Subject: kern/35830: procfs "exe" symlinks do not work with nullfs
To: None <kern-bug-people@netbsd.org, gnats-admin@netbsd.org,>
From: None <apb@cequrux.com>
List: netbsd-bugs
Date: 02/24/2007 19:00:00
>Number: 35830
>Category: kern
>Synopsis: procfs "exe" symlinks do not work with nullfs
>Confidential: no
>Severity: non-critical
>Priority: medium
>Responsible: kern-bug-people
>State: open
>Class: sw-bug
>Submitter-Id: net
>Arrival-Date: Sat Feb 24 19:00:00 +0000 2007
>Originator: Alan Barrett
>Release: NetBSD 4.99.12
>Organization:
Not much
>Environment:
System: NetBSD 4.99.12
Architecture: i386
Machine: i386
>Description:
The "exe" symlinks in the procfs file system do not work properly
for nullfs file systems. Instead of pointing to the executed
program, procfs dymlinks like /proc/curproc/exe point to "/".
The "cwd" symlinks, on the other hand, work correctly with nullfs.
>How-To-Repeat:
$ sudo mount -t null /bin /mnt
$ cd /mnt
$ /bin/ls -l /proc/curproc/cwd /proc/curproc/exe # works
lr-xr-xr-x 1 root wheel 4 Feb 24 20:49 /proc/curproc/cwd -> /mnt
lr-xr-xr-x 1 root wheel 7 Feb 24 20:49 /proc/curproc/exe -> /bin/ls
$ /mnt/ls -l /proc/curproc/cwd /proc/curproc/exe # cwd works, exe fails
lr-xr-xr-x 1 root wheel 4 Feb 24 20:49 /proc/curproc/cwd -> /mnt
lr-xr-xr-x 1 root wheel 1 Feb 24 20:49 /proc/curproc/exe -> /
$ ./ls -l /proc/curproc/cwd /proc/curproc/exe # cwd works, exe fails
lr-xr-xr-x 1 root wheel 4 Feb 24 20:49 /proc/curproc/cwd -> /mnt
lr-xr-xr-x 1 root wheel 1 Feb 24 20:49 /proc/curproc/exe -> /
$ cd /
$ sudo umount /mnt
>Fix:
Unknown