ethtool: prepare for larger netdev_features_t type

v2:	changed loop in ethtool_set_features() per Ben's suggestion

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 26 insertions, 16 deletions

diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 817ad4b2b9db..bbf84fe0096e 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -38,7 +38,7 @@ EXPORT_SYMBOL(ethtool_op_get_link);
 
 /* Handlers for each ethtool command */
 
-#define ETHTOOL_DEV_FEATURE_WORDS       1
+#define ETHTOOL_DEV_FEATURE_WORDS       ((NETDEV_FEATURE_COUNT + 31) / 32)
 
 static const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN] = {
         [NETIF_F_SG_BIT] =               "tx-scatter-gather",
@@ -82,16 +82,20 @@ static int ethtool_get_features(struct net_device *dev, void __user *useraddr)
                 .cmd = ETHTOOL_GFEATURES,
                 .size = ETHTOOL_DEV_FEATURE_WORDS,
         };
-        struct ethtool_get_features_block features[ETHTOOL_DEV_FEATURE_WORDS] = {
-                {
-                        .available = dev->hw_features,
-                        .requested = dev->wanted_features,
-                        .active = dev->features,
-                        .never_changed = NETIF_F_NEVER_CHANGE,
-                },
-        };
+        struct ethtool_get_features_block features[ETHTOOL_DEV_FEATURE_WORDS];
         u32 __user *sizeaddr;
         u32 copy_size;
+        int i;
+
+        /* in case feature bits run out again */
+        BUILD_BUG_ON(ETHTOOL_DEV_FEATURE_WORDS*sizeof(u32) > sizeof(netdev_features_t));
+
+        for (i = 0; i < ETHTOOL_DEV_FEATURE_WORDS; ++i) {
+                features[i].available = (u32)(dev->hw_features >> (32*i));
+                features[i].requested = (u32)(dev->wanted_features >> (32*i));
+                features[i].active = (u32)(dev->features >> (32*i));
+                features[i].never_changed = (u32)(NETIF_F_NEVER_CHANGE >> (32*i));
+        }
 
         sizeaddr = useraddr + offsetof(struct ethtool_gfeatures, size);
         if (get_user(copy_size, sizeaddr))
@@ -113,7 +117,8 @@ static int ethtool_set_features(struct net_device *dev, void __user *useraddr)
 {
         struct ethtool_sfeatures cmd;
         struct ethtool_set_features_block features[ETHTOOL_DEV_FEATURE_WORDS];
-        int ret = 0;
+        netdev_features_t wanted = 0, valid = 0;
+        int i, ret = 0;
 
         if (copy_from_user(&cmd, useraddr, sizeof(cmd)))
                 return -EFAULT;
@@ -125,19 +130,24 @@ static int ethtool_set_features(struct net_device *dev, void __user *useraddr)
         if (copy_from_user(features, useraddr, sizeof(features)))
                 return -EFAULT;
 
-        if (features[0].valid & ~NETIF_F_ETHTOOL_BITS)
+        for (i = 0; i < ETHTOOL_DEV_FEATURE_WORDS; ++i) {
+                valid |= (netdev_features_t)features[i].valid << (32*i);
+                wanted |= (netdev_features_t)features[i].requested << (32*i);
+        }
+
+        if (valid & ~NETIF_F_ETHTOOL_BITS)
                 return -EINVAL;
 
-        if (features[0].valid & ~dev->hw_features) {
-                features[0].valid &= dev->hw_features;
+        if (valid & ~dev->hw_features) {
+                valid &= dev->hw_features;
                 ret |= ETHTOOL_F_UNSUPPORTED;
         }
 
-        dev->wanted_features &= ~features[0].valid;
-        dev->wanted_features |= features[0].valid & features[0].requested;
+        dev->wanted_features &= ~valid;
+        dev->wanted_features |= wanted & valid;
         __netdev_update_features(dev);
 
-        if ((dev->wanted_features ^ dev->features) & features[0].valid)
+        if ((dev->wanted_features ^ dev->features) & valid)
                 ret |= ETHTOOL_F_WISH;
 
         return ret;