mirror of
git://projects.qi-hardware.com/openwrt-xburst.git
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1a29ef8e97
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@19815 3c298f89-4303-0410-b956-a3cf2f4a3e73
110 lines
3.2 KiB
C
110 lines
3.2 KiB
C
/*
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* arch/ubicom32/include/asm/uaccess.c
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* User space memory access functions for Ubicom32 architecture.
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*
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* (C) Copyright 2009, Ubicom, Inc.
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*
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* This file is part of the Ubicom32 Linux Kernel Port.
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*
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* The Ubicom32 Linux Kernel Port is free software: you can redistribute
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* it and/or modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, either version 2 of the
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* License, or (at your option) any later version.
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*
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* The Ubicom32 Linux Kernel Port is distributed in the hope that it
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* will be useful, but WITHOUT ANY WARRANTY; without even the implied
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* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
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* the GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with the Ubicom32 Linux Kernel Port. If not,
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* see <http://www.gnu.org/licenses/>.
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*
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* Ubicom32 implementation derived from (with many thanks):
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* arch/m68knommu
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* arch/blackfin
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* arch/parisc
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*/
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/string.h>
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#include <linux/module.h>
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#include <asm/segment.h>
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#include <asm/uaccess.h>
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extern int _stext, _etext, _sdata, _edata, _sbss, _ebss, _end;
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/*
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* __access_ok()
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* Check that the address is in the current processes.
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*
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* NOTE: The kernel uses "pretend" user addresses that wind
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* up calling access_ok() so this approach has only marginal
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* value because you wind up with lots of false positives.
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*/
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int __access_ok(unsigned long addr, unsigned long size)
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{
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// struct vm_area_struct *vma;
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/*
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* Don't do anything if we are not a running system yet.
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*/
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if (system_state != SYSTEM_RUNNING) {
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return 1;
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}
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/*
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* It appears that Linux will call this function even when we are not
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* in the context of a user space application that has a VM address
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* space. So we must check that current and mm are valid before
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* performing the check.
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*/
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if ((!current) || (!current->mm)) {
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return 1;
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}
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/*
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* We perform some basic checks on the address to ensure that it
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* is at least within the range of DRAM.
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*/
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if ((addr < (int)&_etext) || (addr > memory_end)) {
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printk(KERN_WARNING "pid=%d[%s]: range [%lx - %lx] not in memory area: [%lx - %lx]\n",
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current->pid, current->comm,
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addr, addr + size,
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memory_start, memory_end);
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return 0;
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}
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/*
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* For nommu Linux we can check this by looking at the allowed
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* memory map for the process.
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*
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* TODO: Since the kernel passes addresses in it's own space as though
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* they were user address, we can not validate the addresses this way.
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*/
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#if 0
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if (!down_read_trylock(¤t->mm->mmap_sem)) {
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return 1;
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}
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vma = find_vma(current->mm, addr);
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if (!vma) {
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up_read(¤t->mm->mmap_sem);
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printk(KERN_WARNING "pid=%d[%s]: possible invalid acesss on range: [%lx - %lx]\n",
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current->pid, current->comm, addr, addr + size);
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return 1;
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}
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if ((addr + size) > vma->vm_end) {
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up_read(¤t->mm->mmap_sem);
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printk(KERN_WARNING "pid=%d[%s]: possible invalid length on range: [%lx - %lx]\n",
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current->pid, current->comm, addr, addr + size);
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return 1;
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}
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up_read(¤t->mm->mmap_sem);
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#endif
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return 1;
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}
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EXPORT_SYMBOL(__access_ok);
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