Subject: Re: gdb over ktrace
To: None <>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
List: tech-kern
Date: 04/13/2000 17:20:27
>>         int *p;
>>         p = 0;
>>         *p = 100;
> ??? Aren't you supposed to malloc space, rather than just arbitrarily
> start accessing it?  You're stepping on whatever is in page 0...

Do we have any ports that have anything mapped at address zero?  I
didn't *think* we did...

...and if I might switch to my language-lawyer hat for a moment,
assuming that indirecting through a nil pointer accesses "page 0" is a
rather machine-dependent assumption.  (Do we have any port which either
doesn't have a "page 0" or uses a nil-pointer representation that
doesn't point there?  I suspect not, in which case this is a
theoretical nitpick only.)

Of course, whether or not we have anything at address zero on the port
in question, it's hardly reasonable for a ktraced gdb to lock up when
such an access is attempted by the program being debugged.

					der Mouse

		     7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B