RDMA/ionic: Use ether_addr_copy instead of memcpy

JIRA: https://issues.redhat.com/browse/RHEL-121486

commit 260cce6
Author: Abhijit Gangurde <abhijit.gangurde@amd.com>
Date:   Fri Sep 19 17:43:01 2025 +0530

    RDMA/ionic: Use ether_addr_copy instead of memcpy

    eth header from ib_ud_header structure packs the mac
    into 4B high and 2B low parts. But when 4B high is used
    in memcpy, it sees it as overflow. However, this is safe
    due to the 4B high and 2B low arrangement in the structure.
    To avoid the memcpy warning, use ether_addr_copy to copy
    the mac address.

    In function ‘fortify_memcpy_chk’,
        inlined from ‘ionic_set_ah_attr.isra’ at drivers/infiniband/hw/ionic/ionic_controlpath.c:609:3:
    ./include/linux/fortify-string.h:580:25: error: call to ‘__read_overflow2_field’ declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Werror=attribute-warning]
      580 |                         __read_overflow2_field(q_size_field, size);
          |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    cc1: all warnings being treated as errors
    make[6]: *** [scripts/Makefile.build:287: drivers/infiniband/hw/ionic/ionic_controlpath.o] Error 1
    make[5]: *** [scripts/Makefile.build:556: drivers/infiniband/hw/ionic] Error 2
    make[5]: *** Waiting for unfinished jobs....
    make[4]: *** [scripts/Makefile.build:556: drivers/infiniband/hw] Error 2
    make[3]: *** [scripts/Makefile.build:556: drivers/infiniband] Error 2
    make[2]: *** [scripts/Makefile.build:556: drivers] Error 2
    make[1]: *** [/tmp/tmp53nb1nwr/Makefile:2011: .] Error 2
    make: *** [Makefile:248: __sub-make] Error 2

    Fixes: e852182 ("RDMA/ionic: Register device ops for control path")
    Reported-by: Leon Romanovsky <leon@kernel.org>
    Closes: https://lore.kernel.org/lkml/20250918180750.GA135135@unreal/
    Signed-off-by: Abhijit Gangurde <abhijit.gangurde@amd.com>
    Link: https://patch.msgid.link/20250919121301.1113759-2-abhijit.gangurde@amd.com
    Signed-off-by: Leon Romanovsky <leon@kernel.org>

Signed-off-by: Jakub Ramaseuski <jramaseu@redhat.com>

Author: Jakub Ramaseuski

drivers/infiniband/hw/ionic/ionic_controlpath.c

@@ -606,7 +606,7 @@ static void ionic_set_ah_attr(struct ionic_ibdev *dev,
 	memset(ah_attr, 0, sizeof(*ah_attr));
 	ah_attr->type = RDMA_AH_ATTR_TYPE_ROCE;
 	if (hdr->eth_present)
-		memcpy(&ah_attr->roce.dmac, &hdr->eth.dmac_h, ETH_ALEN);
+		ether_addr_copy(ah_attr->roce.dmac, hdr->eth.dmac_h);
 	rdma_ah_set_sl(ah_attr, vlan >> VLAN_PRIO_SHIFT);
 	rdma_ah_set_port_num(ah_attr, 1);
 	rdma_ah_set_grh(ah_attr, NULL, flow_label, sgid_index, ttl, tos);