1/* nommu.c: mmu-less memory info files
2 *
3 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/errno.h>
15#include <linux/time.h>
16#include <linux/kernel.h>
17#include <linux/string.h>
18#include <linux/mman.h>
19#include <linux/proc_fs.h>
20#include <linux/mm.h>
21#include <linux/mmzone.h>
22#include <linux/pagemap.h>
23#include <linux/swap.h>
24#include <linux/smp.h>
25#include <linux/seq_file.h>
26#include <linux/hugetlb.h>
27#include <linux/vmalloc.h>
28#include <asm/uaccess.h>
29#include <asm/pgtable.h>
30#include <asm/tlb.h>
31#include <asm/div64.h>
32#include "internal.h"
33
34/*
35 * display a single region to a sequenced file
36 */
37static int nommu_region_show(struct seq_file *m, struct vm_region *region)
38{
39	unsigned long ino = 0;
40	struct file *file;
41	dev_t dev = 0;
42	int flags, len;
43
44	flags = region->vm_flags;
45	file = region->vm_file;
46
47	if (file) {
48		struct inode *inode = region->vm_file->f_path.dentry->d_inode;
49		dev = inode->i_sb->s_dev;
50		ino = inode->i_ino;
51	}
52
53	seq_printf(m,
54		   "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",
55		   region->vm_start,
56		   region->vm_end,
57		   flags & VM_READ ? 'r' : '-',
58		   flags & VM_WRITE ? 'w' : '-',
59		   flags & VM_EXEC ? 'x' : '-',
60		   flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
61		   ((loff_t)region->vm_pgoff) << PAGE_SHIFT,
62		   MAJOR(dev), MINOR(dev), ino, &len);
63
64	if (file) {
65		len = 25 + sizeof(void *) * 6 - len;
66		if (len < 1)
67			len = 1;
68		seq_printf(m, "%*c", len, ' ');
69		seq_path(m, &file->f_path, "");
70	}
71
72	seq_putc(m, '\n');
73	return 0;
74}
75
76/*
77 * display a list of all the REGIONs the kernel knows about
78 * - nommu kernels have a single flat list
79 */
80static int nommu_region_list_show(struct seq_file *m, void *_p)
81{
82	struct rb_node *p = _p;
83
84	return nommu_region_show(m, rb_entry(p, struct vm_region, vm_rb));
85}
86
87static void *nommu_region_list_start(struct seq_file *m, loff_t *_pos)
88{
89	struct rb_node *p;
90	loff_t pos = *_pos;
91
92	down_read(&nommu_region_sem);
93
94	for (p = rb_first(&nommu_region_tree); p; p = rb_next(p))
95		if (pos-- == 0)
96			return p;
97	return NULL;
98}
99
100static void nommu_region_list_stop(struct seq_file *m, void *v)
101{
102	up_read(&nommu_region_sem);
103}
104
105static void *nommu_region_list_next(struct seq_file *m, void *v, loff_t *pos)
106{
107	(*pos)++;
108	return rb_next((struct rb_node *) v);
109}
110
111static const struct seq_operations proc_nommu_region_list_seqop = {
112	.start	= nommu_region_list_start,
113	.next	= nommu_region_list_next,
114	.stop	= nommu_region_list_stop,
115	.show	= nommu_region_list_show
116};
117
118static int proc_nommu_region_list_open(struct inode *inode, struct file *file)
119{
120	return seq_open(file, &proc_nommu_region_list_seqop);
121}
122
123static const struct file_operations proc_nommu_region_list_operations = {
124	.open    = proc_nommu_region_list_open,
125	.read    = seq_read,
126	.llseek  = seq_lseek,
127	.release = seq_release,
128};
129
130static int __init proc_nommu_init(void)
131{
132	proc_create("maps", S_IRUGO, NULL, &proc_nommu_region_list_operations);
133	return 0;
134}
135
136module_init(proc_nommu_init);
137