52 lines
1.2 KiB
C
52 lines
1.2 KiB
C
/*
|
|
* Huawei Kernel Harden, module randomize
|
|
*
|
|
* Copyright (c) 2016 Huawei.
|
|
*
|
|
* Authors:
|
|
* Wang Zhitong <wangzhitong1@huawei.com>
|
|
* Ma Yaohui <stesen.ma@huawei.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.
|
|
*/
|
|
|
|
#include <linux/bitops.h>
|
|
#include <linux/elf.h>
|
|
#include <linux/gfp.h>
|
|
#include <linux/kasan.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/moduleloader.h>
|
|
#include <linux/vmalloc.h>
|
|
#include <linux/random.h>
|
|
#include <asm/alternative.h>
|
|
#include <asm/insn.h>
|
|
#include <asm/sections.h>
|
|
|
|
static unsigned long module_load_offset;
|
|
static int randomize_modules = 1;
|
|
|
|
static DEFINE_MUTEX(module_kaslr_mutex);
|
|
|
|
static int __init parse_nokaslr(char *p)
|
|
{
|
|
randomize_modules = 0;
|
|
|
|
return 0;
|
|
}
|
|
early_param("nokaslr", parse_nokaslr);
|
|
|
|
unsigned long get_module_load_offset(void)
|
|
{
|
|
if (randomize_modules) {
|
|
mutex_lock(&module_kaslr_mutex);
|
|
if (module_load_offset == 0)
|
|
module_load_offset =
|
|
(get_random_int() % 1024 + 1) * PAGE_SIZE;
|
|
mutex_unlock(&module_kaslr_mutex);
|
|
}
|
|
|
|
return module_load_offset;
|
|
}
|