tcp: Revert "tcp: tcp_probe: use spin_lock_bh()"

commit 29869d6 upstream.

This reverts commit e70ac17.

jtcp_rcv_established() is in fact called with hard irq being disabled.

Initial bug report from Ricardo Nabinger Sanchez [1] still needs
to be investigated, but does not look like a TCP bug.

[1] https://www.spinics.net/lists/netdev/msg420960.html

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Cc: Ricardo Nabinger Sanchez <rnsanchez@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: edumazet

net/ipv4/tcp_probe.c

@@ -117,7 +117,7 @@ static void jtcp_rcv_established(struct sock *sk, struct sk_buff *skb,
 	     (fwmark > 0 && skb->mark == fwmark)) &&
 	    (full || tp->snd_cwnd != tcp_probe.lastcwnd)) {
 
-		spin_lock_bh(&tcp_probe.lock);
+		spin_lock(&tcp_probe.lock);
 		/* If log fills, just silently drop */
 		if (tcp_probe_avail() > 1) {
 			struct tcp_log *p = tcp_probe.log + tcp_probe.head;
@@ -157,7 +157,7 @@ static void jtcp_rcv_established(struct sock *sk, struct sk_buff *skb,
 			tcp_probe.head = (tcp_probe.head + 1) & (bufsize - 1);
 		}
 		tcp_probe.lastcwnd = tp->snd_cwnd;
-		spin_unlock_bh(&tcp_probe.lock);
+		spin_unlock(&tcp_probe.lock);
 
 		wake_up(&tcp_probe.wait);
 	}