From: Thomas Gleixner <tglx@linutronix.de>
To: Mike Galbraith <efault@gmx.de>, RT <linux-rt-users@vger.kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: Re: [patch] Re: v5.15-rc2-rt3: WARNING: CPU: 0 PID: 12 at ./include/linux/seqlock.h:271
Date: Sun, 26 Sep 2021 17:10:45 +0200 [thread overview]
Message-ID: <87zgrzbcei.ffs@tglx> (raw)
In-Reply-To: <a105fecc71d4b721d4e025e2caf2b13336b5d0fc.camel@gmx.de>
On Sun, Sep 26 2021 at 06:05, Mike Galbraith wrote:
> On Fri, 2021-09-24 at 07:22 +0200, Mike Galbraith wrote:
> --- a/net/bridge/br_multicast.c
> +++ b/net/bridge/br_multicast.c
> @@ -1679,10 +1679,14 @@ static void br_multicast_update_querier(
> {
> lockdep_assert_held_once(&brmctx->br->multicast_lock);
>
> + if (IS_ENABLED(CONFIG_PREEMPT_RT))
> + preempt_disable();
That sequence count is protected by brmctx->br->multicast_lock, but
seqcount_init() does not associate the lock.
Untested below should cure it properly.
Thanks,
tglx
---
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -1677,8 +1677,6 @@ static void br_multicast_update_querier(
int ifindex,
struct br_ip *saddr)
{
- lockdep_assert_held_once(&brmctx->br->multicast_lock);
-
write_seqcount_begin(&querier->seq);
querier->port_ifidx = ifindex;
memcpy(&querier->addr, saddr, sizeof(*saddr));
@@ -3867,13 +3865,13 @@ void br_multicast_ctx_init(struct net_br
brmctx->ip4_other_query.delay_time = 0;
brmctx->ip4_querier.port_ifidx = 0;
- seqcount_init(&brmctx->ip4_querier.seq);
+ seqcount_spinlock_init(&brmctx->ip4_querier.seq, &br->multicast_lock);
brmctx->multicast_igmp_version = 2;
#if IS_ENABLED(CONFIG_IPV6)
brmctx->multicast_mld_version = 1;
brmctx->ip6_other_query.delay_time = 0;
brmctx->ip6_querier.port_ifidx = 0;
- seqcount_init(&brmctx->ip6_querier.seq);
+ seqcount_spinlock_init(&brmctx->ip6_querier.seq, &br->multicast_lock);
#endif
timer_setup(&brmctx->ip4_mc_router_timer,
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -82,7 +82,7 @@ struct bridge_mcast_other_query {
struct bridge_mcast_querier {
struct br_ip addr;
int port_ifidx;
- seqcount_t seq;
+ seqcount_spinlock_t seq;
};
/* IGMP/MLD statistics */
next prev parent reply other threads:[~2021-09-26 15:10 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-22 21:00 [ANNOUNCE] v5.15-rc2-rt3 Sebastian Andrzej Siewior
2021-09-24 5:22 ` v5.15-rc2-rt3: WARNING: CPU: 0 PID: 12 at ./include/linux/seqlock.h:271 Mike Galbraith
2021-09-26 4:05 ` [patch] " Mike Galbraith
2021-09-26 15:10 ` Thomas Gleixner [this message]
2021-09-27 3:19 ` Mike Galbraith
2021-09-27 8:13 ` [PATCH] net: bridge: mcast: Associate the seqcount with its protecting lock Sebastian Andrzej Siewior
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