Re: do_execve() finding vmspace_destroyed set under load

From: Kris Kennaway <kris_at_obsecurity.org>
Date: Sun, 30 Jan 2005 02:57:33 -0800
On Sun, Jan 30, 2005 at 02:14:03AM -0800, David G. Lawrence wrote:
> > > > Needless to say, the scripts get pretty unhappy when they're summarily
> > > > aborted.  What is the cause of this?
> > > 
> > >    There are many reasons why an exec can fail - you'd need to collect
> > > more info to be able to say specifically. Speaking generally, the above
> > > code happens because something failed after the process's address space
> > > had been cleared, so there is no process executable image to return
> > > to. The only thing to do in that case is to kill off the process. If
> > > you're only seeing the problem under load, it is probably indicating
> > > that your running out of a kernel VM pool of some kind.
> > 
> > Any suggestions on what to look at to try and debug this further?
> 
>    The first thing to do is to add some kernel printf's to do_execve()
> in each of the 'if (error)' cases to determine where the error is occuring.
> It's probably not worth putting them in cases prior to the 'loop through
> the list of image activators', since the vmspace isn't destroyed until
> then.
>    Once you've done that, the cause of the problem should become obvious.

Thanks.

Kris

Received on Sun Jan 30 2005 - 09:57:34 UTC

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