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Re: HEADSUP: cygserver now has MSG, SEM and SHM support
- From: Corinna Vinschen <vinschen at redhat dot com>
- To: cygwin-developers at cygwin dot com
- Date: Mon, 1 Dec 2003 10:29:41 +0100
- Subject: Re: HEADSUP: cygserver now has MSG, SEM and SHM support
- References: <20031126111113.GF21540@cygbert.vinschen.de> <3FC8C76D.7040704@netscape.net> <20031129232030.GA15836@cygbert.vinschen.de> <3FCA436F.4000004@netscape.net>
- Reply-to: cygwin-developers at cygwin dot com
On Sun, Nov 30, 2003 at 02:22:23PM -0500, Nicholas Wourms wrote:
> What I was looking at I noticed that we also #ifdef'd out the member
> pointers msg_{first,last} of the structure msqid_ds. However these are
> defined as public members on both bsd and solaris[1]. Furthermore, a
> number of manpages for list them in the public declaration of the
> structure. However, I am not an expert on SystemV IPC. Much of what I
> do know is from reading "Advanced Unix Programming", which is admittedly
> FreeBSD-centric, so I could be wrong.
SUSv3 doesn't define them and that makes a lot of sense. These pointers
are used for keeping a linked list of messages in kernel space, so the
memory addresses in these pointers don't make any sense to the
application. For a CYgwin application it's basically the same situation,
just substitute "kernel" by "Cygserver". While you're right that these
pointers are often publically available, they are useless and dangerous.
Corinna
--
Corinna Vinschen Please, send mails regarding Cygwin to
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