diff mbox series

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

Message ID 20200904154547.3836-3-brgl@bgdev.pl (mailing list archive)
State Not Applicable, archived
Headers show
Series gpio: mockup: support dynamically created and removed chips | expand

Commit Message

Bartosz Golaszewski Sept. 4, 2020, 3:45 p.m. UTC
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(+)

Comments

Andy Shevchenko Sept. 4, 2020, 4:33 p.m. UTC | #1
On Fri, Sep 04, 2020 at 05:45:26PM +0200, Bartosz Golaszewski wrote:
> 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;

Shouldn't we expect that caller will supply NULL, 0 and above check is not
needed?

> +	for (i = 0; i < num_str; i++)
> +		kfree(str_array[i]);
> +	kfree(str_array);

> +}
> +EXPORT_SYMBOL_GPL(kfree_strarray);
> -- 
> 2.26.1
>
diff mbox series

Patch

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);