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mac80211: backport a powersave related fix 

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 40995
lede-17.01
Felix Fietkau 2014-06-03 13:59:43 +00:00
parent eb3a2b12ae
commit 21b0a8d8a4
1 changed files with 225 additions and 2 deletions
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227
package/kernel/mac80211/patches/300-pending_work.patch
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@ -1,3 +1,40 @@
commit 930b0dffd1731f3f418f9132faea720a23b7af61
Author: Johannes Berg <johannes.berg@intel.com>
Date: Tue Jun 3 11:18:47 2014 +0200
mac80211: fix station/driver powersave race
It is currently possible to have a race due to the station PS
unblock work like this:
* station goes to sleep with frames buffered in the driver
* driver blocks wakeup
* station wakes up again
* driver flushes/returns frames, and unblocks, which schedules
the unblock work
* unblock work starts to run, and checks that the station is
awake (i.e. that the WLAN_STA_PS_STA flag isn't set)
* we process a received frame with PM=1, setting the flag again
* ieee80211_sta_ps_deliver_wakeup() runs, delivering all frames
to the driver, and then clearing the WLAN_STA_PS_DRIVER and
WLAN_STA_PS_STA flags
In this scenario, mac80211 will think that the station is awake,
while it really is asleep, and any TX'ed frames should be filtered
by the device (it will know that the station is sleeping) but then
passed to mac80211 again, which will not buffer it either as it
thinks the station is awake, and eventually the packets will be
dropped.
Fix this by moving the clearing of the flags to exactly where we
learn about the situation. This creates a problem of reordering,
so introduce another flag indicating that delivery is being done,
this new flag also queues frames and is cleared only while the
spinlock is held (which the queuing code also holds) so that any
concurrent delivery/TX is handled correctly.
Reported-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
commit 6df35206bc6c1c6aad1d8077df5786b4a7f77873
Author: Felix Fietkau <nbd@openwrt.org>
Date: Fri May 23 19:58:14 2014 +0200
@ -101,7 +138,34 @@ Date: Mon May 19 21:20:49 2014 +0200
if (!budget--)
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -227,6 +227,7 @@ struct sta_info *sta_info_get_by_idx(str
@@ -100,7 +100,8 @@ static void __cleanup_single_sta(struct
struct ps_data *ps;
if (test_sta_flag(sta, WLAN_STA_PS_STA) ||
- test_sta_flag(sta, WLAN_STA_PS_DRIVER)) {
+ test_sta_flag(sta, WLAN_STA_PS_DRIVER) ||
+ test_sta_flag(sta, WLAN_STA_PS_DELIVER)) {
if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
ps = &sdata->bss->ps;
@@ -111,6 +112,7 @@ static void __cleanup_single_sta(struct
clear_sta_flag(sta, WLAN_STA_PS_STA);
clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
+ clear_sta_flag(sta, WLAN_STA_PS_DELIVER);
atomic_dec(&ps->num_sta_ps);
sta_info_recalc_tim(sta);
@@ -125,7 +127,7 @@ static void __cleanup_single_sta(struct
if (ieee80211_vif_is_mesh(&sdata->vif))
mesh_sta_cleanup(sta);
- cancel_work_sync(&sta->drv_unblock_wk);
+ cancel_work_sync(&sta->drv_deliver_wk);
/*
* Destroy aggregation state here. It would be nice to wait for the
@@ -227,6 +229,7 @@ struct sta_info *sta_info_get_by_idx(str
*/
void sta_info_free(struct ieee80211_local *local, struct sta_info *sta)
{
@ -109,7 +173,7 @@ Date: Mon May 19 21:20:49 2014 +0200
int i;
if (sta->rate_ctrl)
@@ -238,6 +239,10 @@ void sta_info_free(struct ieee80211_loca
@@ -238,6 +241,10 @@ void sta_info_free(struct ieee80211_loca
kfree(sta->tx_lat);
}
@ -120,6 +184,104 @@ Date: Mon May 19 21:20:49 2014 +0200
sta_dbg(sta->sdata, "Destroyed STA %pM\n", sta->sta.addr);
kfree(sta);
@@ -252,33 +259,23 @@ static void sta_info_hash_add(struct iee
rcu_assign_pointer(local->sta_hash[STA_HASH(sta->sta.addr)], sta);
}
-static void sta_unblock(struct work_struct *wk)
+static void sta_deliver_ps_frames(struct work_struct *wk)
{
struct sta_info *sta;
- sta = container_of(wk, struct sta_info, drv_unblock_wk);
+ sta = container_of(wk, struct sta_info, drv_deliver_wk);
if (sta->dead)
return;
- if (!test_sta_flag(sta, WLAN_STA_PS_STA)) {
- local_bh_disable();
+ local_bh_disable();
+ if (!test_sta_flag(sta, WLAN_STA_PS_STA))
ieee80211_sta_ps_deliver_wakeup(sta);
- local_bh_enable();
- } else if (test_and_clear_sta_flag(sta, WLAN_STA_PSPOLL)) {
- clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
-
- local_bh_disable();
+ else if (test_and_clear_sta_flag(sta, WLAN_STA_PSPOLL))
ieee80211_sta_ps_deliver_poll_response(sta);
- local_bh_enable();
- } else if (test_and_clear_sta_flag(sta, WLAN_STA_UAPSD)) {
- clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
-
- local_bh_disable();
+ else if (test_and_clear_sta_flag(sta, WLAN_STA_UAPSD))
ieee80211_sta_ps_deliver_uapsd(sta);
- local_bh_enable();
- } else
- clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
+ local_bh_enable();
}
static int sta_prepare_rate_control(struct ieee80211_local *local,
@@ -340,7 +337,7 @@ struct sta_info *sta_info_alloc(struct i
spin_lock_init(&sta->lock);
spin_lock_init(&sta->ps_lock);
- INIT_WORK(&sta->drv_unblock_wk, sta_unblock);
+ INIT_WORK(&sta->drv_deliver_wk, sta_deliver_ps_frames);
INIT_WORK(&sta->ampdu_mlme.work, ieee80211_ba_session_work);
mutex_init(&sta->ampdu_mlme.mtx);
#ifdef CPTCFG_MAC80211_MESH
@@ -1140,8 +1137,15 @@ void ieee80211_sta_ps_deliver_wakeup(str
}
ieee80211_add_pending_skbs(local, &pending);
- clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
- clear_sta_flag(sta, WLAN_STA_PS_STA);
+
+ /* now we're no longer in the deliver code */
+ clear_sta_flag(sta, WLAN_STA_PS_DELIVER);
+
+ /* The station might have polled and then woken up before we responded,
+ * so clear these flags now to avoid them sticking around.
+ */
+ clear_sta_flag(sta, WLAN_STA_PSPOLL);
+ clear_sta_flag(sta, WLAN_STA_UAPSD);
spin_unlock(&sta->ps_lock);
atomic_dec(&ps->num_sta_ps);
@@ -1542,10 +1546,26 @@ void ieee80211_sta_block_awake(struct ie
trace_api_sta_block_awake(sta->local, pubsta, block);
- if (block)
+ if (block) {
set_sta_flag(sta, WLAN_STA_PS_DRIVER);
- else if (test_sta_flag(sta, WLAN_STA_PS_DRIVER))
- ieee80211_queue_work(hw, &sta->drv_unblock_wk);
+ return;
+ }
+
+ if (!test_sta_flag(sta, WLAN_STA_PS_DRIVER))
+ return;
+
+ if (!test_sta_flag(sta, WLAN_STA_PS_STA)) {
+ set_sta_flag(sta, WLAN_STA_PS_DELIVER);
+ clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
+ ieee80211_queue_work(hw, &sta->drv_deliver_wk);
+ } else if (test_sta_flag(sta, WLAN_STA_PSPOLL) ||
+ test_sta_flag(sta, WLAN_STA_UAPSD)) {
+ /* must be asleep in this case */
+ clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
+ ieee80211_queue_work(hw, &sta->drv_deliver_wk);
+ } else {
+ clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
+ }
}
EXPORT_SYMBOL(ieee80211_sta_block_awake);
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -541,6 +541,23 @@ static void ieee80211_tx_latency_end_msr
@ -161,3 +323,64 @@ Date: Mon May 19 21:20:49 2014 +0200
}
}
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1107,6 +1107,8 @@ static void sta_ps_end(struct sta_info *
return;
}
+ set_sta_flag(sta, WLAN_STA_PS_DELIVER);
+ clear_sta_flag(sta, WLAN_STA_PS_STA);
ieee80211_sta_ps_deliver_wakeup(sta);
}
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -82,6 +82,7 @@ enum ieee80211_sta_info_flags {
WLAN_STA_TOFFSET_KNOWN,
WLAN_STA_MPSP_OWNER,
WLAN_STA_MPSP_RECIPIENT,
+ WLAN_STA_PS_DELIVER,
};
#define ADDBA_RESP_INTERVAL HZ
@@ -265,7 +266,7 @@ struct ieee80211_tx_latency_stat {
* @last_rx_rate_vht_nss: rx status nss of last data packet
* @lock: used for locking all fields that require locking, see comments
* in the header file.
- * @drv_unblock_wk: used for driver PS unblocking
+ * @drv_deliver_wk: used for delivering frames after driver PS unblocking
* @listen_interval: listen interval of this station, when we're acting as AP
* @_flags: STA flags, see &enum ieee80211_sta_info_flags, do not use directly
* @ps_lock: used for powersave (when mac80211 is the AP) related locking
@@ -345,7 +346,7 @@ struct sta_info {
void *rate_ctrl_priv;
spinlock_t lock;
- struct work_struct drv_unblock_wk;
+ struct work_struct drv_deliver_wk;
u16 listen_interval;
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -469,7 +469,8 @@ ieee80211_tx_h_unicast_ps_buf(struct iee
return TX_CONTINUE;
if (unlikely((test_sta_flag(sta, WLAN_STA_PS_STA) ||
- test_sta_flag(sta, WLAN_STA_PS_DRIVER)) &&
+ test_sta_flag(sta, WLAN_STA_PS_DRIVER) ||
+ test_sta_flag(sta, WLAN_STA_PS_DELIVER)) &&
!(info->flags & IEEE80211_TX_CTL_NO_PS_BUFFER))) {
int ac = skb_get_queue_mapping(tx->skb);
@@ -486,7 +487,8 @@ ieee80211_tx_h_unicast_ps_buf(struct iee
* ahead and Tx the packet.
*/
if (!test_sta_flag(sta, WLAN_STA_PS_STA) &&
- !test_sta_flag(sta, WLAN_STA_PS_DRIVER)) {
+ !test_sta_flag(sta, WLAN_STA_PS_DRIVER) &&
+ !test_sta_flag(sta, WLAN_STA_PS_DELIVER)) {
spin_unlock(&sta->ps_lock);
return TX_CONTINUE;
}