initial import

8 files changed, 1153 insertions, 0 deletions

diff --git a/hurd/hurd/fd.h b/hurd/hurd/fd.h
new file mode 100644
index 0000000000..4747c785a5
--- /dev/null
+++ b/hurd/hurd/fd.h
@@ -0,0 +1,222 @@
+/* File descriptors.
+Copyright (C) 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.  */
+
+#ifndef	_HURD_FD_H
+
+#define	_HURD_FD_H	1
+#include <features.h>
+
+#include <hurd/hurd_types.h>
+#include <hurd/port.h>
+
+
+/* Structure representing a file descriptor.  */
+
+struct hurd_fd
+  {
+    struct hurd_port port;	/* io server port.  */
+    int flags;			/* fcntl flags; locked by port.lock.  */
+
+    /* Normal port to the ctty.  When `port' is our ctty, this is a port to
+       the same io object but which never returns EBACKGROUND; when not,
+       this is nil.  */
+    struct hurd_port ctty;
+  };
+
+
+/* Current file descriptor table.  */
+
+extern int _hurd_dtablesize;
+extern struct hurd_fd **_hurd_dtable;
+extern struct mutex _hurd_dtable_lock; /* Locks those two variables.  */
+
+#include <hurd/signal.h>
+#include <lock-intern.h>
+
+#ifndef _EXTERN_INLINE
+#define _EXTERN_INLINE extern __inline
+#endif
+
+/* Returns the descriptor cell for FD.  If FD is invalid or unused, return
+   NULL.  The cell is unlocked; when ready to use it, lock it and check for
+   it being unused.  */
+
+_EXTERN_INLINE struct hurd_fd *
+_hurd_fd_get (int fd)
+{
+  struct hurd_fd *descriptor;
+
+  __mutex_lock (&_hurd_dtable_lock);
+  if (fd < 0 || fd >= _hurd_dtablesize)
+    descriptor = NULL;
+  else
+    {
+      struct hurd_fd *cell = _hurd_dtable[fd];
+      if (cell == NULL)
+	/* No descriptor allocated at this index.  */
+	descriptor = NULL;
+      else
+	{
+	  __spin_lock (&cell->port.lock);
+	  if (cell->port.port == MACH_PORT_NULL)
+	    /* The descriptor at this index has no port in it.
+	       This happens if it existed before but was closed.  */
+	    descriptor = NULL;
+	  else
+	    descriptor = cell;
+	  __spin_unlock (&cell->port.lock);
+	}
+    }
+  __mutex_unlock (&_hurd_dtable_lock);
+
+  return descriptor;
+}
+
+
+/* Evaluate EXPR with the variable `descriptor' bound to a pointer to the
+   file descriptor structure for FD.   */
+
+#define	HURD_FD_USE(fd, expr)						      \
+  ({ struct hurd_fd *descriptor = _hurd_fd_get (fd);			      \
+     descriptor == NULL ? EBADF : (expr); })
+
+/* Evaluate EXPR with the variable `port' bound to the port to FD, and
+   `ctty' bound to the ctty port.  */
+
+#define HURD_DPORT_USE(fd, expr) \
+  HURD_FD_USE ((fd), HURD_FD_PORT_USE (descriptor, (expr)))
+
+/* Likewise, but FD is a pointer to the file descriptor structure.  */
+
+#define	HURD_FD_PORT_USE(fd, expr)					      \
+  ({ error_t __result;							      \
+     struct hurd_fd *const __d = (fd);					      \
+     struct hurd_userlink __ulink, __ctty_ulink;			      \
+     io_t port, ctty;							      \
+     void *crit = _hurd_critical_section_lock ();			      \
+     __spin_lock (&__d->port.lock);					      \
+     if (__d->port.port == MACH_PORT_NULL)				      \
+       {								      \
+	 __spin_unlock (&__d->port.lock);				      \
+	 _hurd_critical_section_unlock (crit);				      \
+	 __result = EBADF;						      \
+       }								      \
+     else								      \
+       {								      \
+	 ctty = _hurd_port_get (&__d->ctty, &__ctty_ulink);		      \
+	 port = _hurd_port_locked_get (&__d->port, &__ulink);		      \
+	 _hurd_critical_section_unlock (crit);				      \
+	 __result = (expr);						      \
+	 _hurd_port_free (&__d->port, &__ulink, port);			      \
+	 if (ctty != MACH_PORT_NULL)					      \
+	   _hurd_port_free (&__d->ctty, &__ctty_ulink, ctty);		      \
+       }								      \
+     __result; })
+
+#include <errno.h>
+
+/* Check if ERR should generate a signal.
+   Returns the signal to take, or zero if none.  */
+
+_EXTERN_INLINE error_t
+_hurd_fd_error_signal (error_t err)
+{
+  switch (err)
+    {
+    case EMACH_SEND_INVALID_DEST:
+    case EMIG_SERVER_DIED:
+      /* The server has disappeared!  */
+      return SIGLOST;
+    case EPIPE:
+      return SIGPIPE;
+    default:
+      /* Having a default case avoids -Wenum-switch warnings.  */
+      return 0;
+    }
+}
+
+/* Handle an error from an RPC on a file descriptor's port.  You should
+   always use this function to handle errors from RPCs made on file
+   descriptor ports.  Some errors are translated into signals.  */   
+
+_EXTERN_INLINE error_t
+_hurd_fd_error (int fd, error_t err)
+{
+  int signo = _hurd_fd_error_signal (err);
+  if (signo)
+    _hurd_raise_signal (NULL, signo, fd, err);
+  return err;
+}
+
+/* Handle error code ERR from an RPC on file descriptor FD's port.
+   Set `errno' to the appropriate error code, and always return -1.  */
+
+_EXTERN_INLINE int
+__hurd_dfail (int fd, error_t err)
+{
+  errno = _hurd_fd_error (fd, err);
+  return -1;
+}
+
+/* Set up *FD to have PORT its server port, doing appropriate ctty magic.
+   Does no locking or unlocking.  */
+
+extern void _hurd_port2fd (struct hurd_fd *fd, io_t port, int flags);
+
+/* Allocate a new file descriptor and install PORT in it (doing any
+   appropriate ctty magic); consumes a user reference on PORT.  FLAGS are
+   as for `open'; only O_IGNORE_CTTY is meaningful, but all are saved.
+
+   If the descriptor table is full, set errno, and return -1.
+   If DEALLOC is nonzero, deallocate PORT first.  */
+
+extern int _hurd_intern_fd (io_t port, int flags, int dealloc);
+
+/* Allocate a new file descriptor in the table and return it, locked.  The
+   new descriptor number will be no less than FIRST_FD.  If the table is
+   full, set errno to EMFILE and return NULL.  If FIRST_FD is negative or
+   bigger than the size of the table, set errno to EINVAL and return NULL.  */
+
+extern struct hurd_fd *_hurd_alloc_fd (int *fd_ptr, int first_fd);
+
+/* Allocate a new file descriptor structure and initialize its port cells
+   with PORT and CTTY.  (This does not affect the descriptor table.)  */
+
+extern struct hurd_fd *_hurd_new_fd (io_t port, io_t ctty);
+
+/* Close a file descriptor, making it available for future reallocation.  */
+
+extern error_t _hurd_fd_close (struct hurd_fd *fd);
+
+/* Read and write data from a file descriptor; just like `read' and `write'.
+   If successful, stores the amount actually read or written in *NBYTES.  */
+
+extern error_t _hurd_fd_read (struct hurd_fd *fd, void *buf, size_t *nbytes);
+extern error_t _hurd_fd_write (struct hurd_fd *fd,
+			       const void *buf, size_t *nbytes);
+
+
+/* Call *RPC on PORT and/or CTTY; if a call on CTTY returns EBACKGROUND,
+   generate SIGTTIN/SIGTTOU or EIO as appropriate.  */
+
+extern error_t _hurd_ctty_input (io_t port, io_t ctty, error_t (*rpc) (io_t));
+extern error_t _hurd_ctty_output (io_t port, io_t ctty, error_t (*rpc) (io_t));
+
+
+#endif	/* hurd/fd.h */
diff --git a/hurd/hurd/id.h b/hurd/hurd/id.h
new file mode 100644
index 0000000000..7a50081038
--- /dev/null
+++ b/hurd/hurd/id.h
@@ -0,0 +1,55 @@
+/* User and group IDs.
+Copyright (C) 1993, 1994 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.  */
+
+#ifndef	_HURD_ID_H
+
+#define	_HURD_ID_H	1
+#include <features.h>
+
+#include <cthreads.h>		/* For `struct mutex'.  */
+
+/* Structure describing authorization data for the process.  */
+
+struct hurd_id_data
+  {
+    struct mutex lock;
+
+    int valid;			/* If following data are up to date.  */
+
+    struct
+      {
+	uid_t *uids;
+	gid_t *gids;
+	mach_msg_type_number_t nuids, ngids;
+      } gen, aux;
+
+    auth_t rid_auth;		/* Cache used by access.  */
+  };
+
+/* Current data.  */
+
+extern struct hurd_id_data _hurd_id;
+
+
+/* Update _hurd_id (caller should be holding the lock).  */
+
+extern error_t _hurd_check_ids (void);
+
+
+#endif	/* hurd/id.h */
diff --git a/hurd/hurd/ioctl.h b/hurd/hurd/ioctl.h
new file mode 100644
index 0000000000..cc83433c17
--- /dev/null
+++ b/hurd/hurd/ioctl.h
@@ -0,0 +1,71 @@
+/* User-registered handlers for specific `ioctl' requests.
+Copyright (C) 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.  */
+
+#ifndef	_HURD_IOCTL_H
+#define	_HURD_IOCTL_H	1
+
+#define	__need___va_list
+#include <stdarg.h>
+
+
+/* Type of handler function, called like ioctl to do its entire job.  */
+typedef int (*ioctl_handler_t) (int fd, int request, void *arg);
+
+/* Structure that records an ioctl handler.  */
+struct ioctl_handler
+  {
+    int first_request, last_request; /* Range of handled request values.  */
+
+    /* Handler function, called like ioctl to do its entire job.  */
+    ioctl_handler_t handler;
+
+    struct ioctl_handler *next;	/* Next handler.  */
+  };
+
+
+/* Register HANDLER to handle ioctls with REQUEST values between
+   FIRST_REQUEST and LAST_REQUEST inclusive.  Returns zero if successful.
+   Return nonzero and sets `errno' for an error.  */
+
+extern int hurd_register_ioctl_handler (int first_request, int last_request,
+					ioctl_handler_t handler);
+
+
+/* Define a library-internal handler for ioctl commands between FIRST and
+   LAST inclusive.  The last element gratuitously references HANDLER to
+   avoid `defined but not used' warnings.  */
+
+#define	_HURD_HANDLE_IOCTLS(handler, first, last)			      \
+  static const struct ioctl_handler handler##_ioctl_handler =		      \
+    { (first), (last), (int (*) (int, int, void *)) (handler),	      \
+	(&(handler), &(handler##_ioctl_handler), NULL) };		      \
+  text_set_element (_hurd_ioctl_handler_lists, ##handler##_ioctl_handler)
+
+/* Define a library-internal handler for a single ioctl command.  */
+
+#define _HURD_HANDLE_IOCTL(handler, ioctl) \
+  _HURD_HANDLE_IOCTLS (handler, (ioctl), (ioctl))
+
+
+/* Lookup the handler for the given ioctl request.  */
+
+ioctl_handler_t _hurd_lookup_ioctl_handler (int request);
+
+
+#endif	/* hurd/ioctl.h */
diff --git a/hurd/hurd/port.h b/hurd/hurd/port.h
new file mode 100644
index 0000000000..a057503d4a
--- /dev/null
+++ b/hurd/hurd/port.h
@@ -0,0 +1,152 @@
+/* Lightweight user references for ports.
+Copyright (C) 1993, 1994 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.  */
+
+#ifndef	_HURD_PORT_H
+
+#define	_HURD_PORT_H	1
+#include <features.h>
+
+#include <mach.h>
+#include <hurd/userlink.h>
+#include <spin-lock.h>
+#include <hurd/signal.h>
+
+
+/* Structure describing a cell containing a port.  With the lock held, a
+   user extracts PORT, and attaches his own link (in local storage) to the
+   USERS chain.  PORT can then safely be used.  When PORT is no longer
+   needed, with the lock held, the user removes his link from the chain.
+   If his link is the last, and PORT has changed since he fetched it, the
+   user deallocates the port he used.  See <hurd/userlink.h>.  */
+
+struct hurd_port
+  {
+    spin_lock_t lock;		/* Locks rest.  */
+    struct hurd_userlink *users; /* Chain of users; see below.  */
+    mach_port_t port;		/* Port. */
+  };
+
+
+/* Evaluate EXPR with the variable `port' bound to the port in PORTCELL.  */
+
+#define	HURD_PORT_USE(portcell, expr)					      \
+  ({ struct hurd_port *const __p = (portcell);				      \
+     struct hurd_userlink __link;					      \
+     const mach_port_t port = _hurd_port_get (__p, &__link);		      \
+     __typeof(expr) __result = (expr);					      \
+     _hurd_port_free (__p, &__link, port);				      \
+     __result; })
+
+
+#ifndef _EXTERN_INLINE
+#define _EXTERN_INLINE extern __inline
+#endif
+
+
+/* Initialize *PORT to INIT.  */
+
+_EXTERN_INLINE void
+_hurd_port_init (struct hurd_port *port, mach_port_t init)
+{
+  __spin_lock_init (&port->lock);
+  port->users = NULL;
+  port->port = init;
+}
+
+
+/* Get a reference to *PORT, which is locked.
+   Pass return value and LINK to _hurd_port_free when done.  */
+
+_EXTERN_INLINE mach_port_t
+_hurd_port_locked_get (struct hurd_port *port,
+		       struct hurd_userlink *link)
+{
+  mach_port_t result;
+  result = port->port;
+  if (result != MACH_PORT_NULL)
+    _hurd_userlink_link (&port->users, link);
+  __spin_unlock (&port->lock);
+  return result;
+}
+
+/* Same, but locks PORT first.  */
+
+_EXTERN_INLINE mach_port_t
+_hurd_port_get (struct hurd_port *port,
+		struct hurd_userlink *link)
+{
+  mach_port_t result;
+  HURD_CRITICAL_BEGIN;
+  __spin_lock (&port->lock);
+  result = _hurd_port_locked_get (port, link);
+  HURD_CRITICAL_END;
+  return result;
+}
+
+
+/* Free a reference gotten with `USED_PORT = _hurd_port_get (PORT, LINK);' */
+
+_EXTERN_INLINE void
+_hurd_port_free (struct hurd_port *port,
+		 struct hurd_userlink *link,
+		 mach_port_t used_port)
+{
+  int dealloc;
+  if (used_port == MACH_PORT_NULL)
+    /* When we fetch an empty port cell with _hurd_port_get,
+       it does not link us on the users chain, since there is
+       no shared resource.  */
+    return;
+  HURD_CRITICAL_BEGIN;
+  __spin_lock (&port->lock);
+  dealloc = _hurd_userlink_unlink (link);
+  __spin_unlock (&port->lock);
+  HURD_CRITICAL_END;
+  if (dealloc)
+    __mach_port_deallocate (__mach_task_self (), used_port);
+}
+
+
+/* Set *PORT's port to NEWPORT.  NEWPORT's reference is consumed by PORT->port.
+   PORT->lock is locked.  */
+
+_EXTERN_INLINE void
+_hurd_port_locked_set (struct hurd_port *port, mach_port_t newport)
+{
+  mach_port_t old;
+  old = _hurd_userlink_clear (&port->users) ? port->port : MACH_PORT_NULL;
+  port->port = newport;
+  __spin_unlock (&port->lock);
+  if (old != MACH_PORT_NULL)
+    __mach_port_deallocate (__mach_task_self (), old);
+}
+
+/* Same, but locks PORT first.  */
+
+_EXTERN_INLINE void
+_hurd_port_set (struct hurd_port *port, mach_port_t newport)
+{
+  HURD_CRITICAL_BEGIN;
+  __spin_lock (&port->lock);
+  _hurd_port_locked_set (port, newport);
+  HURD_CRITICAL_END;
+}
+
+
+#endif	/* hurd/port.h */
diff --git a/hurd/hurd/resource.h b/hurd/hurd/resource.h
new file mode 100644
index 0000000000..ad2a61ab42
--- /dev/null
+++ b/hurd/hurd/resource.h
@@ -0,0 +1,50 @@
+/* Resource limits for the Hurd.
+Copyright (C) 1994 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.  */
+
+#ifndef _HURD_RESOURCE_H
+#define _HURD_RESOURCE_H
+
+#include <sys/types.h>
+#include <sys/resource.h>
+#include <errno.h>
+#include <hurd/process.h>
+
+/* This array contains the current resource limits for the process.  */
+extern struct rlimit _hurd_rlimits[RLIM_NLIMITS];
+extern struct mutex _hurd_rlimit_lock; /* Locks _hurd_rlimits.  */
+
+
+/* Helper function for getpriority and setpriority.  Maps FN over all the
+   processes specified by WHICH and WHO.  PI is non-null if a
+   proc_getprocinfo was already done; FN may use *PI arbitrarily, it is
+   reset on the next call.  Returns FN's result the first time it returns
+   nonzero.  If FN never returns nonzero, this returns zero.  */
+extern error_t _hurd_priority_which_map (enum __priority_which which, int who,
+					 error_t (*fn) (pid_t pid,
+							struct procinfo *pi));
+
+/* Convert between Mach priority values and the priority
+   values used by getpriority, setpriority, and nice.  */
+#define MACH_PRIORITY_TO_NICE(prio) (2 * ((prio) - 12))
+#define NICE_TO_MACH_PRIORITY(nice) (12 + ((nice) / 2))
+
+
+
+
+#endif
diff --git a/hurd/hurd/signal.h b/hurd/hurd/signal.h
new file mode 100644
index 0000000000..76007d5037
--- /dev/null
+++ b/hurd/hurd/signal.h
@@ -0,0 +1,391 @@
+/* Implementing POSIX.1 signals under the Hurd.
+Copyright (C) 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.  */
+
+#ifndef	_HURD_SIGNAL_H
+
+#define	_HURD_SIGNAL_H	1
+#include <features.h>
+/* Make sure <signal.h> is going to define NSIG.  */
+#ifndef __USE_GNU
+#error "Must have `_GNU_SOURCE' feature test macro to use this file"
+#endif
+
+#define __need_NULL
+#include <stddef.h>
+
+#include <mach/mach_types.h>
+#include <mach/port.h>
+#include <mach/message.h>
+#include <hurd/hurd_types.h>
+#include <signal.h>
+#include <errno.h>
+#include <hurd/msg.h>
+
+#include <cthreads.h>		/* For `struct mutex'.  */
+#include <spin-lock.h>
+#include <hurd/threadvar.h>	/* We cache sigstate in a threadvar.  */
+
+
+/* Per-thread signal state.  */
+
+struct hurd_sigstate
+  {
+    spin_lock_t lock;		/* Locks most of the rest of the structure.  */
+
+    int critical_section;	/* Nonzero if in critical section.  */
+
+    thread_t thread;
+    struct hurd_sigstate *next; /* Linked-list of thread sigstates.  */
+
+    sigset_t blocked;		/* What signals are blocked.  */
+    sigset_t pending;		/* Pending signals, possibly blocked.  */
+    struct sigaction actions[NSIG];
+    struct sigaltstack sigaltstack;
+    struct
+      {
+	/* For each signal that may be pending, the
+	   sigcode and error code to deliver it with.  */
+	long int code;
+	error_t error;
+      } pending_data[NSIG];
+
+    /* If `suspended' is set when this thread gets a signal,
+       the signal thread sends an empty message to it.  */
+    mach_port_t suspended;
+
+    /* The following members are not locked.  They are used only by this
+       thread, or by the signal thread with this thread suspended.  */
+
+    volatile mach_port_t intr_port; /* Port interruptible RPC was sent on.  */
+
+    /* If this is not null, the thread is in sigreturn awaiting delivery of
+       pending signals.  This context (the machine-dependent portions only)
+       will be passed to sigreturn after running the handler for a pending
+       signal, instead of examining the thread state.  */
+    struct sigcontext *context;
+  };
+
+/* Linked list of states of all threads whose state has been asked for.  */
+
+extern struct hurd_sigstate *_hurd_sigstates;
+
+extern struct mutex _hurd_siglock; /* Locks _hurd_sigstates.  */
+
+/* Get the sigstate of a given thread, taking its lock.  */
+
+extern struct hurd_sigstate *_hurd_thread_sigstate (thread_t);
+
+/* Get the sigstate of the current thread.
+   This uses a per-thread variable to optimize the lookup.  */
+_EXTERN_INLINE struct hurd_sigstate *
+_hurd_self_sigstate (void)
+{
+  struct hurd_sigstate **location =
+    (void *) __hurd_threadvar_location (_HURD_THREADVAR_SIGSTATE);
+  if (*location == NULL)
+    *location = _hurd_thread_sigstate (__mach_thread_self ());
+  return *location;
+}
+
+/* Thread listening on our message port; also called the "signal thread".  */
+
+extern thread_t _hurd_msgport_thread;
+
+/* Our message port.  We hold the receive right and _hurd_msgport_thread
+   listens for messages on it.  We also hold a send right, for convenience.  */
+
+extern mach_port_t _hurd_msgport;
+
+
+/* Thread to receive process-global signals.  */
+
+extern thread_t _hurd_sigthread;
+
+
+/* Resource limit on core file size.  Enforced by hurdsig.c.  */
+extern int _hurd_core_limit;
+
+/* Critical sections.
+
+   A critical section is a section of code which cannot safely be interrupted
+   to run a signal handler; for example, code that holds any lock cannot be
+   interrupted lest the signal handler try to take the same lock and
+   deadlock result.  */
+
+_EXTERN_INLINE void *
+_hurd_critical_section_lock (void)
+{
+  struct hurd_sigstate **location =
+    (void *) __hurd_threadvar_location (_HURD_THREADVAR_SIGSTATE);
+  struct hurd_sigstate *ss = *location;
+  if (ss == NULL)
+    /* The thread variable is unset; this must be the first time we've
+       asked for it.  In this case, the critical section flag cannot
+       possible already be set.  Look up our sigstate structure the slow
+       way; this locks the sigstate lock.  */
+    ss = *location = _hurd_thread_sigstate (__mach_thread_self ());
+  else
+    __spin_lock (&ss->lock);
+
+  if (ss->critical_section)
+    {
+      /* We are already in a critical section, so do nothing.  */
+      __spin_unlock (&ss->lock);
+      return NULL;
+    }
+
+  /* Set the critical section flag so no signal handler will run.  */
+  ss->critical_section = 1;
+  __spin_unlock (&ss->lock);
+
+  /* Return our sigstate pointer; this will be passed to
+     _hurd_critical_section_unlock to clear the critical section flag. */
+  return ss;
+}
+
+_EXTERN_INLINE void
+_hurd_critical_section_unlock (void *our_lock)
+{
+  if (our_lock == NULL)
+    /* The critical section lock was held when we began.  Do nothing.  */
+    return;
+  else
+    {
+      /* It was us who acquired the critical section lock.  Clear the
+	 critical section flag.  */
+      struct hurd_sigstate *ss = our_lock;
+      sigset_t pending;
+      __spin_lock (&ss->lock);
+      ss->critical_section = 0;
+      pending = ss->pending & ~ss->blocked;
+      __spin_unlock (&ss->lock);
+      if (pending)
+	/* There are unblocked signals pending, which weren't
+	   delivered because we were in the critical section.
+	   Tell the signal thread to deliver them now.  */
+	__msg_sig_post (_hurd_msgport, 0, __mach_task_self ());
+    }
+}
+
+/* Convenient macros for simple uses of critical sections.
+   These two must be used as a pair at the same C scoping level.  */
+
+#define HURD_CRITICAL_BEGIN \
+  { void *__hurd_critical__ = _hurd_critical_section_lock ()
+#define HURD_CRITICAL_END \
+      _hurd_critical_section_unlock (__hurd_critical__); } while (0)
+
+/* Initialize the signal code, and start the signal thread.  */
+
+extern void _hurdsig_init (void);
+
+/* Initialize proc server-assisted fault recovery for the signal thread.  */
+
+extern void _hurdsig_fault_init (void);
+
+/* Raise a signal as described by SIGNO, SIGCODE and SIGERROR, on the
+   thread whose sigstate SS points to.  If SS is a null pointer, this
+   instead affects the calling thread.  */
+
+extern void _hurd_raise_signal (struct hurd_sigstate *ss,
+				int signo, long int sigcode, int sigerror);
+
+/* Translate a Mach exception into a signal (machine-dependent).  */
+
+extern void _hurd_exception2signal (int exception, int code, int subcode,
+				    int *signo, long int *sigcode, int *error);
+
+
+/* Make the thread described by SS take the signal described by SIGNO and
+   SIGCODE.  If the process is traced, this will in fact stop with a SIGNO
+   as the stop signal unless UNTRACED is nonzero.  When the signal can be
+   considered delivered, sends a sig_post reply message on REPLY_PORT
+   indicating success.  SS is not locked.  */
+
+extern void _hurd_internal_post_signal (struct hurd_sigstate *ss,
+					int signo, long int sigcode, int error,
+					mach_port_t reply_port,
+					mach_msg_type_name_t reply_port_type,
+					int untraced);
+
+/* Set up STATE and SS to handle signal SIGNO by running HANDLER.  If
+   RPC_WAIT is nonzero, the thread needs to wait for a pending RPC to
+   finish before running the signal handler.  The handler is passed SIGNO,
+   SIGCODE, and the returned `struct sigcontext' (which resides on the
+   stack the handler will use, and which describes the state of the thread
+   encoded in STATE before running the handler).  */
+
+struct machine_thread_all_state;
+extern struct sigcontext *
+_hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler,
+			int signo, long int sigcode,
+			int rpc_wait, struct machine_thread_all_state *state);
+
+/* Function run by the signal thread to receive from the signal port.  */
+
+extern void _hurd_msgport_receive (void);
+
+/* STATE describes a thread that had intr_port set (meaning it was inside
+   HURD_EINTR_RPC), after it has been thread_abort'd.  It it looks to have
+   just completed a mach_msg_trap system call that returned
+   MACH_RCV_INTERRUPTED, return nonzero and set *PORT to the receive right
+   being waited on.  */
+
+extern int _hurdsig_rcv_interrupted_p (struct machine_thread_all_state *state,
+				       mach_port_t *port);
+
+/* Set up STATE with a thread state that, when resumed, is
+   like `longjmp (_hurd_sigthread_fault_env, 1)'.  */
+
+extern void _hurd_initialize_fault_recovery_state (void *state);
+
+
+/* Function run for SIGINFO when its action is SIG_DFL and the current
+   process is the session leader.  */
+
+extern void _hurd_siginfo_handler (int);
+
+
+/* Perform interruptible RPC CALL on PORT.
+   The call should use 
+   The args in CALL should be constant or local variable refs.
+   They may be evaluated many times, and must not change.
+   PORT must not be deallocated before this RPC is finished.  */
+#define	HURD_EINTR_RPC(port, call)					      \
+  ({									      \
+    __label__ __do_call;	/* Give this label block scope.  */	      \
+    error_t __err;							      \
+    struct hurd_sigstate *__ss = _hurd_self_sigstate ();		      \
+    __do_call:								      \
+    /* Tell the signal thread that we are doing an interruptible RPC on	      \
+       this port.  If we get a signal and should return EINTR, the signal     \
+       thread will set this variable to MACH_PORT_NULL.  The RPC might	      \
+       return EINTR when some other thread gets a signal, in which case we    \
+       want to restart our call.  */					      \
+    __ss->intr_port = (port);						      \
+    /* A signal may arrive here, after intr_port is set, but before the	      \
+       mach_msg system call.  The signal handler might do an interruptible    \
+       RPC, and clobber intr_port; then it would not be set properly when     \
+       we actually did send the RPC, and a later signal wouldn't interrupt    \
+       that RPC.  So, _hurd_setup_sighandler saves intr_port in the	      \
+       sigcontext, and sigreturn restores it.  */			      \
+    switch (__err = (call))						      \
+      {									      \
+      case EINTR:		/* RPC went out and was interrupted.  */      \
+      case MACH_SEND_INTERRUPTED: /* RPC didn't get out.  */		      \
+	if (__ss->intr_port != MACH_PORT_NULL)				      \
+	  /* If this signal was for us and it should interrupt calls, the     \
+             signal thread will have cleared SS->intr_port.  Since it's not   \
+             cleared, the signal was for another thread, or SA_RESTART is     \
+             set.  Restart the interrupted call.  */			      \
+	  goto __do_call;						      \
+	/* FALLTHROUGH */						      \
+      case MACH_RCV_PORT_DIED:						      \
+	/* Server didn't respond to interrupt_operation,		      \
+	   so the signal thread destroyed the reply port.  */		      \
+	__err = EINTR;							      \
+	break;								      \
+      default:			/* Quiet -Wswitch-enum.  */		      \
+      }									      \
+    __ss->intr_port = MACH_PORT_NULL;					      \
+    __err;								      \
+  })									      \
+
+
+/* Mask of signals that cannot be caught, blocked, or ignored.  */
+#define	_SIG_CANT_MASK	(__sigmask (SIGSTOP) | __sigmask (SIGKILL))
+
+/* Do an RPC to a process's message port.
+
+   Each argument is an expression which returns an error code; each
+   expression may be evaluated several times.  FETCH_MSGPORT_EXPR should
+   fetch the appropriate message port and store it in the local variable
+   `msgport'; it will be deallocated after use.  FETCH_REFPORT_EXPR should
+   fetch the appropriate message port and store it in the local variable
+   `refport' (if no reference port is needed in the call, then
+   FETCH_REFPORT_EXPR should be simply KERN_SUCCESS or 0); if
+   DEALLOC_REFPORT evaluates to nonzero it will be deallocated after use,
+   otherwise the FETCH_REFPORT_EXPR must take care of user references to
+   `refport'.  RPC_EXPR should perform the desired RPC operation using
+   `msgport' and `refport'.
+
+   The reason for the complexity is that a process's message port and
+   reference port may change between fetching those ports and completing an
+   RPC using them (usually they change only when a process execs).  The RPC
+   will fail with MACH_SEND_INVALID_DEST if the msgport dies before we can
+   send the RPC request; or with MIG_SERVER_DIED if the msgport was
+   destroyed after we sent the RPC request but before it was serviced.  In
+   either of these cases, we retry the entire operation, discarding the old
+   message and reference ports and fetch them anew.  */
+
+#define HURD_MSGPORT_RPC(fetch_msgport_expr,				      \
+			 fetch_refport_expr, dealloc_refport,		      \
+			 rpc_expr) 					      \
+({									      \
+    error_t __err;							      \
+    mach_port_t msgport, refport = MACH_PORT_NULL;			      \
+    do									      \
+      {									      \
+	/* Get the message port.  */					      \
+	if (__err = (fetch_msgport_expr))				      \
+	  break;							      \
+	/* Get the reference port.  */					      \
+	if (__err = (fetch_refport_expr))				      \
+	  {								      \
+	    /* Couldn't get it; deallocate MSGPORT and fail.  */	      \
+	    __mach_port_deallocate (__mach_task_self (), msgport);	      \
+	    break;							      \
+	  }								      \
+	__err = (rpc_expr);						      \
+	__mach_port_deallocate (__mach_task_self (), msgport);		      \
+	if ((dealloc_refport) && refport != MACH_PORT_NULL)		      \
+	  __mach_port_deallocate (__mach_task_self (), refport);    	      \
+      } while (__err == MACH_SEND_INVALID_DEST ||			      \
+	       __err == MIG_SERVER_DIED);				      \
+    __err;								      \
+})
+
+/* Some other parts of the library need to preempt signals, to detect
+   errors that should not result in a POSIX signal.  For example, when
+   some mapped region of memory is used, an extraneous SIGSEGV might be
+   generated when the mapping server returns an error for a page fault.  */
+
+struct hurd_signal_preempt
+  {
+    /* Function to examine a thread receiving a given signal.  The handler
+       is called even for blocked signals.  This function is run in the
+       signal thread, with THREAD's sigstate locked; it should be as simple
+       and robust as possible.  THREAD is the thread which is about to
+       receive the signal.  SIGNO and SIGCODE would be passed to the normal
+       handler.
+
+       If the return value is SIG_DFL, normal signal processing continues.
+       If it is SIG_IGN, the signal is ignored.
+       Any other value is used in place of the normal handler.  */
+    sighandler_t (*handler) (thread_t thread,
+			     int signo, long int sigcode, int sigerror);
+    long int first, last;	/* Range of sigcodes this handler wants.  */
+    struct hurd_signal_preempt *next; /* Next handler on the chain. */
+  };
+
+extern struct hurd_signal_preempt *_hurd_signal_preempt[NSIG];
+extern struct mutex _hurd_signal_preempt_lock;
+
+
+#endif	/* hurd/signal.h */
diff --git a/hurd/hurd/threadvar.h b/hurd/hurd/threadvar.h
new file mode 100644
index 0000000000..eab133a2f6
--- /dev/null
+++ b/hurd/hurd/threadvar.h
@@ -0,0 +1,107 @@
+/* Internal per-thread variables for the Hurd.
+Copyright (C) 1994 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.  */
+
+#ifndef _HURD_THREADVAR_H
+#define	_HURD_THREADVAR_H
+
+/* The per-thread variables are found by ANDing this mask
+   with the value of the stack pointer and then adding this offset.
+
+   In the multi-threaded case, cthreads initialization sets
+   __hurd_threadvar_stack_mask to ~(cthread_stack_size - 1), a mask which
+   finds the base of the fixed-size cthreads stack; and
+   __hurd_threadvar_stack_offset to a small offset that skips the data
+   cthreads itself maintains at the base of each thread's stack.
+
+   In the single-threaded case, __hurd_threadvar_stack_mask is zero, so the
+   stack pointer is ignored; and __hurd_threadvar_stack_offset gives the
+   address of a small allocated region which contains the variables for the
+   single thread.  */
+   
+extern unsigned long int __hurd_threadvar_stack_mask;
+extern unsigned long int __hurd_threadvar_stack_offset;
+
+/* A special case must always be made for the signal thread.  Even when there
+   is only one user thread and an allocated region can be used for the user
+   thread's variables, the signal thread needs to have its own location for
+   per-thread variables.  The variables __hurd_sigthread_stack_base and
+   __hurd_sigthread_stack_end define the bounds of the stack used by the
+   signal thread, so that thread can always be specifically identified.  */
+
+extern unsigned long int __hurd_sigthread_stack_base;
+extern unsigned long int __hurd_sigthread_stack_end;
+extern unsigned long int *__hurd_sigthread_variables;
+
+
+/* At the location described by the two variables above,
+   there are __hurd_threadvar_max `unsigned long int's of per-thread data.  */
+extern unsigned int __hurd_threadvar_max;
+
+/* These values are the indices for the standard per-thread variables.  */
+enum __hurd_threadvar_index
+  {
+    _HURD_THREADVAR_MIG_REPLY,	/* Reply port for MiG user stub functions.  */
+    _HURD_THREADVAR_ERRNO,	/* `errno' value for this thread.  */
+    _HURD_THREADVAR_SIGSTATE,	/* This thread's `struct hurd_sigstate'.  */
+    _HURD_THREADVAR_DYNAMIC_USER, /* Dynamically-assigned user variables. */
+    _HURD_THREADVAR_MAX		/* Default value for __hurd_threadvar_max.  */
+  };
+
+
+#ifndef _EXTERN_INLINE
+#define _EXTERN_INLINE extern __inline
+#endif
+
+/* Return the location of the value for the per-thread variable with index
+   INDEX used by the thread whose stack pointer is SP.  */
+
+_EXTERN_INLINE unsigned long int *
+__hurd_threadvar_location_from_sp (enum __hurd_threadvar_index __index,
+				   void *__sp)
+{
+  unsigned long int __stack = (unsigned long int) __sp;
+  return &((__stack >= __hurd_sigthread_stack_base &&
+	    __stack < __hurd_sigthread_stack_end)
+	   ? __hurd_sigthread_variables
+	   : (unsigned long int *) ((__stack & __hurd_threadvar_stack_mask) +
+				    __hurd_threadvar_stack_offset))[__index];
+}
+
+#include <machine-sp.h>		/* Define __thread_stack_pointer.  */
+
+/* Return the location of the current thread's value for the
+   per-thread variable with index INDEX.  */
+
+_EXTERN_INLINE unsigned long int *
+__hurd_threadvar_location (enum __hurd_threadvar_index __index)
+{
+  return __hurd_threadvar_location_from_sp (__index,
+					    __thread_stack_pointer ());
+}
+
+/* Return the current thread's location for `errno'.
+   The syntax of this function allows redeclarations like `int errno'.  */
+_EXTERN_INLINE int *
+__hurd_errno_location (void)
+{
+  return (int *) __hurd_threadvar_location (_HURD_THREADVAR_ERRNO);
+}
+
+
+#endif	/* hurd/threadvar.h */
diff --git a/hurd/hurd/userlink.h b/hurd/hurd/userlink.h
new file mode 100644
index 0000000000..337d46aef6
--- /dev/null
+++ b/hurd/hurd/userlink.h
@@ -0,0 +1,105 @@
+/* Support for chains recording users of a resource; `struct hurd_userlink'.
+Copyright (C) 1994 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.  */
+
+#ifndef	_HURD_USERLINK_H
+
+#define	_HURD_USERLINK_H	1
+#include <features.h>
+
+#define __need_NULL
+#include <stddef.h>
+
+
+/* This structure is simply a doubly-linked list.  Users of a given
+   resource are recorded by their presence in a list associated with that
+   resource.  A user attaches his own link (in local storage) to a shared
+   chain at the time he begins using some resource.  When finished with
+   that resource, the user removes his link from the chain.  If his link is
+   the last (there are no other users of the resource), and his chain has
+   been detached from the shared cell (the resource in the cell has been
+   replaced), then the user deallocates the resource that he used.  */
+
+struct hurd_userlink
+  {
+    struct hurd_userlink *next, **prevp;
+  };
+
+
+#ifndef _EXTERN_INLINE
+#define _EXTERN_INLINE extern __inline
+#endif
+
+
+/* Attach LINK to the chain of users at *CHAINP.  */
+
+_EXTERN_INLINE void
+_hurd_userlink_link (struct hurd_userlink **chainp,
+		     struct hurd_userlink *link)
+{
+  link->next = *chainp;
+  if (link->next)
+    link->next->prevp = &link->next;
+  link->prevp = chainp;
+  *chainp = link;
+}
+
+
+/* Detach LINK from its chain.  If the return value is nonzero, the caller
+   should deallocate the resource he started using after attaching LINK to
+   the chain it's on.  If the return value is zero, then someone else is
+   still using the resource.  */
+
+_EXTERN_INLINE int
+_hurd_userlink_unlink (struct hurd_userlink *link)
+{
+  /* The caller should deallocate the resource he used if his chain has
+     been detached from the cell (and thus has a nil `prevp'), and there is
+     no next link representing another user reference to the same resource. */
+  int dealloc = ! link->next && ! link->prevp;
+
+  /* Remove our link from the chain of current users.  */
+  if (link->prevp)
+    *link->prevp = link->next;
+  if (link->next)
+    link->next->prevp = link->prevp;
+
+  return dealloc;
+}
+
+
+/* Clear all users from *CHAINP.  Call this when the resource *CHAINP
+   protects is changing.  If the return value is nonzero, no users are on
+   the chain and the caller should deallocate the resource.  If the return
+   value is zero, someone is still using the resource and they will
+   deallocate it when they are finished.  */
+
+_EXTERN_INLINE int
+_hurd_userlink_clear (struct hurd_userlink **chainp)
+{
+  if (*chainp == NULL)
+    return 1;
+
+  /* Detach the chain of current users from the cell.  The last user to
+     remove his link from that chain will deallocate the old resource.  */
+  (*chainp)->prevp = NULL;
+  *chainp = NULL;
+  return 0;
+}
+
+#endif	/* hurd/userlink.h */