+ mm-prefer-mm-def_vma_flags-in-mm-logic.patch added to mm-new branch

+ mm-prefer-mm-def_vma_flags-in-mm-logic.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm: prefer mm->def_vma_flags in mm logic
has been added to the -mm mm-new branch.  Its filename is
     mm-prefer-mm-def_vma_flags-in-mm-logic.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-prefer-mm-def_vma_flags-in-mm-logic.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next

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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

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branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there most days

------------------------------------------------------
From: Lorenzo Stoakes <ljs@kernel.org>
Subject: mm: prefer mm->def_vma_flags in mm logic
Date: Sat, 11 Jul 2026 19:45:02 +0100

Currently mm->def_flags (of type vm_flags_t) is union'd with
mm->def_vma_flags (of type vma_flags_t).

As part of the effort to convert vm_flags_t usage to vma_flags_t (in order
to no longer be arbitrarily limited to a system word size for VMA flags),
prefer mm->def_vma_flags to mm->def_flags throughout the mm logic.

We update dump_mm() to use the %*pb format which means we make no
assumption about the number of VMA flag bits on output when outputting
default VMA flags.

No functional change intended.

Link: https://lore.kernel.org/20260711-b4-vma-flags-mm-v2-5-0fa2357d5431@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/debug.c |    5 +++--
 mm/mlock.c |   13 +++++++------
 mm/mmap.c  |   11 ++++++-----
 mm/vma.c   |    2 +-
 4 files changed, 17 insertions(+), 14 deletions(-)

--- a/mm/debug.c~mm-prefer-mm-def_vma_flags-in-mm-logic
+++ a/mm/debug.c
@@ -197,7 +197,7 @@ void dump_mm(const struct mm_struct *mm)
 		"numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n"
 #endif
 		"tlb_flush_pending %d\n"
-		"def_flags: %#lx(%pGv)\n",
+		"def_flags: %*pb(%pGv)\n",
 
 		mm, mm->task_size,
 		mm->mmap_base, mm->mmap_legacy_base,
@@ -226,7 +226,8 @@ void dump_mm(const struct mm_struct *mm)
 		mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq,
 #endif
 		atomic_read(&mm->tlb_flush_pending),
-		mm->def_flags, &mm->def_flags
+		NUM_VMA_FLAG_BITS, mm->def_vma_flags.__vma_flags,
+		&mm->def_vma_flags
 	);
 }
 EXPORT_SYMBOL(dump_mm);
--- a/mm/mlock.c~mm-prefer-mm-def_vma_flags-in-mm-logic
+++ a/mm/mlock.c
@@ -699,26 +699,27 @@ SYSCALL_DEFINE2(munlock, unsigned long,
 
 /*
  * Take the MCL_* flags passed into mlockall (or 0 if called from munlockall)
- * and translate into the appropriate modifications to mm->def_flags and/or the
- * flags for all current VMAs.
+ * and translate into the appropriate modifications to mm->def_vma_flags and/or
+ * the flags for all current VMAs.
  *
  * There are a couple of subtleties with this.  If mlockall() is called multiple
  * times with different flags, the values do not necessarily stack.  If mlockall
  * is called once including the MCL_FUTURE flag and then a second time without
- * it, VM_LOCKED and VM_LOCKONFAULT will be cleared from mm->def_flags.
+ * it, VM_LOCKED and VM_LOCKONFAULT will be cleared from mm->def_vma_flags.
  */
 static int apply_mlockall_flags(int flags)
 {
 	VMA_ITERATOR(vmi, current->mm, 0);
+	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma, *prev = NULL;
 	vm_flags_t to_add = 0;
 
-	current->mm->def_flags &= ~VM_LOCKED_MASK;
+	vma_flags_clear_mask(&mm->def_vma_flags, VMA_LOCKED_MASK);
 	if (flags & MCL_FUTURE) {
-		current->mm->def_flags |= VM_LOCKED;
+		vma_flags_set(&mm->def_vma_flags, VMA_LOCKED_BIT);
 
 		if (flags & MCL_ONFAULT)
-			current->mm->def_flags |= VM_LOCKONFAULT;
+			vma_flags_set(&mm->def_vma_flags, VMA_LOCKONFAULT_BIT);
 
 		if (!(flags & MCL_CURRENT))
 			goto out;
--- a/mm/mmap.c~mm-prefer-mm-def_vma_flags-in-mm-logic
+++ a/mm/mmap.c
@@ -102,15 +102,16 @@ void vma_set_page_prot(struct vm_area_st
  */
 static int check_brk_limits(unsigned long addr, unsigned long len)
 {
+	const struct mm_struct *mm = current->mm;
+	const bool is_def_locked =
+		vma_flags_test(&mm->def_vma_flags, VMA_LOCKED_BIT);
 	unsigned long mapped_addr;
 
 	mapped_addr = get_unmapped_area(NULL, addr, len, 0, MAP_FIXED);
 	if (IS_ERR_VALUE(mapped_addr))
 		return mapped_addr;
 
-	return mlock_future_ok(current->mm,
-			      current->mm->def_flags & VM_LOCKED, len)
-		? 0 : -EAGAIN;
+	return mlock_future_ok(mm, is_def_locked, len) ? 0 : -EAGAIN;
 }
 
 SYSCALL_DEFINE1(brk, unsigned long, brk)
@@ -197,7 +198,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
 		goto out;
 
 	mm->brk = brk;
-	if (mm->def_flags & VM_LOCKED)
+	if (vma_flags_test(&mm->def_vma_flags, VMA_LOCKED_BIT))
 		populate = true;
 
 success:
@@ -1247,7 +1248,7 @@ int vm_brk_flags(unsigned long addr, uns
 
 	vma = vma_prev(&vmi);
 	ret = do_brk_flags(&vmi, vma, addr, len, vma_flags);
-	populate = ((mm->def_flags & VM_LOCKED) != 0);
+	populate = vma_flags_test(&mm->def_vma_flags, VMA_LOCKED_BIT);
 	mmap_write_unlock(mm);
 	userfaultfd_unmap_complete(mm, &uf);
 	if (populate && !ret)
--- a/mm/vma.c~mm-prefer-mm-def_vma_flags-in-mm-logic
+++ a/mm/vma.c
@@ -3426,7 +3426,7 @@ struct vm_area_struct *__install_special
 	if (unlikely(vma == NULL))
 		return ERR_PTR(-ENOMEM);
 
-	vm_flags |= mm->def_flags | VM_DONTEXPAND;
+	vm_flags |= vma_flags_to_legacy(mm->def_vma_flags) | VM_DONTEXPAND;
 	if (pgtable_supports_soft_dirty())
 		vm_flags |= VM_SOFTDIRTY;
 	vm_flags_init(vma, vm_flags & ~VM_LOCKED_MASK);
_

Patches currently in -mm which might be from ljs@kernel.org are

mm-vmalloc-acquire-init_mm-lock-on-huge-vmap-to-avoid-ptdump-uaf.patch
x86-mm-pat-acquire-mmap-lock-on-page-table-free-to-avoid-ptdump-uaf.patch
mm-ptdump-always-stabilise-against-page-table-freeing-using-init_mm.patch
arm64-remove-redundant-concurrent-ptdump-uaf-mitigation.patch
mm-move-alloc-tag-to-mm.patch
mm-move-vma_start_pgoff-into-mmh-and-clean-up.patch
mm-add-kdoc-comments-for-vma_start-last_pgoff.patch
tools-testing-vma-use-vma_start_pgoff-in-merge-tests.patch
mm-introduce-and-use-vma_end_pgoff.patch
mm-rmap-update-mm-interval_treec-comments.patch
mm-rmap-parameterise-vma_interval_tree_-by-address_space.patch
mm-rmap-elide-unnecessary-static-inlines-in-interval_treec.patch
mm-rmap-rename-vma_interval_tree_-to-mapping_rmap_tree_.patch
mm-rmap-parameterise-anon_vma_interval_tree_-by-anon_vma.patch
mm-rmap-rename-anon_vma_interval_tree_-params-and-use-pgoff_t.patch
mm-rmap-rename-anon_vma_interval_tree_-to-anon_rmap_tree_.patch
maintainers-move-mm-interval_treec-to-rmap-section.patch
mm-vma-introduce-and-use-vmg_pages-vmg__pgoff.patch
mm-vma-clean-up-anon_vma_compatible.patch
mm-vma-refactor-vmg_adjust_set_range-for-clarity.patch
mm-vma-minor-cleanup-of-expand_.patch
mm-introduce-and-use-linear_page_delta.patch
mm-vma-use-vma_start_pgoff-linear_page_index-in-mm-code.patch
mm-prefer-vma__pgoff-to-vma-vm_pgoff-in-kernel.patch
mm-vma-remove-duplicative-vma_pgoff_offset-helper.patch
mm-use-linear_page_-consistently.patch
mm-vma-introduce-vma_assert_can_modify.patch
mm-vma-add-and-use-vma__pgoff.patch
mm-vma-move-__install_special_mapping-to-vmac.patch
mm-vma-make-vma_set_range-static-drop-insert_vm_struct-decl.patch
mm-vma-update-vma_shrink-to-not-pass-start-pgoff-parameters.patch
mm-vma-update-vmg_adjust_set_range-to-offset-pgoff-instead.patch
mm-vma-slightly-rework-the-anonymous-check-in-__mmap_new_vma.patch
mm-vma-introduce-and-use-vma_set_pgoff.patch
mm-vma-correct-incorrect-vmah-inclusion.patch
mm-vma-use-guard-clauses-in-can_vma_merge_.patch
tools-testing-vma-default-vma-mm-flag-bits-to-64-bit.patch
tools-testing-vma-output-compared-expression-on-assert_.patch
mm-introduce-vma_flags_can_grow-and-vma_can_grow.patch
mm-vma-update-do_mmap-to-use-vma_flags_t.patch
mm-convert-__get_unmapped_area-to-use-vma_flags_t.patch
mm-update-generic_get_unmapped_area-to-use-vma_flags_t.patch
mm-prefer-mm-def_vma_flags-in-mm-logic.patch
mm-vma-convert-vm_pgprot_modify-to-use-vma_flags_t-and-rename.patch
mm-vma-rename-vma_get_page_prot-to-vma_flags_to_page_prot.patch
mm-introduce-vma_get_page_prot-and-use-it.patch
mm-vma-update-create_init_stack_vma-to-use-vma_flags_t.patch
mm-vma-convert-miscellaneous-uses-of-vma-flags-in-core-mm.patch
mm-mlock-convert-mlock-code-to-use-vma_flags_t.patch
mm-mprotect-convert-mprotect-code-to-use-vma_flags_t.patch
mm-mremap-convert-mremap-code-to-use-vma_flags_t.patch