diff --git a/include/net/dst_ops.h b/include/net/dst_ops.h index f3f5d02f2e734e77f064ab7a008f4e4075d64047..0b4ab27d125afd16bd4582ccc393bb3bec43ca97 100644 --- a/include/net/dst_ops.h +++ b/include/net/dst_ops.h @@ -25,7 +25,8 @@ struct dst_ops { void (*destroy)(struct dst_entry *); void (*ifdown)(struct dst_entry *, struct net_device *dev, int how); - struct dst_entry * (*negative_advice)(struct dst_entry *); + KABI_REPLACE(struct dst_entry * (*negative_advice)(struct dst_entry *), + void (*negative_advice)(struct sock *sk, struct dst_entry *)) void (*link_failure)(struct sk_buff *); void (*update_pmtu)(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb, u32 mtu, diff --git a/include/net/sock.h b/include/net/sock.h index 5025cc924a8c790e17512add6b14501cd8f17156..2a78dd3495774b692f0fec54916e6b681add17d5 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2017,17 +2017,10 @@ sk_dst_get(struct sock *sk) static inline void __dst_negative_advice(struct sock *sk) { - struct dst_entry *ndst, *dst = __sk_dst_get(sk); + struct dst_entry *dst = __sk_dst_get(sk); - if (dst && dst->ops->negative_advice) { - ndst = dst->ops->negative_advice(dst); - - if (ndst != dst) { - rcu_assign_pointer(sk->sk_dst_cache, ndst); - sk_tx_queue_clear(sk); - sk->sk_dst_pending_confirm = 0; - } - } + if (dst && dst->ops->negative_advice) + dst->ops->negative_advice(sk, dst); } static inline void dst_negative_advice(struct sock *sk) @@ -2042,7 +2035,7 @@ __sk_dst_set(struct sock *sk, struct dst_entry *dst) struct dst_entry *old_dst; sk_tx_queue_clear(sk); - sk->sk_dst_pending_confirm = 0; + WRITE_ONCE(sk->sk_dst_pending_confirm, 0); old_dst = rcu_dereference_protected(sk->sk_dst_cache, lockdep_sock_is_held(sk)); rcu_assign_pointer(sk->sk_dst_cache, dst); @@ -2055,7 +2048,7 @@ sk_dst_set(struct sock *sk, struct dst_entry *dst) struct dst_entry *old_dst; sk_tx_queue_clear(sk); - sk->sk_dst_pending_confirm = 0; + WRITE_ONCE(sk->sk_dst_pending_confirm, 0); old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst); dst_release(old_dst); } diff --git a/net/core/sock.c b/net/core/sock.c index d8d42ff15d209bd2f351d9539abdf9bf13cef4d8..54b8444ac12b752d376b3c879fb676302c840ac9 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -532,7 +532,7 @@ struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie) if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) { sk_tx_queue_clear(sk); - sk->sk_dst_pending_confirm = 0; + WRITE_ONCE(sk->sk_dst_pending_confirm, 0); RCU_INIT_POINTER(sk->sk_dst_cache, NULL); dst_release(dst); return NULL; diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 6f8d2e1fde0573cca23b88312b4d7b742319835f..e38377ad9b01c99f86d3510b67ad4106adecd79a 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -137,7 +137,8 @@ static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); static unsigned int ipv4_default_advmss(const struct dst_entry *dst); static unsigned int ipv4_mtu(const struct dst_entry *dst); -static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); +static void ipv4_negative_advice(struct sock *sk, + struct dst_entry *dst); static void ipv4_link_failure(struct sk_buff *skb); static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb, u32 mtu, @@ -866,22 +867,15 @@ static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buf __ip_do_redirect(rt, skb, &fl4, true); } -static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) +static void ipv4_negative_advice(struct sock *sk, + struct dst_entry *dst) { struct rtable *rt = (struct rtable *)dst; - struct dst_entry *ret = dst; - if (rt) { - if (dst->obsolete > 0) { - ip_rt_put(rt); - ret = NULL; - } else if ((rt->rt_flags & RTCF_REDIRECTED) || - rt->dst.expires) { - ip_rt_put(rt); - ret = NULL; - } - } - return ret; + if ((dst->obsolete > 0) || + (rt->rt_flags & RTCF_REDIRECTED) || + rt->dst.expires) + sk_dst_reset(sk); } /* diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index f32351a8f031cc9b124a43d4bb3f61bc0d1df0a7..4f53078a59bd9faf1850797ded6c45e5bd7497f0 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1373,7 +1373,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, skb_set_hash_from_sk(skb, sk); refcount_add(skb->truesize, &sk->sk_wmem_alloc); - skb_set_dst_pending_confirm(skb, sk->sk_dst_pending_confirm); + skb_set_dst_pending_confirm(skb, READ_ONCE(sk->sk_dst_pending_confirm)); /* Build TCP header and checksum it. */ th = (struct tcphdr *)skb->data; diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 36fbefad2a0540eb0b29f5ba7f2cc6665c4a53d5..fe570e795395c5423154fe1a408794f9d9a53f43 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -85,7 +85,8 @@ enum rt6_nud_state { static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie); static unsigned int ip6_default_advmss(const struct dst_entry *dst); static unsigned int ip6_mtu(const struct dst_entry *dst); -static struct dst_entry *ip6_negative_advice(struct dst_entry *); +static void ip6_negative_advice(struct sock *sk, + struct dst_entry *dst); static void ip6_dst_destroy(struct dst_entry *); static void ip6_dst_ifdown(struct dst_entry *, struct net_device *dev, int how); @@ -2630,24 +2631,24 @@ static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie) return dst_ret; } -static struct dst_entry *ip6_negative_advice(struct dst_entry *dst) +static void ip6_negative_advice(struct sock *sk, + struct dst_entry *dst) { struct rt6_info *rt = (struct rt6_info *) dst; - if (rt) { - if (rt->rt6i_flags & RTF_CACHE) { - rcu_read_lock(); - if (rt6_check_expired(rt)) { - rt6_remove_exception_rt(rt); - dst = NULL; - } - rcu_read_unlock(); - } else { - dst_release(dst); - dst = NULL; + if (rt->rt6i_flags & RTF_CACHE) { + rcu_read_lock(); + if (rt6_check_expired(rt)) { + /* counteract the dst_release() in sk_dst_reset() */ + dst_hold(dst); + sk_dst_reset(sk); + + rt6_remove_exception_rt(rt); } + rcu_read_unlock(); + return; } - return dst; + sk_dst_reset(sk); } static void ip6_link_failure(struct sk_buff *skb) diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index 78a687d5ab3e8d5de8ba40d1e92a22ffe8eb993c..ed86a41404e874848b6c8055e370e67ea39a2d5d 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -3785,15 +3785,10 @@ static void xfrm_link_failure(struct sk_buff *skb) /* Impossible. Such dst must be popped before reaches point of failure. */ } -static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst) +static void xfrm_negative_advice(struct sock *sk, struct dst_entry *dst) { - if (dst) { - if (dst->obsolete) { - dst_release(dst); - dst = NULL; - } - } - return dst; + if (dst->obsolete) + sk_dst_reset(sk); } static void xfrm_init_pmtu(struct xfrm_dst **bundle, int nr)