[v1] USB: serial: use kmemdup instead of kmalloc + memcpy

[PATCH] USB: serial: use kmemdup instead of kmalloc + memcpy

Posted by Slark Xiao 3 years, 10 months ago

For code neat purpose, we can use kmemdup to replace
kmalloc + memcpy.

Signed-off-by: Slark Xiao <slark_xiao@163.com>
---
 drivers/usb/serial/opticon.c | 4 +---
 drivers/usb/serial/sierra.c  | 4 +---
 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/serial/opticon.c b/drivers/usb/serial/opticon.c
index aed28c35caff..bca6766a63e6 100644
--- a/drivers/usb/serial/opticon.c
+++ b/drivers/usb/serial/opticon.c
@@ -208,7 +208,7 @@ static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
 	priv->outstanding_bytes += count;
 	spin_unlock_irqrestore(&priv->lock, flags);
 
-	buffer = kmalloc(count, GFP_ATOMIC);
+	buffer = kmemdup(buf, count, GFP_ATOMIC);
 	if (!buffer)
 		goto error_no_buffer;
 
@@ -216,8 +216,6 @@ static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
 	if (!urb)
 		goto error_no_urb;
 
-	memcpy(buffer, buf, count);
-
 	usb_serial_debug_data(&port->dev, __func__, count, buffer);
 
 	/* The connected devices do not have a bulk write endpoint,
diff --git a/drivers/usb/serial/sierra.c b/drivers/usb/serial/sierra.c
index 9d56138133a9..865d1237d611 100644
--- a/drivers/usb/serial/sierra.c
+++ b/drivers/usb/serial/sierra.c
@@ -453,7 +453,7 @@ static int sierra_write(struct tty_struct *tty, struct usb_serial_port *port,
 		goto error_simple;
 	}
 
-	buffer = kmalloc(writesize, GFP_ATOMIC);
+	buffer = kmemdup(buf, writesize, GFP_ATOMIC);
 	if (!buffer) {
 		retval = -ENOMEM;
 		goto error_no_buffer;
@@ -465,8 +465,6 @@ static int sierra_write(struct tty_struct *tty, struct usb_serial_port *port,
 		goto error_no_urb;
 	}
 
-	memcpy(buffer, buf, writesize);
-
 	usb_serial_debug_data(&port->dev, __func__, writesize, buffer);
 
 	usb_fill_bulk_urb(urb, serial->dev,
-- 
2.25.1

Re: [PATCH] USB: serial: use kmemdup instead of kmalloc + memcpy

Posted by Johan Hovold 3 years, 10 months ago

On Mon, Jun 20, 2022 at 06:59:39PM +0800, Slark Xiao wrote:
> For code neat purpose, we can use kmemdup to replace
> kmalloc + memcpy.
> 
> Signed-off-by: Slark Xiao <slark_xiao@163.com>
> ---
>  drivers/usb/serial/opticon.c | 4 +---
>  drivers/usb/serial/sierra.c  | 4 +---
>  2 files changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/usb/serial/opticon.c b/drivers/usb/serial/opticon.c
> index aed28c35caff..bca6766a63e6 100644
> --- a/drivers/usb/serial/opticon.c
> +++ b/drivers/usb/serial/opticon.c
> @@ -208,7 +208,7 @@ static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
>  	priv->outstanding_bytes += count;
>  	spin_unlock_irqrestore(&priv->lock, flags);
>  
> -	buffer = kmalloc(count, GFP_ATOMIC);
> +	buffer = kmemdup(buf, count, GFP_ATOMIC);
>  	if (!buffer)
>  		goto error_no_buffer;
>  
> @@ -216,8 +216,6 @@ static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
>  	if (!urb)
>  		goto error_no_urb;
>  
> -	memcpy(buffer, buf, count);
> -
>  	usb_serial_debug_data(&port->dev, __func__, count, buffer);
>  
>  	/* The connected devices do not have a bulk write endpoint,

Looks like we have the same pattern also in garmin_write_bulk(). Care to
include that one as well?

Johan

Re:Re: [PATCH] USB: serial: use kmemdup instead of kmalloc + memcpy

Posted by Slark Xiao 3 years, 10 months ago


At 2022-06-20 21:10:49, "Johan Hovold" <johan@kernel.org> wrote:
>On Mon, Jun 20, 2022 at 06:59:39PM +0800, Slark Xiao wrote:
>> For code neat purpose, we can use kmemdup to replace
>> kmalloc + memcpy.
>> 
>> Signed-off-by: Slark Xiao <slark_xiao@163.com>
>> ---
>>  drivers/usb/serial/opticon.c | 4 +---
>>  drivers/usb/serial/sierra.c  | 4 +---
>>  2 files changed, 2 insertions(+), 6 deletions(-)
>> 
>> diff --git a/drivers/usb/serial/opticon.c b/drivers/usb/serial/opticon.c
>> index aed28c35caff..bca6766a63e6 100644
>> --- a/drivers/usb/serial/opticon.c
>> +++ b/drivers/usb/serial/opticon.c
>> @@ -208,7 +208,7 @@ static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
>>  	priv->outstanding_bytes += count;
>>  	spin_unlock_irqrestore(&priv->lock, flags);
>>  
>> -	buffer = kmalloc(count, GFP_ATOMIC);
>> +	buffer = kmemdup(buf, count, GFP_ATOMIC);
>>  	if (!buffer)
>>  		goto error_no_buffer;
>>  
>> @@ -216,8 +216,6 @@ static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
>>  	if (!urb)
>>  		goto error_no_urb;
>>  
>> -	memcpy(buffer, buf, count);
>> -
>>  	usb_serial_debug_data(&port->dev, __func__, count, buffer);
>>  
>>  	/* The connected devices do not have a bulk write endpoint,
>
>Looks like we have the same pattern also in garmin_write_bulk(). Care to
>include that one as well?
>
>Johan
Ok, I will add it into the patch as well in V2.