Merge ../torvalds-2.6/

25 files changed, 1178 insertions, 1050 deletions

diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index 5b58fad4529..cd13b91b9ff 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -58,7 +58,7 @@ static void *not_configged_init(char *str, int device, struct chan_opts *opts)
 {
 	my_puts("Using a channel type which is configured out of "
 	       "UML\n");
-	return(NULL);
+	return NULL;
 }
 
 static int not_configged_open(int input, int output, int primary, void *data,
@@ -66,7 +66,7 @@ static int not_configged_open(int input, int output, int primary, void *data,
 {
 	my_puts("Using a channel type which is configured out of "
 	       "UML\n");
-	return(-ENODEV);
+	return -ENODEV;
 }
 
 static void not_configged_close(int fd, void *data)
@@ -79,21 +79,21 @@ static int not_configged_read(int fd, char *c_out, void *data)
 {
 	my_puts("Using a channel type which is configured out of "
 	       "UML\n");
-	return(-EIO);
+	return -EIO;
 }
 
 static int not_configged_write(int fd, const char *buf, int len, void *data)
 {
 	my_puts("Using a channel type which is configured out of "
 	       "UML\n");
-	return(-EIO);
+	return -EIO;
 }
 
 static int not_configged_console_write(int fd, const char *buf, int len)
 {
 	my_puts("Using a channel type which is configured out of "
 	       "UML\n");
-	return(-EIO);
+	return -EIO;
 }
 
 static int not_configged_window_size(int fd, void *data, unsigned short *rows,
@@ -101,7 +101,7 @@ static int not_configged_window_size(int fd, void *data, unsigned short *rows,
 {
 	my_puts("Using a channel type which is configured out of "
 	       "UML\n");
-	return(-ENODEV);
+	return -ENODEV;
 }
 
 static void not_configged_free(void *data)
@@ -135,17 +135,17 @@ int generic_read(int fd, char *c_out, void *unused)
 	n = os_read_file(fd, c_out, sizeof(*c_out));
 
 	if(n == -EAGAIN)
-		return(0);
+		return 0;
 	else if(n == 0)
-		return(-EIO);
-	return(n);
+		return -EIO;
+	return n;
 }
 
 /* XXX Trivial wrapper around os_write_file */
 
 int generic_write(int fd, const char *buf, int n, void *unused)
 {
-	return(os_write_file(fd, buf, n));
+	return os_write_file(fd, buf, n);
 }
 
 int generic_window_size(int fd, void *unused, unsigned short *rows_out,
@@ -156,14 +156,14 @@ int generic_window_size(int fd, void *unused, unsigned short *rows_out,
 
 	ret = os_window_size(fd, &rows, &cols);
 	if(ret < 0)
-		return(ret);
+		return ret;
 
 	ret = ((*rows_out != rows) || (*cols_out != cols));
 
 	*rows_out = rows;
 	*cols_out = cols;
 
-	return(ret);
+	return ret;
 }
 
 void generic_free(void *data)
@@ -186,25 +186,29 @@ static void tty_receive_char(struct tty_struct *tty, char ch)
 		}
 	}
 
-	if((tty->flip.flag_buf_ptr == NULL) || 
+	if((tty->flip.flag_buf_ptr == NULL) ||
 	   (tty->flip.char_buf_ptr == NULL))
 		return;
 	tty_insert_flip_char(tty, ch, TTY_NORMAL);
 }
 
-static int open_one_chan(struct chan *chan, int input, int output, int primary)
+static int open_one_chan(struct chan *chan)
 {
 	int fd;
 
-	if(chan->opened) return(0);
-	if(chan->ops->open == NULL) fd = 0;
-	else fd = (*chan->ops->open)(input, output, primary, chan->data,
-				     &chan->dev);
-	if(fd < 0) return(fd);
+	if(chan->opened)
+		return 0;
+
+	if(chan->ops->open == NULL)
+		fd = 0;
+	else fd = (*chan->ops->open)(chan->input, chan->output, chan->primary,
+				     chan->data, &chan->dev);
+	if(fd < 0)
+		return fd;
 	chan->fd = fd;
 
 	chan->opened = 1;
-	return(0);
+	return 0;
 }
 
 int open_chan(struct list_head *chans)
@@ -215,11 +219,11 @@ int open_chan(struct list_head *chans)
 
 	list_for_each(ele, chans){
 		chan = list_entry(ele, struct chan, list);
-		ret = open_one_chan(chan, chan->input, chan->output,
-				    chan->primary);
-		if(chan->primary) err = ret;
+		ret = open_one_chan(chan);
+		if(chan->primary)
+			err = ret;
 	}
-	return(err);
+	return err;
 }
 
 void chan_enable_winch(struct list_head *chans, struct tty_struct *tty)
@@ -236,20 +240,65 @@ void chan_enable_winch(struct list_head *chans, struct tty_struct *tty)
 	}
 }
 
-void enable_chan(struct list_head *chans, struct tty_struct *tty)
+void enable_chan(struct line *line)
 {
 	struct list_head *ele;
 	struct chan *chan;
 
-	list_for_each(ele, chans){
+	list_for_each(ele, &line->chan_list){
 		chan = list_entry(ele, struct chan, list);
-		if(!chan->opened) continue;
+		if(open_one_chan(chan))
+			continue;
+
+		if(chan->enabled)
+			continue;
+		line_setup_irq(chan->fd, chan->input, chan->output, line,
+			       chan);
+		chan->enabled = 1;
+	}
+}
+
+static LIST_HEAD(irqs_to_free);
+
+void free_irqs(void)
+{
+	struct chan *chan;
+
+	while(!list_empty(&irqs_to_free)){
+		chan = list_entry(irqs_to_free.next, struct chan, free_list);
+		list_del(&chan->free_list);
 
-		line_setup_irq(chan->fd, chan->input, chan->output, tty);
+		if(chan->input)
+			free_irq(chan->line->driver->read_irq, chan);
+		if(chan->output)
+			free_irq(chan->line->driver->write_irq, chan);
+		chan->enabled = 0;
+	}
+}
+
+static void close_one_chan(struct chan *chan, int delay_free_irq)
+{
+	if(!chan->opened)
+		return;
+
+	if(delay_free_irq){
+		list_add(&chan->free_list, &irqs_to_free);
 	}
+	else {
+		if(chan->input)
+			free_irq(chan->line->driver->read_irq, chan);
+		if(chan->output)
+			free_irq(chan->line->driver->write_irq, chan);
+		chan->enabled = 0;
+	}
+	if(chan->ops->close != NULL)
+		(*chan->ops->close)(chan->fd, chan->data);
+
+	chan->opened = 0;
+	chan->fd = -1;
 }
 
-void close_chan(struct list_head *chans)
+void close_chan(struct list_head *chans, int delay_free_irq)
 {
 	struct chan *chan;
 
@@ -259,15 +308,37 @@ void close_chan(struct list_head *chans)
 	 * so it must be the last closed.
 	 */
 	list_for_each_entry_reverse(chan, chans, list) {
-		if(!chan->opened) continue;
-		if(chan->ops->close != NULL)
-			(*chan->ops->close)(chan->fd, chan->data);
-		chan->opened = 0;
-		chan->fd = -1;
+		close_one_chan(chan, delay_free_irq);
+	}
+}
+
+void deactivate_chan(struct list_head *chans, int irq)
+{
+	struct list_head *ele;
+
+	struct chan *chan;
+	list_for_each(ele, chans) {
+		chan = list_entry(ele, struct chan, list);
+
+		if(chan->enabled && chan->input)
+			deactivate_fd(chan->fd, irq);
+	}
+}
+
+void reactivate_chan(struct list_head *chans, int irq)
+{
+	struct list_head *ele;
+	struct chan *chan;
+
+	list_for_each(ele, chans) {
+		chan = list_entry(ele, struct chan, list);
+
+		if(chan->enabled && chan->input)
+			reactivate_fd(chan->fd, irq);
 	}
 }
 
-int write_chan(struct list_head *chans, const char *buf, int len, 
+int write_chan(struct list_head *chans, const char *buf, int len,
 	       int write_irq)
 {
 	struct list_head *ele;
@@ -285,7 +356,7 @@ int write_chan(struct list_head *chans, const char *buf, int len,
 				reactivate_fd(chan->fd, write_irq);
 		}
 	}
-	return(ret);
+	return ret;
 }
 
 int console_write_chan(struct list_head *chans, const char *buf, int len)
@@ -301,19 +372,18 @@ int console_write_chan(struct list_head *chans, const char *buf, int len)
 		n = chan->ops->console_write(chan->fd, buf, len);
 		if(chan->primary) ret = n;
 	}
-	return(ret);
+	return ret;
 }
 
-int console_open_chan(struct line *line, struct console *co, struct chan_opts *opts)
+int console_open_chan(struct line *line, struct console *co,
+		      struct chan_opts *opts)
 {
-	if (!list_empty(&line->chan_list))
-		return 0;
+	int err;
+
+	err = open_chan(&line->chan_list);
+	if(err)
+		return err;
 
-	if (0 != parse_chan_pair(line->init_str, &line->chan_list,
-				 line->init_pri, co->index, opts))
-		return -1;
-	if (0 != open_chan(&line->chan_list))
-		return -1;
 	printk("Console initialized on /dev/%s%d\n",co->name,co->index);
 	return 0;
 }
@@ -327,32 +397,36 @@ int chan_window_size(struct list_head *chans, unsigned short *rows_out,
 	list_for_each(ele, chans){
 		chan = list_entry(ele, struct chan, list);
 		if(chan->primary){
-			if(chan->ops->window_size == NULL) return(0);
-			return(chan->ops->window_size(chan->fd, chan->data,
-						      rows_out, cols_out));
+			if(chan->ops->window_size == NULL)
+				return 0;
+			return chan->ops->window_size(chan->fd, chan->data,
+						      rows_out, cols_out);
 		}
 	}
-	return(0);
+	return 0;
 }
 
-void free_one_chan(struct chan *chan)
+void free_one_chan(struct chan *chan, int delay_free_irq)
 {
 	list_del(&chan->list);
+
+	close_one_chan(chan, delay_free_irq);
+
 	if(chan->ops->free != NULL)
 		(*chan->ops->free)(chan->data);
-	free_irq_by_fd(chan->fd);
+
 	if(chan->primary && chan->output) ignore_sigio_fd(chan->fd);
 	kfree(chan);
 }
 
-void free_chan(struct list_head *chans)
+void free_chan(struct list_head *chans, int delay_free_irq)
 {
 	struct list_head *ele, *next;
 	struct chan *chan;
 
 	list_for_each_safe(ele, next, chans){
 		chan = list_entry(ele, struct chan, list);
-		free_one_chan(chan);
+		free_one_chan(chan, delay_free_irq);
 	}
 }
 
@@ -363,23 +437,23 @@ static int one_chan_config_string(struct chan *chan, char *str, int size,
 
 	if(chan == NULL){
 		CONFIG_CHUNK(str, size, n, "none", 1);
-		return(n);
+		return n;
 	}
 
 	CONFIG_CHUNK(str, size, n, chan->ops->type, 0);
 
 	if(chan->dev == NULL){
 		CONFIG_CHUNK(str, size, n, "", 1);
-		return(n);
+		return n;
 	}
 
 	CONFIG_CHUNK(str, size, n, ":", 0);
 	CONFIG_CHUNK(str, size, n, chan->dev, 0);
 
-	return(n);
+	return n;
 }
 
-static int chan_pair_config_string(struct chan *in, struct chan *out, 
+static int chan_pair_config_string(struct chan *in, struct chan *out,
 				   char *str, int size, char **error_out)
 {
 	int n;
@@ -390,7 +464,7 @@ static int chan_pair_config_string(struct chan *in, struct chan *out,
 
 	if(in == out){
 		CONFIG_CHUNK(str, size, n, "", 1);
-		return(n);
+		return n;
 	}
 
 	CONFIG_CHUNK(str, size, n, ",", 1);
@@ -399,10 +473,10 @@ static int chan_pair_config_string(struct chan *in, struct chan *out,
 	size -= n;
 	CONFIG_CHUNK(str, size, n, "", 1);
 
-	return(n);
+	return n;
 }
 
-int chan_config_string(struct list_head *chans, char *str, int size, 
+int chan_config_string(struct list_head *chans, char *str, int size,
 		       char **error_out)
 {
 	struct list_head *ele;
@@ -418,7 +492,7 @@ int chan_config_string(struct list_head *chans, char *str, int size,
 			out = chan;
 	}
 
-	return(chan_pair_config_string(in, out, str, size, error_out));
+	return chan_pair_config_string(in, out, str, size, error_out);
 }
 
 struct chan_type {
@@ -462,7 +536,7 @@ struct chan_type chan_table[] = {
 #endif
 };
 
-static struct chan *parse_chan(char *str, int pri, int device, 
+static struct chan *parse_chan(struct line *line, char *str, int device,
 			       struct chan_opts *opts)
 {
 	struct chan_type *entry;
@@ -484,36 +558,42 @@ static struct chan *parse_chan(char *str, int pri, int device,
 	if(ops == NULL){
 		my_printf("parse_chan couldn't parse \"%s\"\n",
 		       str);
-		return(NULL);
+		return NULL;
 	}
-	if(ops->init == NULL) return(NULL); 
+	if(ops->init == NULL)
+		return NULL;
 	data = (*ops->init)(str, device, opts);
-	if(data == NULL) return(NULL);
+	if(data == NULL)
+		return NULL;
 
 	chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
-	if(chan == NULL) return(NULL);
+	if(chan == NULL)
+		return NULL;
 	*chan = ((struct chan) { .list	 	= LIST_HEAD_INIT(chan->list),
+				 .free_list 	=
+				 	LIST_HEAD_INIT(chan->free_list),
+				 .line		= line,
 				 .primary	= 1,
 				 .input		= 0,
 				 .output 	= 0,
 				 .opened  	= 0,
+				 .enabled  	= 0,
 				 .fd 		= -1,
-				 .pri 		= pri,
 				 .ops 		= ops,
 				 .data 		= data });
-	return(chan);
+	return chan;
 }
 
-int parse_chan_pair(char *str, struct list_head *chans, int pri, int device,
+int parse_chan_pair(char *str, struct line *line, int device,
 		    struct chan_opts *opts)
 {
+	struct list_head *chans = &line->chan_list;
 	struct chan *new, *chan;
 	char *in, *out;
 
 	if(!list_empty(chans)){
 		chan = list_entry(chans->next, struct chan, list);
-		if(chan->pri >= pri) return(0);
-		free_chan(chans);
+		free_chan(chans, 0);
 		INIT_LIST_HEAD(chans);
 	}
 
@@ -522,24 +602,30 @@ int parse_chan_pair(char *str, struct list_head *chans, int pri, int device,
 		in = str;
 		*out = '\0';
 		out++;
-		new = parse_chan(in, pri, device, opts);
-		if(new == NULL) return(-1);
+		new = parse_chan(line, in, device, opts);
+		if(new == NULL)
+			return -1;
+
 		new->input = 1;
 		list_add(&new->list, chans);
 
-		new = parse_chan(out, pri, device, opts);
-		if(new == NULL) return(-1);
+		new = parse_chan(line, out, device, opts);
+		if(new == NULL)
+			return -1;
+
 		list_add(&new->list, chans);
 		new->output = 1;
 	}
 	else {
-		new = parse_chan(str, pri, device, opts);
-		if(new == NULL) return(-1);
+		new = parse_chan(line, str, device, opts);
+		if(new == NULL)
+			return -1;
+
 		list_add(&new->list, chans);
 		new->input = 1;
 		new->output = 1;
 	}
-	return(0);
+	return 0;
 }
 
 int chan_out_fd(struct list_head *chans)
@@ -550,9 +636,9 @@ int chan_out_fd(struct list_head *chans)
 	list_for_each(ele, chans){
 		chan = list_entry(ele, struct chan, list);
 		if(chan->primary && chan->output)
-			return(chan->fd);
+			return chan->fd;
 	}
-	return(-1);
+	return -1;
 }
 
 void chan_interrupt(struct list_head *chans, struct work_struct *task,
@@ -567,9 +653,9 @@ void chan_interrupt(struct list_head *chans, struct work_struct *task,
 		chan = list_entry(ele, struct chan, list);
 		if(!chan->input || (chan->ops->read == NULL)) continue;
 		do {
-			if((tty != NULL) && 
+			if((tty != NULL) &&
 			   (tty->flip.count >= TTY_FLIPBUF_SIZE)){
-				schedule_work(task);
+				schedule_delayed_work(task, 1);
 				goto out;
 			}
 			err = chan->ops->read(chan->fd, &c, chan->data);
@@ -582,29 +668,12 @@ void chan_interrupt(struct list_head *chans, struct work_struct *task,
 			if(chan->primary){
 				if(tty != NULL)
 					tty_hangup(tty);
-				line_disable(tty, irq);
-				close_chan(chans);
-				free_chan(chans);
+				close_chan(chans, 1);
 				return;
 			}
-			else {
-				if(chan->ops->close != NULL)
-					chan->ops->close(chan->fd, chan->data);
-				free_one_chan(chan);
-			}
+			else close_one_chan(chan, 1);
 		}
 	}
  out:
 	if(tty) tty_flip_buffer_push(tty);
 }
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index e0fdffa2d54..46ceb25a995 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -23,8 +23,9 @@
 
 static irqreturn_t line_interrupt(int irq, void *data, struct pt_regs *unused)
 {
-	struct tty_struct *tty = data;
-	struct line *line = tty->driver_data;
+	struct chan *chan = data;
+	struct line *line = chan->line;
+	struct tty_struct *tty = line->tty;
 
 	if (line)
 		chan_interrupt(&line->chan_list, &line->task, tty, irq);
@@ -33,10 +34,11 @@ static irqreturn_t line_interrupt(int irq, void *data, struct pt_regs *unused)
 
 static void line_timer_cb(void *arg)
 {
-	struct tty_struct *tty = arg;
-	struct line *line = tty->driver_data;
+	struct line *line = arg;
 
-	line_interrupt(line->driver->read_irq, arg, NULL);
+	if(!line->throttled)
+		chan_interrupt(&line->chan_list, &line->task, line->tty,
+			       line->driver->read_irq);
 }
 
 /* Returns the free space inside the ring buffer of this line.
@@ -124,7 +126,8 @@ static int buffer_data(struct line *line, const char *buf, int len)
 	if (len < end){
 		memcpy(line->tail, buf, len);
 		line->tail += len;
-	} else {
+	}
+	else {
 		/* The circular buffer is wrapping */
 		memcpy(line->tail, buf, end);
 		buf += end;
@@ -170,7 +173,7 @@ static int flush_buffer(struct line *line)
 	}
 
 	count = line->tail - line->head;
-	n = write_chan(&line->chan_list, line->head, count, 
+	n = write_chan(&line->chan_list, line->head, count,
 		       line->driver->write_irq);
 
 	if(n < 0)
@@ -227,7 +230,7 @@ int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
 		if (err <= 0 && (err != -EAGAIN || !ret))
 			ret = err;
 	} else {
-		n = write_chan(&line->chan_list, buf, len, 
+		n = write_chan(&line->chan_list, buf, len,
 			       line->driver->write_irq);
 		if (n < 0) {
 			ret = n;
@@ -338,11 +341,36 @@ int line_ioctl(struct tty_struct *tty, struct file * file,
 	return ret;
 }
 
+void line_throttle(struct tty_struct *tty)
+{
+	struct line *line = tty->driver_data;
+
+	deactivate_chan(&line->chan_list, line->driver->read_irq);
+	line->throttled = 1;
+}
+
+void line_unthrottle(struct tty_struct *tty)
+{
+	struct line *line = tty->driver_data;
+
+	line->throttled = 0;
+	chan_interrupt(&line->chan_list, &line->task, tty,
+		       line->driver->read_irq);
+
+	/* Maybe there is enough stuff pending that calling the interrupt
+	 * throttles us again.  In this case, line->throttled will be 1
+	 * again and we shouldn't turn the interrupt back on.
+	 */
+	if(!line->throttled)
+		reactivate_chan(&line->chan_list, line->driver->read_irq);
+}
+
 static irqreturn_t line_write_interrupt(int irq, void *data,
 					struct pt_regs *unused)
 {
-	struct tty_struct *tty = data;
-	struct line *line = tty->driver_data;
+	struct chan *chan = data;
+	struct line *line = chan->line;
+	struct tty_struct *tty = line->tty;
 	int err;
 
 	/* Interrupts are enabled here because we registered the interrupt with
@@ -364,7 +392,7 @@ static irqreturn_t line_write_interrupt(int irq, void *data,
 	if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) &&
 	   (tty->ldisc.write_wakeup != NULL))
 		(tty->ldisc.write_wakeup)(tty);
-	
+
 	/* BLOCKING mode
 	 * In blocking mode, everything sleeps on tty->write_wait.
 	 * Sleeping in the console driver would break non-blocking
@@ -376,53 +404,29 @@ static irqreturn_t line_write_interrupt(int irq, void *data,
 	return IRQ_HANDLED;
 }
 
-int line_setup_irq(int fd, int input, int output, struct tty_struct *tty)
+int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
 {
-	struct line *line = tty->driver_data;
 	struct line_driver *driver = line->driver;
 	int err = 0, flags = SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM;
 
 	if (input)
 		err = um_request_irq(driver->read_irq, fd, IRQ_READ,
-				       line_interrupt, flags, 
-				       driver->read_irq_name, tty);
+				       line_interrupt, flags,
+				       driver->read_irq_name, data);
 	if (err)
 		return err;
 	if (output)
 		err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
-					line_write_interrupt, flags, 
-					driver->write_irq_name, tty);
+					line_write_interrupt, flags,
+					driver->write_irq_name, data);
 	line->have_irq = 1;
 	return err;
 }
 
-void line_disable(struct tty_struct *tty, int current_irq)
-{
-	struct line *line = tty->driver_data;
-
-	if(!line->have_irq)
-		return;
-
-	if(line->driver->read_irq == current_irq)
-		free_irq_later(line->driver->read_irq, tty);
-	else {
-		free_irq(line->driver->read_irq, tty);
-	}
-
-	if(line->driver->write_irq == current_irq)
-		free_irq_later(line->driver->write_irq, tty);
-	else {
-		free_irq(line->driver->write_irq, tty);
-	}
-
-	line->have_irq = 0;
-}
-
-int line_open(struct line *lines, struct tty_struct *tty,
-	      struct chan_opts *opts)
+int line_open(struct line *lines, struct tty_struct *tty)
 {
 	struct line *line;
-	int err = 0;
+	int err = -ENODEV;
 
 	line = &lines[tty->index];
 	tty->driver_data = line;
@@ -430,31 +434,29 @@ int line_open(struct line *lines, struct tty_struct *tty,
 	/* The IRQ which takes this lock is not yet enabled and won't be run
 	 * before the end, so we don't need to use spin_lock_irq.*/
 	spin_lock(&line->lock);
-	if (tty->count == 1) {
-		if (!line->valid) {
-			err = -ENODEV;
-			goto out;
-		}
-		if (list_empty(&line->chan_list)) {
-			err = parse_chan_pair(line->init_str, &line->chan_list,
-					      line->init_pri, tty->index, opts);
-			if(err) goto out;
-			err = open_chan(&line->chan_list);
-			if(err) goto out;
+
+	tty->driver_data = line;
+	line->tty = tty;
+	if(!line->valid)
+		goto out;
+
+	if(tty->count == 1){
+		/* Here the device is opened, if necessary, and interrupt
+		 * is registered.
+		 */
+		enable_chan(line);
+		INIT_WORK(&line->task, line_timer_cb, line);
+
+		if(!line->sigio){
+			chan_enable_winch(&line->chan_list, tty);
+			line->sigio = 1;
 		}
-		/* Here the interrupt is registered.*/
-		enable_chan(&line->chan_list, tty);
-		INIT_WORK(&line->task, line_timer_cb, tty);
-	}
 
-	if(!line->sigio){
-		chan_enable_winch(&line->chan_list, tty);
-		line->sigio = 1;
+		chan_window_size(&line->chan_list, &tty->winsize.ws_row,
+				 &tty->winsize.ws_col);
 	}
-	chan_window_size(&line->chan_list, &tty->winsize.ws_row,
-			 &tty->winsize.ws_col);
-	line->count++;
 
+	err = 0;
 out:
 	spin_unlock(&line->lock);
 	return err;
@@ -474,15 +476,14 @@ void line_close(struct tty_struct *tty, struct file * filp)
 	/* We ignore the error anyway! */
 	flush_buffer(line);
 
-	line->count--;
-	if (tty->count == 1) {
-		line_disable(tty, -1);
+	if(tty->count == 1){
+		line->tty = NULL;
 		tty->driver_data = NULL;
-	}
 
-        if((line->count == 0) && line->sigio){
-                unregister_winch(tty);
-                line->sigio = 0;
+		if(line->sigio){
+			unregister_winch(tty);
+			line->sigio = 0;
+		}
         }
 
 	spin_unlock_irq(&line->lock);
@@ -493,17 +494,15 @@ void close_lines(struct line *lines, int nlines)
 	int i;
 
 	for(i = 0; i < nlines; i++)
-		close_chan(&lines[i].chan_list);
+		close_chan(&lines[i].chan_list, 0);
 }
 
 /* Common setup code for both startup command line and mconsole initialization.
  * @lines contains the the array (of size @num) to modify;
  * @init is the setup string;
- * @all_allowed is a boolean saying if we can setup the whole @lines
- * at once. For instance, it will be usually true for startup init. (where we
- * can use con=xterm) and false for mconsole.*/
+ */
 
-int line_setup(struct line *lines, unsigned int num, char *init, int all_allowed)
+int line_setup(struct line *lines, unsigned int num, char *init)
 {
 	int i, n;
 	char *end;
@@ -512,10 +511,11 @@ int line_setup(struct line *lines, unsigned int num, char *init, int all_allowed
 		/* We said con=/ssl= instead of con#=, so we are configuring all
 		 * consoles at once.*/
 		n = -1;
-	} else {
+	}
+	else {
 		n = simple_strtoul(init, &end, 0);
 		if(*end != '='){
-			printk(KERN_ERR "line_setup failed to parse \"%s\"\n", 
+			printk(KERN_ERR "line_setup failed to parse \"%s\"\n",
 			       init);
 			return 0;
 		}
@@ -527,8 +527,9 @@ int line_setup(struct line *lines, unsigned int num, char *init, int all_allowed
 		printk("line_setup - %d out of range ((0 ... %d) allowed)\n",
 		       n, num - 1);
 		return 0;
-	} else if (n >= 0){
-		if (lines[n].count > 0) {
+	}
+	else if (n >= 0){
+		if (lines[n].tty != NULL) {
 			printk("line_setup - device %d is open\n", n);
 			return 0;
 		}
@@ -539,13 +540,10 @@ int line_setup(struct line *lines, unsigned int num, char *init, int all_allowed
 			else {
 				lines[n].init_str = init;
 				lines[n].valid = 1;
-			}	
+			}
 		}
-	} else if(!all_allowed){
-		printk("line_setup - can't configure all devices from "
-		       "mconsole\n");
-		return 0;
-	} else {
+	}
+	else {
 		for(i = 0; i < num; i++){
 			if(lines[i].init_pri <= INIT_ALL){
 				lines[i].init_pri = INIT_ALL;
@@ -557,18 +555,33 @@ int line_setup(struct line *lines, unsigned int num, char *init, int all_allowed
 			}
 		}
 	}
-	return 1;
+	return n == -1 ? num : n;
 }
 
-int line_config(struct line *lines, unsigned int num, char *str)
+int line_config(struct line *lines, unsigned int num, char *str,
+		struct chan_opts *opts)
 {
-	char *new = uml_strdup(str);
+	struct line *line;
+	char *new;
+	int n;
 
+	if(*str == '='){
+		printk("line_config - can't configure all devices from "
+		       "mconsole\n");
+		return 1;
+	}
+
+	new = kstrdup(str, GFP_KERNEL);
 	if(new == NULL){
-		printk("line_config - uml_strdup failed\n");
-		return -ENOMEM;
+		printk("line_config - kstrdup failed\n");
+		return 1;
 	}
-	return !line_setup(lines, num, new, 0);
+	n = line_setup(lines, num, new);
+	if(n < 0)
+		return 1;
+
+	line = &lines[n];
+	return parse_chan_pair(line->init_str, line, n, opts);
 }
 
 int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
@@ -594,7 +607,7 @@ int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
 	spin_lock(&line->lock);
 	if(!line->valid)
 		CONFIG_CHUNK(str, size, n, "none", 1);
-	else if(line->count == 0)
+	else if(line->tty == NULL)
 		CONFIG_CHUNK(str, size, n, line->init_str, 1);
 	else n = chan_config_string(&line->chan_list, str, size, error_out);
 	spin_unlock(&line->lock);
@@ -619,14 +632,18 @@ int line_id(char **str, int *start_out, int *end_out)
 
 int line_remove(struct line *lines, unsigned int num, int n)
 {
+	int err;
 	char config[sizeof("conxxxx=none\0")];
 
 	sprintf(config, "%d=none", n);
-	return !line_setup(lines, num, config, 0);
+	err = line_setup(lines, num, config);
+	if(err >= 0)
+		err = 0;
+	return err;
 }
 
 struct tty_driver *line_register_devfs(struct lines *set,
-			 struct line_driver *line_driver, 
+			 struct line_driver *line_driver,
 			 struct tty_operations *ops, struct line *lines,
 			 int nlines)
 {
@@ -655,7 +672,7 @@ struct tty_driver *line_register_devfs(struct lines *set,
 	}
 
 	for(i = 0; i < nlines; i++){
-		if(!lines[i].valid) 
+		if(!lines[i].valid)
 			tty_unregister_device(driver, i);
 	}
 
@@ -663,24 +680,28 @@ struct tty_driver *line_register_devfs(struct lines *set,
 	return driver;
 }
 
-static spinlock_t winch_handler_lock;
-LIST_HEAD(winch_handlers);
+static DEFINE_SPINLOCK(winch_handler_lock);
+static LIST_HEAD(winch_handlers);
 
-void lines_init(struct line *lines, int nlines)
+void lines_init(struct line *lines, int nlines, struct chan_opts *opts)
 {
 	struct line *line;
 	int i;
 
-	spin_lock_init(&winch_handler_lock);
 	for(i = 0; i < nlines; i++){
 		line = &lines[i];
 		INIT_LIST_HEAD(&line->chan_list);
-		spin_lock_init(&line->lock);
-		if(line->init_str != NULL){
-			line->init_str = uml_strdup(line->init_str);
-			if(line->init_str == NULL)
-				printk("lines_init - uml_strdup returned "
-				       "NULL\n");
+
+		if(line->init_str == NULL)
+			continue;
+
+		line->init_str = kstrdup(line->init_str, GFP_KERNEL);
+		if(line->init_str == NULL)
+			printk("lines_init - kstrdup returned NULL\n");
+
+		if(parse_chan_pair(line->init_str, line, i, opts)){
+			printk("parse_chan_pair failed for device %d\n", i);
+			line->valid = 0;
 		}
 	}
 }
@@ -717,8 +738,7 @@ irqreturn_t winch_interrupt(int irq, void *data, struct pt_regs *unused)
 	tty  = winch->tty;
 	if (tty != NULL) {
 		line = tty->driver_data;
-		chan_window_size(&line->chan_list,
-				 &tty->winsize.ws_row, 
+		chan_window_size(&line->chan_list, &tty->winsize.ws_row,
 				 &tty->winsize.ws_col);
 		kill_pg(tty->pgrp, SIGWINCH, 1);
 	}
@@ -749,60 +769,54 @@ void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty)
 	spin_unlock(&winch_handler_lock);
 
 	if(um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
-			  SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM, 
+			  SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM,
 			  "winch", winch) < 0)
 		printk("register_winch_irq - failed to register IRQ\n");
 }
 
+static void free_winch(struct winch *winch)
+{
+	list_del(&winch->list);
+
+	if(winch->pid != -1)
+		os_kill_process(winch->pid, 1);
+	if(winch->fd != -1)
+		os_close_file(winch->fd);
+
+	free_irq(WINCH_IRQ, winch);
+	kfree(winch);
+}
+
 static void unregister_winch(struct tty_struct *tty)
 {
 	struct list_head *ele;
-	struct winch *winch, *found = NULL;
+	struct winch *winch;
 
 	spin_lock(&winch_handler_lock);
+
 	list_for_each(ele, &winch_handlers){
 		winch = list_entry(ele, struct winch, list);
                 if(winch->tty == tty){
-                        found = winch;
-                        break;
+			free_winch(winch);
+			break;
                 }
         }
-        if(found == NULL)
-		goto err;
-
-	list_del(&winch->list);
-	spin_unlock(&winch_handler_lock);
-
-        if(winch->pid != -1)
-                os_kill_process(winch->pid, 1);
-
-        free_irq(WINCH_IRQ, winch);
-        kfree(winch);
-
-	return;
-err:
 	spin_unlock(&winch_handler_lock);
 }
 
-/* XXX: No lock as it's an exitcall... is this valid? Depending on cleanup
- * order... are we sure that nothing else is done on the list? */
 static void winch_cleanup(void)
 {
-	struct list_head *ele;
+	struct list_head *ele, *next;
 	struct winch *winch;
 
-	list_for_each(ele, &winch_handlers){
+	spin_lock(&winch_handler_lock);
+
+	list_for_each_safe(ele, next, &winch_handlers){
 		winch = list_entry(ele, struct winch, list);
-		if(winch->fd != -1){
-			/* Why is this different from the above free_irq(),
-			 * which deactivates SIGIO? This searches the FD
-			 * somewhere else and removes it from the list... */
-			deactivate_fd(winch->fd, WINCH_IRQ);
-			os_close_file(winch->fd);
-		}
-		if(winch->pid != -1) 
-			os_kill_process(winch->pid, 1);
+		free_winch(winch);
 	}
+
+	spin_unlock(&winch_handler_lock);
 }
 __uml_exitcall(winch_cleanup);
 
@@ -811,10 +825,10 @@ char *add_xterm_umid(char *base)
 	char *umid, *title;
 	int len;
 
-	umid = get_umid(1);
-	if(umid == NULL)
+	umid = get_umid();
+	if(*umid == '\0')
 		return base;
-	
+
 	len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
 	title = kmalloc(len, GFP_KERNEL);
 	if(title == NULL){
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 12c95368124..be610125429 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -20,6 +20,7 @@
 #include "linux/namei.h"
 #include "linux/proc_fs.h"
 #include "linux/syscalls.h"
+#include "linux/console.h"
 #include "asm/irq.h"
 #include "asm/uaccess.h"
 #include "user_util.h"
@@ -34,7 +35,7 @@
 #include "irq_kern.h"
 #include "choose-mode.h"
 
-static int do_unlink_socket(struct notifier_block *notifier, 
+static int do_unlink_socket(struct notifier_block *notifier,
 			    unsigned long what, void *data)
 {
 	return(mconsole_unlink_socket());
@@ -46,12 +47,12 @@ static struct notifier_block reboot_notifier = {
 	.priority		= 0,
 };
 
-/* Safe without explicit locking for now.  Tasklets provide their own 
+/* Safe without explicit locking for now.  Tasklets provide their own
  * locking, and the interrupt handler is safe because it can't interrupt
  * itself and it can only happen on CPU 0.
  */
 
-LIST_HEAD(mc_requests);
+static LIST_HEAD(mc_requests);
 
 static void mc_work_proc(void *unused)
 {
@@ -60,7 +61,7 @@ static void mc_work_proc(void *unused)
 
 	while(!list_empty(&mc_requests)){
 		local_save_flags(flags);
-		req = list_entry(mc_requests.next, struct mconsole_entry, 
+		req = list_entry(mc_requests.next, struct mconsole_entry,
 				 list);
 		list_del(&req->list);
 		local_irq_restore(flags);
@@ -69,7 +70,7 @@ static void mc_work_proc(void *unused)
 	}
 }
 
-DECLARE_WORK(mconsole_work, mc_work_proc, NULL);
+static DECLARE_WORK(mconsole_work, mc_work_proc, NULL);
 
 static irqreturn_t mconsole_interrupt(int irq, void *dev_id,
 				      struct pt_regs *regs)
@@ -103,8 +104,8 @@ void mconsole_version(struct mc_request *req)
 {
 	char version[256];
 
-	sprintf(version, "%s %s %s %s %s", system_utsname.sysname, 
-		system_utsname.nodename, system_utsname.release, 
+	sprintf(version, "%s %s %s %s %s", system_utsname.sysname,
+		system_utsname.nodename, system_utsname.release,
 		system_utsname.version, system_utsname.machine);
 	mconsole_reply(req, version, 0, 0);
 }
@@ -348,7 +349,7 @@ static struct mc_device *mconsole_find_dev(char *name)
 
 #define CONFIG_BUF_SIZE 64
 
-static void mconsole_get_config(int (*get_config)(char *, char *, int, 
+static void mconsole_get_config(int (*get_config)(char *, char *, int,
 						  char **),
 				struct mc_request *req, char *name)
 {
@@ -389,7 +390,6 @@ static void mconsole_get_config(int (*get_config)(char *, char *, int,
  out:
 	if(buf != default_buf)
 		kfree(buf);
-	
 }
 
 void mconsole_config(struct mc_request *req)
@@ -420,9 +420,9 @@ void mconsole_config(struct mc_request *req)
 
 void mconsole_remove(struct mc_request *req)
 {
-	struct mc_device *dev;	
+	struct mc_device *dev;
 	char *ptr = req->request.data, *err_msg = "";
-        char error[256];
+	char error[256];
 	int err, start, end, n;
 
 	ptr += strlen("remove");
@@ -433,37 +433,112 @@ void mconsole_remove(struct mc_request *req)
 		return;
 	}
 
-        ptr = &ptr[strlen(dev->name)];
-
-        err = 1;
-        n = (*dev->id)(&ptr, &start, &end);
-        if(n < 0){
-                err_msg = "Couldn't parse device number";
-                goto out;
-        }
-        else if((n < start) || (n > end)){
-                sprintf(error, "Invalid device number - must be between "
-                        "%d and %d", start, end);
-                err_msg = error;
-                goto out;
-        }
+	ptr = &ptr[strlen(dev->name)];
+
+	err = 1;
+	n = (*dev->id)(&ptr, &start, &end);
+	if(n < 0){
+		err_msg = "Couldn't parse device number";
+		goto out;
+	}
+	else if((n < start) || (n > end)){
+		sprintf(error, "Invalid device number - must be between "
+			"%d and %d", start, end);
+		err_msg = error;
+		goto out;
+	}
 
 	err = (*dev->remove)(n);
-        switch(err){
-        case -ENODEV:
-                err_msg = "Device doesn't exist";
-                break;
-        case -EBUSY:
-                err_msg = "Device is currently open";
-                break;
-        default:
-                break;
-        }
- out:
+	switch(err){
+	case -ENODEV:
+		err_msg = "Device doesn't exist";
+		break;
+	case -EBUSY:
+		err_msg = "Device is currently open";
+		break;
+	default:
+		break;
+	}
+out:
 	mconsole_reply(req, err_msg, err, 0);
 }
 
+static DEFINE_SPINLOCK(console_lock);
+static LIST_HEAD(clients);
+static char console_buf[MCONSOLE_MAX_DATA];
+static int console_index = 0;
+
+static void console_write(struct console *console, const char *string,
+			  unsigned len)
+{
+	struct list_head *ele;
+	int n;
+
+	if(list_empty(&clients))
+		return;
+
+	while(1){
+		n = min(len, ARRAY_SIZE(console_buf) - console_index);
+		strncpy(&console_buf[console_index], string, n);
+		console_index += n;
+		string += n;
+		len -= n;
+		if(len == 0)
+			return;
+
+		list_for_each(ele, &clients){
+			struct mconsole_entry *entry;
+
+			entry = list_entry(ele, struct mconsole_entry, list);
+			mconsole_reply_len(&entry->request, console_buf,
+					   console_index, 0, 1);
+		}
+
+		console_index = 0;
+	}
+}
+
+static struct console mc_console = { .name	= "mc",
+				     .write	= console_write,
+				     .flags	= CON_PRINTBUFFER | CON_ENABLED,
+				     .index	= -1 };
+
+static int mc_add_console(void)
+{
+	register_console(&mc_console);
+	return 0;
+}
+
+late_initcall(mc_add_console);
+
+static void with_console(struct mc_request *req, void (*proc)(void *),
+			 void *arg)
+{
+	struct mconsole_entry entry;
+	unsigned long flags;
+
+	INIT_LIST_HEAD(&entry.list);
+	entry.request = *req;
+	list_add(&entry.list, &clients);
+	spin_lock_irqsave(&console_lock, flags);
+
+	(*proc)(arg);
+
+	mconsole_reply_len(req, console_buf, console_index, 0, 0);
+	console_index = 0;
+
+	spin_unlock_irqrestore(&console_lock, flags);
+	list_del(&entry.list);
+}
+
 #ifdef CONFIG_MAGIC_SYSRQ
+static void sysrq_proc(void *arg)
+{
+	char *op = arg;
+
+	handle_sysrq(*op, &current->thread.regs, NULL);
+}
+
 void mconsole_sysrq(struct mc_request *req)
 {
 	char *ptr = req->request.data;
@@ -471,8 +546,13 @@ void mconsole_sysrq(struct mc_request *req)
 	ptr += strlen("sysrq");
 	while(isspace(*ptr)) ptr++;
 
-	mconsole_reply(req, "", 0, 0);
-	handle_sysrq(*ptr, &current->thread.regs, NULL);
+	/* With 'b', the system will shut down without a chance to reply,
+	 * so in this case, we reply first.
+	 */
+	if(*ptr == 'b')
+		mconsole_reply(req, "", 0, 0);
+
+	with_console(req, sysrq_proc, ptr);
 }
 #else
 void mconsole_sysrq(struct mc_request *req)
@@ -481,6 +561,14 @@ void mconsole_sysrq(struct mc_request *req)
 }
 #endif
 
+static void stack_proc(void *arg)
+{
+	struct task_struct *from = current, *to = arg;
+
+	to->thread.saved_task = from;
+	switch_to(from, to, from);
+}
+
 /* Mconsole stack trace
  *  Added by Allan Graves, Jeff Dike
  *  Dumps a stacks registers to the linux console.
@@ -488,37 +576,34 @@ void mconsole_sysrq(struct mc_request *req)
  */
 void do_stack(struct mc_request *req)
 {
-        char *ptr = req->request.data;
-        int pid_requested= -1;
-        struct task_struct *from = NULL;
+	char *ptr = req->request.data;
+	int pid_requested= -1;
+	struct task_struct *from = NULL;
 	struct task_struct *to = NULL;
 
-        /* Would be nice:
-         * 1) Send showregs output to mconsole.
+	/* Would be nice:
+	 * 1) Send showregs output to mconsole.
 	 * 2) Add a way to stack dump all pids.
 	 */
 
-        ptr += strlen("stack");
-        while(isspace(*ptr)) ptr++;
-
-        /* Should really check for multiple pids or reject bad args here */
-        /* What do the arguments in mconsole_reply mean? */
-        if(sscanf(ptr, "%d", &pid_requested) == 0){
-                mconsole_reply(req, "Please specify a pid", 1, 0);
-                return;
-        }
+	ptr += strlen("stack");
+	while(isspace(*ptr)) ptr++;
 
-        from = current;
-        to = find_task_by_pid(pid_requested);
+	/* Should really check for multiple pids or reject bad args here */
+	/* What do the arguments in mconsole_reply mean? */
+	if(sscanf(ptr, "%d", &pid_requested) == 0){
+		mconsole_reply(req, "Please specify a pid", 1, 0);
+		return;
+	}
 
-        if((to == NULL) || (pid_requested == 0)) {
-                mconsole_reply(req, "Couldn't find that pid", 1, 0);
-                return;
-        }
-        to->thread.saved_task = current;
+	from = current;
 
-        switch_to(from, to, from);
-        mconsole_reply(req, "Stack Dumped to console and message log", 0, 0);
+	to = find_task_by_pid(pid_requested);
+	if((to == NULL) || (pid_requested == 0)) {
+		mconsole_reply(req, "Couldn't find that pid", 1, 0);
+		return;
+	}
+	with_console(req, stack_proc, to);
 }
 
 void mconsole_stack(struct mc_request *req)
@@ -534,9 +619,9 @@ void mconsole_stack(struct mc_request *req)
 /* Changed by mconsole_setup, which is __setup, and called before SMP is
  * active.
  */
-static char *notify_socket = NULL; 
+static char *notify_socket = NULL;
 
-int mconsole_init(void)
+static int mconsole_init(void)
 {
 	/* long to avoid size mismatch warnings from gcc */
 	long sock;
@@ -563,16 +648,16 @@ int mconsole_init(void)
 	}
 
 	if(notify_socket != NULL){
-		notify_socket = uml_strdup(notify_socket);
+		notify_socket = kstrdup(notify_socket, GFP_KERNEL);
 		if(notify_socket != NULL)
 			mconsole_notify(notify_socket, MCONSOLE_SOCKET,
-					mconsole_socket_name, 
+					mconsole_socket_name,
 					strlen(mconsole_socket_name) + 1);
 		else printk(KERN_ERR "mconsole_setup failed to strdup "
 			    "string\n");
 	}
 
-	printk("mconsole (version %d) initialized on %s\n", 
+	printk("mconsole (version %d) initialized on %s\n",
 	       MCONSOLE_VERSION, mconsole_socket_name);
 	return(0);
 }
@@ -585,7 +670,7 @@ static int write_proc_mconsole(struct file *file, const char __user *buffer,
 	char *buf;
 
 	buf = kmalloc(count + 1, GFP_KERNEL);
-	if(buf == NULL) 
+	if(buf == NULL)
 		return(-ENOMEM);
 
 	if(copy_from_user(buf, buffer, count)){
@@ -661,7 +746,7 @@ static int notify_panic(struct notifier_block *self, unsigned long unused1,
 
 	if(notify_socket == NULL) return(0);
 
-	mconsole_notify(notify_socket, MCONSOLE_PANIC, message, 
+	mconsole_notify(notify_socket, MCONSOLE_PANIC, message,
 			strlen(message) + 1);
 	return(0);
 }
@@ -686,14 +771,3 @@ char *mconsole_notify_socket(void)
 }
 
 EXPORT_SYMBOL(mconsole_notify_socket);
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/drivers/mconsole_user.c b/arch/um/drivers/mconsole_user.c
index 310c1f823f2..4b109fe7fff 100644
--- a/arch/um/drivers/mconsole_user.c
+++ b/arch/um/drivers/mconsole_user.c
@@ -122,12 +122,12 @@ int mconsole_get_request(int fd, struct mc_request *req)
 	return(1);
 }
 
-int mconsole_reply(struct mc_request *req, char *str, int err, int more)
+int mconsole_reply_len(struct mc_request *req, const char *str, int total,
+		       int err, int more)
 {
 	struct mconsole_reply reply;
-	int total, len, n;
+	int len, n;
 
-	total = strlen(str);
 	do {
 		reply.err = err;
 
@@ -155,6 +155,12 @@ int mconsole_reply(struct mc_request *req, char *str, int err, int more)
 	return(0);
 }
 
+int mconsole_reply(struct mc_request *req, const char *str, int err, int more)
+{
+	return mconsole_reply_len(req, str, strlen(str), err, more);
+}
+
+
 int mconsole_unlink_socket(void)
 {
 	unlink(mconsole_socket_name);
diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
index 84c73a300ac..fb1f9fb9b87 100644
--- a/arch/um/drivers/net_kern.c
+++ b/arch/um/drivers/net_kern.c
@@ -34,7 +34,7 @@
 #define DRIVER_NAME "uml-netdev"
 
 static DEFINE_SPINLOCK(opened_lock);
-LIST_HEAD(opened);
+static LIST_HEAD(opened);
 
 static int uml_net_rx(struct net_device *dev)
 {
@@ -150,6 +150,7 @@ static int uml_net_close(struct net_device *dev)
 	if(lp->close != NULL)
 		(*lp->close)(lp->fd, &lp->user);
 	lp->fd = -1;
+	list_del(&lp->list);
 
 	spin_unlock(&lp->lock);
 	return 0;
@@ -266,7 +267,7 @@ void uml_net_user_timer_expire(unsigned long _conn)
 }
 
 static DEFINE_SPINLOCK(devices_lock);
-static struct list_head devices = LIST_HEAD_INIT(devices);
+static LIST_HEAD(devices);
 
 static struct platform_driver uml_net_driver = {
 	.driver = {
@@ -586,7 +587,7 @@ static int net_config(char *str)
 	err = eth_parse(str, &n, &str);
 	if(err) return(err);
 
-	str = uml_strdup(str);
+	str = kstrdup(str, GFP_KERNEL);
 	if(str == NULL){
 		printk(KERN_ERR "net_config failed to strdup string\n");
 		return(-1);
@@ -715,6 +716,7 @@ static void close_devices(void)
 
 	list_for_each(ele, &opened){
 		lp = list_entry(ele, struct uml_net_private, list);
+		free_irq(lp->dev->irq, lp->dev);
 		if((lp->close != NULL) && (lp->fd >= 0))
 			(*lp->close)(lp->fd, &lp->user);
 		if(lp->remove != NULL) (*lp->remove)(&lp->user);
diff --git a/arch/um/drivers/ssl.c b/arch/um/drivers/ssl.c
index 62e04ecfada..a32ef55cb24 100644
--- a/arch/um/drivers/ssl.c
+++ b/arch/um/drivers/ssl.c
@@ -69,7 +69,7 @@ static struct line_driver driver = {
 		.name  		= "ssl",
 		.config 	= ssl_config,
 		.get_config 	= ssl_get_config,
-                .id		= line_id,
+		.id		= line_id,
 		.remove 	= ssl_remove,
 	},
 };
@@ -84,26 +84,23 @@ static struct lines lines = LINES_INIT(NR_PORTS);
 
 static int ssl_config(char *str)
 {
-	return(line_config(serial_lines, 
-			   sizeof(serial_lines)/sizeof(serial_lines[0]), str));
+	return line_config(serial_lines, ARRAY_SIZE(serial_lines), str, &opts);
 }
 
 static int ssl_get_config(char *dev, char *str, int size, char **error_out)
 {
-	return(line_get_config(dev, serial_lines, 
-			       sizeof(serial_lines)/sizeof(serial_lines[0]), 
-			       str, size, error_out));
+	return line_get_config(dev, serial_lines, ARRAY_SIZE(serial_lines), str,
+			       size, error_out);
 }
 
 static int ssl_remove(int n)
 {
-        return line_remove(serial_lines,
-                           sizeof(serial_lines)/sizeof(serial_lines[0]), n);
+	return line_remove(serial_lines, ARRAY_SIZE(serial_lines), n);
 }
 
 int ssl_open(struct tty_struct *tty, struct file *filp)
 {
-	return line_open(serial_lines, tty, &opts);
+	return line_open(serial_lines, tty);
 }
 
 #if 0
@@ -112,16 +109,6 @@ static void ssl_flush_buffer(struct tty_struct *tty)
 	return;
 }
 
-static void ssl_throttle(struct tty_struct * tty)
-{
-	printk(KERN_ERR "Someone should implement ssl_throttle\n");
-}
-
-static void ssl_unthrottle(struct tty_struct * tty)
-{
-	printk(KERN_ERR "Someone should implement ssl_unthrottle\n");
-}
-
 static void ssl_stop(struct tty_struct *tty)
 {
 	printk(KERN_ERR "Someone should implement ssl_stop\n");
@@ -148,9 +135,9 @@ static struct tty_operations ssl_ops = {
 	.flush_chars 		= line_flush_chars,
 	.set_termios 		= line_set_termios,
 	.ioctl 	 		= line_ioctl,
+	.throttle 		= line_throttle,
+	.unthrottle 		= line_unthrottle,
 #if 0
-	.throttle 		= ssl_throttle,
-	.unthrottle 		= ssl_unthrottle,
 	.stop 	 		= ssl_stop,
 	.start 	 		= ssl_start,
 	.hangup 	 	= ssl_hangup,
@@ -183,7 +170,7 @@ static int ssl_console_setup(struct console *co, char *options)
 {
 	struct line *line = &serial_lines[co->index];
 
-	return console_open_chan(line,co,&opts);
+	return console_open_chan(line, co, &opts);
 }
 
 static struct console ssl_cons = {
@@ -199,12 +186,13 @@ int ssl_init(void)
 {
 	char *new_title;
 
-	printk(KERN_INFO "Initializing software serial port version %d\n", 
+	printk(KERN_INFO "Initializing software serial port version %d\n",
 	       ssl_version);
 	ssl_driver = line_register_devfs(&lines, &driver, &ssl_ops,
-					 serial_lines, ARRAY_SIZE(serial_lines));
+					 serial_lines,
+					 ARRAY_SIZE(serial_lines));
 
-	lines_init(serial_lines, sizeof(serial_lines)/sizeof(serial_lines[0]));
+	lines_init(serial_lines, ARRAY_SIZE(serial_lines), &opts);
 
 	new_title = add_xterm_umid(opts.xterm_title);
 	if (new_title != NULL)
@@ -212,7 +200,7 @@ int ssl_init(void)
 
 	ssl_init_done = 1;
 	register_console(&ssl_cons);
-	return(0);
+	return 0;
 }
 late_initcall(ssl_init);
 
@@ -220,16 +208,13 @@ static void ssl_exit(void)
 {
 	if (!ssl_init_done)
 		return;
-	close_lines(serial_lines,
-		    sizeof(serial_lines)/sizeof(serial_lines[0]));
+	close_lines(serial_lines, ARRAY_SIZE(serial_lines));
 }
 __uml_exitcall(ssl_exit);
 
 static int ssl_chan_setup(char *str)
 {
-	return(line_setup(serial_lines,
-			  sizeof(serial_lines)/sizeof(serial_lines[0]),
-			  str, 1));
+	return line_setup(serial_lines, ARRAY_SIZE(serial_lines), str);
 }
 
 __setup("ssl", ssl_chan_setup);
diff --git a/arch/um/drivers/stdio_console.c b/arch/um/drivers/stdio_console.c
index 005aa6333b6..61db8b2fc83 100644
--- a/arch/um/drivers/stdio_console.c
+++ b/arch/um/drivers/stdio_console.c
@@ -75,7 +75,7 @@ static struct line_driver driver = {
 		.name  		= "con",
 		.config 	= con_config,
 		.get_config 	= con_get_config,
-                .id		= line_id,
+		.id		= line_id,
 		.remove 	= con_remove,
 	},
 };
@@ -86,28 +86,27 @@ static struct lines console_lines = LINES_INIT(MAX_TTYS);
  * individual elements are protected by individual semaphores.
  */
 struct line vts[MAX_TTYS] = { LINE_INIT(CONFIG_CON_ZERO_CHAN, &driver),
-			      [ 1 ... MAX_TTYS - 1 ] = 
+			      [ 1 ... MAX_TTYS - 1 ] =
 			      LINE_INIT(CONFIG_CON_CHAN, &driver) };
 
 static int con_config(char *str)
 {
-	return(line_config(vts, sizeof(vts)/sizeof(vts[0]), str));
+	return line_config(vts, ARRAY_SIZE(vts), str, &opts);
 }
 
 static int con_get_config(char *dev, char *str, int size, char **error_out)
 {
-	return(line_get_config(dev, vts, sizeof(vts)/sizeof(vts[0]), str, 
-			       size, error_out));
+	return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out);
 }
 
 static int con_remove(int n)
 {
-        return line_remove(vts, sizeof(vts)/sizeof(vts[0]), n);
+	return line_remove(vts, ARRAY_SIZE(vts), n);
 }
 
 static int con_open(struct tty_struct *tty, struct file *filp)
 {
-	return line_open(vts, tty, &opts);
+	return line_open(vts, tty);
 }
 
 static int con_init_done = 0;
@@ -117,16 +116,18 @@ static struct tty_operations console_ops = {
 	.close 	 		= line_close,
 	.write 	 		= line_write,
 	.put_char 		= line_put_char,
- 	.write_room		= line_write_room,
+	.write_room		= line_write_room,
 	.chars_in_buffer 	= line_chars_in_buffer,
 	.flush_buffer 		= line_flush_buffer,
 	.flush_chars 		= line_flush_chars,
 	.set_termios 		= line_set_termios,
 	.ioctl 	 		= line_ioctl,
+	.throttle 		= line_throttle,
+	.unthrottle 		= line_unthrottle,
 };
 
 static void uml_console_write(struct console *console, const char *string,
-			  unsigned len)
+			      unsigned len)
 {
 	struct line *line = &vts[console->index];
 	unsigned long flags;
@@ -146,7 +147,7 @@ static int uml_console_setup(struct console *co, char *options)
 {
 	struct line *line = &vts[co->index];
 
-	return console_open_chan(line,co,&opts);
+	return console_open_chan(line, co, &opts);
 }
 
 static struct console stdiocons = {
@@ -156,7 +157,7 @@ static struct console stdiocons = {
 	.setup		= uml_console_setup,
 	.flags		= CON_PRINTBUFFER,
 	.index		= -1,
-	.data           = &vts,
+	.data		= &vts,
 };
 
 int stdio_init(void)
@@ -166,11 +167,11 @@ int stdio_init(void)
 	console_driver = line_register_devfs(&console_lines, &driver,
 					     &console_ops, vts,
 					     ARRAY_SIZE(vts));
-	if (NULL == console_driver)
+	if (console_driver == NULL)
 		return -1;
 	printk(KERN_INFO "Initialized stdio console driver\n");
 
-	lines_init(vts, sizeof(vts)/sizeof(vts[0]));
+	lines_init(vts, ARRAY_SIZE(vts), &opts);
 
 	new_title = add_xterm_umid(opts.xterm_title);
 	if(new_title != NULL)
@@ -178,7 +179,7 @@ int stdio_init(void)
 
 	con_init_done = 1;
 	register_console(&stdiocons);
-	return(0);
+	return 0;
 }
 late_initcall(stdio_init);
 
@@ -186,13 +187,13 @@ static void console_exit(void)
 {
 	if (!con_init_done)
 		return;
-	close_lines(vts, sizeof(vts)/sizeof(vts[0]));
+	close_lines(vts, ARRAY_SIZE(vts));
 }
 __uml_exitcall(console_exit);
 
 static int console_chan_setup(char *str)
 {
-	return(line_setup(vts, sizeof(vts)/sizeof(vts[0]), str, 1));
+	return line_setup(vts, ARRAY_SIZE(vts), str);
 }
 __setup("con", console_chan_setup);
 __channel_help(console_chan_setup, "con");
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 93898917cbe..73f9652b2ee 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -706,7 +706,7 @@ static int ubd_config(char *str)
 {
 	int n, err;
 
-	str = uml_strdup(str);
+	str = kstrdup(str, GFP_KERNEL);
 	if(str == NULL){
 		printk(KERN_ERR "ubd_config failed to strdup string\n");
 		return(1);
@@ -1387,15 +1387,6 @@ int io_thread(void *arg)
 			printk("io_thread - write failed, fd = %d, err = %d\n",
 			       kernel_fd, -n);
 	}
-}
 
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
+	return 0;
+}
diff --git a/arch/um/include/chan_kern.h b/arch/um/include/chan_kern.h
index da9a6717e7a..1bb5e9d9427 100644
--- a/arch/um/include/chan_kern.h
+++ b/arch/um/include/chan_kern.h
@@ -14,21 +14,23 @@
 
 struct chan {
 	struct list_head list;
+	struct list_head free_list;
+	struct line *line;
 	char *dev;
 	unsigned int primary:1;
 	unsigned int input:1;
 	unsigned int output:1;
 	unsigned int opened:1;
+	unsigned int enabled:1;
 	int fd;
-	enum chan_init_pri pri;
 	struct chan_ops *ops;
 	void *data;
 };
 
 extern void chan_interrupt(struct list_head *chans, struct work_struct *task,
 			   struct tty_struct *tty, int irq);
-extern int parse_chan_pair(char *str, struct list_head *chans, int pri, 
-			   int device, struct chan_opts *opts);
+extern int parse_chan_pair(char *str, struct line *line, int device,
+			   struct chan_opts *opts);
 extern int open_chan(struct list_head *chans);
 extern int write_chan(struct list_head *chans, const char *buf, int len,
 			     int write_irq);
@@ -36,9 +38,11 @@ extern int console_write_chan(struct list_head *chans, const char *buf,
 			      int len);
 extern int console_open_chan(struct line *line, struct console *co,
 			     struct chan_opts *opts);
-extern void close_chan(struct list_head *chans);
+extern void deactivate_chan(struct list_head *chans, int irq);
+extern void reactivate_chan(struct list_head *chans, int irq);
 extern void chan_enable_winch(struct list_head *chans, struct tty_struct *tty);
-extern void enable_chan(struct list_head *chans, struct tty_struct *tty);
+extern void enable_chan(struct line *line);
+extern void close_chan(struct list_head *chans, int delay_free_irq);
 extern int chan_window_size(struct list_head *chans, 
 			     unsigned short *rows_out, 
 			     unsigned short *cols_out);
@@ -47,14 +51,3 @@ extern int chan_config_string(struct list_head *chans, char *str, int size,
 			      char **error_out);
 
 #endif
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/include/choose-mode.h b/arch/um/include/choose-mode.h
index f25fa83a5da..b87b36a87d9 100644
--- a/arch/um/include/choose-mode.h
+++ b/arch/um/include/choose-mode.h
@@ -23,6 +23,9 @@ static inline void *__choose_mode(void *tt, void *skas) {
 
 #elif defined(UML_CONFIG_MODE_TT)
 #define CHOOSE_MODE(tt, skas) (tt)
+
+#else
+#error CONFIG_MODE_SKAS and CONFIG_MODE_TT are both disabled
 #endif
 
 #define CHOOSE_MODE_PROC(tt, skas, args...) \
diff --git a/arch/um/include/irq_user.h b/arch/um/include/irq_user.h
index f724b717213..b61deb8b362 100644
--- a/arch/um/include/irq_user.h
+++ b/arch/um/include/irq_user.h
@@ -18,19 +18,8 @@ extern int deactivate_all_fds(void);
 extern void forward_interrupts(int pid);
 extern void init_irq_signals(int on_sigstack);
 extern void forward_ipi(int fd, int pid);
-extern void free_irq_later(int irq, void *dev_id);
 extern int activate_ipi(int fd, int pid);
 extern unsigned long irq_lock(void);
 extern void irq_unlock(unsigned long flags);
-#endif
 
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
+#endif
diff --git a/arch/um/include/kern.h b/arch/um/include/kern.h
index 1e3170768b5..7d223beccbc 100644
--- a/arch/um/include/kern.h
+++ b/arch/um/include/kern.h
@@ -17,7 +17,7 @@ extern int errno;
 
 extern int clone(int (*proc)(void *), void *sp, int flags, void *data);
 extern int sleep(int);
-extern int printf(char *fmt, ...);
+extern int printf(const char *fmt, ...);
 extern char *strerror(int errnum);
 extern char *ptsname(int __fd);
 extern int munmap(void *, int);
@@ -35,15 +35,6 @@ extern int read(unsigned int, char *, int);
 extern int pipe(int *);
 extern int sched_yield(void);
 extern int ptrace(int op, int pid, long addr, long data);
+
 #endif
 
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/include/line.h b/arch/um/include/line.h
index 5323d22a6ca..6f4d680dc1d 100644
--- a/arch/um/include/line.h
+++ b/arch/um/include/line.h
@@ -32,11 +32,13 @@ struct line_driver {
 };
 
 struct line {
+	struct tty_struct *tty;
 	char *init_str;
 	int init_pri;
 	struct list_head chan_list;
 	int valid;
 	int count;
+	int throttled;
 	/*This lock is actually, mostly, local to*/
 	spinlock_t lock;
 
@@ -58,14 +60,15 @@ struct line {
 #define LINE_INIT(str, d) \
 	{ init_str :	str, \
 	  init_pri :	INIT_STATIC, \
-	  chan_list : 	{ }, \
 	  valid :	1, \
+	  throttled :	0, \
+	  lock :	SPIN_LOCK_UNLOCKED, \
 	  buffer :	NULL, \
 	  head :	NULL, \
 	  tail :	NULL, \
 	  sigio :	0, \
- 	  driver :	d, \
-          have_irq :	0 }
+	  driver :	d, \
+	  have_irq :	0 }
 
 struct lines {
 	int num;
@@ -74,11 +77,11 @@ struct lines {
 #define LINES_INIT(n) {  num :		n }
 
 extern void line_close(struct tty_struct *tty, struct file * filp);
-extern int line_open(struct line *lines, struct tty_struct *tty, 
-		     struct chan_opts *opts);
-extern int line_setup(struct line *lines, unsigned int sizeof_lines, char *init,
-		      int all_allowed);
-extern int line_write(struct tty_struct *tty, const unsigned char *buf, int len);
+extern int line_open(struct line *lines, struct tty_struct *tty);
+extern int line_setup(struct line *lines, unsigned int sizeof_lines,
+		      char *init);
+extern int line_write(struct tty_struct *tty, const unsigned char *buf,
+		      int len);
 extern void line_put_char(struct tty_struct *tty, unsigned char ch);
 extern void line_set_termios(struct tty_struct *tty, struct termios * old);
 extern int line_chars_in_buffer(struct tty_struct *tty);
@@ -87,23 +90,27 @@ extern void line_flush_chars(struct tty_struct *tty);
 extern int line_write_room(struct tty_struct *tty);
 extern int line_ioctl(struct tty_struct *tty, struct file * file,
 		      unsigned int cmd, unsigned long arg);
+extern void line_throttle(struct tty_struct *tty);
+extern void line_unthrottle(struct tty_struct *tty);
 
 extern char *add_xterm_umid(char *base);
-extern int line_setup_irq(int fd, int input, int output, struct tty_struct *tty);
+extern int line_setup_irq(int fd, int input, int output, struct line *line,
+			  void *data);
 extern void line_close_chan(struct line *line);
-extern void line_disable(struct tty_struct *tty, int current_irq);
-extern struct tty_driver * line_register_devfs(struct lines *set, 
-				struct line_driver *line_driver, 
+extern struct tty_driver * line_register_devfs(struct lines *set,
+				struct line_driver *line_driver,
 				struct tty_operations *driver,
 				struct line *lines,
 				int nlines);
-extern void lines_init(struct line *lines, int nlines);
+extern void lines_init(struct line *lines, int nlines, struct chan_opts *opts);
 extern void close_lines(struct line *lines, int nlines);
 
-extern int line_config(struct line *lines, unsigned int sizeof_lines, char *str);
+extern int line_config(struct line *lines, unsigned int sizeof_lines,
+		       char *str, struct chan_opts *opts);
 extern int line_id(char **str, int *start_out, int *end_out);
 extern int line_remove(struct line *lines, unsigned int sizeof_lines, int n);
-extern int line_get_config(char *dev, struct line *lines, unsigned int sizeof_lines, char *str,
+extern int line_get_config(char *dev, struct line *lines,
+			   unsigned int sizeof_lines, char *str,
 			   int size, char **error_out);
 
 #endif
diff --git a/arch/um/include/mconsole.h b/arch/um/include/mconsole.h
index b1b512f4703..58f67d39110 100644
--- a/arch/um/include/mconsole.h
+++ b/arch/um/include/mconsole.h
@@ -32,7 +32,7 @@ struct mconsole_reply {
 
 struct mconsole_notify {
 	u32 magic;
-	u32 version;	
+	u32 version;
 	enum { MCONSOLE_SOCKET, MCONSOLE_PANIC, MCONSOLE_HANG,
 	       MCONSOLE_USER_NOTIFY } type;
 	u32 len;
@@ -66,7 +66,9 @@ struct mc_request
 extern char mconsole_socket_name[];
 
 extern int mconsole_unlink_socket(void);
-extern int mconsole_reply(struct mc_request *req, char *reply, int err,
+extern int mconsole_reply_len(struct mc_request *req, const char *reply,
+			      int len, int err, int more);
+extern int mconsole_reply(struct mc_request *req, const char *str, int err,
 			  int more);
 
 extern void mconsole_version(struct mc_request *req);
@@ -84,7 +86,7 @@ extern void mconsole_proc(struct mc_request *req);
 extern void mconsole_stack(struct mc_request *req);
 
 extern int mconsole_get_request(int fd, struct mc_request *req);
-extern int mconsole_notify(char *sock_name, int type, const void *data, 
+extern int mconsole_notify(char *sock_name, int type, const void *data,
 			   int len);
 extern char *mconsole_notify_socket(void);
 extern void lock_notify(void);
diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index 2cccfa5b8ab..c279ee6d89e 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -213,15 +213,10 @@ extern int run_helper_thread(int (*proc)(void *), void *arg,
 			     int stack_order);
 extern int helper_wait(int pid);
 
-#endif
+/* umid.c */
 
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
+extern int umid_file_name(char *name, char *buf, int len);
+extern int set_umid(char *name);
+extern char *get_umid(void);
+
+#endif
diff --git a/arch/um/include/user_util.h b/arch/um/include/user_util.h
index bb505e01d99..b9984003e60 100644
--- a/arch/um/include/user_util.h
+++ b/arch/um/include/user_util.h
@@ -64,7 +64,6 @@ extern void setup_machinename(char *machine_out);
 extern void setup_hostinfo(void);
 extern void do_exec(int old_pid, int new_pid);
 extern void tracer_panic(char *msg, ...);
-extern char *get_umid(int only_if_set);
 extern void do_longjmp(void *p, int val);
 extern int detach(int pid, int sig);
 extern int attach(int pid);
diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile
index 3de9d21e36b..6f7700593a6 100644
--- a/arch/um/kernel/Makefile
+++ b/arch/um/kernel/Makefile
@@ -10,8 +10,8 @@ obj-y = config.o exec_kern.o exitcode.o \
 	init_task.o irq.o irq_user.o ksyms.o mem.o physmem.o \
 	process_kern.o ptrace.o reboot.o resource.o sigio_user.o sigio_kern.o \
 	signal_kern.o signal_user.o smp.o syscall_kern.o sysrq.o time.o \
-	time_kern.o tlb.o trap_kern.o trap_user.o uaccess.o um_arch.o \
-	umid.o user_util.o
+	time_kern.o tlb.o trap_kern.o trap_user.o uaccess.o um_arch.o umid.o \
+	user_util.o
 
 obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o
 obj-$(CONFIG_GPROF)	+= gprof_syms.o
@@ -24,7 +24,7 @@ obj-$(CONFIG_MODE_SKAS) += skas/
 
 user-objs-$(CONFIG_TTY_LOG) += tty_log.o
 
-USER_OBJS := $(user-objs-y) config.o time.o tty_log.o umid.o user_util.o
+USER_OBJS := $(user-objs-y) config.o time.o tty_log.o user_util.o
 
 include arch/um/scripts/Makefile.rules
 
diff --git a/arch/um/kernel/irq_user.c b/arch/um/kernel/irq_user.c
index c3ccaf24f3e..50a2aa35cda 100644
--- a/arch/um/kernel/irq_user.c
+++ b/arch/um/kernel/irq_user.c
@@ -29,7 +29,6 @@ struct irq_fd {
 	int pid;
 	int events;
 	int current_events;
-	int freed;
 };
 
 static struct irq_fd *active_fds = NULL;
@@ -41,9 +40,11 @@ static int pollfds_size = 0;
 
 extern int io_count, intr_count;
 
+extern void free_irqs(void);
+
 void sigio_handler(int sig, union uml_pt_regs *regs)
 {
-	struct irq_fd *irq_fd, *next;
+	struct irq_fd *irq_fd;
 	int i, n;
 
 	if(smp_sigio_handler()) return;
@@ -66,29 +67,15 @@ void sigio_handler(int sig, union uml_pt_regs *regs)
 			irq_fd = irq_fd->next;
 		}
 
-		for(irq_fd = active_fds; irq_fd != NULL; irq_fd = next){
-			next = irq_fd->next;
+		for(irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next){
 			if(irq_fd->current_events != 0){
 				irq_fd->current_events = 0;
 				do_IRQ(irq_fd->irq, regs);
-
-				/* This is here because the next irq may be
-				 * freed in the handler.  If a console goes
-				 * away, both the read and write irqs will be
-				 * freed.  After do_IRQ, ->next will point to
-				 * a good IRQ.
-				 * Irqs can't be freed inside their handlers,
-				 * so the next best thing is to have them
-				 * marked as needing freeing, so that they
-				 * can be freed here.
-				 */
-				next = irq_fd->next;
-				if(irq_fd->freed){
-					free_irq(irq_fd->irq, irq_fd->id);
-				}
 			}
 		}
 	}
+
+	free_irqs();
 }
 
 int activate_ipi(int fd, int pid)
@@ -136,8 +123,7 @@ int activate_fd(int irq, int fd, int type, void *dev_id)
 				     .irq 		= irq,
 				     .pid  		= pid,
 				     .events 		= events,
-				     .current_events 	= 0,
-				     .freed 		= 0  } );
+				     .current_events 	= 0 } );
 
 	/* Critical section - locked by a spinlock because this stuff can
 	 * be changed from interrupt handlers.  The stuff above is done 
@@ -313,26 +299,6 @@ static struct irq_fd *find_irq_by_fd(int fd, int irqnum, int *index_out)
 	return(irq);
 }
 
-void free_irq_later(int irq, void *dev_id)
-{
-	struct irq_fd *irq_fd;
-	unsigned long flags;
-
-	flags = irq_lock();
-	for(irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next){
-		if((irq_fd->irq == irq) && (irq_fd->id == dev_id))
-			break;
-	}
-	if(irq_fd == NULL){
-		printk("free_irq_later found no irq, irq = %d, "
-		       "dev_id = 0x%p\n", irq, dev_id);
-		goto out;
-	}
-	irq_fd->freed = 1;
- out:
-	irq_unlock(flags);
-}
-
 void reactivate_fd(int fd, int irqnum)
 {
 	struct irq_fd *irq;
diff --git a/arch/um/kernel/process_kern.c b/arch/um/kernel/process_kern.c
index 34b54a3e213..651abf255bc 100644
--- a/arch/um/kernel/process_kern.c
+++ b/arch/um/kernel/process_kern.c
@@ -324,10 +324,6 @@ int user_context(unsigned long sp)
 	return(stack != (unsigned long) current_thread);
 }
 
-extern void remove_umid_dir(void);
-
-__uml_exitcall(remove_umid_dir);
-
 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
 
 void do_uml_exitcalls(void)
diff --git a/arch/um/kernel/sigio_user.c b/arch/um/kernel/sigio_user.c
index 48b1f644b9a..62e5cfdf218 100644
--- a/arch/um/kernel/sigio_user.c
+++ b/arch/um/kernel/sigio_user.c
@@ -216,6 +216,8 @@ static int write_sigio_thread(void *unused)
 				       "err = %d\n", -n);
 		}
 	}
+
+	return 0;
 }
 
 static int need_poll(int n)
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 142a9493912..26626b2b917 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -146,8 +146,8 @@ void set_cmdline(char *cmd)
 
 	if(CHOOSE_MODE(honeypot, 0)) return;
 
-	umid = get_umid(1);
-	if(umid != NULL){
+	umid = get_umid();
+	if(*umid != '\0'){
 		snprintf(argv1_begin, 
 			 (argv1_end - argv1_begin) * sizeof(*ptr), 
 			 "(%s) ", umid);
diff --git a/arch/um/kernel/umid.c b/arch/um/kernel/umid.c
index 0b21d59ba0c..4eaee823bfd 100644
--- a/arch/um/kernel/umid.c
+++ b/arch/um/kernel/umid.c
@@ -3,61 +3,30 @@
  * Licensed under the GPL
  */
 
-#include <stdio.h>
-#include <unistd.h>
-#include <errno.h>
-#include <string.h>
-#include <stdlib.h>
-#include <dirent.h>
-#include <signal.h>
-#include <sys/stat.h>
-#include <sys/param.h>
-#include "user.h"
-#include "umid.h"
+#include "asm/errno.h"
 #include "init.h"
 #include "os.h"
-#include "user_util.h"
-#include "choose-mode.h"
+#include "kern.h"
+#include "linux/kernel.h"
 
-#define UMID_LEN 64
-#define UML_DIR "~/.uml/"
-
-/* Changed by set_umid and make_umid, which are run early in boot */
-static char umid[UMID_LEN] = { 0 };
-
-/* Changed by set_uml_dir and make_uml_dir, which are run early in boot */
-static char *uml_dir = UML_DIR;
-
-/* Changed by set_umid */
-static int umid_is_random = 1;
+/* Changed by set_umid_arg */
 static int umid_inited = 0;
-/* Have we created the files? Should we remove them? */
-static int umid_owned = 0;
 
-static int make_umid(int (*printer)(const char *fmt, ...));
-
-static int __init set_umid(char *name, int is_random,
-			   int (*printer)(const char *fmt, ...))
+static int __init set_umid_arg(char *name, int *add)
 {
-	if(umid_inited){
-		(*printer)("Unique machine name can't be set twice\n");
-		return(-1);
-	}
+	int err;
 
-	if(strlen(name) > UMID_LEN - 1)
-		(*printer)("Unique machine name is being truncated to %d "
-			   "characters\n", UMID_LEN);
-	strlcpy(umid, name, sizeof(umid));
+	if(umid_inited)
+		return 0;
 
-	umid_is_random = is_random;
-	umid_inited = 1;
-	return 0;
-}
-
-static int __init set_umid_arg(char *name, int *add)
-{
 	*add = 0;
-	return(set_umid(name, 0, printf));
+	err = set_umid(name);
+	if(err == -EEXIST)
+		printf("umid '%s' already in use\n", name);
+	else if(!err)
+		umid_inited = 1;
+
+	return 0;
 }
 
 __uml_setup("umid=", set_umid_arg,
@@ -66,265 +35,3 @@ __uml_setup("umid=", set_umid_arg,
 "    is used for naming the pid file and management console socket.\n\n"
 );
 
-int __init umid_file_name(char *name, char *buf, int len)
-{
-	int n;
-
-	if(!umid_inited && make_umid(printk)) return(-1);
-
-	n = strlen(uml_dir) + strlen(umid) + strlen(name) + 1;
-	if(n > len){
-		printk("umid_file_name : buffer too short\n");
-		return(-1);
-	}
-
-	sprintf(buf, "%s%s/%s", uml_dir, umid, name);
-	return(0);
-}
-
-extern int tracing_pid;
-
-static void __init create_pid_file(void)
-{
-	char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")];
-	char pid[sizeof("nnnnn\0")];
-	int fd, n;
-
-	if(umid_file_name("pid", file, sizeof(file)))
-		return;
-
-	fd = os_open_file(file, of_create(of_excl(of_rdwr(OPENFLAGS()))), 
-			  0644);
-	if(fd < 0){
-		printf("Open of machine pid file \"%s\" failed: %s\n",
-		       file, strerror(-fd));
-		return;
-	}
-
-	sprintf(pid, "%d\n", os_getpid());
-	n = os_write_file(fd, pid, strlen(pid));
-	if(n != strlen(pid))
-		printf("Write of pid file failed - err = %d\n", -n);
-	os_close_file(fd);
-}
-
-static int actually_do_remove(char *dir)
-{
-	DIR *directory;
-	struct dirent *ent;
-	int len;
-	char file[256];
-
-	directory = opendir(dir);
-	if(directory == NULL){
-		printk("actually_do_remove : couldn't open directory '%s', "
-		       "errno = %d\n", dir, errno);
-		return(1);
-	}
-	while((ent = readdir(directory)) != NULL){
-		if(!strcmp(ent->d_name, ".") || !strcmp(ent->d_name, ".."))
-			continue;
-		len = strlen(dir) + sizeof("/") + strlen(ent->d_name) + 1;
-		if(len > sizeof(file)){
-			printk("Not deleting '%s' from '%s' - name too long\n",
-			       ent->d_name, dir);
-			continue;
-		}
-		sprintf(file, "%s/%s", dir, ent->d_name);
-		if(unlink(file) < 0){
-			printk("actually_do_remove : couldn't remove '%s' "
-			       "from '%s', errno = %d\n", ent->d_name, dir, 
-			       errno);
-			return(1);
-		}
-	}
-	if(rmdir(dir) < 0){
-		printk("actually_do_remove : couldn't rmdir '%s', "
-		       "errno = %d\n", dir, errno);
-		return(1);
-	}
-	return(0);
-}
-
-void remove_umid_dir(void)
-{
-	char dir[strlen(uml_dir) + UMID_LEN + 1];
-	if (!umid_owned)
-		return;
-
-	sprintf(dir, "%s%s", uml_dir, umid);
-	actually_do_remove(dir);
-}
-
-char *get_umid(int only_if_set)
-{
-	if(only_if_set && umid_is_random)
-		return NULL;
-	return umid;
-}
-
-static int not_dead_yet(char *dir)
-{
-	char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")];
-	char pid[sizeof("nnnnn\0")], *end;
-	int dead, fd, p, n;
-
-	sprintf(file, "%s/pid", dir);
-	dead = 0;
-	fd = os_open_file(file, of_read(OPENFLAGS()), 0);
-	if(fd < 0){
-		if(fd != -ENOENT){
-			printk("not_dead_yet : couldn't open pid file '%s', "
-			       "err = %d\n", file, -fd);
-			return(1);
-		}
-		dead = 1;
-	}
-	if(fd > 0){
-		n = os_read_file(fd, pid, sizeof(pid));
-		if(n < 0){
-			printk("not_dead_yet : couldn't read pid file '%s', "
-			       "err = %d\n", file, -n);
-			return(1);
-		}
-		p = strtoul(pid, &end, 0);
-		if(end == pid){
-			printk("not_dead_yet : couldn't parse pid file '%s', "
-			       "errno = %d\n", file, errno);
-			dead = 1;
-		}
-		if(((kill(p, 0) < 0) && (errno == ESRCH)) ||
-		   (p == CHOOSE_MODE(tracing_pid, os_getpid())))
-			dead = 1;
-	}
-	if(!dead)
-		return(1);
-	return(actually_do_remove(dir));
-}
-
-static int __init set_uml_dir(char *name, int *add)
-{
-	if((strlen(name) > 0) && (name[strlen(name) - 1] != '/')){
-		uml_dir = malloc(strlen(name) + 2);
-		if(uml_dir == NULL){
-			printf("Failed to malloc uml_dir - error = %d\n",
-			       errno);
-			uml_dir = name;
-			/* Return 0 here because do_initcalls doesn't look at
-			 * the return value.
-			 */
-			return(0);
-		}
-		sprintf(uml_dir, "%s/", name);
-	}
-	else uml_dir = name;
-	return(0);
-}
-
-static int __init make_uml_dir(void)
-{
-	char dir[MAXPATHLEN + 1] = { '\0' };
-	int len;
-
-	if(*uml_dir == '~'){
-		char *home = getenv("HOME");
-
-		if(home == NULL){
-			printf("make_uml_dir : no value in environment for "
-			       "$HOME\n");
-			exit(1);
-		}
-		strlcpy(dir, home, sizeof(dir));
-		uml_dir++;
-	}
-	strlcat(dir, uml_dir, sizeof(dir));
-	len = strlen(dir);
-	if (len > 0 && dir[len - 1] != '/')
-		strlcat(dir, "/", sizeof(dir));
-
-	uml_dir = malloc(strlen(dir) + 1);
-	if (uml_dir == NULL) {
-		printf("make_uml_dir : malloc failed, errno = %d\n", errno);
-		exit(1);
-	}
-	strcpy(uml_dir, dir);
-	
-	if((mkdir(uml_dir, 0777) < 0) && (errno != EEXIST)){
-	        printf("Failed to mkdir %s: %s\n", uml_dir, strerror(errno));
-		return(-1);
-	}
-	return 0;
-}
-
-static int __init make_umid(int (*printer)(const char *fmt, ...))
-{
-	int fd, err;
-	char tmp[strlen(uml_dir) + UMID_LEN + 1];
-
-	strlcpy(tmp, uml_dir, sizeof(tmp));
-
-	if(!umid_inited){
-		strcat(tmp, "XXXXXX");
-		fd = mkstemp(tmp);
-		if(fd < 0){
-			(*printer)("make_umid - mkstemp(%s) failed: %s\n",
-				   tmp,strerror(errno));
-			return(1);
-		}
-
-		os_close_file(fd);
-		/* There's a nice tiny little race between this unlink and
-		 * the mkdir below.  It'd be nice if there were a mkstemp
-		 * for directories.
-		 */
-		unlink(tmp);
-		set_umid(&tmp[strlen(uml_dir)], 1, printer);
-	}
-	
-	sprintf(tmp, "%s%s", uml_dir, umid);
-
-	err = mkdir(tmp, 0777);
-	if(err < 0){
-		if(errno == EEXIST){
-			if(not_dead_yet(tmp)){
-				(*printer)("umid '%s' is in use\n", umid);
-				umid_owned = 0;
-				return(-1);
-			}
-			err = mkdir(tmp, 0777);
-		}
-	}
-	if(err < 0){
-		(*printer)("Failed to create %s - errno = %d\n", umid, errno);
-		return(-1);
-	}
-
-	umid_owned = 1;
-	return 0;
-}
-
-__uml_setup("uml_dir=", set_uml_dir,
-"uml_dir=<directory>\n"
-"    The location to place the pid and umid files.\n\n"
-);
-
-static int __init make_umid_setup(void)
-{
-	/* one function with the ordering we need ... */
-	make_uml_dir();
-	make_umid(printf);
-	create_pid_file();
-	return 0;
-}
-__uml_postsetup(make_umid_setup);
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/os-Linux/Makefile b/arch/um/os-Linux/Makefile
index b83ac8e21c3..11e30b13e31 100644
--- a/arch/um/os-Linux/Makefile
+++ b/arch/um/os-Linux/Makefile
@@ -4,11 +4,11 @@
 #
 
 obj-y = aio.o elf_aux.o file.o helper.o main.o mem.o process.o signal.o \
-	start_up.o time.o tt.o tty.o uaccess.o user_syms.o drivers/ \
+	start_up.o time.o tt.o tty.o uaccess.o umid.o user_syms.o drivers/ \
 	sys-$(SUBARCH)/
 
 USER_OBJS := aio.o elf_aux.o file.o helper.o main.o mem.o process.o signal.o \
-	start_up.o time.o tt.o tty.o uaccess.o
+	start_up.o time.o tt.o tty.o uaccess.o umid.o
 
 elf_aux.o: $(ARCH_DIR)/kernel-offsets.h
 CFLAGS_elf_aux.o += -I$(objtree)/arch/um
diff --git a/arch/um/os-Linux/aio.c b/arch/um/os-Linux/aio.c
index ffa759addd3..f897140cc4a 100644
--- a/arch/um/os-Linux/aio.c
+++ b/arch/um/os-Linux/aio.c
@@ -16,12 +16,12 @@
 #include "mode.h"
 
 struct aio_thread_req {
-        enum aio_type type;
-        int io_fd;
-        unsigned long long offset;
-        char *buf;
-        int len;
-        struct aio_context *aio;
+	enum aio_type type;
+	int io_fd;
+	unsigned long long offset;
+	char *buf;
+	int len;
+	struct aio_context *aio;
 };
 
 static int aio_req_fd_r = -1;
@@ -38,18 +38,18 @@ static int aio_req_fd_w = -1;
 
 static long io_setup(int n, aio_context_t *ctxp)
 {
-        return syscall(__NR_io_setup, n, ctxp);
+	return syscall(__NR_io_setup, n, ctxp);
 }
 
 static long io_submit(aio_context_t ctx, long nr, struct iocb **iocbpp)
 {
-        return syscall(__NR_io_submit, ctx, nr, iocbpp);
+	return syscall(__NR_io_submit, ctx, nr, iocbpp);
 }
 
 static long io_getevents(aio_context_t ctx_id, long min_nr, long nr,
-                         struct io_event *events, struct timespec *timeout)
+			 struct io_event *events, struct timespec *timeout)
 {
-        return syscall(__NR_io_getevents, ctx_id, min_nr, nr, events, timeout);
+	return syscall(__NR_io_getevents, ctx_id, min_nr, nr, events, timeout);
 }
 
 #endif
@@ -66,243 +66,245 @@ static long io_getevents(aio_context_t ctx_id, long min_nr, long nr,
  */
 
 static int do_aio(aio_context_t ctx, enum aio_type type, int fd, char *buf,
-                  int len, unsigned long long offset, struct aio_context *aio)
+		  int len, unsigned long long offset, struct aio_context *aio)
 {
-        struct iocb iocb, *iocbp = &iocb;
-        char c;
-        int err;
-
-        iocb = ((struct iocb) { .aio_data 	= (unsigned long) aio,
-                                .aio_reqprio	= 0,
-                                .aio_fildes	= fd,
-                                .aio_buf	= (unsigned long) buf,
-                                .aio_nbytes	= len,
-                                .aio_offset	= offset,
-                                .aio_reserved1	= 0,
-                                .aio_reserved2	= 0,
-                                .aio_reserved3	= 0 });
-
-        switch(type){
-        case AIO_READ:
-                iocb.aio_lio_opcode = IOCB_CMD_PREAD;
-                err = io_submit(ctx, 1, &iocbp);
-                break;
-        case AIO_WRITE:
-                iocb.aio_lio_opcode = IOCB_CMD_PWRITE;
-                err = io_submit(ctx, 1, &iocbp);
-                break;
-        case AIO_MMAP:
-                iocb.aio_lio_opcode = IOCB_CMD_PREAD;
-                iocb.aio_buf = (unsigned long) &c;
-                iocb.aio_nbytes = sizeof(c);
-                err = io_submit(ctx, 1, &iocbp);
-                break;
-        default:
-                printk("Bogus op in do_aio - %d\n", type);
-                err = -EINVAL;
-                break;
-        }
-
-        if(err > 0)
-                err = 0;
+	struct iocb iocb, *iocbp = &iocb;
+	char c;
+	int err;
+
+	iocb = ((struct iocb) { .aio_data 	= (unsigned long) aio,
+				.aio_reqprio	= 0,
+				.aio_fildes	= fd,
+				.aio_buf	= (unsigned long) buf,
+				.aio_nbytes	= len,
+				.aio_offset	= offset,
+				.aio_reserved1	= 0,
+				.aio_reserved2	= 0,
+				.aio_reserved3	= 0 });
+
+	switch(type){
+	case AIO_READ:
+		iocb.aio_lio_opcode = IOCB_CMD_PREAD;
+		err = io_submit(ctx, 1, &iocbp);
+		break;
+	case AIO_WRITE:
+		iocb.aio_lio_opcode = IOCB_CMD_PWRITE;
+		err = io_submit(ctx, 1, &iocbp);
+		break;
+	case AIO_MMAP:
+		iocb.aio_lio_opcode = IOCB_CMD_PREAD;
+		iocb.aio_buf = (unsigned long) &c;
+		iocb.aio_nbytes = sizeof(c);
+		err = io_submit(ctx, 1, &iocbp);
+		break;
+	default:
+		printk("Bogus op in do_aio - %d\n", type);
+		err = -EINVAL;
+		break;
+	}
+
+	if(err > 0)
+		err = 0;
 	else
 		err = -errno;
 
-        return err;
+	return err;
 }
 
 static aio_context_t ctx = 0;
 
 static int aio_thread(void *arg)
 {
-        struct aio_thread_reply reply;
-        struct io_event event;
-        int err, n, reply_fd;
-
-        signal(SIGWINCH, SIG_IGN);
-
-        while(1){
-                n = io_getevents(ctx, 1, 1, &event, NULL);
-                if(n < 0){
-                        if(errno == EINTR)
-                                continue;
-                        printk("aio_thread - io_getevents failed, "
-                               "errno = %d\n", errno);
-                }
-                else {
-                        reply = ((struct aio_thread_reply)
-				 { .data = (void *) (long) event.data,
-				   .err	= event.res });
+	struct aio_thread_reply reply;
+	struct io_event event;
+	int err, n, reply_fd;
+
+	signal(SIGWINCH, SIG_IGN);
+
+	while(1){
+		n = io_getevents(ctx, 1, 1, &event, NULL);
+		if(n < 0){
+			if(errno == EINTR)
+				continue;
+			printk("aio_thread - io_getevents failed, "
+			       "errno = %d\n", errno);
+		}
+		else {
+			reply = ((struct aio_thread_reply)
+				{ .data = (void *) (long) event.data,
+						.err	= event.res });
 			reply_fd = ((struct aio_context *) reply.data)->reply_fd;
 			err = os_write_file(reply_fd, &reply, sizeof(reply));
-                        if(err != sizeof(reply))
+			if(err != sizeof(reply))
 				printk("aio_thread - write failed, fd = %d, "
-                                       "err = %d\n", aio_req_fd_r, -err);
-                }
-        }
-        return 0;
+				       "err = %d\n", aio_req_fd_r, -err);
+		}
+	}
+	return 0;
 }
 
 #endif
 
 static int do_not_aio(struct aio_thread_req *req)
 {
-        char c;
-        int err;
-
-        switch(req->type){
-        case AIO_READ:
-                err = os_seek_file(req->io_fd, req->offset);
-                if(err)
-                        goto out;
-
-                err = os_read_file(req->io_fd, req->buf, req->len);
-                break;
-        case AIO_WRITE:
-                err = os_seek_file(req->io_fd, req->offset);
-                if(err)
-                        goto out;
-
-                err = os_write_file(req->io_fd, req->buf, req->len);
-                break;
-        case AIO_MMAP:
-                err = os_seek_file(req->io_fd, req->offset);
-                if(err)
-                        goto out;
-
-                err = os_read_file(req->io_fd, &c, sizeof(c));
-                break;
-        default:
-                printk("do_not_aio - bad request type : %d\n", req->type);
-                err = -EINVAL;
-                break;
-        }
-
- out:
-        return err;
+	char c;
+	int err;
+
+	switch(req->type){
+	case AIO_READ:
+		err = os_seek_file(req->io_fd, req->offset);
+		if(err)
+			goto out;
+
+		err = os_read_file(req->io_fd, req->buf, req->len);
+		break;
+	case AIO_WRITE:
+		err = os_seek_file(req->io_fd, req->offset);
+		if(err)
+			goto out;
+
+		err = os_write_file(req->io_fd, req->buf, req->len);
+		break;
+	case AIO_MMAP:
+		err = os_seek_file(req->io_fd, req->offset);
+		if(err)
+			goto out;
+
+		err = os_read_file(req->io_fd, &c, sizeof(c));
+		break;
+	default:
+		printk("do_not_aio - bad request type : %d\n", req->type);
+		err = -EINVAL;
+		break;
+	}
+
+out:
+	return err;
 }
 
 static int not_aio_thread(void *arg)
 {
-        struct aio_thread_req req;
-        struct aio_thread_reply reply;
-        int err;
-
-        signal(SIGWINCH, SIG_IGN);
-        while(1){
-                err = os_read_file(aio_req_fd_r, &req, sizeof(req));
-                if(err != sizeof(req)){
-                        if(err < 0)
-                                printk("not_aio_thread - read failed, "
-                                       "fd = %d, err = %d\n", aio_req_fd_r,
-                                       -err);
-                        else {
-                                printk("not_aio_thread - short read, fd = %d, "
-                                       "length = %d\n", aio_req_fd_r, err);
-                        }
-                        continue;
-                }
-                err = do_not_aio(&req);
-                reply = ((struct aio_thread_reply) { .data 	= req.aio,
-                                                     .err	= err });
-                err = os_write_file(req.aio->reply_fd, &reply, sizeof(reply));
-                if(err != sizeof(reply))
-                        printk("not_aio_thread - write failed, fd = %d, "
-                               "err = %d\n", aio_req_fd_r, -err);
-        }
+	struct aio_thread_req req;
+	struct aio_thread_reply reply;
+	int err;
+
+	signal(SIGWINCH, SIG_IGN);
+	while(1){
+		err = os_read_file(aio_req_fd_r, &req, sizeof(req));
+		if(err != sizeof(req)){
+			if(err < 0)
+				printk("not_aio_thread - read failed, "
+				       "fd = %d, err = %d\n", aio_req_fd_r,
+				       -err);
+			else {
+				printk("not_aio_thread - short read, fd = %d, "
+				       "length = %d\n", aio_req_fd_r, err);
+			}
+			continue;
+		}
+		err = do_not_aio(&req);
+		reply = ((struct aio_thread_reply) { .data 	= req.aio,
+					 .err	= err });
+		err = os_write_file(req.aio->reply_fd, &reply, sizeof(reply));
+		if(err != sizeof(reply))
+			printk("not_aio_thread - write failed, fd = %d, "
+			       "err = %d\n", aio_req_fd_r, -err);
+	}
+
+	return 0;
 }
 
 static int aio_pid = -1;
 
 static int init_aio_24(void)
 {
-        unsigned long stack;
-        int fds[2], err;
-
-        err = os_pipe(fds, 1, 1);
-        if(err)
-                goto out;
-
-        aio_req_fd_w = fds[0];
-        aio_req_fd_r = fds[1];
-        err = run_helper_thread(not_aio_thread, NULL,
-                                CLONE_FILES | CLONE_VM | SIGCHLD, &stack, 0);
-        if(err < 0)
-                goto out_close_pipe;
-
-        aio_pid = err;
-        goto out;
-
- out_close_pipe:
-        os_close_file(fds[0]);
-        os_close_file(fds[1]);
-        aio_req_fd_w = -1;
-        aio_req_fd_r = -1;
- out:
+	unsigned long stack;
+	int fds[2], err;
+
+	err = os_pipe(fds, 1, 1);
+	if(err)
+		goto out;
+
+	aio_req_fd_w = fds[0];
+	aio_req_fd_r = fds[1];
+	err = run_helper_thread(not_aio_thread, NULL,
+				CLONE_FILES | CLONE_VM | SIGCHLD, &stack, 0);
+	if(err < 0)
+		goto out_close_pipe;
+
+	aio_pid = err;
+	goto out;
+
+out_close_pipe:
+	os_close_file(fds[0]);
+	os_close_file(fds[1]);
+	aio_req_fd_w = -1;
+	aio_req_fd_r = -1;
+out:
 #ifndef HAVE_AIO_ABI
 	printk("/usr/include/linux/aio_abi.h not present during build\n");
 #endif
 	printk("2.6 host AIO support not used - falling back to I/O "
 	       "thread\n");
-        return 0;
+	return 0;
 }
 
 #ifdef HAVE_AIO_ABI
 #define DEFAULT_24_AIO 0
 static int init_aio_26(void)
 {
-        unsigned long stack;
-        int err;
+	unsigned long stack;
+	int err;
 
-        if(io_setup(256, &ctx)){
+	if(io_setup(256, &ctx)){
 		err = -errno;
-                printk("aio_thread failed to initialize context, err = %d\n",
-                       errno);
-                return err;
-        }
+		printk("aio_thread failed to initialize context, err = %d\n",
+		       errno);
+		return err;
+	}
 
-        err = run_helper_thread(aio_thread, NULL,
-                                CLONE_FILES | CLONE_VM | SIGCHLD, &stack, 0);
-        if(err < 0)
-                return err;
+	err = run_helper_thread(aio_thread, NULL,
+				CLONE_FILES | CLONE_VM | SIGCHLD, &stack, 0);
+	if(err < 0)
+		return err;
 
-        aio_pid = err;
+	aio_pid = err;
 
 	printk("Using 2.6 host AIO\n");
-        return 0;
+	return 0;
 }
 
 static int submit_aio_26(enum aio_type type, int io_fd, char *buf, int len,
 			 unsigned long long offset, struct aio_context *aio)
 {
-        struct aio_thread_reply reply;
-        int err;
-
-        err = do_aio(ctx, type, io_fd, buf, len, offset, aio);
-        if(err){
-                reply = ((struct aio_thread_reply) { .data = aio,
-                                                     .err  = err });
-                err = os_write_file(aio->reply_fd, &reply, sizeof(reply));
-                if(err != sizeof(reply))
-                        printk("submit_aio_26 - write failed, "
-                               "fd = %d, err = %d\n", aio->reply_fd, -err);
-                else err = 0;
-        }
-
-        return err;
+	struct aio_thread_reply reply;
+	int err;
+
+	err = do_aio(ctx, type, io_fd, buf, len, offset, aio);
+	if(err){
+		reply = ((struct aio_thread_reply) { .data = aio,
+					 .err  = err });
+		err = os_write_file(aio->reply_fd, &reply, sizeof(reply));
+		if(err != sizeof(reply))
+			printk("submit_aio_26 - write failed, "
+			       "fd = %d, err = %d\n", aio->reply_fd, -err);
+		else err = 0;
+	}
+
+	return err;
 }
 
 #else
 #define DEFAULT_24_AIO 1
 static int init_aio_26(void)
 {
-        return -ENOSYS;
+	return -ENOSYS;
 }
 
 static int submit_aio_26(enum aio_type type, int io_fd, char *buf, int len,
 			 unsigned long long offset, struct aio_context *aio)
 {
-        return -ENOSYS;
+	return -ENOSYS;
 }
 #endif
 
@@ -310,8 +312,8 @@ static int aio_24 = DEFAULT_24_AIO;
 
 static int __init set_aio_24(char *name, int *add)
 {
-        aio_24 = 1;
-        return 0;
+	aio_24 = 1;
+	return 0;
 }
 
 __uml_setup("aio=2.4", set_aio_24,
@@ -328,28 +330,27 @@ __uml_setup("aio=2.4", set_aio_24,
 
 static int init_aio(void)
 {
-        int err;
-
-        CHOOSE_MODE(({
-                if(!aio_24){
-                        printk("Disabling 2.6 AIO in tt mode\n");
-                        aio_24 = 1;
-                } }), (void) 0);
-
-        if(!aio_24){
-                err = init_aio_26();
-                if(err && (errno == ENOSYS)){
-                        printk("2.6 AIO not supported on the host - "
-                               "reverting to 2.4 AIO\n");
-                        aio_24 = 1;
-                }
-                else return err;
-        }
-
-        if(aio_24)
-                return init_aio_24();
-
-        return 0;
+	int err;
+
+	CHOOSE_MODE(({ if(!aio_24){
+			    printk("Disabling 2.6 AIO in tt mode\n");
+			    aio_24 = 1;
+		    } }), (void) 0);
+
+	if(!aio_24){
+		err = init_aio_26();
+		if(err && (errno == ENOSYS)){
+			printk("2.6 AIO not supported on the host - "
+			       "reverting to 2.4 AIO\n");
+			aio_24 = 1;
+		}
+		else return err;
+	}
+
+	if(aio_24)
+		return init_aio_24();
+
+	return 0;
 }
 
 /* The reason for the __initcall/__uml_exitcall asymmetry is that init_aio
@@ -362,8 +363,8 @@ __initcall(init_aio);
 
 static void exit_aio(void)
 {
-        if(aio_pid != -1)
-                os_kill_process(aio_pid, 1);
+	if(aio_pid != -1)
+		os_kill_process(aio_pid, 1);
 }
 
 __uml_exitcall(exit_aio);
@@ -371,30 +372,30 @@ __uml_exitcall(exit_aio);
 static int submit_aio_24(enum aio_type type, int io_fd, char *buf, int len,
 			 unsigned long long offset, struct aio_context *aio)
 {
-        struct aio_thread_req req = { .type 		= type,
-                                      .io_fd		= io_fd,
-                                      .offset		= offset,
-                                      .buf		= buf,
-                                      .len		= len,
-                                      .aio		= aio,
-        };
-        int err;
-
-        err = os_write_file(aio_req_fd_w, &req, sizeof(req));
-        if(err == sizeof(req))
-                err = 0;
-
-        return err;
+	struct aio_thread_req req = { .type 		= type,
+				      .io_fd		= io_fd,
+				      .offset		= offset,
+				      .buf		= buf,
+				      .len		= len,
+				      .aio		= aio,
+	};
+	int err;
+
+	err = os_write_file(aio_req_fd_w, &req, sizeof(req));
+	if(err == sizeof(req))
+		err = 0;
+
+	return err;
 }
 
 int submit_aio(enum aio_type type, int io_fd, char *buf, int len,
-               unsigned long long offset, int reply_fd,
-               struct aio_context *aio)
+	       unsigned long long offset, int reply_fd,
+	       struct aio_context *aio)
 {
-        aio->reply_fd = reply_fd;
-        if(aio_24)
-                return submit_aio_24(type, io_fd, buf, len, offset, aio);
-        else {
-                return submit_aio_26(type, io_fd, buf, len, offset, aio);
-        }
+	aio->reply_fd = reply_fd;
+	if(aio_24)
+		return submit_aio_24(type, io_fd, buf, len, offset, aio);
+	else {
+		return submit_aio_26(type, io_fd, buf, len, offset, aio);
+	}
 }
diff --git a/arch/um/os-Linux/umid.c b/arch/um/os-Linux/umid.c
new file mode 100644
index 00000000000..ecf107ae5ac
--- /dev/null
+++ b/arch/um/os-Linux/umid.c
@@ -0,0 +1,335 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <signal.h>
+#include <dirent.h>
+#include <sys/fcntl.h>
+#include <sys/stat.h>
+#include <sys/param.h>
+#include "init.h"
+#include "os.h"
+#include "user.h"
+#include "mode.h"
+
+#define UML_DIR "~/.uml/"
+
+#define UMID_LEN 64
+
+/* Changed by set_umid, which is run early in boot */
+char umid[UMID_LEN] = { 0 };
+
+/* Changed by set_uml_dir and make_uml_dir, which are run early in boot */
+static char *uml_dir = UML_DIR;
+
+static int __init make_uml_dir(void)
+{
+	char dir[512] = { '\0' };
+	int len, err;
+
+	if(*uml_dir == '~'){
+		char *home = getenv("HOME");
+
+		err = -ENOENT;
+		if(home == NULL){
+			printk("make_uml_dir : no value in environment for "
+			       "$HOME\n");
+			goto err;
+		}
+		strlcpy(dir, home, sizeof(dir));
+		uml_dir++;
+	}
+	strlcat(dir, uml_dir, sizeof(dir));
+	len = strlen(dir);
+	if (len > 0 && dir[len - 1] != '/')
+		strlcat(dir, "/", sizeof(dir));
+
+	err = -ENOMEM;
+	uml_dir = malloc(strlen(dir) + 1);
+	if (uml_dir == NULL) {
+		printf("make_uml_dir : malloc failed, errno = %d\n", errno);
+		goto err;
+	}
+	strcpy(uml_dir, dir);
+
+	if((mkdir(uml_dir, 0777) < 0) && (errno != EEXIST)){
+	        printf("Failed to mkdir '%s': %s\n", uml_dir, strerror(errno));
+		err = -errno;
+		goto err_free;
+	}
+	return 0;
+
+err_free:
+	free(uml_dir);
+err:
+	uml_dir = NULL;
+	return err;
+}
+
+static int actually_do_remove(char *dir)
+{
+	DIR *directory;
+	struct dirent *ent;
+	int len;
+	char file[256];
+
+	directory = opendir(dir);
+	if(directory == NULL)
+		return -errno;
+
+	while((ent = readdir(directory)) != NULL){
+		if(!strcmp(ent->d_name, ".") || !strcmp(ent->d_name, ".."))
+			continue;
+		len = strlen(dir) + sizeof("/") + strlen(ent->d_name) + 1;
+		if(len > sizeof(file))
+			return -E2BIG;
+
+		sprintf(file, "%s/%s", dir, ent->d_name);
+		if(unlink(file) < 0)
+			return -errno;
+	}
+	if(rmdir(dir) < 0)
+		return -errno;
+
+	return 0;
+}
+
+/* This says that there isn't already a user of the specified directory even if
+ * there are errors during the checking.  This is because if these errors
+ * happen, the directory is unusable by the pre-existing UML, so we might as
+ * well take it over.  This could happen either by
+ * 	the existing UML somehow corrupting its umid directory
+ * 	something other than UML sticking stuff in the directory
+ *	this boot racing with a shutdown of the other UML
+ * In any of these cases, the directory isn't useful for anything else.
+ */
+
+static int not_dead_yet(char *dir)
+{
+	char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")];
+	char pid[sizeof("nnnnn\0")], *end;
+	int dead, fd, p, n, err;
+
+	n = snprintf(file, sizeof(file), "%s/pid", dir);
+	if(n >= sizeof(file)){
+		printk("not_dead_yet - pid filename too long\n");
+		err = -E2BIG;
+		goto out;
+	}
+
+	dead = 0;
+	fd = open(file, O_RDONLY);
+	if(fd < 0){
+		if(fd != -ENOENT){
+			printk("not_dead_yet : couldn't open pid file '%s', "
+			       "err = %d\n", file, -fd);
+		}
+		goto out;
+	}
+
+	err = 0;
+	n = read(fd, pid, sizeof(pid));
+	if(n <= 0){
+		printk("not_dead_yet : couldn't read pid file '%s', "
+		       "err = %d\n", file, -n);
+		goto out_close;
+	}
+
+	p = strtoul(pid, &end, 0);
+	if(end == pid){
+		printk("not_dead_yet : couldn't parse pid file '%s', "
+		       "errno = %d\n", file, errno);
+		goto out_close;
+	}
+
+	if((kill(p, 0) == 0) || (errno != ESRCH))
+		return 1;
+
+	err = actually_do_remove(dir);
+	if(err)
+		printk("not_dead_yet - actually_do_remove failed with "
+		       "err = %d\n", err);
+
+	return err;
+
+ out_close:
+	close(fd);
+ out:
+	return 0;
+}
+
+static void __init create_pid_file(void)
+{
+	char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")];
+	char pid[sizeof("nnnnn\0")];
+	int fd, n;
+
+	if(umid_file_name("pid", file, sizeof(file)))
+		return;
+
+	fd = open(file, O_RDWR | O_CREAT | O_EXCL, 0644);
+	if(fd < 0){
+		printk("Open of machine pid file \"%s\" failed: %s\n",
+		       file, strerror(-fd));
+		return;
+	}
+
+	snprintf(pid, sizeof(pid), "%d\n", getpid());
+	n = write(fd, pid, strlen(pid));
+	if(n != strlen(pid))
+		printk("Write of pid file failed - err = %d\n", -n);
+
+	close(fd);
+}
+
+int __init set_umid(char *name)
+{
+	if(strlen(name) > UMID_LEN - 1)
+		return -E2BIG;
+
+	strlcpy(umid, name, sizeof(umid));
+
+	return 0;
+}
+
+static int umid_setup = 0;
+
+int __init make_umid(void)
+{
+	int fd, err;
+	char tmp[256];
+
+	if(umid_setup)
+		return 0;
+
+	make_uml_dir();
+
+	if(*umid == '\0'){
+		strlcpy(tmp, uml_dir, sizeof(tmp));
+		strlcat(tmp, "XXXXXX", sizeof(tmp));
+		fd = mkstemp(tmp);
+		if(fd < 0){
+			printk("make_umid - mkstemp(%s) failed: %s\n",
+			       tmp, strerror(errno));
+			err = -errno;
+			goto err;
+		}
+
+		close(fd);
+
+		set_umid(&tmp[strlen(uml_dir)]);
+
+		/* There's a nice tiny little race between this unlink and
+		 * the mkdir below.  It'd be nice if there were a mkstemp
+		 * for directories.
+		 */
+		if(unlink(tmp)){
+			err = -errno;
+			goto err;
+		}
+	}
+
+	snprintf(tmp, sizeof(tmp), "%s%s", uml_dir, umid);
+	err = mkdir(tmp, 0777);
+	if(err < 0){
+		err = -errno;
+		if(errno != EEXIST)
+			goto err;
+
+		if(not_dead_yet(tmp) < 0)
+			goto err;
+
+		err = mkdir(tmp, 0777);
+	}
+	if(err < 0){
+		printk("Failed to create '%s' - err = %d\n", umid, err);
+		goto err_rmdir;
+	}
+
+	umid_setup = 1;
+
+	create_pid_file();
+
+	return 0;
+
+ err_rmdir:
+	rmdir(tmp);
+ err:
+	return err;
+}
+
+static int __init make_umid_init(void)
+{
+	make_umid();
+
+	return 0;
+}
+
+__initcall(make_umid_init);
+
+int __init umid_file_name(char *name, char *buf, int len)
+{
+	int n, err;
+
+	err = make_umid();
+	if(err)
+		return err;
+
+	n = snprintf(buf, len, "%s%s/%s", uml_dir, umid, name);
+	if(n >= len){
+		printk("umid_file_name : buffer too short\n");
+		return -E2BIG;
+	}
+
+	return 0;
+}
+
+char *get_umid(void)
+{
+	return umid;
+}
+
+static int __init set_uml_dir(char *name, int *add)
+{
+	if(*name == '\0'){
+		printf("uml_dir can't be an empty string\n");
+		return 0;
+	}
+
+	if(name[strlen(name) - 1] == '/'){
+		uml_dir = name;
+		return 0;
+	}
+
+	uml_dir = malloc(strlen(name) + 2);
+	if(uml_dir == NULL){
+		printf("Failed to malloc uml_dir - error = %d\n", errno);
+
+		/* Return 0 here because do_initcalls doesn't look at
+		 * the return value.
+		 */
+		return 0;
+	}
+	sprintf(uml_dir, "%s/", name);
+
+	return 0;
+}
+
+__uml_setup("uml_dir=", set_uml_dir,
+"uml_dir=<directory>\n"
+"    The location to place the pid and umid files.\n\n"
+);
+
+static void remove_umid_dir(void)
+{
+	char dir[strlen(uml_dir) + UMID_LEN + 1], err;
+
+	sprintf(dir, "%s%s", uml_dir, umid);
+	err = actually_do_remove(dir);
+	if(err)
+		printf("remove_umid_dir - actually_do_remove failed with "
+		       "err = %d\n", err);
+}
+
+__uml_exitcall(remove_umid_dir);