[linux-2.6-block.git] / arch / arm / mm / pageattr.c

/*
 * Copyright (c) 2014, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only 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.
 */
#include <linux/mm.h>
#include <linux/module.h>

#include <asm/pgtable.h>
#include <asm/tlbflush.h>

struct page_change_data {
	pgprot_t set_mask;
	pgprot_t clear_mask;
};

static int change_page_range(pte_t *ptep, pgtable_t token, unsigned long addr,
			void *data)
{
	struct page_change_data *cdata = data;
	pte_t pte = *ptep;

	pte = clear_pte_bit(pte, cdata->clear_mask);
	pte = set_pte_bit(pte, cdata->set_mask);

	set_pte_ext(ptep, pte, 0);
	return 0;
}

static int change_memory_common(unsigned long addr, int numpages,
				pgprot_t set_mask, pgprot_t clear_mask)
{
	unsigned long start = addr;
	unsigned long size = PAGE_SIZE*numpages;
	unsigned long end = start + size;
	int ret;
	struct page_change_data data;

	if (!IS_ALIGNED(addr, PAGE_SIZE)) {
		start &= PAGE_MASK;
		end = start + size;
		WARN_ON_ONCE(1);
	}

	if (!numpages)
		return 0;

	if (start < MODULES_VADDR || start >= MODULES_END)
		return -EINVAL;

	if (end < MODULES_VADDR || start >= MODULES_END)
		return -EINVAL;

	data.set_mask = set_mask;
	data.clear_mask = clear_mask;

	ret = apply_to_page_range(&init_mm, start, size, change_page_range,
					&data);

	flush_tlb_kernel_range(start, end);
	return ret;
}

int set_memory_ro(unsigned long addr, int numpages)
{
	return change_memory_common(addr, numpages,
					__pgprot(L_PTE_RDONLY),
					__pgprot(0));
}

int set_memory_rw(unsigned long addr, int numpages)
{
	return change_memory_common(addr, numpages,
					__pgprot(0),
					__pgprot(L_PTE_RDONLY));
}

int set_memory_nx(unsigned long addr, int numpages)
{
	return change_memory_common(addr, numpages,
					__pgprot(L_PTE_XN),
					__pgprot(0));
}

int set_memory_x(unsigned long addr, int numpages)
{
	return change_memory_common(addr, numpages,
					__pgprot(0),
					__pgprot(L_PTE_XN));
}
Commit	Line	Data
4e802cfd JL	1	/*
	2	* Copyright (c) 2014, The Linux Foundation. All rights reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 and
	6	* only version 2 as published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope that it will be useful,
	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	11	* GNU General Public License for more details.
	12	*/
	13	#include <linux/mm.h>
	14	#include <linux/module.h>
	15
	16	#include <asm/pgtable.h>
	17	#include <asm/tlbflush.h>
	18
	19	struct page_change_data {
	20	pgprot_t set_mask;
	21	pgprot_t clear_mask;
	22	};
	23
	24	static int change_page_range(pte_t *ptep, pgtable_t token, unsigned long addr,
	25	void *data)
	26	{
	27	struct page_change_data *cdata = data;
	28	pte_t pte = *ptep;
	29
	30	pte = clear_pte_bit(pte, cdata->clear_mask);
	31	pte = set_pte_bit(pte, cdata->set_mask);
	32
	33	set_pte_ext(ptep, pte, 0);
	34	return 0;
	35	}
	36
	37	static int change_memory_common(unsigned long addr, int numpages,
	38	pgprot_t set_mask, pgprot_t clear_mask)
	39	{
	40	unsigned long start = addr;
	41	unsigned long size = PAGE_SIZE*numpages;
	42	unsigned long end = start + size;
	43	int ret;
	44	struct page_change_data data;
	45
	46	if (!IS_ALIGNED(addr, PAGE_SIZE)) {
	47	start &= PAGE_MASK;
	48	end = start + size;
	49	WARN_ON_ONCE(1);
	50	}
	51
f474c8c8 MP	52	if (!numpages)
	53	return 0;
	54
f2ca09f3 LA	55	if (start < MODULES_VADDR \|\| start >= MODULES_END)
	56	return -EINVAL;
	57
	58	if (end < MODULES_VADDR \|\| start >= MODULES_END)
4e802cfd JL	59	return -EINVAL;
	60
	61	data.set_mask = set_mask;
	62	data.clear_mask = clear_mask;
	63
	64	ret = apply_to_page_range(&init_mm, start, size, change_page_range,
	65	&data);
	66
	67	flush_tlb_kernel_range(start, end);
	68	return ret;
	69	}
	70
	71	int set_memory_ro(unsigned long addr, int numpages)
	72	{
	73	return change_memory_common(addr, numpages,
	74	__pgprot(L_PTE_RDONLY),
	75	__pgprot(0));
	76	}
	77
	78	int set_memory_rw(unsigned long addr, int numpages)
	79	{
	80	return change_memory_common(addr, numpages,
	81	__pgprot(0),
	82	__pgprot(L_PTE_RDONLY));
	83	}
	84
	85	int set_memory_nx(unsigned long addr, int numpages)
	86	{
	87	return change_memory_common(addr, numpages,
	88	__pgprot(L_PTE_XN),
	89	__pgprot(0));
	90	}
	91
	92	int set_memory_x(unsigned long addr, int numpages)
	93	{
	94	return change_memory_common(addr, numpages,
	95	__pgprot(0),
	96	__pgprot(L_PTE_XN));
	97	}