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 */
