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| author | Maxim Mikityanskiy <maximmi@mellanox.com> | 2020-08-17 16:34:05 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-08-18 16:00:24 -0700 |
| commit | 840110a4eae190dcbb9907d68216d5d1d9f25839 (patch) | |
| tree | bc982c301db02b4a1d8c53c0013d73a4218ec4e1 /net | |
| parent | 4ef1a7cb08e94da1f2f2a34ee6cefe7ae142dc98 (diff) | |
| download | lwn-840110a4eae190dcbb9907d68216d5d1d9f25839.tar.gz lwn-840110a4eae190dcbb9907d68216d5d1d9f25839.zip | |
ethtool: Fix preserving of wanted feature bits in netlink interface
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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ethtool/features.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/net/ethtool/features.c b/net/ethtool/features.c index 4e632dc987d8..ec196f0fddc9 100644 --- a/net/ethtool/features.c +++ b/net/ethtool/features.c @@ -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; } |