bump: Xorg segfaults on XOpenDisplay multi thread

[Bill Crawford]

On Sunday 28 December 2008 08:56:50 Matan Drori wrote:
> Bump, adding some backtraces:
> Dump 1:
> #0  _X11TransWritev (ciptr=0x0, buf=0x2000000001b96720, size=1) at
> ../../lib/xtrans/Xtrans.c:911
> #1  0x2000000000093910 in _XSendClientPrefix (dpy=<value optimized out>,
> client=<value optimized out>, auth_proto=0x0, auth_string=0x0,
> prefix=0x2000000001b96784) at ConnDis.c:572
> #2  0x20000000000c4640 in XOpenDisplay (display=<value optimized out>)
> at OpenDis.c:295
> #3  0x4000000000001580 in ThreadMain_OpenDisplayAndStartTest (num=0x1)
> at ../../thread.cpp:37
> #4  0x200000000027d5d0 in start_thread () from /lib/libpthread.so.0
> #5  0x20000000007cb730 in __clone2 () from /lib/libc.so.6.1
> Dump 2:
> #0  0x200000000070f350 in malloc_consolidate () from /lib/libc.so.6.1
> #1  0x2000000000714830 in _int_malloc () from /lib/libc.so.6.1
> #2  0x2000000000716ef0 in calloc () from /lib/libc.so.6.1
> #3  0x20000000000c4530 in XOpenDisplay (display=<value optimized out>)
> at OpenDis.c:262
> #4  0x4000000000001580 in ThreadMain_OpenDisplayAndStartTest (num=0x2)
> at ../../thread.cpp:37
> #5  0x200000000027d050 in start_thread () from /lib/libpthread.so.0
> #6  0x20000000007cb730 in __clone2 () from /lib/libc.so.6.1
>
> i explored this topic for quite a while, when i debug it i see memory
> corruptions every time it crashes. memory corruptions doesn't always occur
> at the same place which makes it even harder and more confusing.

Well, the ciptr=0x0 looks suspicious, to say the least. But it smells like you 
have an issue with thread safety somewhere underneath libX11, like in the C 
library. Did you link against libpthread?