/* Process information queries
   Copyright (C) 1992,93,94,95,96,99,2000,01,02,21
   Free Software Foundation, Inc.

   This file is part of the GNU Hurd.

   The GNU Hurd is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   The GNU Hurd 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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with the GNU Hurd; see the file COPYING.  If not, write to
   the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */

/* Written by Michael I. Bushnell.  */

#include <mach.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <hurd/hurd_types.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <sys/resource.h>
#include <assert-backtrace.h>
#include <hurd/msg.h>

#include "proc.h"
#include "process_S.h"

/* Returns true if PROC1 has `owner' privileges over PROC2 (and can thus get its
   task port &c).  In the usual case, this checks that PROC1 already has all
   UID's that PROC2 has, meaning PROC1 would not gain access to any new UID's
   this way.  The reason the check is performed using PROC1's both effective and
   available UID's and not just its effective UID's is that POSIX requires
   kill(2) to work when "the real or effective user ID of the sending process
   shall match the real or saved set-user-ID of the receiving process".  */
int
check_owner (struct proc *proc1, struct proc *proc2)
{
  /* Anyone can access themselves.  */
  if (proc1 == proc2)
    return 1;

  /* If PROC1 is unowned, it cannot access anyone else.  */
  if (!proc1->p_id || !proc1->p_id->i_nuids)
    return 0;

  /* Root can always access anyone.  */
  if (check_uid (proc1, 0))
    return 1;

  /* Nobody (except root) can access an unowned process.  */
  if (!proc2->p_id || !proc2->p_id->i_nuids)
    return 0;

  /* Verify that PROC1 has all UIDs that PROC2 has.  */
  for (size_t i = 0; i < proc2->p_id->i_nuids; i++)
    if (!check_uid (proc1, proc2->p_id->i_uids[i]))
      return 0;

  return 1;
}


/* Implement S_proc_pid2task as described in <hurd/process.defs>. */
kern_return_t
S_proc_pid2task (struct proc *callerp,
	         pid_t pid,
	         task_t *t)
{
  struct proc *p;

  if (!callerp)
    return EOPNOTSUPP;

  p = pid_find_allow_zombie (pid);
  if (!p)
    return ESRCH;

  if (p->p_dead)
    {
      *t = MACH_PORT_NULL;
      return 0;
    }

  if (! check_owner (callerp, p))
    return EPERM;

  assert_backtrace (MACH_PORT_VALID (p->p_task));
  *t = p->p_task;

  return 0;
}

/* Implement proc_task2pid as described in <hurd/process.defs>. */
kern_return_t
S_proc_task2pid (struct proc *callerp,
	         task_t t,
	         pid_t *pid)
{
  struct proc *p = task_find (t);

  /* No need to check CALLERP here; we don't use it. */

  if (!p)
    return ESRCH;

  *pid = p->p_pid;
  mach_port_deallocate (mach_task_self (), t);
  return 0;
}

/* Implement proc_task2proc as described in <hurd/process.defs>. */
kern_return_t
S_proc_task2proc (struct proc *callerp,
		  task_t t,
		  mach_port_t *outproc,
		  mach_msg_type_name_t *outproc_type)
{
  struct proc *p = task_find (t);

  /* No need to check CALLERP here; we don't use it. */

  if (!p)
    return ESRCH;

  if (namespace_is_subprocess (p))
    {
      /* Relay it to the Subhurd's proc server (if any).  */
      error_t err;

      /* Release global lock while talking to the other proc server.  */
      pthread_mutex_unlock (&global_lock);

      err = proc_task2proc (p->p_task_namespace, t, outproc);

      pthread_mutex_lock (&global_lock);

      if (! err)
	{
	  *outproc_type = MACH_MSG_TYPE_MOVE_SEND;
	  mach_port_deallocate (mach_task_self (), t);
	  return 0;
	}

      /* Fallback.  */
    }

  *outproc = ports_get_right (p);
  *outproc_type = MACH_MSG_TYPE_MAKE_SEND;
  mach_port_deallocate (mach_task_self (), t);
  return 0;
}

/* Implement proc_proc2task as described in <hurd/process.defs>. */
kern_return_t
S_proc_proc2task (struct proc *p,
		  task_t *t)
{
  if (!p)
    return EOPNOTSUPP;
  *t = p->p_task;
  return 0;
}

/* Implement proc_pid2proc as described in <hurd/process.defs>. */
kern_return_t
S_proc_pid2proc (struct proc *callerp,
	         pid_t pid,
	         mach_port_t *outproc,
		 mach_msg_type_name_t *outproc_type)
{
  struct proc *p;

  if (!callerp)
    return EOPNOTSUPP;

  p = pid_find_allow_zombie (pid);
  if (!p)
    return ESRCH;

  if (p->p_dead)
    {
      *outproc = MACH_PORT_NULL;
      return 0;
    }

  if (! check_owner (callerp, p))
    return EPERM;

  if (namespace_is_subprocess (p))
    {
      /* Relay it to the Subhurd's proc server (if any).  */
      error_t err;

      /* Release global lock while talking to the other proc server.  */
      pthread_mutex_unlock (&global_lock);

      err = proc_task2proc (p->p_task_namespace, p->p_task, outproc);

      pthread_mutex_lock (&global_lock);

      if (! err)
	{
	  *outproc_type = MACH_MSG_TYPE_MOVE_SEND;
	  return 0;
	}

      /* Fallback.  */
    }

  *outproc = ports_get_right (p);
  *outproc_type = MACH_MSG_TYPE_MAKE_SEND;
  return 0;
}


/* Read a string starting at address ADDR in task T; set *STR to point at
   newly malloced storage holding it, and *LEN to its length with null.  */
static error_t
get_string (task_t t,
	    vm_address_t addr,
	    char **str, size_t *len)
{
  /* This version assumes that a string is never more than one
     page in length.  */

  vm_address_t readaddr;
  vm_address_t data;
  mach_msg_type_number_t readlen;
  error_t err;
  char *c;

  readaddr = trunc_page (addr);
  err = vm_read (t, readaddr, vm_page_size * 2, &data, &readlen);
  if (err == KERN_INVALID_ADDRESS)
    err = vm_read (t, readaddr, vm_page_size, &data, &readlen);
  if (err == MACH_SEND_INVALID_DEST)
    err = ESRCH;
  if (err)
    return err;

  /* Scan for a null.  */
  c = memchr ((char *) (data + (addr - readaddr)), '\0',
	      readlen - (addr - readaddr));
  if (c == NULL)
    err = KERN_INVALID_ADDRESS;
  else
    {
      c++;			/* Include the null.  */
      *len = c - (char *) (data + (addr - readaddr));
      *str = malloc (*len);
      if (*str == NULL)
	err = ENOMEM;
      else
	memcpy (*str, (char *) data + (addr - readaddr), *len);
    }

  munmap ((caddr_t) data, readlen);
  return err;
}

/* Read a vector of addresses (stored as are argv and envp) from task TASK
   found at address ADDR.  Set *VEC to point to newly malloced storage holding
   the addresses. */
static error_t
get_vector (task_t task,
	    vm_address_t addr,
	    vm_address_t **vec)
{
  vm_address_t readaddr;
  vm_size_t readsize;
  vm_address_t scanned;
  error_t err;

  *vec = NULL;
  readaddr = trunc_page (addr);
  readsize = 0;
  scanned = addr;
  do
    {
      vm_address_t data;
      mach_msg_type_number_t readlen = 0;
      vm_address_t *t;

      readsize += vm_page_size;
      err = vm_read (task, readaddr, readsize, &data, &readlen);
      if (err == MACH_SEND_INVALID_DEST)
	err = ESRCH;
      if (err)
	return err;

      /* Scan for a null.  */
      for (t = (vm_address_t *) (data + (scanned - readaddr));
	   t < (vm_address_t *) (data + readlen);
	   ++t)
	if (*t == 0)
	  {
	    ++t;		/* Include the null.  */
	    *vec = malloc ((char *)t - (char *)(data + (addr - readaddr)));
	    if (*vec == NULL)
	      err = ENOMEM;
	    else
	      memcpy (*vec, (char *)(data + (addr - readaddr)),
		     (char *)t - (char *)(data + (addr - readaddr)));
	    break;
	  }

      /* If we didn't find the null terminator, then we will loop
	 to read an additional page.  */
      scanned = readaddr + readlen;
      munmap ((caddr_t) data, readlen);
    } while (!err && *vec == NULL);

  return err;
}

/* Fetch an array of strings at address LOC in task T into
   BUF of size BUFLEN. */
static error_t
get_string_array (task_t t,
		  vm_address_t loc,
		  vm_address_t *buf,
		  mach_msg_type_number_t *buflen)
{
  char *bp;
  vm_address_t *vector, *vp;
  error_t err;
  vm_address_t origbuf = *buf;

  err = get_vector (t, loc, &vector);
  if (err)
    return err;

  bp = (char *) *buf;
  for (vp = vector; *vp; ++vp)
    {
      char *string;
      size_t len;

      err = get_string (t, *vp, &string, &len);
      if (err)
	{
	  free (vector);
	  if (*buf != origbuf)
	    munmap ((caddr_t) *buf, *buflen);
	  return err;
	}

      if (len > (char *) *buf + *buflen - bp)
	{
	  char *newbuf;
	  vm_size_t prev_len = bp - (char *) *buf;
	  vm_size_t newsize = *buflen * 2;

	  if (newsize < prev_len + len)
	    /* Since we will mmap whole pages anyway,
	       notice how much space we really have.  */
	    newsize = round_page (prev_len + len);

	  newbuf = mmap (0, newsize, PROT_READ|PROT_WRITE, MAP_ANON, 0, 0);
	  if (newbuf == MAP_FAILED)
	    {
	      err = errno;
	      free (string);
	      free (vector);
	      if (*buf != origbuf)
		munmap ((caddr_t) *buf, *buflen);
	      return err;
	    }

	  memcpy (newbuf, (char *) *buf, prev_len);
	  bp = newbuf + prev_len;
	  if (*buf != origbuf)
	    munmap ((caddr_t) *buf, *buflen);

	  *buf = (vm_address_t) newbuf;
	  *buflen = newsize;
	}

      memcpy (bp, string, len);
      bp += len;
      free (string);
    }

  free (vector);
  *buflen = bp - (char *) *buf;
  return 0;
}


/* Implement proc_getprocargs as described in <hurd/process.defs>. */
kern_return_t
S_proc_getprocargs (struct proc *callerp,
		    pid_t pid,
		    data_t *buf,
		    mach_msg_type_number_t *buflen)
{
  struct proc *p = pid_find (pid);

  /* No need to check CALLERP here; we don't use it. */

  if (!p)
    return ESRCH;

  if (namespace_is_subprocess (p))
    {
      /* Relay it to the Subhurd's proc server (if any).  */
      error_t err;
      pid_t pid_sub;

      /* Release global lock while talking to the other proc server.  */
      pthread_mutex_unlock (&global_lock);

      err = proc_task2pid (p->p_task_namespace, p->p_task, &pid_sub);
      if (! err)
	err = proc_getprocargs (p->p_task_namespace, pid_sub, buf, buflen);

      pthread_mutex_lock (&global_lock);

      if (! err)
	return 0;

      /* Fallback.  */
    }

  return get_string_array (p->p_task, p->p_argv, (vm_address_t *) buf, buflen);
}

/* Implement proc_getprocenv as described in <hurd/process.defs>. */
kern_return_t
S_proc_getprocenv (struct proc *callerp,
		   pid_t pid,
		   data_t *buf,
		   mach_msg_type_number_t *buflen)
{
  struct proc *p = pid_find (pid);

  /* No need to check CALLERP here; we don't use it. */

  if (!p)
    return ESRCH;

  if (namespace_is_subprocess (p))
    {
      /* Relay it to the Subhurd's proc server (if any).  */
      error_t err;
      pid_t pid_sub;

      /* Release global lock while talking to the other proc server.  */
      pthread_mutex_unlock (&global_lock);

      err = proc_task2pid (p->p_task_namespace, p->p_task, &pid_sub);
      if (! err)
	err = proc_getprocenv (p->p_task_namespace, pid_sub, buf, buflen);

      pthread_mutex_lock (&global_lock);

      if (! err)
	return 0;

      /* Fallback.  */
    }

  return get_string_array (p->p_task, p->p_envp, (vm_address_t *)buf, buflen);
}

/* Handy abbreviation for all the various thread details.  */
#define PI_FETCH_THREAD_DETAILS  \
  (PI_FETCH_THREAD_SCHED | PI_FETCH_THREAD_BASIC | PI_FETCH_THREAD_WAITS)

/* Implement proc_getprocinfo as described in <hurd/process.defs>. */
kern_return_t
S_proc_getprocinfo (struct proc *callerp,
		    pid_t pid,
		    int *flags,
		    int **piarray,
		    mach_msg_type_number_t *piarraylen,
		    data_t *waits, mach_msg_type_number_t *waits_len)
{
  struct proc *p = pid_find (pid);
  struct procinfo *pi;
  mach_msg_type_number_t nthreads;
  thread_t *thds;
  error_t err = 0;
  size_t structsize;
  int i;
  int pi_alloced = 0, waits_alloced = 0;
  /* The amount of WAITS we've filled in so far.  */
  mach_msg_type_number_t waits_used = 0;
  mach_msg_type_number_t tkcount, thcount;
  struct proc *tp;
  task_t task;			/* P's task port.  */
  mach_port_t msgport;		/* P's msgport, or MACH_PORT_NULL if none.  */
  int owned;

  /* No need to check CALLERP here; we don't use it. */

  if (!p)
    return ESRCH;

  if (namespace_is_subprocess (p))
    {
      /* Relay it to the Subhurd's proc server (if any).  */
      error_t err;
      pid_t pid_sub;

      /* Release global lock while talking to the other proc server.  */
      pthread_mutex_unlock (&global_lock);

      err = proc_task2pid (p->p_task_namespace, p->p_task, &pid_sub);
      if (! err)
	err = proc_getprocinfo (p->p_task_namespace, pid_sub, flags,
				piarray, piarraylen, waits, waits_len);

      if (! err && *piarray && *piarraylen * sizeof (int) >= sizeof *pi)
	{
	  /* Fixup the PIDs to refer to this Hurd's processes.  */
	  task_t t_ppid = MACH_PORT_NULL;
	  task_t t_pgrp = MACH_PORT_NULL;
	  task_t t_session = MACH_PORT_NULL;
	  task_t t_logincollection = MACH_PORT_NULL;

	  pi = (struct procinfo *) *piarray;

	  /* We handle errors by checking each returned task.  */
	  if (pi->ppid != pid_sub)
	    proc_pid2task (p->p_task_namespace, pi->ppid, &t_ppid);
	  proc_pid2task (p->p_task_namespace, pi->pgrp, &t_pgrp);
	  proc_pid2task (p->p_task_namespace, pi->session, &t_session);
	  proc_pid2task (p->p_task_namespace, pi->logincollection,
			 &t_logincollection);

	  /* Reacquire the global lock for the hash table lookups.  */
	  pthread_mutex_lock (&global_lock);

	  if (MACH_PORT_VALID (t_ppid))
	    {
	      struct proc *q = task_find (t_ppid);
	      pi->ppid = q ? q->p_pid : (pid_t) -1;
	      mach_port_deallocate (mach_task_self (), t_ppid);
	    }
	  else
	    {
	      /* Either the pid2task lookup failed, or this process is
		 a root of a process hierarchy in the Subhurd.  Either
		 way, we attach it to the creator of the task
		 namespace.  */
	      pi->ppid = namespace_find_root (p)->p_pid;
	    }
	  if (MACH_PORT_VALID (t_pgrp))
	    {
	      struct proc *q = task_find (t_pgrp);
	      pi->pgrp = q ? q->p_pid : (pid_t) -1;
	      mach_port_deallocate (mach_task_self (), t_pgrp);
	    }
	  if (MACH_PORT_VALID (t_session))
	    {
	      struct proc *q = task_find (t_session);
	      pi->session = q ? q->p_pid : (pid_t) -1;
	      mach_port_deallocate (mach_task_self (), t_session);
	    }
	  if (MACH_PORT_VALID (t_logincollection))
	    {
	      struct proc *q = task_find (t_logincollection);
	      pi->logincollection = q ? q->p_pid : (pid_t) -1;
	      mach_port_deallocate (mach_task_self (), t_logincollection);
	    }

	  return 0;
	}

      pthread_mutex_lock (&global_lock);
      err = 0;
      /* Fallback.  */
    }

  task = p->p_task;

  check_msgport_death (p);
  msgport = p->p_msgport;

  if (*flags & PI_FETCH_THREAD_DETAILS)
    *flags |= PI_FETCH_THREADS;

  if (*flags & PI_FETCH_THREADS)
    {
      err = task_threads (p->p_task, &thds, &nthreads);
      if (err == MACH_SEND_INVALID_DEST)
	err = ESRCH;
      if (err)
	return err;
    }
  else
    nthreads = 0;

  structsize = sizeof (struct procinfo);
  if (*flags & PI_FETCH_THREAD_DETAILS)
    structsize += nthreads * sizeof (pi->threadinfos[0]);

  if (structsize / sizeof (int) > *piarraylen)
    {
      *piarray = mmap (0, structsize, PROT_READ|PROT_WRITE, MAP_ANON, 0, 0);
      if (*piarray == MAP_FAILED)
	{
	  err = errno;
	  if (*flags & PI_FETCH_THREADS)
	    {
	      for (i = 0; i < nthreads; i++)
		mach_port_deallocate (mach_task_self (), thds[i]);
	      munmap (thds, nthreads * sizeof (thread_t));
	    }
	  return err;
	}
      pi_alloced = 1;
    }
  *piarraylen = structsize / sizeof (int);
  pi = (struct procinfo *) *piarray;

  owned = p->p_id && p->p_id->i_nuids;

  pi->state =
    ((p->p_stopped ? PI_STOPPED : 0)
     | (p->p_exec ? PI_EXECED : 0)
     | (p->p_waiting ? PI_WAITING : 0)
     | (!p->p_pgrp->pg_orphcnt ? PI_ORPHAN : 0)
     | (p->p_msgport == MACH_PORT_NULL ? PI_NOMSG : 0)
     | (p->p_pgrp->pg_session->s_sid == p->p_pid ? PI_SESSLD : 0)
     | (owned ? 0 : PI_NOTOWNED)
     | (!p->p_parentset ? PI_NOPARENT : 0)
     | (p->p_traced ? PI_TRACED : 0)
     | (p->p_msgportwait ? PI_GETMSG : 0)
     | (p->p_loginleader ? PI_LOGINLD : 0));
  pi->owner = owned ? p->p_id->i_uids[0] : 0;
  pi->ppid = p->p_parent->p_pid;
  pi->pgrp = p->p_pgrp->pg_pgid;
  pi->session = p->p_pgrp->pg_session->s_sid;
  for (tp = p; !tp->p_loginleader; tp = tp->p_parent)
    assert_backtrace (tp);
  pi->logincollection = tp->p_pid;
  if (p->p_dead || p->p_stopped)
    {
      pi->exitstatus = p->p_status;
      pi->sigcode = p->p_sigcode;
    }
  else
    pi->exitstatus = pi->sigcode = 0;

  pi->nthreads = nthreads;

  /* Release GLOBAL_LOCK around time consuming bits, and more importatantly,
     potential calls to P's msgport, which can block.  */
  pthread_mutex_unlock (&global_lock);

  if (*flags & PI_FETCH_TASKINFO)
    {
      tkcount = TASK_BASIC_INFO_COUNT;
      err = task_info (task, TASK_BASIC_INFO,
		       (task_info_t) &pi->taskinfo, &tkcount);
      if (err == MACH_SEND_INVALID_DEST)
	err = ESRCH;
#ifdef TASK_SCHED_TIMESHARE_INFO
      if (!err)
	{
	  tkcount = TASK_SCHED_TIMESHARE_INFO_COUNT;
	  err = task_info (task, TASK_SCHED_TIMESHARE_INFO,
			   (int *)&pi->timeshare_base_info, &tkcount);
	  if (err == KERN_INVALID_POLICY)
	    {
	      pi->timeshare_base_info.base_priority = -1;
	      err = 0;
	    }
	}
#endif
    }
  if (*flags & PI_FETCH_TASKEVENTS)
    {
      tkcount = TASK_EVENTS_INFO_COUNT;
      err = task_info (task, TASK_EVENTS_INFO,
		       (task_info_t) &pi->taskevents, &tkcount);
      if (err == MACH_SEND_INVALID_DEST)
	err = ESRCH;
      if (err)
	{
	  /* Something screwy, give up on this bit of info.  */
	  *flags &= ~PI_FETCH_TASKEVENTS;
	  err = 0;
	}
    }

  for (i = 0; i < nthreads; i++)
    {
      if (*flags & PI_FETCH_THREAD_DETAILS)
	pi->threadinfos[i].died = 0;
      if (*flags & PI_FETCH_THREAD_BASIC)
	{
	  thcount = THREAD_BASIC_INFO_COUNT;
	  err = thread_info (thds[i], THREAD_BASIC_INFO,
			     (thread_info_t) &pi->threadinfos[i].pis_bi,
			     &thcount);
	  if (err == MACH_SEND_INVALID_DEST)
	    {
	      pi->threadinfos[i].died = 1;
	      err = 0;
	      continue;
	    }
	  else if (err)
	    /* Something screwy, give up on this bit of info.  */
	    {
	      *flags &= ~PI_FETCH_THREAD_BASIC;
	      err = 0;
	    }
	}

      if (*flags & PI_FETCH_THREAD_SCHED)
	{
	  thcount = THREAD_SCHED_INFO_COUNT;
	  err = thread_info (thds[i], THREAD_SCHED_INFO,
			     (thread_info_t) &pi->threadinfos[i].pis_si,
			     &thcount);

#ifdef HAVE_STRUCT_THREAD_SCHED_INFO_LAST_PROCESSOR
	  if (err == 0)
	    /* If the structure read doesn't include last_processor field, assume
	       CPU 0.  */
	    if (thcount < 8)
	      pi->threadinfos[i].pis_si.last_processor = 0;
#endif

	  if (err == MACH_SEND_INVALID_DEST)
	    {
	      pi->threadinfos[i].died = 1;
	      err = 0;
	      continue;
	    }
	  if (err)
	    /* Something screwy, give up on this bit of info.  */
	    {
	      *flags &= ~PI_FETCH_THREAD_SCHED;
	      err = 0;
	    }

	}

      /* Note that there are thread wait entries only for those threads
         not marked dead.  */

      if (*flags & PI_FETCH_THREAD_WAITS)
	{
	  /* See what thread I is waiting on.  */
	  if (msgport == MACH_PORT_NULL)
	    *flags &= ~PI_FETCH_THREAD_WAITS; /* Can't return much... */
	  else
	    {
	      string_t desc;
	      size_t desc_len;

	      if (msg_report_wait (msgport, thds[i],
				   desc, &pi->threadinfos[i].rpc_block))
		desc[0] = '\0'; /* Don't know.  */

	      /* See how long DESC is, being sure not to barf if it's
		 unterminated (string_t's are fixed length).  */
	      desc_len = strnlen (desc, sizeof desc);

	      if (waits_used + desc_len + 1 > *waits_len)
		/* Not enough room in WAITS, we must allocate more.  */
		{
		  char *new_waits = 0;
		  mach_msg_type_number_t new_len =
		    round_page (waits_used + desc_len + 1);

		  new_waits = mmap (0, new_len, PROT_READ|PROT_WRITE,
				    MAP_ANON, 0, 0);
		  err = (new_waits == MAP_FAILED) ? errno : 0;
		  if (err)
		    /* Just don't return any more waits information.  */
		    *flags &= ~PI_FETCH_THREAD_WAITS;
		  else
		    {
		      if (waits_used > 0)
			memcpy (new_waits, *waits, waits_used);
		      if (*waits_len > 0 && waits_alloced)
			munmap (*waits, *waits_len);
		      *waits = new_waits;
		      *waits_len = new_len;
		      waits_alloced = 1;
		    }
		}

	      if (waits_used + desc_len + 1 <= *waits_len)
		/* Append DESC to WAITS.  */
		{
		  memcpy (*waits + waits_used, desc, desc_len);
		  waits_used += desc_len;
		  (*waits)[waits_used++] = '\0';
		}
	    }
	}

      mach_port_deallocate (mach_task_self (), thds[i]);
    }

  if (*flags & PI_FETCH_THREADS)
    munmap (thds, nthreads * sizeof (thread_t));
  if (err && pi_alloced)
    munmap (*piarray, structsize);
  if (err && waits_alloced)
    munmap (*waits, *waits_len);
  else
    *waits_len = waits_used;

  /* Reacquire GLOBAL_LOCK to make the central locking code happy.  */
  pthread_mutex_lock (&global_lock);

  return err;
}

/* Implement proc_make_login_coll as described in <hurd/process.defs>. */
kern_return_t
S_proc_make_login_coll (struct proc *p)
{
  if (!p)
    return EOPNOTSUPP;
  p->p_loginleader = 1;
  return 0;
}

/* Implement proc_getloginid as described in <hurd/process.defs>. */
kern_return_t
S_proc_getloginid (struct proc *callerp,
		   pid_t pid,
		   pid_t *leader)
{
  struct proc *proc = pid_find (pid);
  struct proc *p = proc;

  /* No need to check CALLERP here; we don't use it. */

  if (!proc)
    return ESRCH;

  if (namespace_is_subprocess (p))
    {
      /* Relay it to the Subhurd's proc server (if any).  */
      error_t err;
      pid_t pid_sub;

      /* Release global lock while talking to the other proc server.  */
      pthread_mutex_unlock (&global_lock);

      err = proc_task2pid (p->p_task_namespace, p->p_task, &pid_sub);
      if (! err)
	err = proc_getloginid (p->p_task_namespace, pid_sub, leader);
      if (! err)
	/* Acquires global_lock.  */
	err = namespace_translate_pids (p->p_task_namespace, leader, 1);
      else
	pthread_mutex_lock (&global_lock);

      if (! err)
	return 0;

      /* Fallback.  */
    }

  for (p = proc; !p->p_loginleader; p = p->p_parent)
    assert_backtrace (p);

  *leader = p->p_pid;
  return 0;
}

/* Implement proc_getloginpids as described in <hurd/process.defs>. */
kern_return_t
S_proc_getloginpids (struct proc *callerp,
		     pid_t id,
		     pid_t **pids,
		     mach_msg_type_number_t *npids)
{
  error_t err = 0;
  struct proc *l = pid_find (id);
  struct proc *p;
  struct proc **tail, **new, **parray;
  int parraysize;
  int i;

  /* No need to check CALLERP here; we don't use it. */

  if (!l)
    return ESRCH;

  if (namespace_is_subprocess (l))
    {
      /* Relay it to the Subhurd's proc server (if any).  */
      error_t err;
      pid_t pid_sub;

      /* Release global lock while talking to the other proc server.  */
      pthread_mutex_unlock (&global_lock);

      err = proc_task2pid (l->p_task_namespace, l->p_task, &pid_sub);
      if (! err)
	err = proc_getloginpids (l->p_task_namespace, pid_sub, pids, npids);
      if (! err)
	/* Acquires global_lock.  */
	err = namespace_translate_pids (l->p_task_namespace, *pids, *npids);
      else
	pthread_mutex_lock (&global_lock);

      if (! err)
	return 0;

      /* Fallback.  */
    }

  if (!l || !l->p_loginleader)
    return ESRCH;

  /* Simple breadth first search of the children of L. */
  parraysize = 50;
  parray = malloc (sizeof (struct proc *) * parraysize);
  if (! parray)
    return ENOMEM;

  parray[0] = l;
  for (tail = parray, new = &parray[1]; tail != new; tail++)
    {
      for (p = (*tail)->p_ochild; p; p = p->p_sib)
	if (!p->p_loginleader)
	  {
	    /* Add P to the list at NEW */
	    if (new - parray > parraysize)
	      {
		struct proc **newparray;
		ptrdiff_t tail_offset = tail - parray;
		ptrdiff_t new_offset = new - parray;
		newparray = realloc (parray, ((parraysize *= 2)
					      * sizeof (struct proc *)));
		if (! newparray)
		  {
		    free (parray);
		    return ENOMEM;
		  }

		tail = newparray + tail_offset;
		new = newparray + new_offset;
		parray = newparray;
	      }
	    *new++ = p;
	  }
    }

  if (*npids < new - parray)
    {
      *pids = mmap (0, (new - parray) * sizeof (pid_t), PROT_READ|PROT_WRITE,
		    MAP_ANON, 0, 0);
      if (*pids == MAP_FAILED)
        err = errno;
    }

  if (! err)
    {
      *npids = new - parray;
      for (i = 0; i < *npids; i++)
        (*pids)[i] = parray[i]->p_pid;
    }

  free (parray);
  return err;
}

/* Implement proc_setlogin as described in <hurd/process.defs>. */
kern_return_t
S_proc_setlogin (struct proc *p,
	         const_string_t login)
{
  struct login *l;

  if (!p)
    return EOPNOTSUPP;

  if (!check_uid (p, 0))
    return EPERM;

  l = malloc (sizeof (struct login) + strlen (login) + 1);
  if (! l)
    return ENOMEM;

  l->l_refcnt = 1;
  strcpy (l->l_name, login);
  if (!--p->p_login->l_refcnt)
    free (p->p_login);
  p->p_login = l;
  return 0;
}

/* Implement proc_getlogin as described in <hurd/process.defs>. */
kern_return_t
S_proc_getlogin (struct proc *p,
	         string_t login)
{
  if (!p)
    return EOPNOTSUPP;
  strcpy (login, p->p_login->l_name);
  return 0;
}

/* Implement proc_get_tty as described in <hurd/process.defs>. */
kern_return_t
S_proc_get_tty (struct proc *p, pid_t pid,
		mach_port_t *tty, mach_msg_type_name_t *tty_type)
{
  return EOPNOTSUPP;		/* XXX */
}

/* Implement proc_getnports as described in <hurd/process.defs>. */
kern_return_t
S_proc_getnports (struct proc *callerp,
		    pid_t pid,
		    mach_msg_type_number_t *nports)
{
  struct proc *p = pid_find (pid);
  mach_port_array_t names;
  mach_msg_type_number_t ncount;
  mach_port_type_array_t types;
  mach_msg_type_number_t tcount;
  error_t err = 0;

  /* No need to check CALLERP here; we don't use it. */

  if (!p)
    return ESRCH;

  err = mach_port_names (p->p_task, &names, &ncount, &types, &tcount);
  if (err == KERN_INVALID_TASK)
    err = ESRCH;

  if (!err) {
    *nports = ncount;

    munmap (names, ncount * sizeof (mach_port_t));
    munmap (types, tcount * sizeof (mach_port_type_t));
  }

  return err;
}

/* Implement proc_set_path as described in <hurd/process.defs>. */
kern_return_t
S_proc_set_exe (struct proc *p,
	        const_string_t path)
{
  char *copy;

  if (!p)
    return EOPNOTSUPP;

  copy = strdup(path);
  if (! copy)
    return ENOMEM;

  free(p->exe);
  p->exe = copy;
  return 0;
}

/* Implement proc_get_path as described in <hurd/process.defs>. */
kern_return_t
S_proc_get_exe (struct proc *callerp,
		pid_t pid,
		string_t path)
{
  struct proc *p = pid_find (pid);

  /* No need to check CALLERP here; we don't use it. */

  if (!p)
    return ESRCH;

  if (p->exe)
    snprintf (path, 1024 /* XXX */, "%s", p->exe);
  else
    path[0] = 0;
  return 0;
}