kern/121522: add closefrom() system call

[Ighighi]

>Number:         121522
>Category:       kern
>Synopsis:       add closefrom() system call
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Sun Mar 09 14:40:00 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator:     Ighighi
>Release:        6.3-STABLE
>Organization:
>Environment:
FreeBSD orion 6.3-STABLE FreeBSD 6.3-STABLE #0: Mon Mar  3 04:45:31 VET 2008     root at orion:/usr/obj/usr/src/sys/CUSTOM  i386

>Description:
Given that NetBSD, OpenBSD and DragonFly (as well as Solaris and maybe
others) support it, it'd be nice and worthwhile to implement it too on FreeBSD.

I posted a shar on freebsd-hackers "add closefrom() call revisited" available at
http://lists.freebsd.org/pipermail/freebsd-hackers/2007-September/021735.html

It contains 4 possible implementations and comments that, I expect, addresses
the points raised in the first posting at:
http://lists.freebsd.org/pipermail/freebsd-hackers/2007-July/021132.html
>How-To-Repeat:

>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: