Running dom/canvas/test/webgl-conf/generated/test_conformance__extensions__oes-texture-float-linear.html under valgrind, I see a number of invalid writes reported, following by other signs of memory corruption and a crash.

Vincent, in the context of bug 1285531, can you take a look at this and see if it helps us? May have to setup valgrind and reproduce what David is seeing.

This is also reproducable just by loading the file dom/canvas/test/webgl-conf/checkout/conformance/extensions/oes-texture-float-linear.html , which allows skipping all the mochitest/marionnette junk (which is extremely slow).

... though I see this only on my machine with proprietary nvidia drivers, and not on the machine with Intel drivers...

This also happens on other tests, such as: oes-texture-float-linear.html (the original test reported) oes-texture-float-with-canvas.html oes-texture-float-with-image-data.html: oes-texture-float.html oes-texture-half-float-linear.html oes-texture-half-float-with-canvas.html oes-texture-half-float-with-image-data.html oes-texture-half-float.html (I tried a few others, but couldn't get it to happen elsewhere.)

David, what's your machine/driver configuration?

Ubuntu 16.04, with the driver nvidia-304-updates version 304.131-0ubuntu3. about:support says the GPU is "NVIDIA Corporation - Quadro NVS 295/PCIe/SSE2" with driver version "3.3.0 NVIDIA 304.131".

(In reply to Milan Sreckovic [:milan] from comment #3) > Vincent, in the context of bug 1285531, can you take a look at this and see > if it helps us? May have to setup valgrind and reproduce what David is > seeing. Sure. I will try to setup environment.

I tried those tests in Ubuntu 14.04, with the GT210 driver nvidia-304-updates version 304.131 under valgrind. The thing is I can't reproduce crash issues by many times. I followed [1] to setup and run command under valgrind. [1]: https://developer.mozilla.org/en-US/docs/Mozilla/Testing/Valgrind