1 files changed, 48 insertions, 0 deletions
diff --git a/sys/tools/gdb/acttrace.py b/sys/tools/gdb/acttrace.py
new file mode 100644
index 000000000000..147effbbddf1
--- /dev/null
+++ b/sys/tools/gdb/acttrace.py
@@ -0,0 +1,48 @@
+#
+# Copyright (c) 2022 The FreeBSD Foundation
+#
+# This software was developed by Mark Johnston under sponsorship from the
+# FreeBSD Foundation.
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+
+import gdb
+from freebsd import *
+from pcpu import *
+
+class acttrace(gdb.Command):
+    """
+    Register an acttrace command with gdb.
+
+    When run, acttrace prints the stack trace of all threads that were on-CPU
+    at the time of the panic.
+    """
+    def __init__(self):
+        super(acttrace, self).__init__("acttrace", gdb.COMMAND_USER)
+
+    def invoke(self, arg, from_tty):
+        # Save the current thread so that we can switch back after.
+        curthread = gdb.selected_thread()
+
+        for pcpu in pcpu_foreach():
+            td = pcpu['pc_curthread']
+            tid = td['td_tid']
+
+            gdb_thread = tid_to_gdb_thread(tid)
+            if gdb_thread is None:
+                raise gdb.error(f"failed to find GDB thread with TID {tid}")
+            else:
+                gdb_thread.switch()
+
+                p = td['td_proc']
+                print("Tracing command {} pid {} tid {} (CPU {})".format(
+                      p['p_comm'], p['p_pid'], td['td_tid'], pcpu['pc_cpuid']))
+                gdb.execute("bt")
+                print()
+
+        curthread.switch()
+
+
+# Registers the command with gdb, doesn't do anything.
+acttrace()