On Mon, Sep 23, 2024 at 12:47 AM Dipendra Khadka <kdipendra88@xxxxxxxxx> wrote:
>
> Smatch reported following:
> '''
> drivers/md/dm-cache-target.c:3204 parse_cblock_range() warn: sscanf doesn't return error codes
> drivers/md/dm-cache-target.c:3217 parse_cblock_range() warn: sscanf doesn't return error codes
> '''
>
> Since, the only negative value that is returned by sscanf is -1.
> Returning -ENVAL when sscanf returns -1.
>
> Signed-off-by: Dipendra Khadka <kdipendra88@xxxxxxxxx>
> ---
> drivers/md/dm-cache-target.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
> index 17f0fab1e254..c35d65e310d6 100644
> --- a/drivers/md/dm-cache-target.c
> +++ b/drivers/md/dm-cache-target.c
> @@ -3200,8 +3200,8 @@ static int parse_cblock_range(struct cache *cache, const char *str,
> * Try and parse form (ii) first.
> */
> r = sscanf(str, "%llu-%llu%c", &b, &e, &dummy);
> - if (r < 0)
> - return r;
> + if (r == -1)
> + return -EINVAL;
>
> if (r == 2) {
> result->begin = to_cblock(b);
> @@ -3213,8 +3213,8 @@ static int parse_cblock_range(struct cache *cache, const char *str,
> * That didn't work, try form (i).
> */
> r = sscanf(str, "%llu%c", &b, &dummy);
> - if (r < 0)
> - return r;
> + if (r == -1)
> + return -EINVAL;
>
> if (r == 1) {
> result->begin = to_cblock(b);
Could you please clarify how to reproduce unexpected results? From
what I observe, the kernel's sscanf doesn't return -1 on an empty
input. Even if a negative value other than -EINVAL is returned, it is
handled by the callers.
Hank
> --
> 2.43.0
>
>
