Re: [PATCH 1/9] dm integrity: fix out-of-range warning

Mikulas Patocka
2024-03-28T18:36:34Z

On Thu, 28 Mar 2024, Arnd Bergmann wrote:

> From: Arnd Bergmann <arnd@arndb.de>
>
> Depending on the value of CONFIG_HZ, clang compares about a pointless
> comparison:
>
> drivers/md/dm-integrity.c:4085:12: error: result of comparison of constant 42949672950 with expression of type 'unsigned int' is always false [-Werror,-Wtautological-constant-out-of-range-compare]
> if (val >= (uint64_t)UINT_MAX * 1000 / HZ) {
>
> As the check remains useful for other configurations, shut up the
> warning by adding a second type cast to uint64_t.
>
> Fixes: 468dfca38b1a ("dm integrity: add a bitmap mode")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>

> ---
> drivers/md/dm-integrity.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
> index 37b9f8f1ae1a..7f3dc8ee6ab8 100644
> --- a/drivers/md/dm-integrity.c
> +++ b/drivers/md/dm-integrity.c
> @@ -4221,7 +4221,7 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned int argc, char **argv
> } else if (sscanf(opt_string, "sectors_per_bit:%llu%c", &llval, &dummy) == 1) {
> log2_sectors_per_bitmap_bit = !llval ? 0 : __ilog2_u64(llval);
> } else if (sscanf(opt_string, "bitmap_flush_interval:%u%c", &val, &dummy) == 1) {
> - if (val >= (uint64_t)UINT_MAX * 1000 / HZ) {
> + if ((uint64_t)val >= (uint64_t)UINT_MAX * 1000 / HZ) {
> r = -EINVAL;
> ti->error = "Invalid bitmap_flush_interval argument";
> goto bad;
> --
> 2.39.2
>