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
14 static 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
29 static 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
40 static void m_ex(void)
41 {
42 }
43
44 module_init(m_in);
45 module_exit(m_ex);
46 MODULE_AUTHOR("Matthew Wilcox <willy@infradead.org>");
47 MODULE_DESCRIPTION("Check that free_pages() doesn't leak memory");
48 MODULE_LICENSE("GPL");
49
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