(In reply to Emil Velikov from comment #13)
>  - Invalid memory access in various modules - invalid reads in various steam
> runtime components, alarming number of invalid writes in i965_dri.so.
> 
> The latter one perhaps should be looked into closer ?

Probably not, that is just valgrind not understanding GEM and its ioctls. You
need to use a libdrm compiled with --enable-valgrind to suppress the false
positives.