diff mbox

[1/2] soundwire: Fix a signedness bug

Message ID 20180109093700.7275ardpus7g6rkq@mwanda (mailing list archive)
State New, archived
Headers show

Commit Message

Dan Carpenter Jan. 9, 2018, 9:37 a.m. UTC 
"ret" is an int and "buf" is a u8.  sdw_read() returns negative error
codes which are truncated to the u8, 0-255 range before being stored as
an int.  It means that "ret" can't be less than zero.

Fixes: b0a9c37b0178 ("soundwire: Add slave status handling")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Comments

Vinod Koul Jan. 10, 2018, 10:54 a.m. UTC | #1 
On Tue, Jan 09, 2018 at 12:37:00PM +0300, Dan Carpenter wrote:
> "ret" is an int and "buf" is a u8.  sdw_read() returns negative error
> codes which are truncated to the u8, 0-255 range before being stored as
> an int.  It means that "ret" can't be less than zero.
> 
> Fixes: b0a9c37b0178 ("soundwire: Add slave status handling")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> 
> diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
> index 4c345197eb55..ac88031f7664 100644
> --- a/drivers/soundwire/bus.c
> +++ b/drivers/soundwire/bus.c
> @@ -771,12 +771,13 @@ static int sdw_handle_slave_alerts(struct sdw_slave *slave)
>  	sdw_modify_slave_status(slave, SDW_SLAVE_ALERT);
>  
>  	/* Read Instat 1, Instat 2 and Instat 3 registers */
> -	ret = buf = sdw_read(slave, SDW_SCP_INT1);
> +	ret = sdw_read(slave, SDW_SCP_INT1);

How about:

	buf = ret = sdw_read(slave, SDW_SCP_INT1);

That should make sure truncation happens latter, but then this is simpler to
read...

>  	if (ret < 0) {
>  		dev_err(slave->bus->dev,
>  					"SDW_SCP_INT1 read failed:%d", ret);
>  		return ret;
>  	}
> +	buf = ret;
>  
>  	ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, buf2);
>  	if (ret < 0) {
> @@ -870,12 +871,13 @@ static int sdw_handle_slave_alerts(struct sdw_slave *slave)
>  		 * Read status again to ensure no new interrupts arrived
>  		 * while servicing interrupts.
>  		 */
> -		ret = _buf = sdw_read(slave, SDW_SCP_INT1);
> +		ret = sdw_read(slave, SDW_SCP_INT1);
>  		if (ret < 0) {
>  			dev_err(slave->bus->dev,
>  					"SDW_SCP_INT1 read failed:%d", ret);
>  			return ret;
>  		}
> +		_buf = ret;
>  
>  		ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, _buf2);
>  		if (ret < 0) {
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel@alsa-project.org
> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
diff mbox

Patch

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index 4c345197eb55..ac88031f7664 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -771,12 +771,13 @@  static int sdw_handle_slave_alerts(struct sdw_slave *slave)
 	sdw_modify_slave_status(slave, SDW_SLAVE_ALERT);
 
 	/* Read Instat 1, Instat 2 and Instat 3 registers */
-	ret = buf = sdw_read(slave, SDW_SCP_INT1);
+	ret = sdw_read(slave, SDW_SCP_INT1);
 	if (ret < 0) {
 		dev_err(slave->bus->dev,
 					"SDW_SCP_INT1 read failed:%d", ret);
 		return ret;
 	}
+	buf = ret;
 
 	ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, buf2);
 	if (ret < 0) {
@@ -870,12 +871,13 @@  static int sdw_handle_slave_alerts(struct sdw_slave *slave)
 		 * Read status again to ensure no new interrupts arrived
 		 * while servicing interrupts.
 		 */
-		ret = _buf = sdw_read(slave, SDW_SCP_INT1);
+		ret = sdw_read(slave, SDW_SCP_INT1);
 		if (ret < 0) {
 			dev_err(slave->bus->dev,
 					"SDW_SCP_INT1 read failed:%d", ret);
 			return ret;
 		}
+		_buf = ret;
 
 		ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, _buf2);
 		if (ret < 0) {