path: root/drivers/char/vt_ioctl.c

/*
 *  linux/drivers/char/vt_ioctl.c
 *
 *  Copyright (C) 1992 obz under the linux copyright
 *
 *  Dynamic diacritical handling - aeb@cwi.nl - Dec 1993
 *  Dynamic keymap and string allocation - aeb@cwi.nl - May 1994
 *  Restrict VT switching via ioctl() - grif@cs.ucr.edu - Dec 1995
 *  Some code moved for less code duplication - Andi Kleen - Mar 1997
 *  Check put/get_user, cleanups - acme@conectiva.com.br - Jun 2001
 */

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/tty.h>
#include <linux/timer.h>
#include <linux/kernel.h>
#include <linux/kd.h>
#include <linux/vt.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/major.h>
#include <linux/fs.h>
#include <linux/console.h>
#include <linux/signal.h>
#include <linux/timex.h>

#include <asm/io.h>
#include <asm/uaccess.h>

#include <linux/kbd_kern.h>
#include <linux/vt_kern.h>
#include <linux/kbd_diacr.h>
#include <linux/selection.h>

char vt_dont_switch;
extern struct tty_driver *console_driver;

#define VT_IS_IN_USE(i)	(console_driver->ttys[i] && console_driver->ttys[i]->count)
#define VT_BUSY(i)	(VT_IS_IN_USE(i) || i == fg_console || vc_cons[i].d == sel_cons)

/*
 * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
 * experimentation and study of X386 SYSV handling.
 *
 * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
 * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
 * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
 * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
 * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
 * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
 * to the current console is done by the main ioctl code.
 */

#ifdef CONFIG_X86
#include <linux/syscalls.h>
#endif

static void complete_change_console(struct vc_data *vc);

/*
 * these are the valid i/o ports we're allowed to change. they map all the
 * video ports
 */
#define GPFIRST 0x3b4
#define GPLAST 0x3df
#define GPNUM (GPLAST - GPFIRST + 1)

#define i (tmp.kb_index)
#define s (tmp.kb_table)
#define v (tmp.kb_value)
static inline int
do_kdsk_ioctl(int cmd, struct kbentry __user *user_kbe, int perm, struct kbd_struct *kbd)
{
	struct kbentry tmp;
	ushort *key_map, val, ov;

	if (copy_from_user(&tmp, user_kbe, sizeof(struct kbentry)))
		return -EFAULT;

	if (!capable(CAP_SYS_TTY_CONFIG))
		perm = 0;

	switch (cmd) {
	case KDGKBENT:
		key_map = key_maps[s];
		if (key_map) {
		    val = U(key_map[i]);
		    if (kbd->kbdmode != VC_UNICODE && KTYP(val) >= NR_TYPES)
			val = K_HOLE;
		} else
		    val = (i ? K_HOLE : K_NOSUCHMAP);
		return put_user(val, &user_kbe->kb_value);
	case KDSKBENT:
		if (!perm)
			return -EPERM;
		if (!i && v == K_NOSUCHMAP) {
			/* deallocate map */
			key_map = key_maps[s];
			if (s && key_map) {
			    key_maps[s] = NULL;
			    if (key_map[0] == U(K_ALLOCATED)) {
					kfree(key_map);
					keymap_count--;
			    }
			}
			break;
		}

		if (KTYP(v) < NR_TYPES) {
		    if (KVAL(v) > max_vals[KTYP(v)])