My X server crashed with a bus error in radeon_drv.so shortly after KDE has started up. Excerpt from Xorg.1.log: ============= [ 127.445] (EE) [ 127.445] (EE) Backtrace: [ 127.445] (EE) 0: X (xorg_backtrace+0x34) [0x5929f4] [ 127.445] (EE) 1: X (0x400000+0x1967e9) [0x5967e9] [ 127.445] (EE) 2: /lib64/libpthread.so.0 (0x7f65e6338000+0x11070) [0x7f65e6349070] [ 127.446] (EE) 3: /lib64/libc.so.6 (0x7f65e4f98000+0x12ecbd) [0x7f65e50c6cbd] [ 127.446] (EE) 4: /usr/lib64/xorg/modules/drivers/radeon_drv.so (0x7f65e3fd0000+0x33232) [0x7f65e4003232] [ 127.446] (EE) 5: /usr/lib64/xorg/modules/libexa.so (0x7f65e3ba0000+0xabb1) [0x7f65e3baabb1] [ 127.446] (EE) 6: /usr/lib64/xorg/modules/libexa.so (0x7f65e3ba0000+0xacf9) [0x7f65e3baacf9] [ 127.446] (EE) 7: X (miCopyRegion+0x17a) [0x571a5a] [ 127.446] (EE) 8: X (miDoCopy+0x39a) [0x571f7a] [ 127.446] (EE) 9: /usr/lib64/xorg/modules/libexa.so (0x7f65e3ba0000+0x8dc6) [0x7f65e3ba8dc6] [ 127.446] (EE) 10: X (0x400000+0x11d401) [0x51d401] [ 127.446] (EE) 11: X (0x400000+0xd9e3d) [0x4d9e3d] [ 127.446] (EE) 12: X (0x400000+0xdb03d) [0x4db03d] [ 127.446] (EE) 13: X (0x400000+0x3ab8e) [0x43ab8e] [ 127.446] (EE) 14: X (0x400000+0x29a56) [0x429a56] [ 127.446] (EE) 15: /lib64/libc.so.6 (__libc_start_main+0xed) [0x7f65e4fbc64d] [ 127.446] (EE) 16: X (0x400000+0x29dd9) [0x429dd9] [ 127.446] (EE) [ 127.446] (EE) Bus error at address 0x7f65d76bd7f0 [ 127.446] (EE) Fatal server error: [ 127.446] (EE) Caught signal 7 (Bus error). Server aborting [ 127.446] (EE) [ 127.446] (EE) Please consult the The X.Org Foundation support at http://wiki.x.org for help. [ 127.446] (EE) Please also check the log file at "/var/log/Xorg.1.log" for additional information. [ 127.446] (EE) [ 127.446] (II) AIGLX: Suspending AIGLX clients for VT switch [ 127.459] (EE) Server terminated with error (1). Closing log file. ============= Reproducible: Sometimes Steps to Reproduce: 1. Log in via kdm or start X server from the commandline and start KDE 2. Wait a bit Actual Results: The X server crashes. If I logged in via kdm, I am back at the login screen. If I started the X server from the commandline, I am back at the commandline. Expected Results: X server should keep running until the last X client disconnects. Installed version x11-drivers/xf86-video-ati is 7.2.0. Kernel version used is 3.11 (vanilla). This does not always happen, but when it happens, it will keep happening until I physically power cycle the machine. (Meaning just shutting it down and letting it power down via ACPI is not enough, I have to actually physically remove the power.)
Created attachment 361038 [details] X server log file from /var/log/Xorg.1.log
Please also get a full stack trace as described in http://www.x.org/wiki/Development/Documentation/ServerDebugging and open a bug report upstream at https://bugs.freedesktop.org/ (and provide the link here). The packages that need to be built with CFLAGS="-g" to get a meaningful stack trace are xf86-video-ati and xorg-server.
There's not really anything Gentoo developers can do to solve this. Please file a bug upstream https://bugs.freedesktop.org/enter_bug.cgi?product=DRI if the problem persists.