Made use of MNT_USER flag and inform about user responsible for mount

in those cases:
1. File system was mounted by an unprivileged user.
2. File system was mounted by an unprivileged root user.
3. File system was mounted by a privileged non-root user.

Point 1 is when file system was mounted by unprivileged user
(sysctl vfs.usermount was equal to 1 then).

Point 2 is when file system was mounted by root, while sysctl
security.bsd.suser_enabled is set to 0 and sysctl vfs.usermount
is set to 1.

Point 3 is because we want to be ready for capabilities.

Reviewed by:	rwatson
Approved by:	scottl (mentor)

1 files changed, 5 insertions, 1 deletions

diff --git a/sbin/mount/mount.c b/sbin/mount/mount.c
index e968786..f944671 100644
--- a/sbin/mount/mount.c
+++ b/sbin/mount/mount.c
@@ -524,7 +524,11 @@ prmount(sfp)
 			(void)printf(", %s", o->o_name);
 			flags &= ~o->o_opt;
 		}
-	if (sfp->f_owner) {
+	/*
+	 * Inform when file system is mounted by an unprivileged user
+	 * or privileged non-root user.
+	 */
+	if ((flags & MNT_USER) != 0 || sfp->owner != 0) {
 		(void)printf(", mounted by ");
 		if ((pw = getpwuid(sfp->f_owner)) != NULL)
 			(void)printf("%s", pw->pw_name);