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Date: Wed, 12 Feb 1997 20:42:25 +1100 (EST)
From: "Daniel O'Callaghan" <danny@panda.hilink.com.au>
To: Joerg Wunsch <joerg_wunsch@uriah.heep.sax.de>
cc: hackers@freebsd.org
Subject: Re: strlen() question
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On Wed, 12 Feb 1997, J Wunsch wrote:

> As Daniel O'Callaghan wrote:
> 
> > Below is the code for strlen() from libc.  It is extremely simple, and
> > fast. Is it really safe to assume that strlen() will never exceed process
> > memory bounds before striking a '\0'?  Or should there be a strnlen()
> > function in libc for checking the length of suspicious strings? 
> 
> Why?  The worst that would happen by touching off the end of your
> address space is a SIGSEGV.  The problem with str*cpy() touching
> beyond the bounds of their arrays is that they can _modify_ the stack
> then, but that can't happen with strlen() since it doesn't modify
> anything.

I was thinking of bounds checking w/o a copy.

Danny