Re: [PATCH] [SCSI] mvsas: Fix the kernel panic due to unaligned data access

[Paul Guo <ggang@tilera.com>]

Ping. Anyone who knows the driver please speak up, either yes or no
or need more info. This is a really small fix.

Thanks,
Paul

> It's easy to find the address and symbol that causes the unalignd data
> access according to the stack dump information. The following small
> patch will fix it.
> 
> This change is harmless for platforms (like x86/x64) which support
> unaligned data access but is critical for platforms those do not support
> unaligned data access (like our platform: arch/tile).
> 
> I sent the patch but did not ping the status. I sync-up the workspace
> and re-generate the patch again. Feel free to give me any feedback. It's
> really annoying to maintain the change internally.
> 
> Thanks,
> Paul
> 
> 
> Signed-off-by: Paul Guo <ggang@tilera.com>
> ---
>  drivers/scsi/mvsas/mv_sas.c |    5 +++--
>  drivers/scsi/mvsas/mv_sas.h |    1 +
>  2 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/scsi/mvsas/mv_sas.c b/drivers/scsi/mvsas/mv_sas.c
> index fd3b283..18e133e 100644
> --- a/drivers/scsi/mvsas/mv_sas.c
> +++ b/drivers/scsi/mvsas/mv_sas.c
> @@ -1852,10 +1852,11 @@ int mvs_slot_complete(struct mvs_info *mvi, u32 rx_desc, u32 flags)
>  	}
>  
>  	/* error info record present */
> -	if (unlikely((rx_desc & RXQ_ERR) && (*(u64 *) slot->response))) {
> +	if (unlikely((rx_desc & RXQ_ERR) &&
> +		      get_unaligned_le64((u64 *) slot->response))) {
>  		mv_dprintk("port %d slot %d rx_desc %X has error info"
>  			"%016llX.\n", slot->port->sas_port.id, slot_idx,
> -			 rx_desc, (u64)(*(u64 *)slot->response));
> +			 rx_desc, get_unaligned_le64((u64 *) slot->response));
>  		tstat->stat = mvs_slot_err(mvi, task, slot_idx);
>  		tstat->resp = SAS_TASK_COMPLETE;
>  		goto out;
> diff --git a/drivers/scsi/mvsas/mv_sas.h b/drivers/scsi/mvsas/mv_sas.h
> index c04a4f5..c89c145 100644
> --- a/drivers/scsi/mvsas/mv_sas.h
> +++ b/drivers/scsi/mvsas/mv_sas.h
> @@ -39,6 +39,7 @@
>  #include <linux/irq.h>
>  #include <linux/slab.h>
>  #include <linux/vmalloc.h>
> +#include <linux/unaligned.h>
>  #include <scsi/libsas.h>
>  #include <scsi/scsi.h>
>  #include <scsi/scsi_tcq.h>
>