1999-11-18 Roland McGrath <roland@baalperazim.frob.com>

        * hurd/hurdsig.c (_hurdsig_init): If __hurd_threadvar_stack_mask is
        nonzero, use cthread_fork to create the signal thread.
        * hurd/msgportdemux.c (_hurd_msgport_receive): Initialize
        _hurd_msgport_thread here (to self).
        * sysdeps/mach/hurd/fork.c (__fork): When __hurd_sigthread_stack_end
        is zero, instead compute child signal thread's starting SP from parent
        signal thread's current SP and the threadvar_stack variables.
        * hurd/Versions (GLIBC_2.1.3): Add cthread_fork, cthread_detach.
        These are now referenced weakly by _hurdsig_init.

        * hurd/report-wait.c (_S_msg_report_wait): Fix typo:
        &_hurd_itimer_thread not &_hurd_msgport_thread.

1999-10-01  Roland McGrath  <roland@baalperazim.frob.com>

        * hurd/hurdfchdir.c (_hurd_change_directory_port_from_fd): Rewrite
        without HURD_DPORT_USE to clean up warnings.
        * hurd/dtable.c (get_dtable_port): Likewise.

        * hurd/hurdioctl.c (rectty_dtable): Renamed to install_ctty.
        (install_ctty): Do the changing of the cttyid port cell here, inside
        the critical section while we holding the dtable lock.
        (_hurd_setcttyid, tiocsctty, tiocnotty): Use that instead of changing
        the port cell and calling rectty_dtable.
        (_hurd_locked_install_cttyid): New function, split out of install_ctty.
        (install_ctty): Use it inside a critical section, with the lock held.
        * sysdeps/mach/hurd/setsid.c (__setsid): Use
        _hurd_locked_install_cttyid to effect the cttyid and dtable changes
        after proc_setsid, having held the dtable lock throughout.
        * hurd/dtable.c (ctty_new_pgrp): With the dtable lock held, check the
        cttyid port for null and bail out early if so.  The dtable lock
        serializes us after any cttyid change and its associated dtable update.

1 files changed, 67 insertions, 36 deletions

diff --git a/hurd/dtable.c b/hurd/dtable.c
index 30f6a5e..f3eb88f 100644
--- a/hurd/dtable.c
+++ b/hurd/dtable.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1991, 92, 93, 94, 95, 96, 97 Free Software Foundation, Inc.
+/* Copyright (C) 1991,92,93,94,95,96,97,99 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
@@ -107,18 +107,35 @@ text_set_element (_hurd_subinit, init_dtable);
 static file_t
 get_dtable_port (int fd)
 {
+  struct hurd_fd *d = _hurd_fd_get (fd);
   file_t dport;
-  int err = HURD_DPORT_USE (fd, __mach_port_mod_refs (__mach_task_self (),
-						      (dport = port),
-						      MACH_PORT_RIGHT_SEND,
-						      1));
-  if (err)
-    {
-      errno = err;
-      return MACH_PORT_NULL;
-    }
-  else
-    return dport;
+
+  if (!d)
+    return __hurd_fail (EBADF), MACH_PORT_NULL;
+
+  HURD_CRITICAL_BEGIN;
+
+  dport = HURD_PORT_USE (&d->port,
+			 ({
+			   error_t err;
+			   mach_port_t outport;
+			   err = __mach_port_mod_refs (__mach_task_self (),
+						       port,
+						       MACH_PORT_RIGHT_SEND,
+						       1);
+			   if (err)
+			     {
+			       errno = err;
+			       outport = MACH_PORT_NULL;
+			     }
+			   else
+			     outport = port;
+			   outport;
+			 }));
+
+  HURD_CRITICAL_END;
+
+  return dport;
 }
 
 file_t (*_hurd_getdport_fn) (int fd) = get_dtable_port;
@@ -176,32 +193,46 @@ ctty_new_pgrp (void)
   HURD_CRITICAL_BEGIN;
   __mutex_lock (&_hurd_dtable_lock);
 
-  for (i = 0; i < _hurd_dtablesize; ++i)
+  if (__USEPORT (CTTYID, port == MACH_PORT_NULL))
     {
-      struct hurd_fd *const d = _hurd_dtable[i];
-      struct hurd_userlink ulink, ctty_ulink;
-      io_t port, ctty;
-
-      if (d == NULL)
-	/* Nothing to do for an unused descriptor cell.  */
-	continue;
-
-      port = _hurd_port_get (&d->port, &ulink);
-      ctty = _hurd_port_get (&d->ctty, &ctty_ulink);
-
-      if (ctty != MACH_PORT_NULL)
-	{
-	  /* This fd has a ctty-special port.  We need a new one, to tell
-             the io server of our different process group.  */
-	  io_t new;
-	  if (__term_open_ctty (port, _hurd_pid, _hurd_pgrp, &new))
-	    new = MACH_PORT_NULL;
-	  _hurd_port_set (&d->ctty, new);
-	}
-
-      _hurd_port_free (&d->port, &ulink, port);
-      _hurd_port_free (&d->ctty, &ctty_ulink, ctty);
+      /* We have no controlling terminal.  If we haven't had one recently,
+	 but our pgrp is being pointlessly diddled anyway, then we will
+	 have nothing to do in the loop below because no fd will have a
+	 ctty port at all.
+
+	 More likely, a setsid call is responsible both for the change
+	 in pgrp and for clearing the cttyid port.  In that case, setsid
+	 held the dtable lock while updating the dtable to clear all the
+	 ctty ports, and ergo must have finished doing so before we run here.
+	 So we can be sure, again, that the loop below has no work to do.  */
     }
+  else
+    for (i = 0; i < _hurd_dtablesize; ++i)
+      {
+	struct hurd_fd *const d = _hurd_dtable[i];
+	struct hurd_userlink ulink, ctty_ulink;
+	io_t port, ctty;
+
+	if (d == NULL)
+	  /* Nothing to do for an unused descriptor cell.  */
+	  continue;
+
+	port = _hurd_port_get (&d->port, &ulink);
+	ctty = _hurd_port_get (&d->ctty, &ctty_ulink);
+
+	if (ctty != MACH_PORT_NULL)
+	  {
+	    /* This fd has a ctty-special port.  We need a new one, to tell
+	       the io server of our different process group.  */
+	    io_t new;
+	    if (__term_open_ctty (port, _hurd_pid, _hurd_pgrp, &new))
+	      new = MACH_PORT_NULL;
+	    _hurd_port_set (&d->ctty, new);
+	  }
+
+	_hurd_port_free (&d->port, &ulink, port);
+	_hurd_port_free (&d->ctty, &ctty_ulink, ctty);
+      }
 
   __mutex_unlock (&_hurd_dtable_lock);
   HURD_CRITICAL_END;