mac80211: use separate spinlock for sta flags
David Ellingsworth posted a bug that was only noticable on UP/NO-PREEMPT
and Michael correctly analysed it to be a spin_lock_bh() section within
a spin_lock_irqsave() section. This adds a separate spinlock for the
sta_info flags to fix that issue and avoid having to take much care
about where the sta flag manipulation functions are called.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Reported-By: David Ellingsworth <david@identd.dyndns.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index c24770c..b3c7331 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -235,6 +235,7 @@
return NULL;
spin_lock_init(&sta->lock);
+ spin_lock_init(&sta->flaglock);
memcpy(sta->addr, addr, ETH_ALEN);
sta->local = local;
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 95753f8..fd228c1 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -164,6 +164,7 @@
* @aid: STA's unique AID (1..2007, 0 = not assigned yet),
* only used in AP (and IBSS?) mode
* @flags: STA flags, see &enum ieee80211_sta_info_flags
+ * @flaglock: spinlock for flags accesses
* @ps_tx_buf: buffer of frames to transmit to this station
* when it leaves power saving state
* @tx_filtered: buffer of frames we already tried to transmit
@@ -186,6 +187,7 @@
struct rate_control_ref *rate_ctrl;
void *rate_ctrl_priv;
spinlock_t lock;
+ spinlock_t flaglock;
struct ieee80211_ht_info ht_info;
u64 supp_rates[IEEE80211_NUM_BANDS];
u8 addr[ETH_ALEN];
@@ -198,7 +200,10 @@
*/
u8 pin_status;
- /* frequently updated information, locked with lock spinlock */
+ /*
+ * frequently updated, locked with own spinlock (flaglock),
+ * use the accessors defined below
+ */
u32 flags;
/*
@@ -293,34 +298,41 @@
static inline void set_sta_flags(struct sta_info *sta, const u32 flags)
{
- spin_lock_bh(&sta->lock);
+ unsigned long irqfl;
+
+ spin_lock_irqsave(&sta->flaglock, irqfl);
sta->flags |= flags;
- spin_unlock_bh(&sta->lock);
+ spin_unlock_irqrestore(&sta->flaglock, irqfl);
}
static inline void clear_sta_flags(struct sta_info *sta, const u32 flags)
{
- spin_lock_bh(&sta->lock);
+ unsigned long irqfl;
+
+ spin_lock_irqsave(&sta->flaglock, irqfl);
sta->flags &= ~flags;
- spin_unlock_bh(&sta->lock);
+ spin_unlock_irqrestore(&sta->flaglock, irqfl);
}
static inline void set_and_clear_sta_flags(struct sta_info *sta,
const u32 set, const u32 clear)
{
- spin_lock_bh(&sta->lock);
+ unsigned long irqfl;
+
+ spin_lock_irqsave(&sta->flaglock, irqfl);
sta->flags |= set;
sta->flags &= ~clear;
- spin_unlock_bh(&sta->lock);
+ spin_unlock_irqrestore(&sta->flaglock, irqfl);
}
static inline u32 test_sta_flags(struct sta_info *sta, const u32 flags)
{
u32 ret;
+ unsigned long irqfl;
- spin_lock_bh(&sta->lock);
+ spin_lock_irqsave(&sta->flaglock, irqfl);
ret = sta->flags & flags;
- spin_unlock_bh(&sta->lock);
+ spin_unlock_irqrestore(&sta->flaglock, irqfl);
return ret;
}
@@ -329,11 +341,12 @@
const u32 flags)
{
u32 ret;
+ unsigned long irqfl;
- spin_lock_bh(&sta->lock);
+ spin_lock_irqsave(&sta->flaglock, irqfl);
ret = sta->flags & flags;
sta->flags &= ~flags;
- spin_unlock_bh(&sta->lock);
+ spin_unlock_irqrestore(&sta->flaglock, irqfl);
return ret;
}
@@ -341,10 +354,11 @@
static inline u32 get_sta_flags(struct sta_info *sta)
{
u32 ret;
+ unsigned long irqfl;
- spin_lock_bh(&sta->lock);
+ spin_lock_irqsave(&sta->flaglock, irqfl);
ret = sta->flags;
- spin_unlock_bh(&sta->lock);
+ spin_unlock_irqrestore(&sta->flaglock, irqfl);
return ret;
}