Hi Andrew,
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?
Thanks,
Andrew
--
Andrew Donnellan OzLabs, ADL Canberra
a...@linux.ibm.com IBM Australia Limited
