[deliverable/linux.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;
};

/* indices for address_markers; keep sync'd w/ address_markers below */
enum address_markers_idx {
	USER_SPACE_NR = 0,
#ifdef CONFIG_X86_64
	KERNEL_SPACE_NR,
	LOW_KERNEL_NR,
	VMALLOC_START_NR,
	VMEMMAP_START_NR,
	HIGH_KERNEL_NR,
	MODULES_VADDR_NR,
	MODULES_END_NR,
#else
	KERNEL_SPACE_NR,
	VMALLOC_START_NR,
	VMALLOC_END_NR,
# ifdef CONFIG_HIGHMEM
	PKMAP_BASE_NR,
# endif
	FIXADDR_START_NR,
#endif
};

/* Address space markers hints */
static struct addr_marker address_markers[] = {
	{ 0, "User Space" },
#ifdef CONFIG_X86_64
	{ 0x8000000000000000UL, "Kernel Space" },
	{ PAGE_OFFSET,		"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_FLAGS_MASK;
	cur = pgprot_val(st->current_prot) & PTE_FLAGS_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;
		int width = sizeof(unsigned long) * 2;

		/*
		 * Now print the actual finished series
		 */
		seq_printf(m, "0x%0*lx-0x%0*lx   ",
			   width, st->start_address,
			   width, 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_FLAGS_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_FLAGS_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_FLAGS_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[VMALLOC_START_NR].start_address = VMALLOC_START;
	address_markers[VMALLOC_END_NR].start_address = VMALLOC_END;
# ifdef CONFIG_HIGHMEM
	address_markers[PKMAP_BASE_NR].start_address = PKMAP_BASE;
# endif
	address_markers[FIXADDR_START_NR].start_address = FIXADDR_START;
#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
92851e2f AS	40	/* indices for address_markers; keep sync'd w/ address_markers below */
	41	enum address_markers_idx {
	42	USER_SPACE_NR = 0,
	43	#ifdef CONFIG_X86_64
	44	KERNEL_SPACE_NR,
	45	LOW_KERNEL_NR,
	46	VMALLOC_START_NR,
	47	VMEMMAP_START_NR,
	48	HIGH_KERNEL_NR,
	49	MODULES_VADDR_NR,
	50	MODULES_END_NR,
	51	#else
	52	KERNEL_SPACE_NR,
	53	VMALLOC_START_NR,
	54	VMALLOC_END_NR,
	55	# ifdef CONFIG_HIGHMEM
	56	PKMAP_BASE_NR,
	57	# endif
	58	FIXADDR_START_NR,
	59	#endif
	60	};
	61
fe770bf0 PA	62	/* Address space markers hints */
	63	static struct addr_marker address_markers[] = {
	64	{ 0, "User Space" },
	65	#ifdef CONFIG_X86_64
	66	{ 0x8000000000000000UL, "Kernel Space" },
684eb016	67	{ PAGE_OFFSET, "Low Kernel Mapping" },
fe770bf0	68	{ VMALLOC_START, "vmalloc() Area" },
fe770bf0 PA	69	{ VMEMMAP_START, "Vmemmap" },
fe770bf0 PA	70	{ __START_KERNEL_map, "High Kernel Mapping" },
9a79cf9c YL	71	{ MODULES_VADDR, "Modules" },
9a79cf9c YL	72	{ MODULES_END, "End Modules" },
fe770bf0 PA	73	#else
	74	{ PAGE_OFFSET, "Kernel Mapping" },
	75	{ 0/* VMALLOC_START */, "vmalloc() Area" },
	76	{ 0/VMALLOC_END/, "vmalloc() End" },
	77	# ifdef CONFIG_HIGHMEM
	78	{ 0/PKMAP_BASE/, "Persisent kmap() Area" },
	79	# endif
	80	{ 0/FIXADDR_START/, "Fixmap Area" },
	81	#endif
	82	{ -1, NULL } /* End of list */
	83	};
926e5392	84
fe770bf0 PA	85	/* Multipliers for offsets within the PTEs */
	86	#define PTE_LEVEL_MULT (PAGE_SIZE)
	87	#define PMD_LEVEL_MULT (PTRS_PER_PTE * PTE_LEVEL_MULT)
	88	#define PUD_LEVEL_MULT (PTRS_PER_PMD * PMD_LEVEL_MULT)
	89	#define PGD_LEVEL_MULT (PTRS_PER_PUD * PUD_LEVEL_MULT)
926e5392 AV	90
	91	/*
	92	* Print a readable form of a pgprot_t to the seq_file
	93	*/
	94	static void printk_prot(struct seq_file *m, pgprot_t prot, int level)
	95	{
fe770bf0 PA	96	pgprotval_t pr = pgprot_val(prot);
	97	static const char * const level_name[] =
	98	{ "cr3", "pgd", "pud", "pmd", "pte" };
	99
	100	if (!pgprot_val(prot)) {
	101	/* Not present */
	102	seq_printf(m, " ");
	103	} else {
	104	if (pr & _PAGE_USER)
	105	seq_printf(m, "USR ");
926e5392 AV	106	else
926e5392 AV	107	seq_printf(m, " ");
fe770bf0 PA	108	if (pr & _PAGE_RW)
	109	seq_printf(m, "RW ");
	110	else
	111	seq_printf(m, "ro ");
	112	if (pr & _PAGE_PWT)
	113	seq_printf(m, "PWT ");
	114	else
	115	seq_printf(m, " ");
	116	if (pr & _PAGE_PCD)
	117	seq_printf(m, "PCD ");
926e5392 AV	118	else
926e5392 AV	119	seq_printf(m, " ");
fe770bf0 PA	120
	121	/* Bit 9 has a different meaning on level 3 vs 4 */
	122	if (level <= 3) {
	123	if (pr & _PAGE_PSE)
	124	seq_printf(m, "PSE ");
	125	else
	126	seq_printf(m, " ");
	127	} else {
	128	if (pr & _PAGE_PAT)
	129	seq_printf(m, "pat ");
	130	else
	131	seq_printf(m, " ");
	132	}
	133	if (pr & _PAGE_GLOBAL)
	134	seq_printf(m, "GLB ");
	135	else
	136	seq_printf(m, " ");
	137	if (pr & _PAGE_NX)
	138	seq_printf(m, "NX ");
	139	else
	140	seq_printf(m, "x ");
926e5392	141	}
fe770bf0	142	seq_printf(m, "%s\n", level_name[level]);
926e5392 AV	143	}
	144
	145	/*
fe770bf0	146	* On 64 bits, sign-extend the 48 bit address to 64 bit
926e5392	147	*/
fe770bf0	148	static unsigned long normalize_addr(unsigned long u)
926e5392	149	{
fe770bf0 PA	150	#ifdef CONFIG_X86_64
	151	return (signed long)(u << 16) >> 16;
	152	#else
926e5392	153	return u;
fe770bf0	154	#endif
926e5392 AV	155	}
	156
	157	/*
	158	* This function gets called on a break in a continuous series
	159	* of PTE entries; the next one is different so we need to
	160	* print what we collected so far.
	161	*/
	162	static void note_page(struct seq_file m, struct pg_state st,
fe770bf0	163	pgprot_t new_prot, int level)
926e5392	164	{
fe770bf0 PA	165	pgprotval_t prot, cur;
fe770bf0 PA	166	static const char units[] = "KMGTPE";
926e5392 AV	167
	168	/*
	169	* If we have a "break" in the series, we need to flush the state that
fe770bf0 PA	170	* we have now. "break" is either changing perms, levels or
fe770bf0 PA	171	* address space marker.
926e5392	172	*/
27990eac JF	173	prot = pgprot_val(new_prot) & PTE_FLAGS_MASK;
27990eac JF	174	cur = pgprot_val(st->current_prot) & PTE_FLAGS_MASK;
926e5392	175
fe770bf0 PA	176	if (!st->level) {
	177	/* First entry */
	178	st->current_prot = new_prot;
	179	st->level = level;
	180	st->marker = address_markers;
	181	seq_printf(m, "---[ %s ]---\n", st->marker->name);
	182	} else if (prot != cur \|\| level != st->level \|\|
	183	st->current_address >= st->marker[1].start_address) {
	184	const char *unit = units;
926e5392	185	unsigned long delta;
6424fb38	186	int width = sizeof(unsigned long) * 2;
926e5392	187
926e5392 AV	188	/*
	189	* Now print the actual finished series
	190	*/
6424fb38 YL	191	seq_printf(m, "0x%0lx-0x%0lx ",
	192	width, st->start_address,
	193	width, st->current_address);
926e5392 AV	194
926e5392 AV	195	delta = (st->current_address - st->start_address) >> 10;
fe770bf0 PA	196	while (!(delta & 1023) && unit[1]) {
	197	delta >>= 10;
	198	unit++;
926e5392	199	}
fe770bf0 PA	200	seq_printf(m, "%9lu%c ", delta, *unit);
	201	printk_prot(m, st->current_prot, st->level);
	202
	203	/*
	204	* We print markers for special areas of address space,
	205	* such as the start of vmalloc space etc.
	206	* This helps in the interpretation.
	207	*/
	208	if (st->current_address >= st->marker[1].start_address) {
	209	st->marker++;
	210	seq_printf(m, "---[ %s ]---\n", st->marker->name);
926e5392	211	}
fe770bf0	212
926e5392 AV	213	st->start_address = st->current_address;
	214	st->current_prot = new_prot;
	215	st->level = level;
fe770bf0	216	}
926e5392 AV	217	}
926e5392 AV	218
fe770bf0	219	static void walk_pte_level(struct seq_file m, struct pg_state st, pmd_t addr,
926e5392 AV	220	unsigned long P)
	221	{
	222	int i;
	223	pte_t *start;
	224
	225	start = (pte_t *) pmd_page_vaddr(addr);
	226	for (i = 0; i < PTRS_PER_PTE; i++) {
	227	pgprot_t prot = pte_pgprot(*start);
	228
fe770bf0	229	st->current_address = normalize_addr(P + i * PTE_LEVEL_MULT);
926e5392 AV	230	note_page(m, st, prot, 4);
	231	start++;
	232	}
	233	}
	234
fe770bf0	235	#if PTRS_PER_PMD > 1
926e5392	236
fe770bf0	237	static void walk_pmd_level(struct seq_file m, struct pg_state st, pud_t addr,
926e5392 AV	238	unsigned long P)
	239	{
	240	int i;
	241	pmd_t *start;
	242
	243	start = (pmd_t *) pud_page_vaddr(addr);
	244	for (i = 0; i < PTRS_PER_PMD; i++) {
fe770bf0	245	st->current_address = normalize_addr(P + i * PMD_LEVEL_MULT);
926e5392	246	if (!pmd_none(*start)) {
77be1fab	247	pgprotval_t prot = pmd_val(*start) & PTE_FLAGS_MASK;
926e5392	248
fe770bf0	249	if (pmd_large(start) \|\| !pmd_present(start))
926e5392 AV	250	note_page(m, st, __pgprot(prot), 3);
926e5392 AV	251	else
fe770bf0 PA	252	walk_pte_level(m, st, *start,
fe770bf0 PA	253	P + i * PMD_LEVEL_MULT);
926e5392 AV	254	} else
	255	note_page(m, st, __pgprot(0), 3);
	256	start++;
	257	}
	258	}
	259
fe770bf0 PA	260	#else
	261	#define walk_pmd_level(m,s,a,p) walk_pte_level(m,s,__pmd(pud_val(a)),p)
	262	#define pud_large(a) pmd_large(__pmd(pud_val(a)))
	263	#define pud_none(a) pmd_none(__pmd(pud_val(a)))
	264	#endif
926e5392	265
fe770bf0 PA	266	#if PTRS_PER_PUD > 1
	267
	268	static void walk_pud_level(struct seq_file m, struct pg_state st, pgd_t addr,
926e5392 AV	269	unsigned long P)
	270	{
	271	int i;
	272	pud_t *start;
	273
	274	start = (pud_t *) pgd_page_vaddr(addr);
	275
	276	for (i = 0; i < PTRS_PER_PUD; i++) {
fe770bf0	277	st->current_address = normalize_addr(P + i * PUD_LEVEL_MULT);
926e5392	278	if (!pud_none(*start)) {
77be1fab	279	pgprotval_t prot = pud_val(*start) & PTE_FLAGS_MASK;
926e5392	280
fe770bf0	281	if (pud_large(start) \|\| !pud_present(start))
926e5392 AV	282	note_page(m, st, __pgprot(prot), 2);
926e5392 AV	283	else
fe770bf0 PA	284	walk_pmd_level(m, st, *start,
fe770bf0 PA	285	P + i * PUD_LEVEL_MULT);
926e5392 AV	286	} else
	287	note_page(m, st, __pgprot(0), 2);
	288
	289	start++;
	290	}
	291	}
	292
fe770bf0 PA	293	#else
	294	#define walk_pud_level(m,s,a,p) walk_pmd_level(m,s,__pud(pgd_val(a)),p)
	295	#define pgd_large(a) pud_large(__pud(pgd_val(a)))
	296	#define pgd_none(a) pud_none(__pud(pgd_val(a)))
	297	#endif
	298
	299	static void walk_pgd_level(struct seq_file *m)
926e5392	300	{
fe770bf0	301	#ifdef CONFIG_X86_64
926e5392	302	pgd_t start = (pgd_t ) &init_level4_pgt;
fe770bf0 PA	303	#else
	304	pgd_t *start = swapper_pg_dir;
	305	#endif
926e5392 AV	306	int i;
	307	struct pg_state st;
	308
	309	memset(&st, 0, sizeof(st));
926e5392 AV	310
926e5392 AV	311	for (i = 0; i < PTRS_PER_PGD; i++) {
fe770bf0 PA	312	st.current_address = normalize_addr(i * PGD_LEVEL_MULT);
fe770bf0 PA	313	if (!pgd_none(*start)) {
77be1fab	314	pgprotval_t prot = pgd_val(*start) & PTE_FLAGS_MASK;
fe770bf0 PA	315
	316	if (pgd_large(start) \|\| !pgd_present(start))
	317	note_page(m, &st, __pgprot(prot), 1);
	318	else
	319	walk_pud_level(m, &st, *start,
	320	i * PGD_LEVEL_MULT);
	321	} else
926e5392	322	note_page(m, &st, __pgprot(0), 1);
fe770bf0	323
926e5392 AV	324	start++;
926e5392 AV	325	}
fe770bf0 PA	326
	327	/* Flush out the last page */
	328	st.current_address = normalize_addr(PTRS_PER_PGD*PGD_LEVEL_MULT);
	329	note_page(m, &st, __pgprot(0), 0);
926e5392 AV	330	}
	331
	332	static int ptdump_show(struct seq_file m, void v)
	333	{
fe770bf0	334	walk_pgd_level(m);
926e5392 AV	335	return 0;
	336	}
	337
	338	static int ptdump_open(struct inode inode, struct file filp)
	339	{
	340	return single_open(filp, ptdump_show, NULL);
	341	}
	342
	343	static const struct file_operations ptdump_fops = {
	344	.open = ptdump_open,
	345	.read = seq_read,
	346	.llseek = seq_lseek,
	347	.release = single_release,
	348	};
	349
a4928cff	350	static int pt_dump_init(void)
926e5392 AV	351	{
	352	struct dentry *pe;
	353
fe770bf0 PA	354	#ifdef CONFIG_X86_32
fe770bf0 PA	355	/* Not a compile-time constant on x86-32 */
92851e2f AS	356	address_markers[VMALLOC_START_NR].start_address = VMALLOC_START;
92851e2f AS	357	address_markers[VMALLOC_END_NR].start_address = VMALLOC_END;
fe770bf0	358	# ifdef CONFIG_HIGHMEM
92851e2f	359	address_markers[PKMAP_BASE_NR].start_address = PKMAP_BASE;
fe770bf0	360	# endif
92851e2f	361	address_markers[FIXADDR_START_NR].start_address = FIXADDR_START;
fe770bf0 PA	362	#endif
fe770bf0 PA	363
926e5392 AV	364	pe = debugfs_create_file("kernel_page_tables", 0600, NULL, NULL,
	365	&ptdump_fops);
	366	if (!pe)
	367	return -ENOMEM;
	368
	369	return 0;
	370	}
	371
	372	__initcall(pt_dump_init);
	373	MODULE_LICENSE("GPL");
	374	MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");
	375	MODULE_DESCRIPTION("Kernel debugging helper that dumps pagetables");