gps(1)'s use of pseudo-ttys
John Murdie <[email protected]> Thu, 05 May 2005 17:37:59 +0100
| Newsgroups | gmane.comp.ide.gps.user |
|---|---|
| Message-ID | <1115311078.5367.31.camel@pc118> |
Did anything come of the queries made about gps(1)'s use of pseudo-ttys on this list back in December 2004? See the seven articles of the thread "More on /dev/pty and Fedora Core 3" posted by Robert Love and Bobby D. Bryant. gps appears to use the (/dev/ttyz0, /dev/ptyz0) pseudo-tty pair to communicate with gdb. When these are found to be unreadable and unwriteable, as is usual on Linux systems, gps writes the error message "/dev/ptyz0: Permission denied." to gps's gdb window and the message "return -1 from allocate_tty" to standard error. Both users above claim that building gps with 'configure --without-ptys' makes no difference. We use devfs here, as is now usual for Linux. As far as I can see, the problem has not been resolved in (free/academic?) production releases of gps - perhaps in gps 3.*? It seems that use of gps(1) has only just started at my site, though we've had it installed for a while. Perhaps the installation of gap 1.0.1 (with gps 2.0.1) and gap 1.1.0 (with gps 2.1.0) awakened interest here. Our problem is that we don't want to make pseudo-ttys generally readable and writeable; it'd be an invitation for local crackers (generally known as 'students') to spy on and even interfere with other users. Is there some good reason why gps doesn't just fork/exec and front-end gdb? Is there a practical solution which won't compromise security? If I've overlooked anything, my apologies. John A. Murdie Department of Computer Science University of York UK