From 9d719d39aab41d3b8b6f259574dc29a27f60e66c Mon Sep 17 00:00:00 2001
From: Heiko Carstens <hca@linux.ibm.com>
Date: Fri, 4 Sep 2020 17:41:27 +0200
Subject: [PATCH] s390/mm,ptdump: convert to generic page table dumper
Make use of generic ptdump infrastructure.
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
---
arch/s390/Kconfig | 1 +
arch/s390/Kconfig.debug | 12 --
arch/s390/configs/debug_defconfig | 2 +-
arch/s390/configs/defconfig | 2 +-
arch/s390/mm/Makefile | 2 +-
arch/s390/mm/dump_pagetables.c | 233 ++++++------------------------
6 files changed, 51 insertions(+), 201 deletions(-)
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 8a6121f937092..85bf121211d10 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -120,6 +120,7 @@ config S390
select GENERIC_CPU_VULNERABILITIES
select GENERIC_FIND_FIRST_BIT
select GENERIC_GETTIMEOFDAY
+ select GENERIC_PTDUMP
select GENERIC_SMP_IDLE_THREAD
select GENERIC_TIME_VSYSCALL
select HAVE_ALIGNED_STRUCT_PAGE if SLUB
diff --git a/arch/s390/Kconfig.debug b/arch/s390/Kconfig.debug
index 761fe2b0b2f6d..ab48b694ade8e 100644
--- a/arch/s390/Kconfig.debug
+++ b/arch/s390/Kconfig.debug
@@ -3,17 +3,5 @@
config TRACE_IRQFLAGS_SUPPORT
def_bool y
-config S390_PTDUMP
- bool "Export kernel pagetable layout to userspace via debugfs"
- depends on DEBUG_KERNEL
- 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 EARLY_PRINTK
def_bool y
diff --git a/arch/s390/configs/debug_defconfig b/arch/s390/configs/debug_defconfig
index 0cf9a82326a85..f79eafb597cb3 100644
--- a/arch/s390/configs/debug_defconfig
+++ b/arch/s390/configs/debug_defconfig
@@ -774,6 +774,7 @@ CONFIG_MAGIC_SYSRQ=y
CONFIG_DEBUG_PAGEALLOC=y
CONFIG_PAGE_OWNER=y
CONFIG_DEBUG_RODATA_TEST=y
+CONFIG_PTDUMP_DEBUGFS=y
CONFIG_DEBUG_OBJECTS=y
CONFIG_DEBUG_OBJECTS_SELFTEST=y
CONFIG_DEBUG_OBJECTS_FREE=y
@@ -819,7 +820,6 @@ CONFIG_SCHED_TRACER=y
CONFIG_FTRACE_SYSCALLS=y
CONFIG_BLK_DEV_IO_TRACE=y
CONFIG_HIST_TRIGGERS=y
-CONFIG_S390_PTDUMP=y
CONFIG_NOTIFIER_ERROR_INJECTION=m
CONFIG_NETDEV_NOTIFIER_ERROR_INJECT=m
CONFIG_FAULT_INJECTION=y
diff --git a/arch/s390/configs/defconfig b/arch/s390/configs/defconfig
index 5df9759e8ff67..9593cc8a9efd6 100644
--- a/arch/s390/configs/defconfig
+++ b/arch/s390/configs/defconfig
@@ -758,6 +758,7 @@ CONFIG_GDB_SCRIPTS=y
CONFIG_FRAME_WARN=1024
CONFIG_DEBUG_SECTION_MISMATCH=y
CONFIG_MAGIC_SYSRQ=y
+CONFIG_PTDUMP_DEBUGFS=y
CONFIG_DEBUG_MEMORY_INIT=y
CONFIG_PANIC_ON_OOPS=y
CONFIG_TEST_LOCKUP=m
@@ -772,7 +773,6 @@ CONFIG_SCHED_TRACER=y
CONFIG_FTRACE_SYSCALLS=y
CONFIG_BLK_DEV_IO_TRACE=y
CONFIG_HIST_TRIGGERS=y
-CONFIG_S390_PTDUMP=y
CONFIG_LKDTM=m
CONFIG_PERCPU_TEST=m
CONFIG_ATOMIC64_SELFTEST=y
diff --git a/arch/s390/mm/Makefile b/arch/s390/mm/Makefile
index 3175413186b9d..8ab9daeeace38 100644
--- a/arch/s390/mm/Makefile
+++ b/arch/s390/mm/Makefile
@@ -8,7 +8,7 @@ obj-y += page-states.o pageattr.o pgtable.o pgalloc.o
obj-$(CONFIG_CMM) += cmm.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
-obj-$(CONFIG_S390_PTDUMP) += dump_pagetables.o
+obj-$(CONFIG_PTDUMP_DEBUGFS) += dump_pagetables.o
obj-$(CONFIG_PGSTE) += gmap.o
KASAN_SANITIZE_kasan_init.o := n
diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c
index c2ac9b8ae6120..93a29e2f13d42 100644
--- a/arch/s390/mm/dump_pagetables.c
+++ b/arch/s390/mm/dump_pagetables.c
@@ -1,7 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
+#include <linux/ptdump.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
-#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/kasan.h>
#include <asm/kasan.h>
@@ -42,10 +42,11 @@ static struct addr_marker address_markers[] = {
};
struct pg_state {
+ struct ptdump_state ptdump;
+ struct seq_file *seq;
int level;
unsigned int current_prot;
unsigned long start_address;
- unsigned long current_address;
const struct addr_marker *marker;
};
@@ -63,215 +64,75 @@ static void print_prot(struct seq_file *m, unsigned int pr, int level)
seq_puts(m, (pr & _PAGE_NOEXEC) ? "NX\n" : "X\n");
}
-static void note_page(struct seq_file *m, struct pg_state *st,
- unsigned int new_prot, int level)
+static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level, u64 val)
{
- static const char units[] = "KMGTPE";
int width = sizeof(unsigned long) * 2;
+ static const char units[] = "KMGTPE";
const char *unit = units;
- unsigned int prot, cur;
unsigned long delta;
+ struct pg_state *st;
+ struct seq_file *m;
+ unsigned int prot;
- /*
- * 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;
+ st = container_of(pt_st, struct pg_state, ptdump);
+ m = st->seq;
+ prot = val & (_PAGE_PROTECT | _PAGE_NOEXEC);
+ if (level == 4 && (val & _PAGE_INVALID))
+ prot = _PAGE_INVALID;
+ /* For pmd_none() & friends val gets passed as zero. */
+ if (level != 4 && !val)
+ prot = _PAGE_INVALID;
+ /* Final flush from generic code. */
+ if (level == -1)
+ addr = max_addr;
+ if (st->level == -1) {
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 */
+ st->start_address = addr;
+ st->current_prot = prot;
+ st->level = level;
+ } else if (prot != st->current_prot || level != st->level ||
+ addr >= st->marker[1].start_address) {
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;
+ width, addr);
+ delta = (addr - 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);
- while (st->current_address >= st->marker[1].start_address) {
+ while (addr >= 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->start_address = addr;
+ st->current_prot = prot;
st->level = level;
}
}
-#ifdef CONFIG_KASAN
-static void note_kasan_early_shadow_page(struct seq_file *m,
- struct pg_state *st)
-{
- unsigned int prot;
-
- prot = pte_val(*kasan_early_shadow_pte) &
- (_PAGE_PROTECT | _PAGE_INVALID | _PAGE_NOEXEC);
- note_page(m, st, prot, 4);
-}
-#endif
-
-/*
- * 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 | _PAGE_NOEXEC);
- 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;
-
-#ifdef CONFIG_KASAN
- if ((pud_val(*pud) & PAGE_MASK) == __pa(kasan_early_shadow_pmd)) {
- note_kasan_early_shadow_page(m, st);
- return;
- }
-#endif
-
- pmd = pmd_offset(pud, addr);
- for (i = 0; i < PTRS_PER_PMD && addr < max_addr; i++, pmd++) {
- st->current_address = addr;
- if (!pmd_none(*pmd)) {
- if (pmd_large(*pmd)) {
- prot = pmd_val(*pmd) &
- (_SEGMENT_ENTRY_PROTECT |
- _SEGMENT_ENTRY_NOEXEC);
- 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,
- p4d_t *p4d, unsigned long addr)
-{
- unsigned int prot;
- pud_t *pud;
- int i;
-
-#ifdef CONFIG_KASAN
- if ((p4d_val(*p4d) & PAGE_MASK) == __pa(kasan_early_shadow_pud)) {
- note_kasan_early_shadow_page(m, st);
- return;
- }
-#endif
-
- pud = pud_offset(p4d, addr);
- for (i = 0; i < PTRS_PER_PUD && addr < max_addr; i++, pud++) {
- st->current_address = addr;
- if (!pud_none(*pud))
- if (pud_large(*pud)) {
- prot = pud_val(*pud) &
- (_REGION_ENTRY_PROTECT |
- _REGION_ENTRY_NOEXEC);
- 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_p4d_level(struct seq_file *m, struct pg_state *st,
- pgd_t *pgd, unsigned long addr)
-{
- p4d_t *p4d;
- int i;
-
-#ifdef CONFIG_KASAN
- if ((pgd_val(*pgd) & PAGE_MASK) == __pa(kasan_early_shadow_p4d)) {
- note_kasan_early_shadow_page(m, st);
- return;
- }
-#endif
-
- p4d = p4d_offset(pgd, addr);
- for (i = 0; i < PTRS_PER_P4D && addr < max_addr; i++, p4d++) {
- st->current_address = addr;
- if (!p4d_none(*p4d))
- walk_pud_level(m, st, p4d, addr);
- else
- note_page(m, st, _PAGE_INVALID, 2);
- addr += P4D_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_p4d_level(m, &st, pgd, addr);
- else
- note_page(m, &st, _PAGE_INVALID, 1);
- addr += PGDIR_SIZE;
- cond_resched();
- }
- /* 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);
+ struct pg_state st = {
+ .ptdump = {
+ .note_page = note_page,
+ .range = (struct ptdump_range[]) {
+ {.start = 0, .end = max_addr},
+ {.start = 0, .end = 0},
+ }
+ },
+ .seq = m,
+ .level = -1,
+ .current_prot = 0,
+ .start_address = 0,
+ .marker = address_markers,
+ };
+
+ ptdump_walk_pgd(&st.ptdump, &init_mm, NULL);
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,
-};
+DEFINE_SHOW_ATTRIBUTE(ptdump);
static int pt_dump_init(void)
{
--
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