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From: Justin Stitt <justinstitt@google.com>
Date: Thu, 28 Mar 2024 15:04:49 -0700
Message-ID: <CAFhGd8oJ5trNE7na9jCDbEt5kox1rg0mia59EHj+XikHUnay5w@mail.gmail.com>
Subject: Re: [PATCH 6/9] nilfs2: fix out-of-range warning
To: Arnd Bergmann <arnd@kernel.org>
Cc: linux-kernel@vger.kernel.org, Ryusuke Konishi <konishi.ryusuke@gmail.com>, 
	Nathan Chancellor <nathan@kernel.org>, Arnd Bergmann <arnd@arndb.de>, 
	Nick Desaulniers <ndesaulniers@google.com>, Bill Wendling <morbo@google.com>, 
	Andrew Morton <akpm@linux-foundation.org>, Philipp Stanner <pstanner@redhat.com>, 
	Christian Brauner <brauner@kernel.org>, Jeff Layton <jlayton@kernel.org>, 
	Thorsten Blum <thorsten.blum@toblux.com>, linux-nilfs@vger.kernel.org, 
	llvm@lists.linux.dev
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On Thu, Mar 28, 2024 at 7:32=E2=80=AFAM Arnd Bergmann <arnd@kernel.org> wro=
te:
>
> 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 wi=
th expression of type '__u16' (aka 'unsigned short') is always false [-Werr=
or,-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 *nilf=
s,
>         if (argv->v_nmembs =3D=3D 0)
>                 return 0;
>
> -       if (argv->v_size > PAGE_SIZE)
> +       if ((size_t)argv->v_size > PAGE_SIZE)
>                 return -EINVAL;
>
>         /*
> --
> 2.39.2
>