Merge upstream kernel changes into 'C/H/S support' branch of libata.

77 files changed, 701 insertions, 1058 deletions

diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index c5292181a66..b8e952c88fd 100644
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -35,6 +35,11 @@ config GENERIC_CALIBRATE_DELAY
 	bool
 	default y
 
+# Used in kernel/irq/manage.c and include/linux/irq.h
+config IRQ_RELEASE_METHOD
+	bool
+	default y
+
 menu "UML-specific options"
 
 config MODE_TT
diff --git a/arch/um/Kconfig.debug b/arch/um/Kconfig.debug
index b89989de364..bd41e4286d0 100644
--- a/arch/um/Kconfig.debug
+++ b/arch/um/Kconfig.debug
@@ -2,10 +2,6 @@ menu "Kernel hacking"
 
 source "lib/Kconfig.debug"
 
-config FRAME_POINTER
-	bool
-	default y if DEBUG_INFO
-
 config PT_PROXY
 	bool "Enable ptrace proxy"
 	depends on XTERM_CHAN && DEBUG_INFO && MODE_TT
diff --git a/arch/um/Kconfig_char b/arch/um/Kconfig_char
index 3e50fdb6762..62d87b71179 100644
--- a/arch/um/Kconfig_char
+++ b/arch/um/Kconfig_char
@@ -204,5 +204,11 @@ config UML_RANDOM
 	http://sourceforge.net/projects/gkernel/).  rngd periodically reads
 	/dev/hwrng and injects the entropy into /dev/random.
 
+config MMAPPER
+	tristate "iomem emulation driver"
+	help
+	This driver allows a host file to be used as emulated IO memory inside
+	UML.
+
 endmenu
 
diff --git a/arch/um/Kconfig_x86_64 b/arch/um/Kconfig_x86_64
index fd8d7e8982b..f162f50f0b1 100644
--- a/arch/um/Kconfig_x86_64
+++ b/arch/um/Kconfig_x86_64
@@ -6,6 +6,10 @@ config 64BIT
 	bool
 	default y
 
+config TOP_ADDR
+ 	hex
+	default 0x80000000
+
 config 3_LEVEL_PGTABLES
        bool
        default y
diff --git a/arch/um/Makefile b/arch/um/Makefile
index f2a0c40a920..3f073902351 100644
--- a/arch/um/Makefile
+++ b/arch/um/Makefile
@@ -122,7 +122,7 @@ endif
 CPPFLAGS_vmlinux.lds = $(shell echo -U$(SUBARCH) \
 	-DSTART=$(START) -DELF_ARCH=$(ELF_ARCH) \
 	-DELF_FORMAT=\"$(ELF_FORMAT)\" $(CPP_MODE-y) \
-	-DKERNEL_STACK_SIZE=$(STACK_SIZE))
+	-DKERNEL_STACK_SIZE=$(STACK_SIZE) -DSUBARCH=$(SUBARCH))
 
 #The wrappers will select whether using "malloc" or the kernel allocator.
 LINK_WRAPS = -Wl,--wrap,malloc -Wl,--wrap,free -Wl,--wrap,calloc
diff --git a/arch/um/drivers/Makefile b/arch/um/drivers/Makefile
index 323f72c64cd..b2de9916c32 100644
--- a/arch/um/drivers/Makefile
+++ b/arch/um/drivers/Makefile
@@ -22,8 +22,8 @@ obj-y := stdio_console.o fd.o chan_kern.o chan_user.o line.o
 obj-$(CONFIG_SSL) += ssl.o
 obj-$(CONFIG_STDERR_CONSOLE) += stderr_console.o
 
-obj-$(CONFIG_UML_NET_SLIP) += slip.o
-obj-$(CONFIG_UML_NET_SLIRP) += slirp.o
+obj-$(CONFIG_UML_NET_SLIP) += slip.o slip_common.o
+obj-$(CONFIG_UML_NET_SLIRP) += slirp.o slip_common.o
 obj-$(CONFIG_UML_NET_DAEMON) += daemon.o 
 obj-$(CONFIG_UML_NET_MCAST) += mcast.o 
 #obj-$(CONFIG_UML_NET_PCAP) += pcap.o $(PCAP)
@@ -41,6 +41,6 @@ obj-$(CONFIG_UML_WATCHDOG) += harddog.o
 obj-$(CONFIG_BLK_DEV_COW_COMMON) += cow_user.o
 obj-$(CONFIG_UML_RANDOM) += random.o
 
-USER_OBJS := fd.o null.o pty.o tty.o xterm.o
+USER_OBJS := fd.o null.o pty.o tty.o xterm.o slip_common.o
 
 include arch/um/scripts/Makefile.rules
diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index 0150038af79..14a12d6b3df 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -20,9 +20,17 @@
 #include "os.h"
 
 #ifdef CONFIG_NOCONFIG_CHAN
+
+/* The printk's here are wrong because we are complaining that there is no
+ * output device, but printk is printing to that output device.  The user will
+ * never see the error.  printf would be better, except it can't run on a
+ * kernel stack because it will overflow it.
+ * Use printk for now since that will avoid crashing.
+ */
+
 static void *not_configged_init(char *str, int device, struct chan_opts *opts)
 {
-	printf(KERN_ERR "Using a channel type which is configured out of "
+	printk(KERN_ERR "Using a channel type which is configured out of "
 	       "UML\n");
 	return(NULL);
 }
@@ -30,27 +38,27 @@ static void *not_configged_init(char *str, int device, struct chan_opts *opts)
 static int not_configged_open(int input, int output, int primary, void *data,
 			      char **dev_out)
 {
-	printf(KERN_ERR "Using a channel type which is configured out of "
+	printk(KERN_ERR "Using a channel type which is configured out of "
 	       "UML\n");
 	return(-ENODEV);
 }
 
 static void not_configged_close(int fd, void *data)
 {
-	printf(KERN_ERR "Using a channel type which is configured out of "
+	printk(KERN_ERR "Using a channel type which is configured out of "
 	       "UML\n");
 }
 
 static int not_configged_read(int fd, char *c_out, void *data)
 {
-	printf(KERN_ERR "Using a channel type which is configured out of "
+	printk(KERN_ERR "Using a channel type which is configured out of "
 	       "UML\n");
 	return(-EIO);
 }
 
 static int not_configged_write(int fd, const char *buf, int len, void *data)
 {
-	printf(KERN_ERR "Using a channel type which is configured out of "
+	printk(KERN_ERR "Using a channel type which is configured out of "
 	       "UML\n");
 	return(-EIO);
 }
@@ -58,7 +66,7 @@ static int not_configged_write(int fd, const char *buf, int len, void *data)
 static int not_configged_console_write(int fd, const char *buf, int len,
 				       void *data)
 {
-	printf(KERN_ERR "Using a channel type which is configured out of "
+	printk(KERN_ERR "Using a channel type which is configured out of "
 	       "UML\n");
 	return(-EIO);
 }
@@ -66,7 +74,7 @@ static int not_configged_console_write(int fd, const char *buf, int len,
 static int not_configged_window_size(int fd, void *data, unsigned short *rows,
 				     unsigned short *cols)
 {
-	printf(KERN_ERR "Using a channel type which is configured out of "
+	printk(KERN_ERR "Using a channel type which is configured out of "
 	       "UML\n");
 	return(-ENODEV);
 }
diff --git a/arch/um/drivers/chan_user.c b/arch/um/drivers/chan_user.c
index 583b8e137c3..5d3768156c9 100644
--- a/arch/um/drivers/chan_user.c
+++ b/arch/um/drivers/chan_user.c
@@ -143,22 +143,22 @@ static int winch_tramp(int fd, struct tty_struct *tty, int *fd_out)
 {
 	struct winch_data data;
 	unsigned long stack;
-	int fds[2], pid, n, err;
+	int fds[2], n, err;
 	char c;
 
 	err = os_pipe(fds, 1, 1);
 	if(err < 0){
 		printk("winch_tramp : os_pipe failed, err = %d\n", -err);
-		return(err);
+		goto out;
 	}
 
 	data = ((struct winch_data) { .pty_fd 		= fd,
 				      .pipe_fd 		= fds[1],
 				      .close_me 	= fds[0] } );
-	pid = run_helper_thread(winch_thread, &data, 0, &stack, 0);
-	if(pid < 0){
+	err = run_helper_thread(winch_thread, &data, 0, &stack, 0);
+	if(err < 0){
 		printk("fork of winch_thread failed - errno = %d\n", errno);
-		return(pid);
+		goto out_close;
 	}
 
 	os_close_file(fds[1]);
@@ -168,14 +168,22 @@ static int winch_tramp(int fd, struct tty_struct *tty, int *fd_out)
 		printk("winch_tramp : failed to read synchronization byte\n");
 		printk("read failed, err = %d\n", -n);
 		printk("fd %d will not support SIGWINCH\n", fd);
-		*fd_out = -1;
+                err = -EINVAL;
+		goto out_close1;
 	}
-	return(pid);
+	return err ;
+
+ out_close:
+	os_close_file(fds[1]);
+ out_close1:
+	os_close_file(fds[0]);
+ out:
+	return err;
 }
 
 void register_winch(int fd, struct tty_struct *tty)
 {
-	int pid, thread, thread_fd;
+	int pid, thread, thread_fd = -1;
 	int count;
 	char c = 1;
 
@@ -186,7 +194,7 @@ void register_winch(int fd, struct tty_struct *tty)
 	if(!CHOOSE_MODE_PROC(is_tracer_winch, is_skas_winch, pid, fd,
 			     tty) && (pid == -1)){
 		thread = winch_tramp(fd, tty, &thread_fd);
-		if(fd != -1){
+		if(thread > 0){
 			register_winch_irq(thread_fd, fd, thread, tty);
 
 			count = os_write_file(thread_fd, &c, sizeof(c));
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 025d3be8aca..0f59736db32 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -406,14 +406,12 @@ void line_disable(struct tty_struct *tty, int current_irq)
 	if(line->driver->read_irq == current_irq)
 		free_irq_later(line->driver->read_irq, tty);
 	else {
-		free_irq_by_irq_and_dev(line->driver->read_irq, tty);
 		free_irq(line->driver->read_irq, tty);
 	}
 
 	if(line->driver->write_irq == current_irq)
 		free_irq_later(line->driver->write_irq, tty);
 	else {
-		free_irq_by_irq_and_dev(line->driver->write_irq, tty);
 		free_irq(line->driver->write_irq, tty);
 	}
 
@@ -758,7 +756,6 @@ static void unregister_winch(struct tty_struct *tty)
         if(winch->pid != -1)
                 os_kill_process(winch->pid, 1);
 
-        free_irq_by_irq_and_dev(WINCH_IRQ, winch);
         free_irq(WINCH_IRQ, winch);
         list_del(&winch->list);
         kfree(winch);
diff --git a/arch/um/drivers/mcast_kern.c b/arch/um/drivers/mcast_kern.c
index faf714e87b5..217438cdef3 100644
--- a/arch/um/drivers/mcast_kern.c
+++ b/arch/um/drivers/mcast_kern.c
@@ -73,7 +73,6 @@ int mcast_setup(char *str, char **mac_out, void *data)
 	struct mcast_init *init = data;
 	char *port_str = NULL, *ttl_str = NULL, *remain;
 	char *last;
-	int n;
 
 	*init = ((struct mcast_init)
 		{ .addr 	= "239.192.168.1",
@@ -89,13 +88,12 @@ int mcast_setup(char *str, char **mac_out, void *data)
 	}
 	
 	if(port_str != NULL){
-		n = simple_strtoul(port_str, &last, 10);
+		init->port = simple_strtoul(port_str, &last, 10);
 		if((*last != '\0') || (last == port_str)){
 			printk(KERN_ERR "mcast_setup - Bad port : '%s'\n", 
 			       port_str);
 			return(0);
 		}
-		init->port = htons(n);
 	}
 
 	if(ttl_str != NULL){
diff --git a/arch/um/drivers/mcast_user.c b/arch/um/drivers/mcast_user.c
index 0fe1d9fa913..7a0d115b29d 100644
--- a/arch/um/drivers/mcast_user.c
+++ b/arch/um/drivers/mcast_user.c
@@ -38,7 +38,7 @@ static struct sockaddr_in *new_addr(char *addr, unsigned short port)
 	}
 	sin->sin_family = AF_INET;
 	sin->sin_addr.s_addr = in_aton(addr);
-	sin->sin_port = port;
+	sin->sin_port = htons(port);
 	return(sin);
 }
 
@@ -55,28 +55,25 @@ static int mcast_open(void *data)
 	struct mcast_data *pri = data;
 	struct sockaddr_in *sin = pri->mcast_addr;
 	struct ip_mreq mreq;
-	int fd, yes = 1;
+	int fd = -EINVAL, yes = 1, err = -EINVAL;;
 
 
-	if ((sin->sin_addr.s_addr == 0) || (sin->sin_port == 0)) {
-		fd = -EINVAL;
+	if ((sin->sin_addr.s_addr == 0) || (sin->sin_port == 0))
 		goto out;
-	}
 
 	fd = socket(AF_INET, SOCK_DGRAM, 0);
+
 	if (fd < 0){
 		printk("mcast_open : data socket failed, errno = %d\n", 
 		       errno);
-		fd = -ENOMEM;
+		fd = -errno;
 		goto out;
 	}
 
 	if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
 		printk("mcast_open: SO_REUSEADDR failed, errno = %d\n",
 			errno);
-		os_close_file(fd);
-		fd = -EINVAL;
-		goto out;
+		goto out_close;
 	}
 
 	/* set ttl according to config */
@@ -84,26 +81,20 @@ static int mcast_open(void *data)
 		       sizeof(pri->ttl)) < 0) {
 		printk("mcast_open: IP_MULTICAST_TTL failed, error = %d\n",
 			errno);
-		os_close_file(fd);
-		fd = -EINVAL;
-		goto out;
+		goto out_close;
 	}
 
 	/* set LOOP, so data does get fed back to local sockets */
 	if (setsockopt(fd, SOL_IP, IP_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
 		printk("mcast_open: IP_MULTICAST_LOOP failed, error = %d\n",
 			errno);
-		os_close_file(fd);
-		fd = -EINVAL;
-		goto out;
+		goto out_close;
 	}
 
 	/* bind socket to mcast address */
 	if (bind(fd, (struct sockaddr *) sin, sizeof(*sin)) < 0) {
 		printk("mcast_open : data bind failed, errno = %d\n", errno);
-		os_close_file(fd);
-		fd = -EINVAL;
-		goto out;
+		goto out_close;
 	}		
 	
 	/* subscribe to the multicast group */
@@ -117,12 +108,15 @@ static int mcast_open(void *data)
 		       "interface on the host.\n");
 		printk("eth0 should be configured in order to use the "
 		       "multicast transport.\n");
-		os_close_file(fd);
-		fd = -EINVAL;
+                goto out_close;
 	}
 
  out:
-	return(fd);
+	return fd;
+
+ out_close:
+        os_close_file(fd);
+        return err;
 }
 
 static void mcast_close(int fd, void *data)
@@ -164,14 +158,3 @@ struct net_user_info mcast_user_info = {
 	.delete_address = NULL,
 	.max_packet	= MAX_PACKET - ETH_HEADER_OTHER
 };
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/drivers/mmapper_kern.c b/arch/um/drivers/mmapper_kern.c
index a63231dffe0..a37a5ac13c2 100644
--- a/arch/um/drivers/mmapper_kern.c
+++ b/arch/um/drivers/mmapper_kern.c
@@ -18,6 +18,7 @@
 #include <linux/slab.h>
 #include <linux/init.h> 
 #include <linux/smp_lock.h>
+#include <linux/miscdevice.h>
 #include <asm/uaccess.h>
 #include <asm/irq.h>
 #include <asm/pgtable.h>
@@ -117,24 +118,39 @@ static struct file_operations mmapper_fops = {
 	.release	= mmapper_release,
 };
 
+static struct miscdevice mmapper_dev = {
+	.minor		= MISC_DYNAMIC_MINOR,
+	.name		= "mmapper",
+	.fops		= &mmapper_fops
+};
+
 static int __init mmapper_init(void)
 {
+	int err;
+
 	printk(KERN_INFO "Mapper v0.1\n");
 
 	v_buf = (char *) find_iomem("mmapper", &mmapper_size);
 	if(mmapper_size == 0){
 		printk(KERN_ERR "mmapper_init - find_iomem failed\n");
-		return(0);
+		goto out;
 	}
 
-	p_buf = __pa(v_buf);
+	err = misc_register(&mmapper_dev);
+	if(err){
+		printk(KERN_ERR "mmapper - misc_register failed, err = %d\n",
+		       err);
+		goto out;
+	}
 
-	devfs_mk_cdev(MKDEV(30, 0), S_IFCHR|S_IRUGO|S_IWUGO, "mmapper");
-	return(0);
+	p_buf = __pa(v_buf);
+out:
+	return 0;
 }
 
 static void mmapper_exit(void)
 {
+	misc_deregister(&mmapper_dev);
 }
 
 module_init(mmapper_init);
diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
index 4eeaf88c1e9..5388a742869 100644
--- a/arch/um/drivers/net_kern.c
+++ b/arch/um/drivers/net_kern.c
@@ -146,7 +146,6 @@ static int uml_net_close(struct net_device *dev)
 	netif_stop_queue(dev);
 	spin_lock(&lp->lock);
 
-	free_irq_by_irq_and_dev(dev->irq, dev);
 	free_irq(dev->irq, dev);
 	if(lp->close != NULL)
 		(*lp->close)(lp->fd, &lp->user);
diff --git a/arch/um/drivers/net_user.c b/arch/um/drivers/net_user.c
index 47229fe4a81..3730d4f1271 100644
--- a/arch/um/drivers/net_user.c
+++ b/arch/um/drivers/net_user.c
@@ -32,7 +32,7 @@ int tap_open_common(void *dev, char *gate_addr)
 	return(0);
 }
 
-void tap_check_ips(char *gate_addr, char *eth_addr)
+void tap_check_ips(char *gate_addr, unsigned char *eth_addr)
 {
 	int tap_addr[4];
 
diff --git a/arch/um/drivers/port_kern.c b/arch/um/drivers/port_kern.c
index b5ee07472f7..c41efd207fc 100644
--- a/arch/um/drivers/port_kern.c
+++ b/arch/um/drivers/port_kern.c
@@ -257,7 +257,6 @@ int port_wait(void *data)
 		 * connection.  Then we loop here throwing out failed 
 		 * connections until a good one is found.
 		 */
-		free_irq_by_irq_and_dev(TELNETD_IRQ, conn);
 		free_irq(TELNETD_IRQ, conn);
 
 		if(conn->fd >= 0) break;
diff --git a/arch/um/drivers/random.c b/arch/um/drivers/random.c
index d43e9fab05a..f9e22198e01 100644
--- a/arch/um/drivers/random.c
+++ b/arch/um/drivers/random.c
@@ -1,5 +1,10 @@
-/* Much of this ripped from hw_random.c */
-
+/* Copyright (C) 2005 Jeff Dike <jdike@addtoit.com> */
+/* Much of this ripped from drivers/char/hw_random.c, see there for other
+ * copyright.
+ *
+ * This software may be used and distributed according to the terms
+ * of the GNU General Public License, incorporated herein by reference.
+ */
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/miscdevice.h>
@@ -12,8 +17,6 @@
  */
 #define RNG_VERSION "1.0.0"
 #define RNG_MODULE_NAME "random"
-#define RNG_DRIVER_NAME   RNG_MODULE_NAME " virtual driver " RNG_VERSION
-#define PFX RNG_MODULE_NAME ": "
 
 #define RNG_MISCDEV_MINOR		183 /* official */
 
@@ -98,7 +101,7 @@ static int __init rng_init (void)
 
 	err = misc_register (&rng_miscdev);
 	if (err) {
-		printk (KERN_ERR PFX "misc device register failed\n");
+		printk (KERN_ERR RNG_MODULE_NAME ": misc device register failed\n");
 		goto err_out_cleanup_hw;
 	}
 
@@ -120,3 +123,6 @@ static void __exit rng_cleanup (void)
 
 module_init (rng_init);
 module_exit (rng_cleanup);
+
+MODULE_DESCRIPTION("UML Host Random Number Generator (RNG) driver");
+MODULE_LICENSE("GPL");
diff --git a/arch/um/drivers/slip.h b/arch/um/drivers/slip.h
index 495f2f1b142..bb0dab41c2e 100644
--- a/arch/um/drivers/slip.h
+++ b/arch/um/drivers/slip.h
@@ -1,10 +1,7 @@
 #ifndef __UM_SLIP_H
 #define __UM_SLIP_H
 
-#define BUF_SIZE 1500
- /* two bytes each for a (pathological) max packet of escaped chars +  * 
-  * terminating END char + initial END char                            */
-#define ENC_BUF_SIZE (2 * BUF_SIZE + 2)
+#include "slip_common.h"
 
 struct slip_data {
 	void *dev;
@@ -12,28 +9,12 @@ struct slip_data {
 	char *addr;
 	char *gate_addr;
 	int slave;
-	char ibuf[ENC_BUF_SIZE];
-	char obuf[ENC_BUF_SIZE];
-	int more; /* more data: do not read fd until ibuf has been drained */
-	int pos;
-	int esc;
+	struct slip_proto slip;
 };
 
 extern struct net_user_info slip_user_info;
 
-extern int set_umn_addr(int fd, char *addr, char *ptp_addr);
 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);
 
 #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/drivers/slip_common.c b/arch/um/drivers/slip_common.c
new file mode 100644
index 00000000000..e89cfc68fc3
--- /dev/null
+++ b/arch/um/drivers/slip_common.c
@@ -0,0 +1,54 @@
+#include <string.h>
+#include "slip_common.h"
+#include "net_user.h"
+
+int slip_proto_read(int fd, void *buf, int len, struct slip_proto *slip)
+{
+	int i, n, size, start;
+
+	if(slip->more > 0){
+		i = 0;
+		while(i < slip->more){
+			size = slip_unesc(slip->ibuf[i++], slip->ibuf,
+					  &slip->pos, &slip->esc);
+			if(size){
+				memcpy(buf, slip->ibuf, size);
+				memmove(slip->ibuf, &slip->ibuf[i],
+					slip->more - i);
+				slip->more = slip->more - i;
+				return size;
+			}
+		}
+		slip->more = 0;
+	}
+
+	n = net_read(fd, &slip->ibuf[slip->pos],
+		     sizeof(slip->ibuf) - slip->pos);
+	if(n <= 0)
+		return n;
+
+	start = slip->pos;
+	for(i = 0; i < n; i++){
+		size = slip_unesc(slip->ibuf[start + i], slip->ibuf,&slip->pos,
+				  &slip->esc);
+		if(size){
+			memcpy(buf, slip->ibuf, size);
+			memmove(slip->ibuf, &slip->ibuf[start+i+1],
+				n - (i + 1));
+			slip->more = n - (i + 1);
+			return size;
+		}
+	}
+	return 0;
+}
+
+int slip_proto_write(int fd, void *buf, int len, struct slip_proto *slip)
+{
+	int actual, n;
+
+	actual = slip_esc(buf, slip->obuf, len);
+	n = net_write(fd, slip->obuf, actual);
+	if(n < 0)
+		return n;
+	else return len;
+}
diff --git a/arch/um/drivers/slip_proto.h b/arch/um/drivers/slip_common.h
index 7206361ace4..2ae76d8f1be 100644
--- a/arch/um/drivers/slip_proto.h
+++ b/arch/um/drivers/slip_common.h
@@ -1,10 +1,10 @@
-/* 
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
+#ifndef __UM_SLIP_COMMON_H
+#define __UM_SLIP_COMMON_H
 
-#ifndef __UM_SLIP_PROTO_H__
-#define __UM_SLIP_PROTO_H__
+#define BUF_SIZE 1500
+ /* two bytes each for a (pathological) max packet of escaped chars +  *
+  * terminating END char + initial END char                            */
+#define ENC_BUF_SIZE (2 * BUF_SIZE + 2)
 
 /* SLIP protocol characters. */
 #define SLIP_END             0300	/* indicates end of frame	*/
@@ -12,7 +12,8 @@
 #define SLIP_ESC_END         0334	/* ESC ESC_END means END 'data'	*/
 #define SLIP_ESC_ESC         0335	/* ESC ESC_ESC means ESC 'data'	*/
 
-static inline int slip_unesc(unsigned char c,char *buf,int *pos, int *esc)
+static inline int slip_unesc(unsigned char c, unsigned char *buf, int *pos,
+                             int *esc)
 {
 	int ret;
 
@@ -79,15 +80,25 @@ static inline int slip_esc(unsigned char *s, unsigned char *d, int len)
 	return (ptr - d);
 }
 
-#endif
+struct slip_proto {
+	unsigned char ibuf[ENC_BUF_SIZE];
+	unsigned char obuf[ENC_BUF_SIZE];
+	int more; /* more data: do not read fd until ibuf has been drained */
+	int pos;
+	int esc;
+};
+
+#define SLIP_PROTO_INIT { \
+	.ibuf  	= { '\0' }, \
+	.obuf  	= { '\0' }, \
+        .more	= 0, \
+	.pos	= 0, \
+	.esc	= 0 \
+}
 
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
+extern int slip_proto_read(int fd, void *buf, int len,
+			   struct slip_proto *slip);
+extern int slip_proto_write(int fd, void *buf, int len,
+			    struct slip_proto *slip);
+
+#endif
diff --git a/arch/um/drivers/slip_kern.c b/arch/um/drivers/slip_kern.c
index 0886eedba21..9a6f5c85f90 100644
--- a/arch/um/drivers/slip_kern.c
+++ b/arch/um/drivers/slip_kern.c
@@ -26,16 +26,16 @@ void slip_init(struct net_device *dev, void *data)
 		  .addr		= NULL,
 		  .gate_addr 	= init->gate_addr,
 		  .slave  	= -1,
-		  .ibuf  	= { '\0' },
-		  .obuf  	= { '\0' },
-		  .pos 		= 0,
-		  .esc 		= 0,
+		  .slip		= SLIP_PROTO_INIT,
 		  .dev 		= dev });
 
 	dev->init = NULL;
+	dev->header_cache_update = NULL;
+	dev->hard_header_cache = NULL;
+	dev->hard_header = NULL;
 	dev->hard_header_len = 0;
-	dev->addr_len = 4;
-	dev->type = ARPHRD_ETHER;
+	dev->addr_len = 0;
+	dev->type = ARPHRD_SLIP;
 	dev->tx_queue_len = 256;
 	dev->flags = IFF_NOARP;
 	printk("SLIP backend - SLIP IP = %s\n", spri->gate_addr);
diff --git a/arch/um/drivers/slip_user.c b/arch/um/drivers/slip_user.c
index d94846b1b4c..71af444e591 100644
--- a/arch/um/drivers/slip_user.c
+++ b/arch/um/drivers/slip_user.c
@@ -13,7 +13,7 @@
 #include "user.h"
 #include "net_user.h"
 #include "slip.h"
-#include "slip_proto.h"
+#include "slip_common.h"
 #include "helper.h"
 #include "os.h"
 
@@ -77,41 +77,51 @@ static int slip_tramp(char **argv, int fd)
 	err = os_pipe(fds, 1, 0);
 	if(err < 0){
 		printk("slip_tramp : pipe failed, err = %d\n", -err);
-		return(err);
+		goto out;
 	}
 
 	err = 0;
 	pe_data.stdin = fd;
 	pe_data.stdout = fds[1];
 	pe_data.close_me = fds[0];
-	pid = run_helper(slip_pre_exec, &pe_data, argv, NULL);
+	err = run_helper(slip_pre_exec, &pe_data, argv, NULL);
+	if(err < 0)
+		goto out_close;
+	pid = err;
+
+	output_len = page_size();
+	output = um_kmalloc(output_len);
+	if(output == NULL){
+		printk("slip_tramp : failed to allocate output buffer\n");
+		os_kill_process(pid, 1);
+		err = -ENOMEM;
+		goto out_free;
+	}
 
-	if(pid < 0) err = pid;
-	else {
-		output_len = page_size();
-		output = um_kmalloc(output_len);
-		if(output == NULL)
-			printk("slip_tramp : failed to allocate output "
-			       "buffer\n");
-
-		os_close_file(fds[1]);
-		read_output(fds[0], output, output_len);
-		if(output != NULL){
-			printk("%s", output);
-			kfree(output);
-		}
-		CATCH_EINTR(err = waitpid(pid, &status, 0));
-		if(err < 0)
-			err = errno;
-		else if(!WIFEXITED(status) || (WEXITSTATUS(status) != 0)){
-			printk("'%s' didn't exit with status 0\n", argv[0]);
-			err = -EINVAL;
-		}
+	os_close_file(fds[1]);
+	read_output(fds[0], output, output_len);
+	printk("%s", output);
+
+	CATCH_EINTR(err = waitpid(pid, &status, 0));
+	if(err < 0)
+		err = errno;
+	else if(!WIFEXITED(status) || (WEXITSTATUS(status) != 0)){
+		printk("'%s' didn't exit with status 0\n", argv[0]);
+		err = -EINVAL;
 	}
+	else err = 0;
 
 	os_close_file(fds[0]);
 
-	return(err);
+out_free:
+	kfree(output);
+	return err;
+
+out_close:
+	os_close_file(fds[0]);
+	os_close_file(fds[1]);
+out:
+	return err;
 }
 
 static int slip_open(void *data)
@@ -123,21 +133,26 @@ static int slip_open(void *data)
 			 NULL };
 	int sfd, mfd, err;
 
-	mfd = get_pty();
-	if(mfd < 0){
-		printk("umn : Failed to open pty, err = %d\n", -mfd);
-		return(mfd);
+	err = get_pty();
+	if(err < 0){
+		printk("slip-open : Failed to open pty, err = %d\n", -err);
+		goto out;
 	}
-	sfd = os_open_file(ptsname(mfd), of_rdwr(OPENFLAGS()), 0);
-	if(sfd < 0){
-		printk("Couldn't open tty for slip line, err = %d\n", -sfd);
-		os_close_file(mfd);
-		return(sfd);
+	mfd = err;
+
+	err = os_open_file(ptsname(mfd), of_rdwr(OPENFLAGS()), 0);
+	if(err < 0){
+		printk("Couldn't open tty for slip line, err = %d\n", -err);
+		goto out_close;
 	}
-	if(set_up_tty(sfd)) return(-1);
+	sfd = err;
+
+	if(set_up_tty(sfd))
+		goto out_close2;
+
 	pri->slave = sfd;
-	pri->pos = 0;
-	pri->esc = 0;
+	pri->slip.pos = 0;
+	pri->slip.esc = 0;
 	if(pri->gate_addr != NULL){
 		sprintf(version_buf, "%d", UML_NET_VERSION);
 		strcpy(gate_buf, pri->gate_addr);
@@ -146,12 +161,12 @@ static int slip_open(void *data)
 
 		if(err < 0){
 			printk("slip_tramp failed - err = %d\n", -err);
-			return(err);
+			goto out_close2;
 		}
 		err = os_get_ifname(pri->slave, pri->name);
 		if(err < 0){
 			printk("get_ifname failed, err = %d\n", -err);
-			return(err);
+			goto out_close2;
 		}
 		iter_addresses(pri->dev, open_addr, pri->name);
 	}
@@ -160,10 +175,16 @@ static int slip_open(void *data)
 		if(err < 0){
 			printk("Failed to set slip discipline encapsulation - "
 			       "err = %d\n", -err);
-			return(err);
+			goto out_close2;
 		}
 	}
 	return(mfd);
+out_close2:
+	os_close_file(sfd);
+out_close:
+	os_close_file(mfd);
+out:
+	return err;
 }
 
 static void slip_close(int fd, void *data)
@@ -190,48 +211,12 @@ static void slip_close(int fd, void *data)
 
 int slip_user_read(int fd, void *buf, int len, struct slip_data *pri)
 {
-	int i, n, size, start;
-
-	if(pri->more>0) {
-		i = 0;
-		while(i < pri->more) {
-			size = slip_unesc(pri->ibuf[i++],
-					pri->ibuf, &pri->pos, &pri->esc);
-			if(size){
-				memcpy(buf, pri->ibuf, size);
-				memmove(pri->ibuf, &pri->ibuf[i], pri->more-i);
-				pri->more=pri->more-i; 
-				return(size);
-			}
-		}
-		pri->more=0;
-	}
-
-	n = net_read(fd, &pri->ibuf[pri->pos], sizeof(pri->ibuf) - pri->pos);
-	if(n <= 0) return(n);
-
-	start = pri->pos;
-	for(i = 0; i < n; i++){
-		size = slip_unesc(pri->ibuf[start + i],
-				pri->ibuf, &pri->pos, &pri->esc);
-		if(size){
-			memcpy(buf, pri->ibuf, size);
-			memmove(pri->ibuf, &pri->ibuf[start+i+1], n-(i+1));
-			pri->more=n-(i+1); 
-			return(size);
-		}
-	}
-	return(0);
+	return slip_proto_read(fd, buf, len, &pri->slip);
 }
 
 int slip_user_write(int fd, void *buf, int len, struct slip_data *pri)
 {
-	int actual, n;
-
-	actual = slip_esc(buf, pri->obuf, len);
-	n = net_write(fd, pri->obuf, actual);
-	if(n < 0) return(n);
-	else return(len);
+	return slip_proto_write(fd, buf, len, &pri->slip);
 }
 
 static int slip_set_mtu(int mtu, void *data)
@@ -267,14 +252,3 @@ struct net_user_info slip_user_info = {
 	.delete_address = slip_del_addr,
 	.max_packet	= BUF_SIZE
 };
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/drivers/slirp.h b/arch/um/drivers/slirp.h
index 04e407d1e44..6cf88ab580c 100644
--- a/arch/um/drivers/slirp.h
+++ b/arch/um/drivers/slirp.h
@@ -1,10 +1,7 @@
 #ifndef __UM_SLIRP_H
 #define __UM_SLIRP_H
 
-#define BUF_SIZE 1500
- /* two bytes each for a (pathological) max packet of escaped chars +  * 
-  * terminating END char + initial END char                            */
-#define ENC_BUF_SIZE (2 * BUF_SIZE + 2)
+#include "slip_common.h"
 
 #define SLIRP_MAX_ARGS 100
 /*
@@ -24,28 +21,13 @@ struct slirp_data {
 	struct arg_list_dummy_wrapper argw;
 	int pid;
 	int slave;
-	char ibuf[ENC_BUF_SIZE];
-	char obuf[ENC_BUF_SIZE];
-	int more; /* more data: do not read fd until ibuf has been drained */
-	int pos;
-	int esc;
+	struct slip_proto slip;
 };
 
 extern struct net_user_info slirp_user_info;
 
-extern int set_umn_addr(int fd, char *addr, char *ptp_addr);
 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, struct slirp_data *pri);
+extern int slirp_user_write(int fd, void *buf, int len,
+			    struct slirp_data *pri);
 
 #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/drivers/slirp_kern.c b/arch/um/drivers/slirp_kern.c
index c9d6b52a831..9864d27afdb 100644
--- a/arch/um/drivers/slirp_kern.c
+++ b/arch/um/drivers/slirp_kern.c
@@ -25,10 +25,7 @@ void slirp_init(struct net_device *dev, void *data)
 		{ .argw 	= init->argw,
 		  .pid  	= -1,
 		  .slave  	= -1,
-		  .ibuf  	= { '\0' },
-		  .obuf  	= { '\0' },
-		  .pos 		= 0,
-		  .esc 		= 0,
+		  .slip		= SLIP_PROTO_INIT,
 		  .dev 		= dev });
 
 	dev->init = NULL;
diff --git a/arch/um/drivers/slirp_user.c b/arch/um/drivers/slirp_user.c
index c322515c71c..8d91f663d82 100644
--- a/arch/um/drivers/slirp_user.c
+++ b/arch/um/drivers/slirp_user.c
@@ -12,7 +12,7 @@
 #include "user.h"
 #include "net_user.h"
 #include "slirp.h"
-#include "slip_proto.h"
+#include "slip_common.h"
 #include "helper.h"
 #include "os.h"
 
@@ -48,47 +48,32 @@ static int slirp_tramp(char **argv, int fd)
 	return(pid);
 }
 
-/* XXX This is just a trivial wrapper around os_pipe */
-static int slirp_datachan(int *mfd, int *sfd)
-{
-	int fds[2], err;
-
-	err = os_pipe(fds, 1, 1);
-	if(err < 0){
-		printk("slirp_datachan: Failed to open pipe, err = %d\n", -err);
-		return(err);
-	}
-
-	*mfd = fds[0];
-	*sfd = fds[1];
-	return(0);
-}
-
 static int slirp_open(void *data)
 {
 	struct slirp_data *pri = data;
-	int sfd, mfd, pid, err;
+	int fds[2], pid, err;
 
-	err = slirp_datachan(&mfd, &sfd);
+	err = os_pipe(fds, 1, 1);
 	if(err)
 		return(err);
 
-	pid = slirp_tramp(pri->argw.argv, sfd);
-
-	if(pid < 0){
-		printk("slirp_tramp failed - errno = %d\n", -pid);
-		os_close_file(sfd);	
-		os_close_file(mfd);	
-		return(pid);
+	err = slirp_tramp(pri->argw.argv, fds[1]);
+	if(err < 0){
+		printk("slirp_tramp failed - errno = %d\n", -err);
+		goto out;
 	}
-
-	pri->slave = sfd;
-	pri->pos = 0;
-	pri->esc = 0;
-
-	pri->pid = pid;
-
-	return(mfd);
+	pid = err;
+
+	pri->slave = fds[1];
+	pri->slip.pos = 0;
+	pri->slip.esc = 0;
+	pri->pid = err;
+
+	return(fds[0]);
+out:
+	os_close_file(fds[0]);
+	os_close_file(fds[1]);
+	return err;
 }
 
 static void slirp_close(int fd, void *data)
@@ -129,48 +114,12 @@ static void slirp_close(int fd, void *data)
 
 int slirp_user_read(int fd, void *buf, int len, struct slirp_data *pri)
 {
-	int i, n, size, start;
-
-	if(pri->more>0) {
-		i = 0;
-		while(i < pri->more) {
-			size = slip_unesc(pri->ibuf[i++],
-					pri->ibuf,&pri->pos,&pri->esc);
-			if(size){
-				memcpy(buf, pri->ibuf, size);
-				memmove(pri->ibuf, &pri->ibuf[i], pri->more-i);
-				pri->more=pri->more-i; 
-				return(size);
-			}
-		}
-		pri->more=0;
-	}
-
-	n = net_read(fd, &pri->ibuf[pri->pos], sizeof(pri->ibuf) - pri->pos);
-	if(n <= 0) return(n);
-
-	start = pri->pos;
-	for(i = 0; i < n; i++){
-		size = slip_unesc(pri->ibuf[start + i],
-				pri->ibuf,&pri->pos,&pri->esc);
-		if(size){
-			memcpy(buf, pri->ibuf, size);
-			memmove(pri->ibuf, &pri->ibuf[start+i+1], n-(i+1));
-			pri->more=n-(i+1); 
-			return(size);
-		}
-	}
-	return(0);
+	return slip_proto_read(fd, buf, len, &pri->slip);
 }
 
 int slirp_user_write(int fd, void *buf, int len, struct slirp_data *pri)
 {
-	int actual, n;
-
-	actual = slip_esc(buf, pri->obuf, len);
-	n = net_write(fd, pri->obuf, actual);
-	if(n < 0) return(n);
-	else return(len);
+	return slip_proto_write(fd, buf, len, &pri->slip);
 }
 
 static int slirp_set_mtu(int mtu, void *data)
@@ -188,14 +137,3 @@ struct net_user_info slirp_user_info = {
 	.delete_address = NULL,
 	.max_packet	= BUF_SIZE
 };
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/drivers/ssl.c b/arch/um/drivers/ssl.c
index a2bac429f3d..b32a77010fb 100644
--- a/arch/um/drivers/ssl.c
+++ b/arch/um/drivers/ssl.c
@@ -22,7 +22,6 @@
 #include "init.h"
 #include "irq_user.h"
 #include "mconsole_kern.h"
-#include "2_5compat.h"
 
 static int ssl_version = 1;
 
diff --git a/arch/um/drivers/stderr_console.c b/arch/um/drivers/stderr_console.c
index 98565b53d17..429ae8e6c7e 100644
--- a/arch/um/drivers/stderr_console.c
+++ b/arch/um/drivers/stderr_console.c
@@ -22,9 +22,9 @@ static void stderr_console_write(struct console *console, const char *string,
 }
 
 static struct console stderr_console = {
-	.name		"stderr",
-	.write		stderr_console_write,
-	.flags		CON_PRINTBUFFER,
+	.name		= "stderr",
+	.write		= stderr_console_write,
+	.flags		= CON_PRINTBUFFER,
 };
 
 static int __init stderr_console_init(void)
diff --git a/arch/um/drivers/stdio_console.c b/arch/um/drivers/stdio_console.c
index 361d0be342b..afbe1e71ed8 100644
--- a/arch/um/drivers/stdio_console.c
+++ b/arch/um/drivers/stdio_console.c
@@ -28,7 +28,6 @@
 #include "irq_user.h"
 #include "mconsole_kern.h"
 #include "init.h"
-#include "2_5compat.h"
 
 #define MAX_TTYS (16)
 
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 9a56ff94308..2a7f6892c55 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -49,13 +49,12 @@
 #include "irq_user.h"
 #include "irq_kern.h"
 #include "ubd_user.h"
-#include "2_5compat.h"
 #include "os.h"
 #include "mem.h"
 #include "mem_kern.h"
 #include "cow.h"
 
-enum ubd_req { UBD_READ, UBD_WRITE, UBD_MMAP };
+enum ubd_req { UBD_READ, UBD_WRITE };
 
 struct io_thread_req {
 	enum ubd_req op;
@@ -68,8 +67,6 @@ struct io_thread_req {
 	unsigned long sector_mask;
 	unsigned long long cow_offset;
 	unsigned long bitmap_words[2];
-	int map_fd;
-	unsigned long long map_offset;
 	int error;
 };
 
@@ -122,10 +119,6 @@ static int ubd_ioctl(struct inode * inode, struct file * file,
 
 #define MAX_DEV (8)
 
-/* Changed in early boot */
-static int ubd_do_mmap = 0;
-#define UBD_MMAP_BLOCK_SIZE PAGE_SIZE
-
 static struct block_device_operations ubd_blops = {
         .owner		= THIS_MODULE,
         .open		= ubd_open,
@@ -175,12 +168,6 @@ struct ubd {
 	int no_cow;
 	struct cow cow;
 	struct platform_device pdev;
-
-	int map_writes;
-	int map_reads;
-	int nomap_writes;
-	int nomap_reads;
-	int write_maps;
 };
 
 #define DEFAULT_COW { \
@@ -200,11 +187,6 @@ struct ubd {
 	.openflags =		OPEN_FLAGS, \
         .no_cow =               0, \
         .cow =			DEFAULT_COW, \
-	.map_writes		= 0, \
-	.map_reads		= 0, \
-	.nomap_writes		= 0, \
-	.nomap_reads		= 0, \
-	.write_maps		= 0, \
 }
 
 struct ubd ubd_dev[MAX_DEV] = { [ 0 ... MAX_DEV - 1 ] = DEFAULT_UBD };
@@ -314,13 +296,6 @@ static int ubd_setup_common(char *str, int *index_out)
 		int major;
 
 		str++;
-		if(!strcmp(str, "mmap")){
-			CHOOSE_MODE(printk("mmap not supported by the ubd "
-					   "driver in tt mode\n"),
-				    ubd_do_mmap = 1);
-			return(0);
-		}
-
 		if(!strcmp(str, "sync")){
 			global_openflags = of_sync(global_openflags);
 			return(0);
@@ -464,9 +439,9 @@ static int udb_setup(char *str)
 __setup("udb", udb_setup);
 __uml_help(udb_setup,
 "udb\n"
-"    This option is here solely to catch ubd -> udb typos, which can be\n\n"
-"    to impossible to catch visually unless you specifically look for\n\n"
-"    them.  The only result of any option starting with 'udb' is an error\n\n"
+"    This option is here solely to catch ubd -> udb typos, which can be\n"
+"    to impossible to catch visually unless you specifically look for\n"
+"    them.  The only result of any option starting with 'udb' is an error\n"
 "    in the boot output.\n\n"
 );
 
@@ -524,7 +499,7 @@ static void ubd_handler(void)
 {
 	struct io_thread_req req;
 	struct request *rq = elv_next_request(ubd_queue);
-	int n, err;
+	int n;
 
 	do_ubd = NULL;
 	intr_count++;
@@ -538,19 +513,6 @@ static void ubd_handler(void)
 		return;
 	}
         
-	if((req.op != UBD_MMAP) &&
-	   ((req.offset != ((__u64) (rq->sector)) << 9) ||
-	    (req.length != (rq->current_nr_sectors) << 9)))
-		panic("I/O op mismatch");
-	
-	if(req.map_fd != -1){
-		err = physmem_subst_mapping(req.buffer, req.map_fd,
-					    req.map_offset, 1);
-		if(err)
-			printk("ubd_handler - physmem_subst_mapping failed, "
-			       "err = %d\n", -err);
-	}
-
 	ubd_finish(rq, req.error);
 	reactivate_fd(thread_fd, UBD_IRQ);	
 	do_ubd_request(ubd_queue);
@@ -583,14 +545,10 @@ static int ubd_file_size(struct ubd *dev, __u64 *size_out)
 
 static void ubd_close(struct ubd *dev)
 {
-	if(ubd_do_mmap)
-		physmem_forget_descriptor(dev->fd);
 	os_close_file(dev->fd);
 	if(dev->cow.file == NULL)
 		return;
 
-	if(ubd_do_mmap)
-		physmem_forget_descriptor(dev->cow.fd);
 	os_close_file(dev->cow.fd);
 	vfree(dev->cow.bitmap);
 	dev->cow.bitmap = NULL;
@@ -1010,94 +968,13 @@ static void cowify_req(struct io_thread_req *req, unsigned long *bitmap,
 			   req->bitmap_words, bitmap_len);
 }
 
-static int mmap_fd(struct request *req, struct ubd *dev, __u64 offset)
-{
-	__u64 sector;
-	unsigned char *bitmap;
-	int bit, i;
-
-	/* mmap must have been requested on the command line */
-	if(!ubd_do_mmap)
-		return(-1);
-
-	/* The buffer must be page aligned */
-	if(((unsigned long) req->buffer % UBD_MMAP_BLOCK_SIZE) != 0)
-		return(-1);
-
-	/* The request must be a page long */
-	if((req->current_nr_sectors << 9) != PAGE_SIZE)
-		return(-1);
-
-	if(dev->cow.file == NULL)
-		return(dev->fd);
-
-	sector = offset >> 9;
-	bitmap = (unsigned char *) dev->cow.bitmap;
-	bit = ubd_test_bit(sector, bitmap);
-
-	for(i = 1; i < req->current_nr_sectors; i++){
-		if(ubd_test_bit(sector + i, bitmap) != bit)
-			return(-1);
-	}
-
-	if(bit || (rq_data_dir(req) == WRITE))
-		offset += dev->cow.data_offset;
-
-	/* The data on disk must be page aligned */
-	if((offset % UBD_MMAP_BLOCK_SIZE) != 0)
-		return(-1);
-
-	return(bit ? dev->fd : dev->cow.fd);
-}
-
-static int prepare_mmap_request(struct ubd *dev, int fd, __u64 offset,
-				struct request *req,
-				struct io_thread_req *io_req)
-{
-	int err;
-
-	if(rq_data_dir(req) == WRITE){
-		/* Writes are almost no-ops since the new data is already in the
-		 * host page cache
-		 */
-		dev->map_writes++;
-		if(dev->cow.file != NULL)
-			cowify_bitmap(io_req->offset, io_req->length,
-				      &io_req->sector_mask, &io_req->cow_offset,
-				      dev->cow.bitmap, dev->cow.bitmap_offset,
-				      io_req->bitmap_words,
-				      dev->cow.bitmap_len);
-	}
-	else {
-		int w;
-
-		if((dev->cow.file != NULL) && (fd == dev->cow.fd))
-			w = 0;
-		else w = dev->openflags.w;
-
-		if((dev->cow.file != NULL) && (fd == dev->fd))
-			offset += dev->cow.data_offset;
-
-		err = physmem_subst_mapping(req->buffer, fd, offset, w);
-		if(err){
-			printk("physmem_subst_mapping failed, err = %d\n",
-			       -err);
-			return(1);
-		}
-		dev->map_reads++;
-	}
-	io_req->op = UBD_MMAP;
-	io_req->buffer = req->buffer;
-	return(0);
-}
-
 /* Called with ubd_io_lock held */
 static int prepare_request(struct request *req, struct io_thread_req *io_req)
 {
 	struct gendisk *disk = req->rq_disk;
 	struct ubd *dev = disk->private_data;
 	__u64 offset;
-	int len, fd;
+	int len;
 
 	if(req->rq_status == RQ_INACTIVE) return(1);
 
@@ -1114,34 +991,12 @@ static int prepare_request(struct request *req, struct io_thread_req *io_req)
 
 	io_req->fds[0] = (dev->cow.file != NULL) ? dev->cow.fd : dev->fd;
 	io_req->fds[1] = dev->fd;
-	io_req->map_fd = -1;
 	io_req->cow_offset = -1;
 	io_req->offset = offset;
 	io_req->length = len;
 	io_req->error = 0;
 	io_req->sector_mask = 0;
 
-	fd = mmap_fd(req, dev, io_req->offset);
-	if(fd > 0){
-		/* If mmapping is otherwise OK, but the first access to the
-		 * page is a write, then it's not mapped in yet.  So we have
-		 * to write the data to disk first, then we can map the disk
-		 * page in and continue normally from there.
-		 */
-		if((rq_data_dir(req) == WRITE) && !is_remapped(req->buffer)){
-			io_req->map_fd = dev->fd;
-			io_req->map_offset = io_req->offset +
-				dev->cow.data_offset;
-			dev->write_maps++;
-		}
-		else return(prepare_mmap_request(dev, fd, io_req->offset, req,
-						 io_req));
-	}
-
-	if(rq_data_dir(req) == READ)
-		dev->nomap_reads++;
-	else dev->nomap_writes++;
-
 	io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE;
 	io_req->offsets[0] = 0;
 	io_req->offsets[1] = dev->cow.data_offset;
@@ -1229,143 +1084,6 @@ static int ubd_ioctl(struct inode * inode, struct file * file,
 	return(-EINVAL);
 }
 
-static int ubd_check_remapped(int fd, unsigned long address, int is_write,
-			      __u64 offset)
-{
-	__u64 bitmap_offset;
-	unsigned long new_bitmap[2];
-	int i, err, n;
-
-	/* If it's not a write access, we can't do anything about it */
-	if(!is_write)
-		return(0);
-
-	/* We have a write */
-	for(i = 0; i < sizeof(ubd_dev) / sizeof(ubd_dev[0]); i++){
-		struct ubd *dev = &ubd_dev[i];
-
-		if((dev->fd != fd) && (dev->cow.fd != fd))
-			continue;
-
-		/* It's a write to a ubd device */
-
-		/* This should be impossible now */
-		if(!dev->openflags.w){
-			/* It's a write access on a read-only device - probably
-			 * shouldn't happen.  If the kernel is trying to change
-			 * something with no intention of writing it back out,
-			 * then this message will clue us in that this needs
-			 * fixing
-			 */
-			printk("Write access to mapped page from readonly ubd "
-			       "device %d\n", i);
-			return(0);
-		}
-
-		/* It's a write to a writeable ubd device - it must be COWed
-		 * because, otherwise, the page would have been mapped in
-		 * writeable
-		 */
-
-		if(!dev->cow.file)
-			panic("Write fault on writeable non-COW ubd device %d",
-			      i);
-
-		/* It should also be an access to the backing file since the
-		 * COW pages should be mapped in read-write
-		 */
-
-		if(fd == dev->fd)
-			panic("Write fault on a backing page of ubd "
-			      "device %d\n", i);
-
-		/* So, we do the write, copying the backing data to the COW
-		 * file...
-		 */
-
-		err = os_seek_file(dev->fd, offset + dev->cow.data_offset);
-		if(err < 0)
-			panic("Couldn't seek to %lld in COW file of ubd "
-			      "device %d, err = %d",
-			      offset + dev->cow.data_offset, i, -err);
-
-		n = os_write_file(dev->fd, (void *) address, PAGE_SIZE);
-		if(n != PAGE_SIZE)
-			panic("Couldn't copy data to COW file of ubd "
-			      "device %d, err = %d", i, -n);
-
-		/* ... updating the COW bitmap... */
-
-		cowify_bitmap(offset, PAGE_SIZE, NULL, &bitmap_offset,
-			      dev->cow.bitmap, dev->cow.bitmap_offset,
-			      new_bitmap, dev->cow.bitmap_len);
-
-		err = os_seek_file(dev->fd, bitmap_offset);
-		if(err < 0)
-			panic("Couldn't seek to %lld in COW file of ubd "
-			      "device %d, err = %d", bitmap_offset, i, -err);
-
-		n = os_write_file(dev->fd, new_bitmap, sizeof(new_bitmap));
-		if(n != sizeof(new_bitmap))
-			panic("Couldn't update bitmap  of ubd device %d, "
-			      "err = %d", i, -n);
-
-		/* Maybe we can map the COW page in, and maybe we can't.  If
-		 * it is a pre-V3 COW file, we can't, since the alignment will
-		 * be wrong.  If it is a V3 or later COW file which has been
-		 * moved to a system with a larger page size, then maybe we
-		 * can't, depending on the exact location of the page.
-		 */
-
-		offset += dev->cow.data_offset;
-
-		/* Remove the remapping, putting the original anonymous page
-		 * back.  If the COW file can be mapped in, that is done.
-		 * Otherwise, the COW page is read in.
-		 */
-
-		if(!physmem_remove_mapping((void *) address))
-			panic("Address 0x%lx not remapped by ubd device %d",
-			      address, i);
-		if((offset % UBD_MMAP_BLOCK_SIZE) == 0)
-			physmem_subst_mapping((void *) address, dev->fd,
-					      offset, 1);
-		else {
-			err = os_seek_file(dev->fd, offset);
-			if(err < 0)
-				panic("Couldn't seek to %lld in COW file of "
-				      "ubd device %d, err = %d", offset, i,
-				      -err);
-
-			n = os_read_file(dev->fd, (void *) address, PAGE_SIZE);
-			if(n != PAGE_SIZE)
-				panic("Failed to read page from offset %llx of "
-				      "COW file of ubd device %d, err = %d",
-				      offset, i, -n);
-		}
-
-		return(1);
-	}
-
-	/* It's not a write on a ubd device */
-	return(0);
-}
-
-static struct remapper ubd_remapper = {
-	.list	= LIST_HEAD_INIT(ubd_remapper.list),
-	.proc	= ubd_check_remapped,
-};
-
-static int ubd_remapper_setup(void)
-{
-	if(ubd_do_mmap)
-		register_remapper(&ubd_remapper);
-
-	return(0);
-}
-
-__initcall(ubd_remapper_setup);
-
 static int same_backing_files(char *from_cmdline, char *from_cow, char *cow)
 {
 	struct uml_stat buf1, buf2;
@@ -1568,15 +1286,6 @@ void do_io(struct io_thread_req *req)
 	int err;
 	__u64 off;
 
-	if(req->op == UBD_MMAP){
-		/* Touch the page to force the host to do any necessary IO to
-		 * get it into memory
-		 */
-		n = *((volatile int *) req->buffer);
-		req->error = update_bitmap(req);
-		return;
-	}
-
 	nsectors = req->length / req->sectorsize;
 	start = 0;
 	do {
diff --git a/arch/um/drivers/xterm_kern.c b/arch/um/drivers/xterm_kern.c
index a4fdf3584ad..d269a80f4b0 100644
--- a/arch/um/drivers/xterm_kern.c
+++ b/arch/um/drivers/xterm_kern.c
@@ -69,7 +69,6 @@ int xterm_fd(int socket, int *pid_out)
 	 * isn't set) this will hang... */
 	wait_for_completion(&data->ready);
 
-	free_irq_by_irq_and_dev(XTERM_IRQ, data);
 	free_irq(XTERM_IRQ, data);
 
 	ret = data->new_fd;
diff --git a/arch/um/include/2_5compat.h b/arch/um/include/2_5compat.h
deleted file mode 100644
index abdb015a4d7..00000000000
--- a/arch/um/include/2_5compat.h
+++ /dev/null
@@ -1,24 +0,0 @@
-/* 
- * Copyright (C) 2001 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#ifndef __2_5_COMPAT_H__
-#define __2_5_COMPAT_H__
-
-#define INIT_HARDSECT(arr, maj, sizes)
-
-#define SET_PRI(task) do ; 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/mconsole.h b/arch/um/include/mconsole.h
index 9fbe3083fdd..cfa368e045a 100644
--- a/arch/um/include/mconsole.h
+++ b/arch/um/include/mconsole.h
@@ -56,7 +56,7 @@ struct mc_request
 	int as_interrupt;
 
 	int originating_fd;
-	int originlen;
+	unsigned int originlen;
 	unsigned char origin[128];			/* sockaddr_un */
 
 	struct mconsole_request request;
diff --git a/arch/um/include/net_user.h b/arch/um/include/net_user.h
index 36807b796e9..89885a77a77 100644
--- a/arch/um/include/net_user.h
+++ b/arch/um/include/net_user.h
@@ -35,7 +35,7 @@ extern void *get_output_buffer(int *len_out);
 extern void free_output_buffer(void *buffer);
 
 extern int tap_open_common(void *dev, char *gate_addr);
-extern void tap_check_ips(char *gate_addr, char *eth_addr);
+extern void tap_check_ips(char *gate_addr, unsigned char *eth_addr);
 
 extern void read_output(int fd, char *output_out, int len);
 
diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index d246d5a2460..881d2988d2d 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -136,7 +136,7 @@ extern int os_seek_file(int fd, __u64 offset);
 extern int os_open_file(char *file, struct openflags flags, int mode);
 extern int os_read_file(int fd, void *buf, int len);
 extern int os_write_file(int fd, const void *buf, int count);
-extern int os_file_size(char *file, long long *size_out);
+extern int os_file_size(char *file, unsigned long long *size_out);
 extern int os_file_modtime(char *file, unsigned long *modtime);
 extern int os_pipe(int *fd, int stream, int close_on_exec);
 extern int os_set_fd_async(int fd, int owner);
diff --git a/arch/um/include/sysdep-i386/ptrace.h b/arch/um/include/sysdep-i386/ptrace.h
index 84ec7ff5cf8..c8ee9559f3a 100644
--- a/arch/um/include/sysdep-i386/ptrace.h
+++ b/arch/um/include/sysdep-i386/ptrace.h
@@ -8,6 +8,8 @@
 
 #include "uml-config.h"
 #include "user_constants.h"
+#include "sysdep/faultinfo.h"
+#include "choose-mode.h"
 
 #define MAX_REG_NR (UM_FRAME_SIZE / sizeof(unsigned long))
 #define MAX_REG_OFFSET (UM_FRAME_SIZE)
@@ -31,7 +33,6 @@ extern int sysemu_supported;
 #ifdef UML_CONFIG_MODE_SKAS
 
 #include "skas_ptregs.h"
-#include "sysdep/faultinfo.h"
 
 #define REGS_IP(r) ((r)[HOST_IP])
 #define REGS_SP(r) ((r)[HOST_SP])
@@ -59,8 +60,6 @@ extern int sysemu_supported;
 #define PTRACE_SYSEMU_SINGLESTEP 32
 #endif
 
-#include "choose-mode.h"
-
 union uml_pt_regs {
 #ifdef UML_CONFIG_MODE_TT
 	struct tt_regs {
diff --git a/arch/um/include/sysdep-x86_64/checksum.h b/arch/um/include/sysdep-x86_64/checksum.h
index 572c6c19be3..ea97005af69 100644
--- a/arch/um/include/sysdep-x86_64/checksum.h
+++ b/arch/um/include/sysdep-x86_64/checksum.h
@@ -9,8 +9,6 @@
 #include "linux/in6.h"
 #include "asm/uaccess.h"
 
-extern unsigned int csum_partial_copy_from(const unsigned char *src, unsigned char *dst, int len,
-					   int sum, int *err_ptr);
 extern unsigned csum_partial(const unsigned char *buff, unsigned len,
                              unsigned sum);
 
@@ -31,10 +29,15 @@ unsigned int csum_partial_copy_nocheck(const unsigned char *src, unsigned char *
 }
 
 static __inline__
-unsigned int csum_partial_copy_from_user(const unsigned char *src, unsigned char *dst,
-					 int len, int sum, int *err_ptr)
+unsigned int csum_partial_copy_from_user(const unsigned char *src,
+                                         unsigned char *dst, int len, int sum,
+                                         int *err_ptr)
 {
-	return csum_partial_copy_from(src, dst, len, sum, err_ptr);
+        if(copy_from_user(dst, src, len)){
+                *err_ptr = -EFAULT;
+                return(-1);
+        }
+        return csum_partial(dst, len, sum);
 }
 
 /**
@@ -137,15 +140,6 @@ static inline unsigned add32_with_carry(unsigned a, unsigned b)
         return a;
 }
 
-#endif
+extern unsigned short ip_compute_csum(unsigned char * buff, int len);
 
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
+#endif
diff --git a/arch/um/include/sysdep-x86_64/ptrace.h b/arch/um/include/sysdep-x86_64/ptrace.h
index 348e8fcd513..be8acd5efd9 100644
--- a/arch/um/include/sysdep-x86_64/ptrace.h
+++ b/arch/um/include/sysdep-x86_64/ptrace.h
@@ -135,6 +135,7 @@ extern int mode_tt;
 	__CHOOSE_MODE(SC_EFLAGS(UPT_SC(r)), REGS_EFLAGS((r)->skas.regs))
 #define UPT_SC(r) ((r)->tt.sc)
 #define UPT_SYSCALL_NR(r) __CHOOSE_MODE((r)->tt.syscall, (r)->skas.syscall)
+#define UPT_SYSCALL_RET(r) UPT_RAX(r)
 
 extern int user_context(unsigned long sp);
 
@@ -196,32 +197,32 @@ struct syscall_args {
 
 
 #define UPT_SET(regs, reg, val) \
-        ({      unsigned long val; \
+        ({      unsigned long __upt_val = val; \
                 switch(reg){ \
-		case R8: UPT_R8(regs) = val; break; \
-		case R9: UPT_R9(regs) = val; break; \
-		case R10: UPT_R10(regs) = val; break; \
-		case R11: UPT_R11(regs) = val; break; \
-		case R12: UPT_R12(regs) = val; break; \
-		case R13: UPT_R13(regs) = val; break; \
-		case R14: UPT_R14(regs) = val; break; \
-		case R15: UPT_R15(regs) = val; break; \
-                case RIP: UPT_IP(regs) = val; break; \
-                case RSP: UPT_SP(regs) = val; break; \
-                case RAX: UPT_RAX(regs) = val; break; \
-                case RBX: UPT_RBX(regs) = val; break; \
-                case RCX: UPT_RCX(regs) = val; break; \
-                case RDX: UPT_RDX(regs) = val; break; \
-                case RSI: UPT_RSI(regs) = val; break; \
-                case RDI: UPT_RDI(regs) = val; break; \
-                case RBP: UPT_RBP(regs) = val; break; \
-                case ORIG_RAX: UPT_ORIG_RAX(regs) = val; break; \
-                case CS: UPT_CS(regs) = val; break; \
-                case DS: UPT_DS(regs) = val; break; \
-                case ES: UPT_ES(regs) = val; break; \
-                case FS: UPT_FS(regs) = val; break; \
-                case GS: UPT_GS(regs) = val; break; \
-                case EFLAGS: UPT_EFLAGS(regs) = val; break; \
+                case R8: UPT_R8(regs) = __upt_val; break; \
+                case R9: UPT_R9(regs) = __upt_val; break; \
+                case R10: UPT_R10(regs) = __upt_val; break; \
+                case R11: UPT_R11(regs) = __upt_val; break; \
+                case R12: UPT_R12(regs) = __upt_val; break; \
+                case R13: UPT_R13(regs) = __upt_val; break; \
+                case R14: UPT_R14(regs) = __upt_val; break; \
+                case R15: UPT_R15(regs) = __upt_val; break; \
+                case RIP: UPT_IP(regs) = __upt_val; break; \
+                case RSP: UPT_SP(regs) = __upt_val; break; \
+                case RAX: UPT_RAX(regs) = __upt_val; break; \
+                case RBX: UPT_RBX(regs) = __upt_val; break; \
+                case RCX: UPT_RCX(regs) = __upt_val; break; \
+                case RDX: UPT_RDX(regs) = __upt_val; break; \
+                case RSI: UPT_RSI(regs) = __upt_val; break; \
+                case RDI: UPT_RDI(regs) = __upt_val; break; \
+                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 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);  \
 			break; \
@@ -245,14 +246,3 @@ struct syscall_args {
         CHOOSE_MODE((&(r)->tt.faultinfo), (&(r)->skas.faultinfo))
 
 #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/sysrq.h b/arch/um/include/sysrq.h
index 2ce9423460b..c8d332b56b9 100644
--- a/arch/um/include/sysrq.h
+++ b/arch/um/include/sysrq.h
@@ -1,6 +1,7 @@
 #ifndef __UM_SYSRQ_H
 #define __UM_SYSRQ_H
 
-extern void show_trace(unsigned long *stack);
+struct task_struct;
+extern void show_trace(struct task_struct* task, unsigned long *stack);
 
 #endif
diff --git a/arch/um/include/user_util.h b/arch/um/include/user_util.h
index b8c5b8a9525..7b6a24dfd30 100644
--- a/arch/um/include/user_util.h
+++ b/arch/um/include/user_util.h
@@ -41,9 +41,6 @@ extern unsigned long highmem;
 extern char host_info[];
 
 extern char saved_command_line[];
-extern char command_line[];
-
-extern char *tempdir;
 
 extern unsigned long _stext, _etext, _sdata, _edata, __bss_start, _end;
 extern unsigned long _unprotected_end;
diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile
index 9736ca27c5f..a8918e80df9 100644
--- a/arch/um/kernel/Makefile
+++ b/arch/um/kernel/Makefile
@@ -14,7 +14,7 @@ obj-y = config.o exec_kern.o exitcode.o \
 	tlb.o trap_kern.o trap_user.o uaccess_user.o um_arch.o umid.o \
 	user_util.o
 
-obj-$(CONFIG_BLK_DEV_INITRD) += initrd_kern.o initrd_user.o
+obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o
 obj-$(CONFIG_GPROF)	+= gprof_syms.o
 obj-$(CONFIG_GCOV)	+= gmon_syms.o
 obj-$(CONFIG_TTY_LOG)	+= tty_log.o
diff --git a/arch/um/kernel/checksum.c b/arch/um/kernel/checksum.c
deleted file mode 100644
index e69de29bb2d..00000000000
--- a/arch/um/kernel/checksum.c
+++ /dev/null
diff --git a/arch/um/kernel/exec_kern.c b/arch/um/kernel/exec_kern.c
index 49ddabe69be..efd222ffe20 100644
--- a/arch/um/kernel/exec_kern.c
+++ b/arch/um/kernel/exec_kern.c
@@ -16,7 +16,6 @@
 #include "kern.h"
 #include "irq_user.h"
 #include "tlb.h"
-#include "2_5compat.h"
 #include "os.h"
 #include "time_user.h"
 #include "choose-mode.h"
diff --git a/arch/um/kernel/initrd_kern.c b/arch/um/kernel/initrd.c
index fc568af468b..82ecf904b09 100644
--- a/arch/um/kernel/initrd_kern.c
+++ b/arch/um/kernel/initrd.c
@@ -41,12 +41,31 @@ static int __init uml_initrd_setup(char *line, int *add)
 	return 0;
 }
 
-__uml_setup("initrd=", uml_initrd_setup, 
+__uml_setup("initrd=", uml_initrd_setup,
 "initrd=<initrd image>\n"
 "    This is used to boot UML from an initrd image.  The argument is the\n"
 "    name of the file containing the image.\n\n"
 );
 
+int load_initrd(char *filename, void *buf, int size)
+{
+	int fd, n;
+
+	fd = os_open_file(filename, of_read(OPENFLAGS()), 0);
+	if(fd < 0){
+		printk("Opening '%s' failed - err = %d\n", filename, -fd);
+		return(-1);
+	}
+	n = os_read_file(fd, buf, size);
+	if(n != size){
+		printk("Read of %d bytes from '%s' failed, err = %d\n", size,
+		       filename, -n);
+		return(-1);
+	}
+
+	os_close_file(fd);
+	return(0);
+}
 /*
  * Overrides for Emacs so that we follow Linus's tabbing style.
  * Emacs will notice this stuff at the end of the file and automatically
diff --git a/arch/um/kernel/initrd_user.c b/arch/um/kernel/initrd_user.c
deleted file mode 100644
index cb90681e151..00000000000
--- a/arch/um/kernel/initrd_user.c
+++ /dev/null
@@ -1,46 +0,0 @@
-/*
- * Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#include <unistd.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <errno.h>
-
-#include "user_util.h"
-#include "kern_util.h"
-#include "user.h"
-#include "initrd.h"
-#include "os.h"
-
-int load_initrd(char *filename, void *buf, int size)
-{
-	int fd, n;
-
-	fd = os_open_file(filename, of_read(OPENFLAGS()), 0);
-	if(fd < 0){
-		printk("Opening '%s' failed - err = %d\n", filename, -fd);
-		return(-1);
-	}
-	n = os_read_file(fd, buf, size);
-	if(n != size){
-		printk("Read of %d bytes from '%s' failed, err = %d\n", size,
-		       filename, -n);
-		return(-1);
-	}
-
-	os_close_file(fd);
-	return(0);
-}
-
-/*
- * 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 d44fb528254..9f18061ef4c 100644
--- a/arch/um/kernel/irq.c
+++ b/arch/um/kernel/irq.c
@@ -124,14 +124,16 @@ void irq_unlock(unsigned long flags)
 	spin_unlock_irqrestore(&irq_spinlock, flags);
 }
 
-/*  presently hw_interrupt_type must define (startup || enable) &&
- *  disable && end */
+/* hw_interrupt_type must define (startup || enable) &&
+ * (shutdown || disable) && end */
 static void dummy(unsigned int irq)
 {
 }
 
-static struct hw_interrupt_type SIGIO_irq_type = {
+/* This is used for everything else than the timer. */
+static struct hw_interrupt_type normal_irq_type = {
 	.typename = "SIGIO",
+	.release = free_irq_by_irq_and_dev,
 	.disable = dummy,
 	.enable = dummy,
 	.ack = dummy,
@@ -140,6 +142,7 @@ static struct hw_interrupt_type SIGIO_irq_type = {
 
 static struct hw_interrupt_type SIGVTALRM_irq_type = {
 	.typename = "SIGVTALRM",
+	.release = free_irq_by_irq_and_dev,
 	.shutdown = dummy, /* never called */
 	.disable = dummy,
 	.enable = dummy,
@@ -160,7 +163,7 @@ void __init init_IRQ(void)
 		irq_desc[i].status = IRQ_DISABLED;
 		irq_desc[i].action = NULL;
 		irq_desc[i].depth = 1;
-		irq_desc[i].handler = &SIGIO_irq_type;
+		irq_desc[i].handler = &normal_irq_type;
 		enable_irq(i);
 	}
 }
diff --git a/arch/um/kernel/irq_user.c b/arch/um/kernel/irq_user.c
index 6d6f9484b88..c3ccaf24f3e 100644
--- a/arch/um/kernel/irq_user.c
+++ b/arch/um/kernel/irq_user.c
@@ -85,8 +85,6 @@ void sigio_handler(int sig, union uml_pt_regs *regs)
 				next = irq_fd->next;
 				if(irq_fd->freed){
 					free_irq(irq_fd->irq, irq_fd->id);
-					free_irq_by_irq_and_dev(irq_fd->irq,
-								irq_fd->id);
 				}
 			}
 		}
@@ -236,9 +234,15 @@ static void free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg)
 				       (*prev)->fd, pollfds[i].fd);
 				goto out;
 			}
-			memcpy(&pollfds[i], &pollfds[i + 1],
-			       (pollfds_num - i - 1) * sizeof(pollfds[0]));
+
 			pollfds_num--;
+
+			/* This moves the *whole* array after pollfds[i] (though
+			 * it doesn't spot as such)! */
+
+			memmove(&pollfds[i], &pollfds[i + 1],
+			       (pollfds_num - i) * sizeof(pollfds[0]));
+
 			if(last_irq_ptr == &old_fd->next) 
 				last_irq_ptr = prev;
 			*prev = (*prev)->next;
diff --git a/arch/um/kernel/ksyms.c b/arch/um/kernel/ksyms.c
index 78d69dc74b2..99439fa15ef 100644
--- a/arch/um/kernel/ksyms.c
+++ b/arch/um/kernel/ksyms.c
@@ -57,6 +57,7 @@ EXPORT_SYMBOL(copy_to_user_tt);
 EXPORT_SYMBOL(strncpy_from_user_skas);
 EXPORT_SYMBOL(copy_to_user_skas);
 EXPORT_SYMBOL(copy_from_user_skas);
+EXPORT_SYMBOL(clear_user_skas);
 #endif
 EXPORT_SYMBOL(uml_strdup);
 
diff --git a/arch/um/kernel/main.c b/arch/um/kernel/main.c
index a17c49703f9..e59f5815267 100644
--- a/arch/um/kernel/main.c
+++ b/arch/um/kernel/main.c
@@ -24,8 +24,6 @@
 #include "mode.h"
 #include "choose-mode.h"
 #include "uml-config.h"
-#include "irq_user.h"
-#include "time_user.h"
 #include "os.h"
 
 /* Set in set_stklim, which is called from main and __wrap_malloc.
@@ -71,7 +69,7 @@ static __init void do_uml_initcalls(void)
 
 static void last_ditch_exit(int sig)
 {
-	CHOOSE_MODE(kmalloc_ok = 0, (void) 0);
+        kmalloc_ok = 0;
 	signal(SIGINT, SIG_DFL);
 	signal(SIGTERM, SIG_DFL);
 	signal(SIGHUP, SIG_DFL);
@@ -87,7 +85,7 @@ int main(int argc, char **argv, char **envp)
 {
 	char **new_argv;
 	sigset_t mask;
-	int ret, i;
+	int ret, i, err;
 
 	/* Enable all signals except SIGIO - in some environments, we can
 	 * enter with some signals blocked
@@ -160,27 +158,29 @@ int main(int argc, char **argv, char **envp)
 	 */
 	change_sig(SIGPROF, 0);
 
-	/* Reboot */
-	if(ret){
-		int err;
+        /* This signal stuff used to be in the reboot case.  However,
+         * sometimes a SIGVTALRM can come in when we're halting (reproducably
+         * when writing out gcov information, presumably because that takes
+         * some time) and cause a segfault.
+         */
 
-		printf("\n");
+        /* stop timers and set SIG*ALRM to be ignored */
+        disable_timer();
 
-		/* stop timers and set SIG*ALRM to be ignored */
-		disable_timer();
+        /* disable SIGIO for the fds and set SIGIO to be ignored */
+        err = deactivate_all_fds();
+        if(err)
+                printf("deactivate_all_fds failed, errno = %d\n", -err);
 
-		/* disable SIGIO for the fds and set SIGIO to be ignored */
-		err = deactivate_all_fds();
-		if(err)
-			printf("deactivate_all_fds failed, errno = %d\n",
-			       -err);
-
-		/* Let any pending signals fire now.  This ensures
-		 * that they won't be delivered after the exec, when
-		 * they are definitely not expected.
-		 */
-		unblock_signals();
+        /* Let any pending signals fire now.  This ensures
+         * that they won't be delivered after the exec, when
+         * they are definitely not expected.
+         */
+        unblock_signals();
 
+	/* Reboot */
+	if(ret){
+		printf("\n");
 		execvp(new_argv[0], new_argv);
 		perror("Failed to exec kernel");
 		ret = 1;
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index f156661781c..5597bd39e6b 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -53,7 +53,6 @@ static void setup_highmem(unsigned long highmem_start,
 	for(i = 0; i < highmem_len >> PAGE_SHIFT; i++){
 		page = &mem_map[highmem_pfn + i];
 		ClearPageReserved(page);
-		set_bit(PG_highmem, &page->flags);
 		set_page_count(page, 1);
 		__free_page(page);
 	}
@@ -100,12 +99,37 @@ void mem_init(void)
 #endif
 }
 
+/*
+ * Create a page table and place a pointer to it in a middle page
+ * directory entry.
+ */
+static void __init one_page_table_init(pmd_t *pmd)
+{
+	if (pmd_none(*pmd)) {
+		pte_t *pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
+		set_pmd(pmd, __pmd(_KERNPG_TABLE +
+					   (unsigned long) __pa(pte)));
+		if (pte != pte_offset_kernel(pmd, 0))
+			BUG();
+	}
+}
+
+static void __init one_md_table_init(pud_t *pud)
+{
+#ifdef CONFIG_3_LEVEL_PGTABLES
+	pmd_t *pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE);
+	set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
+	if (pmd_table != pmd_offset(pud, 0))
+		BUG();
+#endif
+}
+
 static void __init fixrange_init(unsigned long start, unsigned long end, 
 				 pgd_t *pgd_base)
 {
 	pgd_t *pgd;
+	pud_t *pud;
 	pmd_t *pmd;
-	pte_t *pte;
 	int i, j;
 	unsigned long vaddr;
 
@@ -115,15 +139,12 @@ static void __init fixrange_init(unsigned long start, unsigned long end,
 	pgd = pgd_base + i;
 
 	for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
-		pmd = (pmd_t *)pgd;
+		pud = pud_offset(pgd, vaddr);
+		if (pud_none(*pud))
+			one_md_table_init(pud);
+		pmd = pmd_offset(pud, vaddr);
 		for (; (j < PTRS_PER_PMD) && (vaddr != end); pmd++, j++) {
-			if (pmd_none(*pmd)) {
-				pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
-				set_pmd(pmd, __pmd(_KERNPG_TABLE + 
-						   (unsigned long) __pa(pte)));
-				if (pte != pte_offset_kernel(pmd, 0))
-					BUG();
-			}
+			one_page_table_init(pmd);
 			vaddr += PMD_SIZE;
 		}
 		j = 0;
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 51f8e5a8ac6..1b5ef3e96c7 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -30,7 +30,6 @@
 #include "init.h"
 #include "os.h"
 #include "uml-config.h"
-#include "ptrace_user.h"
 #include "choose-mode.h"
 #include "mode.h"
 #ifdef UML_CONFIG_MODE_SKAS
@@ -131,7 +130,7 @@ int start_fork_tramp(void *thread_arg, unsigned long temp_stack,
 	return(arg.pid);
 }
 
-static int ptrace_child(void *arg)
+static int ptrace_child(void)
 {
 	int ret;
 	int pid = os_getpid(), ppid = getppid();
@@ -160,20 +159,16 @@ static int ptrace_child(void *arg)
 	_exit(ret);
 }
 
-static int start_ptraced_child(void **stack_out)
+static int start_ptraced_child(void)
 {
-	void *stack;
-	unsigned long sp;
 	int pid, n, status;
 	
-	stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
-		     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-	if(stack == MAP_FAILED)
-		panic("check_ptrace : mmap failed, errno = %d", errno);
-	sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
-	pid = clone(ptrace_child, (void *) sp, SIGCHLD, NULL);
+	pid = fork();
+	if(pid == 0)
+		ptrace_child();
+
 	if(pid < 0)
-		panic("check_ptrace : clone failed, errno = %d", errno);
+		panic("check_ptrace : fork failed, errno = %d", errno);
 	CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 	if(n < 0)
 		panic("check_ptrace : wait failed, errno = %d", errno);
@@ -181,7 +176,6 @@ static int start_ptraced_child(void **stack_out)
 		panic("check_ptrace : expected SIGSTOP, got status = %d",
 		      status);
 
-	*stack_out = stack;
 	return(pid);
 }
 
@@ -189,12 +183,12 @@ static int start_ptraced_child(void **stack_out)
  * just avoid using sysemu, not panic, but only if SYSEMU features are broken.
  * So only for SYSEMU features we test mustpanic, while normal host features
  * must work anyway!*/
-static int stop_ptraced_child(int pid, void *stack, int exitcode, int mustpanic)
+static int stop_ptraced_child(int pid, int exitcode, int mustexit)
 {
 	int status, n, ret = 0;
 
 	if(ptrace(PTRACE_CONT, pid, 0, 0) < 0)
-		panic("check_ptrace : ptrace failed, errno = %d", errno);
+		panic("stop_ptraced_child : ptrace failed, errno = %d", errno);
 	CATCH_EINTR(n = waitpid(pid, &status, 0));
 	if(!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) {
 		int exit_with = WEXITSTATUS(status);
@@ -205,15 +199,13 @@ static int stop_ptraced_child(int pid, void *stack, int exitcode, int mustpanic)
 		printk("check_ptrace : child exited with exitcode %d, while "
 		      "expecting %d; status 0x%x", exit_with,
 		      exitcode, status);
-		if (mustpanic)
+		if (mustexit)
 			panic("\n");
 		else
 			printk("\n");
 		ret = -1;
 	}
 
-	if(munmap(stack, PAGE_SIZE) < 0)
-		panic("check_ptrace : munmap failed, errno = %d", errno);
 	return ret;
 }
 
@@ -235,12 +227,11 @@ __uml_setup("nosysemu", nosysemu_cmd_param,
 
 static void __init check_sysemu(void)
 {
-	void *stack;
 	int pid, syscall, n, status, count=0;
 
 	printk("Checking syscall emulation patch for ptrace...");
 	sysemu_supported = 0;
-	pid = start_ptraced_child(&stack);
+	pid = start_ptraced_child();
 
 	if(ptrace(PTRACE_SYSEMU, pid, 0, 0) < 0)
 		goto fail;
@@ -258,7 +249,7 @@ static void __init check_sysemu(void)
 		panic("check_sysemu : failed to modify system "
 		      "call return, errno = %d", errno);
 
-	if (stop_ptraced_child(pid, stack, 0, 0) < 0)
+	if (stop_ptraced_child(pid, 0, 0) < 0)
 		goto fail_stopped;
 
 	sysemu_supported = 1;
@@ -266,7 +257,7 @@ static void __init check_sysemu(void)
 	set_using_sysemu(!force_sysemu_disabled);
 
 	printk("Checking advanced syscall emulation patch for ptrace...");
-	pid = start_ptraced_child(&stack);
+	pid = start_ptraced_child();
 	while(1){
 		count++;
 		if(ptrace(PTRACE_SYSEMU_SINGLESTEP, pid, 0, 0) < 0)
@@ -291,7 +282,7 @@ static void __init check_sysemu(void)
 			break;
 		}
 	}
-	if (stop_ptraced_child(pid, stack, 0, 0) < 0)
+	if (stop_ptraced_child(pid, 0, 0) < 0)
 		goto fail_stopped;
 
 	sysemu_supported = 2;
@@ -302,18 +293,17 @@ static void __init check_sysemu(void)
 	return;
 
 fail:
-	stop_ptraced_child(pid, stack, 1, 0);
+	stop_ptraced_child(pid, 1, 0);
 fail_stopped:
 	printk("missing\n");
 }
 
 void __init check_ptrace(void)
 {
-	void *stack;
 	int pid, syscall, n, status;
 
 	printk("Checking that ptrace can change system call numbers...");
-	pid = start_ptraced_child(&stack);
+	pid = start_ptraced_child();
 
 	if (ptrace(PTRACE_OLDSETOPTIONS, pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0)
 		panic("check_ptrace: PTRACE_SETOPTIONS failed, errno = %d", errno);
@@ -340,7 +330,7 @@ void __init check_ptrace(void)
 			break;
 		}
 	}
-	stop_ptraced_child(pid, stack, 0, 1);
+	stop_ptraced_child(pid, 0, 1);
 	printk("OK\n");
 	check_sysemu();
 }
@@ -372,11 +362,10 @@ void forward_pending_sigio(int target)
 static inline int check_skas3_ptrace_support(void)
 {
 	struct ptrace_faultinfo fi;
-	void *stack;
 	int pid, n, ret = 1;
 
 	printf("Checking for the skas3 patch in the host...");
-	pid = start_ptraced_child(&stack);
+	pid = start_ptraced_child();
 
 	n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi);
 	if (n < 0) {
@@ -391,7 +380,7 @@ static inline int check_skas3_ptrace_support(void)
 	}
 
 	init_registers(pid);
-	stop_ptraced_child(pid, stack, 1, 1);
+	stop_ptraced_child(pid, 1, 1);
 
 	return(ret);
 }
diff --git a/arch/um/kernel/process_kern.c b/arch/um/kernel/process_kern.c
index c1adf7ba3fd..804c6bbdf67 100644
--- a/arch/um/kernel/process_kern.c
+++ b/arch/um/kernel/process_kern.c
@@ -43,7 +43,6 @@
 #include "tlb.h"
 #include "frame_kern.h"
 #include "sigcontext.h"
-#include "2_5compat.h"
 #include "os.h"
 #include "mode.h"
 #include "mode_kern.h"
@@ -55,18 +54,6 @@
  */
 struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
 
-struct task_struct *get_task(int pid, int require)
-{
-        struct task_struct *ret;
-
-        read_lock(&tasklist_lock);
-	ret = find_task_by_pid(pid);
-        read_unlock(&tasklist_lock);
-
-        if(require && (ret == NULL)) panic("get_task couldn't find a task\n");
-        return(ret);
-}
-
 int external_pid(void *t)
 {
 	struct task_struct *task = t ? t : current;
@@ -189,7 +176,6 @@ void default_idle(void)
 
 	while(1){
 		/* endless idle loop with no priority at all */
-		SET_PRI(current);
 
 		/*
 		 * although we are an idle CPU, we do not want to
@@ -212,11 +198,6 @@ int page_size(void)
 	return(PAGE_SIZE);
 }
 
-unsigned long page_mask(void)
-{
-	return(PAGE_MASK);
-}
-
 void *um_virt_to_phys(struct task_struct *task, unsigned long addr, 
 		      pte_t *pte_out)
 {
@@ -349,11 +330,6 @@ char *uml_strdup(char *string)
 	return(new);
 }
 
-void *get_init_task(void)
-{
-	return(&init_thread_union.thread_info.task);
-}
-
 int copy_to_user_proc(void __user *to, void *from, int size)
 {
 	return(copy_to_user(to, from, size));
@@ -480,15 +456,3 @@ unsigned long arch_align_stack(unsigned long sp)
 	return sp & ~0xf;
 }
 #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/ptrace.c b/arch/um/kernel/ptrace.c
index 2b75d8d9ba7..71af4d50389 100644
--- a/arch/um/kernel/ptrace.c
+++ b/arch/um/kernel/ptrace.c
@@ -28,9 +28,9 @@ static inline void set_singlestepping(struct task_struct *child, int on)
         child->thread.singlestep_syscall = 0;
 
 #ifdef SUBARCH_SET_SINGLESTEPPING
-        SUBARCH_SET_SINGLESTEPPING(child, on)
+        SUBARCH_SET_SINGLESTEPPING(child, on);
 #endif
-                }
+}
 
 /*
  * Called by kernel/ptrace.c when detaching..
@@ -83,7 +83,7 @@ long sys_ptrace(long request, long pid, long addr, long data)
 	}
 
 #ifdef SUBACH_PTRACE_SPECIAL
-        SUBARCH_PTRACE_SPECIAL(child,request,addr,data)
+        SUBARCH_PTRACE_SPECIAL(child,request,addr,data);
 #endif
 
 	ret = ptrace_check_attach(child, request == PTRACE_KILL);
@@ -322,11 +322,9 @@ void syscall_trace(union uml_pt_regs *regs, int entryexit)
 					    UPT_SYSCALL_ARG2(regs),
 					    UPT_SYSCALL_ARG3(regs),
 					    UPT_SYSCALL_ARG4(regs));
-		else {
-                        int res = UPT_SYSCALL_RET(regs);
-			audit_syscall_exit(current, AUDITSC_RESULT(res),
-                                           res);
-                }
+		else audit_syscall_exit(current,
+                                        AUDITSC_RESULT(UPT_SYSCALL_RET(regs)),
+                                        UPT_SYSCALL_RET(regs));
 	}
 
 	/* Fake a debug trap */
@@ -356,14 +354,3 @@ void syscall_trace(union uml_pt_regs *regs, int entryexit)
 		current->exit_code = 0;
 	}
 }
-
-/*
- * 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/process_kern.c b/arch/um/kernel/skas/process_kern.c
index ab5d3271da0..fc71ef29578 100644
--- a/arch/um/kernel/skas/process_kern.c
+++ b/arch/um/kernel/skas/process_kern.c
@@ -68,8 +68,11 @@ void new_thread_handler(int sig)
 	 * 0 if it just exits
 	 */
 	n = run_kernel_thread(fn, arg, &current->thread.exec_buf);
-	if(n == 1)
+	if(n == 1){
+		/* Handle any immediate reschedules or signals */
+		interrupt_end();
 		userspace(&current->thread.regs.regs);
+	}
 	else do_exit(0);
 }
 
@@ -96,6 +99,8 @@ void fork_handler(int sig)
 	schedule_tail(current->thread.prev_sched);
 	current->thread.prev_sched = NULL;
 
+	/* Handle any immediate reschedules or signals */
+	interrupt_end();
 	userspace(&current->thread.regs.regs);
 }
 
diff --git a/arch/um/kernel/sysrq.c b/arch/um/kernel/sysrq.c
index e630438f9e7..f80850091e7 100644
--- a/arch/um/kernel/sysrq.c
+++ b/arch/um/kernel/sysrq.c
@@ -3,6 +3,7 @@
  * Licensed under the GPL
  */
 
+#include "linux/config.h"
 #include "linux/sched.h"
 #include "linux/kernel.h"
 #include "linux/module.h"
@@ -12,14 +13,14 @@
 #include "sysrq.h"
 #include "user_util.h"
 
-void show_trace(unsigned long * stack)
+/* Catch non-i386 SUBARCH's. */
+#if !defined(CONFIG_UML_X86) || defined(CONFIG_64BIT)
+void show_trace(struct task_struct *task, unsigned long * stack)
 {
-	/* XXX: Copy the CONFIG_FRAME_POINTER stack-walking backtrace from
-	 * arch/i386/kernel/traps.c, and then move this to sys-i386/sysrq.c.*/
         unsigned long addr;
 
         if (!stack) {
-                stack = (unsigned long*) &stack;
+		stack = (unsigned long*) &stack;
 		WARN_ON(1);
 	}
 
@@ -35,6 +36,7 @@ void show_trace(unsigned long * stack)
         }
         printk("\n");
 }
+#endif
 
 /*
  * stack dumps generator - this is used by arch-independent code.
@@ -44,7 +46,7 @@ void dump_stack(void)
 {
 	unsigned long stack;
 
-	show_trace(&stack);
+	show_trace(current, &stack);
 }
 EXPORT_SYMBOL(dump_stack);
 
@@ -59,7 +61,11 @@ void show_stack(struct task_struct *task, unsigned long *esp)
 	int i;
 
 	if (esp == NULL) {
-		if (task != current) {
+		if (task != current && task != NULL) {
+			/* XXX: Isn't this bogus? I.e. isn't this the
+			 * *userspace* stack of this task? If not so, use this
+			 * even when task == current (as in i386).
+			 */
 			esp = (unsigned long *) KSTK_ESP(task);
 			/* Which one? No actual difference - just coding style.*/
 			//esp = (unsigned long *) PT_REGS_IP(&task->thread.regs);
@@ -77,5 +83,6 @@ void show_stack(struct task_struct *task, unsigned long *esp)
 		printk("%08lx ", *stack++);
 	}
 
-	show_trace(esp);
+	printk("Call Trace: \n");
+	show_trace(current, esp);
 }
diff --git a/arch/um/kernel/trap_kern.c b/arch/um/kernel/trap_kern.c
index 5fca2c61eb9..c20aef12059 100644
--- a/arch/um/kernel/trap_kern.c
+++ b/arch/um/kernel/trap_kern.c
@@ -23,7 +23,6 @@
 #include "kern.h"
 #include "chan_kern.h"
 #include "mconsole_kern.h"
-#include "2_5compat.h"
 #include "mem.h"
 #include "mem_kern.h"
 
@@ -57,10 +56,11 @@ int handle_page_fault(unsigned long address, unsigned long ip,
 	*code_out = SEGV_ACCERR;
 	if(is_write && !(vma->vm_flags & VM_WRITE)) 
 		goto out;
+
+        if(!(vma->vm_flags & (VM_READ | VM_EXEC)))
+                goto out;
+
 	page = address & PAGE_MASK;
-	pgd = pgd_offset(mm, page);
-	pud = pud_offset(pgd, page);
-	pmd = pmd_offset(pud, page);
 	do {
  survive:
 		switch (handle_mm_fault(mm, vma, address, is_write)){
@@ -106,33 +106,6 @@ out_of_memory:
 	goto out;
 }
 
-LIST_HEAD(physmem_remappers);
-
-void register_remapper(struct remapper *info)
-{
-	list_add(&info->list, &physmem_remappers);
-}
-
-static int check_remapped_addr(unsigned long address, int is_write)
-{
-	struct remapper *remapper;
-	struct list_head *ele;
-	__u64 offset;
-	int fd;
-
-	fd = phys_mapping(__pa(address), &offset);
-	if(fd == -1)
-		return(0);
-
-	list_for_each(ele, &physmem_remappers){
-		remapper = list_entry(ele, struct remapper, list);
-		if((*remapper->proc)(fd, address, is_write, offset))
-			return(1);
-	}
-
-	return(0);
-}
-
 /*
  * We give a *copy* of the faultinfo in the regs to segv.
  * This must be done, since nesting SEGVs could overwrite
@@ -151,8 +124,6 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void *sc)
                 flush_tlb_kernel_vm();
                 return(0);
         }
-	else if(check_remapped_addr(address & PAGE_MASK, is_write))
-		return(0);
 	else if(current->mm == NULL)
 		panic("Segfault with no mm");
 	err = handle_page_fault(address, ip, is_write, is_user, &si.si_code);
diff --git a/arch/um/kernel/tt/Makefile b/arch/um/kernel/tt/Makefile
index c3faea21a99..3fd2554e60b 100644
--- a/arch/um/kernel/tt/Makefile
+++ b/arch/um/kernel/tt/Makefile
@@ -3,10 +3,6 @@
 # Licensed under the GPL
 #
 
-extra-y := unmap_fin.o
-targets := unmap.o
-clean-files := unmap_tmp.o
-
 obj-y = exec_kern.o exec_user.o gdb.o ksyms.o mem.o mem_user.o process_kern.o \
 	syscall_kern.o syscall_user.o time.o tlb.o tracer.o trap_user.o \
 	uaccess.o uaccess_user.o
@@ -16,14 +12,3 @@ obj-$(CONFIG_PT_PROXY) += gdb_kern.o ptproxy/
 USER_OBJS := gdb.o time.o tracer.o
 
 include arch/um/scripts/Makefile.rules
-
-UNMAP_CFLAGS := $(patsubst -pg -DPROFILING,,$(USER_CFLAGS))
-UNMAP_CFLAGS := $(patsubst -fprofile-arcs -ftest-coverage,,$(UNMAP_CFLAGS))
-
-#XXX: partially copied from arch/um/scripts/Makefile.rules
-$(obj)/unmap.o: c_flags = -Wp,-MD,$(depfile) $(UNMAP_CFLAGS)
-
-$(obj)/unmap_fin.o : $(obj)/unmap.o
-	$(LD) -r -o $(obj)/unmap_tmp.o $< $(shell $(CC) -print-file-name=libc.a)
-	$(OBJCOPY) $(obj)/unmap_tmp.o $@ -G switcheroo
-
diff --git a/arch/um/kernel/tt/ksyms.c b/arch/um/kernel/tt/ksyms.c
index 92ec85d67c7..84a9385a8fe 100644
--- a/arch/um/kernel/tt/ksyms.c
+++ b/arch/um/kernel/tt/ksyms.c
@@ -12,6 +12,7 @@ EXPORT_SYMBOL(__do_copy_to_user);
 EXPORT_SYMBOL(__do_strncpy_from_user);
 EXPORT_SYMBOL(__do_strnlen_user); 
 EXPORT_SYMBOL(__do_clear_user);
+EXPORT_SYMBOL(clear_user_tt);
 
 EXPORT_SYMBOL(tracing_pid);
 EXPORT_SYMBOL(honeypot);
diff --git a/arch/um/kernel/tt/process_kern.c b/arch/um/kernel/tt/process_kern.c
index df810ca8fc1..776310fd5b8 100644
--- a/arch/um/kernel/tt/process_kern.c
+++ b/arch/um/kernel/tt/process_kern.c
@@ -32,10 +32,6 @@ void *switch_to_tt(void *prev, void *next, void *last)
 	unsigned long flags;
 	int err, vtalrm, alrm, prof, cpu;
 	char c;
-	/* jailing and SMP are incompatible, so this doesn't need to be 
-	 * made per-cpu 
-	 */
-	static int reading;
 
 	from = prev;
 	to = next;
@@ -59,13 +55,11 @@ void *switch_to_tt(void *prev, void *next, void *last)
 	c = 0;
 	set_current(to);
 
-	reading = 0;
 	err = os_write_file(to->thread.mode.tt.switch_pipe[1], &c, sizeof(c));
 	if(err != sizeof(c))
 		panic("write of switch_pipe failed, err = %d", -err);
 
-	reading = 1;
-        if(from->thread.mode.tt.switch_pipe[0] == -1)
+	if(from->thread.mode.tt.switch_pipe[0] == -1)
 		os_kill_process(os_getpid(), 0);
 
 	err = os_read_file(from->thread.mode.tt.switch_pipe[0], &c, sizeof(c));
diff --git a/arch/um/kernel/tt/unmap.c b/arch/um/kernel/tt/unmap.c
deleted file mode 100644
index 3f7aecdbe53..00000000000
--- a/arch/um/kernel/tt/unmap.c
+++ /dev/null
@@ -1,31 +0,0 @@
-/* 
- * Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#include <sys/mman.h>
-
-int switcheroo(int fd, int prot, void *from, void *to, int size)
-{
-	if(munmap(to, size) < 0){
-		return(-1);
-	}
-	if(mmap(to, size, prot,	MAP_SHARED | MAP_FIXED, fd, 0) != to){
-		return(-1);
-	}
-	if(munmap(from, size) < 0){
-		return(-1);
-	}
-	return(0);
-}
-
-/*
- * 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/um_arch.c b/arch/um/kernel/um_arch.c
index 4d10ec372a6..8736d098f0e 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -26,7 +26,6 @@
 #include "asm/setup.h"
 #include "ubd_user.h"
 #include "asm/current.h"
-#include "asm/setup.h"
 #include "user_util.h"
 #include "kern_util.h"
 #include "kern.h"
@@ -111,12 +110,6 @@ struct seq_operations cpuinfo_op = {
 	.show	= show_cpuinfo,
 };
 
-pte_t * __bad_pagetable(void)
-{
-	panic("Someone should implement __bad_pagetable");
-	return(NULL);
-}
-
 /* Set in linux_main */
 unsigned long host_task_size;
 unsigned long task_size;
diff --git a/arch/um/kernel/uml.lds.S b/arch/um/kernel/uml.lds.S
index 76eadb30918..61dfd4fef75 100644
--- a/arch/um/kernel/uml.lds.S
+++ b/arch/um/kernel/uml.lds.S
@@ -14,19 +14,10 @@ SECTIONS
   /* Used in arch/um/kernel/mem.c. Any memory between START and __binary_start
    * is remapped.*/
   __binary_start = .;
-#ifdef MODE_TT
-  .thread_private : {
-    __start_thread_private = .;
-    errno = .;
-    . += 4;
-    arch/um/kernel/tt/unmap_fin.o (.data)
-    __end_thread_private = .;
-  }
-  . = ALIGN(4096);
-  .remap : { arch/um/kernel/tt/unmap_fin.o (.text) }
 
-  /* We want it only if we are in MODE_TT. In both cases, however, when MODE_TT
-   * is off the resulting binary segfaults.*/
+#ifdef MODE_TT
+  .remap_data : { arch/um/sys-SUBARCH/unmap_fin.o (.data .bss) }
+  .remap : { arch/um/sys-SUBARCH/unmap_fin.o (.text) }
 
   . = ALIGN(4096);		/* Init code and data */
 #endif
@@ -73,6 +64,8 @@ SECTIONS
 
   .got           : { *(.got.plt) *(.got) }
   .dynamic       : { *(.dynamic) }
+  .tdata	  : { *(.tdata .tdata.* .gnu.linkonce.td.*) }
+  .tbss		  : { *(.tbss .tbss.* .gnu.linkonce.tb.*) *(.tcommon) }
   /* We want the small data sections together, so single-instruction offsets
      can access them all, and initialized data all before uninitialized, so
      we can shorten the on-disk segment size.  */
diff --git a/arch/um/os-Linux/elf_aux.c b/arch/um/os-Linux/elf_aux.c
index 9aee0b62ebc..f0d6060e3e5 100644
--- a/arch/um/os-Linux/elf_aux.c
+++ b/arch/um/os-Linux/elf_aux.c
@@ -45,7 +45,11 @@ __init void scan_elf_aux( char **envp)
 				elf_aux_hwcap = auxv->a_un.a_val;
 				break;
 			case AT_PLATFORM:
-				elf_aux_platform = auxv->a_un.a_ptr;
+                                /* elf.h removed the pointer elements from
+                                 * a_un, so we have to use a_val, which is
+                                 * all that's left.
+                                 */
+				elf_aux_platform = (char *) auxv->a_un.a_val;
 				break;
 			case AT_PAGESZ:
 				page_size = auxv->a_un.a_val;
diff --git a/arch/um/os-Linux/file.c b/arch/um/os-Linux/file.c
index 77d4066d1af..fd45bb26090 100644
--- a/arch/um/os-Linux/file.c
+++ b/arch/um/os-Linux/file.c
@@ -363,7 +363,7 @@ int os_write_file(int fd, const void *buf, int len)
 		       (int (*)(int, void *, int)) write, copy_to_user_proc));
 }
 
-int os_file_size(char *file, long long *size_out)
+int os_file_size(char *file, unsigned long long *size_out)
 {
 	struct uml_stat buf;
 	int err;
diff --git a/arch/um/scripts/Makefile.rules b/arch/um/scripts/Makefile.rules
index 0b2491883d9..7459d09c233 100644
--- a/arch/um/scripts/Makefile.rules
+++ b/arch/um/scripts/Makefile.rules
@@ -10,11 +10,17 @@ USER_OBJS := $(foreach file,$(USER_OBJS),$(obj)/$(file))
 $(USER_OBJS) : c_flags = -Wp,-MD,$(depfile) $(USER_CFLAGS) \
 	$(CFLAGS_$(notdir $@))
 
+# The stubs and unmap.o can't try to call mcount or update basic block data
+define unprofile
+	$(patsubst -pg,,$(patsubst -fprofile-arcs -ftest-coverage,,$(1)))
+endef
+
+
 quiet_cmd_make_link = SYMLINK $@
 cmd_make_link       = ln -sf $(srctree)/arch/$(SUBARCH)/$($(notdir $@)-dir)/$(notdir $@) $@
 
 # this needs to be before the foreach, because targets does not accept
-# complete paths like $(obj)/$(f). To make sure this works, use a := assignment,
+# complete paths like $(obj)/$(f). To make sure this works, use a := assignment
 # or we will get $(obj)/$(f) in the "targets" value.
 # Also, this forces you to use the := syntax when assigning to targets.
 # Otherwise the line below will cause an infinite loop (if you don't know why,
diff --git a/arch/um/scripts/Makefile.unmap b/arch/um/scripts/Makefile.unmap
new file mode 100644
index 00000000000..37a8f976529
--- /dev/null
+++ b/arch/um/scripts/Makefile.unmap
@@ -0,0 +1,22 @@
+clean-files += unmap_tmp.o unmap_fin.o unmap.o
+
+ifdef CONFIG_MODE_TT
+
+#Always build unmap_fin.o
+extra-y += unmap_fin.o
+#Do dependency tracking for unmap.o (it will be always built, but won't get the tracking unless we use this).
+targets += unmap.o
+
+#XXX: partially copied from arch/um/scripts/Makefile.rules
+$(obj)/unmap.o: _c_flags = $(call unprofile,$(CFLAGS))
+
+quiet_cmd_wrapld = LD      $@
+define cmd_wrapld
+	$(LD) -r -o $(obj)/unmap_tmp.o $< $(shell $(CC) -print-file-name=libc.a); \
+	$(OBJCOPY) $(obj)/unmap_tmp.o $@ -G switcheroo
+endef
+
+$(obj)/unmap_fin.o : $(obj)/unmap.o FORCE
+	$(call if_changed,wrapld)
+
+endif
diff --git a/arch/um/sys-i386/Makefile b/arch/um/sys-i386/Makefile
index fcd67c3414e..095bcdb0b9c 100644
--- a/arch/um/sys-i386/Makefile
+++ b/arch/um/sys-i386/Makefile
@@ -9,6 +9,8 @@ USER_OBJS := bugs.o ptrace_user.o sigcontext.o fault.o
 
 SYMLINKS = bitops.c semaphore.c highmem.c module.c
 
+include arch/um/scripts/Makefile.rules
+
 bitops.c-dir = lib
 semaphore.c-dir = kernel
 highmem.c-dir = mm
@@ -16,4 +18,4 @@ module.c-dir = kernel
 
 subdir- := util
 
-include arch/um/scripts/Makefile.rules
+include arch/um/scripts/Makefile.unmap
diff --git a/arch/um/sys-i386/delay.c b/arch/um/sys-i386/delay.c
index e9892eef51c..2c11b9770e8 100644
--- a/arch/um/sys-i386/delay.c
+++ b/arch/um/sys-i386/delay.c
@@ -1,5 +1,7 @@
-#include "linux/delay.h"
-#include "asm/param.h"
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <asm/param.h>
 
 void __delay(unsigned long time)
 {
@@ -20,13 +22,19 @@ void __udelay(unsigned long usecs)
 	int i, n;
 
 	n = (loops_per_jiffy * HZ * usecs) / MILLION;
-	for(i=0;i<n;i++) ;
+        for(i=0;i<n;i++)
+                cpu_relax();
 }
 
+EXPORT_SYMBOL(__udelay);
+
 void __const_udelay(unsigned long usecs)
 {
 	int i, n;
 
 	n = (loops_per_jiffy * HZ * usecs) / MILLION;
-	for(i=0;i<n;i++) ;
+        for(i=0;i<n;i++)
+                cpu_relax();
 }
+
+EXPORT_SYMBOL(__const_udelay);
diff --git a/arch/um/sys-i386/sysrq.c b/arch/um/sys-i386/sysrq.c
index 281fc7b8ca0..e3706d15c4f 100644
--- a/arch/um/sys-i386/sysrq.c
+++ b/arch/um/sys-i386/sysrq.c
@@ -3,12 +3,15 @@
  * Licensed under the GPL
  */
 
+#include "linux/config.h"
 #include "linux/kernel.h"
 #include "linux/smp.h"
 #include "linux/sched.h"
+#include "linux/kallsyms.h"
 #include "asm/ptrace.h"
 #include "sysrq.h"
 
+/* This is declared by <linux/sched.h> */
 void show_regs(struct pt_regs *regs)
 {
         printk("\n");
@@ -31,5 +34,80 @@ void show_regs(struct pt_regs *regs)
 	       0xffff & PT_REGS_DS(regs), 
 	       0xffff & PT_REGS_ES(regs));
 
-        show_trace((unsigned long *) &regs);
+        show_trace(NULL, (unsigned long *) &regs);
 }
+
+/* Copied from i386. */
+static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
+{
+	return	p > (void *)tinfo &&
+		p < (void *)tinfo + THREAD_SIZE - 3;
+}
+
+/* Adapted from i386 (we also print the address we read from). */
+static inline unsigned long print_context_stack(struct thread_info *tinfo,
+				unsigned long *stack, unsigned long ebp)
+{
+	unsigned long addr;
+
+#ifdef CONFIG_FRAME_POINTER
+	while (valid_stack_ptr(tinfo, (void *)ebp)) {
+		addr = *(unsigned long *)(ebp + 4);
+		printk("%08lx:  [<%08lx>]", ebp + 4, addr);
+		print_symbol(" %s", addr);
+		printk("\n");
+		ebp = *(unsigned long *)ebp;
+	}
+#else
+	while (valid_stack_ptr(tinfo, stack)) {
+		addr = *stack;
+		if (__kernel_text_address(addr)) {
+			printk("%08lx:  [<%08lx>]", (unsigned long) stack, addr);
+			print_symbol(" %s", addr);
+			printk("\n");
+		}
+		stack++;
+	}
+#endif
+	return ebp;
+}
+
+void show_trace(struct task_struct* task, unsigned long * stack)
+{
+	unsigned long ebp;
+	struct thread_info *context;
+
+	/* Turn this into BUG_ON if possible. */
+	if (!stack) {
+		stack = (unsigned long*) &stack;
+		printk("show_trace: got NULL stack, implicit assumption task == current");
+		WARN_ON(1);
+	}
+
+	if (!task)
+		task = current;
+
+	if (task != current) {
+		//ebp = (unsigned long) KSTK_EBP(task);
+		/* Which one? No actual difference - just coding style.*/
+		ebp = (unsigned long) PT_REGS_EBP(&task->thread.regs);
+	} else {
+		asm ("movl %%ebp, %0" : "=r" (ebp) : );
+	}
+
+	context = (struct thread_info *)
+		((unsigned long)stack & (~(THREAD_SIZE - 1)));
+	print_context_stack(context, stack, ebp);
+
+	/*while (((long) stack & (THREAD_SIZE-1)) != 0) {
+		addr = *stack;
+		if (__kernel_text_address(addr)) {
+			printk("%08lx:	[<%08lx>]", (unsigned long) stack, addr);
+			print_symbol(" %s", addr);
+			printk("\n");
+		}
+		stack++;
+	}*/
+	printk("\n");
+}
+
diff --git a/arch/um/sys-i386/unmap.c b/arch/um/sys-i386/unmap.c
new file mode 100644
index 00000000000..136875263d2
--- /dev/null
+++ b/arch/um/sys-i386/unmap.c
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include <linux/mman.h>
+#include <asm/unistd.h>
+
+static int errno;
+
+static inline _syscall2(int,munmap,void *,start,size_t,len)
+static inline _syscall6(void *,mmap2,void *,addr,size_t,len,int,prot,int,flags,int,fd,off_t,offset)
+int switcheroo(int fd, int prot, void *from, void *to, int size)
+{
+	if(munmap(to, size) < 0){
+		return(-1);
+	}
+	if(mmap2(to, size, prot, MAP_SHARED | MAP_FIXED, fd, 0) != to){
+		return(-1);
+	}
+	if(munmap(from, size) < 0){
+		return(-1);
+	}
+	return(0);
+}
diff --git a/arch/um/sys-ppc/sysrq.c b/arch/um/sys-ppc/sysrq.c
index 82d6e9335bb..2f816f1a0ff 100644
--- a/arch/um/sys-ppc/sysrq.c
+++ b/arch/um/sys-ppc/sysrq.c
@@ -27,17 +27,5 @@ void show_regs(struct pt_regs_subarch *regs)
                 0xffff & regs->xds, 0xffff & regs->xes);
 #endif
 
-        show_trace(&regs->gpr[1]);
+        show_trace(current, &regs->gpr[1]);
 }
-
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/sys-x86_64/Makefile b/arch/um/sys-x86_64/Makefile
index 3d7da911cc8..2bc6f684901 100644
--- a/arch/um/sys-x86_64/Makefile
+++ b/arch/um/sys-x86_64/Makefile
@@ -14,11 +14,11 @@ obj-$(CONFIG_MODULES) += module.o um_module.o
 
 USER_OBJS := ptrace_user.o sigcontext.o
 
-include arch/um/scripts/Makefile.rules
-
 SYMLINKS = bitops.c csum-copy.S csum-partial.c csum-wrappers.c memcpy.S \
 	semaphore.c thunk.S module.c
 
+include arch/um/scripts/Makefile.rules
+
 bitops.c-dir = lib
 csum-copy.S-dir = lib
 csum-partial.c-dir = lib
@@ -28,6 +28,6 @@ semaphore.c-dir = kernel
 thunk.S-dir = lib
 module.c-dir = kernel
 
-CFLAGS_csum-partial.o := -Dcsum_partial=arch_csum_partial
-
 subdir- := util
+
+include arch/um/scripts/Makefile.unmap
diff --git a/arch/um/sys-x86_64/delay.c b/arch/um/sys-x86_64/delay.c
index 651332aeec2..137f4446b43 100644
--- a/arch/um/sys-x86_64/delay.c
+++ b/arch/um/sys-x86_64/delay.c
@@ -5,40 +5,37 @@
  * Licensed under the GPL
  */
 
-#include "linux/delay.h"
-#include "asm/processor.h"
-#include "asm/param.h"
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <asm/processor.h>
+#include <asm/param.h>
 
 void __delay(unsigned long loops)
 {
 	unsigned long i;
 
-	for(i = 0; i < loops; i++) ;
+        for(i = 0; i < loops; i++)
+                cpu_relax();
 }
 
 void __udelay(unsigned long usecs)
 {
-	int i, n;
+	unsigned long i, n;
 
 	n = (loops_per_jiffy * HZ * usecs) / MILLION;
-	for(i=0;i<n;i++) ;
+        for(i=0;i<n;i++)
+                cpu_relax();
 }
 
+EXPORT_SYMBOL(__udelay);
+
 void __const_udelay(unsigned long usecs)
 {
-	int i, n;
+	unsigned long i, n;
 
 	n = (loops_per_jiffy * HZ * usecs) / MILLION;
-	for(i=0;i<n;i++) ;
+        for(i=0;i<n;i++)
+                cpu_relax();
 }
 
-/*
- * 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:
- */
+EXPORT_SYMBOL(__const_udelay);
diff --git a/arch/um/sys-x86_64/ksyms.c b/arch/um/sys-x86_64/ksyms.c
index a27f0ee6a4f..85927380820 100644
--- a/arch/um/sys-x86_64/ksyms.c
+++ b/arch/um/sys-x86_64/ksyms.c
@@ -16,5 +16,4 @@ EXPORT_SYMBOL(__up_wakeup);
 EXPORT_SYMBOL(__memcpy);
 
 /* Networking helper routines. */
-/*EXPORT_SYMBOL(csum_partial_copy_from);
-EXPORT_SYMBOL(csum_partial_copy_to);*/
+EXPORT_SYMBOL(ip_compute_csum);
diff --git a/arch/um/sys-x86_64/ptrace.c b/arch/um/sys-x86_64/ptrace.c
index b593bb256f2..74eee5c7c6d 100644
--- a/arch/um/sys-x86_64/ptrace.c
+++ b/arch/um/sys-x86_64/ptrace.c
@@ -5,10 +5,11 @@
  */
 
 #define __FRAME_OFFSETS
-#include "asm/ptrace.h"
-#include "linux/sched.h"
-#include "linux/errno.h"
-#include "asm/elf.h"
+#include <asm/ptrace.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <asm/uaccess.h>
+#include <asm/elf.h>
 
 /* XXX x86_64 */
 unsigned long not_ss;
diff --git a/arch/um/sys-x86_64/syscalls.c b/arch/um/sys-x86_64/syscalls.c
index dd9914642b8..6f44f40204e 100644
--- a/arch/um/sys-x86_64/syscalls.c
+++ b/arch/um/sys-x86_64/syscalls.c
@@ -15,6 +15,7 @@
 #include "asm/unistd.h"
 #include "asm/prctl.h" /* XXX This should get the constants from libc */
 #include "choose-mode.h"
+#include "kern.h"
 
 asmlinkage long sys_uname64(struct new_utsname __user * name)
 {
@@ -132,23 +133,27 @@ static long arch_prctl_tt(int code, unsigned long addr)
 
 #ifdef CONFIG_MODE_SKAS
 
+/* XXX: Must also call arch_prctl in the host, beside saving the segment bases! */
 static long arch_prctl_skas(int code, unsigned long addr)
 {
 	long ret = 0;
 
 	switch(code){
-	case ARCH_SET_GS:
-		current->thread.regs.regs.skas.regs[GS_BASE / sizeof(unsigned long)] = addr;
-		break;
 	case ARCH_SET_FS:
 		current->thread.regs.regs.skas.regs[FS_BASE / sizeof(unsigned long)] = addr;
 		break;
+	case ARCH_SET_GS:
+		current->thread.regs.regs.skas.regs[GS_BASE / sizeof(unsigned long)] = addr;
+		break;
 	case ARCH_GET_FS:
-		ret = put_user(current->thread.regs.regs.skas.regs[GS / sizeof(unsigned long)], &addr);
+		ret = put_user(current->thread.regs.regs.skas.
+				regs[FS_BASE / sizeof(unsigned long)],
+				(unsigned long __user *)addr);
 	        break;
 	case ARCH_GET_GS:
-		ret = put_user(current->thread.regs.regs.skas.regs[FS / sizeof(unsigned \
-long)], &addr);
+		ret = put_user(current->thread.regs.regs.skas.
+				regs[GS_BASE / sizeof(unsigned long)],
+				(unsigned long __user *)addr);
 	        break;
 	default:
 		ret = -EINVAL;
diff --git a/arch/um/sys-x86_64/sysrq.c b/arch/um/sys-x86_64/sysrq.c
index ddf74691a61..d0a25af19a5 100644
--- a/arch/um/sys-x86_64/sysrq.c
+++ b/arch/um/sys-x86_64/sysrq.c
@@ -36,14 +36,5 @@ void __show_regs(struct pt_regs * regs)
 void show_regs(struct pt_regs *regs)
 {
 	__show_regs(regs);
-	show_trace((unsigned long *) &regs);
+	show_trace(current, (unsigned long *) &regs);
 }
-
-/* 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/sys-x86_64/unmap.c b/arch/um/sys-x86_64/unmap.c
new file mode 100644
index 00000000000..bc7094cce47
--- /dev/null
+++ b/arch/um/sys-x86_64/unmap.c
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include <linux/mman.h>
+#include <asm/unistd.h>
+
+static int errno;
+
+static inline _syscall2(int,munmap,void *,start,size_t,len)
+static inline _syscall6(void *,mmap,void *,addr,size_t,len,int,prot,int,flags,int,fd,off_t,offset)
+int switcheroo(int fd, int prot, void *from, void *to, int size)
+{
+	if(munmap(to, size) < 0){
+		return(-1);
+	}
+	if(mmap(to, size, prot, MAP_SHARED | MAP_FIXED, fd, 0) != to){
+		return(-1);
+	}
+	if(munmap(from, size) < 0){
+		return(-1);
+	}
+	return(0);
+}
diff --git a/arch/um/sys-x86_64/user-offsets.c b/arch/um/sys-x86_64/user-offsets.c
index 5e14792e483..513d17ceafd 100644
--- a/arch/um/sys-x86_64/user-offsets.c
+++ b/arch/um/sys-x86_64/user-offsets.c
@@ -3,6 +3,14 @@
 #include <signal.h>
 #define __FRAME_OFFSETS
 #include <asm/ptrace.h>
+#include <asm/types.h>
+/* For some reason, x86_64 defines u64 and u32 only in <pci/types.h>, which I
+ * refuse to include here, even though they're used throughout the headers.
+ * These are used in asm/user.h, and that include can't be avoided because of
+ * the sizeof(struct user_regs_struct) below.
+ */
+typedef __u64 u64;
+typedef __u32 u32;
 #include <asm/user.h>
 
 #define DEFINE(sym, val) \