Merge branch 'master' into gfs2

98 files changed, 1448 insertions, 826 deletions

diff --git a/arch/um/Makefile-x86_64 b/arch/um/Makefile-x86_64
index 9558a7c..11154b6 100644
--- a/arch/um/Makefile-x86_64
+++ b/arch/um/Makefile-x86_64
@@ -4,10 +4,13 @@
 core-y += arch/um/sys-x86_64/
 START := 0x60000000
 
+_extra_flags_ = -fno-builtin -m64 -mcmodel=kernel
+
 #We #undef __x86_64__ for kernelspace, not for userspace where
 #it's needed for headers to work!
-CFLAGS += -U__$(SUBARCH)__ -fno-builtin -m64
-USER_CFLAGS += -fno-builtin -m64
+CFLAGS += -U__$(SUBARCH)__ $(_extra_flags_)
+USER_CFLAGS += $(_extra_flags_)
+
 CHECKFLAGS  += -m64
 AFLAGS += -m64
 LDFLAGS += -m elf_x86_64
diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index 7218c75..3576b3c 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -110,7 +110,7 @@ static void not_configged_free(void *data)
 	       "UML\n");
 }
 
-static struct chan_ops not_configged_ops = {
+static const struct chan_ops not_configged_ops = {
 	.init		= not_configged_init,
 	.open		= not_configged_open,
 	.close		= not_configged_close,
@@ -373,7 +373,7 @@ int console_write_chan(struct list_head *chans, const char *buf, int len)
 }
 
 int console_open_chan(struct line *line, struct console *co,
-		      struct chan_opts *opts)
+		      const struct chan_opts *opts)
 {
 	int err;
 
@@ -494,10 +494,10 @@ int chan_config_string(struct list_head *chans, char *str, int size,
 
 struct chan_type {
 	char *key;
-	struct chan_ops *ops;
+	const struct chan_ops *ops;
 };
 
-static struct chan_type chan_table[] = {
+static const struct chan_type chan_table[] = {
 	{ "fd", &fd_ops },
 
 #ifdef CONFIG_NULL_CHAN
@@ -534,17 +534,17 @@ static struct chan_type chan_table[] = {
 };
 
 static struct chan *parse_chan(struct line *line, char *str, int device,
-			       struct chan_opts *opts)
+			       const struct chan_opts *opts)
 {
-	struct chan_type *entry;
-	struct chan_ops *ops;
+	const struct chan_type *entry;
+	const struct chan_ops *ops;
 	struct chan *chan;
 	void *data;
 	int i;
 
 	ops = NULL;
 	data = NULL;
-	for(i = 0; i < sizeof(chan_table)/sizeof(chan_table[0]); i++){
+	for(i = 0; i < ARRAY_SIZE(chan_table); i++){
 		entry = &chan_table[i];
 		if(!strncmp(str, entry->key, strlen(entry->key))){
 			ops = entry->ops;
@@ -582,7 +582,7 @@ static struct chan *parse_chan(struct line *line, char *str, int device,
 }
 
 int parse_chan_pair(char *str, struct line *line, int device,
-		    struct chan_opts *opts)
+		    const struct chan_opts *opts)
 {
 	struct list_head *chans = &line->chan_list;
 	struct chan *new, *chan;
diff --git a/arch/um/drivers/daemon.h b/arch/um/drivers/daemon.h
index 7326c42..3bc3cf6 100644
--- a/arch/um/drivers/daemon.h
+++ b/arch/um/drivers/daemon.h
@@ -18,7 +18,7 @@ struct daemon_data {
 	void *dev;
 };
 
-extern struct net_user_info daemon_user_info;
+extern const struct net_user_info daemon_user_info;
 
 extern int daemon_user_write(int fd, void *buf, int len, 
 			     struct daemon_data *pri);
diff --git a/arch/um/drivers/daemon_kern.c b/arch/um/drivers/daemon_kern.c
index 53d09ed..8243869 100644
--- a/arch/um/drivers/daemon_kern.c
+++ b/arch/um/drivers/daemon_kern.c
@@ -57,7 +57,7 @@ static int daemon_write(int fd, struct sk_buff **skb,
 				 (struct daemon_data *) &lp->user));
 }
 
-static struct net_kern_info daemon_kern_info = {
+static const struct net_kern_info daemon_kern_info = {
 	.init			= daemon_init,
 	.protocol		= eth_protocol,
 	.read			= daemon_read,
diff --git a/arch/um/drivers/daemon_user.c b/arch/um/drivers/daemon_user.c
index c944265..77954ea 100644
--- a/arch/um/drivers/daemon_user.c
+++ b/arch/um/drivers/daemon_user.c
@@ -182,7 +182,7 @@ static int daemon_set_mtu(int mtu, void *data)
 	return(mtu);
 }
 
-struct net_user_info daemon_user_info = {
+const struct net_user_info daemon_user_info = {
 	.init		= daemon_user_init,
 	.open		= daemon_open,
 	.close	 	= NULL,
diff --git a/arch/um/drivers/fd.c b/arch/um/drivers/fd.c
index c41f75e..108b7da 100644
--- a/arch/um/drivers/fd.c
+++ b/arch/um/drivers/fd.c
@@ -20,7 +20,7 @@ struct fd_chan {
 	char str[sizeof("1234567890\0")];
 };
 
-static void *fd_init(char *str, int device, struct chan_opts *opts)
+static void *fd_init(char *str, int device, const struct chan_opts *opts)
 {
 	struct fd_chan *data;
 	char *end;
@@ -77,7 +77,7 @@ static void fd_close(int fd, void *d)
 	}
 }
 
-struct chan_ops fd_ops = {
+const struct chan_ops fd_ops = {
 	.type		= "fd",
 	.init		= fd_init,
 	.open		= fd_open,
diff --git a/arch/um/drivers/hostaudio_kern.c b/arch/um/drivers/hostaudio_kern.c
index 37232f9..d247ef4 100644
--- a/arch/um/drivers/hostaudio_kern.c
+++ b/arch/um/drivers/hostaudio_kern.c
@@ -280,7 +280,7 @@ static int hostmixer_release(struct inode *inode, struct file *file)
 
 /* kernel module operations */
 
-static struct file_operations hostaudio_fops = {
+static const struct file_operations hostaudio_fops = {
         .owner          = THIS_MODULE,
         .llseek         = no_llseek,
         .read           = hostaudio_read,
@@ -292,7 +292,7 @@ static struct file_operations hostaudio_fops = {
         .release        = hostaudio_release,
 };
 
-static struct file_operations hostmixer_fops = {
+static const struct file_operations hostmixer_fops = {
         .owner          = THIS_MODULE,
         .llseek         = no_llseek,
         .ioctl          = hostmixer_ioctl_mixdev,
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index ebebaab..563ce76 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -251,7 +251,7 @@ void line_set_termios(struct tty_struct *tty, struct termios * old)
 	/* nothing */
 }
 
-static struct {
+static const struct {
 	int  cmd;
 	char *level;
 	char *name;
@@ -405,7 +405,7 @@ static irqreturn_t line_write_interrupt(int irq, void *data,
 
 int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
 {
-	struct line_driver *driver = line->driver;
+	const struct line_driver *driver = line->driver;
 	int err = 0, flags = IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM;
 
 	if (input)
@@ -558,7 +558,7 @@ int line_setup(struct line *lines, unsigned int num, char *init)
 }
 
 int line_config(struct line *lines, unsigned int num, char *str,
-		struct chan_opts *opts)
+		const struct chan_opts *opts)
 {
 	struct line *line;
 	char *new;
diff --git a/arch/um/drivers/mcast.h b/arch/um/drivers/mcast.h
index a2c6db2..bc56af9 100644
--- a/arch/um/drivers/mcast.h
+++ b/arch/um/drivers/mcast.h
@@ -13,7 +13,7 @@ struct mcast_data {
 	void *dev;
 };
 
-extern struct net_user_info mcast_user_info;
+extern const struct net_user_info mcast_user_info;
 
 extern int mcast_user_write(int fd, void *buf, int len, 
 			    struct mcast_data *pri);
diff --git a/arch/um/drivers/mcast_kern.c b/arch/um/drivers/mcast_kern.c
index 3a7af18..c090fbd 100644
--- a/arch/um/drivers/mcast_kern.c
+++ b/arch/um/drivers/mcast_kern.c
@@ -61,7 +61,7 @@ static int mcast_write(int fd, struct sk_buff **skb,
 				 (struct mcast_data *) &lp->user);
 }
 
-static struct net_kern_info mcast_kern_info = {
+static const struct net_kern_info mcast_kern_info = {
 	.init			= mcast_init,
 	.protocol		= eth_protocol,
 	.read			= mcast_read,
diff --git a/arch/um/drivers/mcast_user.c b/arch/um/drivers/mcast_user.c
index afe85bf..4d2bd39 100644
--- a/arch/um/drivers/mcast_user.c
+++ b/arch/um/drivers/mcast_user.c
@@ -152,7 +152,7 @@ static int mcast_set_mtu(int mtu, void *data)
 	return(mtu);
 }
 
-struct net_user_info mcast_user_info = {
+const struct net_user_info mcast_user_info = {
 	.init		= mcast_user_init,
 	.open		= mcast_open,
 	.close	 	= mcast_close,
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index b414522..79610b5 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -497,7 +497,7 @@ static void mconsole_get_config(int (*get_config)(char *, char *, int,
 	}
 
 	error = NULL;
-	size = sizeof(default_buf)/sizeof(default_buf[0]);
+	size = ARRAY_SIZE(default_buf);
 	buf = default_buf;
 
 	while(1){
diff --git a/arch/um/drivers/mconsole_user.c b/arch/um/drivers/mconsole_user.c
index 9bfd405..5b2f5fe 100644
--- a/arch/um/drivers/mconsole_user.c
+++ b/arch/um/drivers/mconsole_user.c
@@ -16,6 +16,7 @@
 #include "user.h"
 #include "mconsole.h"
 #include "umid.h"
+#include "user_util.h"
 
 static struct mconsole_command commands[] = {
 	/* With uts namespaces, uts information becomes process-specific, so
@@ -65,14 +66,14 @@ static struct mconsole_command *mconsole_parse(struct mc_request *req)
 	struct mconsole_command *cmd;
 	int i;
 
-	for(i=0;i<sizeof(commands)/sizeof(commands[0]);i++){
+	for(i = 0; i < ARRAY_SIZE(commands); i++){
 		cmd = &commands[i];
 		if(!strncmp(req->request.data, cmd->command, 
 			    strlen(cmd->command))){
-			return(cmd);
+			return cmd;
 		}
 	}
-	return(NULL);
+	return NULL;
 }
 
 #define MIN(a,b) ((a)<(b) ? (a):(b))
diff --git a/arch/um/drivers/mmapper_kern.c b/arch/um/drivers/mmapper_kern.c
index 022f67b..9a3b5da 100644
--- a/arch/um/drivers/mmapper_kern.c
+++ b/arch/um/drivers/mmapper_kern.c
@@ -85,7 +85,7 @@ mmapper_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
-static struct file_operations mmapper_fops = {
+static const struct file_operations mmapper_fops = {
 	.owner		= THIS_MODULE,
 	.read		= mmapper_read,
 	.write		= mmapper_write,
@@ -95,7 +95,7 @@ static struct file_operations mmapper_fops = {
 	.release	= mmapper_release,
 };
 
-static struct miscdevice mmapper_dev = {
+static const struct miscdevice mmapper_dev = {
 	.minor		= MISC_DYNAMIC_MINOR,
 	.name		= "mmapper",
 	.fops		= &mmapper_fops
diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
index 501f956..664c2e2 100644
--- a/arch/um/drivers/net_kern.c
+++ b/arch/um/drivers/net_kern.c
@@ -31,6 +31,11 @@
 #include "irq_user.h"
 #include "irq_kern.h"
 
+static inline void set_ether_mac(struct net_device *dev, unsigned char *addr)
+{
+	memcpy(dev->dev_addr, addr, ETH_ALEN);
+}
+
 #define DRIVER_NAME "uml-netdev"
 
 static DEFINE_SPINLOCK(opened_lock);
@@ -109,8 +114,6 @@ static int uml_net_open(struct net_device *dev)
 	struct uml_net_private *lp = dev->priv;
 	int err;
 
-	spin_lock(&lp->lock);
-
 	if(lp->fd >= 0){
 		err = -ENXIO;
 		goto out;
@@ -144,8 +147,6 @@ static int uml_net_open(struct net_device *dev)
 	 */
 	while((err = uml_net_rx(dev)) > 0) ;
 
-	spin_unlock(&lp->lock);
-
 	spin_lock(&opened_lock);
 	list_add(&lp->list, &opened);
 	spin_unlock(&opened_lock);
@@ -155,7 +156,6 @@ out_close:
 	if(lp->close != NULL) (*lp->close)(lp->fd, &lp->user);
 	lp->fd = -1;
 out:
-	spin_unlock(&lp->lock);
 	return err;
 }
 
@@ -164,15 +164,12 @@ static int uml_net_close(struct net_device *dev)
 	struct uml_net_private *lp = dev->priv;
 	
 	netif_stop_queue(dev);
-	spin_lock(&lp->lock);
 
 	free_irq(dev->irq, dev);
 	if(lp->close != NULL)
 		(*lp->close)(lp->fd, &lp->user);
 	lp->fd = -1;
 
-	spin_unlock(&lp->lock);
-
 	spin_lock(&opened_lock);
 	list_del(&lp->list);
 	spin_unlock(&opened_lock);
@@ -241,9 +238,9 @@ static int uml_net_set_mac(struct net_device *dev, void *addr)
 	struct uml_net_private *lp = dev->priv;
 	struct sockaddr *hwaddr = addr;
 
-	spin_lock(&lp->lock);
-	memcpy(dev->dev_addr, hwaddr->sa_data, ETH_ALEN);
-	spin_unlock(&lp->lock);
+	spin_lock_irq(&lp->lock);
+	set_ether_mac(dev, hwaddr->sa_data);
+	spin_unlock_irq(&lp->lock);
 
 	return(0);
 }
@@ -253,7 +250,7 @@ static int uml_net_change_mtu(struct net_device *dev, int new_mtu)
 	struct uml_net_private *lp = dev->priv;
 	int err = 0;
 
-	spin_lock(&lp->lock);
+	spin_lock_irq(&lp->lock);
 
 	new_mtu = (*lp->set_mtu)(new_mtu, &lp->user);
 	if(new_mtu < 0){
@@ -264,7 +261,7 @@ static int uml_net_change_mtu(struct net_device *dev, int new_mtu)
 	dev->mtu = new_mtu;
 
  out:
-	spin_unlock(&lp->lock);
+	spin_unlock_irq(&lp->lock);
 	return err;
 }
 
@@ -564,12 +561,13 @@ static int eth_setup(char *str)
 	int n, err;
 
 	err = eth_parse(str, &n, &str);
-	if(err) return(1);
+	if(err)
+		return 1;
 
-	new = alloc_bootmem(sizeof(new));
+	new = alloc_bootmem(sizeof(*new));
 	if (new == NULL){
 		printk("eth_init : alloc_bootmem failed\n");
-		return(1);
+		return 1;
 	}
 
 	INIT_LIST_HEAD(&new->list);
@@ -577,7 +575,7 @@ static int eth_setup(char *str)
 	new->init = str;
 
 	list_add_tail(&new->list, &eth_cmd_line);
-	return(1);
+	return 1;
 }
 
 __setup("eth", eth_setup);
@@ -790,13 +788,6 @@ void dev_ip_addr(void *d, unsigned char *bin_buf)
 	memcpy(bin_buf, &in->ifa_address, sizeof(in->ifa_address));
 }
 
-void set_ether_mac(void *d, unsigned char *addr)
-{
-	struct net_device *dev = d;
-
-	memcpy(dev->dev_addr, addr, ETH_ALEN);	
-}
-
 struct sk_buff *ether_adjust_skb(struct sk_buff *skb, int extra)
 {
 	if((skb != NULL) && (skb_tailroom(skb) < extra)){
diff --git a/arch/um/drivers/null.c b/arch/um/drivers/null.c
index 14cc5f7..3683ed4 100644
--- a/arch/um/drivers/null.c
+++ b/arch/um/drivers/null.c
@@ -10,7 +10,7 @@
 
 static int null_chan;
 
-static void *null_init(char *str, int device, struct chan_opts *opts)
+static void *null_init(char *str, int device, const struct chan_opts *opts)
 {
 	return(&null_chan);
 }
@@ -31,7 +31,7 @@ static void null_free(void *data)
 {
 }
 
-struct chan_ops null_ops = {
+const struct chan_ops null_ops = {
 	.type		= "null",
 	.init		= null_init,
 	.open		= null_open,
diff --git a/arch/um/drivers/pcap_kern.c b/arch/um/drivers/pcap_kern.c
index 466ff2c..6e1ef85 100644
--- a/arch/um/drivers/pcap_kern.c
+++ b/arch/um/drivers/pcap_kern.c
@@ -46,7 +46,7 @@ static int pcap_write(int fd, struct sk_buff **skb, struct uml_net_private *lp)
 	return(-EPERM);
 }
 
-static struct net_kern_info pcap_kern_info = {
+static const struct net_kern_info pcap_kern_info = {
 	.init			= pcap_init,
 	.protocol		= eth_protocol,
 	.read			= pcap_read,
@@ -76,7 +76,7 @@ int pcap_setup(char *str, char **mac_out, void *data)
 	if(host_if != NULL)
 		init->host_if = host_if;
 
-	for(i = 0; i < sizeof(options)/sizeof(options[0]); i++){
+	for(i = 0; i < ARRAY_SIZE(options); i++){
 		if(options[i] == NULL)
 			continue;
 		if(!strcmp(options[i], "promisc"))
diff --git a/arch/um/drivers/pcap_user.c b/arch/um/drivers/pcap_user.c
index edfcb29..2ef641d 100644
--- a/arch/um/drivers/pcap_user.c
+++ b/arch/um/drivers/pcap_user.c
@@ -120,7 +120,7 @@ int pcap_user_read(int fd, void *buffer, int len, struct pcap_data *pri)
 	return(hdata.len);
 }
 
-struct net_user_info pcap_user_info = {
+const struct net_user_info pcap_user_info = {
 	.init		= pcap_user_init,
 	.open		= pcap_open,
 	.close	 	= NULL,
diff --git a/arch/um/drivers/port_user.c b/arch/um/drivers/port_user.c
index c43e8bb..f2e8fc4 100644
--- a/arch/um/drivers/port_user.c
+++ b/arch/um/drivers/port_user.c
@@ -27,7 +27,7 @@ struct port_chan {
 	char dev[sizeof("32768\0")];
 };
 
-static void *port_init(char *str, int device, struct chan_opts *opts)
+static void *port_init(char *str, int device, const struct chan_opts *opts)
 {
 	struct port_chan *data;
 	void *kern_data;
@@ -100,7 +100,7 @@ static void port_close(int fd, void *d)
 	os_close_file(fd);
 }
 
-struct chan_ops port_ops = {
+const struct chan_ops port_ops = {
 	.type		= "port",
 	.init		= port_init,
 	.open		= port_open,
diff --git a/arch/um/drivers/pty.c b/arch/um/drivers/pty.c
index 1c555c3..abec620 100644
--- a/arch/um/drivers/pty.c
+++ b/arch/um/drivers/pty.c
@@ -22,7 +22,7 @@ struct pty_chan {
 	char dev_name[sizeof("/dev/pts/0123456\0")];
 };
 
-static void *pty_chan_init(char *str, int device, struct chan_opts *opts)
+static void *pty_chan_init(char *str, int device, const struct chan_opts *opts)
 {
 	struct pty_chan *data;
 
@@ -118,7 +118,7 @@ static int pty_open(int input, int output, int primary, void *d,
 	return(fd);
 }
 
-struct chan_ops pty_ops = {
+const struct chan_ops pty_ops = {
 	.type		= "pty",
 	.init		= pty_chan_init,
 	.open		= pty_open,
@@ -131,7 +131,7 @@ struct chan_ops pty_ops = {
 	.winch		= 0,
 };
 
-struct chan_ops pts_ops = {
+const struct chan_ops pts_ops = {
 	.type		= "pts",
 	.init		= pty_chan_init,
 	.open		= pts_open,
diff --git a/arch/um/drivers/random.c b/arch/um/drivers/random.c
index ba471f5..ae99094 100644
--- a/arch/um/drivers/random.c
+++ b/arch/um/drivers/random.c
@@ -68,7 +68,7 @@ static ssize_t rng_dev_read (struct file *filp, char __user *buf, size_t size,
 	return ret;
 }
 
-static struct file_operations rng_chrdev_ops = {
+static const struct file_operations rng_chrdev_ops = {
 	.owner		= THIS_MODULE,
 	.open		= rng_dev_open,
 	.read		= rng_dev_read,
diff --git a/arch/um/drivers/slip.h b/arch/um/drivers/slip.h
index bb0dab4..c64f8c6 100644
--- a/arch/um/drivers/slip.h
+++ b/arch/um/drivers/slip.h
@@ -12,7 +12,7 @@ struct slip_data {
 	struct slip_proto slip;
 };
 
-extern struct net_user_info slip_user_info;
+extern const struct net_user_info slip_user_info;
 
 extern int slip_user_read(int fd, void *buf, int len, struct slip_data *pri);
 extern int slip_user_write(int fd, void *buf, int len, struct slip_data *pri);
diff --git a/arch/um/drivers/slip_kern.c b/arch/um/drivers/slip_kern.c
index 163ee0d..ccea2d7 100644
--- a/arch/um/drivers/slip_kern.c
+++ b/arch/um/drivers/slip_kern.c
@@ -61,7 +61,7 @@ static int slip_write(int fd, struct sk_buff **skb,
 			       (struct slip_data *) &lp->user));
 }
 
-struct net_kern_info slip_kern_info = {
+const struct net_kern_info slip_kern_info = {
 	.init			= slip_init,
 	.protocol		= slip_protocol,
 	.read			= slip_read,
diff --git a/arch/um/drivers/slip_user.c b/arch/um/drivers/slip_user.c
index 89fbec1..8460285 100644
--- a/arch/um/drivers/slip_user.c
+++ b/arch/um/drivers/slip_user.c
@@ -241,7 +241,7 @@ static void slip_del_addr(unsigned char *addr, unsigned char *netmask,
 	close_addr(addr, netmask, pri->name);
 }
 
-struct net_user_info slip_user_info = {
+const struct net_user_info slip_user_info = {
 	.init		= slip_user_init,
 	.open		= slip_open,
 	.close	 	= slip_close,
diff --git a/arch/um/drivers/slirp.h b/arch/um/drivers/slirp.h
index 6cf88ab..89ccf83 100644
--- a/arch/um/drivers/slirp.h
+++ b/arch/um/drivers/slirp.h
@@ -24,7 +24,7 @@ struct slirp_data {
 	struct slip_proto slip;
 };
 
-extern struct net_user_info slirp_user_info;
+extern const struct net_user_info slirp_user_info;
 
 extern int slirp_user_read(int fd, void *buf, int len, struct slirp_data *pri);
 extern int slirp_user_write(int fd, void *buf, int len,
diff --git a/arch/um/drivers/slirp_kern.c b/arch/um/drivers/slirp_kern.c
index 95e50c9..ae322e1 100644
--- a/arch/um/drivers/slirp_kern.c
+++ b/arch/um/drivers/slirp_kern.c
@@ -64,7 +64,7 @@ static int slirp_write(int fd, struct sk_buff **skb,
 			       (struct slirp_data *) &lp->user));
 }
 
-struct net_kern_info slirp_kern_info = {
+const struct net_kern_info slirp_kern_info = {
 	.init			= slirp_init,
 	.protocol		= slirp_protocol,
 	.read			= slirp_read,
diff --git a/arch/um/drivers/slirp_user.c b/arch/um/drivers/slirp_user.c
index 33c5f6e..ce5e85d 100644
--- a/arch/um/drivers/slirp_user.c
+++ b/arch/um/drivers/slirp_user.c
@@ -126,7 +126,7 @@ static int slirp_set_mtu(int mtu, void *data)
 	return(mtu);
 }
 
-struct net_user_info slirp_user_info = {
+const struct net_user_info slirp_user_info = {
 	.init		= slirp_user_init,
 	.open		= slirp_open,
 	.close	 	= slirp_close,
diff --git a/arch/um/drivers/ssl.c b/arch/um/drivers/ssl.c
index 6dafd6f..6f13e7c 100644
--- a/arch/um/drivers/ssl.c
+++ b/arch/um/drivers/ssl.c
@@ -23,7 +23,7 @@
 #include "irq_user.h"
 #include "mconsole_kern.h"
 
-static int ssl_version = 1;
+static const int ssl_version = 1;
 
 /* Referenced only by tty_driver below - presumably it's locked correctly
  * by the tty driver.
@@ -123,7 +123,7 @@ void ssl_hangup(struct tty_struct *tty)
 }
 #endif
 
-static struct tty_operations ssl_ops = {
+static const struct tty_operations ssl_ops = {
 	.open 	 		= ssl_open,
 	.close 	 		= line_close,
 	.write 	 		= line_write,
diff --git a/arch/um/drivers/stdio_console.c b/arch/um/drivers/stdio_console.c
index 856f568..5e44adb 100644
--- a/arch/um/drivers/stdio_console.c
+++ b/arch/um/drivers/stdio_console.c
@@ -110,7 +110,7 @@ static int con_open(struct tty_struct *tty, struct file *filp)
 
 static int con_init_done = 0;
 
-static struct tty_operations console_ops = {
+static const struct tty_operations console_ops = {
 	.open 	 		= con_open,
 	.close 	 		= line_close,
 	.write 	 		= line_write,
diff --git a/arch/um/drivers/tty.c b/arch/um/drivers/tty.c
index 9f70edf..11de3ac 100644
--- a/arch/um/drivers/tty.c
+++ b/arch/um/drivers/tty.c
@@ -18,7 +18,7 @@ struct tty_chan {
 	struct termios tt;
 };
 
-static void *tty_chan_init(char *str, int device, struct chan_opts *opts)
+static void *tty_chan_init(char *str, int device, const struct chan_opts *opts)
 {
 	struct tty_chan *data;
 
@@ -62,7 +62,7 @@ static int tty_open(int input, int output, int primary, void *d,
 	return fd;
 }
 
-struct chan_ops tty_ops = {
+const struct chan_ops tty_ops = {
 	.type		= "tty",
 	.init		= tty_chan_init,
 	.open		= tty_open,
diff --git a/arch/um/drivers/xterm.c b/arch/um/drivers/xterm.c
index aaa63666..386f8b9 100644
--- a/arch/um/drivers/xterm.c
+++ b/arch/um/drivers/xterm.c
@@ -31,7 +31,7 @@ struct xterm_chan {
 };
 
 /* Not static because it's called directly by the tt mode gdb code */
-void *xterm_init(char *str, int device, struct chan_opts *opts)
+void *xterm_init(char *str, int device, const struct chan_opts *opts)
 {
 	struct xterm_chan *data;
 
@@ -194,7 +194,7 @@ static void xterm_free(void *d)
 	free(d);
 }
 
-struct chan_ops xterm_ops = {
+const struct chan_ops xterm_ops = {
 	.type		= "xterm",
 	.init		= xterm_init,
 	.open		= xterm_open,
diff --git a/arch/um/include/chan_kern.h b/arch/um/include/chan_kern.h
index 1bb5e9d..572d286 100644
--- a/arch/um/include/chan_kern.h
+++ b/arch/um/include/chan_kern.h
@@ -23,21 +23,21 @@ struct chan {
 	unsigned int opened:1;
 	unsigned int enabled:1;
 	int fd;
-	struct chan_ops *ops;
+	const struct chan_ops *ops;
 	void *data;
 };
 
 extern void chan_interrupt(struct list_head *chans, struct work_struct *task,
 			   struct tty_struct *tty, int irq);
 extern int parse_chan_pair(char *str, struct line *line, int device,
-			   struct chan_opts *opts);
+			   const struct chan_opts *opts);
 extern int open_chan(struct list_head *chans);
 extern int write_chan(struct list_head *chans, const char *buf, int len,
 			     int write_irq);
 extern int console_write_chan(struct list_head *chans, const char *buf, 
 			      int len);
 extern int console_open_chan(struct line *line, struct console *co,
-			     struct chan_opts *opts);
+			     const struct chan_opts *opts);
 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 659bb3c..a795547 100644
--- a/arch/um/include/chan_user.h
+++ b/arch/um/include/chan_user.h
@@ -20,7 +20,7 @@ enum chan_init_pri { INIT_STATIC, INIT_ALL, INIT_ONE };
 
 struct chan_ops {
 	char *type;
-	void *(*init)(char *, int, struct chan_opts *);
+	void *(*init)(char *, int, const struct chan_opts *);
 	int (*open)(int, int, int, void *, char **);
 	void (*close)(int, void *);
 	int (*read)(int, char *, void *);
@@ -31,8 +31,8 @@ struct chan_ops {
 	int winch;
 };
 
-extern struct chan_ops fd_ops, null_ops, port_ops, pts_ops, pty_ops, tty_ops,
-	xterm_ops;
+extern const struct chan_ops fd_ops, null_ops, port_ops, pts_ops, pty_ops,
+	tty_ops, xterm_ops;
 
 extern void generic_close(int fd, void *unused);
 extern int generic_read(int fd, char *c_out, void *unused);
diff --git a/arch/um/include/kern_util.h b/arch/um/include/kern_util.h
index b98bdd8..59cfa9e 100644
--- a/arch/um/include/kern_util.h
+++ b/arch/um/include/kern_util.h
@@ -21,13 +21,12 @@ struct kern_handlers {
 	kern_hndl timer_handler;
 };
 
-extern struct kern_handlers handlinfo_kern;
+extern const struct kern_handlers handlinfo_kern;
 
 extern int ncpus;
 extern char *linux_prog;
 extern char *gdb_init;
 extern int kmalloc_ok;
-extern int timer_irq_inited;
 extern int jail;
 extern int nsyscalls;
 
diff --git a/arch/um/include/line.h b/arch/um/include/line.h
index 27bf2f6..642c9a0 100644
--- a/arch/um/include/line.h
+++ b/arch/um/include/line.h
@@ -52,7 +52,7 @@ struct line {
 
 	int sigio;
 	struct work_struct task;
-	struct line_driver *driver;
+	const struct line_driver *driver;
 	int have_irq;
 };
 
@@ -99,7 +99,7 @@ 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, struct chan_opts *opts);
+		       char *str, const struct chan_opts *opts);
 extern int line_id(char **str, int *start_out, int *end_out);
 extern int line_remove(struct line *lines, unsigned int sizeof_lines, int n);
 extern int line_get_config(char *dev, struct line *lines,
diff --git a/arch/um/include/longjmp.h b/arch/um/include/longjmp.h
index 1b5c013..e93c6d3 100644
--- a/arch/um/include/longjmp.h
+++ b/arch/um/include/longjmp.h
@@ -1,9 +1,12 @@
 #ifndef __UML_LONGJMP_H
 #define __UML_LONGJMP_H
 
-#include <setjmp.h>
+#include "sysdep/archsetjmp.h"
 #include "os.h"
 
+extern int setjmp(jmp_buf);
+extern void longjmp(jmp_buf, int);
+
 #define UML_LONGJMP(buf, val) do { \
 	longjmp(*buf, val);	\
 } while(0)
diff --git a/arch/um/include/net_kern.h b/arch/um/include/net_kern.h
index f7de6df..769fba4 100644
--- a/arch/um/include/net_kern.h
+++ b/arch/um/include/net_kern.h
@@ -54,8 +54,8 @@ struct transport {
 	struct list_head list;
 	char *name;
 	int (*setup)(char *, char **, void *);
-	struct net_user_info *user;
-	struct net_kern_info *kern;
+	const struct net_user_info *user;
+	const struct net_kern_info *kern;
 	int private_size;
 	int setup_size;
 };
diff --git a/arch/um/include/net_user.h b/arch/um/include/net_user.h
index 800c403..47ef7cb 100644
--- a/arch/um/include/net_user.h
+++ b/arch/um/include/net_user.h
@@ -26,7 +26,6 @@ struct net_user_info {
 
 extern void ether_user_init(void *data, void *dev);
 extern void dev_ip_addr(void *d, unsigned char *bin_buf);
-extern void set_ether_mac(void *d, unsigned char *addr);
 extern void iter_addresses(void *d, void (*cb)(unsigned char *, 
 					       unsigned char *, void *), 
 			   void *arg);
diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index 5316e8a..120ca21 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -14,6 +14,7 @@
 #include "skas/mm_id.h"
 #include "irq_user.h"
 #include "sysdep/tls.h"
+#include "sysdep/archsetjmp.h"
 
 #define OS_TYPE_FILE 1
 #define OS_TYPE_DIR 2
@@ -198,7 +199,9 @@ extern long os_ptrace_ldt(long pid, long addr, long data);
 extern int os_getpid(void);
 extern int os_getpgrp(void);
 
+#ifdef UML_CONFIG_MODE_TT
 extern void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int));
+#endif
 extern void init_new_thread_signals(void);
 extern int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr);
 
@@ -216,7 +219,6 @@ extern void os_flush_stdout(void);
  */
 extern void forward_ipi(int fd, int pid);
 extern void kill_child_dead(int pid);
-extern void stop(void);
 extern int wait_for_stop(int pid, int sig, int cont_type, void *relay);
 extern int protect_memory(unsigned long addr, unsigned long len,
 			  int r, int w, int x, int must_succeed);
@@ -276,9 +278,11 @@ extern int setjmp_wrapper(void (*proc)(void *, void *), ...);
 
 extern void switch_timers(int to_real);
 extern void idle_sleep(int secs);
+extern int set_interval(int is_virtual);
+#ifdef CONFIG_MODE_TT
 extern void enable_timer(void);
+#endif
 extern void disable_timer(void);
-extern void user_time_init(void);
 extern void uml_idle_timer(void);
 extern unsigned long long os_nsecs(void);
 
@@ -305,12 +309,9 @@ extern int copy_context_skas0(unsigned long stack, int pid);
 extern void userspace(union uml_pt_regs *regs);
 extern void map_stub_pages(int fd, unsigned long code,
 			   unsigned long data, unsigned long stack);
-extern void new_thread(void *stack, void **switch_buf_ptr,
-			 void **fork_buf_ptr, void (*handler)(int));
-extern void thread_wait(void *sw, void *fb);
-extern void switch_threads(void *me, void *next);
-extern int start_idle_thread(void *stack, void *switch_buf_ptr,
-			     void **fork_buf_ptr);
+extern void new_thread(void *stack, jmp_buf *buf, void (*handler)(void));
+extern void switch_threads(jmp_buf *me, jmp_buf *you);
+extern int start_idle_thread(void *stack, jmp_buf *switch_buf);
 extern void initial_thread_cb_skas(void (*proc)(void *),
 				 void *arg);
 extern void halt_skas(void);
@@ -329,6 +330,7 @@ extern void os_set_ioignore(void);
 extern void init_irq_signals(int on_sigstack);
 
 /* sigio.c */
+extern int add_sigio_fd(int fd);
 extern int ignore_sigio_fd(int fd);
 extern void maybe_sigio_broken(int fd, int read);
 
diff --git a/arch/um/include/registers.h b/arch/um/include/registers.h
index 83b688c..f845b36 100644
--- a/arch/um/include/registers.h
+++ b/arch/um/include/registers.h
@@ -7,6 +7,7 @@
 #define __REGISTERS_H
 
 #include "sysdep/ptrace.h"
+#include "sysdep/archsetjmp.h"
 
 extern void init_thread_registers(union uml_pt_regs *to);
 extern int save_fp_registers(int pid, unsigned long *fp_regs);
@@ -15,6 +16,6 @@ extern void save_registers(int pid, union uml_pt_regs *regs);
 extern void restore_registers(int pid, union uml_pt_regs *regs);
 extern void init_registers(int pid);
 extern void get_safe_registers(unsigned long * regs, unsigned long * fp_regs);
-extern void get_thread_regs(union uml_pt_regs *uml_regs, void *buffer);
+extern unsigned long get_thread_reg(int reg, jmp_buf *buf);
 
 #endif
diff --git a/arch/um/include/skas/skas.h b/arch/um/include/skas/skas.h
index 853b26f..e88926b 100644
--- a/arch/um/include/skas/skas.h
+++ b/arch/um/include/skas/skas.h
@@ -14,8 +14,7 @@ extern int proc_mm, ptrace_faultinfo, ptrace_ldt;
 extern int skas_needs_stub;
 
 extern int user_thread(unsigned long stack, int flags);
-extern void new_thread_proc(void *stack, void (*handler)(int sig));
-extern void new_thread_handler(int sig);
+extern void new_thread_handler(void);
 extern void handle_syscall(union uml_pt_regs *regs);
 extern int new_mm(unsigned long stack);
 extern void get_skas_faultinfo(int pid, struct faultinfo * fi);
diff --git a/arch/um/include/sysdep-i386/archsetjmp.h b/arch/um/include/sysdep-i386/archsetjmp.h
new file mode 100644
index 0000000..11bafab
--- /dev/null
+++ b/arch/um/include/sysdep-i386/archsetjmp.h
@@ -0,0 +1,22 @@
+/*
+ * arch/i386/include/klibc/archsetjmp.h
+ */
+
+#ifndef _KLIBC_ARCHSETJMP_H
+#define _KLIBC_ARCHSETJMP_H
+
+struct __jmp_buf {
+	unsigned int __ebx;
+	unsigned int __esp;
+	unsigned int __ebp;
+	unsigned int __esi;
+	unsigned int __edi;
+	unsigned int __eip;
+};
+
+typedef struct __jmp_buf jmp_buf[1];
+
+#define JB_IP __eip
+#define JB_SP __esp
+
+#endif				/* _SETJMP_H */
diff --git a/arch/um/include/sysdep-i386/signal.h b/arch/um/include/sysdep-i386/signal.h
deleted file mode 100644
index 07518b1..0000000
--- a/arch/um/include/sysdep-i386/signal.h
+++ /dev/null
@@ -1,27 +0,0 @@
-/*
- * Copyright (C) 2004 PathScale, Inc
- * Licensed under the GPL
- */
-
-#ifndef __I386_SIGNAL_H_
-#define __I386_SIGNAL_H_
-
-#include <signal.h>
-
-#define ARCH_SIGHDLR_PARAM int sig
-
-#define ARCH_GET_SIGCONTEXT(sc, sig) \
-	do sc = (struct sigcontext *) (&sig + 1); while(0)
-
-#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/sysdep-x86_64/archsetjmp.h b/arch/um/include/sysdep-x86_64/archsetjmp.h
new file mode 100644
index 0000000..9a5e1a6
--- /dev/null
+++ b/arch/um/include/sysdep-x86_64/archsetjmp.h
@@ -0,0 +1,24 @@
+/*
+ * arch/x86_64/include/klibc/archsetjmp.h
+ */
+
+#ifndef _KLIBC_ARCHSETJMP_H
+#define _KLIBC_ARCHSETJMP_H
+
+struct __jmp_buf {
+	unsigned long __rbx;
+	unsigned long __rsp;
+	unsigned long __rbp;
+	unsigned long __r12;
+	unsigned long __r13;
+	unsigned long __r14;
+	unsigned long __r15;
+	unsigned long __rip;
+};
+
+typedef struct __jmp_buf jmp_buf[1];
+
+#define JB_IP __rip
+#define JB_SP __rsp
+
+#endif				/* _SETJMP_H */
diff --git a/arch/um/include/sysdep-x86_64/ptrace.h b/arch/um/include/sysdep-x86_64/ptrace.h
index 8d353f0..617bb9ef 100644
--- a/arch/um/include/sysdep-x86_64/ptrace.h
+++ b/arch/um/include/sysdep-x86_64/ptrace.h
@@ -50,6 +50,21 @@
 #define HOST_FS 25
 #define HOST_GS 26
 
+/* Also defined in asm/ptrace-x86_64.h, but not in libc headers.  So, these
+ * are already defined for kernel code, but not for userspace code.
+ */
+#ifndef FS_BASE
+/* These aren't defined in ptrace.h, but exist in struct user_regs_struct,
+ * which is what x86_64 ptrace actually uses.
+ */
+#define FS_BASE (HOST_FS_BASE * sizeof(long))
+#define GS_BASE (HOST_GS_BASE * sizeof(long))
+#define DS (HOST_DS * sizeof(long))
+#define ES (HOST_ES * sizeof(long))
+#define FS (HOST_FS * sizeof(long))
+#define GS (HOST_GS * sizeof(long))
+#endif
+
 #define REGS_FS_BASE(r) ((r)[HOST_FS_BASE])
 #define REGS_GS_BASE(r) ((r)[HOST_GS_BASE])
 #define REGS_DS(r) ((r)[HOST_DS])
@@ -89,9 +104,12 @@ union uml_pt_regs {
 #endif
 #ifdef UML_CONFIG_MODE_SKAS
 	struct skas_regs {
-		/* XXX */
-		unsigned long regs[27];
-		unsigned long fp[65];
+		/* x86_64 ptrace uses sizeof(user_regs_struct) as its register
+		 * file size, while i386 uses FRAME_SIZE.  Therefore, we need
+		 * to use UM_FRAME_SIZE here instead of HOST_FRAME_SIZE.
+		 */
+		unsigned long regs[UM_FRAME_SIZE];
+		unsigned long fp[HOST_FP_SIZE];
                 struct faultinfo faultinfo;
 		long syscall;
 		int is_user;
@@ -120,11 +138,16 @@ extern int mode_tt;
 #define UPT_R14(r) __CHOOSE_MODE(SC_R14(UPT_SC(r)), REGS_R14((r)->skas.regs))
 #define UPT_R15(r) __CHOOSE_MODE(SC_R15(UPT_SC(r)), REGS_R15((r)->skas.regs))
 #define UPT_CS(r) __CHOOSE_MODE(SC_CS(UPT_SC(r)), REGS_CS((r)->skas.regs))
+#define UPT_FS_BASE(r) \
+	__CHOOSE_MODE(SC_FS_BASE(UPT_SC(r)), REGS_FS_BASE((r)->skas.regs))
 #define UPT_FS(r) __CHOOSE_MODE(SC_FS(UPT_SC(r)), REGS_FS((r)->skas.regs))
+#define UPT_GS_BASE(r) \
+	__CHOOSE_MODE(SC_GS_BASE(UPT_SC(r)), REGS_GS_BASE((r)->skas.regs))
 #define UPT_GS(r) __CHOOSE_MODE(SC_GS(UPT_SC(r)), REGS_GS((r)->skas.regs))
 #define UPT_DS(r) __CHOOSE_MODE(SC_DS(UPT_SC(r)), REGS_DS((r)->skas.regs))
 #define UPT_ES(r) __CHOOSE_MODE(SC_ES(UPT_SC(r)), REGS_ES((r)->skas.regs))
 #define UPT_CS(r) __CHOOSE_MODE(SC_CS(UPT_SC(r)), REGS_CS((r)->skas.regs))
+#define UPT_SS(r) __CHOOSE_MODE(SC_SS(UPT_SC(r)), REGS_SS((r)->skas.regs))
 #define UPT_ORIG_RAX(r) \
 	__CHOOSE_MODE((r)->tt.orig_rax, REGS_ORIG_RAX((r)->skas.regs))
 
@@ -183,6 +206,13 @@ struct syscall_args {
                 case RBP: val = UPT_RBP(regs); break; \
                 case ORIG_RAX: val = UPT_ORIG_RAX(regs); break; \
                 case CS: val = UPT_CS(regs); break; \
+                case SS: val = UPT_SS(regs); break; \
+		case FS_BASE: val = UPT_FS_BASE(regs); break; \
+                case GS_BASE: val = UPT_GS_BASE(regs); break; \
+                case DS: val = UPT_DS(regs); break; \
+                case ES: val = UPT_ES(regs); break; \
+                case FS : val = UPT_FS (regs); break; \
+		case GS: val = UPT_GS(regs); break;	    \
                 case EFLAGS: val = UPT_EFLAGS(regs); break; \
                 default :  \
                         panic("Bad register in UPT_REG : %d\n", reg);  \
@@ -214,6 +244,13 @@ struct syscall_args {
                 case RBP: UPT_RBP(regs) = __upt_val; break; \
                 case ORIG_RAX: UPT_ORIG_RAX(regs) = __upt_val; break; \
                 case CS: UPT_CS(regs) = __upt_val; break; \
+                case SS: UPT_SS(regs) = __upt_val; break; \
+                case FS_BASE: UPT_FS_BASE(regs) = __upt_val; break; \
+                case GS_BASE: UPT_GS_BASE(regs) = __upt_val; break; \
+                case DS: UPT_DS(regs) = __upt_val; break; \
+                case ES: UPT_ES(regs) = __upt_val; break; \
+                case FS: UPT_FS(regs) = __upt_val; break; \
+                case GS: UPT_GS(regs) = __upt_val; break; \
                 case EFLAGS: UPT_EFLAGS(regs) = __upt_val; break; \
                 default :  \
                         panic("Bad register in UPT_SET : %d\n", reg);  \
diff --git a/arch/um/include/sysdep-x86_64/sc.h b/arch/um/include/sysdep-x86_64/sc.h
index a160d9f..8aee45b 100644
--- a/arch/um/include/sysdep-x86_64/sc.h
+++ b/arch/um/include/sysdep-x86_64/sc.h
@@ -35,11 +35,11 @@
 #define SC_GS(sc) SC_OFFSET(sc, SC_GS)
 #define SC_EFLAGS(sc) SC_OFFSET(sc, SC_EFLAGS)
 #define SC_SIGMASK(sc) SC_OFFSET(sc, SC_SIGMASK)
+#define SC_SS(sc) SC_OFFSET(sc, SC_SS)
 #if 0
 #define SC_ORIG_RAX(sc) SC_OFFSET(sc, SC_ORIG_RAX)
 #define SC_DS(sc) SC_OFFSET(sc, SC_DS)
 #define SC_ES(sc) SC_OFFSET(sc, SC_ES)
-#define SC_SS(sc) SC_OFFSET(sc, SC_SS)
 #endif
 
 #endif
diff --git a/arch/um/include/sysdep-x86_64/signal.h b/arch/um/include/sysdep-x86_64/signal.h
deleted file mode 100644
index 6142897..0000000
--- a/arch/um/include/sysdep-x86_64/signal.h
+++ /dev/null
@@ -1,29 +0,0 @@
-/*
- * Copyright (C) 2004 PathScale, Inc
- * Licensed under the GPL
- */
-
-#ifndef __X86_64_SIGNAL_H_
-#define __X86_64_SIGNAL_H_
-
-#define ARCH_SIGHDLR_PARAM int sig
-
-#define ARCH_GET_SIGCONTEXT(sc, sig_addr) \
-	do { \
-		struct ucontext *__uc; \
-		asm("movq %%rdx, %0" : "=r" (__uc)); \
-		sc = (struct sigcontext *) &__uc->uc_mcontext; \
-	} while(0)
-
-#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/kernel/Makefile b/arch/um/kernel/Makefile
index a2d9306..6fa63a2 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_kern.o ptrace.o reboot.o resource.o sigio.o \
+	physmem.o process.o ptrace.o reboot.o resource.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 fc38a6d..0561c43 100644
--- a/arch/um/kernel/exec.c
+++ b/arch/um/kernel/exec.c
@@ -41,9 +41,11 @@ static long execve1(char *file, char __user * __user *argv,
         long error;
 
 #ifdef CONFIG_TTY_LOG
-	task_lock(current);
+	mutex_lock(&tty_mutex);
+	task_lock(current);	/* FIXME:  is this needed ? */
 	log_exec(argv, current->signal->tty);
 	task_unlock(current);
+	mutex_unlock(&tty_mutex);
 #endif
         error = do_execve(file, argv, env, &current->thread.regs);
         if (error == 0){
diff --git a/arch/um/kernel/gmon_syms.c b/arch/um/kernel/gmon_syms.c
index 2c86e7f..13aa115 100644
--- a/arch/um/kernel/gmon_syms.c
+++ b/arch/um/kernel/gmon_syms.c
@@ -5,7 +5,7 @@
 
 #include "linux/module.h"
 
-extern void __bb_init_func(void *);
+extern void __bb_init_func(void *)  __attribute__((weak));
 EXPORT_SYMBOL(__bb_init_func);
 
 /* This is defined (and referred to in profiling stub code) only by some GCC
@@ -21,14 +21,3 @@ EXPORT_SYMBOL(__gcov_init);
 
 extern void __gcov_merge_add(void *) __attribute__((weak));
 EXPORT_SYMBOL(__gcov_merge_add);
-
-/*
- * 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/irq.c b/arch/um/kernel/irq.c
index 589c69a..ce7f233 100644
--- a/arch/um/kernel/irq.c
+++ b/arch/um/kernel/irq.c
@@ -142,19 +142,6 @@ int activate_fd(int irq, int fd, int type, void *dev_id)
 				     .events 		= events,
 				     .current_events 	= 0 } );
 
-	/* Critical section - locked by a spinlock because this stuff can
-	 * be changed from interrupt handlers.  The stuff above is done
-	 * outside the lock because it allocates memory.
-	 */
-
-	/* Actually, it only looks like it can be called from interrupt
-	 * context.  The culprit is reactivate_fd, which calls
-	 * maybe_sigio_broken, which calls write_sigio_workaround,
-	 * which calls activate_fd.  However, write_sigio_workaround should
-	 * only be called once, at boot time.  That would make it clear that
-	 * this is called only from process context, and can be locked with
-	 * a semaphore.
-	 */
 	spin_lock_irqsave(&irq_lock, flags);
 	for (irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next) {
 		if ((irq_fd->fd == fd) && (irq_fd->type == type)) {
@@ -165,7 +152,6 @@ int activate_fd(int irq, int fd, int type, void *dev_id)
 		}
 	}
 
-	/*-------------*/
 	if (type == IRQ_WRITE)
 		fd = -1;
 
@@ -198,7 +184,6 @@ int activate_fd(int irq, int fd, int type, void *dev_id)
 
 		spin_lock_irqsave(&irq_lock, flags);
 	}
-	/*-------------*/
 
 	*last_irq_ptr = new_fd;
 	last_irq_ptr = &new_fd->next;
@@ -210,14 +195,14 @@ int activate_fd(int irq, int fd, int type, void *dev_id)
 	 */
 	maybe_sigio_broken(fd, (type == IRQ_READ));
 
-	return(0);
+	return 0;
 
  out_unlock:
 	spin_unlock_irqrestore(&irq_lock, flags);
  out_kfree:
 	kfree(new_fd);
  out:
-	return(err);
+	return err;
 }
 
 static void free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg)
@@ -302,10 +287,7 @@ void reactivate_fd(int fd, int irqnum)
 	os_set_pollfd(i, irq->fd);
 	spin_unlock_irqrestore(&irq_lock, flags);
 
-	/* This calls activate_fd, so it has to be outside the critical
-	 * section.
-	 */
-	maybe_sigio_broken(fd, (irq->type == IRQ_READ));
+	add_sigio_fd(fd);
 }
 
 void deactivate_fd(int fd, int irqnum)
@@ -316,11 +298,15 @@ void deactivate_fd(int fd, int irqnum)
 
 	spin_lock_irqsave(&irq_lock, flags);
 	irq = find_irq_by_fd(fd, irqnum, &i);
-	if (irq == NULL)
-		goto out;
+	if(irq == NULL){
+		spin_unlock_irqrestore(&irq_lock, flags);
+		return;
+	}
+
 	os_set_pollfd(i, -1);
- out:
 	spin_unlock_irqrestore(&irq_lock, flags);
+
+	ignore_sigio_fd(fd);
 }
 
 int deactivate_all_fds(void)
diff --git a/arch/um/kernel/ksyms.c b/arch/um/kernel/ksyms.c
index c97045d..f030e44 100644
--- a/arch/um/kernel/ksyms.c
+++ b/arch/um/kernel/ksyms.c
@@ -21,7 +21,6 @@
 #include "mem_user.h"
 #include "os.h"
 
-EXPORT_SYMBOL(stop);
 EXPORT_SYMBOL(uml_physmem);
 EXPORT_SYMBOL(set_signals);
 EXPORT_SYMBOL(get_signals);
@@ -41,12 +40,14 @@ EXPORT_SYMBOL(handle_page_fault);
 EXPORT_SYMBOL(find_iomem);
 
 #ifdef CONFIG_MODE_TT
+EXPORT_SYMBOL(stop);
 EXPORT_SYMBOL(strncpy_from_user_tt);
 EXPORT_SYMBOL(copy_from_user_tt);
 EXPORT_SYMBOL(copy_to_user_tt);
 #endif
 
 #ifdef CONFIG_MODE_SKAS
+EXPORT_SYMBOL(strnlen_user_skas);
 EXPORT_SYMBOL(strncpy_from_user_skas);
 EXPORT_SYMBOL(copy_to_user_skas);
 EXPORT_SYMBOL(copy_from_user_skas);
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index 6128016..c95855b 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -79,8 +79,10 @@ void mem_init(void)
 
 	/* this will put all low memory onto the freelists */
 	totalram_pages = free_all_bootmem();
+#ifdef CONFIG_HIGHMEM
 	totalhigh_pages = highmem >> PAGE_SHIFT;
 	totalram_pages += totalhigh_pages;
+#endif
 	num_physpages = totalram_pages;
 	max_pfn = totalram_pages;
 	printk(KERN_INFO "Memory: %luk available\n", 
@@ -221,10 +223,14 @@ void paging_init(void)
 
 	empty_zero_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
 	empty_bad_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
-	for(i=0;i<sizeof(zones_size)/sizeof(zones_size[0]);i++) 
+	for(i = 0; i < ARRAY_SIZE(zones_size); i++)
 		zones_size[i] = 0;
-	zones_size[ZONE_DMA] = (end_iomem >> PAGE_SHIFT) - (uml_physmem >> PAGE_SHIFT);
+
+	zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) -
+		(uml_physmem >> PAGE_SHIFT);
+#ifdef CONFIG_HIGHMEM
 	zones_size[ZONE_HIGHMEM] = highmem >> PAGE_SHIFT;
+#endif
 	free_area_init(zones_size);
 
 	/*
diff --git a/arch/um/kernel/process_kern.c b/arch/um/kernel/process.c
index f6a5a50..fe6c64a 100644
--- a/arch/um/kernel/process_kern.c
+++ b/arch/um/kernel/process.c
@@ -1,10 +1,9 @@
-/* 
+/*
  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
  * Copyright 2003 PathScale, Inc.
  * Licensed under the GPL
  */
 
-#include "linux/config.h"
 #include "linux/kernel.h"
 #include "linux/sched.h"
 #include "linux/interrupt.h"
@@ -23,6 +22,7 @@
 #include "linux/proc_fs.h"
 #include "linux/ptrace.h"
 #include "linux/random.h"
+#include "linux/personality.h"
 #include "asm/unistd.h"
 #include "asm/mman.h"
 #include "asm/segment.h"
@@ -112,11 +112,11 @@ void set_current(void *t)
 
 void *_switch_to(void *prev, void *next, void *last)
 {
-        struct task_struct *from = prev;
-        struct task_struct *to= next;
+	struct task_struct *from = prev;
+	struct task_struct *to= next;
 
-        to->thread.prev_sched = from;
-        set_current(to);
+	to->thread.prev_sched = from;
+	set_current(to);
 
 	do {
 		current->thread.saved_task = NULL ;
@@ -127,7 +127,7 @@ void *_switch_to(void *prev, void *next, void *last)
 		prev= current;
 	} while(current->thread.saved_task);
 
-        return(current->thread.prev_sched);
+	return(current->thread.prev_sched);
 
 }
 
@@ -141,19 +141,19 @@ void release_thread(struct task_struct *task)
 {
 	CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
 }
- 
+
 void exit_thread(void)
 {
 	unprotect_stack((unsigned long) current_thread);
 }
- 
+
 void *get_current(void)
 {
 	return(current);
 }
 
 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
-		unsigned long stack_top, struct task_struct * p, 
+		unsigned long stack_top, struct task_struct * p,
 		struct pt_regs *regs)
 {
 	int ret;
@@ -182,11 +182,11 @@ void initial_thread_cb(void (*proc)(void *), void *arg)
 	int save_kmalloc_ok = kmalloc_ok;
 
 	kmalloc_ok = 0;
-	CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc, 
+	CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc,
 			 arg);
 	kmalloc_ok = save_kmalloc_ok;
 }
- 
+
 unsigned long stack_sp(unsigned long page)
 {
 	return(page + PAGE_SIZE - sizeof(void *));
@@ -210,7 +210,7 @@ void default_idle(void)
 		 */
 		if(need_resched())
 			schedule();
-		
+
 		idle_sleep(10);
 	}
 }
@@ -225,7 +225,7 @@ int page_size(void)
 	return(PAGE_SIZE);
 }
 
-void *um_virt_to_phys(struct task_struct *task, unsigned long addr, 
+void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
 		      pte_t *pte_out)
 {
 	pgd_t *pgd;
@@ -234,7 +234,7 @@ void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
 	pte_t *pte;
 	pte_t ptent;
 
-	if(task->mm == NULL) 
+	if(task->mm == NULL)
 		return(ERR_PTR(-EINVAL));
 	pgd = pgd_offset(task->mm, addr);
 	if(!pgd_present(*pgd))
@@ -245,7 +245,7 @@ void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
 		return(ERR_PTR(-EINVAL));
 
 	pmd = pmd_offset(pud, addr);
-	if(!pmd_present(*pmd)) 
+	if(!pmd_present(*pmd))
 		return(ERR_PTR(-EINVAL));
 
 	pte = pte_offset_kernel(pmd, addr);
@@ -270,7 +270,7 @@ char *current_cmd(void)
 
 void force_sigbus(void)
 {
-	printk(KERN_ERR "Killing pid %d because of a lack of memory\n", 
+	printk(KERN_ERR "Killing pid %d because of a lack of memory\n",
 	       current->pid);
 	lock_kernel();
 	sigaddset(&current->pending.signal, SIGBUS);
@@ -476,7 +476,7 @@ int singlestepping(void * t)
 #ifndef arch_align_stack
 unsigned long arch_align_stack(unsigned long sp)
 {
-	if (randomize_va_space)
+	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
 		sp -= get_random_int() % 8192;
 	return sp & ~0xf;
 }
diff --git a/arch/um/kernel/reboot.c b/arch/um/kernel/reboot.c
index 3ef73bf..f602623 100644
--- a/arch/um/kernel/reboot.c
+++ b/arch/um/kernel/reboot.c
@@ -22,7 +22,7 @@ static void kill_idlers(int me)
 	struct task_struct *p;
 	int i;
 
-	for(i = 0; i < sizeof(idle_threads)/sizeof(idle_threads[0]); i++){
+	for(i = 0; i < ARRAY_SIZE(idle_threads); i++){
 		p = idle_threads[i];
 		if((p != NULL) && (p->thread.mode.tt.extern_pid != me))
 			os_kill_process(p->thread.mode.tt.extern_pid, 0);
@@ -62,14 +62,3 @@ void machine_halt(void)
 {
 	machine_power_off();
 }
-
-/*
- * 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/skas/Makefile b/arch/um/kernel/skas/Makefile
index ea3a8e4..3e3fa7e 100644
--- a/arch/um/kernel/skas/Makefile
+++ b/arch/um/kernel/skas/Makefile
@@ -3,8 +3,7 @@
 # Licensed under the GPL
 #
 
-obj-y := clone.o exec_kern.o mem.o mmu.o process_kern.o \
-	syscall.o tlb.o uaccess.o
+obj-y := clone.o exec.o mem.o mmu.o process.o syscall.o tlb.o uaccess.o
 
 # clone.o is in the stub, so it can't be built with profiling
 # GCC hardened also auto-enables -fpic, but we need %ebx so it can't work ->
diff --git a/arch/um/kernel/skas/exec.c b/arch/um/kernel/skas/exec.c
new file mode 100644
index 0000000..54b7959
--- /dev/null
+++ b/arch/um/kernel/skas/exec.c
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include "linux/kernel.h"
+#include "asm/current.h"
+#include "asm/page.h"
+#include "asm/signal.h"
+#include "asm/ptrace.h"
+#include "asm/uaccess.h"
+#include "asm/mmu_context.h"
+#include "tlb.h"
+#include "skas.h"
+#include "um_mmu.h"
+#include "os.h"
+
+void flush_thread_skas(void)
+{
+	force_flush_all();
+	switch_mm_skas(&current->mm->context.skas.id);
+}
+
+void start_thread_skas(struct pt_regs *regs, unsigned long eip,
+		       unsigned long esp)
+{
+	set_fs(USER_DS);
+	PT_REGS_IP(regs) = eip;
+	PT_REGS_SP(regs) = esp;
+}
diff --git a/arch/um/kernel/skas/exec_kern.c b/arch/um/kernel/skas/exec_kern.c
deleted file mode 100644
index 77ed7bb..0000000
--- a/arch/um/kernel/skas/exec_kern.c
+++ /dev/null
@@ -1,41 +0,0 @@
-/* 
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#include "linux/kernel.h"
-#include "asm/current.h"
-#include "asm/page.h"
-#include "asm/signal.h"
-#include "asm/ptrace.h"
-#include "asm/uaccess.h"
-#include "asm/mmu_context.h"
-#include "tlb.h"
-#include "skas.h"
-#include "um_mmu.h"
-#include "os.h"
-
-void flush_thread_skas(void)
-{
-	force_flush_all();
-        switch_mm_skas(&current->mm->context.skas.id);
-}
-
-void start_thread_skas(struct pt_regs *regs, unsigned long eip, 
-		       unsigned long esp)
-{
-	set_fs(USER_DS);
-        PT_REGS_IP(regs) = eip;
-	PT_REGS_SP(regs) = esp;
-}
-
-/*
- * 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/skas/mmu.c b/arch/um/kernel/skas/mmu.c
index 624ca23..79c2270 100644
--- a/arch/um/kernel/skas/mmu.c
+++ b/arch/um/kernel/skas/mmu.c
@@ -55,7 +55,7 @@ static int init_stub_pte(struct mm_struct *mm, unsigned long proc,
 	 * destroy_context_skas.
 	 */
 
-        mm->context.skas.last_page_table = pmd_page_kernel(*pmd);
+        mm->context.skas.last_page_table = pmd_page_vaddr(*pmd);
 #ifdef CONFIG_3_LEVEL_PGTABLES
         mm->context.skas.last_pmd = (unsigned long) __va(pud_val(*pud));
 #endif
diff --git a/arch/um/kernel/skas/process.c b/arch/um/kernel/skas/process.c
new file mode 100644
index 0000000..ae4fa71
--- /dev/null
+++ b/arch/um/kernel/skas/process.c
@@ -0,0 +1,217 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include "linux/sched.h"
+#include "linux/slab.h"
+#include "linux/ptrace.h"
+#include "linux/proc_fs.h"
+#include "linux/file.h"
+#include "linux/errno.h"
+#include "linux/init.h"
+#include "asm/uaccess.h"
+#include "asm/atomic.h"
+#include "kern_util.h"
+#include "skas.h"
+#include "os.h"
+#include "user_util.h"
+#include "tlb.h"
+#include "kern.h"
+#include "mode.h"
+#include "registers.h"
+
+void switch_to_skas(void *prev, void *next)
+{
+	struct task_struct *from, *to;
+
+	from = prev;
+	to = next;
+
+	/* XXX need to check runqueues[cpu].idle */
+	if(current->pid == 0)
+		switch_timers(0);
+
+	switch_threads(&from->thread.mode.skas.switch_buf,
+		       &to->thread.mode.skas.switch_buf);
+
+	arch_switch_to_skas(current->thread.prev_sched, current);
+
+	if(current->pid == 0)
+		switch_timers(1);
+}
+
+extern void schedule_tail(struct task_struct *prev);
+
+/* This is called magically, by its address being stuffed in a jmp_buf
+ * and being longjmp-d to.
+ */
+void new_thread_handler(void)
+{
+	int (*fn)(void *), n;
+	void *arg;
+
+	if(current->thread.prev_sched != NULL)
+		schedule_tail(current->thread.prev_sched);
+	current->thread.prev_sched = NULL;
+
+	fn = current->thread.request.u.thread.proc;
+	arg = current->thread.request.u.thread.arg;
+
+	/* The return value is 1 if the kernel thread execs a process,
+	 * 0 if it just exits
+	 */
+	n = run_kernel_thread(fn, arg, &current->thread.exec_buf);
+	if(n == 1){
+		/* Handle any immediate reschedules or signals */
+		interrupt_end();
+		userspace(&current->thread.regs.regs);
+	}
+	else do_exit(0);
+}
+
+void release_thread_skas(struct task_struct *task)
+{
+}
+
+/* Called magically, see new_thread_handler above */
+void fork_handler(void)
+{
+	force_flush_all();
+	if(current->thread.prev_sched == NULL)
+		panic("blech");
+
+	schedule_tail(current->thread.prev_sched);
+
+	/* XXX: if interrupt_end() calls schedule, this call to
+	 * arch_switch_to_skas isn't needed. We could want to apply this to
+	 * improve performance. -bb */
+	arch_switch_to_skas(current->thread.prev_sched, current);
+
+	current->thread.prev_sched = NULL;
+
+/* Handle any immediate reschedules or signals */
+	interrupt_end();
+
+	userspace(&current->thread.regs.regs);
+}
+
+int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp,
+		     unsigned long stack_top, struct task_struct * p,
+		     struct pt_regs *regs)
+{
+	void (*handler)(void);
+
+	if(current->thread.forking){
+	  	memcpy(&p->thread.regs.regs.skas, &regs->regs.skas,
+		       sizeof(p->thread.regs.regs.skas));
+		REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.skas.regs, 0);
+		if(sp != 0) REGS_SP(p->thread.regs.regs.skas.regs) = sp;
+
+		handler = fork_handler;
+
+		arch_copy_thread(&current->thread.arch, &p->thread.arch);
+	}
+	else {
+		init_thread_registers(&p->thread.regs.regs);
+		p->thread.request.u.thread = current->thread.request.u.thread;
+		handler = new_thread_handler;
+	}
+
+	new_thread(task_stack_page(p), &p->thread.mode.skas.switch_buf,
+		   handler);
+	return(0);
+}
+
+int new_mm(unsigned long stack)
+{
+	int fd;
+
+	fd = os_open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0);
+	if(fd < 0)
+		return(fd);
+
+	if(skas_needs_stub)
+		map_stub_pages(fd, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack);
+
+	return(fd);
+}
+
+void init_idle_skas(void)
+{
+	cpu_tasks[current_thread->cpu].pid = os_getpid();
+	default_idle();
+}
+
+extern void start_kernel(void);
+
+static int start_kernel_proc(void *unused)
+{
+	int pid;
+
+	block_signals();
+	pid = os_getpid();
+
+	cpu_tasks[0].pid = pid;
+	cpu_tasks[0].task = current;
+#ifdef CONFIG_SMP
+	cpu_online_map = cpumask_of_cpu(0);
+#endif
+	start_kernel();
+	return(0);
+}
+
+extern int userspace_pid[];
+
+int start_uml_skas(void)
+{
+	if(proc_mm)
+		userspace_pid[0] = start_userspace(0);
+
+	init_new_thread_signals();
+
+	init_task.thread.request.u.thread.proc = start_kernel_proc;
+	init_task.thread.request.u.thread.arg = NULL;
+	return(start_idle_thread(task_stack_page(&init_task),
+				 &init_task.thread.mode.skas.switch_buf));
+}
+
+int external_pid_skas(struct task_struct *task)
+{
+#warning Need to look up userspace_pid by cpu
+	return(userspace_pid[0]);
+}
+
+int thread_pid_skas(struct task_struct *task)
+{
+#warning Need to look up userspace_pid by cpu
+	return(userspace_pid[0]);
+}
+
+void kill_off_processes_skas(void)
+{
+	if(proc_mm)
+#warning need to loop over userspace_pids in kill_off_processes_skas
+		os_kill_ptraced_process(userspace_pid[0], 1);
+	else {
+		struct task_struct *p;
+		int pid, me;
+
+		me = os_getpid();
+		for_each_process(p){
+			if(p->mm == NULL)
+				continue;
+
+			pid = p->mm->context.skas.id.u.pid;
+			os_kill_ptraced_process(pid, 1);
+		}
+	}
+}
+
+unsigned long current_stub_stack(void)
+{
+	if(current->mm == NULL)
+		return(0);
+
+	return(current->mm->context.skas.id.stack);
+}
diff --git a/arch/um/kernel/skas/process_kern.c b/arch/um/kernel/skas/process_kern.c
index 55caeec..0f3d5d0 100644
--- a/arch/um/kernel/skas/process_kern.c
+++ b/arch/um/kernel/skas/process_kern.c
@@ -1,227 +1,484 @@
 /*
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright 2003 PathScale, Inc.
  * Licensed under the GPL
  */
 
+#include "linux/config.h"
+#include "linux/kernel.h"
 #include "linux/sched.h"
+#include "linux/interrupt.h"
+#include "linux/string.h"
+#include "linux/mm.h"
 #include "linux/slab.h"
-#include "linux/ptrace.h"
-#include "linux/proc_fs.h"
-#include "linux/file.h"
-#include "linux/errno.h"
+#include "linux/utsname.h"
+#include "linux/fs.h"
+#include "linux/utime.h"
+#include "linux/smp_lock.h"
+#include "linux/module.h"
 #include "linux/init.h"
+#include "linux/capability.h"
+#include "linux/vmalloc.h"
+#include "linux/spinlock.h"
+#include "linux/proc_fs.h"
+#include "linux/ptrace.h"
+#include "linux/random.h"
+#include "linux/personality.h"
+#include "asm/unistd.h"
+#include "asm/mman.h"
+#include "asm/segment.h"
+#include "asm/stat.h"
+#include "asm/pgtable.h"
+#include "asm/processor.h"
+#include "asm/tlbflush.h"
 #include "asm/uaccess.h"
-#include "asm/atomic.h"
-#include "kern_util.h"
-#include "skas.h"
-#include "os.h"
+#include "asm/user.h"
 #include "user_util.h"
-#include "tlb.h"
+#include "kern_util.h"
 #include "kern.h"
+#include "signal_kern.h"
+#include "init.h"
+#include "irq_user.h"
+#include "mem_user.h"
+#include "tlb.h"
+#include "frame_kern.h"
+#include "sigcontext.h"
+#include "os.h"
 #include "mode.h"
-#include "registers.h"
+#include "mode_kern.h"
+#include "choose-mode.h"
+
+/* This is a per-cpu array.  A processor only modifies its entry and it only
+ * cares about its entry, so it's OK if another processor is modifying its
+ * entry.
+ */
+struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
+
+int external_pid(void *t)
+{
+	struct task_struct *task = t ? t : current;
+
+	return(CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task));
+}
+
+int pid_to_processor_id(int pid)
+{
+	int i;
+
+	for(i = 0; i < ncpus; i++){
+		if(cpu_tasks[i].pid == pid) return(i);
+	}
+	return(-1);
+}
+
+void free_stack(unsigned long stack, int order)
+{
+	free_pages(stack, order);
+}
+
+unsigned long alloc_stack(int order, int atomic)
+{
+	unsigned long page;
+	gfp_t flags = GFP_KERNEL;
+
+	if (atomic)
+		flags = GFP_ATOMIC;
+	page = __get_free_pages(flags, order);
+	if(page == 0)
+		return(0);
+	stack_protections(page);
+	return(page);
+}
+
+int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
+{
+	int pid;
+
+	current->thread.request.u.thread.proc = fn;
+	current->thread.request.u.thread.arg = arg;
+	pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0,
+		      &current->thread.regs, 0, NULL, NULL);
+	if(pid < 0)
+		panic("do_fork failed in kernel_thread, errno = %d", pid);
+	return(pid);
+}
 
-void switch_to_skas(void *prev, void *next)
+void set_current(void *t)
 {
-	struct task_struct *from, *to;
+	struct task_struct *task = t;
 
-	from = prev;
-	to = next;
+	cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
+		{ external_pid(task), task });
+}
 
-	/* XXX need to check runqueues[cpu].idle */
-	if(current->pid == 0)
-		switch_timers(0);
+void *_switch_to(void *prev, void *next, void *last)
+{
+        struct task_struct *from = prev;
+        struct task_struct *to= next;
 
-	switch_threads(&from->thread.mode.skas.switch_buf,
-		       to->thread.mode.skas.switch_buf);
+        to->thread.prev_sched = from;
+        set_current(to);
 
-	arch_switch_to_skas(current->thread.prev_sched, current);
+	do {
+		current->thread.saved_task = NULL ;
+		CHOOSE_MODE_PROC(switch_to_tt, switch_to_skas, prev, next);
+		if(current->thread.saved_task)
+			show_regs(&(current->thread.regs));
+		next= current->thread.saved_task;
+		prev= current;
+	} while(current->thread.saved_task);
+
+        return(current->thread.prev_sched);
 
-	if(current->pid == 0)
-		switch_timers(1);
 }
 
-extern void schedule_tail(struct task_struct *prev);
+void interrupt_end(void)
+{
+	if(need_resched()) schedule();
+	if(test_tsk_thread_flag(current, TIF_SIGPENDING)) do_signal();
+}
 
-void new_thread_handler(int sig)
+void release_thread(struct task_struct *task)
 {
-	int (*fn)(void *), n;
-	void *arg;
+	CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
+}
 
-	fn = current->thread.request.u.thread.proc;
-	arg = current->thread.request.u.thread.arg;
-	os_usr1_signal(1);
-	thread_wait(&current->thread.mode.skas.switch_buf,
-		    current->thread.mode.skas.fork_buf);
+void exit_thread(void)
+{
+	unprotect_stack((unsigned long) current_thread);
+}
 
-	if(current->thread.prev_sched != NULL)
-		schedule_tail(current->thread.prev_sched);
-	current->thread.prev_sched = NULL;
+void *get_current(void)
+{
+	return(current);
+}
+
+int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
+		unsigned long stack_top, struct task_struct * p,
+		struct pt_regs *regs)
+{
+	int ret;
 
-	/* The return value is 1 if the kernel thread execs a process,
-	 * 0 if it just exits
+	p->thread = (struct thread_struct) INIT_THREAD;
+	ret = CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr,
+				clone_flags, sp, stack_top, p, regs);
+
+	if (ret || !current->thread.forking)
+		goto out;
+
+	clear_flushed_tls(p);
+
+	/*
+	 * Set a new TLS for the child thread?
 	 */
-	n = run_kernel_thread(fn, arg, &current->thread.exec_buf);
-	if(n == 1){
-		/* Handle any immediate reschedules or signals */
-		interrupt_end();
-		userspace(&current->thread.regs.regs);
+	if (clone_flags & CLONE_SETTLS)
+		ret = arch_copy_tls(p);
+
+out:
+	return ret;
+}
+
+void initial_thread_cb(void (*proc)(void *), void *arg)
+{
+	int save_kmalloc_ok = kmalloc_ok;
+
+	kmalloc_ok = 0;
+	CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc,
+			 arg);
+	kmalloc_ok = save_kmalloc_ok;
+}
+
+unsigned long stack_sp(unsigned long page)
+{
+	return(page + PAGE_SIZE - sizeof(void *));
+}
+
+int current_pid(void)
+{
+	return(current->pid);
+}
+
+void default_idle(void)
+{
+	CHOOSE_MODE(uml_idle_timer(), (void) 0);
+
+	while(1){
+		/* endless idle loop with no priority at all */
+
+		/*
+		 * although we are an idle CPU, we do not want to
+		 * get into the scheduler unnecessarily.
+		 */
+		if(need_resched())
+			schedule();
+
+		idle_sleep(10);
 	}
-	else do_exit(0);
 }
 
-void new_thread_proc(void *stack, void (*handler)(int sig))
+void cpu_idle(void)
 {
-	init_new_thread_stack(stack, handler);
-	os_usr1_process(os_getpid());
+	CHOOSE_MODE(init_idle_tt(), init_idle_skas());
 }
 
-void release_thread_skas(struct task_struct *task)
+int page_size(void)
 {
+	return(PAGE_SIZE);
 }
 
-void fork_handler(int sig)
+void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
+		      pte_t *pte_out)
 {
-	os_usr1_signal(1);
-	thread_wait(&current->thread.mode.skas.switch_buf,
-		    current->thread.mode.skas.fork_buf);
-  	
-	force_flush_all();
-	if(current->thread.prev_sched == NULL)
-		panic("blech");
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
+	pte_t ptent;
+
+	if(task->mm == NULL)
+		return(ERR_PTR(-EINVAL));
+	pgd = pgd_offset(task->mm, addr);
+	if(!pgd_present(*pgd))
+		return(ERR_PTR(-EINVAL));
+
+	pud = pud_offset(pgd, addr);
+	if(!pud_present(*pud))
+		return(ERR_PTR(-EINVAL));
+
+	pmd = pmd_offset(pud, addr);
+	if(!pmd_present(*pmd))
+		return(ERR_PTR(-EINVAL));
+
+	pte = pte_offset_kernel(pmd, addr);
+	ptent = *pte;
+	if(!pte_present(ptent))
+		return(ERR_PTR(-EINVAL));
+
+	if(pte_out != NULL)
+		*pte_out = ptent;
+	return((void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK));
+}
 
-	schedule_tail(current->thread.prev_sched);
+char *current_cmd(void)
+{
+#if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
+	return("(Unknown)");
+#else
+	void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
+	return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
+#endif
+}
 
-	/* XXX: if interrupt_end() calls schedule, this call to
-	 * arch_switch_to_skas isn't needed. We could want to apply this to
-	 * improve performance. -bb */
-	arch_switch_to_skas(current->thread.prev_sched, current);
+void force_sigbus(void)
+{
+	printk(KERN_ERR "Killing pid %d because of a lack of memory\n",
+	       current->pid);
+	lock_kernel();
+	sigaddset(&current->pending.signal, SIGBUS);
+	recalc_sigpending();
+	current->flags |= PF_SIGNALED;
+	do_exit(SIGBUS | 0x80);
+}
 
-	current->thread.prev_sched = NULL;
+void dump_thread(struct pt_regs *regs, struct user *u)
+{
+}
 
-/* Handle any immediate reschedules or signals */
-	interrupt_end();
+void enable_hlt(void)
+{
+	panic("enable_hlt");
+}
+
+EXPORT_SYMBOL(enable_hlt);
 
-	userspace(&current->thread.regs.regs);
+void disable_hlt(void)
+{
+	panic("disable_hlt");
 }
 
-int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp,
-		     unsigned long stack_top, struct task_struct * p,
-		     struct pt_regs *regs)
+EXPORT_SYMBOL(disable_hlt);
+
+void *um_kmalloc(int size)
 {
-  	void (*handler)(int);
+	return kmalloc(size, GFP_KERNEL);
+}
 
-	if(current->thread.forking){
-	  	memcpy(&p->thread.regs.regs.skas, &regs->regs.skas,
-		       sizeof(p->thread.regs.regs.skas));
-		REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.skas.regs, 0);
-		if(sp != 0) REGS_SP(p->thread.regs.regs.skas.regs) = sp;
+void *um_kmalloc_atomic(int size)
+{
+	return kmalloc(size, GFP_ATOMIC);
+}
 
-		handler = fork_handler;
+void *um_vmalloc(int size)
+{
+	return vmalloc(size);
+}
 
-		arch_copy_thread(&current->thread.arch, &p->thread.arch);
-	}
-	else {
-		init_thread_registers(&p->thread.regs.regs);
-                p->thread.request.u.thread = current->thread.request.u.thread;
-		handler = new_thread_handler;
-	}
+void *um_vmalloc_atomic(int size)
+{
+	return __vmalloc(size, GFP_ATOMIC | __GFP_HIGHMEM, PAGE_KERNEL);
+}
 
-	new_thread(task_stack_page(p), &p->thread.mode.skas.switch_buf,
-		   &p->thread.mode.skas.fork_buf, handler);
-	return(0);
+int __cant_sleep(void) {
+	return in_atomic() || irqs_disabled() || in_interrupt();
+	/* Is in_interrupt() really needed? */
+}
+
+unsigned long get_fault_addr(void)
+{
+	return((unsigned long) current->thread.fault_addr);
 }
 
-int new_mm(unsigned long stack)
+EXPORT_SYMBOL(get_fault_addr);
+
+void not_implemented(void)
 {
-	int fd;
+	printk(KERN_DEBUG "Something isn't implemented in here\n");
+}
 
-	fd = os_open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0);
-	if(fd < 0)
-		return(fd);
+EXPORT_SYMBOL(not_implemented);
 
-	if(skas_needs_stub)
-		map_stub_pages(fd, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack);
+int user_context(unsigned long sp)
+{
+	unsigned long stack;
 
-	return(fd);
+	stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
+	return(stack != (unsigned long) current_thread);
 }
 
-void init_idle_skas(void)
+extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
+
+void do_uml_exitcalls(void)
 {
-	cpu_tasks[current_thread->cpu].pid = os_getpid();
-	default_idle();
+	exitcall_t *call;
+
+	call = &__uml_exitcall_end;
+	while (--call >= &__uml_exitcall_begin)
+		(*call)();
 }
 
-extern void start_kernel(void);
+char *uml_strdup(char *string)
+{
+	return kstrdup(string, GFP_KERNEL);
+}
 
-static int start_kernel_proc(void *unused)
+int copy_to_user_proc(void __user *to, void *from, int size)
 {
-	int pid;
+	return(copy_to_user(to, from, size));
+}
+
+int copy_from_user_proc(void *to, void __user *from, int size)
+{
+	return(copy_from_user(to, from, size));
+}
+
+int clear_user_proc(void __user *buf, int size)
+{
+	return(clear_user(buf, size));
+}
 
-	block_signals();
-	pid = os_getpid();
+int strlen_user_proc(char __user *str)
+{
+	return(strlen_user(str));
+}
 
-	cpu_tasks[0].pid = pid;
-	cpu_tasks[0].task = current;
+int smp_sigio_handler(void)
+{
 #ifdef CONFIG_SMP
- 	cpu_online_map = cpumask_of_cpu(0);
+	int cpu = current_thread->cpu;
+	IPI_handler(cpu);
+	if(cpu != 0)
+		return(1);
 #endif
-	start_kernel();
 	return(0);
 }
 
-extern int userspace_pid[];
-
-int start_uml_skas(void)
+int cpu(void)
 {
-	if(proc_mm)
-		userspace_pid[0] = start_userspace(0);
+	return(current_thread->cpu);
+}
+
+static atomic_t using_sysemu = ATOMIC_INIT(0);
+int sysemu_supported;
 
-	init_new_thread_signals();
+void set_using_sysemu(int value)
+{
+	if (value > sysemu_supported)
+		return;
+	atomic_set(&using_sysemu, value);
+}
 
-	init_task.thread.request.u.thread.proc = start_kernel_proc;
-	init_task.thread.request.u.thread.arg = NULL;
-	return(start_idle_thread(task_stack_page(&init_task),
-				 &init_task.thread.mode.skas.switch_buf,
-				 &init_task.thread.mode.skas.fork_buf));
+int get_using_sysemu(void)
+{
+	return atomic_read(&using_sysemu);
 }
 
-int external_pid_skas(struct task_struct *task)
+static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
 {
-#warning Need to look up userspace_pid by cpu
-	return(userspace_pid[0]);
+	if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
+		*eof = 1;
+
+	return strlen(buf);
 }
 
-int thread_pid_skas(struct task_struct *task)
+static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned long count,void *data)
 {
-#warning Need to look up userspace_pid by cpu
-	return(userspace_pid[0]);
+	char tmp[2];
+
+	if (copy_from_user(tmp, buf, 1))
+		return -EFAULT;
+
+	if (tmp[0] >= '0' && tmp[0] <= '2')
+		set_using_sysemu(tmp[0] - '0');
+	return count; /*We use the first char, but pretend to write everything*/
 }
 
-void kill_off_processes_skas(void)
+int __init make_proc_sysemu(void)
 {
-	if(proc_mm)
-#warning need to loop over userspace_pids in kill_off_processes_skas
-		os_kill_ptraced_process(userspace_pid[0], 1);
-	else {
-		struct task_struct *p;
-		int pid, me;
+	struct proc_dir_entry *ent;
+	if (!sysemu_supported)
+		return 0;
 
-		me = os_getpid();
-		for_each_process(p){
-			if(p->mm == NULL)
-				continue;
+	ent = create_proc_entry("sysemu", 0600, &proc_root);
 
-			pid = p->mm->context.skas.id.u.pid;
-			os_kill_ptraced_process(pid, 1);
-		}
+	if (ent == NULL)
+	{
+		printk(KERN_WARNING "Failed to register /proc/sysemu\n");
+		return(0);
 	}
+
+	ent->read_proc  = proc_read_sysemu;
+	ent->write_proc = proc_write_sysemu;
+
+	return 0;
 }
 
-unsigned long current_stub_stack(void)
+late_initcall(make_proc_sysemu);
+
+int singlestepping(void * t)
 {
-	if(current->mm == NULL)
+	struct task_struct *task = t ? t : current;
+
+	if ( ! (task->ptrace & PT_DTRACE) )
 		return(0);
 
-	return(current->mm->context.skas.id.stack);
+	if (task->thread.singlestep_syscall)
+		return(1);
+
+	return 2;
+}
+
+/*
+ * Only x86 and x86_64 have an arch_align_stack().
+ * All other arches have "#define arch_align_stack(x) (x)"
+ * in their asm/system.h
+ * As this is included in UML from asm-um/system-generic.h,
+ * we can use it to behave as the subarch does.
+ */
+#ifndef arch_align_stack
+unsigned long arch_align_stack(unsigned long sp)
+{
+	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
+		sp -= get_random_int() % 8192;
+	return sp & ~0xf;
 }
+#endif
diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c
index 552ca1c..820affb 100644
--- a/arch/um/kernel/time.c
+++ b/arch/um/kernel/time.c
@@ -35,9 +35,6 @@ unsigned long long sched_clock(void)
 	return (unsigned long long)jiffies_64 * (1000000000 / HZ);
 }
 
-/* Changed at early boot */
-int timer_irq_inited = 0;
-
 static unsigned long long prev_nsecs;
 #ifdef CONFIG_UML_REAL_TIME_CLOCK
 static long long delta;   		/* Deviation per interval */
@@ -98,7 +95,7 @@ irqreturn_t um_timer(int irq, void *dev, struct pt_regs *regs)
 
 	do_timer(regs);
 
-	nsecs = get_time() + local_offset;
+	nsecs = get_time();
 	xtime.tv_sec = nsecs / NSEC_PER_SEC;
 	xtime.tv_nsec = nsecs - xtime.tv_sec * NSEC_PER_SEC;
 
@@ -113,12 +110,13 @@ static void register_timer(void)
 
 	err = request_irq(TIMER_IRQ, um_timer, IRQF_DISABLED, "timer", NULL);
 	if(err != 0)
-		printk(KERN_ERR "timer_init : request_irq failed - "
+		printk(KERN_ERR "register_timer : request_irq failed - "
 		       "errno = %d\n", -err);
 
-	timer_irq_inited = 1;
-
-	user_time_init();
+	err = set_interval(1);
+	if(err != 0)
+		printk(KERN_ERR "register_timer : set_interval failed - "
+		       "errno = %d\n", -err);
 }
 
 extern void (*late_time_init)(void);
diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c
index f5b0636..54a5ff2 100644
--- a/arch/um/kernel/tlb.c
+++ b/arch/um/kernel/tlb.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -16,12 +16,12 @@
 #include "os.h"
 
 static int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
- 		    int r, int w, int x, struct host_vm_op *ops, int *index,
+		    int r, int w, int x, struct host_vm_op *ops, int *index,
 		    int last_filled, union mm_context *mmu, void **flush,
 		    int (*do_ops)(union mm_context *, struct host_vm_op *,
 				  int, int, void **))
 {
-        __u64 offset;
+	__u64 offset;
 	struct host_vm_op *last;
 	int fd, ret = 0;
 
@@ -89,7 +89,7 @@ static int add_munmap(unsigned long addr, unsigned long len,
 static int add_mprotect(unsigned long addr, unsigned long len, int r, int w,
 			int x, struct host_vm_op *ops, int *index,
 			int last_filled, union mm_context *mmu, void **flush,
- 			int (*do_ops)(union mm_context *, struct host_vm_op *,
+			int (*do_ops)(union mm_context *, struct host_vm_op *,
 				      int, int, void **))
 {
 	struct host_vm_op *last;
@@ -124,105 +124,105 @@ static int add_mprotect(unsigned long addr, unsigned long len, int r, int w,
 #define ADD_ROUND(n, inc) (((n) + (inc)) & ~((inc) - 1))
 
 void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
-                      unsigned long end_addr, int force,
+		      unsigned long end_addr, int force,
 		      int (*do_ops)(union mm_context *, struct host_vm_op *,
 				    int, int, void **))
 {
-        pgd_t *npgd;
-        pud_t *npud;
-        pmd_t *npmd;
-        pte_t *npte;
-        union mm_context *mmu = &mm->context;
-        unsigned long addr, end;
-        int r, w, x;
-        struct host_vm_op ops[1];
-        void *flush = NULL;
-        int op_index = -1, last_op = sizeof(ops) / sizeof(ops[0]) - 1;
-        int ret = 0;
-
-        if(mm == NULL) return;
-
-        ops[0].type = NONE;
-        for(addr = start_addr; addr < end_addr && !ret;){
-                npgd = pgd_offset(mm, addr);
-                if(!pgd_present(*npgd)){
-                        end = ADD_ROUND(addr, PGDIR_SIZE);
-                        if(end > end_addr)
-                                end = end_addr;
-                        if(force || pgd_newpage(*npgd)){
-                                ret = add_munmap(addr, end - addr, ops,
-                                                 &op_index, last_op, mmu,
-                                                 &flush, do_ops);
-                                pgd_mkuptodate(*npgd);
-                        }
-                        addr = end;
-                        continue;
-                }
-
-                npud = pud_offset(npgd, addr);
-                if(!pud_present(*npud)){
-                        end = ADD_ROUND(addr, PUD_SIZE);
-                        if(end > end_addr)
-                                end = end_addr;
-                        if(force || pud_newpage(*npud)){
-                                ret = add_munmap(addr, end - addr, ops,
-                                                 &op_index, last_op, mmu,
-                                                 &flush, do_ops);
-                                pud_mkuptodate(*npud);
-                        }
-                        addr = end;
-                        continue;
-                }
-
-                npmd = pmd_offset(npud, addr);
-                if(!pmd_present(*npmd)){
-                        end = ADD_ROUND(addr, PMD_SIZE);
-                        if(end > end_addr)
-                                end = end_addr;
-                        if(force || pmd_newpage(*npmd)){
-                                ret = add_munmap(addr, end - addr, ops,
-                                                 &op_index, last_op, mmu,
-                                                 &flush, do_ops);
-                                pmd_mkuptodate(*npmd);
-                        }
-                        addr = end;
-                        continue;
-                }
-
-                npte = pte_offset_kernel(npmd, addr);
-                r = pte_read(*npte);
-                w = pte_write(*npte);
-                x = pte_exec(*npte);
+	pgd_t *npgd;
+	pud_t *npud;
+	pmd_t *npmd;
+	pte_t *npte;
+	union mm_context *mmu = &mm->context;
+	unsigned long addr, end;
+	int r, w, x;
+	struct host_vm_op ops[1];
+	void *flush = NULL;
+	int op_index = -1, last_op = ARRAY_SIZE(ops) - 1;
+	int ret = 0;
+
+	if(mm == NULL)
+		return;
+
+	ops[0].type = NONE;
+	for(addr = start_addr; addr < end_addr && !ret;){
+		npgd = pgd_offset(mm, addr);
+		if(!pgd_present(*npgd)){
+			end = ADD_ROUND(addr, PGDIR_SIZE);
+			if(end > end_addr)
+				end = end_addr;
+			if(force || pgd_newpage(*npgd)){
+				ret = add_munmap(addr, end - addr, ops,
+						 &op_index, last_op, mmu,
+						 &flush, do_ops);
+				pgd_mkuptodate(*npgd);
+			}
+			addr = end;
+			continue;
+		}
+
+		npud = pud_offset(npgd, addr);
+		if(!pud_present(*npud)){
+			end = ADD_ROUND(addr, PUD_SIZE);
+			if(end > end_addr)
+				end = end_addr;
+			if(force || pud_newpage(*npud)){
+				ret = add_munmap(addr, end - addr, ops,
+						 &op_index, last_op, mmu,
+						 &flush, do_ops);
+				pud_mkuptodate(*npud);
+			}
+			addr = end;
+			continue;
+		}
+
+		npmd = pmd_offset(npud, addr);
+		if(!pmd_present(*npmd)){
+			end = ADD_ROUND(addr, PMD_SIZE);
+			if(end > end_addr)
+				end = end_addr;
+			if(force || pmd_newpage(*npmd)){
+				ret = add_munmap(addr, end - addr, ops,
+						 &op_index, last_op, mmu,
+						 &flush, do_ops);
+				pmd_mkuptodate(*npmd);
+			}
+			addr = end;
+			continue;
+		}
+
+		npte = pte_offset_kernel(npmd, addr);
+		r = pte_read(*npte);
+		w = pte_write(*npte);
+		x = pte_exec(*npte);
 		if (!pte_young(*npte)) {
 			r = 0;
 			w = 0;
 		} else if (!pte_dirty(*npte)) {
 			w = 0;
 		}
-                if(force || pte_newpage(*npte)){
-                        if(pte_present(*npte))
-			  ret = add_mmap(addr,
-					 pte_val(*npte) & PAGE_MASK,
-					 PAGE_SIZE, r, w, x, ops,
-					 &op_index, last_op, mmu,
-					 &flush, do_ops);
+		if(force || pte_newpage(*npte)){
+			if(pte_present(*npte))
+				ret = add_mmap(addr,
+					       pte_val(*npte) & PAGE_MASK,
+					       PAGE_SIZE, r, w, x, ops,
+					       &op_index, last_op, mmu,
+					       &flush, do_ops);
 			else ret = add_munmap(addr, PAGE_SIZE, ops,
 					      &op_index, last_op, mmu,
 					      &flush, do_ops);
-                }
-                else if(pte_newprot(*npte))
+		}
+		else if(pte_newprot(*npte))
 			ret = add_mprotect(addr, PAGE_SIZE, r, w, x, ops,
 					   &op_index, last_op, mmu,
 					   &flush, do_ops);
 
-                *npte = pte_mkuptodate(*npte);
-                addr += PAGE_SIZE;
-        }
-
+		*npte = pte_mkuptodate(*npte);
+		addr += PAGE_SIZE;
+	}
 	if(!ret)
 		ret = (*do_ops)(mmu, ops, op_index, 1, &flush);
 
-	/* This is not an else because ret is modified above */
+/* This is not an else because ret is modified above */
 	if(ret) {
 		printk("fix_range_common: failed, killing current process\n");
 		force_sig(SIGKILL, current);
@@ -231,160 +231,160 @@ void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
 
 int flush_tlb_kernel_range_common(unsigned long start, unsigned long end)
 {
-        struct mm_struct *mm;
-        pgd_t *pgd;
-        pud_t *pud;
-        pmd_t *pmd;
-        pte_t *pte;
-        unsigned long addr, last;
-        int updated = 0, err;
-
-        mm = &init_mm;
-        for(addr = start; addr < end;){
-                pgd = pgd_offset(mm, addr);
-                if(!pgd_present(*pgd)){
-                        last = ADD_ROUND(addr, PGDIR_SIZE);
-                        if(last > end)
-                                last = end;
-                        if(pgd_newpage(*pgd)){
-                                updated = 1;
-                                err = os_unmap_memory((void *) addr,
-                                                      last - addr);
-                                if(err < 0)
-                                        panic("munmap failed, errno = %d\n",
-                                              -err);
-                        }
-                        addr = last;
-                        continue;
-                }
-
-                pud = pud_offset(pgd, addr);
-                if(!pud_present(*pud)){
-                        last = ADD_ROUND(addr, PUD_SIZE);
-                        if(last > end)
-                                last = end;
-                        if(pud_newpage(*pud)){
-                                updated = 1;
-                                err = os_unmap_memory((void *) addr,
-                                                      last - addr);
-                                if(err < 0)
-                                        panic("munmap failed, errno = %d\n",
-                                              -err);
-                        }
-                        addr = last;
-                        continue;
-                }
-
-                pmd = pmd_offset(pud, addr);
-                if(!pmd_present(*pmd)){
-                        last = ADD_ROUND(addr, PMD_SIZE);
-                        if(last > end)
-                                last = end;
-                        if(pmd_newpage(*pmd)){
-                                updated = 1;
-                                err = os_unmap_memory((void *) addr,
-                                                      last - addr);
-                                if(err < 0)
-                                        panic("munmap failed, errno = %d\n",
-                                              -err);
-                        }
-                        addr = last;
-                        continue;
-                }
-
-                pte = pte_offset_kernel(pmd, addr);
-                if(!pte_present(*pte) || pte_newpage(*pte)){
-                        updated = 1;
-                        err = os_unmap_memory((void *) addr,
-                                              PAGE_SIZE);
-                        if(err < 0)
-                                panic("munmap failed, errno = %d\n",
-                                      -err);
-                        if(pte_present(*pte))
-                                map_memory(addr,
-                                           pte_val(*pte) & PAGE_MASK,
-                                           PAGE_SIZE, 1, 1, 1);
-                }
-                else if(pte_newprot(*pte)){
-                        updated = 1;
-                        os_protect_memory((void *) addr, PAGE_SIZE, 1, 1, 1);
-                }
-                addr += PAGE_SIZE;
-        }
-        return(updated);
+	struct mm_struct *mm;
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
+	unsigned long addr, last;
+	int updated = 0, err;
+
+	mm = &init_mm;
+	for(addr = start; addr < end;){
+		pgd = pgd_offset(mm, addr);
+		if(!pgd_present(*pgd)){
+			last = ADD_ROUND(addr, PGDIR_SIZE);
+			if(last > end)
+				last = end;
+			if(pgd_newpage(*pgd)){
+				updated = 1;
+				err = os_unmap_memory((void *) addr,
+						      last - addr);
+				if(err < 0)
+					panic("munmap failed, errno = %d\n",
+					      -err);
+			}
+			addr = last;
+			continue;
+		}
+
+		pud = pud_offset(pgd, addr);
+		if(!pud_present(*pud)){
+			last = ADD_ROUND(addr, PUD_SIZE);
+			if(last > end)
+				last = end;
+			if(pud_newpage(*pud)){
+				updated = 1;
+				err = os_unmap_memory((void *) addr,
+						      last - addr);
+				if(err < 0)
+					panic("munmap failed, errno = %d\n",
+					      -err);
+			}
+			addr = last;
+			continue;
+		}
+
+		pmd = pmd_offset(pud, addr);
+		if(!pmd_present(*pmd)){
+			last = ADD_ROUND(addr, PMD_SIZE);
+			if(last > end)
+				last = end;
+			if(pmd_newpage(*pmd)){
+				updated = 1;
+				err = os_unmap_memory((void *) addr,
+						      last - addr);
+				if(err < 0)
+					panic("munmap failed, errno = %d\n",
+					      -err);
+			}
+			addr = last;
+			continue;
+		}
+
+		pte = pte_offset_kernel(pmd, addr);
+		if(!pte_present(*pte) || pte_newpage(*pte)){
+			updated = 1;
+			err = os_unmap_memory((void *) addr,
+					      PAGE_SIZE);
+			if(err < 0)
+				panic("munmap failed, errno = %d\n",
+				      -err);
+			if(pte_present(*pte))
+				map_memory(addr,
+					   pte_val(*pte) & PAGE_MASK,
+					   PAGE_SIZE, 1, 1, 1);
+		}
+		else if(pte_newprot(*pte)){
+			updated = 1;
+			os_protect_memory((void *) addr, PAGE_SIZE, 1, 1, 1);
+		}
+		addr += PAGE_SIZE;
+	}
+	return(updated);
 }
 
 pgd_t *pgd_offset_proc(struct mm_struct *mm, unsigned long address)
 {
-        return(pgd_offset(mm, address));
+	return(pgd_offset(mm, address));
 }
 
 pud_t *pud_offset_proc(pgd_t *pgd, unsigned long address)
 {
-        return(pud_offset(pgd, address));
+	return(pud_offset(pgd, address));
 }
 
 pmd_t *pmd_offset_proc(pud_t *pud, unsigned long address)
 {
-        return(pmd_offset(pud, address));
+	return(pmd_offset(pud, address));
 }
 
 pte_t *pte_offset_proc(pmd_t *pmd, unsigned long address)
 {
-        return(pte_offset_kernel(pmd, address));
+	return(pte_offset_kernel(pmd, address));
 }
 
 pte_t *addr_pte(struct task_struct *task, unsigned long addr)
 {
-        pgd_t *pgd = pgd_offset(task->mm, addr);
-        pud_t *pud = pud_offset(pgd, addr);
-        pmd_t *pmd = pmd_offset(pud, addr);
+	pgd_t *pgd = pgd_offset(task->mm, addr);
+	pud_t *pud = pud_offset(pgd, addr);
+	pmd_t *pmd = pmd_offset(pud, addr);
 
-        return(pte_offset_map(pmd, addr));
+	return(pte_offset_map(pmd, addr));
 }
 
 void flush_tlb_page(struct vm_area_struct *vma, unsigned long address)
 {
-        address &= PAGE_MASK;
-        flush_tlb_range(vma, address, address + PAGE_SIZE);
+	address &= PAGE_MASK;
+	flush_tlb_range(vma, address, address + PAGE_SIZE);
 }
 
 void flush_tlb_all(void)
 {
-        flush_tlb_mm(current->mm);
+	flush_tlb_mm(current->mm);
 }
 
 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 {
-        CHOOSE_MODE_PROC(flush_tlb_kernel_range_tt,
-                         flush_tlb_kernel_range_common, start, end);
+	CHOOSE_MODE_PROC(flush_tlb_kernel_range_tt,
+			 flush_tlb_kernel_range_common, start, end);
 }
 
 void flush_tlb_kernel_vm(void)
 {
-        CHOOSE_MODE(flush_tlb_kernel_vm_tt(),
-                    flush_tlb_kernel_range_common(start_vm, end_vm));
+	CHOOSE_MODE(flush_tlb_kernel_vm_tt(),
+		    flush_tlb_kernel_range_common(start_vm, end_vm));
 }
 
 void __flush_tlb_one(unsigned long addr)
 {
-        CHOOSE_MODE_PROC(__flush_tlb_one_tt, __flush_tlb_one_skas, addr);
+	CHOOSE_MODE_PROC(__flush_tlb_one_tt, __flush_tlb_one_skas, addr);
 }
 
 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 		     unsigned long end)
 {
-        CHOOSE_MODE_PROC(flush_tlb_range_tt, flush_tlb_range_skas, vma, start,
-                         end);
+	CHOOSE_MODE_PROC(flush_tlb_range_tt, flush_tlb_range_skas, vma, start,
+			 end);
 }
 
 void flush_tlb_mm(struct mm_struct *mm)
 {
-        CHOOSE_MODE_PROC(flush_tlb_mm_tt, flush_tlb_mm_skas, mm);
+	CHOOSE_MODE_PROC(flush_tlb_mm_tt, flush_tlb_mm_skas, mm);
 }
 
 void force_flush_all(void)
 {
-        CHOOSE_MODE(force_flush_all_tt(), force_flush_all_skas());
+	CHOOSE_MODE(force_flush_all_tt(), force_flush_all_skas());
 }
 
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index ac70fa5..61a23ff 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -140,14 +140,6 @@ void segv_handler(int sig, union uml_pt_regs *regs)
 	segv(*fi, UPT_IP(regs), UPT_IS_USER(regs), regs);
 }
 
-struct kern_handlers handlinfo_kern = {
-	.relay_signal = relay_signal,
-	.winch = winch,
-	.bus_handler = relay_signal,
-	.page_fault = segv_handler,
-	.sigio_handler = sigio_handler,
-	.timer_handler = timer_handler
-};
 /*
  * We give a *copy* of the faultinfo in the regs to segv.
  * This must be done, since nesting SEGVs could overwrite
@@ -227,9 +219,16 @@ void bad_segv(struct faultinfo fi, unsigned long ip)
 
 void relay_signal(int sig, union uml_pt_regs *regs)
 {
-	if(arch_handle_signal(sig, regs)) return;
-	if(!UPT_IS_USER(regs))
+	if(arch_handle_signal(sig, regs))
+		return;
+
+	if(!UPT_IS_USER(regs)){
+		if(sig == SIGBUS)
+			printk("Bus error - the /dev/shm or /tmp mount likely "
+			       "just ran out of space\n");
 		panic("Kernel mode signal %d", sig);
+	}
+
         current->thread.arch.faultinfo = *UPT_FAULTINFO(regs);
 	force_sig(sig, current);
 }
@@ -246,6 +245,15 @@ void winch(int sig, union uml_pt_regs *regs)
 	do_IRQ(WINCH_IRQ, regs);
 }
 
+const struct kern_handlers handlinfo_kern = {
+	.relay_signal = relay_signal,
+	.winch = winch,
+	.bus_handler = bus_handler,
+	.page_fault = segv_handler,
+	.sigio_handler = sigio_handler,
+	.timer_handler = timer_handler
+};
+
 void trap_init(void)
 {
 }
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 7896cf9..5500571 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -106,7 +106,7 @@ static void c_stop(struct seq_file *m, void *v)
 {
 }
 
-struct seq_operations cpuinfo_op = {
+const struct seq_operations cpuinfo_op = {
 	.start	= c_start,
 	.next	= c_next,
 	.stop	= c_stop,
diff --git a/arch/um/os-Linux/Makefile b/arch/um/os-Linux/Makefile
index f4bfc4c..b418392 100644
--- a/arch/um/os-Linux/Makefile
+++ b/arch/um/os-Linux/Makefile
@@ -4,15 +4,19 @@
 #
 
 obj-y = aio.o elf_aux.o file.o helper.o irq.o main.o mem.o process.o sigio.o \
-	signal.o start_up.o time.o trap.o tt.o tty.o uaccess.o umid.o tls.o \
+	signal.o start_up.o time.o trap.o tty.o uaccess.o umid.o tls.o \
 	user_syms.o util.o drivers/ sys-$(SUBARCH)/
 
 obj-$(CONFIG_MODE_SKAS) += skas/
+
+obj-$(CONFIG_MODE_TT) += tt.o
+user-objs-$(CONFIG_MODE_TT) += tt.o
+
 obj-$(CONFIG_TTY_LOG) += tty_log.o
 user-objs-$(CONFIG_TTY_LOG) += tty_log.o
 
 USER_OBJS := $(user-objs-y) aio.o elf_aux.o file.o helper.o irq.o main.o mem.o \
-	process.o sigio.o signal.o start_up.o time.o trap.o tt.o tty.o tls.o \
+	process.o sigio.o signal.o start_up.o time.o trap.o tty.o tls.o \
 	uaccess.o umid.o util.o
 
 CFLAGS_user_syms.o += -DSUBARCH_$(SUBARCH)
diff --git a/arch/um/os-Linux/drivers/etap.h b/arch/um/os-Linux/drivers/etap.h
index b84f6c4..57ecdaf 100644
--- a/arch/um/os-Linux/drivers/etap.h
+++ b/arch/um/os-Linux/drivers/etap.h
@@ -13,7 +13,7 @@ struct ethertap_data {
 	void *dev;
 };
 
-extern struct net_user_info ethertap_user_info;
+extern const struct net_user_info ethertap_user_info;
 
 /*
  * Overrides for Emacs so that we follow Linus's tabbing style.
diff --git a/arch/um/os-Linux/drivers/ethertap_kern.c b/arch/um/os-Linux/drivers/ethertap_kern.c
index 768606b..16385e2 100644
--- a/arch/um/os-Linux/drivers/ethertap_kern.c
+++ b/arch/um/os-Linux/drivers/ethertap_kern.c
@@ -65,7 +65,7 @@ static int etap_write(int fd, struct sk_buff **skb, struct uml_net_private *lp)
 	return(net_send(fd, (*skb)->data, (*skb)->len));
 }
 
-struct net_kern_info ethertap_kern_info = {
+const struct net_kern_info ethertap_kern_info = {
 	.init			= etap_init,
 	.protocol		= eth_protocol,
 	.read			= etap_read,
diff --git a/arch/um/os-Linux/drivers/ethertap_user.c b/arch/um/os-Linux/drivers/ethertap_user.c
index 8f49507..f559bdf7 100644
--- a/arch/um/os-Linux/drivers/ethertap_user.c
+++ b/arch/um/os-Linux/drivers/ethertap_user.c
@@ -216,7 +216,7 @@ static void etap_del_addr(unsigned char *addr, unsigned char *netmask,
 	etap_close_addr(addr, netmask, &pri->control_fd);
 }
 
-struct net_user_info ethertap_user_info = {
+const struct net_user_info ethertap_user_info = {
 	.init		= etap_user_init,
 	.open		= etap_open,
 	.close	 	= etap_close,
diff --git a/arch/um/os-Linux/drivers/tuntap.h b/arch/um/os-Linux/drivers/tuntap.h
index 25d4a28..d3e8d3a 100644
--- a/arch/um/os-Linux/drivers/tuntap.h
+++ b/arch/um/os-Linux/drivers/tuntap.h
@@ -16,7 +16,7 @@ struct tuntap_data {
 	void *dev;
 };
 
-extern struct net_user_info tuntap_user_info;
+extern const struct net_user_info tuntap_user_info;
 
 #endif
 
diff --git a/arch/um/os-Linux/drivers/tuntap_kern.c b/arch/um/os-Linux/drivers/tuntap_kern.c
index 190009a..0edbac6 100644
--- a/arch/um/os-Linux/drivers/tuntap_kern.c
+++ b/arch/um/os-Linux/drivers/tuntap_kern.c
@@ -53,7 +53,7 @@ static int tuntap_write(int fd, struct sk_buff **skb,
 	return(net_write(fd, (*skb)->data, (*skb)->len));
 }
 
-struct net_kern_info tuntap_kern_info = {
+const struct net_kern_info tuntap_kern_info = {
 	.init			= tuntap_init,
 	.protocol		= eth_protocol,
 	.read			= tuntap_read,
diff --git a/arch/um/os-Linux/drivers/tuntap_user.c b/arch/um/os-Linux/drivers/tuntap_user.c
index 87c3aa0..e846b23 100644
--- a/arch/um/os-Linux/drivers/tuntap_user.c
+++ b/arch/um/os-Linux/drivers/tuntap_user.c
@@ -205,7 +205,7 @@ static int tuntap_set_mtu(int mtu, void *data)
 	return(mtu);
 }
 
-struct net_user_info tuntap_user_info = {
+const struct net_user_info tuntap_user_info = {
 	.init		= tuntap_user_init,
 	.open		= tuntap_open,
 	.close	 	= tuntap_close,
diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c
index 6987d1d..cd15b9d 100644
--- a/arch/um/os-Linux/helper.c
+++ b/arch/um/os-Linux/helper.c
@@ -42,7 +42,7 @@ static int helper_child(void *arg)
 	if(data->pre_exec != NULL)
 		(*data->pre_exec)(data->pre_data);
 	execvp(argv[0], argv);
-	errval = errno;
+	errval = -errno;
 	printk("helper_child - execve of '%s' failed - errno = %d\n", argv[0], errno);
 	os_write_file(data->fd, &errval, sizeof(errval));
 	kill(os_getpid(), SIGKILL);
@@ -62,7 +62,7 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv,
 		stack = *stack_out;
 	else stack = alloc_stack(0, __cant_sleep());
 	if(stack == 0)
-		return(-ENOMEM);
+		return -ENOMEM;
 
 	ret = os_pipe(fds, 1, 0);
 	if(ret < 0){
@@ -95,16 +95,16 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv,
 	/* Read the errno value from the child, if the exec failed, or get 0 if
 	 * the exec succeeded because the pipe fd was set as close-on-exec. */
 	n = os_read_file(fds[0], &ret, sizeof(ret));
-	if (n < 0) {
-		printk("run_helper : read on pipe failed, ret = %d\n", -n);
-		ret = n;
-		kill(pid, SIGKILL);
-		CATCH_EINTR(waitpid(pid, NULL, 0));
-	} else if(n != 0){
-		CATCH_EINTR(n = waitpid(pid, NULL, 0));
-		ret = -errno;
-	} else {
+	if(n == 0)
 		ret = pid;
+	else {
+		if(n < 0){
+			printk("run_helper : read on pipe failed, ret = %d\n",
+			       -n);
+			ret = n;
+			kill(pid, SIGKILL);
+		}
+		CATCH_EINTR(waitpid(pid, NULL, 0));
 	}
 
 out_close:
diff --git a/arch/um/os-Linux/irq.c b/arch/um/os-Linux/irq.c
index 7555bf9..a97206d 100644
--- a/arch/um/os-Linux/irq.c
+++ b/arch/um/os-Linux/irq.c
@@ -132,7 +132,7 @@ void os_set_pollfd(int i, int fd)
 
 void os_set_ioignore(void)
 {
-	set_handler(SIGIO, SIG_IGN, 0, -1);
+	signal(SIGIO, SIG_IGN);
 }
 
 void init_irq_signals(int on_sigstack)
diff --git a/arch/um/os-Linux/main.c b/arch/um/os-Linux/main.c
index 90912aa..d1c5670 100644
--- a/arch/um/os-Linux/main.c
+++ b/arch/um/os-Linux/main.c
@@ -67,13 +67,32 @@ static __init void do_uml_initcalls(void)
 
 static void last_ditch_exit(int sig)
 {
-	signal(SIGINT, SIG_DFL);
-	signal(SIGTERM, SIG_DFL);
-	signal(SIGHUP, SIG_DFL);
 	uml_cleanup();
 	exit(1);
 }
 
+static void install_fatal_handler(int sig)
+{
+	struct sigaction action;
+
+	/* All signals are enabled in this handler ... */
+	sigemptyset(&action.sa_mask);
+
+	/* ... including the signal being handled, plus we want the
+	 * handler reset to the default behavior, so that if an exit
+	 * handler is hanging for some reason, the UML will just die
+	 * after this signal is sent a second time.
+	 */
+	action.sa_flags = SA_RESETHAND | SA_NODEFER;
+	action.sa_restorer = NULL;
+	action.sa_handler = last_ditch_exit;
+	if(sigaction(sig, &action, NULL) < 0){
+		printf("failed to install handler for signal %d - errno = %d\n",
+		       errno);
+		exit(1);
+	}
+}
+
 #define UML_LIB_PATH	":/usr/lib/uml"
 
 static void setup_env_path(void)
@@ -158,9 +177,12 @@ int main(int argc, char **argv, char **envp)
 	}
 	new_argv[argc] = NULL;
 
-	set_handler(SIGINT, last_ditch_exit, SA_ONESHOT | SA_NODEFER, -1);
-	set_handler(SIGTERM, last_ditch_exit, SA_ONESHOT | SA_NODEFER, -1);
-	set_handler(SIGHUP, last_ditch_exit, SA_ONESHOT | SA_NODEFER, -1);
+	/* Allow these signals to bring down a UML if all other
+	 * methods of control fail.
+	 */
+	install_fatal_handler(SIGINT);
+	install_fatal_handler(SIGTERM);
+	install_fatal_handler(SIGHUP);
 
 	scan_elf_aux( envp);
 
diff --git a/arch/um/os-Linux/mem.c b/arch/um/os-Linux/mem.c
index 560c806..b170b47 100644
--- a/arch/um/os-Linux/mem.c
+++ b/arch/um/os-Linux/mem.c
@@ -114,14 +114,14 @@ static void which_tmpdir(void)
 	}
 
 	while(1){
-		found = next(fd, buf, sizeof(buf) / sizeof(buf[0]), ' ');
+		found = next(fd, buf, ARRAY_SIZE(buf), ' ');
 		if(found != 1)
 			break;
 
 		if(!strncmp(buf, "/dev/shm", strlen("/dev/shm")))
 			goto found;
 
-		found = next(fd, buf, sizeof(buf) / sizeof(buf[0]), '\n');
+		found = next(fd, buf, ARRAY_SIZE(buf), '\n');
 		if(found != 1)
 			break;
 	}
@@ -135,7 +135,7 @@ err:
 	return;
 
 found:
-	found = next(fd, buf, sizeof(buf) / sizeof(buf[0]), ' ');
+	found = next(fd, buf, ARRAY_SIZE(buf), ' ');
 	if(found != 1)
 		goto err;
 
diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c
index b98d3ca2..ff20362 100644
--- a/arch/um/os-Linux/process.c
+++ b/arch/um/os-Linux/process.c
@@ -7,7 +7,6 @@
 #include <stdio.h>
 #include <errno.h>
 #include <signal.h>
-#include <setjmp.h>
 #include <linux/unistd.h>
 #include <sys/mman.h>
 #include <sys/wait.h>
@@ -247,7 +246,17 @@ void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int))
 		set_sigstack(sig_stack, pages * page_size());
 		flags = SA_ONSTACK;
 	}
-	if(usr1_handler) set_handler(SIGUSR1, usr1_handler, flags, -1);
+	if(usr1_handler){
+		struct sigaction sa;
+
+		sa.sa_handler = usr1_handler;
+		sigemptyset(&sa.sa_mask);
+		sa.sa_flags = flags;
+		sa.sa_restorer = NULL;
+		if(sigaction(SIGUSR1, &sa, NULL) < 0)
+			panic("init_new_thread_stack - sigaction failed - "
+			      "errno = %d\n", errno);
+	}
 }
 
 void init_new_thread_signals(void)
diff --git a/arch/um/os-Linux/sigio.c b/arch/um/os-Linux/sigio.c
index 0ecac56..f645776 100644
--- a/arch/um/os-Linux/sigio.c
+++ b/arch/um/os-Linux/sigio.c
@@ -43,17 +43,9 @@ struct pollfds {
 /* Protected by sigio_lock().  Used by the sigio thread, but the UML thread
  * synchronizes with it.
  */
-static struct pollfds current_poll = {
-	.poll  		= NULL,
-	.size 		= 0,
-	.used 		= 0
-};
-
-static struct pollfds next_poll = {
-	.poll  		= NULL,
-	.size 		= 0,
-	.used 		= 0
-};
+static struct pollfds current_poll;
+static struct pollfds next_poll;
+static struct pollfds all_sigio_fds;
 
 static int write_sigio_thread(void *unused)
 {
@@ -78,7 +70,8 @@ static int write_sigio_thread(void *unused)
 				n = os_read_file(sigio_private[1], &c, sizeof(c));
 				if(n != sizeof(c))
 					printk("write_sigio_thread : "
-					       "read failed, err = %d\n", -n);
+					       "read on socket failed, "
+					       "err = %d\n", -n);
 				tmp = current_poll;
 				current_poll = next_poll;
 				next_poll = tmp;
@@ -93,35 +86,36 @@ static int write_sigio_thread(void *unused)
 
 			n = os_write_file(respond_fd, &c, sizeof(c));
 			if(n != sizeof(c))
-				printk("write_sigio_thread : write failed, "
-				       "err = %d\n", -n);
+				printk("write_sigio_thread : write on socket "
+				       "failed, err = %d\n", -n);
 		}
 	}
 
 	return 0;
 }
 
-static int need_poll(int n)
+static int need_poll(struct pollfds *polls, int n)
 {
-	if(n <= next_poll.size){
-		next_poll.used = n;
-		return(0);
+	if(n <= polls->size){
+		polls->used = n;
+		return 0;
 	}
-	kfree(next_poll.poll);
-	next_poll.poll = um_kmalloc_atomic(n * sizeof(struct pollfd));
-	if(next_poll.poll == NULL){
+	kfree(polls->poll);
+	polls->poll = um_kmalloc_atomic(n * sizeof(struct pollfd));
+	if(polls->poll == NULL){
 		printk("need_poll : failed to allocate new pollfds\n");
-		next_poll.size = 0;
-		next_poll.used = 0;
-		return(-1);
+		polls->size = 0;
+		polls->used = 0;
+		return -ENOMEM;
 	}
-	next_poll.size = n;
-	next_poll.used = n;
-	return(0);
+	polls->size = n;
+	polls->used = n;
+	return 0;
 }
 
 /* Must be called with sigio_lock held, because it's needed by the marked
- * critical section. */
+ * critical section.
+ */
 static void update_thread(void)
 {
 	unsigned long flags;
@@ -156,34 +150,39 @@ static void update_thread(void)
 	set_signals(flags);
 }
 
-static int add_sigio_fd(int fd, int read)
+int add_sigio_fd(int fd)
 {
-	int err = 0, i, n, events;
+	struct pollfd *p;
+	int err = 0, i, n;
 
 	sigio_lock();
+	for(i = 0; i < all_sigio_fds.used; i++){
+		if(all_sigio_fds.poll[i].fd == fd)
+			break;
+	}
+	if(i == all_sigio_fds.used)
+		goto out;
+
+	p = &all_sigio_fds.poll[i];
+
 	for(i = 0; i < current_poll.used; i++){
 		if(current_poll.poll[i].fd == fd)
 			goto out;
 	}
 
 	n = current_poll.used + 1;
-	err = need_poll(n);
+	err = need_poll(&next_poll, n);
 	if(err)
 		goto out;
 
 	for(i = 0; i < current_poll.used; i++)
 		next_poll.poll[i] = current_poll.poll[i];
 
-	if(read) events = POLLIN;
-	else events = POLLOUT;
-
-	next_poll.poll[n - 1] = ((struct pollfd) { .fd  	= fd,
-						   .events 	= events,
-						   .revents 	= 0 });
+	next_poll.poll[n - 1] = *p;
 	update_thread();
  out:
 	sigio_unlock();
-	return(err);
+	return err;
 }
 
 int ignore_sigio_fd(int fd)
@@ -205,18 +204,14 @@ int ignore_sigio_fd(int fd)
 	if(i == current_poll.used)
 		goto out;
 
-	err = need_poll(current_poll.used - 1);
+	err = need_poll(&next_poll, current_poll.used - 1);
 	if(err)
 		goto out;
 
 	for(i = 0; i < current_poll.used; i++){
 		p = &current_poll.poll[i];
-		if(p->fd != fd) next_poll.poll[n++] = current_poll.poll[i];
-	}
-	if(n == i){
-		printk("ignore_sigio_fd : fd %d not found\n", fd);
-		err = -1;
-		goto out;
+		if(p->fd != fd)
+			next_poll.poll[n++] = *p;
 	}
 
 	update_thread();
@@ -234,7 +229,7 @@ static struct pollfd *setup_initial_poll(int fd)
 		printk("setup_initial_poll : failed to allocate poll\n");
 		return NULL;
 	}
-	*p = ((struct pollfd) { .fd  	= fd,
+	*p = ((struct pollfd) { .fd		= fd,
 				.events 	= POLLIN,
 				.revents 	= 0 });
 	return p;
@@ -323,6 +318,8 @@ out_close1:
 
 void maybe_sigio_broken(int fd, int read)
 {
+	int err;
+
 	if(!isatty(fd))
 		return;
 
@@ -330,7 +327,19 @@ void maybe_sigio_broken(int fd, int read)
 		return;
 
 	write_sigio_workaround();
-	add_sigio_fd(fd, read);
+
+	sigio_lock();
+	err = need_poll(&all_sigio_fds, all_sigio_fds.used + 1);
+	if(err){
+		printk("maybe_sigio_broken - failed to add pollfd\n");
+		goto out;
+	}
+	all_sigio_fds.poll[all_sigio_fds.used++] =
+		((struct pollfd) { .fd  	= fd,
+				   .events 	= read ? POLLIN : POLLOUT,
+				   .revents 	= 0 });
+out:
+	sigio_unlock();
 }
 
 static void sigio_cleanup(void)
diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c
index 60e4fae..6b81739 100644
--- a/arch/um/os-Linux/signal.c
+++ b/arch/um/os-Linux/signal.c
@@ -15,7 +15,6 @@
 #include "user.h"
 #include "signal_kern.h"
 #include "sysdep/sigcontext.h"
-#include "sysdep/signal.h"
 #include "sigcontext.h"
 #include "mode.h"
 #include "os.h"
@@ -38,18 +37,10 @@
 static int signals_enabled = 1;
 static int pending = 0;
 
-void sig_handler(ARCH_SIGHDLR_PARAM)
+void sig_handler(int sig, struct sigcontext *sc)
 {
-	struct sigcontext *sc;
 	int enabled;
 
-	/* Must be the first thing that this handler does - x86_64 stores
-	 * the sigcontext in %rdx, and we need to save it before it has a
-	 * chance to get trashed.
-	 */
-
-	ARCH_GET_SIGCONTEXT(sc, sig);
-
 	enabled = signals_enabled;
 	if(!enabled && (sig == SIGIO)){
 		pending |= SIGIO_MASK;
@@ -64,15 +55,8 @@ void sig_handler(ARCH_SIGHDLR_PARAM)
 	set_signals(enabled);
 }
 
-extern int timer_irq_inited;
-
 static void real_alarm_handler(int sig, struct sigcontext *sc)
 {
-	if(!timer_irq_inited){
-		signals_enabled = 1;
-		return;
-	}
-
 	if(sig == SIGALRM)
 		switch_timers(0);
 
@@ -84,13 +68,10 @@ static void real_alarm_handler(int sig, struct sigcontext *sc)
 
 }
 
-void alarm_handler(ARCH_SIGHDLR_PARAM)
+void alarm_handler(int sig, struct sigcontext *sc)
 {
-	struct sigcontext *sc;
 	int enabled;
 
-	ARCH_GET_SIGCONTEXT(sc, sig);
-
 	enabled = signals_enabled;
 	if(!signals_enabled){
 		if(sig == SIGVTALRM)
@@ -126,6 +107,10 @@ void remove_sigstack(void)
 		panic("disabling signal stack failed, errno = %d\n", errno);
 }
 
+void (*handlers[_NSIG])(int sig, struct sigcontext *sc);
+
+extern void hard_handler(int sig);
+
 void set_handler(int sig, void (*handler)(int), int flags, ...)
 {
 	struct sigaction action;
@@ -133,13 +118,16 @@ void set_handler(int sig, void (*handler)(int), int flags, ...)
 	sigset_t sig_mask;
 	int mask;
 
-	va_start(ap, flags);
-	action.sa_handler = handler;
+	handlers[sig] = (void (*)(int, struct sigcontext *)) handler;
+	action.sa_handler = hard_handler;
+
 	sigemptyset(&action.sa_mask);
-	while((mask = va_arg(ap, int)) != -1){
+
+	va_start(ap, flags);
+	while((mask = va_arg(ap, int)) != -1)
 		sigaddset(&action.sa_mask, mask);
-	}
 	va_end(ap);
+
 	action.sa_flags = flags;
 	action.sa_restorer = NULL;
 	if(sigaction(sig, &action, NULL) < 0)
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index 7baf90f..cb9ab54 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -8,7 +8,6 @@
 #include <unistd.h>
 #include <errno.h>
 #include <signal.h>
-#include <setjmp.h>
 #include <sched.h>
 #include "ptrace_user.h"
 #include <sys/wait.h>
@@ -156,11 +155,15 @@ extern int __syscall_stub_start;
 static int userspace_tramp(void *stack)
 {
 	void *addr;
+	int err;
 
 	ptrace(PTRACE_TRACEME, 0, 0, 0);
 
 	init_new_thread_signals();
-	enable_timer();
+	err = set_interval(1);
+	if(err)
+		panic("userspace_tramp - setting timer failed, errno = %d\n",
+		      err);
 
 	if(!proc_mm){
 		/* This has a pte, but it can't be mapped in with the usual
@@ -190,14 +193,25 @@ static int userspace_tramp(void *stack)
 		}
 	}
 	if(!ptrace_faultinfo && (stack != NULL)){
+		struct sigaction sa;
+
 		unsigned long v = UML_CONFIG_STUB_CODE +
 				  (unsigned long) stub_segv_handler -
 				  (unsigned long) &__syscall_stub_start;
 
 		set_sigstack((void *) UML_CONFIG_STUB_DATA, page_size());
-		set_handler(SIGSEGV, (void *) v, SA_ONSTACK,
-			    SIGIO, SIGWINCH, SIGALRM, SIGVTALRM,
-			    SIGUSR1, -1);
+		sigemptyset(&sa.sa_mask);
+		sigaddset(&sa.sa_mask, SIGIO);
+		sigaddset(&sa.sa_mask, SIGWINCH);
+		sigaddset(&sa.sa_mask, SIGALRM);
+		sigaddset(&sa.sa_mask, SIGVTALRM);
+		sigaddset(&sa.sa_mask, SIGUSR1);
+		sa.sa_flags = SA_ONSTACK;
+		sa.sa_handler = (void *) v;
+		sa.sa_restorer = NULL;
+		if(sigaction(SIGSEGV, &sa, NULL) < 0)
+			panic("userspace_tramp - setting SIGSEGV handler "
+			      "failed - errno = %d\n", errno);
 	}
 
 	os_stop_process(os_getpid());
@@ -430,56 +444,22 @@ void map_stub_pages(int fd, unsigned long code,
 	}
 }
 
-void new_thread(void *stack, void **switch_buf_ptr, void **fork_buf_ptr,
-		void (*handler)(int))
+void new_thread(void *stack, jmp_buf *buf, void (*handler)(void))
 {
-	unsigned long flags;
-	jmp_buf switch_buf, fork_buf;
-
-	*switch_buf_ptr = &switch_buf;
-	*fork_buf_ptr = &fork_buf;
-
-	/* Somewhat subtle - siglongjmp restores the signal mask before doing
-	 * the longjmp.  This means that when jumping from one stack to another
-	 * when the target stack has interrupts enabled, an interrupt may occur
-	 * on the source stack.  This is bad when starting up a process because
-	 * it's not supposed to get timer ticks until it has been scheduled.
-	 * So, we disable interrupts around the sigsetjmp to ensure that
-	 * they can't happen until we get back here where they are safe.
-	 */
-	flags = get_signals();
-	block_signals();
-	if(UML_SETJMP(&fork_buf) == 0)
-		new_thread_proc(stack, handler);
-
-	remove_sigstack();
-
-	set_signals(flags);
+	(*buf)[0].JB_IP = (unsigned long) handler;
+	(*buf)[0].JB_SP = (unsigned long) stack +
+		(PAGE_SIZE << UML_CONFIG_KERNEL_STACK_ORDER) - sizeof(void *);
 }
 
 #define INIT_JMP_NEW_THREAD 0
-#define INIT_JMP_REMOVE_SIGSTACK 1
-#define INIT_JMP_CALLBACK 2
-#define INIT_JMP_HALT 3
-#define INIT_JMP_REBOOT 4
+#define INIT_JMP_CALLBACK 1
+#define INIT_JMP_HALT 2
+#define INIT_JMP_REBOOT 3
 
-void thread_wait(void *sw, void *fb)
+void switch_threads(jmp_buf *me, jmp_buf *you)
 {
-	jmp_buf buf, **switch_buf = sw, *fork_buf;
-
-	*switch_buf = &buf;
-	fork_buf = fb;
-	if(UML_SETJMP(&buf) == 0)
-		siglongjmp(*fork_buf, INIT_JMP_REMOVE_SIGSTACK);
-}
-
-void switch_threads(void *me, void *next)
-{
-	jmp_buf my_buf, **me_ptr = me, *next_buf = next;
-
-	*me_ptr = &my_buf;
-	if(UML_SETJMP(&my_buf) == 0)
-		UML_LONGJMP(next_buf, 1);
+	if(UML_SETJMP(me) == 0)
+		UML_LONGJMP(you, 1);
 }
 
 static jmp_buf initial_jmpbuf;
@@ -489,23 +469,21 @@ static void (*cb_proc)(void *arg);
 static void *cb_arg;
 static jmp_buf *cb_back;
 
-int start_idle_thread(void *stack, void *switch_buf_ptr, void **fork_buf_ptr)
+int start_idle_thread(void *stack, jmp_buf *switch_buf)
 {
-	jmp_buf **switch_buf = switch_buf_ptr;
 	int n;
 
 	set_handler(SIGWINCH, (__sighandler_t) sig_handler,
 		    SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGALRM,
 		    SIGVTALRM, -1);
 
-	*fork_buf_ptr = &initial_jmpbuf;
 	n = UML_SETJMP(&initial_jmpbuf);
 	switch(n){
 	case INIT_JMP_NEW_THREAD:
-		new_thread_proc((void *) stack, new_thread_handler);
-		break;
-	case INIT_JMP_REMOVE_SIGSTACK:
-		remove_sigstack();
+		(*switch_buf)[0].JB_IP = (unsigned long) new_thread_handler;
+		(*switch_buf)[0].JB_SP = (unsigned long) stack +
+			(PAGE_SIZE << UML_CONFIG_KERNEL_STACK_ORDER) -
+			sizeof(void *);
 		break;
 	case INIT_JMP_CALLBACK:
 		(*cb_proc)(cb_arg);
@@ -520,7 +498,7 @@ int start_idle_thread(void *stack, void *switch_buf_ptr, void **fork_buf_ptr)
 	default:
 		panic("Bad sigsetjmp return in start_idle_thread - %d\n", n);
 	}
-	UML_LONGJMP(*switch_buf, 1);
+	UML_LONGJMP(switch_buf, 1);
 }
 
 void initial_thread_cb_skas(void (*proc)(void *), void *arg)
diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c
index 5031485..7fe9268 100644
--- a/arch/um/os-Linux/start_up.c
+++ b/arch/um/os-Linux/start_up.c
@@ -14,7 +14,6 @@
 #include <sched.h>
 #include <fcntl.h>
 #include <errno.h>
-#include <setjmp.h>
 #include <sys/time.h>
 #include <sys/wait.h>
 #include <sys/mman.h>
diff --git a/arch/um/os-Linux/sys-i386/Makefile b/arch/um/os-Linux/sys-i386/Makefile
index b321361..3780662 100644
--- a/arch/um/os-Linux/sys-i386/Makefile
+++ b/arch/um/os-Linux/sys-i386/Makefile
@@ -3,7 +3,7 @@
 # Licensed under the GPL
 #
 
-obj-$(CONFIG_MODE_SKAS) = registers.o tls.o
+obj-$(CONFIG_MODE_SKAS) = registers.o signal.o tls.o
 
 USER_OBJS := $(obj-y)
 
diff --git a/arch/um/os-Linux/sys-i386/registers.c b/arch/um/os-Linux/sys-i386/registers.c
index 516f66d..7cd0369 100644
--- a/arch/um/os-Linux/sys-i386/registers.c
+++ b/arch/um/os-Linux/sys-i386/registers.c
@@ -5,12 +5,12 @@
 
 #include <errno.h>
 #include <string.h>
-#include <setjmp.h>
 #include "sysdep/ptrace_user.h"
 #include "sysdep/ptrace.h"
 #include "uml-config.h"
 #include "skas_ptregs.h"
 #include "registers.h"
+#include "longjmp.h"
 #include "user.h"
 
 /* These are set once at boot time and not changed thereafter */
@@ -130,11 +130,14 @@ void get_safe_registers(unsigned long *regs, unsigned long *fp_regs)
 		       HOST_FP_SIZE * sizeof(unsigned long));
 }
 
-void get_thread_regs(union uml_pt_regs *uml_regs, void *buffer)
+unsigned long get_thread_reg(int reg, jmp_buf *buf)
 {
-	struct __jmp_buf_tag *jmpbuf = buffer;
-
-	UPT_SET(uml_regs, EIP, jmpbuf->__jmpbuf[JB_PC]);
-	UPT_SET(uml_regs, UESP, jmpbuf->__jmpbuf[JB_SP]);
-	UPT_SET(uml_regs, EBP, jmpbuf->__jmpbuf[JB_BP]);
+	switch(reg){
+	case EIP: return buf[0]->__eip;
+	case UESP: return buf[0]->__esp;
+	case EBP: return buf[0]->__ebp;
+	default:
+		printk("get_thread_regs - unknown register %d\n", reg);
+		return 0;
+	}
 }
diff --git a/arch/um/os-Linux/sys-i386/signal.c b/arch/um/os-Linux/sys-i386/signal.c
new file mode 100644
index 0000000..0d3eae5
--- /dev/null
+++ b/arch/um/os-Linux/sys-i386/signal.c
@@ -0,0 +1,15 @@
+/*
+ * Copyright (C) 2006 Jeff Dike (jdike@addtoit.com)
+ * Licensed under the GPL
+ */
+
+#include <signal.h>
+
+extern void (*handlers[])(int sig, struct sigcontext *sc);
+
+void hard_handler(int sig)
+{
+	struct sigcontext *sc = (struct sigcontext *) (&sig + 1);
+
+	(*handlers[sig])(sig, sc);
+}
diff --git a/arch/um/os-Linux/sys-x86_64/Makefile b/arch/um/os-Linux/sys-x86_64/Makefile
index 340ef26..f67842a 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-$(CONFIG_MODE_SKAS) = registers.o
+obj-$(CONFIG_MODE_SKAS) = registers.o signal.o
 
 USER_OBJS := $(obj-y)
 
diff --git a/arch/um/os-Linux/sys-x86_64/registers.c b/arch/um/os-Linux/sys-x86_64/registers.c
index becd898..cb8e8a2 100644
--- a/arch/um/os-Linux/sys-x86_64/registers.c
+++ b/arch/um/os-Linux/sys-x86_64/registers.c
@@ -5,11 +5,11 @@
 
 #include <errno.h>
 #include <string.h>
-#include <setjmp.h>
 #include "ptrace_user.h"
 #include "uml-config.h"
 #include "skas_ptregs.h"
 #include "registers.h"
+#include "longjmp.h"
 #include "user.h"
 
 /* These are set once at boot time and not changed thereafter */
@@ -78,11 +78,14 @@ void get_safe_registers(unsigned long *regs, unsigned long *fp_regs)
 		       HOST_FP_SIZE * sizeof(unsigned long));
 }
 
-void get_thread_regs(union uml_pt_regs *uml_regs, void *buffer)
+unsigned long get_thread_reg(int reg, jmp_buf *buf)
 {
-	struct __jmp_buf_tag *jmpbuf = buffer;
-
-	UPT_SET(uml_regs, RIP, jmpbuf->__jmpbuf[JB_PC]);
-	UPT_SET(uml_regs, RSP, jmpbuf->__jmpbuf[JB_RSP]);
-	UPT_SET(uml_regs, RBP, jmpbuf->__jmpbuf[JB_RBP]);
+	switch(reg){
+	case RIP: return buf[0]->__rip;
+	case RSP: return buf[0]->__rsp;
+	case RBP: return buf[0]->__rbp;
+	default:
+		printk("get_thread_regs - unknown register %d\n", reg);
+		return 0;
+	}
 }
diff --git a/arch/um/os-Linux/sys-x86_64/signal.c b/arch/um/os-Linux/sys-x86_64/signal.c
new file mode 100644
index 0000000..3f369e5
--- /dev/null
+++ b/arch/um/os-Linux/sys-x86_64/signal.c
@@ -0,0 +1,16 @@
+/*
+ * Copyright (C) 2006 Jeff Dike (jdike@addtoit.com)
+ * Licensed under the GPL
+ */
+
+#include <signal.h>
+
+extern void (*handlers[])(int sig, struct sigcontext *sc);
+
+void hard_handler(int sig)
+{
+	struct ucontext *uc;
+	asm("movq %%rdx, %0" : "=r" (uc));
+
+	(*handlers[sig])(sig, (struct sigcontext *) &uc->uc_mcontext);
+}
diff --git a/arch/um/os-Linux/time.c b/arch/um/os-Linux/time.c
index 4ae73c0..38be096 100644
--- a/arch/um/os-Linux/time.c
+++ b/arch/um/os-Linux/time.c
@@ -17,20 +17,25 @@
 #include "kern_constants.h"
 #include "os.h"
 
-static void set_interval(int timer_type)
+int set_interval(int is_virtual)
 {
 	int usec = 1000000/hz();
+	int timer_type = is_virtual ? ITIMER_VIRTUAL : ITIMER_REAL;
 	struct itimerval interval = ((struct itimerval) { { 0, usec },
 							  { 0, usec } });
 
 	if(setitimer(timer_type, &interval, NULL) == -1)
-		panic("setitimer failed - errno = %d\n", errno);
+		return -errno;
+
+	return 0;
 }
 
+#ifdef CONFIG_MODE_TT
 void enable_timer(void)
 {
-	set_interval(ITIMER_VIRTUAL);
+	set_interval(1);
 }
+#endif
 
 void disable_timer(void)
 {
@@ -40,8 +45,8 @@ void disable_timer(void)
 		printk("disnable_timer - setitimer failed, errno = %d\n",
 		       errno);
 	/* If there are signals already queued, after unblocking ignore them */
-	set_handler(SIGALRM, SIG_IGN, 0, -1);
-	set_handler(SIGVTALRM, SIG_IGN, 0, -1);
+	signal(SIGALRM, SIG_IGN);
+	signal(SIGVTALRM, SIG_IGN);
 }
 
 void switch_timers(int to_real)
@@ -74,7 +79,7 @@ void uml_idle_timer(void)
 
 	set_handler(SIGALRM, (__sighandler_t) alarm_handler,
 		    SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
-	set_interval(ITIMER_REAL);
+	set_interval(0);
 }
 #endif
 
@@ -94,8 +99,3 @@ void idle_sleep(int secs)
 	ts.tv_nsec = 0;
 	nanosleep(&ts, NULL);
 }
-
-void user_time_init(void)
-{
-	set_interval(ITIMER_VIRTUAL);
-}
diff --git a/arch/um/os-Linux/trap.c b/arch/um/os-Linux/trap.c
index 90b29ae..1df231a 100644
--- a/arch/um/os-Linux/trap.c
+++ b/arch/um/os-Linux/trap.c
@@ -5,7 +5,6 @@
 
 #include <stdlib.h>
 #include <signal.h>
-#include <setjmp.h>
 #include "kern_util.h"
 #include "user_util.h"
 #include "os.h"
diff --git a/arch/um/os-Linux/uaccess.c b/arch/um/os-Linux/uaccess.c
index 865f6a6..bbb73a6 100644
--- a/arch/um/os-Linux/uaccess.c
+++ b/arch/um/os-Linux/uaccess.c
@@ -4,8 +4,7 @@
  * Licensed under the GPL
  */
 
-#include <setjmp.h>
-#include <string.h>
+#include <stddef.h>
 #include "longjmp.h"
 
 unsigned long __do_user_copy(void *to, const void *from, int n,
diff --git a/arch/um/os-Linux/util.c b/arch/um/os-Linux/util.c
index c47a2a7..3f5b151 100644
--- a/arch/um/os-Linux/util.c
+++ b/arch/um/os-Linux/util.c
@@ -7,7 +7,6 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <limits.h>
-#include <setjmp.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
 #include <sys/utsname.h>
@@ -107,11 +106,11 @@ int setjmp_wrapper(void (*proc)(void *, void *), ...)
 	jmp_buf buf;
 	int n;
 
-	n = sigsetjmp(buf, 1);
+	n = UML_SETJMP(&buf);
 	if(n == 0){
 		va_start(args, proc);
 		(*proc)(&buf, &args);
 	}
 	va_end(args);
-	return(n);
+	return n;
 }
diff --git a/arch/um/sys-i386/Makefile b/arch/um/sys-i386/Makefile
index 374d61a..0e32adf 100644
--- a/arch/um/sys-i386/Makefile
+++ b/arch/um/sys-i386/Makefile
@@ -1,10 +1,10 @@
 obj-y = bugs.o checksum.o delay.o fault.o ksyms.o ldt.o ptrace.o \
-	ptrace_user.o signal.o sigcontext.o syscalls.o sysrq.o \
+	ptrace_user.o setjmp.o signal.o sigcontext.o syscalls.o sysrq.o \
 	sys_call_table.o tls.o
 
 obj-$(CONFIG_MODE_SKAS) += stub.o stub_segv.o
 
-subarch-obj-y = lib/bitops.o kernel/semaphore.o
+subarch-obj-y = lib/bitops.o lib/semaphore.o
 subarch-obj-$(CONFIG_HIGHMEM) += mm/highmem.o
 subarch-obj-$(CONFIG_MODULES) += kernel/module.o
 
diff --git a/arch/um/sys-i386/bugs.c b/arch/um/sys-i386/bugs.c
index 41b0ab2..f1bcd39 100644
--- a/arch/um/sys-i386/bugs.c
+++ b/arch/um/sys-i386/bugs.c
@@ -13,6 +13,7 @@
 #include "sysdep/ptrace.h"
 #include "task.h"
 #include "os.h"
+#include "user_util.h"
 
 #define MAXTOKEN 64
 
@@ -104,17 +105,17 @@ int cpu_feature(char *what, char *buf, int len)
 static int check_cpu_flag(char *feature, int *have_it)
 {
 	char buf[MAXTOKEN], c;
-	int fd, len = sizeof(buf)/sizeof(buf[0]);
+	int fd, len = ARRAY_SIZE(buf);
 
 	printk("Checking for host processor %s support...", feature);
 	fd = os_open_file("/proc/cpuinfo", of_read(OPENFLAGS()), 0);
 	if(fd < 0){
 		printk("Couldn't open /proc/cpuinfo, err = %d\n", -fd);
-		return(0);
+		return 0;
 	}
 
 	*have_it = 0;
-	if(!find_cpuinfo_line(fd, "flags", buf, sizeof(buf) / sizeof(buf[0])))
+	if(!find_cpuinfo_line(fd, "flags", buf, ARRAY_SIZE(buf)))
 		goto out;
 
 	c = token(fd, buf, len - 1, ' ');
@@ -138,7 +139,7 @@ static int check_cpu_flag(char *feature, int *have_it)
 	if(*have_it == 0) printk("No\n");
 	else if(*have_it == 1) printk("Yes\n");
 	os_close_file(fd);
-	return(1);
+	return 1;
 }
 
 #if 0 /* This doesn't work in tt mode, plus it's causing compilation problems
diff --git a/arch/um/sys-i386/ldt.c b/arch/um/sys-i386/ldt.c
index fe0877b..69971b7 100644
--- a/arch/um/sys-i386/ldt.c
+++ b/arch/um/sys-i386/ldt.c
@@ -424,9 +424,8 @@ void ldt_get_host_info(void)
 			size++;
 	}
 
-	if(size < sizeof(dummy_list)/sizeof(dummy_list[0])) {
+	if(size < ARRAY_SIZE(dummy_list))
 		host_ldt_entries = dummy_list;
-	}
 	else {
 		size = (size + 1) * sizeof(dummy_list[0]);
 		host_ldt_entries = (short *)kmalloc(size, GFP_KERNEL);
diff --git a/arch/um/sys-i386/ptrace_user.c b/arch/um/sys-i386/ptrace_user.c
index 40aa885..5f3cc668 100644
--- a/arch/um/sys-i386/ptrace_user.c
+++ b/arch/um/sys-i386/ptrace_user.c
@@ -15,6 +15,7 @@
 #include "user.h"
 #include "os.h"
 #include "uml-config.h"
+#include "user_util.h"
 
 int ptrace_getregs(long pid, unsigned long *regs_out)
 {
@@ -51,7 +52,7 @@ static void write_debugregs(int pid, unsigned long *regs)
 	int nregs, i;
 
 	dummy = NULL;
-	nregs = sizeof(dummy->u_debugreg)/sizeof(dummy->u_debugreg[0]);
+	nregs = ARRAY_SIZE(dummy->u_debugreg);
 	for(i = 0; i < nregs; i++){
 		if((i == 4) || (i == 5)) continue;
 		if(ptrace(PTRACE_POKEUSR, pid, &dummy->u_debugreg[i],
@@ -68,7 +69,7 @@ static void read_debugregs(int pid, unsigned long *regs)
 	int nregs, i;
 
 	dummy = NULL;
-	nregs = sizeof(dummy->u_debugreg)/sizeof(dummy->u_debugreg[0]);
+	nregs = ARRAY_SIZE(dummy->u_debugreg);
 	for(i = 0; i < nregs; i++){
 		regs[i] = ptrace(PTRACE_PEEKUSR, pid,
 				 &dummy->u_debugreg[i], 0);
diff --git a/arch/um/sys-i386/setjmp.S b/arch/um/sys-i386/setjmp.S
new file mode 100644
index 0000000..b766792
--- /dev/null
+++ b/arch/um/sys-i386/setjmp.S
@@ -0,0 +1,58 @@
+#
+# arch/i386/setjmp.S
+#
+# setjmp/longjmp for the i386 architecture
+#
+
+#
+# The jmp_buf is assumed to contain the following, in order:
+#	%ebx
+#	%esp
+#	%ebp
+#	%esi
+#	%edi
+#	<return address>
+#
+
+	.text
+	.align 4
+	.globl setjmp
+	.type setjmp, @function
+setjmp:
+#ifdef _REGPARM
+	movl %eax,%edx
+#else
+	movl 4(%esp),%edx
+#endif
+	popl %ecx			# Return address, and adjust the stack
+	xorl %eax,%eax			# Return value
+	movl %ebx,(%edx)
+	movl %esp,4(%edx)		# Post-return %esp!
+	pushl %ecx			# Make the call/return stack happy
+	movl %ebp,8(%edx)
+	movl %esi,12(%edx)
+	movl %edi,16(%edx)
+	movl %ecx,20(%edx)		# Return address
+	ret
+
+	.size setjmp,.-setjmp
+
+	.text
+	.align 4
+	.globl longjmp
+	.type longjmp, @function
+longjmp:
+#ifdef _REGPARM
+	xchgl %eax,%edx
+#else
+	movl 4(%esp),%edx		# jmp_ptr address
+	movl 8(%esp),%eax		# Return value
+#endif
+	movl (%edx),%ebx
+	movl 4(%edx),%esp
+	movl 8(%edx),%ebp
+	movl 12(%edx),%esi
+	movl 16(%edx),%edi
+	jmp *20(%edx)
+
+	.size longjmp,.-longjmp
diff --git a/arch/um/sys-x86_64/Makefile b/arch/um/sys-x86_64/Makefile
index c19794d..f41768b 100644
--- a/arch/um/sys-x86_64/Makefile
+++ b/arch/um/sys-x86_64/Makefile
@@ -5,8 +5,8 @@
 #
 
 obj-y = bugs.o delay.o fault.o ldt.o mem.o ptrace.o ptrace_user.o \
-	sigcontext.o signal.o syscalls.o syscall_table.o sysrq.o ksyms.o \
-	tls.o
+	setjmp.o sigcontext.o signal.o syscalls.o syscall_table.o sysrq.o \
+	ksyms.o tls.o
 
 obj-$(CONFIG_MODE_SKAS) += stub.o stub_segv.o
 obj-$(CONFIG_MODULES) += um_module.o
diff --git a/arch/um/sys-x86_64/setjmp.S b/arch/um/sys-x86_64/setjmp.S
new file mode 100644
index 0000000..45f547b
--- /dev/null
+++ b/arch/um/sys-x86_64/setjmp.S
@@ -0,0 +1,54 @@
+#
+# arch/x86_64/setjmp.S
+#
+# setjmp/longjmp for the x86-64 architecture
+#
+
+#
+# The jmp_buf is assumed to contain the following, in order:
+#	%rbx
+#	%rsp (post-return)
+#	%rbp
+#	%r12
+#	%r13
+#	%r14
+#	%r15
+#	<return address>
+#
+
+	.text
+	.align 4
+	.globl setjmp
+	.type setjmp, @function
+setjmp:
+	pop  %rsi			# Return address, and adjust the stack
+	xorl %eax,%eax			# Return value
+	movq %rbx,(%rdi)
+	movq %rsp,8(%rdi)		# Post-return %rsp!
+	push %rsi			# Make the call/return stack happy
+	movq %rbp,16(%rdi)
+	movq %r12,24(%rdi)
+	movq %r13,32(%rdi)
+	movq %r14,40(%rdi)
+	movq %r15,48(%rdi)
+	movq %rsi,56(%rdi)		# Return address
+	ret
+
+	.size setjmp,.-setjmp
+
+	.text
+	.align 4
+	.globl longjmp
+	.type longjmp, @function
+longjmp:
+	movl %esi,%eax			# Return value (int)
+	movq (%rdi),%rbx
+	movq 8(%rdi),%rsp
+	movq 16(%rdi),%rbp
+	movq 24(%rdi),%r12
+	movq 32(%rdi),%r13
+	movq 40(%rdi),%r14
+	movq 48(%rdi),%r15
+	jmp *56(%rdi)
+
+	.size longjmp,.-longjmp