Hi,
I have spurious crashes of my X window system. Difficult to say,
but they seem to happen when I'm with two monitors and only with
certain applications. Spotify seems to be very good at triggering it
(when I double-click a playlist) and also GDM when GNOME session is starting
(X server crashes and restarts GDM login screen).

Here is what I found in logs:


[  2781.339] (II) intel(0): switch to mode 1920x1080@60.0 on HDMI3 using pipe
0, position (0, 0), rotation normal, reflection none
[  2781.687] (II) intel(0): switch to mode 1366x768@60.0 on LVDS1 using pipe 1,
position (1920, 0), rotation normal, reflection none
[  2792.475] (EE)
[  2792.475] (EE) Backtrace:
[  2792.476] (EE) 0: /usr/bin/Xorg (xorg_backtrace+0x56) [0x555555706df6]
[  2792.476] (EE) 1: /usr/bin/Xorg (0x555555554000+0x1b7009) [0x55555570b009]
[  2792.476] (EE) 2: /lib/x86_64-linux-gnu/libc.so.6 (0x7ffff5efe000+0x35180)
[0x7ffff5f33180]
[  2792.476] (EE) 3: /usr/lib/xorg/modules/drivers/intel_drv.so
(0x7ffff1c9f000+0xf9a46) [0x7ffff1d98a46]
[  2792.476] (EE) 4: /usr/lib/xorg/modules/drivers/intel_drv.so
(0x7ffff1c9f000+0x10c280) [0x7ffff1dab280]
[  2792.476] (EE) 5: /usr/lib/xorg/modules/drivers/intel_drv.so
(0x7ffff1c9f000+0x10d6cc) [0x7ffff1dac6cc]
[  2792.476] (EE) 6: /usr/lib/xorg/modules/drivers/intel_drv.so
(0x7ffff1c9f000+0x10e663) [0x7ffff1dad663]
[  2792.476] (EE) 7: /usr/bin/Xorg (DRI2SwapBuffers+0x1d0) [0x5555556d97a0]
[  2792.476] (EE) 8: /usr/bin/Xorg (0x555555554000+0x18711c) [0x5555556db11c]
[  2792.476] (EE) 9: /usr/bin/Xorg (0x555555554000+0x58117) [0x5555555ac117]
[  2792.476] (EE) 10: /usr/bin/Xorg (0x555555554000+0x5c29b) [0x5555555b029b]
[  2792.476] (EE) 11: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xf5)
[0x7ffff5f1fb45]
[  2792.476] (EE) 12: /usr/bin/Xorg (0x555555554000+0x4668e) [0x55555559a68e]
[  2792.476] (EE)
[  2792.476] (EE) Segmentation fault at address 0x7fffeeb60000
[  2792.476] (EE)
Fatal server error:
[  2792.476] (EE) Caught signal 11 (Segmentation fault). Server aborting


Note that this is with ASLR turned off, so addresses should be reproducible.

The same thing was reported by a user in https://bugs.debian.org/783507, and
he was asked to create another bug, and I'm doing this for him and me. Feel
free to merge if necessary.

I made it "important", because it may lead to data loss. And also is infinitely
frustrating to be able to crash X server with a single application.

Cheers,
Tomasz

I am seeing the same crash with the same backtrace:

[512937.361] (II) intel(0): resizing framebuffer to 1600x900
[512937.365] (II) intel(0): switch to mode 1600x900@60.0 on LVDS1 using pipe 0, position (0, 0), rotation normal, reflection none
[642161.462] (EE)
[642161.465] (EE) Backtrace:
[642161.475] (EE) 0: /usr/bin/X (xorg_backtrace+0x56) [0x7f2332fa6df6]
[642161.476] (EE) 1: /usr/bin/X (0x7f2332df4000+0x1b7009) [0x7f2332fab009]
[642161.476] (EE) 2: /lib/x86_64-linux-gnu/libc.so.6 (0x7f2330cf3000+0x35180) [0x7f2330d28180]
[642161.476] (EE) 3: /usr/lib/xorg/modules/drivers/intel_drv.so (0x7f232ca95000+0x5e2aa) [0x7f232caf32aa]
[642161.476] (EE) 4: /usr/lib/xorg/modules/drivers/intel_drv.so (0x7f232ca95000+0xf6cd2) [0x7f232cb8bcd2]
[642161.476] (EE) 5: /usr/lib/xorg/modules/drivers/intel_drv.so (0x7f232ca95000+0x10ba30) [0x7f232cba0a30]
[642161.476] (EE) 6: /usr/lib/xorg/modules/drivers/intel_drv.so (0x7f232ca95000+0x10ce3c) [0x7f232cba1e3c]
[642161.476] (EE) 7: /usr/lib/xorg/modules/drivers/intel_drv.so (0x7f232ca95000+0x10d828) [0x7f232cba2828]
[642161.476] (EE) 8: /usr/bin/X (DRI2SwapBuffers+0x1d0) [0x7f2332f797a0]
[642161.476] (EE) 9: /usr/bin/X (0x7f2332df4000+0x18711c) [0x7f2332f7b11c]
[642161.476] (EE) 10: /usr/bin/X (0x7f2332df4000+0x58117) [0x7f2332e4c117]
[642161.476] (EE) 11: /usr/bin/X (0x7f2332df4000+0x5c29b) [0x7f2332e5029b]
[642161.476] (EE) 12: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xf5) [0x7f2330d14b45]
[642161.476] (EE) 13: /usr/bin/X (0x7f2332df4000+0x4668e) [0x7f2332e3a68e]
[642161.476] (EE)
[642161.476] (EE) Segmentation fault at address 0x7f233324b000
[642161.476] (EE)
Fatal server error:
[642161.476] (EE) Caught signal 11 (Segmentation fault). Server aborting
[642161.476] (EE)
[642161.476] (EE)

I sometimes use multiple monitors, like OP, but this crash seems to be
far removed from that. Both times I've seen this crash I've been using
Google Chrome.

MM

I guess I have the same problem.

I'm not able to login anymore in kde and trying to figuring out why, I
noticed glx doesn't work.

I tried to generate xorg.conf with Xorg -configure e this is the log:

[  1677.834]
X.Org X Server 1.17.2
Release Date: 2015-06-16
[  1677.834] X Protocol Version 11, Revision 0
[  1677.834] Build Operating System: Linux 4.1.0 x86_64 Debian
[  1677.834] Current Operating System: Linux adam 4.1.0-2-amd64 #1 SMP
Debian 4.1.6-1 (2015-08-23) x86_64
[  1677.834] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-4.1.0-2-amd64
root=UUID=5b0c290e-ac1a-425f-806c-560cfc38973f ro quiet
[  1677.834] Build Date: 11 August 2015  10:51:15AM
[  1677.834] xorg-server 2:1.17.2-1.1 (http://www.debian.org/support)
[  1677.835] Current version of pixman: 0.32.6
[  1677.835]     Before reporting problems, check http://wiki.x.org
     to make sure that you have the latest version.
[  1677.835] Markers: (--) probed, (**) from config file, (==) default
setting,
     (++) from command line, (!!) notice, (II) informational,
     (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
[  1677.835] (==) Log file: "/var/log/Xorg.0.log", Time: Sun Aug 30
15:36:39 2015
[  1677.835] (II) Loader magic: 0x561442cddd40
[  1677.835] (II) Module ABI versions:
[  1677.835]     X.Org ANSI C Emulation: 0.4
[  1677.835]     X.Org Video Driver: 19.0
[  1677.835]     X.Org XInput driver : 21.0
[  1677.835]     X.Org Server Extension : 9.0
[  1677.835] (II) xfree86: Adding drm device (/dev/dri/card0)
[  1677.837] (--) PCI:*(0:0:2:0) 8086:0166:17aa:3977 rev 9, Mem @
0xd0000000/4194304, 0xc0000000/268435456, I/O @ 0x00003000/64
[  1677.837] List of video drivers:
[  1677.837]     siliconmotion
[  1677.837]     openchrome
[  1677.837]     radeon
[  1677.837]     nouveau
[  1677.837]     intel
[  1677.837]     mach64
[  1677.838]     savage
[  1677.839]     trident
[  1677.839]     ati
[  1677.840]     tdfx
[  1677.841]     vmware
[  1677.842]     cirrus
[  1677.843]     r128
[  1677.843]     mga
[  1677.844]     sisusb
[  1677.845]     qxl
[  1677.845]     neomagic
[  1677.846]     vesa
[  1677.847]     fbdev
[  1677.847]     modesetting
[  1677.847] (II) LoadModule: "siliconmotion"
[  1677.848] (II) Loading /usr/lib/xorg/modules/drivers/siliconmotion_drv.so
[  1677.898] (II) Module siliconmotion: vendor="X.Org Foundation"
[  1677.898]     compiled for 1.17.1, module version = 1.7.8
[  1677.898]     Module class: X.Org Video Driver
[  1677.898]     ABI class: X.Org Video Driver, version 19.0
[  1677.905] (II) LoadModule: "openchrome"
[  1677.905] (II) Loading /usr/lib/xorg/modules/drivers/openchrome_drv.so
[  1678.023] (II) Module openchrome: vendor="http://openchrome.org/"
[  1678.023]     compiled for 1.17.1, module version = 0.3.3
[  1678.023]     Module class: X.Org Video Driver
[  1678.023]     ABI class: X.Org Video Driver, version 19.0
[  1678.023] (II) LoadModule: "radeon"
[  1678.023] (II) Loading /usr/lib/xorg/modules/drivers/radeon_drv.so
[  1678.170] (II) Module radeon: vendor="X.Org Foundation"
[  1678.170]     compiled for 1.17.1, module version = 7.5.0
[  1678.170]     Module class: X.Org Video Driver
[  1678.170]     ABI class: X.Org Video Driver, version 19.0
[  1678.170] (II) LoadModule: "nouveau"
[  1678.170] (II) Loading /usr/lib/xorg/modules/drivers/nouveau_drv.so
[  1678.237] (II) Module nouveau: vendor="X.Org Foundation"
[  1678.237]     compiled for 1.17.1, module version = 1.0.11
[  1678.237]     Module class: X.Org Video Driver
[  1678.237]     ABI class: X.Org Video Driver, version 19.0
[  1678.237] (II) LoadModule: "intel"
[  1678.238] (II) Loading /usr/lib/xorg/modules/drivers/intel_drv.so
[  1678.238] (II) Module intel: vendor="X.Org Foundation"
[  1678.238]     compiled for 1.17.2, module version = 2.99.917
[  1678.238]     Module class: X.Org Video Driver
[  1678.238]     ABI class: X.Org Video Driver, version 19.0
[  1678.238] (II) LoadModule: "mach64"
[  1678.238] (II) Loading /usr/lib/xorg/modules/drivers/mach64_drv.so
[  1678.338] (II) Module mach64: vendor="X.Org Foundation"
[  1678.338]     compiled for 1.17.1, module version = 6.9.5
[  1678.338]     Module class: X.Org Video Driver
[  1678.338]     ABI class: X.Org Video Driver, version 19.0
[  1678.338] (II) LoadModule: "savage"
[  1678.338] (II) Loading /usr/lib/xorg/modules/drivers/savage_drv.so
[  1678.383] (II) Module savage: vendor="X.Org Foundation"
[  1678.383]     compiled for 1.17.1, module version = 2.3.8
[  1678.383]     Module class: X.Org Video Driver
[  1678.383]     ABI class: X.Org Video Driver, version 19.0
[  1678.383] (II) LoadModule: "trident"
[  1678.383] (II) Loading /usr/lib/xorg/modules/drivers/trident_drv.so
[  1678.466] (II) Module trident: vendor="X.Org Foundation"
[  1678.466]     compiled for 1.17.1, module version = 1.3.7
[  1678.466]     Module class: X.Org Video Driver
[  1678.466]     ABI class: X.Org Video Driver, version 19.0
[  1678.484] (II) LoadModule: "ati"
[  1678.484] (II) Loading /usr/lib/xorg/modules/drivers/ati_drv.so
[  1678.495] (II) Module ati: vendor="X.Org Foundation"
[  1678.495]     compiled for 1.17.1, module version = 7.5.0
[  1678.495]     Module class: X.Org Video Driver
[  1678.495]     ABI class: X.Org Video Driver, version 19.0
[  1678.495] (II) LoadModule: "tdfx"
[  1678.495] (II) Loading /usr/lib/xorg/modules/drivers/tdfx_drv.so
[  1678.530] (II) Module tdfx: vendor="X.Org Foundation"
[  1678.531]     compiled for 1.17.1, module version = 1.4.6
[  1678.531]     Module class: X.Org Video Driver
[  1678.531]     ABI class: X.Org Video Driver, version 19.0
[  1678.531] (II) LoadModule: "vmware"
[  1678.531] (II) Loading /usr/lib/xorg/modules/drivers/vmware_drv.so
[  1680.447] (II) Module vmware: vendor="X.Org Foundation"
[  1680.447]     compiled for 1.17.1, module version = 13.1.0
[  1680.447]     Module class: X.Org Video Driver
[  1680.447]     ABI class: X.Org Video Driver, version 19.0
[  1680.447] (II) LoadModule: "cirrus"
[  1680.448] (II) Loading /usr/lib/xorg/modules/drivers/cirrus_drv.so
[  1680.601] (II) Module cirrus: vendor="X.Org Foundation"
[  1680.601]     compiled for 1.17.1, module version = 1.5.3
[  1680.601]     Module class: X.Org Video Driver
[  1680.602]     ABI class: X.Org Video Driver, version 19.0
[  1680.602] (II) LoadModule: "r128"
[  1680.602] (II) Loading /usr/lib/xorg/modules/drivers/r128_drv.so
[  1680.660] (II) Module r128: vendor="X.Org Foundation"
[  1680.660]     compiled for 1.17.1, module version = 6.10.0
[  1680.660]     Module class: X.Org Video Driver
[  1680.660]     ABI class: X.Org Video Driver, version 19.0
[  1680.660] (II) LoadModule: "mga"
[  1680.660] (II) Loading /usr/lib/xorg/modules/drivers/mga_drv.so
[  1680.723] (II) Module mga: vendor="X.Org Foundation"
[  1680.723]     compiled for 1.17.1, module version = 1.6.4
[  1680.723]     Module class: X.Org Video Driver
[  1680.723]     ABI class: X.Org Video Driver, version 19.0
[  1680.723] (II) LoadModule: "sisusb"
[  1680.723] (II) Loading /usr/lib/xorg/modules/drivers/sisusb_drv.so
[  1680.755] (II) Module sisusb: vendor="X.Org Foundation"
[  1680.755]     compiled for 1.17.1, module version = 0.9.6
[  1680.755]     Module class: X.Org Video Driver
[  1680.755]     ABI class: X.Org Video Driver, version 19.0
[  1680.755] (II) LoadModule: "qxl"
[  1680.755] (II) Loading /usr/lib/xorg/modules/drivers/qxl_drv.so
[  1680.833] (II) Module qxl: vendor="X.Org Foundation"
[  1680.833]     compiled for 1.17.1, module version = 0.1.4
[  1680.833]     Module class: X.Org Video Driver
[  1680.833]     ABI class: X.Org Video Driver, version 19.0
[  1680.833] (II) LoadModule: "neomagic"
[  1680.833] (II) Loading /usr/lib/xorg/modules/drivers/neomagic_drv.so
[  1680.880] (II) Module neomagic: vendor="X.Org Foundation"
[  1680.880]     compiled for 1.17.1, module version = 1.2.9
[  1680.880]     Module class: X.Org Video Driver
[  1680.880]     ABI class: X.Org Video Driver, version 19.0
[  1680.880] (II) LoadModule: "vesa"
[  1680.880] (II) Loading /usr/lib/xorg/modules/drivers/vesa_drv.so
[  1680.880] (II) Module vesa: vendor="X.Org Foundation"
[  1680.880]     compiled for 1.17.1, module version = 2.3.3
[  1680.880]     Module class: X.Org Video Driver
[  1680.880]     ABI class: X.Org Video Driver, version 19.0
[  1680.880] (II) LoadModule: "fbdev"
[  1680.880] (II) Loading /usr/lib/xorg/modules/drivers/fbdev_drv.so
[  1680.880] (II) Module fbdev: vendor="X.Org Foundation"
[  1680.880]     compiled for 1.17.1, module version = 0.4.4
[  1680.880]     Module class: X.Org Video Driver
[  1680.880]     ABI class: X.Org Video Driver, version 19.0
[  1680.880] (II) LoadModule: "modesetting"
[  1680.880] (II) Loading /usr/lib/xorg/modules/drivers/modesetting_drv.so
[  1680.881] (II) Module modesetting: vendor="X.Org Foundation"
[  1680.881]     compiled for 1.17.2, module version = 1.17.2
[  1680.881]     Module class: X.Org Video Driver
[  1680.881]     ABI class: X.Org Video Driver, version 19.0
[  1680.881] (WW) Falling back to old probe method for siliconmotion
[  1680.881] (EE)
[  1680.881] (EE) Backtrace:
[  1680.882] (EE) 0: Xorg (xorg_backtrace+0x4e) [0x561442a5685e]
[  1680.883] (EE) 1: Xorg (0x5614428a3000+0x1b7aa9) [0x561442a5aaa9]
[  1680.884] (EE) 2: /lib/x86_64-linux-gnu/libc.so.6
(0x7fabfb0e4000+0x35180) [0x7fabfb119180]
[  1680.884] (EE) 3: /usr/lib/xorg/modules/drivers/intel_drv.so
(0x7fabf8446000+0x150ba) [0x7fabf845b0ba]
[  1680.885] (EE) 4: Xorg (0x5614428a3000+0xb906b) [0x56144295c06b]
[  1680.886] (EE) 5: Xorg (0x5614428a3000+0xb91d0) [0x56144295c1d0]
[  1680.887] (EE) 6: Xorg (0x5614428a3000+0xb992a) [0x56144295c92a]
[  1680.887] (EE) 7: Xorg (xf86CallDriverProbe+0x17) [0x56144292f427]
[  1680.888] (EE) 8: Xorg (DoConfigure+0xd7) [0x56144292e317]
[  1680.889] (EE) 9: Xorg (InitOutput+0x126d) [0x56144293e89d]
[  1680.889] (EE) 10: Xorg (0x5614428a3000+0x5bfda) [0x5614428fefda]
[  1680.890] (EE) 11: /lib/x86_64-linux-gnu/libc.so.6
(__libc_start_main+0xf5) [0x7fabfb105b45]
[  1680.891] (EE) 12: Xorg (0x5614428a3000+0x465be) [0x5614428e95be]
[  1680.891] (EE)
[  1680.895] (EE) Segmentation fault at address 0x30
[  1680.896] (EE)
Fatal server error:
[  1680.897] (EE) Caught signal 11 (Segmentation fault). Server aborting
[  1680.898] (EE)
[  1680.899] (EE)
Please consult the The X.Org Foundation support
      at http://wiki.x.org
  for help.
[  1680.902] (EE) Please also check the log file at
"/var/log/Xorg.0.log" for additional information.
[  1680.903] (EE)

The problem I had was related to a conflict with nvidia driver.

I managed to solve it purging the following packages

Konsole output
nvidia-libopencl1:amd64 (340.76-5),
nvidia-alternative:amd64 (340.76-5),
nvidia-installer-cleanup:amd64 (20141201+1),
nvidia-opencl-common:amd64 (340.76-5),
libcuda1:amd64 (340.76-5),
glx-alternative-mesa:amd64 (0.5.1),
nvidia-modprobe:amd64 (349.16-1),
nvidia-opencl-icd:amd64 (340.76-5),
glx-diversions:amd64 (0.5.1),
libnvidia-compiler:amd64 (340.76-5),
glx-alternative-fglrx:amd64 (0.5.1),
libfglrx-amdxvba1:amd64 (15.7-1),
nvidia-kernel-3.16-3-amd64:amd64 (),
libnvidia-ml1:amd64 (340.76-5),
glx-alternative-nvidia:i386 (0.5.1),
nvidia-kernel-common:amd64 (),
libgl1-fglrx-glx:amd64 (15.7-1),
nvidia-smi:amd64 (340.76-5)

I still had spotify crashing my Intel driver.

On the issue of Matthew: the crash never happened to me in Google
Chrome, because I don't use it :). On the other hand, I sparingly use
Chromium, but I don't recall it triggerring this bug.

Cheers,
Tomasz