Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee13...
[pandora-kernel.git] / arch / um / kernel / skas / process.c
index 3b3955d..ae4fa71 100644 (file)
-/* 
- * Copyright (C) 2002- 2004 Jeff Dike (jdike@addtoit.com)
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
  */
 
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <errno.h>
-#include <signal.h>
-#include <setjmp.h>
-#include <sched.h>
-#include <sys/wait.h>
-#include <sys/mman.h>
-#include <sys/user.h>
-#include <sys/time.h>
-#include <asm/unistd.h>
-#include <asm/types.h>
-#include "user.h"
-#include "ptrace_user.h"
-#include "time_user.h"
-#include "sysdep/ptrace.h"
-#include "user_util.h"
+#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 "stub-data.h"
-#include "mm_id.h"
-#include "sysdep/sigcontext.h"
-#include "sysdep/stub.h"
 #include "os.h"
-#include "proc_mm.h"
-#include "skas_ptrace.h"
-#include "chan_user.h"
+#include "user_util.h"
+#include "tlb.h"
+#include "kern.h"
+#include "mode.h"
 #include "registers.h"
-#include "mem.h"
-#include "uml-config.h"
-#include "process.h"
 
-int is_skas_winch(int pid, int fd, void *data)
+void switch_to_skas(void *prev, void *next)
 {
-        if(pid != os_getpgrp())
-               return(0);
+       struct task_struct *from, *to;
 
-       register_winch_irq(-1, fd, -1, data);
-       return(1);
-}
+       from = prev;
+       to = next;
 
-void wait_stub_done(int pid, int sig, char * fname)
-{
-        int n, status, err;
-
-        do {
-                if ( sig != -1 ) {
-                        err = ptrace(PTRACE_CONT, pid, 0, sig);
-                        if(err)
-                                panic("%s : continue failed, errno = %d\n",
-                                      fname, errno);
-                }
-                sig = 0;
-
-                CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
-        } while((n >= 0) && WIFSTOPPED(status) &&
-                ((WSTOPSIG(status) == SIGVTALRM) ||
-                /* running UML inside a detached screen can cause
-                 * SIGWINCHes
-                 */
-                (WSTOPSIG(status) == SIGWINCH)));
-
-        if((n < 0) || !WIFSTOPPED(status) ||
-           (WSTOPSIG(status) != SIGUSR1 && WSTOPSIG(status) != SIGTRAP)){
-               unsigned long regs[HOST_FRAME_SIZE];
-               if(ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
-                       printk("Failed to get registers from stub, "
-                              "errno = %d\n", errno);
-               else {
-                       int i;
-
-                       printk("Stub registers -\n");
-                       for(i = 0; i < HOST_FRAME_SIZE; i++)
-                               printk("\t%d - %lx\n", i, regs[i]);
-               }
-                panic("%s : failed to wait for SIGUSR1/SIGTRAP, "
-                      "pid = %d, n = %d, errno = %d, status = 0x%x\n",
-                      fname, pid, n, errno, status);
-        }
-}
+       /* XXX need to check runqueues[cpu].idle */
+       if(current->pid == 0)
+               switch_timers(0);
 
-void get_skas_faultinfo(int pid, struct faultinfo * fi)
-{
-        int err;
-
-        if(ptrace_faultinfo){
-                err = ptrace(PTRACE_FAULTINFO, pid, 0, fi);
-                if(err)
-                        panic("get_skas_faultinfo - PTRACE_FAULTINFO failed, "
-                              "errno = %d\n", errno);
-
-                /* Special handling for i386, which has different structs */
-                if (sizeof(struct ptrace_faultinfo) < sizeof(struct faultinfo))
-                        memset((char *)fi + sizeof(struct ptrace_faultinfo), 0,
-                               sizeof(struct faultinfo) -
-                               sizeof(struct ptrace_faultinfo));
-        }
-        else {
-                wait_stub_done(pid, SIGSEGV, "get_skas_faultinfo");
-
-                /* faultinfo is prepared by the stub-segv-handler at start of
-                 * the stub stack page. We just have to copy it.
-                 */
-                memcpy(fi, (void *)current_stub_stack(), sizeof(*fi));
-        }
-}
-
-static void handle_segv(int pid, union uml_pt_regs * regs)
-{
-        get_skas_faultinfo(pid, &regs->skas.faultinfo);
-        segv(regs->skas.faultinfo, 0, 1, NULL);
-}
+       switch_threads(&from->thread.mode.skas.switch_buf,
+                      &to->thread.mode.skas.switch_buf);
 
-/*To use the same value of using_sysemu as the caller, ask it that value (in local_using_sysemu)*/
-static void handle_trap(int pid, union uml_pt_regs *regs, int local_using_sysemu)
-{
-       int err, status;
-
-       /* Mark this as a syscall */
-       UPT_SYSCALL_NR(regs) = PT_SYSCALL_NR(regs->skas.regs);
-
-       if (!local_using_sysemu)
-       {
-               err = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET, __NR_getpid);
-               if(err < 0)
-                       panic("handle_trap - nullifying syscall failed errno = %d\n",
-                             errno);
-
-               err = ptrace(PTRACE_SYSCALL, pid, 0, 0);
-               if(err < 0)
-                       panic("handle_trap - continuing to end of syscall failed, "
-                             "errno = %d\n", errno);
-
-               CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
-               if((err < 0) || !WIFSTOPPED(status) ||
-                  (WSTOPSIG(status) != SIGTRAP + 0x80))
-                       panic("handle_trap - failed to wait at end of syscall, "
-                             "errno = %d, status = %d\n", errno, status);
-       }
+       arch_switch_to_skas(current->thread.prev_sched, current);
 
-       handle_syscall(regs);
+       if(current->pid == 0)
+               switch_timers(1);
 }
 
-extern int __syscall_stub_start;
-int stub_code_fd = -1;
-__u64 stub_code_offset;
+extern void schedule_tail(struct task_struct *prev);
 
-static int userspace_tramp(void *stack)
+/* This is called magically, by its address being stuffed in a jmp_buf
+ * and being longjmp-d to.
+ */
+void new_thread_handler(void)
 {
-       void *addr;
-
-       ptrace(PTRACE_TRACEME, 0, 0, 0);
-
-       init_new_thread_signals(1);
-       enable_timer();
-
-       if(!proc_mm){
-               /* This has a pte, but it can't be mapped in with the usual
-                * tlb_flush mechanism because this is part of that mechanism
-                */
-               addr = mmap64((void *) UML_CONFIG_STUB_CODE, page_size(),
-                             PROT_EXEC, MAP_FIXED | MAP_PRIVATE,
-                             stub_code_fd, stub_code_offset);
-               if(addr == MAP_FAILED){
-                       printk("mapping stub code failed, errno = %d\n",
-                              errno);
-                       exit(1);
-               }
+       int (*fn)(void *), n;
+       void *arg;
 
-               if(stack != NULL){
-                       int fd;
-                       __u64 offset;
-
-                       fd = phys_mapping(to_phys(stack), &offset);
-                       addr = mmap((void *) UML_CONFIG_STUB_DATA, page_size(),
-                                   PROT_READ | PROT_WRITE,
-                                   MAP_FIXED | MAP_SHARED, fd, offset);
-                       if(addr == MAP_FAILED){
-                               printk("mapping stub stack failed, "
-                                      "errno = %d\n", errno);
-                               exit(1);
-                       }
-               }
-       }
-       if(!ptrace_faultinfo){
-               unsigned long v = UML_CONFIG_STUB_CODE +
-                                 (unsigned long) stub_segv_handler -
-                                 (unsigned long) &__syscall_stub_start;
-
-               set_sigstack((void *) UML_CONFIG_STUB_DATA, page_size());
-               set_handler(SIGSEGV, (void *) v, SA_ONSTACK,
-                           SIGIO, SIGWINCH, SIGALRM, SIGVTALRM,
-                           SIGUSR1, -1);
-       }
-
-       os_stop_process(os_getpid());
-       return(0);
-}
+       if(current->thread.prev_sched != NULL)
+               schedule_tail(current->thread.prev_sched);
+       current->thread.prev_sched = NULL;
 
-/* Each element set once, and only accessed by a single processor anyway */
-#undef NR_CPUS
-#define NR_CPUS 1
-int userspace_pid[NR_CPUS];
+       fn = current->thread.request.u.thread.proc;
+       arg = current->thread.request.u.thread.arg;
 
-int start_userspace(unsigned long stub_stack)
-{
-       void *stack;
-       unsigned long sp;
-       int pid, status, n, flags;
-
-       if ( stub_code_fd == -1 )
-               stub_code_fd = phys_mapping(to_phys(&__syscall_stub_start),
-                                           &stub_code_offset);
-
-       stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
-                    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-       if(stack == MAP_FAILED)
-               panic("start_userspace : mmap failed, errno = %d", errno);
-       sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
-
-       flags = CLONE_FILES | SIGCHLD;
-       if(proc_mm) flags |= CLONE_VM;
-       pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack);
-       if(pid < 0)
-               panic("start_userspace : clone failed, errno = %d", errno);
-
-       do {
-               CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
-               if(n < 0)
-                       panic("start_userspace : wait failed, errno = %d", 
-                             errno);
-       } while(WIFSTOPPED(status) && (WSTOPSIG(status) == SIGVTALRM));
-
-       if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
-               panic("start_userspace : expected SIGSTOP, got status = %d",
-                     status);
-
-       if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL, (void *)PTRACE_O_TRACESYSGOOD) < 0)
-               panic("start_userspace : PTRACE_SETOPTIONS failed, errno=%d\n",
-                     errno);
-
-       if(munmap(stack, PAGE_SIZE) < 0)
-               panic("start_userspace : munmap failed, errno = %d\n", errno);
-
-       return(pid);
+       /* 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 userspace(union uml_pt_regs *regs)
+void release_thread_skas(struct task_struct *task)
 {
-       int err, status, op, pid = userspace_pid[0];
-       int local_using_sysemu; /*To prevent races if using_sysemu changes under us.*/
-
-       while(1){
-               restore_registers(pid, regs);
-
-               /* Now we set local_using_sysemu to be used for one loop */
-               local_using_sysemu = get_using_sysemu();
-
-               op = SELECT_PTRACE_OPERATION(local_using_sysemu, singlestepping(NULL));
-
-               err = ptrace(op, pid, 0, 0);
-               if(err)
-                       panic("userspace - could not resume userspace process, "
-                             "pid=%d, ptrace operation = %d, errno = %d\n",
-                             op, errno);
-
-               CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED));
-               if(err < 0)
-                       panic("userspace - waitpid failed, errno = %d\n", 
-                             errno);
-
-               regs->skas.is_user = 1;
-               save_registers(pid, regs);
-               UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */
-
-               if(WIFSTOPPED(status)){
-                       switch(WSTOPSIG(status)){
-                       case SIGSEGV:
-                                if(PTRACE_FULL_FAULTINFO || !ptrace_faultinfo)
-                                        user_signal(SIGSEGV, regs, pid);
-                                else handle_segv(pid, regs);
-                               break;
-                       case SIGTRAP + 0x80:
-                               handle_trap(pid, regs, local_using_sysemu);
-                               break;
-                       case SIGTRAP:
-                               relay_signal(SIGTRAP, regs);
-                               break;
-                       case SIGIO:
-                       case SIGVTALRM:
-                       case SIGILL:
-                       case SIGBUS:
-                       case SIGFPE:
-                       case SIGWINCH:
-                                user_signal(WSTOPSIG(status), regs, pid);
-                               break;
-                       default:
-                               printk("userspace - child stopped with signal "
-                                      "%d\n", WSTOPSIG(status));
-                       }
-                       pid = userspace_pid[0];
-                       interrupt_end();
-
-                       /* Avoid -ERESTARTSYS handling in host */
-                       PT_SYSCALL_NR(regs->skas.regs) = -1;
-               }
-       }
 }
-#define INIT_JMP_NEW_THREAD 0
-#define INIT_JMP_REMOVE_SIGSTACK 1
-#define INIT_JMP_CALLBACK 2
-#define INIT_JMP_HALT 3
-#define INIT_JMP_REBOOT 4
-
 
-int copy_context_skas0(unsigned long new_stack, int pid)
+/* Called magically, see new_thread_handler above */
+void fork_handler(void)
 {
-       int err;
-       unsigned long regs[MAX_REG_NR];
-       unsigned long current_stack = current_stub_stack();
-       struct stub_data *data = (struct stub_data *) current_stack;
-       struct stub_data *child_data = (struct stub_data *) new_stack;
-       __u64 new_offset;
-       int new_fd = phys_mapping(to_phys((void *)new_stack), &new_offset);
-
-       /* prepare offset and fd of child's stack as argument for parent's
-        * and child's mmap2 calls
-        */
-       *data = ((struct stub_data) { .offset   = MMAP_OFFSET(new_offset),
-                                     .fd       = new_fd,
-                                     .timer    = ((struct itimerval)
-                                                  { { 0, 1000000 / hz() },
-                                                    { 0, 1000000 / hz() }})});
-       get_safe_registers(regs);
-
-       /* Set parent's instruction pointer to start of clone-stub */
-       regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
-                               (unsigned long) stub_clone_handler -
-                               (unsigned long) &__syscall_stub_start;
-       regs[REGS_SP_INDEX] = UML_CONFIG_STUB_DATA + PAGE_SIZE -
-               sizeof(void *);
-       err = ptrace_setregs(pid, regs);
-       if(err < 0)
-               panic("copy_context_skas0 : PTRACE_SETREGS failed, "
-                     "pid = %d, errno = %d\n", pid, errno);
-
-       /* set a well known return code for detection of child write failure */
-       child_data->err = 12345678;
-
-       /* Wait, until parent has finished its work: read child's pid from
-        * parent's stack, and check, if bad result.
-        */
-       wait_stub_done(pid, 0, "copy_context_skas0");
+       force_flush_all();
+       if(current->thread.prev_sched == NULL)
+               panic("blech");
 
-       pid = data->err;
-       if(pid < 0)
-               panic("copy_context_skas0 - stub-parent reports error %d\n",
-                     pid);
+       schedule_tail(current->thread.prev_sched);
 
-       /* Wait, until child has finished too: read child's result from
-        * child's stack and check it.
-        */
-       wait_stub_done(pid, -1, "copy_context_skas0");
-       if (child_data->err != UML_CONFIG_STUB_DATA)
-               panic("copy_context_skas0 - stub-child reports error %d\n",
-                     child_data->err);
+       /* 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);
 
-       if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL,
-                  (void *)PTRACE_O_TRACESYSGOOD) < 0)
-               panic("copy_context_skas0 : PTRACE_SETOPTIONS failed, "
-                     "errno = %d\n", errno);
+       current->thread.prev_sched = NULL;
 
-       return pid;
-}
+/* Handle any immediate reschedules or signals */
+       interrupt_end();
 
-/*
- * This is used only, if stub pages are needed, while proc_mm is
- * availabl. Opening /proc/mm creates a new mm_context, which lacks
- * the stub-pages. Thus, we map them using /proc/mm-fd
- */
-void map_stub_pages(int fd, unsigned long code,
-                   unsigned long data, unsigned long stack)
-{
-       struct proc_mm_op mmop;
-       int n;
-
-       mmop = ((struct proc_mm_op) { .op        = MM_MMAP,
-                                     .u         =
-                                     { .mmap    =
-                                       { .addr    = code,
-                                         .len     = PAGE_SIZE,
-                                         .prot    = PROT_EXEC,
-                                         .flags   = MAP_FIXED | MAP_PRIVATE,
-                                         .fd      = stub_code_fd,
-                                         .offset  = stub_code_offset
-       } } });
-       n = os_write_file(fd, &mmop, sizeof(mmop));
-       if(n != sizeof(mmop))
-               panic("map_stub_pages : /proc/mm map for code failed, "
-                     "err = %d\n", -n);
-
-       if ( stack ) {
-               __u64 map_offset;
-               int map_fd = phys_mapping(to_phys((void *)stack), &map_offset);
-               mmop = ((struct proc_mm_op)
-                               { .op        = MM_MMAP,
-                                 .u         =
-                                 { .mmap    =
-                                   { .addr    = data,
-                                     .len     = PAGE_SIZE,
-                                     .prot    = PROT_READ | PROT_WRITE,
-                                     .flags   = MAP_FIXED | MAP_SHARED,
-                                     .fd      = map_fd,
-                                     .offset  = map_offset
-               } } });
-               n = os_write_file(fd, &mmop, sizeof(mmop));
-               if(n != sizeof(mmop))
-                       panic("map_stub_pages : /proc/mm map for data failed, "
-                             "err = %d\n", -n);
-       }
+       userspace(&current->thread.regs.regs);
 }
 
-void new_thread(void *stack, void **switch_buf_ptr, void **fork_buf_ptr,
-               void (*handler)(int))
+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)
 {
-       unsigned long flags;
-       sigjmp_buf switch_buf, fork_buf;
-
-       *switch_buf_ptr = &switch_buf;
-       *fork_buf_ptr = &fork_buf;
-
-       /* Somewhat subtle - siglongjmp restores the signal mask before doing
-        * the longjmp.  This means that when jumping from one stack to another
-        * when the target stack has interrupts enabled, an interrupt may occur
-        * on the source stack.  This is bad when starting up a process because
-        * it's not supposed to get timer ticks until it has been scheduled.
-        * So, we disable interrupts around the sigsetjmp to ensure that
-        * they can't happen until we get back here where they are safe.
-        */
-       flags = get_signals();
-       block_signals();
-       if(sigsetjmp(fork_buf, 1) == 0)
-               new_thread_proc(stack, handler);
+       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;
 
-       remove_sigstack();
+               handler = fork_handler;
 
-       set_signals(flags);
+               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);
 }
 
-void thread_wait(void *sw, void *fb)
+int new_mm(unsigned long stack)
 {
-       sigjmp_buf buf, **switch_buf = sw, *fork_buf;
+       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);
 
-       *switch_buf = &buf;
-       fork_buf = fb;
-       if(sigsetjmp(buf, 1) == 0)
-               siglongjmp(*fork_buf, INIT_JMP_REMOVE_SIGSTACK);
+       return(fd);
 }
 
-void switch_threads(void *me, void *next)
+void init_idle_skas(void)
 {
-       sigjmp_buf my_buf, **me_ptr = me, *next_buf = next;
-       
-       *me_ptr = &my_buf;
-       if(sigsetjmp(my_buf, 1) == 0)
-               siglongjmp(*next_buf, 1);
+       cpu_tasks[current_thread->cpu].pid = os_getpid();
+       default_idle();
 }
 
-static sigjmp_buf initial_jmpbuf;
+extern void start_kernel(void);
 
-/* XXX Make these percpu */
-static void (*cb_proc)(void *arg);
-static void *cb_arg;
-static sigjmp_buf *cb_back;
-
-int start_idle_thread(void *stack, void *switch_buf_ptr, void **fork_buf_ptr)
+static int start_kernel_proc(void *unused)
 {
-       sigjmp_buf **switch_buf = switch_buf_ptr;
-       int n;
-
-       set_handler(SIGWINCH, (__sighandler_t) sig_handler,
-                   SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGALRM,
-                   SIGVTALRM, -1);
-
-       *fork_buf_ptr = &initial_jmpbuf;
-       n = sigsetjmp(initial_jmpbuf, 1);
-        switch(n){
-        case INIT_JMP_NEW_THREAD:
-                new_thread_proc((void *) stack, new_thread_handler);
-                break;
-        case INIT_JMP_REMOVE_SIGSTACK:
-                remove_sigstack();
-                break;
-        case INIT_JMP_CALLBACK:
-               (*cb_proc)(cb_arg);
-               siglongjmp(*cb_back, 1);
-                break;
-        case INIT_JMP_HALT:
-               kmalloc_ok = 0;
-               return(0);
-        case INIT_JMP_REBOOT:
-               kmalloc_ok = 0;
-               return(1);
-        default:
-                panic("Bad sigsetjmp return in start_idle_thread - %d\n", n);
-       }
-       siglongjmp(**switch_buf, 1);
+       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);
 }
 
-void initial_thread_cb_skas(void (*proc)(void *), void *arg)
-{
-       sigjmp_buf here;
+extern int userspace_pid[];
 
-       cb_proc = proc;
-       cb_arg = arg;
-       cb_back = &here;
+int start_uml_skas(void)
+{
+       if(proc_mm)
+               userspace_pid[0] = start_userspace(0);
 
-       block_signals();
-       if(sigsetjmp(here, 1) == 0)
-               siglongjmp(initial_jmpbuf, INIT_JMP_CALLBACK);
-       unblock_signals();
+       init_new_thread_signals();
 
-       cb_proc = NULL;
-       cb_arg = NULL;
-       cb_back = NULL;
+       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));
 }
 
-void halt_skas(void)
+int external_pid_skas(struct task_struct *task)
 {
-       block_signals();
-       siglongjmp(initial_jmpbuf, INIT_JMP_HALT);
+#warning Need to look up userspace_pid by cpu
+       return(userspace_pid[0]);
 }
 
-void reboot_skas(void)
+int thread_pid_skas(struct task_struct *task)
 {
-       block_signals();
-       siglongjmp(initial_jmpbuf, INIT_JMP_REBOOT);
+#warning Need to look up userspace_pid by cpu
+       return(userspace_pid[0]);
 }
 
-void switch_mm_skas(struct mm_id *mm_idp)
+void kill_off_processes_skas(void)
 {
-       int err;
-
-#warning need cpu pid in switch_mm_skas
-       if(proc_mm){
-               err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0,
-                            mm_idp->u.mm_fd);
-               if(err)
-                       panic("switch_mm_skas - PTRACE_SWITCH_MM failed, "
-                             "errno = %d\n", errno);
+       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);
+               }
        }
-       else userspace_pid[0] = mm_idp->u.pid;
 }
 
-/*
- * 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:
- */
+unsigned long current_stub_stack(void)
+{
+       if(current->mm == NULL)
+               return(0);
+
+       return(current->mm->context.skas.id.stack);
+}