Re: [PATCH mm v4 29/39] kasan, page_alloc: allow skipping memory init for HW_TAGS

Marco Elver
2021-12-21T12:12:05Z

On Mon, Dec 20, 2021 at 11:02PM +0100, andrey.konovalov@linux.dev wrote:
> From: Andrey Konovalov <andreyknvl@google.com>
[...]
> +static inline bool should_skip_init(gfp_t flags)
> +{
> + /* Don't skip if a software KASAN mode is enabled. */
> + if (IS_ENABLED(CONFIG_KASAN_GENERIC) ||
> + IS_ENABLED(CONFIG_KASAN_SW_TAGS))
> + return false;
> +
> + /* Don't skip, if hardware tag-based KASAN is not enabled. */
> + if (!kasan_hw_tags_enabled())
> + return false;

Why is the IS_ENABLED(CONFIG_KASAN_{GENERIC,SW_TAGS}) check above
required? Isn't kasan_hw_tags_enabled() always false if one of those is
configured?