diff options
author | David S. Miller <davem@davemloft.net> | 2019-10-13 10:13:08 -0700 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2019-10-13 10:13:08 -0700 |
commit | 3f233809aa7f00da6b42c695cc20801a2050edd4 (patch) | |
tree | 7be26ef02ab2f2979be9a3cdeb36ed1bafc51354 /include/net/sock.h | |
parent | 8caf8a91f34d55e8e3b1355ee8d658cb472146e2 (diff) | |
parent | ab4e846a82d0ae00176de19f2db3c5c64f8eb5f2 (diff) |
Merge branch 'tcp-address-KCSAN-reports-in-tcp_poll-part-I'
Eric Dumazet says:
====================
tcp: address KCSAN reports in tcp_poll() (part I)
This all started with a KCSAN report (included
in "tcp: annotate tp->rcv_nxt lockless reads" changelog)
tcp_poll() runs in a lockless way. This means that about
all accesses of tcp socket fields done in tcp_poll() context
need annotations otherwise KCSAN will complain about data-races.
While doing this detective work, I found a more serious bug,
addressed by the first patch ("tcp: add rcu protection around
tp->fastopen_rsk").
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/sock.h')
-rw-r--r-- | include/net/sock.h | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/include/net/sock.h b/include/net/sock.h index 79f54e1f8827..f69b58bff7e5 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -878,12 +878,17 @@ static inline bool sk_acceptq_is_full(const struct sock *sk) */ static inline int sk_stream_min_wspace(const struct sock *sk) { - return sk->sk_wmem_queued >> 1; + return READ_ONCE(sk->sk_wmem_queued) >> 1; } static inline int sk_stream_wspace(const struct sock *sk) { - return sk->sk_sndbuf - sk->sk_wmem_queued; + return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued); +} + +static inline void sk_wmem_queued_add(struct sock *sk, int val) +{ + WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val); } void sk_stream_write_space(struct sock *sk); @@ -1207,7 +1212,7 @@ static inline void sk_refcnt_debug_release(const struct sock *sk) static inline bool __sk_stream_memory_free(const struct sock *sk, int wake) { - if (sk->sk_wmem_queued >= sk->sk_sndbuf) + if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf)) return false; return sk->sk_prot->stream_memory_free ? @@ -1467,7 +1472,7 @@ DECLARE_STATIC_KEY_FALSE(tcp_tx_skb_cache_key); static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb) { sock_set_flag(sk, SOCK_QUEUE_SHRUNK); - sk->sk_wmem_queued -= skb->truesize; + sk_wmem_queued_add(sk, -skb->truesize); sk_mem_uncharge(sk, skb->truesize); if (static_branch_unlikely(&tcp_tx_skb_cache_key) && !sk->sk_tx_skb_cache && !skb_cloned(skb)) { @@ -2014,7 +2019,7 @@ static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *fro skb->len += copy; skb->data_len += copy; skb->truesize += copy; - sk->sk_wmem_queued += copy; + sk_wmem_queued_add(sk, copy); sk_mem_charge(sk, copy); return 0; } @@ -2220,10 +2225,14 @@ static inline void sk_wake_async(const struct sock *sk, int how, int band) static inline void sk_stream_moderate_sndbuf(struct sock *sk) { - if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) { - sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1); - sk->sk_sndbuf = max_t(u32, sk->sk_sndbuf, SOCK_MIN_SNDBUF); - } + u32 val; + + if (sk->sk_userlocks & SOCK_SNDBUF_LOCK) + return; + + val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1); + + WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF)); } struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp, @@ -2251,7 +2260,7 @@ bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag); */ static inline bool sock_writeable(const struct sock *sk) { - return refcount_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1); + return refcount_read(&sk->sk_wmem_alloc) < (READ_ONCE(sk->sk_sndbuf) >> 1); } static inline gfp_t gfp_any(void) |