On Wed, 2017-05-03 at 17:04 +0100, David Howells wrote:
> Provide a function, kstrcreate(), that will create a NUL-terminated string
> from an unterminated character array where the length is known in advance.
>
> This is better than kstrndup() in situations where we already know the
> string length as the strnlen() in kstrndup() is superfluous.
>
> Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
> ---
>
> include/linux/string.h | 1 +
> mm/util.c | 22 ++++++++++++++++++++++
> 2 files changed, 23 insertions(+)
>
> diff --git a/include/linux/string.h b/include/linux/string.h
> index 26b6f6a66f83..5596ae56ce0a 100644
> --- a/include/linux/string.h
> +++ b/include/linux/string.h
> @@ -122,6 +122,7 @@ extern void kfree_const(const void *x);
> extern char *kstrdup(const char *s, gfp_t gfp) __malloc;
> extern const char *kstrdup_const(const char *s, gfp_t gfp);
> extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
> +extern char *kstrcreate(const char *s, size_t len, gfp_t gfp);
> extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
>
> extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
> diff --git a/mm/util.c b/mm/util.c
> index 656dc5e37a87..01887bbdb11e 100644
> --- a/mm/util.c
> +++ b/mm/util.c
> @@ -103,6 +103,28 @@ char *kstrndup(const char *s, size_t max, gfp_t gfp)
> EXPORT_SYMBOL(kstrndup);
>
> /**
> + * kstrcreate - Create a NUL-terminated string from unterminated data
> + * @s: The data to stringify
> + * @len: The size of the data
> + * @gfp: the GFP mask used in the kmalloc() call when allocating memory
> + */
> +char *kstrcreate(const char *s, size_t len, gfp_t gfp)
> +{
> + char *buf;
> +
> + if (!s)
> + return NULL;
> +
> + buf = kmalloc_track_caller(len + 1, gfp);
> + if (buf) {
> + memcpy(buf, s, len);
> + buf[len] = '\0';
> + }
> + return buf;
> +}
> +EXPORT_SYMBOL(kstrcreate);
> +
> +/**
> * kmemdup - duplicate region of memory
> *
> * @src: memory region to duplicate
>
>
I haven't gotten to the part where this gets used yet, but it looks like
a nice helper.
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxxxxxxx>
