* [Linux-kernel-mentees] [PATCH] ip6mr: Fix RCU list debugging warning
@ 2020-02-22 16:57 ` Amol Grover
0 siblings, 0 replies; 4+ messages in thread
From: Amol Grover @ 2020-02-22 16:57 UTC (permalink / raw)
To: David S . Miller, Alexey Kuznetsov, Hideaki YOSHIFUJI,
Jakub Kicinski
Cc: Paul E . McKenney, netdev, linux-kernel, Madhuparna Bhowmik,
Joel Fernandes, linux-kernel-mentees
ip6mr_for_each_table() macro uses list_for_each_entry_rcu()
for traversing outside an RCU read side critical section
but under the protection of rtnl_mutex. Hence add the
corresponding lockdep expression to silence the following
false-positive warnings:
[ 4.319479] =============================
[ 4.319480] WARNING: suspicious RCU usage
[ 4.319482] 5.5.4-stable #17 Tainted: G E
[ 4.319483] -----------------------------
[ 4.319485] net/ipv6/ip6mr.c:1243 RCU-list traversed in non-reader section!!
[ 4.456831] =============================
[ 4.456832] WARNING: suspicious RCU usage
[ 4.456834] 5.5.4-stable #17 Tainted: G E
[ 4.456835] -----------------------------
[ 4.456837] net/ipv6/ip6mr.c:1582 RCU-list traversed in non-reader section!!
Signed-off-by: Amol Grover <frextrite@gmail.com>
---
net/ipv6/ip6mr.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index bfa49ff70531..d6483926f449 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -97,7 +97,8 @@ static void ipmr_expire_process(struct timer_list *t);
#ifdef CONFIG_IPV6_MROUTE_MULTIPLE_TABLES
#define ip6mr_for_each_table(mrt, net) \
- list_for_each_entry_rcu(mrt, &net->ipv6.mr6_tables, list)
+ list_for_each_entry_rcu(mrt, &net->ipv6.mr6_tables, list, \
+ lockdep_rtnl_is_held())
static struct mr_table *ip6mr_mr_table_iter(struct net *net,
struct mr_table *mrt)
--
2.24.1
_______________________________________________
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Linux-kernel-mentees@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH] ip6mr: Fix RCU list debugging warning
@ 2020-02-22 16:57 ` Amol Grover
0 siblings, 0 replies; 4+ messages in thread
From: Amol Grover @ 2020-02-22 16:57 UTC (permalink / raw)
To: David S . Miller, Alexey Kuznetsov, Hideaki YOSHIFUJI,
Jakub Kicinski
Cc: linux-kernel, linux-kernel-mentees, Joel Fernandes,
Madhuparna Bhowmik, Paul E . McKenney, netdev, Amol Grover
ip6mr_for_each_table() macro uses list_for_each_entry_rcu()
for traversing outside an RCU read side critical section
but under the protection of rtnl_mutex. Hence add the
corresponding lockdep expression to silence the following
false-positive warnings:
[ 4.319479] =============================
[ 4.319480] WARNING: suspicious RCU usage
[ 4.319482] 5.5.4-stable #17 Tainted: G E
[ 4.319483] -----------------------------
[ 4.319485] net/ipv6/ip6mr.c:1243 RCU-list traversed in non-reader section!!
[ 4.456831] =============================
[ 4.456832] WARNING: suspicious RCU usage
[ 4.456834] 5.5.4-stable #17 Tainted: G E
[ 4.456835] -----------------------------
[ 4.456837] net/ipv6/ip6mr.c:1582 RCU-list traversed in non-reader section!!
Signed-off-by: Amol Grover <frextrite@gmail.com>
---
net/ipv6/ip6mr.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index bfa49ff70531..d6483926f449 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -97,7 +97,8 @@ static void ipmr_expire_process(struct timer_list *t);
#ifdef CONFIG_IPV6_MROUTE_MULTIPLE_TABLES
#define ip6mr_for_each_table(mrt, net) \
- list_for_each_entry_rcu(mrt, &net->ipv6.mr6_tables, list)
+ list_for_each_entry_rcu(mrt, &net->ipv6.mr6_tables, list, \
+ lockdep_rtnl_is_held())
static struct mr_table *ip6mr_mr_table_iter(struct net *net,
struct mr_table *mrt)
--
2.24.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [Linux-kernel-mentees] [PATCH] ip6mr: Fix RCU list debugging warning
2020-02-22 16:57 ` Amol Grover
@ 2020-02-24 21:19 ` David Miller
-1 siblings, 0 replies; 4+ messages in thread
From: David Miller @ 2020-02-24 21:19 UTC (permalink / raw)
To: frextrite
Cc: paulmck, yoshfuji, netdev, linux-kernel, madhuparnabhowmik10,
kuba, joel, kuznet, linux-kernel-mentees
From: Amol Grover <frextrite@gmail.com>
Date: Sat, 22 Feb 2020 22:27:27 +0530
> ip6mr_for_each_table() macro uses list_for_each_entry_rcu()
> for traversing outside an RCU read side critical section
> but under the protection of rtnl_mutex. Hence add the
> corresponding lockdep expression to silence the following
> false-positive warnings:
>
> [ 4.319479] =============================
> [ 4.319480] WARNING: suspicious RCU usage
> [ 4.319482] 5.5.4-stable #17 Tainted: G E
> [ 4.319483] -----------------------------
> [ 4.319485] net/ipv6/ip6mr.c:1243 RCU-list traversed in non-reader section!!
>
> [ 4.456831] =============================
> [ 4.456832] WARNING: suspicious RCU usage
> [ 4.456834] 5.5.4-stable #17 Tainted: G E
> [ 4.456835] -----------------------------
> [ 4.456837] net/ipv6/ip6mr.c:1582 RCU-list traversed in non-reader section!!
>
> Signed-off-by: Amol Grover <frextrite@gmail.com>
Applied, thanks.
_______________________________________________
Linux-kernel-mentees mailing list
Linux-kernel-mentees@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] ip6mr: Fix RCU list debugging warning
@ 2020-02-24 21:19 ` David Miller
0 siblings, 0 replies; 4+ messages in thread
From: David Miller @ 2020-02-24 21:19 UTC (permalink / raw)
To: frextrite
Cc: kuznet, yoshfuji, kuba, linux-kernel, linux-kernel-mentees, joel,
madhuparnabhowmik10, paulmck, netdev
From: Amol Grover <frextrite@gmail.com>
Date: Sat, 22 Feb 2020 22:27:27 +0530
> ip6mr_for_each_table() macro uses list_for_each_entry_rcu()
> for traversing outside an RCU read side critical section
> but under the protection of rtnl_mutex. Hence add the
> corresponding lockdep expression to silence the following
> false-positive warnings:
>
> [ 4.319479] =============================
> [ 4.319480] WARNING: suspicious RCU usage
> [ 4.319482] 5.5.4-stable #17 Tainted: G E
> [ 4.319483] -----------------------------
> [ 4.319485] net/ipv6/ip6mr.c:1243 RCU-list traversed in non-reader section!!
>
> [ 4.456831] =============================
> [ 4.456832] WARNING: suspicious RCU usage
> [ 4.456834] 5.5.4-stable #17 Tainted: G E
> [ 4.456835] -----------------------------
> [ 4.456837] net/ipv6/ip6mr.c:1582 RCU-list traversed in non-reader section!!
>
> Signed-off-by: Amol Grover <frextrite@gmail.com>
Applied, thanks.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-02-24 21:19 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2020-02-22 16:57 [Linux-kernel-mentees] [PATCH] ip6mr: Fix RCU list debugging warning Amol Grover
2020-02-22 16:57 ` Amol Grover
2020-02-24 21:19 ` [Linux-kernel-mentees] " David Miller
2020-02-24 21:19 ` David Miller
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