ARM: 8735/1: mm: dump: make page table dumping reusable (4fb69cc4) · Commits · 戴 / test

arch/arm/Kconfig.debug

+5 −1

Original line number	Diff line number	Diff line
		@@ -3,10 +3,14 @@ menu "Kernel hacking"

		source "lib/Kconfig.debug"

		config ARM_PTDUMP
		config ARM_PTDUMP_CORE
		def_bool n

		config ARM_PTDUMP_DEBUGFS
		bool "Export kernel pagetable layout to userspace via debugfs"
		depends on DEBUG_KERNEL
		depends on MMU
		select ARM_PTDUMP_CORE
		select DEBUG_FS
		---help---
		Say Y here if you want to show the kernel pagetable layout in a

arch/arm/include/asm/ptdump.h

0 → 100644

+35 −0

Original line number	Diff line number	Diff line
		/* SPDX-License-Identifier: GPL-2.0 */
		/* Copyright (C) 2014 ARM Ltd. */
		#ifndef __ASM_PTDUMP_H
		#define __ASM_PTDUMP_H

		#ifdef CONFIG_ARM_PTDUMP_CORE

		#include <linux/mm_types.h>
		#include <linux/seq_file.h>

		struct addr_marker {
		unsigned long start_address;
		char *name;
		};

		struct ptdump_info {
		struct mm_struct *mm;
		const struct addr_marker *markers;
		unsigned long base_addr;
		};

		void ptdump_walk_pgd(struct seq_file s, struct ptdump_info info);
		#ifdef CONFIG_ARM_PTDUMP_DEBUGFS
		int ptdump_debugfs_register(struct ptdump_info info, const char name);
		#else
		static inline int ptdump_debugfs_register(struct ptdump_info *info,
		const char *name)
		{
		return 0;
		}
		#endif /* CONFIG_ARM_PTDUMP_DEBUGFS */

		#endif /* CONFIG_ARM_PTDUMP_CORE */

		#endif /* __ASM_PTDUMP_H */

arch/arm/mm/Makefile

+2 −1

Original line number	Diff line number	Diff line
		@@ -13,7 +13,8 @@ obj-y += nommu.o
		obj-$(CONFIG_ARM_MPU) += pmsa-v7.o
		endif

		obj-$(CONFIG_ARM_PTDUMP) += dump.o
		obj-$(CONFIG_ARM_PTDUMP_CORE) += dump.o
		obj-$(CONFIG_ARM_PTDUMP_DEBUGFS) += ptdump_debugfs.o
		obj-$(CONFIG_MODULES) += proc-syms.o
		obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o

arch/arm/mm/dump.c

+28 −37

Original line number	Diff line number	Diff line
		@@ -21,11 +21,7 @@
		#include <asm/fixmap.h>
		#include <asm/memory.h>
		#include <asm/pgtable.h>

		struct addr_marker {
		unsigned long start_address;
		const char *name;
		};
		#include <asm/ptdump.h>

		static struct addr_marker address_markers[] = {
		{ MODULES_VADDR, "Modules" },
		@@ -335,50 +331,36 @@ static void walk_pud(struct pg_state st, pgd_t pgd, unsigned long start)
		}
		}

		static void walk_pgd(struct seq_file *m)
		static void walk_pgd(struct pg_state st, struct mm_struct mm,
		unsigned long start)
		{
		pgd_t *pgd = swapper_pg_dir;
		struct pg_state st;
		unsigned long addr;
		pgd_t *pgd = pgd_offset(mm, 0UL);
		unsigned i;

		memset(&st, 0, sizeof(st));
		st.seq = m;
		st.marker = address_markers;
		unsigned long addr;

		for (i = 0; i < PTRS_PER_PGD; i++, pgd++) {
		addr = i * PGDIR_SIZE;
		addr = start + i * PGDIR_SIZE;
		if (!pgd_none(*pgd)) {
		walk_pud(&st, pgd, addr);
		walk_pud(st, pgd, addr);
		} else {
		note_page(&st, addr, 1, pgd_val(*pgd), NULL);
		note_page(st, addr, 1, pgd_val(*pgd), NULL);
		}
		}

		note_page(&st, 0, 0, 0, NULL);
		}

		static int ptdump_show(struct seq_file m, void v)
		void ptdump_walk_pgd(struct seq_file m, struct ptdump_info info)
		{
		walk_pgd(m);
		return 0;
		}
		struct pg_state st = {
		.seq = m,
		.marker = info->markers,
		};

		static int ptdump_open(struct inode inode, struct file file)
		{
		return single_open(file, ptdump_show, NULL);
		walk_pgd(&st, info->mm, info->base_addr);
		note_page(&st, 0, 0, 0, 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)
		static void ptdump_initialize(void)
		{
		struct dentry *pe;
		unsigned i, j;

		for (i = 0; i < ARRAY_SIZE(pg_level); i++)
		@@ -387,9 +369,18 @@ static int ptdump_init(void)
		pg_level[i].mask \|= pg_level[i].bits[j].mask;

		address_markers[2].start_address = VMALLOC_START;
		}

		static struct ptdump_info kernel_ptdump_info = {
		.mm = &init_mm,
		.markers = address_markers,
		.base_addr = 0,
		};

		pe = debugfs_create_file("kernel_page_tables", 0400, NULL, NULL,
		&ptdump_fops);
		return pe ? 0 : -ENOMEM;
		static int ptdump_init(void)
		{
		ptdump_initialize();
		return ptdump_debugfs_register(&kernel_ptdump_info,
		"kernel_page_tables");
		}
		__initcall(ptdump_init);

arch/arm/mm/ptdump_debugfs.c

0 → 100644

+34 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		#include <linux/debugfs.h>
		#include <linux/seq_file.h>

		#include <asm/ptdump.h>

		static int ptdump_show(struct seq_file m, void v)
		{
		struct ptdump_info *info = m->private;

		ptdump_walk_pgd(m, info);
		return 0;
		}

		static int ptdump_open(struct inode inode, struct file file)
		{
		return single_open(file, ptdump_show, inode->i_private);
		}

		static const struct file_operations ptdump_fops = {
		.open = ptdump_open,
		.read = seq_read,
		.llseek = seq_lseek,
		.release = single_release,
		};

		int ptdump_debugfs_register(struct ptdump_info info, const char name)
		{
		struct dentry *pe;

		pe = debugfs_create_file(name, 0400, NULL, info, &ptdump_fops);
		return pe ? 0 : -ENOMEM;

		}

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