Re: [PATCH 1/1] acpi:apei:handle GSIV and GPIO notification types

[James Morse <james.morse@arm.com>]

On 13/03/17 13:16, Shiju Jose wrote:
> System Controller Interrupts are received by ACPI's error device,
> which in turn notifies the GHES code. The same is true of
> APEI's GSIV and GPIO notification types.
> Add support for GSIV and GPIO sharing the SCI
> register/unregister/notifier code.Rename the list and notifier
> to show this is no longer just SCI, but anything from the
> Hardware Error Device.

Reviewed-by: James Morse <james.morse@arm.com>


... what looks like an existing bug:

> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
> index b192b42..fd39929 100644
> --- a/drivers/acpi/apei/ghes.c
> +++ b/drivers/acpi/apei/ghes.c
> @@ -1068,10 +1072,12 @@ static int ghes_remove(struct platform_device *ghes_dev)
>  		free_irq(ghes->irq, ghes);
>  		break;
>  	case ACPI_HEST_NOTIFY_SCI:
> +	case ACPI_HEST_NOTIFY_GSIV:
> +	case ACPI_HEST_NOTIFY_GPIO:
>  		mutex_lock(&ghes_list_mutex);

>  		list_del_rcu(&ghes->list);

Suspiciously, there is no synchronize_rcu() between this list_del_rcu() and the
kfree(ghes) at the bottom of the function. It looks like 81e88fdc432a lifted it
into the NOTIFY_NMI path. I will send a separate fix.


> -		if (list_empty(&ghes_sci))
> -			unregister_acpi_hed_notifier(&ghes_notifier_sci);
> +		if (list_empty(&ghes_hed))
> +			unregister_acpi_hed_notifier(&ghes_notifier_hed);
>  		mutex_unlock(&ghes_list_mutex);
>  		break;
>  	case ACPI_HEST_NOTIFY_NMI:
> 


Thanks,

James