Commit 0a10d107 authored by Bartosz Golaszewski's avatar Bartosz Golaszewski
Browse files

gpiolib: allocate memory atomically with a spinlock held 



We will eventually switch to protecting the GPIO descriptors with a mutex
but until then, we need to allocate memory for the label copy atomically
while we're holding the global spinlock.

Reported-by: default avatarDan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/linux-gpio/62588146-eed6-42f7-ba26-160226b109fe@moroto.mountain/T/#u


Fixes: f8d05e27 ("gpiolib: remove gpiochip_is_requested()")
Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent d22f93c6

drivers/gpio/gpiolib.c

+9 −1
Original line number Diff line number Diff line
@@ -2399,7 +2399,15 @@ char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset) 
	if (!test_bit(FLAG_REQUESTED, &desc->flags))

		return NULL;



	label = kstrdup(desc->label, GFP_KERNEL);

	/*

	 * FIXME: Once we mark gpiod_direction_input/output() and

	 * gpiod_get_direction() with might_sleep(), we'll be able to protect

	 * the GPIO descriptors with mutex (while value setting operations will

	 * become lockless).

	 *

	 * Until this happens, this allocation needs to be atomic.

	 */

	label = kstrdup(desc->label, GFP_ATOMIC);

	if (!label)

		return ERR_PTR(-ENOMEM);