From: "Joel Fernandes (Google)" <joel@joelfernandes.org>
To: linux-kernel@vger.kernel.org, rcu@vger.kernel.org
Cc: Joel Fernandes <joel@joelfernandes.org>, paulmck@linux.ibm.com
Subject: [RFC 1/5] net: rtnetlink: Fix incorrect RCU API usage
Date: Tue, 19 Feb 2019 23:08:23 -0500 [thread overview]
Message-ID: <20190220040827.136184-2-joel@joelfernandes.org> (raw)
In-Reply-To: <20190220040827.136184-1-joel@joelfernandes.org>
From: Joel Fernandes <joel@joelfernandes.org>
rtnl_register_internal() and rtnl_unregister_all tries to directly
dereference an RCU protected pointed outside RCU read side section.
While this is Ok to do since a lock is held, let us use the correct
API to avoid programmer bugs in the future.
This also fixes sparse warnings arising from not using RCU API.
net/core/rtnetlink.c:332:13: warning: incorrect type in assignment
(different address spaces) net/core/rtnetlink.c:332:13: expected
struct rtnl_link **tab net/core/rtnetlink.c:332:13: got struct
rtnl_link *[noderef] <asn:4>*<noident>
Signed-off-by: Joel Fernandes <joel@joelfernandes.org>
---
net/core/rtnetlink.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 5ea1bed08ede..98be4b4818a9 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -188,7 +188,7 @@ static int rtnl_register_internal(struct module *owner,
msgindex = rtm_msgindex(msgtype);
rtnl_lock();
- tab = rtnl_msg_handlers[protocol];
+ tab = rtnl_dereference(rtnl_msg_handlers[protocol]);
if (tab == NULL) {
tab = kcalloc(RTM_NR_MSGTYPES, sizeof(void *), GFP_KERNEL);
if (!tab)
@@ -329,7 +329,7 @@ void rtnl_unregister_all(int protocol)
BUG_ON(protocol < 0 || protocol > RTNL_FAMILY_MAX);
rtnl_lock();
- tab = rtnl_msg_handlers[protocol];
+ tab = rtnl_dereference(rtnl_msg_handlers[protocol]);
if (!tab) {
rtnl_unlock();
return;
--
2.21.0.rc0.258.g878e2cd30e-goog
next prev parent reply other threads:[~2019-02-20 4:09 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-20 4:08 [RFC 0/5] RCU fixes for rcu_assign_pointer usage Joel Fernandes (Google)
2019-02-20 4:08 ` Joel Fernandes (Google) [this message]
2019-02-20 16:40 ` [RFC 1/5] net: rtnetlink: Fix incorrect RCU API usage Paul E. McKenney
2019-02-20 18:08 ` Joel Fernandes
2019-02-20 4:08 ` [RFC 2/5] ixgbe: " Joel Fernandes (Google)
2019-02-20 4:08 ` [RFC 3/5] sched/cpufreq: " Joel Fernandes (Google)
2019-02-20 4:08 ` [RFC 4/5] sched/toplogy: Use smp_store_release() instead of rcu_assign_pointer Joel Fernandes (Google)
2019-02-20 4:08 ` [RFC 5/5] rcuwait: Replace rcu_assign_pointer with smp_store_release Joel Fernandes (Google)
2019-02-20 4:11 ` [RFC 0/5] RCU fixes for rcu_assign_pointer usage Joel Fernandes
2019-02-20 16:42 ` Paul E. McKenney
2019-02-20 18:09 ` Joel Fernandes
2019-02-20 18:28 ` Paul E. McKenney
2019-02-21 16:50 ` Joel Fernandes
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