Re: [PATCH 6/9] nilfs2: fix out-of-range warning

Justin Stitt
2024-03-28T22:05:02Z

On Thu, Mar 28, 2024 at 7:32 AM Arnd Bergmann <arnd@kernel.org> wrote:
>
> From: Arnd Bergmann <arnd@arndb.de>
>
> clang-14 points out that v_size is always smaller than a 64KB
> page size if that is configured by the CPU architecture:

Is this only with clang-14?

>
> fs/nilfs2/ioctl.c:63:19: error: result of comparison of constant 65536 with expression of type '__u16' (aka 'unsigned short') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
> if (argv->v_size > PAGE_SIZE)
> ~~~~~~~~~~~~ ^ ~~~~~~~~~
>
> This is ok, so just shut up that warning with a cast.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

My question out of curiosity aside,

Reviewed-by: Justin Stitt <justinstitt@google.com>

> ---
> fs/nilfs2/ioctl.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
> index f1a01c191cf5..8be471ce4f19 100644
> --- a/fs/nilfs2/ioctl.c
> +++ b/fs/nilfs2/ioctl.c
> @@ -60,7 +60,7 @@ static int nilfs_ioctl_wrap_copy(struct the_nilfs *nilfs,
> if (argv->v_nmembs == 0)
> return 0;
>
> - if (argv->v_size > PAGE_SIZE)
> + if ((size_t)argv->v_size > PAGE_SIZE)
> return -EINVAL;
>
> /*
> --
> 2.39.2
>