Re: [PATCH V4 2/9] jump_label: Add the jump_label_can_update_check() helper

[Borislav Petkov]

On Thu, Feb 07, 2019 at 02:21:09PM +0100, Daniel Bristot de Oliveira wrote:
> diff --git a/kernel/jump_label.c b/kernel/jump_label.c
> index 288d630da22d..1e6f4d27e28d 100644
> --- a/kernel/jump_label.c
> +++ b/kernel/jump_label.c
> @@ -374,22 +374,29 @@ static enum jump_label_type jump_label_type(struct 
> jump_entry *entry)
>       return enabled ^ branch;
>  }
>  
> +static bool jump_label_can_update(struct jump_entry *entry, bool init)
> +{
> +     /*
> +      * Cannot update code that was in an init text area.
> +      */
> +     if (!init || jump_entry_is_init(entry))

Shouldn't this be &&

?

> +             return false;
> +
> +     if (WARN_ONCE(!kernel_text_address(jump_entry_code(entry)),
> +                      "can't patch jump_label at %pS", (void 
> *)jump_entry_code(entry)))
> +             return false;

Yeah, I think that this way of writing it is less readable than:

        if (!kernel_text_address(jump_entry_code(entry))) {
                WARN_ONCE(1, "can't patch jump_label at %pS", (void 
*)jump_entry_code(entry));
                return false;
        }

> +             if (jump_label_can_update(entry, init)) {
> +                     arch_jump_label_transform(entry, 
> jump_label_type(entry));

Yap.

Thx.

-- 
Regards/Gruss,
    Boris.

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