[mirror_ubuntu-jammy-kernel.git] / lib / test_free_pages.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * test_free_pages.c: Check that free_pages() doesn't leak memory
 * Copyright (c) 2020 Oracle
 * Author: Matthew Wilcox <willy@infradead.org>
 */

#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt

#include <linux/gfp.h>
#include <linux/mm.h>
#include <linux/module.h>

static void test_free_pages(gfp_t gfp)
{
	unsigned int i;

	for (i = 0; i < 1000 * 1000; i++) {
		unsigned long addr = __get_free_pages(gfp, 3);
		struct page *page = virt_to_page(addr);

		/* Simulate page cache getting a speculative reference */
		get_page(page);
		free_pages(addr, 3);
		put_page(page);
	}
}

static int m_in(void)
{
	pr_info("Testing with GFP_KERNEL\n");
	test_free_pages(GFP_KERNEL);
	pr_info("Testing with GFP_KERNEL | __GFP_COMP\n");
	test_free_pages(GFP_KERNEL | __GFP_COMP);
	pr_info("Test completed\n");

	return 0;
}

static void m_ex(void)
{
}

module_init(m_in);
module_exit(m_ex);
MODULE_AUTHOR("Matthew Wilcox <willy@infradead.org>");
MODULE_LICENSE("GPL");
Commit	Line	Data
e320d301 MWO	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
0ae446e4 GU	8	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
0ae446e4 GU	9
e320d301 MWO	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(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	{
0ae446e4	31	pr_info("Testing with GFP_KERNEL\n");
e320d301	32	test_free_pages(GFP_KERNEL);
0ae446e4	33	pr_info("Testing with GFP_KERNEL \| __GFP_COMP\n");
e320d301	34	test_free_pages(GFP_KERNEL \| __GFP_COMP);
0ae446e4	35	pr_info("Test completed\n");
e320d301 MWO	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_LICENSE("GPL");