100 lines
2.4 KiB
C
Executable file
100 lines
2.4 KiB
C
Executable file
/*
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* Copyright (c) 2014, The Linux Foundation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 and
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* only version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <asm/pgtable.h>
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#include <asm/tlbflush.h>
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#include <asm/set_memory.h>
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struct page_change_data {
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pgprot_t set_mask;
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pgprot_t clear_mask;
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};
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static int change_page_range(pte_t *ptep, pgtable_t token, unsigned long addr,
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void *data)
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{
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struct page_change_data *cdata = data;
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pte_t pte = *ptep;
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pte = clear_pte_bit(pte, cdata->clear_mask);
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pte = set_pte_bit(pte, cdata->set_mask);
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set_pte_ext(ptep, pte, 0);
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return 0;
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}
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static bool in_range(unsigned long start, unsigned long size,
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unsigned long range_start, unsigned long range_end)
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{
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return start >= range_start && start < range_end &&
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size <= range_end - start;
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}
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static int change_memory_common(unsigned long addr, int numpages,
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pgprot_t set_mask, pgprot_t clear_mask)
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{
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unsigned long start = addr & PAGE_MASK;
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unsigned long end = PAGE_ALIGN(addr) + numpages * PAGE_SIZE;
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unsigned long size = end - start;
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int ret;
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struct page_change_data data;
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WARN_ON_ONCE(start != addr);
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if (!size)
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return 0;
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if (!in_range(start, size, MODULES_VADDR, MODULES_END) &&
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!in_range(start, size, VMALLOC_START, VMALLOC_END))
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return -EINVAL;
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data.set_mask = set_mask;
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data.clear_mask = clear_mask;
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ret = apply_to_page_range(&init_mm, start, size, change_page_range,
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&data);
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flush_tlb_kernel_range(start, end);
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return ret;
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}
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int set_memory_ro(unsigned long addr, int numpages)
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{
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return change_memory_common(addr, numpages,
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__pgprot(L_PTE_RDONLY),
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__pgprot(0));
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}
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int set_memory_rw(unsigned long addr, int numpages)
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{
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return change_memory_common(addr, numpages,
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__pgprot(0),
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__pgprot(L_PTE_RDONLY));
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}
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int set_memory_nx(unsigned long addr, int numpages)
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{
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return change_memory_common(addr, numpages,
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__pgprot(L_PTE_XN),
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__pgprot(0));
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}
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int set_memory_x(unsigned long addr, int numpages)
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{
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return change_memory_common(addr, numpages,
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__pgprot(0),
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__pgprot(L_PTE_XN));
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}
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