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| author | Jakub Kicinski <kuba@kernel.org> | 2025-08-29 19:36:34 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-08-29 19:36:34 -0700 |
| commit | 864ecc4a6dade82d3f70eab43dad0e277aa6fc78 (patch) | |
| tree | 2c8e7f3348c118943fec8933dbd1462224555985 /include | |
| parent | Merge branch 'inet_diag-make-dumps-faster-with-simple-filters' (diff) | |
| parent | ipv4: start using dst_dev_rcu() (diff) | |
| download | linux-864ecc4a6dade82d3f70eab43dad0e277aa6fc78.tar.gz linux-864ecc4a6dade82d3f70eab43dad0e277aa6fc78.zip | |
Merge branch 'net-add-rcu-safety-to-dst-dev'
Eric Dumazet says:
====================
net: add rcu safety to dst->dev
Followup of commit 88fe14253e18 ("net: dst: add four helpers
to annotate data-races around dst->dev").
Use lockdep enabled helpers to convert our unsafe dst->dev
uses one at a time.
More to come...
====================
Link: https://patch.msgid.link/20250828195823.3958522-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/dst.h | 16 | ||||
| -rw-r--r-- | include/net/ip.h | 6 | ||||
| -rw-r--r-- | include/net/ip6_route.h | 2 | ||||
| -rw-r--r-- | include/net/route.h | 2 |
4 files changed, 17 insertions, 9 deletions
diff --git a/include/net/dst.h b/include/net/dst.h index bab01363bb97..f8aa1239b4db 100644 --- a/include/net/dst.h +++ b/include/net/dst.h @@ -24,7 +24,10 @@ struct sk_buff; struct dst_entry { - struct net_device *dev; + union { + struct net_device *dev; + struct net_device __rcu *dev_rcu; + }; struct dst_ops *ops; unsigned long _metrics; unsigned long expires; @@ -570,9 +573,12 @@ static inline struct net_device *dst_dev(const struct dst_entry *dst) static inline struct net_device *dst_dev_rcu(const struct dst_entry *dst) { - /* In the future, use rcu_dereference(dst->dev) */ - WARN_ON_ONCE(!rcu_read_lock_held()); - return READ_ONCE(dst->dev); + return rcu_dereference(dst->dev_rcu); +} + +static inline struct net *dst_dev_net_rcu(const struct dst_entry *dst) +{ + return dev_net_rcu(dst_dev_rcu(dst)); } static inline struct net_device *skb_dst_dev(const struct sk_buff *skb) @@ -592,7 +598,7 @@ static inline struct net *skb_dst_dev_net(const struct sk_buff *skb) static inline struct net *skb_dst_dev_net_rcu(const struct sk_buff *skb) { - return dev_net_rcu(skb_dst_dev(skb)); + return dev_net_rcu(skb_dst_dev_rcu(skb)); } struct dst_entry *dst_blackhole_check(struct dst_entry *dst, u32 cookie); diff --git a/include/net/ip.h b/include/net/ip.h index befcba575129..6dbd2bf8fa9c 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -467,12 +467,14 @@ static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst, bool forwarding) { const struct rtable *rt = dst_rtable(dst); + const struct net_device *dev; unsigned int mtu, res; struct net *net; rcu_read_lock(); - net = dev_net_rcu(dst_dev(dst)); + dev = dst_dev_rcu(dst); + net = dev_net_rcu(dev); if (READ_ONCE(net->ipv4.sysctl_ip_fwd_use_pmtu) || ip_mtu_locked(dst) || !forwarding) { @@ -486,7 +488,7 @@ static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst, if (mtu) goto out; - mtu = READ_ONCE(dst_dev(dst)->mtu); + mtu = READ_ONCE(dev->mtu); if (unlikely(ip_mtu_locked(dst))) { if (rt->rt_uses_gateway && mtu > 576) diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h index 9255f21818ee..59f48ca3abdf 100644 --- a/include/net/ip6_route.h +++ b/include/net/ip6_route.h @@ -337,7 +337,7 @@ static inline unsigned int ip6_dst_mtu_maybe_forward(const struct dst_entry *dst mtu = IPV6_MIN_MTU; rcu_read_lock(); - idev = __in6_dev_get(dst_dev(dst)); + idev = __in6_dev_get(dst_dev_rcu(dst)); if (idev) mtu = READ_ONCE(idev->cnf.mtu6); rcu_read_unlock(); diff --git a/include/net/route.h b/include/net/route.h index c71998f464f8..f90106f383c5 100644 --- a/include/net/route.h +++ b/include/net/route.h @@ -390,7 +390,7 @@ static inline int ip4_dst_hoplimit(const struct dst_entry *dst) const struct net *net; rcu_read_lock(); - net = dev_net_rcu(dst_dev(dst)); + net = dst_dev_net_rcu(dst); hoplimit = READ_ONCE(net->ipv4.sysctl_ip_default_ttl); rcu_read_unlock(); } |