[RESEND PATCH 0/2] Staging: Use put_unaligned_le16

[RESEND PATCH 0/2] Staging: Use put_unaligned_le16

[Vaishali Thakkar]

This patch series introduces the use of function 
put_unaligned_le16 as using byte ordering functions 
and then memcpy() is risky and prone to hide errors 
which are hard to track down. 

This change is done using Coccinelle.

Vaishali Thakkar (2):
  Staging: rtl8188eu: Use put_unaligned_le16
  Staging: rtl8723au: Use put_unaligned_le16

 drivers/staging/rtl8188eu/core/rtw_ap.c | 8 +++-----
 drivers/staging/rtl8723au/core/rtw_ap.c | 8 +++-----
 2 files changed, 6 insertions(+), 10 deletions(-)

-- 
1.9.1

[RESEND PATCH v3 1/2] Staging: rtl8188eu: Use put_unaligned_le16

[Vaishali Thakkar]

Using byte ordering functions and then memcpy() is risky and
prone to hide errors which are hard to track down. So, this
patch introduces the use of function put_unaligned_le16 which
makes the code clear. Here, use of variable tim_bitmap_le
and variable itself is removed. Also, to be compatible with the
changes header file is added too.

Coccinelle is used to do this change and semantic patch used for
this is as follows:

@a@
typedef __le16;
__le16 e16;
identifier tmp;
expression ptr;
expression y,e;
type T;
@@

- tmp = cpu_to_le16(y);

<+... when != tmp
(
- memcpy(ptr, (T)&tmp, \(2\|sizeof(__le16)\|sizeof(e16)\));
+ put_unaligned_le16(y,ptr);
|
- memcpy(ptr, (T)&tmp, ...);
+ put_unaligned_le16(y,ptr);
)
...+>
? tmp = e

@@ type T; identifier a.tmp; @@

- T tmp;
...when != tmp

Signed-off-by: Vaishali Thakkar <vthakkar1994@gmail.com>
---
Changes since v2:
	-Edit commit log
	-Merge this patch in a patch-series

Changes since v1:
	-Remove use of variable tim_bitmap_le
	-Remove variable tim_bitmap_le
	-Add header file to be compatible with the changes
	-Edit commit log

 drivers/staging/rtl8188eu/core/rtw_ap.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/rtl8188eu/core/rtw_ap.c b/drivers/staging/rtl8188eu/core/rtw_ap.c
index da19145..e65ee6e 100644
--- a/drivers/staging/rtl8188eu/core/rtw_ap.c
+++ b/drivers/staging/rtl8188eu/core/rtw_ap.c
@@ -23,6 +23,7 @@
 #include <drv_types.h>
 #include <wifi.h>
 #include <ieee80211.h>
+#include <asm/unaligned.h>
 
 #ifdef CONFIG_88EU_AP_MODE
 
@@ -78,11 +79,8 @@ static void update_BCNTIM(struct adapter *padapter)
 	if (true) {
 		u8 *p, *dst_ie, *premainder_ie = NULL;
 		u8 *pbackup_remainder_ie = NULL;
-		__le16 tim_bitmap_le;
 		uint offset, tmp_len, tim_ielen, tim_ie_offset, remainder_ielen;
 
-		tim_bitmap_le = cpu_to_le16(pstapriv->tim_bitmap);
-
 		p = rtw_get_ie(pie + _FIXED_IE_LENGTH_, _TIM_IE_, &tim_ielen, pnetwork_mlmeext->IELength - _FIXED_IE_LENGTH_);
 		if (p != NULL && tim_ielen > 0) {
 			tim_ielen += 2;
@@ -137,9 +135,9 @@ static void update_BCNTIM(struct adapter *padapter)
 			*dst_ie++ = 0;
 
 		if (tim_ielen == 4) {
-			*dst_ie++ = *(u8 *)&tim_bitmap_le;
+			*dst_ie++ = pstapriv->tim_bitmap & 0xff;
 		} else if (tim_ielen == 5) {
-			memcpy(dst_ie, &tim_bitmap_le, 2);
+			put_unaligned_le16(pstapriv->tim_bitmap, dst_ie);
 			dst_ie += 2;
 		}
 
-- 
1.9.1

[RESEND PATCH v2 2/2] Staging: rtl8723au: Use put_unaligned_le16

[Vaishali Thakkar]

Using byte ordering functions and then memcpy() is risky and
prone to hide errors which are hard to track down. So, this
patch introduces the use of function put_unaligned_le16 which
makes the code clear. Here, use of variable tim_bitmap_le
and variable itself is removed. Also, to be compatible with the
changes header file is added too.

Coccinelle is used to do this change and semantic patch used for
this is as follows:

@a@
typedef __le16;
__le16 e16;
identifier tmp;
expression ptr;
expression y,e;
type T;
@@

- tmp = cpu_to_le16(y);

<+... when != tmp
(
- memcpy(ptr, (T)&tmp, \(2\|sizeof(__le16)\|sizeof(e16)\));
+ put_unaligned_le16(y,ptr);
|
- memcpy(ptr, (T)&tmp, ...);
+ put_unaligned_le16(y,ptr);
)
...+>
? tmp = e

@@ type T; identifier a.tmp; @@

- T tmp;
...when != tmp

Signed-off-by: Vaishali Thakkar <vthakkar1994@gmail.com>
---
Changes since v1:
	-Edit commit log
	-Merge this patch in a patch series

 drivers/staging/rtl8723au/core/rtw_ap.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/rtl8723au/core/rtw_ap.c b/drivers/staging/rtl8723au/core/rtw_ap.c
index c6327c0..7fa4352 100644
--- a/drivers/staging/rtl8723au/core/rtw_ap.c
+++ b/drivers/staging/rtl8723au/core/rtw_ap.c
@@ -20,6 +20,7 @@
 #include <wifi.h>
 #include <rtl8723a_cmd.h>
 #include <rtl8723a_hal.h>
+#include <asm/unaligned.h>
 
 extern unsigned char WMM_OUI23A[];
 extern unsigned char WPS_OUI23A[];
@@ -72,11 +73,8 @@ static void update_BCNTIM(struct rtw_adapter *padapter)
 	struct wlan_bssid_ex *pnetwork_mlmeext = &pmlmeinfo->network;
 	unsigned char *pie = pnetwork_mlmeext->IEs;
 	u8 *p, *dst_ie, *premainder_ie = NULL, *pbackup_remainder_ie = NULL;
-	__le16 tim_bitmap_le;
 	uint offset, tmp_len, tim_ielen, tim_ie_offset, remainder_ielen;
 
-	tim_bitmap_le = cpu_to_le16(pstapriv->tim_bitmap);
-
 	p = rtw_get_ie23a(pie, WLAN_EID_TIM, &tim_ielen,
 			  pnetwork_mlmeext->IELength);
 	if (p != NULL && tim_ielen > 0) {
@@ -143,9 +141,9 @@ static void update_BCNTIM(struct rtw_adapter *padapter)
 		*dst_ie++ = 0;
 
 	if (tim_ielen == 4) {
-		*dst_ie++ = *(u8 *)&tim_bitmap_le;
+		*dst_ie++ = pstapriv->tim_bitmap & 0xff;
 	} else if (tim_ielen == 5) {
-		memcpy(dst_ie, &tim_bitmap_le, 2);
+		put_unaligned_le16(pstapriv->tim_bitmap, dst_ie);
 		dst_ie += 2;
 	}
 
-- 
1.9.1

Re: [Outreachy kernel] [RESEND PATCH v2 2/2] Staging: rtl8723au: Use put_unaligned_le16

[Arnd Bergmann]

On Friday 20 February 2015 14:18:45 Vaishali Thakkar wrote:
> Using byte ordering functions and then memcpy() is risky and
> prone to hide errors which are hard to track down. So, this
> patch introduces the use of function put_unaligned_le16 which
> makes the code clear. Here, use of variable tim_bitmap_le
> and variable itself is removed. Also, to be compatible with the
> changes header file is added too.
> 
> Coccinelle is used to do this change and semantic patch used for
> this is as follows:
> 
> @a@
> typedef __le16;
> __le16 e16;
> identifier tmp;
> expression ptr;
> expression y,e;
> type T;
> @@
> 
> - tmp = cpu_to_le16(y);
> 
> <+... when != tmp
> (
> - memcpy(ptr, (T)&tmp, \(2\|sizeof(__le16)\|sizeof(e16)\));
> + put_unaligned_le16(y,ptr);
> |
> - memcpy(ptr, (T)&tmp, ...);
> + put_unaligned_le16(y,ptr);
> )
> ...+>
> ? tmp = e
> 
> @@ type T; identifier a.tmp; @@
> 
> - T tmp;
> ...when != tmp
> 
> Signed-off-by: Vaishali Thakkar <vthakkar1994@gmail.com>
> 

Reviewed-by: Arnd Bergmann <arnd@arndb.de>

Re: [Outreachy kernel] [RESEND PATCH v3 1/2] Staging: rtl8188eu: Use put_unaligned_le16

[Arnd Bergmann]

On Friday 20 February 2015 14:18:37 Vaishali Thakkar wrote:
> Using byte ordering functions and then memcpy() is risky and
> prone to hide errors which are hard to track down. So, this
> patch introduces the use of function put_unaligned_le16 which
> makes the code clear. Here, use of variable tim_bitmap_le
> and variable itself is removed. Also, to be compatible with the
> changes header file is added too.
> 
> Coccinelle is used to do this change and semantic patch used for
> this is as follows:
> 
> @a@
> typedef __le16;
> __le16 e16;
> identifier tmp;
> expression ptr;
> expression y,e;
> type T;
> @@
> 
> - tmp = cpu_to_le16(y);
> 
> <+... when != tmp
> (
> - memcpy(ptr, (T)&tmp, \(2\|sizeof(__le16)\|sizeof(e16)\));
> + put_unaligned_le16(y,ptr);
> |
> - memcpy(ptr, (T)&tmp, ...);
> + put_unaligned_le16(y,ptr);
> )
> ...+>
> ? tmp = e
> 
> @@ type T; identifier a.tmp; @@
> 
> - T tmp;
> ...when != tmp
> 
> Signed-off-by: Vaishali Thakkar <vthakkar1994@gmail.com>
> 

Reviewed-by: Arnd Bergmann <arnd@arndb.de>