linux-kernel - Re: [PATCH v4 1/2] i2c: designware: Add missing locks

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]

Date:   Wed, 9 Feb 2022 17:23:05 +0200
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Jan Dabros <jsd@...ihalf.com>
Cc:     linux-kernel@...r.kernel.org, linux-i2c@...r.kernel.org,
        jarkko.nikula@...ux.intel.com, mika.westerberg@...ux.intel.com,
        hdegoede@...hat.com, wsa@...nel.org, rrangel@...omium.org,
        mw@...ihalf.com, jaz@...ihalf.com, upstream@...ihalf.com,
        thomas.lendacky@....com, alexander.deucher@....com,
        Nimesh.Easow@....com, mario.limonciello@....com
Subject: Re: [PATCH v4 1/2] i2c: designware: Add missing locks

On Tue, Feb 08, 2022 at 03:12:17PM +0100, Jan Dabros wrote:
> All accesses to controller's registers should be protected on
> probe, disable and xfer paths. This is needed for i2c bus controllers
> that are shared with but not controller by kernel.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>

> Signed-off-by: Jan Dabros <jsd@...ihalf.com>
> Reviewed-by: Hans de Goede <hdegoede@...hat.com>
> ---
>  drivers/i2c/busses/i2c-designware-common.c | 12 ++++++++++++
>  drivers/i2c/busses/i2c-designware-master.c |  6 ++++++
>  2 files changed, 18 insertions(+)
> 
> diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c
> index bf2a4920638a..9f8574320eb2 100644
> --- a/drivers/i2c/busses/i2c-designware-common.c
> +++ b/drivers/i2c/busses/i2c-designware-common.c
> @@ -578,7 +578,12 @@ int i2c_dw_set_fifo_size(struct dw_i2c_dev *dev)
>  	 * Try to detect the FIFO depth if not set by interface driver,
>  	 * the depth could be from 2 to 256 from HW spec.
>  	 */
> +	ret = i2c_dw_acquire_lock(dev);
> +	if (ret)
> +		return ret;
> +
>  	ret = regmap_read(dev->map, DW_IC_COMP_PARAM_1, &param);
> +	i2c_dw_release_lock(dev);
>  	if (ret)
>  		return ret;
>  
> @@ -607,6 +612,11 @@ u32 i2c_dw_func(struct i2c_adapter *adap)
>  void i2c_dw_disable(struct dw_i2c_dev *dev)
>  {
>  	u32 dummy;
> +	int ret;
> +
> +	ret = i2c_dw_acquire_lock(dev);
> +	if (ret)
> +		return;
>  
>  	/* Disable controller */
>  	__i2c_dw_disable(dev);
> @@ -614,6 +624,8 @@ void i2c_dw_disable(struct dw_i2c_dev *dev)
>  	/* Disable all interrupts */
>  	regmap_write(dev->map, DW_IC_INTR_MASK, 0);
>  	regmap_read(dev->map, DW_IC_CLR_INTR, &dummy);
> +
> +	i2c_dw_release_lock(dev);
>  }
>  
>  void i2c_dw_disable_int(struct dw_i2c_dev *dev)
> diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
> index 9177463c2cbb..1a4b23556db3 100644
> --- a/drivers/i2c/busses/i2c-designware-master.c
> +++ b/drivers/i2c/busses/i2c-designware-master.c
> @@ -905,7 +905,13 @@ int i2c_dw_probe_master(struct dw_i2c_dev *dev)
>  		irq_flags = IRQF_SHARED | IRQF_COND_SUSPEND;
>  	}
>  
> +	ret = i2c_dw_acquire_lock(dev);
> +	if (ret)
> +		return ret;
> +
>  	i2c_dw_disable_int(dev);
> +	i2c_dw_release_lock(dev);
> +
>  	ret = devm_request_irq(dev->dev, dev->irq, i2c_dw_isr, irq_flags,
>  			       dev_name(dev->dev), dev);
>  	if (ret) {
> -- 
> 2.35.0.263.gb82422642f-goog
> 

-- 
With Best Regards,
Andy Shevchenko