Re: [PATCH] gendwarfksyms: Fix structure type overrides

[Petr Pavlu <petr.pavlu@suse.com>]

On 6/9/25 5:49 PM, Sami Tolvanen wrote:
> As we always iterate through the entire die_map when expanding
> type strings, recursively processing referenced types in
> type_expand_child() is not actually necessary. Furthermore,
> the type_string kABI rule added in commit c9083467f7b9
> ("gendwarfksyms: Add a kABI rule to override type strings") can
> fail to override type strings for structures due to a missing
> kabi_get_type_string() check in this function.
> 
> Fix the issue by dropping the unnecessary recursion and moving
> the override check to type_expand(). Note that symbol versions
> are otherwise unchanged with this patch.
> 
> Fixes: c9083467f7b9 ("gendwarfksyms: Add a kABI rule to override type strings")
> Reported-by: Giuliano Procida <gprocida@google.com>
> Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
> ---
>  scripts/gendwarfksyms/types.c | 65 ++++++++++-------------------------
>  1 file changed, 19 insertions(+), 46 deletions(-)
> 
> diff --git a/scripts/gendwarfksyms/types.c b/scripts/gendwarfksyms/types.c
> index 39ce1770e463..7bd459ea6c59 100644
> --- a/scripts/gendwarfksyms/types.c
> +++ b/scripts/gendwarfksyms/types.c
> @@ -333,37 +333,11 @@ static void calculate_version(struct version *version,
>  	cache_free(&expansion_cache);
>  }
>  
> -static void __type_expand(struct die *cache, struct type_expansion *type,
> -			  bool recursive);
> -
> -static void type_expand_child(struct die *cache, struct type_expansion *type,
> -			      bool recursive)
> -{
> -	struct type_expansion child;
> -	char *name;
> -
> -	name = get_type_name(cache);
> -	if (!name) {
> -		__type_expand(cache, type, recursive);
> -		return;
> -	}
> -
> -	if (recursive && !__cache_was_expanded(&expansion_cache, cache->addr)) {
> -		__cache_mark_expanded(&expansion_cache, cache->addr);
> -		type_expansion_init(&child);
> -		__type_expand(cache, &child, true);
> -		type_map_add(name, &child);
> -		type_expansion_free(&child);
> -	}

Nit: This code was the only user of __cache_was_expanded() and
__cache_mark_expanded(). It is now possible to merge
__cache_was_expanded() into cache_was_expanded() and
__cache_mark_expanded() into cache_mark_expanded().

Looks ok to me otherwise, feel free to add:

Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>

-- 
Thanks,
Petr