First half of implementation of ksiginfo, signal queues, and such. This

gets signals operating based on a TailQ, and is good enough to run X11,
GNOME, and do job control.  There are some intricate parts which could be
more refined to match the sigset_t versions, but those require further
evaluation of directions in which our signal system can expand and contract
to fit our needs.

After this has been in the tree for a while, I will make in kernel API
changes, most notably to trapsignal(9) and sendsig(9), to use ksiginfo
more robustly, such that we can actually pass information with our
(queued) signals to the userland.  That will also result in using a
struct ksiginfo pointer, rather than a signal number, in a lot of
kern_sig.c, to refer to an individual pending signal queue member, but
right now there is no defined behaviour for such.

CODAFS is unfinished in this regard because the logic is unclear in
some places.

Sponsored by:	New Gold Technology
Reviewed by:	bde, tjr, jake [an older version, logic similar]

1 files changed, 36 insertions, 28 deletions

diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index f6fa38b..ada2016 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -1,4 +1,6 @@
 /*
+ * Copyright (c) 2002 New Gold Technoloy.  All rights reserved.
+ * Copyright (c) 2002 Juli Mallett.  All rights reserved.
  * Copyright (c) 1982, 1986, 1989, 1991, 1993
  *	The Regents of the University of California.  All rights reserved.
  * (c) UNIX System Laboratories, Inc.
@@ -70,6 +72,7 @@
 #include <sys/sysctl.h>
 #include <sys/malloc.h>
 #include <sys/unistd.h>
+#include <sys/ksiginfo.h>
 
 #include <machine/cpu.h>
 
@@ -116,6 +119,9 @@ static int	do_coredump = 1;
 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
 	&do_coredump, 0, "Enable/Disable coredumps");
 
+static int stopmask =
+    sigmask(SIGSTOP) | sigmask(SIGTSTP) | sigmask(SIGTTIN) | sigmask(SIGTTOU);
+
 /*
  * Signal properties and actions.
  * The array below categorizes the signals and their default actions
@@ -178,12 +184,12 @@ cursig(struct thread *td)
 
 	PROC_LOCK_ASSERT(p, MA_OWNED);
 	mtx_assert(&sched_lock, MA_NOTOWNED);
-	return (SIGPENDING(p) ? issignal(td) : 0);
+	return (signal_pending(p) ? issignal(td) : 0);
 }
 
 /*
  * Arrange for ast() to handle unmasked pending signals on return to user
- * mode.  This must be called whenever a signal is added to p_siglist or
+ * mode.  This must be called whenever a signal is added to p_sigq or
  * unmasked in p_sigmask.
  */
 void
@@ -194,7 +200,7 @@ signotify(struct proc *p)
 
 	PROC_LOCK_ASSERT(p, MA_OWNED);
 	mtx_lock_spin(&sched_lock);
-	if (SIGPENDING(p)) {
+	if (signal_pending(p)) {
 		p->p_sflag |= PS_NEEDSIGCHK;
 		/* XXXKSE for now punish all KSEs */
 		FOREACH_KSEGRP_IN_PROC(p, kg) {
@@ -341,7 +347,7 @@ kern_sigaction(td, sig, act, oact, old)
 		    (sigprop(sig) & SA_IGNORE &&
 		     ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
 			/* never to be seen again */
-			SIGDELSET(p->p_siglist, sig);
+			signal_delete(p, NULL, sig);
 			if (sig != SIGCONT)
 				/* easier in psignal */
 				SIGADDSET(p->p_sigignore, sig);
@@ -494,7 +500,7 @@ execsigs(p)
 		if (sigprop(sig) & SA_IGNORE) {
 			if (sig != SIGCONT)
 				SIGADDSET(p->p_sigignore, sig);
-			SIGDELSET(p->p_siglist, sig);
+			signal_delete(p, NULL, sig);
 		}
 		ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
 	}
@@ -641,7 +647,7 @@ sigpending(td, uap)
 
 	mtx_lock(&Giant);
 	PROC_LOCK(p);
-	siglist = p->p_siglist;
+	ksiginfo_to_sigset_t(p, &siglist);
 	PROC_UNLOCK(p);
 	mtx_unlock(&Giant);
 	error = copyout(&siglist, uap->set, sizeof(sigset_t));
@@ -664,10 +670,12 @@ osigpending(td, uap)
 	struct osigpending_args *uap;
 {
 	struct proc *p = td->td_proc;
+	sigset_t siglist;
 
 	mtx_lock(&Giant);
 	PROC_LOCK(p);
-	SIG2OSIG(p->p_siglist, td->td_retval[0]);
+	ksiginfo_to_sigset_t(p, &siglist);
+	SIG2OSIG(siglist, td->td_retval[0]);
 	PROC_UNLOCK(p);
 	mtx_unlock(&Giant);
 	return (0);
@@ -1308,7 +1316,7 @@ psignal(p, sig)
 	}
 
 	if (prop & SA_CONT)
-		SIG_STOPSIGMASK(p->p_siglist);
+		signal_delete_mask(p, stopmask);
 
 	if (prop & SA_STOP) {
 		/*
@@ -1321,10 +1329,10 @@ psignal(p, sig)
 		    (p->p_pgrp->pg_jobc == 0) &&
 		    (action == SIG_DFL))
 		        return;
-		SIG_CONTSIGMASK(p->p_siglist);
+		signal_delete_mask(p, sigmask(SIGCONT));
 		p->p_flag &= ~P_CONTINUED;
 	}
-	SIGADDSET(p->p_siglist, sig);
+	signal_add(p, NULL, sig);
 	signotify(p);			/* uses schedlock */
 
 	/*
@@ -1362,10 +1370,10 @@ psignal(p, sig)
 		if (prop & SA_CONT) {
 			/*
 			 * If SIGCONT is default (or ignored), we continue the
-			 * process but don't leave the signal in p_siglist as
-			 * it has no further action.  If SIGCONT is held, we
+			 * process but don't leave the signal in p_sigq as it
+			 * has no further action.  If SIGCONT is held, we
 			 * continue the process and leave the signal in
-			 * p_siglist.  If the process catches SIGCONT, let it
+			 * p_sigq.  If the process catches SIGCONT, let it
 			 * handle the signal itself.  If it isn't waiting on
 			 * an event, it goes back to run state.
 			 * Otherwise, process goes back to sleep state.
@@ -1373,7 +1381,7 @@ psignal(p, sig)
 			p->p_flag &= ~P_STOPPED_SIG;
 			p->p_flag |= P_CONTINUED;
 			if (action == SIG_DFL) {
-				SIGDELSET(p->p_siglist, sig);
+				signal_delete(p, NULL, sig);
 			} else if (action == SIG_CATCH) {
 				/*
 				 * The process wants to catch it so it needs
@@ -1403,7 +1411,7 @@ psignal(p, sig)
 			 * Just make sure the signal STOP bit set.
 			 */
 			p->p_flag |= P_STOPPED_SIG;
-			SIGDELSET(p->p_siglist, sig);
+			signal_delete(p, NULL, sig);
 			goto out;
 		}
 
@@ -1437,7 +1445,7 @@ psignal(p, sig)
 			/*
 			 * Already active, don't need to start again.
 			 */
-			SIGDELSET(p->p_siglist, sig);
+			signal_delete(p, NULL, sig);
 			goto out;
 		}
 		if ((p->p_flag & P_TRACED) || (action != SIG_DFL) ||
@@ -1461,7 +1469,7 @@ psignal(p, sig)
 				mtx_unlock_spin(&sched_lock);
 				stop(p);
 				p->p_xstat = sig;
-				SIGDELSET(p->p_siglist, sig);
+				signal_delete(p, NULL, sig);
 				PROC_LOCK(p->p_pptr);
 				if ((p->p_pptr->p_procsig->ps_flag &
 					PS_NOCLDSTOP) == 0) {
@@ -1478,7 +1486,7 @@ psignal(p, sig)
 		/* NOTREACHED */
 	} else {
 		/* Not in "NORMAL" state. discard the signal. */
-		SIGDELSET(p->p_siglist, sig);
+		signal_delete(p, NULL, sig);
 		goto out;
 	}
 
@@ -1553,7 +1561,7 @@ tdsignal(struct thread *td, int sig, sig_t action)
 			 * be awakened.
 			 */
 			if ((prop & SA_CONT) && action == SIG_DFL) {
-				SIGDELSET(p->p_siglist, sig);
+				signal_delete(p, NULL, sig);
 				return;
 			}
 
@@ -1609,13 +1617,13 @@ issignal(td)
 	for (;;) {
 		int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
 
-		mask = p->p_siglist;
+		ksiginfo_to_sigset_t(p, &mask);
 		SIGSETNAND(mask, p->p_sigmask);
 		if (p->p_flag & P_PPWAIT)
 			SIG_STOPSIGMASK(mask);
 		if (SIGISEMPTY(mask))		/* no signal to send */
 			return (0);
-		sig = sig_ffs(&mask);
+		sig = signal_queued_mask(p, mask);
 		prop = sigprop(sig);
 
 		_STOPEVENT(p, S_SIG, sig);
@@ -1625,7 +1633,7 @@ issignal(td)
 		 * only if P_TRACED was on when they were posted.
 		 */
 		if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) {
-			SIGDELSET(p->p_siglist, sig);
+			signal_delete(p, NULL, sig);
 			continue;
 		}
 		if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) {
@@ -1660,16 +1668,16 @@ issignal(td)
 			 * then it will leave it in p->p_xstat;
 			 * otherwise we just look for signals again.
 			 */
-			SIGDELSET(p->p_siglist, sig);	/* clear old signal */
+			signal_delete(p, NULL, sig);	/* clear old signal */
 			sig = p->p_xstat;
 			if (sig == 0)
 				continue;
 
 			/*
-			 * Put the new signal into p_siglist.  If the
-			 * signal is being masked, look for other signals.
+			 * Put the new signal into p_sigq.  If the signal
+			 * is being masked, look for other signals.
 			 */
-			SIGADDSET(p->p_siglist, sig);
+			psignal(p, sig);
 			if (SIGISMEMBER(p->p_sigmask, sig))
 				continue;
 			signotify(p);
@@ -1759,7 +1767,7 @@ issignal(td)
 			 */
 			return (sig);
 		}
-		SIGDELSET(p->p_siglist, sig);		/* take the signal! */
+		signal_delete(p, NULL, sig);		/* take the signal! */
 	}
 	/* NOTREACHED */
 }
@@ -1800,7 +1808,7 @@ postsig(sig)
 
 	PROC_LOCK_ASSERT(p, MA_OWNED);
 	ps = p->p_sigacts;
-	SIGDELSET(p->p_siglist, sig);
+	signal_delete(p, NULL, sig);
 	action = ps->ps_sigact[_SIG_IDX(sig)];
 #ifdef KTRACE
 	if (KTRPOINT(td, KTR_PSIG))