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authorBartosz Golaszewski <bartosz.golaszewski@linaro.org>2023-08-11 21:30:34 +0200
committerBartosz Golaszewski <bartosz.golaszewski@linaro.org>2023-08-16 13:35:50 +0200
commit3386fb86ecdef0d39ee3306aea8ec290e61b934f (patch)
tree665aafebab585a83dfedd8b584b8e00c19546f44 /drivers/gpio/gpiolib.c
parent20d9b3b5f2749673e1b5e9c8b0846ff6deff4032 (diff)
gpiolib: fix reference leaks when removing GPIO chips still in use
After we remove a GPIO chip that still has some requested descriptors, gpiod_free_commit() will fail and we will never put the references to the GPIO device and the owning module in gpiod_free(). Rework this function to: - not warn on desc == NULL as this is a use-case on which most free functions silently return - put the references to desc->gdev and desc->gdev->owner unconditionally so that the release callback actually gets called when the remaining references are dropped by external GPIO users Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio/gpiolib.c')
-rw-r--r--drivers/gpio/gpiolib.c16
1 files changed, 11 insertions, 5 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 251c875b5c34..76e0c38026c3 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2167,12 +2167,18 @@ static bool gpiod_free_commit(struct gpio_desc *desc)
void gpiod_free(struct gpio_desc *desc)
{
- if (desc && desc->gdev && gpiod_free_commit(desc)) {
- module_put(desc->gdev->owner);
- gpio_device_put(desc->gdev);
- } else {
+ /*
+ * We must not use VALIDATE_DESC_VOID() as the underlying gdev->chip
+ * may already be NULL but we still want to put the references.
+ */
+ if (!desc)
+ return;
+
+ if (!gpiod_free_commit(desc))
WARN_ON(extra_checks);
- }
+
+ module_put(desc->gdev->owner);
+ gpio_device_put(desc->gdev);
}
/**