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 #include <linux/gfp.h>
9 #include <linux/mm.h>
10 #include <linux/module.h>
11 
test_free_pages(gfp_t gfp)12 static void test_free_pages(gfp_t gfp)
13 {
14 	unsigned int i;
15 
16 	for (i = 0; i < 1000 * 1000; i++) {
17 		unsigned long addr = __get_free_pages(gfp, 3);
18 		struct page *page = virt_to_page(addr);
19 
20 		/* Simulate page cache getting a speculative reference */
21 		get_page(page);
22 		free_pages(addr, 3);
23 		put_page(page);
24 	}
25 }
26 
m_in(void)27 static int m_in(void)
28 {
29 	test_free_pages(GFP_KERNEL);
30 	test_free_pages(GFP_KERNEL | __GFP_COMP);
31 
32 	return 0;
33 }
34 
m_ex(void)35 static void m_ex(void)
36 {
37 }
38 
39 module_init(m_in);
40 module_exit(m_ex);
41 MODULE_AUTHOR("Matthew Wilcox <willy@infradead.org>");
42 MODULE_LICENSE("GPL");
43