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

[Borislav Petkov <bp@alien8.de>]

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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