher,workarounds,scale,expo,ezoom,dbus]
GraphicsCard:
 Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0126] (rev 09) (prog-if 00 [VGA controller])
   Subsystem: Dell 2nd Generation Core Processor Family Integrated Graphics Controller [1028:0494]
MachineType: Dell Inc. Latitude E6520
ProcCmdline: xwininfo
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.13.0-12-generic root=UUID=749a9901-bdd3-4b5f-b80e-69414667e058 ro enable_mtrr_cleanup mtrr_spare_reg_nr=1 mtrr_gran_size=32M mtrr_chunk_size=128M quiet splash vt.handoff=7
SegvAnalysis:
 Segfault happened at: 0x5620e67abc67: movzbl (%rax),%edx
 PC (0x5620e67abc67) ok
 source "(%rax)" (0x00000000) not located in a known VMA region (needed readable region)!
 destination "%edx" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: x11-utils
StacktraceTop:
 ?? ()
 ?? ()
 __libc_start_main (main=0x5620e67a9610, argc=1, argv=0x7fffb2ac4b58, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffb2ac4b48) at ../csu/libc-start.c:308
 ?? ()
Title: xwininfo crashed with SIGSEGV in __libc_start_main()
UpgradeStatus: Upgraded to artful on 2017-09-29 (0 days ago)
UserGroups: adm cdrom dip fuse libvirt libvirtd lpadmin plugdev sambashare staff sudo
dmi.bios.date: 11/14/2013
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A19
dmi.board.name: 0NVF5K
dmi.board.vendor: Dell Inc.
dmi.board.version: A01
dmi.chassis.type: 9
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA19:bd11/14/2013:svnDellInc.:pnLatitudeE6520:pvr01:rvnDellInc.:rn0NVF5K:rvrA01:cvnDellInc.:ct9:cvr:
dmi.product.name: Latitude E6520
dmi.product.version: 01
dmi.sys.vendor: Dell Inc.
version.compiz: compiz 1:0.9.13.1+17.10.20170901-0ubuntu1
version.libdrm2: libdrm2 2.4.82-1
version.libgl1-mesa-dri: libgl1-mesa-dri 17.2.1-0ubuntu1
version.libgl1-mesa-glx: libgl1-mesa-glx 17.2.1-0ubuntu1
version.xserver-xorg-core: xserver-xorg-core 2:1.19.3-1ubuntu6
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.5-1ubuntu1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.9.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20170309-0ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.15-2

[Apport retracing service (apport)]

StacktraceTop:
 Select_Window (dpy=0x5620e7a9c160, screen=<optimized out>, descend=1) at ../xwininfo/dsimple.c:208
 main (argc=1, argv=0x7fffb2ac4b58) at ../xwininfo/xwininfo.c:574

[Laurent Bonnaud (laurent-bonnaud)]

Closing this bug that I did not see again since my initial report.