2021-08-24 03:19:49

by Austin Kim

Subject: [PATCH] cachefiles: remove always false 'datalen < 0' expression

From: Austin Kim <[email protected]>

Since 'datalen' is declared as size_t, the 'datalen < 0' expression
is always false. Where size_t is defined as below;

typedef unsigned long __kernel_ulong_t;
typedef __kernel_ulong_t __kernel_size_t;
typedef __kernel_size_t size_t;

So it had better remove unnecessary 'always false' expression.

Signed-off-by: Austin Kim <[email protected]>
---
fs/cachefiles/daemon.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/cachefiles/daemon.c b/fs/cachefiles/daemon.c
index 752c1e43416f..1cfed9e0812a 100644
--- a/fs/cachefiles/daemon.c
+++ b/fs/cachefiles/daemon.c
@@ -225,7 +225,7 @@ static ssize_t cachefiles_daemon_write(struct file *file,
if (test_bit(CACHEFILES_DEAD, &cache->flags))
return -EIO;

- if (datalen < 0 || datalen > PAGE_SIZE - 1)
+ if (datalen > PAGE_SIZE - 1)
return -EOPNOTSUPP;

/* drag the command string into the kernel so we can parse it */
--
2.20.1

2021-11-03 08:16:43

by Austin Kim

Subject: Re: [PATCH] cachefiles: remove always false 'datalen < 0' expression

2021년 8월 24일 (화) 오후 12:18, Austin Kim <[email protected]>님이 작성:
>
> From: Austin Kim <[email protected]>
>
> Since 'datalen' is declared as size_t, the 'datalen < 0' expression
> is always false. Where size_t is defined as below;
>
> typedef unsigned long __kernel_ulong_t;
> typedef __kernel_ulong_t __kernel_size_t;
> typedef __kernel_size_t size_t;
>
> So it had better remove unnecessary 'always false' expression.
>
> Signed-off-by: Austin Kim <[email protected]>
> ---
> fs/cachefiles/daemon.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/cachefiles/daemon.c b/fs/cachefiles/daemon.c
> index 752c1e43416f..1cfed9e0812a 100644
> --- a/fs/cachefiles/daemon.c
> +++ b/fs/cachefiles/daemon.c
> @@ -225,7 +225,7 @@ static ssize_t cachefiles_daemon_write(struct file *file,
> if (test_bit(CACHEFILES_DEAD, &cache->flags))
> return -EIO;
>
> - if (datalen < 0 || datalen > PAGE_SIZE - 1)
> + if (datalen > PAGE_SIZE - 1)
> return -EOPNOTSUPP;
>
> /* drag the command string into the kernel so we can parse it */
> --
> 2.20.1
>

If you are available, would you please review this patch?
It will not take long.

BR,
Austin Kim