From: Bartosz Golaszewski <[email protected]>
If a GPIO driver returns a positive integer from one of the direction
setter callbacks, we'll end up propagating it to user-space. Whether we
should sanitize the values returned by callbacks is a different question
but let's first improve the documentation and fortify the contract with
GPIO providers.
Reported-by: José Guilherme de Castro Rodrigues <[email protected]>
Signed-off-by: Bartosz Golaszewski <[email protected]>
---
v1 -> v2:
- add a mention of 0 being return on success
include/linux/gpio/driver.h | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index 9a5c6c76e653..90cd57796b36 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -335,10 +335,12 @@ struct gpio_irq_chip {
* (same as GPIO_LINE_DIRECTION_OUT / GPIO_LINE_DIRECTION_IN),
* or negative error. It is recommended to always implement this
* function, even on input-only or output-only gpio chips.
- * @direction_input: configures signal "offset" as input, or returns error
- * This can be omitted on input-only or output-only gpio chips.
- * @direction_output: configures signal "offset" as output, or returns error
- * This can be omitted on input-only or output-only gpio chips.
+ * @direction_input: configures signal "offset" as input, returns 0 on success
+ * or a negative error number. This can be omitted on input-only or
+ * output-only gpio chips.
+ * @direction_output: configures signal "offset" as output, returns 0 on
+ * success or a negative error number. This can be omitted on input-only
+ * or output-only gpio chips.
* @get: returns value for signal "offset", 0=low, 1=high, or negative error
* @get_multiple: reads values for multiple signals defined by "mask" and
* stores them in "bits", returns 0 on success or negative error
--
2.40.1
On Thu, Jan 25, 2024 at 09:35:07AM +0100, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <[email protected]>
>
> If a GPIO driver returns a positive integer from one of the direction
> setter callbacks, we'll end up propagating it to user-space. Whether we
> should sanitize the values returned by callbacks is a different question
> but let's first improve the documentation and fortify the contract with
> GPIO providers.
>
> Reported-by: Jos? Guilherme de Castro Rodrigues <[email protected]>
> Signed-off-by: Bartosz Golaszewski <[email protected]>
Reviewed-by: Kent Gibson <[email protected]>
> ---
> v1 -> v2:
> - add a mention of 0 being return on success
>
> include/linux/gpio/driver.h | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
> index 9a5c6c76e653..90cd57796b36 100644
> --- a/include/linux/gpio/driver.h
> +++ b/include/linux/gpio/driver.h
> @@ -335,10 +335,12 @@ struct gpio_irq_chip {
> * (same as GPIO_LINE_DIRECTION_OUT / GPIO_LINE_DIRECTION_IN),
> * or negative error. It is recommended to always implement this
> * function, even on input-only or output-only gpio chips.
> - * @direction_input: configures signal "offset" as input, or returns error
> - * This can be omitted on input-only or output-only gpio chips.
> - * @direction_output: configures signal "offset" as output, or returns error
> - * This can be omitted on input-only or output-only gpio chips.
> + * @direction_input: configures signal "offset" as input, returns 0 on success
> + * or a negative error number. This can be omitted on input-only or
> + * output-only gpio chips.
> + * @direction_output: configures signal "offset" as output, returns 0 on
> + * success or a negative error number. This can be omitted on input-only
> + * or output-only gpio chips.
> * @get: returns value for signal "offset", 0=low, 1=high, or negative error
> * @get_multiple: reads values for multiple signals defined by "mask" and
> * stores them in "bits", returns 0 on success or negative error
> --
> 2.40.1
>