126 lines
4.1 KiB
Diff
126 lines
4.1 KiB
Diff
From: Johannes Berg <johannes.berg@intel.com>
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Date: Wed, 11 Mar 2015 09:14:15 +0100
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Subject: [PATCH] mac80211: lock rate control
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Both minstrel (reported by Sven Eckelmann) and the iwlwifi rate
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control aren't properly taking concurrency into account. It's
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likely that the same is true for other rate control algorithms.
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In the case of minstrel this manifests itself in crashes when an
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update and other data access are run concurrently, for example
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when the stations change bandwidth or similar. In iwlwifi, this
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can cause firmware crashes.
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Since fixing all rate control algorithms will be very difficult,
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just provide locking for invocations. This protects the internal
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data structures the algorithms maintain.
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I've manipulated hostapd to test this, by having it change its
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advertised bandwidth roughly ever 150ms. At the same time, I'm
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running a flood ping between the client and the AP, which causes
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this race of update vs. get_rate/status to easily happen on the
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client. With this change, the system survives this test.
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Reported-by: Sven Eckelmann <sven@open-mesh.com>
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Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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---
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--- a/net/mac80211/rate.c
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+++ b/net/mac80211/rate.c
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@@ -683,7 +683,13 @@ void rate_control_get_rate(struct ieee80
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if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
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return;
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- ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
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+ if (ista) {
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+ spin_lock_bh(&sta->rate_ctrl_lock);
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+ ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
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+ spin_unlock_bh(&sta->rate_ctrl_lock);
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+ } else {
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+ ref->ops->get_rate(ref->priv, NULL, NULL, txrc);
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+ }
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if (sdata->local->hw.flags & IEEE80211_HW_SUPPORTS_RC_TABLE)
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return;
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--- a/net/mac80211/rate.h
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+++ b/net/mac80211/rate.h
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@@ -42,10 +42,12 @@ static inline void rate_control_tx_statu
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if (!ref || !test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
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return;
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+ spin_lock_bh(&sta->rate_ctrl_lock);
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if (ref->ops->tx_status)
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ref->ops->tx_status(ref->priv, sband, ista, priv_sta, skb);
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else
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ref->ops->tx_status_noskb(ref->priv, sband, ista, priv_sta, info);
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+ spin_unlock_bh(&sta->rate_ctrl_lock);
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}
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static inline void
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@@ -64,7 +66,9 @@ rate_control_tx_status_noskb(struct ieee
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if (WARN_ON_ONCE(!ref->ops->tx_status_noskb))
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return;
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+ spin_lock_bh(&sta->rate_ctrl_lock);
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ref->ops->tx_status_noskb(ref->priv, sband, ista, priv_sta, info);
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+ spin_unlock_bh(&sta->rate_ctrl_lock);
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}
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static inline void rate_control_rate_init(struct sta_info *sta)
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@@ -91,8 +95,10 @@ static inline void rate_control_rate_ini
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sband = local->hw.wiphy->bands[chanctx_conf->def.chan->band];
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+ spin_lock_bh(&sta->rate_ctrl_lock);
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ref->ops->rate_init(ref->priv, sband, &chanctx_conf->def, ista,
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priv_sta);
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+ spin_unlock_bh(&sta->rate_ctrl_lock);
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rcu_read_unlock();
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set_sta_flag(sta, WLAN_STA_RATE_CONTROL);
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}
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@@ -115,18 +121,20 @@ static inline void rate_control_rate_upd
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return;
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}
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+ spin_lock_bh(&sta->rate_ctrl_lock);
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ref->ops->rate_update(ref->priv, sband, &chanctx_conf->def,
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ista, priv_sta, changed);
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+ spin_unlock_bh(&sta->rate_ctrl_lock);
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rcu_read_unlock();
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}
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drv_sta_rc_update(local, sta->sdata, &sta->sta, changed);
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}
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static inline void *rate_control_alloc_sta(struct rate_control_ref *ref,
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- struct ieee80211_sta *sta,
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- gfp_t gfp)
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+ struct sta_info *sta, gfp_t gfp)
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{
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- return ref->ops->alloc_sta(ref->priv, sta, gfp);
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+ spin_lock_init(&sta->rate_ctrl_lock);
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+ return ref->ops->alloc_sta(ref->priv, &sta->sta, gfp);
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}
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static inline void rate_control_free_sta(struct sta_info *sta)
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--- a/net/mac80211/sta_info.c
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+++ b/net/mac80211/sta_info.c
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@@ -280,7 +280,7 @@ static int sta_prepare_rate_control(stru
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sta->rate_ctrl = local->rate_ctrl;
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sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl,
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- &sta->sta, gfp);
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+ sta, gfp);
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if (!sta->rate_ctrl_priv)
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return -ENOMEM;
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--- a/net/mac80211/sta_info.h
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+++ b/net/mac80211/sta_info.h
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@@ -349,6 +349,7 @@ struct sta_info {
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u8 ptk_idx;
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struct rate_control_ref *rate_ctrl;
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void *rate_ctrl_priv;
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+ spinlock_t rate_ctrl_lock;
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spinlock_t lock;
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struct work_struct drv_deliver_wk;
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