Re: [smartpqi updates PATCH 8/9] smartpqi: fix isr accessing null structure member

[Paul Menzel]

Dear Don, dear Mike,


Am 06.07.21 um 20:16 schrieb Don Brace:
> From: Mike McGowen <mike.mcgowen@xxxxxxxxxxxxx>
>
> Correct driver's ISR accessing a data structure member
> that has not been fully initialized during driver init.

Does that crash the Linux kernel?

>    - The pqi queue groups can be null when an interrupt fires.

If it fixes a crash(?), please add a Fixes: tag so it can be backported 
to the stable series.

> Reviewed-by: Kevin Barnett <kevin.barnett@xxxxxxxxxxxxx>
> Reviewed-by: Scott Benesh <scott.benesh@xxxxxxxxxxxxx>
> Reviewed-by: Scott Teel <scott.teel@xxxxxxxxxxxxx>
> Signed-off-by: Mike McGowen <mike.mcgowen@xxxxxxxxxxxxx>
> Signed-off-by: Don Brace <don.brace@xxxxxxxxxxxxx>
> ---
>   drivers/scsi/smartpqi/smartpqi_init.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c
> index 6f2263abaa8c..eeaf0568b5e3 100644
> --- a/drivers/scsi/smartpqi/smartpqi_init.c
> +++ b/drivers/scsi/smartpqi/smartpqi_init.c
> @@ -7757,11 +7757,11 @@ static int pqi_ctrl_init(struct pqi_ctrl_info *ctrl_info)
>   
>   	pqi_init_operational_queues(ctrl_info);
>   
> -	rc = pqi_request_irqs(ctrl_info);
> +	rc = pqi_create_queues(ctrl_info);

From a quick look, these two functions are quite different. It’d be 
great if you elaborated a bit in the commit message, what else the new 
function does.

Also, with this change, `pqi_request_irqs()` does not seem to have any 
users anymore. Without your patch:

    $ git grep pqi_request_irqs
    drivers/scsi/smartpqi/smartpqi_init.c:static int 
pqi_request_irqs(struct pqi_ctrl_info *ctrl_info)
    drivers/scsi/smartpqi/smartpqi_init.c:  rc = 
pqi_request_irqs(ctrl_info);

>   	if (rc)
>   		return rc;
>   
> -	rc = pqi_create_queues(ctrl_info);
> +	rc = pqi_request_irqs(ctrl_info);
>   	if (rc)
>   		return rc;


Kind regards,

Paul