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* [PATCH] gpio: bcm-kona: remove kcalloc
@ 2026-03-11  0:34 Rosen Penev
  2026-03-11  8:46 ` Bartosz Golaszewski
  0 siblings, 1 reply; 2+ messages in thread
From: Rosen Penev @ 2026-03-11  0:34 UTC (permalink / raw)
  To: linux-gpio
  Cc: Ray Jui, Broadcom internal kernel review list, Linus Walleij,
	Bartosz Golaszewski, Florian Fainelli, Scott Branden, Kees Cook,
	Gustavo A. R. Silva, open list,
	open list:KERNEL HARDENING (not covered by other
	areas):Keyword:b__counted_by(_le|_be)?b

Simplify allocation by using a flexible array member.

Use __counted_by for extra runtime analysis.

Shuffle some code as __counted_by requires the counting variable to be
set right after allocation.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/gpio/gpio-bcm-kona.c | 37 ++++++++++++++++--------------------
 1 file changed, 16 insertions(+), 21 deletions(-)

diff --git a/drivers/gpio/gpio-bcm-kona.c b/drivers/gpio/gpio-bcm-kona.c
index 208b71c59d58..b1d32d590cf8 100644
--- a/drivers/gpio/gpio-bcm-kona.c
+++ b/drivers/gpio/gpio-bcm-kona.c
@@ -58,15 +58,6 @@
 #define LOCK_CODE				0xffffffff
 #define UNLOCK_CODE				0x00000000
 
-struct bcm_kona_gpio {
-	void __iomem *reg_base;
-	int num_bank;
-	raw_spinlock_t lock;
-	struct gpio_chip gpio_chip;
-	struct irq_domain *irq_domain;
-	struct bcm_kona_gpio_bank *banks;
-};
-
 struct bcm_kona_gpio_bank {
 	int id;
 	int irq;
@@ -90,6 +81,15 @@ struct bcm_kona_gpio_bank {
 	struct bcm_kona_gpio *kona_gpio;
 };
 
+struct bcm_kona_gpio {
+	void __iomem *reg_base;
+	int num_bank;
+	raw_spinlock_t lock;
+	struct gpio_chip gpio_chip;
+	struct irq_domain *irq_domain;
+	struct bcm_kona_gpio_bank banks[] __counted_by(num_bank);
+};
+
 static inline void bcm_kona_gpio_write_lock_regs(void __iomem *reg_base,
 						int bank_id, u32 lockcode)
 {
@@ -584,12 +584,6 @@ static int bcm_kona_gpio_probe(struct platform_device *pdev)
 	int ret;
 	int i;
 
-	kona_gpio = devm_kzalloc(dev, sizeof(*kona_gpio), GFP_KERNEL);
-	if (!kona_gpio)
-		return -ENOMEM;
-
-	kona_gpio->gpio_chip = template_chip;
-	chip = &kona_gpio->gpio_chip;
 	ret = platform_irq_count(pdev);
 	if (!ret) {
 		dev_err(dev, "Couldn't determine # GPIO banks\n");
@@ -597,6 +591,11 @@ static int bcm_kona_gpio_probe(struct platform_device *pdev)
 	} else if (ret < 0) {
 		return dev_err_probe(dev, ret, "Couldn't determine GPIO banks\n");
 	}
+
+	kona_gpio = devm_kzalloc(dev, struct_size(kona_gpio, banks, ret), GFP_KERNEL);
+	if (!kona_gpio)
+		return -ENOMEM;
+
 	kona_gpio->num_bank = ret;
 
 	if (kona_gpio->num_bank > GPIO_MAX_BANK_NUM) {
@@ -604,13 +603,9 @@ static int bcm_kona_gpio_probe(struct platform_device *pdev)
 			GPIO_MAX_BANK_NUM);
 		return -ENXIO;
 	}
-	kona_gpio->banks = devm_kcalloc(dev,
-					kona_gpio->num_bank,
-					sizeof(*kona_gpio->banks),
-					GFP_KERNEL);
-	if (!kona_gpio->banks)
-		return -ENOMEM;
 
+	kona_gpio->gpio_chip = template_chip;
+	chip = &kona_gpio->gpio_chip;
 	chip->parent = dev;
 	chip->ngpio = kona_gpio->num_bank * GPIO_PER_BANK;
 
-- 
2.53.0


^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH] gpio: bcm-kona: remove kcalloc
  2026-03-11  0:34 [PATCH] gpio: bcm-kona: remove kcalloc Rosen Penev
@ 2026-03-11  8:46 ` Bartosz Golaszewski
  0 siblings, 0 replies; 2+ messages in thread
From: Bartosz Golaszewski @ 2026-03-11  8:46 UTC (permalink / raw)
  To: linux-gpio, Rosen Penev
  Cc: Bartosz Golaszewski, Ray Jui,
	Broadcom internal kernel review list, Linus Walleij,
	Bartosz Golaszewski, Florian Fainelli, Scott Branden, Kees Cook,
	Gustavo A. R. Silva, linux-kernel, linux-hardening


On Tue, 10 Mar 2026 17:34:31 -0700, Rosen Penev wrote:
> Simplify allocation by using a flexible array member.
> 
> Use __counted_by for extra runtime analysis.
> 
> Shuffle some code as __counted_by requires the counting variable to be
> set right after allocation.
> 
> [...]

Applied, thanks!

[1/1] gpio: bcm-kona: remove kcalloc
      https://git.kernel.org/brgl/c/0258fe8721f541bbd3949cac2f4971b98e1fe4ed

Best regards,
-- 
Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2026-03-11  8:46 UTC | newest]

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2026-03-11  8:46 ` Bartosz Golaszewski

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