| /* |
| * 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/fs.h> |
| #include <linux/mm.h> |
| #include <linux/seq_file.h> |
| |
| #include <asm/pgtable.h> |
| |
| #define LOWEST_ADDR (UL(0xffffffffffffffff) << VA_BITS) |
| |
| struct addr_marker { |
| unsigned long start_address; |
| const char *name; |
| }; |
| |
| static struct addr_marker address_markers[] = { |
| { 0, "vmalloc() Area" }, |
| { VMALLOC_END, "vmalloc() End" }, |
| { MODULES_VADDR, "Modules" }, |
| { PAGE_OFFSET, "Kernel Mapping" }, |
| { -1, NULL }, |
| }; |
| |
| struct pg_state { |
| struct seq_file *seq; |
| const struct addr_marker *marker; |
| unsigned long start_address; |
| unsigned level; |
| u64 current_prot; |
| }; |
| |
| struct prot_bits { |
| u64 mask; |
| u64 val; |
| const char *set; |
| const char *clear; |
| }; |
| |
| static const struct prot_bits pte_bits[] = { |
| { |
| .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_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/BUFFERABLE", |
| }, { |
| .mask = PTE_ATTRINDX_MASK, |
| .val = PTE_ATTRINDX(MT_NORMAL), |
| .set = "MEM/NORMAL", |
| } |
| }; |
| |
| static const struct prot_bits section_bits[] = { |
| { |
| .mask = PMD_SECT_USER, |
| .val = PMD_SECT_USER, |
| .set = "USR", |
| }, { |
| .mask = PMD_SECT_RDONLY, |
| .val = PMD_SECT_RDONLY, |
| .set = "ro", |
| .clear = "RW", |
| }, { |
| .mask = PMD_SECT_PXN, |
| .val = PMD_SECT_PXN, |
| .set = "NX", |
| .clear = "x ", |
| }, { |
| .mask = PMD_SECT_S, |
| .val = PMD_SECT_S, |
| .set = "SHD", |
| .clear = " ", |
| }, { |
| .mask = PMD_SECT_AF, |
| .val = PMD_SECT_AF, |
| .set = "AF", |
| .clear = " ", |
| }, { |
| .mask = PMD_SECT_NG, |
| .val = PMD_SECT_NG, |
| .set = "NG", |
| .clear = " ", |
| }, { |
| .mask = PMD_SECT_UXN, |
| .val = PMD_SECT_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/BUFFERABLE", |
| }, { |
| .mask = PTE_ATTRINDX_MASK, |
| .val = PTE_ATTRINDX(MT_NORMAL), |
| .set = "MEM/NORMAL", |
| } |
| }; |
| |
| struct pg_level { |
| const struct prot_bits *bits; |
| size_t num; |
| u64 mask; |
| }; |
| |
| static struct pg_level pg_level[] = { |
| { |
| }, { /* pgd */ |
| }, { /* pud */ |
| }, { /* pmd */ |
| .bits = section_bits, |
| .num = ARRAY_SIZE(section_bits), |
| }, { /* 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) |
| seq_printf(st->seq, " %s", s); |
| } |
| } |
| |
| 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 (addr < LOWEST_ADDR) |
| return; |
| |
| if (!st->level) { |
| st->level = level; |
| st->current_prot = prot; |
| st->start_address = addr; |
| 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) { |
| seq_printf(st->seq, "0x%16lx-0x%16lx ", |
| st->start_address, addr); |
| |
| delta = (addr - st->start_address) >> 10; |
| while (!(delta & 1023) && unit[1]) { |
| delta >>= 10; |
| unit++; |
| } |
| seq_printf(st->seq, "%9lu%c", delta, *unit); |
| if (pg_level[st->level].bits) |
| dump_prot(st, pg_level[st->level].bits, |
| pg_level[st->level].num); |
| seq_puts(st->seq, "\n"); |
| } |
| |
| if (addr >= st->marker[1].start_address) { |
| st->marker++; |
| seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); |
| } |
| st->start_address = addr; |
| st->current_prot = prot; |
| st->level = level; |
| } |
| } |
| |
| static void walk_pte(struct pg_state *st, pmd_t *pmd, unsigned long start) |
| { |
| pte_t *pte = pte_offset_kernel(pmd, 0); |
| unsigned long addr; |
| unsigned i; |
| |
| for (i = 0; i < PTRS_PER_PTE; i++, pte++) { |
| addr = start + i * PAGE_SIZE; |
| note_page(st, addr, 4, pte_val(*pte)); |
| } |
| } |
| |
| static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start) |
| { |
| pmd_t *pmd = pmd_offset(pud, 0); |
| unsigned long addr; |
| unsigned i; |
| |
| for (i = 0; i < PTRS_PER_PMD; i++, pmd++) { |
| addr = start + i * PMD_SIZE; |
| if (pmd_none(*pmd) || !pmd_present(*pmd) || pmd_bad(*pmd)) |
| note_page(st, addr, 3, pmd_val(*pmd)); |
| else |
| walk_pte(st, pmd, addr); |
| } |
| } |
| |
| static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start) |
| { |
| pud_t *pud = pud_offset(pgd, 0); |
| unsigned long addr; |
| unsigned i; |
| |
| for (i = 0; i < PTRS_PER_PUD; i++, pud++) { |
| addr = start + i * PUD_SIZE; |
| if (!pud_none(*pud)) |
| walk_pmd(st, pud, addr); |
| else |
| note_page(st, addr, 2, pud_val(*pud)); |
| } |
| } |
| |
| static unsigned long normalize_addr(unsigned long u) |
| { |
| return u | LOWEST_ADDR; |
| } |
| |
| static void walk_pgd(struct seq_file *m) |
| { |
| pgd_t *pgd = swapper_pg_dir; |
| struct pg_state st; |
| unsigned long addr; |
| unsigned i, pgdoff = 0; |
| |
| memset(&st, 0, sizeof(st)); |
| st.seq = m; |
| st.marker = address_markers; |
| |
| for (i = pgdoff; i < PTRS_PER_PGD; i++, pgd++) { |
| addr = normalize_addr(i * PGDIR_SIZE); |
| if (!pgd_none(*pgd)) |
| walk_pud(&st, pgd, addr); |
| else |
| note_page(&st, addr, 1, pgd_val(*pgd)); |
| } |
| |
| note_page(&st, 0, 0, 0); |
| } |
| |
| static int ptdump_show(struct seq_file *m, void *v) |
| { |
| walk_pgd(m); |
| return 0; |
| } |
| |
| static int ptdump_open(struct inode *inode, struct file *file) |
| { |
| return single_open(file, ptdump_show, NULL); |
| } |
| |
| static const struct file_operations ptdump_fops = { |
| .open = ptdump_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = single_release, |
| }; |
| |
| static int ptdump_init(void) |
| { |
| struct dentry *pe; |
| 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; |
| |
| address_markers[0].start_address = VMALLOC_START; |
| |
| pe = debugfs_create_file("kernel_page_tables", 0400, NULL, NULL, |
| &ptdump_fops); |
| return pe ? 0 : -ENOMEM; |
| } |
| device_initcall(ptdump_init); |