7 files changed, 301 insertions, 182 deletions
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index ef353ca13c35..76052006bd87 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -1971,7 +1971,7 @@ static bool binder_validate_fixup(struct binder_proc *proc,
  * struct binder_task_work_cb - for deferred close
  *
  * @twork:                callback_head for task work
- * @fd:                   fd to close
+ * @file:                 file to close
  *
  * Structure to pass task work to be handled after
  * returning from binder_ioctl() via task_work_add().
@@ -3017,8 +3017,7 @@ static void binder_transaction(struct binder_proc *proc,
 	struct binder_context *context = proc->context;
 	int t_debug_id = atomic_inc_return(&binder_last_id);
 	ktime_t t_start_time = ktime_get();
-	char *secctx = NULL;
-	u32 secctx_sz = 0;
+	struct lsm_context lsmctx = { };
 	struct list_head sgc_head;
 	struct list_head pf_head;
 	const void __user *user_buffer = (const void __user *)
@@ -3297,8 +3296,8 @@ static void binder_transaction(struct binder_proc *proc,
 		size_t added_size;
 
 		security_cred_getsecid(proc->cred, &secid);
-		ret = security_secid_to_secctx(secid, &secctx, &secctx_sz);
-		if (ret) {
+		ret = security_secid_to_secctx(secid, &lsmctx);
+		if (ret < 0) {
 			binder_txn_error("%d:%d failed to get security context\n",
 				thread->pid, proc->pid);
 			return_error = BR_FAILED_REPLY;
@@ -3306,7 +3305,7 @@ static void binder_transaction(struct binder_proc *proc,
 			return_error_line = __LINE__;
 			goto err_get_secctx_failed;
 		}
-		added_size = ALIGN(secctx_sz, sizeof(u64));
+		added_size = ALIGN(lsmctx.len, sizeof(u64));
 		extra_buffers_size += added_size;
 		if (extra_buffers_size < added_size) {
 			binder_txn_error("%d:%d integer overflow of extra_buffers_size\n",
@@ -3340,23 +3339,23 @@ static void binder_transaction(struct binder_proc *proc,
 		t->buffer = NULL;
 		goto err_binder_alloc_buf_failed;
 	}
-	if (secctx) {
+	if (lsmctx.context) {
 		int err;
 		size_t buf_offset = ALIGN(tr->data_size, sizeof(void *)) +
 				    ALIGN(tr->offsets_size, sizeof(void *)) +
 				    ALIGN(extra_buffers_size, sizeof(void *)) -
-				    ALIGN(secctx_sz, sizeof(u64));
+				    ALIGN(lsmctx.len, sizeof(u64));
 
 		t->security_ctx = t->buffer->user_data + buf_offset;
 		err = binder_alloc_copy_to_buffer(&target_proc->alloc,
 						  t->buffer, buf_offset,
-						  secctx, secctx_sz);
+						  lsmctx.context, lsmctx.len);
 		if (err) {
 			t->security_ctx = 0;
 			WARN_ON(1);
 		}
-		security_release_secctx(secctx, secctx_sz);
-		secctx = NULL;
+		security_release_secctx(&lsmctx);
+		lsmctx.context = NULL;
 	}
 	t->buffer->debug_id = t->debug_id;
 	t->buffer->transaction = t;
@@ -3400,7 +3399,7 @@ static void binder_transaction(struct binder_proc *proc,
 	off_end_offset = off_start_offset + tr->offsets_size;
 	sg_buf_offset = ALIGN(off_end_offset, sizeof(void *));
 	sg_buf_end_offset = sg_buf_offset + extra_buffers_size -
-		ALIGN(secctx_sz, sizeof(u64));
+		ALIGN(lsmctx.len, sizeof(u64));
 	off_min = 0;
 	for (buffer_offset = off_start_offset; buffer_offset < off_end_offset;
 	     buffer_offset += sizeof(binder_size_t)) {
@@ -3779,8 +3778,8 @@ err_copy_data_failed:
 	binder_alloc_free_buf(&target_proc->alloc, t->buffer);
 err_binder_alloc_buf_failed:
 err_bad_extra_size:
-	if (secctx)
-		security_release_secctx(secctx, secctx_sz);
+	if (lsmctx.context)
+		security_release_secctx(&lsmctx);
 err_get_secctx_failed:
 	kfree(tcomplete);
 	binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
@@ -3801,13 +3800,13 @@ err_invalid_target_handle:
 	}
 
 	binder_debug(BINDER_DEBUG_FAILED_TRANSACTION,
-		     "%d:%d transaction %s to %d:%d failed %d/%d/%d, size %lld-%lld line %d\n",
+		     "%d:%d transaction %s to %d:%d failed %d/%d/%d, code %u size %lld-%lld line %d\n",
 		     proc->pid, thread->pid, reply ? "reply" :
 		     (tr->flags & TF_ONE_WAY ? "async" : "call"),
 		     target_proc ? target_proc->pid : 0,
 		     target_thread ? target_thread->pid : 0,
 		     t_debug_id, return_error, return_error_param,
-		     (u64)tr->data_size, (u64)tr->offsets_size,
+		     tr->code, (u64)tr->data_size, (u64)tr->offsets_size,
 		     return_error_line);
 
 	if (target_thread)
@@ -6374,7 +6373,7 @@ static void print_binder_transaction_ilocked(struct seq_file *m,
 		seq_printf(m, " node %d", buffer->target_node->debug_id);
 	seq_printf(m, " size %zd:%zd offset %lx\n",
 		   buffer->data_size, buffer->offsets_size,
-		   proc->alloc.buffer - buffer->user_data);
+		   proc->alloc.vm_start - buffer->user_data);
 }
 
 static void print_binder_work_ilocked(struct seq_file *m,
@@ -6928,6 +6927,11 @@ const struct binder_debugfs_entry binder_debugfs_entries[] = {
 	{} /* terminator */
 };
 
+void binder_add_device(struct binder_device *device)
+{
+	hlist_add_head(&device->hlist, &binder_devices);
+}
+
 static int __init init_binder_device(const char *name)
 {
 	int ret;
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index a738e7745865..fcfaf1b899c8 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -61,7 +61,7 @@ static size_t binder_alloc_buffer_size(struct binder_alloc *alloc,
 				       struct binder_buffer *buffer)
 {
 	if (list_is_last(&buffer->entry, &alloc->buffers))
-		return alloc->buffer + alloc->buffer_size - buffer->user_data;
+		return alloc->vm_start + alloc->buffer_size - buffer->user_data;
 	return binder_buffer_next(buffer)->user_data - buffer->user_data;
 }
 
@@ -169,32 +169,33 @@ struct binder_buffer *binder_alloc_prepare_to_free(struct binder_alloc *alloc,
 {
 	struct binder_buffer *buffer;
 
-	spin_lock(&alloc->lock);
+	mutex_lock(&alloc->mutex);
 	buffer = binder_alloc_prepare_to_free_locked(alloc, user_ptr);
-	spin_unlock(&alloc->lock);
+	mutex_unlock(&alloc->mutex);
 	return buffer;
 }
 
 static inline void
-binder_set_installed_page(struct binder_lru_page *lru_page,
+binder_set_installed_page(struct binder_alloc *alloc,
+			  unsigned long index,
 			  struct page *page)
 {
 	/* Pairs with acquire in binder_get_installed_page() */
-	smp_store_release(&lru_page->page_ptr, page);
+	smp_store_release(&alloc->pages[index], page);
 }
 
 static inline struct page *
-binder_get_installed_page(struct binder_lru_page *lru_page)
+binder_get_installed_page(struct binder_alloc *alloc, unsigned long index)
 {
 	/* Pairs with release in binder_set_installed_page() */
-	return smp_load_acquire(&lru_page->page_ptr);
+	return smp_load_acquire(&alloc->pages[index]);
 }
 
 static void binder_lru_freelist_add(struct binder_alloc *alloc,
 				    unsigned long start, unsigned long end)
 {
-	struct binder_lru_page *page;
 	unsigned long page_addr;
+	struct page *page;
 
 	trace_binder_update_page_range(alloc, false, start, end);
 
@@ -202,65 +203,159 @@ static void binder_lru_freelist_add(struct binder_alloc *alloc,
 		size_t index;
 		int ret;
 
-		index = (page_addr - alloc->buffer) / PAGE_SIZE;
-		page = &alloc->pages[index];
-
-		if (!binder_get_installed_page(page))
+		index = (page_addr - alloc->vm_start) / PAGE_SIZE;
+		page = binder_get_installed_page(alloc, index);
+		if (!page)
 			continue;
 
 		trace_binder_free_lru_start(alloc, index);
 
-		ret = list_lru_add_obj(&binder_freelist, &page->lru);
+		ret = list_lru_add(&binder_freelist,
+				   page_to_lru(page),
+				   page_to_nid(page),
+				   NULL);
 		WARN_ON(!ret);
 
 		trace_binder_free_lru_end(alloc, index);
 	}
 }
 
-static int binder_install_single_page(struct binder_alloc *alloc,
-				      struct binder_lru_page *lru_page,
-				      unsigned long addr)
+static inline
+void binder_alloc_set_mapped(struct binder_alloc *alloc, bool state)
 {
-	struct page *page;
-	int ret = 0;
+	/* pairs with smp_load_acquire in binder_alloc_is_mapped() */
+	smp_store_release(&alloc->mapped, state);
+}
 
-	if (!mmget_not_zero(alloc->mm))
-		return -ESRCH;
+static inline bool binder_alloc_is_mapped(struct binder_alloc *alloc)
+{
+	/* pairs with smp_store_release in binder_alloc_set_mapped() */
+	return smp_load_acquire(&alloc->mapped);
+}
+
+static struct page *binder_page_lookup(struct binder_alloc *alloc,
+				       unsigned long addr)
+{
+	struct mm_struct *mm = alloc->mm;
+	struct page *page;
+	long npages = 0;
 
 	/*
-	 * Protected with mmap_sem in write mode as multiple tasks
-	 * might race to install the same page.
+	 * Find an existing page in the remote mm. If missing,
+	 * don't attempt to fault-in just propagate an error.
 	 */
-	mmap_write_lock(alloc->mm);
-	if (binder_get_installed_page(lru_page))
-		goto out;
+	mmap_read_lock(mm);
+	if (binder_alloc_is_mapped(alloc))
+		npages = get_user_pages_remote(mm, addr, 1, FOLL_NOFAULT,
+					       &page, NULL);
+	mmap_read_unlock(mm);
 
-	if (!alloc->vma) {
-		pr_err("%d: %s failed, no vma\n", alloc->pid, __func__);
-		ret = -ESRCH;
-		goto out;
+	return npages > 0 ? page : NULL;
+}
+
+static int binder_page_insert(struct binder_alloc *alloc,
+			      unsigned long addr,
+			      struct page *page)
+{
+	struct mm_struct *mm = alloc->mm;
+	struct vm_area_struct *vma;
+	int ret = -ESRCH;
+
+	/* attempt per-vma lock first */
+	vma = lock_vma_under_rcu(mm, addr);
+	if (vma) {
+		if (binder_alloc_is_mapped(alloc))
+			ret = vm_insert_page(vma, addr, page);
+		vma_end_read(vma);
+		return ret;
 	}
 
+	/* fall back to mmap_lock */
+	mmap_read_lock(mm);
+	vma = vma_lookup(mm, addr);
+	if (vma && binder_alloc_is_mapped(alloc))
+		ret = vm_insert_page(vma, addr, page);
+	mmap_read_unlock(mm);
+
+	return ret;
+}
+
+static struct page *binder_page_alloc(struct binder_alloc *alloc,
+				      unsigned long index)
+{
+	struct binder_shrinker_mdata *mdata;
+	struct page *page;
+
 	page = alloc_page(GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
+	if (!page)
+		return NULL;
+
+	/* allocate and install shrinker metadata under page->private */
+	mdata = kzalloc(sizeof(*mdata), GFP_KERNEL);
+	if (!mdata) {
+		__free_page(page);
+		return NULL;
+	}
+
+	mdata->alloc = alloc;
+	mdata->page_index = index;
+	INIT_LIST_HEAD(&mdata->lru);
+	set_page_private(page, (unsigned long)mdata);
+
+	return page;
+}
+
+static void binder_free_page(struct page *page)
+{
+	kfree((struct binder_shrinker_mdata *)page_private(page));
+	__free_page(page);
+}
+
+static int binder_install_single_page(struct binder_alloc *alloc,
+				      unsigned long index,
+				      unsigned long addr)
+{
+	struct page *page;
+	int ret;
+
+	if (!mmget_not_zero(alloc->mm))
+		return -ESRCH;
+
+	page = binder_page_alloc(alloc, index);
 	if (!page) {
-		pr_err("%d: failed to allocate page\n", alloc->pid);
 		ret = -ENOMEM;
 		goto out;
 	}
 
-	ret = vm_insert_page(alloc->vma, addr, page);
-	if (ret) {
+	ret = binder_page_insert(alloc, addr, page);
+	switch (ret) {
+	case -EBUSY:
+		/*
+		 * EBUSY is ok. Someone installed the pte first but the
+		 * alloc->pages[index] has not been updated yet. Discard
+		 * our page and look up the one already installed.
+		 */
+		ret = 0;
+		binder_free_page(page);
+		page = binder_page_lookup(alloc, addr);
+		if (!page) {
+			pr_err("%d: failed to find page at offset %lx\n",
+			       alloc->pid, addr - alloc->vm_start);
+			ret = -ESRCH;
+			break;
+		}
+		fallthrough;
+	case 0:
+		/* Mark page installation complete and safe to use */
+		binder_set_installed_page(alloc, index, page);
+		break;
+	default:
+		binder_free_page(page);
 		pr_err("%d: %s failed to insert page at offset %lx with %d\n",
-		       alloc->pid, __func__, addr - alloc->buffer, ret);
-		__free_page(page);
-		ret = -ENOMEM;
-		goto out;
+		       alloc->pid, __func__, addr - alloc->vm_start, ret);
+		break;
 	}
-
-	/* Mark page installation complete and safe to use */
-	binder_set_installed_page(lru_page, page);
 out:
-	mmap_write_unlock(alloc->mm);
 	mmput_async(alloc->mm);
 	return ret;
 }
@@ -269,7 +364,6 @@ static int binder_install_buffer_pages(struct binder_alloc *alloc,
 				       struct binder_buffer *buffer,
 				       size_t size)
 {
-	struct binder_lru_page *page;
 	unsigned long start, final;
 	unsigned long page_addr;
 
@@ -280,15 +374,13 @@ static int binder_install_buffer_pages(struct binder_alloc *alloc,
 		unsigned long index;
 		int ret;
 
-		index = (page_addr - alloc->buffer) / PAGE_SIZE;
-		page = &alloc->pages[index];
-
-		if (binder_get_installed_page(page))
+		index = (page_addr - alloc->vm_start) / PAGE_SIZE;
+		if (binder_get_installed_page(alloc, index))
 			continue;
 
 		trace_binder_alloc_page_start(alloc, index);
 
-		ret = binder_install_single_page(alloc, page, page_addr);
+		ret = binder_install_single_page(alloc, index, page_addr);
 		if (ret)
 			return ret;
 
@@ -302,8 +394,8 @@ static int binder_install_buffer_pages(struct binder_alloc *alloc,
 static void binder_lru_freelist_del(struct binder_alloc *alloc,
 				    unsigned long start, unsigned long end)
 {
-	struct binder_lru_page *page;
 	unsigned long page_addr;
+	struct page *page;
 
 	trace_binder_update_page_range(alloc, true, start, end);
 
@@ -311,13 +403,16 @@ static void binder_lru_freelist_del(struct binder_alloc *alloc,
 		unsigned long index;
 		bool on_lru;
 
-		index = (page_addr - alloc->buffer) / PAGE_SIZE;
-		page = &alloc->pages[index];
+		index = (page_addr - alloc->vm_start) / PAGE_SIZE;
+		page = binder_get_installed_page(alloc, index);
 
-		if (page->page_ptr) {
+		if (page) {
 			trace_binder_alloc_lru_start(alloc, index);
 
-			on_lru = list_lru_del_obj(&binder_freelist, &page->lru);
+			on_lru = list_lru_del(&binder_freelist,
+					      page_to_lru(page),
+					      page_to_nid(page),
+					      NULL);
 			WARN_ON(!on_lru);
 
 			trace_binder_alloc_lru_end(alloc, index);
@@ -329,20 +424,6 @@ static void binder_lru_freelist_del(struct binder_alloc *alloc,
 	}
 }
 
-static inline void binder_alloc_set_vma(struct binder_alloc *alloc,
-		struct vm_area_struct *vma)
-{
-	/* pairs with smp_load_acquire in binder_alloc_get_vma() */
-	smp_store_release(&alloc->vma, vma);
-}
-
-static inline struct vm_area_struct *binder_alloc_get_vma(
-		struct binder_alloc *alloc)
-{
-	/* pairs with smp_store_release in binder_alloc_set_vma() */
-	return smp_load_acquire(&alloc->vma);
-}
-
 static void debug_no_space_locked(struct binder_alloc *alloc)
 {
 	size_t largest_alloc_size = 0;
@@ -576,7 +657,7 @@ struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
 	int ret;
 
 	/* Check binder_alloc is fully initialized */
-	if (!binder_alloc_get_vma(alloc)) {
+	if (!binder_alloc_is_mapped(alloc)) {
 		binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
 				   "%d: binder_alloc_buf, no vma\n",
 				   alloc->pid);
@@ -597,10 +678,10 @@ struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
 	if (!next)
 		return ERR_PTR(-ENOMEM);
 
-	spin_lock(&alloc->lock);
+	mutex_lock(&alloc->mutex);
 	buffer = binder_alloc_new_buf_locked(alloc, next, size, is_async);
 	if (IS_ERR(buffer)) {
-		spin_unlock(&alloc->lock);
+		mutex_unlock(&alloc->mutex);
 		goto out;
 	}
 
@@ -608,7 +689,7 @@ struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
 	buffer->offsets_size = offsets_size;
 	buffer->extra_buffers_size = extra_buffers_size;
 	buffer->pid = current->tgid;
-	spin_unlock(&alloc->lock);
+	mutex_unlock(&alloc->mutex);
 
 	ret = binder_install_buffer_pages(alloc, buffer, size);
 	if (ret) {
@@ -674,8 +755,8 @@ static void binder_free_buf_locked(struct binder_alloc *alloc,
 	BUG_ON(buffer->free);
 	BUG_ON(size > buffer_size);
 	BUG_ON(buffer->transaction != NULL);
-	BUG_ON(buffer->user_data < alloc->buffer);
-	BUG_ON(buffer->user_data > alloc->buffer + alloc->buffer_size);
+	BUG_ON(buffer->user_data < alloc->vm_start);
+	BUG_ON(buffer->user_data > alloc->vm_start + alloc->buffer_size);
 
 	if (buffer->async_transaction) {
 		alloc->free_async_space += buffer_size;
@@ -734,14 +815,13 @@ static struct page *binder_alloc_get_page(struct binder_alloc *alloc,
 					  pgoff_t *pgoffp)
 {
 	binder_size_t buffer_space_offset = buffer_offset +
-		(buffer->user_data - alloc->buffer);
+		(buffer->user_data - alloc->vm_start);
 	pgoff_t pgoff = buffer_space_offset & ~PAGE_MASK;
 	size_t index = buffer_space_offset >> PAGE_SHIFT;
-	struct binder_lru_page *lru_page;
 
-	lru_page = &alloc->pages[index];
 	*pgoffp = pgoff;
-	return lru_page->page_ptr;
+
+	return alloc->pages[index];
 }
 
 /**
@@ -785,17 +865,17 @@ void binder_alloc_free_buf(struct binder_alloc *alloc,
 	 * We could eliminate the call to binder_alloc_clear_buf()
 	 * from binder_alloc_deferred_release() by moving this to
 	 * binder_free_buf_locked(). However, that could
-	 * increase contention for the alloc->lock if clear_on_free
-	 * is used frequently for large buffers. This lock is not
+	 * increase contention for the alloc mutex if clear_on_free
+	 * is used frequently for large buffers. The mutex is not
 	 * needed for correctness here.
 	 */
 	if (buffer->clear_on_free) {
 		binder_alloc_clear_buf(alloc, buffer);
 		buffer->clear_on_free = false;
 	}
-	spin_lock(&alloc->lock);
+	mutex_lock(&alloc->mutex);
 	binder_free_buf_locked(alloc, buffer);
-	spin_unlock(&alloc->lock);
+	mutex_unlock(&alloc->mutex);
 }
 
 /**
@@ -816,7 +896,7 @@ int binder_alloc_mmap_handler(struct binder_alloc *alloc,
 {
 	struct binder_buffer *buffer;
 	const char *failure_string;
-	int ret, i;
+	int ret;
 
 	if (unlikely(vma->vm_mm != alloc->mm)) {
 		ret = -EINVAL;
@@ -834,22 +914,17 @@ int binder_alloc_mmap_handler(struct binder_alloc *alloc,
 				   SZ_4M);
 	mutex_unlock(&binder_alloc_mmap_lock);
 
-	alloc->buffer = vma->vm_start;
+	alloc->vm_start = vma->vm_start;
 
 	alloc->pages = kvcalloc(alloc->buffer_size / PAGE_SIZE,
 				sizeof(alloc->pages[0]),
 				GFP_KERNEL);
-	if (alloc->pages == NULL) {
+	if (!alloc->pages) {
 		ret = -ENOMEM;
 		failure_string = "alloc page array";
 		goto err_alloc_pages_failed;
 	}
 
-	for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
-		alloc->pages[i].alloc = alloc;
-		INIT_LIST_HEAD(&alloc->pages[i].lru);
-	}
-
 	buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 	if (!buffer) {
 		ret = -ENOMEM;
@@ -857,14 +932,14 @@ int binder_alloc_mmap_handler(struct binder_alloc *alloc,
 		goto err_alloc_buf_struct_failed;
 	}
 
-	buffer->user_data = alloc->buffer;
+	buffer->user_data = alloc->vm_start;
 	list_add(&buffer->entry, &alloc->buffers);
 	buffer->free = 1;
 	binder_insert_free_buffer(alloc, buffer);
 	alloc->free_async_space = alloc->buffer_size / 2;
 
 	/* Signal binder_alloc is fully initialized */
-	binder_alloc_set_vma(alloc, vma);
+	binder_alloc_set_mapped(alloc, true);
 
 	return 0;
 
@@ -872,7 +947,7 @@ err_alloc_buf_struct_failed:
 	kvfree(alloc->pages);
 	alloc->pages = NULL;
 err_alloc_pages_failed:
-	alloc->buffer = 0;
+	alloc->vm_start = 0;
 	mutex_lock(&binder_alloc_mmap_lock);
 	alloc->buffer_size = 0;
 err_already_mapped:
@@ -893,8 +968,8 @@ void binder_alloc_deferred_release(struct binder_alloc *alloc)
 	struct binder_buffer *buffer;
 
 	buffers = 0;
-	spin_lock(&alloc->lock);
-	BUG_ON(alloc->vma);
+	mutex_lock(&alloc->mutex);
+	BUG_ON(alloc->mapped);
 
 	while ((n = rb_first(&alloc->allocated_buffers))) {
 		buffer = rb_entry(n, struct binder_buffer, rb_node);
@@ -925,22 +1000,26 @@ void binder_alloc_deferred_release(struct binder_alloc *alloc)
 		int i;
 
 		for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
+			struct page *page;
 			bool on_lru;
 
-			if (!alloc->pages[i].page_ptr)
+			page = binder_get_installed_page(alloc, i);
+			if (!page)
 				continue;
 
-			on_lru = list_lru_del_obj(&binder_freelist,
-						  &alloc->pages[i].lru);
+			on_lru = list_lru_del(&binder_freelist,
+					      page_to_lru(page),
+					      page_to_nid(page),
+					      NULL);
 			binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
 				     "%s: %d: page %d %s\n",
 				     __func__, alloc->pid, i,
 				     on_lru ? "on lru" : "active");
-			__free_page(alloc->pages[i].page_ptr);
+			binder_free_page(page);
 			page_count++;
 		}
 	}
-	spin_unlock(&alloc->lock);
+	mutex_unlock(&alloc->mutex);
 	kvfree(alloc->pages);
 	if (alloc->mm)
 		mmdrop(alloc->mm);
@@ -964,17 +1043,17 @@ void binder_alloc_print_allocated(struct seq_file *m,
 	struct binder_buffer *buffer;
 	struct rb_node *n;
 
-	spin_lock(&alloc->lock);
+	mutex_lock(&alloc->mutex);
 	for (n = rb_first(&alloc->allocated_buffers); n; n = rb_next(n)) {
 		buffer = rb_entry(n, struct binder_buffer, rb_node);
 		seq_printf(m, "  buffer %d: %lx size %zd:%zd:%zd %s\n",
 			   buffer->debug_id,
-			   buffer->user_data - alloc->buffer,
+			   buffer->user_data - alloc->vm_start,
 			   buffer->data_size, buffer->offsets_size,
 			   buffer->extra_buffers_size,
 			   buffer->transaction ? "active" : "delivered");
 	}
-	spin_unlock(&alloc->lock);
+	mutex_unlock(&alloc->mutex);
 }
 
 /**
@@ -985,29 +1064,29 @@ void binder_alloc_print_allocated(struct seq_file *m,
 void binder_alloc_print_pages(struct seq_file *m,
 			      struct binder_alloc *alloc)
 {
-	struct binder_lru_page *page;
+	struct page *page;
 	int i;
 	int active = 0;
 	int lru = 0;
 	int free = 0;
 
-	spin_lock(&alloc->lock);
+	mutex_lock(&alloc->mutex);
 	/*
 	 * Make sure the binder_alloc is fully initialized, otherwise we might
 	 * read inconsistent state.
 	 */
-	if (binder_alloc_get_vma(alloc) != NULL) {
+	if (binder_alloc_is_mapped(alloc)) {
 		for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
-			page = &alloc->pages[i];
-			if (!page->page_ptr)
+			page = binder_get_installed_page(alloc, i);
+			if (!page)
 				free++;
-			else if (list_empty(&page->lru))
+			else if (list_empty(page_to_lru(page)))
 				active++;
 			else
 				lru++;
 		}
 	}
-	spin_unlock(&alloc->lock);
+	mutex_unlock(&alloc->mutex);
 	seq_printf(m, "  pages: %d:%d:%d\n", active, lru, free);
 	seq_printf(m, "  pages high watermark: %zu\n", alloc->pages_high);
 }
@@ -1023,10 +1102,10 @@ int binder_alloc_get_allocated_count(struct binder_alloc *alloc)
 	struct rb_node *n;
 	int count = 0;
 
-	spin_lock(&alloc->lock);
+	mutex_lock(&alloc->mutex);
 	for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n))
 		count++;
-	spin_unlock(&alloc->lock);
+	mutex_unlock(&alloc->mutex);
 	return count;
 }
 
@@ -1036,12 +1115,12 @@ int binder_alloc_get_allocated_count(struct binder_alloc *alloc)
  * @alloc: binder_alloc for this proc
  *
  * Called from binder_vma_close() when releasing address space.
- * Clears alloc->vma to prevent new incoming transactions from
+ * Clears alloc->mapped to prevent new incoming transactions from
  * allocating more buffers.
  */
 void binder_alloc_vma_close(struct binder_alloc *alloc)
 {
-	binder_alloc_set_vma(alloc, NULL);
+	binder_alloc_set_mapped(alloc, false);
 }
 
 /**
@@ -1058,39 +1137,50 @@ enum lru_status binder_alloc_free_page(struct list_head *item,
 				       void *cb_arg)
 	__must_hold(&lru->lock)
 {
-	struct binder_lru_page *page = container_of(item, typeof(*page), lru);
-	struct binder_alloc *alloc = page->alloc;
+	struct binder_shrinker_mdata *mdata = container_of(item, typeof(*mdata), lru);
+	struct binder_alloc *alloc = mdata->alloc;
 	struct mm_struct *mm = alloc->mm;
 	struct vm_area_struct *vma;
 	struct page *page_to_free;
 	unsigned long page_addr;
+	int mm_locked = 0;
 	size_t index;
 
 	if (!mmget_not_zero(mm))
 		goto err_mmget;
-	if (!mmap_read_trylock(mm))
-		goto err_mmap_read_lock_failed;
-	if (!spin_trylock(&alloc->lock))
-		goto err_get_alloc_lock_failed;
-	if (!page->page_ptr)
-		goto err_page_already_freed;
-
-	index = page - alloc->pages;
-	page_addr = alloc->buffer + index * PAGE_SIZE;
-
-	vma = vma_lookup(mm, page_addr);
-	if (vma && vma != binder_alloc_get_vma(alloc))
+
+	index = mdata->page_index;
+	page_addr = alloc->vm_start + index * PAGE_SIZE;
+
+	/* attempt per-vma lock first */
+	vma = lock_vma_under_rcu(mm, page_addr);
+	if (!vma) {
+		/* fall back to mmap_lock */
+		if (!mmap_read_trylock(mm))
+			goto err_mmap_read_lock_failed;
+		mm_locked = 1;
+		vma = vma_lookup(mm, page_addr);
+	}
+
+	if (!mutex_trylock(&alloc->mutex))
+		goto err_get_alloc_mutex_failed;
+
+	/*
+	 * Since a binder_alloc can only be mapped once, we ensure
+	 * the vma corresponds to this mapping by checking whether
+	 * the binder_alloc is still mapped.
+	 */
+	if (vma && !binder_alloc_is_mapped(alloc))
 		goto err_invalid_vma;
 
 	trace_binder_unmap_kernel_start(alloc, index);
 
-	page_to_free = page->page_ptr;
-	page->page_ptr = NULL;
+	page_to_free = alloc->pages[index];
+	binder_set_installed_page(alloc, index, NULL);
 
 	trace_binder_unmap_kernel_end(alloc, index);
 
 	list_lru_isolate(lru, item);
-	spin_unlock(&alloc->lock);
 	spin_unlock(&lru->lock);
 
 	if (vma) {
@@ -1101,17 +1191,23 @@ enum lru_status binder_alloc_free_page(struct list_head *item,
 		trace_binder_unmap_user_end(alloc, index);
 	}
 
-	mmap_read_unlock(mm);
+	mutex_unlock(&alloc->mutex);
+	if (mm_locked)
+		mmap_read_unlock(mm);
+	else
+		vma_end_read(vma);
 	mmput_async(mm);
-	__free_page(page_to_free);
+	binder_free_page(page_to_free);
 
 	return LRU_REMOVED_RETRY;
 
 err_invalid_vma:
-err_page_already_freed:
-	spin_unlock(&alloc->lock);
-err_get_alloc_lock_failed:
-	mmap_read_unlock(mm);
+	mutex_unlock(&alloc->mutex);
+err_get_alloc_mutex_failed:
+	if (mm_locked)
+		mmap_read_unlock(mm);
+	else
+		vma_end_read(vma);
 err_mmap_read_lock_failed:
 	mmput_async(mm);
 err_mmget:
@@ -1145,7 +1241,7 @@ void binder_alloc_init(struct binder_alloc *alloc)
 	alloc->pid = current->group_leader->pid;
 	alloc->mm = current->mm;
 	mmgrab(alloc->mm);
-	spin_lock_init(&alloc->lock);
+	mutex_init(&alloc->mutex);
 	INIT_LIST_HEAD(&alloc->buffers);
 }
 
diff --git a/drivers/android/binder_alloc.h b/drivers/android/binder_alloc.h
index c02c8ebcb466..feecd7414241 100644
--- a/drivers/android/binder_alloc.h
+++ b/drivers/android/binder_alloc.h
@@ -9,7 +9,7 @@
 #include <linux/rbtree.h>
 #include <linux/list.h>
 #include <linux/mm.h>
-#include <linux/spinlock.h>
+#include <linux/rtmutex.h>
 #include <linux/vmalloc.h>
 #include <linux/slab.h>
 #include <linux/list_lru.h>
@@ -59,34 +59,43 @@ struct binder_buffer {
 };
 
 /**
- * struct binder_lru_page - page object used for binder shrinker
- * @page_ptr: pointer to physical page in mmap'd space
- * @lru:      entry in binder_freelist
- * @alloc:    binder_alloc for a proc
+ * struct binder_shrinker_mdata - binder metadata used to reclaim pages
+ * @lru:         LRU entry in binder_freelist
+ * @alloc:       binder_alloc owning the page to reclaim
+ * @page_index:  offset in @alloc->pages[] into the page to reclaim
  */
-struct binder_lru_page {
+struct binder_shrinker_mdata {
 	struct list_head lru;
-	struct page *page_ptr;
 	struct binder_alloc *alloc;
+	unsigned long page_index;
 };
 
+static inline struct list_head *page_to_lru(struct page *p)
+{
+	struct binder_shrinker_mdata *mdata;
+
+	mdata = (struct binder_shrinker_mdata *)page_private(p);
+
+	return &mdata->lru;
+}
+
 /**
  * struct binder_alloc - per-binder proc state for binder allocator
- * @lock:               protects binder_alloc fields
- * @vma:                vm_area_struct passed to mmap_handler
- *                      (invariant after mmap)
+ * @mutex:              protects binder_alloc fields
  * @mm:                 copy of task->mm (invariant after open)
- * @buffer:             base of per-proc address space mapped via mmap
+ * @vm_start:           base of per-proc address space mapped via mmap
  * @buffers:            list of all buffers for this proc
  * @free_buffers:       rb tree of buffers available for allocation
  *                      sorted by size
  * @allocated_buffers:  rb tree of allocated buffers sorted by address
  * @free_async_space:   VA space available for async buffers. This is
  *                      initialized at mmap time to 1/2 the full VA space
- * @pages:              array of binder_lru_page
+ * @pages:              array of struct page *
  * @buffer_size:        size of address space specified via mmap
  * @pid:                pid for associated binder_proc (invariant after init)
  * @pages_high:         high watermark of offset in @pages
+ * @mapped:             whether the vm area is mapped, each binder instance is
+ *                      allowed a single mapping throughout its lifetime
  * @oneway_spam_detected: %true if oneway spam detection fired, clear that
  * flag once the async buffer has returned to a healthy state
  *
@@ -96,18 +105,18 @@ struct binder_lru_page {
  * struct binder_buffer objects used to track the user buffers
  */
 struct binder_alloc {
-	spinlock_t lock;
-	struct vm_area_struct *vma;
+	struct mutex mutex;
 	struct mm_struct *mm;
-	unsigned long buffer;
+	unsigned long vm_start;
 	struct list_head buffers;
 	struct rb_root free_buffers;
 	struct rb_root allocated_buffers;
 	size_t free_async_space;
-	struct binder_lru_page *pages;
+	struct page **pages;
 	size_t buffer_size;
 	int pid;
 	size_t pages_high;
+	bool mapped;
 	bool oneway_spam_detected;
 };
 
@@ -153,9 +162,9 @@ binder_alloc_get_free_async_space(struct binder_alloc *alloc)
 {
 	size_t free_async_space;
 
-	spin_lock(&alloc->lock);
+	mutex_lock(&alloc->mutex);
 	free_async_space = alloc->free_async_space;
-	spin_unlock(&alloc->lock);
+	mutex_unlock(&alloc->mutex);
 	return free_async_space;
 }
 
diff --git a/drivers/android/binder_alloc_selftest.c b/drivers/android/binder_alloc_selftest.c
index 81442fe20a69..c88735c54848 100644
--- a/drivers/android/binder_alloc_selftest.c
+++ b/drivers/android/binder_alloc_selftest.c
@@ -104,11 +104,11 @@ static bool check_buffer_pages_allocated(struct binder_alloc *alloc,
 	end = PAGE_ALIGN(buffer->user_data + size);
 	page_addr = buffer->user_data;
 	for (; page_addr < end; page_addr += PAGE_SIZE) {
-		page_index = (page_addr - alloc->buffer) / PAGE_SIZE;
-		if (!alloc->pages[page_index].page_ptr ||
-		    !list_empty(&alloc->pages[page_index].lru)) {
+		page_index = (page_addr - alloc->vm_start) / PAGE_SIZE;
+		if (!alloc->pages[page_index] ||
+		    !list_empty(page_to_lru(alloc->pages[page_index]))) {
 			pr_err("expect alloc but is %s at page index %d\n",
-			       alloc->pages[page_index].page_ptr ?
+			       alloc->pages[page_index] ?
 			       "lru" : "free", page_index);
 			return false;
 		}
@@ -148,10 +148,10 @@ static void binder_selftest_free_buf(struct binder_alloc *alloc,
 		 * if binder shrinker ran during binder_alloc_free_buf
 		 * calls above.
 		 */
-		if (list_empty(&alloc->pages[i].lru)) {
+		if (list_empty(page_to_lru(alloc->pages[i]))) {
 			pr_err_size_seq(sizes, seq);
 			pr_err("expect lru but is %s at page index %d\n",
-			       alloc->pages[i].page_ptr ? "alloc" : "free", i);
+			       alloc->pages[i] ? "alloc" : "free", i);
 			binder_selftest_failures++;
 		}
 	}
@@ -168,9 +168,9 @@ static void binder_selftest_free_page(struct binder_alloc *alloc)
 	}
 
 	for (i = 0; i < (alloc->buffer_size / PAGE_SIZE); i++) {
-		if (alloc->pages[i].page_ptr) {
+		if (alloc->pages[i]) {
 			pr_err("expect free but is %s at page index %d\n",
-			       list_empty(&alloc->pages[i].lru) ?
+			       list_empty(page_to_lru(alloc->pages[i])) ?
 			       "alloc" : "lru", i);
 			binder_selftest_failures++;
 		}
@@ -291,7 +291,7 @@ void binder_selftest_alloc(struct binder_alloc *alloc)
 	if (!binder_selftest_run)
 		return;
 	mutex_lock(&binder_selftest_lock);
-	if (!binder_selftest_run || !alloc->vma)
+	if (!binder_selftest_run || !alloc->mapped)
 		goto done;
 	pr_info("STARTED\n");
 	binder_selftest_alloc_offset(alloc, end_offset, 0);
diff --git a/drivers/android/binder_internal.h b/drivers/android/binder_internal.h
index f8d6be682f23..e4eb8357989c 100644
--- a/drivers/android/binder_internal.h
+++ b/drivers/android/binder_internal.h
@@ -25,8 +25,7 @@ struct binder_context {
 
 /**
  * struct binder_device - information about a binder device node
- * @hlist:          list of binder devices (only used for devices requested via
- *                  CONFIG_ANDROID_BINDER_DEVICES)
+ * @hlist:          list of binder devices
  * @miscdev:        information about a binder character device node
  * @context:        binder context information
  * @binderfs_inode: This is the inode of the root dentry of the super block
@@ -582,4 +581,12 @@ struct binder_object {
 	};
 };
 
+/**
+ * Add a binder device to binder_devices
+ * @device: the new binder device to add to the global list
+ *
+ * Not reentrant as the list is not protected by any locks
+ */
+void binder_add_device(struct binder_device *device);
+
 #endif /* _LINUX_BINDER_INTERNAL_H */
diff --git a/drivers/android/binder_trace.h b/drivers/android/binder_trace.h
index fe38c6fc65d0..16de1b9e72f7 100644
--- a/drivers/android/binder_trace.h
+++ b/drivers/android/binder_trace.h
@@ -328,7 +328,7 @@ TRACE_EVENT(binder_update_page_range,
 	TP_fast_assign(
 		__entry->proc = alloc->pid;
 		__entry->allocate = allocate;
-		__entry->offset = start - alloc->buffer;
+		__entry->offset = start - alloc->vm_start;
 		__entry->size = end - start;
 	),
 	TP_printk("proc=%d allocate=%d offset=%zu size=%zu",
diff --git a/drivers/android/binderfs.c b/drivers/android/binderfs.c
index ad1fa7abc323..94c6446604fc 100644
--- a/drivers/android/binderfs.c
+++ b/drivers/android/binderfs.c
@@ -207,6 +207,8 @@ static int binderfs_binder_device_create(struct inode *ref_inode,
 	fsnotify_create(root->d_inode, dentry);
 	inode_unlock(d_inode(root));
 
+	binder_add_device(device);
+
 	return 0;
 
 err:
@@ -272,6 +274,7 @@ static void binderfs_evict_inode(struct inode *inode)
 	mutex_unlock(&binderfs_minors_mutex);
 
 	if (refcount_dec_and_test(&device->ref)) {
+		hlist_del_init(&device->hlist);
 		kfree(device->context.name);
 		kfree(device);
 	}