On 21/11/13 12:39, Grant Likely wrote:
> On Tue, 19 Nov 2013 12:58:12 +0000, James Hogan <james.hogan@xxxxxxxxxx> wrote:
>> 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.
>>
>> 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
>> ---
>> drivers/of/fdt.c | 10 ++++++++--
>> 1 file changed, 8 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
>> index 2fa024b97c43..ac4983955e6d 100644
>> --- a/drivers/of/fdt.c
>> +++ b/drivers/of/fdt.c
>> @@ -922,8 +922,14 @@ 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)
>> + return;
>
> Worth logging a message for those who can obtain the kernel log
> buffer?
Yes, sounds reasonable (especially since for Meta the platform name detected from DT doesn't get logged in this case and I still get the console out via JTAG probe).
I'll post a v2 adding this:
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index ac4983955e6d..758b4f8b30b7 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -925,8 +925,10 @@ void __init unflatten_and_copy_device_tree(void)
int size;
void *dt;
- if (!initial_boot_params)
+ 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,
> Otherwise:
>
> Acked-by: Grant Likely <grant.likely@xxxxxxxxxx>
Thanks
James
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