2017-08-24 15:42:11

by Himanshu Jha

Subject: [PATCH] IB/core: replace memcpy with ether_addr_copy

Use ether_addr_copy to copy an ethernet address of size ETH_ALEN
instead of memcpy.

Signed-off-by: Himanshu Jha <[email protected]>
---
drivers/infiniband/core/addr.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c
index 437522c..fc5bf11 100644
--- 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);
--
2.7.4

2017-08-24 16:06:55

by Joe Perches

Subject: Re: [PATCH] IB/core: replace memcpy with ether_addr_copy

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?

2017-08-24 17:31:15

by Himanshu Jha

Subject: Re: [PATCH] IB/core: replace memcpy with ether_addr_copy

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.

Apologies!

2017-08-24 17:41:21

by Joe Perches

Subject: Re: [PATCH] IB/core: replace memcpy with ether_addr_copy

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);