From 35c7f6de7339f40a591a8aeccacdc429b1953674 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 24 Mar 2009 14:15:22 -0700 Subject: [PATCH] arp_tables: ifname_compare() can assume 16bit alignment Arches without efficient unaligned access can still perform a loop assuming 16bit alignment in ifname_compare() Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/netfilter/arp_tables.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index 64a7c6ce0b98..84b9c179df51 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -76,6 +76,7 @@ static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap, /* * Unfortunatly, _b and _mask are not aligned to an int (or long int) * Some arches dont care, unrolling the loop is a win on them. + * For other arches, we only have a 16bit alignement. */ static unsigned long ifname_compare(const char *_a, const char *_b, const char *_mask) { @@ -95,10 +96,13 @@ static unsigned long ifname_compare(const char *_a, const char *_b, const char * BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long)); #else unsigned long ret = 0; + const u16 *a = (const u16 *)_a; + const u16 *b = (const u16 *)_b; + const u16 *mask = (const u16 *)_mask; int i; - for (i = 0; i < IFNAMSIZ; i++) - ret |= (_a[i] ^ _b[i]) & _mask[i]; + for (i = 0; i < IFNAMSIZ/sizeof(u16); i++) + ret |= (a[i] ^ b[i]) & mask[i]; #endif return ret; } -- 2.20.1