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Date:   Wed, 21 Dec 2022 09:14:35 -0500
From:   Steven Rostedt <rostedt@goodmis.org>
To:     Ricardo Ribalda <ribalda@chromium.org>
Cc:     Jonathan Corbet <corbet@lwn.net>, Philipp Rudo <prudo@redhat.com>,
        Eric Biederman <ebiederm@xmission.com>,
        "Guilherme G. Piccoli" <gpiccoli@igalia.com>,
        kexec@lists.infradead.org, Ross Zwisler <zwisler@kernel.org>,
        "Joel Fernandes (Google)" <joel@joelfernandes.org>,
        Sergey Senozhatsky <senozhatsky@chromium.org>,
        linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org
Subject: Re: [PATCH v4 3/3] kexec: Introduce sysctl parameters
 kexec_load_limit_*
Message-ID: <20221221091435.5ed368cb@gandalf.local.home>
In-Reply-To: <20221114-disable-kexec-reset-v4-3-ab809c8d988c@chromium.org>
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        <20221114-disable-kexec-reset-v4-3-ab809c8d988c@chromium.org>
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On Wed, 21 Dec 2022 13:50:03 +0100
Ricardo Ribalda <ribalda@chromium.org> wrote:

> @@ -941,6 +995,20 @@ static struct ctl_table kexec_core_sysctls[] = {
>  		.extra1		= SYSCTL_ONE,
>  		.extra2		= SYSCTL_ONE,
>  	},
> +	{
> +		.procname	= "kexec_load_limit_panic",
> +		.data		= &load_limit_panic,
> +		.maxlen		= sizeof(load_limit_panic),

If I understand the sysctl logic correctly, the .maxlen is the maxlen of
the input to the sysctl, and not the data. Usually set to sizeof(data)
because most proc_handlers write to data directly.

In this case, I believe it's not even used (you override it with the
struct ctl_table tmp). I guess it doesn't really matter what it's set to.
Perhaps just set it to zero and leave it out?

> +		.mode		= 0644,
> +		.proc_handler	= kexec_limit_handler,
> +	},
> +	{
> +		.procname	= "kexec_load_limit_reboot",
> +		.data		= &load_limit_reboot,
> +		.maxlen		= sizeof(load_limit_reboot),

Same here.

-- Steve

> +		.mode		= 0644,
> +		.proc_handler	= kexec_limit_handler,
> +	},
>  	{ }
>  };
>