Manual merge with Linus

72 files changed, 1860 insertions, 1161 deletions

diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index f945444df49..684e1f8b275 100644
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -73,7 +73,7 @@ config MODE_SKAS
 	to CONFIG_MODE_TT).  Otherwise, it is safe to say Y.  Disabling this
 	option will shrink the UML binary slightly.
 
-source "arch/um/Kconfig_arch"
+source "arch/um/Kconfig.arch"
 source "mm/Kconfig"
 
 config LD_SCRIPT_STATIC
@@ -196,7 +196,7 @@ config HOST_2G_2G
 config SMP
 	bool "Symmetric multi-processing support (EXPERIMENTAL)"
 	default n
-	depends on MODE_TT && EXPERIMENTAL
+	depends on (MODE_TT && EXPERIMENTAL && !SMP_BROKEN) || (BROKEN && SMP_BROKEN)
 	help
 	This option enables UML SMP support.
 	It is NOT related to having a real SMP box. Not directly, at least.
@@ -279,7 +279,7 @@ source "net/Kconfig"
 
 source "drivers/base/Kconfig"
 
-source "arch/um/Kconfig_char"
+source "arch/um/Kconfig.char"
 
 source "drivers/block/Kconfig"
 
@@ -287,7 +287,7 @@ config NETDEVICES
 	bool
 	default NET
 
-source "arch/um/Kconfig_net"
+source "arch/um/Kconfig.net"
 
 source "drivers/net/Kconfig"
 
@@ -311,7 +311,7 @@ config GENERIC_ISA_DMA
 	depends on SCSI
 	default y
 
-source "arch/um/Kconfig_scsi"
+source "arch/um/Kconfig.scsi"
 
 endmenu
 
diff --git a/arch/um/Kconfig_char b/arch/um/Kconfig.char
index 62d87b71179..62d87b71179 100644
--- a/arch/um/Kconfig_char
+++ b/arch/um/Kconfig.char
diff --git a/arch/um/Kconfig.debug b/arch/um/Kconfig.debug
index bd41e4286d0..5681a8bd370 100644
--- a/arch/um/Kconfig.debug
+++ b/arch/um/Kconfig.debug
@@ -2,6 +2,17 @@ menu "Kernel hacking"
 
 source "lib/Kconfig.debug"
 
+config CMDLINE_ON_HOST
+	bool "Show command line arguments on the host in TT mode"
+	depends on MODE_TT
+	default !DEBUG_INFO
+	help
+	This controls whether arguments in guest processes should be shown on
+	the host's ps output.
+	Enabling this option hinders debugging on some recent GDB versions
+	(because GDB gets "confused" when we do an execvp()). So probably you
+	should disable it.
+
 config PT_PROXY
 	bool "Enable ptrace proxy"
 	depends on XTERM_CHAN && DEBUG_INFO && MODE_TT
diff --git a/arch/um/Kconfig_i386 b/arch/um/Kconfig.i386
index 27c18a8d9d1..8ad156a0049 100644
--- a/arch/um/Kconfig_i386
+++ b/arch/um/Kconfig.i386
@@ -6,6 +6,10 @@ config 64BIT
 	bool
 	default n
 
+config SEMAPHORE_SLEEPERS
+	bool
+	default y
+
 config TOP_ADDR
  	hex
  	default 0xc0000000 if !HOST_2G_2G
diff --git a/arch/um/Kconfig_net b/arch/um/Kconfig.net
index fa2ab2dd78b..14a04ebdeae 100644
--- a/arch/um/Kconfig_net
+++ b/arch/um/Kconfig.net
@@ -34,7 +34,7 @@ config UML_NET_ETHERTAP
         link with the host.
 
         To use this, your host kernel must have support for Ethertap
-        devices.  Also, if your host kernel is 2.4.x, it must have 
+        devices.  Also, if your host kernel is 2.4.x, it must have
         CONFIG_NETLINK_DEV configured as Y or M.
 
         For more information, see
@@ -43,7 +43,7 @@ config UML_NET_ETHERTAP
         networking.
 
         If you'd like to set up an IP network with the host and/or the
-        outside world, say Y to this, the Daemon Transport and/or the 
+        outside world, say Y to this, the Daemon Transport and/or the
         Slip Transport.  You'll need at least one of them, but may choose
         more than one without conflict.  If you don't need UML networking,
         say N.
@@ -78,7 +78,7 @@ config UML_NET_SLIP
 
         The Ethertap Transport is preferred over slip because of its
         limitations.  If you prefer slip, however, say Y here.  Otherwise
-        choose the Multicast transport (to network multiple UMLs on 
+        choose the Multicast transport (to network multiple UMLs on
         multiple hosts), Ethertap (to network with the host and the
         outside world), and/or the Daemon transport (to network multiple
         UMLs on a single host).  You may choose more than one without
@@ -138,7 +138,7 @@ config UML_NET_PCAP
 	depends on UML_NET && EXPERIMENTAL
 	help
 	The pcap transport makes a pcap packet stream on the host look
-	like an ethernet device inside UML.  This is useful for making 
+	like an ethernet device inside UML.  This is useful for making
 	UML act as a network monitor for the host.  You must have libcap
 	installed in order to build the pcap transport into UML.
 
@@ -169,11 +169,11 @@ config UML_NET_SLIRP
         setup string.  The effect of this transport on the UML is similar
         that of a host behind a firewall that masquerades all network
         connections passing through it (but is less secure).
-	
+
         To use this you should first have slirp compiled somewhere
         accessible on the host, and have read its documentation.  If you
         don't need UML networking, say N.
-	
+
         Startup example: "eth0=slirp,FE:FD:01:02:03:04,/usr/local/bin/slirp"
 
 endmenu
diff --git a/arch/um/Kconfig_scsi b/arch/um/Kconfig.scsi
index c291c942b1a..c291c942b1a 100644
--- a/arch/um/Kconfig_scsi
+++ b/arch/um/Kconfig.scsi
diff --git a/arch/um/Kconfig_x86_64 b/arch/um/Kconfig.x86_64
index 735a047c890..bd35e59419c 100644
--- a/arch/um/Kconfig_x86_64
+++ b/arch/um/Kconfig.x86_64
@@ -6,6 +6,10 @@ config 64BIT
 	bool
 	default y
 
+config SEMAPHORE_SLEEPERS
+	bool
+	default y
+
 config TOP_ADDR
  	hex
 	default 0x80000000
@@ -33,3 +37,7 @@ config ARCH_HAS_SC_SIGNALS
 config ARCH_REUSE_HOST_VSYSCALL_AREA
 	bool
 	default n
+
+config SMP_BROKEN
+	bool
+	default y
diff --git a/arch/um/Makefile b/arch/um/Makefile
index f5a83a72aa7..577b8d1cf1a 100644
--- a/arch/um/Makefile
+++ b/arch/um/Makefile
@@ -56,6 +56,7 @@ SYS_DIR		:= $(ARCH_DIR)/include/sysdep-$(SUBARCH)
 
 CFLAGS += $(CFLAGS-y) -D__arch_um__ -DSUBARCH=\"$(SUBARCH)\" \
 	$(ARCH_INCLUDE) $(MODE_INCLUDE) -Dvmap=kernel_vmap
+AFLAGS += $(ARCH_INCLUDE)
 
 USER_CFLAGS := $(patsubst -I%,,$(CFLAGS))
 USER_CFLAGS := $(patsubst -D__KERNEL__,,$(USER_CFLAGS)) $(ARCH_INCLUDE) \
@@ -101,10 +102,10 @@ define archhelp
 endef
 
 ifneq ($(KBUILD_SRC),)
-$(shell mkdir -p $(ARCH_DIR) && ln -fsn $(srctree)/$(ARCH_DIR)/Kconfig_$(SUBARCH) $(ARCH_DIR)/Kconfig_arch)
-CLEAN_FILES += $(ARCH_DIR)/Kconfig_arch
+$(shell mkdir -p $(ARCH_DIR) && ln -fsn $(srctree)/$(ARCH_DIR)/Kconfig.$(SUBARCH) $(ARCH_DIR)/Kconfig.arch)
+CLEAN_FILES += $(ARCH_DIR)/Kconfig.arch
 else
-$(shell cd $(ARCH_DIR) && ln -sf Kconfig_$(SUBARCH) Kconfig_arch)
+$(shell cd $(ARCH_DIR) && ln -sf Kconfig.$(SUBARCH) Kconfig.arch)
 endif
 
 prepare: $(ARCH_SYMLINKS) $(SYS_HEADERS) $(GEN_HEADERS)
@@ -147,7 +148,7 @@ CLEAN_FILES += linux x.i gmon.out $(ARCH_DIR)/include/uml-config.h \
 
 MRPROPER_FILES += $(SYMLINK_HEADERS) $(ARCH_SYMLINKS) \
 	$(addprefix $(ARCH_DIR)/kernel/,$(KERN_SYMLINKS)) $(ARCH_DIR)/os \
-	$(ARCH_DIR)/Kconfig_arch
+	$(ARCH_DIR)/Kconfig.arch
 
 archclean:
 	$(Q)$(MAKE) $(clean)=$(ARCH_DIR)/util
@@ -196,6 +197,22 @@ define filechk_umlconfig
 	sed 's/ CONFIG/ UML_CONFIG/'
 endef
 
+define filechk_gen-asm-offsets
+        (set -e; \
+         echo "#ifndef __ASM_OFFSETS_H__"; \
+         echo "#define __ASM_OFFSETS_H__"; \
+         echo "/*"; \
+         echo " * DO NOT MODIFY."; \
+         echo " *"; \
+         echo " * This file was generated by arch/$(ARCH)/Makefile"; \
+         echo " *"; \
+         echo " */"; \
+         echo ""; \
+         sed -ne "/^->/{s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; s:->::; p;}"; \
+         echo ""; \
+         echo "#endif" )
+endef
+
 $(ARCH_DIR)/include/uml-config.h : include/linux/autoconf.h
 	$(call filechk,umlconfig)
 
diff --git a/arch/um/Makefile-i386 b/arch/um/Makefile-i386
index a777e57dbf8..1ab431a53ac 100644
--- a/arch/um/Makefile-i386
+++ b/arch/um/Makefile-i386
@@ -27,7 +27,7 @@ export LDFLAGS HOSTCFLAGS HOSTLDFLAGS UML_OBJCOPYFLAGS
 endif
 endif
 
-CFLAGS += -U__$(SUBARCH)__ -U$(SUBARCH) $(STUB_CFLAGS)
+CFLAGS += -U__$(SUBARCH)__ -U$(SUBARCH)
 
 ifneq ($(CONFIG_GPROF),y)
 ARCH_CFLAGS += -DUM_FASTCALL
diff --git a/arch/um/Makefile-x86_64 b/arch/um/Makefile-x86_64
index aa2f7174ebc..436abbba409 100644
--- a/arch/um/Makefile-x86_64
+++ b/arch/um/Makefile-x86_64
@@ -6,8 +6,9 @@ START := 0x60000000
 
 #We #undef __x86_64__ for kernelspace, not for userspace where
 #it's needed for headers to work!
-CFLAGS += -U__$(SUBARCH)__ -fno-builtin $(STUB_CFLAGS)
+CFLAGS += -U__$(SUBARCH)__ -fno-builtin
 USER_CFLAGS += -fno-builtin
+CHECKFLAGS  += -m64
 
 ELF_ARCH := i386:x86-64
 ELF_FORMAT := elf64-x86-64
diff --git a/arch/um/drivers/Makefile b/arch/um/drivers/Makefile
index de17d4c6e02..783e18cae09 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_user.o
+ubd-objs := ubd_kern.o
 port-objs := port_kern.o port_user.o
 harddog-objs := harddog_kern.o harddog_user.o
 
diff --git a/arch/um/drivers/chan_user.c b/arch/um/drivers/chan_user.c
index 5d3768156c9..de3bce71aeb 100644
--- a/arch/um/drivers/chan_user.c
+++ b/arch/um/drivers/chan_user.c
@@ -63,7 +63,7 @@ error:
  *
  * SIGWINCH can't be received synchronously, so you have to set up to receive it
  * as a signal.  That being the case, if you are going to wait for it, it is
- * convenient to sit in a pause() and wait for the signal to bounce you out of
+ * convenient to sit in sigsuspend() and wait for the signal to bounce you out of
  * it (see below for how we make sure to exit only on SIGWINCH).
  */
 
@@ -94,18 +94,19 @@ static int winch_thread(void *arg)
 		       "byte, err = %d\n", -count);
 
 	/* We are not using SIG_IGN on purpose, so don't fix it as I thought to
-	 * do! If using SIG_IGN, the pause() call below would not stop on
+	 * do! If using SIG_IGN, the sigsuspend() call below would not stop on
 	 * SIGWINCH. */
 
 	signal(SIGWINCH, winch_handler);
 	sigfillset(&sigs);
-	sigdelset(&sigs, SIGWINCH);
-	/* Block anything else than SIGWINCH. */
+	/* Block all signals possible. */
 	if(sigprocmask(SIG_SETMASK, &sigs, NULL) < 0){
 		printk("winch_thread : sigprocmask failed, errno = %d\n", 
 		       errno);
 		exit(1);
 	}
+	/* In sigsuspend(), block anything else than SIGWINCH. */
+	sigdelset(&sigs, SIGWINCH);
 
 	if(setsid() < 0){
 		printk("winch_thread : setsid failed, errno = %d\n", errno);
@@ -130,7 +131,7 @@ static int winch_thread(void *arg)
 	while(1){
 		/* This will be interrupted by SIGWINCH only, since other signals
 		 * are blocked.*/
-		pause();
+		sigsuspend(&sigs);
 
 		count = os_write_file(pipe_fd, &c, sizeof(c));
 		if(count != sizeof(c))
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 344b24d09a7..e77a38da435 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -35,6 +35,7 @@
 #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"
@@ -53,20 +54,21 @@
 #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 ubd_req op;
+	enum aio_type op;
 	int fds[2];
 	unsigned long offsets[2];
 	unsigned long long offset;
 	unsigned long length;
 	char *buffer;
 	int sectorsize;
-	unsigned long sector_mask;
-	unsigned long long cow_offset;
-	unsigned long bitmap_words[2];
+	int bitmap_offset;
+	long bitmap_start;
+	long bitmap_end;
 	int error;
 };
 
@@ -80,28 +82,31 @@ 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);
+extern void do_io(struct io_thread_req *req, struct request *r,
+		  unsigned long *bitmap);
 
-static inline int ubd_test_bit(__u64 bit, unsigned char *data)
+static inline int ubd_test_bit(__u64 bit, void *data)
 {
+	unsigned char *buffer = data;
 	__u64 n;
 	int bits, off;
 
-	bits = sizeof(data[0]) * 8;
+	bits = sizeof(buffer[0]) * 8;
 	n = bit / bits;
 	off = bit % bits;
-	return((data[n] & (1 << off)) != 0);
+	return((buffer[n] & (1 << off)) != 0);
 }
 
-static inline void ubd_set_bit(__u64 bit, unsigned char *data)
+static inline void ubd_set_bit(__u64 bit, void *data)
 {
+	unsigned char *buffer = data;
 	__u64 n;
 	int bits, off;
 
-	bits = sizeof(data[0]) * 8;
+	bits = sizeof(buffer[0]) * 8;
 	n = bit / bits;
 	off = bit % bits;
-	data[n] |= (1 << off);
+	buffer[n] |= (1 << off);
 }
 /*End stuff from ubd_user.h*/
 
@@ -110,8 +115,6 @@ static inline void ubd_set_bit(__u64 bit, unsigned char *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,
@@ -158,6 +161,8 @@ struct cow {
         int data_offset;
 };
 
+#define MAX_SG 64
+
 struct ubd {
 	char *file;
 	int count;
@@ -168,6 +173,7 @@ struct ubd {
 	int no_cow;
 	struct cow cow;
 	struct platform_device pdev;
+        struct scatterlist sg[MAX_SG];
 };
 
 #define DEFAULT_COW { \
@@ -460,80 +466,113 @@ __uml_help(fakehd,
 );
 
 static void do_ubd_request(request_queue_t * q);
-
-/* Only changed by ubd_init, which is an initcall. */
-int thread_fd = -1;
+static int in_ubd;
 
 /* Changed by ubd_handler, which is serialized because interrupts only
  * happen on CPU 0.
  */
 int intr_count = 0;
 
-/* call ubd_finish if you need to serialize */
-static void __ubd_finish(struct request *req, int error)
+static void ubd_end_request(struct request *req, int bytes, int uptodate)
 {
-	int nsect;
-
-	if(error){
-		end_request(req, 0);
-		return;
+	if (!end_that_request_first(req, uptodate, bytes >> 9)) {
+		add_disk_randomness(req->rq_disk);
+		end_that_request_last(req);
 	}
-	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);
 }
 
-static inline void ubd_finish(struct request *req, int error)
+/* call ubd_finish if you need to serialize */
+static void __ubd_finish(struct request *req, int bytes)
 {
- 	spin_lock(&ubd_io_lock);
-	__ubd_finish(req, error);
-	spin_unlock(&ubd_io_lock);
+	if(bytes < 0){
+		ubd_end_request(req, 0, 0);
+  		return;
+  	}
+
+	ubd_end_request(req, bytes, 1);
 }
 
-/* Called without ubd_io_lock held */
-static void ubd_handler(void)
+static inline void ubd_finish(struct request *req, int bytes)
 {
-	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);
+   	spin_lock(&ubd_io_lock);
+	__ubd_finish(req, bytes);
+  	spin_unlock(&ubd_io_lock);
 }
 
+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)
 {
-	ubd_handler();
-	return(IRQ_HANDLED);
-}
+	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;
+		}
 
-/* Only changed by ubd_init, which is an initcall. */
-static int io_pid = -1;
+                aio = container_of(reply.data, struct ubd_aio, aio);
+                n = reply.err;
 
-void kill_io_thread(void)
-{
-	if(io_pid != -1) 
-		os_kill_process(io_pid, 1);
-}
+		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);
 
-__uml_exitcall(kill_io_thread);
+        do_ubd_request(ubd_queue);
+
+	return(IRQ_HANDLED);
+}
 
 static int ubd_file_size(struct ubd *dev, __u64 *size_out)
 {
@@ -569,7 +608,7 @@ 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,
@@ -668,21 +707,22 @@ static int ubd_add(int n)
 	struct ubd *dev = &ubd_dev[n];
 	int err;
 
+	err = -ENODEV;
 	if(dev->file == NULL)
-		return(-ENODEV);
+		goto out;
 
 	if (ubd_open_dev(dev))
-		return(-ENODEV);
+		goto out;
 
 	err = ubd_file_size(dev, &dev->size);
 	if(err < 0)
-		return(err);
+		goto out_close;
 
 	dev->size = ROUND_BLOCK(dev->size);
 
 	err = ubd_new_disk(MAJOR_NR, dev->size, n, &ubd_gendisk[n]);
 	if(err) 
-		return(err);
+		goto out_close;
  
 	if(fake_major != MAJOR_NR)
 		ubd_new_disk(fake_major, dev->size, n, 
@@ -693,8 +733,11 @@ static int ubd_add(int n)
 	if (fake_ide)
 		make_ide_entries(ubd_gendisk[n]->disk_name);
 
+	err = 0;
+out_close:
 	ubd_close(dev);
-	return 0;
+out:
+	return err;
 }
 
 static int ubd_config(char *str)
@@ -827,6 +870,10 @@ 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;
@@ -837,6 +884,7 @@ 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")];
 
@@ -848,40 +896,12 @@ 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;
@@ -919,105 +939,55 @@ static int ubd_release(struct inode * inode, struct file * file)
 	return(0);
 }
 
-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)
+static void cowify_bitmap(struct io_thread_req *req, unsigned long *bitmap)
 {
-	__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;
-
-		update_bitmap = 1;
-		ubd_set_bit(sector + i, (unsigned char *) bitmap);
-	}
-
-	if(!update_bitmap)
-		return;
-
-	*cow_offset = sector / (sizeof(unsigned long) * 8);
-
-	/* 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;
-}
+        __u64 sector = req->offset / req->sectorsize;
+        int i;
 
-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;
+        for(i = 0; i < req->length / req->sectorsize; i++){
+                if(ubd_test_bit(sector + i, bitmap))
+                        continue;
 
-	if(req->length > (sizeof(req->sector_mask) * 8) << 9)
-		panic("Operation too long");
+                if(req->bitmap_start == -1)
+                        req->bitmap_start = sector + i;
+                req->bitmap_end = sector + i + 1;
 
-	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);
+                ubd_set_bit(sector + i, bitmap);
+        }
 }
 
 /* Called with ubd_io_lock held */
-static int prepare_request(struct request *req, struct io_thread_req *io_req)
+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)
 {
 	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);
-		end_request(req, 0);
+                ubd_end_request(req, 0, 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->sector_mask = 0;
-
-	io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE;
+	io_req->op = (rq_data_dir(req) == READ) ? AIO_READ : AIO_WRITE;
 	io_req->offsets[0] = 0;
 	io_req->offsets[1] = dev->cow.data_offset;
-	io_req->buffer = req->buffer;
+        io_req->buffer = page_address(page) + page_offset;
 	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)
-		cowify_req(io_req, dev->cow.bitmap, dev->cow.bitmap_offset,
-			   dev->cow.bitmap_len);
-
+        if((dev->cow.file != NULL) && (io_req->op == UBD_WRITE))
+                cowify_bitmap(io_req, dev->cow.bitmap);
 	return(0);
 }
 
@@ -1026,30 +996,36 @@ static void do_ubd_request(request_queue_t *q)
 {
 	struct io_thread_req io_req;
 	struct request *req;
-	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);
+	__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);
 		}
 	}
+	in_ubd = 0;
 }
 
 static int ubd_ioctl(struct inode * inode, struct file * file,
@@ -1265,131 +1241,95 @@ int create_cow_file(char *cow_file, char *backing_file, struct openflags flags,
 	return(err);
 }
 
-static int update_bitmap(struct io_thread_req *req)
-{
-	int n;
-
-	if(req->cow_offset == -1)
-		return(0);
-
-	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);
-	}
-
-	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);
-	}
-
-	return(0);
-}
-
-void do_io(struct io_thread_req *req)
+void do_io(struct io_thread_req *req, struct request *r, unsigned long *bitmap)
 {
-	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;
-			}
-		}
+        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;
+                }
 
-		start = end;
-	} while(start < nsectors);
+                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) } );
+        }
 
-	req->error = update_bitmap(req);
-}
+        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++;
+                }
 
-/* Changed in start_io_thread, which is serialized by being called only
- * from ubd_init, which is an initcall.
- */
-int kernel_fd = -1;
+                off = req->offsets[bit] + req->offset +
+                        start * req->sectorsize;
+                len = (end - start) * req->sectorsize;
+                buf = &req->buffer[start * req->sectorsize];
 
-/* Only changed by the io thread */
-int io_count = 0;
+                aio = kmalloc(sizeof(*aio), GFP_KERNEL);
+                if(aio == NULL){
+                        req->error = 1;
+                        return;
+                }
 
-int io_thread(void *arg)
-{
-	struct io_thread_req req;
-	int n;
+                *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;
+                }
 
-	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);
-	}
+                start = end;
+        } while(start < nsectors);
 }
-
-/*
- * 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
new file mode 100644
index 00000000000..83f16877ab0
--- /dev/null
+++ b/arch/um/include/aio.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2004 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#ifndef AIO_H__
+#define AIO_H__
+
+enum aio_type { AIO_READ, AIO_WRITE, AIO_MMAP };
+
+struct aio_thread_reply {
+	void *data;
+	int err;
+};
+
+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);
+
+#endif
diff --git a/arch/um/include/common-offsets.h b/arch/um/include/common-offsets.h
index d705daa2d85..0aa620970ad 100644
--- a/arch/um/include/common-offsets.h
+++ b/arch/um/include/common-offsets.h
@@ -12,3 +12,4 @@ DEFINE_STR(UM_KERN_WARNING, KERN_WARNING);
 DEFINE_STR(UM_KERN_NOTICE, KERN_NOTICE);
 DEFINE_STR(UM_KERN_INFO, KERN_INFO);
 DEFINE_STR(UM_KERN_DEBUG, KERN_DEBUG);
+DEFINE(HOST_ELF_CLASS, ELF_CLASS);
diff --git a/arch/um/include/init.h b/arch/um/include/init.h
index 55c2693f877..cbd79a8d213 100644
--- a/arch/um/include/init.h
+++ b/arch/um/include/init.h
@@ -111,7 +111,15 @@ extern struct uml_param __uml_setup_start, __uml_setup_end;
 
 #ifndef __KERNEL__
 
-#define __initcall(fn) static initcall_t __initcall_##fn __init_call = fn
+#define __define_initcall(level,fn) \
+	static initcall_t __initcall_##fn __attribute_used__ \
+	__attribute__((__section__(".initcall" level ".init"))) = fn
+
+/* Userspace initcalls shouldn't depend on anything in the kernel, so we'll
+ * make them run first.
+ */
+#define __initcall(fn) __define_initcall("1", fn)
+
 #define __exitcall(fn) static exitcall_t __exitcall_##fn __exit_call = fn
 
 #define __init_call __attribute__ ((unused,__section__ (".initcall.init")))
diff --git a/arch/um/include/irq_kern.h b/arch/um/include/irq_kern.h
index 3af52a634c4..c222d56b149 100644
--- a/arch/um/include/irq_kern.h
+++ b/arch/um/include/irq_kern.h
@@ -7,12 +7,15 @@
 #define __IRQ_KERN_H__
 
 #include "linux/interrupt.h"
+#include "asm/ptrace.h"
 
 extern int um_request_irq(unsigned int irq, int fd, int type,
 			  irqreturn_t (*handler)(int, void *,
 						 struct pt_regs *),
 			  unsigned long irqflags,  const char * devname,
 			  void *dev_id);
+extern int init_aio_irq(int irq, char *name,
+			irqreturn_t (*handler)(int, void *, struct pt_regs *));
 
 #endif
 
diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index 881d2988d2d..4c362458052 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -153,6 +153,11 @@ extern int os_file_type(char *file);
 extern int os_file_mode(char *file, struct openflags *mode_out);
 extern int os_lock_file(int fd, int excl);
 
+/* start_up.c */
+extern void os_early_checks(void);
+extern int can_do_skas(void);
+
+/* process.c */
 extern unsigned long os_process_pc(int pid);
 extern int os_process_parent(int pid);
 extern void os_stop_process(int pid);
@@ -161,6 +166,9 @@ extern void os_kill_ptraced_process(int pid, int reap_child);
 extern void os_usr1_process(int pid);
 extern int os_getpid(void);
 extern int os_getpgrp(void);
+extern void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int));
+extern void init_new_thread_signals(int altstack);
+extern int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr);
 
 extern int os_map_memory(void *virt, int fd, unsigned long long off,
 			 unsigned long len, int r, int w, int x);
@@ -170,6 +178,13 @@ extern int os_unmap_memory(void *addr, int len);
 extern void os_flush_stdout(void);
 extern unsigned long long os_usecs(void);
 
+/* tt.c
+ * for tt mode only (will be deleted in future...)
+ */
+extern void forward_pending_sigio(int target);
+extern int start_fork_tramp(void *arg, unsigned long temp_stack,
+			    int clone_flags, int (*tramp)(void *));
+
 #endif
 
 /*
diff --git a/arch/um/include/syscall.h b/arch/um/include/syscall.h
new file mode 100644
index 00000000000..dda1df901a0
--- /dev/null
+++ b/arch/um/include/syscall.h
@@ -0,0 +1,12 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __SYSCALL_USER_H
+#define __SYSCALL_USER_H
+
+extern int record_syscall_start(int syscall);
+extern void record_syscall_end(int index, long result);
+
+#endif
diff --git a/arch/um/include/syscall_user.h b/arch/um/include/syscall_user.h
deleted file mode 100644
index 811d0ec2445..00000000000
--- a/arch/um/include/syscall_user.h
+++ /dev/null
@@ -1,23 +0,0 @@
-/* 
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#ifndef __SYSCALL_USER_H
-#define __SYSCALL_USER_H
-
-extern int record_syscall_start(int syscall);
-extern void record_syscall_end(int index, long result);
-
-#endif
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/include/sysdep-i386/syscalls.h b/arch/um/include/sysdep-i386/syscalls.h
index be0a3e3469e..a0d5b74d373 100644
--- a/arch/um/include/sysdep-i386/syscalls.h
+++ b/arch/um/include/sysdep-i386/syscalls.h
@@ -16,6 +16,8 @@ extern syscall_handler_t sys_rt_sigaction;
 
 extern syscall_handler_t old_mmap_i386;
 
+extern syscall_handler_t *sys_call_table[];
+
 #define EXECUTE_SYSCALL(syscall, regs) \
 	((long (*)(struct syscall_args)) (*sys_call_table[syscall]))(SYSCALL_ARGS(&regs->regs))
 
diff --git a/arch/um/include/sysdep-x86_64/ptrace.h b/arch/um/include/sysdep-x86_64/ptrace.h
index be8acd5efd9..331aa2d1f3f 100644
--- a/arch/um/include/sysdep-x86_64/ptrace.h
+++ b/arch/um/include/sysdep-x86_64/ptrace.h
@@ -227,7 +227,7 @@ struct syscall_args {
                         panic("Bad register in UPT_SET : %d\n", reg);  \
 			break; \
                 } \
-                val; \
+                __upt_val; \
         })
 
 #define UPT_SET_SYSCALL_RETURN(r, res) \
diff --git a/arch/um/include/sysdep-x86_64/syscalls.h b/arch/um/include/sysdep-x86_64/syscalls.h
index 67923cca569..e06f83e80f4 100644
--- a/arch/um/include/sysdep-x86_64/syscalls.h
+++ b/arch/um/include/sysdep-x86_64/syscalls.h
@@ -14,6 +14,8 @@ typedef long syscall_handler_t(void);
 
 extern syscall_handler_t *ia32_sys_call_table[];
 
+extern syscall_handler_t *sys_call_table[];
+
 #define EXECUTE_SYSCALL(syscall, regs) \
 	(((long (*)(long, long, long, long, long, long)) \
 	  (*sys_call_table[syscall]))(UPT_SYSCALL_ARG1(&regs->regs), \
diff --git a/arch/um/include/tlb.h b/arch/um/include/tlb.h
index c6f9628f39b..45d7da6c3b2 100644
--- a/arch/um/include/tlb.h
+++ b/arch/um/include/tlb.h
@@ -9,7 +9,7 @@
 #include "um_mmu.h"
 
 struct host_vm_op {
-	enum { MMAP, MUNMAP, MPROTECT } type;
+	enum { NONE, MMAP, MUNMAP, MPROTECT } type;
 	union {
 		struct {
 			unsigned long addr;
@@ -38,24 +38,10 @@ extern void mprotect_kernel_vm(int w);
 extern void force_flush_all(void);
 extern void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
                              unsigned long end_addr, int force,
-                             void (*do_ops)(union mm_context *,
-                                            struct host_vm_op *, int));
+			     int (*do_ops)(union mm_context *,
+					   struct host_vm_op *, int, int,
+					   void **));
 extern int flush_tlb_kernel_range_common(unsigned long start,
 					 unsigned long end);
 
-extern int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
-		    int r, int w, int x, struct host_vm_op *ops, int index,
-                    int last_filled, union mm_context *mmu,
-                    void (*do_ops)(union mm_context *, struct host_vm_op *,
-                                   int));
-extern int add_munmap(unsigned long addr, unsigned long len,
-		      struct host_vm_op *ops, int index, int last_filled,
-                      union mm_context *mmu,
-                      void (*do_ops)(union mm_context *, struct host_vm_op *,
-                                     int));
-extern int add_mprotect(unsigned long addr, unsigned long len, int r, int w,
-			int x, struct host_vm_op *ops, int index,
-                        int last_filled, union mm_context *mmu,
-                        void (*do_ops)(union mm_context *, struct host_vm_op *,
-                                       int));
 #endif
diff --git a/arch/um/include/um_uaccess.h b/arch/um/include/um_uaccess.h
index 6e348cb6de2..84c0868cd56 100644
--- a/arch/um/include/um_uaccess.h
+++ b/arch/um/include/um_uaccess.h
@@ -20,13 +20,6 @@
 #define access_ok(type, addr, size) \
 	CHOOSE_MODE_PROC(access_ok_tt, access_ok_skas, type, addr, size)
 
-/* this function will go away soon - use access_ok() instead */
-static inline int __deprecated verify_area(int type, const void __user *addr, unsigned long size)
-{
-	return (CHOOSE_MODE_PROC(verify_area_tt, verify_area_skas, type, addr,
-				size));
-}
-
 static inline int copy_from_user(void *to, const void __user *from, int n)
 {
 	return(CHOOSE_MODE_PROC(copy_from_user_tt, copy_from_user_skas, to,
diff --git a/arch/um/include/user_util.h b/arch/um/include/user_util.h
index 7b6a24dfd30..bb505e01d99 100644
--- a/arch/um/include/user_util.h
+++ b/arch/um/include/user_util.h
@@ -54,8 +54,6 @@ extern void stack_protections(unsigned long address);
 extern void task_protections(unsigned long address);
 extern int wait_for_stop(int pid, int sig, int cont_type, void *relay);
 extern void *add_signal_handler(int sig, void (*handler)(int));
-extern int start_fork_tramp(void *arg, unsigned long temp_stack, 
-			    int clone_flags, int (*tramp)(void *));
 extern int linux_main(int argc, char **argv);
 extern void set_cmdline(char *cmd);
 extern void input_cb(void (*proc)(void *), void *arg, int arg_len);
@@ -64,8 +62,6 @@ extern void *um_kmalloc(int size);
 extern int switcheroo(int fd, int prot, void *from, void *to, int size);
 extern void setup_machinename(char *machine_out);
 extern void setup_hostinfo(void);
-extern void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int));
-extern void init_new_thread_signals(int altstack);
 extern void do_exec(int old_pid, int new_pid);
 extern void tracer_panic(char *msg, ...);
 extern char *get_umid(int only_if_set);
@@ -74,16 +70,12 @@ extern int detach(int pid, int sig);
 extern int attach(int pid);
 extern void kill_child_dead(int pid);
 extern int cont(int pid);
-extern void check_ptrace(void);
 extern void check_sigio(void);
-extern int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr);
 extern void write_sigio_workaround(void);
 extern void arch_check_bugs(void);
 extern int cpu_feature(char *what, char *buf, int len);
 extern int arch_handle_signal(int sig, union uml_pt_regs *regs);
 extern int arch_fixup(unsigned long address, void *sc_ptr);
-extern void forward_pending_sigio(int target);
-extern int can_do_skas(void);
 extern void arch_init_thread(void);
 extern int setjmp_wrapper(void (*proc)(void *, void *), ...);
 extern int raw(int fd);
diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile
index a8918e80df9..614b8ebeb0e 100644
--- a/arch/um/kernel/Makefile
+++ b/arch/um/kernel/Makefile
@@ -8,25 +8,24 @@ clean-files :=
 
 obj-y = config.o exec_kern.o exitcode.o \
 	helper.o init_task.o irq.o irq_user.o ksyms.o main.o mem.o mem_user.o \
-	physmem.o process.o process_kern.o ptrace.o reboot.o resource.o \
-	sigio_user.o sigio_kern.o signal_kern.o signal_user.o smp.o \
-	syscall_kern.o sysrq.o tempfile.o time.o time_kern.o \
-	tlb.o trap_kern.o trap_user.o uaccess_user.o um_arch.o umid.o \
-	user_util.o
+	physmem.o process_kern.o ptrace.o reboot.o resource.o sigio_user.o \
+	sigio_kern.o signal_kern.o signal_user.o smp.o syscall_kern.o sysrq.o \
+	tempfile.o time.o time_kern.o tlb.o trap_kern.o trap_user.o \
+	uaccess_user.o um_arch.o umid.o user_util.o
 
 obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o
 obj-$(CONFIG_GPROF)	+= gprof_syms.o
 obj-$(CONFIG_GCOV)	+= gmon_syms.o
 obj-$(CONFIG_TTY_LOG)	+= tty_log.o
-obj-$(CONFIG_SYSCALL_DEBUG) += syscall_user.o
+obj-$(CONFIG_SYSCALL_DEBUG) += syscall.o
 
 obj-$(CONFIG_MODE_TT) += tt/
 obj-$(CONFIG_MODE_SKAS) += skas/
 
 user-objs-$(CONFIG_TTY_LOG) += tty_log.o
 
-USER_OBJS := $(user-objs-y) config.o helper.o main.o process.o tempfile.o \
-	time.o tty_log.o umid.o user_util.o
+USER_OBJS := $(user-objs-y) config.o helper.o main.o tempfile.o time.o \
+	tty_log.o umid.o user_util.o
 
 include arch/um/scripts/Makefile.rules
 
diff --git a/arch/um/kernel/asm-offsets.c b/arch/um/kernel/asm-offsets.c
new file mode 100644
index 00000000000..c13a64a288f
--- /dev/null
+++ b/arch/um/kernel/asm-offsets.c
@@ -0,0 +1 @@
+/* Dummy file to make kbuild happy - unused! */
diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c
index 9f18061ef4c..dcd81497199 100644
--- a/arch/um/kernel/irq.c
+++ b/arch/um/kernel/irq.c
@@ -31,7 +31,7 @@
 #include "kern_util.h"
 #include "irq_user.h"
 #include "irq_kern.h"
-
+#include "os.h"
 
 /*
  * Generic, controller-independent functions:
@@ -168,13 +168,32 @@ void __init init_IRQ(void)
 	}
 }
 
-/*
- * 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:
- */
+int init_aio_irq(int irq, char *name, irqreturn_t (*handler)(int, void *,
+							     struct pt_regs *))
+{
+	int fds[2], err;
+
+	err = os_pipe(fds, 1, 1);
+	if(err){
+		printk("init_aio_irq - os_pipe failed, err = %d\n", -err);
+		goto out;
+	}
+
+	err = um_request_irq(irq, fds[0], IRQ_READ, handler,
+			     SA_INTERRUPT | SA_SAMPLE_RANDOM, name,
+			     (void *) (long) fds[0]);
+	if(err){
+		printk("init_aio_irq - : um_request_irq failed, err = %d\n",
+		       err);
+		goto out_close;
+	}
+
+	err = fds[1];
+	goto out;
+
+ out_close:
+	os_close_file(fds[0]);
+	os_close_file(fds[1]);
+ out:
+	return(err);
+}
diff --git a/arch/um/kernel/ksyms.c b/arch/um/kernel/ksyms.c
index 99439fa15ef..32d3076dd22 100644
--- a/arch/um/kernel/ksyms.c
+++ b/arch/um/kernel/ksyms.c
@@ -114,22 +114,3 @@ extern void FASTCALL( __read_lock_failed(rwlock_t *rw));
 EXPORT_SYMBOL(__read_lock_failed);
 
 #endif
-
-#ifdef CONFIG_HIGHMEM
-EXPORT_SYMBOL(kmap);
-EXPORT_SYMBOL(kunmap);
-EXPORT_SYMBOL(kmap_atomic);
-EXPORT_SYMBOL(kunmap_atomic);
-EXPORT_SYMBOL(kmap_atomic_to_page);
-#endif
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/kernel/main.c b/arch/um/kernel/main.c
index 1e1a87f1c51..d31027f0fe3 100644
--- a/arch/um/kernel/main.c
+++ b/arch/um/kernel/main.c
@@ -97,7 +97,7 @@ int main(int argc, char **argv, char **envp)
 		exit(1);
 	}
 
-#ifdef UML_CONFIG_MODE_TT
+#ifdef UML_CONFIG_CMDLINE_ON_HOST
 	/* Allocate memory for thread command lines */
 	if(argc < 2 || strlen(argv[1]) < THREAD_NAME_LEN - 1){
 
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index 5597bd39e6b..64fa062cc11 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -196,7 +196,7 @@ static void init_highmem(void)
 
 static void __init fixaddr_user_init( void)
 {
-#if CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
+#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
 	long size = FIXADDR_USER_END - FIXADDR_USER_START;
 	pgd_t *pgd;
 	pud_t *pud;
diff --git a/arch/um/kernel/skas/Makefile b/arch/um/kernel/skas/Makefile
index d296d55ade4..db36c7c9594 100644
--- a/arch/um/kernel/skas/Makefile
+++ b/arch/um/kernel/skas/Makefile
@@ -4,7 +4,7 @@
 #
 
 obj-y := clone.o exec_kern.o mem.o mem_user.o mmu.o process.o process_kern.o \
-	syscall_kern.o syscall_user.o tlb.o trap_user.o uaccess.o \
+	syscall.o tlb.o trap_user.o uaccess.o
 
 subdir- := util
 
diff --git a/arch/um/kernel/skas/include/mmu-skas.h b/arch/um/kernel/skas/include/mmu-skas.h
index 278b72f1d9a..09536f81ee4 100644
--- a/arch/um/kernel/skas/include/mmu-skas.h
+++ b/arch/um/kernel/skas/include/mmu-skas.h
@@ -6,11 +6,15 @@
 #ifndef __SKAS_MMU_H
 #define __SKAS_MMU_H
 
+#include "linux/config.h"
 #include "mm_id.h"
 
 struct mmu_context_skas {
 	struct mm_id id;
         unsigned long last_page_table;
+#ifdef CONFIG_3_LEVEL_PGTABLES
+        unsigned long last_pmd;
+#endif
 };
 
 extern void switch_mm_skas(struct mm_id * mm_idp);
diff --git a/arch/um/kernel/skas/include/skas.h b/arch/um/kernel/skas/include/skas.h
index d983ea84254..060934740f9 100644
--- a/arch/um/kernel/skas/include/skas.h
+++ b/arch/um/kernel/skas/include/skas.h
@@ -24,28 +24,26 @@ extern void new_thread_proc(void *stack, void (*handler)(int sig));
 extern void remove_sigstack(void);
 extern void new_thread_handler(int sig);
 extern void handle_syscall(union uml_pt_regs *regs);
-extern int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len,
-               int r, int w, int x, int phys_fd, unsigned long long offset);
-extern int unmap(struct mm_id * mm_idp, void *addr, unsigned long len);
+extern int map(struct mm_id * mm_idp, unsigned long virt,
+	       unsigned long len, int r, int w, int x, int phys_fd,
+	       unsigned long long offset, int done, void **data);
+extern int unmap(struct mm_id * mm_idp, void *addr, unsigned long len,
+		 int done, void **data);
 extern int protect(struct mm_id * mm_idp, unsigned long addr,
-		   unsigned long len, int r, int w, int x);
+		   unsigned long len, int r, int w, int x, int done,
+		   void **data);
 extern void user_signal(int sig, union uml_pt_regs *regs, int pid);
-extern int new_mm(int from);
+extern int new_mm(int from, unsigned long stack);
 extern int start_userspace(unsigned long stub_stack);
 extern int copy_context_skas0(unsigned long stack, int pid);
 extern void get_skas_faultinfo(int pid, struct faultinfo * fi);
 extern long execute_syscall_skas(void *r);
 extern unsigned long current_stub_stack(void);
+extern long run_syscall_stub(struct mm_id * mm_idp,
+                             int syscall, unsigned long *args, long expected,
+                             void **addr, int done);
+extern long syscall_stub_data(struct mm_id * mm_idp,
+                              unsigned long *data, int data_count,
+                              void **addr, void **stub_addr);
 
 #endif
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/kernel/skas/include/uaccess-skas.h b/arch/um/kernel/skas/include/uaccess-skas.h
index cd6c280482c..6ee3f3902e6 100644
--- a/arch/um/kernel/skas/include/uaccess-skas.h
+++ b/arch/um/kernel/skas/include/uaccess-skas.h
@@ -18,18 +18,18 @@
 	  ((unsigned long) (addr) + (size) <= FIXADDR_USER_END) && \
 	  ((unsigned long) (addr) + (size) >= (unsigned long)(addr))))
 
-static inline int verify_area_skas(int type, const void * addr,
+static inline int verify_area_skas(int type, const void __user * addr,
                                    unsigned long size)
 {
 	return(access_ok_skas(type, addr, size) ? 0 : -EFAULT);
 }
 
-extern int copy_from_user_skas(void *to, const void *from, int n);
-extern int copy_to_user_skas(void *to, const void *from, int n);
-extern int strncpy_from_user_skas(char *dst, const char *src, int count);
-extern int __clear_user_skas(void *mem, int len);
-extern int clear_user_skas(void *mem, int len);
-extern int strnlen_user_skas(const void *str, int len);
+extern int copy_from_user_skas(void *to, const void __user *from, int n);
+extern int copy_to_user_skas(void __user *to, const void *from, int n);
+extern int strncpy_from_user_skas(char *dst, const char __user *src, int count);
+extern int __clear_user_skas(void __user *mem, int len);
+extern int clear_user_skas(void __user *mem, int len);
+extern int strnlen_user_skas(const void __user *str, int len);
 
 #endif
 
diff --git a/arch/um/kernel/skas/mem_user.c b/arch/um/kernel/skas/mem_user.c
index b0980ff3bd9..1d89640bd50 100644
--- a/arch/um/kernel/skas/mem_user.c
+++ b/arch/um/kernel/skas/mem_user.c
@@ -5,13 +5,14 @@
 
 #include <signal.h>
 #include <errno.h>
+#include <string.h>
 #include <sys/mman.h>
 #include <sys/wait.h>
 #include <asm/page.h>
 #include <asm/unistd.h>
 #include "mem_user.h"
 #include "mem.h"
-#include "mm_id.h"
+#include "skas.h"
 #include "user.h"
 #include "os.h"
 #include "proc_mm.h"
@@ -23,46 +24,155 @@
 #include "uml-config.h"
 #include "sysdep/ptrace.h"
 #include "sysdep/stub.h"
-#include "skas.h"
 
-extern unsigned long syscall_stub, __syscall_stub_start;
+extern unsigned long batch_syscall_stub, __syscall_stub_start;
 
 extern void wait_stub_done(int pid, int sig, char * fname);
 
-static long run_syscall_stub(struct mm_id * mm_idp, int syscall,
-                             unsigned long *args)
+static inline unsigned long *check_init_stack(struct mm_id * mm_idp,
+					      unsigned long *stack)
+{
+	if(stack == NULL){
+		stack = (unsigned long *) mm_idp->stack + 2;
+		*stack = 0;
+	}
+	return stack;
+}
+
+extern int proc_mm;
+
+int single_count = 0;
+int multi_count = 0;
+int multi_op_count = 0;
+
+static long do_syscall_stub(struct mm_id *mm_idp, void **addr)
 {
+	unsigned long regs[MAX_REG_NR];
+	unsigned long *data;
+	unsigned long *syscall;
+	long ret, offset;
         int n, pid = mm_idp->u.pid;
-        unsigned long regs[MAX_REG_NR];
+
+	if(proc_mm)
+#warning Need to look up userspace_pid by cpu
+		pid = userspace_pid[0];
+
+	multi_count++;
 
         get_safe_registers(regs);
         regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
-                ((unsigned long) &syscall_stub -
+		((unsigned long) &batch_syscall_stub -
                  (unsigned long) &__syscall_stub_start);
-        /* XXX Don't have a define for starting a syscall */
-        regs[REGS_SYSCALL_NR] = syscall;
-        regs[REGS_SYSCALL_ARG1] = args[0];
-        regs[REGS_SYSCALL_ARG2] = args[1];
-        regs[REGS_SYSCALL_ARG3] = args[2];
-        regs[REGS_SYSCALL_ARG4] = args[3];
-        regs[REGS_SYSCALL_ARG5] = args[4];
-        regs[REGS_SYSCALL_ARG6] = args[5];
-        n = ptrace_setregs(pid, regs);
-        if(n < 0){
-                printk("run_syscall_stub : PTRACE_SETREGS failed, "
-                       "errno = %d\n", n);
-                return(n);
+	n = ptrace_setregs(pid, regs);
+	if(n < 0)
+		panic("do_syscall_stub : PTRACE_SETREGS failed, errno = %d\n",
+		      n);
+
+	wait_stub_done(pid, 0, "do_syscall_stub");
+
+	/* When the stub stops, we find the following values on the
+	 * beginning of the stack:
+	 * (long )return_value
+	 * (long )offset to failed sycall-data (0, if no error)
+	 */
+	ret = *((unsigned long *) mm_idp->stack);
+	offset = *((unsigned long *) mm_idp->stack + 1);
+	if (offset) {
+		data = (unsigned long *)(mm_idp->stack +
+					 offset - UML_CONFIG_STUB_DATA);
+		syscall = (unsigned long *)((unsigned long)data + data[0]);
+		printk("do_syscall_stub: syscall %ld failed, return value = "
+		       "0x%lx, expected return value = 0x%lx\n",
+		       syscall[0], ret, syscall[7]);
+		printk("    syscall parameters: "
+		       "0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
+		       syscall[1], syscall[2], syscall[3],
+		       syscall[4], syscall[5], syscall[6]);
+		for(n = 1; n < data[0]/sizeof(long); n++) {
+			if(n == 1)
+				printk("    additional syscall data:");
+			if(n % 4 == 1)
+				printk("\n      ");
+			printk("  0x%lx", data[n]);
+		}
+		if(n > 1)
+			printk("\n");
+	}
+	else ret = 0;
+
+	*addr = check_init_stack(mm_idp, NULL);
+
+	return ret;
+}
+
+long run_syscall_stub(struct mm_id * mm_idp, int syscall,
+		      unsigned long *args, long expected, void **addr,
+ 		      int done)
+{
+ 	unsigned long *stack = check_init_stack(mm_idp, *addr);
+
+	if(done && *addr == NULL)
+		single_count++;
+
+ 	*stack += sizeof(long);
+	stack += *stack / sizeof(long);
+
+        *stack++ = syscall;
+        *stack++ = args[0];
+        *stack++ = args[1];
+        *stack++ = args[2];
+        *stack++ = args[3];
+        *stack++ = args[4];
+        *stack++ = args[5];
+	*stack++ = expected;
+        *stack = 0;
+        multi_op_count++;
+
+        if(!done && ((((unsigned long) stack) & ~PAGE_MASK) <
+		     PAGE_SIZE - 10 * sizeof(long))){
+		*addr = stack;
+                return 0;
         }
 
-        wait_stub_done(pid, 0, "run_syscall_stub");
+	return do_syscall_stub(mm_idp, addr);
+}
+
+long syscall_stub_data(struct mm_id * mm_idp,
+		       unsigned long *data, int data_count,
+		       void **addr, void **stub_addr)
+{
+	unsigned long *stack;
+	int ret = 0;
 
-        return(*((unsigned long *) mm_idp->stack));
+	/* If *addr still is uninitialized, it *must* contain NULL.
+	 * Thus in this case do_syscall_stub correctly won't be called.
+	 */
+	if((((unsigned long) *addr) & ~PAGE_MASK) >=
+	   PAGE_SIZE - (10 + data_count) * sizeof(long)) {
+		ret = do_syscall_stub(mm_idp, addr);
+ 		/* in case of error, don't overwrite data on stack */
+		if(ret)
+			return ret;
+	}
+
+	stack = check_init_stack(mm_idp, *addr);
+	*addr = stack;
+
+	*stack = data_count * sizeof(long);
+
+	memcpy(stack + 1, data, data_count * sizeof(long));
+
+	*stub_addr = (void *)(((unsigned long)(stack + 1) & ~PAGE_MASK) +
+			      UML_CONFIG_STUB_DATA);
+
+	return 0;
 }
 
-int map(struct mm_id *mm_idp, unsigned long virt, unsigned long len,
-        int r, int w, int x, int phys_fd, unsigned long long offset)
+int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len,
+	int r, int w, int x, int phys_fd, unsigned long long offset,
+	int done, void **data)
 {
-        int prot, n;
+        int prot, ret;
 
         prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
                 (x ? PROT_EXEC : 0);
@@ -70,6 +180,7 @@ int map(struct mm_id *mm_idp, unsigned long virt, unsigned long len,
         if(proc_mm){
                 struct proc_mm_op map;
                 int fd = mm_idp->u.mm_fd;
+
                 map = ((struct proc_mm_op) { .op	= MM_MMAP,
                                              .u		=
                                              { .mmap	=
@@ -81,63 +192,61 @@ int map(struct mm_id *mm_idp, unsigned long virt, unsigned long len,
                                                  .fd	= phys_fd,
                                                  .offset= offset
                                                } } } );
-                n = os_write_file(fd, &map, sizeof(map));
-                if(n != sizeof(map))
-                        printk("map : /proc/mm map failed, err = %d\n", -n);
+		ret = os_write_file(fd, &map, sizeof(map));
+		if(ret != sizeof(map))
+			printk("map : /proc/mm map failed, err = %d\n", -ret);
+		else ret = 0;
         }
         else {
-                long res;
                 unsigned long args[] = { virt, len, prot,
                                          MAP_SHARED | MAP_FIXED, phys_fd,
                                          MMAP_OFFSET(offset) };
 
-                res = run_syscall_stub(mm_idp, STUB_MMAP_NR, args);
-                if((void *) res == MAP_FAILED)
-                        printk("mmap stub failed, errno = %d\n", res);
+		ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt,
+				       data, done);
         }
 
-        return 0;
+	return ret;
 }
 
-int unmap(struct mm_id *mm_idp, void *addr, unsigned long len)
+int unmap(struct mm_id * mm_idp, void *addr, unsigned long len, int done,
+	  void **data)
 {
-        int n;
+        int ret;
 
         if(proc_mm){
                 struct proc_mm_op unmap;
                 int fd = mm_idp->u.mm_fd;
+
                 unmap = ((struct proc_mm_op) { .op	= MM_MUNMAP,
                                                .u	=
                                                { .munmap	=
                                                  { .addr	=
                                                    (unsigned long) addr,
                                                    .len		= len } } } );
-                n = os_write_file(fd, &unmap, sizeof(unmap));
-                if(n != sizeof(unmap)) {
-                        if(n < 0)
-                                return(n);
-                        else if(n > 0)
-                                return(-EIO);
-                }
+		ret = os_write_file(fd, &unmap, sizeof(unmap));
+		if(ret != sizeof(unmap))
+			printk("unmap - proc_mm write returned %d\n", ret);
+		else ret = 0;
         }
         else {
-                int res;
                 unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0,
                                          0 };
 
-                res = run_syscall_stub(mm_idp, __NR_munmap, args);
-                if(res < 0)
-                        printk("munmap stub failed, errno = %d\n", res);
+		ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0,
+				       data, done);
+                if(ret < 0)
+                        printk("munmap stub failed, errno = %d\n", ret);
         }
 
-        return(0);
+        return ret;
 }
 
-int protect(struct mm_id *mm_idp, unsigned long addr, unsigned long len,
-	    int r, int w, int x)
+int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
+	    int r, int w, int x, int done, void **data)
 {
         struct proc_mm_op protect;
-        int prot, n;
+        int prot, ret;
 
         prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
                 (x ? PROT_EXEC : 0);
@@ -152,20 +261,19 @@ int protect(struct mm_id *mm_idp, unsigned long addr, unsigned long len,
                                                      .len	= len,
                                                      .prot	= prot } } } );
 
-                n = os_write_file(fd, &protect, sizeof(protect));
-                if(n != sizeof(protect))
-                        panic("protect failed, err = %d", -n);
+                ret = os_write_file(fd, &protect, sizeof(protect));
+                if(ret != sizeof(protect))
+                        printk("protect failed, err = %d", -ret);
+                else ret = 0;
         }
         else {
-                int res;
                 unsigned long args[] = { addr, len, prot, 0, 0, 0 };
 
-                res = run_syscall_stub(mm_idp, __NR_mprotect, args);
-                if(res < 0)
-                        panic("mprotect stub failed, errno = %d\n", res);
+                ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
+                                       data, done);
         }
 
-        return(0);
+        return ret;
 }
 
 void before_mem_skas(unsigned long unused)
diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c
index d232daa42c3..240143b616a 100644
--- a/arch/um/kernel/skas/mmu.c
+++ b/arch/um/kernel/skas/mmu.c
@@ -56,6 +56,9 @@ static int init_stub_pte(struct mm_struct *mm, unsigned long proc,
 	 */
 
         mm->context.skas.last_page_table = pmd_page_kernel(*pmd);
+#ifdef CONFIG_3_LEVEL_PGTABLES
+        mm->context.skas.last_pmd = (unsigned long) __va(pud_val(*pud));
+#endif
 
 	*pte = mk_pte(virt_to_page(kernel), __pgprot(_PAGE_PRESENT));
 	*pte = pte_mkexec(*pte);
@@ -77,23 +80,14 @@ int init_new_context_skas(struct task_struct *task, struct mm_struct *mm)
 	struct mm_struct *cur_mm = current->mm;
 	struct mm_id *cur_mm_id = &cur_mm->context.skas.id;
 	struct mm_id *mm_id = &mm->context.skas.id;
-	unsigned long stack;
-	int from, ret;
+	unsigned long stack = 0;
+	int from, ret = -ENOMEM;
 
-	if(proc_mm){
-		if((cur_mm != NULL) && (cur_mm != &init_mm))
-			from = cur_mm->context.skas.id.u.mm_fd;
-		else from = -1;
+	if(!proc_mm || !ptrace_faultinfo){
+		stack = get_zeroed_page(GFP_KERNEL);
+		if(stack == 0)
+			goto out;
 
-		ret = new_mm(from);
-		if(ret < 0){
-			printk("init_new_context_skas - new_mm failed, "
-			       "errno = %d\n", ret);
-			return ret;
-		}
-		mm_id->u.mm_fd = ret;
-	}
-	else {
 		/* This zeros the entry that pgd_alloc didn't, needed since
 		 * we are about to reinitialize it, and want mm.nr_ptes to
 		 * be accurate.
@@ -103,20 +97,30 @@ int init_new_context_skas(struct task_struct *task, struct mm_struct *mm)
 		ret = init_stub_pte(mm, CONFIG_STUB_CODE,
 				    (unsigned long) &__syscall_stub_start);
 		if(ret)
-			goto out;
-
-		ret = -ENOMEM;
-		stack = get_zeroed_page(GFP_KERNEL);
-		if(stack == 0)
-			goto out;
-		mm_id->stack = stack;
+			goto out_free;
 
 		ret = init_stub_pte(mm, CONFIG_STUB_DATA, stack);
 		if(ret)
 			goto out_free;
 
 		mm->nr_ptes--;
+	}
+	mm_id->stack = stack;
 
+	if(proc_mm){
+		if((cur_mm != NULL) && (cur_mm != &init_mm))
+			from = cur_mm_id->u.mm_fd;
+		else from = -1;
+
+		ret = new_mm(from, stack);
+		if(ret < 0){
+			printk("init_new_context_skas - new_mm failed, "
+			       "errno = %d\n", ret);
+			goto out_free;
+		}
+		mm_id->u.mm_fd = ret;
+	}
+	else {
 		if((cur_mm != NULL) && (cur_mm != &init_mm))
 			mm_id->u.pid = copy_context_skas0(stack,
 							  cur_mm_id->u.pid);
@@ -126,7 +130,8 @@ int init_new_context_skas(struct task_struct *task, struct mm_struct *mm)
 	return 0;
 
  out_free:
-	free_page(mm_id->stack);
+	if(mm_id->stack != 0)
+		free_page(mm_id->stack);
  out:
 	return ret;
 }
@@ -137,9 +142,15 @@ void destroy_context_skas(struct mm_struct *mm)
 
 	if(proc_mm)
 		os_close_file(mmu->id.u.mm_fd);
-	else {
+	else
 		os_kill_ptraced_process(mmu->id.u.pid, 1);
+
+	if(!proc_mm || !ptrace_faultinfo){
 		free_page(mmu->id.stack);
-		free_page(mmu->last_page_table);
+		pte_free_kernel((pte_t *) mmu->last_page_table);
+                dec_page_state(nr_page_table_pages);
+#ifdef CONFIG_3_LEVEL_PGTABLES
+		pmd_free((pmd_t *) mmu->last_pmd);
+#endif
 	}
 }
diff --git a/arch/um/kernel/skas/process.c b/arch/um/kernel/skas/process.c
index f228f8b5419..5cd0e992978 100644
--- a/arch/um/kernel/skas/process.c
+++ b/arch/um/kernel/skas/process.c
@@ -138,6 +138,8 @@ static void handle_trap(int pid, union uml_pt_regs *regs, int local_using_sysemu
 }
 
 extern int __syscall_stub_start;
+int stub_code_fd = -1;
+__u64 stub_code_offset;
 
 static int userspace_tramp(void *stack)
 {
@@ -152,31 +154,31 @@ static int userspace_tramp(void *stack)
 		/* This has a pte, but it can't be mapped in with the usual
 		 * tlb_flush mechanism because this is part of that mechanism
 		 */
-		int fd;
-		__u64 offset;
-
-		fd = phys_mapping(to_phys(&__syscall_stub_start), &offset);
 		addr = mmap64((void *) UML_CONFIG_STUB_CODE, page_size(),
-			      PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset);
+			      PROT_EXEC, MAP_FIXED | MAP_PRIVATE,
+			      stub_code_fd, stub_code_offset);
 		if(addr == MAP_FAILED){
-			printk("mapping mmap stub failed, errno = %d\n",
+			printk("mapping stub code failed, errno = %d\n",
 			       errno);
 			exit(1);
 		}
 
 		if(stack != NULL){
+			int fd;
+			__u64 offset;
+
 			fd = phys_mapping(to_phys(stack), &offset);
 			addr = mmap((void *) UML_CONFIG_STUB_DATA, page_size(),
 				    PROT_READ | PROT_WRITE,
 				    MAP_FIXED | MAP_SHARED, fd, offset);
 			if(addr == MAP_FAILED){
-				printk("mapping segfault stack failed, "
+				printk("mapping stub stack failed, "
 				       "errno = %d\n", errno);
 				exit(1);
 			}
 		}
 	}
-	if(!ptrace_faultinfo && (stack != NULL)){
+	if(!ptrace_faultinfo){
 		unsigned long v = UML_CONFIG_STUB_CODE +
 				  (unsigned long) stub_segv_handler -
 				  (unsigned long) &__syscall_stub_start;
@@ -202,6 +204,10 @@ int start_userspace(unsigned long stub_stack)
 	unsigned long sp;
 	int pid, status, n, flags;
 
+	if ( stub_code_fd == -1 )
+		stub_code_fd = phys_mapping(to_phys(&__syscall_stub_start),
+					    &stub_code_offset);
+
 	stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
 		     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 	if(stack == MAP_FAILED)
@@ -363,6 +369,53 @@ int copy_context_skas0(unsigned long new_stack, int pid)
 	return pid;
 }
 
+/*
+ * This is used only, if proc_mm is available, while PTRACE_FAULTINFO
+ * isn't. Opening /proc/mm creates a new mm_context, which lacks the stub-pages
+ * Thus, we map them using /proc/mm-fd
+ */
+void map_stub_pages(int fd, unsigned long code,
+		    unsigned long data, unsigned long stack)
+{
+	struct proc_mm_op mmop;
+	int n;
+
+	mmop = ((struct proc_mm_op) { .op        = MM_MMAP,
+				      .u         =
+				      { .mmap    =
+					{ .addr    = code,
+					  .len     = PAGE_SIZE,
+					  .prot    = PROT_EXEC,
+					  .flags   = MAP_FIXED | MAP_PRIVATE,
+					  .fd      = stub_code_fd,
+					  .offset  = stub_code_offset
+	} } });
+	n = os_write_file(fd, &mmop, sizeof(mmop));
+	if(n != sizeof(mmop))
+		panic("map_stub_pages : /proc/mm map for code failed, "
+		      "err = %d\n", -n);
+
+	if ( stack ) {
+		__u64 map_offset;
+		int map_fd = phys_mapping(to_phys((void *)stack), &map_offset);
+		mmop = ((struct proc_mm_op)
+				{ .op        = MM_MMAP,
+				  .u         =
+				  { .mmap    =
+				    { .addr    = data,
+				      .len     = PAGE_SIZE,
+				      .prot    = PROT_READ | PROT_WRITE,
+				      .flags   = MAP_FIXED | MAP_SHARED,
+				      .fd      = map_fd,
+				      .offset  = map_offset
+		} } });
+		n = os_write_file(fd, &mmop, sizeof(mmop));
+		if(n != sizeof(mmop))
+			panic("map_stub_pages : /proc/mm map for data failed, "
+			      "err = %d\n", -n);
+	}
+}
+
 void new_thread(void *stack, void **switch_buf_ptr, void **fork_buf_ptr,
 		void (*handler)(int))
 {
diff --git a/arch/um/kernel/skas/process_kern.c b/arch/um/kernel/skas/process_kern.c
index cbabab104ac..3d1b227226e 100644
--- a/arch/um/kernel/skas/process_kern.c
+++ b/arch/um/kernel/skas/process_kern.c
@@ -129,7 +129,9 @@ int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp,
 	return(0);
 }
 
-int new_mm(int from)
+extern void map_stub_pages(int fd, unsigned long code,
+			   unsigned long data, unsigned long stack);
+int new_mm(int from, unsigned long stack)
 {
 	struct proc_mm_op copy;
 	int n, fd;
@@ -148,6 +150,9 @@ int new_mm(int from)
 			       "err = %d\n", -n);
 	}
 
+	if(!ptrace_faultinfo)
+		map_stub_pages(fd, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack);
+
 	return(fd);
 }
 
diff --git a/arch/um/kernel/skas/syscall.c b/arch/um/kernel/skas/syscall.c
new file mode 100644
index 00000000000..51fb94076fc
--- /dev/null
+++ b/arch/um/kernel/skas/syscall.c
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include "linux/sys.h"
+#include "linux/ptrace.h"
+#include "asm/errno.h"
+#include "asm/unistd.h"
+#include "asm/ptrace.h"
+#include "asm/current.h"
+#include "sysdep/syscalls.h"
+#include "kern_util.h"
+#include "syscall.h"
+
+void handle_syscall(union uml_pt_regs *r)
+{
+	struct pt_regs *regs = container_of(r, struct pt_regs, regs);
+	long result;
+	int syscall;
+#ifdef UML_CONFIG_SYSCALL_DEBUG
+  	int index;
+
+  	index = record_syscall_start(UPT_SYSCALL_NR(r));
+#endif
+	syscall_trace(r, 0);
+
+	current->thread.nsyscalls++;
+	nsyscalls++;
+
+	/* This should go in the declaration of syscall, but when I do that,
+	 * strace -f -c bash -c 'ls ; ls' breaks, sometimes not tracing
+	 * children at all, sometimes hanging when bash doesn't see the first
+	 * ls exit.
+	 * The assembly looks functionally the same to me.  This is
+	 *     gcc version 4.0.1 20050727 (Red Hat 4.0.1-5)
+	 * in case it's a compiler bug.
+	 */
+	syscall = UPT_SYSCALL_NR(r);
+	if((syscall >= NR_syscalls) || (syscall < 0))
+		result = -ENOSYS;
+	else result = EXECUTE_SYSCALL(syscall, regs);
+
+	REGS_SET_SYSCALL_RETURN(r->skas.regs, result);
+
+	syscall_trace(r, 1);
+#ifdef UML_CONFIG_SYSCALL_DEBUG
+  	record_syscall_end(index, result);
+#endif
+}
diff --git a/arch/um/kernel/skas/syscall_kern.c b/arch/um/kernel/skas/syscall_kern.c
deleted file mode 100644
index bdf040ce5b8..00000000000
--- a/arch/um/kernel/skas/syscall_kern.c
+++ /dev/null
@@ -1,43 +0,0 @@
-/* 
- * Copyright (C) 2002 - 2003 Jeff Dike (jdike@addtoit.com)
- * Licensed under the GPL
- */
-
-#include "linux/sys.h"
-#include "linux/ptrace.h"
-#include "asm/errno.h"
-#include "asm/unistd.h"
-#include "asm/ptrace.h"
-#include "asm/current.h"
-#include "sysdep/syscalls.h"
-#include "kern_util.h"
-
-extern syscall_handler_t *sys_call_table[];
-
-long execute_syscall_skas(void *r)
-{
-	struct pt_regs *regs = r;
-	long res;
-	int syscall;
-
-	current->thread.nsyscalls++;
-	nsyscalls++;
-	syscall = UPT_SYSCALL_NR(&regs->regs);
-
-	if((syscall >= NR_syscalls) || (syscall < 0))
-		res = -ENOSYS;
-	else res = EXECUTE_SYSCALL(syscall, regs);
-
-	return(res);
-}
-
-/*
- * 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/syscall_user.c b/arch/um/kernel/skas/syscall_user.c
deleted file mode 100644
index 6b066497014..00000000000
--- a/arch/um/kernel/skas/syscall_user.c
+++ /dev/null
@@ -1,44 +0,0 @@
-/* 
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#include <stdlib.h>
-#include <signal.h>
-#include "kern_util.h"
-#include "uml-config.h"
-#include "syscall_user.h"
-#include "sysdep/ptrace.h"
-#include "sysdep/sigcontext.h"
-#include "skas.h"
-
-void handle_syscall(union uml_pt_regs *regs)
-{
-	long result;
-#ifdef UML_CONFIG_SYSCALL_DEBUG
-  	int index;
-
-  	index = record_syscall_start(UPT_SYSCALL_NR(regs));
-#endif
-
-	syscall_trace(regs, 0);
-	result = execute_syscall_skas(regs);
-
-	REGS_SET_SYSCALL_RETURN(regs->skas.regs, result);
-
-	syscall_trace(regs, 1);
-#ifdef UML_CONFIG_SYSCALL_DEBUG
-  	record_syscall_end(index, result);
-#endif
-}
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/kernel/skas/tlb.c b/arch/um/kernel/skas/tlb.c
index 6230999c672..6e84963dfc2 100644
--- a/arch/um/kernel/skas/tlb.c
+++ b/arch/um/kernel/skas/tlb.c
@@ -18,33 +18,39 @@
 #include "os.h"
 #include "tlb.h"
 
-static void do_ops(union mm_context *mmu, struct host_vm_op *ops, int last)
+static int do_ops(union mm_context *mmu, struct host_vm_op *ops, int last,
+		  int finished, void **flush)
 {
 	struct host_vm_op *op;
-	int i;
+        int i, ret = 0;
 
-	for(i = 0; i <= last; i++){
+        for(i = 0; i <= last && !ret; i++){
 		op = &ops[i];
 		switch(op->type){
 		case MMAP:
-                        map(&mmu->skas.id, op->u.mmap.addr, op->u.mmap.len,
-			    op->u.mmap.r, op->u.mmap.w, op->u.mmap.x,
-			    op->u.mmap.fd, op->u.mmap.offset);
+			ret = map(&mmu->skas.id, op->u.mmap.addr,
+				  op->u.mmap.len, op->u.mmap.r, op->u.mmap.w,
+				  op->u.mmap.x, op->u.mmap.fd,
+				  op->u.mmap.offset, finished, flush);
 			break;
 		case MUNMAP:
-                        unmap(&mmu->skas.id, (void *) op->u.munmap.addr,
-			      op->u.munmap.len);
+			ret = unmap(&mmu->skas.id,
+				    (void *) op->u.munmap.addr,
+				    op->u.munmap.len, finished, flush);
 			break;
 		case MPROTECT:
-                        protect(&mmu->skas.id, op->u.mprotect.addr,
-                                op->u.mprotect.len, op->u.mprotect.r,
-                                op->u.mprotect.w, op->u.mprotect.x);
+			ret = protect(&mmu->skas.id, op->u.mprotect.addr,
+				      op->u.mprotect.len, op->u.mprotect.r,
+				      op->u.mprotect.w, op->u.mprotect.x,
+				      finished, flush);
 			break;
 		default:
 			printk("Unknown op type %d in do_ops\n", op->type);
 			break;
 		}
 	}
+
+	return ret;
 }
 
 extern int proc_mm;
diff --git a/arch/um/kernel/syscall.c b/arch/um/kernel/syscall.c
new file mode 100644
index 00000000000..1429c131879
--- /dev/null
+++ b/arch/um/kernel/syscall.c
@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include "kern_util.h"
+#include "syscall.h"
+#include "os.h"
+
+struct {
+	int syscall;
+	int pid;
+	long result;
+	unsigned long long start;
+	unsigned long long end;
+} syscall_record[1024];
+
+int record_syscall_start(int syscall)
+{
+	int max, index;
+
+	max = sizeof(syscall_record)/sizeof(syscall_record[0]);
+	index = next_syscall_index(max);
+
+	syscall_record[index].syscall = syscall;
+	syscall_record[index].pid = current_pid();
+	syscall_record[index].result = 0xdeadbeef;
+	syscall_record[index].start = os_usecs();
+	return(index);
+}
+
+void record_syscall_end(int index, long result)
+{
+	syscall_record[index].result = result;
+	syscall_record[index].end = os_usecs();
+}
diff --git a/arch/um/kernel/syscall_user.c b/arch/um/kernel/syscall_user.c
deleted file mode 100644
index 01b711e00a8..00000000000
--- a/arch/um/kernel/syscall_user.c
+++ /dev/null
@@ -1,48 +0,0 @@
-/* 
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#include <stdlib.h>
-#include <sys/time.h>
-#include "kern_util.h"
-#include "syscall_user.h"
-
-struct {
-	int syscall;
-	int pid;
-	long result;
-	struct timeval start;
-	struct timeval end;
-} syscall_record[1024];
-
-int record_syscall_start(int syscall)
-{
-	int max, index;
-
-	max = sizeof(syscall_record)/sizeof(syscall_record[0]);
-	index = next_syscall_index(max);
-
-	syscall_record[index].syscall = syscall;
-	syscall_record[index].pid = current_pid();
-	syscall_record[index].result = 0xdeadbeef;
-	gettimeofday(&syscall_record[index].start, NULL);
-	return(index);
-}
-
-void record_syscall_end(int index, long result)
-{
-	syscall_record[index].result = result;
-	gettimeofday(&syscall_record[index].end, NULL);
-}
-
-/*
- * 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/tlb.c b/arch/um/kernel/tlb.c
index 83ec8d4747f..80ed6188e8a 100644
--- a/arch/um/kernel/tlb.c
+++ b/arch/um/kernel/tlb.c
@@ -15,12 +15,118 @@
 #include "mem_user.h"
 #include "os.h"
 
+static int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
+ 		    int r, int w, int x, struct host_vm_op *ops, int *index,
+		    int last_filled, union mm_context *mmu, void **flush,
+		    int (*do_ops)(union mm_context *, struct host_vm_op *,
+				  int, int, void **))
+{
+        __u64 offset;
+	struct host_vm_op *last;
+	int fd, ret = 0;
+
+	fd = phys_mapping(phys, &offset);
+	if(*index != -1){
+		last = &ops[*index];
+		if((last->type == MMAP) &&
+		   (last->u.mmap.addr + last->u.mmap.len == virt) &&
+		   (last->u.mmap.r == r) && (last->u.mmap.w == w) &&
+		   (last->u.mmap.x == x) && (last->u.mmap.fd == fd) &&
+		   (last->u.mmap.offset + last->u.mmap.len == offset)){
+			last->u.mmap.len += len;
+			return 0;
+		}
+	}
+
+	if(*index == last_filled){
+		ret = (*do_ops)(mmu, ops, last_filled, 0, flush);
+		*index = -1;
+	}
+
+	ops[++*index] = ((struct host_vm_op) { .type	= MMAP,
+			     			.u = { .mmap = {
+						       .addr	= virt,
+						       .len	= len,
+						       .r	= r,
+						       .w	= w,
+						       .x	= x,
+						       .fd	= fd,
+						       .offset	= offset }
+			   } });
+	return ret;
+}
+
+static int add_munmap(unsigned long addr, unsigned long len,
+		      struct host_vm_op *ops, int *index, int last_filled,
+		      union mm_context *mmu, void **flush,
+		      int (*do_ops)(union mm_context *, struct host_vm_op *,
+				    int, int, void **))
+{
+	struct host_vm_op *last;
+	int ret = 0;
+
+	if(*index != -1){
+		last = &ops[*index];
+		if((last->type == MUNMAP) &&
+		   (last->u.munmap.addr + last->u.mmap.len == addr)){
+			last->u.munmap.len += len;
+			return 0;
+		}
+	}
+
+	if(*index == last_filled){
+		ret = (*do_ops)(mmu, ops, last_filled, 0, flush);
+		*index = -1;
+	}
+
+	ops[++*index] = ((struct host_vm_op) { .type	= MUNMAP,
+			     		       .u = { .munmap = {
+						        .addr	= addr,
+							.len	= len } } });
+	return ret;
+}
+
+static int add_mprotect(unsigned long addr, unsigned long len, int r, int w,
+			int x, struct host_vm_op *ops, int *index,
+			int last_filled, union mm_context *mmu, void **flush,
+ 			int (*do_ops)(union mm_context *, struct host_vm_op *,
+				      int, int, void **))
+{
+	struct host_vm_op *last;
+	int ret = 0;
+
+	if(*index != -1){
+		last = &ops[*index];
+		if((last->type == MPROTECT) &&
+		   (last->u.mprotect.addr + last->u.mprotect.len == addr) &&
+		   (last->u.mprotect.r == r) && (last->u.mprotect.w == w) &&
+		   (last->u.mprotect.x == x)){
+			last->u.mprotect.len += len;
+			return 0;
+		}
+	}
+
+	if(*index == last_filled){
+		ret = (*do_ops)(mmu, ops, last_filled, 0, flush);
+		*index = -1;
+	}
+
+	ops[++*index] = ((struct host_vm_op) { .type	= MPROTECT,
+			     		       .u = { .mprotect = {
+						       .addr	= addr,
+						       .len	= len,
+						       .r	= r,
+						       .w	= w,
+						       .x	= x } } });
+	return ret;
+}
+
 #define ADD_ROUND(n, inc) (((n) + (inc)) & ~((inc) - 1))
 
 void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
                       unsigned long end_addr, int force,
-                      void (*do_ops)(union mm_context *, struct host_vm_op *,
-                                     int))
+		      int (*do_ops)(union mm_context *, struct host_vm_op *,
+				    int, int, void **))
 {
         pgd_t *npgd;
         pud_t *npud;
@@ -29,21 +135,24 @@ void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
         union mm_context *mmu = &mm->context;
         unsigned long addr, end;
         int r, w, x;
-        struct host_vm_op ops[16];
+        struct host_vm_op ops[1];
+        void *flush = NULL;
         int op_index = -1, last_op = sizeof(ops) / sizeof(ops[0]) - 1;
+        int ret = 0;
 
         if(mm == NULL) return;
 
-        for(addr = start_addr; addr < end_addr;){
+        ops[0].type = NONE;
+        for(addr = start_addr; addr < end_addr && !ret;){
                 npgd = pgd_offset(mm, addr);
                 if(!pgd_present(*npgd)){
                         end = ADD_ROUND(addr, PGDIR_SIZE);
                         if(end > end_addr)
                                 end = end_addr;
                         if(force || pgd_newpage(*npgd)){
-                                op_index = add_munmap(addr, end - addr, ops,
-                                                      op_index, last_op, mmu,
-                                                      do_ops);
+                                ret = add_munmap(addr, end - addr, ops,
+                                                 &op_index, last_op, mmu,
+                                                 &flush, do_ops);
                                 pgd_mkuptodate(*npgd);
                         }
                         addr = end;
@@ -56,9 +165,9 @@ void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
                         if(end > end_addr)
                                 end = end_addr;
                         if(force || pud_newpage(*npud)){
-                                op_index = add_munmap(addr, end - addr, ops,
-                                                      op_index, last_op, mmu,
-                                                      do_ops);
+                                ret = add_munmap(addr, end - addr, ops,
+                                                 &op_index, last_op, mmu,
+                                                 &flush, do_ops);
                                 pud_mkuptodate(*npud);
                         }
                         addr = end;
@@ -71,9 +180,9 @@ void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
                         if(end > end_addr)
                                 end = end_addr;
                         if(force || pmd_newpage(*npmd)){
-                                op_index = add_munmap(addr, end - addr, ops,
-                                                      op_index, last_op, mmu,
-                                                      do_ops);
+                                ret = add_munmap(addr, end - addr, ops,
+                                                 &op_index, last_op, mmu,
+                                                 &flush, do_ops);
                                 pmd_mkuptodate(*npmd);
                         }
                         addr = end;
@@ -92,24 +201,32 @@ void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
                 }
                 if(force || pte_newpage(*npte)){
                         if(pte_present(*npte))
-                                op_index = add_mmap(addr,
-                                                    pte_val(*npte) & PAGE_MASK,
-                                                    PAGE_SIZE, r, w, x, ops,
-                                                    op_index, last_op, mmu,
-                                                    do_ops);
-                        else op_index = add_munmap(addr, PAGE_SIZE, ops,
-                                                   op_index, last_op, mmu,
-                                                   do_ops);
+			  ret = add_mmap(addr,
+					 pte_val(*npte) & PAGE_MASK,
+					 PAGE_SIZE, r, w, x, ops,
+					 &op_index, last_op, mmu,
+					 &flush, do_ops);
+			else ret = add_munmap(addr, PAGE_SIZE, ops,
+					      &op_index, last_op, mmu,
+					      &flush, do_ops);
                 }
                 else if(pte_newprot(*npte))
-                        op_index = add_mprotect(addr, PAGE_SIZE, r, w, x, ops,
-                                                op_index, last_op, mmu,
-                                                do_ops);
+			ret = add_mprotect(addr, PAGE_SIZE, r, w, x, ops,
+					   &op_index, last_op, mmu,
+					   &flush, do_ops);
 
                 *npte = pte_mkuptodate(*npte);
                 addr += PAGE_SIZE;
         }
-        (*do_ops)(mmu, ops, op_index);
+
+	if(!ret)
+		ret = (*do_ops)(mmu, ops, op_index, 1, &flush);
+
+	/* This is not an else because ret is modified above */
+	if(ret) {
+		printk("fix_range_common: failed, killing current process\n");
+		force_sig(SIGKILL, current);
+	}
 }
 
 int flush_tlb_kernel_range_common(unsigned long start, unsigned long end)
@@ -226,106 +343,6 @@ pte_t *addr_pte(struct task_struct *task, unsigned long addr)
         return(pte_offset_map(pmd, addr));
 }
 
-int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
-             int r, int w, int x, struct host_vm_op *ops, int index,
-             int last_filled, union mm_context *mmu,
-             void (*do_ops)(union mm_context *, struct host_vm_op *, int))
-{
-        __u64 offset;
-	struct host_vm_op *last;
-	int fd;
-
-	fd = phys_mapping(phys, &offset);
-	if(index != -1){
-		last = &ops[index];
-		if((last->type == MMAP) &&
-		   (last->u.mmap.addr + last->u.mmap.len == virt) &&
-		   (last->u.mmap.r == r) && (last->u.mmap.w == w) &&
-		   (last->u.mmap.x == x) && (last->u.mmap.fd == fd) &&
-		   (last->u.mmap.offset + last->u.mmap.len == offset)){
-			last->u.mmap.len += len;
-			return(index);
-		}
-	}
-
-	if(index == last_filled){
-		(*do_ops)(mmu, ops, last_filled);
-		index = -1;
-	}
-
-	ops[++index] = ((struct host_vm_op) { .type	= MMAP,
-					      .u = { .mmap = {
-						      .addr	= virt,
-						      .len	= len,
-						      .r	= r,
-						      .w	= w,
-						      .x	= x,
-						      .fd	= fd,
-						      .offset	= offset }
-					      } });
-	return(index);
-}
-
-int add_munmap(unsigned long addr, unsigned long len, struct host_vm_op *ops,
-	       int index, int last_filled, union mm_context *mmu,
-	       void (*do_ops)(union mm_context *, struct host_vm_op *, int))
-{
-	struct host_vm_op *last;
-
-	if(index != -1){
-		last = &ops[index];
-		if((last->type == MUNMAP) &&
-		   (last->u.munmap.addr + last->u.mmap.len == addr)){
-			last->u.munmap.len += len;
-			return(index);
-		}
-	}
-
-	if(index == last_filled){
-		(*do_ops)(mmu, ops, last_filled);
-		index = -1;
-	}
-
-	ops[++index] = ((struct host_vm_op) { .type	= MUNMAP,
-					      .u = { .munmap = {
-						      .addr	= addr,
-						      .len	= len } } });
-	return(index);
-}
-
-int add_mprotect(unsigned long addr, unsigned long len, int r, int w, int x,
-                 struct host_vm_op *ops, int index, int last_filled,
-                 union mm_context *mmu,
-                 void (*do_ops)(union mm_context *, struct host_vm_op *, int))
-{
-	struct host_vm_op *last;
-
-	if(index != -1){
-		last = &ops[index];
-		if((last->type == MPROTECT) &&
-		   (last->u.mprotect.addr + last->u.mprotect.len == addr) &&
-		   (last->u.mprotect.r == r) && (last->u.mprotect.w == w) &&
-		   (last->u.mprotect.x == x)){
-			last->u.mprotect.len += len;
-			return(index);
-		}
-	}
-
-	if(index == last_filled){
-		(*do_ops)(mmu, ops, last_filled);
-		index = -1;
-	}
-
-	ops[++index] = ((struct host_vm_op) { .type	= MPROTECT,
-					      .u = { .mprotect = {
-						      .addr	= addr,
-						      .len	= len,
-						      .r	= r,
-						      .w	= w,
-						      .x	= x } } });
-	return(index);
-}
-
 void flush_tlb_page(struct vm_area_struct *vma, unsigned long address)
 {
         address &= PAGE_MASK;
diff --git a/arch/um/kernel/trap_kern.c b/arch/um/kernel/trap_kern.c
index c20aef12059..b5fc89fe9ea 100644
--- a/arch/um/kernel/trap_kern.c
+++ b/arch/um/kernel/trap_kern.c
@@ -26,6 +26,7 @@
 #include "mem.h"
 #include "mem_kern.h"
 
+/* Note this is constrained to return 0, -EFAULT, -EACCESS, -ENOMEM by segv(). */
 int handle_page_fault(unsigned long address, unsigned long ip, 
 		      int is_write, int is_user, int *code_out)
 {
@@ -35,7 +36,6 @@ int handle_page_fault(unsigned long address, unsigned long ip,
 	pud_t *pud;
 	pmd_t *pmd;
 	pte_t *pte;
-	unsigned long page;
 	int err = -EFAULT;
 
 	*code_out = SEGV_MAPERR;
@@ -52,7 +52,7 @@ int handle_page_fault(unsigned long address, unsigned long ip,
 	else if(expand_stack(vma, address)) 
 		goto out;
 
- good_area:
+good_area:
 	*code_out = SEGV_ACCERR;
 	if(is_write && !(vma->vm_flags & VM_WRITE)) 
 		goto out;
@@ -60,9 +60,8 @@ int handle_page_fault(unsigned long address, unsigned long ip,
         if(!(vma->vm_flags & (VM_READ | VM_EXEC)))
                 goto out;
 
-	page = address & PAGE_MASK;
 	do {
- survive:
+survive:
 		switch (handle_mm_fault(mm, vma, address, is_write)){
 		case VM_FAULT_MINOR:
 			current->min_flt++;
@@ -79,16 +78,16 @@ int handle_page_fault(unsigned long address, unsigned long ip,
 		default:
 			BUG();
 		}
-		pgd = pgd_offset(mm, page);
-		pud = pud_offset(pgd, page);
-		pmd = pmd_offset(pud, page);
-		pte = pte_offset_kernel(pmd, page);
+		pgd = pgd_offset(mm, address);
+		pud = pud_offset(pgd, address);
+		pmd = pmd_offset(pud, address);
+		pte = pte_offset_kernel(pmd, address);
 	} while(!pte_present(*pte));
 	err = 0;
 	*pte = pte_mkyoung(*pte);
 	if(pte_write(*pte)) *pte = pte_mkdirty(*pte);
-	flush_tlb_page(vma, page);
- out:
+	flush_tlb_page(vma, address);
+out:
 	up_read(&mm->mmap_sem);
 	return(err);
 
@@ -144,19 +143,18 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void *sc)
 		panic("Kernel mode fault at addr 0x%lx, ip 0x%lx", 
 		      address, ip);
 
-	if(err == -EACCES){
+	if (err == -EACCES) {
 		si.si_signo = SIGBUS;
 		si.si_errno = 0;
 		si.si_code = BUS_ADRERR;
 		si.si_addr = (void *)address;
                 current->thread.arch.faultinfo = fi;
 		force_sig_info(SIGBUS, &si, current);
-	}
-	else if(err == -ENOMEM){
+	} else if (err == -ENOMEM) {
 		printk("VM: killing process %s\n", current->comm);
 		do_exit(SIGKILL);
-	}
-	else {
+	} else {
+		BUG_ON(err != -EFAULT);
 		si.si_signo = SIGSEGV;
 		si.si_addr = (void *) address;
                 current->thread.arch.faultinfo = fi;
@@ -200,30 +198,3 @@ void winch(int sig, union uml_pt_regs *regs)
 void trap_init(void)
 {
 }
-
-DEFINE_SPINLOCK(trap_lock);
-
-static int trap_index = 0;
-
-int next_trap_index(int limit)
-{
-	int ret;
-
-	spin_lock(&trap_lock);
-	ret = trap_index;
-	if(++trap_index == limit)
-		trap_index = 0;
-	spin_unlock(&trap_lock);
-	return(ret);
-}
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/kernel/trap_user.c b/arch/um/kernel/trap_user.c
index f825a6eda3f..e9ccd6b8d3c 100644
--- a/arch/um/kernel/trap_user.c
+++ b/arch/um/kernel/trap_user.c
@@ -40,35 +40,14 @@ void kill_child_dead(int pid)
 	} while(1);
 }
 
-/* Unlocked - don't care if this is a bit off */
-int nsegfaults = 0;
-
-struct {
-	unsigned long address;
-	int is_write;
-	int pid;
-	unsigned long sp;
-	int is_user;
-} segfault_record[1024];
-
 void segv_handler(int sig, union uml_pt_regs *regs)
 {
-	int index, max;
         struct faultinfo * fi = UPT_FAULTINFO(regs);
 
         if(UPT_IS_USER(regs) && !SEGV_IS_FIXABLE(fi)){
                 bad_segv(*fi, UPT_IP(regs));
 		return;
 	}
-	max = sizeof(segfault_record)/sizeof(segfault_record[0]);
-	index = next_trap_index(max);
-
-	nsegfaults++;
-        segfault_record[index].address = FAULT_ADDRESS(*fi);
-	segfault_record[index].pid = os_getpid();
-        segfault_record[index].is_write = FAULT_WRITE(*fi);
-	segfault_record[index].sp = UPT_SP(regs);
-	segfault_record[index].is_user = UPT_IS_USER(regs);
         segv(*fi, UPT_IP(regs), UPT_IS_USER(regs), regs);
 }
 
diff --git a/arch/um/kernel/tt/include/uaccess-tt.h b/arch/um/kernel/tt/include/uaccess-tt.h
index 3fbb5fe26f4..aa6db384af8 100644
--- a/arch/um/kernel/tt/include/uaccess-tt.h
+++ b/arch/um/kernel/tt/include/uaccess-tt.h
@@ -33,7 +33,7 @@ extern unsigned long uml_physmem;
          (((unsigned long) (addr) <= ((unsigned long) (addr) + (size))) && \
           (under_task_size(addr, size) || is_stack(addr, size))))
 
-static inline int verify_area_tt(int type, const void * addr,
+static inline int verify_area_tt(int type, const void __user * addr,
                                  unsigned long size)
 {
 	return(access_ok_tt(type, addr, size) ? 0 : -EFAULT);
@@ -50,12 +50,12 @@ extern int __do_clear_user(void *mem, size_t len, void **fault_addr,
 extern int __do_strnlen_user(const char *str, unsigned long n,
 			     void **fault_addr, void **fault_catcher);
 
-extern int copy_from_user_tt(void *to, const void *from, int n);
-extern int copy_to_user_tt(void *to, const void *from, int n);
-extern int strncpy_from_user_tt(char *dst, const char *src, int count);
-extern int __clear_user_tt(void *mem, int len);
-extern int clear_user_tt(void *mem, int len);
-extern int strnlen_user_tt(const void *str, int len);
+extern int copy_from_user_tt(void *to, const void __user *from, int n);
+extern int copy_to_user_tt(void __user *to, const void *from, int n);
+extern int strncpy_from_user_tt(char *dst, const char __user *src, int count);
+extern int __clear_user_tt(void __user *mem, int len);
+extern int clear_user_tt(void __user *mem, int len);
+extern int strnlen_user_tt(const void __user *str, int len);
 
 #endif
 
diff --git a/arch/um/kernel/tt/syscall_kern.c b/arch/um/kernel/tt/syscall_kern.c
index 2650a628719..3d29c90514c 100644
--- a/arch/um/kernel/tt/syscall_kern.c
+++ b/arch/um/kernel/tt/syscall_kern.c
@@ -12,36 +12,41 @@
 #include "asm/uaccess.h"
 #include "asm/stat.h"
 #include "sysdep/syscalls.h"
+#include "sysdep/sigcontext.h"
 #include "kern_util.h"
+#include "syscall.h"
 
-extern syscall_handler_t *sys_call_table[];
-
-long execute_syscall_tt(void *r)
+void syscall_handler_tt(int sig, struct pt_regs *regs)
 {
-	struct pt_regs *regs = r;
-	long res;
+	void *sc;
+	long result;
 	int syscall;
-
 #ifdef CONFIG_SYSCALL_DEBUG
+	int index;
+  	index = record_syscall_start(syscall);
+#endif
+	sc = UPT_SC(&regs->regs);
+	SC_START_SYSCALL(sc);
+
+	syscall_trace(&regs->regs, 0);
+
 	current->thread.nsyscalls++;
 	nsyscalls++;
-#endif
 	syscall = UPT_SYSCALL_NR(&regs->regs);
 
 	if((syscall >= NR_syscalls) || (syscall < 0))
-		res = -ENOSYS;
-	else res = EXECUTE_SYSCALL(syscall, regs);
+		result = -ENOSYS;
+	else result = EXECUTE_SYSCALL(syscall, regs);
 
-	return(res);
-}
+	/* regs->sc may have changed while the system call ran (there may
+	 * have been an interrupt or segfault), so it needs to be refreshed.
+	 */
+	UPT_SC(&regs->regs) = sc;
 
-/*
- * 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:
- */
+	SC_SET_SYSCALL_RETURN(sc, result);
+
+	syscall_trace(&regs->regs, 1);
+#ifdef CONFIG_SYSCALL_DEBUG
+  	record_syscall_end(index, result);
+#endif
+}
diff --git a/arch/um/kernel/tt/syscall_user.c b/arch/um/kernel/tt/syscall_user.c
index b218316cfdb..902987bf379 100644
--- a/arch/um/kernel/tt/syscall_user.c
+++ b/arch/um/kernel/tt/syscall_user.c
@@ -13,42 +13,9 @@
 #include "task.h"
 #include "user_util.h"
 #include "kern_util.h"
-#include "syscall_user.h"
+#include "syscall.h"
 #include "tt.h"
 
-
-void syscall_handler_tt(int sig, union uml_pt_regs *regs)
-{
-	void *sc;
-	long result;
-	int syscall;
-#ifdef UML_CONFIG_DEBUG_SYSCALL
-	int index;
-#endif
-
-	syscall = UPT_SYSCALL_NR(regs);
-	sc = UPT_SC(regs);
-	SC_START_SYSCALL(sc);
-
-#ifdef UML_CONFIG_DEBUG_SYSCALL
-  	index = record_syscall_start(syscall);
-#endif
-	syscall_trace(regs, 0);
-	result = execute_syscall_tt(regs);
-
-	/* regs->sc may have changed while the system call ran (there may
-	 * have been an interrupt or segfault), so it needs to be refreshed.
-	 */
-	UPT_SC(regs) = sc;
-
-	SC_SET_SYSCALL_RETURN(sc, result);
-
-	syscall_trace(regs, 1);
-#ifdef UML_CONFIG_DEBUG_SYSCALL
-  	record_syscall_end(index, result);
-#endif
-}
-
 void do_sigtrap(void *task)
 {
 	UPT_SYSCALL_NR(TASK_REGS(task)) = -1;
diff --git a/arch/um/kernel/tt/tlb.c b/arch/um/kernel/tt/tlb.c
index 2eefb43bc9c..f1d85dbb45b 100644
--- a/arch/um/kernel/tt/tlb.c
+++ b/arch/um/kernel/tt/tlb.c
@@ -17,25 +17,31 @@
 #include "os.h"
 #include "tlb.h"
 
-static void do_ops(union mm_context *mmu, struct host_vm_op *ops, int last)
+static int do_ops(union mm_context *mmu, struct host_vm_op *ops, int last,
+		    int finished, void **flush)
 {
 	struct host_vm_op *op;
-	int i;
+        int i, ret=0;
 
-	for(i = 0; i <= last; i++){
+        for(i = 0; i <= last && !ret; i++){
 		op = &ops[i];
 		switch(op->type){
 		case MMAP:
-                        os_map_memory((void *) op->u.mmap.addr, op->u.mmap.fd,
-				      op->u.mmap.offset, op->u.mmap.len,
-				      op->u.mmap.r, op->u.mmap.w,
-				      op->u.mmap.x);
+                        ret = os_map_memory((void *) op->u.mmap.addr,
+                                            op->u.mmap.fd, op->u.mmap.offset,
+                                            op->u.mmap.len, op->u.mmap.r,
+                                            op->u.mmap.w, op->u.mmap.x);
 			break;
 		case MUNMAP:
-			os_unmap_memory((void *) op->u.munmap.addr,
-					op->u.munmap.len);
+                        ret = os_unmap_memory((void *) op->u.munmap.addr,
+                                              op->u.munmap.len);
 			break;
 		case MPROTECT:
+                        ret = protect_memory(op->u.mprotect.addr,
+                                             op->u.munmap.len,
+                                             op->u.mprotect.r,
+                                             op->u.mprotect.w,
+                                             op->u.mprotect.x, 1);
 			protect_memory(op->u.mprotect.addr, op->u.munmap.len,
 				       op->u.mprotect.r, op->u.mprotect.w,
 				       op->u.mprotect.x, 1);
@@ -45,6 +51,8 @@ static void do_ops(union mm_context *mmu, struct host_vm_op *ops, int last)
 			break;
 		}
 	}
+
+	return ret;
 }
 
 static void fix_range(struct mm_struct *mm, unsigned long start_addr, 
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index ca2bb6f09a7..09f6f7ce469 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -126,7 +126,7 @@ unsigned long start_vm;
 unsigned long end_vm;
 int ncpus = 1;
 
-#ifdef CONFIG_MODE_TT
+#ifdef CONFIG_CMDLINE_ON_HOST
 /* Pointer set in linux_main, the array itself is private to each thread,
  * and changed at address space creation time so this poses no concurrency
  * problems.
@@ -141,7 +141,7 @@ long physmem_size = 32 * 1024 * 1024;
 
 void set_cmdline(char *cmd)
 {
-#ifdef CONFIG_MODE_TT
+#ifdef CONFIG_CMDLINE_ON_HOST
 	char *umid, *ptr;
 
 	if(CHOOSE_MODE(honeypot, 0)) return;
@@ -333,6 +333,7 @@ int linux_main(int argc, char **argv)
 	if(have_root == 0)
 		add_arg(DEFAULT_COMMAND_LINE);
 
+	os_early_checks();
 	mode_tt = force_tt ? 1 : !can_do_skas();
 #ifndef CONFIG_MODE_TT
 	if (mode_tt) {
@@ -385,7 +386,7 @@ int linux_main(int argc, char **argv)
 
 	setup_machinename(system_utsname.machine);
 
-#ifdef CONFIG_MODE_TT
+#ifdef CONFIG_CMDLINE_ON_HOST
 	argv1_begin = argv[1];
 	argv1_end = &argv[1][strlen(argv[1])];
 #endif
@@ -470,7 +471,6 @@ void __init setup_arch(char **cmdline_p)
 void __init check_bugs(void)
 {
 	arch_check_bugs();
-	check_ptrace();
 	check_sigio();
 	check_devanon();
 }
diff --git a/arch/um/os-Linux/Makefile b/arch/um/os-Linux/Makefile
index 4ddf540284c..7a1662419c0 100644
--- a/arch/um/os-Linux/Makefile
+++ b/arch/um/os-Linux/Makefile
@@ -3,11 +3,19 @@
 # Licensed under the GPL
 #
 
-obj-y = elf_aux.o file.o process.o signal.o time.o tty.o user_syms.o drivers/ \
-	sys-$(SUBARCH)/
+obj-y = aio.o elf_aux.o file.o process.o signal.o start_up.o time.o tt.o \
+	tty.o user_syms.o drivers/ sys-$(SUBARCH)/
 
-USER_OBJS := elf_aux.o file.o process.o signal.o time.o tty.o
+USER_OBJS := aio.o elf_aux.o file.o process.o signal.o start_up.o time.o tt.o \
+	tty.o
+
+elf_aux.o: $(ARCH_DIR)/kernel-offsets.h
+CFLAGS_elf_aux.o += -I$(objtree)/arch/um
 
 CFLAGS_user_syms.o += -DSUBARCH_$(SUBARCH)
 
+HAVE_AIO_ABI := $(shell [ -r /usr/include/linux/aio_abi.h ] && \
+	echo -DHAVE_AIO_ABI )
+CFLAGS_aio.o += $(HAVE_AIO_ABI)
+
 include arch/um/scripts/Makefile.rules
diff --git a/arch/um/os-Linux/aio.c b/arch/um/os-Linux/aio.c
new file mode 100644
index 00000000000..b04897cd995
--- /dev/null
+++ b/arch/um/os-Linux/aio.c
@@ -0,0 +1,414 @@
+/*
+ * Copyright (C) 2004 Jeff Dike (jdike@addtoit.com)
+ * Licensed under the GPL
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <signal.h>
+#include <string.h>
+#include <errno.h>
+#include <sched.h>
+#include <sys/syscall.h>
+#include "os.h"
+#include "helper.h"
+#include "aio.h"
+#include "init.h"
+#include "user.h"
+#include "mode.h"
+
+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>
+
+/* If we have the headers, we are going to build with AIO enabled.
+ * If we don't have aio in libc, we define the necessary stubs here.
+ */
+
+#if !defined(HAVE_AIO_LIBC)
+
+static long io_setup(int n, aio_context_t *ctxp)
+{
+        return syscall(__NR_io_setup, n, ctxp);
+}
+
+static long io_submit(aio_context_t ctx, long nr, struct iocb **iocbpp)
+{
+        return syscall(__NR_io_submit, ctx, nr, iocbpp);
+}
+
+static long io_getevents(aio_context_t ctx_id, long min_nr, long nr,
+                         struct io_event *events, struct timespec *timeout)
+{
+        return syscall(__NR_io_getevents, ctx_id, min_nr, nr, events, timeout);
+}
+
+#endif
+
+/* The AIO_MMAP cases force the mmapped page into memory here
+ * rather than in whatever place first touches the data.  I used
+ * to do this by touching the page, but that's delicate because
+ * gcc is prone to optimizing that away.  So, what's done here
+ * is we read from the descriptor from which the page was
+ * mapped.  The caller is required to pass an offset which is
+ * inside the page that was mapped.  Thus, when the read
+ * returns, we know that the page is in the page cache, and
+ * that it now backs the mmapped area.
+ */
+
+static int do_aio(aio_context_t ctx, struct aio_context *aio)
+{
+        struct iocb iocb, *iocbp = &iocb;
+        char c;
+        int err;
+
+        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_reserved1	= 0,
+                                .aio_reserved2	= 0,
+                                .aio_reserved3	= 0 });
+
+        switch(aio->type){
+        case AIO_READ:
+                iocb.aio_lio_opcode = IOCB_CMD_PREAD;
+                break;
+        case AIO_WRITE:
+                iocb.aio_lio_opcode = IOCB_CMD_PWRITE;
+                break;
+        case AIO_MMAP:
+                iocb.aio_lio_opcode = IOCB_CMD_PREAD;
+                iocb.aio_buf = (unsigned long) &c;
+                iocb.aio_nbytes = sizeof(c);
+                break;
+        default:
+                printk("Bogus op in do_aio - %d\n", aio->type);
+                err = -EINVAL;
+                goto out;
+        }
+
+        err = io_submit(ctx, 1, &iocbp);
+        if(err > 0)
+                err = 0;
+
+ out:
+        return err;
+}
+
+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;
+
+        signal(SIGWINCH, SIG_IGN);
+
+        while(1){
+                n = io_getevents(ctx, 1, 1, &event, NULL);
+                if(n < 0){
+                        if(errno == EINTR)
+                                continue;
+                        printk("aio_thread - io_getevents failed, "
+                               "errno = %d\n", errno);
+                }
+                else {
+			aio = (struct aio_context *) 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));
+                        if(err != sizeof(reply))
+				printk("aio_thread - write failed, "
+				       "fd = %d, err = %d\n", aio->reply_fd,
+				       -err);
+                }
+        }
+        return 0;
+}
+
+#endif
+
+static int do_not_aio(struct aio_context *aio)
+{
+        char c;
+        int err;
+
+        switch(aio->type){
+        case AIO_READ:
+                err = os_seek_file(aio->fd, aio->offset);
+                if(err)
+                        goto out;
+
+                err = os_read_file(aio->fd, aio->data, aio->len);
+                break;
+        case AIO_WRITE:
+                err = os_seek_file(aio->fd, aio->offset);
+                if(err)
+                        goto out;
+
+                err = os_write_file(aio->fd, aio->data, aio->len);
+                break;
+        case AIO_MMAP:
+                err = os_seek_file(aio->fd, aio->offset);
+                if(err)
+                        goto out;
+
+                err = os_read_file(aio->fd, &c, sizeof(c));
+                break;
+        default:
+                printk("do_not_aio - bad request type : %d\n", aio->type);
+                err = -EINVAL;
+                break;
+        }
+
+ out:
+        return err;
+}
+
+static int not_aio_thread(void *arg)
+{
+        struct aio_context *aio;
+        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)){
+                        if(err < 0)
+                                printk("not_aio_thread - read failed, "
+                                       "fd = %d, err = %d\n", aio_req_fd_r,
+                                       -err);
+                        else {
+                                printk("not_aio_thread - short read, fd = %d, "
+                                       "length = %d\n", aio_req_fd_r, err);
+                        }
+                        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));
+                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)
+{
+        unsigned long stack;
+        int fds[2], err;
+
+        err = os_pipe(fds, 1, 1);
+        if(err)
+                goto out;
+
+        aio_req_fd_w = fds[0];
+        aio_req_fd_r = fds[1];
+        err = run_helper_thread(not_aio_thread, NULL,
+                                CLONE_FILES | CLONE_VM | SIGCHLD, &stack, 0);
+        if(err < 0)
+                goto out_close_pipe;
+
+        aio_pid = err;
+        goto out;
+
+ out_close_pipe:
+        os_close_file(fds[0]);
+        os_close_file(fds[1]);
+        aio_req_fd_w = -1;
+        aio_req_fd_r = -1;
+ out:
+#ifndef HAVE_AIO_ABI
+	printk("/usr/include/linux/aio_abi.h not present during build\n");
+#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;
+        int err;
+
+        if(io_setup(256, &ctx)){
+                printk("aio_thread failed to initialize context, err = %d\n",
+                       errno);
+                return -errno;
+        }
+
+        err = run_helper_thread(aio_thread, NULL,
+                                CLONE_FILES | CLONE_VM | SIGCHLD, &stack, 0);
+        if(err < 0)
+                return -errno;
+
+        aio_pid = err;
+
+	printk("Using 2.6 host AIO\n");
+
+	submit_proc = submit_aio_26;
+
+        return 0;
+}
+
+#else
+#define DEFAULT_24_AIO 1
+static int submit_aio_26(struct aio_context *aio)
+{
+        return -ENOSYS;
+}
+
+static int init_aio_26(void)
+{
+	submit_proc = submit_aio_26;
+        return -ENOSYS;
+}
+#endif
+
+static int aio_24 = DEFAULT_24_AIO;
+
+static int __init set_aio_24(char *name, int *add)
+{
+        aio_24 = 1;
+        return 0;
+}
+
+__uml_setup("aio=2.4", set_aio_24,
+"aio=2.4\n"
+"    This is used to force UML to use 2.4-style AIO even when 2.6 AIO is\n"
+"    available.  2.4 AIO is a single thread that handles one request at a\n"
+"    time, synchronously.  2.6 AIO is a thread which uses the 2.6 AIO \n"
+"    interface to handle an arbitrary number of pending requests.  2.6 AIO \n"
+"    is not available in tt mode, on 2.4 hosts, or when UML is built with\n"
+"    /usr/include/linux/aio_abi.h not available.  Many distributions don't\n"
+"    include aio_abi.h, so you will need to copy it from a kernel tree to\n"
+"    your /usr/include/linux in order to build an AIO-capable UML\n\n"
+);
+
+static int init_aio(void)
+{
+        int err;
+
+        CHOOSE_MODE(({
+                if(!aio_24){
+                        printk("Disabling 2.6 AIO in tt mode\n");
+                        aio_24 = 1;
+                } }), (void) 0);
+
+        if(!aio_24){
+                err = init_aio_26();
+                if(err && (errno == ENOSYS)){
+                        printk("2.6 AIO not supported on the host - "
+                               "reverting to 2.4 AIO\n");
+                        aio_24 = 1;
+                }
+                else return err;
+        }
+
+        if(aio_24)
+                return init_aio_24();
+
+        return 0;
+}
+
+/* The reason for the __initcall/__uml_exitcall asymmetry is that init_aio
+ * needs to be called when the kernel is running because it calls run_helper,
+ * which needs get_free_page.  exit_aio is a __uml_exitcall because the generic
+ * kernel does not run __exitcalls on shutdown, and can't because many of them
+ * break when called outside of module unloading.
+ */
+__initcall(init_aio);
+
+static void exit_aio(void)
+{
+        if(aio_pid != -1)
+                os_kill_process(aio_pid, 1);
+}
+
+__uml_exitcall(exit_aio);
+
+int submit_aio(struct aio_context *aio)
+{
+	return (*submit_proc)(aio);
+}
diff --git a/arch/um/os-Linux/elf_aux.c b/arch/um/os-Linux/elf_aux.c
index 4cca3e9c23f..1399520a858 100644
--- a/arch/um/os-Linux/elf_aux.c
+++ b/arch/um/os-Linux/elf_aux.c
@@ -12,8 +12,9 @@
 #include "init.h"
 #include "elf_user.h"
 #include "mem_user.h"
+#include <kernel-offsets.h>
 
-#if ELF_CLASS == ELFCLASS32
+#if HOST_ELF_CLASS == ELFCLASS32
 typedef Elf32_auxv_t elf_auxv_t;
 #else
 typedef Elf64_auxv_t elf_auxv_t;
diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c
index 1e126bfd31a..d32413e4b4c 100644
--- a/arch/um/os-Linux/process.c
+++ b/arch/um/os-Linux/process.c
@@ -3,10 +3,10 @@
  * Licensed under the GPL
  */
 
-#include <unistd.h>
 #include <stdio.h>
 #include <errno.h>
 #include <signal.h>
+#include <setjmp.h>
 #include <linux/unistd.h>
 #include <sys/mman.h>
 #include <sys/wait.h>
@@ -14,6 +14,10 @@
 #include "os.h"
 #include "user.h"
 #include "user_util.h"
+#include "signal_user.h"
+#include "process.h"
+#include "irq_user.h"
+#include "kern_util.h"
 
 #define ARBITRARY_ADDR -1
 #define FAILURE_PID    -1
@@ -114,8 +118,10 @@ void os_usr1_process(int pid)
 	kill(pid, SIGUSR1);
 }
 
-/*Don't use the glibc version, which caches the result in TLS. It misses some
- * syscalls, and also breaks with clone(), which does not unshare the TLS.*/
+/* Don't use the glibc version, which caches the result in TLS. It misses some
+ * syscalls, and also breaks with clone(), which does not unshare the TLS.
+ */
+
 inline _syscall0(pid_t, getpid)
 
 int os_getpid(void)
@@ -164,6 +170,52 @@ int os_unmap_memory(void *addr, int len)
         return(0);
 }
 
+void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int))
+{
+	int flags = 0, pages;
+
+	if(sig_stack != NULL){
+		pages = (1 << UML_CONFIG_KERNEL_STACK_ORDER);
+		set_sigstack(sig_stack, pages * page_size());
+		flags = SA_ONSTACK;
+	}
+	if(usr1_handler) set_handler(SIGUSR1, usr1_handler, flags, -1);
+}
+
+void init_new_thread_signals(int altstack)
+{
+	int flags = altstack ? SA_ONSTACK : 0;
+
+	set_handler(SIGSEGV, (__sighandler_t) sig_handler, flags,
+		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
+	set_handler(SIGTRAP, (__sighandler_t) sig_handler, flags,
+		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
+	set_handler(SIGFPE, (__sighandler_t) sig_handler, flags,
+		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
+	set_handler(SIGILL, (__sighandler_t) sig_handler, flags,
+		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
+	set_handler(SIGBUS, (__sighandler_t) sig_handler, flags,
+		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
+	set_handler(SIGUSR2, (__sighandler_t) sig_handler,
+		    flags, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
+	signal(SIGHUP, SIG_IGN);
+
+	init_irq_signals(altstack);
+}
+
+int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr)
+{
+       sigjmp_buf buf;
+       int n;
+
+       *jmp_ptr = &buf;
+       n = sigsetjmp(buf, 1);
+       if(n != 0)
+               return(n);
+       (*fn)(arg);
+       return(0);
+}
+
 /*
  * Overrides for Emacs so that we follow Linus's tabbing style.
  * Emacs will notice this stuff at the end of the file and automatically
diff --git a/arch/um/kernel/process.c b/arch/um/os-Linux/start_up.c
index 67acd92c532..040cc1472bc 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/os-Linux/start_up.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
@@ -19,7 +19,6 @@
 #include "user_util.h"
 #include "kern_util.h"
 #include "user.h"
-#include "process.h"
 #include "signal_kern.h"
 #include "signal_user.h"
 #include "sysdep/ptrace.h"
@@ -39,98 +38,6 @@
 #include "registers.h"
 #endif
 
-void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int))
-{
-	int flags = 0, pages;
-
-	if(sig_stack != NULL){
-		pages = (1 << UML_CONFIG_KERNEL_STACK_ORDER);
-		set_sigstack(sig_stack, pages * page_size());
-		flags = SA_ONSTACK;
-	}
-	if(usr1_handler) set_handler(SIGUSR1, usr1_handler, flags, -1);
-}
-
-void init_new_thread_signals(int altstack)
-{
-	int flags = altstack ? SA_ONSTACK : 0;
-
-	set_handler(SIGSEGV, (__sighandler_t) sig_handler, flags,
-		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
-	set_handler(SIGTRAP, (__sighandler_t) sig_handler, flags, 
-		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
-	set_handler(SIGFPE, (__sighandler_t) sig_handler, flags, 
-		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
-	set_handler(SIGILL, (__sighandler_t) sig_handler, flags, 
-		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
-	set_handler(SIGBUS, (__sighandler_t) sig_handler, flags, 
-		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
-	set_handler(SIGUSR2, (__sighandler_t) sig_handler, 
-		    flags, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
-	signal(SIGHUP, SIG_IGN);
-
-	init_irq_signals(altstack);
-}
-
-struct tramp {
-	int (*tramp)(void *);
-	void *tramp_data;
-	unsigned long temp_stack;
-	int flags;
-	int pid;
-};
-
-/* See above for why sigkill is here */
-
-int sigkill = SIGKILL;
-
-int outer_tramp(void *arg)
-{
-	struct tramp *t;
-	int sig = sigkill;
-
-	t = arg;
-	t->pid = clone(t->tramp, (void *) t->temp_stack + page_size()/2,
-		       t->flags, t->tramp_data);
-	if(t->pid > 0) wait_for_stop(t->pid, SIGSTOP, PTRACE_CONT, NULL);
-	kill(os_getpid(), sig);
-	_exit(0);
-}
-
-int start_fork_tramp(void *thread_arg, unsigned long temp_stack, 
-		     int clone_flags, int (*tramp)(void *))
-{
-	struct tramp arg;
-	unsigned long sp;
-	int new_pid, status, err;
-
-	/* The trampoline will run on the temporary stack */
-	sp = stack_sp(temp_stack);
-
-	clone_flags |= CLONE_FILES | SIGCHLD;
-
-	arg.tramp = tramp;
-	arg.tramp_data = thread_arg;
-	arg.temp_stack = temp_stack;
-	arg.flags = clone_flags;
-
-	/* Start the process and wait for it to kill itself */
-	new_pid = clone(outer_tramp, (void *) sp, clone_flags, &arg);
-	if(new_pid < 0)
-		return(new_pid);
-
-	CATCH_EINTR(err = waitpid(new_pid, &status, 0));
-	if(err < 0)
-		panic("Waiting for outer trampoline failed - errno = %d",
-		      errno);
-
-	if(!WIFSIGNALED(status) || (WTERMSIG(status) != SIGKILL))
-		panic("outer trampoline didn't exit with SIGKILL, "
-		      "status = %d", status);
-
-	return(arg.pid);
-}
-
 static int ptrace_child(void *arg)
 {
 	int ret;
@@ -165,7 +72,7 @@ static int start_ptraced_child(void **stack_out)
 	void *stack;
 	unsigned long sp;
 	int pid, n, status;
-	
+
 	stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
 		     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 	if(stack == MAP_FAILED)
@@ -173,10 +80,10 @@ static int start_ptraced_child(void **stack_out)
 	sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
 	pid = clone(ptrace_child, (void *) sp, SIGCHLD, NULL);
 	if(pid < 0)
-		panic("check_ptrace : clone failed, errno = %d", errno);
+		panic("start_ptraced_child : clone failed, errno = %d", errno);
 	CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 	if(n < 0)
-		panic("check_ptrace : wait failed, errno = %d", errno);
+		panic("check_ptrace : clone failed, errno = %d", errno);
 	if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
 		panic("check_ptrace : expected SIGSTOP, got status = %d",
 		      status);
@@ -185,11 +92,14 @@ static int start_ptraced_child(void **stack_out)
 	return(pid);
 }
 
-/* When testing for SYSEMU support, if it is one of the broken versions, we must
- * just avoid using sysemu, not panic, but only if SYSEMU features are broken.
+/* When testing for SYSEMU support, if it is one of the broken versions, we
+ * must just avoid using sysemu, not panic, but only if SYSEMU features are
+ * broken.
  * So only for SYSEMU features we test mustpanic, while normal host features
- * must work anyway!*/
-static int stop_ptraced_child(int pid, void *stack, int exitcode, int mustpanic)
+ * must work anyway!
+ */
+static int stop_ptraced_child(int pid, void *stack, int exitcode,
+			      int mustpanic)
 {
 	int status, n, ret = 0;
 
@@ -217,8 +127,6 @@ static int stop_ptraced_child(int pid, void *stack, int exitcode, int mustpanic)
 	return ret;
 }
 
-static int force_sysemu_disabled = 0;
-
 int ptrace_faultinfo = 1;
 int proc_mm = 1;
 
@@ -228,29 +136,32 @@ static int __init skas0_cmd_param(char *str, int* add)
 	return 0;
 }
 
+__uml_setup("skas0", skas0_cmd_param,
+		"skas0\n"
+		"    Disables SKAS3 usage, so that SKAS0 is used, unless \n"
+	        "    you specify mode=tt.\n\n");
+
+static int force_sysemu_disabled = 0;
+
 static int __init nosysemu_cmd_param(char *str, int* add)
 {
 	force_sysemu_disabled = 1;
 	return 0;
 }
 
-__uml_setup("skas0", skas0_cmd_param,
-		"skas0\n"
-		"    Disables SKAS3 usage, so that SKAS0 is used, unless you \n"
-		"    specify mode=tt.\n\n");
-
 __uml_setup("nosysemu", nosysemu_cmd_param,
-		"nosysemu\n"
-		"    Turns off syscall emulation patch for ptrace (SYSEMU) on.\n"
-		"    SYSEMU is a performance-patch introduced by Laurent Vivier. It changes\n"
-		"    behaviour of ptrace() and helps reducing host context switch rate.\n"
-		"    To make it working, you need a kernel patch for your host, too.\n"
-		"    See http://perso.wanadoo.fr/laurent.vivier/UML/ for further information.\n\n");
+"nosysemu\n"
+"    Turns off syscall emulation patch for ptrace (SYSEMU) on.\n"
+"    SYSEMU is a performance-patch introduced by Laurent Vivier. It changes\n"
+"    behaviour of ptrace() and helps reducing host context switch rate.\n"
+"    To make it working, you need a kernel patch for your host, too.\n"
+"    See http://perso.wanadoo.fr/laurent.vivier/UML/ for further \n"
+"    information.\n\n");
 
 static void __init check_sysemu(void)
 {
 	void *stack;
-	int pid, syscall, n, status, count=0;
+ 	int pid, n, status, count=0;
 
 	printk("Checking syscall emulation patch for ptrace...");
 	sysemu_supported = 0;
@@ -281,6 +192,12 @@ static void __init check_sysemu(void)
 
 	printk("Checking advanced syscall emulation patch for ptrace...");
 	pid = start_ptraced_child(&stack);
+
+	if(ptrace(PTRACE_OLDSETOPTIONS, pid, 0,
+		  (void *) PTRACE_O_TRACESYSGOOD) < 0)
+		panic("check_ptrace: PTRACE_OLDSETOPTIONS failed, errno = %d",
+		      errno);
+
 	while(1){
 		count++;
 		if(ptrace(PTRACE_SYSEMU_SINGLESTEP, pid, 0, 0) < 0)
@@ -288,15 +205,10 @@ static void __init check_sysemu(void)
 		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 		if(n < 0)
 			panic("check_ptrace : wait failed, errno = %d", errno);
-		if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
-			panic("check_ptrace : expected (SIGTRAP|SYSCALL_TRAP), "
-			      "got status = %d", status);
-
-		syscall = ptrace(PTRACE_PEEKUSR, pid, PT_SYSCALL_NR_OFFSET,
-				 0);
-		if(syscall == __NR_getpid){
+		if(WIFSTOPPED(status) && (WSTOPSIG(status) == (SIGTRAP|0x80))){
 			if (!count)
-				panic("check_ptrace : SYSEMU_SINGLESTEP doesn't singlestep");
+				panic("check_ptrace : SYSEMU_SINGLESTEP "
+				      "doesn't singlestep");
 			n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET,
 				   os_getpid());
 			if(n < 0)
@@ -304,6 +216,11 @@ static void __init check_sysemu(void)
 				      "call return, errno = %d", errno);
 			break;
 		}
+		else if(WIFSTOPPED(status) && (WSTOPSIG(status) == SIGTRAP))
+			count++;
+		else
+			panic("check_ptrace : expected SIGTRAP or "
+			      "(SIGTRAP|0x80), got status = %d", status);
 	}
 	if (stop_ptraced_child(pid, stack, 0, 0) < 0)
 		goto fail_stopped;
@@ -321,7 +238,7 @@ fail_stopped:
 	printk("missing\n");
 }
 
-void __init check_ptrace(void)
+static void __init check_ptrace(void)
 {
 	void *stack;
 	int pid, syscall, n, status;
@@ -329,20 +246,20 @@ void __init check_ptrace(void)
 	printk("Checking that ptrace can change system call numbers...");
 	pid = start_ptraced_child(&stack);
 
-	if (ptrace(PTRACE_OLDSETOPTIONS, pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0)
-		panic("check_ptrace: PTRACE_SETOPTIONS failed, errno = %d", errno);
+	if(ptrace(PTRACE_OLDSETOPTIONS, pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0)
+		panic("check_ptrace: PTRACE_OLDSETOPTIONS failed, errno = %d", errno);
 
 	while(1){
 		if(ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0)
-			panic("check_ptrace : ptrace failed, errno = %d", 
+			panic("check_ptrace : ptrace failed, errno = %d",
 			      errno);
 		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 		if(n < 0)
 			panic("check_ptrace : wait failed, errno = %d", errno);
-		if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP + 0x80))
-			panic("check_ptrace : expected SIGTRAP + 0x80, "
+		if(!WIFSTOPPED(status) || (WSTOPSIG(status) != (SIGTRAP|0x80)))
+			panic("check_ptrace : expected (SIGTRAP|0x80), "
 			      "got status = %d", status);
-		
+
 		syscall = ptrace(PTRACE_PEEKUSR, pid, PT_SYSCALL_NR_OFFSET,
 				 0);
 		if(syscall == __NR_getpid){
@@ -359,33 +276,36 @@ void __init check_ptrace(void)
 	check_sysemu();
 }
 
-int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr)
+void os_early_checks(void)
 {
-	sigjmp_buf buf;
-	int n;
-
-	*jmp_ptr = &buf;
-	n = sigsetjmp(buf, 1);
-	if(n != 0)
-		return(n);
-	(*fn)(arg);
-	return(0);
+	check_ptrace();
 }
 
-void forward_pending_sigio(int target)
+static int __init noprocmm_cmd_param(char *str, int* add)
 {
-	sigset_t sigs;
+	proc_mm = 0;
+	return 0;
+}
+
+__uml_setup("noprocmm", noprocmm_cmd_param,
+"noprocmm\n"
+"    Turns off usage of /proc/mm, even if host supports it.\n"
+"    To support /proc/mm, the host needs to be patched using\n"
+"    the current skas3 patch.\n\n");
 
-	if(sigpending(&sigs)) 
-		panic("forward_pending_sigio : sigpending failed");
-	if(sigismember(&sigs, SIGIO))
-		kill(target, SIGIO);
+static int __init noptracefaultinfo_cmd_param(char *str, int* add)
+{
+	ptrace_faultinfo = 0;
+	return 0;
 }
 
-extern void *__syscall_stub_start, __syscall_stub_end;
+__uml_setup("noptracefaultinfo", noptracefaultinfo_cmd_param,
+"noptracefaultinfo\n"
+"    Turns off usage of PTRACE_FAULTINFO, even if host supports\n"
+"    it. To support PTRACE_FAULTINFO, the host needs to be patched\n"
+"    using the current skas3 patch.\n\n");
 
 #ifdef UML_CONFIG_MODE_SKAS
-
 static inline void check_skas3_ptrace_support(void)
 {
 	struct ptrace_faultinfo fi;
@@ -400,9 +320,8 @@ static inline void check_skas3_ptrace_support(void)
 		ptrace_faultinfo = 0;
 		if(errno == EIO)
 			printf("not found\n");
-		else {
+		else
 			perror("not found");
-		}
 	}
 	else {
 		if (!ptrace_faultinfo)
@@ -419,9 +338,10 @@ int can_do_skas(void)
 {
 	printf("Checking for /proc/mm...");
 	if (os_access("/proc/mm", OS_ACC_W_OK) < 0) {
-		proc_mm = 0;
+ 		proc_mm = 0;
 		printf("not found\n");
-	} else {
+	}
+	else {
 		if (!proc_mm)
 			printf("found but disabled on command line\n");
 		else
diff --git a/arch/um/os-Linux/tt.c b/arch/um/os-Linux/tt.c
new file mode 100644
index 00000000000..5b047ab8416
--- /dev/null
+++ b/arch/um/os-Linux/tt.c
@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <signal.h>
+#include <sched.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <setjmp.h>
+#include <sys/time.h>
+#include <sys/ptrace.h>
+#include <linux/ptrace.h>
+#include <sys/wait.h>
+#include <sys/mman.h>
+#include <asm/ptrace.h>
+#include <asm/unistd.h>
+#include <asm/page.h>
+#include "user_util.h"
+#include "kern_util.h"
+#include "user.h"
+#include "signal_kern.h"
+#include "signal_user.h"
+#include "sysdep/ptrace.h"
+#include "sysdep/sigcontext.h"
+#include "irq_user.h"
+#include "ptrace_user.h"
+#include "time_user.h"
+#include "init.h"
+#include "os.h"
+#include "uml-config.h"
+#include "choose-mode.h"
+#include "mode.h"
+#include "tempfile.h"
+
+/*
+ *-------------------------
+ * only for tt mode (will be deleted in future...)
+ *-------------------------
+ */
+
+struct tramp {
+	int (*tramp)(void *);
+	void *tramp_data;
+	unsigned long temp_stack;
+	int flags;
+	int pid;
+};
+
+/* See above for why sigkill is here */
+
+int sigkill = SIGKILL;
+
+int outer_tramp(void *arg)
+{
+	struct tramp *t;
+	int sig = sigkill;
+
+	t = arg;
+	t->pid = clone(t->tramp, (void *) t->temp_stack + page_size()/2,
+		       t->flags, t->tramp_data);
+	if(t->pid > 0) wait_for_stop(t->pid, SIGSTOP, PTRACE_CONT, NULL);
+	kill(os_getpid(), sig);
+	_exit(0);
+}
+
+int start_fork_tramp(void *thread_arg, unsigned long temp_stack,
+		     int clone_flags, int (*tramp)(void *))
+{
+	struct tramp arg;
+	unsigned long sp;
+	int new_pid, status, err;
+
+	/* The trampoline will run on the temporary stack */
+	sp = stack_sp(temp_stack);
+
+	clone_flags |= CLONE_FILES | SIGCHLD;
+
+	arg.tramp = tramp;
+	arg.tramp_data = thread_arg;
+	arg.temp_stack = temp_stack;
+	arg.flags = clone_flags;
+
+	/* Start the process and wait for it to kill itself */
+	new_pid = clone(outer_tramp, (void *) sp, clone_flags, &arg);
+	if(new_pid < 0)
+		return(new_pid);
+
+	CATCH_EINTR(err = waitpid(new_pid, &status, 0));
+	if(err < 0)
+		panic("Waiting for outer trampoline failed - errno = %d",
+		      errno);
+
+	if(!WIFSIGNALED(status) || (WTERMSIG(status) != SIGKILL))
+		panic("outer trampoline didn't exit with SIGKILL, "
+		      "status = %d", status);
+
+	return(arg.pid);
+}
+
+void forward_pending_sigio(int target)
+{
+	sigset_t sigs;
+
+	if(sigpending(&sigs))
+		panic("forward_pending_sigio : sigpending failed");
+	if(sigismember(&sigs, SIGIO))
+		kill(target, SIGIO);
+}
+
diff --git a/arch/um/scripts/Makefile.rules b/arch/um/scripts/Makefile.rules
index 17f305b6bad..59a1291f477 100644
--- a/arch/um/scripts/Makefile.rules
+++ b/arch/um/scripts/Makefile.rules
@@ -9,6 +9,11 @@ USER_OBJS := $(foreach file,$(USER_OBJS),$(obj)/$(file))
 
 $(USER_OBJS) : c_flags = -Wp,-MD,$(depfile) $(USER_CFLAGS) \
 	$(CFLAGS_$(notdir $@))
+$(USER_OBJS): cmd_checksrc =
+$(USER_OBJS): quiet_cmd_checksrc =
+$(USER_OBJS): cmd_force_checksrc =
+$(USER_OBJS): quiet_cmd_force_checksrc =
+
 
 # The stubs and unmap.o can't try to call mcount or update basic block data
 define unprofile
diff --git a/arch/um/scripts/Makefile.unmap b/arch/um/scripts/Makefile.unmap
index 802d027a1e1..b2165188d94 100644
--- a/arch/um/scripts/Makefile.unmap
+++ b/arch/um/scripts/Makefile.unmap
@@ -12,7 +12,7 @@ $(obj)/unmap.o: _c_flags = $(call unprofile,$(CFLAGS))
 
 quiet_cmd_wrapld = LD      $@
 define cmd_wrapld
-	$(LD) $(LDFLAGS) -r -o $(obj)/unmap_tmp.o $< $(shell $(CC) $(CFLAGS) -print-file-name=libc.a); \
+	$(LD) $(LDFLAGS) -r -o $(obj)/unmap_tmp.o $< ; \
 	$(OBJCOPY) $(UML_OBJCOPYFLAGS) $(obj)/unmap_tmp.o $@ -G switcheroo
 endef
 
diff --git a/arch/um/sys-i386/Makefile b/arch/um/sys-i386/Makefile
index 77c3c4d29f5..4ca2a229da4 100644
--- a/arch/um/sys-i386/Makefile
+++ b/arch/um/sys-i386/Makefile
@@ -16,13 +16,7 @@ semaphore.c-dir = kernel
 highmem.c-dir = mm
 module.c-dir = kernel
 
-STUB_CFLAGS = -Wp,-MD,$(depfile) $(call unprofile,$(USER_CFLAGS))
-
-# _cflags works with kernel files, not with userspace ones, but c_flags does,
-# why ask why?
-$(obj)/stub_segv.o : c_flags = $(STUB_CFLAGS)
-
-$(obj)/stub.o : a_flags = $(STUB_CFLAGS)
+$(obj)/stub_segv.o : _c_flags = $(call unprofile,$(CFLAGS))
 
 subdir- := util
 
diff --git a/arch/um/sys-i386/kernel-offsets.c b/arch/um/sys-i386/kernel-offsets.c
index 9f8ecd1fdd9..a1070af2bcd 100644
--- a/arch/um/sys-i386/kernel-offsets.c
+++ b/arch/um/sys-i386/kernel-offsets.c
@@ -2,6 +2,7 @@
 #include <linux/stddef.h>
 #include <linux/sched.h>
 #include <linux/time.h>
+#include <linux/elf.h>
 #include <asm/page.h>
 
 #define DEFINE(sym, val) \
diff --git a/arch/um/sys-i386/signal.c b/arch/um/sys-i386/signal.c
index 4efc69a039d..16bc19928b3 100644
--- a/arch/um/sys-i386/signal.c
+++ b/arch/um/sys-i386/signal.c
@@ -122,9 +122,9 @@ int copy_sc_from_user_tt(struct sigcontext *to, struct sigcontext *from,
 	int err;
 
 	to_fp = to->fpstate;
-	from_fp = from->fpstate;
 	sigs = to->oldmask;
 	err = copy_from_user(to, from, sizeof(*to));
+	from_fp = to->fpstate;
 	to->oldmask = sigs;
 	to->fpstate = to_fp;
 	if(to_fp != NULL)
diff --git a/arch/um/sys-i386/stub.S b/arch/um/sys-i386/stub.S
index 2f2c70a8f04..6a70d9ab5c2 100644
--- a/arch/um/sys-i386/stub.S
+++ b/arch/um/sys-i386/stub.S
@@ -2,7 +2,50 @@
 
 	.globl syscall_stub
 .section .__syscall_stub, "x"
-syscall_stub:
-	int 	$0x80
+
+	.globl batch_syscall_stub
+batch_syscall_stub:
+	/* load pointer to first operation */
+	mov	$(UML_CONFIG_STUB_DATA+8), %esp
+
+again:
+	/* load length of additional data */
+	mov	0x0(%esp), %eax
+
+	/* if(length == 0) : end of list */
+	/* write possible 0 to header */
+	mov	%eax, UML_CONFIG_STUB_DATA+4
+	cmpl	$0, %eax
+	jz	done
+
+	/* save current pointer */
+	mov	%esp, UML_CONFIG_STUB_DATA+4
+
+	/* skip additional data */
+	add	%eax, %esp
+
+	/* load syscall-# */
+	pop	%eax
+
+	/* load syscall params */
+	pop	%ebx
+	pop	%ecx
+	pop	%edx
+	pop	%esi
+ 	pop	%edi
+	pop	%ebp
+
+	/* execute syscall */
+	int	$0x80
+
+	/* check return value */
+	pop	%ebx
+	cmp	%ebx, %eax
+	je	again
+
+done:
+	/* save return value */
 	mov	%eax, UML_CONFIG_STUB_DATA
+
+	/* stop */
 	int3
diff --git a/arch/um/sys-i386/stub_segv.c b/arch/um/sys-i386/stub_segv.c
index 68aeabe3a65..1e88b275eda 100644
--- a/arch/um/sys-i386/stub_segv.c
+++ b/arch/um/sys-i386/stub_segv.c
@@ -3,8 +3,7 @@
  * Licensed under the GPL
  */
 
-#include <signal.h>
-#include <asm/sigcontext.h>
+#include <asm/signal.h>
 #include <asm/unistd.h>
 #include "uml-config.h"
 #include "sysdep/sigcontext.h"
diff --git a/arch/um/sys-x86_64/Makefile b/arch/um/sys-x86_64/Makefile
index 7488206ce6f..f0ab574d1e9 100644
--- a/arch/um/sys-x86_64/Makefile
+++ b/arch/um/sys-x86_64/Makefile
@@ -6,7 +6,7 @@
 
 #XXX: why into lib-y?
 lib-y = bitops.o bugs.o csum-partial.o delay.o fault.o mem.o memcpy.o \
-	ptrace.o ptrace_user.o semaphore.o sigcontext.o signal.o stub.o \
+	ptrace.o ptrace_user.o sigcontext.o signal.o stub.o \
 	stub_segv.o syscalls.o syscall_table.o sysrq.o thunk.o
 
 obj-y := ksyms.o
@@ -15,7 +15,7 @@ obj-$(CONFIG_MODULES) += module.o um_module.o
 USER_OBJS := ptrace_user.o sigcontext.o
 
 SYMLINKS = bitops.c csum-copy.S csum-partial.c csum-wrappers.c memcpy.S \
-	semaphore.c thunk.S module.c
+	thunk.S module.c
 
 include arch/um/scripts/Makefile.rules
 
@@ -24,17 +24,10 @@ csum-copy.S-dir = lib
 csum-partial.c-dir = lib
 csum-wrappers.c-dir = lib
 memcpy.S-dir = lib
-semaphore.c-dir = kernel
 thunk.S-dir = lib
 module.c-dir = kernel
 
-STUB_CFLAGS = -Wp,-MD,$(depfile) $(call unprofile,$(USER_CFLAGS))
-
-# _cflags works with kernel files, not with userspace ones, but c_flags does,
-# why ask why?
-$(obj)/stub_segv.o : c_flags = $(STUB_CFLAGS)
-
-$(obj)/stub.o : a_flags = $(STUB_CFLAGS)
+$(obj)/stub_segv.o: _c_flags = $(call unprofile,$(CFLAGS))
 
 subdir- := util
 
diff --git a/arch/um/sys-x86_64/kernel-offsets.c b/arch/um/sys-x86_64/kernel-offsets.c
index 220e875cbe2..998541eade4 100644
--- a/arch/um/sys-x86_64/kernel-offsets.c
+++ b/arch/um/sys-x86_64/kernel-offsets.c
@@ -2,6 +2,7 @@
 #include <linux/stddef.h>
 #include <linux/sched.h>
 #include <linux/time.h>
+#include <linux/elf.h>
 #include <asm/page.h>
 
 #define DEFINE(sym, val) \
diff --git a/arch/um/sys-x86_64/signal.c b/arch/um/sys-x86_64/signal.c
index 8fdaed06c10..fe1d065332b 100644
--- a/arch/um/sys-x86_64/signal.c
+++ b/arch/um/sys-x86_64/signal.c
@@ -104,28 +104,35 @@ int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate *to_fp,
 int copy_sc_from_user_tt(struct sigcontext *to, struct sigcontext *from,
                         int fpsize)
 {
-       struct _fpstate *to_fp, *from_fp;
-       unsigned long sigs;
-       int err;
-
-       to_fp = to->fpstate;
-       from_fp = from->fpstate;
-       sigs = to->oldmask;
-       err = copy_from_user(to, from, sizeof(*to));
-       to->oldmask = sigs;
-       return(err);
+	struct _fpstate *to_fp, *from_fp;
+	unsigned long sigs;
+	int err;
+
+	to_fp = to->fpstate;
+	sigs = to->oldmask;
+	err = copy_from_user(to, from, sizeof(*to));
+	from_fp = to->fpstate;
+	to->fpstate = to_fp;
+	to->oldmask = sigs;
+	if(to_fp != NULL)
+		err |= copy_from_user(to_fp, from_fp, fpsize);
+	return(err);
 }
 
 int copy_sc_to_user_tt(struct sigcontext *to, struct _fpstate *fp,
                       struct sigcontext *from, int fpsize)
 {
-       struct _fpstate *to_fp, *from_fp;
-       int err;
-
-       to_fp = (fp ? fp : (struct _fpstate *) (to + 1));
-       from_fp = from->fpstate;
-       err = copy_to_user(to, from, sizeof(*to));
-       return(err);
+	struct _fpstate *to_fp, *from_fp;
+	int err;
+
+	to_fp = (fp ? fp : (struct _fpstate *) (to + 1));
+	from_fp = from->fpstate;
+	err = copy_to_user(to, from, sizeof(*to));
+	if(from_fp != NULL){
+		err |= copy_to_user(&to->fpstate, &to_fp, sizeof(to->fpstate));
+		err |= copy_to_user(to_fp, from_fp, fpsize);
+	}
+	return(err);
 }
 
 #endif
diff --git a/arch/um/sys-x86_64/stub.S b/arch/um/sys-x86_64/stub.S
index 31c14925716..03c27973578 100644
--- a/arch/um/sys-x86_64/stub.S
+++ b/arch/um/sys-x86_64/stub.S
@@ -13,3 +13,54 @@ syscall_stub:
 	or	%rcx, %rbx
 	movq	%rax, (%rbx)
 	int3
+
+	.globl batch_syscall_stub
+batch_syscall_stub:
+	mov	$(UML_CONFIG_STUB_DATA >> 32), %rbx
+	sal	$32, %rbx
+	mov	$(UML_CONFIG_STUB_DATA & 0xffffffff), %rax
+	or	%rax, %rbx
+	/* load pointer to first operation */
+	mov	%rbx, %rsp
+	add	$0x10, %rsp
+again:
+	/* load length of additional data */
+	mov	0x0(%rsp), %rax
+
+	/* if(length == 0) : end of list */
+	/* write possible 0 to header */
+	mov	%rax, 8(%rbx)
+	cmp	$0, %rax
+	jz	done
+
+	/* save current pointer */
+	mov	%rsp, 8(%rbx)
+
+	/* skip additional data */
+	add	%rax, %rsp
+
+	/* load syscall-# */
+	pop	%rax
+
+	/* load syscall params */
+	pop	%rdi
+	pop	%rsi
+	pop	%rdx
+	pop	%r10
+ 	pop	%r8
+	pop	%r9
+
+	/* execute syscall */
+	syscall
+
+	/* check return value */
+	pop	%rcx
+	cmp	%rcx, %rax
+	je	again
+
+done:
+	/* save return value */
+	mov	%rax, (%rbx)
+
+	/* stop */
+	int3
diff --git a/arch/um/sys-x86_64/stub_segv.c b/arch/um/sys-x86_64/stub_segv.c
index 161d1fe9c03..65a131b362b 100644
--- a/arch/um/sys-x86_64/stub_segv.c
+++ b/arch/um/sys-x86_64/stub_segv.c
@@ -3,9 +3,10 @@
  * Licensed under the GPL
  */
 
-#include <signal.h>
+#include <asm/signal.h>
 #include <linux/compiler.h>
 #include <asm/unistd.h>
+#include <asm/ucontext.h>
 #include "uml-config.h"
 #include "sysdep/sigcontext.h"
 #include "sysdep/faultinfo.h"