[Mesa-dev] segfault in dri2 state tracker with TFP

[Dave Airlie]

On Sun, May 30, 2010 at 5:52 PM, Dave Airlie <airlied at gmail.com> wrote:
> Running texture_from_pixmap in xdemos against r300g
>
> Program received signal SIGSEGV, Segmentation fault.
> dri2_invalidate_drawable (dPriv=0x8066990) at dri2.c:57
> 57         struct dri_context *ctx = dri_context(dPriv->driContextPriv);
> Missing separate debuginfos, use: debuginfo-install
> expat-2.0.1-8.fc12.i686 glew-1.5.4-1.fc14.i686 glibc-2.11.1-6.i686
> libX11-1.3-1.fc12.i686 libXdamage-1.1.2-1.fc12.i686
> libXext-1.1-2.fc12.i686 libXfixes-4.0.4-1.fc12.i686
> libXxf86vm-1.1.0-1.fc12.i686 libdrm-2.4.21-0.1.fc14.i686
> libgcc-4.4.3-4.fc12.i686 libselinux-2.0.90-5.fc12.i686
> libstdc++-4.4.3-4.fc12.i686 libxcb-1.5-1.fc12.i686
> mesa-libGLU-7.7-4.fc12.i686
> (gdb) bt
> #0  dri2_invalidate_drawable (dPriv=0x8066990) at dri2.c:57
> #1  0xb7f9ee73 in dri2_bind_tex_image (dpy=0x804b008, drawable=75497476,
>    buffer=8414, attrib_list=0x0) at dri2_glx.c:581
> #2  0xb7f7dab6 in __glXBindTexImageEXT (dpy=0x804b008, drawable=75497476,
>    buffer=8414, attrib_list=0x0) at glxcmds.c:3098
> #3  0x0804978c in BindPixmapTexture (argc=1, argv=0xbffff304)
>    at texture_from_pixmap.c:257
> #4  main (argc=1, argv=0xbffff304) at texture_from_pixmap.c:391
>
> dPriv->driContextPriv is NULL and dri_context macro derferences it.
>
> attached patch "fixes" it but not sure if we want drI_context macro to
> catch this or whether something else is doing something wrong and
> causing this.

I've no idea what the code in dri2_invalidate_drawable is for, the
intel + nouveau legacy drivers don't seem to need this extra codepath
and just call the generic invalidate.

This patch + a patch to dri_util.c to always initialise
pdp->driContextPriv to NULL in driCreateNewDrawable works for me, but
it would be nice to know why the dri2 st cares about context in this
place.

Dave.