diff options
| author | Bartosz Golaszewski <bartosz.golaszewski@linaro.org> | 2023-12-12 11:55:01 +0100 |
|---|---|---|
| committer | Bartosz Golaszewski <bartosz.golaszewski@linaro.org> | 2023-12-15 16:43:24 +0100 |
| commit | 0a10d107818cc4def73723ba3101aae0d25ea353 (patch) | |
| tree | 082320c605c077a3f9ca8b1f3ed8108fafead054 /drivers/gpio/gpiolib.c | |
| parent | d22f93c6a0df15b9d1f500ab57d97ecc99b3657a (diff) | |
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: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/linux-gpio/62588146-eed6-42f7-ba26-160226b109fe@moroto.mountain/T/#u
Fixes: f8d05e276b45 ("gpiolib: remove gpiochip_is_requested()")
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.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 4e190be75dc2..6efe44570333 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -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); |