PID: 18282 (Xorg)
           UID: 1000 (USER_NAME)
           GID: 1000 (USER_NAME)
        Signal: 6 (ABRT)
     Timestamp: Sat 2015-02-28 11:07:07 PST (2min 37s ago)
  Command Line: /usr/lib/xorg-server/Xorg -nolisten tcp vt01 :1 vt1 -auth /tmp/serverauth.Zxaw092jw3
    Executable: /usr/lib/xorg-server/Xorg
 Control Group: /user.slice/user-1000.slice/session-c1.scope
          Unit: session-c1.scope
         Slice: user-1000.slice
       Session: c1
     Owner UID: 1000 (USER_NAME)
       Boot ID: fd80b330164645078c79ed36691036de
    Machine ID: MACHINE_ID
      Hostname: HOST_NAME
      Coredump: /var/lib/systemd/coredump/core.Xorg.1000.fd80b330164645078c79ed36691036de.18282.1425150427000000.lz4
       Message: Process 18282 (Xorg) of user 1000 dumped core.

GNU gdb (GDB) 7.9

--- snip ---

Reading symbols from /usr/lib/xorg-server/Xorg...done.
[New LWP 18282]
[New LWP 18284]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib/libthread_db.so.1".
Core was generated by `/usr/lib/xorg-server/Xorg -nolisten tcp vt01 :1 vt1 -auth /tmp/serverauth.Zxaw0'.
Program terminated with signal SIGABRT, Aborted.
#0  0x00007f6f1c8564b7 in raise () from /usr/lib/libc.so.6
(gdb) where
#0  0x00007f6f1c8564b7 in raise () from /usr/lib/libc.so.6
#1  0x00007f6f1c85788a in abort () from /usr/lib/libc.so.6
#2  0x00007f6f1c894993 in __libc_message () from /usr/lib/libc.so.6
#3  0x00007f6f1c899dee in malloc_printerr () from /usr/lib/libc.so.6
#4  0x00007f6f1c89a5cb in _int_free () from /usr/lib/libc.so.6
#5  0x0000000000574dc0 in miPolyFillArc (pDraw=<optimized out>, pGC=<optimized out>, narcs_all=<optimized out>, parcs=<optimized out>)
    at mifillarc.c:694
#6  0x000000000051a547 in damagePolyFillArc (pDrawable=0x215c7b0, pGC=0x1d515d0, nArcs=1, pArcs=0x213a780) at damage.c:1229
#7  0x00000000004354a4 in ProcPolyFillArc (client=0x2132700) at dispatch.c:1906
#8  0x0000000000438a17 in Dispatch () at dispatch.c:432
#9  0x000000000043cb8b in dix_main (argc=8, argv=0x7ffff4a274d8, envp=<optimized out>) at main.c:298
#10 0x00007f6f1c843800 in __libc_start_main () from /usr/lib/libc.so.6
#11 0x0000000000427039 in _start ()