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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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f2ca09f381
The set_memory_* functions currently only support module addresses. The addresses are validated using is_module_addr. That function is special though and relies on internal state in the module subsystem to work properly. At the time of module initialization and calling set_memory_*, it's too early for is_module_addr to work properly so it always returns false. Rather than be subject to the whims of the module state, just bounds check against the module virtual address range. Signed-off-by: Laura Abbott <lauraa@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
94 lines
2.2 KiB
C
94 lines
2.2 KiB
C
/*
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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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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 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;
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unsigned long size = PAGE_SIZE*numpages;
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unsigned long end = start + size;
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int ret;
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struct page_change_data data;
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if (!IS_ALIGNED(addr, PAGE_SIZE)) {
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start &= PAGE_MASK;
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end = start + size;
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WARN_ON_ONCE(1);
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}
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if (start < MODULES_VADDR || start >= MODULES_END)
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return -EINVAL;
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if (end < MODULES_VADDR || start >= MODULES_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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