linux-kernel - [PATCH v1 1/2] gpiolib: Replace open coded krealloc()

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Message-Id: <20230321135412.73240-1-andriy.shevchenko@linux.intel.com>
Date:   Tue, 21 Mar 2023 15:54:11 +0200
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Bartosz Golaszewski <bartosz.golaszewski@...aro.org>,
        linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <brgl@...ev.pl>
Subject: [PATCH v1 1/2] 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@...ux.intel.com>
---
 drivers/gpio/gpiolib.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 112d99a5eec4..3e94990f1f90 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -4283,12 +4283,14 @@ 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);
 
@@ -4312,20 +4314,17 @@ 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 +
-- 
2.40.0.1.gaa8946217a0b