Created attachment 107907 [details]
Xorg.0.log

On Debian unstable, I get a segfault in the i965 mesa driver. This causes a large number of applications to fail, including anything that uses the webcam. The glxgears test program segfaults on startup. The stack trace from the core file is as follows:

#0  get_stencil_miptree (irb=<optimized out>)
    at ../../../../../../../src/mesa/drivers/dri/i965/brw_misc_state.c:225
225	../../../../../../../src/mesa/drivers/dri/i965/brw_misc_state.c: No such file or directory.
(gdb) where
#0  get_stencil_miptree (irb=<optimized out>)
    at ../../../../../../../src/mesa/drivers/dri/i965/brw_misc_state.c:225
#1  brw_workaround_depthstencil_alignment (brw=0x7fafe0819038, 
    clear_mask=clear_mask@entry=18)
    at ../../../../../../../src/mesa/drivers/dri/i965/brw_misc_state.c:241
#2  0x00007fafdb37e152 in brw_clear (ctx=0x7fafe0819038, mask=18)
    at ../../../../../../../src/mesa/drivers/dri/i965/brw_clear.c:235
#3  0x000000000040255e in ?? ()
#4  0x0000000000401d54 in ?? ()
#5  0x00007fafdf2b0b45 in __libc_start_main (main=0x4018d0, argc=1, 
    argv=0x7fff7a5b2628, init=<optimized out>, fini=<optimized out>, 
    rtld_fini=<optimized out>, stack_end=0x7fff7a5b2618) at libc-start.c:287
#6  0x0000000000402332 in ?? ()



Before crashing, glxgears prints the following:
"Running synchronized to the vertical refresh.  The framerate should be
approximately the same as the monitor refresh rate." The glxgears window never appears.

I am on a Dell Inspiron laptop. The crash occurs regardless of whether my VGA external monitor is attached.

I am on kernel 3.16-2-amd64. I have observed the problem with mesa versions 10.2.8-1, 10.3.0-2, and 10.3.1-1.