[mirror_ubuntu-bionic-kernel.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>
#include <asm/ptdump.h>

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 },
};

#define pt_dump_seq_printf(m, fmt, args...)	\
({						\
	if (m)					\
		seq_printf(m, fmt, ##args);	\
})

#define pt_dump_seq_puts(m, fmt)	\
({					\
	if (m)				\
		seq_printf(m, fmt);	\
})

/*
 * 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;
	bool check_wx;
	unsigned long wx_pages;
	unsigned long uxn_pages;
};

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;
	const char *name;
	size_t num;
	u64 mask;
};

static struct pg_level pg_level[] = {
	{
	}, { /* pgd */
		.name	= "PGD",
		.bits	= pte_bits,
		.num	= ARRAY_SIZE(pte_bits),
	}, { /* pud */
		.name	= (CONFIG_PGTABLE_LEVELS > 3) ? "PUD" : "PGD",
		.bits	= pte_bits,
		.num	= ARRAY_SIZE(pte_bits),
	}, { /* pmd */
		.name	= (CONFIG_PGTABLE_LEVELS > 2) ? "PMD" : "PGD",
		.bits	= pte_bits,
		.num	= ARRAY_SIZE(pte_bits),
	}, { /* pte */
		.name	= "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)
			pt_dump_seq_printf(st->seq, " %s", s);
	}
}

static void note_prot_uxn(struct pg_state *st, unsigned long addr)
{
	if (!st->check_wx)
		return;

	if ((st->current_prot & PTE_UXN) == PTE_UXN)
		return;

	WARN_ONCE(1, "arm64/mm: Found non-UXN mapping at address %p/%pS\n",
		  (void *)st->start_address, (void *)st->start_address);

	st->uxn_pages += (addr - st->start_address) / PAGE_SIZE;
}

static void note_prot_wx(struct pg_state *st, unsigned long addr)
{
	if (!st->check_wx)
		return;
	if ((st->current_prot & PTE_RDONLY) == PTE_RDONLY)
		return;
	if ((st->current_prot & PTE_PXN) == PTE_PXN)
		return;

	WARN_ONCE(1, "arm64/mm: Found insecure W+X mapping at address %p/%pS\n",
		  (void *)st->start_address, (void *)st->start_address);

	st->wx_pages += (addr - st->start_address) / PAGE_SIZE;
}

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;
		pt_dump_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) {
			note_prot_uxn(st, addr);
			note_prot_wx(st, addr);
			pt_dump_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++;
			}
			pt_dump_seq_printf(st->seq, "%9lu%c %s", delta, *unit,
				   pg_level[st->level].name);
			if (pg_level[st->level].bits)
				dump_prot(st, pg_level[st->level].bits,
					  pg_level[st->level].num);
			pt_dump_seq_puts(st->seq, "\n");
		}

		if (addr >= st->marker[1].start_address) {
			st->marker++;
			pt_dump_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++;
		pt_dump_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, 0UL);
	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, 0UL);
	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, 0UL);
	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);
		}
	}
}

void ptdump_walk_pgd(struct seq_file *m, struct ptdump_info *info)
{
	struct pg_state st = {
		.seq = m,
		.marker = info->markers,
	};

	walk_pgd(&st, info->mm, info->base_addr);

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

static void ptdump_initialize(void)
{
	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;
}

static struct ptdump_info kernel_ptdump_info = {
	.mm		= &init_mm,
	.markers	= address_markers,
	.base_addr	= VA_START,
};

void ptdump_check_wx(void)
{
	struct pg_state st = {
		.seq = NULL,
		.marker = (struct addr_marker[]) {
			{ 0, NULL},
			{ -1, NULL},
		},
		.check_wx = true,
	};

	walk_pgd(&st, &init_mm, VA_START);
	note_page(&st, 0, 0, 0);
	if (st.wx_pages || st.uxn_pages)
		pr_warn("Checked W+X mappings: FAILED, %lu W+X pages found, %lu non-UXN pages found\n",
			st.wx_pages, st.uxn_pages);
	else
		pr_info("Checked W+X mappings: passed, no W+X pages found\n");
}

static int ptdump_init(void)
{
	ptdump_initialize();
	return ptdump_debugfs_register(&kernel_ptdump_info,
					"kernel_page_tables");
}
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>
4674fdb9	30	#include <asm/ptdump.h>
c9465b4e	31
c8f8cca4	32	static const struct addr_marker address_markers[] = {
d8fc68a0 AB	33	#ifdef CONFIG_KASAN
	34	{ KASAN_SHADOW_START, "Kasan shadow start" },
	35	{ KASAN_SHADOW_END, "Kasan shadow end" },
	36	#endif
c8f8cca4 AB	37	{ MODULES_VADDR, "Modules start" },
	38	{ MODULES_END, "Modules end" },
	39	{ VMALLOC_START, "vmalloc() Area" },
	40	{ VMALLOC_END, "vmalloc() End" },
	41	{ FIXADDR_START, "Fixmap start" },
	42	{ FIXADDR_TOP, "Fixmap end" },
	43	{ PCI_IO_START, "PCI I/O start" },
	44	{ PCI_IO_END, "PCI I/O end" },
3e1907d5	45	#ifdef CONFIG_SPARSEMEM_VMEMMAP
c8f8cca4 AB	46	{ VMEMMAP_START, "vmemmap start" },
c8f8cca4 AB	47	{ VMEMMAP_START + VMEMMAP_SIZE, "vmemmap end" },
3e1907d5	48	#endif
c8f8cca4 AB	49	{ PAGE_OFFSET, "Linear Mapping" },
c8f8cca4 AB	50	{ -1, NULL },
c9465b4e LA	51	};
c9465b4e LA	52
ae5d1cf3 LA	53	#define pt_dump_seq_printf(m, fmt, args...) \
	54	({ \
	55	if (m) \
	56	seq_printf(m, fmt, ##args); \
	57	})
	58
	59	#define pt_dump_seq_puts(m, fmt) \
	60	({ \
	61	if (m) \
	62	seq_printf(m, fmt); \
	63	})
	64
202e41a1 JL	65	/*
	66	* The page dumper groups page table entries of the same type into a single
	67	* description. It uses pg_state to track the range information while
	68	* iterating over the pte entries. When the continuity is broken it then
	69	* dumps out a description of the range.
	70	*/
c9465b4e LA	71	struct pg_state {
	72	struct seq_file *seq;
	73	const struct addr_marker *marker;
	74	unsigned long start_address;
	75	unsigned level;
	76	u64 current_prot;
1404d6f1 LA	77	bool check_wx;
	78	unsigned long wx_pages;
	79	unsigned long uxn_pages;
c9465b4e LA	80	};
	81
	82	struct prot_bits {
	83	u64 mask;
	84	u64 val;
	85	const char *set;
	86	const char *clear;
	87	};
	88
	89	static const struct prot_bits pte_bits[] = {
	90	{
d7e9d594 LA	91	.mask = PTE_VALID,
	92	.val = PTE_VALID,
	93	.set = " ",
	94	.clear = "F",
	95	}, {
c9465b4e LA	96	.mask = PTE_USER,
	97	.val = PTE_USER,
	98	.set = "USR",
	99	.clear = " ",
	100	}, {
	101	.mask = PTE_RDONLY,
	102	.val = PTE_RDONLY,
	103	.set = "ro",
	104	.clear = "RW",
	105	}, {
	106	.mask = PTE_PXN,
	107	.val = PTE_PXN,
	108	.set = "NX",
	109	.clear = "x ",
	110	}, {
	111	.mask = PTE_SHARED,
	112	.val = PTE_SHARED,
	113	.set = "SHD",
	114	.clear = " ",
	115	}, {
	116	.mask = PTE_AF,
	117	.val = PTE_AF,
	118	.set = "AF",
	119	.clear = " ",
	120	}, {
	121	.mask = PTE_NG,
	122	.val = PTE_NG,
	123	.set = "NG",
	124	.clear = " ",
202e41a1 JL	125	}, {
	126	.mask = PTE_CONT,
	127	.val = PTE_CONT,
	128	.set = "CON",
	129	.clear = " ",
	130	}, {
	131	.mask = PTE_TABLE_BIT,
	132	.val = PTE_TABLE_BIT,
	133	.set = " ",
	134	.clear = "BLK",
c9465b4e LA	135	}, {
	136	.mask = PTE_UXN,
	137	.val = PTE_UXN,
	138	.set = "UXN",
	139	}, {
	140	.mask = PTE_ATTRINDX_MASK,
	141	.val = PTE_ATTRINDX(MT_DEVICE_nGnRnE),
	142	.set = "DEVICE/nGnRnE",
	143	}, {
	144	.mask = PTE_ATTRINDX_MASK,
	145	.val = PTE_ATTRINDX(MT_DEVICE_nGnRE),
	146	.set = "DEVICE/nGnRE",
	147	}, {
	148	.mask = PTE_ATTRINDX_MASK,
	149	.val = PTE_ATTRINDX(MT_DEVICE_GRE),
	150	.set = "DEVICE/GRE",
	151	}, {
	152	.mask = PTE_ATTRINDX_MASK,
	153	.val = PTE_ATTRINDX(MT_NORMAL_NC),
	154	.set = "MEM/NORMAL-NC",
	155	}, {
	156	.mask = PTE_ATTRINDX_MASK,
	157	.val = PTE_ATTRINDX(MT_NORMAL),
	158	.set = "MEM/NORMAL",
	159	}
	160	};
	161
	162	struct pg_level {
	163	const struct prot_bits *bits;
48dd73c5	164	const char *name;
c9465b4e LA	165	size_t num;
	166	u64 mask;
	167	};
	168
	169	static struct pg_level pg_level[] = {
	170	{
	171	}, { /* pgd */
48dd73c5	172	.name = "PGD",
c9465b4e LA	173	.bits = pte_bits,
	174	.num = ARRAY_SIZE(pte_bits),
	175	}, { /* pud */
48dd73c5	176	.name = (CONFIG_PGTABLE_LEVELS > 3) ? "PUD" : "PGD",
c9465b4e LA	177	.bits = pte_bits,
	178	.num = ARRAY_SIZE(pte_bits),
	179	}, { /* pmd */
48dd73c5	180	.name = (CONFIG_PGTABLE_LEVELS > 2) ? "PMD" : "PGD",
c9465b4e LA	181	.bits = pte_bits,
	182	.num = ARRAY_SIZE(pte_bits),
	183	}, { /* pte */
48dd73c5	184	.name = "PTE",
c9465b4e LA	185	.bits = pte_bits,
	186	.num = ARRAY_SIZE(pte_bits),
	187	},
	188	};
	189
	190	static void dump_prot(struct pg_state st, const struct prot_bits bits,
	191	size_t num)
	192	{
	193	unsigned i;
	194
	195	for (i = 0; i < num; i++, bits++) {
	196	const char *s;
	197
	198	if ((st->current_prot & bits->mask) == bits->val)
	199	s = bits->set;
	200	else
	201	s = bits->clear;
	202
	203	if (s)
ae5d1cf3	204	pt_dump_seq_printf(st->seq, " %s", s);
c9465b4e LA	205	}
	206	}
	207
1404d6f1 LA	208	static void note_prot_uxn(struct pg_state *st, unsigned long addr)
	209	{
	210	if (!st->check_wx)
	211	return;
	212
	213	if ((st->current_prot & PTE_UXN) == PTE_UXN)
	214	return;
	215
	216	WARN_ONCE(1, "arm64/mm: Found non-UXN mapping at address %p/%pS\n",
	217	(void )st->start_address, (void )st->start_address);
	218
	219	st->uxn_pages += (addr - st->start_address) / PAGE_SIZE;
	220	}
	221
	222	static void note_prot_wx(struct pg_state *st, unsigned long addr)
	223	{
	224	if (!st->check_wx)
	225	return;
	226	if ((st->current_prot & PTE_RDONLY) == PTE_RDONLY)
	227	return;
	228	if ((st->current_prot & PTE_PXN) == PTE_PXN)
	229	return;
	230
	231	WARN_ONCE(1, "arm64/mm: Found insecure W+X mapping at address %p/%pS\n",
	232	(void )st->start_address, (void )st->start_address);
	233
	234	st->wx_pages += (addr - st->start_address) / PAGE_SIZE;
	235	}
	236
c9465b4e LA	237	static void note_page(struct pg_state *st, unsigned long addr, unsigned level,
	238	u64 val)
	239	{
	240	static const char units[] = "KMGTPE";
	241	u64 prot = val & pg_level[level].mask;
	242
c9465b4e LA	243	if (!st->level) {
	244	st->level = level;
	245	st->current_prot = prot;
	246	st->start_address = addr;
ae5d1cf3	247	pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
c9465b4e LA	248	} else if (prot != st->current_prot \|\| level != st->level \|\|
	249	addr >= st->marker[1].start_address) {
	250	const char *unit = units;
	251	unsigned long delta;
	252
	253	if (st->current_prot) {
1404d6f1 LA	254	note_prot_uxn(st, addr);
1404d6f1 LA	255	note_prot_wx(st, addr);
ae5d1cf3	256	pt_dump_seq_printf(st->seq, "0x%016lx-0x%016lx ",
c9465b4e LA	257	st->start_address, addr);
	258
	259	delta = (addr - st->start_address) >> 10;
	260	while (!(delta & 1023) && unit[1]) {
	261	delta >>= 10;
	262	unit++;
	263	}
ae5d1cf3	264	pt_dump_seq_printf(st->seq, "%9lu%c %s", delta, *unit,
48dd73c5	265	pg_level[st->level].name);
c9465b4e LA	266	if (pg_level[st->level].bits)
	267	dump_prot(st, pg_level[st->level].bits,
	268	pg_level[st->level].num);
ae5d1cf3	269	pt_dump_seq_puts(st->seq, "\n");
c9465b4e LA	270	}
	271
	272	if (addr >= st->marker[1].start_address) {
	273	st->marker++;
ae5d1cf3	274	pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
c9465b4e LA	275	}
	276
	277	st->start_address = addr;
	278	st->current_prot = prot;
	279	st->level = level;
	280	}
	281
	282	if (addr >= st->marker[1].start_address) {
	283	st->marker++;
ae5d1cf3	284	pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
c9465b4e LA	285	}
	286
	287	}
	288
	289	static void walk_pte(struct pg_state st, pmd_t pmd, unsigned long start)
	290	{
a93a4d62	291	pte_t *pte = pte_offset_kernel(pmd, 0UL);
c9465b4e LA	292	unsigned long addr;
	293	unsigned i;
	294
	295	for (i = 0; i < PTRS_PER_PTE; i++, pte++) {
	296	addr = start + i * PAGE_SIZE;
	297	note_page(st, addr, 4, pte_val(*pte));
	298	}
	299	}
	300
	301	static void walk_pmd(struct pg_state st, pud_t pud, unsigned long start)
	302	{
a93a4d62	303	pmd_t *pmd = pmd_offset(pud, 0UL);
c9465b4e LA	304	unsigned long addr;
	305	unsigned i;
	306
	307	for (i = 0; i < PTRS_PER_PMD; i++, pmd++) {
	308	addr = start + i * PMD_SIZE;
a1c76574	309	if (pmd_none(pmd) \|\| pmd_sect(pmd)) {
c9465b4e	310	note_page(st, addr, 3, pmd_val(*pmd));
a1c76574 MR	311	} else {
a1c76574 MR	312	BUG_ON(pmd_bad(*pmd));
c9465b4e	313	walk_pte(st, pmd, addr);
a1c76574	314	}
c9465b4e LA	315	}
	316	}
	317
	318	static void walk_pud(struct pg_state st, pgd_t pgd, unsigned long start)
	319	{
a93a4d62	320	pud_t *pud = pud_offset(pgd, 0UL);
c9465b4e LA	321	unsigned long addr;
	322	unsigned i;
	323
	324	for (i = 0; i < PTRS_PER_PUD; i++, pud++) {
	325	addr = start + i * PUD_SIZE;
a1c76574	326	if (pud_none(pud) \|\| pud_sect(pud)) {
c9465b4e	327	note_page(st, addr, 2, pud_val(*pud));
a1c76574 MR	328	} else {
a1c76574 MR	329	BUG_ON(pud_bad(*pud));
c9465b4e	330	walk_pmd(st, pud, addr);
a1c76574	331	}
c9465b4e LA	332	}
	333	}
	334
4674fdb9 MR	335	static void walk_pgd(struct pg_state st, struct mm_struct mm,
4674fdb9 MR	336	unsigned long start)
c9465b4e	337	{
35545f0c	338	pgd_t *pgd = pgd_offset(mm, 0UL);
c9465b4e LA	339	unsigned i;
	340	unsigned long addr;
	341
	342	for (i = 0; i < PTRS_PER_PGD; i++, pgd++) {
	343	addr = start + i * PGDIR_SIZE;
a1c76574	344	if (pgd_none(*pgd)) {
c9465b4e	345	note_page(st, addr, 1, pgd_val(*pgd));
a1c76574 MR	346	} else {
a1c76574 MR	347	BUG_ON(pgd_bad(*pgd));
c9465b4e	348	walk_pud(st, pgd, addr);
a1c76574	349	}
c9465b4e LA	350	}
	351	}
	352
4ddb9bf8	353	void ptdump_walk_pgd(struct seq_file m, struct ptdump_info info)
c9465b4e LA	354	{
	355	struct pg_state st = {
	356	.seq = m,
4674fdb9	357	.marker = info->markers,
c9465b4e LA	358	};
c9465b4e LA	359
4674fdb9	360	walk_pgd(&st, info->mm, info->base_addr);
c9465b4e LA	361
c9465b4e LA	362	note_page(&st, 0, 0, 0);
c9465b4e LA	363	}
c9465b4e LA	364
4ddb9bf8	365	static void ptdump_initialize(void)
c9465b4e	366	{
c9465b4e LA	367	unsigned i, j;
	368
	369	for (i = 0; i < ARRAY_SIZE(pg_level); i++)
	370	if (pg_level[i].bits)
	371	for (j = 0; j < pg_level[i].num; j++)
	372	pg_level[i].mask \|= pg_level[i].bits[j].mask;
c9465b4e	373	}
4674fdb9 MR	374
	375	static struct ptdump_info kernel_ptdump_info = {
	376	.mm = &init_mm,
	377	.markers = address_markers,
	378	.base_addr = VA_START,
	379	};
	380
1404d6f1 LA	381	void ptdump_check_wx(void)
	382	{
	383	struct pg_state st = {
	384	.seq = NULL,
	385	.marker = (struct addr_marker[]) {
	386	{ 0, NULL},
	387	{ -1, NULL},
	388	},
	389	.check_wx = true,
	390	};
	391
1d08a044	392	walk_pgd(&st, &init_mm, VA_START);
1404d6f1 LA	393	note_page(&st, 0, 0, 0);
	394	if (st.wx_pages \|\| st.uxn_pages)
	395	pr_warn("Checked W+X mappings: FAILED, %lu W+X pages found, %lu non-UXN pages found\n",
	396	st.wx_pages, st.uxn_pages);
	397	else
	398	pr_info("Checked W+X mappings: passed, no W+X pages found\n");
	399	}
	400
4674fdb9 MR	401	static int ptdump_init(void)
4674fdb9 MR	402	{
4ddb9bf8 LA	403	ptdump_initialize();
	404	return ptdump_debugfs_register(&kernel_ptdump_info,
	405	"kernel_page_tables");
4674fdb9	406	}
c9465b4e	407	device_initcall(ptdump_init);