[PATCH v2] riscv: module: use a plain variable for list_head instead of a pointer

[laokz]

On Wed, 2024-11-27 at 15:25 +0100, Clément Léger wrote:
> rel_head's list_head member, rel_entry, doesn't need to be allocated,
> its storage can just be part of the allocated rel_head. Remove the

Oh my poor English. OK, it's more better than just add the lost kfree.

> pointer which allows to get rid of the allocation as well as an
> existing
> memory leak found by Kai Zang using kmemleak.
                            ^
                           Zhang

BTW. Doesn't it need a fixes tag like what you suggested? (The bug
might come from 6.7)

> 
> Reported-by: Kai Zhang <zhangkai at iscas.ac.cn>
> Signed-off-by: Clément Léger <cleger at rivosinc.com>
> Reviewed-by: Andrew Jones <ajones at ventanamicro.com>
> ---
> 
> V2:
>  - Add Kai Reported-by
>  - Reword the commit description (Andrew)
> 
> ---
>  arch/riscv/kernel/module.c | 18 ++++--------------
>  1 file changed, 4 insertions(+), 14 deletions(-)
> 
> diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
> index 1cd461f3d872..47d0ebeec93c 100644
> --- a/arch/riscv/kernel/module.c
> +++ b/arch/riscv/kernel/module.c
> @@ -23,7 +23,7 @@ struct used_bucket {
>  
>  struct relocation_head {
>         struct hlist_node node;
> -       struct list_head *rel_entry;
> +       struct list_head rel_entry;
>         void *location;
>  };
>  
> @@ -634,7 +634,7 @@ process_accumulated_relocations(struct module
> *me,
>                         location = rel_head_iter->location;
>                         list_for_each_entry_safe(rel_entry_iter,
>                                                  rel_entry_iter_tmp,
> -                                                rel_head_iter-
> >rel_entry,
> +                                                &rel_head_iter-
> >rel_entry,
>                                                  head) {
>                                 curr_type = rel_entry_iter->type;
>                                 reloc_handlers[curr_type].reloc_handl
> er(
> @@ -704,16 +704,7 @@ static int add_relocation_to_accumulate(struct
> module *me, int type,
>                         return -ENOMEM;
>                 }
>  
> -               rel_head->rel_entry =
> -                       kmalloc(sizeof(struct list_head),
> GFP_KERNEL);
> -
> -               if (!rel_head->rel_entry) {
> -                       kfree(entry);
> -                       kfree(rel_head);
> -                       return -ENOMEM;
> -               }
> -
> -               INIT_LIST_HEAD(rel_head->rel_entry);
> +               INIT_LIST_HEAD(&rel_head->rel_entry);
>                 rel_head->location = location;
>                 INIT_HLIST_NODE(&rel_head->node);
>                 if (!current_head->first) {
> @@ -722,7 +713,6 @@ static int add_relocation_to_accumulate(struct
> module *me, int type,
>  
>                         if (!bucket) {
>                                 kfree(entry);
> -                               kfree(rel_head->rel_entry);
>                                 kfree(rel_head);
>                                 return -ENOMEM;
>                         }
> @@ -735,7 +725,7 @@ static int add_relocation_to_accumulate(struct
> module *me, int type,
>         }
>  
>         /* Add relocation to head of discovered rel_head */
> -       list_add_tail(&entry->head, rel_head->rel_entry);
> +       list_add_tail(&entry->head, &rel_head->rel_entry);
>  
>         return 0;
>  }