From 3026b0c9d933f3728b0a9dcd4d0e932c3698c6e7 Mon Sep 17 00:00:00 2001
From: Zhen Lei <thunder.leizhen@huawei.com>
Date: Sat, 8 May 2021 11:22:39 +0800
Subject: [PATCH] um: fix error return code in winch_tramp()

[ Upstream commit ccf1236ecac476d9d2704866d9a476c86e387971 ]

Fix to return a negative error code from the error handling case instead
of 0, as done elsewhere in this function.

Fixes: 89df6bfc0405 ("uml: DEBUG_SHIRQ fixes")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Acked-By: anton.ivanov@cambridgegreys.com
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/um/drivers/chan_user.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/um/drivers/chan_user.c b/arch/um/drivers/chan_user.c
index d8845d4aac6a7..6040817c036f3 100644
--- a/arch/um/drivers/chan_user.c
+++ b/arch/um/drivers/chan_user.c
@@ -256,7 +256,8 @@ static int winch_tramp(int fd, struct tty_port *port, int *fd_out,
 		goto out_close;
 	}
 
-	if (os_set_fd_block(*fd_out, 0)) {
+	err = os_set_fd_block(*fd_out, 0);
+	if (err) {
 		printk(UM_KERN_ERR "winch_tramp: failed to set thread_fd "
 		       "non-blocking.\n");
 		goto out_close;