1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * test_free_pages.c: Check that free_pages() doesn't leak memory
4 * Copyright (c) 2020 Oracle
5 * Author: Matthew Wilcox <willy@infradead.org>
6 */
7
8#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
9
10#include <linux/gfp.h>
11#include <linux/mm.h>
12#include <linux/module.h>
13
14static void test_free_pages(gfp_t gfp)
15{
16	unsigned int i;
17
18	for (i = 0; i < 1000 * 1000; i++) {
19		unsigned long addr = __get_free_pages(gfp, 3);
20		struct page *page = virt_to_page((void *)addr);
21
22		/* Simulate page cache getting a speculative reference */
23		get_page(page);
24		free_pages(addr, 3);
25		put_page(page);
26	}
27}
28
29static int m_in(void)
30{
31	pr_info("Testing with GFP_KERNEL\n");
32	test_free_pages(GFP_KERNEL);
33	pr_info("Testing with GFP_KERNEL | __GFP_COMP\n");
34	test_free_pages(GFP_KERNEL | __GFP_COMP);
35	pr_info("Test completed\n");
36
37	return 0;
38}
39
40static void m_ex(void)
41{
42}
43
44module_init(m_in);
45module_exit(m_ex);
46MODULE_AUTHOR("Matthew Wilcox <willy@infradead.org>");
47MODULE_LICENSE("GPL");
48