4.17-stable review patch. If anyone has any objections, please let me know.
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From: Vasily Gorbik gor@linux.ibm.com
[ Upstream commit 9d0a58fb9747afd27d490c02a97889a1b59f6be4 ]
*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 jwi@linux.ibm.com Signed-off-by: Vasily Gorbik gor@linux.ibm.com Signed-off-by: Julian Wiedmann jwi@linux.ibm.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/s390/net/qeth_l2_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/s390/net/qeth_l2_main.c +++ b/drivers/s390/net/qeth_l2_main.c @@ -141,7 +141,7 @@ static int qeth_l2_send_setmac(struct qe
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;
@@ -158,7 +158,7 @@ static int qeth_l2_write_mac(struct qeth
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;