Re: [External] [PATCH] ACPI / EC: Mark the ec_sys write_support param as module_param_hw()

From: Mark Pearson <markpearson@lenovo.com>
To: Hans de Goede <hdegoede@redhat.com>,
	"Rafael J . Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>, <linux-acpi@vger.kernel.org>
Subject: Re: [External] [PATCH] ACPI / EC: Mark the ec_sys write_support param as module_param_hw()
Date: Wed, 1 Dec 2021 09:06:00 -0500	[thread overview]
Message-ID: <6990b275-9a09-a135-8e9b-d5c963040770@lenovo.com> (raw)
In-Reply-To: <20211125103616.47742-1-hdegoede@redhat.com>


On 2021-11-25 05:36, Hans de Goede wrote:
> Using write_support=1 with the ec_sys module changes the mode of the
> "io" debugfs file to 0600. This will cause any attempts to access it under
> a kernel in lockdown mode to return -EPERM, which makes the entire ec_sys
> module unusable.
> 
> Use the special module_param_hw() macro for module parameters which
> may not be used while in lockdown mode, to avoid this.
> 
> Cc: Mark Pearson <markpearson@lenovo.com>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  drivers/acpi/ec_sys.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/acpi/ec_sys.c b/drivers/acpi/ec_sys.c
> index fd39c14493ab..c074a0fae059 100644
> --- a/drivers/acpi/ec_sys.c
> +++ b/drivers/acpi/ec_sys.c
> @@ -19,7 +19,7 @@ MODULE_DESCRIPTION("ACPI EC sysfs access driver");
>  MODULE_LICENSE("GPL");
>  
>  static bool write_support;
> -module_param(write_support, bool, 0644);
> +module_param_hw(write_support, bool, other, 0644);
>  MODULE_PARM_DESC(write_support, "Dangerous, reboot and removal of battery may "
>  		 "be needed.");
>  
> 
Looks good to me. Thanks Hans
Mark