1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Module proc support
4 *
5 * Copyright (C) 2008 Alexey Dobriyan
6 */
7
8 #include <linux/module.h>
9 #include <linux/kallsyms.h>
10 #include <linux/mutex.h>
11 #include <linux/seq_file.h>
12 #include <linux/proc_fs.h>
13 #include "internal.h"
14
15 #ifdef CONFIG_MODULE_UNLOAD
16 static inline void print_unload_info(struct seq_file *m, struct module *mod)
17 {
18 struct module_use *use;
19 int printed_something = 0;
20
21 seq_printf(m, " %i ", module_refcount(mod));
22
23 /*
24 * Always include a trailing , so userspace can differentiate
25 * between this and the old multi-field proc format.
26 */
27 list_for_each_entry(use, &mod->source_list, source_list) {
28 printed_something = 1;
29 seq_printf(m, "%s,", use->source->name);
30 }
31
32 if (mod->init && !mod->exit) {
33 printed_something = 1;
34 seq_puts(m, "[permanent],");
35 }
36
37 if (!printed_something)
38 seq_puts(m, "-");
39 }
40 #else /* !CONFIG_MODULE_UNLOAD */
41 static inline void print_unload_info(struct seq_file *m, struct module *mod)
42 {
43 /* We don't know the usage count, or what modules are using. */
44 seq_puts(m, " - -");
45 }
46 #endif /* CONFIG_MODULE_UNLOAD */
47
48 /* Called by the /proc file system to return a list of modules. */
49 static void *m_start(struct seq_file *m, loff_t *pos)
50 {
51 mutex_lock(&module_mutex);
52 return seq_list_start(&modules, *pos);
53 }
54
55 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
56 {
57 return seq_list_next(p, &modules, pos);
58 }
59
60 static void m_stop(struct seq_file *m, void *p)
61 {
62 mutex_unlock(&module_mutex);
63 }
64
65 static unsigned int module_total_size(struct module *mod)
66 {
67 int size = 0;
68
69 for_each_mod_mem_type(type)
70 size += mod->mem[type].size;
71 return size;
72 }
73
74 static int m_show(struct seq_file *m, void *p)
75 {
76 struct module *mod = list_entry(p, struct module, list);
77 char buf[MODULE_FLAGS_BUF_SIZE];
78 void *value;
79 unsigned int size;
80
81 /* We always ignore unformed modules. */
82 if (mod->state == MODULE_STATE_UNFORMED)
83 return 0;
84
85 size = module_total_size(mod);
86 seq_printf(m, "%s %u", mod->name, size);
87 print_unload_info(m, mod);
88
89 /* Informative for users. */
90 seq_printf(m, " %s",
91 mod->state == MODULE_STATE_GOING ? "Unloading" :
92 mod->state == MODULE_STATE_COMING ? "Loading" :
93 "Live");
94 /* Used by oprofile and other similar tools. */
95 value = m->private ? NULL : mod->mem[MOD_TEXT].base;
96 seq_printf(m, " 0x%px", value);
97
98 /* Taints info */
99 if (mod->taints)
100 seq_printf(m, " %s", module_flags(mod, buf, true));
101
102 seq_puts(m, "\n");
103 return 0;
104 }
105
106 /*
107 * Format: modulename size refcount deps address
108 *
109 * Where refcount is a number or -, and deps is a comma-separated list
110 * of depends or -.
111 */
112 static const struct seq_operations modules_op = {
113 .start = m_start,
114 .next = m_next,
115 .stop = m_stop,
116 .show = m_show
117 };
118
119 /*
120 * This also sets the "private" pointer to non-NULL if the
121 * kernel pointers should be hidden (so you can just test
122 * "m->private" to see if you should keep the values private).
123 *
124 * We use the same logic as for /proc/kallsyms.
125 */
126 static int modules_open(struct inode *inode, struct file *file)
127 {
128 int err = seq_open(file, &modules_op);
129
130 if (!err) {
131 struct seq_file *m = file->private_data;
132
133 m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul;
134 }
135
136 return err;
137 }
138
139 static const struct proc_ops modules_proc_ops = {
140 .proc_flags = PROC_ENTRY_PERMANENT,
141 .proc_open = modules_open,
142 .proc_read = seq_read,
143 .proc_lseek = seq_lseek,
144 .proc_release = seq_release,
145 };
146
147 static int __init proc_modules_init(void)
148 {
149 proc_create("modules", 0, NULL, &modules_proc_ops);
150 return 0;
151 }
152 module_init(proc_modules_init);
153
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