diff options
| author | Eric Dumazet <edumazet@google.com> | 2025-06-30 12:19:30 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-07-02 14:32:30 -0700 |
| commit | 88fe14253e181878c2ddb51a298ae8c468a63010 (patch) | |
| tree | 286cfc2407b49e5e9e55129f020d7ee8a393c052 /net/core/dst.c | |
| parent | 2dce8c52a98995c4719def6f88629ab1581c0b82 (diff) | |
net: dst: add four helpers to annotate data-races around dst->dev
dst->dev is read locklessly in many contexts,
and written in dst_dev_put().
Fixing all the races is going to need many changes.
We probably will have to add full RCU protection.
Add three helpers to ease this painful process.
static inline struct net_device *dst_dev(const struct dst_entry *dst)
{
return READ_ONCE(dst->dev);
}
static inline struct net_device *skb_dst_dev(const struct sk_buff *skb)
{
return dst_dev(skb_dst(skb));
}
static inline struct net *skb_dst_dev_net(const struct sk_buff *skb)
{
return dev_net(skb_dst_dev(skb));
}
static inline struct net *skb_dst_dev_net_rcu(const struct sk_buff *skb)
{
return dev_net_rcu(skb_dst_dev(skb));
}
Fixes: 4a6ce2b6f2ec ("net: introduce a new function dst_dev_put()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250630121934.3399505-7-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/core/dst.c')
| -rw-r--r-- | net/core/dst.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/core/dst.c b/net/core/dst.c index 52e824e57c17..e2de8b68c41d 100644 --- a/net/core/dst.c +++ b/net/core/dst.c @@ -150,7 +150,7 @@ void dst_dev_put(struct dst_entry *dst) dst->ops->ifdown(dst, dev); WRITE_ONCE(dst->input, dst_discard); WRITE_ONCE(dst->output, dst_discard_out); - dst->dev = blackhole_netdev; + WRITE_ONCE(dst->dev, blackhole_netdev); netdev_ref_replace(dev, blackhole_netdev, &dst->dev_tracker, GFP_ATOMIC); } @@ -263,7 +263,7 @@ unsigned int dst_blackhole_mtu(const struct dst_entry *dst) { unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); - return mtu ? : dst->dev->mtu; + return mtu ? : dst_dev(dst)->mtu; } EXPORT_SYMBOL_GPL(dst_blackhole_mtu); |