C bug causes double fault

[Wm. E. Davidsen Jr]

In article <9900 at smoke.BRL.MIL> gwyn at brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>) writes:
| Of course nobody would call it "reasonable", but it's not too surprising.
| Incorrect user-mode code on a nonprotected multitasking system (forced by
| limitations of the PC/AT architecture) can easily crash the entire system.

  I'm sure dozens of people will tell you that the 286 has full memory
and i/o space control in protected mode, and that all UNIX versions on
the 286 use this. The flaw is in the handling of floating point
exceptions.

  Question: I could see this failing if you used a "%f" format to print
an int, since it would be an unnormalized float, but why was printf
doing anything in f.p. on this??

  To the person who maligned the 286 vs. the PDP-11. 16MB segmented
beats 256k linear every time. Ask anyone who ever tried to shoehorn an
application one an old 11. Some of the very top of the line 11's had
access to more memory, I believe, but I don't think it was more
convenient than the "huge" model, in that you still only have 16 bit
int's for subscripts. The last 11 I used was a 40 (or 45) and V7.
-- 
	bill davidsen		(wedu at crd.GE.COM)
  {uunet | philabs}!steinmetz!crdos1!davidsen
"Stupidity, like virtue, is its own reward" -me