kernel: Add check to of_scan_flat_dt() before accessing initial_boot_params

Fixes a bug that affects rt288x

Signed-off-by: Tobias Wolf <dev-NTEO@vplace.de>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
This commit is contained in:
Felix Fietkau 2016-11-30 17:00:14 +01:00
parent b3c5db79eb
commit 832fb99da2

View file

@ -0,0 +1,30 @@
From: Tobias Wolf <dev-NTEO@vplace.de>
Date: Wed, 23 Nov 2016 10:40:07 +0100
Subject: [PATCH] of: Add check to of_scan_flat_dt() before accessing
initial_boot_params
An empty __dtb_start to __dtb_end section might result in initial_boot_params
being null for arch/mips/ralink. This showed that the boot process hangs
indefinitely in of_scan_flat_dt().
Signed-off-by: Tobias Wolf <dev-NTEO@vplace.de>
---
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -632,9 +632,12 @@ int __init of_scan_flat_dt(int (*it)(uns
const char *pathp;
int offset, rc = 0, depth = -1;
- for (offset = fdt_next_node(blob, -1, &depth);
- offset >= 0 && depth >= 0 && !rc;
- offset = fdt_next_node(blob, offset, &depth)) {
+ if (!blob)
+ return 0;
+
+ for (offset = fdt_next_node(blob, -1, &depth);
+ offset >= 0 && depth >= 0 && !rc;
+ offset = fdt_next_node(blob, offset, &depth)) {
pathp = fdt_get_name(blob, offset, NULL);
if (*pathp == '/')