From 30be52e44fd4276d768efffb55d424fb682e6505 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Mon, 21 Nov 2011 11:23:50 +0100 Subject: [PATCH] mac80211: fix RCU warnings in mesh 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 Cc: Thomas Pedersen Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- net/mac80211/mesh_pathtbl.c | 27 +++++---------------------- 1 file changed, 5 insertions(+), 22 deletions(-) diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c index 4fc23d1b9c3..7bd2a76aef0 100644 --- a/net/mac80211/mesh_pathtbl.c +++ b/net/mac80211/mesh_pathtbl.c @@ -69,8 +69,6 @@ static inline struct mesh_table *resize_dereference_mpp_paths(void) 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(struct rcu_head *rp) } /** - * 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_table *tbl, struct mesh_path *mpath) 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); @@ -497,16 +490,6 @@ static int mesh_gate_del(struct mesh_table *tbl, struct mesh_path *mpath) return 0; } -/** - * - * 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 -- 2.20.1