[merged mm-stable] fs-proc-use-softleaf_has_pfn-in-pagemap-pmd-walker.patch removed from -mm tree

The quilt patch titled
     Subject: fs/proc: use softleaf_has_pfn() in pagemap PMD walker
has been removed from the -mm tree.  Its filename was
     fs-proc-use-softleaf_has_pfn-in-pagemap-pmd-walker.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Usama Arif <[email protected]>
Subject: fs/proc: use softleaf_has_pfn() in pagemap PMD walker
Date: Mon, 6 Jul 2026 04:42:05 -0700

pagemap_pmd_range_thp() assumes that every non-present PMD is a migration
entry and unconditionally calls softleaf_to_page().  This will crash on
any non-present PMD type that does not encode a PFN, such as the upcoming
PMD-level swap entries.

Guard the page lookup with softleaf_has_pfn(), matching how
pte_to_pagemap_entry() already handles non-present PTEs.

Link: https://lore.kernel.org/[email protected]
Signed-off-by: Usama Arif <[email protected]>
Acked-by: David Hildenbrand (Arm) <[email protected]>
Reviewed-by: Zi Yan <[email protected]>
Cc: Alexandre Ghiti <[email protected]>
Cc: Baolin Wang <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Barry Song <[email protected]>
Cc: Chris Li <[email protected]>
Cc: Dev Jain <[email protected]>
Cc: "Huang, Ying" <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Kairui Song <[email protected]>
Cc: Kemeng Shi <[email protected]>
Cc: Kiryl Shutsemau <[email protected]>
Cc: Lance Yang <[email protected]>
Cc: Liam R. Howlett <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Nhat Pham <[email protected]>
Cc: Nico Pache <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---

 fs/proc/task_mmu.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/proc/task_mmu.c~fs-proc-use-softleaf_has_pfn-in-pagemap-pmd-walker
+++ a/fs/proc/task_mmu.c
@@ -2129,7 +2129,8 @@ static int pagemap_pmd_range_thp(pmd_t *
 			flags |= PM_SOFT_DIRTY;
 		if (pmd_swp_uffd_wp(pmd))
 			flags |= PM_UFFD_WP;
-		page = softleaf_to_page(entry);
+		if (softleaf_has_pfn(entry))
+			page = softleaf_to_page(entry);
 	}
 
 	if (page) {
_

Patches currently in -mm which might be from [email protected] are

mm-mempolicy-skip-non-present-pmds-when-queueing-folios.patch
mm-madvise-skip-device-private-pmds-in-cold-and-pageout-walks.patch
mm-huge_memory-skip-device-private-pmds-in-madvise_free_huge_pmd.patch
mm-vmstat-mm-memcontrol-add-_monotonic-vmstat-readers.patch
mm-vmscan-reduce-lru_lock-contention-via-vmstat-derived-scan-balance-cost.patch