Messages in this thread Patch in this message | | | From | gregkh@linuxfou ... | Subject | [PATCH 5.11 273/306] sched/membarrier: fix missing local execution of ipi_sync_rq_state() | Date | Mon, 15 Mar 2021 14:55:36 +0100 |
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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
commit ce29ddc47b91f97e7f69a0fb7cbb5845f52a9825 upstream.
The function sync_runqueues_membarrier_state() should copy the membarrier state from the @mm received as parameter to each runqueue currently running tasks using that mm.
However, the use of smp_call_function_many() skips the current runqueue, which is unintended. Replace by a call to on_each_cpu_mask().
Fixes: 227a4aadc75b ("sched/membarrier: Fix p->mm->membarrier_state racy load") Reported-by: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org # 5.4.x+ Link: https://lore.kernel.org/r/74F1E842-4A84-47BF-B6C2-5407DFDD4A4A@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- kernel/sched/membarrier.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)
--- a/kernel/sched/membarrier.c +++ b/kernel/sched/membarrier.c @@ -471,9 +471,7 @@ static int sync_runqueues_membarrier_sta } rcu_read_unlock(); - preempt_disable(); - smp_call_function_many(tmpmask, ipi_sync_rq_state, mm, 1); - preempt_enable(); + on_each_cpu_mask(tmpmask, ipi_sync_rq_state, mm, true); free_cpumask_var(tmpmask); cpus_read_unlock();
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