[PATCH 1/4] mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options

[Kees Cook]

On Wed, May 8, 2019 at 8:38 AM Alexander Potapenko <glider at google.com> wrote:
> The new options are needed to prevent possible information leaks and
> make control-flow bugs that depend on uninitialized values more
> deterministic.

I like having this available on both alloc and free. This makes it
much more configurable for the end users who can adapt to their work
loads, etc.

> Linux build with -j12, init_on_free=1:  +24.42% sys time (st.err 0.52%)
> [...]
> Linux build with -j12, init_on_alloc=1: +0.57% sys time (st.err 0.40%)

Any idea why there is such a massive difference here? This seems to
high just for cache-locality effects of touching all the freed pages.

-- 
Kees Cook