Re: [PATCH v8 net-next 12/15] net: dsa: netc: add FDB, STP, MTU, port setup and host flooding support

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Stack-allocated byte arrays passed to ether_addr_copy() and ether_addr_equal() may not be 16-bit aligned, risking alignment faults.
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commit eaa86c7415fcd30cddae2cda4bd6d4ca21da6e88
Author: Wei Fang <wei.fang@nxp.com>
Subject: net: dsa: netc: add FDB, STP, MTU, port setup and host flooding support

This commit expands the NETC switch driver with foundational features
including FDB, MDB, STP state handling, MTU configuration, and host
flooding support. The driver currently operates in standalone port mode.

> diff --git a/drivers/net/dsa/netc/netc_main.c b/drivers/net/dsa/netc/netc_main.c
> index 2141b3aa96b7a..9dcaa04d9a65e 100644
> --- a/drivers/net/dsa/netc/netc_main.c
> +++ b/drivers/net/dsa/netc/netc_main.c
[ ... ]
> @@ -367,6 +422,220 @@ static void netc_port_default_config(struct netc_port *np)
[ ... ]
> +static int netc_add_standalone_fdb_bcast_entry(struct netc_switch *priv)
> +{
> +	const u8 bcast[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};

Since stack-allocated byte arrays are only guaranteed to be 1-byte aligned,
could this cause an unaligned access fault on architectures that trap on
strict alignment?

Looking at netc_port_set_fdb_entry(), this pointer is eventually passed to
netc_lookup_fdb_entry() which calls ether_addr_equal(), and to
netc_port_add_fdb_entry() which calls ether_addr_copy(). Both of these
helpers require their arguments to be at least 16-bit aligned.

Should this array be marked with __aligned(2), or could the code use
eth_broadcast_addr() instead?

[ ... ]
> +static int netc_port_add_host_flood_rule(struct netc_port *np,
> +					 bool uc, bool mc)
> +{
> +	const u8 dmac_mask[ETH_ALEN] = {0x1, 0, 0, 0, 0, 0};

Similarly, does this dmac_mask array need explicit 16-bit alignment?

It is passed directly to ether_addr_copy() below, which has the same 16-bit
alignment requirement:

> +	if (uc && !mc)
> +		ether_addr_copy(keye->dmac_mask, dmac_mask);
> +
> +	if (!uc && mc) {
> +		ether_addr_copy(keye->dmac, dmac_mask);
> +		ether_addr_copy(keye->dmac_mask, dmac_mask);
> +	}
[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260518082506.1318236-1-wei.fang@nxp.com?part=12