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gpio: shared: verify con_id when adding proxy lookup

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When matching the firmware node with the potential consumer, we
currently omit the con_id string. This can lead to false positives in
the unlikely case of the consumer having been assigned more than one
shared GPIO. Check the connector ID before proceeding.

Fixes: a060b8c511ab ("gpiolib: implement low-level, shared GPIO support")
Link: https://lore.kernel.org/r/20251222-gpio-shared-reset-gpio-proxy-v1-2-8d4bba7d8c14@oss.qualcomm.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
This commit is contained in:
Bartosz Golaszewski 2025-12-22 11:01:27 +01:00
parent 9700b0fccf
commit cb0451e33b
3 changed files with 11 additions and 3 deletions
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7
drivers/gpio/gpiolib-shared.c
View File

@ -365,7 +365,8 @@ static bool gpio_shared_dev_is_reset_gpio(struct device *consumer,
}
#endif /* CONFIG_RESET_GPIO */
int gpio_shared_add_proxy_lookup(struct device *consumer, unsigned long lflags)
int gpio_shared_add_proxy_lookup(struct device *consumer, const char *con_id,
unsigned long lflags)
{
const char *dev_id = dev_name(consumer);
struct gpio_shared_entry *entry;
@ -384,6 +385,10 @@ int gpio_shared_add_proxy_lookup(struct device *consumer, unsigned long lflags)
guard(mutex)(&ref->lock);
if ((!con_id && ref->con_id) || (con_id && !ref->con_id) ||
(con_id && ref->con_id && strcmp(con_id, ref->con_id) != 0))
continue;
/* We've already done that on a previous request. */
if (ref->lookup)
return 0;

4
drivers/gpio/gpiolib-shared.h
View File

@ -16,7 +16,8 @@ struct device;
int gpio_device_setup_shared(struct gpio_device *gdev);
void gpio_device_teardown_shared(struct gpio_device *gdev);
int gpio_shared_add_proxy_lookup(struct device *consumer, unsigned long lflags);
int gpio_shared_add_proxy_lookup(struct device *consumer, const char *con_id,
unsigned long lflags);
#else
@ -28,6 +29,7 @@ static inline int gpio_device_setup_shared(struct gpio_device *gdev)
static inline void gpio_device_teardown_shared(struct gpio_device *gdev) { }
static inline int gpio_shared_add_proxy_lookup(struct device *consumer,
const char *con_id,
unsigned long lflags)
{
return 0;

3
drivers/gpio/gpiolib.c
View File

@ -4717,7 +4717,8 @@ struct gpio_desc *gpiod_find_and_request(struct device *consumer,
* lookup table for the proxy device as previously
* we only knew the consumer's fwnode.
*/
ret = gpio_shared_add_proxy_lookup(consumer, lookupflags);
ret = gpio_shared_add_proxy_lookup(consumer, con_id,
lookupflags);
if (ret)
return ERR_PTR(ret);