Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20200910211344.3562-1-colomar.6.4.3@gmail.com> <20200910211344.3562-13-colomar.6.4.3@gmail.com>
In-Reply-To: <20200910211344.3562-13-colomar.6.4.3@gmail.com>
From:   Stefan Puiu <stefan.puiu@gmail.com>
Date:   Fri, 11 Sep 2020 17:35:28 +0300
Message-ID: <CACKs7VD_p=d+nvuFxkWofSE6jCoKAKx5w44_5ciTJ0NX_H1ZFA@mail.gmail.com>
Subject: Re: [PATCH 12/24] getgrent_r.3: Use sizeof() to get buffer size
 (instead of hardcoding macro name)
To:     Alejandro Colomar <colomar.6.4.3@gmail.com>
Cc:     Michael Kerrisk <mtk.manpages@gmail.com>,
        lnx-man <linux-man@vger.kernel.org>, linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hi,

On Fri, Sep 11, 2020 at 12:15 AM Alejandro Colomar
<colomar.6.4.3@gmail.com> wrote:
>
> Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
> ---
>  man3/getgrent_r.3 | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/man3/getgrent_r.3 b/man3/getgrent_r.3
> index 81d81a851..76deec370 100644
> --- a/man3/getgrent_r.3
> +++ b/man3/getgrent_r.3
> @@ -186,7 +186,7 @@ main(void)
>
>      setgrent();
>      while (1) {
> -        i = getgrent_r(&grp, buf, BUFLEN, &grpp);
> +        i = getgrent_r(&grp, buf, sizeof(buf), &grpp);

I'm worried that less attentive people might copy/paste parts of this
in their code, where maybe buf is just a pointer, and expect it to
work. Maybe leaving BUFLEN here is useful as a reminder that they need
to change something to adapt the code?

Just my 2 cents,
Stefan.