diff mbox

[v5,5/5] dvb-usb-v2/gl861: ensure USB message buffers DMA'able

Message ID 20180408172138.9974-6-tskd08@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Akihiro TSUKADA April 8, 2018, 5:21 p.m. UTC 
From: Akihiro Tsukada <tskd08@gmail.com>

i2c message buf might be on stack.

Signed-off-by: Akihiro Tsukada <tskd08@gmail.com>
---
Changes since v4:
- none

 drivers/media/usb/dvb-usb-v2/gl861.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

Comments

Mauro Carvalho Chehab May 5, 2018, 11:17 a.m. UTC | #1 
Em Mon,  9 Apr 2018 02:21:38 +0900
tskd08@gmail.com escreveu:

> From: Akihiro Tsukada <tskd08@gmail.com>
> 
> i2c message buf might be on stack.

That patch also applied without changes. So, just patch 3/5 was not applied.

> 
> Signed-off-by: Akihiro Tsukada <tskd08@gmail.com>
> ---
> Changes since v4:
> - none
> 
>  drivers/media/usb/dvb-usb-v2/gl861.c | 20 +++++++++++++++++---
>  1 file changed, 17 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/usb/dvb-usb-v2/gl861.c b/drivers/media/usb/dvb-usb-v2/gl861.c
> index cdd7bfcb883..47b614da807 100644
> --- a/drivers/media/usb/dvb-usb-v2/gl861.c
> +++ b/drivers/media/usb/dvb-usb-v2/gl861.c
> @@ -22,6 +22,8 @@ static int gl861_i2c_msg(struct dvb_usb_device *d, u8 addr,
>  	u16 value = addr << (8 + 1);
>  	int wo = (rbuf == NULL || rlen == 0); /* write-only */
>  	u8 req, type;
> +	u8 *buf;
> +	int ret;
>  
>  	if (wo) {
>  		req = GL861_REQ_I2C_WRITE;
> @@ -44,11 +46,23 @@ static int gl861_i2c_msg(struct dvb_usb_device *d, u8 addr,
>  				KBUILD_MODNAME, wlen);
>  		return -EINVAL;
>  	}
> -
> +	buf = NULL;
> +	if (rlen > 0) {
> +		buf = kmalloc(rlen, GFP_KERNEL);
> +		if (!buf)
> +			return -ENOMEM;
> +	}
>  	usleep_range(1000, 2000); /* avoid I2C errors */
>  
> -	return usb_control_msg(d->udev, usb_rcvctrlpipe(d->udev, 0), req, type,
> -			       value, index, rbuf, rlen, 2000);
> +	ret = usb_control_msg(d->udev, usb_rcvctrlpipe(d->udev, 0), req, type,
> +			      value, index, buf, rlen, 2000);
> +	if (rlen > 0) {
> +		if (ret > 0)
> +			memcpy(rbuf, buf, rlen);
> +		kfree(buf);
> +	}
> +
> +	return ret;
>  }
>  
>  /* Friio specific I2C read/write */



Thanks,
Mauro
diff mbox

Patch

diff --git a/drivers/media/usb/dvb-usb-v2/gl861.c b/drivers/media/usb/dvb-usb-v2/gl861.c
index cdd7bfcb883..47b614da807 100644
--- a/drivers/media/usb/dvb-usb-v2/gl861.c
+++ b/drivers/media/usb/dvb-usb-v2/gl861.c
@@ -22,6 +22,8 @@  static int gl861_i2c_msg(struct dvb_usb_device *d, u8 addr,
 	u16 value = addr << (8 + 1);
 	int wo = (rbuf == NULL || rlen == 0); /* write-only */
 	u8 req, type;
+	u8 *buf;
+	int ret;
 
 	if (wo) {
 		req = GL861_REQ_I2C_WRITE;
@@ -44,11 +46,23 @@  static int gl861_i2c_msg(struct dvb_usb_device *d, u8 addr,
 				KBUILD_MODNAME, wlen);
 		return -EINVAL;
 	}
-
+	buf = NULL;
+	if (rlen > 0) {
+		buf = kmalloc(rlen, GFP_KERNEL);
+		if (!buf)
+			return -ENOMEM;
+	}
 	usleep_range(1000, 2000); /* avoid I2C errors */
 
-	return usb_control_msg(d->udev, usb_rcvctrlpipe(d->udev, 0), req, type,
-			       value, index, rbuf, rlen, 2000);
+	ret = usb_control_msg(d->udev, usb_rcvctrlpipe(d->udev, 0), req, type,
+			      value, index, buf, rlen, 2000);
+	if (rlen > 0) {
+		if (ret > 0)
+			memcpy(rbuf, buf, rlen);
+		kfree(buf);
+	}
+
+	return ret;
 }
 
 /* Friio specific I2C read/write */