Re: Problem with netscape 2.0beta1 and ppp-2.1.2d?

Snow Cat (snowcat@gd.cs.csufresno.edu)
Fri, 20 Oct 1995 23:45:23 -0700 (PDT)


Bob Doolittle - Sun Parallel Open Systems once wrote:
>
> Evidently not quite this problem:
>
> From hpa@terminus.storm.net Tue Oct 17 13:20 EDT 1995
> From: hpa@terminus.storm.net (H. Peter Anvin)
> Subject: Re: Problem with netscape 2.0beta1 and ppp-2.1.2d?
> To: rad@via.East.Sun.COM (Bob Doolittle - Sun Parallel Open Systems)
> Cc: linux-gcc@vger.rutgers.edu
>
> It has not been discussed here system failures due to Netscape,
> only Netscape not being able to solve DNS names, which is
> solved by the latest beta version of libc-a.out (4.7.5).
>
> The arguments that a bad libc can cause a system hang seem misguided,
> to me. I don't know a lot about X86 memory protection, but libc code
> should *not* (hopefully cannot) touch hardware directly. I am highly
> doubtful that Linux libc code is an exception. Linux is not MSDOS
> :-). Unix, like any real OS, has the responsibility of managing
> hardware on the app's behalf, so that broken apps *can't* bring systems
> down, and to multiplex accesses from multiple apps. That's what OS's
> are *for*. Xinit is the only app I am aware of (on the vast majority
> of systems) that touches hardware directly, and as such can bring down
> a system if it is buggy. libc is user-space code; consider it part of
> the running app for all intents and purposes. So, again, I don't see
> how Netscape can be the culprit here, even Netscape linked with the
> world's most broken libc. It just shouldn't be possible. If an app
> can wedge the system, it's exercising a bug in Linux (potentially
> kernel PPP code) or X (perhaps issuing an invalid command sequence to
> the graphics hardware which is hanging the bus?), or you have
> broken/buggy hardware.
>

I sure saw Open Windows lock up a Sun many times :)

The problem is that if X is sitting in infinite loop and is not responding
to any keystrokes or signals, you can't even switch to another VC to kill it.
Or for this matter check if the rest of your system is still alive - unless you
happen to have a serial terminal or network to login from and kill X.

-- 
     Snow ^oo^ Cat <snowcat@gd.cs.CSUFresno.EDU>
      _  ->  <-    aka Oleg Kibirev <oleg@gd.cs.CSUFresno.EDU>
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