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

Andrey Konovalov
2021-12-30T19:11:48Z

On Tue, Dec 21, 2021 at 1:12 PM Marco Elver <elver@google.com> wrote:
>
> 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?

It is. I wanted to include those checks for completeness, but maybe
they just cause confusion instead. Will drop them in v5. Thanks!