Be more robust with malformed interrupt config data. Instead of crashing

or going into a near-infinite loop, warn and make potentially-reasonable
assumptions.

Reviewed by:	brooks, nwhitehorn

1 files changed, 17 insertions, 5 deletions

diff --git a/sys/dev/fdt/fdt_common.c b/sys/dev/fdt/fdt_common.c
index 9d6840c..b4aabbd 100644
--- a/sys/dev/fdt/fdt_common.c
+++ b/sys/dev/fdt/fdt_common.c
@@ -483,11 +483,23 @@ fdt_intr_to_rl(device_t dev, phandle_t node, struct resource_list *rl,
 	nintr = OF_getencprop_alloc(node, "interrupts",  sizeof(*intr),
 	    (void **)&intr);
 	if (nintr > 0) {
-		iparent = 0;
-		OF_searchencprop(node, "interrupt-parent", &iparent,
-		    sizeof(iparent));
-		OF_searchencprop(OF_xref_phandle(iparent), "#interrupt-cells",
-		    &icells, sizeof(icells));
+		if (OF_searchencprop(node, "interrupt-parent", &iparent,
+		    sizeof(iparent)) == -1) {
+			device_printf(dev, "No interrupt-parent found, "
+			    "assuming direct parent\n");
+			iparent = OF_parent(node);
+		}
+		if (OF_searchencprop(OF_xref_phandle(iparent), 
+		    "#interrupt-cells", &icells, sizeof(icells)) == -1) {
+			device_printf(dev, "Missing #interrupt-cells property, "
+			    "assuming <1>\n");
+			icells = 1;
+		}
+		if (icells < 1 || icells > nintr) {
+			device_printf(dev, "Invalid #interrupt-cells property "
+			    "value <%d>, assuming <1>\n", icells);
+			icells = 1;
+		}
 		for (i = 0, k = 0; i < nintr; i += icells, k++) {
 			intr[i] = ofw_bus_map_intr(dev, iparent, intr[i]);
 			resource_list_add(rl, SYS_RES_IRQ, k, intr[i], intr[i],