linux-kernel - Re: [PATCH 18/22] Input: powermate - use guard notation when acquiring spinlock

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <f2bc481b-8560-40b4-88a1-5517c21f5630@gmail.com>
Date: Wed, 4 Sep 2024 21:16:20 +0200
From: Javier Carrasco <javier.carrasco.cruz@...il.com>
To: Dmitry Torokhov <dmitry.torokhov@...il.com>, linux-input@...r.kernel.org
Cc: Michael Hennerich <michael.hennerich@...log.com>,
 Ville Syrjala <syrjala@....fi>,
 Support Opensource <support.opensource@...semi.com>,
 Eddie James <eajames@...ux.ibm.com>, Andrey Moiseev <o2g.org.ru@...il.com>,
 Hans de Goede <hdegoede@...hat.com>, Jeff LaBundy <jeff@...undy.com>,
 linux-kernel@...r.kernel.org,
 Javier Carrasco Cruz <javier.carrasco.cruz@...il.com>
Subject: Re: [PATCH 18/22] Input: powermate - use guard notation when
 acquiring spinlock

On 04/09/2024 06:49, Dmitry Torokhov wrote:
> Using guard notation makes the code more compact and error handling
> more robust by ensuring that locks are released in all code paths
> when control leaves critical section.
> 
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
> ---
>  drivers/input/misc/powermate.c | 11 ++---------
>  1 file changed, 2 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/input/misc/powermate.c b/drivers/input/misc/powermate.c
> index 4b039abffc4b..ecb92ee5ebbc 100644
> --- a/drivers/input/misc/powermate.c
> +++ b/drivers/input/misc/powermate.c
> @@ -194,22 +194,18 @@ static void powermate_sync_state(struct powermate_device *pm)
>  static void powermate_config_complete(struct urb *urb)
>  {
>  	struct powermate_device *pm = urb->context;
> -	unsigned long flags;
>  
>  	if (urb->status)
>  		printk(KERN_ERR "powermate: config urb returned %d\n", urb->status);
>  
> -	spin_lock_irqsave(&pm->lock, flags);
> +	guard(spinlock_irqsave)(&pm->lock);
>  	powermate_sync_state(pm);
> -	spin_unlock_irqrestore(&pm->lock, flags);
>  }
>  
>  /* Set the LED up as described and begin the sync with the hardware if required */
>  static void powermate_pulse_led(struct powermate_device *pm, int static_brightness, int pulse_speed,
>  				int pulse_table, int pulse_asleep, int pulse_awake)
>  {
> -	unsigned long flags;
> -
>  	if (pulse_speed < 0)
>  		pulse_speed = 0;
>  	if (pulse_table < 0)
> @@ -222,8 +218,7 @@ static void powermate_pulse_led(struct powermate_device *pm, int static_brightne
>  	pulse_asleep = !!pulse_asleep;
>  	pulse_awake = !!pulse_awake;
>  
> -
> -	spin_lock_irqsave(&pm->lock, flags);
> +	guard(spinlock_irqsave)(&pm->lock);
>  
>  	/* mark state updates which are required */
>  	if (static_brightness != pm->static_brightness) {
> @@ -245,8 +240,6 @@ static void powermate_pulse_led(struct powermate_device *pm, int static_brightne
>  	}
>  
>  	powermate_sync_state(pm);
> -
> -	spin_unlock_irqrestore(&pm->lock, flags);
>  }
>  
>  /* Callback from the Input layer when an event arrives from userspace to configure the LED */

Reviewed-by: Javier Carrasco <javier.carrasco.cruz@...il.com>