Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1323 insertions, 0 deletions

diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c
new file mode 100644
index 000000000..8c685b501
--- /dev/null
+++ b/drivers/tty/vt/vt_ioctl.c
@@ -0,0 +1,1323 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  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/signal.h>
+#include <linux/tty.h>
+#include <linux/timer.h>
+#include <linux/kernel.h>
+#include <linux/compat.h>
+#include <linux/module.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/consolemap.h>
+#include <linux/signal.h>
+#include <linux/suspend.h>
+#include <linux/timex.h>
+
+#include <asm/io.h>
+#include <linux/uaccess.h>
+
+#include <linux/nospec.h>
+
+#include <linux/kbd_kern.h>
+#include <linux/vt_kern.h>
+#include <linux/kbd_diacr.h>
+#include <linux/selection.h>
+
+bool vt_dont_switch;
+
+static inline bool vt_in_use(unsigned int i)
+{
+	const struct vc_data *vc = vc_cons[i].d;
+
+	/*
+	 * console_lock must be held to prevent the vc from being deallocated
+	 * while we're checking whether it's in-use.
+	 */
+	WARN_CONSOLE_UNLOCKED();
+
+	return vc && kref_read(&vc->port.kref) > 1;
+}
+
+static inline bool vt_busy(int i)
+{
+	if (vt_in_use(i))
+		return true;
+	if (i == fg_console)
+		return true;
+	if (vc_is_sel(vc_cons[i].d))
+		return true;
+
+	return false;
+}
+
+/*
+ * 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 <asm/syscalls.h>
+#endif
+
+static void complete_change_console(struct vc_data *vc);
+
+/*
+ *	User space VT_EVENT handlers
+ */
+
+struct vt_event_wait {
+	struct list_head list;
+	struct vt_event event;
+	int done;
+};
+
+static LIST_HEAD(vt_events);
+static DEFINE_SPINLOCK(vt_event_lock);
+static DECLARE_WAIT_QUEUE_HEAD(vt_event_waitqueue);
+
+/**
+ *	vt_event_post
+ *	@event: the event that occurred
+ *	@old: old console
+ *	@new: new console
+ *
+ *	Post an VT event to interested VT handlers
+ */
+
+void vt_event_post(unsigned int event, unsigned int old, unsigned int new)
+{
+	struct list_head *pos, *head;
+	unsigned long flags;
+	int wake = 0;
+
+	spin_lock_irqsave(&vt_event_lock, flags);
+	head = &vt_events;
+
+	list_for_each(pos, head) {
+		struct vt_event_wait *ve = list_entry(pos,
+						struct vt_event_wait, list);
+		if (!(ve->event.event & event))
+			continue;
+		ve->event.event = event;
+		/* kernel view is consoles 0..n-1, user space view is
+		   console 1..n with 0 meaning current, so we must bias */
+		ve->event.oldev = old + 1;
+		ve->event.newev = new + 1;
+		wake = 1;
+		ve->done = 1;
+	}
+	spin_unlock_irqrestore(&vt_event_lock, flags);
+	if (wake)
+		wake_up_interruptible(&vt_event_waitqueue);
+}
+
+static void __vt_event_queue(struct vt_event_wait *vw)
+{
+	unsigned long flags;
+	/* Prepare the event */
+	INIT_LIST_HEAD(&vw->list);
+	vw->done = 0;
+	/* Queue our event */
+	spin_lock_irqsave(&vt_event_lock, flags);
+	list_add(&vw->list, &vt_events);
+	spin_unlock_irqrestore(&vt_event_lock, flags);
+}
+
+static void __vt_event_wait(struct vt_event_wait *vw)
+{
+	/* Wait for it to pass */
+	wait_event_interruptible(vt_event_waitqueue, vw->done);
+}
+
+static void __vt_event_dequeue(struct vt_event_wait *vw)
+{
+	unsigned long flags;
+
+	/* Dequeue it */
+	spin_lock_irqsave(&vt_event_lock, flags);
+	list_del(&vw->list);
+	spin_unlock_irqrestore(&vt_event_lock, flags);
+}
+
+/**
+ *	vt_event_wait		-	wait for an event
+ *	@vw: our event
+ *
+ *	Waits for an event to occur which completes our vt_event_wait
+ *	structure. On return the structure has wv->done set to 1 for success
+ *	or 0 if some event such as a signal ended the wait.
+ */
+
+static void vt_event_wait(struct vt_event_wait *vw)
+{
+	__vt_event_queue(vw);
+	__vt_event_wait(vw);
+	__vt_event_dequeue(vw);
+}
+
+/**
+ *	vt_event_wait_ioctl	-	event ioctl handler
+ *	@event: argument to ioctl (the event)
+ *
+ *	Implement the VT_WAITEVENT ioctl using the VT event interface
+ */
+
+static int vt_event_wait_ioctl(struct vt_event __user *event)
+{
+	struct vt_event_wait vw;
+
+	if (copy_from_user(&vw.event, event, sizeof(struct vt_event)))
+		return -EFAULT;
+	/* Highest supported event for now */
+	if (vw.event.event & ~VT_MAX_EVENT)
+		return -EINVAL;
+
+	vt_event_wait(&vw);
+	/* If it occurred report it */
+	if (vw.done) {
+		if (copy_to_user(event, &vw.event, sizeof(struct vt_event)))
+			return -EFAULT;
+		return 0;
+	}
+	return -EINTR;
+}
+
+/**
+ *	vt_waitactive	-	active console wait
+ *	@n: new console
+ *
+ *	Helper for event waits. Used to implement the legacy
+ *	event waiting ioctls in terms of events
+ */
+
+int vt_waitactive(int n)
+{
+	struct vt_event_wait vw;
+	do {
+		vw.event.event = VT_EVENT_SWITCH;
+		__vt_event_queue(&vw);
+		if (n == fg_console + 1) {
+			__vt_event_dequeue(&vw);
+			break;
+		}
+		__vt_event_wait(&vw);
+		__vt_event_dequeue(&vw);
+		if (vw.done == 0)
+			return -EINTR;
+	} while (vw.event.newev != n);
+	return 0;
+}
+
+/*
+ * 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)
+
+/*
+ * currently, setting the mode from KD_TEXT to KD_GRAPHICS doesn't do a whole
+ * lot. i'm not sure if it should do any restoration of modes or what...
+ *
+ * XXX It should at least call into the driver, fbdev's definitely need to
+ * restore their engine state. --BenH
+ *
+ * Called with the console lock held.
+ */
+static int vt_kdsetmode(struct vc_data *vc, unsigned long mode)
+{
+	switch (mode) {
+	case KD_GRAPHICS:
+		break;
+	case KD_TEXT0:
+	case KD_TEXT1:
+		mode = KD_TEXT;
+		fallthrough;
+	case KD_TEXT:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (vc->vc_mode == mode)
+		return 0;
+
+	vc->vc_mode = mode;
+	if (vc->vc_num != fg_console)
+		return 0;
+
+	/* explicitly blank/unblank the screen if switching modes */
+	if (mode == KD_TEXT)
+		do_unblank_screen(1);
+	else
+		do_blank_screen(1);
+
+	return 0;
+}
+
+static int vt_k_ioctl(struct tty_struct *tty, unsigned int cmd,
+		unsigned long arg, bool perm)
+{
+	struct vc_data *vc = tty->driver_data;
+	void __user *up = (void __user *)arg;
+	unsigned int console = vc->vc_num;
+	int ret;
+
+	switch (cmd) {
+	case KIOCSOUND:
+		if (!perm)
+			return -EPERM;
+		/*
+		 * The use of PIT_TICK_RATE is historic, it used to be
+		 * the platform-dependent CLOCK_TICK_RATE between 2.6.12
+		 * and 2.6.36, which was a minor but unfortunate ABI
+		 * change. kd_mksound is locked by the input layer.
+		 */
+		if (arg)
+			arg = PIT_TICK_RATE / arg;
+		kd_mksound(arg, 0);
+		break;
+
+	case KDMKTONE:
+		if (!perm)
+			return -EPERM;
+	{
+		unsigned int ticks, count;
+
+		/*
+		 * Generate the tone for the appropriate number of ticks.
+		 * If the time is zero, turn off sound ourselves.
+		 */
+		ticks = msecs_to_jiffies((arg >> 16) & 0xffff);
+		count = ticks ? (arg & 0xffff) : 0;
+		if (count)
+			count = PIT_TICK_RATE / count;
+		kd_mksound(count, ticks);
+		break;
+	}
+
+	case KDGKBTYPE:
+		/*
+		 * this is naïve.
+		 */
+		return put_user(KB_101, (char __user *)arg);
+
+		/*
+		 * These cannot be implemented on any machine that implements
+		 * ioperm() in user level (such as Alpha PCs) or not at all.
+		 *
+		 * XXX: you should never use these, just call ioperm directly..
+		 */
+#ifdef CONFIG_X86
+	case KDADDIO:
+	case KDDELIO:
+		/*
+		 * KDADDIO and KDDELIO may be able to add ports beyond what
+		 * we reject here, but to be safe...
+		 *
+		 * These are locked internally via sys_ioperm
+		 */
+		if (arg < GPFIRST || arg > GPLAST)
+			return -EINVAL;
+
+		return ksys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
+
+	case KDENABIO:
+	case KDDISABIO:
+		return ksys_ioperm(GPFIRST, GPNUM,
+				  (cmd == KDENABIO)) ? -ENXIO : 0;
+#endif
+
+	/* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
+
+	case KDKBDREP:
+	{
+		struct kbd_repeat kbrep;
+
+		if (!capable(CAP_SYS_TTY_CONFIG))
+			return -EPERM;
+
+		if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat)))
+			return -EFAULT;
+
+		ret = kbd_rate(&kbrep);
+		if (ret)
+			return ret;
+		if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
+			return -EFAULT;
+		break;
+	}
+
+	case KDSETMODE:
+		if (!perm)
+			return -EPERM;
+
+		console_lock();
+		ret = vt_kdsetmode(vc, arg);
+		console_unlock();
+		return ret;
+
+	case KDGETMODE:
+		return put_user(vc->vc_mode, (int __user *)arg);
+
+	case KDMAPDISP:
+	case KDUNMAPDISP:
+		/*
+		 * these work like a combination of mmap and KDENABIO.
+		 * this could be easily finished.
+		 */
+		return -EINVAL;
+
+	case KDSKBMODE:
+		if (!perm)
+			return -EPERM;
+		ret = vt_do_kdskbmode(console, arg);
+		if (ret)
+			return ret;
+		tty_ldisc_flush(tty);
+		break;
+
+	case KDGKBMODE:
+		return put_user(vt_do_kdgkbmode(console), (int __user *)arg);
+
+	/* this could be folded into KDSKBMODE, but for compatibility
+	   reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
+	case KDSKBMETA:
+		return vt_do_kdskbmeta(console, arg);
+
+	case KDGKBMETA:
+		/* FIXME: should review whether this is worth locking */
+		return put_user(vt_do_kdgkbmeta(console), (int __user *)arg);
+
+	case KDGETKEYCODE:
+	case KDSETKEYCODE:
+		if(!capable(CAP_SYS_TTY_CONFIG))
+			perm = 0;
+		return vt_do_kbkeycode_ioctl(cmd, up, perm);
+
+	case KDGKBENT:
+	case KDSKBENT:
+		return vt_do_kdsk_ioctl(cmd, up, perm, console);
+
+	case KDGKBSENT:
+	case KDSKBSENT:
+		return vt_do_kdgkb_ioctl(cmd, up, perm);
+
+	/* Diacritical processing. Handled in keyboard.c as it has
+	   to operate on the keyboard locks and structures */
+	case KDGKBDIACR:
+	case KDGKBDIACRUC:
+	case KDSKBDIACR:
+	case KDSKBDIACRUC:
+		return vt_do_diacrit(cmd, up, perm);
+
+	/* the ioctls below read/set the flags usually shown in the leds */
+	/* don't use them - they will go away without warning */
+	case KDGKBLED:
+	case KDSKBLED:
+	case KDGETLED:
+	case KDSETLED:
+		return vt_do_kdskled(console, cmd, arg, perm);
+
+	/*
+	 * A process can indicate its willingness to accept signals
+	 * generated by pressing an appropriate key combination.
+	 * Thus, one can have a daemon that e.g. spawns a new console
+	 * upon a keypress and then changes to it.
+	 * See also the kbrequest field of inittab(5).
+	 */
+	case KDSIGACCEPT:
+		if (!perm || !capable(CAP_KILL))
+			return -EPERM;
+		if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
+			return -EINVAL;
+
+		spin_lock_irq(&vt_spawn_con.lock);
+		put_pid(vt_spawn_con.pid);
+		vt_spawn_con.pid = get_pid(task_pid(current));
+		vt_spawn_con.sig = arg;
+		spin_unlock_irq(&vt_spawn_con.lock);
+		break;
+
+	case KDFONTOP: {
+		struct console_font_op op;
+
+		if (copy_from_user(&op, up, sizeof(op)))
+			return -EFAULT;
+		if (!perm && op.op != KD_FONT_OP_GET)
+			return -EPERM;
+		ret = con_font_op(vc, &op);
+		if (ret)
+			return ret;
+		if (copy_to_user(up, &op, sizeof(op)))
+			return -EFAULT;
+		break;
+	}
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+
+	return 0;
+}
+
+static inline int do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud,
+		bool perm, struct vc_data *vc)
+{
+	struct unimapdesc tmp;
+
+	if (copy_from_user(&tmp, user_ud, sizeof tmp))
+		return -EFAULT;
+	switch (cmd) {
+	case PIO_UNIMAP:
+		if (!perm)
+			return -EPERM;
+		return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
+	case GIO_UNIMAP:
+		if (!perm && fg_console != vc->vc_num)
+			return -EPERM;
+		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct),
+				tmp.entries);
+	}
+	return 0;
+}
+
+static int vt_io_ioctl(struct vc_data *vc, unsigned int cmd, void __user *up,
+		bool perm)
+{
+	switch (cmd) {
+	case PIO_CMAP:
+		if (!perm)
+			return -EPERM;
+		return con_set_cmap(up);
+
+	case GIO_CMAP:
+		return con_get_cmap(up);
+
+	case PIO_SCRNMAP:
+		if (!perm)
+			return -EPERM;
+		return con_set_trans_old(up);
+
+	case GIO_SCRNMAP:
+		return con_get_trans_old(up);
+
+	case PIO_UNISCRNMAP:
+		if (!perm)
+			return -EPERM;
+		return con_set_trans_new(up);
+
+	case GIO_UNISCRNMAP:
+		return con_get_trans_new(up);
+
+	case PIO_UNIMAPCLR:
+		if (!perm)
+			return -EPERM;
+		con_clear_unimap(vc);
+		break;
+
+	case PIO_UNIMAP:
+	case GIO_UNIMAP:
+		return do_unimap_ioctl(cmd, up, perm, vc);
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+
+	return 0;
+}
+
+static int vt_reldisp(struct vc_data *vc, unsigned int swtch)
+{
+	int newvt, ret;
+
+	if (vc->vt_mode.mode != VT_PROCESS)
+		return -EINVAL;
+
+	/* Switched-to response */
+	if (vc->vt_newvt < 0) {
+		 /* If it's just an ACK, ignore it */
+		return swtch == VT_ACKACQ ? 0 : -EINVAL;
+	}
+
+	/* Switching-from response */
+	if (swtch == 0) {
+		/* Switch disallowed, so forget we were trying to do it. */
+		vc->vt_newvt = -1;
+		return 0;
+	}
+
+	/* The current vt has been released, so complete the switch. */
+	newvt = vc->vt_newvt;
+	vc->vt_newvt = -1;
+	ret = vc_allocate(newvt);
+	if (ret)
+		return ret;
+
+	/*
+	 * When we actually do the console switch, make sure we are atomic with
+	 * respect to other console switches..
+	 */
+	complete_change_console(vc_cons[newvt].d);
+
+	return 0;
+}
+
+static int vt_setactivate(struct vt_setactivate __user *sa)
+{
+	struct vt_setactivate vsa;
+	struct vc_data *nvc;
+	int ret;
+
+	if (copy_from_user(&vsa, sa, sizeof(vsa)))
+		return -EFAULT;
+	if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES)
+		return -ENXIO;
+
+	vsa.console--;
+	vsa.console = array_index_nospec(vsa.console, MAX_NR_CONSOLES);
+	console_lock();
+	ret = vc_allocate(vsa.console);
+	if (ret) {
+		console_unlock();
+		return ret;
+	}
+
+	/*
+	 * This is safe providing we don't drop the console sem between
+	 * vc_allocate and finishing referencing nvc.
+	 */
+	nvc = vc_cons[vsa.console].d;
+	nvc->vt_mode = vsa.mode;
+	nvc->vt_mode.frsig = 0;
+	put_pid(nvc->vt_pid);
+	nvc->vt_pid = get_pid(task_pid(current));
+	console_unlock();
+
+	/* Commence switch and lock */
+	/* Review set_console locks */
+	set_console(vsa.console);
+
+	return 0;
+}
+
+/* deallocate a single console, if possible (leave 0) */
+static int vt_disallocate(unsigned int vc_num)
+{
+	struct vc_data *vc = NULL;
+	int ret = 0;
+
+	console_lock();
+	if (vt_busy(vc_num))
+		ret = -EBUSY;
+	else if (vc_num)
+		vc = vc_deallocate(vc_num);
+	console_unlock();
+
+	if (vc && vc_num >= MIN_NR_CONSOLES)
+		tty_port_put(&vc->port);
+
+	return ret;
+}
+
+/* deallocate all unused consoles, but leave 0 */
+static void vt_disallocate_all(void)
+{
+	struct vc_data *vc[MAX_NR_CONSOLES];
+	int i;
+
+	console_lock();
+	for (i = 1; i < MAX_NR_CONSOLES; i++)
+		if (!vt_busy(i))
+			vc[i] = vc_deallocate(i);
+		else
+			vc[i] = NULL;
+	console_unlock();
+
+	for (i = 1; i < MAX_NR_CONSOLES; i++) {
+		if (vc[i] && i >= MIN_NR_CONSOLES)
+			tty_port_put(&vc[i]->port);
+	}
+}
+
+static int vt_resizex(struct vc_data *vc, struct vt_consize __user *cs)
+{
+	struct vt_consize v;
+	int i;
+
+	if (copy_from_user(&v, cs, sizeof(struct vt_consize)))
+		return -EFAULT;
+
+	/* FIXME: Should check the copies properly */
+	if (!v.v_vlin)
+		v.v_vlin = vc->vc_scan_lines;
+
+	if (v.v_clin) {
+		int rows = v.v_vlin / v.v_clin;
+		if (v.v_rows != rows) {
+			if (v.v_rows) /* Parameters don't add up */
+				return -EINVAL;
+			v.v_rows = rows;
+		}
+	}
+
+	if (v.v_vcol && v.v_ccol) {
+		int cols = v.v_vcol / v.v_ccol;
+		if (v.v_cols != cols) {
+			if (v.v_cols)
+				return -EINVAL;
+			v.v_cols = cols;
+		}
+	}
+
+	if (v.v_clin > 32)
+		return -EINVAL;
+
+	for (i = 0; i < MAX_NR_CONSOLES; i++) {
+		struct vc_data *vcp;
+
+		if (!vc_cons[i].d)
+			continue;
+		console_lock();
+		vcp = vc_cons[i].d;
+		if (vcp) {
+			int ret;
+			int save_scan_lines = vcp->vc_scan_lines;
+			int save_cell_height = vcp->vc_cell_height;
+
+			if (v.v_vlin)
+				vcp->vc_scan_lines = v.v_vlin;
+			if (v.v_clin)
+				vcp->vc_cell_height = v.v_clin;
+			vcp->vc_resize_user = 1;
+			ret = vc_resize(vcp, v.v_cols, v.v_rows);
+			if (ret) {
+				vcp->vc_scan_lines = save_scan_lines;
+				vcp->vc_cell_height = save_cell_height;
+				console_unlock();
+				return ret;
+			}
+		}
+		console_unlock();
+	}
+
+	return 0;
+}
+
+/*
+ * We handle the console-specific ioctl's here.  We allow the
+ * capability to modify any console, not just the fg_console.
+ */
+int vt_ioctl(struct tty_struct *tty,
+	     unsigned int cmd, unsigned long arg)
+{
+	struct vc_data *vc = tty->driver_data;
+	void __user *up = (void __user *)arg;
+	int i, perm;
+	int ret;
+
+	/*
+	 * To have permissions to do most of the vt ioctls, we either have
+	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
+	 */
+	perm = 0;
+	if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
+		perm = 1;
+
+	ret = vt_k_ioctl(tty, cmd, arg, perm);
+	if (ret != -ENOIOCTLCMD)
+		return ret;
+
+	ret = vt_io_ioctl(vc, cmd, up, perm);
+	if (ret != -ENOIOCTLCMD)
+		return ret;
+
+	switch (cmd) {
+	case TIOCLINUX:
+		return tioclinux(tty, arg);
+	case VT_SETMODE:
+	{
+		struct vt_mode tmp;
+
+		if (!perm)
+			return -EPERM;
+		if (copy_from_user(&tmp, up, sizeof(struct vt_mode)))
+			return -EFAULT;
+		if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS)
+			return -EINVAL;
+
+		console_lock();
+		vc->vt_mode = tmp;
+		/* the frsig is ignored, so we set it to 0 */
+		vc->vt_mode.frsig = 0;
+		put_pid(vc->vt_pid);
+		vc->vt_pid = get_pid(task_pid(current));
+		/* no switch is required -- saw@shade.msu.ru */
+		vc->vt_newvt = -1;
+		console_unlock();
+		break;
+	}
+
+	case VT_GETMODE:
+	{
+		struct vt_mode tmp;
+		int rc;
+
+		console_lock();
+		memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
+		console_unlock();
+
+		rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
+		if (rc)
+			return -EFAULT;
+		break;
+	}
+
+	/*
+	 * Returns global vt state. Note that VT 0 is always open, since
+	 * it's an alias for the current VT, and people can't use it here.
+	 * We cannot return state for more than 16 VTs, since v_state is short.
+	 */
+	case VT_GETSTATE:
+	{
+		struct vt_stat __user *vtstat = up;
+		unsigned short state, mask;
+
+		if (put_user(fg_console + 1, &vtstat->v_active))
+			return -EFAULT;
+
+		state = 1;	/* /dev/tty0 is always open */
+		console_lock(); /* required by vt_in_use() */
+		for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
+				++i, mask <<= 1)
+			if (vt_in_use(i))
+				state |= mask;
+		console_unlock();
+		return put_user(state, &vtstat->v_state);
+	}
+
+	/*
+	 * Returns the first available (non-opened) console.
+	 */
+	case VT_OPENQRY:
+		console_lock(); /* required by vt_in_use() */
+		for (i = 0; i < MAX_NR_CONSOLES; ++i)
+			if (!vt_in_use(i))
+				break;
+		console_unlock();
+		i = i < MAX_NR_CONSOLES ? (i+1) : -1;
+		return put_user(i, (int __user *)arg);
+
+	/*
+	 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
+	 * with num >= 1 (switches to vt 0, our console, are not allowed, just
+	 * to preserve sanity).
+	 */
+	case VT_ACTIVATE:
+		if (!perm)
+			return -EPERM;
+		if (arg == 0 || arg > MAX_NR_CONSOLES)
+			return -ENXIO;
+
+		arg--;
+		arg = array_index_nospec(arg, MAX_NR_CONSOLES);
+		console_lock();
+		ret = vc_allocate(arg);
+		console_unlock();
+		if (ret)
+			return ret;
+		set_console(arg);
+		break;
+
+	case VT_SETACTIVATE:
+		if (!perm)
+			return -EPERM;
+
+		return vt_setactivate(up);
+
+	/*
+	 * wait until the specified VT has been activated
+	 */
+	case VT_WAITACTIVE:
+		if (!perm)
+			return -EPERM;
+		if (arg == 0 || arg > MAX_NR_CONSOLES)
+			return -ENXIO;
+		return vt_waitactive(arg);
+
+	/*
+	 * If a vt is under process control, the kernel will not switch to it
+	 * immediately, but postpone the operation until the process calls this
+	 * ioctl, allowing the switch to complete.
+	 *
+	 * According to the X sources this is the behavior:
+	 *	0:	pending switch-from not OK
+	 *	1:	pending switch-from OK
+	 *	2:	completed switch-to OK
+	 */
+	case VT_RELDISP:
+		if (!perm)
+			return -EPERM;
+
+		console_lock();
+		ret = vt_reldisp(vc, arg);
+		console_unlock();
+
+		return ret;
+
+
+	 /*
+	  * Disallocate memory associated to VT (but leave VT1)
+	  */
+	 case VT_DISALLOCATE:
+		if (arg > MAX_NR_CONSOLES)
+			return -ENXIO;
+
+		if (arg == 0) {
+			vt_disallocate_all();
+			break;
+		}
+
+		arg = array_index_nospec(arg - 1, MAX_NR_CONSOLES);
+		return vt_disallocate(arg);
+
+	case VT_RESIZE:
+	{
+		struct vt_sizes __user *vtsizes = up;
+		struct vc_data *vc;
+		ushort ll,cc;
+
+		if (!perm)
+			return -EPERM;
+		if (get_user(ll, &vtsizes->v_rows) ||
+		    get_user(cc, &vtsizes->v_cols))
+			return -EFAULT;
+
+		console_lock();
+		for (i = 0; i < MAX_NR_CONSOLES; i++) {
+			vc = vc_cons[i].d;
+
+			if (vc) {
+				vc->vc_resize_user = 1;
+				/* FIXME: review v tty lock */
+				vc_resize(vc_cons[i].d, cc, ll);
+			}
+		}
+		console_unlock();
+		break;
+	}
+
+	case VT_RESIZEX:
+		if (!perm)
+			return -EPERM;
+
+		return vt_resizex(vc, up);
+
+	case VT_LOCKSWITCH:
+		if (!capable(CAP_SYS_TTY_CONFIG))
+			return -EPERM;
+		vt_dont_switch = true;
+		break;
+	case VT_UNLOCKSWITCH:
+		if (!capable(CAP_SYS_TTY_CONFIG))
+			return -EPERM;
+		vt_dont_switch = false;
+		break;
+	case VT_GETHIFONTMASK:
+		return put_user(vc->vc_hi_font_mask,
+					(unsigned short __user *)arg);
+	case VT_WAITEVENT:
+		return vt_event_wait_ioctl((struct vt_event __user *)arg);
+	default:
+		return -ENOIOCTLCMD;
+	}
+
+	return 0;
+}
+
+void reset_vc(struct vc_data *vc)
+{
+	vc->vc_mode = KD_TEXT;
+	vt_reset_unicode(vc->vc_num);
+	vc->vt_mode.mode = VT_AUTO;
+	vc->vt_mode.waitv = 0;
+	vc->vt_mode.relsig = 0;
+	vc->vt_mode.acqsig = 0;
+	vc->vt_mode.frsig = 0;
+	put_pid(vc->vt_pid);
+	vc->vt_pid = NULL;
+	vc->vt_newvt = -1;
+	reset_palette(vc);
+}
+
+void vc_SAK(struct work_struct *work)
+{
+	struct vc *vc_con =
+		container_of(work, struct vc, SAK_work);
+	struct vc_data *vc;
+	struct tty_struct *tty;
+
+	console_lock();
+	vc = vc_con->d;
+	if (vc) {
+		/* FIXME: review tty ref counting */
+		tty = vc->port.tty;
+		/*
+		 * SAK should also work in all raw modes and reset
+		 * them properly.
+		 */
+		if (tty)
+			__do_SAK(tty);
+		reset_vc(vc);
+	}
+	console_unlock();
+}
+
+#ifdef CONFIG_COMPAT
+
+struct compat_console_font_op {
+	compat_uint_t op;        /* operation code KD_FONT_OP_* */
+	compat_uint_t flags;     /* KD_FONT_FLAG_* */
+	compat_uint_t width, height;     /* font size */
+	compat_uint_t charcount;
+	compat_caddr_t data;    /* font data with height fixed to 32 */
+};
+
+static inline int
+compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop,
+			 int perm, struct console_font_op *op, struct vc_data *vc)
+{
+	int i;
+
+	if (copy_from_user(op, fontop, sizeof(struct compat_console_font_op)))
+		return -EFAULT;
+	if (!perm && op->op != KD_FONT_OP_GET)
+		return -EPERM;
+	op->data = compat_ptr(((struct compat_console_font_op *)op)->data);
+	i = con_font_op(vc, op);
+	if (i)
+		return i;
+	((struct compat_console_font_op *)op)->data = (unsigned long)op->data;
+	if (copy_to_user(fontop, op, sizeof(struct compat_console_font_op)))
+		return -EFAULT;
+	return 0;
+}
+
+struct compat_unimapdesc {
+	unsigned short entry_ct;
+	compat_caddr_t entries;
+};
+
+static inline int
+compat_unimap_ioctl(unsigned int cmd, struct compat_unimapdesc __user *user_ud,
+			 int perm, struct vc_data *vc)
+{
+	struct compat_unimapdesc tmp;
+	struct unipair __user *tmp_entries;
+
+	if (copy_from_user(&tmp, user_ud, sizeof tmp))
+		return -EFAULT;
+	tmp_entries = compat_ptr(tmp.entries);
+	switch (cmd) {
+	case PIO_UNIMAP:
+		if (!perm)
+			return -EPERM;
+		return con_set_unimap(vc, tmp.entry_ct, tmp_entries);
+	case GIO_UNIMAP:
+		if (!perm && fg_console != vc->vc_num)
+			return -EPERM;
+		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp_entries);
+	}
+	return 0;
+}
+
+long vt_compat_ioctl(struct tty_struct *tty,
+	     unsigned int cmd, unsigned long arg)
+{
+	struct vc_data *vc = tty->driver_data;
+	struct console_font_op op;	/* used in multiple places here */
+	void __user *up = compat_ptr(arg);
+	int perm;
+
+	/*
+	 * To have permissions to do most of the vt ioctls, we either have
+	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
+	 */
+	perm = 0;
+	if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
+		perm = 1;
+
+	switch (cmd) {
+	/*
+	 * these need special handlers for incompatible data structures
+	 */
+
+	case KDFONTOP:
+		return compat_kdfontop_ioctl(up, perm, &op, vc);
+
+	case PIO_UNIMAP:
+	case GIO_UNIMAP:
+		return compat_unimap_ioctl(cmd, up, perm, vc);
+
+	/*
+	 * all these treat 'arg' as an integer
+	 */
+	case KIOCSOUND:
+	case KDMKTONE:
+#ifdef CONFIG_X86
+	case KDADDIO:
+	case KDDELIO:
+#endif
+	case KDSETMODE:
+	case KDMAPDISP:
+	case KDUNMAPDISP:
+	case KDSKBMODE:
+	case KDSKBMETA:
+	case KDSKBLED:
+	case KDSETLED:
+	case KDSIGACCEPT:
+	case VT_ACTIVATE:
+	case VT_WAITACTIVE:
+	case VT_RELDISP:
+	case VT_DISALLOCATE:
+	case VT_RESIZE:
+	case VT_RESIZEX:
+		return vt_ioctl(tty, cmd, arg);
+
+	/*
+	 * the rest has a compatible data structure behind arg,
+	 * but we have to convert it to a proper 64 bit pointer.
+	 */
+	default:
+		return vt_ioctl(tty, cmd, (unsigned long)up);
+	}
+}
+
+
+#endif /* CONFIG_COMPAT */
+
+
+/*
+ * Performs the back end of a vt switch. Called under the console
+ * semaphore.
+ */
+static void complete_change_console(struct vc_data *vc)
+{
+	unsigned char old_vc_mode;
+	int old = fg_console;
+
+	last_console = fg_console;
+
+	/*
+	 * If we're switching, we could be going from KD_GRAPHICS to
+	 * KD_TEXT mode or vice versa, which means we need to blank or
+	 * unblank the screen later.
+	 */
+	old_vc_mode = vc_cons[fg_console].d->vc_mode;
+	switch_screen(vc);
+
+	/*
+	 * This can't appear below a successful kill_pid().  If it did,
+	 * then the *blank_screen operation could occur while X, having
+	 * received acqsig, is waking up on another processor.  This
+	 * condition can lead to overlapping accesses to the VGA range
+	 * and the framebuffer (causing system lockups).
+	 *
+	 * To account for this we duplicate this code below only if the
+	 * controlling process is gone and we've called reset_vc.
+	 */
+	if (old_vc_mode != vc->vc_mode) {
+		if (vc->vc_mode == KD_TEXT)
+			do_unblank_screen(1);
+		else
+			do_blank_screen(1);
+	}
+
+	/*
+	 * If this new console is under process control, send it a signal
+	 * telling it that it has acquired. Also check if it has died and
+	 * clean up (similar to logic employed in change_console())
+	 */
+	if (vc->vt_mode.mode == VT_PROCESS) {
+		/*
+		 * Send the signal as privileged - kill_pid() will
+		 * tell us if the process has gone or something else
+		 * is awry
+		 */
+		if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
+		/*
+		 * The controlling process has died, so we revert back to
+		 * normal operation. In this case, we'll also change back
+		 * to KD_TEXT mode. I'm not sure if this is strictly correct
+		 * but it saves the agony when the X server dies and the screen
+		 * remains blanked due to KD_GRAPHICS! It would be nice to do
+		 * this outside of VT_PROCESS but there is no single process
+		 * to account for and tracking tty count may be undesirable.
+		 */
+			reset_vc(vc);
+
+			if (old_vc_mode != vc->vc_mode) {
+				if (vc->vc_mode == KD_TEXT)
+					do_unblank_screen(1);
+				else
+					do_blank_screen(1);
+			}
+		}
+	}
+
+	/*
+	 * Wake anyone waiting for their VT to activate
+	 */
+	vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num);
+	return;
+}
+
+/*
+ * Performs the front-end of a vt switch
+ */
+void change_console(struct vc_data *new_vc)
+{
+	struct vc_data *vc;
+
+	if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
+		return;
+
+	/*
+	 * If this vt is in process mode, then we need to handshake with
+	 * that process before switching. Essentially, we store where that
+	 * vt wants to switch to and wait for it to tell us when it's done
+	 * (via VT_RELDISP ioctl).
+	 *
+	 * We also check to see if the controlling process still exists.
+	 * If it doesn't, we reset this vt to auto mode and continue.
+	 * This is a cheap way to track process control. The worst thing
+	 * that can happen is: we send a signal to a process, it dies, and
+	 * the switch gets "lost" waiting for a response; hopefully, the
+	 * user will try again, we'll detect the process is gone (unless
+	 * the user waits just the right amount of time :-) and revert the
+	 * vt to auto control.
+	 */
+	vc = vc_cons[fg_console].d;
+	if (vc->vt_mode.mode == VT_PROCESS) {
+		/*
+		 * Send the signal as privileged - kill_pid() will
+		 * tell us if the process has gone or something else
+		 * is awry.
+		 *
+		 * We need to set vt_newvt *before* sending the signal or we
+		 * have a race.
+		 */
+		vc->vt_newvt = new_vc->vc_num;
+		if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
+			/*
+			 * It worked. Mark the vt to switch to and
+			 * return. The process needs to send us a
+			 * VT_RELDISP ioctl to complete the switch.
+			 */
+			return;
+		}
+
+		/*
+		 * The controlling process has died, so we revert back to
+		 * normal operation. In this case, we'll also change back
+		 * to KD_TEXT mode. I'm not sure if this is strictly correct
+		 * but it saves the agony when the X server dies and the screen
+		 * remains blanked due to KD_GRAPHICS! It would be nice to do
+		 * this outside of VT_PROCESS but there is no single process
+		 * to account for and tracking tty count may be undesirable.
+		 */
+		reset_vc(vc);
+
+		/*
+		 * Fall through to normal (VT_AUTO) handling of the switch...
+		 */
+	}
+
+	/*
+	 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
+	 */
+	if (vc->vc_mode == KD_GRAPHICS)
+		return;
+
+	complete_change_console(new_vc);
+}
+
+/* Perform a kernel triggered VT switch for suspend/resume */
+
+static int disable_vt_switch;
+
+int vt_move_to_console(unsigned int vt, int alloc)
+{
+	int prev;
+
+	console_lock();
+	/* Graphics mode - up to X */
+	if (disable_vt_switch) {
+		console_unlock();
+		return 0;
+	}
+	prev = fg_console;
+
+	if (alloc && vc_allocate(vt)) {
+		/* we can't have a free VC for now. Too bad,
+		 * we don't want to mess the screen for now. */
+		console_unlock();
+		return -ENOSPC;
+	}
+
+	if (set_console(vt)) {
+		/*
+		 * We're unable to switch to the SUSPEND_CONSOLE.
+		 * Let the calling function know so it can decide
+		 * what to do.
+		 */
+		console_unlock();
+		return -EIO;
+	}
+	console_unlock();
+	if (vt_waitactive(vt + 1)) {
+		pr_debug("Suspend: Can't switch VCs.");
+		return -EINTR;
+	}
+	return prev;
+}
+
+/*
+ * Normally during a suspend, we allocate a new console and switch to it.
+ * When we resume, we switch back to the original console.  This switch
+ * can be slow, so on systems where the framebuffer can handle restoration
+ * of video registers anyways, there's little point in doing the console
+ * switch.  This function allows you to disable it by passing it '0'.
+ */
+void pm_set_vt_switch(int do_switch)
+{
+	console_lock();
+	disable_vt_switch = !do_switch;
+	console_unlock();
+}
+EXPORT_SYMBOL(pm_set_vt_switch);