Xorg signal 11's spontaneously

[Adam Jackson]

Dennis Jacobfeuerborn wrote:
> Dennis Jacobfeuerborn wrote:
>> In the last 10 days Xorg crashed three times with a signal 11 
>> spontaneously. This is the backtrace I found in the logfile:
>>
>> Backtrace:
>> 0: /usr/bin/Xorg(xf86SigHandler+0x87) [0x80b6d07]
>> 1: [0x49a420]
>> 2: /usr/lib/xorg/modules/libfb.so [0x134b81]
>> 3: /usr/lib/xorg/modules/libfb.so [0x13c80c]
>> 4: /usr/lib/xorg/modules/libfb.so(fbCompositeGeneral+0x855) [0x13a4e5]
>> 5: /usr/lib/xorg/modules/libfb.so(fbComposite+0x1cd) [0x1433ad]
>> 6: /usr/lib/xorg/modules/libxaa.so(XAAComposite+0x261) [0x81f001]
>> 7: /usr/bin/Xorg [0x8156d06]
>> 8: /usr/bin/Xorg [0x8153915]
>> 9: /usr/bin/Xorg(CompositePicture+0x153) [0x8140a13]
>> 10: /usr/bin/Xorg [0x814687c]
>> 11: /usr/bin/Xorg [0x8143bd5]
>> 12: /usr/bin/Xorg(Dispatch+0x19a) [0x80869ba]
>> 13: /usr/bin/Xorg(main+0x485) [0x806e3e5]
>> 14: /lib/libc.so.6(__libc_start_main+0xdc) [0x4cd7e4]
>> 15: /usr/bin/Xorg(FontFileCompleteXLFD+0xbd) [0x806d721]
>>
>> Fatal server error:
>> Caught signal 11.  Server aborting
>>
>> All three crashes happened when I was loading a page in Firefox and 
>> after the nightly Firefox builds got switched to Cairo as their 
>> rendering backend so I wonder if Cairo could somehow trigger this.
>>
>> I'm running Fedora Core Rawhide with the following Xorg packages:
>> xorg-x11-server-Xorg-1.0.99.901-5
>> xorg-x11-drv-nv-1.1.1-2
>>
>> I'm using the open source nv driver with the AccelMethod set to EXA 
>> and the 'load "dri"' and 'load "glx"' lines commented out.

Neither DRI nor EXA matter at all to the nv driver, which supports neither.

> Just happened again and the backtrace looks similar to the one above. If 
> I can do something to provide better information to debug this please 
> tell me.

Install the debuginfo packages, ssh in from another machine, su, attach 
gdb to X, 'handle SIGPIPE nostop', and 'cont'.  When the server 
segfaults, 'bt f' should now give you useful backtrace info.

May also be related to a crasher recently fixed for x4a4 glyphs; I'll 
backpatch that into rawhide and stable shortly.

- ajax