From: Maxim Mikityanskiy maximmi@mellanox.com
[ Upstream commit 840110a4eae190dcbb9907d68216d5d1d9f25839 ]
Currently, ethtool-netlink calculates new wanted bits as: (req_wanted & req_mask) | (old_active & ~req_mask)
It completely discards the old wanted bits, so they are forgotten with the next ethtool command. Sample steps to reproduce:
1. ethtool -k eth0 tx-tcp-segmentation: on # TSO is on from the beginning 2. ethtool -K eth0 tx off tx-tcp-segmentation: off [not requested] 3. ethtool -k eth0 tx-tcp-segmentation: off [requested on] 4. ethtool -K eth0 rx off # Some change unrelated to TSO 5. ethtool -k eth0 tx-tcp-segmentation: off # "Wanted on" is forgotten
This commit fixes it by changing the formula to: (req_wanted & req_mask) | (old_wanted & ~req_mask), where old_active was replaced by old_wanted to account for the wanted bits.
The shortcut condition for the case where nothing was changed now compares wanted bitmasks, instead of wanted to active.
Fixes: 0980bfcd6954 ("ethtool: set netdev features with FEATURES_SET request") Signed-off-by: Maxim Mikityanskiy maximmi@mellanox.com Reviewed-by: Michal Kubecek mkubecek@suse.cz Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ethtool/features.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
--- a/net/ethtool/features.c +++ b/net/ethtool/features.c @@ -224,7 +224,9 @@ int ethnl_set_features(struct sk_buff *s DECLARE_BITMAP(wanted_diff_mask, NETDEV_FEATURE_COUNT); DECLARE_BITMAP(active_diff_mask, NETDEV_FEATURE_COUNT); DECLARE_BITMAP(old_active, NETDEV_FEATURE_COUNT); + DECLARE_BITMAP(old_wanted, NETDEV_FEATURE_COUNT); DECLARE_BITMAP(new_active, NETDEV_FEATURE_COUNT); + DECLARE_BITMAP(new_wanted, NETDEV_FEATURE_COUNT); DECLARE_BITMAP(req_wanted, NETDEV_FEATURE_COUNT); DECLARE_BITMAP(req_mask, NETDEV_FEATURE_COUNT); struct nlattr *tb[ETHTOOL_A_FEATURES_MAX + 1]; @@ -250,6 +252,7 @@ int ethnl_set_features(struct sk_buff *s
rtnl_lock(); ethnl_features_to_bitmap(old_active, dev->features); + ethnl_features_to_bitmap(old_wanted, dev->wanted_features); ret = ethnl_parse_bitset(req_wanted, req_mask, NETDEV_FEATURE_COUNT, tb[ETHTOOL_A_FEATURES_WANTED], netdev_features_strings, info->extack); @@ -261,11 +264,11 @@ int ethnl_set_features(struct sk_buff *s goto out_rtnl; }
- /* set req_wanted bits not in req_mask from old_active */ + /* set req_wanted bits not in req_mask from old_wanted */ bitmap_and(req_wanted, req_wanted, req_mask, NETDEV_FEATURE_COUNT); - bitmap_andnot(new_active, old_active, req_mask, NETDEV_FEATURE_COUNT); - bitmap_or(req_wanted, new_active, req_wanted, NETDEV_FEATURE_COUNT); - if (bitmap_equal(req_wanted, old_active, NETDEV_FEATURE_COUNT)) { + bitmap_andnot(new_wanted, old_wanted, req_mask, NETDEV_FEATURE_COUNT); + bitmap_or(req_wanted, new_wanted, req_wanted, NETDEV_FEATURE_COUNT); + if (bitmap_equal(req_wanted, old_wanted, NETDEV_FEATURE_COUNT)) { ret = 0; goto out_rtnl; }