Disabling CPU vulnerabilities workarounds
From: Artem S. Tashkinov
Date: Thu Aug 23 2018 - 12:33:51 EST
As time goes by more and more fixes of Intel/AMD/ARM CPUs
vulnerabilities are added to the Linux kernel without a simple way to
disable them all in one fell swoop.
Disabling is a good option for strictly confined environments where no
3d party untrusted code is ever to be run, e.g. a rendering farm, a
supercomputer, or even a home server which runs Samba/SSH server and
I wonder if someone could wrote a patch which implemented the following
two options for the kernel:
* A boot option option which allows to disable most runtime
protections/workarounds/fixes (as far as I understand some of them can't
be reverted since they are compiled in or use certain GCC flags), e.g.
let's call it "insecure" or "insecurecpumode".
* A compile-time CONFIG_ option which disables all these fixes
_permanently_ without a way to turn them later back on during runtime.
Right now linux/Documentation/admin-guide/kernel-parameters.txt is a
mess of various things which take ages to sift through and there's zero
understanding whether you've found everything and correctly disabled it.