contrib: add script to dump platform drivers

For a discussion on the linux-debuggers mailing list:
https://lore.kernel.org/linux-debuggers/87v8fiw0fm.fsf@oracle.com/T/#t

Signed-off-by: Omar Sandoval <osandov@osandov.com>

contrib/platform_drivers.py

@@ -0,0 +1,28 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+"""Print registered platform drivers."""
+
+from drgn import NULL, container_of
+from drgn.helpers.linux.list import list_for_each_entry
+
+
+def bus_to_subsys(bus):
+    for sp in list_for_each_entry(
+        "struct subsys_private",
+        prog["bus_kset"].list.address_of_(),
+        "subsys.kobj.entry",
+    ):
+        if sp.bus == bus:
+            return sp
+    return NULL(bus.prog_, "struct subsys_private *")
+
+
+sp = bus_to_subsys(prog["platform_bus_type"].address_of_())
+for priv in list_for_each_entry(
+    "struct driver_private", sp.drivers_kset.list.address_of_(), "kobj.entry"
+):
+    driver = priv.driver
+    print(driver.name.string_().decode())
+    platform_driver = container_of(driver, "struct platform_driver", "driver")
+    print(platform_driver)