tcp: fix recv with flags MSG_WAITALL | MSG_PEEK
Currently, tcp_recvmsg enters a busy loop in sk_wait_data if called
with flags = MSG_WAITALL | MSG_PEEK.
sk_wait_data waits for sk_receive_queue not empty, but in this case,
the receive queue is not empty, but does not contain any skb that we
can use.
Add a "last skb seen on receive queue" argument to sk_wait_data, so
that it sleeps until the receive queue has new skbs.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=99461
Link: https://sourceware.org/bugzilla/show_bug.cgi?id=18493
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1205258
Reported-by: Enrico Scholz <rh-bugzilla@ensc.de>
Reported-by: Dan Searle <dan@censornet.com>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c
index 8fd9feb..8dab4e5 100644
--- a/net/llc/af_llc.c
+++ b/net/llc/af_llc.c
@@ -613,7 +613,7 @@
if (signal_pending(current))
break;
rc = 0;
- if (sk_wait_data(sk, &timeo))
+ if (sk_wait_data(sk, &timeo, NULL))
break;
}
return rc;
@@ -802,7 +802,7 @@
release_sock(sk);
lock_sock(sk);
} else
- sk_wait_data(sk, &timeo);
+ sk_wait_data(sk, &timeo, NULL);
if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) {
net_dbg_ratelimited("LLC(%s:%d): Application bug, race in MSG_PEEK\n",