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, 12 insertions, 9 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index d5d69ea8f249..e471d037fcc9 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)