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 vPxBaDTR 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: TL;DR - To make life easier, I squashed the two patches and asked Andrew to take it with my R-b,T-b tags attached, hope that's ok with you Chris. It takes your work, combines commit msgs and the code into one patch with correct attribution to you. See https://lore.kernel.org/linux-mm/a1e787dd-b911-474d-8570-f37685357d86@lucifer.local/ Thanks, Lorenzo On Mon, Mar 02, 2026 at 05:34:47PM +0000, Lorenzo Stoakes wrote: > On Thu, Feb 26, 2026 at 10:16:47PM +0800, Chris Down wrote: > > After commit d82d09e48219 ("mm/huge_memory: mark PMD mappings of the > > huge zero folio special"), moved huge zero PMDs must remain special so > > vm_normal_page_pmd() continues to treat them as special mappings. > > > > move_pages_huge_pmd() currently reconstructs the destination PMD in the > > huge zero page branch, which drops PMD state such as pmd_special() on > > architectures with CONFIG_ARCH_HAS_PTE_SPECIAL. As a result, > > vm_normal_page_pmd() can treat the moved huge zero PMD as a normal page > > and corrupt its refcount. > > > > Instead of reconstructing the PMD from the folio, derive the destination > > entry from src_pmdval after pmdp_huge_clear_flush(), then handle the PMD > > metadata the same way move_huge_pmd() does for moved entries by marking > > it soft-dirty and clearing uffd-wp. > > > > Fixes: d82d09e48219 ("mm/huge_memory: mark PMD mappings of the huge zero folio special") > > Cc: stable@vger.kernel.org > > Signed-off-by: Chris Down > > --- > > mm/huge_memory.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > > index fed57951a7cd..8166b5e871ad 100644 > > --- a/mm/huge_memory.c > > +++ b/mm/huge_memory.c > > @@ -2794,7 +2794,8 @@ int move_pages_huge_pmd(struct mm_struct *mm, pmd_t *dst_pmd, pmd_t *src_pmd, pm > > _dst_pmd = pmd_mkwrite(pmd_mkdirty(_dst_pmd), dst_vma); > > } else { > > src_pmdval = pmdp_huge_clear_flush(src_vma, src_addr, src_pmd); > > - _dst_pmd = folio_mk_pmd(page_folio(src_page), dst_vma->vm_page_prot); > > + _dst_pmd = move_soft_dirty_pmd(src_pmdval); > > + _dst_pmd = clear_uffd_wp_pmd(_dst_pmd); > > I'm confused as to what's going on here, it seems like the 2/3 is simply > updating the 1/3 with a different fixes? > > I agree with David that just moving it is probably completely fine, so I think > this should be the only actual patch you need, and you can just Fixes: > e3981db444a0 with it? Then make this a v3 series with 2 patches this + the test > right (but maybe best not backport the test :)? > > > } > > set_pmd_at(mm, dst_addr, dst_pmd, _dst_pmd); > > > > -- > > 2.51.2 > > > > > >