245 lines
6 KiB
C
245 lines
6 KiB
C
#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,
|
|
#ifdef CONFIG_64BIT
|
|
MODULES_NR,
|
|
#endif
|
|
};
|
|
|
|
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"},
|
|
#ifdef CONFIG_64BIT
|
|
[MODULES_NR] = {0, "Modules Area"},
|
|
#endif
|
|
{ -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;
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_64BIT
|
|
#define _PMD_PROT_MASK _SEGMENT_ENTRY_PROTECT
|
|
#else
|
|
#define _PMD_PROT_MASK 0
|
|
#endif
|
|
|
|
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) & _PMD_PROT_MASK;
|
|
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;
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_64BIT
|
|
#define _PUD_PROT_MASK _REGION3_ENTRY_RO
|
|
#else
|
|
#define _PUD_PROT_MASK 0
|
|
#endif
|
|
|
|
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) & _PUD_PROT_MASK;
|
|
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.
|
|
*/
|
|
#ifdef CONFIG_32BIT
|
|
max_addr = 1UL << 31;
|
|
#else
|
|
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;
|
|
#endif
|
|
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);
|