v4.19.13 snapshot.
diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c
new file mode 100644
index 0000000..65dfc85
--- /dev/null
+++ b/arch/arm64/mm/dump.c
@@ -0,0 +1,413 @@
+/*
+ * 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>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ */
+#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/sched.h>
+#include <linux/seq_file.h>
+
+#include <asm/fixmap.h>
+#include <asm/kasan.h>
+#include <asm/memory.h>
+#include <asm/pgtable.h>
+#include <asm/pgtable-hwdef.h>
+#include <asm/ptdump.h>
+
+static const struct addr_marker address_markers[] = {
+#ifdef CONFIG_KASAN
+ { KASAN_SHADOW_START, "Kasan shadow start" },
+ { KASAN_SHADOW_END, "Kasan shadow end" },
+#endif
+ { 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" },
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+ { VMEMMAP_START, "vmemmap start" },
+ { VMEMMAP_START + VMEMMAP_SIZE, "vmemmap end" },
+#endif
+ { PAGE_OFFSET, "Linear Mapping" },
+ { -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 seq_file *seq;
+ const struct addr_marker *marker;
+ unsigned long start_address;
+ unsigned 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",
+ }, {
+ .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",
+ }
+};
+
+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),
+ }, { /* 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 pg_state *st, unsigned long addr, unsigned level,
+ u64 val)
+{
+ static const char units[] = "KMGTPE";
+ u64 prot = val & pg_level[level].mask;
+
+ if (!st->level) {
+ 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 (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);
+ }
+
+}
+
+static void walk_pte(struct pg_state *st, pmd_t *pmdp, unsigned long start)
+{
+ pte_t *ptep = pte_offset_kernel(pmdp, 0UL);
+ unsigned long addr;
+ unsigned i;
+
+ for (i = 0; i < PTRS_PER_PTE; i++, ptep++) {
+ addr = start + i * PAGE_SIZE;
+ note_page(st, addr, 4, READ_ONCE(pte_val(*ptep)));
+ }
+}
+
+static void walk_pmd(struct pg_state *st, pud_t *pudp, unsigned long start)
+{
+ pmd_t *pmdp = pmd_offset(pudp, 0UL);
+ unsigned long addr;
+ unsigned i;
+
+ for (i = 0; i < PTRS_PER_PMD; i++, pmdp++) {
+ pmd_t pmd = READ_ONCE(*pmdp);
+
+ addr = start + i * PMD_SIZE;
+ 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);
+ }
+ }
+}
+
+static void walk_pud(struct pg_state *st, pgd_t *pgdp, unsigned long start)
+{
+ pud_t *pudp = pud_offset(pgdp, 0UL);
+ unsigned long addr;
+ unsigned i;
+
+ for (i = 0; i < PTRS_PER_PUD; i++, pudp++) {
+ pud_t pud = READ_ONCE(*pudp);
+
+ addr = start + i * PUD_SIZE;
+ 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);
+ }
+ }
+}
+
+static void walk_pgd(struct pg_state *st, struct mm_struct *mm,
+ unsigned long start)
+{
+ pgd_t *pgdp = pgd_offset(mm, 0UL);
+ unsigned i;
+ unsigned long addr;
+
+ for (i = 0; i < PTRS_PER_PGD; i++, pgdp++) {
+ pgd_t pgd = READ_ONCE(*pgdp);
+
+ addr = start + i * PGDIR_SIZE;
+ if (pgd_none(pgd)) {
+ note_page(st, addr, 1, pgd_val(pgd));
+ } else {
+ BUG_ON(pgd_bad(pgd));
+ walk_pud(st, pgdp, addr);
+ }
+ }
+}
+
+void ptdump_walk_pgd(struct seq_file *m, struct ptdump_info *info)
+{
+ struct pg_state st = {
+ .seq = m,
+ .marker = info->markers,
+ };
+
+ walk_pgd(&st, info->mm, info->base_addr);
+
+ note_page(&st, 0, 0, 0);
+}
+
+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;
+}
+
+static struct ptdump_info kernel_ptdump_info = {
+ .mm = &init_mm,
+ .markers = address_markers,
+ .base_addr = VA_START,
+};
+
+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, VA_START);
+ note_page(&st, 0, 0, 0);
+ 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 ptdump_init(void)
+{
+ ptdump_initialize();
+ return ptdump_debugfs_register(&kernel_ptdump_info,
+ "kernel_page_tables");
+}
+device_initcall(ptdump_init);