From 615e1d89dc8c0fa7fc6ed2d57586949cec97fde2 Mon Sep 17 00:00:00 2001
From: dujunbao <14829755+du-junbao@user.noreply.gitee.com>
Date: Tue, 22 Sep 2026 21:11:55 +0800
Subject: [PATCH] urma: uburma: return a negative errno when the ubcore device
 is gone

uburma_open() reports a missing ubcore device with `ret = EIO`. EIO is
positive, so the file operation returns 5 instead of an error code.

The VFS requires ->open() to return a negative errno. do_dentry_open()
runs the positive value through WARN_ON_ONCE() in cleanup_all and
substitutes -EINVAL, so opening the character device while the ubcore
device has already been detached (uburma_remove_dev() clears
ubu_dev->ubc_dev) both emits a kernel warning and reports the wrong errno
to userspace.

Every other error return in this file and the surrounding URMA code uses
a negative errno; do the same here.

Fixes: 21bafff09f96 ("uburma: implement jetty resource control and command structures")
---
 drivers/ub/urma/uburma/uburma_dev_ops.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/ub/urma/uburma/uburma_dev_ops.c b/drivers/ub/urma/uburma/uburma_dev_ops.c
index 51fb42ecddbc..8e0f637b67de 100644
--- a/drivers/ub/urma/uburma/uburma_dev_ops.c
+++ b/drivers/ub/urma/uburma/uburma_dev_ops.c
@@ -180,7 +180,7 @@ int uburma_open(struct inode *inode, struct file *filp)
 	srcu_idx = srcu_read_lock(&ubu_dev->ubc_dev_srcu);
 	ubc_dev = srcu_dereference(ubu_dev->ubc_dev, &ubu_dev->ubc_dev_srcu);
 	if (!ubc_dev) {
-		ret = EIO;
+		ret = -EIO;
 		uburma_log_err("can not find ubcore device.\n");
 		goto err;
 	}
-- 
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