From afca197f5240ce2c2c7abfe5c9fbc50ba55f178b Mon Sep 17 00:00:00 2001 From: Mitchell Horne Date: Mon, 13 Feb 2023 13:44:03 -0400 Subject: [PATCH] ofwbus: only allow unit number zero ofwbus has always been the root of attachment for OFW/FDT platforms. It may have simplebus children, but we expect only one instance of the ofwbus driver, added directly by nexus. We may as well ensure this remains the case. Reviewed by: jhb MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D38493 --- sys/dev/ofw/ofwbus.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/sys/dev/ofw/ofwbus.c b/sys/dev/ofw/ofwbus.c index cc8c66170cd..80d013cd06e 100644 --- a/sys/dev/ofw/ofwbus.c +++ b/sys/dev/ofw/ofwbus.c @@ -89,6 +89,11 @@ ofwbus_probe(device_t dev) if (OF_peer(0) == 0) return (ENXIO); + /* Only one instance of ofwbus. */ + if (device_get_unit(dev) != 0) + panic("ofwbus added with non-zero unit number: %d\n", + device_get_unit(dev)); + device_set_desc(dev, "Open Firmware Device Tree"); return (BUS_PROBE_NOWILDCARD); }