linux-kernel - Re: [PATCH] spi: atmel: fixed spin_lock usage inside atmel_spi

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 for Android: free password hash cracker in your pocket

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

Message-ID: <16338851-85fe-27ab-3da6-7c37212b82b8@microchip.com>
Date:   Tue, 19 Dec 2017 11:23:25 +0100
From:   Nicolas Ferre <nicolas.ferre@...rochip.com>
To:     Radu Pirea <radu.pirea@...rochip.com>, <broonie@...nel.org>,
        <alexandre.belloni@...e-electrons.com>,
        <Wenyou.Yang@...rochip.com>, <baijiaju1990@...il.com>
CC:     <linux-spi@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH] spi: atmel: fixed spin_lock usage inside atmel_spi_remove

On 15/12/2017 at 16:40, Radu Pirea wrote:
> The only part of atmel_spi_remove which needs to be atomic is hardware
> reset.
> 
> atmel_spi_stop_dma calls dma_terminate_all and this needs interrupts
> enabled.
> atmel_spi_release_dma calls dma_release_channel and dma_release_channel
> locks a mutex inside of spin_lock.
> 
> So the call of these functions can't be inside a spin_lock.
> 
> Reported-by: Jia-Ju Bai <baijiaju1990@...il.com>
> Signed-off-by: Radu Pirea <radu.pirea@...rochip.com>

Acked-by: Nicolas Ferre <nicolas.ferre@...rochip.com>

Thanks Radu. Regards,
  Nicolas

> ---
>  drivers/spi/spi-atmel.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
> index f95da36..6694709 100644
> --- a/drivers/spi/spi-atmel.c
> +++ b/drivers/spi/spi-atmel.c
> @@ -1661,12 +1661,12 @@ static int atmel_spi_remove(struct platform_device *pdev)
>  	pm_runtime_get_sync(&pdev->dev);
>  
>  	/* reset the hardware and block queue progress */
> -	spin_lock_irq(&as->lock);
>  	if (as->use_dma) {
>  		atmel_spi_stop_dma(master);
>  		atmel_spi_release_dma(master);
>  	}
>  
> +	spin_lock_irq(&as->lock);
>  	spi_writel(as, CR, SPI_BIT(SWRST));
>  	spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
>  	spi_readl(as, SR);
> 


-- 
Nicolas Ferre