Subversion Repositories openrisc_2011-10-31

/* Linuxthreads - a simple clone()-based implementation of Posix        */

/* threads for Linux.                                                   */

/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr)              */

/*                                                                      */

/* This program is free software; you can redistribute it and/or        */

/* modify it under the terms of the GNU Library General Public License  */

/* as published by the Free Software Foundation; either version 2       */

/* of the License, or (at your option) any later version.               */

/*                                                                      */

/* This program is distributed in the hope that it will be useful,      */

/* but WITHOUT ANY WARRANTY; without even the implied warranty of       */

/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        */

/* GNU Library General Public License for more details.                 */

/* The "thread manager" thread: manages creation and termination of threads */

#include <errno.h>

#define __USE_MISC

#include <sched.h>

#include <stddef.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <sys/poll.h>           /* for poll */

#include <sys/mman.h>           /* for mmap */

#include <sys/param.h>

#include <sys/time.h>

#include <sys/wait.h>           /* for waitpid macros */

#include "pthread.h"

#include "internals.h"

#include "spinlock.h"

#include "restart.h"

#include "semaphore.h"

/* Array of active threads. Entry 0 is reserved for the initial thread. */

struct pthread_handle_struct __pthread_handles[PTHREAD_THREADS_MAX] =

{ { __LOCK_INITIALIZER, &__pthread_initial_thread, 0},

  { __LOCK_INITIALIZER, &__pthread_manager_thread, 0}, /* All NULLs */ };

/* For debugging purposes put the maximum number of threads in a variable.  */

const int __linuxthreads_pthread_threads_max = PTHREAD_THREADS_MAX;

#ifndef THREAD_SELF

/* Indicate whether at least one thread has a user-defined stack (if 1),

   or if all threads have stacks supplied by LinuxThreads (if 0). */

int __pthread_nonstandard_stacks;

#endif

/* Number of active entries in __pthread_handles (used by gdb) */

volatile int __pthread_handles_num = 2;

/* Whether to use debugger additional actions for thread creation

   (set to 1 by gdb) */

volatile int __pthread_threads_debug;

/* Globally enabled events.  */

volatile td_thr_events_t __pthread_threads_events;

/* Pointer to thread descriptor with last event.  */

volatile pthread_descr __pthread_last_event;

/* Mapping from stack segment to thread descriptor. */

/* Stack segment numbers are also indices into the __pthread_handles array. */

/* Stack segment number 0 is reserved for the initial thread. */

#if FLOATING_STACKS

# define thread_segment(seq) NULL

#else

static inline pthread_descr thread_segment(int seg)

{

  return (pthread_descr)(THREAD_STACK_START_ADDRESS - (seg - 1) * STACK_SIZE)

         - 1;

}

#endif

/* Flag set in signal handler to record child termination */

static volatile int terminated_children;

/* Flag set when the initial thread is blocked on pthread_exit waiting

   for all other threads to terminate */

static int main_thread_exiting;

/* Counter used to generate unique thread identifier.

   Thread identifier is pthread_threads_counter + segment. */

static pthread_t pthread_threads_counter;

/* Forward declarations */

static int pthread_handle_create(pthread_t *thread, const pthread_attr_t *attr,

                                 void * (*start_routine)(void *), void *arg,

                                 sigset_t *mask, int father_pid,

                                 int report_events,

                                 td_thr_events_t *event_maskp);

static void pthread_handle_free(pthread_t th_id);

static void pthread_handle_exit(pthread_descr issuing_thread, int exitcode)

     __attribute__ ((noreturn));

static void pthread_reap_children(void);

static void pthread_kill_all_threads(int sig, int main_thread_also);

static void pthread_for_each_thread(void *arg,

    void (*fn)(void *, pthread_descr));

/* The server thread managing requests for thread creation and termination */

int

__attribute__ ((noreturn))

__pthread_manager(void *arg)

{

  int reqfd = (int) (long int) arg;

  struct pollfd ufd;

  sigset_t manager_mask;

  int n;

  struct pthread_request request;

  /* If we have special thread_self processing, initialize it.  */

#ifdef INIT_THREAD_SELF

  INIT_THREAD_SELF(&__pthread_manager_thread, 1);

#endif

  /* Set the error variable.  */

  __pthread_manager_thread.p_reentp = &__pthread_manager_thread.p_reent;

  __pthread_manager_thread.p_h_errnop = &__pthread_manager_thread.p_h_errno;

  /* Block all signals except __pthread_sig_cancel and SIGTRAP */

  sigfillset(&manager_mask);

  sigdelset(&manager_mask, __pthread_sig_cancel); /* for thread termination */

  sigdelset(&manager_mask, SIGTRAP);            /* for debugging purposes */

  if (__pthread_threads_debug && __pthread_sig_debug > 0)

    sigdelset(&manager_mask, __pthread_sig_debug);

  sigprocmask(SIG_SETMASK, &manager_mask, NULL);

  /* Raise our priority to match that of main thread */

  __pthread_manager_adjust_prio(__pthread_main_thread->p_priority);

  /* Synchronize debugging of the thread manager */

  n = TEMP_FAILURE_RETRY(__libc_read(reqfd, (char *)&request,

                                     sizeof(request)));

  ASSERT(n == sizeof(request) && request.req_kind == REQ_DEBUG);

  ufd.fd = reqfd;

  ufd.events = POLLIN;

  /* Enter server loop */

  while(1) {

    n = __poll(&ufd, 1, 2000);

    /* Check for termination of the main thread */

    if (getppid() == 1) {

      pthread_kill_all_threads(SIGKILL, 0);

      _exit(0);

    }

    /* Check for dead children */

    if (terminated_children) {

      terminated_children = 0;

      pthread_reap_children();

    }

    /* Read and execute request */

    if (n == 1 && (ufd.revents & POLLIN)) {

      n = TEMP_FAILURE_RETRY(__libc_read(reqfd, (char *)&request,

                                         sizeof(request)));

#ifdef DEBUG

      if (n < 0) {

        char d[64];

        write(STDERR_FILENO, d, snprintf(d, sizeof(d), "*** read err %m\n"));

      } else if (n != sizeof(request)) {

        write(STDERR_FILENO, "*** short read in manager\n", 26);

      }

#endif

      switch(request.req_kind) {

      case REQ_CREATE:

        request.req_thread->p_retcode =

          pthread_handle_create((pthread_t *) &request.req_thread->p_retval,

                                request.req_args.create.attr,

                                request.req_args.create.fn,

                                request.req_args.create.arg,

                                &request.req_args.create.mask,

                                request.req_thread->p_pid,

                                request.req_thread->p_report_events,

                                &request.req_thread->p_eventbuf.eventmask);

        restart(request.req_thread);

        break;

      case REQ_FREE:

        pthread_handle_free(request.req_args.free.thread_id);

        break;

      case REQ_PROCESS_EXIT:

        pthread_handle_exit(request.req_thread,

                            request.req_args.exit.code);

        /* NOTREACHED */

        break;

      case REQ_MAIN_THREAD_EXIT:

        main_thread_exiting = 1;

        /* Reap children in case all other threads died and the signal handler

           went off before we set main_thread_exiting to 1, and therefore did

           not do REQ_KICK. */

        pthread_reap_children();

        if (__pthread_main_thread->p_nextlive == __pthread_main_thread) {

          restart(__pthread_main_thread);

          /* The main thread will now call exit() which will trigger an

             __on_exit handler, which in turn will send REQ_PROCESS_EXIT

             to the thread manager. In case you are wondering how the

             manager terminates from its loop here. */

        }

        break;

      case REQ_POST:

        __new_sem_post(request.req_args.post);

        break;

      case REQ_DEBUG:

        /* Make gdb aware of new thread and gdb will restart the

           new thread when it is ready to handle the new thread. */

        if (__pthread_threads_debug && __pthread_sig_debug > 0)

          raise(__pthread_sig_debug);

        break;

      case REQ_KICK:

        /* This is just a prod to get the manager to reap some

           threads right away, avoiding a potential delay at shutdown. */

        break;

      case REQ_FOR_EACH_THREAD:

        pthread_for_each_thread(request.req_args.for_each.arg,

                                request.req_args.for_each.fn);

        restart(request.req_thread);

        break;

      }

    }

  }

}

int __pthread_manager_event(void *arg)

{

  /* If we have special thread_self processing, initialize it.  */

#ifdef INIT_THREAD_SELF

  INIT_THREAD_SELF(&__pthread_manager_thread, 1);

#endif

  /* Get the lock the manager will free once all is correctly set up.  */

  __pthread_lock (THREAD_GETMEM((&__pthread_manager_thread), p_lock), NULL);

  /* Free it immediately.  */

  __pthread_unlock (THREAD_GETMEM((&__pthread_manager_thread), p_lock));

  return __pthread_manager(arg);

}

/* Process creation */

static int

__attribute__ ((noreturn))

pthread_start_thread(void *arg)

{

  pthread_descr self = (pthread_descr) arg;

  struct pthread_request request;

  void * outcome;

#if HP_TIMING_AVAIL

  hp_timing_t tmpclock;

#endif

  /* Initialize special thread_self processing, if any.  */

#ifdef INIT_THREAD_SELF

  INIT_THREAD_SELF(self, self->p_nr);

#endif

#if HP_TIMING_AVAIL

  HP_TIMING_NOW (tmpclock);

  THREAD_SETMEM (self, p_cpuclock_offset, tmpclock);

#endif

  /* Make sure our pid field is initialized, just in case we get there

     before our father has initialized it. */

  THREAD_SETMEM(self, p_pid, __getpid());

  /* Initial signal mask is that of the creating thread. (Otherwise,

     we'd just inherit the mask of the thread manager.) */

  sigprocmask(SIG_SETMASK, &self->p_start_args.mask, NULL);

  /* Set the scheduling policy and priority for the new thread, if needed */

  if (THREAD_GETMEM(self, p_start_args.schedpolicy) >= 0)

    /* Explicit scheduling attributes were provided: apply them */

    __sched_setscheduler(THREAD_GETMEM(self, p_pid),

                         THREAD_GETMEM(self, p_start_args.schedpolicy),

                         &self->p_start_args.schedparam);

  else if (__pthread_manager_thread.p_priority > 0)

    /* Default scheduling required, but thread manager runs in realtime

       scheduling: switch new thread to SCHED_OTHER policy */

    {

      struct sched_param default_params;

      default_params.sched_priority = 0;

      __sched_setscheduler(THREAD_GETMEM(self, p_pid),

                           SCHED_OTHER, &default_params);

    }

  /* Make gdb aware of new thread */

  if (__pthread_threads_debug && __pthread_sig_debug > 0) {

    request.req_thread = self;

    request.req_kind = REQ_DEBUG;

    TEMP_FAILURE_RETRY(__libc_write(__pthread_manager_request,

                                    (char *) &request, sizeof(request)));

    suspend(self);

  }

  /* Run the thread code */

  outcome = self->p_start_args.start_routine(THREAD_GETMEM(self,

                                                           p_start_args.arg));

  /* Exit with the given return value */

  __pthread_do_exit(outcome, CURRENT_STACK_FRAME);

}

static int

__attribute__ ((noreturn))

pthread_start_thread_event(void *arg)

{

  pthread_descr self = (pthread_descr) arg;

#ifdef INIT_THREAD_SELF

  INIT_THREAD_SELF(self, self->p_nr);

#endif

  /* Make sure our pid field is initialized, just in case we get there

     before our father has initialized it. */

  THREAD_SETMEM(self, p_pid, __getpid());

  /* Get the lock the manager will free once all is correctly set up.  */

  __pthread_lock (THREAD_GETMEM(self, p_lock), NULL);

  /* Free it immediately.  */

  __pthread_unlock (THREAD_GETMEM(self, p_lock));

  /* Continue with the real function.  */

  pthread_start_thread (arg);

}

static int pthread_allocate_stack(const pthread_attr_t *attr,

                                  pthread_descr default_new_thread,

                                  int pagesize,

                                  pthread_descr * out_new_thread,

                                  char ** out_new_thread_bottom,

                                  char ** out_guardaddr,

                                  size_t * out_guardsize)

{

  pthread_descr new_thread;

  char * new_thread_bottom;

  char * guardaddr;

  size_t stacksize, guardsize;

  if (attr != NULL && attr->__stackaddr_set)

    {

#ifdef _STACK_GROWS_UP

      /* The user provided a stack. */

      new_thread = (pthread_descr) attr->__stackaddr;

      new_thread_bottom = (char *) (new_thread + 1);

      guardaddr = attr->__stackaddr + attr->__stacksize;

      guardsize = 0;

#else

      /* The user provided a stack.  For now we interpret the supplied

         address as 1 + the highest addr. in the stack segment.  If a

         separate register stack is needed, we place it at the low end

         of the segment, relying on the associated stacksize to

         determine the low end of the segment.  This differs from many

         (but not all) other pthreads implementations.  The intent is

         that on machines with a single stack growing toward higher

         addresses, stackaddr would be the lowest address in the stack

         segment, so that it is consistently close to the initial sp

         value. */

      new_thread =

        (pthread_descr) ((long)(attr->__stackaddr) & -sizeof(void *)) - 1;

      new_thread_bottom = (char *) attr->__stackaddr - attr->__stacksize;

      guardaddr = new_thread_bottom;

      guardsize = 0;

#endif

#ifndef THREAD_SELF

      __pthread_nonstandard_stacks = 1;

#endif

      /* Clear the thread data structure.  */

      memset (new_thread, '\0', sizeof (*new_thread));

    }

  else

    {

#ifdef NEED_SEPARATE_REGISTER_STACK

      size_t granularity = 2 * pagesize;

      /* Try to make stacksize/2 a multiple of pagesize */

#else

      size_t granularity = pagesize;

#endif

      void *map_addr;

      /* Allocate space for stack and thread descriptor at default address */

#if FLOATING_STACKS

      if (attr != NULL)

        {

          guardsize = page_roundup (attr->__guardsize, granularity);

          stacksize = __pthread_max_stacksize - guardsize;

          stacksize = MIN (stacksize,

                           page_roundup (attr->__stacksize, granularity));

        }

      else

        {

          guardsize = granularity;

          stacksize = __pthread_max_stacksize - guardsize;

        }

      map_addr = mmap(NULL, stacksize + guardsize,

                      PROT_READ | PROT_WRITE | PROT_EXEC,

                      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

      if (map_addr == MAP_FAILED)

        /* No more memory available.  */

        return -1;

# ifdef NEED_SEPARATE_REGISTER_STACK

      guardaddr = map_addr + stacksize / 2;

      if (guardsize > 0)

        mprotect (guardaddr, guardsize, PROT_NONE);

      new_thread_bottom = (char *) map_addr;

      new_thread = ((pthread_descr) (new_thread_bottom + stacksize

                                     + guardsize)) - 1;

# elif _STACK_GROWS_DOWN

      guardaddr = map_addr;

      if (guardsize > 0)

        mprotect (guardaddr, guardsize, PROT_NONE);

      new_thread_bottom = (char *) map_addr + guardsize;

      new_thread = ((pthread_descr) (new_thread_bottom + stacksize)) - 1;

# elif _STACK_GROWS_UP

      guardaddr = map_addr + stacksize;

      if (guardsize > 0)

        mprotect (guardaddr, guardsize, PROT_NONE);

      new_thread = (pthread_descr) map_addr;

      new_thread_bottom = (char *) (new_thread + 1);

# else

#  error You must define a stack direction

# endif /* Stack direction */

#else /* !FLOATING_STACKS */

      void *res_addr;

      if (attr != NULL)

        {

          guardsize = page_roundup (attr->__guardsize, granularity);

          stacksize = STACK_SIZE - guardsize;

          stacksize = MIN (stacksize,

                           page_roundup (attr->__stacksize, granularity));

        }

      else

        {

          guardsize = granularity;

          stacksize = STACK_SIZE - granularity;

        }

# ifdef NEED_SEPARATE_REGISTER_STACK

      new_thread = default_new_thread;

      new_thread_bottom = (char *) (new_thread + 1) - stacksize - guardsize;

      /* Includes guard area, unlike the normal case.  Use the bottom

       end of the segment as backing store for the register stack.

       Needed on IA64.  In this case, we also map the entire stack at

       once.  According to David Mosberger, that's cheaper.  It also

       avoids the risk of intermittent failures due to other mappings

       in the same region.  The cost is that we might be able to map

       slightly fewer stacks.  */

      /* First the main stack: */

      map_addr = (caddr_t)((char *)(new_thread + 1) - stacksize / 2);

      res_addr = mmap(map_addr, stacksize / 2,

                      PROT_READ | PROT_WRITE | PROT_EXEC,

                      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

      if (res_addr != map_addr)

        {

          /* Bad luck, this segment is already mapped. */

          if (res_addr != MAP_FAILED)

            munmap(res_addr, stacksize / 2);

          return -1;

        }

      /* Then the register stack:       */

      map_addr = (caddr_t)new_thread_bottom;

      res_addr = mmap(map_addr, stacksize/2,

                      PROT_READ | PROT_WRITE | PROT_EXEC,

                      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

      if (res_addr != map_addr)

        {

          if (res_addr != MAP_FAILED)

            munmap(res_addr, stacksize / 2);

          munmap((caddr_t)((char *)(new_thread + 1) - stacksize/2),

                 stacksize/2);

          return -1;

        }

      guardaddr = new_thread_bottom + stacksize/2;

      /* We leave the guard area in the middle unmapped.        */

# else  /* !NEED_SEPARATE_REGISTER_STACK */

#  ifdef _STACK_GROWS_DOWN

      new_thread = default_new_thread;

      new_thread_bottom = (char *) (new_thread + 1) - stacksize;

      map_addr = new_thread_bottom - guardsize;

      res_addr = mmap(map_addr, stacksize + guardsize,

                      PROT_READ | PROT_WRITE | PROT_EXEC,

                      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

      if (res_addr != map_addr)

        {

          /* Bad luck, this segment is already mapped. */

          if (res_addr != MAP_FAILED)

            munmap (res_addr, stacksize + guardsize);

          return -1;

        }

      /* We manage to get a stack.  Protect the guard area pages if

         necessary.  */

      guardaddr = map_addr;

      if (guardsize > 0)

        mprotect (guardaddr, guardsize, PROT_NONE);

#  else

      /* The thread description goes at the bottom of this area, and

       * the stack starts directly above it.

       */

      new_thread = (pthread_descr)((unsigned long)default_new_thread &~ (STACK_SIZE - 1));

      map_addr = mmap(new_thread, stacksize + guardsize,

                      PROT_READ | PROT_WRITE | PROT_EXEC,

                      MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

      if (map_addr == MAP_FAILED)

          return -1;

      new_thread_bottom = map_addr + sizeof(*new_thread);

      guardaddr = map_addr + stacksize;

      if (guardsize > 0)

          mprotect (guardaddr, guardsize, PROT_NONE);

#  endif /* stack direction */

# endif  /* !NEED_SEPARATE_REGISTER_STACK */

#endif   /* !FLOATING_STACKS */

    }

  *out_new_thread = new_thread;

  *out_new_thread_bottom = new_thread_bottom;

  *out_guardaddr = guardaddr;

  *out_guardsize = guardsize;

  return 0;

}

static int pthread_handle_create(pthread_t *thread, const pthread_attr_t *attr,

                                 void * (*start_routine)(void *), void *arg,

                                 sigset_t * mask, int father_pid,

                                 int report_events,

                                 td_thr_events_t *event_maskp)

{

  size_t sseg;

  int pid;

  pthread_descr new_thread;

  char * new_thread_bottom;

  pthread_t new_thread_id;

  char *guardaddr = NULL;

  size_t guardsize = 0;

  int pagesize = __getpagesize();

  /* First check whether we have to change the policy and if yes, whether

     we can  do this.  Normally this should be done by examining the

     return value of the __sched_setscheduler call in pthread_start_thread

     but this is hard to implement.  FIXME  */

  if (attr != NULL && attr->__schedpolicy != SCHED_OTHER && geteuid () != 0)

    return EPERM;

  /* Find a free segment for the thread, and allocate a stack if needed */

  for (sseg = 2; ; sseg++)

    {

      if (sseg >= PTHREAD_THREADS_MAX)

        return EAGAIN;

      if (__pthread_handles[sseg].h_descr != NULL)

        continue;

      if (pthread_allocate_stack(attr, thread_segment(sseg),

                                 pagesize,

                                 &new_thread, &new_thread_bottom,

                                 &guardaddr, &guardsize) == 0)

        break;

    }

  __pthread_handles_num++;

  /* Allocate new thread identifier */

  pthread_threads_counter += PTHREAD_THREADS_MAX;

  new_thread_id = sseg + pthread_threads_counter;

  /* Initialize the thread descriptor.  Elements which have to be

     initialized to zero already have this value.  */

  new_thread->p_tid = new_thread_id;

  new_thread->p_lock = &(__pthread_handles[sseg].h_lock);

  new_thread->p_cancelstate = PTHREAD_CANCEL_ENABLE;

  new_thread->p_canceltype = PTHREAD_CANCEL_DEFERRED;

  new_thread->p_reentp = &new_thread->p_reent;

  _REENT_INIT_PTR(new_thread->p_reentp);

  new_thread->p_h_errnop = &new_thread->p_h_errno;

  new_thread->p_resp = &new_thread->p_res;

  new_thread->p_guardaddr = guardaddr;

  new_thread->p_guardsize = guardsize;

  new_thread->p_header.data.self = new_thread;

  new_thread->p_nr = sseg;

  new_thread->p_inheritsched = attr ? attr->__inheritsched : 0;

  /* Initialize the thread handle */

  __pthread_init_lock(&__pthread_handles[sseg].h_lock);

  __pthread_handles[sseg].h_descr = new_thread;

  __pthread_handles[sseg].h_bottom = new_thread_bottom;

  /* Determine scheduling parameters for the thread */

  new_thread->p_start_args.schedpolicy = -1;

  if (attr != NULL) {

    new_thread->p_detached = attr->__detachstate;

    new_thread->p_userstack = attr->__stackaddr_set;

    switch(attr->__inheritsched) {

    case PTHREAD_EXPLICIT_SCHED:

      new_thread->p_start_args.schedpolicy = attr->__schedpolicy;

      memcpy (&new_thread->p_start_args.schedparam, &attr->__schedparam,

              sizeof (struct sched_param));

      break;

    case PTHREAD_INHERIT_SCHED:

      new_thread->p_start_args.schedpolicy = __sched_getscheduler(father_pid);

      __sched_getparam(father_pid, &new_thread->p_start_args.schedparam);

      break;

    }

    new_thread->p_priority =

      new_thread->p_start_args.schedparam.__sched_priority;

  }

  /* Finish setting up arguments to pthread_start_thread */

  new_thread->p_start_args.start_routine = start_routine;

  new_thread->p_start_args.arg = arg;

  new_thread->p_start_args.mask = *mask;

  /* Make the new thread ID available already now.  If any of the later

     functions fail we return an error value and the caller must not use

     the stored thread ID.  */

  *thread = new_thread_id;

  /* Raise priority of thread manager if needed */

  __pthread_manager_adjust_prio(new_thread->p_priority);

  /* Do the cloning.  We have to use two different functions depending

     on whether we are debugging or not.  */

  pid = 0;       /* Note that the thread never can have PID zero.  */

  if (report_events)

    {

      /* See whether the TD_CREATE event bit is set in any of the

         masks.  */

      int idx = __td_eventword (TD_CREATE);

      uint32_t mask = __td_eventmask (TD_CREATE);

      if ((mask & (__pthread_threads_events.event_bits[idx]

                   | event_maskp->event_bits[idx])) != 0)

        {

          /* Lock the mutex the child will use now so that it will stop.  */

          __pthread_lock(new_thread->p_lock, NULL);

          /* We have to report this event.  */

#ifdef NEED_SEPARATE_REGISTER_STACK

          /* Perhaps this version should be used on all platforms. But

           this requires that __clone2 be uniformly supported

           everywhere.

           And there is some argument for changing the __clone2

           interface to pass sp and bsp instead, making it more IA64

           specific, but allowing stacks to grow outward from each

           other, to get less paging and fewer mmaps.  */

          pid = __clone2(pthread_start_thread_event,

                 (void **)new_thread_bottom,

                         (char *)new_thread - new_thread_bottom,

                         CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND |

                         __pthread_sig_cancel, new_thread);

#elif _STACK_GROWS_UP

          pid = __clone(pthread_start_thread_event, (void **) new_thread_bottom,

                        CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND |

                        __pthread_sig_cancel, new_thread);

#else

          pid = __clone(pthread_start_thread_event, (void **) new_thread,

                        CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND |

                        __pthread_sig_cancel, new_thread);

#endif

          if (pid != -1)

            {

              /* Now fill in the information about the new thread in

                 the newly created thread's data structure.  We cannot let

                 the new thread do this since we don't know whether it was

                 already scheduled when we send the event.  */

              new_thread->p_eventbuf.eventdata = new_thread;

              new_thread->p_eventbuf.eventnum = TD_CREATE;

              __pthread_last_event = new_thread;

              /* We have to set the PID here since the callback function

                 in the debug library will need it and we cannot guarantee

                 the child got scheduled before the debugger.  */

              new_thread->p_pid = pid;

              /* Now call the function which signals the event.  */

              __linuxthreads_create_event ();

              /* Now restart the thread.  */

              __pthread_unlock(new_thread->p_lock);

            }