Pull release into acpica branch

83 files changed, 1854 insertions, 1141 deletions

diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index 1eb21de..5982fe2 100644
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -22,10 +22,6 @@ config SBUS
 config PCI
 	bool
 
-config UID16
-	bool
-	default y
-
 config GENERIC_CALIBRATE_DELAY
 	bool
 	default y
@@ -39,12 +35,12 @@ menu "UML-specific options"
 
 config MODE_TT
 	bool "Tracing thread support"
-	default y
+	default n
 	help
 	This option controls whether tracing thread support is compiled
-	into UML.  Normally, this should be set to Y.  If you intend to
-	use only skas mode (and the host has the skas patch applied to it),
-	then it is OK to say N here.
+	into UML.  This option is largely obsolete, given that skas0 provides
+	skas security and performance without needing to patch the host.
+	It is safe to say 'N' here.
 
 config STATIC_LINK
 	bool "Force a static link"
@@ -83,7 +79,7 @@ config KERNEL_HALF_GIGS
         of physical memory.
 
 config MODE_SKAS
-	bool "Separate Kernel Address Space support"
+	bool "Separate Kernel Address Space support" if MODE_TT
 	default y
 	help
 	This option controls whether skas (separate kernel address space)
@@ -147,6 +143,7 @@ config HOSTFS
 
 config HPPFS
 	tristate "HoneyPot ProcFS (EXPERIMENTAL)"
+	depends on EXPERIMENTAL
 	help
 	hppfs (HoneyPot ProcFS) is a filesystem which allows UML /proc
 	entries to be overridden, removed, or fabricated from the host.
@@ -159,10 +156,6 @@ config HPPFS
 	You only need this if you are setting up a UML honeypot.  Otherwise,
 	it is safe to say 'N' here.
 
-	If you are actively using it, please report any problems, since it's
-	getting fixed. In this moment, it is experimental on 2.6 (it works on
-	2.4).
-
 config MCONSOLE
 	bool "Management console"
 	default y
@@ -247,8 +240,16 @@ config NEST_LEVEL
         Only change this if you are running nested UMLs.
 
 config HIGHMEM
-	bool "Highmem support"
-	depends on !64BIT
+	bool "Highmem support (EXPERIMENTAL)"
+	depends on !64BIT && EXPERIMENTAL
+	default n
+	help
+	This was used to allow UML to run with big amounts of memory.
+	Currently it is unstable, so if unsure say N.
+
+	To use big amounts of memory, it is recommended to disable TT mode (i.e.
+	CONFIG_MODE_TT) and enable static linking (i.e. CONFIG_STATIC_LINK) -
+	this should allow the guest to use up to 2.75G of memory.
 
 config KERNEL_STACK_ORDER
 	int "Kernel stack size order"
@@ -273,17 +274,13 @@ endmenu
 
 source "init/Kconfig"
 
-source "net/Kconfig"
-
-source "drivers/base/Kconfig"
+source "drivers/block/Kconfig"
 
 source "arch/um/Kconfig.char"
 
-source "drivers/block/Kconfig"
+source "drivers/base/Kconfig"
 
-config NETDEVICES
-	bool
-	default NET
+source "net/Kconfig"
 
 source "arch/um/Kconfig.net"
 
diff --git a/arch/um/Kconfig.i386 b/arch/um/Kconfig.i386
index c71b39a..ef79ed2 100644
--- a/arch/um/Kconfig.i386
+++ b/arch/um/Kconfig.i386
@@ -22,13 +22,17 @@ config TOP_ADDR
  	default 0x80000000 if HOST_2G_2G
 
 config 3_LEVEL_PGTABLES
-	bool "Three-level pagetables"
+	bool "Three-level pagetables (EXPERIMENTAL)"
 	default n
+	depends on EXPERIMENTAL
 	help
 	Three-level pagetables will let UML have more than 4G of physical
 	memory.  All the memory that can't be mapped directly will be treated
 	as high memory.
 
+	However, this it experimental on 32-bit architectures, so if unsure say
+	N (on x86-64 it's automatically enabled, instead, as it's safe there).
+
 config STUB_CODE
 	hex
 	default 0xbfffe000
diff --git a/arch/um/Makefile b/arch/um/Makefile
index 1b12fee..6430a63 100644
--- a/arch/um/Makefile
+++ b/arch/um/Makefile
@@ -32,7 +32,7 @@ um-modes-$(CONFIG_MODE_TT) += tt
 um-modes-$(CONFIG_MODE_SKAS) += skas
 
 MODE_INCLUDE	+= $(foreach mode,$(um-modes-y),\
-		   -I$(srctree)/$(ARCH_DIR)/kernel/$(mode)/include)
+		   -I$(srctree)/$(ARCH_DIR)/include/$(mode))
 
 MAKEFILES-INCL	+= $(foreach mode,$(um-modes-y),\
 		   $(srctree)/$(ARCH_DIR)/Makefile-$(mode))
@@ -67,7 +67,8 @@ USER_CFLAGS := $(patsubst -D__KERNEL__,,$(USER_CFLAGS)) $(ARCH_INCLUDE) \
 # in CFLAGS.  Otherwise, it would cause ld to complain about the two different
 # errnos.
 
-CFLAGS += -Derrno=kernel_errno -Dsigprocmask=kernel_sigprocmask
+CFLAGS += -Derrno=kernel_errno -Dsigprocmask=kernel_sigprocmask \
+	-Dmktime=kernel_mktime
 CFLAGS += $(call cc-option,-fno-unit-at-a-time,)
 
 include $(srctree)/$(ARCH_DIR)/Makefile-$(SUBARCH)
@@ -189,6 +190,12 @@ define filechk_umlconfig
 	sed 's/ CONFIG/ UML_CONFIG/'
 endef
 
+$(ARCH_DIR)/include/uml-config.h : include/linux/autoconf.h
+	$(call filechk,umlconfig)
+
+$(ARCH_DIR)/user-offsets.s: $(ARCH_DIR)/sys-$(SUBARCH)/user-offsets.c
+	$(CC) $(USER_CFLAGS) -S -o $@ $<
+
 define filechk_gen-asm-offsets
         (set -e; \
          echo "/*"; \
@@ -202,24 +209,13 @@ define filechk_gen-asm-offsets
          echo ""; )
 endef
 
-$(ARCH_DIR)/include/uml-config.h : include/linux/autoconf.h
-	$(call filechk,umlconfig)
-
-$(ARCH_DIR)/user-offsets.s: $(ARCH_DIR)/sys-$(SUBARCH)/user-offsets.c
-	$(CC) $(USER_CFLAGS) -S -o $@ $<
-
 $(ARCH_DIR)/include/user_constants.h: $(ARCH_DIR)/user-offsets.s
 	$(call filechk,gen-asm-offsets)
 
 CLEAN_FILES += $(ARCH_DIR)/user-offsets.s
 
-$(ARCH_DIR)/kernel-offsets.s: $(ARCH_DIR)/sys-$(SUBARCH)/kernel-offsets.c \
-				   archprepare
-	$(CC) $(CFLAGS) $(NOSTDINC_FLAGS) $(CPPFLAGS) -S -o $@ $<
-
-$(ARCH_DIR)/include/kern_constants.h: $(ARCH_DIR)/kernel-offsets.s
-	$(call filechk,gen-asm-offsets)
-
-CLEAN_FILES += $(ARCH_DIR)/kernel-offsets.s
+$(ARCH_DIR)/include/kern_constants.h:
+	@echo '  SYMLINK $@'
+	$(Q) ln -sf ../../../include/asm-um/asm-offsets.h $@
 
 export SUBARCH USER_CFLAGS OS
diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index cd13b91..ab0d0b1 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -186,9 +186,6 @@ static void tty_receive_char(struct tty_struct *tty, char ch)
 		}
 	}
 
-	if((tty->flip.flag_buf_ptr == NULL) ||
-	   (tty->flip.char_buf_ptr == NULL))
-		return;
 	tty_insert_flip_char(tty, ch, TTY_NORMAL);
 }
 
@@ -653,8 +650,7 @@ void chan_interrupt(struct list_head *chans, struct work_struct *task,
 		chan = list_entry(ele, struct chan, list);
 		if(!chan->input || (chan->ops->read == NULL)) continue;
 		do {
-			if((tty != NULL) &&
-			   (tty->flip.count >= TTY_FLIPBUF_SIZE)){
+			if (tty && !tty_buffer_request_room(tty, 1)) {
 				schedule_delayed_work(task, 1);
 				goto out;
 			}
diff --git a/arch/um/drivers/daemon_kern.c b/arch/um/drivers/daemon_kern.c
index 30d285b..507e3cb 100644
--- a/arch/um/drivers/daemon_kern.c
+++ b/arch/um/drivers/daemon_kern.c
@@ -31,6 +31,10 @@ void daemon_init(struct net_device *dev, void *data)
 	dpri->fd = -1;
 	dpri->control = -1;
 	dpri->dev = dev;
+	/* We will free this pointer. If it contains crap we're burned. */
+	dpri->ctl_addr = NULL;
+	dpri->data_addr = NULL;
+	dpri->local_addr = NULL;
 
 	printk("daemon backend (uml_switch version %d) - %s:%s", 
 	       SWITCH_VERSION, dpri->sock_type, dpri->ctl_sock);
diff --git a/arch/um/drivers/daemon_user.c b/arch/um/drivers/daemon_user.c
index 1bb085b2..c944265 100644
--- a/arch/um/drivers/daemon_user.c
+++ b/arch/um/drivers/daemon_user.c
@@ -158,10 +158,16 @@ static void daemon_remove(void *data)
 	struct daemon_data *pri = data;
 
 	os_close_file(pri->fd);
+	pri->fd = -1;
 	os_close_file(pri->control);
+	pri->control = -1;
+
 	kfree(pri->data_addr);
+	pri->data_addr = NULL;
 	kfree(pri->ctl_addr);
+	pri->ctl_addr = NULL;
 	kfree(pri->local_addr);
+	pri->local_addr = NULL;
 }
 
 int daemon_user_write(int fd, void *buf, int len, struct daemon_data *pri)
diff --git a/arch/um/drivers/fd.c b/arch/um/drivers/fd.c
index 3296e86..c41f75e 100644
--- a/arch/um/drivers/fd.c
+++ b/arch/um/drivers/fd.c
@@ -11,6 +11,7 @@
 #include "user.h"
 #include "user_util.h"
 #include "chan_user.h"
+#include "os.h"
 
 struct fd_chan {
 	int fd;
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index be61012..e3d5765 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -500,7 +500,7 @@ static void console_write(struct console *console, const char *string,
 
 static struct console mc_console = { .name	= "mc",
 				     .write	= console_write,
-				     .flags	= CON_PRINTBUFFER | CON_ENABLED,
+				     .flags	= CON_ENABLED,
 				     .index	= -1 };
 
 static int mc_add_console(void)
diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
index fb1f9fb..8ebb224 100644
--- a/arch/um/drivers/net_kern.c
+++ b/arch/um/drivers/net_kern.c
@@ -68,6 +68,11 @@ static int uml_net_rx(struct net_device *dev)
 	return pkt_len;
 }
 
+static void uml_dev_close(void* dev)
+{
+	dev_close( (struct net_device *) dev);
+}
+
 irqreturn_t uml_net_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 {
 	struct net_device *dev = dev_id;
@@ -80,15 +85,21 @@ irqreturn_t uml_net_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 	spin_lock(&lp->lock);
 	while((err = uml_net_rx(dev)) > 0) ;
 	if(err < 0) {
+		DECLARE_WORK(close_work, uml_dev_close, dev);
 		printk(KERN_ERR 
 		       "Device '%s' read returned %d, shutting it down\n", 
 		       dev->name, err);
-		dev_close(dev);
+		/* dev_close can't be called in interrupt context, and takes
+		 * again lp->lock.
+		 * And dev_close() can be safely called multiple times on the
+		 * same device, since it tests for (dev->flags & IFF_UP). So
+		 * there's no harm in delaying the device shutdown. */
+		schedule_work(&close_work);
 		goto out;
 	}
 	reactivate_fd(lp->fd, UM_ETH_IRQ);
 
- out:
+out:
 	spin_unlock(&lp->lock);
 	return(IRQ_HANDLED);
 }
@@ -317,6 +328,11 @@ static int eth_configure(int n, void *init, char *mac,
 		return 1;
 	}
 
+	lp = dev->priv;
+	/* This points to the transport private data. It's still clear, but we
+	 * must memset it to 0 *now*. Let's help the drivers. */
+	memset(lp, 0, size);
+
 	/* sysfs register */
 	if (!driver_registered) {
 		platform_driver_register(&uml_net_driver);
@@ -358,7 +374,6 @@ static int eth_configure(int n, void *init, char *mac,
 		free_netdev(dev);
 		return 1;
 	}
-	lp = dev->priv;
 
 	/* lp.user is the first four bytes of the transport data, which
 	 * has already been initialized.  This structure assignment will
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 73f9652..101efd2 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -117,6 +117,7 @@ static int ubd_open(struct inode * inode, struct file * filp);
 static int ubd_release(struct inode * inode, struct file * file);
 static int ubd_ioctl(struct inode * inode, struct file * file,
 		     unsigned int cmd, unsigned long arg);
+static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo);
 
 #define MAX_DEV (8)
 
@@ -125,6 +126,7 @@ static struct block_device_operations ubd_blops = {
         .open		= ubd_open,
         .release	= ubd_release,
         .ioctl		= ubd_ioctl,
+	.getgeo		= ubd_getgeo,
 };
 
 /* Protected by the queue_lock */
@@ -1058,10 +1060,19 @@ static void do_ubd_request(request_queue_t *q)
 	}
 }
 
+static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
+{
+	struct ubd *dev = bdev->bd_disk->private_data;
+
+	geo->heads = 128;
+	geo->sectors = 32;
+	geo->cylinders = dev->size / (128 * 32 * 512);
+	return 0;
+}
+
 static int ubd_ioctl(struct inode * inode, struct file * file,
 		     unsigned int cmd, unsigned long arg)
 {
-	struct hd_geometry __user *loc = (struct hd_geometry __user *) arg;
 	struct ubd *dev = inode->i_bdev->bd_disk->private_data;
 	struct hd_driveid ubd_id = {
 		.cyls		= 0,
@@ -1070,16 +1081,7 @@ static int ubd_ioctl(struct inode * inode, struct file * file,
 	};
 
 	switch (cmd) {
-	        struct hd_geometry g;
 		struct cdrom_volctrl volume;
-	case HDIO_GETGEO:
-		if(!loc) return(-EINVAL);
-		g.heads = 128;
-		g.sectors = 32;
-		g.cylinders = dev->size / (128 * 32 * 512);
-		g.start = get_start_sect(inode->i_bdev);
-		return(copy_to_user(loc, &g, sizeof(g)) ? -EFAULT : 0);
-
 	case HDIO_GET_IDENTITY:
 		ubd_id.cyls = dev->size / (128 * 32 * 512);
 		if(copy_to_user((char __user *) arg, (char *) &ubd_id,
@@ -1101,31 +1103,33 @@ static int ubd_ioctl(struct inode * inode, struct file * file,
 	return(-EINVAL);
 }
 
-static int same_backing_files(char *from_cmdline, char *from_cow, char *cow)
+static int path_requires_switch(char *from_cmdline, char *from_cow, char *cow)
 {
 	struct uml_stat buf1, buf2;
 	int err;
 
-	if(from_cmdline == NULL) return(1);
-	if(!strcmp(from_cmdline, from_cow)) return(1);
+	if(from_cmdline == NULL)
+		return 0;
+	if(!strcmp(from_cmdline, from_cow))
+		return 0;
 
 	err = os_stat_file(from_cmdline, &buf1);
 	if(err < 0){
 		printk("Couldn't stat '%s', err = %d\n", from_cmdline, -err);
-		return(1);
+		return 0;
 	}
 	err = os_stat_file(from_cow, &buf2);
 	if(err < 0){
 		printk("Couldn't stat '%s', err = %d\n", from_cow, -err);
-		return(1);
+		return 1;
 	}
 	if((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino))
-		return(1);
+		return 0;
 
 	printk("Backing file mismatch - \"%s\" requested,\n"
 	       "\"%s\" specified in COW header of \"%s\"\n",
 	       from_cmdline, from_cow, cow);
-	return(0);
+	return 1;
 }
 
 static int backing_file_mismatch(char *file, __u64 size, time_t mtime)
@@ -1187,18 +1191,19 @@ int open_ubd_file(char *file, struct openflags *openflags,
 	unsigned long long size;
 	__u32 version, align;
 	char *backing_file;
-	int fd, err, sectorsize, same, mode = 0644;
+	int fd, err, sectorsize, asked_switch, mode = 0644;
 
 	fd = os_open_file(file, *openflags, mode);
-	if(fd < 0){
-		if((fd == -ENOENT) && (create_cow_out != NULL))
+	if (fd < 0) {
+		if ((fd == -ENOENT) && (create_cow_out != NULL))
 			*create_cow_out = 1;
-                if(!openflags->w ||
-                   ((fd != -EROFS) && (fd != -EACCES))) return(fd);
+                if (!openflags->w ||
+                   ((fd != -EROFS) && (fd != -EACCES)))
+			return fd;
 		openflags->w = 0;
 		fd = os_open_file(file, *openflags, mode);
-		if(fd < 0)
-			return(fd);
+		if (fd < 0)
+			return fd;
         }
 
 	err = os_lock_file(fd, openflags->w);
@@ -1207,7 +1212,9 @@ int open_ubd_file(char *file, struct openflags *openflags,
 		goto out_close;
 	}
 
-	if(backing_file_out == NULL) return(fd);
+	/* Succesful return case! */
+	if(backing_file_out == NULL)
+		return(fd);
 
 	err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime,
 			      &size, &sectorsize, &align, bitmap_offset_out);
@@ -1216,34 +1223,34 @@ int open_ubd_file(char *file, struct openflags *openflags,
 		       "errno = %d\n", file, -err);
 		goto out_close;
 	}
-	if(err) return(fd);
-
-	if(backing_file_out == NULL) return(fd);
+	if(err)
+		return(fd);
 
-	same = same_backing_files(*backing_file_out, backing_file, file);
+	asked_switch = path_requires_switch(*backing_file_out, backing_file, file);
 
-	if(!same && !backing_file_mismatch(*backing_file_out, size, mtime)){
+	/* Allow switching only if no mismatch. */
+	if (asked_switch && !backing_file_mismatch(*backing_file_out, size, mtime)) {
 		printk("Switching backing file to '%s'\n", *backing_file_out);
 		err = write_cow_header(file, fd, *backing_file_out,
 				       sectorsize, align, &size);
-		if(err){
+		if (err) {
 			printk("Switch failed, errno = %d\n", -err);
-			return(err);
+			goto out_close;
 		}
-	}
-	else {
+	} else {
 		*backing_file_out = backing_file;
 		err = backing_file_mismatch(*backing_file_out, size, mtime);
-		if(err) goto out_close;
+		if (err)
+			goto out_close;
 	}
 
 	cow_sizes(version, size, sectorsize, align, *bitmap_offset_out,
 		  bitmap_len_out, data_offset_out);
 
-        return(fd);
+        return fd;
  out_close:
 	os_close_file(fd);
-	return(err);
+	return err;
 }
 
 int create_cow_file(char *cow_file, char *backing_file, struct openflags flags,
diff --git a/arch/um/include/kern_util.h b/arch/um/include/kern_util.h
index e5fec55..c649108 100644
--- a/arch/um/include/kern_util.h
+++ b/arch/um/include/kern_util.h
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -10,6 +10,19 @@
 #include "sysdep/ptrace.h"
 #include "sysdep/faultinfo.h"
 
+typedef void (*kern_hndl)(int, union uml_pt_regs *);
+
+struct kern_handlers {
+	kern_hndl relay_signal;
+	kern_hndl winch;
+	kern_hndl bus_handler;
+	kern_hndl page_fault;
+	kern_hndl sigio_handler;
+	kern_hndl timer_handler;
+};
+
+extern struct kern_handlers handlinfo_kern;
+
 extern int ncpus;
 extern char *linux_prog;
 extern char *gdb_init;
@@ -51,8 +64,6 @@ extern void timer_handler(int sig, union uml_pt_regs *regs);
 extern int set_signals(int enable);
 extern void force_sigbus(void);
 extern int pid_to_processor_id(int pid);
-extern void block_signals(void);
-extern void unblock_signals(void);
 extern void deliver_signals(void *t);
 extern int next_syscall_index(int max);
 extern int next_trap_index(int max);
@@ -109,9 +120,13 @@ extern void machine_halt(void);
 extern int is_syscall(unsigned long addr);
 extern void arch_switch(void);
 extern void free_irq(unsigned int, void *);
-extern int um_in_interrupt(void);
 extern int cpu(void);
 
+/* Are we disallowed to sleep? Used to choose between GFP_KERNEL and GFP_ATOMIC. */
+extern int __cant_sleep(void);
+extern void segv_handler(int sig, union uml_pt_regs *regs);
+extern void sigio_handler(int sig, union uml_pt_regs *regs);
+
 #endif
 
 /*
diff --git a/arch/um/include/longjmp.h b/arch/um/include/longjmp.h
new file mode 100644
index 0000000..018b381
--- /dev/null
+++ b/arch/um/include/longjmp.h
@@ -0,0 +1,19 @@
+#ifndef __UML_LONGJMP_H
+#define __UML_LONGJMP_H
+
+#include <setjmp.h>
+#include "os.h"
+
+#define UML_SIGLONGJMP(buf, val) do { \
+	longjmp(*buf, val);	\
+} while(0)
+
+#define UML_SIGSETJMP(buf, enable) ({ \
+	int n; \
+	enable = get_signals(); \
+	n = setjmp(*buf); \
+	if(n != 0) \
+		set_signals(enable); \
+	n; })
+
+#endif
diff --git a/arch/um/include/mode_kern.h b/arch/um/include/mode_kern.h
index 2d88afd..e7539a8 100644
--- a/arch/um/include/mode_kern.h
+++ b/arch/um/include/mode_kern.h
@@ -9,22 +9,11 @@
 #include "linux/config.h"
 
 #ifdef CONFIG_MODE_TT
-#include "mode_kern-tt.h"
+#include "mode_kern_tt.h"
 #endif
 
 #ifdef CONFIG_MODE_SKAS
-#include "mode_kern-skas.h"
+#include "mode_kern_skas.h"
 #endif
 
 #endif
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index c279ee6..eb1710b 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -9,6 +9,9 @@
 #include "uml-config.h"
 #include "asm/types.h"
 #include "../os/include/file.h"
+#include "sysdep/ptrace.h"
+#include "kern_util.h"
+#include "skas/mm_id.h"
 
 #define OS_TYPE_FILE 1 
 #define OS_TYPE_DIR 2 
@@ -188,11 +191,12 @@ extern int os_protect_memory(void *addr, unsigned long len,
 			     int r, int w, int x);
 extern int os_unmap_memory(void *addr, int len);
 extern void os_flush_stdout(void);
-extern unsigned long long os_usecs(void);
 
 /* tt.c
  * for tt mode only (will be deleted in future...)
  */
+extern void stop(void);
+extern int wait_for_stop(int pid, int sig, int cont_type, void *relay);
 extern int protect_memory(unsigned long addr, unsigned long len,
 			  int r, int w, int x, int must_succeed);
 extern void forward_pending_sigio(int target);
@@ -219,4 +223,72 @@ extern int umid_file_name(char *name, char *buf, int len);
 extern int set_umid(char *name);
 extern char *get_umid(void);
 
+/* signal.c */
+extern void set_sigstack(void *sig_stack, int size);
+extern void remove_sigstack(void);
+extern void set_handler(int sig, void (*handler)(int), int flags, ...);
+extern int change_sig(int signal, int on);
+extern void block_signals(void);
+extern void unblock_signals(void);
+extern int get_signals(void);
+extern int set_signals(int enable);
+extern void os_usr1_signal(int on);
+
+/* trap.c */
+extern void os_fill_handlinfo(struct kern_handlers h);
+extern void do_longjmp(void *p, int val);
+
+/* util.c */
+extern void stack_protections(unsigned long address);
+extern void task_protections(unsigned long address);
+extern int raw(int fd);
+extern void setup_machinename(char *machine_out);
+extern void setup_hostinfo(void);
+extern int setjmp_wrapper(void (*proc)(void *, void *), ...);
+
+/* time.c */
+#define BILLION (1000 * 1000 * 1000)
+
+extern void switch_timers(int to_real);
+extern void idle_sleep(int secs);
+extern void enable_timer(void);
+extern void disable_timer(void);
+extern void user_time_init(void);
+extern void uml_idle_timer(void);
+extern unsigned long long os_nsecs(void);
+
+/* skas/mem.c */
+extern long run_syscall_stub(struct mm_id * mm_idp,
+			     int syscall, unsigned long *args, long expected,
+			     void **addr, int done);
+extern long syscall_stub_data(struct mm_id * mm_idp,
+			      unsigned long *data, int data_count,
+			      void **addr, void **stub_addr);
+extern int map(struct mm_id * mm_idp, unsigned long virt,
+	       unsigned long len, int r, int w, int x, int phys_fd,
+	       unsigned long long offset, int done, void **data);
+extern int unmap(struct mm_id * mm_idp, void *addr, unsigned long len,
+		 int done, void **data);
+extern int protect(struct mm_id * mm_idp, unsigned long addr,
+		   unsigned long len, int r, int w, int x, int done,
+		   void **data);
+
+/* skas/process.c */
+extern int is_skas_winch(int pid, int fd, void *data);
+extern int start_userspace(unsigned long stub_stack);
+extern int copy_context_skas0(unsigned long stack, int pid);
+extern void userspace(union uml_pt_regs *regs);
+extern void map_stub_pages(int fd, unsigned long code,
+			   unsigned long data, unsigned long stack);
+extern void new_thread(void *stack, void **switch_buf_ptr,
+			 void **fork_buf_ptr, void (*handler)(int));
+extern void thread_wait(void *sw, void *fb);
+extern void switch_threads(void *me, void *next);
+extern int start_idle_thread(void *stack, void *switch_buf_ptr,
+			     void **fork_buf_ptr);
+extern void initial_thread_cb_skas(void (*proc)(void *),
+				 void *arg);
+extern void halt_skas(void);
+extern void reboot_skas(void);
+
 #endif
diff --git a/arch/um/include/signal_user.h b/arch/um/include/signal_user.h
deleted file mode 100644
index b075e54..0000000
--- a/arch/um/include/signal_user.h
+++ /dev/null
@@ -1,28 +0,0 @@
-/* 
- * Copyright (C) 2001 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#ifndef __SIGNAL_USER_H__
-#define __SIGNAL_USER_H__
-
-extern int signal_stack_size;
-
-extern int change_sig(int signal, int on);
-extern void set_sigstack(void *stack, int size);
-extern void set_handler(int sig, void (*handler)(int), int flags, ...);
-extern int set_signals(int enable);
-extern int get_signals(void);
-
-#endif
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/kernel/skas/include/mm_id.h b/arch/um/include/skas/mm_id.h
index 48dd098..48dd098 100644
--- a/arch/um/kernel/skas/include/mm_id.h
+++ b/arch/um/include/skas/mm_id.h
diff --git a/arch/um/include/skas/mmu-skas.h b/arch/um/include/skas/mmu-skas.h
new file mode 100644
index 0000000..d8869a6
--- /dev/null
+++ b/arch/um/include/skas/mmu-skas.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __SKAS_MMU_H
+#define __SKAS_MMU_H
+
+#include "linux/config.h"
+#include "mm_id.h"
+#include "asm/ldt.h"
+
+struct mmu_context_skas {
+	struct mm_id id;
+	unsigned long last_page_table;
+#ifdef CONFIG_3_LEVEL_PGTABLES
+	unsigned long last_pmd;
+#endif
+	uml_ldt_t ldt;
+};
+
+extern void switch_mm_skas(struct mm_id * mm_idp);
+
+#endif
diff --git a/arch/um/include/skas/mode-skas.h b/arch/um/include/skas/mode-skas.h
new file mode 100644
index 0000000..260065c
--- /dev/null
+++ b/arch/um/include/skas/mode-skas.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __MODE_SKAS_H__
+#define __MODE_SKAS_H__
+
+#include <sysdep/ptrace.h>
+
+extern unsigned long exec_regs[];
+extern unsigned long exec_fp_regs[];
+extern unsigned long exec_fpx_regs[];
+extern int have_fpx_regs;
+
+extern void sig_handler_common_skas(int sig, void *sc_ptr);
+extern void kill_off_processes_skas(void);
+
+#endif
diff --git a/arch/um/kernel/skas/include/mode_kern-skas.h b/arch/um/include/skas/mode_kern_skas.h
index c97a80d..63c5873 100644
--- a/arch/um/kernel/skas/include/mode_kern-skas.h
+++ b/arch/um/include/skas/mode_kern_skas.h
@@ -18,7 +18,6 @@ extern int copy_thread_skas(int nr, unsigned long clone_flags,
 			    unsigned long sp, unsigned long stack_top,
 			    struct task_struct *p, struct pt_regs *regs);
 extern void release_thread_skas(struct task_struct *task);
-extern void initial_thread_cb_skas(void (*proc)(void *), void *arg);
 extern void init_idle_skas(void);
 extern void flush_tlb_kernel_range_skas(unsigned long start,
 					unsigned long end);
@@ -39,14 +38,3 @@ extern int thread_pid_skas(struct task_struct *task);
 #define kmem_end_skas (host_task_size - 1024 * 1024)
 
 #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/skas/include/proc_mm.h b/arch/um/include/skas/proc_mm.h
index cce61a6..9028092 100644
--- a/arch/um/kernel/skas/include/proc_mm.h
+++ b/arch/um/include/skas/proc_mm.h
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -22,13 +22,13 @@ struct mm_mmap {
 
 struct mm_munmap {
 	unsigned long addr;
-	unsigned long len;	
+	unsigned long len;
 };
 
 struct mm_mprotect {
 	unsigned long addr;
 	unsigned long len;
-        unsigned int prot;
+	unsigned int prot;
 };
 
 struct proc_mm_op {
@@ -42,14 +42,3 @@ struct proc_mm_op {
 };
 
 #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/skas/skas.h b/arch/um/include/skas/skas.h
new file mode 100644
index 0000000..8635728
--- /dev/null
+++ b/arch/um/include/skas/skas.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __SKAS_H
+#define __SKAS_H
+
+#include "mm_id.h"
+#include "sysdep/ptrace.h"
+
+extern int userspace_pid[];
+extern int proc_mm, ptrace_faultinfo, ptrace_ldt;
+extern int skas_needs_stub;
+
+extern int user_thread(unsigned long stack, int flags);
+extern void new_thread_proc(void *stack, void (*handler)(int sig));
+extern void new_thread_handler(int sig);
+extern void handle_syscall(union uml_pt_regs *regs);
+extern void user_signal(int sig, union uml_pt_regs *regs, int pid);
+extern int new_mm(unsigned long stack);
+extern void get_skas_faultinfo(int pid, struct faultinfo * fi);
+extern long execute_syscall_skas(void *r);
+extern unsigned long current_stub_stack(void);
+
+#endif
diff --git a/arch/um/kernel/skas/include/stub-data.h b/arch/um/include/skas/stub-data.h
index f6ed92c..f6ed92c 100644
--- a/arch/um/kernel/skas/include/stub-data.h
+++ b/arch/um/include/skas/stub-data.h
diff --git a/arch/um/kernel/skas/include/uaccess-skas.h b/arch/um/include/skas/uaccess-skas.h
index 64516c5..224a75f 100644
--- a/arch/um/kernel/skas/include/uaccess-skas.h
+++ b/arch/um/include/skas/uaccess-skas.h
@@ -19,14 +19,3 @@ extern int clear_user_skas(void __user *mem, int len);
 extern int strnlen_user_skas(const void __user *str, int len);
 
 #endif
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/include/sysdep-i386/checksum.h b/arch/um/include/sysdep-i386/checksum.h
index 764ba4d..7d3d202 100644
--- a/arch/um/include/sysdep-i386/checksum.h
+++ b/arch/um/include/sysdep-i386/checksum.h
@@ -36,7 +36,7 @@ unsigned int csum_partial_copy_nocheck(const unsigned char *src, unsigned char *
 				       int len, int sum)
 {
 	memcpy(dst, src, len);
-	return(csum_partial(dst, len, sum));
+	return csum_partial(dst, len, sum);
 }
 
 /*
@@ -104,7 +104,7 @@ static inline unsigned short ip_fast_csum(unsigned char * iph,
 	: "=r" (sum), "=r" (iph), "=r" (ihl)
 	: "1" (iph), "2" (ihl)
 	: "memory");
-	return(sum);
+	return sum;
 }
 
 /*
diff --git a/arch/um/sys-i386/kernel-offsets.c b/arch/um/include/sysdep-i386/kernel-offsets.h
index 35db850..82f96c5 100644
--- a/arch/um/sys-i386/kernel-offsets.c
+++ b/arch/um/include/sysdep-i386/kernel-offsets.h
@@ -1,12 +1,9 @@
-#include <linux/config.h>
 #include <linux/stddef.h>
 #include <linux/sched.h>
-#include <linux/time.h>
 #include <linux/elf.h>
-#include <asm/page.h>
 
 #define DEFINE(sym, val) \
-        asm volatile("\n->" #sym " %0 " #val : : "i" (val))
+	asm volatile("\n->" #sym " %0 " #val : : "i" (val))
 
 #define STR(x) #x
 #define DEFINE_STR(sym, val) asm volatile("\n->" #sym " " STR(val) " " #val: : )
diff --git a/arch/um/sys-x86_64/kernel-offsets.c b/arch/um/include/sysdep-x86_64/kernel-offsets.h
index bfcb104..5ce93abd 100644
--- a/arch/um/sys-x86_64/kernel-offsets.c
+++ b/arch/um/include/sysdep-x86_64/kernel-offsets.h
@@ -6,7 +6,7 @@
 #include <asm/page.h>
 
 #define DEFINE(sym, val) \
-        asm volatile("\n->" #sym " %0 " #val : : "i" (val))
+	asm volatile("\n->" #sym " %0 " #val : : "i" (val))
 
 #define DEFINE_STR1(x) #x
 #define DEFINE_STR(sym, val) asm volatile("\n->" #sym " " DEFINE_STR1(val) " " #val: : )
diff --git a/arch/um/include/time_user.h b/arch/um/include/time_user.h
deleted file mode 100644
index 17d7ef2..0000000
--- a/arch/um/include/time_user.h
+++ /dev/null
@@ -1,19 +0,0 @@
-/* 
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#ifndef __TIME_USER_H__
-#define __TIME_USER_H__
-
-extern void timer(void);
-extern void switch_timers(int to_real);
-extern void idle_sleep(int secs);
-extern void enable_timer(void);
-extern void prepare_timer(void * ptr);
-extern void disable_timer(void);
-extern unsigned long time_lock(void);
-extern void time_unlock(unsigned long);
-extern void user_time_init(void);
-
-#endif
diff --git a/arch/um/kernel/tt/include/debug.h b/arch/um/include/tt/debug.h
index 7384354..9778fa8 100644
--- a/arch/um/kernel/tt/include/debug.h
+++ b/arch/um/include/tt/debug.h
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2000, 2001, 2002  Jeff Dike (jdike@karaya.com) and
  * Lars Brinkhoff.
  * Licensed under the GPL
diff --git a/arch/um/include/tt/mmu-tt.h b/arch/um/include/tt/mmu-tt.h
new file mode 100644
index 0000000..572a78b2
--- /dev/null
+++ b/arch/um/include/tt/mmu-tt.h
@@ -0,0 +1,12 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __TT_MMU_H
+#define __TT_MMU_H
+
+struct mmu_context_tt {
+};
+
+#endif
diff --git a/arch/um/include/tt/mode-tt.h b/arch/um/include/tt/mode-tt.h
new file mode 100644
index 0000000..2823cd5
--- /dev/null
+++ b/arch/um/include/tt/mode-tt.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __MODE_TT_H__
+#define __MODE_TT_H__
+
+#include "sysdep/ptrace.h"
+
+enum { OP_NONE, OP_EXEC, OP_FORK, OP_TRACE_ON, OP_REBOOT, OP_HALT, OP_CB };
+
+extern int tracing_pid;
+
+extern int tracer(int (*init_proc)(void *), void *sp);
+extern void sig_handler_common_tt(int sig, void *sc);
+extern void syscall_handler_tt(int sig, union uml_pt_regs *regs);
+extern void reboot_tt(void);
+extern void halt_tt(void);
+extern int is_tracer_winch(int pid, int fd, void *data);
+extern void kill_off_processes_tt(void);
+
+#endif
diff --git a/arch/um/include/tt/mode_kern_tt.h b/arch/um/include/tt/mode_kern_tt.h
new file mode 100644
index 0000000..efa0012
--- /dev/null
+++ b/arch/um/include/tt/mode_kern_tt.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __TT_MODE_KERN_H__
+#define __TT_MODE_KERN_H__
+
+#include "linux/sched.h"
+#include "asm/page.h"
+#include "asm/ptrace.h"
+#include "asm/uaccess.h"
+
+extern void switch_to_tt(void *prev, void *next);
+extern void flush_thread_tt(void);
+extern void start_thread_tt(struct pt_regs *regs, unsigned long eip,
+			   unsigned long esp);
+extern int copy_thread_tt(int nr, unsigned long clone_flags, unsigned long sp,
+			  unsigned long stack_top, struct task_struct *p,
+			  struct pt_regs *regs);
+extern void release_thread_tt(struct task_struct *task);
+extern void initial_thread_cb_tt(void (*proc)(void *), void *arg);
+extern void init_idle_tt(void);
+extern void flush_tlb_kernel_range_tt(unsigned long start, unsigned long end);
+extern void flush_tlb_kernel_vm_tt(void);
+extern void __flush_tlb_one_tt(unsigned long addr);
+extern void flush_tlb_range_tt(struct vm_area_struct *vma,
+			       unsigned long start, unsigned long end);
+extern void flush_tlb_mm_tt(struct mm_struct *mm);
+extern void force_flush_all_tt(void);
+extern long execute_syscall_tt(void *r);
+extern void before_mem_tt(unsigned long brk_start);
+extern unsigned long set_task_sizes_tt(int arg, unsigned long *host_size_out,
+				       unsigned long *task_size_out);
+extern int start_uml_tt(void);
+extern int external_pid_tt(struct task_struct *task);
+extern int thread_pid_tt(struct task_struct *task);
+
+#define kmem_end_tt (host_task_size - ABOVE_KMEM)
+
+#endif
diff --git a/arch/um/kernel/tt/include/tt.h b/arch/um/include/tt/tt.h
index c667b67..8085219 100644
--- a/arch/um/kernel/tt/include/tt.h
+++ b/arch/um/include/tt/tt.h
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -34,13 +34,3 @@ extern long execute_syscall_tt(void *r);
 
 #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/tt/include/uaccess-tt.h b/arch/um/include/tt/uaccess-tt.h
index b9bfe9c..b19645f 100644
--- a/arch/um/kernel/tt/include/uaccess-tt.h
+++ b/arch/um/include/tt/uaccess-tt.h
@@ -46,14 +46,3 @@ extern int clear_user_tt(void __user *mem, int len);
 extern int strnlen_user_tt(const void __user *str, int len);
 
 #endif
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/include/user.h b/arch/um/include/user.h
index 0f865ef..91b0ac4 100644
--- a/arch/um/include/user.h
+++ b/arch/um/include/user.h
@@ -18,6 +18,7 @@ extern int open_gdb_chan(void);
 extern unsigned long strlcpy(char *, const char *, unsigned long);
 extern unsigned long strlcat(char *, const char *, unsigned long);
 extern void *um_vmalloc(int size);
+extern void *um_vmalloc_atomic(int size);
 extern void vfree(void *ptr);
 
 #endif
diff --git a/arch/um/include/user_util.h b/arch/um/include/user_util.h
index b998400..a6f1f17 100644
--- a/arch/um/include/user_util.h
+++ b/arch/um/include/user_util.h
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -23,12 +23,7 @@ struct cpu_task {
 
 extern struct cpu_task cpu_tasks[];
 
-struct signal_info {
-	void (*handler)(int, union uml_pt_regs *);
-	int is_irq;
-};
-
-extern struct signal_info sig_info[];
+extern void (*sig_info[])(int, union uml_pt_regs *);
 
 extern unsigned long low_physmem;
 extern unsigned long high_physmem;
@@ -49,10 +44,6 @@ extern unsigned long brk_start;
 extern int pty_output_sigio;
 extern int pty_close_sigio;
 
-extern void stop(void);
-extern void stack_protections(unsigned long address);
-extern void task_protections(unsigned long address);
-extern int wait_for_stop(int pid, int sig, int cont_type, void *relay);
 extern void *add_signal_handler(int sig, void (*handler)(int));
 extern int linux_main(int argc, char **argv);
 extern void set_cmdline(char *cmd);
@@ -60,11 +51,8 @@ extern void input_cb(void (*proc)(void *), void *arg, int arg_len);
 extern int get_pty(void);
 extern void *um_kmalloc(int size);
 extern int switcheroo(int fd, int prot, void *from, void *to, int size);
-extern void setup_machinename(char *machine_out);
-extern void setup_hostinfo(void);
 extern void do_exec(int old_pid, int new_pid);
 extern void tracer_panic(char *msg, ...);
-extern void do_longjmp(void *p, int val);
 extern int detach(int pid, int sig);
 extern int attach(int pid);
 extern void kill_child_dead(int pid);
@@ -76,18 +64,6 @@ extern int cpu_feature(char *what, char *buf, int len);
 extern int arch_handle_signal(int sig, union uml_pt_regs *regs);
 extern int arch_fixup(unsigned long address, void *sc_ptr);
 extern void arch_init_thread(void);
-extern int setjmp_wrapper(void (*proc)(void *, void *), ...);
 extern int raw(int fd);
 
 #endif
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile
index 6f77005..693018b 100644
--- a/arch/um/kernel/Makefile
+++ b/arch/um/kernel/Makefile
@@ -9,9 +9,8 @@ clean-files :=
 obj-y = config.o exec_kern.o exitcode.o \
 	init_task.o irq.o irq_user.o ksyms.o mem.o physmem.o \
 	process_kern.o ptrace.o reboot.o resource.o sigio_user.o sigio_kern.o \
-	signal_kern.o signal_user.o smp.o syscall_kern.o sysrq.o time.o \
-	time_kern.o tlb.o trap_kern.o trap_user.o uaccess.o um_arch.o umid.o \
-	user_util.o
+	signal_kern.o smp.o syscall_kern.o sysrq.o \
+	time_kern.o tlb.o trap_kern.o uaccess.o um_arch.o umid.o
 
 obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o
 obj-$(CONFIG_GPROF)	+= gprof_syms.o
@@ -24,7 +23,7 @@ obj-$(CONFIG_MODE_SKAS) += skas/
 
 user-objs-$(CONFIG_TTY_LOG) += tty_log.o
 
-USER_OBJS := $(user-objs-y) config.o time.o tty_log.o user_util.o
+USER_OBJS := $(user-objs-y) config.o tty_log.o
 
 include arch/um/scripts/Makefile.rules
 
diff --git a/arch/um/kernel/asm-offsets.c b/arch/um/kernel/asm-offsets.c
index c13a64a..91ea538 100644
--- a/arch/um/kernel/asm-offsets.c
+++ b/arch/um/kernel/asm-offsets.c
@@ -1 +1 @@
-/* Dummy file to make kbuild happy - unused! */
+#include "sysdep/kernel-offsets.h"
diff --git a/arch/um/kernel/exec_kern.c b/arch/um/kernel/exec_kern.c
index efd222f..569fe8b 100644
--- a/arch/um/kernel/exec_kern.c
+++ b/arch/um/kernel/exec_kern.c
@@ -17,7 +17,6 @@
 #include "irq_user.h"
 #include "tlb.h"
 #include "os.h"
-#include "time_user.h"
 #include "choose-mode.h"
 #include "mode_kern.h"
 
diff --git a/arch/um/kernel/irq_user.c b/arch/um/kernel/irq_user.c
index 50a2aa3..0e32f5f 100644
--- a/arch/um/kernel/irq_user.c
+++ b/arch/um/kernel/irq_user.c
@@ -15,7 +15,6 @@
 #include "kern_util.h"
 #include "user.h"
 #include "process.h"
-#include "signal_user.h"
 #include "sigio.h"
 #include "irq_user.h"
 #include "os.h"
diff --git a/arch/um/kernel/process_kern.c b/arch/um/kernel/process_kern.c
index 651abf2..3113cab 100644
--- a/arch/um/kernel/process_kern.c
+++ b/arch/um/kernel/process_kern.c
@@ -36,11 +36,9 @@
 #include "kern_util.h"
 #include "kern.h"
 #include "signal_kern.h"
-#include "signal_user.h"
 #include "init.h"
 #include "irq_user.h"
 #include "mem_user.h"
-#include "time_user.h"
 #include "tlb.h"
 #include "frame_kern.h"
 #include "sigcontext.h"
@@ -108,7 +106,7 @@ void set_current(void *t)
 {
 	struct task_struct *task = t;
 
-	cpu_tasks[task->thread_info->cpu] = ((struct cpu_task) 
+	cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
 		{ external_pid(task), task });
 }
 
@@ -289,17 +287,27 @@ EXPORT_SYMBOL(disable_hlt);
 
 void *um_kmalloc(int size)
 {
-	return(kmalloc(size, GFP_KERNEL));
+	return kmalloc(size, GFP_KERNEL);
 }
 
 void *um_kmalloc_atomic(int size)
 {
-	return(kmalloc(size, GFP_ATOMIC));
+	return kmalloc(size, GFP_ATOMIC);
 }
 
 void *um_vmalloc(int size)
 {
-	return(vmalloc(size));
+	return vmalloc(size);
+}
+
+void *um_vmalloc_atomic(int size)
+{
+	return __vmalloc(size, GFP_ATOMIC | __GFP_HIGHMEM, PAGE_KERNEL);
+}
+
+int __cant_sleep(void) {
+	return in_atomic() || irqs_disabled() || in_interrupt();
+	/* Is in_interrupt() really needed? */
 }
 
 unsigned long get_fault_addr(void)
@@ -371,11 +379,6 @@ int smp_sigio_handler(void)
 	return(0);
 }
 
-int um_in_interrupt(void)
-{
-	return(in_interrupt());
-}
-
 int cpu(void)
 {
 	return(current_thread->cpu);
diff --git a/arch/um/kernel/reboot.c b/arch/um/kernel/reboot.c
index a637e88..6f1a3a2 100644
--- a/arch/um/kernel/reboot.c
+++ b/arch/um/kernel/reboot.c
@@ -12,6 +12,8 @@
 #include "mode.h"
 #include "choose-mode.h"
 
+void (*pm_power_off)(void);
+
 #ifdef CONFIG_SMP
 static void kill_idlers(int me)
 {
diff --git a/arch/um/kernel/sigio_user.c b/arch/um/kernel/sigio_user.c
index 62e5cfd..f7b18e1 100644
--- a/arch/um/kernel/sigio_user.c
+++ b/arch/um/kernel/sigio_user.c
@@ -337,70 +337,103 @@ int ignore_sigio_fd(int fd)
 	return(err);
 }
 
-static int setup_initial_poll(int fd)
+static struct pollfd* setup_initial_poll(int fd)
 {
 	struct pollfd *p;
 
-	p = um_kmalloc_atomic(sizeof(struct pollfd));
-	if(p == NULL){
+	p = um_kmalloc(sizeof(struct pollfd));
+	if (p == NULL) {
 		printk("setup_initial_poll : failed to allocate poll\n");
-		return(-1);
+		return NULL;
 	}
 	*p = ((struct pollfd) { .fd  	= fd,
 				.events 	= POLLIN,
 				.revents 	= 0 });
-	current_poll = ((struct pollfds) { .poll 	= p,
-					   .used 	= 1,
-					   .size 	= 1 });
-	return(0);
+	return p;
 }
 
 void write_sigio_workaround(void)
 {
 	unsigned long stack;
+	struct pollfd *p;
 	int err;
+	int l_write_sigio_fds[2];
+	int l_sigio_private[2];
+	int l_write_sigio_pid;
 
+	/* We call this *tons* of times - and most ones we must just fail. */
 	sigio_lock();
-	if(write_sigio_pid != -1)
-		goto out;
+	l_write_sigio_pid = write_sigio_pid;
+	sigio_unlock();
 
-	err = os_pipe(write_sigio_fds, 1, 1);
+	if (l_write_sigio_pid != -1)
+		return;
+
+	err = os_pipe(l_write_sigio_fds, 1, 1);
 	if(err < 0){
 		printk("write_sigio_workaround - os_pipe 1 failed, "
 		       "err = %d\n", -err);
-		goto out;
+		return;
 	}
-	err = os_pipe(sigio_private, 1, 1);
+	err = os_pipe(l_sigio_private, 1, 1);
 	if(err < 0){
-		printk("write_sigio_workaround - os_pipe 2 failed, "
+		printk("write_sigio_workaround - os_pipe 1 failed, "
 		       "err = %d\n", -err);
 		goto out_close1;
 	}
-	if(setup_initial_poll(sigio_private[1]))
+
+	p = setup_initial_poll(l_sigio_private[1]);
+	if(!p)
 		goto out_close2;
 
-	write_sigio_pid = run_helper_thread(write_sigio_thread, NULL, 
+	sigio_lock();
+
+	/* Did we race? Don't try to optimize this, please, it's not so likely
+	 * to happen, and no more than once at the boot. */
+	if(write_sigio_pid != -1)
+		goto out_unlock;
+
+	write_sigio_pid = run_helper_thread(write_sigio_thread, NULL,
 					    CLONE_FILES | CLONE_VM, &stack, 0);
 
-	if(write_sigio_pid < 0) goto out_close2;
+	if (write_sigio_pid < 0)
+		goto out_clear;
 
-	if(write_sigio_irq(write_sigio_fds[0])) 
+	if (write_sigio_irq(l_write_sigio_fds[0]))
 		goto out_kill;
 
- out:
+	/* Success, finally. */
+	memcpy(write_sigio_fds, l_write_sigio_fds, sizeof(l_write_sigio_fds));
+	memcpy(sigio_private, l_sigio_private, sizeof(l_sigio_private));
+
+	current_poll = ((struct pollfds) { .poll 	= p,
+					   .used 	= 1,
+					   .size 	= 1 });
+
 	sigio_unlock();
 	return;
 
  out_kill:
-	os_kill_process(write_sigio_pid, 1);
+	l_write_sigio_pid = write_sigio_pid;
 	write_sigio_pid = -1;
+	sigio_unlock();
+	/* Going to call waitpid, avoid holding the lock. */
+	os_kill_process(l_write_sigio_pid, 1);
+	goto out_free;
+
+ out_clear:
+	write_sigio_pid = -1;
+ out_unlock:
+	sigio_unlock();
+ out_free:
+	kfree(p);
  out_close2:
-	os_close_file(sigio_private[0]);
-	os_close_file(sigio_private[1]);
+	os_close_file(l_sigio_private[0]);
+	os_close_file(l_sigio_private[1]);
  out_close1:
-	os_close_file(write_sigio_fds[0]);
-	os_close_file(write_sigio_fds[1]);
-	sigio_unlock();
+	os_close_file(l_write_sigio_fds[0]);
+	os_close_file(l_write_sigio_fds[1]);
+	return;
 }
 
 int read_sigio_fd(int fd)
diff --git a/arch/um/kernel/signal_kern.c b/arch/um/kernel/signal_kern.c
index 03618bd..da17b75 100644
--- a/arch/um/kernel/signal_kern.c
+++ b/arch/um/kernel/signal_kern.c
@@ -22,7 +22,6 @@
 #include "asm/ucontext.h"
 #include "kern_util.h"
 #include "signal_kern.h"
-#include "signal_user.h"
 #include "kern.h"
 #include "frame_kern.h"
 #include "sigcontext.h"
@@ -100,31 +99,46 @@ static int handle_signal(struct pt_regs *regs, unsigned long signr,
 	return err;
 }
 
-static int kern_do_signal(struct pt_regs *regs, sigset_t *oldset)
+static int kern_do_signal(struct pt_regs *regs)
 {
 	struct k_sigaction ka_copy;
 	siginfo_t info;
+	sigset_t *oldset;
 	int sig, handled_sig = 0;
 
+	if (test_thread_flag(TIF_RESTORE_SIGMASK))
+		oldset = &current->saved_sigmask;
+	else
+		oldset = &current->blocked;
+
 	while((sig = get_signal_to_deliver(&info, &ka_copy, regs, NULL)) > 0){
 		handled_sig = 1;
 		/* Whee!  Actually deliver the signal.  */
-		if(!handle_signal(regs, sig, &ka_copy, &info, oldset))
+		if(!handle_signal(regs, sig, &ka_copy, &info, oldset)){
+			/* a signal was successfully delivered; the saved
+			 * sigmask will have been stored in the signal frame,
+			 * and will be restored by sigreturn, so we can simply
+			 * clear the TIF_RESTORE_SIGMASK flag */
+			if (test_thread_flag(TIF_RESTORE_SIGMASK))
+				clear_thread_flag(TIF_RESTORE_SIGMASK);
 			break;
+		}
 	}
 
 	/* Did we come from a system call? */
 	if(!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)){
 		/* Restart the system call - no handlers present */
-		if(PT_REGS_SYSCALL_RET(regs) == -ERESTARTNOHAND ||
-		   PT_REGS_SYSCALL_RET(regs) == -ERESTARTSYS ||
-		   PT_REGS_SYSCALL_RET(regs) == -ERESTARTNOINTR){
+		switch(PT_REGS_SYSCALL_RET(regs)){
+		case -ERESTARTNOHAND:
+		case -ERESTARTSYS:
+		case -ERESTARTNOINTR:
 			PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
 			PT_REGS_RESTART_SYSCALL(regs);
-		}
-		else if(PT_REGS_SYSCALL_RET(regs) == -ERESTART_RESTARTBLOCK){
+			break;
+		case -ERESTART_RESTARTBLOCK:
 			PT_REGS_SYSCALL_RET(regs) = __NR_restart_syscall;
 			PT_REGS_RESTART_SYSCALL(regs);
+			break;
  		}
 	}
 
@@ -138,12 +152,19 @@ static int kern_do_signal(struct pt_regs *regs, sigset_t *oldset)
 	if(current->ptrace & PT_DTRACE)
 		current->thread.singlestep_syscall =
 			is_syscall(PT_REGS_IP(&current->thread.regs));
+
+	/* if there's no signal to deliver, we just put the saved sigmask
+	 * back */
+	if (!handled_sig && test_thread_flag(TIF_RESTORE_SIGMASK)) {
+		clear_thread_flag(TIF_RESTORE_SIGMASK);
+		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
+	}
 	return(handled_sig);
 }
 
 int do_signal(void)
 {
-	return(kern_do_signal(&current->thread.regs, &current->blocked));
+	return(kern_do_signal(&current->thread.regs));
 }
 
 /*
@@ -151,63 +172,20 @@ int do_signal(void)
  */
 long sys_sigsuspend(int history0, int history1, old_sigset_t mask)
 {
-	sigset_t saveset;
-
 	mask &= _BLOCKABLE;
 	spin_lock_irq(&current->sighand->siglock);
-	saveset = current->blocked;
+	current->saved_sigmask = current->blocked;
 	siginitset(&current->blocked, mask);
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
-	PT_REGS_SYSCALL_RET(&current->thread.regs) = -EINTR;
-	while (1) {
-		current->state = TASK_INTERRUPTIBLE;
-		schedule();
-		if(kern_do_signal(&current->thread.regs, &saveset))
-			return(-EINTR);
-	}
-}
-
-long sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize)
-{
-	sigset_t saveset, newset;
-
-	/* XXX: Don't preclude handling different sized sigset_t's.  */
-	if (sigsetsize != sizeof(sigset_t))
-		return -EINVAL;
-
-	if (copy_from_user(&newset, unewset, sizeof(newset)))
-		return -EFAULT;
-	sigdelsetmask(&newset, ~_BLOCKABLE);
-
-	spin_lock_irq(&current->sighand->siglock);
-	saveset = current->blocked;
-	current->blocked = newset;
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
-
-	PT_REGS_SYSCALL_RET(&current->thread.regs) = -EINTR;
-	while (1) {
-		current->state = TASK_INTERRUPTIBLE;
-		schedule();
-		if (kern_do_signal(&current->thread.regs, &saveset))
-			return(-EINTR);
-	}
+	current->state = TASK_INTERRUPTIBLE;
+	schedule();
+	set_thread_flag(TIF_RESTORE_SIGMASK);
+	return -ERESTARTNOHAND;
 }
 
 long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
 {
 	return(do_sigaltstack(uss, uoss, PT_REGS_SP(&current->thread.regs)));
 }
-
-/*
- * 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/signal_user.c b/arch/um/kernel/signal_user.c
deleted file mode 100644
index 62f4578..0000000
--- a/arch/um/kernel/signal_user.c
+++ /dev/null
@@ -1,157 +0,0 @@
-/* 
- * Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#include <stdio.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <signal.h>
-#include <errno.h>
-#include <stdarg.h>
-#include <string.h>
-#include <sys/mman.h>
-#include "user_util.h"
-#include "kern_util.h"
-#include "user.h"
-#include "signal_user.h"
-#include "signal_kern.h"
-#include "sysdep/sigcontext.h"
-#include "sigcontext.h"
-
-void set_sigstack(void *sig_stack, int size)
-{
-	stack_t stack = ((stack_t) { .ss_flags	= 0,
-				     .ss_sp	= (__ptr_t) sig_stack,
-				     .ss_size 	= size - sizeof(void *) });
-
-	if(sigaltstack(&stack, NULL) != 0)
-		panic("enabling signal stack failed, errno = %d\n", errno);
-}
-
-void set_handler(int sig, void (*handler)(int), int flags, ...)
-{
-	struct sigaction action;
-	va_list ap;
-	int mask;
-
-	va_start(ap, flags);
-	action.sa_handler = handler;
-	sigemptyset(&action.sa_mask);
-	while((mask = va_arg(ap, int)) != -1){
-		sigaddset(&action.sa_mask, mask);
-	}
-	va_end(ap);
-	action.sa_flags = flags;
-	action.sa_restorer = NULL;
-	if(sigaction(sig, &action, NULL) < 0)
-		panic("sigaction failed");
-}
-
-int change_sig(int signal, int on)
-{
-	sigset_t sigset, old;
-
-	sigemptyset(&sigset);
-	sigaddset(&sigset, signal);
-	sigprocmask(on ? SIG_UNBLOCK : SIG_BLOCK, &sigset, &old);
-	return(!sigismember(&old, signal));
-}
-
-/* Both here and in set/get_signal we don't touch SIGPROF, because we must not
- * disable profiling; it's safe because the profiling code does not interact
- * with the kernel code at all.*/
-
-static void change_signals(int type)
-{
-	sigset_t mask;
-
-	sigemptyset(&mask);
-	sigaddset(&mask, SIGVTALRM);
-	sigaddset(&mask, SIGALRM);
-	sigaddset(&mask, SIGIO);
-	if(sigprocmask(type, &mask, NULL) < 0)
-		panic("Failed to change signal mask - errno = %d", errno);
-}
-
-void block_signals(void)
-{
-	change_signals(SIG_BLOCK);
-}
-
-void unblock_signals(void)
-{
-	change_signals(SIG_UNBLOCK);
-}
-
-/* These are the asynchronous signals.  SIGVTALRM and SIGARLM are handled
- * together under SIGVTALRM_BIT.  SIGPROF is excluded because we want to
- * be able to profile all of UML, not just the non-critical sections.  If
- * profiling is not thread-safe, then that is not my problem.  We can disable
- * profiling when SMP is enabled in that case.
- */
-#define SIGIO_BIT 0
-#define SIGVTALRM_BIT 1
-
-static int enable_mask(sigset_t *mask)
-{
-	int sigs;
-
-	sigs = sigismember(mask, SIGIO) ? 0 : 1 << SIGIO_BIT;
-	sigs |= sigismember(mask, SIGVTALRM) ? 0 : 1 << SIGVTALRM_BIT;
-	sigs |= sigismember(mask, SIGALRM) ? 0 : 1 << SIGVTALRM_BIT;
-	return(sigs);
-}
-
-int get_signals(void)
-{
-	sigset_t mask;
-	
-	if(sigprocmask(SIG_SETMASK, NULL, &mask) < 0)
-		panic("Failed to get signal mask");
-	return(enable_mask(&mask));
-}
-
-int set_signals(int enable)
-{
-	sigset_t mask;
-	int ret;
-
-	sigemptyset(&mask);
-	if(enable & (1 << SIGIO_BIT)) 
-		sigaddset(&mask, SIGIO);
-	if(enable & (1 << SIGVTALRM_BIT)){
-		sigaddset(&mask, SIGVTALRM);
-		sigaddset(&mask, SIGALRM);
-	}
-
-	/* This is safe - sigprocmask is guaranteed to copy locally the
-	 * value of new_set, do his work and then, at the end, write to
-	 * old_set.
-	 */
-	if(sigprocmask(SIG_UNBLOCK, &mask, &mask) < 0)
-		panic("Failed to enable signals");
-	ret = enable_mask(&mask);
-	sigemptyset(&mask);
-	if((enable & (1 << SIGIO_BIT)) == 0) 
-		sigaddset(&mask, SIGIO);
-	if((enable & (1 << SIGVTALRM_BIT)) == 0){
-		sigaddset(&mask, SIGVTALRM);
-		sigaddset(&mask, SIGALRM);
-	}
-	if(sigprocmask(SIG_BLOCK, &mask, NULL) < 0)
-		panic("Failed to block signals");
-
-	return(ret);
-}
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/kernel/skas/Makefile b/arch/um/kernel/skas/Makefile
index 8de471b..57181a9 100644
--- a/arch/um/kernel/skas/Makefile
+++ b/arch/um/kernel/skas/Makefile
@@ -1,12 +1,12 @@
-# 
+#
 # Copyright (C) 2002 - 2004 Jeff Dike (jdike@addtoit.com)
 # Licensed under the GPL
 #
 
-obj-y := clone.o exec_kern.o mem.o mem_user.o mmu.o process.o process_kern.o \
-	syscall.o tlb.o trap_user.o uaccess.o
+obj-y := clone.o exec_kern.o mem.o mmu.o process_kern.o \
+	syscall.o tlb.o uaccess.o
 
-USER_OBJS := process.o clone.o
+USER_OBJS := clone.o
 
 include arch/um/scripts/Makefile.rules
 
diff --git a/arch/um/kernel/skas/include/mmu-skas.h b/arch/um/kernel/skas/include/mmu-skas.h
deleted file mode 100644
index 44110c5..0000000
--- a/arch/um/kernel/skas/include/mmu-skas.h
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#ifndef __SKAS_MMU_H
-#define __SKAS_MMU_H
-
-#include "linux/config.h"
-#include "mm_id.h"
-#include "asm/ldt.h"
-
-struct mmu_context_skas {
-	struct mm_id id;
-        unsigned long last_page_table;
-#ifdef CONFIG_3_LEVEL_PGTABLES
-        unsigned long last_pmd;
-#endif
-	uml_ldt_t ldt;
-};
-
-extern void switch_mm_skas(struct mm_id * mm_idp);
-
-#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/skas/include/mode-skas.h b/arch/um/kernel/skas/include/mode-skas.h
deleted file mode 100644
index bcd26a6..0000000
--- a/arch/um/kernel/skas/include/mode-skas.h
+++ /dev/null
@@ -1,33 +0,0 @@
-/*
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#ifndef __MODE_SKAS_H__
-#define __MODE_SKAS_H__
-
-#include <sysdep/ptrace.h>
-
-extern unsigned long exec_regs[];
-extern unsigned long exec_fp_regs[];
-extern unsigned long exec_fpx_regs[];
-extern int have_fpx_regs;
-
-extern void sig_handler_common_skas(int sig, void *sc_ptr);
-extern void halt_skas(void);
-extern void reboot_skas(void);
-extern void kill_off_processes_skas(void);
-extern int is_skas_winch(int pid, int fd, void *data);
-
-#endif
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/kernel/skas/include/skas.h b/arch/um/kernel/skas/include/skas.h
deleted file mode 100644
index daa2f85..0000000
--- a/arch/um/kernel/skas/include/skas.h
+++ /dev/null
@@ -1,50 +0,0 @@
-/* 
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#ifndef __SKAS_H
-#define __SKAS_H
-
-#include "mm_id.h"
-#include "sysdep/ptrace.h"
-
-extern int userspace_pid[];
-extern int proc_mm, ptrace_faultinfo, ptrace_ldt;
-extern int skas_needs_stub;
-
-extern void switch_threads(void *me, void *next);
-extern void thread_wait(void *sw, void *fb);
-extern void new_thread(void *stack, void **switch_buf_ptr, void **fork_buf_ptr,
-                       void (*handler)(int));
-extern int start_idle_thread(void *stack, void *switch_buf_ptr, 
-			     void **fork_buf_ptr);
-extern int user_thread(unsigned long stack, int flags);
-extern void userspace(union uml_pt_regs *regs);
-extern void new_thread_proc(void *stack, void (*handler)(int sig));
-extern void remove_sigstack(void);
-extern void new_thread_handler(int sig);
-extern void handle_syscall(union uml_pt_regs *regs);
-extern int map(struct mm_id * mm_idp, unsigned long virt,
-	       unsigned long len, int r, int w, int x, int phys_fd,
-	       unsigned long long offset, int done, void **data);
-extern int unmap(struct mm_id * mm_idp, void *addr, unsigned long len,
-		 int done, void **data);
-extern int protect(struct mm_id * mm_idp, unsigned long addr,
-		   unsigned long len, int r, int w, int x, int done,
-		   void **data);
-extern void user_signal(int sig, union uml_pt_regs *regs, int pid);
-extern int new_mm(int from, unsigned long stack);
-extern int start_userspace(unsigned long stub_stack);
-extern int copy_context_skas0(unsigned long stack, int pid);
-extern void get_skas_faultinfo(int pid, struct faultinfo * fi);
-extern long execute_syscall_skas(void *r);
-extern unsigned long current_stub_stack(void);
-extern long run_syscall_stub(struct mm_id * mm_idp,
-                             int syscall, unsigned long *args, long expected,
-                             void **addr, int done);
-extern long syscall_stub_data(struct mm_id * mm_idp,
-                              unsigned long *data, int data_count,
-                              void **addr, void **stub_addr);
-
-#endif
diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c
index 677871f..c5c9885 100644
--- a/arch/um/kernel/skas/mmu.c
+++ b/arch/um/kernel/skas/mmu.c
@@ -78,7 +78,7 @@ int init_new_context_skas(struct task_struct *task, struct mm_struct *mm)
  	struct mmu_context_skas *from_mm = NULL;
 	struct mmu_context_skas *to_mm = &mm->context.skas;
 	unsigned long stack = 0;
-	int from_fd, ret = -ENOMEM;
+	int ret = -ENOMEM;
 
 	if(skas_needs_stub){
 		stack = get_zeroed_page(GFP_KERNEL);
@@ -108,11 +108,7 @@ int init_new_context_skas(struct task_struct *task, struct mm_struct *mm)
 		from_mm = &current->mm->context.skas;
 
 	if(proc_mm){
-		if(from_mm)
-			from_fd = from_mm->id.u.mm_fd;
-		else from_fd = -1;
-
-		ret = new_mm(from_fd, stack);
+		ret = new_mm(stack);
 		if(ret < 0){
 			printk("init_new_context_skas - new_mm failed, "
 			       "errno = %d\n", ret);
diff --git a/arch/um/kernel/skas/process.c b/arch/um/kernel/skas/process.c
index 599d679..eea1c9c4 100644
--- a/arch/um/kernel/skas/process.c
+++ b/arch/um/kernel/skas/process.c
@@ -18,7 +18,6 @@
 #include <asm/types.h>
 #include "user.h"
 #include "ptrace_user.h"
-#include "time_user.h"
 #include "sysdep/ptrace.h"
 #include "user_util.h"
 #include "kern_util.h"
@@ -31,7 +30,6 @@
 #include "proc_mm.h"
 #include "skas_ptrace.h"
 #include "chan_user.h"
-#include "signal_user.h"
 #include "registers.h"
 #include "mem.h"
 #include "uml-config.h"
@@ -69,7 +67,7 @@ void wait_stub_done(int pid, int sig, char * fname)
 
         if((n < 0) || !WIFSTOPPED(status) ||
            (WSTOPSIG(status) != SIGUSR1 && WSTOPSIG(status) != SIGTRAP)){
-		unsigned long regs[FRAME_SIZE];
+		unsigned long regs[HOST_FRAME_SIZE];
 		if(ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
 			printk("Failed to get registers from stub, "
 			       "errno = %d\n", errno);
@@ -77,7 +75,7 @@ void wait_stub_done(int pid, int sig, char * fname)
 			int i;
 
 			printk("Stub registers -\n");
-			for(i = 0; i < FRAME_SIZE; i++)
+			for(i = 0; i < HOST_FRAME_SIZE; i++)
 				printk("\t%d - %lx\n", i, regs[i]);
 		}
                 panic("%s : failed to wait for SIGUSR1/SIGTRAP, "
@@ -514,16 +512,6 @@ int start_idle_thread(void *stack, void *switch_buf_ptr, void **fork_buf_ptr)
 	siglongjmp(**switch_buf, 1);
 }
 
-void remove_sigstack(void)
-{
-	stack_t stack = ((stack_t) { .ss_flags	= SS_DISABLE,
-				     .ss_sp	= NULL,
-				     .ss_size	= 0 });
-
-	if(sigaltstack(&stack, NULL) != 0)
-		panic("disabling signal stack failed, errno = %d\n", errno);
-}
-
 void initial_thread_cb_skas(void (*proc)(void *), void *arg)
 {
 	sigjmp_buf here;
diff --git a/arch/um/kernel/skas/process_kern.c b/arch/um/kernel/skas/process_kern.c
index 9c99025..3f70a2e 100644
--- a/arch/um/kernel/skas/process_kern.c
+++ b/arch/um/kernel/skas/process_kern.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -13,15 +13,12 @@
 #include "asm/uaccess.h"
 #include "asm/atomic.h"
 #include "kern_util.h"
-#include "time_user.h"
-#include "signal_user.h"
 #include "skas.h"
 #include "os.h"
 #include "user_util.h"
 #include "tlb.h"
 #include "kern.h"
 #include "mode.h"
-#include "proc_mm.h"
 #include "registers.h"
 
 void switch_to_skas(void *prev, void *next)
@@ -35,7 +32,7 @@ void switch_to_skas(void *prev, void *next)
 	if(current->pid == 0)
 		switch_timers(0);
 
-	switch_threads(&from->thread.mode.skas.switch_buf, 
+	switch_threads(&from->thread.mode.skas.switch_buf,
 		       to->thread.mode.skas.switch_buf);
 
 	if(current->pid == 0)
@@ -51,8 +48,8 @@ void new_thread_handler(int sig)
 
 	fn = current->thread.request.u.thread.proc;
 	arg = current->thread.request.u.thread.arg;
-	change_sig(SIGUSR1, 1);
-	thread_wait(&current->thread.mode.skas.switch_buf, 
+	os_usr1_signal(1);
+	thread_wait(&current->thread.mode.skas.switch_buf,
 		    current->thread.mode.skas.fork_buf);
 
 	if(current->thread.prev_sched != NULL)
@@ -83,8 +80,8 @@ void release_thread_skas(struct task_struct *task)
 
 void fork_handler(int sig)
 {
-        change_sig(SIGUSR1, 1);
- 	thread_wait(&current->thread.mode.skas.switch_buf, 
+	os_usr1_signal(1);
+	thread_wait(&current->thread.mode.skas.switch_buf,
 		    current->thread.mode.skas.fork_buf);
   	
 	force_flush_all();
@@ -94,13 +91,13 @@ void fork_handler(int sig)
 	schedule_tail(current->thread.prev_sched);
 	current->thread.prev_sched = NULL;
 
-	/* Handle any immediate reschedules or signals */
+/* Handle any immediate reschedules or signals */
 	interrupt_end();
 	userspace(&current->thread.regs.regs);
 }
 
 int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp,
-		     unsigned long stack_top, struct task_struct * p, 
+		     unsigned long stack_top, struct task_struct * p,
 		     struct pt_regs *regs)
 {
   	void (*handler)(int);
@@ -119,32 +116,19 @@ int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp,
 		handler = new_thread_handler;
 	}
 
-	new_thread(p->thread_info, &p->thread.mode.skas.switch_buf,
+	new_thread(task_stack_page(p), &p->thread.mode.skas.switch_buf,
 		   &p->thread.mode.skas.fork_buf, handler);
 	return(0);
 }
 
-extern void map_stub_pages(int fd, unsigned long code,
-			   unsigned long data, unsigned long stack);
-int new_mm(int from, unsigned long stack)
+int new_mm(unsigned long stack)
 {
-	struct proc_mm_op copy;
-	int n, fd;
+	int fd;
 
 	fd = os_open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0);
 	if(fd < 0)
 		return(fd);
 
-	if(from != -1){
-		copy = ((struct proc_mm_op) { .op 	= MM_COPY_SEGMENTS,
-					      .u 	=
-					      { .copy_segments	= from } } );
-		n = os_write_file(fd, &copy, sizeof(copy));
-		if(n != sizeof(copy))
-			printk("new_mm : /proc/mm copy_segments failed, "
-			       "err = %d\n", -n);
-	}
-
 	if(skas_needs_stub)
 		map_stub_pages(fd, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack);
 
@@ -186,7 +170,7 @@ int start_uml_skas(void)
 
 	init_task.thread.request.u.thread.proc = start_kernel_proc;
 	init_task.thread.request.u.thread.arg = NULL;
-	return(start_idle_thread(init_task.thread_info,
+	return(start_idle_thread(task_stack_page(&init_task),
 				 &init_task.thread.mode.skas.switch_buf,
 				 &init_task.thread.mode.skas.fork_buf));
 }
diff --git a/arch/um/kernel/skas/uaccess.c b/arch/um/kernel/skas/uaccess.c
index a5a4752..5992c32 100644
--- a/arch/um/kernel/skas/uaccess.c
+++ b/arch/um/kernel/skas/uaccess.c
@@ -13,7 +13,7 @@
 #include "asm/pgtable.h"
 #include "asm/uaccess.h"
 #include "kern_util.h"
-#include "user_util.h"
+#include "os.h"
 
 extern void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
 			     pte_t *pte_out);
diff --git a/arch/um/kernel/syscall.c b/arch/um/kernel/syscall.c
index 1429c13..1731d90 100644
--- a/arch/um/kernel/syscall.c
+++ b/arch/um/kernel/syscall.c
@@ -25,12 +25,12 @@ int record_syscall_start(int syscall)
 	syscall_record[index].syscall = syscall;
 	syscall_record[index].pid = current_pid();
 	syscall_record[index].result = 0xdeadbeef;
-	syscall_record[index].start = os_usecs();
+	syscall_record[index].start = os_nsecs();
 	return(index);
 }
 
 void record_syscall_end(int index, long result)
 {
 	syscall_record[index].result = result;
-	syscall_record[index].end = os_usecs();
+	syscall_record[index].end = os_nsecs();
 }
diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c
index c40b611..8fa2ae7 100644
--- a/arch/um/kernel/time.c
+++ b/arch/um/kernel/time.c
@@ -14,9 +14,9 @@
 #include "kern_util.h"
 #include "user.h"
 #include "process.h"
-#include "signal_user.h"
 #include "time_user.h"
 #include "kern_constants.h"
+#include "os.h"
 
 /* XXX This really needs to be declared and initialized in a kernel file since
  * it's in <linux/time.h>
@@ -99,7 +99,8 @@ void uml_idle_timer(void)
 	set_interval(ITIMER_REAL);
 }
 
-extern int do_posix_clock_monotonic_gettime(struct timespec *tp);
+extern void ktime_get_ts(struct timespec *ts);
+#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 
 void time_init(void)
 {
@@ -114,8 +115,8 @@ void time_init(void)
 	wall_to_monotonic.tv_nsec = -now.tv_nsec;
 }
 
-/* Declared in linux/time.h, which can't be included here */
-extern void clock_was_set(void);
+/* Defined in linux/ktimer.h, which can't be included here */
+#define clock_was_set()		do { } while (0)
 
 void do_gettimeofday(struct timeval *tv)
 {
diff --git a/arch/um/kernel/time_kern.c b/arch/um/kernel/time_kern.c
index 020ca79..3c7626c 100644
--- a/arch/um/kernel/time_kern.c
+++ b/arch/um/kernel/time_kern.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -13,12 +13,12 @@
 #include "linux/interrupt.h"
 #include "linux/init.h"
 #include "linux/delay.h"
+#include "linux/hrtimer.h"
 #include "asm/irq.h"
 #include "asm/param.h"
 #include "asm/current.h"
 #include "kern_util.h"
 #include "user_util.h"
-#include "time_user.h"
 #include "mode.h"
 #include "os.h"
 
@@ -39,7 +39,7 @@ unsigned long long sched_clock(void)
 int timer_irq_inited = 0;
 
 static int first_tick;
-static unsigned long long prev_usecs;
+static unsigned long long prev_nsecs;
 #ifdef CONFIG_UML_REAL_TIME_CLOCK
 static long long delta;   		/* Deviation per interval */
 #endif
@@ -58,23 +58,23 @@ void timer_irq(union uml_pt_regs *regs)
 	if(first_tick){
 #ifdef CONFIG_UML_REAL_TIME_CLOCK
 		/* We've had 1 tick */
-		unsigned long long usecs = os_usecs();
+		unsigned long long nsecs = os_nsecs();
 
-		delta += usecs - prev_usecs;
-		prev_usecs = usecs;
+		delta += nsecs - prev_nsecs;
+		prev_nsecs = nsecs;
 
 		/* Protect against the host clock being set backwards */
 		if(delta < 0)
 			delta = 0;
 
-		ticks += (delta * HZ) / MILLION;
-		delta -= (ticks * MILLION) / HZ;
+		ticks += (delta * HZ) / BILLION;
+		delta -= (ticks * BILLION) / HZ;
 #else
 		ticks = 1;
 #endif
 	}
 	else {
-		prev_usecs = os_usecs();
+		prev_nsecs = os_nsecs();
 		first_tick = 1;
 	}
 
@@ -84,49 +84,102 @@ void timer_irq(union uml_pt_regs *regs)
 	}
 }
 
-void boot_timer_handler(int sig)
+void do_boot_timer_handler(struct sigcontext * sc)
 {
 	struct pt_regs regs;
 
-	CHOOSE_MODE((void) 
-		    (UPT_SC(&regs.regs) = (struct sigcontext *) (&sig + 1)),
+	CHOOSE_MODE((void) (UPT_SC(&regs.regs) = sc),
 		    (void) (regs.regs.skas.is_user = 0));
 	do_timer(&regs);
 }
 
+static DEFINE_SPINLOCK(timer_spinlock);
+
+static unsigned long long local_offset = 0;
+
+static inline unsigned long long get_time(void)
+{
+	unsigned long long nsecs;
+	unsigned long flags;
+
+	spin_lock_irqsave(&timer_spinlock, flags);
+	nsecs = os_nsecs();
+	nsecs += local_offset;
+	spin_unlock_irqrestore(&timer_spinlock, flags);
+
+	return nsecs;
+}
+
 irqreturn_t um_timer(int irq, void *dev, struct pt_regs *regs)
 {
+	unsigned long long nsecs;
 	unsigned long flags;
 
 	do_timer(regs);
+
 	write_seqlock_irqsave(&xtime_lock, flags);
-	timer();
+	nsecs = get_time() + local_offset;
+	xtime.tv_sec = nsecs / NSEC_PER_SEC;
+	xtime.tv_nsec = nsecs - xtime.tv_sec * NSEC_PER_SEC;
 	write_sequnlock_irqrestore(&xtime_lock, flags);
+
 	return(IRQ_HANDLED);
 }
 
 long um_time(int __user *tloc)
 {
-	struct timeval now;
+	long ret = get_time() / NSEC_PER_SEC;
 
-	do_gettimeofday(&now);
-	if (tloc) {
- 		if (put_user(now.tv_sec, tloc))
-			now.tv_sec = -EFAULT;
-	}
-	return now.tv_sec;
+	if((tloc != NULL) && put_user(ret, tloc))
+		return -EFAULT;
+
+	return ret;
+}
+
+void do_gettimeofday(struct timeval *tv)
+{
+	unsigned long long nsecs = get_time();
+
+	tv->tv_sec = nsecs / NSEC_PER_SEC;
+	/* Careful about calculations here - this was originally done as
+	 * (nsecs - tv->tv_sec * NSEC_PER_SEC) / NSEC_PER_USEC
+	 * which gave bogus (> 1000000) values.  Dunno why, suspect gcc
+	 * (4.0.0) miscompiled it, or there's a subtle 64/32-bit conversion
+	 * problem that I missed.
+	 */
+	nsecs -= tv->tv_sec * NSEC_PER_SEC;
+	tv->tv_usec = (unsigned long) nsecs / NSEC_PER_USEC;
+}
+
+static inline void set_time(unsigned long long nsecs)
+{
+	unsigned long long now;
+	unsigned long flags;
+
+	spin_lock_irqsave(&timer_spinlock, flags);
+	now = os_nsecs();
+	local_offset = nsecs - now;
+	spin_unlock_irqrestore(&timer_spinlock, flags);
+
+	clock_was_set();
 }
 
 long um_stime(int __user *tptr)
 {
 	int value;
-	struct timespec new;
 
 	if (get_user(value, tptr))
                 return -EFAULT;
-	new.tv_sec = value;
-	new.tv_nsec = 0;
-	do_settimeofday(&new);
+
+	set_time((unsigned long long) value * NSEC_PER_SEC);
+
+	return 0;
+}
+
+int do_settimeofday(struct timespec *tv)
+{
+	set_time((unsigned long long) tv->tv_sec * NSEC_PER_SEC + tv->tv_nsec);
+
 	return 0;
 }
 
@@ -134,29 +187,15 @@ void timer_handler(int sig, union uml_pt_regs *regs)
 {
 	local_irq_disable();
 	irq_enter();
-	update_process_times(CHOOSE_MODE(user_context(UPT_SP(regs)),
-					 (regs)->skas.is_user));
+	update_process_times(CHOOSE_MODE(
+	                     (UPT_SC(regs) && user_context(UPT_SP(regs))),
+			     (regs)->skas.is_user));
 	irq_exit();
 	local_irq_enable();
 	if(current_thread->cpu == 0)
 		timer_irq(regs);
 }
 
-static DEFINE_SPINLOCK(timer_spinlock);
-
-unsigned long time_lock(void)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&timer_spinlock, flags);
-	return(flags);
-}
-
-void time_unlock(unsigned long flags)
-{
-	spin_unlock_irqrestore(&timer_spinlock, flags);
-}
-
 int __init timer_init(void)
 {
 	int err;
@@ -171,14 +210,3 @@ int __init timer_init(void)
 }
 
 __initcall(timer_init);
-
-/*
- * 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/trap_kern.c b/arch/um/kernel/trap_kern.c
index 0d4c10a..d56046c 100644
--- a/arch/um/kernel/trap_kern.c
+++ b/arch/um/kernel/trap_kern.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -26,9 +26,13 @@
 #include "mconsole_kern.h"
 #include "mem.h"
 #include "mem_kern.h"
+#include "sysdep/sigcontext.h"
+#include "sysdep/ptrace.h"
+#include "os.h"
 #ifdef CONFIG_MODE_SKAS
 #include "skas.h"
 #endif
+#include "os.h"
 
 /* Note this is constrained to return 0, -EFAULT, -EACCESS, -ENOMEM by segv(). */
 int handle_page_fault(unsigned long address, unsigned long ip, 
@@ -125,6 +129,25 @@ out_of_memory:
 	goto out;
 }
 
+void segv_handler(int sig, union uml_pt_regs *regs)
+{
+	struct faultinfo * fi = UPT_FAULTINFO(regs);
+
+	if(UPT_IS_USER(regs) && !SEGV_IS_FIXABLE(fi)){
+		bad_segv(*fi, UPT_IP(regs));
+		return;
+	}
+	segv(*fi, UPT_IP(regs), UPT_IS_USER(regs), regs);
+}
+
+struct kern_handlers handlinfo_kern = {
+	.relay_signal = relay_signal,
+	.winch = winch,
+	.bus_handler = relay_signal,
+	.page_fault = segv_handler,
+	.sigio_handler = sigio_handler,
+	.timer_handler = timer_handler
+};
 /*
  * We give a *copy* of the faultinfo in the regs to segv.
  * This must be done, since nesting SEGVs could overwrite
diff --git a/arch/um/kernel/trap_user.c b/arch/um/kernel/trap_user.c
deleted file mode 100644
index e9ccd6b..0000000
--- a/arch/um/kernel/trap_user.c
+++ /dev/null
@@ -1,98 +0,0 @@
-/* 
- * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#include <stdlib.h>
-#include <errno.h>
-#include <setjmp.h>
-#include <signal.h>
-#include <sys/time.h>
-#include <sys/wait.h>
-#include <asm/page.h>
-#include <asm/unistd.h>
-#include <asm/ptrace.h>
-#include "init.h"
-#include "sysdep/ptrace.h"
-#include "sigcontext.h"
-#include "sysdep/sigcontext.h"
-#include "irq_user.h"
-#include "signal_user.h"
-#include "time_user.h"
-#include "task.h"
-#include "mode.h"
-#include "choose-mode.h"
-#include "kern_util.h"
-#include "user_util.h"
-#include "os.h"
-
-void kill_child_dead(int pid)
-{
-	kill(pid, SIGKILL);
-	kill(pid, SIGCONT);
-	do {
-		int n;
-		CATCH_EINTR(n = waitpid(pid, NULL, 0));
-		if (n > 0)
-			kill(pid, SIGCONT);
-		else
-			break;
-	} while(1);
-}
-
-void segv_handler(int sig, union uml_pt_regs *regs)
-{
-        struct faultinfo * fi = UPT_FAULTINFO(regs);
-
-        if(UPT_IS_USER(regs) && !SEGV_IS_FIXABLE(fi)){
-                bad_segv(*fi, UPT_IP(regs));
-		return;
-	}
-        segv(*fi, UPT_IP(regs), UPT_IS_USER(regs), regs);
-}
-
-void usr2_handler(int sig, union uml_pt_regs *regs)
-{
-	CHOOSE_MODE(syscall_handler_tt(sig, regs), (void) 0);
-}
-
-struct signal_info sig_info[] = {
-	[ SIGTRAP ] { .handler 		= relay_signal,
-		      .is_irq 		= 0 },
-	[ SIGFPE ] { .handler 		= relay_signal,
-		     .is_irq 		= 0 },
-	[ SIGILL ] { .handler 		= relay_signal,
-		     .is_irq 		= 0 },
-	[ SIGWINCH ] { .handler		= winch,
-		       .is_irq		= 1 },
-	[ SIGBUS ] { .handler 		= bus_handler,
-		     .is_irq 		= 0 },
-	[ SIGSEGV] { .handler 		= segv_handler,
-		     .is_irq 		= 0 },
-	[ SIGIO ] { .handler 		= sigio_handler,
-		    .is_irq 		= 1 },
-	[ SIGVTALRM ] { .handler 	= timer_handler,
-			.is_irq 	= 1 },
-        [ SIGALRM ] { .handler          = timer_handler,
-                      .is_irq           = 1 },
-	[ SIGUSR2 ] { .handler 		= usr2_handler,
-		      .is_irq 		= 0 },
-};
-
-void do_longjmp(void *b, int val)
-{
-	sigjmp_buf *buf = b;
-
-	siglongjmp(*buf, val);
-}
-
-/*
- * 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/tt/exec_kern.c b/arch/um/kernel/tt/exec_kern.c
index 065b504..5c1e4cc 100644
--- a/arch/um/kernel/tt/exec_kern.c
+++ b/arch/um/kernel/tt/exec_kern.c
@@ -13,8 +13,6 @@
 #include "user_util.h"
 #include "kern_util.h"
 #include "irq_user.h"
-#include "time_user.h"
-#include "signal_user.h"
 #include "mem_user.h"
 #include "os.h"
 #include "tlb.h"
@@ -40,7 +38,7 @@ void flush_thread_tt(void)
 		do_exit(SIGKILL);
 	}
 		
-	new_pid = start_fork_tramp(current->thread_info, stack, 0, exec_tramp);
+	new_pid = start_fork_tramp(task_stack_page(current), stack, 0, exec_tramp);
 	if(new_pid < 0){
 		printk(KERN_ERR 
 		       "flush_thread : new thread failed, errno = %d\n",
diff --git a/arch/um/kernel/tt/gdb.c b/arch/um/kernel/tt/gdb.c
index 37e22d7..786e4ed 100644
--- a/arch/um/kernel/tt/gdb.c
+++ b/arch/um/kernel/tt/gdb.c
@@ -20,6 +20,7 @@
 #include "user_util.h"
 #include "tt.h"
 #include "sysdep/thread.h"
+#include "os.h"
 
 extern int debugger_pid;
 extern int debugger_fd;
diff --git a/arch/um/kernel/tt/include/mmu-tt.h b/arch/um/kernel/tt/include/mmu-tt.h
deleted file mode 100644
index 0440510..0000000
--- a/arch/um/kernel/tt/include/mmu-tt.h
+++ /dev/null
@@ -1,23 +0,0 @@
-/*
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#ifndef __TT_MMU_H
-#define __TT_MMU_H
-
-struct mmu_context_tt {
-};
-
-#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/tt/process_kern.c b/arch/um/kernel/tt/process_kern.c
index cfaa373a..295c1ac 100644
--- a/arch/um/kernel/tt/process_kern.c
+++ b/arch/um/kernel/tt/process_kern.c
@@ -13,13 +13,11 @@
 #include "asm/ptrace.h"
 #include "asm/tlbflush.h"
 #include "irq_user.h"
-#include "signal_user.h"
 #include "kern_util.h"
 #include "user_util.h"
 #include "os.h"
 #include "kern.h"
 #include "sigcontext.h"
-#include "time_user.h"
 #include "mem_user.h"
 #include "tlb.h"
 #include "mode.h"
@@ -37,7 +35,7 @@ void switch_to_tt(void *prev, void *next)
 	from = prev;
 	to = next;
 
-	cpu = from->thread_info->cpu;
+	cpu = task_thread_info(from)->cpu;
 	if(cpu == 0)
 		forward_interrupts(to->thread.mode.tt.extern_pid);
 #ifdef CONFIG_SMP
@@ -254,7 +252,7 @@ int copy_thread_tt(int nr, unsigned long clone_flags, unsigned long sp,
 
 	clone_flags &= CLONE_VM;
 	p->thread.temp_stack = stack;
-	new_pid = start_fork_tramp(p->thread_info, stack, clone_flags, tramp);
+	new_pid = start_fork_tramp(task_stack_page(p), stack, clone_flags, tramp);
 	if(new_pid < 0){
 		printk(KERN_ERR "copy_thread : clone failed - errno = %d\n", 
 		       -new_pid);
@@ -344,7 +342,7 @@ int do_proc_op(void *t, int proc_id)
 		pid = thread->request.u.exec.pid;
 		do_exec(thread->mode.tt.extern_pid, pid);
 		thread->mode.tt.extern_pid = pid;
-		cpu_tasks[task->thread_info->cpu].pid = pid;
+		cpu_tasks[task_thread_info(task)->cpu].pid = pid;
 		break;
 	case OP_FORK:
 		attach_process(thread->request.u.fork.pid);
@@ -426,7 +424,7 @@ int start_uml_tt(void)
 	int pages;
 
 	pages = (1 << CONFIG_KERNEL_STACK_ORDER);
-	sp = (void *) ((unsigned long) init_task.thread_info) +
+	sp = task_stack_page(&init_task) +
 		pages * PAGE_SIZE - sizeof(unsigned long);
 	return(tracer(start_kernel_proc, sp));
 }
diff --git a/arch/um/kernel/tt/ptproxy/ptrace.c b/arch/um/kernel/tt/ptproxy/ptrace.c
index 528a5fc..0377442 100644
--- a/arch/um/kernel/tt/ptproxy/ptrace.c
+++ b/arch/um/kernel/tt/ptproxy/ptrace.c
@@ -20,6 +20,7 @@ Jeff Dike (jdike@karaya.com) : Modified for integration into uml
 #include "kern_util.h"
 #include "ptrace_user.h"
 #include "tt.h"
+#include "os.h"
 
 long proxy_ptrace(struct debugger *debugger, int arg1, pid_t arg2,
 		  long arg3, long arg4, pid_t child, int *ret)
diff --git a/arch/um/kernel/tt/ptproxy/sysdep.c b/arch/um/kernel/tt/ptproxy/sysdep.c
index a5f0e01..99f1783 100644
--- a/arch/um/kernel/tt/ptproxy/sysdep.c
+++ b/arch/um/kernel/tt/ptproxy/sysdep.c
@@ -15,6 +15,7 @@ terms and conditions.
 #include "ptrace_user.h"
 #include "user_util.h"
 #include "user.h"
+#include "os.h"
 
 int get_syscall(pid_t pid, long *arg1, long *arg2, long *arg3, long *arg4, 
 		long *arg5)
diff --git a/arch/um/kernel/tt/tracer.c b/arch/um/kernel/tt/tracer.c
index d11e739..71daae2 100644
--- a/arch/um/kernel/tt/tracer.c
+++ b/arch/um/kernel/tt/tracer.c
@@ -19,7 +19,6 @@
 #include "sigcontext.h"
 #include "sysdep/sigcontext.h"
 #include "os.h"
-#include "signal_user.h"
 #include "user_util.h"
 #include "mem_user.h"
 #include "process.h"
diff --git a/arch/um/kernel/tt/trap_user.c b/arch/um/kernel/tt/trap_user.c
index fc10861..b5d9d64 100644
--- a/arch/um/kernel/tt/trap_user.c
+++ b/arch/um/kernel/tt/trap_user.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -8,18 +8,18 @@
 #include <signal.h>
 #include "sysdep/ptrace.h"
 #include "sysdep/sigcontext.h"
-#include "signal_user.h"
 #include "user_util.h"
 #include "kern_util.h"
 #include "task.h"
 #include "tt.h"
+#include "os.h"
 
 void sig_handler_common_tt(int sig, void *sc_ptr)
 {
 	struct sigcontext *sc = sc_ptr;
 	struct tt_regs save_regs, *r;
-	struct signal_info *info;
-	int save_errno = errno, is_user;
+	int save_errno = errno, is_user = 0;
+	void (*handler)(int, union uml_pt_regs *);
 
 	/* This is done because to allow SIGSEGV to be delivered inside a SEGV
 	 * handler.  This can happen in copy_user, and if SEGV is disabled,
@@ -35,15 +35,20 @@ void sig_handler_common_tt(int sig, void *sc_ptr)
                 GET_FAULTINFO_FROM_SC(r->faultinfo, sc);
         }
 	save_regs = *r;
-	is_user = user_context(SC_SP(sc));
+	if (sc)
+		is_user = user_context(SC_SP(sc));
 	r->sc = sc;
 	if(sig != SIGUSR2) 
 		r->syscall = -1;
 
-	info = &sig_info[sig];
-	if(!info->is_irq) unblock_signals();
+	handler = sig_info[sig];
+
+	/* unblock SIGALRM, SIGVTALRM, SIGIO if sig isn't IRQ signal */
+	if (sig != SIGIO && sig != SIGWINCH &&
+	    sig != SIGVTALRM && sig != SIGALRM)
+		unblock_signals();
 
-	(*info->handler)(sig, (union uml_pt_regs *) r);
+	handler(sig, (union uml_pt_regs *) r);
 
 	if(is_user){
 		interrupt_end();
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 26626b2b..e2d3ca4 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2000, 2002 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -243,10 +243,6 @@ static int __init mode_tt_setup(char *line, int *add)
 	return(0);
 }
 
-#else
-
-#error Either CONFIG_MODE_TT or CONFIG_MODE_SKAS must be enabled
-
 #endif
 #endif
 #endif
@@ -363,6 +359,11 @@ int linux_main(int argc, char **argv)
 	uml_start = CHOOSE_MODE_PROC(set_task_sizes_tt, set_task_sizes_skas, 0,
 				     &host_task_size, &task_size);
 
+	/*
+ 	 * Setting up handlers to 'sig_info' struct
+ 	 */
+	os_fill_handlinfo(handlinfo_kern);
+
 	brk_start = (unsigned long) sbrk(0);
 	CHOOSE_MODE_PROC(before_mem_tt, before_mem_skas, brk_start);
 	/* Increase physical memory size for exec-shield users
diff --git a/arch/um/os-Linux/Makefile b/arch/um/os-Linux/Makefile
index 11e30b13..08a4e62 100644
--- a/arch/um/os-Linux/Makefile
+++ b/arch/um/os-Linux/Makefile
@@ -4,11 +4,13 @@
 #
 
 obj-y = aio.o elf_aux.o file.o helper.o main.o mem.o process.o signal.o \
-	start_up.o time.o tt.o tty.o uaccess.o umid.o user_syms.o drivers/ \
-	sys-$(SUBARCH)/
+	start_up.o time.o trap.o tt.o tty.o uaccess.o umid.o user_syms.o \
+	util.o drivers/ sys-$(SUBARCH)/
+
+obj-$(CONFIG_MODE_SKAS) += skas/
 
 USER_OBJS := aio.o elf_aux.o file.o helper.o main.o mem.o process.o signal.o \
-	start_up.o time.o tt.o tty.o uaccess.o umid.o
+	start_up.o time.o trap.o tt.o tty.o uaccess.o umid.o util.o
 
 elf_aux.o: $(ARCH_DIR)/kernel-offsets.h
 CFLAGS_elf_aux.o += -I$(objtree)/arch/um
diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c
index 36cc847..6490a4f 100644
--- a/arch/um/os-Linux/helper.c
+++ b/arch/um/os-Linux/helper.c
@@ -60,7 +60,7 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv,
 
 	if((stack_out != NULL) && (*stack_out != 0))
 		stack = *stack_out;
-	else stack = alloc_stack(0, um_in_interrupt());
+	else stack = alloc_stack(0, __cant_sleep());
 	if(stack == 0)
 		return(-ENOMEM);
 
@@ -124,7 +124,7 @@ int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags,
 	unsigned long stack, sp;
 	int pid, status, err;
 
-	stack = alloc_stack(stack_order, um_in_interrupt());
+	stack = alloc_stack(stack_order, __cant_sleep());
 	if(stack == 0) return(-ENOMEM);
 
 	sp = stack + (page_size() << stack_order) - sizeof(void *);
diff --git a/arch/um/os-Linux/main.c b/arch/um/os-Linux/main.c
index 23da27d..2878e89 100644
--- a/arch/um/os-Linux/main.c
+++ b/arch/um/os-Linux/main.c
@@ -16,8 +16,6 @@
 #include "user_util.h"
 #include "kern_util.h"
 #include "mem_user.h"
-#include "signal_user.h"
-#include "time_user.h"
 #include "irq_user.h"
 #include "user.h"
 #include "init.h"
@@ -83,20 +81,8 @@ extern void scan_elf_aux( char **envp);
 int main(int argc, char **argv, char **envp)
 {
 	char **new_argv;
-	sigset_t mask;
 	int ret, i, err;
 
-	/* Enable all signals except SIGIO - in some environments, we can
-	 * enter with some signals blocked
-	 */
-
-	sigemptyset(&mask);
-	sigaddset(&mask, SIGIO);
-	if(sigprocmask(SIG_SETMASK, &mask, NULL) < 0){
-		perror("sigprocmask");
-		exit(1);
-	}
-
 #ifdef UML_CONFIG_CMDLINE_ON_HOST
 	/* Allocate memory for thread command lines */
 	if(argc < 2 || strlen(argv[1]) < THREAD_NAME_LEN - 1){
diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c
index d9c5238..7f5e2da 100644
--- a/arch/um/os-Linux/process.c
+++ b/arch/um/os-Linux/process.c
@@ -15,10 +15,10 @@
 #include "os.h"
 #include "user.h"
 #include "user_util.h"
-#include "signal_user.h"
 #include "process.h"
 #include "irq_user.h"
 #include "kern_util.h"
+#include "longjmp.h"
 
 #define ARBITRARY_ADDR -1
 #define FAILURE_PID    -1
@@ -206,24 +206,13 @@ void init_new_thread_signals(int altstack)
 
 int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr)
 {
-       sigjmp_buf buf;
-       int n;
-
-       *jmp_ptr = &buf;
-       n = sigsetjmp(buf, 1);
-       if(n != 0)
-               return(n);
-       (*fn)(arg);
-       return(0);
+	sigjmp_buf buf;
+	int n, enable;
+
+	*jmp_ptr = &buf;
+	n = UML_SIGSETJMP(&buf, enable);
+	if(n != 0)
+		return(n);
+	(*fn)(arg);
+	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/os-Linux/signal.c b/arch/um/os-Linux/signal.c
index c7bfd5e..f11b312 100644
--- a/arch/um/os-Linux/signal.c
+++ b/arch/um/os-Linux/signal.c
@@ -4,27 +4,74 @@
  */
 
 #include <signal.h>
-#include "time_user.h"
-#include "mode.h"
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <string.h>
+#include <sys/mman.h>
+#include "user_util.h"
+#include "user.h"
+#include "signal_kern.h"
+#include "sysdep/sigcontext.h"
 #include "sysdep/signal.h"
+#include "sigcontext.h"
+#include "mode.h"
+#include "os.h"
+
+/* These are the asynchronous signals.  SIGVTALRM and SIGARLM are handled
+ * together under SIGVTALRM_BIT.  SIGPROF is excluded because we want to
+ * be able to profile all of UML, not just the non-critical sections.  If
+ * profiling is not thread-safe, then that is not my problem.  We can disable
+ * profiling when SMP is enabled in that case.
+ */
+#define SIGIO_BIT 0
+#define SIGIO_MASK (1 << SIGIO_BIT)
+
+#define SIGVTALRM_BIT 1
+#define SIGVTALRM_MASK (1 << SIGVTALRM_BIT)
+
+#define SIGALRM_BIT 2
+#define SIGALRM_MASK (1 << SIGALRM_BIT)
+
+static int signals_enabled = 1;
+static int pending = 0;
 
 void sig_handler(ARCH_SIGHDLR_PARAM)
 {
 	struct sigcontext *sc;
+	int enabled;
+
+	/* Must be the first thing that this handler does - x86_64 stores
+	 * the sigcontext in %rdx, and we need to save it before it has a
+	 * chance to get trashed.
+	 */
 
 	ARCH_GET_SIGCONTEXT(sc, sig);
+
+	enabled = signals_enabled;
+	if(!enabled && (sig == SIGIO)){
+		pending |= SIGIO_MASK;
+		return;
+	}
+
+	block_signals();
+
 	CHOOSE_MODE_PROC(sig_handler_common_tt, sig_handler_common_skas,
 			 sig, sc);
+
+	set_signals(enabled);
 }
 
 extern int timer_irq_inited;
 
-void alarm_handler(ARCH_SIGHDLR_PARAM)
+static void real_alarm_handler(int sig, struct sigcontext *sc)
 {
-	struct sigcontext *sc;
-
-	ARCH_GET_SIGCONTEXT(sc, sig);
-	if(!timer_irq_inited) return;
+	if(!timer_irq_inited){
+		signals_enabled = 1;
+		return;
+	}
 
 	if(sig == SIGALRM)
 		switch_timers(0);
@@ -34,15 +81,180 @@ void alarm_handler(ARCH_SIGHDLR_PARAM)
 
 	if(sig == SIGALRM)
 		switch_timers(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:
- */
+void alarm_handler(ARCH_SIGHDLR_PARAM)
+{
+	struct sigcontext *sc;
+	int enabled;
+
+	ARCH_GET_SIGCONTEXT(sc, sig);
+
+	enabled = signals_enabled;
+	if(!signals_enabled){
+		if(sig == SIGVTALRM)
+			pending |= SIGVTALRM_MASK;
+		else pending |= SIGALRM_MASK;
+
+		return;
+	}
+
+	block_signals();
+
+	real_alarm_handler(sig, sc);
+	set_signals(enabled);
+}
+
+extern void do_boot_timer_handler(struct sigcontext * sc);
+
+void boot_timer_handler(ARCH_SIGHDLR_PARAM)
+{
+	struct sigcontext *sc;
+	int enabled;
+
+	ARCH_GET_SIGCONTEXT(sc, sig);
+
+	enabled = signals_enabled;
+	if(!enabled){
+		if(sig == SIGVTALRM)
+			pending |= SIGVTALRM_MASK;
+		else pending |= SIGALRM_MASK;
+		return;
+	}
+
+	block_signals();
+
+	do_boot_timer_handler(sc);
+	set_signals(enabled);
+}
+
+void set_sigstack(void *sig_stack, int size)
+{
+	stack_t stack = ((stack_t) { .ss_flags	= 0,
+				     .ss_sp	= (__ptr_t) sig_stack,
+				     .ss_size 	= size - sizeof(void *) });
+
+	if(sigaltstack(&stack, NULL) != 0)
+		panic("enabling signal stack failed, errno = %d\n", errno);
+}
+
+void remove_sigstack(void)
+{
+	stack_t stack = ((stack_t) { .ss_flags	= SS_DISABLE,
+				     .ss_sp	= NULL,
+				     .ss_size	= 0 });
+
+	if(sigaltstack(&stack, NULL) != 0)
+		panic("disabling signal stack failed, errno = %d\n", errno);
+}
+
+void set_handler(int sig, void (*handler)(int), int flags, ...)
+{
+	struct sigaction action;
+	va_list ap;
+	sigset_t sig_mask;
+	int mask;
+
+	va_start(ap, flags);
+	action.sa_handler = handler;
+	sigemptyset(&action.sa_mask);
+	while((mask = va_arg(ap, int)) != -1){
+		sigaddset(&action.sa_mask, mask);
+	}
+	va_end(ap);
+	action.sa_flags = flags;
+	action.sa_restorer = NULL;
+	if(sigaction(sig, &action, NULL) < 0)
+		panic("sigaction failed - errno = %d\n", errno);
+
+	sigemptyset(&sig_mask);
+	sigaddset(&sig_mask, sig);
+	if(sigprocmask(SIG_UNBLOCK, &sig_mask, NULL) < 0)
+		panic("sigprocmask failed - errno = %d\n", errno);
+}
+
+int change_sig(int signal, int on)
+{
+	sigset_t sigset, old;
+
+	sigemptyset(&sigset);
+	sigaddset(&sigset, signal);
+	sigprocmask(on ? SIG_UNBLOCK : SIG_BLOCK, &sigset, &old);
+	return(!sigismember(&old, signal));
+}
+
+void block_signals(void)
+{
+	signals_enabled = 0;
+}
+
+void unblock_signals(void)
+{
+	int save_pending;
+
+	if(signals_enabled == 1)
+		return;
+
+	/* We loop because the IRQ handler returns with interrupts off.  So,
+	 * interrupts may have arrived and we need to re-enable them and
+	 * recheck pending.
+	 */
+	while(1){
+		/* Save and reset save_pending after enabling signals.  This
+		 * way, pending won't be changed while we're reading it.
+		 */
+		signals_enabled = 1;
+
+		save_pending = pending;
+		if(save_pending == 0)
+			return;
+
+		pending = 0;
+
+		/* We have pending interrupts, so disable signals, as the
+		 * handlers expect them off when they are called.  They will
+		 * be enabled again above.
+		 */
+
+		signals_enabled = 0;
+
+		/* Deal with SIGIO first because the alarm handler might
+		 * schedule, leaving the pending SIGIO stranded until we come
+		 * back here.
+		 */
+		if(save_pending & SIGIO_MASK)
+			CHOOSE_MODE_PROC(sig_handler_common_tt,
+					 sig_handler_common_skas, SIGIO, NULL);
+
+		if(save_pending & SIGALRM_MASK)
+			real_alarm_handler(SIGALRM, NULL);
+
+		if(save_pending & SIGVTALRM_MASK)
+			real_alarm_handler(SIGVTALRM, NULL);
+	}
+}
+
+int get_signals(void)
+{
+	return signals_enabled;
+}
+
+int set_signals(int enable)
+{
+	int ret;
+	if(signals_enabled == enable)
+		return enable;
+
+	ret = signals_enabled;
+	if(enable)
+		unblock_signals();
+	else block_signals();
+
+	return ret;
+}
+
+void os_usr1_signal(int on)
+{
+	change_sig(SIGUSR1, on);
+}
diff --git a/arch/um/os-Linux/skas/Makefile b/arch/um/os-Linux/skas/Makefile
new file mode 100644
index 0000000..5fd8d4d
--- /dev/null
+++ b/arch/um/os-Linux/skas/Makefile
@@ -0,0 +1,10 @@
+#
+# Copyright (C) 2002 - 2004 Jeff Dike (jdike@addtoit.com)
+# Licensed under the GPL
+#
+
+obj-y := mem.o process.o trap.o
+
+USER_OBJS := mem.o process.o trap.o
+
+include arch/um/scripts/Makefile.rules
diff --git a/arch/um/kernel/skas/mem_user.c b/arch/um/os-Linux/skas/mem.c
index 1d89640..9890e90 100644
--- a/arch/um/kernel/skas/mem_user.c
+++ b/arch/um/os-Linux/skas/mem.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -32,7 +32,7 @@ extern void wait_stub_done(int pid, int sig, char * fname);
 static inline unsigned long *check_init_stack(struct mm_id * mm_idp,
 					      unsigned long *stack)
 {
-	if(stack == NULL){
+	if(stack == NULL) {
 		stack = (unsigned long *) mm_idp->stack + 2;
 		*stack = 0;
 	}
@@ -45,13 +45,14 @@ int single_count = 0;
 int multi_count = 0;
 int multi_op_count = 0;
 
-static long do_syscall_stub(struct mm_id *mm_idp, void **addr)
+static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
 {
 	unsigned long regs[MAX_REG_NR];
-	unsigned long *data;
-	unsigned long *syscall;
+	int n;
 	long ret, offset;
-        int n, pid = mm_idp->u.pid;
+	unsigned long * data;
+	unsigned long * syscall;
+	int pid = mm_idp->u.pid;
 
 	if(proc_mm)
 #warning Need to look up userspace_pid by cpu
@@ -59,10 +60,11 @@ static long do_syscall_stub(struct mm_id *mm_idp, void **addr)
 
 	multi_count++;
 
-        get_safe_registers(regs);
-        regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
+	get_safe_registers(regs);
+	regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
 		((unsigned long) &batch_syscall_stub -
-                 (unsigned long) &__syscall_stub_start);
+		 (unsigned long) &__syscall_stub_start);
+
 	n = ptrace_setregs(pid, regs);
 	if(n < 0)
 		panic("do_syscall_stub : PTRACE_SETREGS failed, errno = %d\n",
@@ -80,6 +82,8 @@ static long do_syscall_stub(struct mm_id *mm_idp, void **addr)
 	if (offset) {
 		data = (unsigned long *)(mm_idp->stack +
 					 offset - UML_CONFIG_STUB_DATA);
+		printk("do_syscall_stub : ret = %d, offset = %d, "
+		       "data = 0x%x\n", ret, offset, data);
 		syscall = (unsigned long *)((unsigned long)data + data[0]);
 		printk("do_syscall_stub: syscall %ld failed, return value = "
 		       "0x%lx, expected return value = 0x%lx\n",
@@ -107,32 +111,32 @@ static long do_syscall_stub(struct mm_id *mm_idp, void **addr)
 
 long run_syscall_stub(struct mm_id * mm_idp, int syscall,
 		      unsigned long *args, long expected, void **addr,
- 		      int done)
+		      int done)
 {
- 	unsigned long *stack = check_init_stack(mm_idp, *addr);
+	unsigned long *stack = check_init_stack(mm_idp, *addr);
 
 	if(done && *addr == NULL)
 		single_count++;
 
- 	*stack += sizeof(long);
+	*stack += sizeof(long);
 	stack += *stack / sizeof(long);
 
-        *stack++ = syscall;
-        *stack++ = args[0];
-        *stack++ = args[1];
-        *stack++ = args[2];
-        *stack++ = args[3];
-        *stack++ = args[4];
-        *stack++ = args[5];
+	*stack++ = syscall;
+	*stack++ = args[0];
+	*stack++ = args[1];
+	*stack++ = args[2];
+	*stack++ = args[3];
+	*stack++ = args[4];
+	*stack++ = args[5];
 	*stack++ = expected;
-        *stack = 0;
-        multi_op_count++;
+	*stack = 0;
+	multi_op_count++;
 
-        if(!done && ((((unsigned long) stack) & ~PAGE_MASK) <
+	if(!done && ((((unsigned long) stack) & ~PAGE_MASK) <
 		     PAGE_SIZE - 10 * sizeof(long))){
 		*addr = stack;
-                return 0;
-        }
+		return 0;
+	}
 
 	return do_syscall_stub(mm_idp, addr);
 }
@@ -150,7 +154,7 @@ long syscall_stub_data(struct mm_id * mm_idp,
 	if((((unsigned long) *addr) & ~PAGE_MASK) >=
 	   PAGE_SIZE - (10 + data_count) * sizeof(long)) {
 		ret = do_syscall_stub(mm_idp, addr);
- 		/* in case of error, don't overwrite data on stack */
+		/* in case of error, don't overwrite data on stack */
 		if(ret)
 			return ret;
 	}
@@ -172,39 +176,39 @@ int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len,
 	int r, int w, int x, int phys_fd, unsigned long long offset,
 	int done, void **data)
 {
-        int prot, ret;
-
-        prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
-                (x ? PROT_EXEC : 0);
-
-        if(proc_mm){
-                struct proc_mm_op map;
-                int fd = mm_idp->u.mm_fd;
-
-                map = ((struct proc_mm_op) { .op	= MM_MMAP,
-                                             .u		=
-                                             { .mmap	=
-                                               { .addr	= virt,
-                                                 .len	= len,
-                                                 .prot	= prot,
-                                                 .flags	= MAP_SHARED |
-                                                 MAP_FIXED,
-                                                 .fd	= phys_fd,
-                                                 .offset= offset
-                                               } } } );
+	int prot, ret;
+
+	prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
+		(x ? PROT_EXEC : 0);
+
+	if(proc_mm){
+		struct proc_mm_op map;
+		int fd = mm_idp->u.mm_fd;
+
+		map = ((struct proc_mm_op) { .op	= MM_MMAP,
+				       .u		=
+				       { .mmap	=
+					 { .addr	= virt,
+					   .len	= len,
+					   .prot	= prot,
+					   .flags	= MAP_SHARED |
+					   MAP_FIXED,
+					   .fd	= phys_fd,
+					   .offset= offset
+					 } } } );
 		ret = os_write_file(fd, &map, sizeof(map));
 		if(ret != sizeof(map))
 			printk("map : /proc/mm map failed, err = %d\n", -ret);
 		else ret = 0;
-        }
-        else {
-                unsigned long args[] = { virt, len, prot,
-                                         MAP_SHARED | MAP_FIXED, phys_fd,
-                                         MMAP_OFFSET(offset) };
+	}
+	else {
+		unsigned long args[] = { virt, len, prot,
+					 MAP_SHARED | MAP_FIXED, phys_fd,
+					 MMAP_OFFSET(offset) };
 
 		ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt,
 				       data, done);
-        }
+	}
 
 	return ret;
 }
@@ -212,68 +216,66 @@ int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len,
 int unmap(struct mm_id * mm_idp, void *addr, unsigned long len, int done,
 	  void **data)
 {
-        int ret;
-
-        if(proc_mm){
-                struct proc_mm_op unmap;
-                int fd = mm_idp->u.mm_fd;
-
-                unmap = ((struct proc_mm_op) { .op	= MM_MUNMAP,
-                                               .u	=
-                                               { .munmap	=
-                                                 { .addr	=
-                                                   (unsigned long) addr,
-                                                   .len		= len } } } );
+	int ret;
+
+	if(proc_mm){
+		struct proc_mm_op unmap;
+		int fd = mm_idp->u.mm_fd;
+
+		unmap = ((struct proc_mm_op) { .op	= MM_MUNMAP,
+					 .u	=
+					 { .munmap	=
+					   { .addr	=
+					     (unsigned long) addr,
+					     .len		= len } } } );
 		ret = os_write_file(fd, &unmap, sizeof(unmap));
 		if(ret != sizeof(unmap))
 			printk("unmap - proc_mm write returned %d\n", ret);
 		else ret = 0;
-        }
-        else {
-                unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0,
-                                         0 };
+	}
+	else {
+		unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0,
+					 0 };
 
 		ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0,
 				       data, done);
-                if(ret < 0)
-                        printk("munmap stub failed, errno = %d\n", ret);
-        }
+	}
 
-        return ret;
+	return ret;
 }
 
 int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
 	    int r, int w, int x, int done, void **data)
 {
-        struct proc_mm_op protect;
-        int prot, ret;
-
-        prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
-                (x ? PROT_EXEC : 0);
-
-        if(proc_mm){
-                int fd = mm_idp->u.mm_fd;
-                protect = ((struct proc_mm_op) { .op	= MM_MPROTECT,
-                                                 .u	=
-                                                 { .mprotect	=
-                                                   { .addr	=
-                                                     (unsigned long) addr,
-                                                     .len	= len,
-                                                     .prot	= prot } } } );
-
-                ret = os_write_file(fd, &protect, sizeof(protect));
-                if(ret != sizeof(protect))
-                        printk("protect failed, err = %d", -ret);
-                else ret = 0;
-        }
-        else {
-                unsigned long args[] = { addr, len, prot, 0, 0, 0 };
-
-                ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
-                                       data, done);
-        }
-
-        return ret;
+	struct proc_mm_op protect;
+	int prot, ret;
+
+	prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
+		(x ? PROT_EXEC : 0);
+	if(proc_mm){
+		int fd = mm_idp->u.mm_fd;
+
+		protect = ((struct proc_mm_op) { .op	= MM_MPROTECT,
+					   .u	=
+					   { .mprotect	=
+					     { .addr	=
+					       (unsigned long) addr,
+					       .len	= len,
+					       .prot	= prot } } } );
+
+		ret = os_write_file(fd, &protect, sizeof(protect));
+		if(ret != sizeof(protect))
+			printk("protect failed, err = %d", -ret);
+		else ret = 0;
+	}
+	else {
+		unsigned long args[] = { addr, len, prot, 0, 0, 0 };
+
+		ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
+				       data, done);
+	}
+
+	return ret;
 }
 
 void before_mem_skas(unsigned long unused)
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
new file mode 100644
index 0000000..120a21c
--- /dev/null
+++ b/arch/um/os-Linux/skas/process.c
@@ -0,0 +1,566 @@
+/*
+ * Copyright (C) 2002- 2004 Jeff Dike (jdike@addtoit.com)
+ * Licensed under the GPL
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <setjmp.h>
+#include <sched.h>
+#include "ptrace_user.h"
+#include <sys/wait.h>
+#include <sys/mman.h>
+#include <sys/user.h>
+#include <sys/time.h>
+#include <asm/unistd.h>
+#include <asm/types.h>
+#include "user.h"
+#include "sysdep/ptrace.h"
+#include "user_util.h"
+#include "kern_util.h"
+#include "skas.h"
+#include "stub-data.h"
+#include "mm_id.h"
+#include "sysdep/sigcontext.h"
+#include "sysdep/stub.h"
+#include "os.h"
+#include "proc_mm.h"
+#include "skas_ptrace.h"
+#include "chan_user.h"
+#include "registers.h"
+#include "mem.h"
+#include "uml-config.h"
+#include "process.h"
+#include "longjmp.h"
+
+int is_skas_winch(int pid, int fd, void *data)
+{
+	if(pid != os_getpgrp())
+		return(0);
+
+	register_winch_irq(-1, fd, -1, data);
+	return(1);
+}
+
+void wait_stub_done(int pid, int sig, char * fname)
+{
+	int n, status, err;
+
+	do {
+		if ( sig != -1 ) {
+			err = ptrace(PTRACE_CONT, pid, 0, sig);
+			if(err)
+				panic("%s : continue failed, errno = %d\n",
+				      fname, errno);
+		}
+		sig = 0;
+
+		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
+	} while((n >= 0) && WIFSTOPPED(status) &&
+	        ((WSTOPSIG(status) == SIGVTALRM) ||
+		 /* running UML inside a detached screen can cause
+		  * SIGWINCHes
+		  */
+		 (WSTOPSIG(status) == SIGWINCH)));
+
+	if((n < 0) || !WIFSTOPPED(status) ||
+	   (WSTOPSIG(status) != SIGUSR1 && WSTOPSIG(status) != SIGTRAP)){
+		unsigned long regs[HOST_FRAME_SIZE];
+
+		if(ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
+			printk("Failed to get registers from stub, "
+			       "errno = %d\n", errno);
+		else {
+			int i;
+
+			printk("Stub registers -\n");
+			for(i = 0; i < HOST_FRAME_SIZE; i++)
+				printk("\t%d - %lx\n", i, regs[i]);
+		}
+		panic("%s : failed to wait for SIGUSR1/SIGTRAP, "
+		      "pid = %d, n = %d, errno = %d, status = 0x%x\n",
+		      fname, pid, n, errno, status);
+	}
+}
+
+extern unsigned long current_stub_stack(void);
+
+void get_skas_faultinfo(int pid, struct faultinfo * fi)
+{
+	int err;
+
+	if(ptrace_faultinfo){
+		err = ptrace(PTRACE_FAULTINFO, pid, 0, fi);
+		if(err)
+			panic("get_skas_faultinfo - PTRACE_FAULTINFO failed, "
+			      "errno = %d\n", errno);
+
+		/* Special handling for i386, which has different structs */
+		if (sizeof(struct ptrace_faultinfo) < sizeof(struct faultinfo))
+			memset((char *)fi + sizeof(struct ptrace_faultinfo), 0,
+			       sizeof(struct faultinfo) -
+			       sizeof(struct ptrace_faultinfo));
+	}
+	else {
+		wait_stub_done(pid, SIGSEGV, "get_skas_faultinfo");
+
+		/* faultinfo is prepared by the stub-segv-handler at start of
+		 * the stub stack page. We just have to copy it.
+		 */
+		memcpy(fi, (void *)current_stub_stack(), sizeof(*fi));
+	}
+}
+
+static void handle_segv(int pid, union uml_pt_regs * regs)
+{
+	get_skas_faultinfo(pid, &regs->skas.faultinfo);
+	segv(regs->skas.faultinfo, 0, 1, NULL);
+}
+
+/*To use the same value of using_sysemu as the caller, ask it that value (in local_using_sysemu)*/
+static void handle_trap(int pid, union uml_pt_regs *regs, int local_using_sysemu)
+{
+	int err, status;
+
+	/* Mark this as a syscall */
+	UPT_SYSCALL_NR(regs) = PT_SYSCALL_NR(regs->skas.regs);
+
+	if (!local_using_sysemu)
+	{
+		err = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET,
+			     __NR_getpid);
+		if(err < 0)
+			panic("handle_trap - nullifying syscall failed errno = %d\n",
+			      errno);
+
+		err = ptrace(PTRACE_SYSCALL, pid, 0, 0);
+		if(err < 0)
+			panic("handle_trap - continuing to end of syscall failed, "
+			      "errno = %d\n", errno);
+
+		CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
+		if((err < 0) || !WIFSTOPPED(status) ||
+		   (WSTOPSIG(status) != SIGTRAP + 0x80))
+			panic("handle_trap - failed to wait at end of syscall, "
+			      "errno = %d, status = %d\n", errno, status);
+	}
+
+	handle_syscall(regs);
+}
+
+extern int __syscall_stub_start;
+
+static int userspace_tramp(void *stack)
+{
+	void *addr;
+
+	ptrace(PTRACE_TRACEME, 0, 0, 0);
+
+	init_new_thread_signals(1);
+	enable_timer();
+
+	if(!proc_mm){
+		/* This has a pte, but it can't be mapped in with the usual
+		 * tlb_flush mechanism because this is part of that mechanism
+		 */
+		int fd;
+		__u64 offset;
+		fd = phys_mapping(to_phys(&__syscall_stub_start), &offset);
+		addr = mmap64((void *) UML_CONFIG_STUB_CODE, page_size(),
+			      PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset);
+		if(addr == MAP_FAILED){
+			printk("mapping mmap stub failed, errno = %d\n",
+			       errno);
+			exit(1);
+		}
+
+		if(stack != NULL){
+			fd = phys_mapping(to_phys(stack), &offset);
+			addr = mmap((void *) UML_CONFIG_STUB_DATA, page_size(),
+				    PROT_READ | PROT_WRITE,
+				    MAP_FIXED | MAP_SHARED, fd, offset);
+			if(addr == MAP_FAILED){
+				printk("mapping segfault stack failed, "
+				       "errno = %d\n", errno);
+				exit(1);
+			}
+		}
+	}
+	if(!ptrace_faultinfo && (stack != NULL)){
+		unsigned long v = UML_CONFIG_STUB_CODE +
+				  (unsigned long) stub_segv_handler -
+				  (unsigned long) &__syscall_stub_start;
+
+		set_sigstack((void *) UML_CONFIG_STUB_DATA, page_size());
+		set_handler(SIGSEGV, (void *) v, SA_ONSTACK,
+			    SIGIO, SIGWINCH, SIGALRM, SIGVTALRM,
+			    SIGUSR1, -1);
+	}
+
+	os_stop_process(os_getpid());
+	return(0);
+}
+
+/* Each element set once, and only accessed by a single processor anyway */
+#undef NR_CPUS
+#define NR_CPUS 1
+int userspace_pid[NR_CPUS];
+
+int start_userspace(unsigned long stub_stack)
+{
+	void *stack;
+	unsigned long sp;
+	int pid, status, n, flags;
+
+	stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
+		     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	if(stack == MAP_FAILED)
+		panic("start_userspace : mmap failed, errno = %d", errno);
+	sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
+
+	flags = CLONE_FILES | SIGCHLD;
+	if(proc_mm) flags |= CLONE_VM;
+	pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack);
+	if(pid < 0)
+		panic("start_userspace : clone failed, errno = %d", errno);
+
+	do {
+		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
+		if(n < 0)
+			panic("start_userspace : wait failed, errno = %d",
+			      errno);
+	} while(WIFSTOPPED(status) && (WSTOPSIG(status) == SIGVTALRM));
+
+	if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
+		panic("start_userspace : expected SIGSTOP, got status = %d",
+		      status);
+
+	if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL, (void *)PTRACE_O_TRACESYSGOOD) < 0)
+		panic("start_userspace : PTRACE_OLDSETOPTIONS failed, errno=%d\n",
+		      errno);
+
+	if(munmap(stack, PAGE_SIZE) < 0)
+		panic("start_userspace : munmap failed, errno = %d\n", errno);
+
+	return(pid);
+}
+
+void userspace(union uml_pt_regs *regs)
+{
+	int err, status, op, pid = userspace_pid[0];
+	int local_using_sysemu; /*To prevent races if using_sysemu changes under us.*/
+
+	while(1){
+		restore_registers(pid, regs);
+
+		/* Now we set local_using_sysemu to be used for one loop */
+		local_using_sysemu = get_using_sysemu();
+
+		op = SELECT_PTRACE_OPERATION(local_using_sysemu, singlestepping(NULL));
+
+		err = ptrace(op, pid, 0, 0);
+		if(err)
+			panic("userspace - could not resume userspace process, "
+			      "pid=%d, ptrace operation = %d, errno = %d\n",
+			      op, errno);
+
+		CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
+		if(err < 0)
+			panic("userspace - waitpid failed, errno = %d\n",
+			      errno);
+
+		regs->skas.is_user = 1;
+		save_registers(pid, regs);
+		UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */
+
+		if(WIFSTOPPED(status)){
+		  	switch(WSTOPSIG(status)){
+			case SIGSEGV:
+				if(PTRACE_FULL_FAULTINFO || !ptrace_faultinfo)
+					user_signal(SIGSEGV, regs, pid);
+				else handle_segv(pid, regs);
+				break;
+			case SIGTRAP + 0x80:
+			        handle_trap(pid, regs, local_using_sysemu);
+				break;
+			case SIGTRAP:
+				relay_signal(SIGTRAP, regs);
+				break;
+			case SIGIO:
+			case SIGVTALRM:
+			case SIGILL:
+			case SIGBUS:
+			case SIGFPE:
+			case SIGWINCH:
+				user_signal(WSTOPSIG(status), regs, pid);
+				break;
+			default:
+			        printk("userspace - child stopped with signal "
+				       "%d\n", WSTOPSIG(status));
+			}
+			pid = userspace_pid[0];
+			interrupt_end();
+
+			/* Avoid -ERESTARTSYS handling in host */
+			if(PT_SYSCALL_NR_OFFSET != PT_SYSCALL_RET_OFFSET)
+				PT_SYSCALL_NR(regs->skas.regs) = -1;
+		}
+	}
+}
+#define INIT_JMP_NEW_THREAD 0
+#define INIT_JMP_REMOVE_SIGSTACK 1
+#define INIT_JMP_CALLBACK 2
+#define INIT_JMP_HALT 3
+#define INIT_JMP_REBOOT 4
+
+int copy_context_skas0(unsigned long new_stack, int pid)
+{
+	int err;
+	unsigned long regs[MAX_REG_NR];
+	unsigned long current_stack = current_stub_stack();
+	struct stub_data *data = (struct stub_data *) current_stack;
+	struct stub_data *child_data = (struct stub_data *) new_stack;
+	__u64 new_offset;
+	int new_fd = phys_mapping(to_phys((void *)new_stack), &new_offset);
+
+	/* prepare offset and fd of child's stack as argument for parent's
+	 * and child's mmap2 calls
+	 */
+	*data = ((struct stub_data) { .offset	= MMAP_OFFSET(new_offset),
+				      .fd	= new_fd,
+				      .timer    = ((struct itimerval)
+					            { { 0, 1000000 / hz() },
+						      { 0, 1000000 / hz() }})});
+	get_safe_registers(regs);
+
+	/* Set parent's instruction pointer to start of clone-stub */
+	regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
+				(unsigned long) stub_clone_handler -
+				(unsigned long) &__syscall_stub_start;
+	regs[REGS_SP_INDEX] = UML_CONFIG_STUB_DATA + PAGE_SIZE -
+		sizeof(void *);
+#ifdef __SIGNAL_FRAMESIZE
+	regs[REGS_SP_INDEX] -= __SIGNAL_FRAMESIZE;
+#endif
+	err = ptrace_setregs(pid, regs);
+	if(err < 0)
+		panic("copy_context_skas0 : PTRACE_SETREGS failed, "
+		      "pid = %d, errno = %d\n", pid, errno);
+
+	/* set a well known return code for detection of child write failure */
+	child_data->err = 12345678;
+
+	/* Wait, until parent has finished its work: read child's pid from
+	 * parent's stack, and check, if bad result.
+	 */
+	wait_stub_done(pid, 0, "copy_context_skas0");
+
+	pid = data->err;
+	if(pid < 0)
+		panic("copy_context_skas0 - stub-parent reports error %d\n",
+		      pid);
+
+	/* Wait, until child has finished too: read child's result from
+	 * child's stack and check it.
+	 */
+	wait_stub_done(pid, -1, "copy_context_skas0");
+	if (child_data->err != UML_CONFIG_STUB_DATA)
+		panic("copy_context_skas0 - stub-child reports error %d\n",
+		      child_data->err);
+
+	if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL,
+		   (void *)PTRACE_O_TRACESYSGOOD) < 0)
+		panic("copy_context_skas0 : PTRACE_OLDSETOPTIONS failed, "
+		      "errno = %d\n", errno);
+
+	return pid;
+}
+
+/*
+ * This is used only, if stub pages are needed, while proc_mm is
+ * availabl. Opening /proc/mm creates a new mm_context, which lacks
+ * the stub-pages. Thus, we map them using /proc/mm-fd
+ */
+void map_stub_pages(int fd, unsigned long code,
+		    unsigned long data, unsigned long stack)
+{
+	struct proc_mm_op mmop;
+	int n;
+	__u64 code_offset;
+	int code_fd = phys_mapping(to_phys((void *) &__syscall_stub_start),
+				   &code_offset);
+
+	mmop = ((struct proc_mm_op) { .op        = MM_MMAP,
+				      .u         =
+				      { .mmap    =
+					{ .addr    = code,
+					  .len     = PAGE_SIZE,
+					  .prot    = PROT_EXEC,
+					  .flags   = MAP_FIXED | MAP_PRIVATE,
+					  .fd      = code_fd,
+					  .offset  = code_offset
+	} } });
+	n = os_write_file(fd, &mmop, sizeof(mmop));
+	if(n != sizeof(mmop))
+		panic("map_stub_pages : /proc/mm map for code failed, "
+		      "err = %d\n", -n);
+
+	if ( stack ) {
+		__u64 map_offset;
+		int map_fd = phys_mapping(to_phys((void *)stack), &map_offset);
+		mmop = ((struct proc_mm_op)
+				{ .op        = MM_MMAP,
+				  .u         =
+				  { .mmap    =
+				    { .addr    = data,
+				      .len     = PAGE_SIZE,
+				      .prot    = PROT_READ | PROT_WRITE,
+				      .flags   = MAP_FIXED | MAP_SHARED,
+				      .fd      = map_fd,
+				      .offset  = map_offset
+		} } });
+		n = os_write_file(fd, &mmop, sizeof(mmop));
+		if(n != sizeof(mmop))
+			panic("map_stub_pages : /proc/mm map for data failed, "
+			      "err = %d\n", -n);
+	}
+}
+
+void new_thread(void *stack, void **switch_buf_ptr, void **fork_buf_ptr,
+		void (*handler)(int))
+{
+	unsigned long flags;
+	sigjmp_buf switch_buf, fork_buf;
+	int enable;
+
+	*switch_buf_ptr = &switch_buf;
+	*fork_buf_ptr = &fork_buf;
+
+	/* Somewhat subtle - siglongjmp restores the signal mask before doing
+	 * the longjmp.  This means that when jumping from one stack to another
+	 * when the target stack has interrupts enabled, an interrupt may occur
+	 * on the source stack.  This is bad when starting up a process because
+	 * it's not supposed to get timer ticks until it has been scheduled.
+	 * So, we disable interrupts around the sigsetjmp to ensure that
+	 * they can't happen until we get back here where they are safe.
+	 */
+	flags = get_signals();
+	block_signals();
+	if(UML_SIGSETJMP(&fork_buf, enable) == 0)
+		new_thread_proc(stack, handler);
+
+	remove_sigstack();
+
+	set_signals(flags);
+}
+
+void thread_wait(void *sw, void *fb)
+{
+	sigjmp_buf buf, **switch_buf = sw, *fork_buf;
+	int enable;
+
+	*switch_buf = &buf;
+	fork_buf = fb;
+	if(UML_SIGSETJMP(&buf, enable) == 0)
+		siglongjmp(*fork_buf, INIT_JMP_REMOVE_SIGSTACK);
+}
+
+void switch_threads(void *me, void *next)
+{
+	sigjmp_buf my_buf, **me_ptr = me, *next_buf = next;
+	int enable;
+
+	*me_ptr = &my_buf;
+	if(UML_SIGSETJMP(&my_buf, enable) == 0)
+		UML_SIGLONGJMP(next_buf, 1);
+}
+
+static sigjmp_buf initial_jmpbuf;
+
+/* XXX Make these percpu */
+static void (*cb_proc)(void *arg);
+static void *cb_arg;
+static sigjmp_buf *cb_back;
+
+int start_idle_thread(void *stack, void *switch_buf_ptr, void **fork_buf_ptr)
+{
+	sigjmp_buf **switch_buf = switch_buf_ptr;
+	int n, enable;
+
+	set_handler(SIGWINCH, (__sighandler_t) sig_handler,
+		    SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGALRM,
+		    SIGVTALRM, -1);
+
+	*fork_buf_ptr = &initial_jmpbuf;
+	n = UML_SIGSETJMP(&initial_jmpbuf, enable);
+	switch(n){
+	case INIT_JMP_NEW_THREAD:
+		new_thread_proc((void *) stack, new_thread_handler);
+		break;
+	case INIT_JMP_REMOVE_SIGSTACK:
+		remove_sigstack();
+		break;
+	case INIT_JMP_CALLBACK:
+		(*cb_proc)(cb_arg);
+		UML_SIGLONGJMP(cb_back, 1);
+		break;
+	case INIT_JMP_HALT:
+		kmalloc_ok = 0;
+		return(0);
+	case INIT_JMP_REBOOT:
+		kmalloc_ok = 0;
+		return(1);
+	default:
+		panic("Bad sigsetjmp return in start_idle_thread - %d\n", n);
+	}
+	UML_SIGLONGJMP(*switch_buf, 1);
+}
+
+void initial_thread_cb_skas(void (*proc)(void *), void *arg)
+{
+	sigjmp_buf here;
+	int enable;
+
+	cb_proc = proc;
+	cb_arg = arg;
+	cb_back = &here;
+
+	block_signals();
+	if(UML_SIGSETJMP(&here, enable) == 0)
+		UML_SIGLONGJMP(&initial_jmpbuf, INIT_JMP_CALLBACK);
+	unblock_signals();
+
+	cb_proc = NULL;
+	cb_arg = NULL;
+	cb_back = NULL;
+}
+
+void halt_skas(void)
+{
+	block_signals();
+	UML_SIGLONGJMP(&initial_jmpbuf, INIT_JMP_HALT);
+}
+
+void reboot_skas(void)
+{
+	block_signals();
+	UML_SIGLONGJMP(&initial_jmpbuf, INIT_JMP_REBOOT);
+}
+
+void switch_mm_skas(struct mm_id *mm_idp)
+{
+	int err;
+
+#warning need cpu pid in switch_mm_skas
+	if(proc_mm){
+		err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0,
+			     mm_idp->u.mm_fd);
+		if(err)
+			panic("switch_mm_skas - PTRACE_SWITCH_MM failed, "
+			      "errno = %d\n", errno);
+	}
+	else userspace_pid[0] = mm_idp->u.pid;
+}
diff --git a/arch/um/kernel/skas/trap_user.c b/arch/um/os-Linux/skas/trap.c
index 9950a67..9ad5fbec 100644
--- a/arch/um/kernel/skas/trap_user.c
+++ b/arch/um/os-Linux/skas/trap.c
@@ -1,11 +1,10 @@
-/* 
+/*
  * Copyright (C) 2002 - 2003 Jeff Dike (jdike@addtoit.com)
  * Licensed under the GPL
  */
 
 #include <signal.h>
 #include <errno.h>
-#include "signal_user.h"
 #include "user_util.h"
 #include "kern_util.h"
 #include "task.h"
@@ -14,12 +13,13 @@
 #include "ptrace_user.h"
 #include "sysdep/ptrace.h"
 #include "sysdep/ptrace_user.h"
+#include "os.h"
 
 void sig_handler_common_skas(int sig, void *sc_ptr)
 {
 	struct sigcontext *sc = sc_ptr;
 	struct skas_regs *r;
-	struct signal_info *info;
+	void (*handler)(int, union uml_pt_regs *);
 	int save_errno = errno;
 	int save_user;
 
@@ -34,17 +34,22 @@ void sig_handler_common_skas(int sig, void *sc_ptr)
 	r = &TASK_REGS(get_current())->skas;
 	save_user = r->is_user;
 	r->is_user = 0;
-        if ( sig == SIGFPE || sig == SIGSEGV ||
-             sig == SIGBUS || sig == SIGILL ||
-             sig == SIGTRAP ) {
-                GET_FAULTINFO_FROM_SC(r->faultinfo, sc);
-        }
+	if ( sig == SIGFPE || sig == SIGSEGV ||
+	     sig == SIGBUS || sig == SIGILL ||
+	     sig == SIGTRAP ) {
+		GET_FAULTINFO_FROM_SC(r->faultinfo, sc);
+	}
 
 	change_sig(SIGUSR1, 1);
-	info = &sig_info[sig];
-	if(!info->is_irq) unblock_signals();
 
-	(*info->handler)(sig, (union uml_pt_regs *) r);
+	handler = sig_info[sig];
+
+	/* unblock SIGALRM, SIGVTALRM, SIGIO if sig isn't IRQ signal */
+	if (sig != SIGIO && sig != SIGWINCH &&
+	    sig != SIGVTALRM && sig != SIGALRM)
+		unblock_signals();
+
+	handler(sig, (union uml_pt_regs *) r);
 
 	errno = save_errno;
 	r->is_user = save_user;
@@ -54,25 +59,15 @@ extern int ptrace_faultinfo;
 
 void user_signal(int sig, union uml_pt_regs *regs, int pid)
 {
-	struct signal_info *info;
-        int segv = ((sig == SIGFPE) || (sig == SIGSEGV) || (sig == SIGBUS) ||
-                    (sig == SIGILL) || (sig == SIGTRAP));
+	void (*handler)(int, union uml_pt_regs *);
+	int segv = ((sig == SIGFPE) || (sig == SIGSEGV) || (sig == SIGBUS) ||
+		    (sig == SIGILL) || (sig == SIGTRAP));
 
 	if (segv)
 		get_skas_faultinfo(pid, &regs->skas.faultinfo);
-	info = &sig_info[sig];
-	(*info->handler)(sig, regs);
+
+	handler = sig_info[sig];
+	handler(sig, (union uml_pt_regs *) regs);
 
 	unblock_signals();
 }
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c
index 29a9e3f..6c5b17e 100644
--- a/arch/um/os-Linux/start_up.c
+++ b/arch/um/os-Linux/start_up.c
@@ -24,13 +24,11 @@
 #include "kern_util.h"
 #include "user.h"
 #include "signal_kern.h"
-#include "signal_user.h"
 #include "sysdep/ptrace.h"
 #include "sysdep/sigcontext.h"
 #include "irq_user.h"
 #include "ptrace_user.h"
 #include "mem_user.h"
-#include "time_user.h"
 #include "init.h"
 #include "os.h"
 #include "uml-config.h"
diff --git a/arch/um/os-Linux/time.c b/arch/um/os-Linux/time.c
index cf30a39..6f76267 100644
--- a/arch/um/os-Linux/time.c
+++ b/arch/um/os-Linux/time.c
@@ -1,21 +1,128 @@
+/*
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
+#include <time.h>
 #include <sys/time.h>
+#include <signal.h>
+#include <errno.h>
+#include "user_util.h"
+#include "kern_util.h"
+#include "user.h"
+#include "process.h"
+#include "kern_constants.h"
+#include "os.h"
+
+/* XXX This really needs to be declared and initialized in a kernel file since
+ * it's in <linux/time.h>
+ */
+extern struct timespec wall_to_monotonic;
+
+static void set_interval(int timer_type)
+{
+	int usec = 1000000/hz();
+	struct itimerval interval = ((struct itimerval) { { 0, usec },
+							  { 0, usec } });
+
+	if(setitimer(timer_type, &interval, NULL) == -1)
+		panic("setitimer failed - errno = %d\n", errno);
+}
+
+void enable_timer(void)
+{
+	set_interval(ITIMER_VIRTUAL);
+}
+
+void disable_timer(void)
+{
+	struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
+	if((setitimer(ITIMER_VIRTUAL, &disable, NULL) < 0) ||
+	   (setitimer(ITIMER_REAL, &disable, NULL) < 0))
+		printk("disnable_timer - setitimer failed, errno = %d\n",
+		       errno);
+	/* If there are signals already queued, after unblocking ignore them */
+	set_handler(SIGALRM, SIG_IGN, 0, -1);
+	set_handler(SIGVTALRM, SIG_IGN, 0, -1);
+}
+
+void switch_timers(int to_real)
+{
+	struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
+	struct itimerval enable = ((struct itimerval) { { 0, 1000000/hz() },
+							{ 0, 1000000/hz() }});
+	int old, new;
+
+	if(to_real){
+		old = ITIMER_VIRTUAL;
+		new = ITIMER_REAL;
+	}
+	else {
+		old = ITIMER_REAL;
+		new = ITIMER_VIRTUAL;
+	}
+
+	if((setitimer(old, &disable, NULL) < 0) ||
+	   (setitimer(new, &enable, NULL)))
+		printk("switch_timers - setitimer failed, errno = %d\n",
+		       errno);
+}
 
-unsigned long long os_usecs(void)
+void uml_idle_timer(void)
+{
+	if(signal(SIGVTALRM, SIG_IGN) == SIG_ERR)
+		panic("Couldn't unset SIGVTALRM handler");
+
+	set_handler(SIGALRM, (__sighandler_t) alarm_handler,
+		    SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
+	set_interval(ITIMER_REAL);
+}
+
+extern void ktime_get_ts(struct timespec *ts);
+#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
+
+void time_init(void)
+{
+	struct timespec now;
+
+	if(signal(SIGVTALRM, boot_timer_handler) == SIG_ERR)
+		panic("Couldn't set SIGVTALRM handler");
+	set_interval(ITIMER_VIRTUAL);
+
+	do_posix_clock_monotonic_gettime(&now);
+	wall_to_monotonic.tv_sec = -now.tv_sec;
+	wall_to_monotonic.tv_nsec = -now.tv_nsec;
+}
+
+unsigned long long os_nsecs(void)
 {
 	struct timeval tv;
 
 	gettimeofday(&tv, NULL);
-	return((unsigned long long) tv.tv_sec * 1000000 + tv.tv_usec);
+	return((unsigned long long) tv.tv_sec * BILLION + tv.tv_usec * 1000);
 }
 
-/*
- * 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:
- */
+void idle_sleep(int secs)
+{
+	struct timespec ts;
+
+	ts.tv_sec = secs;
+	ts.tv_nsec = 0;
+	nanosleep(&ts, NULL);
+}
+
+/* XXX This partly duplicates init_irq_signals */
+
+void user_time_init(void)
+{
+	set_handler(SIGVTALRM, (__sighandler_t) alarm_handler,
+		    SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH,
+		    SIGALRM, SIGUSR2, -1);
+	set_handler(SIGALRM, (__sighandler_t) alarm_handler,
+		    SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH,
+		    SIGVTALRM, SIGUSR2, -1);
+	set_interval(ITIMER_VIRTUAL);
+}
diff --git a/arch/um/os-Linux/trap.c b/arch/um/os-Linux/trap.c
new file mode 100644
index 0000000..a9f6b26
--- /dev/null
+++ b/arch/um/os-Linux/trap.c
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include <stdlib.h>
+#include <signal.h>
+#include <setjmp.h>
+#include "kern_util.h"
+#include "user_util.h"
+#include "os.h"
+#include "mode.h"
+#include "longjmp.h"
+
+void usr2_handler(int sig, union uml_pt_regs *regs)
+{
+	CHOOSE_MODE(syscall_handler_tt(sig, regs), (void) 0);
+}
+
+void (*sig_info[NSIG])(int, union uml_pt_regs *);
+
+void os_fill_handlinfo(struct kern_handlers h)
+{
+	sig_info[SIGTRAP] = h.relay_signal;
+	sig_info[SIGFPE] = h.relay_signal;
+	sig_info[SIGILL] = h.relay_signal;
+	sig_info[SIGWINCH] = h.winch;
+	sig_info[SIGBUS] = h.bus_handler;
+	sig_info[SIGSEGV] = h.page_fault;
+	sig_info[SIGIO] = h.sigio_handler;
+	sig_info[SIGVTALRM] = h.timer_handler;
+	sig_info[SIGALRM] = h.timer_handler;
+	sig_info[SIGUSR2] = usr2_handler;
+}
+
+void do_longjmp(void *b, int val)
+{
+	sigjmp_buf *buf = b;
+
+	UML_SIGLONGJMP(buf, val);
+}
diff --git a/arch/um/os-Linux/tt.c b/arch/um/os-Linux/tt.c
index a6db887..919d19f 100644
--- a/arch/um/os-Linux/tt.c
+++ b/arch/um/os-Linux/tt.c
@@ -23,12 +23,10 @@
 #include "kern_util.h"
 #include "user.h"
 #include "signal_kern.h"
-#include "signal_user.h"
 #include "sysdep/ptrace.h"
 #include "sysdep/sigcontext.h"
 #include "irq_user.h"
 #include "ptrace_user.h"
-#include "time_user.h"
 #include "init.h"
 #include "os.h"
 #include "uml-config.h"
@@ -50,6 +48,68 @@ int protect_memory(unsigned long addr, unsigned long len, int r, int w, int x,
 	return(0);
 }
 
+void kill_child_dead(int pid)
+{
+	kill(pid, SIGKILL);
+	kill(pid, SIGCONT);
+	do {
+		int n;
+		CATCH_EINTR(n = waitpid(pid, NULL, 0));
+		if (n > 0)
+			kill(pid, SIGCONT);
+		else
+			break;
+	} while(1);
+}
+
+void stop(void)
+{
+	while(1) sleep(1000000);
+}
+
+int wait_for_stop(int pid, int sig, int cont_type, void *relay)
+{
+	sigset_t *relay_signals = relay;
+	int status, ret;
+
+	while(1){
+		CATCH_EINTR(ret = waitpid(pid, &status, WUNTRACED));
+		if((ret < 0) ||
+		   !WIFSTOPPED(status) || (WSTOPSIG(status) != sig)){
+			if(ret < 0){
+				printk("wait failed, errno = %d\n",
+				       errno);
+			}
+			else if(WIFEXITED(status))
+				printk("process %d exited with status %d\n",
+				       pid, WEXITSTATUS(status));
+			else if(WIFSIGNALED(status))
+				printk("process %d exited with signal %d\n",
+				       pid, WTERMSIG(status));
+			else if((WSTOPSIG(status) == SIGVTALRM) ||
+				(WSTOPSIG(status) == SIGALRM) ||
+				(WSTOPSIG(status) == SIGIO) ||
+				(WSTOPSIG(status) == SIGPROF) ||
+				(WSTOPSIG(status) == SIGCHLD) ||
+				(WSTOPSIG(status) == SIGWINCH) ||
+				(WSTOPSIG(status) == SIGINT)){
+				ptrace(cont_type, pid, 0, WSTOPSIG(status));
+				continue;
+			}
+			else if((relay_signals != NULL) &&
+				sigismember(relay_signals, WSTOPSIG(status))){
+				ptrace(cont_type, pid, 0, WSTOPSIG(status));
+				continue;
+			}
+			else printk("process %d stopped with signal %d\n",
+				    pid, WSTOPSIG(status));
+			panic("wait_for_stop failed to wait for %d to stop "
+			      "with %d\n", pid, sig);
+		}
+		return(status);
+	}
+}
+
 /*
  *-------------------------
  * only for tt mode (will be deleted in future...)
diff --git a/arch/um/os-Linux/uaccess.c b/arch/um/os-Linux/uaccess.c
index 38d7101..166fb66 100644
--- a/arch/um/os-Linux/uaccess.c
+++ b/arch/um/os-Linux/uaccess.c
@@ -6,6 +6,7 @@
 
 #include <setjmp.h>
 #include <string.h>
+#include "longjmp.h"
 
 unsigned long __do_user_copy(void *to, const void *from, int n,
 			     void **fault_addr, void **fault_catcher,
@@ -13,10 +14,11 @@ unsigned long __do_user_copy(void *to, const void *from, int n,
 					int n), int *faulted_out)
 {
 	unsigned long *faddrp = (unsigned long *) fault_addr, ret;
+	int enable;
 
 	sigjmp_buf jbuf;
 	*fault_catcher = &jbuf;
-	if(sigsetjmp(jbuf, 1) == 0){
+	if(UML_SIGSETJMP(&jbuf, enable) == 0){
 		(*op)(to, from, n);
 		ret = 0;
 		*faulted_out = 0;
diff --git a/arch/um/kernel/user_util.c b/arch/um/os-Linux/util.c
index 4c23116..e32065e 100644
--- a/arch/um/kernel/user_util.c
+++ b/arch/um/os-Linux/util.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -29,17 +29,14 @@
 #include "init.h"
 #include "ptrace_user.h"
 #include "uml-config.h"
-
-void stop(void)
-{
-	while(1) sleep(1000000);
-}
+#include "os.h"
+#include "longjmp.h"
 
 void stack_protections(unsigned long address)
 {
 	int prot = PROT_READ | PROT_WRITE | PROT_EXEC;
 
-        if(mprotect((void *) address, page_size(), prot) < 0)
+	if(mprotect((void *) address, page_size(), prot) < 0)
 		panic("protecting stack failed, errno = %d", errno);
 }
 
@@ -59,49 +56,6 @@ void task_protections(unsigned long address)
 		panic("protecting stack failed, errno = %d", errno);
 }
 
-int wait_for_stop(int pid, int sig, int cont_type, void *relay)
-{
-	sigset_t *relay_signals = relay;
-	int status, ret;
-
-	while(1){
-		CATCH_EINTR(ret = waitpid(pid, &status, WUNTRACED));
-		if((ret < 0) ||
-		   !WIFSTOPPED(status) || (WSTOPSIG(status) != sig)){
-			if(ret < 0){
-				printk("wait failed, errno = %d\n",
-				       errno);
-			}
-			else if(WIFEXITED(status)) 
-				printk("process %d exited with status %d\n",
-				       pid, WEXITSTATUS(status));
-			else if(WIFSIGNALED(status))
-				printk("process %d exited with signal %d\n",
-				       pid, WTERMSIG(status));
-			else if((WSTOPSIG(status) == SIGVTALRM) ||
-				(WSTOPSIG(status) == SIGALRM) ||
-				(WSTOPSIG(status) == SIGIO) ||
-				(WSTOPSIG(status) == SIGPROF) ||
-				(WSTOPSIG(status) == SIGCHLD) ||
-				(WSTOPSIG(status) == SIGWINCH) ||
-				(WSTOPSIG(status) == SIGINT)){
-				ptrace(cont_type, pid, 0, WSTOPSIG(status));
-				continue;
-			}
-			else if((relay_signals != NULL) &&
-				sigismember(relay_signals, WSTOPSIG(status))){
-				ptrace(cont_type, pid, 0, WSTOPSIG(status));
-				continue;
-			}
-			else printk("process %d stopped with signal %d\n",
-				    pid, WSTOPSIG(status));
-			panic("wait_for_stop failed to wait for %d to stop "
-			      "with %d\n", pid, sig);
-		}
-		return(status);
-	}
-}
-
 int raw(int fd)
 {
 	struct termios tt;
@@ -113,7 +67,7 @@ int raw(int fd)
 
 	cfmakeraw(&tt);
 
- 	CATCH_EINTR(err = tcsetattr(fd, TCSADRAIN, &tt));
+	CATCH_EINTR(err = tcsetattr(fd, TCSADRAIN, &tt));
 	if(err < 0)
 		return -errno;
 
@@ -149,7 +103,7 @@ void setup_hostinfo(void)
 
 int setjmp_wrapper(void (*proc)(void *, void *), ...)
 {
-        va_list args;
+	va_list args;
 	sigjmp_buf buf;
 	int n;
 
@@ -161,14 +115,3 @@ int setjmp_wrapper(void (*proc)(void *, void *), ...)
 	va_end(args);
 	return(n);
 }
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/sys-i386/ldt.c b/arch/um/sys-i386/ldt.c
index 17746b4..0cdfd44 100644
--- a/arch/um/sys-i386/ldt.c
+++ b/arch/um/sys-i386/ldt.c
@@ -16,6 +16,8 @@
 #include "choose-mode.h"
 #include "kern.h"
 #include "mode_kern.h"
+#include "proc_mm.h"
+#include "os.h"
 
 extern int modify_ldt(int func, void *ptr, unsigned long bytecount);
 
@@ -456,13 +458,14 @@ long init_new_ldt(struct mmu_context_skas * new_mm,
 	int i;
 	long page, err=0;
 	void *addr = NULL;
+	struct proc_mm_op copy;
 
-	memset(&desc, 0, sizeof(desc));
 
 	if(!ptrace_ldt)
 		init_MUTEX(&new_mm->ldt.semaphore);
 
 	if(!from_mm){
+		memset(&desc, 0, sizeof(desc));
 		/*
 		 * We have to initialize a clean ldt.
 		 */
@@ -494,8 +497,26 @@ long init_new_ldt(struct mmu_context_skas * new_mm,
 			}
 		}
 		new_mm->ldt.entry_count = 0;
+
+		goto out;
 	}
-	else if (!ptrace_ldt) {
+
+	if(proc_mm){
+		/* We have a valid from_mm, so we now have to copy the LDT of
+		 * from_mm to new_mm, because using proc_mm an new mm with
+		 * an empty/default LDT was created in new_mm()
+		 */
+		copy = ((struct proc_mm_op) { .op 	= MM_COPY_SEGMENTS,
+					      .u 	=
+					      { .copy_segments =
+							from_mm->id.u.mm_fd } } );
+		i = os_write_file(new_mm->id.u.mm_fd, &copy, sizeof(copy));
+		if(i != sizeof(copy))
+			printk("new_mm : /proc/mm copy_segments failed, "
+			       "err = %d\n", -i);
+	}
+
+	if(!ptrace_ldt) {
 		/* Our local LDT is used to supply the data for
 		 * modify_ldt(READLDT), if PTRACE_LDT isn't available,
 		 * i.e., we have to use the stub for modify_ldt, which
@@ -524,6 +545,7 @@ long init_new_ldt(struct mmu_context_skas * new_mm,
 		up(&from_mm->ldt.semaphore);
 	}
 
+    out:
 	return err;
 }
 
diff --git a/arch/um/sys-i386/signal.c b/arch/um/sys-i386/signal.c
index 16bc1992..7cd1a82 100644
--- a/arch/um/sys-i386/signal.c
+++ b/arch/um/sys-i386/signal.c
@@ -10,7 +10,6 @@
 #include "asm/uaccess.h"
 #include "asm/unistd.h"
 #include "frame_kern.h"
-#include "signal_user.h"
 #include "sigcontext.h"
 #include "registers.h"
 #include "mode.h"