[mirror_ubuntu-artful-kernel.git] / arch / x86 / mm / dump_pagetables.c

/*
 * Debug helper to dump the current kernel pagetables of the system
 * so that we can see what the various memory ranges are set to.
 *
 * (C) Copyright 2008 Intel Corporation
 *
 * Author: Arjan van de Ven <arjan@linux.intel.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; version 2
 * of the License.
 */

#include <linux/debugfs.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/seq_file.h>

#include <asm/pgtable.h>

/*
 * The dumper groups pagetable entries of the same type into one, and for
 * that it needs to keep some state when walking, and flush this state
 * when a "break" in the continuity is found.
 */
struct pg_state {
	int level;
	pgprot_t current_prot;
	unsigned long start_address;
	unsigned long current_address;
	const struct addr_marker *marker;
};

struct addr_marker {
	unsigned long start_address;
	const char *name;
};

/* Address space markers hints */
static struct addr_marker address_markers[] = {
	{ 0, "User Space" },
#ifdef CONFIG_X86_64
	{ 0x8000000000000000UL, "Kernel Space" },
	{ 0xffff810000000000UL, "Low Kernel Mapping" },
	{ VMALLOC_START,        "vmalloc() Area" },
	{ VMEMMAP_START,        "Vmemmap" },
	{ __START_KERNEL_map,   "High Kernel Mapping" },
	{ MODULES_VADDR,        "Modules" },
	{ MODULES_END,          "End Modules" },
#else
	{ PAGE_OFFSET,          "Kernel Mapping" },
	{ 0/* VMALLOC_START */, "vmalloc() Area" },
	{ 0/*VMALLOC_END*/,     "vmalloc() End" },
# ifdef CONFIG_HIGHMEM
	{ 0/*PKMAP_BASE*/,      "Persisent kmap() Area" },
# endif
	{ 0/*FIXADDR_START*/,   "Fixmap Area" },
#endif
	{ -1, NULL }		/* End of list */
};

/* Multipliers for offsets within the PTEs */
#define PTE_LEVEL_MULT (PAGE_SIZE)
#define PMD_LEVEL_MULT (PTRS_PER_PTE * PTE_LEVEL_MULT)
#define PUD_LEVEL_MULT (PTRS_PER_PMD * PMD_LEVEL_MULT)
#define PGD_LEVEL_MULT (PTRS_PER_PUD * PUD_LEVEL_MULT)

/*
 * Print a readable form of a pgprot_t to the seq_file
 */
static void printk_prot(struct seq_file *m, pgprot_t prot, int level)
{
	pgprotval_t pr = pgprot_val(prot);
	static const char * const level_name[] =
		{ "cr3", "pgd", "pud", "pmd", "pte" };

	if (!pgprot_val(prot)) {
		/* Not present */
		seq_printf(m, "                          ");
	} else {
		if (pr & _PAGE_USER)
			seq_printf(m, "USR ");
		else
			seq_printf(m, "    ");
		if (pr & _PAGE_RW)
			seq_printf(m, "RW ");
		else
			seq_printf(m, "ro ");
		if (pr & _PAGE_PWT)
			seq_printf(m, "PWT ");
		else
			seq_printf(m, "    ");
		if (pr & _PAGE_PCD)
			seq_printf(m, "PCD ");
		else
			seq_printf(m, "    ");

		/* Bit 9 has a different meaning on level 3 vs 4 */
		if (level <= 3) {
			if (pr & _PAGE_PSE)
				seq_printf(m, "PSE ");
			else
				seq_printf(m, "    ");
		} else {
			if (pr & _PAGE_PAT)
				seq_printf(m, "pat ");
			else
				seq_printf(m, "    ");
		}
		if (pr & _PAGE_GLOBAL)
			seq_printf(m, "GLB ");
		else
			seq_printf(m, "    ");
		if (pr & _PAGE_NX)
			seq_printf(m, "NX ");
		else
			seq_printf(m, "x  ");
	}
	seq_printf(m, "%s\n", level_name[level]);
}

/*
 * On 64 bits, sign-extend the 48 bit address to 64 bit
 */
static unsigned long normalize_addr(unsigned long u)
{
#ifdef CONFIG_X86_64
	return (signed long)(u << 16) >> 16;
#else
	return u;
#endif
}

/*
 * This function gets called on a break in a continuous series
 * of PTE entries; the next one is different so we need to
 * print what we collected so far.
 */
static void note_page(struct seq_file *m, struct pg_state *st,
		      pgprot_t new_prot, int level)
{
	pgprotval_t prot, cur;
	static const char units[] = "KMGTPE";

	/*
	 * If we have a "break" in the series, we need to flush the state that
	 * we have now. "break" is either changing perms, levels or
	 * address space marker.
	 */
	prot = pgprot_val(new_prot) & ~(PTE_MASK);
	cur = pgprot_val(st->current_prot) & ~(PTE_MASK);

	if (!st->level) {
		/* First entry */
		st->current_prot = new_prot;
		st->level = level;
		st->marker = address_markers;
		seq_printf(m, "---[ %s ]---\n", st->marker->name);
	} else if (prot != cur || level != st->level ||
		   st->current_address >= st->marker[1].start_address) {
		const char *unit = units;
		unsigned long delta;

		/*
		 * Now print the actual finished series
		 */
		seq_printf(m, "0x%p-0x%p   ",
			   (void *)st->start_address,
			   (void *)st->current_address);

		delta = (st->current_address - st->start_address) >> 10;
		while (!(delta & 1023) && unit[1]) {
			delta >>= 10;
			unit++;
		}
		seq_printf(m, "%9lu%c ", delta, *unit);
		printk_prot(m, st->current_prot, st->level);

		/*
		 * We print markers for special areas of address space,
		 * such as the start of vmalloc space etc.
		 * This helps in the interpretation.
		 */
		if (st->current_address >= st->marker[1].start_address) {
			st->marker++;
			seq_printf(m, "---[ %s ]---\n", st->marker->name);
		}

		st->start_address = st->current_address;
		st->current_prot = new_prot;
		st->level = level;
	}
}

static void walk_pte_level(struct seq_file *m, struct pg_state *st, pmd_t addr,
							unsigned long P)
{
	int i;
	pte_t *start;

	start = (pte_t *) pmd_page_vaddr(addr);
	for (i = 0; i < PTRS_PER_PTE; i++) {
		pgprot_t prot = pte_pgprot(*start);

		st->current_address = normalize_addr(P + i * PTE_LEVEL_MULT);
		note_page(m, st, prot, 4);
		start++;
	}
}

#if PTRS_PER_PMD > 1

static void walk_pmd_level(struct seq_file *m, struct pg_state *st, pud_t addr,
							unsigned long P)
{
	int i;
	pmd_t *start;

	start = (pmd_t *) pud_page_vaddr(addr);
	for (i = 0; i < PTRS_PER_PMD; i++) {
		st->current_address = normalize_addr(P + i * PMD_LEVEL_MULT);
		if (!pmd_none(*start)) {
			pgprotval_t prot = pmd_val(*start) & ~PTE_MASK;

			if (pmd_large(*start) || !pmd_present(*start))
				note_page(m, st, __pgprot(prot), 3);
			else
				walk_pte_level(m, st, *start,
					       P + i * PMD_LEVEL_MULT);
		} else
			note_page(m, st, __pgprot(0), 3);
		start++;
	}
}

#else
#define walk_pmd_level(m,s,a,p) walk_pte_level(m,s,__pmd(pud_val(a)),p)
#define pud_large(a) pmd_large(__pmd(pud_val(a)))
#define pud_none(a)  pmd_none(__pmd(pud_val(a)))
#endif

#if PTRS_PER_PUD > 1

static void walk_pud_level(struct seq_file *m, struct pg_state *st, pgd_t addr,
							unsigned long P)
{
	int i;
	pud_t *start;

	start = (pud_t *) pgd_page_vaddr(addr);

	for (i = 0; i < PTRS_PER_PUD; i++) {
		st->current_address = normalize_addr(P + i * PUD_LEVEL_MULT);
		if (!pud_none(*start)) {
			pgprotval_t prot = pud_val(*start) & ~PTE_MASK;

			if (pud_large(*start) || !pud_present(*start))
				note_page(m, st, __pgprot(prot), 2);
			else
				walk_pmd_level(m, st, *start,
					       P + i * PUD_LEVEL_MULT);
		} else
			note_page(m, st, __pgprot(0), 2);

		start++;
	}
}

#else
#define walk_pud_level(m,s,a,p) walk_pmd_level(m,s,__pud(pgd_val(a)),p)
#define pgd_large(a) pud_large(__pud(pgd_val(a)))
#define pgd_none(a)  pud_none(__pud(pgd_val(a)))
#endif

static void walk_pgd_level(struct seq_file *m)
{
#ifdef CONFIG_X86_64
	pgd_t *start = (pgd_t *) &init_level4_pgt;
#else
	pgd_t *start = swapper_pg_dir;
#endif
	int i;
	struct pg_state st;

	memset(&st, 0, sizeof(st));

	for (i = 0; i < PTRS_PER_PGD; i++) {
		st.current_address = normalize_addr(i * PGD_LEVEL_MULT);
		if (!pgd_none(*start)) {
			pgprotval_t prot = pgd_val(*start) & ~PTE_MASK;

			if (pgd_large(*start) || !pgd_present(*start))
				note_page(m, &st, __pgprot(prot), 1);
			else
				walk_pud_level(m, &st, *start,
					       i * PGD_LEVEL_MULT);
		} else
			note_page(m, &st, __pgprot(0), 1);

		start++;
	}

	/* Flush out the last page */
	st.current_address = normalize_addr(PTRS_PER_PGD*PGD_LEVEL_MULT);
	note_page(m, &st, __pgprot(0), 0);
}

static int ptdump_show(struct seq_file *m, void *v)
{
	walk_pgd_level(m);
	return 0;
}

static int ptdump_open(struct inode *inode, struct file *filp)
{
	return single_open(filp, ptdump_show, NULL);
}

static const struct file_operations ptdump_fops = {
	.open		= ptdump_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static int pt_dump_init(void)
{
	struct dentry *pe;

#ifdef CONFIG_X86_32
	/* Not a compile-time constant on x86-32 */
	address_markers[2].start_address = VMALLOC_START;
	address_markers[3].start_address = VMALLOC_END;
# ifdef CONFIG_HIGHMEM
	address_markers[4].start_address = PKMAP_BASE;
	address_markers[5].start_address = FIXADDR_START;
# else
	address_markers[4].start_address = FIXADDR_START;
# endif
#endif

	pe = debugfs_create_file("kernel_page_tables", 0600, NULL, NULL,
				 &ptdump_fops);
	if (!pe)
		return -ENOMEM;

	return 0;
}

__initcall(pt_dump_init);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");
MODULE_DESCRIPTION("Kernel debugging helper that dumps pagetables");
Commit	Line	Data
926e5392 AV	1	/*
	2	* Debug helper to dump the current kernel pagetables of the system
	3	* so that we can see what the various memory ranges are set to.
	4	*
	5	* (C) Copyright 2008 Intel Corporation
	6	*
	7	* Author: Arjan van de Ven <arjan@linux.intel.com>
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License
	11	* as published by the Free Software Foundation; version 2
	12	* of the License.
	13	*/
	14
fe770bf0 PA	15	#include <linux/debugfs.h>
fe770bf0 PA	16	#include <linux/mm.h>
926e5392 AV	17	#include <linux/module.h>
926e5392 AV	18	#include <linux/seq_file.h>
926e5392 AV	19
	20	#include <asm/pgtable.h>
	21
	22	/*
	23	* The dumper groups pagetable entries of the same type into one, and for
	24	* that it needs to keep some state when walking, and flush this state
	25	* when a "break" in the continuity is found.
	26	*/
	27	struct pg_state {
	28	int level;
	29	pgprot_t current_prot;
	30	unsigned long start_address;
	31	unsigned long current_address;
fe770bf0	32	const struct addr_marker *marker;
926e5392 AV	33	};
926e5392 AV	34
fe770bf0 PA	35	struct addr_marker {
	36	unsigned long start_address;
	37	const char *name;
	38	};
	39
	40	/* Address space markers hints */
	41	static struct addr_marker address_markers[] = {
	42	{ 0, "User Space" },
	43	#ifdef CONFIG_X86_64
	44	{ 0x8000000000000000UL, "Kernel Space" },
	45	{ 0xffff810000000000UL, "Low Kernel Mapping" },
	46	{ VMALLOC_START, "vmalloc() Area" },
fe770bf0 PA	47	{ VMEMMAP_START, "Vmemmap" },
fe770bf0 PA	48	{ __START_KERNEL_map, "High Kernel Mapping" },
9a79cf9c YL	49	{ MODULES_VADDR, "Modules" },
9a79cf9c YL	50	{ MODULES_END, "End Modules" },
fe770bf0 PA	51	#else
	52	{ PAGE_OFFSET, "Kernel Mapping" },
	53	{ 0/* VMALLOC_START */, "vmalloc() Area" },
	54	{ 0/VMALLOC_END/, "vmalloc() End" },
	55	# ifdef CONFIG_HIGHMEM
	56	{ 0/PKMAP_BASE/, "Persisent kmap() Area" },
	57	# endif
	58	{ 0/FIXADDR_START/, "Fixmap Area" },
	59	#endif
	60	{ -1, NULL } /* End of list */
	61	};
926e5392	62
fe770bf0 PA	63	/* Multipliers for offsets within the PTEs */
	64	#define PTE_LEVEL_MULT (PAGE_SIZE)
	65	#define PMD_LEVEL_MULT (PTRS_PER_PTE * PTE_LEVEL_MULT)
	66	#define PUD_LEVEL_MULT (PTRS_PER_PMD * PMD_LEVEL_MULT)
	67	#define PGD_LEVEL_MULT (PTRS_PER_PUD * PUD_LEVEL_MULT)
926e5392 AV	68
	69	/*
	70	* Print a readable form of a pgprot_t to the seq_file
	71	*/
	72	static void printk_prot(struct seq_file *m, pgprot_t prot, int level)
	73	{
fe770bf0 PA	74	pgprotval_t pr = pgprot_val(prot);
	75	static const char * const level_name[] =
	76	{ "cr3", "pgd", "pud", "pmd", "pte" };
	77
	78	if (!pgprot_val(prot)) {
	79	/* Not present */
	80	seq_printf(m, " ");
	81	} else {
	82	if (pr & _PAGE_USER)
	83	seq_printf(m, "USR ");
926e5392 AV	84	else
926e5392 AV	85	seq_printf(m, " ");
fe770bf0 PA	86	if (pr & _PAGE_RW)
	87	seq_printf(m, "RW ");
	88	else
	89	seq_printf(m, "ro ");
	90	if (pr & _PAGE_PWT)
	91	seq_printf(m, "PWT ");
	92	else
	93	seq_printf(m, " ");
	94	if (pr & _PAGE_PCD)
	95	seq_printf(m, "PCD ");
926e5392 AV	96	else
926e5392 AV	97	seq_printf(m, " ");
fe770bf0 PA	98
	99	/* Bit 9 has a different meaning on level 3 vs 4 */
	100	if (level <= 3) {
	101	if (pr & _PAGE_PSE)
	102	seq_printf(m, "PSE ");
	103	else
	104	seq_printf(m, " ");
	105	} else {
	106	if (pr & _PAGE_PAT)
	107	seq_printf(m, "pat ");
	108	else
	109	seq_printf(m, " ");
	110	}
	111	if (pr & _PAGE_GLOBAL)
	112	seq_printf(m, "GLB ");
	113	else
	114	seq_printf(m, " ");
	115	if (pr & _PAGE_NX)
	116	seq_printf(m, "NX ");
	117	else
	118	seq_printf(m, "x ");
926e5392	119	}
fe770bf0	120	seq_printf(m, "%s\n", level_name[level]);
926e5392 AV	121	}
	122
	123	/*
fe770bf0	124	* On 64 bits, sign-extend the 48 bit address to 64 bit
926e5392	125	*/
fe770bf0	126	static unsigned long normalize_addr(unsigned long u)
926e5392	127	{
fe770bf0 PA	128	#ifdef CONFIG_X86_64
	129	return (signed long)(u << 16) >> 16;
	130	#else
926e5392	131	return u;
fe770bf0	132	#endif
926e5392 AV	133	}
	134
	135	/*
	136	* This function gets called on a break in a continuous series
	137	* of PTE entries; the next one is different so we need to
	138	* print what we collected so far.
	139	*/
	140	static void note_page(struct seq_file m, struct pg_state st,
fe770bf0	141	pgprot_t new_prot, int level)
926e5392	142	{
fe770bf0 PA	143	pgprotval_t prot, cur;
fe770bf0 PA	144	static const char units[] = "KMGTPE";
926e5392 AV	145
	146	/*
	147	* If we have a "break" in the series, we need to flush the state that
fe770bf0 PA	148	* we have now. "break" is either changing perms, levels or
fe770bf0 PA	149	* address space marker.
926e5392 AV	150	*/
	151	prot = pgprot_val(new_prot) & ~(PTE_MASK);
	152	cur = pgprot_val(st->current_prot) & ~(PTE_MASK);
	153
fe770bf0 PA	154	if (!st->level) {
	155	/* First entry */
	156	st->current_prot = new_prot;
	157	st->level = level;
	158	st->marker = address_markers;
	159	seq_printf(m, "---[ %s ]---\n", st->marker->name);
	160	} else if (prot != cur \|\| level != st->level \|\|
	161	st->current_address >= st->marker[1].start_address) {
	162	const char *unit = units;
926e5392 AV	163	unsigned long delta;
926e5392 AV	164
926e5392 AV	165	/*
	166	* Now print the actual finished series
	167	*/
fe770bf0 PA	168	seq_printf(m, "0x%p-0x%p ",
	169	(void *)st->start_address,
	170	(void *)st->current_address);
926e5392 AV	171
926e5392 AV	172	delta = (st->current_address - st->start_address) >> 10;
fe770bf0 PA	173	while (!(delta & 1023) && unit[1]) {
	174	delta >>= 10;
	175	unit++;
926e5392	176	}
fe770bf0 PA	177	seq_printf(m, "%9lu%c ", delta, *unit);
	178	printk_prot(m, st->current_prot, st->level);
	179
	180	/*
	181	* We print markers for special areas of address space,
	182	* such as the start of vmalloc space etc.
	183	* This helps in the interpretation.
	184	*/
	185	if (st->current_address >= st->marker[1].start_address) {
	186	st->marker++;
	187	seq_printf(m, "---[ %s ]---\n", st->marker->name);
926e5392	188	}
fe770bf0	189
926e5392 AV	190	st->start_address = st->current_address;
	191	st->current_prot = new_prot;
	192	st->level = level;
fe770bf0	193	}
926e5392 AV	194	}
926e5392 AV	195
fe770bf0	196	static void walk_pte_level(struct seq_file m, struct pg_state st, pmd_t addr,
926e5392 AV	197	unsigned long P)
	198	{
	199	int i;
	200	pte_t *start;
	201
	202	start = (pte_t *) pmd_page_vaddr(addr);
	203	for (i = 0; i < PTRS_PER_PTE; i++) {
	204	pgprot_t prot = pte_pgprot(*start);
	205
fe770bf0	206	st->current_address = normalize_addr(P + i * PTE_LEVEL_MULT);
926e5392 AV	207	note_page(m, st, prot, 4);
	208	start++;
	209	}
	210	}
	211
fe770bf0	212	#if PTRS_PER_PMD > 1
926e5392	213
fe770bf0	214	static void walk_pmd_level(struct seq_file m, struct pg_state st, pud_t addr,
926e5392 AV	215	unsigned long P)
	216	{
	217	int i;
	218	pmd_t *start;
	219
	220	start = (pmd_t *) pud_page_vaddr(addr);
	221	for (i = 0; i < PTRS_PER_PMD; i++) {
fe770bf0	222	st->current_address = normalize_addr(P + i * PMD_LEVEL_MULT);
926e5392	223	if (!pmd_none(*start)) {
fe770bf0	224	pgprotval_t prot = pmd_val(*start) & ~PTE_MASK;
926e5392	225
fe770bf0	226	if (pmd_large(start) \|\| !pmd_present(start))
926e5392 AV	227	note_page(m, st, __pgprot(prot), 3);
926e5392 AV	228	else
fe770bf0 PA	229	walk_pte_level(m, st, *start,
fe770bf0 PA	230	P + i * PMD_LEVEL_MULT);
926e5392 AV	231	} else
	232	note_page(m, st, __pgprot(0), 3);
	233	start++;
	234	}
	235	}
	236
fe770bf0 PA	237	#else
	238	#define walk_pmd_level(m,s,a,p) walk_pte_level(m,s,__pmd(pud_val(a)),p)
	239	#define pud_large(a) pmd_large(__pmd(pud_val(a)))
	240	#define pud_none(a) pmd_none(__pmd(pud_val(a)))
	241	#endif
926e5392	242
fe770bf0 PA	243	#if PTRS_PER_PUD > 1
	244
	245	static void walk_pud_level(struct seq_file m, struct pg_state st, pgd_t addr,
926e5392 AV	246	unsigned long P)
	247	{
	248	int i;
	249	pud_t *start;
	250
	251	start = (pud_t *) pgd_page_vaddr(addr);
	252
	253	for (i = 0; i < PTRS_PER_PUD; i++) {
fe770bf0	254	st->current_address = normalize_addr(P + i * PUD_LEVEL_MULT);
926e5392	255	if (!pud_none(*start)) {
fe770bf0	256	pgprotval_t prot = pud_val(*start) & ~PTE_MASK;
926e5392	257
fe770bf0	258	if (pud_large(start) \|\| !pud_present(start))
926e5392 AV	259	note_page(m, st, __pgprot(prot), 2);
926e5392 AV	260	else
fe770bf0 PA	261	walk_pmd_level(m, st, *start,
fe770bf0 PA	262	P + i * PUD_LEVEL_MULT);
926e5392 AV	263	} else
	264	note_page(m, st, __pgprot(0), 2);
	265
	266	start++;
	267	}
	268	}
	269
fe770bf0 PA	270	#else
	271	#define walk_pud_level(m,s,a,p) walk_pmd_level(m,s,__pud(pgd_val(a)),p)
	272	#define pgd_large(a) pud_large(__pud(pgd_val(a)))
	273	#define pgd_none(a) pud_none(__pud(pgd_val(a)))
	274	#endif
	275
	276	static void walk_pgd_level(struct seq_file *m)
926e5392	277	{
fe770bf0	278	#ifdef CONFIG_X86_64
926e5392	279	pgd_t start = (pgd_t ) &init_level4_pgt;
fe770bf0 PA	280	#else
	281	pgd_t *start = swapper_pg_dir;
	282	#endif
926e5392 AV	283	int i;
	284	struct pg_state st;
	285
	286	memset(&st, 0, sizeof(st));
926e5392 AV	287
926e5392 AV	288	for (i = 0; i < PTRS_PER_PGD; i++) {
fe770bf0 PA	289	st.current_address = normalize_addr(i * PGD_LEVEL_MULT);
	290	if (!pgd_none(*start)) {
	291	pgprotval_t prot = pgd_val(*start) & ~PTE_MASK;
	292
	293	if (pgd_large(start) \|\| !pgd_present(start))
	294	note_page(m, &st, __pgprot(prot), 1);
	295	else
	296	walk_pud_level(m, &st, *start,
	297	i * PGD_LEVEL_MULT);
	298	} else
926e5392	299	note_page(m, &st, __pgprot(0), 1);
fe770bf0	300
926e5392 AV	301	start++;
926e5392 AV	302	}
fe770bf0 PA	303
	304	/* Flush out the last page */
	305	st.current_address = normalize_addr(PTRS_PER_PGD*PGD_LEVEL_MULT);
	306	note_page(m, &st, __pgprot(0), 0);
926e5392 AV	307	}
	308
	309	static int ptdump_show(struct seq_file m, void v)
	310	{
fe770bf0	311	walk_pgd_level(m);
926e5392 AV	312	return 0;
	313	}
	314
	315	static int ptdump_open(struct inode inode, struct file filp)
	316	{
	317	return single_open(filp, ptdump_show, NULL);
	318	}
	319
	320	static const struct file_operations ptdump_fops = {
	321	.open = ptdump_open,
	322	.read = seq_read,
	323	.llseek = seq_lseek,
	324	.release = single_release,
	325	};
	326
a4928cff	327	static int pt_dump_init(void)
926e5392 AV	328	{
	329	struct dentry *pe;
	330
fe770bf0 PA	331	#ifdef CONFIG_X86_32
	332	/* Not a compile-time constant on x86-32 */
	333	address_markers[2].start_address = VMALLOC_START;
	334	address_markers[3].start_address = VMALLOC_END;
	335	# ifdef CONFIG_HIGHMEM
	336	address_markers[4].start_address = PKMAP_BASE;
	337	address_markers[5].start_address = FIXADDR_START;
	338	# else
	339	address_markers[4].start_address = FIXADDR_START;
	340	# endif
	341	#endif
	342
926e5392 AV	343	pe = debugfs_create_file("kernel_page_tables", 0600, NULL, NULL,
	344	&ptdump_fops);
	345	if (!pe)
	346	return -ENOMEM;
	347
	348	return 0;
	349	}
	350
	351	__initcall(pt_dump_init);
	352	MODULE_LICENSE("GPL");
	353	MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");
	354	MODULE_DESCRIPTION("Kernel debugging helper that dumps pagetables");