On Thu, Dec 18, 2025 at 12:10 PM Andrew Donnellan <[email protected]> wrote: > > [I will be leaving IBM in about a month from now, and will also be on leave > for most of that time starting tomorrow. I've cc'd my personal email, which > I am going to use for any kernel development I do after I leave, and also > Srish Srinivasan, who will be taking over some of my work.] > > Support page table check on PowerPC. Page table check tracks the usage of > of page table entries at each level 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. > > For now, we don't allow page table check alongside HUGETLB_PAGE, due to the > arch-specific complexity of set_huge_page_at(). (I'm sure I could figure > this out, but I have to get this version on this list before I leave my job.) > > This series was initially written by Rohan McLure, who has left IBM and > is no longer working on powerpc. > > v18: > * Rebase on mm-new > * Add instrumentation for pudp_invalidate() > * Add cleanup patch to use pte_advance_pfn() > * Move p{m,u}d_user_accessible_page() to a more sensible place in the code > * Disable when HUGETLB_PAGE is enabled
Thank you. This series looks good to me. Pasha
