There is a circular locking dependency when configuring the
hardware ARP filters on association, occurring when flushing the mac80211
workqueue. This is what happens:
[ 92.026800] =======================================================
[ 92.030507] [ INFO: possible circular locking dependency detected ]
[ 92.030507] 2.6.34-04781-g2b2c009 #85
[ 92.030507] -------------------------------------------------------
[ 92.030507] modprobe/5225 is trying to acquire lock:
[ 92.030507] ((wiphy_name(local->hw.wiphy))){+.+.+.}, at: [<ffffffff8105b5c0>] flush_workq
ueue+0x0/0xb0
[ 92.030507]
[ 92.030507] but task is already holding lock:
[ 92.030507] (rtnl_mutex){+.+.+.}, at: [<ffffffff812b9ce2>] rtnl_lock+0x12/0x20
[ 92.030507]
[ 92.030507] which lock already depends on the new lock.
[ 92.030507]
[ 92.030507]
[ 92.030507] the existing dependency chain (in reverse order) is:
[ 92.030507]
[ 92.030507] -> #2 (rtnl_mutex){+.+.+.}:
[ 92.030507] [<ffffffff810761fb>] lock_acquire+0xdb/0x110
[ 92.030507] [<ffffffff81341754>] mutex_lock_nested+0x44/0x300
[ 92.030507] [<ffffffff812b9ce2>] rtnl_lock+0x12/0x20
[ 92.030507] [<ffffffffa022d47c>] ieee80211_assoc_done+0x6c/0xe0 [mac80211]
[ 92.030507] [<ffffffffa022f2ad>] ieee80211_work_work+0x31d/0x1280 [mac80211]
[ 92.030507] -> #1 ((&local->work_work)){+.+.+.}:
[ 92.030507] [<ffffffff810761fb>] lock_acquire+0xdb/0x110
[ 92.030507] [<ffffffff8105a51a>] worker_thread+0x22a/0x370
[ 92.030507] [<ffffffff8105ecc6>] kthread+0x96/0xb0
[ 92.030507] [<ffffffff81003a94>] kernel_thread_helper+0x4/0x10
[ 92.030507]
[ 92.030507] -> #0 ((wiphy_name(local->hw.wiphy))){+.+.+.}:
[ 92.030507] [<ffffffff81075fdc>] __lock_acquire+0x1c0c/0x1d50
[ 92.030507] [<ffffffff810761fb>] lock_acquire+0xdb/0x110
[ 92.030507] [<ffffffff8105b60e>] flush_workqueue+0x4e/0xb0
[ 92.030507] [<ffffffffa023ff7b>] ieee80211_stop_device+0x2b/0xb0 [mac80211]
[ 92.030507] [<ffffffffa0231635>] ieee80211_stop+0x3e5/0x680 [mac80211]
The locking in this case is quite complex. Fix the problem by rewriting the
way the hardware ARP filter list is handled - i.e. make a copy of the address
list to the bss_conf struct, and provide that list to the hardware driver
when needed.
Additionally, this patch ensures that hardware ARP filtering is not enabled
when promiscuous mode is set.
Reported-by: Reinette Chatre <[email protected]>
Signed-off-by: Juuso Oikarinen <[email protected]>
---
v3: - queue reconfig filter work to kernel default wq instead of mac80211 wq
- initialize arp_filter_state to "true" in if_add
include/net/mac80211.h | 34 +++++----
net/mac80211/driver-ops.h | 17 -----
net/mac80211/driver-trace.h | 25 -------
net/mac80211/ieee80211_i.h | 2 +
net/mac80211/iface.c | 8 ++-
net/mac80211/main.c | 166 +++++++++++++++++++++++++++++--------------
net/mac80211/mlme.c | 39 ++++++----
7 files changed, 164 insertions(+), 127 deletions(-)
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index e3c1d47..f409d00 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -19,7 +19,6 @@
#include <linux/wireless.h>
#include <linux/device.h>
#include <linux/ieee80211.h>
-#include <linux/inetdevice.h>
#include <net/cfg80211.h>
/**
@@ -147,6 +146,7 @@ struct ieee80211_low_level_stats {
* enabled/disabled (beaconing modes)
* @BSS_CHANGED_CQM: Connection quality monitor config changed
* @BSS_CHANGED_IBSS: IBSS join status changed
+ * @BSS_CHANGED_ARP_FILTER: Hardware ARP filter address list or state changed.
*/
enum ieee80211_bss_change {
BSS_CHANGED_ASSOC = 1<<0,
@@ -161,10 +161,18 @@ enum ieee80211_bss_change {
BSS_CHANGED_BEACON_ENABLED = 1<<9,
BSS_CHANGED_CQM = 1<<10,
BSS_CHANGED_IBSS = 1<<11,
+ BSS_CHANGED_ARP_FILTER = 1<<12,
/* when adding here, make sure to change ieee80211_reconfig */
};
+/*
+ * The maximum number of IPv4 addresses listed for ARP filtering. If the number
+ * of addresses for an interface increase beyond this value, hardware ARP
+ * filtering will be disabled.
+ */
+#define IEEE80211_BSS_ARP_ADDR_LIST_LEN 4
+
/**
* struct ieee80211_bss_conf - holds the BSS's changing parameters
*
@@ -200,6 +208,14 @@ enum ieee80211_bss_change {
* @cqm_rssi_thold: Connection quality monitor RSSI threshold, a zero value
* implies disabled
* @cqm_rssi_hyst: Connection quality monitor RSSI hysteresis
+ * @arp_addr_list: List of IPv4 addresses for hardware ARP filtering. The
+ * may filter ARP queries targeted for other addresses than listed here.
+ * The driver must allow ARP queries targeted for all address listed here
+ * to pass through. An empty list implies no ARP queries need to pass.
+ * @arp_addr_cnt: Number of addresses currently on the list.
+ * @arp_filter_enabled: Enable ARP filtering - if enabled, the hardware may
+ * filter ARP queries based on the @arp_addr_list, if disabled, the
+ * hardware must not perform any ARP filtering.
*/
struct ieee80211_bss_conf {
const u8 *bssid;
@@ -220,6 +236,9 @@ struct ieee80211_bss_conf {
s32 cqm_rssi_thold;
u32 cqm_rssi_hyst;
enum nl80211_channel_type channel_type;
+ __be32 arp_addr_list[IEEE80211_BSS_ARP_ADDR_LIST_LEN];
+ u8 arp_addr_cnt;
+ bool arp_filter_enabled;
};
/**
@@ -1529,16 +1548,6 @@ enum ieee80211_ampdu_mlme_action {
* of the bss parameters has changed when a call is made. The callback
* can sleep.
*
- * @configure_arp_filter: Configuration function for hardware ARP query filter.
- * This function is called with all the IP addresses configured to the
- * interface as argument - all ARP queries targeted to any of these
- * addresses must pass through. If the hardware filter does not support
- * enought addresses, hardware filtering must be disabled. The ifa_list
- * argument may be NULL, indicating that filtering must be disabled.
- * This function is called upon association complete with current
- * address(es), and while associated whenever the IP address(es) change.
- * The callback can sleep.
- *
* @prepare_multicast: Prepare for multicast filter configuration.
* This callback is optional, and its return value is passed
* to configure_filter(). This callback must be atomic.
@@ -1678,9 +1687,6 @@ struct ieee80211_ops {
struct ieee80211_vif *vif,
struct ieee80211_bss_conf *info,
u32 changed);
- int (*configure_arp_filter)(struct ieee80211_hw *hw,
- struct ieee80211_vif *vif,
- struct in_ifaddr *ifa_list);
u64 (*prepare_multicast)(struct ieee80211_hw *hw,
struct netdev_hw_addr_list *mc_list);
void (*configure_filter)(struct ieee80211_hw *hw,
diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index d1139e4..bbea3bc 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -83,23 +83,6 @@ static inline void drv_bss_info_changed(struct ieee80211_local *local,
trace_drv_bss_info_changed(local, sdata, info, changed);
}
-struct in_ifaddr;
-static inline int drv_configure_arp_filter(struct ieee80211_local *local,
- struct ieee80211_vif *vif,
- struct in_ifaddr *ifa_list)
-{
- int ret = 0;
-
- might_sleep();
-
- if (local->ops->configure_arp_filter)
- ret = local->ops->configure_arp_filter(&local->hw, vif,
- ifa_list);
-
- trace_drv_configure_arp_filter(local, vif_to_sdata(vif), ifa_list, ret);
- return ret;
-}
-
static inline u64 drv_prepare_multicast(struct ieee80211_local *local,
struct netdev_hw_addr_list *mc_list)
{
diff --git a/net/mac80211/driver-trace.h b/net/mac80211/driver-trace.h
index 6b90630..1e293df 100644
--- a/net/mac80211/driver-trace.h
+++ b/net/mac80211/driver-trace.h
@@ -219,31 +219,6 @@ TRACE_EVENT(drv_bss_info_changed,
)
);
-TRACE_EVENT(drv_configure_arp_filter,
- TP_PROTO(struct ieee80211_local *local,
- struct ieee80211_sub_if_data *sdata,
- struct in_ifaddr *ifa_list, int ret),
-
- TP_ARGS(local, sdata, ifa_list, ret),
-
- TP_STRUCT__entry(
- LOCAL_ENTRY
- VIF_ENTRY
- __field(int, ret)
- ),
-
- TP_fast_assign(
- LOCAL_ASSIGN;
- VIF_ASSIGN;
- __entry->ret = ret;
- ),
-
- TP_printk(
- VIF_PR_FMT LOCAL_PR_FMT " ret:%d",
- VIF_PR_ARG, LOCAL_PR_ARG, __entry->ret
- )
-);
-
TRACE_EVENT(drv_prepare_multicast,
TP_PROTO(struct ieee80211_local *local, int mc_count, u64 ret),
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 4d3883e..79e366e 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -517,6 +517,8 @@ struct ieee80211_sub_if_data {
u16 sequence_number;
+ bool arp_filter_state;
+
/*
* AP this belongs to: self in AP mode and
* corresponding AP in VLAN mode, NULL for
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 1afa9ec..4b64d85 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -588,7 +588,12 @@ static void ieee80211_set_multicast_list(struct net_device *dev)
spin_lock_bh(&local->filter_lock);
__hw_addr_sync(&local->mc_list, &dev->mc, dev->addr_len);
spin_unlock_bh(&local->filter_lock);
- ieee80211_queue_work(&local->hw, &local->reconfig_filter);
+
+ /*
+ * This work cannot be queued in the mac80211 workqueue as it requires
+ * rtnl_lock().
+ */
+ schedule_work(&local->reconfig_filter);
}
/*
@@ -959,6 +964,7 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name,
sdata->wdev.wiphy = local->hw.wiphy;
sdata->local = local;
sdata->dev = ndev;
+ sdata->arp_filter_state = true;
for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
skb_queue_head_init(&sdata->fragments[i].skb_list);
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 5706156..b64066c 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -20,6 +20,7 @@
#include <linux/rtnetlink.h>
#include <linux/bitmap.h>
#include <linux/pm_qos_params.h>
+#include <linux/inetdevice.h>
#include <net/net_namespace.h>
#include <net/cfg80211.h>
@@ -84,12 +85,123 @@ void ieee80211_configure_filter(struct ieee80211_local *local)
local->filter_flags = new_flags & ~(1<<31);
}
+#ifdef CONFIG_INET
+static void ieee80211_reconfig_arp_filter(struct ieee80211_local *local)
+{
+ struct ieee80211_sub_if_data *sdata;
+ struct ieee80211_if_managed *ifmgd;
+ struct ieee80211_bss_conf *bss_conf;
+ u32 changed;
+ bool promisc;
+ bool old_state, new_state;
+
+ /* Check ARP filtering state for each interface */
+ rtnl_lock();
+ list_for_each_entry(sdata, &local->interfaces, list) {
+ if (sdata->vif.type != NL80211_IFTYPE_STATION)
+ continue;
+
+ ifmgd = &sdata->u.mgd;
+ mutex_lock(&ifmgd->mtx);
+ if (!ifmgd->associated) {
+ mutex_unlock(&ifmgd->mtx);
+ continue;
+ }
+
+ bss_conf = &sdata->vif.bss_conf;
+
+ old_state = !!(bss_conf->arp_filter_enabled);
+
+ promisc = sdata->flags & IEEE80211_SDATA_PROMISC;
+ new_state = !promisc && sdata->arp_filter_state;
+ bss_conf->arp_filter_enabled = new_state;
+
+ if (old_state != new_state) {
+ changed = BSS_CHANGED_ARP_FILTER;
+ ieee80211_bss_info_change_notify(sdata, changed);
+ }
+
+ mutex_unlock(&ifmgd->mtx);
+ }
+ rtnl_unlock();
+}
+
+static int ieee80211_ifa_changed(struct notifier_block *nb,
+ unsigned long data, void *arg)
+{
+ struct in_ifaddr *ifa = arg;
+ struct ieee80211_local *local =
+ container_of(nb, struct ieee80211_local,
+ ifa_notifier);
+ struct net_device *ndev = ifa->ifa_dev->dev;
+ struct wireless_dev *wdev = ndev->ieee80211_ptr;
+ struct in_device *idev;
+ struct ieee80211_sub_if_data *sdata;
+ struct ieee80211_bss_conf *bss_conf;
+ struct ieee80211_if_managed *ifmgd;
+ int c = 0;
+
+ /* Make sure it's our interface that got changed */
+ if (!wdev)
+ return NOTIFY_DONE;
+
+ if (wdev->wiphy != local->hw.wiphy)
+ return NOTIFY_DONE;
+
+ sdata = IEEE80211_DEV_TO_SUB_IF(ndev);
+ bss_conf = &sdata->vif.bss_conf;
+
+ /* ARP filtering is only supported in managed mode */
+ if (sdata->vif.type != NL80211_IFTYPE_STATION)
+ return NOTIFY_DONE;
+
+ idev = sdata->dev->ip_ptr;
+ if (!idev)
+ return NOTIFY_DONE;
+
+ ifmgd = &sdata->u.mgd;
+ mutex_lock(&ifmgd->mtx);
+
+ /* Copy the addresses to the bss_conf list */
+ ifa = idev->ifa_list;
+ while (c < IEEE80211_BSS_ARP_ADDR_LIST_LEN && ifa) {
+ bss_conf->arp_addr_list[c] = ifa->ifa_address;
+ ifa = ifa->ifa_next;
+ c++;
+ }
+
+ /* If not all addresses fit the list, disable filtering */
+ if (ifa) {
+ sdata->arp_filter_state = false;
+ c = 0;
+ } else {
+ sdata->arp_filter_state = true;
+ }
+ bss_conf->arp_addr_cnt = c;
+
+ /* Configure driver only if associated and not in promiscuous mode */
+ if (ifmgd->associated && !(sdata->flags & IEEE80211_SDATA_PROMISC)) {
+ bss_conf->arp_filter_enabled = sdata->arp_filter_state;
+ ieee80211_bss_info_change_notify(sdata,
+ BSS_CHANGED_ARP_FILTER);
+ }
+
+ mutex_unlock(&ifmgd->mtx);
+
+ return NOTIFY_DONE;
+}
+#endif
+
static void ieee80211_reconfig_filter(struct work_struct *work)
{
struct ieee80211_local *local =
container_of(work, struct ieee80211_local, reconfig_filter);
ieee80211_configure_filter(local);
+
+#ifdef CONFIG_INET
+ ieee80211_reconfig_arp_filter(local);
+#endif
}
int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
@@ -329,60 +441,6 @@ static void ieee80211_recalc_smps_work(struct work_struct *work)
mutex_unlock(&local->iflist_mtx);
}
-#ifdef CONFIG_INET
-int ieee80211_set_arp_filter(struct ieee80211_sub_if_data *sdata)
-{
- struct in_device *idev;
- int ret = 0;
-
- BUG_ON(!sdata);
- ASSERT_RTNL();
-
- idev = sdata->dev->ip_ptr;
- if (!idev)
- return 0;
-
- ret = drv_configure_arp_filter(sdata->local, &sdata->vif,
- idev->ifa_list);
- return ret;
-}
-
-static int ieee80211_ifa_changed(struct notifier_block *nb,
- unsigned long data, void *arg)
-{
- struct in_ifaddr *ifa = arg;
- struct ieee80211_local *local =
- container_of(nb, struct ieee80211_local,
- ifa_notifier);
- struct net_device *ndev = ifa->ifa_dev->dev;
- struct wireless_dev *wdev = ndev->ieee80211_ptr;
- struct ieee80211_sub_if_data *sdata;
- struct ieee80211_if_managed *ifmgd;
-
- /* Make sure it's our interface that got changed */
- if (!wdev)
- return NOTIFY_DONE;
-
- if (wdev->wiphy != local->hw.wiphy)
- return NOTIFY_DONE;
-
- /* We are concerned about IP addresses only when associated */
- sdata = IEEE80211_DEV_TO_SUB_IF(ndev);
-
- /* ARP filtering is only supported in managed mode */
- if (sdata->vif.type != NL80211_IFTYPE_STATION)
- return NOTIFY_DONE;
-
- ifmgd = &sdata->u.mgd;
- mutex_lock(&ifmgd->mtx);
- if (ifmgd->associated)
- ieee80211_set_arp_filter(sdata);
- mutex_unlock(&ifmgd->mtx);
-
- return NOTIFY_DONE;
-}
-#endif
-
struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
const struct ieee80211_ops *ops)
{
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index ac68c41..d328e9a 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -806,11 +806,12 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
{
struct ieee80211_bss *bss = (void *)cbss->priv;
struct ieee80211_local *local = sdata->local;
+ struct ieee80211_bss_conf *bss_conf = &sdata->vif.bss_conf;
bss_info_changed |= BSS_CHANGED_ASSOC;
/* set timing information */
- sdata->vif.bss_conf.beacon_int = cbss->beacon_interval;
- sdata->vif.bss_conf.timestamp = cbss->tsf;
+ bss_conf->beacon_int = cbss->beacon_interval;
+ bss_conf->timestamp = cbss->tsf;
bss_info_changed |= BSS_CHANGED_BEACON_INT;
bss_info_changed |= ieee80211_handle_bss_capability(sdata,
@@ -835,7 +836,7 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
ieee80211_led_assoc(local, 1);
- sdata->vif.bss_conf.assoc = 1;
+ bss_conf->assoc = 1;
/*
* For now just always ask the driver to update the basic rateset
* when we have associated, we aren't checking whether it actually
@@ -848,9 +849,18 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
/* Tell the driver to monitor connection quality (if supported) */
if ((local->hw.flags & IEEE80211_HW_SUPPORTS_CQM_RSSI) &&
- sdata->vif.bss_conf.cqm_rssi_thold)
+ bss_conf->cqm_rssi_thold)
bss_info_changed |= BSS_CHANGED_CQM;
+#ifdef CONFIG_INET
+ /* Enable ARP filtering unless in promisc mode */
+ if (!(sdata->flags & IEEE80211_SDATA_PROMISC) &&
+ bss_conf->arp_filter_enabled != sdata->arp_filter_state) {
+ bss_conf->arp_filter_enabled = sdata->arp_filter_state;
+ bss_info_changed |= BSS_CHANGED_ARP_FILTER;
+ }
+#endif
+
ieee80211_bss_info_change_notify(sdata, bss_info_changed);
mutex_lock(&local->iflist_mtx);
@@ -932,6 +942,13 @@ static void ieee80211_set_disassoc(struct ieee80211_sub_if_data *sdata,
ieee80211_hw_config(local, config_changed);
+ /* Disable ARP filtering */
+ if (sdata->vif.bss_conf.arp_filter_enabled) {
+ sdata->vif.bss_conf.arp_filter_enabled = false;
+ changed |= BSS_CHANGED_ARP_FILTER;
+ }
+
+
/* The BSSID (not really interesting) and HT changed */
changed |= BSS_CHANGED_BSSID | BSS_CHANGED_HT;
ieee80211_bss_info_change_notify(sdata, changed);
@@ -2116,19 +2133,9 @@ static enum work_done_result ieee80211_assoc_done(struct ieee80211_work *wk,
cfg80211_send_assoc_timeout(wk->sdata->dev,
wk->filter_ta);
return WORK_DONE_DESTROY;
-#ifdef CONFIG_INET
- } else {
- mutex_unlock(&wk->sdata->u.mgd.mtx);
-
- /*
- * configure ARP filter IP addresses to the driver,
- * intentionally outside the mgd mutex.
- */
- rtnl_lock();
- ieee80211_set_arp_filter(wk->sdata);
- rtnl_unlock();
-#endif
}
+
+ mutex_unlock(&wk->sdata->u.mgd.mtx);
}
cfg80211_send_rx_assoc(wk->sdata->dev, skb->data, skb->len);
--
1.6.3.3
On Wed, 2010-06-09 at 11:50 +0300, Juuso Oikarinen wrote:
> On Wed, 2010-06-09 at 09:32 +0200, ext Johannes Berg wrote:
> > On Wed, 2010-06-09 at 09:50 +0300, Juuso Oikarinen wrote:
> >
> > > v3: - queue reconfig filter work to kernel default wq instead of mac80211 wq
> >
> > I think it would make more sense to use a different lock instead, like
> > the iflist mutex?
>
> Yeah had that originally, but apparently the iflist mutex is acquired
> *after* the mgd mutex in some places of the code, especially all around
> mlme.c, and here I would have to acquire them in reverse order. So I
> changed to the rtnl lock.
Ah, right.
However I'm a bit worried that making this workqueue change will allow
the filter reconfigure to cross with suspend, which might mean it could
execute after the device is suspended?
johannes
On Wed, 2010-06-09 at 09:50 +0300, Juuso Oikarinen wrote:
> v3: - queue reconfig filter work to kernel default wq instead of mac80211 wq
I think it would make more sense to use a different lock instead, like
the iflist mutex?
johannes
On Wed, 2010-06-09 at 12:08 +0300, Juuso Oikarinen wrote:
> > However I'm a bit worried that making this workqueue change will allow
> > the filter reconfigure to cross with suspend, which might mean it could
> > execute after the device is suspended?
>
> Ah yes. That's an obvious side-effect. I wonder if it would be solved by
> flushing this particular work along with the mac80211 wq in the suspend
> call, or would the implications then just move further?
But that's under rtnl.
> Apart from the above, I'm out of ideas. If this is getting too complex,
> I'll need to revert back to the patch that does not take into account
> the promisc mode.
probably the best choice for now at least
johannes
On Wed, 2010-06-09 at 09:32 +0200, ext Johannes Berg wrote:
> On Wed, 2010-06-09 at 09:50 +0300, Juuso Oikarinen wrote:
>
> > v3: - queue reconfig filter work to kernel default wq instead of mac80211 wq
>
> I think it would make more sense to use a different lock instead, like
> the iflist mutex?
Yeah had that originally, but apparently the iflist mutex is acquired
*after* the mgd mutex in some places of the code, especially all around
mlme.c, and here I would have to acquire them in reverse order. So I
changed to the rtnl lock.
-Juuso
> johannes
>
On Wed, 2010-06-09 at 10:54 +0200, ext Johannes Berg wrote:
> On Wed, 2010-06-09 at 11:50 +0300, Juuso Oikarinen wrote:
> > On Wed, 2010-06-09 at 09:32 +0200, ext Johannes Berg wrote:
> > > On Wed, 2010-06-09 at 09:50 +0300, Juuso Oikarinen wrote:
> > >
> > > > v3: - queue reconfig filter work to kernel default wq instead of mac80211 wq
> > >
> > > I think it would make more sense to use a different lock instead, like
> > > the iflist mutex?
> >
> > Yeah had that originally, but apparently the iflist mutex is acquired
> > *after* the mgd mutex in some places of the code, especially all around
> > mlme.c, and here I would have to acquire them in reverse order. So I
> > changed to the rtnl lock.
>
> Ah, right.
>
> However I'm a bit worried that making this workqueue change will allow
> the filter reconfigure to cross with suspend, which might mean it could
> execute after the device is suspended?
Ah yes. That's an obvious side-effect. I wonder if it would be solved by
flushing this particular work along with the mac80211 wq in the suspend
call, or would the implications then just move further?
Apart from the above, I'm out of ideas. If this is getting too complex,
I'll need to revert back to the patch that does not take into account
the promisc mode.
-Juuso