Wireshark · Wireshark-dev: Re: [Wireshark-dev] Use of MAP_ANON in epan/emem.c

[Guy Harris <guy@xxxxxxxxxxxx>]

On Jun 16, 2006, at 6:11 PM, Guy Harris wrote:

> The IRIX 6.5 man page for /dev/zero indicates you can mmap it to get
> anonymous pages.  Are there any UN*Xes we support that *don't* allow
> you to mmap /dev/zero to get anonymous pages?

Yes - it appears that FreeBSD and OS X don't.

> if so, we might want to use MAP_ANONYMOUS on systems that
> define it, otherwise use MAP_ANON on systems that define it (OS X
> 10.4 defines MAP_ANON but *NOT* MAP_ANONYMOUS, and that seems to be a
> general BSD characteristic - I don't find any definitions of
> MAP_ANONYMOUS in the sys/sys source directory of fairly recent
> {Free,Net,Open}BSD), otherwise use "/dev/zero".

I've checked in a change to do that.  It allows Wireshark to build on  
OS X (the change of MAP_ANON to MAP_ANONYMOUS probably broke  
{Free,Open,Net,DragonFly}BSD builds as well), and it includes  
untested code to handle systems that have neither MAP_ANONYMOUS nor  
MAP_ANON - it assumes they have /dev/zero, opens that, and maps it.