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>

1 files changed, 3 insertions, 2 deletions

diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 85ec1cb7fd41..0ef7061920c0 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -1005,12 +1005,13 @@ EXPORT_SYMBOL_GPL(dccp_shutdown);
 
 static inline int dccp_mib_init(void)
 {
-	return snmp_mib_init((void**)dccp_statistics, sizeof(struct dccp_mib));
+	return snmp_mib_init((void __percpu **)dccp_statistics,
+			     sizeof(struct dccp_mib));
 }
 
 static inline void dccp_mib_exit(void)
 {
-	snmp_mib_free((void**)dccp_statistics);
+	snmp_mib_free((void __percpu **)dccp_statistics);
 }
 
 static int thash_entries;