Commit a8020807 authored by Bartosz Golaszewski's avatar Bartosz Golaszewski
Browse files

gpio: shared: don't allocate the lookup table until we really need it 



We allocate memory for the GPIO lookup table at the top of
gpio_shared_add_proxy_lookup() but we don't use it until the very end.
Depending on the timing, we may return earlier. Move the allocation
towards the end.

Fixes: a060b8c5 ("gpiolib: implement low-level, shared GPIO support")
Tested-by: default avatarMark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20260106-gpio-shared-fixes-v2-3-c7091d2f7581@oss.qualcomm.com


Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
parent 476e44d0

drivers/gpio/gpiolib-shared.c

+6 −6
Original line number Diff line number Diff line
@@ -443,14 +443,10 @@ int gpio_shared_add_proxy_lookup(struct device *consumer, const char *con_id, 
				 unsigned long lflags)

{

	const char *dev_id = dev_name(consumer);

	struct gpiod_lookup_table *lookup;

	struct gpio_shared_entry *entry;

	struct gpio_shared_ref *ref;



	struct gpiod_lookup_table *lookup __free(kfree) =

			kzalloc(struct_size(lookup, table, 2), GFP_KERNEL);

	if (!lookup)

		return -ENOMEM;



	list_for_each_entry(entry, &gpio_shared_list, list) {

		list_for_each_entry(ref, &entry->refs, list) {

			guard(mutex)(&ref->lock);
@@ -482,6 +478,10 @@ int gpio_shared_add_proxy_lookup(struct device *consumer, const char *con_id, 
			if (!key)

				return -ENOMEM;



			lookup = kzalloc(struct_size(lookup, table, 2), GFP_KERNEL);

			if (!lookup)

				return -ENOMEM;



			pr_debug("Adding machine lookup entry for a shared GPIO for consumer %s, with key '%s' and con_id '%s'\n",

				 dev_id, key, ref->con_id ?: "none");
@@ -489,7 +489,7 @@ int gpio_shared_add_proxy_lookup(struct device *consumer, const char *con_id, 
			lookup->table[0] = GPIO_LOOKUP(no_free_ptr(key), 0,

						       ref->con_id, lflags);



			ref->lookup = no_free_ptr(lookup);

			ref->lookup = lookup;

			gpiod_add_lookup_table(ref->lookup);



			return 0;