On 20/09/2024 05:54, Stefano Stabellini wrote:
>
>
> On Thu, 19 Sep 2024, Michal Orzel wrote:
>> Even though in most cases device nodes are not present directly under
>> the root node, it's a perfectly valid configuration (e.g. Qemu virt
>> machine dtb). At the moment, we don't handle this scenario which leads
>> to unconditional addition of extra leading '/' in the node full path.
>> This makes the attempt to add such device overlay to fail.
>>
>> Signed-off-by: Michal Orzel <michal.or...@amd.com>
>> ---
>> xen/common/dt-overlay.c | 16 +++++++++++-----
>> 1 file changed, 11 insertions(+), 5 deletions(-)
>>
>> diff --git a/xen/common/dt-overlay.c b/xen/common/dt-overlay.c
>> index d18bd12bd38d..63b28889de90 100644
>> --- a/xen/common/dt-overlay.c
>> +++ b/xen/common/dt-overlay.c
>> @@ -325,6 +325,7 @@ static int overlay_get_nodes_info(const void *fdto, char
>> **nodes_full_path)
>> int node_name_len;
>> unsigned int target_path_len = strlen(target_path);
>> unsigned int node_full_name_len;
>> + unsigned int extra_len;
>>
>> node_name = fdt_get_name(fdto, subnode, &node_name_len);
>>
>> @@ -332,10 +333,13 @@ static int overlay_get_nodes_info(const void *fdto,
>> char **nodes_full_path)
>> return node_name_len;
>>
>> /*
>> - * Magic number 2 is for adding '/' and '\0'. This is done to
>> keep
>> - * the node_full_path in the correct full node name format.
>> + * Extra length is for adding '/' and '\0' unless the target
>> path is
>> + * root in which case we don't add the '/' at the beginning.
>> This is
>> + * done to keep the node_full_path in the correct full node name
>> + * format.
>> */
>> - node_full_name_len = target_path_len + node_name_len + 2;
>> + extra_len = (target_path_len > 1) + 1;
>
> I'd prefer to avoid the implicit bool to int conversion. I think it is
> mandated by MISRA R10.1, we have a bool exception but I don't think it
> would cover this type of usage. For instance:
>
> extra_len = ((target_path_len > 1) ? 1 : 0) + 1;
>
> or
>
> extra_len = (target_path_len > 1) ? 2 : 1;
Ok, will do this version.
~Michal
