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