[PATCH net-next 0/2] ipv6: coding style - comparisons with NULL

[PATCH net-next 0/2] ipv6: coding style - comparisons with NULL

[Ian Morris]

The following patches address some coding style issues only. No functional changes and no changes detected by objdiff.

The IPV6 code uses multiple different styles when comparing with NULL (I.e. x == NULL and !x as well as x != NULL and x). Generally the latter form is preferred according to checkpatch and so this changes aligns the code to this style. 

Ian Morris (2):
  ipv6: coding style: comparison for equality with NULL
  ipv6: coding style: comparison for inequality with NULL

 net/ipv6/addrconf.c        | 88 +++++++++++++++++++++++-----------------------
 net/ipv6/addrconf_core.c   |  2 +-
 net/ipv6/af_inet6.c        | 14 ++++----
 net/ipv6/ah6.c             |  2 +-
 net/ipv6/anycast.c         | 10 +++---
 net/ipv6/datagram.c        |  6 ++--
 net/ipv6/esp6.c            |  2 +-
 net/ipv6/exthdrs_core.c    | 10 +++---
 net/ipv6/icmp.c            | 13 ++++---
 net/ipv6/ip6_fib.c         |  4 +--
 net/ipv6/ip6_flowlabel.c   | 22 ++++++------
 net/ipv6/ip6_gre.c         | 14 ++++----
 net/ipv6/ip6_input.c       |  2 +-
 net/ipv6/ip6_offload.c     |  2 +-
 net/ipv6/ip6_output.c      | 24 ++++++-------
 net/ipv6/ip6_tunnel.c      | 12 +++----
 net/ipv6/ip6_vti.c         | 12 +++----
 net/ipv6/ip6mr.c           | 50 +++++++++++++-------------
 net/ipv6/ipv6_sockglue.c   | 10 +++---
 net/ipv6/mcast.c           | 30 ++++++++--------
 net/ipv6/ndisc.c           | 20 +++++------
 net/ipv6/raw.c             | 14 ++++----
 net/ipv6/reassembly.c      |  8 ++---
 net/ipv6/route.c           |  2 +-
 net/ipv6/sit.c             | 22 ++++++------
 net/ipv6/sysctl_net_ipv6.c |  2 +-
 net/ipv6/tcp_ipv6.c        | 20 +++++------
 net/ipv6/udp.c             | 14 ++++----
 net/ipv6/xfrm6_policy.c    |  2 +-
 29 files changed, 216 insertions(+), 217 deletions(-)

-- 
1.9.1

[PATCH net-next 1/2] ipv6: coding style: comparison for equality with NULL

[Ian Morris]

The ipv6 code uses a mixture of coding styles. In some instances check for NULL
pointer is done as x == NULL and sometimes as !x. !x is preferred according to
checkpatch and this patch makes the code consistent by adopting the latter
form.

No changes detected by objdiff.

Signed-off-by: Ian Morris <ipm@chirality.org.uk>
---
 net/ipv6/addrconf.c        | 88 +++++++++++++++++++++++-----------------------
 net/ipv6/af_inet6.c        |  8 ++---
 net/ipv6/ah6.c             |  2 +-
 net/ipv6/anycast.c         | 10 +++---
 net/ipv6/datagram.c        |  6 ++--
 net/ipv6/esp6.c            |  2 +-
 net/ipv6/exthdrs_core.c    | 10 +++---
 net/ipv6/icmp.c            | 13 ++++---
 net/ipv6/ip6_flowlabel.c   | 16 ++++-----
 net/ipv6/ip6_gre.c         |  8 ++---
 net/ipv6/ip6_output.c      | 22 ++++++------
 net/ipv6/ip6_tunnel.c      |  8 ++---
 net/ipv6/ip6_vti.c         |  6 ++--
 net/ipv6/ip6mr.c           | 48 ++++++++++++-------------
 net/ipv6/ipv6_sockglue.c   | 10 +++---
 net/ipv6/mcast.c           | 14 ++++----
 net/ipv6/ndisc.c           | 20 +++++------
 net/ipv6/raw.c             | 10 +++---
 net/ipv6/reassembly.c      |  6 ++--
 net/ipv6/route.c           |  2 +-
 net/ipv6/sit.c             | 12 +++----
 net/ipv6/sysctl_net_ipv6.c |  2 +-
 net/ipv6/tcp_ipv6.c        | 12 +++----
 net/ipv6/udp.c             | 10 +++---
 net/ipv6/xfrm6_policy.c    |  2 +-
 25 files changed, 173 insertions(+), 174 deletions(-)

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 2660263..e86f743 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -334,7 +334,7 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev)
 		return ERR_PTR(-EINVAL);
 
 	ndev = kzalloc(sizeof(struct inet6_dev), GFP_KERNEL);
-	if (ndev == NULL)
+	if (!ndev)
 		return ERR_PTR(err);
 
 	rwlock_init(&ndev->lock);
@@ -346,7 +346,7 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev)
 	ndev->cnf.mtu6 = dev->mtu;
 	ndev->cnf.sysctl = NULL;
 	ndev->nd_parms = neigh_parms_alloc(dev, &nd_tbl);
-	if (ndev->nd_parms == NULL) {
+	if (!ndev->nd_parms) {
 		kfree(ndev);
 		return ERR_PTR(err);
 	}
@@ -481,7 +481,7 @@ static int inet6_netconf_fill_devconf(struct sk_buff *skb, int ifindex,
 
 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg),
 			flags);
-	if (nlh == NULL)
+	if (!nlh)
 		return -EMSGSIZE;
 
 	ncm = nlmsg_data(nlh);
@@ -519,7 +519,7 @@ void inet6_netconf_notify_devconf(struct net *net, int type, int ifindex,
 	int err = -ENOBUFS;
 
 	skb = nlmsg_new(inet6_netconf_msgsize_devconf(type), GFP_ATOMIC);
-	if (skb == NULL)
+	if (!skb)
 		goto errout;
 
 	err = inet6_netconf_fill_devconf(skb, ifindex, devconf, 0, 0,
@@ -574,10 +574,10 @@ static int inet6_netconf_get_devconf(struct sk_buff *in_skb,
 		break;
 	default:
 		dev = __dev_get_by_index(net, ifindex);
-		if (dev == NULL)
+		if (!dev)
 			goto errout;
 		in6_dev = __in6_dev_get(dev);
-		if (in6_dev == NULL)
+		if (!in6_dev)
 			goto errout;
 		devconf = &in6_dev->cnf;
 		break;
@@ -585,7 +585,7 @@ static int inet6_netconf_get_devconf(struct sk_buff *in_skb,
 
 	err = -ENOBUFS;
 	skb = nlmsg_new(inet6_netconf_msgsize_devconf(-1), GFP_ATOMIC);
-	if (skb == NULL)
+	if (!skb)
 		goto errout;
 
 	err = inet6_netconf_fill_devconf(skb, ifindex, devconf,
@@ -854,7 +854,7 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr,
 
 	ifa = kzalloc(sizeof(struct inet6_ifaddr), GFP_ATOMIC);
 
-	if (ifa == NULL) {
+	if (!ifa) {
 		ADBG("ipv6_add_addr: malloc failed\n");
 		err = -ENOBUFS;
 		goto out;
@@ -1558,7 +1558,7 @@ int ipv6_chk_addr_and_flags(struct net *net, const struct in6_addr *addr,
 			    : ifp->flags;
 		if (ipv6_addr_equal(&ifp->addr, addr) &&
 		    !(ifp_flags&banned_flags) &&
-		    (dev == NULL || ifp->idev->dev == dev ||
+		    (!dev || ifp->idev->dev == dev ||
 		     !(ifp->scope&(IFA_LINK|IFA_HOST) || strict))) {
 			rcu_read_unlock_bh();
 			return 1;
@@ -1580,7 +1580,7 @@ static bool ipv6_chk_same_addr(struct net *net, const struct in6_addr *addr,
 		if (!net_eq(dev_net(ifp->idev->dev), net))
 			continue;
 		if (ipv6_addr_equal(&ifp->addr, addr)) {
-			if (dev == NULL || ifp->idev->dev == dev)
+			if (!dev || ifp->idev->dev == dev)
 				return true;
 		}
 	}
@@ -1649,7 +1649,7 @@ struct inet6_ifaddr *ipv6_get_ifaddr(struct net *net, const struct in6_addr *add
 		if (!net_eq(dev_net(ifp->idev->dev), net))
 			continue;
 		if (ipv6_addr_equal(&ifp->addr, addr)) {
-			if (dev == NULL || ifp->idev->dev == dev ||
+			if (!dev || ifp->idev->dev == dev ||
 			    !(ifp->scope&(IFA_LINK|IFA_HOST) || strict)) {
 				result = ifp;
 				in6_ifa_hold(ifp);
@@ -2114,7 +2114,7 @@ static struct rt6_info *addrconf_get_prefix_route(const struct in6_addr *pfx,
 	struct fib6_table *table;
 
 	table = fib6_get_table(dev_net(dev), RT6_TABLE_PREFIX);
-	if (table == NULL)
+	if (!table)
 		return NULL;
 
 	read_lock_bh(&table->tb6_lock);
@@ -2278,7 +2278,7 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao)
 
 	in6_dev = in6_dev_get(dev);
 
-	if (in6_dev == NULL) {
+	if (!in6_dev) {
 		net_dbg_ratelimited("addrconf: device %s not configured\n",
 				    dev->name);
 		return;
@@ -2377,7 +2377,7 @@ ok:
 
 		ifp = ipv6_get_ifaddr(net, &addr, dev, 1);
 
-		if (ifp == NULL && valid_lft) {
+		if (!ifp && valid_lft) {
 			int max_addresses = in6_dev->cnf.max_addresses;
 
 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
@@ -2486,7 +2486,7 @@ int addrconf_set_dstaddr(struct net *net, void __user *arg)
 	dev = __dev_get_by_index(net, ireq.ifr6_ifindex);
 
 	err = -ENODEV;
-	if (dev == NULL)
+	if (!dev)
 		goto err_exit;
 
 #if IS_ENABLED(CONFIG_IPV6_SIT)
@@ -2658,7 +2658,7 @@ static int inet6_addr_del(struct net *net, int ifindex, u32 ifa_flags,
 		return -ENODEV;
 
 	idev = __in6_dev_get(dev);
-	if (idev == NULL)
+	if (!idev)
 		return -ENXIO;
 
 	read_lock_bh(&idev->lock);
@@ -2810,7 +2810,7 @@ static void init_loopback(struct net_device *dev)
 	ASSERT_RTNL();
 
 	idev = ipv6_find_idev(dev);
-	if (idev == NULL) {
+	if (!idev) {
 		pr_debug("%s: add_dev failed\n", __func__);
 		return;
 	}
@@ -3019,7 +3019,7 @@ static void addrconf_sit_config(struct net_device *dev)
 	 */
 
 	idev = ipv6_find_idev(dev);
-	if (idev == NULL) {
+	if (!idev) {
 		pr_debug("%s: add_dev failed\n", __func__);
 		return;
 	}
@@ -3044,7 +3044,7 @@ static void addrconf_gre_config(struct net_device *dev)
 	ASSERT_RTNL();
 
 	idev = ipv6_find_idev(dev);
-	if (idev == NULL) {
+	if (!idev) {
 		pr_debug("%s: add_dev failed\n", __func__);
 		return;
 	}
@@ -3241,7 +3241,7 @@ static int addrconf_ifdown(struct net_device *dev, int how)
 	neigh_ifdown(&nd_tbl, dev);
 
 	idev = __in6_dev_get(dev);
-	if (idev == NULL)
+	if (!idev)
 		return -ENODEV;
 
 	/*
@@ -3996,7 +3996,7 @@ inet6_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh)
 
 	ifm = nlmsg_data(nlh);
 	pfx = extract_addr(tb[IFA_ADDRESS], tb[IFA_LOCAL], &peer_pfx);
-	if (pfx == NULL)
+	if (!pfx)
 		return -EINVAL;
 
 	ifa_flags = tb[IFA_FLAGS] ? nla_get_u32(tb[IFA_FLAGS]) : ifm->ifa_flags;
@@ -4108,7 +4108,7 @@ inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh)
 
 	ifm = nlmsg_data(nlh);
 	pfx = extract_addr(tb[IFA_ADDRESS], tb[IFA_LOCAL], &peer_pfx);
-	if (pfx == NULL)
+	if (!pfx)
 		return -EINVAL;
 
 	if (tb[IFA_CACHEINFO]) {
@@ -4123,7 +4123,7 @@ inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh)
 	}
 
 	dev =  __dev_get_by_index(net, ifm->ifa_index);
-	if (dev == NULL)
+	if (!dev)
 		return -ENODEV;
 
 	ifa_flags = tb[IFA_FLAGS] ? nla_get_u32(tb[IFA_FLAGS]) : ifm->ifa_flags;
@@ -4133,7 +4133,7 @@ inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh)
 		     IFA_F_NOPREFIXROUTE | IFA_F_MCAUTOJOIN;
 
 	ifa = ipv6_get_ifaddr(net, pfx, dev, 1);
-	if (ifa == NULL) {
+	if (!ifa) {
 		/*
 		 * It would be best to check for !NLM_F_CREATE here but
 		 * userspace already relies on not having to provide this.
@@ -4208,7 +4208,7 @@ static int inet6_fill_ifaddr(struct sk_buff *skb, struct inet6_ifaddr *ifa,
 	u32 preferred, valid;
 
 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct ifaddrmsg), flags);
-	if (nlh == NULL)
+	if (!nlh)
 		return -EMSGSIZE;
 
 	put_ifaddrmsg(nlh, ifa->prefix_len, ifa->flags, rt_scope(ifa->scope),
@@ -4269,7 +4269,7 @@ static int inet6_fill_ifmcaddr(struct sk_buff *skb, struct ifmcaddr6 *ifmca,
 		scope = RT_SCOPE_SITE;
 
 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct ifaddrmsg), flags);
-	if (nlh == NULL)
+	if (!nlh)
 		return -EMSGSIZE;
 
 	put_ifaddrmsg(nlh, 128, IFA_F_PERMANENT, scope, ifindex);
@@ -4295,7 +4295,7 @@ static int inet6_fill_ifacaddr(struct sk_buff *skb, struct ifacaddr6 *ifaca,
 		scope = RT_SCOPE_SITE;
 
 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct ifaddrmsg), flags);
-	if (nlh == NULL)
+	if (!nlh)
 		return -EMSGSIZE;
 
 	put_ifaddrmsg(nlh, 128, IFA_F_PERMANENT, scope, ifindex);
@@ -4468,7 +4468,7 @@ static int inet6_rtm_getaddr(struct sk_buff *in_skb, struct nlmsghdr *nlh)
 		goto errout;
 
 	addr = extract_addr(tb[IFA_ADDRESS], tb[IFA_LOCAL], &peer);
-	if (addr == NULL) {
+	if (!addr) {
 		err = -EINVAL;
 		goto errout;
 	}
@@ -4511,7 +4511,7 @@ static void inet6_ifa_notify(int event, struct inet6_ifaddr *ifa)
 	int err = -ENOBUFS;
 
 	skb = nlmsg_new(inet6_ifaddr_msgsize(), GFP_ATOMIC);
-	if (skb == NULL)
+	if (!skb)
 		goto errout;
 
 	err = inet6_fill_ifaddr(skb, ifa, 0, 0, event, 0);
@@ -4664,24 +4664,24 @@ static int inet6_fill_ifla6_attrs(struct sk_buff *skb, struct inet6_dev *idev)
 	if (nla_put(skb, IFLA_INET6_CACHEINFO, sizeof(ci), &ci))
 		goto nla_put_failure;
 	nla = nla_reserve(skb, IFLA_INET6_CONF, DEVCONF_MAX * sizeof(s32));
-	if (nla == NULL)
+	if (!nla)
 		goto nla_put_failure;
 	ipv6_store_devconf(&idev->cnf, nla_data(nla), nla_len(nla));
 
 	/* XXX - MC not implemented */
 
 	nla = nla_reserve(skb, IFLA_INET6_STATS, IPSTATS_MIB_MAX * sizeof(u64));
-	if (nla == NULL)
+	if (!nla)
 		goto nla_put_failure;
 	snmp6_fill_stats(nla_data(nla), idev, IFLA_INET6_STATS, nla_len(nla));
 
 	nla = nla_reserve(skb, IFLA_INET6_ICMP6STATS, ICMP6_MIB_MAX * sizeof(u64));
-	if (nla == NULL)
+	if (!nla)
 		goto nla_put_failure;
 	snmp6_fill_stats(nla_data(nla), idev, IFLA_INET6_ICMP6STATS, nla_len(nla));
 
 	nla = nla_reserve(skb, IFLA_INET6_TOKEN, sizeof(struct in6_addr));
-	if (nla == NULL)
+	if (!nla)
 		goto nla_put_failure;
 
 	if (nla_put_u8(skb, IFLA_INET6_ADDR_GEN_MODE, idev->addr_gen_mode))
@@ -4727,7 +4727,7 @@ static int inet6_set_iftoken(struct inet6_dev *idev, struct in6_addr *token)
 
 	ASSERT_RTNL();
 
-	if (token == NULL)
+	if (!token)
 		return -EINVAL;
 	if (ipv6_addr_any(token))
 		return -EINVAL;
@@ -4843,7 +4843,7 @@ static int inet6_fill_ifinfo(struct sk_buff *skb, struct inet6_dev *idev,
 	void *protoinfo;
 
 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*hdr), flags);
-	if (nlh == NULL)
+	if (!nlh)
 		return -EMSGSIZE;
 
 	hdr = nlmsg_data(nlh);
@@ -4862,7 +4862,7 @@ static int inet6_fill_ifinfo(struct sk_buff *skb, struct inet6_dev *idev,
 	     nla_put_u32(skb, IFLA_LINK, dev->iflink)))
 		goto nla_put_failure;
 	protoinfo = nla_nest_start(skb, IFLA_PROTINFO);
-	if (protoinfo == NULL)
+	if (!protoinfo)
 		goto nla_put_failure;
 
 	if (inet6_fill_ifla6_attrs(skb, idev) < 0)
@@ -4923,7 +4923,7 @@ void inet6_ifinfo_notify(int event, struct inet6_dev *idev)
 	int err = -ENOBUFS;
 
 	skb = nlmsg_new(inet6_if_nlmsg_size(), GFP_ATOMIC);
-	if (skb == NULL)
+	if (!skb)
 		goto errout;
 
 	err = inet6_fill_ifinfo(skb, idev, 0, 0, event, 0);
@@ -4956,7 +4956,7 @@ static int inet6_fill_prefix(struct sk_buff *skb, struct inet6_dev *idev,
 	struct prefix_cacheinfo	ci;
 
 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*pmsg), flags);
-	if (nlh == NULL)
+	if (!nlh)
 		return -EMSGSIZE;
 
 	pmsg = nlmsg_data(nlh);
@@ -4995,7 +4995,7 @@ static void inet6_prefix_notify(int event, struct inet6_dev *idev,
 	int err = -ENOBUFS;
 
 	skb = nlmsg_new(inet6_prefix_nlmsg_size(), GFP_ATOMIC);
-	if (skb == NULL)
+	if (!skb)
 		goto errout;
 
 	err = inet6_fill_prefix(skb, idev, pinfo, 0, 0, event, 0);
@@ -5596,7 +5596,7 @@ static int __addrconf_sysctl_register(struct net *net, char *dev_name,
 	char path[sizeof("net/ipv6/conf/") + IFNAMSIZ];
 
 	t = kmemdup(&addrconf_sysctl, sizeof(*t), GFP_KERNEL);
-	if (t == NULL)
+	if (!t)
 		goto out;
 
 	for (i = 0; t->addrconf_vars[i].data; i++) {
@@ -5608,7 +5608,7 @@ static int __addrconf_sysctl_register(struct net *net, char *dev_name,
 	snprintf(path, sizeof(path), "net/ipv6/conf/%s", dev_name);
 
 	t->sysctl_header = register_net_sysctl(net, path, t->addrconf_vars);
-	if (t->sysctl_header == NULL)
+	if (!t->sysctl_header)
 		goto free;
 
 	p->sysctl = t;
@@ -5624,7 +5624,7 @@ static void __addrconf_sysctl_unregister(struct ipv6_devconf *p)
 {
 	struct addrconf_sysctl_table *t;
 
-	if (p->sysctl == NULL)
+	if (!p->sysctl)
 		return;
 
 	t = p->sysctl;
@@ -5667,11 +5667,11 @@ static int __net_init addrconf_init_net(struct net *net)
 	struct ipv6_devconf *all, *dflt;
 
 	all = kmemdup(&ipv6_devconf, sizeof(ipv6_devconf), GFP_KERNEL);
-	if (all == NULL)
+	if (!all)
 		goto err_alloc_all;
 
 	dflt = kmemdup(&ipv6_devconf_dflt, sizeof(ipv6_devconf_dflt), GFP_KERNEL);
-	if (dflt == NULL)
+	if (!dflt)
 		goto err_alloc_dflt;
 
 	/* these will be inherited by all namespaces */
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index d8dcc52..0e48897 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -164,11 +164,11 @@ lookup_protocol:
 	answer_flags = answer->flags;
 	rcu_read_unlock();
 
-	WARN_ON(answer_prot->slab == NULL);
+	WARN_ON(!answer_prot->slab);
 
 	err = -ENOBUFS;
 	sk = sk_alloc(net, PF_INET6, GFP_KERNEL, answer_prot);
-	if (sk == NULL)
+	if (!sk)
 		goto out;
 
 	sock_init_data(sock, sk);
@@ -391,7 +391,7 @@ int inet6_release(struct socket *sock)
 {
 	struct sock *sk = sock->sk;
 
-	if (sk == NULL)
+	if (!sk)
 		return -EINVAL;
 
 	/* Free mc lists */
@@ -640,7 +640,7 @@ int inet6_sk_rebuild_header(struct sock *sk)
 
 	dst = __sk_dst_check(sk, np->dst_cookie);
 
-	if (dst == NULL) {
+	if (!dst) {
 		struct inet_sock *inet = inet_sk(sk);
 		struct in6_addr *final_p, final;
 		struct flowi6 fl6;
diff --git a/net/ipv6/ah6.c b/net/ipv6/ah6.c
index a6727ad..ed7d4e3f 100644
--- a/net/ipv6/ah6.c
+++ b/net/ipv6/ah6.c
@@ -681,7 +681,7 @@ static int ah6_init_state(struct xfrm_state *x)
 		goto error;
 
 	ahp = kzalloc(sizeof(*ahp), GFP_KERNEL);
-	if (ahp == NULL)
+	if (!ahp)
 		return -ENOMEM;
 
 	ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0);
diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
index 9e6b0ee..514ac25 100644
--- a/net/ipv6/anycast.c
+++ b/net/ipv6/anycast.c
@@ -70,7 +70,7 @@ int ipv6_sock_ac_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
 		return -EINVAL;
 
 	pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL);
-	if (pac == NULL)
+	if (!pac)
 		return -ENOMEM;
 	pac->acl_next = NULL;
 	pac->acl_addr = *addr;
@@ -93,7 +93,7 @@ int ipv6_sock_ac_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
 	} else
 		dev = __dev_get_by_index(net, ifindex);
 
-	if (dev == NULL) {
+	if (!dev) {
 		err = -ENODEV;
 		goto error;
 	}
@@ -222,7 +222,7 @@ static struct ifacaddr6 *aca_alloc(struct rt6_info *rt,
 	struct ifacaddr6 *aca;
 
 	aca = kzalloc(sizeof(*aca), GFP_ATOMIC);
-	if (aca == NULL)
+	if (!aca)
 		return NULL;
 
 	aca->aca_addr = *addr;
@@ -268,7 +268,7 @@ int __ipv6_dev_ac_inc(struct inet6_dev *idev, const struct in6_addr *addr)
 		goto out;
 	}
 	aca = aca_alloc(rt, addr);
-	if (aca == NULL) {
+	if (!aca) {
 		ip6_rt_put(rt);
 		err = -ENOMEM;
 		goto out;
@@ -337,7 +337,7 @@ static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr)
 {
 	struct inet6_dev *idev = __in6_dev_get(dev);
 
-	if (idev == NULL)
+	if (!idev)
 		return -ENODEV;
 	return __ipv6_dev_ac_dec(idev, addr);
 }
diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
index ace8dac..762a58c 100644
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -71,7 +71,7 @@ int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 		fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
 		if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
 			flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
-			if (flowlabel == NULL)
+			if (!flowlabel)
 				return -EINVAL;
 		}
 	}
@@ -373,7 +373,7 @@ int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 
 	err = -EAGAIN;
 	skb = sock_dequeue_err_skb(sk);
-	if (skb == NULL)
+	if (!skb)
 		goto out;
 
 	copied = skb->len;
@@ -463,7 +463,7 @@ int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 
 	err = -EAGAIN;
 	skb = xchg(&np->rxpmtu, NULL);
-	if (skb == NULL)
+	if (!skb)
 		goto out;
 
 	copied = skb->len;
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index e48f2c7..31f1b5d 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -495,7 +495,7 @@ static int esp_init_authenc(struct xfrm_state *x)
 	int err;
 
 	err = -EINVAL;
-	if (x->ealg == NULL)
+	if (!x->ealg)
 		goto error;
 
 	err = -ENAMETOOLONG;
diff --git a/net/ipv6/exthdrs_core.c b/net/ipv6/exthdrs_core.c
index 8af3eb5..5c5d23e 100644
--- a/net/ipv6/exthdrs_core.c
+++ b/net/ipv6/exthdrs_core.c
@@ -82,7 +82,7 @@ int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp,
 		if (nexthdr == NEXTHDR_NONE)
 			return -1;
 		hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr);
-		if (hp == NULL)
+		if (!hp)
 			return -1;
 		if (nexthdr == NEXTHDR_FRAGMENT) {
 			__be16 _frag_off, *fp;
@@ -91,7 +91,7 @@ int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp,
 							       frag_off),
 						sizeof(_frag_off),
 						&_frag_off);
-			if (fp == NULL)
+			if (!fp)
 				return -1;
 
 			*frag_offp = *fp;
@@ -218,7 +218,7 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 		}
 
 		hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr);
-		if (hp == NULL)
+		if (!hp)
 			return -EBADMSG;
 
 		if (nexthdr == NEXTHDR_ROUTING) {
@@ -226,7 +226,7 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 
 			rh = skb_header_pointer(skb, start, sizeof(_rh),
 						&_rh);
-			if (rh == NULL)
+			if (!rh)
 				return -EBADMSG;
 
 			if (flags && (*flags & IP6_FH_F_SKIP_RH) &&
@@ -245,7 +245,7 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 							       frag_off),
 						sizeof(_frag_off),
 						&_frag_off);
-			if (fp == NULL)
+			if (!fp)
 				return -EBADMSG;
 
 			_frag_off = ntohs(*fp) & ~0x7;
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index a5e9519..2c2b5d5 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -160,8 +160,7 @@ static bool is_ineligible(const struct sk_buff *skb)
 		tp = skb_header_pointer(skb,
 			ptr+offsetof(struct icmp6hdr, icmp6_type),
 			sizeof(_type), &_type);
-		if (tp == NULL ||
-		    !(*tp & ICMPV6_INFOMSG_MASK))
+		if (!tp || !(*tp & ICMPV6_INFOMSG_MASK))
 			return true;
 	}
 	return false;
@@ -231,7 +230,7 @@ static bool opt_unrec(struct sk_buff *skb, __u32 offset)
 
 	offset += skb_network_offset(skb);
 	op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
-	if (op == NULL)
+	if (!op)
 		return true;
 	return (*op & 0xC0) == 0x80;
 }
@@ -244,7 +243,7 @@ int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
 	int err = 0;
 
 	skb = skb_peek(&sk->sk_write_queue);
-	if (skb == NULL)
+	if (!skb)
 		goto out;
 
 	icmp6h = icmp6_hdr(skb);
@@ -479,7 +478,7 @@ static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
 	security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 
 	sk = icmpv6_xmit_lock(net);
-	if (sk == NULL)
+	if (!sk)
 		return;
 	sk->sk_mark = mark;
 	np = inet6_sk(sk);
@@ -582,7 +581,7 @@ static void icmpv6_echo_reply(struct sk_buff *skb)
 	security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 
 	sk = icmpv6_xmit_lock(net);
-	if (sk == NULL)
+	if (!sk)
 		return;
 	sk->sk_mark = mark;
 	np = inet6_sk(sk);
@@ -839,7 +838,7 @@ static int __net_init icmpv6_sk_init(struct net *net)
 
 	net->ipv6.icmp_sk =
 		kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
-	if (net->ipv6.icmp_sk == NULL)
+	if (!net->ipv6.icmp_sk)
 		return -ENOMEM;
 
 	for_each_possible_cpu(i) {
diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index 4573038..3f54ac5 100644
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -205,7 +205,7 @@ static struct ip6_flowlabel *fl_intern(struct net *net,
 			fl->label = htonl(prandom_u32())&IPV6_FLOWLABEL_MASK;
 			if (fl->label) {
 				lfl = __fl_lookup(net, fl->label);
-				if (lfl == NULL)
+				if (!lfl)
 					break;
 			}
 		}
@@ -297,7 +297,7 @@ struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
 {
 	struct ipv6_txoptions *fl_opt = fl->opt;
 
-	if (fopt == NULL || fopt->opt_flen == 0)
+	if (!fopt || fopt->opt_flen == 0)
 		return fl_opt;
 
 	if (fl_opt != NULL) {
@@ -366,7 +366,7 @@ fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
 
 	err = -ENOMEM;
 	fl = kzalloc(sizeof(*fl), GFP_KERNEL);
-	if (fl == NULL)
+	if (!fl)
 		goto done;
 
 	if (olen > 0) {
@@ -376,7 +376,7 @@ fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
 
 		err = -ENOMEM;
 		fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
-		if (fl->opt == NULL)
+		if (!fl->opt)
 			goto done;
 
 		memset(fl->opt, 0, sizeof(*fl->opt));
@@ -596,7 +596,7 @@ int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 			return -EINVAL;
 
 		fl = fl_create(net, sk, &freq, optval, optlen, &err);
-		if (fl == NULL)
+		if (!fl)
 			return err;
 		sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
 
@@ -616,7 +616,7 @@ int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 			}
 			rcu_read_unlock_bh();
 
-			if (fl1 == NULL)
+			if (!fl1)
 				fl1 = fl_lookup(net, freq.flr_label);
 			if (fl1) {
 recheck:
@@ -633,7 +633,7 @@ recheck:
 					goto release;
 
 				err = -ENOMEM;
-				if (sfl1 == NULL)
+				if (!sfl1)
 					goto release;
 				if (fl->linger > fl1->linger)
 					fl1->linger = fl->linger;
@@ -653,7 +653,7 @@ release:
 			goto done;
 
 		err = -ENOMEM;
-		if (sfl1 == NULL)
+		if (!sfl1)
 			goto done;
 
 		err = mem_check(sk);
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index bc28b7d..aa9ea6e 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -395,7 +395,7 @@ static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 				flags & GRE_KEY ?
 				*(((__be32 *)p) + (grehlen / 4) - 1) : 0,
 				p[1]);
-	if (t == NULL)
+	if (!t)
 		return;
 
 	switch (type) {
@@ -980,7 +980,7 @@ static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
 						 &p->raddr, &p->laddr,
 						 p->link, strict);
 
-		if (rt == NULL)
+		if (!rt)
 			return;
 
 		if (rt->dst.dev) {
@@ -1073,7 +1073,7 @@ static int ip6gre_tunnel_ioctl(struct net_device *dev,
 			}
 			ip6gre_tnl_parm_from_user(&p1, &p);
 			t = ip6gre_tunnel_locate(net, &p1, 0);
-			if (t == NULL)
+			if (!t)
 				t = netdev_priv(dev);
 		}
 		memset(&p, 0, sizeof(p));
@@ -1144,7 +1144,7 @@ static int ip6gre_tunnel_ioctl(struct net_device *dev,
 			err = -ENOENT;
 			ip6gre_tnl_parm_from_user(&p1, &p);
 			t = ip6gre_tunnel_locate(net, &p1, 0);
-			if (t == NULL)
+			if (!t)
 				goto done;
 			err = -EPERM;
 			if (t == netdev_priv(ign->fb_tunnel_dev))
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index b06ad00..8b6d402 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -177,7 +177,7 @@ int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
 
 		if (skb_headroom(skb) < head_room) {
 			struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
-			if (skb2 == NULL) {
+			if (!skb2) {
 				IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
 					      IPSTATS_MIB_OUTDISCARDS);
 				kfree_skb(skb);
@@ -823,7 +823,7 @@ static inline int ip6_rt_check(const struct rt6key *rt_key,
 			       const struct in6_addr *addr_cache)
 {
 	return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
-		(addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache));
+		(!addr_cache || !ipv6_addr_equal(fl_addr, addr_cache));
 }
 
 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
@@ -882,7 +882,7 @@ static int ip6_dst_lookup_tail(struct sock *sk,
 #endif
 	int err;
 
-	if (*dst == NULL)
+	if (!*dst)
 		*dst = ip6_route_output(net, sk, fl6);
 
 	err = (*dst)->error;
@@ -1045,11 +1045,11 @@ static inline int ip6_ufo_append_data(struct sock *sk,
 	 * udp datagram
 	 */
 	skb = skb_peek_tail(queue);
-	if (skb == NULL) {
+	if (!skb) {
 		skb = sock_alloc_send_skb(sk,
 			hh_len + fragheaderlen + transhdrlen + 20,
 			(flags & MSG_DONTWAIT), &err);
-		if (skb == NULL)
+		if (!skb)
 			return err;
 
 		/* reserve space for Hardware header */
@@ -1107,7 +1107,7 @@ static void ip6_append_data_mtu(unsigned int *mtu,
 				unsigned int orig_mtu)
 {
 	if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
-		if (skb == NULL) {
+		if (!skb) {
 			/* first fragment, reserve header_len */
 			*mtu = orig_mtu - rt->dst.header_len;
 
@@ -1139,7 +1139,7 @@ static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
 			return -EINVAL;
 
 		v6_cork->opt = kzalloc(opt->tot_len, sk->sk_allocation);
-		if (unlikely(v6_cork->opt == NULL))
+		if (unlikely(!v6_cork->opt))
 			return -ENOBUFS;
 
 		v6_cork->opt->tot_len = opt->tot_len;
@@ -1331,7 +1331,7 @@ alloc_new_skb:
 			else
 				fraggap = 0;
 			/* update mtu and maxfraglen if necessary */
-			if (skb == NULL || skb_prev == NULL)
+			if (!skb || !skb_prev)
 				ip6_append_data_mtu(&mtu, &maxfraglen,
 						    fragheaderlen, skb, rt,
 						    orig_mtu);
@@ -1383,10 +1383,10 @@ alloc_new_skb:
 					skb = sock_wmalloc(sk,
 							   alloclen + hh_len, 1,
 							   sk->sk_allocation);
-				if (unlikely(skb == NULL))
+				if (unlikely(!skb))
 					err = -ENOBUFS;
 			}
-			if (skb == NULL)
+			if (!skb)
 				goto error;
 			/*
 			 *	Fill in the control structures
@@ -1578,7 +1578,7 @@ struct sk_buff *__ip6_make_skb(struct sock *sk,
 	unsigned char proto = fl6->flowi6_proto;
 
 	skb = __skb_dequeue(queue);
-	if (skb == NULL)
+	if (!skb)
 		goto out;
 	tail_skb = &(skb_shinfo(skb)->frag_list);
 
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 41f84f7..6740206 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -131,7 +131,7 @@ struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t)
 	struct dst_entry *dst = t->dst_cache;
 
 	if (dst && dst->obsolete &&
-	    dst->ops->check(dst, t->dst_cookie) == NULL) {
+	    !dst->ops->check(dst, t->dst_cookie)) {
 		t->dst_cache = NULL;
 		dst_release(dst);
 		return NULL;
@@ -325,7 +325,7 @@ static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
 
 	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 			   ip6_tnl_dev_setup);
-	if (dev == NULL)
+	if (!dev)
 		goto failed;
 
 	dev_net_set(dev, net);
@@ -496,7 +496,7 @@ ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
 
 	rcu_read_lock();
 	t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, &ipv6h->saddr);
-	if (t == NULL)
+	if (!t)
 		goto out;
 
 	tproto = ACCESS_ONCE(t->parms.proto);
@@ -1274,7 +1274,7 @@ static void ip6_tnl_link_config(struct ip6_tnl *t)
 						 &p->raddr, &p->laddr,
 						 p->link, strict);
 
-		if (rt == NULL)
+		if (!rt)
 			return;
 
 		if (rt->dst.dev) {
diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index 5fb9e21..a045d54 100644
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -218,7 +218,7 @@ static struct ip6_tnl *vti6_tnl_create(struct net *net, struct __ip6_tnl_parm *p
 		sprintf(name, "ip6_vti%%d");
 
 	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, vti6_dev_setup);
-	if (dev == NULL)
+	if (!dev)
 		goto failed;
 
 	dev_net_set(dev, net);
@@ -716,7 +716,7 @@ vti6_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 		} else {
 			memset(&p, 0, sizeof(p));
 		}
-		if (t == NULL)
+		if (!t)
 			t = netdev_priv(dev);
 		vti6_parm_to_user(&p, &t->parms);
 		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
@@ -767,7 +767,7 @@ vti6_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 			err = -ENOENT;
 			vti6_parm_from_user(&p1, &p);
 			t = vti6_locate(net, &p1, 0);
-			if (t == NULL)
+			if (!t)
 				break;
 			err = -EPERM;
 			if (t->dev == ip6n->fb_tnl_dev)
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 4b9315a..ebb0514 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -173,7 +173,7 @@ static int ip6mr_rule_action(struct fib_rule *rule, struct flowi *flp,
 	}
 
 	mrt = ip6mr_get_table(rule->fr_net, rule->table);
-	if (mrt == NULL)
+	if (!mrt)
 		return -EAGAIN;
 	res->mrt = mrt;
 	return 0;
@@ -237,7 +237,7 @@ static int __net_init ip6mr_rules_init(struct net *net)
 	INIT_LIST_HEAD(&net->ipv6.mr6_tables);
 
 	mrt = ip6mr_new_table(net, RT6_TABLE_DFLT);
-	if (mrt == NULL) {
+	if (!mrt) {
 		err = -ENOMEM;
 		goto err1;
 	}
@@ -309,7 +309,7 @@ static struct mr6_table *ip6mr_new_table(struct net *net, u32 id)
 		return mrt;
 
 	mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
-	if (mrt == NULL)
+	if (!mrt)
 		return NULL;
 	mrt->id = id;
 	write_pnet(&mrt->net, net);
@@ -408,7 +408,7 @@ static void *ip6mr_vif_seq_start(struct seq_file *seq, loff_t *pos)
 	struct mr6_table *mrt;
 
 	mrt = ip6mr_get_table(net, RT6_TABLE_DFLT);
-	if (mrt == NULL)
+	if (!mrt)
 		return ERR_PTR(-ENOENT);
 
 	iter->mrt = mrt;
@@ -492,7 +492,7 @@ static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
 	struct mr6_table *mrt;
 
 	mrt = ip6mr_get_table(net, RT6_TABLE_DFLT);
-	if (mrt == NULL)
+	if (!mrt)
 		return ERR_PTR(-ENOENT);
 
 	it->mrt = mrt;
@@ -665,7 +665,7 @@ static int pim6_rcv(struct sk_buff *skb)
 		dev_hold(reg_dev);
 	read_unlock(&mrt_lock);
 
-	if (reg_dev == NULL)
+	if (!reg_dev)
 		goto drop;
 
 	skb->mac_header = skb->network_header;
@@ -743,7 +743,7 @@ static struct net_device *ip6mr_reg_vif(struct net *net, struct mr6_table *mrt)
 		sprintf(name, "pim6reg%u", mrt->id);
 
 	dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup);
-	if (dev == NULL)
+	if (!dev)
 		return NULL;
 
 	dev_net_set(dev, net);
@@ -1072,7 +1072,7 @@ skip:
 static struct mfc6_cache *ip6mr_cache_alloc(void)
 {
 	struct mfc6_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
-	if (c == NULL)
+	if (!c)
 		return NULL;
 	c->mfc_un.res.minvif = MAXMIFS;
 	return c;
@@ -1081,7 +1081,7 @@ static struct mfc6_cache *ip6mr_cache_alloc(void)
 static struct mfc6_cache *ip6mr_cache_alloc_unres(void)
 {
 	struct mfc6_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
-	if (c == NULL)
+	if (!c)
 		return NULL;
 	skb_queue_head_init(&c->mfc_un.unres.unresolved);
 	c->mfc_un.unres.expires = jiffies + 10 * HZ;
@@ -1198,7 +1198,7 @@ static int ip6mr_cache_report(struct mr6_table *mrt, struct sk_buff *pkt,
 	skb->ip_summed = CHECKSUM_UNNECESSARY;
 	}
 
-	if (mrt->mroute6_sk == NULL) {
+	if (!mrt->mroute6_sk) {
 		kfree_skb(skb);
 		return -EINVAL;
 	}
@@ -1493,7 +1493,7 @@ static int ip6mr_mfc_add(struct net *net, struct mr6_table *mrt,
 		return -EINVAL;
 
 	c = ip6mr_cache_alloc();
-	if (c == NULL)
+	if (!c)
 		return -ENOMEM;
 
 	c->mf6c_origin = mfc->mf6cc_origin.sin6_addr;
@@ -1663,7 +1663,7 @@ int ip6_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, uns
 	struct mr6_table *mrt;
 
 	mrt = ip6mr_get_table(net, raw6_sk(sk)->ip6mr_table ? : RT6_TABLE_DFLT);
-	if (mrt == NULL)
+	if (!mrt)
 		return -ENOENT;
 
 	if (optname != MRT6_INIT) {
@@ -1812,7 +1812,7 @@ int ip6_mroute_getsockopt(struct sock *sk, int optname, char __user *optval,
 	struct mr6_table *mrt;
 
 	mrt = ip6mr_get_table(net, raw6_sk(sk)->ip6mr_table ? : RT6_TABLE_DFLT);
-	if (mrt == NULL)
+	if (!mrt)
 		return -ENOENT;
 
 	switch (optname) {
@@ -1859,7 +1859,7 @@ int ip6mr_ioctl(struct sock *sk, int cmd, void __user *arg)
 	struct mr6_table *mrt;
 
 	mrt = ip6mr_get_table(net, raw6_sk(sk)->ip6mr_table ? : RT6_TABLE_DFLT);
-	if (mrt == NULL)
+	if (!mrt)
 		return -ENOENT;
 
 	switch (cmd) {
@@ -1933,7 +1933,7 @@ int ip6mr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
 	struct mr6_table *mrt;
 
 	mrt = ip6mr_get_table(net, raw6_sk(sk)->ip6mr_table ? : RT6_TABLE_DFLT);
-	if (mrt == NULL)
+	if (!mrt)
 		return -ENOENT;
 
 	switch (cmd) {
@@ -2003,7 +2003,7 @@ static int ip6mr_forward2(struct net *net, struct mr6_table *mrt,
 	struct dst_entry *dst;
 	struct flowi6 fl6;
 
-	if (vif->dev == NULL)
+	if (!vif->dev)
 		goto out_free;
 
 #ifdef CONFIG_IPV6_PIMSM_V2
@@ -2192,7 +2192,7 @@ int ip6_mr_input(struct sk_buff *skb)
 	read_lock(&mrt_lock);
 	cache = ip6mr_cache_find(mrt,
 				 &ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr);
-	if (cache == NULL) {
+	if (!cache) {
 		int vif = ip6mr_find_vif(mrt, skb->dev);
 
 		if (vif >= 0)
@@ -2204,7 +2204,7 @@ int ip6_mr_input(struct sk_buff *skb)
 	/*
 	 *	No usable cache entry
 	 */
-	if (cache == NULL) {
+	if (!cache) {
 		int vif;
 
 		vif = ip6mr_find_vif(mrt, skb->dev);
@@ -2243,13 +2243,13 @@ static int __ip6mr_fill_mroute(struct mr6_table *mrt, struct sk_buff *skb,
 	    nla_put_u32(skb, RTA_IIF, mrt->vif6_table[c->mf6c_parent].dev->ifindex) < 0)
 		return -EMSGSIZE;
 	mp_attr = nla_nest_start(skb, RTA_MULTIPATH);
-	if (mp_attr == NULL)
+	if (!mp_attr)
 		return -EMSGSIZE;
 
 	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
 		if (MIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
 			nhp = nla_reserve_nohdr(skb, sizeof(*nhp));
-			if (nhp == NULL) {
+			if (!nhp) {
 				nla_nest_cancel(skb, mp_attr);
 				return -EMSGSIZE;
 			}
@@ -2282,7 +2282,7 @@ int ip6mr_get_route(struct net *net,
 	struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
 
 	mrt = ip6mr_get_table(net, RT6_TABLE_DFLT);
-	if (mrt == NULL)
+	if (!mrt)
 		return -ENOENT;
 
 	read_lock(&mrt_lock);
@@ -2307,7 +2307,7 @@ int ip6mr_get_route(struct net *net,
 		}
 
 		dev = skb->dev;
-		if (dev == NULL || (vif = ip6mr_find_vif(mrt, dev)) < 0) {
+		if (!dev || (vif = ip6mr_find_vif(mrt, dev)) < 0) {
 			read_unlock(&mrt_lock);
 			return -ENODEV;
 		}
@@ -2359,7 +2359,7 @@ static int ip6mr_fill_mroute(struct mr6_table *mrt, struct sk_buff *skb,
 	int err;
 
 	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
-	if (nlh == NULL)
+	if (!nlh)
 		return -EMSGSIZE;
 
 	rtm = nlmsg_data(nlh);
@@ -2424,7 +2424,7 @@ static void mr6_netlink_event(struct mr6_table *mrt, struct mfc6_cache *mfc,
 
 	skb = nlmsg_new(mr6_msgsize(mfc->mf6c_parent >= MAXMIFS, mrt->maxvif),
 			GFP_ATOMIC);
-	if (skb == NULL)
+	if (!skb)
 		goto errout;
 
 	err = ip6mr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index 9b2cb14..63e6956 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -85,7 +85,7 @@ int ip6_ra_control(struct sock *sk, int sel)
 			return 0;
 		}
 	}
-	if (new_ra == NULL) {
+	if (!new_ra) {
 		write_unlock_bh(&ip6_ra_lock);
 		return -ENOBUFS;
 	}
@@ -145,7 +145,7 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 	int retv = -ENOPROTOOPT;
 	bool needs_rtnl = setsockopt_needs_rtnl(optname);
 
-	if (optval == NULL)
+	if (!optval)
 		val = 0;
 	else {
 		if (optlen >= sizeof(int)) {
@@ -392,7 +392,7 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 		 */
 		if (optlen == 0)
 			optval = NULL;
-		else if (optval == NULL)
+		else if (!optval)
 			goto e_inval;
 		else if (optlen < sizeof(struct ipv6_opt_hdr) ||
 			 optlen & 0x7 || optlen > 8 * 255)
@@ -443,7 +443,7 @@ sticky_done:
 
 		if (optlen == 0)
 			goto e_inval;
-		else if (optlen < sizeof(struct in6_pktinfo) || optval == NULL)
+		else if (optlen < sizeof(struct in6_pktinfo) || !optval)
 			goto e_inval;
 
 		if (copy_from_user(&pkt, optval, sizeof(struct in6_pktinfo))) {
@@ -482,7 +482,7 @@ sticky_done:
 
 		opt = sock_kmalloc(sk, sizeof(*opt) + optlen, GFP_KERNEL);
 		retv = -ENOBUFS;
-		if (opt == NULL)
+		if (!opt)
 			break;
 
 		memset(opt, 0, sizeof(*opt));
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index cbb66fd..3017c4a 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -157,7 +157,7 @@ int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
 
 	mc_lst = sock_kmalloc(sk, sizeof(struct ipv6_mc_socklist), GFP_KERNEL);
 
-	if (mc_lst == NULL)
+	if (!mc_lst)
 		return -ENOMEM;
 
 	mc_lst->next = NULL;
@@ -173,7 +173,7 @@ int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
 	} else
 		dev = __dev_get_by_index(net, ifindex);
 
-	if (dev == NULL) {
+	if (!dev) {
 		sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
 		return -ENODEV;
 	}
@@ -823,7 +823,7 @@ static struct ifmcaddr6 *mca_alloc(struct inet6_dev *idev,
 	struct ifmcaddr6 *mc;
 
 	mc = kzalloc(sizeof(*mc), GFP_ATOMIC);
-	if (mc == NULL)
+	if (!mc)
 		return NULL;
 
 	setup_timer(&mc->mca_timer, igmp6_timer_handler, (unsigned long)mc);
@@ -860,7 +860,7 @@ int ipv6_dev_mc_inc(struct net_device *dev, const struct in6_addr *addr)
 	/* we need to take a reference on idev */
 	idev = in6_dev_get(dev);
 
-	if (idev == NULL)
+	if (!idev)
 		return -EINVAL;
 
 	write_lock_bh(&idev->lock);
@@ -1328,7 +1328,7 @@ int igmp6_event_query(struct sk_buff *skb)
 		return -EINVAL;
 
 	idev = __in6_dev_get(skb->dev);
-	if (idev == NULL)
+	if (!idev)
 		return 0;
 
 	mld = (struct mld_msg *)icmp6_hdr(skb);
@@ -1443,7 +1443,7 @@ int igmp6_event_report(struct sk_buff *skb)
 		return -EINVAL;
 
 	idev = __in6_dev_get(skb->dev);
-	if (idev == NULL)
+	if (!idev)
 		return -ENODEV;
 
 	/*
@@ -1962,7 +1962,7 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
 
 	skb = sock_alloc_send_skb(sk, hlen + tlen + full_len, 1, &err);
 
-	if (skb == NULL) {
+	if (!skb) {
 		rcu_read_lock();
 		IP6_INC_STATS(net, __in6_dev_get(dev),
 			      IPSTATS_MIB_OUTDISCARDS);
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 247ad7c..482dfb9 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -311,7 +311,7 @@ static int ndisc_constructor(struct neighbour *neigh)
 	bool is_multicast = ipv6_addr_is_multicast(addr);
 
 	in6_dev = in6_dev_get(dev);
-	if (in6_dev == NULL) {
+	if (!in6_dev) {
 		return -EINVAL;
 	}
 
@@ -356,7 +356,7 @@ static int pndisc_constructor(struct pneigh_entry *n)
 	struct in6_addr maddr;
 	struct net_device *dev = n->dev;
 
-	if (dev == NULL || __in6_dev_get(dev) == NULL)
+	if (!dev || !__in6_dev_get(dev))
 		return -EINVAL;
 	addrconf_addr_solict_mult(addr, &maddr);
 	ipv6_dev_mc_inc(dev, &maddr);
@@ -369,7 +369,7 @@ static void pndisc_destructor(struct pneigh_entry *n)
 	struct in6_addr maddr;
 	struct net_device *dev = n->dev;
 
-	if (dev == NULL || __in6_dev_get(dev) == NULL)
+	if (!dev || !__in6_dev_get(dev))
 		return;
 	addrconf_addr_solict_mult(addr, &maddr);
 	ipv6_dev_mc_dec(dev, &maddr);
@@ -560,7 +560,7 @@ void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
 	int optlen = 0;
 	struct nd_msg *msg;
 
-	if (saddr == NULL) {
+	if (!saddr) {
 		if (ipv6_get_lladdr(dev, &addr_buf,
 				   (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
 			return;
@@ -1030,13 +1030,13 @@ static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
 	size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
 
 	skb = nlmsg_new(msg_size, GFP_ATOMIC);
-	if (skb == NULL) {
+	if (!skb) {
 		err = -ENOBUFS;
 		goto errout;
 	}
 
 	nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
-	if (nlh == NULL) {
+	if (!nlh) {
 		goto nla_put_failure;
 	}
 
@@ -1104,7 +1104,7 @@ static void ndisc_router_discovery(struct sk_buff *skb)
 	 */
 
 	in6_dev = __in6_dev_get(skb->dev);
-	if (in6_dev == NULL) {
+	if (!in6_dev) {
 		ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
 			  skb->dev->name);
 		return;
@@ -1199,11 +1199,11 @@ static void ndisc_router_discovery(struct sk_buff *skb)
 
 	ND_PRINTK(3, info, "RA: rt: %p  lifetime: %d, for dev: %s\n",
 		  rt, lifetime, skb->dev->name);
-	if (rt == NULL && lifetime) {
+	if (!rt && lifetime) {
 		ND_PRINTK(3, info, "RA: adding default router\n");
 
 		rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
-		if (rt == NULL) {
+		if (!rt) {
 			ND_PRINTK(0, err,
 				  "RA: %s failed to add default route\n",
 				  __func__);
@@ -1211,7 +1211,7 @@ static void ndisc_router_discovery(struct sk_buff *skb)
 		}
 
 		neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
-		if (neigh == NULL) {
+		if (!neigh) {
 			ND_PRINTK(0, err,
 				  "RA: %s got default router without neighbour\n",
 				  __func__);
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index a5287b3..e33576d 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -172,7 +172,7 @@ static bool ipv6_raw_deliver(struct sk_buff *skb, int nexthdr)
 	read_lock(&raw_v6_hashinfo.lock);
 	sk = sk_head(&raw_v6_hashinfo.ht[hash]);
 
-	if (sk == NULL)
+	if (!sk)
 		goto out;
 
 	net = dev_net(skb->dev);
@@ -630,7 +630,7 @@ static int rawv6_send_hdrinc(struct sock *sk, struct msghdr *msg, int length,
 	skb = sock_alloc_send_skb(sk,
 				  length + hlen + tlen + 15,
 				  flags & MSG_DONTWAIT, &err);
-	if (skb == NULL)
+	if (!skb)
 		goto error;
 	skb_reserve(skb, hlen);
 
@@ -789,7 +789,7 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 			fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
 			if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
 				flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
-				if (flowlabel == NULL)
+				if (!flowlabel)
 					return -EINVAL;
 			}
 		}
@@ -831,13 +831,13 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 		}
 		if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
 			flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
-			if (flowlabel == NULL)
+			if (!flowlabel)
 				return -EINVAL;
 		}
 		if (!(opt->opt_nflen|opt->opt_flen))
 			opt = NULL;
 	}
-	if (opt == NULL)
+	if (!opt)
 		opt = np->opt;
 	if (flowlabel)
 		opt = fl6_merge_options(&opt_space, flowlabel, opt);
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index d7d70e6..24fbc0a 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -430,7 +430,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
 		int i, plen = 0;
 
 		clone = alloc_skb(0, GFP_ATOMIC);
-		if (clone == NULL)
+		if (!clone)
 			goto out_oom;
 		clone->next = head->next;
 		head->next = clone;
@@ -632,7 +632,7 @@ static int __net_init ip6_frags_ns_sysctl_register(struct net *net)
 	table = ip6_frags_ns_ctl_table;
 	if (!net_eq(net, &init_net)) {
 		table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL);
-		if (table == NULL)
+		if (!table)
 			goto err_alloc;
 
 		table[0].data = &net->ipv6.frags.high_thresh;
@@ -648,7 +648,7 @@ static int __net_init ip6_frags_ns_sysctl_register(struct net *net)
 	}
 
 	hdr = register_net_sysctl(net, "net/ipv6", table);
-	if (hdr == NULL)
+	if (!hdr)
 		goto err_reg;
 
 	net->ipv6.sysctl.frags_hdr = hdr;
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 58c0e6a..fe742fa 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1476,7 +1476,7 @@ static int ip6_convert_metrics(struct mx6_config *mxc,
 	int remaining;
 	u32 *mp;
 
-	if (cfg->fc_mx == NULL)
+	if (!cfg->fc_mx)
 		return 0;
 
 	mp = kzalloc(sizeof(u32) * RTAX_MAX, GFP_KERNEL);
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index e4cbd57..c61ed24 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -251,7 +251,7 @@ static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
 
 	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 			   ipip6_tunnel_setup);
-	if (dev == NULL)
+	if (!dev)
 		return NULL;
 
 	dev_net_set(dev, net);
@@ -555,7 +555,7 @@ static int ipip6_err(struct sk_buff *skb, u32 info)
 				skb->dev,
 				iph->daddr,
 				iph->saddr);
-	if (t == NULL)
+	if (!t)
 		goto out;
 
 	if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
@@ -838,7 +838,7 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 		if (skb_dst(skb))
 			neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
 
-		if (neigh == NULL) {
+		if (!neigh) {
 			net_dbg_ratelimited("nexthop == NULL\n");
 			goto tx_error;
 		}
@@ -867,7 +867,7 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 		if (skb_dst(skb))
 			neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
 
-		if (neigh == NULL) {
+		if (!neigh) {
 			net_dbg_ratelimited("nexthop == NULL\n");
 			goto tx_error;
 		}
@@ -1158,7 +1158,7 @@ ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 				break;
 			}
 			t = ipip6_tunnel_locate(net, &p, 0);
-			if (t == NULL)
+			if (!t)
 				t = netdev_priv(dev);
 		}
 
@@ -1242,7 +1242,7 @@ ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 				goto done;
 			err = -ENOENT;
 			t = ipip6_tunnel_locate(net, &p, 0);
-			if (t == NULL)
+			if (!t)
 				goto done;
 			err = -EPERM;
 			if (t == netdev_priv(sitn->fb_tunnel_dev))
diff --git a/net/ipv6/sysctl_net_ipv6.c b/net/ipv6/sysctl_net_ipv6.c
index 30f5a4a..abcc79f 100644
--- a/net/ipv6/sysctl_net_ipv6.c
+++ b/net/ipv6/sysctl_net_ipv6.c
@@ -179,7 +179,7 @@ int ipv6_sysctl_register(void)
 	int err = -ENOMEM;
 
 	ip6_header = register_net_sysctl(&init_net, "net/ipv6", ipv6_rotable);
-	if (ip6_header == NULL)
+	if (!ip6_header)
 		goto out;
 
 	err = register_pernet_subsys(&ipv6_sysctl_net_ops);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index cbdf691..a8a74d3 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -141,7 +141,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 		if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
 			struct ip6_flowlabel *flowlabel;
 			flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
-			if (flowlabel == NULL)
+			if (!flowlabel)
 				return -EINVAL;
 			fl6_sock_release(flowlabel);
 		}
@@ -247,7 +247,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 		goto failure;
 	}
 
-	if (saddr == NULL) {
+	if (!saddr) {
 		saddr = &fl6.saddr;
 		sk->sk_v6_rcv_saddr = *saddr;
 	}
@@ -412,7 +412,7 @@ static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 		/* Only in fast or simultaneous open. If a fast open socket is
 		 * is already accepted it is treated as a connected one below.
 		 */
-		if (fastopen && fastopen->sk == NULL)
+		if (fastopen && !fastopen->sk)
 			break;
 
 		if (!sock_owned_by_user(sk)) {
@@ -750,7 +750,7 @@ static void tcp_v6_send_response(struct sock *sk, struct sk_buff *skb, u32 seq,
 
 	buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
 			 GFP_ATOMIC);
-	if (buff == NULL)
+	if (!buff)
 		return;
 
 	skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
@@ -1008,7 +1008,7 @@ static struct sock *tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 
 		newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
 
-		if (newsk == NULL)
+		if (!newsk)
 			return NULL;
 
 		newtcp6sk = (struct tcp6_sock *)newsk;
@@ -1065,7 +1065,7 @@ static struct sock *tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 	}
 
 	newsk = tcp_create_openreq_child(sk, req, skb);
-	if (newsk == NULL)
+	if (!newsk)
 		goto out_nonewsk;
 
 	/*
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 7fe0329..58efd2c 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -550,7 +550,7 @@ void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 
 	sk = __udp6_lib_lookup(net, daddr, uh->dest,
 			       saddr, uh->source, inet6_iif(skb), udptable);
-	if (sk == NULL) {
+	if (!sk) {
 		ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
 				   ICMP6_MIB_INERRORS);
 		return;
@@ -749,7 +749,7 @@ static void flush_stack(struct sock **stack, unsigned int count,
 
 	for (i = 0; i < count; i++) {
 		sk = stack[i];
-		if (likely(skb1 == NULL))
+		if (likely(!skb1))
 			skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
 		if (!skb1) {
 			atomic_inc(&sk->sk_drops);
@@ -1207,7 +1207,7 @@ do_udp_sendmsg:
 			fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
 			if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
 				flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
-				if (flowlabel == NULL)
+				if (!flowlabel)
 					return -EINVAL;
 			}
 		}
@@ -1255,14 +1255,14 @@ do_udp_sendmsg:
 		}
 		if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
 			flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
-			if (flowlabel == NULL)
+			if (!flowlabel)
 				return -EINVAL;
 		}
 		if (!(opt->opt_nflen|opt->opt_flen))
 			opt = NULL;
 		connected = 0;
 	}
-	if (opt == NULL)
+	if (!opt)
 		opt = np->opt;
 	if (flowlabel)
 		opt = fl6_merge_options(&opt_space, flowlabel, opt);
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index 11dbcc1..91d934c 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -370,7 +370,7 @@ static void __net_exit xfrm6_net_exit(struct net *net)
 {
 	struct ctl_table *table;
 
-	if (net->ipv6.sysctl.xfrm6_hdr == NULL)
+	if (!net->ipv6.sysctl.xfrm6_hdr)
 		return;
 
 	table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg;
-- 
1.9.1

[PATCH net-next 2/2] ipv6: coding style: comparison for inequality with NULL

[Ian Morris]

The ipv6 code uses a mixture of coding styles. In some instances check for NULL
pointer is done as x != NULL and sometimes as x. x is preferred according to
checkpatch and this patch makes the code consistent by adopting the latter
form.

No changes detected by objdiff.

Signed-off-by: Ian Morris <ipm@chirality.org.uk>
---
 net/ipv6/addrconf_core.c |  2 +-
 net/ipv6/af_inet6.c      |  6 +++---
 net/ipv6/ip6_fib.c       |  4 ++--
 net/ipv6/ip6_flowlabel.c |  6 +++---
 net/ipv6/ip6_gre.c       |  6 +++---
 net/ipv6/ip6_input.c     |  2 +-
 net/ipv6/ip6_offload.c   |  2 +-
 net/ipv6/ip6_output.c    |  2 +-
 net/ipv6/ip6_tunnel.c    |  4 ++--
 net/ipv6/ip6_vti.c       |  6 +++---
 net/ipv6/ip6mr.c         |  2 +-
 net/ipv6/mcast.c         | 16 ++++++++--------
 net/ipv6/raw.c           |  4 ++--
 net/ipv6/reassembly.c    |  2 +-
 net/ipv6/sit.c           | 10 +++++-----
 net/ipv6/tcp_ipv6.c      |  8 ++++----
 net/ipv6/udp.c           |  4 ++--
 17 files changed, 43 insertions(+), 43 deletions(-)

diff --git a/net/ipv6/addrconf_core.c b/net/ipv6/addrconf_core.c
index 98cc4cd..d873cee 100644
--- a/net/ipv6/addrconf_core.c
+++ b/net/ipv6/addrconf_core.c
@@ -140,7 +140,7 @@ void in6_dev_finish_destroy(struct inet6_dev *idev)
 	struct net_device *dev = idev->dev;
 
 	WARN_ON(!list_empty(&idev->addr_list));
-	WARN_ON(idev->mc_list != NULL);
+	WARN_ON(idev->mc_list);
 	WARN_ON(timer_pending(&idev->rs_timer));
 
 #ifdef NET_REFCNT_DEBUG
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 0e48897..eef63b3 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -413,11 +413,11 @@ void inet6_destroy_sock(struct sock *sk)
 	/* Release rx options */
 
 	skb = xchg(&np->pktoptions, NULL);
-	if (skb != NULL)
+	if (skb)
 		kfree_skb(skb);
 
 	skb = xchg(&np->rxpmtu, NULL);
-	if (skb != NULL)
+	if (skb)
 		kfree_skb(skb);
 
 	/* Free flowlabels */
@@ -426,7 +426,7 @@ void inet6_destroy_sock(struct sock *sk)
 	/* Free tx options */
 
 	opt = xchg(&np->opt, NULL);
-	if (opt != NULL)
+	if (opt)
 		sock_kfree_s(sk, opt, opt->tot_len);
 }
 EXPORT_SYMBOL_GPL(inet6_destroy_sock);
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 263ef41..96dbfff 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -1206,7 +1206,7 @@ static struct fib6_node *fib6_repair_tree(struct net *net,
 
 		WARN_ON(fn->fn_flags & RTN_RTINFO);
 		WARN_ON(fn->fn_flags & RTN_TL_ROOT);
-		WARN_ON(fn->leaf != NULL);
+		WARN_ON(fn->leaf);
 
 		children = 0;
 		child = NULL;
@@ -1361,7 +1361,7 @@ int fib6_del(struct rt6_info *rt, struct nl_info *info)
 
 #if RT6_DEBUG >= 2
 	if (rt->dst.obsolete > 0) {
-		WARN_ON(fn != NULL);
+		WARN_ON(fn);
 		return -ENOENT;
 	}
 #endif
diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index 3f54ac5..d491125 100644
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -219,7 +219,7 @@ static struct ip6_flowlabel *fl_intern(struct net *net,
 		 * with the same label can only appear on another sock
 		 */
 		lfl = __fl_lookup(net, fl->label);
-		if (lfl != NULL) {
+		if (lfl) {
 			atomic_inc(&lfl->users);
 			spin_unlock_bh(&ip6_fl_lock);
 			return lfl;
@@ -300,7 +300,7 @@ struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
 	if (!fopt || fopt->opt_flen == 0)
 		return fl_opt;
 
-	if (fl_opt != NULL) {
+	if (fl_opt) {
 		opt_space->hopopt = fl_opt->hopopt;
 		opt_space->dst0opt = fl_opt->dst0opt;
 		opt_space->srcrt = fl_opt->srcrt;
@@ -661,7 +661,7 @@ release:
 			goto done;
 
 		fl1 = fl_intern(net, fl, freq.flr_label);
-		if (fl1 != NULL)
+		if (fl1)
 			goto recheck;
 
 		if (!freq.flr_label) {
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index aa9ea6e..67e014d 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -223,7 +223,7 @@ static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
 		}
 	}
 
-	if (cand != NULL)
+	if (cand)
 		return cand;
 
 	dev = ign->fb_tunnel_dev;
@@ -1105,7 +1105,7 @@ static int ip6gre_tunnel_ioctl(struct net_device *dev,
 		t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
 
 		if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
-			if (t != NULL) {
+			if (t) {
 				if (t->dev != dev) {
 					err = -EEXIST;
 					break;
@@ -1313,7 +1313,7 @@ static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
 
 			t = rtnl_dereference(ign->tunnels[prio][h]);
 
-			while (t != NULL) {
+			while (t) {
 				/* If dev is in the same netns, it has already
 				 * been added to the list by the previous loop.
 				 */
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index aacdcb4..fb97f7f 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -221,7 +221,7 @@ resubmit:
 
 	raw = raw6_local_deliver(skb, nexthdr);
 	ipprot = rcu_dereference(inet6_protos[nexthdr]);
-	if (ipprot != NULL) {
+	if (ipprot) {
 		int ret;
 
 		if (ipprot->flags & INET6_PROTO_FINAL) {
diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
index 46d452a..e893cd1 100644
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -124,7 +124,7 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
 			unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
 			fptr = (struct frag_hdr *)((u8 *)ipv6h + unfrag_ip6hlen);
 			fptr->frag_off = htons(offset);
-			if (skb->next != NULL)
+			if (skb->next)
 				fptr->frag_off |= htons(IP6_MF);
 			offset += (ntohs(ipv6h->payload_len) -
 				   sizeof(struct frag_hdr));
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 8b6d402..84c58da 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -657,7 +657,7 @@ int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
 				fh->nexthdr = nexthdr;
 				fh->reserved = 0;
 				fh->frag_off = htons(offset);
-				if (frag->next != NULL)
+				if (frag->next)
 					fh->frag_off |= htons(IP6_MF);
 				fh->identification = frag_id;
 				ipv6_hdr(frag)->payload_len =
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 6740206..0c68012 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -807,7 +807,7 @@ static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol,
 
 	rcu_read_lock();
 	t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
-	if (t != NULL) {
+	if (t) {
 		struct pcpu_sw_netstats *tstats;
 
 		tproto = ACCESS_ONCE(t->parms.proto);
@@ -1815,7 +1815,7 @@ static void __net_exit ip6_tnl_destroy_tunnels(struct net *net)
 
 	for (h = 0; h < HASH_SIZE; h++) {
 		t = rtnl_dereference(ip6n->tnls_r_l[h]);
-		while (t != NULL) {
+		while (t) {
 			/* If dev is in the same netns, it has already
 			 * been added to the list by the previous loop.
 			 */
diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index a045d54..1ec5b4a 100644
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -305,7 +305,7 @@ static int vti6_rcv(struct sk_buff *skb)
 
 	rcu_read_lock();
 	t = vti6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
-	if (t != NULL) {
+	if (t) {
 		if (t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) {
 			rcu_read_unlock();
 			goto discard;
@@ -736,7 +736,7 @@ vti6_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 		vti6_parm_from_user(&p1, &p);
 		t = vti6_locate(net, &p1, cmd == SIOCADDTUNNEL);
 		if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
-			if (t != NULL) {
+			if (t) {
 				if (t->dev != dev) {
 					err = -EEXIST;
 					break;
@@ -1027,7 +1027,7 @@ static void __net_exit vti6_destroy_tunnels(struct vti6_net *ip6n)
 
 	for (h = 0; h < HASH_SIZE; h++) {
 		t = rtnl_dereference(ip6n->tnls_r_l[h]);
-		while (t != NULL) {
+		while (t) {
 			unregister_netdevice_queue(t->dev, &list);
 			t = rtnl_dereference(t->next);
 		}
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index ebb0514..ff883c9 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -305,7 +305,7 @@ static struct mr6_table *ip6mr_new_table(struct net *net, u32 id)
 	unsigned int i;
 
 	mrt = ip6mr_get_table(net, id);
-	if (mrt != NULL)
+	if (mrt)
 		return mrt;
 
 	mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 3017c4a..fac1f27 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -226,7 +226,7 @@ int ipv6_sock_mc_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
 			*lnk = mc_lst->next;
 
 			dev = __dev_get_by_index(net, mc_lst->ifindex);
-			if (dev != NULL) {
+			if (dev) {
 				struct inet6_dev *idev = __in6_dev_get(dev);
 
 				(void) ip6_mc_leave_src(sk, mc_lst, idev);
@@ -2611,7 +2611,7 @@ static struct ifmcaddr6 *igmp6_mc_get_next(struct seq_file *seq, struct ifmcaddr
 
 	im = im->next;
 	while (!im) {
-		if (likely(state->idev != NULL))
+		if (likely(state->idev))
 			read_unlock_bh(&state->idev->lock);
 
 		state->dev = next_net_device_rcu(state->dev);
@@ -2657,7 +2657,7 @@ static void igmp6_mc_seq_stop(struct seq_file *seq, void *v)
 {
 	struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);
 
-	if (likely(state->idev != NULL)) {
+	if (likely(state->idev)) {
 		read_unlock_bh(&state->idev->lock);
 		state->idev = NULL;
 	}
@@ -2726,10 +2726,10 @@ static inline struct ip6_sf_list *igmp6_mcf_get_first(struct seq_file *seq)
 			continue;
 		read_lock_bh(&idev->lock);
 		im = idev->mc_list;
-		if (likely(im != NULL)) {
+		if (likely(im)) {
 			spin_lock_bh(&im->mca_lock);
 			psf = im->mca_sources;
-			if (likely(psf != NULL)) {
+			if (likely(psf)) {
 				state->im = im;
 				state->idev = idev;
 				break;
@@ -2750,7 +2750,7 @@ static struct ip6_sf_list *igmp6_mcf_get_next(struct seq_file *seq, struct ip6_s
 		spin_unlock_bh(&state->im->mca_lock);
 		state->im = state->im->next;
 		while (!state->im) {
-			if (likely(state->idev != NULL))
+			if (likely(state->idev))
 				read_unlock_bh(&state->idev->lock);
 
 			state->dev = next_net_device_rcu(state->dev);
@@ -2804,11 +2804,11 @@ static void igmp6_mcf_seq_stop(struct seq_file *seq, void *v)
 	__releases(RCU)
 {
 	struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);
-	if (likely(state->im != NULL)) {
+	if (likely(state->im)) {
 		spin_unlock_bh(&state->im->mca_lock);
 		state->im = NULL;
 	}
-	if (likely(state->idev != NULL)) {
+	if (likely(state->idev)) {
 		read_unlock_bh(&state->idev->lock);
 		state->idev = NULL;
 	}
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index e33576d..79ccdb4 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -367,7 +367,7 @@ void raw6_icmp_error(struct sk_buff *skb, int nexthdr,
 
 	read_lock(&raw_v6_hashinfo.lock);
 	sk = sk_head(&raw_v6_hashinfo.ht[hash]);
-	if (sk != NULL) {
+	if (sk) {
 		/* Note: ipv6_hdr(skb) != skb->data */
 		const struct ipv6hdr *ip6h = (const struct ipv6hdr *)skb->data;
 		saddr = &ip6h->saddr;
@@ -1130,7 +1130,7 @@ static int rawv6_ioctl(struct sock *sk, int cmd, unsigned long arg)
 
 		spin_lock_bh(&sk->sk_receive_queue.lock);
 		skb = skb_peek(&sk->sk_receive_queue);
-		if (skb != NULL)
+		if (skb)
 			amount = skb_tail_pointer(skb) -
 				skb_transport_header(skb);
 		spin_unlock_bh(&sk->sk_receive_queue.lock);
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index 24fbc0a..8ffa2c8 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -552,7 +552,7 @@ static int ipv6_frag_rcv(struct sk_buff *skb)
 
 	fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr,
 		     ip6_frag_ecn(hdr));
-	if (fq != NULL) {
+	if (fq) {
 		int ret;
 
 		spin_lock(&fq->q.lock);
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index c61ed24..92692a7 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -118,7 +118,7 @@ static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
 			return t;
 	}
 	t = rcu_dereference(sitn->tunnels_wc[0]);
-	if ((t != NULL) && (t->dev->flags & IFF_UP))
+	if (t && (t->dev->flags & IFF_UP))
 		return t;
 	return NULL;
 }
@@ -671,7 +671,7 @@ static int ipip6_rcv(struct sk_buff *skb)
 
 	tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 				     iph->saddr, iph->daddr);
-	if (tunnel != NULL) {
+	if (tunnel) {
 		struct pcpu_sw_netstats *tstats;
 
 		if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
@@ -733,7 +733,7 @@ static int ipip_rcv(struct sk_buff *skb)
 	iph = ip_hdr(skb);
 	tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 				     iph->saddr, iph->daddr);
-	if (tunnel != NULL) {
+	if (tunnel) {
 		if (tunnel->parms.iph.protocol != IPPROTO_IPIP &&
 		    tunnel->parms.iph.protocol != 0)
 			goto drop;
@@ -1206,7 +1206,7 @@ ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 		t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
 
 		if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
-			if (t != NULL) {
+			if (t) {
 				if (t->dev != dev) {
 					err = -EEXIST;
 					break;
@@ -1795,7 +1795,7 @@ static void __net_exit sit_destroy_tunnels(struct net *net,
 			struct ip_tunnel *t;
 
 			t = rtnl_dereference(sitn->tunnels[prio][h]);
-			while (t != NULL) {
+			while (t) {
 				/* If dev is in the same netns, it has already
 				 * been added to the list by the previous loop.
 				 */
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index a8a74d3..7cdad84 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -460,7 +460,7 @@ static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst,
 				    &ireq->ir_v6_rmt_addr);
 
 		fl6->daddr = ireq->ir_v6_rmt_addr;
-		if (np->repflow && (ireq->pktopts != NULL))
+		if (np->repflow && ireq->pktopts)
 			fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
 
 		skb_set_queue_mapping(skb, queue_mapping);
@@ -1107,7 +1107,7 @@ static struct sock *tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 
 	/* Clone pktoptions received with SYN */
 	newnp->pktoptions = NULL;
-	if (ireq->pktopts != NULL) {
+	if (ireq->pktopts) {
 		newnp->pktoptions = skb_clone(ireq->pktopts,
 					      sk_gfp_atomic(sk, GFP_ATOMIC));
 		consume_skb(ireq->pktopts);
@@ -1152,7 +1152,7 @@ static struct sock *tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 #ifdef CONFIG_TCP_MD5SIG
 	/* Copy over the MD5 key from the original socket */
 	key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
-	if (key != NULL) {
+	if (key) {
 		/* We're using one, so create a matching key
 		 * on the newsk structure. If we fail to get
 		 * memory, then we end up not copying the key
@@ -1475,7 +1475,7 @@ do_time_wait:
 					    &ipv6_hdr(skb)->saddr, th->source,
 					    &ipv6_hdr(skb)->daddr,
 					    ntohs(th->dest), tcp_v6_iif(skb));
-		if (sk2 != NULL) {
+		if (sk2) {
 			struct inet_timewait_sock *tw = inet_twsk(sk);
 			inet_twsk_deschedule(tw, &tcp_death_row);
 			inet_twsk_put(tw);
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 58efd2c..120aff9 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -648,7 +648,7 @@ int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 
 		/* if we're overly short, let UDP handle it */
 		encap_rcv = ACCESS_ONCE(up->encap_rcv);
-		if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) {
+		if (skb->len > sizeof(struct udphdr) && encap_rcv) {
 			int ret;
 
 			/* Verify checksum before giving to encap */
@@ -899,7 +899,7 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
 	 * for sock caches... i'll skip this for now.
 	 */
 	sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
-	if (sk != NULL) {
+	if (sk) {
 		int ret;
 
 		if (!uh->check && !udp_sk(sk)->no_check6_rx) {
-- 
1.9.1

Re: [PATCH net-next 0/2] ipv6: coding style - comparisons with NULL

[Joe Perches]

On Sun, 2015-03-29 at 14:00 +0100, Ian Morris wrote:
> The IPV6 code uses multiple different styles when comparing with NULL
> (I.e. x == NULL and !x as well as x != NULL and x). Generally the
> latter form is preferred according to checkpatch and so this changes
> aligns the code to this style. 

Hello Ian.

While I prefer this style, it can be a "maintainer's choice"
preference and this might be a bit contentious to some.

It might be nice to show the relative counts of each form
before this change to show the relative counts use of each
form to help establish consensus for the value for this patch.

(Or David could just apply it instead:)

Using coccinelle to check for pointer comparisons with and
without NULL for net/ipv6/*.[ch]:

with NULL:	260
without NULL:	779

So there was a 3:1 preference for the bare form.

(and for net/ipv4/*.[ch] it's closer to 4:1)

with NULL:	276
without NULL:	914

(trivial cocci script below)
@@
type A;
A *b;
@@

* b == NULL

@@
type A;
A *b;
@@

* b != NULL

Re: [PATCH net-next 0/2] ipv6: coding style - comparisons with NULL

[Ian Morris]

Hello Joe,

Many thanks for your invaluable feedback, as ever!

I was aware this one has the potential to be a somewhat controversial 
topic and whilst my analysis was not quite as scientific as yours I too 
had detected the preference for the shorter form hence the reason for 
adopting that style : however your stats are a great illustration so 
thanks for putting them forward.

I guess the thing with coding style is precisely that : it's a style 
rather than something that is correct or not but my perspective (FWIW, 
probably not that much!) is that we should at least try to be consistent 
within an area of code. As such I can totally understand one area using 
NULL and another not given the size of the kernel as a whole but I 
thought it worth trying to align stuff within IPV6.

IPV6 is a particular interest for me but I'd be happy to cook up a 
similar patch for IPV4 if there's interest.

Thanks again,

Ian.

On 29/03/15 18:36, Joe Perches wrote:
> On Sun, 2015-03-29 at 14:00 +0100, Ian Morris wrote:
>> The IPV6 code uses multiple different styles when comparing with NULL
>> (I.e. x == NULL and !x as well as x != NULL and x). Generally the
>> latter form is preferred according to checkpatch and so this changes
>> aligns the code to this style.
> Hello Ian.
>
> While I prefer this style, it can be a "maintainer's choice"
> preference and this might be a bit contentious to some.
>
> It might be nice to show the relative counts of each form
> before this change to show the relative counts use of each
> form to help establish consensus for the value for this patch.
>
> (Or David could just apply it instead:)
>
> Using coccinelle to check for pointer comparisons with and
> without NULL for net/ipv6/*.[ch]:
>
> with NULL:	260
> without NULL:	779
>
> So there was a 3:1 preference for the bare form.
>
> (and for net/ipv4/*.[ch] it's closer to 4:1)
>
> with NULL:	276
> without NULL:	914
>
> (trivial cocci script below)
> @@
> type A;
> A *b;
> @@
>
> * b == NULL
>
> @@
> type A;
> A *b;
> @@
>
> * b != NULL
>
>
>

Re: [PATCH net-next 0/2] ipv6: coding style - comparisons with NULL

[Joe Perches]

On Tue, 2015-03-31 at 17:39 +0100, Ian Morris wrote:
> IPV6 is a particular interest for me but I'd be happy to cook up a 
> similar patch for IPV4 if there's interest.

I think that'd be nice.

Here's a little script for most of them:

$ ./scripts/checkpatch.pl -f --types=COMPARISON_TO_NULL --strict --fix-inplace net/ipv4/*.[ch]

cheers, Joe

Re: [PATCH net-next 0/2] ipv6: coding style - comparisons with NULL

[David Miller]

From: Ian Morris <ipm@chirality.org.uk>
Date: Sun, 29 Mar 2015 14:00:03 +0100

> The following patches address some coding style issues only. No
> functional changes and no changes detected by objdiff.
>
> The IPV6 code uses multiple different styles when comparing with
> NULL (I.e. x == NULL and !x as well as x != NULL and x). Generally
> the latter form is preferred according to checkpatch and so this
> changes aligns the code to this style.

Please trim your commit message lines to 80 columns in the future.

It is _extremely_ irritating to see how people type commit messages
into GUI or similar tools, and then expect that the rest of the world
will see the message formatted in the same exact way.

The only reliable way to edit and format commit log messages, so that
everyone sees something consistent, is to do so in a pure plain ASCII
text editor and use newlines to break columns at ~80 columns.

Anyways, I've applied this series, thanks.

[PATCH] checkpatch/SubmittingPatches: Suggest line wrapping commit messages at 72 columns

[Joe Perches]

Commit messages are sometimes overly long.
Suggest line wrapping at 72 columns.

Add a checkpatch test for long commit messages as well.

Signed-off-by: Joe Perches <joe@perches.com>
---
On Tue, 2015-03-31 at 11:16 -0700, Joe Perches wrote:
> On Tue, 2015-03-31 at 13:53 -0400, David Miller wrote:
> > From: Ian Morris <ipm@chirality.org.uk>
> > > The following patches address some coding style issues only. No
> > > functional changes and no changes detected by objdiff.
> > >
> > > The IPV6 code uses multiple different styles when comparing with
> > > NULL (I.e. x == NULL and !x as well as x != NULL and x). Generally
> > > the latter form is preferred according to checkpatch and so this
> > > changes aligns the code to this style.
> > 
> > Please trim your commit message lines to 80 columns in the future.
> []
> > The only reliable way to edit and format commit log messages, so that
> > everyone sees something consistent, is to do so in a pure plain ASCII
> > text editor and use newlines to break columns at ~80 columns.
> 
> I think ~72 is the preferred # as by default git commit log output
> is indented a few chars.

 Documentation/SubmittingPatches | 4 ++--
 scripts/checkpatch.pl           | 9 +++++++++
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/Documentation/SubmittingPatches b/Documentation/SubmittingPatches
index 447671b..c9de1c3 100644
--- a/Documentation/SubmittingPatches
+++ b/Documentation/SubmittingPatches
@@ -614,8 +614,8 @@ The canonical patch message body contains the following:
 
   - An empty line.
 
-  - The body of the explanation, which will be copied to the
-    permanent changelog to describe this patch.
+  - The body of the explanation, line wrapped at 72 columns, which will
+    be copied to the permanent changelog to describe this patch.
 
   - The "Signed-off-by:" lines, described above, which will
     also go in the changelog.
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index d54a814..62a7be5 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -1898,6 +1898,7 @@ sub process {
 
 	my $in_header_lines = $file ? 0 : 1;
 	my $in_commit_log = 0;		#Scanning lines before patch
+	my $commit_log_long_line = 0;
 	my $reported_maintainer_file = 0;
 	my $non_utf8_charset = 0;
 
@@ -2233,6 +2234,14 @@ sub process {
 			      "Remove Gerrit Change-Id's before submitting upstream.\n" . $herecurr);
 		}
 
+# Check for line lengths > 72 in commit log, warn once
+		if ($in_commit_log && !$commit_log_long_line &&
+		    length($line) > 72) {
+			WARN("COMMIT_LOG_LONG_LINE",
+			     "Possible unwrapped commit description (prefer maximum 72 chars per line)\n" . $herecurr);
+			$commit_log_long_line = 1;
+		}
+
 # Check for git id commit length and improperly formed commit descriptions
 		if ($in_commit_log && $line =~ /\b(c)ommit\s+([0-9a-f]{5,})/i) {
 			my $init_char = $1;

Re: [PATCH] checkpatch/SubmittingPatches: Suggest line wrapping commit messages at 72 columns

[David Miller]

From: Joe Perches <joe@perches.com>
Date: Tue, 31 Mar 2015 11:40:25 -0700

> Commit messages are sometimes overly long.
> Suggest line wrapping at 72 columns.
> 
> Add a checkpatch test for long commit messages as well.
> 
> Signed-off-by: Joe Perches <joe@perches.com>

Acked-by: David S. Miller <davem@davemloft.net>

Re: [PATCH] checkpatch/SubmittingPatches: Suggest line wrapping commit messages at 72 columns

[Andrew Morton]

On Tue, 31 Mar 2015 11:40:25 -0700 Joe Perches <joe@perches.com> wrote:

> Commit messages are sometimes overly long.
> Suggest line wrapping at 72 columns.

waah, I use 75 and this patch has ruined my life.

Is there some way I can disable just this check without patching
checkpatch?  I suspect a lot of people will be interested in doing
this ;)

Re: [PATCH] checkpatch/SubmittingPatches: Suggest line wrapping commit messages at 72 columns

[Joe Perches]

On Wed, 2015-04-01 at 12:20 -0700, Andrew Morton wrote:
> On Tue, 31 Mar 2015 11:40:25 -0700 Joe Perches <joe@perches.com> wrote:
> 
> > Commit messages are sometimes overly long.
> > Suggest line wrapping at 72 columns.
> 
> waah, I use 75 and this patch has ruined my life.

hmm... 1/4/15 or is it 4/1/15?

> Is there some way I can disable just this check without patching
> checkpatch?  I suspect a lot of people will be interested in doing
> this ;)

You could s/72/75/.  I won't care.

Using "./scripts/checkpatch.pl --ignore=commit_log_long_line"
would work too.

Re: [PATCH] checkpatch/SubmittingPatches: Suggest line wrapping commit messages at 72 columns

[Jonathan Corbet]

On Wed, 1 Apr 2015 12:20:01 -0700
Andrew Morton <akpm@linux-foundation.org> wrote:

> waah, I use 75 and this patch has ruined my life.
> 
> Is there some way I can disable just this check without patching
> checkpatch?  I suspect a lot of people will be interested in doing
> this ;)

I use 75 too, FWIW.

It seems to me that nobody out there complains about 75-character lines
in commit logs; it's the 120-character lines that irritate people.  I
would suggest that this limit could be set to 75 (or even, say, 77) and
still achieve its real purpose while leaving far fewer ruined lives in its
wake. 

jon

Re: [PATCH] checkpatch/SubmittingPatches: Suggest line wrapping commit messages at 72 columns

[Joe Perches]

On Wed, 2015-04-01 at 21:36 +0200, Jonathan Corbet wrote:
> On Wed, 1 Apr 2015 12:20:01 -0700
> Andrew Morton <akpm@linux-foundation.org> wrote:
> > waah, I use 75 and this patch has ruined my life.

crybaby... :)

> I use 75 too, FWIW.
> 
> It seems to me that nobody out there complains about 75-character lines
> in commit logs; it's the 120-character lines that irritate people.  I
> would suggest that this limit could be set to 75 (or even, say, 77)

77 might be one too many.

git log has a default 4 space indent of the commit message so
75 or 76 would still fit an 80 column screen.

> and
> still achieve its real purpose while leaving far fewer ruined lives in its
> wake. 

I don't wanna be held liable for that ruination, thanks.

Re: [PATCH] checkpatch/SubmittingPatches: Suggest line wrapping commit messages at 72 columns

[Andrew Morton]

On Wed, 01 Apr 2015 13:09:29 -0700 Joe Perches <joe@perches.com> wrote:

> On Wed, 2015-04-01 at 21:36 +0200, Jonathan Corbet wrote:
> > On Wed, 1 Apr 2015 12:20:01 -0700
> > Andrew Morton <akpm@linux-foundation.org> wrote:
> > > waah, I use 75 and this patch has ruined my life.
> 
> crybaby... :)

I'm very sensitive.

> > I use 75 too, FWIW.
> > 
> > It seems to me that nobody out there complains about 75-character lines
> > in commit logs; it's the 120-character lines that irritate people.  I
> > would suggest that this limit could be set to 75 (or even, say, 77)
> 
> 77 might be one too many.
> 
> git log has a default 4 space indent of the commit message so
> 75 or 76 would still fit an 80 column screen.

That's a good point.  Good enough to be in a changelog ;)

76 sounds a bit risky - I don't think I trust every output device to
dtrt with 80-column text.  I might be wrong about that.  75 would save
my handkerchiefs.

[PATCH V2] checkpatch/SubmittingPatches: Suggest line wrapping commit messages at 75 columns

[Joe Perches]

Commit messages lines are sometimes overly long.

Suggest line wrapping at 75 columns so the default git
commit log indentation of 4 plus the commit message text
still fits on an 80 column screen.

Add a checkpatch test for long commit messages lines too.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: David Miller <davem@davmloft.net>
---

V2: avoid Andrew Morton's colicky crying binges...

On Wed, 2015-04-01 at 13:18 -0700, Andrew Morton wrote:
> On Wed, 01 Apr 2015 13:09:29 -0700 Joe Perches <joe@perches.com> wrote:
> I'm very sensitive.

A poet too no doubt.

> > git log has a default 4 space indent of the commit message so
> > 75 or 76 would still fit an 80 column screen.
> 
> That's a good point.  Good enough to be in a changelog ;)

If you're going to change it, make sure to DTRT.

Or just take this one...

 Documentation/SubmittingPatches | 4 ++--
 scripts/checkpatch.pl           | 9 +++++++++
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/Documentation/SubmittingPatches b/Documentation/SubmittingPatches
index 447671b..c9de1c3 100644
--- a/Documentation/SubmittingPatches
+++ b/Documentation/SubmittingPatches
@@ -614,8 +614,8 @@ The canonical patch message body contains the following:
 
   - An empty line.
 
-  - The body of the explanation, which will be copied to the
-    permanent changelog to describe this patch.
+  - The body of the explanation, line wrapped at 75 columns, which will
+    be copied to the permanent changelog to describe this patch.
 
   - The "Signed-off-by:" lines, described above, which will
     also go in the changelog.
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index d54a814..62a7be5 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -1898,6 +1898,7 @@ sub process {
 
 	my $in_header_lines = $file ? 0 : 1;
 	my $in_commit_log = 0;		#Scanning lines before patch
+	my $commit_log_long_line = 0;
 	my $reported_maintainer_file = 0;
 	my $non_utf8_charset = 0;
 
@@ -2233,6 +2234,14 @@ sub process {
 			      "Remove Gerrit Change-Id's before submitting upstream.\n" . $herecurr);
 		}
 
+# Check for line lengths > 75 in commit log, warn once
+		if ($in_commit_log && !$commit_log_long_line &&
+		    length($line) > 75) {
+			WARN("COMMIT_LOG_LONG_LINE",
+			     "Possible unwrapped commit description (prefer a maximum 75 chars per line)\n" . $herecurr);
+			$commit_log_long_line = 1;
+		}
+
 # Check for git id commit length and improperly formed commit descriptions
 		if ($in_commit_log && $line =~ /\b(c)ommit\s+([0-9a-f]{5,})/i) {
 			my $init_char = $1;