Messages in this thread | | | Date | Wed, 24 Jul 2019 19:14:48 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH v2] sys_prctl(): remove unsigned comparision with less than zero |
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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.
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