gpiolib: Replace open coded krealloc()

gpiod_get_array() does a new allocation in some cases, followed
by copying previously allocated placeholder for the descriptors.

Replace that with krealloc(__GFP_ZERO), since it was kzalloc()
originally.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 9451a62..65253db 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -4277,12 +4277,14 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
        struct gpio_array *array_info = NULL;
        struct gpio_chip *gc;
        int count, bitmap_size;
+       size_t descs_size;
 
        count = gpiod_count(dev, con_id);
        if (count < 0)
                return ERR_PTR(count);
 
-       descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
+       descs_size = struct_size(descs, desc, count);
+       descs = kzalloc(descs_size, GFP_KERNEL);
        if (!descs)
                return ERR_PTR(-ENOMEM);
 
@@ -4306,20 +4308,17 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
                        bitmap_size = BITS_TO_LONGS(gc->ngpio > count ?
                                                    gc->ngpio : count);
 
-                       array = kzalloc(struct_size(descs, desc, count) +
-                                       struct_size(array_info, invert_mask,
-                                       3 * bitmap_size), GFP_KERNEL);
+                       array = krealloc(descs, descs_size +
+                                        struct_size(array_info, invert_mask, 3 * bitmap_size),
+                                        GFP_KERNEL | __GFP_ZERO);
                        if (!array) {
                                gpiod_put_array(descs);
                                return ERR_PTR(-ENOMEM);
                        }
 
-                       memcpy(array, descs,
-                              struct_size(descs, desc, descs->ndescs + 1));
-                       kfree(descs);
-
                        descs = array;
-                       array_info = (void *)(descs->desc + count);
+
+                       array_info = (void *)descs + descs_size;
                        array_info->get_mask = array_info->invert_mask +
                                                  bitmap_size;
                        array_info->set_mask = array_info->get_mask +