Revision 15cf17d26e08ee95c2e392a3a71f55d32e99e971 authored by Konstantin Khlebnikov on 08 March 2013, 20:43:36 UTC, committed by Linus Torvalds on 08 March 2013, 23:05:34 UTC
Fix a warning from lockdep caused by calling cancel_work_sync() for uninitialized struct work. This path has been triggered by destructon kmem-cache hierarchy via destroying its root kmem-cache. cache ffff88003c072d80 obj ffff88003b410000 cache ffff88003c072d80 obj ffff88003b924000 cache ffff88003c20bd40 INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. Pid: 2825, comm: insmod Tainted: G O 3.9.0-rc1-next-20130307+ #611 Call Trace: __lock_acquire+0x16a2/0x1cb0 lock_acquire+0x8a/0x120 flush_work+0x38/0x2a0 __cancel_work_timer+0x89/0xf0 cancel_work_sync+0xb/0x10 kmem_cache_destroy_memcg_children+0x81/0xb0 kmem_cache_destroy+0xf/0xe0 init_module+0xcb/0x1000 [kmem_test] do_one_initcall+0x11a/0x170 load_module+0x19b0/0x2320 SyS_init_module+0xc6/0xf0 system_call_fastpath+0x16/0x1b Example module to demonstrate: #include <linux/module.h> #include <linux/slab.h> #include <linux/mm.h> #include <linux/workqueue.h> int __init mod_init(void) { int size = 256; struct kmem_cache *cache; void *obj; struct page *page; cache = kmem_cache_create("kmem_cache_test", size, size, 0, NULL); if (!cache) return -ENOMEM; printk("cache %p\n", cache); obj = kmem_cache_alloc(cache, GFP_KERNEL); if (obj) { page = virt_to_head_page(obj); printk("obj %p cache %p\n", obj, page->slab_cache); kmem_cache_free(cache, obj); } flush_scheduled_work(); obj = kmem_cache_alloc(cache, GFP_KERNEL); if (obj) { page = virt_to_head_page(obj); printk("obj %p cache %p\n", obj, page->slab_cache); kmem_cache_free(cache, obj); } kmem_cache_destroy(cache); return -EBUSY; } module_init(mod_init); MODULE_LICENSE("GPL"); Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Glauber Costa <glommer@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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kmemleak-test.c
/*
* mm/kmemleak-test.c
*
* Copyright (C) 2008 ARM Limited
* Written by Catalin Marinas <catalin.marinas@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/list.h>
#include <linux/percpu.h>
#include <linux/fdtable.h>
#include <linux/kmemleak.h>
struct test_node {
long header[25];
struct list_head list;
long footer[25];
};
static LIST_HEAD(test_list);
static DEFINE_PER_CPU(void *, kmemleak_test_pointer);
/*
* Some very simple testing. This function needs to be extended for
* proper testing.
*/
static int __init kmemleak_test_init(void)
{
struct test_node *elem;
int i;
printk(KERN_INFO "Kmemleak testing\n");
/* make some orphan objects */
pr_info("kmemleak: kmalloc(32) = %p\n", kmalloc(32, GFP_KERNEL));
pr_info("kmemleak: kmalloc(32) = %p\n", kmalloc(32, GFP_KERNEL));
pr_info("kmemleak: kmalloc(1024) = %p\n", kmalloc(1024, GFP_KERNEL));
pr_info("kmemleak: kmalloc(1024) = %p\n", kmalloc(1024, GFP_KERNEL));
pr_info("kmemleak: kmalloc(2048) = %p\n", kmalloc(2048, GFP_KERNEL));
pr_info("kmemleak: kmalloc(2048) = %p\n", kmalloc(2048, GFP_KERNEL));
pr_info("kmemleak: kmalloc(4096) = %p\n", kmalloc(4096, GFP_KERNEL));
pr_info("kmemleak: kmalloc(4096) = %p\n", kmalloc(4096, GFP_KERNEL));
#ifndef CONFIG_MODULES
pr_info("kmemleak: kmem_cache_alloc(files_cachep) = %p\n",
kmem_cache_alloc(files_cachep, GFP_KERNEL));
pr_info("kmemleak: kmem_cache_alloc(files_cachep) = %p\n",
kmem_cache_alloc(files_cachep, GFP_KERNEL));
#endif
pr_info("kmemleak: vmalloc(64) = %p\n", vmalloc(64));
pr_info("kmemleak: vmalloc(64) = %p\n", vmalloc(64));
pr_info("kmemleak: vmalloc(64) = %p\n", vmalloc(64));
pr_info("kmemleak: vmalloc(64) = %p\n", vmalloc(64));
pr_info("kmemleak: vmalloc(64) = %p\n", vmalloc(64));
/*
* Add elements to a list. They should only appear as orphan
* after the module is removed.
*/
for (i = 0; i < 10; i++) {
elem = kzalloc(sizeof(*elem), GFP_KERNEL);
pr_info("kmemleak: kzalloc(sizeof(*elem)) = %p\n", elem);
if (!elem)
return -ENOMEM;
INIT_LIST_HEAD(&elem->list);
list_add_tail(&elem->list, &test_list);
}
for_each_possible_cpu(i) {
per_cpu(kmemleak_test_pointer, i) = kmalloc(129, GFP_KERNEL);
pr_info("kmemleak: kmalloc(129) = %p\n",
per_cpu(kmemleak_test_pointer, i));
}
return 0;
}
module_init(kmemleak_test_init);
static void __exit kmemleak_test_exit(void)
{
struct test_node *elem, *tmp;
/*
* Remove the list elements without actually freeing the
* memory.
*/
list_for_each_entry_safe(elem, tmp, &test_list, list)
list_del(&elem->list);
}
module_exit(kmemleak_test_exit);
MODULE_LICENSE("GPL");
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