Commit 30be52e4 authored by Johannes Berg's avatar Johannes Berg Committed by John W. Linville
Browse files

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 <javier@cozybit.com>
Cc: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 11a2a357
......@@ -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
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment