From 1eb2cded45b35816085c1f962933c187d970f9dc Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 6 May 2024 10:28:12 +0000 Subject: net: annotate writes on dev->mtu from ndo_change_mtu() Simon reported that ndo_change_mtu() methods were never updated to use WRITE_ONCE(dev->mtu, new_mtu) as hinted in commit 501a90c94510 ("inet: protect against too small mtu values.") We read dev->mtu without holding RTNL in many places, with READ_ONCE() annotations. It is time to take care of ndo_change_mtu() methods to use corresponding WRITE_ONCE() Signed-off-by: Eric Dumazet Reported-by: Simon Horman Closes: https://lore.kernel.org/netdev/20240505144608.GB67882@kernel.org/ Reviewed-by: Jacob Keller Reviewed-by: Sabrina Dubroca Reviewed-by: Simon Horman Acked-by: Shannon Nelson Link: https://lore.kernel.org/r/20240506102812.3025432-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 2 +- drivers/net/ethernet/netronome/nfp/nfp_net_repr.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/net/ethernet/netronome') diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c index 997cc4fcffdb..182ba0a8b095 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c @@ -1526,7 +1526,7 @@ static void nfp_net_dp_swap(struct nfp_net *nn, struct nfp_net_dp *dp) *dp = nn->dp; nn->dp = new_dp; - nn->dp.netdev->mtu = new_dp.mtu; + WRITE_ONCE(nn->dp.netdev->mtu, new_dp.mtu); if (!netif_is_rxfh_configured(nn->dp.netdev)) nfp_net_rss_init_itbl(nn); diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_repr.c b/drivers/net/ethernet/netronome/nfp/nfp_net_repr.c index 3af1229a3f08..eee0bfc41074 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_net_repr.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_repr.c @@ -177,7 +177,7 @@ static int nfp_repr_change_mtu(struct net_device *netdev, int new_mtu) if (err) return err; - netdev->mtu = new_mtu; + WRITE_ONCE(netdev->mtu, new_mtu); return 0; } -- cgit v1.2.3