[PATCH v17 00/12] Support page table check on PowerPC

[Pasha Tatashin]

On Fri, Sep 26, 2025 at 8:17 AM Andrew Morton <akpm at linux-foundation.org> wrote:
>
> On Fri, 26 Sep 2025 08:42:35 +1000 Andrew Donnellan <ajd at linux.ibm.com> wrote:
>
> > On Tue, 2025-09-09 at 19:13 +1000, Andrew Donnellan wrote:
> > > Support page table check on all PowerPC platforms. This works by serialising
> > > assignments, reassignments and clears of page table entries at each level in
> > > order to ensure that anonymous mappings have at most one writable consumer,
> > > and likewise that file-backed mappings are not simultaneously also anonymous
> > > mappings.
> > >
> > > In order to support this infrastructure, a number of helpers or stubs must be
> > > defined or updated for all powerpc platforms. Additionally, we separate
> > > set_pte_at() and set_pte_at_unchecked(), to allow for internal, uninstrumented
> > > mappings.
> > >
> > > On some PowerPC platforms, implementing {pte,pmd,pud}_user_accessible_page()
> > > requires the address. We revert previous changes that removed the address
> > > parameter from various interfaces, and add it to some other interfaces,
> > > in order to allow this.
> > >
> > > Note that on 32 bit systems with CONFIG_KFENCE=y, you need [0] to avoid
> > > possible failures in init code (this is a code patching/static keys issue,
> > > which was discovered by a user testing this series but isn't a bug in page
> > > table check).
> > >
> > > (This series was initially written by Rohan McLure, who has left IBM and
> > > is no longer working on powerpc.)
> >
> > Is this likely to make it in in time for 6.18, or should I respin it post merge
> > window?
>
> The latter, please.

Andrew Donnelan, looks like the merge window missed again, could you
please re-send this series so we could get it into 6.20?

Thank you,
Pasha