#0  0x00b18424 in __kernel_vsyscall ()
#1  0x007449f2 in __lll_lock_wait_private () at
../nptl/sysdeps/unix/sysv/linux/i386/i486/lowlevellock.S:98
#2  0x006d25dd in _L_lock_52 () from /lib/libc.so.6
#3  0x006cc223 in ptmalloc_lock_all () at arena.c:288
#4  0x006fb427 in __libc_fork () at ../nptl/sysdeps/unix/sysv/linux/fork.c:95
#5  0x008bc8b1 in __fork () at ../nptl/sysdeps/unix/sysv/linux/pt-fork.c:26
#6  0x080a4140 in xorg_backtrace_gdb () at backtrace.c:62
#7  xorg_backtrace () at backtrace.c:120