mac80211: make scan_sdata pointer usable with RCU
Making the scan_sdata pointer usable with RCU makes
it possible to dereference it in the RX path to see
if a received frame actually matches the interface
that is scanning. This is just preparations, making
the pointer __rcu.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index b1edf60..e3c4974 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -112,10 +112,11 @@
}
}
- if (local->scan_sdata &&
- !(local->hw.flags & IEEE80211_HW_SCAN_WHILE_IDLE)) {
+ sdata = rcu_dereference_protected(local->scan_sdata,
+ lockdep_is_held(&local->mtx));
+ if (sdata && !(local->hw.flags & IEEE80211_HW_SCAN_WHILE_IDLE)) {
scanning = true;
- local->scan_sdata->vif.bss_conf.idle = false;
+ sdata->vif.bss_conf.idle = false;
}
list_for_each_entry(sdata, &local->interfaces, list) {
@@ -628,7 +629,7 @@
clear_bit(SDATA_STATE_RUNNING, &sdata->state);
- if (local->scan_sdata == sdata)
+ if (rcu_access_pointer(local->scan_sdata) == sdata)
ieee80211_scan_cancel(local);
/*