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Date:      Wed, 8 Sep 1999 12:37:54 +0300 (EEST)
From:      "Decebal Topala" <decebal@mail.md>
To:        "Alfred Perlstein" <bright@wintelcom.net>
Cc:        questions@FreeBSD.ORG
Subject:   Re: don't fork bomb
Message-ID:  <199909080937.MAA07551@atlas.dnt.md>

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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.



> 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.
???
DEcebal 

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