PERFORCE change 54786 for review

[Marcel Moolenaar]

http://perforce.freebsd.org/chv.cgi?CH=54786

Change 54786 by marcel at marcel_nfs on 2004/06/13 05:05:10

	Ok, time to mess it all up again. I've been having a lot of
	problems getting backtraces to work from trapframes so a
	new approach is needed. With this commit td_last_frame is
	officially slamdunked to the realm of the goners. We're
	going to use the PCB as the context for debugging and only
	frob the trapframe for singlestepping.
	
	A quick and dirty prototype has shown that the PCB has a
	lot of advantages, including handling of dumppcb and the
	generation of backtraces outside the debugger. A simple
	call to savectx() creates a PCB from which a backtrace can
	be generated.
	
	This branch is broken until further notice.

Affected files ...

.. //depot/projects/gdb/sys/sys/proc.h#15 edit

Differences ...

==== //depot/projects/gdb/sys/sys/proc.h#15 (text+ko) ====

@@ -141,7 +141,6 @@
  *      p - select lock (sellock)
  *      q - td_contested lock
  *      r - p_peers lock
- *	t - updated at kernel (re)entry. Read-only in all other cases.
  *      x - created at fork, only changes during single threading in exec
  *      z - zombie threads/kse/ksegroup lock
  *
@@ -272,7 +271,6 @@
 	int		td_flags;	/* (j) TDF_* flags. */
 	int		td_inhibitors;	/* (j) Why can not run. */
 	int		td_pflags;	/* (k) Private thread (TDP_*) flags. */
-	struct trapframe *td_last_frame; /* (t) Trapframe of last entry. */
 	struct kse	*td_last_kse;	/* (j) Previous value of td_kse. */
 	struct kse	*td_kse;	/* (j) Current KSE if running. */
 	int		td_dupfd;	/* (k) Ret value from fdopen. XXX */