Re: do_execve() finding vmspace_destroyed set under load

From: Kris Kennaway (kris_at_obsecurity.org)
Date: 01/30/05

  • Next message: Poul-Henning Kamp: "tcp_isn_tick() / dummynet() callout madness ?" 
    Date: Sun, 30 Jan 2005 02:57:33 -0800
To: "David G. Lawrence" <dg@dglawrence.com>

    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

  • Next message: Poul-Henning Kamp: "tcp_isn_tick() / dummynet() callout madness ?"

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