[PATCH AUTOSEL 5.4 14/32] rxrpc: Fix sendmsg(MSG_WAITALL) handling

Sasha Levin
2020-04-07T00:06:55Z

From: David Howells <dhowells@redhat.com>

[ Upstream commit 498b577660f08cef5d9e78e0ed6dcd4c0939e98c ]

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@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/rxrpc/sendmsg.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
index 1eccfb92c9e15..0fcf157aa09f8 100644
--- a/net/rxrpc/sendmsg.c
+++ b/net/rxrpc/sendmsg.c
@@ -71,8 +71,8 @@ static int rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock *rx,

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);
--
2.20.1