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, fmt: " %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, fmt: "%s," , use->source->name); |
30 | } |
31 | |
32 | if (mod->init && !mod->exit) { |
33 | printed_something = 1; |
34 | seq_puts(m, s: "[permanent]," ); |
35 | } |
36 | |
37 | if (!printed_something) |
38 | seq_puts(m, s: "-" ); |
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(head: &modules, pos: *pos); |
53 | } |
54 | |
55 | static void *m_next(struct seq_file *m, void *p, loff_t *pos) |
56 | { |
57 | return seq_list_next(v: p, head: &modules, ppos: pos); |
58 | } |
59 | |
60 | static void m_stop(struct seq_file *m, void *p) |
61 | { |
62 | mutex_unlock(lock: &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, fmt: "%s %u" , mod->name, size); |
87 | print_unload_info(m, mod); |
88 | |
89 | /* Informative for users. */ |
90 | seq_printf(m, fmt: " %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, fmt: " 0x%px" , value); |
97 | |
98 | /* Taints info */ |
99 | if (mod->taints) |
100 | seq_printf(m, fmt: " %s" , module_flags(mod, buf, show_state: true)); |
101 | |
102 | seq_puts(m, s: "\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(cred: 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(name: "modules" , mode: 0, NULL, proc_ops: &modules_proc_ops); |
150 | return 0; |
151 | } |
152 | module_init(proc_modules_init); |
153 | |