HEADSUP: cygserver now has MSG, SEM and SHM support

Corinna Vinschen vinschen@redhat.com
Mon Dec 1 09:29:00 GMT 2003

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 Vinschen                  Please, send mails regarding Cygwin to
Cygwin Developer                                mailto:cygwin@cygwin.com
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