tree 4c43e23b8188f560c5e5573d054e29b837095b54
parent 985e5d856cbcfc17a6646740f2200eb625c76e89
author Eric W. Biederman <ebiederm@xmission.com> 1449556611 -0600
committer Eric W. Biederman <ebiederm@xmission.com> 1474569146 -0500

devpts: Change the owner of /dev/pts/ptmx to the mounter of /dev/pts

In 99.99% of the cases only root in a user namespace can mount /dev/pts
and in those cases the owner of /dev/pts/ptmx will remain root.root

In the oddball case where someone else has CAP_SYS_ADMIN this code
modifies the /dev/pts mount code to use current_fsuid and current_fsgid
as the values to use when creating the /dev/ptmx inode.  As is done
when any other file is created.

This is a code simplification, and it allows running without a root
user entirely.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>