13 files changed, 676 insertions, 223 deletions

diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile
index a2d93065b2d0..6fa63a2a89e3 100644
--- a/arch/um/kernel/Makefile
+++ b/arch/um/kernel/Makefile
@@ -7,7 +7,7 @@ extra-y := vmlinux.lds
 clean-files :=
 
 obj-y = config.o exec.o exitcode.o init_task.o irq.o ksyms.o mem.o \
-        physmem.o process_kern.o ptrace.o reboot.o resource.o sigio.o \
+        physmem.o process.o ptrace.o reboot.o resource.o sigio.o \
         signal.o smp.o syscall.o sysrq.o time.o tlb.o trap.o uaccess.o \
         um_arch.o umid.o
 
diff --git a/arch/um/kernel/gmon_syms.c b/arch/um/kernel/gmon_syms.c
index 2c86e7fdb014..13aa115cd1b4 100644
--- a/arch/um/kernel/gmon_syms.c
+++ b/arch/um/kernel/gmon_syms.c
@@ -5,7 +5,7 @@
 
 #include "linux/module.h"
 
-extern void __bb_init_func(void *);
+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
@@ -21,14 +21,3 @@ EXPORT_SYMBOL(__gcov_init);
 
 extern void __gcov_merge_add(void *) __attribute__((weak));
 EXPORT_SYMBOL(__gcov_merge_add);
-
-/*
- * 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/ksyms.c b/arch/um/kernel/ksyms.c
index c97045d6d89f..f030e44262ba 100644
--- a/arch/um/kernel/ksyms.c
+++ b/arch/um/kernel/ksyms.c
@@ -21,7 +21,6 @@
 #include "mem_user.h"
 #include "os.h"
 
-EXPORT_SYMBOL(stop);
 EXPORT_SYMBOL(uml_physmem);
 EXPORT_SYMBOL(set_signals);
 EXPORT_SYMBOL(get_signals);
@@ -41,12 +40,14 @@ EXPORT_SYMBOL(handle_page_fault);
 EXPORT_SYMBOL(find_iomem);
 
 #ifdef CONFIG_MODE_TT
+EXPORT_SYMBOL(stop);
 EXPORT_SYMBOL(strncpy_from_user_tt);
 EXPORT_SYMBOL(copy_from_user_tt);
 EXPORT_SYMBOL(copy_to_user_tt);
 #endif
 
 #ifdef CONFIG_MODE_SKAS
+EXPORT_SYMBOL(strnlen_user_skas);
 EXPORT_SYMBOL(strncpy_from_user_skas);
 EXPORT_SYMBOL(copy_to_user_skas);
 EXPORT_SYMBOL(copy_from_user_skas);
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index 93121c6d26e5..c95855ba6ab5 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -226,7 +226,8 @@ void paging_init(void)
         for(i = 0; i < ARRAY_SIZE(zones_size); i++)
                 zones_size[i] = 0;
 
-        zones_size[ZONE_DMA] = (end_iomem >> PAGE_SHIFT) - (uml_physmem >> PAGE_SHIFT);
+        zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) -
+                (uml_physmem >> PAGE_SHIFT);
 #ifdef CONFIG_HIGHMEM
         zones_size[ZONE_HIGHMEM] = highmem >> PAGE_SHIFT;
 #endif
diff --git a/arch/um/kernel/process_kern.c b/arch/um/kernel/process.c
index 537895d68ad1..fe6c64abda5b 100644
--- a/arch/um/kernel/process_kern.c
+++ b/arch/um/kernel/process.c
@@ -1,10 +1,9 @@
-/* 
+/*
  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
  * Copyright 2003 PathScale, Inc.
  * Licensed under the GPL
  */
 
-#include "linux/config.h"
 #include "linux/kernel.h"
 #include "linux/sched.h"
 #include "linux/interrupt.h"
@@ -113,11 +112,11 @@ void set_current(void *t)
 
 void *_switch_to(void *prev, void *next, void *last)
 {
-        struct task_struct *from = prev;
-        struct task_struct *to= next;
+        struct task_struct *from = prev;
+        struct task_struct *to= next;
 
-        to->thread.prev_sched = from;
-        set_current(to);
+        to->thread.prev_sched = from;
+        set_current(to);
 
         do {
                 current->thread.saved_task = NULL ;
@@ -128,7 +127,7 @@ void *_switch_to(void *prev, void *next, void *last)
                 prev= current;
         } while(current->thread.saved_task);
 
-        return(current->thread.prev_sched);
+        return(current->thread.prev_sched);
 
 }
 
@@ -142,19 +141,19 @@ void release_thread(struct task_struct *task)
 {
         CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
 }
- 
+
 void exit_thread(void)
 {
         unprotect_stack((unsigned long) current_thread);
 }
- 
+
 void *get_current(void)
 {
         return(current);
 }
 
 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
-                unsigned long stack_top, struct task_struct * p, 
+                unsigned long stack_top, struct task_struct * p,
                 struct pt_regs *regs)
 {
         int ret;
@@ -183,11 +182,11 @@ void initial_thread_cb(void (*proc)(void *), void *arg)
         int save_kmalloc_ok = kmalloc_ok;
 
         kmalloc_ok = 0;
-        CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc, 
+        CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc,
                          arg);
         kmalloc_ok = save_kmalloc_ok;
 }
- 
+
 unsigned long stack_sp(unsigned long page)
 {
         return(page + PAGE_SIZE - sizeof(void *));
@@ -211,7 +210,7 @@ void default_idle(void)
                  */
                 if(need_resched())
                         schedule();
-                
+
                 idle_sleep(10);
         }
 }
@@ -226,7 +225,7 @@ int page_size(void)
         return(PAGE_SIZE);
 }
 
-void *um_virt_to_phys(struct task_struct *task, unsigned long addr, 
+void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
                       pte_t *pte_out)
 {
         pgd_t *pgd;
@@ -235,7 +234,7 @@ void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
         pte_t *pte;
         pte_t ptent;
 
-        if(task->mm == NULL) 
+        if(task->mm == NULL)
                 return(ERR_PTR(-EINVAL));
         pgd = pgd_offset(task->mm, addr);
         if(!pgd_present(*pgd))
@@ -246,7 +245,7 @@ void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
                 return(ERR_PTR(-EINVAL));
 
         pmd = pmd_offset(pud, addr);
-        if(!pmd_present(*pmd)) 
+        if(!pmd_present(*pmd))
                 return(ERR_PTR(-EINVAL));
 
         pte = pte_offset_kernel(pmd, addr);
@@ -271,7 +270,7 @@ char *current_cmd(void)
 
 void force_sigbus(void)
 {
-        printk(KERN_ERR "Killing pid %d because of a lack of memory\n", 
+        printk(KERN_ERR "Killing pid %d because of a lack of memory\n",
                current->pid);
         lock_kernel();
         sigaddset(&current->pending.signal, SIGBUS);
diff --git a/arch/um/kernel/skas/Makefile b/arch/um/kernel/skas/Makefile
index ea3a8e409a6e..3e3fa7e7e3cf 100644
--- a/arch/um/kernel/skas/Makefile
+++ b/arch/um/kernel/skas/Makefile
@@ -3,8 +3,7 @@
 # Licensed under the GPL
 #
 
-obj-y := clone.o exec_kern.o mem.o mmu.o process_kern.o \
-        syscall.o tlb.o uaccess.o
+obj-y := clone.o exec.o mem.o mmu.o process.o syscall.o tlb.o uaccess.o
 
 # clone.o is in the stub, so it can't be built with profiling
 # GCC hardened also auto-enables -fpic, but we need %ebx so it can't work ->
diff --git a/arch/um/kernel/skas/exec.c b/arch/um/kernel/skas/exec.c
new file mode 100644
index 000000000000..54b795951372
--- /dev/null
+++ b/arch/um/kernel/skas/exec.c
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include "linux/kernel.h"
+#include "asm/current.h"
+#include "asm/page.h"
+#include "asm/signal.h"
+#include "asm/ptrace.h"
+#include "asm/uaccess.h"
+#include "asm/mmu_context.h"
+#include "tlb.h"
+#include "skas.h"
+#include "um_mmu.h"
+#include "os.h"
+
+void flush_thread_skas(void)
+{
+        force_flush_all();
+        switch_mm_skas(&current->mm->context.skas.id);
+}
+
+void start_thread_skas(struct pt_regs *regs, unsigned long eip,
+                       unsigned long esp)
+{
+        set_fs(USER_DS);
+        PT_REGS_IP(regs) = eip;
+        PT_REGS_SP(regs) = esp;
+}
diff --git a/arch/um/kernel/skas/exec_kern.c b/arch/um/kernel/skas/exec_kern.c
deleted file mode 100644
index 77ed7bbab219..000000000000
--- a/arch/um/kernel/skas/exec_kern.c
+++ /dev/null
@@ -1,41 +0,0 @@
-/* 
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#include "linux/kernel.h"
-#include "asm/current.h"
-#include "asm/page.h"
-#include "asm/signal.h"
-#include "asm/ptrace.h"
-#include "asm/uaccess.h"
-#include "asm/mmu_context.h"
-#include "tlb.h"
-#include "skas.h"
-#include "um_mmu.h"
-#include "os.h"
-
-void flush_thread_skas(void)
-{
-        force_flush_all();
-        switch_mm_skas(&current->mm->context.skas.id);
-}
-
-void start_thread_skas(struct pt_regs *regs, unsigned long eip, 
-                       unsigned long esp)
-{
-        set_fs(USER_DS);
-        PT_REGS_IP(regs) = eip;
-        PT_REGS_SP(regs) = esp;
-}
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/kernel/skas/process.c b/arch/um/kernel/skas/process.c
new file mode 100644
index 000000000000..ae4fa71d3b8b
--- /dev/null
+++ b/arch/um/kernel/skas/process.c
@@ -0,0 +1,217 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include "linux/sched.h"
+#include "linux/slab.h"
+#include "linux/ptrace.h"
+#include "linux/proc_fs.h"
+#include "linux/file.h"
+#include "linux/errno.h"
+#include "linux/init.h"
+#include "asm/uaccess.h"
+#include "asm/atomic.h"
+#include "kern_util.h"
+#include "skas.h"
+#include "os.h"
+#include "user_util.h"
+#include "tlb.h"
+#include "kern.h"
+#include "mode.h"
+#include "registers.h"
+
+void switch_to_skas(void *prev, void *next)
+{
+        struct task_struct *from, *to;
+
+        from = prev;
+        to = next;
+
+        /* XXX need to check runqueues[cpu].idle */
+        if(current->pid == 0)
+                switch_timers(0);
+
+        switch_threads(&from->thread.mode.skas.switch_buf,
+                       &to->thread.mode.skas.switch_buf);
+
+        arch_switch_to_skas(current->thread.prev_sched, current);
+
+        if(current->pid == 0)
+                switch_timers(1);
+}
+
+extern void schedule_tail(struct task_struct *prev);
+
+/* This is called magically, by its address being stuffed in a jmp_buf
+ * and being longjmp-d to.
+ */
+void new_thread_handler(void)
+{
+        int (*fn)(void *), n;
+        void *arg;
+
+        if(current->thread.prev_sched != NULL)
+                schedule_tail(current->thread.prev_sched);
+        current->thread.prev_sched = NULL;
+
+        fn = current->thread.request.u.thread.proc;
+        arg = current->thread.request.u.thread.arg;
+
+        /* The return value is 1 if the kernel thread execs a process,
+         * 0 if it just exits
+         */
+        n = run_kernel_thread(fn, arg, &current->thread.exec_buf);
+        if(n == 1){
+                /* Handle any immediate reschedules or signals */
+                interrupt_end();
+                userspace(&current->thread.regs.regs);
+        }
+        else do_exit(0);
+}
+
+void release_thread_skas(struct task_struct *task)
+{
+}
+
+/* Called magically, see new_thread_handler above */
+void fork_handler(void)
+{
+        force_flush_all();
+        if(current->thread.prev_sched == NULL)
+                panic("blech");
+
+        schedule_tail(current->thread.prev_sched);
+
+        /* XXX: if interrupt_end() calls schedule, this call to
+         * arch_switch_to_skas isn't needed. We could want to apply this to
+         * improve performance. -bb */
+        arch_switch_to_skas(current->thread.prev_sched, current);
+
+        current->thread.prev_sched = NULL;
+
+/* Handle any immediate reschedules or signals */
+        interrupt_end();
+
+        userspace(&current->thread.regs.regs);
+}
+
+int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp,
+                     unsigned long stack_top, struct task_struct * p,
+                     struct pt_regs *regs)
+{
+        void (*handler)(void);
+
+        if(current->thread.forking){
+                memcpy(&p->thread.regs.regs.skas, &regs->regs.skas,
+                       sizeof(p->thread.regs.regs.skas));
+                REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.skas.regs, 0);
+                if(sp != 0) REGS_SP(p->thread.regs.regs.skas.regs) = sp;
+
+                handler = fork_handler;
+
+                arch_copy_thread(&current->thread.arch, &p->thread.arch);
+        }
+        else {
+                init_thread_registers(&p->thread.regs.regs);
+                p->thread.request.u.thread = current->thread.request.u.thread;
+                handler = new_thread_handler;
+        }
+
+        new_thread(task_stack_page(p), &p->thread.mode.skas.switch_buf,
+                   handler);
+        return(0);
+}
+
+int new_mm(unsigned long stack)
+{
+        int fd;
+
+        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, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack);
+
+        return(fd);
+}
+
+void init_idle_skas(void)
+{
+        cpu_tasks[current_thread->cpu].pid = os_getpid();
+        default_idle();
+}
+
+extern void start_kernel(void);
+
+static int start_kernel_proc(void *unused)
+{
+        int pid;
+
+        block_signals();
+        pid = os_getpid();
+
+        cpu_tasks[0].pid = pid;
+        cpu_tasks[0].task = current;
+#ifdef CONFIG_SMP
+        cpu_online_map = cpumask_of_cpu(0);
+#endif
+        start_kernel();
+        return(0);
+}
+
+extern int userspace_pid[];
+
+int start_uml_skas(void)
+{
+        if(proc_mm)
+                userspace_pid[0] = start_userspace(0);
+
+        init_new_thread_signals();
+
+        init_task.thread.request.u.thread.proc = start_kernel_proc;
+        init_task.thread.request.u.thread.arg = NULL;
+        return(start_idle_thread(task_stack_page(&init_task),
+                                 &init_task.thread.mode.skas.switch_buf));
+}
+
+int external_pid_skas(struct task_struct *task)
+{
+#warning Need to look up userspace_pid by cpu
+        return(userspace_pid[0]);
+}
+
+int thread_pid_skas(struct task_struct *task)
+{
+#warning Need to look up userspace_pid by cpu
+        return(userspace_pid[0]);
+}
+
+void kill_off_processes_skas(void)
+{
+        if(proc_mm)
+#warning need to loop over userspace_pids in kill_off_processes_skas
+                os_kill_ptraced_process(userspace_pid[0], 1);
+        else {
+                struct task_struct *p;
+                int pid, me;
+
+                me = os_getpid();
+                for_each_process(p){
+                        if(p->mm == NULL)
+                                continue;
+
+                        pid = p->mm->context.skas.id.u.pid;
+                        os_kill_ptraced_process(pid, 1);
+                }
+        }
+}
+
+unsigned long current_stub_stack(void)
+{
+        if(current->mm == NULL)
+                return(0);
+
+        return(current->mm->context.skas.id.stack);
+}
diff --git a/arch/um/kernel/skas/process_kern.c b/arch/um/kernel/skas/process_kern.c
index 55caeec8b257..0f3d5d084dc7 100644
--- a/arch/um/kernel/skas/process_kern.c
+++ b/arch/um/kernel/skas/process_kern.c
@@ -1,227 +1,484 @@
 /*
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright 2003 PathScale, Inc.
  * Licensed under the GPL
  */
 
+#include "linux/config.h"
+#include "linux/kernel.h"
 #include "linux/sched.h"
+#include "linux/interrupt.h"
+#include "linux/string.h"
+#include "linux/mm.h"
 #include "linux/slab.h"
-#include "linux/ptrace.h"
-#include "linux/proc_fs.h"
-#include "linux/file.h"
-#include "linux/errno.h"
+#include "linux/utsname.h"
+#include "linux/fs.h"
+#include "linux/utime.h"
+#include "linux/smp_lock.h"
+#include "linux/module.h"
 #include "linux/init.h"
+#include "linux/capability.h"
+#include "linux/vmalloc.h"
+#include "linux/spinlock.h"
+#include "linux/proc_fs.h"
+#include "linux/ptrace.h"
+#include "linux/random.h"
+#include "linux/personality.h"
+#include "asm/unistd.h"
+#include "asm/mman.h"
+#include "asm/segment.h"
+#include "asm/stat.h"
+#include "asm/pgtable.h"
+#include "asm/processor.h"
+#include "asm/tlbflush.h"
 #include "asm/uaccess.h"
-#include "asm/atomic.h"
-#include "kern_util.h"
-#include "skas.h"
-#include "os.h"
+#include "asm/user.h"
 #include "user_util.h"
-#include "tlb.h"
+#include "kern_util.h"
 #include "kern.h"
+#include "signal_kern.h"
+#include "init.h"
+#include "irq_user.h"
+#include "mem_user.h"
+#include "tlb.h"
+#include "frame_kern.h"
+#include "sigcontext.h"
+#include "os.h"
 #include "mode.h"
-#include "registers.h"
+#include "mode_kern.h"
+#include "choose-mode.h"
+
+/* This is a per-cpu array.  A processor only modifies its entry and it only
+ * cares about its entry, so it's OK if another processor is modifying its
+ * entry.
+ */
+struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
+
+int external_pid(void *t)
+{
+        struct task_struct *task = t ? t : current;
+
+        return(CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task));
+}
+
+int pid_to_processor_id(int pid)
+{
+        int i;
+
+        for(i = 0; i < ncpus; i++){
+                if(cpu_tasks[i].pid == pid) return(i);
+        }
+        return(-1);
+}
+
+void free_stack(unsigned long stack, int order)
+{
+        free_pages(stack, order);
+}
+
+unsigned long alloc_stack(int order, int atomic)
+{
+        unsigned long page;
+        gfp_t flags = GFP_KERNEL;
+
+        if (atomic)
+                flags = GFP_ATOMIC;
+        page = __get_free_pages(flags, order);
+        if(page == 0)
+                return(0);
+        stack_protections(page);
+        return(page);
+}
+
+int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
+{
+        int pid;
+
+        current->thread.request.u.thread.proc = fn;
+        current->thread.request.u.thread.arg = arg;
+        pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0,
+                      &current->thread.regs, 0, NULL, NULL);
+        if(pid < 0)
+                panic("do_fork failed in kernel_thread, errno = %d", pid);
+        return(pid);
+}
 
-void switch_to_skas(void *prev, void *next)
+void set_current(void *t)
 {
-        struct task_struct *from, *to;
+        struct task_struct *task = t;
 
-        from = prev;
-        to = next;
+        cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
+                { external_pid(task), task });
+}
 
-        /* XXX need to check runqueues[cpu].idle */
-        if(current->pid == 0)
-                switch_timers(0);
+void *_switch_to(void *prev, void *next, void *last)
+{
+        struct task_struct *from = prev;
+        struct task_struct *to= next;
 
-        switch_threads(&from->thread.mode.skas.switch_buf,
-                       to->thread.mode.skas.switch_buf);
+        to->thread.prev_sched = from;
+        set_current(to);
 
-        arch_switch_to_skas(current->thread.prev_sched, current);
+        do {
+                current->thread.saved_task = NULL ;
+                CHOOSE_MODE_PROC(switch_to_tt, switch_to_skas, prev, next);
+                if(current->thread.saved_task)
+                        show_regs(&(current->thread.regs));
+                next= current->thread.saved_task;
+                prev= current;
+        } while(current->thread.saved_task);
+
+        return(current->thread.prev_sched);
 
-        if(current->pid == 0)
-                switch_timers(1);
 }
 
-extern void schedule_tail(struct task_struct *prev);
+void interrupt_end(void)
+{
+        if(need_resched()) schedule();
+        if(test_tsk_thread_flag(current, TIF_SIGPENDING)) do_signal();
+}
 
-void new_thread_handler(int sig)
+void release_thread(struct task_struct *task)
 {
-        int (*fn)(void *), n;
-        void *arg;
+        CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
+}
 
-        fn = current->thread.request.u.thread.proc;
-        arg = current->thread.request.u.thread.arg;
-        os_usr1_signal(1);
-        thread_wait(&current->thread.mode.skas.switch_buf,
-                    current->thread.mode.skas.fork_buf);
+void exit_thread(void)
+{
+        unprotect_stack((unsigned long) current_thread);
+}
 
-        if(current->thread.prev_sched != NULL)
-                schedule_tail(current->thread.prev_sched);
-        current->thread.prev_sched = NULL;
+void *get_current(void)
+{
+        return(current);
+}
+
+int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
+                unsigned long stack_top, struct task_struct * p,
+                struct pt_regs *regs)
+{
+        int ret;
 
-        /* The return value is 1 if the kernel thread execs a process,
-         * 0 if it just exits
+        p->thread = (struct thread_struct) INIT_THREAD;
+        ret = CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr,
+                                clone_flags, sp, stack_top, p, regs);
+
+        if (ret || !current->thread.forking)
+                goto out;
+
+        clear_flushed_tls(p);
+
+        /*
+         * Set a new TLS for the child thread?
          */
-        n = run_kernel_thread(fn, arg, &current->thread.exec_buf);
-        if(n == 1){
-                /* Handle any immediate reschedules or signals */
-                interrupt_end();
-                userspace(&current->thread.regs.regs);
+        if (clone_flags & CLONE_SETTLS)
+                ret = arch_copy_tls(p);
+
+out:
+        return ret;
+}
+
+void initial_thread_cb(void (*proc)(void *), void *arg)
+{
+        int save_kmalloc_ok = kmalloc_ok;
+
+        kmalloc_ok = 0;
+        CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc,
+                         arg);
+        kmalloc_ok = save_kmalloc_ok;
+}
+
+unsigned long stack_sp(unsigned long page)
+{
+        return(page + PAGE_SIZE - sizeof(void *));
+}
+
+int current_pid(void)
+{
+        return(current->pid);
+}
+
+void default_idle(void)
+{
+        CHOOSE_MODE(uml_idle_timer(), (void) 0);
+
+        while(1){
+                /* endless idle loop with no priority at all */
+
+                /*
+                 * although we are an idle CPU, we do not want to
+                 * get into the scheduler unnecessarily.
+                 */
+                if(need_resched())
+                        schedule();
+
+                idle_sleep(10);
         }
-        else do_exit(0);
 }
 
-void new_thread_proc(void *stack, void (*handler)(int sig))
+void cpu_idle(void)
 {
-        init_new_thread_stack(stack, handler);
-        os_usr1_process(os_getpid());
+        CHOOSE_MODE(init_idle_tt(), init_idle_skas());
 }
 
-void release_thread_skas(struct task_struct *task)
+int page_size(void)
 {
+        return(PAGE_SIZE);
 }
 
-void fork_handler(int sig)
+void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
+                      pte_t *pte_out)
 {
-        os_usr1_signal(1);
-        thread_wait(&current->thread.mode.skas.switch_buf,
-                    current->thread.mode.skas.fork_buf);
-        
-        force_flush_all();
-        if(current->thread.prev_sched == NULL)
-                panic("blech");
+        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));
+}
 
-        schedule_tail(current->thread.prev_sched);
+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
+}
 
-        /* XXX: if interrupt_end() calls schedule, this call to
-         * arch_switch_to_skas isn't needed. We could want to apply this to
-         * improve performance. -bb */
-        arch_switch_to_skas(current->thread.prev_sched, current);
+void force_sigbus(void)
+{
+        printk(KERN_ERR "Killing pid %d because of a lack of memory\n",
+               current->pid);
+        lock_kernel();
+        sigaddset(&current->pending.signal, SIGBUS);
+        recalc_sigpending();
+        current->flags |= PF_SIGNALED;
+        do_exit(SIGBUS | 0x80);
+}
 
-        current->thread.prev_sched = NULL;
+void dump_thread(struct pt_regs *regs, struct user *u)
+{
+}
 
-/* Handle any immediate reschedules or signals */
-        interrupt_end();
+void enable_hlt(void)
+{
+        panic("enable_hlt");
+}
+
+EXPORT_SYMBOL(enable_hlt);
 
-        userspace(&current->thread.regs.regs);
+void disable_hlt(void)
+{
+        panic("disable_hlt");
 }
 
-int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp,
-                     unsigned long stack_top, struct task_struct * p,
-                     struct pt_regs *regs)
+EXPORT_SYMBOL(disable_hlt);
+
+void *um_kmalloc(int size)
 {
-        void (*handler)(int);
+        return kmalloc(size, GFP_KERNEL);
+}
 
-        if(current->thread.forking){
-                memcpy(&p->thread.regs.regs.skas, &regs->regs.skas,
-                       sizeof(p->thread.regs.regs.skas));
-                REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.skas.regs, 0);
-                if(sp != 0) REGS_SP(p->thread.regs.regs.skas.regs) = sp;
+void *um_kmalloc_atomic(int size)
+{
+        return kmalloc(size, GFP_ATOMIC);
+}
 
-                handler = fork_handler;
+void *um_vmalloc(int size)
+{
+        return vmalloc(size);
+}
 
-                arch_copy_thread(&current->thread.arch, &p->thread.arch);
-        }
-        else {
-                init_thread_registers(&p->thread.regs.regs);
-                p->thread.request.u.thread = current->thread.request.u.thread;
-                handler = new_thread_handler;
-        }
+void *um_vmalloc_atomic(int size)
+{
+        return __vmalloc(size, GFP_ATOMIC | __GFP_HIGHMEM, PAGE_KERNEL);
+}
 
-        new_thread(task_stack_page(p), &p->thread.mode.skas.switch_buf,
-                   &p->thread.mode.skas.fork_buf, handler);
-        return(0);
+int __cant_sleep(void) {
+        return in_atomic() || irqs_disabled() || in_interrupt();
+        /* Is in_interrupt() really needed? */
+}
+
+unsigned long get_fault_addr(void)
+{
+        return((unsigned long) current->thread.fault_addr);
 }
 
-int new_mm(unsigned long stack)
+EXPORT_SYMBOL(get_fault_addr);
+
+void not_implemented(void)
 {
-        int fd;
+        printk(KERN_DEBUG "Something isn't implemented in here\n");
+}
 
-        fd = os_open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0);
-        if(fd < 0)
-                return(fd);
+EXPORT_SYMBOL(not_implemented);
 
-        if(skas_needs_stub)
-                map_stub_pages(fd, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack);
+int user_context(unsigned long sp)
+{
+        unsigned long stack;
 
-        return(fd);
+        stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
+        return(stack != (unsigned long) current_thread);
 }
 
-void init_idle_skas(void)
+extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
+
+void do_uml_exitcalls(void)
 {
-        cpu_tasks[current_thread->cpu].pid = os_getpid();
-        default_idle();
+        exitcall_t *call;
+
+        call = &__uml_exitcall_end;
+        while (--call >= &__uml_exitcall_begin)
+                (*call)();
 }
 
-extern void start_kernel(void);
+char *uml_strdup(char *string)
+{
+        return kstrdup(string, GFP_KERNEL);
+}
 
-static int start_kernel_proc(void *unused)
+int copy_to_user_proc(void __user *to, void *from, int size)
 {
-        int pid;
+        return(copy_to_user(to, from, size));
+}
+
+int copy_from_user_proc(void *to, void __user *from, int size)
+{
+        return(copy_from_user(to, from, size));
+}
+
+int clear_user_proc(void __user *buf, int size)
+{
+        return(clear_user(buf, size));
+}
 
-        block_signals();
-        pid = os_getpid();
+int strlen_user_proc(char __user *str)
+{
+        return(strlen_user(str));
+}
 
-        cpu_tasks[0].pid = pid;
-        cpu_tasks[0].task = current;
+int smp_sigio_handler(void)
+{
 #ifdef CONFIG_SMP
-        cpu_online_map = cpumask_of_cpu(0);
+        int cpu = current_thread->cpu;
+        IPI_handler(cpu);
+        if(cpu != 0)
+                return(1);
 #endif
-        start_kernel();
         return(0);
 }
 
-extern int userspace_pid[];
-
-int start_uml_skas(void)
+int cpu(void)
 {
-        if(proc_mm)
-                userspace_pid[0] = start_userspace(0);
+        return(current_thread->cpu);
+}
+
+static atomic_t using_sysemu = ATOMIC_INIT(0);
+int sysemu_supported;
 
-        init_new_thread_signals();
+void set_using_sysemu(int value)
+{
+        if (value > sysemu_supported)
+                return;
+        atomic_set(&using_sysemu, value);
+}
 
-        init_task.thread.request.u.thread.proc = start_kernel_proc;
-        init_task.thread.request.u.thread.arg = NULL;
-        return(start_idle_thread(task_stack_page(&init_task),
-                                 &init_task.thread.mode.skas.switch_buf,
-                                 &init_task.thread.mode.skas.fork_buf));
+int get_using_sysemu(void)
+{
+        return atomic_read(&using_sysemu);
 }
 
-int external_pid_skas(struct task_struct *task)
+static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
 {
-#warning Need to look up userspace_pid by cpu
-        return(userspace_pid[0]);
+        if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
+                *eof = 1;
+
+        return strlen(buf);
 }
 
-int thread_pid_skas(struct task_struct *task)
+static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned long count,void *data)
 {
-#warning Need to look up userspace_pid by cpu
-        return(userspace_pid[0]);
+        char tmp[2];
+
+        if (copy_from_user(tmp, buf, 1))
+                return -EFAULT;
+
+        if (tmp[0] >= '0' && tmp[0] <= '2')
+                set_using_sysemu(tmp[0] - '0');
+        return count; /*We use the first char, but pretend to write everything*/
 }
 
-void kill_off_processes_skas(void)
+int __init make_proc_sysemu(void)
 {
-        if(proc_mm)
-#warning need to loop over userspace_pids in kill_off_processes_skas
-                os_kill_ptraced_process(userspace_pid[0], 1);
-        else {
-                struct task_struct *p;
-                int pid, me;
+        struct proc_dir_entry *ent;
+        if (!sysemu_supported)
+                return 0;
 
-                me = os_getpid();
-                for_each_process(p){
-                        if(p->mm == NULL)
-                                continue;
+        ent = create_proc_entry("sysemu", 0600, &proc_root);
 
-                        pid = p->mm->context.skas.id.u.pid;
-                        os_kill_ptraced_process(pid, 1);
-                }
+        if (ent == NULL)
+        {
+                printk(KERN_WARNING "Failed to register /proc/sysemu\n");
+                return(0);
         }
+
+        ent->read_proc  = proc_read_sysemu;
+        ent->write_proc = proc_write_sysemu;
+
+        return 0;
 }
 
-unsigned long current_stub_stack(void)
+late_initcall(make_proc_sysemu);
+
+int singlestepping(void * t)
 {
-        if(current->mm == NULL)
+        struct task_struct *task = t ? t : current;
+
+        if ( ! (task->ptrace & PT_DTRACE) )
                 return(0);
 
-        return(current->mm->context.skas.id.stack);
+        if (task->thread.singlestep_syscall)
+                return(1);
+
+        return 2;
+}
+
+/*
+ * Only x86 and x86_64 have an arch_align_stack().
+ * All other arches have "#define arch_align_stack(x) (x)"
+ * in their asm/system.h
+ * As this is included in UML from asm-um/system-generic.h,
+ * we can use it to behave as the subarch does.
+ */
+#ifndef arch_align_stack
+unsigned long arch_align_stack(unsigned long sp)
+{
+        if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
+                sp -= get_random_int() % 8192;
+        return sp & ~0xf;
 }
+#endif
diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c
index 2454bbd9555d..820affbf3e16 100644
--- a/arch/um/kernel/time.c
+++ b/arch/um/kernel/time.c
@@ -95,7 +95,7 @@ irqreturn_t um_timer(int irq, void *dev, struct pt_regs *regs)
 
         do_timer(regs);
 
-        nsecs = get_time() + local_offset;
+        nsecs = get_time();
         xtime.tv_sec = nsecs / NSEC_PER_SEC;
         xtime.tv_nsec = nsecs - xtime.tv_sec * NSEC_PER_SEC;
 
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index e5eeaf2b6af1..61a23fff4395 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -140,14 +140,6 @@ void segv_handler(int sig, union uml_pt_regs *regs)
         segv(*fi, UPT_IP(regs), UPT_IS_USER(regs), regs);
 }
 
-struct kern_handlers handlinfo_kern = {
-        .relay_signal = relay_signal,
-        .winch = winch,
-        .bus_handler = relay_signal,
-        .page_fault = segv_handler,
-        .sigio_handler = sigio_handler,
-        .timer_handler = timer_handler
-};
 /*
  * We give a *copy* of the faultinfo in the regs to segv.
  * This must be done, since nesting SEGVs could overwrite
@@ -253,6 +245,15 @@ void winch(int sig, union 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/um_arch.c b/arch/um/kernel/um_arch.c
index 7896cf98232d..55005710dcbb 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -106,7 +106,7 @@ static void c_stop(struct seq_file *m, void *v)
 {
 }
 
-struct seq_operations cpuinfo_op = {
+const struct seq_operations cpuinfo_op = {
         .start  = c_start,
         .next   = c_next,
         .stop   = c_stop,