Write-protect for userfaultfd()

The userfaultfd() system call allows one process to handle page faults for another — in user space. Its original use case was to support transparent container migration, but other uses have developed over the years. At the 2019 Linux Storage, Filesystem, and Memory-Management Summit, Andrea Arcangeli described a scheme to add write-protection support to userfaultfd(). After a year of lost time fighting speculative-execution problems, Arcangeli is about ready to move this feature into the mainline.

Full Story (comments: 6)