From: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>
The sparse checking for rcu_assign_pointer() was recently upgraded
to reject non-__kernel address spaces. This also rejects __rcu,
which is almost always the right thing to do. However, the uses in
sta_info_hash_del() are legitimate: They is assigning a pointer to an
element from an RCU-protected list, and all elements of this list are
already visible to caller.
This commit therefore silences this false positive by laundering the
pointer using rcu_access_pointer() as suggested by Josh Triplett.
Reported-by: kbuild test robot <fengguang.wu@xxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: "John W. Linville" <linville@xxxxxxxxxxxxx>
Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: linux-wireless@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
---
net/mac80211/sta_info.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index aeb967a..d18ab89 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -75,7 +75,7 @@ static int sta_info_hash_del(struct ieee80211_local *local,
return -ENOENT;
if (s == sta) {
rcu_assign_pointer(local->sta_hash[STA_HASH(sta->sta.addr)],
- s->hnext);
+ rcu_access_pointer(s->hnext));
return 0;
}
@@ -84,7 +84,7 @@ static int sta_info_hash_del(struct ieee80211_local *local,
s = rcu_dereference_protected(s->hnext,
lockdep_is_held(&local->sta_mtx));
if (rcu_access_pointer(s->hnext)) {
- rcu_assign_pointer(s->hnext, sta->hnext);
+ rcu_assign_pointer(s->hnext, rcu_access_pointer(sta->hnext));
return 0;
}
--
1.8.1.5
--
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