On Mar 29, 2005, at 4:35 AM, macallan18@earthlink.net wrote:

> #0  0x0000000040a132a4 in pthread__lock_ras_end ()
>    from /usr/lib/libpthread.so.0
> #1  0x0000000000000008 in ?? ()
> #2  0x0000000040a134e8 in pthread_spinlock () from /usr/lib/ 
> libpthread.so.0
> #3  0x0000000040a0bb38 in pthread_sigmask () from /usr/lib/ 
> libpthread.so.0
> #4  0x000000000016c598 in xf86BlockSIGIO ()
> #5  0x000000000014d650 in xf86SigioReadInput ()
> #6  0x000000000016c248 in xf86SIGIO ()
> #7  <signal handler called>
> #8  0xffffaba100000000 in ?? ()
> #9  0x0000000000000008 in ?? ()
> #10 0x000000000016c5dc in xf86UnblockSIGIO ()
> #11 0x000000000016c248 in xf86SIGIO ()
> #12 <signal handler called>

It looks to me like the X server is doing things in a signal handler  
that it should not do.  In particular, note how it unblocked SIGIO  
while it is currently handling a SIGIO ... then another SIGIO comes  
in and all hell breaks loose.

-- thorpej