On Fri, 2019-04-12 at 14:45 +0200, Alexander Potapenko wrote: > This config option adds the possibility to initialize newly allocated > pages and heap objects with zeroes. This is needed to prevent possible > information leaks and make the control-flow bugs that depend on > uninitialized values more deterministic. > > Initialization is done at allocation time at the places where checks for > __GFP_ZERO are performed. We don't initialize slab caches with > constructors or SLAB_TYPESAFE_BY_RCU to preserve their semantics. > > For kernel testing purposes filling allocations with a nonzero pattern > would be more suitable, but may require platform-specific code. To have > a simple baseline we've decided to start with zero-initialization. > > No performance optimizations are done at the moment to reduce double > initialization of memory regions. Sounds like this has already existed in some degree, i.e., CONFIG_PAGE_POISONING_ZERO
