net: align static siphash keys

siphash keys use 16 bytes.

Define siphash_aligned_key_t macro so that we can make sure they
are not crossing a cache line boundary.

Signed-off-by: Eric Dumazet <[e-mail]>
Signed-off-by: Jakub Kicinski <[e-mail]>

include/linux/siphash.h

···
 	u64 key[2];
 } siphash_key_t;
 
+#define siphash_aligned_key_t siphash_key_t __aligned(16)
+
 static inline bool siphash_key_is_zero(const siphash_key_t *key)
 {
 	return !(key->key[0] | key->key[1]);

net/core/flow_dissector.c

···
 }
 EXPORT_SYMBOL(__skb_flow_dissect);
 
-static siphash_key_t hashrnd __read_mostly;
+static siphash_aligned_key_t hashrnd;
 static __always_inline void __flow_hash_secret_init(void)
 {
 	net_get_random_once(&hashrnd, sizeof(hashrnd));

net/core/secure_seq.c

···
 #include <linux/in6.h>
 #include <net/tcp.h>
 
-static siphash_key_t net_secret __read_mostly;
-static siphash_key_t ts_secret __read_mostly;
+static siphash_aligned_key_t net_secret;
+static siphash_aligned_key_t ts_secret;
 
 static __always_inline void net_secret_init(void)
 {

net/ipv4/route.c

···
 
 static u32 fnhe_hashfun(__be32 daddr)
 {
-	static siphash_key_t fnhe_hash_key __read_mostly;
+	static siphash_aligned_key_t fnhe_hash_key;
 	u64 hval;
 
 	net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key));

net/ipv4/syncookies.c

···
 #include <net/tcp.h>
 #include <net/route.h>
 
-static siphash_key_t syncookie_secret[2] __read_mostly;
+static siphash_aligned_key_t syncookie_secret[2];
 
 #define COOKIEBITS 24	/* Upper bits store count */
 #define COOKIEMASK (((__u32)1 << COOKIEBITS) - 1)

net/ipv6/route.c

···
 static u32 rt6_exception_hash(const struct in6_addr *dst,
 			      const struct in6_addr *src)
 {
-	static siphash_key_t rt6_exception_key __read_mostly;
+	static siphash_aligned_key_t rt6_exception_key;
 	struct {
 		struct in6_addr dst;
 		struct in6_addr src;

net/ipv6/syncookies.c

···
 #define COOKIEBITS 24	/* Upper bits store count */
 #define COOKIEMASK (((__u32)1 << COOKIEBITS) - 1)
 
-static siphash_key_t syncookie6_secret[2] __read_mostly;
+static siphash_aligned_key_t syncookie6_secret[2];
 
 /* RFC 2460, Section 8.3:
  * [ipv6 tcp] MSS must be computed as the maximum packet size minus 60 [..]

net/netfilter/nf_conntrack_core.c

···
 unsigned int nf_conntrack_max __read_mostly;
 EXPORT_SYMBOL_GPL(nf_conntrack_max);
 seqcount_spinlock_t nf_conntrack_generation __read_mostly;
-static siphash_key_t nf_conntrack_hash_rnd __read_mostly;
+static siphash_aligned_key_t nf_conntrack_hash_rnd;
 
 static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple,
 			      unsigned int zoneid,
···
  */
 u32 nf_ct_get_id(const struct nf_conn *ct)
 {
-	static __read_mostly siphash_key_t ct_id_seed;
+	static siphash_aligned_key_t ct_id_seed;
 	unsigned long a, b, c, d;
 
 	net_get_random_once(&ct_id_seed, sizeof(ct_id_seed));

net/netfilter/nf_conntrack_expect.c

···
 unsigned int nf_ct_expect_max __read_mostly;
 
 static struct kmem_cache *nf_ct_expect_cachep __read_mostly;
-static siphash_key_t nf_ct_expect_hashrnd __read_mostly;
+static siphash_aligned_key_t nf_ct_expect_hashrnd;
 
 /* nf_conntrack_expect helper functions */
 void nf_ct_unlink_expect_report(struct nf_conntrack_expect *exp,

net/netfilter/nf_conntrack_netlink.c

···
 
 static __be32 nf_expect_get_id(const struct nf_conntrack_expect *exp)
 {
-	static __read_mostly siphash_key_t exp_id_seed;
+	static siphash_aligned_key_t exp_id_seed;
 	unsigned long a, b, c, d;
 
 	net_get_random_once(&exp_id_seed, sizeof(exp_id_seed));

net/netfilter/nf_nat_core.c

···
 
 static struct hlist_head *nf_nat_bysource __read_mostly;
 static unsigned int nf_nat_htable_size __read_mostly;
-static siphash_key_t nf_nat_hash_rnd __read_mostly;
+static siphash_aligned_key_t nf_nat_hash_rnd;
 
 struct nf_nat_lookup_hook_priv {
 	struct nf_hook_entries __rcu *entries;