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@xxxxxxxxxx> Cc: Grant Likely <grant.likely@xxxxxxxxxx> Cc: Rob Herring <rob.herring@xxxxxxxxxxx> Cc: devicetree@xxxxxxxxxxxxxxx Cc: linux-arch@xxxxxxxxxxxxxxx --- v2: * Log a warning for those who can obtain the kernel log buffer (Grant Likely). --- drivers/of/fdt.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 2fa024b97c43..758b4f8b30b7 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -922,8 +922,16 @@ void __init unflatten_device_tree(void) */ 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) { -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html