percpu: add __percpu sparse annotations to net

Add __percpu sparse annotations to net.

These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors.  This patch doesn't affect normal builds.

The macro and type tricks around snmp stats make things a bit
interesting.  DEFINE/DECLARE_SNMP_STAT() macros mark the target field
as __percpu and SNMP_UPD_PO_STATS() macro is updated accordingly.  All
snmp_mib_*() users which used to cast the argument to (void **) are
updated to cast it to (void __percpu **).

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Vlad Yasevich <vladislav.yasevich@hp.com>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 50 insertions, 47 deletions

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 7d12c6a9b19..33b7dffa773 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1385,7 +1385,7 @@ int inet_ctl_sock_create(struct sock **sk, unsigned short family,
 }
 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
 
-unsigned long snmp_fold_field(void *mib[], int offt)
+unsigned long snmp_fold_field(void __percpu *mib[], int offt)
 {
 	unsigned long res = 0;
 	int i;
@@ -1398,7 +1398,7 @@ unsigned long snmp_fold_field(void *mib[], int offt)
 }
 EXPORT_SYMBOL_GPL(snmp_fold_field);
 
-int snmp_mib_init(void *ptr[2], size_t mibsize)
+int snmp_mib_init(void __percpu *ptr[2], size_t mibsize)
 {
 	BUG_ON(ptr == NULL);
 	ptr[0] = __alloc_percpu(mibsize, __alignof__(unsigned long long));
@@ -1416,7 +1416,7 @@ err0:
 }
 EXPORT_SYMBOL_GPL(snmp_mib_init);
 
-void snmp_mib_free(void *ptr[2])
+void snmp_mib_free(void __percpu *ptr[2])
 {
 	BUG_ON(ptr == NULL);
 	free_percpu(ptr[0]);
@@ -1460,25 +1460,25 @@ static const struct net_protocol icmp_protocol = {
 
 static __net_init int ipv4_mib_init_net(struct net *net)
 {
-	if (snmp_mib_init((void **)net->mib.tcp_statistics,
+	if (snmp_mib_init((void __percpu **)net->mib.tcp_statistics,
 			  sizeof(struct tcp_mib)) < 0)
 		goto err_tcp_mib;
-	if (snmp_mib_init((void **)net->mib.ip_statistics,
+	if (snmp_mib_init((void __percpu **)net->mib.ip_statistics,
 			  sizeof(struct ipstats_mib)) < 0)
 		goto err_ip_mib;
-	if (snmp_mib_init((void **)net->mib.net_statistics,
+	if (snmp_mib_init((void __percpu **)net->mib.net_statistics,
 			  sizeof(struct linux_mib)) < 0)
 		goto err_net_mib;
-	if (snmp_mib_init((void **)net->mib.udp_statistics,
+	if (snmp_mib_init((void __percpu **)net->mib.udp_statistics,
 			  sizeof(struct udp_mib)) < 0)
 		goto err_udp_mib;
-	if (snmp_mib_init((void **)net->mib.udplite_statistics,
+	if (snmp_mib_init((void __percpu **)net->mib.udplite_statistics,
 			  sizeof(struct udp_mib)) < 0)
 		goto err_udplite_mib;
-	if (snmp_mib_init((void **)net->mib.icmp_statistics,
+	if (snmp_mib_init((void __percpu **)net->mib.icmp_statistics,
 			  sizeof(struct icmp_mib)) < 0)
 		goto err_icmp_mib;
-	if (snmp_mib_init((void **)net->mib.icmpmsg_statistics,
+	if (snmp_mib_init((void __percpu **)net->mib.icmpmsg_statistics,
 			  sizeof(struct icmpmsg_mib)) < 0)
 		goto err_icmpmsg_mib;
 
@@ -1486,30 +1486,30 @@ static __net_init int ipv4_mib_init_net(struct net *net)
 	return 0;
 
 err_icmpmsg_mib:
-	snmp_mib_free((void **)net->mib.icmp_statistics);
+	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
 err_icmp_mib:
-	snmp_mib_free((void **)net->mib.udplite_statistics);
+	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
 err_udplite_mib:
-	snmp_mib_free((void **)net->mib.udp_statistics);
+	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
 err_udp_mib:
-	snmp_mib_free((void **)net->mib.net_statistics);
+	snmp_mib_free((void __percpu **)net->mib.net_statistics);
 err_net_mib:
-	snmp_mib_free((void **)net->mib.ip_statistics);
+	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
 err_ip_mib:
-	snmp_mib_free((void **)net->mib.tcp_statistics);
+	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
 err_tcp_mib:
 	return -ENOMEM;
 }
 
 static __net_exit void ipv4_mib_exit_net(struct net *net)
 {
-	snmp_mib_free((void **)net->mib.icmpmsg_statistics);
-	snmp_mib_free((void **)net->mib.icmp_statistics);
-	snmp_mib_free((void **)net->mib.udplite_statistics);
-	snmp_mib_free((void **)net->mib.udp_statistics);
-	snmp_mib_free((void **)net->mib.net_statistics);
-	snmp_mib_free((void **)net->mib.ip_statistics);
-	snmp_mib_free((void **)net->mib.tcp_statistics);
+	snmp_mib_free((void __percpu **)net->mib.icmpmsg_statistics);
+	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
+	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
+	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
+	snmp_mib_free((void __percpu **)net->mib.net_statistics);
+	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
+	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
 }
 
 static __net_initdata struct pernet_operations ipv4_mib_ops = {
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 1b09a6dde7c..242ed230737 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -280,7 +280,7 @@ static void icmpmsg_put(struct seq_file *seq)
 
 	count = 0;
 	for (i = 0; i < ICMPMSG_MIB_MAX; i++) {
-		val = snmp_fold_field((void **) net->mib.icmpmsg_statistics, i);
+		val = snmp_fold_field((void __percpu **) net->mib.icmpmsg_statistics, i);
 		if (val) {
 			type[count] = i;
 			vals[count++] = val;
@@ -307,18 +307,18 @@ static void icmp_put(struct seq_file *seq)
 	for (i=0; icmpmibmap[i].name != NULL; i++)
 		seq_printf(seq, " Out%s", icmpmibmap[i].name);
 	seq_printf(seq, "\nIcmp: %lu %lu",
-		snmp_fold_field((void **) net->mib.icmp_statistics, ICMP_MIB_INMSGS),
-		snmp_fold_field((void **) net->mib.icmp_statistics, ICMP_MIB_INERRORS));
+		snmp_fold_field((void __percpu **) net->mib.icmp_statistics, ICMP_MIB_INMSGS),
+		snmp_fold_field((void __percpu **) net->mib.icmp_statistics, ICMP_MIB_INERRORS));
 	for (i=0; icmpmibmap[i].name != NULL; i++)
 		seq_printf(seq, " %lu",
-			snmp_fold_field((void **) net->mib.icmpmsg_statistics,
+			snmp_fold_field((void __percpu **) net->mib.icmpmsg_statistics,
 				icmpmibmap[i].index));
 	seq_printf(seq, " %lu %lu",
-		snmp_fold_field((void **) net->mib.icmp_statistics, ICMP_MIB_OUTMSGS),
-		snmp_fold_field((void **) net->mib.icmp_statistics, ICMP_MIB_OUTERRORS));
+		snmp_fold_field((void __percpu **) net->mib.icmp_statistics, ICMP_MIB_OUTMSGS),
+		snmp_fold_field((void __percpu **) net->mib.icmp_statistics, ICMP_MIB_OUTERRORS));
 	for (i=0; icmpmibmap[i].name != NULL; i++)
 		seq_printf(seq, " %lu",
-			snmp_fold_field((void **) net->mib.icmpmsg_statistics,
+			snmp_fold_field((void __percpu **) net->mib.icmpmsg_statistics,
 				icmpmibmap[i].index | 0x100));
 }
 
@@ -341,7 +341,7 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
 
 	for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
 		seq_printf(seq, " %lu",
-			   snmp_fold_field((void **)net->mib.ip_statistics,
+			   snmp_fold_field((void __percpu **)net->mib.ip_statistics,
 					   snmp4_ipstats_list[i].entry));
 
 	icmp_put(seq);	/* RFC 2011 compatibility */
@@ -356,11 +356,11 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
 		/* MaxConn field is signed, RFC 2012 */
 		if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN)
 			seq_printf(seq, " %ld",
-				   snmp_fold_field((void **)net->mib.tcp_statistics,
+				   snmp_fold_field((void __percpu **)net->mib.tcp_statistics,
 						   snmp4_tcp_list[i].entry));
 		else
 			seq_printf(seq, " %lu",
-				   snmp_fold_field((void **)net->mib.tcp_statistics,
+				   snmp_fold_field((void __percpu **)net->mib.tcp_statistics,
 						   snmp4_tcp_list[i].entry));
 	}
 
@@ -371,7 +371,7 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
 	seq_puts(seq, "\nUdp:");
 	for (i = 0; snmp4_udp_list[i].name != NULL; i++)
 		seq_printf(seq, " %lu",
-			   snmp_fold_field((void **)net->mib.udp_statistics,
+			   snmp_fold_field((void __percpu **)net->mib.udp_statistics,
 					   snmp4_udp_list[i].entry));
 
 	/* the UDP and UDP-Lite MIBs are the same */
@@ -382,7 +382,7 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
 	seq_puts(seq, "\nUdpLite:");
 	for (i = 0; snmp4_udp_list[i].name != NULL; i++)
 		seq_printf(seq, " %lu",
-			   snmp_fold_field((void **)net->mib.udplite_statistics,
+			   snmp_fold_field((void __percpu **)net->mib.udplite_statistics,
 					   snmp4_udp_list[i].entry));
 
 	seq_putc(seq, '\n');
@@ -419,7 +419,7 @@ static int netstat_seq_show(struct seq_file *seq, void *v)
 	seq_puts(seq, "\nTcpExt:");
 	for (i = 0; snmp4_net_list[i].name != NULL; i++)
 		seq_printf(seq, " %lu",
-			   snmp_fold_field((void **)net->mib.net_statistics,
+			   snmp_fold_field((void __percpu **)net->mib.net_statistics,
 					   snmp4_net_list[i].entry));
 
 	seq_puts(seq, "\nIpExt:");
@@ -429,7 +429,7 @@ static int netstat_seq_show(struct seq_file *seq, void *v)
 	seq_puts(seq, "\nIpExt:");
 	for (i = 0; snmp4_ipextstats_list[i].name != NULL; i++)
 		seq_printf(seq, " %lu",
-			   snmp_fold_field((void **)net->mib.ip_statistics,
+			   snmp_fold_field((void __percpu **)net->mib.ip_statistics,
 					   snmp4_ipextstats_list[i].entry));
 
 	seq_putc(seq, '\n');
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index b16dfadbe6d..04762d3bef7 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -3334,7 +3334,7 @@ static __net_initdata struct pernet_operations rt_secret_timer_ops = {
 
 
 #ifdef CONFIG_NET_CLS_ROUTE
-struct ip_rt_acct *ip_rt_acct __read_mostly;
+struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
 #endif /* CONFIG_NET_CLS_ROUTE */
 
 static __initdata unsigned long rhash_entries;
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index d5d69ea8f24..e471d037fcc 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2788,10 +2788,10 @@ EXPORT_SYMBOL(tcp_gro_complete);
 
 #ifdef CONFIG_TCP_MD5SIG
 static unsigned long tcp_md5sig_users;
-static struct tcp_md5sig_pool **tcp_md5sig_pool;
+static struct tcp_md5sig_pool * __percpu *tcp_md5sig_pool;
 static DEFINE_SPINLOCK(tcp_md5sig_pool_lock);
 
-static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool **pool)
+static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool * __percpu *pool)
 {
 	int cpu;
 	for_each_possible_cpu(cpu) {
@@ -2808,7 +2808,7 @@ static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool **pool)
 
 void tcp_free_md5sig_pool(void)
 {
-	struct tcp_md5sig_pool **pool = NULL;
+	struct tcp_md5sig_pool * __percpu *pool = NULL;
 
 	spin_lock_bh(&tcp_md5sig_pool_lock);
 	if (--tcp_md5sig_users == 0) {
@@ -2822,10 +2822,11 @@ void tcp_free_md5sig_pool(void)
 
 EXPORT_SYMBOL(tcp_free_md5sig_pool);
 
-static struct tcp_md5sig_pool **__tcp_alloc_md5sig_pool(struct sock *sk)
+static struct tcp_md5sig_pool * __percpu *
+__tcp_alloc_md5sig_pool(struct sock *sk)
 {
 	int cpu;
-	struct tcp_md5sig_pool **pool;
+	struct tcp_md5sig_pool * __percpu *pool;
 
 	pool = alloc_percpu(struct tcp_md5sig_pool *);
 	if (!pool)
@@ -2852,9 +2853,9 @@ out_free:
 	return NULL;
 }
 
-struct tcp_md5sig_pool **tcp_alloc_md5sig_pool(struct sock *sk)
+struct tcp_md5sig_pool * __percpu *tcp_alloc_md5sig_pool(struct sock *sk)
 {
-	struct tcp_md5sig_pool **pool;
+	struct tcp_md5sig_pool * __percpu *pool;
 	int alloc = 0;
 
 retry:
@@ -2873,7 +2874,9 @@ retry:
 
 	if (alloc) {
 		/* we cannot hold spinlock here because this may sleep. */
-		struct tcp_md5sig_pool **p = __tcp_alloc_md5sig_pool(sk);
+		struct tcp_md5sig_pool * __percpu *p;
+
+		p = __tcp_alloc_md5sig_pool(sk);
 		spin_lock_bh(&tcp_md5sig_pool_lock);
 		if (!p) {
 			tcp_md5sig_users--;
@@ -2897,7 +2900,7 @@ EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
 
 struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu)
 {
-	struct tcp_md5sig_pool **p;
+	struct tcp_md5sig_pool * __percpu *p;
 	spin_lock_bh(&tcp_md5sig_pool_lock);
 	p = tcp_md5sig_pool;
 	if (p)