[PATCH AUTOSEL 6.8 65/68] netdev: let netlink core handle -EMSGSIZE errors

Sasha Levin
2024-03-29T12:29:14Z

From: Jakub Kicinski <kuba@kernel.org>

[ Upstream commit 0b11b1c5c320555483e8a94c44549db24c289987 ]

Previous change added -EMSGSIZE handling to af_netlink, we don't
have to hide these errors any longer.

Theoretically the error handling changes from:
if (err == -EMSGSIZE)
to
if (err == -EMSGSIZE && skb->len)

everywhere, but in practice it doesn't matter.
All messages fit into NLMSG_GOODSIZE, so overflow of an empty
skb cannot happen.

Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/core/netdev-genl.c | 15 +++------------
net/core/page_pool_user.c | 2 --
2 files changed, 3 insertions(+), 14 deletions(-)

diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index fd98936da3aec..918b109e0cf40 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -152,10 +152,7 @@ int netdev_nl_dev_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
}
rtnl_unlock();

- if (err != -EMSGSIZE)
- return err;
-
- return skb->len;
+ return err;
}

static int
@@ -287,10 +284,7 @@ int netdev_nl_napi_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
}
rtnl_unlock();

- if (err != -EMSGSIZE)
- return err;
-
- return skb->len;
+ return err;
}

static int
@@ -463,10 +457,7 @@ int netdev_nl_queue_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
}
rtnl_unlock();

- if (err != -EMSGSIZE)
- return err;
-
- return skb->len;
+ return err;
}

static int netdev_genl_netdevice_event(struct notifier_block *nb,
diff --git a/net/core/page_pool_user.c b/net/core/page_pool_user.c
index 278294aca66ab..3a3277ba167b1 100644
--- a/net/core/page_pool_user.c
+++ b/net/core/page_pool_user.c
@@ -103,8 +103,6 @@ netdev_nl_page_pool_get_dump(struct sk_buff *skb, struct netlink_callback *cb,
mutex_unlock(&page_pools_lock);
rtnl_unlock();

- if (skb->len && err == -EMSGSIZE)
- return skb->len;
return err;
}

--
2.43.0