Hello,

I'm sometimes seeing the following crash:

#0  0x00007f0da1d11267 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:55
#1  0x00007f0da1d12eca in __GI_abort () at abort.c:89
#2  0x000055cbcba3108e in OsAbort () at ../../os/utils.c:1342
#3  0x000055cbcba36b23 in AbortServer () at ../../os/log.c:807
#4  0x000055cbcba3793d in FatalError (f=f@entry=0x55cbcba63270 "Caught signal %d (%s). Server aborting\n") at ../../os/log.c:945
#5  0x000055cbcba2e9ee in OsSigHandler (signo=11, sip=<optimised out>, unused=<optimised out>) at ../../os/osinit.c:147
#6  <signal handler called>
#7  0x000055cbcc7f0670 in ?? ()
#8  0x00007f0d9e138db3 in copy_overlap (sna=sna@entry=0x7f0da3d13000, alu=<optimised out>, draw=draw@entry=0x7ffc84c25e90, 
    bo=bo@entry=0x55cbcc9d9c50, src_dx=src_dx@entry=0, src_dy=<optimised out>, dst_dx=0, dst_dy=0, box=0x7ffc84c25e70, n=1, extents=0x7ffc84c25bf0)
    at ../../../src/sna/sna_render.c:2158
#9  0x00007f0d9e13d5a2 in sna_render_copy_boxes__overlap (sna=sna@entry=0x7f0da3d13000, alu=alu@entry=3 '\003', draw=draw@entry=0x7ffc84c25e90, 
    bo=bo@entry=0x55cbcc9d9c50, src_dx=src_dx@entry=0, src_dy=src_dy@entry=0, dst_dx=0, dst_dy=0, box=0x7ffc84c25e70, n=1, extents=0x7ffc84c25bf0)
    at ../../../src/sna/sna_render.c:2209
#10 0x00007f0d9e19dea8 in gen6_render_copy_boxes (sna=0x7f0da3d13000, alu=<optimised out>, src=0x7ffc84c25e90, src_bo=0x55cbcc9d9c50, 
    src_dx=<optimised out>, src_dy=<optimised out>, dst=0x55cbcc9d1d50, dst_bo=0x55cbcc9d9c50, dst_dx=0, dst_dy=0, box=0x7ffc84c25e70, n=1, flags=17)
    at ../../../src/sna/gen6_render.c:2800
#11 0x00007f0d9e1b769f in __sna_dri2_copy_region (sna=0x7f0da3d13000, draw=<optimised out>, region=<optimised out>, src=<optimised out>, 
    dst=<optimised out>, flags=2) at ../../../src/sna/sna_dri2.c:1319
#12 0x000055cbcb9fbbcc in dri2_copy_region (pDraw=pDraw@entry=0x55cbcc916730, pRegion=pRegion@entry=0x55cbcc7f0210, pDest=0x55cbcc8694a0, 
    pSrc=0x55cbcc48bfe0) at ../../../../hw/xfree86/dri2/dri2.c:871
#13 0x000055cbcb9fc2ee in DRI2CopyRegion (pDraw=0x55cbcc916730, pRegion=0x55cbcc7f0210, dest=0, src=1) at ../../../../hw/xfree86/dri2/dri2.c:912
#14 0x000055cbcb9fe6c3 in ProcDRI2CopyRegion (client=0x55cbcc64b9c0) at ../../../../hw/xfree86/dri2/dri2ext.c:332
#15 ProcDRI2Dispatch (client=0x55cbcc64b9c0) at ../../../../hw/xfree86/dri2/dri2ext.c:609
#16 0x000055cbcb8ce18f in Dispatch () at ../../dix/dispatch.c:432
#17 0x000055cbcb8d234b in dix_main (argc=11, argv=0x7ffc84c261b8, envp=<optimised out>) at ../../dix/main.c:298
#18 0x00007f0da1cfca40 in __libc_start_main (main=0x55cbcb8bc690 <main>, argc=11, argv=0x7ffc84c261b8, init=<optimised out>, fini=<optimised out>, 
    rtld_fini=<optimised out>, stack_end=0x7ffc84c261a8) at libc-start.c:289
#19 0x000055cbcb8bc6c9 in _start ()

My graphics chips is (in a Lenovo X220): Integrated Graphics Chipset: Intel(R) HD Graphics 3000

Other Ubuntu users are seeing the same thing and more info can be found here: https://errors.ubuntu.com/problem/67526ca76c90e73ebb6a6774e6e6b0dda99f2428

If you have any more questions, let me know.

Keep up the great work! :)