Bug 91756

Running piglit tests against mesa-11.0-rc1 package in debian experimental
https://tracker.debian.org/news/707424

i have one test segfaulting the X server consistently.

HW is Ivy Bridge laptop with an additional  GK107 (NVE7) kepler.

Xserver version: 1.17.2 (from debian sid)
mesa: 11.0-rc1 (from debian experimental)
libdrm: 2.4.64
kernel: 4.1.0

Test is ran via:
logging into X locally

then via ssh:
export DISPLAY=:0
xrandr --setprovideroffloadsink nouveau Intel
export DRI_PRIME=1
Verifying with
glxinfo | grep nouveau

# just run the problematic test
bin/glean -t vertProg1

That immediately crashes the X server with a segfault

an attached gdb show following backtrace:
#0  exaHWCopyNtoN (pSrcDrawable=pSrcDrawable@entry=0x55920c1fbb20, 
    pDstDrawable=pDstDrawable@entry=0x55920c262620, pGC=pGC@entry=0x55920c2627b0, 
    pbox=pbox@entry=0x7ffdc7dee340, nbox=nbox@entry=1, dx=dx@entry=13, dy=31, reverse=0, 
    upsidedown=0) at ../../exa/exa_accel.c:424
#1  0x00007fb5e5baedcf in exaCopyNtoN (pSrcDrawable=pSrcDrawable@entry=0x55920c1fbb20, 
    pDstDrawable=0x55920c262620, pGC=0x55920c2627b0, pbox=pbox@entry=0x7ffdc7dee340, 
    nbox=nbox@entry=1, dx=13, dy=31, reverse=0, upsidedown=0, bitplane=0, closure=0x0)
    at ../../exa/exa_accel.c:581
#2  0x000055920b6eebbc in miCopyRegion (pSrcDrawable=pSrcDrawable@entry=0x55920c1fbb20, 
    pDstDrawable=pDstDrawable@entry=0x55920c262620, pGC=pGC@entry=0x55920c2627b0, 
    pDstRegion=pDstRegion@entry=0x7ffdc7dee340, dx=dx@entry=13, dy=dy@entry=31, 
    copyProc=0x7fb5e5baed00 <exaCopyNtoN>, bitPlane=0, closure=0x0) at ../../mi/micopy.c:121
#3  0x000055920b6ef236 in miDoCopy (pSrcDrawable=0x55920c1fbb20, pDstDrawable=0x55920c262620, 
    pGC=0x55920c2627b0, xIn=13, yIn=31, widthSrc=100, heightSrc=100, xOut=0, yOut=0, 
    copyProc=0x7fb5e5baed00 <exaCopyNtoN>, bitPlane=0, closure=0x0) at ../../mi/micopy.c:296
#4  0x00007fb5e5bad355 in exaCopyArea (pSrcDrawable=<optimized out>, pDstDrawable=<optimized out>, 
    pGC=<optimized out>, srcx=<optimized out>, srcy=<optimized out>, width=<optimized out>, 
    height=100, dstx=0, dsty=0) at ../../exa/exa_accel.c:608
#5  0x000055920b69a281 in damageCopyArea (pSrc=0x55920c1fbb20, pDst=0x55920c262620, 
    pGC=0x55920c2627b0, srcx=0, srcy=<optimized out>, width=100, height=100, dstx=0, dsty=0)
    at ../../../miext/damage/damage.c:764
#6  0x00007fb5e7e0966f in nouveau_dri2_copy_region2 (pScreen=<optimized out>, pDraw=0x55920c1fbb20, 
    pRegion=0x7ffdc7dee5c0, pDstBuffer=0x55920c262050, pSrcBuffer=<optimized out>)
    at ../../src/nouveau_dri2.c:202
#7  0x000055920b6e0059 in dri2_copy_region (pDraw=pDraw@entry=0x55920c1fbb20, 
    pRegion=pRegion@entry=0x7ffdc7dee5c0, pDest=0x55920c262050, pSrc=0x55920c262080)
    at ../../../../hw/xfree86/dri2/dri2.c:869
#8  0x000055920b6e086e in DRI2CopyRegion (pDraw=pDraw@entry=0x55920c1fbb20, 
    pRegion=pRegion@entry=0x7ffdc7dee5c0, dest=dest@entry=7, src=src@entry=0)
    at ../../../../hw/xfree86/dri2/dri2.c:912
#9  0x000055920b6e0ba0 in do_get_buffers (pDraw=<optimized out>, width=width@entry=0x7ffdc7dee648, 
    height=height@entry=0x7ffdc7dee650, attachments=<optimized out>, 
    attachments@entry=0x55920c23f1dc, count=2, out_count=out_count@entry=0x7ffdc7dee658, 
    has_format=1) at ../../../../hw/xfree86/dri2/dri2.c:631
#10 0x000055920b6e0d7b in DRI2GetBuffersWithFormat (pDraw=<optimized out>, 
    width=width@entry=0x7ffdc7dee648, height=height@entry=0x7ffdc7dee650, 
    attachments=attachments@entry=0x55920c23f1dc, count=<optimized out>, 
    out_count=out_count@entry=0x7ffdc7dee658) at ../../../../hw/xfree86/dri2/dri2.c:671
#11 0x000055920b6e24f0 in ProcDRI2GetBuffersWithFormat (client=0x55920c243200)
    at ../../../../hw/xfree86/dri2/dri2ext.c:309
#12 ProcDRI2Dispatch (client=0x55920c243200) at ../../../../hw/xfree86/dri2/dri2ext.c:611
#13 0x000055920b5b307f in Dispatch () at ../../dix/dispatch.c:432
#14 0x000055920b5b71cb in dix_main (argc=10, argv=0x7ffdc7dee878, envp=<optimized out>)
    at ../../dix/main.c:298
#15 0x00007fb5ec4d4b45 in __libc_start_main (main=0x55920b5a1590 <main>, argc=10, 
    argv=0x7ffdc7dee878, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, 
    stack_end=0x7ffdc7dee868) at libc-start.c:287
#16 0x000055920b5a15be in _start ()