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mac80211: Fixing sparse warning at sta_info.c

PATCH In review Yogesh Ashok Powar 2 participants 3 messages Dec 16, 2011 – Dec 19, 2011 mac80211

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Yogesh Ashok Powar

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#0 lore raw

PATCH v2 1/1 mac80211: Fixing sparse warning at sta_info.c

The commit 42624d4913a00219a8fdbb4bafd634d1d843be85 created following sparse warning

Quoted 3 lines

net/mac80211/sta_info.c:965:24: warning: incorrect type in assignment (different address spaces)
net/mac80211/sta_info.c:965:24: expected struct tid_ampdu_tx *tid_tx
net/mac80211/sta_info.c:965:24: got struct tid_ampdu_tx [noderef] <asn:4>*<noident>

Making use of rcu_dereference_protected to fix the problem.

V2:
- Replacing rcu_dereference with rcu_dereference_protected as suggested by Johannes.
- Adding mutex_lock/unlock to satisfy the condition at rcu_dereference_protected

Cc Nishant Sarmukadam <[email protected]>
Reported-by Johannes Berg <[email protected]>
Signed-off-by Yogesh Ashok Powar <[email protected]>
---
 net/mac80211/sta_info.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)
net/mac80211/sta_info.c +7 -2
index c6ca9bd..e4307b7 100644
@@ -959,10 +959,13 @@ static int __must_check __sta_info_destroy(struct sta_info *sta)
 	 * until the aggregation stop completes. Refer
 	 * http://thread.gmane.org/gmane.linux.kernel.wireless.general/81936
 	 */
+
+	mutex_lock(&sta->ampdu_mlme.mtx);
+
 	for (i = 0; i < STA_TID_NUM; i++) {
-		if (!sta->ampdu_mlme.tid_tx[i])
+		tid_tx = rcu_dereference_protected_tid_tx(sta, i);
+		if (!tid_tx)
 			continue;
-		tid_tx = sta->ampdu_mlme.tid_tx[i];
 		if (skb_queue_len(&tid_tx->pending)) {
 #ifdef CONFIG_MAC80211_HT_DEBUG
 			wiphy_debug(local->hw.wiphy, "TX A-MPDU  purging %d "

@@ -974,6 +977,8 @@ static int __must_check __sta_info_destroy(struct sta_info *sta)
 		kfree_rcu(tid_tx, rcu_head);
 	}
 
+	mutex_unlock(&sta->ampdu_mlme.mtx);
+
 	__sta_info_free(local, sta);
 
 	return 0;
Signature · 1 line
1.7.5.4
#1 lore raw

Applying: mac80211: Fixing sparse warning at sta_info.c
error: patch failed: net/mac80211/sta_info.c:974
error: net/mac80211/sta_info.c: patch does not apply

What tree did you use as a base for your patch?

Quoted 58 lines · Yogesh Ashok Powar

The commit 42624d4913a00219a8fdbb4bafd634d1d843be85 created following sparse warning

Quoted 3 lines

net/mac80211/sta_info.c:965:24: warning: incorrect type in assignment (different address spaces)
net/mac80211/sta_info.c:965:24: expected struct tid_ampdu_tx *tid_tx
net/mac80211/sta_info.c:965:24: got struct tid_ampdu_tx [noderef] <asn:4>*<noident>

Making use of rcu_dereference_protected to fix the problem.

V2:
- Replacing rcu_dereference with rcu_dereference_protected as suggested by Johannes.
- Adding mutex_lock/unlock to satisfy the condition at rcu_dereference_protected

Cc Nishant Sarmukadam <[email protected]>
Reported-by Johannes Berg <[email protected]>
Signed-off-by Yogesh Ashok Powar <[email protected]>
---
 net/mac80211/sta_info.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)
net/mac80211/sta_info.c +7 -2
index c6ca9bd..e4307b7 100644
@@ -959,10 +959,13 @@ static int __must_check __sta_info_destroy(struct sta_info *sta)
 	 * until the aggregation stop completes. Refer
 	 * http://thread.gmane.org/gmane.linux.kernel.wireless.general/81936
 	 */
+
+	mutex_lock(&sta->ampdu_mlme.mtx);
+
 	for (i = 0; i < STA_TID_NUM; i++) {
-		if (!sta->ampdu_mlme.tid_tx[i])
+		tid_tx = rcu_dereference_protected_tid_tx(sta, i);
+		if (!tid_tx)
 			continue;
-		tid_tx = sta->ampdu_mlme.tid_tx[i];
 		if (skb_queue_len(&tid_tx->pending)) {
 #ifdef CONFIG_MAC80211_HT_DEBUG
 			wiphy_debug(local->hw.wiphy, "TX A-MPDU  purging %d "

@@ -974,6 +977,8 @@ static int __must_check __sta_info_destroy(struct sta_info *sta)
 		kfree_rcu(tid_tx, rcu_head);
 	}
 
+	mutex_unlock(&sta->ampdu_mlme.mtx);
+
 	__sta_info_free(local, sta);
 
 	return 0;
Signature · 6 lines
1.7.5.4

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Signature · 2 lines
John W. Linville		Someday the world will need a hero, and you
[email protected]			might be all we have.  Be ready.
#2 lore raw
Quoted 5 lines · John W. Linville

Applying: mac80211: Fixing sparse warning at sta_info.c
error: patch failed: net/mac80211/sta_info.c:974
error: net/mac80211/sta_info.c: patch does not apply

What tree did you use as a base for your patch?

NM -- it was simple to fix-up, even if 'git apply' couldn't figure it out...

John

Signature · 2 lines
John W. Linville		Someday the world will need a hero, and you
[email protected]			might be all we have.  Be ready.