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, 266 insertions, 195 deletions

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 61f5bec0f2b6..ef910bf349e1 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -89,17 +89,6 @@ struct vfree_deferred {
 };
 static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);
 
-static void __vunmap(const void *, int);
-
-static void free_work(struct work_struct *w)
-{
-	struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
-	struct llist_node *t, *llnode;
-
-	llist_for_each_safe(llnode, t, llist_del_all(&p->list))
-		__vunmap((void *)llnode, 1);
-}
-
 /*** Page table manipulation functions ***/
 static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 			phys_addr_t phys_addr, pgprot_t prot,
@@ -1590,7 +1579,8 @@ preload_this_cpu_lock(spinlock_t *lock, gfp_t gfp_mask, int node)
 static struct vmap_area *alloc_vmap_area(unsigned long size,
 				unsigned long align,
 				unsigned long vstart, unsigned long vend,
-				int node, gfp_t gfp_mask)
+				int node, gfp_t gfp_mask,
+				unsigned long va_flags)
 {
 	struct vmap_area *va;
 	unsigned long freed;
@@ -1598,9 +1588,8 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
 	int purged = 0;
 	int ret;
 
-	BUG_ON(!size);
-	BUG_ON(offset_in_page(size));
-	BUG_ON(!is_power_of_2(align));
+	if (unlikely(!size || offset_in_page(size) || !is_power_of_2(align)))
+		return ERR_PTR(-EINVAL);
 
 	if (unlikely(!vmap_initialized))
 		return ERR_PTR(-EBUSY);
@@ -1636,6 +1625,7 @@ retry:
 	va->va_start = addr;
 	va->va_end = addr + size;
 	va->vm = NULL;
+	va->flags = va_flags;
 
 	spin_lock(&vmap_area_lock);
 	insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
@@ -1816,9 +1806,9 @@ static void drain_vmap_area_work(struct work_struct *work)
 }
 
 /*
- * Free a vmap area, caller ensuring that the area has been unmapped
- * and flush_cache_vunmap had been called for the correct range
- * previously.
+ * Free a vmap area, caller ensuring that the area has been unmapped,
+ * unlinked and flush_cache_vunmap had been called for the correct
+ * range previously.
  */
 static void free_vmap_area_noflush(struct vmap_area *va)
 {
@@ -1826,9 +1816,8 @@ static void free_vmap_area_noflush(struct vmap_area *va)
 	unsigned long va_start = va->va_start;
 	unsigned long nr_lazy;
 
-	spin_lock(&vmap_area_lock);
-	unlink_va(va, &vmap_area_root);
-	spin_unlock(&vmap_area_lock);
+	if (WARN_ON_ONCE(!list_empty(&va->list)))
+		return;
 
 	nr_lazy = atomic_long_add_return((va->va_end - va->va_start) >>
 				PAGE_SHIFT, &vmap_lazy_nr);
@@ -1872,6 +1861,19 @@ struct vmap_area *find_vmap_area(unsigned long addr)
 	return va;
 }
 
+static struct vmap_area *find_unlink_vmap_area(unsigned long addr)
+{
+	struct vmap_area *va;
+
+	spin_lock(&vmap_area_lock);
+	va = __find_vmap_area(addr, &vmap_area_root);
+	if (va)
+		unlink_va(va, &vmap_area_root);
+	spin_unlock(&vmap_area_lock);
+
+	return va;
+}
+
 /*** Per cpu kva allocator ***/
 
 /*
@@ -1902,6 +1904,10 @@ struct vmap_area *find_vmap_area(unsigned long addr)
 
 #define VMAP_BLOCK_SIZE		(VMAP_BBMAP_BITS * PAGE_SIZE)
 
+#define VMAP_RAM		0x1 /* indicates vm_map_ram area*/
+#define VMAP_BLOCK		0x2 /* mark out the vmap_block sub-type*/
+#define VMAP_FLAGS_MASK		0x3
+
 struct vmap_block_queue {
 	spinlock_t lock;
 	struct list_head free;
@@ -1911,6 +1917,7 @@ struct vmap_block {
 	spinlock_t lock;
 	struct vmap_area *va;
 	unsigned long free, dirty;
+	DECLARE_BITMAP(used_map, VMAP_BBMAP_BITS);
 	unsigned long dirty_min, dirty_max; /*< dirty range */
 	struct list_head free_list;
 	struct rcu_head rcu_head;
@@ -1976,7 +1983,8 @@ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
 
 	va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
 					VMALLOC_START, VMALLOC_END,
-					node, gfp_mask);
+					node, gfp_mask,
+					VMAP_RAM|VMAP_BLOCK);
 	if (IS_ERR(va)) {
 		kfree(vb);
 		return ERR_CAST(va);
@@ -1987,10 +1995,12 @@ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
 	vb->va = va;
 	/* At least something should be left free */
 	BUG_ON(VMAP_BBMAP_BITS <= (1UL << order));
+	bitmap_zero(vb->used_map, VMAP_BBMAP_BITS);
 	vb->free = VMAP_BBMAP_BITS - (1UL << order);
 	vb->dirty = 0;
 	vb->dirty_min = VMAP_BBMAP_BITS;
 	vb->dirty_max = 0;
+	bitmap_set(vb->used_map, 0, (1UL << order));
 	INIT_LIST_HEAD(&vb->free_list);
 
 	vb_idx = addr_to_vb_idx(va->va_start);
@@ -2016,6 +2026,10 @@ static void free_vmap_block(struct vmap_block *vb)
 	tmp = xa_erase(&vmap_blocks, addr_to_vb_idx(vb->va->va_start));
 	BUG_ON(tmp != vb);
 
+	spin_lock(&vmap_area_lock);
+	unlink_va(vb->va, &vmap_area_root);
+	spin_unlock(&vmap_area_lock);
+
 	free_vmap_area_noflush(vb->va);
 	kfree_rcu(vb, rcu_head);
 }
@@ -2096,6 +2110,7 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
 		pages_off = VMAP_BBMAP_BITS - vb->free;
 		vaddr = vmap_block_vaddr(vb->va->va_start, pages_off);
 		vb->free -= 1UL << order;
+		bitmap_set(vb->used_map, pages_off, (1UL << order));
 		if (vb->free == 0) {
 			spin_lock(&vbq->lock);
 			list_del_rcu(&vb->free_list);
@@ -2129,6 +2144,9 @@ static void vb_free(unsigned long addr, unsigned long size)
 	order = get_order(size);
 	offset = (addr & (VMAP_BLOCK_SIZE - 1)) >> PAGE_SHIFT;
 	vb = xa_load(&vmap_blocks, addr_to_vb_idx(addr));
+	spin_lock(&vb->lock);
+	bitmap_clear(vb->used_map, offset, (1UL << order));
+	spin_unlock(&vb->lock);
 
 	vunmap_range_noflush(addr, addr + size);
 
@@ -2237,8 +2255,10 @@ void vm_unmap_ram(const void *mem, unsigned int count)
 		return;
 	}
 
-	va = find_vmap_area(addr);
-	BUG_ON(!va);
+	va = find_unlink_vmap_area(addr);
+	if (WARN_ON_ONCE(!va))
+		return;
+
 	debug_check_no_locks_freed((void *)va->va_start,
 				    (va->va_end - va->va_start));
 	free_unmap_vmap_area(va);
@@ -2273,7 +2293,8 @@ void *vm_map_ram(struct page **pages, unsigned int count, int node)
 	} else {
 		struct vmap_area *va;
 		va = alloc_vmap_area(size, PAGE_SIZE,
-				VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
+				VMALLOC_START, VMALLOC_END,
+				node, GFP_KERNEL, VMAP_RAM);
 		if (IS_ERR(va))
 			return NULL;
 
@@ -2417,48 +2438,6 @@ static void vmap_init_free_space(void)
 	}
 }
 
-void __init vmalloc_init(void)
-{
-	struct vmap_area *va;
-	struct vm_struct *tmp;
-	int i;
-
-	/*
-	 * Create the cache for vmap_area objects.
-	 */
-	vmap_area_cachep = KMEM_CACHE(vmap_area, SLAB_PANIC);
-
-	for_each_possible_cpu(i) {
-		struct vmap_block_queue *vbq;
-		struct vfree_deferred *p;
-
-		vbq = &per_cpu(vmap_block_queue, i);
-		spin_lock_init(&vbq->lock);
-		INIT_LIST_HEAD(&vbq->free);
-		p = &per_cpu(vfree_deferred, i);
-		init_llist_head(&p->list);
-		INIT_WORK(&p->wq, free_work);
-	}
-
-	/* Import existing vmlist entries. */
-	for (tmp = vmlist; tmp; tmp = tmp->next) {
-		va = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
-		if (WARN_ON_ONCE(!va))
-			continue;
-
-		va->va_start = (unsigned long)tmp->addr;
-		va->va_end = va->va_start + tmp->size;
-		va->vm = tmp;
-		insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
-	}
-
-	/*
-	 * Now we can initialize a free vmap space.
-	 */
-	vmap_init_free_space();
-	vmap_initialized = true;
-}
-
 static inline void setup_vmalloc_vm_locked(struct vm_struct *vm,
 	struct vmap_area *va, unsigned long flags, const void *caller)
 {
@@ -2513,7 +2492,7 @@ static struct vm_struct *__get_vm_area_node(unsigned long size,
 	if (!(flags & VM_NO_GUARD))
 		size += PAGE_SIZE;
 
-	va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
+	va = alloc_vmap_area(size, align, start, end, node, gfp_mask, 0);
 	if (IS_ERR(va)) {
 		kfree(area);
 		return NULL;
@@ -2605,25 +2584,26 @@ struct vm_struct *find_vm_area(const void *addr)
 struct vm_struct *remove_vm_area(const void *addr)
 {
 	struct vmap_area *va;
+	struct vm_struct *vm;
 
 	might_sleep();
 
-	spin_lock(&vmap_area_lock);
-	va = __find_vmap_area((unsigned long)addr, &vmap_area_root);
-	if (va && va->vm) {
-		struct vm_struct *vm = va->vm;
-
-		va->vm = NULL;
-		spin_unlock(&vmap_area_lock);
+	if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
+			addr))
+		return NULL;
 
-		kasan_free_module_shadow(vm);
-		free_unmap_vmap_area(va);
+	va = find_unlink_vmap_area((unsigned long)addr);
+	if (!va || !va->vm)
+		return NULL;
+	vm = va->vm;
 
-		return vm;
-	}
+	debug_check_no_locks_freed(vm->addr, get_vm_area_size(vm));
+	debug_check_no_obj_freed(vm->addr, get_vm_area_size(vm));
+	kasan_free_module_shadow(vm);
+	kasan_poison_vmalloc(vm->addr, get_vm_area_size(vm));
 
-	spin_unlock(&vmap_area_lock);
-	return NULL;
+	free_unmap_vmap_area(va);
+	return vm;
 }
 
 static inline void set_area_direct_map(const struct vm_struct *area,
@@ -2637,37 +2617,23 @@ static inline void set_area_direct_map(const struct vm_struct *area,
 			set_direct_map(area->pages[i]);
 }
 
-/* Handle removing and resetting vm mappings related to the vm_struct. */
-static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages)
+/*
+ * Flush the vm mapping and reset the direct map.
+ */
+static void vm_reset_perms(struct vm_struct *area)
 {
 	unsigned long start = ULONG_MAX, end = 0;
 	unsigned int page_order = vm_area_page_order(area);
-	int flush_reset = area->flags & VM_FLUSH_RESET_PERMS;
 	int flush_dmap = 0;
 	int i;
 
-	remove_vm_area(area->addr);
-
-	/* If this is not VM_FLUSH_RESET_PERMS memory, no need for the below. */
-	if (!flush_reset)
-		return;
-
 	/*
-	 * If not deallocating pages, just do the flush of the VM area and
-	 * return.
-	 */
-	if (!deallocate_pages) {
-		vm_unmap_aliases();
-		return;
-	}
-
-	/*
-	 * If execution gets here, flush the vm mapping and reset the direct
-	 * map. Find the start and end range of the direct mappings to make sure
+	 * Find the start and end range of the direct mappings to make sure that
 	 * the vm_unmap_aliases() flush includes the direct map.
 	 */
 	for (i = 0; i < area->nr_pages; i += 1U << page_order) {
 		unsigned long addr = (unsigned long)page_address(area->pages[i]);
+
 		if (addr) {
 			unsigned long page_size;
 
@@ -2688,66 +2654,13 @@ static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages)
 	set_area_direct_map(area, set_direct_map_default_noflush);
 }
 
-static void __vunmap(const void *addr, int deallocate_pages)
+static void delayed_vfree_work(struct work_struct *w)
 {
-	struct vm_struct *area;
-
-	if (!addr)
-		return;
-
-	if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
-			addr))
-		return;
-
-	area = find_vm_area(addr);
-	if (unlikely(!area)) {
-		WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
-				addr);
-		return;
-	}
-
-	debug_check_no_locks_freed(area->addr, get_vm_area_size(area));
-	debug_check_no_obj_freed(area->addr, get_vm_area_size(area));
-
-	kasan_poison_vmalloc(area->addr, get_vm_area_size(area));
-
-	vm_remove_mappings(area, deallocate_pages);
-
-	if (deallocate_pages) {
-		int i;
-
-		for (i = 0; i < area->nr_pages; i++) {
-			struct page *page = area->pages[i];
-
-			BUG_ON(!page);
-			mod_memcg_page_state(page, MEMCG_VMALLOC, -1);
-			/*
-			 * High-order allocs for huge vmallocs are split, so
-			 * can be freed as an array of order-0 allocations
-			 */
-			__free_pages(page, 0);
-			cond_resched();
-		}
-		atomic_long_sub(area->nr_pages, &nr_vmalloc_pages);
-
-		kvfree(area->pages);
-	}
-
-	kfree(area);
-}
-
-static inline void __vfree_deferred(const void *addr)
-{
-	/*
-	 * Use raw_cpu_ptr() because this can be called from preemptible
-	 * context. Preemption is absolutely fine here, because the llist_add()
-	 * implementation is lockless, so it works even if we are adding to
-	 * another cpu's list. schedule_work() should be fine with this too.
-	 */
-	struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred);
+	struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
+	struct llist_node *t, *llnode;
 
-	if (llist_add((struct llist_node *)addr, &p->list))
-		schedule_work(&p->wq);
+	llist_for_each_safe(llnode, t, llist_del_all(&p->list))
+		vfree(llnode);
 }
 
 /**
@@ -2759,21 +2672,19 @@ static inline void __vfree_deferred(const void *addr)
  */
 void vfree_atomic(const void *addr)
 {
-	BUG_ON(in_nmi());
+	struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred);
 
+	BUG_ON(in_nmi());
 	kmemleak_free(addr);
 
-	if (!addr)
-		return;
-	__vfree_deferred(addr);
-}
-
-static void __vfree(const void *addr)
-{
-	if (unlikely(in_interrupt()))
-		__vfree_deferred(addr);
-	else
-		__vunmap(addr, 1);
+	/*
+	 * Use raw_cpu_ptr() because this can be called from preemptible
+	 * context. Preemption is absolutely fine here, because the llist_add()
+	 * implementation is lockless, so it works even if we are adding to
+	 * another cpu's list. schedule_work() should be fine with this too.
+	 */
+	if (addr && llist_add((struct llist_node *)addr, &p->list))
+		schedule_work(&p->wq);
 }
 
 /**
@@ -2795,16 +2706,45 @@ static void __vfree(const void *addr)
  */
 void vfree(const void *addr)
 {
-	BUG_ON(in_nmi());
+	struct vm_struct *vm;
+	int i;
 
-	kmemleak_free(addr);
+	if (unlikely(in_interrupt())) {
+		vfree_atomic(addr);
+		return;
+	}
 
-	might_sleep_if(!in_interrupt());
+	BUG_ON(in_nmi());
+	kmemleak_free(addr);
+	might_sleep();
 
 	if (!addr)
 		return;
 
-	__vfree(addr);
+	vm = remove_vm_area(addr);
+	if (unlikely(!vm)) {
+		WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
+				addr);
+		return;
+	}
+
+	if (unlikely(vm->flags & VM_FLUSH_RESET_PERMS))
+		vm_reset_perms(vm);
+	for (i = 0; i < vm->nr_pages; i++) {
+		struct page *page = vm->pages[i];
+
+		BUG_ON(!page);
+		mod_memcg_page_state(page, MEMCG_VMALLOC, -1);
+		/*
+		 * High-order allocs for huge vmallocs are split, so
+		 * can be freed as an array of order-0 allocations
+		 */
+		__free_pages(page, 0);
+		cond_resched();
+	}
+	atomic_long_sub(vm->nr_pages, &nr_vmalloc_pages);
+	kvfree(vm->pages);
+	kfree(vm);
 }
 EXPORT_SYMBOL(vfree);
 
@@ -2819,10 +2759,20 @@ EXPORT_SYMBOL(vfree);
  */
 void vunmap(const void *addr)
 {
+	struct vm_struct *vm;
+
 	BUG_ON(in_interrupt());
 	might_sleep();
-	if (addr)
-		__vunmap(addr, 0);
+
+	if (!addr)
+		return;
+	vm = remove_vm_area(addr);
+	if (unlikely(!vm)) {
+		WARN(1, KERN_ERR "Trying to vunmap() nonexistent vm area (%p)\n",
+				addr);
+		return;
+	}
+	kfree(vm);
 }
 EXPORT_SYMBOL(vunmap);
 
@@ -2850,6 +2800,9 @@ void *vmap(struct page **pages, unsigned int count,
 
 	might_sleep();
 
+	if (WARN_ON_ONCE(flags & VM_FLUSH_RESET_PERMS))
+		return NULL;
+
 	/*
 	 * Your top guard is someone else's bottom guard. Not having a top
 	 * guard compromises someone else's mappings too.
@@ -3032,7 +2985,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
 	int ret;
 
 	array_size = (unsigned long)nr_small_pages * sizeof(struct page *);
-	gfp_mask |= __GFP_NOWARN;
+
 	if (!(gfp_mask & (GFP_DMA | GFP_DMA32)))
 		gfp_mask |= __GFP_HIGHMEM;
 
@@ -3068,7 +3021,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
 
 	/*
 	 * If not enough pages were obtained to accomplish an
-	 * allocation request, free them via __vfree() if any.
+	 * allocation request, free them via vfree() if any.
 	 */
 	if (area->nr_pages != nr_small_pages) {
 		warn_alloc(gfp_mask, NULL,
@@ -3108,7 +3061,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
 	return area->addr;
 
 fail:
-	__vfree(area->addr);
+	vfree(area->addr);
 	return NULL;
 }
 
@@ -3511,6 +3464,68 @@ static int aligned_vread(char *buf, char *addr, unsigned long count)
 	return copied;
 }
 
+static void vmap_ram_vread(char *buf, char *addr, int count, unsigned long flags)
+{
+	char *start;
+	struct vmap_block *vb;
+	unsigned long offset;
+	unsigned int rs, re, n;
+
+	/*
+	 * If it's area created by vm_map_ram() interface directly, but
+	 * not further subdividing and delegating management to vmap_block,
+	 * handle it here.
+	 */
+	if (!(flags & VMAP_BLOCK)) {
+		aligned_vread(buf, addr, count);
+		return;
+	}
+
+	/*
+	 * Area is split into regions and tracked with vmap_block, read out
+	 * each region and zero fill the hole between regions.
+	 */
+	vb = xa_load(&vmap_blocks, addr_to_vb_idx((unsigned long)addr));
+	if (!vb)
+		goto finished;
+
+	spin_lock(&vb->lock);
+	if (bitmap_empty(vb->used_map, VMAP_BBMAP_BITS)) {
+		spin_unlock(&vb->lock);
+		goto finished;
+	}
+	for_each_set_bitrange(rs, re, vb->used_map, VMAP_BBMAP_BITS) {
+		if (!count)
+			break;
+		start = vmap_block_vaddr(vb->va->va_start, rs);
+		while (addr < start) {
+			if (count == 0)
+				goto unlock;
+			*buf = '\0';
+			buf++;
+			addr++;
+			count--;
+		}
+		/*it could start reading from the middle of used region*/
+		offset = offset_in_page(addr);
+		n = ((re - rs + 1) << PAGE_SHIFT) - offset;
+		if (n > count)
+			n = count;
+		aligned_vread(buf, start+offset, n);
+
+		buf += n;
+		addr += n;
+		count -= n;
+	}
+unlock:
+	spin_unlock(&vb->lock);
+
+finished:
+	/* zero-fill the left dirty or free regions */
+	if (count)
+		memset(buf, 0, count);
+}
+
 /**
  * vread() - read vmalloc area in a safe way.
  * @buf:     buffer for reading data
@@ -3541,7 +3556,7 @@ long vread(char *buf, char *addr, unsigned long count)
 	struct vm_struct *vm;
 	char *vaddr, *buf_start = buf;
 	unsigned long buflen = count;
-	unsigned long n;
+	unsigned long n, size, flags;
 
 	addr = kasan_reset_tag(addr);
 
@@ -3562,12 +3577,26 @@ long vread(char *buf, char *addr, unsigned long count)
 		if (!count)
 			break;
 
-		if (!va->vm)
+		vm = va->vm;
+		flags = va->flags & VMAP_FLAGS_MASK;
+		/*
+		 * VMAP_BLOCK indicates a sub-type of vm_map_ram area, need
+		 * be set together with VMAP_RAM.
+		 */
+		WARN_ON(flags == VMAP_BLOCK);
+
+		if (!vm && !flags)
 			continue;
 
-		vm = va->vm;
-		vaddr = (char *) vm->addr;
-		if (addr >= vaddr + get_vm_area_size(vm))
+		if (vm && (vm->flags & VM_UNINITIALIZED))
+			continue;
+		/* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
+		smp_rmb();
+
+		vaddr = (char *) va->va_start;
+		size = vm ? get_vm_area_size(vm) : va_size(va);
+
+		if (addr >= vaddr + size)
 			continue;
 		while (addr < vaddr) {
 			if (count == 0)
@@ -3577,10 +3606,13 @@ long vread(char *buf, char *addr, unsigned long count)
 			addr++;
 			count--;
 		}
-		n = vaddr + get_vm_area_size(vm) - addr;
+		n = vaddr + size - addr;
 		if (n > count)
 			n = count;
-		if (!(vm->flags & VM_IOREMAP))
+
+		if (flags & VMAP_RAM)
+			vmap_ram_vread(buf, addr, n, flags);
+		else if (!(vm->flags & VM_IOREMAP))
 			aligned_vread(buf, addr, n);
 		else /* IOREMAP area is treated as memory hole */
 			memset(buf, 0, n);
@@ -3658,7 +3690,7 @@ int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
 		size -= PAGE_SIZE;
 	} while (size > 0);
 
-	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
+	vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP);
 
 	return 0;
 }
@@ -4126,14 +4158,11 @@ static int s_show(struct seq_file *m, void *p)
 
 	va = list_entry(p, struct vmap_area, list);
 
-	/*
-	 * s_show can encounter race with remove_vm_area, !vm on behalf
-	 * of vmap area is being tear down or vm_map_ram allocation.
-	 */
 	if (!va->vm) {
-		seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
-			(void *)va->va_start, (void *)va->va_end,
-			va->va_end - va->va_start);
+		if (va->flags & VMAP_RAM)
+			seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
+				(void *)va->va_start, (void *)va->va_end,
+				va->va_end - va->va_start);
 
 		goto final;
 	}
@@ -4203,3 +4232,45 @@ static int __init proc_vmalloc_init(void)
 module_init(proc_vmalloc_init);
 
 #endif
+
+void __init vmalloc_init(void)
+{
+	struct vmap_area *va;
+	struct vm_struct *tmp;
+	int i;
+
+	/*
+	 * Create the cache for vmap_area objects.
+	 */
+	vmap_area_cachep = KMEM_CACHE(vmap_area, SLAB_PANIC);
+
+	for_each_possible_cpu(i) {
+		struct vmap_block_queue *vbq;
+		struct vfree_deferred *p;
+
+		vbq = &per_cpu(vmap_block_queue, i);
+		spin_lock_init(&vbq->lock);
+		INIT_LIST_HEAD(&vbq->free);
+		p = &per_cpu(vfree_deferred, i);
+		init_llist_head(&p->list);
+		INIT_WORK(&p->wq, delayed_vfree_work);
+	}
+
+	/* Import existing vmlist entries. */
+	for (tmp = vmlist; tmp; tmp = tmp->next) {
+		va = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
+		if (WARN_ON_ONCE(!va))
+			continue;
+
+		va->va_start = (unsigned long)tmp->addr;
+		va->va_end = va->va_start + tmp->size;
+		va->vm = tmp;
+		insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
+	}
+
+	/*
+	 * Now we can initialize a free vmap space.
+	 */
+	vmap_init_free_space();
+	vmap_initialized = true;
+}