ethtool: Fix preserving of wanted feature bits in netlink interface (840110a4) · Commits · 戴 / test

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: ("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>

net/ethtool/features.c

+7 −4

Original line number	Diff line number	Diff line
		@@ -224,7 +224,9 @@ int ethnl_set_features(struct sk_buff skb, struct genl_info info)
		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 skb, struct genl_info info)

		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 skb, struct genl_info info)
		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;
		}

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