kern/94269: procfs shows wrong data if executable is running from nullfs

[Anatoli Klassen]

>Number:         94269
>Category:       kern
>Synopsis:       procfs shows wrong data if executable is running from nullfs
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Mar 09 13:00:12 GMT 2006
>Closed-Date:
>Last-Modified:
>Originator:     Anatoli Klassen
>Release:        FreeBSD 6.1-PRERELEASE i386
>Organization:
>Environment:
System: FreeBSD pluto 6.1-PRERELEASE FreeBSD 6.1-PRERELEASE #0: Wed Mar  8 23:08:16 CET 2006     root at pluto:/usr/obj/usr/src/sys/PLUTO  i386


	
>Description:
	I have a nullfs-mounted dir with some executables and a mounted procfs (under /proc).
	Now if one of the executables tries to read /proc/curproc/file it got an error or sometimes wrong path.

>How-To-Repeat:
	# mount -t procfs procfs /proc
	# mount -t nullfs /bin /mnt
	# /bin/ls -l /proc/curproc/file
	lr--r--r--  1 root  wheel  0 Mar  9 13:53 /proc/curproc/file -> /bin/ls
	# /mnt/ls -l /proc/curproc/file
	lr--r--r--  1 root  wheel  0 Mar  9 13:53 /proc/curproc/file -> unknown

	The second ls shows wrong info.

>Fix:

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