netns: make struct pernet_operations::id unsigned int

Make struct pernet_operations::id unsigned.

There are 2 reasons to do so:

1)
This field is really an index into an zero based array and
thus is unsigned entity. Using negative value is out-of-bound
access by definition.

2)
On x86_64 unsigned 32-bit data which are mixed with pointers
via array indexing or offsets added or subtracted to pointers
are preffered to signed 32-bit data.

"int" being used as an array index needs to be sign-extended
to 64-bit before being used.

	void f(long *p, int i)
	{
		g(p[i]);
	}

  roughly translates to

	movsx	rsi, esi
	mov	rdi, [rsi+...]
	call 	g

MOVSX is 3 byte instruction which isn't necessary if the variable is
unsigned because x86_64 is zero extending by default.

Now, there is net_generic() function which, you guessed it right, uses
"int" as an array index:

	static inline void *net_generic(const struct net *net, int id)
	{
		...
		ptr = ng->ptr[id - 1];
		...
	}

And this function is used a lot, so those sign extensions add up.

Patch snipes ~1730 bytes on allyesconfig kernel (without all junk
messing with code generation):

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)

Unfortunately some functions actually grow bigger.
This is a semmingly random artefact of code generation with register
allocator being used differently. gcc decides that some variable
needs to live in new r8+ registers and every access now requires REX
prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be
used which is longer than [r8]

However, overall balance is in negative direction:

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
	function                                     old     new   delta
	nfsd4_lock                                  3886    3959     +73
	tipc_link_build_proto_msg                   1096    1140     +44
	mac80211_hwsim_new_radio                    2776    2808     +32
	tipc_mon_rcv                                1032    1058     +26
	svcauth_gss_legacy_init                     1413    1429     +16
	tipc_bcbase_select_primary                   379     392     +13
	nfsd4_exchange_id                           1247    1260     +13
	nfsd4_setclientid_confirm                    782     793     +11
		...
	put_client_renew_locked                      494     480     -14
	ip_set_sockfn_get                            730     716     -14
	geneve_sock_add                              829     813     -16
	nfsd4_sequence_done                          721     703     -18
	nlmclnt_lookup_host                          708     686     -22
	nfsd4_lockt                                 1085    1063     -22
	nfs_get_client                              1077    1050     -27
	tcf_bpf_init                                1106    1076     -30
	nfsd4_encode_fattr                          5997    5930     -67
	Total: Before=154856051, After=154854321, chg -0.00%

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

73 files changed, 80 insertions, 81 deletions

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 89a6b0546804..c68f4fe001d7 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -116,7 +116,7 @@ static LIST_HEAD(dev_list);
 static LIST_HEAD(listen_any_list);
 static DEFINE_MUTEX(lock);
 static struct workqueue_struct *cma_wq;
-static int cma_pernet_id;
+static unsigned int cma_pernet_id;
 
 struct cma_pernet {
 	struct idr tcp_ps;
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 5708f17e4cdf..8029dd4912b6 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -199,7 +199,7 @@ MODULE_PARM_DESC(lp_interval, "The number of seconds between instances where "
 atomic_t netpoll_block_tx = ATOMIC_INIT(0);
 #endif
 
-int bond_net_id __read_mostly;
+unsigned int bond_net_id __read_mostly;
 
 static __be32 arp_target[BOND_MAX_ARP_TARGETS];
 static int arp_ip_count;
diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index 85a423a66478..90dc6b188607 100644
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -43,7 +43,7 @@ struct geneve_net {
 	struct list_head	sock_list;
 };
 
-static int geneve_net_id;
+static unsigned int geneve_net_id;
 
 union geneve_addr {
 	struct sockaddr_in sin;
diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 719d19f35673..98f10c216521 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -77,7 +77,7 @@ struct gtp_dev {
 	struct hlist_head	*addr_hash;
 };
 
-static int gtp_net_id __read_mostly;
+static unsigned int gtp_net_id __read_mostly;
 
 struct gtp_net {
 	struct list_head gtp_dev_list;
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index 5489c0ec1d9a..3d3b1f4339ef 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -204,7 +204,7 @@ static atomic_t ppp_unit_count = ATOMIC_INIT(0);
 static atomic_t channel_count = ATOMIC_INIT(0);
 
 /* per-net private data for this module */
-static int ppp_net_id __read_mostly;
+static unsigned int ppp_net_id __read_mostly;
 struct ppp_net {
 	/* units to ppp mapping */
 	struct idr units_idr;
diff --git a/drivers/net/ppp/pppoe.c b/drivers/net/ppp/pppoe.c
index 4ddae8118c85..f017c72bb7fd 100644
--- a/drivers/net/ppp/pppoe.c
+++ b/drivers/net/ppp/pppoe.c
@@ -95,7 +95,7 @@ static const struct proto_ops pppoe_ops;
 static const struct ppp_channel_ops pppoe_chan_ops;
 
 /* per-net private data for this module */
-static int pppoe_net_id __read_mostly;
+static unsigned int pppoe_net_id __read_mostly;
 struct pppoe_net {
 	/*
 	 * we could use _single_ hash table for all
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 0a3fd675408f..21e92be6e56c 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -52,7 +52,7 @@ static bool log_ecn_error = true;
 module_param(log_ecn_error, bool, 0644);
 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
 
-static int vxlan_net_id;
+static unsigned int vxlan_net_id;
 static struct rtnl_link_ops vxlan_link_ops;
 
 static const u8 all_zeros_mac[ETH_ALEN + 2];
diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index 8f366cc097e6..1293f8494985 100644
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -250,7 +250,7 @@ static inline void hwsim_clear_chanctx_magic(struct ieee80211_chanctx_conf *c)
 	cp->magic = 0;
 }
 
-static int hwsim_net_id;
+static unsigned int hwsim_net_id;
 
 static int hwsim_netgroup;
 
diff --git a/fs/lockd/netns.h b/fs/lockd/netns.h
index 5426189406c1..fb8cac88251a 100644
--- a/fs/lockd/netns.h
+++ b/fs/lockd/netns.h
@@ -15,6 +15,6 @@ struct lockd_net {
 	struct list_head nsm_handles;
 };
 
-extern int lockd_net_id;
+extern unsigned int lockd_net_id;
 
 #endif
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index fc4084ef4736..1c13dd80744f 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -57,7 +57,7 @@ static struct task_struct	*nlmsvc_task;
 static struct svc_rqst		*nlmsvc_rqst;
 unsigned long			nlmsvc_timeout;
 
-int lockd_net_id;
+unsigned int lockd_net_id;
 
 /*
  * These can be set at insmod time (useful for NFS as root filesystem),
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index bf4ec5ecc97e..ce42dd00e4ee 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -2015,7 +2015,7 @@ static void nfsiod_stop(void)
 	destroy_workqueue(wq);
 }
 
-int nfs_net_id;
+unsigned int nfs_net_id;
 EXPORT_SYMBOL_GPL(nfs_net_id);
 
 static int nfs_net_init(struct net *net)
diff --git a/fs/nfs/netns.h b/fs/nfs/netns.h
index fbce0d885d4c..5fbd2bde91ba 100644
--- a/fs/nfs/netns.h
+++ b/fs/nfs/netns.h
@@ -35,6 +35,6 @@ struct nfs_net {
 #endif
 };
 
-extern int nfs_net_id;
+extern unsigned int nfs_net_id;
 
 #endif
diff --git a/fs/nfs_common/grace.c b/fs/nfs_common/grace.c
index fd8c9a5bcac4..420d3a0ab258 100644
--- a/fs/nfs_common/grace.c
+++ b/fs/nfs_common/grace.c
@@ -9,7 +9,7 @@
 #include <net/netns/generic.h>
 #include <linux/fs.h>
 
-static int grace_net_id;
+static unsigned int grace_net_id;
 static DEFINE_SPINLOCK(grace_lock);
 
 /**
diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index ee36efd5aece..3714231a9d0f 100644
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -124,5 +124,5 @@ struct nfsd_net {
 /* Simple check to find out if a given net was properly initialized */
 #define nfsd_netns_ready(nn) ((nn)->sessionid_hashtbl)
 
-extern int nfsd_net_id;
+extern unsigned int nfsd_net_id;
 #endif /* __NFSD_NETNS_H__ */
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 36b2af931e06..2857e46d5cc5 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -1201,7 +1201,7 @@ static int create_proc_exports_entry(void)
 }
 #endif
 
-int nfsd_net_id;
+unsigned int nfsd_net_id;
 
 static __net_init int nfsd_init_net(struct net *net)
 {
diff --git a/include/net/bonding.h b/include/net/bonding.h
index f32f7ef8a23a..3c857778a6ca 100644
--- a/include/net/bonding.h
+++ b/include/net/bonding.h
@@ -681,7 +681,7 @@ static inline int bond_get_targets_ip(__be32 *targets, __be32 ip)
 }
 
 /* exported from bond_main.c */
-extern int bond_net_id;
+extern unsigned int bond_net_id;
 extern const struct bond_parm_tbl bond_lacp_tbl[];
 extern const struct bond_parm_tbl xmit_hashtype_tbl[];
 extern const struct bond_parm_tbl arp_validate_tbl[];
diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h
index 59557c07904b..e893fe43dd13 100644
--- a/include/net/ip_tunnels.h
+++ b/include/net/ip_tunnels.h
@@ -129,7 +129,7 @@ struct ip_tunnel {
 #endif
 	struct ip_tunnel_prl_entry __rcu *prl;	/* potential router list */
 	unsigned int		prl_count;	/* # of entries in PRL */
-	int			ip_tnl_net_id;
+	unsigned int		ip_tnl_net_id;
 	struct gro_cells	gro_cells;
 	bool			collect_md;
 	bool			ignore_df;
@@ -248,7 +248,7 @@ void ip_tunnel_uninit(struct net_device *dev);
 void  ip_tunnel_dellink(struct net_device *dev, struct list_head *head);
 struct net *ip_tunnel_get_link_net(const struct net_device *dev);
 int ip_tunnel_get_iflink(const struct net_device *dev);
-int ip_tunnel_init_net(struct net *net, int ip_tnl_net_id,
+int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id,
 		       struct rtnl_link_ops *ops, char *devname);
 
 void ip_tunnel_delete_net(struct ip_tunnel_net *itn, struct rtnl_link_ops *ops);
@@ -275,7 +275,7 @@ int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
 			 struct ip_tunnel_parm *p);
 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
 		      struct ip_tunnel_parm *p);
-void ip_tunnel_setup(struct net_device *dev, int net_id);
+void ip_tunnel_setup(struct net_device *dev, unsigned int net_id);
 
 struct ip_tunnel_encap_ops {
 	size_t (*encap_hlen)(struct ip_tunnel_encap *e);
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index fc4f757107df..d7149e93a60a 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -291,7 +291,7 @@ struct pernet_operations {
 	int (*init)(struct net *net);
 	void (*exit)(struct net *net);
 	void (*exit_batch)(struct list_head *net_exit_list);
-	int *id;
+	unsigned int *id;
 	size_t size;
 };
 
diff --git a/include/net/netfilter/nf_conntrack_l4proto.h b/include/net/netfilter/nf_conntrack_l4proto.h
index 2152b70626d5..e7b836590f0b 100644
--- a/include/net/netfilter/nf_conntrack_l4proto.h
+++ b/include/net/netfilter/nf_conntrack_l4proto.h
@@ -98,7 +98,7 @@ struct nf_conntrack_l4proto {
 		const struct nla_policy *nla_policy;
 	} ctnl_timeout;
 #endif
-	int	*net_id;
+	unsigned int	*net_id;
 	/* Init l4proto pernet data */
 	int (*init_net)(struct net *net, u_int16_t proto);
 
diff --git a/include/net/netfilter/nf_conntrack_synproxy.h b/include/net/netfilter/nf_conntrack_synproxy.h
index e6937318546c..b0ca402c1f72 100644
--- a/include/net/netfilter/nf_conntrack_synproxy.h
+++ b/include/net/netfilter/nf_conntrack_synproxy.h
@@ -54,7 +54,7 @@ struct synproxy_net {
 	struct synproxy_stats __percpu	*stats;
 };
 
-extern int synproxy_net_id;
+extern unsigned int synproxy_net_id;
 static inline struct synproxy_net *synproxy_pernet(struct net *net)
 {
 	return net_generic(net, synproxy_net_id);
diff --git a/include/net/netns/generic.h b/include/net/netns/generic.h
index 70e158551704..d315786bcfd7 100644
--- a/include/net/netns/generic.h
+++ b/include/net/netns/generic.h
@@ -31,7 +31,7 @@ struct net_generic {
 	void *ptr[0];
 };
 
-static inline void *net_generic(const struct net *net, int id)
+static inline void *net_generic(const struct net *net, unsigned int id)
 {
 	struct net_generic *ng;
 	void *ptr;
diff --git a/kernel/audit.c b/kernel/audit.c
index f1ca11613379..92c463d2d1c7 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -126,7 +126,7 @@ static atomic_t    audit_lost = ATOMIC_INIT(0);
 
 /* The netlink socket. */
 static struct sock *audit_sock;
-static int audit_net_id;
+static unsigned int audit_net_id;
 
 /* Hash for inode-based rules */
 struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index a79365574531..691f0ad7067d 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -44,7 +44,7 @@
 
 /* Global VLAN variables */
 
-int vlan_net_id __read_mostly;
+unsigned int vlan_net_id __read_mostly;
 
 const char vlan_fullname[] = "802.1Q VLAN Support";
 const char vlan_version[] = DRV_VERSION;
diff --git a/net/8021q/vlan.h b/net/8021q/vlan.h
index cc1557978066..df8bd65dd370 100644
--- a/net/8021q/vlan.h
+++ b/net/8021q/vlan.h
@@ -159,7 +159,7 @@ void vlan_netlink_fini(void);
 
 extern struct rtnl_link_ops vlan_link_ops;
 
-extern int vlan_net_id;
+extern unsigned int vlan_net_id;
 
 struct proc_dir_entry;
 
diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c
index 8155bd2a5138..83d937f4415e 100644
--- a/net/bridge/br_netfilter_hooks.c
+++ b/net/bridge/br_netfilter_hooks.c
@@ -46,7 +46,7 @@
 #include <linux/sysctl.h>
 #endif
 
-static int brnf_net_id __read_mostly;
+static unsigned int brnf_net_id __read_mostly;
 
 struct brnf_net {
 	bool enabled;
diff --git a/net/caif/caif_dev.c b/net/caif/caif_dev.c
index d730a0f68f46..2d38b6e34203 100644
--- a/net/caif/caif_dev.c
+++ b/net/caif/caif_dev.c
@@ -52,7 +52,7 @@ struct caif_net {
 	struct caif_device_entry_list caifdevs;
 };
 
-static int caif_net_id;
+static unsigned int caif_net_id;
 static int q_high = 50; /* Percent */
 
 struct cfcnfg *get_cfcnfg(struct net *net)
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 1309d78e2a64..35d37b196e67 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -55,7 +55,7 @@ static struct net_generic *net_alloc_generic(void)
 	return ng;
 }
 
-static int net_assign_generic(struct net *net, int id, void *data)
+static int net_assign_generic(struct net *net, unsigned int id, void *data)
 {
 	struct net_generic *ng, *old_ng;
 
@@ -122,8 +122,7 @@ out:
 static void ops_free(const struct pernet_operations *ops, struct net *net)
 {
 	if (ops->id && ops->size) {
-		int id = *ops->id;
-		kfree(net_generic(net, id));
+		kfree(net_generic(net, *ops->id));
 	}
 }
 
@@ -881,7 +880,7 @@ again:
 			}
 			return error;
 		}
-		max_gen_ptrs = max_t(unsigned int, max_gen_ptrs, *ops->id);
+		max_gen_ptrs = max(max_gen_ptrs, *ops->id);
 	}
 	error = __register_pernet_operations(list, ops);
 	if (error) {
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 306b8f0e03c1..8e6