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/pgtable.h>
26 #include <asm/tlb.h>
27 #include <asm/div64.h>
28 #include "internal.h"
29
30 /*
31 * display a single region to a sequenced file
32 */
nommu_region_show(struct seq_file * m,struct vm_region * region)33 static int nommu_region_show(struct seq_file *m, struct vm_region *region)
34 {
35 unsigned long ino = 0;
36 struct file *file;
37 dev_t dev = 0;
38 int flags;
39
40 flags = region->vm_flags;
41 file = region->vm_file;
42
43 if (file) {
44 struct inode *inode = file_inode(region->vm_file);
45 dev = inode->i_sb->s_dev;
46 ino = inode->i_ino;
47 }
48
49 seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
50 seq_printf(m,
51 "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
52 region->vm_start,
53 region->vm_end,
54 flags & VM_READ ? 'r' : '-',
55 flags & VM_WRITE ? 'w' : '-',
56 flags & VM_EXEC ? 'x' : '-',
57 flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
58 ((loff_t)region->vm_pgoff) << PAGE_SHIFT,
59 MAJOR(dev), MINOR(dev), ino);
60
61 if (file) {
62 seq_pad(m, ' ');
63 seq_file_path(m, file, "");
64 }
65
66 seq_putc(m, '\n');
67 return 0;
68 }
69
70 /*
71 * display a list of all the REGIONs the kernel knows about
72 * - nommu kernels have a single flat list
73 */
nommu_region_list_show(struct seq_file * m,void * _p)74 static int nommu_region_list_show(struct seq_file *m, void *_p)
75 {
76 struct rb_node *p = _p;
77
78 return nommu_region_show(m, rb_entry(p, struct vm_region, vm_rb));
79 }
80
nommu_region_list_start(struct seq_file * m,loff_t * _pos)81 static void *nommu_region_list_start(struct seq_file *m, loff_t *_pos)
82 {
83 struct rb_node *p;
84 loff_t pos = *_pos;
85
86 down_read(&nommu_region_sem);
87
88 for (p = rb_first(&nommu_region_tree); p; p = rb_next(p))
89 if (pos-- == 0)
90 return p;
91 return NULL;
92 }
93
nommu_region_list_stop(struct seq_file * m,void * v)94 static void nommu_region_list_stop(struct seq_file *m, void *v)
95 {
96 up_read(&nommu_region_sem);
97 }
98
nommu_region_list_next(struct seq_file * m,void * v,loff_t * pos)99 static void *nommu_region_list_next(struct seq_file *m, void *v, loff_t *pos)
100 {
101 (*pos)++;
102 return rb_next((struct rb_node *) v);
103 }
104
105 static const struct seq_operations proc_nommu_region_list_seqop = {
106 .start = nommu_region_list_start,
107 .next = nommu_region_list_next,
108 .stop = nommu_region_list_stop,
109 .show = nommu_region_list_show
110 };
111
proc_nommu_init(void)112 static int __init proc_nommu_init(void)
113 {
114 proc_create_seq("maps", S_IRUGO, NULL, &proc_nommu_region_list_seqop);
115 return 0;
116 }
117
118 fs_initcall(proc_nommu_init);
119