Subject: Re: [net PATCH 1/7] octeontx2-af: Secure APR table update with the lock

From: Leon Romanovsky <[email-masked]>
Date: Thu, 30 Mar 2023 08:55:32 +0300

On Wed, Mar 29, 2023 at 10:36:13PM +0530, Sai Krishna wrote:
> From: Geetha sowjanya <[email-masked]>
> 
> APR table contains the lmtst base address of PF/VFs.
> These entries are updated by the PF/VF during the
> device probe. Due to race condition while updating the
> entries are getting corrupted. Hence secure the APR
> table update with the lock.

However, I don't see rsrc_lock in probe path.
otx2_probe()
 -> cn10k_lmtst_init()
  -> lmt_base/lmstst is updated with and without mbox.lock.

Where did you take rsrc_lock in probe flow?

Thanks

> 
> Fixes: 893ae97214c3 ("octeontx2-af: cn10k: Support configurable LMTST regions")
> Signed-off-by: Geetha sowjanya <[email-masked]>
> Signed-off-by: Sunil Kovvuri Goutham <[email-masked]>
> Signed-off-by: Sai Krishna <[email-masked]>
> ---
>  drivers/net/ethernet/marvell/octeontx2/af/rvu_cn10k.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/ethernet/marvell/octeontx2/af/rvu_cn10k.c b/drivers/net/ethernet/marvell/octeontx2/af/rvu_cn10k.c
> index 4ad9ff025c96..8530250f6fba 100644
> --- a/drivers/net/ethernet/marvell/octeontx2/af/rvu_cn10k.c
> +++ b/drivers/net/ethernet/marvell/octeontx2/af/rvu_cn10k.c
> @@ -142,16 +142,17 @@ int rvu_mbox_handler_lmtst_tbl_setup(struct rvu *rvu,
>  	 * region, if so, convert that IOVA to physical address and
>  	 * populate LMT table with that address
>  	 */
> +	mutex_lock(&rvu->rsrc_lock);
>  	if (req->use_local_lmt_region) {
>  		err = rvu_get_lmtaddr(rvu, req->hdr.pcifunc,
>  				      req->lmt_iova, &lmt_addr);
>  		if (err < 0)
> -			return err;
> +			goto error;
>  
>  		/* Update the lmt addr for this PFFUNC in the LMT table */
>  		err = rvu_update_lmtaddr(rvu, req->hdr.pcifunc, lmt_addr);
>  		if (err)
> -			return err;
> +			goto error;
>  	}
>  
>  	/* Reconfiguring lmtst map table in lmt region shared mode i.e. make
> @@ -181,7 +182,7 @@ int rvu_mbox_handler_lmtst_tbl_setup(struct rvu *rvu,
>  		 */
>  		err = rvu_update_lmtaddr(rvu, req->hdr.pcifunc, val);
>  		if (err)
> -			return err;
> +			goto error;
>  	}
>  
>  	/* This mailbox can also be used to update word1 of APR_LMT_MAP_ENTRY_S
> @@ -230,6 +231,7 @@ int rvu_mbox_handler_lmtst_tbl_setup(struct rvu *rvu,
>  	}
>  
>  error:
> +	mutex_unlock(&rvu->rsrc_lock);
>  	return err;
>  }
>  
> -- 
> 2.25.1
>