diff --git a/sys/amd64/amd64/db_trace.c b/sys/amd64/amd64/db_trace.c
--- a/sys/amd64/amd64/db_trace.c
+++ b/sys/amd64/amd64/db_trace.c
@@ -142,6 +142,7 @@
 db_nextframe(struct amd64_frame **fp, db_addr_t *ip, struct thread *td)
 {
 	struct trapframe *tf;
+	uintptr_t tf_addr;
 	int frame_type;
 	long rip, rsp, rbp;
 	db_expr_t offset;
@@ -204,29 +205,34 @@
 	 * Point to base of trapframe which is just above the
 	 * current frame.
 	 */
-	tf = (struct trapframe *)((long)*fp + 16);
+	tf_addr = (uintptr_t)*fp + 16;
 
-	if (INKERNEL((long) tf)) {
-		rsp = tf->tf_rsp;
-		rip = tf->tf_rip;
-		rbp = tf->tf_rbp;
-		switch (frame_type) {
-		case TRAP:
-			db_printf("--- trap %#r", tf->tf_trapno);
-			break;
-		case SYSCALL:
-			db_printf("--- syscall");
-			db_decode_syscall(td, tf->tf_rax);
-			break;
-		case INTERRUPT:
-			db_printf("--- interrupt");
-			break;
-		default:
-			panic("The moon has moved again.");
-		}
-		db_printf(", rip = %#lr, rsp = %#lr, rbp = %#lr ---\n", rip,
-		    rsp, rbp);
+	if (!__is_aligned(tf_addr, _Alignof(*tf)) || !INKERNEL(tf_addr)) {
+		db_printf("--- invalid trapframe %p\n", (void *)tf_addr);
+		*ip = 0;
+		*fp = NULL;
+		return;
 	}
+	tf = (struct trapframe *)tf_addr;
+
+	rsp = tf->tf_rsp;
+	rip = tf->tf_rip;
+	rbp = tf->tf_rbp;
+	switch (frame_type) {
+	case TRAP:
+		db_printf("--- trap %#r", tf->tf_trapno);
+		break;
+	case SYSCALL:
+		db_printf("--- syscall");
+		db_decode_syscall(td, tf->tf_rax);
+		break;
+	case INTERRUPT:
+		db_printf("--- interrupt");
+		break;
+	default:
+		__assert_unreachable();
+	}
+	db_printf(", rip = %#lr, rsp = %#lr, rbp = %#lr ---\n", rip, rsp, rbp);
 
 	*ip = (db_addr_t) rip;
 	*fp = (struct amd64_frame *) rbp;
@@ -318,14 +324,18 @@
 		}
 
 		db_nextframe(&frame, &pc, td);
-
-		if (INKERNEL((long)pc) && !INKERNEL((long)frame)) {
-			sym = db_search_symbol(pc, DB_STGY_ANY, &offset);
-			db_symbol_values(sym, &name, NULL);
-			db_print_stack_entry(name, pc, frame);
+		if (frame == NULL)
 			break;
-		}
-		if (!INKERNEL((long) frame)) {
+
+		if (!__is_aligned(frame, _Alignof(*frame)) ||
+		    !INKERNEL((uintptr_t)frame)) {
+			if (INKERNEL(pc)) {
+				sym = db_search_symbol(pc, DB_STGY_ANY,
+				    &offset);
+				db_symbol_values(sym, &name, NULL);
+				db_print_stack_entry(name, pc, frame);
+				break;
+			}
 			break;
 		}
 	}