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* [PATCH] Staging : wlan-ng: fix memcpy with ether_addr_copy in p80211conv.c
@ 2015-05-01 11:08 Abhishek Bist
  2015-05-03 19:54 ` Greg KH
  0 siblings, 1 reply; 5+ messages in thread
From: Abhishek Bist @ 2015-05-01 11:08 UTC (permalink / raw)
  To: gregkh; +Cc: linux-kernel, abhishek, stankus.modestas, 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.

Signed-off-by: Abhishek-Bist <ishubist@gmail.com>
---
 drivers/staging/wlan-ng/p80211conv.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/wlan-ng/p80211conv.c b/drivers/staging/wlan-ng/p80211conv.c
index bd69e8c..87661ba 100644
--- a/drivers/staging/wlan-ng/p80211conv.c
+++ b/drivers/staging/wlan-ng/p80211conv.c
@@ -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 =
-- 
1.8.3.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread
* Re: [PATCH] Staging : wlan-ng: fix memcpy with ether_addr_copy in p80211conv.c
  2015-05-01 11:08 [PATCH] Staging : wlan-ng: fix memcpy with ether_addr_copy in p80211conv.c Abhishek Bist
@ 2015-05-03 19:54 ` Greg KH
  2015-05-05 10:55   ` Abhishek Bist
  0 siblings, 1 reply; 5+ messages in thread
From: Greg KH @ 2015-05-03 19:54 UTC (permalink / raw)
  To: Abhishek Bist; +Cc: linux-kernel, abhishek, stankus.modestas

On Fri, May 01, 2015 at 04:38:37PM +0530, Abhishek Bist wrote:
> 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.

> 
> Signed-off-by: Abhishek-Bist <ishubist@gmail.com>

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

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 5+ messages in thread
* [PATCH] Staging : wlan-ng: fix memcpy with ether_addr_copy in p80211conv.c
  2015-05-03 19:54 ` Greg KH
@ 2015-05-05 10:55   ` Abhishek Bist
  2015-05-06  5:32     ` Sudip Mukherjee
  2015-05-10 13:07     ` Greg KH
  0 siblings, 2 replies; 5+ messages in thread
From: Abhishek Bist @ 2015-05-05 10:55 UTC (permalink / raw)
  To: gregkh; +Cc: linux-kernel, 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(-)

diff --git a/drivers/staging/wlan-ng/p80211conv.c b/drivers/staging/wlan-ng/p80211conv.c
index bd69e8c..b3f48074 100644
--- a/drivers/staging/wlan-ng/p80211conv.c
+++ b/drivers/staging/wlan-ng/p80211conv.c
@@ -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 =
-- 
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

^ permalink raw reply related	[flat|nested] 5+ messages in thread
* Re: [PATCH] Staging : wlan-ng: fix memcpy with ether_addr_copy in p80211conv.c
  2015-05-05 10:55   ` Abhishek Bist
@ 2015-05-06  5:32     ` Sudip Mukherjee
  2015-05-10 13:07     ` Greg KH
  1 sibling, 0 replies; 5+ messages in thread
From: Sudip Mukherjee @ 2015-05-06  5:32 UTC (permalink / raw)
  To: Abhishek Bist; +Cc: gregkh, linux-kernel

On Tue, May 05, 2015 at 04:25:31PM +0530, Abhishek Bist wrote:
> 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

^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH] Staging : wlan-ng: fix memcpy with ether_addr_copy in p80211conv.c
  2015-05-05 10:55   ` Abhishek Bist
  2015-05-06  5:32     ` Sudip Mukherjee
@ 2015-05-10 13:07     ` Greg KH
  1 sibling, 0 replies; 5+ messages in thread
From: Greg KH @ 2015-05-10 13:07 UTC (permalink / raw)
  To: Abhishek Bist; +Cc: linux-kernel

On Tue, May 05, 2015 at 04:25:31PM +0530, Abhishek Bist wrote:
> 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 :(

^ permalink raw reply	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2015-05-10 21:03 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-05-01 11:08 [PATCH] Staging : wlan-ng: fix memcpy with ether_addr_copy in p80211conv.c Abhishek Bist
2015-05-03 19:54 ` Greg KH
2015-05-05 10:55   ` Abhishek Bist
2015-05-06  5:32     ` Sudip Mukherjee
2015-05-10 13:07     ` Greg KH

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