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gpiolib: check the return value of gpio_chip::get_direction()

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As per the API contract - gpio_chip::get_direction() may fail and return
a negative error number. However, we treat it as if it always returned 0
or 1. Check the return value of the callback and propagate the error
number up the stack.

Cc: stable@vger.kernel.org
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20250210-gpio-sanitize-retvals-v1-1-12ea88506cb2@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
This commit is contained in:
Bartosz Golaszewski 2025-02-10 11:51:55 +01:00
parent 0ad2507d5d
commit 9d846b1aeb
1 changed files with 29 additions and 15 deletions
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44
drivers/gpio/gpiolib.c
View file

@ -1057,8 +1057,11 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
desc->gdev = gdev;
if (gc->get_direction && gpiochip_line_is_valid(gc, desc_index)) {
assign_bit(FLAG_IS_OUT,
&desc->flags, !gc->get_direction(gc, desc_index));
ret = gc->get_direction(gc, desc_index);
if (ret < 0)
goto err_cleanup_desc_srcu;
assign_bit(FLAG_IS_OUT, &desc->flags, !ret);
} else {
assign_bit(FLAG_IS_OUT,
&desc->flags, !gc->direction_input);
@ -2728,13 +2731,18 @@ int gpiod_direction_input_nonotify(struct gpio_desc *desc)
if (guard.gc->direction_input) {
ret = guard.gc->direction_input(guard.gc,
gpio_chip_hwgpio(desc));
} else if (guard.gc->get_direction &&
(guard.gc->get_direction(guard.gc,
gpio_chip_hwgpio(desc)) != 1)) {
gpiod_warn(desc,
"%s: missing direction_input() operation and line is output\n",
__func__);
return -EIO;
} else if (guard.gc->get_direction) {
ret = guard.gc->get_direction(guard.gc,
gpio_chip_hwgpio(desc));
if (ret < 0)
return ret;
if (ret != GPIO_LINE_DIRECTION_IN) {
gpiod_warn(desc,
"%s: missing direction_input() operation and line is output\n",
__func__);
return -EIO;
}
}
if (ret == 0) {
clear_bit(FLAG_IS_OUT, &desc->flags);
@ -2771,12 +2779,18 @@ static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
gpio_chip_hwgpio(desc), val);
} else {
/* Check that we are in output mode if we can */
if (guard.gc->get_direction &&
guard.gc->get_direction(guard.gc, gpio_chip_hwgpio(desc))) {
gpiod_warn(desc,
"%s: missing direction_output() operation\n",
__func__);
return -EIO;
if (guard.gc->get_direction) {
ret = guard.gc->get_direction(guard.gc,
gpio_chip_hwgpio(desc));
if (ret < 0)
return ret;
if (ret != GPIO_LINE_DIRECTION_OUT) {
gpiod_warn(desc,
"%s: missing direction_output() operation\n",
__func__);
return -EIO;
}
}
/*
* If we can't actively set the direction, we are some