Commit 6f9b3e77 authored by Bartosz Golaszewski's avatar Bartosz Golaszewski Committed by Linus Walleij
Browse files

gpio: mockup: improve the debugfs input sanitization

We're currently only checking the first character of the input to the
debugfs event files, so a string like '0sdfdsf' is valid and indicates
a falling edge event.

Be more strict and only allow '0', '1', '0\n' & '1\n'.

While we're at it: move the sanitization code before the irq_enabled
check so that we indicate an error on invalid input even if nobody is
waiting for events.

Signed-off-by: default avatarBartosz Golaszewski <>
Reviewed-by: default avatarAndy Shevchenko <>
Signed-off-by: default avatarLinus Walleij <>
parent b6730b20
......@@ -208,8 +208,7 @@ static ssize_t gpio_mockup_event_write(struct file *file,
struct seq_file *sfile;
struct gpio_desc *desc;
struct gpio_chip *gc;
int val;
char buf;
int rv, val;
sfile = file->private_data;
priv = sfile->private;
......@@ -217,19 +216,15 @@ static ssize_t gpio_mockup_event_write(struct file *file,
chip = priv->chip;
gc = &chip->gc;
rv = kstrtoint_from_user(usr_buf, size, 0, &val);
if (rv)
return rv;
if (val != 0 && val != 1)
return -EINVAL;
if (!chip->lines[priv->offset].irq_enabled)
return size;
if (copy_from_user(&buf, usr_buf, 1))
return -EFAULT;
if (buf == '0')
val = 0;
else if (buf == '1')
val = 1;
return -EINVAL;
gpiod_set_value_cansleep(desc, val);
priv->chip->irq_ctx.irq = gc->irq_base + priv->offset;
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