From: "Paul E. McKenney" <[email protected]> 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 use in dn_insert_route() is legitimate: It 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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Thomas Graf <[email protected]> Cc: Gao feng <[email protected]> Cc: Stephen Hemminger <[email protected]> Cc: [email protected] Cc: [email protected] --- net/decnet/dn_route.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c index fe32388ea24f..3b1357bcfc92 100644 --- a/net/decnet/dn_route.c +++ b/net/decnet/dn_route.c @@ -345,7 +345,7 @@ static int dn_insert_route(struct dn_route *rt, unsigned int hash, struct dn_rou /* Put it first */ *rthp = rth->dst.dn_next; rcu_assign_pointer(rth->dst.dn_next, - dn_rt_hash_table[hash].chain); + rcu_access_pointer(dn_rt_hash_table[hash].chain)); rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth); dst_use(&rth->dst, now); @@ -358,7 +358,8 @@ static int dn_insert_route(struct dn_route *rt, unsigned int hash, struct dn_rou rthp = &rth->dst.dn_next; } - rcu_assign_pointer(rt->dst.dn_next, dn_rt_hash_table[hash].chain); + rcu_assign_pointer(rt->dst.dn_next, + rcu_access_pointer(dn_rt_hash_table[hash].chain)); rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt); dst_use(&rt->dst, now); -- 1.8.1.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
