Re: Hidden PIDs in /proc

From: Miquel van Smoorenburg
Date: Tue Mar 23 2004 - 11:22:31 EST


In article <200403231708.15812.AlberT@xxxxxxxxxxxxxxxx>,
Emiliano 'AlberT' Gabrielli <AlberT@xxxxxxxxxxxxxxxx> wrote:
>
>Hi all,
>
> I discovered some "hidden" pid dirs in /proc :
>
>root@emc2:# ls -lha /proc/ | grep 4673
>root@emc2:# ls -lha /proc/4673/
>totale 0
>dr-xr-xr-x 3 albert albert 0 2004-03-23 17:02 .
>dr-xr-xr-x 108 root root 0 2004-03-23 16:10 ..

It's just a thread. For a threaded process, only the thread group
leader is listed in /proc directly. The other threads are visible
under /proc/<tgid>/task (try it).

>After 2 days of headhake searching for possible rootkits, reinstalling all the
>basic system, libs and so on (from a clean live-CD boot) ...
>I noticed that these process seem all to use pthreads ... so, the question is:
>
>is my problem related/solved by the initramfs-search-for-init-zombie-fix.patch
>in the -mm1 tree ??

No, by upgrading to a more recent procps.

# ps ax | grep mozilla
16252 ? S 10:21 /usr/lib/mozilla-firefox/firefox-bin
$ ps ax -T | grep moz
16252 16252 ? S 10:21 /usr/lib/mozilla-firefox/firefox-bin
16252 16264 ? S 0:01 /usr/lib/mozilla-firefox/firefox-bin
16252 16266 ? S 0:03 /usr/lib/mozilla-firefox/firefox-bin
16252 21530 ? S 0:00 /usr/lib/mozilla-firefox/firefox-bin

Also note:

# ls /proc/16252/task
16252/ 16264/ 16266/ 21530/

Mike.
--
Netu, v qba'g yvxr gur cynvagrkg :)

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/