[linux-2.6-block.git] / arch / arm64 / mm / dump.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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>
 */
#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 *pmdp, unsigned long start,
		     unsigned long end)
{
	unsigned long addr = start;
	pte_t *ptep = pte_offset_kernel(pmdp, start);

	do {
		note_page(st, addr, 4, READ_ONCE(pte_val(*ptep)));
	} while (ptep++, addr += PAGE_SIZE, addr != end);
}

static void walk_pmd(struct pg_state *st, pud_t *pudp, unsigned long start,
		     unsigned long end)
{
	unsigned long next, addr = start;
	pmd_t *pmdp = pmd_offset(pudp, start);

	do {
		pmd_t pmd = READ_ONCE(*pmdp);
		next = pmd_addr_end(addr, end);

		if (pmd_none(pmd) || pmd_sect(pmd)) {
			note_page(st, addr, 3, pmd_val(pmd));
		} else {
			BUG_ON(pmd_bad(pmd));
			walk_pte(st, pmdp, addr, next);
		}
	} while (pmdp++, addr = next, addr != end);
}

static void walk_pud(struct pg_state *st, pgd_t *pgdp, unsigned long start,
		     unsigned long end)
{
	unsigned long next, addr = start;
	pud_t *pudp = pud_offset(pgdp, start);

	do {
		pud_t pud = READ_ONCE(*pudp);
		next = pud_addr_end(addr, end);

		if (pud_none(pud) || pud_sect(pud)) {
			note_page(st, addr, 2, pud_val(pud));
		} else {
			BUG_ON(pud_bad(pud));
			walk_pmd(st, pudp, addr, next);
		}
	} while (pudp++, addr = next, addr != end);
}

static void walk_pgd(struct pg_state *st, struct mm_struct *mm,
		     unsigned long start)
{
	unsigned long end = (start < TASK_SIZE_64) ? TASK_SIZE_64 : 0;
	unsigned long next, addr = start;
	pgd_t *pgdp = pgd_offset(mm, start);

	do {
		pgd_t pgd = READ_ONCE(*pgdp);
		next = pgd_addr_end(addr, end);

		if (pgd_none(pgd)) {
			note_page(st, addr, 1, pgd_val(pgd));
		} else {
			BUG_ON(pgd_bad(pgd));
			walk_pud(st, pgdp, addr, next);
		}
	} while (pgdp++, addr = next, addr != end);
}

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();
	ptdump_debugfs_register(&kernel_ptdump_info, "kernel_page_tables");
	return 0;
}
device_initcall(ptdump_init);
Commit	Line	Data
b886d83c	1	// SPDX-License-Identifier: GPL-2.0-only
c9465b4e LA	2	/*
	3	* Copyright (c) 2014, The Linux Foundation. All rights reserved.
	4	* Debug helper to dump the current kernel pagetables of the system
	5	* so that we can see what the various memory ranges are set to.
	6	*
	7	* Derived from x86 and arm implementation:
	8	* (C) Copyright 2008 Intel Corporation
	9	*
	10	* Author: Arjan van de Ven <arjan@linux.intel.com>
c9465b4e LA	11	*/
c9465b4e LA	12	#include <linux/debugfs.h>
764011ca	13	#include <linux/errno.h>
c9465b4e	14	#include <linux/fs.h>
284be285	15	#include <linux/io.h>
764011ca	16	#include <linux/init.h>
c9465b4e LA	17	#include <linux/mm.h>
	18	#include <linux/sched.h>
	19	#include <linux/seq_file.h>
	20
	21	#include <asm/fixmap.h>
d8fc68a0	22	#include <asm/kasan.h>
764011ca	23	#include <asm/memory.h>
c9465b4e	24	#include <asm/pgtable.h>
764011ca	25	#include <asm/pgtable-hwdef.h>
4674fdb9	26	#include <asm/ptdump.h>
c9465b4e	27
c8f8cca4	28	static const struct addr_marker address_markers[] = {
d8fc68a0 AB	29	#ifdef CONFIG_KASAN
	30	{ KASAN_SHADOW_START, "Kasan shadow start" },
	31	{ KASAN_SHADOW_END, "Kasan shadow end" },
	32	#endif
c8f8cca4 AB	33	{ MODULES_VADDR, "Modules start" },
c8f8cca4 AB	34	{ MODULES_END, "Modules end" },
4733c7c7 WD	35	{ VMALLOC_START, "vmalloc() area" },
4733c7c7 WD	36	{ VMALLOC_END, "vmalloc() end" },
c8f8cca4 AB	37	{ FIXADDR_START, "Fixmap start" },
	38	{ FIXADDR_TOP, "Fixmap end" },
	39	{ PCI_IO_START, "PCI I/O start" },
	40	{ PCI_IO_END, "PCI I/O end" },
3e1907d5	41	#ifdef CONFIG_SPARSEMEM_VMEMMAP
c8f8cca4 AB	42	{ VMEMMAP_START, "vmemmap start" },
c8f8cca4 AB	43	{ VMEMMAP_START + VMEMMAP_SIZE, "vmemmap end" },
3e1907d5	44	#endif
4733c7c7	45	{ PAGE_OFFSET, "Linear mapping" },
c8f8cca4	46	{ -1, NULL },
c9465b4e LA	47	};
c9465b4e LA	48
ae5d1cf3 LA	49	#define pt_dump_seq_printf(m, fmt, args...) \
	50	({ \
	51	if (m) \
	52	seq_printf(m, fmt, ##args); \
	53	})
	54
	55	#define pt_dump_seq_puts(m, fmt) \
	56	({ \
	57	if (m) \
	58	seq_printf(m, fmt); \
	59	})
	60
202e41a1 JL	61	/*
	62	* The page dumper groups page table entries of the same type into a single
	63	* description. It uses pg_state to track the range information while
	64	* iterating over the pte entries. When the continuity is broken it then
	65	* dumps out a description of the range.
	66	*/
c9465b4e LA	67	struct pg_state {
	68	struct seq_file *seq;
	69	const struct addr_marker *marker;
	70	unsigned long start_address;
	71	unsigned level;
	72	u64 current_prot;
1404d6f1 LA	73	bool check_wx;
	74	unsigned long wx_pages;
	75	unsigned long uxn_pages;
c9465b4e LA	76	};
	77
	78	struct prot_bits {
	79	u64 mask;
	80	u64 val;
	81	const char *set;
	82	const char *clear;
	83	};
	84
	85	static const struct prot_bits pte_bits[] = {
	86	{
d7e9d594 LA	87	.mask = PTE_VALID,
	88	.val = PTE_VALID,
	89	.set = " ",
	90	.clear = "F",
	91	}, {
c9465b4e LA	92	.mask = PTE_USER,
	93	.val = PTE_USER,
	94	.set = "USR",
	95	.clear = " ",
	96	}, {
	97	.mask = PTE_RDONLY,
	98	.val = PTE_RDONLY,
	99	.set = "ro",
	100	.clear = "RW",
	101	}, {
	102	.mask = PTE_PXN,
	103	.val = PTE_PXN,
	104	.set = "NX",
	105	.clear = "x ",
	106	}, {
	107	.mask = PTE_SHARED,
	108	.val = PTE_SHARED,
	109	.set = "SHD",
	110	.clear = " ",
	111	}, {
	112	.mask = PTE_AF,
	113	.val = PTE_AF,
	114	.set = "AF",
	115	.clear = " ",
	116	}, {
	117	.mask = PTE_NG,
	118	.val = PTE_NG,
	119	.set = "NG",
	120	.clear = " ",
202e41a1 JL	121	}, {
	122	.mask = PTE_CONT,
	123	.val = PTE_CONT,
	124	.set = "CON",
	125	.clear = " ",
	126	}, {
	127	.mask = PTE_TABLE_BIT,
	128	.val = PTE_TABLE_BIT,
	129	.set = " ",
	130	.clear = "BLK",
c9465b4e LA	131	}, {
	132	.mask = PTE_UXN,
	133	.val = PTE_UXN,
	134	.set = "UXN",
	135	}, {
	136	.mask = PTE_ATTRINDX_MASK,
	137	.val = PTE_ATTRINDX(MT_DEVICE_nGnRnE),
	138	.set = "DEVICE/nGnRnE",
	139	}, {
	140	.mask = PTE_ATTRINDX_MASK,
	141	.val = PTE_ATTRINDX(MT_DEVICE_nGnRE),
	142	.set = "DEVICE/nGnRE",
	143	}, {
	144	.mask = PTE_ATTRINDX_MASK,
	145	.val = PTE_ATTRINDX(MT_DEVICE_GRE),
	146	.set = "DEVICE/GRE",
	147	}, {
	148	.mask = PTE_ATTRINDX_MASK,
	149	.val = PTE_ATTRINDX(MT_NORMAL_NC),
	150	.set = "MEM/NORMAL-NC",
	151	}, {
	152	.mask = PTE_ATTRINDX_MASK,
	153	.val = PTE_ATTRINDX(MT_NORMAL),
	154	.set = "MEM/NORMAL",
	155	}
	156	};
	157
	158	struct pg_level {
	159	const struct prot_bits *bits;
48dd73c5	160	const char *name;
c9465b4e LA	161	size_t num;
	162	u64 mask;
	163	};
	164
	165	static struct pg_level pg_level[] = {
	166	{
	167	}, { /* pgd */
48dd73c5	168	.name = "PGD",
c9465b4e LA	169	.bits = pte_bits,
	170	.num = ARRAY_SIZE(pte_bits),
	171	}, { /* pud */
48dd73c5	172	.name = (CONFIG_PGTABLE_LEVELS > 3) ? "PUD" : "PGD",
c9465b4e LA	173	.bits = pte_bits,
	174	.num = ARRAY_SIZE(pte_bits),
	175	}, { /* pmd */
48dd73c5	176	.name = (CONFIG_PGTABLE_LEVELS > 2) ? "PMD" : "PGD",
c9465b4e LA	177	.bits = pte_bits,
	178	.num = ARRAY_SIZE(pte_bits),
	179	}, { /* pte */
48dd73c5	180	.name = "PTE",
c9465b4e LA	181	.bits = pte_bits,
	182	.num = ARRAY_SIZE(pte_bits),
	183	},
	184	};
	185
	186	static void dump_prot(struct pg_state st, const struct prot_bits bits,
	187	size_t num)
	188	{
	189	unsigned i;
	190
	191	for (i = 0; i < num; i++, bits++) {
	192	const char *s;
	193
	194	if ((st->current_prot & bits->mask) == bits->val)
	195	s = bits->set;
	196	else
	197	s = bits->clear;
	198
	199	if (s)
ae5d1cf3	200	pt_dump_seq_printf(st->seq, " %s", s);
c9465b4e LA	201	}
	202	}
	203
1404d6f1 LA	204	static void note_prot_uxn(struct pg_state *st, unsigned long addr)
	205	{
	206	if (!st->check_wx)
	207	return;
	208
	209	if ((st->current_prot & PTE_UXN) == PTE_UXN)
	210	return;
	211
	212	WARN_ONCE(1, "arm64/mm: Found non-UXN mapping at address %p/%pS\n",
	213	(void )st->start_address, (void )st->start_address);
	214
	215	st->uxn_pages += (addr - st->start_address) / PAGE_SIZE;
	216	}
	217
	218	static void note_prot_wx(struct pg_state *st, unsigned long addr)
	219	{
	220	if (!st->check_wx)
	221	return;
	222	if ((st->current_prot & PTE_RDONLY) == PTE_RDONLY)
	223	return;
	224	if ((st->current_prot & PTE_PXN) == PTE_PXN)
	225	return;
	226
	227	WARN_ONCE(1, "arm64/mm: Found insecure W+X mapping at address %p/%pS\n",
	228	(void )st->start_address, (void )st->start_address);
	229
	230	st->wx_pages += (addr - st->start_address) / PAGE_SIZE;
	231	}
	232
c9465b4e LA	233	static void note_page(struct pg_state *st, unsigned long addr, unsigned level,
	234	u64 val)
	235	{
	236	static const char units[] = "KMGTPE";
	237	u64 prot = val & pg_level[level].mask;
	238
c9465b4e LA	239	if (!st->level) {
	240	st->level = level;
	241	st->current_prot = prot;
	242	st->start_address = addr;
ae5d1cf3	243	pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
c9465b4e LA	244	} else if (prot != st->current_prot \|\| level != st->level \|\|
	245	addr >= st->marker[1].start_address) {
	246	const char *unit = units;
	247	unsigned long delta;
	248
	249	if (st->current_prot) {
1404d6f1 LA	250	note_prot_uxn(st, addr);
1404d6f1 LA	251	note_prot_wx(st, addr);
ae5d1cf3	252	pt_dump_seq_printf(st->seq, "0x%016lx-0x%016lx ",
c9465b4e LA	253	st->start_address, addr);
	254
	255	delta = (addr - st->start_address) >> 10;
	256	while (!(delta & 1023) && unit[1]) {
	257	delta >>= 10;
	258	unit++;
	259	}
ae5d1cf3	260	pt_dump_seq_printf(st->seq, "%9lu%c %s", delta, *unit,
48dd73c5	261	pg_level[st->level].name);
c9465b4e LA	262	if (pg_level[st->level].bits)
	263	dump_prot(st, pg_level[st->level].bits,
	264	pg_level[st->level].num);
ae5d1cf3	265	pt_dump_seq_puts(st->seq, "\n");
c9465b4e LA	266	}
	267
	268	if (addr >= st->marker[1].start_address) {
	269	st->marker++;
ae5d1cf3	270	pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
c9465b4e LA	271	}
	272
	273	st->start_address = addr;
	274	st->current_prot = prot;
	275	st->level = level;
	276	}
	277
	278	if (addr >= st->marker[1].start_address) {
	279	st->marker++;
ae5d1cf3	280	pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
c9465b4e LA	281	}
	282
	283	}
	284
d23c808c WD	285	static void walk_pte(struct pg_state st, pmd_t pmdp, unsigned long start,
d23c808c WD	286	unsigned long end)
c9465b4e	287	{
d23c808c WD	288	unsigned long addr = start;
d23c808c WD	289	pte_t *ptep = pte_offset_kernel(pmdp, start);
c9465b4e	290
d23c808c	291	do {
20a004e7	292	note_page(st, addr, 4, READ_ONCE(pte_val(*ptep)));
d23c808c	293	} while (ptep++, addr += PAGE_SIZE, addr != end);
c9465b4e LA	294	}
c9465b4e LA	295
d23c808c WD	296	static void walk_pmd(struct pg_state st, pud_t pudp, unsigned long start,
d23c808c WD	297	unsigned long end)
c9465b4e	298	{
d23c808c WD	299	unsigned long next, addr = start;
d23c808c WD	300	pmd_t *pmdp = pmd_offset(pudp, start);
c9465b4e	301
d23c808c	302	do {
20a004e7	303	pmd_t pmd = READ_ONCE(*pmdp);
d23c808c	304	next = pmd_addr_end(addr, end);
20a004e7	305
20a004e7 WD	306	if (pmd_none(pmd) \|\| pmd_sect(pmd)) {
20a004e7 WD	307	note_page(st, addr, 3, pmd_val(pmd));
a1c76574	308	} else {
20a004e7	309	BUG_ON(pmd_bad(pmd));
d23c808c	310	walk_pte(st, pmdp, addr, next);
a1c76574	311	}
d23c808c	312	} while (pmdp++, addr = next, addr != end);
c9465b4e LA	313	}
c9465b4e LA	314
d23c808c WD	315	static void walk_pud(struct pg_state st, pgd_t pgdp, unsigned long start,
d23c808c WD	316	unsigned long end)
c9465b4e	317	{
d23c808c WD	318	unsigned long next, addr = start;
d23c808c WD	319	pud_t *pudp = pud_offset(pgdp, start);
c9465b4e	320
d23c808c	321	do {
20a004e7	322	pud_t pud = READ_ONCE(*pudp);
d23c808c	323	next = pud_addr_end(addr, end);
20a004e7	324
20a004e7 WD	325	if (pud_none(pud) \|\| pud_sect(pud)) {
20a004e7 WD	326	note_page(st, addr, 2, pud_val(pud));
a1c76574	327	} else {
20a004e7	328	BUG_ON(pud_bad(pud));
d23c808c	329	walk_pmd(st, pudp, addr, next);
a1c76574	330	}
d23c808c	331	} while (pudp++, addr = next, addr != end);
c9465b4e LA	332	}
c9465b4e LA	333
4674fdb9 MR	334	static void walk_pgd(struct pg_state st, struct mm_struct mm,
4674fdb9 MR	335	unsigned long start)
c9465b4e	336	{
d23c808c WD	337	unsigned long end = (start < TASK_SIZE_64) ? TASK_SIZE_64 : 0;
	338	unsigned long next, addr = start;
	339	pgd_t *pgdp = pgd_offset(mm, start);
c9465b4e	340
d23c808c	341	do {
20a004e7	342	pgd_t pgd = READ_ONCE(*pgdp);
d23c808c	343	next = pgd_addr_end(addr, end);
20a004e7	344
20a004e7 WD	345	if (pgd_none(pgd)) {
20a004e7 WD	346	note_page(st, addr, 1, pgd_val(pgd));
a1c76574	347	} else {
20a004e7	348	BUG_ON(pgd_bad(pgd));
d23c808c	349	walk_pud(st, pgdp, addr, next);
a1c76574	350	}
d23c808c	351	} while (pgdp++, addr = next, addr != end);
c9465b4e LA	352	}
c9465b4e LA	353
4ddb9bf8	354	void ptdump_walk_pgd(struct seq_file m, struct ptdump_info info)
c9465b4e LA	355	{
	356	struct pg_state st = {
	357	.seq = m,
4674fdb9	358	.marker = info->markers,
c9465b4e LA	359	};
c9465b4e LA	360
4674fdb9	361	walk_pgd(&st, info->mm, info->base_addr);
c9465b4e LA	362
c9465b4e LA	363	note_page(&st, 0, 0, 0);
c9465b4e LA	364	}
c9465b4e LA	365
4ddb9bf8	366	static void ptdump_initialize(void)
c9465b4e	367	{
c9465b4e LA	368	unsigned i, j;
	369
	370	for (i = 0; i < ARRAY_SIZE(pg_level); i++)
	371	if (pg_level[i].bits)
	372	for (j = 0; j < pg_level[i].num; j++)
	373	pg_level[i].mask \|= pg_level[i].bits[j].mask;
c9465b4e	374	}
4674fdb9 MR	375
	376	static struct ptdump_info kernel_ptdump_info = {
	377	.mm = &init_mm,
	378	.markers = address_markers,
	379	.base_addr = VA_START,
	380	};
	381
1404d6f1 LA	382	void ptdump_check_wx(void)
	383	{
	384	struct pg_state st = {
	385	.seq = NULL,
	386	.marker = (struct addr_marker[]) {
	387	{ 0, NULL},
	388	{ -1, NULL},
	389	},
	390	.check_wx = true,
	391	};
	392
1d08a044	393	walk_pgd(&st, &init_mm, VA_START);
1404d6f1 LA	394	note_page(&st, 0, 0, 0);
	395	if (st.wx_pages \|\| st.uxn_pages)
	396	pr_warn("Checked W+X mappings: FAILED, %lu W+X pages found, %lu non-UXN pages found\n",
	397	st.wx_pages, st.uxn_pages);
	398	else
	399	pr_info("Checked W+X mappings: passed, no W+X pages found\n");
	400	}
	401
4674fdb9 MR	402	static int ptdump_init(void)
4674fdb9 MR	403	{
4ddb9bf8	404	ptdump_initialize();
e2a2e56e GKH	405	ptdump_debugfs_register(&kernel_ptdump_info, "kernel_page_tables");
e2a2e56e GKH	406	return 0;
4674fdb9	407	}
c9465b4e	408	device_initcall(ptdump_init);