6565817 sigwait can't wait for SIGTSTP

3 files changed, 29 insertions, 22 deletions

diff --git a/usr/src/uts/common/os/sig.c b/usr/src/uts/common/os/sig.c
index 8044529f83..454b9e600f 100644
--- a/usr/src/uts/common/os/sig.c
+++ b/usr/src/uts/common/os/sig.c
@@ -20,16 +20,13 @@
  */
 
 /*
- * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
 /*	  All Rights Reserved  	*/
 
-
-#pragma ident	"%Z%%M%	%I%	%E% SMI"
-
 #include <sys/param.h>
 #include <sys/types.h>
 #include <sys/bitmap.h>
@@ -146,6 +143,7 @@ signal_is_blocked(kthread_t *t, int sig)
  *	the process is single-threaded
  *	the signal is not being traced by /proc
  * 	the signal is not blocked by the process
+ *	the signal is not being accepted via sigwait()
  */
 static int
 sig_discardable(proc_t *p, int sig)
@@ -156,7 +154,8 @@ sig_discardable(proc_t *p, int sig)
 	    (sigismember(&p->p_ignore, sig) &&	/* signal is ignored */
 	    t->t_forw == t &&			/* and single-threaded */
 	    !tracing(p, sig) &&			/* and no /proc tracing */
-	    !signal_is_blocked(t, sig)));	/* and signal not blocked */
+	    !signal_is_blocked(t, sig) &&	/* and signal not blocked */
+	    !sigismember(&t->t_sigwait, sig)));	/* and not being accepted */
 }
 
 /*
@@ -474,6 +473,7 @@ issig_justlooking(void)
 		for (sig = 1; sig < NSIG; sig++) {
 			if (sigismember(&set, sig) &&
 			    (tracing(p, sig) ||
+			    sigismember(&t->t_sigwait, sig) ||
 			    !sigismember(&p->p_ignore, sig))) {
 				/*
 				 * Don't promote a signal that will stop
@@ -622,13 +622,19 @@ issig_forreal(void)
 		 * signal; we cancel lwp->lwp_cursig temporarily before
 		 * calling isjobstop().  The current signal may be reset
 		 * by a debugger while we are stopped in isjobstop().
+		 *
+		 * If the current thread is accepting the signal
+		 * (via sigwait(), sigwaitinfo(), or sigtimedwait()),
+		 * we allow the signal to be accepted, even if it is
+		 * being ignored, and without causing a job control stop.
 		 */
 		if ((sig = lwp->lwp_cursig) != 0) {
 			ext = lwp->lwp_extsig;
 			lwp->lwp_cursig = 0;
 			lwp->lwp_extsig = 0;
-			if (!sigismember(&p->p_ignore, sig) &&
-			    !isjobstop(sig)) {
+			if (sigismember(&t->t_sigwait, sig) ||
+			    (!sigismember(&p->p_ignore, sig) &&
+			    !isjobstop(sig))) {
 				if (p->p_flag & (SEXITLWPS|SKILLED)) {
 					sig = SIGKILL;
 					ext = (p->p_flag & SEXTKILLED) != 0;
@@ -675,14 +681,12 @@ issig_forreal(void)
 		 * then the signals pending for the process as a whole.
 		 */
 		for (;;) {
-			k_sigset_t tsig;
-
-			tsig = t->t_sig;
-			if ((sig = fsig(&tsig, t)) != 0) {
+			if ((sig = fsig(&t->t_sig, t)) != 0) {
 				if (sig == SIGCLD)
 					sigcld_found = 1;
 				toproc = 0;
 				if (tracing(p, sig) ||
+				    sigismember(&t->t_sigwait, sig) ||
 				    !sigismember(&p->p_ignore, sig)) {
 					if (sigismember(&t->t_extsig, sig))
 						ext = 1;
@@ -696,6 +700,7 @@ issig_forreal(void)
 					sigcld_found = 1;
 				toproc = 1;
 				if (tracing(p, sig) ||
+				    sigismember(&t->t_sigwait, sig) ||
 				    !sigismember(&p->p_ignore, sig)) {
 					if (sigismember(&p->p_extsig, sig))
 						ext = 1;
diff --git a/usr/src/uts/common/sys/thread.h b/usr/src/uts/common/sys/thread.h
index 6d112ef065..bb2502679a 100644
--- a/usr/src/uts/common/sys/thread.h
+++ b/usr/src/uts/common/sys/thread.h
@@ -163,6 +163,7 @@ typedef struct _kthread {
 	k_sigset_t	t_sig;		/* signals pending to this process */
 	k_sigset_t	t_extsig;	/* signals sent from another contract */
 	k_sigset_t	t_hold;		/* hold signal bit mask */
+	k_sigset_t	t_sigwait;	/* sigtimedwait() is accepting these */
 	struct	_kthread *t_forw;	/* process's forward thread link */
 	struct	_kthread *t_back;	/* process's backward thread link */
 	struct	_kthread *t_thlink;	/* tid (lwpid) lookup hash link */
diff --git a/usr/src/uts/common/syscall/sigtimedwait.c b/usr/src/uts/common/syscall/sigtimedwait.c
index ad4d79b763..3740fd5d10 100644
--- a/usr/src/uts/common/syscall/sigtimedwait.c
+++ b/usr/src/uts/common/syscall/sigtimedwait.c
@@ -2,9 +2,8 @@
  * CDDL HEADER START
  *
  * The contents of this file are subject to the terms of the
- * Common Development and Distribution License, Version 1.0 only
- * (the "License").  You may not use this file except in compliance
- * with the License.
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
  *
  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  * or http://www.opensolaris.org/os/licensing.
@@ -19,13 +18,12 @@
  *
  * CDDL HEADER END
  */
+
 /*
- * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
-#pragma ident	"%Z%%M%	%I%	%E% SMI"
-
 #include <sys/param.h>
 #include <sys/types.h>
 #include <sys/bitmap.h>
@@ -95,7 +93,6 @@ int
 sigtimedwait(sigset_t *setp, siginfo_t *siginfop, timespec_t *timeoutp)
 {
 	sigset_t set;
-	k_sigset_t kset;
 	k_sigset_t oldmask;
 	kthread_t *t = curthread;
 	klwp_t *lwp = ttolwp(t);
@@ -135,8 +132,8 @@ sigtimedwait(sigset_t *setp, siginfo_t *siginfop, timespec_t *timeoutp)
 	}
 	if (copyin(setp, &set, sizeof (set)))
 		return (set_errno(EFAULT));
-	sigutok(&set, &kset);
-	if (sigisempty(&kset))
+	sigutok(&set, &t->t_sigwait);
+	if (sigisempty(&t->t_sigwait))
 		return (set_errno(EINVAL));
 
 	mutex_enter(&p->p_lock);
@@ -146,7 +143,7 @@ sigtimedwait(sigset_t *setp, siginfo_t *siginfop, timespec_t *timeoutp)
 	 */
 	schedctl_finish_sigblock(t);
 	oldmask = t->t_hold;
-	sigdiffset(&t->t_hold, &kset);
+	sigdiffset(&t->t_hold, &t->t_sigwait);
 
 	/*
 	 * Wait until we take a signal or until
@@ -166,18 +163,21 @@ sigtimedwait(sigset_t *setp, siginfo_t *siginfop, timespec_t *timeoutp)
 
 	if (error) {
 		mutex_exit(&p->p_lock);
+		sigemptyset(&t->t_sigwait);
 		return (set_errno(error));	/* timer expired */
 	}
 	/*
 	 * Don't bother with signal if it is not in request set.
 	 */
-	if (lwp->lwp_cursig == 0 || !sigismember(&kset, lwp->lwp_cursig)) {
+	if (lwp->lwp_cursig == 0 ||
+	    !sigismember(&t->t_sigwait, lwp->lwp_cursig)) {
 		mutex_exit(&p->p_lock);
 		/*
 		 * lwp_cursig is zero if pokelwps() awakened cv_wait_sig().
 		 * This happens if some other thread in this process called
 		 * forkall() or exit().
 		 */
+		sigemptyset(&t->t_sigwait);
 		return (set_errno(EINTR));
 	}
 
@@ -203,5 +203,6 @@ sigtimedwait(sigset_t *setp, siginfo_t *siginfop, timespec_t *timeoutp)
 		siginfofree(lwp->lwp_curinfo);
 		lwp->lwp_curinfo = NULL;
 	}
+	sigemptyset(&t->t_sigwait);
 	return (ret);
 }