diff options
| author | Felix Fietkau <nbd@openwrt.org> | 2013-05-03 12:01:03 +0400 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2013-05-17 00:38:05 +0400 |
| commit | f6b3d85f7f6d66f890862d763b2ed092c5dd4322 (patch) | |
| tree | 3e6ca47a09a6ee3418aa2ab14d14d3534c2b9279 | |
| parent | 3670946fe2e942bcb09ec9bbc587bf305f9f97da (diff) | |
| download | linux-f6b3d85f7f6d66f890862d763b2ed092c5dd4322.tar.xz | |
mac80211: fix spurious RCU warning and update documentation
Document rx vs tx status concurrency requirements.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
| -rw-r--r-- | include/net/mac80211.h | 12 | ||||
| -rw-r--r-- | net/mac80211/rate.c | 9 |
2 files changed, 16 insertions, 5 deletions
diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 04c2d4670dc6..885898a40d13 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -3043,7 +3043,8 @@ void ieee80211_napi_complete(struct ieee80211_hw *hw); * This function may not be called in IRQ context. Calls to this function * for a single hardware must be synchronized against each other. Calls to * this function, ieee80211_rx_ni() and ieee80211_rx_irqsafe() may not be - * mixed for a single hardware. + * mixed for a single hardware. Must not run concurrently with + * ieee80211_tx_status() or ieee80211_tx_status_ni(). * * In process context use instead ieee80211_rx_ni(). * @@ -3059,7 +3060,8 @@ void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb); * (internally defers to a tasklet.) * * Calls to this function, ieee80211_rx() or ieee80211_rx_ni() may not - * be mixed for a single hardware. + * be mixed for a single hardware.Must not run concurrently with + * ieee80211_tx_status() or ieee80211_tx_status_ni(). * * @hw: the hardware this frame came in on * @skb: the buffer to receive, owned by mac80211 after this call @@ -3073,7 +3075,8 @@ void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb); * (internally disables bottom halves). * * Calls to this function, ieee80211_rx() and ieee80211_rx_irqsafe() may - * not be mixed for a single hardware. + * not be mixed for a single hardware. Must not run concurrently with + * ieee80211_tx_status() or ieee80211_tx_status_ni(). * * @hw: the hardware this frame came in on * @skb: the buffer to receive, owned by mac80211 after this call @@ -3196,7 +3199,8 @@ void ieee80211_get_tx_rates(struct ieee80211_vif *vif, * This function may not be called in IRQ context. Calls to this function * for a single hardware must be synchronized against each other. Calls * to this function, ieee80211_tx_status_ni() and ieee80211_tx_status_irqsafe() - * may not be mixed for a single hardware. + * may not be mixed for a single hardware. Must not run concurrently with + * ieee80211_rx() or ieee80211_rx_ni(). * * @hw: the hardware the frame was transmitted by * @skb: the frame that was transmitted, owned by mac80211 after this call diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c index 0d51877efdb7..d3f414fe67e0 100644 --- a/net/mac80211/rate.c +++ b/net/mac80211/rate.c @@ -688,8 +688,15 @@ int rate_control_set_rates(struct ieee80211_hw *hw, struct ieee80211_sta *pubsta, struct ieee80211_sta_rates *rates) { - struct ieee80211_sta_rates *old = rcu_dereference(pubsta->rates); + struct ieee80211_sta_rates *old; + /* + * mac80211 guarantees that this function will not be called + * concurrently, so the following RCU access is safe, even without + * extra locking. This can not be checked easily, so we just set + * the condition to true. + */ + old = rcu_dereference_protected(pubsta->rates, true); rcu_assign_pointer(pubsta->rates, rates); if (old) kfree_rcu(old, rcu_head); |