ethtool: fix the state of additional contexts with old API

We expect drivers implementing the new create/modify/destroy
API to populate the defaults in struct ethtool_rxfh_context.
In legacy API ctx isn't even passed, and rxfh.indir / rxfh.key
are NULL so drivers can't give us defaults even if they want to.
Call get_rxfh() to fetch the values. We can reuse rxfh_dev
for the get_rxfh(), rxfh stores the input from the user.

This fixes IOCTL reporting 0s instead of the default key /
indir table for drivers using legacy API.

Add a check to try to catch drivers using the new API
but not populating the key.

Fixes: 7964e7884643 ("net: ethtool: use the tracking array for get_rxfh on custom RSS contexts")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Edward Cree <ecree.xilinx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index a37ba113610a81fa181503e4c05436e21239a6aa..8ca13208d240f297e59edea30b4cde8f0786d0d4 100644 (file)
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1382,10 +1382,9 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
             rxfh.input_xfrm == RXH_XFRM_NO_CHANGE))
                return -EINVAL;
 
-       if (rxfh.indir_size != ETH_RXFH_INDIR_NO_CHANGE)
-               indir_bytes = dev_indir_size * sizeof(rxfh_dev.indir[0]);
+       indir_bytes = dev_indir_size * sizeof(rxfh_dev.indir[0]);
 
-       rss_config = kzalloc(indir_bytes + rxfh.key_size, GFP_USER);
+       rss_config = kzalloc(indir_bytes + dev_key_size, GFP_USER);
        if (!rss_config)
                return -ENOMEM;
 
@@ -1475,16 +1474,21 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
        rxfh_dev.input_xfrm = rxfh.input_xfrm;
 
        if (rxfh.rss_context && ops->create_rxfh_context) {
-               if (create)
+               if (create) {
                        ret = ops->create_rxfh_context(dev, ctx, &rxfh_dev,
                                                       extack);
-               else if (rxfh_dev.rss_delete)
+                       /* Make sure driver populates defaults */
+                       WARN_ON_ONCE(!ret && !rxfh_dev.key &&
+                                    !memchr_inv(ethtool_rxfh_context_key(ctx),
+                                                0, ctx->key_size));
+               } else if (rxfh_dev.rss_delete) {
                        ret = ops->remove_rxfh_context(dev, ctx,
                                                       rxfh.rss_context,
                                                       extack);
-               else
+               } else {
                        ret = ops->modify_rxfh_context(dev, ctx, &rxfh_dev,
                                                       extack);
+               }
        } else {
                ret = ops->set_rxfh(dev, &rxfh_dev, extack);
        }
@@ -1523,6 +1527,22 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
                        kfree(ctx);
                        goto out;
                }
+
+               /* Fetch the defaults for the old API, in the new API drivers
+                * should write defaults into ctx themselves.
+                */
+               rxfh_dev.indir = (u32 *)rss_config;
+               rxfh_dev.indir_size = dev_indir_size;
+
+               rxfh_dev.key = rss_config + indir_bytes;
+               rxfh_dev.key_size = dev_key_size;
+
+               ret = ops->get_rxfh(dev, &rxfh_dev);
+               if (WARN_ON(ret)) {
+                       xa_erase(&dev->ethtool->rss_ctx, rxfh.rss_context);
+                       kfree(ctx);
+                       goto out;
+               }
        }
        if (rxfh_dev.rss_delete) {
                WARN_ON(xa_erase(&dev->ethtool->rss_ctx, rxfh.rss_context) != ctx);
@@ -1531,12 +1551,14 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
                if (rxfh_dev.indir) {
                        for (i = 0; i < dev_indir_size; i++)
                                ethtool_rxfh_context_indir(ctx)[i] = rxfh_dev.indir[i];
-                       ctx->indir_configured = 1;
+                       ctx->indir_configured =
+                               rxfh.indir_size &&
+                               rxfh.indir_size != ETH_RXFH_INDIR_NO_CHANGE;
                }
                if (rxfh_dev.key) {
                        memcpy(ethtool_rxfh_context_key(ctx), rxfh_dev.key,
                               dev_key_size);
-                       ctx->key_configured = 1;
+                       ctx->key_configured = !!rxfh.key_size;
                }
                if (rxfh_dev.hfunc != ETH_RSS_HASH_NO_CHANGE)
                        ctx->hfunc = rxfh_dev.hfunc;