Re: [PATCH 3/3] coresight: ultrasoc-smb: fix uninitialized before use buf_hw_base

[hejunhao]

On 2023/10/19 10:34, Yicong Yang wrote:
> On 2023/10/12 17:47, Junhao He wrote:
> > In smb_reset_buffer, the sdb->buf_hw_base variable is uninitialized
> > before use, which initializes it in smb_init_data_buffer. And the SMB
> > regiester are set in smb_config_inport.
> > So move the call after smb_config_inport.
> >
> > Fixes: 06f5c2926aaa ("drivers/coresight: Add UltraSoc System Memory Buffer driver")
> >
> > Signed-off-by: Junhao He <hejunhao3@xxxxxxxxxx>
> > ---
> >   drivers/hwtracing/coresight/ultrasoc-smb.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing/coresight/ultrasoc-smb.c
> > index e78edc3480ce..21ba473786e5 100644
> > --- a/drivers/hwtracing/coresight/ultrasoc-smb.c
> > +++ b/drivers/hwtracing/coresight/ultrasoc-smb.c
> > @@ -475,7 +475,6 @@ static int smb_init_data_buffer(struct platform_device *pdev,
> >   static void smb_init_hw(struct smb_drv_data *drvdata)
> >   {
> >   	smb_disable_hw(drvdata);
> > -	smb_reset_buffer(drvdata);
> >   
> >   	writel(SMB_LB_CFG_LO_DEFAULT, drvdata->base + SMB_LB_CFG_LO_REG);
> >   	writel(SMB_LB_CFG_HI_DEFAULT, drvdata->base + SMB_LB_CFG_HI_REG);
> > @@ -597,6 +596,7 @@ static int smb_probe(struct platform_device *pdev)
> >   	}
> >   
> >   	platform_set_drvdata(pdev, drvdata);
> > +	smb_reset_buffer(drvdata);
> Shouldn't we reset the buffer before registering the sink? Otherwise it'll
> be possible for user to access an unreset one.

Hi Yicong,

Thanks for the comments!

The code after the smb_register_sink() function also needs to moved.
I will fix all in next version.

Best regards,
Junhao.