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

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Developer                                mailto:cygwin@cygwin.com
Red Hat, Inc.



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