From 01573e231f18eb2d99162747186f59511f56b64d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 08 Dec 2023 10:40:48 +0000
Subject: [PATCH] 移去rt
---
kernel/arch/s390/mm/dump_pagetables.c | 346 ++++++++++++++++++++++++++++++---------------------------
1 files changed, 184 insertions(+), 162 deletions(-)
diff --git a/kernel/arch/s390/mm/dump_pagetables.c b/kernel/arch/s390/mm/dump_pagetables.c
index 7cdea2e..8f9ff7e 100644
--- a/kernel/arch/s390/mm/dump_pagetables.c
+++ b/kernel/arch/s390/mm/dump_pagetables.c
@@ -1,10 +1,13 @@
// SPDX-License-Identifier: GPL-2.0
+#include <linux/set_memory.h>
+#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/ptdump.h>
+#include <asm/kasan.h>
#include <asm/sections.h>
-#include <asm/pgtable.h>
static unsigned long max_addr;
@@ -14,222 +17,234 @@
};
enum address_markers_idx {
- IDENTITY_NR = 0,
+ IDENTITY_BEFORE_NR = 0,
+ IDENTITY_BEFORE_END_NR,
KERNEL_START_NR,
KERNEL_END_NR,
+ IDENTITY_AFTER_NR,
+ IDENTITY_AFTER_END_NR,
+#ifdef CONFIG_KASAN
+ KASAN_SHADOW_START_NR,
+ KASAN_SHADOW_END_NR,
+#endif
VMEMMAP_NR,
+ VMEMMAP_END_NR,
VMALLOC_NR,
+ VMALLOC_END_NR,
MODULES_NR,
+ MODULES_END_NR,
};
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"},
- [MODULES_NR] = {0, "Modules Area"},
+ [IDENTITY_BEFORE_NR] = {0, "Identity Mapping Start"},
+ [IDENTITY_BEFORE_END_NR] = {(unsigned long)_stext, "Identity Mapping End"},
+ [KERNEL_START_NR] = {(unsigned long)_stext, "Kernel Image Start"},
+ [KERNEL_END_NR] = {(unsigned long)_end, "Kernel Image End"},
+ [IDENTITY_AFTER_NR] = {(unsigned long)_end, "Identity Mapping Start"},
+ [IDENTITY_AFTER_END_NR] = {0, "Identity Mapping End"},
+#ifdef CONFIG_KASAN
+ [KASAN_SHADOW_START_NR] = {KASAN_SHADOW_START, "Kasan Shadow Start"},
+ [KASAN_SHADOW_END_NR] = {KASAN_SHADOW_END, "Kasan Shadow End"},
+#endif
+ [VMEMMAP_NR] = {0, "vmemmap Area Start"},
+ [VMEMMAP_END_NR] = {0, "vmemmap Area End"},
+ [VMALLOC_NR] = {0, "vmalloc Area Start"},
+ [VMALLOC_END_NR] = {0, "vmalloc Area End"},
+ [MODULES_NR] = {0, "Modules Area Start"},
+ [MODULES_END_NR] = {0, "Modules Area End"},
{ -1, NULL }
};
struct pg_state {
+ struct ptdump_state ptdump;
+ struct seq_file *seq;
int level;
unsigned int current_prot;
+ bool check_wx;
+ unsigned long wx_pages;
unsigned long start_address;
- unsigned long current_address;
const struct addr_marker *marker;
};
+
+#define pt_dump_seq_printf(m, fmt, args...) \
+({ \
+ struct seq_file *__m = (m); \
+ \
+ if (__m) \
+ seq_printf(__m, fmt, ##args); \
+})
+
+#define pt_dump_seq_puts(m, fmt) \
+({ \
+ struct seq_file *__m = (m); \
+ \
+ if (__m) \
+ seq_printf(__m, fmt); \
+})
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]);
+ pt_dump_seq_printf(m, "%s ", level_name[level]);
if (pr & _PAGE_INVALID) {
- seq_printf(m, "I\n");
+ pt_dump_seq_printf(m, "I\n");
return;
}
- seq_puts(m, (pr & _PAGE_PROTECT) ? "RO " : "RW ");
- seq_puts(m, (pr & _PAGE_NOEXEC) ? "NX\n" : "X\n");
+ pt_dump_seq_puts(m, (pr & _PAGE_PROTECT) ? "RO " : "RW ");
+ pt_dump_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_prot_wx(struct pg_state *st, unsigned long addr)
{
- static const char units[] = "KMGTPE";
+#ifdef CONFIG_DEBUG_WX
+ if (!st->check_wx)
+ return;
+ if (st->current_prot & _PAGE_INVALID)
+ return;
+ if (st->current_prot & _PAGE_PROTECT)
+ return;
+ if (st->current_prot & _PAGE_NOEXEC)
+ return;
+ /* The first lowcore page is currently still W+X. */
+ if (addr == PAGE_SIZE)
+ return;
+ WARN_ONCE(1, "s390/mm: Found insecure W+X mapping at address %pS\n",
+ (void *)st->start_address);
+ st->wx_pages += (addr - st->start_address) / PAGE_SIZE;
+#endif /* CONFIG_DEBUG_WX */
+}
+
+static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level, u64 val)
+{
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 = 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) {
+ pt_dump_seq_printf(m, "---[ %s ]---\n", st->marker->name);
+ st->start_address = addr;
+ st->current_prot = 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;
+ } else if (prot != st->current_prot || level != st->level ||
+ addr >= st->marker[1].start_address) {
+ note_prot_wx(st, addr);
+ pt_dump_seq_printf(m, "0x%0*lx-0x%0*lx ",
+ width, st->start_address,
+ width, addr);
+ delta = (addr - st->start_address) >> 10;
while (!(delta & 0x3ff) && unit[1]) {
delta >>= 10;
unit++;
}
- seq_printf(m, "%9lu%c ", delta, *unit);
+ pt_dump_seq_printf(m, "%9lu%c ", delta, *unit);
print_prot(m, st->current_prot, st->level);
- if (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);
+ pt_dump_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;
}
}
-/*
- * 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)
+#ifdef CONFIG_DEBUG_WX
+void ptdump_check_wx(void)
{
- unsigned int prot;
- pte_t *pte;
- int i;
+ struct pg_state st = {
+ .ptdump = {
+ .note_page = note_page,
+ .range = (struct ptdump_range[]) {
+ {.start = 0, .end = max_addr},
+ {.start = 0, .end = 0},
+ }
+ },
+ .seq = NULL,
+ .level = -1,
+ .current_prot = 0,
+ .check_wx = true,
+ .wx_pages = 0,
+ .start_address = 0,
+ .marker = (struct addr_marker[]) {
+ { .start_address = 0, .name = NULL},
+ { .start_address = -1, .name = NULL},
+ },
+ };
- 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;
- }
+ if (!MACHINE_HAS_NX)
+ return;
+ ptdump_walk_pgd(&st.ptdump, &init_mm, 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 unexpected W+X pages found\n");
}
+#endif /* CONFIG_DEBUG_WX */
-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) &
- (_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;
-
- for (i = 0; i < PTRS_PER_PUD && addr < max_addr; i++) {
- st->current_address = addr;
- pud = pud_offset(p4d, 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;
-
- for (i = 0; i < PTRS_PER_P4D && addr < max_addr; i++) {
- st->current_address = addr;
- p4d = p4d_offset(pgd, 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);
-}
-
+#ifdef CONFIG_PTDUMP_DEBUGFS
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,
+ .check_wx = false,
+ .wx_pages = 0,
+ .start_address = 0,
+ .marker = address_markers,
+ };
+
+ get_online_mems();
+ mutex_lock(&cpa_mutex);
+ ptdump_walk_pgd(&st.ptdump, &init_mm, NULL);
+ mutex_unlock(&cpa_mutex);
+ put_online_mems();
return 0;
}
+DEFINE_SHOW_ATTRIBUTE(ptdump);
+#endif /* CONFIG_PTDUMP_DEBUGFS */
-static int ptdump_open(struct inode *inode, struct file *filp)
+/*
+ * Heapsort from lib/sort.c is not a stable sorting algorithm, do a simple
+ * insertion sort to preserve the original order of markers with the same
+ * start address.
+ */
+static void sort_address_markers(void)
{
- return single_open(filp, ptdump_show, NULL);
-}
+ struct addr_marker tmp;
+ int i, j;
-static const struct file_operations ptdump_fops = {
- .open = ptdump_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
-};
+ for (i = 1; i < ARRAY_SIZE(address_markers) - 1; i++) {
+ tmp = address_markers[i];
+ for (j = i - 1; j >= 0 && address_markers[j].start_address > tmp.start_address; j--)
+ address_markers[j + 1] = address_markers[j];
+ address_markers[j + 1] = tmp;
+ }
+}
static int pt_dump_init(void)
{
@@ -240,10 +255,17 @@
*/
max_addr = (S390_lowcore.kernel_asce & _REGION_ENTRY_TYPE_MASK) >> 2;
max_addr = 1UL << (max_addr * 11 + 31);
+ address_markers[IDENTITY_AFTER_END_NR].start_address = memory_end;
address_markers[MODULES_NR].start_address = MODULES_VADDR;
+ address_markers[MODULES_END_NR].start_address = MODULES_END;
address_markers[VMEMMAP_NR].start_address = (unsigned long) vmemmap;
+ address_markers[VMEMMAP_END_NR].start_address = (unsigned long)vmemmap + vmemmap_size;
address_markers[VMALLOC_NR].start_address = VMALLOC_START;
+ address_markers[VMALLOC_END_NR].start_address = VMALLOC_END;
+ sort_address_markers();
+#ifdef CONFIG_PTDUMP_DEBUGFS
debugfs_create_file("kernel_page_tables", 0400, NULL, NULL, &ptdump_fops);
+#endif /* CONFIG_PTDUMP_DEBUGFS */
return 0;
}
device_initcall(pt_dump_init);
--
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