Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.Approved by: re (implicit)Sponsored by: The FreeBSD Foundation
Don't copy and return a potentially unset buffer when jail_get fails.
Add libjail, a (somewhat) simpler interface to the jail_set and jail_getsystem calls and the security.jail.param sysctls.Approved by: bz (mentor)