linux-kernel - Re: [PATCH] proc: save 2 atomic ops on write to "/proc/*/attr/*"

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Message-ID: <CAHp75Vcp61v_VeMNrKYwpc7MKXy2Mjcx9kek-oPyX8A+P7ci1w@mail.gmail.com>
Date:   Thu, 28 Jun 2018 00:42:34 +0300
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     Alexey Dobriyan <adobriyan@...il.com>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        linux-security-module <linux-security-module@...r.kernel.org>
Subject: Re: [PATCH] proc: save 2 atomic ops on write to "/proc/*/attr/*"

On Wed, Jun 27, 2018 at 11:02 PM, Alexey Dobriyan <adobriyan@...il.com> wrote:
> Code checks if write is done by current to its own attributes.
> For that get/put pair is unnecessary as it can be done under RCU.

>         /* No partial writes. */
> -       length = -EINVAL;
>         if (*ppos != 0)
> -               goto out;
> +               return -EINVAL;
>
>         page = memdup_user(buf, count);
>         if (IS_ERR(page)) {

> -               length = PTR_ERR(page);
> +               rv = PTR_ERR(page);
>                 goto out;

You alredy have more than one exit location, why not to convert this
one as well and get rid of out label completely?

>         }

>  out_free:
>         kfree(page);
>  out:

> +       return rv;
>  }

-- 
With Best Regards,
Andy Shevchenko