From 0dbc81eab4d13f6d295da69c00e6efee2427b55c Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Sun, 8 Jul 2018 17:02:59 +0900 Subject: [PATCH] net: sched: Fix warnings from xchg() on RCU'd cookie pointer. The kbuild test robot reports: >> net/sched/act_api.c:71:15: sparse: incorrect type in initializer (different address spaces) @@ expected struct tc_cookie [noderef] *__ret @@ got [noderef] *__ret @@ net/sched/act_api.c:71:15: expected struct tc_cookie [noderef] *__ret net/sched/act_api.c:71:15: got struct tc_cookie *new_cookie >> net/sched/act_api.c:71:13: sparse: incorrect type in assignment (different address spaces) @@ expected struct tc_cookie *old @@ got struct tc_cookie [noderef] *[assigned] __ret >> net/sched/act_api.c:132:48: sparse: dereference of noderef expression Handle this in the usual way by force casting away the __rcu annotation when we are using xchg() on it. Fixes: eec94fdb0480 ("net: sched: use rcu for action cookie update") Reported-by: kbuild test robot Signed-off-by: David S. Miller --- net/sched/act_api.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sched/act_api.c b/net/sched/act_api.c index bf1c35f3deb6..66dc19746c63 100644 --- a/net/sched/act_api.c +++ b/net/sched/act_api.c @@ -68,7 +68,7 @@ static void tcf_set_action_cookie(struct tc_cookie __rcu **old_cookie, { struct tc_cookie *old; - old = xchg(old_cookie, new_cookie); + old = xchg((__force struct tc_cookie **)old_cookie, new_cookie); if (old) call_rcu(&old->rcu, tcf_free_cookie_rcu); } -- 2.30.2