initial import

1 files changed, 259 insertions, 0 deletions

diff --git a/hurd/hurdexec.c b/hurd/hurdexec.c
new file mode 100644
index 0000000000..d5d2d080e4
--- /dev/null
+++ b/hurd/hurdexec.c
@@ -0,0 +1,259 @@
+/* Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library 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.
+
+The GNU C Library 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.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+#include <hurd.h>
+#include <hurd/fd.h>
+#include <hurd/signal.h>
+
+/* Overlay TASK, executing FILE with arguments ARGV and environment ENVP.
+   If TASK == mach_task_self (), some ports are dealloc'd by the exec server.
+   ARGV and ENVP are terminated by NULL pointers.  */
+error_t
+_hurd_exec (task_t task, file_t file, 
+	    char *const argv[], char *const envp[])
+{
+  error_t err;
+  char *args, *env, *ap;
+  size_t argslen, envlen;
+  int ints[INIT_INT_MAX];
+  mach_port_t ports[_hurd_nports];
+  struct hurd_userlink ulink_ports[_hurd_nports];
+  file_t *dtable;
+  int dtablesize;
+  struct hurd_port **dtable_cells;
+  struct hurd_userlink *ulink_dtable;
+  int i;
+  char *const *p;
+  struct hurd_sigstate *ss;
+  mach_port_t *please_dealloc, *pdp;
+
+
+  /* Pack the arguments into an array with nulls separating the elements.  */
+  argslen = 0;
+  if (argv != NULL)
+    {
+      p = argv;
+      while (*p != NULL)
+	argslen += strlen (*p++) + 1;
+      args = __alloca (argslen);
+      ap = args;
+      for (p = argv; *p != NULL; ++p)
+	ap = __memccpy (ap, *p, '\0', ULONG_MAX);
+    }
+  else
+    args = NULL;
+
+  /* Pack the environment into an array with nulls separating elements.  */
+  envlen = 0;
+  if (envp != NULL)
+    {
+      p = envp;
+      while (*p != NULL)
+	envlen += strlen (*p++) + 1;
+      env = __alloca (envlen);
+      ap = env;
+      for (p = envp; *p != NULL; ++p)
+	ap = __memccpy (ap, *p, '\0', ULONG_MAX);
+    }
+  else
+    env = NULL;
+
+  /* Load up the ports to give to the new program.  */
+  for (i = 0; i < _hurd_nports; ++i)
+    if (i == INIT_PORT_PROC && task != __mach_task_self ())
+      {
+	/* This is another task, so we need to ask the proc server
+	   for the right proc server port for it.  */
+	if (err = __USEPORT (PROC, __proc_task2proc (port, task, &ports[i])))
+	  {
+	    while (--i > 0)
+	      _hurd_port_free (&_hurd_ports[i], &ulink_ports[i], ports[i]);
+	    return err;
+	  }
+      }
+    else
+      ports[i] = _hurd_port_get (&_hurd_ports[i], &ulink_ports[i]);
+
+
+  /* Load up the ints to give the new program.  */
+  for (i = 0; i < INIT_INT_MAX; ++i)
+    switch (i)
+      {
+      case INIT_UMASK:
+	ints[i] = _hurd_umask;
+	break;
+
+      case INIT_SIGMASK:
+      case INIT_SIGIGN:
+      case INIT_SIGPENDING:
+	/* We will set these all below.  */
+	break;
+
+      default:
+	ints[i] = 0;
+      }
+
+  ss = _hurd_self_sigstate ();
+  __spin_lock (&ss->lock);
+  ints[INIT_SIGMASK] = ss->blocked;
+  ints[INIT_SIGPENDING] = ss->pending;
+  ints[INIT_SIGIGN] = 0;
+  for (i = 1; i < NSIG; ++i)
+    if (ss->actions[i].sa_handler == SIG_IGN)
+      ints[INIT_SIGIGN] |= __sigmask (i);
+
+  /* We hold the sigstate lock until the exec has failed so that no signal
+     can arrive between when we pack the blocked and ignored signals, and
+     when the exec actually happens.  A signal handler could change what
+     signals are blocked and ignored.  Either the change will be reflected
+     in the exec, or the signal will never be delivered.  Setting the
+     critical section flag avoids anything we call trying to acquire the
+     sigstate lock.  */
+  
+  ss->critical_section = 1;
+  __spin_unlock (&ss->lock);
+
+  /* Pack up the descriptor table to give the new program.  */
+  __mutex_lock (&_hurd_dtable_lock);
+
+  dtablesize = _hurd_dtable ? _hurd_dtablesize : _hurd_init_dtablesize;
+
+  if (task == __mach_task_self ())
+    /* Request the exec server to deallocate some ports from us if the exec
+       succeeds.  The init ports and descriptor ports will arrive in the
+       new program's exec_startup message.  If we failed to deallocate
+       them, the new program would have duplicate user references for them.
+       But we cannot deallocate them ourselves, because we must still have
+       them after a failed exec call.  */
+    please_dealloc = __alloca ((_hurd_nports + (2 * dtablesize))
+				* sizeof (mach_port_t));
+  else
+    please_dealloc = NULL;
+  pdp = please_dealloc;
+
+  if (_hurd_dtable != NULL)
+    {
+      dtable = __alloca (dtablesize * sizeof (dtable[0]));
+      ulink_dtable = __alloca (dtablesize * sizeof (ulink_dtable[0]));
+      dtable_cells = __alloca (dtablesize * sizeof (dtable_cells[0]));
+      for (i = 0; i < dtablesize; ++i)
+	{
+	  struct hurd_fd *const d = _hurd_dtable[i];
+	  if (d == NULL)
+	    {
+	      dtable[i] = MACH_PORT_NULL;
+	      continue;
+	    }
+	  __spin_lock (&d->port.lock);
+	  if (d->flags & FD_CLOEXEC)
+	    {
+	      /* This descriptor is marked to be closed on exec.
+		 So don't pass it to the new program.  */
+	      dtable[i] = MACH_PORT_NULL;
+	      if (pdp && d->port.port != MACH_PORT_NULL)
+		{
+		  /* We still need to deallocate the ports.  */
+		  *pdp++ = d->port.port;
+		  if (d->ctty.port != MACH_PORT_NULL)
+		    *pdp++ = d->ctty.port;
+		}
+	      __spin_unlock (&d->port.lock);
+	    }
+	  else
+	    {
+	      if (pdp && d->ctty.port != MACH_PORT_NULL)
+		/* All the elements of DTABLE are added to PLEASE_DEALLOC
+		   below, so we needn't add the port itself.
+		   But we must deallocate the ctty port as well as
+		   the normal port that got installed in DTABLE[I].  */
+		*pdp++ = d->ctty.port;
+	      dtable[i] = _hurd_port_locked_get (&d->port, &ulink_dtable[i]);
+	      dtable_cells[i] = &d->port;
+	    }
+	}
+    }
+  else
+    {
+      dtable = _hurd_init_dtable;
+      ulink_dtable = NULL;
+      dtable_cells = NULL;
+    }
+
+  /* The information is all set up now.  Try to exec the file.  */
+
+  {
+    if (pdp)
+      {
+	/* Request the exec server to deallocate some ports from us if the exec
+	   succeeds.  The init ports and descriptor ports will arrive in the
+	   new program's exec_startup message.  If we failed to deallocate
+	   them, the new program would have duplicate user references for them.
+	   But we cannot deallocate them ourselves, because we must still have
+	   them after a failed exec call.  */
+
+	for (i = 0; i < _hurd_nports; ++i)
+	  *pdp++ = ports[i];
+	for (i = 0; i < dtablesize; ++i)
+	  *pdp++ = dtable[i];
+      }
+
+    err = __file_exec (file, task,
+		       _hurd_exec_flags & EXEC_INHERITED,
+		       args, argslen, env, envlen,
+		       dtable, MACH_MSG_TYPE_COPY_SEND, dtablesize, 
+		       ports, MACH_MSG_TYPE_COPY_SEND, _hurd_nports, 
+		       ints, INIT_INT_MAX,
+		       please_dealloc, pdp - please_dealloc,
+		       NULL, 0);
+  }
+
+  /* Release references to the standard ports.  */
+  for (i = 0; i < _hurd_nports; ++i)
+    if (i == INIT_PORT_PROC && task != __mach_task_self ())
+      __mach_port_deallocate (__mach_task_self (), ports[i]);
+    else
+      _hurd_port_free (&_hurd_ports[i], &ulink_ports[i], ports[i]);
+
+  if (ulink_dtable != NULL)
+    /* Release references to the file descriptor ports.  */
+    for (i = 0; i < dtablesize; ++i)
+      if (dtable[i] != MACH_PORT_NULL)
+	_hurd_port_free (dtable_cells[i], &ulink_dtable[i], dtable[i]);
+
+  /* Release lock on the file descriptor table. */
+  __mutex_unlock (&_hurd_dtable_lock);
+
+  /* Safe to let signals happen now.  */
+  {
+    sigset_t pending;
+    __spin_lock (&ss->lock);
+    ss->critical_section = 0;
+    pending = ss->pending & ~ss->blocked;
+    __spin_unlock (&ss->lock);
+    if (pending)
+      __msg_sig_post (_hurd_msgport, 0, __mach_task_self ());
+  }
+
+  return err;
+}