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