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* [PATCH 1/1] i3c: master: svc: return error when read length bigger than 255
@ 2024-01-10 22:25 Frank Li
  2024-01-11  0:15 ` Alexandre Belloni
  0 siblings, 1 reply; 3+ messages in thread
From: Frank Li @ 2024-01-10 22:25 UTC (permalink / raw)
  To: frank.li
  Cc: alexandre.belloni, conor.culhane, imx, joe, linux-i3c,
	linux-kernel, miquel.raynal, zbigniew.lukwinski

RDTERM in MCTRL is 8 bits. Add a length check to prevent silent data errors
when the read length exceeds 255 bytes during each i3c_priv_xfer operation.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/i3c/master/svc-i3c-master.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index bd10bb698da0f..181b56953fb28 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -1375,6 +1375,11 @@ static int svc_i3c_master_priv_xfers(struct i3c_dev_desc *dev,
 		cmd->len = xfers[i].len;
 		cmd->actual_len = xfers[i].rnw ? xfers[i].len : 0;
 		cmd->continued = (i + 1) < nxfers;
+
+		if (cmd->rnw && cmd->len > 255) {
+			dev_err(master->dev, "only support read less than 255 each xfer\n");
+			return -EINVAL;
+		}
 	}
 
 	mutex_lock(&master->lock);
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH 1/1] i3c: master: svc: return error when read length bigger than 255
  2024-01-10 22:25 [PATCH 1/1] i3c: master: svc: return error when read length bigger than 255 Frank Li
@ 2024-01-11  0:15 ` Alexandre Belloni
  2024-01-11 17:29   ` Frank Li
  0 siblings, 1 reply; 3+ messages in thread
From: Alexandre Belloni @ 2024-01-11  0:15 UTC (permalink / raw)
  To: Frank Li
  Cc: conor.culhane, imx, joe, linux-i3c, linux-kernel, miquel.raynal,
	zbigniew.lukwinski

On 10/01/2024 17:25:03-0500, Frank Li wrote:
> RDTERM in MCTRL is 8 bits. Add a length check to prevent silent data errors
> when the read length exceeds 255 bytes during each i3c_priv_xfer operation.
> 
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
>  drivers/i3c/master/svc-i3c-master.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
> index bd10bb698da0f..181b56953fb28 100644
> --- a/drivers/i3c/master/svc-i3c-master.c
> +++ b/drivers/i3c/master/svc-i3c-master.c
> @@ -1375,6 +1375,11 @@ static int svc_i3c_master_priv_xfers(struct i3c_dev_desc *dev,
>  		cmd->len = xfers[i].len;
>  		cmd->actual_len = xfers[i].rnw ? xfers[i].len : 0;
>  		cmd->continued = (i + 1) < nxfers;
> +
> +		if (cmd->rnw && cmd->len > 255) {
> +			dev_err(master->dev, "only support read less than 255 each xfer\n");

What would be the end user action upon seeing this message? Is it actually
useful?

> +			return -EINVAL;
> +		}
>  	}
>  
>  	mutex_lock(&master->lock);
> -- 
> 2.34.1
> 

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH 1/1] i3c: master: svc: return error when read length bigger than 255
  2024-01-11  0:15 ` Alexandre Belloni
@ 2024-01-11 17:29   ` Frank Li
  0 siblings, 0 replies; 3+ messages in thread
From: Frank Li @ 2024-01-11 17:29 UTC (permalink / raw)
  To: Alexandre Belloni
  Cc: conor.culhane, imx, joe, linux-i3c, linux-kernel, miquel.raynal,
	zbigniew.lukwinski

On Thu, Jan 11, 2024 at 01:15:23AM +0100, Alexandre Belloni wrote:
> On 10/01/2024 17:25:03-0500, Frank Li wrote:
> > RDTERM in MCTRL is 8 bits. Add a length check to prevent silent data errors
> > when the read length exceeds 255 bytes during each i3c_priv_xfer operation.
> > 
> > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > ---
> >  drivers/i3c/master/svc-i3c-master.c | 5 +++++
> >  1 file changed, 5 insertions(+)
> > 
> > diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
> > index bd10bb698da0f..181b56953fb28 100644
> > --- a/drivers/i3c/master/svc-i3c-master.c
> > +++ b/drivers/i3c/master/svc-i3c-master.c
> > @@ -1375,6 +1375,11 @@ static int svc_i3c_master_priv_xfers(struct i3c_dev_desc *dev,
> >  		cmd->len = xfers[i].len;
> >  		cmd->actual_len = xfers[i].rnw ? xfers[i].len : 0;
> >  		cmd->continued = (i + 1) < nxfers;
> > +
> > +		if (cmd->rnw && cmd->len > 255) {
> > +			dev_err(master->dev, "only support read less than 255 each xfer\n");
> 
> What would be the end user action upon seeing this message? Is it actually
> useful?

Hold on, I found an method. It may support > 255 transfer.

Frank Li

> 
> > +			return -EINVAL;
> > +		}
> >  	}
> >  
> >  	mutex_lock(&master->lock);
> > -- 
> > 2.34.1
> > 
> 
> -- 
> Alexandre Belloni, co-owner and COO, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2024-01-11 17:29 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2024-01-10 22:25 [PATCH 1/1] i3c: master: svc: return error when read length bigger than 255 Frank Li
2024-01-11  0:15 ` Alexandre Belloni
2024-01-11 17:29   ` Frank Li

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