Created attachment 31981 [details]
Targz with a second gdb trace of xorg while starting compiz, dmesg, kern, debug includes, this time with drm.debug=0xf

2.6.32_rc8a_drm_readback_drmdebug0xf/
2.6.32_rc8a_drm_readback_drmdebug0xf/
2.6.32_rc8a_drm_readback_drmdebug0xf/dmesg.after3.txt
2.6.32_rc8a_drm_readback_drmdebug0xf/dmesg.before.txt
2.6.32_rc8a_drm_readback_drmdebug0xf/dmesg.after2.txt
2.6.32_rc8a_drm_readback_drmdebug0xf/messages.txt
2.6.32_rc8a_drm_readback_drmdebug0xf/dmesg.after.txt
2.6.32_rc8a_drm_readback_drmdebug0xf/compiz.gdb.log.txt
2.6.32_rc8a_drm_readback_drmdebug0xf/dmesg.after3a.txt
2.6.32_rc8a_drm_readback_drmdebug0xf/dmesg.boot.txt
2.6.32_rc8a_drm_readback_drmdebug0xf/debug.txt
2.6.32_rc8a_drm_readback_drmdebug0xf/xorg.gdb.log.txt
2.6.32_rc8a_drm_readback_drmdebug0xf/kern.log.txt

I have the same problem after software upgrade.

I use

ati-dri 7.9_rc2-1
libgl 7.9_rc2-1
mesa 7.9_rc2-1
xf86-video-ati 6.13.2-1
xorg-server 1.9.0-1
xorg-server-common 1.9.0-1

kernel26 2.6.35.5-1 and kernel26-custom 2.6.36_rc6-1

After some time Xorg randomly exits without messages in Xorg.0.log and I see subj error in dmesg.

I can not see correlation between this error and actions I do.

Moreover, it looks like degradation for me. I did not see this when I use packages listed in https://bugs.freedesktop.org/show_bug.cgi?id=29494

Issue was started when I switch to Xorg 1.9 and update drivers.

I also see an Xorg segfault and "[drm:drm_mode_getfb] *ERROR* invalid
framebuffer id" under x86_64 with radeon driver and Xinerama across
two FireMV cards running 3 LCD monitors.

The simplest case: From a console (no X running) start Xorg (as root, no
window manager).  Start xload.  Run "import" (from ImageMagick) and select
the xload window to import.  Boom.  I get a similar segfault running vtwm
and trying to move or resize a window.  Here's the segfault and Backtrace:

# Xorg

X.Org X Server 1.9.0
Release Date: 2010-08-20
X Protocol Version 11, Revision 0
Build Operating System: Linux 2.6.24-27-server x86_64 Ubuntu
Current Operating System: Linux ian 2.6.35-22-generic #35-Ubuntu SMP Sat Oct 16 20:45:36 UTC 2010 x86_64
Kernel command line: BOOT_IMAGE=/vmlinuz-2.6.35-22-generic root=UUID=e2fb2eaa-3c3b-47cf-8143-68a7b0b09b81 ro resume=/dev/sda2
Build Date: 16 September 2010  06:18:41PM
xorg-server 2:1.9.0-0ubuntu7 (For technical support please see http://www.ubuntu.com/support)
Current version of pixman: 0.18.4
        Before reporting problems, check http://wiki.x.org
        to make sure that you have the latest version.
Markers: (--) probed, (**) from config file, (==) default setting,
        (++) from command line, (!!) notice, (II) informational,
        (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/var/log/Xorg.0.log", Time: Thu Oct 28 09:14:27 2010
(==) Using config file: "/etc/X11/xorg.conf"
(==) Using system config directory "/usr/share/X11/xorg.conf.d"
(II) [KMS] Kernel modesetting enabled.
(II) [KMS] Kernel modesetting enabled.
(II) [KMS] Kernel modesetting enabled.
(EE) RADEON(1):  reusing fd for second head

Backtrace:
0: Xorg (xorg_backtrace+0x28) [0x4a0fa8]
1: Xorg (0x400000+0x60fcd) [0x460fcd]
2: /lib/libpthread.so.0 (0x7fe8313a7000+0xfb40) [0x7fe8313b6b40]
3: Xorg (0x400000+0xbb22f) [0x4bb22f]
4: Xorg (0x400000+0x2c2d9) [0x42c2d9]
5: Xorg (0x400000+0x2184b) [0x42184b]
6: /lib/libc.so.6 (__libc_start_main+0xfe) [0x7fe830312d8e]
7: Xorg (0x400000+0x213d9) [0x4213d9]
Segmentation fault at address 0x4

Caught signal 11 (Segmentation fault). Server aborting

Please consult the The X.Org Foundation support
         at http://wiki.x.org
 for help.
Please also check the log file at "/var/log/Xorg.0.log" for additional information.

 ddxSigGiveUp: Closing log
Exit 1

xorg.conf:

Section "ServerLayout"
	Identifier   "Ian"
	Screen       "Screen Right" 0 0
	Screen       "Screen Middle"  LeftOf "Screen Right"
	Screen       "Screen Left"  LeftOf "Screen Middle"
	Option       "Xinerama"
EndSection

Section "Screen"
	Identifier "Screen Right"
	Device     "Device Right"
	# this isn't absolutely necessary but it helps window placement
	SubSection "Display"
		Virtual 1600 1200
	EndSubSection
EndSection

Section "Screen"
	Identifier "Screen Middle"
	Device     "Device Middle"
	# this isn't absolutely necessary but it helps window placement
	SubSection "Display"
		Virtual 1600 1200
	EndSubSection
EndSection

Section "Screen"
	Identifier "Screen Left"
	Device     "Device Left"
	# this isn't absolutely necessary but it helps window placement
	SubSection "Display"
		Virtual 1600 1200
	EndSubSection
EndSection

Section "Device"
	Identifier  "Device Right"
	Driver      "radeon"
	VendorName  "ATI Technologies Inc"
	BoardName   "FireMV 2250"
	BusID       "PCI:5:0:0"
	Option	    "ZaphodHeads" "DVI-0"
	Option "AccelMethod" "XAA"
	Screen	    0
EndSection

Section "Device"
	Identifier  "Device Middle"
	Driver      "radeon"
	VendorName  "ATI Technologies Inc"
	BoardName   "FireMV 2250"
	BusID       "PCI:5:0:0"
	Option	    "ZaphodHeads" "DVI-1"
	Option "AccelMethod" "XAA"
	Screen	    1
EndSection

Section "Device"
	Identifier  "Device Left"
	Driver      "radeon"
	VendorName  "ATI Technologies Inc"
	BoardName   "FireMV 2250"
	BusID       "PCI:4:0:0"
	Option	    "ZaphodHeads" "DVI-2"
	Option "AccelMethod" "XAA"
	Screen	    0
EndSection

Section "Device"
	Identifier  "Device Unused"
	Driver      "radeon"
	VendorName  "ATI Technologies Inc"
	BoardName   "FireMV 2250"
	BusID       "PCI:4:0:0"
	Option	    "ZaphodHeads" "DVI-3"
	Option "AccelMethod" "XAA"
	Screen	    1
EndSection

after recent update my X also started to segfault with same message in dmesg.
xorg-server is 1.9.3;
mesa, libdrm, xf86-video-ati are most recent git;
kernel is 2.6.36.2 on SMP x86_64;
card is discrete "ATI Technologies Inc Mobility Radeon X2300"/RV515 on r300g

backtrace from kdm.log:
"Errors from xkbcomp are not fatal to the X server

Backtrace:
0: /usr/bin/X (xorg_backtrace+0x2d) [0x483fa5]
1: /usr/bin/X (0x400000+0x53732) [0x453732]
2: /lib/libpthread.so.0 (0x39dcc00000+0xfe60) [0x39dcc0fe60]
3: /usr/bin/X (miPointerUpdateSprite+0x14c) [0x44d883]
4: /usr/bin/X (0x400000+0x4da09) [0x44da09]
5: /usr/bin/X (0x400000+0x87770) [0x487770]
6: /usr/bin/X (0x400000+0x11c72a) [0x51c72a]
7: /usr/bin/X (0x400000+0x85890) [0x485890]
8: /usr/bin/X (BlockHandler+0x42) [0x42e2f1]
9: /usr/bin/X (WaitForSomething+0x23d) [0x44e2bb]
10: /usr/bin/X (0x400000+0x2af44) [0x42af44]
11: /usr/bin/X (0x400000+0x21638) [0x421638]
12: /lib/libc.so.6 (__libc_start_main+0xfd) [0x39dc01ecdd]
13: /usr/bin/X (0x400000+0x210f9) [0x4210f9]
Segmentation fault at address 0x10

Fatal server error:
Caught signal 11 (Segmentation fault). Server aborting"
------------------------------------------------------

after writing the above and forgeting to post it from another machine i found out that offender is not xf86-video-ati, but, in fact, xf86-input-evdev-2.5.99.902. with downgrading to xf86-input-evdev-2.5 there are no more segfaults (it were 100% segfaulting if i would touch a touchpad).
i can't say if dmesg error message have something to do with it but it's definitely were poping out in log right before X death every time.

Mass closure: This bug has been untouched for more than six years, and is not
obviously still valid. Please reopen this bug or file a new report if you continue to experience issues with current releases.