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arm64: mm: convert mm/dump.c to use walk_page_range()

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Now walk_page_range() can walk kernel page tables, we can switch the arm64
ptdump code over to using it, simplifying the code.

Link: http://lkml.kernel.org/r/20191218162402.45610-22-steven.price@arm.com
Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zong Li <zong.li@sifive.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Steven Price 2020-02-03 17:36:29 -08:00 committed by Linus Torvalds
parent 2ae27137b2
commit 102f45fdbe
8 changed files with 50 additions and 107 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

1
arch/arm64/Kconfig
View file

@ -104,6 +104,7 @@ config ARM64
select GENERIC_IRQ_SHOW
select GENERIC_IRQ_SHOW_LEVEL
select GENERIC_PCI_IOMAP
select GENERIC_PTDUMP
select GENERIC_SCHED_CLOCK
select GENERIC_SMP_IDLE_THREAD
select GENERIC_STRNCPY_FROM_USER

19
arch/arm64/Kconfig.debug
View file

@ -1,22 +1,5 @@
# SPDX-License-Identifier: GPL-2.0-only
config ARM64_PTDUMP_CORE
def_bool n
config ARM64_PTDUMP_DEBUGFS
bool "Export kernel pagetable layout to userspace via debugfs"
depends on DEBUG_KERNEL
select ARM64_PTDUMP_CORE
select DEBUG_FS
help
Say Y here if you want to show the kernel pagetable layout in a
debugfs file. This information is only useful for kernel developers
who are working in architecture specific areas of the kernel.
It is probably not a good idea to enable this feature in a production
kernel.
If in doubt, say N.
config PID_IN_CONTEXTIDR
bool "Write the current PID to the CONTEXTIDR register"
help
@ -42,7 +25,7 @@ config ARM64_RANDOMIZE_TEXT_OFFSET
config DEBUG_WX
bool "Warn on W+X mappings at boot"
select ARM64_PTDUMP_CORE
select PTDUMP_CORE
---help---
Generate a warning if any W+X mappings are found at boot.

8
arch/arm64/include/asm/ptdump.h
View file

@ -5,7 +5,7 @@
#ifndef __ASM_PTDUMP_H
#define __ASM_PTDUMP_H
#ifdef CONFIG_ARM64_PTDUMP_CORE
#ifdef CONFIG_PTDUMP_CORE
#include <linux/mm_types.h>
#include <linux/seq_file.h>
@ -21,15 +21,15 @@ struct ptdump_info {
unsigned long base_addr;
};
void ptdump_walk_pgd(struct seq_file *s, struct ptdump_info *info);
#ifdef CONFIG_ARM64_PTDUMP_DEBUGFS
void ptdump_walk(struct seq_file *s, struct ptdump_info *info);
#ifdef CONFIG_PTDUMP_DEBUGFS
void ptdump_debugfs_register(struct ptdump_info *info, const char *name);
#else
static inline void ptdump_debugfs_register(struct ptdump_info *info,
const char *name) { }
#endif
void ptdump_check_wx(void);
#endif /* CONFIG_ARM64_PTDUMP_CORE */
#endif /* CONFIG_PTDUMP_CORE */
#ifdef CONFIG_DEBUG_WX
#define debug_checkwx() ptdump_check_wx()

4
arch/arm64/mm/Makefile
View file

@ -4,8 +4,8 @@ obj-y := dma-mapping.o extable.o fault.o init.o \
ioremap.o mmap.o pgd.o mmu.o \
context.o proc.o pageattr.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_ARM64_PTDUMP_CORE) += dump.o
obj-$(CONFIG_ARM64_PTDUMP_DEBUGFS) += ptdump_debugfs.o
obj-$(CONFIG_PTDUMP_CORE) += dump.o
obj-$(CONFIG_PTDUMP_DEBUGFS) += ptdump_debugfs.o
obj-$(CONFIG_NUMA) += numa.o
obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o
KASAN_SANITIZE_physaddr.o += n

117
arch/arm64/mm/dump.c
View file

@ -15,6 +15,7 @@
#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>
@ -75,10 +76,11 @@ static struct addr_marker address_markers[] = {
* 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;
unsigned level;
int level;
u64 current_prot;
bool check_wx;
unsigned long wx_pages;
@ -179,6 +181,10 @@ static struct pg_level pg_level[] = {
.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,
@ -241,11 +247,15 @@ static void note_prot_wx(struct pg_state *st, unsigned long addr)
st->wx_pages += (addr - st->start_address) / PAGE_SIZE;
}
static void note_page(struct pg_state *st, unsigned long addr, unsigned level,
u64 val)
static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
unsigned long val)
{
struct pg_state *st = container_of(pt_st, struct pg_state, ptdump);
static const char units[] = "KMGTPE";
u64 prot = val & pg_level[level].mask;
u64 prot = 0;
if (level >= 0)
prot = val & pg_level[level].mask;
if (!st->level) {
st->level = level;
@ -293,85 +303,27 @@ static void note_page(struct pg_state *st, unsigned long addr, unsigned level,
}
static void walk_pte(struct pg_state *st, pmd_t *pmdp, unsigned long start,
unsigned long end)
void ptdump_walk(struct seq_file *s, struct ptdump_info *info)
{
unsigned long addr = start;
pte_t *ptep = pte_offset_kernel(pmdp, start);
unsigned long end = ~0UL;
struct pg_state st;
do {
note_page(st, addr, 4, READ_ONCE(pte_val(*ptep)));
} while (ptep++, addr += PAGE_SIZE, addr != end);
}
if (info->base_addr < TASK_SIZE_64)
end = TASK_SIZE_64;
static void walk_pmd(struct pg_state *st, pud_t *pudp, unsigned long start,
unsigned long end)
{
unsigned long next, addr = start;
pmd_t *pmdp = pmd_offset(pudp, start);
do {
pmd_t pmd = READ_ONCE(*pmdp);
next = pmd_addr_end(addr, end);
if (pmd_none(pmd) || pmd_sect(pmd)) {
note_page(st, addr, 3, pmd_val(pmd));
} else {
BUG_ON(pmd_bad(pmd));
walk_pte(st, pmdp, addr, next);
}
} while (pmdp++, addr = next, addr != end);
}
static void walk_pud(struct pg_state *st, pgd_t *pgdp, unsigned long start,
unsigned long end)
{
unsigned long next, addr = start;
pud_t *pudp = pud_offset(pgdp, start);
do {
pud_t pud = READ_ONCE(*pudp);
next = pud_addr_end(addr, end);
if (pud_none(pud) || pud_sect(pud)) {
note_page(st, addr, 2, pud_val(pud));
} else {
BUG_ON(pud_bad(pud));
walk_pmd(st, pudp, addr, next);
}
} while (pudp++, addr = next, addr != end);
}
static void walk_pgd(struct pg_state *st, struct mm_struct *mm,
unsigned long start)
{
unsigned long end = (start < TASK_SIZE_64) ? TASK_SIZE_64 : 0;
unsigned long next, addr = start;
pgd_t *pgdp = pgd_offset(mm, start);
do {
pgd_t pgd = READ_ONCE(*pgdp);
next = pgd_addr_end(addr, end);
if (pgd_none(pgd)) {
note_page(st, addr, 1, pgd_val(pgd));
} else {
BUG_ON(pgd_bad(pgd));
walk_pud(st, pgdp, addr, next);
}
} while (pgdp++, addr = next, addr != end);
}
void ptdump_walk_pgd(struct seq_file *m, struct ptdump_info *info)
{
struct pg_state st = {
.seq = m,
st = (struct pg_state){
.seq = s,
.marker = info->markers,
.ptdump = {
.note_page = note_page,
.range = (struct ptdump_range[]){
{info->base_addr, end},
{0, 0}
}
}
};
walk_pgd(&st, info->mm, info->base_addr);
note_page(&st, 0, 0, 0);
ptdump_walk_pgd(&st.ptdump, info->mm);
}
static void ptdump_initialize(void)
@ -399,10 +351,17 @@ void ptdump_check_wx(void)
{ -1, NULL},
},
.check_wx = true,
.ptdump = {
.note_page = note_page,
.range = (struct ptdump_range[]) {
{PAGE_OFFSET, ~0UL},
{0, 0}
}
}
};
walk_pgd(&st, &init_mm, PAGE_OFFSET);
note_page(&st, 0, 0, 0);
ptdump_walk_pgd(&st.ptdump, &init_mm);
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);

4
arch/arm64/mm/mmu.c
View file

@ -943,13 +943,13 @@ int __init arch_ioremap_pud_supported(void)
* SW table walks can't handle removal of intermediate entries.
*/
return IS_ENABLED(CONFIG_ARM64_4K_PAGES) &&
!IS_ENABLED(CONFIG_ARM64_PTDUMP_DEBUGFS);
!IS_ENABLED(CONFIG_PTDUMP_DEBUGFS);
}
int __init arch_ioremap_pmd_supported(void)
{
/* See arch_ioremap_pud_supported() */
return !IS_ENABLED(CONFIG_ARM64_PTDUMP_DEBUGFS);
return !IS_ENABLED(CONFIG_PTDUMP_DEBUGFS);
}
int pud_set_huge(pud_t *pudp, phys_addr_t phys, pgprot_t prot)

2
arch/arm64/mm/ptdump_debugfs.c
View file

@ -7,7 +7,7 @@
static int ptdump_show(struct seq_file *m, void *v)
{
struct ptdump_info *info = m->private;
ptdump_walk_pgd(m, info);
ptdump_walk(m, info);
return 0;
}
DEFINE_SHOW_ATTRIBUTE(ptdump);

2
drivers/firmware/efi/arm-runtime.c
View file

@ -27,7 +27,7 @@
extern u64 efi_system_table;
#ifdef CONFIG_ARM64_PTDUMP_DEBUGFS
#if defined(CONFIG_PTDUMP_DEBUGFS) && defined(CONFIG_ARM64)
#include <asm/ptdump.h>
static struct ptdump_info efi_ptdump_info = {