Fix handling of svr4_sigsets, which are implemented in SysVR4 as a sequence

of 4 longs used as a bitmask.  sv4r4_sigfillset has been broken for a
while, probably since rev 1.5.

This patch fixes SVR4_NSIG (i.e.: sets it to the actual number of signals,
instead of the number of bits in the mask) because some SysVR4 clients
honestly seem to care about whether bits in the signal mask are set for
non-existant signals.

Additionally, the svr4_sigfillset macro has been replaced by a
fully fledged function, because the macro didn't actually work
(it returned an all-ones mask, but we don't want that:  we want 0's
set where FreeBSD doesn't actually have a signal which is the same
as an SysVR4 signal, for example).

SysVR4 clients can now successfully ignore signals, although catching
them remains problematic (see commit log message for rev1.13 of
sys/i386/svr4/svr4_machdep.c for more info).

4 files changed, 102 insertions, 30 deletions

diff --git a/sys/compat/svr4/svr4_signal.c b/sys/compat/svr4/svr4_signal.c
index 125c0c5..821f62c 100644
--- a/sys/compat/svr4/svr4_signal.c
+++ b/sys/compat/svr4/svr4_signal.c
@@ -46,7 +46,6 @@
 #define	svr4_sigmask(n)		(1 << (((n) - 1) & 31))
 #define	svr4_sigword(n)		(((n) - 1) >> 5)
 #define svr4_sigemptyset(s)	memset((s), 0, sizeof(*(s)))
-#define svr4_sigfillset(s)	memset((s), 0xffffffff, sizeof(*(s)))
 #define	svr4_sigismember(s, n)	((s)->bits[svr4_sigword(n)] & svr4_sigmask(n))
 #define	svr4_sigaddset(s, n)	((s)->bits[svr4_sigword(n)] |= svr4_sigmask(n))
 
@@ -54,6 +53,7 @@ void svr4_to_bsd_sigaction __P((const struct svr4_sigaction *,
 				struct sigaction *));
 void bsd_to_svr4_sigaction __P((const struct sigaction *,
 				struct svr4_sigaction *));
+void svr4_sigfillset __P((svr4_sigset_t *));
 
 int bsd_to_svr4_sig[SVR4_SIGTBLSZ] = {
 	SVR4_SIGHUP,
@@ -124,6 +124,18 @@ int svr4_to_bsd_sig[SVR4_SIGTBLSZ] = {
 };
 
 void
+svr4_sigfillset(s)
+	svr4_sigset_t *s;
+{
+	int i;
+
+	svr4_sigemptyset(s);
+	for (i = 0; i < SVR4_NSIG; i++) 
+		if (svr4_to_bsd_sig[i] != 0)
+			svr4_sigaddset(s, i);
+}
+
+void
 svr4_to_bsd_sigset(sss, bss)
 	const svr4_sigset_t *sss;
 	sigset_t *bss;
@@ -131,17 +143,12 @@ svr4_to_bsd_sigset(sss, bss)
 	int i, newsig;
 
 	SIGEMPTYSET(*bss);
-	bss->__bits[0] = sss->bits[0] & ~((1U << SVR4_SIGTBLSZ) - 1);
-	bss->__bits[1] = sss->bits[1];
-	bss->__bits[2] = sss->bits[2];
-	bss->__bits[3] = sss->bits[3];
-	for (i = 1; i <= SVR4_SIGTBLSZ; i++) {
-		if (svr4_sigismember(sss, i)) {
-			newsig = svr4_to_bsd_sig[_SIG_IDX(i)];
+	for (i = 0; i < SVR4_NSIG; i++)
+		if (svr4_sigismember(sss, i + 1)) {
+			newsig = svr4_to_bsd_sig[i];
 			if (newsig)
 				SIGADDSET(*bss, newsig);
 		}
-	}
 }
 
 void
@@ -259,6 +266,10 @@ svr4_sys_sigaction(p, uap)
 	caddr_t sg;
 	int error;
 
+	DPRINTF(("@@@ svr4_sys_sigaction(%d, %d, %d)\n", p->p_pid,
+			SCARG(uap, signum),
+			SVR4_SVR42BSD_SIG(SCARG(uap, signum))));
+	
 	sg = stackgap_init();
 	nisa = SCARG(uap, nsa);
 	oisa = SCARG(uap, osa);
@@ -278,6 +289,16 @@ svr4_sys_sigaction(p, uap)
 	} else
 		nbsa = NULL;
 
+#if defined(DEBUG_SVR4)
+	{
+		int i;
+		for (i = 0; i < 4; i++) 
+			DPRINTF(("\tssa_mask[%d] = %lx\n", i,
+						nisa->ssa_mask.bits[i]));
+		DPRINTF(("\tssa_handler = %lx\n", nisa->ssa_handler));
+	}
+#endif
+
 	SCARG(&sa, sig) = SVR4_SVR42BSD_SIG(SCARG(uap, signum));
 	SCARG(&sa, act) = nbsa;
 	SCARG(&sa, oact) = obsa;
@@ -353,11 +374,12 @@ svr4_sys_signal(p, uap)
 	struct svr4_sys_signal_args *uap;
 {
 	int signum;
-	int error, *retval;
+	int error, *retval = p->p_retval;
 	caddr_t sg = stackgap_init();
 
+	DPRINTF(("@@@ svr4_sys_signal(%d)\n", p->p_pid));
+
 	signum = SVR4_SVR42BSD_SIG(SVR4_SIGNO(SCARG(uap, signum)));
-	retval = p->p_retval;
 	if (signum <= 0 || signum > SVR4_NSIG)
 		return (EINVAL);
 
@@ -530,6 +552,7 @@ svr4_sys_sigpending(p, uap)
 	int *retval;
 	svr4_sigset_t sss;
 
+	DPRINTF(("@@@ svr4_sys_sigpending(%d)\n", p->p_pid));
 	retval = p->p_retval;
 	switch (SCARG(uap, what)) {
 	case 1:	/* sigpending */
@@ -542,6 +565,13 @@ svr4_sys_sigpending(p, uap)
 
 	case 2:	/* sigfillset */
 		svr4_sigfillset(&sss);
+#if defined(DEBUG_SVR4)
+		{
+			int i;
+			for (i = 0; i < 4; i++)
+				DPRINTF(("new sigset[%d] = %lx\n", i, (long)sss.bits[i]));
+		}
+#endif
 		break;
 
 	default:
@@ -605,9 +635,15 @@ svr4_sys_context(p, uap)
 		DPRINTF(("setcontext(%p)\n", uap->uc));
 		if ((error = copyin(uap->uc, &uc, sizeof(uc))) != 0)
 			return error;
-		DPRINTF(("uc_flags = %x\n", uc.uc_flags));
-		DPRINTF(("uc_sigmask = %x\n", uc.uc_sigmask));
-
+		DPRINTF(("uc_flags = %lx\n", uc.uc_flags));
+#if defined(DEBUG_SVR4)
+		{
+			int i;
+			for (i = 0; i < 4; i++)
+				DPRINTF(("uc_sigmask[%d] = %lx\n", i,
+							uc.uc_sigmask.bits[i]));
+		}
+#endif
 		return svr4_setcontext(p, &uc);
 
 	default:
diff --git a/sys/compat/svr4/svr4_signal.h b/sys/compat/svr4/svr4_signal.h
index b7bb132..1fdc3ab 100644
--- a/sys/compat/svr4/svr4_signal.h
+++ b/sys/compat/svr4/svr4_signal.h
@@ -68,7 +68,7 @@
 #define	SVR4_SIGPROF	29
 #define	SVR4_SIGXCPU	30
 #define	SVR4_SIGXFSZ	31
-#define SVR4_NSIG	128
+#define SVR4_NSIG	32
 #define SVR4_SIGTBLSZ	31
 
 #define	SVR4_SIGNO_MASK		0x00FF
diff --git a/sys/svr4/svr4_signal.c b/sys/svr4/svr4_signal.c
index 125c0c5..821f62c 100644
--- a/sys/svr4/svr4_signal.c
+++ b/sys/svr4/svr4_signal.c
@@ -46,7 +46,6 @@
 #define	svr4_sigmask(n)		(1 << (((n) - 1) & 31))
 #define	svr4_sigword(n)		(((n) - 1) >> 5)
 #define svr4_sigemptyset(s)	memset((s), 0, sizeof(*(s)))
-#define svr4_sigfillset(s)	memset((s), 0xffffffff, sizeof(*(s)))
 #define	svr4_sigismember(s, n)	((s)->bits[svr4_sigword(n)] & svr4_sigmask(n))
 #define	svr4_sigaddset(s, n)	((s)->bits[svr4_sigword(n)] |= svr4_sigmask(n))
 
@@ -54,6 +53,7 @@ void svr4_to_bsd_sigaction __P((const struct svr4_sigaction *,
 				struct sigaction *));
 void bsd_to_svr4_sigaction __P((const struct sigaction *,
 				struct svr4_sigaction *));
+void svr4_sigfillset __P((svr4_sigset_t *));
 
 int bsd_to_svr4_sig[SVR4_SIGTBLSZ] = {
 	SVR4_SIGHUP,
@@ -124,6 +124,18 @@ int svr4_to_bsd_sig[SVR4_SIGTBLSZ] = {
 };
 
 void
+svr4_sigfillset(s)
+	svr4_sigset_t *s;
+{
+	int i;
+
+	svr4_sigemptyset(s);
+	for (i = 0; i < SVR4_NSIG; i++) 
+		if (svr4_to_bsd_sig[i] != 0)
+			svr4_sigaddset(s, i);
+}
+
+void
 svr4_to_bsd_sigset(sss, bss)
 	const svr4_sigset_t *sss;
 	sigset_t *bss;
@@ -131,17 +143,12 @@ svr4_to_bsd_sigset(sss, bss)
 	int i, newsig;
 
 	SIGEMPTYSET(*bss);
-	bss->__bits[0] = sss->bits[0] & ~((1U << SVR4_SIGTBLSZ) - 1);
-	bss->__bits[1] = sss->bits[1];
-	bss->__bits[2] = sss->bits[2];
-	bss->__bits[3] = sss->bits[3];
-	for (i = 1; i <= SVR4_SIGTBLSZ; i++) {
-		if (svr4_sigismember(sss, i)) {
-			newsig = svr4_to_bsd_sig[_SIG_IDX(i)];
+	for (i = 0; i < SVR4_NSIG; i++)
+		if (svr4_sigismember(sss, i + 1)) {
+			newsig = svr4_to_bsd_sig[i];
 			if (newsig)
 				SIGADDSET(*bss, newsig);
 		}
-	}
 }
 
 void
@@ -259,6 +266,10 @@ svr4_sys_sigaction(p, uap)
 	caddr_t sg;
 	int error;
 
+	DPRINTF(("@@@ svr4_sys_sigaction(%d, %d, %d)\n", p->p_pid,
+			SCARG(uap, signum),
+			SVR4_SVR42BSD_SIG(SCARG(uap, signum))));
+	
 	sg = stackgap_init();
 	nisa = SCARG(uap, nsa);
 	oisa = SCARG(uap, osa);
@@ -278,6 +289,16 @@ svr4_sys_sigaction(p, uap)
 	} else
 		nbsa = NULL;
 
+#if defined(DEBUG_SVR4)
+	{
+		int i;
+		for (i = 0; i < 4; i++) 
+			DPRINTF(("\tssa_mask[%d] = %lx\n", i,
+						nisa->ssa_mask.bits[i]));
+		DPRINTF(("\tssa_handler = %lx\n", nisa->ssa_handler));
+	}
+#endif
+
 	SCARG(&sa, sig) = SVR4_SVR42BSD_SIG(SCARG(uap, signum));
 	SCARG(&sa, act) = nbsa;
 	SCARG(&sa, oact) = obsa;
@@ -353,11 +374,12 @@ svr4_sys_signal(p, uap)
 	struct svr4_sys_signal_args *uap;
 {
 	int signum;
-	int error, *retval;
+	int error, *retval = p->p_retval;
 	caddr_t sg = stackgap_init();
 
+	DPRINTF(("@@@ svr4_sys_signal(%d)\n", p->p_pid));
+
 	signum = SVR4_SVR42BSD_SIG(SVR4_SIGNO(SCARG(uap, signum)));
-	retval = p->p_retval;
 	if (signum <= 0 || signum > SVR4_NSIG)
 		return (EINVAL);
 
@@ -530,6 +552,7 @@ svr4_sys_sigpending(p, uap)
 	int *retval;
 	svr4_sigset_t sss;
 
+	DPRINTF(("@@@ svr4_sys_sigpending(%d)\n", p->p_pid));
 	retval = p->p_retval;
 	switch (SCARG(uap, what)) {
 	case 1:	/* sigpending */
@@ -542,6 +565,13 @@ svr4_sys_sigpending(p, uap)
 
 	case 2:	/* sigfillset */
 		svr4_sigfillset(&sss);
+#if defined(DEBUG_SVR4)
+		{
+			int i;
+			for (i = 0; i < 4; i++)
+				DPRINTF(("new sigset[%d] = %lx\n", i, (long)sss.bits[i]));
+		}
+#endif
 		break;
 
 	default:
@@ -605,9 +635,15 @@ svr4_sys_context(p, uap)
 		DPRINTF(("setcontext(%p)\n", uap->uc));
 		if ((error = copyin(uap->uc, &uc, sizeof(uc))) != 0)
 			return error;
-		DPRINTF(("uc_flags = %x\n", uc.uc_flags));
-		DPRINTF(("uc_sigmask = %x\n", uc.uc_sigmask));
-
+		DPRINTF(("uc_flags = %lx\n", uc.uc_flags));
+#if defined(DEBUG_SVR4)
+		{
+			int i;
+			for (i = 0; i < 4; i++)
+				DPRINTF(("uc_sigmask[%d] = %lx\n", i,
+							uc.uc_sigmask.bits[i]));
+		}
+#endif
 		return svr4_setcontext(p, &uc);
 
 	default:
diff --git a/sys/svr4/svr4_signal.h b/sys/svr4/svr4_signal.h
index b7bb132..1fdc3ab 100644
--- a/sys/svr4/svr4_signal.h
+++ b/sys/svr4/svr4_signal.h
@@ -68,7 +68,7 @@
 #define	SVR4_SIGPROF	29
 #define	SVR4_SIGXCPU	30
 #define	SVR4_SIGXFSZ	31
-#define SVR4_NSIG	128
+#define SVR4_NSIG	32
 #define SVR4_SIGTBLSZ	31
 
 #define	SVR4_SIGNO_MASK		0x00FF