Solved 4.2BSD panic trap 9 problem on VAX 11/785

[Chris Torek]

>>>No!  The fix is to insert a ".space n" directive immediately before
>>>the function in locore.s that is causing the problem.
 
>> Yes, this is better, but is also more difficult to apply.  It's
>				    ^^^^^^^^^^^^^^^^^^^^^^^?

>There is nothing difficult about this.  References to probes in C code
>are another problem; you probably WILL need to pad with nop's.  So what?
>Nothing says you have to use the same solution in both languages.

That is what I meant.  I considered different phrasing, but thought
that was the shortest that conveyed what I meant.  I guess it did,
but just barely.  So here's the long version:

	Yes, it's better in this case to use a .space directive to
	push the probe down, as that saves CPU time (as you pointed
	out).  However, if you encounter the same problem later
	with one of the probe instructions which is embedded within
	the C code, it will be much more difficult (though not
	impossible) to use .space or other magic to move the probe
	instruction.  Using nop's may be inefficient, but it is
	easy to implement in every case in which a solution to the
	probe bug must be applied, therefore I present it as the
	general solution.

How's that? :-)
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 4251)
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