tcp: syncookies: mark cookie_secret read_mostly

only written once.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/syncookies.c

@@ -25,7 +25,7 @@
 
 extern int sysctl_tcp_syncookies;
 
-static u32 syncookie_secret[2][16-4+SHA_DIGEST_WORDS];
+static u32 syncookie_secret[2][16-4+SHA_DIGEST_WORDS] __read_mostly;
 
 #define COOKIEBITS 24	/* Upper bits store count */
 #define COOKIEMASK (((__u32)1 << COOKIEBITS) - 1)

net/ipv6/syncookies.c

@@ -24,7 +24,7 @@
 #define COOKIEBITS 24	/* Upper bits store count */
 #define COOKIEMASK (((__u32)1 << COOKIEBITS) - 1)
 
-static u32 syncookie6_secret[2][16-4+SHA_DIGEST_WORDS];
+static u32 syncookie6_secret[2][16-4+SHA_DIGEST_WORDS] __read_mostly;
 
 /* RFC 2460, Section 8.3:
  * [ipv6 tcp] MSS must be computed as the maximum packet size minus 60 [..]