Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 719 insertions, 0 deletions

diff --git a/tools/testing/radix-tree/multiorder.c b/tools/testing/radix-tree/multiorder.c
new file mode 100644
index 000000000..7bf405638
--- /dev/null
+++ b/tools/testing/radix-tree/multiorder.c
@@ -0,0 +1,719 @@
+/*
+ * multiorder.c: Multi-order radix tree entry testing
+ * Copyright (c) 2016 Intel Corporation
+ * Author: Ross Zwisler <ross.zwisler@linux.intel.com>
+ * Author: Matthew Wilcox <matthew.r.wilcox@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+#include <linux/radix-tree.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <pthread.h>
+
+#include "test.h"
+
+#define for_each_index(i, base, order) \
+	for (i = base; i < base + (1 << order); i++)
+
+static void __multiorder_tag_test(int index, int order)
+{
+	RADIX_TREE(tree, GFP_KERNEL);
+	int base, err, i;
+
+	/* our canonical entry */
+	base = index & ~((1 << order) - 1);
+
+	printv(2, "Multiorder tag test with index %d, canonical entry %d\n",
+			index, base);
+
+	err = item_insert_order(&tree, index, order);
+	assert(!err);
+
+	/*
+	 * Verify we get collisions for covered indices.  We try and fail to
+	 * insert an exceptional entry so we don't leak memory via
+	 * item_insert_order().
+	 */
+	for_each_index(i, base, order) {
+		err = __radix_tree_insert(&tree, i, order,
+				(void *)(0xA0 | RADIX_TREE_EXCEPTIONAL_ENTRY));
+		assert(err == -EEXIST);
+	}
+
+	for_each_index(i, base, order) {
+		assert(!radix_tree_tag_get(&tree, i, 0));
+		assert(!radix_tree_tag_get(&tree, i, 1));
+	}
+
+	assert(radix_tree_tag_set(&tree, index, 0));
+
+	for_each_index(i, base, order) {
+		assert(radix_tree_tag_get(&tree, i, 0));
+		assert(!radix_tree_tag_get(&tree, i, 1));
+	}
+
+	assert(tag_tagged_items(&tree, NULL, 0, ~0UL, 10, 0, 1) == 1);
+	assert(radix_tree_tag_clear(&tree, index, 0));
+
+	for_each_index(i, base, order) {
+		assert(!radix_tree_tag_get(&tree, i, 0));
+		assert(radix_tree_tag_get(&tree, i, 1));
+	}
+
+	assert(radix_tree_tag_clear(&tree, index, 1));
+
+	assert(!radix_tree_tagged(&tree, 0));
+	assert(!radix_tree_tagged(&tree, 1));
+
+	item_kill_tree(&tree);
+}
+
+static void __multiorder_tag_test2(unsigned order, unsigned long index2)
+{
+	RADIX_TREE(tree, GFP_KERNEL);
+	unsigned long index = (1 << order);
+	index2 += index;
+
+	assert(item_insert_order(&tree, 0, order) == 0);
+	assert(item_insert(&tree, index2) == 0);
+
+	assert(radix_tree_tag_set(&tree, 0, 0));
+	assert(radix_tree_tag_set(&tree, index2, 0));
+
+	assert(tag_tagged_items(&tree, NULL, 0, ~0UL, 10, 0, 1) == 2);
+
+	item_kill_tree(&tree);
+}
+
+static void multiorder_tag_tests(void)
+{
+	int i, j;
+
+	/* test multi-order entry for indices 0-7 with no sibling pointers */
+	__multiorder_tag_test(0, 3);
+	__multiorder_tag_test(5, 3);
+
+	/* test multi-order entry for indices 8-15 with no sibling pointers */
+	__multiorder_tag_test(8, 3);
+	__multiorder_tag_test(15, 3);
+
+	/*
+	 * Our order 5 entry covers indices 0-31 in a tree with height=2.
+	 * This is broken up as follows:
+	 * 0-7:		canonical entry
+	 * 8-15:	sibling 1
+	 * 16-23:	sibling 2
+	 * 24-31:	sibling 3
+	 */
+	__multiorder_tag_test(0, 5);
+	__multiorder_tag_test(29, 5);
+
+	/* same test, but with indices 32-63 */
+	__multiorder_tag_test(32, 5);
+	__multiorder_tag_test(44, 5);
+
+	/*
+	 * Our order 8 entry covers indices 0-255 in a tree with height=3.
+	 * This is broken up as follows:
+	 * 0-63:	canonical entry
+	 * 64-127:	sibling 1
+	 * 128-191:	sibling 2
+	 * 192-255:	sibling 3
+	 */
+	__multiorder_tag_test(0, 8);
+	__multiorder_tag_test(190, 8);
+
+	/* same test, but with indices 256-511 */
+	__multiorder_tag_test(256, 8);
+	__multiorder_tag_test(300, 8);
+
+	__multiorder_tag_test(0x12345678UL, 8);
+
+	for (i = 1; i < 10; i++)
+		for (j = 0; j < (10 << i); j++)
+			__multiorder_tag_test2(i, j);
+}
+
+static void multiorder_check(unsigned long index, int order)
+{
+	unsigned long i;
+	unsigned long min = index & ~((1UL << order) - 1);
+	unsigned long max = min + (1UL << order);
+	void **slot;
+	struct item *item2 = item_create(min, order);
+	RADIX_TREE(tree, GFP_KERNEL);
+
+	printv(2, "Multiorder index %ld, order %d\n", index, order);
+
+	assert(item_insert_order(&tree, index, order) == 0);
+
+	for (i = min; i < max; i++) {
+		struct item *item = item_lookup(&tree, i);
+		assert(item != 0);
+		assert(item->index == index);
+	}
+	for (i = 0; i < min; i++)
+		item_check_absent(&tree, i);
+	for (i = max; i < 2*max; i++)
+		item_check_absent(&tree, i);
+	for (i = min; i < max; i++)
+		assert(radix_tree_insert(&tree, i, item2) == -EEXIST);
+
+	slot = radix_tree_lookup_slot(&tree, index);
+	free(*slot);
+	radix_tree_replace_slot(&tree, slot, item2);
+	for (i = min; i < max; i++) {
+		struct item *item = item_lookup(&tree, i);
+		assert(item != 0);
+		assert(item->index == min);
+	}
+
+	assert(item_delete(&tree, min) != 0);
+
+	for (i = 0; i < 2*max; i++)
+		item_check_absent(&tree, i);
+}
+
+static void multiorder_shrink(unsigned long index, int order)
+{
+	unsigned long i;
+	unsigned long max = 1 << order;
+	RADIX_TREE(tree, GFP_KERNEL);
+	struct radix_tree_node *node;
+
+	printv(2, "Multiorder shrink index %ld, order %d\n", index, order);
+
+	assert(item_insert_order(&tree, 0, order) == 0);
+
+	node = tree.rnode;
+
+	assert(item_insert(&tree, index) == 0);
+	assert(node != tree.rnode);
+
+	assert(item_delete(&tree, index) != 0);
+	assert(node == tree.rnode);
+
+	for (i = 0; i < max; i++) {
+		struct item *item = item_lookup(&tree, i);
+		assert(item != 0);
+		assert(item->index == 0);
+	}
+	for (i = max; i < 2*max; i++)
+		item_check_absent(&tree, i);
+
+	if (!item_delete(&tree, 0)) {
+		printv(2, "failed to delete index %ld (order %d)\n", index, order);
+		abort();
+	}
+
+	for (i = 0; i < 2*max; i++)
+		item_check_absent(&tree, i);
+}
+
+static void multiorder_insert_bug(void)
+{
+	RADIX_TREE(tree, GFP_KERNEL);
+
+	item_insert(&tree, 0);
+	radix_tree_tag_set(&tree, 0, 0);
+	item_insert_order(&tree, 3 << 6, 6);
+
+	item_kill_tree(&tree);
+}
+
+void multiorder_iteration(void)
+{
+	RADIX_TREE(tree, GFP_KERNEL);
+	struct radix_tree_iter iter;
+	void **slot;
+	int i, j, err;
+
+	printv(1, "Multiorder iteration test\n");
+
+#define NUM_ENTRIES 11
+	int index[NUM_ENTRIES] = {0, 2, 4, 8, 16, 32, 34, 36, 64, 72, 128};
+	int order[NUM_ENTRIES] = {1, 1, 2, 3,  4,  1,  0,  1,  3,  0, 7};
+
+	for (i = 0; i < NUM_ENTRIES; i++) {
+		err = item_insert_order(&tree, index[i], order[i]);
+		assert(!err);
+	}
+
+	for (j = 0; j < 256; j++) {
+		for (i = 0; i < NUM_ENTRIES; i++)
+			if (j <= (index[i] | ((1 << order[i]) - 1)))
+				break;
+
+		radix_tree_for_each_slot(slot, &tree, &iter, j) {
+			int height = order[i] / RADIX_TREE_MAP_SHIFT;
+			int shift = height * RADIX_TREE_MAP_SHIFT;
+			unsigned long mask = (1UL << order[i]) - 1;
+			struct item *item = *slot;
+
+			assert((iter.index | mask) == (index[i] | mask));
+			assert(iter.shift == shift);
+			assert(!radix_tree_is_internal_node(item));
+			assert((item->index | mask) == (index[i] | mask));
+			assert(item->order == order[i]);
+			i++;
+		}
+	}
+
+	item_kill_tree(&tree);
+}
+
+void multiorder_tagged_iteration(void)
+{
+	RADIX_TREE(tree, GFP_KERNEL);
+	struct radix_tree_iter iter;
+	void **slot;
+	int i, j;
+
+	printv(1, "Multiorder tagged iteration test\n");
+
+#define MT_NUM_ENTRIES 9
+	int index[MT_NUM_ENTRIES] = {0, 2, 4, 16, 32, 40, 64, 72, 128};
+	int order[MT_NUM_ENTRIES] = {1, 0, 2, 4,  3,  1,  3,  0,   7};
+
+#define TAG_ENTRIES 7
+	int tag_index[TAG_ENTRIES] = {0, 4, 16, 40, 64, 72, 128};
+
+	for (i = 0; i < MT_NUM_ENTRIES; i++)
+		assert(!item_insert_order(&tree, index[i], order[i]));
+
+	assert(!radix_tree_tagged(&tree, 1));
+
+	for (i = 0; i < TAG_ENTRIES; i++)
+		assert(radix_tree_tag_set(&tree, tag_index[i], 1));
+
+	for (j = 0; j < 256; j++) {
+		int k;
+
+		for (i = 0; i < TAG_ENTRIES; i++) {
+			for (k = i; index[k] < tag_index[i]; k++)
+				;
+			if (j <= (index[k] | ((1 << order[k]) - 1)))
+				break;
+		}
+
+		radix_tree_for_each_tagged(slot, &tree, &iter, j, 1) {
+			unsigned long mask;
+			struct item *item = *slot;
+			for (k = i; index[k] < tag_index[i]; k++)
+				;
+			mask = (1UL << order[k]) - 1;
+
+			assert((iter.index | mask) == (tag_index[i] | mask));
+			assert(!radix_tree_is_internal_node(item));
+			assert((item->index | mask) == (tag_index[i] | mask));
+			assert(item->order == order[k]);
+			i++;
+		}
+	}
+
+	assert(tag_tagged_items(&tree, NULL, 0, ~0UL, TAG_ENTRIES, 1, 2) ==
+				TAG_ENTRIES);
+
+	for (j = 0; j < 256; j++) {
+		int mask, k;
+
+		for (i = 0; i < TAG_ENTRIES; i++) {
+			for (k = i; index[k] < tag_index[i]; k++)
+				;
+			if (j <= (index[k] | ((1 << order[k]) - 1)))
+				break;
+		}
+
+		radix_tree_for_each_tagged(slot, &tree, &iter, j, 2) {
+			struct item *item = *slot;
+			for (k = i; index[k] < tag_index[i]; k++)
+				;
+			mask = (1 << order[k]) - 1;
+
+			assert((iter.index | mask) == (tag_index[i] | mask));
+			assert(!radix_tree_is_internal_node(item));
+			assert((item->index | mask) == (tag_index[i] | mask));
+			assert(item->order == order[k]);
+			i++;
+		}
+	}
+
+	assert(tag_tagged_items(&tree, NULL, 1, ~0UL, MT_NUM_ENTRIES * 2, 1, 0)
+			== TAG_ENTRIES);
+	i = 0;
+	radix_tree_for_each_tagged(slot, &tree, &iter, 0, 0) {
+		assert(iter.index == tag_index[i]);
+		i++;
+	}
+
+	item_kill_tree(&tree);
+}
+
+/*
+ * Basic join checks: make sure we can't find an entry in the tree after
+ * a larger entry has replaced it
+ */
+static void multiorder_join1(unsigned long index,
+				unsigned order1, unsigned order2)
+{
+	unsigned long loc;
+	void *item, *item2 = item_create(index + 1, order1);
+	RADIX_TREE(tree, GFP_KERNEL);
+
+	item_insert_order(&tree, index, order2);
+	item = radix_tree_lookup(&tree, index);
+	radix_tree_join(&tree, index + 1, order1, item2);
+	loc = find_item(&tree, item);
+	if (loc == -1)
+		free(item);
+	item = radix_tree_lookup(&tree, index + 1);
+	assert(item == item2);
+	item_kill_tree(&tree);
+}
+
+/*
+ * Check that the accounting of exceptional entries is handled correctly
+ * by joining an exceptional entry to a normal pointer.
+ */
+static void multiorder_join2(unsigned order1, unsigned order2)
+{
+	RADIX_TREE(tree, GFP_KERNEL);
+	struct radix_tree_node *node;
+	void *item1 = item_create(0, order1);
+	void *item2;
+
+	item_insert_order(&tree, 0, order2);
+	radix_tree_insert(&tree, 1 << order2, (void *)0x12UL);
+	item2 = __radix_tree_lookup(&tree, 1 << order2, &node, NULL);
+	assert(item2 == (void *)0x12UL);
+	assert(node->exceptional == 1);
+
+	item2 = radix_tree_lookup(&tree, 0);
+	free(item2);
+
+	radix_tree_join(&tree, 0, order1, item1);
+	item2 = __radix_tree_lookup(&tree, 1 << order2, &node, NULL);
+	assert(item2 == item1);
+	assert(node->exceptional == 0);
+	item_kill_tree(&tree);
+}
+
+/*
+ * This test revealed an accounting bug for exceptional entries at one point.
+ * Nodes were being freed back into the pool with an elevated exception count
+ * by radix_tree_join() and then radix_tree_split() was failing to zero the
+ * count of exceptional entries.
+ */
+static void multiorder_join3(unsigned int order)
+{
+	RADIX_TREE(tree, GFP_KERNEL);
+	struct radix_tree_node *node;
+	void **slot;
+	struct radix_tree_iter iter;
+	unsigned long i;
+
+	for (i = 0; i < (1 << order); i++) {
+		radix_tree_insert(&tree, i, (void *)0x12UL);
+	}
+
+	radix_tree_join(&tree, 0, order, (void *)0x16UL);
+	rcu_barrier();
+
+	radix_tree_split(&tree, 0, 0);
+
+	radix_tree_for_each_slot(slot, &tree, &iter, 0) {
+		radix_tree_iter_replace(&tree, &iter, slot, (void *)0x12UL);
+	}
+
+	__radix_tree_lookup(&tree, 0, &node, NULL);
+	assert(node->exceptional == node->count);
+
+	item_kill_tree(&tree);
+}
+
+static void multiorder_join(void)
+{
+	int i, j, idx;
+
+	for (idx = 0; idx < 1024; idx = idx * 2 + 3) {
+		for (i = 1; i < 15; i++) {
+			for (j = 0; j < i; j++) {
+				multiorder_join1(idx, i, j);
+			}
+		}
+	}
+
+	for (i = 1; i < 15; i++) {
+		for (j = 0; j < i; j++) {
+			multiorder_join2(i, j);
+		}
+	}
+
+	for (i = 3; i < 10; i++) {
+		multiorder_join3(i);
+	}
+}
+
+static void check_mem(unsigned old_order, unsigned new_order, unsigned alloc)
+{
+	struct radix_tree_preload *rtp = &radix_tree_preloads;
+	if (rtp->nr != 0)
+		printv(2, "split(%u %u) remaining %u\n", old_order, new_order,
+							rtp->nr);
+	/*
+	 * Can't check for equality here as some nodes may have been
+	 * RCU-freed while we ran.  But we should never finish with more
+	 * nodes allocated since they should have all been preloaded.
+	 */
+	if (nr_allocated > alloc)
+		printv(2, "split(%u %u) allocated %u %u\n", old_order, new_order,
+							alloc, nr_allocated);
+}
+
+static void __multiorder_split(int old_order, int new_order)
+{
+	RADIX_TREE(tree, GFP_ATOMIC);
+	void **slot;
+	struct radix_tree_iter iter;
+	unsigned alloc;
+	struct item *item;
+
+	radix_tree_preload(GFP_KERNEL);
+	assert(item_insert_order(&tree, 0, old_order) == 0);
+	radix_tree_preload_end();
+
+	/* Wipe out the preloaded cache or it'll confuse check_mem() */
+	radix_tree_cpu_dead(0);
+
+	item = radix_tree_tag_set(&tree, 0, 2);
+
+	radix_tree_split_preload(old_order, new_order, GFP_KERNEL);
+	alloc = nr_allocated;
+	radix_tree_split(&tree, 0, new_order);
+	check_mem(old_order, new_order, alloc);
+	radix_tree_for_each_slot(slot, &tree, &iter, 0) {
+		radix_tree_iter_replace(&tree, &iter, slot,
+					item_create(iter.index, new_order));
+	}
+	radix_tree_preload_end();
+
+	item_kill_tree(&tree);
+	free(item);
+}
+
+static void __multiorder_split2(int old_order, int new_order)
+{
+	RADIX_TREE(tree, GFP_KERNEL);
+	void **slot;
+	struct radix_tree_iter iter;
+	struct radix_tree_node *node;
+	void *item;
+
+	__radix_tree_insert(&tree, 0, old_order, (void *)0x12);
+
+	item = __radix_tree_lookup(&tree, 0, &node, NULL);
+	assert(item == (void *)0x12);
+	assert(node->exceptional > 0);
+
+	radix_tree_split(&tree, 0, new_order);
+	radix_tree_for_each_slot(slot, &tree, &iter, 0) {
+		radix_tree_iter_replace(&tree, &iter, slot,
+					item_create(iter.index, new_order));
+	}
+
+	item = __radix_tree_lookup(&tree, 0, &node, NULL);
+	assert(item != (void *)0x12);
+	assert(node->exceptional == 0);
+
+	item_kill_tree(&tree);
+}
+
+static void __multiorder_split3(int old_order, int new_order)
+{
+	RADIX_TREE(tree, GFP_KERNEL);
+	void **slot;
+	struct radix_tree_iter iter;
+	struct radix_tree_node *node;
+	void *item;
+
+	__radix_tree_insert(&tree, 0, old_order, (void *)0x12);
+
+	item = __radix_tree_lookup(&tree, 0, &node, NULL);
+	assert(item == (void *)0x12);
+	assert(node->exceptional > 0);
+
+	radix_tree_split(&tree, 0, new_order);
+	radix_tree_for_each_slot(slot, &tree, &iter, 0) {
+		radix_tree_iter_replace(&tree, &iter, slot, (void *)0x16);
+	}
+
+	item = __radix_tree_lookup(&tree, 0, &node, NULL);
+	assert(item == (void *)0x16);
+	assert(node->exceptional > 0);
+
+	item_kill_tree(&tree);
+
+	__radix_tree_insert(&tree, 0, old_order, (void *)0x12);
+
+	item = __radix_tree_lookup(&tree, 0, &node, NULL);
+	assert(item == (void *)0x12);
+	assert(node->exceptional > 0);
+
+	radix_tree_split(&tree, 0, new_order);
+	radix_tree_for_each_slot(slot, &tree, &iter, 0) {
+		if (iter.index == (1 << new_order))
+			radix_tree_iter_replace(&tree, &iter, slot,
+						(void *)0x16);
+		else
+			radix_tree_iter_replace(&tree, &iter, slot, NULL);
+	}
+
+	item = __radix_tree_lookup(&tree, 1 << new_order, &node, NULL);
+	assert(item == (void *)0x16);
+	assert(node->count == node->exceptional);
+	do {
+		node = node->parent;
+		if (!node)
+			break;
+		assert(node->count == 1);
+		assert(node->exceptional == 0);
+	} while (1);
+
+	item_kill_tree(&tree);
+}
+
+static void multiorder_split(void)
+{
+	int i, j;
+
+	for (i = 3; i < 11; i++)
+		for (j = 0; j < i; j++) {
+			__multiorder_split(i, j);
+			__multiorder_split2(i, j);
+			__multiorder_split3(i, j);
+		}
+}
+
+static void multiorder_account(void)
+{
+	RADIX_TREE(tree, GFP_KERNEL);
+	struct radix_tree_node *node;
+	void **slot;
+
+	item_insert_order(&tree, 0, 5);
+
+	__radix_tree_insert(&tree, 1 << 5, 5, (void *)0x12);
+	__radix_tree_lookup(&tree, 0, &node, NULL);
+	assert(node->count == node->exceptional * 2);
+	radix_tree_delete(&tree, 1 << 5);
+	assert(node->exceptional == 0);
+
+	__radix_tree_insert(&tree, 1 << 5, 5, (void *)0x12);
+	__radix_tree_lookup(&tree, 1 << 5, &node, &slot);
+	assert(node->count == node->exceptional * 2);
+	__radix_tree_replace(&tree, node, slot, NULL, NULL);
+	assert(node->exceptional == 0);
+
+	item_kill_tree(&tree);
+}
+
+bool stop_iteration = false;
+
+static void *creator_func(void *ptr)
+{
+	/* 'order' is set up to ensure we have sibling entries */
+	unsigned int order = RADIX_TREE_MAP_SHIFT - 1;
+	struct radix_tree_root *tree = ptr;
+	int i;
+
+	for (i = 0; i < 10000; i++) {
+		item_insert_order(tree, 0, order);
+		item_delete_rcu(tree, 0);
+	}
+
+	stop_iteration = true;
+	return NULL;
+}
+
+static void *iterator_func(void *ptr)
+{
+	struct radix_tree_root *tree = ptr;
+	struct radix_tree_iter iter;
+	struct item *item;
+	void **slot;
+
+	while (!stop_iteration) {
+		rcu_read_lock();
+		radix_tree_for_each_slot(slot, tree, &iter, 0) {
+			item = radix_tree_deref_slot(slot);
+
+			if (!item)
+				continue;
+			if (radix_tree_deref_retry(item)) {
+				slot = radix_tree_iter_retry(&iter);
+				continue;
+			}
+
+			item_sanity(item, iter.index);
+		}
+		rcu_read_unlock();
+	}
+	return NULL;
+}
+
+static void multiorder_iteration_race(void)
+{
+	const int num_threads = sysconf(_SC_NPROCESSORS_ONLN);
+	pthread_t worker_thread[num_threads];
+	RADIX_TREE(tree, GFP_KERNEL);
+	int i;
+
+	pthread_create(&worker_thread[0], NULL, &creator_func, &tree);
+	for (i = 1; i < num_threads; i++)
+		pthread_create(&worker_thread[i], NULL, &iterator_func, &tree);
+
+	for (i = 0; i < num_threads; i++)
+		pthread_join(worker_thread[i], NULL);
+
+	item_kill_tree(&tree);
+}
+
+void multiorder_checks(void)
+{
+	int i;
+
+	for (i = 0; i < 20; i++) {
+		multiorder_check(200, i);
+		multiorder_check(0, i);
+		multiorder_check((1UL << i) + 1, i);
+	}
+
+	for (i = 0; i < 15; i++)
+		multiorder_shrink((1UL << (i + RADIX_TREE_MAP_SHIFT)), i);
+
+	multiorder_insert_bug();
+	multiorder_tag_tests();
+	multiorder_iteration();
+	multiorder_tagged_iteration();
+	multiorder_join();
+	multiorder_split();
+	multiorder_account();
+	multiorder_iteration_race();
+
+	radix_tree_cpu_dead(0);
+}
+
+int __weak main(void)
+{
+	radix_tree_init();
+	multiorder_checks();
+	return 0;
+}