diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /arch/arm64/mm/ptdump.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm64/mm/ptdump.c')
-rw-r--r-- | arch/arm64/mm/ptdump.c | 386 |
1 files changed, 386 insertions, 0 deletions
diff --git a/arch/arm64/mm/ptdump.c b/arch/arm64/mm/ptdump.c new file mode 100644 index 0000000000..e305b6593c --- /dev/null +++ b/arch/arm64/mm/ptdump.c @@ -0,0 +1,386 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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> + */ +#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/ptdump.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-hwdef.h> +#include <asm/ptdump.h> + + +enum address_markers_idx { + PAGE_OFFSET_NR = 0, + PAGE_END_NR, +#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) + KASAN_START_NR, +#endif +}; + +static struct addr_marker address_markers[] = { + { PAGE_OFFSET, "Linear Mapping start" }, + { 0 /* PAGE_END */, "Linear Mapping end" }, +#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) + { 0 /* 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_TOT_START, "Fixmap start" }, + { FIXADDR_TOP, "Fixmap end" }, + { PCI_IO_START, "PCI I/O start" }, + { PCI_IO_END, "PCI I/O end" }, + { VMEMMAP_START, "vmemmap start" }, + { VMEMMAP_START + VMEMMAP_SIZE, "vmemmap end" }, + { -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 ptdump_state ptdump; + struct seq_file *seq; + const struct addr_marker *marker; + unsigned long start_address; + int 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", + .clear = " ", + }, { + .mask = PTE_GP, + .val = PTE_GP, + .set = "GP", + .clear = " ", + }, { + .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_NORMAL_NC), + .set = "MEM/NORMAL-NC", + }, { + .mask = PTE_ATTRINDX_MASK, + .val = PTE_ATTRINDX(MT_NORMAL), + .set = "MEM/NORMAL", + }, { + .mask = PTE_ATTRINDX_MASK, + .val = PTE_ATTRINDX(MT_NORMAL_TAGGED), + .set = "MEM/NORMAL-TAGGED", + } +}; + +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), + }, { /* p4d */ + .name = "P4D", + .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 ptdump_state *pt_st, unsigned long addr, int level, + u64 val) +{ + struct pg_state *st = container_of(pt_st, struct pg_state, ptdump); + static const char units[] = "KMGTPE"; + u64 prot = 0; + + if (level >= 0) + prot = val & pg_level[level].mask; + + if (st->level == -1) { + 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 (st->current_prot && 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); + } + +} + +void ptdump_walk(struct seq_file *s, struct ptdump_info *info) +{ + unsigned long end = ~0UL; + struct pg_state st; + + if (info->base_addr < TASK_SIZE_64) + end = TASK_SIZE_64; + + st = (struct pg_state){ + .seq = s, + .marker = info->markers, + .level = -1, + .ptdump = { + .note_page = note_page, + .range = (struct ptdump_range[]){ + {info->base_addr, end}, + {0, 0} + } + } + }; + + ptdump_walk_pgd(&st.ptdump, info->mm, NULL); +} + +static void __init 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 = PAGE_OFFSET, +}; + +void ptdump_check_wx(void) +{ + struct pg_state st = { + .seq = NULL, + .marker = (struct addr_marker[]) { + { 0, NULL}, + { -1, NULL}, + }, + .level = -1, + .check_wx = true, + .ptdump = { + .note_page = note_page, + .range = (struct ptdump_range[]) { + {PAGE_OFFSET, ~0UL}, + {0, 0} + } + } + }; + + ptdump_walk_pgd(&st.ptdump, &init_mm, NULL); + + 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 __init ptdump_init(void) +{ + address_markers[PAGE_END_NR].start_address = PAGE_END; +#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) + address_markers[KASAN_START_NR].start_address = KASAN_SHADOW_START; +#endif + ptdump_initialize(); + ptdump_debugfs_register(&kernel_ptdump_info, "kernel_page_tables"); + return 0; +} +device_initcall(ptdump_init); |