Contributors: 15
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Laura Abbott |
1242 |
67.83% |
5 |
14.29% |
| Steven Price |
220 |
12.02% |
5 |
14.29% |
| Mark Rutland |
115 |
6.28% |
5 |
14.29% |
| Steve Capper |
47 |
2.57% |
2 |
5.71% |
| Jeremy Linton |
46 |
2.51% |
1 |
2.86% |
| Ard Biesheuvel |
42 |
2.29% |
4 |
11.43% |
| Andrey Konovalov |
33 |
1.80% |
1 |
2.86% |
| Mark Brown |
30 |
1.64% |
3 |
8.57% |
| Catalin Marinas |
20 |
1.09% |
1 |
2.86% |
| Anshuman Khandual |
12 |
0.66% |
1 |
2.86% |
| Will Deacon |
11 |
0.60% |
3 |
8.57% |
| Liu hailong |
6 |
0.33% |
1 |
2.86% |
| Greg Kroah-Hartman |
3 |
0.16% |
1 |
2.86% |
| JiSheng Zhang |
2 |
0.11% |
1 |
2.86% |
| Thomas Gleixner |
2 |
0.11% |
1 |
2.86% |
| Total |
1831 |
|
35 |
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2014, The Linux Foundation. All rights reserved.
* 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 and arm implementation:
* (C) Copyright 2008 Intel Corporation
*
* Author: Arjan van de Ven <arjan@linux.intel.com>
*/
#include <linux/debugfs.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/ptdump.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <asm/fixmap.h>
#include <asm/kasan.h>
#include <asm/memory.h>
#include <asm/pgtable-hwdef.h>
#include <asm/ptdump.h>
enum address_markers_idx {
PAGE_OFFSET_NR = 0,
PAGE_END_NR,
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
KASAN_START_NR,
#endif
};
static struct addr_marker address_markers[] = {
{ PAGE_OFFSET, "Linear Mapping start" },
{ 0 /* PAGE_END */, "Linear Mapping end" },
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
{ 0 /* KASAN_SHADOW_START */, "Kasan shadow start" },
{ KASAN_SHADOW_END, "Kasan shadow end" },
#endif
{ BPF_JIT_REGION_START, "BPF start" },
{ BPF_JIT_REGION_END, "BPF end" },
{ MODULES_VADDR, "Modules start" },
{ MODULES_END, "Modules end" },
{ VMALLOC_START, "vmalloc() area" },
{ VMALLOC_END, "vmalloc() end" },
{ FIXADDR_START, "Fixmap start" },
{ FIXADDR_TOP, "Fixmap end" },
{ PCI_IO_START, "PCI I/O start" },
{ PCI_IO_END, "PCI I/O end" },
{ VMEMMAP_START, "vmemmap start" },
{ VMEMMAP_START + VMEMMAP_SIZE, "vmemmap 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); \
})
/*
* The page dumper groups page table entries of the same type into a single
* description. It uses pg_state to track the range information while
* iterating over the pte entries. When the continuity is broken it then
* dumps out a description of the range.
*/
struct pg_state {
struct ptdump_state ptdump;
struct seq_file *seq;
const struct addr_marker *marker;
unsigned long start_address;
int level;
u64 current_prot;
bool check_wx;
unsigned long wx_pages;
unsigned long uxn_pages;
};
struct prot_bits {
u64 mask;
u64 val;
const char *set;
const char *clear;
};
static const struct prot_bits pte_bits[] = {
{
.mask = PTE_VALID,
.val = PTE_VALID,
.set = " ",
.clear = "F",
}, {
.mask = PTE_USER,
.val = PTE_USER,
.set = "USR",
.clear = " ",
}, {
.mask = PTE_RDONLY,
.val = PTE_RDONLY,
.set = "ro",
.clear = "RW",
}, {
.mask = PTE_PXN,
.val = PTE_PXN,
.set = "NX",
.clear = "x ",
}, {
.mask = PTE_SHARED,
.val = PTE_SHARED,
.set = "SHD",
.clear = " ",
}, {
.mask = PTE_AF,
.val = PTE_AF,
.set = "AF",
.clear = " ",
}, {
.mask = PTE_NG,
.val = PTE_NG,
.set = "NG",
.clear = " ",
}, {
.mask = PTE_CONT,
.val = PTE_CONT,
.set = "CON",
.clear = " ",
}, {
.mask = PTE_TABLE_BIT,
.val = PTE_TABLE_BIT,
.set = " ",
.clear = "BLK",
}, {
.mask = PTE_UXN,
.val = PTE_UXN,
.set = "UXN",
.clear = " ",
}, {
.mask = PTE_GP,
.val = PTE_GP,
.set = "GP",
.clear = " ",
}, {
.mask = PTE_ATTRINDX_MASK,
.val = PTE_ATTRINDX(MT_DEVICE_nGnRnE),
.set = "DEVICE/nGnRnE",
}, {
.mask = PTE_ATTRINDX_MASK,
.val = PTE_ATTRINDX(MT_DEVICE_nGnRE),
.set = "DEVICE/nGnRE",
}, {
.mask = PTE_ATTRINDX_MASK,
.val = PTE_ATTRINDX(MT_DEVICE_GRE),
.set = "DEVICE/GRE",
}, {
.mask = PTE_ATTRINDX_MASK,
.val = PTE_ATTRINDX(MT_NORMAL_NC),
.set = "MEM/NORMAL-NC",
}, {
.mask = PTE_ATTRINDX_MASK,
.val = PTE_ATTRINDX(MT_NORMAL),
.set = "MEM/NORMAL",
}, {
.mask = PTE_ATTRINDX_MASK,
.val = PTE_ATTRINDX(MT_NORMAL_TAGGED),
.set = "MEM/NORMAL-TAGGED",
}
};
struct pg_level {
const struct prot_bits *bits;
const char *name;
size_t num;
u64 mask;
};
static struct pg_level pg_level[] = {
{ /* pgd */
.name = "PGD",
.bits = pte_bits,
.num = ARRAY_SIZE(pte_bits),
}, { /* p4d */
.name = "P4D",
.bits = pte_bits,
.num = ARRAY_SIZE(pte_bits),
}, { /* pud */
.name = (CONFIG_PGTABLE_LEVELS > 3) ? "PUD" : "PGD",
.bits = pte_bits,
.num = ARRAY_SIZE(pte_bits),
}, { /* pmd */
.name = (CONFIG_PGTABLE_LEVELS > 2) ? "PMD" : "PGD",
.bits = pte_bits,
.num = ARRAY_SIZE(pte_bits),
}, { /* pte */
.name = "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_uxn(struct pg_state *st, unsigned long addr)
{
if (!st->check_wx)
return;
if ((st->current_prot & PTE_UXN) == PTE_UXN)
return;
WARN_ONCE(1, "arm64/mm: Found non-UXN mapping at address %p/%pS\n",
(void *)st->start_address, (void *)st->start_address);
st->uxn_pages += (addr - st->start_address) / PAGE_SIZE;
}
static void note_prot_wx(struct pg_state *st, unsigned long addr)
{
if (!st->check_wx)
return;
if ((st->current_prot & PTE_RDONLY) == PTE_RDONLY)
return;
if ((st->current_prot & PTE_PXN) == PTE_PXN)
return;
WARN_ONCE(1, "arm64/mm: Found insecure W+X mapping at address %p/%pS\n",
(void *)st->start_address, (void *)st->start_address);
st->wx_pages += (addr - st->start_address) / PAGE_SIZE;
}
static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
u64 val)
{
struct pg_state *st = container_of(pt_st, struct pg_state, ptdump);
static const char units[] = "KMGTPE";
u64 prot = 0;
if (level >= 0)
prot = val & pg_level[level].mask;
if (st->level == -1) {
st->level = level;
st->current_prot = prot;
st->start_address = addr;
pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
} else if (prot != st->current_prot || level != st->level ||
addr >= st->marker[1].start_address) {
const char *unit = units;
unsigned long delta;
if (st->current_prot) {
note_prot_uxn(st, addr);
note_prot_wx(st, addr);
}
pt_dump_seq_printf(st->seq, "0x%016lx-0x%016lx ",
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 %s", delta, *unit,
pg_level[st->level].name);
if (st->current_prot && pg_level[st->level].bits)
dump_prot(st, pg_level[st->level].bits,
pg_level[st->level].num);
pt_dump_seq_puts(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->level = level;
}
if (addr >= st->marker[1].start_address) {
st->marker++;
pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
}
}
void ptdump_walk(struct seq_file *s, struct ptdump_info *info)
{
unsigned long end = ~0UL;
struct pg_state st;
if (info->base_addr < TASK_SIZE_64)
end = TASK_SIZE_64;
st = (struct pg_state){
.seq = s,
.marker = info->markers,
.level = -1,
.ptdump = {
.note_page = note_page,
.range = (struct ptdump_range[]){
{info->base_addr, end},
{0, 0}
}
}
};
ptdump_walk_pgd(&st.ptdump, info->mm, NULL);
}
static void __init 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;
}
static struct ptdump_info kernel_ptdump_info = {
.mm = &init_mm,
.markers = address_markers,
.base_addr = PAGE_OFFSET,
};
void ptdump_check_wx(void)
{
struct pg_state st = {
.seq = NULL,
.marker = (struct addr_marker[]) {
{ 0, NULL},
{ -1, NULL},
},
.level = -1,
.check_wx = true,
.ptdump = {
.note_page = note_page,
.range = (struct ptdump_range[]) {
{PAGE_OFFSET, ~0UL},
{0, 0}
}
}
};
ptdump_walk_pgd(&st.ptdump, &init_mm, NULL);
if (st.wx_pages || st.uxn_pages)
pr_warn("Checked W+X mappings: FAILED, %lu W+X pages found, %lu non-UXN pages found\n",
st.wx_pages, st.uxn_pages);
else
pr_info("Checked W+X mappings: passed, no W+X pages found\n");
}
static int __init ptdump_init(void)
{
address_markers[PAGE_END_NR].start_address = PAGE_END;
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
address_markers[KASAN_START_NR].start_address = KASAN_SHADOW_START;
#endif
ptdump_initialize();
ptdump_debugfs_register(&kernel_ptdump_info, "kernel_page_tables");
return 0;
}
device_initcall(ptdump_init);