453 lines
9.9 KiB
C
453 lines
9.9 KiB
C
|
// SPDX-License-Identifier: GPL-2.0-only
|
||
|
|
/*
|
||
|
|
* Debug helper to dump the current kernel pagetables of the system
|
||
|
|
* so that we can see what the various memory ranges are set to.
|
||
|
|
*
|
||
|
|
* Derived from x86 implementation:
|
||
|
|
* (C) Copyright 2008 Intel Corporation
|
||
|
|
*
|
||
|
|
* Author: Arjan van de Ven <arjan@linux.intel.com>
|
||
|
|
*/
|
||
|
|
#include <linux/debugfs.h>
|
||
|
|
#include <linux/fs.h>
|
||
|
|
#include <linux/mm.h>
|
||
|
|
#include <linux/seq_file.h>
|
||
|
|
|
||
|
|
#include <asm/domain.h>
|
||
|
|
#include <asm/fixmap.h>
|
||
|
|
#include <asm/memory.h>
|
||
|
|
#include <asm/pgtable.h>
|
||
|
|
#include <asm/ptdump.h>
|
||
|
|
|
||
|
|
static struct addr_marker address_markers[] = {
|
||
|
|
{ MODULES_VADDR, "Modules" },
|
||
|
|
{ PAGE_OFFSET, "Kernel Mapping" },
|
||
|
|
{ 0, "vmalloc() Area" },
|
||
|
|
{ VMALLOC_END, "vmalloc() End" },
|
||
|
|
{ FIXADDR_START, "Fixmap Area" },
|
||
|
|
{ VECTORS_BASE, "Vectors" },
|
||
|
|
{ VECTORS_BASE + PAGE_SIZE * 2, "Vectors End" },
|
||
|
|
{ -1, NULL },
|
||
|
|
};
|
||
|
|
|
||
|
|
#define pt_dump_seq_printf(m, fmt, args...) \
|
||
|
|
({ \
|
||
|
|
if (m) \
|
||
|
|
seq_printf(m, fmt, ##args); \
|
||
|
|
})
|
||
|
|
|
||
|
|
#define pt_dump_seq_puts(m, fmt) \
|
||
|
|
({ \
|
||
|
|
if (m) \
|
||
|
|
seq_printf(m, fmt); \
|
||
|
|
})
|
||
|
|
|
||
|
|
struct pg_state {
|
||
|
|
struct seq_file *seq;
|
||
|
|
const struct addr_marker *marker;
|
||
|
|
unsigned long start_address;
|
||
|
|
unsigned level;
|
||
|
|
u64 current_prot;
|
||
|
|
bool check_wx;
|
||
|
|
unsigned long wx_pages;
|
||
|
|
const char *current_domain;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct prot_bits {
|
||
|
|
u64 mask;
|
||
|
|
u64 val;
|
||
|
|
const char *set;
|
||
|
|
const char *clear;
|
||
|
|
bool ro_bit;
|
||
|
|
bool nx_bit;
|
||
|
|
};
|
||
|
|
|
||
|
|
static const struct prot_bits pte_bits[] = {
|
||
|
|
{
|
||
|
|
.mask = L_PTE_USER,
|
||
|
|
.val = L_PTE_USER,
|
||
|
|
.set = "USR",
|
||
|
|
.clear = " ",
|
||
|
|
}, {
|
||
|
|
.mask = L_PTE_RDONLY,
|
||
|
|
.val = L_PTE_RDONLY,
|
||
|
|
.set = "ro",
|
||
|
|
.clear = "RW",
|
||
|
|
.ro_bit = true,
|
||
|
|
}, {
|
||
|
|
.mask = L_PTE_XN,
|
||
|
|
.val = L_PTE_XN,
|
||
|
|
.set = "NX",
|
||
|
|
.clear = "x ",
|
||
|
|
.nx_bit = true,
|
||
|
|
}, {
|
||
|
|
.mask = L_PTE_SHARED,
|
||
|
|
.val = L_PTE_SHARED,
|
||
|
|
.set = "SHD",
|
||
|
|
.clear = " ",
|
||
|
|
}, {
|
||
|
|
.mask = L_PTE_MT_MASK,
|
||
|
|
.val = L_PTE_MT_UNCACHED,
|
||
|
|
.set = "SO/UNCACHED",
|
||
|
|
}, {
|
||
|
|
.mask = L_PTE_MT_MASK,
|
||
|
|
.val = L_PTE_MT_BUFFERABLE,
|
||
|
|
.set = "MEM/BUFFERABLE/WC",
|
||
|
|
}, {
|
||
|
|
.mask = L_PTE_MT_MASK,
|
||
|
|
.val = L_PTE_MT_WRITETHROUGH,
|
||
|
|
.set = "MEM/CACHED/WT",
|
||
|
|
}, {
|
||
|
|
.mask = L_PTE_MT_MASK,
|
||
|
|
.val = L_PTE_MT_WRITEBACK,
|
||
|
|
.set = "MEM/CACHED/WBRA",
|
||
|
|
#ifndef CONFIG_ARM_LPAE
|
||
|
|
}, {
|
||
|
|
.mask = L_PTE_MT_MASK,
|
||
|
|
.val = L_PTE_MT_MINICACHE,
|
||
|
|
.set = "MEM/MINICACHE",
|
||
|
|
#endif
|
||
|
|
}, {
|
||
|
|
.mask = L_PTE_MT_MASK,
|
||
|
|
.val = L_PTE_MT_WRITEALLOC,
|
||
|
|
.set = "MEM/CACHED/WBWA",
|
||
|
|
}, {
|
||
|
|
.mask = L_PTE_MT_MASK,
|
||
|
|
.val = L_PTE_MT_DEV_SHARED,
|
||
|
|
.set = "DEV/SHARED",
|
||
|
|
#ifndef CONFIG_ARM_LPAE
|
||
|
|
}, {
|
||
|
|
.mask = L_PTE_MT_MASK,
|
||
|
|
.val = L_PTE_MT_DEV_NONSHARED,
|
||
|
|
.set = "DEV/NONSHARED",
|
||
|
|
#endif
|
||
|
|
}, {
|
||
|
|
.mask = L_PTE_MT_MASK,
|
||
|
|
.val = L_PTE_MT_DEV_WC,
|
||
|
|
.set = "DEV/WC",
|
||
|
|
}, {
|
||
|
|
.mask = L_PTE_MT_MASK,
|
||
|
|
.val = L_PTE_MT_DEV_CACHED,
|
||
|
|
.set = "DEV/CACHED",
|
||
|
|
},
|
||
|
|
};
|
||
|
|
|
||
|
|
static const struct prot_bits section_bits[] = {
|
||
|
|
#ifdef CONFIG_ARM_LPAE
|
||
|
|
{
|
||
|
|
.mask = PMD_SECT_USER,
|
||
|
|
.val = PMD_SECT_USER,
|
||
|
|
.set = "USR",
|
||
|
|
}, {
|
||
|
|
.mask = L_PMD_SECT_RDONLY | PMD_SECT_AP2,
|
||
|
|
.val = L_PMD_SECT_RDONLY | PMD_SECT_AP2,
|
||
|
|
.set = "ro",
|
||
|
|
.clear = "RW",
|
||
|
|
.ro_bit = true,
|
||
|
|
#elif __LINUX_ARM_ARCH__ >= 6
|
||
|
|
{
|
||
|
|
.mask = PMD_SECT_APX | PMD_SECT_AP_READ | PMD_SECT_AP_WRITE,
|
||
|
|
.val = PMD_SECT_APX | PMD_SECT_AP_WRITE,
|
||
|
|
.set = " ro",
|
||
|
|
.ro_bit = true,
|
||
|
|
}, {
|
||
|
|
.mask = PMD_SECT_APX | PMD_SECT_AP_READ | PMD_SECT_AP_WRITE,
|
||
|
|
.val = PMD_SECT_AP_WRITE,
|
||
|
|
.set = " RW",
|
||
|
|
}, {
|
||
|
|
.mask = PMD_SECT_APX | PMD_SECT_AP_READ | PMD_SECT_AP_WRITE,
|
||
|
|
.val = PMD_SECT_AP_READ,
|
||
|
|
.set = "USR ro",
|
||
|
|
}, {
|
||
|
|
.mask = PMD_SECT_APX | PMD_SECT_AP_READ | PMD_SECT_AP_WRITE,
|
||
|
|
.val = PMD_SECT_AP_READ | PMD_SECT_AP_WRITE,
|
||
|
|
.set = "USR RW",
|
||
|
|
#else /* ARMv4/ARMv5 */
|
||
|
|
/* These are approximate */
|
||
|
|
{
|
||
|
|
.mask = PMD_SECT_AP_READ | PMD_SECT_AP_WRITE,
|
||
|
|
.val = 0,
|
||
|
|
.set = " ro",
|
||
|
|
.ro_bit = true,
|
||
|
|
}, {
|
||
|
|
.mask = PMD_SECT_AP_READ | PMD_SECT_AP_WRITE,
|
||
|
|
.val = PMD_SECT_AP_WRITE,
|
||
|
|
.set = " RW",
|
||
|
|
}, {
|
||
|
|
.mask = PMD_SECT_AP_READ | PMD_SECT_AP_WRITE,
|
||
|
|
.val = PMD_SECT_AP_READ,
|
||
|
|
.set = "USR ro",
|
||
|
|
}, {
|
||
|
|
.mask = PMD_SECT_AP_READ | PMD_SECT_AP_WRITE,
|
||
|
|
.val = PMD_SECT_AP_READ | PMD_SECT_AP_WRITE,
|
||
|
|
.set = "USR RW",
|
||
|
|
#endif
|
||
|
|
}, {
|
||
|
|
.mask = PMD_SECT_XN,
|
||
|
|
.val = PMD_SECT_XN,
|
||
|
|
.set = "NX",
|
||
|
|
.clear = "x ",
|
||
|
|
.nx_bit = true,
|
||
|
|
}, {
|
||
|
|
.mask = PMD_SECT_S,
|
||
|
|
.val = PMD_SECT_S,
|
||
|
|
.set = "SHD",
|
||
|
|
.clear = " ",
|
||
|
|
},
|
||
|
|
};
|
||
|
|
|
||
|
|
struct pg_level {
|
||
|
|
const struct prot_bits *bits;
|
||
|
|
size_t num;
|
||
|
|
u64 mask;
|
||
|
|
const struct prot_bits *ro_bit;
|
||
|
|
const struct prot_bits *nx_bit;
|
||
|
|
};
|
||
|
|
|
||
|
|
static struct pg_level pg_level[] = {
|
||
|
|
{
|
||
|
|
}, { /* pgd */
|
||
|
|
}, { /* pud */
|
||
|
|
}, { /* pmd */
|
||
|
|
.bits = section_bits,
|
||
|
|
.num = ARRAY_SIZE(section_bits),
|
||
|
|
}, { /* pte */
|
||
|
|
.bits = pte_bits,
|
||
|
|
.num = ARRAY_SIZE(pte_bits),
|
||
|
|
},
|
||
|
|
};
|
||
|
|
|
||
|
|
static void dump_prot(struct pg_state *st, const struct prot_bits *bits, size_t num)
|
||
|
|
{
|
||
|
|
unsigned i;
|
||
|
|
|
||
|
|
for (i = 0; i < num; i++, bits++) {
|
||
|
|
const char *s;
|
||
|
|
|
||
|
|
if ((st->current_prot & bits->mask) == bits->val)
|
||
|
|
s = bits->set;
|
||
|
|
else
|
||
|
|
s = bits->clear;
|
||
|
|
|
||
|
|
if (s)
|
||
|
|
pt_dump_seq_printf(st->seq, " %s", s);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
static void note_prot_wx(struct pg_state *st, unsigned long addr)
|
||
|
|
{
|
||
|
|
if (!st->check_wx)
|
||
|
|
return;
|
||
|
|
if ((st->current_prot & pg_level[st->level].ro_bit->mask) ==
|
||
|
|
pg_level[st->level].ro_bit->val)
|
||
|
|
return;
|
||
|
|
if ((st->current_prot & pg_level[st->level].nx_bit->mask) ==
|
||
|
|
pg_level[st->level].nx_bit->val)
|
||
|
|
return;
|
||
|
|
|
||
|
|
WARN_ONCE(1, "arm/mm: Found insecure W+X mapping at address %pS\n",
|
||
|
|
(void *)st->start_address);
|
||
|
|
|
||
|
|
st->wx_pages += (addr - st->start_address) / PAGE_SIZE;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void note_page(struct pg_state *st, unsigned long addr,
|
||
|
|
unsigned int level, u64 val, const char *domain)
|
||
|
|
{
|
||
|
|
static const char units[] = "KMGTPE";
|
||
|
|
u64 prot = val & pg_level[level].mask;
|
||
|
|
|
||
|
|
if (!st->level) {
|
||
|
|
st->level = level;
|
||
|
|
st->current_prot = prot;
|
||
|
|
st->current_domain = domain;
|
||
|
|
pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
|
||
|
|
} else if (prot != st->current_prot || level != st->level ||
|
||
|
|
domain != st->current_domain ||
|
||
|
|
addr >= st->marker[1].start_address) {
|
||
|
|
const char *unit = units;
|
||
|
|
unsigned long delta;
|
||
|
|
|
||
|
|
if (st->current_prot) {
|
||
|
|
note_prot_wx(st, addr);
|
||
|
|
pt_dump_seq_printf(st->seq, "0x%08lx-0x%08lx ",
|
||
|
|
st->start_address, addr);
|
||
|
|
|
||
|
|
delta = (addr - st->start_address) >> 10;
|
||
|
|
while (!(delta & 1023) && unit[1]) {
|
||
|
|
delta >>= 10;
|
||
|
|
unit++;
|
||
|
|
}
|
||
|
|
pt_dump_seq_printf(st->seq, "%9lu%c", delta, *unit);
|
||
|
|
if (st->current_domain)
|
||
|
|
pt_dump_seq_printf(st->seq, " %s",
|
||
|
|
st->current_domain);
|
||
|
|
if (pg_level[st->level].bits)
|
||
|
|
dump_prot(st, pg_level[st->level].bits, pg_level[st->level].num);
|
||
|
|
pt_dump_seq_printf(st->seq, "\n");
|
||
|
|
}
|
||
|
|
|
||
|
|
if (addr >= st->marker[1].start_address) {
|
||
|
|
st->marker++;
|
||
|
|
pt_dump_seq_printf(st->seq, "---[ %s ]---\n",
|
||
|
|
st->marker->name);
|
||
|
|
}
|
||
|
|
st->start_address = addr;
|
||
|
|
st->current_prot = prot;
|
||
|
|
st->current_domain = domain;
|
||
|
|
st->level = level;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
static void walk_pte(struct pg_state *st, pmd_t *pmd, unsigned long start,
|
||
|
|
const char *domain)
|
||
|
|
{
|
||
|
|
pte_t *pte = pte_offset_kernel(pmd, 0);
|
||
|
|
unsigned long addr;
|
||
|
|
unsigned i;
|
||
|
|
|
||
|
|
for (i = 0; i < PTRS_PER_PTE; i++, pte++) {
|
||
|
|
addr = start + i * PAGE_SIZE;
|
||
|
|
note_page(st, addr, 4, pte_val(*pte), domain);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
static const char *get_domain_name(pmd_t *pmd)
|
||
|
|
{
|
||
|
|
#ifndef CONFIG_ARM_LPAE
|
||
|
|
switch (pmd_val(*pmd) & PMD_DOMAIN_MASK) {
|
||
|
|
case PMD_DOMAIN(DOMAIN_KERNEL):
|
||
|
|
return "KERNEL ";
|
||
|
|
case PMD_DOMAIN(DOMAIN_USER):
|
||
|
|
return "USER ";
|
||
|
|
case PMD_DOMAIN(DOMAIN_IO):
|
||
|
|
return "IO ";
|
||
|
|
case PMD_DOMAIN(DOMAIN_VECTORS):
|
||
|
|
return "VECTORS";
|
||
|
|
default:
|
||
|
|
return "unknown";
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start)
|
||
|
|
{
|
||
|
|
pmd_t *pmd = pmd_offset(pud, 0);
|
||
|
|
unsigned long addr;
|
||
|
|
unsigned i;
|
||
|
|
const char *domain;
|
||
|
|
|
||
|
|
for (i = 0; i < PTRS_PER_PMD; i++, pmd++) {
|
||
|
|
addr = start + i * PMD_SIZE;
|
||
|
|
domain = get_domain_name(pmd);
|
||
|
|
if (pmd_none(*pmd) || pmd_large(*pmd) || !pmd_present(*pmd))
|
||
|
|
note_page(st, addr, 3, pmd_val(*pmd), domain);
|
||
|
|
else
|
||
|
|
walk_pte(st, pmd, addr, domain);
|
||
|
|
|
||
|
|
if (SECTION_SIZE < PMD_SIZE && pmd_large(pmd[1])) {
|
||
|
|
addr += SECTION_SIZE;
|
||
|
|
pmd++;
|
||
|
|
domain = get_domain_name(pmd);
|
||
|
|
note_page(st, addr, 3, pmd_val(*pmd), domain);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start)
|
||
|
|
{
|
||
|
|
pud_t *pud = pud_offset(pgd, 0);
|
||
|
|
unsigned long addr;
|
||
|
|
unsigned i;
|
||
|
|
|
||
|
|
for (i = 0; i < PTRS_PER_PUD; i++, pud++) {
|
||
|
|
addr = start + i * PUD_SIZE;
|
||
|
|
if (!pud_none(*pud)) {
|
||
|
|
walk_pmd(st, pud, addr);
|
||
|
|
} else {
|
||
|
|
note_page(st, addr, 2, pud_val(*pud), NULL);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
static void walk_pgd(struct pg_state *st, struct mm_struct *mm,
|
||
|
|
unsigned long start)
|
||
|
|
{
|
||
|
|
pgd_t *pgd = pgd_offset(mm, 0UL);
|
||
|
|
unsigned i;
|
||
|
|
unsigned long addr;
|
||
|
|
|
||
|
|
for (i = 0; i < PTRS_PER_PGD; i++, pgd++) {
|
||
|
|
addr = start + i * PGDIR_SIZE;
|
||
|
|
if (!pgd_none(*pgd)) {
|
||
|
|
walk_pud(st, pgd, addr);
|
||
|
|
} else {
|
||
|
|
note_page(st, addr, 1, pgd_val(*pgd), NULL);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void ptdump_walk_pgd(struct seq_file *m, struct ptdump_info *info)
|
||
|
|
{
|
||
|
|
struct pg_state st = {
|
||
|
|
.seq = m,
|
||
|
|
.marker = info->markers,
|
||
|
|
.check_wx = false,
|
||
|
|
};
|
||
|
|
|
||
|
|
walk_pgd(&st, info->mm, info->base_addr);
|
||
|
|
note_page(&st, 0, 0, 0, NULL);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void ptdump_initialize(void)
|
||
|
|
{
|
||
|
|
unsigned i, j;
|
||
|
|
|
||
|
|
for (i = 0; i < ARRAY_SIZE(pg_level); i++)
|
||
|
|
if (pg_level[i].bits)
|
||
|
|
for (j = 0; j < pg_level[i].num; j++) {
|
||
|
|
pg_level[i].mask |= pg_level[i].bits[j].mask;
|
||
|
|
if (pg_level[i].bits[j].ro_bit)
|
||
|
|
pg_level[i].ro_bit = &pg_level[i].bits[j];
|
||
|
|
if (pg_level[i].bits[j].nx_bit)
|
||
|
|
pg_level[i].nx_bit = &pg_level[i].bits[j];
|
||
|
|
}
|
||
|
|
|
||
|
|
address_markers[2].start_address = VMALLOC_START;
|
||
|
|
}
|
||
|
|
|
||
|
|
static struct ptdump_info kernel_ptdump_info = {
|
||
|
|
.mm = &init_mm,
|
||
|
|
.markers = address_markers,
|
||
|
|
.base_addr = 0,
|
||
|
|
};
|
||
|
|
|
||
|
|
void ptdump_check_wx(void)
|
||
|
|
{
|
||
|
|
struct pg_state st = {
|
||
|
|
.seq = NULL,
|
||
|
|
.marker = (struct addr_marker[]) {
|
||
|
|
{ 0, NULL},
|
||
|
|
{ -1, NULL},
|
||
|
|
},
|
||
|
|
.check_wx = true,
|
||
|
|
};
|
||
|
|
|
||
|
|
walk_pgd(&st, &init_mm, 0);
|
||
|
|
note_page(&st, 0, 0, 0, NULL);
|
||
|
|
if (st.wx_pages)
|
||
|
|
pr_warn("Checked W+X mappings: FAILED, %lu W+X pages found\n",
|
||
|
|
st.wx_pages);
|
||
|
|
else
|
||
|
|
pr_info("Checked W+X mappings: passed, no W+X pages found\n");
|
||
|
|
}
|
||
|
|
|
||
|
|
static int ptdump_init(void)
|
||
|
|
{
|
||
|
|
ptdump_initialize();
|
||
|
|
ptdump_debugfs_register(&kernel_ptdump_info, "kernel_page_tables");
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
__initcall(ptdump_init);
|