The STACKLEAK kernel security feature has been in the works for quite some
time now, but has not, as yet, made its way into the mainline. That is not
for lack of trying, as Alexander Popov has posted 15 separate versions of
the patch set since May 2017. He described STACKLEAK and its tortuous path
toward the mainline in a talk
[YouTube video] at the 2018
Linux Security Summit.