Hi I skimmed through the sscanf source code and it seems that it can't return a negative value at all. I think, this should be: r = sscanf(str, "%llu-%llu%c", &b, &e, &dummy); if (r != 2) return -EINVAL; Mikulas On Sun, 22 Sep 2024, Dipendra Khadka 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); > -- > 2.43.0 >