Re: [PATCH net-next 2/3] eth: platform: add a helper for loading netdev->dev_addr

[Michael Walle <michael@walle.cc>]

Am 2021-10-07 15:25, schrieb Jakub Kicinski:
> Commit 406f42fa0d3c ("net-next: When a bond have a massive amount
> of VLANs...") introduced a rbtree for faster Ethernet address look
> up. To maintain netdev->dev_addr in this tree we need to make all
> the writes to it got through appropriate helpers.
> 
> There is a handful of drivers which pass netdev->dev_addr as
> the destination buffer to eth_platform_get_mac_address().
> Add a helper which takes a dev pointer instead, so it can call
> an appropriate helper.
> 
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> ---
..

> +/**
> + * platform_get_ethdev_address - Set netdev's MAC address from a given 
> device
> + * @dev:	Pointer to the device
> + * @netdev:	Pointer to netdev to write the address to
> + *
> + * Wrapper around eth_platform_get_mac_address() which writes the 
> address
> + * directly to netdev->dev_addr.
> + */
> +int platform_get_ethdev_address(struct device *dev, struct net_device 
> *netdev)
> +{
> +	u8 addr[ETH_ALEN];
> +	int ret;
> +
> +	ret = eth_platform_get_mac_address(dev, addr);

this eventually calls ether_addr_copy(), which has a note:
   Please note: dst & src must both be aligned to u16.

Is this true for this addr on the stack?

-michael