[patch] gpio: mockup: return -EFAULT if copy_from_user() fails

Dan Carpenter
2017-02-14T23:02:06Z

copy_from_user() returns the number of bytes remaining to be copied but
we want to return negative error codes on failue.

Fixes: 9202ba2397d1 ("gpio: mockup: implement event injecting over debugfs")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
index 06dac72cb69c..d99338689213 100644
--- a/drivers/gpio/gpio-mockup.c
+++ b/drivers/gpio/gpio-mockup.c
@@ -197,7 +197,7 @@ static ssize_t gpio_mockup_event_write(struct file *file,
struct seq_file *sfile;
struct gpio_desc *desc;
struct gpio_chip *gc;
- int status, val;
+ int val;
char buf;

sfile = file->private_data;
@@ -206,9 +206,8 @@ static ssize_t gpio_mockup_event_write(struct file *file,
chip = priv->chip;
gc = &chip->gc;

- status = copy_from_user(&buf, usr_buf, 1);
- if (status)
- return status;
+ if (copy_from_user(&buf, usr_buf, 1))
+ return -EFAULT;

if (buf = '0')
val = 0;