From: Andrew Morton <akpm@linux-foundation.org>
To: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
Cc: <gorcunov@gmail.com>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] sys_prctl(): remove unsigned comparision with less than zero
Date: Wed, 24 Jul 2019 19:14:48 -0700 [thread overview]
Message-ID: <20190724191448.4db70a34f8b89bd8bdc085f5@linux-foundation.org> (raw)
In-Reply-To: <1563934308-20833-1-git-send-email-xuyang2018.jy@cn.fujitsu.com>
On Wed, 24 Jul 2019 10:11:48 +0800 Yang Xu <xuyang2018.jy@cn.fujitsu.com> wrote:
> Currently, when calling prctl(PR_SET_TIMERSLACK, arg2), arg2 is an
> unsigned long value, arg2 will never < 0. Negative judgment is
> meaningless, so remove it.
>
> ...
>
> --- a/kernel/sys.c
> +++ b/kernel/sys.c
> @@ -2372,7 +2372,7 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
> error = current->timer_slack_ns;
> break;
> case PR_SET_TIMERSLACK:
> - if (arg2 <= 0)
> + if (arg2 == 0)
> current->timer_slack_ns =
> current->default_timer_slack_ns;
A number of years ago Linus expressed approval of such comparisons with
unsigned quantities. He felt that it improves readability a little -
the reader doesn't have to scroll back and check the type.
next prev parent reply other threads:[~2019-07-25 2:14 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-23 3:30 [PATCH] sys_prctl(): simplify arg2 judgment when calling PR_SET_TIMERSLACK Yang Xu
2019-07-23 7:23 ` Cyrill Gorcunov
2019-07-23 8:11 ` Yang Xu
2019-07-23 9:48 ` Cyrill Gorcunov
2019-07-24 2:11 ` [PATCH v2] sys_prctl(): remove unsigned comparision with less than zero Yang Xu
2019-07-24 6:56 ` Cyrill Gorcunov
2019-07-25 2:14 ` Andrew Morton [this message]
2019-07-25 3:10 ` Yang Xu
2019-07-30 8:48 ` Yang Xu
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