arm64/mm/ptdump: Add address markers for BPF regions

Kernel virtual region [BPF_JIT_REGION_START..BPF_JIT_REGION_END] is missing
from address_markers[], hence relevant page table entries are not displayed
with /sys/kernel/debug/kernel_page_tables. This adds those missing markers.
While here, also rename arch/arm64/mm/dump.c which sounds bit ambiguous, as
arch/arm64/mm/ptdump.c instead.

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/1599208259-11191-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 0 insertions, 387 deletions

diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c
deleted file mode 100644
index 0b8da1cc1c07..000000000000
--- a/arch/arm64/mm/dump.c
+++ /dev/null
@@ -1,387 +0,0 @@
-// 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,
-#ifdef CONFIG_KASAN
-	KASAN_START_NR,
-#endif
-};
-
-static struct addr_marker address_markers[] = {
-	{ PAGE_OFFSET,			"Linear Mapping start" },
-	{ 0 /* PAGE_END */,		"Linear Mapping end" },
-#ifdef CONFIG_KASAN
-	{ 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_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
-	{ -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_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),
-	}, { /* 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,
-		.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 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 ptdump_init(void)
-{
-	address_markers[PAGE_END_NR].start_address = PAGE_END;
-#ifdef CONFIG_KASAN
-	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);