Loading arch/arm64/Kconfig.debug +12 −0 Original line number Diff line number Diff line Loading @@ -20,6 +20,18 @@ config STRICT_DEVMEM If in doubt, say Y. config ARM64_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 bool "Early printk support" default y Loading arch/arm64/mm/Makefile +1 −0 Original line number Diff line number Diff line Loading @@ -3,3 +3,4 @@ obj-y := dma-mapping.o extable.o fault.o init.o \ ioremap.o iomap.o mmap.o pgd.o mmu.o \ context.o proc.o pageattr.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o obj-$(CONFIG_ARM64_PTDUMP) += dump.o arch/arm64/mm/dump.c 0 → 100644 +353 −0 Original line number Diff line number Diff line /* * 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); Loading
arch/arm64/Kconfig.debug +12 −0 Original line number Diff line number Diff line Loading @@ -20,6 +20,18 @@ config STRICT_DEVMEM If in doubt, say Y. config ARM64_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 bool "Early printk support" default y Loading
arch/arm64/mm/Makefile +1 −0 Original line number Diff line number Diff line Loading @@ -3,3 +3,4 @@ obj-y := dma-mapping.o extable.o fault.o init.o \ ioremap.o iomap.o mmap.o pgd.o mmu.o \ context.o proc.o pageattr.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o obj-$(CONFIG_ARM64_PTDUMP) += dump.o
arch/arm64/mm/dump.c 0 → 100644 +353 −0 Original line number Diff line number Diff line /* * 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);
