Merge branch 'gfar' of master.kernel.org:/pub/scm/linux/kernel/git/galak/powerpc into upstream

57 files changed, 1055 insertions, 1046 deletions

diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index d32a80e6668..b3a21ba77cd 100644
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -16,6 +16,9 @@ config MMU
 	bool
 	default y
 
+config NO_IOMEM
+	def_bool y
+
 mainmenu "Linux/Usermode Kernel Configuration"
 
 config ISA
diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index 7d4190e5565..7b8baf146ac 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -19,44 +19,11 @@
 #include "line.h"
 #include "os.h"
 
-/* XXX: could well be moved to somewhere else, if needed. */
-static int my_printf(const char * fmt, ...)
-	__attribute__ ((format (printf, 1, 2)));
-
-static int my_printf(const char * fmt, ...)
-{
-	/* Yes, can be called on atomic context.*/
-	char *buf = kmalloc(4096, GFP_ATOMIC);
-	va_list args;
-	int r;
-
-	if (!buf) {
-		/* We print directly fmt.
-		 * Yes, yes, yes, feel free to complain. */
-		r = strlen(fmt);
-	} else {
-		va_start(args, fmt);
-		r = vsprintf(buf, fmt, args);
-		va_end(args);
-		fmt = buf;
-	}
-
-	if (r)
-		r = os_write_file(1, fmt, r);
-	return r;
-
-}
-
 #ifdef CONFIG_NOCONFIG_CHAN
-/* Despite its name, there's no added trailing newline. */
-static int my_puts(const char * buf)
-{
-	return os_write_file(1, buf, strlen(buf));
-}
-
-static void *not_configged_init(char *str, int device, struct chan_opts *opts)
+static void *not_configged_init(char *str, int device,
+				const struct chan_opts *opts)
 {
-	my_puts("Using a channel type which is configured out of "
+	printk("Using a channel type which is configured out of "
 	       "UML\n");
 	return NULL;
 }
@@ -64,34 +31,34 @@ static void *not_configged_init(char *str, int device, struct chan_opts *opts)
 static int not_configged_open(int input, int output, int primary, void *data,
 			      char **dev_out)
 {
-	my_puts("Using a channel type which is configured out of "
+	printk("Using a channel type which is configured out of "
 	       "UML\n");
 	return -ENODEV;
 }
 
 static void not_configged_close(int fd, void *data)
 {
-	my_puts("Using a channel type which is configured out of "
+	printk("Using a channel type which is configured out of "
 	       "UML\n");
 }
 
 static int not_configged_read(int fd, char *c_out, void *data)
 {
-	my_puts("Using a channel type which is configured out of "
+	printk("Using a channel type which is configured out of "
 	       "UML\n");
 	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 "
+	printk("Using a channel type which is configured out of "
 	       "UML\n");
 	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 "
+	printk("Using a channel type which is configured out of "
 	       "UML\n");
 	return -EIO;
 }
@@ -99,14 +66,14 @@ static int not_configged_console_write(int fd, const char *buf, int len)
 static int not_configged_window_size(int fd, void *data, unsigned short *rows,
 				     unsigned short *cols)
 {
-	my_puts("Using a channel type which is configured out of "
+	printk("Using a channel type which is configured out of "
 	       "UML\n");
 	return -ENODEV;
 }
 
 static void not_configged_free(void *data)
 {
-	my_puts("Using a channel type which is configured out of "
+	printk("Using a channel type which is configured out of "
 	       "UML\n");
 }
 
@@ -255,15 +222,28 @@ void enable_chan(struct line *line)
 	}
 }
 
+/* Items are added in IRQ context, when free_irq can't be called, and
+ * removed in process context, when it can.
+ * This handles interrupt sources which disappear, and which need to
+ * be permanently disabled.  This is discovered in IRQ context, but
+ * the freeing of the IRQ must be done later.
+ */
+static DEFINE_SPINLOCK(irqs_to_free_lock);
 static LIST_HEAD(irqs_to_free);
 
 void free_irqs(void)
 {
 	struct chan *chan;
+	LIST_HEAD(list);
+	struct list_head *ele;
 
-	while(!list_empty(&irqs_to_free)){
-		chan = list_entry(irqs_to_free.next, struct chan, free_list);
-		list_del(&chan->free_list);
+	spin_lock_irq(&irqs_to_free_lock);
+	list_splice_init(&irqs_to_free, &list);
+	INIT_LIST_HEAD(&irqs_to_free);
+	spin_unlock_irq(&irqs_to_free_lock);
+
+	list_for_each(ele, &list){
+		chan = list_entry(ele, struct chan, free_list);
 
 		if(chan->input)
 			free_irq(chan->line->driver->read_irq, chan);
@@ -279,7 +259,9 @@ static void close_one_chan(struct chan *chan, int delay_free_irq)
 		return;
 
 	if(delay_free_irq){
+		spin_lock_irq(&irqs_to_free_lock);
 		list_add(&chan->free_list, &irqs_to_free);
+		spin_unlock_irq(&irqs_to_free_lock);
 	}
 	else {
 		if(chan->input)
@@ -372,8 +354,7 @@ int console_write_chan(struct list_head *chans, const char *buf, int len)
 	return ret;
 }
 
-int console_open_chan(struct line *line, struct console *co,
-		      const struct chan_opts *opts)
+int console_open_chan(struct line *line, struct console *co)
 {
 	int err;
 
@@ -381,7 +362,7 @@ int console_open_chan(struct line *line, struct console *co,
 	if(err)
 		return err;
 
-	printk("Console initialized on /dev/%s%d\n",co->name,co->index);
+	printk("Console initialized on /dev/%s%d\n", co->name, co->index);
 	return 0;
 }
 
@@ -534,7 +515,7 @@ static const struct chan_type chan_table[] = {
 };
 
 static struct chan *parse_chan(struct line *line, char *str, int device,
-			       const struct chan_opts *opts)
+			       const struct chan_opts *opts, char **error_out)
 {
 	const struct chan_type *entry;
 	const struct chan_ops *ops;
@@ -553,19 +534,21 @@ static struct chan *parse_chan(struct line *line, char *str, int device,
 		}
 	}
 	if(ops == NULL){
-		my_printf("parse_chan couldn't parse \"%s\"\n",
-		       str);
+		*error_out = "No match for configured backends";
 		return NULL;
 	}
-	if(ops->init == NULL)
-		return NULL;
+
 	data = (*ops->init)(str, device, opts);
-	if(data == NULL)
+	if(data == NULL){
+		*error_out = "Configuration failed";
 		return NULL;
+	}
 
 	chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
-	if(chan == NULL)
+	if(chan == NULL){
+		*error_out = "Memory allocation failed";
 		return NULL;
+	}
 	*chan = ((struct chan) { .list	 	= LIST_HEAD_INIT(chan->list),
 				 .free_list 	=
 				 	LIST_HEAD_INIT(chan->free_list),
@@ -582,7 +565,7 @@ static struct chan *parse_chan(struct line *line, char *str, int device,
 }
 
 int parse_chan_pair(char *str, struct line *line, int device,
-		    const struct chan_opts *opts)
+		    const struct chan_opts *opts, char **error_out)
 {
 	struct list_head *chans = &line->chan_list;
 	struct chan *new, *chan;
@@ -599,14 +582,14 @@ int parse_chan_pair(char *str, struct line *line, int device,
 		in = str;
 		*out = '\0';
 		out++;
-		new = parse_chan(line, in, device, opts);
+		new = parse_chan(line, in, device, opts, error_out);
 		if(new == NULL)
 			return -1;
 
 		new->input = 1;
 		list_add(&new->list, chans);
 
-		new = parse_chan(line, out, device, opts);
+		new = parse_chan(line, out, device, opts, error_out);
 		if(new == NULL)
 			return -1;
 
@@ -614,7 +597,7 @@ int parse_chan_pair(char *str, struct line *line, int device,
 		new->output = 1;
 	}
 	else {
-		new = parse_chan(line, str, device, opts);
+		new = parse_chan(line, str, device, opts, error_out);
 		if(new == NULL)
 			return -1;
 
diff --git a/arch/um/drivers/harddog_kern.c b/arch/um/drivers/harddog_kern.c
index 64ff22aa077..55601687b3b 100644
--- a/arch/um/drivers/harddog_kern.c
+++ b/arch/um/drivers/harddog_kern.c
@@ -9,10 +9,10 @@
  *	modify it under the terms of the GNU General Public License
  *	as published by the Free Software Foundation; either version
  *	2 of the License, or (at your option) any later version.
- *	
- *	Neither Alan Cox nor CymruNet Ltd. admit liability nor provide 
- *	warranty for any of this software. This material is provided 
- *	"AS-IS" and at no charge.	
+ *
+ *	Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
+ *	warranty for any of this software. This material is provided
+ *	"AS-IS" and at no charge.
  *
  *	(c) Copyright 1995    Alan Cox <alan@lxorguk.ukuu.org.uk>
  *
@@ -29,11 +29,11 @@
  *	Made SMP safe for 2.3.x
  *
  *  20011127 Joel Becker (jlbec@evilplan.org>
- *	Added soft_noboot; Allows testing the softdog trigger without 
+ *	Added soft_noboot; Allows testing the softdog trigger without
  *	requiring a recompile.
  *	Added WDIOC_GETTIMEOUT and WDIOC_SETTIMOUT.
  */
- 
+
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
@@ -44,12 +44,13 @@
 #include <linux/reboot.h>
 #include <linux/smp_lock.h>
 #include <linux/init.h>
+#include <linux/spinlock.h>
 #include <asm/uaccess.h>
 #include "mconsole.h"
 
 MODULE_LICENSE("GPL");
 
-/* Locked by the BKL in harddog_open and harddog_release */
+static DEFINE_SPINLOCK(lock);
 static int timer_alive;
 static int harddog_in_fd = -1;
 static int harddog_out_fd = -1;
@@ -57,18 +58,18 @@ static int harddog_out_fd = -1;
 /*
  *	Allow only one person to hold it open
  */
- 
+
 extern int start_watchdog(int *in_fd_ret, int *out_fd_ret, char *sock);
 
 static int harddog_open(struct inode *inode, struct file *file)
 {
-	int err;
+	int err = -EBUSY;
 	char *sock = NULL;
 
-	lock_kernel();
+	spin_lock(&lock);
 	if(timer_alive)
-		return -EBUSY;
-#ifdef CONFIG_HARDDOG_NOWAYOUT	 
+		goto err;
+#ifdef CONFIG_HARDDOG_NOWAYOUT
 	__module_get(THIS_MODULE);
 #endif
 
@@ -76,11 +77,15 @@ static int harddog_open(struct inode *inode, struct file *file)
 	sock = mconsole_notify_socket();
 #endif
 	err = start_watchdog(&harddog_in_fd, &harddog_out_fd, sock);
-	if(err) return(err);
+	if(err)
+		goto err;
 
 	timer_alive = 1;
-	unlock_kernel();
+	spin_unlock(&lock);
 	return nonseekable_open(inode, file);
+err:
+	spin_unlock(&lock);
+	return err;
 }
 
 extern void stop_watchdog(int in_fd, int out_fd);
@@ -90,14 +95,16 @@ static int harddog_release(struct inode *inode, struct file *file)
 	/*
 	 *	Shut off the timer.
 	 */
-	lock_kernel();
+
+	spin_lock(&lock);
 
 	stop_watchdog(harddog_in_fd, harddog_out_fd);
 	harddog_in_fd = -1;
 	harddog_out_fd = -1;
 
 	timer_alive=0;
-	unlock_kernel();
+	spin_unlock(&lock);
+
 	return 0;
 }
 
@@ -110,7 +117,7 @@ static ssize_t harddog_write(struct file *file, const char __user *data, size_t
 	 *	Refresh the timer.
 	 */
 	if(len)
-		return(ping_watchdog(harddog_out_fd));
+		return ping_watchdog(harddog_out_fd);
 	return 0;
 }
 
@@ -134,11 +141,11 @@ static int harddog_ioctl(struct inode *inode, struct file *file,
 		case WDIOC_GETBOOTSTATUS:
 			return put_user(0,(int __user *)argp);
 		case WDIOC_KEEPALIVE:
-			return(ping_watchdog(harddog_out_fd));
+			return ping_watchdog(harddog_out_fd);
 	}
 }
 
-static struct file_operations harddog_fops = {
+static const struct file_operations harddog_fops = {
 	.owner		= THIS_MODULE,
 	.write		= harddog_write,
 	.ioctl		= harddog_ioctl,
@@ -165,7 +172,7 @@ static int __init harddog_init(void)
 
 	printk(banner);
 
-	return(0);
+	return 0;
 }
 
 static void __exit harddog_exit(void)
@@ -175,14 +182,3 @@ static void __exit harddog_exit(void)
 
 module_init(harddog_init);
 module_exit(harddog_exit);
-
-/*
- * 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/harddog_user.c b/arch/um/drivers/harddog_user.c
index def013b5a3c..c495ecf263b 100644
--- a/arch/um/drivers/harddog_user.c
+++ b/arch/um/drivers/harddog_user.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -38,7 +38,7 @@ int start_watchdog(int *in_fd_ret, int *out_fd_ret, char *sock)
 	int in_fds[2], out_fds[2], pid, n, err;
 	char pid_buf[sizeof("nnnnn\0")], c;
 	char *pid_args[] = { "/usr/bin/uml_watchdog", "-pid", pid_buf, NULL };
-	char *mconsole_args[] = { "/usr/bin/uml_watchdog", "-mconsole", NULL, 
+	char *mconsole_args[] = { "/usr/bin/uml_watchdog", "-mconsole", NULL,
 				  NULL };
 	char **args = NULL;
 
@@ -96,7 +96,7 @@ int start_watchdog(int *in_fd_ret, int *out_fd_ret, char *sock)
 	}
 	*in_fd_ret = in_fds[0];
 	*out_fd_ret = out_fds[1];
-	return(0);
+	return 0;
 
  out_close_in:
 	os_close_file(in_fds[0]);
@@ -105,7 +105,7 @@ int start_watchdog(int *in_fd_ret, int *out_fd_ret, char *sock)
 	os_close_file(out_fds[0]);
 	os_close_file(out_fds[1]);
  out:
-	return(err);
+	return err;
 }
 
 void stop_watchdog(int in_fd, int out_fd)
@@ -123,20 +123,9 @@ int ping_watchdog(int fd)
 	if(n != sizeof(c)){
 		printk("ping_watchdog - write failed, err = %d\n", -n);
 		if(n < 0)
-			return(n);
-		return(-EIO);
+			return n;
+		return -EIO;
 	}
 	return 1;
 
 }
-
-/*
- * 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/hostaudio_kern.c b/arch/um/drivers/hostaudio_kern.c
index a0d148ea63d..10e08a8c17c 100644
--- a/arch/um/drivers/hostaudio_kern.c
+++ b/arch/um/drivers/hostaudio_kern.c
@@ -15,19 +15,22 @@
 #include "os.h"
 
 struct hostaudio_state {
-  int fd;
+	int fd;
 };
 
 struct hostmixer_state {
-  int fd;
+	int fd;
 };
 
 #define HOSTAUDIO_DEV_DSP "/dev/sound/dsp"
 #define HOSTAUDIO_DEV_MIXER "/dev/sound/mixer"
 
-/* Only changed from linux_main at boot time */
-char *dsp = HOSTAUDIO_DEV_DSP;
-char *mixer = HOSTAUDIO_DEV_MIXER;
+/* Changed either at boot time or module load time.  At boot, this is
+ * single-threaded; at module load, multiple modules would each have
+ * their own copy of these variables.
+ */
+static char *dsp = HOSTAUDIO_DEV_DSP;
+static char *mixer = HOSTAUDIO_DEV_MIXER;
 
 #define DSP_HELP \
 "    This is used to specify the host dsp device to the hostaudio driver.\n" \
@@ -69,12 +72,12 @@ MODULE_PARM_DESC(mixer, MIXER_HELP);
 static ssize_t hostaudio_read(struct file *file, char __user *buffer,
 			      size_t count, loff_t *ppos)
 {
-        struct hostaudio_state *state = file->private_data;
+	struct hostaudio_state *state = file->private_data;
 	void *kbuf;
 	int err;
 
 #ifdef DEBUG
-        printk("hostaudio: read called, count = %d\n", count);
+	printk("hostaudio: read called, count = %d\n", count);
 #endif
 
 	kbuf = kmalloc(count, GFP_KERNEL);
@@ -88,7 +91,7 @@ static ssize_t hostaudio_read(struct file *file, char __user *buffer,
 	if(copy_to_user(buffer, kbuf, err))
 		err = -EFAULT;
 
- out:
+out:
 	kfree(kbuf);
 	return(err);
 }
@@ -96,12 +99,12 @@ static ssize_t hostaudio_read(struct file *file, char __user *buffer,
 static ssize_t hostaudio_write(struct file *file, const char __user *buffer,
 			       size_t count, loff_t *ppos)
 {
-        struct hostaudio_state *state = file->private_data;
+	struct hostaudio_state *state = file->private_data;
 	void *kbuf;
 	int err;
 
 #ifdef DEBUG
-        printk("hostaudio: write called, count = %d\n", count);
+	printk("hostaudio: write called, count = %d\n", count);
 #endif
 
 	kbuf = kmalloc(count, GFP_KERNEL);
@@ -125,24 +128,24 @@ static ssize_t hostaudio_write(struct file *file, const char __user *buffer,
 static unsigned int hostaudio_poll(struct file *file, 
 				   struct poll_table_struct *wait)
 {
-        unsigned int mask = 0;
+	unsigned int mask = 0;
 
 #ifdef DEBUG
-        printk("hostaudio: poll called (unimplemented)\n");
+	printk("hostaudio: poll called (unimplemented)\n");
 #endif
 
-        return(mask);
+	return(mask);
 }
 
 static int hostaudio_ioctl(struct inode *inode, struct file *file, 
 			   unsigned int cmd, unsigned long arg)
 {
-        struct hostaudio_state *state = file->private_data;
+	struct hostaudio_state *state = file->private_data;
 	unsigned long data = 0;
 	int err;
 
 #ifdef DEBUG
-        printk("hostaudio: ioctl called, cmd = %u\n", cmd);
+	printk("hostaudio: ioctl called, cmd = %u\n", cmd);
 #endif
 	switch(cmd){
 	case SNDCTL_DSP_SPEED:
@@ -179,42 +182,40 @@ static int hostaudio_ioctl(struct inode *inode, struct file *file,
 
 static int hostaudio_open(struct inode *inode, struct file *file)
 {
-        struct hostaudio_state *state;
-        int r = 0, w = 0;
-        int ret;
+	struct hostaudio_state *state;
+	int r = 0, w = 0;
+	int ret;
 
 #ifdef DEBUG
-        printk("hostaudio: open called (host: %s)\n", dsp);
+	printk("hostaudio: open called (host: %s)\n", dsp);
 #endif
 
-        state = kmalloc(sizeof(struct hostaudio_state), GFP_KERNEL);
-        if(state == NULL)
+	state = kmalloc(sizeof(struct hostaudio_state), GFP_KERNEL);
+	if(state == NULL)
 		return(-ENOMEM);
 
-        if(file->f_mode & FMODE_READ) r = 1;
-        if(file->f_mode & FMODE_WRITE) w = 1;
+	if(file->f_mode & FMODE_READ) r = 1;
+	if(file->f_mode & FMODE_WRITE) w = 1;
 
 	ret = os_open_file(dsp, of_set_rw(OPENFLAGS(), r, w), 0);
-        if(ret < 0){
+	if(ret < 0){
 		kfree(state);
 		return(ret);
-        }
-
+	}
 	state->fd = ret;
-        file->private_data = state;
-        return(0);
+	file->private_data = state;
+	return(0);
 }
 
 static int hostaudio_release(struct inode *inode, struct file *file)
 {
-        struct hostaudio_state *state = file->private_data;
+	struct hostaudio_state *state = file->private_data;
 
 #ifdef DEBUG
-        printk("hostaudio: release called\n");
+	printk("hostaudio: release called\n");
 #endif
-
-		os_close_file(state->fd);
-        kfree(state);
+	os_close_file(state->fd);
+	kfree(state);
 
 	return(0);
 }
@@ -224,10 +225,10 @@ static int hostaudio_release(struct inode *inode, struct file *file)
 static int hostmixer_ioctl_mixdev(struct inode *inode, struct file *file, 
 				  unsigned int cmd, unsigned long arg)
 {
-        struct hostmixer_state *state = file->private_data;
+	struct hostmixer_state *state = file->private_data;
 
 #ifdef DEBUG
-        printk("hostmixer: ioctl called\n");
+	printk("hostmixer: ioctl called\n");
 #endif
 
 	return(os_ioctl_generic(state->fd, cmd, arg));
@@ -235,68 +236,67 @@ static int hostmixer_ioctl_mixdev(struct inode *inode, struct file *file,
 
 static int hostmixer_open_mixdev(struct inode *inode, struct file *file)
 {
-        struct hostmixer_state *state;
-        int r = 0, w = 0;
-        int ret;
+	struct hostmixer_state *state;
+	int r = 0, w = 0;
+	int ret;
 
 #ifdef DEBUG
-        printk("hostmixer: open called (host: %s)\n", mixer);
+	printk("hostmixer: open called (host: %s)\n", mixer);
 #endif
 
-        state = kmalloc(sizeof(struct hostmixer_state), GFP_KERNEL);
-        if(state == NULL) return(-ENOMEM);
+	state = kmalloc(sizeof(struct hostmixer_state), GFP_KERNEL);
+	if(state == NULL) return(-ENOMEM);
 
-        if(file->f_mode & FMODE_READ) r = 1;
-        if(file->f_mode & FMODE_WRITE) w = 1;
+	if(file->f_mode & FMODE_READ) r = 1;
+	if(file->f_mode & FMODE_WRITE) w = 1;
 
 	ret = os_open_file(mixer, of_set_rw(OPENFLAGS(), r, w), 0);
         
-        if(ret < 0){
+	if(ret < 0){
 		printk("hostaudio_open_mixdev failed to open '%s', err = %d\n",
 		       dsp, -ret);
 		kfree(state);
 		return(ret);
-        }
+	}
 
-        file->private_data = state;
-        return(0);
+	file->private_data = state;
+	return(0);
 }
 
 static int hostmixer_release(struct inode *inode, struct file *file)
 {
-        struct hostmixer_state *state = file->private_data;
+	struct hostmixer_state *state = file->private_data;
 
 #ifdef DEBUG
-        printk("hostmixer: release called\n");
+	printk("hostmixer: release called\n");
 #endif
 
-		os_close_file(state->fd);
-        kfree(state);
+	os_close_file(state->fd);
+	kfree(state);
 
 	return(0);
 }
 
-
 /* kernel module operations */
 
 static const struct file_operations hostaudio_fops = {
-        .owner          = THIS_MODULE,
-        .llseek         = no_llseek,
-        .read           = hostaudio_read,
-        .write          = hostaudio_write,
-        .poll           = hostaudio_poll,
-        .ioctl          = hostaudio_ioctl,
-        .mmap           = NULL,
-        .open           = hostaudio_open,
-        .release        = hostaudio_release,
+	.owner          = THIS_MODULE,
+	.llseek         = no_llseek,
+	.read           = hostaudio_read,
+	.write          = hostaudio_write,
+	.poll           = hostaudio_poll,
+	.ioctl          = hostaudio_ioctl,
+	.mmap           = NULL,
+	.open           = hostaudio_open,
+	.release        = hostaudio_release,
 };
 
 static const struct file_operations hostmixer_fops = {
-        .owner          = THIS_MODULE,
-        .llseek         = no_llseek,
-        .ioctl          = hostmixer_ioctl_mixdev,
-        .open           = hostmixer_open_mixdev,
-        .release        = hostmixer_release,
+	.owner          = THIS_MODULE,
+	.llseek         = no_llseek,
+	.ioctl          = hostmixer_ioctl_mixdev,
+	.open           = hostmixer_open_mixdev,
+	.release        = hostmixer_release,
 };
 
 struct {
@@ -310,42 +310,31 @@ MODULE_LICENSE("GPL");
 
 static int __init hostaudio_init_module(void)
 {
-        printk(KERN_INFO "UML Audio Relay (host dsp = %s, host mixer = %s)\n",
+	printk(KERN_INFO "UML Audio Relay (host dsp = %s, host mixer = %s)\n",
 	       dsp, mixer);
 
 	module_data.dev_audio = register_sound_dsp(&hostaudio_fops, -1);
-        if(module_data.dev_audio < 0){
-                printk(KERN_ERR "hostaudio: couldn't register DSP device!\n");
-                return -ENODEV;
-        }
+	if(module_data.dev_audio < 0){
+		printk(KERN_ERR "hostaudio: couldn't register DSP device!\n");
+		return -ENODEV;
+	}
 
 	module_data.dev_mixer = register_sound_mixer(&hostmixer_fops, -1);
-        if(module_data.dev_mixer < 0){
-                printk(KERN_ERR "hostmixer: couldn't register mixer "
+	if(module_data.dev_mixer < 0){
+		printk(KERN_ERR "hostmixer: couldn't register mixer "
 		       "device!\n");
-                unregister_sound_dsp(module_data.dev_audio);
-                return -ENODEV;
-        }
+		unregister_sound_dsp(module_data.dev_audio);
+		return -ENODEV;
+	}
 
-        return 0;
+	return 0;
 }
 
 static void __exit hostaudio_cleanup_module (void)
 {
-       unregister_sound_mixer(module_data.dev_mixer);
-       unregister_sound_dsp(module_data.dev_audio);
+	unregister_sound_mixer(module_data.dev_mixer);
+	unregister_sound_dsp(module_data.dev_audio);
 }
 
 module_init(hostaudio_init_module);
 module_exit(hostaudio_cleanup_module);
-
-/*
- * 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 83301e1ef67..01d4ab6b0ef 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -191,7 +191,6 @@ void line_flush_buffer(struct tty_struct *tty)
 	/*XXX: copied from line_write, verify if it is correct!*/
 	if(tty->stopped)
 		return;
-		//return 0;
 
 	spin_lock_irqsave(&line->lock, flags);
 	err = flush_buffer(line);
@@ -421,42 +420,55 @@ int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
 	return err;
 }
 
+/* Normally, a driver like this can rely mostly on the tty layer
+ * locking, particularly when it comes to the driver structure.
+ * However, in this case, mconsole requests can come in "from the
+ * side", and race with opens and closes.
+ *
+ * mconsole config requests will want to be sure the device isn't in
+ * use, and get_config, open, and close will want a stable
+ * configuration.  The checking and modification of the configuration
+ * is done under a spinlock.  Checking whether the device is in use is
+ * line->tty->count > 1, also under the spinlock.
+ *
+ * tty->count serves to decide whether the device should be enabled or
+ * disabled on the host.  If it's equal to 1, then we are doing the
+ * first open or last close.  Otherwise, open and close just return.
+ */
+
 int line_open(struct line *lines, struct tty_struct *tty)
 {
-	struct line *line;
+	struct line *line = &lines[tty->index];
 	int err = -ENODEV;
 
-	line = &lines[tty->index];
-	tty->driver_data = line;
+	spin_lock(&line->count_lock);
+	if(!line->valid)
+		goto out_unlock;
 
-	/* 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);
+	err = 0;
+	if(tty->count > 1)
+		goto out_unlock;
+
+	spin_unlock(&line->count_lock);
 
 	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_DELAYED_WORK(&line->task, line_timer_cb);
+	enable_chan(line);
+	INIT_DELAYED_WORK(&line->task, line_timer_cb);
 
-		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);
+	if(!line->sigio){
+		chan_enable_winch(&line->chan_list, tty);
+		line->sigio = 1;
 	}
 
-	err = 0;
-out:
-	spin_unlock(&line->lock);
+	chan_window_size(&line->chan_list, &tty->winsize.ws_row,
+			 &tty->winsize.ws_col);
+
+	return err;
+
+out_unlock:
+	spin_unlock(&line->count_lock);
 	return err;
 }
 
@@ -466,25 +478,36 @@ void line_close(struct tty_struct *tty, struct file * filp)
 {
 	struct line *line = tty->driver_data;
 
-	/* XXX: I assume this should be called in process context, not with
-         *  interrupts disabled!
-         */
-	spin_lock_irq(&line->lock);
+	/* If line_open fails (and tty->driver_data is never set),
+	 * tty_open will call line_close.  So just return in this case.
+	 */
+	if(line == NULL)
+		return;
 
 	/* We ignore the error anyway! */
 	flush_buffer(line);
 
-	if(tty->count == 1){
-		line->tty = NULL;
-		tty->driver_data = NULL;
+	spin_lock(&line->count_lock);
+	if(!line->valid)
+		goto out_unlock;
 
-		if(line->sigio){
-			unregister_winch(tty);
-			line->sigio = 0;
-		}
+	if(tty->count > 1)
+		goto out_unlock;
+
+	spin_unlock(&line->count_lock);
+
+	line->tty = NULL;
+	tty->driver_data = NULL;
+
+	if(line->sigio){
+		unregister_winch(tty);
+		line->sigio = 0;
         }
 
-	spin_unlock_irq(&line->lock);
+	return;
+
+out_unlock:
+	spin_unlock(&line->count_lock);
 }
 
 void close_lines(struct line *lines, int nlines)
@@ -495,14 +518,44 @@ void close_lines(struct line *lines, int nlines)
 		close_chan(&lines[i].chan_list, 0);
 }
 
+static int setup_one_line(struct line *lines, int n, char *init, int init_prio,
+			  char **error_out)
+{
+	struct line *line = &lines[n];
+	int err = -EINVAL;
+
+	spin_lock(&line->count_lock);
+
+	if(line->tty != NULL){
+		*error_out = "Device is already open";
+		goto out;
+	}
+
+	if (line->init_pri <= init_prio){
+		line->init_pri = init_prio;
+		if (!strcmp(init, "none"))
+			line->valid = 0;
+		else {
+			line->init_str = init;
+			line->valid = 1;
+		}
+	}
+	err = 0;
+out:
+	spin_unlock(&line->count_lock);
+	return err;
+}
+
 /* Common setup code for both startup command line and mconsole initialization.
  * @lines contains the array (of size @num) to modify;
  * @init is the setup string;
+ * @error_out is an error string in the case of failure;
  */
 
-int line_setup(struct line *lines, unsigned int num, char *init)
+int line_setup(struct line *lines, unsigned int num, char *init,
+	       char **error_out)
 {
-	int i, n;
+	int i, n, err;
 	char *end;
 
 	if(*init == '=') {
@@ -513,73 +566,56 @@ int line_setup(struct line *lines, unsigned int num, char *init)
 	else {
 		n = simple_strtoul(init, &end, 0);
 		if(*end != '='){
-			printk(KERN_ERR "line_setup failed to parse \"%s\"\n",
-			       init);
-			return 0;
+			*error_out = "Couldn't parse device number";
+			return -EINVAL;
 		}
 		init = end;
 	}
 	init++;
 
 	if (n >= (signed int) num) {
-		printk("line_setup - %d out of range ((0 ... %d) allowed)\n",
-		       n, num - 1);
-		return 0;
+		*error_out = "Device number out of range";
+		return -EINVAL;
 	}
 	else if (n >= 0){
-		if (lines[n].tty != NULL) {
-			printk("line_setup - device %d is open\n", n);
-			return 0;
-		}
-		if (lines[n].init_pri <= INIT_ONE){
-			lines[n].init_pri = INIT_ONE;
-			if (!strcmp(init, "none"))
-				lines[n].valid = 0;
-			else {
-				lines[n].init_str = init;
-				lines[n].valid = 1;
-			}
-		}
+		err = setup_one_line(lines, n, init, INIT_ONE, error_out);
+		if(err)
+			return err;
 	}
 	else {
 		for(i = 0; i < num; i++){
-			if(lines[i].init_pri <= INIT_ALL){
-				lines[i].init_pri = INIT_ALL;
-				if(!strcmp(init, "none")) lines[i].valid = 0;
-				else {
-					lines[i].init_str = init;
-					lines[i].valid = 1;
-				}
-			}
+			err = setup_one_line(lines, i, init, INIT_ALL,
+					     error_out);
+			if(err)
+				return err;
 		}
 	}
 	return n == -1 ? num : n;
 }
 
 int line_config(struct line *lines, unsigned int num, char *str,
-		const struct chan_opts *opts)
+		const struct chan_opts *opts, char **error_out)
 {
 	struct line *line;
 	char *new;
 	int n;
 
 	if(*str == '='){
-		printk("line_config - can't configure all devices from "
-		       "mconsole\n");
-		return 1;
+		*error_out = "Can't configure all devices from mconsole";
+		return -EINVAL;
 	}
 
 	new = kstrdup(str, GFP_KERNEL);
 	if(new == NULL){
-		printk("line_config - kstrdup failed\n");
-		return 1;
+		*error_out = "Failed to allocate memory";
+		return -ENOMEM;
 	}
-	n = line_setup(lines, num, new);
+	n = line_setup(lines, num, new, error_out);
 	if(n < 0)
-		return 1;
+		return n;
 
 	line = &lines[n];
-	return parse_chan_pair(line->init_str, line, n, opts);
+	return parse_chan_pair(line->init_str, line, n, opts, error_out);
 }
 
 int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
@@ -602,13 +638,13 @@ int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
 
 	line = &lines[dev];
 
-	spin_lock(&line->lock);
+	spin_lock(&line->count_lock);
 	if(!line->valid)
 		CONFIG_CHUNK(str, size, n, "none", 1);
 	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);
+	spin_unlock(&line->count_lock);
 
 	return n;
 }
@@ -628,22 +664,21 @@ int line_id(char **str, int *start_out, int *end_out)
         return n;
 }
 
-int line_remove(struct line *lines, unsigned int num, int n)
+int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
 {
 	int err;
 	char config[sizeof("conxxxx=none\0")];
 
 	sprintf(config, "%d=none", n);
-	err = line_setup(lines, num, config);
+	err = line_setup(lines, num, config, error_out);
 	if(err >= 0)
 		err = 0;
 	return err;
 }
 
-struct tty_driver *line_register_devfs(struct lines *set,
-				       struct line_driver *line_driver,
-				       const struct tty_operations *ops,
-				       struct line *lines, int nlines)
+struct tty_driver *register_lines(struct line_driver *line_driver,
+				  const struct tty_operations *ops,
+				  struct line *lines, int nlines)
 {
 	int i;
 	struct tty_driver *driver = alloc_tty_driver(nlines);
@@ -683,6 +718,7 @@ static LIST_HEAD(winch_handlers);
 void lines_init(struct line *lines, int nlines, struct chan_opts *opts)
 {
 	struct line *line;
+	char *error;
 	int i;
 
 	for(i = 0; i < nlines; i++){
@@ -696,8 +732,9 @@ void lines_init(struct line *lines, int nlines, struct chan_opts *opts)
 		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);
+		if(parse_chan_pair(line->init_str, line, i, opts, &error)){
+			printk("parse_chan_pair failed for device %d : %s\n",
+			       i, error);
 			line->valid = 0;
 		}
 	}
@@ -737,7 +774,7 @@ static irqreturn_t winch_interrupt(int irq, void *data)
 		line = tty->driver_data;
 		chan_window_size(&line->chan_list, &tty->winsize.ws_row,
 				 &tty->winsize.ws_col);
-		kill_pg(tty->pgrp, SIGWINCH, 1);
+		kill_pgrp(tty->pgrp, SIGWINCH, 1);
 	}
  out:
 	if(winch->fd != -1)
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 96f0189327a..178b2eff4a8 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -33,7 +33,6 @@
 #include "irq_user.h"
 #include "init.h"
 #include "os.h"
-#include "umid.h"
 #include "irq_kern.h"
 #include "choose-mode.h"
 
@@ -337,13 +336,15 @@ void mconsole_stop(struct mc_request *req)
 	mconsole_reply(req, "", 0, 0);
 }
 
-/* This list is populated by __initcall routines. */
-
+static DEFINE_SPINLOCK(mc_devices_lock);
 static LIST_HEAD(mconsole_devices);
 
 void mconsole_register_dev(struct mc_device *new)
 {
+	spin_lock(&mc_devices_lock);
+	BUG_ON(!list_empty(&new->list));
 	list_add(&new->list, &mconsole_devices);
+	spin_unlock(&mc_devices_lock);
 }
 
 static struct mc_device *mconsole_find_dev(char *name)
@@ -367,18 +368,21 @@ struct unplugged_pages {
 	void *pages[UNPLUGGED_PER_PAGE];
 };
 
+static DECLARE_MUTEX(plug_mem_mutex);
 static unsigned long long unplugged_pages_count = 0;
-static struct list_head unplugged_pages = LIST_HEAD_INIT(unplugged_pages);
+static LIST_HEAD(unplugged_pages);
 static int unplug_index = UNPLUGGED_PER_PAGE;
 
-static int mem_config(char *str)
+static int mem_config(char *str, char **error_out)
 {
 	unsigned long long diff;
 	int err = -EINVAL, i, add;
 	char *ret;
 
-	if(str[0] != '=')
+	if(str[0] != '='){
+		*error_out = "Expected '=' after 'mem'";
 		goto out;
+	}
 
 	str++;
 	if(str[0] == '-')
@@ -386,15 +390,21 @@ static int mem_config(char *str)
 	else if(str[0] == '+'){
 		add = 1;
 	}
-	else goto out;
+	else {
+		*error_out = "Expected increment to start with '-' or '+'";
+		goto out;
+	}
 
 	str++;
 	diff = memparse(str, &ret);
-	if(*ret != '\0')
+	if(*ret != '\0'){
+		*error_out = "Failed to parse memory increment";
 		goto out;
+	}
 
 	diff /= PAGE_SIZE;
 
+	down(&plug_mem_mutex);
 	for(i = 0; i < diff; i++){
 		struct unplugged_pages *unplugged;
 		void *addr;
@@ -435,11 +445,14 @@ static int mem_config(char *str)
 				unplugged = list_entry(entry,
 						       struct unplugged_pages,
 						       list);
-				unplugged->pages[unplug_index++] = addr;
 				err = os_drop_memory(addr, PAGE_SIZE);
-				if(err)
+				if(err){
 					printk("Failed to release memory - "
 					       "errno = %d\n", err);
+					*error_out = "Failed to release memory";
+					goto out_unlock;
+				}
+				unplugged->pages[unplug_index++] = addr;
 			}
 
 			unplugged_pages_count++;
@@ -447,6 +460,8 @@ static int mem_config(char *str)
 	}
 
 	err = 0;
+out_unlock:
+	up(&plug_mem_mutex);
 out:
 	return err;
 }
@@ -470,12 +485,14 @@ static int mem_id(char **str, int *start_out, int *end_out)
 	return 0;
 }
 
-static int mem_remove(int n)
+static int mem_remove(int n, char **error_out)
 {
+	*error_out = "Memory doesn't support the remove operation";
 	return -EBUSY;
 }
 
 static struct mc_device mem_mc = {
+	.list		= LIST_HEAD_INIT(mem_mc.list),
 	.name		= "mem",
 	.config		= mem_config,
 	.get_config	= mem_get_config,
@@ -542,7 +559,7 @@ static void mconsole_get_config(int (*get_config)(char *, char *, int,
 void mconsole_config(struct mc_request *req)
 {
 	struct mc_device *dev;
-	char *ptr = req->request.data, *name;
+	char *ptr = req->request.data, *name, *error_string = "";
 	int err;
 
 	ptr += strlen("config");
@@ -559,8 +576,8 @@ void mconsole_config(struct mc_request *req)
 		ptr++;
 
 	if(*ptr == '='){
-		err = (*dev->config)(name);
-		mconsole_reply(req, "", err, 0);
+		err = (*dev->config)(name, &error_string);
+		mconsole_reply(req, error_string, err, 0);
 	}
 	else mconsole_get_config(dev->get_config, req, name);
 }
@@ -595,13 +612,16 @@ void mconsole_remove(struct mc_request *req)
 		goto out;
 	}
 
-	err = (*dev->remove)(n);
+	err_msg = NULL;
+	err = (*dev->remove)(n, &err_msg);
 	switch(err){
 	case -ENODEV:
-		err_msg = "Device doesn't exist";
+		if(err_msg == NULL)
+			err_msg = "Device doesn't exist";
 		break;
 	case -EBUSY:
-		err_msg = "Device is currently open";
+		if(err_msg == NULL)
+			err_msg = "Device is currently open";
 		break;
 	default:
 		break;
@@ -615,7 +635,7 @@ struct mconsole_output {
 	struct mc_request *req;
 };
 
-static DEFINE_SPINLOCK(console_lock);
+static DEFINE_SPINLOCK(client_lock);
 static LIST_HEAD(clients);
 static char console_buf[MCONSOLE_MAX_DATA];
 static int console_index = 0;
@@ -670,16 +690,18 @@ static void with_console(struct mc_request *req, void (*proc)(void *),
 	unsigned long flags;
 
 	entry.req = req;
+	spin_lock_irqsave(&client_lock, flags);
 	list_add(&entry.list, &clients);
-	spin_lock_irqsave(&console_lock, flags);
+	spin_unlock_irqrestore(&client_lock, flags);
 
 	(*proc)(arg);
 
 	mconsole_reply_len(req, console_buf, console_index, 0, 0);
 	console_index = 0;
 
-	spin_unlock_irqrestore(&console_lock, flags);
+	spin_lock_irqsave(&client_lock, flags);
 	list_del(&entry.list);
+	spin_unlock_irqrestore(&client_lock, flags);
 }
 
 #ifdef CONFIG_MAGIC_SYSRQ
diff --git a/arch/um/drivers/mconsole_user.c b/arch/um/drivers/mconsole_user.c
index 75aef6f7ef6..f02634fbf32 100644
--- a/arch/um/drivers/mconsole_user.c
+++ b/arch/um/drivers/mconsole_user.c
@@ -16,7 +16,7 @@
 #include "user.h"
 #include "sysdep/ptrace.h"
 #include "mconsole.h"
-#include "umid.h"
+#include "os.h"
 #include "user_util.h"
 
 static struct mconsole_command commands[] = {
diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
index afe3d427ddf..04e31f86c10 100644
--- a/arch/um/drivers/net_kern.c
+++ b/arch/um/drivers/net_kern.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and 
+ * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
  * James Leu (jleu@mindspring.net).
  * Copyright (C) 2001 by various other people who didn't put their name here.
  * Licensed under the GPL.
@@ -91,8 +91,8 @@ irqreturn_t uml_net_interrupt(int irq, void *dev_id)
 	spin_lock(&lp->lock);
 	while((err = uml_net_rx(dev)) > 0) ;
 	if(err < 0) {
-		printk(KERN_ERR 
-		       "Device '%s' read returned %d, shutting it down\n", 
+		printk(KERN_ERR
+		       "Device '%s' read returned %d, shutting it down\n",
 		       dev->name, err);
 		/* dev_close can't be called in interrupt context, and takes
 		 * again lp->lock.
@@ -108,7 +108,7 @@ irqreturn_t uml_net_interrupt(int irq, void *dev_id)
 
 out:
 	spin_unlock(&lp->lock);
-	return(IRQ_HANDLED);
+	return IRQ_HANDLED;
 }
 
 static int uml_net_open(struct net_device *dev)
@@ -159,7 +159,7 @@ out:
 static int uml_net_close(struct net_device *dev)
 {
 	struct uml_net_private *lp = dev->priv;
-	
+
 	netif_stop_queue(dev);
 
 	free_irq(dev->irq, dev);
@@ -194,7 +194,7 @@ static int uml_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
 		/* this is normally done in the interrupt when tx finishes */
 		netif_wake_queue(dev);
-	} 
+	}
 	else if(len == 0){
 		netif_start_queue(dev);
 		lp->stats.tx_dropped++;
@@ -239,7 +239,7 @@ static int uml_net_set_mac(struct net_device *dev, void *addr)
 	set_ether_mac(dev, hwaddr->sa_data);
 	spin_unlock_irq(&lp->lock);
 
-	return(0);
+	return 0;
 }
 
 static int uml_net_change_mtu(struct net_device *dev, int new_mtu)
@@ -333,7 +333,7 @@ static int eth_configure(int n, void *init, char *mac,
 	struct uml_net_private *lp;
 	int save, err, size;
 
-	size = transport->private_size + sizeof(struct uml_net_private) + 
+	size = transport->private_size + sizeof(struct uml_net_private) +
 		sizeof(((struct uml_net_private *) 0)->user);
 
 	device = kzalloc(sizeof(*device), GFP_KERNEL);
@@ -438,7 +438,7 @@ static int eth_configure(int n, void *init, char *mac,
 	lp->tl.function = uml_net_user_timer_expire;
 	memcpy(lp->mac, device->mac, sizeof(lp->mac));
 
-	if (transport->user->init) 
+	if (transport->user->init)
 		(*transport->user->init)(&lp->user, dev);
 
 	set_ether_mac(dev, device->mac);
@@ -460,38 +460,36 @@ static struct uml_net *find_device(int n)
 	device = NULL;
  out:
 	spin_unlock(&devices_lock);
-	return(device);
+	return device;
 }
 
-static int eth_parse(char *str, int *index_out, char **str_out)
+static int eth_parse(char *str, int *index_out, char **str_out,
+		     char **error_out)
 {
 	char *end;
-	int n;
+	int n, err = -EINVAL;;
 
 	n = simple_strtoul(str, &end, 0);
 	if(end == str){
-		printk(KERN_ERR "eth_setup: Failed to parse '%s'\n", str);
-		return(1);
-	}
-	if(n < 0){
-		printk(KERN_ERR "eth_setup: device %d is negative\n", n);
-		return(1);
+		*error_out = "Bad device number";
+		return err;
 	}
+
 	str = end;
 	if(*str != '='){
-		printk(KERN_ERR 
-		       "eth_setup: expected '=' after device number\n");
-		return(1);
+		*error_out = "Expected '=' after device number";
+		return err;
 	}
+
 	str++;
 	if(find_device(n)){
-		printk(KERN_ERR "eth_setup: Device %d already configured\n",
-		       n);
-		return(1);
+		*error_out = "Device already configured";
+		return err;
 	}
-	if(index_out) *index_out = n;
+
+	*index_out = n;
 	*str_out = str;
-	return(0);
+	return 0;
 }
 
 struct eth_init {
@@ -500,13 +498,11 @@ struct eth_init {
 	int index;
 };
 
-/* Filled in at boot time.  Will need locking if the transports become
- * modular.
- */
-struct list_head transports = LIST_HEAD_INIT(transports);
+static DEFINE_SPINLOCK(transports_lock);
+static LIST_HEAD(transports);
 
 /* Filled in during early boot */
-struct list_head eth_cmd_line = LIST_HEAD_INIT(eth_cmd_line);
+static LIST_HEAD(eth_cmd_line);
 
 static int check_transport(struct transport *transport, char *eth, int n,
 			   void **init_out, char **mac_out)
@@ -515,23 +511,23 @@ static int check_transport(struct transport *transport, char *eth, int n,
 
 	len = strlen(transport->name);
 	if(strncmp(eth, transport->name, len))
-		return(0);
+		return 0;
 
 	eth += len;
 	if(*eth == ',')
 		eth++;
 	else if(*eth != '\0')
-		return(0);
+		return 0;
 
 	*init_out = kmalloc(transport->setup_size, GFP_KERNEL);
 	if(*init_out == NULL)
-		return(1);
+		return 1;
 
 	if(!transport->setup(eth, mac_out, *init_out)){
 		kfree(*init_out);
 		*init_out = NULL;
 	}
-	return(1);
+	return 1;
 }
 
 void register_transport(struct transport *new)
@@ -542,7 +538,10 @@ void register_transport(struct transport *new)
 	char *mac = NULL;
 	int match;
 
+	spin_lock(&transports_lock);
+	BUG_ON(!list_empty(&new->list));
 	list_add(&new->list, &transports);
+	spin_unlock(&transports_lock);
 
 	list_for_each_safe(ele, next, &eth_cmd_line){
 		eth = list_entry(ele, struct eth_init, list);
@@ -564,7 +563,9 @@ static int eth_setup_common(char *str, int index)
 	struct transport *transport;
 	void *init;
 	char *mac = NULL;
+	int found = 0;
 
+	spin_lock(&transports_lock);
 	list_for_each(ele, &transports){
 		transport = list_entry(ele, struct transport, list);
 	        if(!check_transport(transport, str, index, &init, &mac))
@@ -573,19 +574,26 @@ static int eth_setup_common(char *str, int index)
 			eth_configure(index, init, mac, transport);
 			kfree(init);
 		}
-		return(1);
+		found = 1;
+		break;
 	}
-	return(0);
+
+	spin_unlock(&transports_lock);
+	return found;
 }
 
 static int eth_setup(char *str)
 {
 	struct eth_init *new;
+	char *error;
 	int n, err;
 
-	err = eth_parse(str, &n, &str);
-	if(err)
+	err = eth_parse(str, &n, &str, &error);
+	if(err){
+		printk(KERN_ERR "eth_setup - Couldn't parse '%s' : %s\n",
+		       str, error);
 		return 1;
+	}
 
 	new = alloc_bootmem(sizeof(*new));
 	if (new == NULL){
@@ -607,38 +615,24 @@ __uml_help(eth_setup,
 "    Configure a network device.\n\n"
 );
 
-#if 0
-static int eth_init(void)
-{
-	struct list_head *ele, *next;
-	struct eth_init *eth;
-
-	list_for_each_safe(ele, next, &eth_cmd_line){
-		eth = list_entry(ele, struct eth_init, list);
-
-		if(eth_setup_common(eth->init, eth->index))
-			list_del(&eth->list);
-	}
-	
-	return(1);
-}
-__initcall(eth_init);
-#endif
-
-static int net_config(char *str)
+static int net_config(char *str, char **error_out)
 {
 	int n, err;
 
-	err = eth_parse(str, &n, &str);
-	if(err) return(err);
+	err = eth_parse(str, &n, &str, error_out);
+	if(err)
+		return err;
 
+	/* This string is broken up and the pieces used by the underlying
+	 * driver.  So, it is freed only if eth_setup_common fails.
+	 */
 	str = kstrdup(str, GFP_KERNEL);
 	if(str == NULL){
-		printk(KERN_ERR "net_config failed to strdup string\n");
-		return(-1);
+	        *error_out = "net_config failed to strdup string";
+		return -ENOMEM;
 	}
 	err = !eth_setup_common(str, n);
-	if(err) 
+	if(err)
 		kfree(str);
 	return(err);
 }
@@ -658,7 +652,7 @@ static int net_id(char **str, int *start_out, int *end_out)
         return n;
 }
 
-static int net_remove(int n)
+static int net_remove(int n, char **error_out)
 {
 	struct uml_net *device;
 	struct net_device *dev;
@@ -671,7 +665,7 @@ static int net_remove(int n)
 	dev = device->dev;
 	lp = dev->priv;
 	if(lp->fd > 0)
-                return -EBUSY;
+		return -EBUSY;
 	if(lp->remove != NULL) (*lp->remove)(&lp->user);
 	unregister_netdev(dev);
 	platform_device_unregister(&device->pdev);
@@ -683,10 +677,11 @@ static int net_remove(int n)
 }
 
 static struct mc_device net_mc = {
+	.list		= LIST_HEAD_INIT(net_mc.list),
 	.name		= "eth",
 	.config		= net_config,
 	.get_config	= NULL,
-        .id		= net_id,
+	.id		= net_id,
 	.remove		= net_remove,
 };
 
@@ -699,7 +694,8 @@ static int uml_inetaddr_event(struct notifier_block *this, unsigned long event,
 	void (*proc)(unsigned char *, unsigned char *, void *);
 	unsigned char addr_buf[4], netmask_buf[4];
 
-	if(dev->open != uml_net_open) return(NOTIFY_DONE);
+	if(dev->open != uml_net_open)
+		return NOTIFY_DONE;
 
 	lp = dev->priv;
 
@@ -717,9 +713,10 @@ static int uml_inetaddr_event(struct notifier_block *this, unsigned long event,
 		memcpy(netmask_buf, &ifa->ifa_mask, sizeof(netmask_buf));
 		(*proc)(addr_buf, netmask_buf, &lp->user);
 	}
-	return(NOTIFY_DONE);
+	return NOTIFY_DONE;
 }
 
+/* uml_net_init shouldn't be called twice on two CPUs at the same time */
 struct notifier_block uml_inetaddr_notifier = {
 	.notifier_call		= uml_inetaddr_event,
 };
@@ -727,7 +724,7 @@ struct notifier_block uml_inetaddr_notifier = {
 static int uml_net_init(void)
 {
 	struct list_head *ele;
-	struct uml_net_private *lp;	
+	struct uml_net_private *lp;
 	struct in_device *ip;
 	struct in_ifaddr *in;
 
@@ -738,18 +735,21 @@ static int uml_net_init(void)
 	 * didn't get a chance to run for them.  This fakes it so that
 	 * addresses which have already been set up get handled properly.
 	 */
+	spin_lock(&opened_lock);
 	list_for_each(ele, &opened){
 		lp = list_entry(ele, struct uml_net_private, list);
 		ip = lp->dev->ip_ptr;
-		if(ip == NULL) continue;
+		if(ip == NULL)
+			continue;
 		in = ip->ifa_list;
 		while(in != NULL){
 			uml_inetaddr_event(NULL, NETDEV_UP, in);
 			in = in->ifa_next;
 		}
-	}	
+	}
+	spin_unlock(&opened_lock);
 
-	return(0);
+	return 0;
 }
 
 __initcall(uml_net_init);
@@ -759,13 +759,16 @@ static void close_devices(void)
 	struct list_head *ele;
 	struct uml_net_private *lp;
 
+	spin_lock(&opened_lock);
 	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);
+		if(lp->remove != NULL)
+			(*lp->remove)(&lp->user);
 	}
+	spin_unlock(&opened_lock);
 }
 
 __uml_exitcall(close_devices);
@@ -783,8 +786,8 @@ struct sk_buff *ether_adjust_skb(struct sk_buff *skb, int extra)
 	return(skb);
 }
 
-void iter_addresses(void *d, void (*cb)(unsigned char *, unsigned char *, 
-					void *), 
+void iter_addresses(void *d, void (*cb)(unsigned char *, unsigned char *,
+					void *),
 		    void *arg)
 {
 	struct net_device *dev = d;
@@ -809,11 +812,11 @@ int dev_netmask(void *d, void *m)
 	struct in_ifaddr *in;
 	__be32 *mask_out = m;
 
-	if(ip == NULL) 
+	if(ip == NULL)
 		return(1);
 
 	in = ip->ifa_list;
-	if(in == NULL) 
+	if(in == NULL)
 		return(1);
 
 	*mask_out = in->ifa_mask;
@@ -827,7 +830,7 @@ void *get_output_buffer(int *len_out)
 	ret = (void *) __get_free_pages(GFP_KERNEL, 0);
 	if(ret) *len_out = PAGE_SIZE;
 	else *len_out = 0;
-	return(ret);
+	return ret;
 }
 
 void free_output_buffer(void *buffer)
@@ -835,7 +838,7 @@ void free_output_buffer(void *buffer)
 	free_pages((unsigned long) buffer, 0);
 }
 
-int tap_setup_common(char *str, char *type, char **dev_name, char **mac_out, 
+int tap_setup_common(char *str, char *type, char **dev_name, char **mac_out,
 		     char **gate_addr)
 {
 	char *remain;
@@ -854,14 +857,3 @@ unsigned short eth_protocol(struct sk_buff *skb)
 {
 	return(eth_type_trans(skb, skb->dev));
 }
-
-/*
- * 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/port_kern.c b/arch/um/drivers/port_kern.c
index 6dfe632f1c1..1c8efd95c42 100644
--- a/arch/um/drivers/port_kern.c
+++ b/arch/um/drivers/port_kern.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -55,9 +55,9 @@ static irqreturn_t pipe_interrupt(int irq, void *data)
 	fd = os_rcv_fd(conn->socket[0], &conn->helper_pid);
 	if(fd < 0){
 		if(fd == -EAGAIN)
-			return(IRQ_NONE);
+			return IRQ_NONE;
 
-		printk(KERN_ERR "pipe_interrupt : os_rcv_fd returned %d\n", 
+		printk(KERN_ERR "pipe_interrupt : os_rcv_fd returned %d\n",
 		       -fd);
 		os_close_file(conn->fd);
 	}
@@ -68,7 +68,7 @@ static irqreturn_t pipe_interrupt(int irq, void *data)
 	list_add(&conn->list, &conn->port->connections);
 
 	complete(&conn->port->done);
-	return(IRQ_HANDLED);
+	return IRQ_HANDLED;
 }
 
 #define NO_WAITER_MSG \
@@ -97,14 +97,14 @@ static int port_accept(struct port_list *port)
 		       "connection\n");
 		goto out_close;
 	}
-	*conn = ((struct connection) 
+	*conn = ((struct connection)
 		{ .list 	= LIST_HEAD_INIT(conn->list),
 		  .fd 		= fd,
 		  .socket  	= { socket[0], socket[1] },
 		  .telnetd_pid 	= pid,
 		  .port 	= port });
 
-	if(um_request_irq(TELNETD_IRQ, socket[0], IRQ_READ, pipe_interrupt, 
+	if(um_request_irq(TELNETD_IRQ, socket[0], IRQ_READ, pipe_interrupt,
 			  IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
 			  "telnetd", conn)){
 		printk(KERN_ERR "port_accept : failed to get IRQ for "
@@ -117,20 +117,20 @@ static int port_accept(struct port_list *port)
 		printk("No one waiting for port\n");
 	}
 	list_add(&conn->list, &port->pending);
-	return(1);
+	return 1;
 
  out_free:
 	kfree(conn);
  out_close:
 	os_close_file(fd);
-	if(pid != -1) 
+	if(pid != -1)
 		os_kill_process(pid, 1);
  out:
-	return(ret);
-} 
+	return ret;
+}
 
-DECLARE_MUTEX(ports_sem);
-struct list_head ports = LIST_HEAD_INIT(ports);
+static DECLARE_MUTEX(ports_sem);
+static LIST_HEAD(ports);
 
 void port_work_proc(struct work_struct *unused)
 {
@@ -158,8 +158,8 @@ static irqreturn_t port_interrupt(int irq, void *data)
 
 	port->has_connection = 1;
 	schedule_work(&port_work);
-	return(IRQ_HANDLED);
-} 
+	return IRQ_HANDLED;
+}
 
 void *port_data(int port_num)
 {
@@ -185,14 +185,14 @@ void *port_data(int port_num)
 		       port_num, -fd);
 		goto out_free;
 	}
-	if(um_request_irq(ACCEPT_IRQ, fd, IRQ_READ, port_interrupt, 
-			  IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM, "port",
-			  port)){
+	if(um_request_irq(ACCEPT_IRQ, fd, IRQ_READ, port_interrupt,
+			  IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
+			  "port", port)){
 		printk(KERN_ERR "Failed to get IRQ for port %d\n", port_num);
 		goto out_close;
 	}
 
-	*port = ((struct port_list) 
+	*port = ((struct port_list)
 		{ .list 	 	= LIST_HEAD_INIT(port->list),
 		  .wait_count		= ATOMIC_INIT(0),
 		  .has_connection 	= 0,
@@ -222,7 +222,7 @@ void *port_data(int port_num)
 	os_close_file(fd);
  out:
 	up(&ports_sem);
-	return(dev);
+	return dev;
 }
 
 int port_wait(void *data)
@@ -232,15 +232,15 @@ int port_wait(void *data)
 	struct port_list *port = dev->port;
 	int fd;
 
-        atomic_inc(&port->wait_count);
+	atomic_inc(&port->wait_count);
 	while(1){
 		fd = -ERESTARTSYS;
-                if(wait_for_completion_interruptible(&port->done))
-                        goto out;
+		if(wait_for_completion_interruptible(&port->done))
+			goto out;
 
 		spin_lock(&port->lock);
 
-		conn = list_entry(port->connections.next, struct connection, 
+		conn = list_entry(port->connections.next, struct connection,
 				  list);
 		list_del(&conn->list);
 		spin_unlock(&port->lock);
@@ -248,12 +248,12 @@ int port_wait(void *data)
 		os_shutdown_socket(conn->socket[0], 1, 1);
 		os_close_file(conn->socket[0]);
 		os_shutdown_socket(conn->socket[1], 1, 1);
-		os_close_file(conn->socket[1]);	
+		os_close_file(conn->socket[1]);
 
 		/* This is done here because freeing an IRQ can't be done
 		 * within the IRQ handler.  So, pipe_interrupt always ups
 		 * the semaphore regardless of whether it got a successful
-		 * connection.  Then we loop here throwing out failed 
+		 * connection.  Then we loop here throwing out failed
 		 * connections until a good one is found.
 		 */
 		free_irq(TELNETD_IRQ, conn);
diff --git a/arch/um/drivers/port_user.c b/arch/um/drivers/port_user.c
index bc6afaf74c1..80508023054 100644
--- a/arch/um/drivers/port_user.c
+++ b/arch/um/drivers/port_user.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2001 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -38,18 +38,18 @@ static void *port_init(char *str, int device, const struct chan_opts *opts)
 	if(*str != ':'){
 		printk("port_init : channel type 'port' must specify a "
 		       "port number\n");
-		return(NULL);
+		return NULL;
 	}
 	str++;
 	port = strtoul(str, &end, 0);
 	if((*end != '\0') || (end == str)){
 		printk("port_init : couldn't parse port '%s'\n", str);
-		return(NULL);
+		return NULL;
 	}
 
 	kern_data = port_data(port);
 	if(kern_data == NULL)
-		return(NULL);
+		return NULL;
 
 	data = um_kmalloc(sizeof(*data));
 	if(data == NULL)
@@ -59,10 +59,10 @@ static void *port_init(char *str, int device, const struct chan_opts *opts)
 				      .kernel_data 	= kern_data });
 	sprintf(data->dev, "%d", port);
 
-	return(data);
+	return data;
  err:
 	port_kern_free(kern_data);
-	return(NULL);
+	return NULL;
 }
 
 static void port_free(void *d)
@@ -83,14 +83,14 @@ static int port_open(int input, int output, int primary, void *d,
 	if((fd >= 0) && data->raw){
 		CATCH_EINTR(err = tcgetattr(fd, &data->tt));
 		if(err)
-			return(err);
+			return err;
 
 		err = raw(fd);
 		if(err)
-			return(err);
+			return err;
 	}
 	*dev_out = data->dev;
-	return(fd);
+	return fd;
 }
 
 static void port_close(int fd, void *d)
@@ -120,8 +120,8 @@ int port_listen_fd(int port)
 	int fd, err, arg;
 
 	fd = socket(PF_INET, SOCK_STREAM, 0);
-	if(fd == -1) 
-		return(-errno);
+	if(fd == -1)
+		return -errno;
 
 	arg = 1;
 	if(setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &arg, sizeof(arg)) < 0){
@@ -136,7 +136,7 @@ int port_listen_fd(int port)
 		err = -errno;
 		goto out;
 	}
-  
+
 	if(listen(fd, 1) < 0){
 		err = -errno;
 		goto out;
@@ -146,10 +146,10 @@ int port_listen_fd(int port)
 	if(err < 0)
 		goto out;
 
-	return(fd);
+	return fd;
  out:
 	os_close_file(fd);
-	return(err);
+	return err;
 }
 
 struct port_pre_exec_data {
@@ -173,13 +173,13 @@ void port_pre_exec(void *arg)
 int port_connection(int fd, int *socket, int *pid_out)
 {
 	int new, err;
-	char *argv[] = { "/usr/sbin/in.telnetd", "-L", 
+	char *argv[] = { "/usr/sbin/in.telnetd", "-L",
 			 "/usr/lib/uml/port-helper", NULL };
 	struct port_pre_exec_data data;
 
 	new = os_accept_connection(fd);
 	if(new < 0)
-		return(new);
+		return new;
 
 	err = os_pipe(socket, 0, 0);
 	if(err < 0)
@@ -190,29 +190,18 @@ int port_connection(int fd, int *socket, int *pid_out)
 		  .pipe_fd 		= socket[1] });
 
 	err = run_helper(port_pre_exec, &data, argv, NULL);
-	if(err < 0) 
+	if(err < 0)
 		goto out_shutdown;
 
 	*pid_out = err;
-	return(new);
+	return new;
 
  out_shutdown:
 	os_shutdown_socket(socket[0], 1, 1);
 	os_close_file(socket[0]);
-	os_shutdown_socket(socket[1], 1, 1);	
+	os_shutdown_socket(socket[1], 1, 1);
 	os_close_file(socket[1]);
  out_close:
 	os_close_file(new);
-	return(err);
+	return err;
 }
-
-/*
- * 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/random.c b/arch/um/drivers/random.c
index 73b2bdd6d2d..e942e836f99 100644
--- a/arch/um/drivers/random.c
+++ b/arch/um/drivers/random.c
@@ -78,6 +78,7 @@ static const struct file_operations rng_chrdev_ops = {
 	.read		= rng_dev_read,
 };
 
+/* rng_init shouldn't be called more than once at boot time */
 static struct miscdevice rng_miscdev = {
 	RNG_MISCDEV_MINOR,
 	RNG_MODULE_NAME,
diff --git a/arch/um/drivers/ssl.c b/arch/um/drivers/ssl.c
index ed9c59082d0..fc22b9bd915 100644
--- a/arch/um/drivers/ssl.c
+++ b/arch/um/drivers/ssl.c
@@ -38,6 +38,7 @@ static void ssl_announce(char *dev_name, int dev)
 	       dev_name);
 }
 
+/* Almost const, except that xterm_title may be changed in an initcall */
 static struct chan_opts opts = {
 	.announce 	= ssl_announce,
 	.xterm_title	= "Serial Line #%d",
@@ -46,10 +47,12 @@ static struct chan_opts opts = {
 	.in_kernel 	= 1,
 };
 
-static int ssl_config(char *str);
+static int ssl_config(char *str, char **error_out);
 static int ssl_get_config(char *dev, char *str, int size, char **error_out);
-static int ssl_remove(int n);
+static int ssl_remove(int n, char **error_out);
 
+
+/* Const, except for .mc.list */
 static struct line_driver driver = {
 	.name 			= "UML serial line",
 	.device_name 		= "ttyS",
@@ -61,9 +64,8 @@ static struct line_driver driver = {
 	.read_irq_name 		= "ssl",
 	.write_irq 		= SSL_WRITE_IRQ,
 	.write_irq_name 	= "ssl-write",
-	.symlink_from 		= "serial",
-	.symlink_to 		= "tts",
 	.mc  = {
+		.list		= LIST_HEAD_INIT(driver.mc.list),
 		.name  		= "ssl",
 		.config 	= ssl_config,
 		.get_config 	= ssl_get_config,
@@ -72,17 +74,16 @@ static struct line_driver driver = {
 	},
 };
 
-/* The array is initialized by line_init, which is an initcall.  The 
- * individual elements are protected by individual semaphores.
+/* The array is initialized by line_init, at initcall time.  The
+ * elements are locked individually as needed.
  */
 static struct line serial_lines[NR_PORTS] =
 	{ [0 ... NR_PORTS - 1] = LINE_INIT(CONFIG_SSL_CHAN, &driver) };
 
-static struct lines lines = LINES_INIT(NR_PORTS);
-
-static int ssl_config(char *str)
+static int ssl_config(char *str, char **error_out)
 {
-	return line_config(serial_lines, ARRAY_SIZE(serial_lines), str, &opts);
+	return line_config(serial_lines, ARRAY_SIZE(serial_lines), str, &opts,
+			   error_out);
 }
 
 static int ssl_get_config(char *dev, char *str, int size, char **error_out)
@@ -91,9 +92,10 @@ static int ssl_get_config(char *dev, char *str, int size, char **error_out)
 			       size, error_out);
 }
 
-static int ssl_remove(int n)
+static int ssl_remove(int n, char **error_out)
 {
-	return line_remove(serial_lines, ARRAY_SIZE(serial_lines), n);
+	return line_remove(serial_lines, ARRAY_SIZE(serial_lines), n,
+			   error_out);
 }
 
 static int ssl_open(struct tty_struct *tty, struct file *filp)
@@ -168,9 +170,10 @@ 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);
 }
 
+/* No locking for register_console call - relies on single-threaded initcalls */
 static struct console ssl_cons = {
 	.name		= "ttyS",
 	.write		= ssl_console_write,
@@ -186,9 +189,8 @@ static int ssl_init(void)
 
 	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));
+	ssl_driver = register_lines(&driver, &ssl_ops, serial_lines,
+				    ARRAY_SIZE(serial_lines));
 
 	lines_init(serial_lines, ARRAY_SIZE(serial_lines), &opts);
 
@@ -212,7 +214,15 @@ __uml_exitcall(ssl_exit);
 
 static int ssl_chan_setup(char *str)
 {
-	return line_setup(serial_lines, ARRAY_SIZE(serial_lines), str);
+	char *error;
+	int ret;
+
+	ret = line_setup(serial_lines, ARRAY_SIZE(serial_lines), str, &error);
+	if(ret < 0)
+		printk(KERN_ERR "Failed to set up serial line with "
+		       "configuration string \"%s\" : %s\n", str, error);
+
+	return 1;
 }
 
 __setup("ssl", ssl_chan_setup);
diff --git a/arch/um/drivers/stdio_console.c b/arch/um/drivers/stdio_console.c
index 7a4897e27f4..7ff0b0fc37e 100644
--- a/arch/um/drivers/stdio_console.c
+++ b/arch/um/drivers/stdio_console.c
@@ -30,8 +30,6 @@
 
 #define MAX_TTYS (16)
 
-/* ----------------------------------------------------------------------------- */
-
 /* Referenced only by tty_driver below - presumably it's locked correctly
  * by the tty driver.
  */
@@ -44,6 +42,7 @@ void stdio_announce(char *dev_name, int dev)
 	       dev_name);
 }
 
+/* Almost const, except that xterm_title may be changed in an initcall */
 static struct chan_opts opts = {
 	.announce 	= stdio_announce,
 	.xterm_title	= "Virtual Console #%d",
@@ -52,10 +51,12 @@ static struct chan_opts opts = {
 	.in_kernel 	= 1,
 };
 
-static int con_config(char *str);
+static int con_config(char *str, char **error_out);
 static int con_get_config(char *dev, char *str, int size, char **error_out);
-static int con_remove(int n);
+static int con_remove(int n, char **con_remove);
+
 
+/* Const, except for .mc.list */
 static struct line_driver driver = {
 	.name 			= "UML console",
 	.device_name 		= "tty",
@@ -67,9 +68,8 @@ static struct line_driver driver = {
 	.read_irq_name 		= "console",
 	.write_irq 		= CONSOLE_WRITE_IRQ,
 	.write_irq_name 	= "console-write",
-	.symlink_from 		= "ttys",
-	.symlink_to 		= "vc",
 	.mc  = {
+		.list		= LIST_HEAD_INIT(driver.mc.list),
 		.name  		= "con",
 		.config 	= con_config,
 		.get_config 	= con_get_config,
@@ -78,18 +78,16 @@ static struct line_driver driver = {
 	},
 };
 
-static struct lines console_lines = LINES_INIT(MAX_TTYS);
-
-/* The array is initialized by line_init, which is an initcall.  The 
- * individual elements are protected by individual semaphores.
+/* The array is initialized by line_init, at initcall time.  The
+ * elements are locked individually as needed.
  */
-struct line vts[MAX_TTYS] = { LINE_INIT(CONFIG_CON_ZERO_CHAN, &driver),
-			      [ 1 ... MAX_TTYS - 1 ] =
-			      LINE_INIT(CONFIG_CON_CHAN, &driver) };
+static struct line vts[MAX_TTYS] = { LINE_INIT(CONFIG_CON_ZERO_CHAN, &driver),
+				     [ 1 ... MAX_TTYS - 1 ] =
+				     LINE_INIT(CONFIG_CON_CHAN, &driver) };
 
-static int con_config(char *str)
+static int con_config(char *str, char **error_out)
 {
-	return line_config(vts, ARRAY_SIZE(vts), str, &opts);
+	return line_config(vts, ARRAY_SIZE(vts), str, &opts, error_out);
 }
 
 static int con_get_config(char *dev, char *str, int size, char **error_out)
@@ -97,9 +95,9 @@ static int con_get_config(char *dev, char *str, int size, char **error_out)
 	return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out);
 }
 
-static int con_remove(int n)
+static int con_remove(int n, char **error_out)
 {
-	return line_remove(vts, ARRAY_SIZE(vts), n);
+	return line_remove(vts, ARRAY_SIZE(vts), n, error_out);
 }
 
 static int con_open(struct tty_struct *tty, struct file *filp)
@@ -146,9 +144,10 @@ 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);
 }
 
+/* No locking for register_console call - relies on single-threaded initcalls */
 static struct console stdiocons = {
 	.name		= "tty",
 	.write		= uml_console_write,
@@ -156,16 +155,14 @@ static struct console stdiocons = {
 	.setup		= uml_console_setup,
 	.flags		= CON_PRINTBUFFER,
 	.index		= -1,
-	.data		= &vts,
 };
 
 int stdio_init(void)
 {
 	char *new_title;
 
-	console_driver = line_register_devfs(&console_lines, &driver,
-					     &console_ops, vts,
-					     ARRAY_SIZE(vts));
+	console_driver = register_lines(&driver, &console_ops, vts,
+					ARRAY_SIZE(vts));
 	if (console_driver == NULL)
 		return -1;
 	printk(KERN_INFO "Initialized stdio console driver\n");
@@ -192,7 +189,15 @@ __uml_exitcall(console_exit);
 
 static int console_chan_setup(char *str)
 {
-	return line_setup(vts, ARRAY_SIZE(vts), str);
+	char *error;
+	int ret;
+
+	ret = line_setup(vts, ARRAY_SIZE(vts), str, &error);
+	if(ret < 0)
+		printk(KERN_ERR "Failed to set up console with "
+		       "configuration string \"%s\" : %s\n", str, error);
+
+	return 1;
 }
 __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 49c047b75cc..f98d26e5138 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -56,6 +56,7 @@
 enum ubd_req { UBD_READ, UBD_WRITE };
 
 struct io_thread_req {
+	struct request *req;
 	enum ubd_req op;
 	int fds[2];
 	unsigned long offsets[2];
@@ -106,10 +107,6 @@ static inline void ubd_set_bit(__u64 bit, unsigned char *data)
 
 #define DRIVER_NAME "uml-blkdev"
 
-/* Can be taken in interrupt context, and is passed to the block layer to lock
- * the request queue. Kernel side code knows that. */
-static DEFINE_SPINLOCK(ubd_io_lock);
-
 static DEFINE_MUTEX(ubd_lock);
 
 /* XXX - this made sense in 2.4 days, now it's only used as a boolean, and
@@ -132,12 +129,8 @@ static struct block_device_operations ubd_blops = {
 	.getgeo		= ubd_getgeo,
 };
 
-/* Protected by the queue_lock */
-static request_queue_t *ubd_queue;
-
 /* Protected by ubd_lock */
 static int fake_major = MAJOR_NR;
-
 static struct gendisk *ubd_gendisk[MAX_DEV];
 static struct gendisk *fake_gendisk[MAX_DEV];
 
@@ -148,10 +141,6 @@ static struct gendisk *fake_gendisk[MAX_DEV];
 #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \
 					 .cl = 1 })
 #endif
-
-/* Not protected - changed only in ubd_setup_common and then only to
- * to enable O_SYNC.
- */
 static struct openflags global_openflags = OPEN_FLAGS;
 
 struct cow {
@@ -178,6 +167,8 @@ struct ubd {
 	unsigned no_cow:1;
 	struct cow cow;
 	struct platform_device pdev;
+	struct request_queue *queue;
+	spinlock_t lock;
 };
 
 #define DEFAULT_COW { \
@@ -198,8 +189,10 @@ struct ubd {
         .no_cow =               0, \
 	.shared =		0, \
         .cow =			DEFAULT_COW, \
+	.lock =			SPIN_LOCK_UNLOCKED,	\
 }
 
+/* Protected by ubd_lock */
 struct ubd ubd_devs[MAX_DEV] = { [ 0 ... MAX_DEV - 1 ] = DEFAULT_UBD };
 
 /* Only changed by fake_ide_setup which is a setup */
@@ -242,7 +235,6 @@ static void make_ide_entries(char *dev_name)
 
 	ent = create_proc_entry("media", S_IFREG|S_IRUGO, dir);
 	if(!ent) return;
-	ent->nlink = 1;
 	ent->data = NULL;
 	ent->read_proc = proc_ide_read_media;
 	ent->write_proc = NULL;
@@ -286,12 +278,12 @@ static int parse_unit(char **ptr)
  * otherwise, the str pointer is used (and owned) inside ubd_devs array, so it
  * should not be freed on exit.
  */
-static int ubd_setup_common(char *str, int *index_out)
+static int ubd_setup_common(char *str, int *index_out, char **error_out)
 {
 	struct ubd *ubd_dev;
 	struct openflags flags = global_openflags;
 	char *backing_file;
-	int n, err, i;
+	int n, err = 0, i;
 
 	if(index_out) *index_out = -1;
 	n = *str;
@@ -302,56 +294,55 @@ static int ubd_setup_common(char *str, int *index_out)
 		str++;
 		if(!strcmp(str, "sync")){
 			global_openflags = of_sync(global_openflags);
-			return(0);
+			goto out1;
 		}
+
+		err = -EINVAL;
 		major = simple_strtoul(str, &end, 0);
 		if((*end != '\0') || (end == str)){
-			printk(KERN_ERR
-			       "ubd_setup : didn't parse major number\n");
-			return(1);
+			*error_out = "Didn't parse major number";
+			goto out1;
 		}
 
-		err = 1;
- 		mutex_lock(&ubd_lock);
- 		if(fake_major != MAJOR_NR){
- 			printk(KERN_ERR "Can't assign a fake major twice\n");
- 			goto out1;
- 		}
+		mutex_lock(&ubd_lock);
+		if(fake_major != MAJOR_NR){
+			*error_out = "Can't assign a fake major twice";
+			goto out1;
+		}
 
- 		fake_major = major;
+		fake_major = major;
 
 		printk(KERN_INFO "Setting extra ubd major number to %d\n",
 		       major);
- 		err = 0;
- 	out1:
- 		mutex_unlock(&ubd_lock);
-		return(err);
+		err = 0;
+	out1:
+		mutex_unlock(&ubd_lock);
+		return err;
 	}
 
 	n = parse_unit(&str);
 	if(n < 0){
-		printk(KERN_ERR "ubd_setup : couldn't parse unit number "
-		       "'%s'\n", str);
-		return(1);
+		*error_out = "Couldn't parse device number";
+		return -EINVAL;
 	}
 	if(n >= MAX_DEV){
-		printk(KERN_ERR "ubd_setup : index %d out of range "
-		       "(%d devices, from 0 to %d)\n", n, MAX_DEV, MAX_DEV - 1);
-		return(1);
+		*error_out = "Device number out of range";
+		return 1;
 	}
 
-	err = 1;
+	err = -EBUSY;
 	mutex_lock(&ubd_lock);
 
 	ubd_dev = &ubd_devs[n];
 	if(ubd_dev->file != NULL){
-		printk(KERN_ERR "ubd_setup : device already configured\n");
+		*error_out = "Device is already configured";
 		goto out;
 	}
 
 	if (index_out)
 		*index_out = n;
 
+	err = -EINVAL;
 	for (i = 0; i < sizeof("rscd="); i++) {
 		switch (*str) {
 		case 'r':
@@ -370,47 +361,54 @@ static int ubd_setup_common(char *str, int *index_out)
 			str++;
 			goto break_loop;
 		default:
-			printk(KERN_ERR "ubd_setup : Expected '=' or flag letter (r, s, c, or d)\n");
+			*error_out = "Expected '=' or flag letter "
+				"(r, s, c, or d)";
 			goto out;
 		}
 		str++;
 	}
 
-        if (*str == '=')
-		printk(KERN_ERR "ubd_setup : Too many flags specified\n");
-        else
-		printk(KERN_ERR "ubd_setup : Expected '='\n");
+	if (*str == '=')
+		*error_out = "Too many flags specified";
+	else
+		*error_out = "Missing '='";
 	goto out;
 
 break_loop:
-	err = 0;
 	backing_file = strchr(str, ',');
 
-	if (!backing_file) {
+	if (backing_file == NULL)
 		backing_file = strchr(str, ':');
-	}
 
-	if(backing_file){
-		if(ubd_dev->no_cow)
-			printk(KERN_ERR "Can't specify both 'd' and a "
-			       "cow file\n");
+	if(backing_file != NULL){
+		if(ubd_dev->no_cow){
+			*error_out = "Can't specify both 'd' and a cow file";
+			goto out;
+		}
 		else {
 			*backing_file = '\0';
 			backing_file++;
 		}
 	}
+	err = 0;
 	ubd_dev->file = str;
 	ubd_dev->cow.file = backing_file;
 	ubd_dev->boot_openflags = flags;
 out:
 	mutex_unlock(&ubd_lock);
-	return(err);
+	return err;
 }
 
 static int ubd_setup(char *str)
 {
-	ubd_setup_common(str, NULL);
-	return(1);
+	char *error;
+	int err;
+
+	err = ubd_setup_common(str, NULL, &error);
+	if(err)
+		printk(KERN_ERR "Failed to initialize device with \"%s\" : "
+		       "%s\n", str, error);
+	return 1;
 }
 
 __setup("ubd", ubd_setup);
@@ -422,7 +420,7 @@ __uml_help(ubd_setup,
 "    use either a ':' or a ',': the first one allows writing things like;\n"
 "	ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n"
 "    while with a ',' the shell would not expand the 2nd '~'.\n"
-"    When using only one filename, UML will detect whether to thread it like\n"
+"    When using only one filename, UML will detect whether to treat it like\n"
 "    a COW file or a backing file. To override this detection, add the 'd'\n"
 "    flag:\n"
 "	ubd0d=BackingFile\n"
@@ -471,12 +469,6 @@ static void do_ubd_request(request_queue_t * q);
 /* Only changed by ubd_init, which is an initcall. */
 int thread_fd = -1;
 
-/* Changed by ubd_handler, which is serialized because interrupts only
- * happen on CPU 0.
- * XXX: currently unused.
- */
-static int intr_count = 0;
-
 /* call ubd_finish if you need to serialize */
 static void __ubd_finish(struct request *req, int error)
 {
@@ -499,36 +491,38 @@ static void __ubd_finish(struct request *req, int error)
  * spin_lock_irq()/spin_lock_irqsave() */
 static inline void ubd_finish(struct request *req, int error)
 {
- 	spin_lock(&ubd_io_lock);
+	struct ubd *dev = req->rq_disk->private_data;
+
+	spin_lock(&dev->lock);
 	__ubd_finish(req, error);
-	spin_unlock(&ubd_io_lock);
+	spin_unlock(&dev->lock);
 }
 
 /* XXX - move this inside ubd_intr. */
-/* Called without ubd_io_lock held, and only in interrupt context. */
+/* Called without dev->lock held, and only in interrupt context. */
 static void ubd_handler(void)
 {
 	struct io_thread_req req;
-	struct request *rq = elv_next_request(ubd_queue);
+	struct request *rq;
+	struct ubd *dev;
 	int n;
 
 	do_ubd = 0;
-	intr_count++;
 	n = os_read_file(thread_fd, &req, sizeof(req));
 	if(n != sizeof(req)){
 		printk(KERN_ERR "Pid %d - spurious interrupt in ubd_handler, "
 		       "err = %d\n", os_getpid(), -n);
-		spin_lock(&ubd_io_lock);
-		end_request(rq, 0);
-		spin_unlock(&ubd_io_lock);
 		return;
 	}
 
+	rq = req.req;
+	dev = rq->rq_disk->private_data;
+
 	ubd_finish(rq, req.error);
-	reactivate_fd(thread_fd, UBD_IRQ);	
-	spin_lock(&ubd_io_lock);
-	do_ubd_request(ubd_queue);
-	spin_unlock(&ubd_io_lock);
+	reactivate_fd(thread_fd, UBD_IRQ);
+	spin_lock(&dev->lock);
+	do_ubd_request(dev->queue);
+	spin_unlock(&dev->lock);
 }
 
 static irqreturn_t ubd_intr(int irq, void *dev)
@@ -632,8 +626,7 @@ static int ubd_open_dev(struct ubd *ubd_dev)
 }
 
 static int ubd_disk_register(int major, u64 size, int unit,
-			struct gendisk **disk_out)
-			
+			     struct gendisk **disk_out)
 {
 	struct gendisk *disk;
 
@@ -659,7 +652,7 @@ static int ubd_disk_register(int major, u64 size, int unit,
 	}
 
 	disk->private_data = &ubd_devs[unit];
-	disk->queue = ubd_queue;
+	disk->queue = ubd_devs[unit].queue;
 	add_disk(disk);
 
 	*disk_out = disk;
@@ -668,28 +661,39 @@ static int ubd_disk_register(int major, u64 size, int unit,
 
 #define ROUND_BLOCK(n) ((n + ((1 << 9) - 1)) & (-1 << 9))
 
-static int ubd_add(int n)
+static int ubd_add(int n, char **error_out)
 {
 	struct ubd *ubd_dev = &ubd_devs[n];
-	int err;
+	int err = 0;
 
-	err = -ENODEV;
 	if(ubd_dev->file == NULL)
 		goto out;
 
 	err = ubd_file_size(ubd_dev, &ubd_dev->size);
-	if(err < 0)
+	if(err < 0){
+		*error_out = "Couldn't determine size of device's file";
 		goto out;
+	}
 
 	ubd_dev->size = ROUND_BLOCK(ubd_dev->size);
 
-	err = ubd_disk_register(MAJOR_NR, ubd_dev->size, n, &ubd_gendisk[n]);
-	if(err)
+	err = -ENOMEM;
+	ubd_dev->queue = blk_init_queue(do_ubd_request, &ubd_dev->lock);
+	if (ubd_dev->queue == NULL) {
+		*error_out = "Failed to initialize device queue";
 		goto out;
+	}
+	ubd_dev->queue->queuedata = ubd_dev;
+
+	err = ubd_disk_register(MAJOR_NR, ubd_dev->size, n, &ubd_gendisk[n]);
+	if(err){
+		*error_out = "Failed to register device";
+		goto out_cleanup;
+	}
 
 	if(fake_major != MAJOR_NR)
 		ubd_disk_register(fake_major, ubd_dev->size, n,
-			     &fake_gendisk[n]);
+				  &fake_gendisk[n]);
 
 	/* perhaps this should also be under the "if (fake_major)" above */
 	/* using the fake_disk->disk_name and also the fakehd_set name */
@@ -699,30 +703,37 @@ static int ubd_add(int n)
 	err = 0;
 out:
 	return err;
+
+out_cleanup:
+	blk_cleanup_queue(ubd_dev->queue);
+	goto out;
 }
 
-static int ubd_config(char *str)
+static int ubd_config(char *str, char **error_out)
 {
 	int n, ret;
 
+	/* This string is possibly broken up and stored, so it's only
+	 * freed if ubd_setup_common fails, or if only general options
+	 * were set.
+	 */
 	str = kstrdup(str, GFP_KERNEL);
 	if (str == NULL) {
-		printk(KERN_ERR "ubd_config failed to strdup string\n");
-		ret = 1;
-		goto out;
+		*error_out = "Failed to allocate memory";
+		return -ENOMEM;
 	}
-	ret = ubd_setup_common(str, &n);
-	if (ret) {
-		ret = -1;
+
+	ret = ubd_setup_common(str, &n, error_out);
+	if (ret)
 		goto err_free;
-	}
+
 	if (n == -1) {
 		ret = 0;
 		goto err_free;
 	}
 
  	mutex_lock(&ubd_lock);
-	ret = ubd_add(n);
+	ret = ubd_add(n, error_out);
 	if (ret)
 		ubd_devs[n].file = NULL;
  	mutex_unlock(&ubd_lock);
@@ -777,7 +788,7 @@ static int ubd_id(char **str, int *start_out, int *end_out)
         return n;
 }
 
-static int ubd_remove(int n)
+static int ubd_remove(int n, char **error_out)
 {
 	struct ubd *ubd_dev;
 	int err = -ENODEV;
@@ -807,6 +818,7 @@ static int ubd_remove(int n)
 		fake_gendisk[n] = NULL;
 	}
 
+	blk_cleanup_queue(ubd_dev->queue);
 	platform_device_unregister(&ubd_dev->pdev);
 	*ubd_dev = ((struct ubd) DEFAULT_UBD);
 	err = 0;
@@ -815,8 +827,11 @@ out:
 	return err;
 }
 
-/* All these are called by mconsole in process context and without ubd-specific locks. */
+/* All these are called by mconsole in process context and without
+ * ubd-specific locks.  The structure itself is const except for .list.
+ */
 static struct mc_device ubd_mc = {
+	.list		= LIST_HEAD_INIT(ubd_mc.list),
 	.name		= "ubd",
 	.config		= ubd_config,
  	.get_config	= ubd_get_config,
@@ -836,13 +851,17 @@ static int __init ubd0_init(void)
 {
 	struct ubd *ubd_dev = &ubd_devs[0];
 
+	mutex_lock(&ubd_lock);
 	if(ubd_dev->file == NULL)
 		ubd_dev->file = "root_fs";
+	mutex_unlock(&ubd_lock);
+
 	return(0);
 }
 
 __initcall(ubd0_init);
 
+/* Used in ubd_init, which is an initcall */
 static struct platform_driver ubd_driver = {
 	.driver = {
 		.name  = DRIVER_NAME,
@@ -851,17 +870,12 @@ static struct platform_driver ubd_driver = {
 
 static int __init ubd_init(void)
 {
-        int i;
+	char *error;
+	int i, err;
 
 	if (register_blkdev(MAJOR_NR, "ubd"))
 		return -1;
 
-	ubd_queue = blk_init_queue(do_ubd_request, &ubd_io_lock);
-	if (!ubd_queue) {
-		unregister_blkdev(MAJOR_NR, "ubd");
-		return -1;
-	}
-		
 	if (fake_major != MAJOR_NR) {
 		char name[sizeof("ubd_nnn\0")];
 
@@ -870,8 +884,14 @@ static int __init ubd_init(void)
 			return -1;
 	}
 	platform_driver_register(&ubd_driver);
-	for (i = 0; i < MAX_DEV; i++)
-		ubd_add(i);
+ 	mutex_lock(&ubd_lock);
+	for (i = 0; i < MAX_DEV; i++){
+		err = ubd_add(i, &error);
+		if(err)
+			printk(KERN_ERR "Failed to initialize ubd device %d :"
+			       "%s\n", i, error);
+	}
+ 	mutex_unlock(&ubd_lock);
 	return 0;
 }
 
@@ -1003,7 +1023,7 @@ static void cowify_req(struct io_thread_req *req, unsigned long *bitmap,
 			   req->bitmap_words, bitmap_len);
 }
 
-/* Called with ubd_io_lock held */
+/* Called with dev->lock held */
 static int prepare_request(struct request *req, struct io_thread_req *io_req)
 {
 	struct gendisk *disk = req->rq_disk;
@@ -1022,6 +1042,7 @@ static int prepare_request(struct request *req, struct io_thread_req *io_req)
 	offset = ((__u64) req->sector) << 9;
 	len = req->current_nr_sectors << 9;
 
+	io_req->req = req;
 	io_req->fds[0] = (ubd_dev->cow.file != NULL) ? ubd_dev->cow.fd : ubd_dev->fd;
 	io_req->fds[1] = ubd_dev->fd;
 	io_req->cow_offset = -1;
@@ -1043,7 +1064,7 @@ static int prepare_request(struct request *req, struct io_thread_req *io_req)
 	return(0);
 }
 
-/* Called with ubd_io_lock held */
+/* Called with dev->lock held */
 static void do_ubd_request(request_queue_t *q)
 {
 	struct io_thread_req io_req;
@@ -1102,7 +1123,7 @@ static int ubd_ioctl(struct inode * inode, struct file * file,
 				 sizeof(ubd_id)))
 			return(-EFAULT);
 		return(0);
-		
+
 	case CDROMVOLREAD:
 		if(copy_from_user(&volume, (char __user *) arg, sizeof(volume)))
 			return(-EFAULT);
diff --git a/arch/um/include/chan_kern.h b/arch/um/include/chan_kern.h
index 9003a343e14..c4b41bb1035 100644
--- a/arch/um/include/chan_kern.h
+++ b/arch/um/include/chan_kern.h
@@ -30,14 +30,13 @@ struct chan {
 extern void chan_interrupt(struct list_head *chans, struct delayed_work *task,
 			   struct tty_struct *tty, int irq);
 extern int parse_chan_pair(char *str, struct line *line, int device,
-			   const struct chan_opts *opts);
+			   const struct chan_opts *opts, char **error_out);
 extern int open_chan(struct list_head *chans);
 extern int write_chan(struct list_head *chans, const char *buf, int len,
 			     int write_irq);
 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,
-			     const struct chan_opts *opts);
+extern int console_open_chan(struct line *line, struct console *co);
 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);
diff --git a/arch/um/include/chan_user.h b/arch/um/include/chan_user.h
index a795547a1db..38f16d812e7 100644
--- a/arch/um/include/chan_user.h
+++ b/arch/um/include/chan_user.h
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -9,11 +9,11 @@
 #include "init.h"
 
 struct chan_opts {
-	void (*announce)(char *dev_name, int dev);
+	void (*const announce)(char *dev_name, int dev);
 	char *xterm_title;
-	int raw;
-	unsigned long tramp_stack;
-	int in_kernel;
+	const int raw;
+	const unsigned long tramp_stack;
+	const int in_kernel;
 };
 
 enum chan_init_pri { INIT_STATIC, INIT_ALL, INIT_ONE };
@@ -54,14 +54,3 @@ __uml_help(fn, prefix "[0-9]*=<channel description>\n" \
 );
 
 #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/kern_util.h b/arch/um/include/kern_util.h
index cec9fcc57bf..173af029d12 100644
--- a/arch/um/include/kern_util.h
+++ b/arch/um/include/kern_util.h
@@ -61,7 +61,6 @@ extern int set_signals(int enable);
 extern void force_sigbus(void);
 extern int pid_to_processor_id(int pid);
 extern void deliver_signals(void *t);
-extern int next_syscall_index(int max);
 extern int next_trap_index(int max);
 extern void default_idle(void);
 extern void finish_fork(void);
@@ -88,7 +87,6 @@ extern void timer_irq(union uml_pt_regs *regs);
 extern void unprotect_stack(unsigned long stack);
 extern void do_uml_exitcalls(void);
 extern int attach_debugger(int idle_pid, int pid, int stop);
-extern void bad_segv(struct faultinfo fi, unsigned long ip);
 extern int config_gdb(char *str);
 extern int remove_gdb(void);
 extern char *uml_strdup(char *string);
@@ -104,8 +102,6 @@ extern int clear_user_proc(void *buf, int size);
 extern int copy_to_user_proc(void *to, void *from, int size);
 extern int copy_from_user_proc(void *to, void *from, int size);
 extern int strlen_user_proc(char *str);
-extern void bus_handler(int sig, union uml_pt_regs *regs);
-extern void winch(int sig, union uml_pt_regs *regs);
 extern long execute_syscall(void *r);
 extern int smp_sigio_handler(void);
 extern void *get_current(void);
@@ -120,7 +116,6 @@ extern void time_init_kern(void);
 
 /* Are we disallowed to sleep? Used to choose between GFP_KERNEL and GFP_ATOMIC. */
 extern int __cant_sleep(void);
-extern void segv_handler(int sig, union uml_pt_regs *regs);
 extern void sigio_handler(int sig, union uml_pt_regs *regs);
 
 #endif
diff --git a/arch/um/include/line.h b/arch/um/include/line.h
index 5f232ae89fb..1223f2c844b 100644
--- a/arch/um/include/line.h
+++ b/arch/um/include/line.h
@@ -11,36 +11,37 @@
 #include "linux/tty.h"
 #include "linux/interrupt.h"
 #include "linux/spinlock.h"
+#include "linux/mutex.h"
 #include "chan_user.h"
 #include "mconsole_kern.h"
 
+/* There's only one modifiable field in this - .mc.list */
 struct line_driver {
-	char *name;
-	char *device_name;
-	short major;
-	short minor_start;
-	short type;
-	short subtype;
-	int read_irq;
-	char *read_irq_name;
-	int write_irq;
-	char *write_irq_name;
-	char *symlink_from;
-	char *symlink_to;
+	const char *name;
+	const char *device_name;
+	const short major;
+	const short minor_start;
+	const short type;
+	const short subtype;
+	const int read_irq;
+	const char *read_irq_name;
+	const int write_irq;
+	const char *write_irq_name;
 	struct mc_device mc;
 };
 
 struct line {
 	struct tty_struct *tty;
+	spinlock_t count_lock;
+	int valid;
+
 	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;
-
+	int throttled;
 	/* Yes, this is a real circular buffer.
 	 * XXX: And this should become a struct kfifo!
 	 *
@@ -57,22 +58,17 @@ struct line {
 };
 
 #define LINE_INIT(str, d) \
-	{ .init_str =	str, \
+	{ .count_lock =	SPIN_LOCK_UNLOCKED, \
+	  .init_str =	str,	\
 	  .init_pri =	INIT_STATIC, \
 	  .valid =	1, \
 	  .lock =	SPIN_LOCK_UNLOCKED, \
 	  .driver =	d }
 
-struct lines {
-	int num;
-};
-
-#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);
 extern int line_setup(struct line *lines, unsigned int sizeof_lines,
-		      char *init);
+		      char *init, char **error_out);
 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);
@@ -90,17 +86,18 @@ extern char *add_xterm_umid(char *base);
 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 struct tty_driver * line_register_devfs(struct lines *set,
-					       struct line_driver *line_driver,
-					       const struct tty_operations *driver,
-					       struct line *lines, int nlines);
+extern struct tty_driver *register_lines(struct line_driver *line_driver,
+					 const struct tty_operations *driver,
+					 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, const struct chan_opts *opts);
+		       char *str, const struct chan_opts *opts,
+		       char **error_out);
 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_remove(struct line *lines, unsigned int sizeof_lines, int n,
+		       char **error_out);
 extern int line_get_config(char *dev, struct line *lines,
 			   unsigned int sizeof_lines, char *str,
 			   int size, char **error_out);
diff --git a/arch/um/include/mconsole_kern.h b/arch/um/include/mconsole_kern.h
index 1ea6d928e1c..d2fe07e7895 100644
--- a/arch/um/include/mconsole_kern.h
+++ b/arch/um/include/mconsole_kern.h
@@ -18,10 +18,10 @@ struct mconsole_entry {
 struct mc_device {
 	struct list_head list;
 	char *name;
-	int (*config)(char *);
+	int (*config)(char *, char **);
 	int (*get_config)(char *, char *, int, char **);
-        int (*id)(char **, int *, int *);
-	int (*remove)(int);
+	int (*id)(char **, int *, int *);
+	int (*remove)(int, char **);
 };
 
 #define CONFIG_CHUNK(str, size, current, chunk, end) \
@@ -50,14 +50,3 @@ static inline void mconsole_register_dev(struct mc_device *new)
 #endif
 
 #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/net_kern.h b/arch/um/include/net_kern.h
index 218f8b47fdc..125ab42df18 100644
--- a/arch/um/include/net_kern.h
+++ b/arch/um/include/net_kern.h
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -36,7 +36,7 @@ struct uml_net_private {
 	void (*remove)(void *);
 	int (*read)(int, struct sk_buff **skb, struct uml_net_private *);
 	int (*write)(int, struct sk_buff **skb, struct uml_net_private *);
-	
+
 	void (*add_address)(unsigned char *, unsigned char *, void *);
 	void (*delete_address)(unsigned char *, unsigned char *, void *);
 	int (*set_mtu)(int mtu, void *);
@@ -52,18 +52,18 @@ struct net_kern_info {
 
 struct transport {
 	struct list_head list;
-	char *name;
-	int (*setup)(char *, char **, void *);
+	const char *name;
+	int (* const setup)(char *, char **, void *);
 	const struct net_user_info *user;
 	const struct net_kern_info *kern;
-	int private_size;
-	int setup_size;
+	const int private_size;
+	const int setup_size;
 };
 
 extern struct net_device *ether_init(int);
 extern unsigned short ether_protocol(struct sk_buff *);
 extern struct sk_buff *ether_adjust_skb(struct sk_buff *skb, int extra);
-extern int tap_setup_common(char *str, char *type, char **dev_name, 
+extern int tap_setup_common(char *str, char *type, char **dev_name,
 			    char **mac_out, char **gate_addr);
 extern void register_transport(struct transport *new);
 extern unsigned short eth_protocol(struct sk_buff *skb);
diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index 13a86bd383d..8629bd19149 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -137,7 +137,6 @@ extern int os_new_tty_pgrp(int fd, int pid);
 extern int os_get_ifname(int fd, char *namebuf);
 extern int os_set_slip(int fd);
 extern int os_set_owner(int fd, int pid);
-extern int os_sigio_async(int master, int slave);
 extern int os_mode_fd(int fd, int mode);
 
 extern int os_seek_file(int fd, __u64 offset);
@@ -341,4 +340,6 @@ extern void maybe_sigio_broken(int fd, int read);
 extern void sig_handler_common_skas(int sig, void *sc_ptr);
 extern void user_signal(int sig, union uml_pt_regs *regs, int pid);
 
+extern int os_arch_prctl(int pid, int code, unsigned long *addr);
+
 #endif
diff --git a/arch/um/include/sigio.h b/arch/um/include/sigio.h
index fe99ea163c2..434f1a9ae4b 100644
--- a/arch/um/include/sigio.h
+++ b/arch/um/include/sigio.h
@@ -12,14 +12,3 @@ extern void sigio_lock(void);
 extern void sigio_unlock(void);
 
 #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/tempfile.h b/arch/um/include/tempfile.h
index e36d9e0f510..d441eac936b 100644
--- a/arch/um/include/tempfile.h
+++ b/arch/um/include/tempfile.h
@@ -9,13 +9,3 @@
 extern int make_tempfile(const char *template, char **tempname, int do_unlink);
 
 #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/umid.h b/arch/um/include/umid.h
deleted file mode 100644
index 11373c851f1..00000000000
--- a/arch/um/include/umid.h
+++ /dev/null
@@ -1,22 +0,0 @@
-/*
- * Copyright (C) 2001 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#ifndef __UMID_H__
-#define __UMID_H__
-
-extern int umid_file_name(char *name, char *buf, int len);
-
-#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/user_util.h b/arch/um/include/user_util.h
index 06625fefef3..023575f6734 100644
--- a/arch/um/include/user_util.h
+++ b/arch/um/include/user_util.h
@@ -38,8 +38,6 @@ extern unsigned long long highmem;
 
 extern char host_info[];
 
-extern char saved_command_line[];
-
 extern unsigned long _stext, _etext, _sdata, _edata, __bss_start, _end;
 extern unsigned long _unprotected_end;
 extern unsigned long brk_start;
diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile
index 6fa63a2a89e..c5cf4a0827b 100644
--- a/arch/um/kernel/Makefile
+++ b/arch/um/kernel/Makefile
@@ -7,7 +7,7 @@ extra-y := vmlinux.lds
 clean-files :=
 
 obj-y = config.o exec.o exitcode.o init_task.o irq.o ksyms.o mem.o \
-	physmem.o process.o ptrace.o reboot.o resource.o sigio.o \
+	physmem.o process.o ptrace.o reboot.o sigio.o \
 	signal.o smp.o syscall.o sysrq.o time.o tlb.o trap.o uaccess.o \
 	um_arch.o umid.o
 
diff --git a/arch/um/kernel/exec.c b/arch/um/kernel/exec.c
index 8d56ec6cca7..121166400e2 100644
--- a/arch/um/kernel/exec.c
+++ b/arch/um/kernel/exec.c
@@ -39,9 +39,9 @@ static long execve1(char *file, char __user * __user *argv,
 		    char __user *__user *env)
 {
         long error;
+#ifdef CONFIG_TTY_LOG
 	struct tty_struct *tty;
 
-#ifdef CONFIG_TTY_LOG
 	mutex_lock(&tty_mutex);
 	tty = get_current_tty();
 	if (tty)
diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c
index 5c1e611f628..50a288bb875 100644
--- a/arch/um/kernel/irq.c
+++ b/arch/um/kernel/irq.c
@@ -79,7 +79,7 @@ skip:
 	return 0;
 }
 
-struct irq_fd *active_fds = NULL;
+static struct irq_fd *active_fds = NULL;
 static struct irq_fd **last_irq_ptr = &active_fds;
 
 extern void free_irqs(void);
@@ -124,8 +124,8 @@ int activate_fd(int irq, int fd, int type, void *dev_id)
 	if (err < 0)
 		goto out;
 
-	new_fd = um_kmalloc(sizeof(*new_fd));
 	err = -ENOMEM;
+	new_fd = kmalloc(sizeof(struct irq_fd), GFP_KERNEL);
 	if (new_fd == NULL)
 		goto out;
 
@@ -176,9 +176,8 @@ int activate_fd(int irq, int fd, int type, void *dev_id)
 		 */
 		spin_unlock_irqrestore(&irq_lock, flags);
 		kfree(tmp_pfd);
-		tmp_pfd = NULL;
 
-		tmp_pfd = um_kmalloc(n);
+		tmp_pfd = kmalloc(n, GFP_KERNEL);
 		if (tmp_pfd == NULL)
 			goto out_kfree;
 
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index c95855ba6ab..e85d65deea0 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -24,8 +24,9 @@
 #include "init.h"
 #include "kern_constants.h"
 
-/* Changed during early boot */
+/* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */
 unsigned long *empty_zero_page = NULL;
+/* allocated in paging_init and unchanged thereafter */
 unsigned long *empty_bad_page = NULL;
 pgd_t swapper_pg_dir[PTRS_PER_PGD];
 unsigned long long highmem;
@@ -65,8 +66,8 @@ void mem_init(void)
 {
 	max_low_pfn = (high_physmem - uml_physmem) >> PAGE_SHIFT;
 
-        /* clear the zero-page */
-        memset((void *) empty_zero_page, 0, PAGE_SIZE);
+	/* clear the zero-page */
+	memset((void *) empty_zero_page, 0, PAGE_SIZE);
 
 	/* Map in the area just after the brk now that kmalloc is about
 	 * to be turned on.
@@ -253,8 +254,10 @@ struct page *arch_validate(struct page *page, gfp_t mask, int order)
 	int i;
 
  again:
-	if(page == NULL) return(page);
-	if(PageHighMem(page)) return(page);
+	if(page == NULL)
+		return page;
+	if(PageHighMem(page))
+		return page;
 
 	addr = (unsigned long) page_address(page);
 	for(i = 0; i < (1 << order); i++){
@@ -263,13 +266,15 @@ struct page *arch_validate(struct page *page, gfp_t mask, int order)
 				     sizeof(zero),
 				     &current->thread.fault_addr,
 				     &current->thread.fault_catcher)){
-			if(!(mask & __GFP_WAIT)) return(NULL);
+			if(!(mask & __GFP_WAIT))
+				return NULL;
 			else break;
 		}
 		addr += PAGE_SIZE;
 	}
 
-	if(i == (1 << order)) return(page);
+	if(i == (1 << order))
+		return page;
 	page = alloc_pages(mask, order);
 	goto again;
 }
@@ -283,7 +288,6 @@ void free_initmem(void)
 }
 
 #ifdef CONFIG_BLK_DEV_INITRD
-
 void free_initrd_mem(unsigned long start, unsigned long end)
 {
 	if (start < end)
@@ -296,37 +300,36 @@ void free_initrd_mem(unsigned long start, unsigned long end)
 		totalram_pages++;
 	}
 }
-	
 #endif
 
 void show_mem(void)
 {
-        int pfn, total = 0, reserved = 0;
-        int shared = 0, cached = 0;
-        int highmem = 0;
+	int pfn, total = 0, reserved = 0;
+	int shared = 0, cached = 0;
+	int highmem = 0;
 	struct page *page;
 
-        printk("Mem-info:\n");
-        show_free_areas();
-        printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
-        pfn = max_mapnr;
-        while(pfn-- > 0) {
+	printk("Mem-info:\n");
+	show_free_areas();
+	printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
+	pfn = max_mapnr;
+	while(pfn-- > 0) {
 		page = pfn_to_page(pfn);
-                total++;
-                if(PageHighMem(page))
-                        highmem++;
-                if(PageReserved(page))
-                        reserved++;
-                else if(PageSwapCache(page))
-                        cached++;
-                else if(page_count(page))
-                        shared += page_count(page) - 1;
-        }
-        printk("%d pages of RAM\n", total);
-        printk("%d pages of HIGHMEM\n", highmem);
-        printk("%d reserved pages\n", reserved);
-        printk("%d pages shared\n", shared);
-        printk("%d pages swap cached\n", cached);
+		total++;
+		if(PageHighMem(page))
+			highmem++;
+		if(PageReserved(page))
+			reserved++;
+		else if(PageSwapCache(page))
+			cached++;
+		else if(page_count(page))
+			shared += page_count(page) - 1;
+	}
+	printk("%d pages of RAM\n", total);
+	printk("%d pages of HIGHMEM\n", highmem);
+	printk("%d reserved pages\n", reserved);
+	printk("%d pages shared\n", shared);
+	printk("%d pages swap cached\n", cached);
 }
 
 /*
@@ -362,28 +365,7 @@ pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
 struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
 {
 	struct page *pte;
-   
+
 	pte = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
 	return pte;
 }
-
-struct iomem_region *iomem_regions = NULL;
-int iomem_size = 0;
-
-extern int parse_iomem(char *str, int *add) __init;
-
-__uml_setup("iomem=", parse_iomem,
-"iomem=<name>,<file>\n"
-"    Configure <file> as an IO memory region named <name>.\n\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:
- */
diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c
index abafa64b872..638f3b5f609 100644
--- a/arch/um/kernel/physmem.c
+++ b/arch/um/kernel/physmem.c
@@ -40,7 +40,7 @@ static struct rb_node **find_rb(void *virt)
 	while(*n != NULL){
 		d = rb_entry(*n, struct phys_desc, rb);
 		if(d->virt == virt)
-			return(n);
+			return n;
 
 		if(d->virt > virt)
 			n = &(*n)->rb_left;
@@ -48,7 +48,7 @@ static struct rb_node **find_rb(void *virt)
 			n = &(*n)->rb_right;
 	}
 
-	return(n);
+	return n;
 }
 
 static struct phys_desc *find_phys_mapping(void *virt)
@@ -56,9 +56,9 @@ static struct phys_desc *find_phys_mapping(void *virt)
 	struct rb_node **n = find_rb(virt);
 
 	if(*n == NULL)
-		return(NULL);
+		return NULL;
 
-	return(rb_entry(*n, struct phys_desc, rb));
+	return rb_entry(*n, struct phys_desc, rb);
 }
 
 static void insert_phys_mapping(struct phys_desc *desc)
@@ -89,10 +89,10 @@ static struct desc_mapping *find_mapping(int fd)
 	list_for_each(ele, &descriptor_mappings){
 		desc = list_entry(ele, struct desc_mapping, list);
 		if(desc->fd == fd)
-			return(desc);
+			return desc;
 	}
 
-	return(NULL);
+	return NULL;
 }
 
 static struct desc_mapping *descriptor_mapping(int fd)
@@ -101,11 +101,11 @@ static struct desc_mapping *descriptor_mapping(int fd)
 
 	desc = find_mapping(fd);
 	if(desc != NULL)
-		return(desc);
+		return desc;
 
 	desc = kmalloc(sizeof(*desc), GFP_ATOMIC);
 	if(desc == NULL)
-		return(NULL);
+		return NULL;
 
 	*desc = ((struct desc_mapping)
 		{ .fd =		fd,
@@ -113,7 +113,7 @@ static struct desc_mapping *descriptor_mapping(int fd)
 		  .pages =	LIST_HEAD_INIT(desc->pages) });
 	list_add(&desc->list, &descriptor_mappings);
 
-	return(desc);
+	return desc;
 }
 
 int physmem_subst_mapping(void *virt, int fd, __u64 offset, int w)
@@ -125,11 +125,11 @@ int physmem_subst_mapping(void *virt, int fd, __u64 offset, int w)
 
 	fd_maps = descriptor_mapping(fd);
 	if(fd_maps == NULL)
-		return(-ENOMEM);
+		return -ENOMEM;
 
 	phys = __pa(virt);
 	desc = find_phys_mapping(virt);
-  	if(desc != NULL)
+	if(desc != NULL)
 		panic("Address 0x%p is already substituted\n", virt);
 
 	err = -ENOMEM;
@@ -155,7 +155,7 @@ int physmem_subst_mapping(void *virt, int fd, __u64 offset, int w)
 	rb_erase(&desc->rb, &phys_mappings);
 	kfree(desc);
  out:
-	return(err);
+	return err;
 }
 
 static int physmem_fd = -1;
@@ -182,10 +182,10 @@ int physmem_remove_mapping(void *virt)
 	virt = (void *) ((unsigned long) virt & PAGE_MASK);
 	desc = find_phys_mapping(virt);
 	if(desc == NULL)
-		return(0);
+		return 0;
 
 	remove_mapping(desc);
-	return(1);
+	return 1;
 }
 
 void physmem_forget_descriptor(int fd)
@@ -239,9 +239,9 @@ void arch_free_page(struct page *page, int order)
 
 int is_remapped(void *virt)
 {
-  	struct phys_desc *desc = find_phys_mapping(virt);
+ 	struct phys_desc *desc = find_phys_mapping(virt);
 
-	return(desc != NULL);
+	return desc != NULL;
 }
 
 /* Changed during early boot */
@@ -276,7 +276,7 @@ int init_maps(unsigned long physmem, unsigned long iomem, unsigned long highmem)
 	else map = alloc_bootmem_low_pages(total_len);
 
 	if(map == NULL)
-		return(-ENOMEM);
+		return -ENOMEM;
 
 	for(i = 0; i < total_pages; i++){
 		p = &map[i];
@@ -286,7 +286,7 @@ int init_maps(unsigned long physmem, unsigned long iomem, unsigned long highmem)
 	}
 
 	max_mapnr = total_pages;
-	return(0);
+	return 0;
 }
 
 /* Changed during early boot */
@@ -296,7 +296,7 @@ unsigned long get_kmem_end(void)
 {
 	if(kmem_top == 0)
 		kmem_top = CHOOSE_MODE(kmem_end_tt, kmem_end_skas);
-	return(kmem_top);
+	return kmem_top;
 }
 
 void map_memory(unsigned long virt, unsigned long phys, unsigned long len,
@@ -379,7 +379,7 @@ int phys_mapping(unsigned long phys, __u64 *offset_out)
 		*offset_out = phys - iomem_size;
 	}
 
-	return(fd);
+	return fd;
 }
 
 static int __init uml_mem_setup(char *line, int *add)
@@ -398,6 +398,23 @@ __uml_setup("mem=", uml_mem_setup,
 "	Example: mem=64M\n\n"
 );
 
+extern int __init parse_iomem(char *str, int *add);
+
+__uml_setup("iomem=", parse_iomem,
+"iomem=<name>,<file>\n"
+"    Configure <file> as an IO memory region named <name>.\n\n"
+);
+
+/*
+ * This list is constructed in parse_iomem and addresses filled in in
+ * setup_iomem, both of which run during early boot.  Afterwards, it's
+ * unchanged.
+ */
+struct iomem_region *iomem_regions = NULL;
+
+/* Initialized in parse_iomem */
+int iomem_size = 0;
+
 unsigned long find_iomem(char *driver, unsigned long *len_out)
 {
 	struct iomem_region *region = iomem_regions;
@@ -405,13 +422,13 @@ unsigned long find_iomem(char *driver, unsigned long *len_out)
 	while(region != NULL){
 		if(!strcmp(region->driver, driver)){
 			*len_out = region->size;
-			return(region->virt);
+			return region->virt;
 		}
 
 		region = region->next;
 	}
 
-	return(0);
+	return 0;
 }
 
 int setup_iomem(void)
@@ -435,18 +452,7 @@ int setup_iomem(void)
 		region = region->next;
 	}
 
-	return(0);
+	return 0;
 }
 
 __initcall(setup_iomem);
-
-/*
- * 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/kernel/ptrace.c b/arch/um/kernel/ptrace.c
index 9a77fb3c269..627742d8943 100644
--- a/arch/um/kernel/ptrace.c
+++ b/arch/um/kernel/ptrace.c
@@ -18,6 +18,7 @@
 #include "kern_util.h"
 #include "skas_ptrace.h"
 #include "sysdep/ptrace.h"
+#include "os.h"
 
 static inline void set_singlestepping(struct task_struct *child, int on)
 {
@@ -241,6 +242,12 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 		break;
 	}
 #endif
+#ifdef PTRACE_ARCH_PRCTL
+        case PTRACE_ARCH_PRCTL:
+                /* XXX Calls ptrace on the host - needs some SMP thinking */
+                ret = arch_prctl_skas(child, data, (void *) addr);
+                break;
+#endif
 	default:
 		ret = ptrace_request(child, request, addr, data);
 		break;
diff --git a/arch/um/kernel/resource.c b/arch/um/kernel/resource.c
deleted file mode 100644
index 32188e12e8a..00000000000
--- a/arch/um/kernel/resource.c
+++ /dev/null
@@ -1,23 +0,0 @@
-/* 
- * Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#include "linux/pci.h"
-
-unsigned long resource_fixup(struct pci_dev * dev, struct resource * res,
-			     unsigned long start, unsigned long size)
-{
-	return start;
-}
-
-/*
- * 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/kernel/sigio.c b/arch/um/kernel/sigio.c
index 2b0ab438301..89f9866a135 100644
--- a/arch/um/kernel/sigio.c
+++ b/arch/um/kernel/sigio.c
@@ -23,7 +23,7 @@ static irqreturn_t sigio_interrupt(int irq, void *data)
 
 	os_read_file(sigio_irq_fd, &c, sizeof(c));
 	reactivate_fd(sigio_irq_fd, SIGIO_WRITE_IRQ);
-	return(IRQ_HANDLED);
+	return IRQ_HANDLED;
 }
 
 int write_sigio_irq(int fd)
@@ -36,12 +36,13 @@ int write_sigio_irq(int fd)
 	if(err){
 		printk("write_sigio_irq : um_request_irq failed, err = %d\n",
 		       err);
-		return(-1);
+		return -1;
 	}
 	sigio_irq_fd = fd;
-	return(0);
+	return 0;
 }
 
+/* These are called from os-Linux/sigio.c to protect its pollfds arrays. */
 static DEFINE_SPINLOCK(sigio_spinlock);
 
 void sigio_lock(void)
diff --git a/arch/um/kernel/skas/mem.c b/arch/um/kernel/skas/mem.c
index 0d2cce62113..7c18dfcd7d8 100644
--- a/arch/um/kernel/skas/mem.c
+++ b/arch/um/kernel/skas/mem.c
@@ -14,13 +14,9 @@ unsigned long set_task_sizes_skas(unsigned long *task_size_out)
 	unsigned long host_task_size = ROUND_4M((unsigned long)
 						&host_task_size);
 
-#ifdef CONFIG_HOST_TASK_SIZE
-	*host_size_out = ROUND_4M(CONFIG_HOST_TASK_SIZE);
-	*task_size_out = CONFIG_HOST_TASK_SIZE;
-#else
 	if (!skas_needs_stub)
 		*task_size_out = host_task_size;
 	else *task_size_out = CONFIG_STUB_START & PGDIR_MASK;
-#endif
+
 	return host_task_size;
 }
diff --git a/arch/um/kernel/syscall.c b/arch/um/kernel/syscall.c
index f5ed8624648..2828c528322 100644
--- a/arch/um/kernel/syscall.c
+++ b/arch/um/kernel/syscall.c
@@ -149,22 +149,6 @@ long sys_olduname(struct oldold_utsname __user * name)
 	return error;
 }
 
-DEFINE_SPINLOCK(syscall_lock);
-
-static int syscall_index = 0;
-
-int next_syscall_index(int limit)
-{
-	int ret;
-
-	spin_lock(&syscall_lock);
-	ret = syscall_index;
-	if(++syscall_index == limit)
-		syscall_index = 0;
-	spin_unlock(&syscall_lock);
-	return(ret);
-}
-
 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
 {
 	mm_segment_t fs;
diff --git a/arch/um/kernel/sysrq.c b/arch/um/kernel/sysrq.c
index 239c98054de..f9e02b31a97 100644
--- a/arch/um/kernel/sysrq.c
+++ b/arch/um/kernel/sysrq.c
@@ -50,7 +50,7 @@ void dump_stack(void)
 EXPORT_SYMBOL(dump_stack);
 
 /*Stolen from arch/i386/kernel/traps.c */
-static int kstack_depth_to_print = 24;
+static const int kstack_depth_to_print = 24;
 
 /* This recently started being used in arch-independent code too, as in
  * kernel/sched.c.*/
diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c
index 2e354b3ca06..b1f8b075241 100644
--- a/arch/um/kernel/time.c
+++ b/arch/um/kernel/time.c
@@ -35,31 +35,31 @@ unsigned long long sched_clock(void)
 	return (unsigned long long)jiffies_64 * (1000000000 / HZ);
 }
 
-static unsigned long long prev_nsecs;
+static unsigned long long prev_nsecs[NR_CPUS];
 #ifdef CONFIG_UML_REAL_TIME_CLOCK
-static long long delta;   		/* Deviation per interval */
+static long long delta[NR_CPUS];		/* Deviation per interval */
 #endif
 
 void timer_irq(union uml_pt_regs *regs)
 {
 	unsigned long long ticks = 0;
-
 #ifdef CONFIG_UML_REAL_TIME_CLOCK
-	if(prev_nsecs){
+	int c = cpu();
+	if(prev_nsecs[c]){
 		/* We've had 1 tick */
 		unsigned long long nsecs = os_nsecs();
 
-		delta += nsecs - prev_nsecs;
-		prev_nsecs = nsecs;
+		delta[c] += nsecs - prev_nsecs[c];
+		prev_nsecs[c] = nsecs;
 
 		/* Protect against the host clock being set backwards */
-		if(delta < 0)
-			delta = 0;
+		if(delta[c] < 0)
+			delta[c] = 0;
 
-		ticks += (delta * HZ) / BILLION;
-		delta -= (ticks * BILLION) / HZ;
+		ticks += (delta[c] * HZ) / BILLION;
+		delta[c] -= (ticks * BILLION) / HZ;
 	}
-	else prev_nsecs = os_nsecs();
+	else prev_nsecs[c] = os_nsecs();
 #else
 	ticks = 1;
 #endif
@@ -69,8 +69,8 @@ void timer_irq(union uml_pt_regs *regs)
 	}
 }
 
+/* Protects local_offset */
 static DEFINE_SPINLOCK(timer_spinlock);
-
 static unsigned long long local_offset = 0;
 
 static inline unsigned long long get_time(void)
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index b5f124a2f6a..26f15c45857 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -128,7 +128,18 @@ out_of_memory:
 	goto out;
 }
 
-void segv_handler(int sig, union uml_pt_regs *regs)
+static void bad_segv(struct faultinfo fi, unsigned long ip)
+{
+	struct siginfo si;
+
+	si.si_signo = SIGSEGV;
+	si.si_code = SEGV_ACCERR;
+	si.si_addr = (void __user *) FAULT_ADDRESS(fi);
+	current->thread.arch.faultinfo = fi;
+	force_sig_info(SIGSEGV, &si, current);
+}
+
+static void segv_handler(int sig, union uml_pt_regs *regs)
 {
 	struct faultinfo * fi = UPT_FAULTINFO(regs);
 
@@ -205,17 +216,6 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void *sc)
 	return(0);
 }
 
-void bad_segv(struct faultinfo fi, unsigned long ip)
-{
-	struct siginfo si;
-
-	si.si_signo = SIGSEGV;
-	si.si_code = SEGV_ACCERR;
-	si.si_addr = (void __user *) FAULT_ADDRESS(fi);
-	current->thread.arch.faultinfo = fi;
-	force_sig_info(SIGSEGV, &si, current);
-}
-
 void relay_signal(int sig, union uml_pt_regs *regs)
 {
 	if(arch_handle_signal(sig, regs))
@@ -232,14 +232,14 @@ void relay_signal(int sig, union uml_pt_regs *regs)
 	force_sig(sig, current);
 }
 
-void bus_handler(int sig, union uml_pt_regs *regs)
+static void bus_handler(int sig, union uml_pt_regs *regs)
 {
 	if(current->thread.fault_catcher != NULL)
 		do_longjmp(current->thread.fault_catcher, 1);
 	else relay_signal(sig, regs);
 }
 
-void winch(int sig, union uml_pt_regs *regs)
+static void winch(int sig, union uml_pt_regs *regs)
 {
 	do_IRQ(WINCH_IRQ, regs);
 }
diff --git a/arch/um/kernel/tt/gdb.c b/arch/um/kernel/tt/gdb.c
index 786e4edd86c..8eba8f7dca6 100644
--- a/arch/um/kernel/tt/gdb.c
+++ b/arch/um/kernel/tt/gdb.c
@@ -139,7 +139,7 @@ static void config_gdb_cb(void *arg)
 	init_proxy(debugger_pid, 0, 0);
 }
 
-int gdb_config(char *str)
+int gdb_config(char *str, char **error_out)
 {
 	struct gdb_data data;
 
@@ -154,7 +154,7 @@ void remove_gdb_cb(void *unused)
 	exit_debugger_cb(NULL);
 }
 
-int gdb_remove(int unused)
+int gdb_remove(int unused, char **error_out)
 {
 	initial_thread_cb(remove_gdb_cb, NULL);
         return 0;
diff --git a/arch/um/kernel/tt/gdb_kern.c b/arch/um/kernel/tt/gdb_kern.c
index 68e1bf63cd0..03b06bc0077 100644
--- a/arch/um/kernel/tt/gdb_kern.c
+++ b/arch/um/kernel/tt/gdb_kern.c
@@ -8,10 +8,11 @@
 
 #ifdef CONFIG_MCONSOLE
 
-extern int gdb_config(char *str);
-extern int gdb_remove(int n);
+extern int gdb_config(char *str, char **error_out);
+extern int gdb_remove(int n, char **error_out);
 
 static struct mc_device gdb_mc = {
+	.list		= INIT_LIST_HEAD(gdb_mc.list),
 	.name		= "gdb",
 	.config		= gdb_config,
 	.remove		= gdb_remove,
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 66f43c90682..89c6dba731f 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -30,7 +30,6 @@
 #include "kern.h"
 #include "mem_user.h"
 #include "mem.h"
-#include "umid.h"
 #include "initrd.h"
 #include "init.h"
 #include "os.h"
@@ -44,9 +43,9 @@
 #define DEFAULT_COMMAND_LINE "root=98:0"
 
 /* Changed in linux_main and setup_arch, which run before SMP is started */
-static char command_line[COMMAND_LINE_SIZE] = { 0 };
+static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 };
 
-static void add_arg(char *arg)
+static void __init add_arg(char *arg)
 {
 	if (strlen(command_line) + strlen(arg) + 1 > COMMAND_LINE_SIZE) {
 		printf("add_arg: Too many command line arguments!\n");
@@ -331,7 +330,7 @@ EXPORT_SYMBOL(end_iomem);
 
 extern char __binary_start;
 
-int linux_main(int argc, char **argv)
+int __init linux_main(int argc, char **argv)
 {
 	unsigned long avail, diff;
 	unsigned long virtmem_size, max_physmem;
@@ -482,7 +481,7 @@ void __init setup_arch(char **cmdline_p)
 	atomic_notifier_chain_register(&panic_notifier_list,
 			&panic_exit_notifier);
 	paging_init();
-        strlcpy(saved_command_line, command_line, COMMAND_LINE_SIZE);
+	strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
  	*cmdline_p = command_line;
 	setup_hostinfo();
 }
diff --git a/arch/um/kernel/umid.c b/arch/um/kernel/umid.c
index 4eaee823bfd..039e16efcd5 100644
--- a/arch/um/kernel/umid.c
+++ b/arch/um/kernel/umid.c
@@ -16,8 +16,10 @@ static int __init set_umid_arg(char *name, int *add)
 {
 	int err;
 
-	if(umid_inited)
+	if(umid_inited){
+		printf("umid already set\n");
 		return 0;
+	}
 
 	*add = 0;
 	err = set_umid(name);
diff --git a/arch/um/os-Linux/aio.c b/arch/um/os-Linux/aio.c
index f897140cc4a..6ff12743a0b 100644
--- a/arch/um/os-Linux/aio.c
+++ b/arch/um/os-Linux/aio.c
@@ -24,9 +24,6 @@ struct aio_thread_req {
 	struct aio_context *aio;
 };
 
-static int aio_req_fd_r = -1;
-static int aio_req_fd_w = -1;
-
 #if defined(HAVE_AIO_ABI)
 #include <linux/aio_abi.h>
 
@@ -111,6 +108,7 @@ static int do_aio(aio_context_t ctx, enum aio_type type, int fd, char *buf,
 	return err;
 }
 
+/* Initialized in an initcall and unchanged thereafter */
 static aio_context_t ctx = 0;
 
 static int aio_thread(void *arg)
@@ -137,7 +135,7 @@ static int aio_thread(void *arg)
 			err = os_write_file(reply_fd, &reply, sizeof(reply));
 			if(err != sizeof(reply))
 				printk("aio_thread - write failed, fd = %d, "
-				       "err = %d\n", aio_req_fd_r, -err);
+				       "err = %d\n", reply_fd, -err);
 		}
 	}
 	return 0;
@@ -182,6 +180,11 @@ out:
 	return err;
 }
 
+/* These are initialized in initcalls and not changed */
+static int aio_req_fd_r = -1;
+static int aio_req_fd_w = -1;
+static int aio_pid = -1;
+
 static int not_aio_thread(void *arg)
 {
 	struct aio_thread_req req;
@@ -208,14 +211,12 @@ static int not_aio_thread(void *arg)
 		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);
+			       "err = %d\n", req.aio->reply_fd, -err);
 	}
 
 	return 0;
 }
 
-static int aio_pid = -1;
-
 static int init_aio_24(void)
 {
 	unsigned long stack;
@@ -308,6 +309,7 @@ static int submit_aio_26(enum aio_type type, int io_fd, char *buf, int len,
 }
 #endif
 
+/* Initialized in an initcall and unchanged thereafter */
 static int aio_24 = DEFAULT_24_AIO;
 
 static int __init set_aio_24(char *name, int *add)
diff --git a/arch/um/os-Linux/elf_aux.c b/arch/um/os-Linux/elf_aux.c
index 5a99dd3fbed..3a8d7e3aae0 100644
--- a/arch/um/os-Linux/elf_aux.c
+++ b/arch/um/os-Linux/elf_aux.c
@@ -21,12 +21,11 @@ typedef Elf32_auxv_t elf_auxv_t;
 typedef Elf64_auxv_t elf_auxv_t;
 #endif
 
+/* These are initialized very early in boot and never changed */
 char * elf_aux_platform;
 long elf_aux_hwcap;
-
 unsigned long vsyscall_ehdr;
 unsigned long vsyscall_end;
-
 unsigned long __kernel_vsyscall;
 
 __init void scan_elf_aux( char **envp)
diff --git a/arch/um/os-Linux/file.c b/arch/um/os-Linux/file.c
index 189fa677085..371b4335f46 100644
--- a/arch/um/os-Linux/file.c
+++ b/arch/um/os-Linux/file.c
@@ -162,25 +162,6 @@ int os_set_owner(int fd, int pid)
 	return 0;
 }
 
-/* FIXME? moved wholesale from sigio_user.c to get fcntls out of that file */
-int os_sigio_async(int master, int slave)
-{
-	int flags;
-
-	flags = fcntl(master, F_GETFL);
-	if(flags < 0)
-		return -errno;
-
-	if((fcntl(master, F_SETFL, flags | O_NONBLOCK | O_ASYNC) < 0) ||
-	   (fcntl(master, F_SETOWN, os_getpid()) < 0))
-		return -errno;
-
-	if((fcntl(slave, F_SETFL, flags | O_NONBLOCK) < 0))
-		return -errno;
-
-	return(0);
-}
-
 int os_mode_fd(int fd, int mode)
 {
 	int err;
diff --git a/arch/um/os-Linux/irq.c b/arch/um/os-Linux/irq.c
index d46b818c131..d1b61d474e0 100644
--- a/arch/um/os-Linux/irq.c
+++ b/arch/um/os-Linux/irq.c
@@ -20,6 +20,10 @@
 #include "os.h"
 #include "um_malloc.h"
 
+/*
+ * Locked by irq_lock in arch/um/kernel/irq.c.  Changed by os_create_pollfd
+ * and os_free_irq_by_cb, which are called under irq_lock.
+ */
 static struct pollfd *pollfds = NULL;
 static int pollfds_num = 0;
 static int pollfds_size = 0;
@@ -58,7 +62,7 @@ int os_create_pollfd(int fd, int events, void *tmp_pfd, int size_tmpfds)
 	if (pollfds_num == pollfds_size) {
 		if (size_tmpfds <= pollfds_size * sizeof(pollfds[0])) {
 			/* return min size needed for new pollfds area */
-			return((pollfds_size + 1) * sizeof(pollfds[0]));
+			return (pollfds_size + 1) * sizeof(pollfds[0]);
 		}
 
 		if (pollfds != NULL) {
diff --git a/arch/um/os-Linux/mem.c b/arch/um/os-Linux/mem.c
index 4203681e508..f1ea169db85 100644
--- a/arch/um/os-Linux/mem.c
+++ b/arch/um/os-Linux/mem.c
@@ -20,7 +20,13 @@
 
 #include <sys/param.h>
 
+/* Modified by which_tmpdir, which is called during early boot */
 static char *default_tmpdir = "/tmp";
+
+/*
+ *  Modified when creating the physical memory file and when checking
+ * the tmp filesystem for usability, both happening during early boot.
+ */
 static char *tempdir = NULL;
 
 static void __init find_tempdir(void)
@@ -29,7 +35,8 @@ static void __init find_tempdir(void)
 	int i;
 	char *dir = NULL;
 
-	if(tempdir != NULL) return;	/* We've already been called */
+	if(tempdir != NULL) /* We've already been called */
+		return;
 	for(i = 0; dirs[i]; i++){
 		dir = getenv(dirs[i]);
 		if((dir != NULL) && (*dir != '\0'))
@@ -83,6 +90,7 @@ static int next(int fd, char *buf, int size, char c)
 	return 1;
 }
 
+/* which_tmpdir is called only during early boot */
 static int checked_tmpdir = 0;
 
 /* Look for a tmpfs mounted at /dev/shm.  I couldn't find a cleaner
@@ -186,7 +194,7 @@ int make_tempfile(const char *template, char **out_tempname, int do_unlink)
 	} else {
 		free(tempname);
 	}
-	return(fd);
+	return fd;
 out:
 	free(tempname);
 	return -1;
@@ -231,7 +239,7 @@ int create_tmp_file(unsigned long long len)
 		exit(1);
 	}
 
-	return(fd);
+	return fd;
 }
 
 int create_mem_file(unsigned long long len)
@@ -245,7 +253,7 @@ int create_mem_file(unsigned long long len)
 		errno = -err;
 		perror("exec_close");
 	}
-	return(fd);
+	return fd;
 }
 
 
diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c
index 7fe92680c7d..5178eba9afa 100644
--- a/arch/um/os-Linux/start_up.c
+++ b/arch/um/os-Linux/start_up.c
@@ -54,7 +54,7 @@ static int ptrace_child(void *arg)
 		perror("ptrace");
 		os_kill_process(pid, 0);
 	}
-	os_stop_process(pid);
+	kill(pid, SIGSTOP);
 
 	/*This syscall will be intercepted by the parent. Don't call more than
 	 * once, please.*/
@@ -73,6 +73,34 @@ static int ptrace_child(void *arg)
 	_exit(ret);
 }
 
+static void fatal_perror(char *str)
+{
+	perror(str);
+	exit(1);
+}
+
+static void fatal(char *fmt, ...)
+{
+	va_list list;
+
+	va_start(list, fmt);
+	vprintf(fmt, list);
+	va_end(list);
+	fflush(stdout);
+
+	exit(1);
+}
+
+static void non_fatal(char *fmt, ...)
+{
+	va_list list;
+
+	va_start(list, fmt);
+	vprintf(fmt, list);
+	va_end(list);
+	fflush(stdout);
+}
+
 static int start_ptraced_child(void **stack_out)
 {
 	void *stack;
@@ -82,20 +110,20 @@ static int start_ptraced_child(void **stack_out)
 	stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
 		     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 	if(stack == MAP_FAILED)
-		panic("check_ptrace : mmap failed, errno = %d", errno);
+		fatal_perror("check_ptrace : mmap failed");
 	sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
 	pid = clone(ptrace_child, (void *) sp, SIGCHLD, NULL);
 	if(pid < 0)
-		panic("start_ptraced_child : clone failed, errno = %d", errno);
+		fatal_perror("start_ptraced_child : clone failed");
 	CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 	if(n < 0)
-		panic("check_ptrace : clone failed, errno = %d", errno);
+		fatal_perror("check_ptrace : clone failed");
 	if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
-		panic("check_ptrace : expected SIGSTOP, got status = %d",
+		fatal("check_ptrace : expected SIGSTOP, got status = %d",
 		      status);
 
 	*stack_out = stack;
-	return(pid);
+	return pid;
 }
 
 /* When testing for SYSEMU support, if it is one of the broken versions, we
@@ -105,34 +133,34 @@ static int start_ptraced_child(void **stack_out)
  * must work anyway!
  */
 static int stop_ptraced_child(int pid, void *stack, int exitcode,
-			      int mustpanic)
+			      int mustexit)
 {
 	int status, n, ret = 0;
 
 	if(ptrace(PTRACE_CONT, pid, 0, 0) < 0)
-		panic("check_ptrace : ptrace failed, errno = %d", errno);
+		fatal_perror("stop_ptraced_child : ptrace failed");
 	CATCH_EINTR(n = waitpid(pid, &status, 0));
 	if(!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) {
 		int exit_with = WEXITSTATUS(status);
 		if (exit_with == 2)
-			printf("check_ptrace : child exited with status 2. "
-			       "Serious trouble happening! Try updating your "
-			       "host skas patch!\nDisabling SYSEMU support.");
-		printf("check_ptrace : child exited with exitcode %d, while "
-		      "expecting %d; status 0x%x", exit_with,
-		      exitcode, status);
-		if (mustpanic)
-			panic("\n");
-		else
-			printf("\n");
+			non_fatal("check_ptrace : child exited with status 2. "
+				  "Serious trouble happening! Try updating "
+				  "your host skas patch!\nDisabling SYSEMU "
+				  "support.");
+		non_fatal("check_ptrace : child exited with exitcode %d, while "
+			  "expecting %d; status 0x%x\n", exit_with,
+			  exitcode, status);
+		if (mustexit)
+			exit(1);
 		ret = -1;
 	}
 
 	if(munmap(stack, PAGE_SIZE) < 0)
-		panic("check_ptrace : munmap failed, errno = %d", errno);
+		fatal_perror("check_ptrace : munmap failed");
 	return ret;
 }
 
+/* Changed only during early boot */
 int ptrace_faultinfo = 1;
 int ptrace_ldt = 1;
 int proc_mm = 1;
@@ -160,6 +188,7 @@ __uml_setup("mode=skas0", mode_skas0_cmd_param,
 		"    specify mode=tt. Note that this was recently added - on \n"
 		"    older kernels you must use simply \"skas0\".\n\n");
 
+/* Changed only during early boot */
 static int force_sysemu_disabled = 0;
 
 static int __init nosysemu_cmd_param(char *str, int* add)
@@ -180,9 +209,9 @@ __uml_setup("nosysemu", nosysemu_cmd_param,
 static void __init check_sysemu(void)
 {
 	void *stack;
- 	int pid, n, status, count=0;
+	int pid, n, status, count=0;
 
-	printf("Checking syscall emulation patch for ptrace...");
+	non_fatal("Checking syscall emulation patch for ptrace...");
 	sysemu_supported = 0;
 	pid = start_ptraced_child(&stack);
 
@@ -191,31 +220,30 @@ static void __init check_sysemu(void)
 
 	CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 	if (n < 0)
-		panic("check_sysemu : wait failed, errno = %d", errno);
+		fatal_perror("check_sysemu : wait failed");
 	if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
-		panic("check_sysemu : expected SIGTRAP, "
-		      "got status = %d", status);
+		fatal("check_sysemu : expected SIGTRAP, got status = %d",
+		      status);
 
 	n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET,
 		   os_getpid());
 	if(n < 0)
-		panic("check_sysemu : failed to modify system "
-		      "call return, errno = %d", errno);
+		fatal_perror("check_sysemu : failed to modify system call "
+			     "return");
 
 	if (stop_ptraced_child(pid, stack, 0, 0) < 0)
 		goto fail_stopped;
 
 	sysemu_supported = 1;
-	printf("OK\n");
+	non_fatal("OK\n");
 	set_using_sysemu(!force_sysemu_disabled);
 
-	printf("Checking advanced syscall emulation patch for ptrace...");
+	non_fatal("Checking advanced syscall emulation patch for ptrace...");
 	pid = start_ptraced_child(&stack);
 
-	if(ptrace(PTRACE_OLDSETOPTIONS, pid, 0,
-		  (void *) PTRACE_O_TRACESYSGOOD) < 0)
-		panic("check_ptrace: PTRACE_OLDSETOPTIONS failed, errno = %d",
-		      errno);
+	if((ptrace(PTRACE_OLDSETOPTIONS, pid, 0,
+		   (void *) PTRACE_O_TRACESYSGOOD) < 0))
+		fatal_perror("check_ptrace: PTRACE_OLDSETOPTIONS failed");
 
 	while(1){
 		count++;
@@ -223,29 +251,30 @@ static void __init check_sysemu(void)
 			goto fail;
 		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 		if(n < 0)
-			panic("check_ptrace : wait failed, errno = %d", errno);
+			fatal_perror("check_ptrace : wait failed");
+
 		if(WIFSTOPPED(status) && (WSTOPSIG(status) == (SIGTRAP|0x80))){
 			if (!count)
-				panic("check_ptrace : SYSEMU_SINGLESTEP "
+				fatal("check_ptrace : SYSEMU_SINGLESTEP "
 				      "doesn't singlestep");
 			n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET,
 				   os_getpid());
 			if(n < 0)
-				panic("check_sysemu : failed to modify system "
-				      "call return, errno = %d", errno);
+				fatal_perror("check_sysemu : failed to modify "
+					     "system call return");
 			break;
 		}
 		else if(WIFSTOPPED(status) && (WSTOPSIG(status) == SIGTRAP))
 			count++;
 		else
-			panic("check_ptrace : expected SIGTRAP or "
-			      "(SIGTRAP|0x80), got status = %d", status);
+			fatal("check_ptrace : expected SIGTRAP or "
+			      "(SIGTRAP | 0x80), got status = %d", status);
 	}
 	if (stop_ptraced_child(pid, stack, 0, 0) < 0)
 		goto fail_stopped;
 
 	sysemu_supported = 2;
-	printf("OK\n");
+	non_fatal("OK\n");
 
 	if ( !force_sysemu_disabled )
 		set_using_sysemu(sysemu_supported);
@@ -254,7 +283,7 @@ static void __init check_sysemu(void)
 fail:
 	stop_ptraced_child(pid, stack, 1, 0);
 fail_stopped:
-	printf("missing\n");
+	non_fatal("missing\n");
 }
 
 static void __init check_ptrace(void)
@@ -262,22 +291,25 @@ static void __init check_ptrace(void)
 	void *stack;
 	int pid, syscall, n, status;
 
-	printf("Checking that ptrace can change system call numbers...");
+	non_fatal("Checking that ptrace can change system call numbers...");
 	pid = start_ptraced_child(&stack);
 
-	if(ptrace(PTRACE_OLDSETOPTIONS, pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0)
-		panic("check_ptrace: PTRACE_OLDSETOPTIONS failed, errno = %d", errno);
+	if((ptrace(PTRACE_OLDSETOPTIONS, pid, 0,
+		   (void *) PTRACE_O_TRACESYSGOOD) < 0))
+		fatal_perror("check_ptrace: PTRACE_OLDSETOPTIONS failed");
 
 	while(1){
 		if(ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0)
-			panic("check_ptrace : ptrace failed, errno = %d",
-			      errno);
+			fatal_perror("check_ptrace : ptrace failed");
+
 		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 		if(n < 0)
-			panic("check_ptrace : wait failed, errno = %d", errno);
-		if(!WIFSTOPPED(status) || (WSTOPSIG(status) != (SIGTRAP|0x80)))
-			panic("check_ptrace : expected (SIGTRAP|0x80), "
-			      "got status = %d", status);
+			fatal_perror("check_ptrace : wait failed");
+
+		if(!WIFSTOPPED(status) ||
+		   (WSTOPSIG(status) != (SIGTRAP | 0x80)))
+			fatal("check_ptrace : expected (SIGTRAP|0x80), "
+			       "got status = %d", status);
 
 		syscall = ptrace(PTRACE_PEEKUSR, pid, PT_SYSCALL_NR_OFFSET,
 				 0);
@@ -285,13 +317,13 @@ static void __init check_ptrace(void)
 			n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET,
 				   __NR_getppid);
 			if(n < 0)
-				panic("check_ptrace : failed to modify system "
-				      "call, errno = %d", errno);
+				fatal_perror("check_ptrace : failed to modify "
+					     "system call");
 			break;
 		}
 	}
 	stop_ptraced_child(pid, stack, 0, 1);
-	printf("OK\n");
+	non_fatal("OK\n");
 	check_sysemu();
 }
 
@@ -350,22 +382,22 @@ static inline void check_skas3_ptrace_faultinfo(void)
 	void *stack;
 	int pid, n;
 
-	printf("  - PTRACE_FAULTINFO...");
+	non_fatal("  - PTRACE_FAULTINFO...");
 	pid = start_ptraced_child(&stack);
 
 	n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi);
 	if (n < 0) {
 		ptrace_faultinfo = 0;
 		if(errno == EIO)
-			printf("not found\n");
+			non_fatal("not found\n");
 		else
 			perror("not found");
 	}
 	else {
 		if (!ptrace_faultinfo)
-			printf("found but disabled on command line\n");
+			non_fatal("found but disabled on command line\n");
 		else
-			printf("found\n");
+			non_fatal("found\n");
 	}
 
 	init_registers(pid);
@@ -383,13 +415,13 @@ static inline void check_skas3_ptrace_ldt(void)
 		.ptr = ldtbuf,
 		.bytecount = sizeof(ldtbuf)};
 
-	printf("  - PTRACE_LDT...");
+	non_fatal("  - PTRACE_LDT...");
 	pid = start_ptraced_child(&stack);
 
 	n = ptrace(PTRACE_LDT, pid, 0, (unsigned long) &ldt_op);
 	if (n < 0) {
 		if(errno == EIO)
-			printf("not found\n");
+			non_fatal("not found\n");
 		else {
 			perror("not found");
 		}
@@ -397,9 +429,9 @@ static inline void check_skas3_ptrace_ldt(void)
 	}
 	else {
 		if(ptrace_ldt)
-			printf("found\n");
+			non_fatal("found\n");
 		else
-			printf("found, but use is disabled\n");
+			non_fatal("found, but use is disabled\n");
 	}
 
 	stop_ptraced_child(pid, stack, 1, 1);
@@ -414,22 +446,22 @@ static inline void check_skas3_ptrace_ldt(void)
 
 static inline void check_skas3_proc_mm(void)
 {
-	printf("  - /proc/mm...");
-	if (os_access("/proc/mm", OS_ACC_W_OK) < 0) {
- 		proc_mm = 0;
-		printf("not found\n");
+	non_fatal("  - /proc/mm...");
+	if (access("/proc/mm", W_OK) < 0) {
+		proc_mm = 0;
+		perror("not found");
 	}
 	else {
 		if (!proc_mm)
-			printf("found but disabled on command line\n");
+			non_fatal("found but disabled on command line\n");
 		else
-			printf("found\n");
+			non_fatal("found\n");
 	}
 }
 
 int can_do_skas(void)
 {
-	printf("Checking for the skas3 patch in the host:\n");
+	non_fatal("Checking for the skas3 patch in the host:\n");
 
 	check_skas3_proc_mm();
 	check_skas3_ptrace_faultinfo();
@@ -443,16 +475,16 @@ int can_do_skas(void)
 #else
 int can_do_skas(void)
 {
-	return(0);
+	return 0;
 }
 #endif
 
 int __init parse_iomem(char *str, int *add)
 {
 	struct iomem_region *new;
-	struct uml_stat buf;
+	struct stat64 buf;
 	char *file, *driver;
-	int fd, err, size;
+	int fd, size;
 
 	driver = str;
 	file = strchr(str,',');
@@ -462,15 +494,14 @@ int __init parse_iomem(char *str, int *add)
 	}
 	*file = '\0';
 	file++;
-	fd = os_open_file(file, of_rdwr(OPENFLAGS()), 0);
+	fd = open(file, O_RDWR, 0);
 	if(fd < 0){
 		os_print_error(fd, "parse_iomem - Couldn't open io file");
 		goto out;
 	}
 
-	err = os_stat_fd(fd, &buf);
-	if(err < 0){
-		os_print_error(err, "parse_iomem - cannot stat_fd file");
+	if(fstat64(fd, &buf) < 0){
+		perror("parse_iomem - cannot stat_fd file");
 		goto out_close;
 	}
 
@@ -480,7 +511,7 @@ int __init parse_iomem(char *str, int *add)
 		goto out_close;
 	}
 
-	size = (buf.ust_size + UM_KERN_PAGE_SIZE) & ~(UM_KERN_PAGE_SIZE - 1);
+	size = (buf.st_size + UM_KERN_PAGE_SIZE) & ~(UM_KERN_PAGE_SIZE - 1);
 
 	*new = ((struct iomem_region) { .next		= iomem_regions,
 					.driver		= driver,
@@ -491,11 +522,11 @@ int __init parse_iomem(char *str, int *add)
 	iomem_regions = new;
 	iomem_size += new->size + UM_KERN_PAGE_SIZE;
 
-	return(0);
+	return 0;
  out_close:
-	os_close_file(fd);
+	close(fd);
  out:
-	return(1);
+	return 1;
 }
 
 
@@ -526,6 +557,24 @@ static void openpty_cb(void *arg)
 		info->err = -errno;
 }
 
+static int async_pty(int master, int slave)
+{
+	int flags;
+
+	flags = fcntl(master, F_GETFL);
+	if(flags < 0)
+		return -errno;
+
+	if((fcntl(master, F_SETFL, flags | O_NONBLOCK | O_ASYNC) < 0) ||
+	   (fcntl(master, F_SETOWN, os_getpid()) < 0))
+		return -errno;
+
+	if((fcntl(slave, F_SETFL, flags | O_NONBLOCK) < 0))
+		return -errno;
+
+	return(0);
+}
+
 static void __init check_one_sigio(void (*proc)(int, int))
 {
 	struct sigaction old, new;
@@ -551,7 +600,7 @@ static void __init check_one_sigio(void (*proc)(int, int))
 	if (err < 0)
 		panic("check_sigio : __raw failed, errno = %d\n", -err);
 
-	err = os_sigio_async(master, slave);
+	err = async_pty(master, slave);
 	if(err < 0)
 		panic("tty_fds : sigio_async failed, err = %d\n", -err);
 
diff --git a/arch/um/os-Linux/sys-i386/registers.c b/arch/um/os-Linux/sys-i386/registers.c
index 7cd0369e02b..79cd93c8c5e 100644
--- a/arch/um/os-Linux/sys-i386/registers.c
+++ b/arch/um/os-Linux/sys-i386/registers.c
@@ -34,27 +34,27 @@ void init_thread_registers(union uml_pt_regs *to)
 int save_fp_registers(int pid, unsigned long *fp_regs)
 {
 	if(ptrace(PTRACE_GETFPREGS, pid, 0, fp_regs) < 0)
-		return(-errno);
-	return(0);
+		return -errno;
+	return 0;
 }
 
 int restore_fp_registers(int pid, unsigned long *fp_regs)
 {
 	if(ptrace(PTRACE_SETFPREGS, pid, 0, fp_regs) < 0)
-		return(-errno);
-	return(0);
+		return -errno;
+	return 0;
 }
 
 static int move_registers(int pid, int int_op, union uml_pt_regs *regs,
 			  int fp_op, unsigned long *fp_regs)
 {
 	if(ptrace(int_op, pid, 0, regs->skas.regs) < 0)
-		return(-errno);
+		return -errno;
 
 	if(ptrace(fp_op, pid, 0, fp_regs) < 0)
-		return(-errno);
+		return -errno;
 
-	return(0);
+	return 0;
 }
 
 void save_registers(int pid, union uml_pt_regs *regs)
diff --git a/arch/um/os-Linux/sys-x86_64/Makefile b/arch/um/os-Linux/sys-x86_64/Makefile
index f67842a7735..7955e061a67 100644
--- a/arch/um/os-Linux/sys-x86_64/Makefile
+++ b/arch/um/os-Linux/sys-x86_64/Makefile
@@ -3,7 +3,7 @@
 # Licensed under the GPL
 #
 
-obj-$(CONFIG_MODE_SKAS) = registers.o signal.o
+obj-$(CONFIG_MODE_SKAS) = registers.o prctl.o signal.o
 
 USER_OBJS := $(obj-y)
 
diff --git a/arch/um/os-Linux/sys-x86_64/prctl.c b/arch/um/os-Linux/sys-x86_64/prctl.c
new file mode 100644
index 00000000000..9d34eddb517
--- /dev/null
+++ b/arch/um/os-Linux/sys-x86_64/prctl.c
@@ -0,0 +1,12 @@
+/*
+ * Copyright (C) 2007 Jeff Dike (jdike@{addtoit.com,linux.intel.com})
+ * Licensed under the GPL
+ */
+
+#include <sys/ptrace.h>
+#include <linux/ptrace.h>
+
+int os_arch_prctl(int pid, int code, unsigned long *addr)
+{
+        return ptrace(PTRACE_ARCH_PRCTL, pid, (unsigned long) addr, code);
+}
diff --git a/arch/um/os-Linux/sys-x86_64/registers.c b/arch/um/os-Linux/sys-x86_64/registers.c
index cb8e8a26328..a2d7e0c603f 100644
--- a/arch/um/os-Linux/sys-x86_64/registers.c
+++ b/arch/um/os-Linux/sys-x86_64/registers.c
@@ -27,12 +27,12 @@ static int move_registers(int pid, int int_op, int fp_op,
 			  union uml_pt_regs *regs)
 {
 	if(ptrace(int_op, pid, 0, regs->skas.regs) < 0)
-		return(-errno);
+		return -errno;
 
 	if(ptrace(fp_op, pid, 0, regs->skas.fp) < 0)
-		return(-errno);
+		return -errno;
 
-	return(0);
+	return 0;
 }
 
 void save_registers(int pid, union uml_pt_regs *regs)
diff --git a/arch/um/os-Linux/umid.c b/arch/um/os-Linux/umid.c
index 48092b95c8a..b462863f717 100644
--- a/arch/um/os-Linux/umid.c
+++ b/arch/um/os-Linux/umid.c
@@ -18,7 +18,7 @@
 #define UMID_LEN 64
 
 /* Changed by set_umid, which is run early in boot */
-char umid[UMID_LEN] = { 0 };
+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;
@@ -235,6 +235,7 @@ int __init set_umid(char *name)
 	return 0;
 }
 
+/* Changed in make_umid, which is called during early boot */
 static int umid_setup = 0;
 
 int __init make_umid(void)
diff --git a/arch/um/sys-x86_64/ptrace.c b/arch/um/sys-x86_64/ptrace.c
index 147bbf05cbc..55b66e09a98 100644
--- a/arch/um/sys-x86_64/ptrace.c
+++ b/arch/um/sys-x86_64/ptrace.c
@@ -71,8 +71,6 @@ int poke_user(struct task_struct *child, long addr, long data)
 
         if (addr < MAX_REG_OFFSET)
                 return putreg(child, addr, data);
-
-#if 0 /* Need x86_64 debugregs handling */
         else if((addr >= offsetof(struct user, u_debugreg[0])) &&
                 (addr <= offsetof(struct user, u_debugreg[7]))){
                 addr -= offsetof(struct user, u_debugreg[0]);
@@ -81,7 +79,6 @@ int poke_user(struct task_struct *child, long addr, long data)
                 child->thread.arch.debugregs[addr] = data;
                 return 0;
         }
-#endif
         return -EIO;
 }
 
@@ -119,14 +116,12 @@ int peek_user(struct task_struct *child, long addr, long data)
         if(addr < MAX_REG_OFFSET){
                 tmp = getreg(child, addr);
         }
-#if 0 /* Need x86_64 debugregs handling */
         else if((addr >= offsetof(struct user, u_debugreg[0])) &&
                 (addr <= offsetof(struct user, u_debugreg[7]))){
                 addr -= offsetof(struct user, u_debugreg[0]);
                 addr = addr >> 2;
                 tmp = child->thread.arch.debugregs[addr];
         }
-#endif
         return put_user(tmp, (unsigned long *) data);
 }
 
diff --git a/arch/um/sys-x86_64/syscalls.c b/arch/um/sys-x86_64/syscalls.c
index 73ce4463f70..01b91f9fa78 100644
--- a/arch/um/sys-x86_64/syscalls.c
+++ b/arch/um/sys-x86_64/syscalls.c
@@ -16,6 +16,7 @@
 #include "asm/prctl.h" /* XXX This should get the constants from libc */
 #include "choose-mode.h"
 #include "kern.h"
+#include "os.h"
 
 asmlinkage long sys_uname64(struct new_utsname __user * name)
 {
@@ -58,40 +59,69 @@ static long arch_prctl_tt(int code, unsigned long addr)
 
 #ifdef CONFIG_MODE_SKAS
 
-/* XXX: Must also call arch_prctl in the host, beside saving the segment bases! */
-static long arch_prctl_skas(int code, unsigned long addr)
+long arch_prctl_skas(struct task_struct *task, int code,
+                     unsigned long __user *addr)
 {
-	long ret = 0;
+        unsigned long *ptr = addr, tmp;
+	long ret;
+	int pid = task->mm->context.skas.id.u.pid;
 
+	/*
+	 * With ARCH_SET_FS (and ARCH_SET_GS is treated similarly to
+	 * be safe), we need to call arch_prctl on the host because
+	 * setting %fs may result in something else happening (like a
+	 * GDT or thread.fs being set instead).  So, we let the host
+	 * fiddle the registers and thread struct and restore the
+	 * registers afterwards.
+	 *
+	 * So, the saved registers are stored to the process (this
+	 * needed because a stub may have been the last thing to run),
+	 * arch_prctl is run on the host, then the registers are read
+	 * back.
+	 */
 	switch(code){
 	case ARCH_SET_FS:
-		current->thread.regs.regs.skas.regs[FS_BASE / sizeof(unsigned long)] = addr;
-		break;
 	case ARCH_SET_GS:
-		current->thread.regs.regs.skas.regs[GS_BASE / sizeof(unsigned long)] = addr;
+                restore_registers(pid, &current->thread.regs.regs);
+                break;
+        case ARCH_GET_FS:
+        case ARCH_GET_GS:
+                /*
+                 * With these two, we read to a local pointer and
+                 * put_user it to the userspace pointer that we were
+                 * given.  If addr isn't valid (because it hasn't been
+                 * faulted in or is just bogus), we want put_user to
+                 * fault it in (or return -EFAULT) instead of having
+                 * the host return -EFAULT.
+                 */
+                ptr = &tmp;
+        }
+
+        ret = os_arch_prctl(pid, code, ptr);
+        if(ret)
+                return ret;
+
+        switch(code){
+	case ARCH_SET_FS:
+	case ARCH_SET_GS:
+                save_registers(pid, &current->thread.regs.regs);
 		break;
 	case ARCH_GET_FS:
-		ret = put_user(current->thread.regs.regs.skas.
-				regs[FS_BASE / sizeof(unsigned long)],
-				(unsigned long __user *)addr);
+		ret = put_user(tmp, addr);
 	        break;
 	case ARCH_GET_GS:
-		ret = put_user(current->thread.regs.regs.skas.
-				regs[GS_BASE / sizeof(unsigned long)],
-				(unsigned long __user *)addr);
+		ret = put_user(tmp, addr);
 	        break;
-	default:
-		ret = -EINVAL;
-		break;
 	}
 
-	return(ret);
+	return ret;
 }
 #endif
 
 long sys_arch_prctl(int code, unsigned long addr)
 {
-	return(CHOOSE_MODE_PROC(arch_prctl_tt, arch_prctl_skas, code, addr));
+	return CHOOSE_MODE_PROC(arch_prctl_tt, arch_prctl_skas, current, code,
+                                (unsigned long __user *) addr);
 }
 
 long sys_clone(unsigned long clone_flags, unsigned long newsp,
@@ -105,5 +135,14 @@ long sys_clone(unsigned long clone_flags, unsigned long newsp,
 	ret = do_fork(clone_flags, newsp, &current->thread.regs, 0, parent_tid,
 		      child_tid);
 	current->thread.forking = 0;
-	return(ret);
+	return ret;
+}
+
+void arch_switch_to_skas(struct task_struct *from, struct task_struct *to)
+{
+        if(to->thread.arch.fs == 0)
+                return;
+
+        arch_prctl_skas(to, ARCH_SET_FS, (void __user *) to->thread.arch.fs);
 }
+
diff --git a/arch/um/sys-x86_64/tls.c b/arch/um/sys-x86_64/tls.c
index ce1bf1b81c4..febbc94be25 100644
--- a/arch/um/sys-x86_64/tls.c
+++ b/arch/um/sys-x86_64/tls.c
@@ -1,14 +1,17 @@
 #include "linux/sched.h"
 
-void debug_arch_force_load_TLS(void)
-{
-}
-
 void clear_flushed_tls(struct task_struct *task)
 {
 }
 
 int arch_copy_tls(struct task_struct *t)
 {
+	/*
+	 * If CLONE_SETTLS is set, we need to save the thread id
+	 * (which is argument 5, child_tid, of clone) so it can be set
+	 * during context switches.
+	 */
+	t->thread.arch.fs = t->thread.regs.regs.skas.regs[R8 / sizeof(long)];
+
         return 0;
 }