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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> |
764011ca | 19 | #include <linux/init.h> |
c9465b4e LA |
20 | #include <linux/mm.h> |
21 | #include <linux/sched.h> | |
22 | #include <linux/seq_file.h> | |
23 | ||
24 | #include <asm/fixmap.h> | |
764011ca | 25 | #include <asm/memory.h> |
c9465b4e | 26 | #include <asm/pgtable.h> |
764011ca | 27 | #include <asm/pgtable-hwdef.h> |
c9465b4e LA |
28 | |
29 | #define LOWEST_ADDR (UL(0xffffffffffffffff) << VA_BITS) | |
30 | ||
31 | struct addr_marker { | |
32 | unsigned long start_address; | |
33 | const char *name; | |
34 | }; | |
35 | ||
36 | enum address_markers_idx { | |
37 | VMALLOC_START_NR = 0, | |
38 | VMALLOC_END_NR, | |
39 | #ifdef CONFIG_SPARSEMEM_VMEMMAP | |
40 | VMEMMAP_START_NR, | |
41 | VMEMMAP_END_NR, | |
42 | #endif | |
c9465b4e LA |
43 | FIXADDR_START_NR, |
44 | FIXADDR_END_NR, | |
aa03c428 MR |
45 | PCI_START_NR, |
46 | PCI_END_NR, | |
c9465b4e LA |
47 | MODULES_START_NR, |
48 | MODUELS_END_NR, | |
49 | KERNEL_SPACE_NR, | |
50 | }; | |
51 | ||
52 | static struct addr_marker address_markers[] = { | |
53 | { VMALLOC_START, "vmalloc() Area" }, | |
54 | { VMALLOC_END, "vmalloc() End" }, | |
55 | #ifdef CONFIG_SPARSEMEM_VMEMMAP | |
56 | { 0, "vmemmap start" }, | |
57 | { 0, "vmemmap end" }, | |
58 | #endif | |
c9465b4e LA |
59 | { FIXADDR_START, "Fixmap start" }, |
60 | { FIXADDR_TOP, "Fixmap end" }, | |
aa03c428 MR |
61 | { PCI_IO_START, "PCI I/O start" }, |
62 | { PCI_IO_END, "PCI I/O end" }, | |
c9465b4e LA |
63 | { MODULES_VADDR, "Modules start" }, |
64 | { MODULES_END, "Modules end" }, | |
65 | { PAGE_OFFSET, "Kernel Mapping" }, | |
66 | { -1, NULL }, | |
67 | }; | |
68 | ||
69 | struct pg_state { | |
70 | struct seq_file *seq; | |
71 | const struct addr_marker *marker; | |
72 | unsigned long start_address; | |
73 | unsigned level; | |
74 | u64 current_prot; | |
75 | }; | |
76 | ||
77 | struct prot_bits { | |
78 | u64 mask; | |
79 | u64 val; | |
80 | const char *set; | |
81 | const char *clear; | |
82 | }; | |
83 | ||
84 | static const struct prot_bits pte_bits[] = { | |
85 | { | |
86 | .mask = PTE_USER, | |
87 | .val = PTE_USER, | |
88 | .set = "USR", | |
89 | .clear = " ", | |
90 | }, { | |
91 | .mask = PTE_RDONLY, | |
92 | .val = PTE_RDONLY, | |
93 | .set = "ro", | |
94 | .clear = "RW", | |
95 | }, { | |
96 | .mask = PTE_PXN, | |
97 | .val = PTE_PXN, | |
98 | .set = "NX", | |
99 | .clear = "x ", | |
100 | }, { | |
101 | .mask = PTE_SHARED, | |
102 | .val = PTE_SHARED, | |
103 | .set = "SHD", | |
104 | .clear = " ", | |
105 | }, { | |
106 | .mask = PTE_AF, | |
107 | .val = PTE_AF, | |
108 | .set = "AF", | |
109 | .clear = " ", | |
110 | }, { | |
111 | .mask = PTE_NG, | |
112 | .val = PTE_NG, | |
113 | .set = "NG", | |
114 | .clear = " ", | |
115 | }, { | |
116 | .mask = PTE_UXN, | |
117 | .val = PTE_UXN, | |
118 | .set = "UXN", | |
119 | }, { | |
120 | .mask = PTE_ATTRINDX_MASK, | |
121 | .val = PTE_ATTRINDX(MT_DEVICE_nGnRnE), | |
122 | .set = "DEVICE/nGnRnE", | |
123 | }, { | |
124 | .mask = PTE_ATTRINDX_MASK, | |
125 | .val = PTE_ATTRINDX(MT_DEVICE_nGnRE), | |
126 | .set = "DEVICE/nGnRE", | |
127 | }, { | |
128 | .mask = PTE_ATTRINDX_MASK, | |
129 | .val = PTE_ATTRINDX(MT_DEVICE_GRE), | |
130 | .set = "DEVICE/GRE", | |
131 | }, { | |
132 | .mask = PTE_ATTRINDX_MASK, | |
133 | .val = PTE_ATTRINDX(MT_NORMAL_NC), | |
134 | .set = "MEM/NORMAL-NC", | |
135 | }, { | |
136 | .mask = PTE_ATTRINDX_MASK, | |
137 | .val = PTE_ATTRINDX(MT_NORMAL), | |
138 | .set = "MEM/NORMAL", | |
139 | } | |
140 | }; | |
141 | ||
142 | struct pg_level { | |
143 | const struct prot_bits *bits; | |
144 | size_t num; | |
145 | u64 mask; | |
146 | }; | |
147 | ||
148 | static struct pg_level pg_level[] = { | |
149 | { | |
150 | }, { /* pgd */ | |
151 | .bits = pte_bits, | |
152 | .num = ARRAY_SIZE(pte_bits), | |
153 | }, { /* pud */ | |
154 | .bits = pte_bits, | |
155 | .num = ARRAY_SIZE(pte_bits), | |
156 | }, { /* pmd */ | |
157 | .bits = pte_bits, | |
158 | .num = ARRAY_SIZE(pte_bits), | |
159 | }, { /* pte */ | |
160 | .bits = pte_bits, | |
161 | .num = ARRAY_SIZE(pte_bits), | |
162 | }, | |
163 | }; | |
164 | ||
165 | static void dump_prot(struct pg_state *st, const struct prot_bits *bits, | |
166 | size_t num) | |
167 | { | |
168 | unsigned i; | |
169 | ||
170 | for (i = 0; i < num; i++, bits++) { | |
171 | const char *s; | |
172 | ||
173 | if ((st->current_prot & bits->mask) == bits->val) | |
174 | s = bits->set; | |
175 | else | |
176 | s = bits->clear; | |
177 | ||
178 | if (s) | |
179 | seq_printf(st->seq, " %s", s); | |
180 | } | |
181 | } | |
182 | ||
183 | static void note_page(struct pg_state *st, unsigned long addr, unsigned level, | |
184 | u64 val) | |
185 | { | |
186 | static const char units[] = "KMGTPE"; | |
187 | u64 prot = val & pg_level[level].mask; | |
188 | ||
c9465b4e LA |
189 | if (!st->level) { |
190 | st->level = level; | |
191 | st->current_prot = prot; | |
192 | st->start_address = addr; | |
193 | seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); | |
194 | } else if (prot != st->current_prot || level != st->level || | |
195 | addr >= st->marker[1].start_address) { | |
196 | const char *unit = units; | |
197 | unsigned long delta; | |
198 | ||
199 | if (st->current_prot) { | |
200 | seq_printf(st->seq, "0x%16lx-0x%16lx ", | |
201 | st->start_address, addr); | |
202 | ||
203 | delta = (addr - st->start_address) >> 10; | |
204 | while (!(delta & 1023) && unit[1]) { | |
205 | delta >>= 10; | |
206 | unit++; | |
207 | } | |
208 | seq_printf(st->seq, "%9lu%c", delta, *unit); | |
209 | if (pg_level[st->level].bits) | |
210 | dump_prot(st, pg_level[st->level].bits, | |
211 | pg_level[st->level].num); | |
212 | seq_puts(st->seq, "\n"); | |
213 | } | |
214 | ||
215 | if (addr >= st->marker[1].start_address) { | |
216 | st->marker++; | |
217 | seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); | |
218 | } | |
219 | ||
220 | st->start_address = addr; | |
221 | st->current_prot = prot; | |
222 | st->level = level; | |
223 | } | |
224 | ||
225 | if (addr >= st->marker[1].start_address) { | |
226 | st->marker++; | |
227 | seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); | |
228 | } | |
229 | ||
230 | } | |
231 | ||
232 | static void walk_pte(struct pg_state *st, pmd_t *pmd, unsigned long start) | |
233 | { | |
234 | pte_t *pte = pte_offset_kernel(pmd, 0); | |
235 | unsigned long addr; | |
236 | unsigned i; | |
237 | ||
238 | for (i = 0; i < PTRS_PER_PTE; i++, pte++) { | |
239 | addr = start + i * PAGE_SIZE; | |
240 | note_page(st, addr, 4, pte_val(*pte)); | |
241 | } | |
242 | } | |
243 | ||
244 | static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start) | |
245 | { | |
246 | pmd_t *pmd = pmd_offset(pud, 0); | |
247 | unsigned long addr; | |
248 | unsigned i; | |
249 | ||
250 | for (i = 0; i < PTRS_PER_PMD; i++, pmd++) { | |
251 | addr = start + i * PMD_SIZE; | |
252 | if (pmd_none(*pmd) || pmd_sect(*pmd) || pmd_bad(*pmd)) | |
253 | note_page(st, addr, 3, pmd_val(*pmd)); | |
254 | else | |
255 | walk_pte(st, pmd, addr); | |
256 | } | |
257 | } | |
258 | ||
259 | static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start) | |
260 | { | |
261 | pud_t *pud = pud_offset(pgd, 0); | |
262 | unsigned long addr; | |
263 | unsigned i; | |
264 | ||
265 | for (i = 0; i < PTRS_PER_PUD; i++, pud++) { | |
266 | addr = start + i * PUD_SIZE; | |
267 | if (pud_none(*pud) || pud_sect(*pud) || pud_bad(*pud)) | |
268 | note_page(st, addr, 2, pud_val(*pud)); | |
269 | else | |
270 | walk_pmd(st, pud, addr); | |
271 | } | |
272 | } | |
273 | ||
274 | static void walk_pgd(struct pg_state *st, struct mm_struct *mm, unsigned long start) | |
275 | { | |
35545f0c | 276 | pgd_t *pgd = pgd_offset(mm, 0UL); |
c9465b4e LA |
277 | unsigned i; |
278 | unsigned long addr; | |
279 | ||
280 | for (i = 0; i < PTRS_PER_PGD; i++, pgd++) { | |
281 | addr = start + i * PGDIR_SIZE; | |
282 | if (pgd_none(*pgd) || pgd_bad(*pgd)) | |
283 | note_page(st, addr, 1, pgd_val(*pgd)); | |
284 | else | |
285 | walk_pud(st, pgd, addr); | |
286 | } | |
287 | } | |
288 | ||
289 | static int ptdump_show(struct seq_file *m, void *v) | |
290 | { | |
291 | struct pg_state st = { | |
292 | .seq = m, | |
293 | .marker = address_markers, | |
294 | }; | |
295 | ||
296 | walk_pgd(&st, &init_mm, LOWEST_ADDR); | |
297 | ||
298 | note_page(&st, 0, 0, 0); | |
299 | return 0; | |
300 | } | |
301 | ||
302 | static int ptdump_open(struct inode *inode, struct file *file) | |
303 | { | |
304 | return single_open(file, ptdump_show, NULL); | |
305 | } | |
306 | ||
307 | static const struct file_operations ptdump_fops = { | |
308 | .open = ptdump_open, | |
309 | .read = seq_read, | |
310 | .llseek = seq_lseek, | |
311 | .release = single_release, | |
312 | }; | |
313 | ||
314 | static int ptdump_init(void) | |
315 | { | |
316 | struct dentry *pe; | |
317 | unsigned i, j; | |
318 | ||
319 | for (i = 0; i < ARRAY_SIZE(pg_level); i++) | |
320 | if (pg_level[i].bits) | |
321 | for (j = 0; j < pg_level[i].num; j++) | |
322 | pg_level[i].mask |= pg_level[i].bits[j].mask; | |
323 | ||
324 | address_markers[VMEMMAP_START_NR].start_address = | |
325 | (unsigned long)virt_to_page(PAGE_OFFSET); | |
326 | address_markers[VMEMMAP_END_NR].start_address = | |
327 | (unsigned long)virt_to_page(high_memory); | |
328 | ||
329 | pe = debugfs_create_file("kernel_page_tables", 0400, NULL, NULL, | |
330 | &ptdump_fops); | |
331 | return pe ? 0 : -ENOMEM; | |
332 | } | |
333 | device_initcall(ptdump_init); |