of: Fix NULL dereference in unflatten_and_copy()
Check whether initial_boot_params is NULL before dereferencing it in
unflatten_and_copy_device_tree() for the case where no device tree is
available but the arch can still boot to a minimal usable system without
it. In this case also log a warning for when the kernel log buffer is
obtainable.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 2fa024b..758b4f8 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -922,8 +922,16 @@
*/
void __init unflatten_and_copy_device_tree(void)
{
- int size = __be32_to_cpu(initial_boot_params->totalsize);
- void *dt = early_init_dt_alloc_memory_arch(size,
+ int size;
+ void *dt;
+
+ if (!initial_boot_params) {
+ pr_warn("No valid device tree found, continuing without\n");
+ return;
+ }
+
+ size = __be32_to_cpu(initial_boot_params->totalsize);
+ dt = early_init_dt_alloc_memory_arch(size,
__alignof__(struct boot_param_header));
if (dt) {