diff mbox series

[v1,1/2] gpiolib: Replace open coded krealloc()

Message ID 20230321135412.73240-1-andriy.shevchenko@linux.intel.com
State Accepted
Commit 79736429c97f517247645e73e75c956efd09ad03
Headers show
Series [v1,1/2] gpiolib: Replace open coded krealloc() | expand

Commit Message

Andy Shevchenko March 21, 2023, 1:54 p.m. UTC
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>
---
 drivers/gpio/gpiolib.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

Comments

Linus Walleij March 23, 2023, 8:17 a.m. UTC | #1
On Tue, Mar 21, 2023 at 2:53 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:

> 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>

Wow that's a really nice patch!
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij
Linus Walleij March 23, 2023, 8:18 a.m. UTC | #2
On Tue, Mar 21, 2023 at 2:53 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:

> gpiod_get_array() has a long if-else-if branching where each of them
> tests for the same variable to be not NULL. Instead, check for NULL
> before even going to that flow.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

It's way more readable like this.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij
Bartosz Golaszewski March 29, 2023, 4:12 p.m. UTC | #3
On Tue, Mar 21, 2023 at 2:53 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> 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>
> ---

Series applied, thanks!

Bart
diff mbox series

Patch

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 +