Re: [PATCH v3] usb: wusbcore: Use put_unaligned_le32

From: Himanshu Jha <himanshujha199640@gmail.com>
To: gregkh@linuxfoundation.org
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] usb: wusbcore: Use put_unaligned_le32
Date: Tue, 31 Oct 2017 23:41:45 +0530	[thread overview]
Message-ID: <20171031181145.GA15029@himanshu-Vostro-3559> (raw)
In-Reply-To: <1508240670-8514-1-git-send-email-himanshujha199640@gmail.com>

On Tue, Oct 17, 2017 at 05:14:30PM +0530, Himanshu Jha wrote:

Hi Greg,

> Use put_unaligned_le32 rather than using byte ordering function and
> memcpy which makes code clear.
> Also, add the header file where it is declared.
>

I hope my patch is in your queue!

> Done using Coccinelle and semantic patch used is :
> 
> @ rule1 @
> identifier tmp; expression ptr,x; type T;
> @@
> 
> - tmp = cpu_to_le32(x);
> 
>   <+... when != tmp
> - memcpy(ptr, (T)&tmp, ...);
> + put_unaligned_le32(x,ptr);
>   ...+>
> 
> @ depends on rule1 @
> type j; identifier tmp;
> @@
> 
> - j tmp;
>   ...when != tmp
> 
> Signed-off-by: Himanshu Jha <himanshujha199640@gmail.com>
> ---
> v2:
>    -Added correct header file.
> v3:
>    -Added header file should be at end of include list.
> 
>  drivers/usb/wusbcore/security.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/usb/wusbcore/security.c b/drivers/usb/wusbcore/security.c
> index 170f2c3..7244905 100644
> --- a/drivers/usb/wusbcore/security.c
> +++ b/drivers/usb/wusbcore/security.c
> @@ -28,6 +28,7 @@
>  #include <linux/random.h>
>  #include <linux/export.h>
>  #include "wusbhc.h"
> +#include <asm/unaligned.h>
>  
>  static void wusbhc_gtk_rekey_work(struct work_struct *work);
>  
> @@ -367,7 +368,6 @@ int wusb_dev_4way_handshake(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev,
>  	struct usb_device *usb_dev = wusb_dev->usb_dev;
>  	struct device *dev = &usb_dev->dev;
>  	u32 tkid;
> -	__le32 tkid_le;
>  	struct usb_handshake *hs;
>  	struct aes_ccm_nonce ccm_n;
>  	u8 mic[8];
> @@ -385,11 +385,10 @@ int wusb_dev_4way_handshake(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev,
>  		goto error_dev_set_encryption;
>  
>  	tkid = wusbhc_next_tkid(wusbhc, wusb_dev);
> -	tkid_le = cpu_to_le32(tkid);
>  
>  	hs[0].bMessageNumber = 1;
>  	hs[0].bStatus = 0;
> -	memcpy(hs[0].tTKID, &tkid_le, sizeof(hs[0].tTKID));
> +	put_unaligned_le32(tkid, hs[0].tTKID);
>  	hs[0].bReserved = 0;
>  	memcpy(hs[0].CDID, &wusb_dev->cdid, sizeof(hs[0].CDID));
>  	get_random_bytes(&hs[0].nonce, sizeof(hs[0].nonce));
> @@ -441,7 +440,7 @@ int wusb_dev_4way_handshake(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev,
>  
>  	/* Setup the CCM nonce */
>  	memset(&ccm_n.sfn, 0, sizeof(ccm_n.sfn)); /* Per WUSB1.0[6.5.2] */
> -	memcpy(ccm_n.tkid, &tkid_le, sizeof(ccm_n.tkid));
> +	put_unaligned_le32(tkid, ccm_n.tkid);
>  	ccm_n.src_addr = wusbhc->uwb_rc->uwb_dev.dev_addr;
>  	ccm_n.dest_addr.data[0] = wusb_dev->addr;
>  	ccm_n.dest_addr.data[1] = 0;
> @@ -472,7 +471,7 @@ int wusb_dev_4way_handshake(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev,
>  	/* Send Handshake3 */
>  	hs[2].bMessageNumber = 3;
>  	hs[2].bStatus = 0;
> -	memcpy(hs[2].tTKID, &tkid_le, sizeof(hs[2].tTKID));
> +	put_unaligned_le32(tkid, hs[2].tTKID);
>  	hs[2].bReserved = 0;
>  	memcpy(hs[2].CDID, &wusb_dev->cdid, sizeof(hs[2].CDID));
>  	memcpy(hs[2].nonce, hs[0].nonce, sizeof(hs[2].nonce));
> -- 
> 2.7.4
>

Thanks 
Himanshu Jha