[PATCH net-next 2/4] net: sched: refactor police action helpers to require tcf_lock
From: Vlad Buslov <hidden>
Date: 2020-02-11 09:19:49
Subsystem:
networking [general], tc subsystem, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Jamal Hadi Salim, Jiri Pirko, Linus Torvalds
In order to remove rtnl lock dependency from flow_action representation translator, change rcu_dereference_bh_rtnl() to rcu_dereference_protected() in police action helpers that provide external access to rate and burst values. This is safe to do because the functions are not called from anywhere else outside flow_action infrastructure which was modified to obtain tcf_lock when accessing action data in one of previous patches in the series. Signed-off-by: Vlad Buslov <redacted> Acked-by: Jiri Pirko <redacted> --- include/net/tc_act/tc_police.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/include/net/tc_act/tc_police.h b/include/net/tc_act/tc_police.h
index cfdc7cb82cad..f098ad4424be 100644
--- a/include/net/tc_act/tc_police.h
+++ b/include/net/tc_act/tc_police.h@@ -54,7 +54,8 @@ static inline u64 tcf_police_rate_bytes_ps(const struct tc_action *act) struct tcf_police *police = to_police(act); struct tcf_police_params *params; - params = rcu_dereference_bh_rtnl(police->params); + params = rcu_dereference_protected(police->params, + lockdep_is_held(&police->tcf_lock)); return params->rate.rate_bytes_ps; }
@@ -63,7 +64,8 @@ static inline s64 tcf_police_tcfp_burst(const struct tc_action *act) struct tcf_police *police = to_police(act); struct tcf_police_params *params; - params = rcu_dereference_bh_rtnl(police->params); + params = rcu_dereference_protected(police->params, + lockdep_is_held(&police->tcf_lock)); return params->tcfp_burst; }
--
2.21.0