SUMMARY:Segmentation fault about ps

From: Seong-Woon Kim (
Date: Fri Aug 04 1995 - 16:26:46 CDT

Thank you to all that responded.

My original question was :
 when do 'ps' command, why the "segmentation fault" occur?

Thanks to:
 Mike Salehi
 David Gunn
 Martin Murphy
 Ellen Herrera
 Mark Hargrave
 Peter Barneveld
 SungBae Park

From, John O'Connor:
I think that there are two possibilities here:

1) Your copy of the ps command is broken.
        You may think that this sounds unlikely but it does
        happen from time to time. Perhaps something overwrote
        part of the file or the file was wrongly copied during
        a backup restore operation or something.

2) Something is wrong on your system.
       For example, many of the system calls in SunOS do not
       check that the return from malloc is a valid pointer
       and not NULL. Thus, they malloc some memory and try to
       access the address referenced by NULL. This causes the
       segmentation violation. This particular problem may
       may happen if you have run out of swap space.
       You can get this fault as well if the root partition or
       the tmp partition are full. I have seen this on some

>From , Mike (Mehran) Salehi :
the most likely is the vmunix namelist does not match
the running vmunix, a reboot would fix that problem.

From, Irana :
I have found a similar problem in sunsolve:
Patch-ID# 101442-02
Keywords: "j", ps(1), dump, core, segv, fault, segmentation, j, ps
Synopsis: SunOS 4.1.3_U1: ps(1) with "j" option may segmentation fault
(rev -01)
1108978 ps(1) with "j" option may cause a segmentation fault

        Login as root

        cp /usr/kvm/ps /usr/kvm/ps.FCS
        mv `arch -k`/ps /usr/kvm/ps
        chown root.kmem /usr/kvm/ps
        chmod 755 /usr/kvm/ps
        chmod g+s /usr/kvm/ps

Problem Description:
1108978 ps(1) with "j" option may cause a segmentation fault

        Login as root

        cp /usr/kvm/ps /usr/kvm/ps.FCS
        mv `arch -k`/{4.1.2,4.1.3}/ps /usr/kvm/ps
        chown root.kmem /usr/kvm/ps
        chmod 755 /usr/kvm/ps
        chmod g+s /usr/kvm/ps

>From Ellen Herrera :
The only time I have ever seen this happen, is when a new kernel
is installed in the root partition, but the machine is not
rebooted. If you have made recent changes to the kernel file,
you may want to reboot to be sure the changes and the new
kernel have taken effect.

  ___/| Seong-Woon Kim ETRI, Processor Section
 < / P.O.Box 106, Yusung
  / \ . 042 860 6621 Taejon, Korea

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