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

Paul Menzel
2021-07-07T07:48:10Z

Dear Don, dear Mike,

Am 06.07.21 um 20:16 schrieb Don Brace:
> From: Mike McGowen <mike.mcgowen@microchip.com>
>
> 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@microchip.com>
> Reviewed-by: Scott Benesh <scott.benesh@microchip.com>
> Reviewed-by: Scott Teel <scott.teel@microchip.com>
> Signed-off-by: Mike McGowen <mike.mcgowen@microchip.com>
> Signed-off-by: Don Brace <don.brace@microchip.com>
> ---
> 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