From: Dan Carpenter <dan.carpenter@oracle.com>
To: tuanphan@os.amperecomputing.com
Cc: linux-arm-kernel@lists.infradead.org
Subject: [bug report] driver/perf: Add PMU driver for the ARM DMC-620 memory controller
Date: Mon, 7 Dec 2020 20:56:48 +0300 [thread overview]
Message-ID: <X85s4Haz+LBzhKnF@mwanda> (raw)
Hello Tuan Phan,
The patch 53c218da220c: "driver/perf: Add PMU driver for the ARM
DMC-620 memory controller" from Nov 4, 2020, leads to the following
static checker warning:
drivers/perf/arm_dmc620_pmu.c:612 dmc620_pmu_cpu_teardown()
error: potential NULL dereference 'irq'.
drivers/perf/arm_dmc620_pmu.c
604 static int dmc620_pmu_cpu_teardown(unsigned int cpu,
605 struct hlist_node *node)
606 {
607 struct dmc620_pmu_irq *irq;
608 struct dmc620_pmu *dmc620_pmu;
609 unsigned int target;
610
611 irq = hlist_entry_safe(node, struct dmc620_pmu_irq, node);
612 if (cpu != irq->cpu)
There isn't any point to using hlist_entry_safe() instead of hlist_entry()
when we're not going to check for NULL returns.
613 return 0;
614
615 target = cpumask_any_but(cpu_online_mask, cpu);
616 if (target >= nr_cpu_ids)
617 return 0;
618
619 /* We're only reading, but this isn't the place to be involving RCU */
620 mutex_lock(&dmc620_pmu_irqs_lock);
621 list_for_each_entry(dmc620_pmu, &irq->pmus_node, pmus_node)
622 perf_pmu_migrate_context(&dmc620_pmu->pmu, irq->cpu, target);
623 mutex_unlock(&dmc620_pmu_irqs_lock);
regards,
dan carpenter
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next reply other threads:[~2020-12-07 17:58 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-07 17:56 Dan Carpenter [this message]
2020-12-09 20:57 ` [bug report] driver/perf: Add PMU driver for the ARM DMC-620 memory controller Tuan Phan
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