On Wed, Mar 24, 2021 at 9:04 AM Changbin Du <changbin.du@xxxxxxxxx> wrote:
>
> The setup_arch() would invoke unflatten_device_tree() even no
> valid fdt found. So we'd better check it first and return early.
>
> Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>
> ---
> drivers/of/fdt.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
> index dcc1dd96911a..05d439d63bc5 100644
> --- a/drivers/of/fdt.c
> +++ b/drivers/of/fdt.c
> @@ -1225,6 +1225,11 @@ bool __init early_init_dt_scan(void *params)
> */
> void __init unflatten_device_tree(void)
> {
> + if (!initial_boot_params) {
> + pr_warn("No valid device tree found, continuing without\n");
How are you going to see this message if you have no DT?
> + return;
And the arch is supposed to just continue on oblivious that it has no DT?
> + }
> +
> __unflatten_device_tree(initial_boot_params, NULL, &of_root,
> early_init_dt_alloc_memory_arch, false);
Soon as you get here with a NULL initial_boot_params, you'll get a
backtrace and halt.
>
> --
> 2.30.2
>
