Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.37 as permitted sender) client-ip=23.128.96.37;
From:   Masahiro Yamada <masahiroy@kernel.org>
To:     Linus Walleij <linus.walleij@linaro.org>,
        Bartosz Golaszewski <brgl@bgdev.pl>, linux-gpio@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org,
        Masahiro Yamada <masahiroy@kernel.org>
Subject: [PATCH 1/2] pinctrl: pinconf-generic: resize the pin config array directly
Date:   Tue, 21 Nov 2023 07:28:31 +0900
Message-Id: <20231120222832.4063882-2-masahiroy@kernel.org>
In-Reply-To: <20231120222832.4063882-1-masahiroy@kernel.org>
References: <20231120222832.4063882-1-masahiroy@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

pinconf_generic_parse_dt_config() allocates memory that is large enough
to contain all the config parameters. Then, kmemdup() copies the found
configs to the memory with the exact size.

There is no need to allocate memory twice; you can directly resize the
initial memory using krealloc_array().

I also changed kcalloc() to kmalloc_array() to keep the consistency with
krealloc_array(). This change has no impact because you do not need to
zero out the 'cfg' array.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 drivers/pinctrl/pinconf-generic.c | 25 ++++++++-----------------
 1 file changed, 8 insertions(+), 17 deletions(-)

diff --git a/drivers/pinctrl/pinconf-generic.c b/drivers/pinctrl/pinconf-generic.c
index 8313cb5f3b3c..ba4fe2466e78 100644
--- a/drivers/pinctrl/pinconf-generic.c
+++ b/drivers/pinctrl/pinconf-generic.c
@@ -247,7 +247,6 @@ int pinconf_generic_parse_dt_config(struct device_node *np,
 {
 	unsigned long *cfg;
 	unsigned int max_cfg, ncfg = 0;
-	int ret;
 
 	if (!np)
 		return -EINVAL;
@@ -256,7 +255,7 @@ int pinconf_generic_parse_dt_config(struct device_node *np,
 	max_cfg = ARRAY_SIZE(dt_params);
 	if (pctldev)
 		max_cfg += pctldev->desc->num_custom_params;
-	cfg = kcalloc(max_cfg, sizeof(*cfg), GFP_KERNEL);
+	cfg = kmalloc_array(max_cfg, sizeof(*cfg), GFP_KERNEL);
 	if (!cfg)
 		return -ENOMEM;
 
@@ -266,30 +265,22 @@ int pinconf_generic_parse_dt_config(struct device_node *np,
 		parse_dt_cfg(np, pctldev->desc->custom_params,
 			     pctldev->desc->num_custom_params, cfg, &ncfg);
 
-	ret = 0;
-
 	/* no configs found at all */
 	if (ncfg == 0) {
+		kfree(cfg);
 		*configs = NULL;
 		*nconfigs = 0;
-		goto out;
+		return 0;
 	}
 
-	/*
-	 * Now limit the number of configs to the real number of
-	 * found properties.
-	 */
-	*configs = kmemdup(cfg, ncfg * sizeof(unsigned long), GFP_KERNEL);
-	if (!*configs) {
-		ret = -ENOMEM;
-		goto out;
-	}
+	/* Now resize the array to store the real number of found properties. */
+	*configs = krealloc_array(cfg, ncfg, sizeof(unsigned long), GFP_KERNEL);
+	if (!*configs)
+		return -ENOMEM;
 
 	*nconfigs = ncfg;
 
-out:
-	kfree(cfg);
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(pinconf_generic_parse_dt_config);
 
-- 
2.40.1