Hello,

</snip>
> > -	while (frame != NULL && lastframe < frame && INKERNEL(frame)) {
> > +	while (frame != NULL && frame >= topframe &&
> > +	    frame <= (struct callframe *)pcb->pcb_kstack) {
> 
> Why not keep the "lastframe < frame" condition and just replace the
> INKERNEL(frame) check with the "frame <= (struct callframe *)pcb->pcb_kstack"
> check?  That is stricter since it enforces the stack order.
> 

    yes, this makes sense.

The diff below comes with fix traversal of kernel stack
frames. The part which deals with traversal of userland
frames deserves its own diff.

thanks and
regards
sashan

--------8<---------------8<---------------8<------------------8<--------
diff --git a/sys/arch/amd64/amd64/db_trace.c b/sys/arch/amd64/amd64/db_trace.c
index 624d7ed1a73..79b3499dca1 100644
--- a/sys/arch/amd64/amd64/db_trace.c
+++ b/sys/arch/amd64/amd64/db_trace.c
@@ -306,7 +306,8 @@ stacktrace_save_utrace(struct stacktrace *st)
 	/*
 	 * skip kernel frames
 	 */
-	while (frame != NULL && lastframe < frame && INKERNEL(frame)) {
+	while (frame != NULL && lastframe < frame &&
+	    frame <= (struct callframe *)pcb->pcb_kstack) {
 		lastframe = frame;
 		frame = frame->f_frame;
 	}
diff --git a/sys/arch/i386/i386/db_trace.c b/sys/arch/i386/i386/db_trace.c
index b7c8b68711a..677b0680846 100644
--- a/sys/arch/i386/i386/db_trace.c
+++ b/sys/arch/i386/i386/db_trace.c
@@ -305,7 +305,8 @@ stacktrace_save_utrace(struct stacktrace *st)
 	/*
 	 * skip kernel frames
 	 */
-	while (frame != NULL && lastframe < frame && INKERNEL(frame)) {
+	while (frame != NULL && lastframe < frame &&
+	    frame <= (struct callframe *)pcb->pcb_kstack) {
 		lastframe = frame;
 		frame = frame->f_frame;
 	}