summaryrefslogtreecommitdiffstats
path: root/tools/testing/radix-tree/iteration_check.c
blob: 238db187aa15bc348df5dd6da3c6ecce4ffbc999 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
/*
 * iteration_check.c: test races having to do with xarray iteration
 * Copyright (c) 2016 Intel Corporation
 * Author: Ross Zwisler <ross.zwisler@linux.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 <pthread.h>
#include "test.h"

#define NUM_THREADS	5
#define MAX_IDX		100
#define TAG		XA_MARK_0
#define NEW_TAG		XA_MARK_1

static pthread_t threads[NUM_THREADS];
static unsigned int seeds[3];
static DEFINE_XARRAY(array);
static bool test_complete;
static int max_order;

void my_item_insert(struct xarray *xa, unsigned long index)
{
	XA_STATE(xas, xa, index);
	struct item *item = item_create(index, 0);
	int order;

retry:
	xas_lock(&xas);
	for (order = max_order; order >= 0; order--) {
		xas_set_order(&xas, index, order);
		item->order = order;
		if (xas_find_conflict(&xas))
			continue;
		xas_store(&xas, item);
		xas_set_mark(&xas, TAG);
		break;
	}
	xas_unlock(&xas);
	if (xas_nomem(&xas, GFP_KERNEL))
		goto retry;
	if (order < 0)
		free(item);
}

/* relentlessly fill the array with tagged entries */
static void *add_entries_fn(void *arg)
{
	rcu_register_thread();

	while (!test_complete) {
		unsigned long pgoff;

		for (pgoff = 0; pgoff < MAX_IDX; pgoff++) {
			my_item_insert(&array, pgoff);
		}
	}

	rcu_unregister_thread();

	return NULL;
}

/*
 * Iterate over tagged entries, retrying when we find ourselves in a deleted
 * node and randomly pausing the iteration.
 */
static void *tagged_iteration_fn(void *arg)
{
	XA_STATE(xas, &array, 0);
	void *entry;

	rcu_register_thread();

	while (!test_complete) {
		xas_set(&xas, 0);
		rcu_read_lock();
		xas_for_each_marked(&xas, entry, ULONG_MAX, TAG) {
			if (xas_retry(&xas, entry))
				continue;

			if (rand_r(&seeds[0]) % 50 == 0) {
				xas_pause(&xas);
				rcu_read_unlock();
				rcu_barrier();
				rcu_read_lock();
			}
		}
		rcu_read_unlock();
	}

	rcu_unregister_thread();

	return NULL;
}

/*
 * Iterate over the entries, retrying when we find ourselves in a deleted
 * node and randomly pausing the iteration.
 */
static void *untagged_iteration_fn(void *arg)
{
	XA_STATE(xas, &array, 0);
	void *entry;

	rcu_register_thread();

	while (!test_complete) {
		xas_set(&xas, 0);
		rcu_read_lock();
		xas_for_each(&xas, entry, ULONG_MAX) {
			if (xas_retry(&xas, entry))
				continue;

			if (rand_r(&seeds[1]) % 50 == 0) {
				xas_pause(&xas);
				rcu_read_unlock();
				rcu_barrier();
				rcu_read_lock();
			}
		}
		rcu_read_unlock();
	}

	rcu_unregister_thread();

	return NULL;
}

/*
 * Randomly remove entries to help induce retries in the
 * two iteration functions.
 */
static void *remove_entries_fn(void *arg)
{
	rcu_register_thread();

	while (!test_complete) {
		int pgoff;
		struct item *item;

		pgoff = rand_r(&seeds[2]) % MAX_IDX;

		item = xa_erase(&array, pgoff);
		if (item)
			item_free(item, pgoff);
	}

	rcu_unregister_thread();

	return NULL;
}

static void *tag_entries_fn(void *arg)
{
	rcu_register_thread();

	while (!test_complete) {
		tag_tagged_items(&array, 0, MAX_IDX, 10, TAG, NEW_TAG);
	}
	rcu_unregister_thread();
	return NULL;
}

/* This is a unit test for a bug found by the syzkaller tester */
void iteration_test(unsigned order, unsigned test_duration)
{
	int i;

	printv(1, "Running %siteration tests for %d seconds\n",
			order > 0 ? "multiorder " : "", test_duration);

	max_order = order;
	test_complete = false;

	for (i = 0; i < 3; i++)
		seeds[i] = rand();

	if (pthread_create(&threads[0], NULL, tagged_iteration_fn, NULL)) {
		perror("create tagged iteration thread");
		exit(1);
	}
	if (pthread_create(&threads[1], NULL, untagged_iteration_fn, NULL)) {
		perror("create untagged iteration thread");
		exit(1);
	}
	if (pthread_create(&threads[2], NULL, add_entries_fn, NULL)) {
		perror("create add entry thread");
		exit(1);
	}
	if (pthread_create(&threads[3], NULL, remove_entries_fn, NULL)) {
		perror("create remove entry thread");
		exit(1);
	}
	if (pthread_create(&threads[4], NULL, tag_entries_fn, NULL)) {
		perror("create tag entry thread");
		exit(1);
	}

	sleep(test_duration);
	test_complete = true;

	for (i = 0; i < NUM_THREADS; i++) {
		if (pthread_join(threads[i], NULL)) {
			perror("pthread_join");
			exit(1);
		}
	}

	item_kill_tree(&array);
}