svn commit: r336554 - head/sys/dev/vt/hw/ofwfb

[Justin Hibbits]

Author: jhibbits
Date: Fri Jul 20 16:08:14 2018
New Revision: 336554
URL: https://svnweb.freebsd.org/changeset/base/336554

Log:
  vt/ofwfb: Check that /chosen/stdout is valid before using it in initialization
  
  The FDT implementation of OF_instance_to_package() backend checks the
  cross-reference to get the node.  On failure, this returns the input handle
  unchanged.  In the case of ofwfb attachment, if /chosen/stdout property does not
  exist, sc->sc_handle is either garbage or 0, which then gets propagated to node.
  This will prevent "screen" from being used, resulting in not properly attaching.
  Correct this by matching the code in ofwfb_probe().

Modified:
  head/sys/dev/vt/hw/ofwfb/ofwfb.c

Modified: head/sys/dev/vt/hw/ofwfb/ofwfb.c
==============================================================================
--- head/sys/dev/vt/hw/ofwfb/ofwfb.c	Fri Jul 20 16:06:44 2018	(r336553)
+++ head/sys/dev/vt/hw/ofwfb/ofwfb.c	Fri Jul 20 16:08:14 2018	(r336554)
@@ -370,9 +370,11 @@ ofwfb_init(struct vt_device *vd)
 	/* Initialize softc */
 	vd->vd_softc = sc = &ofwfb_conssoftc;
 
+	node = -1;
 	chosen = OF_finddevice("/chosen");
-	OF_getprop(chosen, "stdout", &sc->sc_handle, sizeof(ihandle_t));
-	node = OF_instance_to_package(sc->sc_handle);
+	if (OF_getprop(chosen, "stdout", &sc->sc_handle,
+	    sizeof(ihandle_t)) == sizeof(ihandle_t))
+		node = OF_instance_to_package(sc->sc_handle);
 	if (node == -1) {
 		/*
 		 * The "/chosen/stdout" does not exist try