Index: sys/amd64/amd64/db_trace.c
===================================================================
--- sys/amd64/amd64/db_trace.c
+++ sys/amd64/amd64/db_trace.c
@@ -130,13 +130,6 @@
 DB_DRX_FUNC(dr6)
 DB_DRX_FUNC(dr7)
 
-static __inline long
-get_rsp(struct trapframe *tf)
-{
-	return ((ISPL(tf->tf_cs)) ? tf->tf_rsp :
-	    (db_expr_t)tf + offsetof(struct trapframe, tf_rsp));
-}
-
 static int
 db_frame(struct db_variable *vp, db_expr_t *valuep, int op)
 {
@@ -161,7 +154,7 @@
 		return (0);
 
 	if (op == DB_VAR_GET)
-		*valuep = get_rsp(kdb_frame);
+		*valuep = kdb_frame->tf_rsp;
 	else if (ISPL(kdb_frame->tf_cs))
 		kdb_frame->tf_rsp = *valuep;
 	return (1);
@@ -304,7 +297,7 @@
 	tf = (struct trapframe *)((long)*fp + 16);
 
 	if (INKERNEL((long) tf)) {
-		rsp = get_rsp(tf);
+		rsp = tf->tf_rsp;
 		rip = tf->tf_rip;
 		rbp = tf->tf_rbp;
 		switch (frame_type) {
@@ -380,20 +373,20 @@
 				instr = db_get_value(pc, 4, FALSE);
 				if ((instr & 0xffffffff) == 0xe5894855) {
 					/* pushq %rbp; movq %rsp, %rbp */
-					actframe = (void *)(get_rsp(tf) - 8);
+					actframe = (void *)(tf->tf_rsp - 8);
 				} else if ((instr & 0xffffff) == 0xe58948) {
 					/* movq %rsp, %rbp */
-					actframe = (void *)get_rsp(tf);
+					actframe = (void *)tf->tf_rsp;
 					if (tf->tf_rbp == 0) {
 						/* Fake frame better. */
 						frame = actframe;
 					}
 				} else if ((instr & 0xff) == 0xc3) {
 					/* ret */
-					actframe = (void *)(get_rsp(tf) - 8);
+					actframe = (void *)(tf->tf_rsp - 8);
 				} else if (offset == 0) {
 					/* Probably an assembler symbol. */
-					actframe = (void *)(get_rsp(tf) - 8);
+					actframe = (void *)(tf->tf_rsp - 8);
 				}
 			} else if (strcmp(name, "fork_trampoline") == 0) {
 				/*
@@ -448,9 +441,11 @@
 db_trace_thread(struct thread *thr, int count)
 {
 	struct pcb *ctx;
+	struct trapframe *tf;
 
 	ctx = kdb_thr_ctx(thr);
-	return (db_backtrace(thr, NULL, (struct amd64_frame *)ctx->pcb_rbp,
+	tf = thr == kdb_thread ? kdb_frame : NULL;
+	return (db_backtrace(thr, tf, (struct amd64_frame *)ctx->pcb_rbp,
 	    ctx->pcb_rip, ctx->pcb_rsp, count));
 }
 
Index: sys/i386/i386/db_trace.c
===================================================================
--- sys/i386/i386/db_trace.c
+++ sys/i386/i386/db_trace.c
@@ -541,9 +541,11 @@
 db_trace_thread(struct thread *thr, int count)
 {
 	struct pcb *ctx;
+	struct trapframe *tf;
 
 	ctx = kdb_thr_ctx(thr);
-	return (db_backtrace(thr, NULL, (struct i386_frame *)ctx->pcb_ebp,
+	tf = thr == kdb_thread ? kdb_frame : NULL;
+	return (db_backtrace(thr, tf, (struct i386_frame *)ctx->pcb_ebp,
 	    ctx->pcb_eip, ctx->pcb_esp, count));
 }