Commit 0dbc81ea authored by David S. Miller's avatar David S. Miller

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] <asn:4>*__ret @@    got [noderef] <asn:4>*__ret @@
   net/sched/act_api.c:71:15:    expected struct tc_cookie [noderef] <asn:4>*__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] <struct tc_cookie *old @@
   net/sched/act_api.c:71:13:    expected struct tc_cookie *old
   net/sched/act_api.c:71:13:    got struct tc_cookie [noderef] <asn:4>*[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: eec94fdb ("net: sched: use rcu for action cookie update")
Reported-by: default avatarkbuild test robot <lkp@intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e9ec8045
...@@ -68,7 +68,7 @@ static void tcf_set_action_cookie(struct tc_cookie __rcu **old_cookie, ...@@ -68,7 +68,7 @@ static void tcf_set_action_cookie(struct tc_cookie __rcu **old_cookie,
{ {
struct tc_cookie *old; struct tc_cookie *old;
old = xchg(old_cookie, new_cookie); old = xchg((__force struct tc_cookie **)old_cookie, new_cookie);
if (old) if (old)
call_rcu(&old->rcu, tcf_free_cookie_rcu); call_rcu(&old->rcu, tcf_free_cookie_rcu);
} }
......
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