(gdb) bt
#0  0xffffe410 in __kernel_vsyscall ()
#1  0xb792c66b in poll () from /lib/libc.so.6
#2  0xb79f1c83 in _XWaitForReadable () from /usr/lib/libX11.so.6
#3  0x00000001 in ?? ()
#4  0xffffffff in ?? ()
#5  0xb7a9bb24 in ?? () from /usr/lib/libX11.so.6
#6  0x08137580 in ?? ()
#7  0xb7a9bb24 in ?? () from /usr/lib/libX11.so.6
#8  0x08137580 in ?? ()
#9  0x00000000 in ?? ()