[PATCH 4.19 22/54] rxrpc: Fix sendmsg(MSG_WAITALL) handling

[Greg Kroah-Hartman]

From: David Howells <dhowells@xxxxxxxxxx>

commit 498b577660f08cef5d9e78e0ed6dcd4c0939e98c upstream.

Fix the handling of sendmsg() with MSG_WAITALL for userspace to round the
timeout for when a signal occurs up to at least two jiffies as a 1 jiffy
timeout may end up being effectively 0 if jiffies wraps at the wrong time.

Fixes: bc5e3a546d55 ("rxrpc: Use MSG_WAITALL to tell sendmsg() to temporarily ignore signals")
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

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

--- a/net/rxrpc/sendmsg.c
+++ b/net/rxrpc/sendmsg.c
@@ -62,8 +62,8 @@ static int rxrpc_wait_for_tx_window_noni
 
 	rtt = READ_ONCE(call->peer->rtt);
 	rtt2 = nsecs_to_jiffies64(rtt) * 2;
-	if (rtt2 < 1)
-		rtt2 = 1;
+	if (rtt2 < 2)
+		rtt2 = 2;
 
 	timeout = rtt2;
 	tx_start = READ_ONCE(call->tx_hard_ack);