From owner-freebsd-questions  Wed Sep  8  8:24:41 1999
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Date: Wed, 8 Sep 1999 08:42:25 +0000 (GMT)
From: Alfred Perlstein <bright@wintelcom.net>
To: Decebal Topala <decebal@mail.md>
Cc: questions@FreeBSD.ORG
Subject: Re: don't fork bomb
In-Reply-To: <199909080937.MAA07551@atlas.dnt.md>
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On Wed, 8 Sep 1999, Decebal Topala wrote:

> On Tuesday, September 07, 1999 at 04:14:23 PM, Alfred Perlstein wrote:
> 
> > 
> > On Tue, 7 Sep 1999, Decebal Topala wrote:
> > 
> > > Hi 
> > > 
> > > I used an script to ping all ip addresses in my ocal ip subnet.
> > > I was very slow. In order to make this faster i put ping process in 
> > > baground. After 15 second system is dumpimg.
> > 
> > can you please tell us the panic message?
> > 
> Here is the trap message 
> 
> 
> Fatal trap:12 page fault while in kernel mode 
> fault virtual address=0x50008800
> fault mode= supervisor read,page not present
> instruction pinter 0x8:0xc0177b58
> stack pionter	0x10:0xcb074e18
> frame pointer 	0x10:0xcad77e1c
> code segment:	base 0x0, limit 0xffff, type 0x1b
> 		DPL 0, press 1, def32 1, gran 1,
> processor eflags intrerupt enable, resume,IOPL=0;
> current process	2690sh  (Current proccess sometimes was idle) 
> intrerupt mask: net;
> trap number:12 
> panic:fault page
> 
> This works even if it is runned from simple user id.

Is it possible for you to get a crash dump and give a traceback?

> > in the meantime, try adding:
> > 
> > options  NMBCLUSTERS=8192
> Even wwith this it crashes. 
> 
> I thing it is an network issue.
> To many icmp opened sessions at the same time.
> 
> > 
> > I'll see what I can do about this on a -stable box i have.
> > 
> > it looks like this script constitutes a nice fork bomb, you
> > are forking 62230 processes, maybe a workaround would be to
> > add a "wait" right after before "class_b=$((${class_b}+1))"
> 
> > this will limit the script to 254 pings at a time...
> I agree. 
> 
> > 
> > good luck,
> > -Alfred
> >
> 
> Yes but some users will be able to down my bsd box.

Not if you give them login limits, "man login.conf" should help.

> ???
> DEcebal 
> 
> ___________________________________________
> Get your free mail box @ http://www.mail.md
> 
> 



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