From: Johannes Berg <johannes.berg@xxxxxxxxx>
Sparse RCU checking reports two warnings in the mesh
path table code. These are due to questionable uses of
rcu_dereference.
To fix the first one, get rid of mesh_gate_add() and
just make mesh_path_add_gate() do the correct deref.
To fix the second one, simply remove rcu_dereference()
in mesh_gate_del() -- it already gets a proper pointer
as indicated by the prototype (no __rcu annotation)
and confirmed by the code.
Cc: Javier Cardona <javier@xxxxxxxxxxx>
Cc: Thomas Pedersen <thomas@xxxxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
---
v2: oops. fix prototypes
net/mac80211/mesh_pathtbl.c | 27 +++++----------------------
1 file changed, 5 insertions(+), 22 deletions(-)
--- a/net/mac80211/mesh_pathtbl.c 2011-11-21 11:19:44.000000000 +0100
+++ b/net/mac80211/mesh_pathtbl.c 2011-11-21 11:23:19.000000000 +0100
@@ -69,8 +69,6 @@ static inline struct mesh_table *resize_
lockdep_is_held(&pathtbl_resize_lock));
}
-static int mesh_gate_add(struct mesh_table *tbl, struct mesh_path *mpath);
-
/*
* CAREFUL -- "tbl" must not be an expression,
* in particular not an rcu_dereference(), since
@@ -420,21 +418,18 @@ static void mesh_gate_node_reclaim(struc
}
/**
- * mesh_gate_add - mark mpath as path to a mesh gate and add to known_gates
- * @mesh_tbl: table which contains known_gates list
- * @mpath: mpath to known mesh gate
- *
- * Returns: 0 on success
- *
+ * mesh_path_add_gate - add the given mpath to a mesh gate to our path table
+ * @mpath: gate path to add to table
*/
-static int mesh_gate_add(struct mesh_table *tbl, struct mesh_path *mpath)
+int mesh_path_add_gate(struct mesh_path *mpath)
{
+ struct mesh_table *tbl;
struct mpath_node *gate, *new_gate;
struct hlist_node *n;
int err;
rcu_read_lock();
- tbl = rcu_dereference(tbl);
+ tbl = rcu_dereference(mesh_paths);
hlist_for_each_entry_rcu(gate, n, tbl->known_gates, list)
if (gate->mpath == mpath) {
@@ -478,8 +473,6 @@ static int mesh_gate_del(struct mesh_tab
struct mpath_node *gate;
struct hlist_node *p, *q;
- tbl = rcu_dereference(tbl);
-
hlist_for_each_entry_safe(gate, p, q, tbl->known_gates, list)
if (gate->mpath == mpath) {
spin_lock_bh(&tbl->gates_lock);
@@ -498,16 +491,6 @@ static int mesh_gate_del(struct mesh_tab
}
/**
- *
- * mesh_path_add_gate - add the given mpath to a mesh gate to our path table
- * @mpath: gate path to add to table
- */
-int mesh_path_add_gate(struct mesh_path *mpath)
-{
- return mesh_gate_add(mesh_paths, mpath);
-}
-
-/**
* mesh_gate_num - number of gates known to this interface
* @sdata: subif data
*/
--
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