linux-kernel - [PATCH 1/2] gpio: sysfs: Obey valid

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Date:   Mon, 29 Mar 2021 14:41:12 +0300
From:   Matti Vaittinen <matti.vaittinen@...rohmeurope.com>
To:     matti.vaittinen@...rohmeurope.com, mazziesaccount@...il.com
Cc:     Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>,
        Stephen Boyd <sboyd@...eaurora.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 1/2] gpio: sysfs: Obey valid_mask

Do not allow exporting GPIOs which are set invalid
by the driver's valid mask.

Fixes: 726cb3ba49692bdae6caff457755e7cdb432efa4

Signed-off-by: Matti Vaittinen <matti.vaittinen@...rohmeurope.com>
---
 drivers/gpio/gpiolib-sysfs.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index 26c5466b8179..ae49bb23c6ed 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -458,6 +458,8 @@ static ssize_t export_store(struct class *class,
 	long			gpio;
 	struct gpio_desc	*desc;
 	int			status;
+	struct gpio_chip	*gc;
+	int			offset;
 
 	status = kstrtol(buf, 0, &gpio);
 	if (status < 0)
@@ -469,6 +471,12 @@ static ssize_t export_store(struct class *class,
 		pr_warn("%s: invalid GPIO %ld\n", __func__, gpio);
 		return -EINVAL;
 	}
+	gc = desc->gdev->chip;
+	offset = gpio_chip_hwgpio(desc);
+	if (!gpiochip_line_is_valid(gc, offset)) {
+		pr_warn("%s: GPIO %ld masked\n", __func__, gpio);
+		return -EINVAL;
+	}
 
 	/* No extra locking here; FLAG_SYSFS just signifies that the
 	 * request and export were done by on behalf of userspace, so
-- 
2.25.4


-- 
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =]