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e76e82d7 HC |
1 | #include <linux/seq_file.h> |
2 | #include <linux/debugfs.h> | |
3 | #include <linux/module.h> | |
4 | #include <linux/mm.h> | |
5 | #include <asm/sections.h> | |
6 | #include <asm/pgtable.h> | |
7 | ||
8 | static unsigned long max_addr; | |
9 | ||
10 | struct addr_marker { | |
11 | unsigned long start_address; | |
12 | const char *name; | |
13 | }; | |
14 | ||
15 | enum address_markers_idx { | |
16 | IDENTITY_NR = 0, | |
17 | KERNEL_START_NR, | |
18 | KERNEL_END_NR, | |
19 | VMEMMAP_NR, | |
20 | VMALLOC_NR, | |
c972cc60 | 21 | MODULES_NR, |
e76e82d7 HC |
22 | }; |
23 | ||
24 | static struct addr_marker address_markers[] = { | |
25 | [IDENTITY_NR] = {0, "Identity Mapping"}, | |
26 | [KERNEL_START_NR] = {(unsigned long)&_stext, "Kernel Image Start"}, | |
27 | [KERNEL_END_NR] = {(unsigned long)&_end, "Kernel Image End"}, | |
28 | [VMEMMAP_NR] = {0, "vmemmap Area"}, | |
29 | [VMALLOC_NR] = {0, "vmalloc Area"}, | |
c972cc60 | 30 | [MODULES_NR] = {0, "Modules Area"}, |
e76e82d7 HC |
31 | { -1, NULL } |
32 | }; | |
33 | ||
34 | struct pg_state { | |
35 | int level; | |
36 | unsigned int current_prot; | |
37 | unsigned long start_address; | |
38 | unsigned long current_address; | |
39 | const struct addr_marker *marker; | |
40 | }; | |
41 | ||
42 | static void print_prot(struct seq_file *m, unsigned int pr, int level) | |
43 | { | |
44 | static const char * const level_name[] = | |
45 | { "ASCE", "PGD", "PUD", "PMD", "PTE" }; | |
46 | ||
47 | seq_printf(m, "%s ", level_name[level]); | |
1819ed1f | 48 | if (pr & _PAGE_INVALID) { |
e76e82d7 | 49 | seq_printf(m, "I\n"); |
1819ed1f HC |
50 | return; |
51 | } | |
e5098611 | 52 | seq_printf(m, "%s", pr & _PAGE_PROTECT ? "RO " : "RW "); |
1819ed1f | 53 | seq_putc(m, '\n'); |
e76e82d7 HC |
54 | } |
55 | ||
56 | static void note_page(struct seq_file *m, struct pg_state *st, | |
57 | unsigned int new_prot, int level) | |
58 | { | |
59 | static const char units[] = "KMGTPE"; | |
60 | int width = sizeof(unsigned long) * 2; | |
61 | const char *unit = units; | |
62 | unsigned int prot, cur; | |
63 | unsigned long delta; | |
64 | ||
65 | /* | |
66 | * If we have a "break" in the series, we need to flush the state | |
67 | * that we have now. "break" is either changing perms, levels or | |
68 | * address space marker. | |
69 | */ | |
70 | prot = new_prot; | |
71 | cur = st->current_prot; | |
72 | ||
73 | if (!st->level) { | |
74 | /* First entry */ | |
75 | st->current_prot = new_prot; | |
76 | st->level = level; | |
77 | st->marker = address_markers; | |
78 | seq_printf(m, "---[ %s ]---\n", st->marker->name); | |
79 | } else if (prot != cur || level != st->level || | |
80 | st->current_address >= st->marker[1].start_address) { | |
81 | /* Print the actual finished series */ | |
82 | seq_printf(m, "0x%0*lx-0x%0*lx", | |
83 | width, st->start_address, | |
84 | width, st->current_address); | |
85 | delta = (st->current_address - st->start_address) >> 10; | |
86 | while (!(delta & 0x3ff) && unit[1]) { | |
87 | delta >>= 10; | |
88 | unit++; | |
89 | } | |
90 | seq_printf(m, "%9lu%c ", delta, *unit); | |
91 | print_prot(m, st->current_prot, st->level); | |
92 | if (st->current_address >= st->marker[1].start_address) { | |
93 | st->marker++; | |
94 | seq_printf(m, "---[ %s ]---\n", st->marker->name); | |
95 | } | |
96 | st->start_address = st->current_address; | |
97 | st->current_prot = new_prot; | |
98 | st->level = level; | |
99 | } | |
100 | } | |
101 | ||
102 | /* | |
e5098611 MS |
103 | * The actual page table walker functions. In order to keep the |
104 | * implementation of print_prot() short, we only check and pass | |
105 | * _PAGE_INVALID and _PAGE_PROTECT flags to note_page() if a region, | |
106 | * segment or page table entry is invalid or read-only. | |
107 | * After all it's just a hint that the current level being walked | |
108 | * contains an invalid or read-only entry. | |
e76e82d7 HC |
109 | */ |
110 | static void walk_pte_level(struct seq_file *m, struct pg_state *st, | |
111 | pmd_t *pmd, unsigned long addr) | |
112 | { | |
113 | unsigned int prot; | |
114 | pte_t *pte; | |
115 | int i; | |
116 | ||
117 | for (i = 0; i < PTRS_PER_PTE && addr < max_addr; i++) { | |
118 | st->current_address = addr; | |
119 | pte = pte_offset_kernel(pmd, addr); | |
e5098611 | 120 | prot = pte_val(*pte) & (_PAGE_PROTECT | _PAGE_INVALID); |
e76e82d7 HC |
121 | note_page(m, st, prot, 4); |
122 | addr += PAGE_SIZE; | |
123 | } | |
124 | } | |
125 | ||
126 | static void walk_pmd_level(struct seq_file *m, struct pg_state *st, | |
127 | pud_t *pud, unsigned long addr) | |
128 | { | |
129 | unsigned int prot; | |
130 | pmd_t *pmd; | |
131 | int i; | |
132 | ||
133 | for (i = 0; i < PTRS_PER_PMD && addr < max_addr; i++) { | |
134 | st->current_address = addr; | |
135 | pmd = pmd_offset(pud, addr); | |
136 | if (!pmd_none(*pmd)) { | |
137 | if (pmd_large(*pmd)) { | |
5a79859a | 138 | prot = pmd_val(*pmd) & _SEGMENT_ENTRY_PROTECT; |
e76e82d7 HC |
139 | note_page(m, st, prot, 3); |
140 | } else | |
141 | walk_pte_level(m, st, pmd, addr); | |
142 | } else | |
143 | note_page(m, st, _PAGE_INVALID, 3); | |
144 | addr += PMD_SIZE; | |
145 | } | |
146 | } | |
147 | ||
148 | static void walk_pud_level(struct seq_file *m, struct pg_state *st, | |
149 | pgd_t *pgd, unsigned long addr) | |
150 | { | |
18da2369 | 151 | unsigned int prot; |
e76e82d7 HC |
152 | pud_t *pud; |
153 | int i; | |
154 | ||
155 | for (i = 0; i < PTRS_PER_PUD && addr < max_addr; i++) { | |
156 | st->current_address = addr; | |
157 | pud = pud_offset(pgd, addr); | |
158 | if (!pud_none(*pud)) | |
18da2369 | 159 | if (pud_large(*pud)) { |
5a79859a | 160 | prot = pud_val(*pud) & _REGION3_ENTRY_RO; |
18da2369 HC |
161 | note_page(m, st, prot, 2); |
162 | } else | |
163 | walk_pmd_level(m, st, pud, addr); | |
e76e82d7 HC |
164 | else |
165 | note_page(m, st, _PAGE_INVALID, 2); | |
166 | addr += PUD_SIZE; | |
167 | } | |
168 | } | |
169 | ||
170 | static void walk_pgd_level(struct seq_file *m) | |
171 | { | |
172 | unsigned long addr = 0; | |
173 | struct pg_state st; | |
174 | pgd_t *pgd; | |
175 | int i; | |
176 | ||
177 | memset(&st, 0, sizeof(st)); | |
178 | for (i = 0; i < PTRS_PER_PGD && addr < max_addr; i++) { | |
179 | st.current_address = addr; | |
180 | pgd = pgd_offset_k(addr); | |
181 | if (!pgd_none(*pgd)) | |
182 | walk_pud_level(m, &st, pgd, addr); | |
183 | else | |
184 | note_page(m, &st, _PAGE_INVALID, 1); | |
185 | addr += PGDIR_SIZE; | |
186 | } | |
187 | /* Flush out the last page */ | |
188 | st.current_address = max_addr; | |
189 | note_page(m, &st, 0, 0); | |
190 | } | |
191 | ||
192 | static int ptdump_show(struct seq_file *m, void *v) | |
193 | { | |
194 | walk_pgd_level(m); | |
195 | return 0; | |
196 | } | |
197 | ||
198 | static int ptdump_open(struct inode *inode, struct file *filp) | |
199 | { | |
200 | return single_open(filp, ptdump_show, NULL); | |
201 | } | |
202 | ||
203 | static const struct file_operations ptdump_fops = { | |
204 | .open = ptdump_open, | |
205 | .read = seq_read, | |
206 | .llseek = seq_lseek, | |
207 | .release = single_release, | |
208 | }; | |
209 | ||
210 | static int pt_dump_init(void) | |
211 | { | |
212 | /* | |
213 | * Figure out the maximum virtual address being accessible with the | |
214 | * kernel ASCE. We need this to keep the page table walker functions | |
215 | * from accessing non-existent entries. | |
216 | */ | |
e76e82d7 HC |
217 | max_addr = (S390_lowcore.kernel_asce & _REGION_ENTRY_TYPE_MASK) >> 2; |
218 | max_addr = 1UL << (max_addr * 11 + 31); | |
c972cc60 | 219 | address_markers[MODULES_NR].start_address = MODULES_VADDR; |
e76e82d7 HC |
220 | address_markers[VMEMMAP_NR].start_address = (unsigned long) vmemmap; |
221 | address_markers[VMALLOC_NR].start_address = VMALLOC_START; | |
222 | debugfs_create_file("kernel_page_tables", 0400, NULL, NULL, &ptdump_fops); | |
223 | return 0; | |
224 | } | |
225 | device_initcall(pt_dump_init); |