[IPV6] SNMP: Use put_unaligned() instead of memcpy().

Hint from David Miller <davem@davemloft.net>.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ipv6.h

@@ -172,7 +172,7 @@ int snmp6_alloc_dev(struct inet6_dev *idev);
 int snmp6_free_dev(struct inet6_dev *idev);
 int snmp6_mib_init(void *ptr[2], size_t mibsize, size_t mibalign);
 void snmp6_mib_free(void *ptr[2]);
-void snmp6_fill_stats(void *stats, struct inet6_dev *idev, int attrtype, int bytes);
+void snmp6_fill_stats(u64 *stats, struct inet6_dev *idev, int attrtype, int bytes);
 
 struct ip6_ra_chain
 {

net/ipv6/proc.c

@@ -23,6 +23,7 @@
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/stddef.h>
+#include <asm/unaligned.h>
 #include <net/sock.h>
 #include <net/tcp.h>
 #include <net/transp_v6.h>
@@ -210,30 +211,23 @@ static const struct file_operations snmp6_seq_fops = {
 };
 #endif	/* CONFIG_PROC_FS */
 
-/*
- * Stats may not be aligned for u64, so use memcpy to avoid
- * unaligned accesses.
- */
-static inline void __set_u64(void *p, u64 v)
-{
-	memcpy(p, &v, sizeof(u64));
-}
-
 static inline void
-__snmp6_fill_stats(void *stats, void **mib, int items, int bytes)
+__snmp6_fill_stats(u64 *stats, void **mib, int items, int bytes)
 {
 	int i;
-	u8 *p = stats;
 	int pad = bytes - sizeof(u64) * items;
 	BUG_ON(pad < 0);
-	__set_u64(p, items);
-	for (i = 1, p += sizeof(u64); i < items; i++, p += sizeof(u64))
-		__set_u64(p, fold_field(mib, i));
-	memset(p, 0, pad);
+
+	/* Use put_unaligned() because stats may not be aligned for u64. */
+	put_unaligned(items, &stats[0]);
+	for (i = 1; i < items; i++)
+		put_unaligned(fold_field(mib, i), &stats[i]);
+
+	memset(&stats[items], 0, pad);
 }
 
 void
-snmp6_fill_stats(void *stats, struct inet6_dev *idev, int attrtype, int bytes)
+snmp6_fill_stats(u64 *stats, struct inet6_dev *idev, int attrtype, int bytes)
 {
 	switch(attrtype) {
 	case IFLA_INET6_STATS: