[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 <linux/const.h>
#include <asm/page.h>
#include <asm/hugetlb.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 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" },
#ifdef MODULES_VADDR
	{ 0,	"modules start" },
	{ 0,	"modules end" },
#endif
	{ 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);		\
})

void pt_dump_size(struct seq_file *m, unsigned long size)
{
	static const char units[] = "KMGTPE";
	const char *unit = units;

	/* Work out what appropriate unit to use */
	while (!(size & 1023) && unit[1]) {
		size >>= 10;
		unit++;
	}
	pt_dump_seq_printf(m, "%9lu%c ", size, *unit);
}

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)
{
#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);
	pt_dump_seq_printf(st->seq, " " REG " ", st->start_pa);
	pt_dump_size(st->seq, (addr - st->start_address) >> 10);
}

static void note_prot_wx(struct pg_state *st, unsigned long addr)
{
	pte_t pte = __pte(st->current_flags);

	if (!IS_ENABLED(CONFIG_PPC_DEBUG_WX) || !st->check_wx)
		return;

	if (!pte_write(pte) || !pte_exec(pte))
		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_update_state(struct pg_state *st, unsigned long addr,
				   unsigned int level, u64 val, unsigned long page_size)
{
	u64 flag = val & pg_level[level].mask;
	u64 pa = val & PTE_RPN_MASK;

	st->level = level;
	st->current_flags = flag;
	st->start_address = addr;
	st->start_pa = pa;

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

static void note_page(struct pg_state *st, unsigned long addr,
	       unsigned int level, u64 val, unsigned long page_size)
{
	u64 flag = val & pg_level[level].mask;

	/* At first no level is set */
	if (!st->level) {
		pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
		note_page_update_state(st, addr, level, val, page_size);
	/*
	 * 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.
	 */
	} else if (flag != st->current_flags || level != st->level ||
		   addr >= st->marker[1].start_address) {

		/* 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
		 */
		note_page_update_state(st, addr, level, val, page_size);
	}
}

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), PAGE_SIZE);

	}
}

static void walk_hugepd(struct pg_state *st, hugepd_t *phpd, unsigned long start,
			int pdshift, int level)
{
#ifdef CONFIG_ARCH_HAS_HUGEPD
	unsigned int i;
	int shift = hugepd_shift(*phpd);
	int ptrs_per_hpd = pdshift - shift > 0 ? 1 << (pdshift - shift) : 1;

	if (start & ((1 << shift) - 1))
		return;

	for (i = 0; i < ptrs_per_hpd; i++) {
		unsigned long addr = start + (i << shift);
		pte_t *pte = hugepte_offset(*phpd, addr, pdshift);

		note_page(st, addr, level + 1, pte_val(*pte), 1 << shift);
	}
#endif
}

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), PMD_SIZE);
	}
}

static void walk_pud(struct pg_state *st, p4d_t *p4d, unsigned long start)
{
	pud_t *pud = pud_offset(p4d, 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), PUD_SIZE);
	}
}

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) {
		p4d_t *p4d = p4d_offset(pgd, 0);

		if (p4d_none(*p4d) || p4d_is_leaf(*p4d))
			note_page(st, addr, 1, p4d_val(*p4d), PGDIR_SIZE);
		else if (is_hugepd(__hugepd(p4d_val(*p4d))))
			walk_hugepd(st, (hugepd_t *)p4d, addr, PGDIR_SHIFT, 1);
		else
			/* p4d exists */
			walk_pud(st, p4d, addr);
	}
}

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

#ifdef CONFIG_PPC64
	address_markers[i++].start_address = PAGE_OFFSET;
#else
	address_markers[i++].start_address = TASK_SIZE;
#endif
#ifdef MODULES_VADDR
	address_markers[i++].start_address = MODULES_VADDR;
	address_markers[i++].start_address = MODULES_END;
#endif
	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 = IS_ENABLED(CONFIG_PPC64) ? PAGE_OFFSET : TASK_SIZE,
	};

#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, 0);
	return 0;
}

DEFINE_SHOW_ATTRIBUTE(ptdump);

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 = IS_ENABLED(CONFIG_PPC64) ? PAGE_OFFSET : TASK_SIZE,
	};

#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)
{
	populate_markers();
	build_pgtable_complete_mask();
	debugfs_create_file("kernel_page_tables", 0400, NULL, NULL,
			    &ptdump_fops);
	return 0;
}
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>
8eb07b18 RG	22	#include <linux/const.h>
8eb07b18 RG	23	#include <asm/page.h>
6b789a26	24	#include <asm/hugetlb.h>
8eb07b18	25
1e1c8b2c CL	26	#include <mm/mmu_decl.h>
1e1c8b2c CL	27
e66c3209	28	#include "ptdump.h"
97026b5a	29
8eb07b18 RG	30	/*
	31	* To visualise what is happening,
	32	*
	33	* - PTRS_PER_P = how many entries there are in the corresponding P
	34	* - P**_SHIFT = how many bits of the address we use to index into the
	35	* corresponding P**
	36	* - P**_SIZE is how much memory we can access through the table - not the
	37	* size of the table itself.
	38	* P**={PGD, PUD, PMD, PTE}
	39	*
	40	*
	41	* Each entry of the PGD points to a PUD. Each entry of a PUD points to a
	42	* PMD. Each entry of a PMD points to a PTE. And every PTE entry points to
	43	* a page.
	44	*
	45	* In the case where there are only 3 levels, the PUD is folded into the
	46	* PGD: every PUD has only one entry which points to the PMD.
	47	*
	48	* The page dumper groups page table entries of the same type into a single
	49	* description. It uses pg_state to track the range information while
	50	* iterating over the PTE entries. When the continuity is broken it then
	51	* dumps out a description of the range - ie PTEs that are virtually contiguous
	52	* with the same PTE flags are chunked together. This is to make it clear how
	53	* different areas of the kernel virtual memory are used.
	54	*
	55	*/
	56	struct pg_state {
	57	struct seq_file *seq;
	58	const struct addr_marker *marker;
	59	unsigned long start_address;
aaa22952	60	unsigned long start_pa;
8eb07b18 RG	61	unsigned int level;
8eb07b18 RG	62	u64 current_flags;
453d87f6 RC	63	bool check_wx;
453d87f6 RC	64	unsigned long wx_pages;
8eb07b18 RG	65	};
	66
	67	struct addr_marker {
	68	unsigned long start_address;
	69	const char *name;
	70	};
	71
	72	static struct addr_marker address_markers[] = {
	73	{ 0, "Start of kernel VM" },
6ca05532 CL	74	#ifdef MODULES_VADDR
	75	{ 0, "modules start" },
	76	{ 0, "modules end" },
	77	#endif
8eb07b18 RG	78	{ 0, "vmalloc() Area" },
8eb07b18 RG	79	{ 0, "vmalloc() End" },
6c01bbd2	80	#ifdef CONFIG_PPC64
8eb07b18 RG	81	{ 0, "isa I/O start" },
	82	{ 0, "isa I/O end" },
	83	{ 0, "phb I/O start" },
	84	{ 0, "phb I/O end" },
	85	{ 0, "I/O remap start" },
	86	{ 0, "I/O remap end" },
	87	{ 0, "vmemmap start" },
6c01bbd2 CL	88	#else
	89	{ 0, "Early I/O remap start" },
	90	{ 0, "Early I/O remap end" },
6c01bbd2 CL	91	#ifdef CONFIG_HIGHMEM
	92	{ 0, "Highmem PTEs start" },
	93	{ 0, "Highmem PTEs end" },
	94	#endif
	95	{ 0, "Fixmap start" },
	96	{ 0, "Fixmap end" },
b4abe38f CL	97	#endif
	98	#ifdef CONFIG_KASAN
	99	{ 0, "kasan shadow mem start" },
	100	{ 0, "kasan shadow mem end" },
6c01bbd2	101	#endif
8eb07b18 RG	102	{ -1, NULL },
	103	};
	104
5f18cbdb RC	105	#define pt_dump_seq_printf(m, fmt, args...) \
	106	({ \
	107	if (m) \
	108	seq_printf(m, fmt, ##args); \
	109	})
	110
	111	#define pt_dump_seq_putc(m, c) \
	112	({ \
	113	if (m) \
	114	seq_putc(m, c); \
	115	})
	116
6b30830e CL	117	void pt_dump_size(struct seq_file *m, unsigned long size)
	118	{
	119	static const char units[] = "KMGTPE";
	120	const char *unit = units;
	121
	122	/* Work out what appropriate unit to use */
	123	while (!(size & 1023) && unit[1]) {
	124	size >>= 10;
	125	unit++;
	126	}
	127	pt_dump_seq_printf(m, "%9lu%c ", size, *unit);
	128	}
	129
8eb07b18 RG	130	static void dump_flag_info(struct pg_state *st, const struct flag_info
	131	*flag, u64 pte, int num)
	132	{
	133	unsigned int i;
	134
	135	for (i = 0; i < num; i++, flag++) {
	136	const char *s = NULL;
	137	u64 val;
	138
	139	/* flag not defined so don't check it */
	140	if (flag->mask == 0)
	141	continue;
	142	/* Some 'flags' are actually values */
	143	if (flag->is_val) {
	144	val = pte & flag->val;
	145	if (flag->shift)
	146	val = val >> flag->shift;
5f18cbdb	147	pt_dump_seq_printf(st->seq, " %s:%llx", flag->set, val);
8eb07b18 RG	148	} else {
	149	if ((pte & flag->mask) == flag->val)
	150	s = flag->set;
	151	else
	152	s = flag->clear;
	153	if (s)
5f18cbdb	154	pt_dump_seq_printf(st->seq, " %s", s);
8eb07b18 RG	155	}
	156	st->current_flags &= ~flag->mask;
	157	}
	158	if (st->current_flags != 0)
5f18cbdb	159	pt_dump_seq_printf(st->seq, " unknown flags:%llx", st->current_flags);
8eb07b18 RG	160	}
	161
	162	static void dump_addr(struct pg_state *st, unsigned long addr)
	163	{
78a18dbf	164	#ifdef CONFIG_PPC64
cabe8138	165	#define REG "0x%016lx"
78a18dbf	166	#else
cabe8138	167	#define REG "0x%08lx"
78a18dbf	168	#endif
aaa22952	169
5f18cbdb	170	pt_dump_seq_printf(st->seq, REG "-" REG " ", st->start_address, addr - 1);
6ca6512c CL	171	pt_dump_seq_printf(st->seq, " " REG " ", st->start_pa);
6ca6512c CL	172	pt_dump_size(st->seq, (addr - st->start_address) >> 10);
8eb07b18 RG	173	}
8eb07b18 RG	174
453d87f6 RC	175	static void note_prot_wx(struct pg_state *st, unsigned long addr)
453d87f6 RC	176	{
d80ae83f CL	177	pte_t pte = __pte(st->current_flags);
d80ae83f CL	178
f3a2ac05	179	if (!IS_ENABLED(CONFIG_PPC_DEBUG_WX) \|\| !st->check_wx)
453d87f6 RC	180	return;
453d87f6 RC	181
d80ae83f	182	if (!pte_write(pte) \|\| !pte_exec(pte))
453d87f6 RC	183	return;
	184
	185	WARN_ONCE(1, "powerpc/mm: Found insecure W+X mapping at address %p/%pS\n",
	186	(void )st->start_address, (void )st->start_address);
	187
	188	st->wx_pages += (addr - st->start_address) / PAGE_SIZE;
	189	}
	190
e54e30bc CL	191	static void note_page_update_state(struct pg_state *st, unsigned long addr,
	192	unsigned int level, u64 val, unsigned long page_size)
	193	{
	194	u64 flag = val & pg_level[level].mask;
	195	u64 pa = val & PTE_RPN_MASK;
	196
	197	st->level = level;
	198	st->current_flags = flag;
	199	st->start_address = addr;
	200	st->start_pa = pa;
e54e30bc CL	201
	202	while (addr >= st->marker[1].start_address) {
	203	st->marker++;
	204	pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
	205	}
	206	}
	207
8eb07b18	208	static void note_page(struct pg_state *st, unsigned long addr,
b00ff6d8	209	unsigned int level, u64 val, unsigned long page_size)
8eb07b18 RG	210	{
8eb07b18 RG	211	u64 flag = val & pg_level[level].mask;
aaa22952	212
8eb07b18 RG	213	/* At first no level is set */
8eb07b18 RG	214	if (!st->level) {
5f18cbdb	215	pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
e54e30bc	216	note_page_update_state(st, addr, level, val, page_size);
8eb07b18 RG	217	/*
	218	* Dump the section of virtual memory when:
	219	* - the PTE flags from one entry to the next differs.
	220	* - we change levels in the tree.
	221	* - the address is in a different section of memory and is thus
	222	* used for a different purpose, regardless of the flags.
	223	*/
	224	} else if (flag != st->current_flags \|\| level != st->level \|\|
6ca6512c	225	addr >= st->marker[1].start_address) {
8eb07b18 RG	226
	227	/* Check the PTE flags */
	228	if (st->current_flags) {
453d87f6	229	note_prot_wx(st, addr);
8eb07b18 RG	230	dump_addr(st, addr);
	231
	232	/* Dump all the flags */
	233	if (pg_level[st->level].flag)
	234	dump_flag_info(st, pg_level[st->level].flag,
	235	st->current_flags,
	236	pg_level[st->level].num);
	237
5f18cbdb	238	pt_dump_seq_putc(st->seq, '\n');
8eb07b18 RG	239	}
	240
	241	/*
	242	* Address indicates we have passed the end of the
	243	* current section of virtual memory
	244	*/
e54e30bc	245	note_page_update_state(st, addr, level, val, page_size);
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;
b00ff6d8	257	note_page(st, addr, 4, pte_val(*pte), PAGE_SIZE);
8eb07b18 RG	258
	259	}
	260	}
	261
6b789a26 CL	262	static void walk_hugepd(struct pg_state st, hugepd_t phpd, unsigned long start,
	263	int pdshift, int level)
	264	{
	265	#ifdef CONFIG_ARCH_HAS_HUGEPD
	266	unsigned int i;
	267	int shift = hugepd_shift(*phpd);
	268	int ptrs_per_hpd = pdshift - shift > 0 ? 1 << (pdshift - shift) : 1;
	269
	270	if (start & ((1 << shift) - 1))
	271	return;
	272
	273	for (i = 0; i < ptrs_per_hpd; i++) {
	274	unsigned long addr = start + (i << shift);
	275	pte_t pte = hugepte_offset(phpd, addr, pdshift);
	276
	277	note_page(st, addr, level + 1, pte_val(*pte), 1 << shift);
	278	}
	279	#endif
	280	}
	281
8eb07b18 RG	282	static void walk_pmd(struct pg_state st, pud_t pud, unsigned long start)
	283	{
	284	pmd_t *pmd = pmd_offset(pud, 0);
	285	unsigned long addr;
	286	unsigned int i;
	287
	288	for (i = 0; i < PTRS_PER_PMD; i++, pmd++) {
	289	addr = start + i * PMD_SIZE;
d6eacedd	290	if (!pmd_none(pmd) && !pmd_is_leaf(pmd))
8eb07b18 RG	291	/* pmd exists */
	292	walk_pte(st, pmd, addr);
	293	else
b00ff6d8	294	note_page(st, addr, 3, pmd_val(*pmd), PMD_SIZE);
8eb07b18 RG	295	}
	296	}
	297
2fb47060	298	static void walk_pud(struct pg_state st, p4d_t p4d, unsigned long start)
8eb07b18	299	{
2fb47060	300	pud_t *pud = pud_offset(p4d, 0);
8eb07b18 RG	301	unsigned long addr;
	302	unsigned int i;
	303
	304	for (i = 0; i < PTRS_PER_PUD; i++, pud++) {
	305	addr = start + i * PUD_SIZE;
d6eacedd	306	if (!pud_none(pud) && !pud_is_leaf(pud))
8eb07b18 RG	307	/* pud exists */
	308	walk_pmd(st, pud, addr);
	309	else
b00ff6d8	310	note_page(st, addr, 2, pud_val(*pud), PUD_SIZE);
8eb07b18 RG	311	}
	312	}
	313
	314	static void walk_pagetables(struct pg_state *st)
	315	{
8eb07b18	316	unsigned int i;
e033829d CL	317	unsigned long addr = st->start_address & PGDIR_MASK;
e033829d CL	318	pgd_t *pgd = pgd_offset_k(addr);
0d923962	319
8eb07b18 RG	320	/*
	321	* Traverse the linux pagetable structure and dump pages that are in
	322	* the hash pagetable.
	323	*/
e033829d	324	for (i = pgd_index(addr); i < PTRS_PER_PGD; i++, pgd++, addr += PGDIR_SIZE) {
2fb47060 MR	325	p4d_t *p4d = p4d_offset(pgd, 0);
2fb47060 MR	326
7ae77150 LT	327	if (p4d_none(p4d) \|\| p4d_is_leaf(p4d))
	328	note_page(st, addr, 1, p4d_val(*p4d), PGDIR_SIZE);
	329	else if (is_hugepd(__hugepd(p4d_val(*p4d))))
	330	walk_hugepd(st, (hugepd_t *)p4d, addr, PGDIR_SHIFT, 1);
8eb07b18	331	else
7ae77150 LT	332	/* p4d exists */
7ae77150 LT	333	walk_pud(st, p4d, addr);
8eb07b18 RG	334	}
	335	}
	336
	337	static void populate_markers(void)
	338	{
6c01bbd2 CL	339	int i = 0;
6c01bbd2 CL	340
b6be1bb7	341	#ifdef CONFIG_PPC64
6c01bbd2	342	address_markers[i++].start_address = PAGE_OFFSET;
b6be1bb7 CL	343	#else
b6be1bb7 CL	344	address_markers[i++].start_address = TASK_SIZE;
6ca05532 CL	345	#endif
	346	#ifdef MODULES_VADDR
	347	address_markers[i++].start_address = MODULES_VADDR;
	348	address_markers[i++].start_address = MODULES_END;
b6be1bb7	349	#endif
6c01bbd2 CL	350	address_markers[i++].start_address = VMALLOC_START;
	351	address_markers[i++].start_address = VMALLOC_END;
	352	#ifdef CONFIG_PPC64
	353	address_markers[i++].start_address = ISA_IO_BASE;
	354	address_markers[i++].start_address = ISA_IO_END;
	355	address_markers[i++].start_address = PHB_IO_BASE;
	356	address_markers[i++].start_address = PHB_IO_END;
	357	address_markers[i++].start_address = IOREMAP_BASE;
	358	address_markers[i++].start_address = IOREMAP_END;
0034d395	359	/* What is the ifdef about? */
4e003747	360	#ifdef CONFIG_PPC_BOOK3S_64
0034d395	361	address_markers[i++].start_address = H_VMEMMAP_START;
8eb07b18	362	#else
6c01bbd2 CL	363	address_markers[i++].start_address = VMEMMAP_BASE;
	364	#endif
	365	#else /* !CONFIG_PPC64 */
	366	address_markers[i++].start_address = ioremap_bot;
	367	address_markers[i++].start_address = IOREMAP_TOP;
6c01bbd2 CL	368	#ifdef CONFIG_HIGHMEM
	369	address_markers[i++].start_address = PKMAP_BASE;
	370	address_markers[i++].start_address = PKMAP_ADDR(LAST_PKMAP);
8eb07b18	371	#endif
6c01bbd2 CL	372	address_markers[i++].start_address = FIXADDR_START;
6c01bbd2 CL	373	address_markers[i++].start_address = FIXADDR_TOP;
b4abe38f CL	374	#ifdef CONFIG_KASAN
	375	address_markers[i++].start_address = KASAN_SHADOW_START;
	376	address_markers[i++].start_address = KASAN_SHADOW_END;
	377	#endif
6c01bbd2	378	#endif /* CONFIG_PPC64 */
8eb07b18 RG	379	}
	380
	381	static int ptdump_show(struct seq_file m, void v)
	382	{
	383	struct pg_state st = {
	384	.seq = m,
8eb07b18	385	.marker = address_markers,
b6be1bb7	386	.start_address = IS_ENABLED(CONFIG_PPC64) ? PAGE_OFFSET : TASK_SIZE,
8eb07b18	387	};
0d923962	388
82242352 CL	389	#ifdef CONFIG_PPC64
82242352 CL	390	if (!radix_enabled())
0d923962	391	st.start_address = KERN_VIRT_START;
82242352	392	#endif
0d923962	393
8eb07b18 RG	394	/* Traverse kernel page tables */
8eb07b18 RG	395	walk_pagetables(&st);
b00ff6d8	396	note_page(&st, 0, 0, 0, 0);
8eb07b18 RG	397	return 0;
	398	}
	399
11f27a7f	400	DEFINE_SHOW_ATTRIBUTE(ptdump);
8eb07b18 RG	401
	402	static void build_pgtable_complete_mask(void)
	403	{
	404	unsigned int i, j;
	405
	406	for (i = 0; i < ARRAY_SIZE(pg_level); i++)
	407	if (pg_level[i].flag)
	408	for (j = 0; j < pg_level[i].num; j++)
	409	pg_level[i].mask \|= pg_level[i].flag[j].mask;
	410	}
	411
453d87f6 RC	412	#ifdef CONFIG_PPC_DEBUG_WX
	413	void ptdump_check_wx(void)
	414	{
	415	struct pg_state st = {
	416	.seq = NULL,
	417	.marker = address_markers,
	418	.check_wx = true,
b6be1bb7	419	.start_address = IS_ENABLED(CONFIG_PPC64) ? PAGE_OFFSET : TASK_SIZE,
453d87f6 RC	420	};
453d87f6 RC	421
82242352 CL	422	#ifdef CONFIG_PPC64
82242352 CL	423	if (!radix_enabled())
453d87f6	424	st.start_address = KERN_VIRT_START;
82242352	425	#endif
453d87f6 RC	426
	427	walk_pagetables(&st);
	428
	429	if (st.wx_pages)
	430	pr_warn("Checked W+X mappings: FAILED, %lu W+X pages found\n",
	431	st.wx_pages);
	432	else
	433	pr_info("Checked W+X mappings: passed, no W+X pages found\n");
	434	}
	435	#endif
	436
8eb07b18 RG	437	static int ptdump_init(void)
8eb07b18 RG	438	{
8eb07b18 RG	439	populate_markers();
8eb07b18 RG	440	build_pgtable_complete_mask();
f3c05201 GKH	441	debugfs_create_file("kernel_page_tables", 0400, NULL, NULL,
	442	&ptdump_fops);
	443	return 0;
8eb07b18 RG	444	}
8eb07b18 RG	445	device_initcall(ptdump_init);