From: Ben Dooks <ben.dooks@codethink.co.uk>
To: linux-kernel@lists.codethink.co.uk
Cc: Ben Dooks <ben.dooks@codethink.co.uk>,
Linus Walleij <linus.walleij@linaro.org>,
Alexandre Courbot <gnurou@gmail.com>,
linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] gpiolib: check if gpio_desc pointer is error or NULL
Date: Tue, 18 Mar 2014 11:41:30 +0100 [thread overview]
Message-ID: <1395139290-4207-1-git-send-email-ben.dooks@codethink.co.uk> (raw)
Some of the gpiod_ calls take a pointer to a gpio_desc as their
argument but only check to see if it is NULL to validate the
input.
Calls such as devm_gpiod_get() return an error-pointer if they
fail, so doing the following will not work:
gpio = devm_gpiod_get(...);
gpiod_direction_output(gpio, 0);
The sequence produces an OOPS like:
Unable to handle kernel paging request at virtual address fffffffe
Change all calls that check for !desc to use IS_ERR_OR_NULL() to
avoid these issues.
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
---
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: linux-gpio@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
drivers/gpio/gpiolib.c | 38 +++++++++++++++++++-------------------
1 file changed, 19 insertions(+), 19 deletions(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 50c4922..e69ac5e 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -817,7 +817,7 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
return -ENOENT;
}
- if (!desc) {
+ if (IS_ERR_OR_NULL(desc)) {
pr_debug("%s: invalid gpio descriptor\n", __func__);
return -EINVAL;
}
@@ -903,7 +903,7 @@ int gpiod_export_link(struct device *dev, const char *name,
{
int status = -EINVAL;
- if (!desc) {
+ if (IS_ERR_OR_NULL(desc)) {
pr_warn("%s: invalid GPIO\n", __func__);
return -EINVAL;
}
@@ -986,7 +986,7 @@ void gpiod_unexport(struct gpio_desc *desc)
int status = 0;
struct device *dev = NULL;
- if (!desc) {
+ if (IS_ERR_OR_NULL(desc)) {
pr_warn("%s: invalid GPIO\n", __func__);
return;
}
@@ -1463,7 +1463,7 @@ static int gpiod_request(struct gpio_desc *desc, const char *label)
int status = -EPROBE_DEFER;
unsigned long flags;
- if (!desc) {
+ if (IS_ERR_OR_NULL(desc)) {
pr_warn("%s: invalid GPIO\n", __func__);
return -EINVAL;
}
@@ -1529,7 +1529,7 @@ static void gpiod_free(struct gpio_desc *desc)
might_sleep();
- if (!desc) {
+ if (IS_ERR_OR_NULL(desc)) {
WARN_ON(extra_checks);
return;
}
@@ -1703,7 +1703,7 @@ int gpiod_direction_input(struct gpio_desc *desc)
int status = -EINVAL;
int offset;
- if (!desc || !desc->chip) {
+ if (IS_ERR_OR_NULL(desc) || !desc->chip) {
pr_warn("%s: invalid GPIO\n", __func__);
return -EINVAL;
}
@@ -1773,7 +1773,7 @@ int gpiod_direction_output(struct gpio_desc *desc, int value)
int status = -EINVAL;
int offset;
- if (!desc || !desc->chip) {
+ if (IS_ERR_OR_NULL(desc) || !desc->chip) {
pr_warn("%s: invalid GPIO\n", __func__);
return -EINVAL;
}
@@ -1857,7 +1857,7 @@ int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
int status = -EINVAL;
int offset;
- if (!desc || !desc->chip) {
+ if (IS_ERR_OR_NULL(desc) || !desc->chip) {
pr_warn("%s: invalid GPIO\n", __func__);
return -EINVAL;
}
@@ -1953,7 +1953,7 @@ static int _gpiod_get_raw_value(const struct gpio_desc *desc)
*/
int gpiod_get_raw_value(const struct gpio_desc *desc)
{
- if (!desc)
+ if (IS_ERR_OR_NULL(desc))
return 0;
/* Should be using gpio_get_value_cansleep() */
WARN_ON(desc->chip->can_sleep);
@@ -1974,7 +1974,7 @@ EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
int gpiod_get_value(const struct gpio_desc *desc)
{
int value;
- if (!desc)
+ if (IS_ERR_OR_NULL(desc))
return 0;
/* Should be using gpio_get_value_cansleep() */
WARN_ON(desc->chip->can_sleep);
@@ -2068,7 +2068,7 @@ static void _gpiod_set_raw_value(struct gpio_desc *desc, int value)
*/
void gpiod_set_raw_value(struct gpio_desc *desc, int value)
{
- if (!desc)
+ if (IS_ERR_OR_NULL(desc))
return;
/* Should be using gpio_set_value_cansleep() */
WARN_ON(desc->chip->can_sleep);
@@ -2089,7 +2089,7 @@ EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
*/
void gpiod_set_value(struct gpio_desc *desc, int value)
{
- if (!desc)
+ if (IS_ERR_OR_NULL(desc))
return;
/* Should be using gpio_set_value_cansleep() */
WARN_ON(desc->chip->can_sleep);
@@ -2106,7 +2106,7 @@ EXPORT_SYMBOL_GPL(gpiod_set_value);
*/
int gpiod_cansleep(const struct gpio_desc *desc)
{
- if (!desc)
+ if (IS_ERR_OR_NULL(desc))
return 0;
return desc->chip->can_sleep;
}
@@ -2124,7 +2124,7 @@ int gpiod_to_irq(const struct gpio_desc *desc)
struct gpio_chip *chip;
int offset;
- if (!desc)
+ if (IS_ERR_OR_NULL(desc))
return -EINVAL;
chip = desc->chip;
offset = gpio_chip_hwgpio(desc);
@@ -2144,7 +2144,7 @@ EXPORT_SYMBOL_GPL(gpiod_to_irq);
*/
int gpiod_lock_as_irq(struct gpio_desc *desc)
{
- if (!desc)
+ if (IS_ERR_OR_NULL(desc))
return -EINVAL;
if (test_bit(FLAG_IS_OUT, &desc->flags)) {
@@ -2199,7 +2199,7 @@ EXPORT_SYMBOL_GPL(gpio_unlock_as_irq);
int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
{
might_sleep_if(extra_checks);
- if (!desc)
+ if (IS_ERR_OR_NULL(desc))
return 0;
return _gpiod_get_raw_value(desc);
}
@@ -2219,7 +2219,7 @@ int gpiod_get_value_cansleep(const struct gpio_desc *desc)
int value;
might_sleep_if(extra_checks);
- if (!desc)
+ if (IS_ERR_OR_NULL(desc))
return 0;
value = _gpiod_get_raw_value(desc);
@@ -2243,7 +2243,7 @@ EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
{
might_sleep_if(extra_checks);
- if (!desc)
+ if (IS_ERR_OR_NULL(desc))
return;
_gpiod_set_raw_value(desc, value);
}
@@ -2262,7 +2262,7 @@ EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
{
might_sleep_if(extra_checks);
- if (!desc)
+ if (IS_ERR_OR_NULL(desc))
return;
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
--
1.9.0
next reply other threads:[~2014-03-18 10:41 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-18 10:41 Ben Dooks [this message]
2014-03-19 1:48 ` [PATCH] gpiolib: check if gpio_desc pointer is error or NULL Alexandre Courbot
2014-03-19 8:33 ` Ben Dooks
2014-03-19 8:37 ` Alexandre Courbot
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