Merge branch 'master'

64 files changed, 950 insertions, 1076 deletions

diff --git a/arch/um/Makefile b/arch/um/Makefile
index 5b5af95721a..e1ffad22460 100644
--- a/arch/um/Makefile
+++ b/arch/um/Makefile
@@ -28,8 +28,6 @@ SYMLINK_HEADERS := $(foreach header,$(SYMLINK_HEADERS),include/asm-um/$(header))
 ARCH_SYMLINKS = include/asm-um/arch $(ARCH_DIR)/include/sysdep $(ARCH_DIR)/os \
 	$(SYMLINK_HEADERS) $(ARCH_DIR)/include/uml-config.h
 
-GEN_HEADERS += $(ARCH_DIR)/include/task.h $(ARCH_DIR)/include/kern_constants.h
-
 um-modes-$(CONFIG_MODE_TT) += tt
 um-modes-$(CONFIG_MODE_SKAS) += skas
 
@@ -45,9 +43,7 @@ endif
 
 ARCH_INCLUDE	:= -I$(ARCH_DIR)/include
 ifneq ($(KBUILD_SRC),)
-ARCH_INCLUDE	+= -I$(ARCH_DIR)/include2
 ARCH_INCLUDE	+= -I$(srctree)/$(ARCH_DIR)/include
-MRPROPER_DIRS	+= $(ARCH_DIR)/include2
 endif
 SYS_DIR		:= $(ARCH_DIR)/include/sysdep-$(SUBARCH)
 
@@ -87,10 +83,6 @@ CONFIG_KERNEL_HALF_GIGS ?= 0
 
 SIZE = (($(CONFIG_NEST_LEVEL) + $(CONFIG_KERNEL_HALF_GIGS)) * 0x20000000)
 
-ifeq ($(CONFIG_MODE_SKAS), y)
-$(SYS_HEADERS) : $(ARCH_DIR)/include/skas_ptregs.h
-endif
-
 .PHONY: linux
 
 all: linux
@@ -111,7 +103,8 @@ else
 $(shell cd $(ARCH_DIR) && ln -sf Kconfig.$(SUBARCH) Kconfig.arch)
 endif
 
-archprepare: $(ARCH_SYMLINKS) $(SYS_HEADERS) $(GEN_HEADERS)
+archprepare: $(ARCH_SYMLINKS) $(ARCH_DIR)/include/user_constants.h
+prepare: $(ARCH_DIR)/include/kern_constants.h
 
 LINK-$(CONFIG_LD_SCRIPT_STATIC) += -static
 LINK-$(CONFIG_LD_SCRIPT_DYN) += -Wl,-rpath,/lib
@@ -146,22 +139,20 @@ endef
 #When cleaning we don't include .config, so we don't include
 #TT or skas makefiles and don't clean skas_ptregs.h.
 CLEAN_FILES += linux x.i gmon.out $(ARCH_DIR)/include/uml-config.h \
-	$(GEN_HEADERS) $(ARCH_DIR)/include/skas_ptregs.h \
-	$(ARCH_DIR)/include/user_constants.h $(ARCH_DIR)/Kconfig.arch
+	$(ARCH_DIR)/include/user_constants.h \
+	$(ARCH_DIR)/include/kern_constants.h $(ARCH_DIR)/Kconfig.arch
 
 MRPROPER_FILES += $(SYMLINK_HEADERS) $(ARCH_SYMLINKS) \
 	$(addprefix $(ARCH_DIR)/kernel/,$(KERN_SYMLINKS)) $(ARCH_DIR)/os
 
 archclean:
-	$(Q)$(MAKE) $(clean)=$(ARCH_DIR)/util
-	$(Q)$(MAKE) $(clean)=$(ARCH_DIR)/os-$(OS)/util
 	@find . \( -name '*.bb' -o -name '*.bbg' -o -name '*.da' \
 		-o -name '*.gcov' \) -type f -print | xargs rm -f
 
 $(SYMLINK_HEADERS):
 	@echo '  SYMLINK $@'
 ifneq ($(KBUILD_SRC),)
-	ln -fsn $(srctree)/include/asm-um/$(basename $(notdir $@))-$(SUBARCH)$(suffix $@) $@
+	$(Q)ln -fsn $(srctree)/include/asm-um/$(basename $(notdir $@))-$(SUBARCH)$(suffix $@) $@
 else
 	$(Q)cd $(TOPDIR)/$(dir $@) ; \
 	ln -sf $(basename $(notdir $@))-$(SUBARCH)$(suffix $@) $(notdir $@)
@@ -180,9 +171,7 @@ $(ARCH_DIR)/include/sysdep:
 	@echo '  SYMLINK $@'
 ifneq ($(KBUILD_SRC),)
 	$(Q)mkdir -p $(ARCH_DIR)/include
-	$(Q)mkdir -p $(ARCH_DIR)/include2
-	$(Q)ln -fsn sysdep-$(SUBARCH) $(ARCH_DIR)/include/sysdep
-	$(Q)ln -fsn $(srctree)/$(ARCH_DIR)/include/sysdep-$(SUBARCH) $(ARCH_DIR)/include2/sysdep
+	$(Q)ln -fsn $(srctree)/$(ARCH_DIR)/include/sysdep-$(SUBARCH) $(ARCH_DIR)/include/sysdep
 else
 	$(Q)cd $(ARCH_DIR)/include && ln -sf sysdep-$(SUBARCH) sysdep
 endif
@@ -202,8 +191,6 @@ endef
 
 define filechk_gen-asm-offsets
         (set -e; \
-         echo "#ifndef __ASM_OFFSETS_H__"; \
-         echo "#define __ASM_OFFSETS_H__"; \
          echo "/*"; \
          echo " * DO NOT MODIFY."; \
          echo " *"; \
@@ -212,8 +199,7 @@ define filechk_gen-asm-offsets
          echo " */"; \
          echo ""; \
          sed -ne "/^->/{s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; s:->::; p;}"; \
-         echo ""; \
-         echo "#endif" )
+         echo ""; )
 endef
 
 $(ARCH_DIR)/include/uml-config.h : include/linux/autoconf.h
@@ -222,50 +208,18 @@ $(ARCH_DIR)/include/uml-config.h : include/linux/autoconf.h
 $(ARCH_DIR)/user-offsets.s: $(ARCH_DIR)/sys-$(SUBARCH)/user-offsets.c
 	$(CC) $(USER_CFLAGS) -S -o $@ $<
 
-$(ARCH_DIR)/user-offsets.h: $(ARCH_DIR)/user-offsets.s
+$(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)/user-offsets.h
+CLEAN_FILES += $(ARCH_DIR)/user-offsets.s
 
 $(ARCH_DIR)/kernel-offsets.s: $(ARCH_DIR)/sys-$(SUBARCH)/kernel-offsets.c \
-				   $(ARCH_SYMLINKS) \
-				   $(SYS_DIR)/sc.h \
-				   include/asm include/linux/version.h \
-				   include/config/MARKER \
-				   $(ARCH_DIR)/include/user_constants.h
+				   archprepare
 	$(CC) $(CFLAGS) $(NOSTDINC_FLAGS) $(CPPFLAGS) -S -o $@ $<
 
-$(ARCH_DIR)/kernel-offsets.h: $(ARCH_DIR)/kernel-offsets.s
+$(ARCH_DIR)/include/kern_constants.h: $(ARCH_DIR)/kernel-offsets.s
 	$(call filechk,gen-asm-offsets)
 
-CLEAN_FILES += $(ARCH_DIR)/kernel-offsets.s  $(ARCH_DIR)/kernel-offsets.h
-
-$(ARCH_DIR)/include/task.h: $(ARCH_DIR)/util/mk_task
-	$(call filechk,gen_header)
-
-$(ARCH_DIR)/include/user_constants.h: $(ARCH_DIR)/os-$(OS)/util/mk_user_constants
-	$(call filechk,gen_header)
-
-$(ARCH_DIR)/include/kern_constants.h: $(ARCH_DIR)/util/mk_constants
-	$(call filechk,gen_header)
-
-$(ARCH_DIR)/include/skas_ptregs.h: $(ARCH_DIR)/kernel/skas/util/mk_ptregs
-	$(call filechk,gen_header)
-
-$(ARCH_DIR)/os-$(OS)/util/mk_user_constants: $(ARCH_DIR)/os-$(OS)/util FORCE ;
-
-$(ARCH_DIR)/util/mk_task $(ARCH_DIR)/util/mk_constants: $(ARCH_DIR)/include/user_constants.h $(ARCH_DIR)/util \
-	FORCE ;
-
-$(ARCH_DIR)/kernel/skas/util/mk_ptregs: $(ARCH_DIR)/kernel/skas/util FORCE ;
-
-$(ARCH_DIR)/util: scripts_basic $(SYS_DIR)/sc.h $(ARCH_DIR)/kernel-offsets.h FORCE
-	$(Q)$(MAKE) $(build)=$@
-
-$(ARCH_DIR)/kernel/skas/util: scripts_basic $(ARCH_DIR)/user-offsets.h FORCE
-	$(Q)$(MAKE) $(build)=$@
-
-$(ARCH_DIR)/os-$(OS)/util: scripts_basic $(ARCH_DIR)/user-offsets.h FORCE
-	$(Q)$(MAKE) $(build)=$@
+CLEAN_FILES += $(ARCH_DIR)/kernel-offsets.s
 
 export SUBARCH USER_CFLAGS OS
diff --git a/arch/um/Makefile-i386 b/arch/um/Makefile-i386
index 1ab431a53ac..2ee8a285811 100644
--- a/arch/um/Makefile-i386
+++ b/arch/um/Makefile-i386
@@ -32,25 +32,3 @@ CFLAGS += -U__$(SUBARCH)__ -U$(SUBARCH)
 ifneq ($(CONFIG_GPROF),y)
 ARCH_CFLAGS += -DUM_FASTCALL
 endif
-
-SYS_UTIL_DIR	:= $(ARCH_DIR)/sys-i386/util
-SYS_HEADERS	:= $(SYS_DIR)/sc.h $(SYS_DIR)/thread.h
-
-prepare: $(SYS_HEADERS)
-
-$(SYS_DIR)/sc.h: $(SYS_UTIL_DIR)/mk_sc
-	$(call filechk,gen_header)
-
-$(SYS_DIR)/thread.h: $(SYS_UTIL_DIR)/mk_thread 
-	$(call filechk,gen_header)
-
-$(SYS_UTIL_DIR)/mk_sc: scripts_basic $(ARCH_DIR)/user-offsets.h FORCE
-	$(Q)$(MAKE) $(build)=$(SYS_UTIL_DIR) $@
-
-$(SYS_UTIL_DIR)/mk_thread: scripts_basic $(ARCH_DIR)/kernel-offsets.h FORCE
-	$(Q)$(MAKE) $(build)=$(SYS_UTIL_DIR) $@
-
-$(SYS_UTIL_DIR): scripts_basic include/asm FORCE
-	$(Q)$(MAKE) $(build)=$(SYS_UTIL_DIR)
-
-CLEAN_FILES += $(SYS_HEADERS)
diff --git a/arch/um/Makefile-skas b/arch/um/Makefile-skas
index fd18ec57227..ac35de5316a 100644
--- a/arch/um/Makefile-skas
+++ b/arch/um/Makefile-skas
@@ -10,5 +10,3 @@ CFLAGS-$(CONFIG_GCOV) += $(GCOV_OPT)
 CFLAGS-$(CONFIG_GPROF) += $(GPROF_OPT)
 LINK-$(CONFIG_GCOV) += $(GCOV_OPT)
 LINK-$(CONFIG_GPROF) += $(GPROF_OPT)
-
-GEN_HEADERS += $(ARCH_DIR)/include/skas_ptregs.h
diff --git a/arch/um/Makefile-x86_64 b/arch/um/Makefile-x86_64
index 436abbba409..4f118d5cc2e 100644
--- a/arch/um/Makefile-x86_64
+++ b/arch/um/Makefile-x86_64
@@ -12,24 +12,3 @@ CHECKFLAGS  += -m64
 
 ELF_ARCH := i386:x86-64
 ELF_FORMAT := elf64-x86-64
-
-SYS_UTIL_DIR := $(ARCH_DIR)/sys-x86_64/util
-SYS_DIR := $(ARCH_DIR)/include/sysdep-x86_64
-
-SYS_HEADERS = $(SYS_DIR)/sc.h $(SYS_DIR)/thread.h
-
-prepare: $(SYS_HEADERS)
-
-$(SYS_DIR)/sc.h: $(SYS_UTIL_DIR)/mk_sc
-	$(call filechk,gen_header)
-
-$(SYS_DIR)/thread.h: $(SYS_UTIL_DIR)/mk_thread
-	$(call filechk,gen_header)
-
-$(SYS_UTIL_DIR)/mk_sc: scripts_basic $(ARCH_DIR)/user-offsets.h FORCE
-	$(Q)$(MAKE) $(build)=$(SYS_UTIL_DIR) $@
-
-$(SYS_UTIL_DIR)/mk_thread: scripts_basic $(GEN_HEADERS) $(ARCH_DIR)/kernel-offsets.h FORCE
-	$(Q)$(MAKE) $(build)=$(SYS_UTIL_DIR) $@
-
-CLEAN_FILES += $(SYS_HEADERS)
diff --git a/arch/um/drivers/Makefile b/arch/um/drivers/Makefile
index 783e18cae09..de17d4c6e02 100644
--- a/arch/um/drivers/Makefile
+++ b/arch/um/drivers/Makefile
@@ -13,7 +13,7 @@ mcast-objs := mcast_kern.o mcast_user.o
 net-objs := net_kern.o net_user.o
 mconsole-objs := mconsole_kern.o mconsole_user.o
 hostaudio-objs := hostaudio_kern.o
-ubd-objs := ubd_kern.o
+ubd-objs := ubd_kern.o ubd_user.o
 port-objs := port_kern.o port_user.o
 harddog-objs := harddog_kern.o harddog_user.o
 
diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index 14a12d6b3df..16e7dc89f61 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -19,18 +19,44 @@
 #include "line.h"
 #include "os.h"
 
-#ifdef CONFIG_NOCONFIG_CHAN
+/* XXX: could well be moved to somewhere else, if needed. */
+static int my_printf(const char * fmt, ...)
+	__attribute__ ((format (printf, 1, 2)));
+
+static int my_printf(const char * fmt, ...)
+{
+	/* Yes, can be called on atomic context.*/
+	char *buf = kmalloc(4096, GFP_ATOMIC);
+	va_list args;
+	int r;
+
+	if (!buf) {
+		/* We print directly fmt.
+		 * Yes, yes, yes, feel free to complain. */
+		r = strlen(fmt);
+	} else {
+		va_start(args, fmt);
+		r = vsprintf(buf, fmt, args);
+		va_end(args);
+		fmt = buf;
+	}
 
-/* The printk's here are wrong because we are complaining that there is no
- * output device, but printk is printing to that output device.  The user will
- * never see the error.  printf would be better, except it can't run on a
- * kernel stack because it will overflow it.
- * Use printk for now since that will avoid crashing.
- */
+	if (r)
+		r = os_write_file(1, fmt, r);
+	return r;
+
+}
+
+#ifdef CONFIG_NOCONFIG_CHAN
+/* Despite its name, there's no added trailing newline. */
+static int my_puts(const char * buf)
+{
+	return os_write_file(1, buf, strlen(buf));
+}
 
 static void *not_configged_init(char *str, int device, struct chan_opts *opts)
 {
-	printk(KERN_ERR "Using a channel type which is configured out of "
+	my_puts("Using a channel type which is configured out of "
 	       "UML\n");
 	return(NULL);
 }
@@ -38,27 +64,27 @@ static void *not_configged_init(char *str, int device, struct chan_opts *opts)
 static int not_configged_open(int input, int output, int primary, void *data,
 			      char **dev_out)
 {
-	printk(KERN_ERR "Using a channel type which is configured out of "
+	my_puts("Using a channel type which is configured out of "
 	       "UML\n");
 	return(-ENODEV);
 }
 
 static void not_configged_close(int fd, void *data)
 {
-	printk(KERN_ERR "Using a channel type which is configured out of "
+	my_puts("Using a channel type which is configured out of "
 	       "UML\n");
 }
 
 static int not_configged_read(int fd, char *c_out, void *data)
 {
-	printk(KERN_ERR "Using a channel type which is configured out of "
+	my_puts("Using a channel type which is configured out of "
 	       "UML\n");
 	return(-EIO);
 }
 
 static int not_configged_write(int fd, const char *buf, int len, void *data)
 {
-	printk(KERN_ERR "Using a channel type which is configured out of "
+	my_puts("Using a channel type which is configured out of "
 	       "UML\n");
 	return(-EIO);
 }
@@ -66,7 +92,7 @@ static int not_configged_write(int fd, const char *buf, int len, void *data)
 static int not_configged_console_write(int fd, const char *buf, int len,
 				       void *data)
 {
-	printk(KERN_ERR "Using a channel type which is configured out of "
+	my_puts("Using a channel type which is configured out of "
 	       "UML\n");
 	return(-EIO);
 }
@@ -74,14 +100,14 @@ static int not_configged_console_write(int fd, const char *buf, int len,
 static int not_configged_window_size(int fd, void *data, unsigned short *rows,
 				     unsigned short *cols)
 {
-	printk(KERN_ERR "Using a channel type which is configured out of "
+	my_puts("Using a channel type which is configured out of "
 	       "UML\n");
 	return(-ENODEV);
 }
 
 static void not_configged_free(void *data)
 {
-	printf(KERN_ERR "Using a channel type which is configured out of "
+	my_puts("Using a channel type which is configured out of "
 	       "UML\n");
 }
 
@@ -457,7 +483,7 @@ static struct chan *parse_chan(char *str, int pri, int device,
 		}
 	}
 	if(ops == NULL){
-		printk(KERN_ERR "parse_chan couldn't parse \"%s\"\n", 
+		my_printf("parse_chan couldn't parse \"%s\"\n",
 		       str);
 		return(NULL);
 	}
@@ -465,7 +491,7 @@ static struct chan *parse_chan(char *str, int pri, int device,
 	data = (*ops->init)(str, device, opts);
 	if(data == NULL) return(NULL);
 
-	chan = kmalloc(sizeof(*chan), GFP_KERNEL);
+	chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
 	if(chan == NULL) return(NULL);
 	*chan = ((struct chan) { .list	 	= LIST_HEAD_INIT(chan->list),
 				 .primary	= 1,
diff --git a/arch/um/drivers/cow.h b/arch/um/drivers/cow.h
index 4fcf3a8d13f..dc36b222100 100644
--- a/arch/um/drivers/cow.h
+++ b/arch/um/drivers/cow.h
@@ -3,15 +3,40 @@
 
 #include <asm/types.h>
 
-#if defined(__BIG_ENDIAN)
-# define ntohll(x) (x)
-# define htonll(x) (x)
-#elif defined(__LITTLE_ENDIAN)
-# define ntohll(x)  bswap_64(x)
-# define htonll(x)  bswap_64(x)
+#if defined(__KERNEL__)
+
+# include <asm/byteorder.h>
+
+# if defined(__BIG_ENDIAN)
+#	define ntohll(x) (x)
+#	define htonll(x) (x)
+# elif defined(__LITTLE_ENDIAN)
+#	define ntohll(x)  be64_to_cpu(x)
+#	define htonll(x)  cpu_to_be64(x)
+# else
+#	error "Could not determine byte order"
+# endif
+
 #else
-#error "__BYTE_ORDER not defined"
+/* For the definition of ntohl, htonl and __BYTE_ORDER */
+#include <endian.h>
+#include <netinet/in.h>
+#if defined(__BYTE_ORDER)
+
+#  if __BYTE_ORDER == __BIG_ENDIAN
+#	define ntohll(x) (x)
+#	define htonll(x) (x)
+#  elif __BYTE_ORDER == __LITTLE_ENDIAN
+#	define ntohll(x)  bswap_64(x)
+#	define htonll(x)  bswap_64(x)
+#  else
+#	error "Could not determine byte order: __BYTE_ORDER uncorrectly defined"
+#  endif
+
+#else  /* ! defined(__BYTE_ORDER) */
+#	error "Could not determine byte order: __BYTE_ORDER not defined"
 #endif
+#endif /* ! defined(__KERNEL__) */
 
 extern int init_cow_file(int fd, char *cow_file, char *backing_file,
 			 int sectorsize, int alignment, int *bitmap_offset_out,
diff --git a/arch/um/drivers/cow_user.c b/arch/um/drivers/cow_user.c
index a8ce6fc3ef2..fbe2217db5d 100644
--- a/arch/um/drivers/cow_user.c
+++ b/arch/um/drivers/cow_user.c
@@ -9,7 +9,6 @@
 #include <sys/time.h>
 #include <sys/param.h>
 #include <sys/user.h>
-#include <netinet/in.h>
 
 #include "os.h"
 
diff --git a/arch/um/drivers/port_kern.c b/arch/um/drivers/port_kern.c
index c41efd207fc..189839e4f1d 100644
--- a/arch/um/drivers/port_kern.c
+++ b/arch/um/drivers/port_kern.c
@@ -7,7 +7,6 @@
 #include "linux/sched.h"
 #include "linux/slab.h"
 #include "linux/interrupt.h"
-#include "linux/irq.h"
 #include "linux/spinlock.h"
 #include "linux/errno.h"
 #include "asm/atomic.h"
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index e77a38da435..f73134333f6 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -35,7 +35,6 @@
 #include "linux/blkpg.h"
 #include "linux/genhd.h"
 #include "linux/spinlock.h"
-#include "asm/atomic.h"
 #include "asm/segment.h"
 #include "asm/uaccess.h"
 #include "asm/irq.h"
@@ -54,21 +53,20 @@
 #include "mem.h"
 #include "mem_kern.h"
 #include "cow.h"
-#include "aio.h"
 
 enum ubd_req { UBD_READ, UBD_WRITE };
 
 struct io_thread_req {
-	enum aio_type op;
+	enum ubd_req op;
 	int fds[2];
 	unsigned long offsets[2];
 	unsigned long long offset;
 	unsigned long length;
 	char *buffer;
 	int sectorsize;
-	int bitmap_offset;
-	long bitmap_start;
-	long bitmap_end;
+	unsigned long sector_mask;
+	unsigned long long cow_offset;
+	unsigned long bitmap_words[2];
 	int error;
 };
 
@@ -82,31 +80,28 @@ extern int create_cow_file(char *cow_file, char *backing_file,
 			   unsigned long *bitmap_len_out,
 			   int *data_offset_out);
 extern int read_cow_bitmap(int fd, void *buf, int offset, int len);
-extern void do_io(struct io_thread_req *req, struct request *r,
-		  unsigned long *bitmap);
+extern void do_io(struct io_thread_req *req);
 
-static inline int ubd_test_bit(__u64 bit, void *data)
+static inline int ubd_test_bit(__u64 bit, unsigned char *data)
 {
-	unsigned char *buffer = data;
 	__u64 n;
 	int bits, off;
 
-	bits = sizeof(buffer[0]) * 8;
+	bits = sizeof(data[0]) * 8;
 	n = bit / bits;
 	off = bit % bits;
-	return((buffer[n] & (1 << off)) != 0);
+	return((data[n] & (1 << off)) != 0);
 }
 
-static inline void ubd_set_bit(__u64 bit, void *data)
+static inline void ubd_set_bit(__u64 bit, unsigned char *data)
 {
-	unsigned char *buffer = data;
 	__u64 n;
 	int bits, off;
 
-	bits = sizeof(buffer[0]) * 8;
+	bits = sizeof(data[0]) * 8;
 	n = bit / bits;
 	off = bit % bits;
-	buffer[n] |= (1 << off);
+	data[n] |= (1 << off);
 }
 /*End stuff from ubd_user.h*/
 
@@ -115,6 +110,8 @@ static inline void ubd_set_bit(__u64 bit, void *data)
 static DEFINE_SPINLOCK(ubd_io_lock);
 static DEFINE_SPINLOCK(ubd_lock);
 
+static void (*do_ubd)(void);
+
 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,
@@ -161,8 +158,6 @@ struct cow {
         int data_offset;
 };
 
-#define MAX_SG 64
-
 struct ubd {
 	char *file;
 	int count;
@@ -173,7 +168,6 @@ struct ubd {
 	int no_cow;
 	struct cow cow;
 	struct platform_device pdev;
-        struct scatterlist sg[MAX_SG];
 };
 
 #define DEFAULT_COW { \
@@ -466,114 +460,81 @@ __uml_help(fakehd,
 );
 
 static void do_ubd_request(request_queue_t * q);
-static int in_ubd;
+
+/* Only changed by ubd_init, which is an initcall. */
+int thread_fd = -1;
 
 /* Changed by ubd_handler, which is serialized because interrupts only
  * happen on CPU 0.
  */
 int intr_count = 0;
 
-static void ubd_end_request(struct request *req, int bytes, int uptodate)
+/* call ubd_finish if you need to serialize */
+static void __ubd_finish(struct request *req, int error)
 {
-	if (!end_that_request_first(req, uptodate, bytes >> 9)) {
-		add_disk_randomness(req->rq_disk);
-		end_that_request_last(req);
+	int nsect;
+
+	if(error){
+		end_request(req, 0);
+		return;
 	}
+	nsect = req->current_nr_sectors;
+	req->sector += nsect;
+	req->buffer += nsect << 9;
+	req->errors = 0;
+	req->nr_sectors -= nsect;
+	req->current_nr_sectors = 0;
+	end_request(req, 1);
 }
 
-/* call ubd_finish if you need to serialize */
-static void __ubd_finish(struct request *req, int bytes)
+static inline void ubd_finish(struct request *req, int error)
 {
-	if(bytes < 0){
-		ubd_end_request(req, 0, 0);
-  		return;
-  	}
-
-	ubd_end_request(req, bytes, 1);
+ 	spin_lock(&ubd_io_lock);
+	__ubd_finish(req, error);
+	spin_unlock(&ubd_io_lock);
 }
 
-static inline void ubd_finish(struct request *req, int bytes)
+/* Called without ubd_io_lock held */
+static void ubd_handler(void)
 {
-   	spin_lock(&ubd_io_lock);
-	__ubd_finish(req, bytes);
-  	spin_unlock(&ubd_io_lock);
+	struct io_thread_req req;
+	struct request *rq = elv_next_request(ubd_queue);
+	int n;
+
+	do_ubd = NULL;
+	intr_count++;
+	n = os_read_file(thread_fd, &req, sizeof(req));
+	if(n != sizeof(req)){
+		printk(KERN_ERR "Pid %d - spurious interrupt in ubd_handler, "
+		       "err = %d\n", os_getpid(), -n);
+		spin_lock(&ubd_io_lock);
+		end_request(rq, 0);
+		spin_unlock(&ubd_io_lock);
+		return;
+	}
+        
+	ubd_finish(rq, req.error);
+	reactivate_fd(thread_fd, UBD_IRQ);	
+	do_ubd_request(ubd_queue);
 }
 
-struct bitmap_io {
-        atomic_t count;
-        struct aio_context aio;
-};
-
-struct ubd_aio {
-        struct aio_context aio;
-        struct request *req;
-        int len;
-        struct bitmap_io *bitmap;
-        void *bitmap_buf;
-};
-
-static int ubd_reply_fd = -1;
-
 static irqreturn_t ubd_intr(int irq, void *dev, struct pt_regs *unused)
 {
-	struct aio_thread_reply reply;
-	struct ubd_aio *aio;
-	struct request *req;
-	int err, n, fd = (int) (long) dev;
-
-	while(1){
-		err = os_read_file(fd, &reply, sizeof(reply));
-		if(err == -EAGAIN)
-			break;
-		if(err < 0){
-			printk("ubd_aio_handler - read returned err %d\n",
-			       -err);
-			break;
-		}
-
-                aio = container_of(reply.data, struct ubd_aio, aio);
-                n = reply.err;
-
-		if(n == 0){
-			req = aio->req;
-			req->nr_sectors -= aio->len >> 9;
-
-			if((aio->bitmap != NULL) &&
-			   (atomic_dec_and_test(&aio->bitmap->count))){
-                                aio->aio = aio->bitmap->aio;
-                                aio->len = 0;
-                                kfree(aio->bitmap);
-                                aio->bitmap = NULL;
-                                submit_aio(&aio->aio);
-			}
-			else {
-				if((req->nr_sectors == 0) &&
-                                   (aio->bitmap == NULL)){
-					int len = req->hard_nr_sectors << 9;
-					ubd_finish(req, len);
-				}
-
-                                if(aio->bitmap_buf != NULL)
-                                        kfree(aio->bitmap_buf);
-				kfree(aio);
-			}
-		}
-                else if(n < 0){
-                        ubd_finish(aio->req, n);
-                        if(aio->bitmap != NULL)
-                                kfree(aio->bitmap);
-                        if(aio->bitmap_buf != NULL)
-                                kfree(aio->bitmap_buf);
-                        kfree(aio);
-                }
-	}
-	reactivate_fd(fd, UBD_IRQ);
+	ubd_handler();
+	return(IRQ_HANDLED);
+}
 
-        do_ubd_request(ubd_queue);
+/* Only changed by ubd_init, which is an initcall. */
+static int io_pid = -1;
 
-	return(IRQ_HANDLED);
+void kill_io_thread(void)
+{
+	if(io_pid != -1) 
+		os_kill_process(io_pid, 1);
 }
 
+__uml_exitcall(kill_io_thread);
+
 static int ubd_file_size(struct ubd *dev, __u64 *size_out)
 {
 	char *file;
@@ -608,7 +569,7 @@ static int ubd_open_dev(struct ubd *dev)
 				&dev->cow.data_offset, create_ptr);
 
 	if((dev->fd == -ENOENT) && create_cow){
-		dev->fd = create_cow_file(dev->file, dev->cow.file,
+		dev->fd = create_cow_file(dev->file, dev->cow.file, 
 					  dev->openflags, 1 << 9, PAGE_SIZE,
 					  &dev->cow.bitmap_offset, 
 					  &dev->cow.bitmap_len,
@@ -870,10 +831,6 @@ int ubd_init(void)
 {
         int i;
 
-	ubd_reply_fd = init_aio_irq(UBD_IRQ, "ubd", ubd_intr);
-	if(ubd_reply_fd < 0)
-		printk("Setting up ubd AIO failed, err = %d\n", ubd_reply_fd);
-
 	devfs_mk_dir("ubd");
 	if (register_blkdev(MAJOR_NR, "ubd"))
 		return -1;
@@ -884,7 +841,6 @@ int ubd_init(void)
 		return -1;
 	}
 		
-	blk_queue_max_hw_segments(ubd_queue, MAX_SG);
 	if (fake_major != MAJOR_NR) {
 		char name[sizeof("ubd_nnn\0")];
 
@@ -896,12 +852,40 @@ int ubd_init(void)
 	driver_register(&ubd_driver);
 	for (i = 0; i < MAX_DEV; i++) 
 		ubd_add(i);
-
 	return 0;
 }
 
 late_initcall(ubd_init);
 
+int ubd_driver_init(void){
+	unsigned long stack;
+	int err;
+
+	/* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/
+	if(global_openflags.s){
+		printk(KERN_INFO "ubd: Synchronous mode\n");
+		/* Letting ubd=sync be like using ubd#s= instead of ubd#= is
+		 * enough. So use anyway the io thread. */
+	}
+	stack = alloc_stack(0, 0);
+	io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *), 
+				 &thread_fd);
+	if(io_pid < 0){
+		printk(KERN_ERR 
+		       "ubd : Failed to start I/O thread (errno = %d) - "
+		       "falling back to synchronous I/O\n", -io_pid);
+		io_pid = -1;
+		return(0);
+	}
+	err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr, 
+			     SA_INTERRUPT, "ubd", ubd_dev);
+	if(err != 0)
+		printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err);
+	return(err);
+}
+
+device_initcall(ubd_driver_init);
+
 static int ubd_open(struct inode *inode, struct file *filp)
 {
 	struct gendisk *disk = inode->i_bdev->bd_disk;
@@ -939,55 +923,105 @@ static int ubd_release(struct inode * inode, struct file * file)
 	return(0);
 }
 
-static void cowify_bitmap(struct io_thread_req *req, unsigned long *bitmap)
+static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask,
+			  __u64 *cow_offset, unsigned long *bitmap,
+			  __u64 bitmap_offset, unsigned long *bitmap_words,
+			  __u64 bitmap_len)
 {
-        __u64 sector = req->offset / req->sectorsize;
-        int i;
+	__u64 sector = io_offset >> 9;
+	int i, update_bitmap = 0;
+
+	for(i = 0; i < length >> 9; i++){
+		if(cow_mask != NULL)
+			ubd_set_bit(i, (unsigned char *) cow_mask);
+		if(ubd_test_bit(sector + i, (unsigned char *) bitmap))
+			continue;
 
-        for(i = 0; i < req->length / req->sectorsize; i++){
-                if(ubd_test_bit(sector + i, bitmap))
-                        continue;
+		update_bitmap = 1;
+		ubd_set_bit(sector + i, (unsigned char *) bitmap);
+	}
+
+	if(!update_bitmap)
+		return;
 
-                if(req->bitmap_start == -1)
-                        req->bitmap_start = sector + i;
-                req->bitmap_end = sector + i + 1;
+	*cow_offset = sector / (sizeof(unsigned long) * 8);
 
-                ubd_set_bit(sector + i, bitmap);
-        }
+	/* This takes care of the case where we're exactly at the end of the
+	 * device, and *cow_offset + 1 is off the end.  So, just back it up
+	 * by one word.  Thanks to Lynn Kerby for the fix and James McMechan
+	 * for the original diagnosis.
+	 */
+	if(*cow_offset == ((bitmap_len + sizeof(unsigned long) - 1) /
+			   sizeof(unsigned long) - 1))
+		(*cow_offset)--;
+
+	bitmap_words[0] = bitmap[*cow_offset];
+	bitmap_words[1] = bitmap[*cow_offset + 1];
+
+	*cow_offset *= sizeof(unsigned long);
+	*cow_offset += bitmap_offset;
+}
+
+static void cowify_req(struct io_thread_req *req, unsigned long *bitmap,
+		       __u64 bitmap_offset, __u64 bitmap_len)
+{
+	__u64 sector = req->offset >> 9;
+	int i;
+
+	if(req->length > (sizeof(req->sector_mask) * 8) << 9)
+		panic("Operation too long");
+
+	if(req->op == UBD_READ) {
+		for(i = 0; i < req->length >> 9; i++){
+			if(ubd_test_bit(sector + i, (unsigned char *) bitmap))
+				ubd_set_bit(i, (unsigned char *) 
+					    &req->sector_mask);
+                }
+	}
+	else cowify_bitmap(req->offset, req->length, &req->sector_mask,
+			   &req->cow_offset, bitmap, bitmap_offset,
+			   req->bitmap_words, bitmap_len);
 }
 
 /* Called with ubd_io_lock held */
-static int prepare_request(struct request *req, struct io_thread_req *io_req,
-                           unsigned long long offset, int page_offset,
-                           int len, struct page *page)
+static int prepare_request(struct request *req, struct io_thread_req *io_req)
 {
 	struct gendisk *disk = req->rq_disk;
 	struct ubd *dev = disk->private_data;
+	__u64 offset;
+	int len;
+
+	if(req->rq_status == RQ_INACTIVE) return(1);
 
 	/* This should be impossible now */
 	if((rq_data_dir(req) == WRITE) && !dev->openflags.w){
 		printk("Write attempted on readonly ubd device %s\n", 
 		       disk->disk_name);
-                ubd_end_request(req, 0, 0);
+		end_request(req, 0);
 		return(1);
 	}
 
+	offset = ((__u64) req->sector) << 9;
+	len = req->current_nr_sectors << 9;
+
 	io_req->fds[0] = (dev->cow.file != NULL) ? dev->cow.fd : dev->fd;
 	io_req->fds[1] = dev->fd;
+	io_req->cow_offset = -1;
 	io_req->offset = offset;
 	io_req->length = len;
 	io_req->error = 0;
-	io_req->op = (rq_data_dir(req) == READ) ? AIO_READ : AIO_WRITE;
+	io_req->sector_mask = 0;
+
+	io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE;
 	io_req->offsets[0] = 0;
 	io_req->offsets[1] = dev->cow.data_offset;
-        io_req->buffer = page_address(page) + page_offset;
+	io_req->buffer = req->buffer;
 	io_req->sectorsize = 1 << 9;
-        io_req->bitmap_offset = dev->cow.bitmap_offset;
-        io_req->bitmap_start = -1;
-        io_req->bitmap_end = -1;
 
-        if((dev->cow.file != NULL) && (io_req->op == UBD_WRITE))
-                cowify_bitmap(io_req, dev->cow.bitmap);
+	if(dev->cow.file != NULL)
+		cowify_req(io_req, dev->cow.bitmap, dev->cow.bitmap_offset,
+			   dev->cow.bitmap_len);
+
 	return(0);
 }
 
@@ -996,36 +1030,30 @@ static void do_ubd_request(request_queue_t *q)
 {
 	struct io_thread_req io_req;
 	struct request *req;
-	__u64 sector;
-	int err;
-
-	if(in_ubd)
-		return;
-	in_ubd = 1;
-	while((req = elv_next_request(q)) != NULL){
-		struct gendisk *disk = req->rq_disk;
-		struct ubd *dev = disk->private_data;
-		int n, i;
-
-		blkdev_dequeue_request(req);
-
-		sector = req->sector;
-		n = blk_rq_map_sg(q, req, dev->sg);
-
-		for(i = 0; i < n; i++){
-			struct scatterlist *sg = &dev->sg[i];
-
-			err = prepare_request(req, &io_req, sector << 9,
-					      sg->offset, sg->length,
-					      sg->page);
-			if(err)
-				continue;
-
-			sector += sg->length >> 9;
-			do_io(&io_req, req, dev->cow.bitmap);
+	int err, n;
+
+	if(thread_fd == -1){
+		while((req = elv_next_request(q)) != NULL){
+			err = prepare_request(req, &io_req);
+			if(!err){
+				do_io(&io_req);
+				__ubd_finish(req, io_req.error);
+			}
+		}
+	}
+	else {
+		if(do_ubd || (req = elv_next_request(q)) == NULL)
+			return;
+		err = prepare_request(req, &io_req);
+		if(!err){
+			do_ubd = ubd_handler;
+			n = os_write_file(thread_fd, (char *) &io_req,
+					 sizeof(io_req));
+			if(n != sizeof(io_req))
+				printk("write to io thread failed, "
+				       "errno = %d\n", -n);
 		}
 	}
-	in_ubd = 0;
 }
 
 static int ubd_ioctl(struct inode * inode, struct file * file,
@@ -1241,95 +1269,131 @@ int create_cow_file(char *cow_file, char *backing_file, struct openflags flags,
 	return(err);
 }
 
-void do_io(struct io_thread_req *req, struct request *r, unsigned long *bitmap)
+static int update_bitmap(struct io_thread_req *req)
 {
-        struct ubd_aio *aio;
-        struct bitmap_io *bitmap_io = NULL;
-        char *buf;
-        void *bitmap_buf = NULL;
-        unsigned long len, sector;
-        int nsectors, start, end, bit, err;
-        __u64 off;
-
-        if(req->bitmap_start != -1){
-                /* Round up to the nearest word */
-                int round = sizeof(unsigned long);
-                len = (req->bitmap_end - req->bitmap_start +
-                       round * 8 - 1) / (round * 8);
-                len *= round;
-
-                off = req->bitmap_start / (8 * round);
-                off *= round;
-
-                bitmap_io = kmalloc(sizeof(*bitmap_io), GFP_KERNEL);
-                if(bitmap_io == NULL){
-                        printk("Failed to kmalloc bitmap IO\n");
-                        req->error = 1;
-                        return;
-                }
+	int n;
 
-                bitmap_buf = kmalloc(len, GFP_KERNEL);
-                if(bitmap_buf == NULL){
-                        printk("do_io : kmalloc of bitmap chunk "
-                               "failed\n");
-                        kfree(bitmap_io);
-                        req->error = 1;
-                        return;
-                }
-                memcpy(bitmap_buf, &bitmap[off / sizeof(bitmap[0])], len);
-
-                *bitmap_io = ((struct bitmap_io)
-                        { .count	= ATOMIC_INIT(0),
-                          .aio		= INIT_AIO(AIO_WRITE, req->fds[1],
-                                                   bitmap_buf, len,
-                                                   req->bitmap_offset + off,
-                                                   ubd_reply_fd) } );
-        }
+	if(req->cow_offset == -1)
+		return(0);
 
-        nsectors = req->length / req->sectorsize;
-        start = 0;
-        end = nsectors;
-        bit = 0;
-        do {
-                if(bitmap != NULL){
-                        sector = req->offset / req->sectorsize;
-                        bit = ubd_test_bit(sector + start, bitmap);
-                        end = start;
-                        while((end < nsectors) &&
-                              (ubd_test_bit(sector + end, bitmap) == bit))
-                                end++;
-                }
+	n = os_seek_file(req->fds[1], req->cow_offset);
+	if(n < 0){
+		printk("do_io - bitmap lseek failed : err = %d\n", -n);
+		return(1);
+	}
 
-                off = req->offsets[bit] + req->offset +
-                        start * req->sectorsize;
-                len = (end - start) * req->sectorsize;
-                buf = &req->buffer[start * req->sectorsize];
+	n = os_write_file(req->fds[1], &req->bitmap_words,
+		          sizeof(req->bitmap_words));
+	if(n != sizeof(req->bitmap_words)){
+		printk("do_io - bitmap update failed, err = %d fd = %d\n", -n,
+		       req->fds[1]);
+		return(1);
+	}
 
-                aio = kmalloc(sizeof(*aio), GFP_KERNEL);
-                if(aio == NULL){
-                        req->error = 1;
-                        return;
-                }
+	return(0);
+}
 
-                *aio = ((struct ubd_aio)
-                        { .aio		= INIT_AIO(req->op, req->fds[bit], buf,
-                                                   len, off, ubd_reply_fd),
-                          .len		= len,
-                          .req		= r,
-                          .bitmap	= bitmap_io,
-                          .bitmap_buf 	= bitmap_buf });
-
-                if(aio->bitmap != NULL)
-                        atomic_inc(&aio->bitmap->count);
-
-                err = submit_aio(&aio->aio);
-                if(err){
-                        printk("do_io - submit_aio failed, "
-                               "err = %d\n", err);
-                        req->error = 1;
-                        return;
-                }
+void do_io(struct io_thread_req *req)
+{
+	char *buf;
+	unsigned long len;
+	int n, nsectors, start, end, bit;
+	int err;
+	__u64 off;
+
+	nsectors = req->length / req->sectorsize;
+	start = 0;
+	do {
+		bit = ubd_test_bit(start, (unsigned char *) &req->sector_mask);
+		end = start;
+		while((end < nsectors) &&
+		      (ubd_test_bit(end, (unsigned char *)
+				    &req->sector_mask) == bit))
+			end++;
+
+		off = req->offset + req->offsets[bit] +
+			start * req->sectorsize;
+		len = (end - start) * req->sectorsize;
+		buf = &req->buffer[start * req->sectorsize];
+
+		err = os_seek_file(req->fds[bit], off);
+		if(err < 0){
+			printk("do_io - lseek failed : err = %d\n", -err);
+			req->error = 1;
+			return;
+		}
+		if(req->op == UBD_READ){
+			n = 0;
+			do {
+				buf = &buf[n];
+				len -= n;
+				n = os_read_file(req->fds[bit], buf, len);
+				if (n < 0) {
+					printk("do_io - read failed, err = %d "
+					       "fd = %d\n", -n, req->fds[bit]);
+					req->error = 1;
+					return;
+				}
+			} while((n < len) && (n != 0));
+			if (n < len) memset(&buf[n], 0, len - n);
+		} else {
+			n = os_write_file(req->fds[bit], buf, len);
+			if(n != len){
+				printk("do_io - write failed err = %d "
+				       "fd = %d\n", -n, req->fds[bit]);
+				req->error = 1;
+				return;
+			}
+		}
+
+		start = end;
+	} while(start < nsectors);
 
-                start = end;
-        } while(start < nsectors);
+	req->error = update_bitmap(req);
 }
+
+/* Changed in start_io_thread, which is serialized by being called only
+ * from ubd_init, which is an initcall.
+ */
+int kernel_fd = -1;
+
+/* Only changed by the io thread */
+int io_count = 0;
+
+int io_thread(void *arg)
+{
+	struct io_thread_req req;
+	int n;
+
+	ignore_sigwinch_sig();
+	while(1){
+		n = os_read_file(kernel_fd, &req, sizeof(req));
+		if(n != sizeof(req)){
+			if(n < 0)
+				printk("io_thread - read failed, fd = %d, "
+				       "err = %d\n", kernel_fd, -n);
+			else {
+				printk("io_thread - short read, fd = %d, "
+				       "length = %d\n", kernel_fd, n);
+			}
+			continue;
+		}
+		io_count++;
+		do_io(&req);
+		n = os_write_file(kernel_fd, &req, sizeof(req));
+		if(n != sizeof(req))
+			printk("io_thread - write failed, fd = %d, err = %d\n",
+			       kernel_fd, -n);
+	}
+}
+
+/*
+ * Overrides for Emacs so that we follow Linus's tabbing style.
+ * Emacs will notice this stuff at the end of the file and automatically
+ * adjust the settings for this buffer only.  This must remain at the end
+ * of the file.
+ * ---------------------------------------------------------------------------
+ * Local variables:
+ * c-file-style: "linux"
+ * End:
+ */
diff --git a/arch/um/drivers/ubd_user.c b/arch/um/drivers/ubd_user.c
new file mode 100644
index 00000000000..b94d2bc4fe0
--- /dev/null
+++ b/arch/um/drivers/ubd_user.c
@@ -0,0 +1,75 @@
+/* 
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2001 Ridgerun,Inc (glonnon@ridgerun.com)
+ * Licensed under the GPL
+ */
+
+#include <stddef.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sched.h>
+#include <signal.h>
+#include <string.h>
+#include <netinet/in.h>
+#include <sys/time.h>
+#include <sys/socket.h>
+#include <sys/mman.h>
+#include <sys/param.h>
+#include "asm/types.h"
+#include "user_util.h"
+#include "kern_util.h"
+#include "user.h"
+#include "ubd_user.h"
+#include "os.h"
+#include "cow.h"
+
+#include <endian.h>
+#include <byteswap.h>
+
+void ignore_sigwinch_sig(void)
+{
+	signal(SIGWINCH, SIG_IGN);
+}
+
+int start_io_thread(unsigned long sp, int *fd_out)
+{
+	int pid, fds[2], err;
+
+	err = os_pipe(fds, 1, 1);
+	if(err < 0){
+		printk("start_io_thread - os_pipe failed, err = %d\n", -err);
+		goto out;
+	}
+
+	kernel_fd = fds[0];
+	*fd_out = fds[1];
+
+	pid = clone(io_thread, (void *) sp, CLONE_FILES | CLONE_VM | SIGCHLD,
+		    NULL);
+	if(pid < 0){
+		printk("start_io_thread - clone failed : errno = %d\n", errno);
+		err = -errno;
+		goto out_close;
+	}
+
+	return(pid);
+
+ out_close:
+	os_close_file(fds[0]);
+	os_close_file(fds[1]);
+	kernel_fd = -1;
+	*fd_out = -1;
+ out:
+	return(err);
+}
+
+/*
+ * Overrides for Emacs so that we follow Linus's tabbing style.
+ * Emacs will notice this stuff at the end of the file and automatically
+ * adjust the settings for this buffer only.  This must remain at the end
+ * of the file.
+ * ---------------------------------------------------------------------------
+ * Local variables:
+ * c-file-style: "linux"
+ * End:
+ */
diff --git a/arch/um/include/aio.h b/arch/um/include/aio.h
index 83f16877ab0..423bae9153f 100644
--- a/arch/um/include/aio.h
+++ b/arch/um/include/aio.h
@@ -14,27 +14,15 @@ struct aio_thread_reply {
 };
 
 struct aio_context {
-	enum aio_type type;
-	int fd;
-	void *data;
-	int len;
-	unsigned long long offset;
 	int reply_fd;
 	struct aio_context *next;
 };
 
-#define INIT_AIO(aio_type, aio_fd, aio_data, aio_len, aio_offset, \
-		 aio_reply_fd) \
-	{ .type 	= aio_type, \
-	  .fd		= aio_fd, \
-	  .data		= aio_data, \
-	  .len		= aio_len, \
-	  .offset	= aio_offset, \
-	  .reply_fd	= aio_reply_fd }
-
 #define INIT_AIO_CONTEXT { .reply_fd	= -1, \
 			   .next	= NULL }
 
-extern int submit_aio(struct aio_context *aio);
+extern int submit_aio(enum aio_type type, int fd, char *buf, int len,
+		      unsigned long long offset, int reply_fd,
+                      struct aio_context *aio);
 
 #endif
diff --git a/arch/um/include/common-offsets.h b/arch/um/include/common-offsets.h
index 782ac3a3baf..356390d1f8b 100644
--- a/arch/um/include/common-offsets.h
+++ b/arch/um/include/common-offsets.h
@@ -1,7 +1,7 @@
 /* for use by sys-$SUBARCH/kernel-offsets.c */
 
-OFFSET(TASK_REGS, task_struct, thread.regs);
-OFFSET(TASK_PID, task_struct, pid);
+OFFSET(HOST_TASK_REGS, task_struct, thread.regs);
+OFFSET(HOST_TASK_PID, task_struct, pid);
 DEFINE(UM_KERN_PAGE_SIZE, PAGE_SIZE);
 DEFINE(UM_NSEC_PER_SEC, NSEC_PER_SEC);
 DEFINE_STR(UM_KERN_EMERG, KERN_EMERG);
diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index 583329d0a53..2e58e304b8b 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -6,6 +6,7 @@
 #ifndef __OS_H__
 #define __OS_H__
 
+#include "uml-config.h"
 #include "asm/types.h"
 #include "../os/include/file.h"
 
@@ -157,6 +158,14 @@ extern int os_lock_file(int fd, int excl);
 extern void os_early_checks(void);
 extern int can_do_skas(void);
 
+/* Make sure they are clear when running in TT mode. Required by
+ * SEGV_MAYBE_FIXABLE */
+#ifdef UML_CONFIG_MODE_SKAS
+#define clear_can_do_skas() do { ptrace_faultinfo = proc_mm = 0; } while (0)
+#else
+#define clear_can_do_skas() do {} while (0)
+#endif
+
 /* mem.c */
 extern int create_mem_file(unsigned long len);
 
diff --git a/arch/um/include/registers.h b/arch/um/include/registers.h
index 0a35e6d0baa..4892e5fcef0 100644
--- a/arch/um/include/registers.h
+++ b/arch/um/include/registers.h
@@ -15,16 +15,6 @@ extern void save_registers(int pid, union uml_pt_regs *regs);
 extern void restore_registers(int pid, union uml_pt_regs *regs);
 extern void init_registers(int pid);
 extern void get_safe_registers(unsigned long * regs);
+extern void get_thread_regs(union uml_pt_regs *uml_regs, void *buffer);
 
 #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_ptregs.h b/arch/um/include/skas_ptregs.h
new file mode 100644
index 00000000000..73db19e9c07
--- /dev/null
+++ b/arch/um/include/skas_ptregs.h
@@ -0,0 +1,6 @@
+#ifndef __SKAS_PT_REGS_
+#define __SKAS_PT_REGS_
+
+#include <user_constants.h>
+
+#endif
diff --git a/arch/um/include/sysdep-i386/sc.h b/arch/um/include/sysdep-i386/sc.h
new file mode 100644
index 00000000000..c57d1780ad3
--- /dev/null
+++ b/arch/um/include/sysdep-i386/sc.h
@@ -0,0 +1,44 @@
+#ifndef __SYSDEP_I386_SC_H
+#define __SYSDEP_I386_SC_H
+
+#include <user_constants.h>
+
+#define SC_OFFSET(sc, field) \
+	*((unsigned long *) &(((char *) (sc))[HOST_##field]))
+#define SC_FP_OFFSET(sc, field) \
+	*((unsigned long *) &(((char *) (SC_FPSTATE(sc)))[HOST_##field]))
+#define SC_FP_OFFSET_PTR(sc, field, type) \
+	((type *) &(((char *) (SC_FPSTATE(sc)))[HOST_##field]))
+
+#define SC_IP(sc) SC_OFFSET(sc, SC_IP)
+#define SC_SP(sc) SC_OFFSET(sc, SC_SP)
+#define SC_FS(sc) SC_OFFSET(sc, SC_FS)
+#define SC_GS(sc) SC_OFFSET(sc, SC_GS)
+#define SC_DS(sc) SC_OFFSET(sc, SC_DS)
+#define SC_ES(sc) SC_OFFSET(sc, SC_ES)
+#define SC_SS(sc) SC_OFFSET(sc, SC_SS)
+#define SC_CS(sc) SC_OFFSET(sc, SC_CS)
+#define SC_EFLAGS(sc) SC_OFFSET(sc, SC_EFLAGS)
+#define SC_EAX(sc) SC_OFFSET(sc, SC_EAX)
+#define SC_EBX(sc) SC_OFFSET(sc, SC_EBX)
+#define SC_ECX(sc) SC_OFFSET(sc, SC_ECX)
+#define SC_EDX(sc) SC_OFFSET(sc, SC_EDX)
+#define SC_EDI(sc) SC_OFFSET(sc, SC_EDI)
+#define SC_ESI(sc) SC_OFFSET(sc, SC_ESI)
+#define SC_EBP(sc) SC_OFFSET(sc, SC_EBP)
+#define SC_TRAPNO(sc) SC_OFFSET(sc, SC_TRAPNO)
+#define SC_ERR(sc) SC_OFFSET(sc, SC_ERR)
+#define SC_CR2(sc) SC_OFFSET(sc, SC_CR2)
+#define SC_FPSTATE(sc) SC_OFFSET(sc, SC_FPSTATE)
+#define SC_SIGMASK(sc) SC_OFFSET(sc, SC_SIGMASK)
+#define SC_FP_CW(sc) SC_FP_OFFSET(sc, SC_FP_CW)
+#define SC_FP_SW(sc) SC_FP_OFFSET(sc, SC_FP_SW)
+#define SC_FP_TAG(sc) SC_FP_OFFSET(sc, SC_FP_TAG)
+#define SC_FP_IPOFF(sc) SC_FP_OFFSET(sc, SC_FP_IPOFF)
+#define SC_FP_CSSEL(sc) SC_FP_OFFSET(sc, SC_FP_CSSEL)
+#define SC_FP_DATAOFF(sc) SC_FP_OFFSET(sc, SC_FP_DATAOFF)
+#define SC_FP_DATASEL(sc) SC_FP_OFFSET(sc, SC_FP_DATASEL)
+#define SC_FP_ST(sc) SC_FP_OFFSET_PTR(sc, SC_FP_ST, struct _fpstate)
+#define SC_FXSR_ENV(sc) SC_FP_OFFSET_PTR(sc, SC_FXSR_ENV, void)
+
+#endif
diff --git a/arch/um/include/sysdep-i386/sigcontext.h b/arch/um/include/sysdep-i386/sigcontext.h
index 1fe72926516..23fd2644d7e 100644
--- a/arch/um/include/sysdep-i386/sigcontext.h
+++ b/arch/um/include/sysdep-i386/sigcontext.h
@@ -6,6 +6,7 @@
 #ifndef __SYS_SIGCONTEXT_I386_H
 #define __SYS_SIGCONTEXT_I386_H
 
+#include "uml-config.h"
 #include <sysdep/sc.h>
 
 #define IP_RESTART_SYSCALL(ip) ((ip) -= 2)
@@ -26,7 +27,14 @@
 #define SC_START_SYSCALL(sc) do SC_EAX(sc) = -ENOSYS; while(0)
 
 /* This is Page Fault */
-#define SEGV_IS_FIXABLE(fi) ((fi)->trap_no == 14)
+#define SEGV_IS_FIXABLE(fi)	((fi)->trap_no == 14)
+
+/* SKAS3 has no trap_no on i386, but get_skas_faultinfo() sets it to 0. */
+#ifdef UML_CONFIG_MODE_SKAS
+#define SEGV_MAYBE_FIXABLE(fi)	((fi)->trap_no == 0 && ptrace_faultinfo)
+#else
+#define SEGV_MAYBE_FIXABLE(fi)	0
+#endif
 
 extern unsigned long *sc_sigmask(void *sc_ptr);
 extern int sc_get_fpregs(unsigned long buf, void *sc_ptr);
diff --git a/arch/um/include/sysdep-i386/thread.h b/arch/um/include/sysdep-i386/thread.h
new file mode 100644
index 00000000000..243fed44d78
--- /dev/null
+++ b/arch/um/include/sysdep-i386/thread.h
@@ -0,0 +1,11 @@
+#ifndef __UM_THREAD_H
+#define __UM_THREAD_H
+
+#include <kern_constants.h>
+
+#define TASK_DEBUGREGS(task) ((unsigned long *) &(((char *) (task))[HOST_TASK_DEBUGREGS]))
+#ifdef UML_CONFIG_MODE_TT
+#define TASK_EXTERN_PID(task) *((int *) &(((char *) (task))[HOST_TASK_EXTERN_PID]))
+#endif
+
+#endif
diff --git a/arch/um/include/sysdep-x86_64/ptrace.h b/arch/um/include/sysdep-x86_64/ptrace.h
index 331aa2d1f3f..8d353f0feec 100644
--- a/arch/um/include/sysdep-x86_64/ptrace.h
+++ b/arch/um/include/sysdep-x86_64/ptrace.h
@@ -183,10 +183,6 @@ struct syscall_args {
                 case RBP: val = UPT_RBP(regs); break; \
                 case ORIG_RAX: val = UPT_ORIG_RAX(regs); break; \
                 case CS: val = UPT_CS(regs); break; \
-                case DS: val = UPT_DS(regs); break; \
-                case ES: val = UPT_ES(regs); break; \
-                case FS: val = UPT_FS(regs); break; \
-                case GS: val = UPT_GS(regs); break; \
                 case EFLAGS: val = UPT_EFLAGS(regs); break; \
                 default :  \
                         panic("Bad register in UPT_REG : %d\n", reg);  \
@@ -218,10 +214,6 @@ struct syscall_args {
                 case RBP: UPT_RBP(regs) = __upt_val; break; \
                 case ORIG_RAX: UPT_ORIG_RAX(regs) = __upt_val; break; \
                 case CS: UPT_CS(regs) = __upt_val; break; \
-                case DS: UPT_DS(regs) = __upt_val; break; \
-                case ES: UPT_ES(regs) = __upt_val; break; \
-                case FS: UPT_FS(regs) = __upt_val; break; \
-                case GS: UPT_GS(regs) = __upt_val; break; \
                 case EFLAGS: UPT_EFLAGS(regs) = __upt_val; break; \
                 default :  \
                         panic("Bad register in UPT_SET : %d\n", reg);  \
diff --git a/arch/um/include/sysdep-x86_64/sc.h b/arch/um/include/sysdep-x86_64/sc.h
new file mode 100644
index 00000000000..a160d9fcc59
--- /dev/null
+++ b/arch/um/include/sysdep-x86_64/sc.h
@@ -0,0 +1,45 @@
+#ifndef __SYSDEP_X86_64_SC_H
+#define __SYSDEP_X86_64_SC_H
+
+/* Copyright (C) 2003 - 2004 PathScale, Inc
+ * Released under the GPL
+ */
+
+#include <user_constants.h>
+
+#define SC_OFFSET(sc, field) \
+	 *((unsigned long *) &(((char *) (sc))[HOST_##field]))
+
+#define SC_RBX(sc) SC_OFFSET(sc, SC_RBX)
+#define SC_RCX(sc) SC_OFFSET(sc, SC_RCX)
+#define SC_RDX(sc) SC_OFFSET(sc, SC_RDX)
+#define SC_RSI(sc) SC_OFFSET(sc, SC_RSI)
+#define SC_RDI(sc) SC_OFFSET(sc, SC_RDI)
+#define SC_RBP(sc) SC_OFFSET(sc, SC_RBP)
+#define SC_RAX(sc) SC_OFFSET(sc, SC_RAX)
+#define SC_R8(sc) SC_OFFSET(sc, SC_R8)
+#define SC_R9(sc) SC_OFFSET(sc, SC_R9)
+#define SC_R10(sc) SC_OFFSET(sc, SC_R10)
+#define SC_R11(sc) SC_OFFSET(sc, SC_R11)
+#define SC_R12(sc) SC_OFFSET(sc, SC_R12)
+#define SC_R13(sc) SC_OFFSET(sc, SC_R13)
+#define SC_R14(sc) SC_OFFSET(sc, SC_R14)
+#define SC_R15(sc) SC_OFFSET(sc, SC_R15)
+#define SC_IP(sc) SC_OFFSET(sc, SC_IP)
+#define SC_SP(sc) SC_OFFSET(sc, SC_SP)
+#define SC_CR2(sc) SC_OFFSET(sc, SC_CR2)
+#define SC_ERR(sc) SC_OFFSET(sc, SC_ERR)
+#define SC_TRAPNO(sc) SC_OFFSET(sc, SC_TRAPNO)
+#define SC_CS(sc) SC_OFFSET(sc, SC_CS)
+#define SC_FS(sc) SC_OFFSET(sc, SC_FS)
+#define SC_GS(sc) SC_OFFSET(sc, SC_GS)
+#define SC_EFLAGS(sc) SC_OFFSET(sc, SC_EFLAGS)
+#define SC_SIGMASK(sc) SC_OFFSET(sc, SC_SIGMASK)
+#if 0
+#define SC_ORIG_RAX(sc) SC_OFFSET(sc, SC_ORIG_RAX)
+#define SC_DS(sc) SC_OFFSET(sc, SC_DS)
+#define SC_ES(sc) SC_OFFSET(sc, SC_ES)
+#define SC_SS(sc) SC_OFFSET(sc, SC_SS)
+#endif
+
+#endif
diff --git a/arch/um/include/sysdep-x86_64/sigcontext.h b/arch/um/include/sysdep-x86_64/sigcontext.h
index 2a78260d15a..41073235e7a 100644
--- a/arch/um/include/sysdep-x86_64/sigcontext.h
+++ b/arch/um/include/sysdep-x86_64/sigcontext.h
@@ -31,7 +31,10 @@
 #define SC_START_SYSCALL(sc) do SC_RAX(sc) = -ENOSYS; while(0)
 
 /* This is Page Fault */
-#define SEGV_IS_FIXABLE(fi) ((fi)->trap_no == 14)
+#define SEGV_IS_FIXABLE(fi)	((fi)->trap_no == 14)
+
+/* No broken SKAS API, which doesn't pass trap_no, here. */
+#define SEGV_MAYBE_FIXABLE(fi)	0
 
 extern unsigned long *sc_sigmask(void *sc_ptr);
 
diff --git a/arch/um/include/sysdep-x86_64/thread.h b/arch/um/include/sysdep-x86_64/thread.h
new file mode 100644
index 00000000000..cbef3e1697f
--- /dev/null
+++ b/arch/um/include/sysdep-x86_64/thread.h
@@ -0,0 +1,10 @@
+#ifndef __UM_THREAD_H
+#define __UM_THREAD_H
+
+#include <kern_constants.h>
+
+#ifdef UML_CONFIG_MODE_TT
+#define TASK_EXTERN_PID(task) *((int *) &(((char *) (task))[HOST_TASK_EXTERN_PID]))
+#endif
+
+#endif
diff --git a/arch/um/include/task.h b/arch/um/include/task.h
new file mode 100644
index 00000000000..6375ba7203c
--- /dev/null
+++ b/arch/um/include/task.h
@@ -0,0 +1,9 @@
+#ifndef __TASK_H
+#define __TASK_H
+
+#include <kern_constants.h>
+
+#define TASK_REGS(task) ((union uml_pt_regs *) &(((char *) (task))[HOST_TASK_REGS]))
+#define TASK_PID(task) *((int *) &(((char *) (task))[HOST_TASK_PID]))
+
+#endif
diff --git a/arch/um/include/user.h b/arch/um/include/user.h
index 57ee9e26122..0f865ef4691 100644
--- a/arch/um/include/user.h
+++ b/arch/um/include/user.h
@@ -14,7 +14,9 @@ extern void *um_kmalloc_atomic(int size);
 extern void kfree(void *ptr);
 extern int in_aton(char *str);
 extern int open_gdb_chan(void);
-extern int strlcpy(char *, const char *, int);
+/* These use size_t, however unsigned long is correct on both i386 and x86_64. */
+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 vfree(void *ptr);
 
diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c
index dcd81497199..bbf94bf2921 100644
--- a/arch/um/kernel/irq.c
+++ b/arch/um/kernel/irq.c
@@ -9,7 +9,6 @@
 #include "linux/kernel.h"
 #include "linux/module.h"
 #include "linux/smp.h"
-#include "linux/irq.h"
 #include "linux/kernel_stat.h"
 #include "linux/interrupt.h"
 #include "linux/random.h"
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index ea008b031a8..462cc9d6538 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -252,7 +252,7 @@ void paging_init(void)
 #endif
 }
 
-struct page *arch_validate(struct page *page, int mask, int order)
+struct page *arch_validate(struct page *page, gfp_t mask, int order)
 {
 	unsigned long addr, zero = 0;
 	int i;
diff --git a/arch/um/kernel/process_kern.c b/arch/um/kernel/process_kern.c
index 39cf568ccfa..0d73ceeece7 100644
--- a/arch/um/kernel/process_kern.c
+++ b/arch/um/kernel/process_kern.c
@@ -80,9 +80,10 @@ void free_stack(unsigned long stack, int order)
 unsigned long alloc_stack(int order, int atomic)
 {
 	unsigned long page;
-	int flags = GFP_KERNEL;
+	gfp_t flags = GFP_KERNEL;
 
-	if(atomic) flags |= GFP_ATOMIC;
+	if (atomic)
+		flags = GFP_ATOMIC;
 	page = __get_free_pages(flags, order);
 	if(page == 0)
 		return(0);
diff --git a/arch/um/kernel/sigio_user.c b/arch/um/kernel/sigio_user.c
index e89218958f3..a52751108aa 100644
--- a/arch/um/kernel/sigio_user.c
+++ b/arch/um/kernel/sigio_user.c
@@ -340,7 +340,7 @@ static int setup_initial_poll(int fd)
 {
 	struct pollfd *p;
 
-	p = um_kmalloc(sizeof(struct pollfd));
+	p = um_kmalloc_atomic(sizeof(struct pollfd));
 	if(p == NULL){
 		printk("setup_initial_poll : failed to allocate poll\n");
 		return(-1);
diff --git a/arch/um/kernel/skas/Makefile b/arch/um/kernel/skas/Makefile
index db36c7c9594..8de471b59c1 100644
--- a/arch/um/kernel/skas/Makefile
+++ b/arch/um/kernel/skas/Makefile
@@ -6,8 +6,6 @@
 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
 
-subdir- := util
-
 USER_OBJS := process.o clone.o
 
 include arch/um/scripts/Makefile.rules
diff --git a/arch/um/kernel/skas/util/Makefile b/arch/um/kernel/skas/util/Makefile
deleted file mode 100644
index f7b7eba8334..00000000000
--- a/arch/um/kernel/skas/util/Makefile
+++ /dev/null
@@ -1,5 +0,0 @@
-hostprogs-y		:= mk_ptregs
-always			:= $(hostprogs-y)
-
-mk_ptregs-objs := mk_ptregs-$(SUBARCH).o
-HOSTCFLAGS_mk_ptregs-$(SUBARCH).o := -I$(objtree)/arch/um
diff --git a/arch/um/kernel/skas/util/mk_ptregs-i386.c b/arch/um/kernel/skas/util/mk_ptregs-i386.c
deleted file mode 100644
index 1f96e1eeb8a..00000000000
--- a/arch/um/kernel/skas/util/mk_ptregs-i386.c
+++ /dev/null
@@ -1,49 +0,0 @@
-#include <stdio.h>
-#include <user-offsets.h>
-
-#define SHOW(name) printf("#define %s %d\n", #name, name)
-
-int main(int argc, char **argv)
-{
-	printf("/* Automatically generated by "
-	       "arch/um/kernel/skas/util/mk_ptregs */\n");
-	printf("\n");
-	printf("#ifndef __SKAS_PT_REGS_\n");
-	printf("#define __SKAS_PT_REGS_\n");
-	printf("\n");
-	SHOW(HOST_FRAME_SIZE);
-	SHOW(HOST_FP_SIZE);
-	SHOW(HOST_XFP_SIZE);
-
-	SHOW(HOST_IP);
-	SHOW(HOST_SP);
-	SHOW(HOST_EFLAGS);
-	SHOW(HOST_EAX);
-	SHOW(HOST_EBX);
-	SHOW(HOST_ECX);
-	SHOW(HOST_EDX);
-	SHOW(HOST_ESI);
-	SHOW(HOST_EDI);
-	SHOW(HOST_EBP);
-	SHOW(HOST_CS);
-	SHOW(HOST_SS);
-	SHOW(HOST_DS);
-	SHOW(HOST_FS);
-	SHOW(HOST_ES);
-	SHOW(HOST_GS);
-
-	printf("\n");
-	printf("#endif\n");
-	return(0);
-}
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/kernel/skas/util/mk_ptregs-x86_64.c b/arch/um/kernel/skas/util/mk_ptregs-x86_64.c
deleted file mode 100644
index 5fccbfe35f7..00000000000
--- a/arch/um/kernel/skas/util/mk_ptregs-x86_64.c
+++ /dev/null
@@ -1,66 +0,0 @@
-/*
- * Copyright 2003 PathScale, Inc.
- *
- * Licensed under the GPL
- */
-
-#include <stdio.h>
-#include <user-offsets.h>
-
-#define SHOW(name) \
-	printf("#define %s (%d / sizeof(unsigned long))\n", #name, name)
-
-int main(int argc, char **argv)
-{
-	printf("/* Automatically generated by "
-	       "arch/um/kernel/skas/util/mk_ptregs */\n");
-	printf("\n");
-	printf("#ifndef __SKAS_PT_REGS_\n");
-	printf("#define __SKAS_PT_REGS_\n");
-	SHOW(HOST_FRAME_SIZE);
-	SHOW(HOST_RBX);
-	SHOW(HOST_RCX);
-	SHOW(HOST_RDI);
-	SHOW(HOST_RSI);
-	SHOW(HOST_RDX);
-	SHOW(HOST_RBP);
-	SHOW(HOST_RAX);
-	SHOW(HOST_R8);
-	SHOW(HOST_R9);
-	SHOW(HOST_R10);
-	SHOW(HOST_R11);
-	SHOW(HOST_R12);
-	SHOW(HOST_R13);
-	SHOW(HOST_R14);
-	SHOW(HOST_R15);
-	SHOW(HOST_ORIG_RAX);
-	SHOW(HOST_CS);
-	SHOW(HOST_SS);
-	SHOW(HOST_EFLAGS);
-#if 0
-	SHOW(HOST_FS);
-	SHOW(HOST_GS);
-	SHOW(HOST_DS);
-	SHOW(HOST_ES);
-#endif
-
-	SHOW(HOST_IP);
-	SHOW(HOST_SP);
-	printf("#define HOST_FP_SIZE 0\n");
-	printf("#define HOST_XFP_SIZE 0\n");
-	printf("\n");
-	printf("\n");
-	printf("#endif\n");
-	return(0);
-}
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/kernel/sysrq.c b/arch/um/kernel/sysrq.c
index f80850091e7..b331e970002 100644
--- a/arch/um/kernel/sysrq.c
+++ b/arch/um/kernel/sysrq.c
@@ -62,13 +62,7 @@ void show_stack(struct task_struct *task, unsigned long *esp)
 
 	if (esp == NULL) {
 		if (task != current && task != NULL) {
-			/* XXX: Isn't this bogus? I.e. isn't this the
-			 * *userspace* stack of this task? If not so, use this
-			 * even when task == current (as in i386).
-			 */
 			esp = (unsigned long *) KSTK_ESP(task);
-			/* Which one? No actual difference - just coding style.*/
-			//esp = (unsigned long *) PT_REGS_IP(&task->thread.regs);
 		} else {
 			esp = (unsigned long *) &esp;
 		}
@@ -84,5 +78,5 @@ void show_stack(struct task_struct *task, unsigned long *esp)
 	}
 
 	printk("Call Trace: \n");
-	show_trace(current, esp);
+	show_trace(task, esp);
 }
diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c
index 0a562c3c0fd..f5b0636f9ad 100644
--- a/arch/um/kernel/tlb.c
+++ b/arch/um/kernel/tlb.c
@@ -193,12 +193,12 @@ void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
                 r = pte_read(*npte);
                 w = pte_write(*npte);
                 x = pte_exec(*npte);
-                if(!pte_dirty(*npte))
-                        w = 0;
-                if(!pte_young(*npte)){
-                        r = 0;
-                        w = 0;
-                }
+		if (!pte_young(*npte)) {
+			r = 0;
+			w = 0;
+		} else if (!pte_dirty(*npte)) {
+			w = 0;
+		}
                 if(force || pte_newpage(*npte)){
                         if(pte_present(*npte))
 			  ret = add_mmap(addr,
diff --git a/arch/um/kernel/trap_kern.c b/arch/um/kernel/trap_kern.c
index 87cc6fd76ce..95c8f8733ba 100644
--- a/arch/um/kernel/trap_kern.c
+++ b/arch/um/kernel/trap_kern.c
@@ -18,6 +18,7 @@
 #include "asm/a.out.h"
 #include "asm/current.h"
 #include "asm/irq.h"
+#include "sysdep/sigcontext.h"
 #include "user_util.h"
 #include "kern_util.h"
 #include "kern.h"
@@ -25,6 +26,9 @@
 #include "mconsole_kern.h"
 #include "mem.h"
 #include "mem_kern.h"
+#ifdef CONFIG_MODE_SKAS
+#include "skas.h"
+#endif
 
 /* Note this is constrained to return 0, -EFAULT, -EACCESS, -ENOMEM by segv(). */
 int handle_page_fault(unsigned long address, unsigned long ip, 
@@ -39,6 +43,12 @@ int handle_page_fault(unsigned long address, unsigned long ip,
 	int err = -EFAULT;
 
 	*code_out = SEGV_MAPERR;
+
+	/* If the fault was during atomic operation, don't take the fault, just
+	 * fail. */
+	if (in_atomic())
+		goto out_nosemaphore;
+
 	down_read(&mm->mmap_sem);
 	vma = find_vma(mm, address);
 	if(!vma) 
@@ -89,6 +99,7 @@ survive:
 	flush_tlb_page(vma, address);
 out:
 	up_read(&mm->mmap_sem);
+out_nosemaphore:
 	return(err);
 
 /*
@@ -125,7 +136,15 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void *sc)
         }
 	else if(current->mm == NULL)
 		panic("Segfault with no mm");
-	err = handle_page_fault(address, ip, is_write, is_user, &si.si_code);
+
+	if (SEGV_IS_FIXABLE(&fi) || SEGV_MAYBE_FIXABLE(&fi))
+		err = handle_page_fault(address, ip, is_write, is_user, &si.si_code);
+	else {
+		err = -EFAULT;
+		/* A thread accessed NULL, we get a fault, but CR2 is invalid.
+		 * This code is used in __do_copy_from_user() of TT mode. */
+		address = 0;
+	}
 
 	catcher = current->thread.fault_catcher;
 	if(!err)
diff --git a/arch/um/kernel/tt/uaccess_user.c b/arch/um/kernel/tt/uaccess_user.c
index f01475512ec..8c220f054b6 100644
--- a/arch/um/kernel/tt/uaccess_user.c
+++ b/arch/um/kernel/tt/uaccess_user.c
@@ -22,8 +22,15 @@ int __do_copy_from_user(void *to, const void *from, int n,
 			       __do_copy, &faulted);
 	TASK_REGS(get_current())->tt = save;
 
-	if(!faulted) return(0);
-	else return(n - (fault - (unsigned long) from));
+	if(!faulted)
+		return 0;
+	else if (fault)
+		return n - (fault - (unsigned long) from);
+	else
+		/* In case of a general protection fault, we don't have the
+		 * fault address, so NULL is used instead. Pretend we didn't
+		 * copy anything. */
+		return n;
 }
 
 static void __do_strncpy(void *dst, const void *src, int count)
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index f0a275947d3..93dc782dc1c 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -334,6 +334,8 @@ int linux_main(int argc, char **argv)
 		add_arg(DEFAULT_COMMAND_LINE);
 
 	os_early_checks();
+	if (force_tt)
+		clear_can_do_skas();
 	mode_tt = force_tt ? 1 : !can_do_skas();
 #ifndef CONFIG_MODE_TT
 	if (mode_tt) {
diff --git a/arch/um/kernel/umid.c b/arch/um/kernel/umid.c
index 186c2888501..0b21d59ba0c 100644
--- a/arch/um/kernel/umid.c
+++ b/arch/um/kernel/umid.c
@@ -31,6 +31,8 @@ static char *uml_dir = UML_DIR;
 /* Changed by set_umid */
 static int umid_is_random = 1;
 static int umid_inited = 0;
+/* Have we created the files? Should we remove them? */
+static int umid_owned = 0;
 
 static int make_umid(int (*printer)(const char *fmt, ...));
 
@@ -82,20 +84,21 @@ int __init umid_file_name(char *name, char *buf, int len)
 
 extern int tracing_pid;
 
-static int __init create_pid_file(void)
+static void __init create_pid_file(void)
 {
 	char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")];
 	char pid[sizeof("nnnnn\0")];
 	int fd, n;
 
-	if(umid_file_name("pid", file, sizeof(file))) return 0;
+	if(umid_file_name("pid", file, sizeof(file)))
+		return;
 
 	fd = os_open_file(file, of_create(of_excl(of_rdwr(OPENFLAGS()))), 
 			  0644);
 	if(fd < 0){
 		printf("Open of machine pid file \"%s\" failed: %s\n",
 		       file, strerror(-fd));
-		return 0;
+		return;
 	}
 
 	sprintf(pid, "%d\n", os_getpid());
@@ -103,7 +106,6 @@ static int __init create_pid_file(void)
 	if(n != strlen(pid))
 		printf("Write of pid file failed - err = %d\n", -n);
 	os_close_file(fd);
-	return 0;
 }
 
 static int actually_do_remove(char *dir)
@@ -147,7 +149,8 @@ static int actually_do_remove(char *dir)
 void remove_umid_dir(void)
 {
 	char dir[strlen(uml_dir) + UMID_LEN + 1];
-	if(!umid_inited) return;
+	if (!umid_owned)
+		return;
 
 	sprintf(dir, "%s%s", uml_dir, umid);
 	actually_do_remove(dir);
@@ -155,11 +158,12 @@ void remove_umid_dir(void)
 
 char *get_umid(int only_if_set)
 {
-	if(only_if_set && umid_is_random) return(NULL);
-	return(umid);
+	if(only_if_set && umid_is_random)
+		return NULL;
+	return umid;
 }
 
-int not_dead_yet(char *dir)
+static int not_dead_yet(char *dir)
 {
 	char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")];
 	char pid[sizeof("nnnnn\0")], *end;
@@ -193,7 +197,8 @@ int not_dead_yet(char *dir)
 		   (p == CHOOSE_MODE(tracing_pid, os_getpid())))
 			dead = 1;
 	}
-	if(!dead) return(1);
+	if(!dead)
+		return(1);
 	return(actually_do_remove(dir));
 }
 
@@ -232,16 +237,13 @@ static int __init make_uml_dir(void)
 		strlcpy(dir, home, sizeof(dir));
 		uml_dir++;
 	}
+	strlcat(dir, uml_dir, sizeof(dir));
 	len = strlen(dir);
-	strncat(dir, uml_dir, sizeof(dir) - len);
-	len = strlen(dir);
-	if((len > 0) && (len < sizeof(dir) - 1) && (dir[len - 1] != '/')){
-		dir[len] = '/';
-		dir[len + 1] = '\0';
-	}
+	if (len > 0 && dir[len - 1] != '/')
+		strlcat(dir, "/", sizeof(dir));
 
 	uml_dir = malloc(strlen(dir) + 1);
-	if(uml_dir == NULL){
+	if (uml_dir == NULL) {
 		printf("make_uml_dir : malloc failed, errno = %d\n", errno);
 		exit(1);
 	}
@@ -286,6 +288,7 @@ static int __init make_umid(int (*printer)(const char *fmt, ...))
 		if(errno == EEXIST){
 			if(not_dead_yet(tmp)){
 				(*printer)("umid '%s' is in use\n", umid);
+				umid_owned = 0;
 				return(-1);
 			}
 			err = mkdir(tmp, 0777);
@@ -296,7 +299,8 @@ static int __init make_umid(int (*printer)(const char *fmt, ...))
 		return(-1);
 	}
 
-	return(0);
+	umid_owned = 1;
+	return 0;
 }
 
 __uml_setup("uml_dir=", set_uml_dir,
@@ -309,7 +313,8 @@ static int __init make_umid_setup(void)
 	/* one function with the ordering we need ... */
 	make_uml_dir();
 	make_umid(printf);
-	return create_pid_file();
+	create_pid_file();
+	return 0;
 }
 __uml_postsetup(make_umid_setup);
 
diff --git a/arch/um/os-Linux/aio.c b/arch/um/os-Linux/aio.c
index f6e64026f99..41cfb094420 100644
--- a/arch/um/os-Linux/aio.c
+++ b/arch/um/os-Linux/aio.c
@@ -6,7 +6,6 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <signal.h>
-#include <string.h>
 #include <errno.h>
 #include <sched.h>
 #include <sys/syscall.h>
@@ -17,31 +16,18 @@
 #include "user.h"
 #include "mode.h"
 
+struct aio_thread_req {
+        enum aio_type type;
+        int io_fd;
+        unsigned long long offset;
+        char *buf;
+        int len;
+        struct aio_context *aio;
+};
+
 static int aio_req_fd_r = -1;
 static int aio_req_fd_w = -1;
 
-static int update_aio(struct aio_context *aio, int res)
-{
-        if(res < 0)
-                aio->len = res;
-        else if((res == 0) && (aio->type == AIO_READ)){
-                /* This is the EOF case - we have hit the end of the file
-                 * and it ends in a partial block, so we fill the end of
-                 * the block with zeros and claim success.
-                 */
-                memset(aio->data, 0, aio->len);
-                aio->len = 0;
-        }
-        else if(res > 0){
-                aio->len -= res;
-                aio->data += res;
-                aio->offset += res;
-                return aio->len;
-        }
-
-        return 0;
-}
-
 #if defined(HAVE_AIO_ABI)
 #include <linux/aio_abi.h>
 
@@ -80,7 +66,8 @@ static long io_getevents(aio_context_t ctx_id, long min_nr, long nr,
  * that it now backs the mmapped area.
  */
 
-static int do_aio(aio_context_t ctx, struct aio_context *aio)
+static int do_aio(aio_context_t ctx, enum aio_type type, int fd, char *buf,
+                  int len, unsigned long long offset, struct aio_context *aio)
 {
         struct iocb iocb, *iocbp = &iocb;
         char c;
@@ -88,39 +75,40 @@ static int do_aio(aio_context_t ctx, struct aio_context *aio)
 
         iocb = ((struct iocb) { .aio_data 	= (unsigned long) aio,
                                 .aio_reqprio	= 0,
-                                .aio_fildes	= aio->fd,
-                                .aio_buf	= (unsigned long) aio->data,
-                                .aio_nbytes	= aio->len,
-                                .aio_offset	= aio->offset,
+                                .aio_fildes	= fd,
+                                .aio_buf	= (unsigned long) buf,
+                                .aio_nbytes	= len,
+                                .aio_offset	= offset,
                                 .aio_reserved1	= 0,
                                 .aio_reserved2	= 0,
                                 .aio_reserved3	= 0 });
 
-        switch(aio->type){
+        switch(type){
         case AIO_READ:
                 iocb.aio_lio_opcode = IOCB_CMD_PREAD;
+                err = io_submit(ctx, 1, &iocbp);
                 break;
         case AIO_WRITE:
                 iocb.aio_lio_opcode = IOCB_CMD_PWRITE;
+                err = io_submit(ctx, 1, &iocbp);
                 break;
         case AIO_MMAP:
                 iocb.aio_lio_opcode = IOCB_CMD_PREAD;
                 iocb.aio_buf = (unsigned long) &c;
                 iocb.aio_nbytes = sizeof(c);
+                err = io_submit(ctx, 1, &iocbp);
                 break;
         default:
-                printk("Bogus op in do_aio - %d\n", aio->type);
+                printk("Bogus op in do_aio - %d\n", type);
                 err = -EINVAL;
-                goto out;
+                break;
         }
 
-        err = io_submit(ctx, 1, &iocbp);
         if(err > 0)
                 err = 0;
 	else
 		err = -errno;
 
- out:
         return err;
 }
 
@@ -129,9 +117,8 @@ static aio_context_t ctx = 0;
 static int aio_thread(void *arg)
 {
         struct aio_thread_reply reply;
-        struct aio_context *aio;
         struct io_event event;
-        int err, n;
+        int err, n, reply_fd;
 
         signal(SIGWINCH, SIG_IGN);
 
@@ -144,22 +131,14 @@ static int aio_thread(void *arg)
                                "errno = %d\n", errno);
                 }
                 else {
-			/* This is safe as we've just a pointer here. */
-			aio = (struct aio_context *) (long) event.data;
-			if(update_aio(aio, event.res)){
-				do_aio(ctx, aio);
-				continue;
-			}
-
                         reply = ((struct aio_thread_reply)
-				{ .data = aio,
-				  .err	= aio->len });
-			err = os_write_file(aio->reply_fd, &reply,
-					    sizeof(reply));
+				 { .data = (void *) (long) event.data,
+				   .err	= event.res });
+			reply_fd = ((struct aio_context *) reply.data)->reply_fd;
+			err = os_write_file(reply_fd, &reply, sizeof(reply));
                         if(err != sizeof(reply))
-				printk("aio_thread - write failed, "
-				       "fd = %d, err = %d\n", aio->reply_fd,
-				       -err);
+				printk("aio_thread - write failed, fd = %d, "
+                                       "err = %d\n", aio_req_fd_r, -err);
                 }
         }
         return 0;
@@ -167,35 +146,35 @@ static int aio_thread(void *arg)
 
 #endif
 
-static int do_not_aio(struct aio_context *aio)
+static int do_not_aio(struct aio_thread_req *req)
 {
         char c;
         int err;
 
-        switch(aio->type){
+        switch(req->type){
         case AIO_READ:
-                err = os_seek_file(aio->fd, aio->offset);
+                err = os_seek_file(req->io_fd, req->offset);
                 if(err)
                         goto out;
 
-                err = os_read_file(aio->fd, aio->data, aio->len);
+                err = os_read_file(req->io_fd, req->buf, req->len);
                 break;
         case AIO_WRITE:
-                err = os_seek_file(aio->fd, aio->offset);
+                err = os_seek_file(req->io_fd, req->offset);
                 if(err)
                         goto out;
 
-                err = os_write_file(aio->fd, aio->data, aio->len);
+                err = os_write_file(req->io_fd, req->buf, req->len);
                 break;
         case AIO_MMAP:
-                err = os_seek_file(aio->fd, aio->offset);
+                err = os_seek_file(req->io_fd, req->offset);
                 if(err)
                         goto out;
 
-                err = os_read_file(aio->fd, &c, sizeof(c));
+                err = os_read_file(req->io_fd, &c, sizeof(c));
                 break;
         default:
-                printk("do_not_aio - bad request type : %d\n", aio->type);
+                printk("do_not_aio - bad request type : %d\n", req->type);
                 err = -EINVAL;
                 break;
         }
@@ -206,14 +185,14 @@ static int do_not_aio(struct aio_context *aio)
 
 static int not_aio_thread(void *arg)
 {
-        struct aio_context *aio;
+        struct aio_thread_req req;
         struct aio_thread_reply reply;
         int err;
 
         signal(SIGWINCH, SIG_IGN);
         while(1){
-                err = os_read_file(aio_req_fd_r, &aio, sizeof(aio));
-                if(err != sizeof(aio)){
+                err = os_read_file(aio_req_fd_r, &req, sizeof(req));
+                if(err != sizeof(req)){
                         if(err < 0)
                                 printk("not_aio_thread - read failed, "
                                        "fd = %d, err = %d\n", aio_req_fd_r,
@@ -224,34 +203,17 @@ static int not_aio_thread(void *arg)
                         }
                         continue;
                 }
- again:
-                err = do_not_aio(aio);
-
-                if(update_aio(aio, err))
-                        goto again;
-
-                reply = ((struct aio_thread_reply) { .data 	= aio,
-                                                     .err	= aio->len });
-                err = os_write_file(aio->reply_fd, &reply, sizeof(reply));
+                err = do_not_aio(&req);
+                reply = ((struct aio_thread_reply) { .data 	= req.aio,
+                                                     .err	= err });
+                err = os_write_file(req.aio->reply_fd, &reply, sizeof(reply));
                 if(err != sizeof(reply))
                         printk("not_aio_thread - write failed, fd = %d, "
                                "err = %d\n", aio_req_fd_r, -err);
         }
 }
 
-static int submit_aio_24(struct aio_context *aio)
-{
-        int err;
-
-        err = os_write_file(aio_req_fd_w, &aio, sizeof(aio));
-        if(err == sizeof(aio))
-                err = 0;
-
-        return err;
-}
-
 static int aio_pid = -1;
-static int (*submit_proc)(struct aio_context *aio);
 
 static int init_aio_24(void)
 {
@@ -283,33 +245,11 @@ static int init_aio_24(void)
 #endif
 	printk("2.6 host AIO support not used - falling back to I/O "
 	       "thread\n");
-
-	submit_proc = submit_aio_24;
-
         return 0;
 }
 
 #ifdef HAVE_AIO_ABI
 #define DEFAULT_24_AIO 0
-static int submit_aio_26(struct aio_context *aio)
-{
-	struct aio_thread_reply reply;
-	int err;
-
-	err = do_aio(ctx, aio);
-	if(err){
-		reply = ((struct aio_thread_reply) { .data = aio,
-					             .err  = err });
-		err = os_write_file(aio->reply_fd, &reply, sizeof(reply));
-		if(err != sizeof(reply))
-			printk("submit_aio_26 - write failed, "
-			       "fd = %d, err = %d\n", aio->reply_fd, -err);
-		else err = 0;
-	}
-
-	return err;
-}
-
 static int init_aio_26(void)
 {
         unsigned long stack;
@@ -330,22 +270,39 @@ static int init_aio_26(void)
         aio_pid = err;
 
 	printk("Using 2.6 host AIO\n");
+        return 0;
+}
+
+static int submit_aio_26(enum aio_type type, int io_fd, char *buf, int len,
+			 unsigned long long offset, struct aio_context *aio)
+{
+        struct aio_thread_reply reply;
+        int err;
 
-	submit_proc = submit_aio_26;
+        err = do_aio(ctx, type, io_fd, buf, len, offset, aio);
+        if(err){
+                reply = ((struct aio_thread_reply) { .data = aio,
+                                                     .err  = err });
+                err = os_write_file(aio->reply_fd, &reply, sizeof(reply));
+                if(err != sizeof(reply))
+                        printk("submit_aio_26 - write failed, "
+                               "fd = %d, err = %d\n", aio->reply_fd, -err);
+                else err = 0;
+        }
 
-        return 0;
+        return err;
 }
 
 #else
 #define DEFAULT_24_AIO 1
-static int submit_aio_26(struct aio_context *aio)
+static int init_aio_26(void)
 {
         return -ENOSYS;
 }
 
-static int init_aio_26(void)
+static int submit_aio_26(enum aio_type type, int io_fd, char *buf, int len,
+			 unsigned long long offset, struct aio_context *aio)
 {
-	submit_proc = submit_aio_26;
         return -ENOSYS;
 }
 #endif
@@ -412,7 +369,33 @@ static void exit_aio(void)
 
 __uml_exitcall(exit_aio);
 
-int submit_aio(struct aio_context *aio)
+static int submit_aio_24(enum aio_type type, int io_fd, char *buf, int len,
+			 unsigned long long offset, struct aio_context *aio)
 {
-	return (*submit_proc)(aio);
+        struct aio_thread_req req = { .type 		= type,
+                                      .io_fd		= io_fd,
+                                      .offset		= offset,
+                                      .buf		= buf,
+                                      .len		= len,
+                                      .aio		= aio,
+        };
+        int err;
+
+        err = os_write_file(aio_req_fd_w, &req, sizeof(req));
+        if(err == sizeof(req))
+                err = 0;
+
+        return err;
+}
+
+int submit_aio(enum aio_type type, int io_fd, char *buf, int len,
+               unsigned long long offset, int reply_fd,
+               struct aio_context *aio)
+{
+        aio->reply_fd = reply_fd;
+        if(aio_24)
+                return submit_aio_24(type, io_fd, buf, len, offset, aio);
+        else {
+                return submit_aio_26(type, io_fd, buf, len, offset, aio);
+        }
 }
diff --git a/arch/um/os-Linux/elf_aux.c b/arch/um/os-Linux/elf_aux.c
index ab33cb3c74e..5a99dd3fbed 100644
--- a/arch/um/os-Linux/elf_aux.c
+++ b/arch/um/os-Linux/elf_aux.c
@@ -12,7 +12,7 @@
 #include "init.h"
 #include "elf_user.h"
 #include "mem_user.h"
-#include <kernel-offsets.h>
+#include <kern_constants.h>
 
 /* Use the one from the kernel - the host may miss it, if having old headers. */
 #if UM_ELF_CLASS == UM_ELFCLASS32
diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c
index 6af83171ca4..b99ab414542 100644
--- a/arch/um/os-Linux/start_up.c
+++ b/arch/um/os-Linux/start_up.c
@@ -143,11 +143,22 @@ static int __init skas0_cmd_param(char *str, int* add)
 	return 0;
 }
 
+/* The two __uml_setup would conflict, without this stupid alias. */
+
+static int __init mode_skas0_cmd_param(char *str, int* add)
+	__attribute__((alias("skas0_cmd_param")));
+
 __uml_setup("skas0", skas0_cmd_param,
 		"skas0\n"
 		"    Disables SKAS3 usage, so that SKAS0 is used, unless \n"
 	        "    you specify mode=tt.\n\n");
 
+__uml_setup("mode=skas0", mode_skas0_cmd_param,
+		"mode=skas0\n"
+		"    Disables SKAS3 usage, so that SKAS0 is used, unless you \n"
+		"    specify mode=tt. Note that this was recently added - on \n"
+		"    older kernels you must use simply \"skas0\".\n\n");
+
 static int force_sysemu_disabled = 0;
 
 static int __init nosysemu_cmd_param(char *str, int* add)
diff --git a/arch/um/os-Linux/sys-i386/registers.c b/arch/um/os-Linux/sys-i386/registers.c
index 3125d320722..aee4812333c 100644
--- a/arch/um/os-Linux/sys-i386/registers.c
+++ b/arch/um/os-Linux/sys-i386/registers.c
@@ -5,6 +5,7 @@
 
 #include <errno.h>
 #include <string.h>
+#include <setjmp.h>
 #include "sysdep/ptrace_user.h"
 #include "sysdep/ptrace.h"
 #include "uml-config.h"
@@ -126,13 +127,11 @@ void get_safe_registers(unsigned long *regs)
 	memcpy(regs, exec_regs, HOST_FRAME_SIZE * sizeof(unsigned long));
 }
 
-/*
- * 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 get_thread_regs(union uml_pt_regs *uml_regs, void *buffer)
+{
+	struct __jmp_buf_tag *jmpbuf = buffer;
+
+	UPT_SET(uml_regs, EIP, jmpbuf->__jmpbuf[JB_PC]);
+	UPT_SET(uml_regs, UESP, jmpbuf->__jmpbuf[JB_SP]);
+	UPT_SET(uml_regs, EBP, jmpbuf->__jmpbuf[JB_BP]);
+}
diff --git a/arch/um/os-Linux/sys-x86_64/registers.c b/arch/um/os-Linux/sys-x86_64/registers.c
index 44438d15c3d..4b638dfb52b 100644
--- a/arch/um/os-Linux/sys-x86_64/registers.c
+++ b/arch/um/os-Linux/sys-x86_64/registers.c
@@ -5,6 +5,7 @@
 
 #include <errno.h>
 #include <string.h>
+#include <setjmp.h>
 #include "ptrace_user.h"
 #include "uml-config.h"
 #include "skas_ptregs.h"
@@ -74,13 +75,11 @@ void get_safe_registers(unsigned long *regs)
 	memcpy(regs, exec_regs, HOST_FRAME_SIZE * sizeof(unsigned long));
 }
 
-/*
- * 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 get_thread_regs(union uml_pt_regs *uml_regs, void *buffer)
+{
+	struct __jmp_buf_tag *jmpbuf = buffer;
+
+	UPT_SET(uml_regs, RIP, jmpbuf->__jmpbuf[JB_PC]);
+	UPT_SET(uml_regs, RSP, jmpbuf->__jmpbuf[JB_RSP]);
+	UPT_SET(uml_regs, RBP, jmpbuf->__jmpbuf[JB_RBP]);
+}
diff --git a/arch/um/os-Linux/util/Makefile b/arch/um/os-Linux/util/Makefile
deleted file mode 100644
index 9778aed0c31..00000000000
--- a/arch/um/os-Linux/util/Makefile
+++ /dev/null
@@ -1,4 +0,0 @@
-hostprogs-y		:= mk_user_constants
-always			:= $(hostprogs-y)
-
-HOSTCFLAGS_mk_user_constants.o := -I$(objtree)/arch/um
diff --git a/arch/um/os-Linux/util/mk_user_constants.c b/arch/um/os-Linux/util/mk_user_constants.c
deleted file mode 100644
index 4838f30eecf..00000000000
--- a/arch/um/os-Linux/util/mk_user_constants.c
+++ /dev/null
@@ -1,23 +0,0 @@
-#include <stdio.h>
-#include <user-offsets.h>
-
-int main(int argc, char **argv)
-{
-  printf("/*\n");
-  printf(" * Generated by mk_user_constants\n");
-  printf(" */\n");
-  printf("\n");
-  printf("#ifndef __UM_USER_CONSTANTS_H\n");
-  printf("#define __UM_USER_CONSTANTS_H\n");
-  printf("\n");
-  /* I'd like to use FRAME_SIZE from ptrace.h here, but that's wrong on
-   * x86_64 (216 vs 168 bytes).  user_regs_struct is the correct size on
-   * both x86_64 and i386.
-   */
-  printf("#define UM_FRAME_SIZE %d\n", __UM_FRAME_SIZE);
-
-  printf("\n");
-  printf("#endif\n");
-
-  return(0);
-}
diff --git a/arch/um/scripts/Makefile.rules b/arch/um/scripts/Makefile.rules
index 59a1291f477..651d9d88b65 100644
--- a/arch/um/scripts/Makefile.rules
+++ b/arch/um/scripts/Makefile.rules
@@ -7,8 +7,8 @@ USER_SINGLE_OBJS := \
 USER_OBJS += $(filter %_user.o,$(obj-y) $(obj-m)  $(USER_SINGLE_OBJS))
 USER_OBJS := $(foreach file,$(USER_OBJS),$(obj)/$(file))
 
-$(USER_OBJS) : c_flags = -Wp,-MD,$(depfile) $(USER_CFLAGS) \
-	$(CFLAGS_$(notdir $@))
+$(USER_OBJS) $(USER_OBJS:.o=.i) $(USER_OBJS:.o=.s) $(USER_OBJS:.o=.lst): \
+	c_flags = -Wp,-MD,$(depfile) $(USER_CFLAGS) $(CFLAGS_$(notdir $@))
 $(USER_OBJS): cmd_checksrc =
 $(USER_OBJS): quiet_cmd_checksrc =
 $(USER_OBJS): cmd_force_checksrc =
diff --git a/arch/um/sys-i386/Makefile b/arch/um/sys-i386/Makefile
index 4ca2a229da4..6dfeb70f695 100644
--- a/arch/um/sys-i386/Makefile
+++ b/arch/um/sys-i386/Makefile
@@ -18,6 +18,4 @@ module.c-dir = kernel
 
 $(obj)/stub_segv.o : _c_flags = $(call unprofile,$(CFLAGS))
 
-subdir- := util
-
 include arch/um/scripts/Makefile.unmap
diff --git a/arch/um/sys-i386/kernel-offsets.c b/arch/um/sys-i386/kernel-offsets.c
index a1070af2bcd..35db8505750 100644
--- a/arch/um/sys-i386/kernel-offsets.c
+++ b/arch/um/sys-i386/kernel-offsets.c
@@ -18,9 +18,9 @@
 
 void foo(void)
 {
-	OFFSET(TASK_DEBUGREGS, task_struct, thread.arch.debugregs);
+	OFFSET(HOST_TASK_DEBUGREGS, task_struct, thread.arch.debugregs);
 #ifdef CONFIG_MODE_TT
-	OFFSET(TASK_EXTERN_PID, task_struct, thread.mode.tt.extern_pid);
+	OFFSET(HOST_TASK_EXTERN_PID, task_struct, thread.mode.tt.extern_pid);
 #endif
 #include <common-offsets.h>
 }
diff --git a/arch/um/sys-i386/sysrq.c b/arch/um/sys-i386/sysrq.c
index e3706d15c4f..d5244f07053 100644
--- a/arch/um/sys-i386/sysrq.c
+++ b/arch/um/sys-i386/sysrq.c
@@ -88,9 +88,7 @@ void show_trace(struct task_struct* task, unsigned long * stack)
 		task = current;
 
 	if (task != current) {
-		//ebp = (unsigned long) KSTK_EBP(task);
-		/* Which one? No actual difference - just coding style.*/
-		ebp = (unsigned long) PT_REGS_EBP(&task->thread.regs);
+		ebp = (unsigned long) KSTK_EBP(task);
 	} else {
 		asm ("movl %%ebp, %0" : "=r" (ebp) : );
 	}
@@ -99,15 +97,6 @@ void show_trace(struct task_struct* task, unsigned long * stack)
 		((unsigned long)stack & (~(THREAD_SIZE - 1)));
 	print_context_stack(context, stack, ebp);
 
-	/*while (((long) stack & (THREAD_SIZE-1)) != 0) {
-		addr = *stack;
-		if (__kernel_text_address(addr)) {
-			printk("%08lx:	[<%08lx>]", (unsigned long) stack, addr);
-			print_symbol(" %s", addr);
-			printk("\n");
-		}
-		stack++;
-	}*/
 	printk("\n");
 }
 
diff --git a/arch/um/sys-i386/user-offsets.c b/arch/um/sys-i386/user-offsets.c
index 3ceaabceb3d..26b68675053 100644
--- a/arch/um/sys-i386/user-offsets.c
+++ b/arch/um/sys-i386/user-offsets.c
@@ -7,47 +7,48 @@
 #define DEFINE(sym, val) \
         asm volatile("\n->" #sym " %0 " #val : : "i" (val))
 
+#define DEFINE_LONGS(sym, val) \
+        asm volatile("\n->" #sym " %0 " #val : : "i" (val/sizeof(unsigned long)))
+
 #define OFFSET(sym, str, mem) \
 	DEFINE(sym, offsetof(struct str, mem));
 
 void foo(void)
 {
-	OFFSET(SC_IP, sigcontext, eip);
-	OFFSET(SC_SP, sigcontext, esp);
-	OFFSET(SC_FS, sigcontext, fs);
-	OFFSET(SC_GS, sigcontext, gs);
-	OFFSET(SC_DS, sigcontext, ds);
-	OFFSET(SC_ES, sigcontext, es);
-	OFFSET(SC_SS, sigcontext, ss);
-	OFFSET(SC_CS, sigcontext, cs);
-	OFFSET(SC_EFLAGS, sigcontext, eflags);
-	OFFSET(SC_EAX, sigcontext, eax);
-	OFFSET(SC_EBX, sigcontext, ebx);
-	OFFSET(SC_ECX, sigcontext, ecx);
-	OFFSET(SC_EDX, sigcontext, edx);
-	OFFSET(SC_EDI, sigcontext, edi);
-	OFFSET(SC_ESI, sigcontext, esi);
-	OFFSET(SC_EBP, sigcontext, ebp);
-	OFFSET(SC_TRAPNO, sigcontext, trapno);
-	OFFSET(SC_ERR, sigcontext, err);
-	OFFSET(SC_CR2, sigcontext, cr2);
-	OFFSET(SC_FPSTATE, sigcontext, fpstate);
-	OFFSET(SC_SIGMASK, sigcontext, oldmask);
-	OFFSET(SC_FP_CW, _fpstate, cw);
-	OFFSET(SC_FP_SW, _fpstate, sw);
-	OFFSET(SC_FP_TAG, _fpstate, tag);
-	OFFSET(SC_FP_IPOFF, _fpstate, ipoff);
-	OFFSET(SC_FP_CSSEL, _fpstate, cssel);
-	OFFSET(SC_FP_DATAOFF, _fpstate, dataoff);
-	OFFSET(SC_FP_DATASEL, _fpstate, datasel);
-	OFFSET(SC_FP_ST, _fpstate, _st);
-	OFFSET(SC_FXSR_ENV, _fpstate, _fxsr_env);
+	OFFSET(HOST_SC_IP, sigcontext, eip);
+	OFFSET(HOST_SC_SP, sigcontext, esp);
+	OFFSET(HOST_SC_FS, sigcontext, fs);
+	OFFSET(HOST_SC_GS, sigcontext, gs);
+	OFFSET(HOST_SC_DS, sigcontext, ds);
+	OFFSET(HOST_SC_ES, sigcontext, es);
+	OFFSET(HOST_SC_SS, sigcontext, ss);
+	OFFSET(HOST_SC_CS, sigcontext, cs);
+	OFFSET(HOST_SC_EFLAGS, sigcontext, eflags);
+	OFFSET(HOST_SC_EAX, sigcontext, eax);
+	OFFSET(HOST_SC_EBX, sigcontext, ebx);
+	OFFSET(HOST_SC_ECX, sigcontext, ecx);
+	OFFSET(HOST_SC_EDX, sigcontext, edx);
+	OFFSET(HOST_SC_EDI, sigcontext, edi);
+	OFFSET(HOST_SC_ESI, sigcontext, esi);
+	OFFSET(HOST_SC_EBP, sigcontext, ebp);
+	OFFSET(HOST_SC_TRAPNO, sigcontext, trapno);
+	OFFSET(HOST_SC_ERR, sigcontext, err);
+	OFFSET(HOST_SC_CR2, sigcontext, cr2);
+	OFFSET(HOST_SC_FPSTATE, sigcontext, fpstate);
+	OFFSET(HOST_SC_SIGMASK, sigcontext, oldmask);
+	OFFSET(HOST_SC_FP_CW, _fpstate, cw);
+	OFFSET(HOST_SC_FP_SW, _fpstate, sw);
+	OFFSET(HOST_SC_FP_TAG, _fpstate, tag);
+	OFFSET(HOST_SC_FP_IPOFF, _fpstate, ipoff);
+	OFFSET(HOST_SC_FP_CSSEL, _fpstate, cssel);
+	OFFSET(HOST_SC_FP_DATAOFF, _fpstate, dataoff);
+	OFFSET(HOST_SC_FP_DATASEL, _fpstate, datasel);
+	OFFSET(HOST_SC_FP_ST, _fpstate, _st);
+	OFFSET(HOST_SC_FXSR_ENV, _fpstate, _fxsr_env);
 
 	DEFINE(HOST_FRAME_SIZE, FRAME_SIZE);
-	DEFINE(HOST_FP_SIZE,
-		sizeof(struct user_i387_struct) / sizeof(unsigned long));
-	DEFINE(HOST_XFP_SIZE,
-	       sizeof(struct user_fxsr_struct) / sizeof(unsigned long));
+	DEFINE_LONGS(HOST_FP_SIZE, sizeof(struct user_i387_struct));
+	DEFINE_LONGS(HOST_XFP_SIZE, sizeof(struct user_fxsr_struct));
 
 	DEFINE(HOST_IP, EIP);
 	DEFINE(HOST_SP, UESP);
@@ -65,5 +66,5 @@ void foo(void)
 	DEFINE(HOST_FS, FS);
 	DEFINE(HOST_ES, ES);
 	DEFINE(HOST_GS, GS);
-	DEFINE(__UM_FRAME_SIZE, sizeof(struct user_regs_struct));
+	DEFINE(UM_FRAME_SIZE, sizeof(struct user_regs_struct));
 }
diff --git a/arch/um/sys-i386/util/Makefile b/arch/um/sys-i386/util/Makefile
deleted file mode 100644
index bf61afd0b04..00000000000
--- a/arch/um/sys-i386/util/Makefile
+++ /dev/null
@@ -1,5 +0,0 @@
-hostprogs-y	:= mk_sc mk_thread
-always		:= $(hostprogs-y)
-
-HOSTCFLAGS_mk_sc.o := -I$(objtree)/arch/um
-HOSTCFLAGS_mk_thread.o := -I$(objtree)/arch/um
diff --git a/arch/um/sys-i386/util/mk_sc.c b/arch/um/sys-i386/util/mk_sc.c
deleted file mode 100644
index 04c0d73433a..00000000000
--- a/arch/um/sys-i386/util/mk_sc.c
+++ /dev/null
@@ -1,51 +0,0 @@
-#include <stdio.h>
-#include <user-offsets.h>
-
-#define SC_OFFSET(name, field) \
-  printf("#define " #name "(sc) *((unsigned long *) &(((char *) (sc))[%d]))\n",\
-	 name)
-
-#define SC_FP_OFFSET(name, field) \
-  printf("#define " #name \
-	 "(sc) *((unsigned long *) &(((char *) (SC_FPSTATE(sc)))[%d]))\n",\
-	 name)
-
-#define SC_FP_OFFSET_PTR(name, field, type) \
-  printf("#define " #name \
-	 "(sc) ((" type " *) &(((char *) (SC_FPSTATE(sc)))[%d]))\n",\
-	 name)
-
-int main(int argc, char **argv)
-{
-  SC_OFFSET(SC_IP, eip);
-  SC_OFFSET(SC_SP, esp);
-  SC_OFFSET(SC_FS, fs);
-  SC_OFFSET(SC_GS, gs);
-  SC_OFFSET(SC_DS, ds);
-  SC_OFFSET(SC_ES, es);
-  SC_OFFSET(SC_SS, ss);
-  SC_OFFSET(SC_CS, cs);
-  SC_OFFSET(SC_EFLAGS, eflags);
-  SC_OFFSET(SC_EAX, eax);
-  SC_OFFSET(SC_EBX, ebx);
-  SC_OFFSET(SC_ECX, ecx);
-  SC_OFFSET(SC_EDX, edx);
-  SC_OFFSET(SC_EDI, edi);
-  SC_OFFSET(SC_ESI, esi);
-  SC_OFFSET(SC_EBP, ebp);
-  SC_OFFSET(SC_TRAPNO, trapno);
-  SC_OFFSET(SC_ERR, err);
-  SC_OFFSET(SC_CR2, cr2);
-  SC_OFFSET(SC_FPSTATE, fpstate);
-  SC_OFFSET(SC_SIGMASK, oldmask);
-  SC_FP_OFFSET(SC_FP_CW, cw);
-  SC_FP_OFFSET(SC_FP_SW, sw);
-  SC_FP_OFFSET(SC_FP_TAG, tag);
-  SC_FP_OFFSET(SC_FP_IPOFF, ipoff);
-  SC_FP_OFFSET(SC_FP_CSSEL, cssel);
-  SC_FP_OFFSET(SC_FP_DATAOFF, dataoff);
-  SC_FP_OFFSET(SC_FP_DATASEL, datasel);
-  SC_FP_OFFSET_PTR(SC_FP_ST, _st, "struct _fpstate");
-  SC_FP_OFFSET_PTR(SC_FXSR_ENV, _fxsr_env, "void");
-  return(0);
-}
diff --git a/arch/um/sys-i386/util/mk_thread.c b/arch/um/sys-i386/util/mk_thread.c
deleted file mode 100644
index 7470d0dda67..00000000000
--- a/arch/um/sys-i386/util/mk_thread.c
+++ /dev/null
@@ -1,22 +0,0 @@
-#include <stdio.h>
-#include <kernel-offsets.h>
-
-int main(int argc, char **argv)
-{
-  printf("/*\n");
-  printf(" * Generated by mk_thread\n");
-  printf(" */\n");
-  printf("\n");
-  printf("#ifndef __UM_THREAD_H\n");
-  printf("#define __UM_THREAD_H\n");
-  printf("\n");
-  printf("#define TASK_DEBUGREGS(task) ((unsigned long *) "
-	 "&(((char *) (task))[%d]))\n", TASK_DEBUGREGS);
-#ifdef TASK_EXTERN_PID
-  printf("#define TASK_EXTERN_PID(task) *((int *) &(((char *) (task))[%d]))\n",
-	 TASK_EXTERN_PID);
-#endif
-  printf("\n");
-  printf("#endif\n");
-  return(0);
-}
diff --git a/arch/um/sys-x86_64/Makefile b/arch/um/sys-x86_64/Makefile
index f0ab574d1e9..06c3633457a 100644
--- a/arch/um/sys-x86_64/Makefile
+++ b/arch/um/sys-x86_64/Makefile
@@ -29,6 +29,4 @@ module.c-dir = kernel
 
 $(obj)/stub_segv.o: _c_flags = $(call unprofile,$(CFLAGS))
 
-subdir- := util
-
 include arch/um/scripts/Makefile.unmap
diff --git a/arch/um/sys-x86_64/kernel-offsets.c b/arch/um/sys-x86_64/kernel-offsets.c
index 998541eade4..bfcb104b846 100644
--- a/arch/um/sys-x86_64/kernel-offsets.c
+++ b/arch/um/sys-x86_64/kernel-offsets.c
@@ -19,7 +19,7 @@
 void foo(void)
 {
 #ifdef CONFIG_MODE_TT
-	OFFSET(TASK_EXTERN_PID, task_struct, thread.mode.tt.extern_pid);
+	OFFSET(HOST_TASK_EXTERN_PID, task_struct, thread.mode.tt.extern_pid);
 #endif
 #include <common-offsets.h>
 }
diff --git a/arch/um/sys-x86_64/stub_segv.c b/arch/um/sys-x86_64/stub_segv.c
index 65a131b362b..d1e53bdf2e8 100644
--- a/arch/um/sys-x86_64/stub_segv.c
+++ b/arch/um/sys-x86_64/stub_segv.c
@@ -10,6 +10,22 @@
 #include "uml-config.h"
 #include "sysdep/sigcontext.h"
 #include "sysdep/faultinfo.h"
+#include <stddef.h>
+
+/* Copied from sys-x86_64/signal.c - Can't find an equivalent definition
+ * in the libc headers anywhere.
+ */
+struct rt_sigframe
+{
+	char *pretcode;
+	struct ucontext uc;
+	struct siginfo info;
+};
+
+/* Copied here from <linux/kernel.h> - we're userspace. */
+#define container_of(ptr, type, member) ({                   \
+	const typeof( ((type *)0)->member ) *__mptr = (ptr); \
+	(type *)( (char *)__mptr - offsetof(type,member) );})
 
 void __attribute__ ((__section__ (".__syscall_stub")))
 stub_segv_handler(int sig)
@@ -17,16 +33,19 @@ stub_segv_handler(int sig)
 	struct ucontext *uc;
 
 	__asm__("movq %%rdx, %0" : "=g" (uc) :);
-        GET_FAULTINFO_FROM_SC(*((struct faultinfo *) UML_CONFIG_STUB_DATA),
-                              &uc->uc_mcontext);
+	GET_FAULTINFO_FROM_SC(*((struct faultinfo *) UML_CONFIG_STUB_DATA),
+			      &uc->uc_mcontext);
 
-	__asm__("movq %0, %%rax ; syscall": : "g" (__NR_getpid));
+	__asm__("movq %0, %%rax ; syscall": : "g" (__NR_getpid));	
 	__asm__("movq %%rax, %%rdi ; movq %0, %%rax ; movq %1, %%rsi ;"
-		"syscall": : "g" (__NR_kill), "g" (SIGUSR1));
-	/* Two popqs to restore the stack to the state just before entering
-	 * the handler, one pops the return address, the other pops the frame
-	 * pointer.
+		"syscall": : "g" (__NR_kill), "g" (SIGUSR1) : 
+		"%rdi", "%rax", "%rsi");
+	/* sys_sigreturn expects that the stack pointer will be 8 bytes into
+	 * the signal frame.  So, we use the ucontext pointer, which we know
+	 * already, to get the signal frame pointer, and add 8 to that.
 	 */
-	__asm__("popq %%rax ; popq %%rax ; movq %0, %%rax ; syscall" : : "g"
-		(__NR_rt_sigreturn));
+	__asm__("movq %0, %%rsp": : 
+		"g" ((unsigned long) container_of(uc, struct rt_sigframe, 
+						  uc) + 8));
+	__asm__("movq %0, %%rax ; syscall" : : "g" (__NR_rt_sigreturn));
 }
diff --git a/arch/um/sys-x86_64/user-offsets.c b/arch/um/sys-x86_64/user-offsets.c
index 513d17ceafd..5a585bfbb8c 100644
--- a/arch/um/sys-x86_64/user-offsets.c
+++ b/arch/um/sys-x86_64/user-offsets.c
@@ -16,71 +16,76 @@ typedef __u32 u32;
 #define DEFINE(sym, val) \
         asm volatile("\n->" #sym " %0 " #val : : "i" (val))
 
+#define DEFINE_LONGS(sym, val) \
+        asm volatile("\n->" #sym " %0 " #val : : "i" (val/sizeof(unsigned long)))
+
 #define OFFSET(sym, str, mem) \
 	DEFINE(sym, offsetof(struct str, mem));
 
 void foo(void)
 {
-	OFFSET(SC_RBX, sigcontext, rbx);
-	OFFSET(SC_RCX, sigcontext, rcx);
-	OFFSET(SC_RDX, sigcontext, rdx);
-	OFFSET(SC_RSI, sigcontext, rsi);
-	OFFSET(SC_RDI, sigcontext, rdi);
-	OFFSET(SC_RBP, sigcontext, rbp);
-	OFFSET(SC_RAX, sigcontext, rax);
-	OFFSET(SC_R8, sigcontext, r8);
-	OFFSET(SC_R9, sigcontext, r9);
-	OFFSET(SC_R10, sigcontext, r10);
-	OFFSET(SC_R11, sigcontext, r11);
-	OFFSET(SC_R12, sigcontext, r12);
-	OFFSET(SC_R13, sigcontext, r13);
-	OFFSET(SC_R14, sigcontext, r14);
-	OFFSET(SC_R15, sigcontext, r15);
-	OFFSET(SC_IP, sigcontext, rip);
-	OFFSET(SC_SP, sigcontext, rsp);
-	OFFSET(SC_CR2, sigcontext, cr2);
-	OFFSET(SC_ERR, sigcontext, err);
-	OFFSET(SC_TRAPNO, sigcontext, trapno);
-	OFFSET(SC_CS, sigcontext, cs);
-	OFFSET(SC_FS, sigcontext, fs);
-	OFFSET(SC_GS, sigcontext, gs);
-	OFFSET(SC_EFLAGS, sigcontext, eflags);
-	OFFSET(SC_SIGMASK, sigcontext, oldmask);
+	OFFSET(HOST_SC_RBX, sigcontext, rbx);
+	OFFSET(HOST_SC_RCX, sigcontext, rcx);
+	OFFSET(HOST_SC_RDX, sigcontext, rdx);
+	OFFSET(HOST_SC_RSI, sigcontext, rsi);
+	OFFSET(HOST_SC_RDI, sigcontext, rdi);
+	OFFSET(HOST_SC_RBP, sigcontext, rbp);
+	OFFSET(HOST_SC_RAX, sigcontext, rax);
+	OFFSET(HOST_SC_R8, sigcontext, r8);
+	OFFSET(HOST_SC_R9, sigcontext, r9);
+	OFFSET(HOST_SC_R10, sigcontext, r10);
+	OFFSET(HOST_SC_R11, sigcontext, r11);
+	OFFSET(HOST_SC_R12, sigcontext, r12);
+	OFFSET(HOST_SC_R13, sigcontext, r13);
+	OFFSET(HOST_SC_R14, sigcontext, r14);
+	OFFSET(HOST_SC_R15, sigcontext, r15);
+	OFFSET(HOST_SC_IP, sigcontext, rip);
+	OFFSET(HOST_SC_SP, sigcontext, rsp);
+	OFFSET(HOST_SC_CR2, sigcontext, cr2);
+	OFFSET(HOST_SC_ERR, sigcontext, err);
+	OFFSET(HOST_SC_TRAPNO, sigcontext, trapno);
+	OFFSET(HOST_SC_CS, sigcontext, cs);
+	OFFSET(HOST_SC_FS, sigcontext, fs);
+	OFFSET(HOST_SC_GS, sigcontext, gs);
+	OFFSET(HOST_SC_EFLAGS, sigcontext, eflags);
+	OFFSET(HOST_SC_SIGMASK, sigcontext, oldmask);
 #if 0
-	OFFSET(SC_ORIG_RAX, sigcontext, orig_rax);
-	OFFSET(SC_DS, sigcontext, ds);
-	OFFSET(SC_ES, sigcontext, es);
-	OFFSET(SC_SS, sigcontext, ss);
+	OFFSET(HOST_SC_ORIG_RAX, sigcontext, orig_rax);
+	OFFSET(HOST_SC_DS, sigcontext, ds);
+	OFFSET(HOST_SC_ES, sigcontext, es);
+	OFFSET(HOST_SC_SS, sigcontext, ss);
 #endif
 
-	DEFINE(HOST_FRAME_SIZE, FRAME_SIZE);
-	DEFINE(HOST_RBX, RBX);
-	DEFINE(HOST_RCX, RCX);
-	DEFINE(HOST_RDI, RDI);
-	DEFINE(HOST_RSI, RSI);
-	DEFINE(HOST_RDX, RDX);
-	DEFINE(HOST_RBP, RBP);
-	DEFINE(HOST_RAX, RAX);
-	DEFINE(HOST_R8, R8);
-	DEFINE(HOST_R9, R9);
-	DEFINE(HOST_R10, R10);
-	DEFINE(HOST_R11, R11);
-	DEFINE(HOST_R12, R12);
-	DEFINE(HOST_R13, R13);
-	DEFINE(HOST_R14, R14);
-	DEFINE(HOST_R15, R15);
-	DEFINE(HOST_ORIG_RAX, ORIG_RAX);
-	DEFINE(HOST_CS, CS);
-	DEFINE(HOST_SS, SS);
-	DEFINE(HOST_EFLAGS, EFLAGS);
+	DEFINE_LONGS(HOST_FRAME_SIZE, FRAME_SIZE);
+	DEFINE(HOST_FP_SIZE, 0);
+	DEFINE(HOST_XFP_SIZE, 0);
+	DEFINE_LONGS(HOST_RBX, RBX);
+	DEFINE_LONGS(HOST_RCX, RCX);
+	DEFINE_LONGS(HOST_RDI, RDI);
+	DEFINE_LONGS(HOST_RSI, RSI);
+	DEFINE_LONGS(HOST_RDX, RDX);
+	DEFINE_LONGS(HOST_RBP, RBP);
+	DEFINE_LONGS(HOST_RAX, RAX);
+	DEFINE_LONGS(HOST_R8, R8);
+	DEFINE_LONGS(HOST_R9, R9);
+	DEFINE_LONGS(HOST_R10, R10);
+	DEFINE_LONGS(HOST_R11, R11);
+	DEFINE_LONGS(HOST_R12, R12);
+	DEFINE_LONGS(HOST_R13, R13);
+	DEFINE_LONGS(HOST_R14, R14);
+	DEFINE_LONGS(HOST_R15, R15);
+	DEFINE_LONGS(HOST_ORIG_RAX, ORIG_RAX);
+	DEFINE_LONGS(HOST_CS, CS);
+	DEFINE_LONGS(HOST_SS, SS);
+	DEFINE_LONGS(HOST_EFLAGS, EFLAGS);
 #if 0
-	DEFINE(HOST_FS, FS);
-	DEFINE(HOST_GS, GS);
-	DEFINE(HOST_DS, DS);
-	DEFINE(HOST_ES, ES);
+	DEFINE_LONGS(HOST_FS, FS);
+	DEFINE_LONGS(HOST_GS, GS);
+	DEFINE_LONGS(HOST_DS, DS);
+	DEFINE_LONGS(HOST_ES, ES);
 #endif
 
-	DEFINE(HOST_IP, RIP);
-	DEFINE(HOST_SP, RSP);
-	DEFINE(__UM_FRAME_SIZE, sizeof(struct user_regs_struct));
+	DEFINE_LONGS(HOST_IP, RIP);
+	DEFINE_LONGS(HOST_SP, RSP);
+	DEFINE(UM_FRAME_SIZE, sizeof(struct user_regs_struct));
 }
diff --git a/arch/um/sys-x86_64/util/Makefile b/arch/um/sys-x86_64/util/Makefile
deleted file mode 100644
index 75b052cfc20..00000000000
--- a/arch/um/sys-x86_64/util/Makefile
+++ /dev/null
@@ -1,8 +0,0 @@
-# Copyright 2003 - 2004 Pathscale, Inc
-# Released under the GPL
-
-hostprogs-y	:= mk_sc mk_thread
-always		:= $(hostprogs-y)
-
-HOSTCFLAGS_mk_sc.o := -I$(objtree)/arch/um
-HOSTCFLAGS_mk_thread.o := -I$(objtree)/arch/um
diff --git a/arch/um/sys-x86_64/util/mk_sc.c b/arch/um/sys-x86_64/util/mk_sc.c
deleted file mode 100644
index 7619bc377c1..00000000000
--- a/arch/um/sys-x86_64/util/mk_sc.c
+++ /dev/null
@@ -1,47 +0,0 @@
-/* Copyright (C) 2003 - 2004 PathScale, Inc
- * Released under the GPL
- */
-
-#include <stdio.h>
-#include <user-offsets.h>
-
-#define SC_OFFSET(name) \
-  printf("#define " #name \
-	 "(sc) *((unsigned long *) &(((char *) (sc))[%d]))\n",\
-	 name)
-
-int main(int argc, char **argv)
-{
-  SC_OFFSET(SC_RBX);
-  SC_OFFSET(SC_RCX);
-  SC_OFFSET(SC_RDX);
-  SC_OFFSET(SC_RSI);
-  SC_OFFSET(SC_RDI);
-  SC_OFFSET(SC_RBP);
-  SC_OFFSET(SC_RAX);
-  SC_OFFSET(SC_R8);
-  SC_OFFSET(SC_R9);
-  SC_OFFSET(SC_R10);
-  SC_OFFSET(SC_R11);
-  SC_OFFSET(SC_R12);
-  SC_OFFSET(SC_R13);
-  SC_OFFSET(SC_R14);
-  SC_OFFSET(SC_R15);
-  SC_OFFSET(SC_IP);
-  SC_OFFSET(SC_SP);
-  SC_OFFSET(SC_CR2);
-  SC_OFFSET(SC_ERR);
-  SC_OFFSET(SC_TRAPNO);
-  SC_OFFSET(SC_CS);
-  SC_OFFSET(SC_FS);
-  SC_OFFSET(SC_GS);
-  SC_OFFSET(SC_EFLAGS);
-  SC_OFFSET(SC_SIGMASK);
-#if 0
-  SC_OFFSET(SC_ORIG_RAX);
-  SC_OFFSET(SC_DS);
-  SC_OFFSET(SC_ES);
-  SC_OFFSET(SC_SS);
-#endif
-  return(0);
-}
diff --git a/arch/um/sys-x86_64/util/mk_thread.c b/arch/um/sys-x86_64/util/mk_thread.c
deleted file mode 100644
index 15517396e9c..00000000000
--- a/arch/um/sys-x86_64/util/mk_thread.c
+++ /dev/null
@@ -1,20 +0,0 @@
-#include <stdio.h>
-#include <kernel-offsets.h>
-
-int main(int argc, char **argv)
-{
-  printf("/*\n");
-  printf(" * Generated by mk_thread\n");
-  printf(" */\n");
-  printf("\n");
-  printf("#ifndef __UM_THREAD_H\n");
-  printf("#define __UM_THREAD_H\n");
-  printf("\n");
-#ifdef TASK_EXTERN_PID
-  printf("#define TASK_EXTERN_PID(task) *((int *) &(((char *) (task))[%d]))\n",
-	 TASK_EXTERN_PID);
-#endif
-  printf("\n");
-  printf("#endif\n");
-  return(0);
-}
diff --git a/arch/um/util/Makefile b/arch/um/util/Makefile
deleted file mode 100644
index 4c7551c2803..00000000000
--- a/arch/um/util/Makefile
+++ /dev/null
@@ -1,5 +0,0 @@
-hostprogs-y		:= mk_task mk_constants
-always			:= $(hostprogs-y)
-
-HOSTCFLAGS_mk_task.o := -I$(objtree)/arch/um
-HOSTCFLAGS_mk_constants.o := -I$(objtree)/arch/um
diff --git a/arch/um/util/mk_constants.c b/arch/um/util/mk_constants.c
deleted file mode 100644
index ab217becc36..00000000000
--- a/arch/um/util/mk_constants.c
+++ /dev/null
@@ -1,32 +0,0 @@
-#include <stdio.h>
-#include <kernel-offsets.h>
-
-#define SHOW_INT(sym) printf("#define %s %d\n", #sym, sym)
-#define SHOW_STR(sym) printf("#define %s %s\n", #sym, sym)
-
-int main(int argc, char **argv)
-{
-  printf("/*\n");
-  printf(" * Generated by mk_constants\n");
-  printf(" */\n");
-  printf("\n");
-  printf("#ifndef __UM_CONSTANTS_H\n");
-  printf("#define __UM_CONSTANTS_H\n");
-  printf("\n");
-
-  SHOW_INT(UM_KERN_PAGE_SIZE);
-
-  SHOW_STR(UM_KERN_EMERG);
-  SHOW_STR(UM_KERN_ALERT);
-  SHOW_STR(UM_KERN_CRIT);
-  SHOW_STR(UM_KERN_ERR);
-  SHOW_STR(UM_KERN_WARNING);
-  SHOW_STR(UM_KERN_NOTICE);
-  SHOW_STR(UM_KERN_INFO);
-  SHOW_STR(UM_KERN_DEBUG);
-
-  SHOW_INT(UM_NSEC_PER_SEC);
-  printf("\n");
-  printf("#endif\n");
-  return(0);
-}
diff --git a/arch/um/util/mk_task.c b/arch/um/util/mk_task.c
deleted file mode 100644
index 36c9606505e..00000000000
--- a/arch/um/util/mk_task.c
+++ /dev/null
@@ -1,30 +0,0 @@
-#include <stdio.h>
-#include <kernel-offsets.h>
-
-void print_ptr(char *name, char *type, int offset)
-{
-  printf("#define %s(task) ((%s *) &(((char *) (task))[%d]))\n", name, type,
-	 offset);
-}
-
-void print(char *name, char *type, int offset)
-{
-  printf("#define %s(task) *((%s *) &(((char *) (task))[%d]))\n", name, type,
-	 offset);
-}
-
-int main(int argc, char **argv)
-{
-  printf("/*\n");
-  printf(" * Generated by mk_task\n");
-  printf(" */\n");
-  printf("\n");
-  printf("#ifndef __TASK_H\n");
-  printf("#define __TASK_H\n");
-  printf("\n");
-  print_ptr("TASK_REGS", "union uml_pt_regs", TASK_REGS);
-  print("TASK_PID", "int", TASK_PID);
-  printf("\n");
-  printf("#endif\n");
-  return(0);
-}