1 files changed, 141 insertions, 119 deletions

diff --git a/mm/nommu.c b/mm/nommu.c
index e819cbc21b39..214c70e1d059 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -19,7 +19,6 @@
 #include <linux/export.h>
 #include <linux/mm.h>
 #include <linux/sched/mm.h>
-#include <linux/vmacache.h>
 #include <linux/mman.h>
 #include <linux/swap.h>
 #include <linux/file.h>
@@ -545,26 +544,27 @@ static void put_nommu_region(struct vm_region *region)
 	__put_nommu_region(region);
 }
 
-/*
- * 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 void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
+void vma_mas_store(struct vm_area_struct *vma, struct ma_state *mas)
 {
-	struct vm_area_struct *pvma, *prev;
-	struct address_space *mapping;
-	struct rb_node **p, *parent, *rb_prev;
+	mas_set_range(mas, vma->vm_start, vma->vm_end - 1);
+	mas_store_prealloc(mas, vma);
+}
 
-	BUG_ON(!vma->vm_region);
+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)
+{
 	mm->map_count++;
 	vma->vm_mm = mm;
 
 	/* add the VMA to the mapping */
 	if (vma->vm_file) {
-		mapping = vma->vm_file->f_mapping;
+		struct address_space *mapping = vma->vm_file->f_mapping;
 
 		i_mmap_lock_write(mapping);
 		flush_dcache_mmap_lock(mapping);
@@ -572,67 +572,51 @@ static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
 		flush_dcache_mmap_unlock(mapping);
 		i_mmap_unlock_write(mapping);
 	}
+}
 
-	/* add the VMA to the tree */
-	parent = rb_prev = NULL;
-	p = &mm->mm_rb.rb_node;
-	while (*p) {
-		parent = *p;
-		pvma = rb_entry(parent, struct vm_area_struct, vm_rb);
-
-		/* sort by: start addr, end addr, VMA struct addr in that order
-		 * (the latter is necessary as we may get identical VMAs) */
-		if (vma->vm_start < pvma->vm_start)
-			p = &(*p)->rb_left;
-		else if (vma->vm_start > pvma->vm_start) {
-			rb_prev = parent;
-			p = &(*p)->rb_right;
-		} else if (vma->vm_end < pvma->vm_end)
-			p = &(*p)->rb_left;
-		else if (vma->vm_end > pvma->vm_end) {
-			rb_prev = parent;
-			p = &(*p)->rb_right;
-		} else if (vma < pvma)
-			p = &(*p)->rb_left;
-		else if (vma > pvma) {
-			rb_prev = parent;
-			p = &(*p)->rb_right;
-		} else
-			BUG();
-	}
-
-	rb_link_node(&vma->vm_rb, parent, p);
-	rb_insert_color(&vma->vm_rb, &mm->mm_rb);
+/*
+ * 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);
 
-	/* add VMA to the VMA list also */
-	prev = NULL;
-	if (rb_prev)
-		prev = rb_entry(rb_prev, struct vm_area_struct, vm_rb);
+	setup_vma_to_mm(vma, mm);
 
-	__vma_link_list(mm, vma, prev);
+	/* add the VMA to the tree */
+	vma_mas_store(vma, mas);
 }
 
 /*
- * delete a VMA from its owning mm_struct and address space
+ * 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 void delete_vma_from_mm(struct vm_area_struct *vma)
-{
-	int i;
-	struct address_space *mapping;
-	struct mm_struct *mm = vma->vm_mm;
-	struct task_struct *curr = current;
-
-	mm->map_count--;
-	for (i = 0; i < VMACACHE_SIZE; i++) {
-		/* if the vma is cached, invalidate the entire cache */
-		if (curr->vmacache.vmas[i] == vma) {
-			vmacache_invalidate(mm);
-			break;
-		}
+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--;
 	/* remove the VMA from the mapping */
 	if (vma->vm_file) {
+		struct address_space *mapping;
 		mapping = vma->vm_file->f_mapping;
 
 		i_mmap_lock_write(mapping);
@@ -641,11 +625,24 @@ static void delete_vma_from_mm(struct vm_area_struct *vma)
 		flush_dcache_mmap_unlock(mapping);
 		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);
 
-	/* remove from the MM's tree and list */
-	rb_erase(&vma->vm_rb, &mm->mm_rb);
+	if (mas_preallocate(&mas, vma, GFP_KERNEL)) {
+		pr_warn("Allocation of vma tree for process %d failed\n",
+		       current->pid);
+		return -ENOMEM;
+	}
+	cleanup_vma_from_mm(vma);
 
-	__vma_unlink_list(mm, vma);
+	/* remove from the MM's tree and list */
+	vma_mas_remove(vma, &mas);
+	return 0;
 }
 
 /*
@@ -661,31 +658,26 @@ static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma)
 	vm_area_free(vma);
 }
 
+struct vm_area_struct *find_vma_intersection(struct mm_struct *mm,
+					     unsigned long start_addr,
+					     unsigned long end_addr)
+{
+	unsigned long index = start_addr;
+
+	mmap_assert_locked(mm);
+	return mt_find(&mm->mm_mt, &index, end_addr - 1);
+}
+EXPORT_SYMBOL(find_vma_intersection);
+
 /*
  * look up the first VMA in which addr resides, NULL if none
  * - should be called with mm->mmap_lock at least held readlocked
  */
 struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
 {
-	struct vm_area_struct *vma;
+	MA_STATE(mas, &mm->mm_mt, addr, addr);
 
-	/* check the cache first */
-	vma = vmacache_find(mm, addr);
-	if (likely(vma))
-		return vma;
-
-	/* trawl the list (there may be multiple mappings in which addr
-	 * resides) */
-	for (vma = mm->mmap; vma; vma = vma->vm_next) {
-		if (vma->vm_start > addr)
-			return NULL;
-		if (vma->vm_end > addr) {
-			vmacache_update(addr, vma);
-			return vma;
-		}
-	}
-
-	return NULL;
+	return mas_walk(&mas);
 }
 EXPORT_SYMBOL(find_vma);
 
@@ -717,26 +709,17 @@ 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);
 
-	/* check the cache first */
-	vma = vmacache_find_exact(mm, addr, end);
-	if (vma)
-		return vma;
-
-	/* trawl the list (there may be multiple mappings in which addr
-	 * resides) */
-	for (vma = mm->mmap; vma; vma = vma->vm_next) {
-		if (vma->vm_start < addr)
-			continue;
-		if (vma->vm_start > addr)
-			return NULL;
-		if (vma->vm_end == end) {
-			vmacache_update(addr, vma);
-			return vma;
-		}
-	}
+	vma = mas_walk(&mas);
+	if (!vma)
+		return NULL;
+	if (vma->vm_start != addr)
+		return NULL;
+	if (vma->vm_end != end)
+		return NULL;
 
-	return NULL;
+	return vma;
 }
 
 /*
@@ -1069,6 +1052,7 @@ 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);
 
 	*populate = 0;
 
@@ -1087,6 +1071,7 @@ unsigned long do_mmap(struct file *file,
 	 * now know into VMA flags */
 	vm_flags = determine_vm_flags(file, prot, flags, capabilities);
 
+
 	/* we're going to need to record the mapping */
 	region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL);
 	if (!region)
@@ -1096,6 +1081,9 @@ unsigned long do_mmap(struct file *file,
 	if (!vma)
 		goto error_getting_vma;
 
+	if (mas_preallocate(&mas, vma, GFP_KERNEL))
+		goto error_maple_preallocate;
+
 	region->vm_usage = 1;
 	region->vm_flags = vm_flags;
 	region->vm_pgoff = pgoff;
@@ -1236,7 +1224,7 @@ unsigned long do_mmap(struct file *file,
 	current->mm->total_vm += len >> PAGE_SHIFT;
 
 share:
-	add_vma_to_mm(current->mm, vma);
+	mas_add_vma_to_mm(&mas, current->mm, vma);
 
 	/* we flush the region from the icache only when the first executable
 	 * mapping of it is made  */
@@ -1262,6 +1250,7 @@ error:
 
 sharing_violation:
 	up_write(&nommu_region_sem);
+	mas_destroy(&mas);
 	pr_warn("Attempt to share mismatched mappings\n");
 	ret = -EINVAL;
 	goto error;
@@ -1278,6 +1267,14 @@ error_getting_region:
 			len, current->pid);
 	show_free_areas(0, NULL);
 	return -ENOMEM;
+
+error_maple_preallocate:
+	kmem_cache_free(vm_region_jar, region);
+	vm_area_free(vma);
+	pr_warn("Allocation of vma tree for process %d failed\n", current->pid);
+	show_free_areas(0, NULL);
+	return -ENOMEM;
+
 }
 
 unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len,
@@ -1343,6 +1340,7 @@ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
 	struct vm_area_struct *new;
 	struct vm_region *region;
 	unsigned long npages;
+	MA_STATE(mas, &mm->mm_mt, vma->vm_start, vma->vm_end);
 
 	/* we're only permitted to split anonymous regions (these should have
 	 * only a single usage on the region) */
@@ -1357,9 +1355,13 @@ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
 		return -ENOMEM;
 
 	new = vm_area_dup(vma);
-	if (!new) {
-		kmem_cache_free(vm_region_jar, region);
-		return -ENOMEM;
+	if (!new)
+		goto err_vma_dup;
+
+	if (mas_preallocate(&mas, vma, GFP_KERNEL)) {
+		pr_warn("Allocation of vma tree for process %d failed\n",
+			current->pid);
+		goto err_mas_preallocate;
 	}
 
 	/* most fields are the same, copy all, and then fixup */
@@ -1378,7 +1380,6 @@ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
 	if (new->vm_ops && new->vm_ops->open)
 		new->vm_ops->open(new);
 
-	delete_vma_from_mm(vma);
 	down_write(&nommu_region_sem);
 	delete_nommu_region(vma->vm_region);
 	if (new_below) {
@@ -1391,9 +1392,19 @@ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
 	add_nommu_region(vma->vm_region);
 	add_nommu_region(new->vm_region);
 	up_write(&nommu_region_sem);
-	add_vma_to_mm(mm, vma);
-	add_vma_to_mm(mm, new);
+
+	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);
 	return 0;
+
+err_mas_preallocate:
+	vm_area_free(new);
+err_vma_dup:
+	kmem_cache_free(vm_region_jar, region);
+	return -ENOMEM;
 }
 
 /*
@@ -1408,12 +1419,14 @@ static int shrink_vma(struct mm_struct *mm,
 
 	/* adjust the VMA's pointers, which may reposition it in the MM's tree
 	 * and list */
-	delete_vma_from_mm(vma);
+	if (delete_vma_from_mm(vma))
+		return -ENOMEM;
 	if (from > vma->vm_start)
 		vma->vm_end = from;
 	else
 		vma->vm_start = to;
-	add_vma_to_mm(mm, vma);
+	if (add_vma_to_mm(mm, vma))
+		return -ENOMEM;
 
 	/* cut the backing region down to size */
 	region = vma->vm_region;
@@ -1441,9 +1454,10 @@ 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);
 	struct vm_area_struct *vma;
 	unsigned long end;
-	int ret;
+	int ret = 0;
 
 	len = PAGE_ALIGN(len);
 	if (len == 0)
@@ -1452,7 +1466,7 @@ 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 = find_vma(mm, start);
+	vma = mas_find(&mas, end - 1);
 	if (!vma) {
 		static int limit;
 		if (limit < 5) {
@@ -1471,7 +1485,7 @@ 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 = vma->vm_next;
+			vma = mas_next(&mas, end - 1);
 		} while (vma);
 		return -EINVAL;
 	} else {
@@ -1493,9 +1507,10 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list
 	}
 
 erase_whole_vma:
-	delete_vma_from_mm(vma);
+	if (delete_vma_from_mm(vma))
+		ret = -ENOMEM;
 	delete_vma(mm, vma);
-	return 0;
+	return ret;
 }
 
 int vm_munmap(unsigned long addr, size_t len)
@@ -1520,6 +1535,7 @@ SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len)
  */
 void exit_mmap(struct mm_struct *mm)
 {
+	VMA_ITERATOR(vmi, mm, 0);
 	struct vm_area_struct *vma;
 
 	if (!mm)
@@ -1527,12 +1543,18 @@ void exit_mmap(struct mm_struct *mm)
 
 	mm->total_vm = 0;
 
-	while ((vma = mm->mmap)) {
-		mm->mmap = vma->vm_next;
-		delete_vma_from_mm(vma);
+	/*
+	 * Lock the mm to avoid assert complaining even though this is the only
+	 * user of the mm
+	 */
+	mmap_write_lock(mm);
+	for_each_vma(vmi, vma) {
+		cleanup_vma_from_mm(vma);
 		delete_vma(mm, vma);
 		cond_resched();
 	}
+	__mt_destroy(&mm->mm_mt);
+	mmap_write_unlock(mm);
 }
 
 int vm_brk(unsigned long addr, unsigned long len)