mm/kmemleak-test.c

   1 /*
   2  * mm/kmemleak-test.c
   3  *
   4  * Copyright (C) 2008 ARM Limited
   5  * Written by Catalin Marinas <catalin.marinas@arm.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19  */
  20
  21 #define pr_fmt(fmt) "kmemleak: " fmt
  22
  23 #include <linux/init.h>
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/slab.h>
  27 #include <linux/vmalloc.h>
  28 #include <linux/list.h>
  29 #include <linux/percpu.h>
  30 #include <linux/fdtable.h>
  31
  32 #include <linux/kmemleak.h>
  33
  34 struct test_node {
  35         long header[25];
  36         struct list_head list;
  37         long footer[25];
  38 };
  39
  40 static LIST_HEAD(test_list);
  41 static DEFINE_PER_CPU(void *, kmemleak_test_pointer);
  42
  43 /*
  44  * Some very simple testing. This function needs to be extended for
  45  * proper testing.
  46  */
  47 static int __init kmemleak_test_init(void)
  48 {
  49         struct test_node *elem;
  50         int i;
  51
  52         printk(KERN_INFO "Kmemleak testing\n");
  53
  54         /* make some orphan objects */
  55         pr_info("kmalloc(32) = %p\n", kmalloc(32, GFP_KERNEL));
  56         pr_info("kmalloc(32) = %p\n", kmalloc(32, GFP_KERNEL));
  57         pr_info("kmalloc(1024) = %p\n", kmalloc(1024, GFP_KERNEL));
  58         pr_info("kmalloc(1024) = %p\n", kmalloc(1024, GFP_KERNEL));
  59         pr_info("kmalloc(2048) = %p\n", kmalloc(2048, GFP_KERNEL));
  60         pr_info("kmalloc(2048) = %p\n", kmalloc(2048, GFP_KERNEL));
  61         pr_info("kmalloc(4096) = %p\n", kmalloc(4096, GFP_KERNEL));
  62         pr_info("kmalloc(4096) = %p\n", kmalloc(4096, GFP_KERNEL));
  63 #ifndef CONFIG_MODULES
  64         pr_info("kmem_cache_alloc(files_cachep) = %p\n",
  65                 kmem_cache_alloc(files_cachep, GFP_KERNEL));
  66         pr_info("kmem_cache_alloc(files_cachep) = %p\n",
  67                 kmem_cache_alloc(files_cachep, GFP_KERNEL));
  68 #endif
  69         pr_info("vmalloc(64) = %p\n", vmalloc(64));
  70         pr_info("vmalloc(64) = %p\n", vmalloc(64));
  71         pr_info("vmalloc(64) = %p\n", vmalloc(64));
  72         pr_info("vmalloc(64) = %p\n", vmalloc(64));
  73         pr_info("vmalloc(64) = %p\n", vmalloc(64));
  74
  75         /*
  76          * Add elements to a list. They should only appear as orphan
  77          * after the module is removed.
  78          */
  79         for (i = 0; i < 10; i++) {
  80                 elem = kzalloc(sizeof(*elem), GFP_KERNEL);
  81                 pr_info("kzalloc(sizeof(*elem)) = %p\n", elem);
  82                 if (!elem)
  83                         return -ENOMEM;
  84                 INIT_LIST_HEAD(&elem->list);
  85                 list_add_tail(&elem->list, &test_list);
  86         }
  87
  88         for_each_possible_cpu(i) {
  89                 per_cpu(kmemleak_test_pointer, i) = kmalloc(129, GFP_KERNEL);
  90                 pr_info("kmalloc(129) = %p\n",
  91                         per_cpu(kmemleak_test_pointer, i));
  92         }
  93
  94         return 0;
  95 }
  96 module_init(kmemleak_test_init);
  97
  98 static void __exit kmemleak_test_exit(void)
  99 {
 100         struct test_node *elem, *tmp;
 101
 102         /*
 103          * Remove the list elements without actually freeing the
 104          * memory.
 105          */
 106         list_for_each_entry_safe(elem, tmp, &test_list, list)
 107                 list_del(&elem->list);
 108 }
 109 module_exit(kmemleak_test_exit);
 110
 111 MODULE_LICENSE("GPL");