TTY: create drivers/tty/vt and move the vt code there

The vt and other related code is moved into the drivers/tty/vt directory.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 644 insertions, 0 deletions

diff --git a/drivers/tty/vt/vc_screen.c b/drivers/tty/vt/vc_screen.c
new file mode 100644
index 00000000000..273ab44cc91
--- /dev/null
+++ b/drivers/tty/vt/vc_screen.c
@@ -0,0 +1,644 @@
+/*
+ * linux/drivers/char/vc_screen.c
+ *
+ * Provide access to virtual console memory.
+ * /dev/vcs0: the screen as it is being viewed right now (possibly scrolled)
+ * /dev/vcsN: the screen of /dev/ttyN (1 <= N <= 63)
+ *            [minor: N]
+ *
+ * /dev/vcsaN: idem, but including attributes, and prefixed with
+ *	the 4 bytes lines,columns,x,y (as screendump used to give).
+ *	Attribute/character pair is in native endianity.
+ *            [minor: N+128]
+ *
+ * This replaces screendump and part of selection, so that the system
+ * administrator can control access using file system permissions.
+ *
+ * aeb@cwi.nl - efter Friedas begravelse - 950211
+ *
+ * machek@k332.feld.cvut.cz - modified not to send characters to wrong console
+ *	 - fixed some fatal off-by-one bugs (0-- no longer == -1 -> looping and looping and looping...)
+ *	 - making it shorter - scr_readw are macros which expand in PRETTY long code
+ */
+
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/errno.h>
+#include <linux/tty.h>
+#include <linux/interrupt.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/vt_kern.h>
+#include <linux/selection.h>
+#include <linux/kbd_kern.h>
+#include <linux/console.h>
+#include <linux/device.h>
+#include <linux/smp_lock.h>
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <linux/signal.h>
+#include <linux/slab.h>
+#include <linux/notifier.h>
+
+#include <asm/uaccess.h>
+#include <asm/byteorder.h>
+#include <asm/unaligned.h>
+
+#undef attr
+#undef org
+#undef addr
+#define HEADER_SIZE	4
+
+struct vcs_poll_data {
+	struct notifier_block notifier;
+	unsigned int cons_num;
+	bool seen_last_update;
+	wait_queue_head_t waitq;
+	struct fasync_struct *fasync;
+};
+
+static int
+vcs_notifier(struct notifier_block *nb, unsigned long code, void *_param)
+{
+	struct vt_notifier_param *param = _param;
+	struct vc_data *vc = param->vc;
+	struct vcs_poll_data *poll =
+		container_of(nb, struct vcs_poll_data, notifier);
+	int currcons = poll->cons_num;
+
+	if (code != VT_UPDATE)
+		return NOTIFY_DONE;
+
+	if (currcons == 0)
+		currcons = fg_console;
+	else
+		currcons--;
+	if (currcons != vc->vc_num)
+		return NOTIFY_DONE;
+
+	poll->seen_last_update = false;
+	wake_up_interruptible(&poll->waitq);
+	kill_fasync(&poll->fasync, SIGIO, POLL_IN);
+	return NOTIFY_OK;
+}
+
+static void
+vcs_poll_data_free(struct vcs_poll_data *poll)
+{
+	unregister_vt_notifier(&poll->notifier);
+	kfree(poll);
+}
+
+static struct vcs_poll_data *
+vcs_poll_data_get(struct file *file)
+{
+	struct vcs_poll_data *poll = file->private_data;
+
+	if (poll)
+		return poll;
+
+	poll = kzalloc(sizeof(*poll), GFP_KERNEL);
+	if (!poll)
+		return NULL;
+	poll->cons_num = iminor(file->f_path.dentry->d_inode) & 127;
+	init_waitqueue_head(&poll->waitq);
+	poll->notifier.notifier_call = vcs_notifier;
+	if (register_vt_notifier(&poll->notifier) != 0) {
+		kfree(poll);
+		return NULL;
+	}
+
+	/*
+	 * This code may be called either through ->poll() or ->fasync().
+	 * If we have two threads using the same file descriptor, they could
+	 * both enter this function, both notice that the structure hasn't
+	 * been allocated yet and go ahead allocating it in parallel, but
+	 * only one of them must survive and be shared otherwise we'd leak
+	 * memory with a dangling notifier callback.
+	 */
+	spin_lock(&file->f_lock);
+	if (!file->private_data) {
+		file->private_data = poll;
+	} else {
+		/* someone else raced ahead of us */
+		vcs_poll_data_free(poll);
+		poll = file->private_data;
+	}
+	spin_unlock(&file->f_lock);
+
+	return poll;
+}
+
+static int
+vcs_size(struct inode *inode)
+{
+	int size;
+	int minor = iminor(inode);
+	int currcons = minor & 127;
+	struct vc_data *vc;
+
+	if (currcons == 0)
+		currcons = fg_console;
+	else
+		currcons--;
+	if (!vc_cons_allocated(currcons))
+		return -ENXIO;
+	vc = vc_cons[currcons].d;
+
+	size = vc->vc_rows * vc->vc_cols;
+
+	if (minor & 128)
+		size = 2*size + HEADER_SIZE;
+	return size;
+}
+
+static loff_t vcs_lseek(struct file *file, loff_t offset, int orig)
+{
+	int size;
+
+	mutex_lock(&con_buf_mtx);
+	size = vcs_size(file->f_path.dentry->d_inode);
+	switch (orig) {
+		default:
+			mutex_unlock(&con_buf_mtx);
+			return -EINVAL;
+		case 2:
+			offset += size;
+			break;
+		case 1:
+			offset += file->f_pos;
+		case 0:
+			break;
+	}
+	if (offset < 0 || offset > size) {
+		mutex_unlock(&con_buf_mtx);
+		return -EINVAL;
+	}
+	file->f_pos = offset;
+	mutex_unlock(&con_buf_mtx);
+	return file->f_pos;
+}
+
+
+static ssize_t
+vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+	struct inode *inode = file->f_path.dentry->d_inode;
+	unsigned int currcons = iminor(inode);
+	struct vc_data *vc;
+	struct vcs_poll_data *poll;
+	long pos;
+	long viewed, attr, read;
+	int col, maxcol;
+	unsigned short *org = NULL;
+	ssize_t ret;
+
+	mutex_lock(&con_buf_mtx);
+
+	pos = *ppos;
+
+	/* Select the proper current console and verify
+	 * sanity of the situation under the console lock.
+	 */
+	acquire_console_sem();
+
+	attr = (currcons & 128);
+	currcons = (currcons & 127);
+	if (currcons == 0) {
+		currcons = fg_console;
+		viewed = 1;
+	} else {
+		currcons--;
+		viewed = 0;
+	}
+	ret = -ENXIO;
+	if (!vc_cons_allocated(currcons))
+		goto unlock_out;
+	vc = vc_cons[currcons].d;
+
+	ret = -EINVAL;
+	if (pos < 0)
+		goto unlock_out;
+	poll = file->private_data;
+	if (count && poll)
+		poll->seen_last_update = true;
+	read = 0;
+	ret = 0;
+	while (count) {
+		char *con_buf0, *con_buf_start;
+		long this_round, size;
+		ssize_t orig_count;
+		long p = pos;
+
+		/* Check whether we are above size each round,
+		 * as copy_to_user at the end of this loop
+		 * could sleep.
+		 */
+		size = vcs_size(inode);
+		if (pos >= size)
+			break;
+		if (count > size - pos)
+			count = size - pos;
+
+		this_round = count;
+		if (this_round > CON_BUF_SIZE)
+			this_round = CON_BUF_SIZE;
+
+		/* Perform the whole read into the local con_buf.
+		 * Then we can drop the console spinlock and safely
+		 * attempt to move it to userspace.
+		 */
+
+		con_buf_start = con_buf0 = con_buf;
+		orig_count = this_round;
+		maxcol = vc->vc_cols;
+		if (!attr) {
+			org = screen_pos(vc, p, viewed);
+			col = p % maxcol;
+			p += maxcol - col;
+			while (this_round-- > 0) {
+				*con_buf0++ = (vcs_scr_readw(vc, org++) & 0xff);
+				if (++col == maxcol) {
+					org = screen_pos(vc, p, viewed);
+					col = 0;
+					p += maxcol;
+				}
+			}
+		} else {
+			if (p < HEADER_SIZE) {
+				size_t tmp_count;
+
+				con_buf0[0] = (char)vc->vc_rows;
+				con_buf0[1] = (char)vc->vc_cols;
+				getconsxy(vc, con_buf0 + 2);
+
+				con_buf_start += p;
+				this_round += p;
+				if (this_round > CON_BUF_SIZE) {
+					this_round = CON_BUF_SIZE;
+					orig_count = this_round - p;
+				}
+
+				tmp_count = HEADER_SIZE;
+				if (tmp_count > this_round)
+					tmp_count = this_round;
+
+				/* Advance state pointers and move on. */
+				this_round -= tmp_count;
+				p = HEADER_SIZE;
+				con_buf0 = con_buf + HEADER_SIZE;
+				/* If this_round >= 0, then p is even... */
+			} else if (p & 1) {
+				/* Skip first byte for output if start address is odd
+				 * Update region sizes up/down depending on free
+				 * space in buffer.
+				 */
+				con_buf_start++;
+				if (this_round < CON_BUF_SIZE)
+					this_round++;
+				else
+					orig_count--;
+			}
+			if (this_round > 0) {
+				unsigned short *tmp_buf = (unsigned short *)con_buf0;
+
+				p -= HEADER_SIZE;
+				p /= 2;
+				col = p % maxcol;
+
+				org = screen_pos(vc, p, viewed);
+				p += maxcol - col;
+
+				/* Buffer has even length, so we can always copy
+				 * character + attribute. We do not copy last byte
+				 * to userspace if this_round is odd.
+				 */
+				this_round = (this_round + 1) >> 1;
+
+				while (this_round) {
+					*tmp_buf++ = vcs_scr_readw(vc, org++);
+					this_round --;
+					if (++col == maxcol) {
+						org = screen_pos(vc, p, viewed);
+						col = 0;
+						p += maxcol;
+					}
+				}
+			}
+		}
+
+		/* Finally, release the console semaphore while we push
+		 * all the data to userspace from our temporary buffer.
+		 *
+		 * AKPM: Even though it's a semaphore, we should drop it because
+		 * the pagefault handling code may want to call printk().
+		 */
+
+		release_console_sem();
+		ret = copy_to_user(buf, con_buf_start, orig_count);
+		acquire_console_sem();
+
+		if (ret) {
+			read += (orig_count - ret);
+			ret = -EFAULT;
+			break;
+		}
+		buf += orig_count;
+		pos += orig_count;
+		read += orig_count;
+		count -= orig_count;
+	}
+	*ppos += read;
+	if (read)
+		ret = read;
+unlock_out:
+	release_console_sem();
+	mutex_unlock(&con_buf_mtx);
+	return ret;
+}
+
+static ssize_t
+vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
+{
+	struct inode *inode = file->f_path.dentry->d_inode;
+	unsigned int currcons = iminor(inode);
+	struct vc_data *vc;
+	long pos;
+	long viewed, attr, size, written;
+	char *con_buf0;
+	int col, maxcol;
+	u16 *org0 = NULL, *org = NULL;
+	size_t ret;
+
+	mutex_lock(&con_buf_mtx);
+
+	pos = *ppos;
+
+	/* Select the proper current console and verify
+	 * sanity of the situation under the console lock.
+	 */
+	acquire_console_sem();
+
+	attr = (currcons & 128);
+	currcons = (currcons & 127);
+
+	if (currcons == 0) {
+		currcons = fg_console;
+		viewed = 1;
+	} else {
+		currcons--;
+		viewed = 0;
+	}
+	ret = -ENXIO;
+	if (!vc_cons_allocated(currcons))
+		goto unlock_out;
+	vc = vc_cons[currcons].d;
+
+	size = vcs_size(inode);
+	ret = -EINVAL;
+	if (pos < 0 || pos > size)
+		goto unlock_out;
+	if (count > size - pos)
+		count = size - pos;
+	written = 0;
+	while (count) {
+		long this_round = count;
+		size_t orig_count;
+		long p;
+
+		if (this_round > CON_BUF_SIZE)
+			this_round = CON_BUF_SIZE;
+
+		/* Temporarily drop the console lock so that we can read
+		 * in the write data from userspace safely.
+		 */
+		release_console_sem();
+		ret = copy_from_user(con_buf, buf, this_round);
+		acquire_console_sem();
+
+		if (ret) {
+			this_round -= ret;
+			if (!this_round) {
+				/* Abort loop if no data were copied. Otherwise
+				 * fail with -EFAULT.
+				 */
+				if (written)
+					break;
+				ret = -EFAULT;
+				goto unlock_out;
+			}
+		}
+
+		/* The vcs_size might have changed while we slept to grab
+		 * the user buffer, so recheck.
+		 * Return data written up to now on failure.
+		 */
+		size = vcs_size(inode);
+		if (pos >= size)
+			break;
+		if (this_round > size - pos)
+			this_round = size - pos;
+
+		/* OK, now actually push the write to the console
+		 * under the lock using the local kernel buffer.
+		 */
+
+		con_buf0 = con_buf;
+		orig_count = this_round;
+		maxcol = vc->vc_cols;
+		p = pos;
+		if (!attr) {
+			org0 = org = screen_pos(vc, p, viewed);
+			col = p % maxcol;
+			p += maxcol - col;
+
+			while (this_round > 0) {
+				unsigned char c = *con_buf0++;
+
+				this_round--;
+				vcs_scr_writew(vc,
+					       (vcs_scr_readw(vc, org) & 0xff00) | c, org);
+				org++;
+				if (++col == maxcol) {
+					org = screen_pos(vc, p, viewed);
+					col = 0;
+					p += maxcol;
+				}
+			}
+		} else {
+			if (p < HEADER_SIZE) {
+				char header[HEADER_SIZE];
+
+				getconsxy(vc, header + 2);
+				while (p < HEADER_SIZE && this_round > 0) {
+					this_round--;
+					header[p++] = *con_buf0++;
+				}
+				if (!viewed)
+					putconsxy(vc, header + 2);
+			}
+			p -= HEADER_SIZE;
+			col = (p/2) % maxcol;
+			if (this_round > 0) {
+				org0 = org = screen_pos(vc, p/2, viewed);
+				if ((p & 1) && this_round > 0) {
+					char c;
+
+					this_round--;
+					c = *con_buf0++;
+#ifdef __BIG_ENDIAN
+					vcs_scr_writew(vc, c |
+					     (vcs_scr_readw(vc, org) & 0xff00), org);
+#else
+					vcs_scr_writew(vc, (c << 8) |
+					     (vcs_scr_readw(vc, org) & 0xff), org);
+#endif
+					org++;
+					p++;
+					if (++col == maxcol) {
+						org = screen_pos(vc, p/2, viewed);
+						col = 0;
+					}
+				}
+				p /= 2;
+				p += maxcol - col;
+			}
+			while (this_round > 1) {
+				unsigned short w;
+
+				w = get_unaligned(((unsigned short *)con_buf0));
+				vcs_scr_writew(vc, w, org++);
+				con_buf0 += 2;
+				this_round -= 2;
+				if (++col == maxcol) {
+					org = screen_pos(vc, p, viewed);
+					col = 0;
+					p += maxcol;
+				}
+			}
+			if (this_round > 0) {
+				unsigned char c;
+
+				c = *con_buf0++;
+#ifdef __BIG_ENDIAN
+				vcs_scr_writew(vc, (vcs_scr_readw(vc, org) & 0xff) | (c << 8), org);
+#else
+				vcs_scr_writew(vc, (vcs_scr_readw(vc, org) & 0xff00) | c, org);
+#endif
+			}
+		}
+		count -= orig_count;
+		written += orig_count;
+		buf += orig_count;
+		pos += orig_count;
+		if (org0)
+			update_region(vc, (unsigned long)(org0), org - org0);
+	}
+	*ppos += written;
+	ret = written;
+	if (written)
+		vcs_scr_updated(vc);
+
+unlock_out:
+	release_console_sem();
+
+	mutex_unlock(&con_buf_mtx);
+
+	return ret;
+}
+
+static unsigned int
+vcs_poll(struct file *file, poll_table *wait)
+{
+	struct vcs_poll_data *poll = vcs_poll_data_get(file);
+	int ret = 0;
+
+	if (poll) {
+		poll_wait(file, &poll->waitq, wait);
+		if (!poll->seen_last_update)
+			ret = POLLIN | POLLRDNORM;
+	}
+	return ret;
+}
+
+static int
+vcs_fasync(int fd, struct file *file, int on)
+{
+	struct vcs_poll_data *poll = file->private_data;
+
+	if (!poll) {
+		/* don't allocate anything if all we want is disable fasync */
+		if (!on)
+			return 0;
+		poll = vcs_poll_data_get(file);
+		if (!poll)
+			return -ENOMEM;
+	}
+
+	return fasync_helper(fd, file, on, &poll->fasync);
+}
+
+static int
+vcs_open(struct inode *inode, struct file *filp)
+{
+	unsigned int currcons = iminor(inode) & 127;
+	int ret = 0;
+	
+	tty_lock();
+	if(currcons && !vc_cons_allocated(currcons-1))
+		ret = -ENXIO;
+	tty_unlock();
+	return ret;
+}
+
+static int vcs_release(struct inode *inode, struct file *file)
+{
+	struct vcs_poll_data *poll = file->private_data;
+
+	if (poll)
+		vcs_poll_data_free(poll);
+	return 0;
+}
+
+static const struct file_operations vcs_fops = {
+	.llseek		= vcs_lseek,
+	.read		= vcs_read,
+	.write		= vcs_write,
+	.poll		= vcs_poll,
+	.fasync		= vcs_fasync,
+	.open		= vcs_open,
+	.release	= vcs_release,
+};
+
+static struct class *vc_class;
+
+void vcs_make_sysfs(int index)
+{
+	device_create(vc_class, NULL, MKDEV(VCS_MAJOR, index + 1), NULL,
+		      "vcs%u", index + 1);
+	device_create(vc_class, NULL, MKDEV(VCS_MAJOR, index + 129), NULL,
+		      "vcsa%u", index + 1);
+}
+
+void vcs_remove_sysfs(int index)
+{
+	device_destroy(vc_class, MKDEV(VCS_MAJOR, index + 1));
+	device_destroy(vc_class, MKDEV(VCS_MAJOR, index + 129));
+}
+
+int __init vcs_init(void)
+{
+	unsigned int i;
+
+	if (register_chrdev(VCS_MAJOR, "vcs", &vcs_fops))
+		panic("unable to get major %d for vcs device", VCS_MAJOR);
+	vc_class = class_create(THIS_MODULE, "vc");
+
+	device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 0), NULL, "vcs");
+	device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 128), NULL, "vcsa");
+	for (i = 0; i < MIN_NR_CONSOLES; i++)
+		vcs_make_sysfs(i);
+	return 0;
+}