[deliverable/linux.git] / arch / arm64 / mm / dump.c

/*
 * Copyright (c) 2014, The Linux Foundation. All rights reserved.
 * Debug helper to dump the current kernel pagetables of the system
 * so that we can see what the various memory ranges are set to.
 *
 * Derived from x86 and arm implementation:
 * (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/errno.h>
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/seq_file.h>

#include <asm/fixmap.h>
#include <asm/kasan.h>
#include <asm/memory.h>
#include <asm/pgtable.h>
#include <asm/pgtable-hwdef.h>

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

static const struct addr_marker address_markers[] = {
#ifdef CONFIG_KASAN
	{ KASAN_SHADOW_START,		"Kasan shadow start" },
	{ KASAN_SHADOW_END,		"Kasan shadow end" },
#endif
	{ MODULES_VADDR,		"Modules start" },
	{ MODULES_END,			"Modules end" },
	{ VMALLOC_START,		"vmalloc() Area" },
	{ VMALLOC_END,			"vmalloc() End" },
	{ FIXADDR_START,		"Fixmap start" },
	{ FIXADDR_TOP,			"Fixmap end" },
	{ PCI_IO_START,			"PCI I/O start" },
	{ PCI_IO_END,			"PCI I/O end" },
#ifdef CONFIG_SPARSEMEM_VMEMMAP
	{ VMEMMAP_START,		"vmemmap start" },
	{ VMEMMAP_START + VMEMMAP_SIZE,	"vmemmap end" },
#endif
	{ PAGE_OFFSET,			"Linear Mapping" },
	{ -1,				NULL },
};

/*
 * The page dumper groups page table entries of the same type into a single
 * description. It uses pg_state to track the range information while
 * iterating over the pte entries. When the continuity is broken it then
 * dumps out a description of the range.
 */
struct pg_state {
	struct seq_file *seq;
	const struct addr_marker *marker;
	unsigned long start_address;
	unsigned level;
	u64 current_prot;
};

struct prot_bits {
	u64		mask;
	u64		val;
	const char	*set;
	const char	*clear;
};

static const struct prot_bits pte_bits[] = {
	{
		.mask	= PTE_VALID,
		.val	= PTE_VALID,
		.set	= " ",
		.clear	= "F",
	}, {
		.mask	= PTE_USER,
		.val	= PTE_USER,
		.set	= "USR",
		.clear	= "   ",
	}, {
		.mask	= PTE_RDONLY,
		.val	= PTE_RDONLY,
		.set	= "ro",
		.clear	= "RW",
	}, {
		.mask	= PTE_PXN,
		.val	= PTE_PXN,
		.set	= "NX",
		.clear	= "x ",
	}, {
		.mask	= PTE_SHARED,
		.val	= PTE_SHARED,
		.set	= "SHD",
		.clear	= "   ",
	}, {
		.mask	= PTE_AF,
		.val	= PTE_AF,
		.set	= "AF",
		.clear	= "  ",
	}, {
		.mask	= PTE_NG,
		.val	= PTE_NG,
		.set	= "NG",
		.clear	= "  ",
	}, {
		.mask	= PTE_CONT,
		.val	= PTE_CONT,
		.set	= "CON",
		.clear	= "   ",
	}, {
		.mask	= PTE_TABLE_BIT,
		.val	= PTE_TABLE_BIT,
		.set	= "   ",
		.clear	= "BLK",
	}, {
		.mask	= PTE_UXN,
		.val	= PTE_UXN,
		.set	= "UXN",
	}, {
		.mask	= PTE_ATTRINDX_MASK,
		.val	= PTE_ATTRINDX(MT_DEVICE_nGnRnE),
		.set	= "DEVICE/nGnRnE",
	}, {
		.mask	= PTE_ATTRINDX_MASK,
		.val	= PTE_ATTRINDX(MT_DEVICE_nGnRE),
		.set	= "DEVICE/nGnRE",
	}, {
		.mask	= PTE_ATTRINDX_MASK,
		.val	= PTE_ATTRINDX(MT_DEVICE_GRE),
		.set	= "DEVICE/GRE",
	}, {
		.mask	= PTE_ATTRINDX_MASK,
		.val	= PTE_ATTRINDX(MT_NORMAL_NC),
		.set	= "MEM/NORMAL-NC",
	}, {
		.mask	= PTE_ATTRINDX_MASK,
		.val	= PTE_ATTRINDX(MT_NORMAL),
		.set	= "MEM/NORMAL",
	}
};

struct pg_level {
	const struct prot_bits *bits;
	size_t num;
	u64 mask;
};

static struct pg_level pg_level[] = {
	{
	}, { /* pgd */
		.bits	= pte_bits,
		.num	= ARRAY_SIZE(pte_bits),
	}, { /* pud */
		.bits	= pte_bits,
		.num	= ARRAY_SIZE(pte_bits),
	}, { /* pmd */
		.bits	= pte_bits,
		.num	= ARRAY_SIZE(pte_bits),
	}, { /* pte */
		.bits	= pte_bits,
		.num	= ARRAY_SIZE(pte_bits),
	},
};

static void dump_prot(struct pg_state *st, const struct prot_bits *bits,
			size_t num)
{
	unsigned i;

	for (i = 0; i < num; i++, bits++) {
		const char *s;

		if ((st->current_prot & bits->mask) == bits->val)
			s = bits->set;
		else
			s = bits->clear;

		if (s)
			seq_printf(st->seq, " %s", s);
	}
}

static void note_page(struct pg_state *st, unsigned long addr, unsigned level,
				u64 val)
{
	static const char units[] = "KMGTPE";
	u64 prot = val & pg_level[level].mask;

	if (!st->level) {
		st->level = level;
		st->current_prot = prot;
		st->start_address = addr;
		seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
	} else if (prot != st->current_prot || level != st->level ||
		   addr >= st->marker[1].start_address) {
		const char *unit = units;
		unsigned long delta;

		if (st->current_prot) {
			seq_printf(st->seq, "0x%016lx-0x%016lx   ",
				   st->start_address, addr);

			delta = (addr - st->start_address) >> 10;
			while (!(delta & 1023) && unit[1]) {
				delta >>= 10;
				unit++;
			}
			seq_printf(st->seq, "%9lu%c", delta, *unit);
			if (pg_level[st->level].bits)
				dump_prot(st, pg_level[st->level].bits,
					  pg_level[st->level].num);
			seq_puts(st->seq, "\n");
		}

		if (addr >= st->marker[1].start_address) {
			st->marker++;
			seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
		}

		st->start_address = addr;
		st->current_prot = prot;
		st->level = level;
	}

	if (addr >= st->marker[1].start_address) {
		st->marker++;
		seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
	}

}

static void walk_pte(struct pg_state *st, pmd_t *pmd, unsigned long start)
{
	pte_t *pte = pte_offset_kernel(pmd, 0);
	unsigned long addr;
	unsigned i;

	for (i = 0; i < PTRS_PER_PTE; i++, pte++) {
		addr = start + i * PAGE_SIZE;
		note_page(st, addr, 4, pte_val(*pte));
	}
}

static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start)
{
	pmd_t *pmd = pmd_offset(pud, 0);
	unsigned long addr;
	unsigned i;

	for (i = 0; i < PTRS_PER_PMD; i++, pmd++) {
		addr = start + i * PMD_SIZE;
		if (pmd_none(*pmd) || pmd_sect(*pmd)) {
			note_page(st, addr, 3, pmd_val(*pmd));
		} else {
			BUG_ON(pmd_bad(*pmd));
			walk_pte(st, pmd, addr);
		}
	}
}

static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start)
{
	pud_t *pud = pud_offset(pgd, 0);
	unsigned long addr;
	unsigned i;

	for (i = 0; i < PTRS_PER_PUD; i++, pud++) {
		addr = start + i * PUD_SIZE;
		if (pud_none(*pud) || pud_sect(*pud)) {
			note_page(st, addr, 2, pud_val(*pud));
		} else {
			BUG_ON(pud_bad(*pud));
			walk_pmd(st, pud, addr);
		}
	}
}

static void walk_pgd(struct pg_state *st, struct mm_struct *mm, unsigned long start)
{
	pgd_t *pgd = pgd_offset(mm, 0UL);
	unsigned i;
	unsigned long addr;

	for (i = 0; i < PTRS_PER_PGD; i++, pgd++) {
		addr = start + i * PGDIR_SIZE;
		if (pgd_none(*pgd)) {
			note_page(st, addr, 1, pgd_val(*pgd));
		} else {
			BUG_ON(pgd_bad(*pgd));
			walk_pud(st, pgd, addr);
		}
	}
}

static int ptdump_show(struct seq_file *m, void *v)
{
	struct pg_state st = {
		.seq = m,
		.marker = address_markers,
	};

	walk_pgd(&st, &init_mm, VA_START);

	note_page(&st, 0, 0, 0);
	return 0;
}

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

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

static int ptdump_init(void)
{
	struct dentry *pe;
	unsigned i, j;

	for (i = 0; i < ARRAY_SIZE(pg_level); i++)
		if (pg_level[i].bits)
			for (j = 0; j < pg_level[i].num; j++)
				pg_level[i].mask |= pg_level[i].bits[j].mask;

	pe = debugfs_create_file("kernel_page_tables", 0400, NULL, NULL,
				 &ptdump_fops);
	return pe ? 0 : -ENOMEM;
}
device_initcall(ptdump_init);
Commit	Line	Data
c9465b4e LA	1	/*
	2	* Copyright (c) 2014, The Linux Foundation. All rights reserved.
	3	* Debug helper to dump the current kernel pagetables of the system
	4	* so that we can see what the various memory ranges are set to.
	5	*
	6	* Derived from x86 and arm implementation:
	7	* (C) Copyright 2008 Intel Corporation
	8	*
	9	* Author: Arjan van de Ven <arjan@linux.intel.com>
	10	*
	11	* This program is free software; you can redistribute it and/or
	12	* modify it under the terms of the GNU General Public License
	13	* as published by the Free Software Foundation; version 2
	14	* of the License.
	15	*/
	16	#include <linux/debugfs.h>
764011ca	17	#include <linux/errno.h>
c9465b4e	18	#include <linux/fs.h>
284be285	19	#include <linux/io.h>
764011ca	20	#include <linux/init.h>
c9465b4e LA	21	#include <linux/mm.h>
	22	#include <linux/sched.h>
	23	#include <linux/seq_file.h>
	24
	25	#include <asm/fixmap.h>
d8fc68a0	26	#include <asm/kasan.h>
764011ca	27	#include <asm/memory.h>
c9465b4e	28	#include <asm/pgtable.h>
764011ca	29	#include <asm/pgtable-hwdef.h>
c9465b4e	30
c9465b4e LA	31	struct addr_marker {
	32	unsigned long start_address;
	33	const char *name;
	34	};
	35
c8f8cca4	36	static const struct addr_marker address_markers[] = {
d8fc68a0 AB	37	#ifdef CONFIG_KASAN
	38	{ KASAN_SHADOW_START, "Kasan shadow start" },
	39	{ KASAN_SHADOW_END, "Kasan shadow end" },
	40	#endif
c8f8cca4 AB	41	{ MODULES_VADDR, "Modules start" },
	42	{ MODULES_END, "Modules end" },
	43	{ VMALLOC_START, "vmalloc() Area" },
	44	{ VMALLOC_END, "vmalloc() End" },
	45	{ FIXADDR_START, "Fixmap start" },
	46	{ FIXADDR_TOP, "Fixmap end" },
	47	{ PCI_IO_START, "PCI I/O start" },
	48	{ PCI_IO_END, "PCI I/O end" },
3e1907d5	49	#ifdef CONFIG_SPARSEMEM_VMEMMAP
c8f8cca4 AB	50	{ VMEMMAP_START, "vmemmap start" },
c8f8cca4 AB	51	{ VMEMMAP_START + VMEMMAP_SIZE, "vmemmap end" },
3e1907d5	52	#endif
c8f8cca4 AB	53	{ PAGE_OFFSET, "Linear Mapping" },
c8f8cca4 AB	54	{ -1, NULL },
c9465b4e LA	55	};
c9465b4e LA	56
202e41a1 JL	57	/*
	58	* The page dumper groups page table entries of the same type into a single
	59	* description. It uses pg_state to track the range information while
	60	* iterating over the pte entries. When the continuity is broken it then
	61	* dumps out a description of the range.
	62	*/
c9465b4e LA	63	struct pg_state {
	64	struct seq_file *seq;
	65	const struct addr_marker *marker;
	66	unsigned long start_address;
	67	unsigned level;
	68	u64 current_prot;
	69	};
	70
	71	struct prot_bits {
	72	u64 mask;
	73	u64 val;
	74	const char *set;
	75	const char *clear;
	76	};
	77
	78	static const struct prot_bits pte_bits[] = {
	79	{
d7e9d594 LA	80	.mask = PTE_VALID,
	81	.val = PTE_VALID,
	82	.set = " ",
	83	.clear = "F",
	84	}, {
c9465b4e LA	85	.mask = PTE_USER,
	86	.val = PTE_USER,
	87	.set = "USR",
	88	.clear = " ",
	89	}, {
	90	.mask = PTE_RDONLY,
	91	.val = PTE_RDONLY,
	92	.set = "ro",
	93	.clear = "RW",
	94	}, {
	95	.mask = PTE_PXN,
	96	.val = PTE_PXN,
	97	.set = "NX",
	98	.clear = "x ",
	99	}, {
	100	.mask = PTE_SHARED,
	101	.val = PTE_SHARED,
	102	.set = "SHD",
	103	.clear = " ",
	104	}, {
	105	.mask = PTE_AF,
	106	.val = PTE_AF,
	107	.set = "AF",
	108	.clear = " ",
	109	}, {
	110	.mask = PTE_NG,
	111	.val = PTE_NG,
	112	.set = "NG",
	113	.clear = " ",
202e41a1 JL	114	}, {
	115	.mask = PTE_CONT,
	116	.val = PTE_CONT,
	117	.set = "CON",
	118	.clear = " ",
	119	}, {
	120	.mask = PTE_TABLE_BIT,
	121	.val = PTE_TABLE_BIT,
	122	.set = " ",
	123	.clear = "BLK",
c9465b4e LA	124	}, {
	125	.mask = PTE_UXN,
	126	.val = PTE_UXN,
	127	.set = "UXN",
	128	}, {
	129	.mask = PTE_ATTRINDX_MASK,
	130	.val = PTE_ATTRINDX(MT_DEVICE_nGnRnE),
	131	.set = "DEVICE/nGnRnE",
	132	}, {
	133	.mask = PTE_ATTRINDX_MASK,
	134	.val = PTE_ATTRINDX(MT_DEVICE_nGnRE),
	135	.set = "DEVICE/nGnRE",
	136	}, {
	137	.mask = PTE_ATTRINDX_MASK,
	138	.val = PTE_ATTRINDX(MT_DEVICE_GRE),
	139	.set = "DEVICE/GRE",
	140	}, {
	141	.mask = PTE_ATTRINDX_MASK,
	142	.val = PTE_ATTRINDX(MT_NORMAL_NC),
	143	.set = "MEM/NORMAL-NC",
	144	}, {
	145	.mask = PTE_ATTRINDX_MASK,
	146	.val = PTE_ATTRINDX(MT_NORMAL),
	147	.set = "MEM/NORMAL",
	148	}
	149	};
	150
	151	struct pg_level {
	152	const struct prot_bits *bits;
	153	size_t num;
	154	u64 mask;
	155	};
	156
	157	static struct pg_level pg_level[] = {
	158	{
	159	}, { /* pgd */
	160	.bits = pte_bits,
	161	.num = ARRAY_SIZE(pte_bits),
	162	}, { /* pud */
	163	.bits = pte_bits,
	164	.num = ARRAY_SIZE(pte_bits),
	165	}, { /* pmd */
	166	.bits = pte_bits,
	167	.num = ARRAY_SIZE(pte_bits),
	168	}, { /* pte */
	169	.bits = pte_bits,
	170	.num = ARRAY_SIZE(pte_bits),
	171	},
	172	};
	173
	174	static void dump_prot(struct pg_state st, const struct prot_bits bits,
	175	size_t num)
	176	{
	177	unsigned i;
	178
	179	for (i = 0; i < num; i++, bits++) {
	180	const char *s;
	181
	182	if ((st->current_prot & bits->mask) == bits->val)
	183	s = bits->set;
	184	else
	185	s = bits->clear;
	186
	187	if (s)
188	seq_printf(st->seq, " %s", s);
189	}
190	}
191
192	static void note_page(struct pg_state *st, unsigned long addr, unsigned level,
193	u64 val)
194	{
195	static const char units[] = "KMGTPE";
196	u64 prot = val & pg_level[level].mask;
197
c9465b4e LA	198	if (!st->level) {
	199	st->level = level;
	200	st->current_prot = prot;
	201	st->start_address = addr;
	202	seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
	203	} else if (prot != st->current_prot \|\| level != st->level \|\|
	204	addr >= st->marker[1].start_address) {
	205	const char *unit = units;
	206	unsigned long delta;
	207
	208	if (st->current_prot) {
202e41a1	209	seq_printf(st->seq, "0x%016lx-0x%016lx ",
c9465b4e LA	210	st->start_address, addr);
	211
	212	delta = (addr - st->start_address) >> 10;
	213	while (!(delta & 1023) && unit[1]) {
	214	delta >>= 10;
	215	unit++;
	216	}
	217	seq_printf(st->seq, "%9lu%c", delta, *unit);
	218	if (pg_level[st->level].bits)
	219	dump_prot(st, pg_level[st->level].bits,
	220	pg_level[st->level].num);
	221	seq_puts(st->seq, "\n");
	222	}
	223
	224	if (addr >= st->marker[1].start_address) {
	225	st->marker++;
	226	seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
	227	}
	228
	229	st->start_address = addr;
	230	st->current_prot = prot;
	231	st->level = level;
	232	}
	233
	234	if (addr >= st->marker[1].start_address) {
	235	st->marker++;
	236	seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
	237	}
	238
	239	}
	240
	241	static void walk_pte(struct pg_state st, pmd_t pmd, unsigned long start)
	242	{
	243	pte_t *pte = pte_offset_kernel(pmd, 0);
	244	unsigned long addr;
	245	unsigned i;
	246
	247	for (i = 0; i < PTRS_PER_PTE; i++, pte++) {
	248	addr = start + i * PAGE_SIZE;
	249	note_page(st, addr, 4, pte_val(*pte));
	250	}
	251	}
	252
	253	static void walk_pmd(struct pg_state st, pud_t pud, unsigned long start)
	254	{
	255	pmd_t *pmd = pmd_offset(pud, 0);
	256	unsigned long addr;
	257	unsigned i;
	258
	259	for (i = 0; i < PTRS_PER_PMD; i++, pmd++) {
	260	addr = start + i * PMD_SIZE;
a1c76574	261	if (pmd_none(pmd) \|\| pmd_sect(pmd)) {
c9465b4e	262	note_page(st, addr, 3, pmd_val(*pmd));
a1c76574 MR	263	} else {
a1c76574 MR	264	BUG_ON(pmd_bad(*pmd));
c9465b4e	265	walk_pte(st, pmd, addr);
a1c76574	266	}
c9465b4e LA	267	}
	268	}
	269
	270	static void walk_pud(struct pg_state st, pgd_t pgd, unsigned long start)
	271	{
	272	pud_t *pud = pud_offset(pgd, 0);
	273	unsigned long addr;
	274	unsigned i;
	275
	276	for (i = 0; i < PTRS_PER_PUD; i++, pud++) {
	277	addr = start + i * PUD_SIZE;
a1c76574	278	if (pud_none(pud) \|\| pud_sect(pud)) {
c9465b4e	279	note_page(st, addr, 2, pud_val(*pud));
a1c76574 MR	280	} else {
a1c76574 MR	281	BUG_ON(pud_bad(*pud));
c9465b4e	282	walk_pmd(st, pud, addr);
a1c76574	283	}
c9465b4e LA	284	}
	285	}
	286
	287	static void walk_pgd(struct pg_state st, struct mm_struct mm, unsigned long start)
	288	{
35545f0c	289	pgd_t *pgd = pgd_offset(mm, 0UL);
c9465b4e LA	290	unsigned i;
	291	unsigned long addr;
	292
	293	for (i = 0; i < PTRS_PER_PGD; i++, pgd++) {
	294	addr = start + i * PGDIR_SIZE;
a1c76574	295	if (pgd_none(*pgd)) {
c9465b4e	296	note_page(st, addr, 1, pgd_val(*pgd));
a1c76574 MR	297	} else {
a1c76574 MR	298	BUG_ON(pgd_bad(*pgd));
c9465b4e	299	walk_pud(st, pgd, addr);
a1c76574	300	}
c9465b4e LA	301	}
	302	}
	303
	304	static int ptdump_show(struct seq_file m, void v)
	305	{
	306	struct pg_state st = {
	307	.seq = m,
	308	.marker = address_markers,
	309	};
	310
cc30e6b9	311	walk_pgd(&st, &init_mm, VA_START);
c9465b4e LA	312
	313	note_page(&st, 0, 0, 0);
	314	return 0;
	315	}
	316
	317	static int ptdump_open(struct inode inode, struct file file)
	318	{
	319	return single_open(file, ptdump_show, NULL);
	320	}
	321
	322	static const struct file_operations ptdump_fops = {
	323	.open = ptdump_open,
	324	.read = seq_read,
	325	.llseek = seq_lseek,
	326	.release = single_release,
	327	};
	328
	329	static int ptdump_init(void)
	330	{
	331	struct dentry *pe;
	332	unsigned i, j;
	333
	334	for (i = 0; i < ARRAY_SIZE(pg_level); i++)
	335	if (pg_level[i].bits)
	336	for (j = 0; j < pg_level[i].num; j++)
	337	pg_level[i].mask \|= pg_level[i].bits[j].mask;
	338
c9465b4e LA	339	pe = debugfs_create_file("kernel_page_tables", 0400, NULL, NULL,
	340	&ptdump_fops);
	341	return pe ? 0 : -ENOMEM;
	342	}
	343	device_initcall(ptdump_init);