Re: Oops on 2.4.x invalid procfs i_ino value

From: Brent Casavant
Date: Mon Dec 20 2004 - 17:38:52 EST

On Fri, 17 Dec 2004, William Lee Irwin III wrote:

> On Fri, Dec 17, 2004 at 04:49:44PM -0600, Brent Casavant wrote:
> >> On a related note, if it matters, on about half the crash dumps I've
> >> looked at, I see a pid of 0 has been assigned to a user process,
> >> tripping this same problem. I suspect there's another bug somewhere
> >> that's allowing a pid of 0 to be chosen in the first place -- but I
> >> don't totally discount that this problem may lay in SGI's patches to
> >> this particular kernel -- I'll need to take a more thorough look.
> On Fri, Dec 17, 2004 at 04:38:35PM -0800, William Lee Irwin III wrote:
> > That's rather ominous. I'll pore over pid.c and see what's going on.
> > Also, does the pid.c in your kernel version match 2.6.x-CURRENT?
> Ouch, 2.4.21; this will be trouble. So next, what patches atop 2.4.21?

I wouldn't worry about the pid=0 issue -- I think it's most likely
due to the PAGG patches ( causing
some sort of problem at process teardown (all the pid=0 processes are
in the process of exiting).

I'm more concerned about the (0 == pid & 0xffff) bug, which is present
in the unpatched mainline 2.4.x kernel. It seems that the easiest fix
is marking such pids as in-use at pidmap allocation, so that they are
never assigned to real tasks. I've got the code almost done, but need
to port it to top-of-tree before submitting a patch.


Brent Casavant If you had nothing to fear,
bcasavan@xxxxxxx how then could you be brave?
Silicon Graphics, Inc. -- Queen Dama, Source Wars
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