diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2009-12-04 01:06:13 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-12-04 01:06:13 +0100 |
| commit | 49d09007879ce7bee36ab453c73e97c00adce884 (patch) | |
| tree | 6b6a28e0fd8befd4bad5fb1474ce4e0dea9ed6dd /net/ipv4/tcp_ipv4.c | |
| parent | net: Fix ks8851 snl NULL pointer dereference Oops (diff) | |
| download | linux-49d09007879ce7bee36ab453c73e97c00adce884.tar.xz linux-49d09007879ce7bee36ab453c73e97c00adce884.zip | |
tcp: diag: Dont report negative values for rx queue
Both netlink and /proc/net/tcp interfaces can report transient
negative values for rx queue.
ss ->
State Recv-Q Send-Q Local Address:Port Peer Address:Port
ESTAB -6 6 127.0.0.1:45956 127.0.0.1:3333
netstat ->
tcp 4294967290 6 127.0.0.1:37784 127.0.0.1:3333 ESTABLISHED
This is because we dont lock socket while computing
tp->rcv_nxt - tp->copied_seq,
and another CPU can update copied_seq before rcv_next in RX path.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_ipv4.c')
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index fee9aabd5aa1..29002ab26e0d 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2318,6 +2318,7 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i, int *len) __be32 src = inet->inet_rcv_saddr; __u16 destp = ntohs(inet->inet_dport); __u16 srcp = ntohs(inet->inet_sport); + int rx_queue; if (icsk->icsk_pending == ICSK_TIME_RETRANS) { timer_active = 1; @@ -2333,12 +2334,19 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i, int *len) timer_expires = jiffies; } + if (sk->sk_state == TCP_LISTEN) + rx_queue = sk->sk_ack_backlog; + else + /* + * because we dont lock socket, we might find a transient negative value + */ + rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0); + seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX " "%08X %5d %8d %lu %d %p %lu %lu %u %u %d%n", i, src, srcp, dest, destp, sk->sk_state, tp->write_seq - tp->snd_una, - sk->sk_state == TCP_LISTEN ? sk->sk_ack_backlog : - (tp->rcv_nxt - tp->copied_seq), + rx_queue, timer_active, jiffies_to_clock_t(timer_expires - jiffies), icsk->icsk_retransmits, |