From: Chen Gang <gang.chen@asianux.com>
To: Thomas Gleixner <tglx@linutronix.de>,
"'Jiri Kosina'" <trivial@kernel.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] kernel/itimer.c: beautify code, not need check 'value', so save one instruction, simpler and easier for readers.
Date: Thu, 20 Jun 2013 20:02:57 +0800 [thread overview]
Message-ID: <51C2EF71.4010308@asianux.com> (raw)
In-Reply-To: <51C2E6F9.80107@asianux.com>
Oh, sorry, maybe it is a trivial patch, also need send to
trivial@kernel.org.
On 06/20/2013 07:26 PM, Chen Gang wrote:
>
> Since copy_to_user() will check 'value', we do not need check it outside
> again, so can save one comparing instruction at least.
>
> Also can let code simpler and easier for readers: if checking parameter
> 'value', it will easily lead readers to think about why not return
> -EINVAL instead of -EFAULT, when checking parameter failed.
>
> Signed-off-by: Chen Gang <gang.chen@asianux.com>
> ---
> kernel/itimer.c | 13 ++++++-------
> 1 files changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/kernel/itimer.c b/kernel/itimer.c
> index 8d262b4..3b12271 100644
> --- a/kernel/itimer.c
> +++ b/kernel/itimer.c
> @@ -102,15 +102,14 @@ int do_getitimer(int which, struct itimerval *value)
>
> SYSCALL_DEFINE2(getitimer, int, which, struct itimerval __user *, value)
> {
> - int error = -EFAULT;
> + int error;
> struct itimerval get_buffer;
>
> - if (value) {
> - error = do_getitimer(which, &get_buffer);
> - if (!error &&
> - copy_to_user(value, &get_buffer, sizeof(get_buffer)))
> - error = -EFAULT;
> - }
> + error = do_getitimer(which, &get_buffer);
> + if (!error &&
> + copy_to_user(value, &get_buffer, sizeof(get_buffer)))
> + error = -EFAULT;
> +
> return error;
> }
>
>
--
Chen Gang
Asianux Corporation
next prev parent reply other threads:[~2013-06-20 12:03 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-20 11:26 [PATCH v2] kernel/itimer.c: beautify code, not need check 'value', so save one instruction, simpler and easier for readers Chen Gang
2013-06-20 12:02 ` Chen Gang [this message]
2013-06-20 12:55 ` Thomas Gleixner
2013-06-21 1:24 ` Chen Gang
2013-06-20 13:42 ` Thomas Gleixner
2013-06-21 2:04 ` Chen Gang
2013-06-21 10:31 ` [PATCH v3] kernel/itimer.c: remove the checking 'value' statement Chen Gang
2013-06-24 23:28 ` [PATCH v2] kernel/itimer.c: beautify code, not need check 'value', so save one instruction, simpler and easier for readers.t Thomas Gleixner
2013-06-25 0:58 ` Chen Gang
2013-06-25 1:16 ` [PATH v4] itimers: Remove bogus NULL pointer check in sys_getitimer() Chen Gang
2013-07-05 1:28 ` Chen Gang
2013-07-22 2:45 ` Chen Gang
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