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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 | ||
70 | struct pg_state { | |
71 | struct seq_file *seq; | |
72 | const struct addr_marker *marker; | |
73 | unsigned long start_address; | |
74 | unsigned level; | |
75 | u64 current_prot; | |
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 | { | |
87 | .mask = PTE_USER, | |
88 | .val = PTE_USER, | |
89 | .set = "USR", | |
90 | .clear = " ", | |
91 | }, { | |
92 | .mask = PTE_RDONLY, | |
93 | .val = PTE_RDONLY, | |
94 | .set = "ro", | |
95 | .clear = "RW", | |
96 | }, { | |
97 | .mask = PTE_PXN, | |
98 | .val = PTE_PXN, | |
99 | .set = "NX", | |
100 | .clear = "x ", | |
101 | }, { | |
102 | .mask = PTE_SHARED, | |
103 | .val = PTE_SHARED, | |
104 | .set = "SHD", | |
105 | .clear = " ", | |
106 | }, { | |
107 | .mask = PTE_AF, | |
108 | .val = PTE_AF, | |
109 | .set = "AF", | |
110 | .clear = " ", | |
111 | }, { | |
112 | .mask = PTE_NG, | |
113 | .val = PTE_NG, | |
114 | .set = "NG", | |
115 | .clear = " ", | |
116 | }, { | |
117 | .mask = PTE_UXN, | |
118 | .val = PTE_UXN, | |
119 | .set = "UXN", | |
120 | }, { | |
121 | .mask = PTE_ATTRINDX_MASK, | |
122 | .val = PTE_ATTRINDX(MT_DEVICE_nGnRnE), | |
123 | .set = "DEVICE/nGnRnE", | |
124 | }, { | |
125 | .mask = PTE_ATTRINDX_MASK, | |
126 | .val = PTE_ATTRINDX(MT_DEVICE_nGnRE), | |
127 | .set = "DEVICE/nGnRE", | |
128 | }, { | |
129 | .mask = PTE_ATTRINDX_MASK, | |
130 | .val = PTE_ATTRINDX(MT_DEVICE_GRE), | |
131 | .set = "DEVICE/GRE", | |
132 | }, { | |
133 | .mask = PTE_ATTRINDX_MASK, | |
134 | .val = PTE_ATTRINDX(MT_NORMAL_NC), | |
135 | .set = "MEM/NORMAL-NC", | |
136 | }, { | |
137 | .mask = PTE_ATTRINDX_MASK, | |
138 | .val = PTE_ATTRINDX(MT_NORMAL), | |
139 | .set = "MEM/NORMAL", | |
140 | } | |
141 | }; | |
142 | ||
143 | struct pg_level { | |
144 | const struct prot_bits *bits; | |
145 | size_t num; | |
146 | u64 mask; | |
147 | }; | |
148 | ||
149 | static struct pg_level pg_level[] = { | |
150 | { | |
151 | }, { /* pgd */ | |
152 | .bits = pte_bits, | |
153 | .num = ARRAY_SIZE(pte_bits), | |
154 | }, { /* pud */ | |
155 | .bits = pte_bits, | |
156 | .num = ARRAY_SIZE(pte_bits), | |
157 | }, { /* pmd */ | |
158 | .bits = pte_bits, | |
159 | .num = ARRAY_SIZE(pte_bits), | |
160 | }, { /* pte */ | |
161 | .bits = pte_bits, | |
162 | .num = ARRAY_SIZE(pte_bits), | |
163 | }, | |
164 | }; | |
165 | ||
166 | static void dump_prot(struct pg_state *st, const struct prot_bits *bits, | |
167 | size_t num) | |
168 | { | |
169 | unsigned i; | |
170 | ||
171 | for (i = 0; i < num; i++, bits++) { | |
172 | const char *s; | |
173 | ||
174 | if ((st->current_prot & bits->mask) == bits->val) | |
175 | s = bits->set; | |
176 | else | |
177 | s = bits->clear; | |
178 | ||
179 | if (s) | |
180 | seq_printf(st->seq, " %s", s); | |
181 | } | |
182 | } | |
183 | ||
184 | static void note_page(struct pg_state *st, unsigned long addr, unsigned level, | |
185 | u64 val) | |
186 | { | |
187 | static const char units[] = "KMGTPE"; | |
188 | u64 prot = val & pg_level[level].mask; | |
189 | ||
c9465b4e LA |
190 | if (!st->level) { |
191 | st->level = level; | |
192 | st->current_prot = prot; | |
193 | st->start_address = addr; | |
194 | seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); | |
195 | } else if (prot != st->current_prot || level != st->level || | |
196 | addr >= st->marker[1].start_address) { | |
197 | const char *unit = units; | |
198 | unsigned long delta; | |
199 | ||
200 | if (st->current_prot) { | |
201 | seq_printf(st->seq, "0x%16lx-0x%16lx ", | |
202 | st->start_address, addr); | |
203 | ||
204 | delta = (addr - st->start_address) >> 10; | |
205 | while (!(delta & 1023) && unit[1]) { | |
206 | delta >>= 10; | |
207 | unit++; | |
208 | } | |
209 | seq_printf(st->seq, "%9lu%c", delta, *unit); | |
210 | if (pg_level[st->level].bits) | |
211 | dump_prot(st, pg_level[st->level].bits, | |
212 | pg_level[st->level].num); | |
213 | seq_puts(st->seq, "\n"); | |
214 | } | |
215 | ||
216 | if (addr >= st->marker[1].start_address) { | |
217 | st->marker++; | |
218 | seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); | |
219 | } | |
220 | ||
221 | st->start_address = addr; | |
222 | st->current_prot = prot; | |
223 | st->level = level; | |
224 | } | |
225 | ||
226 | if (addr >= st->marker[1].start_address) { | |
227 | st->marker++; | |
228 | seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); | |
229 | } | |
230 | ||
231 | } | |
232 | ||
233 | static void walk_pte(struct pg_state *st, pmd_t *pmd, unsigned long start) | |
234 | { | |
235 | pte_t *pte = pte_offset_kernel(pmd, 0); | |
236 | unsigned long addr; | |
237 | unsigned i; | |
238 | ||
239 | for (i = 0; i < PTRS_PER_PTE; i++, pte++) { | |
240 | addr = start + i * PAGE_SIZE; | |
241 | note_page(st, addr, 4, pte_val(*pte)); | |
242 | } | |
243 | } | |
244 | ||
245 | static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start) | |
246 | { | |
247 | pmd_t *pmd = pmd_offset(pud, 0); | |
248 | unsigned long addr; | |
249 | unsigned i; | |
250 | ||
251 | for (i = 0; i < PTRS_PER_PMD; i++, pmd++) { | |
252 | addr = start + i * PMD_SIZE; | |
a1c76574 | 253 | if (pmd_none(*pmd) || pmd_sect(*pmd)) { |
c9465b4e | 254 | note_page(st, addr, 3, pmd_val(*pmd)); |
a1c76574 MR |
255 | } else { |
256 | BUG_ON(pmd_bad(*pmd)); | |
c9465b4e | 257 | walk_pte(st, pmd, addr); |
a1c76574 | 258 | } |
c9465b4e LA |
259 | } |
260 | } | |
261 | ||
262 | static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start) | |
263 | { | |
264 | pud_t *pud = pud_offset(pgd, 0); | |
265 | unsigned long addr; | |
266 | unsigned i; | |
267 | ||
268 | for (i = 0; i < PTRS_PER_PUD; i++, pud++) { | |
269 | addr = start + i * PUD_SIZE; | |
a1c76574 | 270 | if (pud_none(*pud) || pud_sect(*pud)) { |
c9465b4e | 271 | note_page(st, addr, 2, pud_val(*pud)); |
a1c76574 MR |
272 | } else { |
273 | BUG_ON(pud_bad(*pud)); | |
c9465b4e | 274 | walk_pmd(st, pud, addr); |
a1c76574 | 275 | } |
c9465b4e LA |
276 | } |
277 | } | |
278 | ||
279 | static void walk_pgd(struct pg_state *st, struct mm_struct *mm, unsigned long start) | |
280 | { | |
35545f0c | 281 | pgd_t *pgd = pgd_offset(mm, 0UL); |
c9465b4e LA |
282 | unsigned i; |
283 | unsigned long addr; | |
284 | ||
285 | for (i = 0; i < PTRS_PER_PGD; i++, pgd++) { | |
286 | addr = start + i * PGDIR_SIZE; | |
a1c76574 | 287 | if (pgd_none(*pgd)) { |
c9465b4e | 288 | note_page(st, addr, 1, pgd_val(*pgd)); |
a1c76574 MR |
289 | } else { |
290 | BUG_ON(pgd_bad(*pgd)); | |
c9465b4e | 291 | walk_pud(st, pgd, addr); |
a1c76574 | 292 | } |
c9465b4e LA |
293 | } |
294 | } | |
295 | ||
296 | static int ptdump_show(struct seq_file *m, void *v) | |
297 | { | |
298 | struct pg_state st = { | |
299 | .seq = m, | |
300 | .marker = address_markers, | |
301 | }; | |
302 | ||
303 | walk_pgd(&st, &init_mm, LOWEST_ADDR); | |
304 | ||
305 | note_page(&st, 0, 0, 0); | |
306 | return 0; | |
307 | } | |
308 | ||
309 | static int ptdump_open(struct inode *inode, struct file *file) | |
310 | { | |
311 | return single_open(file, ptdump_show, NULL); | |
312 | } | |
313 | ||
314 | static const struct file_operations ptdump_fops = { | |
315 | .open = ptdump_open, | |
316 | .read = seq_read, | |
317 | .llseek = seq_lseek, | |
318 | .release = single_release, | |
319 | }; | |
320 | ||
321 | static int ptdump_init(void) | |
322 | { | |
323 | struct dentry *pe; | |
324 | unsigned i, j; | |
325 | ||
326 | for (i = 0; i < ARRAY_SIZE(pg_level); i++) | |
327 | if (pg_level[i].bits) | |
328 | for (j = 0; j < pg_level[i].num; j++) | |
329 | pg_level[i].mask |= pg_level[i].bits[j].mask; | |
330 | ||
326a7803 | 331 | #ifdef CONFIG_SPARSEMEM_VMEMMAP |
c9465b4e LA |
332 | address_markers[VMEMMAP_START_NR].start_address = |
333 | (unsigned long)virt_to_page(PAGE_OFFSET); | |
334 | address_markers[VMEMMAP_END_NR].start_address = | |
335 | (unsigned long)virt_to_page(high_memory); | |
326a7803 | 336 | #endif |
c9465b4e LA |
337 | |
338 | pe = debugfs_create_file("kernel_page_tables", 0400, NULL, NULL, | |
339 | &ptdump_fops); | |
340 | return pe ? 0 : -ENOMEM; | |
341 | } | |
342 | device_initcall(ptdump_init); |