From 9d0a58fb9747afd27d490c02a97889a1b59f6be4 Mon Sep 17 00:00:00 2001 From: Vasily Gorbik Date: Fri, 29 Jun 2018 19:45:52 +0200 Subject: s390/qeth: avoid using is_multicast_ether_addr_64bits on (u8 *)[6] *ether_addr*_64bits functions have been introduced to optimize performance critical paths, which access 6-byte ethernet address as u64 value to get "nice" assembly. A harmless hack works nicely on ethernet addresses shoved into a structure or a larger buffer, until busted by Kasan on smth like plain (u8 *)[6]. qeth_l2_set_mac_address calls qeth_l2_remove_mac passing u8 old_addr[ETH_ALEN] as an argument. Adding/removing macs for an ethernet adapter is not that performance critical. Moreover is_multicast_ether_addr_64bits itself on s390 is not faster than is_multicast_ether_addr: is_multicast_ether_addr(%r2) -> %r2 llc %r2,0(%r2) risbg %r2,%r2,63,191,0 is_multicast_ether_addr_64bits(%r2) -> %r2 llgc %r2,0(%r2) risbg %r2,%r2,63,191,0 So, let's just use is_multicast_ether_addr instead of is_multicast_ether_addr_64bits. Fixes: bcacfcbc82b4 ("s390/qeth: fix MAC address update sequence") Reviewed-by: Julian Wiedmann Signed-off-by: Vasily Gorbik Signed-off-by: Julian Wiedmann Signed-off-by: David S. Miller --- drivers/s390/net/qeth_l2_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c index 7daf125dae76..5464515b71f1 100644 --- a/drivers/s390/net/qeth_l2_main.c +++ b/drivers/s390/net/qeth_l2_main.c @@ -140,7 +140,7 @@ static int qeth_l2_send_setmac(struct qeth_card *card, __u8 *mac) static int qeth_l2_write_mac(struct qeth_card *card, u8 *mac) { - enum qeth_ipa_cmds cmd = is_multicast_ether_addr_64bits(mac) ? + enum qeth_ipa_cmds cmd = is_multicast_ether_addr(mac) ? IPA_CMD_SETGMAC : IPA_CMD_SETVMAC; int rc; @@ -157,7 +157,7 @@ static int qeth_l2_write_mac(struct qeth_card *card, u8 *mac) static int qeth_l2_remove_mac(struct qeth_card *card, u8 *mac) { - enum qeth_ipa_cmds cmd = is_multicast_ether_addr_64bits(mac) ? + enum qeth_ipa_cmds cmd = is_multicast_ether_addr(mac) ? IPA_CMD_DELGMAC : IPA_CMD_DELVMAC; int rc; -- cgit v1.2.3