Thu Jan 4 11:35:18 1996 Roland McGrath <roland@churchy.gnu.ai.mit.edu>

	* sysdeps/mach/hurd/setitimer.c: Code rearranged a bit to use new
	preemption interface.

	* sysdeps/mach/hurd/i386/trampoline.c (_hurd_setup_sighandler):
	Use _hurdsig_catch_memory_fault.

	* hurd/Makefile (headers): Add hurd/sigpreempt.h.
	(sig): Add catch-signal.

	* hurd/hurdfault.c (_hurdsig_fault_catch_exception_raise):
	Rewritten using a preempter in new interface.
	* hurd/hurdfault.h (_hurdsig_catch_fault): Likewise.
	(_hurdsig_catch_memory_fault): New macro.

6 files changed, 102 insertions, 81 deletions

diff --git a/ChangeLog b/ChangeLog
index 42bd5c6f2e..c7b7ded383 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,19 @@
+Thu Jan  4 11:35:18 1996  Roland McGrath  <roland@churchy.gnu.ai.mit.edu>
+
+	* sysdeps/mach/hurd/setitimer.c: Code rearranged a bit to use new
+	preemption interface.
+
+	* sysdeps/mach/hurd/i386/trampoline.c (_hurd_setup_sighandler):
+	Use _hurdsig_catch_memory_fault.
+
+	* hurd/Makefile (headers): Add hurd/sigpreempt.h.
+	(sig): Add catch-signal.
+
+	* hurd/hurdfault.c (_hurdsig_fault_catch_exception_raise):
+	Rewritten using a preempter in new interface.
+	* hurd/hurdfault.h (_hurdsig_catch_fault): Likewise.
+	(_hurdsig_catch_memory_fault): New macro.
+
 Wed Jan  3 20:23:42 1996  Roland McGrath  <roland@churchy.gnu.ai.mit.edu>
 
 	* hurd/catch-signal.c: New file.
diff --git a/hurd/Makefile b/hurd/Makefile
index 69f9e96031..fe9e43e392 100644
--- a/hurd/Makefile
+++ b/hurd/Makefile
@@ -1,4 +1,4 @@
-# Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
+# Copyright (C) 1991, 92, 93, 94, 95, 96 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
@@ -25,8 +25,8 @@ include ../Makeconfig
 
 
 headers = hurd.h $(interface-headers) \
-	  $(addprefix hurd/,fd.h id.h port.h signal.h userlink.h \
-		            resource.h threadvar.h lookup.h)
+	  $(addprefix hurd/,fd.h id.h port.h signal.h sigpreempt.h \
+			    userlink.h resource.h threadvar.h lookup.h)
 
 distribute := hurdstartup.h hurdfault.h intr-rpc.defs STATUS
 
@@ -51,10 +51,10 @@ routines = hurdstartup hurdinit \
 	   fopenport \
  	   vpprintf \
 	   ports-get ports-set hurdports hurdmsg \
-	   $(sig) $(dtable) hurdinline port-cleanup
+	   $(sig) $(dtable) hurdinline port-cleanup # report-wait
 sig	= hurdsig hurdfault faultexc siginfo hurd-raise preempt-sig \
 	  trampoline longjmp-ts catch-exc exc2signal hurdkill sigunwind \
-	  thread-self thread-cancel intr-msg
+	  thread-self thread-cancel intr-msg catch-signal
 dtable	= dtable port2fd new-fd alloc-fd intern-fd \
 	  getdport openport \
 	  fd-close fd-read fd-write hurdioctl ctty-input ctty-output
diff --git a/hurd/hurdfault.c b/hurd/hurdfault.c
index 5aedc582ce..2a30db085e 100644
--- a/hurd/hurdfault.c
+++ b/hurd/hurdfault.c
@@ -1,5 +1,5 @@
 /* Handle faults in the signal thread.
-Copyright (C) 1994, 1995 Free Software Foundation, Inc.
+Copyright (C) 1994, 1995, 1996 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
@@ -29,13 +29,10 @@ Cambridge, MA 02139, USA.  */
 #include <assert.h>
 
 jmp_buf _hurdsig_fault_env;
+struct hurd_signal_preempter _hurdsig_fault_preempter;
 
 static mach_port_t forward_sigexc;
 
-int _hurdsig_fault_expect_signo;
-long int _hurdsig_fault_sigcode;
-int _hurdsig_fault_sigerror;
-
 kern_return_t
 _hurdsig_fault_catch_exception_raise (mach_port_t port,
 				      thread_t thread,
@@ -45,6 +42,8 @@ _hurdsig_fault_catch_exception_raise (mach_port_t port,
 				      int subcode)
 {
   int signo;
+  long int sigcode;
+  int sigerror;
 
   if (port != forward_sigexc ||
       thread != _hurd_msgport_thread || task != __mach_task_self ())
@@ -52,10 +51,11 @@ _hurdsig_fault_catch_exception_raise (mach_port_t port,
 
   /* Call the machine-dependent function to translate the Mach exception
      codes into a signal number and subcode.  */
-  _hurd_exception2signal (exception, code, subcode, &signo,
-			  &_hurdsig_fault_sigcode, &_hurdsig_fault_sigerror);
+  _hurd_exception2signal (exception, code, subcode,
+			  &signo, &sigcode, &sigerror);
 
-  return signo == _hurdsig_fault_expect_signo ? 0 : EGREGIOUS;
+  return HURD_PREEMPT_SIGNAL_P (&_hurdsig_fault_preempter, signo, sigcode)
+    ? 0 : EGREGIOUS;
 }
 
 static void
@@ -85,19 +85,17 @@ faulted (void)
 
   /* Run the exc demuxer which should call the server function above.
      That function returns 0 if the exception was expected.  */
-  switch (_hurdsig_fault_exc_server (&request.head, &reply.head))
-    {
-    case KERN_SUCCESS:
-      if (reply.head.msgh_remote_port != MACH_PORT_NULL)
-	__mach_msg (&reply.head, MACH_SEND_MSG, reply.head.msgh_size,
-		    0, MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
-      break;
-    default:
-      __mach_msg_destroy (&request.head);
-    case MIG_NO_REPLY:
-    }
-
-  _hurdsig_fault_expect_signo = 0;
+  _hurdsig_fault_exc_server (&request.head, &reply.head);
+  if (reply.head.msgh_remote_port != MACH_PORT_NULL)
+    __mach_msg (&reply.head, MACH_SEND_MSG, reply.head.msgh_size,
+		0, MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+  if (reply.result == MIG_BAD_ID)
+    __mach_msg_destroy (&request.head);
+
+  if (reply.result)
+    __libc_fatal ("BUG: unexpected fault in signal thread\n");
+
+  _hurdsig_fault_preempter.signals = 0;
   longjmp (_hurdsig_fault_env, 1);
 }
 
@@ -125,8 +123,10 @@ _hurdsig_fault_init (void)
   err = __mach_port_insert_right (__mach_task_self (), sigexc,
 				  sigexc, MACH_MSG_TYPE_MAKE_SEND);
   assert_perror (err);
+#if 0				/* XXX gdb bites */
   err = __thread_set_special_port (_hurd_msgport_thread,
 				   THREAD_EXCEPTION_PORT, sigexc);
+#endif
   __mach_port_deallocate (__mach_task_self (), sigexc);
   assert_perror (err);
 
diff --git a/hurd/hurdfault.h b/hurd/hurdfault.h
index 00ec905925..4b6aaed6ae 100644
--- a/hurd/hurdfault.h
+++ b/hurd/hurdfault.h
@@ -1,5 +1,5 @@
 /* Declarations for handling faults in the signal thread.
-Copyright (C) 1994 Free Software Foundation, Inc.
+Copyright (C) 1994, 1996 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
@@ -20,6 +20,7 @@ Cambridge, MA 02139, USA.  */
 #ifndef _HURD_FAULT_H
 #define _HURD_FAULT_H
 
+#include <hurd/sigpreempt.h>
 #include <setjmp.h>
 
 /* Call this before code that might fault in the signal thread; SIGNO is
@@ -27,23 +28,24 @@ Cambridge, MA 02139, USA.  */
    returns zero the first time, and returns again nonzero if the signal
    does arrive.  */
 
-#define _hurdsig_catch_fault(signo) \
-  (_hurdsig_fault_expect_signo = (signo), setjmp (_hurdsig_fault_env))
+#define _hurdsig_catch_fault(sigset, firstcode, lastcode)	\
+  (_hurdsig_fault_preempter.signals = (sigset),			\
+   _hurdsig_fault_preempter.first = (long int) (firstcode),	\
+   _hurdsig_fault_preempter.last = (long int) (lastcode),	\
+   setjmp (_hurdsig_fault_env))
 
 /* Call this at the end of a section protected by _hurdsig_catch_fault.  */
 
 #define _hurdsig_end_catch_fault() \
-  (_hurdsig_fault_expect_signo = 0)
+  (_hurdsig_fault_preempter.signals = 0)
 
 extern jmp_buf _hurdsig_fault_env;
-extern int _hurdsig_fault_expect_signo;
+extern struct hurd_signal_preempter _hurdsig_fault_preempter;
 
-/* If _hurdsig_catch_fault returns nonzero, these variables
-   contain information about the signal that arrived.  */
 
+#define _hurdsig_catch_memory_fault(object) \
+  _hurdsig_catch_fault (sigmask (SIGSEGV) | sigmask (SIGBUS), \
+			(object), (object) + 1)
 
 
-extern long int _hurdsig_fault_sigcode;
-extern int _hurdsig_fault_sigerror;
-
-#endif	/* hurd/fault.h */
+#endif	/* hurdfault.h */
diff --git a/sysdeps/mach/hurd/i386/trampoline.c b/sysdeps/mach/hurd/i386/trampoline.c
index 9e947a46e7..f64539a384 100644
--- a/sysdeps/mach/hurd/i386/trampoline.c
+++ b/sysdeps/mach/hurd/i386/trampoline.c
@@ -1,5 +1,5 @@
 /* Set thread_state for sighandler, and sigcontext to recover.  i386 version.
-Copyright (C) 1994, 1995 Free Software Foundation, Inc.
+Copyright (C) 1994, 1995, 1996 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
@@ -24,7 +24,7 @@ Cambridge, MA 02139, USA.  */
 #include <errno.h>
 #include "hurdfault.h"
 
-     
+
 struct mach_msg_trap_args
   {
     void *retaddr;		/* Address mach_msg_trap will return to.  */
@@ -50,7 +50,7 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler,
   extern const void _hurd_intr_rpc_msg_sp_restored;
   void *volatile sigsp;
   struct sigcontext *scp;
-  struct 
+  struct
     {
       int signo;
       long int sigcode;
@@ -67,10 +67,7 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler,
       /* We have a previous sigcontext that sigreturn was about
 	 to restore when another signal arrived.  We will just base
 	 our setup on that.  */
-      if (_hurdsig_catch_fault (SIGSEGV))
-	assert (_hurdsig_fault_sigcode >= (long int) ss->context &&
-		_hurdsig_fault_sigcode < (long int) (ss->context + 1));
-      else
+      if (! _hurdsig_catch_memory_fault (ss->context))
 	{
 	  memcpy (&state->basic, &ss->context->sc_i386_thread_state,
 		  sizeof (state->basic));
@@ -97,7 +94,7 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler,
 	 per-thread variables, cthreads.  */
     }
   /* This code has intimate knowledge of the special mach_msg system call
-     done in intr-msg.c; that code does: 
+     done in intr-msg.c; that code does:
 					movl %esp, %ecx
 					leal ARGS, %esp
 	_hurd_intr_rpc_msg_cx_sp:	movl $-25, %eax
@@ -107,7 +104,7 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler,
      We must check for the window during which %esp points at the
      mach_msg arguments.  The space below until %ecx is used by
      the _hurd_intr_rpc_mach_msg frame, and must not be clobbered.  */
-  else if (state->basic.eip >= (int) &_hurd_intr_rpc_msg_cx_sp && 
+  else if (state->basic.eip >= (int) &_hurd_intr_rpc_msg_cx_sp &&
 	   state->basic.eip < (int) &_hurd_intr_rpc_msg_sp_restored)
     /* The SP now points at the mach_msg args, but there is more stack
        space used below it.  The real SP is saved in %ecx; we must push the
@@ -121,10 +118,8 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler,
   sigsp -= sizeof (*stackframe);
   stackframe = sigsp;
 
-  if (_hurdsig_catch_fault (SIGSEGV))
+  if (_hurdsig_catch_memory_fault (stackframe))
     {
-      assert (_hurdsig_fault_sigcode >= (long int) stackframe &&
-	      _hurdsig_fault_sigcode <= (long int) (stackframe + 1));
       /* We got a fault trying to write the stack frame.
 	 We cannot set up the signal handler.
 	 Returning NULL tells our caller, who will nuke us with a SIGILL.  */
@@ -187,17 +182,15 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler,
 	 still waiting for a reply.  We will have it run the special
 	 trampoline code which retries the message receive before running
 	 the signal handler.
-	 
+
 	 To do this we change the OPTION argument on its stack to enable only
 	 message reception, since the request message has already been
 	 sent.  */
 
       struct mach_msg_trap_args *args = (void *) state->basic.esp;
 
-      if (_hurdsig_catch_fault (SIGSEGV))
+      if (_hurdsig_catch_memory_fault (args))
 	{
-	  assert (_hurdsig_fault_sigcode >= (long int) args &&
-		  _hurdsig_fault_sigcode < (long int) (args + 1));
 	  /* Faulted accessing ARGS.  Bomb.  */
 	  return NULL;
 	}
diff --git a/sysdeps/mach/hurd/setitimer.c b/sysdeps/mach/hurd/setitimer.c
index 4f494a4c6e..cba1d0e65a 100644
--- a/sysdeps/mach/hurd/setitimer.c
+++ b/sysdeps/mach/hurd/setitimer.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1994, 1995 Free Software Foundation, Inc.
+/* Copyright (C) 1994, 1995, 1996 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
@@ -22,6 +22,7 @@ Cambridge, MA 02139, USA.  */
 #include <sys/time.h>
 #include <hurd.h>
 #include <hurd/signal.h>
+#include <hurd/sigpreempt.h>
 #include <hurd/msg_request.h>
 #include <mach/message.h>
 
@@ -109,9 +110,29 @@ timer_thread (void)
     }
 }
 
-/* Forward declaration.  */
-static sighandler_t preempt_sigalrm (thread_t thread, int signo,
-				     long int sigcode, int sigerror);
+
+static sighandler_t
+restart_itimer (struct hurd_signal_preempter *preempter,
+		struct hurd_sigstate *ss,
+		int *signo, long int *sigcode,
+		int *sigerror)
+{
+  static int setitimer_locked (const struct itimerval *new,
+			       struct itimerval *old, void *crit);
+
+  /* This function gets called in the signal thread
+     each time a SIGALRM is arriving (even if blocked).  */
+  struct itimerval it;
+
+  /* Either reload or disable the itimer.  */
+  __spin_lock (&_hurd_itimer_lock);
+  it.it_value = it.it_interval = _hurd_itimerval.it_interval;
+  setitimer_locked (&it, NULL, NULL);
+
+  /* Continue with normal delivery (or hold, etc.) of SIGALRM.  */
+  return SIG_ERR;
+}
+
 
 /* Called before any normal SIGALRM signal is delivered.
    Reload the itimer, or disable the itimer.  */
@@ -138,12 +159,20 @@ setitimer_locked (const struct itimerval *new, struct itimerval *old,
     {
       /* Make sure the itimer thread is set up.  */
 
-      if (_hurd_signal_preempt[SIGALRM] == NULL)
+      /* Set up a signal preempter global for all threads to
+	 run `restart_itimer' each time a SIGALRM would arrive.  */
+      static struct hurd_signal_preempter preempter =
+	{
+	  __sigmask (SIGALRM), 0, 0,
+	  &restart_itimer,
+	};
+      __mutex_lock (&_hurd_siglock);
+      if (! preempter.next && _hurdsig_preempters != &preempter)
 	{
-	  static struct hurd_signal_preempt preempt =
-	    { preempt_sigalrm, 0, 0, NULL };
-	  _hurd_signal_preempt[SIGALRM] = &preempt;
+	  preempter.next = _hurdsig_preempters;
+	  _hurdsig_preempters = &preempter;
 	}
+      __mutex_unlock (&_hurd_siglock);
 
       if (_hurd_itimer_port == MACH_PORT_NULL)
 	{
@@ -170,7 +199,7 @@ setitimer_locked (const struct itimerval *new, struct itimerval *old,
 					 &_hurd_itimer_thread_stack_size))
 	    {
 	      __thread_terminate (_hurd_itimer_thread);
-	      _hurd_itimer_thread = MACH_PORT_NULL;	  
+	      _hurd_itimer_thread = MACH_PORT_NULL;
 	      goto out;
 	    }
 	  _hurd_itimer_thread_suspended = 1;
@@ -293,25 +322,6 @@ DEFUN(__setitimer, (which, new, old),
   __spin_lock (&_hurd_itimer_lock);
   return setitimer_locked (new, old, crit);
 }
-
-static sighandler_t
-preempt_sigalrm (thread_t thread, int signo, long int sigcode, int sigerror)
-{
-  struct itimerval it;
-
-  if (thread != _hurd_sigthread || signo != SIGALRM || sigcode != 0)
-    /* Too much monkey business.  */
-    return SIG_DFL;
-
-  /* Either reload or disable the itimer.  */
-  __spin_lock (&_hurd_itimer_lock);
-  it = _hurd_itimerval;
-  it.it_value = it.it_interval;
-  setitimer_locked (&it, NULL, NULL);
-
-  /* Continue with normal delivery of SIGALRM.  */
-  return SIG_DFL;
-}
 
 static void
 fork_itimer (void)