LSM: shrink the common_audit_data data union

After shrinking the common_audit_data stack usage for private LSM data I'm
not going to shrink the data union.  To do this I'm going to move anything
larger than 2 void * ptrs to it's own structure and require it to be declared
separately on the calling stack.  Thus hot paths which don't need more than
a couple pointer don't have to declare space to hold large unneeded
structures.  I could get this down to one void * by dealing with the key
struct and the struct path.  We'll see if that is helpful after taking care of
networking.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 63 insertions, 42 deletions

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 3861ce4..d85b793 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3517,8 +3517,8 @@ static int selinux_parse_skb_ipv4(struct sk_buff *skb,
 	if (ihlen < sizeof(_iph))
 		goto out;
 
-	ad->u.net.v4info.saddr = ih->saddr;
-	ad->u.net.v4info.daddr = ih->daddr;
+	ad->u.net->v4info.saddr = ih->saddr;
+	ad->u.net->v4info.daddr = ih->daddr;
 	ret = 0;
 
 	if (proto)
@@ -3536,8 +3536,8 @@ static int selinux_parse_skb_ipv4(struct sk_buff *skb,
 		if (th == NULL)
 			break;
 
-		ad->u.net.sport = th->source;
-		ad->u.net.dport = th->dest;
+		ad->u.net->sport = th->source;
+		ad->u.net->dport = th->dest;
 		break;
 	}
 
@@ -3552,8 +3552,8 @@ static int selinux_parse_skb_ipv4(struct sk_buff *skb,
 		if (uh == NULL)
 			break;
 
-		ad->u.net.sport = uh->source;
-		ad->u.net.dport = uh->dest;
+		ad->u.net->sport = uh->source;
+		ad->u.net->dport = uh->dest;
 		break;
 	}
 
@@ -3568,8 +3568,8 @@ static int selinux_parse_skb_ipv4(struct sk_buff *skb,
 		if (dh == NULL)
 			break;
 
-		ad->u.net.sport = dh->dccph_sport;
-		ad->u.net.dport = dh->dccph_dport;
+		ad->u.net->sport = dh->dccph_sport;
+		ad->u.net->dport = dh->dccph_dport;
 		break;
 	}
 
@@ -3596,8 +3596,8 @@ static int selinux_parse_skb_ipv6(struct sk_buff *skb,
 	if (ip6 == NULL)
 		goto out;
 
-	ad->u.net.v6info.saddr = ip6->saddr;
-	ad->u.net.v6info.daddr = ip6->daddr;
+	ad->u.net->v6info.saddr = ip6->saddr;
+	ad->u.net->v6info.daddr = ip6->daddr;
 	ret = 0;
 
 	nexthdr = ip6->nexthdr;
@@ -3617,8 +3617,8 @@ static int selinux_parse_skb_ipv6(struct sk_buff *skb,
 		if (th == NULL)
 			break;
 
-		ad->u.net.sport = th->source;
-		ad->u.net.dport = th->dest;
+		ad->u.net->sport = th->source;
+		ad->u.net->dport = th->dest;
 		break;
 	}
 
@@ -3629,8 +3629,8 @@ static int selinux_parse_skb_ipv6(struct sk_buff *skb,
 		if (uh == NULL)
 			break;
 
-		ad->u.net.sport = uh->source;
-		ad->u.net.dport = uh->dest;
+		ad->u.net->sport = uh->source;
+		ad->u.net->dport = uh->dest;
 		break;
 	}
 
@@ -3641,8 +3641,8 @@ static int selinux_parse_skb_ipv6(struct sk_buff *skb,
 		if (dh == NULL)
 			break;
 
-		ad->u.net.sport = dh->dccph_sport;
-		ad->u.net.dport = dh->dccph_dport;
+		ad->u.net->sport = dh->dccph_sport;
+		ad->u.net->dport = dh->dccph_dport;
 		break;
 	}
 
@@ -3662,13 +3662,13 @@ static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
 	char *addrp;
 	int ret;
 
-	switch (ad->u.net.family) {
+	switch (ad->u.net->family) {
 	case PF_INET:
 		ret = selinux_parse_skb_ipv4(skb, ad, proto);
 		if (ret)
 			goto parse_error;
-		addrp = (char *)(src ? &ad->u.net.v4info.saddr :
-				       &ad->u.net.v4info.daddr);
+		addrp = (char *)(src ? &ad->u.net->v4info.saddr :
+				       &ad->u.net->v4info.daddr);
 		goto okay;
 
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
@@ -3676,8 +3676,8 @@ static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
 		ret = selinux_parse_skb_ipv6(skb, ad, proto);
 		if (ret)
 			goto parse_error;
-		addrp = (char *)(src ? &ad->u.net.v6info.saddr :
-				       &ad->u.net.v6info.daddr);
+		addrp = (char *)(src ? &ad->u.net->v6info.saddr :
+				       &ad->u.net->v6info.daddr);
 		goto okay;
 #endif	/* IPV6 */
 	default:
@@ -3752,6 +3752,7 @@ static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms)
 	struct sk_security_struct *sksec = sk->sk_security;
 	struct common_audit_data ad;
 	struct selinux_audit_data sad = {0,};
+	struct lsm_network_audit net = {0,};
 	u32 tsid = task_sid(task);
 
 	if (sksec->sid == SECINITSID_KERNEL)
@@ -3759,7 +3760,8 @@ static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms)
 
 	COMMON_AUDIT_DATA_INIT(&ad, NET);
 	ad.selinux_audit_data = &sad;
-	ad.u.net.sk = sk;
+	ad.u.net = &net;
+	ad.u.net->sk = sk;
 
 	return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad);
 }
@@ -3838,6 +3840,7 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
 		struct sk_security_struct *sksec = sk->sk_security;
 		struct common_audit_data ad;
 		struct selinux_audit_data sad = {0,};
+		struct lsm_network_audit net = {0,};
 		struct sockaddr_in *addr4 = NULL;
 		struct sockaddr_in6 *addr6 = NULL;
 		unsigned short snum;
@@ -3865,8 +3868,9 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
 					goto out;
 				COMMON_AUDIT_DATA_INIT(&ad, NET);
 				ad.selinux_audit_data = &sad;
-				ad.u.net.sport = htons(snum);
-				ad.u.net.family = family;
+				ad.u.net = &net;
+				ad.u.net->sport = htons(snum);
+				ad.u.net->family = family;
 				err = avc_has_perm(sksec->sid, sid,
 						   sksec->sclass,
 						   SOCKET__NAME_BIND, &ad);
@@ -3899,13 +3903,14 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
 
 		COMMON_AUDIT_DATA_INIT(&ad, NET);
 		ad.selinux_audit_data = &sad;
-		ad.u.net.sport = htons(snum);
-		ad.u.net.family = family;
+		ad.u.net = &net;
+		ad.u.net->sport = htons(snum);
+		ad.u.net->family = family;
 
 		if (family == PF_INET)
-			ad.u.net.v4info.saddr = addr4->sin_addr.s_addr;
+			ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
 		else
-			ad.u.net.v6info.saddr = addr6->sin6_addr;
+			ad.u.net->v6info.saddr = addr6->sin6_addr;
 
 		err = avc_has_perm(sksec->sid, sid,
 				   sksec->sclass, node_perm, &ad);
@@ -3933,6 +3938,7 @@ static int selinux_socket_connect(struct socket *sock, struct sockaddr *address,
 	    sksec->sclass == SECCLASS_DCCP_SOCKET) {
 		struct common_audit_data ad;
 		struct selinux_audit_data sad = {0,};
+		struct lsm_network_audit net = {0,};
 		struct sockaddr_in *addr4 = NULL;
 		struct sockaddr_in6 *addr6 = NULL;
 		unsigned short snum;
@@ -3959,8 +3965,9 @@ static int selinux_socket_connect(struct socket *sock, struct sockaddr *address,
 
 		COMMON_AUDIT_DATA_INIT(&ad, NET);
 		ad.selinux_audit_data = &sad;
-		ad.u.net.dport = htons(snum);
-		ad.u.net.family = sk->sk_family;
+		ad.u.net = &net;
+		ad.u.net->dport = htons(snum);
+		ad.u.net->family = sk->sk_family;
 		err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
 		if (err)
 			goto out;
@@ -4050,11 +4057,13 @@ static int selinux_socket_unix_stream_connect(struct sock *sock,
 	struct sk_security_struct *sksec_new = newsk->sk_security;
 	struct common_audit_data ad;
 	struct selinux_audit_data sad = {0,};
+	struct lsm_network_audit net = {0,};
 	int err;
 
 	COMMON_AUDIT_DATA_INIT(&ad, NET);
 	ad.selinux_audit_data = &sad;
-	ad.u.net.sk = other;
+	ad.u.net = &net;
+	ad.u.net->sk = other;
 
 	err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
 			   sksec_other->sclass,
@@ -4082,10 +4091,12 @@ static int selinux_socket_unix_may_send(struct socket *sock,
 	struct sk_security_struct *osec = other->sk->sk_security;
 	struct common_audit_data ad;
 	struct selinux_audit_data sad = {0,};
+	struct lsm_network_audit net = {0,};
 
 	COMMON_AUDIT_DATA_INIT(&ad, NET);
 	ad.selinux_audit_data = &sad;
-	ad.u.net.sk = other->sk;
+	ad.u.net = &net;
+	ad.u.net->sk = other->sk;
 
 	return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
 			    &ad);
@@ -4122,12 +4133,14 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
 	u32 sk_sid = sksec->sid;
 	struct common_audit_data ad;
 	struct selinux_audit_data sad = {0,};
+	struct lsm_network_audit net = {0,};
 	char *addrp;
 
 	COMMON_AUDIT_DATA_INIT(&ad, NET);
 	ad.selinux_audit_data = &sad;
-	ad.u.net.netif = skb->skb_iif;
-	ad.u.net.family = family;
+	ad.u.net = &net;
+	ad.u.net->netif = skb->skb_iif;
+	ad.u.net->family = family;
 	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
 	if (err)
 		return err;
@@ -4155,6 +4168,7 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 	u32 sk_sid = sksec->sid;
 	struct common_audit_data ad;
 	struct selinux_audit_data sad = {0,};
+	struct lsm_network_audit net = {0,};
 	char *addrp;
 	u8 secmark_active;
 	u8 peerlbl_active;
@@ -4180,8 +4194,9 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 
 	COMMON_AUDIT_DATA_INIT(&ad, NET);
 	ad.selinux_audit_data = &sad;
-	ad.u.net.netif = skb->skb_iif;
-	ad.u.net.family = family;
+	ad.u.net = &net;
+	ad.u.net->netif = skb->skb_iif;
+	ad.u.net->family = family;
 	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
 	if (err)
 		return err;
@@ -4517,6 +4532,7 @@ static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
 	u32 peer_sid;
 	struct common_audit_data ad;
 	struct selinux_audit_data sad = {0,};
+	struct lsm_network_audit net = {0,};
 	u8 secmark_active;
 	u8 netlbl_active;
 	u8 peerlbl_active;
@@ -4535,8 +4551,9 @@ static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
 
 	COMMON_AUDIT_DATA_INIT(&ad, NET);
 	ad.selinux_audit_data = &sad;
-	ad.u.net.netif = ifindex;
-	ad.u.net.family = family;
+	ad.u.net = &net;
+	ad.u.net->netif = ifindex;
+	ad.u.net->family = family;
 	if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
 		return NF_DROP;
 
@@ -4624,6 +4641,7 @@ static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
 	struct sk_security_struct *sksec;
 	struct common_audit_data ad;
 	struct selinux_audit_data sad = {0,};
+	struct lsm_network_audit net = {0,};
 	char *addrp;
 	u8 proto;
 
@@ -4633,8 +4651,9 @@ static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
 
 	COMMON_AUDIT_DATA_INIT(&ad, NET);
 	ad.selinux_audit_data = &sad;
-	ad.u.net.netif = ifindex;
-	ad.u.net.family = family;
+	ad.u.net = &net;
+	ad.u.net->netif = ifindex;
+	ad.u.net->family = family;
 	if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
 		return NF_DROP;
 
@@ -4657,6 +4676,7 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
 	struct sock *sk;
 	struct common_audit_data ad;
 	struct selinux_audit_data sad = {0,};
+	struct lsm_network_audit net = {0,};
 	char *addrp;
 	u8 secmark_active;
 	u8 peerlbl_active;
@@ -4704,8 +4724,9 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
 
 	COMMON_AUDIT_DATA_INIT(&ad, NET);
 	ad.selinux_audit_data = &sad;
-	ad.u.net.netif = ifindex;
-	ad.u.net.family = family;
+	ad.u.net = &net;
+	ad.u.net->netif = ifindex;
+	ad.u.net->family = family;
 	if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
 		return NF_DROP;