Re: [PATCH 4/4] [intel_ips] NULL pointer might be used in ips_monitor()

[Minskey Guo <chaohong_guo@linux.intel.com>]

Hi,

         Ping,  any comment for the patches ?


thanks,
-minskey

On 09/17/2010 02:03 PM, minskey guo wrote:
>   The patch is to create ips_adjust thread before ips_monitor begins
>   to run  because the latter will kthread_stop() or wake up the former
>   via ips->adjust pointer. Without this change, it is possible that
>   ips->adjust is NULL when kthread_stop() or wake_up_process() is
>   called in ips_monitor().
>
> Signed-off-by: minskey guo<chaohong.guo@intel.com>
> Acked-by: Jesse Barnes<jbarnes@virtuousgeek.org>
> ---
>   drivers/platform/x86/intel_ips.c |   22 +++++++++++++---------
>   1 files changed, 13 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/platform/x86/intel_ips.c b/drivers/platform/x86/intel_ips.c
> index 71dcc41..cb59ebd 100644
> --- a/drivers/platform/x86/intel_ips.c
> +++ b/drivers/platform/x86/intel_ips.c
> @@ -940,7 +940,6 @@ static int ips_monitor(void *data)
>   		kfree(mch_samples);
>   		kfree(cpu_samples);
>   		kfree(mchp_samples);
> -		kthread_stop(ips->adjust);
>   		return -ENOMEM;
>   	}
>
> @@ -1535,19 +1534,24 @@ static int ips_probe(struct pci_dev *dev, const struct pci_device_id *id)
>   	ips_enable_cpu_turbo(ips);
>   	ips->cpu_turbo_enabled = true;
>
> -	/* Set up the work queue and monitor/adjust threads */
> -	ips->monitor = kthread_run(ips_monitor, ips, "ips-monitor");
> -	if (IS_ERR(ips->monitor)) {
> +	/* Create thermal adjust thread */
> +	ips->adjust = kthread_create(ips_adjust, ips, "ips-adjust");
> +	if (IS_ERR(ips->adjust)) {
>   		dev_err(&dev->dev,
> -			"failed to create thermal monitor thread, aborting\n");
> +			"failed to create thermal adjust thread, aborting\n");
>   		ret = -ENOMEM;
>   		goto error_free_irq;
> +
>   	}
>
> -	ips->adjust = kthread_create(ips_adjust, ips, "ips-adjust");
> -	if (IS_ERR(ips->adjust)) {
> +	/*
> +	 * Set up the work queue and monitor thread. The monitor thread
> +	 * will wake up ips_adjust thread.
> +	 */
> +	ips->monitor = kthread_run(ips_monitor, ips, "ips-monitor");
> +	if (IS_ERR(ips->monitor)) {
>   		dev_err(&dev->dev,
> -			"failed to create thermal adjust thread, aborting\n");
> +			"failed to create thermal monitor thread, aborting\n");
>   		ret = -ENOMEM;
>   		goto error_thread_cleanup;
>   	}
> @@ -1566,7 +1570,7 @@ static int ips_probe(struct pci_dev *dev, const struct pci_device_id *id)
>   	return ret;
>
>   error_thread_cleanup:
> -	kthread_stop(ips->monitor);
> +	kthread_stop(ips->adjust);
>   error_free_irq:
>   	free_irq(ips->dev->irq, ips);
>   error_unmap:
>