This is a note to let you know that I've just added the patch titled
rcu-tasks: Mark ->trc_reader_special.b.need_qs data races
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
rcu-tasks-mark-trc_reader_special.b.need_qs-data-races.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From stable-owner@xxxxxxxxxxxxxxx Sat Jul 15 02:47:26 2023
From: "Joel Fernandes (Google)" <joel@xxxxxxxxxxxxxxxxx>
Date: Sat, 15 Jul 2023 00:47:10 +0000
Subject: rcu-tasks: Mark ->trc_reader_special.b.need_qs data races
To: stable@xxxxxxxxxxxxxxx
Cc: "Joel Fernandes (Google)" <joel@xxxxxxxxxxxxxxxxx>, "Paul E . McKenney" <paulmck@xxxxxxxxxx>
Message-ID: <20230715004711.2938489-3-joel@xxxxxxxxxxxxxxxxx>
From: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
[ Upstream commit f8ab3fad80dddf3f2cecb53983063c4431058ca1 ]
There are several ->trc_reader_special.b.need_qs data races that are
too low-probability for KCSAN to notice, but which will happen sooner
or later. This commit therefore marks these accesses.
Cc: <stable@xxxxxxxxxxxxxxx> # 5.10.x
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/rcu/tasks.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -801,7 +801,7 @@ static DEFINE_IRQ_WORK(rcu_tasks_trace_i
/* If we are the last reader, wake up the grace-period kthread. */
void rcu_read_unlock_trace_special(struct task_struct *t, int nesting)
{
- int nq = t->trc_reader_special.b.need_qs;
+ int nq = READ_ONCE(t->trc_reader_special.b.need_qs);
if (IS_ENABLED(CONFIG_TASKS_TRACE_RCU_READ_MB) &&
t->trc_reader_special.b.need_mb)
@@ -867,7 +867,7 @@ static void trc_read_check_handler(void
// Get here if the task is in a read-side critical section. Set
// its state so that it will awaken the grace-period kthread upon
// exit from that critical section.
- WARN_ON_ONCE(t->trc_reader_special.b.need_qs);
+ WARN_ON_ONCE(READ_ONCE(t->trc_reader_special.b.need_qs));
WRITE_ONCE(t->trc_reader_special.b.need_qs, true);
reset_ipi:
@@ -919,7 +919,7 @@ static bool trc_inspect_reader(struct ta
// state so that it will awaken the grace-period kthread upon exit
// from that critical section.
atomic_inc(&trc_n_readers_need_end); // One more to wait on.
- WARN_ON_ONCE(t->trc_reader_special.b.need_qs);
+ WARN_ON_ONCE(READ_ONCE(t->trc_reader_special.b.need_qs));
WRITE_ONCE(t->trc_reader_special.b.need_qs, true);
return true;
}
@@ -1048,7 +1048,7 @@ static void show_stalled_task_trace(stru
".i"[is_idle_task(t)],
".N"[cpu > 0 && tick_nohz_full_cpu(cpu)],
READ_ONCE(t->trc_reader_nesting),
- " N"[!!t->trc_reader_special.b.need_qs],
+ " N"[!!READ_ONCE(t->trc_reader_special.b.need_qs)],
cpu);
sched_show_task(t);
}
Patches currently in stable-queue which might be from stable-owner@xxxxxxxxxxxxxxx are
queue-5.10/rcu-tasks-simplify-trc_read_check_handler-atomic-operations.patch
queue-5.10/netfilter-nf_tables-fix-chain-binding-transaction-logic.patch
queue-5.10/netfilter-nf_tables-drop-map-element-references-from-preparation-phase.patch
queue-5.10/netfilter-nf_tables-fix-scheduling-while-atomic-splat.patch
queue-5.10/netfilter-nf_tables-reject-unbound-anonymous-set-before-commit-phase.patch
queue-5.10/netfilter-nf_tables-use-net_generic-infra-for-transaction-data.patch
queue-5.10/netfilter-nftables-rename-set-element-data-activation-deactivation-functions.patch
queue-5.10/netfilter-nf_tables-incorrect-error-path-handling-with-nft_msg_newrule.patch
queue-5.10/rcu-tasks-mark-trc_reader_nesting-data-races.patch
queue-5.10/netfilter-nf_tables-reject-unbound-chain-set-before-commit-phase.patch
queue-5.10/rcu-tasks-mark-trc_reader_special.b.need_qs-data-races.patch
queue-5.10/netfilter-nf_tables-add-rescheduling-points-during-loop-detection-walks.patch
queue-5.10/netfilter-nf_tables-add-nft_trans_prepare_error-to-deal-with-bound-set-chain.patch
queue-5.10/netfilter-nf_tables-unbind-non-anonymous-set-if-rule-construction-fails.patch
