Remove the now-unused NET_{LOCK,UNLOCK,ASSERT}_GIANT() macros, which

previously conditionally acquired Giant based on debug.mpsafenet.  As that
has now been removed, they are no longer required.  Removing them
significantly simplifies error-handling in the socket layer, eliminated
quite a bit of unwinding of locking in error cases.

While here clean up the now unneeded opt_net.h, which previously was used
for the NET_WITH_GIANT kernel option.  Clean up some related gotos for
consistency.

Reviewed by:	bz, csjp
Tested by:	kris
Approved by:	re (kensmith)

5 files changed, 25 insertions, 107 deletions

diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c
index 29a3f9a..ef1e0e1 100644
--- a/sys/kern/kern_descrip.c
+++ b/sys/kern/kern_descrip.c
@@ -2098,8 +2098,6 @@ fgetsock(struct thread *td, int fd, struct socket **spp, u_int *fflagp)
 	struct file *fp;
 	int error;
 
-	NET_ASSERT_GIANT();
-
 	*spp = NULL;
 	if (fflagp != NULL)
 		*fflagp = 0;
@@ -2129,7 +2127,6 @@ void
 fputsock(struct socket *so)
 {
 
-	NET_ASSERT_GIANT();
 	ACCEPT_LOCK();
 	SOCK_LOCK(so);
 	sorele(so);
diff --git a/sys/kern/kern_poll.c b/sys/kern/kern_poll.c
index fa5d58a..a908f00 100644
--- a/sys/kern/kern_poll.c
+++ b/sys/kern/kern_poll.c
@@ -329,7 +329,6 @@ ether_poll(int count)
 {
 	int i;
 
-	NET_LOCK_GIANT();
 	mtx_lock(&poll_mtx);
 
 	if (count > poll_each_burst)
@@ -339,7 +338,6 @@ ether_poll(int count)
 		pr[i].handler(pr[i].ifp, POLL_ONLY, count);
 
 	mtx_unlock(&poll_mtx);
-	NET_UNLOCK_GIANT();
 }
 
 /*
@@ -366,8 +364,6 @@ netisr_pollmore()
 	struct timeval t;
 	int kern_load;
 
-	NET_ASSERT_GIANT();
-
 	mtx_lock(&poll_mtx);
 	phase = 5;
 	if (residual_burst > 0) {
@@ -417,8 +413,6 @@ netisr_poll(void)
 	int i, cycles;
 	enum poll_cmd arg = POLL_ONLY;
 
-	NET_ASSERT_GIANT();
-
 	mtx_lock(&poll_mtx);
 	phase = 3;
 	if (residual_burst == 0) { /* first call in this tick */
@@ -456,8 +450,6 @@ ether_poll_register(poll_handler_t *h, struct ifnet *ifp)
 	KASSERT(h != NULL, ("%s: handler is NULL", __func__));
 	KASSERT(ifp != NULL, ("%s: ifp is NULL", __func__));
 
-	NET_ASSERT_GIANT();
-
 	mtx_lock(&poll_mtx);
 	if (poll_handlers >= POLL_LIST_LEN) {
 		/*
@@ -504,7 +496,6 @@ ether_poll_deregister(struct ifnet *ifp)
 
 	KASSERT(ifp != NULL, ("%s: ifp is NULL", __func__));
 
-	NET_ASSERT_GIANT();
 	mtx_lock(&poll_mtx);
 
 	for (i = 0 ; i < poll_handlers ; i++)
@@ -547,7 +538,6 @@ poll_switch(SYSCTL_HANDLER_ARGS)
 
 	polling = val;
 
-	NET_LOCK_GIANT();
 	IFNET_RLOCK();
 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
 		if (ifp->if_capabilities & IFCAP_POLLING) {
@@ -565,7 +555,6 @@ poll_switch(SYSCTL_HANDLER_ARGS)
 		}
 	}
 	IFNET_RUNLOCK();
-	NET_UNLOCK_GIANT();
 
 	log(LOG_ERR, "kern.polling.enable is deprecated. Use ifconfig(8)");
 
diff --git a/sys/kern/sys_socket.c b/sys/kern/sys_socket.c
index be230cb..9229658 100644
--- a/sys/kern/sys_socket.c
+++ b/sys/kern/sys_socket.c
@@ -73,21 +73,16 @@ soo_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
     int flags, struct thread *td)
 {
 	struct socket *so = fp->f_data;
+#ifdef MAC
 	int error;
 
-	NET_LOCK_GIANT();
-#ifdef MAC
 	SOCK_LOCK(so);
 	error = mac_check_socket_receive(active_cred, so);
 	SOCK_UNLOCK(so);
-	if (error) {
-		NET_UNLOCK_GIANT();
+	if (error)
 		return (error);
-	}
 #endif
-	error = soreceive(so, 0, uio, 0, 0, 0);
-	NET_UNLOCK_GIANT();
-	return (error);
+	return (soreceive(so, 0, uio, 0, 0, 0));
 }
 
 /* ARGSUSED */
@@ -98,15 +93,12 @@ soo_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
 	struct socket *so = fp->f_data;
 	int error;
 
-	NET_LOCK_GIANT();
 #ifdef MAC
 	SOCK_LOCK(so);
 	error = mac_check_socket_send(active_cred, so);
 	SOCK_UNLOCK(so);
-	if (error) {
-		NET_UNLOCK_GIANT();
+	if (error)
 		return (error);
-	}
 #endif
 	error = sosend(so, 0, uio, 0, 0, 0, uio->uio_td);
 	if (error == EPIPE && (so->so_options & SO_NOSIGPIPE) == 0) {
@@ -114,7 +106,6 @@ soo_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
 		psignal(uio->uio_td->td_proc, SIGPIPE);
 		PROC_UNLOCK(uio->uio_td->td_proc);
 	}
-	NET_UNLOCK_GIANT();
 	return (error);
 }
 
@@ -125,9 +116,7 @@ soo_ioctl(struct file *fp, u_long cmd, void *data, struct ucred *active_cred,
 	struct socket *so = fp->f_data;
 	int error = 0;
 
-	NET_LOCK_GIANT();
 	switch (cmd) {
-
 	case FIONBIO:
 		SOCK_LOCK(so);
 		if (*(int *)data)
@@ -207,8 +196,7 @@ soo_ioctl(struct file *fp, u_long cmd, void *data, struct ucred *active_cred,
 			    (so, cmd, data, 0, td));
 		break;
 	}
-	NET_UNLOCK_GIANT();
-	return(error);
+	return (error);
 }
 
 int
@@ -216,22 +204,16 @@ soo_poll(struct file *fp, int events, struct ucred *active_cred,
     struct thread *td)
 {
 	struct socket *so = fp->f_data;
+#ifdef MAC
 	int error;
 
-	NET_LOCK_GIANT();
-#ifdef MAC
 	SOCK_LOCK(so);
 	error = mac_check_socket_poll(active_cred, so);
 	SOCK_UNLOCK(so);
-	if (error) {
-		NET_UNLOCK_GIANT();
+	if (error)
 		return (error);
-	}
 #endif
-	error = sopoll(so, events, fp->f_cred, td);
-	NET_UNLOCK_GIANT();
-
-	return (error);
+	return (sopoll(so, events, fp->f_cred, td));
 }
 
 int
@@ -239,19 +221,18 @@ soo_stat(struct file *fp, struct stat *ub, struct ucred *active_cred,
     struct thread *td)
 {
 	struct socket *so = fp->f_data;
+#ifdef MAC
 	int error;
+#endif
 
 	bzero((caddr_t)ub, sizeof (*ub));
 	ub->st_mode = S_IFSOCK;
-	NET_LOCK_GIANT();
 #ifdef MAC
 	SOCK_LOCK(so);
 	error = mac_check_socket_stat(active_cred, so);
 	SOCK_UNLOCK(so);
-	if (error) {
-		NET_UNLOCK_GIANT();
+	if (error)
 		return (error);
-	}
 #endif
 	/*
 	 * If SBS_CANTRCVMORE is set, but there's still data left in the
@@ -269,9 +250,7 @@ soo_stat(struct file *fp, struct stat *ub, struct ucred *active_cred,
 	ub->st_size = so->so_rcv.sb_cc - so->so_rcv.sb_ctl;
 	ub->st_uid = so->so_cred->cr_uid;
 	ub->st_gid = so->so_cred->cr_gid;
-	error = (*so->so_proto->pr_usrreqs->pru_sense)(so, ub);
-	NET_UNLOCK_GIANT();
-	return (error);
+	return (*so->so_proto->pr_usrreqs->pru_sense)(so, ub);
 }
 
 /*
@@ -287,13 +266,11 @@ soo_close(struct file *fp, struct thread *td)
 	int error = 0;
 	struct socket *so;
 
-	NET_LOCK_GIANT();
 	so = fp->f_data;
 	fp->f_ops = &badfileops;
 	fp->f_data = NULL;
 
 	if (so)
 		error = soclose(so);
-	NET_UNLOCK_GIANT();
 	return (error);
 }
diff --git a/sys/kern/uipc_domain.c b/sys/kern/uipc_domain.c
index 2a199a4..4c326d3 100644
--- a/sys/kern/uipc_domain.c
+++ b/sys/kern/uipc_domain.c
@@ -453,8 +453,6 @@ pfslowtimo(void *arg)
 	struct domain *dp;
 	struct protosw *pr;
 
-	NET_ASSERT_GIANT();
-
 	for (dp = domains; dp; dp = dp->dom_next)
 		for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++)
 			if (pr->pr_slowtimo)
@@ -468,8 +466,6 @@ pffasttimo(void *arg)
 	struct domain *dp;
 	struct protosw *pr;
 
-	NET_ASSERT_GIANT();
-
 	for (dp = domains; dp; dp = dp->dom_next)
 		for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++)
 			if (pr->pr_fasttimo)
diff --git a/sys/kern/uipc_syscalls.c b/sys/kern/uipc_syscalls.c
index ca770b8..7c874ff 100644
--- a/sys/kern/uipc_syscalls.c
+++ b/sys/kern/uipc_syscalls.c
@@ -175,10 +175,8 @@ socket(td, uap)
 	if (error)
 		return (error);
 	/* An extra reference on `fp' has been held for us by falloc(). */
-	NET_LOCK_GIANT();
 	error = socreate(uap->domain, &so, uap->type, uap->protocol,
 	    td->td_ucred, td);
-	NET_UNLOCK_GIANT();
 	if (error) {
 		fdclose(fdp, fp, fd, td);
 	} else {
@@ -225,25 +223,22 @@ kern_bind(td, fd, sa)
 	struct file *fp;
 	int error;
 
-	NET_LOCK_GIANT();
 	error = getsock(td->td_proc->p_fd, fd, &fp, NULL);
 	if (error)
-		goto done2;
+		return (error);
 	so = fp->f_data;
 #ifdef MAC
 	SOCK_LOCK(so);
 	error = mac_check_socket_bind(td->td_ucred, so, sa);
 	SOCK_UNLOCK(so);
 	if (error)
-		goto done1;
+		goto done;
 #endif
 	error = sobind(so, sa, td);
 #ifdef MAC
-done1:
+done:
 #endif
 	fdrop(fp, td);
-done2:
-	NET_UNLOCK_GIANT();
 	return (error);
 }
 
@@ -260,7 +255,6 @@ listen(td, uap)
 	struct file *fp;
 	int error;
 
-	NET_LOCK_GIANT();
 	error = getsock(td->td_proc->p_fd, uap->s, &fp, NULL);
 	if (error == 0) {
 		so = fp->f_data;
@@ -277,7 +271,6 @@ done:
 #endif
 		fdrop(fp, td);
 	}
-	NET_UNLOCK_GIANT();
 	return(error);
 }
 
@@ -357,10 +350,9 @@ kern_accept(struct thread *td, int s, struct sockaddr **name,
 	}
 
 	fdp = td->td_proc->p_fd;
-	NET_LOCK_GIANT();
 	error = getsock(fdp, s, &headfp, &fflag);
 	if (error)
-		goto done2;
+		return (error);
 	head = headfp->f_data;
 	if ((head->so_options & SO_ACCEPTCONN) == 0) {
 		error = EINVAL;
@@ -491,8 +483,6 @@ done:
 	if (nfp != NULL)
 		fdrop(nfp, td);
 	fdrop(headfp, td);
-done2:
-	NET_UNLOCK_GIANT();
 	return (error);
 }
 
@@ -550,10 +540,9 @@ kern_connect(td, fd, sa)
 	int error;
 	int interrupted = 0;
 
-	NET_LOCK_GIANT();
 	error = getsock(td->td_proc->p_fd, fd, &fp, NULL);
 	if (error)
-		goto done2;
+		return (error);
 	so = fp->f_data;
 	if (so->so_state & SS_ISCONNECTING) {
 		error = EALREADY;
@@ -595,8 +584,6 @@ bad:
 		error = EINTR;
 done1:
 	fdrop(fp, td);
-done2:
-	NET_UNLOCK_GIANT();
 	return (error);
 }
 
@@ -623,11 +610,10 @@ socketpair(td, uap)
 		return (error);
 #endif
 
-	NET_LOCK_GIANT();
 	error = socreate(uap->domain, &so1, uap->type, uap->protocol,
 	    td->td_ucred, td);
 	if (error)
-		goto done2;
+		return (error);
 	error = socreate(uap->domain, &so2, uap->type, uap->protocol,
 	    td->td_ucred, td);
 	if (error)
@@ -670,7 +656,7 @@ socketpair(td, uap)
 		goto free4;
 	fdrop(fp1, td);
 	fdrop(fp2, td);
-	goto done2;
+	return (0);
 free4:
 	fdclose(fdp, fp2, sv[1], td);
 	fdrop(fp2, td);
@@ -683,8 +669,6 @@ free2:
 free1:
 	if (so1 != NULL)
 		(void)soclose(so1);
-done2:
-	NET_UNLOCK_GIANT();
 	return (error);
 }
 
@@ -770,10 +754,9 @@ kern_sendit(td, s, mp, flags, control, segflg)
 	struct uio *ktruio = NULL;
 #endif
 
-	NET_LOCK_GIANT();
 	error = getsock(td->td_proc->p_fd, s, &fp, NULL);
 	if (error)
-		goto bad2;
+		return (error);
 	so = (struct socket *)fp->f_data;
 
 #ifdef MAC
@@ -826,8 +809,6 @@ kern_sendit(td, s, mp, flags, control, segflg)
 #endif
 bad:
 	fdrop(fp, td);
-bad2:
-	NET_UNLOCK_GIANT();
 	return (error);
 }
 
@@ -968,12 +949,9 @@ kern_recvit(td, s, mp, fromseg, controlp)
 	if(controlp != NULL)
 		*controlp = 0;
 
-	NET_LOCK_GIANT();
 	error = getsock(td->td_proc->p_fd, s, &fp, NULL);
-	if (error) {
-		NET_UNLOCK_GIANT();
+	if (error)
 		return (error);
-	}
 	so = fp->f_data;
 
 #ifdef MAC
@@ -982,7 +960,6 @@ kern_recvit(td, s, mp, fromseg, controlp)
 	SOCK_UNLOCK(so);
 	if (error) {
 		fdrop(fp, td);
-		NET_UNLOCK_GIANT();
 		return (error);
 	}
 #endif
@@ -998,7 +975,6 @@ kern_recvit(td, s, mp, fromseg, controlp)
 	for (i = 0; i < mp->msg_iovlen; i++, iov++) {
 		if ((auio.uio_resid += iov->iov_len) < 0) {
 			fdrop(fp, td);
-			NET_UNLOCK_GIANT();
 			return (EINVAL);
 		}
 	}
@@ -1094,7 +1070,6 @@ kern_recvit(td, s, mp, fromseg, controlp)
 	}
 out:
 	fdrop(fp, td);
-	NET_UNLOCK_GIANT();
 	if (fromsa)
 		FREE(fromsa, M_SONAME);
 
@@ -1285,14 +1260,12 @@ shutdown(td, uap)
 	struct file *fp;
 	int error;
 
-	NET_LOCK_GIANT();
 	error = getsock(td->td_proc->p_fd, uap->s, &fp, NULL);
 	if (error == 0) {
 		so = fp->f_data;
 		error = soshutdown(so, uap->how);
 		fdrop(fp, td);
 	}
-	NET_UNLOCK_GIANT();
 	return (error);
 }
 
@@ -1349,14 +1322,12 @@ kern_setsockopt(td, s, level, name, val, valseg, valsize)
 		panic("kern_setsockopt called with bad valseg");
 	}
 
-	NET_LOCK_GIANT();
 	error = getsock(td->td_proc->p_fd, s, &fp, NULL);
 	if (error == 0) {
 		so = fp->f_data;
 		error = sosetopt(so, &sopt);
 		fdrop(fp, td);
 	}
-	NET_UNLOCK_GIANT();
 	return(error);
 }
 
@@ -1429,7 +1400,6 @@ kern_getsockopt(td, s, level, name, val, valseg, valsize)
 		panic("kern_getsockopt called with bad valseg");
 	}
 
-	NET_LOCK_GIANT();
 	error = getsock(td->td_proc->p_fd, s, &fp, NULL);
 	if (error == 0) {
 		so = fp->f_data;
@@ -1437,7 +1407,6 @@ kern_getsockopt(td, s, level, name, val, valseg, valsize)
 		*valsize = sopt.sopt_valsize;
 		fdrop(fp, td);
 	}
-	NET_UNLOCK_GIANT();
 	return (error);
 }
 
@@ -1492,10 +1461,9 @@ kern_getsockname(struct thread *td, int fd, struct sockaddr **sa,
 	if (*alen < 0)
 		return (EINVAL);
 
-	NET_LOCK_GIANT();
 	error = getsock(td->td_proc->p_fd, fd, &fp, NULL);
 	if (error)
-		goto done;
+		return (error);
 	so = fp->f_data;
 	*sa = NULL;
 	error = (*so->so_proto->pr_usrreqs->pru_sockaddr)(so, sa);
@@ -1512,8 +1480,6 @@ bad:
 		free(*sa, M_SONAME);
 		*sa = NULL;
 	}
-done:
-	NET_UNLOCK_GIANT();
 	return (error);
 }
 
@@ -1588,14 +1554,13 @@ kern_getpeername(struct thread *td, int fd, struct sockaddr **sa,
 	if (*alen < 0)
 		return (EINVAL);
 
-	NET_LOCK_GIANT();
 	error = getsock(td->td_proc->p_fd, fd, &fp, NULL);
 	if (error)
-		goto done2;
+		return (error);
 	so = fp->f_data;
 	if ((so->so_state & (SS_ISCONNECTED|SS_ISCONFIRMING)) == 0) {
 		error = ENOTCONN;
-		goto done1;
+		goto done;
 	}
 	*sa = NULL;
 	error = (*so->so_proto->pr_usrreqs->pru_peeraddr)(so, sa);
@@ -1611,10 +1576,8 @@ bad:
 		free(*sa, M_SONAME);
 		*sa = NULL;
 	}
-done1:
+done:
 	fdrop(fp, td);
-done2:
-	NET_UNLOCK_GIANT();
 	return (error);
 }
 
@@ -1823,8 +1786,6 @@ kern_sendfile(struct thread *td, struct sendfile_args *uap,
 	int error, hdrlen = 0, mnw = 0;
 	int vfslocked;
 
-	NET_LOCK_GIANT();
-
 	/*
 	 * The file descriptor must be a regular file and have a
 	 * backing VM object.
@@ -2242,8 +2203,6 @@ out:
 	if (m)
 		m_freem(m);
 
-	NET_UNLOCK_GIANT();
-
 	if (error == ERESTART)
 		error = EINTR;