Re: [PATCH 3/4] dt-overlay: Remove ASSERT_UNREACHABLE from add_nodes()

[Julien Grall <julien@xxxxxxx>]

Hi Michal,

On 19/09/2024 12:42, Michal Orzel wrote:
> The assumption stated in the comment that the code will never get there
> is incorrect. It's enough for the target-path to be incorrect (i.e. user
> error), which will lead to an incorrect overall node path and we will end
> up in this "unreachable" place causing a failure in debug builds.
Looking at the caller, nodes_full_path contain path that was computed 
from the overlay. So I would have assumed the path would be part of the 
new DT. What did I miss?
> Fixes: 0c0facdab6f5 ("xen/arm: Implement device tree node addition 
> functionalities")
> Signed-off-by: Michal Orzel <michal.orzel@xxxxxxx>
> ---
>   xen/common/dt-overlay.c | 4 ----
>   1 file changed, 4 deletions(-)
>
> diff --git a/xen/common/dt-overlay.c b/xen/common/dt-overlay.c
> index 8606b14d1e8e..d18bd12bd38d 100644
> --- a/xen/common/dt-overlay.c
> +++ b/xen/common/dt-overlay.c
> @@ -596,11 +596,7 @@ static long add_nodes(struct overlay_track *tr, char 
> **nodes_full_path)
>           overlay_node = dt_find_node_by_path_from(tr->dt_host_new,
>                                                    nodes_full_path[j]);
>           if ( overlay_node == NULL )
> -        {
> -            /* Sanity check. But code will never come here. */
> -            ASSERT_UNREACHABLE();
>               return -EFAULT;
> -        }
>   
>           /*
>            * Find previous and next node to overlay_node in dt_host_new. We will
Cheers,

--
Julien Grall