Messages in this thread Patch in this message | | | From | Marc Zyngier <> | Subject | [PATCH v2 2/2] bus: arm-cci: Fix use of smp_processor_id() in preemptible context | Date | Tue, 3 Oct 2017 18:14:13 +0100 |
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The ARM CCI driver seem to be using smp_processor_id() in a preemptible context, which is likely to make a DEBUG_PREMPT kernel scream at boot time.
Turn this into a get_cpu()/put_cpu() that extends over the CPU hotplug registration, making sure that we don't race against a CPU down operation.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> --- drivers/bus/arm-cci.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c index c49da15d9790..d1aa11c083f9 100644 --- a/drivers/bus/arm-cci.c +++ b/drivers/bus/arm-cci.c @@ -1755,14 +1755,17 @@ static int cci_pmu_probe(struct platform_device *pdev) raw_spin_lock_init(&cci_pmu->hw_events.pmu_lock); mutex_init(&cci_pmu->reserve_mutex); atomic_set(&cci_pmu->active_events, 0); - cpumask_set_cpu(smp_processor_id(), &cci_pmu->cpus); + cpumask_set_cpu(get_cpu(), &cci_pmu->cpus); ret = cci_pmu_init(cci_pmu, pdev); - if (ret) + if (ret) { + put_cpu(); return ret; + } cpuhp_state_add_instance_nocalls(CPUHP_AP_PERF_ARM_CCI_ONLINE, &cci_pmu->node); + put_cpu(); pr_info("ARM %s PMU driver probed", cci_pmu->model->name); return 0; } -- 2.11.0
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