Merge tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Daniel Verkamp has contributed a memfd series ("mm/memfd: add
   F_SEAL_EXEC") which permits the setting of the memfd execute bit at
   memfd creation time, with the option of sealing the state of the X
   bit.

 - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset()
   thread-safe for pmd unshare") which addresses a rare race condition
   related to PMD unsharing.

 - Several folioification patch serieses from Matthew Wilcox, Vishal
   Moola, Sidhartha Kumar and Lorenzo Stoakes

 - Johannes Weiner has a series ("mm: push down lock_page_memcg()")
   which does perform some memcg maintenance and cleanup work.

 - SeongJae Park has added DAMOS filtering to DAMON, with the series
   "mm/damon/core: implement damos filter".

   These filters provide users with finer-grained control over DAMOS's
   actions. SeongJae has also done some DAMON cleanup work.

 - Kairui Song adds a series ("Clean up and fixes for swap").

 - Vernon Yang contributed the series "Clean up and refinement for maple
   tree".

 - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It
   adds to MGLRU an LRU of memcgs, to improve the scalability of global
   reclaim.

 - David Hildenbrand has added some userfaultfd cleanup work in the
   series "mm: uffd-wp + change_protection() cleanups".

 - Christoph Hellwig has removed the generic_writepages() library
   function in the series "remove generic_writepages".

 - Baolin Wang has performed some maintenance on the compaction code in
   his series "Some small improvements for compaction".

 - Sidhartha Kumar is doing some maintenance work on struct page in his
   series "Get rid of tail page fields".

 - David Hildenbrand contributed some cleanup, bugfixing and
   generalization of pte management and of pte debugging in his series
   "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with
   swap PTEs".

 - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation
   flag in the series "Discard __GFP_ATOMIC".

 - Sergey Senozhatsky has improved zsmalloc's memory utilization with
   his series "zsmalloc: make zspage chain size configurable".

 - Joey Gouly has added prctl() support for prohibiting the creation of
   writeable+executable mappings.

   The previous BPF-based approach had shortcomings. See "mm: In-kernel
   support for memory-deny-write-execute (MDWE)".

 - Waiman Long did some kmemleak cleanup and bugfixing in the series
   "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF".

 - T.J. Alumbaugh has contributed some MGLRU cleanup work in his series
   "mm: multi-gen LRU: improve".

 - Jiaqi Yan has provided some enhancements to our memory error
   statistics reporting, mainly by presenting the statistics on a
   per-node basis. See the series "Introduce per NUMA node memory error
   statistics".

 - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog
   regression in compaction via his series "Fix excessive CPU usage
   during compaction".

 - Christoph Hellwig does some vmalloc maintenance work in the series
   "cleanup vfree and vunmap".

 - Christoph Hellwig has removed block_device_operations.rw_page() in
   ths series "remove ->rw_page".

 - We get some maple_tree improvements and cleanups in Liam Howlett's
   series "VMA tree type safety and remove __vma_adjust()".

 - Suren Baghdasaryan has done some work on the maintainability of our
   vm_flags handling in the series "introduce vm_flags modifier
   functions".

 - Some pagemap cleanup and generalization work in Mike Rapoport's
   series "mm, arch: add generic implementation of pfn_valid() for
   FLATMEM" and "fixups for generic implementation of pfn_valid()"

 - Baoquan He has done some work to make /proc/vmallocinfo and
   /proc/kcore better represent the real state of things in his series
   "mm/vmalloc.c: allow vread() to read out vm_map_ram areas".

 - Jason Gunthorpe rationalized the GUP system's interface to the rest
   of the kernel in the series "Simplify the external interface for
   GUP".

 - SeongJae Park wishes to migrate people from DAMON's debugfs interface
   over to its sysfs interface. To support this, we'll temporarily be
   printing warnings when people use the debugfs interface. See the
   series "mm/damon: deprecate DAMON debugfs interface".

 - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes
   and clean-ups" series.

 - Huang Ying has provided a dramatic reduction in migration's TLB flush
   IPI rates with the series "migrate_pages(): batch TLB flushing".

 - Arnd Bergmann has some objtool fixups in "objtool warning fixes".

* tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits)
  include/linux/migrate.h: remove unneeded externs
  mm/memory_hotplug: cleanup return value handing in do_migrate_range()
  mm/uffd: fix comment in handling pte markers
  mm: change to return bool for isolate_movable_page()
  mm: hugetlb: change to return bool for isolate_hugetlb()
  mm: change to return bool for isolate_lru_page()
  mm: change to return bool for folio_isolate_lru()
  objtool: add UACCESS exceptions for __tsan_volatile_read/write
  kmsan: disable ftrace in kmsan core code
  kasan: mark addr_has_metadata __always_inline
  mm: memcontrol: rename memcg_kmem_enabled()
  sh: initialize max_mapnr
  m68k/nommu: add missing definition of ARCH_PFN_OFFSET
  mm: percpu: fix incorrect size in pcpu_obj_full_size()
  maple_tree: reduce stack usage with gcc-9 and earlier
  mm: page_alloc: call panic() when memoryless node allocation fails
  mm: multi-gen LRU: avoid futile retries
  migrate_pages: move THP/hugetlb migration support check to simplify code
  migrate_pages: batch flushing TLB
  migrate_pages: share more code between _unmap and _move
  ...

1 files changed, 82 insertions, 115 deletions

diff --git a/mm/nommu.c b/mm/nommu.c
index 5b83938ecb67..57ba243c6a37 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -173,7 +173,7 @@ static void *__vmalloc_user_flags(unsigned long size, gfp_t flags)
 		mmap_write_lock(current->mm);
 		vma = find_vma(current->mm, (unsigned long)ret);
 		if (vma)
-			vma->vm_flags |= VM_USERMAP;
+			vm_flags_set(vma, VM_USERMAP);
 		mmap_write_unlock(current->mm);
 	}
 
@@ -544,19 +544,6 @@ static void put_nommu_region(struct vm_region *region)
 	__put_nommu_region(region);
 }
 
-void vma_mas_store(struct vm_area_struct *vma, struct ma_state *mas)
-{
-	mas_set_range(mas, vma->vm_start, vma->vm_end - 1);
-	mas_store_prealloc(mas, vma);
-}
-
-void vma_mas_remove(struct vm_area_struct *vma, struct ma_state *mas)
-{
-	mas->index = vma->vm_start;
-	mas->last = vma->vm_end - 1;
-	mas_store_prealloc(mas, NULL);
-}
-
 static void setup_vma_to_mm(struct vm_area_struct *vma, struct mm_struct *mm)
 {
 	vma->vm_mm = mm;
@@ -573,44 +560,6 @@ static void setup_vma_to_mm(struct vm_area_struct *vma, struct mm_struct *mm)
 	}
 }
 
-/*
- * mas_add_vma_to_mm() - Maple state variant of add_mas_to_mm().
- * @mas: The maple state with preallocations.
- * @mm: The mm_struct
- * @vma: The vma to add
- *
- */
-static void mas_add_vma_to_mm(struct ma_state *mas, struct mm_struct *mm,
-			      struct vm_area_struct *vma)
-{
-	BUG_ON(!vma->vm_region);
-
-	setup_vma_to_mm(vma, mm);
-	mm->map_count++;
-
-	/* add the VMA to the tree */
-	vma_mas_store(vma, mas);
-}
-
-/*
- * add a VMA into a process's mm_struct in the appropriate place in the list
- * and tree and add to the address space's page tree also if not an anonymous
- * page
- * - should be called with mm->mmap_lock held writelocked
- */
-static int add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
-{
-	MA_STATE(mas, &mm->mm_mt, vma->vm_start, vma->vm_end);
-
-	if (mas_preallocate(&mas, vma, GFP_KERNEL)) {
-		pr_warn("Allocation of vma tree for process %d failed\n",
-		       current->pid);
-		return -ENOMEM;
-	}
-	mas_add_vma_to_mm(&mas, mm, vma);
-	return 0;
-}
-
 static void cleanup_vma_from_mm(struct vm_area_struct *vma)
 {
 	vma->vm_mm->map_count--;
@@ -626,14 +575,15 @@ static void cleanup_vma_from_mm(struct vm_area_struct *vma)
 		i_mmap_unlock_write(mapping);
 	}
 }
+
 /*
  * delete a VMA from its owning mm_struct and address space
  */
 static int delete_vma_from_mm(struct vm_area_struct *vma)
 {
-	MA_STATE(mas, &vma->vm_mm->mm_mt, 0, 0);
+	VMA_ITERATOR(vmi, vma->vm_mm, vma->vm_start);
 
-	if (mas_preallocate(&mas, vma, GFP_KERNEL)) {
+	if (vma_iter_prealloc(&vmi)) {
 		pr_warn("Allocation of vma tree for process %d failed\n",
 		       current->pid);
 		return -ENOMEM;
@@ -641,10 +591,9 @@ static int delete_vma_from_mm(struct vm_area_struct *vma)
 	cleanup_vma_from_mm(vma);
 
 	/* remove from the MM's tree and list */
-	vma_mas_remove(vma, &mas);
+	vma_iter_clear(&vmi, vma->vm_start, vma->vm_end);
 	return 0;
 }
-
 /*
  * destroy a VMA record
  */
@@ -675,9 +624,9 @@ EXPORT_SYMBOL(find_vma_intersection);
  */
 struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
 {
-	MA_STATE(mas, &mm->mm_mt, addr, addr);
+	VMA_ITERATOR(vmi, mm, addr);
 
-	return mas_walk(&mas);
+	return vma_iter_load(&vmi);
 }
 EXPORT_SYMBOL(find_vma);
 
@@ -709,9 +658,9 @@ static struct vm_area_struct *find_vma_exact(struct mm_struct *mm,
 {
 	struct vm_area_struct *vma;
 	unsigned long end = addr + len;
-	MA_STATE(mas, &mm->mm_mt, addr, addr);
+	VMA_ITERATOR(vmi, mm, addr);
 
-	vma = mas_walk(&mas);
+	vma = vma_iter_load(&vmi);
 	if (!vma)
 		return NULL;
 	if (vma->vm_start != addr)
@@ -892,29 +841,36 @@ static unsigned long determine_vm_flags(struct file *file,
 	unsigned long vm_flags;
 
 	vm_flags = calc_vm_prot_bits(prot, 0) | calc_vm_flag_bits(flags);
-	/* vm_flags |= mm->def_flags; */
 
-	if (!(capabilities & NOMMU_MAP_DIRECT)) {
-		/* attempt to share read-only copies of mapped file chunks */
+	if (!file) {
+		/*
+		 * MAP_ANONYMOUS. MAP_SHARED is mapped to MAP_PRIVATE, because
+		 * there is no fork().
+		 */
 		vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
-		if (file && !(prot & PROT_WRITE))
-			vm_flags |= VM_MAYSHARE;
+	} else if (flags & MAP_PRIVATE) {
+		/* MAP_PRIVATE file mapping */
+		if (capabilities & NOMMU_MAP_DIRECT)
+			vm_flags |= (capabilities & NOMMU_VMFLAGS);
+		else
+			vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
+
+		if (!(prot & PROT_WRITE) && !current->ptrace)
+			/*
+			 * R/O private file mapping which cannot be used to
+			 * modify memory, especially also not via active ptrace
+			 * (e.g., set breakpoints) or later by upgrading
+			 * permissions (no mprotect()). We can try overlaying
+			 * the file mapping, which will work e.g., on chardevs,
+			 * ramfs/tmpfs/shmfs and romfs/cramf.
+			 */
+			vm_flags |= VM_MAYOVERLAY;
 	} else {
-		/* overlay a shareable mapping on the backing device or inode
-		 * if possible - used for chardevs, ramfs/tmpfs/shmfs and
-		 * romfs/cramfs */
-		vm_flags |= VM_MAYSHARE | (capabilities & NOMMU_VMFLAGS);
-		if (flags & MAP_SHARED)
-			vm_flags |= VM_SHARED;
+		/* MAP_SHARED file mapping: NOMMU_MAP_DIRECT is set. */
+		vm_flags |= VM_SHARED | VM_MAYSHARE |
+			    (capabilities & NOMMU_VMFLAGS);
 	}
 
-	/* refuse to let anyone share private mappings with this process if
-	 * it's being traced - otherwise breakpoints set in it may interfere
-	 * with another untraced process
-	 */
-	if ((flags & MAP_PRIVATE) && current->ptrace)
-		vm_flags &= ~VM_MAYSHARE;
-
 	return vm_flags;
 }
 
@@ -952,15 +908,18 @@ static int do_mmap_private(struct vm_area_struct *vma,
 	void *base;
 	int ret, order;
 
-	/* invoke the file's mapping function so that it can keep track of
-	 * shared mappings on devices or memory
-	 * - VM_MAYSHARE will be set if it may attempt to share
+	/*
+	 * Invoke the file's mapping function so that it can keep track of
+	 * shared mappings on devices or memory. VM_MAYOVERLAY will be set if
+	 * it may attempt to share, which will make is_nommu_shared_mapping()
+	 * happy.
 	 */
 	if (capabilities & NOMMU_MAP_DIRECT) {
 		ret = call_mmap(vma->vm_file, vma);
+		/* shouldn't return success if we're not sharing */
+		if (WARN_ON_ONCE(!is_nommu_shared_mapping(vma->vm_flags)))
+			ret = -ENOSYS;
 		if (ret == 0) {
-			/* shouldn't return success if we're not sharing */
-			BUG_ON(!(vma->vm_flags & VM_MAYSHARE));
 			vma->vm_region->vm_top = vma->vm_region->vm_end;
 			return 0;
 		}
@@ -991,7 +950,8 @@ static int do_mmap_private(struct vm_area_struct *vma,
 
 	atomic_long_add(total, &mmap_pages_allocated);
 
-	region->vm_flags = vma->vm_flags |= VM_MAPPED_COPY;
+	vm_flags_set(vma, VM_MAPPED_COPY);
+	region->vm_flags = vma->vm_flags;
 	region->vm_start = (unsigned long) base;
 	region->vm_end   = region->vm_start + len;
 	region->vm_top   = region->vm_start + (total << PAGE_SHIFT);
@@ -1052,7 +1012,7 @@ unsigned long do_mmap(struct file *file,
 	vm_flags_t vm_flags;
 	unsigned long capabilities, result;
 	int ret;
-	MA_STATE(mas, &current->mm->mm_mt, 0, 0);
+	VMA_ITERATOR(vmi, current->mm, 0);
 
 	*populate = 0;
 
@@ -1081,14 +1041,14 @@ unsigned long do_mmap(struct file *file,
 	if (!vma)
 		goto error_getting_vma;
 
-	if (mas_preallocate(&mas, vma, GFP_KERNEL))
-		goto error_maple_preallocate;
+	if (vma_iter_prealloc(&vmi))
+		goto error_vma_iter_prealloc;
 
 	region->vm_usage = 1;
 	region->vm_flags = vm_flags;
 	region->vm_pgoff = pgoff;
 
-	vma->vm_flags = vm_flags;
+	vm_flags_init(vma, vm_flags);
 	vma->vm_pgoff = pgoff;
 
 	if (file) {
@@ -1106,7 +1066,7 @@ unsigned long do_mmap(struct file *file,
 	 *   these cases, sharing is handled in the driver or filesystem rather
 	 *   than here
 	 */
-	if (vm_flags & VM_MAYSHARE) {
+	if (is_nommu_shared_mapping(vm_flags)) {
 		struct vm_region *pregion;
 		unsigned long pglen, rpglen, pgend, rpgend, start;
 
@@ -1116,7 +1076,7 @@ unsigned long do_mmap(struct file *file,
 		for (rb = rb_first(&nommu_region_tree); rb; rb = rb_next(rb)) {
 			pregion = rb_entry(rb, struct vm_region, vm_rb);
 
-			if (!(pregion->vm_flags & VM_MAYSHARE))
+			if (!is_nommu_shared_mapping(pregion->vm_flags))
 				continue;
 
 			/* search for overlapping mappings on the same file */
@@ -1152,7 +1112,7 @@ unsigned long do_mmap(struct file *file,
 			vma->vm_end = start + len;
 
 			if (pregion->vm_flags & VM_MAPPED_COPY)
-				vma->vm_flags |= VM_MAPPED_COPY;
+				vm_flags_set(vma, VM_MAPPED_COPY);
 			else {
 				ret = do_mmap_shared_file(vma);
 				if (ret < 0) {
@@ -1224,7 +1184,11 @@ unsigned long do_mmap(struct file *file,
 	current->mm->total_vm += len >> PAGE_SHIFT;
 
 share:
-	mas_add_vma_to_mm(&mas, current->mm, vma);
+	BUG_ON(!vma->vm_region);
+	setup_vma_to_mm(vma, current->mm);
+	current->mm->map_count++;
+	/* add the VMA to the tree */
+	vma_iter_store(&vmi, vma);
 
 	/* we flush the region from the icache only when the first executable
 	 * mapping of it is made  */
@@ -1240,7 +1204,7 @@ share:
 error_just_free:
 	up_write(&nommu_region_sem);
 error:
-	mas_destroy(&mas);
+	vma_iter_free(&vmi);
 	if (region->vm_file)
 		fput(region->vm_file);
 	kmem_cache_free(vm_region_jar, region);
@@ -1268,7 +1232,7 @@ error_getting_region:
 	show_free_areas(0, NULL);
 	return -ENOMEM;
 
-error_maple_preallocate:
+error_vma_iter_prealloc:
 	kmem_cache_free(vm_region_jar, region);
 	vm_area_free(vma);
 	pr_warn("Allocation of vma tree for process %d failed\n", current->pid);
@@ -1334,13 +1298,13 @@ SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg)
  * split a vma into two pieces at address 'addr', a new vma is allocated either
  * for the first part or the tail.
  */
-int split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
+int split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
 	      unsigned long addr, int new_below)
 {
 	struct vm_area_struct *new;
 	struct vm_region *region;
 	unsigned long npages;
-	MA_STATE(mas, &mm->mm_mt, vma->vm_start, vma->vm_end);
+	struct mm_struct *mm;
 
 	/* we're only permitted to split anonymous regions (these should have
 	 * only a single usage on the region) */
@@ -1359,10 +1323,10 @@ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
 	if (!new)
 		goto err_vma_dup;
 
-	if (mas_preallocate(&mas, vma, GFP_KERNEL)) {
+	if (vma_iter_prealloc(vmi)) {
 		pr_warn("Allocation of vma tree for process %d failed\n",
 			current->pid);
-		goto err_mas_preallocate;
+		goto err_vmi_preallocate;
 	}
 
 	/* most fields are the same, copy all, and then fixup */
@@ -1396,13 +1360,11 @@ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
 
 	setup_vma_to_mm(vma, mm);
 	setup_vma_to_mm(new, mm);
-	mas_set_range(&mas, vma->vm_start, vma->vm_end - 1);
-	mas_store(&mas, vma);
-	vma_mas_store(new, &mas);
+	vma_iter_store(vmi, new);
 	mm->map_count++;
 	return 0;
 
-err_mas_preallocate:
+err_vmi_preallocate:
 	vm_area_free(new);
 err_vma_dup:
 	kmem_cache_free(vm_region_jar, region);
@@ -1413,7 +1375,7 @@ err_vma_dup:
  * shrink a VMA by removing the specified chunk from either the beginning or
  * the end
  */
-static int shrink_vma(struct mm_struct *mm,
+static int vmi_shrink_vma(struct vma_iterator *vmi,
 		      struct vm_area_struct *vma,
 		      unsigned long from, unsigned long to)
 {
@@ -1421,14 +1383,19 @@ static int shrink_vma(struct mm_struct *mm,
 
 	/* adjust the VMA's pointers, which may reposition it in the MM's tree
 	 * and list */
-	if (delete_vma_from_mm(vma))
+	if (vma_iter_prealloc(vmi)) {
+		pr_warn("Allocation of vma tree for process %d failed\n",
+		       current->pid);
 		return -ENOMEM;
-	if (from > vma->vm_start)
+	}
+
+	if (from > vma->vm_start) {
+		vma_iter_clear(vmi, from, vma->vm_end);
 		vma->vm_end = from;
-	else
+	} else {
+		vma_iter_clear(vmi, vma->vm_start, to);
 		vma->vm_start = to;
-	if (add_vma_to_mm(mm, vma))
-		return -ENOMEM;
+	}
 
 	/* cut the backing region down to size */
 	region = vma->vm_region;
@@ -1456,7 +1423,7 @@ static int shrink_vma(struct mm_struct *mm,
  */
 int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list_head *uf)
 {
-	MA_STATE(mas, &mm->mm_mt, start, start);
+	VMA_ITERATOR(vmi, mm, start);
 	struct vm_area_struct *vma;
 	unsigned long end;
 	int ret = 0;
@@ -1468,7 +1435,7 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list
 	end = start + len;
 
 	/* find the first potentially overlapping VMA */
-	vma = mas_find(&mas, end - 1);
+	vma = vma_find(&vmi, end);
 	if (!vma) {
 		static int limit;
 		if (limit < 5) {
@@ -1487,7 +1454,7 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list
 				return -EINVAL;
 			if (end == vma->vm_end)
 				goto erase_whole_vma;
-			vma = mas_next(&mas, end - 1);
+			vma = vma_find(&vmi, end);
 		} while (vma);
 		return -EINVAL;
 	} else {
@@ -1501,11 +1468,11 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list
 		if (end != vma->vm_end && offset_in_page(end))
 			return -EINVAL;
 		if (start != vma->vm_start && end != vma->vm_end) {
-			ret = split_vma(mm, vma, start, 1);
+			ret = split_vma(&vmi, vma, start, 1);
 			if (ret < 0)
 				return ret;
 		}
-		return shrink_vma(mm, vma, start, end);
+		return vmi_shrink_vma(&vmi, vma, start, end);
 	}
 
 erase_whole_vma:
@@ -1600,7 +1567,7 @@ static unsigned long do_mremap(unsigned long addr,
 	if (vma->vm_end != vma->vm_start + old_len)
 		return (unsigned long) -EFAULT;
 
-	if (vma->vm_flags & VM_MAYSHARE)
+	if (is_nommu_shared_mapping(vma->vm_flags))
 		return (unsigned long) -EPERM;
 
 	if (new_len > vma->vm_region->vm_end - vma->vm_region->vm_start)
@@ -1635,7 +1602,7 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
 	if (addr != (pfn << PAGE_SHIFT))
 		return -EINVAL;
 
-	vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
+	vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP);
 	return 0;
 }
 EXPORT_SYMBOL(remap_pfn_range);