- Add a mitigation for the attack vector of interrupting the saferet
sequence used in the SRSO mitigation and still poisoning the RSB.
Do that by emulating the saferet sequence and thus avoiding executing
a RET instruction.
* tag 'x86_bugs_saferet' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/bugs: Make Safe-RET robust against interrupt injection