lib/test_free_pages.c

   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
  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
  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
  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");