// 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((void *)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");