arm64: mm: convert mm/dump.c to use walk_page_range() (102f45fd) · Commits · 戴 / test

arch/arm64/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -104,6 +104,7 @@ config ARM64
		select GENERIC_IRQ_SHOW
		select GENERIC_IRQ_SHOW_LEVEL
		select GENERIC_PCI_IOMAP
		select GENERIC_PTDUMP
		select GENERIC_SCHED_CLOCK
		select GENERIC_SMP_IDLE_THREAD
		select GENERIC_STRNCPY_FROM_USER

arch/arm64/Kconfig.debug

+1 −18

Original line number	Diff line number	Diff line
		# SPDX-License-Identifier: GPL-2.0-only

		config ARM64_PTDUMP_CORE
		def_bool n

		config ARM64_PTDUMP_DEBUGFS
		bool "Export kernel pagetable layout to userspace via debugfs"
		depends on DEBUG_KERNEL
		select ARM64_PTDUMP_CORE
		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 PID_IN_CONTEXTIDR
		bool "Write the current PID to the CONTEXTIDR register"
		help
		@@ -42,7 +25,7 @@ config ARM64_RANDOMIZE_TEXT_OFFSET

		config DEBUG_WX
		bool "Warn on W+X mappings at boot"
		select ARM64_PTDUMP_CORE
		select PTDUMP_CORE
		---help---
		Generate a warning if any W+X mappings are found at boot.

arch/arm64/include/asm/ptdump.h

+4 −4

Original line number	Diff line number	Diff line
		@@ -5,7 +5,7 @@
		#ifndef __ASM_PTDUMP_H
		#define __ASM_PTDUMP_H

		#ifdef CONFIG_ARM64_PTDUMP_CORE
		#ifdef CONFIG_PTDUMP_CORE

		#include <linux/mm_types.h>
		#include <linux/seq_file.h>
		@@ -21,15 +21,15 @@ struct ptdump_info {
		unsigned long base_addr;
		};

		void ptdump_walk_pgd(struct seq_file s, struct ptdump_info info);
		#ifdef CONFIG_ARM64_PTDUMP_DEBUGFS
		void ptdump_walk(struct seq_file s, struct ptdump_info info);
		#ifdef CONFIG_PTDUMP_DEBUGFS
		void ptdump_debugfs_register(struct ptdump_info info, const char name);
		#else
		static inline void ptdump_debugfs_register(struct ptdump_info *info,
		const char *name) { }
		#endif
		void ptdump_check_wx(void);
		#endif /* CONFIG_ARM64_PTDUMP_CORE */
		#endif /* CONFIG_PTDUMP_CORE */

		#ifdef CONFIG_DEBUG_WX
		#define debug_checkwx() ptdump_check_wx()

arch/arm64/mm/Makefile

+2 −2

Original line number	Diff line number	Diff line
		@@ -4,8 +4,8 @@ obj-y := dma-mapping.o extable.o fault.o init.o \
		ioremap.o mmap.o pgd.o mmu.o \
		context.o proc.o pageattr.o
		obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
		obj-$(CONFIG_ARM64_PTDUMP_CORE) += dump.o
		obj-$(CONFIG_ARM64_PTDUMP_DEBUGFS) += ptdump_debugfs.o
		obj-$(CONFIG_PTDUMP_CORE) += dump.o
		obj-$(CONFIG_PTDUMP_DEBUGFS) += ptdump_debugfs.o
		obj-$(CONFIG_NUMA) += numa.o
		obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o
		KASAN_SANITIZE_physaddr.o += n

arch/arm64/mm/dump.c

+38 −79

Original line number	Diff line number	Diff line
		@@ -15,6 +15,7 @@
		#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>

		@@ -75,10 +76,11 @@ static struct addr_marker address_markers[] = {
		* 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;
		unsigned level;
		int level;
		u64 current_prot;
		bool check_wx;
		unsigned long wx_pages;
		@@ -179,6 +181,10 @@ static struct pg_level pg_level[] = {
		.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,
		@@ -241,11 +247,15 @@ static void note_prot_wx(struct pg_state *st, unsigned long addr)
		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 void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
		unsigned long val)
		{
		struct pg_state *st = container_of(pt_st, struct pg_state, ptdump);
		static const char units[] = "KMGTPE";
		u64 prot = val & pg_level[level].mask;
		u64 prot = 0;

		if (level >= 0)
		prot = val & pg_level[level].mask;

		if (!st->level) {
		st->level = level;
		@@ -293,85 +303,27 @@ static void note_page(struct pg_state *st, unsigned long addr, unsigned level,

		}

		static void walk_pte(struct pg_state st, pmd_t pmdp, unsigned long start,
		unsigned long end)
		void ptdump_walk(struct seq_file s, struct ptdump_info info)
		{
		unsigned long addr = start;
		pte_t *ptep = pte_offset_kernel(pmdp, start);
		unsigned long end = ~0UL;
		struct pg_state st;

		do {
		note_page(st, addr, 4, READ_ONCE(pte_val(*ptep)));
		} while (ptep++, addr += PAGE_SIZE, addr != end);
		}

		static void walk_pmd(struct pg_state st, pud_t pudp, unsigned long start,
		unsigned long end)
		{
		unsigned long next, addr = start;
		pmd_t *pmdp = pmd_offset(pudp, start);

		do {
		pmd_t pmd = READ_ONCE(*pmdp);
		next = pmd_addr_end(addr, end);

		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, next);
		}
		} while (pmdp++, addr = next, addr != end);
		}

		static void walk_pud(struct pg_state st, pgd_t pgdp, unsigned long start,
		unsigned long end)
		{
		unsigned long next, addr = start;
		pud_t *pudp = pud_offset(pgdp, start);

		do {
		pud_t pud = READ_ONCE(*pudp);
		next = pud_addr_end(addr, end);

		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, next);
		}
		} while (pudp++, addr = next, addr != end);
		}
		if (info->base_addr < TASK_SIZE_64)
		end = TASK_SIZE_64;

		static void walk_pgd(struct pg_state st, struct mm_struct mm,
		unsigned long start)
		{
		unsigned long end = (start < TASK_SIZE_64) ? TASK_SIZE_64 : 0;
		unsigned long next, addr = start;
		pgd_t *pgdp = pgd_offset(mm, start);

		do {
		pgd_t pgd = READ_ONCE(*pgdp);
		next = pgd_addr_end(addr, end);

		if (pgd_none(pgd)) {
		note_page(st, addr, 1, pgd_val(pgd));
		} else {
		BUG_ON(pgd_bad(pgd));
		walk_pud(st, pgdp, addr, next);
		st = (struct pg_state){
		.seq = s,
		.marker = info->markers,
		.ptdump = {
		.note_page = note_page,
		.range = (struct ptdump_range[]){
		{info->base_addr, end},
		{0, 0}
		}
		} while (pgdp++, addr = next, addr != end);
		}

		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);
		ptdump_walk_pgd(&st.ptdump, info->mm);
		}

		static void ptdump_initialize(void)
		@@ -399,10 +351,17 @@ void ptdump_check_wx(void)
		{ -1, NULL},
		},
		.check_wx = true,
		.ptdump = {
		.note_page = note_page,
		.range = (struct ptdump_range[]) {
		{PAGE_OFFSET, ~0UL},
		{0, 0}
		}
		}
		};

		walk_pgd(&st, &init_mm, PAGE_OFFSET);
		note_page(&st, 0, 0, 0);
		ptdump_walk_pgd(&st.ptdump, &init_mm);

		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);

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