From 8b305780ed0c49a49c6bd58a4372fd6b22a5a71e Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 20 Mar 2013 22:25:17 +0100 Subject: mac80211: fix virtual monitor interface locking The virtual monitor interface has a locking issue, it calls into the channel context code with the iflist mutex held which isn't allowed since it is usually acquired the other way around. The mutex is still required for the interface iteration, but need not be held across the channel calls. Signed-off-by: Johannes Berg --- net/mac80211/iface.c | 35 +++++++++++++++++++---------------- 1 file changed, 19 insertions(+), 16 deletions(-) (limited to 'net/mac80211/iface.c') diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index baaa8608e52d..3bfe2612c8c2 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -349,21 +349,19 @@ static void ieee80211_set_default_queues(struct ieee80211_sub_if_data *sdata) static int ieee80211_add_virtual_monitor(struct ieee80211_local *local) { struct ieee80211_sub_if_data *sdata; - int ret = 0; + int ret; if (!(local->hw.flags & IEEE80211_HW_WANT_MONITOR_VIF)) return 0; - mutex_lock(&local->iflist_mtx); + ASSERT_RTNL(); if (local->monitor_sdata) - goto out_unlock; + return 0; sdata = kzalloc(sizeof(*sdata) + local->hw.vif_data_size, GFP_KERNEL); - if (!sdata) { - ret = -ENOMEM; - goto out_unlock; - } + if (!sdata) + return -ENOMEM; /* set up data */ sdata->local = local; @@ -377,13 +375,13 @@ static int ieee80211_add_virtual_monitor(struct ieee80211_local *local) if (WARN_ON(ret)) { /* ok .. stupid driver, it asked for this! */ kfree(sdata); - goto out_unlock; + return ret; } ret = ieee80211_check_queues(sdata); if (ret) { kfree(sdata); - goto out_unlock; + return ret; } ret = ieee80211_vif_use_channel(sdata, &local->monitor_chandef, @@ -391,13 +389,14 @@ static int ieee80211_add_virtual_monitor(struct ieee80211_local *local) if (ret) { drv_remove_interface(local, sdata); kfree(sdata); - goto out_unlock; + return ret; } + mutex_lock(&local->iflist_mtx); rcu_assign_pointer(local->monitor_sdata, sdata); - out_unlock: mutex_unlock(&local->iflist_mtx); - return ret; + + return 0; } static void ieee80211_del_virtual_monitor(struct ieee80211_local *local) @@ -407,14 +406,20 @@ static void ieee80211_del_virtual_monitor(struct ieee80211_local *local) if (!(local->hw.flags & IEEE80211_HW_WANT_MONITOR_VIF)) return; + ASSERT_RTNL(); + mutex_lock(&local->iflist_mtx); sdata = rcu_dereference_protected(local->monitor_sdata, lockdep_is_held(&local->iflist_mtx)); - if (!sdata) - goto out_unlock; + if (!sdata) { + mutex_unlock(&local->iflist_mtx); + return; + } rcu_assign_pointer(local->monitor_sdata, NULL); + mutex_unlock(&local->iflist_mtx); + synchronize_net(); ieee80211_vif_release_channel(sdata); @@ -422,8 +427,6 @@ static void ieee80211_del_virtual_monitor(struct ieee80211_local *local) drv_remove_interface(local, sdata); kfree(sdata); - out_unlock: - mutex_unlock(&local->iflist_mtx); } /* -- cgit v1.2.3 From 382a103b2b528a3085cde4ac56fc69d92a828b72 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 22 Mar 2013 22:30:09 +0100 Subject: mac80211: fix idle handling sequence Corey Richardson reported that my idle handling cleanup (commit fd0f979a1b, "mac80211: simplify idle handling") broke ath9k_htc. The reason appears to be that it wants to go out of idle before switching channels. To fix it, reimplement that sequence. Reported-by: Corey Richardson Signed-off-by: Johannes Berg --- net/mac80211/chan.c | 17 ++++++++++++++--- net/mac80211/ieee80211_i.h | 1 + net/mac80211/iface.c | 2 +- 3 files changed, 16 insertions(+), 4 deletions(-) (limited to 'net/mac80211/iface.c') diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c index 78c0d90dd641..931be419ab5a 100644 --- a/net/mac80211/chan.c +++ b/net/mac80211/chan.c @@ -63,6 +63,7 @@ ieee80211_new_chanctx(struct ieee80211_local *local, enum ieee80211_chanctx_mode mode) { struct ieee80211_chanctx *ctx; + u32 changed; int err; lockdep_assert_held(&local->chanctx_mtx); @@ -76,6 +77,13 @@ ieee80211_new_chanctx(struct ieee80211_local *local, ctx->conf.rx_chains_dynamic = 1; ctx->mode = mode; + /* acquire mutex to prevent idle from changing */ + mutex_lock(&local->mtx); + /* turn idle off *before* setting channel -- some drivers need that */ + changed = ieee80211_idle_off(local); + if (changed) + ieee80211_hw_config(local, changed); + if (!local->use_chanctx) { local->_oper_channel_type = cfg80211_get_chandef_type(chandef); @@ -85,14 +93,17 @@ ieee80211_new_chanctx(struct ieee80211_local *local, err = drv_add_chanctx(local, ctx); if (err) { kfree(ctx); - return ERR_PTR(err); + ctx = ERR_PTR(err); + + ieee80211_recalc_idle(local); + goto out; } } + /* and keep the mutex held until the new chanctx is on the list */ list_add_rcu(&ctx->list, &local->chanctx_list); - mutex_lock(&local->mtx); - ieee80211_recalc_idle(local); + out: mutex_unlock(&local->mtx); return ctx; diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 7bdefd901f9d..5672533a0832 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -1362,6 +1362,7 @@ int ieee80211_if_change_type(struct ieee80211_sub_if_data *sdata, enum nl80211_iftype type); void ieee80211_if_remove(struct ieee80211_sub_if_data *sdata); void ieee80211_remove_interfaces(struct ieee80211_local *local); +u32 ieee80211_idle_off(struct ieee80211_local *local); void ieee80211_recalc_idle(struct ieee80211_local *local); void ieee80211_adjust_monitor_flags(struct ieee80211_sub_if_data *sdata, const int offset); diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 3bfe2612c8c2..58150f877ec3 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -78,7 +78,7 @@ void ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata) ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_TXPOWER); } -static u32 ieee80211_idle_off(struct ieee80211_local *local) +u32 ieee80211_idle_off(struct ieee80211_local *local) { if (!(local->hw.conf.flags & IEEE80211_CONF_IDLE)) return 0; -- cgit v1.2.3