mm/kmemleak-test.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * mm/kmemleak-test.c
   4  *
   5  * Copyright (C) 2008 ARM Limited
   6  * Written by Catalin Marinas <catalin.marinas@arm.com>
   7  */
   8
   9 #define pr_fmt(fmt) "kmemleak: " fmt
  10
  11 #include <linux/init.h>
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/slab.h>
  15 #include <linux/vmalloc.h>
  16 #include <linux/list.h>
  17 #include <linux/percpu.h>
  18 #include <linux/fdtable.h>
  19
  20 #include <linux/kmemleak.h>
  21
  22 struct test_node {
  23         long header[25];
  24         struct list_head list;
  25         long footer[25];
  26 };
  27
  28 static LIST_HEAD(test_list);
  29 static DEFINE_PER_CPU(void *, kmemleak_test_pointer);
  30
  31 /*
  32  * Some very simple testing. This function needs to be extended for
  33  * proper testing.
  34  */
  35 static int __init kmemleak_test_init(void)
  36 {
  37         struct test_node *elem;
  38         int i;
  39
  40         pr_info("Kmemleak testing\n");
  41
  42         /* make some orphan objects */
  43         pr_info("kmalloc(32) = %p\n", kmalloc(32, GFP_KERNEL));
  44         pr_info("kmalloc(32) = %p\n", kmalloc(32, GFP_KERNEL));
  45         pr_info("kmalloc(1024) = %p\n", kmalloc(1024, GFP_KERNEL));
  46         pr_info("kmalloc(1024) = %p\n", kmalloc(1024, GFP_KERNEL));
  47         pr_info("kmalloc(2048) = %p\n", kmalloc(2048, GFP_KERNEL));
  48         pr_info("kmalloc(2048) = %p\n", kmalloc(2048, GFP_KERNEL));
  49         pr_info("kmalloc(4096) = %p\n", kmalloc(4096, GFP_KERNEL));
  50         pr_info("kmalloc(4096) = %p\n", kmalloc(4096, GFP_KERNEL));
  51 #ifndef CONFIG_MODULES
  52         pr_info("kmem_cache_alloc(files_cachep) = %p\n",
  53                 kmem_cache_alloc(files_cachep, GFP_KERNEL));
  54         pr_info("kmem_cache_alloc(files_cachep) = %p\n",
  55                 kmem_cache_alloc(files_cachep, GFP_KERNEL));
  56 #endif
  57         pr_info("vmalloc(64) = %p\n", vmalloc(64));
  58         pr_info("vmalloc(64) = %p\n", vmalloc(64));
  59         pr_info("vmalloc(64) = %p\n", vmalloc(64));
  60         pr_info("vmalloc(64) = %p\n", vmalloc(64));
  61         pr_info("vmalloc(64) = %p\n", vmalloc(64));
  62
  63         /*
  64          * Add elements to a list. They should only appear as orphan
  65          * after the module is removed.
  66          */
  67         for (i = 0; i < 10; i++) {
  68                 elem = kzalloc(sizeof(*elem), GFP_KERNEL);
  69                 pr_info("kzalloc(sizeof(*elem)) = %p\n", elem);
  70                 if (!elem)
  71                         return -ENOMEM;
  72                 INIT_LIST_HEAD(&elem->list);
  73                 list_add_tail(&elem->list, &test_list);
  74         }
  75
  76         for_each_possible_cpu(i) {
  77                 per_cpu(kmemleak_test_pointer, i) = kmalloc(129, GFP_KERNEL);
  78                 pr_info("kmalloc(129) = %p\n",
  79                         per_cpu(kmemleak_test_pointer, i));
  80         }
  81
  82         return 0;
  83 }
  84 module_init(kmemleak_test_init);
  85
  86 static void __exit kmemleak_test_exit(void)
  87 {
  88         struct test_node *elem, *tmp;
  89
  90         /*
  91          * Remove the list elements without actually freeing the
  92          * memory.
  93          */
  94         list_for_each_entry_safe(elem, tmp, &test_list, list)
  95                 list_del(&elem->list);
  96 }
  97 module_exit(kmemleak_test_exit);
  98
  99 MODULE_LICENSE("GPL");