a sysctl for process binary osreldate

[Mikolaj Golub]

Hi,

Currently we can check and change binary osreldate of another process via
procfs(5).

Kostik suggested to add a new sysctl for the same purpose and also extend
procstat to show osrel.

Here are patches I am going to commit if there are no objections or
suggestions.

http://people.freebsd.org/~trociny/kern_proc_osrel.1.patch
http://people.freebsd.org/~trociny/procstat.osrel.1.patch

I set the same permissions as for procfs(5) osrel -- so only user can read it,
but may be this is too restrictive and p_cansee on read would be ok?

I added osrel output to procstat -b option:

kopusha:~% procstat -b 2975
  PID COMM                OSREL PATH
 2975 emacs             1000001 /usr/local/bin/emacs-23.3

Would this be ok or someone see a better way?

-- 
Mikolaj Golub