Merge tag 'vfs-6.13.pidfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Merge tag 'vfs-6.13.pidfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull pidfs update from Christian Brauner:
 "This adds a new ioctl to retrieve information about a pidfd.

  A common pattern when using pidfds is having to get information about
  the process, which currently requires /proc being mounted, resolving
  the fd to a pid, and then do manual string parsing of /proc/N/status
  and friends. This needs to be reimplemented over and over in all
  userspace projects (e.g.: it has been reimplemented in systemd, dbus,
  dbus-daemon, polkit so far), and requires additional care in checking
  that the fd is still valid after having parsed the data, to avoid
  races.

  Having a programmatic API that can be used directly removes all these
  requirements, including having /proc mounted.

  As discussed at LPC24, add an ioctl with an extensible struct so that
  more parameters can be added later if needed. Start with returning
  pid/tgid/ppid and some creds unconditionally, and cgroupid optionally"

* tag 'vfs-6.13.pidfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  pidfd: add ioctl to retrieve pid info