[merged mm-stable] mm-huge_memory-dont-ignore-queried-cachemode-in-vmf_insert_pfn_pud.patch removed from -mm tree

[Andrew Morton <akpm@linux-foundation.org>]

The quilt patch titled
     Subject: mm/huge_memory: don't ignore queried cachemode in vmf_insert_pfn_pud()
has been removed from the -mm tree.  Its filename was
     mm-huge_memory-dont-ignore-queried-cachemode-in-vmf_insert_pfn_pud.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: David Hildenbrand <david@redhat.com>
Subject: mm/huge_memory: don't ignore queried cachemode in vmf_insert_pfn_pud()
Date: Fri, 13 Jun 2025 11:27:00 +0200

Patch series "mm/huge_memory: vmf_insert_folio_*() and
vmf_insert_pfn_pud() fixes", v3.

While working on improving vm_normal_page() and friends, I stumbled over
this issues: refcounted "normal" folios must not be marked using
pmd_special() / pud_special().  Otherwise, we're effectively telling the
system that these folios are no "normal", violating the rules we
documented for vm_normal_page().

Fortunately, there are not many pmd_special()/pud_special() users yet.  So
far there doesn't seem to be serious damage.

Tested using the ndctl tests ("ndctl:dax" suite).


This patch (of 3):

We set up the cache mode but ...  don't forward the updated pgprot to
insert_pfn_pud().

Only a problem on x86-64 PAT when mapping PFNs using PUDs that require a
special cachemode.

Fix it by using the proper pgprot where the cachemode was setup.

It is unclear in which configurations we would get the cachemode wrong:
through vfio seems possible.  Getting cachemodes wrong is usually ... 
bad.  As the fix is easy, let's backport it to stable.

Identified by code inspection.

Link: https://lkml.kernel.org/r/20250613092702.1943533-1-david@redhat.com
Link: https://lkml.kernel.org/r/20250613092702.1943533-2-david@redhat.com
Fixes: 7b806d229ef1 ("mm: remove vmf_insert_pfn_xxx_prot() for huge page-table entries")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/huge_memory.c |    7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

--- a/mm/huge_memory.c~mm-huge_memory-dont-ignore-queried-cachemode-in-vmf_insert_pfn_pud
+++ a/mm/huge_memory.c
@@ -1516,10 +1516,9 @@ static pud_t maybe_pud_mkwrite(pud_t pud
 }
 
 static void insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
-		pud_t *pud, pfn_t pfn, bool write)
+		pud_t *pud, pfn_t pfn, pgprot_t prot, bool write)
 {
 	struct mm_struct *mm = vma->vm_mm;
-	pgprot_t prot = vma->vm_page_prot;
 	pud_t entry;
 
 	if (!pud_none(*pud)) {
@@ -1581,7 +1580,7 @@ vm_fault_t vmf_insert_pfn_pud(struct vm_
 	pfnmap_setup_cachemode_pfn(pfn_t_to_pfn(pfn), &pgprot);
 
 	ptl = pud_lock(vma->vm_mm, vmf->pud);
-	insert_pfn_pud(vma, addr, vmf->pud, pfn, write);
+	insert_pfn_pud(vma, addr, vmf->pud, pfn, pgprot, write);
 	spin_unlock(ptl);
 
 	return VM_FAULT_NOPAGE;
@@ -1625,7 +1624,7 @@ vm_fault_t vmf_insert_folio_pud(struct v
 		add_mm_counter(mm, mm_counter_file(folio), HPAGE_PUD_NR);
 	}
 	insert_pfn_pud(vma, addr, vmf->pud, pfn_to_pfn_t(folio_pfn(folio)),
-		write);
+		       vma->vm_page_prot, write);
 	spin_unlock(ptl);
 
 	return VM_FAULT_NOPAGE;
_

Patches currently in -mm which might be from david@redhat.com are

mm-balloon_compaction-we-cannot-have-isolated-pages-in-the-balloon-list.patch
mm-balloon_compaction-convert-balloon_page_delete-to-balloon_page_finalize.patch
mm-zsmalloc-drop-pageisolated-related-vm_bug_ons.patch
mm-page_alloc-let-page-freeing-clear-any-set-page-type.patch
mm-balloon_compaction-make-pageoffline-sticky-until-the-page-is-freed.patch
mm-zsmalloc-make-pagezsmalloc-sticky-until-the-page-is-freed.patch
mm-migrate-rename-isolate_movable_page-to-isolate_movable_ops_page.patch
mm-migrate-rename-putback_movable_folio-to-putback_movable_ops_page.patch
mm-migrate-factor-out-movable_ops-page-handling-into-migrate_movable_ops_page.patch
mm-migrate-remove-folio_test_movable-and-folio_movable_ops.patch
mm-migrate-move-movable_ops-page-handling-out-of-move_to_new_folio.patch
mm-zsmalloc-stop-using-__clearpagemovable.patch
mm-balloon_compaction-stop-using-__clearpagemovable.patch
mm-migrate-remove-__clearpagemovable.patch
mm-migration-remove-pagemovable.patch
mm-rename-__pagemovable-to-page_has_movable_ops.patch
mm-page_isolation-drop-__folio_test_movable-check-for-large-folios.patch
mm-remove-__folio_test_movable.patch
mm-stop-storing-migration_ops-in-page-mapping.patch
mm-convert-movable-flag-in-page-mapping-to-a-page-flag.patch
mm-rename-pg_isolated-to-pg_movable_ops_isolated.patch
mm-page-flags-rename-page_mapping_movable-to-page_mapping_anon_ksm.patch
mm-page-alloc-remove-pagemappingflags.patch
mm-page-flags-remove-folio_mapping_flags.patch
mm-simplify-folio_expected_ref_count.patch
mm-rename-page_mapping_-to-folio_mapping_.patch
docs-mm-convert-from-non-lru-page-migration-to-movable_ops-page-migration.patch
mm-balloon_compaction-movable_ops-doc-updates.patch
mm-balloon_compaction-provide-single-balloon_page_insert-and-balloon_mapping_gfp_mask.patch
mm-convert-fpb_ignore_-into-fpb_respect_.patch
mm-smaller-folio_pte_batch-improvements.patch
mm-split-folio_pte_batch-into-folio_pte_batch-and-folio_pte_batch_flags.patch
mm-remove-boolean-output-parameters-from-folio_pte_batch_ext.patch
mm-memory-introduce-is_huge_zero_pfn-and-use-it-in-vm_normal_page_pmd.patch