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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 LA |
29 | |
30 | #define LOWEST_ADDR (UL(0xffffffffffffffff) << VA_BITS) | |
31 | ||
32 | struct addr_marker { | |
33 | unsigned long start_address; | |
34 | const char *name; | |
35 | }; | |
36 | ||
37 | enum address_markers_idx { | |
38 | VMALLOC_START_NR = 0, | |
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 | MODULES_START_NR, |
49 | MODUELS_END_NR, | |
50 | KERNEL_SPACE_NR, | |
51 | }; | |
52 | ||
53 | static struct addr_marker address_markers[] = { | |
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" }, | |
c9465b4e LA |
64 | { MODULES_VADDR, "Modules start" }, |
65 | { MODULES_END, "Modules end" }, | |
66 | { PAGE_OFFSET, "Kernel Mapping" }, | |
67 | { -1, NULL }, | |
68 | }; | |
69 | ||
202e41a1 JL |
70 | /* |
71 | * The page dumper groups page table entries of the same type into a single | |
72 | * description. It uses pg_state to track the range information while | |
73 | * iterating over the pte entries. When the continuity is broken it then | |
74 | * dumps out a description of the range. | |
75 | */ | |
c9465b4e LA |
76 | struct pg_state { |
77 | struct seq_file *seq; | |
78 | const struct addr_marker *marker; | |
79 | unsigned long start_address; | |
80 | unsigned level; | |
81 | u64 current_prot; | |
82 | }; | |
83 | ||
84 | struct prot_bits { | |
85 | u64 mask; | |
86 | u64 val; | |
87 | const char *set; | |
88 | const char *clear; | |
89 | }; | |
90 | ||
91 | static const struct prot_bits pte_bits[] = { | |
92 | { | |
93 | .mask = PTE_USER, | |
94 | .val = PTE_USER, | |
95 | .set = "USR", | |
96 | .clear = " ", | |
97 | }, { | |
98 | .mask = PTE_RDONLY, | |
99 | .val = PTE_RDONLY, | |
100 | .set = "ro", | |
101 | .clear = "RW", | |
102 | }, { | |
103 | .mask = PTE_PXN, | |
104 | .val = PTE_PXN, | |
105 | .set = "NX", | |
106 | .clear = "x ", | |
107 | }, { | |
108 | .mask = PTE_SHARED, | |
109 | .val = PTE_SHARED, | |
110 | .set = "SHD", | |
111 | .clear = " ", | |
112 | }, { | |
113 | .mask = PTE_AF, | |
114 | .val = PTE_AF, | |
115 | .set = "AF", | |
116 | .clear = " ", | |
117 | }, { | |
118 | .mask = PTE_NG, | |
119 | .val = PTE_NG, | |
120 | .set = "NG", | |
121 | .clear = " ", | |
202e41a1 JL |
122 | }, { |
123 | .mask = PTE_CONT, | |
124 | .val = PTE_CONT, | |
125 | .set = "CON", | |
126 | .clear = " ", | |
127 | }, { | |
128 | .mask = PTE_TABLE_BIT, | |
129 | .val = PTE_TABLE_BIT, | |
130 | .set = " ", | |
131 | .clear = "BLK", | |
c9465b4e LA |
132 | }, { |
133 | .mask = PTE_UXN, | |
134 | .val = PTE_UXN, | |
135 | .set = "UXN", | |
136 | }, { | |
137 | .mask = PTE_ATTRINDX_MASK, | |
138 | .val = PTE_ATTRINDX(MT_DEVICE_nGnRnE), | |
139 | .set = "DEVICE/nGnRnE", | |
140 | }, { | |
141 | .mask = PTE_ATTRINDX_MASK, | |
142 | .val = PTE_ATTRINDX(MT_DEVICE_nGnRE), | |
143 | .set = "DEVICE/nGnRE", | |
144 | }, { | |
145 | .mask = PTE_ATTRINDX_MASK, | |
146 | .val = PTE_ATTRINDX(MT_DEVICE_GRE), | |
147 | .set = "DEVICE/GRE", | |
148 | }, { | |
149 | .mask = PTE_ATTRINDX_MASK, | |
150 | .val = PTE_ATTRINDX(MT_NORMAL_NC), | |
151 | .set = "MEM/NORMAL-NC", | |
152 | }, { | |
153 | .mask = PTE_ATTRINDX_MASK, | |
154 | .val = PTE_ATTRINDX(MT_NORMAL), | |
155 | .set = "MEM/NORMAL", | |
156 | } | |
157 | }; | |
158 | ||
159 | struct pg_level { | |
160 | const struct prot_bits *bits; | |
161 | size_t num; | |
162 | u64 mask; | |
163 | }; | |
164 | ||
165 | static struct pg_level pg_level[] = { | |
166 | { | |
167 | }, { /* pgd */ | |
168 | .bits = pte_bits, | |
169 | .num = ARRAY_SIZE(pte_bits), | |
170 | }, { /* pud */ | |
171 | .bits = pte_bits, | |
172 | .num = ARRAY_SIZE(pte_bits), | |
173 | }, { /* pmd */ | |
174 | .bits = pte_bits, | |
175 | .num = ARRAY_SIZE(pte_bits), | |
176 | }, { /* pte */ | |
177 | .bits = pte_bits, | |
178 | .num = ARRAY_SIZE(pte_bits), | |
179 | }, | |
180 | }; | |
181 | ||
182 | static void dump_prot(struct pg_state *st, const struct prot_bits *bits, | |
183 | size_t num) | |
184 | { | |
185 | unsigned i; | |
186 | ||
187 | for (i = 0; i < num; i++, bits++) { | |
188 | const char *s; | |
189 | ||
190 | if ((st->current_prot & bits->mask) == bits->val) | |
191 | s = bits->set; | |
192 | else | |
193 | s = bits->clear; | |
194 | ||
195 | if (s) | |
196 | seq_printf(st->seq, " %s", s); | |
197 | } | |
198 | } | |
199 | ||
200 | static void note_page(struct pg_state *st, unsigned long addr, unsigned level, | |
201 | u64 val) | |
202 | { | |
203 | static const char units[] = "KMGTPE"; | |
204 | u64 prot = val & pg_level[level].mask; | |
205 | ||
c9465b4e LA |
206 | if (!st->level) { |
207 | st->level = level; | |
208 | st->current_prot = prot; | |
209 | st->start_address = addr; | |
210 | seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); | |
211 | } else if (prot != st->current_prot || level != st->level || | |
212 | addr >= st->marker[1].start_address) { | |
213 | const char *unit = units; | |
214 | unsigned long delta; | |
215 | ||
216 | if (st->current_prot) { | |
202e41a1 | 217 | seq_printf(st->seq, "0x%016lx-0x%016lx ", |
c9465b4e LA |
218 | st->start_address, addr); |
219 | ||
220 | delta = (addr - st->start_address) >> 10; | |
221 | while (!(delta & 1023) && unit[1]) { | |
222 | delta >>= 10; | |
223 | unit++; | |
224 | } | |
225 | seq_printf(st->seq, "%9lu%c", delta, *unit); | |
226 | if (pg_level[st->level].bits) | |
227 | dump_prot(st, pg_level[st->level].bits, | |
228 | pg_level[st->level].num); | |
229 | seq_puts(st->seq, "\n"); | |
230 | } | |
231 | ||
232 | if (addr >= st->marker[1].start_address) { | |
233 | st->marker++; | |
234 | seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); | |
235 | } | |
236 | ||
237 | st->start_address = addr; | |
238 | st->current_prot = prot; | |
239 | st->level = level; | |
240 | } | |
241 | ||
242 | if (addr >= st->marker[1].start_address) { | |
243 | st->marker++; | |
244 | seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); | |
245 | } | |
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 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 | static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start) | |
262 | { | |
263 | pmd_t *pmd = pmd_offset(pud, 0); | |
264 | unsigned long addr; | |
265 | unsigned i; | |
266 | ||
267 | for (i = 0; i < PTRS_PER_PMD; i++, pmd++) { | |
268 | addr = start + i * PMD_SIZE; | |
a1c76574 | 269 | if (pmd_none(*pmd) || pmd_sect(*pmd)) { |
c9465b4e | 270 | note_page(st, addr, 3, pmd_val(*pmd)); |
a1c76574 MR |
271 | } else { |
272 | BUG_ON(pmd_bad(*pmd)); | |
c9465b4e | 273 | walk_pte(st, pmd, addr); |
a1c76574 | 274 | } |
c9465b4e LA |
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 i; | |
283 | ||
284 | for (i = 0; i < PTRS_PER_PUD; i++, pud++) { | |
285 | addr = start + i * PUD_SIZE; | |
a1c76574 | 286 | if (pud_none(*pud) || pud_sect(*pud)) { |
c9465b4e | 287 | note_page(st, addr, 2, pud_val(*pud)); |
a1c76574 MR |
288 | } else { |
289 | BUG_ON(pud_bad(*pud)); | |
c9465b4e | 290 | walk_pmd(st, pud, addr); |
a1c76574 | 291 | } |
c9465b4e LA |
292 | } |
293 | } | |
294 | ||
295 | static void walk_pgd(struct pg_state *st, struct mm_struct *mm, unsigned long start) | |
296 | { | |
35545f0c | 297 | pgd_t *pgd = pgd_offset(mm, 0UL); |
c9465b4e LA |
298 | unsigned i; |
299 | unsigned long addr; | |
300 | ||
301 | for (i = 0; i < PTRS_PER_PGD; i++, pgd++) { | |
302 | addr = start + i * PGDIR_SIZE; | |
a1c76574 | 303 | if (pgd_none(*pgd)) { |
c9465b4e | 304 | note_page(st, addr, 1, pgd_val(*pgd)); |
a1c76574 MR |
305 | } else { |
306 | BUG_ON(pgd_bad(*pgd)); | |
c9465b4e | 307 | walk_pud(st, pgd, addr); |
a1c76574 | 308 | } |
c9465b4e LA |
309 | } |
310 | } | |
311 | ||
312 | static int ptdump_show(struct seq_file *m, void *v) | |
313 | { | |
314 | struct pg_state st = { | |
315 | .seq = m, | |
316 | .marker = address_markers, | |
317 | }; | |
318 | ||
319 | walk_pgd(&st, &init_mm, LOWEST_ADDR); | |
320 | ||
321 | note_page(&st, 0, 0, 0); | |
322 | return 0; | |
323 | } | |
324 | ||
325 | static int ptdump_open(struct inode *inode, struct file *file) | |
326 | { | |
327 | return single_open(file, ptdump_show, NULL); | |
328 | } | |
329 | ||
330 | static const struct file_operations ptdump_fops = { | |
331 | .open = ptdump_open, | |
332 | .read = seq_read, | |
333 | .llseek = seq_lseek, | |
334 | .release = single_release, | |
335 | }; | |
336 | ||
337 | static int ptdump_init(void) | |
338 | { | |
339 | struct dentry *pe; | |
340 | unsigned i, j; | |
341 | ||
342 | for (i = 0; i < ARRAY_SIZE(pg_level); i++) | |
343 | if (pg_level[i].bits) | |
344 | for (j = 0; j < pg_level[i].num; j++) | |
345 | pg_level[i].mask |= pg_level[i].bits[j].mask; | |
346 | ||
326a7803 | 347 | #ifdef CONFIG_SPARSEMEM_VMEMMAP |
c9465b4e LA |
348 | address_markers[VMEMMAP_START_NR].start_address = |
349 | (unsigned long)virt_to_page(PAGE_OFFSET); | |
350 | address_markers[VMEMMAP_END_NR].start_address = | |
351 | (unsigned long)virt_to_page(high_memory); | |
326a7803 | 352 | #endif |
c9465b4e LA |
353 | |
354 | pe = debugfs_create_file("kernel_page_tables", 0400, NULL, NULL, | |
355 | &ptdump_fops); | |
356 | return pe ? 0 : -ENOMEM; | |
357 | } | |
358 | device_initcall(ptdump_init); |