[merged mm-stable] mm-isolate-mmap-internal-logic-to-mm-vmac.patch removed from -mm tree

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

The quilt patch titled
     Subject: mm: isolate mmap internal logic to mm/vma.c
has been removed from the -mm tree.  Its filename was
     mm-isolate-mmap-internal-logic-to-mm-vmac.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: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Subject: mm: isolate mmap internal logic to mm/vma.c
Date: Fri, 25 Oct 2024 13:26:24 +0100

In previous commits we effected improvements to the mmap() logic in
mmap_region() and its newly introduced internal implementation function
__mmap_region().

However as these changes are intended to be backported, we kept the delta
as small as is possible and made as few changes as possible to the newly
introduced mm/vma.* files.

Take the opportunity to move this logic to mm/vma.c which not only
isolates it, but also makes it available for later userland testing which
can help us catch such logic errors far earlier.

Link: https://lkml.kernel.org/r/93fc2c3aa37dd30590b7e4ee067dfd832007bf7e.1729858176.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/mmap.c         |  234 -------------------------------
 mm/vma.c          |  323 +++++++++++++++++++++++++++++++++++++++++++-
 mm/vma.h          |   97 -------------
 mm/vma_internal.h |    5 
 4 files changed, 329 insertions(+), 330 deletions(-)

--- a/mm/mmap.c~mm-isolate-mmap-internal-logic-to-mm-vmac
+++ a/mm/mmap.c
@@ -577,22 +577,6 @@ SYSCALL_DEFINE1(old_mmap, struct mmap_ar
 }
 #endif /* __ARCH_WANT_SYS_OLD_MMAP */
 
-/*
- * We account for memory if it's a private writeable mapping,
- * not hugepages and VM_NORESERVE wasn't set.
- */
-static inline bool accountable_mapping(struct file *file, vm_flags_t vm_flags)
-{
-	/*
-	 * hugetlb has its own accounting separate from the core VM
-	 * VM_HUGETLB may not be set yet so we cannot check for that flag.
-	 */
-	if (file && is_file_hugepages(file))
-		return false;
-
-	return (vm_flags & (VM_NORESERVE | VM_SHARED | VM_WRITE)) == VM_WRITE;
-}
-
 /**
  * unmapped_area() - Find an area between the low_limit and the high_limit with
  * the correct alignment and offset, all from @info. Note: current->mm is used
@@ -1362,224 +1346,6 @@ int do_munmap(struct mm_struct *mm, unsi
 	return do_vmi_munmap(&vmi, mm, start, len, uf, false);
 }
 
-static unsigned long __mmap_region(struct file *file, unsigned long addr,
-		unsigned long len, vm_flags_t vm_flags, unsigned long pgoff,
-		struct list_head *uf)
-{
-	struct mm_struct *mm = current->mm;
-	struct vm_area_struct *vma = NULL;
-	pgoff_t pglen = PHYS_PFN(len);
-	unsigned long charged = 0;
-	struct vma_munmap_struct vms;
-	struct ma_state mas_detach;
-	struct maple_tree mt_detach;
-	unsigned long end = addr + len;
-	int error;
-	VMA_ITERATOR(vmi, mm, addr);
-	VMG_STATE(vmg, mm, &vmi, addr, end, vm_flags, pgoff);
-
-	vmg.file = file;
-	/* Find the first overlapping VMA */
-	vma = vma_find(&vmi, end);
-	init_vma_munmap(&vms, &vmi, vma, addr, end, uf, /* unlock = */ false);
-	if (vma) {
-		mt_init_flags(&mt_detach, vmi.mas.tree->ma_flags & MT_FLAGS_LOCK_MASK);
-		mt_on_stack(mt_detach);
-		mas_init(&mas_detach, &mt_detach, /* addr = */ 0);
-		/* Prepare to unmap any existing mapping in the area */
-		error = vms_gather_munmap_vmas(&vms, &mas_detach);
-		if (error)
-			goto gather_failed;
-
-		vmg.next = vms.next;
-		vmg.prev = vms.prev;
-		vma = NULL;
-	} else {
-		vmg.next = vma_iter_next_rewind(&vmi, &vmg.prev);
-	}
-
-	/* Check against address space limit. */
-	if (!may_expand_vm(mm, vm_flags, pglen - vms.nr_pages)) {
-		error = -ENOMEM;
-		goto abort_munmap;
-	}
-
-	/*
-	 * Private writable mapping: check memory availability
-	 */
-	if (accountable_mapping(file, vm_flags)) {
-		charged = pglen;
-		charged -= vms.nr_accounted;
-		if (charged) {
-			error = security_vm_enough_memory_mm(mm, charged);
-			if (error)
-				goto abort_munmap;
-		}
-
-		vms.nr_accounted = 0;
-		vm_flags |= VM_ACCOUNT;
-		vmg.flags = vm_flags;
-	}
-
-	/*
-	 * clear PTEs while the vma is still in the tree so that rmap
-	 * cannot race with the freeing later in the truncate scenario.
-	 * This is also needed for mmap_file(), which is why vm_ops
-	 * close function is called.
-	 */
-	vms_clean_up_area(&vms, &mas_detach);
-	vma = vma_merge_new_range(&vmg);
-	if (vma)
-		goto expanded;
-	/*
-	 * Determine the object being mapped and call the appropriate
-	 * specific mapper. the address has already been validated, but
-	 * not unmapped, but the maps are removed from the list.
-	 */
-	vma = vm_area_alloc(mm);
-	if (!vma) {
-		error = -ENOMEM;
-		goto unacct_error;
-	}
-
-	vma_iter_config(&vmi, addr, end);
-	vma_set_range(vma, addr, end, pgoff);
-	vm_flags_init(vma, vm_flags);
-	vma->vm_page_prot = vm_get_page_prot(vm_flags);
-
-	if (vma_iter_prealloc(&vmi, vma)) {
-		error = -ENOMEM;
-		goto free_vma;
-	}
-
-	if (file) {
-		vma->vm_file = get_file(file);
-		error = mmap_file(file, vma);
-		if (error)
-			goto unmap_and_free_file_vma;
-
-		/* Drivers cannot alter the address of the VMA. */
-		WARN_ON_ONCE(addr != vma->vm_start);
-		/*
-		 * Drivers should not permit writability when previously it was
-		 * disallowed.
-		 */
-		VM_WARN_ON_ONCE(vm_flags != vma->vm_flags &&
-				!(vm_flags & VM_MAYWRITE) &&
-				(vma->vm_flags & VM_MAYWRITE));
-
-		vma_iter_config(&vmi, addr, end);
-		/*
-		 * If vm_flags changed after mmap_file(), we should try merge
-		 * vma again as we may succeed this time.
-		 */
-		if (unlikely(vm_flags != vma->vm_flags && vmg.prev)) {
-			struct vm_area_struct *merge;
-
-			vmg.flags = vma->vm_flags;
-			/* If this fails, state is reset ready for a reattempt. */
-			merge = vma_merge_new_range(&vmg);
-
-			if (merge) {
-				/*
-				 * ->mmap() can change vma->vm_file and fput
-				 * the original file. So fput the vma->vm_file
-				 * here or we would add an extra fput for file
-				 * and cause general protection fault
-				 * ultimately.
-				 */
-				fput(vma->vm_file);
-				vm_area_free(vma);
-				vma = merge;
-				/* Update vm_flags to pick up the change. */
-				vm_flags = vma->vm_flags;
-				goto file_expanded;
-			}
-			vma_iter_config(&vmi, addr, end);
-		}
-
-		vm_flags = vma->vm_flags;
-	} else if (vm_flags & VM_SHARED) {
-		error = shmem_zero_setup(vma);
-		if (error)
-			goto free_iter_vma;
-	} else {
-		vma_set_anonymous(vma);
-	}
-
-#ifdef CONFIG_SPARC64
-	/* TODO: Fix SPARC ADI! */
-	WARN_ON_ONCE(!arch_validate_flags(vm_flags));
-#endif
-
-	/* Lock the VMA since it is modified after insertion into VMA tree */
-	vma_start_write(vma);
-	vma_iter_store(&vmi, vma);
-	mm->map_count++;
-	vma_link_file(vma);
-
-	/*
-	 * vma_merge_new_range() calls khugepaged_enter_vma() too, the below
-	 * call covers the non-merge case.
-	 */
-	khugepaged_enter_vma(vma, vma->vm_flags);
-
-file_expanded:
-	file = vma->vm_file;
-	ksm_add_vma(vma);
-expanded:
-	perf_event_mmap(vma);
-
-	/* Unmap any existing mapping in the area */
-	vms_complete_munmap_vmas(&vms, &mas_detach);
-
-	vm_stat_account(mm, vm_flags, pglen);
-	if (vm_flags & VM_LOCKED) {
-		if ((vm_flags & VM_SPECIAL) || vma_is_dax(vma) ||
-					is_vm_hugetlb_page(vma) ||
-					vma == get_gate_vma(current->mm))
-			vm_flags_clear(vma, VM_LOCKED_MASK);
-		else
-			mm->locked_vm += pglen;
-	}
-
-	if (file)
-		uprobe_mmap(vma);
-
-	/*
-	 * New (or expanded) vma always get soft dirty status.
-	 * Otherwise user-space soft-dirty page tracker won't
-	 * be able to distinguish situation when vma area unmapped,
-	 * then new mapped in-place (which must be aimed as
-	 * a completely new data area).
-	 */
-	vm_flags_set(vma, VM_SOFTDIRTY);
-
-	vma_set_page_prot(vma);
-
-	return addr;
-
-unmap_and_free_file_vma:
-	fput(vma->vm_file);
-	vma->vm_file = NULL;
-
-	vma_iter_set(&vmi, vma->vm_end);
-	/* Undo any partial mapping done by a device driver. */
-	unmap_region(&vmi.mas, vma, vmg.prev, vmg.next);
-free_iter_vma:
-	vma_iter_free(&vmi);
-free_vma:
-	vm_area_free(vma);
-unacct_error:
-	if (charged)
-		vm_unacct_memory(charged);
-
-abort_munmap:
-	vms_abort_munmap_vmas(&vms, &mas_detach);
-gather_failed:
-	return error;
-}
-
 unsigned long mmap_region(struct file *file, unsigned long addr,
 			  unsigned long len, vm_flags_t vm_flags, unsigned long pgoff,
 			  struct list_head *uf)
--- a/mm/vma.c~mm-isolate-mmap-internal-logic-to-mm-vmac
+++ a/mm/vma.c
@@ -1103,7 +1103,7 @@ static inline void vms_clear_ptes(struct
 	vms->clear_ptes = false;
 }
 
-void vms_clean_up_area(struct vma_munmap_struct *vms,
+static void vms_clean_up_area(struct vma_munmap_struct *vms,
 		struct ma_state *mas_detach)
 {
 	struct vm_area_struct *vma;
@@ -1126,7 +1126,7 @@ void vms_clean_up_area(struct vma_munmap
  * used for the munmap() and may downgrade the lock - if requested.  Everything
  * needed to be done once the vma maple tree is updated.
  */
-void vms_complete_munmap_vmas(struct vma_munmap_struct *vms,
+static void vms_complete_munmap_vmas(struct vma_munmap_struct *vms,
 		struct ma_state *mas_detach)
 {
 	struct vm_area_struct *vma;
@@ -1168,6 +1168,23 @@ void vms_complete_munmap_vmas(struct vma
 }
 
 /*
+ * reattach_vmas() - Undo any munmap work and free resources
+ * @mas_detach: The maple state with the detached maple tree
+ *
+ * Reattach any detached vmas and free up the maple tree used to track the vmas.
+ */
+static void reattach_vmas(struct ma_state *mas_detach)
+{
+	struct vm_area_struct *vma;
+
+	mas_set(mas_detach, 0);
+	mas_for_each(mas_detach, vma, ULONG_MAX)
+		vma_mark_detached(vma, false);
+
+	__mt_destroy(mas_detach->tree);
+}
+
+/*
  * vms_gather_munmap_vmas() - Put all VMAs within a range into a maple tree
  * for removal at a later date.  Handles splitting first and last if necessary
  * and marking the vmas as isolated.
@@ -1177,7 +1194,7 @@ void vms_complete_munmap_vmas(struct vma
  *
  * Return: 0 on success, error otherwise
  */
-int vms_gather_munmap_vmas(struct vma_munmap_struct *vms,
+static int vms_gather_munmap_vmas(struct vma_munmap_struct *vms,
 		struct ma_state *mas_detach)
 {
 	struct vm_area_struct *next = NULL;
@@ -1316,6 +1333,39 @@ map_count_exceeded:
 }
 
 /*
+ * init_vma_munmap() - Initializer wrapper for vma_munmap_struct
+ * @vms: The vma munmap struct
+ * @vmi: The vma iterator
+ * @vma: The first vm_area_struct to munmap
+ * @start: The aligned start address to munmap
+ * @end: The aligned end address to munmap
+ * @uf: The userfaultfd list_head
+ * @unlock: Unlock after the operation.  Only unlocked on success
+ */
+static void init_vma_munmap(struct vma_munmap_struct *vms,
+		struct vma_iterator *vmi, struct vm_area_struct *vma,
+		unsigned long start, unsigned long end, struct list_head *uf,
+		bool unlock)
+{
+	vms->vmi = vmi;
+	vms->vma = vma;
+	if (vma) {
+		vms->start = start;
+		vms->end = end;
+	} else {
+		vms->start = vms->end = 0;
+	}
+	vms->unlock = unlock;
+	vms->uf = uf;
+	vms->vma_count = 0;
+	vms->nr_pages = vms->locked_vm = vms->nr_accounted = 0;
+	vms->exec_vm = vms->stack_vm = vms->data_vm = 0;
+	vms->unmap_start = FIRST_USER_ADDRESS;
+	vms->unmap_end = USER_PGTABLES_CEILING;
+	vms->clear_ptes = false;
+}
+
+/*
  * do_vmi_align_munmap() - munmap the aligned region from @start to @end.
  * @vmi: The vma iterator
  * @vma: The starting vm_area_struct
@@ -2069,3 +2119,270 @@ void mm_drop_all_locks(struct mm_struct
 
 	mutex_unlock(&mm_all_locks_mutex);
 }
+
+/*
+ * We account for memory if it's a private writeable mapping,
+ * not hugepages and VM_NORESERVE wasn't set.
+ */
+static bool accountable_mapping(struct file *file, vm_flags_t vm_flags)
+{
+	/*
+	 * hugetlb has its own accounting separate from the core VM
+	 * VM_HUGETLB may not be set yet so we cannot check for that flag.
+	 */
+	if (file && is_file_hugepages(file))
+		return false;
+
+	return (vm_flags & (VM_NORESERVE | VM_SHARED | VM_WRITE)) == VM_WRITE;
+}
+
+/*
+ * vms_abort_munmap_vmas() - Undo as much as possible from an aborted munmap()
+ * operation.
+ * @vms: The vma unmap structure
+ * @mas_detach: The maple state with the detached maple tree
+ *
+ * Reattach any detached vmas, free up the maple tree used to track the vmas.
+ * If that's not possible because the ptes are cleared (and vm_ops->closed() may
+ * have been called), then a NULL is written over the vmas and the vmas are
+ * removed (munmap() completed).
+ */
+static void vms_abort_munmap_vmas(struct vma_munmap_struct *vms,
+		struct ma_state *mas_detach)
+{
+	struct ma_state *mas = &vms->vmi->mas;
+
+	if (!vms->nr_pages)
+		return;
+
+	if (vms->clear_ptes)
+		return reattach_vmas(mas_detach);
+
+	/*
+	 * Aborting cannot just call the vm_ops open() because they are often
+	 * not symmetrical and state data has been lost.  Resort to the old
+	 * failure method of leaving a gap where the MAP_FIXED mapping failed.
+	 */
+	mas_set_range(mas, vms->start, vms->end - 1);
+	mas_store_gfp(mas, NULL, GFP_KERNEL|__GFP_NOFAIL);
+	/* Clean up the insertion of the unfortunate gap */
+	vms_complete_munmap_vmas(vms, mas_detach);
+}
+
+unsigned long __mmap_region(struct file *file, unsigned long addr,
+		unsigned long len, vm_flags_t vm_flags, unsigned long pgoff,
+		struct list_head *uf)
+{
+	struct mm_struct *mm = current->mm;
+	struct vm_area_struct *vma = NULL;
+	pgoff_t pglen = PHYS_PFN(len);
+	unsigned long charged = 0;
+	struct vma_munmap_struct vms;
+	struct ma_state mas_detach;
+	struct maple_tree mt_detach;
+	unsigned long end = addr + len;
+	int error;
+	VMA_ITERATOR(vmi, mm, addr);
+	VMG_STATE(vmg, mm, &vmi, addr, end, vm_flags, pgoff);
+
+	vmg.file = file;
+	/* Find the first overlapping VMA */
+	vma = vma_find(&vmi, end);
+	init_vma_munmap(&vms, &vmi, vma, addr, end, uf, /* unlock = */ false);
+	if (vma) {
+		mt_init_flags(&mt_detach, vmi.mas.tree->ma_flags & MT_FLAGS_LOCK_MASK);
+		mt_on_stack(mt_detach);
+		mas_init(&mas_detach, &mt_detach, /* addr = */ 0);
+		/* Prepare to unmap any existing mapping in the area */
+		error = vms_gather_munmap_vmas(&vms, &mas_detach);
+		if (error)
+			goto gather_failed;
+
+		vmg.next = vms.next;
+		vmg.prev = vms.prev;
+		vma = NULL;
+	} else {
+		vmg.next = vma_iter_next_rewind(&vmi, &vmg.prev);
+	}
+
+	/* Check against address space limit. */
+	if (!may_expand_vm(mm, vm_flags, pglen - vms.nr_pages)) {
+		error = -ENOMEM;
+		goto abort_munmap;
+	}
+
+	/*
+	 * Private writable mapping: check memory availability
+	 */
+	if (accountable_mapping(file, vm_flags)) {
+		charged = pglen;
+		charged -= vms.nr_accounted;
+		if (charged) {
+			error = security_vm_enough_memory_mm(mm, charged);
+			if (error)
+				goto abort_munmap;
+		}
+
+		vms.nr_accounted = 0;
+		vm_flags |= VM_ACCOUNT;
+		vmg.flags = vm_flags;
+	}
+
+	/*
+	 * clear PTEs while the vma is still in the tree so that rmap
+	 * cannot race with the freeing later in the truncate scenario.
+	 * This is also needed for mmap_file(), which is why vm_ops
+	 * close function is called.
+	 */
+	vms_clean_up_area(&vms, &mas_detach);
+	vma = vma_merge_new_range(&vmg);
+	if (vma)
+		goto expanded;
+	/*
+	 * Determine the object being mapped and call the appropriate
+	 * specific mapper. the address has already been validated, but
+	 * not unmapped, but the maps are removed from the list.
+	 */
+	vma = vm_area_alloc(mm);
+	if (!vma) {
+		error = -ENOMEM;
+		goto unacct_error;
+	}
+
+	vma_iter_config(&vmi, addr, end);
+	vma_set_range(vma, addr, end, pgoff);
+	vm_flags_init(vma, vm_flags);
+	vma->vm_page_prot = vm_get_page_prot(vm_flags);
+
+	if (vma_iter_prealloc(&vmi, vma)) {
+		error = -ENOMEM;
+		goto free_vma;
+	}
+
+	if (file) {
+		vma->vm_file = get_file(file);
+		error = mmap_file(file, vma);
+		if (error)
+			goto unmap_and_free_file_vma;
+
+		/* Drivers cannot alter the address of the VMA. */
+		WARN_ON_ONCE(addr != vma->vm_start);
+		/*
+		 * Drivers should not permit writability when previously it was
+		 * disallowed.
+		 */
+		VM_WARN_ON_ONCE(vm_flags != vma->vm_flags &&
+				!(vm_flags & VM_MAYWRITE) &&
+				(vma->vm_flags & VM_MAYWRITE));
+
+		vma_iter_config(&vmi, addr, end);
+		/*
+		 * If vm_flags changed after mmap_file(), we should try merge
+		 * vma again as we may succeed this time.
+		 */
+		if (unlikely(vm_flags != vma->vm_flags && vmg.prev)) {
+			struct vm_area_struct *merge;
+
+			vmg.flags = vma->vm_flags;
+			/* If this fails, state is reset ready for a reattempt. */
+			merge = vma_merge_new_range(&vmg);
+
+			if (merge) {
+				/*
+				 * ->mmap() can change vma->vm_file and fput
+				 * the original file. So fput the vma->vm_file
+				 * here or we would add an extra fput for file
+				 * and cause general protection fault
+				 * ultimately.
+				 */
+				fput(vma->vm_file);
+				vm_area_free(vma);
+				vma = merge;
+				/* Update vm_flags to pick up the change. */
+				vm_flags = vma->vm_flags;
+				goto file_expanded;
+			}
+			vma_iter_config(&vmi, addr, end);
+		}
+
+		vm_flags = vma->vm_flags;
+	} else if (vm_flags & VM_SHARED) {
+		error = shmem_zero_setup(vma);
+		if (error)
+			goto free_iter_vma;
+	} else {
+		vma_set_anonymous(vma);
+	}
+
+#ifdef CONFIG_SPARC64
+	/* TODO: Fix SPARC ADI! */
+	WARN_ON_ONCE(!arch_validate_flags(vm_flags));
+#endif
+
+	/* Lock the VMA since it is modified after insertion into VMA tree */
+	vma_start_write(vma);
+	vma_iter_store(&vmi, vma);
+	mm->map_count++;
+	vma_link_file(vma);
+
+	/*
+	 * vma_merge_new_range() calls khugepaged_enter_vma() too, the below
+	 * call covers the non-merge case.
+	 */
+	khugepaged_enter_vma(vma, vma->vm_flags);
+
+file_expanded:
+	file = vma->vm_file;
+	ksm_add_vma(vma);
+expanded:
+	perf_event_mmap(vma);
+
+	/* Unmap any existing mapping in the area */
+	vms_complete_munmap_vmas(&vms, &mas_detach);
+
+	vm_stat_account(mm, vm_flags, pglen);
+	if (vm_flags & VM_LOCKED) {
+		if ((vm_flags & VM_SPECIAL) || vma_is_dax(vma) ||
+					is_vm_hugetlb_page(vma) ||
+					vma == get_gate_vma(current->mm))
+			vm_flags_clear(vma, VM_LOCKED_MASK);
+		else
+			mm->locked_vm += pglen;
+	}
+
+	if (file)
+		uprobe_mmap(vma);
+
+	/*
+	 * New (or expanded) vma always get soft dirty status.
+	 * Otherwise user-space soft-dirty page tracker won't
+	 * be able to distinguish situation when vma area unmapped,
+	 * then new mapped in-place (which must be aimed as
+	 * a completely new data area).
+	 */
+	vm_flags_set(vma, VM_SOFTDIRTY);
+
+	vma_set_page_prot(vma);
+
+	return addr;
+
+unmap_and_free_file_vma:
+	fput(vma->vm_file);
+	vma->vm_file = NULL;
+
+	vma_iter_set(&vmi, vma->vm_end);
+	/* Undo any partial mapping done by a device driver. */
+	unmap_region(&vmi.mas, vma, vmg.prev, vmg.next);
+free_iter_vma:
+	vma_iter_free(&vmi);
+free_vma:
+	vm_area_free(vma);
+unacct_error:
+	if (charged)
+		vm_unacct_memory(charged);
+
+abort_munmap:
+	vms_abort_munmap_vmas(&vms, &mas_detach);
+gather_failed:
+	return error;
+}
--- a/mm/vma.h~mm-isolate-mmap-internal-logic-to-mm-vmac
+++ a/mm/vma.h
@@ -165,99 +165,6 @@ static inline int vma_iter_store_gfp(str
 	return 0;
 }
 
-#ifdef CONFIG_MMU
-/*
- * init_vma_munmap() - Initializer wrapper for vma_munmap_struct
- * @vms: The vma munmap struct
- * @vmi: The vma iterator
- * @vma: The first vm_area_struct to munmap
- * @start: The aligned start address to munmap
- * @end: The aligned end address to munmap
- * @uf: The userfaultfd list_head
- * @unlock: Unlock after the operation.  Only unlocked on success
- */
-static inline void init_vma_munmap(struct vma_munmap_struct *vms,
-		struct vma_iterator *vmi, struct vm_area_struct *vma,
-		unsigned long start, unsigned long end, struct list_head *uf,
-		bool unlock)
-{
-	vms->vmi = vmi;
-	vms->vma = vma;
-	if (vma) {
-		vms->start = start;
-		vms->end = end;
-	} else {
-		vms->start = vms->end = 0;
-	}
-	vms->unlock = unlock;
-	vms->uf = uf;
-	vms->vma_count = 0;
-	vms->nr_pages = vms->locked_vm = vms->nr_accounted = 0;
-	vms->exec_vm = vms->stack_vm = vms->data_vm = 0;
-	vms->unmap_start = FIRST_USER_ADDRESS;
-	vms->unmap_end = USER_PGTABLES_CEILING;
-	vms->clear_ptes = false;
-}
-#endif
-
-int vms_gather_munmap_vmas(struct vma_munmap_struct *vms,
-		struct ma_state *mas_detach);
-
-void vms_complete_munmap_vmas(struct vma_munmap_struct *vms,
-		struct ma_state *mas_detach);
-
-void vms_clean_up_area(struct vma_munmap_struct *vms,
-		struct ma_state *mas_detach);
-
-/*
- * reattach_vmas() - Undo any munmap work and free resources
- * @mas_detach: The maple state with the detached maple tree
- *
- * Reattach any detached vmas and free up the maple tree used to track the vmas.
- */
-static inline void reattach_vmas(struct ma_state *mas_detach)
-{
-	struct vm_area_struct *vma;
-
-	mas_set(mas_detach, 0);
-	mas_for_each(mas_detach, vma, ULONG_MAX)
-		vma_mark_detached(vma, false);
-
-	__mt_destroy(mas_detach->tree);
-}
-
-/*
- * vms_abort_munmap_vmas() - Undo as much as possible from an aborted munmap()
- * operation.
- * @vms: The vma unmap structure
- * @mas_detach: The maple state with the detached maple tree
- *
- * Reattach any detached vmas, free up the maple tree used to track the vmas.
- * If that's not possible because the ptes are cleared (and vm_ops->closed() may
- * have been called), then a NULL is written over the vmas and the vmas are
- * removed (munmap() completed).
- */
-static inline void vms_abort_munmap_vmas(struct vma_munmap_struct *vms,
-		struct ma_state *mas_detach)
-{
-	struct ma_state *mas = &vms->vmi->mas;
-	if (!vms->nr_pages)
-		return;
-
-	if (vms->clear_ptes)
-		return reattach_vmas(mas_detach);
-
-	/*
-	 * Aborting cannot just call the vm_ops open() because they are often
-	 * not symmetrical and state data has been lost.  Resort to the old
-	 * failure method of leaving a gap where the MAP_FIXED mapping failed.
-	 */
-	mas_set_range(mas, vms->start, vms->end - 1);
-	mas_store_gfp(mas, NULL, GFP_KERNEL|__GFP_NOFAIL);
-	/* Clean up the insertion of the unfortunate gap */
-	vms_complete_munmap_vmas(vms, mas_detach);
-}
-
 int
 do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
 		    struct mm_struct *mm, unsigned long start,
@@ -336,6 +243,10 @@ bool vma_wants_writenotify(struct vm_are
 int mm_take_all_locks(struct mm_struct *mm);
 void mm_drop_all_locks(struct mm_struct *mm);
 
+unsigned long __mmap_region(struct file *file, unsigned long addr,
+		unsigned long len, vm_flags_t vm_flags, unsigned long pgoff,
+		struct list_head *uf);
+
 static inline bool vma_wants_manual_pte_write_upgrade(struct vm_area_struct *vma)
 {
 	/*
--- a/mm/vma_internal.h~mm-isolate-mmap-internal-logic-to-mm-vmac
+++ a/mm/vma_internal.h
@@ -17,8 +17,10 @@
 #include <linux/file.h>
 #include <linux/fs.h>
 #include <linux/huge_mm.h>
+#include <linux/hugetlb.h>
 #include <linux/hugetlb_inline.h>
 #include <linux/kernel.h>
+#include <linux/ksm.h>
 #include <linux/khugepaged.h>
 #include <linux/list.h>
 #include <linux/maple_tree.h>
@@ -32,11 +34,14 @@
 #include <linux/mmu_context.h>
 #include <linux/mutex.h>
 #include <linux/pagemap.h>
+#include <linux/perf_event.h>
 #include <linux/pfn.h>
 #include <linux/rcupdate.h>
 #include <linux/rmap.h>
 #include <linux/rwsem.h>
 #include <linux/sched/signal.h>
+#include <linux/security.h>
+#include <linux/shmem_fs.h>
 #include <linux/swap.h>
 #include <linux/uprobes.h>
 #include <linux/userfaultfd_k.h>
_

Patches currently in -mm which might be from lorenzo.stoakes@oracle.com are

mm-pagewalk-add-the-ability-to-install-ptes.patch
mm-add-pte_marker_guard-pte-marker.patch
mm-madvise-implement-lightweight-guard-page-mechanism.patch
tools-testing-update-tools-uapi-header-for-mman-commonh.patch
selftests-mm-add-self-tests-for-guard-page-feature.patch
mm-remove-unnecessary-page_table_lock-on-stack-expansion.patch