account for the process signal mask when dealing with signals; tested

a while ago by marc@ and brad@

5 files changed, 99 insertions, 25 deletions

diff --git a/lib/libc_r/uthread/pthread_private.h b/lib/libc_r/uthread/pthread_private.h
index cc9abefa7c6..23723ca68e0 100644
--- a/lib/libc_r/uthread/pthread_private.h
+++ b/lib/libc_r/uthread/pthread_private.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pthread_private.h,v 1.34 2002/01/19 23:49:32 fgsch Exp $	*/
+/*	$OpenBSD: pthread_private.h,v 1.35 2002/02/21 20:57:41 fgsch Exp $	*/
 /*
  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>.
  * All rights reserved.
@@ -997,6 +997,16 @@ SCLASS struct  sigaction _thread_sigact[NSIG];
 SCLASS int	_thread_dfl_count[NSIG];
 
 /*
+ * Pending signals and mask for this process:
+ */
+SCLASS sigset_t		_process_sigpending;
+SCLASS sigset_t		_process_sigmask
+#ifdef GLOBAL_PTHREAD_PRIVATE
+= 0
+#endif
+;
+
+/*
  * Scheduling queues:
  */
 SCLASS pq_queue_t		_readyq;
@@ -1098,6 +1108,7 @@ void    _thread_cleanupspecific(void);
 void    _thread_dump_info(void);
 void    _thread_init(void);
 void    _thread_kern_sched(struct sigcontext *);
+void    _thread_kern_sched_sig(void);
 void    _thread_kern_sched_state(enum pthread_state,char *fname,int lineno);
 void	_thread_kern_sched_state_unlock(enum pthread_state state,
 	    spinlock_t *lock, char *fname, int lineno);
diff --git a/lib/libc_r/uthread/uthread_init.c b/lib/libc_r/uthread/uthread_init.c
index 39242c8fd22..d9f398c381b 100644
--- a/lib/libc_r/uthread/uthread_init.c
+++ b/lib/libc_r/uthread/uthread_init.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uthread_init.c,v 1.20 2002/01/17 23:12:09 fgsch Exp $	*/
+/*	$OpenBSD: uthread_init.c,v 1.21 2002/02/21 20:57:41 fgsch Exp $	*/
 /*
  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
  * All rights reserved.
@@ -224,6 +224,9 @@ _thread_init(void)
 		act.sa_handler = (void (*) ()) _thread_sig_handler;
 		act.sa_flags = 0;
 
+		/* Clear pending signals for the process: */
+		sigemptyset(&_process_sigpending);
+
 		/* Initialize signal handling: */
 		_thread_sig_init();
 
@@ -261,6 +264,9 @@ _thread_init(void)
 			PANIC("Cannot initialize signal handler");
 		}
 
+		/* Get the process signal mask: */
+		_thread_sys_sigprocmask(SIG_SETMASK, NULL, &_process_sigmask);
+
 		/* Get the kernel clockrate: */
 		mib[0] = CTL_KERN;
 		mib[1] = KERN_CLOCKRATE;
diff --git a/lib/libc_r/uthread/uthread_kern.c b/lib/libc_r/uthread/uthread_kern.c
index 4cd8035d7ca..da3c91ff933 100644
--- a/lib/libc_r/uthread/uthread_kern.c
+++ b/lib/libc_r/uthread/uthread_kern.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uthread_kern.c,v 1.20 2002/01/04 03:39:09 fgsch Exp $	*/
+/*	$OpenBSD: uthread_kern.c,v 1.21 2002/02/21 20:57:41 fgsch Exp $	*/
 /*
  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
  * All rights reserved.
@@ -64,6 +64,15 @@ thread_run_switch_hook(pthread_t thread_out, pthread_t thread_in);
 static int	last_tick = 0;
 
 void
+_thread_kern_sched_sig(void)
+{
+	struct pthread	*curthread = _get_curthread();
+
+	curthread->check_pending = 1;
+	_thread_kern_sched(NULL);
+}
+
+void
 _thread_kern_sched(struct sigcontext * scp)
 {
 	struct timespec	ts;
@@ -84,6 +93,15 @@ _thread_kern_sched(struct sigcontext * scp)
 	/* Check if this function was called from the signal handler: */
 	if (scp != NULL) {
 		/*
+		 * The signal handler should have saved the state of
+		 * the current thread. Restore the process signal
+		 * mask.
+		 */
+		if (_thread_sys_sigprocmask(SIG_SETMASK,
+		    &_process_sigmask, NULL) != 0)
+			PANIC("Unable to restore process mask after signal");
+
+		/*
 		 * Copy the signal context to the current thread's jump
 		 * buffer:
 		 */
diff --git a/lib/libc_r/uthread/uthread_sigmask.c b/lib/libc_r/uthread/uthread_sigmask.c
index 03fb4963395..12dd6ec3c69 100644
--- a/lib/libc_r/uthread/uthread_sigmask.c
+++ b/lib/libc_r/uthread/uthread_sigmask.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uthread_sigmask.c,v 1.4 2001/08/21 19:24:53 fgsch Exp $	*/
+/*	$OpenBSD: uthread_sigmask.c,v 1.5 2002/02/21 20:57:41 fgsch Exp $	*/
 /*
  * Copyright (c) 1997 John Birrell <jb@cimlogic.com.au>.
  * All rights reserved.
@@ -42,6 +42,7 @@ int
 pthread_sigmask(int how, const sigset_t *set, sigset_t *oset)
 {
 	struct pthread	*curthread = _get_curthread();
+	sigset_t	sigset;
 	int ret = 0;
 
 	/* Check if the existing signal process mask is to be returned: */
@@ -79,11 +80,22 @@ pthread_sigmask(int how, const sigset_t *set, sigset_t *oset)
 			break;
 		}
 
+		/* Increment the sequence number: */
+		curthread->sigmask_seqno++;
+
 		/*
-		 * Dispatch signals to the running thread that are pending
-		 * and now unblocked:
+		 * Check  if there are pending signals for the running
+		 * thread or process that aren't blocked:
 		 */
-		_dispatch_signals();
+		sigset = curthread->sigpend;
+		sigset |= _process_sigpending;
+		sigset &= ~curthread->sigmask;
+		if (sigset != 0)
+			/*
+			 * Call the kernel scheduler which will safely
+			 * install a signal frame for the running thread:
+			 */
+			_thread_kern_sched_sig();
 	}
 
 	/* Return the completion status: */
diff --git a/lib/libc_r/uthread/uthread_sigwait.c b/lib/libc_r/uthread/uthread_sigwait.c
index 1ae76ab1926..0d1bf618be1 100644
--- a/lib/libc_r/uthread/uthread_sigwait.c
+++ b/lib/libc_r/uthread/uthread_sigwait.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uthread_sigwait.c,v 1.9 2001/08/21 19:24:53 fgsch Exp $	*/
+/*	$OpenBSD: uthread_sigwait.c,v 1.10 2002/02/21 20:57:41 fgsch Exp $	*/
 /*
  * Copyright (c) 1997 John Birrell <jb@cimlogic.com.au>.
  * All rights reserved.
@@ -47,7 +47,6 @@ sigwait(const sigset_t * set, int *sig)
 	sigset_t	tempset, waitset;
 	struct sigaction act;
 	
-	/* This is a cancellation point: */
 	_thread_enter_cancellation_point();
 
 	/*
@@ -55,10 +54,9 @@ sigwait(const sigset_t * set, int *sig)
 	 */
 	act.sa_handler = (void (*) ()) _thread_sig_handler;
 	act.sa_flags = SA_RESTART;
-	act.sa_mask = *set;
 
-	/* Ensure the scheduling signal is masked: */
-	sigaddset(&act.sa_mask, _SCHED_SIGNAL);
+	/* Ensure the signal handler cannot be interrupted by other signals: */
+	sigfillset(&act.sa_mask);
 
 	/*
 	 * Initialize the set of signals that will be waited on:
@@ -73,26 +71,36 @@ sigwait(const sigset_t * set, int *sig)
 	sigdelset(&waitset, SIGINFO);
 
 	/* Check to see if a pending signal is in the wait mask. */
-	if ((tempset = (curthread->sigpend & waitset)) != 0) {
+	tempset = curthread->sigpend;
+	tempset |= _process_sigpending;
+	tempset &= waitset;
+	if (tempset != 0) {
 		/* Enter a loop to find a pending signal: */
 		for (i = 1; i < NSIG; i++) {
-			if (sigismember (&tempset, i))
+			if (sigismember(&tempset, i))
 				break;
 		}
 
 		/* Clear the pending signal: */
-		sigdelset(&curthread->sigpend,i);
+		if (sigismember(&curthread->sigpend, i))
+			sigdelset(&curthread->sigpend, i);
+		else
+			sigdelset(&_process_sigpending, i);
 
 		/* Return the signal number to the caller: */
 		*sig = i;
 
-		/* No longer in a cancellation point: */
 		_thread_leave_cancellation_point();
-
 		return (0);
 	}
 
 	/*
+	 * Access the _thread_dfl_count array under the protection of signal
+	 * deferral.
+	 */
+	_thread_kern_sig_defer();
+
+	/*
 	 * Enter a loop to find the signals that are SIG_DFL.  For
 	 * these signals we must install a dummy signal handler in
 	 * order for the kernel to pass them in to us.  POSIX says
@@ -102,15 +110,23 @@ sigwait(const sigset_t * set, int *sig)
 	 * mask because a subsequent sigaction could enable an
 	 * ignored signal.
 	 */
+	sigemptyset(&tempset);
 	for (i = 1; i < NSIG; i++) {
 		if (sigismember(&waitset, i) &&
 		    (_thread_sigact[i - 1].sa_handler == SIG_DFL)) {
-			if (_thread_sys_sigaction(i,&act,NULL) != 0)
-				ret = -1;
+			_thread_dfl_count[i]++;
+			sigaddset(&tempset, i);
+			if (_thread_dfl_count[i] == 1) {
+				if (_thread_sys_sigaction(i, &act, NULL) != 0)
+					ret = -1;
+			}
 		}
 	}
-	if (ret == 0) {
 
+	/* Done accessing _thread_dfl_count for now. */
+	_thread_kern_sig_undefer();
+
+	if (ret == 0) {
 		/*
 		 * Save the wait signal mask.  The wait signal
 		 * mask is independent of the threads signal mask
@@ -131,17 +147,28 @@ sigwait(const sigset_t * set, int *sig)
 		curthread->data.sigwait = NULL;
 	}
 
+	/*
+	 * Access the _thread_dfl_count array under the protection of signal 
+	 * deferral.
+	 */
+	_thread_kern_sig_defer();
+
 	/* Restore the sigactions: */
 	act.sa_handler = SIG_DFL;
 	for (i = 1; i < NSIG; i++) {
-		if (sigismember(&waitset, i) &&
-		    (_thread_sigact[i - 1].sa_handler == SIG_DFL)) {
-			if (_thread_sys_sigaction(i,&act,NULL) != 0)
-				ret = -1;
+		if (sigismember(&tempset, i)) {
+			_thread_dfl_count[i]--;
+			if ((_thread_sigact[i - 1].sa_handler == SIG_DFL) &&
+			    (_thread_dfl_count[i] == 0)) {
+				if (_thread_sys_sigaction(i, &act, NULL) != 0)
+					ret = -1;
+			}
 		}
 	}
 
-	/* No longer in a cancellation point: */
+	/* Done accessing _thread_dfl_count. */
+	_thread_kern_sig_undefer();
+
 	_thread_leave_cancellation_point();
 
 	/* Return the completion status: */