[PATCH v3] mm: pagewalk: Fix walk for hugepage tables

[Andrew Morton]

On Fri, 25 Jun 2021 05:10:12 +0000 (UTC) Christophe Leroy <christophe.leroy at csgroup.eu> wrote:

> Pagewalk ignores hugepd entries and walk down the tables
> as if it was traditionnal entries, leading to crazy result.
> 
> Add walk_hugepd_range() and use it to walk hugepage tables.

More details, please?  I assume "crazy result" is userspace visible? 
For how long has this bug existed?  Is a -stable backport needed?  Has
a Fixes: commit been identified?  etcetera!