Re: [PATCH v2 3/6] soc: hisilicon: kunpeng_hccs: Add the check for base address and size of shared memory

[lihuisong (C)]

在 2024/8/23 16:38, Jonathan Cameron 写道:
> On Fri, 23 Aug 2024 11:10:56 +0800
> Huisong Li <lihuisong@xxxxxxxxxx> wrote:
>
> > If the shmem_base_addr from PCCT is zero, hccs_register_pcc_channel will
> > return success. And then driver will access to illegal address when send
> > PCC command. In addition, the size of shared memory used for communication
> > between driver and platform is fixed, namely 64 Bytes which is
> > unchangeable. So add the verification for them.
> As with previous, make it clear if this hardening or fix
> fix to catch a problem on shipping hardware (I assume not, but you never
> know!)
Ack
> A comment on existing code inline.  Not a suggestion for a change
> in this series, but maybe for the future.  There are a lot
> of goto err_mbx_channel_Free in here already and this patch adds
> another.  The cleanup there is trivial so DEFINE_FREE() and __free
> usage will make this code quite a bit nicer to read.
Yeah, it's a good way to simplify code on error path.
I will take into account it. thanks for your good suggestion.
> > Signed-off-by: Huisong Li <lihuisong@xxxxxxxxxx>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
>
> > ---
> >   drivers/soc/hisilicon/kunpeng_hccs.c | 24 +++++++++++++++---------
> >   1 file changed, 15 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/soc/hisilicon/kunpeng_hccs.c b/drivers/soc/hisilicon/kunpeng_hccs.c
> > index 6e88f597f267..6055e5091cbd 100644
> > --- a/drivers/soc/hisilicon/kunpeng_hccs.c
> > +++ b/drivers/soc/hisilicon/kunpeng_hccs.c
> > @@ -170,15 +170,21 @@ static int hccs_register_pcc_channel(struct hccs_dev *hdev)
> >   		goto err_mbx_channel_free;
> >   	}
> >   
> > -	if (pcc_chan->shmem_base_addr) {
> > -		cl_info->pcc_comm_addr = ioremap(pcc_chan->shmem_base_addr,
> > -						 pcc_chan->shmem_size);
> > -		if (!cl_info->pcc_comm_addr) {
> > -			dev_err(dev, "Failed to ioremap PCC communication region for channel-%u.\n",
> > -				hdev->chan_id);
> > -			rc = -ENOMEM;
> > -			goto err_mbx_channel_free;
> > -		}
> > +	if (!pcc_chan->shmem_base_addr ||
> > +	    pcc_chan->shmem_size != HCCS_PCC_SHARE_MEM_BYTES) {
> > +		dev_err(dev, "The base address or size (%llu) of PCC communication region is invalid.\n",
> > +			pcc_chan->shmem_size);
> > +		rc = -EINVAL;
> > +		goto err_mbx_channel_free;
> Worth considering for the future: Maybe a DEFINE_FREE for pcc_mbox_free_channel) makes sense,
> though if you do you should only assign cl_info->pcc_chan after all possible error paths.
Ack
> > +	}
> > +
> > +	cl_info->pcc_comm_addr = ioremap(pcc_chan->shmem_base_addr,
> > +					 pcc_chan->shmem_size);
> > +	if (!cl_info->pcc_comm_addr) {
> > +		dev_err(dev, "Failed to ioremap PCC communication region for channel-%u.\n",
> > +			hdev->chan_id);
> > +		rc = -ENOMEM;
> > +		goto err_mbx_channel_free;
> >   	}
> >   
> >   	return 0;
> .