Re: [PATCH] of: unflatten_and_copy: handle NULL initial_boot_params

From: Grant Likely
Date: Thu Nov 21 2013 - 07:39:37 EST


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?

Otherwise:

Acked-by: Grant Likely <grant.likely@xxxxxxxxxx>

But see my comments on Geert's "dt: Handle passed/built-in DT selection
in early_init_dt_scan()" patch.

g.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/