diff --git a/dev/gdb/fd.gdb b/dev/gdb/fd.gdb
new file mode 100644
index 000000000..736dddfa1
--- /dev/null
+++ b/dev/gdb/fd.gdb
@@ -0,0 +1,39 @@
+# list info about open FD
+define fd_dump
+  set $f = 0
+  while $f < $g.maxsock
+    if fdtab[$f].owner != 0
+      printf "fd %5d: rm=%#lx tm=%#lx um=%#lx cb=%p ownr=%p st=%#x refc=%#x tkov=%u gen=%u\n", $f, fdtab[$f].running_mask, fdtab[$f].thread_mask, fdtab[$f].update_mask, fdtab[$f].iocb, fdtab[$f].owner, fdtab[$f].state, fdtab[$f].refc_tgid, fdtab[$f].nb_takeover, fdtab[$f].generation
+    end
+    set $f = $f + 1
+  end
+end
+
+# only those attached to a listener
+define fd_dump_listener
+  set $f = 0
+  while $f < $g.maxsock
+    if fdtab[$f].owner != 0 && fdtab[$f].iocb == &sock_accept_iocb
+      set $c = (struct listener *)fdtab[$f].owner
+      printf "fd %5d: rm=%#lx tm=%#lx um=%#lx st=%#x refc=%#x tkov=%u gen=%u listener=%p(%s): flg=%#x state=%d fe=%p(%s) acc=%p\n", $f, fdtab[$f].running_mask, fdtab[$f].thread_mask, fdtab[$f].update_mask, fdtab[$f].state, fdtab[$f].refc_tgid, fdtab[$f].nb_takeover, fdtab[$f].generation, fdtab[$f].owner, $c->name, $c->flags, $c->state, $c->bind_conf.frontend, $c->bind_conf.frontend.id, $c->bind_conf.accept
+    end
+    set $f = $f + 1
+  end
+end
+
+# only those attached to a connection
+define fd_dump_conn
+  set $f = 0
+  while $f < $g.maxsock
+    if fdtab[$f].owner != 0 && fdtab[$f].iocb == &sock_conn_iocb
+      set $c = (struct connection *)fdtab[$f].owner
+      printf "fd %5d: rm=%#lx tm=%#lx um=%#lx st=%#x refc=%#x tkov=%u gen=%u conn=%p: flg=%#x err=%#x ctrl=%p xprt=%p mux=%p", $f, fdtab[$f].running_mask, fdtab[$f].thread_mask, fdtab[$f].update_mask, fdtab[$f].state, fdtab[$f].refc_tgid, fdtab[$f].nb_takeover, fdtab[$f].generation, fdtab[$f].owner, $c->flags, $c->err_code, $c->ctrl, $c->xprt, $c->mux
+      if *$c->target == OBJ_TYPE_LISTENER
+        set $s = (struct session *)$c->owner
+        printf " sess=%p: fe=%p id=%s age=%dms", $s, $s->fe, $s->fe->id, (*global_now_ns - $s->accept_ts) / 1000000
+      end
+      printf "\n"
+    end
+    set $f = $f + 1
+  end
+end