[PATCH 4/4] mm/kasan: make kasan=on|off take effect for all three modes

[Lorenzo Stoakes]

On Tue, Aug 12, 2025 at 09:27:02PM +0800, Baoquan He wrote:
> > Firstly I _LOVE_ the term 'ifdeffery scope'. Fantastic :)
>
> Learned from upstream people with expertise on both english and kernel, :-)

:)

> After investigation, I keep the CONFIG_KASAN_HW_TAGS ifdeffery scope out
> of CONFIG_KASAN scope. Otherwise, I need define the dummy
> kasan_hw_tags_enabled() function twice. I am personally not fan of the
> style. While if that is preferred in kernel, I can change it.
>
> #ifdef CONFIG_KASAN
>
> #ifdef CONFIG_KASAN_HW_TAGS
> ......
> #ifdef CONFIG_KASAN_HW_TAGS
> static inline bool kasan_hw_tags_enabled(void)
> {
>         return kasan_enabled();
> }
> #else /* CONFIG_KASAN_HW_TAGS */
> static inline bool kasan_hw_tags_enabled(void)
> {
>         return false;
> }
> #endif /* CONFIG_KASAN_HW_TAGS */
> .....
> #else /* CONFIG_KASAN */
> static inline bool kasan_hw_tags_enabled(void)
> {
>         return false;
> }
> #endif
>

This is fine, as CONFIG_KASAN_HW_TAGS implies CONFIG_KASAN anyway.