diff options
| author | Bartosz Golaszewski <bartosz.golaszewski@linaro.org> | 2023-08-11 21:30:34 +0200 |
|---|---|---|
| committer | Bartosz Golaszewski <bartosz.golaszewski@linaro.org> | 2023-08-16 13:35:50 +0200 |
| commit | 3386fb86ecdef0d39ee3306aea8ec290e61b934f (patch) | |
| tree | 665aafebab585a83dfedd8b584b8e00c19546f44 /drivers/gpio | |
| parent | 20d9b3b5f2749673e1b5e9c8b0846ff6deff4032 (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')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 16 |
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); } /** |