[PATCH 02/23] lib: string_helpers: provide kfree_strarray()

From: Bartosz Golaszewski <brgl@bgdev.pl>
To: Linus Walleij <linus.walleij@linaro.org>,
	Jonathan Corbet <corbet@lwn.net>,
	Mika Westerberg <mika.westerberg@linux.intel.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Kent Gibson <warthog618@gmail.com>
Cc: linux-gpio@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>
Subject: [PATCH 02/23] lib: string_helpers: provide kfree_strarray()
Date: Fri,  4 Sep 2020 17:45:26 +0200	[thread overview]
Message-ID: <20200904154547.3836-3-brgl@bgdev.pl> (raw)
In-Reply-To: <20200904154547.3836-1-brgl@bgdev.pl>

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

There's a common pattern of dynamically allocating an array of char
pointers and then also dynamically allocating each string in this
array. Provide a helper for freeing such a string array with one call.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 include/linux/string_helpers.h |  2 ++
 lib/string_helpers.c           | 22 ++++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h
index 86f150c2a6b6..55b25120a1c6 100644
--- a/include/linux/string_helpers.h
+++ b/include/linux/string_helpers.h
@@ -94,4 +94,6 @@ char *kstrdup_quotable(const char *src, gfp_t gfp);
 char *kstrdup_quotable_cmdline(struct task_struct *task, gfp_t gfp);
 char *kstrdup_quotable_file(struct file *file, gfp_t gfp);
 
+void kfree_strarray(char **str_array, size_t num_str);
+
 #endif
diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index 963050c0283e..22505efc6aae 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -649,3 +649,25 @@ char *kstrdup_quotable_file(struct file *file, gfp_t gfp)
 	return pathname;
 }
 EXPORT_SYMBOL_GPL(kstrdup_quotable_file);
+
+/**
+ * kfree_strarray - free a number of dynamically allocated strings contained
+ *                  in an array and the array itself
+ *
+ * @str_array: Dynamically allocated array of strings to free. If NULL - the
+ *             function does nothing.
+ * @num_str: Number of strings (starting from the beginning of the array) to
+ *           free.
+ */
+void kfree_strarray(char **str_array, size_t num_str)
+{
+	unsigned int i;
+
+	if (!str_array)
+		return;
+
+	for (i = 0; i < num_str; i++)
+		kfree(str_array[i]);
+	kfree(str_array);
+}
+EXPORT_SYMBOL_GPL(kfree_strarray);
-- 
2.26.1

