110 files changed, 1586 insertions, 1890 deletions

diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index 55945db1313c..99e51d059a02 100644
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -68,6 +68,10 @@ config IRQ_RELEASE_METHOD
         bool
         default y
 
+config HZ
+        int
+        default 100
+
 menu "UML-specific options"
 
 config STATIC_LINK
@@ -95,23 +99,6 @@ config LD_SCRIPT_DYN
         default y
         depends on !LD_SCRIPT_STATIC
 
-config NET
-        bool "Networking support"
-        help
-          Unless you really know what you are doing, you should say Y here.
-          The reason is that some programs need kernel networking support even
-          when running on a stand-alone machine that isn't connected to any
-          other computer. If you are upgrading from an older kernel, you
-          should consider updating your networking tools too because changes
-          in the kernel and the tools often go hand in hand. The tools are
-          contained in the package net-tools, the location and version number
-          of which are given in <file:Documentation/Changes>.
-
-          For a general introduction to Linux networking, it is highly
-          recommended to read the NET-HOWTO, available from
-          <http://www.tldp.org/docs.html#howto>.
-
-
 source "fs/Kconfig.binfmt"
 
 config HOSTFS
@@ -145,7 +132,7 @@ config HPPFS
           by removing or changing anything in /proc which gives away the
           identity of a UML.
 
-          See <http://user-mode-linux.sf.net/hppfs.html> for more information.
+          See <http://user-mode-linux.sf.net/old/hppfs.html> for more information.
 
           You only need this if you are setting up a UML honeypot.  Otherwise,
           it is safe to say 'N' here.
@@ -189,8 +176,7 @@ config MAGIC_SYSRQ
 config SMP
         bool "Symmetric multi-processing support (EXPERIMENTAL)"
         default n
-        #SMP_BROKEN is for x86_64.
-        depends on EXPERIMENTAL && (!SMP_BROKEN || (BROKEN && SMP_BROKEN))
+        depends on BROKEN
         help
           This option enables UML SMP support.
           It is NOT related to having a real SMP box. Not directly, at least.
diff --git a/arch/um/Kconfig.char b/arch/um/Kconfig.char
index 9a78d354f0b4..3a4b396d7979 100644
--- a/arch/um/Kconfig.char
+++ b/arch/um/Kconfig.char
@@ -18,7 +18,7 @@ config SSL
           lines on the UML that are usually made to show up on the host as
           ttys or ptys.
 
-          See <http://user-mode-linux.sourceforge.net/input.html> for more
+          See <http://user-mode-linux.sourceforge.net/old/input.html> for more
           information and command line examples of how to use this facility.
 
           Unless you have a specific reason for disabling this, say Y.
diff --git a/arch/um/Kconfig.debug b/arch/um/Kconfig.debug
index 1f6462ffd3e8..8fce5e536b0f 100644
--- a/arch/um/Kconfig.debug
+++ b/arch/um/Kconfig.debug
@@ -4,12 +4,12 @@ source "lib/Kconfig.debug"
 
 config GPROF
         bool "Enable gprof support"
-        depends on DEBUG_INFO
+        depends on DEBUG_INFO && FRAME_POINTER
         help
           This allows profiling of a User-Mode Linux kernel with the gprof
           utility.
 
-          See <http://user-mode-linux.sourceforge.net/gprof.html> for more
+          See <http://user-mode-linux.sourceforge.net/old/gprof.html> for more
           details.
 
           If you're involved in UML kernel development and want to use gprof,
@@ -22,7 +22,7 @@ config GCOV
           This option allows developers to retrieve coverage data from a UML
           session.
 
-          See <http://user-mode-linux.sourceforge.net/gprof.html> for more
+          See <http://user-mode-linux.sourceforge.net/old/gprof.html> for more
           details.
 
           If you're involved in UML kernel development and want to use gcov,
diff --git a/arch/um/Kconfig.net b/arch/um/Kconfig.net
index 66e50026ade9..9e9a4aaa703d 100644
--- a/arch/um/Kconfig.net
+++ b/arch/um/Kconfig.net
@@ -14,7 +14,7 @@ config UML_NET
 
         For more information, including explanations of the networking and
         sample configurations, see
-        <http://user-mode-linux.sourceforge.net/networking.html>.
+        <http://user-mode-linux.sourceforge.net/old/networking.html>.
 
         If you'd like to be able to enable networking in the User-Mode
         linux environment, say Y; otherwise say N.  Note that you must
@@ -38,7 +38,7 @@ config UML_NET_ETHERTAP
         CONFIG_NETLINK_DEV configured as Y or M.
 
         For more information, see
-        <http://user-mode-linux.sourceforge.net/networking.html>  That site
+        <http://user-mode-linux.sourceforge.net/old/networking.html>  That site
         has examples of the UML command line to use to enable Ethertap
         networking.
 
@@ -72,7 +72,7 @@ config UML_NET_SLIP
         To use this, your host must support slip devices.
 
         For more information, see
-        <http://user-mode-linux.sourceforge.net/networking.html>.  That site
+        <http://user-mode-linux.sourceforge.net/old/networking.html>.
         has examples of the UML command line to use to enable slip
         networking, and details of a few quirks with it.
 
@@ -96,7 +96,7 @@ config UML_NET_DAEMON
         networking daemon on the host.
 
         For more information, see
-        <http://user-mode-linux.sourceforge.net/networking.html>  That site
+        <http://user-mode-linux.sourceforge.net/old/networking.html>  That site
         has examples of the UML command line to use to enable Daemon
         networking.
 
@@ -144,7 +144,7 @@ config UML_NET_MCAST
         To use this, your host kernel(s) must support IP Multicasting.
 
         For more information, see
-        <http://user-mode-linux.sourceforge.net/networking.html>  That site
+        <http://user-mode-linux.sourceforge.net/old/networking.html>  That site
         has examples of the UML command line to use to enable Multicast
         networking, and notes about the security of this approach.
 
@@ -165,7 +165,7 @@ config UML_NET_PCAP
         installed in order to build the pcap transport into UML.
 
         For more information, see
-        <http://user-mode-linux.sourceforge.net/networking.html>  That site
+        <http://user-mode-linux.sourceforge.net/old/networking.html>  That site
         has examples of the UML command line to use to enable this option.
 
         If you intend to use UML as a network monitor for the host, say
diff --git a/arch/um/Makefile b/arch/um/Makefile
index ba6813a4aa37..cb4af9bf2074 100644
--- a/arch/um/Makefile
+++ b/arch/um/Makefile
@@ -49,7 +49,7 @@ SYS_DIR		:= $(ARCH_DIR)/include/sysdep-$(SUBARCH)
 #
 # These apply to USER_CFLAGS to.
 
-KBUILD_CFLAGS += $(CFLAGS-y) -D__arch_um__ -DSUBARCH=\"$(SUBARCH)\"     \
+KBUILD_CFLAGS += $(CFLAGS) $(CFLAGS-y) -D__arch_um__ -DSUBARCH=\"$(SUBARCH)\" \
         $(ARCH_INCLUDE) $(MODE_INCLUDE) -Dvmap=kernel_vmap      \
         -Din6addr_loopback=kernel_in6addr_loopback \
         -Din6addr_any=kernel_in6addr_any
@@ -58,7 +58,7 @@ KBUILD_AFLAGS += $(ARCH_INCLUDE)
 
 USER_CFLAGS = $(patsubst $(KERNEL_DEFINES),,$(patsubst -D__KERNEL__,,\
         $(patsubst -I%,,$(KBUILD_CFLAGS)))) $(ARCH_INCLUDE) $(MODE_INCLUDE) \
-        -D_FILE_OFFSET_BITS=64
+        $(filter -I%,$(CFLAGS)) -D_FILE_OFFSET_BITS=64
 
 include $(srctree)/$(ARCH_DIR)/Makefile-$(SUBARCH)
 
@@ -130,7 +130,9 @@ CPPFLAGS_vmlinux.lds = -U$(SUBARCH) -DSTART=$(START) -DELF_ARCH=$(ELF_ARCH) \
 # The wrappers will select whether using "malloc" or the kernel allocator.
 LINK_WRAPS = -Wl,--wrap,malloc -Wl,--wrap,free -Wl,--wrap,calloc
 
-CFLAGS_vmlinux := $(LINK-y) $(LINK_WRAPS)
+LD_FLAGS_CMDLINE = $(foreach opt,$(LDFLAGS),-Wl,$(opt))
+
+CFLAGS_vmlinux := $(LINK-y) $(LINK_WRAPS) $(LD_FLAGS_CMDLINE)
 define cmd_vmlinux__
         $(CC) $(CFLAGS_vmlinux) -o $@ \
         -Wl,-T,$(vmlinux-lds) $(vmlinux-init) \
@@ -158,7 +160,7 @@ ifneq ($(KBUILD_SRC),)
         $(Q)mkdir -p $(objtree)/include/asm-um
         $(Q)ln -fsn $(srctree)/include/asm-um/$(basename $(notdir $@))-$(SUBARCH)$(suffix $@) $@
 else
-        $(Q)cd $(TOPDIR)/$(dir $@) ; \
+        $(Q)cd $(srctree)/$(dir $@) ; \
         ln -sf $(basename $(notdir $@))-$(SUBARCH)$(suffix $@) $(notdir $@)
 endif
 
@@ -168,7 +170,7 @@ ifneq ($(KBUILD_SRC),)
         $(Q)mkdir -p $(objtree)/include/asm-um
         $(Q)ln -fsn $(srctree)/include/asm-$(HEADER_ARCH) include/asm-um/arch
 else
-        $(Q)cd $(TOPDIR)/include/asm-um && ln -fsn ../asm-$(HEADER_ARCH) arch
+        $(Q)cd $(srctree)/include/asm-um && ln -fsn ../asm-$(HEADER_ARCH) arch
 endif
 
 $(objtree)/$(ARCH_DIR)/include:
diff --git a/arch/um/Makefile-tt b/arch/um/Makefile-tt
deleted file mode 100644
index 03f7b10cfd0b..000000000000
--- a/arch/um/Makefile-tt
+++ /dev/null
@@ -1,5 +0,0 @@
-# 
-# Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
-# Licensed under the GPL
-#
-
diff --git a/arch/um/defconfig b/arch/um/defconfig
index f609edede065..86db2862f222 100644
--- a/arch/um/defconfig
+++ b/arch/um/defconfig
@@ -77,7 +77,7 @@ CONFIG_LD_SCRIPT_DYN=y
 CONFIG_NET=y
 CONFIG_BINFMT_ELF=y
 CONFIG_BINFMT_MISC=m
-# CONFIG_HOSTFS is not set
+CONFIG_HOSTFS=y
 # CONFIG_HPPFS is not set
 CONFIG_MCONSOLE=y
 CONFIG_MAGIC_SYSRQ=y
@@ -188,7 +188,7 @@ CONFIG_CON_CHAN="xterm"
 CONFIG_SSL_CHAN="pts"
 CONFIG_UNIX98_PTYS=y
 CONFIG_LEGACY_PTYS=y
-CONFIG_LEGACY_PTY_COUNT=256
+CONFIG_LEGACY_PTY_COUNT=32
 # CONFIG_WATCHDOG is not set
 CONFIG_UML_SOUND=m
 CONFIG_SOUND=m
@@ -508,7 +508,7 @@ CONFIG_DEBUG_KERNEL=y
 CONFIG_LOG_BUF_SHIFT=14
 CONFIG_DETECT_SOFTLOCKUP=y
 # CONFIG_SCHEDSTATS is not set
-CONFIG_DEBUG_SLAB=y
+# CONFIG_DEBUG_SLAB is not set
 # CONFIG_DEBUG_SLAB_LEAK is not set
 # CONFIG_DEBUG_MUTEXES is not set
 # CONFIG_DEBUG_SPINLOCK is not set
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 83bf15a3dda8..2c898c4d6b6a 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -8,6 +8,7 @@
 #include "chan_kern.h"
 #include "irq_kern.h"
 #include "irq_user.h"
+#include "kern_util.h"
 #include "os.h"
 
 #define LINE_BUFSIZE 4096
@@ -48,7 +49,7 @@ static int write_room(struct line *line)
         n = line->head - line->tail;
 
         if (n <= 0)
-                n = LINE_BUFSIZE + n; /* The other case */
+                n += LINE_BUFSIZE; /* The other case */
         return n - 1;
 }
 
@@ -58,17 +59,10 @@ int line_write_room(struct tty_struct *tty)
         unsigned long flags;
         int room;
 
-        if (tty->stopped)
-                return 0;
-
         spin_lock_irqsave(&line->lock, flags);
         room = write_room(line);
         spin_unlock_irqrestore(&line->lock, flags);
 
-        /*XXX: Warning to remove */
-        if (0 == room)
-                printk(KERN_DEBUG "%s: %s: no room left in buffer\n",
-                       __FUNCTION__,tty->name);
         return room;
 }
 
@@ -79,8 +73,7 @@ int line_chars_in_buffer(struct tty_struct *tty)
         int ret;
 
         spin_lock_irqsave(&line->lock, flags);
-
-        /*write_room subtracts 1 for the needed NULL, so we readd it.*/
+        /* write_room subtracts 1 for the needed NULL, so we readd it.*/
         ret = LINE_BUFSIZE - (write_room(line) + 1);
         spin_unlock_irqrestore(&line->lock, flags);
 
@@ -184,10 +177,6 @@ void line_flush_buffer(struct tty_struct *tty)
         unsigned long flags;
         int err;
 
-        /*XXX: copied from line_write, verify if it is correct!*/
-        if (tty->stopped)
-                return;
-
         spin_lock_irqsave(&line->lock, flags);
         err = flush_buffer(line);
         spin_unlock_irqrestore(&line->lock, flags);
@@ -213,9 +202,6 @@ int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
         unsigned long flags;
         int n, ret = 0;
 
-        if (tty->stopped)
-                return 0;
-
         spin_lock_irqsave(&line->lock, flags);
         if (line->head != line->tail)
                 ret = buffer_data(line, buf, len);
@@ -788,9 +774,11 @@ static irqreturn_t winch_interrupt(int irq, void *data)
         tty = winch->tty;
         if (tty != NULL) {
                 line = tty->driver_data;
-                chan_window_size(&line->chan_list, &tty->winsize.ws_row,
-                                 &tty->winsize.ws_col);
-                kill_pgrp(tty->pgrp, SIGWINCH, 1);
+                if (line != NULL) {
+                        chan_window_size(&line->chan_list, &tty->winsize.ws_row,
+                                         &tty->winsize.ws_col);
+                        kill_pgrp(tty->pgrp, SIGWINCH, 1);
+                }
         }
  out:
         if (winch->fd != -1)
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 0f3c7d14a6e3..ebb265c07e4d 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -1,23 +1,25 @@
 /*
  * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org)
- * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Copyright (C) 2001 - 2008 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
-#include "linux/console.h"
-#include "linux/ctype.h"
-#include "linux/interrupt.h"
-#include "linux/list.h"
-#include "linux/mm.h"
-#include "linux/module.h"
-#include "linux/notifier.h"
-#include "linux/reboot.h"
-#include "linux/proc_fs.h"
-#include "linux/slab.h"
-#include "linux/syscalls.h"
-#include "linux/utsname.h"
-#include "linux/workqueue.h"
-#include "asm/uaccess.h"
+#include <linux/console.h>
+#include <linux/ctype.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/proc_fs.h>
+#include <linux/slab.h>
+#include <linux/syscalls.h>
+#include <linux/utsname.h>
+#include <linux/workqueue.h>
+#include <linux/mutex.h>
+#include <asm/uaccess.h>
+
 #include "init.h"
 #include "irq_kern.h"
 #include "irq_user.h"
@@ -305,7 +307,9 @@ void mconsole_stop(struct mc_request *req)
         deactivate_fd(req->originating_fd, MCONSOLE_IRQ);
         os_set_fd_block(req->originating_fd, 1);
         mconsole_reply(req, "stopped", 0, 0);
-        while (mconsole_get_request(req->originating_fd, req)) {
+        for (;;) {
+                if (!mconsole_get_request(req->originating_fd, req))
+                        continue;
                 if (req->cmd->handler == mconsole_go)
                         break;
                 if (req->cmd->handler == mconsole_stop) {
@@ -358,7 +362,7 @@ struct unplugged_pages {
         void *pages[UNPLUGGED_PER_PAGE];
 };
 
-static DECLARE_MUTEX(plug_mem_mutex);
+static DEFINE_MUTEX(plug_mem_mutex);
 static unsigned long long unplugged_pages_count = 0;
 static LIST_HEAD(unplugged_pages);
 static int unplug_index = UNPLUGGED_PER_PAGE;
@@ -394,7 +398,7 @@ static int mem_config(char *str, char **error_out)
 
         diff /= PAGE_SIZE;
 
-        down(&plug_mem_mutex);
+        mutex_lock(&plug_mem_mutex);
         for (i = 0; i < diff; i++) {
                 struct unplugged_pages *unplugged;
                 void *addr;
@@ -451,7 +455,7 @@ static int mem_config(char *str, char **error_out)
 
         err = 0;
 out_unlock:
-        up(&plug_mem_mutex);
+        mutex_unlock(&plug_mem_mutex);
 out:
         return err;
 }
@@ -741,7 +745,6 @@ void mconsole_stack(struct mc_request *req)
 {
         char *ptr = req->request.data;
         int pid_requested= -1;
-        struct task_struct *from = NULL;
         struct task_struct *to = NULL;
 
         /*
@@ -763,9 +766,7 @@ void mconsole_stack(struct mc_request *req)
                 return;
         }
 
-        from = current;
-
-        to = find_task_by_pid(pid_requested);
+        to = find_task_by_pid_ns(pid_requested, &init_pid_ns);
         if ((to == NULL) || (pid_requested == 0)) {
                 mconsole_reply(req, "Couldn't find that pid", 1, 0);
                 return;
@@ -795,6 +796,8 @@ static int __init mconsole_init(void)
                 printk(KERN_ERR "Failed to initialize management console\n");
                 return 1;
         }
+        if (os_set_fd_block(sock, 0))
+                goto out;
 
         register_reboot_notifier(&reboot_notifier);
 
@@ -803,7 +806,7 @@ static int __init mconsole_init(void)
                              "mconsole", (void *)sock);
         if (err) {
                 printk(KERN_ERR "Failed to get IRQ for management console\n");
-                return 1;
+                goto out;
         }
 
         if (notify_socket != NULL) {
@@ -819,6 +822,10 @@ static int __init mconsole_init(void)
         printk(KERN_INFO "mconsole (version %d) initialized on %s\n",
                MCONSOLE_VERSION, mconsole_socket_name);
         return 0;
+
+ out:
+        os_close_file(sock);
+        return 1;
 }
 
 __initcall(mconsole_init);
diff --git a/arch/um/drivers/mconsole_user.c b/arch/um/drivers/mconsole_user.c
index 430c024a19b0..13af2f03ed84 100644
--- a/arch/um/drivers/mconsole_user.c
+++ b/arch/um/drivers/mconsole_user.c
@@ -83,9 +83,8 @@ int mconsole_get_request(int fd, struct mc_request *req)
         int len;
 
         req->originlen = sizeof(req->origin);
-        req->len = recvfrom(fd, &req->request, sizeof(req->request),
-                            MSG_DONTWAIT, (struct sockaddr *) req->origin,
-                            &req->originlen);
+        req->len = recvfrom(fd, &req->request, sizeof(req->request), 0,
+                            (struct sockaddr *) req->origin, &req->originlen);
         if (req->len < 0)
                 return 0;
 
diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
index 3c6c44ca1ffa..1e8f41a99511 100644
--- a/arch/um/drivers/net_kern.c
+++ b/arch/um/drivers/net_kern.c
@@ -318,7 +318,7 @@ static void setup_etheraddr(char *str, unsigned char *addr, char *name)
         if (str == NULL)
                 goto random;
 
-        for (i = 0;i < 6; i++) {
+        for (i = 0; i < 6; i++) {
                 addr[i] = simple_strtoul(str, &end, 16);
                 if ((end == str) ||
                    ((*end != ':') && (*end != ',') && (*end != '\0'))) {
@@ -343,14 +343,13 @@ static void setup_etheraddr(char *str, unsigned char *addr, char *name)
         }
         if (!is_local_ether_addr(addr)) {
                 printk(KERN_WARNING
-                       "Warning: attempt to assign a globally valid ethernet "
+                       "Warning: Assigning a globally valid ethernet "
                        "address to a device\n");
-                printk(KERN_WARNING "You should better enable the 2nd "
-                       "rightmost bit in the first byte of the MAC,\n");
+                printk(KERN_WARNING "You should set the 2nd rightmost bit in "
+                       "the first byte of the MAC,\n");
                 printk(KERN_WARNING "i.e. %02x:%02x:%02x:%02x:%02x:%02x\n",
                        addr[0] | 0x02, addr[1], addr[2], addr[3], addr[4],
                        addr[5]);
-                goto random;
         }
         return;
 
@@ -368,7 +367,6 @@ static struct platform_driver uml_net_driver = {
                 .name  = DRIVER_NAME,
         },
 };
-static int driver_registered;
 
 static void net_device_release(struct device *dev)
 {
@@ -383,6 +381,12 @@ static void net_device_release(struct device *dev)
         free_netdev(netdev);
 }
 
+/*
+ * Ensures that platform_driver_register is called only once by
+ * eth_configure.  Will be set in an initcall.
+ */
+static int driver_registered;
+
 static void eth_configure(int n, void *init, char *mac,
                           struct transport *transport)
 {
diff --git a/arch/um/drivers/net_user.c b/arch/um/drivers/net_user.c
index 29185cad9fff..abf2653f5517 100644
--- a/arch/um/drivers/net_user.c
+++ b/arch/um/drivers/net_user.c
@@ -201,7 +201,7 @@ static int change_tramp(char **argv, char *output, int output_len)
         close(fds[1]);
 
         if (pid > 0)
-                helper_wait(pid, 0, "change_tramp");
+                helper_wait(pid);
         return pid;
 }
 
diff --git a/arch/um/drivers/port_kern.c b/arch/um/drivers/port_kern.c
index 330543b3129b..19930081d3d8 100644
--- a/arch/um/drivers/port_kern.c
+++ b/arch/um/drivers/port_kern.c
@@ -6,6 +6,7 @@
 #include "linux/completion.h"
 #include "linux/interrupt.h"
 #include "linux/list.h"
+#include "linux/mutex.h"
 #include "asm/atomic.h"
 #include "init.h"
 #include "irq_kern.h"
@@ -120,7 +121,7 @@ static int port_accept(struct port_list *port)
         return 0;
 }
 
-static DECLARE_MUTEX(ports_sem);
+static DEFINE_MUTEX(ports_mutex);
 static LIST_HEAD(ports);
 
 static void port_work_proc(struct work_struct *unused)
@@ -161,7 +162,7 @@ void *port_data(int port_num)
         struct port_dev *dev = NULL;
         int fd;
 
-        down(&ports_sem);
+        mutex_lock(&ports_mutex);
         list_for_each(ele, &ports) {
                 port = list_entry(ele, struct port_list, list);
                 if (port->port == port_num)
@@ -216,7 +217,7 @@ void *port_data(int port_num)
  out_free:
         kfree(port);
  out:
-        up(&ports_sem);
+        mutex_unlock(&ports_mutex);
         return dev;
 }
 
diff --git a/arch/um/drivers/random.c b/arch/um/drivers/random.c
index e942e836f995..71f0959c1535 100644
--- a/arch/um/drivers/random.c
+++ b/arch/um/drivers/random.c
@@ -5,6 +5,7 @@
  * This software may be used and distributed according to the terms
  * of the GNU General Public License, incorporated herein by reference.
  */
+#include <linux/sched.h>
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/miscdevice.h>
diff --git a/arch/um/drivers/slip_user.c b/arch/um/drivers/slip_user.c
index b8711e50da80..8b80505a3fb0 100644
--- a/arch/um/drivers/slip_user.c
+++ b/arch/um/drivers/slip_user.c
@@ -109,7 +109,7 @@ static int slip_tramp(char **argv, int fd)
         read_output(fds[0], output, output_len);
         printk("%s", output);
 
-        err = helper_wait(pid, 0, argv[0]);
+        err = helper_wait(pid);
         close(fds[0]);
 
 out_free:
diff --git a/arch/um/drivers/slirp_user.c b/arch/um/drivers/slirp_user.c
index 89c1be225fda..a0ada8fec72a 100644
--- a/arch/um/drivers/slirp_user.c
+++ b/arch/um/drivers/slirp_user.c
@@ -98,7 +98,7 @@ static void slirp_close(int fd, void *data)
                        "(%d)\n", pri->pid, errno);
         }
 #endif
-        err = helper_wait(pri->pid, 1, "slirp_close");
+        err = helper_wait(pri->pid);
         if (err < 0)
                 return;
 
diff --git a/arch/um/drivers/ssl.c b/arch/um/drivers/ssl.c
index 875d60d0c6a2..f1786e64607f 100644
--- a/arch/um/drivers/ssl.c
+++ b/arch/um/drivers/ssl.c
@@ -15,7 +15,6 @@
 #include "line.h"
 #include "ssl.h"
 #include "chan_kern.h"
-#include "kern_util.h"
 #include "kern.h"
 #include "init.h"
 #include "irq_user.h"
diff --git a/arch/um/drivers/stdio_console.c b/arch/um/drivers/stdio_console.c
index 656036e90b19..cec0c33cdd39 100644
--- a/arch/um/drivers/stdio_console.c
+++ b/arch/um/drivers/stdio_console.c
@@ -22,7 +22,6 @@
 #include "stdio_console.h"
 #include "line.h"
 #include "chan_kern.h"
-#include "kern_util.h"
 #include "irq_user.h"
 #include "mconsole_kern.h"
 #include "init.h"
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 99f9f9605e9c..be3a2797dac4 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -49,6 +49,7 @@
 #include "irq_user.h"
 #include "irq_kern.h"
 #include "ubd_user.h"
+#include "kern_util.h"
 #include "os.h"
 #include "mem.h"
 #include "mem_kern.h"
@@ -229,7 +230,7 @@ static int proc_ide_read_media(char *page, char **start, off_t off, int count,
         return len;
 }
 
-static void make_ide_entries(char *dev_name)
+static void make_ide_entries(const char *dev_name)
 {
         struct proc_dir_entry *dir, *ent;
         char name[64];
@@ -244,7 +245,7 @@ static void make_ide_entries(char *dev_name)
         ent->data = NULL;
         ent->read_proc = proc_ide_read_media;
         ent->write_proc = NULL;
-        sprintf(name,"ide0/%s", dev_name);
+        snprintf(name, sizeof(name), "ide0/%s", dev_name);
         proc_symlink(dev_name, proc_ide_root, name);
 }
 
@@ -437,7 +438,10 @@ __uml_help(ubd_setup,
 "    machine by running 'dd' on the device. <n> must be in the range\n"
 "    0 to 7. Appending an 'r' to the number will cause that device\n"
 "    to be mounted read-only. For example ubd1r=./ext_fs. Appending\n"
-"    an 's' will cause data to be written to disk on the host immediately.\n\n"
+"    an 's' will cause data to be written to disk on the host immediately.\n"
+"    'c' will cause the device to be treated as being shared between multiple\n"
+"    UMLs and file locking will be turned off - this is appropriate for a\n"
+"    cluster filesystem and inappropriate at almost all other times.\n\n"
 );
 
 static int udb_setup(char *str)
@@ -456,20 +460,6 @@ __uml_help(udb_setup,
 "    in the boot output.\n\n"
 );
 
-static int fakehd_set = 0;
-static int fakehd(char *str)
-{
-        printk(KERN_INFO "fakehd : Changing ubd name to \"hd\".\n");
-        fakehd_set = 1;
-        return 1;
-}
-
-__setup("fakehd", fakehd);
-__uml_help(fakehd,
-"fakehd\n"
-"    Change the ubd device name to \"hd\".\n\n"
-);
-
 static void do_ubd_request(struct request_queue * q);
 
 /* Only changed by ubd_init, which is an initcall. */
@@ -718,8 +708,10 @@ static int ubd_add(int n, char **error_out)
                 ubd_disk_register(fake_major, ubd_dev->size, n,
                                   &fake_gendisk[n]);
 
-        /* perhaps this should also be under the "if (fake_major)" above */
-        /* using the fake_disk->disk_name and also the fakehd_set name */
+        /*
+         * Perhaps this should also be under the "if (fake_major)" above
+         * using the fake_disk->disk_name
+         */
         if (fake_ide)
                 make_ide_entries(ubd_gendisk[n]->disk_name);
 
diff --git a/arch/um/drivers/ubd_user.c b/arch/um/drivers/ubd_user.c
index 48fc7452bc1d..b591bb9c41dd 100644
--- a/arch/um/drivers/ubd_user.c
+++ b/arch/um/drivers/ubd_user.c
@@ -16,7 +16,6 @@
 #include <sys/mman.h>
 #include <sys/param.h>
 #include "asm/types.h"
-#include "kern_util.h"
 #include "user.h"
 #include "ubd_user.h"
 #include "os.h"
diff --git a/arch/um/drivers/vde_user.c b/arch/um/drivers/vde_user.c
index d9941fe5f931..56533db25343 100644
--- a/arch/um/drivers/vde_user.c
+++ b/arch/um/drivers/vde_user.c
@@ -80,7 +80,7 @@ void vde_init_libstuff(struct vde_data *vpri, struct vde_init *init)
 
         vpri->args = kmalloc(sizeof(struct vde_open_args), UM_GFP_KERNEL);
         if (vpri->args == NULL) {
-                printk(UM_KERN_ERR "vde_init_libstuff - vde_open_args"
+                printk(UM_KERN_ERR "vde_init_libstuff - vde_open_args "
                        "allocation failed");
                 return;
         }
diff --git a/arch/um/include/arch.h b/arch/um/include/arch.h
index 49c601ff2bac..2de92a08a76b 100644
--- a/arch/um/include/arch.h
+++ b/arch/um/include/arch.h
@@ -10,6 +10,6 @@
 
 extern void arch_check_bugs(void);
 extern int arch_fixup(unsigned long address, struct uml_pt_regs *regs);
-extern int arch_handle_signal(int sig, struct uml_pt_regs *regs);
+extern void arch_examine_signal(int sig, struct uml_pt_regs *regs);
 
 #endif
diff --git a/arch/um/include/as-layout.h b/arch/um/include/as-layout.h
index a5cdf953e04a..606bb5c7fdf6 100644
--- a/arch/um/include/as-layout.h
+++ b/arch/um/include/as-layout.h
@@ -10,23 +10,31 @@
 #include "kern_constants.h"
 
 /*
- * Assembly doesn't want any casting, but C does, so define these
- * without casts here, and define new symbols with casts inside the C
- * section.
+ * Stolen from linux/const.h, which can't be directly included since
+ * this is used in userspace code, which has no access to the kernel
+ * headers.  Changed to be suitable for adding casts to the start,
+ * rather than "UL" to the end.
  */
-#define ASM_STUB_CODE (UML_CONFIG_TOP_ADDR - 2 * UM_KERN_PAGE_SIZE)
-#define ASM_STUB_DATA (UML_CONFIG_TOP_ADDR - UM_KERN_PAGE_SIZE)
-#define ASM_STUB_START ASM_STUB_CODE
 
-/*
- * This file is included by the assembly stubs, which just want the
- * definitions above.
+/* Some constant macros are used in both assembler and
+ * C code.  Therefore we cannot annotate them always with
+ * 'UL' and other type specifiers unilaterally.  We
+ * use the following macros to deal with this.
  */
-#ifndef __ASSEMBLY__
 
-#define STUB_CODE ((unsigned long) ASM_STUB_CODE)
-#define STUB_DATA ((unsigned long) ASM_STUB_DATA)
-#define STUB_START ((unsigned long) ASM_STUB_START)
+#ifdef __ASSEMBLY__
+#define _AC(X, Y)       (Y)
+#else
+#define __AC(X, Y)      (X (Y))
+#define _AC(X, Y)       __AC(X, Y)
+#endif
+
+#define STUB_START _AC(, 0x100000)
+#define STUB_CODE _AC((unsigned long), STUB_START)
+#define STUB_DATA _AC((unsigned long), STUB_CODE + UM_KERN_PAGE_SIZE)
+#define STUB_END _AC((unsigned long), STUB_DATA + UM_KERN_PAGE_SIZE)
+
+#ifndef __ASSEMBLY__
 
 #include "sysdep/ptrace.h"
 
diff --git a/arch/um/include/chan_user.h b/arch/um/include/chan_user.h
index 5a2263e05bb2..9b9ced85b703 100644
--- a/arch/um/include/chan_user.h
+++ b/arch/um/include/chan_user.h
@@ -48,7 +48,7 @@ extern void register_winch_irq(int fd, int tty_fd, int pid,
 #define __channel_help(fn, prefix) \
 __uml_help(fn, prefix "[0-9]*=<channel description>\n" \
 "    Attach a console or serial line to a host channel.  See\n" \
-"    http://user-mode-linux.sourceforge.net/input.html for a complete\n" \
+"    http://user-mode-linux.sourceforge.net/old/input.html for a complete\n" \
 "    description of this switch.\n\n" \
 );
 
diff --git a/arch/um/include/common-offsets.h b/arch/um/include/common-offsets.h
index 0edab695ed4e..b54bd35585c2 100644
--- a/arch/um/include/common-offsets.h
+++ b/arch/um/include/common-offsets.h
@@ -18,6 +18,7 @@ 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_STR(UM_KERN_CONT, KERN_CONT);
 
 DEFINE(UM_ELF_CLASS, ELF_CLASS);
 DEFINE(UM_ELFCLASS32, ELFCLASS32);
diff --git a/arch/um/include/init.h b/arch/um/include/init.h
index cebc6cae9190..b00a95741d41 100644
--- a/arch/um/include/init.h
+++ b/arch/um/include/init.h
@@ -40,6 +40,20 @@
 typedef int (*initcall_t)(void);
 typedef void (*exitcall_t)(void);
 
+#ifndef __KERNEL__
+#ifndef __section
+# define __section(S) __attribute__ ((__section__(#S)))
+#endif
+
+#if __GNUC_MINOR__ >= 3
+# define __used                 __attribute__((__used__))
+#else
+# define __used                 __attribute__((__unused__))
+#endif
+
+#else
+#include <linux/compiler.h>
+#endif
 /* These are for everybody (although not all archs will actually
    discard it in modules) */
 #define __init          __section(.init.text)
@@ -127,14 +141,3 @@ extern struct uml_param __uml_setup_start, __uml_setup_end;
 #endif
 
 #endif /* _LINUX_UML_INIT_H */
-
-/*
- * 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/irq_user.h b/arch/um/include/irq_user.h
index 884a9c17eea0..e60b31873de1 100644
--- a/arch/um/include/irq_user.h
+++ b/arch/um/include/irq_user.h
@@ -14,7 +14,6 @@ struct irq_fd {
         int fd;
         int type;
         int irq;
-        int pid;
         int events;
         int current_events;
 };
diff --git a/arch/um/include/kern_util.h b/arch/um/include/kern_util.h
index 74ce8e5370a6..3c341222d252 100644
--- a/arch/um/include/kern_util.h
+++ b/arch/um/include/kern_util.h
@@ -9,107 +9,61 @@
 #include "sysdep/ptrace.h"
 #include "sysdep/faultinfo.h"
 
-typedef void (*kern_hndl)(int, struct uml_pt_regs *);
-
-struct kern_handlers {
-        kern_hndl relay_signal;
-        kern_hndl winch;
-        kern_hndl bus_handler;
-        kern_hndl page_fault;
-        kern_hndl sigio_handler;
-        kern_hndl timer_handler;
-};
-
-extern const struct kern_handlers handlinfo_kern;
+extern int uml_exitcode;
 
 extern int ncpus;
-extern char *gdb_init;
 extern int kmalloc_ok;
-extern int jail;
-extern int nsyscalls;
 
-#define UML_ROUND_DOWN(addr) ((void *)(((unsigned long) addr) & PAGE_MASK))
 #define UML_ROUND_UP(addr) \
-        UML_ROUND_DOWN(((unsigned long) addr) + PAGE_SIZE - 1)
+        ((((unsigned long) addr) + PAGE_SIZE - 1) & PAGE_MASK)
 
-extern int kernel_fork(unsigned long flags, int (*fn)(void *), void * arg);
-extern int kernel_thread_proc(void *data);
-extern void syscall_segv(int sig);
-extern int current_pid(void);
 extern unsigned long alloc_stack(int order, int atomic);
+extern void free_stack(unsigned long stack, int order);
+
 extern int do_signal(void);
-extern int is_stack_fault(unsigned long sp);
+extern void copy_sc(struct uml_pt_regs *regs, void *from);
+extern void interrupt_end(void);
+extern void relay_signal(int sig, struct uml_pt_regs *regs);
+
 extern unsigned long segv(struct faultinfo fi, unsigned long ip,
                           int is_user, struct uml_pt_regs *regs);
 extern int handle_page_fault(unsigned long address, unsigned long ip,
                              int is_write, int is_user, int *code_out);
-extern void syscall_ready(void);
-extern void set_tracing(void *t, int tracing);
-extern int is_tracing(void *task);
-extern int segv_syscall(void);
-extern void kern_finish_exec(void *task, int new_pid, unsigned long stack);
-extern unsigned long page_mask(void);
-extern int need_finish_fork(void);
-extern void free_stack(unsigned long stack, int order);
-extern void add_input_request(int op, void (*proc)(int), void *arg);
-extern char *current_cmd(void);
-extern void timer_handler(int sig, struct uml_pt_regs *regs);
-extern int set_signals(int enable);
-extern int pid_to_processor_id(int pid);
-extern void deliver_signals(void *t);
-extern int next_trap_index(int max);
-extern void default_idle(void);
-extern void finish_fork(void);
-extern void paging_init(void);
-extern void init_flush_vm(void);
-extern void *syscall_sp(void *t);
-extern void syscall_trace(struct uml_pt_regs *regs, int entryexit);
+
 extern unsigned int do_IRQ(int irq, struct uml_pt_regs *regs);
-extern void interrupt_end(void);
-extern void initial_thread_cb(void (*proc)(void *), void *arg);
-extern int debugger_signal(int status, int pid);
-extern void debugger_parent_signal(int status, int pid);
-extern void child_signal(int pid, int status);
-extern int init_ptrace_proxy(int idle_pid, int startup, int stop);
-extern int init_parent_proxy(int pid);
-extern int singlestepping(void *t);
-extern void check_stack_overflow(void *ptr);
-extern void relay_signal(int sig, struct uml_pt_regs *regs);
-extern int user_context(unsigned long sp);
-extern void timer_irq(struct uml_pt_regs *regs);
-extern void do_uml_exitcalls(void);
-extern int attach_debugger(int idle_pid, int pid, int stop);
-extern int config_gdb(char *str);
-extern int remove_gdb(void);
-extern char *uml_strdup(char *string);
-extern void unprotect_kernel_mem(void);
-extern void protect_kernel_mem(void);
-extern void uml_cleanup(void);
-extern void lock_signalled_task(void *t);
-extern void IPI_handler(int cpu);
-extern int jail_setup(char *line, int *add);
-extern void *get_init_task(void);
-extern int clear_user_proc(void *buf, int size);
-extern int copy_to_user_proc(void *to, void *from, int size);
-extern int copy_from_user_proc(void *to, void *from, int size);
-extern int strlen_user_proc(char *str);
-extern long execute_syscall(void *r);
 extern int smp_sigio_handler(void);
-extern void *get_current(void);
-extern struct task_struct *get_task(int pid, int require);
-extern void machine_halt(void);
+extern void initial_thread_cb(void (*proc)(void *), void *arg);
 extern int is_syscall(unsigned long addr);
+extern void timer_handler(int sig, struct uml_pt_regs *regs);
 
-extern void free_irq(unsigned int, void *);
-extern int cpu(void);
+extern void timer_handler(int sig, struct uml_pt_regs *regs);
 
-extern void time_init_kern(void);
+extern int start_uml(void);
+extern void paging_init(void);
 
-/* Are we disallowed to sleep? Used to choose between GFP_KERNEL and GFP_ATOMIC. */
+extern void uml_cleanup(void);
+extern void do_uml_exitcalls(void);
+
+/*
+ * Are we disallowed to sleep? Used to choose between GFP_KERNEL and
+ * GFP_ATOMIC.
+ */
 extern int __cant_sleep(void);
-extern void sigio_handler(int sig, struct uml_pt_regs *regs);
-extern void copy_sc(struct uml_pt_regs *regs, void *from);
+extern void *get_current(void);
+extern int copy_from_user_proc(void *to, void *from, int size);
+extern int cpu(void);
+extern char *uml_strdup(const char *string);
+
 extern unsigned long to_irq_stack(unsigned long *mask_out);
-unsigned long from_irq_stack(int nested);
-extern int start_uml(void);
+extern unsigned long from_irq_stack(int nested);
+
+extern void syscall_trace(struct uml_pt_regs *regs, int entryexit);
+extern int singlestepping(void *t);
+
+extern void segv_handler(int sig, struct uml_pt_regs *regs);
+extern void bus_handler(int sig, struct uml_pt_regs *regs);
+extern void winch(int sig, struct uml_pt_regs *regs);
+extern void fatal_sigsegv(void) __attribute__ ((noreturn));
+
+
 #endif
diff --git a/arch/um/include/mem_user.h b/arch/um/include/mem_user.h
index a54514d2cc3a..46384acd547b 100644
--- a/arch/um/include/mem_user.h
+++ b/arch/um/include/mem_user.h
@@ -46,9 +46,6 @@ extern int iomem_size;
 
 #define ROUND_4M(n) ((((unsigned long) (n)) + (1 << 22)) & ~((1 << 22) - 1))
 
-extern unsigned long host_task_size;
-extern unsigned long task_size;
-
 extern int init_mem_user(void);
 extern void setup_memory(void *entry);
 extern unsigned long find_iomem(char *driver, unsigned long *len_out);
@@ -59,9 +56,7 @@ extern void setup_physmem(unsigned long start, unsigned long usable,
                           unsigned long len, unsigned long long highmem);
 extern void add_iomem(char *name, int fd, unsigned long size);
 extern unsigned long phys_offset(unsigned long phys);
-extern void unmap_physmem(void);
 extern void map_memory(unsigned long virt, unsigned long phys,
                        unsigned long len, int r, int w, int x);
-extern unsigned long get_kmem_end(void);
 
 #endif
diff --git a/arch/um/include/misc_constants.h b/arch/um/include/misc_constants.h
deleted file mode 100644
index 989bc08de36e..000000000000
--- a/arch/um/include/misc_constants.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef __MISC_CONSTANT_H_
-#define __MISC_CONSTANT_H_
-
-#include <user_constants.h>
-
-#endif
diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index 6f0d1c741bca..0b6b62733303 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -8,7 +8,6 @@
 
 #include <stdarg.h>
 #include "irq_user.h"
-#include "kern_util.h"
 #include "longjmp.h"
 #include "mm_id.h"
 #include "sysdep/tls.h"
@@ -128,33 +127,31 @@ static inline struct openflags of_cloexec(struct openflags flags)
 extern int os_stat_file(const char *file_name, struct uml_stat *buf);
 extern int os_stat_fd(const int fd, struct uml_stat *buf);
 extern int os_access(const char *file, int mode);
-extern int os_get_exec_close(int fd, int *close_on_exec);
 extern int os_set_exec_close(int fd);
 extern int os_ioctl_generic(int fd, unsigned int cmd, unsigned long arg);
 extern int os_get_ifname(int fd, char *namebuf);
 extern int os_set_slip(int fd);
-extern int os_set_owner(int fd, int pid);
 extern int os_mode_fd(int fd, int mode);
 
 extern int os_seek_file(int fd, unsigned long long offset);
-extern int os_open_file(char *file, struct openflags flags, int mode);
+extern int os_open_file(const char *file, struct openflags flags, int mode);
 extern int os_read_file(int fd, void *buf, int len);
 extern int os_write_file(int fd, const void *buf, int count);
-extern int os_file_size(char *file, unsigned long long *size_out);
-extern int os_file_modtime(char *file, unsigned long *modtime);
+extern int os_file_size(const char *file, unsigned long long *size_out);
+extern int os_file_modtime(const char *file, unsigned long *modtime);
 extern int os_pipe(int *fd, int stream, int close_on_exec);
-extern int os_set_fd_async(int fd, int owner);
+extern int os_set_fd_async(int fd);
 extern int os_clear_fd_async(int fd);
 extern int os_set_fd_block(int fd, int blocking);
 extern int os_accept_connection(int fd);
-extern int os_create_unix_socket(char *file, int len, int close_on_exec);
+extern int os_create_unix_socket(const char *file, int len, int close_on_exec);
 extern int os_shutdown_socket(int fd, int r, int w);
 extern void os_close_file(int fd);
 extern int os_rcv_fd(int fd, int *helper_pid_out);
 extern int create_unix_socket(char *file, int len, int close_on_exec);
-extern int os_connect_socket(char *name);
+extern int os_connect_socket(const char *name);
 extern int os_file_type(char *file);
-extern int os_file_mode(char *file, struct openflags *mode_out);
+extern int os_file_mode(const char *file, struct openflags *mode_out);
 extern int os_lock_file(int fd, int excl);
 extern void os_flush_stdout(void);
 extern int os_stat_filesystem(char *path, long *bsize_out,
@@ -168,14 +165,10 @@ extern int os_fchange_dir(int fd);
 
 /* start_up.c */
 extern void os_early_checks(void);
-extern int can_do_skas(void);
+extern void can_do_skas(void);
 extern void os_check_bugs(void);
 extern void check_host_supports_tls(int *supports_tls, int *tls_min);
 
-/* Make sure they are clear when running in TT mode. Required by
- * SEGV_MAYBE_FIXABLE */
-#define clear_can_do_skas() do { ptrace_faultinfo = proc_mm = 0; } while (0)
-
 /* mem.c */
 extern int create_mem_file(unsigned long long len);
 
@@ -214,7 +207,7 @@ extern int execvp_noalloc(char *buf, const char *file, char *const argv[]);
 extern int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv);
 extern int run_helper_thread(int (*proc)(void *), void *arg,
                              unsigned int flags, unsigned long *stack_out);
-extern int helper_wait(int pid, int nohang, char *pname);
+extern int helper_wait(int pid);
 
 
 /* tls.c */
@@ -237,16 +230,12 @@ extern void unblock_signals(void);
 extern int get_signals(void);
 extern int set_signals(int enable);
 
-/* trap.c */
-extern void os_fill_handlinfo(struct kern_handlers h);
-
 /* util.c */
 extern void stack_protections(unsigned long address);
 extern int raw(int fd);
 extern void setup_machinename(char *machine_out);
 extern void setup_hostinfo(char *buf, int len);
-extern int setjmp_wrapper(void (*proc)(void *, void *), ...);
-extern void os_dump_core(void);
+extern void os_dump_core(void) __attribute__ ((noreturn));
 
 /* time.c */
 extern void idle_sleep(unsigned long long nsecs);
@@ -275,11 +264,9 @@ extern int protect(struct mm_id * mm_idp, unsigned long addr,
 extern int is_skas_winch(int pid, int fd, void *data);
 extern int start_userspace(unsigned long stub_stack);
 extern int copy_context_skas0(unsigned long stack, int pid);
-extern void save_registers(int pid, struct uml_pt_regs *regs);
-extern void restore_registers(int pid, struct uml_pt_regs *regs);
 extern void userspace(struct uml_pt_regs *regs);
-extern void map_stub_pages(int fd, unsigned long code,
-                           unsigned long data, unsigned long stack);
+extern int map_stub_pages(int fd, unsigned long code, unsigned long data,
+                          unsigned long stack);
 extern void new_thread(void *stack, jmp_buf *buf, void (*handler)(void));
 extern void switch_threads(jmp_buf *me, jmp_buf *you);
 extern int start_idle_thread(void *stack, jmp_buf *switch_buf);
@@ -298,16 +285,12 @@ extern void os_free_irq_later(struct irq_fd *active_fds,
 extern int os_get_pollfd(int i);
 extern void os_set_pollfd(int i, int fd);
 extern void os_set_ioignore(void);
-extern void init_irq_signals(int on_sigstack);
 
 /* sigio.c */
 extern int add_sigio_fd(int fd);
 extern int ignore_sigio_fd(int fd);
 extern void maybe_sigio_broken(int fd, int read);
 
-/* skas/trap */
-extern void sig_handler_common_skas(int sig, void *sc_ptr);
-
 /* sys-x86_64/prctl.c */
 extern int os_arch_prctl(int pid, int code, unsigned long *addr);
 
diff --git a/arch/um/include/ptrace_user.h b/arch/um/include/ptrace_user.h
index f3450e6bc18d..4bce6e012889 100644
--- a/arch/um/include/ptrace_user.h
+++ b/arch/um/include/ptrace_user.h
@@ -1,5 +1,5 @@
 /* 
- * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
@@ -10,12 +10,6 @@
 
 extern int ptrace_getregs(long pid, unsigned long *regs_out);
 extern int ptrace_setregs(long pid, unsigned long *regs_in);
-extern int ptrace_getfpregs(long pid, unsigned long *regs_out);
-extern int ptrace_setfpregs(long pid, unsigned long *regs);
-extern void arch_enter_kernel(void *task, int pid);
-extern void arch_leave_kernel(void *task, int pid);
-extern void ptrace_pokeuser(unsigned long addr, unsigned long data);
-
 
 /* syscall emulation path in ptrace */
 
@@ -54,7 +48,8 @@ extern int sysemu_supported;
         (((int[3][3] ) { \
                 { PTRACE_SYSCALL, PTRACE_SYSCALL, PTRACE_SINGLESTEP }, \
                 { PTRACE_SYSEMU, PTRACE_SYSEMU, PTRACE_SINGLESTEP }, \
-                { PTRACE_SYSEMU, PTRACE_SYSEMU_SINGLESTEP, PTRACE_SYSEMU_SINGLESTEP }}) \
+                { PTRACE_SYSEMU, PTRACE_SYSEMU_SINGLESTEP, \
+                  PTRACE_SYSEMU_SINGLESTEP } }) \
                 [sysemu_mode][singlestep_mode])
 
 #endif
diff --git a/arch/um/include/registers.h b/arch/um/include/registers.h
index 0e27406a43a4..9ea1ae3c8f46 100644
--- a/arch/um/include/registers.h
+++ b/arch/um/include/registers.h
@@ -9,14 +9,13 @@
 #include "sysdep/ptrace.h"
 #include "sysdep/archsetjmp.h"
 
-extern void init_thread_registers(struct uml_pt_regs *to);
 extern int save_fp_registers(int pid, unsigned long *fp_regs);
 extern int restore_fp_registers(int pid, unsigned long *fp_regs);
 extern int save_fpx_registers(int pid, unsigned long *fp_regs);
 extern int restore_fpx_registers(int pid, unsigned long *fp_regs);
-extern void save_registers(int pid, struct uml_pt_regs *regs);
-extern void restore_registers(int pid, struct uml_pt_regs *regs);
-extern void init_registers(int pid);
+extern int save_registers(int pid, struct uml_pt_regs *regs);
+extern int restore_registers(int pid, struct uml_pt_regs *regs);
+extern int init_registers(int pid);
 extern void get_safe_registers(unsigned long *regs);
 extern unsigned long get_thread_reg(int reg, jmp_buf *buf);
 
diff --git a/arch/um/include/signal_kern.h b/arch/um/include/signal_kern.h
deleted file mode 100644
index aeb5d5ab1dfd..000000000000
--- a/arch/um/include/signal_kern.h
+++ /dev/null
@@ -1,22 +0,0 @@
-/* 
- * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#ifndef __SIGNAL_KERN_H__
-#define __SIGNAL_KERN_H__
-
-extern int have_signals(void *t);
-
-#endif
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/include/skas/mode-skas.h b/arch/um/include/skas/mode-skas.h
deleted file mode 100644
index e065feb000df..000000000000
--- a/arch/um/include/skas/mode-skas.h
+++ /dev/null
@@ -1,11 +0,0 @@
-/*
- * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
- * Licensed under the GPL
- */
-
-#ifndef __MODE_SKAS_H__
-#define __MODE_SKAS_H__
-
-extern void kill_off_processes_skas(void);
-
-#endif
diff --git a/arch/um/include/sysdep-i386/syscalls.h b/arch/um/include/sysdep-i386/syscalls.h
index 57bd79efbee3..905698197e35 100644
--- a/arch/um/include/sysdep-i386/syscalls.h
+++ b/arch/um/include/sysdep-i386/syscalls.h
@@ -1,5 +1,5 @@
 /* 
- * Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2000 - 2008 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
@@ -18,7 +18,8 @@ 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))
+        ((long (*)(struct syscall_args)) \
+         (*sys_call_table[syscall]))(SYSCALL_ARGS(&regs->regs))
 
 extern long sys_mmap2(unsigned long addr, unsigned long len,
                       unsigned long prot, unsigned long flags,
diff --git a/arch/um/include/sysdep-x86_64/kernel-offsets.h b/arch/um/include/sysdep-x86_64/kernel-offsets.h
index c978b589df41..a307237b7964 100644
--- a/arch/um/include/sysdep-x86_64/kernel-offsets.h
+++ b/arch/um/include/sysdep-x86_64/kernel-offsets.h
@@ -17,16 +17,7 @@
 #define OFFSET(sym, str, mem) \
         DEFINE(sym, offsetof(struct str, mem));
 
-#define __NO_STUBS 1
-#undef __SYSCALL
-#undef _ASM_X86_64_UNISTD_H_
-#define __SYSCALL(nr, sym) [nr] = 1,
-static char syscalls[] = {
-#include <asm/arch/unistd.h>
-};
-
 void foo(void)
 {
 #include <common-offsets.h>
-DEFINE(UM_NR_syscall_max, sizeof(syscalls) - 1);
 }
diff --git a/arch/um/include/sysdep-x86_64/syscalls.h b/arch/um/include/sysdep-x86_64/syscalls.h
index cf72256609e4..7cfb0b085655 100644
--- a/arch/um/include/sysdep-x86_64/syscalls.h
+++ b/arch/um/include/sysdep-x86_64/syscalls.h
@@ -30,6 +30,4 @@ extern long old_mmap(unsigned long addr, unsigned long len,
 extern syscall_handler_t sys_modify_ldt;
 extern syscall_handler_t sys_arch_prctl;
 
-#define NR_syscalls (UM_NR_syscall_max + 1)
-
 #endif
diff --git a/arch/um/include/um_mmu.h b/arch/um/include/um_mmu.h
index 8855d8df512f..82865fcf6872 100644
--- a/arch/um/include/um_mmu.h
+++ b/arch/um/include/um_mmu.h
@@ -12,10 +12,6 @@
 
 typedef struct mm_context {
         struct mm_id id;
-        unsigned long last_page_table;
-#ifdef CONFIG_3_LEVEL_PGTABLES
-        unsigned long last_pmd;
-#endif
         struct uml_ldt ldt;
 } mm_context_t;
 
diff --git a/arch/um/include/um_uaccess.h b/arch/um/include/um_uaccess.h
index fdfc06b85605..2b6fc8e0f071 100644
--- a/arch/um/include/um_uaccess.h
+++ b/arch/um/include/um_uaccess.h
@@ -6,7 +6,9 @@
 #ifndef __ARCH_UM_UACCESS_H
 #define __ARCH_UM_UACCESS_H
 
-#include "asm/fixmap.h"
+#include <asm/elf.h>
+#include <asm/fixmap.h>
+#include "sysdep/archsetjmp.h"
 
 #define __under_task_size(addr, size) \
         (((unsigned long) (addr) < TASK_SIZE) && \
diff --git a/arch/um/kernel/exec.c b/arch/um/kernel/exec.c
index 8196450451cd..76a62c0cb2bc 100644
--- a/arch/um/kernel/exec.c
+++ b/arch/um/kernel/exec.c
@@ -19,12 +19,13 @@
 void flush_thread(void)
 {
         void *data = NULL;
-        unsigned long end = proc_mm ? task_size : STUB_START;
         int ret;
 
         arch_flush_thread(&current->thread.arch);
 
-        ret = unmap(&current->mm->context.id, 0, end, 1, &data);
+        ret = unmap(&current->mm->context.id, 0, STUB_START, 0, &data);
+        ret = ret || unmap(&current->mm->context.id, STUB_END,
+                           TASK_SIZE - STUB_END, 1, &data);
         if (ret) {
                 printk(KERN_ERR "flush_thread - clearing address space failed, "
                        "err = %d\n", ret);
diff --git a/arch/um/kernel/exitcode.c b/arch/um/kernel/exitcode.c
index c716b5a6db13..984f80e668ca 100644
--- a/arch/um/kernel/exitcode.c
+++ b/arch/um/kernel/exitcode.c
@@ -1,15 +1,17 @@
 /*
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
-#include "linux/kernel.h"
-#include "linux/init.h"
-#include "linux/ctype.h"
-#include "linux/proc_fs.h"
-#include "asm/uaccess.h"
+#include <linux/ctype.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/proc_fs.h>
+#include <linux/types.h>
+#include <asm/uaccess.h>
 
-/* If read and write race, the read will still atomically read a valid
+/*
+ * If read and write race, the read will still atomically read a valid
  * value.
  */
 int uml_exitcode = 0;
@@ -19,18 +21,19 @@ static int read_proc_exitcode(char *page, char **start, off_t off,
 {
         int len, val;
 
-        /* Save uml_exitcode in a local so that we don't need to guarantee
+        /*
+         * Save uml_exitcode in a local so that we don't need to guarantee
          * that sprintf accesses it atomically.
          */
         val = uml_exitcode;
         len = sprintf(page, "%d\n", val);
         len -= off;
-        if(len <= off+count)
+        if (len <= off+count)
                 *eof = 1;
         *start = page + off;
-        if(len > count)
+        if (len > count)
                 len = count;
-        if(len < 0)
+        if (len < 0)
                 len = 0;
         return len;
 }
@@ -41,11 +44,11 @@ static int write_proc_exitcode(struct file *file, const char __user *buffer,
         char *end, buf[sizeof("nnnnn\0")];
         int tmp;
 
-        if(copy_from_user(buf, buffer, count))
+        if (copy_from_user(buf, buffer, count))
                 return -EFAULT;
 
         tmp = simple_strtol(buf, &end, 0);
-        if((*end != '\0') && !isspace(*end))
+        if ((*end != '\0') && !isspace(*end))
                 return -EINVAL;
 
         uml_exitcode = tmp;
@@ -57,7 +60,7 @@ static int make_proc_exitcode(void)
         struct proc_dir_entry *ent;
 
         ent = create_proc_entry("exitcode", 0600, &proc_root);
-        if(ent == NULL){
+        if (ent == NULL) {
                 printk(KERN_WARNING "make_proc_exitcode : Failed to register "
                        "/proc/exitcode\n");
                 return 0;
diff --git a/arch/um/kernel/gmon_syms.c b/arch/um/kernel/gmon_syms.c
index 734f873cab12..72eccd2a4113 100644
--- a/arch/um/kernel/gmon_syms.c
+++ b/arch/um/kernel/gmon_syms.c
@@ -1,5 +1,5 @@
-/* 
- * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
+/*
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
@@ -8,12 +8,13 @@
 extern void __bb_init_func(void *)  __attribute__((weak));
 EXPORT_SYMBOL(__bb_init_func);
 
-/* This is defined (and referred to in profiling stub code) only by some GCC
+/*
+ * This is defined (and referred to in profiling stub code) only by some GCC
  * versions in libgcov.
  *
  * Since SuSE backported the fix, we cannot handle it depending on GCC version.
- * So, unconditionally export it. But also give it a weak declaration, which will
- * be overridden by any other one.
+ * So, unconditionally export it. But also give it a weak declaration, which
+ * will be overridden by any other one.
  */
 
 extern void __gcov_init(void *) __attribute__((weak));
diff --git a/arch/um/kernel/gprof_syms.c b/arch/um/kernel/gprof_syms.c
index 9244f018d44c..e2f043d0de6c 100644
--- a/arch/um/kernel/gprof_syms.c
+++ b/arch/um/kernel/gprof_syms.c
@@ -1,5 +1,5 @@
 /* 
- * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
@@ -7,14 +7,3 @@
 
 extern void mcount(void);
 EXPORT_SYMBOL(mcount);
-
-/*
- * 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/initrd.c b/arch/um/kernel/initrd.c
index 16dc43e9d940..fa015565001b 100644
--- a/arch/um/kernel/initrd.c
+++ b/arch/um/kernel/initrd.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
@@ -7,7 +7,6 @@
 #include "linux/bootmem.h"
 #include "linux/initrd.h"
 #include "asm/types.h"
-#include "kern_util.h"
 #include "initrd.h"
 #include "init.h"
 #include "os.h"
@@ -21,18 +20,27 @@ static int __init read_initrd(void)
         long long size;
         int err;
 
-        if(initrd == NULL)
+        if (initrd == NULL)
                 return 0;
 
         err = os_file_size(initrd, &size);
-        if(err)
+        if (err)
                 return 0;
 
+        /*
+         * This is necessary because alloc_bootmem craps out if you
+         * ask for no memory.
+         */
+        if (size == 0) {
+                printk(KERN_ERR "\"%\" is a zero-size initrd\n");
+                return 0;
+        }
+
         area = alloc_bootmem(size);
-        if(area == NULL)
+        if (area == NULL)
                 return 0;
 
-        if(load_initrd(initrd, area, size) == -1)
+        if (load_initrd(initrd, area, size) == -1)
                 return 0;
 
         initrd_start = (unsigned long) area;
@@ -59,13 +67,15 @@ int load_initrd(char *filename, void *buf, int size)
         int fd, n;
 
         fd = os_open_file(filename, of_read(OPENFLAGS()), 0);
-        if(fd < 0){
-                printk("Opening '%s' failed - err = %d\n", filename, -fd);
+        if (fd < 0) {
+                printk(KERN_ERR "Opening '%s' failed - err = %d\n", filename,
+                       -fd);
                 return -1;
         }
         n = os_read_file(fd, buf, size);
-        if(n != size){
-                printk("Read of %d bytes from '%s' failed, err = %d\n", size,
+        if (n != size) {
+                printk(KERN_ERR "Read of %d bytes from '%s' failed, "
+                       "err = %d\n", size,
                        filename, -n);
                 return -1;
         }
diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c
index ba11ccd6a8a3..91587f8db340 100644
--- a/arch/um/kernel/irq.c
+++ b/arch/um/kernel/irq.c
@@ -107,10 +107,9 @@ int activate_fd(int irq, int fd, int type, void *dev_id)
         struct pollfd *tmp_pfd;
         struct irq_fd *new_fd, *irq_fd;
         unsigned long flags;
-        int pid, events, err, n;
+        int events, err, n;
 
-        pid = os_getpid();
-        err = os_set_fd_async(fd, pid);
+        err = os_set_fd_async(fd);
         if (err < 0)
                 goto out;
 
@@ -127,7 +126,6 @@ int activate_fd(int irq, int fd, int type, void *dev_id)
                                      .fd                = fd,
                                      .type              = type,
                                      .irq               = irq,
-                                     .pid               = pid,
                                      .events            = events,
                                      .current_events    = 0 } );
 
diff --git a/arch/um/kernel/ksyms.c b/arch/um/kernel/ksyms.c
index 7c7142ba3bd7..5311ee93ede3 100644
--- a/arch/um/kernel/ksyms.c
+++ b/arch/um/kernel/ksyms.c
@@ -18,15 +18,11 @@ EXPORT_SYMBOL(set_signals);
 EXPORT_SYMBOL(get_signals);
 EXPORT_SYMBOL(kernel_thread);
 EXPORT_SYMBOL(sys_waitpid);
-EXPORT_SYMBOL(task_size);
 EXPORT_SYMBOL(flush_tlb_range);
-EXPORT_SYMBOL(host_task_size);
 EXPORT_SYMBOL(arch_validate);
-EXPORT_SYMBOL(get_kmem_end);
 
 EXPORT_SYMBOL(high_physmem);
 EXPORT_SYMBOL(empty_zero_page);
-EXPORT_SYMBOL(um_virt_to_phys);
 EXPORT_SYMBOL(handle_page_fault);
 EXPORT_SYMBOL(find_iomem);
 
@@ -40,7 +36,6 @@ EXPORT_SYMBOL(uml_strdup);
 EXPORT_SYMBOL(os_stat_fd);
 EXPORT_SYMBOL(os_stat_file);
 EXPORT_SYMBOL(os_access);
-EXPORT_SYMBOL(os_get_exec_close);
 EXPORT_SYMBOL(os_set_exec_close);
 EXPORT_SYMBOL(os_getpid);
 EXPORT_SYMBOL(os_open_file);
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index 59822dee438a..d872fdce1d7e 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -1,49 +1,41 @@
 /*
- * Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com)
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
-#include "linux/stddef.h"
-#include "linux/kernel.h"
-#include "linux/mm.h"
-#include "linux/bootmem.h"
-#include "linux/swap.h"
-#include "linux/highmem.h"
-#include "linux/gfp.h"
-#include "asm/page.h"
-#include "asm/fixmap.h"
-#include "asm/pgalloc.h"
-#include "kern_util.h"
+#include <linux/stddef.h>
+#include <linux/bootmem.h>
+#include <linux/gfp.h>
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <asm/fixmap.h>
+#include <asm/page.h>
 #include "as-layout.h"
+#include "init.h"
 #include "kern.h"
+#include "kern_util.h"
 #include "mem_user.h"
-#include "um_uaccess.h"
 #include "os.h"
-#include "linux/types.h"
-#include "linux/string.h"
-#include "init.h"
-#include "kern_constants.h"
 
 /* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */
 unsigned long *empty_zero_page = NULL;
 /* allocated in paging_init and unchanged thereafter */
 unsigned long *empty_bad_page = NULL;
+
+/*
+ * Initialized during boot, and readonly for initializing page tables
+ * afterwards
+ */
 pgd_t swapper_pg_dir[PTRS_PER_PGD];
+
+/* Initialized at boot time, and readonly after that */
 unsigned long long highmem;
 int kmalloc_ok = 0;
 
+/* Used during early boot */
 static unsigned long brk_end;
 
-void unmap_physmem(void)
-{
-        os_unmap_memory((void *) brk_end, uml_reserved - brk_end);
-}
-
-static void map_cb(void *unused)
-{
-        map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
-}
-
 #ifdef CONFIG_HIGHMEM
 static void setup_highmem(unsigned long highmem_start,
                           unsigned long highmem_len)
@@ -53,7 +45,7 @@ static void setup_highmem(unsigned long highmem_start,
         int i;
 
         highmem_pfn = __pa(highmem_start) >> PAGE_SHIFT;
-        for(i = 0; i < highmem_len >> PAGE_SHIFT; i++){
+        for (i = 0; i < highmem_len >> PAGE_SHIFT; i++) {
                 page = &mem_map[highmem_pfn + i];
                 ClearPageReserved(page);
                 init_page_count(page);
@@ -65,14 +57,13 @@ static void setup_highmem(unsigned long highmem_start,
 void __init mem_init(void)
 {
         /* clear the zero-page */
-        memset((void *) empty_zero_page, 0, PAGE_SIZE);
+        memset(empty_zero_page, 0, PAGE_SIZE);
 
         /* Map in the area just after the brk now that kmalloc is about
          * to be turned on.
          */
         brk_end = (unsigned long) UML_ROUND_UP(sbrk(0));
-        map_cb(NULL);
-        initial_thread_cb(map_cb, NULL);
+        map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
         free_bootmem(__pa(brk_end), uml_reserved - brk_end);
         uml_reserved = brk_end;
 
@@ -85,7 +76,7 @@ void __init mem_init(void)
 #endif
         num_physpages = totalram_pages;
         max_pfn = totalram_pages;
-        printk(KERN_INFO "Memory: %luk available\n", 
+        printk(KERN_INFO "Memory: %luk available\n",
                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10));
         kmalloc_ok = 1;
 
@@ -119,7 +110,7 @@ static void __init one_md_table_init(pud_t *pud)
 #endif
 }
 
-static void __init fixrange_init(unsigned long start, unsigned long end, 
+static void __init fixrange_init(unsigned long start, unsigned long end,
                                  pgd_t *pgd_base)
 {
         pgd_t *pgd;
@@ -138,7 +129,7 @@ static void __init fixrange_init(unsigned long start, unsigned long end,
                 if (pud_none(*pud))
                         one_md_table_init(pud);
                 pmd = pmd_offset(pud, vaddr);
-                for (; (j < PTRS_PER_PMD) && (vaddr != end); pmd++, j++) {
+                for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) {
                         one_page_table_init(pmd);
                         vaddr += PMD_SIZE;
                 }
@@ -152,7 +143,7 @@ pgprot_t kmap_prot;
 
 #define kmap_get_fixmap_pte(vaddr)                                      \
         pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)),\
-                          (vaddr)), (vaddr))
+                                     (vaddr)), (vaddr))
 
 static void __init kmap_init(void)
 {
@@ -197,21 +188,23 @@ static void __init fixaddr_user_init( void)
         pud_t *pud;
         pmd_t *pmd;
         pte_t *pte;
-        unsigned long paddr, vaddr = FIXADDR_USER_START;
+        phys_t p;
+        unsigned long v, vaddr = FIXADDR_USER_START;
 
-        if (  ! size )
+        if (!size)
                 return;
 
         fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir);
-        paddr = (unsigned long)alloc_bootmem_low_pages( size);
-        memcpy( (void *)paddr, (void *)FIXADDR_USER_START, size);
-        paddr = __pa(paddr);
-        for ( ; size > 0; size-=PAGE_SIZE, vaddr+=PAGE_SIZE, paddr+=PAGE_SIZE){
+        v = (unsigned long) alloc_bootmem_low_pages(size);
+        memcpy((void *) v , (void *) FIXADDR_USER_START, size);
+        p = __pa(v);
+        for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE,
+                      p += PAGE_SIZE) {
                 pgd = swapper_pg_dir + pgd_index(vaddr);
                 pud = pud_offset(pgd, vaddr);
                 pmd = pmd_offset(pud, vaddr);
                 pte = pte_offset_kernel(pmd, vaddr);
-                pte_set_val( (*pte), paddr, PAGE_READONLY);
+                pte_set_val(*pte, p, PAGE_READONLY);
         }
 #endif
 }
@@ -223,7 +216,7 @@ void __init paging_init(void)
 
         empty_zero_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
         empty_bad_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
-        for(i = 0; i < ARRAY_SIZE(zones_size); i++)
+        for (i = 0; i < ARRAY_SIZE(zones_size); i++)
                 zones_size[i] = 0;
 
         zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) -
@@ -253,32 +246,33 @@ struct page *arch_validate(struct page *page, gfp_t mask, int order)
         int i;
 
  again:
-        if(page == NULL)
+        if (page == NULL)
                 return page;
-        if(PageHighMem(page))
+        if (PageHighMem(page))
                 return page;
 
         addr = (unsigned long) page_address(page);
-        for(i = 0; i < (1 << order); i++){
+        for (i = 0; i < (1 << order); i++) {
                 current->thread.fault_addr = (void *) addr;
-                if(__do_copy_to_user((void __user *) addr, &zero,
+                if (__do_copy_to_user((void __user *) addr, &zero,
                                      sizeof(zero),
                                      &current->thread.fault_addr,
-                                     &current->thread.fault_catcher)){
-                        if(!(mask & __GFP_WAIT))
+                                     &current->thread.fault_catcher)) {
+                        if (!(mask & __GFP_WAIT))
                                 return NULL;
                         else break;
                 }
                 addr += PAGE_SIZE;
         }
 
-        if(i == (1 << order))
+        if (i == (1 << order))
                 return page;
         page = alloc_pages(mask, order);
         goto again;
 }
 
-/* This can't do anything because nothing in the kernel image can be freed
+/*
+ * This can't do anything because nothing in the kernel image can be freed
  * since it's not in kernel physical memory.
  */
 
@@ -290,8 +284,8 @@ void free_initmem(void)
 void free_initrd_mem(unsigned long start, unsigned long end)
 {
         if (start < end)
-                printk ("Freeing initrd memory: %ldk freed\n", 
-                        (end - start) >> 10);
+                printk(KERN_INFO "Freeing initrd memory: %ldk freed\n",
+                       (end - start) >> 10);
         for (; start < end; start += PAGE_SIZE) {
                 ClearPageReserved(virt_to_page(start));
                 init_page_count(virt_to_page(start));
@@ -308,32 +302,31 @@ void show_mem(void)
         int highmem = 0;
         struct page *page;
 
-        printk("Mem-info:\n");
+        printk(KERN_INFO "Mem-info:\n");
         show_free_areas();
-        printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
+        printk(KERN_INFO "Free swap:       %6ldkB\n",
+               nr_swap_pages<<(PAGE_SHIFT-10));
         pfn = max_mapnr;
-        while(pfn-- > 0) {
+        while (pfn-- > 0) {
                 page = pfn_to_page(pfn);
                 total++;
-                if(PageHighMem(page))
+                if (PageHighMem(page))
                         highmem++;
-                if(PageReserved(page))
+                if (PageReserved(page))
                         reserved++;
-                else if(PageSwapCache(page))
+                else if (PageSwapCache(page))
                         cached++;
-                else if(page_count(page))
+                else if (page_count(page))
                         shared += page_count(page) - 1;
         }
-        printk("%d pages of RAM\n", total);
-        printk("%d pages of HIGHMEM\n", highmem);
-        printk("%d reserved pages\n", reserved);
-        printk("%d pages shared\n", shared);
-        printk("%d pages swap cached\n", cached);
+        printk(KERN_INFO "%d pages of RAM\n", total);
+        printk(KERN_INFO "%d pages of HIGHMEM\n", highmem);
+        printk(KERN_INFO "%d reserved pages\n", reserved);
+        printk(KERN_INFO "%d pages shared\n", shared);
+        printk(KERN_INFO "%d pages swap cached\n", cached);
 }
 
-/*
- * Allocate and free page tables.
- */
+/* Allocate and free page tables. */
 
 pgd_t *pgd_alloc(struct mm_struct *mm)
 {
@@ -341,14 +334,14 @@ pgd_t *pgd_alloc(struct mm_struct *mm)
 
         if (pgd) {
                 memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
-                memcpy(pgd + USER_PTRS_PER_PGD, 
-                       swapper_pg_dir + USER_PTRS_PER_PGD, 
+                memcpy(pgd + USER_PTRS_PER_PGD,
+                       swapper_pg_dir + USER_PTRS_PER_PGD,
                        (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
         }
         return pgd;
 }
 
-void pgd_free(pgd_t *pgd)
+void pgd_free(struct mm_struct *mm, pgd_t *pgd)
 {
         free_page((unsigned long) pgd);
 }
@@ -368,3 +361,15 @@ struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
         pte = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
         return pte;
 }
+
+#ifdef CONFIG_3_LEVEL_PGTABLES
+pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
+{
+        pmd_t *pmd = (pmd_t *) __get_free_page(GFP_KERNEL);
+
+        if (pmd)
+                memset(pmd, 0, PAGE_SIZE);
+
+        return pmd;
+}
+#endif
diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c
index e66432f42485..9757085a0220 100644
--- a/arch/um/kernel/physmem.c
+++ b/arch/um/kernel/physmem.c
@@ -55,16 +55,6 @@ int __init init_maps(unsigned long physmem, unsigned long iomem,
         return 0;
 }
 
-/* Changed during early boot */
-static unsigned long kmem_top = 0;
-
-unsigned long get_kmem_end(void)
-{
-        if (kmem_top == 0)
-                kmem_top = host_task_size - 1024 * 1024;
-        return kmem_top;
-}
-
 void map_memory(unsigned long virt, unsigned long phys, unsigned long len,
                 int r, int w, int x)
 {
@@ -174,10 +164,10 @@ __uml_setup("iomem=", parse_iomem,
  * setup_iomem, both of which run during early boot.  Afterwards, it's
  * unchanged.
  */
-struct iomem_region *iomem_regions = NULL;
+struct iomem_region *iomem_regions;
 
-/* Initialized in parse_iomem */
-int iomem_size = 0;
+/* Initialized in parse_iomem and unchanged thereafter */
+int iomem_size;
 
 unsigned long find_iomem(char *driver, unsigned long *len_out)
 {
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 0eae00b3e588..c07961bedb75 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -4,19 +4,21 @@
  * Licensed under the GPL
  */
 
-#include "linux/stddef.h"
-#include "linux/err.h"
-#include "linux/hardirq.h"
-#include "linux/mm.h"
-#include "linux/personality.h"
-#include "linux/proc_fs.h"
-#include "linux/ptrace.h"
-#include "linux/random.h"
-#include "linux/sched.h"
-#include "linux/tick.h"
-#include "linux/threads.h"
-#include "asm/pgtable.h"
-#include "asm/uaccess.h"
+#include <linux/stddef.h>
+#include <linux/err.h>
+#include <linux/hardirq.h>
+#include <linux/gfp.h>
+#include <linux/mm.h>
+#include <linux/personality.h>
+#include <linux/proc_fs.h>
+#include <linux/ptrace.h>
+#include <linux/random.h>
+#include <linux/sched.h>
+#include <linux/tick.h>
+#include <linux/threads.h>
+#include <asm/current.h>
+#include <asm/pgtable.h>
+#include <asm/uaccess.h>
 #include "as-layout.h"
 #include "kern_util.h"
 #include "os.h"
@@ -30,7 +32,7 @@
  */
 struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
 
-static inline int external_pid(struct task_struct *task)
+static inline int external_pid(void)
 {
         /* FIXME: Need to look up userspace_pid by cpu */
         return userspace_pid[0];
@@ -40,7 +42,7 @@ int pid_to_processor_id(int pid)
 {
         int i;
 
-        for(i = 0; i < ncpus; i++) {
+        for (i = 0; i < ncpus; i++) {
                 if (cpu_tasks[i].pid == pid)
                         return i;
         }
@@ -60,8 +62,6 @@ unsigned long alloc_stack(int order, int atomic)
         if (atomic)
                 flags = GFP_ATOMIC;
         page = __get_free_pages(flags, order);
-        if (page == 0)
-                return 0;
 
         return page;
 }
@@ -80,15 +80,15 @@ int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 static inline void set_current(struct task_struct *task)
 {
         cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
-                { external_pid(task), task });
+                { external_pid(), task });
 }
 
-extern void arch_switch_to(struct task_struct *from, struct task_struct *to);
+extern void arch_switch_to(struct task_struct *to);
 
 void *_switch_to(void *prev, void *next, void *last)
 {
         struct task_struct *from = prev;
-        struct task_struct *to= next;
+        struct task_struct *to = next;
 
         to->thread.prev_sched = from;
         set_current(to);
@@ -99,13 +99,13 @@ void *_switch_to(void *prev, void *next, void *last)
                 switch_threads(&from->thread.switch_buf,
                                &to->thread.switch_buf);
 
-                arch_switch_to(current->thread.prev_sched, current);
+                arch_switch_to(current);
 
                 if (current->thread.saved_task)
                         show_regs(&(current->thread.regs));
-                next= current->thread.saved_task;
-                prev= current;
-        } while(current->thread.saved_task);
+                to = current->thread.saved_task;
+                from = current;
+        } while (current->thread.saved_task);
 
         return current->thread.prev_sched;
 
@@ -163,8 +163,6 @@ void new_thread_handler(void)
 void fork_handler(void)
 {
         force_flush_all();
-        if (current->thread.prev_sched == NULL)
-                panic("blech");
 
         schedule_tail(current->thread.prev_sched);
 
@@ -173,7 +171,7 @@ void fork_handler(void)
          * arch_switch_to isn't needed. We could want to apply this to
          * improve performance. -bb
          */
-        arch_switch_to(current->thread.prev_sched, current);
+        arch_switch_to(current);
 
         current->thread.prev_sched = NULL;
 
@@ -204,7 +202,7 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
                 arch_copy_thread(&current->thread.arch, &p->thread.arch);
         }
         else {
-                init_thread_registers(&p->thread.regs.regs);
+                get_safe_registers(p->thread.regs.regs.gp);
                 p->thread.request.u.thread = current->thread.request.u.thread;
                 handler = new_thread_handler;
         }
@@ -237,7 +235,7 @@ void default_idle(void)
 {
         unsigned long long nsecs;
 
-        while(1) {
+        while (1) {
                 /* endless idle loop with no priority at all */
 
                 /*
@@ -256,53 +254,10 @@ void default_idle(void)
 
 void cpu_idle(void)
 {
-        cpu_tasks[current_thread->cpu].pid = os_getpid();
+        cpu_tasks[current_thread_info()->cpu].pid = os_getpid();
         default_idle();
 }
 
-void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
-                      pte_t *pte_out)
-{
-        pgd_t *pgd;
-        pud_t *pud;
-        pmd_t *pmd;
-        pte_t *pte;
-        pte_t ptent;
-
-        if (task->mm == NULL)
-                return ERR_PTR(-EINVAL);
-        pgd = pgd_offset(task->mm, addr);
-        if (!pgd_present(*pgd))
-                return ERR_PTR(-EINVAL);
-
-        pud = pud_offset(pgd, addr);
-        if (!pud_present(*pud))
-                return ERR_PTR(-EINVAL);
-
-        pmd = pmd_offset(pud, addr);
-        if (!pmd_present(*pmd))
-                return ERR_PTR(-EINVAL);
-
-        pte = pte_offset_kernel(pmd, addr);
-        ptent = *pte;
-        if (!pte_present(ptent))
-                return ERR_PTR(-EINVAL);
-
-        if (pte_out != NULL)
-                *pte_out = ptent;
-        return (void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK);
-}
-
-char *current_cmd(void)
-{
-#if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
-        return "(Unknown)";
-#else
-        void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
-        return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
-#endif
-}
-
 void dump_thread(struct pt_regs *regs, struct user *u)
 {
 }
@@ -317,7 +272,7 @@ int user_context(unsigned long sp)
         unsigned long stack;
 
         stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
-        return stack != (unsigned long) current_thread;
+        return stack != (unsigned long) current_thread_info();
 }
 
 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
@@ -331,7 +286,7 @@ void do_uml_exitcalls(void)
                 (*call)();
 }
 
-char *uml_strdup(char *string)
+char *uml_strdup(const char *string)
 {
         return kstrdup(string, GFP_KERNEL);
 }
@@ -359,7 +314,7 @@ int strlen_user_proc(char __user *str)
 int smp_sigio_handler(void)
 {
 #ifdef CONFIG_SMP
-        int cpu = current_thread->cpu;
+        int cpu = current_thread_info()->cpu;
         IPI_handler(cpu);
         if (cpu != 0)
                 return 1;
@@ -369,7 +324,7 @@ int smp_sigio_handler(void)
 
 int cpu(void)
 {
-        return current_thread->cpu;
+        return current_thread_info()->cpu;
 }
 
 static atomic_t using_sysemu = ATOMIC_INIT(0);
@@ -435,7 +390,7 @@ int singlestepping(void * t)
 {
         struct task_struct *task = t ? t : current;
 
-        if ( ! (task->ptrace & PT_DTRACE) )
+        if (!(task->ptrace & PT_DTRACE))
                 return 0;
 
         if (task->thread.singlestep_syscall)
@@ -459,3 +414,46 @@ unsigned long arch_align_stack(unsigned long sp)
         return sp & ~0xf;
 }
 #endif
+
+unsigned long get_wchan(struct task_struct *p)
+{
+        unsigned long stack_page, sp, ip;
+        bool seen_sched = 0;
+
+        if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING))
+                return 0;
+
+        stack_page = (unsigned long) task_stack_page(p);
+        /* Bail if the process has no kernel stack for some reason */
+        if (stack_page == 0)
+                return 0;
+
+        sp = p->thread.switch_buf->JB_SP;
+        /*
+         * Bail if the stack pointer is below the bottom of the kernel
+         * stack for some reason
+         */
+        if (sp < stack_page)
+                return 0;
+
+        while (sp < stack_page + THREAD_SIZE) {
+                ip = *((unsigned long *) sp);
+                if (in_sched_functions(ip))
+                        /* Ignore everything until we're above the scheduler */
+                        seen_sched = 1;
+                else if (kernel_text_address(ip) && seen_sched)
+                        return ip;
+
+                sp += sizeof(unsigned long);
+        }
+
+        return 0;
+}
+
+int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu)
+{
+        int cpu = current_thread_info()->cpu;
+
+        return save_fp_registers(userspace_pid[cpu], (unsigned long *) fpu);
+}
+
diff --git a/arch/um/kernel/reboot.c b/arch/um/kernel/reboot.c
index 04cebcf0679f..00197d3d21ec 100644
--- a/arch/um/kernel/reboot.c
+++ b/arch/um/kernel/reboot.c
@@ -4,6 +4,7 @@
  */
 
 #include "linux/sched.h"
+#include "kern_util.h"
 #include "os.h"
 #include "skas.h"
 
@@ -11,7 +12,7 @@ void (*pm_power_off)(void);
 
 static void kill_off_processes(void)
 {
-        if(proc_mm)
+        if (proc_mm)
                 /*
                  * FIXME: need to loop over userspace_pids
                  */
@@ -21,8 +22,8 @@ static void kill_off_processes(void)
                 int pid, me;
 
                 me = os_getpid();
-                for_each_process(p){
-                        if(p->mm == NULL)
+                for_each_process(p) {
+                        if (p->mm == NULL)
                                 continue;
 
                         pid = p->mm->context.id.u.pid;
diff --git a/arch/um/kernel/sigio.c b/arch/um/kernel/sigio.c
index 89f9866a1354..2b272b63b514 100644
--- a/arch/um/kernel/sigio.c
+++ b/arch/um/kernel/sigio.c
@@ -1,18 +1,12 @@
 /*
- * Copyright (C) 2002 - 2003 Jeff Dike (jdike@addtoit.com)
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
  * Licensed under the GPL
  */
 
-#include "linux/kernel.h"
-#include "linux/list.h"
-#include "linux/slab.h"
-#include "linux/signal.h"
-#include "linux/interrupt.h"
-#include "init.h"
-#include "sigio.h"
-#include "irq_user.h"
+#include <linux/interrupt.h>
 #include "irq_kern.h"
 #include "os.h"
+#include "sigio.h"
 
 /* Protected by sigio_lock() called from write_sigio_workaround */
 static int sigio_irq_fd = -1;
@@ -33,9 +27,9 @@ int write_sigio_irq(int fd)
         err = um_request_irq(SIGIO_WRITE_IRQ, fd, IRQ_READ, sigio_interrupt,
                              IRQF_DISABLED|IRQF_SAMPLE_RANDOM, "write sigio",
                              NULL);
-        if(err){
-                printk("write_sigio_irq : um_request_irq failed, err = %d\n",
-                       err);
+        if (err) {
+                printk(KERN_ERR "write_sigio_irq : um_request_irq failed, "
+                       "err = %d\n", err);
                 return -1;
         }
         sigio_irq_fd = fd;
diff --git a/arch/um/kernel/signal.c b/arch/um/kernel/signal.c
index 19cb97733937..b0fce720c4d0 100644
--- a/arch/um/kernel/signal.c
+++ b/arch/um/kernel/signal.c
@@ -3,12 +3,12 @@
  * Licensed under the GPL
  */
 
-#include "linux/module.h"
-#include "linux/ptrace.h"
-#include "linux/sched.h"
-#include "asm/siginfo.h"
-#include "asm/signal.h"
-#include "asm/unistd.h"
+#include <linux/module.h>
+#include <linux/ptrace.h>
+#include <linux/sched.h>
+#include <asm/siginfo.h>
+#include <asm/signal.h>
+#include <asm/unistd.h>
 #include "frame_kern.h"
 #include "kern_util.h"
 #include "sigcontext.h"
@@ -36,7 +36,7 @@ static int handle_signal(struct pt_regs *regs, unsigned long signr,
         /* Did we come from a system call? */
         if (PT_REGS_SYSCALL_NR(regs) >= 0) {
                 /* If so, check system call restarting.. */
-                switch(PT_REGS_SYSCALL_RET(regs)) {
+                switch (PT_REGS_SYSCALL_RET(regs)) {
                 case -ERESTART_RESTARTBLOCK:
                 case -ERESTARTNOHAND:
                         PT_REGS_SYSCALL_RET(regs) = -EINTR;
@@ -116,7 +116,7 @@ static int kern_do_signal(struct pt_regs *regs)
         /* Did we come from a system call? */
         if (!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)) {
                 /* Restart the system call - no handlers present */
-                switch(PT_REGS_SYSCALL_RET(regs)) {
+                switch (PT_REGS_SYSCALL_RET(regs)) {
                 case -ERESTARTNOHAND:
                 case -ERESTARTSYS:
                 case -ERESTARTNOINTR:
diff --git a/arch/um/kernel/skas/clone.c b/arch/um/kernel/skas/clone.c
index 8d07a7acb909..2c8583c1a344 100644
--- a/arch/um/kernel/skas/clone.c
+++ b/arch/um/kernel/skas/clone.c
@@ -1,17 +1,20 @@
-#include <sched.h>
+/*
+ * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
 #include <signal.h>
-#include <sys/mman.h>
-#include <sys/time.h>
+#include <sched.h>
 #include <asm/unistd.h>
+#include <sys/time.h>
 #include "as-layout.h"
+#include "kern_constants.h"
 #include "ptrace_user.h"
-#include "skas.h"
 #include "stub-data.h"
-#include "uml-config.h"
 #include "sysdep/stub.h"
-#include "kern_constants.h"
 
-/* This is in a separate file because it needs to be compiled with any
+/*
+ * This is in a separate file because it needs to be compiled with any
  * extraneous gcc flags (-pg, -fprofile-arcs, -ftest-coverage) disabled
  *
  * Use UM_KERN_PAGE_SIZE instead of PAGE_SIZE because that calls getpagesize
@@ -26,25 +29,26 @@ stub_clone_handler(void)
 
         err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD,
                             STUB_DATA + UM_KERN_PAGE_SIZE / 2 - sizeof(void *));
-        if(err != 0)
+        if (err != 0)
                 goto out;
 
         err = stub_syscall4(__NR_ptrace, PTRACE_TRACEME, 0, 0, 0);
-        if(err)
+        if (err)
                 goto out;
 
-        err = stub_syscall3(__NR_setitimer, ITIMER_VIRTUAL, 
+        err = stub_syscall3(__NR_setitimer, ITIMER_VIRTUAL,
                             (long) &data->timer, 0);
-        if(err)
+        if (err)
                 goto out;
 
         remap_stack(data->fd, data->offset);
         goto done;
 
  out:
-        /* save current result. 
-         * Parent: pid; 
-         * child: retcode of mmap already saved and it jumps around this 
+        /*
+         * save current result.
+         * Parent: pid;
+         * child: retcode of mmap already saved and it jumps around this
          * assignment
          */
         data->err = err;
diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c
index f859ec306cd5..78b3e9f69d57 100644
--- a/arch/um/kernel/skas/mmu.c
+++ b/arch/um/kernel/skas/mmu.c
@@ -34,33 +34,14 @@ static int init_stub_pte(struct mm_struct *mm, unsigned long proc,
         if (!pte)
                 goto out_pte;
 
-        /*
-         * There's an interaction between the skas0 stub pages, stack
-         * randomization, and the BUG at the end of exit_mmap.  exit_mmap
-         * checks that the number of page tables freed is the same as had
-         * been allocated.  If the stack is on the last page table page,
-         * then the stack pte page will be freed, and if not, it won't.  To
-         * avoid having to know where the stack is, or if the process mapped
-         * something at the top of its address space for some other reason,
-         * we set TASK_SIZE to end at the start of the last page table.
-         * This keeps exit_mmap off the last page, but introduces a leak
-         * of that page.  So, we hang onto it here and free it in
-         * destroy_context_skas.
-         */
-
-        mm->context.last_page_table = pmd_page_vaddr(*pmd);
-#ifdef CONFIG_3_LEVEL_PGTABLES
-        mm->context.last_pmd = (unsigned long) __va(pud_val(*pud));
-#endif
-
         *pte = mk_pte(virt_to_page(kernel), __pgprot(_PAGE_PRESENT));
         *pte = pte_mkread(*pte);
         return 0;
 
  out_pmd:
-        pud_free(pud);
+        pud_free(mm, pud);
  out_pte:
-        pmd_free(pmd);
+        pmd_free(mm, pmd);
  out:
         return -ENOMEM;
 }
@@ -76,24 +57,6 @@ int init_new_context(struct task_struct *task, struct mm_struct *mm)
                 stack = get_zeroed_page(GFP_KERNEL);
                 if (stack == 0)
                         goto out;
-
-                /*
-                 * 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.
-                 */
-                mm->pgd[USER_PTRS_PER_PGD] = __pgd(0);
-
-                ret = init_stub_pte(mm, STUB_CODE,
-                                    (unsigned long) &__syscall_stub_start);
-                if (ret)
-                        goto out_free;
-
-                ret = init_stub_pte(mm, STUB_DATA, stack);
-                if (ret)
-                        goto out_free;
-
-                mm->nr_ptes--;
         }
 
         to_mm->id.stack = stack;
@@ -114,6 +77,11 @@ int init_new_context(struct task_struct *task, struct mm_struct *mm)
                         to_mm->id.u.pid = copy_context_skas0(stack,
                                                              from_mm->id.u.pid);
                 else to_mm->id.u.pid = start_userspace(stack);
+
+                if (to_mm->id.u.pid < 0) {
+                        ret = to_mm->id.u.pid;
+                        goto out_free;
+                }
         }
 
         ret = init_new_ldt(to_mm, from_mm);
@@ -132,24 +100,87 @@ int init_new_context(struct task_struct *task, struct mm_struct *mm)
         return ret;
 }
 
+void arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
+{
+        struct page **pages;
+        int err, ret;
+
+        if (!skas_needs_stub)
+                return;
+
+        ret = init_stub_pte(mm, STUB_CODE,
+                            (unsigned long) &__syscall_stub_start);
+        if (ret)
+                goto out;
+
+        ret = init_stub_pte(mm, STUB_DATA, mm->context.id.stack);
+        if (ret)
+                goto out;
+
+        pages = kmalloc(2 * sizeof(struct page *), GFP_KERNEL);
+        if (pages == NULL) {
+                printk(KERN_ERR "arch_dup_mmap failed to allocate 2 page "
+                       "pointers\n");
+                goto out;
+        }
+
+        pages[0] = virt_to_page(&__syscall_stub_start);
+        pages[1] = virt_to_page(mm->context.id.stack);
+
+        /* dup_mmap already holds mmap_sem */
+        err = install_special_mapping(mm, STUB_START, STUB_END - STUB_START,
+                                      VM_READ | VM_MAYREAD | VM_EXEC |
+                                      VM_MAYEXEC | VM_DONTCOPY, pages);
+        if (err) {
+                printk(KERN_ERR "install_special_mapping returned %d\n", err);
+                goto out_free;
+        }
+        return;
+
+out_free:
+        kfree(pages);
+out:
+        force_sigsegv(SIGSEGV, current);
+}
+
+void arch_exit_mmap(struct mm_struct *mm)
+{
+        pte_t *pte;
+
+        pte = virt_to_pte(mm, STUB_CODE);
+        if (pte != NULL)
+                pte_clear(mm, STUB_CODE, pte);
+
+        pte = virt_to_pte(mm, STUB_DATA);
+        if (pte == NULL)
+                return;
+
+        pte_clear(mm, STUB_DATA, pte);
+}
+
 void destroy_context(struct mm_struct *mm)
 {
         struct mm_context *mmu = &mm->context;
 
         if (proc_mm)
                 os_close_file(mmu->id.u.mm_fd);
-        else
+        else {
+                /*
+                 * If init_new_context wasn't called, this will be
+                 * zero, resulting in a kill(0), which will result in the
+                 * whole UML suddenly dying.  Also, cover negative and
+                 * 1 cases, since they shouldn't happen either.
+                 */
+                if (mmu->id.u.pid < 2) {
+                        printk(KERN_ERR "corrupt mm_context - pid = %d\n",
+                               mmu->id.u.pid);
+                        return;
+                }
                 os_kill_ptraced_process(mmu->id.u.pid, 1);
+        }
 
-        if (!proc_mm || !ptrace_faultinfo) {
+        if (skas_needs_stub)
                 free_page(mmu->id.stack);
-                pte_lock_deinit(virt_to_page(mmu->last_page_table));
-                pte_free_kernel((pte_t *) mmu->last_page_table);
-                dec_zone_page_state(virt_to_page(mmu->last_page_table), NR_PAGETABLE);
-#ifdef CONFIG_3_LEVEL_PGTABLES
-                pmd_free((pmd_t *) mmu->last_pmd);
-#endif
-        }
 
         free_ldt(mmu);
 }
diff --git a/arch/um/kernel/skas/process.c b/arch/um/kernel/skas/process.c
index fce389c2342f..2e9852c0d487 100644
--- a/arch/um/kernel/skas/process.c
+++ b/arch/um/kernel/skas/process.c
@@ -6,19 +6,25 @@
 #include "linux/init.h"
 #include "linux/sched.h"
 #include "as-layout.h"
+#include "kern.h"
 #include "os.h"
 #include "skas.h"
 
 int new_mm(unsigned long stack)
 {
-        int fd;
+        int fd, err;
 
         fd = os_open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0);
         if (fd < 0)
                 return fd;
 
-        if (skas_needs_stub)
-                map_stub_pages(fd, STUB_CODE, STUB_DATA, stack);
+        if (skas_needs_stub) {
+                err = map_stub_pages(fd, STUB_CODE, STUB_DATA, stack);
+                if (err) {
+                        os_close_file(fd);
+                        return err;
+                }
+        }
 
         return fd;
 }
@@ -49,8 +55,14 @@ int __init start_uml(void)
 {
         stack_protections((unsigned long) &cpu0_irqstack);
         set_sigstack(cpu0_irqstack, THREAD_SIZE);
-        if (proc_mm)
+        if (proc_mm) {
                 userspace_pid[0] = start_userspace(0);
+                if (userspace_pid[0] < 0) {
+                        printf("start_uml - start_userspace returned %d\n",
+                               userspace_pid[0]);
+                        exit(1);
+                }
+        }
 
         init_new_thread_signals();
 
diff --git a/arch/um/kernel/skas/syscall.c b/arch/um/kernel/skas/syscall.c
index 50b476f2b38d..4e3b820bd2be 100644
--- a/arch/um/kernel/skas/syscall.c
+++ b/arch/um/kernel/skas/syscall.c
@@ -9,6 +9,9 @@
 #include "sysdep/ptrace.h"
 #include "sysdep/syscalls.h"
 
+extern int syscall_table_size;
+#define NR_syscalls (syscall_table_size / sizeof(void *))
+
 void handle_syscall(struct uml_pt_regs *r)
 {
         struct pt_regs *regs = container_of(r, struct pt_regs, regs);
@@ -17,9 +20,6 @@ void handle_syscall(struct uml_pt_regs *r)
 
         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
diff --git a/arch/um/kernel/skas/uaccess.c b/arch/um/kernel/skas/uaccess.c
index 1d8b119f2d0e..e22c96993db3 100644
--- a/arch/um/kernel/skas/uaccess.c
+++ b/arch/um/kernel/skas/uaccess.c
@@ -3,128 +3,130 @@
  * Licensed under the GPL
  */
 
-#include "linux/err.h"
-#include "linux/highmem.h"
-#include "linux/mm.h"
-#include "asm/current.h"
-#include "asm/page.h"
-#include "asm/pgtable.h"
+#include <linux/err.h>
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <asm/current.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
 #include "kern_util.h"
 #include "os.h"
 
-extern void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
-                             pte_t *pte_out);
-
-static unsigned long maybe_map(unsigned long virt, int is_write)
+pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr)
 {
-        pte_t pte;
-        int err;
+        pgd_t *pgd;
+        pud_t *pud;
+        pmd_t *pmd;
+
+        if (mm == NULL)
+                return NULL;
+
+        pgd = pgd_offset(mm, addr);
+        if (!pgd_present(*pgd))
+                return NULL;
+
+        pud = pud_offset(pgd, addr);
+        if (!pud_present(*pud))
+                return NULL;
 
-        void *phys = um_virt_to_phys(current, virt, &pte);
-        int dummy_code;
+        pmd = pmd_offset(pud, addr);
+        if (!pmd_present(*pmd))
+                return NULL;
+
+        return pte_offset_kernel(pmd, addr);
+}
+
+static pte_t *maybe_map(unsigned long virt, int is_write)
+{
+        pte_t *pte = virt_to_pte(current->mm, virt);
+        int err, dummy_code;
 
-        if (IS_ERR(phys) || (is_write && !pte_write(pte))) {
+        if ((pte == NULL) || !pte_present(*pte) ||
+            (is_write && !pte_write(*pte))) {
                 err = handle_page_fault(virt, 0, is_write, 1, &dummy_code);
                 if (err)
-                        return -1UL;
-                phys = um_virt_to_phys(current, virt, NULL);
+                        return NULL;
+                pte = virt_to_pte(current->mm, virt);
         }
-        if (IS_ERR(phys))
-                phys = (void *) -1;
+        if (!pte_present(*pte))
+                pte = NULL;
 
-        return (unsigned long) phys;
+        return pte;
 }
 
 static int do_op_one_page(unsigned long addr, int len, int is_write,
                  int (*op)(unsigned long addr, int len, void *arg), void *arg)
 {
+        jmp_buf buf;
         struct page *page;
-        int n;
+        pte_t *pte;
+        int n, faulted;
 
-        addr = maybe_map(addr, is_write);
-        if (addr == -1UL)
+        pte = maybe_map(addr, is_write);
+        if (pte == NULL)
                 return -1;
 
-        page = phys_to_page(addr);
+        page = pte_page(*pte);
         addr = (unsigned long) kmap_atomic(page, KM_UML_USERCOPY) +
                 (addr & ~PAGE_MASK);
 
-        n = (*op)(addr, len, arg);
+        current->thread.fault_catcher = &buf;
+
+        faulted = UML_SETJMP(&buf);
+        if (faulted == 0)
+                n = (*op)(addr, len, arg);
+        else
+                n = -1;
+
+        current->thread.fault_catcher = NULL;
 
         kunmap_atomic(page, KM_UML_USERCOPY);
 
         return n;
 }
 
-static void do_buffer_op(void *jmpbuf, void *arg_ptr)
+static int buffer_op(unsigned long addr, int len, int is_write,
+                     int (*op)(unsigned long, int, void *), void *arg)
 {
-        va_list args;
-        unsigned long addr;
-        int len, is_write, size, remain, n;
-        int (*op)(unsigned long, int, void *);
-        void *arg;
-        int *res;
-
-        va_copy(args, *(va_list *)arg_ptr);
-        addr = va_arg(args, unsigned long);
-        len = va_arg(args, int);
-        is_write = va_arg(args, int);
-        op = va_arg(args, void *);
-        arg = va_arg(args, void *);
-        res = va_arg(args, int *);
-        va_end(args);
+        int size, remain, n;
+
         size = min(PAGE_ALIGN(addr) - addr, (unsigned long) len);
         remain = len;
 
-        current->thread.fault_catcher = jmpbuf;
         n = do_op_one_page(addr, size, is_write, op, arg);
         if (n != 0) {
-                *res = (n < 0 ? remain : 0);
+                remain = (n < 0 ? remain : 0);
                 goto out;
         }
 
         addr += size;
         remain -= size;
-        if (remain == 0) {
-                *res = 0;
+        if (remain == 0)
                 goto out;
-        }
 
-        while(addr < ((addr + remain) & PAGE_MASK)) {
+        while (addr < ((addr + remain) & PAGE_MASK)) {
                 n = do_op_one_page(addr, PAGE_SIZE, is_write, op, arg);
                 if (n != 0) {
-                        *res = (n < 0 ? remain : 0);
+                        remain = (n < 0 ? remain : 0);
                         goto out;
                 }
 
                 addr += PAGE_SIZE;
                 remain -= PAGE_SIZE;
         }
-        if (remain == 0) {
-                *res = 0;
+        if (remain == 0)
                 goto out;
-        }
 
         n = do_op_one_page(addr, remain, is_write, op, arg);
-        if (n != 0)
-                *res = (n < 0 ? remain : 0);
-        else *res = 0;
- out:
-        current->thread.fault_catcher = NULL;
-}
-
-static int buffer_op(unsigned long addr, int len, int is_write,
-                     int (*op)(unsigned long addr, int len, void *arg),
-                     void *arg)
-{
-        int faulted, res;
-
-        faulted = setjmp_wrapper(do_buffer_op, addr, len, is_write, op, arg,
-                                 &res);
-        if (!faulted)
-                return res;
+        if (n != 0) {
+                remain = (n < 0 ? remain : 0);
+                goto out;
+        }
 
-        return addr + len - (unsigned long) current->thread.fault_addr;
+        return 0;
+ out:
+        return remain;
 }
 
 static int copy_chunk_from_user(unsigned long from, int len, void *arg)
diff --git a/arch/um/kernel/smp.c b/arch/um/kernel/smp.c
index 36d89cf8d20b..e1062ec36d40 100644
--- a/arch/um/kernel/smp.c
+++ b/arch/um/kernel/smp.c
@@ -21,7 +21,6 @@ DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
 #include "asm/smp.h"
 #include "asm/processor.h"
 #include "asm/spinlock.h"
-#include "kern_util.h"
 #include "kern.h"
 #include "irq_user.h"
 #include "os.h"
@@ -61,7 +60,7 @@ void smp_send_stop(void)
                         continue;
                 os_write_file(cpu_data[i].ipi_pipe[1], "S", 1);
         }
-        printk(KERN_INFO "done\n");
+        printk(KERN_CONT "done\n");
 }
 
 static cpumask_t smp_commenced_mask = CPU_MASK_NONE;
@@ -75,8 +74,7 @@ static int idle_proc(void *cpup)
         if (err < 0)
                 panic("CPU#%d failed to create IPI pipe, err = %d", cpu, -err);
 
-        os_set_fd_async(cpu_data[cpu].ipi_pipe[0],
-                     current->thread.mode.tt.extern_pid);
+        os_set_fd_async(cpu_data[cpu].ipi_pipe[0]);
 
         wmb();
         if (cpu_test_and_set(cpu, cpu_callin_map)) {
@@ -129,8 +127,7 @@ void smp_prepare_cpus(unsigned int maxcpus)
         if (err < 0)
                 panic("CPU#0 failed to create IPI pipe, errno = %d", -err);
 
-        os_set_fd_async(cpu_data[me].ipi_pipe[0],
-                     current->thread.mode.tt.extern_pid);
+        os_set_fd_async(cpu_data[me].ipi_pipe[0]);
 
         for (cpu = 1; cpu < ncpus; cpu++) {
                 printk(KERN_INFO "Booting processor %d...\n", cpu);
@@ -143,9 +140,8 @@ void smp_prepare_cpus(unsigned int maxcpus)
                 while (waittime-- && !cpu_isset(cpu, cpu_callin_map))
                         cpu_relax();
 
-                if (cpu_isset(cpu, cpu_callin_map))
-                        printk(KERN_INFO "done\n");
-                else printk(KERN_INFO "failed\n");
+                printk(KERN_INFO "%s\n",
+                       cpu_isset(cpu, cpu_calling_map) ? "done" : "failed");
         }
 }
 
diff --git a/arch/um/kernel/syscall.c b/arch/um/kernel/syscall.c
index b9d92b2089ae..9cffc628a37e 100644
--- a/arch/um/kernel/syscall.c
+++ b/arch/um/kernel/syscall.c
@@ -13,9 +13,6 @@
 #include "asm/uaccess.h"
 #include "asm/unistd.h"
 
-/*  Unlocked, I don't care if this is a bit off */
-int nsyscalls = 0;
-
 long sys_fork(void)
 {
         long ret;
diff --git a/arch/um/kernel/sysrq.c b/arch/um/kernel/sysrq.c
index 93263571d813..56d43d0a3960 100644
--- a/arch/um/kernel/sysrq.c
+++ b/arch/um/kernel/sysrq.c
@@ -1,38 +1,37 @@
-/* 
- * Copyright (C) 2001 Jeff Dike (jdike@karaya.com)
+/*
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
-#include "linux/sched.h"
-#include "linux/kernel.h"
-#include "linux/module.h"
-#include "linux/kallsyms.h"
-#include "asm/page.h"
-#include "asm/processor.h"
+#include <linux/kallsyms.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
 #include "sysrq.h"
 
 /* Catch non-i386 SUBARCH's. */
 #if !defined(CONFIG_UML_X86) || defined(CONFIG_64BIT)
 void show_trace(struct task_struct *task, unsigned long * stack)
 {
-        unsigned long addr;
+        unsigned long addr;
 
-        if (!stack) {
+        if (!stack) {
                 stack = (unsigned long*) &stack;
                 WARN_ON(1);
         }
 
-        printk("Call Trace: \n");
-        while (((long) stack & (THREAD_SIZE-1)) != 0) {
-                addr = *stack;
+        printk(KERN_INFO "Call Trace: \n");
+        while (((long) stack & (THREAD_SIZE-1)) != 0) {
+                addr = *stack;
                 if (__kernel_text_address(addr)) {
-                        printk("%08lx:  [<%08lx>]", (unsigned long) stack, addr);
-                        print_symbol(" %s", addr);
-                        printk("\n");
-                }
-                stack++;
-        }
-        printk("\n");
+                        printk(KERN_INFO "%08lx:  [<%08lx>]",
+                               (unsigned long) stack, addr);
+                        print_symbol(KERN_CONT " %s", addr);
+                        printk(KERN_CONT "\n");
+                }
+                stack++;
+        }
+        printk(KERN_INFO "\n");
 }
 #endif
 
@@ -67,14 +66,13 @@ void show_stack(struct task_struct *task, unsigned long *esp)
         }
 
         stack = esp;
-        for(i = 0; i < kstack_depth_to_print; i++) {
+        for (i = 0; i < kstack_depth_to_print; i++) {
                 if (kstack_end(stack))
                         break;
                 if (i && ((i % 8) == 0))
-                        printk("\n       ");
+                        printk("\n" KERN_INFO "       ");
                 printk("%08lx ", *stack++);
         }
 
-        printk("Call Trace: \n");
         show_trace(task, esp);
 }
diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c
index 1ac746a9eae1..e066e84493b1 100644
--- a/arch/um/kernel/time.c
+++ b/arch/um/kernel/time.c
@@ -3,12 +3,12 @@
  * Licensed under the GPL
  */
 
-#include "linux/clockchips.h"
-#include "linux/interrupt.h"
-#include "linux/jiffies.h"
-#include "linux/threads.h"
-#include "asm/irq.h"
-#include "asm/param.h"
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/jiffies.h>
+#include <linux/threads.h>
+#include <asm/irq.h>
+#include <asm/param.h>
 #include "kern_util.h"
 #include "os.h"
 
@@ -32,7 +32,7 @@ void timer_handler(int sig, struct uml_pt_regs *regs)
 static void itimer_set_mode(enum clock_event_mode mode,
                             struct clock_event_device *evt)
 {
-        switch(mode) {
+        switch (mode) {
         case CLOCK_EVT_MODE_PERIODIC:
                 set_interval();
                 break;
diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c
index f4a0e407eee4..d175d0566af0 100644
--- a/arch/um/kernel/tlb.c
+++ b/arch/um/kernel/tlb.c
@@ -3,9 +3,10 @@
  * Licensed under the GPL
  */
 
-#include "linux/mm.h"
-#include "asm/pgtable.h"
-#include "asm/tlbflush.h"
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <asm/pgtable.h>
+#include <asm/tlbflush.h>
 #include "as-layout.h"
 #include "mem_user.h"
 #include "os.h"
@@ -56,7 +57,7 @@ static int do_ops(struct host_vm_change *hvc, int end,
 
         for (i = 0; i < end && !ret; i++) {
                 op = &hvc->ops[i];
-                switch(op->type) {
+                switch (op->type) {
                 case MMAP:
                         ret = map(hvc->id, op->u.mmap.addr, op->u.mmap.len,
                                   op->u.mmap.prot, op->u.mmap.fd,
@@ -183,27 +184,30 @@ static inline int update_pte_range(pmd_t *pmd, unsigned long addr,
 
         pte = pte_offset_kernel(pmd, addr);
         do {
+                if ((addr >= STUB_START) && (addr < STUB_END))
+                        continue;
+
                 r = pte_read(*pte);
                 w = pte_write(*pte);
                 x = pte_exec(*pte);
                 if (!pte_young(*pte)) {
                         r = 0;
                         w = 0;
-                } else if (!pte_dirty(*pte)) {
+                } else if (!pte_dirty(*pte))
                         w = 0;
-                }
+
                 prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
                         (x ? UM_PROT_EXEC : 0));
                 if (hvc->force || pte_newpage(*pte)) {
                         if (pte_present(*pte))
                                 ret = add_mmap(addr, pte_val(*pte) & PAGE_MASK,
                                                PAGE_SIZE, prot, hvc);
-                        else ret = add_munmap(addr, PAGE_SIZE, hvc);
-                }
-                else if (pte_newprot(*pte))
+                        else
+                                ret = add_munmap(addr, PAGE_SIZE, hvc);
+                } else if (pte_newprot(*pte))
                         ret = add_mprotect(addr, PAGE_SIZE, prot, hvc);
                 *pte = pte_mkuptodate(*pte);
-        } while (pte++, addr += PAGE_SIZE, ((addr != end) && !ret));
+        } while (pte++, addr += PAGE_SIZE, ((addr < end) && !ret));
         return ret;
 }
 
@@ -225,7 +229,7 @@ static inline int update_pmd_range(pud_t *pud, unsigned long addr,
                         }
                 }
                 else ret = update_pte_range(pmd, addr, next, hvc);
-        } while (pmd++, addr = next, ((addr != end) && !ret));
+        } while (pmd++, addr = next, ((addr < end) && !ret));
         return ret;
 }
 
@@ -247,7 +251,7 @@ static inline int update_pud_range(pgd_t *pgd, unsigned long addr,
                         }
                 }
                 else ret = update_pmd_range(pud, addr, next, hvc);
-        } while (pud++, addr = next, ((addr != end) && !ret));
+        } while (pud++, addr = next, ((addr < end) && !ret));
         return ret;
 }
 
@@ -270,7 +274,7 @@ void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
                         }
                 }
                 else ret = update_pud_range(pgd, addr, next, &hvc);
-        } while (pgd++, addr = next, ((addr != end_addr) && !ret));
+        } while (pgd++, addr = next, ((addr < end_addr) && !ret));
 
         if (!ret)
                 ret = do_ops(&hvc, hvc.index, 1);
@@ -485,9 +489,6 @@ void __flush_tlb_one(unsigned long addr)
 static void fix_range(struct mm_struct *mm, unsigned long start_addr,
                       unsigned long end_addr, int force)
 {
-        if (!proc_mm && (end_addr > STUB_START))
-                end_addr = STUB_START;
-
         fix_range_common(mm, start_addr, end_addr, force);
 }
 
@@ -499,10 +500,9 @@ void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
         else fix_range(vma->vm_mm, start, end, 0);
 }
 
-void flush_tlb_mm(struct mm_struct *mm)
+void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
+                        unsigned long end)
 {
-        unsigned long end;
-
         /*
          * Don't bother flushing if this address space is about to be
          * destroyed.
@@ -510,8 +510,17 @@ void flush_tlb_mm(struct mm_struct *mm)
         if (atomic_read(&mm->mm_users) == 0)
                 return;
 
-        end = proc_mm ? task_size : STUB_START;
-        fix_range(mm, 0, end, 0);
+        fix_range(mm, start, end, 0);
+}
+
+void flush_tlb_mm(struct mm_struct *mm)
+{
+        struct vm_area_struct *vma = mm->mmap;
+
+        while (vma != NULL) {
+                fix_range(mm, vma->vm_start, vma->vm_end, 0);
+                vma = vma->vm_next;
+        }
 }
 
 void force_flush_all(void)
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index cb3321f8e0a9..44e490419495 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -13,6 +13,7 @@
 #include "as-layout.h"
 #include "kern_util.h"
 #include "os.h"
+#include "skas.h"
 #include "sysdep/sigcontext.h"
 
 /*
@@ -128,7 +129,19 @@ static void bad_segv(struct faultinfo fi, unsigned long ip)
         force_sig_info(SIGSEGV, &si, current);
 }
 
-static void segv_handler(int sig, struct uml_pt_regs *regs)
+void fatal_sigsegv(void)
+{
+        force_sigsegv(SIGSEGV, current);
+        do_signal();
+        /*
+         * This is to tell gcc that we're not returning - do_signal
+         * can, in general, return, but in this case, it's not, since
+         * we just got a fatal SIGSEGV queued.
+         */
+        os_dump_core();
+}
+
+void segv_handler(int sig, struct uml_pt_regs *regs)
 {
         struct faultinfo * fi = UPT_FAULTINFO(regs);
 
@@ -216,9 +229,6 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 
 void relay_signal(int sig, struct uml_pt_regs *regs)
 {
-        if (arch_handle_signal(sig, regs))
-                return;
-
         if (!UPT_IS_USER(regs)) {
                 if (sig == SIGBUS)
                         printk(KERN_ERR "Bus error - the host /dev/shm or /tmp "
@@ -226,31 +236,24 @@ void relay_signal(int sig, struct uml_pt_regs *regs)
                 panic("Kernel mode signal %d", sig);
         }
 
+        arch_examine_signal(sig, regs);
+
         current->thread.arch.faultinfo = *UPT_FAULTINFO(regs);
         force_sig(sig, current);
 }
 
-static void bus_handler(int sig, struct uml_pt_regs *regs)
+void bus_handler(int sig, struct uml_pt_regs *regs)
 {
         if (current->thread.fault_catcher != NULL)
                 UML_LONGJMP(current->thread.fault_catcher, 1);
         else relay_signal(sig, regs);
 }
 
-static void winch(int sig, struct uml_pt_regs *regs)
+void winch(int sig, struct uml_pt_regs *regs)
 {
         do_IRQ(WINCH_IRQ, regs);
 }
 
-const struct kern_handlers handlinfo_kern = {
-        .relay_signal = relay_signal,
-        .winch = winch,
-        .bus_handler = bus_handler,
-        .page_fault = segv_handler,
-        .sigio_handler = sigio_handler,
-        .timer_handler = timer_handler
-};
-
 void trap_init(void)
 {
 }
diff --git a/arch/um/kernel/uaccess.c b/arch/um/kernel/uaccess.c
index d7436aacd26f..f0f4b040d7c5 100644
--- a/arch/um/kernel/uaccess.c
+++ b/arch/um/kernel/uaccess.c
@@ -1,10 +1,11 @@
 /*
  * Copyright (C) 2001 Chris Emerson (cemerson@chiark.greenend.org.uk)
- * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
-/* These are here rather than tt/uaccess.c because skas mode needs them in
+/*
+ * These are here rather than tt/uaccess.c because skas mode needs them in
  * order to do SIGBUS recovery when a tmpfs mount runs out of room.
  */
 
@@ -25,6 +26,8 @@ int __do_copy_to_user(void *to, const void *from, int n,
 
         fault = __do_user_copy(to, from, n, fault_addr, fault_catcher,
                                __do_copy, &faulted);
-        if(!faulted) return(0);
-        else return(n - (fault - (unsigned long) to));
+        if (!faulted)
+                return 0;
+        else
+                return n - (fault - (unsigned long) to);
 }
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index f1c71393f578..468aba990dbd 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -3,22 +3,23 @@
  * Licensed under the GPL
  */
 
-#include "linux/delay.h"
-#include "linux/mm.h"
-#include "linux/module.h"
-#include "linux/seq_file.h"
-#include "linux/string.h"
-#include "linux/utsname.h"
-#include "asm/pgtable.h"
-#include "asm/processor.h"
-#include "asm/setup.h"
-#include "arch.h"
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <linux/string.h>
+#include <linux/utsname.h>
+#include <asm/pgtable.h>
+#include <asm/processor.h>
+#include <asm/setup.h>
 #include "as-layout.h"
+#include "arch.h"
 #include "init.h"
 #include "kern.h"
+#include "kern_util.h"
 #include "mem_user.h"
 #include "os.h"
-#include "skas.h"
 
 #define DEFAULT_COMMAND_LINE "root=98:0"
 
@@ -100,8 +101,6 @@ const struct seq_operations cpuinfo_op = {
 };
 
 /* Set in linux_main */
-unsigned long host_task_size;
-unsigned long task_size;
 unsigned long uml_physmem;
 unsigned long uml_reserved; /* Also modified in mem_init */
 unsigned long start_vm;
@@ -197,20 +196,19 @@ __uml_setup("--help", Usage,
 "    Prints this message.\n\n"
 );
 
-static int __init uml_checksetup(char *line, int *add)
+static void __init uml_checksetup(char *line, int *add)
 {
         struct uml_param *p;
 
         p = &__uml_setup_start;
-        while(p < &__uml_setup_end) {
+        while (p < &__uml_setup_end) {
                 int n;
 
                 n = strlen(p->str);
                 if (!strncmp(line, p->str, n) && p->setup_func(line + n, add))
-                        return 1;
+                        return;
                 p++;
         }
-        return 0;
 }
 
 static void __init uml_postsetup(void)
@@ -218,13 +216,30 @@ static void __init uml_postsetup(void)
         initcall_t *p;
 
         p = &__uml_postsetup_start;
-        while(p < &__uml_postsetup_end) {
+        while (p < &__uml_postsetup_end) {
                 (*p)();
                 p++;
         }
         return;
 }
 
+static int panic_exit(struct notifier_block *self, unsigned long unused1,
+                      void *unused2)
+{
+        bust_spinlocks(1);
+        show_regs(&(current->thread.regs));
+        bust_spinlocks(0);
+        uml_exitcode = 1;
+        os_dump_core();
+        return 0;
+}
+
+static struct notifier_block panic_exit_notifier = {
+        .notifier_call          = panic_exit,
+        .next                   = NULL,
+        .priority               = 0
+};
+
 /* Set during early boot */
 unsigned long brk_start;
 unsigned long end_iomem;
@@ -234,20 +249,6 @@ EXPORT_SYMBOL(end_iomem);
 
 extern char __binary_start;
 
-static unsigned long set_task_sizes_skas(unsigned long *task_size_out)
-{
-        /* Round up to the nearest 4M */
-        unsigned long host_task_size = ROUND_4M((unsigned long)
-                                                &host_task_size);
-
-        if (!skas_needs_stub)
-                *task_size_out = host_task_size;
-        else
-                *task_size_out = STUB_START & PGDIR_MASK;
-
-        return host_task_size;
-}
-
 int __init linux_main(int argc, char **argv)
 {
         unsigned long avail, diff;
@@ -278,13 +279,6 @@ int __init linux_main(int argc, char **argv)
 
         printf("UML running in %s mode\n", mode);
 
-        host_task_size = set_task_sizes_skas(&task_size);
-
-        /*
-         * Setting up handlers to 'sig_info' struct
-         */
-        os_fill_handlinfo(handlinfo_kern);
-
         brk_start = (unsigned long) sbrk(0);
 
         /*
@@ -309,7 +303,7 @@ int __init linux_main(int argc, char **argv)
 
         highmem = 0;
         iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
-        max_physmem = get_kmem_end() - uml_physmem - iomem_size - MIN_VMALLOC;
+        max_physmem = CONFIG_TOP_ADDR - uml_physmem - iomem_size - MIN_VMALLOC;
 
         /*
          * Zones have to begin on a 1 << MAX_ORDER page boundary,
@@ -341,7 +335,7 @@ int __init linux_main(int argc, char **argv)
         }
 
         virtmem_size = physmem_size;
-        avail = get_kmem_end() - start_vm;
+        avail = CONFIG_TOP_ADDR - start_vm;
         if (physmem_size > avail)
                 virtmem_size = avail;
         end_vm = start_vm + virtmem_size;
@@ -350,6 +344,9 @@ int __init linux_main(int argc, char **argv)
                 printf("Kernel virtual memory size shrunk to %lu bytes\n",
                        virtmem_size);
 
+        atomic_notifier_chain_register(&panic_notifier_list,
+                                       &panic_exit_notifier);
+
         uml_postsetup();
 
         stack_protections((unsigned long) &init_thread_info);
@@ -358,29 +355,8 @@ int __init linux_main(int argc, char **argv)
         return start_uml();
 }
 
-extern int uml_exitcode;
-
-static int panic_exit(struct notifier_block *self, unsigned long unused1,
-                      void *unused2)
-{
-        bust_spinlocks(1);
-        show_regs(&(current->thread.regs));
-        bust_spinlocks(0);
-        uml_exitcode = 1;
-        os_dump_core();
-        return 0;
-}
-
-static struct notifier_block panic_exit_notifier = {
-        .notifier_call          = panic_exit,
-        .next                   = NULL,
-        .priority               = 0
-};
-
 void __init setup_arch(char **cmdline_p)
 {
-        atomic_notifier_chain_register(&panic_notifier_list,
-                        &panic_exit_notifier);
         paging_init();
         strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
         *cmdline_p = command_line;
diff --git a/arch/um/kernel/umid.c b/arch/um/kernel/umid.c
index 039e16efcd55..81e07e2be3ae 100644
--- a/arch/um/kernel/umid.c
+++ b/arch/um/kernel/umid.c
@@ -1,13 +1,12 @@
-/* 
- * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
+/*
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
-#include "asm/errno.h"
+#include <asm/errno.h>
 #include "init.h"
-#include "os.h"
 #include "kern.h"
-#include "linux/kernel.h"
+#include "os.h"
 
 /* Changed by set_umid_arg */
 static int umid_inited = 0;
@@ -16,16 +15,16 @@ static int __init set_umid_arg(char *name, int *add)
 {
         int err;
 
-        if(umid_inited){
+        if (umid_inited) {
                 printf("umid already set\n");
                 return 0;
         }
 
         *add = 0;
         err = set_umid(name);
-        if(err == -EEXIST)
+        if (err == -EEXIST)
                 printf("umid '%s' already in use\n", name);
-        else if(!err)
+        else if (!err)
                 umid_inited = 1;
 
         return 0;
diff --git a/arch/um/os-Linux/Makefile b/arch/um/os-Linux/Makefile
index 8e129af8170d..8a48d6a30064 100644
--- a/arch/um/os-Linux/Makefile
+++ b/arch/um/os-Linux/Makefile
@@ -4,7 +4,7 @@
 #
 
 obj-y = aio.o elf_aux.o execvp.o file.o helper.o irq.o main.o mem.o process.o \
-        registers.o sigio.o signal.o start_up.o time.o trap.o tty.o uaccess.o \
+        registers.o sigio.o signal.o start_up.o time.o tty.o uaccess.o \
         umid.o tls.o user_syms.o util.o drivers/ sys-$(SUBARCH)/ skas/
 
 obj-$(CONFIG_TTY_LOG) += tty_log.o
@@ -12,7 +12,7 @@ user-objs-$(CONFIG_TTY_LOG) += tty_log.o
 
 USER_OBJS := $(user-objs-y) aio.o elf_aux.o execvp.o file.o helper.o irq.o \
         main.o mem.o process.o registers.o sigio.o signal.o start_up.o time.o \
-        trap.o tty.o tls.o uaccess.o umid.o util.o
+        tty.o tls.o uaccess.o umid.o util.o
 
 CFLAGS_user_syms.o += -DSUBARCH_$(SUBARCH)
 
diff --git a/arch/um/os-Linux/aio.c b/arch/um/os-Linux/aio.c
index 93dc0c80ebaf..b8d8c9ca8d4a 100644
--- a/arch/um/os-Linux/aio.c
+++ b/arch/um/os-Linux/aio.c
@@ -12,6 +12,7 @@
 #include "aio.h"
 #include "init.h"
 #include "kern_constants.h"
+#include "kern_util.h"
 #include "os.h"
 #include "user.h"
 
diff --git a/arch/um/os-Linux/drivers/ethertap_user.c b/arch/um/os-Linux/drivers/ethertap_user.c
index 07ca0cb472ac..6fb0b174f538 100644
--- a/arch/um/os-Linux/drivers/ethertap_user.c
+++ b/arch/um/os-Linux/drivers/ethertap_user.c
@@ -131,7 +131,7 @@ static int etap_tramp(char *dev, char *gate, int control_me,
         }
         if (c != 1) {
                 printk(UM_KERN_ERR "etap_tramp : uml_net failed\n");
-                err = helper_wait(pid, 0, "uml_net");
+                err = helper_wait(pid);
         }
         return err;
 }
diff --git a/arch/um/os-Linux/drivers/tuntap_user.c b/arch/um/os-Linux/drivers/tuntap_user.c
index 1037a3b6386e..2448be03fd7a 100644
--- a/arch/um/os-Linux/drivers/tuntap_user.c
+++ b/arch/um/os-Linux/drivers/tuntap_user.c
@@ -14,6 +14,7 @@
 #include <sys/wait.h>
 #include <sys/uio.h>
 #include "kern_constants.h"
+#include "kern_util.h"
 #include "os.h"
 #include "tuntap.h"
 #include "user.h"
@@ -107,7 +108,7 @@ static int tuntap_open_tramp(char *gate, int *fd_out, int me, int remote,
                        "errno = %d\n", errno);
                 return err;
         }
-        helper_wait(pid, 0, "tuntap_open_tramp");
+        helper_wait(pid);
 
         cmsg = CMSG_FIRSTHDR(&msg);
         if (cmsg == NULL) {
@@ -148,7 +149,7 @@ static int tuntap_open(void *data)
                 memset(&ifr, 0, sizeof(ifr));
                 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
                 strlcpy(ifr.ifr_name, pri->dev_name, sizeof(ifr.ifr_name));
-                if (ioctl(pri->fd, TUNSETIFF, (void *) &ifr) < 0) {
+                if (ioctl(pri->fd, TUNSETIFF, &ifr) < 0) {
                         err = -errno;
                         printk(UM_KERN_ERR "TUNSETIFF failed, errno = %d\n",
                                errno);
diff --git a/arch/um/os-Linux/file.c b/arch/um/os-Linux/file.c
index f83462758627..b5afcfd0f861 100644
--- a/arch/um/os-Linux/file.c
+++ b/arch/um/os-Linux/file.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
@@ -8,18 +8,16 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/socket.h>
-#include <sys/un.h>
 #include <sys/ioctl.h>
 #include <sys/mount.h>
-#include <sys/uio.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/un.h>
+#include "kern_constants.h"
 #include "os.h"
 #include "user.h"
-#include "kern_util.h"
 
-static void copy_stat(struct uml_stat *dst, struct stat64 *src)
+static void copy_stat(struct uml_stat *dst, const struct stat64 *src)
 {
         *dst = ((struct uml_stat) {
                 .ust_dev     = src->st_dev,     /* device */
@@ -43,10 +41,10 @@ int os_stat_fd(const int fd, struct uml_stat *ubuf)
         int err;
 
         CATCH_EINTR(err = fstat64(fd, &sbuf));
-        if(err < 0)
+        if (err < 0)
                 return -errno;
 
-        if(ubuf != NULL)
+        if (ubuf != NULL)
                 copy_stat(ubuf, &sbuf);
         return err;
 }
@@ -56,27 +54,26 @@ int os_stat_file(const char *file_name, struct uml_stat *ubuf)
         struct stat64 sbuf;
         int err;
 
-        do {
-                err = stat64(file_name, &sbuf);
-        } while((err < 0) && (errno == EINTR)) ;
-
-        if(err < 0)
+        CATCH_EINTR(err = stat64(file_name, &sbuf));
+        if (err < 0)
                 return -errno;
 
-        if(ubuf != NULL)
+        if (ubuf != NULL)
                 copy_stat(ubuf, &sbuf);
         return err;
 }
 
-int os_access(const char* file, int mode)
+int os_access(const char *file, int mode)
 {
         int amode, err;
 
-        amode=(mode&OS_ACC_R_OK ? R_OK : 0) | (mode&OS_ACC_W_OK ? W_OK : 0) |
-              (mode&OS_ACC_X_OK ? X_OK : 0) | (mode&OS_ACC_F_OK ? F_OK : 0) ;
+        amode = (mode & OS_ACC_R_OK ? R_OK : 0) |
+                (mode & OS_ACC_W_OK ? W_OK : 0) |
+                (mode & OS_ACC_X_OK ? X_OK : 0) |
+                (mode & OS_ACC_F_OK ? F_OK : 0);
 
         err = access(file, amode);
-        if(err < 0)
+        if (err < 0)
                 return -errno;
 
         return 0;
@@ -88,7 +85,7 @@ int os_ioctl_generic(int fd, unsigned int cmd, unsigned long arg)
         int err;
 
         err = ioctl(fd, cmd, arg);
-        if(err < 0)
+        if (err < 0)
                 return -errno;
 
         return err;
@@ -97,7 +94,7 @@ int os_ioctl_generic(int fd, unsigned int cmd, unsigned long arg)
 /* FIXME: ensure namebuf in os_get_if_name is big enough */
 int os_get_ifname(int fd, char* namebuf)
 {
-        if(ioctl(fd, SIOCGIFNAME, namebuf) < 0)
+        if (ioctl(fd, SIOCGIFNAME, namebuf) < 0)
                 return -errno;
 
         return 0;
@@ -108,37 +105,22 @@ int os_set_slip(int fd)
         int disc, sencap;
 
         disc = N_SLIP;
-        if(ioctl(fd, TIOCSETD, &disc) < 0)
+        if (ioctl(fd, TIOCSETD, &disc) < 0)
                 return -errno;
 
         sencap = 0;
-        if(ioctl(fd, SIOCSIFENCAP, &sencap) < 0)
+        if (ioctl(fd, SIOCSIFENCAP, &sencap) < 0)
                 return -errno;
 
         return 0;
 }
 
-int os_set_owner(int fd, int pid)
-{
-        if(fcntl(fd, F_SETOWN, pid) < 0){
-                int save_errno = errno;
-
-                if(fcntl(fd, F_GETOWN, 0) != pid)
-                        return -save_errno;
-        }
-
-        return 0;
-}
-
 int os_mode_fd(int fd, int mode)
 {
         int err;
 
-        do {
-                err = fchmod(fd, mode);
-        } while((err < 0) && (errno==EINTR)) ;
-
-        if(err < 0)
+        CATCH_EINTR(err = fchmod(fd, mode));
+        if (err < 0)
                 return -errno;
 
         return 0;
@@ -150,64 +132,73 @@ int os_file_type(char *file)
         int err;
 
         err = os_stat_file(file, &buf);
-        if(err < 0)
+        if (err < 0)
                 return err;
 
-        if(S_ISDIR(buf.ust_mode))
+        if (S_ISDIR(buf.ust_mode))
                 return OS_TYPE_DIR;
-        else if(S_ISLNK(buf.ust_mode))
+        else if (S_ISLNK(buf.ust_mode))
                 return OS_TYPE_SYMLINK;
-        else if(S_ISCHR(buf.ust_mode))
+        else if (S_ISCHR(buf.ust_mode))
                 return OS_TYPE_CHARDEV;
-        else if(S_ISBLK(buf.ust_mode))
+        else if (S_ISBLK(buf.ust_mode))
                 return OS_TYPE_BLOCKDEV;
-        else if(S_ISFIFO(buf.ust_mode))
+        else if (S_ISFIFO(buf.ust_mode))
                 return OS_TYPE_FIFO;
-        else if(S_ISSOCK(buf.ust_mode))
+        else if (S_ISSOCK(buf.ust_mode))
                 return OS_TYPE_SOCK;
         else return OS_TYPE_FILE;
 }
 
-int os_file_mode(char *file, struct openflags *mode_out)
+int os_file_mode(const char *file, struct openflags *mode_out)
 {
         int err;
 
         *mode_out = OPENFLAGS();
 
         err = access(file, W_OK);
-        if(err && (errno != EACCES))
+        if (err && (errno != EACCES))
                 return -errno;
-        else if(!err)
+        else if (!err)
                 *mode_out = of_write(*mode_out);
 
         err = access(file, R_OK);
-        if(err && (errno != EACCES))
+        if (err && (errno != EACCES))
                 return -errno;
-        else if(!err)
+        else if (!err)
                 *mode_out = of_read(*mode_out);
 
         return err;
 }
 
-int os_open_file(char *file, struct openflags flags, int mode)
+int os_open_file(const char *file, struct openflags flags, int mode)
 {
         int fd, err, f = 0;
 
-        if(flags.r && flags.w) f = O_RDWR;
-        else if(flags.r) f = O_RDONLY;
-        else if(flags.w) f = O_WRONLY;
+        if (flags.r && flags.w)
+                f = O_RDWR;
+        else if (flags.r)
+                f = O_RDONLY;
+        else if (flags.w)
+                f = O_WRONLY;
         else f = 0;
 
-        if(flags.s) f |= O_SYNC;
-        if(flags.c) f |= O_CREAT;
-        if(flags.t) f |= O_TRUNC;
-        if(flags.e) f |= O_EXCL;
+        if (flags.s)
+                f |= O_SYNC;
+        if (flags.c)
+                f |= O_CREAT;
+        if (flags.t)
+                f |= O_TRUNC;
+        if (flags.e)
+                f |= O_EXCL;
+        if (flags.a)
+                f |= O_APPEND;
 
         fd = open64(file, f, mode);
-        if(fd < 0)
+        if (fd < 0)
                 return -errno;
 
-        if(flags.cl && fcntl(fd, F_SETFD, 1)){
+        if (flags.cl && fcntl(fd, F_SETFD, 1)) {
                 err = -errno;
                 close(fd);
                 return err;
@@ -216,7 +207,7 @@ int os_open_file(char *file, struct openflags flags, int mode)
         return fd;
 }
 
-int os_connect_socket(char *name)
+int os_connect_socket(const char *name)
 {
         struct sockaddr_un sock;
         int fd, err;
@@ -225,13 +216,13 @@ int os_connect_socket(char *name)
         snprintf(sock.sun_path, sizeof(sock.sun_path), "%s", name);
 
         fd = socket(AF_UNIX, SOCK_STREAM, 0);
-        if(fd < 0) {
+        if (fd < 0) {
                 err = -errno;
                 goto out;
         }
 
         err = connect(fd, (struct sockaddr *) &sock, sizeof(sock));
-        if(err) {
+        if (err) {
                 err = -errno;
                 goto out_close;
         }
@@ -254,7 +245,7 @@ int os_seek_file(int fd, unsigned long long offset)
         unsigned long long actual;
 
         actual = lseek64(fd, offset, SEEK_SET);
-        if(actual != offset)
+        if (actual != offset)
                 return -errno;
         return 0;
 }
@@ -263,7 +254,7 @@ int os_read_file(int fd, void *buf, int len)
 {
         int n = read(fd, buf, len);
 
-        if(n < 0)
+        if (n < 0)
                 return -errno;
         return n;
 }
@@ -272,37 +263,38 @@ int os_write_file(int fd, const void *buf, int len)
 {
         int n = write(fd, (void *) buf, len);
 
-        if(n < 0)
+        if (n < 0)
                 return -errno;
         return n;
 }
 
-int os_file_size(char *file, unsigned long long *size_out)
+int os_file_size(const char *file, unsigned long long *size_out)
 {
         struct uml_stat buf;
         int err;
 
         err = os_stat_file(file, &buf);
-        if(err < 0){
-                printk("Couldn't stat \"%s\" : err = %d\n", file, -err);
+        if (err < 0) {
+                printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file,
+                       -err);
                 return err;
         }
 
-        if(S_ISBLK(buf.ust_mode)){
+        if (S_ISBLK(buf.ust_mode)) {
                 int fd;
                 long blocks;
 
                 fd = open(file, O_RDONLY, 0);
-                if(fd < 0) {
+                if (fd < 0) {
                         err = -errno;
-                        printk("Couldn't open \"%s\", errno = %d\n", file,
-                               errno);
+                        printk(UM_KERN_ERR "Couldn't open \"%s\", "
+                               "errno = %d\n", file, errno);
                         return err;
                 }
-                if(ioctl(fd, BLKGETSIZE, &blocks) < 0){
+                if (ioctl(fd, BLKGETSIZE, &blocks) < 0) {
                         err = -errno;
-                        printk("Couldn't get the block size of \"%s\", "
-                               "errno = %d\n", file, errno);
+                        printk(UM_KERN_ERR "Couldn't get the block size of "
+                               "\"%s\", errno = %d\n", file, errno);
                         close(fd);
                         return err;
                 }
@@ -314,14 +306,15 @@ int os_file_size(char *file, unsigned long long *size_out)
         return 0;
 }
 
-int os_file_modtime(char *file, unsigned long *modtime)
+int os_file_modtime(const char *file, unsigned long *modtime)
 {
         struct uml_stat buf;
         int err;
 
         err = os_stat_file(file, &buf);
-        if(err < 0){
-                printk("Couldn't stat \"%s\" : err = %d\n", file, -err);
+        if (err < 0) {
+                printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file,
+                       -err);
                 return err;
         }
 
@@ -329,26 +322,13 @@ int os_file_modtime(char *file, unsigned long *modtime)
         return 0;
 }
 
-int os_get_exec_close(int fd, int *close_on_exec)
-{
-        int ret;
-
-        CATCH_EINTR(ret = fcntl(fd, F_GETFD));
-
-        if(ret < 0)
-                return -errno;
-
-        *close_on_exec = (ret & FD_CLOEXEC) ? 1 : 0;
-        return ret;
-}
-
 int os_set_exec_close(int fd)
 {
         int err;
 
         CATCH_EINTR(err = fcntl(fd, F_SETFD, FD_CLOEXEC));
 
-        if(err < 0)
+        if (err < 0)
                 return -errno;
         return err;
 }
@@ -358,53 +338,51 @@ int os_pipe(int *fds, int stream, int close_on_exec)
         int err, type = stream ? SOCK_STREAM : SOCK_DGRAM;
 
         err = socketpair(AF_UNIX, type, 0, fds);
-        if(err < 0)
+        if (err < 0)
                 return -errno;
 
-        if(!close_on_exec)
+        if (!close_on_exec)
                 return 0;
 
         err = os_set_exec_close(fds[0]);
-        if(err < 0)
+        if (err < 0)
                 goto error;
 
         err = os_set_exec_close(fds[1]);
-        if(err < 0)
+        if (err < 0)
                 goto error;
 
         return 0;
 
  error:
-        printk("os_pipe : Setting FD_CLOEXEC failed, err = %d\n", -err);
+        printk(UM_KERN_ERR "os_pipe : Setting FD_CLOEXEC failed, err = %d\n",
+               -err);
         close(fds[1]);
         close(fds[0]);
         return err;
 }
 
-int os_set_fd_async(int fd, int owner)
+int os_set_fd_async(int fd)
 {
-        int err;
+        int err, flags;
+
+        flags = fcntl(fd, F_GETFL);
+        if (flags < 0)
+                return -errno;
 
-        /* XXX This should do F_GETFL first */
-        if(fcntl(fd, F_SETFL, O_ASYNC | O_NONBLOCK) < 0){
+        flags |= O_ASYNC | O_NONBLOCK;
+        if (fcntl(fd, F_SETFL, flags) < 0) {
                 err = -errno;
-                printk("os_set_fd_async : failed to set O_ASYNC and "
-                       "O_NONBLOCK on fd # %d, errno = %d\n", fd, errno);
+                printk(UM_KERN_ERR "os_set_fd_async : failed to set O_ASYNC "
+                       "and O_NONBLOCK on fd # %d, errno = %d\n", fd, errno);
                 return err;
         }
-#ifdef notdef
-        if(fcntl(fd, F_SETFD, 1) < 0){
-                printk("os_set_fd_async : Setting FD_CLOEXEC failed, "
-                       "errno = %d\n", errno);
-        }
-#endif
 
-        if((fcntl(fd, F_SETSIG, SIGIO) < 0) ||
-           (fcntl(fd, F_SETOWN, owner) < 0)){
+        if ((fcntl(fd, F_SETSIG, SIGIO) < 0) ||
+            (fcntl(fd, F_SETOWN, os_getpid()) < 0)) {
                 err = -errno;
-                printk("os_set_fd_async : Failed to fcntl F_SETOWN "
-                       "(or F_SETSIG) fd %d to pid %d, errno = %d\n", fd,
-                       owner, errno);
+                printk(UM_KERN_ERR "os_set_fd_async : Failed to fcntl F_SETOWN "
+                       "(or F_SETSIG) fd %d, errno = %d\n", fd, errno);
                 return err;
         }
 
@@ -413,10 +391,14 @@ int os_set_fd_async(int fd, int owner)
 
 int os_clear_fd_async(int fd)
 {
-        int flags = fcntl(fd, F_GETFL);
+        int flags;
+
+        flags = fcntl(fd, F_GETFL);
+        if (flags < 0)
+                return -errno;
 
         flags &= ~(O_ASYNC | O_NONBLOCK);
-        if(fcntl(fd, F_SETFL, flags) < 0)
+        if (fcntl(fd, F_SETFL, flags) < 0)
                 return -errno;
         return 0;
 }
@@ -426,11 +408,15 @@ int os_set_fd_block(int fd, int blocking)
         int flags;
 
         flags = fcntl(fd, F_GETFL);
+        if (flags < 0)
+                return -errno;
 
-        if(blocking) flags &= ~O_NONBLOCK;
-        else flags |= O_NONBLOCK;
+        if (blocking)
+                flags &= ~O_NONBLOCK;
+        else
+                flags |= O_NONBLOCK;
 
-        if(fcntl(fd, F_SETFL, flags) < 0)
+        if (fcntl(fd, F_SETFL, flags) < 0)
                 return -errno;
 
         return 0;
@@ -441,7 +427,7 @@ int os_accept_connection(int fd)
         int new;
 
         new = accept(fd, NULL, 0);
-        if(new < 0)
+        if (new < 0)
                 return -errno;
         return new;
 }
@@ -462,15 +448,17 @@ int os_shutdown_socket(int fd, int r, int w)
 {
         int what, err;
 
-        if(r && w) what = SHUT_RDWR;
-        else if(r) what = SHUT_RD;
-        else if(w) what = SHUT_WR;
-        else {
-                printk("os_shutdown_socket : neither r or w was set\n");
+        if (r && w)
+                what = SHUT_RDWR;
+        else if (r)
+                what = SHUT_RD;
+        else if (w)
+                what = SHUT_WR;
+        else
                 return -EINVAL;
-        }
+
         err = shutdown(fd, what);
-        if(err < 0)
+        if (err < 0)
                 return -errno;
         return 0;
 }
@@ -494,19 +482,20 @@ int os_rcv_fd(int fd, int *helper_pid_out)
         msg.msg_flags = 0;
 
         n = recvmsg(fd, &msg, 0);
-        if(n < 0)
+        if (n < 0)
                 return -errno;
-        else if(n != iov.iov_len)
+        else if (n != iov.iov_len)
                 *helper_pid_out = -1;
 
         cmsg = CMSG_FIRSTHDR(&msg);
-        if(cmsg == NULL){
-                printk("rcv_fd didn't receive anything, error = %d\n", errno);
+        if (cmsg == NULL) {
+                printk(UM_KERN_ERR "rcv_fd didn't receive anything, "
+                       "error = %d\n", errno);
                 return -1;
         }
-        if((cmsg->cmsg_level != SOL_SOCKET) ||
-           (cmsg->cmsg_type != SCM_RIGHTS)){
-                printk("rcv_fd didn't receive a descriptor\n");
+        if ((cmsg->cmsg_level != SOL_SOCKET) ||
+            (cmsg->cmsg_type != SCM_RIGHTS)) {
+                printk(UM_KERN_ERR "rcv_fd didn't receive a descriptor\n");
                 return -1;
         }
 
@@ -514,29 +503,28 @@ int os_rcv_fd(int fd, int *helper_pid_out)
         return new;
 }
 
-int os_create_unix_socket(char *file, int len, int close_on_exec)
+int os_create_unix_socket(const char *file, int len, int close_on_exec)
 {
         struct sockaddr_un addr;
         int sock, err;
 
         sock = socket(PF_UNIX, SOCK_DGRAM, 0);
-        if(sock < 0)
+        if (sock < 0)
                 return -errno;
 
-        if(close_on_exec) {
+        if (close_on_exec) {
                 err = os_set_exec_close(sock);
-                if(err < 0)
-                        printk("create_unix_socket : close_on_exec failed, "
-                       "err = %d", -err);
+                if (err < 0)
+                        printk(UM_KERN_ERR "create_unix_socket : "
+                               "close_on_exec failed, err = %d", -err);
         }
 
         addr.sun_family = AF_UNIX;
 
-        /* XXX Be more careful about overflow */
         snprintf(addr.sun_path, len, "%s", file);
 
         err = bind(sock, (struct sockaddr *) &addr, sizeof(addr));
-        if(err < 0)
+        if (err < 0)
                 return -errno;
 
         return sock;
@@ -557,17 +545,18 @@ int os_lock_file(int fd, int excl)
         int err, save;
 
         err = fcntl(fd, F_SETLK, &lock);
-        if(!err)
+        if (!err)
                 goto out;
 
         save = -errno;
         err = fcntl(fd, F_GETLK, &lock);
-        if(err){
+        if (err) {
                 err = -errno;
                 goto out;
         }
 
-        printk("F_SETLK failed, file already locked by pid %d\n", lock.l_pid);
+        printk(UM_KERN_ERR "F_SETLK failed, file already locked by pid %d\n",
+               lock.l_pid);
         err = save;
  out:
         return err;
diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c
index fba3f0fefeef..f4bd349d4412 100644
--- a/arch/um/os-Linux/helper.c
+++ b/arch/um/os-Linux/helper.c
@@ -1,22 +1,19 @@
 /*
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
-#include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <errno.h>
 #include <sched.h>
-#include <limits.h>
-#include <sys/signal.h>
-#include <sys/wait.h>
 #include <sys/socket.h>
-#include "user.h"
+#include <sys/wait.h>
+#include "kern_constants.h"
 #include "kern_util.h"
 #include "os.h"
 #include "um_malloc.h"
-#include "kern_constants.h"
+#include "user.h"
 
 struct helper_data {
         void (*pre_exec)(void*);
@@ -30,21 +27,19 @@ static int helper_child(void *arg)
 {
         struct helper_data *data = arg;
         char **argv = data->argv;
-        int errval;
+        int err;
 
         if (data->pre_exec != NULL)
                 (*data->pre_exec)(data->pre_data);
-        errval = execvp_noalloc(data->buf, argv[0], argv);
-        printk("helper_child - execvp of '%s' failed - errno = %d\n", argv[0],
-               -errval);
-        write(data->fd, &errval, sizeof(errval));
-        kill(os_getpid(), SIGKILL);
+        err = execvp_noalloc(data->buf, argv[0], argv);
+
+        /* If the exec succeeds, we don't get here */
+        write(data->fd, &err, sizeof(err));
+
         return 0;
 }
 
-/* Returns either the pid of the child process we run or -E* on failure.
- * XXX The alloc_stack here breaks if this is called in the tracing thread, so
- * we need to receive a preallocated stack (a local buffer is ok). */
+/* Returns either the pid of the child process we run or -E* on failure. */
 int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv)
 {
         struct helper_data data;
@@ -58,14 +53,15 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv)
         ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fds);
         if (ret < 0) {
                 ret = -errno;
-                printk("run_helper : pipe failed, errno = %d\n", errno);
+                printk(UM_KERN_ERR "run_helper : pipe failed, errno = %d\n",
+                       errno);
                 goto out_free;
         }
 
         ret = os_set_exec_close(fds[1]);
         if (ret < 0) {
-                printk("run_helper : setting FD_CLOEXEC failed, ret = %d\n",
-                       -ret);
+                printk(UM_KERN_ERR "run_helper : setting FD_CLOEXEC failed, "
+                       "ret = %d\n", -ret);
                 goto out_close;
         }
 
@@ -79,7 +75,8 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv)
         pid = clone(helper_child, (void *) sp, CLONE_VM, &data);
         if (pid < 0) {
                 ret = -errno;
-                printk("run_helper : clone failed, errno = %d\n", errno);
+                printk(UM_KERN_ERR "run_helper : clone failed, errno = %d\n",
+                       errno);
                 goto out_free2;
         }
 
@@ -96,10 +93,9 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv)
         } else {
                 if (n < 0) {
                         n = -errno;
-                        printk("run_helper : read on pipe failed, ret = %d\n",
-                               -n);
+                        printk(UM_KERN_ERR "run_helper : read on pipe failed, "
+                               "ret = %d\n", -n);
                         ret = n;
-                        kill(pid, SIGKILL);
                 }
                 CATCH_EINTR(waitpid(pid, NULL, __WCLONE));
         }
@@ -129,50 +125,40 @@ int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags,
         pid = clone(proc, (void *) sp, flags, arg);
         if (pid < 0) {
                 err = -errno;
-                printk("run_helper_thread : clone failed, errno = %d\n",
-                       errno);
+                printk(UM_KERN_ERR "run_helper_thread : clone failed, "
+                       "errno = %d\n", errno);
                 return err;
         }
         if (stack_out == NULL) {
                 CATCH_EINTR(pid = waitpid(pid, &status, __WCLONE));
                 if (pid < 0) {
                         err = -errno;
-                        printk("run_helper_thread - wait failed, errno = %d\n",
-                               errno);
+                        printk(UM_KERN_ERR "run_helper_thread - wait failed, "
+                               "errno = %d\n", errno);
                         pid = err;
                 }
                 if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0))
-                        printk("run_helper_thread - thread returned status "
-                               "0x%x\n", status);
+                        printk(UM_KERN_ERR "run_helper_thread - thread "
+                               "returned status 0x%x\n", status);
                 free_stack(stack, 0);
         } else
                 *stack_out = stack;
         return pid;
 }
 
-int helper_wait(int pid, int nohang, char *pname)
+int helper_wait(int pid)
 {
         int ret, status;
         int wflags = __WCLONE;
 
-        if (nohang)
-                wflags |= WNOHANG;
-
-        if (!pname)
-                pname = "helper_wait";
-
         CATCH_EINTR(ret = waitpid(pid, &status, wflags));
         if (ret < 0) {
-                printk(UM_KERN_ERR "%s : waitpid process %d failed, "
-                       "errno = %d\n", pname, pid, errno);
+                printk(UM_KERN_ERR "helper_wait : waitpid process %d failed, "
+                       "errno = %d\n", pid, errno);
                 return -errno;
-        } else if (nohang && ret == 0) {
-                printk(UM_KERN_ERR "%s : process %d has not exited\n",
-                       pname, pid);
-                return -ECHILD;
         } else if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
-                printk(UM_KERN_ERR "%s : process %d didn't exit with "
-                       "status 0\n", pname, pid);
+                printk(UM_KERN_ERR "helper_wait : process %d exited with "
+                       "status 0x%x\n", pid, status);
                 return -ECHILD;
         } else
                 return 0;
diff --git a/arch/um/os-Linux/irq.c b/arch/um/os-Linux/irq.c
index 6aa6f95d6524..0348b975e81c 100644
--- a/arch/um/os-Linux/irq.c
+++ b/arch/um/os-Linux/irq.c
@@ -1,23 +1,19 @@
 /*
- * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
 #include <stdlib.h>
-#include <unistd.h>
 #include <errno.h>
+#include <poll.h>
 #include <signal.h>
 #include <string.h>
-#include <sys/poll.h>
-#include <sys/types.h>
-#include <sys/time.h>
-#include "kern_util.h"
-#include "user.h"
-#include "process.h"
-#include "sigio.h"
 #include "irq_user.h"
+#include "kern_constants.h"
 #include "os.h"
+#include "process.h"
 #include "um_malloc.h"
+#include "user.h"
 
 /*
  * Locked by irq_lock in arch/um/kernel/irq.c.  Changed by os_create_pollfd
@@ -36,7 +32,7 @@ int os_waiting_for_events(struct irq_fd *active_fds)
         if (n < 0) {
                 err = -errno;
                 if (errno != EINTR)
-                        printk("sigio_handler: os_waiting_for_events:"
+                        printk(UM_KERN_ERR "os_waiting_for_events:"
                                " poll returned %d, errno = %d\n", n, errno);
                 return err;
         }
@@ -95,24 +91,26 @@ void os_free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg,
                         struct irq_fd *old_fd = *prev;
                         if ((pollfds[i].fd != -1) &&
                             (pollfds[i].fd != (*prev)->fd)) {
-                                printk("os_free_irq_by_cb - mismatch between "
-                                       "active_fds and pollfds, fd %d vs %d\n",
+                                printk(UM_KERN_ERR "os_free_irq_by_cb - "
+                                       "mismatch between active_fds and "
+                                       "pollfds, fd %d vs %d\n",
                                        (*prev)->fd, pollfds[i].fd);
                                 goto out;
                         }
 
                         pollfds_num--;
 
-                        /* This moves the *whole* array after pollfds[i]
+                        /*
+                         * This moves the *whole* array after pollfds[i]
                          * (though it doesn't spot as such)!
                          */
                         memmove(&pollfds[i], &pollfds[i + 1],
                                (pollfds_num - i) * sizeof(pollfds[0]));
-                        if(*last_irq_ptr2 == &old_fd->next)
+                        if (*last_irq_ptr2 == &old_fd->next)
                                 *last_irq_ptr2 = prev;
 
                         *prev = (*prev)->next;
-                        if(old_fd->type == IRQ_WRITE)
+                        if (old_fd->type == IRQ_WRITE)
                                 ignore_sigio_fd(old_fd->fd);
                         kfree(old_fd);
                         continue;
@@ -138,14 +136,3 @@ void os_set_ioignore(void)
 {
         signal(SIGIO, SIG_IGN);
 }
-
-void init_irq_signals(int on_sigstack)
-{
-        int flags;
-
-        flags = on_sigstack ? SA_ONSTACK : 0;
-
-        set_handler(SIGIO, (__sighandler_t) sig_handler, flags | SA_RESTART,
-                    SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
-        signal(SIGWINCH, SIG_IGN);
-}
diff --git a/arch/um/os-Linux/main.c b/arch/um/os-Linux/main.c
index 82c3778627b8..abb9b0ffd960 100644
--- a/arch/um/os-Linux/main.c
+++ b/arch/um/os-Linux/main.c
@@ -73,7 +73,7 @@ static void install_fatal_handler(int sig)
         action.sa_handler = last_ditch_exit;
         if (sigaction(sig, &action, NULL) < 0) {
                 printf("failed to install handler for signal %d - errno = %d\n",
-                       errno);
+                       sig, errno);
                 exit(1);
         }
 }
@@ -92,7 +92,8 @@ static void setup_env_path(void)
          * just use the default + /usr/lib/uml
          */
         if (!old_path || (path_len = strlen(old_path)) == 0) {
-                putenv("PATH=:/bin:/usr/bin/" UML_LIB_PATH);
+                if (putenv("PATH=:/bin:/usr/bin/" UML_LIB_PATH))
+                        perror("couldn't putenv");
                 return;
         }
 
@@ -100,15 +101,16 @@ static void setup_env_path(void)
         path_len += strlen("PATH=" UML_LIB_PATH) + 1;
         new_path = malloc(path_len);
         if (!new_path) {
-                perror("coudn't malloc to set a new PATH");
+                perror("couldn't malloc to set a new PATH");
                 return;
         }
         snprintf(new_path, path_len, "PATH=%s" UML_LIB_PATH, old_path);
-        putenv(new_path);
+        if (putenv(new_path)) {
+                perror("couldn't putenv to set a new PATH");
+                free(new_path);
+        }
 }
 
-extern int uml_exitcode;
-
 extern void scan_elf_aux( char **envp);
 
 int __init main(int argc, char **argv, char **envp)
diff --git a/arch/um/os-Linux/mem.c b/arch/um/os-Linux/mem.c
index 436f8d20b20f..eedc2d88ef8a 100644
--- a/arch/um/os-Linux/mem.c
+++ b/arch/um/os-Linux/mem.c
@@ -9,7 +9,6 @@
 #include <sys/types.h>
 #include <sys/mman.h>
 #include <sys/statfs.h>
-#include "kern_util.h"
 #include "user.h"
 #include "mem_user.h"
 #include "init.h"
@@ -30,7 +29,7 @@ static char *tempdir = NULL;
 
 static void __init find_tempdir(void)
 {
-        char *dirs[] = { "TMP", "TEMP", "TMPDIR", NULL };
+        const char *dirs[] = { "TMP", "TEMP", "TMPDIR", NULL };
         int i;
         char *dir = NULL;
 
@@ -59,9 +58,10 @@ static void __init find_tempdir(void)
  * read the file as needed.  If there's an error, -errno is returned;
  * if the end of the file is reached, 0 is returned.
  */
-static int next(int fd, char *buf, int size, char c)
+static int next(int fd, char *buf, size_t size, char c)
 {
-        int n, len;
+        ssize_t n;
+        size_t len;
         char *ptr;
 
         while((ptr = strchr(buf, c)) == NULL){
@@ -172,13 +172,15 @@ int __init make_tempfile(const char *template, char **out_tempname,
 
         which_tmpdir();
         tempname = malloc(MAXPATHLEN);
+        if (!tempname)
+                goto out;
 
         find_tempdir();
         if (template[0] != '/')
                 strcpy(tempname, tempdir);
         else
                 tempname[0] = '\0';
-        strcat(tempname, template);
+        strncat(tempname, template, MAXPATHLEN-1-strlen(tempname));
         fd = mkstemp(tempname);
         if(fd < 0){
                 fprintf(stderr, "open - cannot create %s: %s\n", tempname,
@@ -268,6 +270,7 @@ void __init check_tmpexec(void)
         if(addr == MAP_FAILED){
                 err = errno;
                 perror("failed");
+                close(fd);
                 if(err == EPERM)
                         printf("%s must be not mounted noexec\n",tempdir);
                 exit(1);
diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c
index bda5c3150d6c..abf6beae3df1 100644
--- a/arch/um/os-Linux/process.c
+++ b/arch/um/os-Linux/process.c
@@ -249,7 +249,10 @@ void init_new_thread_signals(void)
                     SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
         signal(SIGHUP, SIG_IGN);
 
-        init_irq_signals(1);
+        set_handler(SIGIO, (__sighandler_t) sig_handler,
+                    SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGALRM,
+                    SIGVTALRM, -1);
+        signal(SIGWINCH, SIG_IGN);
 }
 
 int run_kernel_thread(int (*fn)(void *), void *arg, jmp_buf **jmp_ptr)
diff --git a/arch/um/os-Linux/registers.c b/arch/um/os-Linux/registers.c
index a32ba6ab1211..830fe6a1518a 100644
--- a/arch/um/os-Linux/registers.c
+++ b/arch/um/os-Linux/registers.c
@@ -8,47 +8,41 @@
 #include <string.h>
 #include <sys/ptrace.h>
 #include "sysdep/ptrace.h"
-#include "user.h"
 
-/* This is set once at boot time and not changed thereafter */
-
-static unsigned long exec_regs[MAX_REG_NR];
-
-void init_thread_registers(struct uml_pt_regs *to)
-{
-        memcpy(to->gp, exec_regs, sizeof(to->gp));
-}
-
-void save_registers(int pid, struct uml_pt_regs *regs)
+int save_registers(int pid, struct uml_pt_regs *regs)
 {
         int err;
 
         err = ptrace(PTRACE_GETREGS, pid, 0, regs->gp);
         if (err < 0)
-                panic("save_registers - saving registers failed, errno = %d\n",
-                      errno);
+                return -errno;
+        return 0;
 }
 
-void restore_registers(int pid, struct uml_pt_regs *regs)
+int restore_registers(int pid, struct uml_pt_regs *regs)
 {
         int err;
 
         err = ptrace(PTRACE_SETREGS, pid, 0, regs->gp);
         if (err < 0)
-                panic("restore_registers - saving registers failed, "
-                      "errno = %d\n", errno);
+                return -errno;
+        return 0;
 }
 
-void init_registers(int pid)
+/* This is set once at boot time and not changed thereafter */
+
+static unsigned long exec_regs[MAX_REG_NR];
+
+int init_registers(int pid)
 {
         int err;
 
         err = ptrace(PTRACE_GETREGS, pid, 0, exec_regs);
-        if (err)
-                panic("check_ptrace : PTRACE_GETREGS failed, errno = %d",
-                      errno);
+        if (err < 0)
+                return -errno;
 
         arch_init_registers(pid);
+        return 0;
 }
 
 void get_safe_registers(unsigned long *regs)
diff --git a/arch/um/os-Linux/sigio.c b/arch/um/os-Linux/sigio.c
index dc03e9cccb63..abf47a7c4abd 100644
--- a/arch/um/os-Linux/sigio.c
+++ b/arch/um/os-Linux/sigio.c
@@ -1,34 +1,33 @@
 /*
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
 #include <unistd.h>
-#include <stdlib.h>
-#include <termios.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <poll.h>
 #include <pty.h>
+#include <sched.h>
 #include <signal.h>
-#include <fcntl.h>
-#include <errno.h>
 #include <string.h>
-#include <sched.h>
-#include <sys/socket.h>
-#include <sys/poll.h>
-#include "init.h"
-#include "user.h"
+#include "kern_constants.h"
 #include "kern_util.h"
-#include "sigio.h"
+#include "init.h"
 #include "os.h"
+#include "sigio.h"
 #include "um_malloc.h"
-#include "init.h"
+#include "user.h"
 
-/* Protected by sigio_lock(), also used by sigio_cleanup, which is an
+/*
+ * Protected by sigio_lock(), also used by sigio_cleanup, which is an
  * exitcall.
  */
 static int write_sigio_pid = -1;
 static unsigned long write_sigio_stack;
 
-/* These arrays are initialized before the sigio thread is started, and
+/*
+ * These arrays are initialized before the sigio thread is started, and
  * the descriptors closed after it is killed.  So, it can't see them change.
  * On the UML side, they are changed under the sigio_lock.
  */
@@ -43,7 +42,8 @@ struct pollfds {
         int used;
 };
 
-/* Protected by sigio_lock().  Used by the sigio thread, but the UML thread
+/*
+ * Protected by sigio_lock().  Used by the sigio thread, but the UML thread
  * synchronizes with it.
  */
 static struct pollfds current_poll;
@@ -57,23 +57,26 @@ static int write_sigio_thread(void *unused)
         int i, n, respond_fd;
         char c;
 
-        signal(SIGWINCH, SIG_IGN);
+        signal(SIGWINCH, SIG_IGN);
         fds = &current_poll;
-        while(1){
+        while (1) {
                 n = poll(fds->poll, fds->used, -1);
-                if(n < 0){
-                        if(errno == EINTR) continue;
-                        printk("write_sigio_thread : poll returned %d, "
-                               "errno = %d\n", n, errno);
+                if (n < 0) {
+                        if (errno == EINTR)
+                                continue;
+                        printk(UM_KERN_ERR "write_sigio_thread : poll returned "
+                               "%d, errno = %d\n", n, errno);
                 }
-                for(i = 0; i < fds->used; i++){
+                for (i = 0; i < fds->used; i++) {
                         p = &fds->poll[i];
-                        if(p->revents == 0) continue;
-                        if(p->fd == sigio_private[1]){
+                        if (p->revents == 0)
+                                continue;
+                        if (p->fd == sigio_private[1]) {
                                 CATCH_EINTR(n = read(sigio_private[1], &c,
                                                      sizeof(c)));
-                                if(n != sizeof(c))
-                                        printk("write_sigio_thread : "
+                                if (n != sizeof(c))
+                                        printk(UM_KERN_ERR
+                                               "write_sigio_thread : "
                                                "read on socket failed, "
                                                "err = %d\n", errno);
                                 tmp = current_poll;
@@ -89,9 +92,10 @@ static int write_sigio_thread(void *unused)
                         }
 
                         CATCH_EINTR(n = write(respond_fd, &c, sizeof(c)));
-                        if(n != sizeof(c))
-                                printk("write_sigio_thread : write on socket "
-                                       "failed, err = %d\n", errno);
+                        if (n != sizeof(c))
+                                printk(UM_KERN_ERR "write_sigio_thread : "
+                                       "write on socket failed, err = %d\n",
+                                       errno);
                 }
         }
 
@@ -102,12 +106,13 @@ static int need_poll(struct pollfds *polls, int n)
 {
         struct pollfd *new;
 
-        if(n <= polls->size)
+        if (n <= polls->size)
                 return 0;
 
         new = kmalloc(n * sizeof(struct pollfd), UM_GFP_ATOMIC);
-        if(new == NULL){
-                printk("need_poll : failed to allocate new pollfds\n");
+        if (new == NULL) {
+                printk(UM_KERN_ERR "need_poll : failed to allocate new "
+                       "pollfds\n");
                 return -ENOMEM;
         }
 
@@ -119,7 +124,8 @@ static int need_poll(struct pollfds *polls, int n)
         return 0;
 }
 
-/* Must be called with sigio_lock held, because it's needed by the marked
+/*
+ * Must be called with sigio_lock held, because it's needed by the marked
  * critical section.
  */
 static void update_thread(void)
@@ -129,15 +135,17 @@ static void update_thread(void)
         char c;
 
         flags = set_signals(0);
-        n = write(sigio_private[0], &c, sizeof(c));
-        if(n != sizeof(c)){
-                printk("update_thread : write failed, err = %d\n", errno);
+        CATCH_EINTR(n = write(sigio_private[0], &c, sizeof(c)));
+        if (n != sizeof(c)) {
+                printk(UM_KERN_ERR "update_thread : write failed, err = %d\n",
+                       errno);
                 goto fail;
         }
 
         CATCH_EINTR(n = read(sigio_private[0], &c, sizeof(c)));
-        if(n != sizeof(c)){
-                printk("update_thread : read failed, err = %d\n", errno);
+        if (n != sizeof(c)) {
+                printk(UM_KERN_ERR "update_thread : read failed, err = %d\n",
+                       errno);
                 goto fail;
         }
 
@@ -164,23 +172,23 @@ int add_sigio_fd(int fd)
         int err = 0, i, n;
 
         sigio_lock();
-        for(i = 0; i < all_sigio_fds.used; i++){
-                if(all_sigio_fds.poll[i].fd == fd)
+        for (i = 0; i < all_sigio_fds.used; i++) {
+                if (all_sigio_fds.poll[i].fd == fd)
                         break;
         }
-        if(i == all_sigio_fds.used)
+        if (i == all_sigio_fds.used)
                 goto out;
 
         p = &all_sigio_fds.poll[i];
 
-        for(i = 0; i < current_poll.used; i++){
-                if(current_poll.poll[i].fd == fd)
+        for (i = 0; i < current_poll.used; i++) {
+                if (current_poll.poll[i].fd == fd)
                         goto out;
         }
 
         n = current_poll.used;
         err = need_poll(&next_poll, n + 1);
-        if(err)
+        if (err)
                 goto out;
 
         memcpy(next_poll.poll, current_poll.poll,
@@ -198,27 +206,29 @@ int ignore_sigio_fd(int fd)
         struct pollfd *p;
         int err = 0, i, n = 0;
 
-        /* This is called from exitcalls elsewhere in UML - if
+        /*
+         * This is called from exitcalls elsewhere in UML - if
          * sigio_cleanup has already run, then update_thread will hang
          * or fail because the thread is no longer running.
          */
-        if(write_sigio_pid == -1)
+        if (write_sigio_pid == -1)
                 return -EIO;
 
         sigio_lock();
-        for(i = 0; i < current_poll.used; i++){
-                if(current_poll.poll[i].fd == fd) break;
+        for (i = 0; i < current_poll.used; i++) {
+                if (current_poll.poll[i].fd == fd)
+                        break;
         }
-        if(i == current_poll.used)
+        if (i == current_poll.used)
                 goto out;
 
         err = need_poll(&next_poll, current_poll.used - 1);
-        if(err)
+        if (err)
                 goto out;
 
-        for(i = 0; i < current_poll.used; i++){
+        for (i = 0; i < current_poll.used; i++) {
                 p = &current_poll.poll[i];
-                if(p->fd != fd)
+                if (p->fd != fd)
                         next_poll.poll[n++] = *p;
         }
         next_poll.used = current_poll.used - 1;
@@ -235,7 +245,8 @@ static struct pollfd *setup_initial_poll(int fd)
 
         p = kmalloc(sizeof(struct pollfd), UM_GFP_KERNEL);
         if (p == NULL) {
-                printk("setup_initial_poll : failed to allocate poll\n");
+                printk(UM_KERN_ERR "setup_initial_poll : failed to allocate "
+                       "poll\n");
                 return NULL;
         }
         *p = ((struct pollfd) { .fd             = fd,
@@ -261,27 +272,29 @@ static void write_sigio_workaround(void)
                 return;
 
         err = os_pipe(l_write_sigio_fds, 1, 1);
-        if(err < 0){
-                printk("write_sigio_workaround - os_pipe 1 failed, "
+        if (err < 0) {
+                printk(UM_KERN_ERR "write_sigio_workaround - os_pipe 1 failed, "
                        "err = %d\n", -err);
                 return;
         }
         err = os_pipe(l_sigio_private, 1, 1);
-        if(err < 0){
-                printk("write_sigio_workaround - os_pipe 2 failed, "
+        if (err < 0) {
+                printk(UM_KERN_ERR "write_sigio_workaround - os_pipe 2 failed, "
                        "err = %d\n", -err);
                 goto out_close1;
         }
 
         p = setup_initial_poll(l_sigio_private[1]);
-        if(!p)
+        if (!p)
                 goto out_close2;
 
         sigio_lock();
 
-        /* Did we race? Don't try to optimize this, please, it's not so likely
-         * to happen, and no more than once at the boot. */
-        if(write_sigio_pid != -1)
+        /*
+         * Did we race? Don't try to optimize this, please, it's not so likely
+         * to happen, and no more than once at the boot.
+         */
+        if (write_sigio_pid != -1)
                 goto out_free;
 
         current_poll = ((struct pollfds) { .poll        = p,
@@ -333,19 +346,19 @@ void maybe_sigio_broken(int fd, int read)
 {
         int err;
 
-        if(!isatty(fd))
+        if (!isatty(fd))
                 return;
 
-        if((read || pty_output_sigio) && (!read || pty_close_sigio))
+        if ((read || pty_output_sigio) && (!read || pty_close_sigio))
                 return;
 
         write_sigio_workaround();
 
         sigio_lock();
         err = need_poll(&all_sigio_fds, all_sigio_fds.used + 1);
-        if(err){
-                printk("maybe_sigio_broken - failed to add pollfd for "
-                       "descriptor %d\n", fd);
+        if (err) {
+                printk(UM_KERN_ERR "maybe_sigio_broken - failed to add pollfd "
+                       "for descriptor %d\n", fd);
                 goto out;
         }
 
@@ -388,7 +401,7 @@ static void openpty_cb(void *arg)
         struct openpty_arg *info = arg;
 
         info->err = 0;
-        if(openpty(&info->master, &info->slave, NULL, NULL, NULL))
+        if (openpty(&info->master, &info->slave, NULL, NULL, NULL))
                 info->err = -errno;
 }
 
@@ -397,17 +410,17 @@ static int async_pty(int master, int slave)
         int flags;
 
         flags = fcntl(master, F_GETFL);
-        if(flags < 0)
+        if (flags < 0)
                 return -errno;
 
-        if((fcntl(master, F_SETFL, flags | O_NONBLOCK | O_ASYNC) < 0) ||
-           (fcntl(master, F_SETOWN, os_getpid()) < 0))
+        if ((fcntl(master, F_SETFL, flags | O_NONBLOCK | O_ASYNC) < 0) ||
+            (fcntl(master, F_SETOWN, os_getpid()) < 0))
                 return -errno;
 
-        if((fcntl(slave, F_SETFL, flags | O_NONBLOCK) < 0))
+        if ((fcntl(slave, F_SETFL, flags | O_NONBLOCK) < 0))
                 return -errno;
 
-        return(0);
+        return 0;
 }
 
 static void __init check_one_sigio(void (*proc)(int, int))
@@ -417,34 +430,49 @@ static void __init check_one_sigio(void (*proc)(int, int))
         int master, slave, err;
 
         initial_thread_cb(openpty_cb, &pty);
-        if(pty.err){
-                printk("openpty failed, errno = %d\n", -pty.err);
+        if (pty.err) {
+                printk(UM_KERN_ERR "check_one_sigio failed, errno = %d\n",
+                       -pty.err);
                 return;
         }
 
         master = pty.master;
         slave = pty.slave;
 
-        if((master == -1) || (slave == -1)){
-                printk("openpty failed to allocate a pty\n");
+        if ((master == -1) || (slave == -1)) {
+                printk(UM_KERN_ERR "check_one_sigio failed to allocate a "
+                       "pty\n");
                 return;
         }
 
         /* Not now, but complain so we now where we failed. */
         err = raw(master);
-        if (err < 0)
-                panic("check_sigio : __raw failed, errno = %d\n", -err);
+        if (err < 0) {
+                printk(UM_KERN_ERR "check_one_sigio : raw failed, errno = %d\n",
+                      -err);
+                return;
+        }
 
         err = async_pty(master, slave);
-        if(err < 0)
-                panic("tty_fds : sigio_async failed, err = %d\n", -err);
+        if (err < 0) {
+                printk(UM_KERN_ERR "check_one_sigio : sigio_async failed, "
+                       "err = %d\n", -err);
+                return;
+        }
+
+        if (sigaction(SIGIO, NULL, &old) < 0) {
+                printk(UM_KERN_ERR "check_one_sigio : sigaction 1 failed, "
+                       "errno = %d\n", errno);
+                return;
+        }
 
-        if(sigaction(SIGIO, NULL, &old) < 0)
-                panic("check_sigio : sigaction 1 failed, errno = %d\n", errno);
         new = old;
         new.sa_handler = handler;
-        if(sigaction(SIGIO, &new, NULL) < 0)
-                panic("check_sigio : sigaction 2 failed, errno = %d\n", errno);
+        if (sigaction(SIGIO, &new, NULL) < 0) {
+                printk(UM_KERN_ERR "check_one_sigio : sigaction 2 failed, "
+                       "errno = %d\n", errno);
+                return;
+        }
 
         got_sigio = 0;
         (*proc)(master, slave);
@@ -452,8 +480,9 @@ static void __init check_one_sigio(void (*proc)(int, int))
         close(master);
         close(slave);
 
-        if(sigaction(SIGIO, &old, NULL) < 0)
-                panic("check_sigio : sigaction 3 failed, errno = %d\n", errno);
+        if (sigaction(SIGIO, &old, NULL) < 0)
+                printk(UM_KERN_ERR "check_one_sigio : sigaction 3 failed, "
+                       "errno = %d\n", errno);
 }
 
 static void tty_output(int master, int slave)
@@ -461,42 +490,45 @@ static void tty_output(int master, int slave)
         int n;
         char buf[512];
 
-        printk("Checking that host ptys support output SIGIO...");
+        printk(UM_KERN_INFO "Checking that host ptys support output SIGIO...");
 
         memset(buf, 0, sizeof(buf));
 
-        while(write(master, buf, sizeof(buf)) > 0) ;
-        if(errno != EAGAIN)
-                panic("tty_output : write failed, errno = %d\n", errno);
-        while(((n = read(slave, buf, sizeof(buf))) > 0) && !got_sigio) ;
+        while (write(master, buf, sizeof(buf)) > 0) ;
+        if (errno != EAGAIN)
+                printk(UM_KERN_ERR "tty_output : write failed, errno = %d\n",
+                       errno);
+        while (((n = read(slave, buf, sizeof(buf))) > 0) && !got_sigio)
+                ;
 
-        if(got_sigio){
-                printk("Yes\n");
+        if (got_sigio) {
+                printk(UM_KERN_CONT "Yes\n");
                 pty_output_sigio = 1;
-        }
-        else if(n == -EAGAIN)
-                printk("No, enabling workaround\n");
-        else panic("tty_output : read failed, err = %d\n", n);
+        } else if (n == -EAGAIN)
+                printk(UM_KERN_CONT "No, enabling workaround\n");
+        else
+                printk(UM_KERN_CONT "tty_output : read failed, err = %d\n", n);
 }
 
 static void tty_close(int master, int slave)
 {
-        printk("Checking that host ptys support SIGIO on close...");
+        printk(UM_KERN_INFO "Checking that host ptys support SIGIO on "
+               "close...");
 
         close(slave);
-        if(got_sigio){
-                printk("Yes\n");
+        if (got_sigio) {
+                printk(UM_KERN_CONT "Yes\n");
                 pty_close_sigio = 1;
-        }
-        else printk("No, enabling workaround\n");
+        } else
+                printk(UM_KERN_CONT "No, enabling workaround\n");
 }
 
 void __init check_sigio(void)
 {
-        if((os_access("/dev/ptmx", OS_ACC_R_OK) < 0) &&
-           (os_access("/dev/ptyp0", OS_ACC_R_OK) < 0)){
-                printk("No pseudo-terminals available - skipping pty SIGIO "
-                       "check\n");
+        if ((access("/dev/ptmx", R_OK) < 0) &&
+            (access("/dev/ptyp0", R_OK) < 0)) {
+                printk(UM_KERN_WARNING "No pseudo-terminals available - "
+                       "skipping pty SIGIO check\n");
                 return;
         }
         check_one_sigio(tty_output);
diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c
index e9800b0b5689..0fb0cc8d4757 100644
--- a/arch/um/os-Linux/signal.c
+++ b/arch/um/os-Linux/signal.c
@@ -9,11 +9,47 @@
 #include <errno.h>
 #include <signal.h>
 #include <strings.h>
+#include "as-layout.h"
+#include "kern_util.h"
 #include "os.h"
 #include "sysdep/barrier.h"
 #include "sysdep/sigcontext.h"
 #include "user.h"
 
+/* Copied from linux/compiler-gcc.h since we can't include it directly */
+#define barrier() __asm__ __volatile__("": : :"memory")
+
+void (*sig_info[NSIG])(int, struct uml_pt_regs *) = {
+        [SIGTRAP]       = relay_signal,
+        [SIGFPE]        = relay_signal,
+        [SIGILL]        = relay_signal,
+        [SIGWINCH]      = winch,
+        [SIGBUS]        = bus_handler,
+        [SIGSEGV]       = segv_handler,
+        [SIGIO]         = sigio_handler,
+        [SIGVTALRM]     = timer_handler };
+
+static void sig_handler_common(int sig, struct sigcontext *sc)
+{
+        struct uml_pt_regs r;
+        int save_errno = errno;
+
+        r.is_user = 0;
+        if (sig == SIGSEGV) {
+                /* For segfaults, we want the data from the sigcontext. */
+                copy_sc(&r, sc);
+                GET_FAULTINFO_FROM_SC(r.faultinfo, sc);
+        }
+
+        /* enable signals if sig isn't IRQ signal */
+        if ((sig != SIGIO) && (sig != SIGWINCH) && (sig != SIGVTALRM))
+                unblock_signals();
+
+        (*sig_info[sig])(sig, &r);
+
+        errno = save_errno;
+}
+
 /*
  * These are the asynchronous signals.  SIGPROF is excluded because we want to
  * be able to profile all of UML, not just the non-critical sections.  If
@@ -26,13 +62,8 @@
 #define SIGVTALRM_BIT 1
 #define SIGVTALRM_MASK (1 << SIGVTALRM_BIT)
 
-/*
- * These are used by both the signal handlers and
- * block/unblock_signals.  I don't want modifications cached in a
- * register - they must go straight to memory.
- */
-static volatile int signals_enabled = 1;
-static volatile int pending = 0;
+static int signals_enabled;
+static unsigned int signals_pending;
 
 void sig_handler(int sig, struct sigcontext *sc)
 {
@@ -40,13 +71,13 @@ void sig_handler(int sig, struct sigcontext *sc)
 
         enabled = signals_enabled;
         if (!enabled && (sig == SIGIO)) {
-                pending |= SIGIO_MASK;
+                signals_pending |= SIGIO_MASK;
                 return;
         }
 
         block_signals();
 
-        sig_handler_common_skas(sig, sc);
+        sig_handler_common(sig, sc);
 
         set_signals(enabled);
 }
@@ -68,7 +99,7 @@ void alarm_handler(int sig, struct sigcontext *sc)
 
         enabled = signals_enabled;
         if (!signals_enabled) {
-                pending |= SIGVTALRM_MASK;
+                signals_pending |= SIGVTALRM_MASK;
                 return;
         }
 
@@ -94,16 +125,6 @@ void set_sigstack(void *sig_stack, int size)
                 panic("enabling signal stack failed, errno = %d\n", errno);
 }
 
-void remove_sigstack(void)
-{
-        stack_t stack = ((stack_t) { .ss_flags  = SS_DISABLE,
-                                     .ss_sp     = NULL,
-                                     .ss_size   = 0 });
-
-        if (sigaltstack(&stack, NULL) != 0)
-                panic("disabling signal stack failed, errno = %d\n", errno);
-}
-
 void (*handlers[_NSIG])(int sig, struct sigcontext *sc);
 
 void handle_signal(int sig, struct sigcontext *sc)
@@ -166,6 +187,9 @@ void set_handler(int sig, void (*handler)(int), int flags, ...)
                 sigaddset(&action.sa_mask, mask);
         va_end(ap);
 
+        if (sig == SIGSEGV)
+                flags |= SA_NODEFER;
+
         action.sa_flags = flags;
         action.sa_restorer = NULL;
         if (sigaction(sig, &action, NULL) < 0)
@@ -179,12 +203,14 @@ void set_handler(int sig, void (*handler)(int), int flags, ...)
 
 int change_sig(int signal, int on)
 {
-        sigset_t sigset, old;
+        sigset_t sigset;
 
         sigemptyset(&sigset);
         sigaddset(&sigset, signal);
-        sigprocmask(on ? SIG_UNBLOCK : SIG_BLOCK, &sigset, &old);
-        return !sigismember(&old, signal);
+        if (sigprocmask(on ? SIG_UNBLOCK : SIG_BLOCK, &sigset, NULL) < 0)
+                return -errno;
+
+        return 0;
 }
 
 void block_signals(void)
@@ -196,7 +222,7 @@ void block_signals(void)
          * This might matter if gcc figures out how to inline this and
          * decides to shuffle this code into the caller.
          */
-        mb();
+        barrier();
 }
 
 void unblock_signals(void)
@@ -209,36 +235,26 @@ void unblock_signals(void)
         /*
          * We loop because the IRQ handler returns with interrupts off.  So,
          * interrupts may have arrived and we need to re-enable them and
-         * recheck pending.
+         * recheck signals_pending.
          */
         while(1) {
                 /*
                  * Save and reset save_pending after enabling signals.  This
-                 * way, pending won't be changed while we're reading it.
+                 * way, signals_pending won't be changed while we're reading it.
                  */
                 signals_enabled = 1;
 
                 /*
-                 * Setting signals_enabled and reading pending must
+                 * Setting signals_enabled and reading signals_pending must
                  * happen in this order.
                  */
-                mb();
-
-                save_pending = pending;
-                if (save_pending == 0) {
-                        /*
-                         * This must return with signals enabled, so
-                         * this barrier ensures that writes are
-                         * flushed out before the return.  This might
-                         * matter if gcc figures out how to inline
-                         * this (unlikely, given its size) and decides
-                         * to shuffle this code into the caller.
-                         */
-                        mb();
+                barrier();
+
+                save_pending = signals_pending;
+                if (save_pending == 0)
                         return;
-                }
 
-                pending = 0;
+                signals_pending = 0;
 
                 /*
                  * We have pending interrupts, so disable signals, as the
@@ -254,7 +270,7 @@ void unblock_signals(void)
                  * back here.
                  */
                 if (save_pending & SIGIO_MASK)
-                        sig_handler_common_skas(SIGIO, NULL);
+                        sig_handler_common(SIGIO, NULL);
 
                 if (save_pending & SIGVTALRM_MASK)
                         real_alarm_handler(NULL);
diff --git a/arch/um/os-Linux/skas/Makefile b/arch/um/os-Linux/skas/Makefile
index 5fd8d4dad66a..d2ea3409e072 100644
--- a/arch/um/os-Linux/skas/Makefile
+++ b/arch/um/os-Linux/skas/Makefile
@@ -1,10 +1,10 @@
 #
-# Copyright (C) 2002 - 2004 Jeff Dike (jdike@addtoit.com)
+# Copyright (C) 2002 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
 # Licensed under the GPL
 #
 
-obj-y := mem.o process.o trap.o
+obj-y := mem.o process.o
 
-USER_OBJS := mem.o process.o trap.o
+USER_OBJS := $(obj-y)
 
 include arch/um/scripts/Makefile.rules
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index e8b7a97e83d3..d36c89c24a45 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -15,6 +15,7 @@
 #include "as-layout.h"
 #include "chan_user.h"
 #include "kern_constants.h"
+#include "kern_util.h"
 #include "mem.h"
 #include "os.h"
 #include "process.h"
@@ -37,27 +38,27 @@ int is_skas_winch(int pid, int fd, void *data)
 
 static int ptrace_dump_regs(int pid)
 {
-        unsigned long regs[MAX_REG_NR];
-        int i;
+        unsigned long regs[MAX_REG_NR];
+        int i;
 
-        if (ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
-                return -errno;
+        if (ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
+                return -errno;
 
         printk(UM_KERN_ERR "Stub registers -\n");
         for (i = 0; i < ARRAY_SIZE(regs); i++)
                 printk(UM_KERN_ERR "\t%d - %lx\n", i, regs[i]);
 
-        return 0;
+        return 0;
 }
 
 /*
  * Signals that are OK to receive in the stub - we'll just continue it.
  * SIGWINCH will happen when UML is inside a detached screen.
  */
-#define STUB_SIG_MASK ((1 << SIGVTALRM) | (1 << SIGWINCH))
+#define STUB_SIG_MASK (1 << SIGVTALRM)
 
 /* Signals that the stub will finish with - anything else is an error */
-#define STUB_DONE_MASK ((1 << SIGUSR1) | (1 << SIGTRAP))
+#define STUB_DONE_MASK (1 << SIGTRAP)
 
 void wait_stub_done(int pid)
 {
@@ -72,9 +73,11 @@ void wait_stub_done(int pid)
                         break;
 
                 err = ptrace(PTRACE_CONT, pid, 0, 0);
-                if (err)
-                        panic("wait_stub_done : continue failed, errno = %d\n",
-                              errno);
+                if (err) {
+                        printk(UM_KERN_ERR "wait_stub_done : continue failed, "
+                               "errno = %d\n", errno);
+                        fatal_sigsegv();
+                }
         }
 
         if (((1 << WSTOPSIG(status)) & STUB_DONE_MASK) != 0)
@@ -85,8 +88,10 @@ bad_wait:
         if (err)
                 printk(UM_KERN_ERR "Failed to get registers from stub, "
                        "errno = %d\n", -err);
-        panic("wait_stub_done : failed to wait for SIGUSR1/SIGTRAP, pid = %d, "
-              "n = %d, errno = %d, status = 0x%x\n", pid, n, errno, status);
+        printk(UM_KERN_ERR "wait_stub_done : failed to wait for SIGTRAP, "
+               "pid = %d, n = %d, errno = %d, status = 0x%x\n", pid, n, errno,
+               status);
+        fatal_sigsegv();
 }
 
 extern unsigned long current_stub_stack(void);
@@ -97,9 +102,11 @@ void get_skas_faultinfo(int pid, struct faultinfo * fi)
 
         if (ptrace_faultinfo) {
                 err = ptrace(PTRACE_FAULTINFO, pid, 0, fi);
-                if (err)
-                        panic("get_skas_faultinfo - PTRACE_FAULTINFO failed, "
-                              "errno = %d\n", errno);
+                if (err) {
+                        printk(UM_KERN_ERR "get_skas_faultinfo - "
+                               "PTRACE_FAULTINFO failed, errno = %d\n", errno);
+                        fatal_sigsegv();
+                }
 
                 /* Special handling for i386, which has different structs */
                 if (sizeof(struct ptrace_faultinfo) < sizeof(struct faultinfo))
@@ -109,9 +116,11 @@ void get_skas_faultinfo(int pid, struct faultinfo * fi)
         }
         else {
                 err = ptrace(PTRACE_CONT, pid, 0, SIGSEGV);
-                if (err)
-                        panic("Failed to continue stub, pid = %d, errno = %d\n",
-                              pid, errno);
+                if (err) {
+                        printk(UM_KERN_ERR "Failed to continue stub, pid = %d, "
+                               "errno = %d\n", pid, errno);
+                        fatal_sigsegv();
+                }
                 wait_stub_done(pid);
 
                 /*
@@ -137,6 +146,9 @@ static void handle_trap(int pid, struct uml_pt_regs *regs,
 {
         int err, status;
 
+        if ((UPT_IP(regs) >= STUB_START) && (UPT_IP(regs) < STUB_END))
+                fatal_sigsegv();
+
         /* Mark this as a syscall */
         UPT_SYSCALL_NR(regs) = PT_SYSCALL_NR(regs->gp);
 
@@ -144,25 +156,31 @@ static void handle_trap(int pid, struct uml_pt_regs *regs,
         {
                 err = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET,
                              __NR_getpid);
-                if (err < 0)
-                        panic("handle_trap - nullifying syscall failed, "
-                              "errno = %d\n", errno);
+                if (err < 0) {
+                        printk(UM_KERN_ERR "handle_trap - nullifying syscall "
+                               "failed, errno = %d\n", errno);
+                        fatal_sigsegv();
+                }
 
                 err = ptrace(PTRACE_SYSCALL, pid, 0, 0);
-                if (err < 0)
-                        panic("handle_trap - continuing to end of syscall "
-                              "failed, errno = %d\n", errno);
+                if (err < 0) {
+                        printk(UM_KERN_ERR "handle_trap - continuing to end of "
+                               "syscall failed, errno = %d\n", errno);
+                        fatal_sigsegv();
+                }
 
                 CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED | __WALL));
                 if ((err < 0) || !WIFSTOPPED(status) ||
-                   (WSTOPSIG(status) != SIGTRAP + 0x80)) {
-                        err = ptrace_dump_regs(pid);
-                        if (err)
-                                printk(UM_KERN_ERR "Failed to get registers "
+                    (WSTOPSIG(status) != SIGTRAP + 0x80)) {
+                        err = ptrace_dump_regs(pid);
+                        if (err)
+                                printk(UM_KERN_ERR "Failed to get registers "
                                        "from process, errno = %d\n", -err);
-                        panic("handle_trap - failed to wait at end of syscall, "
-                              "errno = %d, status = %d\n", errno, status);
-                }
+                        printk(UM_KERN_ERR "handle_trap - failed to wait at "
+                               "end of syscall, errno = %d, status = %d\n",
+                               errno, status);
+                        fatal_sigsegv();
+                }
         }
 
         handle_syscall(regs);
@@ -178,10 +196,13 @@ static int userspace_tramp(void *stack)
         ptrace(PTRACE_TRACEME, 0, 0, 0);
 
         signal(SIGTERM, SIG_DFL);
+        signal(SIGWINCH, SIG_IGN);
         err = set_interval();
-        if (err)
-                panic("userspace_tramp - setting timer failed, errno = %d\n",
-                      err);
+        if (err) {
+                printk(UM_KERN_ERR "userspace_tramp - setting timer failed, "
+                       "errno = %d\n", err);
+                exit(1);
+        }
 
         if (!proc_mm) {
                 /*
@@ -221,16 +242,14 @@ static int userspace_tramp(void *stack)
 
                 set_sigstack((void *) STUB_DATA, UM_KERN_PAGE_SIZE);
                 sigemptyset(&sa.sa_mask);
-                sigaddset(&sa.sa_mask, SIGIO);
-                sigaddset(&sa.sa_mask, SIGWINCH);
-                sigaddset(&sa.sa_mask, SIGVTALRM);
-                sigaddset(&sa.sa_mask, SIGUSR1);
-                sa.sa_flags = SA_ONSTACK;
+                sa.sa_flags = SA_ONSTACK | SA_NODEFER;
                 sa.sa_handler = (void *) v;
                 sa.sa_restorer = NULL;
-                if (sigaction(SIGSEGV, &sa, NULL) < 0)
-                        panic("userspace_tramp - setting SIGSEGV handler "
-                              "failed - errno = %d\n", errno);
+                if (sigaction(SIGSEGV, &sa, NULL) < 0) {
+                        printk(UM_KERN_ERR "userspace_tramp - setting SIGSEGV "
+                               "handler failed - errno = %d\n", errno);
+                        exit(1);
+                }
         }
 
         kill(os_getpid(), SIGSTOP);
@@ -246,13 +265,18 @@ int start_userspace(unsigned long stub_stack)
 {
         void *stack;
         unsigned long sp;
-        int pid, status, n, flags;
+        int pid, status, n, flags, err;
 
         stack = mmap(NULL, UM_KERN_PAGE_SIZE,
                      PROT_READ | PROT_WRITE | PROT_EXEC,
                      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-        if (stack == MAP_FAILED)
-                panic("start_userspace : mmap failed, errno = %d", errno);
+        if (stack == MAP_FAILED) {
+                err = -errno;
+                printk(UM_KERN_ERR "start_userspace : mmap failed, "
+                       "errno = %d\n", errno);
+                return err;
+        }
+
         sp = (unsigned long) stack + UM_KERN_PAGE_SIZE - sizeof(void *);
 
         flags = CLONE_FILES;
@@ -262,29 +286,50 @@ int start_userspace(unsigned long stub_stack)
                 flags |= SIGCHLD;
 
         pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack);
-        if (pid < 0)
-                panic("start_userspace : clone failed, errno = %d", errno);
+        if (pid < 0) {
+                err = -errno;
+                printk(UM_KERN_ERR "start_userspace : clone failed, "
+                       "errno = %d\n", errno);
+                return err;
+        }
 
         do {
                 CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED | __WALL));
-                if (n < 0)
-                        panic("start_userspace : wait failed, errno = %d",
-                              errno);
+                if (n < 0) {
+                        err = -errno;
+                        printk(UM_KERN_ERR "start_userspace : wait failed, "
+                               "errno = %d\n", errno);
+                        goto out_kill;
+                }
         } while (WIFSTOPPED(status) && (WSTOPSIG(status) == SIGVTALRM));
 
-        if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
-                panic("start_userspace : expected SIGSTOP, got status = %d",
-                      status);
+        if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP)) {
+                err = -EINVAL;
+                printk(UM_KERN_ERR "start_userspace : expected SIGSTOP, got "
+                       "status = %d\n", status);
+                goto out_kill;
+        }
 
         if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL,
-                   (void *) PTRACE_O_TRACESYSGOOD) < 0)
-                panic("start_userspace : PTRACE_OLDSETOPTIONS failed, "
-                      "errno = %d\n", errno);
+                   (void *) PTRACE_O_TRACESYSGOOD) < 0) {
+                err = -errno;
+                printk(UM_KERN_ERR "start_userspace : PTRACE_OLDSETOPTIONS "
+                       "failed, errno = %d\n", errno);
+                goto out_kill;
+        }
 
-        if (munmap(stack, UM_KERN_PAGE_SIZE) < 0)
-                panic("start_userspace : munmap failed, errno = %d\n", errno);
+        if (munmap(stack, UM_KERN_PAGE_SIZE) < 0) {
+                err = -errno;
+                printk(UM_KERN_ERR "start_userspace : munmap failed, "
+                       "errno = %d\n", errno);
+                goto out_kill;
+        }
 
         return pid;
+
+ out_kill:
+        os_kill_ptraced_process(pid, 1);
+        return err;
 }
 
 void userspace(struct uml_pt_regs *regs)
@@ -302,7 +347,16 @@ void userspace(struct uml_pt_regs *regs)
         nsecs += os_nsecs();
 
         while (1) {
-                restore_registers(pid, regs);
+                /*
+                 * This can legitimately fail if the process loads a
+                 * bogus value into a segment register.  It will
+                 * segfault and PTRACE_GETREGS will read that value
+                 * out of the process.  However, PTRACE_SETREGS will
+                 * fail.  In this case, there is nothing to do but
+                 * just kill the process.
+                 */
+                if (ptrace(PTRACE_SETREGS, pid, 0, regs->gp))
+                        fatal_sigsegv();
 
                 /* Now we set local_using_sysemu to be used for one loop */
                 local_using_sysemu = get_using_sysemu();
@@ -310,19 +364,26 @@ void userspace(struct uml_pt_regs *regs)
                 op = SELECT_PTRACE_OPERATION(local_using_sysemu,
                                              singlestepping(NULL));
 
-                err = ptrace(op, pid, 0, 0);
-                if (err)
-                        panic("userspace - could not resume userspace process, "
-                              "pid=%d, ptrace operation = %d, errno = %d\n",
-                              pid, op, errno);
+                if (ptrace(op, pid, 0, 0)) {
+                        printk(UM_KERN_ERR "userspace - ptrace continue "
+                               "failed, op = %d, errno = %d\n", op, errno);
+                        fatal_sigsegv();
+                }
 
                 CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED | __WALL));
-                if (err < 0)
-                        panic("userspace - waitpid failed, errno = %d\n",
-                              errno);
+                if (err < 0) {
+                        printk(UM_KERN_ERR "userspace - wait failed, "
+                               "errno = %d\n", errno);
+                        fatal_sigsegv();
+                }
 
                 regs->is_user = 1;
-                save_registers(pid, regs);
+                if (ptrace(PTRACE_GETREGS, pid, 0, regs->gp)) {
+                        printk(UM_KERN_ERR "userspace - PTRACE_GETREGS failed, "
+                               "errno = %d\n", errno);
+                        fatal_sigsegv();
+                }
+
                 UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */
 
                 if (WIFSTOPPED(status)) {
@@ -345,7 +406,7 @@ void userspace(struct uml_pt_regs *regs)
                                 break;
                         case SIGVTALRM:
                                 now = os_nsecs();
-                                if(now < nsecs)
+                                if (now < nsecs)
                                         break;
                                 block_signals();
                                 (*sig_info[sig])(sig, regs);
@@ -368,6 +429,7 @@ void userspace(struct uml_pt_regs *regs)
                         default:
                                 printk(UM_KERN_ERR "userspace - child stopped "
                                        "with signal %d\n", sig);
+                                fatal_sigsegv();
                         }
                         pid = userspace_pid[0];
                         interrupt_end();
@@ -419,9 +481,12 @@ int copy_context_skas0(unsigned long new_stack, int pid)
                                                      .it_interval = tv }) });
 
         err = ptrace_setregs(pid, thread_regs);
-        if (err < 0)
-                panic("copy_context_skas0 : PTRACE_SETREGS failed, "
-                      "pid = %d, errno = %d\n", pid, -err);
+        if (err < 0) {
+                err = -errno;
+                printk(UM_KERN_ERR "copy_context_skas0 : PTRACE_SETREGS "
+                       "failed, pid = %d, errno = %d\n", pid, -err);
+                return err;
+        }
 
         /* set a well known return code for detection of child write failure */
         child_data->err = 12345678;
@@ -431,31 +496,47 @@ int copy_context_skas0(unsigned long new_stack, int pid)
          * parent's stack, and check, if bad result.
          */
         err = ptrace(PTRACE_CONT, pid, 0, 0);
-        if (err)
-                panic("Failed to continue new process, pid = %d, "
-                      "errno = %d\n", pid, errno);
+        if (err) {
+                err = -errno;
+                printk(UM_KERN_ERR "Failed to continue new process, pid = %d, "
+                       "errno = %d\n", pid, errno);
+                return err;
+        }
+
         wait_stub_done(pid);
 
         pid = data->err;
-        if (pid < 0)
-                panic("copy_context_skas0 - stub-parent reports error %d\n",
-                      -pid);
+        if (pid < 0) {
+                printk(UM_KERN_ERR "copy_context_skas0 - stub-parent reports "
+                       "error %d\n", -pid);
+                return pid;
+        }
 
         /*
          * Wait, until child has finished too: read child's result from
          * child's stack and check it.
          */
         wait_stub_done(pid);
-        if (child_data->err != STUB_DATA)
-                panic("copy_context_skas0 - stub-child reports error %ld\n",
-                      child_data->err);
+        if (child_data->err != STUB_DATA) {
+                printk(UM_KERN_ERR "copy_context_skas0 - stub-child reports "
+                       "error %ld\n", child_data->err);
+                err = child_data->err;
+                goto out_kill;
+        }
 
         if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL,
-                   (void *)PTRACE_O_TRACESYSGOOD) < 0)
-                panic("copy_context_skas0 : PTRACE_OLDSETOPTIONS failed, "
-                      "errno = %d\n", errno);
+                   (void *)PTRACE_O_TRACESYSGOOD) < 0) {
+                err = -errno;
+                printk(UM_KERN_ERR "copy_context_skas0 : PTRACE_OLDSETOPTIONS "
+                       "failed, errno = %d\n", errno);
+                goto out_kill;
+        }
 
         return pid;
+
+ out_kill:
+        os_kill_ptraced_process(pid, 1);
+        return err;
 }
 
 /*
@@ -463,8 +544,8 @@ int copy_context_skas0(unsigned long new_stack, int pid)
  * available. 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)
+int map_stub_pages(int fd, unsigned long code, unsigned long data,
+                   unsigned long stack)
 {
         struct proc_mm_op mmop;
         int n;
@@ -488,8 +569,9 @@ void map_stub_pages(int fd, unsigned long code,
                 printk(UM_KERN_ERR "mmap args - addr = 0x%lx, fd = %d, "
                        "offset = %llx\n", code, code_fd,
                        (unsigned long long) code_offset);
-                panic("map_stub_pages : /proc/mm map for code failed, "
-                      "err = %d\n", n);
+                printk(UM_KERN_ERR "map_stub_pages : /proc/mm map for code "
+                       "failed, err = %d\n", n);
+                return -n;
         }
 
         if (stack) {
@@ -507,10 +589,15 @@ void map_stub_pages(int fd, unsigned long code,
                                       .offset  = map_offset
                 } } });
                 CATCH_EINTR(n = write(fd, &mmop, sizeof(mmop)));
-                if (n != sizeof(mmop))
-                        panic("map_stub_pages : /proc/mm map for data failed, "
-                              "err = %d\n", errno);
+                if (n != sizeof(mmop)) {
+                        n = errno;
+                        printk(UM_KERN_ERR "map_stub_pages : /proc/mm map for "
+                               "data failed, err = %d\n", n);
+                        return -n;
+                }
         }
+
+        return 0;
 }
 
 void new_thread(void *stack, jmp_buf *buf, void (*handler)(void))
@@ -571,7 +658,9 @@ int start_idle_thread(void *stack, jmp_buf *switch_buf)
                 kmalloc_ok = 0;
                 return 1;
         default:
-                panic("Bad sigsetjmp return in start_idle_thread - %d\n", n);
+                printk(UM_KERN_ERR "Bad sigsetjmp return in "
+                       "start_idle_thread - %d\n", n);
+                fatal_sigsegv();
         }
         longjmp(*switch_buf, 1);
 }
@@ -614,9 +703,11 @@ void __switch_mm(struct mm_id *mm_idp)
         if (proc_mm) {
                 err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0,
                              mm_idp->u.mm_fd);
-                if (err)
-                        panic("__switch_mm - PTRACE_SWITCH_MM failed, "
-                              "errno = %d\n", errno);
+                if (err) {
+                        printk(UM_KERN_ERR "__switch_mm - PTRACE_SWITCH_MM "
+                               "failed, errno = %d\n", errno);
+                        fatal_sigsegv();
+                }
         }
         else userspace_pid[0] = mm_idp->u.pid;
 }
diff --git a/arch/um/os-Linux/skas/trap.c b/arch/um/os-Linux/skas/trap.c
deleted file mode 100644
index 3b1b9244f468..000000000000
--- a/arch/um/os-Linux/skas/trap.c
+++ /dev/null
@@ -1,69 +0,0 @@
-/*
- * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
- */
-
-#if 0
-#include "kern_util.h"
-#include "skas.h"
-#include "ptrace_user.h"
-#include "sysdep/ptrace_user.h"
-#endif
-
-#include <errno.h>
-#include <signal.h>
-#include "sysdep/ptrace.h"
-#include "kern_constants.h"
-#include "as-layout.h"
-#include "os.h"
-#include "sigcontext.h"
-#include "task.h"
-
-static struct uml_pt_regs ksig_regs[UM_NR_CPUS];
-
-void sig_handler_common_skas(int sig, void *sc_ptr)
-{
-        struct sigcontext *sc = sc_ptr;
-        struct uml_pt_regs *r;
-        void (*handler)(int, struct uml_pt_regs *);
-        int save_user, save_errno = errno;
-
-        /*
-         * This is done because to allow SIGSEGV to be delivered inside a SEGV
-         * handler.  This can happen in copy_user, and if SEGV is disabled,
-         * the process will die.
-         * XXX Figure out why this is better than SA_NODEFER
-         */
-        if (sig == SIGSEGV) {
-                change_sig(SIGSEGV, 1);
-                /*
-                 * For segfaults, we want the data from the
-                 * sigcontext.  In this case, we don't want to mangle
-                 * the process registers, so use a static set of
-                 * registers.  For other signals, the process
-                 * registers are OK.
-                 */
-                r = &ksig_regs[cpu()];
-                copy_sc(r, sc_ptr);
-        }
-        else r = TASK_REGS(get_current());
-
-        save_user = r->is_user;
-        r->is_user = 0;
-        if ((sig == SIGFPE) || (sig == SIGSEGV) || (sig == SIGBUS) ||
-            (sig == SIGILL) || (sig == SIGTRAP))
-                GET_FAULTINFO_FROM_SC(r->faultinfo, sc);
-
-        change_sig(SIGUSR1, 1);
-
-        handler = sig_info[sig];
-
-        /* unblock SIGVTALRM, SIGIO if sig isn't IRQ signal */
-        if ((sig != SIGIO) && (sig != SIGWINCH) && (sig != SIGVTALRM))
-                unblock_signals();
-
-        handler(sig, r);
-
-        errno = save_errno;
-        r->is_user = save_user;
-}
diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c
index 7b81f6c08a5e..b616e15638fb 100644
--- a/arch/um/os-Linux/start_up.c
+++ b/arch/um/os-Linux/start_up.c
@@ -60,10 +60,11 @@ static int ptrace_child(void)
                  * the UML code itself.
                  */
                 ret = 2;
-        _exit(ret);
+
+        exit(ret);
 }
 
-static void fatal_perror(char *str)
+static void fatal_perror(const char *str)
 {
         perror(str);
         exit(1);
@@ -341,6 +342,8 @@ static void __init check_coredump_limit(void)
 
 void __init os_early_checks(void)
 {
+        int pid;
+
         /* Print out the core dump limits early */
         check_coredump_limit();
 
@@ -350,6 +353,11 @@ void __init os_early_checks(void)
          * kernel is running.
          */
         check_tmpexec();
+
+        pid = start_ptraced_child();
+        if (init_registers(pid))
+                fatal("Failed to initialize default registers");
+        stop_ptraced_child(pid, 1, 1);
 }
 
 static int __init noprocmm_cmd_param(char *str, int* add)
@@ -411,7 +419,6 @@ static inline void check_skas3_ptrace_faultinfo(void)
                         non_fatal("found\n");
         }
 
-        init_registers(pid);
         stop_ptraced_child(pid, 1, 1);
 }
 
@@ -466,7 +473,7 @@ static inline void check_skas3_proc_mm(void)
         else non_fatal("found\n");
 }
 
-int can_do_skas(void)
+void can_do_skas(void)
 {
         non_fatal("Checking for the skas3 patch in the host:\n");
 
@@ -476,8 +483,6 @@ int can_do_skas(void)
 
         if (!proc_mm || !ptrace_faultinfo || !ptrace_ldt)
                 skas_needs_stub = 1;
-
-        return 1;
 }
 
 int __init parse_iomem(char *str, int *add)
diff --git a/arch/um/os-Linux/trap.c b/arch/um/os-Linux/trap.c
deleted file mode 100644
index 2a1c9843e32e..000000000000
--- a/arch/um/os-Linux/trap.c
+++ /dev/null
@@ -1,23 +0,0 @@
-/*
- * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
- */
-
-#include <signal.h>
-#include "os.h"
-#include "sysdep/ptrace.h"
-
-/* Initialized from linux_main() */
-void (*sig_info[NSIG])(int, struct uml_pt_regs *);
-
-void os_fill_handlinfo(struct kern_handlers h)
-{
-        sig_info[SIGTRAP] = h.relay_signal;
-        sig_info[SIGFPE] = h.relay_signal;
-        sig_info[SIGILL] = h.relay_signal;
-        sig_info[SIGWINCH] = h.winch;
-        sig_info[SIGBUS] = h.bus_handler;
-        sig_info[SIGSEGV] = h.page_fault;
-        sig_info[SIGIO] = h.sigio_handler;
-        sig_info[SIGVTALRM] = h.timer_handler;
-}
diff --git a/arch/um/os-Linux/tty.c b/arch/um/os-Linux/tty.c
index 4cfdd18ea1ef..b09ff66a77ee 100644
--- a/arch/um/os-Linux/tty.c
+++ b/arch/um/os-Linux/tty.c
@@ -1,13 +1,16 @@
-/* 
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+/*
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
 #include <stdlib.h>
+#include <unistd.h>
 #include <errno.h>
+#include <fcntl.h>
+#include "kern_constants.h"
+#include "kern_util.h"
 #include "os.h"
 #include "user.h"
-#include "kern_util.h"
 
 struct grantpt_info {
         int fd;
@@ -26,36 +29,34 @@ static void grantpt_cb(void *arg)
 int get_pty(void)
 {
         struct grantpt_info info;
-        int fd;
-
-        fd = os_open_file("/dev/ptmx", of_rdwr(OPENFLAGS()), 0);
-        if(fd < 0){
-                printk("get_pty : Couldn't open /dev/ptmx - err = %d\n", -fd);
-                return(fd);
+        int fd, err;
+
+        fd = open("/dev/ptmx", O_RDWR);
+        if (fd < 0) {
+                err = -errno;
+                printk(UM_KERN_ERR "get_pty : Couldn't open /dev/ptmx - "
+                       "err = %d\n", errno);
+                return err;
         }
 
         info.fd = fd;
         initial_thread_cb(grantpt_cb, &info);
 
-        if(info.res < 0){
-                printk("get_pty : Couldn't grant pty - errno = %d\n", 
-                       -info.err);
-                return(-1);
+        if (info.res < 0) {
+                err = -info.err;
+                printk(UM_KERN_ERR "get_pty : Couldn't grant pty - "
+                       "errno = %d\n", -info.err);
+                goto out;
         }
-        if(unlockpt(fd) < 0){
-                printk("get_pty : Couldn't unlock pty - errno = %d\n", errno);
-                return(-1);
+
+        if (unlockpt(fd) < 0) {
+                err = -errno;
+                printk(UM_KERN_ERR "get_pty : Couldn't unlock pty - "
+                       "errno = %d\n", errno);
+                goto out;
         }
-        return(fd);
+        return fd;
+out:
+        close(fd);
+        return err;
 }
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/os-Linux/tty_log.c b/arch/um/os-Linux/tty_log.c
index d11a55baa6bd..cc648e6fd3a2 100644
--- a/arch/um/os-Linux/tty_log.c
+++ b/arch/um/os-Linux/tty_log.c
@@ -12,7 +12,6 @@
 #include <sys/time.h>
 #include "init.h"
 #include "user.h"
-#include "kern_util.h"
 #include "os.h"
 
 #define TTY_LOG_DIR "./"
diff --git a/arch/um/os-Linux/util.c b/arch/um/os-Linux/util.c
index 3e058ce9ffb6..a6f31d476993 100644
--- a/arch/um/os-Linux/util.c
+++ b/arch/um/os-Linux/util.c
@@ -88,21 +88,6 @@ void setup_hostinfo(char *buf, int len)
                  host.release, host.version, host.machine);
 }
 
-int setjmp_wrapper(void (*proc)(void *, void *), ...)
-{
-        va_list args;
-        jmp_buf buf;
-        int n;
-
-        n = UML_SETJMP(&buf);
-        if(n == 0){
-                va_start(args, proc);
-                (*proc)(&buf, &args);
-        }
-        va_end(args);
-        return n;
-}
-
 void os_dump_core(void)
 {
         int pid;
diff --git a/arch/um/sys-i386/bug.c b/arch/um/sys-i386/bug.c
index a4360b5207db..8d4f273f1219 100644
--- a/arch/um/sys-i386/bug.c
+++ b/arch/um/sys-i386/bug.c
@@ -4,6 +4,7 @@
  */
 
 #include <linux/uaccess.h>
+#include <asm/errno.h>
 
 /* Mostly copied from i386/x86_86 - eliminated the eip < PAGE_OFFSET because
  * that's not relevant in skas mode.
diff --git a/arch/um/sys-i386/bugs.c b/arch/um/sys-i386/bugs.c
index 806895d73bcc..a74442d13762 100644
--- a/arch/um/sys-i386/bugs.c
+++ b/arch/um/sys-i386/bugs.c
@@ -3,171 +3,47 @@
  * Licensed under the GPL
  */
 
-#include <errno.h>
 #include <signal.h>
-#include <string.h>
 #include "kern_constants.h"
-#include "os.h"
+#include "kern_util.h"
+#include "longjmp.h"
 #include "task.h"
 #include "user.h"
-
-#define MAXTOKEN 64
+#include "sysdep/ptrace.h"
 
 /* Set during early boot */
 int host_has_cmov = 1;
-int host_has_xmm = 0;
+static jmp_buf cmov_test_return;
 
-static char token(int fd, char *buf, int len, char stop)
+static void cmov_sigill_test_handler(int sig)
 {
-        int n;
-        char *ptr, *end, c;
-
-        ptr = buf;
-        end = &buf[len];
-        do {
-                n = os_read_file(fd, ptr, sizeof(*ptr));
-                c = *ptr++;
-                if (n != sizeof(*ptr)) {
-                        if (n == 0)
-                                return 0;
-                        printk(UM_KERN_ERR "Reading /proc/cpuinfo failed, "
-                               "err = %d\n", -n);
-                        if (n < 0)
-                                return n;
-                        else return -EIO;
-                }
-        } while ((c != '\n') && (c != stop) && (ptr < end));
-
-        if (ptr == end) {
-                printk(UM_KERN_ERR "Failed to find '%c' in /proc/cpuinfo\n",
-                       stop);
-                return -1;
-        }
-        *(ptr - 1) = '\0';
-        return c;
-}
-
-static int find_cpuinfo_line(int fd, char *key, char *scratch, int len)
-{
-        int n;
-        char c;
-
-        scratch[len - 1] = '\0';
-        while (1) {
-                c = token(fd, scratch, len - 1, ':');
-                if (c <= 0)
-                        return 0;
-                else if (c != ':') {
-                        printk(UM_KERN_ERR "Failed to find ':' in "
-                               "/proc/cpuinfo\n");
-                        return 0;
-                }
-
-                if (!strncmp(scratch, key, strlen(key)))
-                        return 1;
-
-                do {
-                        n = os_read_file(fd, &c, sizeof(c));
-                        if (n != sizeof(c)) {
-                                printk(UM_KERN_ERR "Failed to find newline in "
-                                       "/proc/cpuinfo, err = %d\n", -n);
-                                return 0;
-                        }
-                } while (c != '\n');
-        }
-        return 0;
+        host_has_cmov = 0;
+        longjmp(cmov_test_return, 1);
 }
 
-static int check_cpu_flag(char *feature, int *have_it)
-{
-        char buf[MAXTOKEN], c;
-        int fd, len = ARRAY_SIZE(buf);
-
-        printk(UM_KERN_INFO "Checking for host processor %s support...",
-               feature);
-        fd = os_open_file("/proc/cpuinfo", of_read(OPENFLAGS()), 0);
-        if (fd < 0) {
-                printk(UM_KERN_ERR "Couldn't open /proc/cpuinfo, err = %d\n",
-                       -fd);
-                return 0;
-        }
-
-        *have_it = 0;
-        if (!find_cpuinfo_line(fd, "flags", buf, ARRAY_SIZE(buf)))
-                goto out;
-
-        c = token(fd, buf, len - 1, ' ');
-        if (c < 0)
-                goto out;
-        else if (c != ' ') {
-                printk(UM_KERN_ERR "Failed to find ' ' in /proc/cpuinfo\n");
-                goto out;
-        }
-
-        while (1) {
-                c = token(fd, buf, len - 1, ' ');
-                if (c < 0)
-                        goto out;
-                else if (c == '\n')
-                        break;
-
-                if (!strcmp(buf, feature)) {
-                        *have_it = 1;
-                        goto out;
-                }
-        }
- out:
-        if (*have_it == 0)
-                printk("No\n");
-        else if (*have_it == 1)
-                printk("Yes\n");
-        os_close_file(fd);
-        return 1;
-}
-
-#if 0 /*
-       * This doesn't work in tt mode, plus it's causing compilation problems
-       * for some people.
-       */
-static void disable_lcall(void)
+void arch_check_bugs(void)
 {
-        struct modify_ldt_ldt_s ldt;
-        int err;
+        struct sigaction old, new;
 
-        bzero(&ldt, sizeof(ldt));
-        ldt.entry_number = 7;
-        ldt.base_addr = 0;
-        ldt.limit = 0;
-        err = modify_ldt(1, &ldt, sizeof(ldt));
-        if (err)
-                printk(UM_KERN_ERR "Failed to disable lcall7 - errno = %d\n",
-                       errno);
-}
-#endif
+        printk(UM_KERN_INFO "Checking for host processor cmov support...");
+        new.sa_handler = cmov_sigill_test_handler;
 
-void arch_init_thread(void)
-{
-#if 0
-        disable_lcall();
-#endif
-}
+        /* Make sure that SIGILL is enabled after the handler longjmps back */
+        new.sa_flags = SA_NODEFER;
+        sigemptyset(&new.sa_mask);
+        sigaction(SIGILL, &new, &old);
 
-void arch_check_bugs(void)
-{
-        int have_it;
+        if (setjmp(cmov_test_return) == 0) {
+                unsigned long foo = 0;
+                __asm__ __volatile__("cmovz %0, %1" : "=r" (foo) : "0" (foo));
+                printk(UM_KERN_CONT "Yes\n");
+        } else
+                printk(UM_KERN_CONT "No\n");
 
-        if (os_access("/proc/cpuinfo", OS_ACC_R_OK) < 0) {
-                printk(UM_KERN_ERR "/proc/cpuinfo not available - skipping CPU "
-                       "capability checks\n");
-                return;
-        }
-        if (check_cpu_flag("cmov", &have_it))
-                host_has_cmov = have_it;
-        if (check_cpu_flag("xmm", &have_it))
-                host_has_xmm = have_it;
+        sigaction(SIGILL, &old, &new);
 }
 
-int arch_handle_signal(int sig, struct uml_pt_regs *regs)
+void arch_examine_signal(int sig, struct uml_pt_regs *regs)
 {
         unsigned char tmp[2];
 
@@ -176,24 +52,25 @@ int arch_handle_signal(int sig, struct uml_pt_regs *regs)
          * SIGILL in init.
          */
         if ((sig != SIGILL) || (TASK_PID(get_current()) != 1))
-                return 0;
+                return;
+
+        if (copy_from_user_proc(tmp, (void *) UPT_IP(regs), 2)) {
+                printk(UM_KERN_ERR "SIGILL in init, could not read "
+                       "instructions!\n");
+                return;
+        }
 
-        if (copy_from_user_proc(tmp, (void *) UPT_IP(regs), 2))
-                panic("SIGILL in init, could not read instructions!\n");
         if ((tmp[0] != 0x0f) || ((tmp[1] & 0xf0) != 0x40))
-                return 0;
+                return;
 
         if (host_has_cmov == 0)
-                panic("SIGILL caused by cmov, which this processor doesn't "
-                      "implement, boot a filesystem compiled for older "
-                      "processors");
+                printk(UM_KERN_ERR "SIGILL caused by cmov, which this "
+                       "processor doesn't implement.  Boot a filesystem "
+                       "compiled for older processors");
         else if (host_has_cmov == 1)
-                panic("SIGILL caused by cmov, which this processor claims to "
-                      "implement");
-        else if (host_has_cmov == -1)
-                panic("SIGILL caused by cmov, couldn't tell if this processor "
-                      "implements it, boot a filesystem compiled for older "
-                      "processors");
-        else panic("Bad value for host_has_cmov (%d)", host_has_cmov);
-        return 0;
+                printk(UM_KERN_ERR "SIGILL caused by cmov, which this "
+                       "processor claims to implement");
+        else
+                printk(UM_KERN_ERR "Bad value for host_has_cmov (%d)",
+                        host_has_cmov);
 }
diff --git a/arch/um/sys-i386/ldt.c b/arch/um/sys-i386/ldt.c
index 67c0958eb984..a34263e6b08d 100644
--- a/arch/um/sys-i386/ldt.c
+++ b/arch/um/sys-i386/ldt.c
@@ -3,8 +3,9 @@
  * Licensed under the GPL
  */
 
-#include "linux/mm.h"
-#include "asm/unistd.h"
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <asm/unistd.h>
 #include "os.h"
 #include "proc_mm.h"
 #include "skas.h"
@@ -146,7 +147,7 @@ static int read_ldt(void __user * ptr, unsigned long bytecount)
         if (ptrace_ldt)
                 return read_ldt_from_host(ptr, bytecount);
 
-        down(&ldt->semaphore);
+        mutex_lock(&ldt->lock);
         if (ldt->entry_count <= LDT_DIRECT_ENTRIES) {
                 size = LDT_ENTRY_SIZE*LDT_DIRECT_ENTRIES;
                 if (size > bytecount)
@@ -170,7 +171,7 @@ static int read_ldt(void __user * ptr, unsigned long bytecount)
                         ptr += size;
                 }
         }
-        up(&ldt->semaphore);
+        mutex_unlock(&ldt->lock);
 
         if (bytecount == 0 || err == -EFAULT)
                 goto out;
@@ -228,7 +229,7 @@ static int write_ldt(void __user * ptr, unsigned long bytecount, int func)
         }
 
         if (!ptrace_ldt)
-                down(&ldt->semaphore);
+                mutex_lock(&ldt->lock);
 
         err = write_ldt_entry(mm_idp, func, &ldt_info, &addr, 1);
         if (err)
@@ -288,7 +289,7 @@ static int write_ldt(void __user * ptr, unsigned long bytecount, int func)
         err = 0;
 
 out_unlock:
-        up(&ldt->semaphore);
+        mutex_unlock(&ldt->lock);
 out:
         return err;
 }
@@ -395,7 +396,7 @@ long init_new_ldt(struct mm_context *new_mm, struct mm_context *from_mm)
 
 
         if (!ptrace_ldt)
-                init_MUTEX(&new_mm->ldt.semaphore);
+                mutex_init(&new_mm->ldt.lock);
 
         if (!from_mm) {
                 memset(&desc, 0, sizeof(desc));
@@ -455,7 +456,7 @@ long init_new_ldt(struct mm_context *new_mm, struct mm_context *from_mm)
                  * i.e., we have to use the stub for modify_ldt, which
                  * can't handle the big read buffer of up to 64kB.
                  */
-                down(&from_mm->ldt.semaphore);
+                mutex_lock(&from_mm->ldt.lock);
                 if (from_mm->ldt.entry_count <= LDT_DIRECT_ENTRIES)
                         memcpy(new_mm->ldt.u.entries, from_mm->ldt.u.entries,
                                sizeof(new_mm->ldt.u.entries));
@@ -474,7 +475,7 @@ long init_new_ldt(struct mm_context *new_mm, struct mm_context *from_mm)
                         }
                 }
                 new_mm->ldt.entry_count = from_mm->ldt.entry_count;
-                up(&from_mm->ldt.semaphore);
+                mutex_unlock(&from_mm->ldt.lock);
         }
 
     out:
diff --git a/arch/um/sys-i386/ptrace.c b/arch/um/sys-i386/ptrace.c
index bd3da8a61f64..6b4499906a6c 100644
--- a/arch/um/sys-i386/ptrace.c
+++ b/arch/um/sys-i386/ptrace.c
@@ -8,11 +8,11 @@
 #include "asm/uaccess.h"
 #include "skas.h"
 
-extern int arch_switch_tls(struct task_struct *from, struct task_struct *to);
+extern int arch_switch_tls(struct task_struct *to);
 
-void arch_switch_to(struct task_struct *from, struct task_struct *to)
+void arch_switch_to(struct task_struct *to)
 {
-        int err = arch_switch_tls(from, to);
+        int err = arch_switch_tls(to);
         if (!err)
                 return;
 
diff --git a/arch/um/sys-i386/ptrace_user.c b/arch/um/sys-i386/ptrace_user.c
index 5cf97bc229b9..0b10c3e74028 100644
--- a/arch/um/sys-i386/ptrace_user.c
+++ b/arch/um/sys-i386/ptrace_user.c
@@ -19,17 +19,3 @@ int ptrace_setregs(long pid, unsigned long *regs)
                 return -errno;
         return 0;
 }
-
-int ptrace_getfpregs(long pid, unsigned long *regs)
-{
-        if (ptrace(PTRACE_GETFPREGS, pid, 0, regs) < 0)
-                return -errno;
-        return 0;
-}
-
-int ptrace_setfpregs(long pid, unsigned long *regs)
-{
-        if (ptrace(PTRACE_SETFPREGS, pid, 0, regs) < 0)
-                return -errno;
-        return 0;
-}
diff --git a/arch/um/sys-i386/signal.c b/arch/um/sys-i386/signal.c
index 19053d46cb60..fd0c25ad6af3 100644
--- a/arch/um/sys-i386/signal.c
+++ b/arch/um/sys-i386/signal.c
@@ -168,12 +168,13 @@ static int copy_sc_from_user(struct pt_regs *regs,
                              struct sigcontext __user *from)
 {
         struct sigcontext sc;
-        int err;
+        int err, pid;
 
         err = copy_from_user(&sc, from, sizeof(sc));
         if (err)
                 return err;
 
+        pid = userspace_pid[current_thread_info()->cpu];
         copy_sc(&regs->regs, &sc);
         if (have_fpx_regs) {
                 struct user_fxsr_struct fpx;
@@ -187,8 +188,7 @@ static int copy_sc_from_user(struct pt_regs *regs,
                 if (err)
                         return 1;
 
-                err = restore_fpx_registers(userspace_pid[current_thread->cpu],
-                                            (unsigned long *) &fpx);
+                err = restore_fpx_registers(pid, (unsigned long *) &fpx);
                 if (err < 0) {
                         printk(KERN_ERR "copy_sc_from_user - "
                                "restore_fpx_registers failed, errno = %d\n",
@@ -204,8 +204,7 @@ static int copy_sc_from_user(struct pt_regs *regs,
                 if (err)
                         return 1;
 
-                err = restore_fp_registers(userspace_pid[current_thread->cpu],
-                                           (unsigned long *) &fp);
+                err = restore_fp_registers(pid, (unsigned long *) &fp);
                 if (err < 0) {
                         printk(KERN_ERR "copy_sc_from_user - "
                                "restore_fp_registers failed, errno = %d\n",
@@ -223,7 +222,7 @@ static int copy_sc_to_user(struct sigcontext __user *to,
 {
         struct sigcontext sc;
         struct faultinfo * fi = &current->thread.arch.faultinfo;
-        int err;
+        int err, pid;
 
         sc.gs = REGS_GS(regs->regs.gp);
         sc.fs = REGS_FS(regs->regs.gp);
@@ -249,11 +248,11 @@ static int copy_sc_to_user(struct sigcontext __user *to,
         to_fp = (to_fp ? to_fp : (struct _fpstate __user *) (to + 1));
         sc.fpstate = to_fp;
 
+        pid = userspace_pid[current_thread_info()->cpu];
         if (have_fpx_regs) {
                 struct user_fxsr_struct fpx;
 
-                err = save_fpx_registers(userspace_pid[current_thread->cpu],
-                                         (unsigned long *) &fpx);
+                err = save_fpx_registers(pid, (unsigned long *) &fpx);
                 if (err < 0){
                         printk(KERN_ERR "copy_sc_to_user - save_fpx_registers "
                                "failed, errno = %d\n", err);
@@ -276,8 +275,7 @@ static int copy_sc_to_user(struct sigcontext __user *to,
         else {
                 struct user_i387_struct fp;
 
-                err = save_fp_registers(userspace_pid[current_thread->cpu],
-                                        (unsigned long *) &fp);
+                err = save_fp_registers(pid, (unsigned long *) &fp);
                 if (copy_to_user(to_fp, &fp, sizeof(struct user_i387_struct)))
                         return 1;
         }
diff --git a/arch/um/sys-i386/stub.S b/arch/um/sys-i386/stub.S
index e730772c401b..7699e89f660f 100644
--- a/arch/um/sys-i386/stub.S
+++ b/arch/um/sys-i386/stub.S
@@ -7,7 +7,7 @@
         .globl batch_syscall_stub
 batch_syscall_stub:
         /* load pointer to first operation */
-        mov     $(ASM_STUB_DATA+8), %esp
+        mov     $(STUB_DATA+8), %esp
 
 again:
         /* load length of additional data */
@@ -15,12 +15,12 @@ again:
 
         /* if(length == 0) : end of list */
         /* write possible 0 to header */
-        mov     %eax, ASM_STUB_DATA+4
+        mov     %eax, STUB_DATA+4
         cmpl    $0, %eax
         jz      done
 
         /* save current pointer */
-        mov     %esp, ASM_STUB_DATA+4
+        mov     %esp, STUB_DATA+4
 
         /* skip additional data */
         add     %eax, %esp
@@ -46,7 +46,7 @@ again:
 
 done:
         /* save return value */
-        mov     %eax, ASM_STUB_DATA
+        mov     %eax, STUB_DATA
 
         /* stop */
         int3
diff --git a/arch/um/sys-i386/stub_segv.c b/arch/um/sys-i386/stub_segv.c
index b3999cb76bfd..28ccf737a79f 100644
--- a/arch/um/sys-i386/stub_segv.c
+++ b/arch/um/sys-i386/stub_segv.c
@@ -1,32 +1,17 @@
 /*
- * Copyright (C) 2004 Jeff Dike (jdike@addtoit.com)
+ * Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
-#include <signal.h>
-#include <sys/select.h> /* The only way I can see to get sigset_t */
-#include <asm/unistd.h>
-#include "as-layout.h"
-#include "uml-config.h"
 #include "sysdep/stub.h"
 #include "sysdep/sigcontext.h"
-#include "sysdep/faultinfo.h"
 
 void __attribute__ ((__section__ (".__syscall_stub")))
 stub_segv_handler(int sig)
 {
         struct sigcontext *sc = (struct sigcontext *) (&sig + 1);
-        int pid;
 
         GET_FAULTINFO_FROM_SC(*((struct faultinfo *) STUB_DATA), sc);
 
-        pid = stub_syscall0(__NR_getpid);
-        stub_syscall2(__NR_kill, pid, SIGUSR1);
-
-        /* Load pointer to sigcontext into esp, since we need to leave
-         * the stack in its original form when we do the sigreturn here, by
-         * hand.
-         */
-        __asm__ __volatile__("mov %0,%%esp ; movl %1, %%eax ; "
-                             "int $0x80" : : "a" (sc), "g" (__NR_sigreturn));
+        trap_myself();
 }
diff --git a/arch/um/sys-i386/sys_call_table.S b/arch/um/sys-i386/sys_call_table.S
index 12d4148dba39..00e5f5203eea 100644
--- a/arch/um/sys-i386/sys_call_table.S
+++ b/arch/um/sys-i386/sys_call_table.S
@@ -9,4 +9,9 @@
 
 #define old_mmap old_mmap_i386
 
+.section .rodata,"a"
+
 #include "../../x86/kernel/syscall_table_32.S"
+
+ENTRY(syscall_table_size)
+.long .-sys_call_table
diff --git a/arch/um/sys-i386/tls.c b/arch/um/sys-i386/tls.c
index fcaff86b000c..c6c7131e563b 100644
--- a/arch/um/sys-i386/tls.c
+++ b/arch/um/sys-i386/tls.c
@@ -26,6 +26,11 @@ int do_set_thread_area(struct user_desc *info)
         cpu = get_cpu();
         ret = os_set_thread_area(info, userspace_pid[cpu]);
         put_cpu();
+
+        if (ret)
+                printk(KERN_ERR "PTRACE_SET_THREAD_AREA failed, err = %d, "
+                       "index = %d\n", ret, info->entry_number);
+
         return ret;
 }
 
@@ -37,6 +42,11 @@ int do_get_thread_area(struct user_desc *info)
         cpu = get_cpu();
         ret = os_get_thread_area(info, userspace_pid[cpu]);
         put_cpu();
+
+        if (ret)
+                printk(KERN_ERR "PTRACE_GET_THREAD_AREA failed, err = %d, "
+                       "index = %d\n", ret, info->entry_number);
+
         return ret;
 }
 
@@ -172,7 +182,7 @@ void clear_flushed_tls(struct task_struct *task)
  * SKAS patch.
  */
 
-int arch_switch_tls(struct task_struct *from, struct task_struct *to)
+int arch_switch_tls(struct task_struct *to)
 {
         if (!host_supports_tls)
                 return 0;
@@ -225,7 +235,8 @@ out:
 }
 
 /* XXX: use do_get_thread_area to read the host value? I'm not at all sure! */
-static int get_tls_entry(struct task_struct* task, struct user_desc *info, int idx)
+static int get_tls_entry(struct task_struct *task, struct user_desc *info,
+                         int idx)
 {
         struct thread_struct *t = &task->thread;
 
@@ -263,7 +274,7 @@ clear:
         goto out;
 }
 
-asmlinkage int sys_set_thread_area(struct user_desc __user *user_desc)
+int sys_set_thread_area(struct user_desc __user *user_desc)
 {
         struct user_desc info;
         int idx, ret;
@@ -298,7 +309,7 @@ asmlinkage int sys_set_thread_area(struct user_desc __user *user_desc)
  * i386. However the only possible error are caused by bugs.
  */
 int ptrace_set_thread_area(struct task_struct *child, int idx,
-                struct user_desc __user *user_desc)
+                           struct user_desc __user *user_desc)
 {
         struct user_desc info;
 
@@ -311,7 +322,7 @@ int ptrace_set_thread_area(struct task_struct *child, int idx,
         return set_tls_entry(child, &info, idx, 0);
 }
 
-asmlinkage int sys_get_thread_area(struct user_desc __user *user_desc)
+int sys_get_thread_area(struct user_desc __user *user_desc)
 {
         struct user_desc info;
         int idx, ret;
@@ -355,10 +366,9 @@ out:
         return ret;
 }
 
-
 /*
- * XXX: This part is probably common to i386 and x86-64. Don't create a common
- * file for now, do that when implementing x86-64 support.
+ * This code is really i386-only, but it detects and logs x86_64 GDT indexes
+ * if a 32-bit UML is running on a 64-bit host.
  */
 static int __init __setup_host_supports_tls(void)
 {
@@ -367,13 +377,16 @@ static int __init __setup_host_supports_tls(void)
                 printk(KERN_INFO "Host TLS support detected\n");
                 printk(KERN_INFO "Detected host type: ");
                 switch (host_gdt_entry_tls_min) {
-                        case GDT_ENTRY_TLS_MIN_I386:
-                                printk("i386\n");
-                                break;
-                        case GDT_ENTRY_TLS_MIN_X86_64:
-                                printk("x86_64\n");
-                                break;
+                case GDT_ENTRY_TLS_MIN_I386:
+                        printk(KERN_CONT "i386");
+                        break;
+                case GDT_ENTRY_TLS_MIN_X86_64:
+                        printk(KERN_CONT "x86_64");
+                        break;
                 }
+                printk(KERN_CONT " (GDT indexes %d to %d)\n",
+                       host_gdt_entry_tls_min,
+                       host_gdt_entry_tls_min + GDT_ENTRY_TLS_ENTRIES);
         } else
                 printk(KERN_ERR "  Host TLS support NOT detected! "
                                 "TLS support inside UML will not work\n");
diff --git a/arch/um/sys-ppc/Makefile b/arch/um/sys-ppc/Makefile
index a9814a7ae60e..08901526e893 100644
--- a/arch/um/sys-ppc/Makefile
+++ b/arch/um/sys-ppc/Makefile
@@ -6,7 +6,7 @@ OBJ = built-in.o
 OBJS = ptrace.o sigcontext.o semaphore.o checksum.o miscthings.o misc.o \
         ptrace_user.o sysrq.o
 
-EXTRA_AFLAGS := -DCONFIG_PPC32 -I. -I$(TOPDIR)/arch/ppc/kernel
+EXTRA_AFLAGS := -DCONFIG_PPC32 -I. -I$(srctree)/arch/ppc/kernel
 
 all: $(OBJ)
 
@@ -22,25 +22,25 @@ sigcontext.o: sigcontext.c
 
 semaphore.c:
         rm -f $@
-        ln -s $(TOPDIR)/arch/ppc/kernel/$@ $@
+        ln -s $(srctree)/arch/ppc/kernel/$@ $@
 
 checksum.S:
         rm -f $@
-        ln -s $(TOPDIR)/arch/ppc/lib/$@ $@
+        ln -s $(srctree)/arch/ppc/lib/$@ $@
 
 mk_defs.c:
         rm -f $@
-        ln -s $(TOPDIR)/arch/ppc/kernel/$@ $@
+        ln -s $(srctree)/arch/ppc/kernel/$@ $@
 
 ppc_defs.head:
         rm -f $@
-        ln -s $(TOPDIR)/arch/ppc/kernel/$@ $@
+        ln -s $(srctree)/arch/ppc/kernel/$@ $@
 
 ppc_defs.h: mk_defs.c ppc_defs.head \
-                $(TOPDIR)/include/asm-ppc/mmu.h \
-                $(TOPDIR)/include/asm-ppc/processor.h \
-                $(TOPDIR)/include/asm-ppc/pgtable.h \
-                $(TOPDIR)/include/asm-ppc/ptrace.h
+                $(srctree)/include/asm-ppc/mmu.h \
+                $(srctree)/include/asm-ppc/processor.h \
+                $(srctree)/include/asm-ppc/pgtable.h \
+                $(srctree)/include/asm-ppc/ptrace.h
 #       $(CC) $(CFLAGS) -S mk_defs.c
         cp ppc_defs.head ppc_defs.h
 # for bk, this way we can write to the file even if it's not checked out
@@ -56,13 +56,13 @@ ppc_defs.h: mk_defs.c ppc_defs.head \
 
 checksum.o: checksum.S
         rm -f asm
-        ln -s $(TOPDIR)/include/asm-ppc asm
+        ln -s $(srctree)/include/asm-ppc asm
         $(CC) $(EXTRA_AFLAGS) $(KBUILD_AFLAGS) -D__ASSEMBLY__ -D__UM_PPC__ -c $< -o $*.o
         rm -f asm
 
 misc.o: misc.S ppc_defs.h
         rm -f asm
-        ln -s $(TOPDIR)/include/asm-ppc asm
+        ln -s $(srctree)/include/asm-ppc asm
         $(CC) $(EXTRA_AFLAGS) $(KBUILD_AFLAGS) -D__ASSEMBLY__ -D__UM_PPC__ -c $< -o $*.o
         rm -f asm
 
diff --git a/arch/um/sys-x86_64/bug.c b/arch/um/sys-x86_64/bug.c
index a4360b5207db..e8034e363d83 100644
--- a/arch/um/sys-x86_64/bug.c
+++ b/arch/um/sys-x86_64/bug.c
@@ -5,7 +5,8 @@
 
 #include <linux/uaccess.h>
 
-/* Mostly copied from i386/x86_86 - eliminated the eip < PAGE_OFFSET because
+/*
+ * Mostly copied from i386/x86_86 - eliminated the eip < PAGE_OFFSET because
  * that's not relevant in skas mode.
  */
 
diff --git a/arch/um/sys-x86_64/bugs.c b/arch/um/sys-x86_64/bugs.c
index 506b6765bbcb..44e02ba2a265 100644
--- a/arch/um/sys-x86_64/bugs.c
+++ b/arch/um/sys-x86_64/bugs.c
@@ -6,15 +6,10 @@
 
 #include "sysdep/ptrace.h"
 
-void arch_init_thread(void)
-{
-}
-
 void arch_check_bugs(void)
 {
 }
 
-int arch_handle_signal(int sig, struct uml_pt_regs *regs)
+void arch_examine_signal(int sig, struct uml_pt_regs *regs)
 {
-        return 0;
 }
diff --git a/arch/um/sys-x86_64/ptrace.c b/arch/um/sys-x86_64/ptrace.c
index b7631b0e9ddc..f3458d7d1c5a 100644
--- a/arch/um/sys-x86_64/ptrace.c
+++ b/arch/um/sys-x86_64/ptrace.c
@@ -5,13 +5,12 @@
  * Licensed under the GPL
  */
 
-#define __FRAME_OFFSETS
-#include <asm/ptrace.h>
+#include <linux/mm.h>
 #include <linux/sched.h>
 #include <linux/errno.h>
-#include <linux/mm.h>
+#define __FRAME_OFFSETS
+#include <asm/ptrace.h>
 #include <asm/uaccess.h>
-#include <asm/elf.h>
 
 /*
  * determines which flags the user has access to.
@@ -24,12 +23,14 @@ int putreg(struct task_struct *child, int regno, unsigned long value)
         unsigned long tmp;
 
 #ifdef TIF_IA32
-        /* Some code in the 64bit emulation may not be 64bit clean.
-           Don't take any chances. */
+        /*
+         * Some code in the 64bit emulation may not be 64bit clean.
+         * Don't take any chances.
+         */
         if (test_tsk_thread_flag(child, TIF_IA32))
                 value &= 0xffffffff;
 #endif
-        switch (regno){
+        switch (regno) {
         case FS:
         case GS:
         case DS:
@@ -66,7 +67,7 @@ int poke_user(struct task_struct *child, long addr, long data)
         if (addr < MAX_REG_OFFSET)
                 return putreg(child, addr, data);
         else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
-                (addr <= offsetof(struct user, u_debugreg[7]))){
+                (addr <= offsetof(struct user, u_debugreg[7]))) {
                 addr -= offsetof(struct user, u_debugreg[0]);
                 addr = addr >> 2;
                 if ((addr == 4) || (addr == 5))
@@ -108,11 +109,10 @@ int peek_user(struct task_struct *child, long addr, long data)
                 return -EIO;
 
         tmp = 0;  /* Default return condition */
-        if (addr < MAX_REG_OFFSET){
+        if (addr < MAX_REG_OFFSET)
                 tmp = getreg(child, addr);
-        }
         else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
-                (addr <= offsetof(struct user, u_debugreg[7]))){
+                (addr <= offsetof(struct user, u_debugreg[7]))) {
                 addr -= offsetof(struct user, u_debugreg[0]);
                 addr = addr >> 2;
                 tmp = child->thread.arch.debugregs[addr];
@@ -127,8 +127,9 @@ int is_syscall(unsigned long addr)
         int n;
 
         n = copy_from_user(&instr, (void __user *) addr, sizeof(instr));
-        if (n){
-                /* access_process_vm() grants access to vsyscall and stub,
+        if (n) {
+                /*
+                 * access_process_vm() grants access to vsyscall and stub,
                  * while copy_from_user doesn't. Maybe access_process_vm is
                  * slow, but that doesn't matter, since it will be called only
                  * in case of singlestepping, if copy_from_user failed.
@@ -155,7 +156,7 @@ int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
                 return err;
 
         n = copy_to_user(buf, fpregs, sizeof(fpregs));
-        if(n > 0)
+        if (n > 0)
                 return -EFAULT;
 
         return n;
diff --git a/arch/um/sys-x86_64/ptrace_user.c b/arch/um/sys-x86_64/ptrace_user.c
index b5f9c33e311e..c57a496d3f5b 100644
--- a/arch/um/sys-x86_64/ptrace_user.c
+++ b/arch/um/sys-x86_64/ptrace_user.c
@@ -4,55 +4,19 @@
  * Licensed under the GPL
  */
 
-#include <stddef.h>
 #include <errno.h>
 #include "ptrace_user.h"
-#include "user.h"
-#include "kern_constants.h"
 
 int ptrace_getregs(long pid, unsigned long *regs_out)
 {
-        if(ptrace(PTRACE_GETREGS, pid, 0, regs_out) < 0)
-                return(-errno);
-        return(0);
-}
-
-int ptrace_setregs(long pid, unsigned long *regs)
-{
-        if(ptrace(PTRACE_SETREGS, pid, 0, regs) < 0)
-                return(-errno);
+        if (ptrace(PTRACE_GETREGS, pid, 0, regs_out) < 0)
+                return -errno;
         return(0);
 }
 
-int ptrace_setfpregs(long pid, unsigned long *regs)
+int ptrace_setregs(long pid, unsigned long *regs_out)
 {
-        if (ptrace(PTRACE_SETFPREGS, pid, 0, regs) < 0)
+        if (ptrace(PTRACE_SETREGS, pid, 0, regs_out) < 0)
                 return -errno;
-        return 0;
-}
-
-void ptrace_pokeuser(unsigned long addr, unsigned long data)
-{
-        panic("ptrace_pokeuser");
-}
-
-#define DS 184
-#define ES 192
-#define __USER_DS     0x2b
-
-void arch_enter_kernel(void *task, int pid)
-{
-}
-
-void arch_leave_kernel(void *task, int pid)
-{
-#ifdef UM_USER_CS
-        if(ptrace(PTRACE_POKEUSR, pid, CS, UM_USER_CS) < 0)
-                printk("POKEUSR CS failed");
-#endif
-
-        if(ptrace(PTRACE_POKEUSR, pid, DS, __USER_DS) < 0)
-                printk("POKEUSR DS failed");
-        if(ptrace(PTRACE_POKEUSR, pid, ES, __USER_DS) < 0)
-                printk("POKEUSR ES failed");
+        return(0);
 }
diff --git a/arch/um/sys-x86_64/signal.c b/arch/um/sys-x86_64/signal.c
index 14070181407b..1a899a7ed7a6 100644
--- a/arch/um/sys-x86_64/signal.c
+++ b/arch/um/sys-x86_64/signal.c
@@ -81,7 +81,7 @@ static int copy_sc_from_user(struct pt_regs *regs,
         if (err)
                 return 1;
 
-        err = restore_fp_registers(userspace_pid[current_thread->cpu],
+        err = restore_fp_registers(userspace_pid[current_thread_info()->cpu],
                                    (unsigned long *) &fp);
         if (err < 0) {
                 printk(KERN_ERR "copy_sc_from_user - "
@@ -143,7 +143,7 @@ static int copy_sc_to_user(struct sigcontext __user *to,
         if (err)
                 return 1;
 
-        err = save_fp_registers(userspace_pid[current_thread->cpu],
+        err = save_fp_registers(userspace_pid[current_thread_info()->cpu],
                                 (unsigned long *) &fp);
         if (err < 0) {
                 printk(KERN_ERR "copy_sc_from_user - restore_fp_registers "
diff --git a/arch/um/sys-x86_64/stub.S b/arch/um/sys-x86_64/stub.S
index 4afe204a6af7..568768763155 100644
--- a/arch/um/sys-x86_64/stub.S
+++ b/arch/um/sys-x86_64/stub.S
@@ -8,18 +8,18 @@ syscall_stub:
         /* We don't have 64-bit constants, so this constructs the address
          * we need.
          */
-        movq    $(ASM_STUB_DATA >> 32), %rbx
+        movq    $(STUB_DATA >> 32), %rbx
         salq    $32, %rbx
-        movq    $(ASM_STUB_DATA & 0xffffffff), %rcx
+        movq    $(STUB_DATA & 0xffffffff), %rcx
         or      %rcx, %rbx
         movq    %rax, (%rbx)
         int3
 
         .globl batch_syscall_stub
 batch_syscall_stub:
-        mov     $(ASM_STUB_DATA >> 32), %rbx
+        mov     $(STUB_DATA >> 32), %rbx
         sal     $32, %rbx
-        mov     $(ASM_STUB_DATA & 0xffffffff), %rax
+        mov     $(STUB_DATA & 0xffffffff), %rax
         or      %rax, %rbx
         /* load pointer to first operation */
         mov     %rbx, %rsp
diff --git a/arch/um/sys-x86_64/stub_segv.c b/arch/um/sys-x86_64/stub_segv.c
index 3afb590f0072..ced051afc705 100644
--- a/arch/um/sys-x86_64/stub_segv.c
+++ b/arch/um/sys-x86_64/stub_segv.c
@@ -1,51 +1,22 @@
 /*
- * Copyright (C) 2004 Jeff Dike (jdike@addtoit.com)
+ * Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
-#include <stddef.h>
 #include <signal.h>
-#include <asm/unistd.h>
 #include "as-layout.h"
-#include "uml-config.h"
-#include "sysdep/sigcontext.h"
-#include "sysdep/faultinfo.h"
 #include "sysdep/stub.h"
-
-/* Copied from sys-x86_64/signal.c - Can't find an equivalent definition
- * in the libc headers anywhere.
- */
-struct rt_sigframe
-{
-        char *pretcode;
-        struct ucontext uc;
-        struct siginfo info;
-};
-
-/* Copied here from <linux/kernel.h> - we're userspace. */
-#define container_of(ptr, type, member) ({                   \
-        const typeof( ((type *)0)->member ) *__mptr = (ptr); \
-        (type *)( (char *)__mptr - offsetof(type,member) );})
+#include "sysdep/faultinfo.h"
+#include "sysdep/sigcontext.h"
 
 void __attribute__ ((__section__ (".__syscall_stub")))
 stub_segv_handler(int sig)
 {
         struct ucontext *uc;
-        int pid;
 
         __asm__ __volatile__("movq %%rdx, %0" : "=g" (uc) :);
         GET_FAULTINFO_FROM_SC(*((struct faultinfo *) STUB_DATA),
                               &uc->uc_mcontext);
-
-        pid = stub_syscall0(__NR_getpid);
-        stub_syscall2(__NR_kill, pid, SIGUSR1);
-
-        /* sys_sigreturn expects that the stack pointer will be 8 bytes into
-         * the signal frame.  So, we use the ucontext pointer, which we know
-         * already, to get the signal frame pointer, and add 8 to that.
-         */
-        __asm__ __volatile__("movq %0, %%rsp; movq %1, %%rax ; syscall": :
-                             "g" ((unsigned long)
-                                  container_of(uc, struct rt_sigframe, uc) + 8),
-                             "g" (__NR_rt_sigreturn));
+        trap_myself();
 }
+
diff --git a/arch/um/sys-x86_64/syscall_table.c b/arch/um/sys-x86_64/syscall_table.c
index 71b2ae4ad5de..c128eb897008 100644
--- a/arch/um/sys-x86_64/syscall_table.c
+++ b/arch/um/sys-x86_64/syscall_table.c
@@ -1,5 +1,7 @@
-/* System call table for UML/x86-64, copied from arch/x86_64/kernel/syscall.c
- * with some changes for UML. */
+/*
+ * System call table for UML/x86-64, copied from arch/x86_64/kernel/syscall.c
+ * with some changes for UML.
+ */
 
 #include <linux/linkage.h>
 #include <linux/sys.h>
@@ -8,22 +10,26 @@
 
 #define __NO_STUBS
 
-/* Below you can see, in terms of #define's, the differences between the x86-64
- * and the UML syscall table. */
+/*
+ * Below you can see, in terms of #define's, the differences between the x86-64
+ * and the UML syscall table.
+ */
 
 /* Not going to be implemented by UML, since we have no hardware. */
 #define stub_iopl sys_ni_syscall
 #define sys_ioperm sys_ni_syscall
 
-/* The UML TLS problem. Note that x86_64 does not implement this, so the below
- * is needed only for the ia32 compatibility. */
-/*#define sys_set_thread_area sys_ni_syscall
-#define sys_get_thread_area sys_ni_syscall*/
+/*
+ * The UML TLS problem. Note that x86_64 does not implement this, so the below
+ * is needed only for the ia32 compatibility.
+ */
 
 /* On UML we call it this way ("old" means it's not mmap2) */
 #define sys_mmap old_mmap
-/* On x86-64 sys_uname is actually sys_newuname plus a compatibility trick.
- * See arch/x86_64/kernel/sys_x86_64.c */
+/*
+ * On x86-64 sys_uname is actually sys_newuname plus a compatibility trick.
+ * See arch/x86_64/kernel/sys_x86_64.c
+ */
 #define sys_uname sys_uname64
 
 #define stub_clone sys_clone
@@ -46,8 +52,19 @@ typedef void (*sys_call_ptr_t)(void);
 
 extern void sys_ni_syscall(void);
 
-sys_call_ptr_t sys_call_table[UM_NR_syscall_max+1] __cacheline_aligned = {
-        /* Smells like a like a compiler bug -- it doesn't work when the & below is removed. */
-        [0 ... UM_NR_syscall_max] = &sys_ni_syscall,
+/*
+ * We used to have a trick here which made sure that holes in the
+ * x86_64 table were filled in with sys_ni_syscall, but a comment in
+ * unistd_64.h says that holes aren't allowed, so the trick was
+ * removed.
+ * The trick looked like this
+ *      [0 ... UM_NR_syscall_max] = &sys_ni_syscall
+ * before including unistd_64.h - the later initializations overwrote
+ * the sys_ni_syscall filler.
+ */
+
+sys_call_ptr_t sys_call_table[] __cacheline_aligned = {
 #include <asm-x86/unistd_64.h>
 };
+
+int syscall_table_size = sizeof(sys_call_table);
diff --git a/arch/um/sys-x86_64/syscalls.c b/arch/um/sys-x86_64/syscalls.c
index 86f6b18410ee..f1199fd34d38 100644
--- a/arch/um/sys-x86_64/syscalls.c
+++ b/arch/um/sys-x86_64/syscalls.c
@@ -48,7 +48,9 @@ long arch_prctl(struct task_struct *task, int code, unsigned long __user *addr)
         switch (code) {
         case ARCH_SET_FS:
         case ARCH_SET_GS:
-                restore_registers(pid, &current->thread.regs.regs);
+                ret = restore_registers(pid, &current->thread.regs.regs);
+                if (ret)
+                        return ret;
                 break;
         case ARCH_GET_FS:
         case ARCH_GET_GS:
@@ -70,10 +72,10 @@ long arch_prctl(struct task_struct *task, int code, unsigned long __user *addr)
         switch (code) {
         case ARCH_SET_FS:
                 current->thread.arch.fs = (unsigned long) ptr;
-                save_registers(pid, &current->thread.regs.regs);
+                ret = save_registers(pid, &current->thread.regs.regs);
                 break;
         case ARCH_SET_GS:
-                save_registers(pid, &current->thread.regs.regs);
+                ret = save_registers(pid, &current->thread.regs.regs);
                 break;
         case ARCH_GET_FS:
                 ret = put_user(tmp, addr);
@@ -105,7 +107,7 @@ long sys_clone(unsigned long clone_flags, unsigned long newsp,
         return ret;
 }
 
-void arch_switch_to(struct task_struct *from, struct task_struct *to)
+void arch_switch_to(struct task_struct *to)
 {
         if ((to->thread.arch.fs == 0) || (to->mm == NULL))
                 return;
diff --git a/arch/um/sys-x86_64/sysrq.c b/arch/um/sys-x86_64/sysrq.c
index 765444031819..f4f82beb3508 100644
--- a/arch/um/sys-x86_64/sysrq.c
+++ b/arch/um/sys-x86_64/sysrq.c
@@ -4,32 +4,33 @@
  * Licensed under the GPL
  */
 
-#include "linux/kernel.h"
-#include "linux/utsname.h"
-#include "linux/module.h"
-#include "asm/current.h"
-#include "asm/ptrace.h"
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/utsname.h>
+#include <asm/current.h>
+#include <asm/ptrace.h>
 #include "sysrq.h"
 
-void __show_regs(struct pt_regs * regs)
+void __show_regs(struct pt_regs *regs)
 {
         printk("\n");
         print_modules();
-        printk("Pid: %d, comm: %.20s %s %s\n", task_pid_nr(current),
+        printk(KERN_INFO "Pid: %d, comm: %.20s %s %s\n", task_pid_nr(current),
                 current->comm, print_tainted(), init_utsname()->release);
-        printk("RIP: %04lx:[<%016lx>] ", PT_REGS_CS(regs) & 0xffff,
+        printk(KERN_INFO "RIP: %04lx:[<%016lx>]\n", PT_REGS_CS(regs) & 0xffff,
                PT_REGS_RIP(regs));
-        printk("\nRSP: %016lx  EFLAGS: %08lx\n", PT_REGS_RSP(regs),
+        printk(KERN_INFO "RSP: %016lx  EFLAGS: %08lx\n", PT_REGS_RSP(regs),
                PT_REGS_EFLAGS(regs));
-        printk("RAX: %016lx RBX: %016lx RCX: %016lx\n",
+        printk(KERN_INFO "RAX: %016lx RBX: %016lx RCX: %016lx\n",
                PT_REGS_RAX(regs), PT_REGS_RBX(regs), PT_REGS_RCX(regs));
-        printk("RDX: %016lx RSI: %016lx RDI: %016lx\n",
+        printk(KERN_INFO "RDX: %016lx RSI: %016lx RDI: %016lx\n",
                PT_REGS_RDX(regs), PT_REGS_RSI(regs), PT_REGS_RDI(regs));
-        printk("RBP: %016lx R08: %016lx R09: %016lx\n",
+        printk(KERN_INFO "RBP: %016lx R08: %016lx R09: %016lx\n",
                PT_REGS_RBP(regs), PT_REGS_R8(regs), PT_REGS_R9(regs));
-        printk("R10: %016lx R11: %016lx R12: %016lx\n",
+        printk(KERN_INFO "R10: %016lx R11: %016lx R12: %016lx\n",
                PT_REGS_R10(regs), PT_REGS_R11(regs), PT_REGS_R12(regs));
-        printk("R13: %016lx R14: %016lx R15: %016lx\n",
+        printk(KERN_INFO "R13: %016lx R14: %016lx R15: %016lx\n",
                PT_REGS_R13(regs), PT_REGS_R14(regs), PT_REGS_R15(regs));
 }
 
diff --git a/arch/um/sys-x86_64/um_module.c b/arch/um/sys-x86_64/um_module.c
index 8b8eff1bd977..3dead392a415 100644
--- a/arch/um/sys-x86_64/um_module.c
+++ b/arch/um/sys-x86_64/um_module.c
@@ -1,7 +1,7 @@
 #include <linux/vmalloc.h>
 #include <linux/moduleloader.h>
 
-/*Copied from i386 arch/i386/kernel/module.c */
+/* Copied from i386 arch/i386/kernel/module.c */
 void *module_alloc(unsigned long size)
 {
         if (size == 0)
@@ -13,7 +13,9 @@ void *module_alloc(unsigned long size)
 void module_free(struct module *mod, void *module_region)
 {
         vfree(module_region);
-        /* FIXME: If module_region == mod->init_region, trim exception
-           table entries. */
+        /*
+         * FIXME: If module_region == mod->init_region, trim exception
+         * table entries.
+         */
 }