On Thu, Sep 24, 2020 at 01:38:34PM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
>
> 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.
For consistency I would like to provide kalloc_strarray(), but it seems a bit
ambiguous. So I'm fine with this going alone.
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
> ---
> 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..56c01ec8a076 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.
Can we use same names as done for other string array related functions, i.e.
str_array -> array
num_str -> n
?
(See *match_string() APIs)
> + *
> + * Passing a non-null str_array and num_str == 0 as well as NULL str_array and
> + * num_str == 0 are valid use-cases.
You still may refer to the parameters in the description using @param notation,
like @str_array.
> + */
> +void kfree_strarray(char **str_array, size_t num_str)
> +{
> + unsigned int i;
> +
> + for (i = 0; i < num_str; i++)
> + kfree(str_array[i]);
> + kfree(str_array);
> +}
> +EXPORT_SYMBOL_GPL(kfree_strarray);
> --
> 2.26.1
>
--
With Best Regards,
Andy Shevchenko
