[PATCH RESEND v2] coresight: etm4x: Fix mis-usage of nr_resource in sysfs interface

[Mathieu Poirier]

On Tue, Sep 15, 2020 at 10:53:57AM +0800, Jonathan Zhou wrote:
> The member @nr_resource represents how many resource selector pairs,
> and the pair 0 is always implemented and reserved.
> So let's multiply by 2 when resetting the seletor configuration.
> And also update the validation of the input @idx.
> 
> Cc: Mathieu Poirier <mathieu.poirier at linaro.org>
> Cc: Suzuki K Poulose <suzuki.poulose at arm.com>
> Cc: Mike Leach <mike.leach at linaro.org>
> Cc: Shaokun Zhang <zhangshaokun at hisilicon.com>
> Cc: lizixian at hisilicon.com
> Signed-off-by: Jonathan Zhou <jonathan.zhouwen at huawei.com>
> ---
> ChangeLog in v2:
>     * Address Mathieu's comments.
> 
>  drivers/hwtracing/coresight/coresight-etm4x-sysfs.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)

You send me two identical patches on the same day - the only difference was the
RESEND had an capital 'f' in "Fix".  That's the one I applied.

Thanks,
Mathieu


> 
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> index b673e738bc9a..e4f1f659000d 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> @@ -236,7 +236,7 @@ static ssize_t reset_store(struct device *dev,
>  	}
>  
>  	config->res_idx = 0x0;
> -	for (i = 0; i < drvdata->nr_resource; i++)
> +	for (i = 2; i < 2 * drvdata->nr_resource; i++)
>  		config->res_ctrl[i] = 0x0;
>  
>  	config->ss_idx = 0x0;
> @@ -1663,8 +1663,11 @@ static ssize_t res_idx_store(struct device *dev,
>  
>  	if (kstrtoul(buf, 16, &val))
>  		return -EINVAL;
> -	/* Resource selector pair 0 is always implemented and reserved */
> -	if ((val == 0) || (val >= drvdata->nr_resource))
> +	/*
> +	 * Resource selector pair 0 is always implemented and reserved,
> +	 * namely an idx with 0 and 1 is illegal.
> +	 */
> +	if ((val < 2) || (val >= 2 * drvdata->nr_resource))
>  		return -EINVAL;
>  
>  	/*
> -- 
> 1.9.1
>