Re: [PATCH] IB/core: replace memcpy with ether_addr_copy
From: Joe Perches
Date: Thu Aug 24 2017 - 13:41:27 EST
On Thu, 2017-08-24 at 23:01 +0530, Himanshu Jha wrote:
> On Thu, Aug 24, 2017 at 09:06:32AM -0700, Joe Perches wrote:
> > On Thu, 2017-08-24 at 21:11 +0530, Himanshu Jha wrote:
> > > Use ether_addr_copy to copy an ethernet address of size ETH_ALEN
> > > instead of memcpy.
> >
> > []
> > diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c
> > []
> > > @@ -798,7 +798,7 @@ int rdma_addr_find_l2_eth_by_grh(const union ib_gid *sgid,
> > > if (ret)
> > > return ret;
> > >
> > > - memcpy(dmac, dev_addr.dst_dev_addr, ETH_ALEN);
> > > + ether_addr_copy(dmac, dev_addr.dst_dev_addr);
> > > dev = dev_get_by_index(&init_net, dev_addr.bound_dev_if);
> > > if (!dev)
> > > return -ENODEV;
> > > @@ -831,7 +831,7 @@ int rdma_addr_find_smac_by_sgid(union ib_gid *sgid, u8 *smac, u16 *vlan_id)
> > > if (ret)
> > > return ret;
> > >
> > > - memcpy(smac, dev_addr.src_dev_addr, ETH_ALEN);
> > > + ether_addr_copy(smac, dev_addr.src_dev_addr);
> > > return ret;
> > > }
> > > EXPORT_SYMBOL(rdma_addr_find_smac_by_sgid);
> >
> > Both dmac and smac are function arguments.
> > What guarantees these to be
> > aligned properly?
> >
>
> Yes, you are correct!
> The arguments should be a pointer to a six byte Ethernet address.
Just for completeness:
The argument should be a pointer to a 6 byte Ethernet address
which is also aligned to an even hardware address.
i.e.: u8 mac_addr[ETH_ALEN] __aligned(2);