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 */
 15static 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
 37		/*
 38		 * Take console_lock to serialize device() callback with
 39		 * other console operations. For example, fg_console is
 40		 * modified under console_lock when switching vt.
 41		 */
 42		console_lock();
 43		driver = con->device(con, &index);
 44		console_unlock();
 45
 46		if (driver) {
 47			dev = MKDEV(driver->major, driver->minor_start);
 48			dev += index;
 49		}
 50	}
 51
 52	for (a = 0; a < ARRAY_SIZE(con_flags); a++)
 53		flags[a] = (con->flags & con_flags[a].flag) ?
 54			con_flags[a].name : ' ';
 55	flags[a] = 0;
 56
 57	seq_setwidth(m, 21 - 1);
 58	seq_printf(m, "%s%d", con->name, con->index);
 59	seq_pad(m, ' ');
 60	seq_printf(m, "%c%c%c (%s)", con->read ? 'R' : '-',
 61			con->write ? 'W' : '-', con->unblank ? 'U' : '-',
 62			flags);
 63	if (dev)
 64		seq_printf(m, " %4d:%d", MAJOR(dev), MINOR(dev));
 65
 66	seq_putc(m, '\n');
 67	return 0;
 68}
 69
 70static void *c_start(struct seq_file *m, loff_t *pos)
 71{
 72	struct console *con;
 73	loff_t off = 0;
 74
 75	/*
 76	 * Hold the console_list_lock to guarantee safe traversal of the
 77	 * console list. SRCU cannot be used because there is no
 78	 * place to store the SRCU cookie.
 79	 */
 80	console_list_lock();
 81	for_each_console(con)
 82		if (off++ == *pos)
 83			break;
 84
 85	return con;
 86}
 87
 88static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 89{
 90	struct console *con = v;
 91
 92	++*pos;
 93	return hlist_entry_safe(con->node.next, struct console, node);
 94}
 95
 96static void c_stop(struct seq_file *m, void *v)
 97{
 98	console_list_unlock();
 99}
100
101static const struct seq_operations consoles_op = {
102	.start	= c_start,
103	.next	= c_next,
104	.stop	= c_stop,
105	.show	= show_console_dev
106};
107
108static int __init proc_consoles_init(void)
109{
110	proc_create_seq("consoles", 0, NULL, &consoles_op);
111	return 0;
112}
113fs_initcall(proc_consoles_init);

  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 */
 15static 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
 37		/*
 38		 * Take console_lock to serialize device() callback with
 39		 * other console operations. For example, fg_console is
 40		 * modified under console_lock when switching vt.
 41		 */
 42		console_lock();
 43		driver = con->device(con, &index);
 44		console_unlock();
 45
 46		if (driver) {
 47			dev = MKDEV(driver->major, driver->minor_start);
 48			dev += index;
 49		}
 50	}
 51
 52	for (a = 0; a < ARRAY_SIZE(con_flags); a++)
 53		flags[a] = (con->flags & con_flags[a].flag) ?
 54			con_flags[a].name : ' ';
 55	flags[a] = 0;
 56
 57	seq_setwidth(m, 21 - 1);
 58	seq_printf(m, "%s%d", con->name, con->index);
 59	seq_pad(m, ' ');
 60	seq_printf(m, "%c%c%c (%s)", con->read ? 'R' : '-',
 61			con->write ? 'W' : '-', con->unblank ? 'U' : '-',
 62			flags);
 63	if (dev)
 64		seq_printf(m, " %4d:%d", MAJOR(dev), MINOR(dev));
 65
 66	seq_putc(m, '\n');
 67	return 0;
 68}
 69
 70static void *c_start(struct seq_file *m, loff_t *pos)
 71{
 72	struct console *con;
 73	loff_t off = 0;
 74
 75	/*
 76	 * Hold the console_list_lock to guarantee safe traversal of the
 77	 * console list. SRCU cannot be used because there is no
 78	 * place to store the SRCU cookie.
 79	 */
 80	console_list_lock();
 81	for_each_console(con)
 82		if (off++ == *pos)
 83			break;
 84
 85	return con;
 86}
 87
 88static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 89{
 90	struct console *con = v;
 91
 92	++*pos;
 93	return hlist_entry_safe(con->node.next, struct console, node);
 94}
 95
 96static void c_stop(struct seq_file *m, void *v)
 97{
 98	console_list_unlock();
 99}
100
101static const struct seq_operations consoles_op = {
102	.start	= c_start,
103	.next	= c_next,
104	.stop	= c_stop,
105	.show	= show_console_dev
106};
107
108static int __init proc_consoles_init(void)
109{
110	proc_create_seq("consoles", 0, NULL, &consoles_op);
111	return 0;
112}
113fs_initcall(proc_consoles_init);