[linux-2.6-block.git] / arch / powerpc / mm / ptdump / ptdump.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2016, Rashmica Gupta, IBM Corp.
 *
 * This traverses the kernel pagetables and dumps the
 * information about the used sections of memory to
 * /sys/kernel/debug/kernel_pagetables.
 *
 * Derived from the arm64 implementation:
 * Copyright (c) 2014, The Linux Foundation, Laura Abbott.
 * (C) Copyright 2008 Intel Corporation, Arjan van de Ven.
 */
#include <linux/debugfs.h>
#include <linux/fs.h>
#include <linux/hugetlb.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <asm/fixmap.h>
#include <asm/pgtable.h>
#include <linux/const.h>
#include <asm/page.h>
#include <asm/pgalloc.h>

#include <mm/mmu_decl.h>

#include "ptdump.h"

/*
 * To visualise what is happening,
 *
 *  - PTRS_PER_P** = how many entries there are in the corresponding P**
 *  - P**_SHIFT = how many bits of the address we use to index into the
 * corresponding P**
 *  - P**_SIZE is how much memory we can access through the table - not the
 * size of the table itself.
 * P**={PGD, PUD, PMD, PTE}
 *
 *
 * Each entry of the PGD points to a PUD. Each entry of a PUD points to a
 * PMD. Each entry of a PMD points to a PTE. And every PTE entry points to
 * a page.
 *
 * In the case where there are only 3 levels, the PUD is folded into the
 * PGD: every PUD has only one entry which points to the PMD.
 *
 * 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 - ie PTEs that are virtually contiguous
 * with the same PTE flags are chunked together. This is to make it clear how
 * different areas of the kernel virtual memory are used.
 *
 */
struct pg_state {
	struct seq_file *seq;
	const struct addr_marker *marker;
	unsigned long start_address;
	unsigned long start_pa;
	unsigned long last_pa;
	unsigned int level;
	u64 current_flags;
	bool check_wx;
	unsigned long wx_pages;
};

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

static struct addr_marker address_markers[] = {
	{ 0,	"Start of kernel VM" },
	{ 0,	"vmalloc() Area" },
	{ 0,	"vmalloc() End" },
#ifdef CONFIG_PPC64
	{ 0,	"isa I/O start" },
	{ 0,	"isa I/O end" },
	{ 0,	"phb I/O start" },
	{ 0,	"phb I/O end" },
	{ 0,	"I/O remap start" },
	{ 0,	"I/O remap end" },
	{ 0,	"vmemmap start" },
#else
	{ 0,	"Early I/O remap start" },
	{ 0,	"Early I/O remap end" },
#ifdef CONFIG_HIGHMEM
	{ 0,	"Highmem PTEs start" },
	{ 0,	"Highmem PTEs end" },
#endif
	{ 0,	"Fixmap start" },
	{ 0,	"Fixmap end" },
#endif
#ifdef CONFIG_KASAN
	{ 0,	"kasan shadow mem start" },
	{ 0,	"kasan shadow mem end" },
#endif
	{ -1,	NULL },
};

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

#define pt_dump_seq_putc(m, c)		\
({					\
	if (m)				\
		seq_putc(m, c);		\
})

static void dump_flag_info(struct pg_state *st, const struct flag_info
		*flag, u64 pte, int num)
{
	unsigned int i;

	for (i = 0; i < num; i++, flag++) {
		const char *s = NULL;
		u64 val;

		/* flag not defined so don't check it */
		if (flag->mask == 0)
			continue;
		/* Some 'flags' are actually values */
		if (flag->is_val) {
			val = pte & flag->val;
			if (flag->shift)
				val = val >> flag->shift;
			pt_dump_seq_printf(st->seq, "  %s:%llx", flag->set, val);
		} else {
			if ((pte & flag->mask) == flag->val)
				s = flag->set;
			else
				s = flag->clear;
			if (s)
				pt_dump_seq_printf(st->seq, "  %s", s);
		}
		st->current_flags &= ~flag->mask;
	}
	if (st->current_flags != 0)
		pt_dump_seq_printf(st->seq, "  unknown flags:%llx", st->current_flags);
}

static void dump_addr(struct pg_state *st, unsigned long addr)
{
	static const char units[] = "KMGTPE";
	const char *unit = units;
	unsigned long delta;

#ifdef CONFIG_PPC64
#define REG		"0x%016lx"
#else
#define REG		"0x%08lx"
#endif

	pt_dump_seq_printf(st->seq, REG "-" REG " ", st->start_address, addr - 1);
	if (st->start_pa == st->last_pa && st->start_address + PAGE_SIZE != addr) {
		pt_dump_seq_printf(st->seq, "[" REG "]", st->start_pa);
		delta = PAGE_SIZE >> 10;
	} else {
		pt_dump_seq_printf(st->seq, " " REG " ", st->start_pa);
		delta = (addr - st->start_address) >> 10;
	}
	/* Work out what appropriate unit to use */
	while (!(delta & 1023) && unit[1]) {
		delta >>= 10;
		unit++;
	}
	pt_dump_seq_printf(st->seq, "%9lu%c", delta, *unit);

}

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

	if (!((st->current_flags & pgprot_val(PAGE_KERNEL_X)) == pgprot_val(PAGE_KERNEL_X)))
		return;

	WARN_ONCE(1, "powerpc/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 int level, u64 val)
{
	u64 flag = val & pg_level[level].mask;
	u64 pa = val & PTE_RPN_MASK;

	/* At first no level is set */
	if (!st->level) {
		st->level = level;
		st->current_flags = flag;
		st->start_address = addr;
		st->start_pa = pa;
		st->last_pa = pa;
		pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
	/*
	 * Dump the section of virtual memory when:
	 *   - the PTE flags from one entry to the next differs.
	 *   - we change levels in the tree.
	 *   - the address is in a different section of memory and is thus
	 *   used for a different purpose, regardless of the flags.
	 *   - the pa of this page is not adjacent to the last inspected page
	 */
	} else if (flag != st->current_flags || level != st->level ||
		   addr >= st->marker[1].start_address ||
		   (pa != st->last_pa + PAGE_SIZE &&
		    (pa != st->start_pa || st->start_pa != st->last_pa))) {

		/* Check the PTE flags */
		if (st->current_flags) {
			note_prot_wx(st, addr);
			dump_addr(st, addr);

			/* Dump all the flags */
			if (pg_level[st->level].flag)
				dump_flag_info(st, pg_level[st->level].flag,
					  st->current_flags,
					  pg_level[st->level].num);

			pt_dump_seq_putc(st->seq, '\n');
		}

		/*
		 * Address indicates we have passed the end of the
		 * current section of virtual memory
		 */
		while (addr >= st->marker[1].start_address) {
			st->marker++;
			pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
		}
		st->start_address = addr;
		st->start_pa = pa;
		st->last_pa = pa;
		st->current_flags = flag;
		st->level = level;
	} else {
		st->last_pa = pa;
	}
}

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 int 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 int i;

	for (i = 0; i < PTRS_PER_PMD; i++, pmd++) {
		addr = start + i * PMD_SIZE;
		if (!pmd_none(*pmd) && !pmd_is_leaf(*pmd))
			/* pmd exists */
			walk_pte(st, pmd, addr);
		else
			note_page(st, addr, 3, pmd_val(*pmd));
	}
}

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 int i;

	for (i = 0; i < PTRS_PER_PUD; i++, pud++) {
		addr = start + i * PUD_SIZE;
		if (!pud_none(*pud) && !pud_is_leaf(*pud))
			/* pud exists */
			walk_pmd(st, pud, addr);
		else
			note_page(st, addr, 2, pud_val(*pud));
	}
}

static void walk_pagetables(struct pg_state *st)
{
	unsigned int i;
	unsigned long addr = st->start_address & PGDIR_MASK;
	pgd_t *pgd = pgd_offset_k(addr);

	/*
	 * Traverse the linux pagetable structure and dump pages that are in
	 * the hash pagetable.
	 */
	for (i = pgd_index(addr); i < PTRS_PER_PGD; i++, pgd++, addr += PGDIR_SIZE) {
		if (!pgd_none(*pgd) && !pgd_is_leaf(*pgd))
			/* pgd exists */
			walk_pud(st, pgd, addr);
		else
			note_page(st, addr, 1, pgd_val(*pgd));
	}
}

static void populate_markers(void)
{
	int i = 0;

	address_markers[i++].start_address = PAGE_OFFSET;
	address_markers[i++].start_address = VMALLOC_START;
	address_markers[i++].start_address = VMALLOC_END;
#ifdef CONFIG_PPC64
	address_markers[i++].start_address = ISA_IO_BASE;
	address_markers[i++].start_address = ISA_IO_END;
	address_markers[i++].start_address = PHB_IO_BASE;
	address_markers[i++].start_address = PHB_IO_END;
	address_markers[i++].start_address = IOREMAP_BASE;
	address_markers[i++].start_address = IOREMAP_END;
	/* What is the ifdef about? */
#ifdef CONFIG_PPC_BOOK3S_64
	address_markers[i++].start_address =  H_VMEMMAP_START;
#else
	address_markers[i++].start_address =  VMEMMAP_BASE;
#endif
#else /* !CONFIG_PPC64 */
	address_markers[i++].start_address = ioremap_bot;
	address_markers[i++].start_address = IOREMAP_TOP;
#ifdef CONFIG_HIGHMEM
	address_markers[i++].start_address = PKMAP_BASE;
	address_markers[i++].start_address = PKMAP_ADDR(LAST_PKMAP);
#endif
	address_markers[i++].start_address = FIXADDR_START;
	address_markers[i++].start_address = FIXADDR_TOP;
#ifdef CONFIG_KASAN
	address_markers[i++].start_address = KASAN_SHADOW_START;
	address_markers[i++].start_address = KASAN_SHADOW_END;
#endif
#endif /* CONFIG_PPC64 */
}

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

#ifdef CONFIG_PPC64
	if (!radix_enabled())
		st.start_address = KERN_VIRT_START;
#endif

	/* Traverse kernel page tables */
	walk_pagetables(&st);
	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 void build_pgtable_complete_mask(void)
{
	unsigned int i, j;

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

#ifdef CONFIG_PPC_DEBUG_WX
void ptdump_check_wx(void)
{
	struct pg_state st = {
		.seq = NULL,
		.marker = address_markers,
		.check_wx = true,
		.start_address = PAGE_OFFSET,
	};

#ifdef CONFIG_PPC64
	if (!radix_enabled())
		st.start_address = KERN_VIRT_START;
#endif

	walk_pagetables(&st);

	if (st.wx_pages)
		pr_warn("Checked W+X mappings: FAILED, %lu W+X pages found\n",
			st.wx_pages);
	else
		pr_info("Checked W+X mappings: passed, no W+X pages found\n");
}
#endif

static int ptdump_init(void)
{
	struct dentry *debugfs_file;

	populate_markers();
	build_pgtable_complete_mask();
	debugfs_file = debugfs_create_file("kernel_page_tables", 0400, NULL,
			NULL, &ptdump_fops);
	return debugfs_file ? 0 : -ENOMEM;
}
device_initcall(ptdump_init);
Commit	Line	Data
b886d83c	1	// SPDX-License-Identifier: GPL-2.0-only
8eb07b18 RG	2	/*
	3	* Copyright 2016, Rashmica Gupta, IBM Corp.
	4	*
	5	* This traverses the kernel pagetables and dumps the
	6	* information about the used sections of memory to
	7	* /sys/kernel/debug/kernel_pagetables.
	8	*
	9	* Derived from the arm64 implementation:
	10	* Copyright (c) 2014, The Linux Foundation, Laura Abbott.
	11	* (C) Copyright 2008 Intel Corporation, Arjan van de Ven.
8eb07b18 RG	12	*/
	13	#include <linux/debugfs.h>
	14	#include <linux/fs.h>
bfb9956a	15	#include <linux/hugetlb.h>
8eb07b18 RG	16	#include <linux/io.h>
8eb07b18 RG	17	#include <linux/mm.h>
462951cd	18	#include <linux/highmem.h>
8eb07b18 RG	19	#include <linux/sched.h>
	20	#include <linux/seq_file.h>
	21	#include <asm/fixmap.h>
	22	#include <asm/pgtable.h>
	23	#include <linux/const.h>
	24	#include <asm/page.h>
	25	#include <asm/pgalloc.h>
	26
1e1c8b2c CL	27	#include <mm/mmu_decl.h>
1e1c8b2c CL	28
e66c3209	29	#include "ptdump.h"
97026b5a	30
8eb07b18 RG	31	/*
	32	* To visualise what is happening,
	33	*
	34	* - PTRS_PER_P = how many entries there are in the corresponding P
	35	* - P**_SHIFT = how many bits of the address we use to index into the
	36	* corresponding P**
	37	* - P**_SIZE is how much memory we can access through the table - not the
	38	* size of the table itself.
	39	* P**={PGD, PUD, PMD, PTE}
	40	*
	41	*
	42	* Each entry of the PGD points to a PUD. Each entry of a PUD points to a
	43	* PMD. Each entry of a PMD points to a PTE. And every PTE entry points to
	44	* a page.
	45	*
	46	* In the case where there are only 3 levels, the PUD is folded into the
	47	* PGD: every PUD has only one entry which points to the PMD.
	48	*
	49	* The page dumper groups page table entries of the same type into a single
	50	* description. It uses pg_state to track the range information while
	51	* iterating over the PTE entries. When the continuity is broken it then
	52	* dumps out a description of the range - ie PTEs that are virtually contiguous
	53	* with the same PTE flags are chunked together. This is to make it clear how
	54	* different areas of the kernel virtual memory are used.
	55	*
	56	*/
	57	struct pg_state {
	58	struct seq_file *seq;
	59	const struct addr_marker *marker;
	60	unsigned long start_address;
aaa22952 OH	61	unsigned long start_pa;
aaa22952 OH	62	unsigned long last_pa;
8eb07b18 RG	63	unsigned int level;
8eb07b18 RG	64	u64 current_flags;
453d87f6 RC	65	bool check_wx;
453d87f6 RC	66	unsigned long wx_pages;
8eb07b18 RG	67	};
	68
	69	struct addr_marker {
	70	unsigned long start_address;
	71	const char *name;
	72	};
	73
	74	static struct addr_marker address_markers[] = {
	75	{ 0, "Start of kernel VM" },
	76	{ 0, "vmalloc() Area" },
	77	{ 0, "vmalloc() End" },
6c01bbd2	78	#ifdef CONFIG_PPC64
8eb07b18 RG	79	{ 0, "isa I/O start" },
	80	{ 0, "isa I/O end" },
	81	{ 0, "phb I/O start" },
	82	{ 0, "phb I/O end" },
	83	{ 0, "I/O remap start" },
	84	{ 0, "I/O remap end" },
	85	{ 0, "vmemmap start" },
6c01bbd2 CL	86	#else
	87	{ 0, "Early I/O remap start" },
	88	{ 0, "Early I/O remap end" },
6c01bbd2 CL	89	#ifdef CONFIG_HIGHMEM
	90	{ 0, "Highmem PTEs start" },
	91	{ 0, "Highmem PTEs end" },
	92	#endif
	93	{ 0, "Fixmap start" },
	94	{ 0, "Fixmap end" },
b4abe38f CL	95	#endif
	96	#ifdef CONFIG_KASAN
	97	{ 0, "kasan shadow mem start" },
	98	{ 0, "kasan shadow mem end" },
6c01bbd2	99	#endif
8eb07b18 RG	100	{ -1, NULL },
	101	};
	102
5f18cbdb RC	103	#define pt_dump_seq_printf(m, fmt, args...) \
	104	({ \
	105	if (m) \
	106	seq_printf(m, fmt, ##args); \
	107	})
	108
	109	#define pt_dump_seq_putc(m, c) \
	110	({ \
	111	if (m) \
	112	seq_putc(m, c); \
	113	})
	114
8eb07b18 RG	115	static void dump_flag_info(struct pg_state *st, const struct flag_info
	116	*flag, u64 pte, int num)
	117	{
	118	unsigned int i;
	119
	120	for (i = 0; i < num; i++, flag++) {
	121	const char *s = NULL;
	122	u64 val;
	123
	124	/* flag not defined so don't check it */
	125	if (flag->mask == 0)
	126	continue;
	127	/* Some 'flags' are actually values */
	128	if (flag->is_val) {
	129	val = pte & flag->val;
	130	if (flag->shift)
	131	val = val >> flag->shift;
5f18cbdb	132	pt_dump_seq_printf(st->seq, " %s:%llx", flag->set, val);
8eb07b18 RG	133	} else {
	134	if ((pte & flag->mask) == flag->val)
	135	s = flag->set;
	136	else
	137	s = flag->clear;
	138	if (s)
5f18cbdb	139	pt_dump_seq_printf(st->seq, " %s", s);
8eb07b18 RG	140	}
	141	st->current_flags &= ~flag->mask;
	142	}
	143	if (st->current_flags != 0)
5f18cbdb	144	pt_dump_seq_printf(st->seq, " unknown flags:%llx", st->current_flags);
8eb07b18 RG	145	}
	146
	147	static void dump_addr(struct pg_state *st, unsigned long addr)
	148	{
	149	static const char units[] = "KMGTPE";
	150	const char *unit = units;
	151	unsigned long delta;
	152
78a18dbf	153	#ifdef CONFIG_PPC64
cabe8138	154	#define REG "0x%016lx"
78a18dbf	155	#else
cabe8138	156	#define REG "0x%08lx"
78a18dbf	157	#endif
aaa22952	158
5f18cbdb	159	pt_dump_seq_printf(st->seq, REG "-" REG " ", st->start_address, addr - 1);
cabe8138	160	if (st->start_pa == st->last_pa && st->start_address + PAGE_SIZE != addr) {
5f18cbdb	161	pt_dump_seq_printf(st->seq, "[" REG "]", st->start_pa);
cabe8138 CL	162	delta = PAGE_SIZE >> 10;
cabe8138 CL	163	} else {
5f18cbdb	164	pt_dump_seq_printf(st->seq, " " REG " ", st->start_pa);
cabe8138 CL	165	delta = (addr - st->start_address) >> 10;
cabe8138 CL	166	}
8eb07b18 RG	167	/* Work out what appropriate unit to use */
	168	while (!(delta & 1023) && unit[1]) {
	169	delta >>= 10;
	170	unit++;
	171	}
5f18cbdb	172	pt_dump_seq_printf(st->seq, "%9lu%c", delta, *unit);
8eb07b18 RG	173
	174	}
	175
453d87f6 RC	176	static void note_prot_wx(struct pg_state *st, unsigned long addr)
453d87f6 RC	177	{
f3a2ac05	178	if (!IS_ENABLED(CONFIG_PPC_DEBUG_WX) \|\| !st->check_wx)
453d87f6 RC	179	return;
	180
	181	if (!((st->current_flags & pgprot_val(PAGE_KERNEL_X)) == pgprot_val(PAGE_KERNEL_X)))
	182	return;
	183
	184	WARN_ONCE(1, "powerpc/mm: Found insecure W+X mapping at address %p/%pS\n",
	185	(void )st->start_address, (void )st->start_address);
	186
	187	st->wx_pages += (addr - st->start_address) / PAGE_SIZE;
	188	}
	189
8eb07b18 RG	190	static void note_page(struct pg_state *st, unsigned long addr,
	191	unsigned int level, u64 val)
	192	{
	193	u64 flag = val & pg_level[level].mask;
aaa22952 OH	194	u64 pa = val & PTE_RPN_MASK;
aaa22952 OH	195
8eb07b18 RG	196	/* At first no level is set */
	197	if (!st->level) {
	198	st->level = level;
	199	st->current_flags = flag;
	200	st->start_address = addr;
aaa22952 OH	201	st->start_pa = pa;
aaa22952 OH	202	st->last_pa = pa;
5f18cbdb	203	pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
8eb07b18 RG	204	/*
	205	* Dump the section of virtual memory when:
	206	* - the PTE flags from one entry to the next differs.
	207	* - we change levels in the tree.
	208	* - the address is in a different section of memory and is thus
	209	* used for a different purpose, regardless of the flags.
aaa22952	210	* - the pa of this page is not adjacent to the last inspected page
8eb07b18 RG	211	*/
8eb07b18 RG	212	} else if (flag != st->current_flags \|\| level != st->level \|\|
aaa22952	213	addr >= st->marker[1].start_address \|\|
cabe8138 CL	214	(pa != st->last_pa + PAGE_SIZE &&
cabe8138 CL	215	(pa != st->start_pa \|\| st->start_pa != st->last_pa))) {
8eb07b18 RG	216
	217	/* Check the PTE flags */
	218	if (st->current_flags) {
453d87f6	219	note_prot_wx(st, addr);
8eb07b18 RG	220	dump_addr(st, addr);
	221
	222	/* Dump all the flags */
	223	if (pg_level[st->level].flag)
	224	dump_flag_info(st, pg_level[st->level].flag,
	225	st->current_flags,
	226	pg_level[st->level].num);
	227
5f18cbdb	228	pt_dump_seq_putc(st->seq, '\n');
8eb07b18 RG	229	}
	230
	231	/*
	232	* Address indicates we have passed the end of the
	233	* current section of virtual memory
	234	*/
	235	while (addr >= st->marker[1].start_address) {
	236	st->marker++;
5f18cbdb	237	pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
8eb07b18 RG	238	}
8eb07b18 RG	239	st->start_address = addr;
aaa22952 OH	240	st->start_pa = pa;
aaa22952 OH	241	st->last_pa = pa;
8eb07b18 RG	242	st->current_flags = flag;
8eb07b18 RG	243	st->level = level;
aaa22952 OH	244	} else {
aaa22952 OH	245	st->last_pa = pa;
8eb07b18 RG	246	}
	247	}
	248
	249	static void walk_pte(struct pg_state st, pmd_t pmd, unsigned long start)
	250	{
	251	pte_t *pte = pte_offset_kernel(pmd, 0);
	252	unsigned long addr;
	253	unsigned int i;
	254
	255	for (i = 0; i < PTRS_PER_PTE; i++, pte++) {
	256	addr = start + i * PAGE_SIZE;
	257	note_page(st, addr, 4, pte_val(*pte));
	258
	259	}
	260	}
	261
	262	static void walk_pmd(struct pg_state st, pud_t pud, unsigned long start)
	263	{
	264	pmd_t *pmd = pmd_offset(pud, 0);
	265	unsigned long addr;
	266	unsigned int i;
	267
	268	for (i = 0; i < PTRS_PER_PMD; i++, pmd++) {
	269	addr = start + i * PMD_SIZE;
d6eacedd	270	if (!pmd_none(pmd) && !pmd_is_leaf(pmd))
8eb07b18 RG	271	/* pmd exists */
	272	walk_pte(st, pmd, addr);
	273	else
	274	note_page(st, addr, 3, pmd_val(*pmd));
	275	}
	276	}
	277
	278	static void walk_pud(struct pg_state st, pgd_t pgd, unsigned long start)
	279	{
	280	pud_t *pud = pud_offset(pgd, 0);
	281	unsigned long addr;
	282	unsigned int i;
	283
	284	for (i = 0; i < PTRS_PER_PUD; i++, pud++) {
	285	addr = start + i * PUD_SIZE;
d6eacedd	286	if (!pud_none(pud) && !pud_is_leaf(pud))
8eb07b18 RG	287	/* pud exists */
	288	walk_pmd(st, pud, addr);
	289	else
	290	note_page(st, addr, 2, pud_val(*pud));
	291	}
	292	}
	293
	294	static void walk_pagetables(struct pg_state *st)
	295	{
8eb07b18	296	unsigned int i;
e033829d CL	297	unsigned long addr = st->start_address & PGDIR_MASK;
e033829d CL	298	pgd_t *pgd = pgd_offset_k(addr);
0d923962	299
8eb07b18 RG	300	/*
	301	* Traverse the linux pagetable structure and dump pages that are in
	302	* the hash pagetable.
	303	*/
e033829d	304	for (i = pgd_index(addr); i < PTRS_PER_PGD; i++, pgd++, addr += PGDIR_SIZE) {
d6eacedd	305	if (!pgd_none(pgd) && !pgd_is_leaf(pgd))
8eb07b18 RG	306	/* pgd exists */
	307	walk_pud(st, pgd, addr);
	308	else
	309	note_page(st, addr, 1, pgd_val(*pgd));
	310	}
	311	}
	312
	313	static void populate_markers(void)
	314	{
6c01bbd2 CL	315	int i = 0;
	316
	317	address_markers[i++].start_address = PAGE_OFFSET;
	318	address_markers[i++].start_address = VMALLOC_START;
	319	address_markers[i++].start_address = VMALLOC_END;
	320	#ifdef CONFIG_PPC64
	321	address_markers[i++].start_address = ISA_IO_BASE;
	322	address_markers[i++].start_address = ISA_IO_END;
	323	address_markers[i++].start_address = PHB_IO_BASE;
	324	address_markers[i++].start_address = PHB_IO_END;
	325	address_markers[i++].start_address = IOREMAP_BASE;
	326	address_markers[i++].start_address = IOREMAP_END;
0034d395	327	/* What is the ifdef about? */
4e003747	328	#ifdef CONFIG_PPC_BOOK3S_64
0034d395	329	address_markers[i++].start_address = H_VMEMMAP_START;
8eb07b18	330	#else
6c01bbd2 CL	331	address_markers[i++].start_address = VMEMMAP_BASE;
	332	#endif
	333	#else /* !CONFIG_PPC64 */
	334	address_markers[i++].start_address = ioremap_bot;
	335	address_markers[i++].start_address = IOREMAP_TOP;
6c01bbd2 CL	336	#ifdef CONFIG_HIGHMEM
	337	address_markers[i++].start_address = PKMAP_BASE;
	338	address_markers[i++].start_address = PKMAP_ADDR(LAST_PKMAP);
8eb07b18	339	#endif
6c01bbd2 CL	340	address_markers[i++].start_address = FIXADDR_START;
6c01bbd2 CL	341	address_markers[i++].start_address = FIXADDR_TOP;
b4abe38f CL	342	#ifdef CONFIG_KASAN
	343	address_markers[i++].start_address = KASAN_SHADOW_START;
	344	address_markers[i++].start_address = KASAN_SHADOW_END;
	345	#endif
6c01bbd2	346	#endif /* CONFIG_PPC64 */
8eb07b18 RG	347	}
	348
	349	static int ptdump_show(struct seq_file m, void v)
	350	{
	351	struct pg_state st = {
	352	.seq = m,
8eb07b18	353	.marker = address_markers,
82242352	354	.start_address = PAGE_OFFSET,
8eb07b18	355	};
0d923962	356
82242352 CL	357	#ifdef CONFIG_PPC64
82242352 CL	358	if (!radix_enabled())
0d923962	359	st.start_address = KERN_VIRT_START;
82242352	360	#endif
0d923962	361
8eb07b18 RG	362	/* Traverse kernel page tables */
	363	walk_pagetables(&st);
	364	note_page(&st, 0, 0, 0);
	365	return 0;
	366	}
	367
	368
	369	static int ptdump_open(struct inode inode, struct file file)
	370	{
	371	return single_open(file, ptdump_show, NULL);
	372	}
	373
	374	static const struct file_operations ptdump_fops = {
	375	.open = ptdump_open,
	376	.read = seq_read,
	377	.llseek = seq_lseek,
	378	.release = single_release,
	379	};
	380
	381	static void build_pgtable_complete_mask(void)
	382	{
	383	unsigned int i, j;
	384
	385	for (i = 0; i < ARRAY_SIZE(pg_level); i++)
	386	if (pg_level[i].flag)
	387	for (j = 0; j < pg_level[i].num; j++)
	388	pg_level[i].mask \|= pg_level[i].flag[j].mask;
	389	}
	390
453d87f6 RC	391	#ifdef CONFIG_PPC_DEBUG_WX
	392	void ptdump_check_wx(void)
	393	{
	394	struct pg_state st = {
	395	.seq = NULL,
	396	.marker = address_markers,
	397	.check_wx = true,
82242352	398	.start_address = PAGE_OFFSET,
453d87f6 RC	399	};
453d87f6 RC	400
82242352 CL	401	#ifdef CONFIG_PPC64
82242352 CL	402	if (!radix_enabled())
453d87f6	403	st.start_address = KERN_VIRT_START;
82242352	404	#endif
453d87f6 RC	405
	406	walk_pagetables(&st);
	407
	408	if (st.wx_pages)
	409	pr_warn("Checked W+X mappings: FAILED, %lu W+X pages found\n",
	410	st.wx_pages);
	411	else
	412	pr_info("Checked W+X mappings: passed, no W+X pages found\n");
	413	}
	414	#endif
	415
8eb07b18 RG	416	static int ptdump_init(void)
	417	{
	418	struct dentry *debugfs_file;
	419
	420	populate_markers();
	421	build_pgtable_complete_mask();
2505820f	422	debugfs_file = debugfs_create_file("kernel_page_tables", 0400, NULL,
8eb07b18 RG	423	NULL, &ptdump_fops);
	424	return debugfs_file ? 0 : -ENOMEM;
	425	}
	426	device_initcall(ptdump_init);