Running glxgears with Indirect GLX crashes Xorg

[Lucy Llewellyn]

Replication Steps
-----------------

sudo mv /usr/bin/Xorg /usr/bin/Xorg.real
echo <<EOF | sudo tee /usr/bin/Xorg
#!/bin/sh
exec /usr/bin/Xorg.real "$@" +iglx
EOF
sudo chmod +x /usr/bin/Xorg

--- restart your session to get the +iglx flag applied ---

env LIBGL_ALWAYS_INDIRECT=1 glxgears

--- X11 crashes here ---

This requires an AMD graphics card and the open source drivers. Attempting to replicate in a VMware session (vmsvga drivers) does not reproduce the issue. I need to check nVidia (I do have an nVidia card I can put into this machine to test).

ProblemType: Bug
DistroRelease: Ubuntu 18.10
Package: libglx-mesa0 18.2.2-0ubuntu1
ProcVersionSignature: Ubuntu 4.18.0-16.17-generic 4.18.20
Uname: Linux 4.18.0-16-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.10-0ubuntu13.2
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
Date: Thu Mar 14 14:41:06 2019
DistUpgraded: Fresh install
DistroCodename: cosmic
DistroVariant: ubuntu
DkmsStatus:
 virtualbox, 5.2.18, 4.18.0-15-generic, x86_64: installed
 virtualbox, 5.2.18, 4.18.0-16-generic, x86_64: installed
ExtraDebuggingInterest: Yes, if not too technical
GraphicsCard:
 Subsystem: Gigabyte Technology Co., Ltd HD Graphics 530 [1458:d000]
 Advanced Micro Devices, Inc. [AMD/ATI] Baffin [Radeon RX 550 640SP / RX 560/560X] [1002:67ff] (rev cf) (prog-if 00 [VGA controller])
   Subsystem: ASUSTeK Computer Inc. Baffin [Radeon RX 550 640SP / RX 560/560X] [1043:04be]
InstallationDate: Installed on 2018-12-13 (90 days ago)
InstallationMedia: Ubuntu 18.10 "Cosmic Cuttlefish" - Release amd64 (20181017.3)
MachineType: Gigabyte Technology Co., Ltd. Z170X-UD5 TH
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.18.0-16-generic root=UUID=15d5f2c3-35e8-4aa4-a3b0-74b8c9b40dc4 ro quiet splash vt.handoff=1
SourcePackage: mesa
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 03/09/2018
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: F22g
dmi.board.asset.tag: Default string
dmi.board.name: Z170X-UD5 TH-CF
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: Default string
dmi.chassis.asset.tag: Default string
dmi.chassis.type: 3
dmi.chassis.vendor: Default string
dmi.chassis.version: Default string
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrF22g:bd03/09/2018:svnGigabyteTechnologyCo.,Ltd.:pnZ170X-UD5TH:pvrDefaultstring:rvnGigabyteTechnologyCo.,Ltd.:rnZ170X-UD5TH-CF:rvrDefaultstring:cvnDefaultstring:ct3:cvrDefaultstring:
dmi.product.family: Default string
dmi.product.name: Z170X-UD5 TH
dmi.product.sku: Default string
dmi.product.version: Default string
dmi.sys.vendor: Gigabyte Technology Co., Ltd.
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.95-1
version.libgl1-mesa-dri: libgl1-mesa-dri 18.2.2-0ubuntu1
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.20.1-3ubuntu2.1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:18.1.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20171229-1ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.15-3

[Lucy Llewellyn (lucyllewy)]

The crash is in XorgLogOld.txt, and the backtrace reproduced here:

[ 9027.274] (EE) Backtrace:
[ 9027.274] (EE) 0: /usr/lib/xorg/Xorg (OsLookupColor+0x139) [0x55b9210ba229]
[ 9027.275] (EE) 1: /lib/x86_64-linux-gnu/libpthread.so.0 (funlockfile+0x50) [0x7fdf6dcc4e1f]
[ 9027.275] (EE) 2: /usr/lib/xorg/Xorg (ResetCurrentRequest+0xb) [0x55b9210b92ab]
[ 9027.275] (EE) 3: /usr/lib/xorg/Xorg (DRI2WaitSwap+0x56) [0x55b921086716]
[ 9027.275] (EE) unw_get_proc_name failed: no unwind info found [-10]
[ 9027.275] (EE) 4: /usr/lib/xorg/modules/extensions/libglx.so (?+0x0) [0x7fdf6c7faa20]
[ 9027.276] (EE) unw_get_proc_name failed: no unwind info found [-10]
[ 9027.276] (EE) 5: /usr/lib/xorg/modules/extensions/libglx.so (?+0x0) [0x7fdf6c7f3010]
[ 9027.276] (EE) unw_get_proc_name failed: no unwind info found [-10]
[ 9027.276] (EE) 6: /usr/lib/xorg/modules/extensions/libglx.so (?+0x0) [0x7fdf6c7eefd0]
[ 9027.276] (EE) 7: /usr/lib/xorg/Xorg (dri3_send_open_reply+0xe2a) [0x55b92108b12a]
[ 9027.277] (EE) 8: /usr/lib/xorg/Xorg (_CallCallbacks+0x34) [0x55b920f60be4]
[ 9027.277] (EE) 9: /usr/lib/xorg/Xorg (CloseDownClient+0x5f) [0x55b920f5acbf]
[ 9027.277] (EE) 10: /usr/lib/xorg/Xorg (OsCleanup+0x591) [0x55b9210bb021]
[ 9027.277] (EE) 11: /usr/lib/xorg/Xorg (WaitForSomething+0x1c3) [0x55b9210b3b93]
[ 9027.277] (EE) 12: /usr/lib/xorg/Xorg (SendErrorToClient+0x10c) [0x55b920f5b72c]
[ 9027.277] (EE) 13: /usr/lib/xorg/Xorg (InitFonts+0x3b6) [0x55b920f5f906]
[ 9027.278] (EE) 14: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xeb) [0x7fdf6daea09b]
[ 9027.278] (EE) 15: /usr/lib/xorg/Xorg (_start+0x2a) [0x55b920f4967a]
[ 9027.278] (EE)
[ 9027.278] (EE) Segmentation fault at address 0x8
[ 9027.278] (EE)
Fatal server error:
[ 9027.278] (EE) Caught signal 11 (Segmentation fault). Server aborting

[Lucy Llewellyn (lucyllewy)]

Also crashes with nVidia using nouveau drivers (see attached log)

[Lucy Llewellyn (lucyllewy)]

Also affects Disco