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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> | |
764011ca | 26 | #include <asm/memory.h> |
c9465b4e | 27 | #include <asm/pgtable.h> |
764011ca | 28 | #include <asm/pgtable-hwdef.h> |
c9465b4e | 29 | |
c9465b4e LA |
30 | struct addr_marker { |
31 | unsigned long start_address; | |
32 | const char *name; | |
33 | }; | |
34 | ||
35 | enum address_markers_idx { | |
f9040773 AB |
36 | MODULES_START_NR = 0, |
37 | MODULES_END_NR, | |
38 | VMALLOC_START_NR, | |
c9465b4e LA |
39 | VMALLOC_END_NR, |
40 | #ifdef CONFIG_SPARSEMEM_VMEMMAP | |
41 | VMEMMAP_START_NR, | |
42 | VMEMMAP_END_NR, | |
43 | #endif | |
c9465b4e LA |
44 | FIXADDR_START_NR, |
45 | FIXADDR_END_NR, | |
aa03c428 MR |
46 | PCI_START_NR, |
47 | PCI_END_NR, | |
c9465b4e LA |
48 | KERNEL_SPACE_NR, |
49 | }; | |
50 | ||
51 | static struct addr_marker address_markers[] = { | |
f9040773 AB |
52 | { MODULES_VADDR, "Modules start" }, |
53 | { MODULES_END, "Modules end" }, | |
c9465b4e LA |
54 | { VMALLOC_START, "vmalloc() Area" }, |
55 | { VMALLOC_END, "vmalloc() End" }, | |
56 | #ifdef CONFIG_SPARSEMEM_VMEMMAP | |
57 | { 0, "vmemmap start" }, | |
58 | { 0, "vmemmap end" }, | |
59 | #endif | |
c9465b4e LA |
60 | { FIXADDR_START, "Fixmap start" }, |
61 | { FIXADDR_TOP, "Fixmap end" }, | |
aa03c428 MR |
62 | { PCI_IO_START, "PCI I/O start" }, |
63 | { PCI_IO_END, "PCI I/O end" }, | |
f9040773 | 64 | { PAGE_OFFSET, "Linear Mapping" }, |
c9465b4e LA |
65 | { -1, NULL }, |
66 | }; | |
67 | ||
202e41a1 JL |
68 | /* |
69 | * The page dumper groups page table entries of the same type into a single | |
70 | * description. It uses pg_state to track the range information while | |
71 | * iterating over the pte entries. When the continuity is broken it then | |
72 | * dumps out a description of the range. | |
73 | */ | |
c9465b4e LA |
74 | struct pg_state { |
75 | struct seq_file *seq; | |
76 | const struct addr_marker *marker; | |
77 | unsigned long start_address; | |
78 | unsigned level; | |
79 | u64 current_prot; | |
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; | |
164 | size_t num; | |
165 | u64 mask; | |
166 | }; | |
167 | ||
168 | static struct pg_level pg_level[] = { | |
169 | { | |
170 | }, { /* pgd */ | |
171 | .bits = pte_bits, | |
172 | .num = ARRAY_SIZE(pte_bits), | |
173 | }, { /* pud */ | |
174 | .bits = pte_bits, | |
175 | .num = ARRAY_SIZE(pte_bits), | |
176 | }, { /* pmd */ | |
177 | .bits = pte_bits, | |
178 | .num = ARRAY_SIZE(pte_bits), | |
179 | }, { /* pte */ | |
180 | .bits = pte_bits, | |
181 | .num = ARRAY_SIZE(pte_bits), | |
182 | }, | |
183 | }; | |
184 | ||
185 | static void dump_prot(struct pg_state *st, const struct prot_bits *bits, | |
186 | size_t num) | |
187 | { | |
188 | unsigned i; | |
189 | ||
190 | for (i = 0; i < num; i++, bits++) { | |
191 | const char *s; | |
192 | ||
193 | if ((st->current_prot & bits->mask) == bits->val) | |
194 | s = bits->set; | |
195 | else | |
196 | s = bits->clear; | |
197 | ||
198 | if (s) | |
199 | seq_printf(st->seq, " %s", s); | |
200 | } | |
201 | } | |
202 | ||
203 | static void note_page(struct pg_state *st, unsigned long addr, unsigned level, | |
204 | u64 val) | |
205 | { | |
206 | static const char units[] = "KMGTPE"; | |
207 | u64 prot = val & pg_level[level].mask; | |
208 | ||
c9465b4e LA |
209 | if (!st->level) { |
210 | st->level = level; | |
211 | st->current_prot = prot; | |
212 | st->start_address = addr; | |
213 | seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); | |
214 | } else if (prot != st->current_prot || level != st->level || | |
215 | addr >= st->marker[1].start_address) { | |
216 | const char *unit = units; | |
217 | unsigned long delta; | |
218 | ||
219 | if (st->current_prot) { | |
202e41a1 | 220 | seq_printf(st->seq, "0x%016lx-0x%016lx ", |
c9465b4e LA |
221 | st->start_address, addr); |
222 | ||
223 | delta = (addr - st->start_address) >> 10; | |
224 | while (!(delta & 1023) && unit[1]) { | |
225 | delta >>= 10; | |
226 | unit++; | |
227 | } | |
228 | seq_printf(st->seq, "%9lu%c", delta, *unit); | |
229 | if (pg_level[st->level].bits) | |
230 | dump_prot(st, pg_level[st->level].bits, | |
231 | pg_level[st->level].num); | |
232 | seq_puts(st->seq, "\n"); | |
233 | } | |
234 | ||
235 | if (addr >= st->marker[1].start_address) { | |
236 | st->marker++; | |
237 | seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); | |
238 | } | |
239 | ||
240 | st->start_address = addr; | |
241 | st->current_prot = prot; | |
242 | st->level = level; | |
243 | } | |
244 | ||
245 | if (addr >= st->marker[1].start_address) { | |
246 | st->marker++; | |
247 | seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); | |
248 | } | |
249 | ||
250 | } | |
251 | ||
252 | static void walk_pte(struct pg_state *st, pmd_t *pmd, unsigned long start) | |
253 | { | |
254 | pte_t *pte = pte_offset_kernel(pmd, 0); | |
255 | unsigned long addr; | |
256 | unsigned i; | |
257 | ||
258 | for (i = 0; i < PTRS_PER_PTE; i++, pte++) { | |
259 | addr = start + i * PAGE_SIZE; | |
260 | note_page(st, addr, 4, pte_val(*pte)); | |
261 | } | |
262 | } | |
263 | ||
264 | static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start) | |
265 | { | |
266 | pmd_t *pmd = pmd_offset(pud, 0); | |
267 | unsigned long addr; | |
268 | unsigned i; | |
269 | ||
270 | for (i = 0; i < PTRS_PER_PMD; i++, pmd++) { | |
271 | addr = start + i * PMD_SIZE; | |
a1c76574 | 272 | if (pmd_none(*pmd) || pmd_sect(*pmd)) { |
c9465b4e | 273 | note_page(st, addr, 3, pmd_val(*pmd)); |
a1c76574 MR |
274 | } else { |
275 | BUG_ON(pmd_bad(*pmd)); | |
c9465b4e | 276 | walk_pte(st, pmd, addr); |
a1c76574 | 277 | } |
c9465b4e LA |
278 | } |
279 | } | |
280 | ||
281 | static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start) | |
282 | { | |
283 | pud_t *pud = pud_offset(pgd, 0); | |
284 | unsigned long addr; | |
285 | unsigned i; | |
286 | ||
287 | for (i = 0; i < PTRS_PER_PUD; i++, pud++) { | |
288 | addr = start + i * PUD_SIZE; | |
a1c76574 | 289 | if (pud_none(*pud) || pud_sect(*pud)) { |
c9465b4e | 290 | note_page(st, addr, 2, pud_val(*pud)); |
a1c76574 MR |
291 | } else { |
292 | BUG_ON(pud_bad(*pud)); | |
c9465b4e | 293 | walk_pmd(st, pud, addr); |
a1c76574 | 294 | } |
c9465b4e LA |
295 | } |
296 | } | |
297 | ||
298 | static void walk_pgd(struct pg_state *st, struct mm_struct *mm, unsigned long start) | |
299 | { | |
35545f0c | 300 | pgd_t *pgd = pgd_offset(mm, 0UL); |
c9465b4e LA |
301 | unsigned i; |
302 | unsigned long addr; | |
303 | ||
304 | for (i = 0; i < PTRS_PER_PGD; i++, pgd++) { | |
305 | addr = start + i * PGDIR_SIZE; | |
a1c76574 | 306 | if (pgd_none(*pgd)) { |
c9465b4e | 307 | note_page(st, addr, 1, pgd_val(*pgd)); |
a1c76574 MR |
308 | } else { |
309 | BUG_ON(pgd_bad(*pgd)); | |
c9465b4e | 310 | walk_pud(st, pgd, addr); |
a1c76574 | 311 | } |
c9465b4e LA |
312 | } |
313 | } | |
314 | ||
315 | static int ptdump_show(struct seq_file *m, void *v) | |
316 | { | |
317 | struct pg_state st = { | |
318 | .seq = m, | |
319 | .marker = address_markers, | |
320 | }; | |
321 | ||
cc30e6b9 | 322 | walk_pgd(&st, &init_mm, VA_START); |
c9465b4e LA |
323 | |
324 | note_page(&st, 0, 0, 0); | |
325 | return 0; | |
326 | } | |
327 | ||
328 | static int ptdump_open(struct inode *inode, struct file *file) | |
329 | { | |
330 | return single_open(file, ptdump_show, NULL); | |
331 | } | |
332 | ||
333 | static const struct file_operations ptdump_fops = { | |
334 | .open = ptdump_open, | |
335 | .read = seq_read, | |
336 | .llseek = seq_lseek, | |
337 | .release = single_release, | |
338 | }; | |
339 | ||
340 | static int ptdump_init(void) | |
341 | { | |
342 | struct dentry *pe; | |
343 | unsigned i, j; | |
344 | ||
345 | for (i = 0; i < ARRAY_SIZE(pg_level); i++) | |
346 | if (pg_level[i].bits) | |
347 | for (j = 0; j < pg_level[i].num; j++) | |
348 | pg_level[i].mask |= pg_level[i].bits[j].mask; | |
349 | ||
326a7803 | 350 | #ifdef CONFIG_SPARSEMEM_VMEMMAP |
c9465b4e LA |
351 | address_markers[VMEMMAP_START_NR].start_address = |
352 | (unsigned long)virt_to_page(PAGE_OFFSET); | |
353 | address_markers[VMEMMAP_END_NR].start_address = | |
354 | (unsigned long)virt_to_page(high_memory); | |
326a7803 | 355 | #endif |
c9465b4e LA |
356 | |
357 | pe = debugfs_create_file("kernel_page_tables", 0400, NULL, NULL, | |
358 | &ptdump_fops); | |
359 | return pe ? 0 : -ENOMEM; | |
360 | } | |
361 | device_initcall(ptdump_init); |