[PATCH 0/2] constify net_protocol structures

[PATCH 0/2] constify net_protocol structures

[Julia Lawall]

The net_protocol structure is only passed as the first argument to
inet_add_protocol or inet_del_protocol, both of which are declared
as const.  Thus the net_protocol structure itself can be const.

Done with the help of Coccinelle.

---

 net/ipv4/af_inet.c |    4 ++--
 net/l2tp/l2tp_ip.c |    2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

[PATCH 1/2] ipv4: constify net_protocol structures

[Julia Lawall]

The net_protocol structures are only passed as the first argument to
inet_add_protocol, which is declared as const.  Thus the net_protocol
structures themselves can be const.

Done with the help of Coccinelle.

// <smpl>
@r disable optional_qualifier@
identifier i;
position p;
@@
static struct net_protocol i@p = { ... };

@ok1@
identifier r.i;
expression e1;
position p;
@@
 inet_add_protocol(&i@p,...)

@bad@
position p != {r.p,ok1.p};
identifier r.i;
struct net_protocol e;
@@
e@i@p

@depends on !bad disable optional_qualifier@
identifier r.i;
@@
static
+const
 struct net_protocol i = { ... };
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---
 net/ipv4/af_inet.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 5ce44fb..2e38624 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1594,7 +1594,7 @@ u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
 };
 #endif
 
-static struct net_protocol tcp_protocol = {
+static const struct net_protocol tcp_protocol = {
 	.early_demux	=	tcp_v4_early_demux,
 	.early_demux_handler =  tcp_v4_early_demux,
 	.handler	=	tcp_v4_rcv,
@@ -1604,7 +1604,7 @@ u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
 	.icmp_strict_tag_validation = 1,
 };
 
-static struct net_protocol udp_protocol = {
+static const struct net_protocol udp_protocol = {
 	.early_demux =	udp_v4_early_demux,
 	.early_demux_handler =	udp_v4_early_demux,
 	.handler =	udp_rcv,

[PATCH 2/2] l2tp: constify net_protocol structures

[Julia Lawall]

The net_protocol structure is only passed as the first argument to
inet_add_protocol or inet_del_protocol, both of which are declared
as const.  Thus the net_protocol structure itself can be const.

Done with the help of Coccinelle.

// <smpl>
@r disable optional_qualifier@
identifier i;
position p;
@@
static struct net_protocol i@p = { ... };

@ok1@
identifier r.i;
expression e1;
position p;
@@
 \(inet_add_protocol\|inet_del_protocol\)(&i@p,...)

@bad@
position p != {r.p,ok1.p};
identifier r.i;
struct net_protocol e;
@@
e@i@p

@depends on !bad disable optional_qualifier@
identifier r.i;
@@
static
+const
 struct net_protocol i = { ... };
// </smpl>

Also drop __read_mostly.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---
 net/l2tp/l2tp_ip.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c
index 4d322c1..c8e4d85 100644
--- a/net/l2tp/l2tp_ip.c
+++ b/net/l2tp/l2tp_ip.c
@@ -649,7 +649,7 @@ int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 	.ops		= &l2tp_ip_ops,
 };
 
-static struct net_protocol l2tp_ip_protocol __read_mostly = {
+static const struct net_protocol l2tp_ip_protocol = {
 	.handler	= l2tp_ip_recv,
 	.netns_ok	= 1,
 };