On Tue, Feb 5, 2019 at 10:04 PM Andrew Morton <a...@linux-foundation.org> wrote: > > On Thu, 31 Jan 2019 21:15:17 -0800 Dan Williams <dan.j.willi...@intel.com> > wrote: > > > +config SHUFFLE_PAGE_ALLOCATOR > > + bool "Page allocator randomization" > > + default SLAB_FREELIST_RANDOM && ACPI_NUMA > > + help > > SLAB_FREELIST_RANDOM is default n, so this patchset won't get much > runtime testing. > > How about you cook up a (-mm only) patch which makes the kernel default > to SLAB_FREELIST_RANDOM=y, SHUFFLE_PAGE_ALLOCATOR=y (or whatever) to > ensure we get a decent amount of runtime testing? Then I can hold that > in -mm (and -next) until we get bored of it?
I love this plan. :) FWIW, distros have enabled it by default for a while. Here's Ubuntu, for example: $ grep SLAB_FREELIST /boot/config-4.1* /boot/config-4.15.0-45-generic:CONFIG_SLAB_FREELIST_RANDOM=y /boot/config-4.15.0-45-generic:CONFIG_SLAB_FREELIST_HARDENED=y /boot/config-4.18.0-13-generic:CONFIG_SLAB_FREELIST_RANDOM=y /boot/config-4.18.0-13-generic:CONFIG_SLAB_FREELIST_HARDENED=y /boot/config-4.18.0-14-generic:CONFIG_SLAB_FREELIST_RANDOM=y /boot/config-4.18.0-14-generic:CONFIG_SLAB_FREELIST_HARDENED=y and Fedora too: $ curl -s 'https://git.kernel.org/pub/scm/linux/kernel/git/jwboyer/fedora.git/patch/fedora/configs/kernel-4.16.12-x86_64.config?h=f26' | grep SLAB_FREELIST +CONFIG_SLAB_FREELIST_RANDOM=y +CONFIG_SLAB_FREELIST_HARDENED=y -- Kees Cook
