=== Shared page address randomization

Links: +
link:https://reviews.freebsd.org/D35392[D35392] link:https://reviews.freebsd.org/D35393[D35393]
link:https://reviews.freebsd.org/D35349[D35349]

Contact: Kornel Duleba <mindal@semihalf.com> +
Contact: Marcin Wojtas <mw@FreeBSD.org>

The shared page is an R/X page that is mapped into each process by the image activator.
It stores the signal trampoline, as well as other metadata e.g. information needed to implement user space timecounters.
Previously it was mapped at the top of the process virtual address space.
With the described changes its address will be randomized.
We plan to turn the feature on by default for 64bit binaries, across all architectures.
Currently the patches are under review and await approval.

Sponsor: Stormshield
