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 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 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 pr_info("__alloc_percpu(64, 4) = %p\n", __alloc_percpu(64, 4)); 83 84 return 0; 85 } 86 module_init(kmemleak_test_init); 87 88 static 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 } 99 module_exit(kmemleak_test_exit); 100 101 MODULE_DESCRIPTION("Sample module to leak memory for kmemleak testing"); 102 MODULE_LICENSE("GPL"); 103