1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* nommu.c: mmu-less memory info files
3 *
4 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8 #include <linux/init.h>
9 #include <linux/module.h>
10 #include <linux/errno.h>
11 #include <linux/time.h>
12 #include <linux/kernel.h>
13 #include <linux/string.h>
14 #include <linux/mman.h>
15 #include <linux/proc_fs.h>
16 #include <linux/mm.h>
17 #include <linux/mmzone.h>
18 #include <linux/pagemap.h>
19 #include <linux/swap.h>
20 #include <linux/smp.h>
21 #include <linux/seq_file.h>
22 #include <linux/hugetlb.h>
23 #include <linux/vmalloc.h>
24 #include <linux/uaccess.h>
25 #include <asm/tlb.h>
26 #include <asm/div64.h>
27 #include "internal.h"
28
29 /*
30 * display a single region to a sequenced file
31 */
nommu_region_show(struct seq_file * m,struct vm_region * region)32 static int nommu_region_show(struct seq_file *m, struct vm_region *region)
33 {
34 unsigned long ino = 0;
35 struct file *file;
36 dev_t dev = 0;
37 int flags;
38
39 flags = region->vm_flags;
40 file = region->vm_file;
41
42 if (file) {
43 struct inode *inode = file_inode(region->vm_file);
44 dev = inode->i_sb->s_dev;
45 ino = inode->i_ino;
46 }
47
48 seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
49 seq_printf(m,
50 "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
51 region->vm_start,
52 region->vm_end,
53 flags & VM_READ ? 'r' : '-',
54 flags & VM_WRITE ? 'w' : '-',
55 flags & VM_EXEC ? 'x' : '-',
56 flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
57 ((loff_t)region->vm_pgoff) << PAGE_SHIFT,
58 MAJOR(dev), MINOR(dev), ino);
59
60 if (file) {
61 seq_pad(m, ' ');
62 seq_file_path(m, file, "");
63 }
64
65 seq_putc(m, '\n');
66 return 0;
67 }
68
69 /*
70 * display a list of all the REGIONs the kernel knows about
71 * - nommu kernels have a single flat list
72 */
nommu_region_list_show(struct seq_file * m,void * _p)73 static int nommu_region_list_show(struct seq_file *m, void *_p)
74 {
75 struct rb_node *p = _p;
76
77 return nommu_region_show(m, rb_entry(p, struct vm_region, vm_rb));
78 }
79
nommu_region_list_start(struct seq_file * m,loff_t * _pos)80 static void *nommu_region_list_start(struct seq_file *m, loff_t *_pos)
81 {
82 struct rb_node *p;
83 loff_t pos = *_pos;
84
85 down_read(&nommu_region_sem);
86
87 for (p = rb_first(&nommu_region_tree); p; p = rb_next(p))
88 if (pos-- == 0)
89 return p;
90 return NULL;
91 }
92
nommu_region_list_stop(struct seq_file * m,void * v)93 static void nommu_region_list_stop(struct seq_file *m, void *v)
94 {
95 up_read(&nommu_region_sem);
96 }
97
nommu_region_list_next(struct seq_file * m,void * v,loff_t * pos)98 static void *nommu_region_list_next(struct seq_file *m, void *v, loff_t *pos)
99 {
100 (*pos)++;
101 return rb_next((struct rb_node *) v);
102 }
103
104 static const struct seq_operations proc_nommu_region_list_seqop = {
105 .start = nommu_region_list_start,
106 .next = nommu_region_list_next,
107 .stop = nommu_region_list_stop,
108 .show = nommu_region_list_show
109 };
110
proc_nommu_init(void)111 static int __init proc_nommu_init(void)
112 {
113 proc_create_seq("maps", S_IRUGO, NULL, &proc_nommu_region_list_seqop);
114 return 0;
115 }
116
117 fs_initcall(proc_nommu_init);
118