Revision aee636c4809fa54848ff07a899b326eb1f9987a2 authored by Eric Dumazet on 15 January 2014, 14:50:07 UTC, committed by David S. Miller on 16 January 2014, 01:02:08 UTC
At first Jakub Zawadzki noticed that some divisions by reciprocal_divide were not correct. (off by one in some cases) http://www.wireshark.org/~darkjames/reciprocal-buggy.c He could also show this with BPF: http://www.wireshark.org/~darkjames/set-and-dump-filter-k-bug.c The reciprocal divide in linux kernel is not generic enough, lets remove its use in BPF, as it is not worth the pain with current cpus. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Jakub Zawadzki <darkjames-ws@darkjames.pl> Cc: Mircea Gherzan <mgherzan@gmail.com> Cc: Daniel Borkmann <dxchgb@gmail.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Matt Evans <matt@ozlabs.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: David S. Miller <davem@davemloft.net>
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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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