1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2010 Werner Fink, Jiri Slaby
4 */
5
6 #include <linux/console.h>
7 #include <linux/kernel.h>
8 #include <linux/proc_fs.h>
9 #include <linux/seq_file.h>
10 #include <linux/tty_driver.h>
11
12 /*
13 * This is handler for /proc/consoles
14 */
show_console_dev(struct seq_file * m,void * v)15 static int show_console_dev(struct seq_file *m, void *v)
16 {
17 static const struct {
18 short flag;
19 char name;
20 } con_flags[] = {
21 { CON_ENABLED, 'E' },
22 { CON_CONSDEV, 'C' },
23 { CON_BOOT, 'B' },
24 { CON_PRINTBUFFER, 'p' },
25 { CON_BRL, 'b' },
26 { CON_ANYTIME, 'a' },
27 };
28 char flags[ARRAY_SIZE(con_flags) + 1];
29 struct console *con = v;
30 unsigned int a;
31 dev_t dev = 0;
32
33 if (con->device) {
34 const struct tty_driver *driver;
35 int index;
36 driver = con->device(con, &index);
37 if (driver) {
38 dev = MKDEV(driver->major, driver->minor_start);
39 dev += index;
40 }
41 }
42
43 for (a = 0; a < ARRAY_SIZE(con_flags); a++)
44 flags[a] = (con->flags & con_flags[a].flag) ?
45 con_flags[a].name : ' ';
46 flags[a] = 0;
47
48 seq_setwidth(m, 21 - 1);
49 seq_printf(m, "%s%d", con->name, con->index);
50 seq_pad(m, ' ');
51 seq_printf(m, "%c%c%c (%s)", con->read ? 'R' : '-',
52 con->write ? 'W' : '-', con->unblank ? 'U' : '-',
53 flags);
54 if (dev)
55 seq_printf(m, " %4d:%d", MAJOR(dev), MINOR(dev));
56
57 seq_putc(m, '\n');
58 return 0;
59 }
60
c_start(struct seq_file * m,loff_t * pos)61 static void *c_start(struct seq_file *m, loff_t *pos)
62 {
63 struct console *con;
64 loff_t off = 0;
65
66 console_lock();
67 for_each_console(con)
68 if (off++ == *pos)
69 break;
70
71 return con;
72 }
73
c_next(struct seq_file * m,void * v,loff_t * pos)74 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
75 {
76 struct console *con = v;
77 ++*pos;
78 return con->next;
79 }
80
c_stop(struct seq_file * m,void * v)81 static void c_stop(struct seq_file *m, void *v)
82 {
83 console_unlock();
84 }
85
86 static const struct seq_operations consoles_op = {
87 .start = c_start,
88 .next = c_next,
89 .stop = c_stop,
90 .show = show_console_dev
91 };
92
proc_consoles_init(void)93 static int __init proc_consoles_init(void)
94 {
95 proc_create_seq("consoles", 0, NULL, &consoles_op);
96 return 0;
97 }
98 fs_initcall(proc_consoles_init);
99