[PATCH 4.9 59/78] tcp: Revert "tcp: tcp_probe: use spin_lock_bh()"

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet@xxxxxxxxxx>

commit 29869d66870a715177bfb505f66a7e0e8bcc89c3 upstream.

This reverts commit e70ac171658679ecf6bea4bbd9e9325cd6079d2b.

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@xxxxxxxxxx>
Reported-by: kernel test robot <xiaolong.ye@xxxxxxxxx>
Cc: Ricardo Nabinger Sanchez <rnsanchez@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 net/ipv4/tcp_probe.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/ipv4/tcp_probe.c
+++ b/net/ipv4/tcp_probe.c
@@ -117,7 +117,7 @@ static void jtcp_rcv_established(struct
 	     (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
 			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);
 	}