Include missing linux/slab.h inclusions
[linux-3.10.git] / fs / proc / proc_tty.c
1 /*
2  * proc_tty.c -- handles /proc/tty
3  *
4  * Copyright 1997, Theodore Ts'o
5  */
6
7 #include <asm/uaccess.h>
8 #include <linux/module.h>
9 #include <linux/init.h>
10 #include <linux/errno.h>
11 #include <linux/time.h>
12 #include <linux/proc_fs.h>
13 #include <linux/stat.h>
14 #include <linux/tty.h>
15 #include <linux/seq_file.h>
16 #include <linux/bitops.h>
17
18 /*
19  * The /proc/tty directory inodes...
20  */
21 static struct proc_dir_entry *proc_tty_ldisc, *proc_tty_driver;
22
23 /*
24  * This is the handler for /proc/tty/drivers
25  */
26 static void show_tty_range(struct seq_file *m, struct tty_driver *p,
27         dev_t from, int num)
28 {
29         seq_printf(m, "%-20s ", p->driver_name ? p->driver_name : "unknown");
30         seq_printf(m, "/dev/%-8s ", p->name);
31         if (p->num > 1) {
32                 seq_printf(m, "%3d %d-%d ", MAJOR(from), MINOR(from),
33                         MINOR(from) + num - 1);
34         } else {
35                 seq_printf(m, "%3d %7d ", MAJOR(from), MINOR(from));
36         }
37         switch (p->type) {
38         case TTY_DRIVER_TYPE_SYSTEM:
39                 seq_puts(m, "system");
40                 if (p->subtype == SYSTEM_TYPE_TTY)
41                         seq_puts(m, ":/dev/tty");
42                 else if (p->subtype == SYSTEM_TYPE_SYSCONS)
43                         seq_puts(m, ":console");
44                 else if (p->subtype == SYSTEM_TYPE_CONSOLE)
45                         seq_puts(m, ":vtmaster");
46                 break;
47         case TTY_DRIVER_TYPE_CONSOLE:
48                 seq_puts(m, "console");
49                 break;
50         case TTY_DRIVER_TYPE_SERIAL:
51                 seq_puts(m, "serial");
52                 break;
53         case TTY_DRIVER_TYPE_PTY:
54                 if (p->subtype == PTY_TYPE_MASTER)
55                         seq_puts(m, "pty:master");
56                 else if (p->subtype == PTY_TYPE_SLAVE)
57                         seq_puts(m, "pty:slave");
58                 else
59                         seq_puts(m, "pty");
60                 break;
61         default:
62                 seq_printf(m, "type:%d.%d", p->type, p->subtype);
63         }
64         seq_putc(m, '\n');
65 }
66
67 static int show_tty_driver(struct seq_file *m, void *v)
68 {
69         struct tty_driver *p = list_entry(v, struct tty_driver, tty_drivers);
70         dev_t from = MKDEV(p->major, p->minor_start);
71         dev_t to = from + p->num;
72
73         if (&p->tty_drivers == tty_drivers.next) {
74                 /* pseudo-drivers first */
75                 seq_printf(m, "%-20s /dev/%-8s ", "/dev/tty", "tty");
76                 seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 0);
77                 seq_puts(m, "system:/dev/tty\n");
78                 seq_printf(m, "%-20s /dev/%-8s ", "/dev/console", "console");
79                 seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 1);
80                 seq_puts(m, "system:console\n");
81 #ifdef CONFIG_UNIX98_PTYS
82                 seq_printf(m, "%-20s /dev/%-8s ", "/dev/ptmx", "ptmx");
83                 seq_printf(m, "%3d %7d ", TTYAUX_MAJOR, 2);
84                 seq_puts(m, "system\n");
85 #endif
86 #ifdef CONFIG_VT
87                 seq_printf(m, "%-20s /dev/%-8s ", "/dev/vc/0", "vc/0");
88                 seq_printf(m, "%3d %7d ", TTY_MAJOR, 0);
89                 seq_puts(m, "system:vtmaster\n");
90 #endif
91         }
92
93         while (MAJOR(from) < MAJOR(to)) {
94                 dev_t next = MKDEV(MAJOR(from)+1, 0);
95                 show_tty_range(m, p, from, next - from);
96                 from = next;
97         }
98         if (from != to)
99                 show_tty_range(m, p, from, to - from);
100         return 0;
101 }
102
103 /* iterator */
104 static void *t_start(struct seq_file *m, loff_t *pos)
105 {
106         mutex_lock(&tty_mutex);
107         return seq_list_start(&tty_drivers, *pos);
108 }
109
110 static void *t_next(struct seq_file *m, void *v, loff_t *pos)
111 {
112         return seq_list_next(v, &tty_drivers, pos);
113 }
114
115 static void t_stop(struct seq_file *m, void *v)
116 {
117         mutex_unlock(&tty_mutex);
118 }
119
120 static const struct seq_operations tty_drivers_op = {
121         .start  = t_start,
122         .next   = t_next,
123         .stop   = t_stop,
124         .show   = show_tty_driver
125 };
126
127 static int tty_drivers_open(struct inode *inode, struct file *file)
128 {
129         return seq_open(file, &tty_drivers_op);
130 }
131
132 static const struct file_operations proc_tty_drivers_operations = {
133         .open           = tty_drivers_open,
134         .read           = seq_read,
135         .llseek         = seq_lseek,
136         .release        = seq_release,
137 };
138
139 /*
140  * This function is called by tty_register_driver() to handle
141  * registering the driver's /proc handler into /proc/tty/driver/<foo>
142  */
143 void proc_tty_register_driver(struct tty_driver *driver)
144 {
145         struct proc_dir_entry *ent;
146                 
147         if (!driver->driver_name || driver->proc_entry ||
148             !driver->ops->proc_fops)
149                 return;
150
151         ent = proc_create_data(driver->driver_name, 0, proc_tty_driver,
152                                driver->ops->proc_fops, driver);
153         driver->proc_entry = ent;
154 }
155
156 /*
157  * This function is called by tty_unregister_driver()
158  */
159 void proc_tty_unregister_driver(struct tty_driver *driver)
160 {
161         struct proc_dir_entry *ent;
162
163         ent = driver->proc_entry;
164         if (!ent)
165                 return;
166                 
167         remove_proc_entry(driver->driver_name, proc_tty_driver);
168         
169         driver->proc_entry = NULL;
170 }
171
172 /*
173  * Called by proc_root_init() to initialize the /proc/tty subtree
174  */
175 void __init proc_tty_init(void)
176 {
177         if (!proc_mkdir("tty", NULL))
178                 return;
179         proc_tty_ldisc = proc_mkdir("tty/ldisc", NULL);
180         /*
181          * /proc/tty/driver/serial reveals the exact character counts for
182          * serial links which is just too easy to abuse for inferring
183          * password lengths and inter-keystroke timings during password
184          * entry.
185          */
186         proc_tty_driver = proc_mkdir_mode("tty/driver", S_IRUSR|S_IXUSR, NULL);
187         proc_create("tty/ldiscs", 0, NULL, &tty_ldiscs_proc_fops);
188         proc_create("tty/drivers", 0, NULL, &proc_tty_drivers_operations);
189 }