Staging : wlan-ng: fix memcpy with ether_addr_copy in p80211conv.c

PATCH In review Abhishek Bist 3 participants 5 messages May 1, 2015 – May 10, 2015 Staging

Share & tools

Abhishek Bist

author

2015-05-01 11:08 UTC #0 lore raw

PATCH 1/1 Staging : wlan-ng: fix memcpy with ether_addr_copy in p80211conv.c

This is a patch which fixes memcpy warning found by a checpatch.pl in p80211conv.c and replaces memcpy with ether_addr_copy.

Signed-off-by Abhishek-Bist <[email protected]>

---
 drivers/staging/wlan-ng/p80211conv.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

drivers/staging/wlan-ng/p80211conv.c +12 ~~-10~~

index bd69e8c..87661ba 100644
@@ -178,21 +178,23 @@ int skb_ether_to_p80211(wlandevice_t *wlandev, u32 ethconv,
 
 	switch (wlandev->macmode) {
 	case WLAN_MACMODE_IBSS_STA:
-		memcpy(p80211_hdr->a3.a1, &e_hdr.daddr, ETH_ALEN);
-		memcpy(p80211_hdr->a3.a2, wlandev->netdev->dev_addr, ETH_ALEN);
-		memcpy(p80211_hdr->a3.a3, wlandev->bssid, ETH_ALEN);
+		ether_addr_copy(p80211_hdr->a3.a1, &e_hdr.daddr, ETH_ALEN);
+		ether_addr_copy(p80211_hdr->a3.a2, wlandev->netdev->dev_addr,
+				ETH_ALEN);
+		ether_addr_copy(p80211_hdr->a3.a3, wlandev->bssid, ETH_ALEN);
 		break;
 	case WLAN_MACMODE_ESS_STA:
 		fc |= cpu_to_le16(WLAN_SET_FC_TODS(1));
-		memcpy(p80211_hdr->a3.a1, wlandev->bssid, ETH_ALEN);
-		memcpy(p80211_hdr->a3.a2, wlandev->netdev->dev_addr, ETH_ALEN);
-		memcpy(p80211_hdr->a3.a3, &e_hdr.daddr, ETH_ALEN);
+		ether_addr_copy(p80211_hdr->a3.a1, wlandev->bssid, ETH_ALEN);
+		ether_addr_copy(p80211_hdr->a3.a2, wlandev->netdev->dev_addr,
+				ETH_ALEN);
+		ether_addr_copy(p80211_hdr->a3.a3, &e_hdr.daddr, ETH_ALEN);
 		break;
 	case WLAN_MACMODE_ESS_AP:
 		fc |= cpu_to_le16(WLAN_SET_FC_FROMDS(1));
-		memcpy(p80211_hdr->a3.a1, &e_hdr.daddr, ETH_ALEN);
-		memcpy(p80211_hdr->a3.a2, wlandev->bssid, ETH_ALEN);
-		memcpy(p80211_hdr->a3.a3, &e_hdr.saddr, ETH_ALEN);
+		ether_addr_copy(p80211_hdr->a3.a1, &e_hdr.daddr, ETH_ALEN);
+		ether_addr_copy(p80211_hdr->a3.a2, wlandev->bssid, ETH_ALEN);
+		ether_addr_copy(p80211_hdr->a3.a3, &e_hdr.saddr, ETH_ALEN);
 		break;
 	default:
 		netdev_err(wlandev->netdev,

@@ -241,7 +243,7 @@ static void orinoco_spy_gather(wlandevice_t *wlandev, char *mac,
 	for (i = 0; i < wlandev->spy_number; i++) {
 
 		if (!memcmp(wlandev->spy_address[i], mac, ETH_ALEN)) {
-			memcpy(wlandev->spy_address[i], mac, ETH_ALEN);
+			ether_addr_copy(wlandev->spy_address[i], mac, ETH_ALEN);
 			wlandev->spy_stat[i].level = rxmeta->signal;
 			wlandev->spy_stat[i].noise = rxmeta->noise;
 			wlandev->spy_stat[i].qual =

Signature · 1 line

1.8.3.1

Greg KH

maintainer

2015-05-03 20:30 UTC #1 lore raw

Quoted 2 lines · Abhishek Bist

This is a patch which fixes memcpy warning found by a checpatch.pl in p80211conv.c and replaces memcpy with ether_addr_copy.

How do you "know" it is safe to do this? Please prove it.

Quoted 2 lines

Signed-off-by Abhishek-Bist <[email protected]>

Your From: name and this name do not match :(

thanks,

greg k-h

Abhishek Bist

author

2015-05-05 10:55 UTC #2 lore raw

PATCH 1/1 Staging : wlan-ng: fix memcpy with ether_addr_copy in p80211conv.c

This is a patch which fixes memcpy warning found by a checpatch.pl in p80211conv.c and replaces memcpy with ether_addr_copy.

---
 drivers/staging/wlan-ng/p80211conv.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

drivers/staging/wlan-ng/p80211conv.c +10 ~~-10~~

index bd69e8c..b3f48074 100644
@@ -178,21 +178,21 @@ int skb_ether_to_p80211(wlandevice_t *wlandev, u32 ethconv,
 
 	switch (wlandev->macmode) {
 	case WLAN_MACMODE_IBSS_STA:
-		memcpy(p80211_hdr->a3.a1, &e_hdr.daddr, ETH_ALEN);
-		memcpy(p80211_hdr->a3.a2, wlandev->netdev->dev_addr, ETH_ALEN);
-		memcpy(p80211_hdr->a3.a3, wlandev->bssid, ETH_ALEN);
+		ether_addr_copy(p80211_hdr->a3.a1, &e_hdr.daddr);
+		ether_addr_copy(p80211_hdr->a3.a2, wlandev->netdev->dev_addr);
+		ether_addr_copy(p80211_hdr->a3.a3, wlandev->bssid);
 		break;
 	case WLAN_MACMODE_ESS_STA:
 		fc |= cpu_to_le16(WLAN_SET_FC_TODS(1));
-		memcpy(p80211_hdr->a3.a1, wlandev->bssid, ETH_ALEN);
-		memcpy(p80211_hdr->a3.a2, wlandev->netdev->dev_addr, ETH_ALEN);
-		memcpy(p80211_hdr->a3.a3, &e_hdr.daddr, ETH_ALEN);
+		ether_addr_copy(p80211_hdr->a3.a1, wlandev->bssid);
+		ether_addr_copy(p80211_hdr->a3.a2, wlandev->netdev->dev_addr);
+		ether_addr_copy(p80211_hdr->a3.a3, &e_hdr.daddr);
 		break;
 	case WLAN_MACMODE_ESS_AP:
 		fc |= cpu_to_le16(WLAN_SET_FC_FROMDS(1));
-		memcpy(p80211_hdr->a3.a1, &e_hdr.daddr, ETH_ALEN);
-		memcpy(p80211_hdr->a3.a2, wlandev->bssid, ETH_ALEN);
-		memcpy(p80211_hdr->a3.a3, &e_hdr.saddr, ETH_ALEN);
+		ether_addr_copy(p80211_hdr->a3.a1, &e_hdr.daddr);
+		ether_addr_copy(p80211_hdr->a3.a2, wlandev->bssid);
+		ether_addr_copy(p80211_hdr->a3.a3, &e_hdr.saddr);
 		break;
 	default:
 		netdev_err(wlandev->netdev,

@@ -241,7 +241,7 @@ static void orinoco_spy_gather(wlandevice_t *wlandev, char *mac,
 	for (i = 0; i < wlandev->spy_number; i++) {
 
 		if (!memcmp(wlandev->spy_address[i], mac, ETH_ALEN)) {
-			memcpy(wlandev->spy_address[i], mac, ETH_ALEN);
+			ether_addr_copy(wlandev->spy_address[i], mac);
 			wlandev->spy_stat[i].level = rxmeta->signal;
 			wlandev->spy_stat[i].noise = rxmeta->noise;
 			wlandev->spy_stat[i].qual =

Signature · 13 lines

1.8.3.1

How do you "know" it is safe to do this?  Please prove it.




Yes, it is safe to do this because the basic pre-requisite of ether_addr_copy() over memcpy() is that ether_addr_copy() 
is strictly designed to copy an ethernet address where source and destination are a 6 byte array which is true in my case as
p80211_hdr->a3.a1,p80211_hdr->a3.a2,p80211_hdr->a3.a3 are all a six byte array and the next important thing is that they should 
be u16 alligned.So, for that sake i checked it by pahole which clearly shows that the source and destination are u16 byte alligned.And on some architecture ether_addr_copy is faster than memcpy().
	So, it's seems fair enough to use ether_addr_copy() over memcpy() when the size of data to be copied is ETH_ALEN which is 
#define ETH_ALEN 6

Sudip Mukherjee

2015-05-06 05:32 UTC #3 lore raw

Quoted 3 lines · Abhishek Bist

This is a patch which fixes memcpy warning found by a checpatch.pl in p80211conv.c and replaces memcpy with ether_addr_copy.
---

you missed the the Signed-off-by:

regards
sudip

Greg KH

maintainer

2015-05-10 21:03 UTC #4 lore raw

In reply to Abhishek Bist

Quoted 5 lines · Abhishek Bist

This is a patch which fixes memcpy warning found by a checpatch.pl in p80211conv.c and replaces memcpy with ether_addr_copy.
---
 drivers/staging/wlan-ng/p80211conv.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

We need proof this is ok to do, like I asked last time :(