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 */
nommu_region_show(struct seq_file * m,struct vm_region * region)37 static 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 */
nommu_region_list_show(struct seq_file * m,void * _p)80 static 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
nommu_region_list_start(struct seq_file * m,loff_t * _pos)87 static 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
nommu_region_list_stop(struct seq_file * m,void * v)100 static void nommu_region_list_stop(struct seq_file *m, void *v)
101 {
102 up_read(&nommu_region_sem);
103 }
104
nommu_region_list_next(struct seq_file * m,void * v,loff_t * pos)105 static 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
111 static 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
proc_nommu_region_list_open(struct inode * inode,struct file * file)118 static 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
123 static 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
proc_nommu_init(void)130 static int __init proc_nommu_init(void)
131 {
132 proc_create("maps", S_IRUGO, NULL, &proc_nommu_region_list_operations);
133 return 0;
134 }
135
136 module_init(proc_nommu_init);
137