[$] A kernel integrity subsystem update

At the 2018 Linux Storage, Filesystem, and Memory-Management Summit, MimiZohar gave a presentation in thefilesystem track on the Linux integrity subsystem. There is a lotof talk that the integrity subsystem (usually referred to as "IMA", whichis the integritymeasurement architecture, though there is more to the subsystem) iscomplex and not documented well, she said. So she wanted to give an overview of the subsystem and then todiscuss some filesystem-related concerns.