Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site ki4pv.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxt!houxm!mtuxo!mtunh!mtung!mtunf!ariel!vax135!petsd!peora!ucf-cs!ki4pv!tanner From: tanner@ki4pv.UUCP (Tanner Andrews) Newsgroups: net.unix-wizards Subject: Xenix Syscrash on Syscall Trace Message-ID: <386@ki4pv.UUCP> Date: Sat, 27-Jul-85 11:38:06 EDT Article-I.D.: ki4pv.386 Posted: Sat Jul 27 11:38:06 1985 Date-Received: Thu, 1-Aug-85 21:41:15 EDT Organization: CompuData South, DeLand Lines: 30 Keywords: xenix, trace_syscall > ... tracing syscall causes syscrash ... Experience here shows that the problem is particularly bad on 8086-based systems. The poor little 8086 can't protect itself. In order to make a multi-user 8086 system, other hardware is required to protect the CPU. Syscall mechanism is to stash a funny address in a funny addr and call indirectly to that. Play around in that funny address setting breakpoints to trace things, mash reset when you're done. With the `286 but version 1 xenix (you want to talk about bugs? let me tell you about bugs...) the hardware was different, but the thing was happy to crash for this sort of thing anyway. Also crashed for full moon, half-moon, wind_out_of_east, and running "vi" as I recall. We now have version 3.0b xenix (no, not 3.1 -- that'll be out a couple of months ago). It does not crash on misguided attempts to trace a syscall. I assume that by now IBM and ALTOS are shipping xenix version 3.xxx -- at least for `286 systems. If this is not the case, would somebody warn me before the boss lays the money down to buy a couple of these things? Of course most of the words used above are trademarks of someone. And of course, none of the opinions { any version of xenix (most esp vers 3.xxx) might possibly have more bugs than a NYC slum or that any chips are not good for anything but controlling elevators } belong to anyone but myself. -- Tanner Andrews, KI4PV uucp: ...!decvax!ucf-cs!ki4pv!tanner