linux-kernel - [PATCH 10/23] gpiolib: cdev: Don't check struct gpio_chip in gpio_chrdev

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Message-ID: <20260116081036.352286-11-tzungbi@kernel.org>
Date: Fri, 16 Jan 2026 08:10:23 +0000
From: Tzung-Bi Shih <tzungbi@...nel.org>
To: Benson Leung <bleung@...omium.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	"Rafael J . Wysocki" <rafael@...nel.org>,
	Danilo Krummrich <dakr@...nel.org>,
	Bartosz Golaszewski <brgl@...ev.pl>,
	Linus Walleij <linusw@...nel.org>
Cc: Jonathan Corbet <corbet@....net>,
	Shuah Khan <shuah@...nel.org>,
	linux-doc@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	chrome-platform@...ts.linux.dev,
	linux-kselftest@...r.kernel.org,
	tzungbi@...nel.org,
	Laurent Pinchart <laurent.pinchart@...asonboard.com>,
	Wolfram Sang <wsa+renesas@...g-engineering.com>,
	Simona Vetter <simona.vetter@...ll.ch>,
	Dan Williams <dan.j.williams@...el.com>,
	Jason Gunthorpe <jgg@...dia.com>,
	linux-gpio@...r.kernel.org
Subject: [PATCH 10/23] gpiolib: cdev: Don't check struct gpio_chip in gpio_chrdev_open()

It's harmless even if: chrdev_open() and cdev_device_del() run at the
same time, and gpio_chrdev_open() gets called after the underlying GPIO
chip has gone.  The subsequent file operations check the availability
of struct gpio_chip anyway.

Don't check struct gpio_chip in gpio_chrdev_open().

Signed-off-by: Tzung-Bi Shih <tzungbi@...nel.org>
---
 drivers/gpio/gpiolib-cdev.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index 24449bbe38c9..e42cfdb47885 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -2689,13 +2689,7 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file)
 	struct gpio_device *gdev = container_of(inode->i_cdev,
 						struct gpio_device, chrdev);
 	struct gpio_chardev_data *cdev;
-	int ret = -ENOMEM;
-
-	guard(srcu)(&gdev->srcu);
-
-	/* Fail on open if the backing gpiochip is gone */
-	if (!rcu_access_pointer(gdev->chip))
-		return -ENODEV;
+	int ret;
 
 	cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
 	if (!cdev)
-- 
2.52.0.457.g6b5491de43-goog