The quilt patch titled Subject: fs/proc/task_mmu: fix PAGE_IS_PFNZERO detection for the huge zero folio has been removed from the -mm tree. Its filename was fs-proc-task_mmu-fix-page_is_pfnzero-detection-for-the-huge-zero-folio.patch
This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------ From: David Hildenbrand david@redhat.com Subject: fs/proc/task_mmu: fix PAGE_IS_PFNZERO detection for the huge zero folio Date: Tue, 17 Jun 2025 16:35:32 +0200
is_zero_pfn() does not work for the huge zero folio. Fix it by using is_huge_zero_pmd().
This can cause the PAGEMAP_SCAN ioctl against /proc/pid/pagemap to present pages as PAGE_IS_PRESENT rather than as PAGE_IS_PFNZERO.
Found by code inspection.
Link: https://lkml.kernel.org/r/20250617143532.2375383-1-david@redhat.com Fixes: 52526ca7fdb9 ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs") Signed-off-by: David Hildenbrand david@redhat.com Cc: Muhammad Usama Anjum usama.anjum@collabora.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
fs/proc/task_mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/proc/task_mmu.c~fs-proc-task_mmu-fix-page_is_pfnzero-detection-for-the-huge-zero-folio +++ a/fs/proc/task_mmu.c @@ -2182,7 +2182,7 @@ static unsigned long pagemap_thp_categor categories |= PAGE_IS_FILE; }
- if (is_zero_pfn(pmd_pfn(pmd))) + if (is_huge_zero_pmd(pmd)) categories |= PAGE_IS_PFNZERO; if (pmd_soft_dirty(pmd)) categories |= PAGE_IS_SOFT_DIRTY; _
Patches currently in -mm which might be from david@redhat.com are
mm-gup-remove-vm_bug_ons.patch mm-gup-remove-vm_bug_ons-fix.patch mm-huge_memory-dont-ignore-queried-cachemode-in-vmf_insert_pfn_pud.patch mm-huge_memory-dont-mark-refcounted-folios-special-in-vmf_insert_folio_pmd.patch mm-huge_memory-dont-mark-refcounted-folios-special-in-vmf_insert_folio_pud.patch