Re: [PATCH] jump_label: constify jump_label_text_reserved and friends

[Jason Baron <jbaron@redhat.com>]

On Mon, Jan 07, 2013 at 08:58:09AM -0500, Sasha Levin wrote:
> jump_label_text_reserved() doesn't modify the memory it works on, it just
> checks whether there are any jump labels there.
> 
> Constify the parameters of it to prevent warnings when working with it.
> 

I don't see any 'const' data passed to jump_label_text_reserved()? Where is the
warning coming from? New users?

Also, does this mean 'ftrace_text_reserved()' and 'alternatives_text_reserved()'
need to be updated as well?

Thanks,

-Jason


> Reviewed-by: Jamie Iles <jamie.iles@oracle.com>
> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
> ---
>  include/linux/jump_label.h |  4 ++--
>  kernel/jump_label.c        | 10 ++++++----
>  2 files changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
> index 0976fc4..d917a2a 100644
> --- a/include/linux/jump_label.h
> +++ b/include/linux/jump_label.h
> @@ -116,7 +116,7 @@ extern void arch_jump_label_transform(struct jump_entry *entry,
>  				      enum jump_label_type type);
>  extern void arch_jump_label_transform_static(struct jump_entry *entry,
>  					     enum jump_label_type type);
> -extern int jump_label_text_reserved(void *start, void *end);
> +extern int jump_label_text_reserved(const void *start, const void *end);
>  extern void static_key_slow_inc(struct static_key *key);
>  extern void static_key_slow_dec(struct static_key *key);
>  extern void static_key_slow_dec_deferred(struct static_key_deferred *key);
> @@ -174,7 +174,7 @@ static inline void static_key_slow_dec_deferred(struct static_key_deferred *key)
>  	static_key_slow_dec(&key->key);
>  }
>  
> -static inline int jump_label_text_reserved(void *start, void *end)
> +static inline int jump_label_text_reserved(const void *start, const void *end)
>  {
>  	return 0;
>  }
> diff --git a/kernel/jump_label.c b/kernel/jump_label.c
> index 60f48fa..6dc71c6 100644
> --- a/kernel/jump_label.c
> +++ b/kernel/jump_label.c
> @@ -120,7 +120,8 @@ void jump_label_rate_limit(struct static_key_deferred *key,
>  }
>  EXPORT_SYMBOL_GPL(jump_label_rate_limit);
>  
> -static int addr_conflict(struct jump_entry *entry, void *start, void *end)
> +static int addr_conflict(struct jump_entry *entry,
> +				const void *start, const void *end)
>  {
>  	if (entry->code <= (unsigned long)end &&
>  		entry->code + JUMP_LABEL_NOP_SIZE > (unsigned long)start)
> @@ -130,7 +131,8 @@ static int addr_conflict(struct jump_entry *entry, void *start, void *end)
>  }
>  
>  static int __jump_label_text_reserved(struct jump_entry *iter_start,
> -		struct jump_entry *iter_stop, void *start, void *end)
> +		struct jump_entry *iter_stop,
> +		const void *start, const void *end)
>  {
>  	struct jump_entry *iter;
>  
> @@ -222,7 +224,7 @@ struct static_key_mod {
>  	struct module *mod;
>  };
>  
> -static int __jump_label_mod_text_reserved(void *start, void *end)
> +static int __jump_label_mod_text_reserved(const void *start, const void *end)
>  {
>  	struct module *mod;
>  
> @@ -419,7 +421,7 @@ early_initcall(jump_label_init_module);
>   *
>   * returns 1 if there is an overlap, 0 otherwise
>   */
> -int jump_label_text_reserved(void *start, void *end)
> +int jump_label_text_reserved(const void *start, const void *end)
>  {
>  	int ret = __jump_label_text_reserved(__start___jump_table,
>  			__stop___jump_table, start, end);
> -- 
> 1.8.0.2
>