Subject: Re: Weird munmap(2) semantic
To: Charles Hannum <abuse@spamalicious.com>
From: Chuck Cranor <chuck@research.att.com>
List: tech-kern
Date: 09/27/2002 13:42:27
On Fri, Sep 27, 2002 at 03:39:52PM +0000, Charles Hannum wrote:
> In munmap(2), we do this:
>         /*
>          * interesting system call semantic: make sure entire range is
>          * allocated before allowing an unmap.
>          */
 
> What is the reason for this?  I found a reference claming that spec
> 1170 required this, but I also found specific references that say none
> of Linux, Solaris or AIX implement it this way.

i carried it over from the old VM and put the comment there because
i thought it was a little strange.


> I'm considering removing this check...

sounds like a good idea.   i poked at CVS, and it looks like
it got removed from the old VM also when fvdl did the lite2 
merge.   see lines 460 and 467 of:
http://cvsweb.netbsd.org/bsdweb.cgi/syssrc/sys/vm/Attic/vm_mmap.c?annotate=1.63


chuck