[PATCH] scsi: ufs: Check that space was properly alloced in copy_query_response

[PATCH] scsi: ufs: Check that space was properly alloced in copy_query_response

[Avri Altman]

struct ufs_dev_cmd is the main container that supports device management
commands. In the case of a read descriptor request, we assume that the
proper space was allocated in dev_cmd to hold the returning descriptor.

This is no longer true, as there are flows that doesn't use dev_cmd
for device management requests, and was wrong in the first place.

fixes: d44a5f98bb49 (ufs: query descriptor API)

Signed-off-by: Avri Altman <avri.altman@wdc.com>
---
 drivers/scsi/ufs/ufshcd.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 8c1c551..3fe3029 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -1917,7 +1917,8 @@ int ufshcd_copy_query_response(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 	memcpy(&query_res->upiu_res, &lrbp->ucd_rsp_ptr->qr, QUERY_OSF_SIZE);
 
 	/* Get the descriptor */
-	if (lrbp->ucd_rsp_ptr->qr.opcode == UPIU_QUERY_OPCODE_READ_DESC) {
+	if (hba->dev_cmd.query.descriptor &&
+	    lrbp->ucd_rsp_ptr->qr.opcode == UPIU_QUERY_OPCODE_READ_DESC) {
 		u8 *descp = (u8 *)lrbp->ucd_rsp_ptr +
 				GENERAL_UPIU_REQUEST_SIZE;
 		u16 resp_len;
-- 
1.9.1

Re: [PATCH] scsi: ufs: Check that space was properly alloced in copy_query_response

[Alim Akhtar]

Hi Avri

On 5/21/19 1:54 PM, Avri Altman wrote:
> struct ufs_dev_cmd is the main container that supports device management
> commands. In the case of a read descriptor request, we assume that the
> proper space was allocated in dev_cmd to hold the returning descriptor.
> 
> This is no longer true, as there are flows that doesn't use dev_cmd
> for device management requests, and was wrong in the first place.
> 
Can you please put some light on those flows? Are those platform 
specific? Just curious.
> fixes: d44a5f98bb49 (ufs: query descriptor API)
> 
> Signed-off-by: Avri Altman <avri.altman@wdc.com>
> ---
>   drivers/scsi/ufs/ufshcd.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 8c1c551..3fe3029 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -1917,7 +1917,8 @@ int ufshcd_copy_query_response(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
>   	memcpy(&query_res->upiu_res, &lrbp->ucd_rsp_ptr->qr, QUERY_OSF_SIZE);
>   
>   	/* Get the descriptor */
> -	if (lrbp->ucd_rsp_ptr->qr.opcode == UPIU_QUERY_OPCODE_READ_DESC) {
> +	if (hba->dev_cmd.query.descriptor &&
> +	    lrbp->ucd_rsp_ptr->qr.opcode == UPIU_QUERY_OPCODE_READ_DESC) {
>   		u8 *descp = (u8 *)lrbp->ucd_rsp_ptr +
>   				GENERAL_UPIU_REQUEST_SIZE;
>   		u16 resp_len;
> 
This change looks ok to me. I hope you have tested this patch.
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>

RE: [EXT] [PATCH] scsi: ufs: Check that space was properly alloced in copy_query_response

[Bean Huo (beanhuo)]

Hi, Avri
>
>Signed-off-by: Avri Altman <avri.altman@wdc.com>
Acked-by: Bean Huo <beanhuo@micron.com>

Thanks,
//Bean

RE: [PATCH] scsi: ufs: Check that space was properly alloced in copy_query_response

[Avri Altman]

Hi Alim,
Thank you for your review.
Sorry for the late response - I was away for a couple of weeks.

Thanks,
Avri

> Subject: Re: [PATCH] scsi: ufs: Check that space was properly alloced in
> copy_query_response
> 
> Hi Avri
> 
> On 5/21/19 1:54 PM, Avri Altman wrote:
> > struct ufs_dev_cmd is the main container that supports device management
> > commands. In the case of a read descriptor request, we assume that the
> > proper space was allocated in dev_cmd to hold the returning descriptor.
> >
> > This is no longer true, as there are flows that doesn't use dev_cmd
> > for device management requests, and was wrong in the first place.
> >
> Can you please put some light on those flows? Are those platform
> specific? Just curious.
No, actually its quite simplistic.
__ufshcd_query_descriptor set dev_cmd.query.descriptor 
to point to its designated space before sending the read descriptor query,
and to null once it's done.
But it doesn't check it in ufshcd_copy_query_response when the query
returns from the device, which it should, as I indicated in the commit log.


> This change looks ok to me. I hope you have tested this patch.
Yes I did.

> Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>

Re: [PATCH] scsi: ufs: Check that space was properly alloced in copy_query_response

[Martin K. Petersen]

Avri,

> struct ufs_dev_cmd is the main container that supports device management
> commands. In the case of a read descriptor request, we assume that the
> proper space was allocated in dev_cmd to hold the returning descriptor.
>
> This is no longer true, as there are flows that doesn't use dev_cmd
> for device management requests, and was wrong in the first place.

Applied to 5.2/scsi-fixes, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering