kmemleak-test.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * samples/kmemleak/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
 22struct test_node {
 23	long header[25];
 24	struct list_head list;
 25	long footer[25];
 26};
 27
 28static LIST_HEAD(test_list);
 29static 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 */
 35static int 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) = 0x%px\n", kmalloc(32, GFP_KERNEL));
 44	pr_info("kmalloc(32) = 0x%px\n", kmalloc(32, GFP_KERNEL));
 45	pr_info("kmalloc(1024) = 0x%px\n", kmalloc(1024, GFP_KERNEL));
 46	pr_info("kmalloc(1024) = 0x%px\n", kmalloc(1024, GFP_KERNEL));
 47	pr_info("kmalloc(2048) = 0x%px\n", kmalloc(2048, GFP_KERNEL));
 48	pr_info("kmalloc(2048) = 0x%px\n", kmalloc(2048, GFP_KERNEL));
 49	pr_info("kmalloc(4096) = 0x%px\n", kmalloc(4096, GFP_KERNEL));
 50	pr_info("kmalloc(4096) = 0x%px\n", kmalloc(4096, GFP_KERNEL));
 51#ifndef CONFIG_MODULES
 52	pr_info("kmem_cache_alloc(files_cachep) = 0x%px\n",
 53		kmem_cache_alloc(files_cachep, GFP_KERNEL));
 54	pr_info("kmem_cache_alloc(files_cachep) = 0x%px\n",
 55		kmem_cache_alloc(files_cachep, GFP_KERNEL));
 56#endif
 57	pr_info("vmalloc(64) = 0x%px\n", vmalloc(64));
 58	pr_info("vmalloc(64) = 0x%px\n", vmalloc(64));
 59	pr_info("vmalloc(64) = 0x%px\n", vmalloc(64));
 60	pr_info("vmalloc(64) = 0x%px\n", vmalloc(64));
 61	pr_info("vmalloc(64) = 0x%px\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)) = 0x%px\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) = 0x%px\n",
 79			per_cpu(kmemleak_test_pointer, i));
 80	}
 81
 82	pr_info("__alloc_percpu(64, 4) = 0x%px\n", __alloc_percpu(64, 4));
 83
 84	return 0;
 85}
 86module_init(kmemleak_test_init);
 87
 88static void __exit kmemleak_test_exit(void)
 89{
 90	struct test_node *elem, *tmp;
 91
 92	/*
 93	 * Remove the list elements without actually freeing the
 94	 * memory.
 95	 */
 96	list_for_each_entry_safe(elem, tmp, &test_list, list)
 97		list_del(&elem->list);
 98}
 99module_exit(kmemleak_test_exit);
100
101MODULE_DESCRIPTION("Sample module to leak memory for kmemleak testing");
102MODULE_LICENSE("GPL");