Re: [PATCH v9 10/44] kasan: define KASAN_GRANULE_PAGE

From: Andrey Konovalov
Date: Wed Nov 11 2020 - 20:36:54 EST


On Wed, Nov 11, 2020 at 8:05 PM Marco Elver <elver@xxxxxxxxxx> wrote:
>
> On Wed, 11 Nov 2020 at 19:48, Andrey Konovalov <andreyknvl@xxxxxxxxxx> wrote:
> >
> > On Wed, Nov 11, 2020 at 3:13 PM Alexander Potapenko <glider@xxxxxxxxxx> wrote:
> > >
> > > On Tue, Nov 10, 2020 at 11:11 PM Andrey Konovalov <andreyknvl@xxxxxxxxxx> wrote:
> > > >
> > > > Define KASAN_GRANULE_PAGE as (KASAN_GRANULE_SIZE << PAGE_SHIFT), which is
> > > > the same as (KASAN_GRANULE_SIZE * PAGE_SIZE), and use it across KASAN code
> > > > to simplify it.
> > >
> > > What's the physical sense behind KASAN_GRANULE_PAGE? Is it something
> > > more than just a product of two constants?
> >
> > No, just a product.
> >
> > > The name suggests it might be something page-sized, but in reality it is not.
> >
> > What name would you prefer?
>
> Is it actually KASAN_GRANULES_PER_SHADOW_PAGE ? AFAIK we're trying
> to calculate the granules that we can fit into a page of shadow
> memory.

Not exactly, it's the amount of memory, not the number of granules.

Will name it KASAN_MEMORY_PER_SHADOW_PAGE in v10.