diff options
| author | Michal Kazior <michal.kazior@tieto.com> | 2014-03-05 13:14:08 +0100 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2014-04-09 10:55:49 +0200 |
| commit | 4e141dad266908735967b0961c8d90187825e0bc (patch) | |
| tree | 2fe457b25b558543257bb3c73d888e4f4bab8b5b /net/mac80211/iface.c | |
| parent | b6a550156bc08a472c9d2515631649e229fcfcef (diff) | |
| download | linux-4e141dad266908735967b0961c8d90187825e0bc.tar.bz2 | |
mac80211: protect AP VLAN list with local->mtx
It was impossible to change chanctx of master AP
for AP VLANs because the copy function requires
RTNL which can't be simply taken in mac80211 code
due to possible deadlocks.
This is required for future chanctx reservation
that re-bind vifs to new chanctx. This requires
safe AP VLAN iteration without RTNL.
Now VLANs can be iterated while holding either
RTNL or local->mtx because the list is modified
while holding both of these locks.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/mac80211/iface.c')
| -rw-r--r-- | net/mac80211/iface.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index ad5badd783d8..90b60633a27a 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -496,7 +496,9 @@ int ieee80211_do_open(struct wireless_dev *wdev, bool coming_up) if (!sdata->bss) return -ENOLINK; + mutex_lock(&local->mtx); list_add(&sdata->u.vlan.list, &sdata->bss->vlans); + mutex_unlock(&local->mtx); master = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap); @@ -726,8 +728,11 @@ int ieee80211_do_open(struct wireless_dev *wdev, bool coming_up) drv_stop(local); err_del_bss: sdata->bss = NULL; - if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) + if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) { + mutex_lock(&local->mtx); list_del(&sdata->u.vlan.list); + mutex_unlock(&local->mtx); + } /* might already be clear but that doesn't matter */ clear_bit(SDATA_STATE_RUNNING, &sdata->state); return res; @@ -879,7 +884,9 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, switch (sdata->vif.type) { case NL80211_IFTYPE_AP_VLAN: + mutex_lock(&local->mtx); list_del(&sdata->u.vlan.list); + mutex_unlock(&local->mtx); RCU_INIT_POINTER(sdata->vif.chanctx_conf, NULL); /* no need to tell driver */ break; |